JPS6212292A - Image recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve picture quality and to facilitate the combination with other devices by mounting three optical heads on one carriage and recording or reproducing signals of R, G and B or three kinds of component signals obtained from them corresponding to respective heads. CONSTITUTION:A television camera 31 outputs component signals 32a-32c of R, B and G and a composite synchronizing signal 32d, which is added by addition stages 34a-34c after band control is performed by LPFs 33a-33c; and FM signals are obtained by FM modulation stages 18a-18c and applied to optical heads 2a-2c and they are modulated by a semiconductor laser and recorded. When reproduction is performed, FM signals are extracted by HPFs 23a-23c from optical head outputs 4a-4c and demodulated by FM demodulation stages 24a-24c to obtain playback signals 35a-35c. Consequently, a recorded FM signal has no chrominance signal at the low frequency side, so the band of the LPF 35a, etc., set widely correspondingly and a playback signal of this picture quality is obtained without dot disturbance nor cross color.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a recording and reproducing device using a disc-shaped information recording medium, and includes components such as KGB suitable for recording and reproducing high-quality images such as TV camera signals. This invention relates to a signal recording device.

[Background of the invention]

As a device for recording and reproducing image information such as images, documents, drawings, etc. on a disk-shaped information recording medium (hereinafter abbreviated as a disk) having a concentric circle or spiral guide track with an address code, for example, There is an optical recording and reproducing device. This device converges the original spot from a light source such as a laser beam onto the disk, and modulates the intensity of this optical output with a recording signal, thereby creating irregularities on the disk or changes in optical properties such as refractive index and reflectance. It is possible to record information such as a video signal in real time, and to reproduce the information by detecting the change in the optical characteristics. A conventional example of such a device will be explained with reference to FIG. In the figure, reference numeral 1 denotes a disk, which has a guide track provided with an address code as described above, and is rotated at 30 Hz by a disk motor rotation system (not shown). 2 is an optical head for recording and reproducing information, and 3 is a carriage for moving the optical head in the radial direction of the disk. The original head includes an optical system that converges the light of the semiconductor laser onto the information surface of the disk 1 as a minute optical spot for recording and reproduction, and detects the deviation of the focus direction and tracking direction of the spot from the normal state. , and an actuator that controls the spot. The low-frequency component of the original head output 4 is input to a tracking control system 5, and the output 6 controls the actuator to apply so-called tracking servo. Tracking address information output as a mid-range component of the original head output 4 is detected by an address detection/demodulation system 7, and the address of the track currently being tracked is recognized. The output of 7 is input to a system control system 8, where it is compared with an external command 9, and if necessary, the feed control system 10 and tracking control system 5 are controlled by the output of the system control system 8 to set the original spot to a predetermined position. It is located on the track. Note that 11 is a DC component of the tracking actuator control voltage.

With the above configuration, it is possible to select one or more predetermined tracks on the disc 1 to record and reproduce information.

Next, the recording operation of video information will be explained.

The output 13 of the television camera 12 is a composite NTSC signal and is the input signal of the device. The input signal 13 is separated into a luminance signal 15 and a chromaticity signal 16 by a luminance/chromaticity separation filter 14 . The luminance signal 15 becomes an FM signal in the FM modulation circuit 1B after being band-limited by the LPF 17 with a cutoff of about 4 M (z).On the other hand, the chromaticity signal 16 has a band width of about 4 M (z) and becomes an FM signal in the FM modulation circuit 1B.
After the band is limited by the PF 19, the color frequency conversion circuit 20 converts the carrier frequency from approximately 8 MHz to approximately 0.6 MHz. The outputs of the FM modulation circuit 18 and the color frequency conversion circuit 20 are added together in an addition stage 21, and then passed through a laser drive stage 22 where the intensity of the laser included in the original head 2 is modulated and recording is performed. In this embodiment, information is recorded using local changes in reflectance due to the thermal effect of the laser source.

Next, the playback operation will be explained. Reproduction is performed by detecting the local reflectance change using a constant weak laser source. That is, the original head output 4 is modulated by this change,
A luminance FM signal is extracted from the output using HPF25, and FM
A reproduced luminance signal 25 is obtained by the demodulation system 24. Also BP
Extract low frequency conversion color signal by F26, color frequency recovery stage 2
7, the reproduced color signal 28 of the original color frequency is obtained, and addition 2
At stage 29, the reproduced color signal 28 and the aforementioned reproduced luminance signal 25 are added to obtain a reproduced video signal 50.

In the above-mentioned conventional technology, it is difficult to obtain sufficient bandwidth for both brightness and chromaticity (and it is easy to cause dot interference and cross-color), so it is difficult to achieve ambidextrous image quality, especially when dealing with a wide range of applications for such devices. Furthermore, when used with other equipment, component signals such as KGB signals are often preferable to composite signals such as composite NTSC signals (in such cases, conventional equipment Then we needed a decoder.

Note that Nati
onal Technical Report Vo.
1, 28 No. 5 June 1982.

[Purpose of the invention]

The purpose of the present invention is to eliminate the problems of the prior art described above.
An object of the present invention is to provide an image recording and reproducing device that has high image quality and is convenient for connection with other devices.

[Summary of the invention]

In order to achieve the above object, the present invention employs a component signal recording/reproducing method in place of the conventional composite signal, and also provides a new technique such as the first order to facilitate its realization. That is, (1) a plurality of optical heads are arranged on the same carriage to realize a small, low-cost optical head feeding system.

(2) The outer peripheral side of the disk is configured to be used for recording and reproducing signals with a wide required band, and overall high image quality is achieved.

(3) Using the track address signal, control is performed so that the corresponding component signals are appropriately combined.

(4) A plurality of required control system element circuit systems can be shared in a time-sharing manner, making it possible to downsize and reduce costs.

[Embodiments of the invention]

An embodiment of the present invention will be explained with reference to the first button.

In the figures, parts with the same numbers as those in Figure 1 or with the same numbers with suffixes basically have the same functions as the corresponding parts in Figure 1, so explanations will be omitted unless it is particularly necessary. .

31 are R, B, and G component signals 52 a
+32b, 32c and a composite synchronization signal 52d. In order to make the explanation easier to understand, we will first explain the signal flow of SUFFIX@6". After removing the band side at 32a Y L P F' 334, a synchronizing signal is added at addition stage 54th, and then the FM modulation stage 18
The signal is converted into an F'M signal at step a, passed through the laser drive stage 224, and is applied to the original head 2a, whereupon the 2cL semiconductor laser is modulated to perform recording. Also, playback is performed from the optical head output 44 to HP F.
The FM signal is extracted at step 234 and demodulated at an FM demodulation stage 244 to obtain a reproduced signal 35a. In this case, the reproduced signal 354 is a signal accompanied by a synchronization signal. suffix ″b
The same applies to the signal flow of "@IC1".

Unlike the conventional example shown in Figure 2, there is no color signal on the low frequency side of the recording FM signal, so the band of the LPF536 etc. can be set correspondingly wider, and dot interference and cross color do not occur, resulting in high image quality. It is possible to obtain a reproduced signal.

The TV camera output signals 324 to 32c are NTSC
These signals have a wider band than the video signal, and each signal has a resolution of approximately 600 lines or more.

As shown in the figure, there are three optical heads 24, 2b.

2C are mounted on the same carriage 3, all the heads can be moved in the radial direction by one feed control system 10, resulting in a small size and low cost.

The total number of effective tracks on disk 1 is 24,000, and the original heads 21 to 2c are used to record tracks at addresses 1, 8001, etc.
One set of information is recorded and played back at address 16001. In this way, the address detection and demodulation systems 7a to 7 detect the address of each track so that recording and playback can be performed correctly at a predetermined address.
c, the system control system 8 judges and processes the above-mentioned feed control system 10 and tracking control system 5α to 5C.
is under control.

Figure 3 is an explanatory view of the main parts of the second embodiment of the present invention. In the figure, the parts with the same numbers as those in Figure 2 are basically the same functions as the corresponding parts in Figure 2, so the explanation will be omitted unless particularly necessary.

In the figure 3, 36 is the RRG component signal 32432C
This is a matrix circuit that obtains Q, I, and Y component signals 374 to 57c from. It's well known.

(Correspondingly, the bands of LPF 38a to 38c also become wider in order.The wider the required band, the wider the transmission band is located on the outer periphery side.) It is configured to record and play with an optical head.39
is an inverse matrix circuit that obtains B, B, G signals aOa to 4OC and a composite synchronization signal 40d from QIY.

With the above configuration, it is possible to rationally utilize the difference between the inner and outer circumferences of the transmission band characteristics unique to the disc, and it is possible to reproduce a reproduced image of higher quality.

Figure 4 is an explanatory view of the main parts of the third embodiment of the present invention. In the figures, the parts with the same numbers as in Figure 1 are basically the same functions as the corresponding parts in Figure 1, so unless there is a particular need,
The explanation will be omitted here.

In this embodiment, a system control system 80 with expanded functions consists of three tracking control systems and most of the address detection and demodulation systems, a Φ/L converter, a microprocessor, etc.
This is an attempt to simplify the circuit. That is, the SD95Dc is an error detection section of the tracking control system, and its output is input to the system control system 80 and applied as a control signal to the tracking actuators of the signal processing and restoration heads 24 to 2c. Furthermore, system control system 8
0 achieves system simplification by performing time-sharing processing on three systems.

Reference numerals 7Da to 7Dc designate address detection units, which, like the tracking control system, are configured so that subsequent processing is performed by the system control system 80. In addition to the above, it is obvious that a similar configuration may be used for the focus control system, etc.

Figure 5 is an explanatory view of the main parts of the fourth embodiment of the present invention. In this figure, the parts with the same reference numerals as those in Figure 1 have basically the same functions as the corresponding parts in Figure 1, so their explanation will be omitted here unless it is particularly necessary.

This embodiment is provided with an original head for audio signals.

With this configuration, for example, it is possible to output approximately 10 seconds of audio for one still image.

In the figure, 41 is an audio source such as a tape recorder, and its output is compressed in the time axis by a time axis compression system 42 consisting of memory, D/A, etc., and converted into a signal with almost the same bandwidth as the video signal. , FM modulated by FM modulation stage 18d and laser drive 2
2d, input the information back to Kudo 2d, and record it. During playback, HP F 2sd is output from the output 4d of the optical head 2d.
The FM signal is extracted at the FM demodulation stage 24d, and the FM signal is demodulated at the FM demodulation stage 24d.
The time axis is expanded by the time axis expansion system 45 and the audio reproduction signal 44
I am getting . The parts whose explanation is omitted are the same as in Figure 1.

[Effects of the Invention] According to the present invention, recording and reproducing component signals in a disk-type recording and reproducing device can be easily realized, and high image quality of the reproduced signal and multifunctionality of the device can be realized with a small size and low cost.

[Brief explanation of the drawing]

Figure 1 is a block diagram of an embodiment of the present invention, Figure 2 is an explanatory diagram of the prior art, Figure 3 is a block diagram of an embodiment of the present invention, and Figure i'4 is the same (the present invention, Figure 5 is a block diagram of the embodiment of the present invention No. 4. 1... Disc, 3... Carriage, 5... Tracking control system, 7. ...Address detection demodulation system, 8...System control system, 10...Feeding control system, 31...R, GB output television camera. Agent Masu Masu Ogawa, male 1.' (1/ η
(Fig. 4)

Claims (1)

[Claims] 1. In a device that records and reproduces information on concentric circles or spiral tracks of a disc-shaped rotating recording medium, three optical heads are mounted on one carriage and RGB or three types of component signals obtained from it are output. An image recording/reproducing apparatus characterized in that the component signals are recorded and reproduced by being associated with each head.