JPH0241829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a disc player that uses a reproducing stylus, and the present invention mainly relates to a reproducing stylus that reads signals recorded on a non-grooved capacitive video disc. This device relates to a stylus force control device that causes the stylus to move away from the stylus or, conversely, to descend to the disk surface.

Structure of conventional example and its problems FIG. 1 shows the structure of a regenerating needle. That is, a pick-up arm 4 including a regeneration needle 3 at its tip is held at the fixed ends 1a and 1b via a support rubber 2, and a magnet 5 is attached to the end of the arm 4 opposite to the regeneration needle 3. It is being When playing a disc, a current is applied to the coil 6 for applying stylus pressure to generate a magnetic field, and the magnet 5 is driven to lower the tip of the pickup and bring it into contact with the disc surface 7.

Conventionally, when lowering the needle, a current was passed through the stylus pressure coil, but when the stylus pressure was released, that is, the needle was removed from the disk surface, it was held at a position where the torsional strength of the support rubber 2 and the weight of the pick-up were balanced. Therefore, when assembling the pick-up, due to variations in the attachment of the support rubber to the fixed end, changes over time, etc., the tip is balanced at a lower position than the normal position, and as shown in Figure 2, the regeneration needle 3 is When it comes into contact with a device 8 outside the disk 7 or moves the pickup portion from a fixed position A to B on the disk when the disk is not being played back, it hits the groove guard 9 on the outer periphery of the disk 7. Since this groove guard 9 may be partially chipped, there is a high risk that the needle will be damaged if the groove guard 9 hits the disk 7 rotating at high speed. FIG. 3 shows a conventional example of a drive circuit for applying stylus pressure. This determines the optimum stylus force in the stylus force adjustment circuit 11 based on the stylus force ON signal 10, operates the drive transistor 12, and sends current to the stylus force coil 6.
When OFF, the transistor 12 is turned OFF and the current flowing through the coil 6 is stopped.

OBJECTS OF THE INVENTION An object of the present invention is to provide a disk player that can solve the problem of needle breakage caused by the drop of the balance position of the tip of the pick-up due to variations in the assembly of the pick-up, deterioration over time, etc. .

Structure of the Invention The disc player of the present invention has a magnet fixed to a pick-up case and a pick-up arm supported by an elastic material, and by passing current through a coil located above the magnet, the playing needle is moved onto the disc surface. and when the player is energized or at least the device for driving the stylus is energized and the reproducing stylus is being lowered to the disk surface, the coil is not used for regeneration. The present invention is characterized by the provision of a needle pressure control device that lifts the regeneration needle to an upper position by passing a current in the opposite direction to the direction in which the needle is lowered.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. It should be noted that the same reference numerals are given to those having the same functions as in the prior art, and the explanation thereof will be omitted.

FIG. 4 shows the movement of the playback needle in the disc player of the present invention. When the player is not energized, it is at position D where the support rubber 2 and the pick-up are balanced, but when the player is energized, the needle is lowered during playback. It is at a position E where it contacts the disk surface 7. When regeneration is completed, a current opposite to that used when the needle is lowered is supplied to the coil 6, so that the tip of the pick-up is lifted and held at position C, which corresponds to the upper mechanically limited stop 13.

FIG. 5 shows the configuration of the drive circuit. In accordance with the input stylus pressure ON/OFF signal 10, a polarity determining circuit 14 determines the direction of the current to be passed through the coil 6, and a stylus pressure adjustment circuit 15 adjusts the current to be passed.

Effects of the Invention As explained above, according to the disk player of the present invention, the structure is a little more complicated in terms of circuitry than the conventional one, and it is necessary to flow current even when not playing, but the holding current at the upper position is very small. This not only solves the problems that could lead to serious defects in the future in the conventional case, but also when the player is carried with electricity turned on and subjected to vibration, the pickup also vibrates up and down, causing the player to stop playing. Although there was a possibility that the needle would be damaged, this problem is almost solved by the present invention.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of the pickup, Figure 2 is an explanatory diagram of the movement of the hands during disc playback and other times.
FIG. 4 is a block diagram of a conventional needle drive circuit, FIG. 4 is an explanatory diagram of the operation of the needle of a disk player according to the present invention, and FIG. 5 is a block diagram of an embodiment of the needle drive circuit according to the present invention. 4...Pickup arm, 3...Regeneration needle,
5...Magnet, 6...Coil, 7...Disk, 1
4...Polarity determining circuit.

Claims (1)

[Claims] 1. A magnet fixed to a pick-up arm supported by a pick-up case and an elastic material is configured to lower a playback needle onto a disk surface by passing current through a coil located above the magnet, and When the player is energized, or at least while voltage is being supplied to the device that drives the needle, and the reproducing needle is being lowered to the disk surface, the reproducing needle is lowered to the coil in the opposite direction. A disk player equipped with a stylus pressure control device that lifts a reproducing stylus to an upper position by passing an electric current through it.