JP2000098208A - Lens frame structure and optically centering method for lens frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens frame structure by which the centering adjustment of a lens is easily executed and also compactification and miniaturization are realized. SOLUTION: This lens frame is constituted of a second group frame 22 and a focus frame 29 holding lenses 42a and 42b and a lens to be adjusted 42c, and the lenses 42a and 42b are held at the inside of the focus frame 29, and the lens to be adjusted 42c is inserted in a state where a second outside diameter part 42cB is exposed from the end surface of a lens holding part 29a. The lens to be adjusted 42c is stuck and fixed at the focus frame 29 by executing centering adjustment, and then, in the case that a guide shaft 30 is stuck and fixed at the focusing frame 29 the lens to be adjusted 42b is positioned at a centering jig for the second group frame 22, so that the guide shaft 30 is stuck and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens frame structure capable of optical centering adjustment and an optical centering method of the lens frame.

[0002]

2. Description of the Related Art Hitherto, as proposals for a lens frame capable of optical centering adjustment or an optical centering method thereof, Japanese Patent Application Laid-Open No. Sho 59-107307 and Japanese Utility Model Laid-Open No. Sho 59-68306 have been proposed. Gazette, Japanese Utility Model Laid-Open No. 59-121608
Gazette, Japanese Utility Model Laid-Open No. 59-161108,
-68710, JP-A-59-69708,
JP-A-60-129715, JP-A-59-159
No. 111 publication. These proposals relate to a lens barrel in which a lens whose centering is adjusted is held in a state that the lens is accommodated in the lens frame.

On the other hand, small optical devices such as cameras have been increasingly required to be more compact in recent years, and the size of the lens barrel has been inevitably reduced in order to meet the demand.

[0004]

However, in the lens frame that can be optically centered and adjusted as proposed in each of the above publications, the lens whose centering is adjusted as described above is housed inside the lens frame. Is held in a state where Therefore,
A large space obtained by adding the thickness of the lens frame to the outer diameter of the lens becomes an occupied space, which hinders miniaturization of the lens barrel. Further, when performing optical centering adjustment of the lens, since the lens is housed inside the lens frame, it is difficult to perform the lens positioning operation, and it is difficult to perform optical centering adjustment.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a lens frame structure capable of reducing the size and size of a lens frame and easily adjusting optical centering. And a method for adjusting the optical center of the lens barrel.

[0006]

According to a first aspect of the present invention, there is provided a lens frame structure comprising: a first frame; a first outer diameter portion held by the first frame; A lens having a second outer diameter portion having an outer diameter larger than the outer diameter of the frame and a second frame are provided, and the optical center of the lens is aligned with the center of the second frame.

According to a second aspect of the present invention, there is provided a method for optically centering a lens barrel, comprising: a first frame; a first outer diameter portion held by the first frame; An optical centering method for a lens barrel including a lens having a second outer diameter portion having an outer diameter larger than the outer diameter, and a second lens frame, the method comprising: Centering is performed by aligning the optical center of the lens.

According to a third aspect of the present invention, there is provided a method for optically centering a lens barrel, comprising: a first frame; a first outer diameter portion held by the first frame; An optical centering method of a lens barrel including a lens having a second outer diameter portion having an outer diameter larger than the outer diameter, and a second frame having the second outer diameter portion and the second frame. The center of the second frame is aligned with the optical center of the lens by using a jig member that is positioned by fitting to the fitting portion of the second frame.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a lens barrel 50 in which a lens barrel according to an embodiment of the present invention is incorporated, in a photographable state, in which an upper half is in a wide state and a lower half is in a tele state. Is shown. Note that the lens barrel 50 is
It is a lens barrel that can be retracted, and all the movable lens frames are moved from the state shown in FIG.

The lens barrel 50 includes a collapsible drive system for driving the collapsible position from the collapsible position to the photographing preparation position, ie, a retractable drive area, a lens group drive system for extending the lens group frame, and a lens group drive system. And a lens group frame portion for holding.

The retractable drive system is mainly fixedly supported by the camera body 51 and advances and retreats between a fixed frame 1 having a helicoid drive gear (not shown) and a drive ring 3 and a retracted position and a photographing preparation position. A rotating frame 2 that rotates between a wide position and a telephoto position at a shooting preparation position, a helicoid ring 4 that is rotatably supported by a moving frame 5 described below, and a position between the retracted position and the photographable position together with the rotating frame 2. A moving frame 5 that moves straight along the optical axis O.

The lens group drive system is mainly inserted into the moving frame 5 and driven forward and backward, rotates with the rotary frame 2 and rotates with the cam frame M11 moving forward and backward, and the cam frame M11 to rotate the second group frame 22. The cam frame M12 includes a cam frame F12 that is driven forward and backward, a key ring 13 that guides the lens group straight, and a movable flare stop 15 that is supported by the cam frame M11 and moves straight.

The above-mentioned lens group frame portion is built in the cam frame M11 and the cam frame F12, and is constituted by each lens group holding frame that moves linearly. That is, the first frame 21 that is driven forward and backward through the cam frame F12 and holds the first lens 41, and the second frame that is linearly guided through the key ring 13 and driven forward and backward by the cam frame M11. Certain second group frame 2
2, a movable follower 28 driven forward and backward through the cam frame F12, and a movable follower 28 driven forward and backward through the movable follower 28.
A first group 23 that holds the group lens 43 and a second group frame 22 that are relatively movably held by the third group frame 23 and that are driven straight forward along the optical axis O by a focusing drive system (not shown). It is a focusing frame 29 which is a frame.

FIG. 2 is a longitudinal sectional view of the focusing frame 29. The focusing frame 29 includes a plurality of lenses 42a,
42b and the lens to be adjusted 42c.
The lens 42c has a first outer diameter portion 42cA having an outer diameter D1 and a second outer diameter portion 42cB having an outer diameter D2 larger than the outer diameter D1.

The focusing frame 29 has a second group frame 2
A guide shaft 30, which is slidably supported without play, is adhesively fixed to 2. Therefore, the focus frame 29 is 2
It is supported so as to be able to move forward and backward relative to the group frame 22 along the optical axis O. The focusing frame 29
Is guided by the guide shaft 30 at the same time, and at the same time, the optical axis O is rotated by a rotation preventing member (not shown) provided on the second group frame 22.
It is assumed that the rotation around is restricted.

The outer diameter portions of the lenses 42a and 42b are fitted (precisely fitted) to the inner diameter portion of the lens holding portion 29a without play, and are directly adhered and fixed. On the other hand, the lens 42c, which is the lens to be adjusted, has a large effect on the optical performance due to the optical misalignment, and therefore the first
Of the outer diameter portion 42cA of the lens holding portion 29a with the fitting portion of the lens holding portion 29a.
In this state, the fitting is performed (free-fitting), and the second outer diameter portion 42cA is operated by a centering jig 61 (see FIG. 3), which will be described later, to be centered and adhered and fixed.

The second outer diameter portion 42cB of the lens 42c
Is larger than the outer diameter D0 of the lens holding portion 29a, and is held in a state of being exposed to the outside from the end face of the lens holding portion 29a. When the centering is adjusted, the second outer diameter portion 42cB is It can be adjusted externally.

FIG. 3 is a longitudinal sectional view showing a state where a centering jig for attaching and fixing the lens 42c to the focusing frame 29 is mounted. When performing the above-mentioned bonding, first, the focusing frame 29 in a state where the lenses 42a and 42b are fixed inside the lens holding portion 29a is attached to the centering jig 61.
At this time, the reference inner peripheral portion 29e of the focusing frame and the reference outer peripheral portion 61e of the centering jig are fitted.

With the focusing frame mounted, a lens 42c is attached to the inner diameter of the lens holding portion 29a of the focusing frame.
The first outer diameter portion 42cA is inserted (with loose fit) with the gap X1. Then, the position of the lens 42c is finely adjusted via the second outer diameter portion 42cB, and the lenses 42a, 42b and the lens 42c are optically aligned by a chart image monitor using laser light. Then, an ultraviolet curing adhesive 31 is injected into the gap X1 and bonded.

FIG. 4 is a longitudinal sectional view showing a state where a centering jig for attaching and fixing the guide shaft 30 to the focus frame 29 is mounted. When the guide shaft 30 is bonded, the second group frame 22 is aligned with the frame positioning reference inner peripheral portion 71 of the centering jig 71.
e, the positioning outer peripheral portion 22e of the second group frame 22 is fitted and attached.

Further, the second outer diameter portion 42 of the lens 42c which is already fixed to the focusing frame 29 with respect to the lens positioning reference inner peripheral portion 71b of the centering jig 71.
The focusing frame 29 is attached by fitting cB. In this mounted state, the optical centering of the lens 42c with respect to the second lens group frame 22 is performed.

Therefore, both ends of the guide shaft 30 are connected to the second group frame 22.
Through the shaft support parts 22a and 22b without looseness (precision fitting)
At the same time, the shaft support 29b of the focusing frame 29 is inserted (free-fitting) with the gap X2. Then, the ultraviolet curable adhesive 32 is injected into the injection hole 29c of the shaft support portion.
And the guide shaft 30 is bonded and fixed. This adhesive fixation may be performed by using a general adhesive without necessarily using an ultraviolet curable adhesive.

By this bonding, the focusing frame 29 becomes
When the lens 42c is centered, the lens 42c is slidably supported by the second group frame 22 via the guide shaft 30. The bonded portion of the guide shaft 30 is provided with a cut 30a for preventing the bonded portion from shifting.

In the lens barrel 50 configured as described above, the rotating frame 2, the moving frame 5, and the lens frame supported by them are rotated by the rotation of the helicoid ring 4 supported by the moving frame 5. It is fed out from the retracted position to the shooting position. Furthermore, the rotating frame 2 is connected to the driving ring 3 in a state where the rotating frame 2 has reached the photographing position.

In the photographing state, the rotary frame 2 is rotationally driven by the drive ring 3 to rotate the cam frame M11 and the cam frame F1.
2, the first group frame 21, the second group frame 2, which is each lens frame.
The second and third group frames 23 are driven forward and backward to respective zoom positions. The focusing frame 29, which is supported by the second group frame 22 at each zoom position so as to be able to move forward and backward, is driven forward and backward to each focusing position by a focus drive system (not shown).

According to the lens barrel 50 incorporating the lens barrel of the present embodiment described above, the occupied space of the lens holding portion of the focusing frame 29 is larger than the adjustable lens 42c than the lens holding portion 29a. Second outer diameter portion 4
Since it is determined by 2 cB, the lens barrel becomes small, and the lens barrel 50 can be downsized. At the same time, since the second outer diameter portion 42cB of the lens to be adjusted 42cB is grasped and finely adjusted for centering and bonded and fixed, the optical centering accuracy of the lens group 42 in the focusing frame 29 is improved. further,
When the guide shaft 30 in the loosely fitted state is bonded to the focusing frame 29, the centering jig 71 directly supports and positions the second group frame 22 and the lens to be adjusted 42c, thereby improving centering accuracy. Thus, high optical accuracy can be obtained. In addition, the centering work is facilitated, and the cost can be reduced.

In the above embodiment, the lens 42
The outside diameter D2 of the second outside diameter portion 42cB of the lens holding portion 2c
The outer diameter D2 of the second outer diameter portion 42cB is set to be larger than the outer diameter D0 of the lens holding portion 2a.
Even when the outer diameter D0 is equal to or smaller than the outer diameter D0 of the lens holding portion 29a, the same effect can be obtained if the second outer diameter portion 42cB is exposed outside the lens holding portion 29a.

(Supplementary Note) Based on the above embodiment, the following configuration can be obtained. That is, (1) a lens having a first frame, a first outer diameter portion held by the first frame, and a second outer diameter portion having an outer diameter larger than the outer diameter of the first frame. And a second frame. The center of the frame of the second frame is aligned with the optical center of the lens at the second outer diameter portion of the lens and the fitting portion of the second frame. Lens frame structure characterized by having such a configuration.

(2) a first frame, a plurality of lenses held in the first frame, and one of the plurality of lenses,
A first outer diameter portion, an adjusted lens having a second outer diameter portion having an outer diameter larger than the outer diameter of the first frame, and a second frame;
Wherein the first outer diameter portion of the lens to be adjusted is held by the first frame, and the plurality of the plurality of lenses fitted to the first frame by the second outer diameter portion are provided. A lens mirror frame structure characterized in that the optical core of the lens is aligned with the core of the second frame.

(3) The lens according to appendix 2, wherein, when the centering is not adjusted, the support shaft supported in a loosely fitted state on the first frame is adjusted in position at the time of the optical centering and is adhered and fixed. Mirror frame structure.

(4) a first frame, a plurality of lenses held in the first frame, and one of the plurality of lenses,
An optical centering method for a lens barrel including an adjustable lens having a first outer diameter portion, a second outer diameter portion having an outer diameter larger than the outer diameter of the first frame, and a second frame. The first outer diameter portion of the lens to be adjusted is held by the first frame, and the plurality of the outer diameter portions fitted to the first frame by the second outer diameter portion. The optical center of the lens and the core of the second frame are aligned.

(5) The lens as described in appendix 4, wherein, when the centering is not adjusted, the position of the support shaft supported in a loosely fitted state on the first frame is adjusted and adhesively fixed at the time of the optical centering. An optical centering method for the mirror frame.

[0033]

As described above, according to the lens frame structure of the present invention, by optically centering the second frame via the second outer diameter portion of the lens, the lens mirror is formed. The centering of the frame is easy, the accuracy is improved, and the size of the lens barrel incorporating the lens barrel can be reduced.

Further, according to the optical centering method of the lens mirror frame of the present invention, by optically centering the second frame via the second outer diameter portion of the lens, the lens mirror can be adjusted. The centering of the frame is facilitated, and the optical accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a lens barrel incorporating a lens barrel according to an embodiment of the present invention, in which an upper half shows a shooting preparation state and a wide state, and a lower half shows a telephoto state. .

FIG. 2 is a longitudinal sectional view of the lens barrel of the embodiment.

FIG. 3 is a longitudinal sectional view showing a state where the lens barrel of FIG. 2 is mounted on a centering jig for bonding and fixing a focus lens.

FIG. 4 is a longitudinal sectional view when the lens barrel of FIG. 2 is mounted on a centering jig for bonding and fixing a guide shaft.

[Explanation of symbols]

22... 2 group frame (second frame) 29... Focusing frame (first frame) 42c... Lens to be adjusted (lens) 42cA... First outer diameter portion of lens 42cB. Second outer diameter portion 71... Centering jig (jig member) D0... Outer diameter of lens holding portion of focusing frame (outer diameter of first frame) D1 .first outer diameter portion of lens Diameter D2 Diameter of second outer diameter part of lens

Claims (3)

[Claims] A first outer diameter portion held by the first frame; and a second outer diameter portion having an outer diameter larger than an outer diameter of the first frame. A lens frame structure, comprising: a lens; and a second frame, wherein the optical axis of the lens is aligned with the frame center of the second frame. 2. A lens having a first frame, a first outer diameter portion held by the first frame, and a second outer diameter portion having an outer diameter larger than the outer diameter of the first frame. And an optical centering method of a lens frame comprising a second frame, wherein the optical center of the lens is aligned with the center of the frame of the second frame. Optical centering method. 3. A lens having a first frame, a first outer diameter portion held by the first frame, and a second outer diameter portion having an outer diameter larger than the outer diameter of the first frame. And an optical centering method of a lens frame including a second frame, wherein the positioning is performed by fitting to a second outer diameter portion of the lens and a fitting portion of the second frame. An optical centering method for a lens barrel, wherein a frame center of the second frame is aligned with an optical center of the lens using a tool member.