JPH0521326U - Optical information recording / reproducing device - Google Patents

Abstract

(57) [Summary] [Object] To obtain a structure for adjusting light incident on a movable optical system moved on a rail provided in a radial direction of an optical disk so as to be parallel to the rail. [Structure] Reflecting means (reflection prism) for reflecting light from a light source in a direction along a rail to a fixed optical system that makes light incident on a movable optical system that is moved along a rail extending on a base. 16 is provided, and this reflection means can be rotationally adjusted around its incident optical axis or reflected optical axis, and by this rotation, the reflected light can be adjusted to be parallel to the rail.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical information recording / reproducing apparatus (hereinafter, referred to as an optical disk apparatus) for reproducing information or recording / reproducing information on / from an optical disk such as a magneto-optical disk, and particularly to information recording provided in the circumferential direction of the optical disk. The present invention relates to an optical axis adjustment structure for adjusting the optical axis of light that is moved in a direction intersecting a track and is incident on a movable optical system that writes and reads information.

[0002]

[Prior Art]

 Generally, in an optical disc device, in order to write information to or read information from a large number of tracks provided on an optical disc, light emitted from a laser light source is imaged on the optical disc surface or reflected light from the optical disc surface. It is necessary to move the objective lens for detecting the optical axis in the direction crossing the track, that is, in the radial direction of the optical disk and in the direction close thereto. A configuration has been proposed in which the optical head is separated into a movable optical system and a fixed optical system in order to perform the movement in the substantially radial direction at high speed. For this reason, in the past, a rail was extended in the radial direction of the optical disc, a movable optical system including the objective lens was configured to be movable along this rail, and light from a fixed optical system was incident along the rail. The incident light is reflected by the movable optical system toward the optical disc surface, and an image is formed on the optical disc surface.

[0003]

[Problems to be solved by the device]

 In such an optical disk device, the fixed optical system and the movable optical system are separately configured, and since these are individually assembled on the device base, the fixed optical system may be different due to a mounting error between the two. Light from the system may not be incident parallel to the rail. As described above, when the incident light on the movable optical system is not parallel to the rail, the light beam is incident on the objective lens of the movable optical system in an oblique direction, which causes deterioration of the imaging performance on the optical disk surface. Alternatively, there is a problem that the light quantity distribution fluctuates in the inner and outer peripheries with respect to the objective entrance pupil, and correct and stable information recording and reproducing cannot be performed. An object of the present invention is to provide an optical axis adjusting structure capable of adjusting an optical axis of light incident on a movable optical system parallel to a rail.

[0004]

[Means for Solving the Problems]

 In the optical disk device of the present invention, the fixed optical system is provided with the reflecting means for reflecting the light from the light source toward the movable optical system along the rail, and the reflecting means is rotationally adjusted around its incident optical axis or reflection optical axis. It is configured to be possible.

[0005]

【Example】

 Next, the present invention will be described with reference to the drawings. FIG. 3 is a schematic configuration diagram showing the overall configuration of the optical disk device according to the present invention. In the figure, 1 is an optical disk, 2 is a movable optical system that is moved in the radial direction of the optical disk, and 3 is a fixed optical system that makes light enter the movable optical system 2. The movable optical system 2 has a carriage 5 that is moved along a pair of rails 4 extending in the radial direction of the optical disc 1, and a reflecting mirror 6, an objective lens 7, and an objective lens 7 are attached to the carriage 5. A two-dimensional actuator (not shown) for driving in the optical axis direction and the optical disc radial direction is mounted. The reflecting mirror 6 is composed of a prism and reflects the light incident parallel to the rail 4 vertically upward, and the objective lens 7 forms an image of the light reflected by the reflecting mirror 6 on the optical disc 1.

The fixed optical system 3 includes a laser diode 11 that generates laser light, a collimator lens 12 that makes the generated laser light into a parallel light flux, and an anamorphic prism that corrects the cross section of the parallel light flux into a substantially circular shape. 13 and 14, a half mirror prism 15 that splits the light from the anamorphic prism 14, and a reflection prism that reflects the light from the half mirror prism 15 in a direction parallel to the rail 4 and makes it enter the movable optical system 2. 16 are provided. In this structure, the light from the laser diode 11 is made into a parallel light flux having a required cross-sectional shape, and after passing through the half mirror prism 15, is reflected at a substantially right angle by the reflecting surface of the reflecting prism 16 and is parallel to the rail 4. Is ejected in the direction.

Further, FIG. 1 shows a control signal and information signal detecting optical system for detecting the light reflected by the optical disc 1. The light reflected and separated by the half mirror prism 15 is a 1/2 wavelength plate. After passing through 17, the light is condensed by a condenser lens 18, and the condensed light is branched by a polarization beam splitter prism 19 to be detected by the first sensor 20 and the second sensor 21. The position of the objective lens 7 of the movable optical system 2 is controlled according to the output of 21. Since this detection optical system is not directly related to the present invention, its detailed description is omitted.

The reflecting prism 16 is configured as a triangular prism having a 45 ° inclined surface as a reflecting surface 16a, as shown in a partially exploded perspective view in FIG. 1 and a longitudinal sectional view in FIG. 2, respectively. A round rod-shaped adjustment shaft 30 is integrally provided in the same axis direction as the shaft. The adjusting shaft 30 has an intermediate portion formed as a small-diameter portion 31, and an adjusting hole 32 penetrating in the radial direction is formed in the small-diameter portion 31. Then, the adjusting shaft 30 is placed in the taper groove 41 formed on the upper surface of the pedestal 40 provided on the base of the optical disk device, and both ends of the adjusting shaft 30 are fixed by the spring plates 34 fixed to the pedestal 40 by the screws 33. The upper side of 31 is elastically pressed to hold the adjusting shaft 30, that is, the reflecting prism 16 at a predetermined rotating position. A slit 35 is formed in the center of the spring plate 34, and the adjustment hole 32 is exposed to the outside through the slit 35. Then, the adjusting pin 50 as an adjusting jig is inserted into the exposed adjusting hole 32, and manually moved in the circumferential direction, so that the adjusting shaft 30 is rotationally adjusted about the axis. Accordingly, the reflection prism 16 can be rotationally adjusted around the reflection optical axis.

According to this configuration, as shown in the schematic perspective view of FIG. 4, when the adjustment prism 30 is used to rotate and adjust the reflection prism 16 around the reflection optical axis, the reflection surface 16 a is adjusted to be incident light. The surface angle with respect to the axis is changed, and the optical axis of the reflected light is changed in a substantially vertical direction and a horizontal direction at a minute angle. Therefore, it is possible to adjust the optical axis of the light incident on the movable optical system 2 to be parallel to the rail 4 only by adjusting the rotation of the reflecting prism 16. As a result, even if an assembly error occurs between the fixed optical system 3 and the movable optical system 2, it is possible to cancel the deviation of the optical axis due to the installation error by adjusting the rotation of the reflection prism 16 so that the optical disk can be eliminated. It is possible to reliably prevent the deterioration of the image forming performance for 1 and the fluctuation of the light amount at the inner and outer circumferences and to correctly record and reproduce the information.

Incidentally, as shown in FIG. 5, the adjusting axis 30 of the reflecting prism may be provided coaxially with the incident optical axis. Although not shown, a protrusion may be provided on a part of the circumference of the adjustment shaft, and the protrusion may be manually operated for rotation adjustment. Further, it is possible to attach a fixing means for fixing the adjusting shaft to the base after the adjustment.

[0011]

[Effect of the device]

 As described above, in the present invention, the fixed optical system is provided with the reflecting means for reflecting the light from the light source toward the movable optical system along the rail, and the reflecting means is provided around the incident optical axis or the reflected optical axis. The rotation of the movable optical system allows the light to be incident on the movable optical system to always be directed parallel to the rails, preventing deterioration of the image forming performance of the movable optical system on the optical disk and fluctuations of the light amount at the inner and outer circumferences. This has the effect of enabling correct recording and playback.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view of a reflection prism as a reflection unit.

FIG. 2 is a vertical sectional view of a reflective prism in an assembled state.

FIG. 3 is a perspective view showing a schematic configuration of an optical disk device to which the present invention is applied.

FIG. 4 is a perspective view for explaining the operation of the reflection prism.

FIG. 5 is a perspective view showing the operation of another reflection prism applied to the present invention.

[Explanation of symbols]

 1 Optical Disc 2 Movable Optical System 3 Fixed Optical System 4 Rail 7 Objective Lens 11 Laser Diode 16 Reflective Prism 30 Adjustment Axis 32 Adjustment Hole 34 Spring Plate 40 Pedestal 50 Adjustment Pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kanazawa 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Asahi Kogaku Kogyo Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. An optical information recording / reproducing apparatus provided with a movable optical system which is moved along a rail extending on a base and which images a light incident from the fixed optical system along the rail onto an optical disk. The fixed optical system is provided with a reflecting means for reflecting the light from the light source in the direction along the rail, and the reflecting means is configured to be rotationally adjustable around the incident optical axis or the reflected optical axis. Optical information recording / reproducing device.