JPH0651179A - Correction adjusting mechanism for lens optical system - Google Patents

Abstract

PURPOSE:To correct the curvature of field by positioning an adjusting member in an optional bearing by rotating a rotating member and correcting the inclination of a lens optical system. CONSTITUTION:By rotating the rotating member 6, a click ball 9 is meshed with a click groove 10 at the most adjustable position and the rotating member 6 is fixed in a lens barrel 5, Then, a taper screw 8 is allowed to advance to and retreat from the rotating member 6 by tightening or loosening the screw 8. By tightening the screw 8 further after a tapered part 8A comes into contact with the leading edge part 1B of a holding member 1, the tapered part 8A exerts force in a Z direction on the holding member 1, so that the holding member 1 is inclined in an optical axis direction with a fulcrum T as center. By tightening and loosening the screw 8 while confirming resolution, the inclination of the member 1 is adjusted and the movement of the screw 8 is stopped when the curvature of field becomes the smallest.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a correction adjusting mechanism for a lens optical system.

[0002]

2. Description of the Related Art A lens optical system, particularly a zoom lens optical system, has a plurality of mutually movable optical systems. Errors will occur and, as a result, will have a significant impact on image performance. In fact, manufacturing a zoom lens without any error requires advanced technology and is not suitable for mass production, which causes a cost increase.

Therefore, in order to alleviate the severity of the manufacturing process of the zoom lens and to eliminate the influence of the processing error and the assembly error caused by the relaxation of the manufacturing process, there is a mechanism for correcting and adjusting the optical system of the zoom lens. Proposed. For example, if there is a processing error or an assembly error in the lens barrel of the lens optical system, which causes curvature of field to affect the resolution, tilt the lens optical system with the eccentric pin that holds the lens. It has been proposed to perform centering of the optical system and correct the optical axis to correct the field curvature. Further, there has also been proposed a technique in which an eccentric roller that slides in a cam groove of a zoom lens is rotated to move the optical system in the optical axis direction and adjust the separation distance of the optical system to perform image point correction.

[0004]

However, in the conventional correction adjusting mechanism of the optical system of the zoom lens, since the field curvature is corrected by the eccentric pin holding the lens, fine adjustment is difficult and When correcting the optical axis by inclining the optical system with respect to the optical axis, the optical axis can be corrected only in one direction. No correction could be made.

[0005]

In order to solve the above problems, the present invention holds a lens barrel and a lens optical system, and a lens holder loosely fitted inside the lens barrel. A barrel, a rotating member outside the lens barrel and rotatably provided at a position adjacent to the lens holding barrel, and an end surface of the rotating member, which engages with the lens holding barrel to form a lens holding barrel. On the other hand, the adjusting member movably configured to exert a force in the direction orthogonal to the optical axis of the lens. The adjusting member is a screw member that is provided on the end surface of the rotating member and has a tapered portion on the head that can engage with the lens holding cylinder, and is an eccentric member that is held on a shaft that is orthogonal to the end surface of the rotating member. is there. Further, the adjusting member is provided on the end surface of the rotating member so as to be movable back and forth in a direction parallel to the lens optical axis, and is integrated with a focus adjusting member that engages with the lens holding barrel and moves the lens holding barrel in the lens optical axis direction. It is provided in.

[0006]

With the above construction, the adjustment member is positioned in an arbitrary direction by the rotation of the rotary member, and the inclination of the lens optical system is corrected.

[0007]

EXAMPLE Example 1 is a fixed optical system L1, L2, L3.
The present invention is applied to a zoom lens having movable optical systems L4 and L5. The zoom lens is installed inside the projection device like the projection lens of the micro reader printer.

In such a zoom lens, the optical systems L1, L2 and L3 are fixed to the holding member 1 by pressing washers 2 and 3. Similarly, the optical systems L4 and L5 are also fixed to the holding member 4 by pressing washers (not shown). The holding member 1 is provided so as to be loosely fitted inside the lens barrel 5 of the zoom lens, and can be slightly tilted with respect to the lens barrel 5. On the other hand, the holding member 4
The lens barrel 5 is movably provided in the optical axis direction by a mechanism (not shown).

A rotating member 6 is rotatably provided outside the lens barrel 5. On the other hand, on the outer periphery of the lens barrel 5 into which the rotating member 6 is fitted, a position where the outer periphery is divided into eight equal parts (A in FIG.
8 to H), eight click grooves 10 are formed in the optical axis direction. The click groove 10 has a hole 6a in the rotary member 6.
The click ball 9 inserted in the
The click ball 9 is biased by a leaf spring (not shown). Therefore, the rotary member 6 is configured to be locked at eight equal positions.

In FIG. 1a, an image point correcting screw 7 (hereinafter referred to as screw 7) is provided on the right side cross-section portion 6A of the rotating member 6.
The left cross-section portion 6B is fitted with a taper screw 8 (hereinafter, referred to as a taper screw 8) for correcting the field curvature, which has a taper head.

A groove 1A is formed in the outer periphery of the holding member 1, and a head portion 7A of a screw 7 is fitted in the groove 1A. The screw portion 7B of the screw 7 is fitted in the screw hole of the rotating member 6, and the screw 7 is tightened or loosened to move the screw portion 7B into or out of the rotating member 6, thereby making the screw 7
The head portion 7A is configured to move the holding member 1 in the optical axis direction via the groove 1A. With the above configuration, the holding member 1 is moved in the optical axis direction so that the separation distance between the optical systems L1, L2, L3 fixed to the holding member 1 and the optical systems L4, L5 fixed to the holding member 4 is increased. Changes can be made to make image point correction adjustments.

Since the head portion 8A of the taper screw 8 fitted in the rotating member 6 has a taper shape, when the taper screw 8 is tightened, the taper portion 8A comes into contact with the tip portion 1B of the holding member 1. The holding member 1 is configured to exert a force in the Z direction. Since the holding member 1 is provided in a state of being loosely fitted to the lens barrel 5, the Z
Due to the force in the direction, it is tilted in the downward right direction in the drawing with T as a fulcrum. On the other hand, when the taper screw 8 is loosened, the force exerted by the taper portion 8A on the holding member 1 becomes small and the tilt angle becomes small. When the tapered portion 8A is disengaged from the holding member 1, the holding member 1 is not affected.

Next, the operation during the correction adjustment of the optical system will be described.

When adjusting the image point correction, when the screw 7 is tightened or loosened and the screw 7 is put in or taken out from the rotating portion 6, the head 7A of the screw 7 causes the holding member 1 to light through the groove 1A. Move in the axial direction. By this, the separation distance between the holding member 1 and the holding member 4 is adjusted, the movement of the screw 7 is stopped when the image points match, and the screw 7 is fixed by an adhesive or the like. With the above, the image point correction is completed.

On the other hand, in the case of adjusting the field curvature correction, first,
Rotate the rotating member 6 to the position where adjustment is most effective (Fig. 1b).
(A to H), the click ball 9 is engaged with the click groove 10, the rotary member 6 is fixed to the lens barrel 5, and then the taper screw 8 is tightened or loosened to move the taper screw 8 forward and backward with respect to the rotary member 6. Let When the taper portion 8A contacts the tip portion 1B of the holding member 1 and the taper screw 8 is further tightened, the taper portion 8A applies a force in the Z direction to the holding member 1, so that the holding member 1 is centered on the fulcrum T. Is inclined with respect to the optical axis direction. Taper screw 8 while checking the resolution
Tighten or loosen to adjust the inclination angle of the holding member 1 and stop the movement of the taper screw 8 when the field curvature is minimized. As described above, the field curvature can be adjusted from any azimuth.

Next, a second embodiment will be described.

In this embodiment, the optical system L1 of the zoom lens is used.
-L5, the holding member 1, the holding member 4, the lens barrel 5 and the like have the same configurations as in the first embodiment, but as shown in FIG.
The taper screw 8 for correcting the field curvature is removed from the above, and the image point correcting screw 7 is additionally provided with the field curvature correcting function. Hereinafter, the screw 70 of the second embodiment shown in FIG. 3 will be described.

As shown in FIG. 3a, the screw 70 is composed of three members, that is, a screw member 71, an eccentric member 72, and a fixing screw 73. The screw member 71 has a screw portion 71A.
A mounting portion 71B and a shaft portion 71C are formed. Shaft 7
1C has a fixing screw 7 coaxially with the central axis of the screw portion 71A.
Three screw holes 71D (hereinafter referred to as screw holes 71D) are provided. On the other hand, the eccentric member 72 is formed with an elongated hole 72A having an eccentric amount only on one half side from the center. The shaft portion 71C is inserted into the elongated hole 72A, and the fixing screw 73 is tightened into the screw hole 71D. The eccentric member 72 is fixed to the screw member 71. The eccentric member 72 is assembled so as to engage with the groove 1A of the holding member 1.

The image point correction adjustment using the screw 70 will be described. First, the shaft portion 71C is inserted into the elongated hole 72A, and the outer periphery of the shaft portion 71C and the non-eccentric portion of the elongated hole 72A are brought into contact with each other. As it is, fix the fixing screw 73 into the screw hole 71
The screw member 71 and the eccentric member 72 are fixed by tightening to D, and the screw 70 is formed (state of FIG. 3b). Then, by rotating the eccentric member 72 of the screw 70 to tighten or loosen the screw 70 to move it back and forth with respect to the rotating member 6, the eccentric member 72 of the screw 70 is moved as in the first embodiment.
The holding member 1 engaged with is moved in the optical axis direction to adjust the separation distance between the holding member 1 and the holding member 4 to perform image point correction.

When correcting the field curvature, the eccentric member 72 is rotated with the fixing screw 73 loosened and the eccentric portion of the elongated hole 72A abutting the shaft portion 71C. Then, the eccentric member 72 becomes eccentric with respect to the screw member 71, so that the holding member 1 tilts in the Z ′ direction around the fulcrum T ′. Rotate the eccentric member 72 while checking the resolution,
The fixing screw 73 is fixed when the curvature of field becomes minimum.

It is to be noted that, as in the first embodiment, after the rotary member 6 is rotated and fixed in the click groove 10 at the most effective position (A to H in FIG. 2A), the field curvature is corrected. is there.

The elongated hole 72A of the eccentric member 72 of the screw 70 of the second embodiment has an eccentric amount, and is configured to perform the image point correction and the field curvature correction.
c, the screw 70 'having the configuration shown in FIG. 3d will be described.

As shown in FIGS. 3c and 3d, the screw 70 '
Is formed of a screw member 71 ′, a head 72 ′, and an E ring 81. The screw member 71 'is formed of a screw portion 71A', a mounting portion 71B ', and a shaft portion 71C'. There is an eccentric amount between the central axis of the screw portion 71A ′ and the central axis of the mounting portion 71B ′, and the thread groove 71 is formed at the end of the shaft portion 71C ′.
D'is formed. On the other hand, the head 72 'has a hole 72
A'is opened, and the shaft portion 71C 'is fitted into the hole 72A' to bring the mounting portion 71B 'and the head portion 72' into contact with each other, and then to the E ring groove 80 formed in the shaft portion 71C '. The E-ring 81 is fitted to fix the screw member 71 'and the head 72'. The head 72 'is assembled so as to engage with the groove 1A as in the first embodiment.

When adjusting the image point correction using the screw 70 ', the screw groove 71D' is rotated to move the screw 7 '.
By moving 0'with respect to the rotating member 6, the holding member 1 with which the head 72 'of the screw 70' is engaged is moved in the optical axis direction, as in the first embodiment. At this time, since the screw member 71 'has an eccentric amount with respect to the head 72',
As the screw 70 'advances and retreats in the optical axis direction by the rotation of the thread groove 71D', the holding member 1 is tilted by the amount of eccentricity, and the field curvature can be adjusted at the same time.

In the first and second embodiments, only the holding member 1 is moved, but it goes without saying that the same structure can be applied to the holding member 4.

[0026]

Since the adjusting member is provided on the rotating member, when the optical system is tilted with respect to the optical axis to correct the optical axis, the optical system is tilted not only in one direction but also in any direction. It becomes possible to incline, and the field curvature can be corrected even when the field curvature has directionality.

Further, since the correction adjustment of the lens optical system is performed by the screw, the operation is simple, and the movement amount and the inclination amount of the lens optical system are determined by the pitch of the screw, so that the fine adjustment is possible.

Further, with the screw capable of simultaneously correcting the image point and adjusting the curvature of field, there is an effect that only one member is required and the cost is reduced, in addition to the above effect.

[Brief description of drawings]

FIG. 1 is a sectional view of a correction adjustment mechanism of a lens optical system according to a first embodiment.

FIG. 2 is a sectional view of a correction adjustment mechanism of a lens optical system of Example 2.

FIG. 3 is a diagram showing a configuration of a screw according to a second embodiment.

[Explanation of symbols]

 6 Rotation part 7 Image point correction screw 8 Image field curvature correction taper screw 70 Image point correction screw 70 'Image point correction screw

Claims (5)

[Claims] 1. A lens barrel, a lens holding barrel that holds a lens optical system and is loosely fitted to the inside of the lens barrel, and is rotated to a position outside the lens barrel and adjacent to the lens holding barrel. A rotatable member that is provided so that it is provided on the end surface of the rotatable member and that engages with the lens holding cylinder,
And an adjusting member configured to be movable so as to exert a force in a direction orthogonal to the lens optical axis, and the tilting of the lens optical system is corrected by positioning the adjusting member in an arbitrary direction by rotating the rotating member. A correction adjustment mechanism for the lens optical system. 2. The adjusting member is a screw member provided on the end surface of the rotating member and having a tapered portion on the head portion that can be engaged with the lens holding cylinder. Lens optical system correction adjustment mechanism. 3. The correction adjusting mechanism of the lens optical system according to claim 1, wherein the adjusting member is an eccentric member held by an axis orthogonal to the end surface of the rotating member. 4. A focus adjusting member which is provided on the end surface of the rotating member so as to be movable back and forth in a direction parallel to the lens optical axis, and which engages with the lens holding barrel to move the lens holding barrel in the lens optical axis direction. The correction adjusting mechanism of the lens optical system according to claim 1. 5. The correction adjusting mechanism for a lens optical system according to claim 4, wherein the adjusting member and the focus adjusting member are integrally provided.