PH26535A - Signal recording and/or reproducing apparatus - Google Patents

Description

i This invention relates to recording and/or reproduction of video signals by using a recording and/or reproducing device for still images such as so~called electronic still camera devices.

In the Japanese Laid~Cpen Utility lMHodel

Publication Ho. 197,021/1982 are known electronic .8till camera devices provided with image pickup de- vices such as CCDs and adapted to record one~field or one-frame signals on a magnetic disk.’

In these devices, video signals from the image pickup devices are taken under gating one field or . one frame at the time point of a given shutter ope- Er ration, these signals being recorded on the magnetic L disk so that one field will complete one circular track. It is noted that one-frame signals are re= corded by using two tracks. It is therefore pos~ o ; sible with these devices to form video signals of : oo 5 the still image by repeatedly reproducing one track or by alternately repeatedly reproducing two trackse

With these devicesy it has also been proposed to make it possible to record speech signals. To this end, it would be feasible to compress the audio i signals along time axis by employing, for exampley - digital signal processing to elevate the frequency’ of the audio signals to that of the video signals , -2- :

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CAEL a LT Ey : for recording by using the same recording system as that of the video signals.

It will be noted in this connection that the audio signals up to, for example, 5 kliz may be com- pressed along time axis to 600 times to provide the signals of the 3 MHz video frequency. In this case, audio signals of ca. 10 seconds, which is B00 times one field period (1/60 second) can be recorded dur= ' \ ing the one field period. : : 10 However, an extremely large memory unit would . be required for digitally processing the audio sige 3 nals of, for example, 10 seconds. While it would . : be feasible to quadrisect the 10 second period and - to process the 2.5 second interval. each 2.5 second } : | interval, it would be difficult, in case of dividing Co into plural portions or segnents for recording, to: 7 maintain the continuity of the respective segments during reproduction. i n

When it is desired to record the audio sige oo nals of the longer duration than said 10 seconds, oo } recording would be made across plural tracks. 6 is similarly extremely difficult to maintain the Co a track continuity during reproduction. , The above is the construction of the priore art devices. In these devices, when the recording : ; ~ _ 3 - ; :

is segmented or effected over plural tracks, it has been extremely difficult to maintain signal continuity during signal reproduction.

The present invention provides a magnetic regording/reproducing device wherein one-field video signals are sequentially recorded as one track, and wherein audio signals are compressed along time axis (22), (25) so as to be recorded (6) on the track in place of said video signals, characterized in that the continuous audio signals are divided into plural

Segments and recorded on memory means (14) of shorter duration than the time during which said audio sig- nals are continuously recorded after said time axis compression, and in that start identification signals

SID are provided at the leading edge of the seg= : ment signals, said signals SID being used during reproduction for expansion and continuation (52), (55) of ‘the time-axis~compressed signals. /Operation/ .

In the above device, the start identification’ signals at the leading edge of each segment can be - used for optimal facilitated continuation of the red N a produced signals. It is noted that ‘continuation : between the adjoining tracks can be effected similar ly to the continuation between the adjoining segments. ; - bo.

BRIEF DESCRIPTION OF THE DRAWINGS Co.

FIG. 1 is a block view of the reaording system according to the present invention;

FIG. 2 is a block view of the reproducing system according to the present invention; } FIG. 3 A and B are timing charts showing the time~ball compression of audio signals adcording to the present invention;

FIG. 4 A and B represents signal wave forms show=- ing the timing of the audio signals written into a memory according to the present inventionj

FIG. 5 is 4 diagrammatic representation of waveforms showing signal formats for sound or voice signals recorded.

FIG. 6 is a schematic showing the signal iden- tification sensor;

FIG. 7, A through H, represent signal wave- ’ forms showing the timing of the operation of the sensor of Fig. 6. :

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In Fig. 1, video signals are supplied at in- put terminal (1), converted at the recording cir= cuit (2) into predetermined recording signals, BUD plied by way of a preemphasis circuit (3) of non~ linear characteristics to an FM gircuit (5) so as to be recorded as FN signals on the disk D by the magnetic head (6).

The audio signals are supplied to the input terminal (11) and to the AD converter (13) through } an encoder circuit (12) of the noise reduction system.

These digitized signals are supplied to the memory circuit (1%). The sampling signals of the audio signals of the 5 kHz bandwidth are generated in an oscillator (21), these signals being supplied to an - address counter (22) driving the AD converter (13) and the memory (14). There is also provided an os- cillator (23) having an oscillation frequency 600 times that of the aforementioned oscillator (21), with the signals from the oscillator (23) supplied to the address counter (22). The pulses related with the rotational phase of the disk D from a mag=~ netic piece provided to a predetermined portion of the disk are sensed by a pickup (24), this signal be-~ ing supplied to a memory controller (25). Then, for . example, at each 2.5 seconds which is a quadrisection . of 10 seconds, the signals written into the me¢mory ) (14) are read at the 600 times rate, with the timing read with a phase delay of 1/h of a period af each 25. 2.5 seconds with respect -to the rotational phase from ,

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; | wn LD . . . the head (24), as shown in Fig. 4.

These signals are supplied to the DA con- verter (15). To this converter (15) are supplied signals from the oscillator (23). These converted analog signals are supplied by way of a mixer (16) to the preemphasis circuit (17) having the linear characteristics and the signals from the preemphasis circuit (17) are supplied by way of changeover switch (I) to the THM circuit (5) to be converted into FM © 10 signals and recorded on the disk D by the magnetic ‘ head (6). | i } i : | In this circuit start identification signais i

SID and end identification signals Zp as shown in’ i

Fig. 5 are inserted in the mixer (16) connected ’ between the DA converter (15) and the preemphasis 0 circuit (17) at preset time before and after the: i ! time axis compressed audio signals. | It is noted " te ¥ that these identification signals are supplied by, : + for example, the signals ‘from the memory controller 5 : (25) supplied to the identification signal generator ~ (26). It will be noted that the identification sig~ - : i ’ . b, . a nals are distinct in profile from audio signalss a,

That is, the low frequency of the dato signals in i : the above circuit are limited to a preset value, so se

Po CT that any pulse having a width longe# than the pulse | ed a | Sb 8 ! yoo : : . so

ER ; i by he oo WE corresponding to the frequency of the preset value u, can be distinguished upon time axis compression, -

For example, start identification signals are of positive polarity with the reference being its . “ 5 falling edge and the end identification signals are of negative polarity with the reference being ' its rising edge.

Referring to Fig. 2, signals reproduced from the disk D at the magnetic head (31) are supplied ’ to the FM modulation circuit (32). When the demb- dulated signals are video signals, these signals are taken at the output terminal (35) through the - . . deemphasis circuit (33) of the non-linear charac= teristics and the reproducing circuit (34). . when the demodulated signals are audio sig= nals, these signals are supplied by way of the dem emphasis circuit (41) of the non-linear character s~ . tics to the AD converter (42). These converted die ‘gital signals are supplied to the memory (43). There is provided on oscillator (51) having the same frea } quency as that of the oscillator (23) with the sige nals from the oscillator (51) being supplied to the : address counter (52) driving the memory (43) and the . AD converter (42). There is also provided another i oscillator (53%) having the frequency same as that of v / . _ 8.

the above described oscillator (21), with the sig nals from the oscillator (53) being supplied to the address counter (52). The signals from the pickup head (54) equivalent to the head (24) are supplied to the memory controller (55). The signals written into the memory unit (43) are read out at 1/600 gpesed by the reverse of the operation used during re- cording shown in Fig. 4.

The signals thus read out are supplied to the

AD converter (44), To this converter (4k) are sup= plied signals fromthe oscillator (53). These con- Se verted analog signals are taken at the output termi- nal (46) by way of the decoder uEy A es i In this circuit, output signals from the de~ : : 15 emphasis circuit (41) are supplied to the detection circuit (56) for the identification signals. The ‘ detection circuit (56) is constructed as shown for ’ example in Fig. 6. In this circuit, signals from : the deemphasis circuit (41) are supplied to the in- put terminal (61) which is supplied to a falling edge detective differentiating circuit (62), a fall=- ing edge detective differentiating circuit (63), and a lopass filter (64), so that signals as shown in

Fig. 7A, B and C are recovered. Of these signals, those. from the lowpass filter (64), Fig. 7D, are oo / i “9 - { ’

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Co ' supplied to comparators (65), (66) having the de- : tection levels shown at broken lines a and by result- ing in signals shown at E and F in Fig. 7. These signals are supplied to NAND circuits (67), (68) . 5 and the signals from the associated differentiating circuits (62), (63) are supplied to the NAND circuits (67), (68). Thus, from the NAND circuit (67) are de~ tected the falling edges of the start identification " signals SID as shown in Figl 7F to be taken at the x 10 output terminals (69). From the NAND circuit (68) are detected the rising edges of the end identifica~

LL tion signals EID and taken at the output terminal (70), as shown at G in Fig. 7. Ca

These signals are supplied to the memory con troller (55) so that, when the falling of the signals

SID is sensed, signal sampling and sriting is started since time T, shown in Fig. 5. signal writing is - continued by the signals from the osoillator (51) and yo - terminated when the rising of the signals EID is sensed. The address counting of the memory unit . (43) is reset by an amount Ts shown in Fig. 5. This

This operation is repeated for each segment such - ' that signals consisting of annexed audio signal pore tions are written into the memory unit (43)e . : : 25 | In the above circuit, when an overlap is prow : wm 10 ~ i

: Cl Co vided to the audio signals between the respective segments, the address is counted down by Ts + of . (corresponding to the overlap) when counting down ’ the address of the memory unit (43). This is effective to prevent signal discontinuities due to for example, jitter components. :

Signal continuation for the case in which signals are recorded on plural tracks &an be achieved in the similar manner.

The above is the manner of audio signal res . oo cording and reproduction. According to the above described device, reproduced signals can be annexed inte continuous signals very easily and satisfactorily : by the provision of the start identification signals.

According to the present invention, since the

Start identification signals are provided at the leade : ing edge of each segment, these signals can be ade vantageously employed for cont inuatibn of the repros= duced signals very easily and satisfactorily by make : 20 ing use of these signals. ; je -

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Claims (3)

1. WHAT IS CLAIMED IS:

   lo. Apparatus for use with an analog signal recording and reproducing system of the kind wherein a field of a video signal representing a still image . S is recorded on a selected one of a plurality of con=~ centrically arranged tracks on a rotary record medium and an audio signal associated with the still image is recorded on another concentrically arranged selected track of the record medium, the apparatus comprising: Co 10 means for recording a field of the video sige nal representing a still image; . means for dividing an audio signal having a known length and associated with the rem ' corded still image into & plurality of audio ' . 15 signal segments; : means for time-base compressing each of said’ plurality of audio signal segments and ine cluding a memory having a predetermined memory duration capacity at a selected clock frequency that is less than said known length of said audio signal associated with the ree corded still image} . means for generating segment Btart and end identification signals for each of said time~base compressed audio signal segments}

   , i \ ‘ ! - . . : means for generating control code data indie cating at least a reproduction sequence of . said tracks} means for recording each of said time-base . 5 compressed audio signal segments and said ’ segment start and end identification sige : nals and said control code data in a pre= determined relationship in corresponding ’ segments of a track other than the track in which the still image is recorded, with respective ones of said segment start and end identification signals at respective : leading and trailing edges of each said time-base compressed audio signal segments; - 15 means for detecting the location of the end identification signal in each track seg _ ment for determining the length of each time~base compressed audio ‘segment; and

   : . means for shifting the location of said end identification signal and said control code data in accordance with a determined length within a respective track segment, | Te to | so that upon reproduction said segment start and end identification signals are } S25 available following reproduction for time-

   A base expansion and annexation of the audio signal segments into a continuous audio . signal.
2. 2. Apparatus according to Claim 14 in which said means for time-base compressing each of said plurality of audio signal segments includes a write/ : read address counter for controlling said memory; first and second clock signal generators for generat— ing respective first and second clock signals fed to said write/read address counter, said first dock signal corresponding to said selected clock frequency . eo : "© w=. we-and having a frequency substantially;less than said RTO “x, . second clock frequency, whereby said write/read address counter generates write addresses at a first frequency and read addresses at a second, higher frequency. Lo
3. 3. Apparatus according to Claim 2 in which said second clock signal generator produces at second ’ "clock signal having a frequency 640 times the frequency : of said first clock signal. Co Se ] Inventor