JPH097320A - Traverse drive mechanism apparatus - Google Patents

Abstract

PURPOSE: To obtain a traverse drive mechanism apparatus which enables fast accessing while achieving a lower power consumption of an optical memory. CONSTITUTION: A rack 3 is provided on an optical unit 2 carrying an optical head 1. A gear 4 meshed with the rack 3 serves as final gear of a gear train 10 decelerated from a pinion 6 pressed into a shaft of a motor 5. A pressing member 7 is provided to brake a bearing part 9 forcibly as pivoting one gear 8 in the gear train 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traverse drive mechanism device mounted on an optical memory device such as a CD-ROM drive.

[0002]

2. Description of the Related Art Conventional traverse drive mechanisms include a linear type using magnetic force, a lead screw type using a screw screw, and a rack and pinion type using a spur gear. However, when importance is attached to low power consumption and high speed access of the optical memory device, a rack and pinion type as shown in FIG. 4 is often used.

As shown in FIG. 4, in this device, a rack 3 is provided on an optical unit 2 having an optical head 1 mounted thereon, and a gear 4 which is screwed with the rack 3 is a motor 5 on a driving side.
As seen from the above, the final gear of the gear train 10 is decelerated from the pinion 6 press-fitted into the shaft of the motor 5.

A speed control method of a traverse drive mechanism for driving the optical head 1 in the radial direction of the optical disk 12 is as follows.
There are two types, one using a speed pattern of acceleration / constant speed / deceleration as shown in FIG. 5 and one using a speed pattern of acceleration / deceleration as shown in FIG.

In the former case, the track 13 of the optical disk 12 is
Since the optical head 1 is moved while counting
There is a limit to the speed at which the truck 13 can be traversed, which requires a constant speed time at maximum speed. In the latter case, as shown in FIG. 6, in addition to the configuration of FIG. 4, an encoder 11 is provided on the shaft of the motor 5, and the slit of the encoder 11 is used to determine the distance to the target track 14. Thus, there is no limit to the speed at which the truck 13 can be traversed. However, since deceleration is performed only by controlling the rotation of the motor 5, it cannot be rapidly decelerated, and as a result, as shown in FIG. 7, a long deceleration time for performing gentle deceleration is required.

[0006]

In the optical memory device product, it is required to increase the information reading speed. To this end, the optical head 1 is used as a target track 14
It is effective to reduce the time required to move the vehicle to the traverse drive time. However, in the conventional traverse drive mechanism device, the traverse drive time is long because the speed of traversing the track 13 is limited, and the deceleration time becomes long because the speed cannot be rapidly reduced, and as a result, the traverse drive time is increased. Has the problem of becoming longer.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a traverse drive mechanism device which can achieve low power consumption and further high speed access.

[0008]

In the traverse drive mechanism apparatus of the present invention, a rack is provided on an optical unit having an optical head, and a gear screwed with the rack is decelerated from a pinion press-fitted into a shaft of a motor. The final gear of the gear train is formed, and a braking portion for forcibly decelerating the gear train is provided in a bearing portion that supports at least one gear in the gear train.

[0009]

With the above construction, it is possible to accelerate the motor by maximizing the driving ability of the motor with low power consumption, move the optical head to the vicinity of the target track, and then rapidly decelerate it by using the braking means. By shortening the driving time,
The information read time can be further shortened.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, in the traverse drive mechanism apparatus of this embodiment, a rack 3 is provided on an optical unit 2 having an optical head 1 mounted thereon, and a gear 4 screwed with the rack 3 is provided.
Is the final gear of the gear train 10 decelerated from the pinion 6 press-fitted into the shaft of the motor 5. Further, at least one gear 8 in the gear train 10 is rotatably supported by a bearing portion 9 which is pressed by a pressing member 7 as a braking means so as to come in contact with and separate from the pressing member 7.

In the traverse drive for moving the optical head 1 to the track 14 in which target information is stored, first, the number of tracks which must traverse to the current position of the optical head 1 and the target track 14 position is obtained. . The acceleration time and the deceleration time of the traverse drive mechanism are calculated according to the number of tracks. The time distribution at this time takes into consideration the time during which the pressing member 7 can press the bearing portion 9 of the gear 8 and decelerate to the maximum with respect to the moving speed of the optical head 1. The optical head 1 is moved according to the firmware of the acceleration time and the deceleration time. Specifically, as shown in FIG. 4, the optical head 1 is moved to the vicinity of the target track 14 by accelerating by making the best use of the driving ability of the motor 5 with low power consumption. Then, at the apex, the output of the motor 5 is lost, and the pressing member 7 presses the bearing portion 9 of the gear 8. By doing so, the gear 8 is forcibly decelerated, and abrupt braking as shown in FIG. 3 is performed to forcibly stop the movement of the optical head 1. As a result, it is possible to shorten the time required for the traverse drive in which the optical head 1 traverses the target track 14.

[0013]

According to the present invention, it is possible to realize a higher speed access while reducing the power consumption of the optical memory device.

[Brief description of drawings]

FIG. 1 is a plan view of a traverse drive mechanism device according to an embodiment of the present invention.

FIG. 2 is a side view of a traverse drive mechanism device according to an embodiment of the present invention.

FIG. 3 is a graph showing an operation pattern of a traverse drive mechanism device according to an embodiment of the present invention.

FIG. 4 is a plan view of a traverse drive mechanism device according to a first conventional example.

FIG. 5 is a graph showing an operation pattern of the traverse drive mechanism device in the first conventional example.

FIG. 6 is a plan view of a traverse drive mechanism device in a second conventional example.

FIG. 7 is a graph showing an operation pattern of a traverse drive mechanism device in a second conventional example.

[Explanation of symbols]

 1 Optical Head 2 Optical Unit 3 Rack 4 Gear 5 Motor 6 Pinion 7 Pressing Member 8 Gear 9 Bearing Part 10 Gear Train 11 Encoder 12 Optical Disk 13 Track 14 Target Track

Claims (1)

[Claims] 1. A traverse drive mechanism device for moving an optical head for reading data information stored in an optical disc in a disc radial direction, wherein a rack is provided on an optical unit on which the optical head is mounted,
A gear that is screwed with the rack is configured to be a final gear of a gear train that is decelerated from a pinion that is press-fitted into a shaft of a motor, and a bearing that supports at least one gear in the gear train. A traverse drive mechanism device characterized in that a braking means for forcibly decelerating the gear train is provided in a portion thereof.