JPH0590616U - Integrated optical head - Google Patents

Abstract

(57) [Abstract] [Purpose] High-speed access is achieved by aligning the center of linear drive with the center of gravity of the carriage system. [Structure] A light source 8 on the waveguide, an element having a deflection function,
Mirror means for vertically reflecting the light from the light source 8 to change the optical path, diffracting means for converging the light beam on the recording medium 1, and light receiving detecting means for detecting the signal light from the reflected light from the recording medium 1. 9 and the piezoelectric element 5 and the coil 6 are laminated and integrated on the lower surface thereof. Optical head is carriage rail 4
Move by. Alternatively, a magnet 7 is arranged below the coil 6 and is moved in the track direction by energizing the coil 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an integrated optical head, and more particularly to a drive coil and a carriage mechanism of an optical optical head used in an optical disk recording / reproducing apparatus for recording information on a rotating flat disk or reproducing already recorded information. It is a thing.

[0002]

[Prior Art]

 As a device for optically recording information on a concentric or spiral track formed on a rotating disk, or for optically reading and reproducing already recorded information, the information is uneven. There are already devices such as compact discs and optical video discs that record by using a light beam and irradiate it with a light beam to reproduce by utilizing the interference of light, or magneto-optical discs that record and reproduce by using the magneto-optical effect. It has been put to practical use.

The basic structure of one embodiment of high-speed access in these devices is a combination of a separation type and a linear motor as shown in FIG.

That is, a carriage system is formed by the objective lens 102, a lens actuator 101 that can be driven in two axes in the focus and track directions, and an optical head housing 120 having a reflection mirror, and is integrated into an optical system. Are separated as an optical unit 108, and a parallel line 108 is emitted from the optical unit 108.

The carriage system is supported on a carriage rail 103 by an optical head housing 120 and a carriage roller 104 rotatably attached to the housing 120, and the linear motor coil 10 is provided at one end of the optical head housing 120. 5 is equipped. The linear motor coil 105 is sandwiched between linear motor yokes 106.

As an operation, a predetermined amount of current by a control system (not shown) is passed through the linear motor coil 105, and the objective lens 102 is accessed by the propulsive force generated by the coil 105 and the yoke 106.

With the above configuration, high-speed access can be achieved, but as shown in the figure, the linear drive center 109 and the center of gravity 121 of the optical head housing 120 (= carriage system) do not coincide due to their weight balance. In contrast to the propulsive force generated by the linear motor, an unnecessary moment is generated in the carriage system, resulting in a large loss of the propulsive force of the linear motor.

In addition, mechanical vibration may occur and the vibration may propagate to the lens actuator, making it impossible to perform not only high-speed access but also normal reproduction operation.

Further, even in the integrated optical head, when a magnetic circuit is configured for driving focusing and tracking, the coil is configured to obtain a driving force in each of the above directions, so that miniaturization is impossible. Needless to say, upsizing was inevitable to maintain good gravity balance in each direction.

[0010]

[Problems to be solved by the device]

 As described above, in the conventional high-speed access using the separation type optical head, it was impossible to match the linear drive center with the center of gravity of the carriage system. Therefore, as described above, the linear motor propulsion force was not fully utilized.

That is, if the linear motor is driven rightward in the drawing (direction of arrow A) as shown in the figure, a thrust force is applied to the driving center of gravity of the linear motor coil in parallel with the yoke and in the direction of arrow A.

Then, this propulsive force generates a rotational force centering on the center of gravity of the carriage of the optical head housing, and a portion a of the optical head housing in contact with the carriage rail in the drawing front side a has a certain angle with the direction of arrow A. A force F in the direction of arrow C acts on θ, and a back portion b on the opposite side of part a has a certain angle λ with the direction of arrow B, and a force F in the direction of arrow D acts on it. .. Then, in these portions a and b, the drag force from the carriage rail on the optical head housing becomes large, and a friction force more than usual is applied when the optical head housing moves. Then, looking at the state of the propulsive force in the entire drive coil of this optical optical head, there are the propulsive force by the ordinary coil and the yoke, and the frictional force applied in the opposite direction to this propulsive force. If the frictional force is large, vibration occurs in the parts a and b, and this vibration propagates to the lens actuator etc., which hinders good access movement.

As described above, the center of gravity of the carriage and the center of the linear drive must coincide with each other, and at the same time, the size of the optical head must be reduced.

[0014]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a light source on a waveguide, an element having a deflection function, a mirror for reflecting light from the light source in a vertical direction, and a diffraction element for converging a beam on a disk, a disk. An optical control mechanism consisting of a light receiving element that detects the signal light from the optical head, which controls the distance between the disk and the optical head, and a coil on a film that can be driven in the tracking direction are laminated on the waveguide. Is.

[0015]

[Action]

 With the above configuration, when the center of the linear motor drive is aligned with the center of the carriage system, the size of the optical head can be reduced at the same time, and the rigidity of the optical head can be increased.

[0016]

【Example】

 An embodiment of the present invention will be described in detail with reference to FIGS. 1, 2 and 3. First, FIG. 1 is a perspective view of the overall structure of the integrated optical head of the present invention, FIG. 2 is a sectional view of the present optical head in focusing control, and FIG. 3 shows the shape of the coil of the present invention.

The integrated optical head 2 of the present invention is arranged so that the lower surface of the disk 1, that is, the recording medium of the disk 1 is irradiated with the beam 10 from the side on which the protective layer is formed. The optical head 2 includes a light source 8 on the waveguide, an element having a deflecting function, a mirror means for reflecting light from the light source 8 in a vertical direction, a diffraction element means for forming a minute spot on the disk 1, and a disk 1. And a light receiving element 9 for detecting the signal light from (see Precision Optics Magazine 56/3/1990).

The optical head 2 is provided with a carriage support portion for the carriage rail 4 as a guide for accessing the functional element and the track direction (arrow in FIG. 1). Therefore, with the above configuration, the optical head 2 is arranged so as to be linearly movable in the track direction.

Further, for example, a piezoelectric element 5 that is electrically expandable and contractible is laminated on the lower surface of the optical head 2, that is, the optical head 2 at a position facing the disk 1 with the optical portion interposed therebetween.

With this configuration, the piezoelectric element 5 moves the optical head 2 up and down to a predetermined minimum spot without defocusing the light beam 10 with respect to the surface wobbling of the disk 1. To be done. In the optical head 2 in which the piezoelectric elements 5 are laminated, a coil 6 on a film as shown in FIG. Further, a magnet 7 is arranged below the coil 6 with a minute gap therebetween. Therefore, a magnetic circuit is constituted by the magnet 7 and the coil 6 so that the entire optical head 2 can move in the track direction, and tracking control for following the eccentricity of the disk or the like can be performed.

In the case of focusing, the piezoelectric element 5 extends in the pressing direction and lifts the optical head 2 to the disk side.

As shown in FIG. 3, the coil for generating the driving force in the tracking direction does not increase the gravity of the film 7 and the optical head 2 in which the coil is formed in the shape of a helix, and high speed access is possible.

Further, according to the present configuration, the optical head 2 can have a simple configuration and shape without any protrusions or shapes, and therefore it is possible to design structural resonance at a high order.

[0024]

[Effect of the device]

 As described above, according to the present invention, (1) by integrating the optical head function, focusing drive function, and tracking drive function, the optical head can be made smaller, lighter, and more rigid, and at the same time as high-speed access. Miniaturization of the device can be achieved. (2) With the above configuration, it is possible to facilitate designing such as gravity balance and high rigidity, and it is possible to provide an inexpensive optical disk device.

[Brief description of drawings]

FIG. 1 is a perspective view of the overall configuration of an integrated optical head of the present invention.

FIG. 2 is a cross-sectional view of an optical head in focusing control of FIG.

FIG. 3 shows the coil shape of FIG.

FIG. 4 is a perspective view of a conventional separation type optical head.

[Explanation of symbols]

 1 disk 2 optical head 3 carriage support 4 carriage rail 5 piezoelectric element 6 coil 7 magnet 8 light source 9 light receiving element 10 light beam 101 lens actuator 102 objective lens 103 carriage rail 104 carriage roller 105 linear motor coil 106 linear motor yoke 107 parallel rays 108 optical unit 109 linear drive center 110 disk 120 optical head housing 121 carriage center of gravity

Claims (1)

[Scope of utility model registration request] 1. A light source on a waveguide, an element having a deflection function, a mirror means for vertically reflecting light from the light source to change the optical path, and a diffracting means for condensing the light beam on a recording medium. And an integrated optical head comprising a light receiving detection means for detecting signal light from light reflected from the recording medium,
An integrated optical head characterized in that an electric control mechanism such as a piezoelectric element capable of controlling a distance to a recording medium and a coil on a film which can be driven in a tracking direction are laminated on the waveguide.