JPS6243874A - Optical head feeding device - Google Patents

Abstract

PURPOSE:To increase the ratio of a high speed feeding speed to the fine feeding speed of an optical head and to improve the landing accuracy of the optical head to an object position by driving the 1st and 2nd drive motors via the 1st and 2nd reducing mechanisms having a different reducing ratio. CONSTITUTION:In throwing changeover switches 25, 26 to the position of a contact A, the 1st drive motor 10 is driven, a slide base 2 is slided via the 1st gear reducing mechanism (gears 9, 12) pinion gear 7 and a rack gear 6 and the optical head 1 is moved at high speed along an optical disc. The output shaft 17 of the 2nd drive motor 16 is driven synchronously via the 2nd gear reducing mechanism (gears 9, 13, 15, 18), the motor 16 acts like a generator, an electromotive force is inputted to a drive amplifier 23 via a resistor 28 and the drive motor 10 is subjected to a constant speed control. In throwing changeover switches 25, 26 to the position of a contact B and driving the 2nd drive motor 16, the optical head 1 is fed minutely via the 2nd gear reducing mechanism and the pinion gear 7 having a larger gear reduction ratio than that of the 1st gear reducing mechanism.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an optical head feeding device fltK,
In particular, it moves parallel to an optical disc placed under pressure on a rotating body, and transmits music and true signals to the optical disc.

The present invention relates to an optical head feeding device that records information such as a video signal or reproduces the information.

[Background of the invention]

A conventional optical head feeding device is, for example, disclosed in Japanese Patent Application Laid-Open No. 59-1
As described in Japanese Patent No. 98542, the power of one drive motor is transmitted to the optical head via a reduction gear train to move the optical head.

Therefore, the feed speed of the optical head is determined by the motor drive voltage,
Drive motor characteristics 9: Easily affected by variations in mechanical load, etc., and no consideration has been given to this. Moreover,
Since the reduction ratio of the reduction gear train is constant, it is difficult to increase the speed ratio between fine feed and high speed feed of the optical head, which is more difficult than the inherent performance of the drive motor.

[Purpose of the invention]

The present invention was made in order to eliminate the above-mentioned drawbacks, and its purpose is to easily increase the ratio between the high-speed feed rate and the fine feed rate of the optical head, and to stabilize the movement of the optical head. , it is an object of the present invention to provide an optical head feeding device with improved landing accuracy at a target position. [Summary of the Invention] In order to achieve the above object, the present invention provides a drive mechanism for driving an optical head with a reduction ratio. The first difference is the first speed reduction mechanism via the second speed reduction mechanism. The second drive motor is interlocked, and the driving force generated when one of the drive motors is activated causes the other drive motor to operate as a generator. ) The feature is that one of the drive motors is controlled at a constant level using the starting force.

[Embodiments of the invention]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a constant speed rotation control circuit diagram for controlling the rotation speed of a drive motor.

In FIGS. 1 and 2, the optical head 1 is mounted on a sliding base 2VC.
The slide table 2 is attached to the chassis 3 so as to slide in parallel along two guide shafts 4a, 4bK arranged in parallel with each other and the optical disk 5.

A pressure rack gear 6 is formed on the side surface of the slide table 2 so that its tooth surfaces are parallel to the guide shafts 4a and 4b. The shaft (driving shaft) of the second gear 7 that meshes with this rack gear 6
The large diameter gear 9 attached to the drive motor 8 has a small diameter gear 12 attached to the output shaft 11 of the first drive motor 0 and another small diameter gear 13.
are engaged. The large diameter gear 15 attached to the shaft 14 of the small diameter gear 13 has an output shaft 1 of the second drive motor 6.
The small diameter Zeya 1B attached to 7 is engaged.

The rack gear 6, pinion gear 7, and shaft 8 constitute a drive mechanism for the optical head 1. Further, the small diameter gear 12 and the large diameter gear 9 of the first drive motor 0 constitute a first reduction mechanism, and the small diameter gear 18, the large diameter gear 15, the small diameter gear 13, and the large diameter gear of the second drive motor 6 constitute a first reduction mechanism. 9 constitutes a second reduction mechanism, and both transmission mechanisms have different reduction ratios.

The terminals 19 and 20 of the first drive motor 0 and the second drive motor 16 are connected to a constant speed rotation 1ti11 circuit '21. As shown in FIG. 3, this constant speed rotation control circuit 21 controls an electromotive force proportional to the number of rotations generated at a terminal 20 of a second drive motor 6 that rotates synchronously with the first drive motor 0 through a switching circuit. Drive amplifier 25 via 22
It is configured to provide negative feedback to the input terminal 24 of the motor to obtain a constant speed.

The switching circuit 22 includes two changeover switches 25, 2.
6, the contact A of the first changeover switch 25 is connected to the input terminal 24 of the drive amplifier δ, and the contact B is connected to the input terminal 24 of the drive amplifier δ.
A contact BK of a changeover switch 26 is connected to the contact BK, and a middle point C is connected to a drive power source (not shown) via a resistor 27.

Further, the contact A of the second changeover switch 26 is connected to the resistor 28.
The drive amplifier 230 input terminal 24K is connected through the
The contact B is connected to the contact B of the first changeover switch 25, and the middle point C is connected to the terminal 20 of the second drive motor 16.

The two changeover switches 25 and 26 are interlocked, and the contact connections are configured such that contacts with the same symbol are connected to each other.

Next, the operation will be explained. Now, when the first and second changeover switches 25 and 26 are linked and turned on to the contact A side, power is supplied to the first drive motor 10 via contacts C and A of the first changeover switch δ and the drive amplifier 23. be done.

When the first drive motor 10 operates, this drive motor 1
The rotational speed of 0 is reduced by the tenth reduction mechanism (gear 812) and transmitted to the pinion gear 7.

Therefore, the pinion gear 7 rotates in a direction determined by the rotation direction of the drive motor 10, and the slide table 2 is rotated via the rank gear 6.
to move the optical head 1 along the optical disk 5 at high speed.

At this time, the pinion gear 7 synchronously rotates the output shaft 17 of the second drive motor 16 via the second reduction mechanism (gears 9, 13, 15, 18), and the second drive motor 16 generates electricity. operate as a machine.

Then, the electromotive force output from the second drive motor 16 connects the contacts C and A of the second changeover switch 26 to the resistor 2.
8 to the input terminal 24 of the drive amplifier 2S, the first drive motor 10 is controlled at a constant speed.

On the other hand, the first. When the second changeover switch 25, 26 is interlocked to close the contact B side and the second drive motor 16 is operated, the rotational speed of this drive motor 16 has a larger reduction ratio than the first reduction mechanism. The signal is transmitted to the pinion gear 7 via the second reduction mechanism. Therefore, the rotational speed of the pinion gear 7 becomes slow, and the optical head 1 is finely fed. At this time, the first drive motor 1o is driven via the first speed reduction mechanism and generates an electromotive force as a generator, but since the circuit is disconnected by the second changeover switch 26, The electromotive force is not supplied to the second drive motor 16.

In the illustrated example, the rotational force of the pinion gear 7 is transferred to the rank gear 6.
The information is transmitted directly to the sliding table 2 via the guide shaft 4.
A shaft is provided at both ends of a, and the end of the belt wound around the pulleys of both shafts is attached to the slide table 2.
Attach the above-mentioned first. to one of these two pulley shafts. Second
It is also possible to install a pinion gear that is interlocked with the lateral force of the reducer, and to transmit the rotational force of the pinion gear to the sliding table 2 via a belt.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the first drive motor is linked to the drive mechanism of the optical head via the first reduction mechanism, and the second drive motor is linked to the drive mechanism of the optical head via the first reduction mechanism. Since it is linked via a second reduction mechanism with a different reduction ratio, the reduction ratios of the two transmission mechanisms described above
It is easy to set a large ratio between the high speed of moving the optical head to the target position on the optical disk and the fine speed of movement during recording and reproduction.

In addition, when operating one of the drive motors to perform optical bending, the other drive motor is operated as a generator via a deceleration mechanism, and the generated electromotive force is used to drive the one drive motor at a constant speed. Since the optical head is controlled, the optical head can be stably moved and the accuracy of landing at the target position can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 5 is a constant speed rotation control circuit diagram for controlling the rotation speed of a drive motor. 1... Optical head, 5... Optical disc, 6
~8... Drive mechanism (Rakugya, pinion gear. Driving shaft), 9.12... First reduction mechanism (gear), 9, 13.1
5.18... Second reduction mechanism (gear), 10... First drive motor, 13... Second drive motor, 22... Constant speed rotation control circuit.

Claims (3)

[Claims] (1) an optical head that moves parallel to an optical disc placed on a rotating body to record information on the optical disc or reproduce the information; a drive mechanism that drives the optical head; The first gear is linked via the first speed reduction mechanism.
a second drive motor interlocked with the drive mechanism via a second reduction mechanism having a different reduction ratio from the first reduction mechanism, and power generation by the operation of one of the two drive motors. An optical head feeding device comprising: a constant speed rotation control circuit that controls one drive motor at a constant speed in response to an electromotive force of the other drive motor driven as a machine. (2) The optical head according to claim 1, wherein the drive mechanism includes a rack gear provided on the optical head side and a pinion gear provided on the driving shaft so as to mesh with the rack gear. Feeding device. (3) The constant speed rotation control circuit includes a switching circuit having two switches for switching the power supply circuits for the first and second drive motors, and a drive amplifier provided in the power supply circuit of the drive motor to be controlled at constant speed. An optical head feeding device according to claim (1), characterized in that it is comprised of: