JP4694291B2 - Cameras and single-lens reflex cameras - Google Patents

Description

  The present invention relates to a single-lens reflex camera, and more particularly to an improvement of a single-lens reflex camera in which a focusing screen can be exchanged.

  2. Description of the Related Art Conventionally, a camera that subjects a subject image formed by a photographing optical system such as a photographing lens to photoelectric conversion by an image sensor and displays it on an image display device such as a liquid crystal monitor based on an image signal obtained thereby is generally used. Known to.

  As a camera for displaying such a subject image, in addition to the exposure means for the main exposure, another imaging means is provided for monitoring the object field, and a half mirror is arranged in the finder optical system so that a through image (almost real time) is obtained. There is known a camera that guides a subject luminous flux to an image pickup device for display. In this case, in the through image display mode, images are repeatedly captured by the image sensor and displayed on the display device (see, for example, Patent Document 1). In the camera described in Patent Document 1, a relay optical system is arranged between the quick return mirror and the focusing screen, and the light path is divided in the middle of the relay optical system so as to guide the light flux to the AF sensor.

Furthermore, a single-lens reflex camera that performs live view display (through image display) by configuring a quick return mirror with a half mirror is known (for example, see Patent Document 2).
JP 2000-165730 A JP 2001-186401 A

  By the way, in a conventional single-lens reflex camera (hereinafter, simply referred to as a single-lens reflex camera), a quick return mirror is composed of a half mirror, and a sub mirror is disposed behind the quick mirror. It leads to the sensor. However, in the single-lens reflex camera having such a configuration, the above-described through image display cannot be performed because the sub mirror exists behind the quick return mirror.

  On the other hand, although the camera described in Patent Document 1 can display a through image, it does not have a sub-mirror that is usually arranged behind the quick return mirror, and therefore performs phase difference AF. It was something that could not be done.

  In a single-lens reflex camera, the focusing screen can be exchanged according to the application of the camera. Such replacement of the focusing screen is performed by removing the lens from the mount of the main body and from the opening of the mount. However, in the camera described in Patent Document 2, since the relay optical system is disposed in front of the focusing screen, the focusing screen cannot be replaced or adjusted.

  Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a camera and a single-lens reflex camera that can adjust the position or tilt of a focusing screen while simultaneously achieving through image display and AF.

  That is, the invention described in claim 1 is an optical path splitting unit that is disposed in the photographing optical path and guides a part of the subject light beam to the observation optical path side, a relay optical system that is disposed on the observation optical path side, and the relay optical system And a loupe optical system for observing a subject image formed on the screen. The loupe optical system is detachable. In this state, the position or inclination of the screen can be adjusted.

  According to a second aspect of the present invention, in the first aspect of the invention, the screen can adjust a position of the observation optical path in the optical axis direction or an inclination of the observation optical path with respect to the optical axis. Features.

  According to a third aspect of the present invention, in the first aspect of the present invention, the apparatus further includes a restricting member for restricting the position of the screen, and the camera body has three receiving surfaces arranged on the restricting member. The adjustment is performed by changing the relative position.

  According to a fourth aspect of the present invention, there is provided an optical path dividing unit arranged in the photographing optical path, a relay optical system arranged on the observation optical path side divided by the optical path dividing unit, and a position where the relay optical system forms an image. And a loupe optical system disposed at a position where the screen can be observed, and with respect to the optical axis of the observation optical path, the position of the screen in the optical axis direction and the optical axis The inclination is configured to be adjustable from the direction of the loupe optical system.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the adjustment of the screen changes a relative position with respect to the camera at three positions arranged on a regulating member that regulates the position of the screen. It is characterized by being performed.

  The invention described in claim 6 is the invention described in claim 4, wherein the loupe optical system is detachable.

  According to a seventh aspect of the present invention, in the invention according to the fourth aspect, the screen can be adjusted with the loupe optical system removed.

  According to an eighth aspect of the present invention, there is provided an imaging device disposed in the photographing optical path, a first optical path dividing unit disposed in the photographing optical path, and an observation optical path divided by the first optical path dividing unit. A relay optical system arranged; a screen arranged at a position where the relay optical system forms an image; a second optical path dividing means arranged between the first optical path dividing means and the screen; Ranging means arranged on the transmitted light side divided by the second optical path dividing means, and a loupe optical system arranged at a position where the screen can be observed, the screen comprising: It can be adjusted to an equivalent position with respect to the image plane.

  According to a ninth aspect of the present invention, in the eighth aspect of the invention, the first and second optical path dividing means are half mirrors.

  The invention described in claim 10 is the invention described in claim 8, wherein the first optical path dividing means is a movable mirror.

  According to an eleventh aspect of the present invention, in the invention according to the eighth aspect, the first optical path dividing means is in a retracted state from the photographing optical path during single-frame shooting, and in the photographing optical path during the through image mode. It is in a state of being divided.

  The invention described in claim 12 is the invention described in claim 8, characterized in that a cover glass is disposed at the incident position on the observation optical path side.

  According to a thirteenth aspect of the present invention, there is provided an imaging device that captures an image that has passed through a photographing lens, an optical path dividing unit that is disposed in the photographing optical path and guides the subject image to the observation optical path side, and the observation optical path. A magnifying glass that can be attached to and detached from the camera body for observing a subject optical image formed on the screen, a relay optical system disposed on the side, a screen disposed at an imaging position of the relay optical system, and the screen And the position or tilt of the screen can be adjusted in a state in which the loupe optical system is removed from the camera body.

  According to a fourteenth aspect of the invention, in the invention according to the thirteenth aspect, the screen can adjust the position of the observation optical path in the optical axis direction or the inclination of the observation optical path with respect to the optical axis. Features.

  According to a fifteenth aspect of the present invention, in the thirteenth aspect of the present invention, the apparatus further comprises a restricting member for restricting the position of the screen, and the three receiving surfaces arranged on the restricting member with respect to the camera body. The adjustment is performed by changing the relative position.

  According to a sixteenth aspect of the present invention, the imaging element that captures the subject image that has passed through the photographing lens, the optical path dividing means arranged in the photographing optical path, and the observation optical path divided by the optical path dividing means are arranged. A relay optical system, a screen disposed at a position where the relay optical system forms an image, and a loupe optical system disposed at a position where the screen can be observed, with respect to the optical axis of the observation optical path The position of the screen in the optical axis direction and the tilt with respect to the optical axis can be adjusted from the direction of the loupe optical system.

  According to a seventeenth aspect of the present invention, in the invention of the sixteenth aspect, the adjustment of the screen changes the relative position of the three positions arranged on the regulating member that regulates the position of the screen with respect to the camera. It is characterized by being performed.

  The invention described in claim 18 is the invention described in claim 16, characterized in that the loupe optical system is detachable from the camera body.

  According to a nineteenth aspect of the present invention, in the invention according to the sixteenth aspect, the adjustment of the screen is performed with the loupe optical system removed from the camera body.

  According to the present invention, it is possible to provide a camera and a single-lens reflex camera that can achieve both through-image display and AF and adjust the position or tilt of the focusing screen.

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

(First embodiment)
1 and 2 show a first embodiment of the present invention, which is a cross-sectional view showing a configuration of a main body of a digital single-lens reflex camera according to the present invention, and FIG. 1 shows a state during subject observation. FIG. 2 is a diagram showing a state when the focusing screen is replaced.

  1 and 2, this digital single-lens reflex camera (hereinafter abbreviated as “camera”) mainly includes a camera body 10 as a camera body and an interchangeable lens 80. A desired interchangeable lens 80 is detachably mounted on a body mount 45 provided on the front surface of the lens.

  In FIG. 1, the subject luminous flux incident from the interchangeable lens 80 is reflected by the surface of the main mirror 11 composed of a half mirror, and further enters the prism 13 through the cover glass 12. The subject luminous flux incident on the prism 13 is reflected by a reflecting surface in the prism 13 and a mirror A (hereinafter referred to as mirror (A)) 15, and further via a relay lens 16 composed of a plurality of lenses. An eyepiece which is reflected by a mirror B (hereinafter referred to as mirror (B)) 17 and a mirror C (hereinafter referred to as mirror (C)) 18 and has a focusing screen 103 and a plurality of lenses to constitute a loupe optical system. Through the unit 110, it is observed by a photographer's eye (not shown).

  The prism 13, the mirror (A) 15, the relay lens 16, the mirror (B) 17, and the mirror (C) 18 constitute a relay optical system. These relay optical systems are for re-imaging a subject image formed in the vicinity of the cover glass 12 on the focusing screen 103. The cover glass 12 is provided to prevent dust from entering the relay optical system side.

  The mirror (B) 17 is a second optical path dividing means composed of a half mirror. Part of the subject luminous flux incident on the mirror (B) 17 passes through the mirror (B) 17 and performs automatic distance measurement via the AF optical system 25 arranged behind the mirror (B) 17. Is guided to an AF sensor 27 which is a distance measuring means. The AF optical system 25 includes a condenser lens 21 for collecting a light beam, a separator diaphragm 22 for limiting the light beam, and a separator lens 23 for re-imaging the light beam.

  The focusing screen 103 is fixed by a screen frame holding plate 101 and a screen frame 102, which will be described in detail later. The eyepiece unit 110 is a loupe optical system for observing a subject image formed on the focusing screen 103, and includes a plurality of lenses including a diopter adjustment lens 112 and an eyepiece glass 113. Each lens is held by the eyepiece frame 111. The eyepiece glass 113 is fixed so as to be sandwiched between the eyepiece frame 111 and the eye cup 115. The eyepiece unit 110 is detachably attached to the camera body 10. The details of the mounting structure between the eyepiece unit 110 and the camera body 10 will be described later.

  The main mirror 11 is a first optical path dividing means provided so as to be rotatable about a shaft 11a. 1 is arranged at the position shown in FIG. 1 when observing the object, and moves upward about the axis 11a at the time of photographing, and becomes a position (retracted position) that is retracted from the photographing optical path (not shown). Further, in the present embodiment, the main mirror 11 is composed of a rotatable half mirror. However, the present invention is not limited to this, and the incident light beam is transmitted to the above-described relay optical system side and the imager 35 side described later. Can be divided into a fixed half mirror and a rotatable reflecting mirror that does not transmit light.

  On the photographing optical axis, behind the main mirror 11, an imager 35, which is a first image sensor mounted on the focal plane shutter 33, the low-pass filter 34 and the imager plate 36, is disposed. A substrate 38 loaded with various electrical components is disposed behind the imager plate. Further, a monitor 40 composed of a liquid crystal display or the like is disposed behind the substrate 38. The photographer can visually recognize the image displayed on the screen of the monitor 40 through the monitor window 41 provided on the back side of the camera body 10.

  FIG. 3 is a view showing a state in which the eyepiece unit 110 which is the above-described loupe optical system is removed from the camera body 10.

  The eyepiece unit 110 is detachably attached to the camera body 10 by, for example, a bayonet attaching / detaching mechanism described below. That is, an opening 10a is provided at a position where the eyepiece unit 110 of the camera body 10 is mounted, and an outer peripheral portion of the opening 10a is engaged with a bayonet claw portion 111a formed on the eyepiece frame 111. For this purpose, a bayonet claw portion 10b is formed. The bayonet claw portions 111a on the eyepiece frame 111 side are provided at a plurality of places, for example, three places in the circumferential direction.

  Therefore, the eyepiece unit 110 is detached from the camera body 10 by rotating the eyepiece unit 110 in a predetermined circumferential direction and removing each bayonet claw portion and then pulling it out in the direction of the arrow shown. In this state, since the focusing screen 103 is exposed to the outside, it is possible to remove the focusing screen 103 with a tool such as tweezers. In order to attach the eyepiece unit 110 to the camera body 10, the bayonet claw portions may be engaged with each other in the reverse order to the above-described operation.

  Next, attachment / detachment of the focusing screen 103 will be described with reference to FIGS. 4 and 5.

  4A and 4B illustrate a mechanism for holding the focusing screen 103. FIG. 4A is a diagram illustrating a closed state of the screen frame 102, and FIG. 4B is a diagram illustrating an example of an open state of the screen frame.

  When the camera is used, the screen frame 102 is closed as shown in FIG. That is, the focusing screen 103 is accommodated in the screen frame 102 having an opening surface. As shown in FIG. 4B, the screen frame 102 is provided with a screen frame holding shaft 106 in the downward direction in FIG. 4A. It can be rotated by approximately 90 °.

  In FIG. 4A, a claw portion 102a is formed in the upper direction of the screen frame 102. When the claw portion 102a is inserted into the opening 101a of the screen frame holding plate 101, which is an elastic member, the focusing screen 103 has its surface in a direction perpendicular to the optical axis direction of the loupe optical system. And fixed (the state of FIG. 4A). Then, by removing the claw portion 102a of the screen frame 102 from the opening 101a of the screen frame holding plate 101, the screen frame 102 rotates and the focusing screen 103 can be taken out as shown in FIG. 4B. It becomes a state. That is, in this state, the focusing screen 103 can be replaced or cleaned.

  When the screen frame 102 is closed, the hook 102a is formed on a part of the screen frame holding plate 101 by pushing and rotating the screen frame 102 about the screen frame holding shaft 106 and rotating it. The portion 101b is elastically deformed and enters the opening 101a. As a result, the screen frame 102 is closed.

  Next, a mechanism for fixing the screen frame 102 including the focusing screen 103 described above will be described with reference to FIG.

  5A and 5B illustrate a mechanism for adjusting the focusing screen 103. FIG. 5A is a cross-sectional view thereof, and FIG. 5B is a perspective view thereof. This is a mechanism for accurately adjusting the inclination of the focusing screen 103 to the state of the imager 35, and not only the center position of the focusing screen 103 but also the inclination of the peripheral portion is adjusted. If the tilt of the focusing screen 103 is not adjusted, the subject appears to be in focus on the focusing screen 103, and even if the focus plane may actually shift, it will not be understood. Therefore, the focusing screen 103 must be adjusted accurately.

  A screen frame 102 that accommodates the focusing screen 103 is fixed to a screen cradle 100 that is a restricting member having an opening in the center. Screw holes 123a, 123b, and 123c for engaging with the fixing screws 122a, 122b, and 122c are formed at three locations on the screen cradle 100 around the screen frame 102. In FIG. 5A, the focusing screen 103 has a Fresnel lens surface 103a on the left side (subject side) and a matte surface 103b on the right side (eyepiece lens side).

  On the other hand, screw holes 124a, 124b, 124c corresponding to the fixing screws 122a, 122b, 122c are formed on the surface of the finder main body for fixing the screen cradle 100 facing the focusing screen 103 (FIG. 5B). Are shown only in two places). Although not shown in FIGS. 1 and 2, the finder main body 120 is a component fixed to the camera body 10. Therefore, the position of the focusing screen 103 is fixed by fixing the screen cradle 100 to the finder main body 120.

  The fixing screws 122a, 122b, and 122c are screwed into the screw holes 124a, 124b, and 124c through the screw holes 123a, 123b, and 123c, so that the screen support 100 is fixed to the finder main body 120. Here, by measuring the position of the imager 35 with a measuring device (not shown), a necessary interval is obtained between the screen cradle 100 and the finder main body 120. Therefore, the thickness and number of spacers required between the screen cradle 100 and the finder main body 120 are calculated from this distance.

  For example, in the example shown in FIGS. 5A and 5B, two spacers 121 a and 121 b having different thicknesses are inserted between the screen support 100 and the viewfinder main body 120. The thickness and number of the spacers are changed at each of the three locations corresponding to the fixing screws 122a, 122b, and 122c, whereby the inclination and position of the focusing screen 103 are adjusted.

  Then, the screw portions of the fixing screws 122a to 122c are inserted into the screw holes 123a to 123c of the screen cradle 100 and the determined central opening of the spacer, and further screwed into the screw holes 124a to 124c of the finder body 120. As a result, the screen cradle 100 is fixed to the finder main body 120.

  In this way, the focusing screen 103 can adjust the position of the observation optical path in the optical axis direction or the inclination of the observation optical path with respect to the optical axis from the direction of the loupe optical system.

  FIG. 6 is a block diagram showing the configuration of the electrical system of the digital single-lens reflex camera in the present embodiment. The block diagram of this camera shows a state where an interchangeable lens is attached.

  In FIG. 6, an arithmetic unit 50 controls the entire camera and performs arithmetic operations. The arithmetic unit 50 includes, for example, a CPU having a function of a control unit. A shutter mirror drive motor 52 is connected to the arithmetic unit 50 via a motor drive circuit 51, and a focal plane shutter 33 is connected via a shutter control circuit 53.

  The calculation unit 50 includes an AF sensor 27 for automatic ranging, a photometric sensor 56 for measuring the brightness of the subject, and a charge cam switch (SW) 57 that switches when shutter charging is performed. , Attached to the front curtain (not shown) of the focal plane shutter 33, a front curtain switch (SW) 58 for detecting the fully open state of the shutter opening, and an imager drive circuit for driving the imager 35 60 and a monitor drive circuit 62 for driving the monitor 40 are connected.

  Further, an operation button 65, an operation dial 66, a release switch (SW) 67, a recording medium 69, a memory 70, and an image data memory 71 are connected to the calculation unit 50. Although not shown, the operation button 65 includes a menu button, a cross key, an OK button, and the like, and is used for causing the camera to perform various operations. The operation dial 66 is an operation member as selection means for selecting a shooting mode, a through image mode, and the like at the time of shooting.

  The release switch 67 is a button for executing a shooting preparation operation and an exposure operation. The release switch 67 is composed of a two-stage switch of a first release switch and a second release switch. When a release button (not shown) is half-pressed, the first release switch is turned on and photometric processing is performed. And shooting preparation operations such as distance measurement processing are executed. Further, when the release button is fully pressed, the second release switch is turned on and the exposure operation is executed.

  The recording medium 69 is a recording medium such as various memory cards and an external hard disk drive (HDD) that can be attached to and detached from the camera body 10 via a camera interface (not shown). The memory 70 stores a control program for controlling the entire digital camera in advance. The image data memory 71 is a memory for temporarily storing image data.

  On the other hand, the interchangeable lens 80 drives and controls each part in the interchangeable lens 80, and has a calculation unit 81 composed of a CPU or the like. The arithmetic unit 81 is connected to a focus motor 83 via a motor drive circuit 82, an aperture motor 85, a focus pulse counter 87, a zoom encoder 88, and a memory 90 via an aperture drive circuit 84. .

  The focus motor 83 is a motor for driving a focus lens (not shown) in the interchangeable lens 80 based on the distance measurement result of the distance measurement sensor 55 in the camera body 10. Similarly, the aperture motor 85 is a motor for driving an aperture (not shown) in the interchangeable lens 80 based on the photometric result of the photometric sensor 56 in the camera body 10. The focus pulse counter 87 detects the movement of the focus lens and controls the position when driving the focus lens. The zoom encoder 88 detects a movement signal corresponding to the focal length of a photographing lens (not shown) and outputs the movement signal to the calculation unit 81. Further, the memory 90 is a storage unit in which lens information in the interchangeable lens 80 is stored.

  The calculation unit 81 is electrically connected to the calculation unit 50 in the camera body 10 via a communication connector (not shown). The calculation unit 81 is controlled in accordance with a command from the calculation unit 50 of the camera body 10.

  Next, the operation of the camera according to the first embodiment of the present invention will be described.

  The camera enters the through image mode when the operation dial 66 is operated to select the through image mode. Thereby, the through-image mode subroutine shown in FIG. 7 is operated from the main routine (not shown).

  FIG. 7 is a flowchart for explaining the operation of the camera in the through image mode in the first embodiment. The operation of this camera is mainly performed by the control of the calculation unit 50 in the camera body 10.

  When the live view mode routine is entered, first, in step S1, the state of the first (1st) release switch, which is the half-pressed state of the two-stage release switch 67 described above, is determined. Here, the process waits until the first release switch is turned on. If the first release switch is turned on, it is determined in subsequent step S2 whether or not the in-focus state has been achieved. Here, when it is not in focus, it transfers to step S3 and the state of a 1st release switch is determined again.

  If the first release switch is turned on in step S3, the process shifts to step S4 to calculate the amount of defocus, and in step S5, based on the defocus amount calculated in step S4. Thus, the focus motor 83 is driven via the motor drive circuit 82 to adjust the photographing lens. Thereafter, the process proceeds to step S2. On the other hand, if the first release switch is turned off in step S3, the process proceeds to step S1.

  If the in-focus state is obtained in step S2, the process proceeds to step S6 to perform photometry and its calculation. Here, the aperture value and the shutter speed are determined. Next, in step S7, the state of the second (2nd) release switch, which is the fully depressed state of the two-stage release switch 67 described above, is determined. If the second release switch is not turned on, the process proceeds to step S8, and the state of the first release switch is determined. If the first release switch is turned on in step S8, the process proceeds to step S2. If the first release switch is not turned on, the process proceeds to step S1, and the subsequent processing operations are repeated.

  If the second release switch is turned on in step S7, the process proceeds to step S9 and the monitor 40 is turned off. Subsequently, the shutter mirror drive motor 52 is driven via the motor drive circuit 51 in step S10. Next, in step S <b> 11, the drive of the imager 35 is stopped via the imager drive circuit 60. Thereafter, in step S12, it is determined whether the shutter curtain is closed and the main mirror 11 is up, that is, whether the main mirror 11 is moved from the photographing optical path to a retracted position (not shown), and the shutter curtain is closed and the main mirror 11 is moved. Wait until is completed. When the shutter curtain is closed and the main mirror 11 is up, the shutter mirror drive motor 52 is stopped in step S13.

  Here, in step S14, exposure by the imager 35, that is, imaging is performed. Subsequently, in step S15, the subject image captured by this imaging is read, and in step S16, the aperture motor 85 is driven. In step S17, the shutter control circuit 53 opens the shutter curtain, the shutter mirror drive motor 52 lowers the main mirror 11 (returns from the retracted position to the photographing optical path), and waits until the shutter charge by the charge cam switch 57 is completed. To do. When the opening of the shutter curtain, the lowering of the main mirror 11 and the shutter charge are completed, the process proceeds to step S18 and the shutter mirror drive motor 52 is stopped.

  Next, in step S19, the imager 35 is driven and a through image can be displayed. In step S20, the monitor 40 is turned on. Thus, the subject image as a through image captured by the imager 35 can be confirmed through the monitor 40. Thereafter, the process proceeds to step S1.

  As described above, according to the first embodiment, it is possible to realize a single-lens reflex camera in which both the phase difference AF operation and the through image display are compatible and the focusing screen can be replaced.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  In the first embodiment described above, the inclination of the focusing screen 103 is adjusted by changing the thickness and number of spacers inserted between the screen cradle 100 and the finder main body 120. However, the present invention is not limited to this. It is not something that can be done. For example, in the second embodiment, the inclination of the focusing screen 103 is adjusted by using an adjustment spring instead of the spacer.

  The second embodiment of the present invention will be described below with reference to FIG.

  FIG. 8 shows a second embodiment of the present invention, and is a cross-sectional view of a mechanism for adjusting a focusing screen.

  In the second embodiment, the configuration other than the mechanism for adjusting the focusing screen is the same as the configuration of the single-lens reflex camera of the first embodiment described above. Therefore, in order to avoid duplication of description, in the following description, the same parts are denoted by the same reference numerals, illustration and description thereof are omitted, and only different parts will be described.

  In FIG. 8, a screw hole 123 for inserting the adjustment screw 128 is formed in the screen cradle 100, and a screw hole 127 is formed at a position corresponding to the screw hole 123 of the finder main body 120. Has been. An adjustment spring 129 is inserted between the screen cradle 100 and the viewfinder main body 120 so as to be wound around the adjustment screw 128. That is, the adjustment screw 128 is inserted into the screw hole 123 and the adjustment spring 129 and screwed into the screw hole 127 of the finder main body 120.

  In FIG. 8, only two adjustment screws 128, adjustment springs 129, screw holes 123, and screw holes 127 are shown, but three are actually used. With this configuration, since the screen support 100 is always in contact with the adjustment screw 128 side, the height and inclination of the screen frame 102 are adjusted by adjusting the rotation angle of the three adjustment screws 128. .

  As described above, according to the second embodiment, since the adjustment spring is used instead of the spacer, the inclination of the focusing screen 103 can be adjusted more finely and accurately.

  As mentioned above, although embodiment of this invention was described, in the range which does not deviate from the summary of this invention other than embodiment mentioned above, this invention can be variously modified.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a first embodiment of the present invention and is a cross-sectional view illustrating a configuration of a main body of a digital single-lens reflex camera according to the present invention, illustrating a state during subject observation. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the 1st Embodiment of this invention, and shows the structure of the main-body part of the digital single-lens reflex camera which concerns on this invention, and is the figure which showed the state at the time of replacement | exchange of a focusing screen. FIG. 2 is a diagram illustrating a state in which an eyepiece unit 110 that is the loupe optical system of FIG. The mechanism for holding the focusing screen 103 will be described, wherein (a) shows a closed state of the screen frame 102, and (b) shows an example of the opened state of the screen frame. A mechanism for adjusting the focusing screen 103 will be described, in which (a) is a sectional view and (b) is a perspective view. It is a block diagram which shows the structure of the electric system of the digital single-lens reflex camera in the 1st Embodiment of this invention. 6 is a flowchart for explaining the operation of the camera in a through image mode in the first embodiment of the present invention. FIG. 9 is a cross-sectional view of a mechanism for adjusting a focusing screen according to a second embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Camera body, 11 ... Main mirror, 12 ... Cover glass, 13 ... Prism, 15 ... Mirror A (mirror (A)), 16 ... Relay system lens, 17 ... Mirror B (mirror (B)), 18 ... Mirror C (mirror (C)), 21 ... condenser lens, 22 ... separator aperture, 23 ... separator lens, 25 ... AF optical system, 27 ... AF sensor, 33 ... focal plane shutter, 34 ... low pass filter, 35 ... imager, 36 ... Imager plate, 40 ... Monitor, 45 ... Body mount, 50 ... Calculation unit, 51 ... Motor drive circuit, 52 ... Shutter mirror drive motor, 53 ... Shutter control circuit, 56 ... Photometric sensor, 57 ... Charge cam switch (SW) 58 ... Front curtain switch (SW), 60 ... Imager drive circuit, 62 ... Monitor drive circuit, 65 ... Operation button, 66 ... Operation dial, 67 ... Release switch (SW), 69 ... Recording medium, 70 ... Memory, 71 ... Image data memory, 80 ... Interchangeable lens, 81 ... Calculation unit, 82 ... Motor drive circuit, 83 ... Focus Motor, 84 ... diaphragm drive circuit, 85 ... diaphragm motor, 87 ... focus pulse counter, 88 ... zoom encoder, 90 ... memory, 100 ... screen cradle, 101 ... screen frame holding plate, 102 ... screen frame, 103 ... focusing screen DESCRIPTION OF SYMBOLS 110 ... Eyepiece unit, 111 ... Eyepiece frame, 112 ... Diopter adjustment lens, 113 ... Eyepiece glass, 115 ... Eyecup, 120 ... Finder main body.

Claims (19)

An optical path dividing means arranged in the photographing optical path and guiding a part of the subject luminous flux toward the observation optical path;
A relay optical system disposed on the observation optical path side;
A screen disposed at an imaging position of the relay optical system;
A loupe optical system for observing a subject image formed on the screen;
Comprising
A single-lens reflex camera, wherein the loupe optical system is detachable, and the position or tilt of the screen can be adjusted with the loupe optical system removed.   The single-lens reflex camera according to claim 1, wherein the screen is capable of adjusting a position of the observation optical path in an optical axis direction or an inclination of the observation optical path with respect to the optical axis. Further comprising a regulating member for regulating the position of the screen,
The single-lens reflex camera according to claim 1, wherein the adjustment is performed by changing the relative positions of the three receiving surfaces arranged on the regulating member with respect to the camera body. An optical path dividing means arranged in the photographing optical path;
A relay optical system arranged on the side of the observation optical path divided by the optical path dividing means;
A screen disposed at a position where the relay optical system forms an image;
A loupe optical system arranged at a position where the screen can be observed;
Comprising
A camera characterized in that the position of the screen in the optical axis direction and the inclination of the screen with respect to the optical axis of the observation optical path can be adjusted from the direction of the loupe optical system.   5. The camera according to claim 4, wherein the adjustment of the screen is performed by changing a relative position of the three positions arranged on a regulating member that regulates the position of the screen with respect to the camera.   The camera according to claim 4, wherein the loupe optical system is detachable.   The camera according to claim 4, wherein the screen can be adjusted with the loupe optical system removed. An image sensor disposed in the imaging optical path;
First optical path dividing means arranged in the photographing optical path;
A relay optical system disposed on the observation optical path side divided by the first optical path dividing means;
A screen disposed at a position where the relay optical system forms an image;
A second optical path splitting means disposed between the first optical path splitting means and the screen;
Ranging means arranged on the transmitted light side divided by the second optical path dividing means,
A loupe optical system arranged at a position where the screen can be observed;
Comprising
The camera characterized in that the screen can be adjusted to an equivalent position with respect to the imaging plane of the imaging device.   9. The camera according to claim 8, wherein the first and second optical path dividing means are half mirrors.   9. The camera according to claim 8, wherein the first optical path dividing means is a movable mirror.   9. The camera according to claim 8, wherein the first optical path dividing means is in a retracted state from the photographing optical path when photographing one frame, and is in a state of dividing the optical path within the photographing optical path in the through image mode.   The camera according to claim 8, wherein a cover glass is disposed at an incident position on the observation optical path side. An image sensor for imaging the image that has passed through the taking lens;
An optical path dividing means arranged in the photographing optical path for guiding the subject image to the observation optical path side;
A relay optical system disposed on the observation optical path side;
A screen disposed at an imaging position of the relay optical system;
For observing the subject image formed on the screen, a loupe optical system that is detachable from the camera body,
Comprising
A single-lens reflex camera, wherein the position or tilt of the screen can be adjusted in a state where the loupe optical system is removed from the camera body.   The single-lens reflex camera according to claim 13, wherein the screen is capable of adjusting a position of the observation optical path in an optical axis direction or an inclination of the observation optical path with respect to the optical axis. Further comprising a regulating member for regulating the position of the screen,
The single-lens reflex camera according to claim 13, wherein adjustment is performed by changing a relative position of the three receiving surfaces arranged on the regulating member with respect to the camera body. An image sensor that captures a subject image that has passed through the taking lens;
An optical path dividing means arranged in the photographing optical path;
A relay optical system arranged on the side of the observation optical path divided by the optical path dividing means;
A screen disposed at a position where the relay optical system forms an image;
A loupe optical system arranged at a position where the screen can be observed;
Comprising
A single-lens reflex camera configured to be able to adjust the position of the screen in the optical axis direction and the tilt with respect to the optical axis with respect to the optical axis of the observation optical path from the direction of the loupe optical system.   The single-lens reflex camera according to claim 16, wherein the adjustment of the screen is performed by changing a relative position of the three positions arranged on a regulating member that regulates the position of the screen with respect to the camera.   The single-lens reflex camera according to claim 16, wherein the loupe optical system is detachable from the camera body. The single-lens reflex camera according to claim 16, wherein the adjustment of the screen is performed in a state where the loupe optical system is detached from the camera body.

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