JP2872508B2 - Optical pickup feeder for optical disk player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup feeder for an optical disk player, and more particularly to an optical pickup feeder suitable for a compatible player capable of reproducing a compact disk and a laser disk.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional optical pickup feeder for an optical disk player. The figure shows a state where the compact disc 1 is clamped to the turntable 2 of the spindle motor 3. The optical pickup 4 is sent by the rotation of an optical pickup feed motor 10 via a pinion 12 and a rack 11.

[0003] The optical pickup 4 is a compact disc 1
A switch 5 is provided so as to operate when it is in the vicinity of the TOC (table of content). When the switch is turned on, an H signal is inputted to the CDSW input terminal of the controller 6.

A motor drive circuit is constituted by the controller 6, the switches 7, 8, the amplifier 9, and a tracking servo circuit (not shown). The amplifier 9 has a non-inverting input terminal (-) and an inverting input terminal (+) similarly to the operational amplifier.
The output voltage is set so that these voltages become equal, and the output voltage is applied to the optical pickup feed motor 10.

A resistor 13 is connected between the inverting input terminal (−) and the output terminal of the amplifier 9. A positive voltage is applied to the inverting input terminal (−) via the switch 7. -Voltage is applied. further,
A slider servo signal which is a DC component of a tracking error signal of the tracking servo circuit is applied. The non-inverting input terminal (+) of the amplifier 9 is connected to the ground.

The switches 7 and 8 are turned on and off by a signal from the controller 6. When sending the optical pickup 4 to the inner or outer circumference of the optical disk across the tracks of the optical disk, the controller 6 selects the switch 7 or the switch 8 to turn on. At this time, the slider servo signal output terminal of the tracking servo circuit has a high impedance.

In the above configuration, the compact disc 1
Immediately after the optical disk player is activated by the clamp, focus servo is applied to the optical pickup 4, the switch 7 is turned on by the controller 6, the switch 8 is turned off, and the slider servo signal output terminal becomes high impedance.

Accordingly, the output voltage of the amplifier 9 becomes negative, and the optical pickup 4 is sent to the inner peripheral side. Optical pickup 4
Is moved to the vicinity of the TOC of the compact disc 1, the switch 5 is turned on, and the TOC reading state is set. The controller 6 turns off the switch 7 and causes the tracking servo circuit to output a tracking servo signal. In this state, the optical pickup 4 is controlled and sent by the tracking servo circuit, and the TOC of the compact disc 1 is read. Note that data such as recording start time and recording end time for each track in the program area is repeatedly recorded in the TOC of the compact disc.

[0009]

In the prior art described above, when TOC information cannot be read due to disc contamination or the like, depending on the TOC information reading processing method of the player, the optical pickup is kept inside until the TOC information is read. The information is read while moving to. And
The width of the TOC of the compact disc is narrow, and in the case of a compatible player, the diameter of the turntable is large, and if the optical pickup moves a little, it hits the turntable and cannot move.

In this case, the output voltage of the motor drive circuit is applied to the optical pickup feed motor, so that the pinion for feeding the optical pickup causes tooth skipping, causing unpleasant gear noise, and speeding up gear consumption. was there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned point, and an object of the present invention is to allow a pinion to skip a tooth even if an optical pickup moves inward and cannot be mechanically moved. An object of the present invention is to provide an optical pickup feeding device for an optical disk player which does not occur.

[0012]

An optical pickup feeder for an optical disk player according to the present invention comprises: an optical pickup feed motor for feeding an optical pickup in a radial direction of an optical disk; a motor drive circuit for driving the motor; An optical pickup feeder comprising a switch for detecting that the optical pickup is located near the TOC position. When the switch is actuated, the optical pickup is located near the TOC position of the compact disk and is moving toward the center of the disk. The output voltage of the motor drive circuit is configured to be lower than at the time.

[0013]

According to the optical pickup feeder of the optical disk player of the present invention, when the TOC is repeatedly read, the optical pickup is in the vicinity of the TOC position of the compact disk before the optical pickup moves inward and comes into contact with the turntable. Is activated, and when the optical pickup is fed to the inner circumference side, the output voltage of the motor drive circuit decreases and the torque of the optical pickup feed motor decreases, so the optical pickup cannot be moved mechanically. As soon as the optical pickup feed motor stops, the pinion for feeding the optical pickup does not jump.

When the optical pickup is fed in the outer peripheral direction of the disk even when the switch is operated, the output voltage of the motor drive circuit does not decrease. Therefore, when reading the TOC or jumping one track at a time, the track number 1 is read. The optical pickup is stably sent by the DC component of the tracking error signal when searching for the start address of the optical pickup.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical pickup feeder for an optical disk player according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of the present invention. FIG.
In FIG. 2, portions having the same functions as those shown in the conventional example of FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the circuit shown in FIG. 1, the resistor 13 of the circuit shown in FIG.
Is connected in parallel with the diode 16, a series circuit of the resistor 14 and the switch 15, and the switch 15 is closed by the voltage applied when the switch 5 is closed.

In the above configuration, the compact disc 1
Immediately after the optical disc player is started
Focus servo is applied to the optical pickup 4, the switch 7 is turned on by the controller 6, the switch 8 is turned off, and the slider servo signal output terminal becomes high impedance.

In this state, the feedback resistance of the amplifier 9 is
3, the output voltage becomes-because the + power supply is connected to the inverting input terminal via the resistor, and the optical pickup 4 is sent to the inner peripheral side.

The optical pickup 4 is a compact disc 1
Move to the vicinity of TOC, switch 5 is turned on,
The controller 6 turns off the switch 7 and causes the tracking servo circuit to output a tracking servo signal. In this state, the optical pickup 4 is controlled and sent by the tracking servo circuit, and the TOC of the compact disc 1 is read.

At this time, the switch 15 is also turned on, and a series circuit of the resistor 14 and the diode 16 is added in parallel to the resistor 13, but the output voltage of the amplifier 9 is +. No current flows in the series circuit, and the slider servo signal is amplified with a high gain and the optical pickup feed motor 10 is driven.

When the start address of the track number 1 is searched while jumping one track at a time after the TOC is read, the switch 15 is still turned on and is in the same state as when the TOC is read. At this time, even if the reproducing surface of the disk is out of contact with the clamp surface and the DC component of the tracking error signal is smaller than normal, the slider servo signal, which is the DC component of the tracking error signal, is amplified with a large gain. Then, the voltage is applied to the optical pickup feed motor 10, so that the feed of the optical pickup does not stop.

When a TOC reading error occurs and the TOC is repeatedly read, the controller 6 controls the switch 7.
Is turned on, the switch 8 is turned off, and the optical pickup is returned to the disk inner peripheral side. At this time, the switch 5 is still on and the output voltage of the amplifier 9 becomes negative, so that a forward current flows through the diode 16 and the amplifier 9
Is a combined resistance value of the parallel circuit of the resistors 13 and 14 and becomes smaller. Since the absolute value of the output voltage of the amplifier 9 is proportional to the feedback resistance value, the absolute value of the output voltage of the amplifier 9 is smaller when the switch 15 is on than when the switch 15 is off. .

The output voltage of the amplifier 9 is set so that when the optical pickup 4 is mechanically stopped while the switch 15 is turned on, the optical pickup feed motor 10 is immediately stopped. It is possible by selecting 14 resistance values.

As described above, when the optical pickup 4 comes into contact with the turntable 2, the optical pickup feed motor 1
0 immediately stops and the pinion 12 does not jump. Further, when the optical pickup 4 is sent in the outer peripheral direction of the optical disk, the output voltage of the motor drive circuit becomes high, so that the optical pickup can be sent at a high speed. The optical pickup can be sent normally.

[0025]

According to the optical pickup feeder of the optical disk player of the present invention, when the optical pickup is fed in the inner circumferential direction of the disk at a position near the inner circumference of the disk, the output voltage of the drive circuit of the optical pickup feed motor is increased. Therefore, even if the optical pickup comes into contact with a turntable or the like and is mechanically stopped, the motor stops immediately and no gear tooth jump occurs. Therefore, unpleasant gear noise and gear wear are prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compact disc 2 Turntable 3 Spindle motor 4 Optical pickup 5 Switch 6 Controller 7 Switch 8 Switch 9 Amplifier 10 Optical pickup feed motor 11 Rack 12 Pinion 13 Resistance 14 Resistance 15 Switch 16 Diode

Claims (1)

(57) [Claims] 1. An optical pickup comprising: an optical pickup feed motor for sending an optical pickup in a radial direction of an optical disk; a motor drive circuit for driving the motor; and a switch for detecting that the optical pickup is near the TOC position of the compact disk. In the feeding device, the output voltage of the motor drive circuit is made lower by operating the switch when the optical pickup is near the TOC position of the compact disc and moving toward the center of the disc than at other times. Pickup device for optical disc players.