JP3236571B2 - Camera finder device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera finder device.

[0002]

2. Description of the Related Art Conventionally, in a finder device of a camera, an apparatus for preventing the intrusion of dust has been disclosed in Japanese Utility Model Application Laid-Open No. 1-12.
The real image type finder device disclosed in Japanese Patent No. 5428 is a finder device using a Porro prism, and has a closed structure around an imaging surface of a finder optical system to prevent dust from entering. In the present finder device, dust does not enter around the image forming surface, and deterioration of the visibility of the finder can be prevented.

[0003]

However, the real image type finder disclosed in Japanese Utility Model Laid-Open Publication No. 1-125428 described above has a transparent protective member disposed in front of the finder image forming surface, and the protective member is attached to a Porro prism. And the space between the protection member including the image forming surface and the entrance surface of the Porro prism has a substantially closed structure. Although the finder device is provided with the support frame, it is necessary to further attach the transparent protective member to form a closed structure, which complicates the structure and is disadvantageous in cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has as its object to provide a camera finder device which can prevent dust from entering and has a simple structure.

[0005]

Camera viewfinder device according to claim 1, wherein the SUMMARY OF THE INVENTION The present invention comprises a plurality of optical elements, the double
At least adjacent optical elements among the number of optical elements
So as to bond between at least part of the finder optical path, and an elastic member <br/> tubular covering the optical path outer periphery, the outer periphery of the tubular elastic member with respect to the optical axis of the finder optical path Deforms almost vertically so that the viewfinder
Field size defining means for changing the field size .

According to a second aspect of the present invention, there is provided a camera viewfinder apparatus comprising:
And the field size defining means is located in the upper direction in the optical axis direction.
The elastic member can be deformed by pinching the specified position from outside.
And features .

[0007]

In the above construction, the visual field size defining means is provided.
However, a predetermined position on the outer periphery of the tubular elastic member is sandwiched from outside.
And deform it in a direction substantially perpendicular to the optical axis.
To change the viewfinder size .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a finder device according to one embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the finder device. The present finder device is a camera which can switch a normal view screen size of the finder to a panoramic view screen size corresponding to a horizontally long panoramic view size in accordance with a switching operation of a screen size switching operation means. It is a finder device.

The configuration of the present apparatus has objective lenses 1 and 2 as optical elements for taking in the subject light and forming an inverted inverted image of the subject on an image forming surface 3a, and the image forming surface 3a.
A porro prism 3, which is an erect image conversion means (optical element) for converting an image on the image forming surface 3a into an erect erect image with respect to the eyepiece lens 4, the eyepiece lens 4, and the vicinity of the image forming surface 3a. A normal field frame 10 for defining a finder field screen of a normal screen size provided, one of which is fixed in close contact with the periphery of the image forming surface 3a of the Porro prism 3 and the other in close contact with the outer periphery of the objective lens 2, respectively, and forms an image forming surface 3a. A tubular elastic member (made of an elastic means, for example, a rubber material) 5 which covers the outer peripheral portion of the optical path of the objective lens 2 and the porro prism 3 sandwiching the elastic member, the central portion being elastically deformable by bending. Member 5
And has arm portions 6a and 7a for deforming the elastic member 5 in the vertical (longitudinal) direction, and is rotatable about a support shaft 8 fixed to the apparatus main body. Regulatory levers 6, 7 as supported screen size defining means
And a switching operation member 9 serving as a screen size switching means, the driving portion 9a of which is inserted into the inclined driving grooves 6b, 7b of the regulating levers 6, 7.

The operating member 9 can be moved in a direction parallel to the finder optical axis O by a guide mechanism (not shown). Therefore, the movement of the operation member 9 causes the regulating levers 6, 7 to rotate, and the arms 6a, 7a to move in the vertical direction. The movement changes the width of the elastic member 5 in the vertical direction.

FIG. 3 shows a vertical cross section of the imaging surface when viewed from the direction of the finder optical axis O when the operation member 9 is moved forward and the arms 6a and 7a are opened. . In this state, the view screen size corresponding to the normal screen size regulated by the view frame 10 is set as the view screen size.
A (opening size A × B). On the other hand, FIG. 4 shows a vertical cross section of the imaging surface when the operation member 9 is moved backward, the arms 6a and 7a are closed, and the elastic member 5 is pressed. In this state, the screen size is a panoramic visual field screen GC (opening dimension C × D) corresponding to a panoramic screen size whose top and bottom (vertical direction) is regulated by the elastic member 5.

In the finder device of the present embodiment configured as described above, the subject light taken in through the objective lenses 1 and 2 forms an inverted inverted image on the imaging surface 3a of the Porro prism 3. Image. Then, the inverted image is observed from the eyepiece 4 as an erect image via the Porro prism 3.

Now, it is assumed that the photographing screen has the normal screen size. Therefore, when switching the screen size from the normal screen size to the panoramic screen size, the switching operation member 9 of the finder device is moved forward. Due to the movement, the arms 6a and 7a of the regulating levers 6 and 7 act to press the elastic member 5, and from the state of FIG. 3 to the narrow panoramic view screen GC corresponding to the panoramic screen size narrowed as shown in FIG. Change. Further, when returning to the normal screen GA again, the operating member 9 is retracted, the regulating levers 6 and 7 are opened, and the visual field frame is set to the visual field screen GA corresponding to the normal screen size.
(See FIG. 3).

As described above, in the finder device according to the present embodiment, the size of the field frame corresponding to the size of the photographing screen can be set by the elastic member 5, but the image forming surface 3a of the subject image is further formed. Since the space between the lens and the objective lens 2 is sealed by the elastic member 5, intrusion of dust and the like from the outside is prevented. Therefore, the appearance is not degraded due to intrusion of dust or the like.

The elastic member 5 blocks the optical path between the objective lens 2 and the Porro prism 3 from the outside, but the above-mentioned blocking function is maintained even if the distance between the optical paths expands and contracts. That is, the elastic member 5, flexures are enabled seen in the optical axis direction of the optical path.

[0016]

As described above, according to the present invention,
The outer periphery of the tubular elastic member is aligned with the optical axis of the finder optical path.
Deformation in a substantially vertical direction,
You can set the size of the field of view corresponding to the size
At the same time , the outer periphery of a part of the optical path is covered by the tubular elastic member, so that intrusion of dust into the inside of the optical path can be easily prevented. Furthermore, since the covering member is the above-mentioned tubular elastic member, it can cope with a state where the outer peripheral portion of the optical path changes.

[Brief description of the drawings]

FIG. 1 is a perspective view of a finder device showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the finder device of FIG. 1;

FIG. 3 is a cross-sectional view of an image forming surface portion of the finder device of FIG. 1 and shows a normal visual field screen corresponding to a normal photographing screen size.

FIG. 4 is a cross-sectional view of an image forming plane of the finder device of FIG. 1, showing a panoramic visual field screen corresponding to a panoramic photographing screen size.

[Explanation of symbols]

1, 2 ... Objective lens (optical element) 3 ... Porro prism (erect image conversion element, optical element) 5 ... Tubular elastic member (tubular elastic means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 13/00-13/28

Claims (2)

(57) [Claims] A plurality of optical elements and at least an adjacent optical element among the plurality of optical elements;
A tubular elastic member covering the outer periphery of the optical path in at least a part of the optical path of the finder so as to couple between the child elements, and an outer periphery of the tubular elastic member being substantially perpendicular to an optical axis of the finder optical path. In the direction of the viewfinder
A viewfinder device for a camera, comprising: a field-of-view size defining means for changing a size . 2. The method according to claim 1, wherein the visual field size defining means is provided in the optical axis direction.
Deformation by pinching a predetermined position of the above elastic member from outside
Camera viewfinder device according to claim 1, characterized in that cause.