U.S. patent application number 09/875948 was filed with the patent office on 2001-10-11 for method for recording information on a memory.
This patent application is currently assigned to Pioneer Electronic Corporation. Invention is credited to Ishihara, Hiroyuki.
Application Number | 20010029559 09/875948 |
Document ID | / |
Family ID | 14605847 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010029559 |
Kind Code |
A1 |
Ishihara, Hiroyuki |
October 11, 2001 |
Method for recording information on a memory
Abstract
A reference value is set for recording quantity of information,
and a plurality of compression factors is provided for compressing
information to be recorded. The compression factors are arranged in
order. The information is sequentially recorded on a first memory
at a first compression factor of the arrangement of the compression
factors. It is determined whether the recording quantity of a first
information group reaches the reference value. The first
information group is compressed at a larger second compression
factor when the recording quantities reaches the reference value,
and the compressed first information group is recorded on the first
memory at a first area. A second information group following the
first information group is compressed at the second compression
factor, and the compressed second information group is recorded on
the first memory at a second area next to the first area. It is
determined whether the sum of the recorded first and second
information groups reaches the reference value. The recorded first
and second information group are compressed at a further larger
third compression factor. The compression of the information groups
at succeeding compression factors and recording of the compressed
information groups are repeated until end of the information to be
recorded.
Inventors: |
Ishihara, Hiroyuki;
(Saitama-ken, JP) |
Correspondence
Address: |
ARENT FOX KINTNER PLOTKIN & KAHN
1050 CONNECTICUT AVENUE, N.W.
SUITE 600
WASHINGTON
DC
20036
US
|
Assignee: |
Pioneer Electronic
Corporation
|
Family ID: |
14605847 |
Appl. No.: |
09/875948 |
Filed: |
June 8, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09875948 |
Jun 8, 2001 |
|
|
|
09069795 |
Apr 30, 1998 |
|
|
|
6272568 |
|
|
|
|
Current U.S.
Class: |
710/68 |
Current CPC
Class: |
H03M 7/30 20130101 |
Class at
Publication: |
710/68 |
International
Class: |
G06F 013/12; G06F
013/38 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 1997 |
JP |
9-113190 |
Claims
What is claimed is:
1. A method for recording information on a memory comprising the
steps of: setting a reference value for recording quantity of
information; providing a plurality of compression factors for
compressing information to be recorded; sequentially recording the
information on a memory at a first compression factor; determining
whether a recorded quantity reaches the reference value;
compressing following data at a second compression factor when the
recorded quantity reaches the reference value; recording th
information compressed at the second compression factor on the
memory; repeating the compression of the information at succeeding
compression factors and recording of the compressed information
until end of the information to be recorded.
2. A method for recording information on a memory comprising the
steps of: setting a reference value for recording quantity of
information; providing a plurality of compression factors for
compressing information to be recorded; sequentially recording the
information on a first area of a first memory at a first
compression factor; determining whether a recorded quantity of a
first information group reaches the reference value; compressing a
second information group following the first information group at a
second compression factor when the recorded quantity of the first
information group reaches the reference value; recording the
compressed second information group on the first memory on a second
area; determining whether the recorded quantity of the second
information group recorded in the second area reaches the reference
value; compressing a third information group at a third compression
factor when the recorded quantity reaches the reference value;
repeating the compression of the information groups at succeeding
compression factors and recording of the compressed information
groups until end of the information to be recorded.
3. The method according to claim 2 further comprising compressing
the first information group at the second compression factor when
the recorded quantity thereof reaches the reference value in
parallel with the step of compressing of the second information
group, determining whether the sum of the recorded first and second
information groups reaches the reference value, compressing the
recorded first and second information groups at the third
compression factor.
4. The method according to claim 2 wherein the compressed
information groups are finally recorded in a desired second
memory.
5. The method according to claim 2 wherein the first memory is a
desired second memory.
6. The method according to claim 2 wherein the compression factor
is increased at every change of the compression factor.
7. The method according to claim 2 wherein the order of the
compression factor is decreased at every change of the compression
factor.
8. The method according to claim 2 wherein the reference value is
set in accordance with the capacity of the first memory.
9. A method for recording information on a memory comprising the
steps of: setting a plurality of reference values for recording
quantity of information; providing a plurality of compression
factors for compressing information to be recorded; sequentially
recording the information on a memory at a first compression
factor; determining whether a recorded quantity reaches the
reference value; compressing following data at a second compression
factor when the recorded quantity reaches the reference value;
recording the information compressed at the second compression
factor on the memory; repeating the compression of the information
at succeeding compression factors and recording of the compressed
information until end of the information to be recorded.
10. The method according to claim 9 wherein the reference values
are arranged in an increasing order in quantity.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for recording
information on a memory such as a so-called PC card provided with a
semiconductor memory.
[0002] A tape recorder which uses such principle that information
causes variation in magnetization has been widely used for
recording audio information. Recently, there has been known and
actually used another recording system using a memory card. The
memory card, which is often referred to as a PC card, is provided
with a semiconductor memory and has a size about a calling
card.
[0003] The PC card comprises integrated elements such as the
semiconductor memory, transistors, capacitors, and resistors. The
semiconductor memories can be roughly categorized into a bipolar
memory and a MOS memory. The bipolar memory is more advantageous
than the MOS memory in that it requires less access time. However,
larger power is consumed, and in addition, causes a larger heat
radiation. To the contrary, the MOS memory requires a longer access
time, but involves less power consumption and heat radiation. The
semiconductor memory with a large capacity is usually a MOS
memory.
[0004] Referring to FIG. 7, a conventional recording and
reproducing system for the PC card comprises a CPU 1, audio
interface 2, key interface 3, display interface 4, and a memory
card interface 5. The audio interface 2 is applied with digital
audio information through a DIR 7, and analog audio information
through an A/D converter 8. The digital information is transmitted
from the recording and reproducing system through a D/A converter
9. The key interface 3 is connected with a key matrix 10 for the
user to input various information, and the display interface 4 is
connected to a liquid crystal display 11 on which various
information is shown. A PC card 12 is detachably connected to the
memory card interface 5 so that the desired information is recorded
on the card and read out therefrom. The information may further be
erased from the PC card 12. The CPU 1 and the interfaces 2 to 5 are
connected to each other through a system bus 6, and the interfaces
2 to 5 are connected to respective peripheral equipments 7 to 12
through the system buses 6.
[0005] The recording and reproducing system is further provided
with a ROM 13 and a RAM 14. The ROM 13 stores a program for
controlling the operation of the entire system. When the power of
the system is turned on, the program in the ROM 13 is stored in the
RAM 14 which is a main memory, thereby starting a predetermined
operation. Namely, the interfaces 2 to 5 are initialized and the
operations thereof checked. Hence the system is ready for operation
which is started by operating the key matrix 10.
[0006] In operation, when a predetermined switch is turned on, the
CPU 1 executes the program stored in the ROM 13. Information
applied through the audio interface 2 is temporarily stored in the
RAM 14, or in a separately provided buffer RAM, and thereafter,
recorded on the PC card 12. The recorded information can be
reproduced when a command signal is applied from the CPU 1. Various
information is indicated on the display 11 during the
operation.
[0007] In order to record a large quantity of information on the PC
card 12, information may be compressed as necessary. The compressed
information is directly recorded on the PC card 12. Alternatively,
the uncompressed information corresponding to one block is stored
in the RAM 14 or the buffer RAM, and thereafter, the block of
information is compressed and written on the PC card 12. In the
latter method, the compression and the recording are repeated until
the necessary information are written on the PC card 12.
[0008] A compression factor at the compression is calculated as
follows. When the sampling frequency when the information is not
compressed is 48 kHz, which is the same as in the case of recording
a digital audio tape (DAT), and one word corresponds to 16 bits,
one channel bit rate (br) is 768 kbps/ch. Since
br=fs*w,
br=48 (kHz)*16 (bit)=768 kbps/ch
[0009] The equation applies to a case of a recording with one
channel so that at a stereophonic recording, the value is doubled.
Hence the compression factor is calculated in accordance with,
br=fs*w=M/2t
[0010] wherein M is the storage capacity of the PC card 12, and t
is the recording time. The numeral 2 in the denominator indicates
that the compression factor is applied to a stereophonic
recording.
[0011] For example, when the PC card 12 has a storage capacity of
40 MB (10M word/stereophonic recording), the time capable of
recording on the PC card at each compression factors is as follows.
When the information is not compressed, the recording time is 208
sec/stereophonic recording. When the compression factor is 1/2, the
recording time is 416 sec/stereophonic recording, when the
compression factor is 1/3, 624 sec/stereophonic recording, and when
1/6, 1248 sec/stereophonic recording. The compression is carried
out in accordance with various conventional methods which have been
developed and used, so that the detailed descriptions thereof are
omitted.
[0012] In such a recording and reproducing system, when the
quantity of the information to be recorded, that is the length of
recording time, is known beforehand, the user can select a PC card
having a sufficient storage capacity, or determine an appropriate
compression factor dependent on the storage capacity of the PC
card. Hence, the information can be recorded from the beginning to
the end without fail. However, when the length of the information
is unknown, such as when recording every statement made during a
conference, there may be cases where the conventional system cannot
record the conference to the end. The entire conference can be
recorded if a system using a large compression factor is employed.
However, when the information is recorded at a large compression
factor, the deterioration in sound quality inevitably occurs.
Although the recording of a conference does not require a superior
sound quality, the large compression factor may cause error at
reproduction. Thus, it is preferable to maintain the compression
factor as small as possible.
[0013] In addition, there may be a case where the recording time is
unexpectedly short so that the PC card still has a large storage
capacity left when the recording is over. Since the user do not
think of using the same PC card when recording another information,
the remaining storage capacity is wasted.
[0014] Namely, although there still may be a storage capacity left
in the PC card, the user do not usually use the card when recording
information of indefinite length. The user will use a new PC card
instead. Hence in a system where the compression factor can be set
at various levels, when the information is recorded at the largest
compression factor, the length of the recording information may be
unexpectedly short so that the storage capacity of the PC is
wasted, which is recording information may be unexpectedly short so
that the storage capacity of the PC is wasted, which is
undesirable. In order to prevent such a waste, the information on
the PC card is re-recorded on another PC card so as to enable the
information on the original PC card to be erased, or another
information to be written over the old. Such an operation is
troublesome.
SUMMARY OF THE INVENTION
[0015] An object of the present invention is to provide a method
and a system for recording information on a PC card where the
storage capacity thereof is effectively utilized, and the
information of indefinite length is recorded to the end without
fail.
[0016] According to the present invention, there is provided a
method for recording information on a memory comprising the steps
of, setting a reference value for recording quantity of
information, providing a plurality of compression factors for
compressing information to be recorded, sequentially recording the
information on a first area of a first memory at a first
compression factor, determining whether a recorded quantity of a
first information group reaches the reference value, compressing a
second information group following the first information group at a
second compression factor when the recorded quantity of the first
information group reaches the reference value, recording the
compressed second information group on the first memory on a second
area, determining whether the recorded quantity of the second
information group recorded in the second area reaches the reference
value, compressing a third information group at a third compression
factor when the recorded quantity reaches the reference value,
repeating the compression of the information groups at succeeding
compression factors and recording of the compressed information
groups until end of the information to be recorded.
[0017] The compressed information groups are finally recorded in a
desired second memory.
[0018] The first memory is a desired second memory.
[0019] The compression factor is increased at every change of the
compression factor.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIGS. 1 to 3 are flowcharts describing the operations of
various embodiments of a system for recording information on a PC
card according to the present invention;
[0021] FIG. 4 is an illustration explaining reference values of
quantity of information recorded on the PC card in the embodiment
described in FIG. 3;
[0022] FIG. 5 is a flowchart describing the operation of another
embodiment of the recording system;
[0023] FIG. 6 is an illustration explaining reference values of
quantity of information recorded on the PC card in the embodiment
described in FIG. 5; and
[0024] FIG. 7 is a block diagram showing a conventional recording
and reproducing system for the PC card.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] The recording system for recording information on a PC card
to which the present invention is applied, has the same basic
construction as the system shown in FIG. 7. Namely, the system for
the PC card comprises the CPU 1, audio interface 2, key interface
3, display interface 4, and the memory card interface 5. The audio
interface 2 is applied with digital audio information through the
DIR 7, and analog audio information through the A/D converter 8.
The digital information is transmitted from the recording and
reproducing system through the D/A converter 9. The key interface 3
is connected with the key matrix 10 for the user to input various
information, and the display interface 4 is connected to the liquid
crystal display 11 on which various information is shown. The PC
card 12 is detachably connected to the memory card interface 5 so
that the desired information is recorded on the card and read out
therefrom. The information may further be erased from the PC card
12. The CPU 1 and the interfaces 2 to 5 are connected to each other
through the system bus 6, and the interfaces 2 to 5 are connected
to respective peripheral equipments 7 to 12 through the system
buses 6.
[0026] The recording and reproducing system is further provided
with the ROM 13 and the RAM 14. The ROM 13 stores a program for
controlling the operation of the entire system. When the power of
the system is turned on, the program in the ROM 13 is stored in the
RAM 14 which is a main memory, thereby starting a predetermined
operation. Namely, the interfaces 2 to 5 are initialized and the
operations thereof checked. Hence the system is ready for operation
which is started by operating the key matrix 10.
[0027] In operation, when a predetermined switch is turned on, the
CPU 1 executes the program stored in the ROM 13. Information
applied through the audio interface 2 is temporarily stored in the
RAM 14, or in a separately provided buffer RAM, and thereafter,
recorded on the PC card 12. The recorded information can be
reproduced when a command signal is applied from the CPU 1. Various
information is indicated on the display 11 during the
operation.
[0028] The operation of the first embodiment of the present
invention will be described hereinafter with reference to FIG. 1.
In the system of the first embodiment, a buffer RAM is provided in
addition to the devices shown in FIG. 7. The storage capacity of
the buffer RAM is the same as, or larger than that of the PC card
12. A predetermined reference value, which corresponds to the
storage capacity of the PC card 12, is set in the buffer RAM.
[0029] With the turning on of a predetermined switch, the
initialization is carried out at a step S1, where the program
stored in the ROM 13 is executed by the CPU 1. The program of the
present embodiment is adapted to execute compression of information
at six levels. Namely, the compression factor can be chosen from 1,
that is when information is not compressed, 1/2, 1/3, 1/4,
{fraction (1/6)}, and {fraction (1/12)}.
[0030] The PC card 12 is loaded through an opening (not shown) of
the system. The system detects whether the PC card 12 is loaded,
and indicates the result on the display 11.
[0031] When the PC card 12 is correctly loaded, the program goes to
a step S2 where the storage capacity of the PC card 12 is detected
and stored in the RAM 14. If the PC card 12 already has information
written on it, the remaining capacity is detected. In such a case,
the new information is recorded following the already recorded
information. However, with the operation of the key matrix 10, the
new information can be written over the recorded information. The
storage capacity of the PC card 12 in consideration to the
operation of the keys is shown on the display 11. For the
convenience of the user, the display 11 may further show the
possible recording time when each of the six compression rates is
selected. The recording time can be input by operating the key
matrix 10 if it is known to the user.
[0032] At a step S3, the information to be recorded is applied
through a microphone or through an input terminal and written in
the buffer RAM. At this time, the compression of information is not
executed. Thereafter, at a step S4, the CPU 1 determines whether
the quantity of the recorded information reaches the reference
value, which is the capacity corresponding to one block of the
buffer RAM. When the recorded quantity is smaller than the
reference value, the program returns to the step S2 to continue to
temporarily store the information in the buffer RAM.
[0033] If the quantity of the recorded information reaches the
reference value, the program goes from the step S4 to a step S5
where the operation of the key matrix 10 for ending the recording
is detected. When the recording is to be ended, the program jumps
to a step S16 where the information stored in the buffer RAM is
recorded on the PC card 12 without compressing. Thereafter, the
program is ended at a step S17.
[0034] When the matrix key 10 is not operated at the step S5 so
that the recording is to be continued, the program proceeds to a
step S6 where the compression factor is raised one level. Namely,
in the first routine, since the compression is not carried out, the
compression factor is now set at the first compression factor of
1/2. At a step S7, the information stored in the buffer RAM is read
out, at a step S8, the read out information is compressed, and at a
step S9, the compressed information is again stored in the buffer
RAM. At a step S10, it is determined whether the compression at the
determined compression factor is completed. If the compression is
completed, the program goes to a step S14, and if not, the steps S7
through S9 are repeated.
[0035] During the operation of the steps S7 to S10, another
operation of steps S11 through S13 is carried out. Namely, at the
step S11, the information to be recorded continues to be applied
through the microphone or the input terminal as at the step S2. At
the step S12, the applied information is compressed at the
compression factor determined at the step S6, and stored in the
buffer RAM at the step S13.
[0036] At the step S14, it is determined whether the sum of the
quantities of the compressed information recorded at the steps S9
and S13 reaches the reference value. If the recorded quantity does
not yet reach the reference value, the program returns to the step
S11 to continue the recording.
[0037] If the recorded quantity reaches the reference value, it is
determined whether the key matrix 10 is operated to end the
recording at a step S15. When the recording is to be ended, the
program goes to the step S16. On the other hand, when the recording
is to be continued, the program goes to a step S18 to determine
whether the compression factor set at the step S6 is the maximum
factor of {fraction (1/12)}, that is whether the compression is
carried out at the maximum compression factor at the steps S8 and
S12. If the present compression factor is not the maximum factor,
the program goes back to the step S6. More particularly, in the
first routine, since the compression factor is the first factor of
1/2, the program returns from the step S18 to the step S6 where the
second compression factor, 1/3, is determined. The steps S6 to S18
are repeated until the recording is completed, or the maximum
compression factor is selected.
[0038] When it is determined at the step S18 that the compression
is carried out at the maximum compression factor, it means there is
an error, or the PC card 12 is full. Accordingly, an error sign or
an instruction to exchange the PC card 12 for another is shown on
the display 11 at a step S19. Thereafter, the program is ended at a
step S20 in the case of error, or returns to the step S1 when the
PC card 12 is changed.
[0039] Thus in accordance with the present invention, the
compression factor is gradually changed depending on the length of
the information to be recorded. Thus the PC card is effectively
utilized without wasting the remaining storage capacity, and the
information can be recorded to the end. The present invention may
be applied both to the MOS memory and the bipolar memory.
[0040] The present embodiment may be so modified that the
compression factor is initially set at the maximum factor of
{fraction (1/12)}. Hence at the step S6, the compression factor is
gradually decreased. At the step S18, it is determined whether the
minimum compression factor is set, and when the compression factor
is larger than the minimum factor, the compression factor is
decreased one level at a time in the following routines. However,
the modification is inferior than the first embodiment in that,
since the maximum compression factor is initially determined, the
quality of the signal at reproduction is inevitably
deteriorated.
[0041] The recording system of the second embodiment of the present
invention, the operation of which is described in FIG. 2, is not
provided with the buffer RAM. Hence the information is directly
recorded on the PC card 12.
[0042] Referring to FIG. 2, after the system is initialized at the
step S1, and the storage capacity of the PC card 12 is detected at
the step S2, the recording of the information on the PC card 12 is
carried out at a step S3a. The quantity of the recorded information
is compared at a step S4a with a predetermined reference value,
which is an arbitrary value smaller than the storage capacity of
the PC card 12. When the quantity of the recorded information
reaches the reference value, the information already recorded on
the PC card is read out at a step S7a, compressed at the step S8 at
the compression factor determined at the step S6, and rerecorded on
the card at a step S9a.
[0043] At the same time, the information applied at the step S11,
is compressed at the step S12 and recorded on the PC card 12 at a
step S13a.
[0044] The compression factor is increased every time the quantity
of information recorded on the PC card 12 reaches the reference
value at a step S14a. When the quantity of information compressed
at the maximum compression factor and recorded on the PC card 12
reaches the reference value, the error sign or the instruction to
change the PC card 12 is indicated on the display 12. Other
operations are the same as those of the first embodiment.
[0045] The second embodiment may also be modified in the same
manner as the first embodiment as described above so that the
compression factor is gradually decreased.
[0046] In the third embodiment described in FIG. 3, four reference
values of the recording quantity are predetermined as shown in FIG.
4.
[0047] Namely, when it is determined at the steps S4a and S5 that
the quantity of the recorded information reaches the initially set
first reference value, and the recording is to be continued, the
reference value is changed from the first value to the larger
second value at a step S21. Thereafter, at the step S6, the
compression factor is also set to the first compression factor of
1/2.
[0048] The information which is applied thereafter at the step S11
is compressed at the increased compression factor at the step S12
and recorded on the PC card at the step S13a. When the quantity of
the recorded information reaches the second reference value at the
step S14a, the program returns to the step S6 where the second
compression factor 1/3 is set. The operation is repeated until the
compression at the maximum compression factor is carried out.
[0049] The third embodiment may be further modified to gradually
decrease the compression factor and the reference value.
[0050] The fourth embodiment is similar to the third embodiment
expect that the recording system is provided with the buffer RAM as
in the first embodiment. Hence the information temporarily stored
in the buffer RAM is recorded on the PC card 12 without compression
at the step S16 when the recording is to be ended. The information
is further recorded on the PC card 12 at a step S22 before
increasing the compression factor.
[0051] The first to fourth reference values in the fourth
embodiment are predetermined as shown in FIG. 6.
[0052] The fourth embodiment may also be modified to decrease the
reference value and the compression factor.
[0053] The present invention may be applied not only when recording
audio information but also when recording visual signals. The
recording system may be a standalone recording device, or may be
attached to other audio devices.
[0054] From the foregoing it will be understood that the present
invention provides a method and a system for recording information
on the PC card wherein the compression factor is changed dependent
on the length of the information so that the storage capacity of
the PC card is effectively utilized and the information is recorded
to the end. Hence such inconveniences as the wasting of the
remaining capacity of the PC card are prevented while recording the
entire desired information.
[0055] While the invention has been described in conjunction with
preferred specific embodiment thereof, it will be understood that
this description is intended to illustrate and not limit the scope
of the invention, which is defined by the following claims.
* * * * *