U.S. patent application number 15/469513 was filed with the patent office on 2017-09-07 for systems and methods for reducing audio distortion during playback of phonograph records using multiple tonearm geometries.
The applicant listed for this patent is W. Leo Hoarty. Invention is credited to W. Leo Hoarty.
Application Number | 20170256281 15/469513 |
Document ID | / |
Family ID | 55853377 |
Filed Date | 2017-09-07 |
United States Patent
Application |
20170256281 |
Kind Code |
A1 |
Hoarty; W. Leo |
September 7, 2017 |
SYSTEMS AND METHODS FOR REDUCING AUDIO DISTORTION DURING PLAYBACK
OF PHONOGRAPH RECORDS USING MULTIPLE TONEARM GEOMETRIES
Abstract
Systems and methods are disclosed relating to electro-mechanical
devices and related computer control and audio processing systems
intended to optimize playback fidelity of phonograph records. Said
recordings are manufactured by a process that employs a cutting
head assembly driven in a straight path from the outer to the
inner-most radius of the recordable surface. However, most record
turntables device that are used to play back phonograph records
rely on a stylus transducer attached to the end of a pivoting arm.
Instead of the linear path followed by the original cutting head,
said tonearm traces an arc across the surface of the recorded disk
resulting in playback distortion proportional to error in alignment
of said stylus relative to the tangent of the groove. This
invention addresses this deficiency and produces an optimal audio
quality of playback of phonograph records.
Inventors: |
Hoarty; W. Leo; (Morgan
Hill, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hoarty; W. Leo |
Morgan Hill |
CA |
US |
|
|
Family ID: |
55853377 |
Appl. No.: |
15/469513 |
Filed: |
March 25, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14929682 |
Nov 2, 2015 |
9607650 |
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15469513 |
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62074076 |
Nov 2, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11B 20/02 20130101;
G11B 3/34 20130101; H04H 60/04 20130101; G11B 27/034 20130101; G11B
27/028 20130101; G11B 27/026 20130101; G11B 19/00 20130101; G11B
3/38 20130101; G11B 11/20 20130101 |
International
Class: |
G11B 11/20 20060101
G11B011/20; G11B 20/02 20060101 G11B020/02 |
Claims
1. A system, comprising: circuitry configured for obtaining a first
audio segment associated with a first recording area of a
phonograph record; circuitry configured for obtaining at least a
second audio segment associated with at least a second recording
area of the phonograph record, the second recording area at least
partially overlapping with the first recording area; circuitry
configured for aligning at least an end portion of the first audio
segment with a start portion of the at least a second audio
segment; and circuitry configured for outputting a continuous audio
stream associated with the first audio segment and the at least a
second audio segment.
2. The system of claim 1, further comprising: a turntable
configured for rotatably supporting the phonograph record; a first
tonearm calibrated with one or more distortion reduction values
associated with the first recording area; at least a second tonearm
calibrated with one or more distortion reduction values associated
with the at least a second recording area; and at least one
non-transitory computer-readable medium configured at least for
storage of the first audio segment and the at least a second audio
segment.
3. The system of claim 1, further comprising: at least one image
sensor disposed for obtaining at least one image of the first
tonearm and the at least a second tonearm; image recognition logic
configured at least to provide positional data related to the first
and the at least a second tonearm at least partially via
recognizing views of the first tonearm and the at least a second
tonearm at least partially using the at least one image sensor; and
a tonearm positioning arrangement configured to position the first
and the at least a second tonearm in association with obtaining the
first audio segment and the at least a second audio segment at
least partially based on provided positional data.
4. The system of claim 1, wherein circuitry configured for
obtaining a first audio segment associated with a first recording
area of a phonograph record comprises: circuitry configured for
receiving an indication of at least an outer groove radius and an
inner groove radius associated with the first recording area; and
circuitry configured for obtaining the first audio segment at least
partially via traversing a radial distance between the outer groove
radius and the inner groove radius associated with the first
recording area.
5. The system of claim 4, wherein circuitry configured for
receiving an indication of at least an outer groove radius and an
inner groove radius associated with the first recording area
comprises: circuitry configured for receiving a distance between a
spindle center and an outer boundary of the first recording area as
the outer groove radius; and circuitry configured for receiving a
distance between the spindle center and an inner boundary of the
first recording area as the inner groove radius.
6. The system of claim 4, wherein circuitry configured for
obtaining the first audio segment at least partially via traversing
a radial distance between the outer groove radius and the inner
groove radius associated with the first recording area comprises:
circuitry configured for controlling a first tonearm to receive
audio data recorded between the outer groove radius and the inner
groove radius associated with the first recording area, the first
tonearm associated with one or more first recording area
calibrations related to distortion reduction.
7. The system of claim 1, wherein circuitry configured for
obtaining at least a second audio segment associated with at least
a second recording area of the phonograph record, the second
recording area at least partially overlapping with the first
recording area comprises: circuitry configured for receiving an
indication of at least an outer groove radius and an inner groove
radius associated with the second recording area, the outer groove
radius associated with the second recording area outside of an
inner groove radius associated with the first recording area; and
circuitry configured for obtaining the second audio segment at
least partially via traversing a radial distance between the outer
groove radius and the inner groove radius associated with the
second recording area.
8. The system of claim 1, wherein circuitry configured for
obtaining a first audio segment associated with a first recording
area of a phonograph record and circuitry configured for obtaining
at least a second audio segment associated with at least a second
recording area of the phonograph record, the second recording area
at least partially overlapping with the first recording area
comprise: circuitry configured for obtaining the first audio
segment at least partially via a first tonearm associated with one
or more first calibrations related to distortion reduction within
the first recording area and circuitry configured for obtaining the
second audio segment at least partially via a second tonearm
associated with one or more second calibrations related to
distortion reduction within the second recording area.
9. The system of claim 8, wherein circuitry configured for
obtaining the first audio segment at least partially via a first
tonearm associated with one or more first calibrations related to
distortion reduction within the first recording area and circuitry
configured for obtaining the second audio segment at least
partially via a second tonearm associated with one or more second
calibrations related to distortion reduction within the second
recording area comprises: circuitry configured for controlling a
start location of the first tonearm; circuitry configured for
controlling a start location of the second tonearm; and circuitry
configured for obtaining at least a portion of the first audio
segment associated with the first tonearm concurrent with obtaining
at least a portion of the second audio segment associated with the
second tonearm.
10. The system of claim 8, wherein circuitry configured for
obtaining the first audio segment at least partially via a first
tonearm associated with one or more first calibrations related to
distortion reduction within the first recording area and circuitry
configured for obtaining the second audio segment at least
partially via a second tonearm associated with one or more second
calibrations related to distortion reduction within the second
recording area comprises: circuitry configured for controlling a
start location of the first tonearm; circuitry configured for
controlling a start location of the second tonearm; circuitry
configured for obtaining the first audio segment associated with
the first tonearm; and circuitry configured for obtaining the
second audio segment associated with the second tonearm subsequent
to obtaining the first audio segment associated with the first
tonearm.
11. The system of claim 1, wherein circuitry configured for
obtaining a first audio segment associated with a first recording
area of a phonograph record comprises: circuitry configured for
positioning a first tonearm in association with an outer groove
radius of the first recording area at least partially using at
least one image sensor; circuitry configured for controlling the
first tonearm to receive audio data; circuitry configured for
determining a relation between the first tonearm and the inner
groove radius of the first recording area at least partially using
the at least one image sensor; and circuitry configured for
re-positioning the first tonearm responsive to the determined
relation.
12. The system of claim 11, further comprising: circuitry
configured for tagging the received audio data in association with
an indication of the first tonearm passing a radius associated with
the at least a second recording area.
13.-14. (canceled)
15. The system of claim 1, wherein circuitry configured for
outputting a continuous audio stream associated with the first
audio segment and the at least a second audio segment comprises:
circuitry configured for determining a splice point; and circuitry
configured for outputting a continuous audio stream associated with
the obtained first and second audio segments at least partially
based on the determined splice point.
16. The system of claim 15, wherein circuitry configured for
determining a splice point comprises: circuitry configured for
determining a splice point between the aligned at least an end
portion of the first audio segment and at least a start portion of
the second audio segment.
17. The system of claim 16, wherein circuitry configured for
determining a splice point aligned at least an end portion of the
first audio segment and at least a start portion of the second
audio segment comprises: circuitry configured for determining a
splice point between the aligned at least an end portion of the
first audio segment and at least a start portion of the second
audio segment at least partially based on optically-detected
data.
18. The system of claim 15, wherein circuitry configured for
outputting a continuous audio stream associated with the obtained
first and second audio segments at least partially based on the
determined splice point comprises: circuitry configured for
preparing the continuous audio stream at least partially based on
concatenating a portion of the first audio segment ending at the
determined splice point and a portion of the second audio segment
beginning at the determined splice point; and circuitry configured
for outputting the prepared continuous audio stream.
19. A system, comprising: means for obtaining a first audio segment
associated with a first recording area of a phonograph record;
means for obtaining at least a second audio segment associated with
at least a second recording area of the phonograph record, the
second recording area at least partially overlapping with the first
recording area; means for aligning at least an end portion of the
first audio segment with a start portion of the at least a second
audio segment; and means for outputting a continuous audio stream
associated with the first audio segment and the at least a second
audio segment.
20. A method, comprising: obtaining a first audio segment
associated with a first recording area of a phonograph record;
obtaining at least a second audio segment associated with at least
a second recording area of the phonograph record, the second
recording area at least partially overlapping with the first
recording area; aligning at least an end portion of the first audio
segment with a start portion of the at least a second audio segment
at least partially via digital signal processing of digital storage
associated with the first and the at least a second audio segment;
and outputting a continuous audio stream associated with the first
audio segment and the at least a second audio segment at least
partially via digital signal processing of digital storage
associated with the first and the at least a second audio
segment.
21. The system of claim 17, wherein circuitry configured for
determining a splice point between the aligned at least an end
portion of the first audio segment and at least a start portion of
the second audio segment at least partially based on
optically-detected data comprises: circuitry configured for
determining a splice point between the aligned at least an end
portion of the first audio segment and at least a start portion of
the second audio segment at least partially based on
optically-detected data, the optically-detected data detected while
obtaining one or more of at least a portion of the first audio
segment or at least a portion of the at least a second audio
segment.
22. The system of claim 16, wherein circuitry configured for
determining a splice point aligned at least an end portion of the
first audio segment and at least a start portion of the second
audio segment comprises: circuitry configured for determining a
splice point between the aligned at least an end portion of the
first audio segment and at least a start portion of the second
audio segment at least partially based on at least one tag
associated with an indication of a first tonearm passing a radius
associated with the at least a second recording area.
Description
PRIORITY CLAIM
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 62/074,076, entitled "SYSTEMS AND METHODS
FOR REDUCING AUDIO DISTORTION DURING PLAYBACK OF PHONOGRAPH RECORDS
USING MULTIPLE TONEARM GEOMETRIES," filed Nov. 2, 2014, naming W.
Leo Hoarty as the inventor. The foregoing application(s) are either
currently co-pending or are applications of which the instant or a
currently co-pending application is entitled to the benefit of the
filing date.
FIELD OF THE INVENTION
[0002] This invention relates generally to the conversion of analog
music stored on phonograph records to high-resolution digital
files. More specifically, the invention involves a method of
employing a plurality of tonearms and phonograph cartridges in
association with a single phonograph playback device; with each
such tonearm and cartridge pair optimally aligned for some specific
subset of the recorded area of the phonograph record in a manner
that minimizes the tracking error-induced audio distortion within
said area. The system of the invention further utilizes an
analog-to-digital converter to digitize the output of each
phonograph cartridge. An optical sensor means is used to detect
each tonearm's position during playback and to register to a memory
means the time location of the respective record file of each
phonograph cartridge with the intended crossover point where one
cartridge recording ends and the next cartridge recording is to
begin. A digital stitching means then combines the individual
digital audio files into a single digital audio file for real time
playback or storage of said file.
BACKGROUND
[0003] The music recording industry went through a transition to
digital audio recording methods in the 1980s. Most major recording
studios adopted early-generation digital recording equipment
replacing the then thirty-year-old analog tape recording equipment.
The product of the technology shift was the now ubiquitous compact
disc recording or CD which rapidly replaced the long-playing analog
disk now as the vinyl LP.
[0004] The initial generation of digital audio processing equipment
is now recognized as deficient in audio accuracy in many ways and
the quality of audio recordings suffered as a result. Hence, many
audiophiles rejected the sound quality of CDs and remained users of
the vinyl LP and its associated playback means. In the last decade,
the sales of vinyl LPs has seen a strong growth with sales
increasing more than 50% year-over-year.
[0005] The typically mature audiophile continues to be a major
purchaser of both new and used LPs and, in the last decade or so,
has been joined by a much younger generation who are discovering
the refined audio quality of the vinyl LP recording. Undoubtedly,
the fascination of the old-fashioned technology and associated
equipment attracts many new users but the audio industry continues
to innovate and produced better quality playback equipment at all
price points of the consumer electronics industry.
[0006] The old-generation, master recording analog magnetic tapes
are aging, missing or were destroyed in several notable fires in
storage facilities. The analog magnetic tape masters still on the
shelves of the record companies after many decades are aging and
demagnetizing. Further loss of reference recordings occurred
because many popular artist's analog tape recordings from the
period of the late 1950's to the mid-1980's, when the digital
recording transition began, were transferred to digital tape and
the original analog recordings were actually discarded.
[0007] The last many decades have left the archive libraries of
master tapes of great music with poor quality audio recordings of
some very important musicians and performances. This gap spans the
period of around 1985 to as recently as 2010. When a music label or
service wishes to re-release a recording from the past, if the
master tape is missing, the company will use a phonograph recording
and record it digitally. This industry technique is known to the
skilled person as a "needle drop."
[0008] In order to obtain a usable recording from a phonograph
record one needs to apply many engineering best practices including
the use of high-end turntables and high-quality audio electronics.
Most phonograph players use single tonearms that trace an arc
across the surface of the record as the needle follows the groove.
Unfortunately, the record master disk was cut on a lathe with a
cutting head driven on a worm screw straight across the surface of
the disk. This mismatch of geometries of a straight line versus an
arc results in measurable playback distortion.
[0009] Various attempts to minimize said tracking distortion of
phonograph players have been proposed. The most obvious solution is
to use a so-called linear tonearm where instead of pivoting in an
arc at the end of a fixed shaft, the cartridge is transported along
a direct radial path following the straight track of the original
cutting head. However, the record master cutting head was pushed
across the master record on a turning worm screw shaft while
cutting the master whereas said linear playback solutions introduce
new sources of distortion and noise due to side-loading forces on
the stylus and cantilever resulting from the force exerted to pull
the entire playback mechanism along the record from outer to inner
groove.
[0010] This invention addresses the need for much more accurate
playback of phonograph records which is of particular interest to
recording studios that need to recover previous made recordings
with quality close to the original master tapes that made the
phonograph recording.
SUMMARY OF THE INVENTION
[0011] The solution to minimizing the pivoting tonearm tracking
distortion on playback is to create a tonearm that enables the
playback stylus to precisely replicate the linear path of the
cutting head. Called a "linear tonearm," such solutions have been
proposed for decades, but have proven to be exceedingly expensive
to implement while at the same time introducing their own sources
of distortion and noise in terms of side-loading forces on the
stylus in the groove and noise from the shuttle mechanism utilized
to carry the arm and cartridge, among other problems.
[0012] The object of this invention then is to utilize a plurality
of traditional pivoting tonearms, typically using identical
phonograph cartridges, but modified according to the method of the
invention whereby each said tonearm is aligned and calibrated to
play back audio from a predetermined subset of the total radial
distance of the subject phonograph record and to do so with the
least amount of distortion. In one example of the invention, with a
two-arm playback system of the invention, one arm would record from
the lead-in groove point at a distance of 146 mm from the spindle
to, in this example, 90 mm from the spindle. The second arm would
record from 100 mm from the spindle to the end point lead-out
groove at approximately 60 mm from the spindle. The two or more
tonearms of the invention can be positioned and recorded
simultaneously or sequentially. If sequentially, each said arm will
be digitally recorded through a common analog-to-digital (ADC)
converter with an analog switching means directing the respective
tonearm signal to the ADC. Said tonearms are mechanically
positioned and removed from the recording surface by a
computer-controlled positioning system of the invention. Another
system of the invention finds the precise splice point in the
multiplicity of overlapping digitally-recorded audio streams to
stitch said recordings into a single, uninterrupted digital audio
representation of the record album.
[0013] While turntables with multiple tonearms are well known to
those skilled in the art, their purpose has generally been to mount
phonograph cartridges optimized for, among other things, different
types of recording standards such as stereo or monaural disks, or
for play back of older 78 rpm recordings which pre-dated the
long-playing era that began in the 1950's and which require special
cartridges. In addition, some audiophiles, as serious hobbyists,
have a turntable with a plurality of tonearms equipped with various
cartridges simply to compare and enjoy the different tonal
qualities of a variety of brands or styles of tonearms and/or
cartridges.
[0014] A digital image-processing program is configured to detect
each arm as it crosses into and out of its respective recording
region. The time position of these respective event points is
recorded and used by a digital audio splicing means of the
invention to locate the approximate audio overlap points. Then, by
means of autocorrelation, the system of the invention finds the
exact splice point between respective pairs of audio recordings and
joins the two files into one contiguous digital recording with no
discernable audible artifact. Any number of tonearms can be applied
to this method with subsequently smaller playback areas and even
lower distortion being recorded per arm. Based on the testing done
in the development of the present Invention, little perceptually
detectable improvement is gained beyond employing four tonearms,
and practically speaking, a system with two tonearms is often
sufficient.
[0015] The optical means of detecting tonearm position on the
surface of the recorded medium and automatically marking its
position in the audio file recorded from said tonearm is a
convenience. Using audio matching algorithms such as
autocorrelation is sufficient to align the separate audio tracks
for the purposes of splicing said tracks into a single audio file.
The splice points between the now aligned audio tracks is
determined without the advantage of the optical monitoring means by
measuring total time of the recorded audio and dividing said time
by the proportion of the disk that each arm is calibrated to
record. The presence of position markers merely simplifies this
task.
[0016] Since each tonearm and cartridge combination associated with
the subject playback turntable has been independently mechanically
adjusted and calibrated to minimize tracking error and the
resulting distortion for a specific subset of the total outer to
inner arc, the average tracking distortion for the assembled
sections is diminished to a small fraction of what would normally
be encountered with even the best single-arm approach. In fact, the
resulting audio recovered from the recorded groove has total
harmonic distortion characteristics quite close to a linear
tracking tonearm but with none of the distortion caused by a linear
playback arm nor any of the noise of the bearings of the shuttle
assembly supporting the linear arm.
[0017] Other scholarly studies have been published, for example H.
G. Baerwald's "Analytic Treatment of Tracking Error and Notes on
Optimal Pick-Up Design" Published May 1, 1941, and B. B. Bauer
"Tracking Angle" published in Electronics in March 1945, are
examples and are also incorporated by reference herein, providing
additional detail on this matter and offering slightly different
approaches to optimizing the alignment of cartridges and
tonearms.
[0018] What is disclosed in some embodiments is a system for
reducing audio distortion in the playback of an analog phonograph
record by employing a plurality of radially-mounted tonearms each
traversing a subset of the total radial distance across the surface
of an audio recording. The subset of the surface recorded by said
tonearm approached the ideal tracking accuracy of a linear
tonearm.
[0019] Disclosed in other embodiments is a system where the audio
is digitized from each of a plurality of tonearms and stored as
respective digital files which are then joined to form a single
representation of the audio recording. Disclosed in other
embodiments is a system where an optical detector is used to
ascertain the position of each participating tonearm and upon
detecting a predetermined position, to record the time position of
said tonearm. Disclosed in other embodiments is a system where a
plurality of tonearms simultaneously record respective subsets of a
phonograph record surface thereby reducing the time to record said
phonograph record to total time of phonograph information divided
by the number of tonearms employed.
[0020] Disclosed in other embodiments is a system where by a single
computer-controlled, motor-adjustable tonearm means may be employed
to playback individual bands of an audio recording where the offset
angle of the tonearm head assembly is automatically set and fix for
a portion of said recording. The controller means adjusts the
offset angle for each subset of the recording surface. Disclosed in
other embodiments is a system where a video camera is position
above a rotating turntable such that said camera can provide a
continuous image to a control means which calculated the rotational
speed of the turntable platter and provides information to a motor
speed controller to maintain precise adjustment of said speed.
[0021] In one or more various aspects, related systems include but
are not limited to circuitry and/or programming for effecting the
herein-referenced method aspects; the circuitry and/or programming
can be virtually any combination of hardware, software, and/or
firmware configured to effect the herein-referenced method aspects
depending upon the design choices of the system designer.
[0022] In addition to the foregoing, various other methods, systems
and/or program product embodiments are set forth and described in
the teachings such as the text (e.g., claims, drawings and/or the
detailed description) and/or drawings of the present
disclosure.
[0023] The foregoing is a summary and thus contains, by necessity,
simplifications, generalizations and omissions of detail;
consequently, those skilled in the art will appreciate that the
summary is illustrative only and is NOT intended to be in any way
limiting. Other aspects, embodiments, features and advantages of
the device and/or processes and/or other subject matter described
herein will become apparent in the teachings set forth herein.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 is a drawing of an exemplary two-tonearm embodiment
of the invention with the major mechanical components identified.
The outer tonearm 101 follows track 108 traversing an arc across
the outer one-half of the recorded surface of an audio record with
some overlap of the second half. The inner arm 102 traverses the
inner one-half of the recorded surface with some overlap of the
first half.
[0025] FIG. 1b is a simplified drawing illustrating the primary
components of a linear-tonearm turntable, with shuttle track 111
transporting the shuttle 114 in a linear path across a phonograph
disk placed on platter 113. This mechanism is supported by two
piers 115a and 115b. The shuttle supports an arm wand 112 that in
turn supports a head assembly with cartridge and associated stylus
116 aligned such that the stylus is transported in a direct radial
path 117 across the surface of said recording, following the path
taken by the original cutting head during the record mastering
process.
[0026] FIG. 2 illustrates the surface areas of a phonograph
recording 201, as is addressed by an exemplary two-tonearm
embodiment of the Invention. The traditional recorded area between
the lead-in groove 202 and lead-out groove 205 is now treated as
two areas of the outer area 203 and an inner area 204. Three or
more tonearms could be employed with proportionately less surface
area traversed by each said arm. In one embodiment, all arms are
simultaneously placed at the start of their respective areas. In
this figure, outer arm 213 is placed at the start of area 203 on
the lead-in groove and inner arm 214 is placed just before the
start of area 204 overlapping the end of area 203. Each arm is
digitally recorded to a separate audio track which traversing each
respective surface area. At the end of the recording area, each arm
is mechanically lifted and returned to said arm's respective rest
position by means of the invention later described.
[0027] FIG. 3 is a drawing similar to FIG. 1, but modified to
illustrate a three-arm embodiment of the invention with the three
tonearms 301, 302 and 303 each pivoting independently and
simultaneously following the groove track along outer arc 321,
middle arc 322, and inner arc 323 respectively thus covering the
recorded area between the lead-in to lead-out groove of a typical
audio recording such as the vinyl LP.
[0028] FIG. 4 is similar to FIG. 2 but modified to illustrate the
areas of a vinyl LP record or similar recording as would be
addressed by an exemplary three-tonearm embodiment of the Invention
as illustrated in the preceding FIG. 3. The outer tonearm 301 in
FIG. 3 enters the outer recording area at lead-in groove 402 and
passes through to 403 recording area. Simultaneously, the middle
tonearm 302 in FIG. 3, is lowered by the positioning means of the
invention to enter 404 and tonearm 303 of FIG. 3 is lowered a few
seconds outside of area 405 to play said area. Groove spacing is
not uniform on phonograph recordings and, hence, each arm may reach
the end of its sector at a slightly different time. The arm control
means of the invention is programmed to lift and park each arm as
each said sector is traversed by said respective tonearm.
[0029] FIG. 5 is a drawing illustrating the terms of art used in
describing the geometry of a pivoting tonearm and phonograph
record. The tonearm pivots at point 501 and the distance from said
point to the tip of the phonograph stylus 512 is the effective
length 504 of the tonearm. Said length 504 and offset angle 507
determines the arc 511 traced by the stylus 512 as it traverses the
recording. Overhang 508 is the distance from the spindle 502 to the
arc of stylus 512 which is the distance that said stylus exceeds
the distance to said spindle. The offset angle 507 is the angle
that the cartridge sits relative to the tonearm. Distance 503,
length 504 and angle 507 determine the arc that the stylus 512
traverses from the lead-in groove to the lead-out or inner-most
groove. The application of overhang 508 and offset angle 507 cause
the arc traced by stylus 512 to be exactly perpendicular to the
groove wall at two points in the path. At the outer null point 509
and inner null point 510 the stylus is perpendicular to the groove
and tracking distortion is minimal.
[0030] FIG. 6 are the formulas developed by Lofgren and Baerwald in
the first half of the 20.sup.th century to calculate the parameters
described above to set the arm and cartridge position to minimize
tracking distortion. Optimum Angular Offset 601 computers the angle
.alpha. which is used to calculate the Linear offset 601 which
determines Effective Length 603 which further determines Overhang
604 with the aid of Inner Null Radius 605 and Outer Null Radius
606.
[0031] FIG. 7 is a graphic representation of the tracking error 708
and harmonic distortion 702 associated with a "Baerwald" single
tonearm configuration and alignment as defined by parameters 709,
710 and 711 computed with the aid of the formulas of FIG. 6. As
previously noted, the originator of this alignment scheme, Erik
Lofgren, published a paper in 1938 that defined the relationship of
the tonearm cartridge to the surface of a recorded disk for the
purpose of minimizing audio distortion in the playback of audio due
to tracking error 708. The Lofgren A alignment causes the peak
distortion 703 of the lead-in groove position to be equal to the
peak distortion 702 of the area between the two null points 705 and
706 and the final lead-out groove 701 of the recorded
information.
[0032] FIG. 8 is a graphic representation of the tracking error and
distortion associated with another single tonearm configuration
known as "Lofgren" showing the substantial change in tacking
distortion 802 associated with a small change in only one of the
three parameters, specifically the "Overhang" as shown in 508 of
FIG. 5. In Lofgren, the average (RMS) distortion is equal from the
lead-in 804, to the first null point 805, the middle section 802,
and the lead-out, 801.
[0033] FIG. 9 is a graphic of the tracking error and distortion
associated with one of the preferred alignments and configurations
of the outer tonearm of an example dual arm embodiment. Note that
since tracking error and distortion for the inner area of the
recorded surface between approximately 901 and 907 are no longer
relevant to the user experience, the three parameters of Effective
Length 909, Angular Offset 910, and Overhang 911 may be adjusted to
minimize the average tracking error and distortion for a shorter
path resulting in the tracking distortion for the area between 901
and 903 to be much lower than a single arm tracing the entire
surface of 901 to 907.
[0034] FIG. 10 is a template used to calibrate the outer tonearm of
an exemplary two-arm embodiment. A hole is punched at 1001 for the
turntable spindle. The template is cut-out along circumference 1002
and a placed over the spindle and aligned with tonearm pivot 1003.
The stylus is placed in the 1006 grid and the cartridge shell is
rotated to be parallel to the grid lines. The cartridge head is
moved out or in such that the stylus touches point 1007. The
tonearm is then swung to grid 1004 and the process checked for the
stylus touching point 1005 and the cartridge shell remaining
parallel to the grid lines. Upon achieving alignment, the cartridge
is tightened to lock the calibration and the tonearm is ready to be
used for the outer sector playback of a phonograph record with
minimum tracking error and concomitant distortion.
[0035] FIG. 11 is a graphic of the tracking error and distortion
associated with one of the preferred alignments and configurations
of the inner tonearm of an example dual arm embodiment. Note that
since tracking error and distortion for the outer area of the
recorded surface before point 1101 are no longer relevant to the
user experience, the three parameters of Effective Length 1109,
Angular Offset 1110, and Overhang 1111 may be adjusted to minimize
the average tracking error and distortion for a shorter path
resulting in the tracking distortion for the area between 1101 and
1103 to be much lower than a single arm tracing the entire surface
of 1101 to 1107.
[0036] FIG. 12 is a template used to calibrate the inner tonearm of
an exemplary two-arm embodiment. A hole is punched at 1201 for the
turntable spindle. The template is cut-out along circumference 1202
and a placed over the spindle and aligned with tonearm pivot 1203.
The stylus is placed in the 1206 grid and the cartridge shell is
rotated to be parallel to the grid lines. The cartridge head is
moved out or in such that the stylus touches point 1207. The
tonearm is then swung to grid 1204 and the process checked for the
stylus touching point 1205 and the cartridge shell remaining
parallel to the grid lines. Upon achieving alignment, the cartridge
is tightened to lock the calibration and the tonearm is ready to be
used for the outer sector playback of a phonograph record with
minimum tracking error and concomitant distortion.
[0037] FIG. 13 illustrates a core advantage enabled by the
invention which is the ability to seamlessly combine the audio
signals picked by each of a plurality of independently calibrated
tonearms. This example plots the graph of a two tonearm embodiment
with each such tonearm specifically optimized for a specific subset
of the area on the recording as explained above. By seamlessly
splicing or stitching the digital recording of the outer tonearm to
the inner tonearm at the appropriate crossover point 1303 (95 mm
from the spindle in this example), the two sections are combined
resulting in a nearly uniformly low tracking error and concomitant
distortion.
[0038] FIG. 14 is a graph of the complete recording of a side of a
phonograph record resulting from combining two tonearms recorded
output as shown in FIG. 13. As can be seen, the result is a
tracking distortion across the entire recorded surface that is no
higher than 0.2% at any point and considerably lower than a single
tonearm.
[0039] FIG. 15 is a schematic diagram and flow chart providing an
overview of one exemplary version of the Invention using the
two-tonearm embodiment. The record being played back 1501 is
positioned on a turntable 1500 equipped with two pivoting tonearms
in this example, and two matching cartridges, 1513a and 1513b. The
tonearms are each associated with the stepping motor means of the
Invention 1502a and 1502b to aid in positioning. Each tonearm is
further associated with a lifting means 1512a and 1512b to further
automate the positioning of the tonearm, more detail of which may
be found in FIG. 20. The dotted line 1514 designates the
approximate boundary between the recorded area covered by the outer
tonearm 1513b and the inner tonearm 1513a. An optical monitoring
means 1511 provides imagery to the recording system controller 1505
to facilitate precise monitoring and positioning functionality. The
stereo output of each of the cartridge systems on the tonearms is
amplified by 1503a and 1503b respectively, and converted to a
digital signal in 1504a and 1504b respectively, the outputs of
which are both sent to the digital audio recording system 1506. The
output of 1506 is then sent to 1507, the digital audio noise
removal means of the Invention, and then to 1508, the digital audio
stitching means of the Invention which makes the "splice" 2104,
shown in FIG. 21. Output of 1508 is then stored in 1509 and
converted back to analog for playback 1510.
[0040] FIG. 15b is a schematic of an alternative embodiment where
only one tonearm is digitized at a given time. An analog switch
1525 is utilized to select one of a multiplicity of tonearm audio
signals from amplifier means 1523a or 1523b, in this embodiment.
The Recording System Control (RSC) 1525 is programmed to cause the
selection of the appropriate audio input by means of control line
1527 when the respective tonearm is placed on the recorded surface
by said RSC. The output of the audio switch is applied to the input
of the ADC 1524a to be converted to a digital signal for further
processing.
[0041] FIG. 16 is a flowchart which defines a control flow for the
tonearm positioning servo system. Said system utilizes
computer-numerically-controlled (CNC) system means to position the
tonearms of the invention and to lift and return said tonearms to
rest position at the end of each respective recording track.
[0042] FIG. 17 is a flowchart which defines a control flow for the
optical recognition process to detect and direct tonearm CNC system
to move respective tonearms into position, lower said tonearms and
then lift and return said tonearms to resting position.
[0043] FIG. 18 illustrates the optical monitoring device, 1801
which is employed to monitor the positions of tonearms 1802 and
1805. As further labeled and detailed in FIG. 2 using the two
tonearm embodiment as an example, the movement of the outer tonearm
1802 traverses the area from the lead-in groove across a
pre-designated area from position 1804 to 1803. The inner tonearm
1805 traverses from position 1806 to 1807, exiting at the lead-out
groove. An image recognition system of the invention monitors the
tonearm position to provide precise position information to the
control system of the invention for the purposes of initially
positioning each tonearm of the invention then signaling when each
tone arm has reached the end of its respective recording track.
[0044] FIG. 19 provides a more detailed schematic of the mechanical
tonearm lifting component of the invention. In this depiction of a
two tonearm embodiment of the invention, the lifter 1901 engages
the outer tonearm 1904 to and lifter 1902 engages the inner tonearm
1905 for the purpose of raising, positioning and lowering each
respective tonearm.
[0045] FIG. 20 is a further illustration of the mechanical tonearm
lifter component of the invention. This is a cross-section view
showing the turntable platter 2001 and the tonearm lifting means
with its associated tonearm as retained by the mechanism of the
apparatus (shown in cross section as 2007). The extension of the
lifter arm 2005 is controlled by horizontal drive apparatus 2008,
and its lifting and lowering of said tonearm is controlled by
vertical drive apparatus 2003.
[0046] FIG. 21 illustrates the process of combining the audio
signals 2101 and 2102 that are digitally recorded from each of the
tonearms. In this example of a two tonearm embodiment, an
autocorrelation method locates window 2103 in a region of precise
overlap of, for this example, the end of the outer tonearm
recording area with the start of the inner tonearm recording area.
Using said autocorrelation method, a precise location is found in
each audio recording track that becomes the splice point 2104 for
stitching segments into one continuous file.
[0047] FIG. 22 is a flowchart which depicts an audio segment
alignment process.
[0048] FIG. 23 is a graph of tracking error and harmonic distortion
of a three-arm tonearm assembly of FIG. 3 playing the outermost
section of a record at 403 of FIG. 4. In this example, the area
between 2304 at about 150 mm, which is the lead-in groove, to 2303
which is a point that is located at a distance of 120 mm from the
spindle. Observable is that the harmonic distortion is nearly
zero.
[0049] FIG. 24 is a graph of tracking error and harmonic distortion
of a three-arm tonearm assembly of FIG. 3 playing the outermost
section of a record section 404 of FIG. 4. In this example, the
area between 2404 at about 120 mm to 2403 which is a point that is
located at a distance of 90 mm from the spindle. Observable is that
the harmonic distortion is close to zero.
[0050] FIG. 25 is a graph of tracking error and harmonic distortion
of a three-arm tonearm assembly of FIG. 3 playing the outermost
section of a record at 405 of FIG. 4. In this example, the area
between 2504 at about 90 mm, which is the lead-in groove, to 2503
which is a point that is located at a distance of 60 mm from the
spindle, the lead-out groove. Observable is that the harmonic
distortion is nearly zero.
[0051] FIG. 26 illustrates an alternative embodiment of the
Invention using a single, self-aligning tonearm 2601 that is
configured to rotate the cartridge and stylus assembly in head
component 2602 by means of an offset angle alignment motor 2604
manipulating the rotatable cartridge angle control arm 2603 in such
a manner that the cartridge is maintained in an orientation that is
essentially tangential to the grooves at all times depending on the
section of the recording being played back. The lowering, lifting
and positioning of the tone arm for each adjustment for each
section of travel is automated by tonearm lifting device 2605 that
operates in a manner similar to that as depicted in FIG. 20.
[0052] FIG. 27 illustrates the principle of the operation of the
single self-aligning tonearm embodiment of the Invention. The
recorded surface of the subject recorded disk 2701 is divided into
a plurality of playback areas. In this example there are three: an
outer, middle and inner area. However, in this example, rather than
using the three tonearm embodiment of the invention as depicted in
FIGS. 3 and 4, a single self-aligning tonearm embodiment is used.
For each designated section of the recording area, the tone arm is
positioned by the tonearm lifting device as shown as 2605 in FIG.
26 while the angle of the head component (2602 in FIG. 26) is
adjusted by component 2604 in FIG. 26 to a position that is
calculated as appropriate for that specific section as depicted by
means of example only by angle 2702 of 20 degrees, 2703 of 16
degrees, and 2704 of 12 degrees. The corresponding overhand value
of the stylus is also set to achieve the optimal tracking accuracy
as taught by Baerwald, et al, for the appropriate null points of
each playback section (outer 2712, middle 2713 and inner 2714 in
this example).
[0053] FIG. 28 illustrates an operational flow representing example
operations related to playback of phonograph records.
[0054] FIGS. 29 to 35 illustrate alternative embodiments of the
operational flow of FIG. 28.
DETAILED DESCRIPTION OF THE INVENTION
[0055] As audio recording, storage and playback systems evolved
over the years, subtle noise and distortion artifacts secondary to
the technologies then available became more and more detectable to
certain classes of listeners. One of the most difficult of these
issues to address has been the artifacts inherent in the conflict
between the way audio information is recorded to analog audio
disks, and the way it is then played back.
[0056] Vinyl phonograph disks are pressed from molds of a master
disk that is cut by a mechanical lathe device; an example of which
is shown in FIG. 24. The cutting head is driven by a worm drive
across the surface of the disk, passing along a straight radial
path from the outermost to the innermost groove as diagramed in
FIG. 1b. A problem with playback tracking accuracy arises from the
traditional pivoting phonograph tonearm that has been in use in one
form or another for almost a century. As the stylus follows the
groove, the tonearm pivots causing the stylus to traverse a path
that is an arc with a radius proportional to the length of the
tonearm among other factors. The geometry of the typical phonograph
tonearm is illustrated in FIG. 5. The resultant path followed by
the stylus is an arc that intersects the straight path traversed by
the mastering process cutting head in only two locations, called
"null points" as shown as 510 and 509 in FIG. 5. The rest of the
time, the phonograph needle or stylus is unavoidably offset at an
adverse angle to the information recorded by the cutting tool used
to create the mastering record's groove. This so-called "tracking
error" introduces audible distortion in the playback of audio
records.
[0057] Much research in the first half of the twentieth century
went into determining optimal geometry to minimize said tracking
error and attendant distortion, see Ref 1. Lofgren, Ref 2.
Baerwald, Ref 3. Bauer. The general consensus from this research
resulted in recommendations to set an angular offset 507 of the
cartridge to the tonearm wand 501b and to establish an overhang 508
where the stylus point 512 follows an arc of a radius greater than
the pivot to spindle distance 503, as identified in FIG. 5. The
mathematical formulas to determine these settings as depicted in
FIG. 6 were established by the authors of the aforementioned
references, among others.
[0058] Applying the formulas in FIG. 6 can change the degree to
which the tracking error occurs, as shown in comparing FIG. 7 and
FIG. 8. These two figures graph the tracking error and resulting
harmonic distortion generated as a result of the tracking error.
Because of the complex interactions of the multiple geometric
shapes and relationships in play, a very subtle change in tonearm
geometry can result in significant alterations in tracking errors
and distortion. This can be readily seen by again comparing FIG. 7
depicting an example of what is known as the Baerwald geometry.
This configuration is one of the most popular tonearm
configurations in use with contemporary turntables. In this
alignment, the peak harmonic distortion is plotted at three points
where 701 is the outer groove, 702 is the peak of distortion found
about two-thirds of the distance toward the end of the recording
from the outer groove and 703 is the distortion at the end of the
recording. The intent of this Baerwald configuration is to adjust
said overhang and said offset angle such that said distortion is
equal at each of said three peak points. The graph of FIG. 8 plots
another popular geometry known as Lofgren. In this configuration,
the root-means-square (RMS) average of distortion is equal in each
of three areas of the recording. Said areas are from the lead-in
groove 801 to the outer null point 805 is the first section, then
between outer 805 and inner 806 null points and finally between
inner null 806 and lead-out groove 807. The result of this
configuration is the harmonic distortion is minimized for most of
the recording surface at the expense of the beginning and the end
of said recording. Some audiophiles and recording engineers prefer
Baerwald and others prefer Lofgren. There are several other
configurations that have some popularity. In all of the useful
configurations, a less than 3% change in just the metric describing
the overhang of the cartridge, results in changes in said
distortion characteristics as a direct result of affecting the
tracking error. However, no matter how carefully the pivoting
tonearm is calibrated, it is geometrically impossible to make any
arc intersect with a straight line except at two points and, hence,
no configuration can achieve uniformly low tracking error from a
pivoting tonearm.
[0059] In an attempt to address this issue, various types of what
are known as linear tonearms have been proposed. These playback
systems, similar to one pictured in FIG. 25, seem an ideal solution
at first glance. Unlike with a pivoting tonearm, the cartridge with
its stylus moves along a path essentially identical to the path
traversed by the mastering lathe system's cutting head. Said
tracking error of said playback system should be zero.
[0060] Though track error is indeed minimal, unfortunately the
various implementations of the design of linear tonearms have been
compromised by other mechanically induced problems result in new
sources of distortion and noise. One source of distortion is from
the shuttle assembly 2501 in FIG. 25. This shuttle cannot guide the
cartridge and needle across the record with perfectly even friction
as said assembly moves across the surface of the phonograph record.
The most audible side effect is caused by the side-loading pressure
exerted against the stylus by the groove wall. Said pressure is the
only force available to move the entire assembly of the shuttle,
tonearm and cartridge of said linear tonearm implementation. Said
pressure is conveyed from the stylus up the flexible cantilever to
the cantilever mount in the phonograph cartridge then up the
tonearm to the shuttle. It is important to understand that the
original record cutting lathe used a precision worm drive to propel
the cutting head assembly across the radius of the recording area
and, hence, the cutting needle was free to cut a precise and
tangentially perfect representation of the instantaneous audio
information. The cutting needle, hence, had no propulsion duties to
interfere with its job of impressing the analog audio information
into the groove walls of the record.
[0061] Therefore, to be able to create optimal high-resolution
digital recordings from traditional vinyl or similar phonograph
records, there is a clear need for a method and apparatus that can
reduce tracking error distortion to below perceptual levels while
not introducing yet other source of noise artifacts. By equipping a
phonograph turntable playback system with multiple tonearms, the
methods of the invention minimize the length of the mathematical
arc that each cartridge's stylus inscribes relative to the path
taken by the original cutting head on the record mastering process.
The systems of the invention further detect and optimize the area
of the arc with the least tracking error and distortion for each of
the tonearms of the invention. For a two-arm embodiment, FIG. 9
shows a plot of tracking area and resulting low harmonic distortion
in the area of recording from position 901 to position 903. The
protractor diagrammed in FIG. 10 sets the geometry for the outer
tonearm to achieve the desired characteristics for this region of
the phonograph record. Likewise, FIG. 11 represents a plot of the
tracking area and resulting low harmonic distortion in the area of
recording from position 1101 to position 1103. The protractor
diagrammed in FIG. 12 sets the geometry for the inner tonearm to
achieve the desired characteristics for this region of the
phonograph record.
[0062] The most optimal tracking results from the different tonearm
configurations at different portions of the arc are then
mathematically identified and may be combined into one
minimally-distorted result as shown in FIGS. 13 and 14. The
invention can be optimally utilized with all tonearms of the
particular embodiment recording simultaneously. The invention
provides a means to digitally record the output of each tonearm.
Once recorded, the system of the invention then identifies an
appropriate match point within the overlap of two adjacent digital
recordings as shown in FIG. 21, using auto-correlation for
example.
[0063] FIG. 15 illustrates a semi-automated system and apparatus
that realizes the invention as an integrated, fully-operating
system. Though showing an example embodiment with two tonearms,
systems with more than two tonearms are equally applicable. The
upper limit is simply where the tonearms have space to operate
without touching one another. In FIG. 15, the two tonearms, 1502a
and 1502b, are mechanically positioned as well as lifted and
lowered by a motorized means of 1512a and 1512b. A more detailed
view of said motorized means is shown in FIG. 20. In this
embodiment, an optical sensing means, 1511, is used to guide the
tonearm positioning means as well as to detect start and stop
points of the recording arc of each pivoting tonearm. This optical
means is typically a video camera, which provides a continuous
video image to the recording system controller (RSC) means, 1505.
The RSC is a computer subsystem that, among other things, employs
optical recognition means to detect tonearm position and to provide
trigger information to another subsystem for controlling tonearm
management (lifting and positioning as further shown in FIG. 20.)
Yet another subsystem of the RSC is computer numerically controlled
(CNC) system to provide control of the motor assembles used to
lift, lower and position the tonearms. Further, the tonearms could
be manually controlled by a human operator but at a great loss of
efficiency and possible increase in mechanical errors.
[0064] Video camera 1511 can also provide utility by providing a
picture of the vinyl LP record surface so that a control system of
the invention operating in the RSC can identify the individual
tracks of the record, when present, to be supplied to a subsequent
control module that finds and tags the individual audio bands on
said record. This tagging scheme is by means of identifying and
measuring the position of the silence between bands of a record
where said silence is typically visual to the unaided eye as dark
strips between songs. Additionally, camera 1511 can provide video
information to a speed control module program which measures
rotation of the turntable platter and can provide a servo control
of the turntable motor to maintain precise rotation speed
(typically 331/3 or 45 rpm.) Yet additionally, camera 1511 can be
utilized to take a picture of the record label to supply an optical
character recognition means of the RSC to extract metadata from
said label to identify the tracks of an audio recording. Camera
1511 can also provide visual information to a digital
identification means to find and record the lacquer identification
code which provides the provenance of the respective disk's master
recording.
[0065] It should be understood that an advantage of the invention
of using mechanical position means such as the computer controlled
positioning mechanism of FIGS. 19 and 20 in conjunction with the
optical position recognition system of FIG. 18 is to provide
optimal playback quality by abstaining from employing any
additional friction inducing sensory mechanisms to detect the
tonearm positions both for entry into the respective playback area
as well as to detect the point at which the tonearms are to be
withdrawn. In prior phonograph playback systems that employ
automated tonearm lowering and raising, mechanical means of sensing
the tonearm position are employed causing non-uniform pressure on
the tonearm and adversely affection playback audio quality.
[0066] Each phonograph cartridge of the invention is connected to
an amplification means 1503a and 1503b, which is then connected to
respective analog-to-digital converter (ADC) 1504a and 1504b. The
digital audio output of the ADC is then captured and stored by the
digital audio recording subsystem 1506 which then tags (identifies)
and stores the resultant recordings. FIG. 15a depicts an
alternative embodiment where the system of the invention employs
only one analog-to-digital converter 1524 made possible by the
addition of an analog signal switch 1526 which is controlled by the
Recording System Controller 1525 to select one at a time of the
plurality of input signals from each respective tonearm. In this
example, the system selects from one of two tonearm assemblies,
1523a and 1523b. The system of the invention then records
sequentially the output of each of the plurality of tonearms for
further processing.
[0067] The next stage of processing is the Digital Audio Noise
Reduction System 1507 which analyses the recorded audio to remove
clicks and pops from the audio by digital signal processing. This
is followed by the Digital Audio Stitching System 1508 which uses
the splice point data supplied by RSC and then determines the
precise byte aligned splice point to join two files. The process is
repeated for each recorded sector resulting in one file
representing the recorded digital audio of the respective side of
the audio record. FIG. 21 illustrated two sample audio segments of
overlapping sections of a phonograph recording. The audio signal
2101 depicts the end of the recording of the outer tonearm such as
the area of playback 203 of FIG. 2. The audio signal 2102 depicts
the overlapping recorded area of the inner tonearm of playback area
204 of FIG. 2. By means of an auto-correlation signal processing
algorithm, the overlapping areas of 2101 and 2102 are precisely
aligned even though each signal was derived from a separate
tonearm. If examined closely, each overlapping area would be
digitally converted with differing information due to random noise
of the system as well as such factors as differing dirt accumulated
on each respective playback stylus. However, the mathematical means
of auto-correlation will average out such stochastic differences
rending a virtually perfect alignment of the two recordings such
that an advantageous splice point may be found for joining the two
segments as shown at 2104 of FIG. 21.
[0068] The resulting file is then stored in data storage 1509 and
can also be played back in near real time via digital-to-analog
converter 1510 or sent over a local area network 1511 to another
system. For the purposes of immediate playback, the system of the
invention can begin playing back the recorded audio from the first
tonearm of the outer-most sector. The second and, if present,
additional tonearms also record simultaneously. The second and
possible additional sectors will provide enough recorded
information to allow the system to detect the start point of each
recording and prepare to byte-accurately splice said start point of
the second recorded section to the end of the recorded first
section. By the end of the first recording section, the remaining
section(s) will have also completed or nearly completed. In the
presence of more than two sections, all sections will have
typically concluded recording before the second section completes
playback. Hence, all subsequent recorded sections, if present, are
simply digitally spliced to the end of the respective previous
section to form a complete recording of the selected side of the
record.
[0069] An improvement to the apparatus of the invention would be
the addition of a robotic arm to place the record on the turntable
from a record storage shelf means. The robotic arm could also be
employed to flip the record to its opposite side for the recording
of said side and then replace said record back on the record
storage shelf and another record would be selected and placed on
the turntable analogous to the jukebox mechanisms popular from the
1940's to the 1960's.
[0070] A further improvement of the invention is the process of
rotating the turntable platter at one-half speed to playback the
phonograph record at half the frequency of the original recording.
By means of example, a piano note played on the major scale of
middle A of 440 hertz would sound one octave lower at A 220 Hertz.
The advantage of this half=speed playback would be to obtain a more
accurate transcription of the phonograph record as the playback
stylus is moving at one-half the linear velocity of normal playback
and hence tracing the mechanical undulations of the recorded
surface with additional accuracy. This additional accuracy results
from less unwanted ringing of the cantilever to which the playback
stylus is attached as well as to greater accuracy of the playback
stylus following the impressions on the groove wall of the audio
information. The system of the invention would apply an addition
processing step of frequency doubling by means of digital
up-conversion to restore the audio signal to its original frequency
range as would be heard at normal playback speeds. The result of
the process using the previous example would be the piano note of
the example sounding at A 220 hertz would post processing then
sound at note A 440 hertz as intended by the recording. Frequency
doubling may also be referred to as up-conversion.
[0071] The method and apparatus of the invention as described
herein thereby enables the recording of a perceptually seamless
high-definition digital audio facsimile with an average tracking
distortion that is both relatively mathematically even and
quantifiably well below known human perception thus enabling a
previously unattainable quality of digital recordings of phonograph
records for many uses such as re-mastering new vinyl LP records or
for the sale of digital copies of said media.
[0072] FIG. 28 illustrates a system and/or an operational flow 2800
representing example circuitry, means and/or operations related to
playback of phonograph records. In FIG. 28 and in following figures
that include various examples of circuitry, means and/or
operational flows, discussion and explanation may be provided with
respect to the above-described examples of FIGS. 1 through 27,
and/or with respect to other examples and contexts. However, it
should be understood that the circuitry, means and/or operational
flows may be executed in a number of other environments and
contexts, and/or in modified versions of FIGS. 1 through 27. Also,
although the various circuitry, means and/or operational flows are
presented in the sequence(s) illustrated, it should be understood
that the various procedures carried out by circuitry or means
and/or the operational flows may be performed in other orders than
those which are illustrated, or may be performed concurrently.
"Operational flow" as used herein may include circuitry for
carrying out the flow; hence, FIGS. 1 through 27 reference
"circuitry configured for" performing a procedure. A processing
device, such as a microprocessor, may, via execution of one or more
instructions or other code-like appurtenances, become "circuitry
configured for" a particular operation. An operational flow as
carried out by a processing device would render the processing
device "circuitry configured for" carrying out each operation via
execution of the one or more instructions or other
appurtenances.
[0073] After a start operation, the operational flow 2800 moves to
operation 2810. Operation 2810 depicts circuitry configured for
obtaining a first audio segment associated with a first recording
area of a phonograph record. For example, as shown in and/or
described with respect to FIGS. 1 through 27, an audio segment may
be obtained via a tonearm, the tonearm having been placed at a
particular point on the phonograph record perhaps by the optical
monitoring device in conjunction with the mechanical tonearm
lifting component discussed in relation to FIG. 19. In certain
embodiments, the tonearm is configured for a particular geometry
and optimized for reduced distortion during playback of a
particular recording area of the phonograph record.
[0074] Then, operation 2820 depicts circuitry configured for
obtaining at least a second audio segment associated with at least
a second recording area of the phonograph record, the second
recording area at least partially overlapping with the first
recording area. For example, as shown in and/or described with
respect to FIGS. 1 through 27, at least a second audio segment is
obtained via at least a second tonearm. As discussed relative to
FIG. 27, "at least a second audio segment" could include a second,
third, fourth, or any number of audio segments obtained via any
number of tonearms, up to a practical size limit of tonearms that
could be fitted to the apparatus. At least a portion of the first
recording area overlaps with at least a portion of the second
recording area. In some embodiments, at least a portion of the
second recording area overlaps with at least a portion of the third
recording area. One result is that, for example, the first audio
segment will have a portion near its beginning or end which
correlates with a portion of the second audio segment near its
beginning or end. A first portion may relate to an outermost
recording area or an innermost recording area. If a first portion
relates to an outermost recording area and the second portion is an
inner recording area, then a portion towards the end of the first
audio segment will correlate with a portion of the beginning of the
second audio segment. An outer recording area may run from an outer
groove radius of 150 to an inner groove radius of 90; an inner
recording area may run from an outer groove radius of 110 to an
inner groove radius of 56. Thus, the second recording area (the
inner recording area in this example) overlaps the first recording
area in that they both span from 90 to 110 units. Sound played back
in this 90 to 110 unit zone may be correlated in the first and
second audio segments using operations disclosed elsewhere
herein.
[0075] Then, operation 2830 depicts circuitry configured for
stitching the first and the at least a second audio segment. For
example, as shown in and/or described with respect to FIGS. 1
through 27, the first and second audio segments are aligned (the
aligned portion relating to the overlap--the 90 to 110 unit zone in
the example of the previous paragraph). A point within the overlap
is selected. A continuous stream is assembled by concatenating the
first segment up to the selected point with the second segment from
the selected point on. In a three audio segment embodiment, the
process is repeated whereby a point is selected in the overlap
between the second and third audio segments, and the second segment
up to the selected point is concatenated with the third segment
from that selected point. The operational flow then proceeds to an
end operation.
[0076] The point selected for stitching and/or concatenating audio
segments may be any point along the aligned audio sections
correlating with the overlapping recording areas. Using operations
and/or other subject matter disclosed herein, a splice point is
selected to minimize audible detection of the transition between
audio segments by a listener. In some embodiments, the point may be
where waveform representations of the audio segments match. A "zero
point" where minimum transience is sought, in which amplitudes of
the wave representations of the audio segments cross over at zero.
In some embodiments, a splice point may also or alternatively be
where the distortion is equal in both audio segments.
[0077] Notably, the segments are not required to be obtained by
separate tonearms. In some embodiments in which the benefit of
reduced distortion is desired but multiple tonearms are not present
(e.g. embodiments like those discussed with respect to FIG. 15b), a
single tonearm version of the device with adjustable angle,
overhang and other tonearm aspects could be implemented in which
the first operation 2810 would set calibrations of the single
tonearm for the first recording area and the first audio segment
would be obtained, then the second operation 2820 would set
calibrations for the second recording area (perhaps first lifting
the tonearm) and the second audio segment would be obtained (the
first and second segments at least partially overlapping), and the
first and second segments would be stitched. Such a single-tonearm
embodiment might be a pivoting tonearm or a linear tonearm system.
One possible downside is the new distortion which could be
introduced by mechanisms for adjusting the single tonearm
cartridge. (Such downsides may be minimized through use of a linear
system or other means.) Further, multiple tonearms have the benefit
of drawing in a side of a phonograph record more quickly than a
single tonearm embodiment, but a single tonearm system with
adjustable cartridge would function via making the tonearm
calibration adjustment during the playback. In either of a single-
or multiple-tonearm version, stitching the segments provides the
benefit of reduced distortion.
[0078] FIG. 29 illustrates alternative embodiments of the example
operational flow 2800 of FIG. 28. FIG. 29 illustrates an example
embodiment where operational flow 2810 may include at least one
additional operation. Additional operations may include operation
2910, 2920, 2930, 2940, and/or 2950.
[0079] Operation 2910 illustrates circuitry configured for
receiving an indication of at least an outer groove radius and an
inner groove radius associated with the first recording area. For
example, as shown in and/or described with respect to FIGS. 1
through 27, a control system may read parameters which define a
first recording area as an outermost recording area of a phonograph
record. The parameters would define an outer and inner radius from
a spindle, between which is defined a thickness of a concentric
portion of the phonograph record.
[0080] Then, operation 2920 illustrates circuitry configured for
obtaining the first audio segment at least partially via traversing
a radial distance between the outer groove radius and the inner
groove radius associated with the first recording area. For
example, as shown in and/or described with respect to FIGS. 1
through 27, a tonearm may be moved to the outer groove radius of
the first recording area and placed onto the phonograph record. The
turntable may be spun at an appropriate RPM (revolutions per
minute) for the type of phonograph record, and the tonearm would
read data contained in the grooves within the concentric band. The
first audio segment may be stored as it is read in a non-transitory
data medium of the system for later splicing with the second audio
segment, perhaps after being amplified via the two-channel
amplifier and converted to digital data by an analog-to-digital
converter as disclosed with respect to FIG. 15. In some
embodiments, data read by the tonearm is monophonic, stereophonic,
quadraphonic, or another type of data.
[0081] Operation 2910 may include at least one additional
operation. Additional operations may include operation 2930 and/or
2940.
[0082] Operation 2930 illustrates circuitry configured for
receiving a distance between a spindle center and an outer boundary
of the first recording area as the outer groove radius. For
example, as shown in and/or described with respect to FIGS. 1
through 27, a control system may read parameters which define a
first recording area. In some embodiments, the parameters could
include an outer groove radius representing a distance from the
center of a spindle, which may be, for example 150 units.
[0083] Operation 2940 illustrates circuitry configured for
receiving a distance between the spindle center and an inner
boundary of the first recording area as the inner groove radius. In
some embodiments, as shown in and/or described with respect to
FIGS. 1 through 27, when the control system reads the parameters
defining the first recording area, the parameters could include an
inner groove radius representing a distance from the center of the
spindle, which may be, for example, 90 units. The first recording
area would thus be a concentric ring having a thickness of 60
units.
[0084] Operation 2920 may include at least one additional
operation. Additional operations may include operation 2950.
[0085] Operation 2950 illustrates circuitry configured for
controlling a first tonearm to receive audio data recorded between
the outer groove radius and the inner groove radius associated with
the first recording area, the first tonearm associated with one or
more first recording area calibrations related to distortion
reduction. In some embodiments, as shown in and/or described with
respect to FIGS. 1 through 27, the first tonearm may be associated
with calibration values designed to minimize distortion within the
first recording area. As discussed elsewhere herein, by configuring
a tonearm to read only a portion of the total recording area of a
phonograph record, distortion may be reduced in some instances by
an order of magnitude. Using calibration values calculated for a
tonearm arc covering only that particular concentric band is
discussed, for example, in FIGS. 10 and 11. In different
embodiments, the tonearms are not calibrated for a particular band;
the multiple tonearms are used to obtain an audio stream of the
side of the phonograph record more quickly than the single tonearm
player as digital signal processing is used to stitch together
audio segments obtained by the multiple tonearms using operations
disclosed herein such as aligning the multiple audio segments,
finding a point and concatenating about that point.
[0086] FIG. 30 illustrates alternative embodiments of the example
operational flow 2800 of FIG. 28. FIG. 30 illustrates an example
embodiment where operational flow 2820 may include at least one
additional operation. Additional operations may include operation
3010, and/or 3020.
[0087] Operation 3010 illustrates circuitry configured for
receiving an indication of at least an outer groove radius and an
inner groove radius associated with the second recording area, the
outer groove radius associated with the second recording area
outside of an inner groove radius associated with the first
recording area. For example, as shown in and/or described with
respect to FIGS. 1 through 27, a control system may read parameters
which define a second recording area as an innermost recording area
of a phonograph record (or at least a recording area which is a
concentric band positioned closer to the spindle than the first
recording area, as disclosed elsewhere herein are embodiments in
which the phonograph record is mapped into three recording areas).
The parameters would define an outer and inner radius from a
spindle, between which is defined a thickness of a concentric
portion of the phonograph record for the second recording area. In
some embodiments, an outer radius from the spindle of the second
recording area is greater than the inner radius from the spindle of
the first recording area, the difference between the two
correlating with the overlap between the first and second recording
areas.
[0088] Then, operation 3020 illustrates circuitry configured for
obtaining the second audio segment at least partially via
traversing a radial distance between the outer groove radius and
the inner groove radius associated with the second recording area.
For example, as shown in and/or described with respect to FIGS. 1
through 27, a tonearm may be moved to the outer groove radius of
the second recording area and placed onto the phonograph record.
The turntable may be spun at an appropriate RPM (revolutions per
minute) for the type of phonograph record, and the tonearm would
read data contained in the grooves within the concentric band
defining the second recording area. The second audio segment may be
stored as it is read in a non-transitory data medium of the system
for later splicing with the first audio segment, perhaps after
being amplified via the two-channel amplifier and converted to
digital data by an analog-to-digital converter as disclosed with
respect to FIG. 15. In some embodiments, data read by the tonearm
is monophonic, stereophonic, quadraphonic, or another type of
data.
[0089] FIG. 31 illustrates alternative embodiments of the example
operational flow 2800 of FIG. 28. FIG. 31 illustrates an example
embodiment where the combined operational flows 2810 and 2820 may
include one or more alternative operations 3110.
[0090] Operation 3110 illustrates circuitry configured for
obtaining the first audio segment at least partially via a first
tonearm associated with one or more first calibrations related to
distortion reduction within the first recording area and circuitry
configured for obtaining the second audio segment at least
partially via a second tonearm associated with one or more second
calibrations related to distortion reduction within the second
recording area. For example, as shown in and/or described with
respect to FIGS. 1 through 27, a first tonearm may be calibrated
for distortion reduction specific to a first recording area and/or
an arc traveled by the first tonearm while reading from within the
first recording area, while a second tonearm may be calibrated for
distortion reduction specific to a second recording area and/or an
arc traveled by the second tonearm while reading from within the
second recording area. Utilizing two tonearms facilitates obtaining
an audio representation of the side of the phonographic record
quicker than a single tonearm embodiment, and as discussed
elsewhere herein, by digitally combining audio segments obtained by
the tonearms which are individually reduced in distortion by virtue
of the calibrations of the tonearms, the combined audio
representation is also reduced in distortion relative to a single
tonearm embodiment where the single tonearm reads the entire
recording area of the side of the phonograph record.
[0091] FIG. 32 illustrates alternative embodiments of the example
operational flow 3110 of FIG. 31. FIG. 32 illustrates an example
embodiment where operational flow 3110 may include at least one
additional operation. Additional operations may include operation
A32: 3210, 3220, and/or 3230, and/or B32: 3240, 3250, 3260, and/or
3270.
[0092] Operation 3210 illustrates circuitry configured for
controlling a start location of the first tonearm. For example, as
shown in and/or described with respect to FIGS. 1 through 27, a
control system may operate a means for lifting the first tonearm
and moving the first tonearm to a start location, which may be a
received outer groove radius corresponding to the first recording
area. The first tonearm (also the second and any additional
tonearms) may be a free-swiveling tonearm, with no mechanical
sensors or mechanical drive means permanently coupled to the swivel
or tonearm means. Mechanical sensors or mechanical drive means
could, if present, introduce additional sources of distortion.
[0093] Then, operation 3220 illustrates circuitry configured for
controlling a start location of the second tonearm. For example, as
shown in and/or described with respect to FIGS. 1 through 27, a
control system may operate a means for lifting the second tonearm
and moving the second tonearm to a start location, which may be a
received outer groove radius corresponding to the second recording
area. The second tonearm (also the first and any additional
tonearms) may be lifted by a mechanical lifter component, which
lifts the tonearm using a vertical drive apparatus and moves the
tonearm laterally using a horizontal drive apparatus. Utilizing the
lifter provides the benefit of not requiring permanent attachment
of mechanical sensors or drive means to the tonearm which could
introduce distortion, but also enables the tonearm positioning to
be automatic. The lifter means may also be used when the tonearm
reaches the end of a recording area to return the tonearm to an
initial position and/or to move the tonearm to any position over
the phonograph record.
[0094] Then, operation 3230 illustrates circuitry configured for
obtaining at least a portion of the first audio segment associated
with the first tonearm concurrent with obtaining at least a portion
of the second audio segment associated with the second tonearm. For
example, as shown in and/or described with respect to FIGS. 1
through 27, a control system may initiate the rotation of the
turntable supporting the phonograph record, either prior to,
concurrent with, or subsequent to the tonearms being positioned at
the start location. As the tonearms traverse the recording area
along their respective grooves, the audio data embedded in the
recording areas is read by the tonearms. Audio segments are
produced (which may involve amplification and analog-to-digital
conversion operations and/or circuitry) and provided to a
non-transitory data store.
[0095] Operation 3240 illustrates circuitry configured for
controlling a start location of the first tonearm. For example, as
shown in and/or described with respect to FIGS. 1 through 27, a
control system may use an optical image sensor to obtain a location
of the first tonearm (also the second or any additional tonearms).
A portion of the first tonearm may be provided with a particular
visual cue for ease of optical image recognition by the control
system. Recognizing that phonograph records are predominantly black
in color and so are many tonearm cartridges, a top surface may be
provided with a white index line to aid an optical recognition
component in converting a visual picture of the tonearm's location
to a value which can be used by the control system to determine
movement required for positioning the tonearm at the start
location.
[0096] Then, operation 3250 illustrates circuitry configured for
controlling a start location of the second tonearm. For example, as
shown in and/or described with respect to FIGS. 1 through 27, a
control system may use the optical image sensor, which can be a
camera coupled with the control system in a wired or wireless
fashion, to provide a location of the second tonearm (also the
first or any additional tonearms). The optical image sensor may be
a video camera and/or be a camera configured for detecting
infrared, ultraviolet or other frequencies which may be visible or
invisible to the human eye. Data from the optical image sensor may
be used to assist in movement of the second tonearm to the start
location. A rotation speed for the turntable could be determined
partially using data from the optical image sensor detecting a size
of the phonograph record (e.g. if data from the sensor indicates
that a 7'' phonograph record is on the turntable, a speed of 45 rpm
could be selected).
[0097] Then, operation 3260 illustrates circuitry configured for
obtaining the first audio segment associated with the first
tonearm. For example, as shown in and/or described with respect to
FIGS. 1 through 27, a control system may initiate the rotation of
the turntable supporting the phonograph record, either prior to,
concurrent with, or subsequent to the first tonearm being
positioned at the start location. The first tonearm may obtain the
first audio segment at a time other than a time at which the second
tonearm obtains the second audio segment.
[0098] Then, operation 3270 illustrates circuitry configured for
obtaining the second audio segment associated with the second
tonearm subsequent to obtaining the first audio segment associated
with the first tonearm. For example, as shown in and/or described
with respect to FIGS. 1 through 27, the first and second tonearms
may, in some embodiments, obtain a first and second audio segment
sequentially. In other words, the second tonearm may be inactive or
may be in motion responsive to the control system but not in
contact with the record while the first tonearm obtains its audio
segment corresponding to the first recording area, and the first
tonearm may be inactive or may be in motion responsive to the
control system but not in contact with the record while the second
tonearm obtains its audio segment corresponding to the second
recording area. As the tonearms traverse the recording area along
their respective grooves, the audio data embedded in the recording
areas is read by the tonearms. Audio segments are produced (which
may involve amplification and analog-to-digital conversion
operations and/or circuitry) and provided to a non-transitory data
store.
[0099] FIG. 33 illustrates alternative embodiments of the example
operational flow 2800 of FIG. 28. FIG. 33 illustrates an example
embodiment where operational flow 2810 may include at least one
additional operation. Additional operations may include operation
3310, 3320, 3330, 3340, and/or 3350.
[0100] Operation 3310 illustrates circuitry configured for
positioning a first tonearm in association with an outer groove
radius of the first recording area at least partially using at
least one image sensor. For example, as shown in and/or described
with respect to FIGS. 1 through 27, upon receiving parameters which
define a first recording area as an outermost recording area of a
phonograph record, the control system may receive data from the
optical sensor/video camera/image sensor which can be used to
determine a current position for the tonearm and a movement needed
to position the tonearm along the outer groove radius of the first
recording area (the lead-in groove, for example). The control
system may then command a mechanical lifter to position the tonearm
accordingly.
[0101] Then, operation 3320 illustrates circuitry configured for
controlling the first tonearm to receive audio data. For example,
as shown in and/or described with respect to FIGS. 1 through 27,
the rotation of the turntable causes the groove of the phonograph
record to pass underneath the tonearm. Audio data is picked up by
the tonearm, processed and stored.
[0102] Then, operation 3330 illustrates circuitry configured for
determining a relation between the first tonearm and the inner
groove radius of the first recording area at least partially using
the at least one image sensor. For example, as shown in and/or
described with respect to FIGS. 1 through 27, the optical sensor
may determine that the tonearm has arrived at an inner groove
radius using optical recognition operations disclosed elsewhere
herein.
[0103] Then, operation 3340 illustrates circuitry configured for
re-positioning the first tonearm responsive to the determined
relation. For example, as shown in and/or described with respect to
FIGS. 1 through 27, upon recognition using data from the optical
sensor that the tonearm is at or is near the inner groove radius
defining the end of the first recording area, a control system may
command a mechanical lifter to move laterally and vertically to
capture the tonearm and reposition it. The lifting component may
lift the tonearm from underneath. Alternatively, the lifting
component may incorporate a claw which descends from overhead and
grasps the tonearm to lift it away from the phonograph record. In
different embodiments, the claw may also be used to permit the
tonearm to descend, coming into contact with the phonograph record
or with a neutral position stand.
[0104] Optional operation 3350 illustrates circuitry configured for
tagging the received audio data in association with an indication
of the first tonearm passing a radius associated with the at least
a second recording area. For example, as shown in and/or described
with respect to FIGS. 1 through 27, upon the tonearm reaching or
nearly reaching the start of the second recording area, having
traversed the spiral groove from a position at or near the outer
groove radius, a tag associated with a time is set. In some
embodiments, a time at which the tonearm was placed at or near the
outer groove radius of the first recording area is set as a tag as
well. The tags are associated (stored in memory, for example) with
the audio recordings. The times at which the tonearm passes certain
groove radii are useful in aligning the first audio segment with
the second audio segment, the second audio segment having also been
duly tagged. For example, assume the beginning of the second
recording area is at 110 units, and the end of the first recording
area is at 90 units. The 110 unit mark therefore defines the outer
radius of the overlapping portion of the first and second recording
areas. Assume further that the first and second tonearms begin
recording at t=0, and that the first tonearm passes 110 units at
time t=100. An initial alignment of the two audio segments may be
determined by aligning the start of the second audio segment at the
t=100 mark relative to the first audio segment. The initial
alignment may be directly used to splice the segments together, or
the initial alignment may be a starting point for finding a more
desirable splice point (for example, at a portion in the two
segments where distortion is equal, or at another point at which
detection of the transition would be undetectable to a human
listener).
[0105] FIG. 34 illustrates alternative embodiments of the example
operational flow 2800 of FIG. 28. FIG. 34 illustrates an example
embodiment where operational flow 2830 may include at least one
additional operation. Additional operations may include operation
3410 and/or 3420.
[0106] Operation 3410 illustrates circuitry configured for
stitching an audio segment obtained from at least a portion of the
first recording area at least partially via a first tonearm
calibrated for distortion reduction within the first recording area
as the first audio segment with an audio segment obtained from at
least a portion of the second recording area at least partially via
a second tonearm calibrated for distortion reduction within the
second recording area as the second audio segment, the first and
second recording areas at least partially overlapping. For example,
as shown in and/or described with respect to FIGS. 1 through 27, a
continuous audio stream representing the audio recording present on
the side of the phonograph record may be produced at least
partially based on the first audio segment and the second audio
segment, the first and second audio segment corresponding with
first and second recording areas of the phonograph record and first
and second tonearms having been calibrated to reduce distortion
within the first and second recording areas. Upon splicing,
stitching and/or concatenating portions of the first audio segment
and second audio segment at an appropriate splice point, the
resulting continuous audio stream features distortion levels
similar to those of the individual audio segments, which may be an
order of magnitude less than an audio stream captured by a single
tonearm which is calibrated for the entire side of the phonograph
record. For example, as shown in and/or described with respect to
FIGS. 1 through 27, a continuous audio stream representing the
audio recording present on the side of the phonograph record may be
produced at least partially based on concatenation, splicing and/or
stitching portions of the first audio segment and the second audio
segment.
[0107] Optional operation 3420 illustrates circuitry configured for
outputting a continuous audio stream, including at least
concatenating a start portion of the first audio segment with an
end portion of the second audio segment at least partially based on
aligning overlapping portions of the first and second audio
segments and determining a splice point between the start portion
of the first audio segment and the end portion of the second audio
segment, the outputted continuous audio stream associated with
reduced distortion relative to an audio stream captured by a single
tonearm of the first and second recording areas of the phonograph
record. For example, as shown in and/or described with respect to
FIGS. 1 through 27, a continuous audio stream representing the
audio recording present on the side of the phonograph record may be
produced at least partially based on the first audio segment and
the second audio segment, the first and second audio segment
corresponding with first and second recording areas of the
phonograph record and first and second tonearms having been
calibrated to reduce distortion within the first and second
recording areas. Upon splicing, stitching and/or concatenating
portions of the first audio segment and second audio segment at an
appropriate splice point, the resulting continuous audio stream
features distortion levels similar to those of the individual audio
segments, which may be an order of magnitude less than an audio
stream captured by a single tonearm which is calibrated for the
entire side of the phonograph record.
[0108] FIG. 35 illustrates alternative embodiments of the example
operational flow 2800 of FIG. 28. FIG. 35 illustrates an example
embodiment where operational flow 2830 may include at least one
additional operation. Additional operations may include operation
3510, 3520, 3530, 3540, 3550, 3560, and/or 3570.
[0109] Operation 3510 illustrates circuitry configured for aligning
at least an end portion of the first audio segment with at least a
start portion of the second audio segment. For example, as shown in
and/or described with respect to FIGS. 1 through 27, timelines
associated with the first and second audio segments may be aligned
such that the overlap between the timelines, detected at least
partially using the optical sensor, represents the same or
substantially the same audio data (allowing for minor and mostly
human-inaudible differences in the first and second audio
recordings due to the different calibrations of the tonearms or
other factors). In most cases the alignment will result in an
ending portion of the first audio segment (which may be from groove
radius 110 to groove radius 90) overlapping with a beginning
portion of the second audio segment (which also may be from groove
radius 110 to groove radius 90).
[0110] Then, operation 3520 illustrates circuitry configured for
determining a splice point. For example, as shown in and/or
described with respect to FIGS. 1 through 27, a desirable splice
point is one at which a transition from the first audio segment to
the second audio segment is undetectable to the human ear.
[0111] Then, operation 3530 illustrates circuitry configured for
outputting a continuous audio stream associated with the obtained
first and second audio segments at least partially based on the
determined splice point. For example, as shown in and/or described
with respect to FIGS. 1 through 27, a continuous audio stream may
include the non-overlapping beginning portion of the first audio
segment, the overlapping portion of the first audio segment up to
the splice point, the overlapping portion of the second audio
segment beginning at the splice point, and the non-overlapping
ending portion of the second audio segment.
[0112] Operation 3510 includes optional operation 3540. Operation
3540 illustrates circuitry configured for aligning the at least an
end portion of the first audio segment with the at least a start
portion of the second audio segment at least partially based on at
least one tag associated with an indication of a first tonearm
passing a radius associated with the at least a second recording
area. For example, as shown in and/or described with respect to
FIGS. 1 through 27, an initial point along timelines corresponding
to the beginning of overlap in the first audio segment and second
audio segment may be determined using a stored tag which encodes a
time at which the first tonearm entered the area of overlap. The
entire timelines of both segments may then be aligned with respect
to the initial point. Alternatively, the initial point may
correspond to the ending of overlap in the first audio segment and
second audio segment, determined using a stored tag which encodes a
time at which the second tonearm left the area of overlap.
[0113] Operation 3520 includes optional operation 3550. Operation
3550 illustrates circuitry configured for determining a splice
point between the aligned at least an end portion of the first
audio segment and at least a start portion of the second audio
segment at least partially based on optically-detected data. For
example, as shown in and/or described with respect to FIGS. 1
through 27, a splice point may be a midway point between the
beginning of the overlap of the two audio segments and the ending
of the overlap of the two audio segments. Such a splice point may
or may not optimize the transition in that it may or may not result
in a human-inaudible transition from the first audio segment to the
second audio segment within the continuous audio stream.
Alternatives to the midway point for a splice point may be
determined as described elsewhere herein (for example, finding a
point within the two segments where distortion is equal, finding a
point within the two segments where amplitude of waveforms
representing the segments are equal, finding a point where
waveforms cross at zero, finding a point resulting in minimum
transience, etc.). The splice point may be based on
optically-detected data (such as a splice point correlated with
time-associated tags relating to when a first tonearm and second
tonearm crossed a specific point in the overlap area--the time
t=100 mark relative to the first audio segment, for example. A
point of interest at which time is marked when the first and second
tonearms pass as detected optically may be determined prior to
calibrating the tonearms based on calculations related to
optimizing the first and second recording areas. This may represent
the splice point, or the splice point may be moved forward or back
to optimize distortion reduction as discussed previously.
[0114] Operation 3530 includes optional operations 3560 and/or
3570. Operation 3560 illustrates circuitry configured for preparing
the continuous audio stream at least partially based on
concatenating a portion of the first audio segment ending at the
determined splice point and a portion of the second audio segment
beginning at the determined splice point. For example, as shown in
and/or described with respect to FIGS. 1 through 27, "excess" audio
(audio which is present in the first audio segment past the splice
point and audio which is present in the second audio segment
previous to the splice point) is discarded and the remainder of the
two segments is concatenated to form the continuous audio
stream.
[0115] Then, operation 3570 illustrates circuitry configured for
outputting the prepared continuous audio stream. For example, as
shown in and/or described with respect to FIGS. 1 through 27, the
continuous audio stream may be stored in one or more non-transitory
computer-readable medium. The continuous audio stream may be played
back over a speaker coupled with the apparatus (first passing
through at least a digital to analog converter), transmitted in
digital form via a wired or wireless network connection coupled
with the apparatus, and/or stored in either digital or analog form
in one or more removable or non-removable media coupled with the
apparatus. Digital audio noise removal techniques may be applied
either prior to stitching the portions of the audio segments
forming the continuous audio stream or following the stitching.
[0116] Certain aspects of the present invention include process
steps and instructions described herein in the form of an
algorithm. It should be noted that the process steps and
instructions of the present invention could be embodied in
software, firmware or hardware, and when embodied in software,
could be downloaded to reside on and be operated from different
platforms used by real-time network operating systems.
[0117] The present invention also relates to an apparatus for
performing the operations herein. This apparatus may be specially
constructed for the required purposes, or it may comprise a
general-purpose computer selectively activated or reconfigured by a
computer program stored in the computer. Such a computer program
may be stored in a computer readable storage medium, such as, but
is not limited to, any type of disk including floppy disks, optical
disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs),
random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical
cards, application specific integrated circuits (ASICs), or any
type of media suitable for storing electronic instructions, and
each coupled to a computer system bus.
[0118] Furthermore, computers or computing means referred to in the
specification may include a single processor or may employ
multiple-processor designs for increased computing capability.
[0119] The algorithms and displays presented herein are not
inherently related to any particular computer or other apparatus.
Various general-purpose systems may also be used with programs in
accordance with the teachings herein, or it may prove convenient to
construct more specialized apparatus to perform the required method
steps. The required structure for a variety of these systems will
appear from the description above. In addition, the present
invention is not described with reference to any particular
programming language or operating systems. It is appreciated that a
variety of programming languages and operating systems may be used
to implement the teachings of the present invention as described
herein.
[0120] The system and methods, flow diagrams, and structure block
diagrams described in this specification may be implemented in
computer processing systems including program code comprising
program instructions that are executable by a computer processing
system. Other implementations may also be used. Additionally, the
flow diagrams and structure block diagrams herein described
describe particular methods and/or corresponding acts in support of
steps and corresponding functions in support of disclosed
structural means, may also be utilized to implement corresponding
software structures and algorithms, and equivalents thereof.
[0121] Embodiments of the subject matter described in this
specification can be implemented as one or more computer program
products, i.e., one or more modules of computer program
instructions encoded on a tangible program carrier for execution
by, or to control the operation of, data processing apparatus. The
computer readable medium can be a machine readable storage device,
a machine readable storage substrate, a memory device, or a
combination of one or more of them.
[0122] A computer program (also known as a program, software,
software application, script, or code) can be written in any form
of programming language, including compiled or interpreted
languages, or declarative or procedural languages, and it can be
deployed in any form, including as a stand-alone program or as a
module, component, subroutine, or other unit suitable for use in a
computing environment. A computer program does not necessarily
correspond to a file in a file system. A program can be stored in a
portion of a file that holds other programs or data (e.g., one or
more scripts stored in a markup language document), in a single
file dedicated to the program in question, or in multiple
coordinated files (e.g., files that store one or more modules, sub
programs, or portions of code). A computer program can be deployed
to be executed on one computer or on multiple computers that are
located at one site or distributed across multiple sites and
interconnected by a suitable communication network.
[0123] The processes and logic flows described in this
specification can be performed by one or more programmable
processors executing one or more computer programs to perform
functions by operating on input data and generating output. The
processes and logic flows can also be performed by, and apparatus
can also be implemented as, special purpose logic circuitry, e.g.,
an FPGA (field programmable gate array) or an ASIC (application
specific integrated circuit).
[0124] The essential elements of a computer are a processor for
performing instructions and one or more memory devices for storing
instructions and data. Generally, a computer will also include, or
be operatively coupled to receive data from or transfer data to, or
both, one or more mass storage devices for storing data, e.g.,
magnetic, magneto optical disks, or optical disks. However, a
computer need not have such devices. Processors suitable for the
execution of a computer program include, by way of example only and
without limitation, both general and special purpose
microprocessors, and any one or more processors of any kind of
digital computer. Generally, a processor will receive instructions
and data from a read only memory or a random access memory or
both.
[0125] To provide for interaction with a user or manager of the
system described herein, embodiments of the subject matter
described in this specification can be implemented on a computer
having a display device, e.g., a CRT (cathode ray tube) or LCD
(liquid crystal display) monitor, for displaying information to the
user and a keyboard and a pointing device, e.g., a mouse or a
trackball, by which the user can provide input to the computer.
Other kinds of devices can be used to provide for interaction with
a user as well. For example, feedback provided to the user can be
any form of sensory feedback, e.g., visual feedback, auditory
feedback, or tactile feedback; and input from the user can be
received in any form, including acoustic, speech, or tactile
input.
[0126] Embodiments of the subject matter described in this
specification can be implemented in a computing system that
includes back end component(s) including one or more data servers,
or that includes one or more middleware components such as
application servers, or that includes a front end component such as
a client computer having a graphical user interface or a Web
browser through which a user or administrator can interact with
some implementations of the subject matter described is this
specification, or any combination of one or more such back end,
middleware, or front end components. The components of the system
can be interconnected by any form or medium of digital data
communication, such as a communication network. The computing
system can include clients and servers. A client and server are
generally remote from each other and typically interact through a
communication network. The relationship of client and server arises
by virtue of computer programs running on the respective computers
and having a client server relationship to each other.
[0127] The foregoing detailed description has set forth various
embodiments of the devices and/or processes via the use of block
diagrams, flowcharts, and/or examples. Insofar as such block
diagrams, flowcharts, and/or examples contain one or more functions
and/or operations, it will be understood by those within the art
that each function and/or operation within such block diagrams,
flowcharts, or examples can be implemented, individually and/or
collectively, by a wide range of hardware, software, firmware, or
virtually any combination thereof. In one embodiment, several
portions of the subject matter described herein may be implemented
via Application Specific Integrated Circuits (ASICs), Field
Programmable Gate Arrays (FPGAs), digital signal processors (DSPs),
or other integrated formats. However, those skilled in the art will
recognize that some aspects of the embodiments disclosed herein, in
whole or in part, can be equivalently implemented in standard
integrated circuits, as one or more computer programs running on
one or more computers (e.g., as one or more programs running on one
or more computer systems), as one or more programs running on one
or more processors (e.g., as one or more programs running on one or
more microprocessors), as firmware, or as virtually any combination
thereof, and that designing the circuitry and/or writing the code
for the software and or firmware would be well within the skill of
one of skill in the art in light of this disclosure. In addition,
those skilled in the art will appreciate that the mechanisms of the
subject matter described herein are capable of being distributed as
a program product in a variety of forms, and that an illustrative
embodiment of the subject matter described herein applies equally
regardless of the particular type of signal bearing media used to
actually carry out the distribution. Examples of a signal bearing
media include, but are not limited to, the following: recordable
type media such as floppy disks, hard disk drives, CD ROMs, digital
tape, and computer memory; and transmission type media such as
digital and analog communication links using TDM or IP based
communication links (e.g., packet links).
[0128] Those having skill in the art will recognize that the state
of the art has progressed to the point where there is little
distinction left between hardware and software implementations of
aspects of systems; the use of hardware or software is generally
(but not always, in that in certain contexts the choice between
hardware and software can become significant) a design choice
representing cost vs. efficiency tradeoffs. Those having skill in
the art will appreciate that there are various vehicles by which
processes and/or systems and/or other technologies described herein
can be effected (e.g., hardware, software, and/or firmware), and
that the preferred vehicle will vary with the context in which the
processes and/or systems and/or other technologies are deployed.
For example, if an implementer determines that speed and accuracy
are paramount, the implementer may opt for a mainly hardware and/or
firmware vehicle; alternatively, if flexibility is paramount, the
implementer may opt for a mainly software implementation; or, yet
again alternatively, the implementer may opt for some combination
of hardware, software, and/or firmware. Hence, there are several
possible vehicles by which the processes and/or devices and/or
other technologies described herein may be effected, none of which
is inherently superior to the other in that any vehicle to be
utilized is a choice dependent upon the context in which the
vehicle will be deployed and the specific concerns (e.g., speed,
flexibility, or predictability) of the implementer, any of which
may vary. Those skilled in the art will recognize that optical
aspects of implementations will typically employ optically-oriented
hardware, software, and or firmware.
[0129] The foregoing detailed description has set forth various
embodiments of the devices and/or processes via the use of block
diagrams, flowcharts, and/or examples. Insofar as such block
diagrams, flowcharts, and/or examples contain one or more functions
and/or operations, it will be understood by those within the art
that each function and/or operation within such block diagrams,
flowcharts, or examples can be implemented, individually and/or
collectively, by a wide range of hardware, software, firmware, or
virtually any combination thereof. In one embodiment, several
portions of the subject matter described herein may be implemented
via Application Specific Integrated Circuits (ASICs), Field
Programmable Gate Arrays (FPGAs), digital signal processors (DSPs),
or other integrated formats. However, those skilled in the art will
recognize that some aspects of the embodiments disclosed herein, in
whole or in part, can be equivalently implemented in standard
integrated circuits, as one or more computer programs running on
one or more computers (e.g., as one or more programs running on one
or more computer systems), as one or more programs running on one
or more processors (e.g., as one or more programs running on one or
more microprocessors), as firmware, or as virtually any combination
thereof, and that designing the circuitry and/or writing the code
for the software and or firmware would be well within the skill of
one of skill in the art in light of this disclosure. In addition,
those skilled in the art will appreciate that the mechanisms of the
subject matter described herein are capable of being distributed as
a program product in a variety of forms, and that an illustrative
embodiment of the subject matter described herein applies equally
regardless of the particular type of signal bearing media used to
actually carry out the distribution. Examples of a signal bearing
media include, but are not limited to, the following: recordable
type media such as floppy disks, hard disk drives, CD ROMs, digital
tape, and computer memory; and transmission type media such as
digital and analog communication links using TDM or IP based
communication links (e.g., packet links).
[0130] The herein described aspects depict different components
contained within, or connected with, different other components. It
is to be understood that such depicted architectures are merely
exemplary, and that in fact many other architectures can be
implemented which achieve the same functionality. In a conceptual
sense, any arrangement of components to achieve the same
functionality is effectively "associated" such that the desired
functionality is achieved. Hence, any two components herein
combined to achieve a particular functionality can be seen as
"associated with" each other such that the desired functionality is
achieved, irrespective of architectures or intermedial components.
Likewise, any two components so associated can also be viewed as
being "operably connected", or "operably coupled", to each other to
achieve the desired functionality, and any two components capable
of being so associated can also be viewed as being "operably
couplable", to each other to achieve the desired functionality.
Specific examples of operably couplable include but are not limited
to physically mateable and/or physically interacting components
and/or wirelessly interactable and/or wirelessly interacting
components and/or logically interacting and/or logically
interactable components.
[0131] While particular aspects of the present subject matter
described herein have been shown and described, it will be apparent
to those skilled in the art that, based upon the teachings herein,
changes and modifications may be made without departing from the
subject matter described herein and its broader aspects and,
therefore, the appended claims are to encompass within their scope
all such changes and modifications as are within the true spirit
and scope of this subject matter described herein. Furthermore, it
is to be understood that the invention is defined by the appended
claims. It will be understood by those within the art that, in
general, terms used herein, and especially in the appended claims
(e.g., bodies of the appended claims) are generally intended as
"open" terms (e.g., the term "including" should be interpreted as
"including but not limited to," the term "having" should be
interpreted as "having at least," the term "includes" should be
interpreted as "includes but is not limited to," etc.). It will be
further understood by those within the art that if a specific
number of an introduced claim recitation is intended, such an
intent will be explicitly recited in the claim, and in the absence
of such recitation no such intent is present. For example, as an
aid to understanding, the following appended claims may contain
usage of the introductory phrases "at least one" and "one or more"
to introduce claim recitations. However, the use of such phrases
should not be construed to imply that the introduction of a claim
recitation by the indefinite articles "a" or "an" limits any
particular claim containing such introduced claim recitation to
inventions containing only one such recitation, even when the same
claim includes the introductory phrases "one or more" or "at least
one" and indefinite articles such as "a" or "an" (e.g., "a" and/or
"an" should typically be interpreted to mean "at least one" or "one
or more"); the same holds true for the use of definite articles
used to introduce claim recitations. In addition, even if a
specific number of an introduced claim recitation is explicitly
recited, those skilled in the art will recognize that such
recitation should typically be interpreted to mean at least the
recited number (e.g., the bare recitation of "two recitations,"
without other modifiers, typically means at least two recitations,
or two or more recitations). Furthermore, in those instances where
a convention analogous to "at least one of A, B, and C, etc." is
used, in general such a construction is intended in the sense one
having skill in the art would understand the convention (e.g., "a
system having at least one of A, B, and C" would include but not be
limited to systems that have A alone, B alone, C alone, A and B
together, A and C together, B and C together, and/or A, B, and C
together, etc.). In those instances where a convention analogous to
"at least one of A, B, or C, etc." is used, in general such a
construction is intended in the sense one having skill in the art
would understand the convention (e.g., "a system having at least
one of A, B, or C" would include but not be limited to systems that
have A alone, B alone, C alone, A and B together, A and C together,
B and C together, and/or A, B, and C together, etc.).
[0132] While this specification contains many specific
implementation details, these should not be construed as
limitations on the scope of any invention or of what may be
claimed, but rather as descriptions of features that may be
specific to particular embodiments of particular inventions.
Certain features that are described in this specification in the
context of separate embodiments can also be implemented in
combination in a single embodiment.
[0133] Conversely, various features that are described in the
context of a single embodiment can also be implemented in multiple
embodiments separately or in any suitable subcombination. Moreover,
although features may be described above as acting in certain
combinations and even initially claimed as such, one or more
features from a claimed combination can in some cases be excised
from the combination, and the claimed combination may be directed
to a subcombination or variation of a subcombination.
[0134] Similarly, while operations are depicted in the drawings in
a particular order, this should not be understood as requiring that
such operations be performed in the particular order shown or in
sequential order, or that all illustrated operations be performed,
to achieve desirable results. In certain circumstances,
multitasking and parallel processing may be advantageous. Moreover,
the separation of various system components in the embodiments
described above should not be understood as requiring such
separation in all embodiments, and it should be understood that the
described program components and systems can generally be
integrated together in a single software product or packaged into
multiple software products.
RELATED ART
[0135] Erik Lofgren--"On the Non-Linear Distortion in the
Reproduction of Phonograph Records Caused by Angular Deviation of
the Pickup Needle" published November, 1938 [0136] H. G. Baerwald
"Analytic Treatment of Tracking Error and Notes on Optimal Pick-Up
Design" Published May 1, 1941 [0137] B. B. Bauer "Tracking Angle"
Electronics March 1945 [0138] Frank Schroder--U.S. Pat. No.
8,576,687 "COMPACT TANGENTIAL TRACKING TONEARM MECHANISM", field:
369/222, 369/255 issued November, 2013 [0139] F. Bruce
Thigpen--"RADIAL PHONOGRAPH PICKUP ARM AND TURNTABLE COMBINATION
USING AIR BEARINGS"--U.S. Pat. No. 4,628,500 field: 369/249, 255,
244, 245 issued May, 1985 [0140] Fumitaka Nagamura--"Tonearm
Linear-Drive Apparatus"--U.S. Pat. No. 3,940,149, field: 274/23
issued February, 1974 [0141] Francis Dennesen--"Stylus
Positioner"--U.S. Pat. No. 4,295,277--field 33/181 issued
September, 1979 [0142] Wilhelmus Vivie--"Phonograph Tonearm
Positioner" U.S. Pat. No. 2,601,987A--July, 1952
* * * * *