JPH04215632A - Finder device for camera - Google Patents

Abstract

PURPOSE:To obtain a small-sized and lightweight finder device for a camera displaying the photographing information. CONSTITUTION:A finder device is constituted of a prism 8 projecting the image forming light of a focusing screen 6 to a mirror frame 9, the mirror frame 9 with a roof section reflecting the projected light toward a mirror 10, the mirror 10 projecting the reflected light toward the position of an ocular lens 11, a transmission type LCD 31 displaying the photographed information, display light reflecting mirrors 34, 35 reflecting the display light toward the roof section of the mirror frame 9, and the ocular lens 11.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder device, and more particularly to a display device for displaying information for photographing in a finder device equipped with a prism and a roof mirror.

0002

2. Description of the Related Art In recent years, single-lens reflex cameras have become more compact and lightweight, and in order to cope with this trend, finder devices have also been made smaller. Many proposals have also been made regarding such finders having means for displaying finder information, which is information for photographing.

For example, a device for displaying information on the finder optical system of a single-lens reflex camera disclosed in Japanese Patent Publication No. 47-17862 is a single-lens reflex camera with an erect image using a triangular prism and a roof-shaped prism (roof mirror). This is a finder for use in a computer, in which the first reflecting surface of a triangular prism is a semi-transparent mirror, and information in the finder is displayed in that part.

[0004] Furthermore, a finder for a single-lens reflex camera disclosed in Japanese Utility Model Application Publication No. 53-6230 has an integral structure of a triangular prism and a roof-shaped prism (roof mirror), and a transparent portion is provided on a part of the reflective surface of the prism. The display light beam for information in the finder is made to enter from there.

[0005]

However, the optical system of the finder disclosed in Japanese Patent Publication No. 47-17862 is constructed so that the light beam for displaying information in the finder also passes through the triangular prism section. There was a problem in that the area of the ejection part of the triangular prism became large, the prism itself became large, and as a result, the finder device became large.

[0006] Furthermore, the finder disclosed in Japanese Utility Model Application No. 53-6230 has a problem in that the external size of the camera becomes large because the display element and the display optical path for the information in the finder are arranged at the top of the finder device. was there.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small and lightweight finder device by reducing the size of the prism to the minimum necessary size by creating a structure in which the display light beam does not pass through the prism in order to solve the above-mentioned problems. be.

[0008]

[Means for Solving the Problems] A finder device for a camera according to the present invention includes: an entrance surface into which object light is incident from a photographing optical system; a first reflection surface that reflects the incident light diagonally downward and backward; A prism having a second reflecting surface that reflects the light reflected from the first reflecting surface diagonally upward and backward, and an exit surface that emits the reflected light from the second reflecting surface backward, and light from the exit surface of the prism. a roof mirror that receives the light from the roof, a reflector that reflects the reflected light from the roof mirror backward, an eyepiece optical system that enables the observation of the reflected light from the reflector, and a roof mirror located behind the prism that displays information for photographing. and a display optical system that emits the display of the display means toward the roof mirror.

[0009]

[Operation] In the above-mentioned finder device, display light is emitted directly toward the roof mirror, and the displayed content is observed through the eyepiece optical system.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on embodiments shown in the drawings. FIG. 1 is a longitudinal cross-sectional view of the optical system of a single-lens reflex camera incorporating a finder device according to a first embodiment of the present invention. In addition, FIG. 2 is a sectional view taken along line DD in FIG.
FIG. 3 is a perspective view of the main parts of the optical system.

As shown in FIG. 1, the optical system includes a photographic lens 4, a main mirror 5, a shutter device 15,
It is composed of a strobe unit 23 and a finder device. The finder device is composed of first and second optical blocks, a focusing screen 6, a condenser lens 7, and an eyepiece lens 11 and a light receiving element 12, which are eyepiece optical systems. The focusing screen 6 and condenser lens 7 are supported by a mounting frame 21 and are disposed above the main mirror 5. Also,
The eyepiece lens 11 is supported via a lens holder 3, and is arranged in parallel behind the second optical block in parallel with a light receiving element 12 including a condenser lens.

[0012] The first optical block includes a camera body 1
Prism 8 supported on a mounting table 22 fixed to
The second optical block also has a mounting table 22.
It consists of a mirror frame 9 that is supported above and forms a roof mirror, a mirror 10 that is a reflecting plate, and an information display section in the finder that displays information for photographing. Further, the information display section in the finder includes a backlight LED 32 and a light guide prism 33 supported by the camera outer cover 2 at the upper part of the mirror frame 9, and a display element that is a means for displaying information for photographing. It is composed of a type LCD 31 and first and second display light reflecting mirrors 34 and 35, which are display optical systems.

The prism 8 has a light incident surface 8a located opposite to the condenser lens 7, and further has a first reflective surface 8b provided with a reflective coating to reflect the incident light L2 obliquely backward. and a second reflecting surface 8c which is a corresponding surface of the incident surface 8a and reflects the reflected light L3 from the first reflecting surface 8b upward and diagonally backward;
Each of them is provided with an exit surface 8d for injecting the light beam 4 into the mirror frame 9 of the second optical block at the next stage.

The mirror frame 9 is a roof-shaped hollow body and has an entrance opening 9d that faces the exit surface 8d at an angle, takes in the reflected light L4, and further emits the reflected light L4. For the purpose of reflection, a third reflecting surface 9a and a fourth reflecting surface 9b of the roof part, which is the inner surface of a roof-shaped structure abutted against each other at right angles and coated with aluminum, as shown in FIG.
It has Furthermore, to prevent unnecessary light from being reflected,
A slope 9c which is a non-reverse slope in which a stepped V-shaped groove with a predetermined angle is formed, an opening 9g for passing the light from the LCD 31, and a receiving part 9 for positioning the mirror 10.
f are provided respectively.

The reflected light L4, which is the light incident on the mirror frame 9, is reflected by the third reflective surface 9a and the fourth reflective surface 9b, and is reflected by the opposing reflective surface, that is, the fourth reflective surface.
It is assumed that the light is incident on the reflective surface 9b or the third reflective surface 9a, and is incident on the diagonally downward mirror 10 as reflected light L5, respectively.

Further, the mirror 10 has a fifth reflective surface 10a, and is in contact with the positioning receiving portion 9f of the mirror frame 9, and is adhesively fixed while entering the roof portion of the mirror frame 9. It will be arranged as follows. The reflected light L5 is reflected by the fifth reflective surface 10a, and the reflected light L6 is emitted toward the eyepiece 11 and the light receiving element 12, which are arranged on the rear opening 9e side of the mirror frame 9.

The LCD 31 of the finder information display section is as follows:
This is a transmissive LCD that displays information in the finder, and is disposed on the back surface 9h of the mirror frame 9 behind the prism 8. Its position is a position facing the opening 9g on the slope 9c (see FIG. 3). Furthermore, a light guiding prism 3 is provided for introducing a backlight to the transmissive LCD 31 from the outside.
3, the LCD 31 is supported by the camera outer cover 2;
is located at the rear of the Furthermore, an LED 32 is disposed between the light guiding prism 33 and the strobe unit 23 for use as a backlight during night photography.

Display light H incident through the LCD 31
1 passes through the opening 9g and advances obliquely downward within the mirror frame 9 in a state substantially parallel to the exit surface 8d of the prism 8. The display light H1 is reflected by a first display light reflecting mirror 34 fixed to the mounting table 22, and the display light H2, which is the reflected light, is also fixed to the mounting table 22 and is reflected by the first display light reflection mirror 34, which is fixed to the mounting table 22. The light is reflected by a second display light reflecting mirror 35 facing the light reflecting mirror 34.

The display light H3, which is the reflected light, is equivalent to the light emitted from the downwardly extending surface of the exit surface 8d of the prism 8, and similarly to the reflected light L4, It is reflected by the reflecting surfaces 9a and 9b as display light H4. Similarly, the display light H4 is also applied to the fifth mirror 10.
It is assumed that the light is reflected by the reflective surface 10a and enters the eyepiece lens 11 as display light H5.

FIG. 4 is an exploded perspective view of the mounting frame 21 that supports the focusing screen 6, etc., and the mounting table 22 that supports the first and second optical blocks. After the members are installed, they are connected using screws or the like. As shown in this figure, the mounting table 22 has a support surface 22a for the prism 8 and an opening 22d, and also has a mounting surface 22e for the first display light reflecting mirror 34 and a second display light reflecting mirror 34 in the center thereof.
It has a mounting surface 22f for the display light reflecting mirror 35. Furthermore, it has a mounting surface 22c of the mirror frame 9 and a positioning recess 22b into which a positioning projection 9i (see FIG. 3) of the mirror frame 9 is fitted and bonded.

Next, the optical path transmission path of the finder device of this embodiment constructed as described above will be explained with reference to FIG. First, object light L0 is taken in through the photographing lens 4 along the optical axis O, and the finder object light reflected by the main mirror 5 enters the focusing screen 6 as incident light L2, and the finder object image is reflected by the main mirror 5. imaged as. During photographing, the main mirror 5 is retracted to the retracted position, and an image is formed on the surface of the film 16 via the shutter device 15 as photographic light L1.

The image forming light for the finder enters the entrance surface 8a of the prism 8 through the condenser lens 7 as incident light L2. Then, the reflected light L4 is reflected by the first and second reflecting surfaces 8b and 8c and enters the mirror frame 9. Further, the light is reflected by the third and fourth reflecting surfaces 9a and 9b of the roof portion and the fifth reflecting surface 10a of the mirror 10, respectively, and is emitted as reflected light L5 in the direction where the eyepiece lens 11 and the light receiving element 12 are located. Then, the finder subject image is observed at the eyepoint P. At the same time, photometry is performed by the light receiving element 12.

On the other hand, the display light H1 of photographing information from the LCD 31 is reflected by the first and second display light reflection mirrors 34 and 35 and enters the third and fourth reflection surfaces 9a and 9b of the roof section, and the reflected light is H4 is further reflected by the mirror 10, and the display light H
5 enters the eyepiece lens 11. In FIG. 1, the incident light L12 is incident light from the upper and lower outer frame portions of the finder subject, and the display light H5 is located below the corresponding reflected light L16. Therefore, the display of photographic information is positioned below the finder subject image on the eye point P.

FIG. 5 is a diagram showing the display image of the finder, in which a finder subject image is displayed in the image frame 37, and finder information is displayed in the display section 38 below it. Note that within the image frame 37, an autofocus frame 37a and a spot photometry range frame 37b are shown. The display unit 38 also displays shooting information such as a focus display 38a, a strobe light emission display 38b, a shutter speed display 38c, an aperture value display 38d, and an exposure compensation display 3.
8e etc. are displayed.

In this embodiment, since the display light does not pass through the prism 8 as described above, the exit surface 8 of the prism 8
The size of d can be reduced to the necessary minimum. Furthermore, the optical path of the display light is arranged behind the prism 8, and the optical path of the display light is arranged behind the prism 8.
Since the light is reflected in a folded state below the frame 9, the space in the finder section can be used effectively. Then, the LCD 31 which is a display element is mirrored.
It can be placed on the back surface 9h of the slope 9c other than the roof surface of the frame 9, and the strobe unit 23 can be conveniently placed above or in front of the prism 8 while suppressing the height of the finder section.

Furthermore, there is an outer cover 2 of the camera just above the LCD 31, so that external light for display light can be easily taken in. In addition, by arranging the backlight LED 32 near it, only when the outside world is dark,
Energy saving can be achieved by lighting up the LED 32.

[0027] In this embodiment, the first and second
The display light reflecting mirrors 34 and 35 are adhered to the mounting surfaces 22e and 22f on the slopes of the mounting table 22, and by using a member of an integral structure having the surface portions of the mirrors 34 and 35, the mirror frame is Similar to the roof surface of 9, the surface portion may be formed into a mirror surface by applying aluminum vapor deposition after plastic molding, and the unit may be fixed at a predetermined position on the mounting table 22.

FIG. 6 shows a longitudinal sectional view of the optical system of a single-lens reflex camera incorporating a finder device showing a second embodiment of the present invention. The present embodiment is characterized in that the display means is disposed on a mounting table below the mirror frame. The other optical systems are the same as those of the first embodiment.

That is, as shown in FIG. 6, the optical system includes a photographing lens 4, a main mirror 5, and a shutter device 1.
5 and a finder device. As in the first embodiment, this finder device includes a first optical block, a second optical block, a focusing screen 6, a condenser lens 7, and further includes:
It is composed of an eyepiece lens 11 and a light receiving element 12, which are an eyepiece optical system.

The first optical block is composed of a prism 8 supported on a mounting table 42 fixed to the camera body 1, and the second optical block is also composed of a prism 8 supported on a mounting table 42 fixed to the camera body 1.
It is comprised of a mirror frame 49 supported on a mounting table 42 and forming a roof mirror, a mirror 10 which is a reflecting plate, and an information display section in the finder that displays information for photographing.

The prism 8 and mirror 10 are
It has the same structure as the example. And the mirror above
The frame 49 is also a roof-shaped hollow body and has the above-mentioned injection surface 8d.
It has an entrance opening 49d facing the prism 8, takes in the reflected light L4 from the prism 8, and further reflects the reflected light L4.
9a and a fourth reflective surface 49b. and,
A slope 49c that is a non-reverse slope for preventing reflection of unnecessary light, a receiving part 49f for positioning the mirror 10, and a part of the optical system for displaying information in the finder formed below the slope 49c, aluminum vapor deposition. A second display light reflecting mirror 49g is provided.

Note that in the mirror frame 49, the prism 8
The reflected light L4 is reflected by the third reflective surface 49a and the fourth reflective surface 49b, and is reflected by the opposing reflective surfaces facing each other, that is, the fourth reflective surface 49b and the third reflective surface 49a.
The light beams are incident on the fifth reflecting surface 10a of the mirror 10 diagonally downward as reflected light L5.

The finder information display section is disposed upright on the mounting section 42e on the mounting table 42, and includes a light emitting element LED array 51 of a display element which is a means of displaying information for photographing, and a display optical element. The system includes a first display light reflecting mirror 52 that is obliquely installed on a mounting portion 42f on the mounting table 42 opposite to the LED array 51.

Next, the optical path transmission path of the finder device of this embodiment constructed as described above will be explained with reference to FIG. First, the object light L0 is taken in along the optical axis O through the photographing lens 4. Then, following the same optical path as in the first embodiment, at the time of photographing, an image is formed on the surface of the film 16 via the shutter device 15 as photographing light L1, and at the time of viewfinder observation, an image is formed by the subject light reflected by the main mirror 5. It is observed through the eyepiece 11.

On the other hand, the photographing information display light H11 emitted forward from the LED array 51 is reflected obliquely upward by the first display light reflecting mirror 52, and the display light H12 that is the reflected light is reflected by the mirror frame. 49 second display light reflecting mirror 49
g in substantially the same direction as the incident light L4, and the reflected light, display light H13, is reflected diagonally downward at the third and fourth reflective surfaces 49a and 49b of the mirror frame 49 as display light H14. Similarly, the display light H14 is also applied to the fifth reflective surface 10 of the mirror 10.
a and is reflected backward through the eyepiece lens 1 as display light H15.
1 and is observed as a finder image.

As shown in FIG. 6, the incident light L12 is incident light from the upper and lower outer frames of the finder subject, and the display light H15 of this embodiment is located above the corresponding reflected light L16. . Therefore, the photographing information is displayed above the finder subject image frame on the eye point P. FIG. 7 is a diagram showing the display screen of the finder, in which a finder subject image is displayed in the finder subject image frame 57, and a display section 58A above it displays a display image of the information in the finder. focus display 58
a and a strobe light emission display 58b are displayed. Furthermore, an image displayed by a display element (not shown) disposed around the focusing screen 6 is displayed by a condenser lens 7,
Via the prism 8, mirror frame 9, and mirror 10, the image is displayed on the side of the image frame 57 by the eyepiece 11 in a display frame 58B as another photographic information display. For example, the information is
An aperture value 58d, a shutter speed display 58c, an exposure compensation display 58e, etc. are displayed. At the center of the image frame 57, an autofocus frame 57a and a spot photometry range frame 57b are shown.

As explained above, in this embodiment, the prism can be made lighter and smaller as in the first embodiment, and the prism 8 and the mirror frame 49 can be made smaller and lighter.
Since there is no need to arrange the display member on the upper part of the prism, there is sufficient space for installing the strobe unit in front of or above the prism, and a compact and highly functional camera can be provided. Furthermore, since the reflection mirror 49g for display light can be provided integrally with the mirror frame 49, the number of man-hours for adhesion, assembly, etc. is unnecessary, which is advantageous in terms of cost.

FIG. 8 shows a longitudinal sectional view of the optical system of a single-lens reflex camera incorporating a finder device according to a third embodiment of the present invention. In this embodiment, as in the second embodiment, the display means is disposed on the mounting table below the mirror frame, but the second display light reflecting mirror is integrally provided with the reflecting mirror for imaging the subject. It is characterized by The other optical transmission paths of the subject image are the same as those in the second embodiment.

The finder device of this embodiment is composed of first and second optical blocks, a screen 6, a condenser lens 7, etc., and an eyepiece 11, etc., as in the previous embodiment. The mounting table 62 includes a prism 8 that is a first optical block, a mirror frame 69 that is a second optical block, a transmissive LCD 71 that is an information display element in the viewfinder that is a display means of the display device, and its backlight. A display light reflecting mirror 73, an LED 72, a display optical system, and the like are fixed. Further, a mirror 60 is fixed to the mirror frame 69. The mirror 60 has a fifth reflecting surface 60a for reflecting object imaging light and a display light reflecting surface 60b having a predetermined different angle with respect to this reflecting surface 60a. In addition, the above-mentioned reflective surfaces 69a, 69b, 60a,
60b is a mirror surface made of plastic as a base material and subjected to aluminum vapor deposition.

As shown in FIG. 7, the optical path transmission path of the finder device of this embodiment configured as described above follows the same optical path as that of the second embodiment with respect to the optical path of the subject light, and It is emitted in the direction. On the other hand, LCD71
The optical path of the display light H21 for photographing information emitted through the
The display light reflection mirror 73 reflects diagonally upward and backward, and the display light H22, which is the reflected light, is reflected by the third mirror frame 69.
, 4 reflection surfaces 69a and 69b diagonally downward and backward. The display light H23, which is the reflected light, is reflected by the display light reflection surface 60b of the mirror 60, and the display light H23, which is the reflected light, is reflected by the display light reflection surface 60b of the mirror 60.
4 enters the third and fourth reflecting surfaces 69a and 69b again. The display light H25, which is the reflected light, is reflected from the reflective surface 60.
It is reflected at a position below a and is emitted to the rear eyepiece lens 11 as display light H26.

Incident light L12 is incident light from the upper and lower outer frames of the finder subject, and the display light H26 of this embodiment is located below the corresponding reflected light L16. Therefore, the photographing information is displayed below the finder subject image frame on the eye point P, and a finder image similar to the screen shown in FIG. 5 is obtained.

As explained above, in this embodiment,
Similar to the second embodiment, the prism can be made lighter and smaller, and since there is no need to arrange the display part on the upper part of the prism 8 or the mirror frame 69, the display member can be placed in front of or above the prism. Sufficient space is provided for the strobe unit, and a compact yet highly functional camera can be provided. Furthermore, a fifth reflecting surface 60a for reflecting the object imaging light.
Since the reflecting mirror 60b for display light can be attached to the mirror 60 having the mirror 60, there is no need for man-hours for bonding, assembling, etc., which is advantageous in terms of cost.

[0043]

[Effects of the Invention] As described above, in the finder device of the present invention, since the display light that displays information for photographing does not pass through the prism, the size of the exit surface of the prism can be reduced to the necessary minimum size. Furthermore, the optical path of the display light is disposed behind the prism, and is emitted so as to be reflected in a folded state below the roof mirror. Therefore,
The present invention has remarkable effects such as being able to effectively utilize the space in the finder section, making it possible to make the prism smaller, and furthermore, making it possible to make the camera smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an optical system of a camera incorporating a finder device showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line DD in FIG. 1;

FIG. 3 is a perspective view of the optical system of the camera shown in FIG. 1;

FIG. 4 is an exploded perspective view of the mounting table and mounting frame of the camera shown in FIG. 1;

FIG. 5 is a diagram showing a finder image taken by the finder device of the camera shown in FIG. 1;

FIG. 6 is a longitudinal cross-sectional view of the optical system of a camera incorporating a finder device showing a second embodiment of the present invention.

7 is a diagram showing a finder image taken by the finder device of the camera shown in FIG. 6; FIG.

FIG. 8 is a vertical sectional view of an optical system of a camera incorporating a finder device showing a third embodiment of the present invention.

[Explanation of symbols]

8………………………………Prism 8a………………………………Incidence surface 8b………………………………First reflective surface 8c……………………
......Second reflective surface 8d......Emission surface 9, 49, 69...Mirror frame (roof mirror) 1
0, 60……………………Mirror (reflector) 11……
……………………Eyepiece (eyepiece optical system) 31, 71
...Transparent LCD (display means for displaying information for photographing) 51 ......................LED array (display means for displaying information for photographing) 34, 35, 49g, 52, 60b ,73………………
…Display light reflecting mirror (display optical system)

Claims (1)

[Claims] Claim 1: An entrance surface into which subject light is incident from a photographing optical system, a first reflection surface that reflects the incident light diagonally downward and backward, and the reflected light of the first reflection surface is directed upward diagonally backward. a prism having a second reflective surface that reflects, an exit surface that outputs the reflected light from the second reflective surface backward; a roof mirror that receives light from the exit surface of the prism; A reflector that reflects light, an eyepiece optical system that makes it possible to observe the reflected light of the reflector, a display means that is provided behind the prism and displays information for photographing, and a display of this display means that A finder device for a camera, comprising: a display optical system that emits light toward a roof mirror.