JPS6316816B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a recording/reproducing element for a video disc, an audio disc, etc., and its main purpose is to provide a highly reliable and high-fidelity reproducing element. be.

(Prior Art and its Problems) There are two types of current digital signal reproduction methods for video discs and audio discs: optical and mechanical. The mainstream mechanical method is the contact capacitive method, and there are two types: without grooves (VHD method) and with grooves (CED method).
method).

To reproduce the digital signals engraved on a record disc, an extremely reliable reproduction element is required.

The principle structure of a conventional contact capacitance method is shown in FIGS. 1 to 3.

FIG. 1 shows the principle part of the reproduction section. disk 1
An electric signal is extracted from the signal 2 recorded on the electrode 4 as a capacitance using an electrode 4 attached to the needle tip 3.

5 and 6 are tracking correction signals, which are corrected so that the electrodes always trace signal 2. A is the disk movement direction, B is the tracking correction direction, C
indicates the jitter correction direction.

FIG. 2 is a diagram showing the principle of operation for performing such correction. The tracking correction coil 8 and the jitter correction coil 7 move the magnet 9 to control the needle so that it always reproduces the signal.

FIG. 3 shows the mechanism of the cartridge drive device. 3 is the needle tip, 10 is the cantilever, 1
1 is a suspension damper, 12 is a frame damper, 13 is a lead wire, and 14 is a base.

In this structure, a magnet 9 supported by a suspension damper 11 is corrected and controlled by a tracking correction coil 8 and a jitter correction coil 7.

In such conventional examples, the suspension damper is supported by a rubber suspension damper, and since the magnet is driven, the vibration fulcrum part is not clearly defined, and tracking correction,
Jitter correction controls interfere with each other, making correct control difficult. It also has drawbacks such as extremely poor temperature characteristics.

(Objective of the Invention) The present invention compensates for such drawbacks and provides a highly reliable digital signal reproducing element.

(Structure of the Invention) In order to achieve the above object, a cantilever holding a needle tip at the tip is bent through a damper part at one end of a shaft held approximately parallel to the disk surface by a plurality of leaf springs. They are freely combined to form a needle tip holding member, and a magnet for needle tip position correction is inserted into the holding member, and a tracking correction coil is installed on both sides of the cantilever, and a jitter is installed around the shaft at a distance from the shaft. The configuration includes a correction coil.

With this configuration, the tracking correction and jitter correction do not interfere with each other, improving the linearity between the current flowing through the correction coil and the correction amount, and furthermore, the jitter correction direction is parallel to the disk surface. Therefore, the contact of the needle tip with the disk surface is very stable.

(Example) An example of the recording/reproducing element of the present invention will be described using the perspective view of FIG. 4.

3 is a needle tip, 13 is a lead wire, 14 is a base, 15 is a sub-cantilever, 16 is a cantilever, 17 is a magnet, 18 is a damper, 19 is a leaf spring, 20 is a shaft, 21 and 22 are tracking correction coils. , 23 are jitter correction coils.

The cantilever 16 and the shaft 20 are joined via a damper 18, so that the cantilever 16 can swing freely in any direction relative to the shaft 20, and together with the sub-cantilever 15 constitutes a needle tip holding member. The shaft 20 is the base 14
The shaft 20 is held by two leaf springs 19 fixed to the base 14 through its center, and the shaft 20 is movable back and forth only in the axial direction with respect to the base 14. Jitter correction coils are concentrically wound around the shaft 20 at intervals. When a tracking correction signal is input to the tracking correction coils 21 and 22, the cantilever 16 is moved to the damper 18 by the action of the coils 21 and 22 and the magnet 17.
Tracking correction is performed by swinging around the portion , and when a jitter correction signal is input to the jitter correction coil 23, the shaft is moved only in the axial direction to perform jitter correction. Since the shaft 20 is held by the leaf spring 19 and is movable only in the axial direction and not in the lateral direction, the shaft 20 does not swing laterally due to the influence of tracking correction.
In addition, since the cantilever 16 is not laterally swung during jitter correction, both corrections do not affect each other, and each correction is performed independently, pure and accurately. Furthermore, since jitter correction is performed in a direction parallel to the disk surface, the state of contact with the tip of the needle can be maintained stably.

(Effects of the Invention) As described above, the present invention has the following excellent effects.

(1) The shaft is held at the center of two leaf springs,
Since the jitter correction coil is wound concentrically around the shaft at intervals, the jitter correction signal causes the shaft to move only in its axial direction, preventing the cantilever from swinging sideways. Even when a tracking signal is applied, the shaft does not swing sideways, and the cantilever only swings around the damper part.
Since each correction is not interfered with by other corrections, each correction is performed purely and accurately.

(2) Since the tracking correction drive system and the jitter correction drive system are independent of each other and do not interfere with each other, the linearity between the correction coil current and the correction amount is excellent, so correct correction can be performed. .

(3) Since the direction of jitter correction is parallel to the disk surface and parallel to the tangential direction of the track, the contact of the needle tip can be stabilized.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the reproduction part in the conventional contact capacitance method, Fig. 2 is a diagram of the operating principle of tracking correction and jitter correction in the conventional contact capacitance method, and Fig. 3 is the principle diagram of the regeneration part in the conventional contact capacitance method. FIG. 4 is a perspective view of one embodiment of the recording/reproducing element of the present invention. 1... Disc, 3... Needle tip, 13...
Lead wire, 14... Base, 15... Sub-cantilever, 16... Cantilever, 17... Magnet, 18... Damper, 19... Leaf spring, 20...
... Shaft, 21, 22 ... Tracking correction coil, 23 ... Jitter correction coil.

Claims (1)

[Claims] 1. In a recording/reproducing element for reproducing information recorded on a disk, a needle tip holding member, which is composed of a cantilever and a shaft that are refractably connected to each other by a damper portion, and which holds a needle tip at the tip of the cantilever, and a peripheral portion that is attached to the base. A plurality of leaf springs fixed to the base and holding the shaft substantially parallel to the disk surface, a needle tip position correction magnet inserted into the holding member, and tracking correction arranged on both sides of the cantilever. a coil for
A jitter correction coil is wound around the shaft at a distance from the shaft, and a tracking correction signal is input to the tracking correction coil to swing the cantilever around the damper part to perform tracking correction. A recording/reproducing element characterized in that the jitter correction signal is inputted to a jitter correction coil and the shaft is moved in the axial direction to perform jitter correction in the tangential direction of the track and in the direction parallel to the disk surface.