JP5215745B2 - Imaging apparatus and imaging method - Google Patents

Description

  The present invention relates to an imaging apparatus and an imaging method.

  The digital still camera (imaging device) includes, for example, a quick return mirror (movable reflection mirror), and does not include a single-lens reflex camera that guides light from the imaging optical system to the viewfinder side before shooting and a quick return mirror. There is a compact camera that guides light from an imaging optical system to an image sensor (photoelectric conversion element) before photographing.

  Some imaging devices perform focus control and exposure control before or during the main shooting. For example, Patent Document 1 discloses a technique for achieving both focus control and exposure control in the continuous shooting mode. Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for photographing a subject with light reflected by a semi-transmissive mirror and simultaneously detecting information related to photographing conditions. Further, Patent Document 3 discloses a technique for performing focus control at high speed during live view display before actual photographing.

JP 2008-52246 A JP 2008-14998 A JP 2007-310219 A

  By the way, in the digital single-lens reflex camera, before the actual photographing, light from the imaging optical system including a lens is reflected by a quick return mirror (movable reflection mirror) and guided to the viewfinder side. As a result, the user can check the framing of the subject through the viewfinder. However, before the actual photographing, the quick return mirror is in a so-called mirror-down state, and the light from the subject is blocked by the quick return mirror and does not enter the image sensor (for example, a CCD sensor, a CMOS sensor, etc.). Therefore, unlike a compact camera, a conventional digital single-lens reflex camera cannot measure light with an image sensor before the actual photographing.

  Some digital single-lens reflex cameras include an AF (auto focus) sensor sub-mirror on the back side of the quick return mirror, and the quick return mirror is a half mirror. The light from the subject that has passed through the half mirror is reflected by the AF sensor sub-mirror and guided to the AF sensor side. As a result, part of the light from the subject that has passed through the half mirror in the mirror-down state is blocked by the sub-mirror and is not guided to the image sensor side. For this reason, even if the quick return mirror is a half mirror, the entire subject image cannot be guided to the image sensor, so that the image signal output from the image sensor before the actual photographing cannot be used effectively.

  For this reason, in conventional digital single lens reflex cameras, exposure control and white balance control are performed before actual photographing by providing a photometric sensor or the like separately. In addition, photometry or colorimetry is performed after shooting by using the image signal after shooting.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is a new and improved technique capable of reliably and concisely measuring light from a subject before actual photographing. Another object of the present invention is to provide an imaging apparatus and an imaging method.

  In order to solve the above-described problem, according to an aspect of the present invention, unlike the first incident portion where the light from the subject is incident and the first incident portion, the second incident portion where the light from the subject is incident An incident portion and a photoelectric conversion element that receives light from the second incident portion before the main photographing and converts the subject image irradiated with the light from the first incident portion and irradiated onto the imaging surface during the main photographing into an electric signal. Then, the light from the first incident part is reflected on the one surface side in a different direction from the photoelectric conversion element before the main photographing, and the light from the second incident part on the other surface side opposite to the one surface side before the main photographing. And a light guide member that reflects the light to the photoelectric conversion element.

  With this configuration, light from the subject is incident on the first incident portion, and light from the subject is incident on the second incident portion different from the first incident portion. The light guide member reflects light from the first incident portion in a direction different from that of the photoelectric conversion element on one side before the main photographing. The light guide member reflects light from the second incident portion to the photoelectric conversion element on the other surface side opposite to the one surface side before the main photographing. The photoelectric conversion element receives light from the second incident portion before the main photographing, and light enters from the first incident portion during the main photographing, and the subject image irradiated on the imaging surface before the main photographing and during the main photographing. Is converted into an electrical signal.

  The light guide member is located on the optical path connecting the first incident portion and the photoelectric conversion element before the main photographing, blocks at least part of the light passing through the optical path, and moves during the main photographing to pass through the optical path. The light to be emitted may be released to the photoelectric conversion element side. With this configuration, at least a part of the light passing through the optical path connecting the first incident part and the photoelectric conversion element before the main photographing is blocked by the light guide member, and at least a part of the light from the first incident part Does not reach the photoelectric conversion element before the actual photographing. Further, when the light guide member is moved during the main photographing, the light passing through the optical path connecting the first incident portion and the photoelectric conversion element reaches the photoelectric conversion element.

  The light guide member may be a movable reflecting mirror that reflects light from the first incident portion to the viewfinder side on one side before the main photographing. With this configuration, the light from the first incident part before the main photographing is reflected to the viewfinder side by one surface side of the movable reflecting mirror as the light guide member.

  The light guide member may further include an optical element having a light reflection function or a light refraction function. With this configuration, the optical element having the light reflecting function or the light refracting function included in the light guide member reflects light from the first incident portion in a different direction from the photoelectric conversion element on one side before the main photographing. . In addition, the optical element having the light reflecting function or the light refracting function included in the light guide member transmits light from the second incident portion to the photoelectric conversion element on the other surface side opposite to the one surface side before the main photographing. reflect.

  In order to solve the above-described problem, according to another aspect of the present invention, the light from the subject is incident unlike the first incident portion where the light from the subject is incident and the first incident portion. Light is incident from the second incident portion and the second incident portion before the main photographing, and the subject image irradiated on the imaging surface by the light incident from the first incident portion at the time of the main photographing is converted into an electric signal. An imaging device is provided that includes a photoelectric conversion element and a light transmission member that guides light from a second incident portion to the photoelectric conversion element before actual imaging and transmits light from one end to the other end.

  With this configuration, light from the subject is incident on the first incident portion, and light from the subject is incident on the second incident portion different from the first incident portion. The light transmission member transmits light from one end portion to the other end portion, and guides light from the second incident portion to the photoelectric conversion element before actual photographing. The photoelectric conversion element receives light from the second incident portion before the main photographing, and light enters from the first incident portion during the main photographing, and the subject image irradiated on the imaging surface before the main photographing and during the main photographing. Is converted into an electrical signal.

  The photoelectric conversion element may have a control unit that performs exposure control or white balance control based on an electrical signal generated by light from the second incident unit before the main photographing. With this configuration, exposure control or white balance control is performed based on an electrical signal generated by the photoelectric conversion element using light from the second incident portion before the main photographing.

  The photoelectric conversion element may have a focus control unit that performs focus control based on an electric signal generated by light from the second incident unit before the main photographing. With this configuration, an electrical signal is generated by the light from the second incident portion in the photoelectric conversion element before the main photographing, and focus control is performed based on the generated electrical signal.

  The second incident part may change a range of light incident on the photoelectric conversion element from the second incident part according to an angle of view of the first incident part. With this configuration, the range of light that enters the photoelectric conversion element from the second incident portion changes according to the angle of view of the first incident portion.

  The second incident part has a lens, and a display control for displaying an image on the display part by an image signal based on an electric signal generated by the photoelectric conversion element by light from the second incident part before the main photographing. You may have a part. With this configuration, an electrical signal is generated by the light from the second incident portion in the photoelectric conversion element before the main photographing, and an image signal is generated by the generated electrical signal. Then, an image based on the generated image signal is displayed on the display unit.

  In order to solve the above-described problem, according to another aspect of the present invention, the step of reflecting light from the first incident portion on one surface side of the light guide member in a direction different from the imaging surface before the main photographing is performed. A step of reflecting light from a subject from a second incident part different from the first incident part before the main photographing on the other surface side opposite to the one surface side of the light guiding member; and a light guiding member before the main photographing. A step of converting the subject image irradiated with the light reflected by the light and irradiating the imaging surface into an electric signal, and exposure control or white based on the electric signal generated by the light from the second incident part before the main photographing. There is provided an imaging method including a step of performing balance control, and a step of converting a subject image irradiated with light from a subject from a first incident portion and irradiating the imaging surface into an electrical signal during main photographing.

  With this configuration, the light from the first incident part is reflected on the one surface side of the light guide member before the main photographing in a direction different from the imaging surface, and the second incident part is different from the first incident part before the main photographing. The light from the subject is reflected on the other surface side opposite to the one surface side of the light guide member. Then, the subject image irradiated with the light reflected by the light guide member before the main photographing and irradiated on the imaging surface is converted into an electric signal, and the electric generated by the light from the second incident portion before the main photographing is generated. Based on the signal, exposure control or white balance control is performed. Further, a subject image irradiated with light from the subject from the first incident portion and irradiated onto the imaging surface during the main photographing is converted into an electrical signal.

  In order to solve the above-described problem, according to another aspect of the present invention, the step of reflecting light from the first incident portion in a direction different from the imaging surface before the main photographing, and the first before the main photographing. A step of transmitting light from the subject from one end of the light transmitting member to the other end from a second incident portion different from the incident portion of the light, and light transmitted to the other end of the light transmitting member before the actual photographing is incident A step of converting the subject image irradiated on the imaging surface into an electric signal, and a step of performing exposure control or white balance control based on the electric signal generated by the light from the second incident unit before the main photographing. There is provided an imaging method including a step of converting a subject image irradiated with light from a subject from a first incident part and irradiated onto an imaging surface into an electrical signal at the time of actual photographing.

  With such a configuration, the light from the first incident part is reflected in a different direction from the imaging surface before the main photographing, and the light from the subject is reflected from the second incident part different from the first incident part before the main photographing. The light is transmitted from one end of the light transmission member to the other end. Then, the subject image irradiated with the light transmitted to the other end of the light transmission member before the main photographing and irradiated on the imaging surface is converted into an electric signal, and the light from the second incident portion before the main photographing. The exposure control or the white balance control is performed based on the electrical signal generated by. Further, a subject image irradiated with light from the subject from the first incident portion and irradiated onto the imaging surface during the main photographing is converted into an electrical signal.

  According to the present invention, the light from the subject can be reliably and concisely measured before the actual photographing.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(Configuration of one embodiment)
First, the configuration of the imaging apparatus 100 according to an embodiment of the present invention will be described. FIG. 1 is a block diagram illustrating an imaging apparatus 100 according to the present embodiment. The imaging device 100 is, for example, a digital single lens reflex camera.

  The imaging apparatus 100 includes, for example, an imaging optical system 101, a quick return mirror 105, a shutter 106, a CMOS sensor 107, an image input controller 110, an AF sensor 111, a sub lens 114, a sub mirror 115, and a DSP. / CPU 120, CPU 130, operation member 135, drivers 141, 143, 145, motors 142, 144, 146, image signal processing circuit 152, compression processing circuit 154, LCD driver 156, LCD 158, and VRAM 162 And SDRAM 164, media controller 166, recording medium 168, and the like.

  The imaging optical system 101 includes, for example, a zoom lens 102, a diaphragm 103, a focus lens 104, and the like. The imaging optical system 101 is an optical system that forms external light on the CMOS sensor 107 and transmits light from the subject to the CMOS sensor 107. The zoom lens 102 is a lens that changes the angle of view by changing the focal length. The angle of view of the zoom lens 102 may be adjusted by a user, or may be controlled by a motor and a driver (not shown). The diaphragm 103 is a mechanism that adjusts the amount of light transmitted therethrough, and is driven by a motor 142. The focus lens 104 moves in the optical axis direction to focus the subject image on the imaging surface of the CMOS sensor 107. The focus lens 104 is driven by a motor 144. The motors 142 and 144 are driven by receiving drive signals from the drivers 141 and 143, respectively.

  The quick return mirror 105 includes a half mirror member 105A that reflects incident light and transmits part of the incident light, an AF sub mirror 105B provided on the back surface (CMOS sensor 107) side of the half mirror member 105A, and the like. (See FIG. 2). As shown in FIG. 2, the quick return mirror 105 is in a so-called mirror-down state before the actual photographing, and is disposed on the optical path connecting the imaging optical system 101 and the CMOS sensor 107 to block the optical path. Further, the half mirror member 105A of the quick return mirror 105 reflects the light from the imaging optical system 101 toward the viewfinder 148 before the actual photographing (see FIG. 2). Further, the AF sub mirror 105B of the quick return mirror 105 reflects the light transmitted through the half mirror member 105A to the AF sensor 111 side before the main photographing.

  As shown in FIG. 3, the quick return mirror 105 is so-called mirror-up to open the optical path connecting the imaging optical system 101 and the CMOS sensor 107, and the light from the subject reaches the CMOS sensor 107 at the time of actual photographing. Let

  The shutter 106 is a mechanical shutter, and opens an optical path connecting the imaging optical system 101 and the CMOS sensor 107 so that light strikes the CMOS sensor 107 during actual photographing, and blocks light when not photographing. The shutter 106 controls the exposure time of the CMOS sensor 107. The quick return mirror 105 and the shutter 106 are driven and interlocked by a motor 146. The motor 146 is driven by receiving a drive signal from the driver 145.

  A CMOS (complementary metal oxide semiconductor) sensor 107 is an example of an image sensor, and includes a plurality of photoelectric conversion elements that photoelectrically convert light information transmitted through the imaging optical system 101 into electrical signals. Each photoelectric conversion element generates an electrical signal corresponding to the amount of light. The imaging device is not limited to a CMOS sensor, and a CCD (charge coupled device) sensor or the like can be applied. At this time, an electronic shutter (not shown) may be applied instead of the shutter 106. Note that the shutter 106 or the electronic shutter is operated by a switch of a shutter button (operation member 135) connected to the DSP / CPU 120.

  The CMOS sensor 107 further includes a CDS / AMP unit 108 and an A / D conversion unit 109. A CDS / AMP section (correlated double sampling circuit / amplifier) 108 removes low-frequency noise contained in the electrical signal output from the CMOS sensor 107, and at the same time outputs the electrical signal to an arbitrary level. Amplify until. The A / D conversion unit 109 digitally converts the electrical signal output from the CDS / AMP unit 108 to generate a digital signal. The A / D conversion unit 109 outputs the generated digital signal to the image input controller 110.

  The image input controller 110 performs processing on the digital signal output from the A / D conversion unit 109 to generate an image signal that can be processed. The image input controller 110 outputs the generated image signal to, for example, the image signal processing circuit 152. The image input controller 110 controls reading / writing of image data to / from the SDRAM 164.

  The AF sensor 111 is, for example, a line sensor in which a plurality of photoelectric conversion elements are arranged in a one-dimensional direction. The AF sensor 111 receives light from the AF sub mirror 105 </ b> B of the quick return mirror 105 before the actual photographing, and generates an electrical signal corresponding to the light amount. The AF sensor 111 outputs the generated electrical signal to the CPU 130. The AF sensor 111 further includes a CDS / AMP unit 112 and an A / D conversion unit 113.

  The sub lens 114 is provided in the main body of the imaging apparatus 100 and guides external light to the CMOS sensor 107 side before the main photographing. The sub mirror 115 receives light from the sub lens 114 and reflects the light to the quick return mirror 105.

  The DSP / CPU 120 and the CPU 130 function as an arithmetic processing device and a control device according to a program, and control processing of each component provided in the imaging device 100. The CPU 130 mainly operates before and during the main shooting, and the DSP / CPU 120 mainly operates after the shooting.

  For example, the CPU 130 outputs signals to the drivers 141, 143, and 145 based on focus control and exposure control to drive the imaging optical system 101, the quick return mirror 105, and the shutter 106. Further, the CPU 130 controls each component of the imaging apparatus 100 based on a signal from the operation member 135. The DSP / CPU 120 controls image processing for an image signal acquired by shooting.

  In the present embodiment, the DSP / CPU 120 and the CPU 130 are each composed of only one. However, a signal system command and an operation system command may be executed by separate CPUs. Good.

  As shown in FIG. 1, the DSP / CPU 120 includes, for example, a timing generator 121, a proper AWB calculation unit 122, an image processing selection unit 123, an SIO 124, and the like. The CPU 130 includes, for example, an image input controller 131, an AF calculation control unit 132, an AE calculation control unit 133, a GUI management unit 134, an SIO 136, and the like.

  The timing generator 121 outputs a timing signal to the CMOS sensor 107 and the CDS / AMP unit 108, and performs charge read control of each photoelectric conversion element constituting the CMOS sensor 107.

  The appropriate AWB calculation unit 122 calculates the WB control value based on the color information of the image signal corresponding to the subject image received by the CMOS sensor 107. For example, the appropriate AWB calculation unit 122 calculates the WB control value so that an appropriate white balance (WB) corresponding to the subject is obtained. The appropriate AWB calculation unit 122 sends the calculated WB control value to the image signal processing circuit 152.

  The image processing selection unit 123 selects whether or not to perform image processing such as gamma correction and contour enhancement processing on the image signal, and sets parameters necessary for each image processing. The image processing selection unit 123 sends the selection result and the set parameters to the image signal processing circuit 152.

  The image input controller 131 processes the digital signal output from the A / D conversion unit 113 and generates a signal that enables focus control. The image input controller 131 outputs the generated signal to, for example, the AF calculation control unit 132.

Upon receiving the focus control start operation signal, the AF calculation control unit 132 generates a control signal for moving the focus lens 104 in one direction, and outputs the generated control signal to the driver 143.
The AF calculation control unit 132 calculates an AF (auto focus) evaluation value, and further calculates a focus position of the focus lens 104 based on the AF evaluation value. The AF evaluation value is calculated based on the luminance value of the signal output from the AF sensor 111.
The AF calculation control unit 132 outputs the in-focus position obtained as a result of the calculation to the driver 143 as a control signal. The driver 143 generates a drive signal based on the control signal received from the AF calculation control unit 132. The driver 143 sends the generated drive signal to the motor 144.

  The AE calculation control unit 133 calculates an AE (auto exposure) evaluation value, and calculates the aperture amount of the aperture 103 and the shutter speed of the shutter 106 based on the calculated AE evaluation value. The AE evaluation value is calculated based on the luminance value of the CMOS sensor 107. The AE calculation control unit 133 outputs the calculated aperture amount and shutter speed to the drivers 141 and 145 as control signals, respectively. Drivers 141 and 145 generate drive signals based on control signals received from AE calculation control unit 133. The drivers 141 and 145 send the generated drive signals to the motors 142 and 146.

  The GUI management unit 134 manages a GUI (graphic user interface) such as a thumbnail screen of images displayed on the LCD 158 and a menu screen for operating the imaging apparatus 100. For example, the GUI management unit 134 receives an operation signal from the operation member 135 and sends a control signal based on the operation signal to the LCD driver 156.

  The SIOs 124 and 136 are input / output interfaces for inputting / outputting signals to / from each other.

  The operation member 135 is, for example, an up / down / left / right key, a power switch, a mode dial, or a shutter button provided in the imaging apparatus 100. The operation member 135 sends an operation signal to the CPU 130 or the like based on an operation by the user. For example, the shutter button can be half pressed, fully pressed, or released by the user. When the shutter button is half-pressed, it outputs an operation signal for starting focus control, and when the half-press is released, the focus control ends. The focus button outputs an operation signal for starting shooting when fully pressed.

  The image signal processing circuit 152 receives an image signal from the image input controller 110 and generates an image signal subjected to image processing based on a WB control value, a γ value, an edge enhancement control value, and the like. The compression processing circuit 154 receives the image signal before the compression process, and compresses the image signal in a compression format such as a JPEG compression format or an LZW compression format. The compression processing circuit 154 sends the image data generated by the compression processing to, for example, the media controller 166.

  For example, the LCD driver 156 receives image data from the VRAM 162 and displays an image on an LCD (liquid crystal display) 158. The LCD 158 is provided in the main body of the imaging device 100. The image displayed on the LCD 158 is, for example, an image before shooting (live view display) read from the VRAM 162, various setting screens of the image capturing apparatus 100, images captured and recorded, and the like. In the present embodiment, the LCD 158 is used as the display unit and the LCD driver 156 is used as the display drive unit. However, the present invention is not limited to this example, and may be an organic EL display, a display drive unit, or the like.

  A VRAM (video RAM) 162 is a memory for image display and has a plurality of channels. The VRAM 162 can simultaneously input image data for image display from the SDRAM 164 and output image data to the LCD driver 156. The resolution and maximum number of colors of the LCD 158 depend on the capacity of the VRAM 162.

  An SDRAM (synchronous DRAM) 164 is an example of a memory, and temporarily stores image data of a captured image. The SDRAM 164 has a storage capacity capable of storing image data of a plurality of images. The SDRAM 164 stores an operation program for the DSP / CPU 120. Reading and writing of images to and from the SDRAM 164 is controlled by the image input controller 110.

  The media controller 166 controls writing of image data to the recording medium 168 or reading of image data and setting information recorded on the recording medium 168. The recording medium 168 is, for example, an optical disc (CD, DVD, Blu-ray disc, etc.), a magneto-optical disc, a magnetic disc, a semiconductor storage medium, etc., and records photographed image data. The media controller 166 and the recording medium 168 may be configured to be detachable from the imaging apparatus 100.

  Note that a series of processing in the imaging apparatus 100 may be processed by hardware or may be realized by software processing by a program on a computer.

(Internal configuration and operation of one embodiment)
Next, with reference to FIGS. 2 to 5, an internal configuration and operation of the imaging apparatus 100 according to the present embodiment will be described. 2 and 3 are cross-sectional views illustrating the imaging apparatus 100 according to the present embodiment. 2 shows a state in which the quick return mirror 105 is mirrored up (hereinafter also referred to as “mirror up state”), and FIG. 3 shows a state in which the quick return mirror 105 is mirrored down (hereinafter also referred to as “mirror down state”). Say.) FIG. 4 is a front view showing an imaging surface of the CMOS sensor 107 according to the present embodiment, as viewed from the light incident side from the subject. FIG. 5 is a rear view showing the half mirror member 105A of the quick return mirror 105, as viewed from the CMOS sensor 107 side.

  As shown in FIGS. 2 and 3, the imaging apparatus 100 includes an imaging optical system 101, a quick return mirror 105, a CMOS sensor 107, an AF sensor 111, a sub lens 114, a sub mirror 115, a sub lens light shielding plate 116, and a pentaprism. 147 and finder 148.

  The imaging optical system 101 has a configuration that can be attached to and detached from the main body of the imaging apparatus 100. The imaging optical system 101 and the imaging apparatus 100 main body are connected by a connection unit 140. In a state where the imaging optical system 101 is removed, it can be said that the connection unit 140 is a first incident unit on which light from the subject is incident. In a state where the imaging optical system 101 is attached to the main body of the imaging apparatus 100, the imaging optical system 101 is the first incident portion.

  The quick return mirror 105 includes a half mirror member 105A, an AF sub mirror 105B, and a hinge 105C. The half mirror member 105A and the AF sub mirror 105B are fixed to the hinge 105C at, for example, an end portion, and rotate around the hinge 105C. The quick return mirror 105 is disposed on the optical path connecting the imaging optical system 101 and the CMOS sensor 107.

  The half mirror member 105A reflects or transmits part of the incident light. The half mirror member 105A reflects the light from the imaging optical system 101 to the pentaprism 147 side as shown by the optical path P in the mirror-down state as shown in FIG. Further, the half mirror member 105A transmits the light from the subject to the AF sub mirror 105B side as indicated by the optical path R in the mirror down state.

  Further, as shown in FIG. 5, a mirror film surface 22 is formed on the back surface of the half mirror member 105A. The mirror film surface 22 is an example of a light guide member, and is a mirror surface that allows only incident light to be reflected without being transmitted. The region 21 other than the mirror coating surface 22 on the back surface of the half mirror member 105A is not coated with a mirror coating and has half mirror performance. The mirror coating surface 22 of the half mirror member 105A reflects the light from the sub lens 114 reflected by the sub mirror 115 as shown by the optical path Q to the CMOS sensor 107 side in the mirror down state as shown in FIG.

  The AF sub-mirror 105B reflects light incident from the half mirror member 105A side to the AF sensor 111 side in the mirror-down state.

  In the mirror-up state, the lower end of each of the half mirror member 105A and the AF sub mirror 105B moves to the upper side of the imaging device 100, the optical path S from the imaging optical system 101 to the CMOS sensor 107 is opened, and the subject From the imaging optical system 101 reaches the CMOS sensor 107 directly.

  In the mirror-down state, the CMOS sensor 107 receives light on the optical path Q that is reflected by the mirror film surface 22 of the half mirror member 105A and avoids the AF sub-mirror 105B. The light in the optical path Q is light guided from the sub lens 114 and forms an image as the image circle 12 shown in FIG. 4 on the imaging surface of the CMOS sensor 107. The image circle 12 forms an image not on the entire surface of the CMOS sensor 107 but on a partial region of the CMOS sensor 107. Thereby, the subject image can be formed on the CMOS sensor 107 even in the mirror-down state.

  In the mirror-up state, the CMOS sensor 107 receives the light of the optical path S guided from the imaging optical system 101. The light in the optical path S forms an image on the imaging area 11 shown in FIG. 4 on the imaging surface of the CMOS sensor 107. The light from the subject incident through the imaging optical system 101 forms an image in the imaging area 11 so that the subject can be photographed.

  In the mirror-down state, the AF sensor 111 receives the light of the optical path R guided from the AF sub mirror 105B. The light in the optical path R does not overlap the optical path Q described above. The AF sensor 111 performs calculation or control for focus control based on the light in the optical path R.

  The sub lens 114 receives light from the subject and introduces light to the sub mirror 115 side. In the mirror-down state, as shown in FIG. 2, unlike FIG. 3, the sub-lens light shielding plate 116 is opened. Therefore, the light from the sub lens 114 reaches the sub mirror 115 and is guided to the quick return mirror 105 and the CMOS sensor 107 side.

  On the other hand, in the mirror-up state, as shown in FIG. 3, the sub-lens light shielding plate 116 is blocked, and the light from the sub-lens 114 is blocked like the optical path T without reaching the sub-mirror 115. . Therefore, in the mirror-up state, only the light from the imaging optical system 101 reaches the CMOS sensor 107.

  The sub lens 114 may focus the subject image on the imaging surface of the CMOS sensor 107 in a mirror-down state. Thereby, even if the imaging apparatus 100 is a single-lens reflex camera, the subject image can be displayed in live view on the LCD 158 before the actual photographing.

  The sub lens 114 may be driven according to the angle of view of the imaging optical system 101 to adjust the imaging range of the CMOS sensor 107 in a mirror-down state. Thus, it is possible to more accurately acquire the light information of the subject necessary for the main shooting before the main shooting. For example, an AE (auto exposure) sensor provided in a conventional single-lens reflex camera can be omitted. Note that, instead of driving the sub lens 114 to optically adjust the imaging range, the CMOS sensor 107 selects a signal to be extracted according to the angle of view of the imaging optical system 101 and adjusts the imaging range. Also good.

  The sub mirror 115 is an example of a light guide member, and reflects light from the sub lens 114 to the quick return mirror 105 in a mirror-down state. In the present embodiment, the case where the sub mirror 115 is provided has been described. However, another optical element may be used, and a prism or the like may be provided. The sub-lens light shielding plate 116 opens the light from the sub-lens 114 as in the optical path Q in the mirror-down state, and blocks the light from the sub-lens 114 as in the optical path T in the mirror-up state.

  The pentaprism 147 receives light from the quick return mirror 105 in the mirror-down state, reflects the light, and guides the light to the finder 148 like an optical path P. The viewfinder 148 can confirm the framing of the subject in the mirror-down state.

(Image processing operation of one embodiment)
Next, with reference to FIG. 6, the photographing processing operation of the imaging apparatus 100 of the present embodiment will be described. FIG. 6 is a flowchart showing an imaging processing operation of the imaging apparatus 100 of the present embodiment.

  First, the imaging apparatus 100 starts driving when the power is turned on (step S101). Further, the CMOS sensor (image sensor) 107 enters a sleep (standby) state (step S102). Until the shutter button is half-pressed by the user, the CMOS sensor 107 continues in a standby state (step S103).

  When the shutter button is half-pressed by the user (step S103), the AF sensor 111 and the AF calculation control unit 132 start AF distance measurement for focus control (step S104).

  Simultaneously with step S104, the CMOS sensor 107 is driven (step S105), and the light from the sub lens 114 is received by the photometric area 13 shown in FIG. When the CMOS sensor 107 acquires data corresponding to the photometric area 13 (step S106), the imaging apparatus 100 performs statistical processing for automatic exposure control (AE) and white balance control (AWB) (step S106). As a result, control values for automatic exposure and white balance control can be acquired before actual photographing.

  The above statistical processing is repeated while the shutter button is kept half pressed (step S108). When the half-press of the shutter button is released, the state immediately after the imaging apparatus 100 is turned on is restored.

  On the other hand, when the user fully presses the shutter button, the process shifts to the actual photographing operation (step S109). First, the quick return mirror (movable reflection mirror) 105 mirrors up with the AF sub-mirror 105B (step S110). Then, the sub-lens light blocking plate 116 blocks the optical path (step S111), and the CMOS sensor 107 performs an exposure process (step S112).

  After the exposure is completed, the imaging apparatus 100 acquires capture data (step S113), and performs exposure control and white balance control based on control values for automatic exposure and white balance control during capture (step S114). The quick return mirror 105 is mirrored down together with the AF sub-mirror 105B (step S115), and the sub-lens light-shielding plate 116 releases the optical path (step S116). Thereafter, the imaging apparatus 100 returns to the initial state.

  The exposure control and white balance control in step S114 are performed based on the photometric data in the CMOS sensor 107 before the main photographing and the control value calculated from the image data acquired by the main photographing.

  In the operation shown in FIG. 6, the AF distance measurement and the data acquisition of the photometry area 13 are not related, but the present embodiment is not limited to this example. For example, the drive sequence of the focus lens 104 may be changed when the data acquired in the photometric area 13 is the photometric result of the ambient light or the colorimetric data. Specifically, if the BV value is 10 or more and the color temperature is 5000 to 6000K, the focus lens 104 may focus from infinity because there is a high possibility of outdoor landscape photography. Thereby, it is possible to shorten the time until focusing.

  Further, since the photometry is performed using the CMOS sensor 107, the color information of the subject can be acquired before the actual photographing. Therefore, it is possible to estimate whether the shooting state is indoor or outdoor by white balance control. In the present embodiment, the dynamic range of the AF sensor 111 for focus control can also be adjusted based on the result.

  As described above, according to the present embodiment, it is possible to measure light from a subject before the main photographing without providing another sensor in addition to the photoelectric conversion element that converts the subject image into an electrical signal during the main photographing. The light information (luminance information, color information) of the subject can be acquired. In particular, since the CMOS sensor 107 is used, statistical processing relating to exposure control and white balance control can be performed before the actual photographing. As a result, the performance of exposure control and white balance control in the imaging apparatus 100 can be improved.

  For example, in a conventional digital single-lens reflex camera, since a CMOS sensor could not be used before the main shooting, white balance control was performed only based on image data acquired by the main shooting. According to this, it is possible to perform processing using image data during framing before actual photographing.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, the second incident portion is the sub lens 114 having a lens function, but the present invention is not limited to such an example. The second incident part only needs to receive light from a subject, and may be a flat transparent member such as a glass plate or a plastic plate. Even in this case, if the CMOS sensor 107 can receive light from the subject in the mirror-down state before the main photographing, the light information of the subject at the main photographing can be acquired.

  Further, the second incident portion may be a light transmission member that transmits light from one end portion to the other end portion, for example, an optical fiber. Thereby, the light transmission path can be freely set inside the imaging apparatus 100. As a result, it is possible to freely determine the position of the light receiving surface that receives light from the subject as compared with the case where the second incident member is a lens or the like.

It is a block diagram showing an imaging device concerning one embodiment of the present invention. It is sectional drawing which shows the imaging device which concerns on the same embodiment. It is sectional drawing which shows the imaging device which concerns on the same embodiment. It is a front view which shows the imaging surface of the CMOS sensor which concerns on the same embodiment. It is a rear view which shows the half mirror member of the quick return mirror which concerns on the same embodiment. It is a flowchart which shows the imaging | photography process operation of the imaging device of the embodiment. It is a flowchart which shows the imaging | photography process operation of the imaging device of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Imaging device 101 Imaging optical system 102 Zoom lens 103 Diaphragm 104 Focus lens 105 Quick return mirror 105A Half mirror member 105B AF sub mirror 106 Shutter 107 CMOS sensor 108, 112 CDS / AMP part 109, 113 A / D conversion part 110, 131 Image Input Controller 114 Sub Lens 115 Sub Mirror 116 Sub Lens Shading Plate 120 DSP / CPU
121 Timing generator 130 CPU
135 Operation member 141, 143, 145 Driver 142, 144, 146 Motor 147 Penta prism 148 Finder 152 Image signal processing circuit 154 Compression processing circuit 156 LCD driver 158 LCD
162 VRAM
164 SDRAM
166 Media controller 168 Recording media

Claims (11)

A first incident portion on which light from the subject is incident;
Unlike the first incident portion, a second incident portion where light from the subject is incident;
A photoelectric conversion element that converts light from the second incident portion before the main photographing and converts the subject image irradiated with the light from the first incident portion and irradiated onto the imaging surface during the main photographing into an electrical signal;
Before the actual photographing, the light from the first incident part is reflected in a different direction from the photoelectric conversion element on one surface side, and the second incident on the other surface side opposite to the one surface side before the actual photographing. An imaging device having a light guide member that reflects light from the unit to the photoelectric conversion element.   The light guide member is located on an optical path connecting the first incident portion and the photoelectric conversion element before the main photographing, blocks at least a part of the light passing through the optical path, and moves during the main photographing. The imaging apparatus according to claim 1, wherein the light passing through the optical path is opened to the photoelectric conversion element side.   The imaging device according to claim 1, wherein the light guide member is a movable reflection mirror that reflects light from the first incident portion toward the viewfinder side on one surface side before the main photographing.   The imaging device according to claim 1, wherein the light guide member further includes an optical element having a light reflection function or a light refraction function. A first incident portion on which light from the subject is incident;
Unlike the first incident portion, a second incident portion where light from the subject is incident;
A photoelectric conversion element that converts light from the second incident portion before the main photographing and converts the subject image irradiated with the light from the first incident portion and irradiated onto the imaging surface during the main photographing into an electrical signal;
An imaging apparatus comprising: a light transmission member that guides the light from the second incident portion to the photoelectric conversion element before the main photographing, and transmits the light from one end portion to the other end portion.   6. The control unit according to claim 1, further comprising: a control unit that performs exposure control or white balance control based on the electrical signal generated by the photoelectric conversion element using light from the second incident unit before the main photographing. The imaging device described in 1.   7. The focus control unit according to claim 1, further comprising: a focus control unit configured to perform focus control based on the electric signal generated by the photoelectric conversion element by light from the second incident unit before the main photographing. Imaging device.   The said 2nd incident part changes the range of the light which injects into the said photoelectric conversion element from the said 2nd incident part according to the angle of view of the said 1st incident part, The any one of Claims 1-7 The imaging device described in 1. The second incident part has a lens,
9. The display control unit according to claim 1, further comprising: a display control unit configured to display an image on a display unit by an image signal based on the electrical signal generated by the photoelectric conversion element by the light from the second incident unit before the main photographing. The imaging device according to any one of the above. Reflecting light from the first incident portion on one surface side of the light guide member in a different direction from the imaging surface before the main photographing;
Reflecting light from a subject from a second incident portion different from the first incident portion before the main photographing on the other surface side opposite to the one surface side of the light guide member;
Converting the subject image irradiated with the light reflected by the light guide member and irradiated on the imaging surface before the main photographing into an electrical signal;
Performing exposure control or white balance control based on the electrical signal generated by the light from the second incident part before the main photographing;
And a step of converting a subject image irradiated with light from the subject from the first incident portion and irradiating the imaging surface into an electrical signal during main photographing. Reflecting light from the first incident portion in a direction different from the imaging surface before the main photographing;
Transmitting light from a subject from a second incident part different from the first incident part to the other end part of the light transmission member before the main photographing;
Converting the subject image irradiated on the imaging surface upon incidence of the light transmitted to the other end of the light transmission member before the main photographing into an electrical signal;
Performing exposure control or white balance control based on the electrical signal generated by the light from the second incident part before the main photographing;
And a step of converting a subject image irradiated with light from the subject from the first incident portion and irradiating the imaging surface into an electrical signal during main photographing.

Images