JPS5828644B2 - video disk player stylus kenmasouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stylus polishing device for a video disc player, and each time the scanning body is transferred to the polishing disk side having a plurality of concentric polishing grooves, a pickup supported by the scanning body is removed. The stylus is cyclically pressed against different grooves of the abrasive grooves, thereby prolonging the life of the abrasive disk.

2. Description of the Related Art Record carriers, commonly known as video disks, are known, in which video signals or video signals with audio signals (video signals, etc.) are recorded in spiral grooves on a disc-shaped carrier made of soft synthetic resin (for example, polyvinyl chloride).

Further, the center of the video disc is fixed to a rotating shaft passing through a stationary table, and the rotating shaft is rotated at high speed, for example, 1800 revolutions per minute (NTSC system), so that the video disc is placed between the stationary table and the video disc. A pickup is mounted on a generated air flow and is stably rotated, and is supported by a scanning body that is driven in the radial direction of the video disk in deceleration synchronization with the rotating shaft, and the video disk that rotates stably and at high speed in this manner. A video disc player is also known in which a stylus is brought into pressure contact with the video disc to extract a video signal recorded on the video disc.

Although the stylus is made of a hard material such as diamond, it travels at relatively high speeds while pressing against the grooves of the video disc, so cutting chips from the video disc stick to the tip of the stylus. It has been confirmed that the needle tip wears out.

The reason why the stylus wears out like this is that the tip of the stylus, which is in pressure contact with the video disc, becomes carbonized and softens due to a significant temperature rise, making it more likely to wear out, and with repeated use, the internal structure of the stylus changes, causing so-called It is believed that stylus wear is caused by a combination of causes such as mechanical chipping and increased wear.

Therefore, in order to deal with such wear and keep the stylus in the best condition, it is necessary to polish the stylus for a certain period of time (about a few seconds) each time a video disc is played, and then to prepare for the next playback. A method of preparing for this is being considered.

That is, a method has been considered in which a stylus of a pickup supported by a scanning body is placed at a certain location above a rotationally controlled polishing disk having a plurality of concentric grooves, and the stylus is lowered onto the grooves to perform polishing. However, this method has the drawback that only certain grooves are used for polishing the stylus, and the service life of the polishing disk is not long.

The reason why multiple polishing grooves are provided on the polishing disk in this method is that even if there is an error in the movement accuracy of the scanning body, or the stylus of the pickup, which has compliance in the normal direction of the polishing grooves, remains constant. This is to allow the stylus to fit into any of the polishing grooves due to the compliance even if the stylus is not supported by the scanning body due to the positional relationship.

In order to eliminate the above-mentioned drawbacks, the present invention has been proposed by forcing the stylus of the pickup to be placed above a different groove of a plurality of abrasive grooves each time the stylus is brought to the side of the abrasive disk, and by cyclically moving the stylus into the abrasive groove. It is an object of the present invention to provide a stylus polishing device for a video disc player having a press-contact function.

An embodiment will be described below with reference to the drawings.

FIG. 1 shows a video disc player (
FIG. 2 shows a partially cutaway front view of the same player.

In each figure, 1 is a chassis, 2 is a stationary table fixed to this chassis, each is a jacket holder placed above this stationary table and fixed to the chassis by suitable fixing means (not shown), and the holder is It is provided with a lower plate 4 having a U-shaped cross section that supports a jacket (described later), an upper plate 5 covering it, and a translucent cover 6, and is used for attaching and detaching the jacket.

Reference numeral 7 indicates a jacket formed so that the video disc 8 can be inserted into and removed from the jacket.

This jacket is organically associated with each of the holders so that it is locked in the installed position once it is installed in the holder, and is unlocked when the video disc removed from the jacket is reinstalled. (not shown).

Reference numeral 9 denotes a guide plate used to guide the video disc that is transferred by rollers (not shown) from the jacket side to the stationary table side or in the opposite direction, and the inner surface of the guide plate is curved so that the video disc can easily slide into contact with the video disc. Allow to be formed and made as smooth as possible.

10 is a motor, 11 is a rotating shaft of the motor, 12 is a rotary table fixed to the shaft and whose flat part on which a video disc is placed protrudes from an opening 13 in the stationary table; 14 is a speed reduction mechanism (
(not shown) to transmit the driving force of the motor to the feed rope (described later).

Reference numeral 15 denotes a chuck that is controlled to move vertically in the drawing in connection with the transport of the video disc, and the chuck includes a protrusion 16 that engages with the center hole of the video disc (the chuck control mechanism is not shown).

This protrusion fits into the recessed hole 17 of the rotary table.

The video disc is then sandwiched between the rotary table and the chuck and integrated into the rotary table.

When the chuck 15 is lifted upward, the video disc on the rotary table can be transported along the stationary table by the rollers.

18 is connected to the guide rail 20.21 by the feed rope 19.
, 22, and basically includes a moving table 30 having a pickup holder 50 to which a pickup case 60 can be attached and removed, and a preamplifier case 40 attached to the moving table.

The scanning body 18 is reciprocated in the radial direction of the video disc via a feed rope 19 by controlling an operating knob (not shown).

Therefore, the operation of transporting the pickup from the position shown in the first figure (A position) to above the playback start position (B position) of the video disc, and from above the playback end position (C position) via B position to A position. The operation of reverting to is accomplished by said legitimate child.

In addition, the operation of lowering the pink-up onto the video disc from above position B is performed by pressing the play button (not shown), while the operation of lifting the pickup that has arrived at position C above it is automatically performed by detecting its arrival. This is achieved by pressing a button or a stop button (not shown), respectively.

Further, the pickup during play is transported at a constant speed by a feed rope 19 whose deceleration is synchronized with the motor 10.

Selection of the drive source for the feed rope, ie, the operating knob or the motor, can be accomplished by switching the clutch by pressing the play button.

23 is an angle 24 fixed to the chassis. 21 is a rail mounting frame that is automatically supported by a bent piece 23.
a comes into contact with the flange portion 25a provided in the stylus pressure regulator 25, and the amount of rotation of one side is regulated, and the amount of rotation of the other side is restricted by the amount of rotation of the other side.
The guide rail 22 contacts and is regulated by the arch-shaped elongated hole 26 provided in the guide rail 26.

The details of the swing control mechanism of the frame 23 are not shown because they are outside the scope of the present invention.

The kite rails 20, 21, 22 are inserted and supported between one wing piece 23b of the frame 23 and a rail mounting plate 27 attached to the middle of the frame.
is made to protrude to angle 24.

A pulley 28 for guiding the feed rope is supported on the rail mounting plate 27.

The guide rail 21 serves as one rotation fulcrum of the frame 23, and the other rotation fulcrum is a support shaft 29 that supports the frame 23 on the angle 24.

Next, the relationship between the guide rail and the scanning body will be briefly explained.

The guide rail 21 engages with the groove 30a on the bottom of the moving table,
On the other hand, the guide rail 22 engages with the bottom surface 30b at the rear of the moving table.

Furthermore, the guide rail 20 feeds its lower surface to the rope attachment 3.
It engages with a rolling contact roller 33 that is supported by a support shaft 32 that is rotatably supported by the rotor 1.

One end of the support shaft 32 is biased by the elastic body 34 to press the rolling roller into contact with the guide rail 20.

Thus, the movable table 30 is transferred along the guide rails 20, 21 and 22 without play.

The preamplifier case 40 attached to this moving table is equipped with the necessary circuits inside and is designed to disconnect the playback output signal from the pickup to the circuit in response to the operation of attaching and detaching the pickup case 60 to and from the pickup holder 50. However, the details are omitted.

Similarly, details of the configuration and operation of the pick amplifier holder 50 and the pickup case 60 that is attached to and detached from the pick amplifier holder 50 will also be omitted.

Reference numeral 36 denotes a moving table lock cam attached to the open end of a shaft 37 having one end fixed to the angle 24, and this cam is attached to the scanning body 1.
When 8 is brought to the right end, the follower is provided on the moving platform.
38.

Therefore, when the scanning body is brought to the right end in order to attach and detach the pickup case from the pickup holder, the scanning body comes into contact with the lock cam and the guide rail 22 that come into contact with the follower.
This is restricted by the angle 24 that comes into contact with the scanning body, and prevents the scanning body from wobbling during the above-mentioned attachment and detachment.

70 is a polishing disk, 71 is a motor that controls the rotation of the disk, 72 is a plunger that controls the vertical movement of the motor in the direction of the arrow shown in FIG. 2, and 73 is an angle for fixing the plunger to the chassis 1. .

In the illustrated embodiment, a motor 7 controls the rotation of the polishing disk.
1 is independent of the motor 10 that controls the rotation of the video disc, since generally in order to polish the stylus in a short time, it is desirable that the rotation speed of the polishing disc is sufficiently larger than that of the video disc, for example 10,000 rpm. However, the driving force of the motor 10 can also be utilized by providing a speed increasing mechanism.

The shape of the polishing disk will now be described with reference to the sectional view of FIG.

The polishing disk 70 includes a support base 70a and a polishing sheet 7.
0b, and the abrasive sheet has a plurality of abrasive grooves 70c formed by press-fitting diamond powder (not shown) into a plurality of concentric grooves (including spiral grooves that can be considered as substantially concentric circles). The stylus of the pickup, which is press-fitted into this groove, is polished by the diamond powder when the polishing disk rotates, and the shape of the tip of the pickup returns to its original shape.

At this time, wear and deformation inevitably occurs on the abrasive sheet side, and therefore, if the stylus is pressed against a specific abrasive groove of this abrasive sheet, the life of this sheet will not be long. be.

Next, - each time the polishing process is performed, a different groove of the above-mentioned polishing grooves is used.

The arrangement for making the stylus of the pick-up face each other will be explained in accordance with the main part assembly configuration diagram in FIG. 4, and its operation will be explained in accordance with the operational explanatory diagram in FIG. 5.

Because of this configuration, the rail mounting frame 23 has a long pin guide hole 81 in the longitudinal direction, and a support hole 82 for a retaining pin.
A support hole 83 for a bearing and screw holes 84 and 85 are formed respectively, and a control pin 87 that engages with the guide hole 81 and controls a slide plate 86, which will be described later, is provided in the movable table 30. Also provided is an abutment pin 88 that abuts against an eccentric cam, which will be described later.

The slide plate 86 has a long hole 86.a in the sliding direction, and the mounting screw 8 has a shaft portion 89a passing through the long hole.
9 into the screw hole 84, the frame 2
Attach to 3 so that it can slide freely.

Further, this slide plate 36 is moved in a certain direction (
(in the direction of the locking pin).

The eccentric cam 92 has a bearing 9 mounted in the support hole 83.
It is fixed by a screw 94 to the upper end of a shaft 93 that penetrates through the shaft 93, and is arranged so that its circumferential side 92a faces the abutting pin 88.

A small wheel 95 controlled by the claw piece 86b of the slide plate is fixed to the lower end of the shaft 93 with a screw 36.

Thus, the rotation of this small wheel is transmitted to the eccentric cam 92 through the shaft 93.

A stopper 97 prevents the small wheel from rotating backwards when the claw piece is removed from the small wheel, and is fixed to the screw hole 85 of the frame 23 with a screw 98.

In such a configuration, when the scanning body 18 is transferred from the video disk side to the polishing disk side, the control pin 87 provided on the moving table 30 abuts against the slide plate 86, causing the slide plate to resist the spring 91. and slide it to the right.

As a result, the claw piece 86b of the slide plate abuts against the small wheel 95, causing the ratchet wheel to rotate 1/8 in the illustrated embodiment.

Also, the eccentric cam that moves in unison with this small wheel is also 1/8.
Let it rotate.

The position of the movable carriage having the abutment pin 88 abutting against this eccentric cam, and thus the scanning body, facing the abrasive disk is thus changed.

This operation is repeated cyclically each time the scanning body is brought from the video disc side to the polishing disc side, so that the pink-up stylus is positioned to face a different polishing groove in sequence.

Further, when the scanning body is brought to the polishing disk side in this way, the plunger...-72 is actuated to lift the polishing disk upward together with the motor 71 as shown in the second figure. The stylus and the abrasive groove are brought into pressure contact with each other.

The starting and stopping of the motor 71 may be synchronized with the starting and stopping of the plunger, for example, and the polishing time may be selected to be several seconds required for one polishing of the stylus.

The plunger may be configured to control a microswitch, for example, when the scanning body is transferred to the polishing disk side, and to be activated every time the microswitch is controlled or every predetermined time of the control.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a partial configuration of a video disc player equipped with the apparatus of the present invention, FIG. 2 is a partially cutaway front view of the same player, and FIG. 3 is a sectional view mainly showing the shape of the abrasive disc. FIG. 4 is an assembled configuration diagram of a main part of a means for bringing the stylus of a pickup to face different grooves of a plurality of polishing grooves, and FIG. 5 is an explanatory diagram of the operation of the same means. Explanation of main drawing numbers, 8...Video disc, 70...
Polishing disk, 18...Scanning body, 61...Stylus.

Claims (1)

[Claims] 1. Positions facing each of a video disc which has a video signal or a video signal with an audio signal engraved and recorded in a spiral groove and whose rotation is controlled, and a polishing disc which has a plurality of concentric polishing grooves and which is rotationally controlled. a scanning body that is moved to and moved relatively close to and away from both disks, a pickup that is supported by the scanning body and includes a stylus that can be brought into pressure contact with both the grooves, and the scanning body is in the separated state. means for causing the stylus to face a position where it should be cyclically pressed against different grooves of the polishing grooves when the stylus is transferred from the video disc to the polishing disk; and means for bringing the stylus and the polishing disk into pressure contact. A stylus polishing device for a video disc player.