JP2509501B2 - Video signal magnetic recording / reproducing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal magnetic recording / reproducing apparatus, and more particularly, to automatically switch and record two kinds of modes having different carrier frequencies, and to automatically switch and reproduce them. The present invention relates to a video signal magnetic recording / reproducing device.

[0002]

2. Description of the Related Art In recent years, the performance of magnetic tapes and the performance of magnetic heads have improved, and there has been a demand for VTRs with higher resolution and higher image quality. For this reason, for example, a high-performance magnetic tape using metal, vapor deposition, barium ferrite or the like is used in place of the standard magnetic tape using the iron oxide magnetic material used in the current home VTR, and this magnetic tape is currently used. Various high image quality modes have been considered in which recording is performed at a carrier frequency sufficiently higher than the carrier frequency of the standard mode used in the domestic VTR.

[0003]

Therefore, in order to use the standard mode and the high image quality mode in one VTR, for example, a switch for switching between the both modes is provided, and the user can arbitrarily select the mode. Switching operation is conceivable. However, in this case, since the cassette cases have almost the same shape, the mode switching operation is performed by discriminating the standard cassette containing the standard magnetic tape and the high performance cassette containing the high performance magnetic tape one by one. However, there is a problem in that, for example, even if the standard cassette is used, an erroneous operation such as setting and recording in the high image quality mode is performed, and there is a possibility that it may be mistaken for a failure when reproducing this. .

Further, when recording, even a high-performance cassette may be recorded in the standard mode. Therefore, at the time of reproduction, the high-performance cassette may be recorded in the high-quality mode or the standard mode simply by looking at it. However, there is a problem such as confusion in the mode switching operation. Furthermore, there is a possibility that a high-performance cassette recorded in the high image quality mode may be reproduced in the standard mode, or a standard cassette recorded in the standard mode may be reproduced in the high image quality mode. There is a problem that it cannot be reproduced.
The present invention automatically distinguishes between a standard cassette and a high-performance cassette at the time of recording, and at the time of reproduction, automatically distinguishes in which mode the signal was recorded, so that each can be reproduced in an appropriate mode. An object is to provide a recording / reproducing device.

[0005]

In a video signal magnetic recording / reproducing apparatus for recording / reproducing an input video signal on a magnetic tape provided on a cassette, the recording system detects the identification section provided on the cassette. Equipped with a cassette discriminating means for discriminating whether any one of a standard cassette accommodating a standard magnetic tape and a high performance cassette accommodating a high performance magnetic tape is mounted in the apparatus, and when discriminating the standard cassette, A standard recording mode in which a luminance signal separated from the input video signal is FM-modulated at a first carrier frequency and recorded, and when the high-performance cassette is discriminated, the luminance signal is higher than the first carrier frequency. F at a carrier frequency of 2
A high performance recording mode in which M modulation is performed for recording, and the reproduction system is a luminance reproduction signal related to the luminance signal for supplying the reproduction signal reproduced from the magnetic tape to the luminance signal reproduction system. And a separation means for performing frequency separation into a color reproduction signal related to the color signal for supplying to a color signal reproduction system, and the magnetic tape in the standard recording mode or the high performance based on the frequency component of the luminance reproduction signal. A reproduction discriminating means for discriminating whether or not the recording was carried out in the recording mode, and the luminance signal reproducing system, when it is discriminated that the magnetic tape is recorded in the standard recording mode, the first carrier frequency When the magnetic tape is determined to be recorded in the high performance recording mode, the high performance reproduction mode for performing FM demodulation corresponding to the second carrier frequency is set. Video signal magnetic recording and reproducing apparatus, characterized in that the configuration and formed by reproducing system to.

In a video signal magnetic recording / reproducing apparatus for recording / reproducing an input video signal on / from a magnetic tape provided on a cassette, the recording system stores a standard magnetic tape by detecting an identification section provided on the cassette. Equipped with cassette discriminating means for discriminating whether each of the standard cassette and the high-performance cassette containing the high-performance magnetic tape is mounted in the apparatus, and when discriminating the standard cassette, it is separated from the input video signal. The standard recording mode in which the luminance signal is FM-modulated at the first carrier frequency and recorded, and when the high performance cassette is discriminated, the luminance signal is FM-modulated at the second carrier frequency higher than the first carrier frequency. A reproducing system for performing a high-performance recording mode of modulating and recording, and the reproducing system supplies a reproduced signal reproduced from the magnetic tape to a luminance signal reproducing system. Of a luminance reproduction signal relating to the luminance signal and a color reproduction signal relating to the color signal to be supplied to the color signal reproducing system. After passing through the amplitude control means for controlling the amplitude of the input signal to a predetermined value and outputting it, it is determined based on the frequency component whether the magnetic tape was recorded in the standard recording mode or the high performance recording mode. When it is determined that the magnetic tape is recorded in the standard recording mode, the FM demodulation corresponding to the first carrier frequency is performed, and the magnetic tape is recorded in the high performance recording mode. The video signal magnetic recording and reproducing apparatus is a reproducing system configured to perform FM demodulation corresponding to the second carrier frequency when it is determined that

[0007]

[Example] FIG. 3 shows a standard cassette 1 for a home VTR.
Contains the iron oxide magnetic tape used in.
In the figure, 2a and 2b are shaft holes, 3 is a capstan fitting recess, 4a and 4b are tape pulling member fitting recesses, 5 is a lid,
6 is a recess for preventing erroneous insertion.

FIG. 4 shows a high performance cassette 7, which has substantially the same shape as the standard cassette 1 and stores a high performance magnetic tape such as a metal tape. In the figure, 6a is a cassette discriminating hole, which is provided in a part of the erroneous insertion preventing concave portion 6.

FIG. 1 is a block system diagram of an embodiment of the device of the present invention, and FIG. 2 is a schematic plan view thereof. In FIG. 2, reference numeral 8 denotes a cassette discriminating pin, which is configured to move up and down by a spring action, for example, and is provided at a position facing the cassette discriminating hole 6a when the high performance cassette 7 is mounted. .

When the standard cassette 1 is mounted on the apparatus shown in FIG. 2, the cassette discriminating pin 8 is displaced downward, whereby the cassette discriminating circuit 1 shown in FIG.
The standard cassette switching signal is extracted from the
Is connected to terminal A to enter the standard mode. On the other hand, when the high performance cassette 7 is attached to the device shown in FIG. 2, the cassette discriminating pin 8 is returned to the original position, and as a result, the device shown in FIG.
A high performance cassette switching signal is taken out from the cassette discriminating circuit 13 shown in (1), the switch 14 is connected to the terminal B, and the high image quality mode is set.

As described above, the modes can be automatically switched to each other simply by mounting different types of cassettes on the apparatus. In this case, since the cassette discriminating hole 6a is protected by the stepped portion of the erroneous insertion preventing concave portion 6, it is possible to prevent dust and the like from entering as much as possible. Further, when the cassette is inserted into the mounted holder, the holder descends and at the same time, the cassette discrimination pin 8 and the cassette discrimination hole 6a engage with each other. Both serve as guides, and the two are reliably engaged.

Next, a method of recording by using different carrier frequencies according to each mode will be described. In FIG. 1, the video signal input to the terminal 9 is supplied to a low-pass filter and a comb filter 10a having a cutoff frequency of, for example, about 3 MHz and a low-pass filter and a comb filter 10b having a cutoff frequency of, for example, about 5 MHz. Here, the luminance signal components are used, and the pre-emphasis circuit 1 respectively
FM modulators 12a, 1 are enhanced by the high frequencies 1a, 11b.
2b is supplied. The FM modulator 12a performs FM modulation using a carrier frequency of 3.4 MHz to 4.4 MHz as described later to form an FM luminance signal in a standard mode.
The FM modulator 12b has a carrier frequency of 5.0 MHz to 6.7 M
FM in high quality mode with FM modulation using Hz
The luminance signal is supplied to the adder 15 via the switch 14 switched according to each mode.

In the standard mode, the frequency spectrum of the FM luminance signal is as shown by XX in FIG. 5, and in the high image quality mode, the carrier frequency is set higher than that in the standard mode as shown by YY in the figure.

In the frequency spectrum XX of the FM luminance signal shown in FIG. 5, fas, fap and faw represent carrier frequencies at the sync tip level S, pedestal level P and white peak level W of the luminance signal shown in FIG. Similarly, in the frequency spectrum YY, fbs, fbp and fbw represent carrier frequencies at the sync tip level S, pedestal level P and white peak level W of the luminance signal. For example, the carrier frequency fas in the standard mode is 3.4 MHz.
z and fap are 3.8 MHz, faw is 4.4 MHz, and the carrier frequency fbs in the high image quality mode is 5.0 MHz and fbp.
Is 5.6 MHz and fbw is 6.7 MHz.

As can be seen from FIG. 5, at the carrier frequencies fap and fbp corresponding to the pedestal level, there are frequency components of the sidebands of the FM luminance signal of the other mode, but the energy of the carrier frequencies fap and fbp is different. Is much larger than the energy of the sideband component of the same frequency in the other mode. At the time of reproduction in the present invention, attention is paid to this point to determine the mode.

On the other hand, the video signal input to the terminal 9 is converted into a chroma signal by the band-pass filter 16, processed by the recording chroma processing circuit 17 and then added by the adder 15 with the FM luminance signal. The output of the adder 15 is amplified by the recording amplifier 18, supplied to the magnetic heads 191 and 192, and recorded on the magnetic tape 20.

In the above embodiment, the cassette discriminating hole is provided in the cassette to discriminate the type of the cassette.
In the next embodiment, the type of cassette is identified by a bar code.

FIG. 7 shows a standard cassette 21, which contains an iron oxide magnetic tape. For example, a recess 22 is formed on the upper surface thereof.
Is provided, but a bar code described later is not provided here.

FIG. 8 shows a high performance cassette 23 in which a high performance magnetic tape such as a metal tape is stored, and a bar code 24 is provided in a recess 22 on the upper surface thereof.
Further, FIG. 9 shows a small high-performance cassette 25, and a bar code 26 is provided on the upper surface thereof as in the case of FIG.
Bar code 24,2 of these high performance cassettes 23,25
6 is when the cassette is mounted in the magnetic recording and reproducing device,
It is provided at a position facing the barcode detection unit (optical sensor) 27 shown in FIGS. 10 and 11 provided here.

Here, when the standard cassette 21 is mounted, the optical sensor 27 does not operate because there is no bar code here, so that the standard cassette switching signal is taken out from the cassette discriminating circuit 13 shown in FIG. Switch 14 is connected to terminal A to enter standard mode. On the other hand, when the high performance cassette 23 or 25 is mounted, the optical sensor 27 reads the bar code 24 or 26, whereby the high performance cassette switching signal is taken out from the cassette discriminating circuit 13 shown in FIG. It is connected to B and the high-quality mode is set.

Also in this case, similarly to the above-described embodiment, the modes can be automatically switched by simply mounting the different types of cassettes in the apparatus.

As described above, in the apparatus of the present invention, the mode switching is automatically performed only by mounting the cassette, so that it is not necessary to discriminate and judge the cassettes one by one and perform the mode switching. Despite this, there is no erroneous operation such as recording in the high image quality mode.

Next, the operation during reproduction will be described.

In the figure, the frequency division multiplexed signal of the FM luminance signal and the low-frequency conversion carrier color signal recorded on the magnetic tape 20 is alternately reproduced by the magnetic heads 191 and 192, and the terminals are passed through the preamplifiers 281 and 282. The signal which is supplied to the switch 29 which is switched by the head switching pulse of 2 feel cycle from 30 and is made into a continuous signal here is separated by the high-pass filter 31 and the low-pass filter 32, and the luminance signal reproducing system AA is obtained. It is supplied to the color signal reproducing system BB. The reproduced FM luminance signal separated and filtered by the high-pass filter 31 is equalized by the equalizer circuit 33a in the high image quality mode and the equalized circuit 3 in the standard mode.
AG which is supplied to the switch 34 through 3b separately and further controls and outputs the amplitude of the input signal to a predetermined value.
A limiter 36 and a mode discriminating circuit 37 via the C circuit 35.
Respectively.

The reproduced FM luminance signal from which the amplitude fluctuation component has been removed by the limiter 36 is supplied to the switch 41 via the FM demodulator 38a of the standard mode reproduction system, the low-pass filter 39a and the de-emphasis circuit 40a, while the image quality is high. FM demodulator 38b and low-pass filter 39b of mode reproduction system
And the switch 41 via the de-emphasis circuit 40b.

On the other hand, as will be described later, the mode discriminating circuit 37 automatically discriminates whether the reproduced FM luminance signal is recorded in the standard mode or the high image quality mode. It is then supplied to the switches 34 and 41 as switching pulses. As a result, the switches 34 and 41 are connected to the terminal A side when the standard mode is determined, and are switched and connected to the terminal B when the high image quality mode is selected.

The reproduction signal extracted from the switch 29 is subjected to the low-pass filter 32 to separate and filter the low-pass conversion carrier color signal, and the reproduction chroma processing circuit 43 removes the jitter by a known means. At the same time, the reproduced carrier color signal in the original band is returned. The adder circuit 44 adds and combines the reproduced carrier color signal and the reproduced luminance signal reproduced and demodulated by the reproducing system in the same mode as that at the time of recording, which is output from the switch 41 to the output terminal 45 as a reproduced color video signal. To do.

Next, the operation of the mode discriminating circuit 37 will be described.

FIG. 12A shows a concrete block system diagram of an embodiment of the mode discriminating circuit 37, and FIG. 13 shows a detailed circuit diagram thereof. The reproduced FM luminance signal input to the terminal 46 is converted into a narrow band signal by the band filter 47a whose pass band is set near the standard mode frequency fap (FIG. 5), while the pass band is set to the high image quality mode frequency fbp. (FIG. 5) A narrow band signal is generated by the band filter 47b set in the vicinity. These narrow band signals are detected and detected by the peak hold circuit 48a,
The peak is held at 48b, and the low-pass filter 4
The unnecessary frequency components are removed at 9a and 49b to obtain a DC signal. By passing these low-pass filters 49a and 49b, FM caused by noise bars at the time of searching and stealing
Malfunctions at the signal missing part are prevented.

The output DC signals of the low-pass filters 49a and 49b are supplied to the comparator 50 where they are compared in level, and the above-mentioned mode discriminating signal corresponding to each mode is taken out from the output terminal 51 and shown in FIG. It is supplied to the system controller 42.

FIG. 12B shows a concrete block diagram of another embodiment of the mode discriminating circuit 37. In this device, the output level of the low-pass filter 49 is compared with the reference voltage Vref by the comparator 52, and the mode discriminating signal corresponding to each mode is thereby output.

When the output DC signal levels of the low-pass filters 49a and 49b are substantially the same and the levels are not stable due to noise or the like, the output signal of the comparator 50 causes so-called chattering, so that the comparator 50 has hysteresis. The chattering may be prevented by providing characteristics.

Further, the peak hold circuits 48a, 48b,
The peak hold at 48 is less affected by the video section as the time constant is longer, but on the other hand, the amplitude of the FM signal extracted by noise or the like changes greatly and the comparator 5
If the output of 0, 52 is inverted, it takes a long time to recover. Therefore, the time constant is selected to be an optimum value that is not affected by the video section and that the recovery time is short. As described above, the device of the present invention automatically determines in which mode the signal is recorded and switches to an appropriate mode only by reproducing the cassette. here,
When reproducing the data recorded in the standard mode on the high performance cassette 7 (FIG. 4) or 23 (FIG. 8), 25 (FIG. 9) by using the conventional magnetic recording / reproducing device, simply, Even if the cassettes 7, 23, 25 are mounted and the cassette discrimination holes 6a or the barcodes 24, 26 are detected to discriminate the high performance cassettes 7, 23, 25 and the high image quality mode is set, the standard mode is set. It doesn't mean that the reproduction of is dealt with. However, in the device of the present invention, since the cassette is reproduced and switched to that mode, when a high-performance cassette recorded in the standard mode is mounted using the conventional device, without switching to the high image quality mode, Properly switch to standard mode.

In the apparatus of the present invention, the output of the cassette discriminating circuit 13 is supplied to the system controller 42 at the time of reproduction to switch the switches 34 and 41 to the respective modes. As a result, the high performance cassette 7,23,2
When the data recorded in the high-quality mode 5 is reproduced, or when the data recorded in the standard cassettes 1 and 21 in the standard mode is reproduced, the mode can be switched more surely. In this case, for example, when reproducing what was recorded in a standard mode on a high-performance cassette with a conventional device with the device of the present invention,
The device is once set to the high image quality mode, but since it immediately switches to the standard mode by the reproduction signal, there is no problem.

Further, during reproduction, the output of the cassette discriminating circuit 13 may not be supplied to the system controller 42, and the mode may be switched only by the reproduction signal.

Further, as described above, when it is desired to record the high performance cassette in the standard mode for use in the conventional apparatus, as shown in FIG.
Alternatively, a standard mode priority switch may be provided separately from the middle switch 14, and this may be operated during recording for recording.

[0037]

As described above, according to the configuration of the present invention,
Since the type of the cassette can be discriminated by detecting the identification section provided on the cassette, the optimum recording mode can be selected according to the characteristics of the magnetic tape. Without detecting the identification part
Since the recording mode at the time of recording is determined based on the frequency component of the luminance reproduction signal reproduced from the magnetic tape, the standard reproduction is performed even when the high performance magnetic tape provided in the high performance cassette recorded in the standard recording mode is reproduced. There is an effect that it is possible to provide a magnetic recording / reproducing apparatus capable of reproducing in a mode.

Further, as described above, according to the configuration of the present invention, the brightness signal reproduction system is particularly advantageous in that the brightness reproduction signal is controlled by the amplitude control means for controlling the amplitude of at least the input signal to a predetermined value and outputting it. After that, since the recording mode at the time of recording is determined based on the frequency component, the recording can be reliably performed without malfunction even when the running state of the magnetic tape fluctuates and the amplitude of the luminance reproduction signal becomes a small level. There is an effect that the mode can be discriminated.

[Brief description of drawings]

FIG. 1 is a block system diagram of an embodiment of a device of the present invention.

FIG. 2 is a schematic plan view of an embodiment of the device of the present invention.

FIG. 3 is a perspective view of a standard cassette.

FIG. 4 is a perspective view of a high performance cassette.

FIG. 5 is a diagram for explaining a frequency spectrum of an FM luminance signal.

FIG. 6 is a luminance signal waveform diagram.

FIG. 7 is a plan view of a standard cassette.

FIG. 8 is a plan view of a high performance cassette.

FIG. 9 is a plan view of a high performance cassette.

FIG. 10 is a diagram when the cassette is inserted into the device.

FIG. 11 is a diagram showing the positions of the optical sensor and the barcode of the cassette.

FIG. 12 is a specific block diagram of a mode determination circuit in FIG.

13 is a specific circuit diagram of a mode determination circuit in FIG.

[Explanation of symbols]

 1, 21 Standard cassette 6a Cassette discrimination hole (discrimination part) 7, 23, 25 High performance cassette 13 Cassette discrimination circuit (cassette discrimination means) 20 Magnetic tape 35 AGC circuit (amplitude control means) 37 Mode discrimination circuit (reproduction discrimination means) ) AA Luminance signal reproduction system BB Color signal reproduction system

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H04N 9/80 H04N 9/80 A (72) Inventor Hiroshi Yamada 3 Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa 12-chome, Yoichi Yamada, Examiner, Victor Company of Japan, Ltd.

Claims (2)

(57) [Claims] 1. A video signal magnetic recording / reproducing apparatus for recording / reproducing an input video signal on a magnetic tape provided on a cassette, wherein the recording system detects a standard magnetic tape by detecting an identification section provided on the cassette. Equipped with a cassette discriminating means for discriminating whether any one of the standard cassette accommodated and the high performance cassette containing the high performance magnetic tape is mounted in the apparatus, and when the standard cassette is discriminated, the input video signal is inputted. The standard recording mode in which the luminance signal separated from the FM carrier is FM-modulated at the first carrier frequency and recorded, and when the high-performance cassette is discriminated, the luminance signal is set to the second carrier frequency higher than the first carrier frequency. Is a recording system in a high-performance recording mode in which FM modulation is performed for recording, and the reproducing system supplies a reproduced signal reproduced from the magnetic tape to a luminance signal reproducing system. For separating the luminance reproduction signal relating to the luminance signal and the color reproduction signal relating to the color signal to be supplied to the color signal reproducing system, and the magnetic tape based on the frequency component of the luminance reproduction signal. Reproduction discriminating means for discriminating whether the recording was carried out in the standard recording mode or the high performance recording mode, respectively, and the luminance signal reproducing system discriminates that the magnetic tape is recorded in the standard recording mode. When it is determined that the magnetic tape is recorded in the high performance recording mode, the standard reproduction mode for performing FM demodulation corresponding to the first carrier frequency is set, and when it is determined that the magnetic tape is recorded in the high performance recording mode, the second carrier frequency is set. A video signal magnetic recording / reproducing apparatus characterized by being a reproducing system configured to be in a high-performance reproducing mode for performing corresponding FM demodulation. 2. A video signal magnetic recording / reproducing apparatus for recording / reproducing an input video signal on a magnetic tape provided on a cassette, wherein a recording system detects a standard magnetic tape by detecting an identification section provided on the cassette. Equipped with a cassette discriminating means for discriminating whether any one of the standard cassette accommodated and the high performance cassette containing the high performance magnetic tape is mounted in the apparatus, and when the standard cassette is discriminated, the input video signal is inputted. The standard recording mode in which the luminance signal separated from the FM carrier is FM-modulated at the first carrier frequency and recorded, and when the high-performance cassette is discriminated, the luminance signal is set to the second carrier frequency higher than the first carrier frequency. Is a recording system in a high-performance recording mode in which FM modulation is performed for recording, and the reproducing system supplies a reproduced signal reproduced from the magnetic tape to a luminance signal reproducing system. For separating the luminance reproduction signal relating to the luminance signal and the color reproduction signal relating to the color signal to be supplied to the color signal reproducing system, wherein the luminance signal reproducing system After passing through at least the amplitude control means for controlling the amplitude of the input signal to a predetermined value and outputting it, it is determined whether the magnetic tape is recorded in the standard recording mode or the high performance recording mode based on the frequency component. When it is determined that the magnetic tape is recorded in the standard recording mode, FM demodulation corresponding to the first carrier frequency is performed, and the magnetic tape is recorded in the high performance recording mode. A video signal magnetic recording / reproducing apparatus, characterized in that the reproducing system is configured so as to perform FM demodulation corresponding to the second carrier frequency when it is determined that the signal is present.