JP3051995U - Focus adjustment device for large format film cameras - Google Patents

Abstract

(57) [Abstract] [Purpose] A focus confirmation device for a large format film camera [Configuration] A camera configured by a vertically movable reflector having a minimum required area within a limited space between a lens and a film.

Description

[Detailed description of the invention]

[0101]

[Industrial applications]

 The present invention is intended to enable accurate, quick and easy focusing at 4 × 5 inches, 8 × 10 inches, etc., which is common in view cameras, as well as at 35 mm single-lens reflex cameras.

[0092]

[Prior art]

 In the view camera, a ground glass is prepared in an image receiving unit via a lens, and focusing is performed on the ground glass.

After focusing, the user removes the ground glass or shifts it backward to attach a film holder with a film inserted to the part where the focus is coming in, and then take a picture. This is a prerequisite, inaccurate and wastes time.

[0093]

[Problems to be solved by the invention]

 To change the view camera to a single-lens reflex camera like a 35mm camera, it is easy to solve this problem by installing a reflector installed at a 45-degree angle between the film and the lens. There is no space between the films, and it is difficult to reflect the entire image.

[0056]

[Means for Solving the Problems]

 If you want to focus or check only a part of the image instead of seeing the entire image, it is advisable to prepare a slender reflector that matches the limited distance between the lens and the film surface.

If there is a reflecting mirror in front of the film, it will be a hindrance when taking a picture. Therefore, it is preferable to move the reflecting mirror upward or downward with a lever or the like to the outside of the image receiving unit after focusing.

007

[Action]

 Focusing can be performed while the film holder is attached to the camera body. When this is completed, the reflecting mirror is moved with a lever or the like, and the lid of the film holder is pulled to shoot.

[0098]

【Example】

 Embodiments will be described with reference to the drawings. In FIG. 1, the lens I is incorporated with two helicoid type screws and can be moved back and forth. Reference numeral 3 denotes a lens board that also serves as a bellows. 4 is a reflecting mirror having an angle of 45 degrees, 5 is a part for visualizing an image, and the visible image is passed through a reflecting mirror of 6 via an optical system assembly to a viewing window of 7. Reach.

The reflecting mirror and the visualized portion constituted by 4 and 5 are attached to a timing belt, a chain, a wire, and the like by a component 8, and are fixed on the pedestal 9 when descending downward. To come to the right position.

Various configurations from the reflector 4 to the visual window 7 can be considered by reducing the weight and size of the camera, mounting a measuring device, and the like. The reflector portion constituted by 4 and 5 is supported. Vertical movement by a timing belt shaft, chain, wire, etc., which moves up and down, is also conceivable.

The timing belt supporting the reflecting mirror portion constituted by 4 and 5 is attached to both sides of the camera outside the image connecting the lens and the film, and when the reflecting mirror portion is moved upward. , Which also goes out of the image.

[0122]

[Effect of the invention]

 Focusing is possible with the film holder set, and various measurements can be made using this device.

[Brief description of the drawings]

FIG. 2 is a cross-sectional view of a single-lens reflex camera using a large-format film having a movable reflecting mirror.

Claims (1)

[Utility model registration claims] 1. A reflecting mirror having an area within an allowable range within a limited space between a lens and a film is placed on the optical axis at 45 °.
An image direct-viewing device which is installed at an angle of degree, extends the image to a finder by reflection, and moves the 45-degree reflecting mirror from the front of the film when photographing.