JPH0312845A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To completely record still picture information by rewinding a magnetic tape until a recording and reproducing head corresponds to an area which is immediately before the head of the recording area of still picture information and in which still picture information is not recorded when the reproducing position of the recording and reproducing head is in the middle of the recording area of still picture information for one screen at the time of once stopping reproduction. CONSTITUTION:When a command for once stopping a reproducing action is given to a reproduction signal processing part 13 from outside, a command for rewinding the magnetic tape 12 until the recording and reproducing head corresponds to a position where an identification code ID1 changes from '1' to '0' and an identification code ID2 changes from '1' to '0', namely, to the area S2 which is immediately before the head position of the video signal recording area S3+S4 of the number N of pages shown by a code (b), and in which the video signal is not recorded is outputted from the reproduction signal processing part 13 and the tape is rewound to a point (b) and is stopped. Thus, a still picture without a lack is reproduced and displayed, and the recording of still picture information in an incomplete form can be prevented when a reproducing action or a recording action is resumed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a recording and reproducing apparatus for recording and reproducing still image information in the form of digital signals using a magnetic tape.

2. Prior Art A conventional recording/reproducing device (1-) converts an audio signal into a digital signal and records it on a magnetic tape, and also converts the digital signal recorded on the magnetic tape into an audio signal and plays it back. Digital audio tape recorder (
Digital Audi.

T a p e r e c o r d e r;
(hereinafter referred to as DAT) is well known. When DAT converts audio signals into digital signals and records them on magnetic tape, it can also record error correction information at the same time, so even if some of the recorded information is missing, it can be corrected. However, it is possible to reproduce not only the original sound faithfully but also the sound with less noise.

By the way, among the conventional I) ATs mentioned above, there are four types of operation modes: 2-channel mode, in which two channels for recording two types of audio signals individually are set on magnetic tape, and four types. There is a device that allows you to select a 4-channel mode in which audio signals are recorded individually on a magnetic tape, a 4-channel mode in which each audio signal is recorded on a magnetic tape, and a mode. In the 2-channel mode, two types of audio signals corresponding to the two speakers placed on the front left and front right sides of the listener are recorded on magnetic tape, and in the 4-channel mode, two types of audio signals are recorded on the magnetic tape. On the other hand, four types of audio signals corresponding to four speakers arranged on the front left, front right, rear left, and rear right are recorded.

In addition, in place 6 of the above 4 channel book mode, 2 of them
There is also a conventional method in which the audio signal is recorded on one channel, and the still image video signal is recorded on the remaining two channels, and the audio and video signals are played back simultaneously from one magnetic tape. better known. This method is suitable for
A still image video signal for one screen is recorded on a magnetic tape by assigning a plurality of tracks as one unit, and in a playback operation, playback is started from the stop position of the magnetic tape.

Problems to be Solved by the Invention However, in the case of the above-mentioned conventional I) AT, when the playback operation is temporarily stopped and then played back again, for example, a still image video signal for one screen on a magnetic tape is recorded. The playback may start from the middle of the recording area, and in this case, the still image can only be played back with a portion of one screen missing.

Furthermore, when starting a recording operation after once stopping two consecutive playback operations, the recording of a new still image video signal is started from the middle of the recording area where one screen's worth of still image video signals are recorded. The problem is that the old still image video signal may be destroyed by the newly recorded still image video signal, and it is difficult to replace the old still image video signal with a new still image video signal on a screen-by-screen basis. was there.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a recording and reproducing apparatus that records and reproduces still image information as a digital signal using a magnetic tape. To provide a recording and reproducing device that does not reproduce still images with partial omissions or incompletely record still image information.

Means for Solving the Problems The present invention provides a recording and reproducing apparatus for recording and reproducing still image information in the form of digital signals using a magnetic tape, in which each area of the magnetic tape is an area in which still image information is recorded. means for recording a sub-signal on a magnetic tape at the time of recording, and a means for recording a sub-signal on a magnetic tape during recording; and, at the time of playback, based on the sub-signal to be reproduced, the playback position of the recording/playback head is set to one screen worth of still image information on the magnetic tape. means for determining whether or not the playback position of the recording/playback head is in the middle of the recording area of still image information for one screen when playback is temporarily stopped; is characterized by comprising means for rewinding and stopping the magnetic tape until the recording/reproducing node corresponds to an area where still image information is not recorded immediately before the beginning of the still image information recording area. This is a recording/playback device that performs

Function According to the present invention, when the reproduction is temporarily stopped, the recording and reproduction I
＼If the rad playback position is in the middle of the recording area of still image information for one screen, the recording/playback head corresponds to the area where still image information is not recorded immediately before the beginning of the recording area of still image information. The magnetic tape is rewound until it stops. Therefore, when the playback operation is restarted next time, one screen worth of still images will be played back without any omissions. In addition, when the recording operation starts after the playback operation has stopped, the old still image information is replaced from the beginning of the recording area for one screen with the new still image information, so the old still image information is not recorded. will not remain in an incomplete form.

Embodiment FIG. 1 is a block diagram showing a schematic configuration of a recording/reproducing apparatus which is an embodiment of the present invention.

This recording/reproducing device has the above-mentioned four channels in its operating state.
・It is a DAT that allows you to select the size and mode, and of the 4 channels, 2 channels are used for recording and playing back two types of audio signals, and the remaining 2 channels are used for recording and playing back two types of audio signals.
The channels are allocated for recording and reproducing still image signals.

In FIG. 1, the input terminal TR is a terminal for inputting one type of audio signal, and the audio signal in this case is, for example, the one that should be output from a speaker placed on the right side in front of the listener. It is an audio signal. Separate group) Input terminal TL
is a terminal for inputting another type of audio signal, and the audio signal in this case is, for example, an audio signal to be output from a speaker placed on the front left side with respect to the listener. Yet another input terminal TV is a terminal for inputting still image signals. These input terminals T
R, TL, and TV are the corresponding analogs.
It is connected to a digital (hereinafter referred to as A, -'D) conversion circuit 1°2.6.

, A/D conversion circuits 1 and 2 have a function of converting audio signals inputted from corresponding input terminals TR and TL into digital audio signals Di and D24 of, for example, 12 bits 1 to 1. Each output terminal of A/D conversion circuits 1 and 2 is connected to line 3,
4 to input terminals 51 and 52 of the changeover switch 5, respectively.

The A,/D conversion circuit 6 converts the video signal input from the corresponding input terminal TV into, for example, 8-bit 71-(7,
1 digital video signal D3. The output terminal of this person/'D conversion circuit 6 is connected to the data node.

An image memory 8a is connected to the data bus 7. This image memory 8a transfers one screen worth of digital video signal D3 output from the A/″D conversion circuit 6 to a data bus 7.
This is the memory for recording this through the convergence.

A parallel-to-serial (hereinafter referred to as P/S) conversion circuit 9 is separately connected to the data bus 7. This P
The /S conversion circuit 9 has a function of taking in an 8-bit digital video signal read from the image memory 8a via the data bus 7, converting it from a parallel signal to a serial signal, and outputting the converted signal.

The output terminal of this p/'''s conversion circuit 9 is connected to the input terminal 53 of the changeover switch 5.

The above-mentioned changeover switches have a function of selectively supplying the digital signals derived from the respective input terminals 51 to 53 to the output terminal 54, and the output terminal 54 is connected to the recording signal processing section 1 of the next stage.
Connected to 1.

The recording signal processing unit 11 has a modulation function that modulates an input digital signal, a sub information addition function that adds error correction and other sub information to the input digital signal, and performs this recording signal processing. The signals processed by the section 11 are recorded on the magnetic tape 12. When the above-mentioned audio signal is music, for example, a star 1-I indicating the beginning of the song is added as a sub-signal by the sub-information 1 addition function.
Sub information called control ID such as end ID indicating the end of the recording area in D and magnetic data 12, total time which is the time required for reproduction from the beginning to the middle of magnetic data 12, and reproduction for each side. Sub-information called back data indicating the required time of the song, etc. is generated.

In the case of the second embodiment, in the recording signal processing section 11,
Back data in the format shown in Table 1 below is generated as sub information 1, -) added to the digital signal.

(First pie in Table 1), the top four pieces of the PCI part (B7 to B4 are written with a back item, which is a code for identifying the content of the back data. For example, this back item (packitem) is r
``oool'' indicates that the content of the back data is the song time, ``roolo'' indicates that the content of the pack data is the total time, and rllllO
J's Thirst indicates that the contents of the pack data are still image pages.

Bit B3 of the B()-P CI part indicates whether or not the recording area of this puncture data is an area where still image information (digital video signal) is recorded in the recording area of the magnetic tape 12. An identification code IDI is written, and for example, when the identification code IDI is 1, it indicates that the area is a recording area for still image information, and when the identification code IDI is 0, it indicates that it is an area where no still image information is recorded. In bit B2 of the same byte PCI part, an identification code ID2 is written which indicates whether or not the recording area of this pack data among the recording areas of the magnetic tape 12 is the beginning of the still image information recording area for one screen. For example, ID2=1 is written in the first 10 track sections of the still image information recording area.

of the pack data shown in Table 1), each of the upper and lower 4 bits B7 to B4 of PO2, PO2. B3 to BO contain a 4-digit BCD page identification code PAGE that indicates the page number of still images.
1 to PAGE4 are written. Further, back parity, which is data for error correction of the packed data, is written in the final byte t-PC8 of each packed data, as shown in Table 1.

In FIG. 1, the reproduced signal processing unit 13 includes a magnetic tape 1
The output terminal is connected to the input terminal 154 of the changeover switch 15 via the line 14. It is connected to the. The processing function of the reproduction signal processing unit 13 indicates that the above-mentioned pack data to be reproduced when a command to temporarily stop the reproduction operation is given from the outside is located in the middle of the still image information recording area. includes a function of outputting a command 1 for rewinding the magnetic chip 112 to a position immediately before the beginning of the still image information recording area.

The changeover switch 15 has output terminals 151, 152.1
53, and has a function of selectively providing the digital signal derived from the reproduced signal processing section 13 to the input terminal 154 via the line 14 to each of the output terminals 151 to 153). Output terminals 151 and 152 are connected to the corresponding digital-to-analog (hereinafter referred to as D/'A) conversion circuit 1.
6.17 is connected.

The D/A converter circuits 16 and 17 have a function of converting the digital signals derived from the output terminals 151 and 152 of the switch 15 into analog signals. D/A conversion circuit 16
．． Each of the 17 output terminals has a corresponding output terminal TR,
1. Connected to TLI.

Another output terminal 153 of the changeover switch 15 is connected to a serial-parallel (hereinafter referred to as S/F') conversion circuit 18. This S/P conversion circuit 18 has a function of converting the digital signal derived to the output terminal 153 of the changeover switch 15 into, for example, an 8-bit parallel signal and outputting the signal. The output terminal of this 3,/2P conversion circuit 18 is connected to the data bus 7.

Connected to the data bus 7 is an image memory 8b that is different from the image memory 8a described above. These two image memories 8a and 8b serve to store digital signals output from the /P conversion circuit 18 during playback.

Further, one other D/A conversion circuit is connected to the data bus 7. This D/A conversion circuit 19 has a function of converting digital signals read from the image memories 8a and 8b into analog signals during reproduction. An output terminal of this D/A conversion circuit is connected to an output terminal TVI.

FIG. 2 is a plan view schematically showing a part of the magnetic tape 12 on which digital video signals are recorded by the DAT, and FIG. 3 shows the recording area of the magnetic tape 112 and the area shown in Table 1. FIG. 3 is an explanatory diagram showing the correspondence between the values of identification codes IDI and ID2 of pack data. Each operation of recording and reproducing the DAT will be described below with reference to FIGS. 2 and 3.

The recording input terminal TFE receives an audio signal corresponding to the speaker on the front right side of the listener, and the input terminal TI- receives an audio signal corresponding to the front left speaker. Further, a video signal of a still image is input to the input terminal TV. The audio signals input from the input terminals TR and TL are respectively sent to the A/D conversion circuit FI? For example, the digital audio signals DI and D2 are converted into 12-bit digital audio signals DI and D2 by r1 and r2, and are output as serial signals on lines 3 and 4. are applied to input terminals 51 and 52, respectively.

The video signal input from the input terminal TV is A, -'
In the D conversion circuit 1i'86, it is converted into, for example, an 8-bit digital video signal I)3, which is applied to the data bus 7 as a parallel signal. This digital video signal D3 is
The image is provided from the data bus 7 to the memory 8a. A
/' In the D conversion circuit 6, the input video signal is sampled at a sampling frequency of 14.3 MHz, for example, and converted into a digital signal. The digital video signal D3 corresponding to the video signal for one still image screen obtained in this way is 1/60 in the image memory 8 = t.
It is stored in sec.

When the writing of the digital video signal D3 corresponding to the video signal for one screen into the image memory 8a is completed, the stored digital video signal is given from the data bus 7 to the P/S conversion circuit 9, and this P/S conversion circuit 9 to the input terminal 53 of the changeover switch 5 as a serial signal.

The output terminal 54 of the changeover switch 5 has input terminals 51 to 5.
A digital signal derived from line 10 is selectively applied to recording signal processing section 1.
1 is given. In the recording signal processing unit 11, data and other sub-signals for error correction for input digital processing are added to each digital signal, subjected to signal processing such as modulation, and then recorded on the magnetic tape 12. be done.

During recording, the video signal for one screen of still images is recorded on the magnetic tape 12 shown in FIG. be done.

In FIG. 2, arrow T indicates the advancing direction of recording and reproduction on the magnetic tape 12, and areas N-1 and N have video signals of the N-1st and Nth still images recorded, respectively. shows.

Further, an area A interposed between areas N-1 and N indicates an area where no video signal of a still image is recorded. Also,
Each track is provided with the above-mentioned sub-signal recording area D (dashed line area shown in FIG. 2).

Therefore, in the pack data recorded in areas N-1 and N, the page number is N-1, respectively.
,N. In addition, in the pack data recorded in the recording area in areas N1 and N, the identification code ID1=
1, and in the pack data in area A, I
D1=O. Also, in area N, area B from the beginning to track G10, that is, the area shown in Fig. 2 with vertical hatching superimposed on the upper right hatching, has the pack data identification code ID2-1, and other For tracking, pack data identification code ID
2 = O.

Reproduction During reproduction, the signal read from the magnetic tape 12 is input to the reproduction signal processing section 13. This reproduction signal processing section 1
3, error correction processing based on the demodulation and reproduction sub-signals is performed, and the digital signal subjected to such signal processing is sent from the line 14 to the input terminal 154 of the changeover switch 15.
given to.

The changeover switch 15 has output terminals 151, 152, 153, and the output terminals 151, 152 have an input terminal TR.
,, digital signals corresponding to the audio signals input from TL are derived, and the derived digital signals are respectively D
/' After being converted into an analog signal by the A conversion circuits 16 and 17, it is output to the output terminals TRI and TLI.

A digital signal corresponding to the video signal inputted from the input terminal TV is derived from the output terminal 153 of the changeover switch 15, and the derived digital signal is given to the S//P conversion circuit 18 and converted into 8-bit signals, for example. It is applied to the data bus 7 as a parallel signal. This digital signal is applied to either image memory 8a or 8b connected to data bus 7.

From the image memory, which has completed storing the digital video signal for one screen among the images, memories 8εt, and 8b, the digital video signal is sent to one D/A conversion circuit via the data bus 7. It will be done. This digital video signal is D
/ It is converted into an analog signal by one A conversion circuit and output to the output terminal T1.

Writing of digital video signals to the image memories 8a and 81:+ is performed to either one of the image memories,
At this time, one of the other images and the digital video signal stored in the memory is provided to one D/A conversion circuit. When the writing operation of the digital video signal to the one image memory is completed, that is, when the writing of the digital video signal for one screen is completed, one D/A conversion circuit is provided with the output of the negative image and memory. You will be able to do it.

At time 2, writing of the digital video signal from the S/P conversion circuit 18 is started in the other image memory. In this way, the outputs of the image memories 8a and 8b are alternately applied to one D/'A conversion circuit, and the still image display that changes at regular intervals is displayed as, for example, CR, T( This can be done using a display device such as a cathode ray tube (cathode ray tube).

The sampling frequency in A/D conversion circuit 1.2 is, for example, 32 KHz. Input terminals TR, TL
The audio signals input from the listener correspond to, for example, speakers on the front right and left sides of the listener. Furthermore, two channels are assigned to the video signal input from the input terminal TV. Correspondingly, in the changeover switch 5, its output terminal 54 and input terminals 51, 5
2.53 are sequentially connected.

The switching operation in the changeover switch 5 is carried out in response to a sampling signal having the above-mentioned frequency, for example, and the input terminal 51 is selected during one quarter period of one period of this sampling signal. The input terminal 52 is selected during a period of <1.74 cycles, and the input terminal 53 is selected during the subsequent half cycle, and conduction is established between the input terminal 53 and the output terminal 54. In this way, the recording signal processing unit 1
1, a 12×4 bit digital signal is input.

Since the image memory 8a must store a digital video signal corresponding to one screen worth of still video, for example, the period of one field, that is, 1/60 s.
It must be possible to store the output of the A/D conversion circuit 3 during the period ec. Therefore the image, memory 8a
The storage capacity is 14.3 (MHz) x 8 (beep))
Xi/60 (sec) 1.911 (M bit)
...(1).

Further, the digital video signal read out from the image memory 8a to the recording signal processing section 11 has a frequency of 20 32 (KHz) x 12 (bits) x 2 = 768 (k) per 1 sec.
bit/5ea) -(2)
It is. Therefore, in order for the digital video signal for one screen to be read out to the recording signal processing section 11, it is necessary to
(M bits)/768(k bits)-/sec)=
2.49 (sec) ...(
3) time is required. Writing one screen worth of digital video signals to the image memory 8a takes 1/6 Qsec.
, the magnetic tape 12 requires approximately 2.5 hours.
A digital video signal representing one screen of still video is recorded in a time of sec. Therefore, by reproducing the magnetic tape 12 on which such digital video signals and digital audio signals have been recorded, it is possible to not only convert the audio signals into audio but also display still images that change every 2.5 seconds. can.

By the way, in the above playback operation, the position of the magnetic tape 12 (the position where the recording/playback head corresponds to the magnetic tape 12) is, for example, the number of pages N as shown by the symbol a in FIG.
If the position is in the middle of the video signal recording area S3+S4, the identification code ID11 is used in the back data of the sub signal to be reproduced. In addition, since the still image video signal of page number N-1 has already been reproduced, at this time, N
- One page of still images is displayed.

At this time, when a command to temporarily stop the reproduction operation is given to the reproduction signal processing section 13 from the outside, the reproduction signal processing section 13 changes the identification code ID1 from 1 to 0, and changes the identification code ID2 from 1 to 0. 0, that is, the recording/reproducing head moves the magnetic tape to the device corresponding to the area S2 where the video signal is not recorded immediately before the start position of the video j3 recording area S3+84 of the page number N already shown in FIG. 3. A command to rewind is output, and the rewind is stopped after reaching point b.

When the playback operation is started from the above-mentioned temporarily stopped state where the still image of page N-1 is still displayed, the playback position shifts from point b to direction l\ shown by symbol C in Fig. 3. Then, the video signal recording area S3+84 of page number N is reproduced from the beginning. In other words, even if you temporarily stop the playback operation while the still image of page N-1 is being displayed and then restart playback, the still image of page N will not be missing after the still image of page N-1. Displayed correctly.

On the other hand, when the recording operation is started from the above-mentioned stopped state, the recording device also moves from point b in the (direction).
A new video signal is overwritten from the beginning of the video signal recording area S3+84 of page number N. That is, the video signals up to page N-1 remain in a complete form without any loss for one screen, and the video signals after page N are rewritten with new video signals. Therefore, even if the video signal with the number of pages N is reproduced, one new screen worth of still images will be displayed.

By the way, in conventional recording/playback devices, even when the playback position is at point a, it is temporarily stopped at that point, so when the playback operation is restarted next time, the playback starts from point a in the direction indicated by the sign (l). The playback position shifts, and of the video signal recording area S3+34 on page N, only the video signal in the area indicated by code D1111 is correctly played back. Furthermore, even if recording is started from point a, part of the video signal for page N, that is, the video signal in the area indicated by the code DNA, will not be rewritten and will remain. An incomplete still image will be played.

Note that when the playback position is, for example, in an area S5 indicated by reference numeral a1 in FIG. 3 where no video signal is recorded, when a command to stop is given at 6, the stop is immediately performed at that point. The next reproduction or recording starts from that point a1. Even in this case, there will be no omissions in the reproduced still image, and no incomplete video signal will be recorded.

Effects of the Invention As described above, according to the recording and reproducing apparatus of the present invention, when the reproducing position of the recording and reproducing head when reproduction is temporarily stopped is in the middle of the recording area of one screen's worth of still image information, , the magnetic tape is rewound until the recording/playback end corresponds to the area immediately before the beginning of the still image information recording area where no still image information is recorded, and then stopped, so the next playback operation Alternatively, a still image without any omissions can be reproduced and displayed when the recording operation is started, and it is possible to prevent still image information from being recorded in an incomplete form.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a recording and reproducing device that is an embodiment of the present invention, and FIG. 2 is a schematic diagram of a portion of a magnetic tape on which digital video signals are recorded by the recording and reproducing device. FIG. 3 is an explanatory diagram showing the correspondence between the recording area of the magnetic tape and the identification codes IDI and ID2 of the back data. 1.2.6... A/D conversion circuit, 5, 15... Changeover switch, 8a, 8b... Image memory, 9... P/
S conversion circuit, 11... recording signal processing section, 12-... magnetic tape, 13... reproduction signal processing section, 16, 17.1
9...D/A conversion circuit, 18...S/Pg: conversion circuit, TRTL, TV...input terminal, TRI, TLI, T
VI...output terminal

Claims (1)

[Claims] In a recording and reproducing device that records and reproduces still image information as a digital signal using a magnetic tape, it is determined whether each area of the magnetic tape is an area where still image information is recorded. means for recording a sub-signal on a magnetic tape during recording; and during playback, based on the sub-signal to be reproduced, the playback position of a recording/playback head is set to a position in the middle of a recording area of still image information for one screen on the magnetic tape. and a means for determining whether or not the still image information is located within the recording area of the still image information for one screen when the playback position of the recording/playback head is in the middle of the recording area of the still image information for one screen when the playback is temporarily stopped. 1. A recording/reproducing apparatus comprising: means for rewinding and stopping a magnetic tape until a recording/reproducing head corresponds to an area where still image information is not recorded immediately before the beginning of the recording area.