JPH04291029A - Objective lens drive device - Google Patents

Abstract

PURPOSE:To reduce the tilting angle of an objective lens caused by the precision, etc., of the part as much as possible and to eliminate the adjustment of the tilt of the objective lens conventionally needed, in the objective lens driving device of an optical information recording and reproducing device. CONSTITUTION:A spring member 5 supporting an objective lens 4 is provided with a spring part 11 to be pressed against the inner circumferential part of an objective lens insertion hole and its outer diameter is smaller than an insertion hole for the spring member 5 of an objective lens driving device fixing part 6. By inserting an assembling jig pin 3 set in the vertical position with respect to a reference surface into the objective lens insertion hole of the spring member 5, fitting the other respective parts, removing the assembling jig pin 3 and at the same time, inserting the objective lens 4 into the hole of which the pin was inserted and fixing the lens, the objective lens driving device can be assembled. Thus, the number of parts required for constructing the device can be minimized and the tilt adjustment of the objective lens can be eliminated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spring shape, structure, and method for improving assembly accuracy in an objective lens drive device in an optical pickup of an optical information recording/reproducing device.

0002

[Prior Art] The conventional device is
As described in Publication No. 7, a plate spring is interposed between the objective lens drive device and the optical base, and this plate spring prevents assembly errors of the objective lens provided in the objective lens drive device. The structure was designed to adjust the angle of inclination with respect to the reference plane caused by this.

However, in this conventional device, a plate spring is interposed between the optical base and the objective lens driving device, and the inclination angle of the objective lens with respect to the reference plane is removed by the amount of deflection of the plate spring. , adjustment work is always involved in the production process, reducing product productivity. Furthermore, since the adjustment function is provided, the above-mentioned leaf spring, which is not originally required, is required, which increases the number of parts.

[0004] As described above, the conventional apparatus has the above-mentioned problems such as an increase in the number of parts and the necessity of adjustment work, which leads to a decrease in product productivity and an increase in costs.

[0005]

[Problems to be Solved by the Invention] As described above, in the prior art, a leaf spring is required to be interposed between the objective lens drive device and the optical base, which increases the number of parts. , there was a problem that adjustment work was required to remove the tilt angle of the objective lens with respect to the reference plane, and no consideration was given to the reduction in product productivity, resulting in an increase in product costs. .

An object of the present invention is to suppress the inclination angle of the objective lens with respect to a reference plane in the objective lens drive device to a level so small as to eliminate the need for adjustment, using the minimum number of parts necessary to construct the objective lens drive device. It is an object of the present invention to provide an objective lens driving device having a structure that makes it possible to eliminate adjustment work.

[0007]

[Means for Solving the Problems] The above object is to eliminate the gap existing between the objective lens insertion hole of the objective lens supporting spring member in the objective lens driving device and the objective lens outer diameter, and This is achieved by providing a structure in which the spring member can freely slide on the spring member mounting surface of the fixed portion of the objective lens driving device so that the inclination angle of the objective lens with respect to the reference plane can be eliminated during assembly. Specific means thereof are shown in FIGS. 1 and 2. In other words, when inserting and adhesively fixing each component of the objective lens drive device into an assembly jig that has a pin in the center that is perpendicular to the reference plane and whose outer diameter is approximately the same as the outer diameter of the objective lens. , the pressing spring portion provided on the inner periphery of the spring member through-hole presses the pin of the assembly jig against the opposing side of the pressing spring portion of the inner periphery of the spring member through-hole, so that the pressing spring portion of the upper and lower spring members The facing surface of the inner peripheral portion of the through hole follows the pin of the assembly jig. In this state, each part is adhesively fixed, and then the assembly jig is removed, and the objective lens is inserted into the through hole of the upper and lower spring members in which the assembly jig pin was inserted, and this is adhesively fixed. .

[0008]

[Operation] As shown in Figure 1, an assembly is installed perpendicularly to the reference plane at approximately the center of the objective lens drive device where the objective lens is to be placed, and whose outer diameter is approximately the same as that of the objective lens. By inserting each component of the objective lens drive device into an assembly jig equipped with jig pins, the assembly jig pins are inserted into the objective lens insertion holes of the spring member that connects and supports the objective lens with the objective lens fixing part. inserted. As shown in FIG. 2, the inner circumferential portion of the through hole of the spring member is provided with a pressing spring portion, and since the inner diameter of the pressing spring portion is smaller than the outer diameter of the objective lens, the pressing spring portion is The assembly jig pin inserted into the through hole is pressed against the inner circumferential surface of the through hole opposite to the pressing spring portion. At this time, since the outer diameter of the spring member is smaller than the inner diameter of the spring member insertion part of the objective lens drive device fixing part,
As described above, when the spring member through hole is positioned according to the assembly jig pin, the spring member freely moves onto the spring member mounting surface provided on the objective lens drive device fixing part and on the spacer. Can be slid on the bottom surface. By positioning the upper and lower spring members in this manner, a line connecting the centers of the through holes of the upper and lower spring members becomes parallel to the assembly jig pin, that is, perpendicular to the reference plane. In this state, each part is adhesively fixed, the assembly jig is removed, and the objective lens is inserted into the through hole of the spring member into which the assembly jig pin was inserted and is adhesively fixed. is positioned so as to follow the through hole of the spring member, which is positioned so that the straight line connecting its centers is perpendicular to the reference plane, so that it does not tilt significantly with respect to the reference plane. Therefore, there is no need to adjust the tilt of the objective lens after assembling the objective lens drive device.

[0009]

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3.
, will be explained with reference to FIGS. 4 and 5.

FIG. 1 is a cross-sectional view showing the assembly procedure of an objective lens drive device in an embodiment of the present invention, and FIG. 2 is a sectional view showing a spring member supporting an objective lens, which is pressed against the inner periphery of the objective lens insertion hole. 3 is a sectional view of an objective lens driving device according to another embodiment of the present invention, FIG. 4 is a detailed diagram of a pressing spring section provided on the outer periphery of the spring member, and FIG. FIG. 3 shows a cross-sectional view of the objective lens driving device in the embodiment.

The objective lens 4 is equipped with a bobbin 8 having an appropriate rigidity, around which a vertical driving coil is wound.
The two spring members 5 are arranged to sandwich the bobbin 8 at their inner periphery, and sandwich a spacer 7 at their outer periphery to maintain the distance between the two spring members 5.
The movable part consisting of the objective lens drive device fixed part 6
It connects and supports. A magnetic circuit composed of a magnet and a yoke is provided in the objective lens drive device fixing unit 6, and a portion of the vertical drive coil is located within the magnetic gap in this magnetic circuit, and the vertical drive coil is positioned within the magnetic gap in this magnetic circuit. By passing a drive current through the coil, electromagnetic force is generated,
The movable part is structured to be movable in the vertical direction. Further, in order to tightly fix the inner circumferential portion of the upper spring member 5a to the bobbin 8, a spring presser 9 is provided on the upper surface of the inner circumferential portion of the spring member 5a, and in order to press the outer circumferential portion against the spacer 7, the cover 10 is It is provided on the upper surface of the outer peripheral part of the member 5a. When assembling the objective lens drive device, assembly jig 2 is used.
The mounting surface of the objective lens drive device fixing part 6 is pressed against the reference surface 1 of the assembly jig, and each component is then inserted into the assembly jig pin 3. This assembly jig pin 3 is located approximately at the center of the objective lens drive device where the objective lens 4 is to be placed, and is erected perpendicularly to the reference plane 1 of the assembly jig 2. , and its outer diameter is approximately the same as the outer diameter of the objective lens 4. Further, a pressing spring portion 11 is provided on the inner circumference of the through hole for inserting the objective lens 4 in the spring member 5, and when the objective lens 4 or the assembly jig pin 3 is inserted into this through hole, the pressing spring The structure is such that the objective lens 4 or the assembly jig pin 3 is pressed against one of the inner circumferential surfaces of the through hole. On the other hand, the outer diameter of the spring member 5 is smaller than the inner diameter of the spring member 5 insertion part of the objective lens drive device fixing part 6;
The spring member 5 is a spring member 5 of the objective lens drive device fixing part 6.
It has a structure that allows it to slide freely on the mounting surface and on the upper and lower surfaces of the spacer 7.

Next, the operation will be explained. Objective lens 4
The drive current flowing through the vertical drive coil wound around the bobbin 8 interacts with the magnetic flux flowing through the magnetic gap in the magnetic circuit to generate electromagnetic force. Due to the electromagnetic force generated in this vertical drive coil, the objective lens 4 supported by two spring members 5 moves in the vertical direction.
Move to the specified position. Next, the operation of each part during assembly will be explained. Press the mounting surface of the objective lens drive device fixing part 6 against the reference surface 1 of the assembly jig 2, and place the outer diameter of the objective lens 4 perpendicular to the reference surface 1 at the position where the objective lens 4 is to be placed. By inserting each component into the assembly jig pin 3, which is almost the same, the assembly jig pin 3 is inserted into the through hole into which the objective lens 4 is to be inserted in the spring member 5 that supports the objective lens 4. . As shown in FIG. 2, a pressing spring portion 11 is provided on the inner circumference of the through hole of the spring member 5, and the inside diameter of this portion is smaller than the outer diameter of the objective lens 4 and the outer diameter of the assembly jig pin 3. Therefore, the pressing spring portion 11 presses the assembly jig pin 3 inserted into the through hole of the spring member 5 against the spring member 5 facing the spring portion 11.
Press it against the inner peripheral surface of the through hole. At this time, the outer diameter of the spring member 5 is smaller than the inner diameter of the spring member 5 insertion part in the objective lens fixing part 6, and the spring member 5 is placed on the mounting surface of the spring member 5 in the objective lens drive device fixing part 6 and on the spacer. 7 Since it has a structure that allows it to slide freely on the upper and lower surfaces, there is no problem when positioning the assembly jig pin 3 and the through hole of the spring member 5. By positioning the upper and lower spring members in this manner, the line connecting the centers of the through holes of the upper and lower spring members 5 becomes parallel to the assembly jig pin 3 erected perpendicularly to the reference plane 1. , as a result, it is perpendicular to the reference plane 1. In this state, each component is adhesively fixed, the assembly jig 2 is removed, and the objective lens 4 is inserted into the through hole of the spring member 5 into which the assembly jig pin 3 was inserted and adhesively fixed. Therefore, the objective lens 4 is positioned along the through hole of the spring member 5, which is positioned so that the straight line connecting the centers thereof is perpendicular to the reference plane 1. It does not tilt significantly, so after assembling the objective lens drive device,
There is no need to adjust the tilt of the objective lens 4.

As described above, according to this embodiment, the through holes for inserting the objective lens 4 in the upper and lower spring members 5 have a large influence on the magnitude of the inclination angle of the objective lens 4 with respect to the reference plane 1. The center position deviation of the is corrected by the assembly jig pin 3 set perpendicular to the reference plane 1, so even if the precision of each part is somewhat poor, as long as it is within the correction range, the assembly jig pin 3 , since the tilt is corrected, the objective lens driving device is not assembled with the objective lens 4 largely tilted with respect to the reference plane 1, which is necessary when the present invention is not applied as in the past. Objective lens 4
This eliminates the need for parts for the tilt adjustment mechanism, and also eliminates the need to adjust the tilt of the objective lens 4 after assembling the objective lens drive device. There is an effect that it is possible to assemble an objective lens drive device having a structure that eliminates the need for adjusting the inclination of the objective lens 4 with respect to the reference plane 1 after the objective lens drive device is assembled.

FIG. 3 shows another embodiment in which the outer peripheral shape of the spring member 5 and the structure of the assembly jig 2 are different. In this case, a surface parallel to the reference surface 1 is provided at the position where the objective lens 4 of the assembly jig 2 is to be placed, the bottom surface of the objective lens 4 is pressed against this surface, and each component is inserted, arranged, and fixed by adhesive. To go. Further, a pressing spring part 12 shown in FIG. 4 is provided on the outer periphery of either one of the upper and lower spring members 5, and the objective lens 4 of the spring member 5 provided with this pressing spring part 12 is inserted. The other spring member 5 with the center of the through hole as a reference.
Since the center of the through hole is corrected, the objective lens 4 does not tilt significantly with respect to the reference plane 1.

FIG. 5 shows another embodiment in which the pressing spring portion 12 shown in FIG. 4 is provided on the outer periphery of the upper and lower spring members 5. As shown in FIG. In this case, it is necessary to make the concentricity of the inner and outer diameters of the upper and lower spring members 5 and the perpendicularity of the inner wall of the spring member 5 insertion part of the objective lens drive device fixing part 6 with respect to the reference plane 1 highly accurate.

[0016]

[Effects of the Invention] As explained above, according to the present invention,
An assembly jig pin that is set perpendicular to the reference plane to correct the center position deviation of the objective lens insertion hole of the upper and lower spring members, which has a large influence on the size of the inclination angle of the objective lens with respect to the reference plane. Since the objective lens drive device is not assembled with the objective lens largely tilted with respect to the reference plane, the objective lens drive device can be assembled with the minimum number of parts necessary to configure the objective lens drive device. This has the effect of making it possible to assemble an objective lens drive device having a structure that eliminates the need for subsequent adjustment of the inclination of the objective lens with respect to the reference plane.

Furthermore, by partially changing the shape of the outer peripheral portion of the spring member, there is an effect that the structure of the assembly jig can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an assembly procedure of an objective lens driving device in an embodiment of the present invention.

FIG. 2 is a detailed view of a pressing spring portion provided at the inner peripheral portion of the objective lens insertion hole of the spring member that supports the objective lens.

FIG. 3 is a sectional view of an objective lens driving device in another embodiment of the present invention.

FIG. 4 is a detailed view of a pressing spring portion provided on the outer periphery of the spring member.

FIG. 5 is a sectional view of an objective lens driving device in another embodiment of the present invention.

[Explanation of symbols]

1...Reference surface 2... Assembly jig 3... Assembly jig pin 4...Objective lens 5...Spring member 6...Objective lens drive device fixing part 7...Spacer 8...Bobbin 9...Spring holder 10...Cover 11... Pressing spring part 12...Press spring part

Claims (4)

[Claims] Claim 1: An objective lens is provided on a bobbin having appropriate rigidity, the bobbin has at least one set of driving coils for movement in at least one direction, and a fixed part of an objective lens driving device and the bobbin are provided. and a movable part consisting of the objective lens, etc., connected and supported by at least two or more spring members made of an elastic material such as phosphor bronze, etc., and an objective lens drive device capable of movement in at least one direction. , the spring member has at least one protrusion or pressing spring portion on the inner periphery of the through-hole into which the objective lens or the bobbin is inserted, and the inner periphery of the through-hole of the spring member is equal to or smaller than the protrusion. Alternatively, only the pressing spring portion is smaller than the outer diameter of the objective lens or the bobbin, and the outer diameter of the spring member is smaller than the inner diameter of the spring member insertion portion provided in the fixed portion of the objective lens driving device. objective lens drive device. 2. The spring member has a protruding portion or a pressing spring portion on an outer peripheral portion thereof, and the outer peripheral diameter of the spring member is smaller than the inner diameter of the spring member insertion portion provided in the fixed portion of the objective lens driving device. The objective lens driving device according to claim 1, wherein only the protruding portion or the pressing spring portion is large. 3. A claim characterized in that the protruding portion or pressing spring portion provided on the outer peripheral portion of the spring member is present only in one of the spring members and not in the other spring members. 1. The objective lens driving device according to 1. 4. The spring member is assembled so that the protruding portions or pressing spring portions provided on the inner and outer peripheries of the through-hole portions are respectively positioned in a straight line with respect to the other spring members. The objective lens driving device according to claim 1, 2 or 3.