JPS58156276A - Pickup cartridge shifting device of video disk player - Google Patents

Abstract

PURPOSE:To eliminate the disorder of a reproduced picture which is due to an external impact, by shifting a pickup cartridge only when a vertical synchronizing signal is detected by the pickup cartridge. CONSTITUTION:A stylus 6 detects a video signal. A vertical synchronizing signal separating circuit 15 separates a vertical synchronizing signal from the reproduced video signal and delivers it to an AND circuit 16. At the same time, an angle sensor 13 detects the inclination of the arm of a pickup cartridge. When the inclination of the arm is larger than a fixed level, the sensor 13 delivers the output of detection to the circuit 16. The circuit 16 delivers a signal only when both a vertical synchronizing signal output and the detection output of the sensor 13 are supplied at one time. An amplifier 17 amplifies the signal given from the circuit 16 and feeds it to a servo motor 18. The motor 18 is driven by an amplifying signal and shifts the pickup cartridge.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video disc player, and more particularly to a pickup cartridge moving device for a video disc player using a pickup cartridge detection method.

Video discs are WAI! similar to vinyl records! Screened in
A variety of systems are currently being developed for systems that reproduce audio and sound on television receivers. One of these methods is to coat the surface of the conductor that forms the disk with an extremely thin insulator, and record signals as extremely fine irregularities on the insulator without creating grooves. There is a method that detects and reproduces changes in

FIG. 1 is a schematic top view showing an example of a part of a disc and a pickup cartridge of a video disc player according to the above-described method, and the internal structure of the pickup cartridge is shown.

Further, FIG. 2 is a front view of the schematic portion shown in FIG. 1.

In this structure, a disk 1 on which a video signal is recorded as tracks without grooves on both the front and back surfaces is placed so that a hole 1a provided in the center thereof is aligned with a projection at the center of a turntable (not shown). The pickup cartridge 2 includes a needle 6 supported by a stylus holder provided at the tip of an arm 8 constituting the pickup cartridge 2.
The pickup cartridge moving device 111 is moved so that the longitudinal direction of the arm 8 coincides with the direction of the track 1b at the point where the arm 8 contacts the track 1b on the disk 1.
supported and placed. The pickup cartridge 2 has coil supports 4a, 4b, 4 inside a base frame 3 fixed to the pickup cartridge moving device 11.
c, 4d and both suspensions 9a formed of a rubber-like flexible material.

Coils 5a, 5b, 5c, and 5d are provided at the tip of each coil support, and a tapered arm 8 is provided between both suspensions 9a and 9b, and an insulating material is provided at the tip of the arm 8. A stylus holder formed by a stylus holder is provided to support the needle 6. A small permanent magnet 10 is provided inside the arm 8.

Also, inside the foundation frame 3, an angle sensor 13 is installed on the support part 12.
provided through.

In operation, as the turntable (not shown) rotates, the disc 1 placed thereon also rotates about the hole 1a. Pickup cartridge 2 is on track 1
The video signal recorded as the unevenness of the insulator in b is
Changes in capacitance are electrically detected and reproduced by the needle 6 in order from the outer track on the straight line indicated by A-A''.

As mentioned above, since the track 1b does not have a groove, a special positional control signal is recorded on the track in advance to control the position of the needle 6 so as to follow the track.

The tracks draw concentric circles around the hole 1a, and the needle 6 moves to an inner track each time it goes around one track.

Movement of the needle 6 along the straight line A-A- is achieved by movement of the arm 8 and movement of the entire pickup cartridge 2. That is, each coil 5a, 5b is controlled based on one control signal recorded on the track.

A current flows through 5c and 5d, creating a clockwise rotational moment in the permanent magnet 10, causing the arm 8 to tilt inward and the needle 6 to move to the inner track. Through repeated intuition, if the longitudinal direction of the arm 8 has an inclination angle of more than a certain degree with respect to the direction of the track 1b at the point where the needle 6 contacts the disk 1, the angle sensor 13 detects this. It is detected, and the big amplifier cartridge moving device 11 is operated to move the entire pickup cartridge 2 in the Y direction. Since the arm 8 also moves while the entire pickup cartridge 2 is being moved, the movement of the entire pickup cartridge 2 is much faster than the movement of the arm 8. As a result, the pickup cartridge 2
The longitudinal direction of the arm 8 is equal to the direction of the track 1b,
Return to the original state. By repeating the above operations, the position of the needle 6 moves along the straight line A-A''.

FIG. 3 shows an example of the disc 1. As shown in FIG. In the figure, a video signal is recorded in an intermediate portion 1C. As for the video signal, a vertical synchronizing signal is recorded in a small angle portion 2θ that divides the disc 1 into four, and a video signal is recorded in the other portions.

By the way, the conventional pick amplifier cartridge moving device 11 used in the above-mentioned video disc player always operates in response to the output of the angle sensor 13. Therefore, the entire movement of the pickup cartridge 2 is limited to the movement of the needle 6.
This is done regardless of whether the position is in the video signal portion or the vertical synchronization signal portion of the disc 1. The position of the needle 6 can be sufficiently controlled by the position control signal recorded in advance on the track, as described above, even while the entire pickup cartridge 2 is moving. However, if an external impact is applied to the video disc player while the entire pickup cartridge 2 is moving, the impact will cause fluctuations in the needle 6 in addition to the fluctuations caused by the movement of the entire pickup cartridge 2, and the needle 6 will temporarily become unstable. Position control may become impossible. For this reason, the position of the needle 6 is slightly deviated from the track 1b, albeit for a short time. If such a situation occurs when the needle 6 is in the video signal section, the needle 6 will deviate from the track, causing
Noise occurs in the image on the receiver, making it unsightly.

Therefore, an object of the present invention is to provide a pick amplifier cartridge moving device that operates only when the pickup cartridge is not detecting a video signal.

In summary, the present invention separates a vertical synchronizing signal from a video signal detected and reproduced by a pickup cartridge, and configures a pickup cartridge moving device such that it is activated only when the separated output is present.

The above objects and other objects and effects of the present invention will become more apparent from the following detailed description with reference to the drawings.

FIG. 4 is a schematic block diagram showing a pickup cartridge moving device which is an embodiment of the present invention.

In the configuration, the video signal reproducing circuit 1 to which the needle 6 is connected
The output side of the vertical synchronization signal separation circuit 15 is connected to the input side of the vertical synchronization signal separation circuit 15, and the output side of the vertical synchronization signal separation circuit 15 is connected to one input side of the AND circuit 16. An angle sensor 13 is connected to the other input side of the AND circuit 16, and an output side of the AND circuit 16 is connected to a servo motor 18 via an amplifier 17.

In operation, the video signal detected by the needle 6 is reproduced by the video signal reproduction circuit 14. The vertical synchronization signal separation circuit 15 separates the vertical synchronization signal from the reproduced video signal and outputs it to the AND circuit 16. On the other hand, if the angle sensor 13 detects that the inclination of the arm 8 of the pickup cartridge 2 is equal to or greater than a certain value, it outputs a detection output to the AND circuit 16. The AND circuit 16 outputs a signal only when the vertical synchronization signal output and the detection output of the angle sensor 13 are input simultaneously. This signal is amplified by the amplifier 117 and then sent to the servo motor 18, and the servo motor 18 is driven by this amplified signal to move the pickup cartridge 2.

As a result, the entire pickup cartridge 2 is moved only when the needle 6 is in the vertical synchronization signal section.

FIG. 5 is a schematic block diagram showing a pick-up 9-up cartridge moving device according to another embodiment of the present invention.

The difference in configuration from the embodiment shown in FIG. 4 is that a delay circuit 19 and a time width setting circuit 20 are provided between the AND circuit 16 and the amplifier 17. The input side of the delay circuit 19 is connected to the output side of the AND circuit 16, and the output side of the delay circuit 19 is connected to the input side of the time width setting circuit. The output side of the time width setting circuit 20 is an amplifier 117
connected to the input side of the

The difference in operation from the embodiment shown in FIG. 4 is that the output signal of the AND circuit is delayed for a certain period of time and set to a certain time width before being applied to the servo motor 18. That is, the output signal of the AND circuit 16 is delayed by the delay circuit 19 for a certain period of time. This fixed time is
One video signal section (third
In the figure, the section indicated by 1d) is set to be slightly shorter than the time required for the needle to pass through the needle 6. By doing this, the output signal of the AND circuit 1116, which is generated when the hand 6 is in a certain synchronization signal section, is sent to the servo motor 18 just before the hand 6 enters the next synchronization signal section. That is, the servo motor 18 starts operating immediately before the hand 6 enters the synchronizing signal section, and stops operating immediately before the hand 6 exits the synchronizing signal section. In practice, there is some time delay in moving and stopping the entire pickup cartridge 2 by the servo motor 18, so by using the above-mentioned delay circuit 19, the movement of the pickup cartridge 2 can be made completely compatible with the synchronization signal section. It becomes possible to do this.

The delay circuit 19 can be easily realized by applying the horizontal synchronizing signal to a seven-lip flop circuit or the like.

Next, the AND circuit 1 is delayed for a fixed time by the delay circuit 19.
The output signal No. 6 is set to have a constant time width by a time width setting circuit 20. By doing this, the pickup cartridge 2 is activated only during a part of the time when the hand 6 is in the synchronization signal section.
It is possible to move the whole thing.

As described above, according to the present invention, since the pickup cartridge is moved only when the pickup cartridge detects the vertical synchronization signal, it is possible to obtain the effect that the reproduced image II is not disturbed by external shocks.

[Brief explanation of drawings]

FIG. 1 is a top view showing an example of a part of a disc and a pickup cartridge of a video disc player using a pink-up cartridge detection method, and the internal structure of the pickup cartridge is shown. FIG. 2 is a front view of the schematic portion shown in FIG. 1. Figure 3 is similar to Figure 1 and Figure 26! ! FIG. 4 is a schematic block diagram showing a pickup cartridge moving device, which is an embodiment of the present invention. FIG. 1 is a schematic block diagram showing a pickup cartridge moving device according to an embodiment. In the figure, 1 is a disk, 1b is a track of the disk, 1C is a video signal recording portion of the disk, 2θ is a periodic signal recording portion of the disk, 2 is a pickup cartridge, 6 is a needle of the pickup cartridge, 8 is an arm of the pickup cartridge, 11 is a pickup cartridge moving device, 13 is an angle sensor, 14 is a video signal reproducing circuit, 15 is a vertical synchronization signal valve # circuit, 16 is a The AND circuit, 17 is an amplifier, 18 is a servo motor, 19 is a delay circuit, and 20 is a time width setting circuit.Representative Ge Shu Xin - (1 other person) 13- 1st eye A A' Figure 2 1 31 Procedural amendment (volunteer to the Commissioner of the Patent Office 1, Indication of the case, Patent Application No. 1989-89903 2,
Title of the invention 3. Person making the amendment 5. Detailed description of the invention in the specification subject to the amendment Correct to "te". that's all

Claims (3)

[Claims] (1) A video disc player that uses a pickup cartridge to detect and play back a video signal consisting of a video signal and a vertical synchronization signal, which is recorded on a video disc that has at least a video signal recording part and a vertical synchronization signal recording part. an apparatus for moving the pickup cartridge, which is used for moving the pickup cartridge, comprising: means for separating the vertical synchronization signal from the video signal; means for detecting whether movement of the pickup cartridge is necessary; A pickup cartridge moving device for a video disc player, comprising means for generating a pickup cartridge movement signal for moving the pickup cartridge in response to an output and an output of the detection means. (2) The video disc is of a non-grooved capacitive type, and the pickup cartridge has a rotatable arm and a needle provided at the tip of the arm to detect the video signal, and the pickup cartridge has a rotatable arm and a needle for detecting the video signal. 2. The pickup cartridge moving device for a video disc player according to claim 1, wherein the means is an angle sensor that detects the inclination of the arm. (3) The means for generating the pickup cartridge movement signal includes means for setting the pickup cartridge movement signal to a predetermined constant time width, and means for delaying the pickup cartridge movement signal by a predetermined constant time width. A pickup cartridge moving device for a video disc player according to claim 1 or 2, which is operable to move a pickup cartridge of a video disc player.