JPH04302826A - Photodetector device - Google Patents

Abstract

PURPOSE:To facilitate a positional adjustment and also to maintain a stable function hardly influenced by a dust or vibration. 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. The device is constituted so as to realize the positional adjustment in the X-axis and Y-axis directions by making the block 22 to move in the direction orthogonally crossed to the Z-axis direction. Also, a cylindrical packing 41 consisting of an elastic member is provided between the block 22 and elastic body 21 in this structure, thereby the dust intrusion into an optical path 36 is prevented and the vibration of elastic body 21 mounted with the photodetector element 20 is also prevented.

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, and 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 its object is to provide a photodetector that can be easily adjusted in position, and that is not easily affected by dust or vibration and can maintain stable functionality. The goal is to provide equipment.

[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 on which the photodetector element is mounted, and a plate-like elastic body that fixes one end of the elastic body and fixes the photodetector element. A cylindrical packing consisting of a block having a light introduction port to the element, and an elastic member interposed on the side of the block where the elastic body is arranged so as to tightly surround the optical path from the light introduction port to the photodetector element. 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. .

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, a cylindrical packing made of an elastic member is provided on the side of the block where the elastic body is arranged so as to tightly surround the optical path from the light introduction port to the photodetector element, thereby preventing dust from entering the optical path. This also prevents vibration of the elastic body on which the photodetector element is mounted. This prevents the optical system components from getting dirty over time and stabilizes the output signal.
It is possible to maintain stable functionality over a long period of time.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 4. 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).

[0014] 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 and 4. FIG. 1 is a sectional view of the assembled state, and FIG. 4 is a bottom view of the assembled state.

The photodetector element 20 is mounted on the back surface of a plate-shaped elastic body 21 and approximately at the center in the longitudinal direction, and a fixing block 22 is placed on the elastic body 21. The elastic body 21 is made of a plate spring formed into a substantially T-shape, and one end thereof is a fixed part 21a having two screw insertion holes.The fixed part 21a is attached to the block 22 with a set screw 24 It is designed to be fixed through.

Further, the photodetector element 20 is connected to a flexible printed circuit board (not shown) provided below the elastic body 21, so that the signal of the photodetector element 20 can be extracted.

The photodetector element 20 is placed near the end of the elastic body 21 opposite to the fixed portion 21a, that is, the free end side, 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. 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 slit 30 is provided near the joint of the elastic body 21 with the block 22, and the presence of this slit 30 causes deformation of the elastic body 21 to occur mainly at the portion where the slit 30 is formed. It has become. 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.

Further, 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. As shown in FIG. 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 slit 30 exceeds the elastic deformation region. Normal adjustment operation can be guaranteed even if the

Further, a bending 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. The bending prevention effect of these bent portions 32, 32 and the slit 3
Coupled with the effect of
By preventing any stress from acting on the joint between the photodetector element 20 and the photodetector element 20, it is possible to completely prevent subtle positional displacement of the photodetector element 20 due to changes over time such as creep.

Further, a cylindrical packing 37 is provided between the block 22 and the elastic body 21 and surrounding the optical path 36 from the light introduction port 35 to the photodetector element 20. This cylindrical packing 37 is formed from an elastic member such as rubber so that both ends have a large diameter, and one end surface is in pressure contact with the block 22 and the other end surface is in pressure contact with the elastic body 21.

Further, the cylindrical packing 37 is attached to the block 22.
The elastic body 21 is positioned by a rib portion 38 protruding from the elastic body 21 and a bent portion 32 formed on the elastic body 21 .

The reflected light R' that has passed through the cylindrical lens 7 enters the sealed space 40 formed in the optical base 10, the light introduction port 35 formed in the block 22, and the inner diameter part of the cylindrical packing 37. , is guided to the photodetector element 20 through the light introduction holes 41 formed in the elastic body 21, but by providing the cylindrical packing 37, the optical path 36
This prevents dust from entering the interior. In addition, it is possible to prevent the photodetector element 20, the cylindrical lens 7, and other optical system components from becoming dirty with dust over time.

Furthermore, since the end surface of the cylindrical packing 37 made of an elastic member such as rubber is always in contact with the elastic body 21, the elastic body 21 on which the photodetector element 20 is mounted is
vibration is prevented, and the output signal can be stabilized.

[0029] This makes it possible 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.

Further, 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, position fixation in the Z-axis direction can be performed 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.

Further, a cylindrical packing 41 made of an elastic member provided between the block 22 and the elastic body 21 prevents dust from entering into the optical path 36, and also prevents dust from entering the optical path 36. 21 vibration is prevented. As a result, the photodetector element 20,
The cylindrical lens 7 and other optical system components can be prevented from becoming dirty over time, and the output signal can be stabilized, making it possible to maintain stable functions over a long period of time.

In the above embodiment, the photodetector element 20 is attached to the back surface of the elastic body 21, and the cylindrical packing 37 is provided between the block 22 and the elastic body 21. As shown, the photodetector element 20 is attached to the surface of the elastic body 21, and the cylindrical packing 37 is attached to the block 22 and the photodetector element 2.
It may be provided between 0 and 0.

In short, it is sufficient that it is interposed on the side of the block 22 on which the elastic body 21 is arranged so as to surround the optical path 36 from the light introduction port 35 to the photodetector element 20 in a sealed state.

Furthermore, although the cylindrical packing 37 is formed with a large diameter on both ends, it may be formed with a small diameter on both ends, as shown in FIG. 6, for example.

In addition, it goes without saying that the present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the gist.

Note that the other embodiments described above (FIGS. 5 and 6)
), the same parts as in the previous embodiment are given the same reference numerals, and detailed explanation will be omitted.

[0040]

[Effects of the Invention] As explained above, according to the present invention, it is possible to provide a photodetector device whose position can be easily adjusted, and which is not easily affected by dust or vibration and can maintain stable functions. play.

[Brief explanation of the drawing]

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 bottom view of the photodetector device shown in FIG. 1.

FIG. 5 is a sectional view of a photodetector device showing another embodiment of the present invention.

FIG. 6 is a sectional view showing another example of a cylindrical packing that is a main part.

[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... Slit, 31... Coil spring, 35... Light introduction port, 36... Optical path, 37... Cylindrical packing.

Claims (1)

[Claims] 1. A photodetector element, a plate-shaped elastic body on which the photodetector element is mounted, a block fixing one end of the elastic body and having a light introduction port to the photodetector element, and the elastic body of the block. A cylindrical packing made of an elastic member interposed so as to seal the optical path from the light introduction port to the photodetector element on the side where the body is arranged, and a free end side of the elastic member against the elastic force. A photodetector device comprising a moving means for moving the photodetector element in a plane direction by displacement and fixing it at an arbitrary position.