JPS6174183A - Signal pickup device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a signal pickup device used in a reproducing device such as a video disc player that reproduces information signals from a rotating information recording disk.

Conventional configurations and their problems For example, in the case of a capacitive type reproducing device, a scanning element made of electrode material scans the signal track while contacting the information recording disk to statically eliminate mechanical irregularities on the signal surface. Extract it as a change in capacitance. The scanner is attached to the tip of the cantilever via a scanner holder, a magnet is attached to the other end of the cantilever, the vicinity of the magnet is supported by an elastic body, and the scanner is fixed to the cartridge case. With this structure, the scanner can freely rotate in the vertical and horizontal directions (in the radial direction of the signal track), and can also swing in the front-back direction (in the longitudinal direction of the cantilever).

However, this pickup device is designed so that it can be replaced as a cartridge when the scanning element reaches the end of its lifespan.

Normally, the playback stylus is in a retracted position inside the cartridge case, and the cartridge is attached to the playback device and is lowered by the stylus pressure application coil located above the cantilever magnet to obtain contact pressure against the information recording disk. be able to.

The tip of a regenerated needle has an extremely fine shape, and damage to the electrode forming part is particularly fatal. Further, the lead wires attached to the scanning element are also easily damaged. Therefore, sufficient care must be taken when handling the pickup cartridge.

Various devices have been devised to protect the scanning element or lead wires.

As a first example, a spring material is usually attached to hold the cantilever in the case, and when it is attached to the playback device, the lock is released by a protrusion inside the playback device. .

As a second example, the cantilever can move up and down, but
Some devices have a locking material fixed to the cartridge case to prevent the lead wire from stretching out and breaking even if the needle pops out.

However, in the first example, in addition to the locking material in the car IJ, a protrusion is required in the regeneration device, and the locking material itself is easily deformed, making it difficult to maintain positional accuracy. In the second example, it is not possible to prevent the scanner from popping out during normal handling, and to prevent this, a separate locking member or a scanner cover is required.

As described above, in order to ensure the locking state in the two positions when the scanning element is retracted and when it is released, the conventional protection device requires the following steps:
At least two parts are required.

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a pickup device that can protect the scanning element and lead wires in handling and reproducing the pickup cartridge, and can minimize the number of parts. It is something.

Structure of the Invention In order to achieve this object, the pickup device of the present invention has two states: a first state in which the scanning element is retracted into the cartridge case; If the cantilever is configured to be rotatable so that it can assume any of the second states in which it can be contacted, the locking member can self-maintain the locked state of the cantilever in either of these two states. It is configured as follows.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a state in which the scanning element is located at a first position and locked. FIG. 2 is a sectional view showing a state in which the scanning element is locked in a second position and is in contact with the information recording disk. FIG. 3 is a sectional view showing a state in which the scanning element is locked in the second position.

1 is a scanning element, 2 is a scanning element holder, 3 is a cantilever, 4
is a lead wire, 6 is a magnet, 6tri elastic support member,
7 is a cartridge case, 8 locking member, 9 is an arm base, 1Q is an information recording disc, and 11 is a turntable.

Note that the arrow in the figure indicates the rotation direction of the information recording disk. FIG. 4 is a perspective view showing the locking member in FIG.
FIG. 5 is a perspective view showing the locking member in FIGS. 2 and 3. FIG.

Eight locking members and a fulcrum boss 8b are rotatably attached so as to be inserted into holes in the cartridge case 7. This locking member 8 itself has sufficient elasticity to shorten the distance between both fulcrum boss portions 8b and insert it along the inner wall of the cartridge case.

First, in the state shown in FIG. 1, the first positioning click 8d provided on the locking member 8 is fitted into the positioning hole of the cartridge case and stopped. The cantilever 31i, the receiving portion 7a provided on the cartridge case and the locking member 8
It is held between the locking portions 8& of.

In the state shown in FIGS. 2 and 3, the locking member 8 rotates around the fulcrum boss 8b, and the second positioning click 8C is fitted into the positioning hole of the cartridge case and stopped. At this time, the cantilever 3 is in a state where it can be released to the outside from the cartridge case, and although not shown, the cantilever 3 receives the rotational force in the vertical direction by the stylus pressure applying coil located above the magnet 6. A scanning element can be brought into contact with the disc. Note that when the scanner is in contact with the information recording disk, the locking portion 8a- does not contact the cantilever.

FIG. 3 shows a state in which the cantilever is in contact with the locking part 81L, but in this case, the protruding position of the scanner is between the signal surface of the information recording disk and the top surface of the turntable, and the lead wire 4 is in a position where it is not fully extended, and when the playback operation starts without the information recording disk on it, or if the stylus pressure coil is accidentally activated in a place other than the information recording disk, the scanner or lead It functions to prevent wire damage. In addition, a safety stopper 8X is provided on the mooring member 8&, which prevents it from going too far when moved to each position.
It has a function that prevents the engaging part from pressing the cantilever.

As described above, according to this embodiment, one locking member made of a material with a certain degree of elasticity can self-maintain the locked state in either of the two positions required to lock the cantilever. can do.

Although not shown in this embodiment, it is also possible to consider a structure in which the fulcrum post 8b is cut and the locking member is rotated from the side wall using a screwdriver.

Effects of the Invention As described above, the present invention provides a locking member that can self-maintain the locking state at either the first locking position or the 20th locking position of the cantilever, thereby making it easier to handle and regenerate a single pickup cartridge. In both cases, the scanning element and lead wires are protected, the structure is simple and inexpensive, and the practical effects are excellent.

[Brief explanation of drawings]

1, 2 and 3 are cross-sectional views showing one embodiment of the pickup device of the present invention, and FIGS. 4 and 5 are
It is a perspective view which shows the locking member in the same Example. 1...Scanner, 3...Cantilever,
7... Cartridge case, 8... Locking member, 10... Information recording disc, 11...
··Turntable. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 figure

Claims (1)

[Claims] A first cantilever having a scanner at one end that scans the information recording disk and reads the information signal, and the scanner is positioned inside the cartridge case by rotation of the cantilever.
and a second state in which the cartridge can be moved out of the cartridge case and come into contact with the information recording disk. The cartridge case is provided with a locking member that is movable articulately between a first position for holding the scanning element in the state and a second position for regulating the amount of protrusion of the scanning element in the second state. A signal pickup device featuring: