U.S. patent number 3,609,240 [Application Number 05/020,680] was granted by the patent office on 1971-09-28 for stereophonic headphones.
This patent grant is currently assigned to Industrial Patent Development Corp.. Invention is credited to Jon S. Fixler.
United States Patent |
3,609,240 |
Fixler |
September 28, 1971 |
STEREOPHONIC HEADPHONES
Abstract
Stereophonic headphones mount pairs of audio transducers
(speakers) on an opposing front to back axis relative to the head
of a listener to create a greater panorama of sound.
Inventors: |
Fixler; Jon S. (Philadelphia,
PA) |
Assignee: |
Industrial Patent Development
Corp. (Philadelphia, PA)
|
Family
ID: |
21799955 |
Appl.
No.: |
05/020,680 |
Filed: |
March 18, 1970 |
Current U.S.
Class: |
381/19; 381/370;
381/309 |
Current CPC
Class: |
H04R
1/1075 (20130101); H04R 1/1008 (20130101); H04R
2205/022 (20130101); H04R 5/033 (20130101) |
Current International
Class: |
H04R
1/10 (20060101); H04r 001/10 () |
Field of
Search: |
;179/1G,1GA,1E,182R,156
;181/23 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Claffy; Kathleen H.
Assistant Examiner: Olms; Douglas W.
Claims
I claim:
1. Stereophonic headphones for a four channel system comprising a
support for retaining first and second enclosures in position over
the ears of a listener, a first enclosure and a second enclosure,
each enclosure having an opening for the emission of sound into the
ear of a listener, each said opening being positioned in the
enclosure to face one of the ears of a listener, at least two audio
transducers in each enclosure for transducing electronic signals
into sound, said two audio transducers being mounted on a common
sound emitting axis, the axis defined by said transducers in each
enclosure being in a front-back direction relative to the head of a
listener when the enclosures are mounted over the ears of a
listener.
2. Stereophonic headphones for a four channel system in accordance
with claim 1 wherein said speakers are mounted in facing sound
emitting relation along said axis.
3. Stereophonic headphones for a four channel system in accordance
with claim 1 wherein said transducers are mounted to emit sound in
opposite directions along said axis.
4. Stereophonic headphones for a four channel system in accordance
with claim 1 wherein means are provided within said enclosure to
enhance the stereo separation of said audio transducers.
5. Stereophonic headphones for a four channel system in accordance
with claim 4 wherein said means for enhancing the stereo separation
is adjustable.
6. Stereophonic headphones for a four channel system in accordance
with claim 5 wherein said means is a cone-shaped, membrane.
7. Stereophonic headphones for a four channel system comprising at
least two pairs of audio transducers, one pair of audio transducers
in each headphone, each transducer in a pair being mounted in
sound-opposing relation, the axis defined by said opposing
transducers in each pair being in a front to back direction
relative to the head of a listener when the headphones are mounted
over the ear of a listener.
Description
This invention relates to stereophonic headphones. More
particularly, this invention relates to stereophonic headphones
with audio transducers mounted so as to create the effect of a
greater panorama of sound.
Stereophonic headphones have been in use for a number of years.
Moreover, they have been developed to a high degree of
sophistication and are capable of rather faithfully transducing
electronic signals into sound. However, all stereophonic headphones
suffer from one rather annoying characteristic. That is, the
listener perceives the sound as emanating from the center of his
head. Thus, while stereophonic headphones do produce differential
left-right characteristics, they do not produce a true panorama of
sound. It is the purpose of the present invention to provide
stereophonic headphones capable of producing the effect of a true
panorama of sound.
In accordance with the present invention each of the headphones is
provided with at least one pair of audio transducers. These
transducers are mounted on an opposing front to back axis within
the headphones. The axis itself extends in a front to back
relationship with respect to the listener's head. The sound
emitting opening adjacent the listener's ear is positioned
laterally of this axis. It has been found that this particular
positioning of a pair of audio transducers within each headphone
produces the effect of a true panorama of sound for the listener to
perceive.
It therefore is an object of the present invention to provide a new
and improved stereophonic headphone wherein the listener perceives
the effect of panoramic sound.
Other objects will appear hereinafter.
For the purpose of illustrating the invention, there are shown in
the drawings forms which are presently preferred; it being
understood, however, that this invention is not limited to the
precise arrangements and instrumentalities shown.
FIG. 1 is a front view of the headphones constructed in accordance
with the present invention.
FIG. 2 is a partial transverse and partial top plan view of the
headphones illustrated in FIG. 1 taken along the line 2--2.
FIG. 3 is a transverse sectional view of the headphones illustrated
in FIG. 1 taken along the line 3--3.
FIG. 4 is a partial transverse view of a headphone illustrating
another embodiment of the present invention.
Referring now to the drawings in detail, wherein like numerals
indicate like elements, there is shown in FIG. 1 a pair of
stereophonic headphones designated generally as 10.
As shown, the headphones 10 include a first headphone 12 and a
second headphone 14 pivotally mounted on a resilient support
bracket 16. The bracket 16 may be made of any conventional
resilient material and is preferably provided with a closed conduit
18 through which interconnection conductors can be threaded. The
bracket 16 is appropriately connected to the housings 20 and 22 for
the headphones 12 and 14 by the pins 24 and 26. Of course, other
well-known means for connecting headphones to a supporting bracket
may be used.
The housings 20 and 22 are preferably made of a tough, molded
plastic which completely surrounds and encloses the audio
transducers described below. As best shown in FIG. 3, each of the
housings 20 and 22 is provided with an opening 28 or 30 in which is
positioned a perforated disc 32 or 34, respectively. The purpose of
the openings 28, 30 and discs 32, 34 is to provide for the emission
of sound directly into the listerner's ears. Thus, the openings 28,
30 are provided on inward faces 36 and 38 of the housings 20 and 22
and directly overlie the listener's ears when the headphones 10 are
placed on his head. The discs 32 and 34 may be made of any
conventional material used for this purpose in the headphones.
Mounted within each headphone 12 and 14 is a pair of audio
transducers. Thus, the audio transducers 40 and 42 are mounted
within the headphone 12 and the audio transducers 44 and 46 are
mounted within the headphone 14. Each audio transducer may take the
form of a 1 inch or 11/2 inch speaker. Such speakers are available
on the market and hence need not be described in detail. Of course,
better quality speakers are preferable to obtain a more faithful
audio reproduction of the electronic signal. Each transducer is
mounted within its respective housing 20 or 22 by fixing it to a
plastic foam backing. Thus, transducer 40 is fixed to the plastic
foam backing 48 which fills the entire area behind the transducer.
In a like manner, the transducer 44 is fixed to a foam backing 52
and the transducer 46 is fixed to a foam backing 54. The
transducers 40-46 may be fixed to the foam backings 48-54 in any
conventional manner such as by use of an adhesive fixative or by a
heating sealing process.
As best shown in FIG. 2, audio transducer 40 is directly opposite
and faces transducer 42. In a like manner, transducer 44 is
directly opposite and faces transducer 46. Thus, each headphone 12
and 14 contains a pair of transducers mounted in opposing relation.
Moreover, the transducers are on a common axis defined by an
imaginary line drawn through their geometric centers. This axis
extends in a direction which may be described as front to rear with
relation to the head of a listener when the headphones 12 and 14
are each mounted over an ear with the bracket 16 extending across
the top of the head. The sound emission openings 28 and 30 are
laterally positioned with respect to the aforesaid imaginary axis.
The pair of transducers 40 and 42, as shown, are spaced from each
other across the diameter of the opening 28. In a like manner, the
transducers 44 and 46 are spaced from each other across the opening
30.
As thus positioned within the housings 20 and 22, the transducers
40-42 and 44-46 generate a sound pattern which is a full panorama
effect to the listener. In other words, the sound seems to the
listener to be directed at him along a continuum extending fully
front his left side to his right side.
To further increase the stereo separation between the paired
speakers within each enclosure 20, an expandable membrane 60 is
fixed to the wall opposite to the opening 28. Membrane 60 is
preferably made of a sound reflective material such as elastomeric
product coated with plastic. However, any type of stretchable
material is suitable. The membrane 60 is preferably dish-shaped and
its edges are fixed to the aforesaid wall by any suitable means
such as by cementing.
A threaded opening 64 is provided in the wall of enclosure 20. An
elongated adjusting member such as the threaded screw 62, having a
knurled head thereon, is threaded through the opening 64. The
distal end of the member 62 engages the membrane 60 in the center
thereof. By adjusting the position of screw 62 within opening 64,
the stretchable membrane is caused to take on the shape of a cone
and extend a greater or lesser distance into the space between the
speakers 40 and 42. This is shown by the dotted lines in FIG. 2. A
similar membrane 60 is mounted within the enclosure 22.
The purpose of the membrane is to increase the stereo separation
between the speakers 40 and 42. In a like manner, the membrane
mounted within enclosure 22 increases the stereo separation between
the speakers 44 and 46.
In operation, each transducer is connected to one track of a four
track stereophonic system. Such a system may include a four track
tape or some other means for generating four distinct electronic
signals, each being representative of a particular microphone
position recording sound generated over a measurable distance;
e.g., an orchestra or a band. As thus positioned within the
headphones 10, the transducers generate an effect perceived by the
listener as a full panorama of sound emanating toward him in all
direction. It is not entirely understood why this positioning of
the transducers produces a panorama of sound. It should be
sufficient to state that other positions of the transducers
relative to the ear of the listener does not produce the panorama
effect. Rather, the listener perceives the sound as emanating from
the center of his head.
Referring now to FIG. 4, there is shown still another embodiment of
the present invention. Only one earphone is shown since, as
illustrated in FIGS. 1, 2 and 3, the concepts of the invention are
duplicated in each earphone of the complete set. As shown, an
enclosure 70 has an opening 72 on which is mounted a conventional
earpiece 74 for fitting over the listener's ear. The enclosure 70
is preferably made of plastic or some other material conventionally
used for enclosing headphones.
Mounted within the enclosure 70 are a pair of audio transducers
which take the form of speakers 76 and 78. The speaker 76 is
provided with a conventional driving coil and magnet 80. In a like,
the speaker 78 is provided with a driving coil and magnet 82. Of
course, other forms of audio transducers may be provided, if
desired. The audio transducers 76 and 78 are mounted in axial
alignment within the enclosure 70. They differ from the alignment
illustrated in FIG. 2 in that each speaker is turned 180.degree. so
that they face in opposite directions. The axis of the alignment of
the transducers 76 and 78, however, is spaced laterally from the
opening 72 in the same manner as the axis of the paired speakers
illustrated in FIG. 2. Moreover, the aforesaid axis is aligned so
as to extend from front to back relative to a listener's head when
mounted thereon.
A wall 84, preferably made of sound-insulating foam, extends
between the transducers 76 and 78 and is positioned intermediate
the opening 72. Thus, the wall 84 substantially isolates the sound
emanating from the audio transducers 76 and 78. The speakers 76 and
78 are mounted to the wall 84 by any conventional means.
A pair of stretchable membranes 86 and 88 are each formed in the
shape of a cone and extend outwardly from the edges of the wall 84
to the speaker electromagnets 80 and 82. The membranes 86 and 88
are preferably made of an elastomeric material such as rubber.
Moreover, they may be coated with a plastic or other material, as
desired. The purpose of the membranes 86 and 88 is to enhance the
stereo separation emanating from the speakers 76 and 78.
The present invention may be embodied in other specific forms
without departing from the spirit or essential attributes thereof
and, accordingly, reference should be made to the appended claims,
rather than to the foregoing specification as indicating the scope
of the invention.
* * * * *