JPH04302825A - Photodetector device - Google Patents

Abstract

PURPOSE:To facilitate a positional adjustment and also to surely maintain the adjusted state. CONSTITUTION:At least a planar elastic body 21 mounted with a photodetector element 20 and a block 22 fixing one end of the planar elastic body 21 are provided, and the positional adjustment for photodetector element 20 in the Z-axis direction is realized by adjusting the elastically deformed amount of the elastic body 21 with an adjusting screw 27. Also, the positional adjustment in the x-axis and Y-axis directions are realized by making the block 22 to move in the direction orthogonally crossed with the Z-axis direction. The elastic body 21 is molded with a resin material to increase the strength against a crook or creep of the elastic body 21, thereby the photodetector element 20 is prevented from the subtle positional deviation and integration with other parts is also enabled.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photodetector device used in optical disk devices and the like.

0002

[Prior Art] In optical disk devices, semiconductor lasers
A laser beam emitted from the laser is guided to an optical disk via an optical system, and reflected light reflected by the optical disk is guided again to a photodetector device via the optical system to reproduce information recorded on the optical disk. The photodetector device used here includes a photodetector element that converts reflected light into an optical signal, and a fixing block for fixing the photodetector element.This block is fixed to the optical base of the optical disc device. It has become. This photodetector device is provided such that the in-plane direction of the fixed block is perpendicular to the optical axis direction of light incident on the photodetector element.

[0003] Such a photodetector device performs adjustment in two axes in a plane perpendicular to the optical axis direction by shifting the fixed block without completely fixing it, and focuses the reflected light on the photodetector element. The focal position is adjusted in the optical axis direction by moving a focusing lens for making light in the optical axis direction, thereby adjusting the focus to an appropriate position.

Conventional photodetector devices are adjusted using signals from the photodetector, and therefore it is not possible to individually adjust the position of the focal point on the photodetector in the optical axis direction and in the direction perpendicular thereto.

[0005] Therefore, it is necessary to simultaneously adjust the position of the focusing lens and the position of the photodetector mount to drive it into the correct position, and after driving it, the focusing lens and mount are fixed. The focusing lens is usually fixed by being held down by a holding plate spring or a push screw, and then fixed by adhesive.

However, when the focusing lens is held down by a holding plate or a push screw, it moves slightly in a direction perpendicular to the optical axis of the focusing lens. The focal position on the photodetector moves accordingly. On the other hand, since the spot position on the photodetector needs to be adjusted extremely accurately, the above-mentioned movement of the spot interferes with the adjustment work, and the adjustment work cannot be performed smoothly.

[0007]

[Problems to be Solved by the Invention] As described above, in conventional photodetector devices, the position of the focusing lens is adjusted during adjustment, so the focal position shifts when the focusing lens is fixed, which makes adjustment work difficult. There was the problem of becoming something.

The present invention has been made based on the above circumstances, and an object thereof is to provide a photodetector device which can easily adjust its position and can reliably maintain the adjusted state. There is a particular thing.

[0009]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a photodetector element, a plate-shaped elastic body molded from a resin material on which the photodetector element is mounted, and one end of the elastic body. A structure comprising: a block for fixing; and a moving means for moving the photodetector element in the plane direction and fixing it at an arbitrary position by displacing the free end side of the elastic body against the elastic force. This is what I did.

0010

[Operation] With the above-described configuration, the free end side of the plate-shaped elastic body on which the photodetector element is mounted is displaced against the elastic force, thereby moving the photodetector element in the first direction (plane direction). The remaining two-axis adjustment is achieved by sliding the block to which one end of the elastic body is fixed in parallel using a plane orthogonal to the first direction as a guide. In this way, it is possible to provide a photodetector device that can be easily adjusted.

Furthermore, since the elastic body on which the photodetector element is mounted is molded from a resin material, by filling the resin with carbon fiber or glass fiber, the strength of the elastic body against buckling or creep is increased, and the elastic body becomes more durable over time. It is possible to prevent subtle displacement of the photodetector element due to changes, and it is possible to maintain stable function over a long period of time.

Furthermore, it has become possible to integrate the elastic body with the block, insert mold the photodetector element itself, etc., reducing the number of parts and improving assembly workability.
It is possible to reduce manufacturing costs.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. Here, a photodetector device used in an optical disc device will be explained. FIG. 2 is a sectional view showing an optical system of an optical disc device to which the photodetector device 1 according to this embodiment is attached, and FIG. 3 is a side view of the same.

Laser beam emitted from semiconductor laser 2
The beam R is made into parallel light by the collimator lens 3, and the beam R is
The optical signal passes through the optical splitter 4 and is guided to an optical disk (not shown).

Then, the reflected light R' reflected by the optical disk
is guided to the photodetector device 1 according to this embodiment via the beam splitter 4, beam splitter 5, condensing lens 6, and cylindrical lens 7, and is converted into an optical signal and the information recorded on the optical disc is reproduced. be done.

In FIG. 2, reference numerals 8 and 9 indicate photodetector elements for adjustment. These members are attached to an optical base 10.

Next, the configuration of the photodetector device 1 will be explained with reference to FIGS. 1, 4 to 7. 4 is a perspective view of the assembled state, FIG. 5 is an exploded perspective view, FIG. 6 is a plan view of the assembled state, and FIG. 7 is a bottom view of the assembled state.

The photodetector element 20 is mounted approximately in the longitudinal center of an elastic body 21 formed from a resin material into a plate shape, and a fixing block 22 is placed over the elastic body 21. There is. The elastic body 21 is made of a plate spring formed into a substantially T-shape, and one end thereof is a fixing part 21a having two screw insertion holes.
The portion 1a is screwed to the block 22.

Furthermore, the photodetector element 20 is connected to a flexible printed circuit board 24 provided below the elastic body 21, so that the signal of the photodetector element 20 can be extracted.

Near the end of the elastic body 21 opposite to the fixed part 21a, that is, the free end side, the photodetector element 20 is placed on the surface by displacing the free end side of the elastic body 21 against the elastic force. A moving means 28 is provided for moving in the direction and fixing at an arbitrary position.

That is, a screw insertion hole 25 is provided near the end of the elastic body 21 opposite to the fixed portion 21a, that is, the free end side. On the other hand, the block 22 is provided with a screw hole 26 at a position corresponding to the screw insertion hole 25. As shown in FIG.
It is in a state where it is screwed together.

At this time, a gap G is formed between the opposing surfaces of the block 22 and the elastic body 22 on the free end side of the elastic body 21, and the adjustment screw 27
By screwing in the elastic body 21, the elastic body 21 is elastically deformed against the elastic force. The amount of deformation of the elastic body 21 can be arbitrarily adjusted by tightening the adjustment screw 27, and the photodetector element 20 can be adjusted in the Z-axis direction.

At this time, a hinge portion 30 consisting of a thin portion is provided near the joint of the elastic body 21 with the block 22, and due to the existence of this hinge portion 30, the deformation of the elastic body 21 mainly occurs at the hinge portion. It is designed to occur at the formation part of 30. Therefore, no stress is applied to the joint between the photodetector element 20 and the elastic body 21, and a stable joint can be maintained over a long period of time.

Furthermore, as shown in FIG. 1, a compression coil spring 31 is interposed in a recess 22a formed in correspondence with the screw hole 26 of the block 22. The free end position of the elastic body 21 is always in pressure contact with the head 27a of the adjustment screw 27 to prevent the adjustment position from going out of order, and the deformation at the hinge part 30 exceeds the elastic deformation region. Normal adjustment operation can be guaranteed even if the

Furthermore, a bent portion 32 is provided near the attachment portion of the photodetector element 20 of the elastic body 21 as a bending deformation preventing means for preventing bending deformation of this portion of the elastic body 21.
, 32 are formed.

Furthermore, the elastic body 21 is made of a resin filled with carbon fiber or glass fiber, which increases the strength against buckling or creep, and prevents slight displacement of the photodetector element 20 due to changes over time. is possible,
It is designed to maintain stable functionality over a long period of time.

Next, the adjustment operations in the three axes of the X-axis, Y-axis, and Z-axis in the photodetector device 1 having the above configuration will be explained.

First, adjustment of the photodetector element 20 in the Z-axis direction (optical axis direction), which is the first adjustment direction, is performed by adjusting the amount of deformation of the elastic body 21 by adjusting the tightening condition of the adjustment screw 27.

In addition, the remaining two axis directions, the X-axis direction and the Y-axis direction, are adjusted by moving the block 22 in the X-axis direction and the Y-axis direction along the joint surface between the block 22 and the optical base 10. To do something. The movement at this time is performed with the fixing screws 33 loosened.

According to such a configuration, adjustment in the Z-axis direction (optical axis direction) can be performed without moving the condensing lens 6, and moreover, the position in the Z-axis direction can be fixed by adjusting the position in the three-axis direction. After the rotation of the adjustment screw 27 is completed, adhesive or the like is simply applied to stop the rotation of the adjustment screw 27, so that the focal position does not move during fixation as in the conventional method, and can be easily adjusted.

In addition, when adjusting the Z-axis direction, the elastic body 21 is made of resin filled with carbon fiber or glass fiber, and has strong strength against buckling or creep. It is possible to prevent the photodetector element 20 from being slightly shifted in position due to this, and to maintain stable function over a long period of time.

Note that in the above-mentioned embodiment, the elastic body 2
1 and block 22 as separate members, the present invention is not limited to this. For example, the elastic body 21 may be integrated with the block 22, or the resin of the block 22 may be molded using a heat-resistant photodetector element 20. The photodetector element 20 itself may be insert-molded using a material having a relatively low temperature. This makes it possible to reduce the number of parts, improve assembly workability, and reduce manufacturing costs.

[0033]

As explained above, according to the present invention, the position of the photodetector element can be easily adjusted.

In addition, since the elastic body on which the photodetector element is mounted is molded from a resin material, by filling the resin with carbon fiber or glass fiber, the strength of the elastic body against buckling or creep is increased, and the elastic body becomes durable over time. It is possible to prevent subtle displacement of the photodetector element due to changes, and it is possible to maintain stable function over a long period of time. Furthermore, it is possible to integrate the elastic body with other parts,
This has various effects such as reducing the number of parts, improving assembly workability, and reducing manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a photodetector device of the present invention.

FIG. 2 is a sectional view showing an optical system of an optical disc device incorporating the photodetector device shown in FIG. 1;

FIG. 3 is a side view showing an optical system of an optical disc device incorporating the photodetector device shown in FIG. 1;

FIG. 4 is a perspective view of the photodetector device shown in FIG. 1.

FIG. 5 is an exploded perspective view of the photodetector device shown in FIG. 1.

FIG. 6 is a plan view of the photodetector device shown in FIG. 1.

FIG. 7 is a bottom view of the photodetector device shown in FIG. 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Photodetector device, 20... Photodetector element, 21... Elastic body, 22... Block, 25... Screw insertion hole, 26... Screw hole, 27... Adjustment screw, 28... Moving means, 3
0...Hinge part, 31...Coil spring.

Claims (1)

[Claims] 1. A photodetector element, a plate-shaped elastic body molded from a resin material and on which the photodetector element is mounted, a block for fixing one end of the elastic body, and a free end side of the elastic body made of an elastic body. A photodetector device comprising: a moving means for moving the photodetector element in a plane direction and fixing it at an arbitrary position by displacing it against a force.