JPS6280839A - Optical information reproducing pickup and its assembling method - Google Patents

Abstract

PURPOSE:To prevent optical axis deviation by an optical information reproducing pickup by constituting a plate spring so that both end faces are fixed oppositely to side wall faces in a recessed groove. CONSTITUTION:A base 71b is fitted freely in the recessed groove 17 so that a detector 7 is inserted into a relief groove 12b, a plate spring 9b is fitted on it so as to be pressed in the slot 17, two fastening screws 101b are penetrated through holes 93b, 72b tightened to a screw hole 15b and the base 71b is fastened tentatively via the spring 9b. Then a prescribed pressure is exerted to the base 71b to fix it on the base mounting face 11b in the groove 17. In this case, a broadwise direction both end face 94 of the spring 9b is moved toward the face 11b along a wall face 16a while being opposed to both side wall faces 16a of the slot 17 and the spring 9b is not moved in a direction in parallel with the face 11b. Further, the entire lower face of the spring 9b, especially a mounting part of the screw 101b presses the base 71b in a direction of the face 11b. Thus, the base 71b is depressed in the optical axis direction of the detector 7 and fixed onto the face 11b in the slot 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an optical information reproducing pickup for optically reading information written on an optical disk. The present invention relates to an optical information reproducing pickup and an assembly method thereof, which are configured so that optical axis deviation does not occur on a mounting surface perpendicular to the optical axis when fixing with the screws after alignment adjustment.

[Background of the invention]

In a conventional pickup for optical information reproduction, for example, as described in Japanese Utility Model Application Publication No. 59-157228, an optical element is fastened to the mounting surface of an optical bench via three mounts with screws. A method has been proposed in which the optical axis of the element is aligned on the mounting surface of the optical bench that is perpendicular to the optical axis.

As a method for aligning the optical axis of the optical information reproducing pickup configured as described above, (a) the optical axis alignment is adjusted after tightening with screws. (b) After temporarily tightening the screws and aligning the optical axis, secure with the screws. Two methods are possible.

However, in the former adjustment method, the optical axis alignment position is adjusted after the screws are tightened, so a large force is required when adjusting the 0 position, so a highly rigid adjustment jig is required, and a large force is applied when adjusting the position. However, the optical element moves a large amount, making it difficult to perform fine adjustment and feeding with high precision. In addition, in the latter adjustment method, the optical axis alignment position is adjusted while the screws are temporarily tightened, so the position can be easily adjusted with a small amount of force. Since displacement occurs, it has drawbacks such as difficulty in highly accurate positioning.

Therefore, as a structure that facilitates the adjustment of the optical axis alignment position and prevents the optical axis from shifting when tightening the screws after adjusting the optical axis alignment position, for example, the structure described in Japanese Patent Application Laid-Open No. 1983-3111942 has been proposed. .

This configuration is as shown in FIGS. 7 to 12.

That is, FIG. 7 is an exploded perspective view showing a conventional optical information reproducing pickup, FIG. 8 is an enlarged exploded perspective view of the detector mounting portion shown in FIG. 7, and FIG. 9 is an exploded perspective view of the detector mounting portion shown in FIG. A front view, FIG. 10 is a cross-sectional view showing the screw fastening part during temporary tightening, FIG. 11 is a cross-sectional view showing the screw fastening part during fixation, and FIG. 12 is a detector mounting part of a conventional optical information reproducing pickup. FIG. 7 is an enlarged exploded perspective view showing another example.

First, as shown in FIG. 7, conventional optical information reproducing pickups include a semiconductor laser 2, a detector 7, and intermediate optical systems 3, 4, 6, . Objective lens actuator 5 with objective lens 51 inside
and a case 1a in which these are mounted, the laser beam emitted from the semiconductor laser 2 is made to enter the objective lens 51 via the intermediate optical systems 3 and 4, and is irradiated onto the recording surface 81 of the rotating optical disk 8. Thereafter, the reflected light from the optical disk 8 is passed through an objective lens 51. The trace state of the focal state information track (not shown) on the recording surface 81 of the optical disc 8 and the presence or absence of the bit 82 are determined by the laser light that enters the detector through the intermediate optical systems 4 and 6 and enters the detector 7. Based on these signals, a servo system (not shown) is used to control the laser beam so that it always remains focused on the recording surface 81 of the optical disk 8 and traces the information track. The one configured as follows is used.

Next, the detector mounting portion in the optical information reproducing pickup is constructed as shown in FIGS. 8 and 9.

That is, in FIGS. 8 and 9, 1a is a case, and a laser beam hole 14a is bored through the center of the board mounting surface 11a with an optical axis n-n. When connecting at the center position and fixing a board 71a (described later) to the mounting surface 11a, an escape groove 12a is formed to a size that prevents the detector 7 from hitting the mounting surface 11a. Relief grooves 13 for the four pawls 91 formed at each of the four corners of the substrate 71a are provided, and screw holes for two set screws 101a are provided at the center positions on both sides of the detector escape groove 12a. 15a is bored. A substrate 71a is formed into a rectangular plate, and the detector 7 with the optical axis n'-n' is fixed to the center position of the lower surface with solder or the like, and two holes 72a are provided on both sides of the substrate into which the set screws 101a are loosely fitted. is installed. Reference numeral 9a is a plate spring having a width smaller than that of the substrate 71a and a length approximately equal to the length of the substrate 71a, and two holes 93a for the set screws 101a are bored therein. , four L-shaped claws 91 fixed at the four corners (both ends of both end faces in the width direction).
and two claws 92 bent downward at right angles at the center of both end faces in the length direction.

Note that when the leaf spring 9a is tightened with the set screw 101a,
As shown in FIGS. 10 and 11, the tips of the two claws 92 are formed so as to bite into the board mounting surface 11a of the case 1a, and the tips of the four claws 91 are formed so as to bite into the top surface of the board 71a. It is formed to fit in.

Next, the optical axis alignment of the substrate 71a and the substrate 71a are performed. When fixing the la leaf spring 9a, first, the board 71a on which the detector 7 is mounted is attached to the set screw 101a via the leaf spring 9a.
Temporarily tighten. In this state, the two claws 92 of the leaf spring 9a
The position of the plate spring 9a is set by biting into the mounting surface 11a of the case 1.

Thereafter, the substrate 71a is moved against the mounting surface 11a of the case 1a with a force of 2 kg to align the optical axis n'-n' of the detector 7 with the optical axis n-n on the case 1a.

At this time, the signal of the optical axis deviation of both optical axes n-n and n'-n' is detected by the output signal generated by the positional deviation of the laser beam irradiated to the detictaph. The position of the detector 7 may be measured by another means, and the optical axis of the detector 7 may be aligned with the optical axis of the detector .

When the optical axis alignment of the dictaph is completed, the set screw 101a
The board 71a is fixed onto the mounting surface 11a of the case 1a with a force of 2 kg via the leaf spring 9a. At that time, board 7
In order to prevent 1a from shifting, the tips of the two claws 92 are bitten into the mounting surface 11a of the case 1a, and the tip surfaces of the four claws 91 are bitted into the top surface of the board 71a. .

However, when the set screw 101a is temporarily tightened, as shown in FIG.
The length to 1a is Q+, and the tips of the two claws 92 are biting into the mounting surface 11a of the case 1a by the difference (d-R+), but by further tightening the set screw 101a, the board 71
When a is fixed to the mounting surface 11a of the case 1a, the length from the top surface of the leaf spring 9a to the mounting surface 11a of the case 1a is 122 as shown in FIG. 11 (Ql-Q2).
only changes. Due to the structure of the two claws 92, the variation in length from the top surface of the leaf spring 9a to the mounting surface 11 of the case 1a is proportional to the length d of the two claws 92. This is due to the fact that the plate spring 9a is bent and the substrate 71a is displaced by a maximum of 2 μm.

Next, FIG. 12 shows another conventional example. In FIG. 8, the detector 7 is mounted on the case 1 of the substrate 71a.
On the other hand, in FIG. 8, the detector 7 is fixed on the side opposite to the case 1a of the substrate 71a. Therefore, in FIG. 12, a detector relief groove 12a is provided on the mounting surface 11a of the case 1a, but in FIG.
Since there is no need to provide the case 1a, the shape of the case 1a is simplified.

However, a recess 94a is provided to prevent the detector 7 from interfering with the plate spring 9a. Also in this case, as in the case shown in FIG. 8, the set screw 101a is tightened and the board 71a is
When the board 71a is fixed to the mounting surface 11a of the case 1a, the position of the board 71a is shifted by about 2 μm at the maximum due to the fall of the claw 92.

Therefore, in recent years, as optical systems have become smaller, the optical axis alignment requirement between the optical axis of the case and the optical axis of the detector on the mounting surface of the detector has become stricter to 1 to 3 μm. This is becoming difficult to achieve with conventional configurations.

For example, when using the conventional configuration described above and temporarily tightening the board with a set screw and aligning the optical axis of the detector with the optical axis of the case via the board, the board is held by the holder so that it does not move. However, in this state, it is conceivable to fix the board to the mounting surface of the case using a set screw via a leaf spring.

However, in order to hold the substrate with the holder so that it does not move as described above, the holder must have extremely high rigidity, which inevitably results in an expensive holder. In addition, it is impossible to install the above-mentioned holder on the mounting surface of the case which has become smaller, and it is impossible to install the above-mentioned holder on the mounting surface of the case, so the board and leaf spring etc. must be made even smaller. It is difficult to realize this because it requires high rigidity and high rigidity.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical information reproducing pickup that eliminates the above-mentioned conventional drawbacks, enables highly accurate optical axis alignment and fixing, and is compatible with automatic adjustment, and a method for assembling the same.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention forms a concave groove on the top surface of the case, which consists of a pair of mutually parallel side wall surfaces and a board mounting surface perpendicular to the both side wall surfaces. A plate spring is configured such that both end surfaces are fixed in opposition to each other, a board is loosely fitted into the concave groove so as to be movable, and the extracted spring is firmly fitted onto the board so as to be fixed. Temporarily tighten the board to the board mounting surface in the groove with screws through the screws.

After positioning the board in a predetermined position, fix the board to the board mounting surface in the concave groove with screws via the leaf spring.

As a result, the plate spring is fixed in a direction parallel to the board mounting surface in the concave groove, and the board is fixed to the board mounting surface in the concave groove with the screws without shifting the position.

[Embodiments of the invention]

Hereinafter, drawings showing embodiments of the present invention will be described.

FIG. 1 is an exploded perspective view of a detector mounting portion of an optical information reproducing pickup showing an embodiment of the present invention, and FIG. 2 is a perspective view of the detector mounting portion shown in FIG. 1 when assembled.

In the same figure, 1b is a case, and its upper surface lb' includes a board mounting surface 11b that is perpendicular to the optical axis n-n of the laser beam transmitted through the hole 14b, and a board mounting surface 11b that is parallel to the optical axis n-n at both ends thereof. A concave groove 17a with a height hl is formed with both side wall surfaces 16a having a width al, and a detector relief groove 12b is bored in the center of the board mounting surface 11b within this concave groove 17a. Screw holes 15b into which the tips of two set screws 101b are screwed are formed on both sides of the detector relief groove 12b.

71b is a substrate, and the width az is the width a of the concave groove 17a.
1, and the height h2 is the height hl of the concave groove 17a.
They are each formed slightly smaller, and the optical axis is located at the center of the bottom surface.
, / detector 7 is fixed with solder or the like, and two holes 72b are bored on both sides thereof into which the set screws 101b are loosely fitted. Reference numeral 9b is a plate spring, and has a width a such that both end surfaces 94 in the width direction are in contact with both side wall surfaces 16a of the concave groove 17a.
3 is slightly larger than the width al of the concave groove 17a, and the height h3
are formed to be smaller than the height hl of the substrate 7b, and have two holes 93b for the set screws 101b. Note that the height h3 of the leaf spring 9b is the height hl of the board 71b.
The reason for making it smaller is that after temporarily tightening the board 71b via the plate spring 9b with the set screw 101b, the portion of the board 71b that protrudes from the plate spring 9b is held by a position adjustment jig (not shown). .

An example of the detector mounting portion according to the present invention has the above-mentioned configuration. Therefore, when aligning the optical axis of the substrate 71b and fixing the substrate 71b, first insert the detector 7 into the detector escape groove 12b so that the substrate 71b is loosely fitted into the concave groove 17, and the leaf spring 9b is firmly fitted thereon so as to be press-fitted into the concave groove 17, and the two setscrews 101b are inserted into the hole 9.
3b and 72b and is tightened into the screw hole 15b to temporarily tighten the board 71b via the leaf spring 9b. At this time, the plate spring 9b has both end faces 94 in its width direction opposed to both side wall surfaces 16 of the concave groove 17, and its position is restrained, and the board 71b is temporarily tightened to the set screw 101b via the plate spring 9b. The substrate 71b can be moved on the substrate mounting surface 11b within the concave groove 17 to easily adjust its position. This board 7
1b is adjusted by applying a force of 2 kg to the substrate 71b, moving it onto the substrate mounting surface ttb in the concave groove I7, and moving the optical axis /-n/ of the detector 7 held there to the case 1.
The optical axis is aligned with respect to the optical axis nn of b.

When the optical axis alignment of the optical axis n'-n' of the dictaph is completed via the substrate 71b, the set screw 101b is further tightened with a torque of 2 kg-f-■ to make the substrate 71b into a concave shape via the plate spring 9b. It is fixed on the board mounting surface 11b within the groove 17a. At this time, as described above, the plate spring 9b has both end surfaces 94 in the width direction in contact with the both side wall surfaces 16a of the concave groove 17, and only moves toward the board mounting surface 11b while the plate spring 9b is attached to the board. It does not move in a direction parallel to the surface 11b. In addition, the plate spring 9b has a claw 9 as in the conventional case.
1.92, the entire lower surface of the leaf spring 9b, especially the mounting portion of the set screw 101b, directly contacts the board 71b and presses the board 71b in the direction of the board mounting surface 11b.

Therefore, with the optical axis n'-n' of the detector 7 first adjusted in position, the substrate 71b can be pressed in the optical axis direction and fixed onto the substrate mounting surface 11b within the concave groove 17.

Next, FIGS. 3 and 4 showing another embodiment of the present invention will be described. FIG. 3 is an exploded perspective view of a detector mounting portion showing another embodiment of the present invention, and FIG. 4 is a perspective view of the detector mounting portion shown in FIG. 3 when assembled. This embodiment is different from the first embodiment except for the structure of the leaf spring, and the rest is the same, so the parts other than the leaf spring are designated by the same reference numerals as in FIGS. 1 and 2.

As shown in the figure, the leaf spring 9C has four arc-shaped parts 9 at its center, leaving both upper and lower ends 95a on both end faces in the width direction.
5b.

Therefore, when the leaf spring 9c is tightly fitted into the concave groove 17a,
The four upper and lower end portions 95 form both side wall surfaces 16 within the concave groove 17a.
Since the plate spring 9b is in contact with the groove 17a in such a manner that it projects outward, both end surfaces 94 in the width direction of the leaf spring 9b are flat as in the first embodiment, and both side wall surfaces within the concave groove 17a are flat. 16a, when retightening with the set screw 101b, there is a risk that both widthwise end surfaces 94 of the leaf spring 9b may slip on both side walls 16a in the concave groove 17, causing positional deviation. can be prevented from occurring.

In this embodiment, an arc-shaped recess 95b is formed in the center of both widthwise end faces 95 of the leaf spring 9c, but the present invention is not limited to this. For example, a rectangular recess may be formed. A similar effect can be expected even if it is formed.

Next, a description will be given of FIGS. 5 and 6 showing still another embodiment of the present invention. FIG. 5 is an exploded perspective view of a detector mounting portion showing still another embodiment of the present invention, and FIG. 6 is a perspective view of the detector mounting portion shown in FIG. 5 when assembled. In this example, compared to the second example, the detector is installed at the center of the upper surface of the board. This embodiment is different from the second embodiment in that it is provided on the spring, and other than that, it is the same as the second embodiment, and therefore the same reference numerals as in FIGS. 3 and 4 are used for the other parts.

In the figure, the IC is a case, and a concave groove 17c having the same shape as the concave groove 17a shown in FIGS. The IC has screw holes 15b into which the tips of two setscrews 101b are screwed. Reference numeral 71b denotes a substrate whose shape and dimensions are the same as those in FIGS. 3 and 4, except that the detector 7 is fixed at the center of its upper surface. 9C is a leaf spring,
A recess 96 large enough to insert the detector 7 is formed in the center of the lower surface, and two holes 93b into which the set screws 101b are loosely fitted are bored on both sides of the recess 96.

Therefore, in this embodiment as well, effects similar to those of the above-mentioned embodiments can be expected.

〔Effect of the invention〕

As described above, the present invention provides a plate in which both end surfaces in the width direction are fixed in opposition to each other in a concave groove formed by a pair of parallel side wall surfaces on the upper surface of the case and a board mounting surface perpendicular to the both side wall surfaces. A spring is firmly fitted, and a set screw attached to the leaf spring is used to fix the board on which the detector is mounted, which is inserted between the board mounting surface and the leaf spring, to the board mounting surface via the leaf spring. Therefore, it is possible to temporarily tighten the board via the leaf spring using the above set screw and fix it to the board mounting surface through the board with the optical axis of the detector aligned with the optical axis of the case. When fixing, optical axis misalignment can be prevented.

In addition, since the board is fixed to the board mounting surface via a leaf spring, the board is directly pressed and fixed to the board mounting surface by the leaf spring, so a claw is installed on the conventional leaf spring and the board is pressed through this claw. The configuration is simpler and the board can be reliably fixed to the board mounting surface compared to the case where the board is pressed against the mounting surface of the case.

Furthermore, there is no need to fix the board via a leaf spring with a set screw while holding the board with a jig used for position adjustment as in the past, so the overall configuration can be made smaller and at the same time highly rigid. be able to solve problems.

Therefore, the optical axis of the detector can be aligned with the optical axis of the case with high precision, the substrate can be reliably fixed to the case, and automatic adjustment can be supported.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a detector mounting portion of an optical information reproducing pickup showing an embodiment of the present invention, FIG. 2 is an assembled perspective view of the detector mounting portion shown in FIG. 1, and FIG. 3 4 is an exploded perspective view of a detector mounting portion showing another embodiment of the present invention, FIG. 3 is a perspective view of the detector mounting portion when assembled, and FIG. 5 is a still another embodiment of the present invention. FIG. 6 is an exploded perspective view of a detector mounting section showing an example; FIG. 6 is an assembled perspective view of the detector mounting section shown in FIG. 5; FIG. Figure 8 is an enlarged exploded perspective view of the detector mounting part shown in Figure 7;
The figure is a front view of the detector mounting part shown in Fig. 8, Fig. 10 is a sectional view showing the screw fastening part during temporary tightening, Fig. 11 is a sectional view showing the screw fastening part during fixation, and Fig. 12 is a conventional FIG. 7 is an enlarged exploded perspective view showing another example of the detector mounting portion of FIG. la, lb...Case, 2...Semiconductor laser, 3,
4゜6... Intermediate optical system, 5... Lens actuator, 7... Detector, 8... Optical disk, 9a,
9b, 9c...plate spring, lla, llb...board mounting surface, 12a...detector relief groove, 13...
・Escape groove, 14a, 14b...hole for laser beam, 15a
, 15b, 93a, 93b =-hole for set screw, 16...both side wall surfaces, 17...concave groove, 91.
92...Claw, 94...Both end faces in the width direction, 95a, 95
b... recess, 96... recess, 101 a, 10
1b - Set screw. Representative Patent Attorney Tadashi Akimoto Younger brother l Fig. 27 /ku /θlb No. 3FgJ No. 4-Fig.

Claims (1)

[Claims] 1. In an optical information reproducing pickup in which a board on which a detector is mounted is fastened to a case with a set screw via a plate spring, a pair of side wall surfaces parallel to each other are provided on the upper surface of the case. , an optical information reproducing device characterized in that a concave groove consisting of a board mounting surface orthogonal to the both side wall surfaces is provided, and a leaf spring is configured such that both end surfaces are fixed to the both side wall surfaces in the concave groove in opposition to each other. pickup. 2. The board mounting surface in the concave groove is located below the top surface of the case, and a leaf spring is firmly fitted to the board mounting surface in the concave groove via the board so as to be fixed in the concave groove. 2. The optical information reproducing pickup according to claim 1, wherein the leaf spring is located below the top surface of the case. 3. The optical information reproducing pickup according to claim 1, wherein both end surfaces of the leaf spring that are in contact with both side wall surfaces of the concave groove have an arcuate recessed portion in the center thereof. 4. In the method of assembling an optical information reproducing pickup in which a board with a detector mounted on the case is fixed with screws via a plate spring, the board is attached to the bottom surface of the concave groove formed on the board mounting surface of the case. A plate spring was firmly fitted onto this board so as to be movable and fixed in the groove, and the board was temporarily tightened to the bottom surface of the groove with a screw via this plate spring to position the board at a predetermined position. A method for assembling an optical information reproducing pickup characterized in that the board is then fixed to the bottom surface of the groove with screws via a leaf spring.