JP2008129402A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a camera for taking a photograph by selecting photography using an optical finder and live-view photography while preventing a movable mirror from being damaged because a photographic lens interferes with the movable mirror. <P>SOLUTION: The camera includes a mount means, the movable mirror provided in a photographing optical path so that it can retreat from the photographing optical path, an imaging device and a display means to display image information based on an image obtained by the imaging device. The camera is characterized in that it is equipped with a detection means to detect whether or not a part of the photographic lens interferes with the movable mirror when mounting the photographic lens on the mount means, and a control means to control based on a signal from the detection means so as to allow the movable mirror to retreat from the photographing optical path and also to allow the display means to display the image information based on the image obtained by the imaging device when the movable mirror retreats from the photographing optical path. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a camera that can be detachably mounted with various photographing lenses having different back focus and can select photographing using an optical viewfinder and live view photographing.

  In a single-lens reflex camera, a quick return mirror for guiding a light beam from a subject that has passed through the photographing lens to a finder optical system, or a sub mirror for guiding it to a focus detection device, between a photographing lens and an image sensor. A movable mirror is provided.

  The movable mirror is inclined on the optical axis of the photographing lens except during photographing when the release button is operated. The light beam from the subject passing through the photographing lens is guided to the finder optical system and the focus detection device.

  2. Description of the Related Art In recent years, a digital single-lens camera including an image sensor that captures a light beam from a subject that has passed through a photographing lens and outputs image data, and a display unit that displays an image on an LCD or the like according to the image data output from the image sensor. Many reflex cameras have been proposed.

  As a digital single-lens reflex camera, instead of observing and photographing a subject using an optical viewfinder, live view shooting is performed in which image data captured by an image sensor is displayed on a display unit and an image is captured while observing an image on the display unit. What is possible has been proposed.

  During live view shooting, the movable mirror is retracted (mirror up) from the shooting optical path. For this reason, in the case of a camera that performs only live view shooting, the space for arranging the movable mirror is not necessary.

  Since a camera that only performs live view shooting has a movable mirror in a mirror-up state, a shooting lens that is detachably attached to the camera is effective for downsizing the camera.

  When a photographic lens with a short back focus is attached to a camera having a movable mirror disposed in the photographing optical path, the movable mirror needs to be retracted from the photographing optical path (mirror up).

  At this time, it is necessary to perform mirror up on the user side (photographer side) in advance. If you forget this operation and try to attach a photographic lens with a short back focus to the camera, the movable mirror and a part of the photographic lens may come into contact with each other and the movable mirror may be damaged.

  On the other hand, a single lens reflex camera system that avoids interference between the lens barrel of the photographic lens and the movable mirror when the photographic lens is attached to the camera is known regardless of the back focus of the photographic lens. (Patent Document 1).

  In Patent Document 1, the movable mirror is positioned outside the photographing optical path in the initial setting when the camera of the photographing lens is not attached.

  Only when a photographic lens with a long back focus is attached to the camera, the movable mirror is driven so as to be positioned in the photographic optical path.

  In addition, when a photographing lens with a short back focus is attached to the camera, the movable mirror is fixed.

This operation is performed by detecting and identifying lens identification information emitted from a signal means (ROM) provided on the photographing lens by an electronic circuit on the camera side.
Japanese Patent Laid-Open No. 11-352585

  In Patent Document 1, in an initial setting, the movable mirror is retracted out of the photographing optical path. For this reason, when a photographing lens with a long back focus is attached to the camera, if the power supply on the camera side is OFF, the driving means does not move and the movable mirror does not move in the photographing optical path.

  That is, since the movable mirror remains retracted from the photographing optical path, the image cannot be observed with the optical viewfinder.

  It is an object of the present invention to provide a camera capable of observing an image with an optical viewfinder even when a camera lens with a long back focus is attached to the camera with the power source for driving the movable mirror on the camera side turned off. To do. Furthermore, the purpose is to provide a camera that can select and shoot using an optical viewfinder and live view shooting while preventing the movable mirror from interfering with the photographic lens and the movable mirror. To do.

The camera of the present invention
Mounting means for making the taking lens removable;
A movable mirror provided in the photographing optical path so as to be retractable from the photographing optical path;
An image sensor that photoelectrically converts an image formed by the taking lens;
Display means for displaying image information based on an image obtained by the image sensor;
In a camera having
Detecting means for detecting whether a part of the photographic lens interferes with the movable mirror when the photographic lens is mounted on the mount means;
Based on the signal from the detection means, the movable mirror is retracted from the photographing optical path, and when the movable mirror is retracted from the photographing optical path, image information based on an image obtained by the imaging element is displayed on the display means. Control means for controlling the display on
It is characterized by having.

In addition, the present invention
Mounting means for making the taking lens removable;
A movable mirror provided in the photographing optical path so as to be retractable from the photographing optical path;
An image sensor that photoelectrically converts an image formed by the taking lens;
Display means for displaying image information based on an image obtained by the image sensor;
In a camera having
Receiving means for receiving information from the photographic lens side whether or not a part of the photographic lens interferes with the movable mirror when the photographic lens is mounted on the mount means;
Based on the signal from the receiving means, the movable mirror is retracted from the photographing optical path, and when the movable mirror is retracted from the photographing optical path, image information based on an image obtained by the imaging element is displayed on the display means. Control means for controlling the display on
It is characterized by having.

  According to the present invention, an image can be observed with an optical viewfinder even when a camera lens with a long back focus is attached to the camera in a state where the power source for driving the movable mirror on the camera side is OFF. Furthermore, it is possible to obtain a camera that can select and shoot using an optical viewfinder and live view shooting while preventing the movable mirror from being damaged due to interference between the photographing lens and the movable mirror.

  Embodiments of a camera according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram of a main part of the first embodiment, and FIG. 2 is a block diagram of the main part of FIG. 1 and 2, reference numeral 1 denotes a first camera (imaging device).

  The housing 1a of the first camera 1 is provided with a mount 2 on which a photographic lens is detachably mounted. Further, operation buttons 3 such as a release button 3a, a power button (power switch) 3b, and a lens removal button 3c are provided. Further, display means (LCD) 4 for displaying image information photographed by the photographing lens is provided. The mount 2 is provided with an electrical contact 2a capable of exchanging various data when the photographing lens is attached.

  Inside the first camera 1, there is a main mirror (movable mirror) 5 that is in the photographing optical path and can be retracted from the optical path, a mirror drive circuit 7 connected to the rotating shaft 6 of the movable mirror 5, and a plurality of pixels. An image pickup device 8 composed of a CCD for photoelectric conversion is provided. Further, an electronic circuit (control means) 9 for controlling various operations formed on the circuit board is provided.

  Further, a finder optical system (observation system) 13 having a focusing plate 10, a penta roof prism 11, and an eyepiece 12 is provided for observing the subject image.

  In the housing 1a immediately after the mount 2, a mirror up switch (detection means) 14 is provided for detecting whether or not the movable mirror 5 is to be driven when the photographic lens is mounted.

  As shown in FIG. 1, the movable mirror 5 of this embodiment is arranged in the photographing optical path in the initial setting (mirror down). When the photographic lens is attached to the first camera 1, the back focus of the photographic lens is short, and the movable lens 5 and the movable mirror 5 do not come into contact with each other so that the movable mirror 5 is not raised (retracted from the photographic optical path). May not be. Only at this time, a part of the lens barrel of the photographic lens pushes up the mirror up switch 14.

  That is, the mirror up switch 14 is turned on.

  When the mirror up switch 14 is pressed by a part of the lens barrel of the photographing lens with the power button 3b turned on (when turned on), a control signal for raising the movable mirror 5 is sent to the mirror up switch drive circuit 15. It is sent to the mirror drive circuit 7 via the electronic circuit 9.

  The mirror drive circuit 7 receives the control signal from the electronic circuit (control means) 9 and rotates the movable mirror 5 around the rotation shaft 6 to retract the movable mirror 5 from the photographing optical path.

  Based on this, the display unit 4 is driven, and an image captured by the image sensor 8 is displayed on the display unit 4 to enable live view shooting.

  Here, when the power button 3b is OFF, even if a part of the lens barrel of the photographing lens comes into contact with the mirror up switch 14, it is locked by the mirror up switch drive circuit 15 so that it is not pressed (ON). This prevents the photographic lens from being mounted on the mount 2 so that a part of the photographic lens does not come into contact with the movable mirror 5 to prevent the movable mirror 5 from being damaged.

  Further, when the mirror up switch 14 is pushed down by a part of the lens barrel of the photographing lens, the movable mirror 5 is raised. As a result, the optical viewfinder image cannot be observed with the light reflected by the movable mirror. At this time, the display means (LCD) 4 is activated via the electronic circuit 9 so that the photographer can immediately observe the photographed image on the display means 4. This allows you to start live view shooting.

  The first camera 1 according to the present embodiment includes at least three of the first photographing lens 101 shown in FIG. 3, the second photographing lens 121 shown in FIG. 4, and the third photographing lens 141 shown in FIG. Various types of photographic lenses can be attached.

  A first photographing lens 101 shown in FIG. 3 is a photographing lens having a long back focus (for example, a back focus of 38 mm or more).

  The second photographing lens 121 shown in FIG. 4 is a photographing lens having a short back focus (for example, a back focus of 38 mm or less).

  In the third photographing lens 141 shown in FIGS. 5A and 5B, the optical system can be extended between the shortened state 141a (FIG. 5A) and the extended state 141b (FIG. 5B). . In the extended state 141b, the photographing lens has a short back focus (for example, the back focus is 38 mm or less).

  Next, the operation of the first camera 1 when the first to third photographing lenses 101, 121, 141 are attached to the first camera 1 of FIG.

  As shown in FIG. 3, when the first photographing lens 101 is attached to the first camera 1, the barrel 104 of the first photographing lens 101 does not touch the mirror up switch 14. For this reason, the movable mirror 5 remains down unless the photographer presses the release button 3a or switches to the live view shooting mode.

  As shown in FIG. 4, when the second photographing lens 121 is attached to the first camera 1, the lens barrel 124 of the second photographing lens 121 presses the mirror up switch 14 during the attachment. For this reason, the movable mirror 5 arranged in the photographing optical path is automatically retracted from the optical path. At this time, the display unit (LCD) 4 is activated to display an image obtained by the image sensor 8 on the display unit 4. This enables live view shooting.

  As shown in FIGS. 5A and 5B, the operation when the third photographing lens 141 is attached to the first camera 1 is as follows. As shown in FIG. 5A, when the photographing lens 141 is attached in the shortened state 141a, the lens barrel 144 of the photographing lens 141 moves in the optical axis direction and does not touch the mirror up switch (switch member) 14.

  For this reason, the movable mirror 5 remains mirror-down. In this state, as shown in FIG. 5B, when the photographing lens 141 is set in the extended state 141b, a part of the lens barrel 144 pushes down the mirror up switch 14.

  As a result, the movable mirror 5 is retracted from the optical path. At this time, when the display unit 4 is activated, an image obtained by the image sensor 8 is displayed on the display unit 4. This enables live view shooting.

  The photographing lens 141 may be attached to the camera 1 in the extended state 141b. The operation at this time is the same as in FIG.

  FIG. 6 is a schematic diagram of the main part of the second embodiment, and FIG. 7 is a block diagram of the main part of FIG. 6 and 7, reference numeral 21 denotes a second camera (imaging device).

  The housing 21a of the second camera 21 is provided with a mount 22 for detachably mounting the taking lens. Further, operation buttons 23 such as a release button 23a, a power button (power switch) 23b, and a lens removal button 23c are provided. Further, display means (LCD) 24 for displaying an image photographed by the photographing lens is provided. The mount 22 is provided with an electrical contact 22a capable of exchanging various data when the photographing lens is attached.

  Inside the second camera 21, there is a main mirror (movable mirror) 25 that is in the photographing optical path and can be retracted from the optical path, a mirror drive circuit 27 connected to the rotating shaft 26 of the movable mirror 25, and a plurality of pixels. An image pickup device 28 composed of a CCD is provided.

  Further, an electronic circuit (control means) 29 for controlling various operations formed on the circuit board is provided.

  Further, a finder optical system (observation system) 33 having a focus plate 30, a penta roof prism 31, and an eyepiece 32 is provided for observing the subject image.

  Here, the electrical contact 22a in the mount 22 constitutes a receiving means, and a signal relating to the type is input from the side of the photographic lens mounted via the electrical contact 22a. The type of the taking lens is determined by the electronic circuit 29 from the signal from the receiving means 22a.

  When the electronic circuit 29 determines that the imaging lens has a short back focus and should be mirror-up, the electronic circuit 29 sends a control signal for mirror-up to the mirror drive circuit 35. The mirror drive circuit 35 receives the control signal from the electronic circuit 29, rotates the movable mirror 25 around the rotation axis 26, and retracts from the photographing optical path.

  Thereafter, when the display unit 24 is activated via the electronic circuit 9, the image captured by the image sensor 28 is displayed on the display unit 24, and the photographer can immediately start live view shooting.

  As shown in FIG. 6, the movable mirror 25 of this embodiment is disposed in the photographing optical path in the initial setting (mirror down). When the photographic lens is attached to the second camera 21, the back focus of the photographic lens is short, and the lens barrel of the photographic lens and the movable mirror 25 come into contact with each other so that the movable mirror 25 is not raised (retracted from the photographic optical path). May not be. Only at this time, the electronic circuit 29 raises the movable mirror 25 based on a signal (information on whether or not to interfere with the movable mirror) sent via the electrical contact 22a.

  The second camera 21 of this embodiment can be mounted with at least two types of photographing lenses, the first photographing lens 101 shown in FIG. 8 and the third photographing lens 141 shown in FIG.

  A first photographing lens 101 shown in FIG. 8 is a photographing lens having a long back focus (for example, a back focus of 38 mm or more).

  In the third photographing lens 141 shown in FIGS. 9A and 9B, the optical system can be extended between the shortened state 141a (FIG. 9A) and the extended state 141b (FIG. 9B). . In the extended state 141b, the photographing lens has a short back focus (for example, the back focus is 38 mm or less).

  The third photographing lens 141 is in a shortened state 141a when not attached to the second camera 21. When mounted on the second camera 21, electricity is supplied from the electrical contact 22a, so that a part of the lens barrel is moved in the optical axis direction by the motor 146, and the transition to the extended state 141b becomes possible. ing.

  Next, the operation of the second camera 21 when the first and third photographing lenses 101 and 141 are attached to the second camera 21 will be described.

  As shown in FIG. 8, when the first photographing lens 101 is attached to the second camera 21, the second camera 21 moves the movable mirror 5 unless the photographer performs the release button 23a or switches to the live view photographing mode. Remains down.

  When the third photographic lens 141 is attached to the second camera 21, the electronic lens 29 is attached to the camera 21 in the shortened state 141 a as shown in FIG. 9A, and the electronic circuit 29 is connected to the photographic lens via the electrical contact 22 a of the mount 22. Determine the type.

  After the type of the photographing lens is determined by the electronic circuit 29, the movable mirror is raised, and electricity (driving force) for driving the lens barrel is supplied to the third photographing lens 141 via the electrical contact 22a.

  Then, a part of the lens barrel of the photographic lens is driven, and the photographic lens 141 is in the extended state 141b as shown in FIG. 9B.

  Based on this, the display means 24 is driven, and an image picked up by the image pickup device 8 is displayed on the display means 4 to enable live view shooting.

  FIG. 10 is a schematic diagram of the main part of the third embodiment, and FIG. 11 is a block diagram of the main part of FIG. 10 and 11, reference numeral 41 denotes a third camera (imaging device).

  The housing 41a of the third camera 41 is provided with a mount 42 for detachably mounting the taking lens. Further, operation buttons 43 such as a release button 43a, a power button (power switch) 43b, and a lens removal button 43c are provided.

  Further, display means (LCD) 44 for displaying an image photographed by the photographing lens is provided. The mount 42 is provided with an electrical contact 42a capable of exchanging various data when the photographing lens is attached.

  Inside the third camera 41, there is a main mirror (movable mirror) 45 having a half mirror surface that is in the photographing optical path and can be retracted from the optical path, and a mirror drive circuit 47 connected to the rotating shaft 46 of the movable mirror 45. Is provided. In addition, an image sensor 48 made of a CCD composed of a plurality of pixels is provided. Further, an electronic circuit (control means) 49 for controlling various operations formed on the circuit board is provided.

  Further, as a focus detection mechanism AF for detecting the focus of the photographing lens, a light receiving sensor 51 having a plurality of pixels corresponding to a plurality of focus detection positions on the image plane of the imaging optical system 50 and the photographing lens is disposed. .

  Further, for viewing the subject image, an internal LCD 52 for displaying an image obtained by the image sensor 48 and an electronic viewfinder 54 having an eyepiece 53 for enlarging and displaying the image displayed on the LCD 52 are provided.

  The light that has passed through the movable mirror 45 having the half mirror surface is always incident on the image sensor 48. Therefore, the electronic viewfinder 54 can always observe the subject image.

  Here, a mirror up switch (detecting means) 55 for detecting whether or not to drive the movable mirror 45 when the photographic lens is mounted is provided in the housing 41 a immediately after the mount 42.

  As shown in FIG. 10, the movable mirror 45 of this embodiment is disposed in the photographing optical path in the initial setting (mirror down). When the photographic lens is attached to the third camera 41, the back focus of the photographic lens is short, and the lens barrel of the photographic lens and the movable mirror 45 come into contact with each other so that the movable mirror 45 is not raised (retracted from the photographic optical path). May not be. Only at this time, a part of the lens barrel of the photographing lens presses the mirror up switch 55.

  That is, the mirror up switch 55 is turned on.

  When the mirror up switch 55 is pressed down on a part of the lens barrel of the photographing lens while the power button 43b is ON (when turned ON), it can be moved to the mirror drive circuit 47 via the mirror up switch drive circuit 56 and the electronic circuit 49. A control signal for raising the mirror 45 is sent.

  The mirror drive circuit 47 receives a control signal from the electronic circuit (control means) 49, rotates the movable mirror 45 around the rotation shaft 46, and retracts the movable mirror 45 from the imaging optical path.

  Here, when the power button 43b is OFF, even if a part of the lens barrel of the photographic lens comes into contact with the mirror up switch 55, it is locked by the mirror up switch driving circuit 56 and is not pressed down (ON). This prevents the photographic lens from being attached to the mount 42 so that a part of the photographic lens does not come into contact with the movable mirror 45 to prevent the movable mirror 45 from being damaged.

  Further, when the mirror up switch 55 is pushed down by a part of the lens barrel of the photographing lens, the movable mirror 45 is raised.

  At this time, the electronic circuit 49 in the camera is switched to the focus detection mode in which focus detection is performed based on the contrast of the image data from the image sensor 48 instead of the focus detection mechanism AF.

  The third camera 41 of the present embodiment includes at least three of the first photographing lens 101 shown in FIG. 12, the second photographing lens 121 shown in FIG. 13, and the third photographing lens 141 shown in FIG. Various types of photographic lenses can be attached.

  A first photographing lens 101 shown in FIG. 12 is a photographing lens having a long back focus (for example, a back focus of 38 mm or more).

  A second photographing lens 121 shown in FIG. 13 is a photographing lens having a short back focus (for example, a back focus of 38 mm or less).

  14A and 14B, the optical system of the third photographing lens 141 can be extended between a shortened state 141a (FIG. 14A) and an extended state 141b (FIG. 14B). . In the extended state 141b, the photographing lens has a short back focus (for example, the back focus is 38 mm or less).

  Next, the operation of the camera 1 when the first to third photographing lenses 101, 121, 141 are attached to the third camera 41 of FIG.

  As shown in FIG. 12, when the first photographing lens 101 is attached to the third camera 41, the lens barrel 104 of the first photographing lens 101 does not touch the mirror up switch 55. Therefore, the movable mirror 5 remains down unless the photographer presses the release button 43a or switches to the live view shooting mode.

  As shown in FIG. 13, when the second photographic lens 121 is attached to the third camera 41, the lens barrel 124 of the second photographic lens 121 presses the mirror up switch 55 during the attachment. For this reason, the movable mirror 45 automatically disposed in the photographing optical path is retracted from the optical path. At this time, the focus detection mode using an image obtained by the image sensor 8 is switched.

  As shown in FIGS. 14A and 14B, the operation when the third photographing lens 141 is attached to the third camera 41 is as follows. As shown in FIG. 14A, when the photographing lens 141 is mounted in the shortened state 141a, the lens barrel 144 of the photographing lens 141 does not touch the mirror up switch 55.

  For this reason, the movable mirror 45 remains mirror-down. In this state, as shown in FIG. 14B, when the photographing lens 141 is set to the extended state 141b, a part of the lens barrel 144 pushes down the mirror up switch 55.

  As a result, the movable mirror 45 is retracted from the optical path. At this time, the focus detection mode using an image obtained by the image sensor 8 is switched.

  The photographic lens 141 may be attached to the camera 41 in the extended state 141b. The operation at this time is the same as in FIG.

  FIG. 15 is a schematic diagram of the main part of the fourth embodiment, and FIG. 16 is a block diagram of the main part of FIG. 15 and 16, reference numeral 61 denotes a fourth camera (imaging device).

  The housing 61a of the fourth camera 61 is provided with a mount 62 for detachably mounting the taking lens. Further, operation buttons 63 such as a release button 63a, a power button (power switch) 63b, and a lens removal button 63c are provided. Further, a display means (LCD) 64 for displaying an image photographed by the photographing lens is provided. The mount 62 is provided with an electrical contact 62a capable of exchanging various data when the photographing lens is attached.

  Inside the fourth camera 61 is a main mirror (movable mirror) 65 that is in the photographing optical path and can be retracted from the optical path, a mirror drive circuit 67 connected to the rotating shaft 66 of the movable mirror 65, and a plurality of pixels. An image sensor 68 made of a CCD is provided. In addition, an electronic circuit (control means) 69 for controlling various operations formed on the circuit board is provided.

  Further, as a focus detection mechanism AF for detecting the focus of the photographing lens, a light receiving sensor 71 including a plurality of pixels corresponding to a plurality of focus detection positions on the image plane of the imaging optical system 70 and the photographing lens is disposed. .

  Further, for viewing the subject image, an internal LCD 72 for displaying an image obtained by the image sensor 68 and an electronic viewfinder 74 having an eyepiece 73 for displaying an enlarged image displayed on the LCD 72 are provided.

  Here, a signal relating to the type is input from the photographic lens mounted via the electrical contact 62 a constituting the receiving means in the mount 62. Based on the signal from the receiving means 62a, the electronic circuit 69 determines the type of the taking lens.

  When the electronic circuit 69 determines that the photographing lens has a short back focus to be mirrored up, the electronic circuit 69 sends a control signal for mirroring up to the mirror driving circuit 75.

  The mirror drive circuit 75 receives the control signal from the electronic circuit 69, rotates the movable mirror 65 around the rotation axis 66, and retracts from the photographing optical path. Thereafter, the electronic circuit 69 in the fourth camera 61 switches to the focus detection mode in which focus detection is performed based on the contrast of the image data from the image sensor 48 instead of the focus detection mechanism AF.

  As shown in FIG. 15, the movable mirror 65 of this embodiment is disposed in the photographing optical path in the initial setting (mirror down).

  When the photographic lens is attached to the fourth camera 61, the back focus of the photographic lens is short, and the lens barrel of the photographic lens and the movable mirror 65 are in contact with each other so that the movable mirror 65 is not raised (retracted from the photographic optical path). May not be. Only at this time, the electronic circuit 69 raises the movable mirror 65 based on a signal sent via the electrical contact 65a.

  The fourth camera 61 of this embodiment can be mounted with at least two types of photographing lenses, the first photographing lens 101 shown in FIG. 17 and the third photographing lens 141 shown in FIG.

  A first photographing lens 101 shown in FIG. 17 is a photographing lens having a long back focus (for example, a back focus of 38 mm or more).

  In the third photographing lens 141 shown in FIGS. 18A and 18B, the optical system can be extended between the shortened state 141a (FIG. 18A) and the extended state 141b (FIG. 18B). . In the extended state 141b, the photographing lens has a short back focus (for example, the back focus is 38 mm or less).

  Further, the third photographing lens 141 is in the shortened state 141 a when not attached to the fourth camera 61. When mounted on the fourth camera 61, electricity is supplied from the electrical contact 62a, so that a part of the lens barrel is driven by the motor 146 and the transition to the extended state 141b is possible.

  Next, the operation of the fourth camera 61 when the first and third photographing lenses 141 and 144 are attached to the fourth camera 61 will be described.

  As shown in FIG. 17, when the first photographing lens 101 is attached to the fourth camera 61, the movable mirror 65 of the camera 61 remains down unless the photographer presses the release button 63a.

  When the third camera lens 141 is mounted on the fourth camera 61, the camera lens 61 is mounted in the shortened state 141b as shown in FIG. 18A, and the electronic circuit 69 is connected to the camera lens 62 through the electrical contact 62a of the mount 62. Determine the type. After the type of the taking lens is determined by the electronic circuit 69, the movable mirror is moved up, and electricity (driving force) to drive a part of the lens barrel is supplied to the third taking lens 141 through the electrical contact 62a. Is done.

  Then, a part of the lens barrel of the photographing lens 141 is driven, and the photographing lens 141 is in the extended state 141b as shown in FIG.

  Based on this, the electronic circuit 69 switches to the focus detection mode in which focus detection is performed based on the contrast of the image data from the image sensor 68 instead of the focus detection mechanism AF.

  In each of the above-described embodiments, Table 1 shows the relationship between each camera, a photographic lens that can be mounted on the camera, a detection unit that detects whether or not the movable mirror should be driven, or a reception unit that receives the finder. .

  In Table 1, OVF is an optical viewfinder, and EVF is an electronic viewfinder.

  In each of the above embodiments, the detection means by pressing the switch and the reception means by communication from the electrical contact of the mount are described as means for detecting the mounting of the photographing lens that interferes with the movable mirror. You may change to the communication means by wireless communication between.

  As described above, in each embodiment, when a photographing lens with a short back focus is attached to a camera, the movable mirror is retracted from the photographing optical path to prevent interference with the movable mirror.

  At this time, live view shooting can be performed using image data obtained by the image sensor.

  When a camera lens with a long back focus is attached to the camera, that is, when it is not necessary to retract the movable mirror from the imaging optical path, the subject image can be captured with the optical viewfinder or electronic viewfinder even when the power for driving the movable mirror is turned off. Can be observed.

Sectional drawing of the 1st camera of Example 1 of this invention 1 is a block diagram showing an electrical configuration of a first camera according to a first embodiment of the present invention. Sectional drawing when the first lens is attached to the first camera according to the first embodiment of the present invention. Sectional drawing when the second lens is attached to the first camera according to the first embodiment of the present invention. (A) Sectional view when the third lens in the shortened state is attached to the first camera of Example 1 of the present invention. (B) The first camera in the expanded state of the first camera of Example 1 of the present invention. Sectional view when lens 3 is attached Sectional drawing of the 2nd camera of Example 2 of this invention FIG. 6 is a block diagram showing an electrical configuration of a second camera according to the second embodiment of the present invention. Sectional drawing when the first lens is attached to the second camera according to the second embodiment of the present invention. (A) Sectional view when the third lens in the shortened state is attached to the second camera of the second embodiment of the present invention (b) The second camera in the extended state of the second camera of the second embodiment of the present invention Sectional view when lens 3 is attached Sectional drawing of the 3rd camera of Example 3 of this invention FIG. 6 is a block diagram showing an electrical configuration of a third camera according to the third embodiment of the present invention. Sectional drawing when attaching the first lens to the third camera of Example 3 of the present invention Sectional drawing when the second lens is attached to the third camera according to the third embodiment of the present invention. (A) Sectional view when the third lens in the shortened state is attached to the third camera of the third embodiment of the present invention (b) The third camera in the expanded state of the third camera of the third embodiment of the present invention Sectional view when lens 3 is attached Sectional drawing of the 4th camera of Example 4 of this invention FIG. 9 is a block diagram showing an electrical configuration of a fourth camera according to the fourth embodiment of the present invention. Sectional drawing when attaching the first lens to the fourth camera of Example 4 of the present invention (A) Sectional view when the third lens in the shortened state is attached to the fourth camera of Example 4 of the present invention. (B) The fourth camera in the expanded state of the fourth camera of Example 4 of the present invention. Sectional view when lens 3 is attached

Explanation of symbols

1, 21, 41, 61 Camera 2, 22, 42, 62 Camera side mount 4, 24, 44, 64 LCD
5,25 Main mirror 6,26 Main mirror rotation axis 7, 27, 47, 67 Mirror drive circuit 8, 28, 48, 68 CCD image sensor 9, 29, 49, 69 Electronic circuit in camera 13, 33 Viewfinder optical system 14 , 55 Mirror up switch 15, 56 Mirror up switch drive circuit 45, 65 Half mirror 46, 66 Half mirror rotation axis 54, 74 Electronic viewfinder 101, 121, 141 a, 141 b Shooting lens 102, 122, 142 Shooting optical system 104, 124,144 Lens tube 105,125,145 Lens side mount

Claims (7)

Mounting means for making the taking lens removable;
A movable mirror provided in the photographing optical path so as to be retractable from the photographing optical path;
An image sensor that photoelectrically converts an image formed by the taking lens;
Display means for displaying image information based on an image obtained by the image sensor;
In a camera having
Detecting means for detecting whether a part of the photographic lens interferes with the movable mirror when the photographic lens is mounted on the mount means;
Based on the signal from the detection means, the movable mirror is retracted from the photographing optical path, and when the movable mirror is retracted from the photographing optical path, image information based on an image obtained by the imaging element is displayed on the display means. Control means for controlling the display on
A camera characterized by comprising:   The detection means may be one of the lens barrels of the photographic lens when the photographic lens is attached to the mount means or when a part of the lens barrel of the photographic lens moves in the optical axis direction after being attached. The camera according to claim 1, further comprising a switch member that detects that the back focus of the photographing lens is short due to contact of a portion.   3. The camera according to claim 1, further comprising an optical viewfinder for observing an image formed by the light reflected by the movable mirror. Mounting means for making the taking lens removable;
A movable mirror provided in the photographing optical path so as to be retractable from the photographing optical path;
An image sensor that photoelectrically converts an image formed by the taking lens;
Display means for displaying image information based on an image obtained by the image sensor;
In a camera having
Receiving means for receiving information from the photographic lens side whether or not a part of the photographic lens interferes with the movable mirror when the photographic lens is mounted on the mount means;
Based on the signal from the receiving means, the movable mirror is retracted from the photographing optical path, and when the movable mirror is retracted from the photographing optical path, image information based on an image obtained by the imaging element is displayed on the display means. Control means for controlling the display on
A camera characterized by comprising:   5. The camera according to claim 4, wherein the receiving means has an electrical contact provided on the mounting means, and receives a signal sent from the photographing lens side via the electrical contact.   The control means, based on a signal from the receiving means, moves a part of the lens barrel of the photographing lens in the optical axis direction after retracting the movable mirror from the photographing optical path. 4 cameras.   The camera according to claim 4, 5 or 6, wherein the movable mirror includes a half mirror surface, and has an electronic viewfinder for observing an image obtained by the image pickup device through the half mirror surface.