JPS6354081A - Stroboscopic motion reproducing system - Google Patents

Abstract

PURPOSE:To indicate an extraction interval of reproduced scene clearly by selecting video information from the information read from a recording disk, writing it sequentially in a video memory and applying notice changing synchronously with the write. CONSTITUTION:In giving a command of reproducing stroboscopic motion, a processor in a system controller 40 writes a rewrite period data inputted at the same time as the command to a RAM in the controller 40. when the processor discriminates it that the contents of the vertical synchronizing counter is coincident with the rewrite period data, the processor gives a write enable signal until the vertical synchronizing signal is outputted again from the separation circuit 26 to write a video data by one field read from the disk 2 to the RAM 33. When the processor discriminates it that a toggle flag is set, the processor inserts a character or the like representing the rewrite period into the reproduced picture. Then the notice changing synchronously with the movement of the picture reproduced during the stroboscopic motion reproduction is given to indicate the interval of scene extraction clearly.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a strobe motion playback system, and particularly to a storage disc that plays strobe motion video information obtained from a recording disc such as a video disc.
CA~' (constant angular velocity) disk and CLV (constant linear velocity)
There is a disk.

In the case of a CAV disc, a certain amount of information, for example, video information for one frame, is recorded on one round of tracks formed at any position in the radial direction. The portions in which information corresponding to the vertical synchronization signal is recorded exist so as to be arranged on a straight line extending in the radial direction. Therefore, in the CAV disc, there is no disturbance in the period of the synchronization signal of the reproduced video signal immediately after the jump operation, and special reproduction such as still image reproduction can be performed satisfactorily.

However, in the case of a CLV disc, the amount of information recorded on one track varies depending on the position in the radial direction. For example, the innermost track contains video information for one frame, and the outermost track For example, video information for three frames is recorded on the track. For this reason, in the CLV disk, a disturbance occurs in the period of the synchronization signal of the video signal obtained immediately after the jump operation. Therefore, a video memory with a storage capacity capable of storing one frame or one field of video signals is provided, the video signal is converted into a digital signal by a clock synchronized with the reproduced video signal, and this is written to a predetermined location in the video memory. Information reproducing apparatuses have been proposed in which information is read using an external stable clock.

In such an information reproducing apparatus, strobe motion reproduction, that is, scene sampling reproduction is possible by extracting a portion corresponding to one frame or one field at a desired cycle from video information obtained from a recording disk and sequentially writing it into a video memory. be. However, in this strobe motion playback, the interval between scene sampling is not necessarily so clear that it can be easily determined visually.

SUMMARY OF THE INVENTION An object of the present invention is to provide a strobe motion playback method that can specify the scene sampling interval for strobe motion playback in an information playback device having a video memory.

The strobe motion playback method according to the present invention starts reading recorded information on a recording disk in response to a strobe motion command, and selects at least one field of video information at a specified cycle from the information read from the recording disk. The information stored in the video memory is repeatedly read out and output as reproduced video information, and notifications that change in synchronization with the writing of information to the video memory are made.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, recorded information on a disk 2 that is rotationally driven by a spindle motor 1 is read by an optical pickup 3. As shown in FIG. The pickup 3 includes a laser diode, an objective lens, a focus actuator, a tracking actuator, a photodetector, and the like. The output of the pickup 3 is supplied to an RF amplifier 4, and at the same time, is supplied to a focus servo circuit (not shown) and a tracking servo circuit (not shown).

The focus actuator and tracking actuator in the pickup 3 are driven by these focus servo circuits and tracking servo circuits, and the laser light emitted from the laser diode in the pickup 3 is converged on the recording surface of the disk 2 to form a light spot for information detection. The position of the light spot in the radial direction of the disc 2 is controlled so that the light spot is located on a track formed on the recording surface of the disc 2.

Further, the coil current supplied to the coil for driving the tracking actuator in the pickup 3 is supplied to the current detection circuit 5. A current detection signal corresponding to the coil current is output from the current detection circuit 5 and supplied to the slider servo circuit 6. In the slider servo circuit 6, the current detection signal is amplified and compensated for. The output of the slider servo circuit 6 passes through a motor drive circuit 7 and becomes a drive signal for the slider motor 8. This slider motor 8 drives a slider 9 on which the pickup 3 is mounted and is movable in the disk radial direction, and the tracking actuator in the pickup 3 is controlled so as to be located at the midpoint of its movable range.

On the other hand, the RF multiplied signal output from the RF amplifier 4, BPF
(Bandpass filter) 10 and 11, where the audio FM signals of both left and right channels are extracted and separated. These two channels of audio FM signals are supplied to FM demodulators 12 and 13, respectively, and the two channels of audio FM signals are reproduced. The audio signals of these two channels are supplied to de-emphasis circuits 14 and 15, and the components emphasized during recording are returned to their original levels. These de-emphasis circuits 14
and 15 are supplied to audio output terminals 16 and 17.

In addition, the RF multiplied signal output from the RF amplifier 4, BPF
18, and the video FM signal is extracted and separated. After the amplitude of this video FM signal is limited by a limiter 19, it is supplied to an FM demodulator 20 to reproduce the video signal. This video signal is supplied via an LPF (low pass filter) 21 to one input terminal of a changeover switch 22 for dropout compensation. Changeover switch 22
A video signal delayed by an IH (horizontal synchronization period) delay line 23 is supplied to the other input terminal of. A dropout detection signal output from a dropout detection circuit 50 is supplied to this changeover switch 22 as a control signal. The dropout detection circuit 50 has an H
An RF multiplied signal high frequency component extracted and separated by a PF (bypass filter) 51 is supplied. The dropout detection circuit 50 is configured to detect a dropout using, for example, a zero-crossing point of the high-frequency component of the RF multiplied signal and generate a dropout detection signal. This dropout detection signal controls the signal switching of the selector switch 22, and when a dropout occurs, the pre-IH video signal output from the IH delay line 23 is selectively output from the selector switch 22 to compensate for the dropout. Ru.

The video signal output from the changeover switch 22 is a CCD
(Charge Coupled Device
)24. A clock output from a VCO (voltage controlled oscillator) 25 is supplied to the CCD 24 . In the CCD 24, the video signal is delayed by a time corresponding to the clock frequency. The video signal output from this CCD 24 is supplied to a separation circuit 26. Separation circuit 26 is configured to separate control data, such as horizontal and vertical synchronization signals and Phillips codes, from the video signal. The horizontal synchronization signal output from this separation circuit 26 is supplied to a spindle servo circuit 27. In the spindle servo circuit 27, the horizontal synchronization signal is phase-compared with a reference signal of a predetermined frequency from the reference signal generation circuit 28, and a spindle error signal is generated according to the phase difference between the two signals. This spindle error signal is supplied to the motor drive circuit 29 to control the rotational speed of the spindle motor 1. At the same time, a control signal corresponding to the phase difference between the horizontal synchronization signal and the reference signal is generated.
It is supplied to the control input terminal of CO25. Then, V
The oscillation frequency of the CO 25 corresponds to the phase difference between the horizontal synchronization signal and the reference signal, and the signal delay time of the CCD 24 changes according to the phase difference, thereby eliminating the time axis error.

The video signal whose time axis error has been removed by the CCD 24 is supplied to one input terminal of a changeover switch 30 and at the same time is supplied to an A/D (analog/digital) converter 32 via an LPF 31 . A/D converter 32
, the video signal is sampled at a predetermined period, and the obtained sample values are sequentially converted into digital data.

The output data of this A/D converter 32 is supplied to a RAM 33 as a video memory. Address control and mode control of the RAM 33 are performed by a memory control circuit 34. The memory control circuit 34 is arranged such that the data written in each address of the RAM 33 is sequentially read out using a clock from the reference signal generation circuit 28, and the contents of each address of the RAM 33 are rewritten in response to a write enable signal. It is configured to control the R.A.M.
The data read from 33 is supplied to D/A converter 35 and converted into an analog signal. The output of this D/A converter 35 is supplied to a sync insert circuit 37 via an LPF 36, a synchronizing signal is added thereto, and a video signal is reproduced. The video signal output from the sink insert circuit 37 is supplied to the other input terminal of the changeover switch 30. The changeover switch 30 is supplied with a control signal for changeover control from the system controller 40 . One of the video signal from the changeover switch 30 via the RAM 33 and the video signal directly supplied to the changeover switch 30 from the CCD 24 is selectively supplied to the character insertion circuit 41. The character insertion circuit 41 is configured to combine the video signal corresponding to the character indicated by the data sent from the system controller 40 with the video signal from the changeover switch 30. A video signal output from this character insertion circuit 41 is supplied to a video output terminal 42.

The system controller 40 includes a processor, ROM, R
It is formed by a microcomputer such as AM. The system controller 40 receives a synchronization signal and control data from the separation circuit 26, data corresponding to the key operations of the operation keys 48, a loading detection signal from the loading machine (a loading detection signal from the core, a disk detection signal, etc.).The system controller 40 In the processor, the processor processes the input signals according to a program stored in advance in the ROM, and processes the input signals in accordance with the program stored in the ROM in advance.
7, changeover switch 30, memory control circuit 34, character insertion circuit 41, drive circuit 43 for driving the laser diode,
It controls each section such as a track jump drive circuit 44 that drives a tracking actuator in response to a jump command, a motor drive circuit 46 that drives a motor 45 for the disk loading r-1, and a display circuit 47. Further, the power supply terminal of the system controller 40 is supplied with a power supply VcC via a diode D. A capacitor C is connected between the power terminal of the system controller 40 and ground. A backup circuit 49 is formed by the diode D and the capacitor C, and power is supplied to the system controller 40 even when the power is off.

In the above configuration, the operation of the processor in the system controller 40 will be explained with reference to the flowchart in FIG. 2.

When strobe motion playback is commanded by a key operation by the user during execution of the main routine, the processor moves to step S1 and stores the rewrite cycle data input at the same time as the command into the RAM in the system controller.
write to the specified location.

Next, the processor moves to step S2 and determines whether a vertical synchronization signal is output from the separation circuit 26. When it is determined in step S2 that the vertical synchronization signal is not output, the processor repeats the execution of step S2, and only when it is determined that the vertical synchronization signal is output, the processor moves to step S3 and the system Add 1 to the contents of the address used as the vertical synchronization counter in the RAM in the controller.

Next, the processor moves to step S4 and determines whether the value of the vertical synchronization counter matches the rewriting cycle data. If it is determined in step S4 that the value of the vertical synchronization counter does not match the rewriting cycle data, the processor repeats the processing from step S1 onwards. When it is determined in step S4 that the value of the vertical synchronization counter matches the rewriting cycle data, the processor moves to step S5 and resets the value of the vertical synchronization counter.

Next, the processor moves to step S6, sends out a write enable signal, and writes one field's worth of data into the RAM 33 until the vertical synchronization signal is outputted again from the separation circuit 26. Next, the processor moves to step S7 to check the RA in the system controller 40.
It is determined whether the toggle flag is set based on the toggle flag data stored in a predetermined location of M. If it is determined in step S7 that the toggle flag is not set, the processor moves to step S8 and erases the display indicating the rewriting cycle.

If it is determined in step S7 that the toggle flag is set, the processor proceeds to step S9 and inserts characters or the like indicating the rewriting cycle into the reproduced image to notify that the strobe motion is being reproduced.

The processor then moves to step SIO and inverts the toggle flag. The processor then performs step S
ll, and it is determined whether a command to cancel strobe motion reproduction has been issued.

If it is determined in step Sll that the release command has not been issued, the processor repeats the processing from step S1 onwards. If it is determined in step Sll that a release command has been issued, the processor resumes execution of the main routine.

As a result of the above operations, if the information of A frame to J frame is sequentially read from the disk as shown in FIG. 3(A), and the rewriting cycle is four times the period of one frame, As shown in (B), only the information of the A frame, E frame, and I frame is repeatedly reproduced four times each.

Furthermore, 1/4 is displayed on the images of the A and I frames as a number indicating the rewriting cycle, and this number appears and disappears in synchronization with the rewriting cycle to notify that strobe motion is being reproduced.

In the above embodiment, small images such as letters are inserted in the corners of the screen in the reproduced image to notify strobe motion reproduction, but other means such as lighting a light emitting element or emitting a sound may also be used. Alternatively, strobe motion playback may be announced by changing the tone or hue of the entire screen.

Effects of the Invention The strobe motion playback method according to the present invention starts reading recorded information on a recording disk in response to a strobe motion command, and reproduces at least one field of video at a specified period from the information read from the recording disk. Information is selected and sequentially written to the video memory, the information stored in the video memory is repeatedly read out and output as playback video information, and notifications that change in synchronization with the writing of information to the video memory are made, so that strobe motion is played back. An announcement that changes in synchronization with the movement of the reproduced image will be made, and the interval between scene sampling will be clearly indicated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an information reading device adopting the method according to the present invention, FIG. 2 is a flowchart showing the operation of the device in FIG. 1, and FIG. 3 is a block diagram showing the operation of the device in FIG. FIG. 3 is a diagram showing information outputted as playback information and information outputted as playback information.

Claims (1)

[Claims] A strobe motion playback method for an information playback device having a video memory for storing video information obtained from a recording disk, wherein reading of recorded information on the recording disk is started in response to a strobe motion command, and the reading of recorded information on the recording disk is started. At least one field worth of video information is selected at a specified cycle from the information read from the information and sequentially written into the video memory, the information stored in the video memory is repeatedly read out and output as reproduced video information, and A strobe motion playback method characterized by making announcements that change in synchronization with the writing of information.