JP2003149521A - Alignment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-precision alignment device for an optical system, which can easily and securely carry out alignment by a simple mechanism and enables accurate adhesion and fixation in a shot period of time after the alignment. SOLUTION: The device is equipped with an external eccentric frame 2 which is supported inside a support member 1 and almost in an annular shape whose outer circumference and inner circumference are eccentric with each other and an internal eccentric frame 3 which is supported inside the external eccentric frame 2 and nearly in a annular shape whose outer circumference and inner circumference are eccentric with each other and supports a lens; and the outside circumferential wall surface of the external eccentric frame 2 and the inside circumferential wall surface of the support member 1 come into free slide contact with each other to engage the external eccentric frame 2 rotatably with the support member 1, the outside circumferential wall surface of the internal eccentric frame 3 and the inside circumferential wall surface of the outside eccentric frame 2 come into slide contact with each other to engage the internal eccentric frame rotatably with the external eccentric frame, and the internal and external eccentric frames (2, 3) are rotated to align the optical axis 7 of the lens 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centering device for an optical system, and more particularly to a centering device for a photographing optical system such as a digital video camera, a digital still camera, and a silver salt film camera.

[0002]

2. Description of the Related Art In recent years, along with the downsizing of photographic devices, the downsizing of photographic optical systems and the introduction of aspherical surfaces have made stricter the positional accuracy when assembling lenses. Therefore, there are increasing opportunities to mass-produce optical systems that have high eccentricity sensitivity and require alignment and assembly. In most conventional alignment techniques, alignment using the backlash between the lens and the frame is used, and in most cases only so-called shift alignment that moves the lens in the plane orthogonal to the optical axis is performed. It was In addition, in a small part of the products, a method was used in which the lens held in the air between the lens frames was bonded as it was after shift and tilt alignment, but the alignment device is complicated and expensive, and the adhesive There was a problem when the cycle time of the work became long, for example, it was necessary to hold the lens with a jig and tool until it hardened.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is an optical system which can be easily and surely aligned by a simple mechanism and can be accurately bonded and fixed in a short time after the alignment. An object is to provide a centering device with high system accuracy.

[0004]

According to a first aspect of the present invention, there is provided an outer eccentric frame which is supported inside a supporting member and has a substantially annular shape in which an outer circumference and an inner circumference are eccentric to each other, and the outer eccentric frame. An inner eccentric frame that is supported inside and has an outer circumference and an inner circumference that are eccentric to each other to support the lens in a substantially annular shape, and the outer circumferential wall surface of the outer eccentric frame and the support member The outer eccentric frame is rotatably fitted to the support member by slidably contacting with the inner circumferential wall surface, and the outer circumferential wall surface of the inner eccentric frame and the inner circle of the outer eccentric frame. The inner eccentric frame is rotatably fitted to the outer eccentric frame by slidably contacting the circumferential wall surface, and the eccentricity of the optical axis of the lens is adjusted by rotating the inner and outer eccentric frames. Characterized by alignment. With such a structure, the eccentricity can be adjusted two-dimensionally by doubling the eccentric frame.

According to a second aspect of the present invention, in the centering device according to the first aspect, at least one set of the wall surfaces of the support member and the outer eccentric frame, and the outer eccentric frame and the inner eccentric frame are in contact with each other. At least a part of the wall surface has a spherical shape, and the tilt eccentricity of the optical axis of the lens is adjusted by rotating an eccentric frame having the spherical shape. With such a configuration, it is possible to adjust the shift eccentricity in any direction and also to adjust the tilt eccentricity.

According to a third aspect of the present invention, in the aligning device according to the first aspect, at least a part of at least one set of the wall faces in contact with each other has a conical surface shape. . With such a configuration, it is possible to reduce fitting backlash and increase a contact area, and to perform accurate and stable alignment.

According to a fourth aspect of the present invention, in the centering device according to the first aspect, at least one of the inner and outer eccentric frames is a relief portion opened to a surface perpendicular to the optical axis of the lens and the wall surface in contact therewith. Is provided. With this configuration, by providing an escape portion with a concave cross-section including the optical axis, it is possible to avoid manufacturing and assembling by undercutting, increase adhesive strength by using an adhesive reservoir, improve appearance, etc. Is possible.

According to a fifth aspect of the present invention, in the centering device according to the first aspect, at least one of the inner and outer eccentric frames is provided with one or more concave or convex engaging portions, and the eccentric frame is fixed. By applying a tool, the holding of the frame, the centering operation, and the centering amount can be specified. With this configuration, it is possible to ensure that the centering frame is held by the centering device, and it is possible to predict the direction and amount of movement before actually moving the frame during the centering process, thus reducing the work time. Can be shortened.

According to a sixth aspect of the present invention, an outer eccentric frame 2 is supported inside the lens barrel 1 and has an outer circumference and an inner circumference that are eccentric to each other. A lens 4 which is supported and has a substantially annular shape in which the outer circumference and the inner circumference are decentered from each other.
And an inner eccentric frame 3 for supporting the inner eccentric frame 3, and at least a part of an outer circumferential wall surface of the outer eccentric frame 2 and an inner circumferential wall surface of the lens barrel 1 slidably contact each other. Thus, the outer eccentric frame 2 is rotatably fitted to the lens barrel 1, and at least a part of the outer circumferential wall surface of the inner eccentric frame 3 and the inner circumferential wall surface of the outer eccentric frame 2 is formed. Form spherical surfaces and slidably contact each other, so that the inner eccentric frame 3 is rotatably fitted to the outer eccentric frame 2, and the inner and outer eccentric frames are rotated to rotate the lens 4 of the lens 4. An aligning device for aligning optical axis shift and tilt eccentricity. With such a configuration, the shift and tilt eccentricities can be easily and reliably adjusted.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present embodiment will be described below with reference to the drawings. FIG. 1 is a top view of an example of the aligning device of the present invention. To describe the reference numerals, reference numeral 1 denotes a support member (for example, a lens barrel), which is a portion that serves as a base for supporting the adjusted lens 4. Reference numeral 2 denotes an outer eccentric frame located outside, and in this example, it is slidably in contact with a sliding surface (wall surface) with the lens barrel and is rotatably fitted therein. Reference numeral 3 denotes an inner eccentric frame located inside, and its outer circumferential surface (wall surface) is a spherical surface, slidably contacts the inner circumferential surface (wall surface) of the outer eccentric frame, and is rotatably fitted to the outer eccentric frame. Have been combined. The inner eccentric frame 3 has a structure for fixedly supporting the adjusted lens 4 therein.
Since the center axes of the inner and outer eccentric frames are eccentric, the lenses held by the inner and outer eccentric frames are slidably rotated by a combination of the positions of the two frames. Dimensionally shiftable centering is possible. Moreover, tilting eccentricity becomes possible by slidably contacting with a spherical surface here.

FIG. 2 is a cross-sectional view of the aligning device of the present invention. In the figure, a concave escape portion 5 is provided on the upper surface of the inner eccentric frame 3. By providing the escape portion on the eccentric frame, it is possible to assemble even if the spherical surface becomes deep. Further, an aligning jig fitting portion 6 (engagement portion of claim 5) is provided on the upper surface of the outer eccentric frame 2. Although it is a cylindrical hole in FIG. 1, it may have a shape that can be reliably fitted to the aligning jig regardless of the shape and unevenness.

FIG. 3 is a top plan view of an example of the eccentric frame according to this embodiment. In this example, as shown in the drawing, the angle from the center indicating the position of each columnar recess is different, that is, θ1 ≠ θ2 ≠ θ3 ≠ θ1. Thereby, the jig and tool can be easily and definitely engaged with the fitting portion to perform the centering operation.

4A and 4B show another example of the eccentric frame according to the present embodiment. FIG. 4A is a transverse sectional view and FIG. 4B is a plan view. In this example, the engaging portion is slit-shaped,
The slit widths shown in the drawing have a relationship of D1 ≠ D2 = D3. Setting the slit width in this manner allows easy and error-free engagement when applying the jig.

FIG. 5 is an explanatory diagram of an aligning process performed by the aligning device according to the present embodiment, (a) is an explanatory diagram for explaining the aligning operation, and (b) is detected by a sensor. The state before and after the centering of the shift eccentricity is shown, (c) shows the state before and after the adjustment detected by the sensor, (d) shows the state before and after the centering of the tilt eccentricity detected by the sensor, ( e)
Indicates the state before and after the alignment of the tilt eccentricity detected by using the interference fringes. As shown in FIG. 5A, the light from the light source 22 passes through the lens 4 to be aligned, and the fixed optical system 2
It passes through 4 and is focused on the sensor 25. When the focus is mainly eccentric to the shift, the focus detected as shown in (b) is separated from the center and focused. On the other hand, it is adjusted using jigs and tools, and it is centered so as to come to the center in the figure. In this way, the optical axis adjustment is performed by rotating the eccentric frame with a jig. Further, when the spherical aberration is significant, as shown in FIG. 5C, the focal point becomes a circular shape having an area instead of a point. Therefore, this is also reduced to a certain extent by aligning the inner and outer eccentric frames. Then, the influence of spherical aberration can be suppressed. When the tilt is decentered, the optical axis is not orthogonal to the surface of the sensor 25. Therefore, as shown in (d), the focal point of the light beam is not a perfect circle but a distorted shape such as an ellipse. In aligning tilt eccentricity,
A method using interference fringes is also possible and is shown in (e).
At this time, a laser beam is used as a light source. The tilt eccentricity is adjusted by sliding and rotating a wall surface in contact with a spherical surface using a jig so that the light flux becomes a perfect circle as shown in (d) and (e). Sensor 25 here
A CCD or a television camera can be used as the.

FIG. 6 is a schematic explanatory view for explaining an aligning operation performed on the inner and outer eccentric frames by using a jig. The sensor receives light rays that have passed through the eccentric frame and the lens unit, analyzes the characteristics (blur size, symmetry, etc.), and calculates the direction and amount of eccentricity adjustment of the lens. At this time, by setting the positional relationship between the adjusting jig and the eccentric frame to be one-to-one, the moving direction of the lens eccentricity can be predicted from the rotation direction and amount of the jig. In the case of the drawing, the claw of the adjusting jig is engaged with the engaging portion (centering jig fitting portion) provided on the frame from above the outer side of the frame to rotate the frame, thereby performing centering. Further, after alignment, an adhesive 35 is applied to the eccentric frame to firmly fix it. Here, preferably, the relief portion 5 as shown in FIG. 2 may be provided and the adhesive may be injected therein.

[0016]

According to the invention of claim 1, by providing two eccentric frames, it is possible to provide an aligning device which is easy and has high accuracy. According to the second aspect of the invention, it is possible to provide an easy and highly accurate centering device capable of not only shift centering but also tilt centering. According to the third aspect of the present invention, it is possible to provide an aligning device capable of suppressing the backlash of the eccentric frame to be low and performing accurate alignment. According to the invention of claim 4, eccentric frame manufacturing
It is possible to provide a highly accurate aligning device that can be easily assembled and can be firmly bonded and fixed without deteriorating the appearance quality. According to the invention of claim 5, the movement of the eccentric frame can be ensured, and the moving direction of the lens optical axis can be predicted and calculated before the centering device moves the eccentric frame. It is possible to provide an aligning device with high work efficiency that can finish the process. According to the sixth aspect of the present invention, it is possible to provide an optical system alignment device capable of easily and surely performing shift and tilt alignment with a simple mechanism.

[Brief description of drawings]

FIG. 1 is a top plan view of an aligning device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the centering device according to the present embodiment.

FIG. 3 is a top plan view of an example of the eccentric frame according to the present embodiment.

FIG. 4 shows another example of the eccentric frame according to the present embodiment,
(A) is a cross-sectional view and (b) is a plan view.

5A and 5B are explanatory diagrams of an aligning process performed by the aligning device according to the present embodiment, FIG. 5A is an explanatory diagram illustrating an aligning operation, and FIG. 5B is a diagram illustrating shift eccentricity detected by a sensor. Before and after alignment, (c) shows before and after the adjustment detected by the sensor, (d) shows before and after the alignment of the tilt eccentricity detected by the sensor, and (e) is detected using the interference fringes. The front and the rear of the aligned tilt eccentricity are shown.

FIG. 6 is a schematic explanatory view illustrating an aligning operation performed by using a jig for inner and outer eccentric frames.

[Explanation of symbols]

1 Support member 2 Outer eccentric frame 3 Inner eccentric frame 4 lenses 5 escape area 6 Aligning jig fitting part 7 Optical axis

Claims (6)

[Claims] 1. An outer eccentric frame, which is supported inside the supporting member and has a substantially annular shape in which an outer circumference and an inner circumference are eccentric to each other, and an outer circumference and an inner circle which are supported inside the outer eccentric frame. An inner eccentric frame for supporting the lens in a substantially annular shape whose eccentricity is eccentric to each other, and an outer circumferential wall surface of the outer eccentric frame and an inner circumferential wall surface of the support member are slidable. By contacting, the outer eccentric frame is rotatably fitted to the support member, and the outer circumferential wall surface of the inner eccentric frame and the inner circumferential wall surface of the outer eccentric frame slidably contact each other. The inner eccentric frame is rotatably fitted to the outer eccentric frame, and the eccentricity of the optical axis of the lens is adjusted by rotating the inner and outer eccentric frames. . 2. At least a part of at least one set of wall surfaces of a set of wall surfaces in contact with the support member, the outer eccentric frame, and the outer eccentric frame and the inner eccentric frame has a spherical shape. The aligning device according to claim 1, wherein the tilt decentering of the optical axis of the lens is aligned by rotating an eccentric frame having a spherical shape. 3. At least one of said contacting wall surface pairs
The centering device according to claim 1, wherein at least a part of the wall surfaces of the set has a conical surface shape. 4. The at least one of the inner and outer eccentric frames is provided with an open relief portion on a surface perpendicular to the optical axis of the lens and on the contacting wall surface. Aligning device. 5. At least one of the inner and outer eccentric frames is provided with one or more concave or convex engaging portions, and by applying a jig, holding, aligning operation and adjusting of the frame are performed. The centering device according to claim 1, wherein the heart rate can be specified. 6. An outer eccentric frame 2 which is supported inside the lens barrel 1 and has a substantially annular shape in which an outer circumference and an inner circumference are eccentric to each other, and an outer circumference which is supported inside the outer eccentric frame 2. Is provided with an inner eccentric frame 3 that supports the lens 4 in a substantially annular shape in which the inner circumference and the inner circumference are eccentric to each other, the outer circumferential wall surface of the outer eccentric frame 2 and the inner circumferential direction of the lens barrel 1. The outer eccentric frame 2 is rotatably fitted in the lens barrel 1 by at least a part of the wall surface forming a conical surface and slidably contacting each other, and the outer eccentric frame 3 has an outer circumferential direction. The inner eccentric frame 3 is rotatably fitted to the outer eccentric frame 2 by at least a part of the wall surface and the inner circumferential wall surface of the outer eccentric frame 2 forming spherical surfaces and slidably contacting each other. The optical axis shift and tilt decentering of the lens 4 are adjusted by rotating the inner and outer decentering frames. Aligning apparatus characterized by.