JPS6243241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information recording medium reproducing device, and when an operation is performed to open a reproducing needle exchange door of a pick-up device during playback, the door can be opened after returning the pick-up device to the rest position. The object of the present invention is to provide a playback device that can be operated safely.

The present applicant has proposed a disk-shaped information recording medium (hereinafter referred to as a video disk) having an electrode function in which information signals are recorded as changes in geometric shape without first forming a needle guide groove, and a disk-shaped information recording medium (hereinafter referred to as a video disk) having an electrode. We have proposed a reproducing device that reads and reproduces the information signal as a change in capacitance by relative sliding scanning with a reproducing needle.

As shown in Fig. 1, a disc case (not shown) containing a video disc is inserted into the insertion slot 2 of the playback device 1, only the disc is placed on the turntable 3, and the case is inserted. The disc is pulled out from the opening 2, and a pickup device 5 equipped with a playback needle 4 is moved in the radial direction of the turntable 3 to play the disc. The pick-up device 5 is located at a performance position A during performance, and is configured to return to a rest position B when the performance is finished. On the other hand, a regenerated needle exchange door 6 is provided in the case 1a above the rest position B, and the door 6 is configured so that it can be opened and closed by rotating around a hinge 8 by operating a set screw 7. has been done.

It is desirable that the door 6 cannot be opened during disc playback to prevent danger and to prevent the signal from the oscillator from being emitted to the outside.

The present invention satisfies the above requirements, and one embodiment thereof will be described below with reference to the drawings.

FIG. 2 shows a partial vertical cross-sectional view of a main part of an embodiment of an information recording medium reproducing apparatus according to the present invention, and in the figure,
Components that are the same as those in FIG. 1 are given the same numbers. In the figure, reference numeral 9 denotes a set screw, including a head 9a provided protruding from the top surface of the case 1a, a threaded portion 9b rotated by the rotation of the head 9a, and provided on the bottom surface of the door 6;
It is comprised of a nut part 9c provided with a rotation prevention mechanism that moves the threaded part 9b up and down by rotation of the threaded part 9b, and a ring 9d for preventing coming off. Note that the time required for the nut portion 9c to be displaced from the position shown in FIG. 2 to the position shown in FIG. It is set to the time required for the displacement to occur (3 seconds to 5 seconds).

Reference numeral 10 denotes a switch, and the actuator 10a is fixed by a suitable member at a position displaced by the vertical movement of the nut portion 9c, and is connected to a circuit for controlling the displacement of the pick-up device 5. 11
A key section is composed of a stopper section 11a and a pushing section 11b, and is attached to the lower surface of the door 6 so as to be biased in the direction of arrow C and rotatable about a rotation shaft 11c.

Nut part 9c, key part 11, actuator 1
0a is normally located at the position shown in FIG.
a', so that the door 6 cannot be opened. At this time, the switch 10 is in the on state, and a signal for enabling the pickup device 5 to move to the performance position A is taken out from the control circuit. Further, even during disc playback, the nut portion 9c, key portion 11, and actuator 10a remain in the positions shown in FIG. 2, and unless the head 9a is rotated,
The door 6 cannot be opened in this state.

The pick-up device 5 is in the rest position B, the nut part 9c, the key part 11, the actuator 10a
When the needle is in the position shown in FIG. 2, the head 9a is rotated in order to replace the regenerating needle 4. This results in
As the threaded portion 9b rotates, the nut portion 9c is displaced upward, the actuator 10a is displaced, and the switch 10 is turned off. When the head 9a is further rotated, the state shown in FIG. 3 is reached, and the nut part 9
c presses the push part 11b of the key part 11 from below,
The key portion 11 rotates clockwise about the rotation shaft 11c, and the stopper portion 11a is removed from the opening portion 1a', so that the door 6 can be opened.

Next, when the pickup device 5 is in the playing position A and the nut part 9c, key part 11, and actuator 10a are in the positions shown in FIG.
The case where a is rotated will be explained. Threaded part 9
When the switch 10 is turned off as described above by the rotation of b, a signal is supplied from the switch 10 to the control circuit, and the pickup device 5 returns from the performance position A to the rest position B. At this time, the head 9
The time required to displace the nut portion 9c from the position shown in FIG. 2 to the position shown in FIG. Therefore, after the pickup device 5 returns to the rest position B, it will be in a state as shown in FIG.

After the pickup device 5, which was in the playing position A, is returned to the rest position in this way, the door 6 can be opened. Further, the power to the circuit can be turned off by turning off the switch 10, so that even if the door 6 is opened, the signal from the oscillator will not be radiated to the outside.

Note that the set screw 9 does not necessarily have to be provided on the door 6, but may be provided at a position where the key portion 11 can be operated.

As described above, in the information recording medium reproducing apparatus of the present invention, it takes at least the time required for the reproducing needle exchange door of the pick-up device to go from the impossible state to the open state for the pick-up device to return from the playing position to the rest position. An operating section is set for the time required for Equipped with a locking mechanism that allows the pickup device to be opened, and a mechanism that outputs a detection signal by opening the operating section when the pickup device is in the performance position and returns the pickup device to the rest position. If a door opening operation is performed at a certain time, the pick-up device can be automatically returned to the rest position, and the door can be opened after completely returning to this rest position. It is safe because it can be done after rotation has stopped, and if the power to the circuit is turned off at the same time as the pick-up device returns to the rest position, the signal from the oscillator will not be radiated to the outside even if the door is opened. It has the following features:

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a general information recording medium reproducing device, and FIGS. 2 and 3 are part of a main part of an embodiment of the device of the present invention, showing a door-unopenable state and a door-openable state, respectively. FIG. 1... Information recording medium playback device, 1a... Case, 3... Turntable, 4... Playback needle, 5...
...Pickup device, 9...Set screw, 9a...
Head, 9b...Screw part, 9c...Nut part, 10
...Switch, 11...Key part, 11a...Stopper part, 11b...Pushing part.

Claims (1)

[Claims] 1. In an information recording medium playback device in which a door for replacing the playback needle is provided in the case body above the rest position of a pick-up device having a playback needle, the time required to bring the door from a state where it cannot be opened to a state where it can be opened. a door opening operation section whose opening operation time is set to at least the time required for the pickup device to return from the performance position to the rest position; a door latching mechanism that latches the door to place the door in the unopenable state when in the performance position, and unlatches the door to place the door in the openable state; An information recording medium reproducing apparatus comprising: a mechanism that outputs a detection signal by opening the door opening operation section when the pick-up device is at the performance position, and returns the pick-up device to the rest position. .