JPS60231959A - Disk elevating device of video disk player - Google Patents

Abstract

PURPOSE:To prevent a disk from deforming through simple circuit constitution by moving up and down the disk by utilizing the discharge of a capacitor which is charged to a source voltage for downward movement between two power sources which move up and down the disk. CONSTITUTION:If a power failure occurs while a support is elevated, a positive source voltage (Vcc) applied to the emitter of the 2nd PNP digital transistor (TR) drops, so the TR is cut off between the collector and emitter. At this time, a diode D1 is turned on with the negative charge from the capacitor C to hold the base potential of the 1st PNP digital TR17 minus, so the TR turns on. On the other hand, the emitter side of a PNPTR15 is also held at a minus potential by the capacitor C, so it turns on. Consequently, a transient current flows in the order of the earth 20, a DC motor 2, a resistance R4, the PNPTR15, and the capacitor C and a DC motor 2 reverses to disengage a drive gear 3 and a friction gear 7 from each other, thereby lowering the support.

Description

Detailed Description of the Invention (Prior Art) In a video disc player, it is necessary to load the disc into an appropriate position on the turntable during playback, and at the same time, it is necessary for the user to easily insert and remove the disc into the player body. It is necessary to be able to do it. Therefore, a support body that supports the center portion of the disk and is movable up and down is provided at the center of the turntable, and the support body allows the disk to be moved up and down.

That is, to insert a disc, the user places the center of the disc on the support that has been raised to the level of the disc insertion slot. Then, the disc is lowered together with the support from the height of the insertion slot to an appropriate position on the turntable, and then the playback operation is started. On the other hand, when the playback operation is finished, the disc is raised together with the support to the height of the insertion slot from which the user can take out the disc.

By the way, if a power outage occurs or the power switch is accidentally turned off while the disc is above the turntable together with the support, the motor that drives the vertical movement of the support will stop, and the disc will be The center portion remains supported by the support, and the disc may deform into an umbrella shape under its own weight, which may impede playback.

Conventionally, in order to eliminate this type of complex, a support lever that supports the disk was driven using a slide morph and a connecting solenoid, and when the power was turned off due to a power outage, etc.
A support lever that supports the disk is driven by using the connecting solenoid, and the connecting solenoid is disconnected.
Something that lowers the disc onto the turntable.

Furthermore, there are devices that use dedicated motors for raising and lowering the disk.

However, in this type of device, it is necessary to provide a motor separate from the motor for driving the support.

The circuit becomes complicated and costs increase.

(Object of the Invention) In view of the above, the present invention provides a capacitor that charges the power supply voltage of the lowering operation of the two power supplies that drive the disk up and down, and utilizes the discharge of the capacitor to raise and lower the disk. It is an object of the present invention to provide an elevating device for a video disc player that enables elevating and lowering and prevents deformation of a disc with a simple circuit configuration.

(Structure of the Invention) The structure of the present invention is one of two power supplies that operate a driving means for raising and lowering a support that supports the center of a video disc from the height of the disc insertion slot to the height of the turntable. The present invention relates to an apparatus in which a capacitor for charging the voltage is provided on the side of the power supply voltage that is to be operated to lower, and when the power supply voltage drops, the support body is lowered by a discharge current from the capacitor.

(Example) FIG. 1 shows a drive section 1 of a disk lifting device.

The drive unit 1 transmits the rotation of the DC motor 2 to the drive gear 3, and by the rotation of the drive gear 3.

A support (not shown) for supporting the disc is raised and lowered from the height of the disc insertion slot to the height of the turntable.

The DC motor 2 is a motor that can rotate in both forward and reverse directions, and the rotation of the DC motor 2 is transmitted to the gear pulley 6 through the motor pulley 4 and the drive heald 5. The gear boo IJ 6 is configured to constantly mesh with the friction gear 7, and a slip ring 10 provided on the pivot shaft 8 of the gear pulley 6 and the pivot shaft 9 of the friction gear 7 are connected via a clutch par 11. There is. On the other hand, the friction gear 7 and the drive gear 3 are always held in a positional relationship in which they do not mesh with each other by the thalassotile lever 11 until the DC motor 2 rotates forward (clockwise). moreover.

A damper gear 12 is meshed with the drive gear 3,
The speed of reverse rotation (counterclockwise) of the drive gear 3 is regulated by the inertial load of the damper gear 12 and the viscous load such as grease.

In the drive unit 1 having the above configuration, when the DC motor 2 rotates forward (clockwise), the clutch lever 11 rotates clockwise, and the friction gear 7 and the drive gear 3 are meshed (see Fig. 2). ) and the clockwise rotation of the clutch lever 11 is stopped.

Then, the rotational force of the DC motor 2 is transmitted to the drive gear 3, and the support body is raised to the height of the disk insertion slot.

On the other hand, when the DC motor 2 rotates in the opposite direction (counterclockwise), the thalassotile lever 11 rotates counterclockwise, and the friction gear 7
The meshing state between the drive gear 3 and the drive gear 3 is released, the drive gear 3 is rotated counterclockwise, and the support body is lowered to the height of the turntable. Note that the counterclockwise rotation of the drive gear 3 is not driven by the rotation of the DC motor 2.

This can be done simply by releasing the meshing state between the friction gear 7 and the drive gear 3.

FIG. 3 shows a control unit of a disk lifting device according to the present invention, which includes a CPU 13 and a motor drive circuit 14, and a control signal Sl output from the CPII 13.
, S2, the motor drive circuit 14 is activated to control the direction of rotation of the DC motor 2.

The motor drive circuit 14 is an NPN (range metal) 15. which performs push-pull operation with respect to each other. PNP transistor 16 and capacitors C and P provided on the negative power supply (-V, D) side
NP digital transistors 17a, 17b and NPN
Digital transistors 18a, 18b and diodes DI, D2. It is configured to include D3 etc.

The rLJ level control signal $1 and [HJ
When the level control signal S2 is output, the -th NPN digital transistor 18a is cut off, and the diodes Di and D2 become conductive due to the "H" level control signal S2. Since the potential on the base side of the transistor 17a becomes high,
The -th PNP digital transistor 17a is cut off.

NPN) The run disk 15 is also cut off.

Under such a state, the reset switch 21 connected to the emitter side of the second NPN digital transistor 18b is closed.

The rHJ level control signal S2 passes through the resistor R1 to the second N
Since the base current flows through the PN digital transistor 18b, the second PNP digital transistor 18b is rendered conductive. Therefore, a current flows from the positive power supply (Vcc') through the resistor R2, making the PNP transistor 16 conductive. Therefore, a current flows from the positive power supply (PNP) to the range metal 16 resistor R3 to the DC motor 2 to the ground 20, and the current causes the DC motor 2 to rotate forward (
clockwise) and the support is raised.

On the other hand, rHJ level control signal S from cr+u 13
1 and rLJ level control signal S2 are output, the -th NPN digital transistor 18a becomes conductive, and the collector side of the -th NPN digital transistor 18a, that is, the base side of the -th PNP digital transistor 17a, is at ground potential. becomes. Therefore, the -PNP digital transistor 17a, which has been in a cut-off state until now, becomes conductive, and a base current flows from the positive power supply (Voc) to the NPN) transistor 15 through the resistor R5, making the NPN) transistor 15 conductive. Therefore.

A current flows from ground 20 to DC motor 2 to resistor R4 to NPN) to run raster 15 to diode D3 to negative power supply <Vl)P), and the current causes the DC motor 2 to rotate in the reverse direction (counterclockwise) so that the support is lowered. 1 down (see Figure 2).

The reset switch 21 is a switch that prevents abnormal operations such as when the DC motor 2 rotates forward (clockwise) and raises the disc during playback operation of the player, and is only activated when the disc can be raised or lowered. It is designed to prevent a closed circuit.

Further, when the control signal S1 at the "H" level and the control signal S2 at the rHJ level are output due to a runaway of the CPU 13, the -th NPN digital transistor 18a
conducts, the anode side of the diode D2 becomes ground potential, and the above-mentioned "H" level control signals S1 and rL
The same operation as when the J level control signal S2 is output,
That is, the DC motor 2 is rotated in the reverse direction.

By the way, in the motor drive circuit 14 having the above configuration, if the power is turned off or there is a power outage while the support is rising, the positive power (Vcc) applied to the emitter of the second PNP digital transistor 17b is
) Since the voltage drops, the collector-emitter of the second PNP digital transistor 17b is cut off. At this time, the diode DI becomes conductive due to the negative charge stored in the capacitor C, and the base potential of the -th PNP digital transistor 17a becomes negative, so that the -th PNP digital transistor 1.7a becomes conductive. On the other hand, since the emitter side of the PNP transistor 15 is also set to a negative potential by the capacitor C, the PNP transistor 15 is rendered conductive. Therefore, earth 20 ~ DC motor 2 ~ resistor R4 ~ NPN
) A transient current flows from the run raster 15 to the capacitor C, and the DC motor 2 is rotated in the reverse direction by the current, the meshing state between the drive gear 3 and the friction gear 7 is released, and the support body is lowered.

Therefore, the capacitance of the capacitor C only needs to store the electric charge necessary to release the meshing state between the drive gear 3 and the friction gear 7.

In this example, since a drop in the positive power supply (Vcc-) voltage applied to the emitter side of the second PNP digital transistor 17b is detected, the CPU 13 outputs the ltJ level control signal S1 and the rHJ level level control signal S2. During the period of time, ie.

Even if the power is turned off due to a power outage while the disk is rising, the electric charge in the capacitor C will start discharging after the forward rotation of the DC motor 2 has completely stopped. It is not consumed in unnecessary operations other than rotation.

Further, the diode D3 provided on the negative power supply (Vpp) side can be omitted when the load amount of other circuits (not shown) other than the motor drive circuit 14 is small.

(Effects of the Invention) The present invention provides a lowering operation of two power sources for operating a driving means for raising and lowering a support body that supports the center of a video disc from the height of the disc insertion slot to the height of the turntable. This is because a capacitor is charged with the power supply voltage to be used, and when the power supply voltage drops, the support is lowered by the discharge current from the capacitor.

Even if a power outage occurs while the support is being raised or the power switch is erroneously turned to F, the center of one disk will not remain supported above the turntable and the disk will not be deformed. Further, since the lowering operation in the event of such an abnormality is performed by discharging the capacitor, the single circuit configuration can be simplified and an inexpensive player can be provided.

[Brief explanation of drawings]

The drawings illustrate embodiments of the present invention, and FIG. 1 is a plan view showing a state in which the friction gear and the drive gear are disengaged in the drive section of the disk lifting device of a video disc player, and FIG. FIG. 3 is a plan view showing a state in which the friction gear and the left drive gear are meshed. FIG. 3 is an electrical circuit diagram showing the control section. 1... Drive unit 2... DC motor 3... Drive gear 7... Friction gear 13...C
Pt1 14...Motor drive circuit 15...NPN
l-Transistor 16...PNP Transistor Applicant Sharp Corporation Fig. 1 δ Fig. 2 b σ Fig. 3 4!

Claims (1)

Claims: 1) A driving means for raising and lowering a support supporting the center of a video disc from the height of the disc insertion slot to the height of the turntable. two power sources for operating the drive means; A capacitor is provided for charging the power supply voltage of the one of the two types of sources that operates the support body in a lowering operation. A disk lifting device for a video disk player, characterized in that when a power supply voltage drops, the support is lowered by a discharge current from the capacitor.