JP2677872B2 - Magnetic recording / reproducing device - Google Patents

Description

The present invention relates to a magnetic recording / reproducing apparatus configured to record / reproduce two types of video signals having different screen aspect ratios.

[Conventional technology]

The EDTV (Extended D), which is being studied for the purpose of improving the image quality and realism of the NTSC system, which is the current TV system
Among efinition TV) broadcasting systems, various wide-screen television systems have been considered in which the aspect ratio (also called the aspect ratio) of the screen is expanded. In this wide screen television system, a certain degree of compatibility is taken into consideration so that the current NTSC system television receiver can receive images that are practically acceptable.

As a conventional example of this wide screen television system, Technical Report of Television Society of Japan Vol. 12, No. 30, PP. 43-48 (Showa
Current NTSC as described on August 25, 63)
For the aspect ratio a ₂ (4: 3 or 4/3) of the screen of the method,
In the wide screen television system, the image information of both left and right ends (also called side panels) is multiplexed and the aspect ratio is increased.
It is conceivable to transmit a ₁ (eg 16: 9 or 16/9) multiplexed video signals. It is also possible to transmit a signal having an aspect ratio a _{1 obtained} by squeezing the upper and lower parts of the screen (multiplexing an auxiliary signal for improving the resolution on the upper and lower blank parts).

Multiplexed video signal obtained by multiplexing the side panel and the auxiliary signal information for configuring these screen aspect ratio a ₁ is because it can receive the current receiver, this signal a conventional magnetic recording and reproducing apparatus (rotary head helical-scan method It is possible to record it on a home video tape recorder, called a VTR).

[Problems to be solved by the invention]

In the conventional VTR, the recording / reproducing of the multiplex video signal is not taken into consideration, and the difference in aspect ratio and the distinction from the current NTSC system video signal have not been considered. Therefore, when multiplex video signals are recorded and played back with a conventional VTR,
Since the recording band is narrow, the resolution is deteriorated, and if the reproduction screen becomes horizontally long or vertically long, various problems occur.

It is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of recording / reproducing two types of video signals having different aspert ratios on the screen with good quality and ease of use.

[Means for solving the problem]

The above-mentioned purpose is a video signal for discriminating whether the input signal to be recorded is a multiplexed video signal with an aspect ratio a ₁ (a signal after passing through a wide decoder described later) in which side panel information is multiplexed or a standard video signal with an aspect ratio a _1. When the discriminating means and the input signal to be recorded are multiple video signals, the time axis is extended.
Recording means for recording in the normal (standard) recording mode of the VTR or recording in the high image quality recording mode having a band that is approximately a ₁ / a ₂ times or more of the standard recording mode without expanding the time axis and magnetic recording during reproduction Provided is a video signal discriminating means for discriminating whether the signal reproduced from the medium (magnetic tape) is a multiplexed video signal or a standard video signal, and a time axis expanding means for expanding the time axis of the reproduced signal by approximately a ₁ / a ₂ times. , When the playback signal is a multiplexed video signal, the signal that is not expanded when displaying on a wide display corresponding to the aspect ratio a ₁ is the output signal, and the signal that is expanded when displaying on a standard display corresponding to the aspect ratio a ₂ is output This is achieved by adopting a signal configuration.

[Action]

The screen information of the multiplexed video signal after passing through the wide decoder is compressed by about a ₁ / a ₂ times compared with the standard video signal, but when using a magnetic tape compatible with high image quality, it is recorded in the high image quality recording mode. Since recording can be performed without deteriorating the resolution and the type of input signal to be recorded is determined, there is no inconvenience such as erroneously recording the multiplexed video signal in the normal recording mode. If the magnetic tape is not compatible with high image quality, the time axis is extended and recording is performed in the normal recording mode.

During playback, when the signal played from the magnetic tape is a multiple video signal, when displaying on a wide display corresponding to the aspect ratio a ₁ , the signal with the time axis not expanded is used as the output signal, so an image with the aspect ratio a ₁ is displayed. When a standard display compatible with an aspect ratio of a ₂ is displayed, the expanded signal is used as the output signal, so the image with an aspect ratio of a ₂ is displayed only in the central part with the side panel cut. There is no inconvenience.

〔Example〕

Embodiments of a magnetic recording / reproducing apparatus according to the present invention will be described below with reference to the drawings.

Before describing the embodiments, first, a wide screen television system will be described.

FIG. 8 is a system configuration diagram showing an example of a wide screen television system, and FIGS. 9 and 10 are signal waveform diagrams of respective parts in FIG.

In FIG. 8, 1 is a wide receiver, 2 is a tuner, 3 is a multiple video signal (or wide) in which side panel information for forming a screen having an aspect ratio a ₁ (16: 9 or 16/9) is multiplexed. Wide decoder for converting (signal) to display a wide screen on a wide display, 4 is an antenna terminal, 5 is an antenna, 6 is a wide output terminal for outputting an output signal a, and 7 is a standard output terminal for outputting an output signal b. , 8 is a wide display with aspect ratio a ₁ (16/9), 9 is the current standard display with aspect ratio a ₂ (4: 3 or 4/3), 10 and 11 are input for each wide display 8 and standard display It is a terminal.

FIG. 9 is a signal waveform diagram when the current standard video signal is received from the antenna 5 of FIG. 8. The output waveform of the tuner 2 is shown in FIG.
Figure 9 as b _S (A), the respectively output waveforms of wide decoder 3 in FIG. 9 (B) as a _S. These waveforms have a horizontal sync signal frequency of f _{H and} a horizontal sync signal period of 1 / f _H
(= 63.56 μs, in case of NTSC system) is shown.

By inputting the waveform of b _S to the input terminal 11 as it is for the standard display 9, a normal screen having an aspect ratio a ₂ (4: 3) as shown in FIG. 9D can be obtained.
Further, for the wide display 8, if it is b _S , it becomes a horizontally long screen (a circular figure becomes an elliptical figure) and the time axis is compressed by the wide decoder 3 (t _{2 in} FIG. 9).
By inputting the waveform of a _S multiplied by / t ₁ ) to the input terminal 10, a screen with a normal shape can be obtained. (In this example, the compression is performed by the wide decoder, but the compression processing is not limited to the wide television system). However, since there is no screen information on both sides (also referred to as side panels) like the shaded area in FIG. 9C, it is replaced with black or gray.

FIG. 10 is a waveform diagram when a multiplex video signal with an aspect ratio a ₁ (16: 9) is received from the antenna 5, and various types of wide-screen television system systems are conceivable. Here, as shown in FIG. Output waveform of the tuner 2 b _W (10th
(Shown in FIG. 6A) (the output waveform of the wide decoder is a _W ).

The portion of the video signal other than the horizontal blanking period including the horizontal synchronizing signal and the color burst signal (τ ₁ + τ ₇ + in FIG. 9)
The τ ₂ part) is the screen information, but the current receiver has about 8% of the overscan part (τ ₁ and τ ₂ part), so in the wide display screen (C), a _W τ ₆ period. By compressing the central portion of b _W into τ ₁ and τ ₂ (corresponding to encoding), a multiple video signal b _W can be created. In this embodiment described later, a case where the above b _W is transmitted will be described. Further, the difference between the standard video signal and the multiplexed video signal will be described in the case where the pulse width of the horizontal synchronizing signal is differentiated by setting τ _HW shorter than the standard τ _HS .

The output signal b _W of the tuner 2 in FIG.
As a result, the central part is compressed from τ ₇ to τ ₆ (approximately a ₁ / a ₂ times), and the side panel parts are expanded and restored from τ ₁ to τ ₄ and τ ₂ to τ ₅ , respectively, resulting in a _{W and} wide display 8
And a wide screen is displayed as shown in FIG. 10 (C). In this example, τ ₁ = τ ₂ and τ ₄ = τ ₅ . b _W
When the standard display 9 is used to display the signal No. ₇ , the τ ₇ portion, that is, the central portion is normally displayed as shown in (D) (the τ ₁ and τ ₂ portions are not displayed on the screen because of overscan).

Next, a first embodiment of the present invention will be described with reference to FIGS. 1 and 10.

FIG. 1 is a block diagram showing a first embodiment of a magnetic recording / reproducing apparatus according to the present invention. 10 is a magnetic recording / reproducing apparatus for recording / reproducing two kinds of video signals having different aspect ratios according to the present invention, 11 is a wide input terminal, 12 is a standard input terminal, 13,17,18,26,30 are switches SW ₁ , SW ₂ , SW ₃ , SW ₄ , SW ₅ , SW ₅ and 14 that can be switched by control signals Discrimination circuit for discriminating whether the signal is a wide signal or a standard signal, 15
Is a recording circuit for recording in the high-quality mode, 16 is a recording circuit for recording in the standard mode, 19 is a recording head, 20 is a magnetic tape as a recording medium, and 21 is a reproducing head (may be combined with the recording head) , 22 is a preamplifier, 23 is a high-quality playback circuit that performs playback processing such as demodulation of the FM-modulated preamplifier output signal, 24 is a standard mode playback circuit, and 25 is whether the playback signal is recorded in high-quality mode. , 27 is a video signal discrimination circuit for discriminating whether or not the reproduced signal is a wide signal, and 28 is a τ of the reproduced wide signal (the waveform is shown in a _W of FIG. 10B). It is a time axis expansion circuit that expands the portion of ₆ to τ ₇ .

Next, the operation of FIG. 1 will be described for each type of input signal to be recorded.

(1) When the input signal is a multiplexed video signal (wide signal), a _W and b _W in FIG. 10 are applied to the wide input terminal 11 and the standard input terminal 12, respectively. On the other hand, a _W and b _W are also input to the wide discriminating circuit 14, and this output is “H” (when at least one of the signals at the input terminals 11 and 12 is wide, it is set to “H”). ₁ is the wide side (upper side in FIG. 1).
When the recording mode command m becomes "H" (the high quality recording mode is "H" and the standard recording mode is "L") from the system control unit (not shown) or the like, SW ₂ of 17 is set to the upper side, 18 S
Since W _{3 is} also on the upper side, the wide signal a _W is eventually applied to the recording head 19 through the high quality recording circuit.

FIG. 2 is a spectrum diagram of a video signal recorded by the recording circuit.

In the figure, wide signal in FIG. 10 is compressed to approximately a ₂ / a ₁ × (3/4) tau ₇ parts of b _W until the portion of tau ₆ of a _W, of a _W The signal band of τ ₆ part is about a ₁ / a ₂ times (4/3 times)
It has a high bandwidth. Therefore, when recording a wide signal of a _W , the original resolution cannot be maintained unless it is set to approximately a ₁ / a ₂ times or more the band of the conventional VTR. Therefore, the band of the high image quality recording circuit 15 may be set to approximately a ₁ / a ₂ times or more, but in the current VTR, for example, the high image quality mode S for the VHS system is used.
-Because there are ED-β method etc. for VHS method and β method,
These modes should be used when using high quality tape.

In Fig. 2, (A) shows the characteristics of the VHS standard mode, F
The sync chip frequency during M modulation is f _LS (3.4 MHz) and the white peak frequency f _LW (4.4 MHz) has a resolution of about 250 lines. On the other hand, in the S-VHS mode, as shown in FIG. 2B, sync tip frequency f _HS (5.4 MHz), white peak frequency f _HW (7.0 MHz) and deviation 1.6
It has double the resolution and 400 lines. Therefore, it becomes almost a ₁ / a ₂ times, and a wide signal can be recorded sufficiently.

At the time of reproduction, the discriminating circuit 25 discriminates from the FM modulation signal output from the preamplifier whether the recording signal is in the high image quality mode (it becomes "H" in the high image quality mode), and the SW ₄ of 26 is switched to the upper side. The high image quality discrimination circuit 25 can easily discriminate between high and low frequencies of the FM signal as used in the discrimination of the S-VHS mode. With the wide signal passing through the upper 26 of SW ₄ is outputted from the output terminal 31 to the wide Deisupurei, through expansion circuit 28, a portion of tau ₆ of a _W in FIG. 10 as b _W of tau ₇ It is expanded to approximately a ₁ / a ₂ times (there is no need to do anything in the τ ₁ and τ ₂ portions and the horizontal blanking period), and is output from the output terminal 32 to the standard display through the upper side of SW ₅ of 30. The structure of the decompression circuit is FIFO (First in Firs) after A / D conversion.
The normal configuration for D / A conversion through a line memory of type (t out) type is sufficient, and the ratio of the write clock and the read clock given to the memory may be increased by a ₂ / a ₁ .

Further, as in the case of recording, the wide discriminating circuit 27 discriminates whether or not the reproduced signal is a wide signal, and if it is a wide signal, the output of the wide discriminating circuit 27 is set to "H" and the SW ₅ of 30 is switched to the upper side. In this example, the determination of the wide signal is made based on the size of the pulse width of the horizontal synchronizing signal, but as a method of this determination, for example, the pulse width is counted by a high-speed clock, the pulse width is measured, and the determination is made by a comparator. It is possible in the usual way.

(2) When the input signal is a standard video signal, a _S and b _S shown in FIG. 9 are applied to the wide input terminal 11 and the standard input terminal 12, respectively. The wide discriminating circuit outputs "L" from the pulse width of the horizontal synchronizing signal, and the signal b _S is selected through the lower side of SW ₁ of 13. When the recording mode command m using the high quality tape is "H", it is recorded on the magnetic tape in the high quality recording mode (for example, in consideration of the compatibility with the old VTR which does not have the S-VHS mode, the standard video signal Sometimes the standard recording mode may be selected).

At the time of reproduction, similarly to the above, after determining whether it is the high image quality mode, the wide determining circuit 27 determines whether it is a wide signal. Since it is a standard signal, the output of the wide discriminating circuit 27 is "L", the SW ₅ of 30 is on the lower side, and the signal is directly output from the output terminal 32 without passing through the expansion circuit 38.

FIG. 3 is a block diagram on the recording side showing a second embodiment of the magnetic recording / reproducing apparatus according to the present invention, in which a multiple video signal (wide signal) is substantially a ₁ / a even when a high quality tape is not used.
_This is an example in which the time axis is doubled for recording.

In the figure, 101, 102 and 103 are switching switches SW ₁₁ and SW.
₁₂ , SW ₁₃ , 104, and 105 are time axis expansion circuits for multiplying the time axis by approximately a ₁ / a ₂ times, and the same reference numerals and signal names as those in FIG. 1 will be used for explanation.

When the input signal to be recorded is a multiplex video signal, the SW ₁₁ of 101 is set to the upper side by the wide discriminating circuit 14 and the wide signal after decoding is input from the input terminal. Recording mode command n If it is not a high quality tape, it becomes "L" and SW ₁₃ becomes lower and the output of the gate 104 becomes "H" and SW _{12 of} 102
Is the upper side, and the wide signal (10th
The shape of b _{W in} the figure) is recorded on the magnetic tape 20 via the standard recording circuit 16. Although the time axis expansion circuit 105 is used here, it goes without saying that an encoder for converting a _W into b _W in FIG. 10 (not necessarily an expansion process) may be used. When a wide signal is recorded with a high quality tape or a standard video signal is recorded, the output of the gate 104 becomes "L" and the expansion operation is not performed. The expansion circuit on the recording side can be shared with that on the reproduction side. As described above, if the time-axis expansion is performed for recording, an image can be reproduced with a normal aspect ratio even when the tape is not a high-quality tape, and the resolution is not deteriorated.

Next, as a third embodiment of the present invention, an example will be described in which the signal before passing through the wide decoder is recorded instead of using the time axis expansion circuit 105 in FIG.

FIG. 4 is a block diagram showing a third embodiment of the magnetic recording / reproducing apparatus according to the present invention, in which 201, 202 and 203 are switching switches SW ₂₁ , SW ₂₂ , SW ₂₃ and 204 are gates. This embodiment is suitable when the wide receiver shown in FIG. 8 is connected.

When the multiplex input signal is recorded without using the high quality tape as in the case of FIG. 3, the SW ₂₁ of 201 becomes the upper side because the wide discriminating circuit 14 becomes “H”. Since the recording mode command P is “L”, the output of the gate 204 is “H”, the SW ₂₂ of 202 is the upper side, and the signal of the terminal 11 is selected by the SW _{21 of} 201, but the signal to be actually recorded is the first. A signal of the shape b _{W in} FIG. 10 (before passing through the wide decoder 3 in FIG. 8) is input from the terminal 12 and recorded through the standard recording circuit 16.

It should be noted that the merits when using the time axis expansion circuit as shown in FIG.
This is effective when there is only a decoded signal like a _W in FIG. 10 (in this case, it is input only to the input terminal 11). If either the multiplex video signal is input to the terminal 11 or the standard video signal is input to the terminal 12, the input signal of the one connected using the means for determining the presence of the input signal May be selected. Next, as a fourth embodiment of the present invention, an example will be described in which optimum recording can be performed even when signals before and after passing through the wide decoder are input to one input terminal.

FIG. 5 is a block diagram showing a fourth embodiment of the magnetic recording / reproducing apparatus according to the present invention, in which 301 is a decoding discriminating circuit for discriminating before or after decoding, for example, τ ₁ at b _W in FIG. Difference between the frequency components of the signal at the boundary between τ and τ ₇ (the τ ₁ part is compressed) or discontinuity at the boundary (a _W
Then, there is no discontinuity). Also,
302 is a time axis expansion circuit, 303 and 304 are switching switches SW ₃₁ and S
W ₃₂ .

When the input signal to be recorded is a multiplexed video signal, first, when the signal a _W1 after passing through the decoder or the signal a _W2 from the wide video camera is input, the decode determination circuit 301 determines that the signal has been decoded. Output "H" and switch SW ₃₁ 303
Becomes the upper side, and the expansion circuit 302 is enabled. In this state, when the recording mode command q is "H", recording is performed through the high image quality recording circuit without expansion, and when it is "L" (when no high image quality tape is used), the wide signal (first The shape of b _W in Fig. 4) is recorded automatically. Also, the signal b before the decoder
_{When W1} is input, it is recorded without being expanded. The above is for the recording side, but the same applies to the case where the decoding discrimination means is used on the reproducing side.

In the above description, when a signal is input from a tuner, a wide video camera, etc., a single connecting line has been described (for example, a format like a composite signal), but this is for separating the video signal Y and the chromaticity signal C. State (other than R, G, B, Sync
(Synchronous signal) format and Y, RY, BY color signal format, etc.) can be connected, and in this case, especially in the case of composite format, side panel Since the same color sub-carrier frequency (about 3.58MHz in NTSC) as that in the center is used, the dot interference due to the color sub-carrier does not become coarse and difficult to see, especially for composite signals. This is a desirable connection form, such as when connecting to a wide video camera that does not need to be set.

Further, in the above description, the case where the side panel information is compressed in the overscan portion as the wide screen television system has been described, but other methods, for example, the method of utilizing the horizontal blanking portion or the vertical overscan portion. The present invention can be similarly applied to the above by corresponding the discriminating means and the like.
Also, when transmitting a wide aspect ratio signal with aspect ratio a ₁ that squeezes the upper and lower parts of the screen (multiplexing the resolution improvement signal in the upper and lower blanks), the high quality mode is used for the signal after the wide decoder. The concept of the present invention such as recording in the same manner can be similarly applied.

Next, as a fifth embodiment of the present invention, an example in which discrimination information (ID information) indicating that the input signal to be recorded is a multiplex video signal will be described on a magnetic tape.

FIG. 6 is a block diagram showing a fifth embodiment of the magnetic recording / reproducing apparatus according to the present invention, and FIG. 7 is a signal waveform diagram for explaining the operation of FIG.

In FIG. 6, 401, 404, 405, and 406 are switching switches, 402 is a sync separation circuit, 403 is a pulse generation circuit, and 407 is an inverter.
This is the same as in the case of FIG. In this embodiment, a case will be described in which the standard video signal and the multiplexed video signal are transmitted with the width of the horizontal synchronizing signal being constant (τ _HS ).

In this case, since it is not possible to discriminate at the time of reproduction if the recording is performed as it is, the width is converted to be narrow and the wide signal is recorded on the magnetic tape as shown in FIGS. That is, when a command S for recording a wide signal is received from the system control or the like (S is "H"), the SW ₄₁ of 401 becomes "H" and the wide signal a _W 'is selected. a _W ′ is the signal after decoding whose horizontal sync signal width is τ _HS . The horizontal sync signal f _H is separated from a _W by using the sync separation circuit 402, and τ _HW having a width narrower than τ _HS is generated by the pulse generation circuit 403, and the horizontal sync signal of the period a _W ′ of τ _HS is f _HW. Is recorded on the magnetic tape as a _W ″ replaced with the above. The above is an example in which the ID information is recorded by changing the width of the horizontal synchronizing signal, but it is also used in 8 mm video. A low frequency pilot signal which does not cause interference may be recorded when a wide signal is used, or various other methods such as recording an ID signal during a vertical blanking period are possible.

Since there are various cases when recording two types of signals as described above, the recording mode is high image quality (high bandwidth).
The usability is improved by providing a display for indicating whether the mode is a mode, the recording signal is a wide signal, the reproduction mode is a high image quality mode, and the reproduction signal is a wide signal. These indicators need not necessarily be provided independently, but may be shared for recording and reproduction.

〔The invention's effect〕

As described above, according to the present invention, whichever of the two types of video signals having different aspect ratios is input as the input signal to be recorded, it is recorded on the tape in the optimum state,
It can be played back, the resolution is not deteriorated, and even if the type of display is different, it does not cause any inconvenience when it becomes a landscape or portrait screen, and it improves the usability of the user. A playback device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a magnetic recording / reproducing apparatus according to the present invention, FIG. 2 is a spectrum diagram of recording signals in a standard recording mode and a high quality recording mode, and FIG. 3 is a magnetic recording according to the present invention. A block diagram showing a second embodiment of the reproducing apparatus, FIG. 4 is a block diagram showing a third embodiment of the magnetic recording / reproducing apparatus according to the present invention, and FIG. 5 is a fourth drawing of the magnetic recording / reproducing apparatus according to the present invention. FIG. 6 is a block diagram showing an embodiment, FIG. 6 is a block diagram showing a fifth embodiment of the magnetic recording / reproducing apparatus according to the present invention, FIG. 7 is a waveform chart of each part for explaining the operation of FIG. 6, and FIG. A system diagram showing an example of a wide screen television system, FIGS. 9 and 10 are waveform diagrams of respective parts for explaining the operation of FIGS. 8 and 1. 14 …… Wide discriminating circuit, 15 …… High quality recording circuit, 16 ……
Standard recording circuit, 23 …… High quality reproduction circuit, 24 …… Standard reproduction circuit, 25 …… High quality discrimination circuit, 27 …… Wide discrimination circuit,
28 …… Time axis expansion circuit.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Atsushi Yoshioka 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (72) Hideichi Matsuo 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Video Engineering Co., Ltd. (72) Inventor Tadashi Otsubo 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Home Appliances Research Laboratory, Hitachi, Ltd. (56) Reference JP 63-98870 (JP, A) JP 2-170789 (JP, A)

Claims (4)

(57) [Claims] 1. A magnetic recording / reproducing apparatus capable of selectively recording a multiplexed video signal in which information for forming a screen with an aspect ratio a ₁ and a standard video signal for forming a screen with an aspect ratio a ₂ are selectively recorded. A video signal discriminating means for discriminating whether the signal reproduced from the recording medium is a multiplexed video signal or a standard video signal; and a time axis expanding means for expanding the time axis of the reproduced signal by approximately a ₁ / a ₂ times. Then, when the video signal discrimination means detects a multiple video signal,
A magnetic recording / reproducing apparatus characterized in that both a reproduction signal which is not expanded and a signal which is obtained by expanding the reproduction signal by the time axis expansion means are selectable as output signals. 2. The magnetic recording / reproducing apparatus according to claim 1, further comprising a video signal discriminating means for discriminating whether the input signal to be recorded is a multiplexed video signal or a standard video signal. 3. The magnetic recording according to claim 1, further comprising display means for displaying whether or not the input signal to be recorded is a multiplexed video signal and whether or not the reproduced signal is a multiplexed video signal. Playback device. 4. A magnetic recording / reproducing apparatus according to claim 1, further comprising a discriminating means for discriminating whether or not an input signal to be recorded is a signal after passing through a wide decoder.