JPS5896474A - Video disc reproducer - Google Patents

Abstract

PURPOSE:To locate the generating position of a kick pulse at an upper or lower inconspicuous part of a screen, by controlling the generating position of the kick pulse at the outside of a vertical blanking period with time management in response to the number of pulses. CONSTITUTION:In the quick motion reproduction of a video disc reproducer, the position of a reproducing scanner 10 on a video signal is detected, the change in the track to be scanned with the scanner 10 overflowed from a vertical blanking period is done as near as possible at the vertical blanking period which can not disturb the signal detection within the vertical blanking period in the minimum interval surely changed by the required number, the position of noise due to track change on the receiver screen is arranged at the position at upper or lower position of the screen, not noticed, and the quick motion reproduction faster than the reproducing speed to be realized only with the track change of the scanner 10 for the vertical blanking period without remarkable deterioration of the receiver screen.

Description

DETAILED DESCRIPTION OF THE INVENTION In quick motion playback that is faster than quick motion playback obtained by changing the scan track of the playback scanner within the vertical blanking period, the present invention When changing the scanning track of the scanner, the position on the video signal of the scanning track change is determined by the playback speed, that is, the number of scanning tracks to be changed, and the scanning track change is performed as close as possible to the vertical blanking period. The present invention relates to a video disc playback device that performs video disc playback.

In a video disc playback device, by changing the track to be scanned by the playback scanner within the vertical blanking period, quick motion playback without noise caused by video signal disturbance can be realized on the receiver screen. In the method of changing the track only within the blanking period,
There is a limit to the speed of quick motion playback. On the other hand, in Quick Morph 11 playback, if the track change is performed outside the vertical blanking period, the video and signal will be disrupted and noise will appear on the receiver screen during the track change period and several hundred microseconds. Its location significantly impairs the quality of the IT2 receiver screen.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a video disc playback device that can increase quick motion playback speed without substantially degrading the quality of the receiver screen.

A feature of the present invention is that during quick motion playback of a video disc playback device, by detecting the position of the playback scanner on the video signal, the scanning of the playback scanner that cannot enter the vertical blanking period is stopped. The desired number of track changes should be made at the minimum interval to ensure the desired number of track changes, and as close to the vertical blanking period as possible without disturbing signal detection within the vertical blanking period, and the receiver screen A playback speed that can be achieved by moving the position of noise caused by track changes to an inconspicuous position at the top or bottom of one screen and changing the track of the playback scanner only during the vertical blanking period without significantly damaging the receiver screen. This allows for faster quick motion playback.

Hereinafter, the details of this invention will be explained according to examples.

FIG. 1 shows a block diagram of an embodiment of a video disc playback device that performs quick motor playback, and FIG. 2 shows a time chart for explaining the operation of the device shown in FIG.

This video disk playback device is a video disk playback device that plays back video information from a disc-shaped information recording medium 14 having a spiral information track, and has an actuator for driving an optical pickup to track the information track. a feeding circuit 18 that sends the reproducing scanner 10 in the radial direction of the information recording medium 14 as the scanning track of the reproducing scanner 10 changes; a tracking control circuit 12 for controlling the reproducing scanner 10 so as to follow a track to be scanned;
The difference in the radial position on the information recording medium 14 between the track to be scanned and the reproduction scanner 10 due to the change in the track to be scanned by the tracking control circuit 12 is within a range within which the tracking control circuit 12 can control the tracking. As shown in FIG.
4 in the radial direction Kl) The position of the reproduced scanner 10 on the video signal is determined based on the kick pulse generation circuit 9 that sends the signal rack by rack, and the periodic signal in the reproduced vertical synchronization signal or similar video signal. a timer counter 2 for detecting; a reproduction speed instruction circuit 6 for instructing the reproduction speed of the video information recorded on the information recording medium 14 and providing reproduction scanner feed speed information to the feeding circuit 18; a kick pulse generation trigger generation circuit 4 that continuously generates a kick pulse generation trigger signal at a period corresponding to the minimum time during which the scanner 10 can reliably change tracks and supplies the kick pulse generation trigger signal to the kick pulse generation circuit 9; It is necessary for the kick pulse generation trigger circuit 4 to generate a kick pulse generation trigger signal sequence for generating the number of kick pulse sequences necessary for changing tracks according to the reproduction speed based on the instructions from the reproduction speed instruction circuit 6. a timing setting circuit 7.8 for setting the period at a position closest to the vertical blanking period without impairing signal detection i within the vertical blanking period; and a timer window comparator 3 which activates the kick pulse generation trigger generation circuit 4'i when the output matches the kick pulse generation trigger generation circuit 4'i.

Next, this video disc playback device will be explained in detail.

Of the signals detected by the reproduction scanner 10.

Signals necessary for tracking control are extracted by the tracking control signal detection circuit 11 and sent to the tracking control circuit 1.
2, the reproduction scanner 10 is controlled so as to follow the track to be scanned. Furthermore, the reproduction speed information is sent from the reproduction speed instruction circuit 6 to the sending circuit 18, and the reproduction scanner 10 is scanned by the motor 17 in the radial direction on the disc-shaped information recording medium (video disk) 14. It is sent at a speed corresponding to the track change, and is appropriately slightly displaced in the radial direction on the information recording medium 14 according to a tracking error signal from the tracking control circuit 12, thereby ensuring track tracking of the reproducing scanner 10. On the other hand, a signal detected from the information recording medium 14 by the reproduction scanner 10 is applied to the demodulation circuit 13. The vertical synchronization signal a' separated by the vertical synchronization separation circuit 1 from the video signal demodulated by the demodulation circuit 13 activates the i-image counter 2 for detecting the position on the video signal of the reproduction scanner 10, and further activates the OR gate 5. Kick pulse generation circuit 9 throughout
is added as a trigger signal for kick pulse generation. On the other hand, the reproduction speed instruction circuit 6 instructs the reproduction speed, thereby changing the scanning track of the reproduction scanner 10, that is, the start time and end time of kick pulse generation based on the vertical synchronization signal a', respectively. Set in kick pulse generation timing setting circuit 7.8. The start time and the end time determine the generation of the kick pulse by the reproducing scanner lO.
When the kick pulses are generated at the minimum intervals that can reliably change the track, the kick pulses are generated as many times as the number of blanks depending on the playback speed, and as long as the characteristics of the tracking control circuit allow, so as not to impair signal detection within the vertical blanking period. Decide so that it is close to the vertical blanking period. The output of the timer counter 2 and the information of the timing setting circuit 7.8 are compared by the timer window comparator 3 to control the kick pulse generation trigger generation circuit 4t. According to the kick pulse generation command signal b' from the timer window comparator 3,
A kick pulse generation trigger signal C' is generated from the kick pulse generation trigger generation circuit 4 at the minimum cycle at which the reproducing scanner 10 can reliably change tracks, and is applied to the kick pulse generation circuit 9 through the OR gate 5. ' By the trigger signal d' that passed through the ORAGENIT 5.

A kick pulse e' is generated from the kick pulse generating circuit 9, and the scanning track of the reproduction scanner 10 is changed.

Achieve quick mosi-synchronization playback. here.

Although the number of kick pulses is managed in 9 hours by the timing setting circuit 7.8, the purpose can be similarly achieved by controlling the number of kick pulses by directly counting the kick pulses.

15 is a turntable on which the information recording medium 14 is placed, and 16 is a motor for rotating the turntable 15. FIG. 3 shows a specific configuration of the kick pulse generation instruction circuit A surrounded by a broken line in FIG. 1, and FIGS. 4 and 5 show time charts for explaining the operation of the portion shown in FIG. 3.

Vertical synchronization signal a' separated from Eirin signal (or game)
In addition to the kick pulse generation circuit 9 through 5t-, a kick pulse e' is generated within the vertical blanking period, and at the same time,
Clear the counter 22. The counter 22 is based on the trailing edge of the vertical synchronizing signal a'.

At the clock f' of the oscillator 21, the clock starts.

Here, it is also possible to use a horizontal synchronizing signal instead of the clock f' of the oscillator 21.

The ROM 24 (timing setting circuit 7) stores in advance the time based on the trailing edge of the vertical synchronizing signal a' at which kick pulse generation starts according to the playback speed specified from the keyboard 30 (playback speed instruction circuit 6). ing. The kick pulse generation time is the time to the leading edge of the vertical synchronization signal.

lX Kick pulse number tens t2 (t is the period of kick pulse generation determined to ensure that the track change of the reproducing scanner 10 is performed. t2Fi is the period when the temporary tracking disturbance due to the kick pulse generation is determined) (This is a time that does not affect signal detection within the vertical blanking period.) The value of the start time and the value of the counter 22 are compared by a magnitude comparator 23, and when the value of the counter 22 exceeds the start time, the output g' of the magnitude comparator 23 is
becomes High K, and the output b' of the AND gate 27 becomes H.
Make it igh. As a result, the counter 29 creates the timing for generating the trigger signal C' that instructs the generation of the kick pulse.
The clearing of is canceled, the clock signal i' of the oscillator 28 causes the sicant to rise, and the kick pulse generation trigger signal c' is generated at the first period t. The trigger signal C' is applied to a kick pulse generating circuit 9, which generates a kick pulse e'f outside the vertical blanking period.

The ROM 26 is stored in advance according to the specified speed. The time with reference to the trailing edge of the vertical synchronizing signal a' at the end of kick pulse generation is recorded. The kick pulse generation end time is set at t3 before the vertical synchronizing signal a' (t3 takes an intermediate value between t and t2). The value of the end time and the value of the counter 22 are compared by a magnitude comparator 25, and when the value of the counter 22 exceeds the end time, the output h' of the magnitude comparator 25 is
becomes Low, and the output b' of the AND gate 27 becomes Low.
become. As a result, the counter 29 is cleared, the generation of the trigger signal C' is stopped, and finally the number of kick pulses e' necessary for the specified playback speed is generated during the vertical blanking period and the vertical blanking period. Occurs as close as possible.

In this way, the video disc playback device of this embodiment is
The generation position of the kick pulse outside the vertical blanking period, which is generated to perform quick morsilon regeneration, can be controlled by time management according to the number of pulses, thereby making the 4 kick pulse positions as narrow as possible. To reproduce an easy-to-read receiver screen that can be brought to the top or bottom of the receiver screen and where the noise caused by the kick pulse is not noticeable during quick morsilon playback when the kick pulse needs to be output even outside the vertical blanking period. I can do it.

The present invention can also be realized by using a microcombiner processor, and if it is incorporated as part of the software of a microcombiner controller for a system controller of a video disc playback device, it will be effective in terms of cost.

As described above, the video disc playback apparatus of the present invention has the advantage that the quick morsilon playback speed can be increased without substantially deteriorating the quality of the receiver screen.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a video disc playback device according to an embodiment of the present invention, FIG. 2 is a waveform diagram of each part thereof, FIG. 3 is a specific block diagram of the main parts of the device shown in FIG. The figure is a waveform diagram of each part, #! FIG. 5 is a time-related expanded waveform diagram of the kick pulse generation command signal b', the clock signal 1', and the kick pulse generation trigger signal C' shown in FIG. 2... Timer counter, 3... Timer window comparator, 4... Trigger generation circuit for kick pulse generation, 6... Playback speed instruction circuit, 7.8... Timing setting circuit, 9... Kick Pulse generation circuit, 10... Reproduction scanner, 11... Tracking control signal detection circuit. 12... Tracking control circuit, 13... Demodulation circuit.

Claims (2)

[Claims] (1) A video disc playback device that plays back Eirin information from a disc-shaped information recording medium having a spiral information track, the playback scanner having an actuator that drives an optical pickup to scan the information track; A feeding circuit that sends the reproducing scanner in the radial direction of the information recording medium as the scanning track of the reproducing scanner changes, and controlling the reproducing scanner so that the reproducing scanner follows the track to be scanned. a tracking control circuit that controls the difference in radial position on the information recording medium between the track to be scanned and the reproduction scanner when changing the track to be scanned by the reproduction scanner during quick motion reproduction; a kick pulse generating circuit that causes the reproduction scanner to be sent by one track in the radial direction of the information recording medium for each kick pulse so as to be within a range that can be tracked by the circuit; and an image recorded on the information recording medium. a reproduction speed instruction circuit that instructs the reproduction speed of information and also provides reproduction scanner feed speed information to the feeding circuit; Detect the position of the scanner on the video signal. a kick pulse generation instruction circuit that instructs the kick pulse generation circuit to generate a kick pulse at a timing corresponding to the playback speed instructed by the playback speed instruction circuit during quick motion playback; The kink pulse generation circuit generates a sequence of kick pulses of the number required to change the reproduction speed of the track to be scanned by the reproduction scanner at a position closest to the vertical blanking period without impairing signal detection within the vertical blanking period. A video disc playback device designed to generate (2) The kick pulse generation instruction circuit includes a timer counter that detects the position of the reproduced scanner on the video signal based on a periodic signal in the reproduced vertical synchronization signal or similar video signal; a kick pulse generation trigger generation circuit that continuously generates a kick pulse generation trigger signal at a period corresponding to a minimum time during which the reproduction scanner can reliably change tracks, and supplies the kick pulse generation trigger signal to the kick pulse generation circuit; The period required for the kick pulse generation trigger circuit to generate a kick pulse generation trigger signal train to generate the kick pulse train of the number required to change the track according to the playback speed based on the instruction from the speed instruction circuit is defined vertically. A timing setting circuit sets the timing at a position closest to the vertical blanking period without impairing signal detection within the blanking period, and the kick occurs when the output of the timer counter and the output of the timing setting circuit match. A video disk reproducing apparatus according to claim 1, further comprising a timer window comparator for operating a pulse generating trigger generating circuit.