JPH0824362B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention uses a DAT (Digital Audio Tape recorder), which is a digital magnetic recording / reproducing device for audio signals, to record video signals in addition to audio signals. The present invention relates to a reproducible magnetic recording / reproducing device.

[Prior Art] DAT (Digital Audio Tap), which is under development recently.
e recorders) have attracted attention because they can be downsized and can record / reproduce high-quality audio signals.

On the other hand, the television system of Japan is once every 1/30 second.
It is a method of sending a screen, and the scanning lines are 525 lines, of which about 480 are actually effective scanning lines. In addition, the current television signal is sent by 1/2 screen every 1/60 seconds.
Therefore, in order to display a television image on a dot matrix liquid crystal display panel, 240 scanning line electrodes are required, and the aspect ratio of the television screen is 3: 4, which is required. The number of display dots is 240 × 320.

However, in a small liquid crystal display panel used for a pocketable television receiver, it is difficult to set the number of display dots to 240 × 320.

Therefore, in a small liquid crystal display panel for a pocketable television receiver, for example, half the number of dots,
A television image is displayed with 120 × 160 dots, and even with this number of dots, a sufficiently satisfactory image can be displayed if the screen size is about 3 inches.

Since such a pocketable liquid crystal television receiver is excellent in portability, it is possible to obtain necessary information from television broadcasting at any place.

On the other hand, it is not the time when TV broadcasting was decided,
There is also a desire to watch at any time, and the spread of home VTRs (video tape recorders) that make this possible is almost remarkable. This kind of VTR has a technical goal of recording and reproducing at the highest resolution possible.
Therefore, the current situation is that the circuit becomes complicated and the device becomes large. However, when the video information including television broadcasting is captured from the viewpoint of merely collecting information, it can be said that it is sufficient to obtain the minimum necessary resolution. From this viewpoint, the small liquid crystal television receiver described above was born. Is.

[Object of the Invention] The present invention has been made in view of the above circumstances, and uses a DAT that is being developed as a dedicated device for recording and reproducing audio signals to record and reproduce video signals by mode switching. Provided is a magnetic recording / reproducing device capable of displaying a television video signal as a liquid crystal by integrating a small liquid crystal display panel for a portable liquid crystal television receiver into the device. The purpose is to do.

[Summary of the Invention] A first invention is a DAT format having a track inclined at a certain angle and configured to record a digitally converted audio signal in an audio recording area of each track, and is arranged to face a rotating drum. A magnetic recording / reproducing apparatus which records an audio signal on a magnetic tape by the rotating head and reproduces the recorded audio signal by the rotating head. The memory means and the second memory means are alternately written every one rotation cycle of the rotary drum, and the second storage means and the first memory means are used to write once every one rotation cycle of the rotary drum. Recording means for reading the stored contents on the magnetic tape in the track shape by the rotary head, and the rotary head. A digital audio signal reproduced from the magnetic tape by a recording medium is alternately written into the first storage means and the second storage means at each cycle of one rotation of the rotary drum, and the second storage means. In a magnetic recording / reproducing apparatus having a reproducing means for reading out the stored contents from the first storing means for each rotation cycle of the rotary drum, a mode for selectively switching between an audio mode and a video mode. Switching means, format conversion means for converting the input video signal into digital data, and compressing and converting the digitally converted video signal into a signal amount recorded in the audio recording area of the DAT format, and format conversion means Format reverse conversion means for inputting a video signal and expanding and converting so as to restore the video signal before conversion by the format conversion means When the video mode recording is set by the mode switching means, the digital video signal compressed and converted by the format converting means is supplied to the recording means in place of the audio signal, and the rotary head makes the magnetic tape track shape of the audio mode. A video signal is recorded in the same shape as the above, and when the video mode reproduction is set by the mode switching means, the digital video signal reproduced by the reproducing means is supplied to the format reverse converting means to expand the video signal before compression conversion. A magnetic recording / reproducing apparatus comprising: a control unit that outputs a converted video signal.

A second aspect of the present invention is a DAT format having a track inclined at a constant angle and configured to record a digitally converted audio signal in an audio recording area of each track. The rotary head is arranged to face a rotary drum. A magnetic recording / reproducing apparatus for recording an audio signal on a magnetic tape by using the magnetic head and reproducing the recorded audio signal by the rotary head. The two storage means are alternately written every cycle of one rotation of the rotary drum, and the stored contents are read from the second storage means and the first storage means every cycle of one rotation of the rotary drum. Recording means for reading and recording a digital audio signal on the magnetic tape in the track shape by the rotary head;
The digital audio signal reproduced from the magnetic tape by the rotary head is transferred to the first storage means and the second storage means.
And the memory contents are read from the second memory means and the first memory means every cycle of one rotation of the rotary drum. In a magnetic recording / reproducing apparatus provided with a reproducing means for outputting, a mode switching means for selectively switching between an audio mode and a video mode, and an N × M dot matrix constitution which is significantly smaller than the number of scanning line dots of a standard television video signal. Liquid crystal display panel and the input TV video signal are compressed into N scanning line signals per field, M signals of each scanning line are sampled and converted into digital data, and the digitally converted video signal is converted. Format conversion means for performing digital compression conversion so as to correspond to the signal amount recorded in the audio recording area of the DAT format; Enter the Levi video signal, back to the previous digital compression conversion at the format conversion means,
A format reverse conversion means for outputting the digital data is provided, and when the video mode recording is set by the mode switching means, the digital television video signal digitally compressed and converted by the format conversion means is replaced with the audio signal and is recorded by the recording means. The video signal is supplied and the video signal is recorded on the magnetic tape in the same shape as the track shape of the audio mode by the rotary head, and the digital television video signal reproduced by the reproducing means is set when the video mode reproduction is set by the mode switching means. And a control means for supplying the digital data to the liquid crystal display panel and supplying the digital data to the liquid crystal display panel and supplying the digital data to the format reverse conversion means before digital compression conversion. .

Therefore, a DAT that is a dedicated audio signal recording / playback device
On the other hand, by switching the mode, it becomes possible to record and reproduce the video signal as well, so that the device can be downsized and the circuit can be simplified.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. First, the external structure of a magnetic recording / reproducing apparatus with a liquid crystal display panel according to the present invention will be described with reference to FIG. 10 in FIG.
Is a case body. On the front side of the case body 10, a 120 × 160 dot liquid crystal display panel 11 is provided on the left side in the figure, and a DAT cassette holder 12 is provided on the right side. Further, inside the case body 10, a rotary head system DAT such as a drum or a loading mechanism is provided at a position corresponding to the DAT cassette holder 12.
A mechanical unit (not shown) is provided. Then, the DAT tape cassette 13 is mounted on the DAT cassette holder 12. The size of this DAT tape cassette 13 is 73 × 53 × 10.
It is 5mm and contains 3.81mm wide DAT tape 14 inside the sled. Further, on the front surface of the case body 10, an L channel speaker 15a is arranged on the left side in the figure, and an R channel speaker 15b is arranged on the right side, and TV tuning keys 16a, 16b, VHF and UHF are arranged on the lower side of the liquid crystal display panel 11. A channel display unit 17 is provided, and a DAT operation key 18 for reproducing, recording, fast-forwarding, rewinding, stopping, etc. is provided below the DAT cassette holder 12. Further, a rod antenna 19 is mounted and an antenna housing groove 20 is formed on the upper part of the case body 10. The rod antenna 19 is housed in the antenna housing groove 20 when not in use. Furthermore, on one side of the case body 10, a volume control volume 21,
Mode switch 2 to specify the operating mode of VHF, UHF, OFF
2, DAT mode selector switch 23, DAT line input terminal 2
4, headphone terminal 25 is provided. The DAT mode selector switch 23 is used for recording an external audio input to the DAT tape 14 or for reproducing an audio signal from the DAT tape 14 in the audio mode A and for recording or reproducing an image selected on the DAT tape 14 on the television. This is a switch for switching between the video mode V and the video mode V when performing.

Next, the configuration of the electronic circuit provided in the case body 10 will be described. In FIG. 2, reference numeral 31 is a television signal receiving system, which selects and amplifies the radio wave of an arbitrary TV station selected by the TV tuning keys 16a and 16b from the TV broadcast waves received by the rod antenna 19.
After that, the video signal TVV, the audio signal TVA, and the synchronization signal TVS are separated and output. And the above-mentioned television signal receiving system
The video signal TVV and the synchronization signal TVS output from 31 are input to the video signal compression circuit 32. This video signal compression circuit 32
Is the clock pulse CK from the master clock generator 33
The video signal is compressed in synchronization with the
TVD is input to the liquid crystal display panel drive circuit 35 together with the synchronizing signal TVS from the television signal receiving system 31 via the changeover switches 34b and 34c. The changeover switches 34b and 34c and the changeover switch 34a described later are the mode switches 2 in FIG.
It switches in conjunction with the operation of 2, the mode switch 22 is VHF,
Switches to the upper contact when the UHF TV reception mode is specified, and to the lower contact when the above TV reception mode is turned off. Then, the liquid crystal display panel drive circuit 35
Drives the liquid crystal display panel 11 for display according to the input signal. Further, the audio signal TVS and the synchronizing signal TVS output from the television signal receiving system 31 are input to the video format converter 36 together with the compression signal TVD output from the video signal compression circuit 32. An audio format converter 37 receives the L channel audio signal S _L from the L channel input terminal 24a and the R channel audio signal SR from the R channel input terminal 24b of the DAT line input terminals 24, respectively. It The audio format converter 37 outputs the audio signal S
Amplifies L and SR and converts the format in synchronization with the clock pulse CK from the master clock generator 33,
It outputs a 16-bit PCM audio signal SA, audio RAM write control signal RWA, and DAT sync signal RSW. The DAT synchronization signal RSW is input to the video format converter 36, the recording / playback system 38, the video format inverse converter 39, and the audio format inverse converter 40. The format-converted video signal SV output from the video format converter 36 and the audio signal SA output from the audio format converter 37 are changed over by a changeover switch.
It is selected by 41a and sent to the recording / playback system 38. The video loading control signal RWV output from the video format converter 36 and the audio RAM write control signal RWA output from the audio format converter 37 are selected by the changeover switch 41b and sent to the recording / reproducing system 38. To be In addition, the video format inverse converter
The video RAM read control signal RRV output from 39 and the audio RAM read control signal RRA output from the audio format inverse converter 40 are selected by the changeover switch 41d and sent to the recording / reproducing system 38. This recording / playback system 38 has an internal RAM as described later in detail.
And stores the data sent from the audio format converter 37 or the video format converter 36 in the RAM. And the R of the recording / playback system 38
The data read from the AM is selected by the changeover switch 41c, and is reproduced by the video format reverse converter 39.
As PV or audio format inverse converter 40
Sent as playback audio data PA. The changeover switches 41a to 41d are changed over in conjunction with the operation of the DAT mode changeover switch 23 shown in FIG. 1. When the audio mode A is designated, the upper contact is made, and when the video mode V is designated, the lower contact is made. It is supposed to be replaced. Then, the video format inverse converter 39 inversely converts the reproduced video data PV read from the recording / reproducing system 38 into a normal video format, and the TV audio signal TVA ', TV compressed signal TVD', and TV sync signal TVV. ′ Is output. The TV compression signal TVD 'and the TV synchronization signal TVS' output from the video format inverse converter 39 are sent to the liquid crystal display panel drive circuit 35 via the changeover switches 34b and 34c, respectively, and the TV audio signal TVA 'is changed over. Changeover switch 42 via switch 34a
It is input to one of the fixed contacts of a and 42b. The other fixed contacts of the changeover switches 42 and 42b are connected to the audio signals SL 'and S output from the audio format inverse converter 40.
R'is entered. The changeover switches 42a and 42b are changed over in conjunction with the operation of the DAT mode changeover switch 23. When the video mode V is designated, the upper contact,
When PCM audio mode A is specified, it switches to the lower contact. The signal selected by the changeover switches 42a and 42b is sent to the speaker 15 via the amplifiers 43a and 43b, respectively.
Input to a, 15b and the headphone terminal 25.

Next, details of each part in FIG. 2 will be described. First, referring to FIG. 3, an audio format converter
The circuit configuration of 37 will be described. Line input terminal 2 for DAT
Reference numeral 4 includes an input terminal 24a to which the L channel audio signal SL is input and an input terminal 24b to which the R channel audio signal SR is input. The audio signals SL and SR input to the input terminals 24a and 24b are the switch circuit 371. Are alternately selected by and are sent to the A / D converter 372. Also 37
Reference numeral 3 denotes an audio recording control circuit, which operates with the clock pulse CK sent from the master clock generator 33 as a reference, for example, generates a switching signal SW of 48 KHz to control switching of the switch circuit 371, and a sampling signal of 48 KHz. Generates SP to control the operation of A / D converter 372. The A / D converter 372 performs A / D conversion in synchronization with the sampling signal SA from the audio recording control circuit 373 and outputs a 16-bit digital signal SA.
This digital signal SA has a 16-bit structure, and alternates between L channel and R channel signals, that is, L ₀ R ₀ L ₁ R ₁
Output like .... In addition, the audio recording control circuit 373 is provided with an audio RAM write control signal RWA.
And DAT sync signal RSW.

FIG. 4 shows the circuit configuration of the video format converter 36. In FIG. 4, 361 is a video writing control circuit to which the TV synchronizing signal TVS sent from the television signal receiving system 31 is input. The video writing control circuit 361
Generates various timing signals based on the TV synchronization signal TVS, a sampling clock φ _WA in the A / D converter 362 and a write clock φ in the FI / FO type first buffer 363.
_WA and read clock φ _RA , select signal SEL in selector 364, write clock φ in second FI / FO type buffer 365
Give _WV . The A / D converter 362 converts the TV audio signal TVA sent from the TV signal receiving system 31 into a digital signal VAD and inputs it to the first buffer 363. The first buffer 363 reads the digital audio signal VAD in synchronization with the write clock φ _WA from the video write control circuit 361 and outputs it to the selector 364 in synchronization with the read clock φ _RA . Further, the selector 364 receives the compression signal TVD sent from the video signal compression circuit 32 and the synchronization signal S output from the synchronization pattern generation circuit 366.
YN is input. The selector 364 sequentially selects each input by the select signal SEL from the video writing control circuit 361, and outputs the signal VI including the audio signal VAO, the synchronization signal SYN, and the compression signal TVD as one block to the second buffer 365. .
In addition, the second buffer 365 is a video sending control circuit 3
The held data, that is, the television signal SV is output in synchronization with the read clock φ _RV from 67. This TV signal SV
Is sent to the recording / reproducing system 38 via the changeover switch 41a. Further, the video feed-out control circuit 367 outputs the video RAM write control signal RWV according to the DAT synchronization signal RSW from the audio format converter 37. The video RAM write control signal RWV is sent to the recording / reproducing system 38 via the changeover switch 41b.

FIG. 5 shows the details of the recording / reproducing system 38 in FIG. The PCM signal sent from the outside to the record terminal REC IN is sent to the first RAM 38 via the switch circuit 381.
2, input to the second RAM383. This first RAM382 and second RAM3
83, Used as interleave processing, redundancy addition, delay buffer for tape writing. A write control signal RW externally input to the RW terminal is given to the first RAM 382 and the second RAM 383 via the switch circuit 384. The switch circuits 381 and 384 are connected to the first RAM 38 by the DAT sync signal RSW sent from the audio format converter 37.
2 and the second RAM 383 are alternately switched and connected. Also, the above DA
The T sync signal RSW is sent to the tape write timing generator 385. This tape writing timing generator 385 is
A data read control signal DR is generated according to the DAT synchronization signal RSW and output to the RAMs 382 and 383 via the switch circuit 386. The switch circuit 386 is switching-controlled by the DAT synchronization signal RSW, and a RAM read signal from the timing generator 385.
RR is alternately given to the first RAM 382 and the second RAM 383. RAM38 above
The data read from ₂ , 383 is input to the C ₂ parity generator 388 via the switch circuit 387 which is switched by the DAT synchronization signal RSW. This C ₂ parity generator 388 is
For example, the horizontal parity C ₂ of 48 blocks is added to each of the PCM signals of 82 and 383 and output. This C ₂ Parity Generator 388
And the data read from the RAMs 382 and 383 through the switch circuit 387 are input to the C ₁ parity generator 3810 through the switch circuit 389 which is switched and controlled by the mode A / V of the DAT mode changeover switch 23. To be done. This C ₁ parity generator 3810 is a 32-bit vertical parity C ₁
Is added and output to the modulation circuit 3811. This modulation circuit 3811
After converting the input signal into a signal having a spectrum suitable for magnetic recording by, for example, the NRZI method, the amplifier 3812
Output to the recording / reproducing head unit 3813 via. The recording / reproducing head unit 3813 includes two heads A and B, and is mounted on the rotary drum 3814 at an interval of 180 ° as shown in FIG. 6 (a). Then, the DAT tape 14 is obliquely wound around the rotating drum 3814 in an angle range of 90 °,
It is driven and driven at a constant speed. Therefore, on the DAT tape 14, recording tracks inclined at a constant angle are alternately formed corresponding to the two heads A and B.

Then, the data read from the DAT tape 14 by the recording / reproducing head unit 3813 is amplified by the amplifier 3815 and then sent to the demodulation circuit 3816 to be demodulated. The data demodulated by this demodulation circuit 3816 is the C ₁ parity decoder 38
17 and the timing generator 3818. The C ₂ parity decoder 3817 decodes the C ₁ parity, performs error correction, and outputs the C ₁ parity to the C ₂ parity decoder 3819. And this C ₂
Decoding output of parity decoder 3819 and C ₁ parity decoder 38
The decoded output of 17 is selected by the switch circuit 3820 that is switched by the switching signal A / V from the DAT mode selection switch 23, and is further switched through the switch circuit 3821 that is switched by the DAT synchronization signal RSW to the third RAM 3822 or the fourth RAM 3823.
Is input from. On the other hand, the timing generator 3818 is
A data write control signal DW is generated according to the T synchronization signal RSW, and is output to the third RAM 3822 and the fourth RAM 3823 via the switch circuit 3824 which is switch-controlled by the DAT synchronization signal RSW. Also, it is given from the outside to the third RAM3822 and the fourth RAM3823.
The RAM read control signal RR is input via the switch circuit 3825 which is switch-controlled by the DAT synchronization signal RSW. Then, the data read from the third RAM 3822 and the fourth RAM 3823 is
Switch circuit 38 controlled by DAT sync signal RSW
It is output as playback output PLAY OUT via 26.

FIG. 7 shows the configuration of the audio format inverse converter 40 in FIG. 401 in FIG.
Is a D / A converter, which is a playback audio signal PA sent from the recording / playback system 38 via the selector switch 41c.
Is converted into a digital signal and selectively output to the amplifiers 403 and 404 via the switch circuit 402. An audio reproduction control circuit 405 receives the clock pulse CK from the master clock generator 33 and the DAT synchronization signal RSW from the audio format converter 37. The audio reproduction control circuit 405 outputs the audio RAM read control signal RRA to the outside according to the input signal, and outputs the switching signal SWP to the switch circuit 402. The switch circuit 402 performs a switching operation according to the switching signal SWP and outputs the output signal of the D / A converter 401 to the amplifier 403.
Alternatively, it outputs to the amplifier 404. Then, the output signal of the amplifier 403 is output as the left channel reproduced audio signal SL ′, and the output signal of the amplifier 404 is output as the right channel audio signal SR ′.

FIG. 8 shows details of the video format inverse converter 39. The TV playback signal PV sent from the recording / playback system 38 to the video format inverse converter 39 via the changeover switch 41c is a sync detector 391, a video buffer 392,
The DAT sync signal RSW from the audio format converter 37 is input to the audio buffer 393, and is input to the video capture control circuit 394 and the video timing creation circuit 395. The sync detector 391 detects the sync signal in the TV reproduction signal PV and outputs the detection signal SD to the video capture control circuit 39.
4 and the video timing generation circuit 395. The video capture control circuit 394 outputs the video RAM read control signal RRV to the outside in accordance with the input signals, and also outputs the write control signals VBC and ABC to the video buffer 392 and the audio buffer 393, respectively. Also, the video timing creation circuit 395
Is an externally input DAT sync signal RSW and sync detector 391
A timing signal is created in accordance with the sync detection signal SV input from, and the read control signals VBR and ABR are output to the video buffer 392 and audio buffer 393, respectively, and the sync signal is generated.
Output TVS ′ to the outside. Then, the video buffer 392
Captures the video signal in the TV playback signal PV sent from the recording / playback system 38 according to the control signal VBC from the video capture control circuit 394, and outputs the stored data according to the control signal VBR from the video timing creation circuit 395. To do. The output signal of the video buffer 392 is output to the outside as a television brightness signal TVD '. Also, voice buffer 3
93 receives the audio signal in the TV reproduction signal PV according to the control signal ABC from the video acquisition control circuit 394, and stores the held data in the read signal ABR from the video timing generation circuit 395.
Output according to. The audio signal read from the audio buffer 393 is converted into an analog audio signal TVA ′ by the D / A converter 396 and output to the outside.

 Next, the operation of the above embodiment will be described.

First, the case of recording an externally input audio signal will be described. When recording an audio signal,
Turn off the mode switch 22 in FIG.
Switch the mode selector switch 23 to audio mode A,
Input an audio signal (stereo) from the outside to the DAT line input terminal 24. By switching the DAT mode selector switch 23 to the audio mode A side as described above,
The change-over switches 41a and 41b in FIG. 2 are placed on the audio format converter 37 side, and the change-over switches 41c and 41d.
Is switched and connected to the audio format reverse converter 40 side, and further the changeover switches 42a and 42b are switched and connected to the audio format reverse converter 40 side. In this state, after mounting the DAT tape cassette 13 on the DAT cassette holder 12,
The recording operation is started by simultaneously operating the REC key and the PLAY key of the AT operation keys 18. And above
The audio signal input to the DAT line is the left channel audio signal SL and the right channel audio signal.
It consists of SR and is sent to the audio format converter 37 in FIG. This audio format converter
As shown in FIG. 3, 37 is an A / D converter which alternately selects externally input audio signals SL and SR by a switch circuit 371.
Input converter 372. The switch circuit 371 is switching-controlled by a switch signal SW output from the audio recording control circuit 373. Switch signal SW above
Is a rectangular wave signal that is set to the same sampling frequency of the A / D converter 372, for example 48 KHz, and has a duty factor of 50%, as shown in FIG. 9 (a). Audio signal SL
Is selected, and when the level is low, the switch circuit 371 is switched and controlled so as to select the audio signal SR of the right channel.

On the other hand, the A / D converter 372 uses the 48 KHz sampling signal SP supplied from the audio recording control circuit 373.
The audio signal is sampled by and converted into a 16-bit PCM signal per word. Figure 9 (b) shows the A / D
It shows the output signal SA of the converter 372, L ₀ , L ₁ ,
L ₂ ... Represents 1 word of the left channel PCM audio signal, and R ₀ , R ₁ , ... Represents 1 word of the right channel audio PCM signal, respectively. The PCM audio signal SA output from the A / D converter 372 is sent to the recording / reproducing system 38 via the changeover switch 41a in FIG. Further, the audio format converter 37 outputs an audio RAM write control signal RWA including a RAM address signal and a timing signal in synchronization with the switch signal SW, and at the same time for each cycle of the audio RAM write control signal RWA. Generates a DAT sync signal RSW that inverts low / high. The RAM write control signal RW _A via the changeover switch 41b, also, DAT synchronizing signal RSW is sent directly to the recording and reproducing system 38.

The recording / playback system 38, which is shown in detail in FIG. 5, includes a PCM audio signal S from the audio format converter 37.
When A and DAT sync signal RSW are sent, DAT sync signal RS
The switch circuits 381 and 384 are switched by W, and the PCM audio signal SA is written in the first RAM 382 and the second RAM 383 alternately.
That is, as shown in FIGS. 9 (c) (d) (e), DAT
In the TA section where the sync signal RSW becomes low level, the second RAM 383
The PCM audio signal SA is written and the PCM audio signal SA is written in the first RAM 382 in the TB section in which the DAT synchronization signal RSW is at high level. The RAMs 382 and 383 have a capacity of 256 (bits) x 256 (blocks) = 65536 (bits). And the period shown in FIG.
T _A and T _B are 60/2000 “sec”, so the number of audio signal samples included in this section is 48K × (60/2000) × 2 (CH) = 2880 “word” = 2880 × 16 = 46080 "bits". That is, as shown in FIG. 9 (b), 1440 words of left channel PCM audio signals L0 to L1439,
The right channel PCM audio signals R0 to R1439 are 1440 words in total, which is 2880 words, and one word is 16 bits, which is 46080 bits.

On the other hand, the data read control signal DR is output from the tape write timing generator 385 in synchronization with the DAT synchronization signal RSW and sent to the RAMs 382 and 383 via the switch circuit 386.
In this case, the switch circuit 386 is switched by the DAT synchronization signal RSW and connected to the first RAM 382 and the second RAM 383, but is switched to a state opposite to the switch circuits 381 and 384. Therefore, in the TA section in which the DAT synchronization signal RSW becomes low level, the first R
The PCM audio signal SA is read from the AM382 and the DAT sync signal RSW is at the high level.
The audio signal SA is read. Then, the first RAM38
2, PCM audio signal SA read from the second RAM383,
As shown in FIG. 10 (a), a C ₂ parity generator 388 adds 48 blocks of C ₂ parity (horizontal parity) to an audio signal of 208 blocks, and further a C ₁ parity generator.
32-bit C for 224-bit audio signal on 3810
₁ parity (vertical parity) is added. When the audio mode A is designated by the DAT mode selector switch 23, the switch circuit 389 connects the C ₂ parity generator 388 and the C ₁ parity generator 3810 by the mode signal A / V. Therefore, C ₂ parity and C ₁ parity are added to the PCM audio signal as described above, and then
It is sent to the modulation circuit 3811. In this case, the PCM audio signal input to the modulation circuit 3811 and the C ₂ parity and C ₁ parity are set in the following relationship. That is, the audio area set in the first RAM 382 and the second RAM 383 is 224 (bits) x 104 (blocks) x 2 = 46592 (bits), but the audio signal of "46080 bits" described above is written in this audio area. Get caught. Therefore, 512 bits are unused space in the audio area. The C ₂ parity added to the PCM audio signal is 224 (bits) x 48 (blocks) = 10752 (bits), and the C ₁ parity added to the PCM audio signal and C ₂ parity is Is 32 (bits) x 256 (blocks) = 8192 (bits).

The modulation circuit 3811 converts the PCM audio signal to which the C ₁ and C ₂ parity is added as described above into a signal having a spectrum suitable for magnetic recording, and then outputs the signal to the recording / reproducing head unit 3813. Record on DAT tape 14.

When reproducing the PCM audio signal recorded on the DAT tape 14, the PLAY key of the DAT operation keys 18 is operated. By operating this PLAY key, DAT tape 1
The recording signal of 4 is read by the recording / reproducing head unit 3813 and sent to the demodulation circuit 3816 via the amplifier 3815. The demodulation circuit 3816 demodulates the reproduction signal and outputs it to the C ₁ parity decoder 3817 and the timing generator 3818. The timing generator 3818 is a demodulation signal from the demodulation circuit 3816 and a DAT synchronization signal R from the audio format converter 37.
The data write control signal DW is generated by the SW and is alternately output to the third RAM 3822 and the fourth RAM 3823 via the switch circuit 3824.

On the other hand, in the audio mode A, the mode signal
Since the switch circuit 3820 is switched to the C ₂ parity decoder 3819 side by the A / V, the demodulated signal output from the demodulation circuit 3816 is the C ₁ parity decoder 3817, and the C ₁ parity signal is decoded. C ₂ parity is decoded by C ₂ parity decoder 3819. Also, the C ₁ parity decoder 3817 and C ₂
The parity decoder 3819 detects an error in the reproduced PCM audio signal by the decoded C ₁ and C ₂ parity,
Correct the error. And the error-corrected playback
The PCM audio signal is output through the switch circuits 3820 and 3821, and T _C and T are synchronized with the data write control signal DW output from the timing generator 3818 as shown in FIGS. 3rd RAM3822 or 4th RAM3823 during period _D
Are written alternately. The PCM audio signals stored in the third RAM 3822 and the fourth RAM 3823 are read by the audio read control signal RRA sent from the audio format inverse converter 40, and alternately selected by the switch circuit 3826 and output. That is, the switch circuit 38
26 is the 4th RAM3823 in the period T _C due to the DAT synchronization signal RSW.
On the other hand, in the period T _D , it is switched to the side of the third RAM 3822, so that the RAM which is not in the written state is always in the read state, and the PCM audio signal is read from the fourth RAM 3823 during the period T _C and from the third RAM 3822 during the period T _D. In this case, by the interleaving process at the time of recording-the data words dispersed in the segment are returned to the original array by controlling the read addresses to the third RAM 3822 and the fourth RAM 3823 at the time of reproduction. Be done. Then, the PCM audio signal alternately output from the third RAM 3822 and the fourth RAM 3823 becomes a reproduction output, and is sent from the recording / reproducing system 38 to the audio format inverse converter 40 via the changeover switch 41c.

As shown in FIG. 7, the audio format inverse converter 40 generates an audio RAM read control signal RRA by the DAT sync signal RSW and the clock pulse CK in the audio reproduction control circuit 405 and outputs it to the recording / reproducing system 38. To do. Therefore, P corresponding to the control signal RRA
The CM audio signal PA is read from the recording / playback system 38 and input to the D / A converter 401 of the audio format inverse converter 40. This D / A converter 401 converts the PCM audio signal PA into an analog signal, and a switch circuit
Output to the amplifiers 403 and 404 via 402. The switch circuit 402 is switched by the switching signal SWP given from the audio reproduction control circuit 405, that is, the switching signal SWP of 48 KHz similar to the switching signal at the time of data recording, and the D / A
Amplifiers 403 and 404 for audio signals from converter 401
Input alternately. Then, the signal amplified by the amplifier 403 is output from the audio format inverse converter 40 as the left channel reproduced audio signal SL ′, and the signal amplified by the amplifier 404 is output as the right channel reproduced audio signal SR ′. The audio signal S output from this audio format inverse converter 40
L'and SR 'are sent to the amplifiers 43a and 43b via the changeover switches 42a and 42b in FIG. 2 to drive the speakers 15a and 15b, respectively.

Next, the operation when receiving a television wave from a television broadcasting station will be described. To receive TV signals,
The mode switch 22 in FIG. 1 is switched to VHF or UHF, and the DAT mode selector switch 23 is switched to the video mode V side. By selecting VHF or UHF by the mode switch 22 as described above, the changeover switches 34a to 34c in FIG. 2 are changed over to the television signal receiving system 31 side, and the DAT mode changeover switch 23 is changed over to the video V side. Therefore, the changeover switches 42a, 42b
Are switched to the changeover switch 34a side. Therefore, the video signal TVV output from the television signal receiving system 31 is sent to the video signal compression circuit 32 to be converted into a digital signal and compressed. The video signal compression circuit 32 takes out the video signal TVV sent from the television signal receiving system 31 every other horizontal scanning as shown in FIG. 11, and outputs the selected video signal to the clock from the master clock generator 33. Sampling is performed 160 times by the pulse CK, and each sample is converted into, for example, a 3-bit digital signal. In this case, the number of effective scanning lines per field is 240,
Since it is taken out every other line, it is compressed to 120 horizontal scanning lines per field. Therefore, the TV compressed signal output from the video signal compression circuit 32, that is, the digital luminance signal TVD has a signal amount of 120 × 160 × 3 = 57600 bits per field.

Then, the digital luminance signal TVD compressed by the video signal compression circuit 32 as described above is sent to the liquid crystal display panel drive circuit 35 via the changeover switch 34b and displayed on the liquid crystal display panel 11. On the other hand, TV signal receiving system
The audio signal TVA output from 31 is directly sent to the amplifiers 43a, 43 via the changeover switch 34a and the changeover switches 42a, 42b.
to the speakers 15a, 15b by the amplifiers 43a, 43b.
b is driven. In this state, TV tuning keys 16a, 16
You can select any TV channel by operating b.

Then, when recording the TV image selected by the TV tuning keys 16a and 16b, after mounting the DAT tape cassette 13 in the DAT cassette holder 12, the DAT operation key 18 in the TV receiving state is set. Operate the "REC" and "PLAY" keys at the same time. When recording a television image, a TV audio signal TVA, a synchronizing signal TVS and a video signal compression circuit 32 output from the television signal receiving system 31.
The digital luminance signal TVD output from is sent to the video format converter 36 and converted into a digital signal recordable in the DAT. As shown in detail in FIG. 4, the video format converter 36 inputs the compressed TV digital luminance signal TVD to the selector 364, the TV audio signal TVA to the A / D converter 362, and the synchronization signal TVS to the video writing control circuit 361. To be done. This video writing control circuit 361 is for one screen of the video signal, that is, 30H.
It is synchronized with z, and as shown in Fig. 12 (a), T1, 2, T
Each of the three periods is periodically repeated to generate various timing signals, the details of which will be described later. The A / D converter 362 is used to input the TV audio signal.
The TVA is sampled in synchronization with the 800 Hz clock pulse φ _WA sent from the video writing control circuit 361 and converted into a digital audio signal VAD shown in FIG. 12 (c). The digital audio signal VAD is written in the first buffer 363 in synchronization with the clock pulse φ _WA from the video writing control circuit 361. The digital audio signal VAD stored in the first buffer 363 is synchronized with the clock pulse φ _RA from the video writing control circuit 361, and the signal VAO shown in FIG.
And is input to the selector 364. This selector 364 is a select signal from the video writing control circuit 361.
The input signal, that is, the digital luminance signal TVD shown in FIG. 12 (b), the synchronization pattern SYN from the synchronization pattern generation circuit 366, and the audio signal VAO from the first buffer 363 are sequentially selected by SEL, and the selection is performed as shown in FIG. The composite signal VI shown in () is output.
The sync pattern SYN output from the sync pattern generation circuit 366 is a signal indicating the boundary of one cycle section. Then, the composite signal VI is written in the second buffer 365 in synchronization with the clock pulse φ _WV from the video writing control circuit 361. The data stored in this second buffer 365 is
The image is read out in synchronization with the clock pulse φ _RV from the image sending-out control circuit 367 and sent to the recording / playback system 38 via the changeover switch 41a.

Then, the video writing control circuit 361 operates in the following order in one cycle section, and the selector 364 synthesizes the signal VI shown in FIG. When switching the selector 364 by the select signal SEL, the video writing control circuit 361 first outputs the sync signal SYN from the sync pattern generation circuit 366 to the second buffer 365 from 224 bits (1 block) to 448 bits (2 blocks). Let Next, select the digital luminance signal TVD and select 1/2 screen data "120 (H) x 160 (sample) x 3 (bit)" (258
Block) is output to the second buffer 365. In this case, a 192-bit dummy is added to the data for the 1/2 screen. Then, during the next half cycle, as shown in FIG. 12 (d), the audio signal VAO for one cycle “5600 (bits) / 224 (bits) = 25 (blocks)” is clocked from the first buffer 363. _Read by pulse φ _RA , selector
It is output to the second buffer 365 via 364. Therefore, the data VI shown in FIG. 10 (b) and FIG. 12 (e) is input to the second buffer 365 from the selector 364 and is written in synchronization with the clock pulse φ _WV . The data stored in the second buffer 365 is the video sending control circuit 367.
In response to the clock pulse φ _RV from, the DAT synchronization signal RSW of 16.6 Hz is read in units of 128 blocks and output as recording data SV. This recording data SV is
As shown in FIGS. 12 (f) and 12 (g), first, the DAT synchronization signal R
When SW is low level, 9/10 of the data in T1 cycle, DA
When the T sync signal RSW is at a high level, the remaining 1/10 of the remaining data of the T1 cycle and 8/10 of the T2 cycle, and so on, are read from the second buffer 365 in the cycle sequentially synchronized with the DAT sync signal RSW. . Then, the recording data SV read from the second buffer 365 is sent to the recording / reproducing system 38 via the changeover switch 41a as shown in FIG. At this time, the recording / reproducing system 38
The video RAM write control signal RWV is sent to.

In the recording / reproducing system 38 shown in detail in FIG. 5, when the video recording data SV and the DAT sync signal RSW are sent from the video format converter 36, the switch circuits 381 and 384 are switched by the DAT sync signal RSW. , Recording data SV is 1st R
It is written alternately in AM382 and second RAM383. Ie DAT
When the sync signal RSW is low level, the recording data SV is written in the second RAM 383, and when the DAT sync signal RSW is high level, the recording data SV is written.
Recording data SV is written in 1RAM382. At this time, period T
In _A and T _B, the television signal is written to the 1RAM382, television signal area of the 2RAM383 shown in Figure 10 by the write control signal RW (c). The television signal written in the period T _A or T _B has 224 (bits) × 256 (blocks) = 57344 (bits) (recording rate). Since the period, T _A , T _B is 60/2000 “sec”,
The TV signal rate is 256 x (2000/60) x 1/30 = 256 x 10/9 = 284 + 4/9 (block) per 30 Hz. Then, within 30Hz, as shown in Fig. 10 (b), there are 258 luminance signals and 25 speech signals. When set to 258 + 25 + {(5/9) x 1 + (4/9) x 2} = 284 + 4/9 (block), the recording and signal transmission rates match, and data can be recorded without excess or deficiency.

On the other hand, the data read control signal DR is output from the tape write timing generator 385 in synchronization with the DAT synchronization signal RSW and sent to the first RAMs 382 and 383 via the switch circuit 386. In this case, the switch circuit 386 is switched by the DAT synchronization signal RSW and connected to the first RAM 382 and the second RAM 383, but is switched to a state opposite to the switch circuits 381 and 384. Thus, the T _A section DAT synchronizing signal RSW becomes low level television signal is read from the 1RAM382, DAT synchronization signal
RSW television signal from the 2RAM383 is read at T _B section serving as a high level. When the video mode V is designated by the DAT mode selector switch 23, the switch circuit 389 is connected to the switch circuit 387 by the mode signal A / V, and the input and output terminals of the C ₂ parity generator 388 are short-circuited. It Therefore, the television signal read from the first RAM 382 and the second RAM 383 is a 32-bit C signal with respect to a 224-bit television signal by the C ₁ parity generator 3810 as shown in FIG. 10 (c).
Modulation circuit 3811 with ₁ parity (vertical parity) added
Sent to. The modulation circuit 3811, C ₁ as described above
The television signal to which the parity is added is converted into a signal having a spectrum suitable for magnetic recording, and then output to the recording / reproducing head unit 3813 and recorded on the DAT tape 14.

When reproducing the television signal recorded on the DAT tape 14, the PLAY key of the DAT operation keys 18 is operated. By this operation of the PLAY key, the recording data of the DAT tape 14 is read by the recording / reproducing head unit 3813 and sent to the demodulation circuit 3816 via the amplifier 3815. This demodulation circuit 3816 demodulates the above-mentioned reproduced signal to generate a C ₁ parity decoder 38
17 and the timing generator 3818. The timing generator 3818 creates a data write control signal DW from the demodulated signal from the demodulation circuit 3816 and the DAT synchronization signal RSW from the audio format converter 37, and the switch circuit 3824.
To output to the third RAM 3822 and the fourth RAM 3823 alternately.

On the other hand, in the video mode, since the switch circuit 3820 is switched to the C ₁ parity decoder 3817 side by the mode signal AV, the demodulated signal output from the demodulation circuit 3816 is C ₁ parity decoder 3817. ₁ Parity signal is decoded. Further, the C ₁ parity decoder 3817 detects an error in the reproduced television signal by the demodulated C ₁ parity and corrects the error. The error-corrected reproduced television signal is output via the switch circuits 3820 and 3821, and is synchronized with the data write control signal DW output from the timing generator 3818 in the period of T _C and T _D to the third R
Alternately written to AM3822 or 4th RAM3823. The above
The television signals stored in the 3RAM 3822 and the 4th RAM 3823 are read by the read control signal RRV sent from the video format inverse converter 39, and are alternately selected and output by the switch circuit 3826. That is, the switch circuit 3826
As in the audio mode, the DAT synchronization signal RSW causes the fourth RAM 3823 side in the period T _C and the third RAM 3822 in the period T _D.
The RAM is switched to the side, so that the RAM that is not in the written state is always in the read state, and the television signal is read from the fourth RAM 3823 during the period T _C and the third RAM 3822 during the period T _D. In this case, the data words distributed in one segment due to the interleave processing during recording are the 3rd RAM 3822 and 4R
By controlling the read address to AM3823, the read data is returned to the original array. And the third RAM
The TV signal alternately output from the 3822 and 4th RAM3823 becomes the playback output, and the changeover switch from the recording / playback system 38.
It is sent to the video format inverse converter 39 via 41c.

The video format inverse converter 39 reads out a digitally recorded television signal from the recording / reproducing system 38,
Luminance signal TVD ', TV audio signal TVA', and TV synchronization signal TV
S'is created, and its detailed operation will be described below. The video timing creation circuit 395 in the video format inverse converter 39 is the audio format converter 3
The RAM read control signal RRV for video is generated by the DAT synchronization signal RSW sent from 7, and the record data is taken into the recording / reproducing system 38. The reproduced data at this time is shown in Fig. 12 (h).
As shown in (i). 1 from the input playback data
Sync detector for sync pattern of blocks or 2 blocks
391, and outputs the synchronization detection signal SD to the video capture control circuit 394 and the video timing creation circuit 395. The video capture control circuit 394 outputs the write control signal VBC to the video buffer 392 and writes the reproduction data to the video buffer 392 for 258 blocks after the synchronization detection signal SD falls. Furthermore, the video capture control circuit 394 continues to output the write control signal ABC to the audio buffer 393 for 25 blocks to write the reproduction data in the audio buffer 393. That is, since the reproduced data is recorded in the format shown in FIG. 10B, the video signal of 258 blocks following the sync signal is written in the video buffer 392, and the audio signal of the following 25 blocks is written in the audio buffer 393. Put in.

Further, the video timing creation circuit 395 creates a signal (30 Hz) having a predetermined ratio to the DAT synchronization signal RSW (2000/60 Hz), and creates various television signals in synchronization with this signal.
That is, the video timing generation circuit 395 uses the TV synchronization signal T
VS '(vertical sync signal, horizontal sync signal) is created and the read control signal ABR is synchronized with this TV sync signal TVS'.
And a video luminance signal is read from the video buffer 392 by the signal ABR. In this case, from the video buffer 392, as shown in FIG. 12 (h), the data of 120 × 160 pixels is read in the first half of the 30 Hz period, and the data of the same pixel as the first half is read in the second half of 30 Hz, and the TV luminance signal is read. Output as TVD ′. The audio signal is sampled from the audio buffer 393 every 7 bits, that is, 800 Hz per 30 Hz.
It is read out periodically and converted back to an analog signal by the D / A conversion circuit 396. Then, the signal taken out from the D / A conversion circuit 396 is outputted as the audio signal TVA '.

The TV luminance signal TVD 'output from the video buffer 392 and the synchronization signal TVS' output from the video timing generation circuit 395 are changed over to the changeover switch 34 as shown in FIG.
The video signal is sent to the liquid crystal display panel drive circuit 35 via b and 34c, and the video signal is displayed on the liquid crystal display panel 11. The audio signal TVS ′ output from the D / A conversion circuit 396 is sent to the amplifiers 43a and 43b via the changeover switches 34a and 42a and 42b.
The speakers 15a and 15b are driven by the outputs of the amplifiers 43a and 43b. As described above, the television video signal and the television audio signal are reproduced.

However, the present invention is not limited to the above embodiment, and the television signal receiving system system and the recording / reproducing system system may be combined in various combinations as shown in FIGS. 13 (a) to 13 (f). Can be considered. That is, FIG. 13 (a) shows DA
It is composed of a playback system a for T tape, a video signal playback circuit b, and a liquid crystal display device c, and is configured as a dedicated device for playing back recorded DAT tape. It comprises a compression circuit d for converting and compressing, a video signal recording circuit e, a recording / reproducing system f, a video signal reproducing circuit b, and a liquid crystal display device c, which is configured as an external input recording / reproducing device. FIG. 3C shows a TV tuner g, a compression circuit d, a video signal recording circuit e, a recording / reproducing system f, a video signal reproducing circuit b, an output signal of the compression circuit d or the video signal reproducing circuit b by a manual operation. The recording / playback device is equipped with a liquid crystal television and comprises a changeover switch h for switching and selecting and outputting to the liquid crystal display device c. In the same figure (d), the video signal reproducing circuit b and the liquid crystal display device c are connected to the reproducing system a via the changeover switch i, and the audio reproducing circuit j and the amplifier k are connected to the reproducing system a via the changeover switch i. , A speaker 1 is connected and the device is configured as a recorded DAT tape and a reproduction-only machine for the recorded DAT tape. The same figure (e) is the same figure (b).
, An audio signal recording circuit n is added to the input side of the recording / reproducing system f via a changeover switch m, and an audio signal reproducing circuit j and an amplifier k are added to the output side of the recording / reproducing system f via a changeover switch i. , A speaker 1 is added, and the device is configured as a recording / reproducing device for an externally input video signal / audio signal. In FIG. 6F, the TV tuner g and the externally input video signal are selectively input to the compression circuit d through the changeover switch o in FIG. The radio tuner p and the external audio input are selectively input via the changeover switch q. The compression circuit d and the video signal reproduction circuit b are connected to the liquid crystal display device c via the changeover switch h, and the audio signal reproduction device j and the common terminal of the changeover switch q are amplified via the changeover switch r. connected to k. That is,
In FIG. 13 (f), it is configured as a video signal / audio signal recording / reproducing device with a liquid crystal television. As described above, in the present invention, the television signal receiving system system and the recording / reproducing system system can be configured in various combinations.

In the above embodiment, the television signal is recorded / reproduced in substantially the same format as the audio and the drum rotation is the same as 2000/60 (per minute) rotation, but it may be a special format for video. Further, since the density can be increased by increasing the number of rotations of the drum, a color video signal can be recorded.

[Effects of the Invention] As described in detail above, according to the first invention of the present application, it is possible to record / reproduce a video signal also by switching the mode with a DAT which is a dedicated device for recording / reproducing an audio signal. In particular, since the video recording is performed according to the DAT format at the time of audio recording, the peripheral part of the DAT recording / reproducing system can be shared for the video recording / reproducing, and the overall size of the device can be reduced and the circuit can be simplified. be able to.

Further, according to the second invention of the present application, in addition to the configuration of the first invention, a small liquid crystal display panel for portable equipment is further integrated into the device, and a TV video signal is compressed according to the number of dots of the liquid crystal display panel. Then I tried to record and play. Therefore, not only the video signal can be recorded / reproduced by switching the mode with the DAT which is a recording / reproducing apparatus for the audio signal, but also the reproduction / visual confirmation of the recorded video signal can be realized by the device as a single unit. It will be very useful as a device. Also, since the video signal is compressed and recorded according to the number of display dots on a small liquid crystal display panel for a portable liquid crystal television receiver, conversion to the DAT format can be performed easily and the overall circuit scale has been reduced. A magnetic recording / reproducing device can be provided.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a perspective view showing the external configuration, FIG. 2 is a block diagram showing the overall circuit configuration, and FIG. 3 shows the details of an audio format converter. Block diagram, FIG. 4 is a block diagram showing details of a video format converter, FIG. 5 is a block diagram showing details of a recording / reproducing system, and FIG. 6 (a) is a diagram showing a configuration of a rotary head portion. FIG. 6 (b) is a diagram showing a recording pattern on the magnetic tape, FIG. 7 is a block diagram showing details of the audio format inverse converter, and FIG. 8 is a block diagram showing details of the video format inverse converter. The figure is a timing chart for explaining the recording / reproducing operation of the audio signal, FIG. 10 (a) is a diagram showing the recording format of the audio signal, and FIG. 10 (b) is the table converted by the video format converter. A diagram showing the format of the Levi signal,
FIG. 10 (c) is a diagram showing a recording format of a television signal, FIG. 11 is a diagram for explaining a video signal compression operation in a video signal compression circuit, and FIG. 12 is a diagram for explaining a video signal recording / reproducing operation. FIGS. 13A to 13F are timing charts for the purpose of showing a combination configuration example of a television signal receiving system system and a recording / reproducing system system, respectively. 10 …… Case body, 11 …… LCD display panel, 12 …… DAT
Cassette holder, 13 …… DAT Tape cassette, 14 …… DAT
Tape, 15a, 15b …… Speaker, 16a, 16b …… TV tuning key, 18 …… DAT operation key, 19 …… Rod antenna, 22 …… Mode switch, 23 …… DAT mode selector switch, 24 …… DAT Line input terminal, 31 ... TV signal receiving system, 32 ... video signal compression circuit, 33 ... master clock generator, 34a to 34c, 41a to 41d, 42a, 42b ...
Changeover switch, 35 …… Liquid crystal display panel drive circuit, 36 ……
Video format converter, 37 ... Audio format converter, 38 ... Recording / playback system, 39 ... Video format reverse converter 39, 40 ... Audio format reverse converter, 361 ... Video writing control circuit, 362 ... … A / D converter, 363 …… First buffer, 364 …… Selector, 365
...... Second buffer, 366 ...... Sync pattern generation circuit, 367
...... Video output control circuit, 372 ...... A / D converter, 37
3 …… Audio recording control circuit, 382 …… First RA
M, 383 ... second RAM, 388 ... C ₂ parity generator, 3810 ...
… C ₁ parity generator, 3813 …… Recording / playback head, 38
16 …… Demodulation circuit, 3817 …… C ₁ parity decoder, 3818 ……
Timing generator, 3819 ...... C ₂ parity decoder, 3822 ...
… 3rd RAM, 3823 …… 4th RAM, 391 …… Sync detector 392 ……
Video buffer, 393 ... Audio buffer, 394 ... Video capture control circuit, 395 ... Video timing creation circuit, 396, 40
1 …… D / A converter, 405 …… Audio playback control circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 5/7826

Claims (2)

[Claims] 1. A DAT format having tracks inclined at a constant angle and configured to record a digitally converted audio signal in an audio recording area of each track. A magnetic recording / reproducing apparatus for recording an audio signal on a tape and reproducing the recorded audio signal by the rotary head, wherein the input audio signal is converted into a digital signal, and the first storage means and the second storage means are provided. The memory means and the rotary drum are alternately written every one rotation cycle, and the stored contents are read from the second storage means and the first storage means every one rotation cycle of the rotary drum. Recording means for recording a digital audio signal on the magnetic tape in the track shape by the rotary head; The digital audio signal reproduced from the tape, the said first memory means second
And the memory contents are read from the second memory means and the first memory means every cycle of one rotation of the rotary drum. In a magnetic recording / reproducing apparatus equipped with a reproducing means for outputting, a mode switching means for selectively switching between an audio mode and a video mode, and an input video signal is converted into digital data, and this digitally converted video signal is converted. Format conversion means for compressing and converting into a signal amount recorded in the audio recording area of the DAT format, and inputting the format-converted video signal, and expanding so as to restore the video signal before conversion by the format conversion means Format reverse conversion means for converting, and compression by the format conversion means when the video mode recording is set by the mode switching means The converted digital video signal is supplied to the recording means in place of the audio signal, the rotary head records the video signal in the same shape as the track shape of the audio mode on the magnetic tape, and the video by the mode switching means. And a control means for supplying the digital video signal reproduced by the reproduction means to the format reverse conversion means and outputting the video signal expanded and converted into the video signal before the compression conversion when the mode reproduction is set. Characteristic magnetic recording / reproducing device. 2. A DAT format which has tracks inclined at a constant angle and is configured to record a digitally converted audio signal in an audio recording area of each track. A magnetic recording / reproducing apparatus for recording an audio signal on a tape and reproducing the recorded audio signal by the rotary head, wherein the input audio signal is converted into a digital signal, and the first storage means and the second storage means are provided. The memory means and the rotary drum are alternately written every one rotation cycle, and the stored contents are read from the second storage means and the first storage means every one rotation cycle of the rotary drum. Recording means for recording a digital audio signal on the magnetic tape in the track shape by the rotary head; The digital audio signal reproduced from the tape, the said first memory means second
And the memory contents are read from the second memory means and the first memory means every cycle of one rotation of the rotary drum. In a magnetic recording / reproducing apparatus having a reproducing means for outputting, a mode switching means for selectively switching between an audio mode and a video mode, and an N × M dot matrix constitution which is significantly smaller than the number of scanning line dots of a standard television video signal. Liquid crystal display panel, and the input TV video signal is compressed into N scanning line signals per field, M signals of each scanning line are sampled and converted into digital data, and this digitally converted video signal is converted. Format conversion means for performing digital compression conversion so as to correspond to the signal amount recorded in the audio recording area of the DAT format; A format reverse conversion means for inputting a television video signal, returning it to digital compression conversion by the format conversion means, and outputting the digital data, and converting the format when the video mode recording is set by the mode switching means. The digital television video signal digitally compressed and converted by the means is supplied to the recording means in place of the audio signal, and the rotary head causes the magnetic tape to record the video signal in the same shape as the track shape of the audio mode. When the video mode reproduction is set by the mode switching means, the digital television video signal reproduced by the reproduction means is supplied to the format reverse conversion means and returned to the state before the digital compression conversion, and the digital data is supplied to the liquid crystal display panel to generate an image. And the control means for displaying Magnetic recording and reproducing apparatus characterized by Bei was.