JP2007011070A - Digital single-lens reflex camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital single-lens reflex camera capable of both a high speed phase difference AF operation with a short release time lag and through-image-display. <P>SOLUTION: A subject image passed through a photographic lens is imaged by an imager 35. The subject image can be observed via a screen 12 disposed in an optically conjugating position relative to the imager 35, a prism 13, a mirror (A)15, a relay system lens 16, a mirror (B)17, a mirror (C)18, and an eyepiece system lens 20. The mirror (C)18 is composed of a half mirror, and the subject image transmitted through the mirror (C)18 is imaged by a sub-imager 23. Then, based on an output from the imager 35 or sub-imager 23, the subject image is displayed on a monitor 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a digital single-lens reflex camera, and more particularly to an improvement of a digital camera capable of displaying an image being observed and an image being shot on a display screen.

  Conventionally, a phase difference detection method is known as automatic focus adjustment (AF) of a digital single-lens reflex camera (see, for example, Patent Document 1). In this method, since the defocus direction and the defocus amount can be grasped by one focus detection operation, it is possible to realize high-speed AF with a short release time lag.

In addition, phase difference AF and contrast AF can be selected according to the situation. When contrast AF is selected, the mirror is raised (retracted from the photographing optical path) to perform a so-called live view (through image display). There has also been proposed a digital still camera capable of the above (see, for example, Patent Document 2).
JP 2004-184952 A JP 2001-272593 A

  By the way, in the phase difference detection AF described in Patent Document 1 described above, the light beam that has passed through the photographic lens passes through the main mirror having a half mirror at the center, and further behind it. The light is reflected downward by the sub-mirror disposed in the lens and guided to the AF optical system and the AF sensor. Since the image sensor that captures the subject image is arranged behind the main mirror, the subject image is not guided to the image sensor during the phase difference AF operation, and a through image (almost real-time moving image). Cannot be displayed on a monitor or the like.

  In other words, in order to display a through image on a monitor or the like, it is necessary to raise the main mirror and guide the subject image directly to the image sensor, but in order to realize phase difference AF, the main mirror is lowered (in the imaging optical path). It is difficult to perform phase difference AF while displaying a through image.

  On the other hand, in the camera described in Patent Document 2, when the phase difference AF is selected, it is necessary to lower the main mirror, so that live view display cannot be performed. In addition, in order to perform live view display, contrast AF must be selected, and thus high-speed AF cannot be realized.

  Accordingly, the present invention has been made in view of the above circumstances, and an object thereof is to provide a digital single-lens reflex camera capable of achieving both a high-speed phase difference AF operation with a short release time lag and a through image display.

  That is, according to the first aspect of the present invention, a photographing lens, a first imaging element that captures an image that has passed through the photographing lens, and a screen that is disposed at a position optically conjugate with the first imaging element. And a relay optical system that re-images the subject image formed on the screen, a half mirror that reflects and transmits the subject image that has passed through the relay optical system, and a subject image reflected by the half mirror can be observed A magnifying optical system, a second image sensor that captures a subject image that has passed through the half mirror, and a display unit that displays the subject image based on the output of the first image sensor or the second image sensor. It is characterized by comprising.

  The invention described in claim 2 further comprises control means for controlling driving of the first image sensor and the second image sensor in the invention described in claim 1, wherein the control means comprises: When the photographing operation is performed, the first image sensor is driven and controlled, and when the subject image is continuously displayed on the display means, the second image sensor is driven and controlled. To do.

  According to a third aspect of the present invention, in the first aspect of the present invention, a re-imaging optical system is disposed between the second image sensor and the half mirror.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the image obtained by the output of the first image sensor and the image obtained by the output of the second image sensor are luminance. The distribution is substantially equal.

  According to a fifth aspect of the present invention, there is provided a photographic lens, a first image sensor that captures a subject image that has passed through the photographic lens, and a screen that is disposed at a position optically conjugate with the first image sensor. A finder optical system for observing a subject image formed on the screen, a second image sensor provided on the optical path side of the finder optical system, and the first image sensor or the second image sensor. Display means for displaying a subject image on the basis of the output of the first image sensor, and a half mirror provided in the vicinity of the second image sensor for dividing the optical path of the subject image.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the first to fifth reflecting members are disposed in the viewfinder optical system, and are provided in order from the photographing lens side. In addition, the half mirror is constituted by the fourth reflecting member.

  According to a seventh aspect of the present invention, there is provided a photographing lens, a first imaging element that captures an image that has passed through the photographing lens, and a screen disposed at a position optically conjugate with the first imaging element. A relay optical system that re-forms the subject image formed on the screen, a dimming mirror that performs at least one of reflecting or transmitting the subject image that has passed through the relay optical system, and the adjusting mirror. A loupe optical system that makes it possible to observe the subject image reflected by the light mirror, a second image sensor that picks up the subject image that has passed through the light control mirror, and a ratio between the reflectance and the transmittance of the light control mirror. And a control means for changing.

  The invention according to claim 8 is the invention according to claim 7, wherein the control means increases the transmittance of the dimming mirror only when a predetermined mode is selected. To do.

  The invention according to claim 9 is the invention according to claim 8, wherein the predetermined mode is a mode in which the second image sensor continuously captures the subject image. .

  According to a tenth aspect of the present invention, there is provided the display device according to the seventh aspect, further comprising display means for displaying a subject image based on the output of the first image sensor or the second image sensor. Features.

  According to an eleventh aspect of the present invention, there is provided a photographing lens, a first imaging element that captures an image that has passed through the photographing lens, and a screen disposed at a position optically conjugate with the first imaging element. A relay optical system that re-forms the subject image formed on the screen, a reflective member that can transmit at least a part of the subject image that has passed through the relay optical system, and a reflection member that is not transmitted by the reflection member. A loupe optical system that makes it possible to observe the subject image, a second imaging device that captures the subject image that has passed through the reflecting member, and a subject based on the output of the first imaging device or the second imaging device. Display means for displaying an image.

  The invention described in claim 12 further comprises control means for controlling driving of the first image sensor and the second image sensor in the invention described in claim 11, wherein the control means comprises: When the photographing operation is performed, the first image sensor is driven and controlled, and when the subject image is continuously displayed on the display means, the second image sensor is driven and controlled. To do.

  According to a thirteenth aspect of the invention, in the eleventh aspect of the invention, a re-imaging optical system is disposed between the second image sensor and the reflecting member.

  According to a fourteenth aspect of the present invention, in the invention according to the eleventh aspect, an image obtained by the output of the first image sensor and an image obtained by the output of the second image sensor are luminance. The distribution is substantially equal.

  The invention described in claim 15 is the invention described in claim 11, wherein the reflecting member is a half mirror.

  According to a sixteenth aspect of the present invention, in the invention according to the eleventh aspect, the reflecting member is constituted by a dimming mirror capable of changing a reflectance.

  According to the present invention, it is possible to provide a digital single-lens reflex camera that can achieve both a high-speed phase difference AF operation with a short release time lag and a through image display.

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

(First embodiment)
FIG. 1 shows a first embodiment of the present invention and is a cross-sectional view showing a configuration of a main body of a digital single-lens reflex camera of the present invention.

  In FIG. 1, this digital single-lens reflex camera (hereinafter abbreviated as “camera”) mainly includes an interchangeable lens (not shown) and a camera body 10 as a camera body, and a front portion of the camera body 10. A desired interchangeable lens is detachably attached to the body mount 45 provided on the body.

  Part of the subject luminous flux incident from an interchangeable lens (not shown) is reflected by the surface of the main mirror 11 formed of a half mirror, and further enters the prism 13 via the screen 12. The subject luminous flux incident on the prism 13 is reflected by a reflecting surface in the prism 13 and a mirror A (hereinafter referred to as mirror (A)) 15, and further via a relay lens 16 composed of a plurality of lenses. Reflected by a mirror B (hereinafter referred to as a mirror (B)) 17 and a mirror C (hereinafter referred to as a mirror (C)) 18, and passed through an eyepiece lens (loupe optical system) 20 composed of a plurality of lenses. It is observed with the eyes of a photographer not shown. The prism 13, mirror (A) 15, relay lens 16, mirror (B) 17, and mirror (C) 18 constitute a relay optical system. These relay optical systems re-image the subject image formed on the screen 12 between the mirror (C) 18 and the eyepiece lens 20.

  The mirror (B) 17 is composed of a half mirror, and a part of the incident light is transmitted through the mirror (B) 17, and a recombination optical system disposed behind the mirror (B) 17. The light is guided to the sub imager 23 through the re-imaging lens 22. This sub-imager 23 constitutes a second image sensor with respect to an imager 35 which is a first image sensor to be described later, and displays a substantially real-time moving image on the monitor 40 as a through image. It is. Further, in the vicinity of the mirror (C) 18, an in-finder display LCD 26 for displaying shooting information and the like in the viewfinder 28, and shooting information and the like displayed on the in-finder display LCD 26 are displayed on the eyepiece lens 20. A display prism 25 is arranged to guide the photographer's eyes through

  The subject luminous flux that has passed through the main mirror 11 is reflected by the sub-mirror 30 attached to the back side of the main mirror 11 and guided to the AF unit 31 for automatic ranging. The main mirror 11 is provided so as to be rotatable about a shaft 11a. When observing a subject, it is arranged at the position shown in the figure, and at the time of shooting, although not shown in the figure, it moves upward about the rotation axis 11a to become a position retracted from the imaging optical path (retracted position). The sub mirror 30 is folded when the main mirror 11 is moved to the retracted position, and is moved together with the main mirror 11 to the retracted position.

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

  FIG. 2 is a block diagram showing the configuration of the electrical system of the digital single-lens reflex camera in the present embodiment. The block diagram of this camera shows a state where an interchangeable lens is attached.

  In FIG. 2, a calculation unit 50 is a control means for controlling the entire camera and performing calculation, and is constituted by a CPU, for example. A shutter mirror drive motor 52 is connected to the arithmetic unit 50 via a motor drive circuit 51 and a focal plane shutter 33 is connected via a shutter control circuit 53. The calculation unit 50 includes a distance measuring sensor 55 provided in the AF unit 31, a photometric sensor 56 for measuring the brightness of the subject, and a charge cam switch (SW) that is switched when a shutter charge is performed. 57, attached to the front curtain (not shown) of the focal plane shutter 33, a front curtain switch (SW) 58 for detecting the fully open state of the shutter opening, and an imager for driving the imager 35. A driving circuit 60, a sub-imager driving circuit 61 for driving the sub-imager 23, a monitor driving circuit 62 for driving the monitor 40, and an LCD driving circuit 63 for driving the in-finder display LCD 26 are connected. Has been.

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

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

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

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

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

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

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

  This camera can normally observe a subject image not through the through image mode but through the viewfinder. Here, the photographing operation in the through image mode, which is a feature of the present invention, will be described.

  FIG. 3 is a flowchart for explaining the operation of the camera in the through image mode in the first embodiment.

  When the live view mode routine is entered, first, in step S1, the state of the first (1st) release switch, which is the half-pressed state of the two-stage release switch 67 described above, is determined. Here, the process waits until the first release switch is turned on. If the first release switch is turned on, it is determined in subsequent step S2 whether or not the in-focus state has been achieved. Here, when it is not in focus, it transfers to step S3 and the state of a 1st release switch is determined again. If the first release switch is turned on in step S3, the process shifts to step S4 to calculate the amount of defocus, and in step S5, based on the defocus amount calculated in step S4. Thus, the focus motor 83 is driven via the motor drive circuit 82 to adjust the photographing lens. Thereafter, the process proceeds to step S2. On the other hand, if the first release switch is turned off in step S3, the process proceeds to step S1.

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

  If the second release switch is turned on in step S7, the process proceeds to step S9 and the monitor 40 is turned off. Subsequently, in step S10, the driving of the sub imager 23 is stopped. In step S11, the shutter mirror drive motor 52 is driven via the motor drive circuit 51. Next, in step S12, the lens is narrowed down to a predetermined value. Thereafter, in step S13, it is determined whether or not the main mirror 11 is up, that is, whether or not the main mirror 11 has moved from the photographing optical path to a retracted position (not shown), and waits until the movement is completed. If the main mirror 11 has been raised, the shutter mirror drive motor 52 is stopped in step S14.

  Here, in step S15, exposure by the imager 35, that is, imaging is performed. Subsequently, in step S16, the subject image captured by this imaging is read out. When the aperture motor 85 is driven in step S17, the lens aperture is opened in the subsequent step S18. Next, in step S19, the process waits until the main mirror 11 is lowered by the shutter mirror drive motor 52 (return from the retracted position to the photographing optical path) and the shutter charge by the charge cam switch 57 is completed. When the down of the main mirror 11 and the shutter charge are completed, the shutter mirror drive motor 52 is stopped in step S20.

  Next, in step S21, the sub-imager 23 is driven to display a through image. In step S22, the monitor 40 is turned on. Accordingly, the subject image as a through image captured by the sub imager 23 can be confirmed through the monitor 40. Thereafter, the process proceeds to step S1.

  Thus, according to the first embodiment, it is possible to achieve both high-speed phase difference AF operation with a short release time lag and through image display.

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

  In the first embodiment described above, the subject image is re-imaged on the sub-imager using the half mirror as the mirror (B) in the relay optical system. However, the present invention is not limited to this. In the second embodiment described below, an example in which the mirror (B) in the relay optical system is configured by a dimming mirror will be described.

  FIG. 4 shows a second embodiment of the present invention and is a cross-sectional view showing the configuration of the main body of the digital single-lens reflex camera of the present invention.

  In FIG. 4, the camera 10 'is mainly composed of an interchangeable lens (not shown) and a camera body 10' as a camera body, and a body mount 45 provided on the front surface of the camera body 10 '. In addition, a desired interchangeable lens is detachably attached. The relay optical system in the camera body 10 ′ includes a prism 13, a mirror (A) 15, a relay system lens 16, a mirror B (light control mirror) 19, and a mirror (C) 18.

  As will be described later, the light control mirror 19 is configured so that its transmittance (reflectance) can be changed by an electric circuit. Therefore, the subject luminous flux that has passed through the relay system lens 16 is transmitted when the transmittance of the light control mirror 19 is high, and is guided to the sub imager 23 through the re-imaging system lens 22. On the other hand, when the reflectance is high, the light is reflected as it is on the surface of the light control mirror 19 and guided from the mirror (C) 18 to the eyepiece lens 20.

  In the second embodiment, the configuration of the camera body 10 'is the same as that of the above-described first embodiment except that the mirror (B) 17 of the relay optical system is replaced by the dimming mirror 19. The configuration of the body 10 is the same. Therefore, in order to avoid duplication of description, in the following description, the same parts are denoted by the same reference numerals, illustration and description thereof are omitted, and only different parts will be described.

  FIG. 5 is a block diagram showing the configuration of the electrical system of the digital single-lens reflex camera in the second embodiment. The block diagram of this camera shows a state where an interchangeable lens is attached.

  5 is different from the block diagram of FIG. 2 in that a dimming mirror driving circuit 73 for changing the transmittance of the dimming mirror 19 is connected to the arithmetic unit 50 in the camera body 10 ′. It is a point. The dimming mirror drive circuit 73 changes the transmittance of the dimming mirror 19 by applying a voltage. For example, if the applied voltage is high, the transmittance is high, and more subject light flux is guided to the sub imager 23. On the other hand, if the applied voltage is low, the dimming mirror 19 has a high reflectance so that almost all the light flux is reflected.

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

  This camera can normally observe a subject image not through the through image mode but through the viewfinder. Here, the photographing operation in the through image mode, which is a feature of the present invention, will be described.

  FIG. 6 is a flowchart for explaining the operation of the camera in the through image mode in the second embodiment.

  When the live view mode routine is entered, first, in step S31, it is confirmed whether or not the live view mode is set. Here, in the through image mode, the process proceeds to step S33, and the dimming mirror driving circuit 73 is driven to set the transmittance of the dimming mirror 19 high. That is, the subject luminous flux that has passed through the relay lens 16 passes through the light control mirror 19 and is imaged on the sub-imager 23 via the re-imaging lens 22. On the other hand, if the through image mode is not set in step S31, the drive of the light control mirror 19 is stopped. Thereafter, the routine is exited.

  In step S34, the state of the first release switch described above is determined. Here, the process waits until the first release switch is turned on. If the first release switch is turned on, it is determined in subsequent step S35 whether or not the in-focus state has been achieved. If it is not in focus, the process proceeds to step S36, and the state of the first release switch is determined again. If the first release switch is turned on in step S36, the process shifts to step S37 to calculate the amount of focus deviation, and in step S38, based on the amount of focus deviation calculated in step S4. The focus motor 83 is driven via the motor drive circuit 82 to adjust the photographing lens. Thereafter, the process proceeds to step S35. On the other hand, if the first release switch is turned off in step S36, the process proceeds to step S34.

  If the in-focus state is obtained in step S35, the process proceeds to step S39 to perform photometry and its calculation. Here, the aperture value and the shutter speed are determined. Next, in step S40, the state of the second release switch described above is determined. If the second release switch is not turned on, the process proceeds to step S41, and the state of the first release switch is determined. If the first release switch is turned on in step S41, the process proceeds to step S35. If not, the process proceeds to step S34, and the subsequent processing operations are repeated.

  If the second release switch is turned on in step S40, the process proceeds to step S42 and the monitor 40 is turned off. Subsequently, in step S43, the driving of the sub imager 23 is stopped. Further, in step S44, the driving of the dimming mirror drive circuit 73 is stopped, and the transmittance of the dimming mirror 19 is lowered. That is, the light control mirror 19 functions almost as a reflection mirror. In step S45, the shutter mirror drive motor 52 is driven via the motor drive circuit 51. Next, in step S46, the lens is narrowed down to a predetermined value. Thereafter, in step S47, it is determined whether or not the main mirror 11 is up, that is, whether or not the main mirror 11 has moved from the photographing optical path to a retracted position (not shown), and waits until the movement is completed. If the main mirror 11 has been raised, the shutter mirror drive motor 52 is stopped in step S48.

  Here, in step S49, exposure by the imager 35, that is, imaging is performed. Subsequently, in step S50, the subject image captured by this imaging is read out. When the aperture motor 85 is driven in step S51, the lens aperture is opened in the subsequent step S52. Next, in step S53, the process waits until the main mirror 11 is lowered by the shutter mirror drive motor 52 (return from the retracted position to the photographing optical path) and the shutter charge by the charge cam switch 57 is completed. When the down of the main mirror 11 and the shutter charge are completed, the shutter mirror drive motor 52 is stopped in step S54.

  Next, in step S55, the dimming mirror drive circuit 73 is driven again to increase the transmittance of the dimming mirror 19. Subsequently, in step S56, the sub imager 23 is driven so that the subject image transmitted through the light control mirror 19 can be displayed as a through image. In step S57, the monitor 40 is turned on. Accordingly, the subject image as a through image captured by the sub imager 23 can be confirmed through the monitor 40. Thereafter, the process proceeds to step S1.

  Thus, according to the second embodiment, since the dimming mirror is used instead of the half mirror located behind the relay lens 16, the sub-imager 23 is compared to the first embodiment described above. The amount of light of the subject light flux guided to the light increases, and a bright through image is obtained.

  FIG. 7 is a diagram illustrating an example of the reflectance and transmittance of each reflecting member including the relay optical system and the main mirror 11 in the second embodiment. In FIG. 7, the first reflecting surface of the prism 13 shown in FIG. 4 is shown as a mirror 13a, and the second reflecting surface is shown as a mirror 13b. The reflectance and transmittance of each of these reflecting members are shown in Table 1 below.

  Referring to Table 1 above, the mirror 11 is a main mirror partly composed of a half mirror, and has a reflectance of 0.7 and a transmittance of 0.3 during normal photographing. The mirrors 13a and 13b, the mirror (A) 15, and the mirror (C) 18 have a reflectance of 0.95 and a transmittance of 0. The light control mirror 19 has a reflectance of 0.85 and a transmittance of 0 when the drive is stopped when no voltage is applied. The reason why the reflectivity of the mirrors 13a, 13b, 15, 18, and 19 does not become 1 is that there is a loss. The reason why the loss of the mirror 19 is larger than that of the other reflection mirrors is that the loss is large because of the dimming mirror.

  The light A reaching the viewfinder eyepiece system via the eyepiece 20 is obtained by multiplying the reflectances of the mirrors 11, 13a, 13b, 15, 18, and 19, but in this case, the light incident on the mirror 11 is If it is 1, it becomes 0.48. This is a value about 1 EV lower than the subject light quantity. The light quantity B of the sub imager 23 is zero.

  In contrast, in the through image display, that is, in the continuous shooting mode, the mirror 11 has a reflectance of 0.7 and a transmittance of 0.3, and the mirrors 13a and 13b, the mirror (A) 15, and the mirror (C) No. 18 has a reflectance of 0.95 and a transmittance of 0. The light control mirror 19 has a reflectance of 0.4 and a transmittance of 0.4 in a driving state where a voltage is applied. The light A reaching the viewfinder eyepiece system in this case is 0.23. This is a value about 2 EV lower than the subject light quantity. Further, the light amount B of the sub imager 23 is 0.24, which is similarly a value that is about 2 EV lower than the subject light amount.

  In the first embodiment described above, when the reflectance and transmittance of the half mirror 17 are 0.5, the light amount of the finder 28 is always a light amount that is reduced by about 2 EV with respect to the subject light amount. On the other hand, in the second embodiment, a dimming mirror 19 is used instead of the half mirror (B) 17, and the reflectance during normal photographing can be switched to about twice the reflectance during continuous photographing. Therefore, the light quantity of the finder 28 during normal shooting can be increased by about 1 EV compared to continuous shooting.

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

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating a configuration of a main body portion of a digital single-lens reflex camera of the present invention, showing a first embodiment of the present invention. It is a block diagram which shows the structure of the electric system of the digital single-lens reflex camera in the 1st Embodiment of this invention. 6 is a flowchart for explaining the operation of the camera in a through image mode in the first embodiment. FIG. 3 is a cross-sectional view illustrating a configuration of a main body of a digital single-lens reflex camera of the present invention, showing a second embodiment of the present invention. It is a block diagram which shows the structure of the electric system of the digital single-lens reflex camera in the 2nd Embodiment of this invention. 10 is a flowchart for explaining the operation of the camera in a through image mode in the second embodiment. It is a figure explaining the example of the reflectance and the transmittance | permeability of each reflecting member which consist of a relay optical system and the main mirror 11 in 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 10 '... Camera body, 11 ... Main mirror, 12 ... Screen, 13 ... Prism, 15 ... Mirror A (mirror (A)), 16 ... Relay system lens, 17 ... Mirror B (mirror (B)), 18 Mirror C (mirror (C)) 19 Mirror B (dimming mirror) 20 Eyepiece lens 22 Re-imaging lens 23 Sub-imager 25 Display prism 26 Viewfinder display LCD, 28 ... finder, 30 ... sub mirror, 31 ... AF unit, 33 ... focal plane shutter, 34 ... low pass filter, 35 ... imager, 36 ... imager plate, 38 ... substrate, 40 ... monitor, 41 ... monitor window, 45 ... Body mount 50... Arithmetic unit 51. Motor drive circuit 52. Shutter mirror drive motor 53. Shutter control circuit 55. Distance sensor 56 ... Photometric sensor 57 ... Charge cam switch (SW) 58 ... Leading curtain switch (SW) 60 ... Imager drive circuit 61 ... Sub-imager drive circuit 62 ... Monitor drive circuit 63 ... LCD drive circuit , 65 ... operation buttons, 66 ... operation dial, 67 ... release switch (SW), 69 ... recording medium, 70 ... memory, 71 ... image data memory, 73 ... dimming mirror drive circuit, 80 ... interchangeable lens, 81 ... calculation , 82: motor drive circuit, 83: focus motor, 84: aperture drive circuit, 85: aperture motor, 87: focus pulse counter, 88 ... zoom encoder, 90 ... memory.

Claims (16)

A taking lens,
A first image sensor that images the image that has passed through the photographic lens;
A screen disposed at a position optically conjugate with the first image sensor;
A relay optical system for re-imaging the subject image formed on the screen;
A half mirror that reflects and transmits a subject image that has passed through the relay optical system;
A loupe optical system that makes it possible to observe the subject image reflected by the half mirror;
A second image sensor that images a subject image transmitted through the half mirror;
Display means for displaying a subject image based on the output of the first image sensor or the second image sensor;
A digital single-lens reflex camera characterized by comprising: And further comprising control means for controlling driving of the first image sensor and the second image sensor,
The control means controls the drive of the first image sensor when a photographing operation is performed, and controls the drive of the second image sensor when the subject image is continuously displayed on the display means. The digital single-lens reflex camera according to claim 1.   The digital single-lens reflex camera according to claim 1, wherein a re-imaging optical system is disposed between the second image sensor and the half mirror.   2. The digital single-lens reflex camera according to claim 1, wherein an image obtained by the output of the first image sensor and an image obtained by the output of the second image sensor have substantially the same luminance distribution. camera. A taking lens,
A first image sensor that images a subject image that has passed through the photographing lens;
A screen disposed at a position optically conjugate with the first image sensor;
A viewfinder optical system for observing the subject image formed on the screen;
A second image sensor provided on the optical path side of the finder optical system;
Display means for displaying a subject image based on the output of the first image sensor or the second image sensor;
A half mirror provided in the vicinity of the second image sensor for dividing the optical path of the subject image;
A digital single-lens reflex camera characterized by comprising: It is arranged in the finder optical system, further comprising first to fifth reflecting members provided in order from the photographing lens side,
The digital single-lens reflex camera according to claim 5, wherein the half mirror is configured by the fourth reflecting member. A taking lens,
A first image sensor that images the image that has passed through the photographic lens;
A screen disposed at a position optically conjugate with the first image sensor;
A relay optical system for re-imaging the subject image formed on the screen;
A dimming mirror that performs at least one of reflecting or transmitting a subject image that has passed through the relay optical system;
A loupe optical system that makes it possible to observe the subject image reflected by the light control mirror;
A second image sensor that images a subject image transmitted through the light control mirror;
Control means for changing the ratio of the reflectance and transmittance of the dimming mirror;
A digital single-lens reflex camera characterized by comprising:   8. The digital single-lens reflex camera according to claim 7, wherein the control means increases the transmittance of the light control mirror only when a predetermined mode is selected.   The digital single-lens reflex camera according to claim 8, wherein the predetermined mode is a mode in which the second image sensor continuously captures the subject image.   8. The digital single-lens reflex camera according to claim 7, further comprising display means for displaying a subject image based on an output of the first image sensor or the second image sensor. A taking lens,
A first image sensor that images the image that has passed through the photographic lens;
A screen disposed at a position optically conjugate with the first image sensor;
A relay optical system for re-imaging the subject image formed on the screen;
A reflective member capable of transmitting at least part of the subject image that has passed through the relay optical system;
A loupe optical system that enables observation of an object image reflected without being transmitted by the reflecting member;
A second image sensor that images a subject image transmitted through the reflecting member;
Display means for displaying a subject image based on the output of the first image sensor or the second image sensor;
A digital single-lens reflex camera characterized by comprising: And further comprising control means for controlling driving of the first image sensor and the second image sensor,
The control means controls the drive of the first image sensor when a photographing operation is performed, and controls the drive of the second image sensor when the subject image is continuously displayed on the display means. The digital single-lens reflex camera according to claim 11.   The digital single-lens reflex camera according to claim 11, wherein a re-imaging optical system is disposed between the second image sensor and the reflecting member.   The digital single-lens reflex camera according to claim 11, wherein an image obtained by the output of the first image sensor and an image obtained by the output of the second image sensor have substantially the same luminance distribution. camera.   The digital single-lens reflex camera according to claim 11, wherein the reflecting member is a half mirror.   The digital single-lens reflex camera according to claim 11, wherein the reflection member is configured by a dimming mirror capable of changing reflectance.

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