JPH0843916A - Camera - Google Patents

Abstract

PURPOSE:To provide a camera of which superimposing function can be operative even in the case a conventional focusing screen is installed and of which a display member can be taken away easily. CONSTITUTION:Regarding a camera provided with a focusing screen 11, a display member 13 for superimposed display which is set near the focusing screen 11, and a finer optical system which lead light beam transmitted through the focusing screen 11 and the display member 13; the camera has a characteristic of having display member holding means 50, 51 which hold the display member 13 in the way the member 13 can be detached freely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a single-lens reflex camera, a still video camera and the like, particularly a camera having a superimpose display device.

[0002]

2. Description of the Related Art Conventionally, there is known a so-called superimpose display technique which is used in a camera or the like having a plurality of distance measuring fields and displays a selected distance measuring field by superimposing it on a subject image in a viewfinder field. . By superimposing the image and the display, the "position" of the display and the "state" of the display are extremely intuitive to the user, for example, with the meanings of "autofocus distance measuring field of view" and "focusing", respectively. It is possible to convey it.

An example of a camera having such a superimposing display device is, for example, Japanese Patent Laid-Open No. 4-34515.
No. 0, or the one disclosed in JP-A-6-82678 is known. The technique described in the former relates to a single-lens reflex camera having a structure in which a guest-host type liquid crystal display panel is arranged between a pentaprism and a focusing screen, and two box-shaped supports are double-bottomed. A liquid crystal display plate is housed in the middle of the double bottom so as to form the image, so that the subject image and the display content can be viewed at the same time.

The latter is a principle in which a display unit is formed by an assembly of minute prisms on a focusing screen of a camera, and when the display unit is illuminated obliquely, only the light refracted by the prisms can be seen through a finder optical system. Based on, the light-emitting type superimpose display is realized.

In these known techniques, respectively,
The liquid crystal display panel and the focusing screen function as a display member for the superimposed display device.

[0006]

However, such a camera has the following drawbacks and is not satisfactory.

First, in the camera disclosed in Japanese Patent Laid-Open No. 4-345150, in order to remove the liquid crystal display plate, the camera must be disassembled. For example, repair when dust adheres to the liquid crystal display plate. However, there was a drawback that it required an extremely large number of man-hours. Dust on the display plate is easily noticeable because the diopter of the finder optical system matches this.
Very often it obstructs the observation of the subject image.

Since the liquid crystal display panel cannot be replaced,
It was impossible to use display panels with different display formats and select and use them.

On the other hand, in JP-A-6-82678,
Since the display unit is provided on the focusing screen, for example, JP-B-57-16175 and JP-B-57-3 are used.
If the technique disclosed in 7132 is used, the focusing screen that also serves as a display member for superimposing can be easily configured to be removable. However, in this case, it is necessary to form the display unit in advance on all of the replacement focusing screens with engraved scale lines or screen frames for panoramic photography, and in general, replacement focusing screens for cameras are often used in many models. Despite being configured to be used in common with the camera, cameras that incorporate this type of superimposing device cannot use the replacement focusing screen that existed before that. Especially in single-lens reflex cameras, compatibility of accessories is regarded as important, so this defect greatly impairs the commercial product.

In view of the above-mentioned drawbacks of the conventional camera, an object of the first invention of the present application is to operate the superimposing function even when the conventional focusing screen is mounted, and to easily remove the camera. It is to realize a possible display mechanism.

That is, it is an object of the present invention to provide a camera capable of simultaneously satisfying the two requirements of repairability when dust adheres to a display plate for superimposing display and compatibility with a general-purpose focusing screen.

[0012] A second object of the present application is to prevent the mistakenly removing the reflecting plate with respect to a possible misunderstanding between the focusing screen and the display member when the first object is achieved. It is to prevent.

That is, in general use,
It can be considered that the frequency of exchanging the focusing screen is overwhelmingly higher than the frequency of exchanging the display member, but all of them are colorless plate-shaped members having a size substantially equal to the screen size and are easily mistaken. Moreover, even though the replacement frequency is high when the two are compared, absolutely no replacement of the focusing screen is made, and it is difficult for the user to distinguish between the display member and the focusing screen. Is. Therefore, a structure in which the holding release on the focusing screen side of the two members arranged adjacent to each other is prioritized is realized.

A third object of the present invention is to realize a mechanical structure that does not damage the focusing screen when removing the display member.

[0015]

Means and Actions for Solving the Problems First of the Invention
According to a first aspect of the present invention, there is provided a structure in which a focusing screen, a display member for superimposing display arranged near the focusing screen, the focusing screen and the display member are transmitted. A camera having a viewfinder optical system for guiding a light beam is characterized by further comprising display member holding means for detachably holding the display member.

With this structure, it is possible to realize a display member which can be easily removed while operating the superimposing display function even when the conventional focusing screen is mounted.

According to a second aspect of the present invention, there is provided a focusing screen and a focusing screen.
Focusing screen holding means for detachably holding the focusing screen, a display member for performing a superimposed display in the viewfinder, display member holding means for detachably holding the display member, and a photographing optical path. And a shielding means for shielding the display member holding means. When the shielding means is removed, both the focusing screen holding means and the display member holding means can be released and the shielding means is attached. In the state, the camera is characterized in that only the focusing screen holding means can be released.

With this structure, the attaching / detaching operation of the focusing screen can be performed without removing the shielding means, but since the attaching / detaching operation of the display means can be performed only after removing the shielding means, the focusing screen frequently replaced. It can be prevented from being confused with the display member.

According to a third aspect of the present invention, as in claim 3, in the second aspect, the display member holding means holds the focusing screen held by the focusing screen holding means. The held display means is characterized by being prevented from being removed by the focusing screen or the focusing screen holding means.

With this structure, the display member cannot be removed unless the focusing screen is removed.
There is no accidental damage to the focusing screen when removing the display member.

[0021]

1 to 21 show an embodiment of a camera according to the present invention.

First, the structure of the superimposed display will be described with reference to FIGS. 4 and 5. FIG. 4 is an example of a single-lens reflex camera according to the present invention. FIG. 4 is a cross-sectional view of the camera seen from the side, and FIG. 5 is a perspective view of the camera seen from above. The superimpose display device described here is composed of a display member that is actually visible through the viewfinder and an illumination device that irradiates the display member with light. In the following embodiments, the distance measuring field frame serves as the display unit.

In the figure, 5 is a single-lens reflex camera main body, F is a film, 10 is a movable mirror that jumps up during film exposure,
Reference numeral 11 is a focusing screen having a Fresnel lens 11a on the light incident surface and a matte surface 11b on the light emitting surface.
Has a display portion for superimposing display on a surface 13g, which will be described later, and is a reflector serving as a display member, 15 is a condenser lens, 12 is a pentaprism, and 14a,
Reference numeral 14b is an eyepiece lens, and 16 is a protective glass, which constitute a finder system.

Reference numerals 6 and 7 are a photometric sensor and a photometric lens for measuring the brightness of the object, and 19 is a projection lens, which is arranged from the upper front part to the upper part of the pentaprism. Five LED packages 18a, 18b, 18c, 18 each containing a light emitting diode (hereinafter referred to as an LED), which is a light source, inside the pentaprism.
d * 18e and the mask 20 are attached. This L
The wavelength of the ED is in the visible light range, enters the light projecting lens 19, and the luminous flux reflected / condensed therein is guided to the distance measuring field frame of the reflecting plate 13 to make the superimpose display function. Are configured.

Reference numeral 8 is an upper cover for accommodating each of these elements. An accessory shoe 9 is provided on the upper cover 8 so that a flash photography device or the like can be connected. The LED package is arranged between the apex of the penta prism 12 and the accessory shoe 9.

FIG. 6 is a view for explaining the viewfinder field of the camera. 68a from the center of the screen, lined up horizontally
Reference numeral 68e is a distance measuring field frame on the finder, which represents the distance measuring field position of the focus detection device (not shown), and is an image of the distance measuring field frame on the reflector, which will be described later. The viewfinder field of the camera includes an out-of-field display unit (not shown) that displays shooting conditions such as a shutter speed, an aperture value, and an exposure correction amount located outside the subject image field 68, and a measurement position located inside the subject image field 68. It is composed of distance field frames 68a to 68e, and the distance measurement field frame is a superimpose display that can be observed simultaneously with the subject image 68f.

Next, the display principle of the display device will be described. 16 is a plan view of the reflection plate 13 as seen from the direction of the surface 13g on which the display section, that is, the distance measuring field frame is formed, and FIG. 7 is an enlarged cross-sectional view of one line of the distance measuring field frame seen from the side.
It is the same for each ranging field frame. This figure shows that the distance measuring field frame formed on the reflecting plate is composed of a large number of fine prisms along the vertical direction of the paper in both vertical and horizontal lines. Its cross-sectional shape is a collection of triangular protrusions each having one ridge. Therefore, the light flux that has entered the ranging field frames 13a to 13e through the taking lens (not shown) is refracted here and deviates from the direction of the eyepieces 14a and 14b.
It is visible darker than b.

On the contrary, when the distance measuring field frame of the reflecting plate is illuminated obliquely from above, for example, when attention is paid to the light ray L, it is incident on the reflecting plate 13 and then the slope 13aa of the prism constituting the distance measuring field frame. Slope 13b that is totally reflected at and further faces
Even in b, the light is totally reflected and goes upward. On the other hand, the light flux that has not entered the prism forming the distance measuring field frame passes through the focusing screen and exits toward the movable mirror 10 and is not visually recognized.

The distance measuring field frame composed of such fine prisms has a characteristic of deflecting light from obliquely above to a right above.
By utilizing this characteristic, it is possible to change the display color of the ranging field frame by controlling the illumination light. L described above
The illumination device provided with the ED is for realizing such superimposing display. For example, if a red LED is used, when the distance measuring field frame which normally looks black is focused on that position. You can use it to make it glow red.

The principle of display is the same for the distance measuring field frame located off the optical axis of the finder, and when the optical path is expanded, the optical path connecting the eyeball of the user and the distance measuring field frame is traced in the opposite direction. If there is an LED serving as a light source, the distance measuring field frame shines and is visually recognized. Further, it is possible to manufacture a display member having the same function by vapor-depositing a reflecting surface on the focusing screen.

Returning to FIGS. 4 and 5, the operation of the lighting device will be described. Since the illumination optical system has a bilaterally symmetrical shape, the description will be given for the LED packages 18a, 18b, 1
8c only for the optical path corresponding to 8c.

First, the light emitted from the LED package 18 a is narrowed down by the opening provided in the mask 20 and enters the light projecting lens 19. The light projecting lens 19 is composed of a large number of divided surfaces as shown in the detailed plan view of FIG. 8, the perspective view of FIG. 9, and the perspective view of FIG. 10, and the surface 19a is separated from the LED package 18a. Is the incident surface of the luminous flux. In FIG. 10, the mask 20 is omitted in order to show the layout of the LED package in detail. The light flux entering the projection lens 19 from the surface 19a is
The light is totally reflected by the surface 19e and the following surface 19f1 and reaches the lens portion at the tip with almost no loss. Due to the bending of the optical path by these reflecting surfaces, the illumination optical system has a shape along the upper part of the pentaprism 12.

There are three lens portions at the tip of the light projecting lens 19, and of the light flux emitted from the LED package 18a, only the light flux that has passed through the lens portion 19g becomes an effective light flux. That is, even if the luminous flux passing through unexpectedly is reflected by any of the distance measuring field frames (display units), the direction thereof does not go to the eyepiece lenses 14a and 14b and is not visually recognized through the viewfinder.

The lens portion 19a is provided with the above-mentioned reflector plate 13.
And the mask 20 are placed in a projection relationship, and the light flux emitted from this is condensed and then the surface 1 of the pentaprism 1
The light enters from 2a into the penta prism. After that, the light is emitted from the surface 12b of the pentaprism, passes through the condenser lens, and the distance measuring field frame 13a provided on the lower surface of the reflection plate 13 is provided.
To reach. The light irradiation area on the surface 13g of the reflection plate is determined by the size of the opening of the mask 20 described above, and includes at least the distance measuring field frame 13a, and the adjacent distance measuring field frame 13b is provided to prevent display crosstalk. , 13d. The behavior of the light beam on the reflection plate 13 is as described with reference to FIG. 7.

By setting the size of the lens portion 19g to be larger than that of the distance measuring field display 13a, when the distance measuring field frame (display section) on the reflector 13 is viewed through the finder, the distance from the optical axis is increased to some extent. Even if the position of the eye is off, it is guaranteed that the light ray reaching the eye from the LED package 18a exists and is visible.

Next, the light emitted from the LED package 18b will be described. The light emitted from the package 18b is similarly focused by an opening (not shown) provided on the mask 20, and then enters the light projecting lens 19. At this time, the surface 19b is L
It becomes the incident surface of the light flux from the ED package 18b. The light flux entering the projection lens 19 is a surface 19e and a surface 19f that follows.
The light is totally reflected at 2 and guided to the lens part, of which the lens part 1
The luminous flux incident on 9h becomes an effective luminous flux. This lens part 1
9h also has the function of placing the reflection plate 13 and the mask 20 in a projection relationship, and the light flux emitted from this is condensed and then enters the pentaprism from the surface 12a of the pentaprism. After that, the light is emitted from the surface 12b of the pentaprism, passes through the condenser lens, and the distance measuring field frame 13 of the reflector 13
reach b. The light irradiation area on the reflection plate 13 includes at least the distance measuring field frame 13b, and is a range not covered by the adjacent distance measuring field frames 13a and 13c in order to prevent display crosstalk.

Finally, the light emitted from the LED package 18c is focused by an opening (not shown) also provided in the mask 20, and then enters the light projecting lens 19. At this time, surface 19c
Is the incident surface of the light flux from the LED package 18c.
The light flux entering the light projecting lens 19 is first totally reflected by the surface 19 and replaced with the light flux from the LED package 18b. The reason for exchanging the optical paths is to lay out a large-sized LED package which is advantageous in terms of light quantity.
If the total reflection surface 19d is not provided, the LED package 18c is provided between the LED packages 18a and 18b.
Must be inserted, and at this time, the light amount is extremely reduced due to the use of a small package.

Now, the light flux reflected by the surface 19d is the surface 19
The light is totally reflected by the surface 19f2 following the e and reaches the lens portion at the tip. Similar to the light flux from the LED package 18b, the light flux incident on the lens portion 19h becomes the effective light flux. As described above, the lens portion 19h has the function of placing the reflection plate 13 and the mask 20 in a projection relationship, the light flux emitted from this is condensed, and then enters the pentaprism from the surface 12a of the pentaprism. . After this, the surface 12b of the pentaprism
And then reaches the distance measuring field frame 13c of the reflecting plate 13 through the condenser lens. The light irradiation area on the surface 13g of the reflecting plate includes at least the distance measuring field frame 13c, and the adjacent distance measuring field frame 13 is provided in order to prevent display crosstalk.
The range does not overlap with b.

Here, the light flux from the LED package 18b and the light flux from the LED package 18c are projected through the same lens portion 19h because the distance between the distance measuring field frames is narrow, so This is because the areas that should exist are overlapping. That is,
When the layout of the distance measuring field frames as shown in this embodiment is adopted, if the distance measuring field frames 13b and 13c can be visually recognized by giving a degree of freedom to the position of the eye looking into the viewfinder, the LED which should be in the eyes. The passing areas of the light on the lens portion mean that the distance measuring field frames overlap each other. Therefore, by providing a common lens portion for a plurality of distance measuring field frames in this manner, superimposing display can be performed even in a high density arranged distance measuring field. The above technique is of course effective not only for the field of view for distance measurement but also for various displays.

11 and 12 are views for explaining the holding mechanism for the display member, the focusing screen and the like.

In FIG. 11, reference numeral 50 is a prism holder for holding the condenser lens 15 and the pentaprism 12. The prism holder is a box-shaped support, and a rectangular opening for taking in the light flux from the focusing screen and a positioning surface 50c of the focusing screen 11 are provided below the prism holder, and the condenser lens 15 is provided therein.
And the holding surface 50d of the reflector 13 and the positioning surface serving as the pedestal portion of the pentaprism 12, and the bearing and the reflector 13 serving as the center of rotation of the focusing screen holding frame 52 at the rear end.
Has a holding surface, and the front surface has a mounting surface for a holding member described later.

Reference numeral 53 designates a prism holder for fixing the pentaprism 12 to the prism holder 50, and 54
Is a holding spring (only one of a pair of left and right is shown) that engages the two hooks 50a and 50b of the prism holder and the hook 53a of the prism holder 53 and presses the prism holder 53 downward.

Reference numeral 51 is a holding member fixed to the prism holder 50. As shown in detail in FIG. 12 when viewed from the direction of arrow B in FIG. 11, the holding member 51 has two holes 5 in the center.
1a, 51b and one spring portion, a thin plate having two arm portions at both ends, and after inserting the pin 62 into the two holes 51a and 51b and the corresponding holes (not shown) on the prism holder, It is fixed by crimping it. The holding member 51 constitutes a focusing screen holding mechanism together with the prism holder 53 and the focusing screen holding frame 52, and a display member holding mechanism together with the prism holder 53. The reflector 13 is housed inside the prism holder 50, and the focusing screen 11 is housed inside the focusing screen holding frame 52. The distance measuring field frame drawn in the center of the reflecting plate 13 shows a state in which what is formed on the back surface 13g is visible through the front surface. The constituent elements shown in FIG. 11 can be integrally handled as a finder unit.

13 to 15 show a method of assembling the above finder unit into a camera, a holding structure for an illuminating device,
FIG. 6 is a diagram for explaining an operation member in a completed state of the camera.

Reference numeral 63 in the perspective view shown in FIG. 13 is the finder unit, which is assembled to the mirror box 57 from above. Although the holding and driving mechanism of the movable mirror 10 is publicly known, it is omitted here, but it is configured inside and on the side of the mirror box 57.

Reference numeral 55 denotes a lens holder, which integrally holds the light projecting lens 19, the LED packages 18a to 18e, and the mask 20, and is further drawn in the figure to cover the LED package. 64 makes the electrical connection of the LEDs. The lens holder 55 is fixed to the prism retainer 53 with a fixing screw 56, and as shown in the front view of FIG. 14, the illumination device including the LED and the light projecting lens is connected to the finder unit holding the reflector and the focusing screen. Complete.

Further, from the front of the mirror box 57, a shielding member 58 to which shock absorbing members 59 and 60 for absorbing the shock when the movable mirror 10 is raised is attached is a fixing screw 6.
The viewfinder unit 63 is attached by means of No. 1 so that it cannot be seen through the mount 65 (FIG. 15).

FIG. 15 is a front view of the completed camera. In this state, the spring portion 51h of the holding member 51 can be operated through the notch in the center of the shielding member 58, and the focusing screen holding mechanism is released by pulling the spring portion 51h in the front direction of the drawing as described later. .

The shield member 58 can be removed through the mount 65 by releasing the fixing screw 61 to release the connection with the mirror box 57. When the shield member 58 is removed, the arm portions 51f and 51g of the holding member 51 shown in FIG.
The holding of the reflection plate 13 is released by pulling the two arm portions toward the front side of the drawing using k.

Next, the display member holding mechanism will be described in detail with reference to FIGS. 1 to 3 are cross-sectional views of main parts, FIG. 1 is a view showing a holding state of a display member and a focusing screen, FIG. 2 is a view showing a state in which the holding of the focusing screen is released, and FIG. 3 is a shielding member 58. FIG. 11 is a diagram showing a state in which the display member and the holding of the focusing screen are both released after removing the display member. Therefore, the holding release of both mechanisms is performed in the order of FIGS. 1 to 3, and conversely, the mounting of the display member and the focusing screen is performed as shown in FIG.
From FIG. 1 onward.

First, the reflector 13 which is a display member.
Regarding the holding state of the above, when the elements related to the position regulation in the optical axis direction are listed, the two projections 13h and 13i of the reflector shown in FIG. 11, the claws 51d formed at the tip of the arm of the holding member 51, 51e (FIG. 12), the notch 13f of the reflection plate (FIGS. 3 and 11), and the reflection plate holding surface 50d (FIG. 3) which is the back surface of the focusing screen positioning surface 50c of the prism holder.

The cutout 13f of the reflection plate 13 is supported by the reflection plate holding surface 50d, and the two projections 13h and 13i excluding the cutout 50c (FIG. 14) of the prism holder 50 are claws 51d, respectively. By being supported from below by 51e, the reflection plate 13 is configured not to fall from the space below the condenser lens 15. On the other hand, the position regulation in the surface direction of the reflector 13 is
One is fitting of the protrusions 13h and 13i with the notches 50c of the prism holder 50, and then the arm portions 51f and 51g of the holding member 51 are the two protrusions 13h and 1 of the reflecting plate.
Press 3i in the direction of arrow C in FIG.
f is brought into contact with a corner of the reflection plate holding surface 50d.

The process of attaching or detaching the reflector will be described. The reference diagram is FIG. As for the attachment / detachment of the reflection plate 13, the shielding member 58 is removed through the mount 65 as described above, and the standing bent portion 51 of the holding member 51 is removed.
This is performed by pulling the two arm portions 51f and 51g toward the front side of the paper using j and 51k. When already installed, the supporting members 51d and 51e of the holding member 51 are unsupported, so that the reflection plate 13 is cut and rotatable about the following 13f, and pulled in the direction of arrow D in FIG. As a result, the reflector 13 can be removed. In addition, when mounting, the reflection plate is rotated to the holding position while pulling the arm portions 51f and 51g in the front direction of the paper surface, and then the arm portion 5
If 1f and 51g are returned, the position is regulated as described above and the mounting is completed. As described above, the flexibility of the holding member 51 is used to set and release the reflection plate 13, and
This is performed by elastically deforming f and 51g.

Dust on the reflecting plate 13 is conspicuous because the diopter of the finder optical system matches it, and very often obstructs the observation of a subject image. Can be easily removed,
The inside can be cleaned very easily. Furthermore, since the display member cannot be removed until the holding of the focusing screen is released, the focusing screen is not damaged when the display member is removed.

Further, as shown in FIG. 16 to FIG. 18, it is possible to prepare a reflecting plate 13 having display portions of various display forms and allow the user to selectively use it. FIG. 16 corresponds to FIG.
17 is a plan view of the reflecting plate shown in FIG. 17, FIG. 17 is an example of the reflecting plate faithfully representing the shape of the distance measuring field of the distance measuring device (not shown), and FIG. 18 is an example when the distance measuring field is not displayed. From these, it is possible to make a selection according to the user's preference.

Next, the focusing screen holding mechanism will be described. As shown in FIG. 1, the focusing screen holding frame 52 is a frame-shaped member that rotates about an axis A, and the focusing screen 11 is provided inside.
To store. The projection 51c of the focusing screen holding frame engages with the opening 51c provided on the spring portion 51h of the holding member 51.

When the tip of the focusing screen holding frame 52 is pulled upward from the state shown in FIG. 2, the protrusion 52c pushes the slope 51i of the spring 51c away, and when further raised, the protrusion 52c falls into the opening 51c. The position is fixed like 1. With this,
Focusing screen 11 is prism holder 50
Positioning is performed in the optical axis direction in contact with the positioning surface 50c. On the contrary, when removing the spring portion 51c, the projection portion 52c is disengaged by pulling the spring portion 51c.
1 is lowered by its own weight together with the focusing screen holding frame 52 to the state shown in FIG. After that the protrusion 11
All you have to do is hold a (Fig. 11). 19 and 2
As shown in FIG. 0, if a replacement focusing screen having a scale line 66 or a screen frame 67 for panoramic photography engraved is prepared, the replacement can be performed according to the above method.

Since the reflecting plate and the focusing screen are separately provided in this manner, the replacement focusing screen made to be commonly used by many models is superposed even when used in the camera according to the present embodiment. The display of the distance measuring field frame by the imposing device works, and the compatibility of the conventional accessories can be completely maintained while taking advantage of the new display function of the camera.

FIG. 21 is a view showing the finder field when the reflector shown in FIG. 17 and the focusing screen shown in FIG. 19 are selected. As in this embodiment, three types of reflectors and three
When there are various kinds of focusing screens, the number of combinations is 9, and the user has a great freedom of choice.

By the way, in a general use condition, the frequency of exchanging the focusing screen may be overwhelmingly higher than the frequency of exchanging the reflecting plate. However, in each case, a colorless plate having a size substantially equal to the screen size is used. It is a member and easy to make a mistake. However, in a normal state where the shielding member 58 is provided, only the focusing screen can be removed, and the reflector can be removed only when the shielding member 58 is removed. The failure to remove the reflector is prevented in advance.

Further, in the above structure, since the focusing screen 11 and its holding mechanism are positioned within the rotation locus when the reflecting plate 13 is removed, the reflecting plate cannot be removed unless the focusing screen is removed. It cannot be done and it is a double error prevention measure.

[0062]

According to the first aspect of the present invention, the superimposing function is operated even when the conventional focusing screen is mounted, and the display member can be easily removed. Therefore, it is possible to remove dust adhering to the display member without disassembling the camera. In addition, it is not necessary to form a display unit on all of the replacement focusing screens in advance in order to operate the superimposing device, and use a general-purpose focusing screen that can be commonly used by many models. You can In particular, in a single-lens reflex camera in which compatibility of accessories is important, it will greatly improve the marketability.

According to the second aspect of the present invention, it is possible to prevent the mistake of removing the reflecting plate by mistake due to the mistake of the focusing screen and the display member.

Further, the user can freely select and use the combination of the display member and the focusing screen.

According to the third aspect of the invention, the focusing screen is not damaged when the display member is removed.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing a state in which a focusing screen holding frame is opened in the finder optical system shown in FIG.

3 is a cross-sectional view showing a detached state of a reflection plate in the finder optical system of FIG.

FIG. 4 is a sectional view of a superimpose display device for a camera according to an embodiment of the present invention.

5 is a top view of FIG.

FIG. 6 is a view showing a finder field of view by the superimpose display device of FIG.

7 is an enlarged cross-sectional view of a reflector of the superimpose display device of FIG.

FIG. 8 is a plan view of a light projecting lens of the superimpose display device of FIG.

9 is a perspective view of the light projecting lens of FIG.

10 is a perspective view showing an illumination optical system of the superimpose display device of FIG.

FIG. 11 is an exploded perspective view of a finder unit showing an embodiment of the camera of the present invention.

12 is a perspective view of the holding member shown in FIG.

FIG. 13 is an exploded perspective view showing a built-in state of a finder unit showing an embodiment of the camera of the present invention.

14 is a front view of the finder unit shown in FIG.

FIG. 15 is a front view showing an embodiment of the camera of the present invention.

FIG. 16 is a plan view of a reflector applicable to the camera of one embodiment of the present invention.

FIG. 17 is a plan view of a reflecting plate applicable to the camera of one embodiment of the present invention.

FIG. 18 is a plan view of a reflection plate applicable to the camera of one embodiment of the present invention.

FIG. 19 is a plan view of a focusing screen applicable to the camera of one embodiment of the present invention.

FIG. 20 is a plan view of a focusing screen applicable to the camera of one embodiment of the present invention.

FIG. 21 is a view showing a view field of a finder when a reflecting plate and a focusing screen mounted on a camera according to an embodiment of the present invention are combined.

[Explanation of symbols]

5 ... Single-lens reflex camera body 6 ... Photometric sensor 7 ... Photometric lens F ... Film 10 ... Movable mirror 11 ... Focusing screen 12 ... Penta prism 13 ... Display plate 14a, 14b ... Eyepiece lens 15 ... Condenser lens 16 ... Protective glass 18a-18e …
LED package 19 ... Projecting lens 20 ... Mask 50 ... Prism holder 51 ... Holding member 52 ... Focusing screen holding frame

Claims (3)

[Claims] 1. A camera having a focusing screen, a display member for superimposing display arranged in the vicinity of the focusing screen, and a finder optical system for guiding the light flux transmitted through the focusing screen and the display member, A camera comprising display member holding means for detachably holding the display member. 2. A focusing screen, a focusing screen holding means for detachably holding the focusing screen, a display member for performing superimposed display in the viewfinder, and a display member for detachably holding the display member. Holding means and shielding means for shielding the display member holding means with respect to the photographic optical path, and with the shielding means removed, both the focusing screen holding means and the display member holding means are released. A camera characterized in that only the focusing screen holding means can be released and operated when the shielding means is attached. 3. The display means held by the display member holding means according to claim 2, wherein the display means held by the display member holding means is removable by the focusing screen or the focusing screen holding means while the focusing screen is held by the focusing screen holding means. A camera characterized by being blocked.