JPH0194794A - Disk recording reproducing device - Google Patents

Abstract

PURPOSE:To obtain a video without flicker and to lengthen the recording time of a disk by making a recording track on the disk to be a V groove state and recording two TV signal reproducing a steroscopic image on two slopes being adjacent to this groove at a same time. CONSTITUTION:A recording film 1 reflects a laser beam and records the signal. A base 2 forms the V grooves 3 and 4 and it is the two slopes constituted by the said recording film 1 recording the signal. The recorded signal 5 is sometimes a hole (a pit) or sometimes an area forming a different reflection ratio according to the kinds of the recording film or a recording reproducing means. As the interval of a valley between the V grooves 3 and 4 is the same as an usual track pitch (a guard band does not exists), the recording is high density. Therefore, the recording time of the video disk recording the two signals needed for a stereoscopic television display system can be lengthened and the smooth video without flicker can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video disc device capable of effectively recording and reproducing stereoscopic television signals.

PRIOR TECHNOLOGY When reproducing stereoscopic images on a television screen, two television signals corresponding to the left and right visual field of a person are required for boat fishing.

Conventionally, two television signals 'f corresponding to the visual field of the left and right eyes are alternately projected on one screen every other field, and shutters placed in front of each left and right eye are opened and closed in synchronization with this. A method for obtaining stereoscopic images has been put into practical use, and video discs using this method are commercially available. However, a drawback of this method is that for each eye, the repetition frequency of the televised image becomes a bar of the original frequency, resulting in noticeable flicker. Therefore, a method has been proposed to reduce the flicker by electrically converting the image signal into a repetition frequency twice as high, but it is a pseudo method and cannot be called perfect.

In order to obtain a more complete stereoscopic screen, successive television images corresponding to the left and right eyes are optically combined into one screen, for example through horizontal and vertical polarization filters, respectively, and the corresponding polarization filters are applied to the eye fGilte. Projection television methods are also being considered.

Problems to be Solved by the Invention As explained in the prior art, two complete television signals are required to eliminate flickering on a television screen, but in order to obtain them, it is necessary to record them. Since the signal amount is completely doubled, the recording time for a video disc, for example, becomes A, and since two television signals are required at the same time, it is expected that the reproduction method will be extremely complicated. Ru.

In other words, there are two types of video discs currently in use:
Both VHD and laser discs have one video recording channel, so in order to obtain two continuous channels of video signals on these discs, for example, compress the time axis of the two video signals to A and record every other screen. It is easy to think of a method in which the channels are inserted alternately into one channel of video signal, and this is recorded on the VHD or laser disc. However, in this method, since the frequency band of the signal to be recorded is doubled, the relative speed between the disk and the pickup during recording and reproduction must also be doubled, and as a result, the recording time becomes short. Moreover, a signal processing circuit for compressing or expanding the time axis of the video signal is also required in the recording and reproducing apparatus, which causes problems such as increased cost.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a recording and reproducing apparatus using a video disc that can record a complete two-channel stereoscopic television video signal for a long time and does not require a complicated signal processing circuit. It is something.

Means for Solving All Problems The present invention provides a spirally formed track on an optical disk for recording or reproducing television signal.
It has a 2V-shaped groove, and is configured to simultaneously record or reproduce two television signals separately on two adjacent slopes of the V groove, and is configured to simultaneously record or reproduce two television signals as the two television signals. This is a disc recording and reproducing device characterized by using two television video signals.

Effect of the present invention With the above-described configuration, the recording track on the disk is formed into a V-groove shape, and two television signals for reproducing a stereoscopic image are simultaneously recorded on two adjacent slopes of this groove, and reproduced at the same time. It is designed to obtain two consecutive television video signals.

Example: Optical disks, which have been attracting attention in recent years as high-density, large-capacity memories, have a limit to narrowing the track pitch beyond a certain level because when trying to increase the capacity, crosstalk between tracks increases. . An optical disk having V-groove-shaped tracks has been proposed as a method of narrowing the track pitch until it becomes equal to the track width.

FIG. 1 shows an enlarged view of a radial cross section of an optical disk used in the present invention. Reference numeral 1 denotes a recording film that reflects laser light and records signals, 2 a base, and 3 and 4 two slopes formed of the recording film 1 forming V-grooves and recording signals. Reference numeral 6 indicates a recorded signal, which may be a hole (bit) or an area forming a different reflectance depending on the type of recording film and the recording/reproducing means. Here, the interval between the valleys of the V-groove is the same as the conventional track pitch (there is no guard band), resulting in high-density recording.

If the optical depth of the V-groove is expressed as a percentage of the wavelength of the laser used, one dimension of the diffracted light reflected from the original disk contains a signal from only one slope. Therefore, two laser beams f
Three separate television signals can be simultaneously recorded and reproduced by irradiating the adjacent slopes of the TV groove.

The detailed principles described above are described in the following references.

References: Yoshiya Takemura et al. “High-density, high-transfer rate recording and reproducing method for optical discs using V-grooves,” Proceedings of the 1985 National Conference of the Telecommunications Division of the Institute of Electronics and Communication Engineers, 5s-a.

P, 1-455 A specific configuration diagram of a stereoscopic television signal reproducing apparatus using the V-groove disk described above is shown in FIG. In the figure, reference numerals 10 and 11 respectively indicate pickup devices that convert optical signals from the slopes of the two V-grooves into electrical signals, and 12.1
3 is obtained from the pickup, fc, RF -FM
FM demodulators 1.14 and 15 for demodulating the reproduced signal into the original television signal are variable delay circuits for taking time axis fluctuations in the reproduced signal, and the amount of delay can be changed by a control signal supplied from the outside. It is. Reference numeral 16 denotes a time-base variation detection circuit that detects time-base variation, that is, jitter, in the reproduced television signal and performs feedback control on the variable delay circuits 14 and 15. Note that the relative time fluctuation between the two reproduced television signals is so small that it can be ignored, so as shown in the figure, detection is performed from only one signal, and a control signal based on this detection result is used to detect both signals. Channel jitter correction can be performed at the same time. 17
and 18 are two reproduced stereoscopic television signal output terminals.

Next, although omitted in FIG. 2, a correction method when there is a static time difference between two reproduced stereoscopic television signals will be described as a second embodiment with reference to FIG. 3.

A static time difference is caused by an error in the wave-like position of the laser beam spot during recording or reproduction, or an error in the electrical delay time of the two signal processing circuits between the signal output terminals 17 and 18 in Fig. 2. This is something that may occur regularly between two signals. In Figure 3, 14 to 18
is the same as in FIG. 2, so the explanation will be omitted. Reference numeral 19 denotes a time difference detection circuit that detects the time difference between two television signals.There are various possible methods for this, but one example is to detect a synchronization signal from each of the two television signals and compare the phases between both synchronization signals. A possible method is to perform this and output the phase difference signal. 2o is the variable delay circuit 14 using a voltage corresponding to the detected time difference as a control signal.
This is an adder circuit that adds a bias to the control signal. Since the control signal applied as the bias is static as described above, it is a low frequency signal almost like direct current.

Note that the circuits, devices, etc. shown in the blocks described above are all well-known, so detailed explanations will be omitted.

Furthermore, if it becomes necessary to view the reproduced signal of the 3D television signal reproducing device according to the present invention with a normal television device instead of a 3D television device, only one of the two output signals can be used. It is easily achievable.

Effects of the Invention According to the present invention, in addition to making it possible to lengthen the length of a video disc on which two television signals necessary for a stereoscopic television display system using binocular parallax are recorded, The television signal is completely continuous rather than imperfectly alternating fields, and has the advantage of providing smooth images without flicker.

Furthermore, the 3D video discs currently in use must be able to be displayed on regular non-3D screens.
In addition to the two-channel signal with alternating fields, an extra video signal is recorded on one channel so that continuous playback is possible, and this further reduces the recording time, but according to the present invention. As explained in the embodiment section, when displaying on a normal screen, it is sufficient to simply use the signal of one channel as is, and there is no need for any additional equipment, which has the effect of good compatibility. .

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, an explanatory diagram of a state in which signals are recorded on a V-groove disk, Fig. 2 is a configuration diagram of the embodiment of the invention, and Fig. 3 shows a second embodiment of the invention. FIG. 1... Recording film of an optical disc, 2... Pace, 3° 4... Two slopes forming a V-groove,
6...Recorded signal, 10.11...
・Pickup device, 12.13...FM demodulator, 14,15...Variable delay circuit, 16...
...Time axis variation detection device, 17°18...3D television signal output terminal, 19...Time difference detection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3

Claims (3)

[Claims] (1) A track on an optical disc for recording or reproducing television signals has a groove formed in a spiral shape, and two television signals are simultaneously recorded separately on two adjacent slopes of the V groove. Alternatively, a disk recording and reproducing apparatus characterized in that the two television signals are two television video signals for reproducing a stereoscopic image. (2) A claim characterized in that a time axis variation is detected from one of the two television signals, and the time axis variation of the two television signals is corrected using a control signal obtained by the detection. 2. The disc recording and reproducing device according to item 1. (3) The time difference between the two television signals is detected, and the control signal obtained by the detection is added as a bias to the control signal for time axis fluctuation correction of one of the two television signals. A disc recording and reproducing apparatus according to claim 2.