JPH0828856B2 - Different format video disc player - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual-use disc player capable of playing any video disc recorded with an information signal including composite video signals of different signal formats.

Background Art For example, a conventional example of a track jump control device in a video disc player for playing only an NTSC disc will be described with reference to FIG.

FIG. 5 is a block diagram showing an example of a track jump control device described in Japanese Patent Application No. 62-202441. Three beam spots obtained by converging a laser beam, that is, an information reading spot S ₁ and this spot. S ₁
In the relative movement with respect to the disc, a pair of preceding and following tracking information detection spots S ₂ and S ₃ are irradiated onto a recording track T of the disc from a pickup (not shown) in a positional relationship shown in the figure. . The reflected beams from the disk due to these beam spots enter the photoelectric conversion elements 1 to 3 incorporated in the pickup.

The photoelectric conversion element 1 is arranged so that each light receiving surface is divided into four by two straight lines which are orthogonal to each other, and is composed of four light receiving elements which are independent of each other, and the total output of these elements becomes a read RF signal. . The read RF signal is supplied to the demodulation circuit 13 and demodulated into a composite video signal. The demodulation circuit 13 supplies the composite video signal to the decoding circuit 14 and a video output terminal (not shown), and also supplies the vertical sync signal separated from the composite video signal to the jump pulse generation circuit 8. Decoding circuit 14
For demodulating the operation control information inserted in, for example, the vertical blanking portion (vertical blanking period) of the composite video signal and supplying the demodulated information to the controller 11.

On the other hand, the respective outputs of the photoelectric conversion elements 2 and 3 are supplied to the differential amplifier 4 and the difference between the two outputs is detected, and the difference output is the information reading spot S ₁ in the disk radial direction from the center line of the recording track T. The tracking error signal indicates the amount of deviation.

This tracking error signal is subjected to predetermined phase compensation in the equalizer circuit 5, and then becomes one input of the adder 7 via the loop switch 6. A drive pulse (jump pulse) generated by the jump pulse generation circuit 8 is applied to the other input of the adder 7. The output of the adder 7 is applied to the tracking actuator 10 via the low frequency equalizer circuit 9. The low frequency equalizer circuit 9 is an actuator
It is provided in order to increase the gain of the frequencies below the low resonance frequency f _{0 of} 10. Tracking actuator 10
During normal playing, the information reading spot S ₁ is biased in the radial direction of the disc by a direction and an amount corresponding to the polarity and level of the applied voltage, so that the spot S ₁ accurately follows the center line of the recording track T. Will be done. The circuits 2-7, 9 and 10 form a tracking servo loop.

As shown in FIG. 6, the jump pulse generating circuit 8 is a controller according to the outputs of monostable multivibrators (hereinafter, simply referred to as monostable multis) 8a and 8b to which a vertical synchronizing signal is supplied. The pulse generation circuit 8c generates a drive pulse signal having a pulse width and amplitude designated by 11.

The controller 11 is composed of, for example, a microcomputer, and when a jump command is issued from the operation unit 12, for example, opens the loop switch 6 and opens a jump pulse having a pulse width and amplitude corresponding to the number of tracks to jump. The jump pulse generating circuit 8 is controlled so as to generate. The performance control information is referred to when controlling the track jump.

A case where a special reproduction is performed by performing a track jump during the performance of a CAV (constant angular velocity) disc as shown in FIG. 7 with such a configuration will be described.

In the CAV disc, one screen (frame) composed of the first and second fields is recorded on one track, and the synchronization signals of each track are aligned in the radial direction and recorded. NT
For example, frame number codes are recorded in 16H (horizontal scanning) to 18H of the vertical blanking section of the SC type video disc, and performance control information such as picture stop codes and chapter number codes are recorded in 279H to 281H. There is. For PAL video discs, 16H-18H
Performance control information is recorded in 329H to 331H.

For example, when a triple speed reproduction is commanded from the operation unit 12, the controller 11 sequentially turns on a spindle servo, a focus servo, a tracking servo, etc., which are not shown. When each servo locks, the demodulation circuit 13 demodulates the read RF signal supplied from the light receiving element 1 and outputs a composite video signal as shown in FIG. Further, a vertical synchronizing signal as shown in FIG. 8B separated from the composite video signal is supplied to the monostable multis 8a and 8b. Monostable multi 8a
Generates a high level output as shown in FIG. 8C in response to the fall of the vertical synchronizing signal, and continues until before the control data portion. The monostable multi 8b generates a high level output as shown in FIG. 8D in response to the fall of the vertical synchronizing signal, and continues until before the next vertical synchronizing signal. When the pulse generating circuit 8c is supplied with a command to generate a drive pulse from the controller 11, the pulse generating circuit 8c generates a drive pulse as shown in FIG. 8 (E) in response to the fall of the outputs of both monostable multis. The tracking actuator 10 is driven by the positive portion of this drive pulse.
Is biased and controlled by the negative part. The switch 6 is opened by the controller 11 while the drive pulse is being supplied. The drive pulse is transmitted to the tracking actuator via the adder 7 and the low frequency equalizer 9.
When supplied to 10, the single-track jump is performed by the drive pulse, and the single-track jump is executed twice in the vertical blanking interval to perform the normal triple speed performance. Along with the track jump, the level of the tracking error signal also changes as shown in FIG.

In this way, the start timing of the track jump is appropriately controlled to enable special reproduction without affecting the reproduction screen.

By the way, the applicant is developing a different-type video disc player for playing different video discs recorded by the NTSC system, the PAL system or the like in different signal formats with one disc player.

In such a dual-use disc player, if the signal format recorded on the video disc is different, the number of scanning lines on the television screen is different. Therefore, the recording signal format is automatically discriminated and the signal format and the content of the special reproduction command are corresponded. It is necessary to change the set time of the monostable multi.

However, it is difficult to accurately and freely set the time constant of the monostable multi in accordance with the signal format, and the track jump position in the vertical blanking section due to variations in the timekeeping of the monostable multi, uneven rotation of the disk, etc. Fluctuations may occur, which may cause an equivalent pulse of the demodulated composite video signal, a loss of control data, a disorder of the playback screen, and the like.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a heterogeneous video disc dual-purpose player capable of playing any video disc recorded with video signals of different signal formats and capable of performing an accurate jump operation. .

In order to achieve the above object, a signal format discriminating means for discriminating a signal format of a composite video signal read from a video disc through a pickup in a disc player for dual-use video discs and generating a discriminating signal, and the composite video. A synchronizing signal separating means for separating a vertical synchronizing signal from a signal, a rotating synchronizing signal generating means for generating a rotating synchronizing signal at every predetermined rotation angle of the information recording disk, and the rotating synchronization in response to each of the vertical synchronizing signals. Integration means for starting integration of signals, comparison reference value setting means for outputting a comparison reference value corresponding to the discrimination signal, and comparison for generating a detection signal based on a comparison result of the integration value and the comparison reference value Means and a track jumping operation of jumping over the read track by picking up the pickup according to the detection signal. Characterized by comprising a pickup driving means occupies the.

Example Hereinafter, an example of the present invention will be described with reference to the drawings.

In the block diagram of the embodiment shown in FIG. 1, the portions corresponding to those in FIG. 5 are designated by the same reference numerals, and the description of such portions will be omitted.

In FIG. 1, the demodulation circuit 13a demodulates the composite RF signal as shown in FIG. 4A from the read RF signal and supplies it to the sync signal separation circuit 13b, the decoding circuit 14 and a video output terminal (not shown). The sync signal separation circuit 13b separates horizontal and vertical sync signals as shown in FIGS. 4C and 4B from the composite video signal and supplies them to the jump pulse generation circuit 80 and the signal format discrimination circuit 90.

When the CAV disc is played, the horizontal and vertical sync signals are output from the sync signal separation circuit 13b corresponding to the rotation angle of the disc. The synchronization signal separation circuit 13b corresponds to the synchronization signal separation means and the rotation synchronization signal generation means.

FIG. 2 shows the configuration of the signal format discrimination circuit 90.
The signal format discrimination circuit 90 plays a role of distinguishing between the NTSC system signal format and the PAL system signal format, and the horizontal and vertical synchronizing signals are supplied to the integrating input terminal and the reset input terminal of the counter 91, respectively. The counter 91 is reset in response to the falling edge of the vertical synchronization signal and starts integration. The integrated value of the counter 91 is supplied to the data latch circuit 92. The data latch circuit 92 holds the integrated value immediately before the counter is reset, and supplies the number of horizontal synchronizing signals sandwiched by the vertical synchronizing signals to the comparator 93. The comparator 93 compares the integrated value with the value held in the data latch circuit 94 and supplies a signal determination output to the controller 11a. For example, the data latch circuit 94 includes a controller 11a
Is set to 280. Since the number of scanning lines in one field is 262.5 in the NTSC system and 312.5 in the PAL system,
The integrated value is larger or smaller than the reference value 280, and both can be distinguished.

It is also possible to record a signal representing a signal system in the control data (performance information) of the composite video signal, decode this by the decoding circuit 14 and supply it to the controller 11a to determine the signal system.

FIG. 2 shows a configuration example of the jump pulse generation circuit 80. The horizontal and vertical synchronizing signals are supplied to the integrating input terminal and the reset input terminal of the integrating counter 81, respectively. In addition,
The horizontal sync signal may include an equivalent pulse in the equivalent pulse addition portion of the composite video signal. The integrated value of the counter 81 as shown in FIG.
It is supplied to the comparison input terminals of 82 and 83, respectively. Comparator 82 and
83 Data latch circuits 84 and 85 are provided at each comparison reference input terminal.
Comparative reference values are supplied separately from. The comparison reference value held by each data latch circuit is set corresponding to the signal format determined by the controller 11a.

In addition to the functions of the conventional controller 11, the controller 11a has a function of setting and controlling an arbitrary comparison reference value in the data latch circuits 84, 85 and 92. In the NTSC composite video signal, the number of scanning lines is 525 lines per frame (262.5 lines / field).
The number of scanning lines is 1 in the PAL composite video signal.
Since there are 625 lines (312.5 lines / field) per frame, for example, 280 is initialized in the data latch circuit 94, the signal format is discriminated by the output of the comparator 93, and the data latch circuits 84 and 85 demodulate the composite video. The comparison reference value is set according to the signal type and the content of the special reproduction command. For example, after the NTSC system disk is placed on the turntable, the data latch circuit 82 inserts the equivalent pulse and the control data from the vertical synchronizing signal in response to the designation of the normal triple speed reproduction mode from the operation unit 12. The number V ₁ of horizontal sync signals up to the selected area is set, and the number V ₂ of horizontal sync signals from the vertical sync signal to the horizontal scan before the next vertical blanking is set in the data latch circuit 83.

The comparator 82 compares the integrated value with the comparison reference value V _1, and when both values match, a first detection signal as shown in FIG. 4 (E) is generated. The comparator 83 compares the integrated value with the comparison reference value V _2, and when both values match, it generates a second detection signal as shown in FIG. 4 (F). The first and second detection signals are supplied to the pulse generation circuit 8c. The outputs of the comparators 82 and 83 are reset by supplying the vertical synchronizing signal.

The pulse generation circuit 8c responds to the first and second detection signals by
A drive pulse having a width and amplitude designated by the controller 11 as shown in FIG. 4 (G) is generated and supplied to the adder 7. During the supply of this drive pulse, the switch 6 is opened by the controller 11a. When the drive pulse is supplied to the tracking actuator 10 via the adder 7 and the low frequency equalizer 9, the actuator 10 is driven and the information reading spot jumps to the adjacent track. At this time, the tracking error signal output from the differential amplifier 4 is as shown in FIG. Other configurations are similar to those of the circuit shown in FIG.

In this way, by counting the horizontal synchronization signals according to the rotation angle of the disc from the supply of the vertical synchronization signal to determine the track jump position in the vertical blanking period, the difference in the signal format recorded on the disc and the rotation of the disc It is possible to accurately detect the jump timing on the time axis of the composite video signal without being affected by unevenness and to perform stable special reproduction.

FIG. 4 (I) shows a drive pulse generation state when performing still image reproduction. In the still image reproduction mode, one track jump is made at the final scanning portion of the second field image which is not displayed on the TV screen. Therefore, the controller 11a sets a reference value corresponding to the jump position in one of the data latch circuits of the jump pulse generation circuit 80, and sets a command in which the comparator does not generate an output in the other data latch circuit. .

In the above embodiment, the horizontal synchronizing signal is used as the signal synchronized with the rotation of the disk, but for example, the output pulse of the PLL oscillator synchronized with the rotation of the spindle motor that rotationally drives the disk may be used. Of.

As the signal format discriminating means, the recording signal format is discriminated by discriminating the difference in the control data insertion position using the PAL window and NTSC window proposed by the applicant in Japanese Patent Application No. 63-23344. Alternatively, a method proposed by Japanese Patent Application No. 63-12240 to detect the presence or absence of an accompanying signal according to the signal format and determine the recording signal format can be used. It can also be applied to SECAM video disc performances.

As described above, in the dual-use video disc player of the present invention, the signal format of the composite video signal recorded on the video disc is automatically discriminated, and the discriminated signal format and the contents of the special reproduction command are given. Select a reference value corresponding to, obtain a signal corresponding to a predetermined rotation angle of the disk such as a horizontal synchronization signal, and integrate it, while the vertical synchronization signal indicating the reference position on the time axis of the composite video signal performs the integration. The value is reset, and the track jump is started when the integrated value and the above-mentioned reference value indicating the position on the time axis of the composite video signal to be jumped coincide with each other. Therefore, even for a video disc having a different signal format. Special reproduction is performed accurately, which is preferable.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a constitution of a signal format discrimination circuit 90, and FIG. 3 is a block showing a constitution example of a jump pulse generation circuit 80. FIG. 4 and FIG. 4 show the jump pulse generating circuit 80.
FIG. 5 is a block diagram showing a conventional example, FIG. 6 is a block diagram showing a configuration example of the jump pulse generating circuit 8, and FIG. 7 is a diagram for explaining a CAV disc. FIG. 8 and FIG. 8 are diagrams for explaining the operation of the jump pulse generating circuit 8. Description of symbols of main parts 1-3 ... photoelectric conversion element 6 ... loop switch 8,80 ... jump pulse generation circuit 9 ... low-frequency equalizer circuit 10 ... tracking actuator 11, 11a ... controller 13, 13a ... … Demodulation circuit 13b… Synchronous signal separation circuit 90… Signal format discrimination circuit

Claims (5)

[Claims] 1. A disc player for dual-use video discs of different systems, comprising signal format discriminating means for discriminating a signal format of a composite video signal read from a video disc through a pickup and generating a discrimination signal, said composite video signal. A synchronizing signal separating means for separating a vertical synchronizing signal from the vertical synchronizing signal, a rotating synchronizing signal generating means for generating a rotating synchronizing signal for each predetermined rotation angle of the information recording disk, and the rotating synchronizing signal in response to each of the vertical synchronizing signals. Integrating means for starting the integration of, a comparison reference value setting means for outputting a comparison reference value corresponding to the discrimination signal, and a comparing means for generating a detection signal based on the comparison result of the integration value and the comparison reference value. According to the detection signal, the pickup picks up the track and jumps over the read track. A video disc player comprising a backup drive means. 2. The rotation synchronizing signal generating means comprises a horizontal synchronizing signal separating circuit for separating a horizontal synchronizing signal from the composite video signal and outputting the separated horizontal synchronizing signal as the rotating synchronizing signal. Video disc player. 3. The signal format is NTSC or PAL
3. The video disc player according to claim 2, wherein the signal format discriminating means discriminates based on the number of the horizontal synchronizing signals sandwiched by the vertical synchronizing signals. 4. The video disc player according to claim 1, wherein the comparison reference value is set in correspondence with the signal format of the reproduced composite video signal and the number of tracks to be skipped. 5. The video disc player according to claim 1, wherein said signal format discriminating means discriminates a signal format of said composite video signal based on an identification code extracted from said composite video signal.