JPH04341934A - Access mechanism for optical disk device - Google Patents

Abstract

PURPOSE:To make a movable part light in weight at the time when a magneto- optical disk device is accessed, to miniaturize a magnetic circuit and the device, and further to reduce draw-out lines from the movable part at the time of access. CONSTITUTION:A turnable rotationally driving a recording medium is made movable by a linear motor 12, and this turntable is driven by a belt driving method, and the structure is formed so that the turning motion can be always transmitted to the turntable even if a driving motor is fixed, then the access operation is realized while keeping an optical head fixed to a chassis base 5.

Description

Detailed Description of the Invention [0001] [Industrial Application Field] The present invention relates to an access control system used in an optical disc recording and reproducing apparatus for recording information on a rotating flat disc or reproducing information that has already been recorded. It is about the mechanism. 2. Description of the Related Art Devices that optically record information on concentric or spiral tracks formed on a rotating disk or optically read out and reproduce already recorded information are known. , compact discs and optical video discs that record information in the form of pits, irradiate them with light beams, and reproduce them using optical interference, and magneto-optical discs that record and reproduce information using magneto-optical effects. devices have already been put into practical use. The basic structure of one embodiment of high-speed access in these devices is an optical head as shown in FIGS. 3 and 4,
There are combinations of carriage and linear motor, etc. That is, a lens actuator 2 capable of driving the objective lens 1 in two axes in the focus and track directions, and an optical system that allows reading light to enter the lens actuator 2 and detects reflected light from the recording medium 3. A carriage system is constituted by the optical block 4 having the following. The carriage system has both ends connected to a carriage rail 53 via a sliding member 51 and a carriage roller 52.
, 54 so as to be movable in parallel in the radial direction of the recording medium 3. A linear motor coil 56 provided on the lower surface of the carriage 55 is sandwiched between a linear motor yoke 57. In operation, a predetermined amount of current is passed through the linear motor coil 56 by a control system (not shown), and the coil 56
The propulsive force generated by the yoke 57 causes the lens actuator 2 on which the objective lens 1 is mounted to perform an access operation. [0007] Although high-speed access is achieved with the above configuration,
Due to its detection method, the magneto-optical disk device is forced to use a complicated optical system, and as shown in the figure, the optical block portion 4 on the carriage 55, which is a movable portion during access, is large and heavy. Therefore, in order to access this optical head at high speed, a very large propulsive force of the linear motor 58 is required. [0008] As described above, in the access mechanism of the conventional magneto-optical disk device, the carriage on which the heavy optical head is mounted was used as the movable part. The magnetic circuit for driving the linear motor had to be made larger. Furthermore, in addition to the drive line for the linear motor, wires for laser diode oscillation and data detection must be pulled out from the carriage, which is the movable part, and the movable part is constantly dragging a large number of wires. The access operation was complicated. Means for Solving the Problems In order to solve the above problems, the present invention includes an optical head section including at least an objective lens, and an optical head section that is configured to irradiate or not irradiate the objective lens of the optical head section. an optical element means, an optical disk recording medium on which a light beam is converged and irradiated by the objective lens, a turntable on which this recording medium is mounted, a rotational drive means for rotationally driving the turntable, and a rotary drive means provided on the turntable. An access mechanism is provided, comprising a coil means, a magnetic circuit means for moving the turntable in parallel by the magnetic action of the coil means, and a support means for supporting the turntable so that the turntable can be moved in parallel. [0011] According to the above structure, the movably supported turntable moves in the radial direction of the disk relative to the optical head during the access operation, so that the access operation can be achieved even with a fixed optical head. [Embodiment] An embodiment of the present invention will be explained in detail using FIGS. 1 and 2. First, FIG. 1 is a partially transparent plan view showing an access mechanism of the present invention, and FIG. 2 is a partially transparent front view. An optical block having a lens actuator 2 capable of driving the objective lens 1 in the focus and track directions, and an optical system for making reading light incident on the lens actuator 2 and detecting reflected light from the recording medium 3. 4 are integrally fixed to the chassis base 5. The reading light emitted from the objective lens 1 is reflected by the recording surface of the recording medium 3, passes through the objective lens 1 again, returns to the detection section of the optical block 4, and detects an error signal and reproduces the read data. be exposed. The recording medium 3 is mounted on a turntable 6 and rotatably supported, and is rotationally driven by turntable drive gears 7 and 8 via a drive belt 9. Further, the turntable 6 has a drive coil 11 on its lower surface with the carriage 10 in between, and when the coil 11 is sandwiched between the yoke 13 of the linear motor 12, the recording medium 3 mounted thereon is generated by the propulsive force generated by the electromagnetic action. Move in parallel. At this time, since the turntable 6 is integrally constructed with the carriage 10 having a sliding member 14 and a carriage roller 15 at both ends, the distance between the recording medium 3 and the lens actuator 2 is maintained along the carriage rails 16 and 17. The disk moves while being slidably supported in the radial direction while maintaining the relationship. When reading distant data on the recording medium 3 (at the time of access), the turntable 6 moves in the disk radial direction by the driving force of the drive coil 11 on the lower surface of the carriage 10. drive belt 9
The spindle gear 18, which receives driving force from
A zero access operation is executed. [0017] According to the above invention, the disk rotation mechanism is a belt drive, and only the recording medium, turntable, and drive gear are the movable parts during access, which is different from the conventional method of moving a heavy magneto-optical head. Compared to this, the weight of the movable part can be reduced, the coil of the drive source and the magnetic circuit can be downsized, and furthermore, the only wire drawn out from the movable part is the electromagnetic coil drive line for moving the turntable. It has the effect of being able to.

[Brief explanation of drawings]

FIG. 1 is a partially transparent plan view of an embodiment of an access mechanism of the present invention.

FIG. 2 is a partially transparent front view of the access mechanism of FIG. 1;

[Fig. 3] Partially transparent plan view of a conventional access mechanism

[Figure 4]
Partially transparent front view of the access mechanism in Figure 3

[Explanation of symbols]

1 Objective lens 2 Lens actuator 3 Recording medium 4 Optical block 5 Chassis base 6 Turntable 7 Turntable drive gear 8 Turntable drive gear 9 Drive belt 10 Carriage 11 Drive coil 12 Linear motor 13 York 14 Sliding material 15 Carriage roller 16 Carriage rail 17 Carriage rail 18 Spindle gear 51 Sliding material 52 Carriage roller 53 Carriage rail 54 Carriage rail 55 Carriage 56 Linear motor coil 57 Linear motor yoke 58 Linear motor

Claims (1)

[Claims] 1. An optical head section including at least an objective lens, an optical element means for irradiating or not irradiating the objective lens of the optical head section with a light beam, and an optical disk recording medium on which the light beam is convergently irradiated by the objective lens. a turntable on which this recording medium is mounted; a rotation drive means for rotationally driving the turntable; a coil means provided on the turntable; and a magnetic action of the coil means to drive the turntable. An access mechanism for an optical disk device, comprising: magnetic circuit means for parallel movement; and support means for supporting the turntable so as to be movable in parallel.