JPH08201673A - Eccentricity adjusting device for lens and parallax adjusting device using the same - Google Patents

Abstract

PURPOSE: To provide the eccentricity adjusting device for a lens applicable to a movable lens and easily performing an adjusting operation by a constitution as simplified as possible, and to provide a parallax adjusting device using the same. CONSTITUTION: A guide shaft 9 whose cross-section is circular and a guiding member 10 provided with an engaging groove 10a are disposed along the optical axis direction of the finder optical system of a camera, and the guide shaft 9 is fitted in a fitting hole 7a provided at the top end of an arm 7 integrally formed at a second lens holder 6, and an eccentric pin 8 is engaged with the engaging groove 10a, so that a second lens 5 is maintained to be perpendicular to an optical axis and is supported to be able to straight advance in the optical axis direction. Also, the second lens 5 is eccentrically adjusted upward and downward at the inside of a surface perpendicular to the optical axis by rotating the eccentric pin 8, so that the parallax adjustment of the finder optical system is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentricity adjusting device for a lens in an optical system of a camera and a parallax adjusting device using the same.

[0002]

2. Description of the Related Art Conventionally, in a camera or the like having a photographing optical system and a finder optical system separately, a deviation (hereinafter referred to as parallax) between a photographing range and a visual field range (or a photographing range frame in a finder visual field) is corrected. Measures have been taken. The causes of parallax are that the center of the optical system is out of the expected position, the center of each lens is out of the expected position, the positional accuracy of the prism is not appropriate, and the visual field range is restricted. The position of the sheet with holes (which is called the optical image frame or the field frame depending on the type of the optical system) that is inserted in the focus surface for the purpose of displaying the shooting range frame in the finder field (or at the proper position) What you are doing. Parallax occurs when one or more of these causes overlap.

Generally, in a photographing range or a visual field range of a camera or the like, a vertical length ratio and a horizontal length ratio are not often 1: 1. However, a parallax amount (an image appearing in the visual field range due to parallax) caused by a manufacturing error or the like. The length by which the position of (1) is displaced within the shooting range) itself occurs at the same rate in both the short side direction and the long side direction. Here, considering the case where a certain amount of parallax occurs regardless of the direction, the ratio of the amount of parallax to the total length (short side or long side length) of the shooting range or field of view is in the short side direction. Is larger than in the long side direction. Therefore, the parallax generated in the short side direction becomes more conspicuous than the parallax generated in the long side direction, and therefore, the allowable amount for the error factor causing the parallax is smaller in the short side direction than in the long side direction. In a general camera, the vertical or vertical direction of the shooting range or field of view is shorter than that of the horizontal direction, so the design target for vertical parallax is stricter than for horizontal parallax, but this parallax is usually reduced by working errors. Since it is difficult to fit within the allowable amount, it is necessary to adjust parallax particularly in the vertical direction.

As a simple and effective method for adjusting the parallax, there is a method of adjusting the eccentricity of one lens in the objective lens group of the finder optical system. This method is roughly classified into a method of adjusting the angle of the optical axis of one lens in the objective lens group (hereinafter referred to as a tilt decentering adjustment method) and an optical axis of one lens in the objective lens group. There are two methods of parallel displacement (hereinafter referred to as parallel eccentricity adjustment method).

As a lens eccentricity adjusting device using the tilt eccentricity adjusting method, there is a configuration used in a finder device disclosed in Japanese Patent Laid-Open No. 59-162408. This configuration is intended to adjust parallax. This is
As shown in FIG. 6, the concave lens 102 supported by the lens frame 108 and urged from the rear by the leaf spring 109 from the front to the eccentric pin 110 of the eccentric shaft 110 for adjustment.
After positioning by a, the front and rear positions of the eccentric pin 110a are changed by rotating the adjustment eccentric shaft 110, and the angle of the optical axis of the concave lens 102 is adjusted to adjust the display position of the photographing range frame in the viewfinder field. The adjustment is performed (that is, the parallax is adjusted). On the optical axis XX ′ of the finder optical system, in addition to the concave lens 2, the objective lens 101, the flat glass 103, and the eyepiece lens 104.
Is arranged. In addition, the lens front frame 107 includes an objective lens 101 in the device main body 100 that holds the finder optical system.
Is installed.

As a lens eccentricity adjusting device using the parallel eccentricity adjusting method, there is a conventional structure shown in FIG. This is achieved by engaging the lens holder 131 holding the lens 130 with the engaging groove 135 of the supporting member 134 so as to be slidable in the direction perpendicular to the optical axis, and at the same time, the leaf spring 1
33 is brought into contact with one end of the lens holder 131 to urge the lens holder 131 in one direction, and the adjustment screw 132 is brought into contact with the other end of the lens holder 131 to rotate the lens holder 131 to the optical system. The displacement is performed in the direction perpendicular to the axis (that is, the optical axis of the lens 130 is translated).

Further, as a configuration capable of simultaneously performing the tilt eccentricity adjusting method and the parallel eccentricity adjusting method, there is a conventional technique shown in FIG. This is because the lens holder 141 holding the lens 140 is further held by the holder 143 in a double structure so that the angle of the optical axis of the lens can be adjusted and the optical axis of the lens can be displaced in parallel. It is the one. The outer dimensions of the lens holder 141 are manufactured to be slightly smaller than the inner dimensions of the holder 143, and the lens holder 141, which is fitted into the holder 143, has freedom in all directions. Lens holder 1
A bent portion 142 is integrally formed on the outer peripheral portion of the holder 41, and the lens holder 141 is left with a degree of freedom by friction with the inner wall of the holder 143 during the manufacturing process.
It is designed to be supported within 3. To adjust the parallax, attach the lens holder 141 to the holder 143, and then
The lens holder 141 and the holder 143 are fixed by an adhesive after the parallax is adjusted by applying the tilt eccentricity adjustment method and the parallel eccentricity adjustment method to the lens 40.

Further, although not intended to adjust the parallax, a projection light is added to the optical system so that the optical axis can be displaced in parallel by adding a single transparent flat plate having a uniform thickness. The structure of the light receiving portion of the triangulation type distance measuring device is disclosed in the above-mentioned Japanese Patent Laid-Open No. 59-162408. That is, as shown in FIG. 5 and FIG. 7, a transparent flat plate portion 122a having a uniform thickness and an optical axis Z− are provided behind the lens 6.
The optical axis adjusting plate 122 is provided which is composed of a rotary shaft portion 122b extending in a horizontal axis PP ′ direction orthogonal to Z ′. This is because a light ray that is obliquely incident on the surface of a transparent flat plate having a uniform thickness is refracted on the surface and transmitted through the transparent flat plate, and then is refracted again on the back surface and is emitted on the incident side. It utilizes the fact that it is parallel to the optical path and passes on different optical paths. Therefore, the optical path adjusting plate 1
22 is an axis P by rotating the rotating shaft portion 122b.
By rotating about -P ', the optical path of the light incident from the lens 106 can be vertically displaced. If this configuration is applied to the finder optical system, the same effect as that obtained by using the parallel decentering adjustment method of displacing the optical axis of one lens in the optical system in parallel can be obtained, and parallax can be adjusted.

[0009]

However, in the configuration of Japanese Patent Laid-Open No. 59-162408 shown in FIGS. 5 and 6, a lens (hereinafter, fixed) which is fixed in the lens barrel and whose position in the optical axis direction does not change is used. It is applied to a lens), and cannot be applied to a lens (hereinafter referred to as a movable lens) whose position in the optical axis direction changes in association with zooming. Therefore, if the objective lens group is composed of only movable lenses, there is a problem that this structure cannot be used.

Further, in the structure of the prior art shown in FIG. 8 as well, the lens holder 1 is provided with the engagement groove 135 fixed in the optical axis direction.
Since 31 is restricted in the optical axis direction, it can be applied to a fixed lens, but there is a problem that it cannot be applied when the objective lens group is composed of only movable lenses. Further, a space for mounting the adjusting screw 32 is required outside the space occupied by the lens holder 31, which causes a problem with respect to a demand for downsizing an apparatus using this optical system configuration.

Further, in the configuration of the prior art shown in FIG. 9, the parallax amount is adjusted in the process of adjusting the parallax by adjusting the angle and position of the optical axis of the lens 40 and adhesively fixing the lens holder 41 in the holder 43. In addition to the reading device, a means for holding the position of the lens holder 41 and a means for adjusting the lens 40 in accordance with the read parallax amount are required, which makes the adjustment jig large and the adjustment work complicated. was there.

Further, Japanese Patent Application Laid-Open No. 59-59, shown in FIGS.
In the configuration of Japanese Patent Laid-Open No. 162640/1989, in addition to the lens group, one transparent flat plate having a uniform thickness is required, and there is a problem that the number of parts increases.

The present invention has been made to solve such a problem, is applicable to a movable lens, and is a lens eccentricity adjusting device which can be easily adjusted by a simple structure. Another object of the present invention is to provide a parallax adjustment device using the same.

[0014]

In order to achieve the above object, the present invention provides a lens of an optical system, a fixed guide shaft for fitting and holding the lens or lens holding means, and the lens or lens holding means. With the eccentric pin attached,
A lens eccentricity adjusting device provided with a guide groove that engages with the eccentric pin, wherein the lens or lens holding means is fitted with the guide shaft and by engaging the eccentric pin with the guide groove. By being guided straight ahead and rotating the eccentric pin, the eccentricity can be adjusted in a direction substantially perpendicular to the straight line connecting the axis of the guide shaft and the center of the lens in a plane perpendicular to the optical axis. I am trying.

Further, according to the present invention, there is provided a parallax adjusting device for adjusting a parallax which is a difference between a photographing range and a visual field range by the photographing optical system and the finder optical system, wherein the parallax is adjusted by using the lens eccentricity adjusting device. The present invention provides a parallax adjustment device configured to perform.

[0016]

According to the above construction, since the first and second guide members supporting the lens extend in the optical axis direction, the movable lens can be decentered. In addition, since the adjustment can be performed by rotating the eccentric pin from the direction perpendicular to the optical axis, it is possible to easily adjust the front and rear lenses or lenses sandwiched by prisms and the like. Further, since the adjusting mechanism itself only adds the eccentric pin to the ordinary lens holding structure, the number of parts is small and the space occupied by the adjusting device can be made extremely small.

When this lens decentering adjusting device is used, it can be applied to an optical system in which an objective lens group is composed of only movable lenses, and a parallax adjusting device which is not bulky and requires a small number of parts can be simply adjusted. Obtainable.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a finder optical system of a camera will be described below with reference to the drawings. FIG. 1 is a perspective view showing the entire finder optical system according to the first embodiment of the present invention. The F direction in the figure is the front of the camera. The objective lens group 20 is composed of first and second lenses 1 and 5. In this embodiment, the first and second lenses 1, 5
Both are movable lenses that can move in the direction of the optical axis 22. Further, an erecting prism 21 composed of a roof prism 11 and a pentagonal prism 12 is arranged behind the objective lens group 20, and an eyepiece lens 13 is arranged behind it. In the present embodiment, the parallax is adjusted by performing a parallel eccentricity adjustment method of vertically displacing the optical axis of the second lens 5.

An arm 3 is integrally formed at one end of the first lens holder 2 for holding the first lens 1, and the arm 3
A fitting hole 3a provided at the tip of is fitted slidably into the guide shaft 9. Further, an engagement pin 4 is provided on the other end of the first lens holder 2, and the engagement pin 4 is provided on the optical axis 22.
Is slidably engaged with the engaging groove 10a of the guide member 10 arranged in parallel with the. As a result, the first lens 1 is kept perpendicular to the optical axis 22 and is supported so as to be able to move straight in the direction of the optical axis 22.

On the other hand, an arm 7 having a fitting hole 7a at its tip is integrally formed at one end of the second lens holder 6 for holding the second lens 5, and the fitting hole 7a slides on the guide shaft 9. It is movably fitted. An eccentric pin 8 is attached to the other end of the second lens holder 6, and the eccentric pin 8 is engaged with an engagement groove 10 a of the guide member 10. As a result, like the first lens 1, the second lens 5 is kept perpendicular to the optical axis and is supported so as to be able to move straight in the optical axis direction. Further, as will be described later, the eccentricity of the second lens 5 can be adjusted by rotating the eccentric pin 8.

Cam follower pins (not shown) are provided on the arms 3 and 7 of the first and second lens holders 2 and 6, respectively.
Are erected, and these cam follower pins are driven by a cam member (not shown), so that the first and second lens holders 2 and 6 (hence the first and second lenses 1 and 5) Moves along the optical axis 22, and zooming is performed.

2 and 3 are views showing a parallax adjusting device according to the first embodiment. That is, from FIG. 1, the guide shaft 9,
The configuration including the guide member 10, the second lens 5, the second lens holder 6, the arm 7, and the eccentric pin 8 is extracted and shown. As described above, the arm 7 integrally formed at one end of the second lens holder 6 holding the second lens 5 has the fitting hole 7a provided at the tip thereof fitted to the guide shaft 9. Thus, the second lens 5 is held perpendicular to the optical axis and supported so as to be able to move straight in the optical axis direction.
Here, the center O of the second lens 5 is the axis C of the guide shaft 9.
It has the freedom to rotate around. An eccentric pin 8 is attached to the other end of the lens holder 6. The eccentric pin 8 regulates the rotational position of the second lens 5 with respect to the axis C of the guide shaft 9 by engaging with the engagement groove 10a of the guide member 10. The eccentric pin 8 is press-fitted into a boss 14 formed integrally with the second lens holder 6. The eccentric pin 8 can rotate around the boss 14 as an axis when a force is applied by a tool or the like, but normally the rotational position thereof is held by friction and elastic force. In this case, boss 1
4 is located at a point displaced from the center of the eccentric pin 8. Therefore, when the eccentric pin 8 rotates, the position of the boss 14 is vertically displaced.

The rotational position of the eccentric pin 8 in FIGS. 2 and 3 is the neutral position, and the eccentricity of the second lens 5 can be adjusted by rotating the eccentric pin 8 from this state. That is, when the eccentric pin 8 is rotated in the direction A in FIG. 3, the outer shape of the eccentric pin 8 is restricted in the vertical direction by the engaging groove 10a of the guide member 10, so that the boss 14 is displaced upward. , The second lens 5 rotates in the D direction in FIG. Here, assuming a realistic numerical value, the distance between the axis C of the guide shaft 9 and the center O of the second lens 5 is 5 mm, and the correction amount of the position of the center O of the second lens 5 is 0. Assuming 0.1 mm, the second lens 5 around the axis C of the guide shaft 9
Since the rotation angle of the center O of the second lens 5 is about 1 °, the center O of the second lens 5 strictly moves on the circumference centered on the axis C of the guide shaft 9, but is substantially vertical. You can think that it will be displaced to. On the other hand, at the time of this eccentricity adjustment, the second lens holder 6 is tilted in a plane perpendicular to the optical axis, so that the eccentric pin 8 is tilted and engaged with the engagement groove 10a of the guide member 10. However, there is no problem in actual use in the above numerical order. When the eccentricity of the second lens 5 is actually adjusted, a driver or the like may be inserted into the notch 8a provided at the tip of the eccentric pin 8 to rotate the eccentric pin 8.

In the first embodiment, the optical axis of one lens is vertically displaced to adjust the parallax in the vertical direction. However, the guide shaft 9 and the guide member 10 are provided in the second lens holder 6. By disposing the arms 7 and the eccentric pins 8 on the upper and lower sides of the second lens holder 6 in accordance with the vertical arrangement, the parallax in the horizontal direction can be adjusted. Further, for each of the two lenses of the objective lens group, the guide shaft and the guide member, and accordingly the arm and the eccentric pin are arranged on the left and right for one lens holder and for the other lens holder in the vertical direction. If it is arranged at, the parallax can be adjusted in both vertical and horizontal directions.

FIGS. 4A to 4E show another embodiment of the present invention. The same components as those in the first embodiment are designated by the same reference numerals. The only difference from the first embodiment is the arrangement position of the guide shaft 9, the guide member 10, the arm 7 and the eccentric pin 8 with respect to the second lens holder 6, so only these components are shown. Even if the arrangement positions of these components are changed in this way, the second lens holder 6 can be displaced in the vertical direction within a plane perpendicular to the optical axis. It is desirable to select the optimum one from these arrangements according to the arrangement of the finder optical system in the camera body.

In the above embodiments, the two objective lenses are held by the lens holders, and the arms, the engaging pins and the bosses are formed integrally with the lens holder, but the lenses are made of plastic. In such a case, each arm, the engagement pin, and the boss may be integrally formed with the lens. Also,
Although the parallax adjusting device according to the above-described embodiment is applied to the movable lens, the guide shaft and the guide member are set to be short in the optical axis direction, and the lens holder is fixed in the optical axis direction. It can also be applied to fixed lenses.
The parallel decentering adjustment mechanism of the lens used in the parallax adjustment device according to the present invention is applied to the finder optical system, but it is not limited to this and can be applied to other optical systems.

[0027]

According to the invention of claim 1, the eccentric pin is added to the ordinary movable lens holding structure, and the eccentric pin is rotated from the direction perpendicular to the optical axis to decenter the lens. Since the adjustment can be performed, it is possible to easily adjust the movable lens sandwiched between other lenses and prisms at the front and back, and the adjustment device occupies by reducing the number of components compared to the case of using the conventional parallax adjustment device. The space can be made extremely small.

According to the second aspect of the present invention, it can be applied to an optical system in which the objective lens group is composed of only movable lenses.
It is possible to obtain a parallax adjusting device which is not bulky and can be easily adjusted with a small number of parts.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire finder optical system provided with a parallax adjusting device according to a first embodiment of the present invention.

FIG. 2 is a front view of the parallax adjustment device according to the first embodiment of the present invention.

FIG. 3 is a side view of the parallax adjustment device according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a parallax adjustment device according to another embodiment of the present invention.

FIG. 5 is a top view of a projection light type triangulation device provided with a conventional parallax adjustment device.

FIG. 6 is a cross-sectional view of a finder optical system provided with a parallax adjustment device by a tilt / eccentricity adjustment method in a conventional projection light type triangulation device.

FIG. 7 is a sectional view of an optical system to which a parallel decentering adjustment method using a conventional transparent flat plate is applied.

FIG. 8 is a front view of a parallax adjustment device according to a conventional parallel eccentricity adjustment method.

FIG. 9 is a perspective view of a parallax adjusting device using a conventional parallel eccentricity adjusting method and a tilt eccentricity adjusting method.

[Explanation of symbols]

 1 First Lens 2 First Lens Holder 3 Arm 3a Fitting Hole 4 Engaging Pin 5 Second Lens 6 Second Lens Holder 7 Arm 7a Fitting Hole 8 Eccentric Pin 9 Guide Shaft 10 Guide Member 10a Engagement Groove 11 Roof prism 12 Penta prism 13 Eyepiece 14 Boss 20 Objective lens group 21 Upright prism 22 Optical axis of optical system

Claims (2)

[Claims] 1. An optical system lens, a fixed guide shaft for fitting and holding the lens or lens holding means, an eccentric pin attached to the lens or lens holding means, and a guide groove for engaging the eccentric pin. The lens or lens holding means is linearly guided by fitting the guide shaft and engaging the eccentric pin with the guide groove, and rotates the eccentric pin to make the lens perpendicular to the optical axis. An eccentricity adjusting device for a lens, wherein the eccentricity can be adjusted in a direction substantially perpendicular to a straight line connecting the center of the guide shaft and the center of the lens in a plane. 2. A parallax adjusting device for adjusting a parallax which is a difference between a photographing range and a visual field range by a photographing optical system and a viewfinder optical system, wherein the parallax is adjusted by using the lens decentering adjusting device. The parallax adjustment device characterized by performing.