JPS63152064A - Feeding mechanism for pickup - Google Patents

Abstract

PURPOSE:To simplify and miniaturize the composition of a circuit and to reduce the cost by converting the rotary movement of a motor into a linear movement via the speed reduction mechanism linked with the rotary shaft of a brushless motor and driving a pickup by this linear movement. CONSTITUTION:A speed reduction mechanism 3 is rotated as well with the rotation of a brushless motor 1, but at this time a pickup 4 starts to move linearly along a feeding rack 5 with moving a guide 6. Namely the rotary movement of the brushless motor 1 is reduced and converted into a linear movement and the pickup 4 starts to move linearly to enable a tracking control. At this time the driving force of the brushless motor 1 causes no knocking by rotating smoothly from a low rotary speed to high speed rotation and the pickup 4 performs a linear movement smoothly. A retrieval can directly be performed by controlling the brushless motor 1 only and a small sized and inexpensive pickup feeding controller is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pick amplifier feeding mechanism used for non-contact pickup of a disk such as an optical display player.

(Prior art) Searching for recorded information in conventional optical disc players uses a combination of a coarse search in which the entire optical head is moved to a rough position using a linear motor, and a fine search in which the optical head is then jumped by a pickup. .

First, the CPU reads the current address N, and then calculates the difference N from the target address N2 that is input.
By loading , from the CPU to the linear motor control circuit, the amount of adjustment of the linear motor is set. and,
In order to find out the amount of relative movement of the optical head, a rough search is performed while detecting the number and transverse direction of groove tracks crossed by the light beam until N3 becomes approximately 50 or less. After that, if there are less than 50, the process moves to a dense jumping search for pickups.

This means that the linear motor control system has a frequency band of 1
It has a low frequency of around 0 Hz, so it can only be used as a drive source for coarse searches because it does not have the tracking ability to drive the pickup directly to the destination address, and is configured to perform fine searches using a pickup with a frequency band of about 3 KHz. .

(Problem to be solved by the invention) Conventional tracking control has the above configuration, so even though the control direction of the linear motor and the jumping direction of the pick amplifier are in the same direction, it is difficult to drive the linear motor to perform coarse control. In order to perform a detailed search (search and further search by pickup), a control circuit is required for each, which results in a problem that the circuit becomes complicated and large, and the cost increases.

In addition, when using a brushed DC motor, there is a disadvantage that when switching the brush, the current is 0, and if the reduction ratio is reduced, the pickup operates in a step-like manner, making it impossible to smoothly feed the pickup, and if the reduction ratio is increased, the speed increases. It had the disadvantage of not being accessible.

The present invention aims to eliminate the above-mentioned drawbacks of the prior art and to provide a tracking control device which has a simple structure and can directly drive a bead to a predetermined track.

(Means for Solving the Problems) A tracking control device according to the present invention uses a brushless motor having relatively strong torque, and directs the rotational motion of the motor in a straight line through a damping mechanism connected to the rotating shaft of the brushless motor. This is converted into a reciprocating motion, and the converted linear motion drives the pickup to a predetermined position.

(Function) According to the tracking control device of the present invention, the knocking and jumping drive caused by the brushed motor of conventional pickups can be eliminated by direct search using the brushless motor, which simplifies the circuit configuration, reduces the size, and reduces costs. It has the advantage that it can be reduced.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, 1 is a brushless motor with relatively strong torque, 2 is its rotating shaft, 3 is a speed reduction mechanism whose one end is connected to the rotating shaft 2, and a transport mechanism 5 that sends the pickup along its length. has been established. The feed rack 5 is meshed with the speed reduction mechanism 3 and is configured to advance the pickup 4 by approximately 1.65 per rotation of the motor 1.

Next, its operation will be explained. Now, when the brushless motor 1 rotates, the deceleration mechanism 3 also rotates, and at this time, the pickup 4 begins to move linearly along the guide 6 while moving along the guide 6. That is, the rotational motion of the brushless motor 10 is decelerated and converted into linear motion, and the pickup 4 begins to move linearly, making tracking control possible. At this time,
The driving force of the brushless motor l rotates smoothly from low rotational speed to high rotational speed without causing knocking, and the pickup 4 moves linearly smoothly. According to this configuration, by simply controlling the brushless motor 1, in other words, by simply providing a drive control circuit for the brushless motor 1, a direct search can be performed, and a small and inexpensive pickup feed control device can be obtained. I can do it.

(Effects of the Invention) As described above, according to the present invention, a brushless motor is used, the rotational motion of the motor is converted into linear motion through a speed reduction mechanism connected to its rotating shaft, and the converted linear motion is used to pick up the motor. The design is configured to drive a planless motor that enables low-speed to high-speed rotation, allowing high-speed access with a small reduction ratio. Conventional coarse search and fine search are performed using separate drive circuits. This method has the advantage of simplifying the circuit configuration, reducing the size, and reducing costs compared to other methods, and its practical value is extremely great.

[Brief explanation of the drawing]

FIG. 1 is a top view of a tracking control device according to an embodiment of the present invention, and FIG. 2 is a side view of the same. ■...Brushless motor, 3...Deceleration mechanism, 4...Pickup, 5...9 feed tracks, 6...Guide, be

Claims (1)

[Claims] A pickup feeding mechanism that converts the rotational motion of the motor into linear motion through a speed reduction mechanism connected to the rotating shaft of the brushless motor, and drives the pickup by the converted linear motion.