JP2007006358A - Digital camera and digital single-lens reflex camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera and a digital single-lens reflex camera which do not give damage to an imager in deciding framing, even in the case of a single-lens reflex camera capable of through-image output. <P>SOLUTION: The subject light quantity to be incident via an exchange lens 80 having a photographic lens is adjusted by a diaphragm mechanism 102 via a diaphragm drive circuit 84 and an a diaphragm motor 85. Lens data including an open aperture value are acquired by an operations section 50 via an operation section 81 from the exchange lens 80. When a through-image mode is set, the initial value of the diaphragm mechanism 102 is set by an operation section 50 on the basis of the acquired lens data. During executing display of the through-image, setting of an aperture value of the aperture mechanism 102 is changed by the operation section 50 on the basis of subject luminance data detected by an photometric sensor 56. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

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

As a camera for displaying such a subject image, in addition to the exposure means for the main exposure, another imaging means is provided for monitoring the object field, and a half mirror is arranged in the finder optical system so that a through image (almost real time) is obtained. There is known a camera that guides a subject luminous flux to an image pickup device for display. In this case, in the through image display mode, images are repeatedly captured by the image sensor and displayed on the display device (see, for example, Patent Document 1).
JP 2000-165730 A

  On the other hand, in an interchangeable lens digital single-lens reflex camera (hereinafter simply referred to as a single-lens reflex camera), a bright lens of F number (FNo.) Or a telephoto lens is mounted on the sun in the screen. There was a risk of damaging the imager when framing. In particular, in a single-lens reflex camera capable of outputting a through image, the imager continues to be exposed even when framing is determined, so that there is a high risk of damage.

  Therefore, the present invention has been made in view of the above circumstances, and even a single-lens reflex camera capable of outputting a through image does not damage the imager when framing is determined, and the digital single-lens reflex camera. The purpose is to provide a camera.

  That is, according to the first aspect of the present invention, in a digital single-lens reflex camera having a through image mode for continuously capturing and displaying a subject image, a replaceable photographing lens and a subject incident through the photographing lens. An aperture mechanism for adjusting the amount of light, a data acquisition unit that acquires lens data including an open aperture value from the photographing lens, and the data acquired by the data acquisition unit when the through image mode is set A setting means for setting an initial value of the aperture mechanism based on the lens data; a photometry means for detecting the subject brightness; and the subject brightness data detected by the metering means during execution of the through image display. Changing means for changing the setting of the aperture value of the aperture mechanism.

  According to a second aspect of the present invention, in the first aspect of the invention, the changing unit changes the aperture value by a predetermined number of steps according to a change in the subject luminance.

  According to a third aspect of the present invention, in the first aspect of the present invention, the changing means is configured such that the aperture of the aperture mechanism is open, the subject brightness is higher than a predetermined value, and the photographing is performed. When the lens is a large-diameter lens, the diaphragm mechanism is narrowed down to a predetermined value.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the photometric means detects the subject luminance based on a luminance distribution of the through image.

  According to a fifth aspect of the present invention, in a digital single-lens reflex camera with interchangeable lenses, it is possible to select an image sensor for each frame, an image sensor capable of continuously capturing images at regular intervals, and a continuous image capturing mode. A selection unit; a storage unit that stores information unique to the lens; a light amount control unit built in the interchangeable lens; and a measurement unit that measures the luminance state of the subject. When the selected imaging mode is selected, the amount of light is reduced when the subject brightness exceeds a predetermined value.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the light amount control means is constituted by a diaphragm member in the lens.

  According to the seventh aspect of the present invention, in a digital single-lens reflex camera with interchangeable lenses, it is possible to select an image sensor for each frame, an image sensor capable of continuous image capture at a constant interval, and a continuous image capture mode. When a selection means, a storage means storing information unique to the lens, a light amount control means built in the interchangeable lens, a measurement means for measuring the luminance state of the subject, and a continuous imaging mode are selected Control means for setting the light quantity to a predetermined state by the light quantity control means based on the unique information of the mounted lens acquired by the information transmission means, the light quantity control means, While the continuous imaging mode is continued in the predetermined state, the amount of light is controlled when the luminance state of the subject exceeds a predetermined value.

  The invention according to claim 8 is the invention according to claim 7, wherein the measuring means is detection of a luminance distribution state of a captured image.

  According to a ninth aspect of the present invention, in a digital single-lens reflex camera having a through image mode for continuously capturing and displaying a subject image, an interchangeable photographic lens, imaging for each frame, and at regular intervals. An image sensor capable of continuous imaging, a selection unit that enables selection of a continuous imaging mode, a light amount adjusting unit that adjusts a subject light amount built in the interchangeable lens, and a photometric unit that detects a luminance state of the subject. Control means for controlling the light quantity adjustment means to reduce the amount of light when the subject brightness detected by the photometry means exceeds a predetermined value when a continuous imaging mode is selected by the selection means; It is characterized by comprising.

  According to a tenth aspect of the invention, in the ninth aspect of the invention, the light amount adjusting means is constituted by a diaphragm member in the photographing lens.

  According to the present invention, it is possible to provide a digital camera and a digital single-lens reflex camera that do not damage the imager when framing is determined even if the single-lens reflex camera is capable of outputting a through image.

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

  1 and 2 show an embodiment of the present invention, which is a cross-sectional view illustrating a configuration of a main body of a digital single-lens reflex camera according to the present invention, and FIG. 1 is a diagram illustrating a state during observation of a subject. FIG. 2 is a diagram showing a state at the time of photographing. FIG. 3 is a sectional view showing the configuration of the interchangeable lens of the digital single-lens reflex camera in the present embodiment.

  1 and 2, this digital single-lens reflex camera (hereinafter abbreviated as “camera”) is mainly composed of a camera body 10 as a camera body and an interchangeable lens 80 shown in FIG. A desired interchangeable lens 80 is detachably attached to a body mount 42 provided on the front surface of the camera body 10.

  In FIG. 1, a subject light beam incident from an interchangeable lens (not shown) is partially 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. A photographer (not shown) is 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 passes through an eyepiece lens 20 composed of a plurality of lenses. Observed by the eyes. 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 are for re-imaging the subject image formed on the screen 12 between the controller (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 re-imaging lens disposed behind the mirror (B) 17. 22 to the sub imager 23. The sub imager 23 constitutes a second image sensor with respect to an imager 35 which is a first image sensor to be described later. Further, in the vicinity of the mirror (C) 18, an in-finder display LCD 26 for displaying photographing information and the like in the finder, and the photographing information and the like displayed on the in-finder display LCD 26 are provided with the eyepiece system lens 20. A display prism 25 is disposed to guide the photographer's eyes through the display prism 25.

  The subject luminous flux that has passed through the main mirror 11 is reflected by a sub-mirror 30 attached to the back side of the main mirror 11 and guided to an AFAE unit 31 that is a measuring means for performing automatic distance measurement and photometry.

  The main mirror 11 is an optical path changing means provided so as to be rotatable about a shaft 11a. 1 is arranged at the position shown in FIG. 1 when observing the object, and moves upward about the axis 11a at the time of photographing, and as shown in FIG. 2, a position (evacuation position) retreated from the photographing optical path. Become. At this time, 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.

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

  On the other hand, the interchangeable lens 80 is configured as shown in FIG.

  The interchangeable lens 80 includes a photographing lens 101 including a focus lens 101a and a zoom lens 101b. A diaphragm 102 as a light amount adjusting unit or a light amount control unit is disposed between the focus lens 101a and the zoom lens 101b. Further, a lens mount 105 on the lens side that engages with the body mount 42 for mounting the interchangeable lens 80 on the camera body 10 is provided outside the interchangeable lens 80 and on the camera body 10 (not shown). ing. Due to the engagement between the body mount 42 and the lens mount 105, the interchangeable lens 80 is detachable from the camera body 10.

  FIG. 4 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. 4, a calculation unit 50 controls the entire camera and performs calculation, and has functions of data acquisition means, setting means, selection means, change means, and control means, such as a CPU. Consists of. 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.

  Further, the arithmetic unit 50 includes a distance measuring sensor 55 provided in the AFAE unit 31, a photometric sensor (photometric means) 56 for measuring the brightness of the subject, and a charge cam switch that is switched when a shutter charge is performed. (SW) 57, attached to the front curtain (not shown) of the focal plane shutter 33, and drives the front curtain switch (SW) 58 for detecting the fully open state of the shutter opening and the imager 35. An imager driving circuit 60 for driving the sub-imager 23, 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-viewfinder display LCD 26. And are connected.

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

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

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

  On the other hand, the interchangeable lens 80 drives and controls each unit in the interchangeable lens 80, and is configured by a CPU or the like and has a calculation unit 81 that is a data acquisition unit. 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 the focus lens 101 a 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 mechanism (aperture) 102 that is a light amount adjusting unit or a light amount control unit based on a photometric result of the photometric sensor 56 in the camera body 10. The focus pulse counter 87 detects the movement of the focus lens and controls the position when driving the focus lens. The zoom encoder 88 detects a movement signal corresponding to the focal length of a photographing lens (not shown) and outputs the movement signal to the calculation unit 81. Further, the memory 90 is a storage unit in which lens information in the interchangeable lens 80 is stored.

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

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

  The camera enters the through image mode when the operation dial 66 is operated to select the through image mode. Thereby, the through-image mode subroutine shown in FIG. 5 is operated from the main routine (not shown).

  FIG. 5 is a flowchart for explaining the operation of the camera in the through image mode in the embodiment of the present invention. The operation of this camera is mainly performed by the control of the calculation unit 50 in the camera body 10.

  When the through image mode routine is entered, first, in step S1, communication is performed with the interchangeable lens 80 side, and lens information of the interchangeable lens 80 is read from the calculation unit 81. This lens information is, for example, information such as a minimum aperture, an open aperture, and a focal length. Next, in step S2, the aperture is initially set. Here, an aperture other than the full aperture is set. In the second and subsequent times, the aperture value is set according to the aperture value changed in a subroutine “Aperture change” in step S6 described later.

  In step S3, when the sub imager 23 is turned on via the sub imager driving circuit 61, the subject image obtained by the sub imager 23 is read in the subsequent step S4. Further, in step S5, the subject image read in step S4 is displayed on the monitor 40. In this way, the through image display by the sub imager 23 is performed. Next, in step S6, the subroutine “aperture change” is executed.

  Here, the detailed operation of the subroutine “aperture change” in step S6 of the flowchart of FIG. 5 will be described with reference to the flowchart of FIG.

  When entering this subroutine, first, at step S21, the photometric sensor 56 measures the luminance distribution. Next, in step S22, it is determined whether or not the current aperture is open. If the aperture is full, the process proceeds to step S23, and if not, the process proceeds to step S26.

  In step S23, it is determined whether or not the subject has high brightness. Here, for example, it is determined whether or not the saturation region of the luminance distribution is 50% or more. As a result, if the brightness is high, the process proceeds to step S24 to determine whether or not the interchangeable lens 80 attached to the camera body 10 is a large aperture lens. Is brighter than 2.0. If the mounted interchangeable lens 80 is a large-diameter lens, the process proceeds to step S25, and the diaphragm 102 is narrowed down to the minimum diaphragm. Thereafter, the process exits from this routine and proceeds to step S7 in the flowchart of FIG. In step S25, the aperture is set to the minimum aperture. However, if the aperture value does not affect the imager 35, FNo. It may be about 8.0.

  On the other hand, in step S26, it is determined whether or not the low luminance limit is reached. Here, when it is determined that the low luminance limit is reached, the process proceeds to step S27 and the diaphragm 102 is opened by one stage. Thereafter, the process exits from this routine and proceeds to step S7 in the flowchart of FIG.

  If the low brightness limit is not reached in step S26, the brightness is not high in step S23, and if the lens is not a large-diameter lens in step S24, the process proceeds to step S28, and whether or not the stop 102 is the minimum stop. Is determined. As a result, if it is the minimum aperture, the routine is exited, and if not, the process proceeds to step S29. In step S29, it is determined whether or not the subject has high brightness. If the brightness is high, the process proceeds to step S30 and the diaphragm 102 is narrowed by one stage, and then the process exits from this routine and proceeds to step S7 in the flowchart of FIG. If the subject is not bright in step S29, step S30 is skipped and the routine is exited.

  In step S27 and S30, the diaphragm 102 is moved by one step, but the number of steps is not limited to one and may be plural.

  After the “aperture change” process is executed in step S6 in this manner, in step S7, the state of the first (1st) release switch, which is the half-pressed state of the above-described two-stage release switch 67, is executed. Is determined. If the first release switch is not turned on, the process proceeds to step S8, where it is determined whether the lens has been exchanged or the focal length has been changed. Here, if any operation is performed, the process proceeds to step S1 and the above-described processing operation is repeated. If not, the process proceeds to step S18 described later.

  On the other hand, if the first release switch is turned on in step S7, the process proceeds to step S9 to determine the AF state. As a result, if AF has not been completed yet, the process proceeds to step S10, where AF and AE are executed. Thereafter, the process proceeds to step S3, and the above-described processing operation is repeated. If AF is completed in step S9, the process proceeds to step S11, and 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 S3 and the above-described processing operation is repeated.

  If the second release switch is turned on in step S11, the process proceeds to step S12 and the monitor 40 is turned off. Subsequently, in step S13, the driving of the sub imager 23 is stopped. Further, in step S14, the main mirror 11 is raised by the shutter mirror drive motor 52. That is, it is moved from the photographing optical path as shown in FIG. 1 to the retracted position as shown in FIG. Next, in step S15, exposure by the imager 35, that is, imaging is performed. In step S16, the subject image captured by this imaging is read out.

  Thereafter, in step S17, the main mirror 11 is lowered by the shutter mirror drive motor 52 (return from the retracted position shown in FIG. 2 into the photographing optical path shown in FIG. 1). In step S18, it is determined whether or not a mode change has been performed. Here, if the through image mode is maintained without being changed, the process proceeds to step S3 and the above-described processing operation is repeated. When the mode is changed, the routine exits and returns to the main routine (not shown).

  As described above, according to the present embodiment, since the set aperture value in the through image mode is controlled, even when an extremely bright subject is framed in the screen when framing is determined, No more damage.

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

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of the present invention, and is a cross-sectional view illustrating a configuration of a main body portion of a digital single-lens reflex camera according to the present invention, illustrating a state during subject observation. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of the present invention, and is a cross-sectional view illustrating a configuration of a main body of a digital single-lens reflex camera according to the present invention, illustrating a state at the time of photographing. It is sectional drawing which shows the structure of the interchangeable lens of the digital single-lens reflex camera in one Embodiment of this invention. It is a block diagram which shows the structure of the electric system of the digital single-lens reflex camera which concerns on one Embodiment of this invention. 6 is a flowchart for explaining the operation of the camera in a through image mode in an embodiment of the present invention. 6 is a flowchart for explaining detailed operations of a subroutine “aperture change” in step S6 of the flowchart of FIG. 5.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 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)), 20 ... eyepiece lens, 22 ... re-imaging lens, 23 ... sub-imager, 25 ... display prism, 26 ... LCD for viewfinder display, 30 ... sub-mirror, 31 ... AFAE unit, 33 ... Focal plane shutter, 34 ... low pass filter, 35 ... imager, 36 ... imager plate, 38 ... substrate, 40 ... monitor, 41 ... monitor window, 42 ... body mount, 51 ... motor drive circuit, 52 ... shutter mirror drive motor, 53 ... shutter control circuit, 55 ... distance measuring sensor, 56 ... photometric sensor, 57 ... charge cam switch (SW), 8 ... front curtain switch (SW), 60 ... imager drive circuit, 61 ... sub-imager drive circuit, 62 ... monitor drive circuit, 63 ... LCD drive circuit, 65 ... operation button, 66 ... operation dial, 67 ... release switch (SW) , 69 ... Recording medium, 70 ... Memory, 71 ... Image data memory, 80 ... Interchangeable lens, 81 ... Calculation unit, 82 ... Motor drive circuit, 83 ... Focus motor, 84 ... Aperture drive circuit, 85 ... Aperture motor, 87 DESCRIPTION OF SYMBOLS: Focus pulse counter, 88 ... Zoom encoder, 90 ... Memory, 101 ... Shooting lens, 101a ... Focus lens, 101b ... Zoom lens, 102 ... Aperture mechanism (aperture), 105 ... Lens mount.

Claims (10)

In a digital single-lens reflex camera having a through image mode for continuously capturing and displaying subject images,
Interchangeable shooting lens,
An aperture mechanism for adjusting the amount of light incident on the subject through the photographing lens;
Data acquisition means for acquiring lens data including an open aperture value from the photographing lens;
Setting means for setting an initial value of the aperture mechanism based on the lens data acquired by the data acquisition means when the through image mode is set;
Photometric means for detecting subject brightness;
Changing means for changing the setting of the aperture value of the aperture mechanism based on the subject luminance data detected by the photometry means during execution of the through image display;
A digital camera comprising:   2. The digital camera according to claim 1, wherein the changing unit changes the aperture value by a predetermined number of steps according to a change in the subject brightness.   When the aperture of the aperture mechanism is open, the subject brightness is higher than a predetermined value, and the photographing lens is a large-diameter lens, the changing means narrows the aperture mechanism to a predetermined value. The digital camera according to claim 1.   The digital camera according to claim 1, wherein the photometry unit detects the subject luminance based on a luminance distribution of the through image. In digital SLR cameras with interchangeable lenses,
An image sensor capable of imaging every frame and continuous imaging at regular intervals;
Selection means for enabling selection of continuous imaging modes;
Storage means for storing information unique to the lens;
A light amount control means built in the interchangeable lens;
A measuring means for measuring the luminance state of the subject;
Comprising
The digital light single-lens reflex camera according to claim 1, wherein the light amount control means reduces the light amount when the subject luminance exceeds a predetermined value when a continuous imaging mode is selected.   6. The digital single-lens reflex camera according to claim 5, wherein the light quantity control means is constituted by a diaphragm member in the lens. In digital SLR cameras with interchangeable lenses,
An image sensor capable of imaging every frame and continuous imaging at regular intervals;
Selection means for enabling selection of continuous imaging modes;
Storage means for storing information unique to the lens;
A light amount control means built in the interchangeable lens;
A measuring means for measuring the luminance state of the subject;
Control means for setting the light quantity to a predetermined state by the light quantity control means based on the unique information of the mounted lens acquired by the information transmission means when a continuous imaging mode is selected; ,
Comprising
The digital light single-lens reflex camera, wherein the light amount control means controls the light amount when the luminance state of the subject exceeds a predetermined value while the continuous imaging mode is continued in the predetermined state.   The digital single-lens reflex camera according to claim 7, wherein the measurement unit is detection of a luminance distribution state of a captured image. In a digital single-lens reflex camera having a through image mode for continuously capturing and displaying subject images,
Interchangeable shooting lens,
An image sensor capable of imaging every frame and continuous imaging at regular intervals;
Selection means for enabling selection of continuous imaging modes;
A light amount adjusting means for adjusting a subject light amount incorporated in the interchangeable lens;
Photometric means for detecting the luminance state of the subject;
Control means for controlling to reduce the amount of light by the light amount adjusting means when the subject brightness detected by the photometric means exceeds a predetermined value when a continuous imaging mode is selected by the selecting means;
A digital single-lens reflex camera characterized by comprising:   The digital single-lens reflex camera according to claim 9, wherein the light amount adjusting unit is configured by a diaphragm member in the photographing lens.

Images