JP2000098207A - 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 focus frame 29, focusing lenses 42a and 42b and a lens to be adjusted 42c, and the lenses 42a and 42b are held at the inside of the lens holding part 29a of the focus frame 29, and the lens to be adjusted 42c is inserted in a state where a first outside diameter part 42cA is movably fit at the inside of the lens holding part 29a and a second outside diameter part 42cB is exposed from the end face of the lens holding part 29a. Then, the centering adjustment of the lens to be adjusted 42c is executed by operating the second outside diameter part 42cB, so that it is stuck and fixed to the focus frame 29.

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 Application Laid-Open No. Sho 59-68306 have been proposed. Gazette, Shokai 59-121608
JP, JP-A-59-161108, JP-A-59-161108
-68710, JP-A-59-69708,
JP-A-60-129715, JP-A-59-159
No. 111 publication. All of these proposals relate to a lens barrel in which a lens whose centering is adjusted is held in a state of being housed in a lens holding portion of 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 capable of optical centering adjustment proposed in each of the above publications, the lens whose centering is adjusted is held inside the lens frame. Therefore, the space obtained by adding the thickness of the lens frame to the outer diameter of the lens is the occupied space, which hinders downsizing of the lens frame. 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 it is possible to reduce the size and size of the lens barrel, and furthermore, to provide a lens barrel structure and an optical centering adjustment which are easy. An object of the present invention is to provide a method for adjusting an optical center of a lens barrel.

[0006]

According to a first aspect of the present invention, a lens frame structure includes a lens frame, a first outer diameter portion, and a second outer diameter portion exposed from an end surface of the lens frame. And a lens fitted into the lens frame.
The outer diameter portion is loosely fitted to the lens frame, and optical centering is performed via the second outer diameter portion.

According to a second aspect of the present invention, an optical centering method for a lens frame includes a lens frame, a first outer diameter portion, and a second outer diameter portion exposed from an end surface of the lens frame. An optical centering method for a lens frame including a lens fitted to the lens frame, wherein a first outer diameter portion of the lens is loosely fitted to the lens frame, and a second outer diameter portion is provided. The optical centering is performed via.

According to a third aspect of the present invention, there is provided a lens frame structure comprising a lens frame, a first outer diameter portion, and a second outer diameter portion larger than the outer diameter portion of the lens frame. The first outer diameter portion of the lens is loosely fitted to the lens frame, and the loosely fitted portion performs optical centering.

According to a fourth aspect of the present invention, an optical centering method for a lens barrel includes a lens frame, a first outer diameter portion, and a second outer diameter portion larger than the outer diameter portion of the lens frame. An optical centering method of a lens frame including a lens fitted to the lens frame, wherein the first outer diameter portion is loosely fitted to the lens frame, and the loosely fitted portion forms an optical center. Delivery is performed.

According to a fifth aspect of the present invention, there is provided a lens frame structure comprising a lens frame, a plurality of lenses fitted to the lens frame, and one of the plurality of lenses, wherein A lens having a second outer diameter portion larger than the outer diameter portion of the lens frame, wherein the first lens of the one of the plurality of lenses is
The outer diameter portion is loosely fitted to the lens frame, and optical centering is performed at the loosely fitted portion.

According to a sixth aspect of the present invention, there is provided a method of optically centering a lens barrel, comprising: a lens frame; a plurality of lenses fitted to the lens frame; and one of the plurality of lenses. 1. A method for optically centering a lens barrel comprising: an outer diameter portion of a first lens and a lens having a second outer diameter portion larger than the outer diameter portion of the lens frame, wherein one of the plurality of lenses is The first outer diameter portion is loosely fitted to the lens frame, and optical centering is performed at the loosely fitted portion.

[0012]

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 retractable position from the retracted 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 fitted 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 which moves linearly. That is, the first group frame 21 that is driven forward and backward through the cam frame F12 and holds the first lens group 41, and the second group frame 22 that is linearly guided through the key ring 13 and driven forward and backward by the cam frame M11. , Cam frame F
The movable follower 28 is driven forward and backward through the movable lens 12, the movable follower 28 is driven forward and backward through the movable follower 28, and the third group frame 23 holding the third lens group 43 and the second group frame 22 are relatively movably held by the second group frame 22. And a focusing drive system (not shown)
And a focusing frame 29 which is a lens frame driven straight along the optical axis O.

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, since the lens to be adjusted 42c has a large effect on the optical performance due to the optical misalignment, the first outer diameter portion 42cA of the lens 42c is placed in a state where there is a gap X1 with the fitting portion of the lens holding portion 29a. The fitting (free-fitting) is performed, and a centering jig 61 described later is inserted.
(See FIG. 3), the second outer diameter portion 42cB is operated to adjust the centering, and is fixed by bonding.

The outer diameter D2 of the second outer diameter portion 42cB of the lens to be adjusted 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. Thus, the second outer diameter portion 42cB can be externally operated during the centering adjustment.

FIG. 3 is a longitudinal sectional view showing a state in which a centering jig for attaching and fixing the lens to be adjusted 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 that time, the reference inner peripheral portion 29e of the focusing frame
And the reference outer peripheral portion 61e of the centering jig.

With the focusing frame mounted, the first outer diameter portion 42cA of the lens to be adjusted 42c is inserted (free-fitting) into the inner diameter portion of the lens holding portion 29a of the focusing frame with a gap X1. Then, the position of the lens 42c is finely adjusted through the second outer diameter portion 42cB, and the lenses 42a and 42b are optically aligned with the lens 42c to be adjusted by a chart image monitor using laser light. Therefore,
An ultraviolet curable adhesive 31 is injected into the gap X1 and bonded.

Also, as described above, the focusing frame 2
The guide shaft 30 is bonded and fixed to 9. The bonding and fixing is performed by using the centering jig to fix the second outer diameter portion 42 cB of the adjusted lens 42 c which is already fixed to the second group frame 22. The positioning is performed by fitting (freely fitting) the guide shaft 30 into the shaft support portion 29b having the gap X2. The above bonding is
The ultraviolet curing adhesive 32 is injected into the gap X2 from the injection hole 29c provided in the shaft support portion 29b. In addition,
The bonded portion of the guide shaft 30 is provided with a notch 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 movable 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 second portion of the adjustable lens 42c in which the largest portion of the occupied space around the focusing frame 29 is exposed from the focusing frame 29. Since the outer diameter 42cB of the lens barrel 50 is used, the size of the lens barrel is reduced, and the size of the lens barrel 50 can be reduced. At the same time, the adjusted lens 42c
When the lens is centered on the focusing frame 29, the second outer diameter portion 42cB of the lens 42c exposed to the outside of the frame can be finely adjusted by operating the lens from outside, so that the optical center of the lens group 42 can be adjusted. This makes it easy to carry out, and high precision and low cost can be realized.

In the above embodiment, the outer diameter D2 of the second outer diameter portion 42cB of the lens to be adjusted 42c is set to be larger than the outer diameter D0 of the lens holding portion 29a.
However, the present invention is not limited to this, and even when the outer diameter D2 of the second outer diameter portion 42cB is equal to or smaller than the outer diameter D0 of the lens holding portion 29a, the second outer diameter portion 42cB may be smaller than the lens holding portion 29c.
A similar effect can be obtained if it is exposed to the outside of a.

(Supplementary Note) Based on the above embodiment, the following configuration can be obtained. That is, (1) a lens frame, a plurality of lenses fitted to the lens frame, and one of the plurality of lenses, wherein the first outer diameter portion and the first outer diameter portion are larger than the outer diameter portion of the lens frame. An adjustable lens having an outer diameter portion of 2. The first outer diameter portion of the adjusted lens is loosely fitted to the lens frame, and the second outer diameter portion adjusts the optical property of the adjusted lens. A lens frame structure for optically centering a target core and an optical core of another of the plurality of lenses.

(2) A lens frame, a plurality of lenses fitted to the lens frame, and one of the plurality of lenses, the first outer diameter portion being larger than the outer diameter portion of the lens frame. 2. An optical centering method for a lens barrel, comprising: an adjusted lens having an outer diameter of 2;
And the second outer diameter is used to center the optical core of the lens to be adjusted and the optical cores of the other lenses of the plurality of lenses. Optical centering method of the lens barrel.

[0030]

According to the lens frame structure of the present invention as described above, the first outer diameter portion of the lens is loosely fitted to the lens frame,
Since the optical centering is performed via the second outer diameter portion, the size of the lens barrel in which the lens barrel is incorporated can be reduced.

According to the optical centering method of the lens barrel of the present invention, the first outer diameter portion of the lens is loosely fitted to the lens frame, and the optical centering is performed via the second outer diameter portion. Is performed, the lens barrel can be easily assembled, 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.

[Explanation of symbols]

29 Focusing frame (lens frame, lens mirror frame) 29a Lens holding portion of focusing frame (outer diameter portion of lens frame) 42c Adjustable lens for focusing (lens, lens mirror frame) 42cA First outer diameter portion 42cB... Second outer diameter portion of the lens

Claims (6)

[Claims] 1. A lens frame, a first outer diameter portion, and a second exposed from an end surface of the lens frame.
And a lens fitted to the lens frame, wherein a first outer diameter portion of the lens is loosely fitted to the lens frame, and the second outer diameter portion is A lens frame structure characterized in that optical centering is performed through the lens. 2. An optical system for a lens barrel, comprising: a lens frame; a first outer diameter portion; and a second outer diameter portion exposed from an end face of the lens frame, and a lens fitted to the lens frame. A centering method, wherein a first outer diameter portion of the lens is loosely fitted to the lens frame,
An optical centering method for a lens barrel, wherein the optical centering is performed via the second outer diameter portion. 3. A lens frame, a first outer diameter portion, and a second outer diameter portion larger than the outer diameter portion of the lens frame.
And the lens supported by the lens frame. The first outer diameter portion of the lens is loosely fitted to the lens frame. A lens frame structure characterized by performing centering. 4. A lens frame including a lens frame, a first outer diameter portion, and a second outer diameter portion larger than the outer diameter portion of the lens frame, the lens frame including a lens fitted to the lens frame. An optical centering method for a lens frame, wherein the first outer diameter portion is loosely fitted to the lens frame and optical alignment is performed at the loosely fitted portion. Method. 5. A lens frame, a plurality of lenses fitted to the lens frame, one of the plurality of lenses, a first outer diameter portion, and a first outer diameter portion larger than the outer diameter portion of the lens frame. A lens having an outer diameter of 2 and a first lens of the one of the plurality of lenses.
The outer diameter portion is loosely fitted to the lens frame, and optical centering is performed at the loosely fitted portion. 6. A lens frame, a plurality of lenses fitted to the lens frame, and one of the plurality of lenses,
And a lens having a second outer diameter portion that is larger than the outer diameter portion of the lens frame. 1. An optical centering method for a lens barrel, wherein the outer diameter portion is loosely fitted to the lens frame, and optical alignment is performed at the loosely fitted portion.