JP2006235246A - Finder device for single-lens reflex camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a finder device capable of facilitating the positioning of components of a finder optical system so that their optical axes are matched with each other and reducing the number of components and assembling man-hours, thereby enhancing its cost performance. <P>SOLUTION: In a mirror box 2, on which the main mirror 3 of the finder optical system of a single-lens reflex camera is set, a pentaprism 5 is inserted from above, and an SI display plate 10, a spacer 14, and a focusing screen 4 are inserted in this order from bottom. They are pressed upwards by a pressing plate 15 so as to be fixed. Positioning recesses by which the optical axes of the components of the finder optical system coincide are directly set on the mirror box 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device in a viewfinder of a camera, particularly a single-lens reflex camera.

  2. Description of the Related Art Conventionally, as a display device in a camera finder, it has been common to display camera shooting information using numerical values or pictograms in a portion outside the field of view using an LED or LCD. However, in recent years, a camera that displays photographing information as a superimpose display in the field of view in addition to the viewfinder out-of-view display has been proposed. For example, a display panel provided with a reflection part is installed on the focusing screen, and the light reflected by the reflection part by irradiating the light source guided by the light guide from the side of the display panel is visible in the viewfinder field of view. Japanese Patent Application Laid-Open No. 2001-305539 that proposes a display method or a display pattern in which a display member for performing superimpose display is irradiated from a light source above a pentaprism and the back surface of the display member is formed into a microprism shape Japanese Laid-Open Patent Publication No. 2000-122151 discloses a method in which light reflected by a portion can be viewed in the viewfinder field.

  Both adopt a method in which two parts of a focusing screen and a superimpose display plate are placed on the lower side of the pentaprism in the finder optical system of the mirror box, and in Japanese Patent Laid-Open No. 2001-305539, A display device has been proposed in which the pentaprism 5 is received by the upper holder 202, the focusing screen 4 and the display panel 10 are received by the lower holder 201, and the upper and lower holders 201 and 202 are stacked and fixed to the mirror box. .

  Japanese Patent Application Laid-Open No. 8-43916 employs a display method in which the display plate 13 is irradiated from a light source above the pentaprism in order to operate the superimpose function. The pentaprism 12 is received by the prism holder 50, and this prism holder The focusing screen holding frame 52 that receives the display screen 13 and the focusing screen 11 is joined to the lower side of the screen 50 so that the focusing screen holding frame 52 can be opened and closed downward with respect to the prism holder 50 to replace the focusing screen 13. We have proposed a finder device that can do this.

JP 2001-305539 A Japanese Patent Laid-Open No. 8-43916 JP 2000-122151 A

  However, the two methods disclosed in Japanese Patent Laid-Open No. 2001-305539 and Japanese Patent Laid-Open No. 8-43916 are both a pentaprism, a superimpose display plate, and a focusing screen for a mirror box in which a main mirror in a finder optical system is installed. Since there is a separate part for receiving the two main parts and the parts are attached to the mirror box, the cost increases due to an increase in the number of parts and assembly man-hours, and the assembly is not efficient. During the process, it created the cause of defective products such as scratching the superimpose display. In particular, careful attention is required during assembly in order to prevent display misalignment by aligning the optical axes of the three main components of the pentaprism, superimpose display plate, and focusing screen with respect to the viewfinder optical axis. , Was making productivity worse.

  The present invention mainly includes a mirror box in which a main mirror of a finder optical system of a single-lens reflex camera is installed. A pentaprism is inserted from above, a superimposition display plate and a spacer are inserted from below, and the focusing screen is inserted and held in this order. It is possible to obtain a finder device with high accuracy and high productivity by directly placing the positioning recess in the mirror box so that the optical axis of each main part should be matched by pressing the plate upward. I made it.

  In the finder device of the single-lens reflex camera of the present invention, mainly a mirror box for installing the main mirror of the finder optical system of the single-lens reflex camera, a pentaprism from above, a superimpose display plate and a spacer from below, The focusing screens are inserted in the order of the focusing screens and pressed upward with a pressing plate so that they can be fixed. Positioning recesses that should match the optical axes of the main components are directly installed in the mirror box. In addition to easy positioning, the number of parts and assembly man-hours can be reduced, and a finder device with high cost performance can be obtained.

  Hereinafter, the best embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an assembled perspective view of a finder device of a single-lens reflex camera according to the present invention, and FIG. 2 is a central sectional view of the finder device according to the present invention. FIG. 3 is a perspective view showing the shape of a superimpose display board, and FIG. 4 is a perspective view showing the shape of a focusing screen. FIG. 5 is a perspective view showing the shape of the pressing plate. FIG. 6 is a plan view of the cross section of the mirror box as viewed from below, and FIG. 7 is a perspective view showing the upper part of the mirror box.

  The finder optical system of a single-lens reflex camera has an object light passing through a main lens (not shown) centered on the optical axis 1 as shown in FIG. A pentagonal prism 5 forms a subject image that is reflected and imaged on the mat surface of the focusing screen 4 at a position that collides with the imaging position of a photosensitive member such as a film or an imager (not shown) behind the main mirror 3. The upper position 2a of the mirror box 2 occupies an important position for determining the imaging position of the subject and the position of the pentaprism 5 through the eyepiece 6 so as to be visible as an erect real image of the subject at the eye level from the eyepiece 6. ing.

  In general, an information light source is installed on a finder optical path so that a photographer can obtain photographing information while looking at a finder image, and the photographer can visually recognize the information at the same time. The field of view of the finder image is determined by the frame 7a of the mask 7 laid under the pentaprism 5 shown in FIG. 1, and the photographing information displayed outside the field of view is a display light source 8 such as an LED as shown in FIG. Is incident on the optical path, and the display light passes through the display frame 7b of the mask 7 and is visible through the pentaprism 5 and the eyepiece 6 outside the field of view of the subject image.

  In addition to out-of-field information, a superimpose display displays a pattern indicating the photometry position, distance measurement position, etc. with respect to the subject image superimposed on the subject image. In this plan, the superimpose is displayed between the pentaprism 5 and the focusing screen 4. A display board (hereinafter referred to as SI display board) 10 is inserted and displayed here so that it can be visually recognized in the field of view.

  The SI display plate 10 is made of a transparent plate, and the side of the back surface that is in contact with the focusing screen 4 is such that the display pattern 10a as shown in FIG. 1 is formed into a fine prism. As shown in FIG. The LED 11 and the guide prism 12 are fixed to the upper portion of the LED. The light beam LB is applied to the SI display board 10 from a part of the upper surface of the pentaprism 5 as indicated by the light beam LB by irradiating the light source of the LED 11 to the guide prism 12. Since the irradiation can be guided, the light beam LB incident on the SI display plate 10 is reflected only on the portion of the display pattern 10 a formed on the back side fine prism, and this reflected light passes through the pentaprism 5 and the eyepiece 6 and is the subject. The light source of the LED 11 is superimposed on the image so that it can be seen.

  In this way, it is understood that superimposed display is possible by placing the SI display plate 10 on the focusing screen 4, but the SI display plate 10 is added to the conventional finder optical system as compared with a conventional camera having no display. In addition, it is necessary to have a device that can be accurately and reliably inserted so that the optical axes 1 of the respective parts coincide with each other, and the number of parts further increases, resulting in an increase in cost. must not.

  In view of this problem, in the present invention, the upper position 2a of the mirror box 2 is regarded as a reference position, and a method of mounting a finder optical system component including the SI display plate 10 from above is adopted to solve this problem. This will be described in detail below.

  The upper surface of the upper position 2a of the mirror box 2 is formed in the shape shown in FIG. 7, and the protrusions 7c and 7d of the mask 7 are inserted into the grooves 2c and 2d of the mirror box 2 and then the grooves 2c and 2d. Each of the two standing positioning pins 2e is fitted into the holes 7e and 7f of the mask 7, so that the center optical axis 1 of the upper position 2a of the mirror box 2 and the center of the field frame 7a of the mask 7 are matched. Furthermore, since the upper surface of the upper position 2a of the mirror box 2 is formed in accordance with the shape of the bottom of the pentaprism 5, the optical axis of the mirror box 2 when the pentaprism 5 is inserted on the mask 7 1 and the center of the pentaprism 5 can be fixed. Further, the upper part of the finder optical system in the mirror box 2 is completely assembled by pressing from above the pentaprism 5 with the pentahold 13 shown in FIG.

  On the other hand, the lower surface of the upper position 2a of the mirror box 2 is shown in detail in a plan view in FIG. 6, but is formed into a shape as seen from the perspective view of FIG. The finder optical system that enables superimpose display can be completed.

  In the bottom view of the upper position 2a of the mirror box 2 shown in FIG. 6, the upper side is the photographing lens side on which the subject light is incident, and the lower side is the side on which a film or an imager is installed to form a subject image, Has an opening 2b to pass through to the finder side, and a positioning groove and a recess are formed around the opening 2b to improve the accuracy of the installation of the lower parts of each finder optical system. 2g, the right groove 2h, the left recess 2i, and the right recess 2j are for positioning the SI display board 10, and the lower recesses 2k and 2l are for positioning the focusing screen 4.

  The lower parts of the finder optical system arranged in parallel on the lower surface of the upper position 2a of the mirror box 2 are stacked in the order shown in FIG. 1, but first, the upper surface of the SI display board 10 shown in FIG. 3 is the mirror box 2 shown in FIG. When inserted toward the surface of the upper position 2a, the center protrusion 10f of the SI display board 10 is inserted into the center groove 2f, the left protrusion 10g and the right protrusion 10h are added to the left groove 2g and the right groove 2h. The left protruding portion 10i and the right protruding portion 10j of the display board 10 can be inserted into the left recessed portion 2i and the right recessed portion 2j on the surface of the upper position 2a, and cover the SI display plate 10 with high positional accuracy with respect to the opening 2b of the mirror box 2. It becomes the shape that was set.

  Next, as shown in FIG. 1, the focusing screen 4 is inserted with a spacer 14 punched out of a thin metal plate interposed therebetween. The focusing screen 4 is positioned at a common position above the subject imaging surface behind the main mirror 3. Although it must be installed, it needs to be adjusted slightly due to the mounting error of the main mirror 3 and its related parts. Therefore, the thickness of the spacer 14 is adjusted. Depending on the adjustment, the spacer 14 may not be necessary or may be used by overlapping several sheets.

  As shown in FIG. 4, the focusing screen 4 has projecting portions in four directions, and the projecting portion 4a is in front of the mirror box 2 (the lens side on which the subject light is incident), and the projecting portions 4k and 4l are in the back. In this manner, the SI display board 10 is placed so as to overlap with the SI display board 10 from below, but the protrusion 4a is a handle for holding with tweezers or the like at that time, and the protrusions 4k and 4l are the rear wall surface 2m of the mirror box 2 ( The left and right positions of the focusing screen 4 are guaranteed so that the focusing screen 4 can be inserted into the recesses 2k and 2l formed in the lower part of FIG. This is ensured by bringing the rear surface 4m of the focusing screen 4 into contact with the rear wall surface 2m of the mirror box 2 with the spring pressure obtained at the protruding portion 4c.

  Finally, the presser plate 15 is attached to prevent the SI display plate 10, the spacer 14, and the focusing screen 4 from dropping downward while pressing the three components of the focusing screen 4 upward. The pressing plate 15 is a metal plate pressed into a frame shape as shown in FIG. 5, and the left frame side 15d and the right frame side 15e are arcuate, and the front bent pieces 15r and 15s and the rear frame side 15d are formed. The folding screen 15p and 15q are attached to the mirror box 2 so that the arcuate left piece frame 15d and the arcuate right piece frame 15e are deformed almost horizontally, and the focusing screen 4 is installed with a pressing force upward. Is possible.

  A cover plate 16 is attached to the front upper portion of the mirror box 2 with two screws 17 as shown in FIG. 1, and the holding plate 15 shown in FIG. The bent pieces 15p and 15q are inserted into the two long holes 2p and 2q shown in FIG. 7 installed on the back wall surface 2m of the mirror box 2, and the front frame of the pressing plate 15 is pushed forward while applying a pressing force. The bent pieces 15r and 15s are attached to the shelves 16r and 16s on the inner side of the cover plate 16, and at this time, the standing pieces 15b of the arcuate left frame side 15d and the arcuate right frame side 15e of the holding plate 15 are attached. And 15c are attached while applying a pressing force from the front side 4b ′ of the left protruding portion 4b and the front side 4c ′ of the right protruding portion 4c to the rear while sandwiching the focusing screen 4. Left protrusion 4b, right protrusion A spring pressure obtained 4c will be held pressed against the rear surface 4m of the focusing screen 4 on the back wall 2m of the mirror box 2, the position of the front and rear of the focusing screen 4 is ensured.

  As described above, the finder apparatus of the present invention uses the upper position 2a of the mirror box 2 as a reference for mounting, and by positioning and molding the mirror box 2, an accurate mounting position of the finder optical system parts can be obtained at the same time. The direct loading system of parts enables cost reduction by reducing the number of parts and a finder device with high productivity.

It is an assembly perspective view of the finder apparatus of the single-lens reflex camera in the present invention. It is a center sectional view of the finder device in the present invention. It is the perspective view which showed the shape of the superimpose display board. It is the perspective view which showed the shape of the focusing screen. It is the perspective view which showed the shape of the pressing board. It is the top view which looked at the mirror box cross section from the bottom. It is a perspective view of a mirror box upper part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical axis 2 Mirror box 3 Main mirror 4 Focusing screen 5 Penta prism 6 Eyepiece 7 Mask 8 Display light source 9 Display prism 10 SI display board 11 LED
12 Guide Prism 13 Penta Press 14 Spacer 15 Press Plate 16 Cover Plate 17 Screw

Claims (1)

  In the viewfinder device in which a focusing screen and a superimpose display plate are arranged in parallel on the focusing screen so that photographing information can be observed in a subject image formed by subject light, the upper part receives a pentaprism. The lower portion is a mirror box in which the superimpose display plate and spacer, the concave portion and the groove capable of positioning the focusing screen are formed, and the mask plate and the above-mentioned are formed from the upper portion of the mirror box. The pentaprism is inserted from the bottom in the order of the superimpose display plate, spacer, and focusing screen, and can be fixed to the mounting portion of the inner wall of the mirror box while pressing upward with a pressing plate. A single-lens reflex camera viewfinder device.

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