JPS6151630A - Optical head device - Google Patents

Abstract

PURPOSE:To limit an angle of a light beam projected onto a disc within a permissible range with inexpensive constitution by providing a support mechanism supporting freely tiltedly an optical head and a means detecting the tilt of the disc to the head. CONSTITUTION:Photodetecting/light emitting elements 13-15 are provided in the disc radial direction and photodetecting/light emitting elements 17-19 are provided in the track direction onto the optical head 3, and a light beam 4 is projected to the disc 1. A support 26 supporting the head 3 freely tiltedly with a shaft 27 is supported freely tiltedly by a shaft 25 and a support 24. When the reflected light of the beam 4 from the disc 1 is made incident to the photodetecting/light emitting elements and the tilt in the radial direction and the circumferential direction of the disc to the head 3 is detected, a cam 28 on the support 24 and another cam on the support 26 are turned respectively and the disc 1 and the head 3 are subjected to correction control so as to be in parallel two-dimensionally. Thus, even if deformation of the disc and the fitting angle error of the head exist, excellent recording and reproduction is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical head device in a source disk device for recording or reproducing signals such as video and audio using an optical disk.

The conventional technology optical disk device converts the original beam into a disk VC! It is configured to directly project signals for recording or reproducing signals. For this reason, the optical head and the mounting mechanism had to be adjusted and constructed with high precision.

Problems to be Solved by the Invention However, if the device is configured and adjusted to a high fW degree, the device will inevitably become expensive. Furthermore, even if configured with high precision, there is a risk that the precision may deteriorate due to changes over time. Furthermore, if the disk is deformed due to warping or the like, even if the optical head is placed high, the original beam will not necessarily be projected perpendicularly to the disk. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an original head device that can easily keep the angle of the original beam projected onto a disk within an allowable range.

Means for Solving the Problems In order to achieve the above object, the optical head device of the present invention includes a tilt detecting means for detecting the inclination of the disk with respect to the optical head, and a tilt detecting means for detecting the tilt of the disk with respect to the optical head. It has a tilt correction mechanism that corrects the tilt of the head.

Function: If the optical head device is configured as described above, even if a relative tilt occurs between the disk and the optical head due to deformation of the disk due to disk fraying or mounting error of the optical head, this can be detected by tilt detection. Detection is made by a correction mechanism.Therefore, even if the precision of the optical disc and/or optical head device is poor, recording or reproduction can be performed with relatively high precision.Katcho Sakaki If so, high performance can be obtained even if the device is constructed at low cost.

Embodiment Next, a source disk device according to an embodiment of the present invention will be described with reference to FIGS. 1 to M5. The source disk device shown in FIG. 1 rotates a recording medium disk (1) with seven rotating devices (2), and a source beam (4
) is projected perpendicularly to 1, and the reflected light of 7 is detected.
The device is configured to read signals 9 by doing so.

The optical head (3) includes a laser beam (5), a beam tint 16J, a tracking control mirror (7J, an objective lens for focus control +87, and a photoelectric converter element (9)).
configured to optically read the signal,
Further, the disk (1) is configured to be fed in the radial direction of the disk (1) by a feeding mechanism (4). The optical head (31) further includes a disk radial tilt detector dll and a disk circumferential tilt detector u4 in connection with the present invention.

In the case of a radial tilt analyzer, the disk is arranged opposite to the disk 1, and one light emitting element (1) is arranged in the radial direction of the disk.
31 and two light receiving elements (141u51), the output terminal of the light receiving element (141t151 is connected to the first error multiplier 111i1 of the servo loose. It consists of one light emitting element αη and two light receiving elements α1 arranged in the circumferential direction, that is, the track direction, and the output terminal of the light receiving element α ray α field is connected to the second error amplifier 4 of the servo loose. There is.

The optical head +31 is supported by a gimbal support mechanism, and its tilt is corrected by a radial tilt control device [21] and a circumferential tilt control device. Radial tilt control device wi, I
2υ responds to the error output obtained from the first error amplifier (16) and controls the tilt of the pair of light receiving elements u [optical head +3 so as to equalize the outputs of 1ω]. The circumferential tilt control device z is a second error amplifier (20) 7)
- in response to the error output obtained from the pair of receiver elements (1
The tilt of the optical head (3) is controlled so as to equalize the output of 'll.

The gimbal support mechanism of the optical head (31) and the radial and circumferential tilt control device 1i t211&Z are constructed as shown in FIGS. The second support G61 is supported at the S (end) of Ml to the first support Qψ. The optical head (:3j) is rotatable around the first one, which extends in the tangential direction of the trunk.

The second support (
It is supported by c). Note that the second @(2η) extends in the radial direction of the disk 2.

A light emitting element (1) as a radial tilt detector (l) J is located near the projection part of the beam +41 on the upper surface of the optical head (31).
31, the light receiving element μ41 (151, and the light emitting element (L force) as the circumferential tilt detector u4 and the light receiving element block are arranged. In FIG. 1, the radial tilt control device is , consists of a first eccentric cam (to) shown in FIG. (3) is arranged between the first support body (C) and the second support body (C) on the left side of the first axillae in Figure 3; The first eccentric cam @ is closer to the stone in Fig. 3 than the first axis G (with respect to the first support Q).
and the second support U mark.

Note that this cam (2119) is formed so that the distance between the first support body (24+) and the second support body (c) can be gradually changed, and is coupled to the two first motors.・
Ru. The first motor is connected via the first drive circuit 311 to the output terminal of the first error amplifier u[i+ in FIG. )
control the angle of the

The circumferential inclination control device ρ2 in FIG. 1 includes the second eccentric cam 32 shown in FIG.
It consists of a motor rod, a second spring example, and a drive circuit M2. The second spring example is arranged between the support body 4 of M2 and the optical head t3+ with the 20th axis support also on the left side in FIG. 4, and the optical head +31 is rotated clockwise in FIG. biased in one direction. The eccentric cam 6z of M2 is the second 41]@
The cam (3Z) is disposed between the second support Cal and the optical head (31) on the right side in FIG. ) is connected to a second motor Q.The second motor Q valves a second drive circuit 65I to drive the second drive circuit 65I in FIG. error amplifier (20
1, and rotates in response to the error output to control the angle of the cam 64.

FIG. 5 shows the principle of detecting the radial inclination of the disk (11) with respect to the optical head (31. When the disk (11 is parallel to the upper surface of the optical head + 31, one light emitting element) is projected from the disk (31). The light spots on the disk are reflected by j and return toward the light emitting element as shown by the solid line I3η.

As a result, the left and right light-receiving elements (Fig. 5N) have almost the same light-receiving state. On the other hand, the disc crest is the optical head (3
When tilted as shown by the chain line with respect to 1, the light spot projected from the light emitting element Sumisan is reflected as shown between the chain lines, and the output of the light receiving element on the right side (151) is changed to the output of the light receiving element on the left side (141). On the other hand, if the disk (11) is tilted in the opposite direction to the state indicated by the chain line in Fig. The outputs of the pair of light receiving elements (14Iu51) are compared by the first error amplifier αe, and the output of the -10,000 light receiving element Shikozumi 4 is larger than the output of the other light receiving element (U).・If the output of the other light-receiving element (15) is greater than the output of one of the light-receiving elements, a negative output voltage will be generated, and if both outputs are equal. The output voltage becomes zero.Now, assuming that the relative inclinations of the disk +11 and the optical head +3 are as shown in Fig. 5, the first cam □□□ will be (3), and the second support and the optical head (3) also rotate counterclockwise to follow this rotation, and the tilt is eliminated.
Ru.

The tilt detection by the circumferential tilt detector and the second error amplifier is also performed on the same principle as the radial tilt detection. Also, the circumferential tilt correction is based on the same principle as the radial tilt detection. When a tilt is detected based on the comparison of the two light reception outputs by the second error amplifier, the second motor is activated in response to the tilt correction. As the cam rotates by a predetermined angle, the second cam B'l also rotates.As a result, the optical head (3) rotates clockwise or counterclockwise around -1 (2η) in FIG. The tilt will be resolved.

Although one embodiment of the present invention has been described above, the present invention is limited to this. - It is not something that can be changed, but it is something that can be further transformed. For example, inside the support of M2 and the optical head +31
The tilt may be controlled by a drive device using a drive coil used for focus control, tracking control, etc. of the original disk device. In short, M2
Any material may be used as long as it can change the inclination of the support I2 and the optical head (3).

``II Near: If the inclination is a problem in only one of the radial direction and circumferential direction of the disk fi+,
If you only correct one side, you can set it to 5 or 1.

Further, the inclination of the disk j and the optical head [31 may be detected using one light emitting element and one light receiving element. In this case, for example, the light-receiving element is formed into a wide-opening shape so that the amount of light received changes depending on the change in inclination.

Also, the distance between the disk +11 and the optical head (3) is set to 2.
It is also possible to detect the point and then detect the inclination based on the change in the interval between the two points.

Alternatively, the tilt may be detected using changes in capacitance.1. M.

The present invention can also be applied to a device that records optically by projecting a single light beam modulated by a signal onto a disk.

Effects of the Invention As is clear from the above, in the present invention, the tilt between the disk and the optical head is detected, and the tilt is corrected based on this. In other words, it is possible to perform good recording or playback even if the device has relatively low accuracy.

[Brief explanation of the drawing]

FIG. 81 is a block diagram showing an optical disk device according to an embodiment of the present invention, FIG. 2 is a diagram showing the optical head and its support mechanism of the device shown in FIG. 1, and FIG. 3 is a diagram showing the device shown in FIG. 2. FIG. 4 is a left side view of the device shown in FIG. 2, and FIG. M5 is a front view showing the principle of the relationship between the tilt detector and the disk. +11... Disc, (2j... Rotating device, (3;
...Optical head, +41... Original beam, U... Radial tilt detector, a Enoki... Circumferential tilt detector, En... Radial tilt 14il control device, 1221...・
Circumferential tilt control device, Q41...l-th support, (
26j...second support body, silent...first eccentric cam,
6shi...Second eccentric cam. Agent Nori Takano Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) An optical head that optically records or reproduces signals facing a recording medium disk; a head support mechanism that supports the optical head in a tiltable manner; and a tilt detector that detects the tilt of the disk with respect to the optical head. and a tilt correction mechanism for correcting the tilt of the optical head in response to a tilt detection signal obtained from the tilt detection means.