JP3996709B2 - Lens frame structure and optical centering method of lens frame - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens barrel structure capable of optical centering adjustment and an optical centering method of the lens barrel.
[0002]
[Prior art]
Conventionally, as a proposal regarding a lens barrel capable of optical centering adjustment or an optical centering method thereof, Japanese Patent Laid-Open No. 59-107307, Japanese Utility Model Laid-Open No. 59-68306, Japanese Utility Model Laid-Open No. 59 No. -12608, No. 59-161108, No. 59-68710, No. 59-69708, No. 60-129715, No. 59-159111, etc. is there. These proposals all relate to a lens barrel in which a lens to be centered and adjusted is held in the lens frame.
[0003]
On the other hand, in recent years, there has been an increasing need for compact optical devices such as cameras, and in order to meet this demand, it is inevitable that the lens frame will be downsized.
[0004]
[Problems to be solved by the invention]
However, the lens barrel capable of optical centering adjustment proposed in the above-mentioned publications is held in a state where the lens to be centered and adjusted is housed inside the lens frame as described above. 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 downsizing of the lens frame. Further, when the optical centering adjustment of the lens is performed, the lens positioning operation is difficult because the lens is within the lens frame, and the optical centering adjustment is difficult.
[0005]
The present invention has been made in order to solve the above-described problems. A lens barrel structure and a lens mirror in which the lens barrel can be reduced in size and size and optical centering adjustment is easy. An object of the present invention is to provide a method for adjusting the optical core of a frame.
[0006]
[Means for Solving the Problems]
The lens barrel structure according to claim 1 of the present invention includes a first frame, a first outer diameter portion held by the first frame, and a second outer diameter portion exposed to the outside of the frame. A lens, a guide shaft that is bonded and fixed to the first frame and guides the first frame in the optical axis direction, supports the guide shaft slidably, and supports the first frame in the optical axis direction; a frame member for moving the, comprising a second frame having a fitting portion for combining the optical core of the frame center and the lens of the frame member, a fitting above the second frame It is assembled by a jig that fits to the joint portion and the second outer diameter portion of the lens to perform the adhesive fixing of the guide member.
[0007]
[Means for Solving the Problems]
According to a second aspect of the present invention, there is provided a lens barrel optical centering method comprising: a first frame; a first outer diameter portion held by the first frame; and a second outer portion exposed outside the frame. A lens having a diameter portion, a guide shaft that is bonded and fixed to the first frame and guides the first frame in the optical axis direction, the guide shaft is slidably supported, and the first frame An optical core of a lens barrel comprising a second frame having a fitting portion for aligning the frame center of the frame member with the optical core of the lens. And a jig member that fits and positions the second outer diameter portion of the lens and the fitting portion of the second frame, and the center of the frame of the second frame and the above-described method. It is characterized by matching the optical core of the lens .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described 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 photographing enabled state, where the upper half is in the wide state and the lower half is in the tele state. Indicates. The lens barrel 50 is a retractable lens barrel, and all the movable lens frames are moved from the state of FIG. 1 to the retracted position in the fixed frame 1 and stored when not photographing. To do.
[0010]
The lens barrel 50 holds a retractable drive system that performs forward / backward drive between the retracted position and the shooting preparation position, that is, a retractable drive area, a lens group drive system that drives the lens group frame, and each lens group. It consists of a lens group frame.
[0011]
The collapsible drive system is fixedly supported mainly by the camera body 51, moves forward and backward between the retracted position and the photographing preparation position, and the fixed frame 1 having a helicoid driving gear (not shown) and the driving ring 3. The rotating frame 2 that rotates between the wide position and the tele position, the helicoid ring 4 that is rotatably supported by the moving frame 5 to be described later, and the optical axis O between the retracted position and the photographing position together with the rotating frame 2. And a moving frame 5 that moves straight along.
[0012]
The lens group drive system is mainly inserted into the moving frame 5 and driven forward / backward, rotates with the rotary frame 2, rotates with the cam frame M 11, and rotates with the cam frame M 11, and moves forward / backward through the second group frame 22. The cam frame F12 is driven, the key ring 13 guides the lens group linearly, and the movable flare stop 15 supported by the cam frame M11 and moving linearly.
[0013]
The lens group frame portion is built in the cam frame M11 and the cam frame F12, and includes lens group holding frames that move straight. That is, the first group frame 21 that is driven forward / backward through the cam frame F12 and holds the first group lens 41, and the second frame that is linearly guided through the key ring 13 and driven forward / backward by the cam frame M11. A certain second group frame 22, a movable follower 28 that is driven forward / backward via a cam frame F 12, a third group frame 23 that is driven forward / backward via the movable follower 28 and holds a third group lens 43, and the second group frame 22 The focusing frame 29 is a first frame that is held so as to be relatively movable back and forth, and is linearly driven along the optical axis O by a focusing drive system (not shown).
[0014]
FIG. 2 is a longitudinal sectional view of the focusing frame 29. The focusing frame 29 holds a plurality of lenses 42a and 42b constituting the focusing second group lens 42 and a lens 42c to be adjusted. The lens to be adjusted 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.
[0015]
Further, a guide shaft 30 that is slidably supported by the second group frame 22 without looseness is bonded and fixed to the focusing frame 29. Therefore, the focus frame 29 is supported so as to be able to move forward and backward relative to the second group frame 22 along the optical axis O. The focusing frame 29 is guided linearly by the guide shaft 30 and, at the same time, the rotation around the optical axis O is restricted by a non-rotating member (not shown) provided in the second group frame 22.
[0016]
The outer diameter portions of the lenses 42a and 42b are fitted (precisely fitted) into the inner diameter portion of the lens holding portion 29a without looseness, and are directly bonded and fixed. On the other hand, the lens 42c as the lens to be adjusted has a large influence on the optical performance of the optical misalignment, so that the first outer diameter portion 42cA of the lens 42c has a gap X1 from the fitting portion of the lens holding portion 29a. The second outer diameter portion 42cA is centered by being fitted (fixed fit) in a state, and the second outer diameter portion 42cA is operated by a centering jig 61 (see FIG. 3), which will be described later.
[0017]
The outer diameter D2 of 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 exposed from the end surface of the lens holding portion 29a. At the time of adjustment, the second outer diameter portion 42cB can be adjusted by operating from the outside.
[0018]
FIG. 3 is a vertical cross-sectional view in a state where a centering jig for attaching and fixing the lens 42c to the focusing frame 29 is mounted. When performing the above-described bonding, first, the focusing frame 29 in a state where the lenses 42 a and 42 b are fixed inside the lens holding portion 29 a 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 are fitted.
[0019]
With the focusing frame mounted, the first outer diameter portion 42cA of the lens 42c is inserted into the inner diameter portion of the lens holding portion 29a of the focusing frame with a gap X1 (free fitting). Then, the position of the lens 42c is finely adjusted via the second outer diameter portion 42cB, and optical alignment of the lenses 42a, 42b and the lens 42c is performed by a chart image monitor using laser light. Therefore, an ultraviolet curable adhesive 31 is injected and bonded to the gap X1.
[0020]
FIG. 4 is a vertical cross-sectional view showing a state in which 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 attached by fitting the positioning outer peripheral portion 22e of the second group frame 22 to the frame positioning reference inner peripheral portion 71e of the centering jig 71.
[0021]
Further, the second outer diameter portion 42cB of the lens 42c already fixed to the focusing frame 29 is fitted into the lens positioning reference inner peripheral portion 71b of the centering jig 71, and the focusing frame 29 is attached. In this mounted state, the optical centering of the lens 42c with respect to the second lens group frame 22 is performed.
[0022]
Therefore, both ends of the guide shaft 30 are inserted into the shaft support portions 22a and 22b of the second group frame 22 without play (precise fitting), and at the same time, the shaft support portion 29b of the focusing frame 29 is inserted with a gap X2 (free fitting). Fit). Then, the UV curable adhesive 32 is injected from the injection hole 29c of the shaft support portion to bond and fix the guide shaft 30. This adhesive fixing may be performed with a general adhesive without necessarily using an ultraviolet curable adhesive.
[0023]
By this adhesion, the focusing frame 29 is slidably supported by the second group frame 22 via the guide shaft 30 in the centered state of the lens 42c. Note that a notch 30 a is provided at the bonded portion of the guide shaft 30 to prevent the bonded portion from shifting.
[0024]
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 moved from the retracted position by the rotation of the helicoid ring 4 supported by the moving frame 5. It is extended to the shooting position. Further, the rotating frame 2 is connected to the drive ring 3 in a state where the photographing position is reached.
[0025]
In the above photographing state, the rotary frame 2 is rotationally driven by the drive ring 3, and the first group frame 21, the second group frame 22, and the third group frame 23, which are the lens barrels, via the cam frame M 11 and the cam frame F 12. Drives forward and backward to each zoom position. The focusing frame 29 supported by the second group frame 22 so as to be able to advance and retract at each zoom position is driven to advance and retract to each focusing position by a focus drive system (not shown).
[0026]
According to the lens barrel 50 incorporating the lens barrel of the present embodiment described above, the second space of the adjusted lens 42c in which the space occupied by the portion of the focusing frame 29 that holds the lens is larger than that of the lens holding portion 29a. Therefore, the lens barrel can be made smaller, and the lens barrel 50 can be downsized. At the same time, the second outer diameter portion 42cB of the lens 42c to be adjusted is grasped and finely adjusted to be adhered and fixed, so that the optical centering accuracy of the lens group 42 in the focusing frame 29 is improved. Further, when the loosely fitted guide shaft 30 is bonded to the focusing frame 29, the second group frame 22 and the lens to be adjusted 42c are directly supported and positioned by the centering jig 71. And high optical accuracy is obtained. In addition, the centering work becomes easy and the price can be reduced.
[0027]
In the above-described embodiment, the outer diameter D2 of the second outer diameter portion 42cB of the lens 42c is set larger than the outer diameter D0 of the lens holding portion 29a. Even if the outer diameter D2 of the 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 is exposed to the outside of the lens holding portion 29a. A similar effect can be obtained.
[0028]
(Appendix)
Based on the above-described embodiment, the following configuration can be obtained. That is,
(1) the first frame;
A first outer diameter portion held by the first frame, and a lens having a second outer diameter portion having an outer diameter larger than the outer diameter of the first frame;
A second frame;
And the second outer diameter portion of the lens and the fitting portion of the second frame are configured to match the frame center of the second frame and the optical core of the lens. Lens frame structure to be used.
[0029]
(2) the first frame;
A plurality of lenses held in the first frame;
A lens to be adjusted which is one of the plurality of lenses and has a first outer diameter portion and a second outer diameter portion having an outer diameter larger than the outer diameter of the first frame;
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 plurality of the first outer diameter portions are fitted to the first frame by the second outer diameter portion. A lens barrel structure characterized in that the optical core of the lens is aligned with the core of the second frame.
[0030]
(3) The lens barrel structure according to appendix 2, wherein when the centering is not adjusted, a support shaft supported in a loosely fitted state on the first frame is adjusted and bonded and fixed when the optical centering is performed. .
[0031]
(4) The first frame, the plurality of lenses held by the first frame, and one of the plurality of lenses, the first outer diameter portion and the outer diameter of the first frame. An optical centering method for a lens barrel comprising a second lens and an adjusted lens having a second outer diameter portion having a large outer diameter,
The first outer diameter portion of the lens to be adjusted is held by the first frame, and the plurality of lenses optically fitted into the first frame by the second outer diameter portion. An optical centering method for a lens barrel characterized by aligning the center of the target and the core of the second frame.
[0032]
(5) The lens barrel according to appendix 4, wherein when the centering is not adjusted, the support shaft supported in a loosely fitted state on the first frame is adjusted and bonded and fixed during the optical centering. Optical centering method.
[0033]
【The invention's effect】
As described above, according to the lens barrel structure of the present invention, the lens barrel can be centered by optically centering the second frame via the second outer diameter portion of the lens. The lens barrel incorporating the lens barrel can be reduced in size easily and with improved accuracy.
[0034]
According to the optical centering method of the lens barrel of the present invention, the center of the lens barrel is obtained by optically centering the second frame via the second outer diameter portion of the lens. It is easy to take out 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 that is an embodiment of the present invention, in which the upper half shows a shooting preparation state and a wide state, and the lower half shows a tele state. .
FIG. 2 is a longitudinal sectional view of a lens barrel of the embodiment.
3 is a longitudinal sectional view of the lens barrel of FIG. 2 mounted on a centering jig for fixing and fixing a focusing lens.
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 (2nd frame)
29 …… Focusing frame (first frame)
42c: Lens to be adjusted (lens)
42cA: Lens first outer diameter portion 42cB: Lens second outer diameter portion 71: Centering jig (jig member)
D0 ...... Outer diameter of the lens holding part of the focusing frame (outer diameter of the first frame)
D1 ... Diameter of the first outer diameter portion of the lens D2 ... Diameter of the second outer diameter portion of the lens

Claims (2)

A first frame;
A first outer diameter portion held by the first frame, and a lens having a second outer diameter portion exposed outside the frame;
A guide shaft that is bonded and fixed to the first frame and guides the first frame in the optical axis direction;
A frame member that slidably supports the guide shaft and moves the first frame in the optical axis direction, and a fitting portion for aligning the frame center of the frame member with the optical core of the lens A second frame having;
And is assembled with a jig for fitting and fixing the guide member by fitting to the fitting portion of the second frame and the second outer diameter portion of the lens. A lens frame structure. A first frame, a lens having a first outer diameter portion held by the first frame, and a second outer diameter portion exposed to the outside of the frame; and the first frame fixedly bonded to the first frame. A guide shaft for guiding the frame in the optical axis direction, and a frame member that slidably supports the guide shaft and moves the first frame in the optical axis direction, the frame center of the frame member And an optical centering method of a lens barrel comprising a second frame having a fitting portion for matching the optical core of the lens,
Using a jig member that fits and positions the second outer diameter portion of the lens and the fitting portion of the second frame, the frame center of the second frame and the optical core of the lens A method for optically centering a lens barrel, characterized in that

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