JPH02158919A - Detector for reference position of pickup of disk device - Google Patents

Abstract

PURPOSE:To detect the movement of a pickup to a reference position with a smaller number of wirings without using a special means for detecting the reference position, such as switch, by devising the shape of a mechanical frame to detect the movement of the pickup to the reference position. CONSTITUTION:A disk 1 is rotated by a sliding motor 8 upon starting of the disk device 15. A microcomputer 11 outputs the control signal to move the pickup 4 to the innermost peripheral position of the disk 1 to a sliding driver 12. The motor 8 is run by the driving signal from the driver 12 and the pickup 4 is guided by a rail 5 by a circular gear 7 and a spur gear 6 and is moved in the central direction of the disk 1 by this rotation. The arrival of the pickup 4 at the innermost periphery in the information area of the disk 1 is detected by the contact of a conductor part 13 connected to the port for detecting the innermost peripheral position of the computer 11 and a pickup contact part 10a having a GND potential.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applied to a compact disc player or other such device that optically reads information signals recorded on a disc, and the optical pickup is located at the innermost circumference of the disc. The present invention relates to a pickup reference position detection device for a disk device that detects when a reference position such as a position has been reached.

[Conventional technology]

In general, a disk, which is the recording medium of a disk device, has
At the innermost circumference of the information area, so-called TOC (Table of Contents) information is recorded, which indicates the total number of information tracks on the disc, the total recording time, etc., and serves as a guideline for controlling the position of the pickup. Therefore, as shown in FIG. 3, when the disk device 20 is started, the disk 21 is rotated by the spin motor 22, and the pickup 24 for reading information on the disk 21 is moved to the inner circumferential side of the disk 21 by the slide motor 23. will be moved. And disk 2
Pick-up 24 to the innermost circumference in the information area 1
When the arrival of the TOC is detected by the innermost circumferential position detection means 24, the pickup 24 immediately stops and starts the next operation after reading the TOC information recorded at the innermost circumferential position of the information area. do. In this way, the conventional disk drive ff20 completes startup quickly after startup, making it easy to use.

[Problem to be solved by the invention]

However, in the conventional disk device 20, the innermost circumferential position detection means 25 for detecting the arrival of the pickup 24 at the innermost circumferential position of the disk 21 is generally constituted by a contact type switch. In such a configuration, it is necessary to secure space within the disk device 20 for mounting the switch. Therefore, this installation is subject to design constraints in order to secure space. Further, the use of the switch increases the number of parts, increases the cost of parts, and increases the number of steps for mounting the switch to the device, resulting in problems such as an increase in the cost of the disk device 20.

[Means to solve the problem]

In order to solve the above problems, a pickup reference position detection device for a disk device according to the present invention is provided with a rotating means for rotating a disk-shaped recording medium on a mechanical frame that is a supporting member of the disk device. In a disk device in which recorded information is read by a pickup moved by a pickup moving means, the mechanical frame has a reference potential, and when the pickup moves to the reference position, the conductor of the pickup A conductive pickup contact portion is formed to contact the
The above-mentioned pickup has a conductor part on the outer periphery, a predetermined detection potential different from a reference potential is applied to this conductor part, and the conductor part comes into contact with the pickup due to a change in the potential of the conductor part. It is characterized in that a detection means for detecting a state of contact with the part is connected.

[For production]

According to the above configuration, the pickup is moved to an arbitrary position on the disk-shaped recording medium by the pickup moving means, and reads information on the recording medium rotated by the rotating means.

On the other hand, when the pickup is moved and reaches the reference position, the conductive portion on the outer periphery of the pickup and the pickup abutting portion of the mechanical frame come into contact. The above reference position can be, for example, the innermost position of the recording medium where so-called TOC information is recorded. Here, the pickup contact portion has a reference potential, and a predetermined detection potential different from the reference potential is applied to the conductor portion. The reference potential mentioned above can be, for example, a ground potential.

When the two come into contact as described above, the potential of the conductor portion changes from the detection potential, and this change in potential allows the detection means to detect that the pickup has reached the reference position.

As mentioned above, in this detection device, the arrival of the pickup at the reference position is detected by the potential change of the conductor part due to the contact between the conductor part of the pickup and the pickup contact part formed on the mechanical frame. Therefore, with respect to a configuration in which a switch is provided as a reference position detection means, the design constraints of securing space are reduced. Furthermore, the number of parts is reduced, the increase in parts cost is also reduced, and the number of man-hours required for installation to the apparatus can be reduced.

〔Example〕

An embodiment of the present invention will be described below based on FIGS. 1 and 2.

As shown in FIG. 1, the disk device 15 has a slide motor 8 which is a pickup moving means for moving the pickup 4. As shown in FIG. This slide motor 8 connects a circular gear 7 to a flat gear 6 provided with a pickup 4.
The pickup 4 is moved by transmitting power through the . The flat gear 6 has teeth formed on the lower surface thereof meshing with teeth of a circular gear 7, so that rotation of the circular gear 7 causes linear movement in the radial direction of the disk 10 as a recording medium. It has become. At the innermost circumferential position in the information area of disk 1, there is a T
As the OC information, the total number of information tracks on the disc 1, the total recording time, etc. are recorded. At the top of the flat gear 6,
A pickup 4 is provided at the end on the rotating shaft 3 side.

The pickup 4 is guided by rails 5 to move the disk 1 in the radial direction. The above pickup 4 has a conductor portion 13 on the outer periphery,
This conductor portion 13 has a microcomputer 1 which will be described later.
1, a predetermined detection potential different from the ground potential (hereinafter referred to as GND potential) is applied.

Further, a conductive mechanical frame 10 serving as a supporting member is provided at the lower part of the disk device 15. The mechanical frame 10 includes a pickup contact portion 10a that comes into contact with the conductor portion 13 of the pickup 4 when the pickup 4 moves to the innermost position in the information area of the disk 1.
is formed. This pickup contact portion 10a is
The conductor portion 13 is arranged so that it can come into contact with the conductor portion 13 described above.
It protrudes upward to a height of . Further, the mechanical frame 10 is at the GND potential as a reference potential, and naturally the pickup abutting portion 10a is also at the ground potential.

A spin motor 2 as a rotation means is provided on the lower surface of the mechanical frame 10. The spin motor 2 has a rotating shaft 3 extending upward, and a turntable (not shown) for disposing the disk 1 is provided above the rotating shaft 3.

On the other hand, as shown in FIG. 2, the slide motor 8 is connected to a microcomputer 11 as a detection means via a slide driver 12 that serves as a power source for driving the slide motor 8. The pickup 4 is connected to the microcomputer 11 via a signal processing circuit 14, and the conductor portion 13 of the pickup 4 is connected to the innermost position detection port of the microcomputer 11.

And the conductor part 13 of the pickup 4 shown above,
The pickup contact portion 10a and the microcomputer 11 constitute a pickup reference position detection device.

In the above configuration, when the disk device 15 starts up,
The disk 1 is driven and rotated by the slide motor 8, and the microcomputer 11 outputs a control signal to the slide driver 12 in order to move the pickup 4 to the innermost position of the disk 1. The slide driver 12 that has received the control signal outputs a drive signal to the slide motor 8, and the slide motor 8 is rotated by this drive signal. When the slide motor 8 rotates, this rotation is transmitted by the circular gear 7 and the flat gear 6 as linear motion of the flat gear 6. Then, the pickup 4 arranged on the flat gear 6 moves toward the center of the disk 1 while being guided by the rail 5.

Thereafter, when the pickup 4 reaches the innermost circumferential position in the information area of the disk 1, the pickup abutting portion 10a of the mechanical frame 10 and the conductor portion 13 of the pickup 4 come into contact. As a result, the conductor portion 1 of the pickup 4
The potential of No. 3 changes from the detection potential to the GND potential of the pickup contact portion 10a. This potential change of the conductor portion 13 is input as a detection signal to the innermost position detection board of the microcomputer 11, and the arrival of the pickup 4 at the innermost position of the disk 1 is detected. Further, upon receiving the detection signal, the microcomputer 11 immediately outputs a control signal to the slide driver 12 to instruct the slide motor 8 to stop, thereby stopping the pickup 4.

The pickup 4 reads the TOC information recorded at the innermost circumferential position of the information area of the disc 1 and sends it to the microcomputer 11 via the signal processing circuit 14 . The microcomputer 11 then controls the position of the pickup 4 based on the read TOC information.

As mentioned above, in this pickup reference position detection device,
The arrival of the pickup 4 at the innermost circumferential position in the information area of the disk 1 is determined by contact between the conductor portion 13 connected to the innermost circumferential position detection boat of the microcomputer 11 and the pickup abutting portion 10a having the GND potential. It is detected by contact. Therefore, in a configuration in which, for example, a switch is provided as a means for detecting the arrival of the pickup 4 at the innermost circumferential position, the number of wires can be reduced from two to one. Further, it is also possible to incorporate the above wiring together with the signal line of the pickup 4.

〔Effect of the invention〕

As described above, in the pick-up reference position detection device for a disk device according to the present invention, the mechanical frame, which is a supporting member of the disk device, is provided with a rotation means for rotating a disk-shaped recording medium, and the rotation means for rotating a disk-shaped recording medium is provided. In a disk device in which information is read by a pickup moved by a pickup moving means, the mechanical frame has a reference potential, and when the pickup moves to the reference position, the mechanical frame contacts the conductive part of the pickup. A conductive pickup abutting portion is formed in contact with the pickup, and the pickup has a conductive portion on the outer periphery, and the conductive portion includes:
In this configuration, a predetermined detection potential different from a reference potential is applied, and a detection means is connected to detect the contact state between the conductor part and the pickup contact part based on a change in the potential of the conductor part.

Thereby, movement of the pickup to the reference position can be detected by devising the shape of the mechanical frame, that is, without using a reference position detection means such as a special switch. Furthermore, it is possible to reduce the number of wires required to detect movement of the pickup to the reference position. Therefore, it is possible to reduce the number of parts, parts cost, and work man-hours, and it is possible to reduce costs without impairing the functions of the device.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is an overall configuration diagram of a disk device, FIG. 2 is a block diagram showing main parts of a control system of the disk device, and FIG. FIG. 3 is an overall configuration diagram of a conventional disk device. 1 is a disk (recording medium), 2 is a spin motor (rotating means), 3 is a rotating shaft, 4 is a pickup, 5 is a rail, 6
7 is a flat gear, 7 is a circular gear, 8 is a slide motor (pickup moving means), 10 is a mechanical frame, 10a is a pickup contact portion, 11 is a microcomputer (detection means), and 13 is a conductor portion. Patent applicant Sharp Co., Ltd. 1 Zugyo 2

Claims (1)

[Claims] 1. A mechanical frame, which is a supporting member of the disk device, is provided with a rotating means for rotating a disk-shaped recording medium,
In a disk device in which information recorded on a recording medium is read by a pickup moved by a pickup moving means, the mechanical frame has a reference potential, and when the pickup moves to the reference position,
A conductive pickup abutting part is formed that comes into contact with a conductive part of the pickup, and the above-mentioned pickup has a conductive part on its outer periphery, and this conductive part has a predetermined detection potential different from a reference potential. 1. A pickup reference position detection device for a disk device, characterized in that a detection means is connected thereto and detects a state of contact between a conductor portion and a pickup abutment portion based on a change in potential of the conductor portion.