JPS60837B2 - Disc recording or playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc recording or reproducing apparatus for recording or reproducing information signals including synchronization signals using a disc.

Devices for recording or reproducing video signals using lasers have already been developed.

FIG. 1 is a schematic plan view showing a conventional video disc for optical reproduction.This disc 1 is provided with a composite video signal (for example, NT
SC color television signal) is recorded. The composite video signal is displayed at one point on the television screen as shown in Figure 2.
Each field has a vertical planking period, that is, a vertical line erasing period TB, and is recorded so that one fill is recorded in half a turn of disk 1 and one frame is formed in one turn of disk 1. In the area shown, the horizontal blanking period portions 3 and 4 appear.The horizontal blanking period portions 3 and 4 are equivalent to one horizontal scanning time of 63.5 French seconds. The pulse period T corresponds to the vertical blanking period TB consisting of the vertical synchronization pulse period 8r2 of the worm day, the equivalent pulse period T3 of the milk day, and the horizontal synchronization pulse period T4 of the 12th day. A signal is recorded.Usually, a composite video signal is FM modulated and then recorded in bits (grooves) as shown in FIG.

That is, recording is performed by projecting a modulated light beam onto the transparent resin layer 5 constituting the disc and forming bits 6 corresponding to the FM modulated wave in a predetermined track form. For example, the width of the bit is about lr, and the depth of the bit is about 1/4 inch.
The length of the bit differs depending on the inside and outside of the disk, and also depends on the frequency of the FM modulation wave, for example, 1.5 to 6 bits. Reference numeral 7a denotes a light reflecting surface provided after the bit formation, and is essential for reading recorded signals using reflection of light.

7b is a protective film. When reading a signal from a video disc as described above, the center engagement hole 8 is engaged with the ball of the turntable, the disc is fixed to the turntable with a clamper, and the disc 1 is rotated at a constant speed.

Further, by gradually sending the reproducing light beam 9 in the radial direction of the disc, the track 2 is sequentially scanned by the light beam 9, and reflected light 10 from the disc is detected. reflected light 1
Since the 0' bit changes depending on the presence or absence of the bit, the recorded signal can be determined by the change in the reflected light. By the way, when recording an information signal including a synchronization signal such as a composite video signal on a disc, there are cases where it is desired to align the synchronization signal at a certain angular position on the disc.

Further, during reproduction, there are cases where it is desired to obtain a reproduction output by matching the phase of the synchronization signal in the disc and the external reference period signal. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a disk recording or reproducing apparatus that can perform recording or reproducing while maintaining a constant phase relationship with a reference periodic signal.

To achieve the above object, the present invention provides a recording medium disk having a detected portion at a predetermined rotation angle position, a turntable that supports the disk, a motor that rotates the turntable, and a motor that detects the detected portion. a disc rotational angular position detection device that sends out a disc rotational angular position signal; a scanner that records information signals including a synchronization signal on the disc or reproduces them from the disc; and between the disc and the scanner. a feeding device for producing a relative feeding movement in the radial direction of the disk; a reference periodic signal generator for generating a reference periodic signal; and the disk rotational angular position signal obtained from the rotational angular position detection device and the reference. Disc recording or reproduction characterized by comprising a phase comparison control circuit that compares the phase with the reference periodic signal obtained from a periodic signal generator and controls the motor so that the phase difference becomes zero. It is related to equipment.

In the above invention, since the detected part for detecting the rotation angle position is provided directly on the recording medium disk, recording or reproduction is stopped midway through the disk, the disk is removed from the turntable, and the disk is mounted on the turntable again. When recording or reproducing is started, even if the angular positional relationship between the disc and the turntable changes, the predetermined rotational angular position of the disc can be detected regardless of the change in the positional relationship between the two.

As a result, at the time of recording, it is possible to record the synchronization signal aligned with the constant rotational angle position of the disk despite the interruption of recording. Furthermore, during playback, the positional relationship between the synchronizing signal on the disc and the detected part can always be kept constant.
Embodiments of the present invention will be described below with reference to the drawings.

4 to 6 show a video disc device according to a first embodiment of the present invention. On the video disk 11 used in this video disk device, as in the conventional disk shown in FIG. It is something to be regenerated. The difference from the disk 1 in FIG. 1 is that the disk 1
A detection target section 13 is provided for detecting a fixed angular position of. Note that this detected portion 13 is provided at only one location corresponding to one of the two bright line blanking period portions 3 obtained in one frame, and in this embodiment, a non-reflective object is attached. ing. A motor 15 is directly connected to a turntable 14 for rotating the disk 11, and the disk 11 and turntable 14 are rotated, for example, by
It is configured to rotate once at c. Reference numeral 16 denotes a clamper that fixes the disk 11 to the turnteafle 14.

Reference numeral 17 denotes a disk rotation angle position detection device, which in this embodiment includes a light source that projects light onto the detected section 13 and a detected section 1.
3 and a light-receiving element that detects the reflection state at 3.

Reference numeral 18 denotes a phase comparison control circuit, which uses a phase comparator to compare the phases of the rotation angle position detection signal obtained from the rotation angle position detection device 17 and the reference period signal obtained from the reference period signal generator 19, and calculates the phase difference. This is a circuit that controls the motor 15 at a constant speed so that the value becomes zero.

For example, one of the composite video signals is output from the reference period signal generator 19.
Pulses are generated at a period of 1/3 $ec corresponding to the frame interval. Reference numeral 20 denotes a recording or reproducing scanner, which projects a light beam onto the tracks of the disk 11 to record or reproduce signals.

The scanner 20 is arranged so as to be gradually fed in the radial direction of the disk 11 by a threaded rod 21 and a motor 22 that constitute a radial feeding device. FIG. 6 shows an optical system device 23 constituting a recording or reproducing scanner 20, with some parts omitted.
During reproduction, the light beam emitted from the helium neon laser light source 24 passes through the polarizing prism 2.
5, 1'4 polarizing plate 26, mirror 27, rotating mirror 28
, and is projected onto the track of the disk via the beam focusing device 29, and the reflected light passes through the beam focusing device 29, the rotating/mirror 28, the mirror 27, the 1'4 input polarizing plate 26, and the polarizing prism 25. The light reaches the photoelectric detection element 30, where it is converted into an electric signal, and is configured to project a modulated light beam during recording.

Although not shown, a rotating device having a similar configuration to a galvanometer is provided to rotate the rotating mirror 28, and the rotating mirror 28 is rotated based on a signal provided from the beam displacement control circuit 31. 28 is rotated to displace the light beam 9 in the radial direction of the disk. Further, in order to perform tracking during scanning, the rotating mirror 28 is controlled by a tracking signal. Since this optical system device 23 is non-rotatably guided in the disk radial direction by the seal 32, when the threaded rod 21 rotates, it advances and retreats in the disk radial direction. In FIG. 5, a rotation angle position detection signal generated from the detection device 17 is input to the beam displacement control circuit 31, and a mode setting signal is input from the command signal circuit 33, and a track switching signal is generated. It is configured as follows.

This track switching signal is a signal for rotating the rotating mirror 28 in synchronization with the rotation angle position detection signal. 3
4 is a signal processing circuit which converts the signal detected by the scanner 20 into, for example, an NTSC color television signal.
When recording or reproducing data in a video disc device configured as described above, the disc 11 is rotated at a constant speed, and the scanning element 20 and the scanning light beam 9 are gradually sent in the radial direction of the disc. by spiral track 2
Scan in a spiral.

As a result, during recording, recording is made in accordance with the recording signal, and during reproduction, reflected light power is obtained that corresponds to the presence or absence of bits, making it possible to record or reproduce a predetermined composite video signal. At this time, constant speed rotation control of the disk 11 is performed based on a rotational angular position detection signal obtained from the disk rotational angular position detection device 17. That is, each time the disk 11 rotates, the non-reflective detected part 13 passes over the rotational angular position detection device 17, and each time the detected part 13 passes, the input level of the light receiving element decreases, and the rotational angular position A detection signal is generated. As shown in FIG. 3, there is a reflective surface 7 in the region other than the detected part 13, so the detection device 17 is in a light receiving state and can clearly distinguish and detect the detected part 13. When this device is used for reproduction and a still image is desired to be obtained, a still image mode setting command signal is issued from the command signal circuit 33.

As a result, the feeding of the pickup 20 and the scanning light beam 9 by the screw rod 21 is stopped, and a rotating mirror control signal for switching the scanning track is generated from the displacement control circuit 31 in synchronization with the generation of the rotation angle position detection signal. , which is attached to a coil for rotationally displacing the rotating mirror 28,
Rotating mirror 28 rotates. The rotation of this rotating mirror causes the light beam to move to the adjacent track. That is, it moves from point B to point A in FIG. This cutting of the scanning track from point B to point A is performed in synchronization with the rotation detection pulse signal, and is performed during the vertical female line erasure period portion 3. That is, since the rotation angle position detection signal is generated every time the vertical blanking period portion 3 passes, the scanning track cutting signal is generated in synchronization with the vertical blanking period portion 3, and the vertical blanking period portion 3 is generated. In step 3, the scanning section is changed using a light beam. When one round of scanning from point A to point B is completed and point B is reached again, the rotation angle position detection signal is generated again, and the rotation angle position detection signal is again generated from point B to point A.
A light beam moves over a point and scans it repeatedly. I just talked about the scanning track cut in the still image mode,
Track switching between the quick motion image mode and the slow motion image mode is similarly performed during the vertical female line erasure period portion 3 in synchronization with the rotation detection pulse signal. When recording with this apparatus, for example, a light beam modulated with a composite video signal is projected onto the disk 11.

At this time, one of the composite video signals is output from the reference period signal generator 19.
Assuming that the reference period signal is generated at 1'3 $ec corresponding to the frame interval, the recorded portion 3 of the direct blanking period of the composite video signal and the detected portion provided at a constant angular position on the disk 11 13 can always be maintained at a constant angular positional relationship. Therefore, regardless of whether recording is interrupted or not, the recorded portion 3 of the vertical female line erasing period is aligned at one angular position on the circumference. Next, FIGS. 7 and 8 showing a second embodiment of the present invention will be described.

However, in this example and the examples described below, the first
The same reference numerals are given to the parts common to those in the embodiment described above, and the explanation thereof will be omitted. The disk 41 in this embodiment is the eighth disk.
As shown in the figure, it has concentric tracks 2a, and is used to record or reproduce a composite video signal so that one frame corresponds to one round. In this video disk device, the scanning track is switched every rotation to proceed with recording or reproduction. Now, if a normal recording or reproduction signal is sent from the command signal circuit 33, a rotation angle position detection signal synchronized with the blank blanking period is generated based on the detection of the detected part 13 by the detection device 17, and this generation Each time, a track enable signal is applied from the beam displacement control circuit 31 to the motor 22, and the scanning element 20 and the scanning light beam 9 are displaced by one track, for example from point A to point B, and then scan the next track. will be held. FIG. 9 shows a third embodiment of the present invention.

In this video disk device, AND gate 51
is newly provided, to which the rotation angle position detection signal obtained from the detection device 17 and the vertical synchronization pulse signal separated from the reproduced composite video signal obtained from the disk 11 are input. Therefore, the scanning track switching signal is generated only when both signals are input, and the scanning track is switched. Therefore, scanning track switching control can be performed more reliably. FIG. 10 shows a fourth embodiment of the present invention.

In this embodiment, the detected portions 13 are provided at a plurality of locations on the same circumference, and a plurality of rotation angle position detection signals are generated during one rotation of the disk. This disc 6
1 is used in a video disc device as shown in FIG. However, when using this disk 61, the oscillation frequency of the reference period signal generator 19 must be equal to the frequency of the rotation detection pulse signal. Also, AND gate 5
1 must be input with the vertical synchronizing pulse signal divided by 1'2. With this configuration, it becomes possible to control the rotation of the disk more accurately. that's all,
Although the embodiments of the present invention have been described, the present invention is not limited to the above embodiments, but can be further modified.

For example, the detected portion 13 may not be provided inside the disk 11 but may be provided in an outer non-recording area or the like. In short, any location is acceptable as long as the rotational angular position can be detected. In addition, in the embodiment, a black tape is pasted to provide the non-reflective detection area 13, but an area with a different reflectance from other areas is formed by printing, etching, forming bits with laser light, etc. This may be used as the detected part 13. Alternatively, the detected portion 13 may be a light-reflecting mirror castle, and the other portions may be non-reflecting mirror castles. Alternatively, the detected part 13 and the detection device 17 are not configured optically, but the detected part 13 is formed of a magnetic material,
The detection device 17 may perform magnetic detection to generate a rotation angle position detection signal. Further, the detected portion 13 may be provided corresponding to the horizontal retrace period. Alternatively, the scanning element 20 may be fed without using the threaded rod 21, but by locking the scanning element 20 to a line or strip and moving the line or strip in the radial direction of the disk. It is also applicable to the case where multiple frames are recorded per round or one frame is recorded over multiple rounds instead of recording one frame per round of the disc. Furthermore, in the embodiment, the light beam can be displaced by the threaded rod 21 and also by the rotating mirror 28, but the scanner is configured so that the light beam can be displaced by only one of them. Furthermore, the present invention is not limited to optical recording or reproducing, and can also be applied to other similar types of disk devices.

[Brief explanation of the drawing]

Fig. 1 is an explanatory plan view of a conventional video disc, Fig. 2 is a waveform diagram of a composite video signal recorded on the disc, Fig. 3 is an enlarged sectional view of the disc, and Figs. 4 is an explanatory plan view of a disc, FIG. 5 is a block diagram of a video disc device, FIG. 6 is a perspective view of a pickup optical system device, and FIG. 7 is a diagram showing a first embodiment of the invention.
The figure is a block diagram of a video disc device according to a second embodiment of the present invention, FIG. 8 is a plan view of a disc for use in the device of FIG. 7, and FIG. 9 is a block diagram of a video disc device according to a second embodiment of the present invention. FIG. 10 is a block diagram showing a video disc device according to a fourth embodiment of the present invention. FIG. 10 is a plan view of a video disc according to a fourth embodiment of the present invention. In addition, in the symbols used in the drawings, 2 is a truck,
3 and 4 are the vertical blanking period parts; 11 is the disk, 12
1 is a non-recording area, 13 is a detected portion, 17 is a detection device, 1
8 is a comparison control circuit, 19 is a reference period signal generator, 20 is a scanner, and 31 is a displacement control circuit. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 7 Figure 9 Figure 10

Claims (1)

[Claims] 1. A recording medium disk having a detected portion at a predetermined rotational angle position, a turntable that supports the disk, a motor that rotates the turntable, and detects the detected portion and sends out a disk rotational angle position signal. a disk rotational angular position detection device; a scanner for recording information signals including synchronization signals on or reproducing from the disk; and a relative radial feeding movement of the disk between the disk and the scanner. a reference period signal generator for generating a reference period signal;
A phase for comparing the phases of the disk rotation angle position signal obtained from the rotation angle position detection device and the reference period signal obtained from the reference period signal generator, and controlling the motor so that the phase difference becomes zero. A disc recording or reproducing device comprising: a comparison control circuit.