United States Patent
`Okanoet al.
`
`5:5
`
`[54] VOICE START RECORDING APPARATUS
`
`[75]
`
`Inventors: Hideo Okano, Hannou; Yuichi Saito,
`Sagamihara; Masatoshi Tobinai,
`Hachioji, all of Japan
`
`[73] Assignee: Olympus Optical Co., Ltd., Tokyo,
`Japan
`
`[21] Appl. No.: 08/690,158
`
`[22]
`
`Filed:
`
`Jul. 19, 1996
`
`[30]
`
`Foreign Application Priority Data
`
`Jul. 19, 1995
`[JP]
`Japan. cecssssssssssssescecccsseesessseees 7-183073
`
`Aug. 3, 1995
`[JP]
`« 7-198741
`Japan ....
`Aug. 81995
`[JP]
`Japan vecsccccseeseseeesseseseesaes 7-201933
`[ST] Wnt? ssasstsseissasciscccascaancancien HO4R 29/00
`[52> SH Onennsenismacenmcmenn 381/56; 381/110
`[58]
`Field of Search .................. 381/56, 110; 704/210,
`704/215, 233, 231; 379/88.01
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`3,873,772
`4,006,309
`AS42525
`
`3/1975 Dumler .
`2/1977 Brickerd, Jr. .
` OOSS: Hoph scccciiaiiisintis cae 381/110
`
`US006031915A
`{11} Patent Number:
`[45] Date of Patent:
`
`6,031,915
`Feb. 29, 2000
`
`1/1990 Howells et al. .
`4,893,197
`5/1990 Nakano oe 381/110
`4,926,484
`11/1993 Peters et al. oe SBL/1L0
`5,259,035
`3/1994 Glick .
`5,293,273
`8/1994 Pastor.......
`5,337,251
`wee 381/56
`
`1/1996 Sélve et al.
`5,485,522
`we 381/56
`5,563,952 LO/L996 Mercer wocccccccccceeesteesteeeteeeeeeee 381/56
`1/1997 Graumann...
`we 381/56
`5,598,466
`5,619,554
`4/1997 Hoganet ab. wees 379/76
`
`FOREIGN PATENT DOCUMENTS
`
`3149134A1
`63-259700
`
`11/1981 Germany.
`10/1988
`Japan .
`
`Primary Examiner—Vivian Chang
`Attorney, Agent, or Firm—Louis Weinstein
`
`[57]
`
`ABSTRACT
`
`A voice start recording apparatus includes a voice level
`determining circuit for determining whether consecutive
`frames of input voice is soundor silent, each frame being a
`coded voice signal;
`a continuity monitoring circuit
`for
`monitoring continuity of sound framesor silent frames; and
`a recording control circuit for controlling the start and stop
`of a recording operation based on the output from the
`continuity monitoring circuit.
`
`12 Claims, 14 Drawing Sheets
`
`
`
`SYSTEM
`
`
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`
`
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`17
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`1
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`GOOGLE 1006
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`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 1 of 14
`
`6,031,915
`
`9da-9d
`
`
`
`
`
`TWNODISTVLIDIO
`
`Cc
`
`WALSAS
`
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`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 2 of 14
`
`6,031,915
`
`
`
`FILE
`
`INDEX
`PORTION
`10A
`
`VOICE
`DATA
`PORTION
`10B
`
`FIG.2
`
`MEMORY
`
`START ADDRESS
`VOICE FILE DATA
`
`Sl
`N m ° Ti
`VOICE FILE DATA
`
`ERASE FLAG OF FILE
`
`RECORDING FILE
`NUMBER
`
`VOICE CODING SCHEME
`IDENTIFY SIGNAL
`
`FLAG REPRESENTING
`FILE STATE
`
`MAXIMUM VALUE NUMBERn OF
`INSERTABLE FILE
`
`LENGTH TO
`INSERTED VOICE FILE
`
`START POSITION ADDRESS OF
`FIRST EDITION
`
`FILE DATA START ADDRESS
`POSITION OF FIRSTEDITION
`FILE SIZE OF
`FIRST EDITION
`
`START POSITION ADDRESS OF
`nTH EDITION
`
`FILE DATA START ADDRESS
`
`POSITION OF nTH EDITION
`
`FILE SIZE OF
`nTH EDITION
`
`1 FRAME DATA
`
`2 FRAME DATA
`
`3 FRAME DATA
`
`10A1
`
`10A2
`
`10A3
`
`10A4
`
`10A5
`
`10A6
`
`10A7
`
`10A8
`
`10A9
`
`10A10
`
`10A11
`
`10A12
`
`10A13
`
`10A14
`
`10B1
`
`10B2
`
`10B3
`
`“
`
`m FRAME DATA
`
`INDEX PORTION OF
`FIRST EDITION (INSERTION)
`VOICE DATA PORTION OF
`FIRST EDITION (INSERTION)
`
`70Bm
`
`ea
`
`10C
`
`10D
`
`
`
`
`
`CODING
`INITIALIZING
`SIGNAL
`10B1
`
`SIGNAL
`REPRESENTING
`SOUND/
`SILENCE
`OF 10B1
`
`3
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 3 of 14
`
`6,031,915
`
`FIG.3
`
`St
`
`$2
`
`POWER
`SUPPLY VOLTAGE
`OK?
`
`Is
`
`?
`
`NO
`
`IS
`
`FORMAT OF
`SEMICONDUCTOR
`
`MEMORY SECTION
`
`NORMAL
`
`
`?
`
`DISPLAY INITIAL
`SETTING COMPLETION
`
`PERFORM MEMORY
`FORMAT
`
`DETECT OPERATION
`POSITION
`
`S10
`
`
`
`ERROR
`DISPLAY
`
`$12
`
`
`
`
`$23
`vee
`S3
`
`
`
`DATA TRANSFERPERFORMED
`|
`
`DATA TRANSFER |PROCESS
`
`
`
`
`
`S11
`
`
`
`HAS
`BEEN BUTTON
`
`
`PRESSED
`
`RECORDING
`PROCESS
`
`
`
`
`[RECORDINGPROCESS|
`S14
`REPRODUCING
`
`BUTTON?
`
`REPRODUCING PROCESS||
`
`
`FAST FEEDING PROCESS
`
`
`
`
`
`
`MAIN POWER
`
`YES
`SUPPLYanton
`NO
`
`S21
`
`TRANSFER INDEX
`INFORMATION IN
`SYSTEM CONTROLLER
`TO SEMICONDUCTOR
`MEMORY SECTION
`
`S22
`
`TURN POWER
`| SUPPLY SWITCH OFF
`
`AST
`REWINDING
`BUTTON?
`
`S20
`
`FAST REWINDING
`PROCESS
`
`4
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 4 of 14
`
`6,031,915
`
`"reSee
`
`PRO
`
`DETECTION OF OPERATION
`CONDITION OF RECORDING MODE
`
`TRANSMIT RECORDING MODE SIGNAL
`
`
`
`S31
`
`S32
`
`$33
`S34
`
`S35
`
`S36
`
`SET MEMORY MANAGEMENTINFORMATION
`
`
`
`
`INITIALIZE SILENT ee COUNT VALUE
`n=
`
`
` INITIALIZE osTcH FORMATION VALUE
`
`
`VF=
`
`TRANSFER VOICE DATA FROM DSP
`
`S37
`
`S38
`
`YES
`
`SILENT?
`
`NO
`
`S39
`
`RESET SILENT
`COUNT
`
`S40
`
`one Y
`
`
`
`R
`
`S43
`RECORDING
`
`PERFORMED
`
`
`S46
`OUTPUT CONTROL
`?
`INSTRUCTION
`
`NO
`AND DATA TO
`
`
`MEMORY CONTROL
`
`CIRCUIT
`
`
`S47
`
`UPDATE INDEX
`INFORMATION
`
`UPDATE OPERATION
`POSITION
`INFORMATION
`
`
`BRTToN
`
`TOP
`
`He
`
`?
`
`RETURN
`
`5
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 5 of 14
`
`6,031,915
`
`FIG.5
`
`RECORDING MODE
`DETECTION ROUTINE
`
`TURN ANALOG SWITCHES A AND B OFF
`
`S50
`
`TURN ANALOG SWITCHES C AND D OFF
`
`S51
`
`OUTPUT SAWTOOTH WAVEOF 3kHz
`FROM D/A CONVERTER
`
`RECIEVE INPUT (SAMPLE)
`FROM A/D CONVERTER
`
`SET VALUE OF VOICE START OR SILENCE
`ON THE BASIS OF SAMPLE VALUE
`
`S52
`
`S53
`
`S54
`
`TURN ANALOG SWITCHES C AND D OFF
`
`S95
`
`TURN ANALOG SWITCHES A AND B ON
`
`S56
`
`6
`
`

`

`Feb. 29, 2000
`
`Sheet 6 of 14
`
`6,031,915
`
`U.S. Patent
`
`I)
`
`
`
`
`
`GaSIOANNdaSIOANNGaSIOANN
`
`€GNNOSZGNNOStGNNOS
`
`ADIOA
`
`ADYANA
`
`J3A31SSIONS9NITIS
`
`
`
`(A1gVINVA)O=A
`
`WILWHOSASAVMADYSNS
` ™_wunnipilHWtyiai
`|L=AL=A
`
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`
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`LYVHO
`
`
`
`
`
`LYWHDWHOSSAVMSDIOA
`
`JADIOA
`
`7
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 7 of 14
`
`6,031,915
`
`FIG.7
`
`
`
`
`
`
`CODING IN DSP AND DETERMINATION OF
`VOICED AND UNVOICED SOUNDS
`
` S81
`
`INPUT VOICE DATA
`(FRAME PROCESS)
`
`
`PERFORM PREPROCESS
`
`VOICE CODING PROCESS
`
`CALCULATE VOICE ENERGY
`
`S82
`
`S83
`
`S84
`
`YES
`
`IS
`
`S85
`
`EQUAL TO OR HIGHER
`THAN NOISE LEVEL
`(VOICED SOUND)
`?
`
`
`S87
`
`
`
`
`
`iS
`CHANGE
`paEOUS ee
`FRAME INTO
`>
`CODE OF
`S93
`Y NO
`
`(VARIABLE AT
`ena
`NOISE LEVEL)
`
`S88
`<2
`S92
` ADD
`
`VOICE ENERGY
`
`
`S86
`
`Is
`NO
`PREVIOUS
`$89
`FRAME
`SILENT
`
`?
`YES
`
`No
`
`is
`PREVIOUS FRAME
`SILENT
`2
`
`S94
`
`S95
`
`YES
`
`UNVOICED
`CODE
`
`
`
`RETURN
`
`S96
`
`ADD
`VOICED
`CODE
`
`ADD
`SILENT
`CODE
`
`8
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 8 of 14
`
`6,031,915
`
`
`
`REPRODUCING
`PROCESS
`
`
`
`DETECT VOICE REPRODUCING
`CONDITION MODE
`
`
`
`S61
`
`TRANSFER(INSTRUCT) VOICE
`REPRODUCING CONDITION MODE TO DSP
`
`LOAD REPRODUCING POSITION
`DISPLAY REPRODUCING START
`
` S62
`
` S63
`
` S64
`
`OUTPUT ADDRESS TO MEMORY
`CONTROL CIRCUIT
`
`
`
`
`S65
`
`LOAD VOICE DATA
`
`RAPID HEARING
`PROCESS?
`
`Yes
`
`|
`
`S66
`
`
`
`LOAD VOICE DATA
`
`S67
`
`
`
`NO
`
`
` S70
`
`TIME AXIS
`COMPRESSION
`
`
`
`TRANSFER TO DSP
`
`S71
`
` UPDATE REPRODUCING
`
`
`
`
`
`
`DATA POSITION
`'
`
`STOP BUTTON ?
`
`YES
`
`RETURN
`
`S72
`NO
`
`
`9
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 9 of 14
`
`6,031,915
`
`LINDHID
`
`
`
` {nodD}avidsia6aom8
`
`AGQGNLS——
`
`Vol
`
`
`
`AlddNSY3MOd
`
`YATIOULNOD
`
`Wwuldid
`
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`O|MAH—/:ddSe
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`oar2]|ewosesSouei?chL
`
`10
`
`10
`
`
`
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 10 of 14
`
`6,031,915
`
`FIG.10
`
`S712]
`
`NO
`
`?
`i YES
`
`S127
`
`TANDBY
`B TTON ON
`
`NO
`
`
`
`STANDBY
`STATE ?
`
`NO
`
`YES
`
`RETURN
`
`ats
`
`YES
`
`S124
`
`
`
`
`
`
`11
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 11 of 14
`
`6,031,915
`
`FIG.11
`
`OPERATION IN RECORDING PROCESS
`IN DIGITAL SIGNAL PROCESSOR
`
`INPUT VOICE DATA
`(FRAME PROCESS)
`
`S14
`
`PERFORM PREPROCESS
`
`S142
`
`PERFORM VOICE CODING PROCESS
`
`S143
`
`CALCULATE VOICE ENERGY
`
`S144
`
`TRANSFER ENERGYLEVEL
`TO SYSTEM CONTROLLER
`
`S145
`
`12
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 12 of 14
`
`6,031,915
`
`FIG.12
`
`START
`
`
`
`
`
`
` RECORDING BUTTON
`
`BEEN PRESSED FOR 1
`
`OND_OR MORE
`
`
`
`
`
`
`IS VOICE
`INPUT LEVEL EQUAL
`TO OR HIGHER THAN
`PREDETERMINED
`LEVEL
`
` VOICE START
`
`RECORDING STATE
`
`ANOTHER BUTTON
`
`
`
`
`BEEN oo
`
`13
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 13 of 14
`
`6,031,915
`
`FIG.13
`
`
`
`
`HAS
`
`
`RECORDING BUTION
`BEEN PRESSED,
`
` YES
`
`FOR1 SECOND
`
`
` THAN VOICE INPU
`LEVEL EQUAL TO OR SHER
`
`S304
`
`
`VOICE START
`RECORDING STATE
`
`
`S308
`
`
`
`NO
`
`
`
`START
`
`S301
`
`S302
`
`HAS
`RECORDING BUTTON
`BEEN PRESSED
`
`
`IS
`VOICE INPUT
`
`LEVEL ?
`
`S307
`
`
`
`SET ORDINARY
`RECORDING
`MOD
`
`
`
`
`
`|
`
`
`
`
`
`HAS
`RECORDING
`BUTTON BEEN
`
`PRESSED
`
`
`YES
`
`
`
`14
`
`14
`
`

`

`U.S. Patent
`
`Feb. 29, 2000
`
`Sheet 14 of 14
`
`6,031,915
`
`FIG.14
`
`
`
`IS VOICE
`
`LEVEL EQUAL TO OR
`HIGHER THAN
`
`PREDETERMINED
`LEVEL
`
`
`
`
`
`VOICE START
`
`START S407
`
`
`YES S404
`
`
`15
`
`

`

`6,031,915
`
`1
`VOICE START RECORDING APPARATUS
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`invention relates to a voice start recording
`The present
`apparatus and, more particularly, to a voice start recording
`apparatus which automatically starts/stops a
`recording
`operation in response to predetermined voice.
`2. Related Art Statement
`
`2
`the set switch for the voice start recording function. In this
`case, a predetermined operation must be performed to oper-
`ate the voice start recording function.
`However, when devoted operation members correspond-
`ing to the functions described above are independently
`arranged,
`the apparatus itself increases in size, and the
`increase in size of the apparatus limits a compact design. In
`addition, workability in an assembling operation is degraded
`with an increase in the number of members, and manufac-
`turing costs may disadvantageously increase.
`When the operation member or the like for the voice start
`recording function is also used as an operation member for
`another function, in use of the apparatus, the operability of
`each operation memberis degraded.
`When the operation member or the like for the voice start
`recording function is also used as an operation memberfor
`another function,
`in general, a general contact-fixed type
`mechanical slide switchor the like is generally applied. In
`this case, unless an operation such as a mode switching
`operation is performed, the recording apparatusis fixed to a
`mode state set by the above operation memberor thelike.
`Therefore, when use of the above recording apparatus or
`the like is to be started by another set mode but a set mode
`set when the apparatus is previously used, a switching
`operation or the like is performed prior to the start of use,
`and a switching operation to a desired set mode must be
`performed. Thatis, a preparing operation before use of the
`recording apparatus is started is disadvantageously cumber-
`some.
`
`OBJECTS AND SUMMARY OF THE
`INVENTION
`
`It is a first object of the present invention to provide a
`voice start recording apparatus which is not erroneously
`operated by external noise.
`It is a second object of the present invention to provide a
`voice start recording apparatus which can reliably and easily
`set a voice start level and a recording standby level.
`It is a third object of the present invention to provide a
`voice start recording apparatus which can easily set a mode
`for a voice start recording function without specially arrang-
`ing a devoted operation member for operating the voice start
`recording function.
`Briefly, the voice start recording apparatus according to
`the present invention includes the following means:
`voice level determining means for determining whether
`input voice is sound or silent in units of frames, each of
`which codes a voice signal;
`continuity monitoring means for monitoring continuity of
`a soundframe or a silent frame; and
`recording control means for controlling the start and stop
`of a recording operation on the basis of an output from
`the continuity monitoring means.
`These as well as other objects and advantages of the
`present
`invention will become further apparent
`from the
`following detailed expression.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a block diagram showing the arrangement of a
`voice start recording apparatus according to a first embodi-
`ment ofthe present invention;
`FIG. 2 is a view showing the recording arrangement of a
`semiconductor memory section in the voice start recording
`apparatus according to the first embodiment;
`
`15
`
`20
`
`30
`
`n
`
`In recent years, there is provided a recorder in which a
`voice signal obtained by a microphone orthe like is con-
`verted into a digital signal, the digital signal is stored in, e.g.,
`a semiconductor memory, the voice signal is read from the
`semiconductor memory to be converted into an analog
`signal in a reproducing operation, and the analog signal is
`outputted as voice by a loudspeaker or the like. Japanese
`Unexamined Patent Publication No. 63-259700 discloses an
`example of the recorder described above.
`In the general recorder type described above, in order to
`save an amount of data recorded on the semiconductor
`memory, an amount of generated data is decreased as much
`as possible by performing high-efficient coding to a digital
`voice signal.
`There is also provided a scheme of performing a com- 2
`pressing process to a silent portion to obtain the high
`efficient coding. It is generally knownthat general dialogue
`includesa silent portion, andthat a bit rate can be decreased
`by about 30% by compressing the silent portion.
`As a voice recording apparatus, ¢.g., a tape recorder for
`conference recording, a recorder which automatically starts
`a recording operation in response to voice and stops the
`recording operation a predetermined period of timeafter the
`voice is interrupted is known. In a recording standby state,
`when such a recorder receives voice having a predetermined
`start
`level
`(adjustable by a user),
`the recorder starts a
`recording operation. When the input voice has a level lower
`than the predetermined level, the recorder stops the record-
`ing operation 3 to 4 secondslater.
`More specifically, when voice having a level equal to or
`higher than the predeterminedstart level, the recorder deter-
`mines that “sound” is set to start a recording operation; when
`the input voice has a level lower than the predetermined
`level, the recorder determinesthat “silence”is set to stop the
`recording operation.
`However, in the recorder described above, the following
`drawbacks occur. That is, a recording operation is errone-
`ously started by environment noise such as sound generated
`by opening/closing a door or coughs, and the recorder
`cannot be stopped when the recorder must be stopped
`because of external noise. In addition, a leading portion is
`disadvantageously cut at the start of a recording operation.
`In the voice recording apparatus comprising an automatic
`voice starting function, a start/stop level of a recording
`operation is fixed in the apparatus itself, or a user must
`operate a volumeora sensitivity switching switch to set the
`level to be a desired start level in advance.
`
`40
`
`$0
`
`55
`
`However, a means for setting the start/stop level cannot
`easily set a proper level by catching input voice which
`always changes, and the start level must be sought after a
`trial recording operation is performed.
`In the above voice start recording apparatus, as a setting
`switch to operate the voice start
`recording function, a
`devoted operation member must be arranged. If the devoted
`operation memberis not used, a setting switch having a
`rapid hearing reproducing function or the like is also used as
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`FIG. 7 is a flow chart showing a routine of a process of
`determining voiced sound, unvoiced sound, andsilence and
`a coding process in the voice start recording apparatus
`according to the first embodiment,
`FIG. 8 is a flow chart showing a subroutine of a repro-
`ducing process in the voice start recording apparatus accord-
`ing to the first embodiment:a reproducing operation in a
`voice recording/reproducing apparatus accordingto a fourth
`embodiment of the present invention;
`FIG, 9 is a block diagram showing the arrangement of a 3
`voice start
`recording apparatus according to a second
`embodiment ofthe present invention;
`FIG. 10 is a flow chart showing a subroutine of a
`recording process in the voice start recording apparatus
`according to the second embodiment;
`FIG, 11 is a flow chart showing an operation of a digital
`signal processor in a recording process in the voice start
`recording apparatus according to the second embodiment;
`FIG. 12 is a flow chart showing an operation of a system
`controller when a recording operation is performedin a third
`embodiment of the present invention;
`FIG, 13 is a flow chart showing an operation of a system
`controller when a recording operation is performed in the
`fourth embodiment of the present invention; and
`FIG. 14 is a flow chart showing an operation of a system
`controller when a recording operation is performed in a fifth
`embodiment of the present invention.
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
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`level is a voice level which satisfies predetermined condi-
`tions. The voice level which satisfies the predetermined
`conditions means a voice level which is equal to or higher
`than a reference level or which is lower than the reference
`level. For example,
`in this embodiment, “sound”is deter-
`mined when the level is equal or higher than the reference
`level, and “silence” is determined when the level is lower
`than the reference level. Therefore, when the reference level
`is set as described above, it can be determined whether input
`voice is “sound”or “silence”.
`
`“Silence” does not always mean that the voice level is
`zero. As described above, a certain reference level is set.
`When an input level is lower than the reference level, it is
`determined that it is “not sound”, and “not sound” can be
`recognized as “silence”,
`In addition, the system controller 6 determines the voice
`levels in units offrames each of which codesa voice signal.
`The system controller 6 also functions as a continuity
`monitoring means which monitors the continuity ofa frame
`of a voice level which satisfies the predetermined
`conditions, ¢.g., a sound frame or a silent frame. The above
`frame units will be described later.
`
`The system controller 6 also functions as a recording
`control means for controlling the start or stop of a recording
`operation on the basis of the continuity monitor result. Note
`that
`the details of the recording control means will be
`describedlater. In this case, a monitoring operation for the
`continuity of a sound frame or silent frame performed by the
`continuity monitoring means may be performed in the
`following manner. As in a method (to be described later, in
`place of actual counting of the number of frames,
`for
`example, time is measured using a timer, and it is monitored
`whether the sound frame or the silent frame continues for a
`predetermined period of time or more.
`The voice start recording apparatus of this embodiment
`comprises a loudspeaker 13 serving as a voice output means.
`The loudspeaker 13 is connected to a secondterminal D2 of
`the system controller 6 through an analog switch 30, an
`amplifier (AMP) 12, and a digital/analog (D/A) converter
`il.
`
`The analog switch 26 is connected to a control terminal
`E1 of the system controller 6, and is controlled to be turned
`on in a recording operation. The analog switch 30 is con-
`nected to a control terminal E2, andis controlled to be turned
`on in a reproducing operation.
`An analog switch 27 is connected between the AMP 12
`and the analog switch 30, and is also connected to the
`voltage supply terminal ofa variable resistor (VR) 28. The
`analog switch 27 is connected to a control terminal E3 of the
`system controller 6, and is controlled to be turned on when
`the state of the variable resistor 28 is detected.
`
`An analog switch 29 is connected between the A/D
`converter 4 and the analog switch 26, and is also connected
`to the intermediate tap terminal of the variable resistor (VR)
`28. The analog switch 29 is connected to a control terminal
`E4ofthe system controller 6, and is controlled to be turned
`on when the state of the variable resistor 28 is detected.
`
`The variable resistor 28 is used to change the threshold
`value of a reference level when the system controller 6
`serving as the voice level determining means determines
`whether the level is sound orsilent. At this time, the system
`controller 6 and the variable resistor 28 function as threshold
`value setling means.
`When the timing of the start or stop of a recording
`operation is changed by changing the number of predeter-
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`FIG. 3 is a flow chart showing a main operation in the
`voicestart recording apparatus according tothe first embodi-
`ment;
`
`FIG, 4 is a flow chart showing a subroutine of a recording
`process in the voice start recording apparatus according to
`the first embodiment;
`FIG. 5 is a flow chart showing a subroutine of a recording
`mode detecting process in the voice start recording appara-
`tus according to the first embodiment;
`FIG. 6 is a graph showing the relationship between a
`voice energy waveform and a voice waveform when voiced
`sound, unvoiced sound, and silence are determined in the
`voicestart recording apparatus according to the first embadi-
`ment;
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`Embodiments of the present invention will be described
`below with reference to the accompanying drawings.
`FIG. 1 is a block diagram showing the arrangement of a
`voicestart recording apparatus according to the first embodi-
`ment of the present invention.
`As shown in FIG, 1, the voice start recording apparatus
`according to this embodiment comprises a microphone 1, A
`voice signal from the microphone 1 is input to an analog/
`digital (A/D) converter 4 through an amplifier (AMP) 2, a
`low-pass filter (LPF), and an analog switch 26. An output
`terminal of the A/D converter 4 is connected to a first
`terminal D1 ofa system controller 6.
`This system controller 6 incorporates a voice
`compressing/expanding means, a time axis compressing
`means, a means for detecting or predicting an input signal
`level, a digital signal processor (DSP) 5 serving as a
`constituent element of a data processing means, The first
`terminal D1 is connected to the digital signal processor
`(DSP) 5 in the system controller 6.
`The system controller 6 also functions as a voice level
`determining means for determining whether an input voice
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`mined frames which are continuously detected, the variable
`resistor 28 is used to change the timing. At this time, the
`system controller 6 and the variable resistor 28 function as
`recording timing changing means.
`A third terminal D3 of the system controller 6 is con-
`nected to a memory control circuit 7, and a fourth terminal
`D4 is connected to a semiconductor memory section 10
`which is detachable from the recording/reproducing appa-
`ratus.
`
`A fifth terminal DS of the system controller 6 is connected
`to a light-emitting diode 17 serving as a data transmitting
`meansfor transmitting data recorded on the semiconductor
`memory section 10 or an output means for outputting at
`signal representing a receivable. An infrared-emitting diode
`is used as the LED 17 when the LED 17 is used to transmit
`data. However, the LED 17 is also used as a display unit
`which emits light when soundis input to or output from the
`microphone | during a recording or reproducing operation.
`Therefore, as the LED 17, an infrared LED which
`includes a large amountofvisible light component and has
`a relatively short wavelength having, ¢.g., a peak wave-
`length of 500 mm to 1,000 mm, preferably, 600 mm to 800
`mm.
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`As shown in FIG. 1, the semiconductor memory section
`10 comprises a temporary recording medium portion 100d
`and a main recording medium portion 100b. Although a flash
`memory is generally used as the main recording medium
`portion L00b, an magneto-optical disk, a magnetic disk, or
`a magnetic tape is used as the main recording medium
`portion 100b. As the temporary recording medium portion
`100a, an SRAM, a DRAM, an EEPROM, a highdielectric
`memory, or a flash memory, which can perform reading/
`writing at a speed higher than that of the main recording
`medium portion 100b, may be employed.
`In this
`embodiment, an SRAM is used as the temporary recording
`medium portion 100¢, and a flash memory is used as the
`main recording medium portion 100b.
`FIG, 2 is a view showingthe recording arrangementof the
`semiconductor memory section 10.
`As shown in FIG, 2, the memory space of the semicon-
`ductor memory section 10 is roughly divided into an index
`portion LOA and a voice data portion LOB. In the voice data
`portion LOB, a plurality of voice messagefiles 10B1, 10B2,
`10B3,
`.
`.
`.
`, 10Bm which are recorded on the voice data
`portion LOB are recorded.
`In the index portion LOA, the following information are
`recorded. That is, the index portion 10A is constituted such
`that next voicefile start address position information L0A1;
`one-file size information 10A2;
`file erasing information
`10A3; a recording file number 10A4; voice coding scheme
`recognizing information L0A5; information 10A6 represent-
`ing a file state; maximum value information LOA7 ofa file
`which can be edited (inserted); information 10A8 represent-
`ing a length to an insertable file; an edition start position
`address 10A9 of the first edition; a start position address
`10A10 of an inserted voice file of the first edition; and size
`information LOAL1, .. .
`; an edition start position address
`10A12 of the nth edition in which maximum information
`can be performed to sequentially record information similar
`to the information 10A9 to 1O0AI1; start position address
`10A13 of an inserted voice file of the nth edition in which
`maximum insertion can be performed; and start position
`address 10A14 ofan inserted voice file of the nth edition in
`which maximum insertion can be performed are recorded.
`The voice frame data 10B1 to LOBmare recorded on the
`voice data portion LOB. In each frame data of the voice data
`portion LOB, information representing whether initial setting
`is performed when the voice coding process is performed is
`recorded.
`
`In addition, a sixth terminal D6 of the system controller
`6 is connected to a display unit 8 through a drive circuit 9.
`A memory control circuit 7 of the system controller 6 is
`connected to a contact point between a PIN diode 14 and a
`resistor 15 through a voltage comparator (COMP) 16 and
`terminal D7 of system controller 6.
`In this case, the PIN
`diode 14, and the voltage comparator 16 constitute a data
`receiving means or a meansfor receiving a data transferstart
`signal.
`An eighth terminal D8 of the system controller 6 is
`connected to a battery 18 through a DC-DC converter 20 and
`a main power supply switch 19. The DC-DC converter 20
`outputs a voltage boosted from the battery 18, and supplies
`a stable power supply voltage to each means. At the same
`tide,
`the DC-DC converter 20 transmits a signal which
`notifies that the voltage of the battery 18 is smaller than a
`predetermined value. In this manner, the system controller 6
`detects a consumptionstate ofthe battery 18.
`The main power supply switch 19 is connected in series
`with a relay 25 such that power supply is prevented from
`being stopped even if the main power supply switch 19 is
`turned off. In order to detect that the main power supply
`switch 19 is turned off, the main power supply switch 19 is
`The position at which the information is recorded is
`connected to the system controller 6 such that the voltage of
`allocated to the uppermost bit or lowermost bit of the first
`the battery 18 can be detected when the main power supply
`switch 19 is turned off.
`byte of each framedata, or is allocated to the uppermost bit
`or lowermostbit of the last byte of the frame data. In this
`In addition, the anode of a diode 21 is connected to a ninth
`embodiment, the information is recorded at the fourth bit of
`terminal D9 of the system controller 6, and a parallel circuit
`the first byte of the frame data.
`constituted by a capacitor 22 and a resistor 23 is connected
`In the semiconductor memory section 10, an address
`between the cathode and ground of the diode 21. The
`cathode of the diode 21 is connected to the base of a
`serving as information representing a recording position of
`transistor 24. The collector of the transistor 24 is connected
`voice information is stored in the detachable semiconductor
`to a contact point between the microphone 1 and_the
`memory section 10. However, the address may be recorded
`microphone amplifier 2, and the emitter is connected to the
`in a semiconductor memory (not shown) controlled by the
`ground. These constitute an AGC (Auto Gain Control)
`memory control circuit 7 arranged on the recording/
`circuit
`to reduce generation of distortion caused by an
`reproducing side.
`In this case, the Instruction mark and END mark are as
`excessive input.
`follows. That
`is, when the Instruction mark button I
`is
`In addition, operation buttons such as a recording button
`(REC), a reproducing button (PLAY), a stop button (STOP),
`operated by a document recording person during a recording
`a fast feeding button (FF), a first rewinding button (REW),
`operation, an indicating index mark for a typist or secretary
`can be recorded. The document recording person can prac-
`an Instruction mark button (1), an END mark button (E), and
`a voice start
`(voice active detector) button (VAD) are
`tically indicate attention in typing or the priority with voice
`connected to the system controller 6.
`by using the Instruction mark.
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`In order to indicate partitions between the plurality of
`documents, the END mark button E is operated to record an
`index mark called an END mark.
`
`A recording/reproducing operation of the first embodi-
`ment arranged as described above will be briefly described
`below.
`
`When a recording operation is to be performed, an analog
`voice signal obtained from the microphone 1 is amplified by
`the microphone amplifier 2 to limit the frequency bandof the
`analog voice signal through the low-passfilter 3, and the
`analog signal is converted into a digital signal by the A/D
`converter 4 to be inputto the digital signal processor (DSP)
`5 in the system controller 6.
`In this case, when a signal input from the microphone 1
`is higher than a referencelevel, e.g., higher than -6 dB ofthe
`maximum range of the A/D converter 4, a pulse is output to
`the diode 21 connected to the ninth terminal D9 of the
`
`system controller 6, and charges are stored in the capacitor
`22 to apply a voltage to the transistor 24. At this time, an
`impedance between the microphone amplifier 2 and the
`transistor 24 changes, and a signal input to the microphone
`amplifier 2 is limited, thereby adjusting a gain. Note that the
`charges stored in the capacitor 22 are gradually discharged
`by the resistor 23.
`In response to an operation of a plurality of operation
`buttons and switches of the system controller 6, voice data
`obtained by compressing a digital signal by the digital signal
`processor 5 is recorded on the semiconductor memory
`section 10 through the third terminal D3 and the fourth
`terminal D4 of the system controller 6.
`In a reproducing operation, the system controller 6 reads
`data recorded on the semiconductor memory section 10 and
`supplies the data to the digital signal processor 5 to expand
`the data. The voice data expanded by the digital signal
`processor 5 is converted into analog signals by the D/A
`converter 11, amplified by the AMP 12, and then output as
`voice from the loudspeaker 13. The system controller 6
`controls the drive circuit 9 to cause the display unit 8 to
`display various information such as an operation mode.
`An operation of the voice start
`recording apparatus
`according to this embodiment arranged as described above
`will be described below.
`
`FIG. 3 is a flow chart showing a main operation in the
`voice start recording apparatus according to this embodi-
`ment. The operation will be described below as an operation
`of the system controller 6.
`When the battery 18 is set to supply power, the system
`controller 6 starts the operation shownin the flow chart. That
`is, the external conditions of the system controller 6 and
`initial setting of the storing section in the system controller
`6 are performed (step S1).
`Upon completion ofinitial setting, the system controller
`6 detects whether the power supply voltage ofthe battery 18
`is a rated value (step $2). The rated value is set to be 1 V,
`and the system controller 6 detects, on the basis of infor-
`mation from the DC-DC converter 20, whether the power
`supply voltage of the battery 18 is 1 V or higher or whether
`the impedance of the battery 18 from a current flowing in the
`battery 18 is larger than the rated value. At this time, a signal
`obtained by determining the state of the battery 18 is input
`to the eighth terminal D8 of the system controller 6, so that
`the system controller 6 can detect whether the battery 18 has
`a usable capacity (step 82).
`If the system controller 6 detects that the battery 18 cannot
`be used as a detection result in step S2, power supply to the
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`recording apparatus is stopped, and
`entire voice start
`switches (not shown) arranged between the battery 18 a