JPH0743784A - Finder device with adjustment mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] When assembling and adjusting the viewfinder system, adjustment of diopter and parallax can be centrally performed at one place to facilitate adjustment and prevent dust from entering during adjustment. The purpose is to A holding member for temporarily holding an objective lens on the object side of the finder optical system in a direction perpendicular to the optical axis by elastic force and a holding frame for holding the holding member movably along the optical axis. After adjusting the diopter by moving the holding member in the optical axis direction, the objective lens is moved in the direction perpendicular to the optical axis to adjust the parallax.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder adjusting mechanism for adjusting diopter and parallax in a camera finder manufacturing process.

[0002]

2. Description of the Related Art Adjustment of a viewfinder of a camera is performed to correct an optical deviation from a design center caused by a stacking of manufacturing errors of each component forming the viewfinder. It is roughly divided into diopter adjustment for adjustment and parallax adjustment for matching the shooting angle of view of the actual festival and the angle of view of the viewfinder at a predetermined distance. Conventionally, the finder diopter is corrected by moving the objective lens or the eyepiece lens in the optical axis direction, and it is necessary to adjust the finder diopter to be within a predetermined standard value. Especially in the viewfinder of a camera with a high-magnification zoom ratio (2x or more), the diopter greatly changes between telephoto and wide-angle, so the diopter is kept within the specified standard at each zoom position during the manufacturing process. Is important.

On the other hand, parallax adjustment can be corrected by various optical parts constituting the finder optical system. For example, considering the real image finder, (1)
Move the field frame existing on the focal plane, (2) change the top of the Porro prism, (3) change the top of the mirror,
(4) The objective lens is decentered vertically or horizontally.
Etc., various methods have been considered and implemented.

[0004]

However, the diopter adjustment and the parallax adjustment of the viewfinder are originally due to their nature.
It is desirable to make adjustments while the finder device is attached to the camera body, but in the above-mentioned conventional example, each adjustment is dispersed in different places, and the adjustments are also subtle, complicated, and require advanced coordination. It was a thing.

When the causes of this adjustment problem are sorted out, the following items are listed. (1) In order to reduce the size of the product, it is not possible to secure a sufficient space required for adjustment. (2) The adjustment method itself is complicated (mirror top adjustment, prism top adjustment, etc.) and must be performed with a special jig. (3) After the adjustment, it is necessary to perform the bonding in order to maintain the state, but at this time, there is a possibility that the position may be displaced from the adjusted position before the fixing. Therefore, the efficiency was poor because the process could not proceed to the next process until the bonding process was completed. (4) Since the part to be adjusted is located inside the viewfinder, dust is likely to adhere to it during the adjustment process, making it difficult to control the process to prevent the viewfinder image from becoming unnatural. (5) Since the adjustment points are at different positions, the work efficiency during adjustment was poor. (6) As the configuration of the optical system becomes complicated, the adjustment component or the adjustment tool may become extremely difficult.

[0006]

A first holding member for temporarily holding an objective lens movably in a direction perpendicular to an optical axis, and the first holding member.
An adjusting mechanism having a second holding member for temporarily holding the objective lens temporarily held by the holding member so as to be movable in the optical axis direction (front-back direction) is provided, and the diopter and parallax adjustment are included in the assembly adjustment of the finder device. The position of the objective lens is adjusted.

[0007]

1 to 3 show a first embodiment of the present invention.

1A and 1B show the overall arrangement of the finder optical system according to the present invention. FIG. 1A shows the arrangement of the finder optical system on the telephoto side, and FIG. 1B shows the same wide-angle side. The layout of the optical system of the viewfinder of FIG. It is assumed that the taking lens of the camera is arranged apart from the viewfinder.

Reference numeral 1 denotes an objective lens of the first group, 2a and 2b are second objective lenses of the second group that move integrally, and are provided by means (not shown) in conjunction with the operation of the zoom lens of the photographing system. The lenses of the first and second groups are moved to obtain a predetermined zoom magnification.

Reference numeral 3 is a plane mirror which reflects on the surface, and 4 is a convex flat field lens, and the plane side is an image forming plane of a finder image. Reference numeral 5 denotes a three-sided reflection Porro prism for inverting an object image, 5a and 5b are roof surfaces, and 6 is an eyepiece lens. The trouble is that the plane mirror 3 is the first of the so-called Porro prisms 5.
Equivalent to the reflective surface of.

Next, the structure of this embodiment will be described in detail with reference to FIGS.

FIG. 2 is a front view of the objective lens 1 of the first group, and FIG. 3 is a sectional view from the side, showing a configuration for adjusting the diopter and parallax of the finder.

In the figure, 1 is the objective lens of the first group shown in FIG. 1, and 1a is the lens action surface, 1b and 1c.
Is a lens receiving surface (flange) formed of a flat surface. Further, notches 1a are formed at the four corners of the lens, and these parts function as a gripping part of the lens during adjustment and hold the lens permanently after the adjustment, and thus function as an adhesive injection part.

Reference numeral 7 is a holding member for holding the objective lens 1, which is provided with a pair of spring holding arcs 7b, and which is a lens receiving portion 7 formed by the plane of the objective lens 1 inserted from the side.
The objective lens 1 is pressed against the rear wall of the holding member 1 by a pressing arc 7b from the front side of the lens to temporarily hold it. In addition, the rear wall is provided with an opening sufficient for passing a light beam. Reference numeral 8 denotes a holding frame that holds the holding member 7 so as to be movable along the optical axis. Both side surfaces of the holding member 7 are received by the four protruding portions 8a provided on the holding frame 8 to prevent the holding member 7 from sliding during sliding. The upper and lower surfaces are configured so that the holding member 7 and the holding frame 8 are fitted to each other so as to reduce friction. That is, the holding member 7 is configured to be movable in the front-back direction of the optical axis of the objective lens 1 with respect to the holding frame 8.

Temporary locking of the holding member 7 to the holding frame 8 is performed by contacting the inner wall surface of the holding frame 8 with an elastic portion 7c formed integrally with the holding member 7. The specific adjustment in the optical axis direction is performed by the eccentric pin 9a of the eccentric jig 9 shown in FIG.
Holding frame, holding member 7 through a hole formed in the upper part of 8
It is carried out by inserting it into the long hole 7b perpendicular to the optical axis and rotating it. After the adjustment, the holding member 7 and the holding frame 8 are adhesively fixed.

Unfortunately, 10 is a guide bar, which holds both objective lenses through the fitting hole 8b of the holding frame 8 of the first group and the fitting hole 11a of the holding member 11 of the second group. There is.

In order to regulate the movement of both objective lenses when the zoom is interlocked, the first and second objective lenses are attracted by a tension spring (not shown) attached to a spring hook 8c.
It is assumed that the engagement bins shown in d and 11b are brought into contact with a cam surface (not shown). Since this point is not directly related to the present invention, its explanation is omitted.

Next, the specific adjustment of the finder in the above configuration will be described. First, in the adjustment, it is necessary to adjust the diopter and the parallax at the photographing common distance, but here, for convenience, the common distance is 3 m.

First, the diopter correction is performed in the state of FIG. 1A on the telephoto side where the sensitivity is high, and the eccentric jig 9 shown in FIG. By moving it in the direction of the optical axis against the frictional force of the elastic portion 7c, and adjusting it so that the image at a predetermined distance (3 m) is the clearest when looking through the eyepiece, and hold it in this state The member 7 and the holding frame 8 are bonded so as to be integrated.

Next, the parallax adjustment is an adjustment for matching the angles of view of the photographing optical system and the finder optical system with respect to an object at a predetermined distance. This is performed by the following method. First, the view angle range of the photographing system at a predetermined distance (in this case, 3 m) and a predetermined focus (for example, telephoto 115 mm) is shown in the chart above the object distance, and the viewfinder of the viewfinder is aligned so as to match this view angle. While looking through the eyepiece, the objective lens 1 is grasped with tweezers or the like through the notch 1a, moved up and down, left and right to be adjusted, and then fixed by adhesion.

In the above-mentioned embodiment, the eccentric bin is used for the diopter adjustment from the upper part, but the present invention is not limited to this method. For example, the holding member 7 may be threaded. The holding member 7 and the holding frame 8 are urged by a tension spring so as to attract each other, and a screw is tightened from the side to separate the two holding members from the back side of the screw to regulate the relative position, or a spacer is placed between the holding members. It may be inserted so that both parts are kept at a constant distance.

Further, as a merit of the above structure, it is effective when the objective lens has no margin in the vertical direction as shown in the embodiment, and the outer shape of the objective lens cut in the vertical direction has an oval shape. However, the objective lens can be easily moved back and forth along the optical axis, and the adjustment is extremely easy. Figure 4
And FIG. 5 shows a second embodiment of the present invention. 4 is shown in FIG.
FIG. 6 is a view of the first group of objective lenses as seen from the front,
FIG. 5 is a sectional view of the objective lens shown in FIG. 4 taken along the center line indicated by the alternate long and short dash line.

In the figure, 21 is an objective lens (corresponding to 1 in FIG. 1), 21a is a lens working surface, and 21b and 21c are jig mounting portions for gripping the lens at the time of parallax adjustment. Reference numeral 22 is a holding member for the objective lens corresponding to 7 of the first embodiment, 22a is a flat lens receiving portion formed in a ring shape, and 22b is the objective lens 2 inserted from below.
1 is a pair of lens pressing arcs formed so as to be positioned on the front side of the lens for temporarily fixing 1 with a spring load. Reference numeral 23 denotes a holding frame that holds the holding member 22, and is locked together with the light press-fitting portion 22c formed in the holding member 22 in the fitting hole 23a.

The contact surfaces of the holding member 22 and the holding frame 23 are tapered surfaces 22d and 23b as shown in FIG. 5, and the holding member 22 is recessed in the holding frame 23.
The object lens 21 attached to the holding member 22 can be moved in the front-rear direction with respect to the optical axis by gripping b and pressing it against the tapered surface and rotating it. In the above embodiment, the holding member and the facing surface of the holding member are formed with tapered surfaces of the same shape at every 120 ° so that the three surfaces come into contact with each other. It is formed to be stable even when the fitting length is short and the pressing is not uniform. Further, in the above-described embodiment, the holding member 22 and the holding frame 23 are joined by light press-fitting, but the temporary fixing method is not limited to this method, and the ring of the holding member 22 is set as shown in the first embodiment. It is also possible to cut a part of this and hold it using this elastic force.

On the other hand, the other part of the holding frame will be described.
Similarly to the first embodiment, 23c is a hole for fitting into a guide bar (not shown), and 23d is a cam pin that comes into contact with a cam for causing the objective lens to make a predetermined movement. Reference numeral 23e denotes a spring hook portion 23f for attracting the first and second groups and for applying a tension coil spring for bringing them into contact with a cam (not shown). The spring hook portion 23f is an anti-vibration dowel for preventing rotation of the holding frame.

In the above-mentioned construction, by adjusting the finder concretely, first, the diopter is adjusted by grasping the concave portion 22e of the holding member 22 with a jig and rotating it while pressing it against the holding frame 23 so that the objective lens 21 is moved to the optical axis. On the other hand, it is moved in the front-back direction to adjust the position to the best focus at a predetermined distance.

Next, for the parallax adjustment, the jig mounting portions 21b and 21c of the objective lens are grasped and vertically moved with respect to the holding member 22.
It is moved to the left and right, and adjustment is performed so as to match the angle of view of the imaging system at a predetermined focal length placed at a predetermined distance.

After each adjustment, they are fixed by adhesion so that the position does not move.

The merit of the second embodiment is that both the diopter and parallax adjustments can be made from the front side of the objective lens. The point is that it can be adjusted on the part that is outside the system. For this reason, it is possible to take the finder adjustment process to the final stage after the main body is attached, and it is possible to minimize the intrusion of dust. In particular, the above configuration is effective when the objective lens can be made circular, and is not only easy to adjust without using a special jig, but also small in size and has a small number of components,
There are many advantages such as the ability to adjust at an extremely low cost.

[0030]

As described above, the following effects can be obtained by providing the same objective lens group for both adjustment of diopter and parallax. (1) The adjustment position can be located on the most front side of the first group, and a sufficient adjustment space can be secured on the front side and the upper side of the lens, which facilitates the adjustment. That is, the adjustment unit of the product itself can be extremely miniaturized. Therefore, there is no difficulty in adjusting according to the miniaturization. (2) The adjustment method can be performed in two directions, ie, a horizontal direction and a vertical direction with respect to the optical axis, and independent adjustments can be easily performed. (3) After adjustment, each part is fixed by adhering to maintain the adjusted state. However, as described above, the adhering surface can be the outermost part, so that the position is such that it is easy to adhere, and the shape is also in the normal position. Since it can be bonded, it can be bonded easily and accurately. (4) Since the adjustment part can be arranged on the outermost side, the adjustment can be made in the completed viewfinder unit. Therefore, it is possible to minimize the intrusion of dust at the time of adjustment, which is the most problematic problem in the finder assembled state. (5) Since the adjustment points are concentrated in one place, the adjustment work is easy and simultaneous adjustment is possible depending on the tool setting method in the process. (6) The adjustment mechanism can be constructed at low cost because there are few components related to the adjustment.

[Brief description of drawings]

FIG. 1 is an optical sectional view of a finder optical system according to an embodiment of the present invention.

FIG. 2 is a partial front view of the first embodiment.

FIG. 3 is a partial cross-sectional view of the first embodiment.

FIG. 4 is a partial front view of the second embodiment.

FIG. 5 is a partial cross-sectional view of the second embodiment.

[Explanation of symbols]

 1 Objective Lens 7 Holding Member 8 Holding Frame 9 Eccentric Jig 10 Guide Bar 11 Second Group Holding Member 21 Objective Lens 22 Holding Member 23 Holding Frame

Claims (5)

[Claims] 1. A finder optical system having an objective lens and other optical elements, and lens holding means capable of adjusting the position of the same objective lens in an optical axis direction and a direction perpendicular to the optical axis. And a lens holding means is fixed to adjust the diopter and parallax of the finder optical type. 2. A finder optical system having an objective lens and other optical elements, a first holding member for temporarily holding the objective lens so as to be movable in a direction perpendicular to the optical axis, and temporarily held by the first holding member. A second holding means for temporarily holding the objective lens so as to be movable in the optical axis direction, and after the adjustment, the objective lens,
A finder device having an adjusting mechanism, characterized in that the first and second holding members are respectively fixed. 3. The first holding member temporarily holds the objective lens by applying an elastic force in the optical axis direction to the objective lens, and an optical member is provided between the first holding member and the second holding member. A finder device with an adjusting mechanism according to claim 2, wherein a vertical coupling force is applied to the shaft, and the first holding member is fitted to the second holding member. 4. The finder device having the adjusting mechanism according to claim 2, wherein the objective lens is the lens closest to the object side among the plurality of lenses which move relatively in the finder optical system. 5. A finder apparatus having an adjusting mechanism according to claim 2, wherein the movement of the objective lens in a direction perpendicular to the optical axis is performed for adjusting the parallax with respect to the taking lens.