JPH05314494A - Lens holding apparatus - Google Patents

Abstract

PURPOSE:To easily adjust the position with high accuracy in the simple structure and to hold a lens in a stable manner. CONSTITUTION:An annular groove part 21 is formed in a holding cylinder 20 holding a condenser lens 6. A leaf spring 23 having a through hole 25 formed therein is elastically brought in touch with the holding cylinder 20, thereby to press the holding cylinder 20 against reference surfaces 22a, 22b of a pickup housing 22. When a rod-like adjusting member is inserted in the annular groove part 21 from the through hole 25 and then oscillated, the holding cylinder 20 is moved in the direction of an optical axis of the lens while the cylinder 20 is pressed to the reference surfaces 22a, 22b. Accordingly, the position of the lens is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens holding device applied to an optical pickup of an optical information recording / reproducing device.

[0002]

2. Description of the Related Art Conventionally, in an optical pickup of an optical information recording / reproducing apparatus, in order to improve recording density, information is recorded / reproduced / erased by focusing a laser beam on an extremely small spot by an objective lens. There is. For this reason, highly accurate assembling is required for each optical component, and further easy assembling is required in terms of manufacturing.

In a collimator lens position adjusting device for an optical pickup disclosed in Japanese Utility Model Publication No. 62-30177 for adjusting the position of a collimator lens of an optical pickup, the length of the through hole for accommodating the collimator lens is made shorter than that of the collimator lens. Moreover, an opening groove portion is provided on both sides of the through hole, an adjusting lever is inserted into the opening groove portion, and the position of the collimator lens is adjusted by operating the adjusting lever.

[0004]

However, in the above collimator lens position adjusting device, it is necessary to provide a through hole in the pickup housing or the like, which complicates the processing of the pickup housing or the like. Further, since the open groove portions are provided on both sides of the through hole for accommodating the collimator lens, it can be said that the shape is disadvantageous in taking measures against dust of the optical component.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lens holding device having a simple structure, capable of easily performing highly accurate position adjustment, and capable of holding a stable lens.

[0006]

In order to achieve the above object, the present invention provides a holding member for holding a lens with a locking step portion, and the holding step portion is provided with the holding member in the lens optical axis direction. An elastic member that movably presses against a reference surface is installed, and the elastic member is engaged with the locking step portion to adjust the position of the holding member in the lens optical axis direction. It is characterized in that a through hole into which a member is inserted is formed.

The adjusting member is provided with an eccentric pin, the eccentric pin and the locking step portion are engaged with each other, and the holding member is moved by rotation of the adjusting member.

Further, the invention is characterized in that a deformable sealing member having an optical path is interposed between the holding member and an optical member adjacent to the holding member.

Further, after adjusting the position of the holding member, a fixing agent is injected from a through hole of the elastic member to fix the holding member.

[0010]

According to the above means, the adjusting member is inserted from the through hole of the elastic member and is engaged with the locking step while the lens holding member is pressed against the reference surface by the elastic member. The member adjusts the position of the lens in the optical axis direction via the holding member.

Further, the holding member can be smoothly moved by engaging the eccentric pin provided on the adjusting member with the locking step portion and rotating the adjusting member, and highly accurate position adjustment can be performed.

Further, by interposing a deformable sealing member having an optical path between the holding member and the adjacent optical member, it is possible to move the holding member for position adjustment and to prevent dust and the like from entering the optical path. Prevent intrusion.

Further, after the position of the holding member is adjusted in the elastic member, it is fixed by the fixing agent inserted from the through hole of the elastic member, so that the adjusted positional accuracy is maintained in a good state.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a block diagram of an optical system of an optical pickup to which an embodiment of the present invention is applied.
Light emitted from the laser beam passes through the coupling lens 2, the beam splitter 3, and the objective lens 4 and is focused on the recording medium 5. The reflected light reflected by the recording medium 5 passes through the objective lens 4 again, is reflected by the beam splitter 3 and is converged by the condenser lens 6, and then is received by the knife edge prism 7 and the light receiving element 8 and λ / 2. It is divided in the direction of the plate 9.

Focus detection is a so-called knife edge method, in which the light reflected by the knife edge prism 7 has its polarization plane rotated by 45 ° by the λ / 2 plate 9, and then is polarized by the polarization beam splitter 10 into P-polarized light and S-polarized light. Separated into polarized light, P polarized light is transmitted through the polarized beam splitter 10 to detect the track /
It is incident on the light receiving element 11 which also serves as an information signal detector. S-polarized light is reflected by the polarization beam splitter 10, and an information signal detection light receiving element
Incident on 12. Focusing error signals, tracking error signals, and information signals are detected by the light-receiving elements 8, 11, and 12 in a known manner.

FIG. 1 is a partial front sectional view of the condenser lens 6 portion which is an embodiment of the lens holding device of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. Is
It is held in a hollow holding cylinder 20 which is a holding member. An annular groove portion 21 is formed on the outer peripheral portion of the holding cylinder 20 to serve as a locking step portion. Pickup housing of this annular groove 21 part
One end of a leaf spring 23, which is an elastic member, is fixed to 22 by a set screw 24. The other end of the leaf spring 23 is in elastic contact with the periphery of the annular groove 21 of the holding cylinder 20.

The holding cylinder 20 receives the pressing force of the leaf spring 23.
Contacts the reference surfaces 22a and 22b of the pickup housing 22 and is positioned in the direction perpendicular to the lens optical axis direction. Further, a through hole 25 is formed in a portion of the leaf spring 23 corresponding to the annular groove portion 21.

An elastically deformable sealing member (for example, sponge, rubber bellows, etc.) 26 having an optical path 26a is provided between the holding barrel 20 and the beam splitter 3 which is an optical member adjacent to the holding barrel 20. By interposing it, it prevents dust and the like from entering the optical path.

FIG. 3 is an explanatory view of the position adjustment in the above embodiment, in which the rod-shaped adjusting member 30 is inserted from the through hole 25 of the leaf spring 23, and the tip end of the adjusting member 30 and the annular groove portion of the holding cylinder 20. twenty one
Engage and. When the adjusting member 30 is swung in the optical axis direction of the lens in this state, the holding cylinder is deformed while the sealing member 26 is deformed.
20 moves in the lens optical axis direction so as to slide on the reference surfaces 22a and 22b, the position of the condenser lens 6 in the optical axis direction is adjusted, and the focus of the focused light is adjusted.

As the locking step portion, a hole may be formed instead of the annular groove portion 21. Also, the annular groove 21
It is sufficient to provide at least one hole and the number of installation is not limited.

FIG. 5 is a perspective view showing another example of the adjusting member. Although the adjusting member 30 shown in FIG. 3 is a simple rod-shaped body,
The adjusting member 35 of FIG. 5 is provided with an eccentric pin 35b at the end thereof so as to be eccentric with respect to the axial center of the rod-shaped main body 35a, and as shown in the explanatory view of FIG. 6, the through hole 25 of the leaf spring 23. To eccentric pin 35b
The adjustment member 35 is inserted so that the holding groove 20 and the annular groove portion 21 of the holding cylinder 20 are engaged with each other.

By rotating the adjusting member 35, the eccentric pin 35b can be moved to smoothly move the holding cylinder 20 in the lens optical axis direction, and highly accurate focus adjustment of the condenser lens 6 is performed. ..

After adjusting the position of the holding cylinder 20 as shown in FIGS. 3 and 6, a fixing agent (not shown) such as an adhesive is injected from the through hole 25 of the leaf spring 23. Like this
By fixing the holding cylinder 20 to the pickup housing 22, the positional accuracy of the focusing lens 6 after adjustment can be favorably maintained.

Although the above embodiment has been described by taking the holding barrel 20 of the focusing lens 6 as an example, it can be applied to a holding device for other lenses.

[0026]

As described above, according to the present invention,
The position of the holding member can be adjusted by the adjusting member inserted from the through hole of the elastic member while pressing the holding member of the lens against the reference surface by the elastic member, and the focus adjustment of the lens can be performed reliably and easily. Eccentric pin
By moving the holding member by rotating the adjusting member, high-precision focus adjustment can be performed smoothly, and a deformable sealing member is interposed between the holding member and the adjacent optical member, so that the inside of the optical path can be adjusted. Prevents intrusion of dust and the like into the elastic member, and fixes the holding member by injecting a fixing agent from the through hole of the elastic member after the adjustment, so that the positional accuracy is maintained. It is possible to provide a lens holding device that can be easily adjusted and can hold a stable lens.

[Brief description of drawings]

FIG. 1 is a partial front sectional view of an embodiment of a lens holding device of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is an explanatory diagram of position adjustment of the present embodiment.

FIG. 4 is a configuration diagram of an optical system of an optical pickup.

FIG. 5 is a perspective view showing another example of the adjusting member.

FIG. 6 is an explanatory diagram of position adjustment by the adjustment member of FIG.

[Explanation of symbols]

6 ... Condensing lens, 20 ... Holding tube (holding member), 21 ... Annular groove (locking step), 22 ... Pickup housing, 22
a, 22b ... Reference plane, 23 ... Leaf spring (elastic member), 25 ... Through hole, 26 ... Sealing member, 26a ... Optical path, 30, 35 ... Adjusting member, 35b ... Eccentric pin.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Haruhiko Kono 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Masaki Sakata 10-3 Kitamura, Tottori-shi, Tottori Ricoh Micro Electronics Co., Ltd. Within

Claims (4)

[Claims] 1. A holding member for holding a lens is provided with a locking step portion, and an elastic member for pressing the holding member to a reference surface movably in the lens optical axis direction is provided at the locking step portion. The lens is characterized in that the elastic member is provided with a through hole into which an adjusting member for engaging with the locking step portion and adjusting the position of the holding member in the lens optical axis direction is inserted. Holding device. 2. The lens holding device according to claim 1, wherein the adjusting member is provided with an eccentric pin, the eccentric pin is engaged with the locking step portion, and the holding member is moved by rotation of the adjusting member. apparatus. 3. The lens holding device according to claim 1, wherein a deformable sealing member having an optical path is interposed between the holding member and an optical member adjacent to the holding member. 4. The lens holding device according to claim 1, wherein after the position adjustment with respect to the holding member, a fixing agent is injected from a through hole of the elastic member to fix the holding member.