JPS61142567A - Disk turning device - Google Patents

Abstract

PURPOSE:To switch the operation of a disk turning device smoothly to control based upon an original error detecting signal when focus lock is executed again by controlling the objective number of revolution of the disk to the one obtained immediately before the generation of defocusing when the defocusing is generated during reproducing. CONSTITUTION:A pulse generating circuit 8 generates a sample holding (S/H) pulse and a sample holding (S/H) circuit 7 holds the output of an F/V converter on the basis of the S/H pulse. When a focus servo is unlocked, the generation of the S/H pulse is stopped in accordance with the level change of a focus locking signal. Since the unlocking of the focus servo due to a flaw on the disk surface or the adhesion of dust is executed for an extremely short period, the control of the number of revolution during the period can be attained by using the value obtained immediately before the unlocking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a technology for controlling CLV (Constant Level Viewing) of a rotating part MJ device of a disc in a video disc player.

[Background of the invention]

During the playback operation of the video dice player, if there is dirt or debris on the disc, which is the recording medium, the focus will be off and the information recorded on the disc will not be able to fit properly. Sometimes. In this case, if the control buttons of the rotary parts whg and t of the disc are used to control the information continued from the disc, the control of the rotary drive device will become improper.

When playing a CLV disc, it is necessary to change the rotational speed of the disc when playing back the inner and outer parts of the disc.
The signal is regenerated and used. However, in order to cover the gaps during disc playback, conventional video disc players have a configuration as shown in, for example, Japanese Patent Laid-Open No. 101161/1983. Loquat 2 for disc playback
Generate an approximate radial position signal using a potentiometer cooperating with the movement of the means, as a signal corresponding to the disk radial position dK of the means, and combine this radial position signal with the signal n reproduced from the disk. control signal? :tC is a rotating disc! t is controlled. In the event of a loss of control signal from the disk, the approximate radial position signal generated by the potentiometer is used to prevent the rotary drive from shifting too much.

@2 shows the pros and cons of this conventional control area. @1
58 supplies a pilot signal included in the video signal reproduced from the disc. 138 is a crystal oscillator that generates a reference signal. 136 converts the pyro signal to the crystal light f! This is a comparator circuit that compares the output of the output device 138 with the output of the device 138 to generate a fine speed control signal. Reference numeral 130 is a potentiometer that generates a rough speed control signal indicating the position of the via 21,1 in the disk radial direction. Reference numeral 154 is a motor control circuit that controls the motor speed by 'rN. 150 is a disk drive motor Ic coupled to 3! Flow tachometer - In such conventional devices, a potentiometer is used to mechanically detect the position of the via 21,1 means in the disk radial direction, so these mechanical parts have a high level of f!
I structure accuracy is required, so the parts themselves are the price,
The disadvantages are that it requires v4y and is not reliable against changes over time.

[Purpose of the invention]

The purpose of the present invention is to
To provide a disk @rotation drive 'Him device which can normally control a disk rotation drive device using a WJII even if a focus tip is dislodged.

[Summary of the invention]

In the present invention, when the focus chip is unlocked during the playback operation of the disc player, the control signal input to the disc motor drive device is inputted from the playback signal obtained from the disc to the λ The output is compared with the value immediately before the lock state of the output is released, and the rotation speed of the motor is controlled using the output of 9J.

[Embodiments of the invention]

The present invention will be explained below using examples. No.! ! This is the first example of the disk rotation excitation control device by FJAK. 1 is an error detector. Pi 2
It is necessary to drive the disk motor rotation from the information on the disk detected by the 111 means (1 not shown). ! A control signal is generated in this error detector 1. When the focus control is in the locked state, the motor rotation drive gicrIt is controlled only by the output signal of the error detector 1. Error detector lf! The output No. 1 is a signal similar to the output No. 1B of the comparison circuit 136 in the conventional example shown in FIG. 2 is a phase complement f1 circuit, and 3 is a motor drive circuit.

11 is a switch driven by focus lock No. 100.
When the focus tip is in the locked state, the state is indicated by a broken line, and when the focus tip is in the off state, the state is indicated by a solid line. 41) (If the focus tip has one 4-division detection element, for example, a 4D sum f signal or a signal obtained by inverting the phase of this signal can be used as the focus tip signal.

Reference numeral 12 denotes an input terminal to which a focus focus signal λ1 is applied.

4 is an F/V converter that converts the output signal of the F'' Q bar connected to the disk drive motor 14 into F/VR to generate a control signal. 7 is an F/VR converter. 4
The output signal of the 878 circuit is called chimple hold (hereinafter referred to as S/)1. Reference numeral 8 denotes a pulse generation circuit that generates a pulse for S/)l. A focus lock signal is introduced into the pulse generation circuit 8, and the focus lock signal is input to the pulse generating circuit 8.
When the condition is removed [8/H pulse derivation is stopped.

In this case, the 87H circuit 7 holds the value of the immediately previous output signal of the F/V converter 4.

A detailed explanation will be given below using the signal waveform diagrams shown in Figures 4 and 5. In Fig. 4, the horizontal axis shows the elapsed time (minutes) from the start of the disc player's playback operation, and the vertical axis shows the output of the KF/V converter (Fig. 4 (a)) and the focus lock signal (4th axis (b)). )).In this example, the focus lock signal is at the low level when the focus tip lock is off, and the focus signal is at the low level when the tip lock is off.

FIG. 4(a) shows the change in the F/V converter output as the rotational speed of the disk drive motor changes over time during the reproducing operation of the CLV Guisk.

The rotational speed of a CLV disk is generally 180 Or pm at the innermost circumference during reproducing, and 6QQ rpm at the outermost circumference.

In the example shown in the fourth example, it is assumed that the shifter focus is removed due to a scratch on the disk or the like around 20 minutes after the start of regeneration. The 5th row shows an enlarged view of the signal figure shown in the 4th row around 20 minutes.

As shown in FIG. 1, the present invention generates an S/H pulse in a pulse generating circuit 8, and uses this pulse to convert the output of the F/V converter 4 to the S/H circuit 7. to hold the temple. If the Focus Chibo's mouth or girder comes off, please change the level of the Focus Roy/M f)
Generation of S/H pulses is stopped. S/H circuit 7 is the mouth;
The value of the output signal of the F/V converter 4 just before the gate is disconnected is compared with the output of the F/VR converter 4, and the motor rotation speed is controlled by the control signal generated. It is done. It takes an extremely short time for the focus control to be unlocked due to scratches or dust on the disc surface, so the rotation speed control during this time can be achieved by using the value just before the lock is released.

This can be easily understood by looking at the change in the output of the F/V converter 4 shown in FIG. 4(a).

The third example shows the professional ring according to the second embodiment of the present invention. In the second embodiment, a target voltage generator 9 provides an initial value at the time of start of disk playback and a speed comparison a.
5 reference signal input to the target voltage generator 9 or 87El.
A second switch 13 for switching to the U path 7 was newly provided.

The second switch 13 is driven by a lead-in signal.

The lead-in signal is at the first level during the period from the start of the playback operation of the video disc player until the driven disc reaches a predetermined speed (1800 rpm in the previous example), and the lead-in signal is at the first level during the period from when the video disc player starts playing. This signal is at the second level while being driven at the same rotation speed.

During lead-in, increase the disc rotation speed to 180 from a static state.
Since the speed is increased to 0 rpm, if the focus tip comes off at this time, it will be in an unfavorable state. Therefore, at the time of lead-in, the disc rotation is set to the initial value of 180.
Since the voltage is 0 rpmK, the voltage derived by the target voltage generation circuit 9 may be set to a constant voltage corresponding to the initial value.

When the rotational speed of the disk reaches the first JG [Ktl], the level of the 9-doin signal changes, so the second switch 13
The reference input of the speed comparator 5 is S/ from the target voltage generation circuit 9.
Switched to H circuit 7.

The following operations are similar to those in the first embodiment.

〔Effect of the invention〕

According to the present invention, when an out-of-focus occurs during playback of a video disc player, the target rotational speed of the disc is controlled to the number of rotations immediately before the out-of-focus occurs, so that when the focus is lost again, the original rotation speed is controlled. It is possible to smoothly switch to control using the error detection signal. Also, like the target voltage generation means using a potentiometer in a conventional video disc player, since the position of the disc is mechanically detected, the l! Adoption of the present invention also solves the disadvantages of requiring extremely high mechanical precision and increasing costs. Furthermore, since the configuration of the present invention requires fewer mechanical parts, this configuration can be implemented as an IC.

[Brief explanation of drawings]

FIG. 1 shows a first embodiment of the present invention. Figure 2 is a conventional diagram, Figure S is a diagram of a second embodiment according to the present invention, and Figure 4 IXs is a signal diagram explaining the operation of the embodiment. It is. 1.-tA difference/fl unit, 2.-phase compensation circuit, 3.
・・Motor drive circuit, 4・-F/V converter, 5・・
・Speed comparator, 7... S/H circuit, 8... Pulse generation circuit, 11... Switch, P, 12... Focus lock signal input terminal, 13... Switch 2, 14・
...Motor, 15...FG.萬1 Fig. 22 Fig. night H+ button butt dent

Claims (1)

[Claims] 1. The output of a switch which has two inputs, the comparator output of the reference signal and the reproduced signal from the disk, and the pre-hold output of the rotational speed voltage obtained from the frequency generator, is used as the control voltage of the disk motor, and the switching of the switch is A disk rotation device characterized in that it is controlled by a disk read instruction signal.