JPS61196486A - Signal pick up device - Google Patents

Abstract

PURPOSE:To absorb a distortion caused by a cartridge case and the like and a distortion due to an error in attaching a leaf spring support member by a coil spring and make a stable control operation possible by supporting an end of the leaf spring support member supporting a cantilever by a coil spring and applying constantly a fixed tension. CONSTITUTION:An end of a support member supporting a cantilever is fixed to an end of a coil spring. When a force T from an outside is applied to a cartridge case 6, a connecting section A of a support member and a coil spring is changed to a position of A'. Since a vertical stiffness Ks with respect to the cantilever 2 of the support member 5 is considerably largely set in comparison with the stiffness Kc of the coil spring, the stiffness Ks is substantially fixed and the external force T is absorbed by a change of the coil spring. In this manner, a distortion by an external force is absorbed by a coil spring, so that an influence applied to an axial control operation in a direction of the cantilever 3 is scarcely present.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a signal pickup for video discs that reads and reproduces recorded signals while a reproduction needle is in contact with a disc information recording carrier (hereinafter referred to as a disc). It is.

2. Description of the Related Art In general, the configuration of a signal pickup for reading and reproducing signals from a disk with a reproducing needle in contact with them while controlling the signals in the tracking direction and time axis correction direction is as shown in FIG. A regeneration needle 1 attached to the tip of the cantilever, a 7-ray lead 3 that guides the signal obtained from the regeneration needle to the signal processing circuit, a permanent magnet 4 attached to the rear of the cantilever, and a regeneration needle 1 attached to the tip of the cantilever. It is composed of a support member 6 that is rotatably supported in three axes directions including direction and time axis correction directions and is attached perpendicularly to the cantilever, and a cartridge case 6 that fixes the support member 6.

In order for the playback stylus to accurately obtain signals from the disc, it is necessary to control the stylus pressure to follow the disc's surface runout, warpage, etc., tracking control to follow the eccentricity and track distortion, etc. caused by eccentricity and uneven motor rotation, etc. The control operations in the three-axis directions of the time axis correction control are important, and the characteristics of the cantilever that is controlled and the support member that rotatably supports the cantilever in the three-axis directions have a great influence on accurate tracing ability.

Rubber-like viscoelastic materials have generally been used as supporting members to support the force/tilever, but metal plate springs have recently been adopted because trace performance is adversely affected by temperature characteristics, changes over time, etc. There is. This method of fixing the support member to the cartridge case using the metal plate spring is completely performed by adhesion.

Problems to be Solved by the Invention In the above-mentioned structure having a support member using a leaf spring,
Since the leaf spring support member is glued to the cartridge case, the tension of the leaf spring may change due to errors in installation when installing it to the cartridge case, or due to temperature changes after installation, case distortion due to changes over time, etc. , a problem arose in that it greatly affected the control characteristics in the three-axis directions.

The present invention solves the above problems and provides a signal pickup device that performs stable control operations.

Means for Solving the Problems The present invention is characterized in that one end of a support member that rotatably supports the cantilever is constructed with a leaf spring support.

Effect: With the above configuration, tension errors when the support member is attached to the cartridge case are absorbed by the leaf spring support. Also, even if external force is applied to the cartridge case,
This is absorbed by the leaf spring support, and the control operation of the cantilever in the three axial directions is greatly less affected.

Embodiment FIG. 1 shows an embodiment of the signal pickup device of the present invention and will be described. A cantilever 2, a regenerating needle 1 attached to the tip of the reproducing needle 2, a fly lead 3 that guides the information signal obtained from the regenerating needle, a permanent magnet 4 attached to the rear of the cantilever 2, and a regenerating needle 1 attached to the tip of the reproducing needle Pressure application direction/
A leaf spring support member 6 is rotatably supported in three axes directions, that is, a tracking direction and a time axis correction direction, and is attached perpendicularly to the cantilever 2, and a constant tension is applied to one end of the support member 6 to support the cantilever. It is composed of a coil spring 7 arranged to support the member. the other end of the coil spring 7;
The leaf spring support member 6 is fixed to the cartridge case 6.

A support member 6 for rotatably supporting the cantilever is attached to the cartridge case 6, and this vicinity is an important location for controlling the cantilever 2 in three axial directions. Therefore, at this location, a coil (not shown) for operating the permanent magnet 4 attached to the rear of the cantilever 2 and the cartridge case 6 are positioned, so that an external force may be generated. Furthermore, since the cantilever is operated in three axial directions, heat is generated by the coil, and the cartridge case e is susceptible to thermal deformation. For this reason, the third
As shown in the figure, in the conventional configuration, the support member that rotatably supports the cantilever 2 is completely fixed to the cartridge case 6. This has occurred as a change in the tension of the member 6. In order to solve the above problem, one end of a support member that supports the cantilever is fixed to one end of a coil spring, as shown in the principle diagram of FIG. When an external force T is applied to the cartridge case 6, the joint between the support member and the coil spring changes to the position M'.The stiffness Ks of the support member in the direction perpendicular to the cantilever is much greater than the stiffness KO of the coil spring. Since the stiffness Kl is set to be large, the stiffness Kl is almost constant, and the external force T is absorbed by the change in the coil spring. In one example, is 800 l/111M, to is 6-1017
/Wi1M Teal. As described above, since the strain caused by the external force is absorbed by the coil spring, it has almost no effect on the control operation of the cantilever in the three axial directions.

Effects of the Invention By supporting one end of the leaf spring support member that supports the cantilever with a coil spring and creating a structure that always applies a constant tension, the coil spring can absorb distortion caused by the cartridge case, etc., and distortion due to installation errors of the leaf spring support member. Absorbs well,
It is possible to perform stable control operations without adversely affecting the control characteristics in the three-axis directions.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the signal pickup device of the present invention, FIG. 2 is a principle diagram of the main part of the present invention, and FIG. 3 is a perspective view of a conventional signal pickup device. 1... Regeneration needle, 2... Cantilever,
3. River: Fly lead, 4: Permanent magnet, 6
...Plate spring support member, 6...Cartridge case, T...Coil spring. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3

Claims (1)

[Claims] A cantilever that is controlled and driven in three axial directions: a tracking direction, a time axis correction direction, and a stylus pressure application direction; and a support member disposed perpendicularly to the axial direction of the cantilever so as to rotationally support the cantilever; A signal pickup device characterized in that one end of the member is constructed with a spring support that applies a constant tension.