JP3832744B2 - Camera range finder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mirror having a window hole through which light incident from a distance measuring window passes, a frame mask plate in which a through hole through which light passes through the window hole of the mirror and a slit for bright frame display are formed. A half mirror that reflects the light passing through the frame mask plate toward the eyepiece and guides the light incident from the viewfinder window to the eyepiece, and external light is taken into the frame mask plate directly or via the mirror The present invention relates to a range finder of a camera having a daylighting window.
[0002]
[Prior art]
A range finder for a camera of the above type is well known. According to this type of rangefinder, the focus ring is rotated to match both subject images while looking through the eyepiece lens and visually observing the subject images incident through the distance measuring window and the viewfinder window. Can be combined. In addition, since the light is taken into the frame mask plate through the daylighting window, the bright frame can be clearly seen through the eyepiece.
[0003]
However, in the conventional rangefinder, when strong light enters the daylighting window, the light enters the eyepiece through the through hole of the frame mask plate, so that the display part of the subject image from the distance measuring window appears to shine abnormally. , The image becomes difficult to see and it is difficult to perform the focusing operation.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a range finder for a camera of the type described at the beginning, which eliminates the above-mentioned conventional drawbacks with a simple configuration.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the range finder of the camera of the type described at the beginning, the present invention guides light that has passed through the window hole of the mirror to the through hole of the frame mask plate and is introduced from the daylighting window. A range finder for a camera is proposed, which is provided with a cylindrical body for preventing light from entering the through hole of the frame mask plate.
[0006]
Further, in the range finder of the camera according to claim 1, the reflection of light is prevented or reflected on the peripheral portion of the window hole in the reflection surface of the mirror on the side facing the frame mask plate. It is advantageous to provide a light absorbing means to suppress (claim 2).
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0009]
FIG. 1 is an external perspective view of a camera, and FIG. 2 is a partial cross-sectional plan view showing an arrangement state of each element of a range finder of the camera. As shown in these drawings, a distance measuring window 1, a finder window 2, and a daylighting window 3 are arranged on the front side of the camera, respectively, and these windows are translucent glass fixed to the camera casing. Or it is comprised by resin etc. An eyepiece 4 is disposed on the back side of the camera, and a photographing lens 5 attached to a lens mount is disposed on the front side of the camera.
[0010]
As indicated by an arrow L1 in FIG. 2, the light incident from the distance measuring window 1 is reflected by the reflecting mirror 6, passes through the lens 7, then passes through the window hole 9 of the mirror 8, and passes through the window hole 9. The light passing therethrough passes through the through-hole 11 formed in the frame mask plate 10 and subsequently passes through the condenser lens 12 and then is reflected toward the eyepiece lens 4 by the half mirror 13 constituted by a prism. On the other hand, as indicated by the arrow L2, the light incident from the finder window 2 is guided to the eyepiece 4 through the half mirror 13.
[0011]
When looking into the eyepiece 4, the object enters through the distance measuring window 1 and passes through the reflecting mirror 6, the lens 7, the window hole 9 of the mirror 8, the through-hole 11 of the frame mask plate 10, the condenser lens 12 and the half mirror 13. The image can be viewed in the small area A shown in FIG. 3, and at the same time, the subject image that has entered the viewfinder window 2 and passed through the half mirror 13 can be viewed. Therefore, by rotating the focus ring 14 shown in FIG. 1, the double image on the eyepiece 4 can be matched and focusing can be performed.
[0012]
The frame mask plate 10 has a bright frame slit 15, and light incident from the outside through the daylighting window 3 is directly or directly reflected by the reflecting surface 16 of the mirror 8 and applied to the frame mask plate 10. The light passes through the slit 15 and is then guided to the eyepiece 4 through the condenser lens 12 and the half mirror 13. Thereby, when the eyepiece 4 is looked into, the bright frame F according to the angle of view of the lens can be clearly seen as shown in FIG.
[0013]
As described above, the range finder of the camera of this example includes the mirror 8 provided with the window hole 9 through which the light incident from the distance measuring window 1 passes, and the penetration through which the light passing through the window hole 9 of the mirror 8 passes. A frame mask plate 10 in which a hole 11 and a bright frame display slit 15 are formed, light reflected through the frame mask plate 10 is reflected toward the eyepiece lens 4, and light incident from the finder window 2 is reflected on the eyepiece lens 4. It has a half mirror 13 for guiding, and a daylighting window 3 for taking in external light directly to the frame mask plate 10 or via the mirror 8. Such a configuration is the same as a conventionally known range finder.
[0014]
According to the above-described range finder, external light is taken into the frame mask plate 10 from the daylighting window 3 and the light is allowed to pass through the slit 15 so that the bright frame F can be clearly seen through the eyepiece 4. Can do. However, as described above, in the conventional rangefinder, when strong light is incident on the daylighting window 3, the strong light is incident on the through hole 11 of the frame mask plate 10, and the small area shown in FIG. The area A was shining abnormally intensely, and it was inevitable that the subject image displayed here was difficult to see.
[0015]
Therefore, in the range finder of this example, as shown in FIG. 2, a cylindrical body 17 is provided to face the surface of the frame mask plate 10 facing the mirror 8. In the illustrated example, the cylindrical body 17 is formed in a cylindrical shape, a transparent glass 19 is fixed to the frame 18 that supports the frame mask plate 10, and the cylindrical body 17 penetrates the transparent glass 19, and The glass 19 is fixedly supported. The entrance-side opening 20 of the cylindrical body 17 faces the window hole 9 of the mirror 8, and the exit-side opening 21 of the cylindrical body 17 approaches the plate 10 in a state aligned with the through hole 11 of the frame mask plate 10. Located or abutting.
[0016]
By providing the cylindrical body 17 as described above, the light passing through the window hole 9 of the mirror 8 can be guided to the through hole 11 of the frame mask plate 10 through the cylindrical body 17 and taken in from the lighting window 3. The incident light can be prevented from entering the through hole 11 of the frame mask plate 10. Even if only a small part of the light entering from the daylighting window 3 is incident on the through hole 11, most of the light is blocked by the cylindrical body 17 from entering the through hole 11. Is done.
[0017]
With the configuration described above, even when strong light enters from the daylighting window 3, the light can be prevented from entering the through-hole 11 or effectively suppressed, and the light incident from the distance measuring window 1 can be suppressed. Since this can be reliably guided to the through hole 11 of the frame mask plate 10, it prevents a problem that the small-area area A viewed when looking into the eyepiece lens 4 is extremely bright and makes it difficult to see the subject image. it can. The light incident from the lighting window 3 can pass through the transparent glass 19 and enter the slit 15 of the frame mask plate 10.
[0018]
Further, as shown in FIGS. 2 and 4, light absorbing means 22 made of, for example, black paint or black tape is provided in the peripheral portion of the window hole 9 in the reflection surface 16 of the mirror 8 on the side facing the frame mask plate 10. The strong light incident from the lighting window 3 is prevented from entering the through hole 11 of the frame mask plate 10 by providing and preventing the reflection of the light in the peripheral portion of the window hole 9 or suppressing the reflection of the light. be able to. As a result, it is possible to prevent a problem that the small area region A is excessively shined and the subject image is difficult to see.
[0019]
Even if only one of the configurations of the cylindrical body 17 and the light absorbing means 22 described above is employed, it is possible to prevent the disadvantage that the subject image incident from the distance measuring window 1 is difficult to see. In addition, when these configurations are employed together, the effect can be further enhanced.
[0020]
【The invention's effect】
According to the present invention, it is possible to prevent a problem that the subject image from the distance measuring window becomes difficult to see even when strong light enters from the daylighting window.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a camera.
2 is a partial cross-sectional plan view of a range finder provided in the camera shown in FIG. 1. FIG.
FIG. 3 is a diagram showing a state when looking into an eyepiece lens.
FIG. 4 is a view showing a mirror provided with light absorbing means.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Distance measuring window 2 Finder window 3 Daylighting window 4 Eyepiece lens 8 Mirror 9 Window hole 10 Frame mask plate 11 Through hole 13 Half mirror 15 Slit 16 Reflecting surface 17 Cylindrical body F Bright frame 22 Light absorption means

Claims (2)

A mirror having a window hole through which light incident from the distance measuring window passes, a frame mask plate in which a through hole through which light passes through the window hole of the mirror and a slit for bright frame display are formed, and the frame mask plate A half mirror for reflecting the light passing through the eyepiece lens and guiding the light incident from the viewfinder window to the eyepiece lens, and a daylighting window for taking in external light directly to the frame mask plate or via the mirror In a range finder of a camera having
Provided with a cylindrical body for guiding the light passing through the window hole of the mirror to the through hole of the frame mask plate and preventing the light taken in from the daylighting window from entering the through hole of the frame mask plate A range finder for cameras.   2. The camera according to claim 1, further comprising a light absorbing unit that prevents light reflection or suppresses light reflection in a peripheral portion of the window hole on a reflection surface of the mirror facing the frame mask plate. Range finder.

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