JPH01194141A - Optical pickup device - Google Patents

Abstract

PURPOSE:To stably hold a converging lens in a circular hole by sticking it fast to the inside surface of the circular hole by an energizing means to press two ridges between the plane part and the curved part of the side surface of the converging lens. CONSTITUTION:The plane part is provided for the side surface of a lens tube 3 and the side surface of the lens tube facing to it is held by a plate spring 10. Consequently, at the time of an adjustment, the two ridges between the plane part and the curved part of the side surface of the converging lens are always stuck fast to the inside surface of the circular hole of a lens tube holder 5 and a converging lens optical axis 5 does not move when sliding it. Thus, it becomes unnecessary to repeat the adjustment of the position of a laser diode after adjusting the converging lens and a converging lens holding state is stably maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pickup for an optical information reproducing device.

2. Description of the Related Art In recent years, optical information reproducing devices, external storage devices for computers, digital audio discs, and other consumer products have been widely used.

However, the optical pickup device, which is one of the device components, is composed of multiple optical components and a laser diode, and the optical axes of the optical components must be precisely aligned, making assembly and adjustment difficult. .

Particularly difficult is the assembly and adjustment of a condenser lens, which converts laser light emitted from a laser diode point source into parallel light with a certain spread.

The present invention relates to improvements in optical information reproducing pickups, and provides an optical information reproducing pickup device that allows easy assembly and adjustment of the condensing lens.

First, an example of a conventional structure will be described below.

FIG. 3 is an exploded view of a condensing lens section of a conventional optical information reproducing pickup, and FIG. 4 is a partial sectional view of the condensing lens section. In FIGS. 3 and 4, 1 is a laser diode, 2 is a condenser lens that converts the laser beam emitted from the laser diode into parallel light, and 3
is the lens barrel, 4 is the optical axis of the condenser lens, and 6 is the lens barrel 3.
6 is a jig for adjusting the condenser lens, 7 is a jig hole into which jig e is inserted, and 8 is an adhesive for fixing the lens barrel 3. Adhesive hole to apply,
Numeral 9 is a screw for screwing the laser diode 1 to the lens barrel holder 6.

In the above configuration, assembly and adjustment will be explained below.

First, the lens barrel 3 is inserted into the circular hole of the lens barrel holder 6, and the jig e is inserted through the jig hole 7 and inserted into the U groove of the lens barrel 3. Next, the positioning U of the laser diode 1 is adjusted on the contact surface with the lens barrel holder 6 so that the light emitting point of the laser diode 10 is located on the optical axis 4 of the condenser lens. The laser diode 1 is fastened to the screw 5 with a screw 9. Thereafter, by moving the jig 6 so that the light emitted from the condenser lens 2 becomes parallel light, the lens barrel 3 is moved in the direction of the condenser lens optical axis 4 inside the circular hole of the lens barrel holder 5. Slide it to . Then, adhesive is applied through the adhesive hole 8 at a position where the light is parallelized, and the jig 6 is removed after waiting for the adhesive to harden.

However, in the above configuration, when the lens barrel 3 is inserted, the lens barrel holder 6 becomes circular, so the position adjustment of the laser diode 1 must be repeated, and the laser diode 1 It was necessary to adjust the condenser lens 2 and the condenser lens 2 at the same time.

Furthermore, since a cylindrical object is held inside the circular hole, the holding state is very unstable, and the condenser lens 2 moves with the slightest impact. Therefore, it was impossible to remove the jig until the adhesive was completely cured.

As described above, there was a problem in that the assembly workability was poor and a large number of adjustment steps were required.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an optical pickup device that can improve the workability of assembling and adjusting a condenser lens and significantly reduce the number of man-hours.

Means for Solving the Problems In order to solve the above problems, the optical pickup device of the present invention has a flat part parallel to the lens optical axis and having a constant width on a part of the circumference of the cylindrical side of the lens barrel at both ends of the cylinder. The lens barrel holder is inserted into a lens barrel holder having a circular hole formed over the entire surface and having a diameter larger than the outer diameter of the lens barrel, and the flat side is pushed in one direction within the circular hole of the lens barrel holder using a biasing means. It is designed to be pressed.

According to the present invention, with the above-described configuration, the two ridge lines of the flat part and the curved part of the side surface of the condenser lens are brought into close contact with the inner surface of the circular hole by the pressing means, so that the ridges inside the circular hole are brought into close contact with the inner surface of the circular hole. It becomes possible to stably hold the condenser lens.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows an exploded view of an optical information reproducing pickup optical lens section according to an embodiment of the present invention. FIG. 2 shows a partial sectional view. 1st
2, 1 is a laser diode, 2 is a condenser lens, 3 is a lens barrel with a flat part provided on a part of the cylindrical side surface, 4 is an optical axis of the condenser lens, and 5 is a lens barrel 3. A lens barrel holder held in a circular hole, 6 a jig for adjusting the condensing lens, 7 a jig hole for inserting the jig 6, 8 applying adhesive to fix the lens barrel 3 9 is a screw for screwing the laser diode 1 to the lens barrel holder 5; 1o is a plate spring for holding down the lens barrel 3; 11 is a screw for fastening the plate spring 1o to the lens barrel holder 5; 12 is a spring hole into which a leaf spring is inserted.

In the above configuration, first, the lens barrel holder 6
The lens barrel 3 is inserted so that the flat part faces the spring hole, and the plate spring 10 is fixed to the lens barrel holder 5 with screws 11. Next, the laser diode 1 is adjusted so that the light emitting point of the laser diode 1 coincides with the optical axis 4 of the condensing lens, and the laser diode 1 is fixed to the lens barrel holder 5 with screws 9. Then, insert the jig 6 into the jig hole 7.
and insert it into the U groove of the lens barrel 3. After that, the jig 6 is set so that the light emitted from the condenser lens 2 becomes parallel light.
By moving the lens barrel 3, the lens barrel 3 is slid inside the circular hole of the lens barrel holder 5 in the direction of the condenser lens optical axis 4. Furthermore, the jig 6 is removed at the position where the parallel light is generated, adhesive is applied to the adhesive hole 8, and the lens barrel holder 5 is
Fix the lens barrel 3 to.

As described above, according to this embodiment, a flat part is provided on the side surface of the lens barrel, and the opposite side surface of the lens barrel is covered with a plate spring 1.
By pressing with o, the two ridge lines of the flat part and the curved part of the side surface of the condensing lens are always in close contact with the inner surface of the circular hole of the lens barrel holder 6 during adjustment, and the lens can be slid. In some cases, it is possible to eliminate the movement of the condenser lens optical axis 6 as in the conventional case. This eliminates the need to repeatedly adjust the laser diode position after adjusting the condenser lens. Furthermore, since the condensing lens is held in a stable state even after adjustment, the jig can be removed without waiting for the adhesive to harden.

Effects of the Invention As described above, according to the present invention, a flat part parallel to the lens optical axis and having a constant width is provided on a part of the circumference of the side surface of the lens barrel.
It is inserted into a lens barrel holder that has a circular hole formed across both end surfaces of the cylinder and has a diameter larger than the lens barrel outer diameter, and is pressed so that the side surface of the flat part is pressed in one direction within the circular hole of the lens barrel holder. This makes it possible to improve the workability of condensing lens assembly and adjustment, significantly shortening the number of work steps, and suppressing fluctuations over time, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a three-dimensional exploded view of an optical pickup device according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the same embodiment,
FIG. 3 is a three-dimensional exploded view of a conventional optical pickup device, and FIG. 4 is a partial sectional view thereof. 2... Condensing lens, 3... Lens barrel, 4... Instep: Condensing lens optical axis, 6... Lens barrel holder. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure Layer - Radhe diode 2 - Condensing lens Figure 2 WJa diagram / \

Claims (1)

[Claims] a lens barrel fixed inside a short cylinder so that the optical axis of the condensing lens coincides with the center line of the cylinder, and having a flat portion parallel to the optical axis of the condensing lens with a constant width on a side surface over both end faces; A lens barrel holder having a circular hole having a diameter larger than the cylindrical outer diameter of the lens barrel, and a biasing means for pressing the flat side of the lens barrel in one direction within the circular hole of the lens barrel holder. An optical pickup device comprising: