JP2623830B2 - Optical pickup device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device in an optical information recording / reproducing apparatus, and more particularly to a method for mounting a photodetector thereof.

[Prior Art] FIGS. 3 to 8 show conventional apparatuses of this type. FIG. 3 is a cross-sectional view schematically showing the configuration of the optical information recording / reproducing apparatus, and FIG. 4 is a view showing a light spot on the information recording medium (optical disk). (2) is an optical disk, and (3) is a motor for driving the optical disk (2). In the optical system body (1), (4) is a light source, (5) is a diffraction grating, (6) is a half mirror, (7) is a collimating lens, and (8) is a light beam emitted from the light source (4). Yes, it passes through the diffraction grating (5), is reflected by the half mirror (8), and becomes a parallel light beam through the collimator lens (7).

(9) is an objective lens, (10a) is a focus driving device, (10b) is a track driving device, (11) is an information pit provided on the optical disk (2), and information content is stored depending on the presence or absence and length of a dent. Is done. (12) a light spot irradiated on the information pit (11) of the optical disk (2),
(13) is a sensor lens, and (14) is a photodetector.

(15) is reflected light from the optical disk (2),
The light passes through the half mirror (8) via the objective lens (9) and the collimator lens (7), and is focused on the photodetector (14) via the sensor lens (13). Reference numeral (16) denotes a holder in which the objective lens (9), the focus driving device (10a), and the track driving device (10b) are stored.

The optical pickup device is composed of the optical system main body (1) and the upper holder (16).

FIG. 5 is a perspective view showing an external configuration of the optical system main body (1) shown in FIG. 3, FIG. 6 is a sectional view showing a detailed internal configuration thereof, and FIG. 7 is a bottom view showing a bottom thereof. In each of the drawings, the same reference numerals as those in FIG. 3 denote the same parts, (17) denotes a flat portion provided below the optical system body (1), and (18) denotes a lens holder in which the sensor lens (13) is stored. , (19) are holding plates for holding the photodetector (14), and (20) are fixing screws for fixing the holding plate (19).

FIG. 8 shows the holding plate (19) on the optical system body (1).
Is a perspective view showing an operation for fixing and adjusting the position thereof, where (21) shows a set screw.

Next, the operation will be described. The light beam (8) emitted from the light source (4) is reflected by the half mirror (6) through the diffraction grating (5), passes through the collimator lens (7) and the objective lens (9), and is reflected on the optical disk (2). The surface is illuminated to form a light spot (12).

On the other hand, on the surface of the optical disk (2), information pits (11) representing information signal contents are sequentially arranged concentrically or spirally to form an information track, and the disk (2) is driven by a motor (3). The reflected light (15) rotated and diffracted according to the arrangement of the pits (11) passing through the information track reverses the incident optical path, passes through the half mirror (6), passes through the sensor lens (13), and passes through the photodetector (13). It is incident on 14), converted into an electric signal by the photodetector (14), and output. The information recorded on the optical disk (2) is reproduced by processing the output signal of the photodetector (14).

The output of the photodetector (14) can be used to detect a shift in the focus direction and track direction of the light spot (11) with respect to the information track. If a shift occurs, the focus driving device (10a ), The deviation is corrected by driving the objective lens (9) using the track driving device (10b).

As described above, the optical pickup device is provided with the optical disk (2).
It is necessary to accurately form an information spot (12) on the information pit (11) of the device, and it is necessary to accurately receive the reflected light (15) by the photodetector (14). When assembly accuracy becomes important and, for example, deviation occurs in each of the X, Y, and Z directions as shown in FIGS.
For displacement in the Z direction, slide the lens holder (18) to make adjustments and fix it with the set screw (21). For displacement in the X and Y directions, slide the holding plate (19). And adjust it with the fixing screw (20).

[Problems to be Solved by the Invention] Since the above-described conventional optical pickup device is configured as described above, the holding plate holding the photodetector is optically mounted by using at least two or more fixing screws. It is necessary to fix to the main body, the number of parts increases, and the assembling process becomes complicated. In addition, even if the position of the photodetector is set correctly during assembly, there is a risk of misalignment when tightening the fixing screw, and misalignment due to aging or environmental change due to residual stress even after assembly. There was a point.

The present invention has been made to solve this problem, and reduces the number of parts to simplify the assembly process.
It is an object of the present invention to provide an optical pickup device having a photodetector fixing means capable of accurately positioning and fixing a photodetector and minimizing occurrence of a shift due to aging or environmental change.

[Means for Solving the Problems] An optical pickup device according to the present invention uses an adhesive as a means for fixing a holding plate for holding a photodetector to an optical system main body, and first uses a cyanoacrylate-based instant bonding. This is temporarily fixed using an agent, and then permanently fixed using an ultraviolet curable adhesive.

[Operation] In the present invention, an adhesive is used as a means for fixing the holding plate holding the photodetector to the optical system main body. First, a temporary fixing is performed using a cyanoacrylate-based instant adhesive, and thereafter, Since the main fixing is performed using an ultraviolet-curing adhesive, there is no need to fix using fixing screws. After fixing, the two types of adhesives compensate for each defect and minimize the occurrence of displacement. It is possible to do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the configuration of an optical system main body in this embodiment, and FIG. 2 is a bottom view showing the bottom thereof. In each of the drawings, the same reference numerals as those in FIGS. (22) and (23) are adhesives applied between the optical system main body (1) and the holding plate (19), (22) is a cyanoacrylate instant adhesive, and (23) is 3 shows an ultraviolet curing adhesive.

As shown in FIGS. 1 and 2, the optical pickup device in this embodiment is provided with an optical detector (14) in an optical system main body (1).
The holding plate (19) for holding the two adhesives (2
It is assembled by bonding and fixing using (2) and (23).

In this embodiment, when the holding plate (19) is bonded and fixed to the optical system main body (1) using an adhesive, a cyanoacrylate instant adhesive (22) is first applied and temporarily fixed. After that, a UV-curable adhesive (23) is applied and fixed permanently.

The cyanoacrylate instant adhesive (22) is an instantaneous anaerobic adhesive of the instantaneous penetration type. It has a strong holding force in the direction perpendicular to the adhesive surface and a small coefficient of thermal expansion, but has the property of being weak at high temperatures. I have.

The ultraviolet curable adhesive (23) has a property of being cured by receiving ultraviolet light and heat.

Therefore, when assembling, the angle of incidence of the reflected light (15) incident on the photodetector (14) is adjusted and the holding plate (19) is adjusted.
Position, apply cyanoacrylate instant adhesive (22), and temporarily fix it to the optical system body (1) instantly.
After the temporary fixing, apply the UV-curing adhesive (23) and fix it permanently, so that two types of adhesives (22) and (23)
Can compensate for each other's defects, accurately position and fix the photodetector (14), and minimize the occurrence of deviation due to aging and environmental changes.

[Effects of the Invention] As described above, the present invention uses an adhesive as a means for fixing a holding plate for holding a photodetector to an optical system main body, and first uses a cyanoacrylate-based instant adhesive. Temporarily fixed and then permanently fixed with UV-curable adhesive, eliminating the need for fixing with fixing screws, reducing the number of parts, simplifying the assembly process, and aging. And minimizing the occurrence of shifts due to environmental changes, inexpensive and good productivity,
Moreover, there is an effect that a highly reliable device can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a configuration of an optical system main body position in this embodiment, FIG. 2 is a bottom view showing a bottom portion thereof, and FIGS. 3 to 8 are views for explaining a conventional apparatus. . (1) is an optical system main body, (4) a light source, (7) is a collimating lens, (14) is a light detector, (19) is a holding plate,
(22) is a cyanoacrylate instant adhesive, and (23) is an ultraviolet curing adhesive. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. An optical system main body which irradiates an information recording medium with an outgoing light emitted from a light source by using an incorporated optical system and condenses reflected light from the information recording medium by an incorporated sensor lens. A holding plate for holding a photodetector that converts reflected light into an electric signal, and fixing the holding plate to the optical system main body, wherein the optical system main body and the holding plate are provided with an adhesive. An optical pickup device, comprising: fixing means for fixing using a cyanoacrylate-based instant adhesive, and then fixing using an ultraviolet curable adhesive.