JPH042463Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field 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.

2. Description of the Related Art In recent years, devices for reproducing information recording disks (hereinafter referred to as disks) (eg, video disks, etc.) have become widespread, and various pickup devices for signal reproduction have also been developed.

For example, in a capacitance type reproducing device, as shown in FIG. 4, a scanning element 5 with electrodes scans a signal track while touching the surface of a disk 9, and electrostatically removes mechanical irregularities on the signal surface. Take out as a change in capacitance. The scanner 5 is attached to the tip of the cantilever 3 via the scanner holder 4. A magnet 8 is attached to the other end of the cantilever 3, and the vicinity thereof is supported by an elastic support member 7. (not shown in FIG. 4). With this structure, the scanner 5
is rotatable in the vertical and horizontal directions (radial direction of the signal track) and swingable in the longitudinal direction of the cantilever.

Further, this pickup device is designed so that when the scanner reaches the end of its lifespan, it can be replaced in a cartridge type manner.

Normally, the scanning element 5 is located in a retracted position within the cartridge case 1, and when the cartridge is attached to the reproducing apparatus, it is lowered by the stylus pressure application coil 10 located above the magnet 8 of the cantilever 3.
A contact pressure is obtained against the disk 9, and reproduction is performed.

The tip of the scanning element 5 has an extremely fine shape, and even a slight breakage often causes fatal damage, and the lead wire 6 attached to the scanning element is also easily damaged. Therefore, sufficient care is required when handling this cartridge type signal pickup device.

Various devices have been devised to protect the scanning element or lead wires, and two typical examples will be explained with some reference to the drawings.

As a first example, as shown in FIGS. 5 and 6, the cantilever 3 is normally attached to a cartridge case 1.
A locking spring 13 is attached to lock the scanner so that it can be stored inside the playback device, and when it is attached to the playback device, the lock is released by a protrusion inside the playback device, allowing the scanner 5 to come into contact with the disk 9. There is.

As a second example, the cantilever can move up and down, but even if the needle pops out, a locking material (corresponding to the locking part of the locking spring in the first example) is used to prevent the lead wire from stretching out and breaking. There are some that have a cartridge case fixed to the cartridge case.

Problems to be Solved by the Invention However, in the first conventional example, in addition to the locking spring 13 in the cartridge case, a protrusion is required inside the playback device, and the locking spring itself is easily deformed, resulting in poor position accuracy. There is a problem that the locking position accuracy for controlling the amount of protrusion of the scanning element 5 cannot be maintained.

In addition, in the second conventional example, when the cartridge is placed on, for example, an iron plate with the front end of the scanner facing down and then picked up, the magnet is attracted to the iron plate, the elastic support member is stretched, and the magnet is further pulled away from the iron plate. If the scanner is pulled up until the magnet is pulled up, the magnet will jump into the cartridge case due to the restoring force of the elastic support member, and at the same time the scanner will fly out of the cartridge case due to the reaction, and there is a risk that it will collide with the steel plate and be damaged. There is.

Further, in either case, the elastic support member 7 and the magnet 8 are exposed when viewed from the bottom, and there is a disadvantage that they can be easily manipulated to cause the scanning element 5 to protrude.

In view of the above-mentioned problems, the present invention has been developed to provide a signal pick-up device that can protect the scanner and lead wires during both handling and playback operations of a cartridge-type signal pick-up device, and which can minimize the number of parts. The purpose is to provide

Means for Solving the Problems In order to solve the above problems, the signal pickup device of the present invention locks the cantilever so as to limit the amount of protrusion of the scanner when the scanner pops out from the cartridge case. A locking member is attached to the cartridge case, and has a portion that protects the elastic support member and a portion that covers and protects the vicinity of the elastic support member.

Effects The present invention allows the protrusion amount of the scanning element to be accurately controlled to an appropriate amount by the above-described configuration, and by protecting the elastic support member or the magnet part, the scanning element can be unnecessarily pushed out. It also eliminates the need to jump out.

Embodiment A signal pickup device according to an embodiment of the present invention will be described below with reference to the drawings.

1 and 2, 1 is a cartridge case, 2 is a locking member, 3 is a cantilever, and 5 is a cartridge case.
is a scanning element, 6 is a lead wire, 7 is an elastic support member, 8
is a magnet. FIG. 1 shows a state in which the locking member 2 is attached, and FIG. 2 shows a state in which it is removed. The locking member 2 is attached to the cartridge case 1 from the direction of arrow B in FIG. At this time, the inner protrusions of the locking member 2 are fitted into the square holes on both sides of the cartridge case 1, and the locking member 2 has sufficient elasticity to perform this operation.

3a to 3c show the operation of the signal pickup constructed as described above. 9 is a disk, 10 is a turntable, and arrow A indicates the rotation direction of the turntable and disk.

FIG. 3a shows a state in which the cantilever 3 is not moving downward and the scanning element 5 is housed within the cartridge case 1.

FIG. 3b shows a state in which the magnet 8 attached to the cantilever 3 receives a force from an upper stylus pressure application coil (not shown), causing the cantilever to descend and the scanning element 5 to be in contact with the disk 9 ( (playback operation status). Note that the scanner 5 is the disk 9.
When in contact with the cantilever 3, the locking member 2 does not contact the cantilever 3.

FIG. 3c shows a state in which the cantilever 3 is in contact with the locking member 2, but in this case, the protruding position of the scanner 5 is between the signal surface 14 of the disk and the upper surface 15 of the turntable, and lead wire 6
is in a position where it cannot be fully extended, and when the playback operation starts without the disk being placed, or if the stylus pressure application coil is accidentally activated in a place other than on the disk 9, the scanner element 5 and the lead wire 6. It has a function to prevent damage.

Furthermore, the locking member 2 has a shape that covers the elastic support member 7 and the magnet, so that it protects these members and also prevents the magnet 8 from adsorbing to the iron plate even if the cartridge is placed face down on, for example, an iron plate. This prevents the scanning element from flying out and colliding with the iron plate.

Effects of the invention As described above, according to the invention, a locking member that has both the function of locking the cantilever in an appropriate position and the function of covering and protecting the vicinity of the elastic support is attached to the cartridge case. This makes it possible to protect the scanning element and lead wires during both handling and reproducing operations of the cartridge-type signal pickup, and the number of parts can be kept to a minimum.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a signal pickup device according to an embodiment of the present invention, and FIG. 2 is a supplementary perspective view thereof.
3 is a sectional view showing the operation of the signal pickup device, FIG. 4 is a perspective view showing the reproduction operation of the signal pickup device, FIG. 5 is a perspective view showing the conventional signal pickup device, and FIG. 6 is a perspective view showing the reproduction operation of the signal pickup device. It is a supplementary perspective view. 1... Cartridge case, 2... Locking member,
3... Cantilever, 5... Scanner, 6... Lead wire, 7... Elastic support member, 8... Magnet,
11a, 11b...tracking coil, 12...
...TBC coil, 14...damper.

Claims (1)

[Scope of utility model registration request] A cantilever has a scanner at one end that scans the information recording disk and reads the information signal, and the other end is rotatably supported by an elastic support member fixed to the cartridge case. Regulating the amount of protrusion of the scanner when the scanner protrudes out of the cartridge case, and
A signal pickup device comprising: a locking member attached to the cartridge case so as to cover and protect the vicinity of the elastic support member.