JP2009037132A - Single-lens reflex camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a single-lens reflex camera that has a simple constitution, has high responsiveness to switching between an exposure state and non-exposure state to an imaging element, and can also shield the light coming from a finder optical system. <P>SOLUTION: This single-lens reflex camera comprises the imaging element; a photographic optical system for generating a subject image on the light-receiving surface of the imaging element, a finder optical system consisting of a screen 5, a penta prism 6, and an eyepiece; a reflecting unit 2 sliding between an observation position (A), where a subject light flux having passed the photographing optical system is reflected by a reflecting surface of a main mirror 12 and is guided to the finder optical system and an evacuating position (B), where retreat from the optical axis of the finder optical system is allowed and the light flux is allowed to be incident on the light-receiving surface so that it crosses the optical axis of the finder optical system while the angle of the reflecting surface is kept; and a light-shielding film unit 17 for shielding the incident light from the finder optical system, in interlock with the sliding of the reflecting unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a structure of a single-lens reflex camera that captures a subject image using an image sensor.

  Conventionally, as a configuration of a normal single-lens reflex camera which is an imaging device using an imaging element, for example, disclosed in Patent Document 1 or the like, an optical axis of a photographic lens as shown in an arrangement diagram showing a main configuration in FIG. (O) A photographic lens 101 that can be attached and detached along the top, a movable mirror 102 formed of a half mirror including a sub mirror 102a, a shutter 103, and an image sensor 104 are arranged, and further, a screen is located above the optical axis. A finder optical system composed of 105, a pentaprism 106, and an eyepiece lens 107 is disposed, and an AF sensor unit 108 is disposed below the optical axis.

The movable mirror 102 is supported by a mirror shaft 102b extending left and right along a plane orthogonal to the optical axis and biased by a spring so as to be able to be opened and closed. Sometimes it is driven to rotate to an optical path entrance position (position in the imaging device non-exposure state) inclined in the imaging optical path, and is driven to rotate to a retracted position (position in the imaging device exposure state) retracted from the imaging optical path during exposure. When the movable mirror 102 is in the retracted position, the screen 105 is held in a light-shielded state. Therefore, unnecessary light entering from the viewfinder unit side in the exposure state is shielded by the movable mirror 102.
JP-A 61-46941

  However, in the conventional single-lens reflex camera, the rotational driving speed of the movable mirror 102 itself is limited, and the continuous shooting speed in high-speed continuous shooting is limited. In recent years, an image sensor capable of high-speed processing capable of continuous shooting at 10 frames / second or more has been developed, and it is considered difficult to cope with such an image sensor using the conventional movable mirror driving mechanism.

  In addition, the response operation when turning from the retracted position to the optical path entry position is delayed. More specifically, a bouncing occurs because the movable mirror stops suddenly, and it is difficult to quickly shift to the finder observation state or to start the AF process immediately after switching.

  Considering a structure that employs a movable mirror other than the oscillating type as a camera capable of high-speed continuous shooting as described above, there arises a problem that unnecessary light incident from the viewfinder optical system cannot be blocked.

  The present invention has been made in order to solve the above-described problems, has a simple configuration, has quick response to switching between an exposure state and an non-exposure state of an image sensor, and is from a finder optical system. An object of the present invention is to provide a single-lens reflex camera that can also block incident light.

  A single-lens reflex camera according to claim 1 of the present invention is an image sensor, a photographing optical system that generates a subject image related to a subject light beam incident on a light receiving surface of the image sensor, and a finder optical that forms the subject image on a finder. System, a first position for reflecting the subject luminous flux that has passed through the photographing optical system by a reflecting surface and guiding it to the finder optical system, and retreating from the optical axis of the finder optical system, so that the subject luminous flux is reflected on the light receiving surface. The reflection unit that slides along the direction crossing the optical axis of the finder optical system while keeping the angle of the reflection surface between the second position where incidence is possible and the slide of the reflection unit are linked. And a light shielding curtain unit that blocks incident light from the finder optical system.

  The single-lens reflex camera according to claim 2 of the present invention is the single-lens reflex camera according to claim 1, wherein the light-shielding curtain unit includes a first movable light-shielding curtain and a second movable curtain on both sides of the slide direction with the reflection unit interposed therebetween. The movable light shielding curtain is provided, and either the first or second movable light shielding curtain is disposed at the light shielding position in accordance with the sliding direction of the reflection unit.

  The single-lens reflex camera according to claim 3 of the present invention is the single-lens reflex camera according to claim 1, wherein the light-shielding curtain unit is folded when the reflection unit is in the first position, and is in the second position. Expands as it moves.

  The single-lens reflex camera according to claim 4 of the present invention is the single-lens reflex camera according to claim 1, wherein the light-shielding curtain unit is caught when the reflection unit is in the first position, and is in the second position. Expands as it moves.

  According to the present invention, an imaging apparatus having a simple configuration, quick response to switching between an exposure state and a non-exposure state of an image sensor, and also capable of shielding unnecessary light incident from a finder optical system. Can be provided.

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

  1 and 2 are arrangement views viewed from the side of the optical axis showing the main configuration of the single-lens reflex camera according to the first embodiment of the present invention. FIG. 1 shows the finder observation / AF distance measurement state of the camera. FIG. 2 shows the image sensor exposure state of the camera. 3 and 4 are front views showing the operation state of the reflection unit and the light-shielding curtain unit applied to the single-lens reflex camera. FIG. 3 shows the viewfinder observation / AF distance measurement state, and FIG. Indicates the state. FIG. 5 is a perspective view of the imaging unit exposure state around the reflection unit and the light shielding curtain unit.

  The single-lens reflex camera 10 according to the present embodiment includes a photographic lens 1 that can be attached to and detached from a camera body (not shown) as shown in FIGS. A reflection unit 2 and a light shielding curtain unit 17, a shutter unit 3, and an image sensor 4 which are arranged along a lens optical axis (indicated by “O” in the drawing) which is an optical axis of the photographing optical system in order from Furthermore, a finder optical system, which will be described later, is disposed above the lens optical axis, an AF sensor unit 8 as a detector disposed below the lens optical axis, a control unit 9, and a reflection unit / light-shielding curtain. A unit drive mechanism is provided.

  The photographing lens 1 is a photographing optical system that takes in a subject light flux and forms an image of the subject on the light receiving surface 4 a of the image sensor 4.

  The finder optical system includes a screen 5 disposed above the finder optical axis at a position above the lens optical axis, a pentaprism 6 disposed above the screen 5, and a pentaprism 6. It consists of an eyepiece 7 arranged behind. An AE photometric sensor unit (not shown) is disposed in the vicinity of the eyepiece.

  The AF sensor unit 8 has an AF distance measuring sensor for detecting a focus state of a subject image that is an optical characteristic of the captured subject light flux.

  The reflection unit 2 is fixedly supported on a mirror frame 11 and a main mirror 12 that is held by the mirror frame and reflects the subject light flux in the finder optical axis direction, and on the back side of the half mirror portion at the center of the main mirror. The sub-mirror 13 reflects a part of the subject luminous flux to the AF sensor unit 8 side. The mirror frame 11 is supported so as to be slidable in the X direction along the guide shafts 14a and 14b by a reflection unit / light-shielding curtain unit drive mechanism described later.

  The X direction is a horizontal (−, +) direction intersecting the lens optical axis.

  The light-shielding curtain unit 17 is made of a thin plate-like light-shielding plate and has guide pins 17a and 17b at both ends. The guide pins 17a and 17b slide in guide grooves 18a of the light-shielding curtain unit guide member 18 described later. It is inserted in a movable manner. The light shielding curtain unit 17 is driven in conjunction with the reflection unit 2 via the link 16.

  As shown in FIGS. 3 and 4, the reflection unit / light-shielding curtain unit driving mechanism is disposed in a state along the X direction obliquely up and down with the lens optical axis in between, and slidably supports the mirror frame 11. A pair of guide shafts 14a and 14b, a light-shielding curtain unit guide member 18 having a shape bent in an L shape and provided with a guide groove 18a, and a member for slidingly driving the mirror frame 11 in the X direction. And a member for slidingly driving the swing arm 15 and the light-shielding curtain unit 17 whose one end side is swingably supported on the camera body side and whose other end side is supported by the mirror frame 11. A link 16 whose side is swingably supported on the mirror frame 11 side and whose other end is rotatably supported by the light-shielding curtain unit 17, and a reflection unit drive motor 19 for swingingly driving the swing arm 15. It consists of. The L-shaped corner portion 18b of the light shielding curtain unit guide member 18 is bent at a predetermined curvature so that the guide pins 17a and 17b can move smoothly.

  The light-shielding curtain unit guide member 18 is disposed along a plane parallel to the pair of guide shafts 14a and 14b.

  The reflection unit 2 is driven by the drive motor 19 via the reflection unit / light-shielding curtain unit drive mechanism, and maintains a state where it is inclined at a predetermined angle with respect to the lens optical axis while being guided by the guide shafts 14a and 14b. The main mirror 12 is the finder observation position (A) (FIGS. 1 and 3), which is the first position on the + X side lens optical axis, and the second position retracted from the −X side lens optical axis. It slides to the retracted position (B) (FIGS. 2 and 4). When the main mirror 12 is in the finder observation position (A), the subject light beam is reflected upward by the main mirror 12 and reaches the screen 5. Part of the subject luminous flux passes through the half mirror portion of the main mirror 12, is reflected by the sub mirror 13, and enters the AF sensor portion 8. When the main mirror 12 is in the retracted position (B), the subject luminous flux passes through the open shutter unit 3 and reaches the light receiving surface 4 a of the image sensor 4.

  The light-shielding curtain unit 17 is driven in conjunction with the reflection unit 2, and when the main mirror 12 is at the finder observation position (A), the light-shielding curtain unit 17 is moved from the lower side of the screen 5 to the retracted position (C) retracted from the lens optical axis side. (Figs. 1 and 3). In this state, the subject luminous flux is reflected by the main mirror 12 and reaches the screen 5 without being blocked by the light shielding curtain unit 17. When the main mirror 12 of the reflection unit 2 moves to the retracted position (B), the guide pin 17a is driven via the link 16, and the light shielding curtain unit 17 is guided by the guide groove 18a of the light shielding curtain unit guide member 18, It moves to the light shielding position (D) below the screen 5 (FIGS. 2 and 4). In this state, unnecessary light that enters from the eyepiece lens 7 of the finder optical system and reaches the screen 5 through the pentaprism 6 is cut by the light-shielding curtain unit 17 and is prevented from entering the photographing optical path.

  The control unit 9 takes in the first and second stage operation signals of a release switch (not shown), and controls the position of the reflection unit 2 by controlling the drive motor 19 based on the operation signal. Control of switching between the finder observation and ranging state and the image sensor exposure state is performed by the moving operation. In the exposure state, the imaging device 4 captures an imaging signal of the subject image by the subject luminous flux and controls the imaging process.

  In single-shooting with the single-lens reflex camera 10 of the present embodiment having the above-described configuration, each operation is controlled under the control of the control unit 9. First, the reflecting unit 2 is moved when the power is turned on, and the main mirror is moved. 12 is moved to the finder observation position (A) on the lens optical axis, and the light-shielding curtain unit 17 is retracted from the lower side of the screen 5 to the retreat position (C) on the side of the lens optical axis (FIGS. 1 and 3). In this state, the subject luminous flux incident through the photographing lens 1 is reflected by the main mirror 12, reaches the screen 5 without being shielded by the light shielding curtain unit 17, and observes the subject image by the optical finder via the pentaprism 6 and the eyepiece 7. Is possible.

  A part of the subject luminous flux that has passed through the main mirror 12 in the state where the main mirror 12 is at the viewfinder observation position (A) by the first stage operation of the release switch (not shown) is reflected by the sub mirror 13, and the AF sensor unit 8. And a ranging signal is detected. The taking lens 1 is focused based on the distance measurement signal.

  Subsequently, the drive motor 19 is rotationally driven by the second stage operation of the release switch, and the mirror frame 11 of the reflection unit 2 is slid in the -X direction to move the main mirror 12 to the retracted position (B). The light shielding curtain unit 17 is moved to the light shielding position (D) below the screen 5 (FIGS. 2 and 4). The subject luminous flux passes through the shutter unit 3 and forms an image on the light receiving surface 4a of the image pickup device 4, and exposure of the image pickup device 4 is started. In this state, unnecessary light entering from the finder optical system is blocked by the light shielding curtain unit 17 and does not enter the photographing optical path.

  An image signal from the image sensor 4 is recorded in a storage medium (not shown) such as a medium after image processing. After the exposure is completed, the reflection unit 2 is slid in the + X direction, the main mirror 12 is again returned to the finder observation position (A), and the light shielding curtain unit 17 is also returned to the retracted position (C) on the side of the lens optical axis. (FIGS. 1 and 3).

  Similarly, in the continuous shooting by the single-lens reflex camera of this embodiment, the control of each operation is executed under the control of the control unit 9. First, when the first stage operation of the release switch is performed, the above-described single shooting is performed. In the same manner as described above, the AF sensor unit 8 performs distance measurement while the main mirror 12 is at the viewfinder observation position (A), and the photographing lens 1 is focused.

  Subsequently, the reflection unit drive motor 19 is driven forward and backward by the second stage operation of the release switch, and the main mirror 12 is moved from the viewfinder observation position (A) to the retracted position (B) according to the continuous shooting speed (frame / second). The slide movement in between is repeated. During continuous shooting, every time the main mirror 12 reaches the finder observation position (A), a ranging signal from the AF sensor unit 8 is detected. Observation with a finder is also possible in a flickering state. Each time the main mirror 12 moves to the retracted position (B), the light-shielding curtain unit 17 moves to the light-shielding position (D) below the screen 5 to prevent unnecessary light from entering the photographing optical path from the finder optical system. Is done. In this state, the subject luminous flux reaches the light receiving surface 4 a of the image sensor 4, forms an image, and exposure for continuous shooting by the image sensor 4 is executed.

  The image pickup signal of the image pickup device 4 is subjected to image processing, and sequentially recorded on a medium or the like as a continuous shot image signal. At that time, live view display is also possible. When the release switch is released, the reflection unit 2 is stopped in a state where the main mirror 12 is returned to the viewfinder observation position (A), and the continuous shooting is finished.

  According to the single-lens reflex camera 10 of the present embodiment described above, the reflection unit 2 that is slidable in the X direction is used instead of the oscillating movable mirror 102 applied in the conventional single-lens reflex camera 100 shown in FIG. Since it is adopted, the reflection unit 2 can be accommodated in a narrow space in the optical axis direction of the lens in the optical path of the subject light flux. When the main mirror 12 of the reflection unit 2 is in the retracted position, the light-shielding curtain unit 17 is moved below the screen 5, and unnecessary light from the viewfinder side to the imaging optical path side is blocked. No good imaging signal can be obtained. At the same time, the main mirror 12 and the sub-mirror 13 are slid in a state where the inclination angle is constant, so that they are not affected by the bounce of the mirror even when stopped including the moving state, and are quickly switched to the optical finder observation state. In addition, AE photometry and AF distance measurement can be performed, and at the same time, the switching response to the exposure state of the image sensor 4 is also accelerated. Also, during continuous shooting, since the switching response is fast as described above, the continuous shooting speed can be increased.

Next, the single-lens reflex camera of 2nd embodiment of this invention is demonstrated using FIGS.
FIGS. 6 to 8 are front views showing the main configurations of the reflection unit and the light-shielding curtain unit in the single-lens reflex camera of this embodiment in each operation state, and FIGS. 6 and 8 show the viewfinder observation / AF distance measurement of the camera. FIG. 7 shows the image sensor exposure state of the camera.

  The single-lens reflex camera of this embodiment differs from the single-lens reflex camera 10 of the first embodiment only in the configuration of the reflection unit and the light-shielding curtain unit, and the other configurations are the same. The same components are denoted by the same reference numerals, and only different configurations will be described below.

  The single-lens reflex camera of this embodiment has one reflection unit 30 and a pair of light shielding curtain units 37 and 38 that are slid by a reflection unit / light shielding curtain unit drive mechanism.

  As shown in FIGS. 6 to 8, the reflection unit 30 includes a mirror frame 31, a main mirror 32 that is held by the mirror frame and reflects the subject light beam in the direction of the viewfinder optical axis, and a half mirror section at the center of the main mirror. And a sub mirror 33 that is fixedly supported on the back surface side of the lens and reflects a part of the subject light flux to the AF sensor unit 8 side. The mirror frame 31 is supported so as to be slidable in the X direction along the guide shafts 34a and 34b by a reflection unit / light-shielding curtain unit drive mechanism described later.

  The light shielding curtain units 37 and 38 constitute first and second movable light shielding curtains having a thin plate shape, and have guide pins 37a and 37b and 38a and 38b at both ends. The guide pins 37a, 37b, 38a, 38b are slidably fitted into guide grooves 39a of a light shielding curtain unit guide member 39 of a reflection unit / light shielding curtain unit driving mechanism section described later. The light shielding curtain units 37 and 38 are driven in conjunction with the reflection unit 30 via the links 35 and 36, respectively.

  As shown in FIGS. 6 to 8, the reflection unit / light-shielding curtain unit drive mechanism section is disposed along the X direction obliquely up and down with the lens optical axis in between, and slidably supports the mirror frame 31. A guide shaft 34a, 34b, a light-shielding curtain unit guide member 39 having a shape bent in an L-shape and provided with a guide groove 39a, and a member for slidingly driving the light-shielding curtain units 37, 38, One end side is swingably supported on the mirror frame 31 side, and the other end side is rotatably supported by the light-shielding curtain units 37 and 38, and the reflection unit 30 is slid through a wire or the like. And a reflection unit drive motor 29. The L-shaped corner 39b of the light shielding curtain unit guide member 39 is bent at a predetermined curvature so that the guide pins 37a, 37b and 38a, 38b can move smoothly. The light shielding curtain unit guide member 39 is disposed along a plane parallel to the pair of guide shafts 34a and 34b.

  The reflection unit 30 is driven by the reflection unit drive motor 29 via the reflection unit / light-shielding curtain unit drive mechanism, and the finder observation position, which is the first position on the lens optical axis, where the main mirror 32 is the center in the X direction. (E) (FIG. 6) and the retracted position (F) (FIG. 7), which is the second position retracted from the + X side lens optical axis, or the second retracted from the −X side lens optical axis. Between the retracted position (G) (FIG. 8), which is the position of the lens, while maintaining a state inclined at a predetermined angle with respect to the lens optical axis.

  The light-shielding curtain units 37 and 38 are driven in conjunction with the reflection unit 30, and when the main mirror 32 is at the finder observation position (E), the retreat is retracted from the lower side of the screen 5 in the -X direction or the + X direction. It is in the position (H) or (K) (FIG. 6).

  When the main mirror 32 moves to one retracted position (F), the guide pins 37a and 38a are driven via the links 35 and 36, and the one light-shielding curtain unit 37 is guided by the guide groove 39a of the guide member 39 to be screened. It moves to the light shielding position (I) below 5 (FIG. 7). The other light-shielding curtain unit 38 is guided by the guide groove 39a of the guide member 39 and moves to the retracted position (M) outside the main mirror 32 at the retracted position (F) (FIG. 7).

  Similarly, when the main mirror 32 moves to the other retracted position (G), the guide pins 37a and 38a are driven via the link 16, and the one light shielding curtain unit 37 is guided by the guide groove 39a of the guide member 39 and retracted. It moves to the retracted position (J) outside the main mirror 32 at the position (G) (FIG. 8). The other light shielding curtain unit 38 is guided by the guide groove 39a of the guide member 39 and moves to the light shielding position (L) below the screen 5 (FIG. 8).

  In the single shooting operation of the single-lens reflex camera of the present embodiment having the above-described configuration, each operation is controlled under the control of the control unit 9 as in the single-lens reflex camera 10 of the first embodiment. When the power is turned on, the reflection unit 30 is driven, and the main mirror 32 is moved to the viewfinder observation position (E) on the lens optical axis (FIG. 6). Further, the light shielding curtain units 37 and 38 move to the retracted position (H) or (K). In this state, the subject luminous flux incident through the photographing lens 1 and reflected by the main mirror 32 reaches the screen 5 side without being blocked by the light shielding curtain units 37 and 38, and passes through the pentaprism 6 and the eyepiece 7 to the optical viewfinder. It is possible to observe the subject image.

  A part of the subject luminous flux transmitted through the main mirror while the main mirror 32 is in the viewfinder observation position (E) by the first stage operation of a release switch (not shown) is reflected by the sub mirror 33, and the AF sensor unit 8 and a ranging signal is detected. The taking lens 1 is focused based on the distance measurement signal.

  Subsequently, the drive motor 29 is driven by the second stage operation of the release switch, and the mirror frame 31 of the reflection unit 30 is slid in the + X direction or the −X direction to move the main mirror 32 to the retracted position (F), Or move to (G) (FIGS. 7 and 8). When the main mirror 32 moves to the retracted position (F), the light-shielding curtain unit 37 moves to the light-shielding position (I) below the screen 5 and the light-shielding curtain unit 38 retracts to the side of the main mirror 32 (M). Move to. When the main mirror 32 moves to the retracted position (G), the light-shielding curtain unit 38 moves to the light-shielding position (L) below the screen 5 and the light-shielding curtain unit 37 moves to the side retracted position ( Go to J). In any state, unnecessary light from the finder optics is shielded by the light shielding curtain units 37 and 38 and does not enter the photographing optical path. Then, the subject light flux passes through the shutter unit 3 and forms an image on the light receiving surface 4a of the image pickup device 4, and exposure of the image pickup device 4 is started.

  An image signal from the image sensor 4 is recorded in a storage medium (not shown) such as a medium after image processing. After the exposure is finished, the reflection unit 30 is driven to slide in the −X direction or the + X direction, the main mirror 32 is returned to the viewfinder observation position (E) again, and the light-shielding curtain units 37 and 38 are in the retracted position (H). Or (K) (FIG. 6).

  Further, in the continuous shooting operation by the single-lens reflex camera of the present embodiment, each operation is similarly controlled under the control of the control unit 9. First, when the first-stage operation of the release switch is performed, distance measurement is performed by the AF sensor unit 8 with the main mirror 32 being at the viewfinder observation position (E) as in the case of the single shooting described above, and the taking lens 1 Focusing is performed.

  Subsequently, the reflection unit drive motor 29 is rotated in the forward and reverse directions by the second stage operation of the release switch, and the main mirror 32 is moved away from the viewfinder observation position (E) according to the continuous shooting speed (frame / second) ( F) Further, the slide movement from the retracted position (G) to the finder observation position (E) is repeated again through the finder observation position (E). In conjunction with the reflection unit 30, the light shielding curtain unit 37 moves to the retracted position (H), the light shielding position (I), the retracted position (H), the retracted position (J), and the retracted position (H). 38 also moves to the retracted position (K), retracted position (M), retracted position (K), light shielding position (L), and retracted position (K).

  Every time the main mirror 32 reaches the viewfinder observation position (E), a distance measurement signal by the AF sensor unit 8 is detected. Observation with a finder is also possible in a flickering state. Each time the main mirror 32 moves to the retracted position (F) or (G), the light-shielding curtain units 37 and 38 are located at the light-shielding position (I) or (L), which is unnecessary from the finder optical system. Light is prevented from entering the photographing optical path.

  Therefore, exposure for continuous shooting by the image sensor 4 is executed, and the image signals subjected to image processing are sequentially recorded in a storage medium such as a medium. When the release switch is released, continuous shooting is terminated, the main mirror 32 is returned to the viewfinder observation position (E), and the light-shielding curtain units 37 and 38 are returned to the retracted positions (H) and (K). The unit 30 and the light shielding curtain units 37 and 38 are stopped.

  According to the single-lens reflex camera of the present embodiment described above, in place of the oscillating movable mirror 102 applied to the conventional single-lens reflex camera 100 shown in FIG. 11 as in the case of the first embodiment described above. By adopting the reflection unit 30 that is slidable in the X direction, either the light shielding curtain unit 37 or 38 moves below the screen 5 when the main mirror 32 of the reflection unit 30 is in the retracted position. In addition, since unnecessary light from the viewfinder side to the imaging optical path side is shielded, a good imaging signal that is not affected by the unnecessary light can be obtained. At the same time, since the main mirror 32 and the sub mirror 33 slide and move with a constant tilt angle, there is no influence of the bounce of the mirror even during stoppage, including during movement, and quickly switches to the optical finder observation state. AF distance measurement can be performed, and at the same time, the switching response to the exposure state of the image sensor 4 is accelerated.

  Further, at the time of continuous shooting, it is not necessary to swing the movable mirror as in the conventional single-lens reflex camera 100 described above, it is only necessary to slide the main mirror 32 and the sub mirror 33, and a bounce phenomenon occurs. Therefore, quick ranging is possible, for example, high-speed continuous shooting at 10 frames / second or more is possible. In particular, it is not always necessary to stop the main mirror 32 at the finder observation position (E) by providing a margin in the X-direction width of the main mirror 32 and the sub mirror 33, and optical finder observation and distance measurement can be performed while the mirror is moving. It becomes. Similarly to single-shot shooting characters, during the exposure of the image sensor during continuous shooting, unnecessary light from the viewfinder side to the imaging optical path side is shielded by the light-shielding curtain units 37 and 38, so that the unnecessary light is not affected. An imaging signal can be obtained.

Next, a single-lens reflex camera according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 9 is a front view showing the main configuration of the reflection unit and the light shielding curtain unit in the single-lens reflex camera of this embodiment, and shows the viewfinder observation / AF distance measurement state and the image sensor exposure state.

  The single-lens reflex camera of this embodiment differs from the single-lens reflex camera 10 of the first embodiment only in the configuration of the reflection unit and the light-shielding curtain unit, and the other configurations are the same. The same components are denoted by the same reference numerals, and only different configurations will be described below.

  The single-lens reflex camera of this embodiment has a pair of a reflection unit 40 and a light shielding curtain unit 45 that are slid by a reflection unit / light shielding curtain unit drive mechanism.

  As shown in FIG. 9, the reflection unit 40 includes a mirror frame 41, a main mirror 42 that is held by the mirror frame and reflects the subject light beam in the finder optical axis direction, and the back surface of the center half mirror portion of the main mirror. And a sub-mirror 43 that is fixedly supported on the side and reflects a part of the subject light flux to the AF sensor unit 8 side. The mirror frame 41 is supported so as to be slidable in the X direction along the guide shafts 44a and 44b by a reflection unit / light-shielding curtain unit drive mechanism described later.

  The light-shielding curtain unit 45 is formed by connecting a plurality of thin flat plate-shaped light-shielding sheets 45a, 45b, 45c,... That can be folded and housed, a support pin 46a is arranged at one end, and a support pin 46b at the other end. Is provided. The support pin 46a side is rotatably connected to the protrusion of the mirror frame 41, and the support pin 46b is rotatably supported on the camera body side.

  As shown in FIG. 9, the reflection unit / light-shielding curtain unit drive mechanism section is disposed along the X direction obliquely up and down with the lens optical axis in between, and a pair of guide shafts that slidably support the mirror frame 41 44a and 44b, and a reflection unit drive motor 49 for slidingly driving the reflection unit 40 via a wire or the like.

  The reflection unit 40 is driven by the reflection unit drive motor 49 via the reflection unit / light-shielding curtain unit drive mechanism, and the main mirror 42 is the first position on the + X side lens optical axis. ) And a retracted position (P), which is the second position retracted from the lens optical axis on the −X side, while maintaining a state inclined by a predetermined angle with respect to the lens optical axis. In a state where the main mirror 42 is at the viewfinder observation position (N), the subject light beam is reflected upward by the main mirror 42 and reaches the screen 5. A part of the subject light flux passes through the half mirror part of the main mirror 42, is reflected by the sub mirror 43, and enters the AF sensor part 8. When the main mirror 42 is in the retracted position (P), the subject light flux passes through the open shutter unit 3 and reaches the light receiving surface 4 a of the image sensor 4.

  The light-shielding curtain unit 45 is driven by the mirror frame 41 of the reflection unit 40 via the support pin 46a. When the main mirror 42 is at the finder observation position (N), the light shielding sheets 45a, 45b, 45c,... Are folded and stored in the retreat position (Q) retracted from below the screen 5 (FIG. 9). In this state, the subject luminous flux is reflected by the main mirror 42 and reaches the screen 5 without being blocked by the light shielding curtain unit 45.

  Further, each light shielding plate of the light shielding curtain unit 45 is pulled out in the −X direction from the folded state via the support pin 46 a when the main mirror 42 moves to the retracted position (P), and the light shielding position (R ) (FIG. 9). In this state, unnecessary light that reaches the screen 5 from the eyepiece lens 7 of the finder optical system through the pentaprism 6 is cut by the light shielding curtain unit 45, and entry into the photographing optical path is prevented.

  In single-shooting with the single-lens reflex camera of the present embodiment having the above-described configuration, each operation is controlled under the control of the control unit 9 as in the single-lens reflex camera 10 of the first embodiment. When the power is turned on, the reflection motor 40 is driven by the drive motor 49 to move the main mirror 42 to the finder observation position (N) on the lens optical axis. Further, the light shielding curtain unit 45 is folded to the retracted position (Q). In this state, the subject luminous flux incident through the photographing lens 1 is reflected by the main mirror 42, reaches the screen 5 without being shielded by the light shielding curtain unit 45, and observes the subject image by the optical finder via the pentaprism 6 and the eyepiece 7. Is possible.

  A part of the subject light beam that has passed through the main mirror 42 with the main mirror 42 in the viewfinder observation position (N) by the first stage operation of a release switch (not shown) is reflected by the sub-mirror 43, and the AF sensor unit 8 and a ranging signal is detected. The taking lens 1 is focused based on the distance measurement signal.

  Subsequently, the drive motor 49 is driven by the second stage operation of the release switch, and the reflection unit 40 is slid in the −X direction to move the main mirror 42 to the retracted position (P). The light shielding curtain unit 45 is pulled out in conjunction with the movement of the main mirror 42 and moves to a light shielding position (R) below the screen 5. The subject luminous flux passes through the shutter unit 3 in the open state and forms an image on the light receiving surface 4a of the image pickup device 4, and the exposure of the image pickup device 4 is started. At this time, the unnecessary light beam entering from the finder optical is prevented from entering the photographing optical path by the light shielding curtain unit 45.

  An image signal from the image sensor 4 is recorded on a medium or the like after image processing. After the exposure is completed, the reflection unit 40 is slid in the + X direction, the main mirror 42 is returned to the finder observation position (N) again, and the light-shielding curtain unit 45 is returned to the retracted position (Q).

  In the continuous shooting by the single-lens reflex camera of this embodiment, each operation is similarly controlled under the control of the control unit 9. First, when the first-stage operation of the release switch is performed, ranging by the AF sensor unit 8 is performed in a state where the main mirror 42 is at the viewfinder observation position (N) as in the case of the single shooting described above, and the photographing lens 1 Focusing is performed.

  Subsequently, the reflection unit drive motor 49 is rotated forward and backward by the second stage operation of the release switch, and the main mirror 42 is moved from the viewfinder observation position (N) to the retracted position (N) according to the continuous shooting speed (frame / second). The slide movement during P) is repeated. During continuous shooting, every time the main mirror 42 reaches the finder observation position (N), a ranging signal from the AF sensor unit 8 is detected. Observation with a finder is also possible in a flickering state. Each time the main mirror 42 moves to the retracted position (P), the subject light flux reaches the light receiving surface 4a of the image sensor 4 and exposure for continuous shooting by the image sensor 4 is executed. At this time, the light-shielding unit 40 is in the light-shielding position (V), and unnecessary light that has entered from the finder optical system is shielded by the light-shielding unit 40 to prevent entry into the photographing optical path.

  An image signal from the image sensor 4 is subjected to image processing, and is sequentially recorded on a medium or the like as an image signal. At that time, live view display is also possible. When the release switch is released, the reflection unit 40 is stopped in a state where the main mirror 42 is returned to the viewfinder observation position (N), and the continuous shooting is ended.

  According to the single-lens reflex camera of the present embodiment described above, the same effects as those of the first embodiment described above are obtained, and in the image sensor exposure state in which the main mirror 42 of the reflection unit 40 is in the retracted position, the light shielding curtain unit 45. Is spread below the screen 5, and unnecessary light entering from the viewfinder side to the imaging optical path side is shielded, so that a good imaging signal not affected by the unnecessary light can be obtained. Further, in the finder observation state, the light shielding curtain unit 45 is stored in a folded state, so that the light shielding curtain unit 45 can be easily arranged.

Next, a single-lens reflex camera according to a fourth embodiment of the present invention will be described with reference to FIG.
FIG. 10 is a front view showing the main configuration of the reflection unit and the light-shielding curtain unit in the single-lens reflex camera of this embodiment, and shows the viewfinder observation / AF distance measurement state and the image sensor exposure state.

  The single-lens reflex camera of this embodiment differs from the single-lens reflex camera 10 of the first embodiment only in the configuration of the reflection unit and the light-shielding curtain unit, and the other configurations are the same. The same components are denoted by the same reference numerals, and only different configurations will be described below.

  The single-lens reflex camera of this embodiment has a pair of a reflection unit 50 and a light-shielding curtain unit 55 that are slid by a reflection unit / light-shielding curtain unit drive mechanism.

  As shown in FIG. 10, the reflection unit 50 includes a mirror frame 51, a main mirror 52 that is held by the mirror frame and reflects the subject light beam in the finder optical axis direction, and a back surface of the half mirror portion at the center of the main mirror. The mirror frame 51 is fixed to the guide shafts 54a and 54b by a reflection unit / light-shielding curtain unit drive mechanism unit, which will be described later, which is fixedly supported on the side and reflects a part of the subject light beam to the AF sensor unit 8 side. It is supported so that it can slide along the X direction.

  The light-shielding curtain unit 55 is formed by a light-shielding sheet portion 56 and a wire portion 57 that can be wound and housed. A winding pulley 58b is connected to one end portion via a wire portion 57, and a spring 60 is suspended from a support pin 58a on the other end portion. The support pin 58a is connected to the protrusion of the mirror frame 51.

  As shown in FIG. 10, the reflection unit / light-shielding curtain unit drive mechanism section is disposed along the X direction obliquely up and down with the lens optical axis in between, and a pair of guide shafts that slidably support the mirror frame 51. 54a and 54b, and a drive motor 59 that rotationally drives the take-up pulley 58b to slide-drive the light-shielding curtain unit 55 and the reflection unit 50.

  The reflection unit 50 is driven by the drive motor 59 via the support pin 58a in a state of interlocking with the shielding curtain unit 55, and the main mirror 52 is the first position on the + X side lens optical axis (S finder observation position (S ) And the retracted position (T), which is the second position retracted from the lens optical axis on the −X side, while maintaining a state inclined at a predetermined angle with respect to the lens optical axis. When the main mirror 52 is at the viewfinder observation position (S), the subject light flux is reflected upward by the main mirror 52 and reaches the screen 5. Further, a part of the subject luminous flux passes through the half mirror part of the main mirror 52, is reflected by the sub mirror 53, and enters the AF sensor part 8. When the main mirror 52 is in the retracted position (T), the subject light flux passes through the open shutter unit 3 and reaches the light receiving surface 4 a of the image sensor 4.

  The light-shielding curtain unit 55 is slid by driving the take-up pulley 58b by the drive motor 59. When the main mirror 52 is at the viewfinder observation position (S), the light-shielding curtain unit 55 is taken up by the take-up pulley 58b. When in the retracted position (U) and the main mirror 52 is in the retracted position (T), it slides to the light shielding position (V) below the screen 5. When the light shielding curtain unit 55 is in the retracted position (U), the subject light beam is reflected by the main mirror 52 and reaches the screen 5 without being blocked by the light shielding curtain unit 55. In a state in which the light shielding curtain unit 55 is in the light shielding position (V), unnecessary light reaching the screen 5 from the eyepiece lens 7 of the finder optical system through the pentaprism 6 is cut by the light shielding curtain unit 55 and enters the photographing optical path. Ingress is prevented.

  In single-shooting with the single-lens reflex camera of the present embodiment having the above-described configuration, each operation is controlled under the control of the control unit 9 as in the single-lens reflex camera 10 of the first embodiment. As in the case of the third embodiment, when the power is turned on, the reflection unit 50 is in the finder observation position (S), and the object image can be observed by the optical finder. A ranging signal is detected by the AF sensor unit 8 in the first stage operation of a release switch (not shown). The taking lens 1 is focused based on the distance measurement signal. Further, the drive motor 59 is driven by the second-stage operation of the release switch, the light shielding curtain unit 55 is pulled out from the take-up pulley 58b, and moves to the light shielding position (V) below the screen 5. The reflection unit 50 is also driven in conjunction with the main mirror 52 to slide to the retracted position (T). The subject luminous flux passes through the shutter unit 3 in the open state and forms an image on the light receiving surface 4a of the image pickup device 4, and the exposure of the image pickup device 4 is started. In this state, unnecessary light that has entered from the finder optical system is shielded by the light shielding unit unit 55, thereby preventing entry into the photographing optical path.

  An image signal from the image sensor 4 is recorded on a medium or the like after image processing. After the exposure is completed, the reflection unit 50 is slid in the + X direction, the main mirror 52 is returned to the finder observation position (S) again, and the light-shielding curtain unit 55 is returned to the retracted position (U).

  In the continuous shooting by the single-lens reflex camera of this embodiment, each operation is similarly controlled under the control of the control unit 9. The operation is the same as in the third embodiment. When the first-stage operation of the release switch is performed, the AF sensor unit 8 performs distance measurement with the main mirror 52 in the finder observation position (S). Is executed, and the photographing lens 1 is focused. The drive motor 59 is driven forward and backward by the second stage operation of the release switch, and the main mirror 52 together with the light-shielding curtain unit 55 is moved from the viewfinder observation position (S) to the retracted position (in accordance with the continuous shooting speed (frame / second)) T), and the sliding movement from the retracted position (U) to the light shielding position (V) is repeated, and continuous shooting is executed.

  According to the single-lens reflex camera of the present embodiment described above, the same effects as those of the first embodiment described above are obtained, and the light-shielding curtain unit 55 is obtained in the image sensor exposure state in which the main mirror 52 of the reflection unit 50 is in the retracted position. Since the unnecessary light from the viewfinder side to the imaging optical path side is shielded, a good imaging signal that is not affected by the unnecessary light can be obtained. Further, in the viewfinder observation state, the light shielding curtain unit 55 is easily wound up and accommodated by the take-up pulley 58b.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  A single-lens reflex camera according to the present invention has a simple configuration, has a quick response to switching between an exposure state and a non-exposure state of an image sensor, and can also block light incident from a finder optical system. Can be used as a reflex camera.

FIG. 4 is a layout view showing the main configuration of the single-lens reflex camera according to the first embodiment of the present invention as viewed from the side of the optical axis, showing a finder observation / AF distance measurement state. FIG. 2 is an arrangement view showing the main configuration of the single-lens reflex camera of FIG. 1 as viewed from the side of the optical axis, showing an image sensor exposure state. FIG. 3 is a front view of a reflection unit and a light shielding curtain unit applied to the single-lens reflex camera of FIG. 1 in a finder observation / AF distance measurement state. It is a front view in the image pick-up element exposure state of the reflection unit and light-shielding curtain unit applied to the single-lens reflex camera of FIG. It is a perspective view in the image pick-up element exposure state of the reflection unit of the single-lens reflex camera of FIG. It is a front view which shows the main structures of the reflective unit and the light-shielding curtain unit in the single-lens reflex camera of 2nd embodiment of this invention, Comprising: A finder observation / AF range-finding state is shown. FIG. 7 is a front view illustrating main components of a reflection unit and a light shielding curtain unit in the single-lens reflex camera of FIG. 6, and shows an image sensor exposure state. FIG. 7 is a front view showing the main configuration of a reflection unit and a light shielding curtain unit in the single-lens reflex camera of FIG. It is a front view which shows the main structures of the reflection unit and the light-shielding curtain unit in the single-lens reflex camera of 3rd embodiment of this invention, Comprising: A finder observation / AF ranging state and an image pick-up element exposure state are shown. It is a front view which shows the main structures of the reflection unit and the light-shielding curtain unit in the single-lens reflex camera of 4th embodiment of this invention, Comprising: A finder observation / AF ranging state and an image pick-up element exposure state are shown. It is the layout seen from the optical axis side surface which shows the main structures of the conventional single-lens reflex camera.

Explanation of symbols

1 ... Shooting lens (shooting optical system)
2, 30, 40, 50 ... Reflection unit 4 ... Image sensor 5 ... Screen (finder optical system)
6 ... Penta prism (finder optical system)
7 ... Eyepiece (finder optical system)
12, 32, 42, 52
... Main mirror (reflection unit)
17, 45, 55 ... light-shielding curtain unit 37 ... light-shielding curtain unit (first movable light-shielding curtain)
38 ... Light-shielding curtain unit (second movable light-shielding curtain)
A, E, N, S
... Finder observation position (first position)
B, F, G, P, T
... Image sensor exposure position (second position)
D, I, L, R, V ... Shading position

Claims (4)

An image sensor;
A photographing optical system for generating a subject image related to a subject light beam incident on the light receiving surface of the image sensor;
A viewfinder optical system for forming the subject image on the viewfinder;
A first position at which the subject light beam that has passed through the photographing optical system is reflected by a reflecting surface and guided to the finder optical system, and retracted from the optical axis of the finder optical system so that the subject light beam can be incident on the light receiving surface. A reflection unit that slides in a direction across the optical axis of the finder optical system while maintaining the angle of the reflection surface between the second position and the second position.
In conjunction with the slide of the reflection unit, a light shielding curtain unit that blocks incident light from the finder optical system,
A single-lens reflex camera.   The light-shielding curtain unit is provided with a first movable light-shielding curtain and a second movable light-shielding curtain on both sides in the sliding direction across the reflection unit. 2. The single-lens reflex camera according to claim 1, wherein either one of the second movable light-shielding curtains is disposed at a light-shielding position.   The single-lens reflex camera according to claim 1, wherein the light-shielding curtain unit is folded when the reflection unit is at the first position, and is unfolded as it moves to the second position. 2. The single-lens reflex camera according to claim 1, wherein the light-shielding curtain unit is rolled up when the reflection unit is in the first position, and is unfolded as the reflection unit moves to the second position.

Images