JPH0233734A - Prism actuator - Google Patents

Abstract

PURPOSE:To cause a magneto-optical head to be wholly compact and to attain the parallel tracking of plural laser beams by rotating and driving a prism, which is integrated into the magneto-optical head, with a simple substance. CONSTITUTION:A rectangular substrate 1 is fixed to the magneto-optical head and hinges 3 and 4 are fixed in the bottom surface side of the substrate 1. For the other edges of the hinges 3 and 4, aperture surfaces are fixed to a downward arm 2 and a prism 5 is fixed to the arm 2. When electrification is executed from a control part 15 to coils 10 and 11, the prism 5 is rotated in an arrow A or A' direction along a current direction. A prism position signal to be detected by sensors 12 and 13 is supplied from the sensors 12 and 13 to the control part 15 and the control part 15 compares reference position data, which are set in advance, and the prism position signal. Then, a current to the coils 10 and 11 is controlled so that the both data and signal can be coincident.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a prism actuator, and more particularly to a prism actuator for adjusting the position of a laser beam in a magneto-optical head.

[Conventional technology]

A conventional prism actuator uses two single-beam laser diodes on the head in a magneto-optical head to individually adjust the position of each laser beam of the laser diodes. Therefore, there is no one that uses a multi-beam laser diode that emits a plurality of beams from one laser diode, and there is no one that adjusts the position of a plurality of laser beams.

[Problem to be solved by the invention]

The conventional prism actuator described above is designed to align the laser beam emitted from a single-beam laser diode to a track on the disk, so the alignment of multiple laser beams emitted from a multi-beam laser diode is difficult. The drawback is that it cannot be done.

An object of the present invention is to provide a prism actuator that can position multiple laser beams on the same track on the same disk in a magneto-optical head equipped with a multihino laser diode that emits multiple beams from one laser diode. It's about doing.

[Means to solve the problem]

The prism actuator of the present invention includes a substrate having a rectangular upper surface for fixing to a magneto-optical head, and an arc integrally formed with the substrate on the bottom surface of the substrate via a plurality of hinges.
a prism suspended from the center of the arm and fixed to the arm; a pair of coils fixed to the left and right sides of the arm; and a magnetic circuit fixed to the bottom of the substrate at a predetermined interval on both sides of the coil. and a linear motor that rotates the prism by a predetermined angle in both directions about the hinge, and a sensor for detecting the position of the prism.

[Effect]

The present invention provides a linear motor that is formed by supporting a prism rotatably in both directions within a predetermined angle on a substrate attached to a magneto-optical head, and fixing a coil to the prism and placing it in a magnetic circuit. Incorporating a prism into the movable part,
By controlling the current flowing through the coil according to the designated position, high-speed access such as erasing, writing, and reproducing is possible, and parallel tracking of multiple laser beams is possible.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

1 and 2 are a front view and a side view, respectively, of an embodiment of the present invention.

As shown in FIGS. 1 and 2, this embodiment includes a rectangular substrate 1 whose upper surface is fixed to a magneto-optical head (not shown);
One ends of the two hinges 3 and 4 are fixed to the bottom surface side of the substrate 1 approximately at the center in the long side direction on a center line parallel to the short side direction of the substrate 1.

The other ends of the hinges 3 and 4 are fixed to an arm 2 having a U-shaped cross section and an opening facing downward, and a roof-shaped prism 5 is fitted into the arm 2 in contact with the U-shaped inner wall of the arm 4. Fixed.

The prism 5 has a structure in which it is fixed to the arm 2 and suspended by hinges 3 and 4 so that its roof-shaped inclined surface faces upward and is parallel to the long side direction of the substrate 1. E-shaped yokes 6 and 7 made of magnetic material are fixed to both sides of the bottom surface of the substrate 1 along the long sides of the substrate 1, and permanent magnets 8 and 9 are fixed to the inner surfaces thereof. On both sides of the arm 2, coils 10 and 11, which are formed by winding copper wire multiple times and shaped into a U-shape, are placed at a predetermined interval so as not to contact the inner wall surfaces of the yokes 6 and 7 and the end surfaces of the permanent magnets 8 and 9. It is fixed with.

Therefore, yokes 6 and 7, permanent magnets 8 and 9, and coil 1
0 and 11 constitute a linear motor, and the coil 10
and 11, the arm 2 including the prism 5 to which the coils 10 and 11 are fixed is moved to the hinges 3 and 4.
It can be rotated by a predetermined angle in the direction A or A' of the arrow shown in FIG.

Sensors 2 and 13 are provided below the prism 1 to detect the position at the end of the prism 1.
and 13 are fixed on a support plate]4 fixed to the lower end surfaces of the yokes 6 and 7.

Control unit 15 controls current to coils 10 and 11.

Now, when the coils 1.0 and 11 are energized from the control section 15, the prism 5 rotates in the direction of the arrow A or A' shown in FIG. 1, depending on the current direction. The prism position signals detected by the sensors 12 and 13 are supplied from the sensors 12 and 13 to the control unit 15, and the control unit 15 compares the prism position signal with preset reference position data and adjusts the coil so that the two match. Controls the current to 10 and 11.

In this embodiment, the rotation angle of the prism 5 is approximately ±5°.

〔Effect of the invention〕

As explained above, the present invention makes it possible to miniaturize the entire magneto-optical head by rotating the prism incorporated in the magneto-optical head, and to control multiple beams, so that erasing, writing and reproducing are possible. This has the effect of realizing high-speed access such as. Further, there is an effect that parallel tracking of a plurality of laser beams becomes possible.

[Brief explanation of the drawing]

1 and 2 are a front view and a side view, respectively, of an embodiment of the present invention. ]... Board, 2... Arm, 3, 4... Hinge, 5...
Prism, 6, 7... Yoke, 8, 9... Permanent magnet,
1.0,1.1 ・Coil, 12.13...Sensor,
14 support plate, 15... control unit.

Claims (1)

[Claims] A substrate with a rectangular top surface for fixing to the magneto-optical head,
an arm integrated with the substrate via a plurality of hinges on the bottom surface of the substrate; a prism suspended from the center of the arm and fixed to the arm; and a pair of prisms fixed to the left and right sides of the arm. a linear motor having a coil and a magnetic circuit fixed to the bottom surface of the substrate at a predetermined interval on both sides of the coil and rotating the prism by a predetermined angle in both directions about the hinge; and a linear motor for detecting the position of the prism. A prism actuator comprising: a sensor;