JP4795306B2 - Photometric device and camera - Google Patents

Description

  The present invention relates to a photometric device and a camera.

  In general, it is important to appropriately determine the brightness of the object field and perform appropriate exposure in order to obtain an image with good image quality when shooting with a camera.

  However, there are situations where it is difficult to perform appropriate exposure for the camera, such as backlight, point light source, and scenes with a large luminance difference. In order to maintain stable exposure accuracy even under such adverse conditions, photometric means for measuring the brightness by dividing the object scene into a plurality of areas is provided, and an appropriate exposure is obtained from the output of each area. Conventionally, cameras capable of guiding the brightness of a field are known. In addition, according to such a camera, it is possible to enjoy the advantage that the subjects whose photometry is stable and which are not good can be reduced.

  FIGS. 17A to 17C are diagrams showing a concept of dividing an object field in photometry performed by dividing the object field into a plurality of regions. 17A is a diagram showing an example in which the object scene is divided into two parts, FIG. 17B is a diagram showing an example in which the object scene is divided into nine parts, and FIG. It is a figure which shows the example which divided the field into 48.

  Note that the numbers given to the respective areas in the object scene shown in FIGS. 17A to 17C are the area numbers assigned to the respective areas.

  First, with reference to FIG. 17A, photometry when the object scene is divided into two will be described. The two-divided scene A is composed of pixels of area number 1 and area number 2. Here, the pixel of area number 2 is a circular pixel in the center of the object scene. The pixel with area number 1 is a pixel in the area around the pixel with area number 2 (the area excluding the area of pixel 1 in the two-segment object A).

  Here, when the subject X is located at the center of the two-divided field A, the pixel with the region number 2 looks at the brightness of the subject X, and the pixel with the region number 1 looks at the background. Will be. However, when the subject X is located at a position away from the center of the two-segment scene A, the ratio of the subject viewed by each pixel to the background changes according to the position. That is, for example, when the subject X is dark and the subject X is dark, it is determined that the data in the pixel of the region number 2 is brighter as the subject X is located at a position farther from the center of the two-segment scene A. Become. That is, the exposure changes depending on the position of the subject X in the two-part scene A.

  Considering that the subject X is exposed with the brightness adjusted, and when the number of divisions is small as in the two-part scene A, if the luminance difference between the background and the subject X is large, The photometric data changes depending on the position of the subject X.

  Next, with reference to FIG. 17B, a case where the object scene is divided into nine parts will be described. As shown in the figure, the nine-division object field B is composed of pixels of region number 1 to region number 9 arranged in the row and column directions. Here, the region number 1 pixel to the region number 9 pixel are pixels that occupy regions of the same area in the nine-divided field B, respectively.

  As can be seen by comparing FIG. 17A and FIG. 17B, when the object scene is divided into nine parts, it is slightly improved as compared with the case where the object field is divided into two parts. The exposure still changes depending on the position of the subject X in the field.

  Next, a case where the object scene is divided into 48 is described with reference to FIG. The 48-divided field C is composed of pixels of region number 1 to region number 48 arranged in the row and column directions as shown in FIG. Here, the region number 1 pixel to the region number 48 pixel are pixels that occupy regions of the same area in the 48-divided field C.

  Here, according to the 48-divided scene C, even if the subject X is not located at the center of the 48-divided scene C, as can be seen from FIG. The ratio does not change much. In other words, when the object scene is divided into 48, since the area occupied by each pixel is small, in most pixels, either the subject X or the background is measured over almost the entire area. Even in the case of movement, the object of photometry at a certain pixel is simply switched from the subject X to the background or from the background to the subject X. That is, according to the 48-divided field C, if it is possible to determine which pixels measure the subject X, it is possible to perform exposure according to the subject X.

  As described above, in the photometric sensor, the exposure of the subject X can be accurately grasped as the number of divisions of the object field increases, so that stable exposure can be performed.

  However, the increase in the number of divisions of the object field, from the technical viewpoint, increases the amount of calculation, complicates photometric means, increases the cost, and decreases the amount of received light per pixel, etc. It makes it difficult to maintain the photometric range and photometric accuracy.

For example, Patent Document 1 discloses the following photometric device as a technique related to the division of the object scene. That is, according to the technique disclosed in Patent Document 1, it is a photometric device that assumes that the main subject is in the center of the subject, and particularly enables the main subject to be distinguished in size. The most suitable calculation method is selected from a plurality of set photometric value calculation methods according to the size of the image, and the luminance information of the outer area of the field that is particularly prone to adding inappropriate elements is displayed. By obtaining the luminance information from which the luminance of the element is removed, a photometric device capable of calculating an appropriate photometric value for the main subject is provided.
Japanese Examined Patent Publication No. 4-66302

  By the way, when the shape of the pixel of each divided area in the object scene is different from each other, the following problem occurs.

  First, when changing the division of the object scene, that is, when changing the shape of each region formed by the division of the object scene, it is difficult to utilize data accumulated in the past.

  In other words, considering that the output tendency of each pixel changes depending on the shape of each pixel, for example, when the design technique of the photometric means is improved, and in the division of the object field, it is possible to divide the scene more than before, Since it is difficult to utilize data accumulated in the past, it is necessary to newly collect data.

  Secondly, for example, when the photometric means is configured by providing a plurality of light receiving elements such as photodiodes (hereinafter referred to as PDs), PDs having different shapes are used. Differences in sensitivity occur due to differences in the light receiving area in the light source, and characteristics such as dark current, light and current linearity, and parasitic capacitance also differ from each other.

  That is, since a mechanism for correcting these differences is required for each pixel, the circuit becomes complicated, resulting in an increase in cost of the photometric means and a deterioration in space efficiency.

  Third, when the number of divisions of the object scene is increased, the amount of calculation, the calculation time, and the storage area increase, and it becomes difficult to maintain the photometric accuracy in each pixel. In addition, the light receiving area is reduced, and the photometric accuracy with low luminance is lowered. On the other hand, when the number of divisions of the object scene is reduced, it is greatly affected by a partial high-luminance part such as a point light source.

  And the technique currently disclosed by the said patent document 1 has the above problems.

  The present invention has been made in view of the above circumstances, and is configured by dividing an object field into efficient photometric distributions to improve photometric accuracy and photometric stability with respect to various subjects, and the photometry An object is to provide a camera including the apparatus.

  In order to achieve the above object, a photometric device according to the first aspect of the present invention is based on a multi-division photometry unit that performs photometry by dividing an object field into a plurality of areas, and an output of the multi-division photometry unit. And a calculation means for calculating a luminance value of the object scene, wherein the multi-division photometry means is equally divided corresponding to a plurality of photometry areas obtained by dividing the object field equally in the vertical direction and the horizontal direction, respectively. An area and a small area having a smaller area than the equally divided area and provided in the center of the equally divided area on the light receiving surface, and a photometric value in the equally divided area and the small area A photometric value is output.

  In order to achieve the above object, a camera according to a second aspect of the present invention is based on multi-division photometry means for measuring light by dividing an object field into a plurality of areas, and based on the output of the multi-division photometry means, Exposure control based on a photometric device having an arithmetic means for calculating a luminance value of the object scene, an optical system for guiding a light beam from a subject to the photometric device, and a luminance value output from the photometric device An exposure control unit for performing, and the multi-division photometry means is an equal division area corresponding to a plurality of photometry areas obtained by equally dividing the object field in the vertical direction and the horizontal direction, and more than the equal division area. A small area having a small area and provided in the center of the equally divided area on the light receiving surface, and outputting a photometric value in the equally divided area and a photometric value in the small area. And

  According to the present invention, it is possible to provide a photometric device that divides an object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects, and a camera including the photometric device. Can do.

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

  First, the system configuration of the camera according to the present embodiment will be described. FIG. 1 is a diagram illustrating an example of a system configuration of a camera according to the present embodiment. Here, a single-lens reflex camera (hereinafter simply referred to as a camera) will be described as an example of the camera.

  As shown in FIG. 1, the camera according to the present embodiment includes a body unit 100, a replaceable lens unit 112 connected to the body unit 100 via a communication connector 106, and the strobe communication connector 185. And an external strobe unit 180 connected to the body unit 100. In addition, a recording medium 139 for recording image data acquired by photographing is attached via the communication connector 135.

  The lens unit 112 includes photographing lenses 112a and 112b, a diaphragm 103, a lens driving mechanism 102, a diaphragm driving mechanism 104, and a lens control microcomputer 105 (hereinafter abbreviated as “Lucom”).

  The photographing lenses 112 a and 112 b are driven in the optical axis direction by a DC motor in the lens driving mechanism 102.

  The diaphragm 103 is driven by a stepping motor in the diaphragm drive mechanism 104.

  The Lucom 105 drives and controls each part of the lens unit 112 such as the lens driving mechanism 102 and the diaphragm driving mechanism 104. The Lucom 105 is electrically connected to a body control microcomputer 150 (hereinafter abbreviated as “Bucom”) 150 via the communication connector 106, and is controlled according to a command from the Bucom 150. Details of the operation control by the Bucom 150 will be described later.

  The body unit 100 includes a shutter unit 21, an imaging module 22, a quick return mirror 113b, a pentaprism 113a, a sub mirror 113d, an eyepiece lens 113c, a mirror driving mechanism 118, an AF sensor driving circuit 130b, an AF Sensor unit 130a, photometry circuit 132, image sensor interface circuit 134, liquid crystal monitor 136, SDRAM 138, image processing controller 140, shutter drive control circuit 148, body control microcomputer 150, and camera operation switch 152 A power supply circuit 153, a battery 154, and an operation display LCD 157.

  Here, a light beam from a subject (not shown) is incident on the body unit 100 through the photographing lenses 112 a and 112 b and the diaphragm 103 of the lens unit 112. Then, this light beam is reflected by the quick return mirror 113b, and forms an image on a focusing screen (not shown) disposed in the optical path between the pentaprism 113a and the quick return mirror 113b. The image formed on the focusing screen enters the eyepiece lens 113c through the pentaprism 113a.

  Since the quick return mirror 113b is a half mirror, even if the quick return mirror 113b is located at the down position (position shown in FIG. 1), a part of the light beam is part of the quick return mirror 113b. Transparent. The quick return mirror 113b is normally located at the down position.

  The light beam transmitted through the quick return mirror 113b is reflected by the sub mirror 113d installed on the quick return mirror 113b and guided to the AF sensor unit 130a for automatic ranging.

  When the quick return mirror 113b is positioned at the up position (the position retracted from the optical axis of the light beam incident on the body unit 100 via the photographing lenses 112a and 112b), the sub mirror 113d is moved to the quick mirror. It is configured to be folded and housed in close contact with the return mirror 113b.

  By the way, on the rear side (photographer side) of the quick return mirror 113b, an imaging module containing a focal plane type shutter unit 21 on the optical axis and an imaging element for photoelectrically converting a subject image that has passed through the optical system. 22 are provided. When the quick return mirror 113b is located at the up position, the light flux that has passed through the photographing lenses 112a and 112b is imaged on an image sensor (not shown) provided in the image pickup module 22.

  Here, the imaging device interface circuit 134 connected to an imaging device (not shown) provided in the imaging module 22, the SDRAM 138 provided as a storage area, the liquid crystal monitor 136, and the recording medium 139 are images. It is connected to the image processing controller 140 for performing processing. The recording medium 139 is an external recording medium, and is attached to the body unit 100 so as to be communicable via the communication connector 135.

  That is, the image sensor interface circuit 134, the SDRAM 138, the liquid crystal monitor 136, the recording medium 139, and the image processing controller 140 provide an electronic imaging function and an electronic recording display function.

  The image processing controller 140 includes the communication connector 135, the photometry circuit 132, the mirror drive mechanism 118, the AF sensor drive circuit 130b, the shutter drive control circuit 148, a nonvolatile memory (not shown), and the like. It is connected to the Bucom 150 for controlling each part in the body unit 100. The non-volatile memory (not shown) is means for storing predetermined control parameters necessary for camera control, and is provided so as to be accessible from the Bucom 150.

  The Bucom 150 has a timer function that measures the shooting interval during continuous shooting, controls the overall operation of the camera, and includes a coefficient counting function, a mode setting function, a detection function, a determination function, a calculation function, and the like. Has various functions.

  Further, the Bucom 150 is connected with an operation display LCD 157 for notifying the photographer of the operation state of the camera by display output, and a camera operation switch 152 for operating the camera. Further, the battery 154 is connected to the Bucom 150 via the power supply circuit 153. Here, the power supply circuit 153 is provided in order to convert the voltage of the battery 154 as a power supply into a voltage required for each circuit unit in the camera and supply it.

  The camera operation switch 152 operates the camera, such as a release switch for instructing execution of a shooting operation, a mode change switch for switching the shooting mode to a continuous shooting mode, a normal shooting mode, or the like. It is composed of a group of switches including various operation buttons (photographing operation means) necessary for this purpose.

  Here, the Bucom 150 and the Lucom 105 are electrically connected to each other via the communication connector 106 when the lens unit 112 is attached to the body unit 100. As a camera, the Lucom 105 is configured to operate in cooperation with the Bucom 150 in a dependent manner.

  Hereinafter, a configuration relating to photometry in the camera according to the present embodiment will be described with reference to FIG.

  The photometric circuit 132 is a circuit that performs photometric processing based on the light flux from the pentaprism 113a. The photometric circuit 132 has a multi-division photometric sensor that divides the object scene into a plurality of parts and measures the object field luminance.

  On the other hand, the mirror driving mechanism 118 is a mechanism for driving and controlling the quick return mirror 113b. The AF sensor driving circuit 130b is a circuit for driving and controlling the AF sensor unit 130a.

  The shutter drive control circuit 148 controls the movement of the front curtain and rear curtain in the shutter unit 21 and controls the opening / closing operation of the shutter with the Bucom 150. In addition, the shutter drive control circuit 148 exchanges a signal that synchronizes with the strobe unit 180.

  Each unit in the camera having the above-described configuration operates as follows, for example.

  First, the image sensor interface circuit 134 is controlled by the image processing controller 140 in accordance with a command from the Bucom 150, and image data is captured from the imaging module 22.

  This image data is taken into the SDRAM 138 which is a temporary storage memory. The SDRAM 138 is used as a work area when image data is converted. The image data is converted into JPEG data and stored in the recording medium 139.

  As described above, the mirror driving mechanism 118 is a mechanism for driving the quick return mirror 113b to the up position and the down position. Here, when the quick return mirror 113b is positioned at the down position by the mirror driving mechanism 118, the light flux from the photographing lenses 112a and 112b is divided into the AF sensor unit 130a side and the pentaprism 113a side. Led.

  Here, an output from an AF sensor (not shown) provided in the AF sensor unit 130a is transmitted to the Bucom 150 via the AF sensor driving circuit 130b, and a known distance measurement process is performed.

  Further, the photographer can visually observe a subject (not shown) by the eyepiece lens 113c provided adjacent to the pentaprism 113a. Further, a part of the light beam that has passed through the pentaprism 113a is guided to a photosensor (not shown) provided in the photometry circuit 132, and will be described later based on the amount of light detected by the photosensor (not shown). Photometric processing is performed.

  2A and 2B are diagrams schematically showing the above-described optical system. Here, the relationship between the quick return mirror 113b and the photometric process will be described with reference to FIG.

  That is, as shown in FIG. 2A, when the quick return mirror 113b is in the down position (state A; during non-exposure), the luminous flux of the image formed on the focusing screen 113f is the pentaprism 113a. By this, the eyepiece 113c and the photosensor (not shown) provided in the photometric circuit 132 are guided.

  On the other hand, as shown in FIG. 2B, when the quick return mirror 113b is in the up position (state B; during exposure), a light beam from a subject (not shown) is provided in the body unit 100. The light enters an image pickup device (not shown) in the image pickup module 22.

  Here, at the time of non-exposure, light incident from the photographing lenses 112a and 112b is reflected by the quick return mirror 113b at the down position and guided to the eyepiece lens 113c. At this time, part of the light also enters the multi-division photometric sensor of the photometric circuit 132.

  Then, in such a non-exposure state, the user visually recognizes a subject (not shown) from the eyepiece and determines the composition.

  On the other hand, at the time of exposure, the quick return mirror 113b is driven to the up position, and the light that has passed through the photographing lenses 112a and 112b is directly incident on the imaging element (not shown) in the imaging module 22. Here, when the shutter in the shutter unit 21 is opened, light enters the image sensor (not shown), and exposure is started. Then, when the shutter in the shutter unit 21 is closed, light stops entering the image sensor (not shown), and thus exposure stops.

  In the case of continuous shooting, operation control for repeating the non-exposure state and the exposure state is performed.

  The strobe unit 180 includes a strobe control microcomputer (hereinafter abbreviated as “Sucom”) 183, a flash light emitting unit 181, a light emission control circuit 182, and a battery 184. The strobe unit 180 is mounted so as to be communicable with the body unit 100 via a strobe communication connector 185.

  When the shutter drive control circuit 148 receives a signal for driving the shutter from the Bucom 150, the shutter drive control circuit 148 controls the drive of the shutter unit 21 based on the signal. At this time, a light emission signal for causing the strobe to emit light is output by the shutter drive control circuit 148 to the Sucom 183 and the light emission control circuit 182 through the strobe communication connector 185 at a predetermined timing. Based on the light emission signal, the Bucom 150 outputs a light emission command signal corresponding to the light emission mode to the Sucom 183 and the light emission control circuit 182 by communication.

  When the mode change switch of the camera operation switch 152 is operated by the photographer to change the mode from the shooting mode to the image display mode, the image data recorded on the recording medium 139 is read out. It is.

  The image data read from the recording medium 139 in this way is converted into a video signal by the image processing controller 140 and output and displayed on the liquid crystal monitor 136.

  Hereinafter, dimming by the strobe unit 180 will be described.

  First, as a general dimming, pre-emission dimming control can be exemplified. According to this pre-flash dimming control, pre-flash that emits a strobe before shooting is performed. The amount of light emitted during the main photographing is calculated from the amount of reflected light that passes through the photographing lenses 112a and 112b and reaches the photosensor (not shown) provided in the photometry circuit 132 from the subject during the pre-light emission. Determined.

  The photo sensor (not shown) receives a light beam from the subject (not shown) via the lens unit 112, the quick return mirror 113b, and the pentaprism 113a. A plurality of PDs are arranged on the light receiving surface of the photosensor (not shown), and measurement is performed by dividing an object scene by obtaining an output for each PD.

  FIG. 3 is a diagram showing a detailed configuration of the photosensor in the photometry circuit 132. As shown in FIG.

  As shown in the figure, the photosensor circuit in the photometry circuit 132 includes a PD 132a, a logarithmic compression amplifier circuit 132b, a voltage amplification circuit 132c, and a switch 132d.

  A plurality of the PDs 132 a are arranged on the light receiving surface of the photometric circuit 132. The PD 132a has a characteristic that generates a current according to the amount of received light. The current generated by the PD 132a is converted into a voltage value corresponding to the amount of current by the logarithmic compression amplifier circuit 132b which is a current-voltage conversion circuit.

  The logarithmic compression amplifier circuit 132b is connected to the corresponding switch 132d, and the voltage converted by the logarithmic compression amplifier circuit 132b is measured by turning on any one of the plurality of switches 132d. The voltage is applied to the voltage amplification circuit 132c. The output voltage Vout from the voltage amplification circuit 132c is input to the A / D conversion circuit 150a in the Bucom 150.

  Here, the Bucom 150 converts an input voltage value into a PD received light amount from a parameter stored in the nonvolatile memory (not shown) and a calculation by the Bucom 150.

  Then, by switching the switch 132d, the PD 132a that measures the amount of light is switched. That is, by switching the switch 132d, the luminance in each area of the divided scene is measured.

  In addition, according to the photosensor circuit configuration in the photometry circuit 132 described with reference to FIG. 3, light is emitted for each PD 132a, but the configuration of the current-voltage conversion circuit is the current generated in each PD 132a. Is stored in a capacitor and voltage conversion is performed, so that it is possible to measure all equally divided regions 201 by one strobe light emission.

  Hereinafter, a photosensor dividing method and a control method provided in the photometry circuit 132, which is one of main features of the camera according to the present embodiment, will be described in detail.

  In the present embodiment, as shown in FIG. 4, the field area is equally divided into seven parts in the vertical direction and seven parts in the horizontal direction to form a total of 49 equally divided areas 201. As a result, the scene is divided into 49 equally divided regions 201.

  Furthermore, a small region 203 having an area equal to or less than half the area of the equally divided region 201 is provided in the central region of each equally divided region 201. Here, FIG. 5A is a halftone image in which the field area thus divided and the field of view in the viewfinder are superimposed.

  Note that FIG. 5B is a halftone image in which an unevenly divided field area and a field of view in the viewfinder are overlapped. FIG. 5C is a halftone image in which the object field area (equal division without providing the small area 203) and the field of view in the finder are overlapped with each other in 100 rows and 10 columns and 10 columns. In the conventional techniques as shown in FIGS. 5B and 5C, details will be described later, but it is not possible to obtain a special effect obtained by the present embodiment.

  FIG. 6 is a diagram showing the definition of the area number set in the equally divided area 201 and the small area number set in the small area 203 for convenience of explanation.

  That is, as shown in the figure, the area number is set by sequentially increasing one by one in the column direction in order from the equally divided area 201 in the first row and the first column. Move to the eye and set by incrementing one by one. In this way, the region numbers are set as shown in FIG. 6 for all equally divided regions 201 extending over 7 rows and 7 columns.

  On the other hand, as the small area number, a value obtained by adding “100” to the area number set in each equally divided area 201 in which the small area 203 is provided is set. For example, the small area number set in the small area 203 provided in the equally divided area 201 of area number 21 is 121 as shown in FIG.

  Hereinafter, various operation controls of the camera according to the present embodiment will be described with reference to the region number and the small region number set as described above.

  FIG. 7 is a flowchart illustrating the operation control by the Bucom 150 of the shooting operation in the camera according to the present embodiment.

  When a release switch that is one of the camera operation SWs 152 is pressed, a distance measuring operation (step S1), a photometric operation (step S2), and an exposure calculation (step S3) are sequentially performed. Detailed operation control in steps S1 to S3 will be described later with reference to FIGS. 9 to 11 showing these subroutines.

  When the exposure calculation process in step S3 is completed, it is determined whether or not the flash light emitting unit 181 is caused to emit light based on the exposure calculation process result (step S4). When step S4 is branched to NO, the process proceeds to step S7 described later.

  On the other hand, when step S4 is branched to YES, a dimming operation is performed (step S5). The details of the dimming calculation will be described later with reference to FIG. 12 showing a dimming calculation subroutine.

  When the light control calculation process in step S5 is completed, an exposure parameter determination process is performed (step S6). The details of the exposure parameter determination will be described later with reference to FIG. 13 showing the exposure parameter determination subroutine. In step S6, the aperture driving amount of the aperture 103, the shutter opening time of the shutter unit 21, the sensitivity of the imaging module 22, and the determination of whether or not to emit strobe light are determined.

  When the processing in step S6 is completed, the quick return mirror 113b is driven to the up position by the mirror driving mechanism 118 in order to expose the imaging module 22 with the parameters determined in step S5 and step S6. (Step S7), a normal exposure operation including shutter travel and aperture control is performed (Step S8).

  After completing the exposure operation in step S8, the quick return mirror 113b is driven to the down position by the mirror driving mechanism 118 (step S9). Simultaneously with the driving of the quick return mirror 113 in step S9, shutter charge, which is a preparation operation for the next exposure operation in the shutter unit 21, is performed (step S10).

  Then, an electrical signal (image signal) acquired by the imaging device (not shown) provided in the imaging module 22 is read and digitized through the imaging device interface circuit 134 at predetermined timings. The digitized image data is temporarily stored in the SDRAM 138 via the image processing controller 140 and then recorded on the recording medium 139 via the communication connector 135 (step S11). Then, the photographing operation is finished.

  Here, FIG. 8 is a diagram showing the position and number of distance measuring points of the AF sensor unit 130a in the field area.

  As shown in FIG. 8, the AF sensor unit 130a is a three-point distance sensor having a distance measuring point in the center of the object field area and the left and right areas. The three distance measuring points are referred to as a left distance measuring point 231L, a center distance measuring point 231C, and a right distance measuring point 231R in order from the left distance measuring point shown in FIG. Note that the subject 233 is located in the center of the object scene. A white portion other than the subject 203 indicates the background, and is located far from the subject with respect to the camera. Although details will be described later, in the example shown in the figure, the central distance measuring point 231C is selected as the distance measuring point.

  Here, as the vicinity of the distance measuring point, in the example shown in FIG. 8, there are equally divided areas 201 of area numbers 17, 18, 19, 24, 25, 26, 31, 32, and 33. Applicable.

  If the left distance measuring point 231L is selected as the distance measuring point, the area numbers near the distance measuring point are area numbers 16, 17, 23, 24, 25, 31, 31, etc. This corresponds to the divided area 201.

  Hereinafter, the operation control of the ranging operation in step S1 will be described with reference to the flowchart shown in FIG. In the present embodiment, the subject that is closest to the camera is used as the subject in the shooting.

  First, the AF sensor unit 130a performs a well-known distance measuring operation that has been performed conventionally (step S21).

  Subsequently, referring to the distance measurement data acquired by the AF sensor unit 130a, is the subject positioned at the closest position to the left distance measurement point 231L among the three distance measurement points? It is determined whether or not (step S22). When step S22 is branched to NO, the process proceeds to step S24 described later.

  On the other hand, when step S22 is branched to YES, the left distance measuring point 231L is selected as the distance measuring point, and the process returns to the flowchart shown in FIG.

  By the way, when step S22 is branched to NO, referring to the distance measurement state data acquired by the AF sensor unit 130a, the object is the right distance measurement among the three distance measurement points. It is determined whether or not the position is closest to the point 231R (step S24).

  When step S24 is branched to YES, the right distance measuring point 231R is selected as a distance measuring point, and the process returns to the flowchart shown in FIG. On the other hand, when step S24 is branched to NO, the central distance measuring point 231C is selected as a distance measuring point, and the process returns to the flowchart shown in FIG.

  Through the series of distance measuring operations described above, it is determined which of the three distance measuring points is closest to the object, and the distance measuring point is selected.

  Hereinafter, the operation control of the photometric operation in step S2 will be described with reference to the flowchart shown in FIG.

  First, the luminance in all equally divided areas 201 is acquired by a well-known photometric process based on the amount of light flux detected by the photosensor (not shown) provided in the photometric circuit 132 (step S31).

  Subsequently, it is determined whether or not the camera is set to a predetermined shooting mode (step S32). The predetermined shooting mode is, for example, a continuous shooting mode or a sports shooting mode in which the shooting speed and the response to the release are important. When this step S32 is branched to YES, the process returns to the flowchart shown in FIG.

  On the other hand, when step S32 is branched to NO, it is determined whether or not the average value of the luminance in the equally divided area near the distance measuring point selected by the distance measuring operation in step S1 is equal to or less than a predetermined value. (Step S33). When step S33 is branched to YES, the process returns to the flowchart shown in FIG.

  When step S33 is branched to NO, the luminance in all the small areas 203 is acquired (step S34). Then, the process returns to the flowchart shown in FIG.

  As can be seen from the series of photometry operations described above, when the average brightness value in the area near the distance measuring point is less than the predetermined value, or when shooting in continuous shooting mode or sport mode where response to shooting speed and release is important Does not acquire the luminance in the small area 203 in order to speed up the photometric processing. On the other hand, when the average value of the luminance in the area near the distance measuring point is equal to or larger than the predetermined value, the luminance in all the small areas 203 is acquired. The reason for performing such operation control is as follows.

  That is, the small region 203 has a smaller light receiving amount in area than the equally divided region 201, and a small amount of current is generated even with the same level of luminance. It is because it is low compared.

  That is, when the average luminance value in the equally divided region 201 near the distance measuring point is a luminance that can ensure a predetermined luminance measurement accuracy, the luminance in the small region 203 is acquired and the predetermined luminance measurement accuracy cannot be ensured. In this case, the luminance measurement accuracy is ensured by acquiring the luminance of only the equally divided area 201. In the camera according to this embodiment, the measurement accuracy of the subject brightness is ensured by such processing.

  Hereinafter, the operation control of the exposure calculation in step S3 will be described with reference to the flowchart shown in FIG. Note that α is a weighting coefficient indicating how much the luminance measurement in each equally divided region 201 contributes to the overall luminance measurement.

  First, in the photometric operation in step S2, it is determined whether or not the luminance in the small region 203 has been acquired (step S41). When this step S41 is branched to NO, the weighting coefficient α = 1 is set, and 1 is assigned to the weighting coefficient α in all equally divided regions (equal divided regions of region numbers 1 to 49). The brightness BV is calculated, and the process returns to the flowchart shown in FIG.

  On the other hand, when step S41 is branched to YES, the following calculation is performed for each equally divided region with respect to all equally divided regions (equal divided regions of region numbers 1 to 49).

  First, it is determined whether or not the equally divided area 201 (for convenience of explanation, the equally divided area of area number m) is an equally divided area near the distance measuring point (step S43). When step S43 is branched to NO, the process proceeds to step S53 described later.

On the other hand, when step S43 is branched to YES, the weighting coefficient α _m of the area number _m is
α _m ← A (Formula 1)
(Step S44).

  Subsequently, the difference between the luminance in the equally divided region 201 and the luminance in the small region 203 is calculated, and it is determined whether or not this luminance difference is larger than a predetermined value (step S45). When step S45 is branched to NO, the process proceeds to step S49 described later.

When step S45 is branched to YES, it is determined whether or not the luminance value in the small region 203 is larger than the luminance value in the equally divided region 201 (step S46). When this step S46 is branched to YES,
α _m ← α _m −C (Formula 2)
(Step S47). That is, the weighting coefficient α _m is subtracted by the C value. On the other hand, when the step S46 is branched to NO,
α _m ← α _m −D (Formula 3)
(Step S48). That is, the weighting coefficient α _m is subtracted by the D value.

Here, C <D. That is, when the luminance difference between the equally divided area 201 and the small area 203 is larger than a predetermined value, the equal divided area 201 of area number m is regarded as an area where the luminance is not stable, and the weighting coefficient α Subtract _m .

Specifically, when the luminance value of the small area 203 is larger than the luminance value of the equally divided area 201 (when the small area 203 is brighter than the equally divided area 201), the area number is larger than that. The value of the weighting coefficient α _m of the m-th equally divided region 201 is increased.

  This is a consideration in view of the fact that, as a characteristic of PD, when a part with various luminances is mixed in one PD, the influence of the brighter part becomes large. That is, when the equally divided area 201 having a larger area than the small area 203 is bright, it is highly possible that the area is affected by extreme luminance such as a point light source. Therefore, when the luminance of the equally divided region 201 is brighter than that of the small region 203, the influence of the region where the luminance is not stabilized is reduced by subtracting the weighting coefficient larger.

By the way, when the step S43 is branched to NO,
α _m ← B (Formula 4)
(Step S53).

Here, A> B. That is, when the equally divided area is not an equally divided area near the distance measuring point, the weighting coefficient α _m is smaller than A as compared with the case where the equally divided area is an equally divided area near the distance measuring point. B value which is a value is set. It should be noted that performing the weighting process according to whether or not the equally divided area is in the vicinity of the distance measuring point in this way is an indispensable process for photographing the subject beautifully.

  After the processing in step S53 is completed, a difference between the luminance value in the equally divided area 201 and the luminance value in the small area 203 is calculated, and it is determined whether or not this luminance difference is larger than a predetermined value (step). S54). When step S54 is branched to NO, the process proceeds to step S49 described later.

On the other hand, when the step S54 is branched to YES,
α _m ← α _m −F (Formula 4)
(Step S55).

  Here, F> D.

As described above, when the equally divided area 201 is not near the distance measuring point, the weighting coefficient α _m of the equally divided area 201 is subtracted, and the luminance difference between the equally divided area 201 and the small area 203 is further reduced. If it is larger than the predetermined value, it is very likely that luminance unevenness has occurred in the equally divided area 201, so that the weighting coefficient α _m of the equally divided area 201 is further subtracted. Note that when the luminance difference between the equally divided area 201 and the small area 203 is smaller than a predetermined value, the further subtraction is not performed.

By the way, after finishing the process in the step S47, the step S48, the step S54, or the step S55, the average brightness BV _m obtained by averaging the brightness of the equally divided area 201 and the small area 203 as follows. Is calculated (step S49).

That is, in step S49, for example, if the area ratio between the equally divided region 201 and the small region 203 is 9: 1,
Average luminance BV _m =
(Equal division area luminance of area number m × 9 + small area luminance of area number (100 + m) × 1) ÷ 10 (Expression 6)
And

  Further, the weighting of luminance in all equally divided regions 201 from region number 1 to region number 49 and the small region 203 corresponding to the equally divided region 201 is added to the numerical value calculated by the above (Expression 6). The average value of the obtained field luminance BV is calculated by the following equation.

  Then, after the processing from step S43 to step S49 is performed in all the regions (region number 1 to region number 49), or after the processing in step S52 is completed, the process returns to the flowchart shown in FIG. .

  Hereinafter, the operation control of the dimming calculation in step S5 will be described with reference to the flowchart shown in FIG.

  First, a well-known flash emission preparation is performed (step S71). Subsequently, the strobe pre-flash is emitted, and the luminance in all equally divided areas 201 is obtained by a well-known photometric process based on the amount of light flux detected by the photosensor (not shown) provided in the photometric circuit 132. (Step S72).

  Then, it is determined whether or not the average luminance value in the equally divided area 201 near the distance measuring point selected by the distance measuring operation in step S1 is equal to or less than a predetermined value (step S73). When this step S73 is branched to YES, the process returns to the flowchart shown in FIG.

  When step S73 is branched to NO, the luminance in all the small areas 203 is acquired (step S74). Then, the process returns to the flowchart shown in FIG.

  Hereinafter, the operation control for determining the exposure parameter in step S6 will be described with reference to the flowchart shown in FIG.

  First, in the case of performing strobe light emission, the light emission amount of strobe main light emission corresponding to the object field luminance BV is calculated based on a preset table (step S81). Subsequently, exposure parameters such as an aperture value, shutter speed, and sensitivity of the imaging module 22 necessary for performing appropriate exposure control on the value of the field luminance BV are calculated (step S82). Note that the calculation method of the aperture value, the shutter speed, the sensitivity of the imaging module, and the like are well known to those skilled in the art, and thus the description thereof is omitted here.

  And after finishing the process in the said step S82, it returns to the flowchart shown in FIG.

  As described above, according to the present embodiment, a photometric device that divides an object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects, and the photometric device Can be provided.

  Specifically, in the photometric device according to the present embodiment and the camera equipped with the photometric device, the object scene is equally divided vertically and horizontally to form an equally divided region 201, and the center in each equally divided region 201 is A small region 203 having an area equal to or less than half the area of the equally divided region 201 is provided in the part.

  With such a configuration, the reliability of photometry in the equally divided area 201 is estimated according to the difference between the brightness calculated in the entire equally divided area 201 and the brightness calculated in the small area 203, and the reliability Is reflected in the photometric calculation. Thereby, according to this embodiment, the following four effects can be mainly acquired in detail.

(Effect 1)
It is possible to provide a photometric device and a camera capable of performing photometry with high accuracy without increasing the number of divisions of the object scene unnecessarily and without increasing the calculation time and the photometric circuit scale.

(Effect 2)
Since the equally divided areas 201 in the object scene are configured to have the same shape, it is possible to obtain an advantage that they are easy to manufacture. Further, since the PD characteristics (parasitic capacitance, dark current, linearity, noise, etc.) in each equally divided region 201 are the same, the correction circuit for improving the photometric accuracy can be minimized.

(Effect 3)
Since the object field area is divided equally and the area generated by the division has a simple shape, data acquired in the past can be used effectively even when the number of divisions is increased in the future. That is, if the object field area is divided into complex shapes such as pentagons and heptagons or different in size and shape, even if the same subject is metered, the difference in shape of the divided areas Since the output varies depending on the number of times, the number of divisions is likely to need to be redesigned. According to this embodiment, this can be prevented.

(Effect 4)
When the subject has low brightness, the brightness is calculated in a relatively large divided area, so that photometric accuracy can be maintained even when the subject has low brightness.

  Hereinafter, the effects of the photometric device and the camera according to the present embodiment will be described in more detail with reference to the drawings.

  FIG. 14A is a halftone image in which the object field area divided into the above-described one embodiment and the field of view in the viewfinder are overlapped. FIG. 14B is a halftone image in which an unevenly divided field region and a field of view in the viewfinder are overlapped. FIG. 14C is a halftone image in which a field area (equal division without providing the small area 203) equally divided into 100 in 10 rows and 10 columns and a field of view in the viewfinder are overlapped. is there.

  Note that the main subject in the halftone image shown in FIGS. 14A to 14C has a composition in which a person is shown in the center of the field of view in the viewfinder and the sun is shown in the upper background.

  Here, the presence of the sun shown in the viewfinder field occupies a small area in the entire viewfinder field, but due to its intense brightness, the influence on the brightness of the entire field of view becomes large. As a result, in the determination of luminance, it is determined that the scene is brighter than actual, and the subject tends to be under.

However, according to the present embodiment, as shown in FIG. 14A, in the equally divided area 201 having the area numbers 3 and 4, a large luminance difference is generated between the equally divided area 201 and the small area 203. The photometric weighting coefficient α _m in the equally divided areas 201 of area numbers 3 and 4 is subtracted as described above.

In addition, the photometric weighting coefficient α _m in the equally divided areas No. 25, No. 32, No. 39, No. 45, No. 46, and No. 47 having a small luminance difference between the equally divided area 201 and the small area 203 is relatively growing. According to the camera of this embodiment, the subject is appropriately photographed by the photometric weighting calculation in each equally divided region 201.

  In the example shown in FIG. 14B, the scene division is determined by an empirical rule, and in consideration of the fact that an important subject often comes to the center, the periphery is divided into a large area, and the center is It is divided into many small areas. If such a division is performed, it is determined that only the divided area where the sun is shown is bright, and if only this divided area is excluded from the photometric calculation, the influence of sunlight can be reduced. However, the division as in the example shown in FIG. 14B cannot obtain the effects described in (Effect 2) and (Effect 3) described above.

In the example shown in FIG. 14C, since the divided area in the vicinity where the sun is shown is very bright compared to the other divided areas, it is possible to determine to subtract these weights. However, the number of weighting coefficients alpha _m required becomes twice the required number of weighting coefficients alpha _m in the present embodiment. That is, an increase in the amount of calculation becomes a problem.

  FIG. 15A is a halftone image in which the object region divided into the above-described one embodiment and the field of view in the finder (night view; the same applies to FIGS. 15B and 15C) are overlapped. FIG. 15B is a halftone image in which an unevenly divided field region and a field of view in the viewfinder are overlapped. FIG. 15C is a halftone image in which an object field area (equal division without providing the small area) divided into 100 equal rows and 10 columns and a visual field in the viewfinder are overlapped.

  In the example shown in FIGS. 15A to 15C, the presence of the illuminating lamp in the upper right portion occupies a small area in the entire viewfinder field, but due to its brightness, the influence on the luminance of the entire object field is large. As a result, in the determination of luminance, it is determined that the scene is brighter than actual, and the subject tends to be under. Further, in night scene shooting as in the examples shown in FIGS. 15A to 15C, the amount of light received by the PD decreases, making it difficult to maintain measurement accuracy in photometry.

However, according to the present embodiment, as shown in FIG. 15A, in the equally divided areas 201 of the area numbers 13, 14, and 23, the equally divided areas 201 and the corresponding small areas 203 Since a large luminance difference occurs between them, the photometric weighting coefficient α _m in the equally divided areas 201 of the area numbers 13, 14, and 23 is subtracted. Thereby, the bad influence by the said illumination lamp can be suppressed, and appropriate exposure can be obtained.

  In the example shown in FIG. 15B, the scene division is determined by an empirical rule, and in consideration of the fact that an important subject often comes to the center, the periphery is divided into a large area, and the center is It is divided into many small areas.

  However, if the object scene has a low luminance as in a night view, the amount of light received in one divided area becomes small, and it becomes difficult to maintain photometric accuracy. As a result, there arises a problem that it is impossible to obtain the accuracy of photometric accuracy at the center of the object scene, which is important. In order to solve such problems, the correction circuit and the correction calculation tend to be complicated.

  Further, in the case of beautifully photographing a building on the right side of the object scene, the object field division as shown in FIG. 15B has a demerit that the number of object scene divisions corresponding to the building is small and the amount of information is small. .

  In the example shown in FIG. 15C, the size of the equally divided area of the object scene is smaller than the size of the equally divided area 201 in the present embodiment, so that it is expected that the photometric accuracy at low luminance will decrease. However, since the number of divisions itself is larger than the number of divisions in the present embodiment, the amount of information increases.

In the example shown in FIG. 15C, the equally divided areas that require specific processing for calculation are equally divided areas corresponding to two illumination lamps in the right and left parts and a building in the right part. However, the required number of weighting coefficients α _m is 100, which is twice the weighting coefficient in the present embodiment. That is, an increase in the amount of calculation becomes a problem.

  As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to embodiment mentioned above, Of course, a various deformation | transformation and application are possible within the range of the summary of this invention. is there.

[First Modification]
2. Description of the Related Art Conventionally, a photographing mode is generally known in which the luminance of only the center portion in the object scene is measured and the exposure is determined based on the luminance value. This shooting mode is generally referred to as spot metering mode, and the user measures the brightness of only the subject desired by the user by causing the camera to perform metering of the center only in the center of the subject field. can do.

  Then, by applying this spot photometry mode to the photometry device according to the first embodiment and the camera equipped with the photometry device, for example, a small region number 125 corresponding to the equally divided region 201 of region number 25 is used. Using the luminance value in the region 203, spot photometry with a higher spot property than the conventional one can be realized.

[Second Modification]
In the first embodiment, in the photometric operation process, as described with reference to the flowchart shown in FIG. 10, is the average luminance value in the equally divided area near the distance measuring point equal to or less than a predetermined value? If it is not determined to be less than or equal to the predetermined value, the luminance in all the small areas 203 has been acquired.

  However, as in the flowchart shown in FIG. 16, the brightness in all equally divided areas 201 is acquired (step S91), and for each equally divided area 201, the brightness of the equally divided area 201 is equal to or lower than a predetermined brightness. Whether or not (step S92), and when this step S83 branches to NO (when the luminance of the equally divided region 201 is equal to or higher than the predetermined luminance), the luminance of the small region 203 is acquired (step S93). Of course.

[Third Modification]
In the case of acquiring the luminance in the equally divided area 201, the light is received by an area of 1/49 of the light receiving area in the photosensor (not shown) (only the equally divided area 201), and the luminance in the small area 203 is acquired. Alternatively, the PD in the part other than the small region 203 and the current-voltage conversion circuit may be disconnected.

The equally divided area 201 and the small area 203 are completely independent divided areas, and the equally divided area 201 may be configured as a donut-shaped area excluding the small area 203 [fourth modification].
As shown in FIG. 18A and FIG. 18B, the division pattern of the scene area is divided into the division pattern of the scene area peculiar to the one embodiment and the division pattern of the scene area conventionally performed (hereinafter referred to as the pattern of division of the scene area). Of course, it may be a divided pattern having a configuration in combination with a conventional pattern division region.

  In FIG. 18A and FIG. 18B, the hatched area is a conventional pattern division area 301. On the other hand, the area shown in white is an area formed by the divided pattern of the object field area unique to the above-described embodiment, which is composed of the equally divided area 201 and the small area 203.

  Here, in the example shown in FIG. 18A, the peripheral part in the object scene area is configured by the conventional pattern divided area 301, and the central part in the object scene area is the equally divided area 201 and the small area peculiar to the one embodiment. 203.

  On the other hand, in the example shown in FIG. 18B, the central part in the object scene area is configured by the conventional pattern divided area 301, and the peripheral part in the object scene area is the equally divided area 201 and the small area 203 peculiar to the one embodiment. It is composed of.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

(Appendix)
The invention having the following configuration can be extracted from the specific embodiment.

(1) Multi-division photometry means for measuring light by dividing an object scene into a plurality of areas;
An arithmetic means for calculating a luminance value of the object scene based on an output of the multi-segment photometry means;
Comprising
The multi-division photometry means has an equally divided area corresponding to a plurality of photometric areas obtained by dividing the object field equally in the vertical direction and the horizontal direction, and has an area smaller than the equally divided area and the equally divided area A small area provided at the center of the light receiving surface, and output a photometric value in the equally divided area and a photometric value in the small area,
The calculation means is configured to calculate the equal division area based on a difference between a photometric value in the equal division area and a photometry value in the small area corresponding to the equal division area, and a position of the equal division area in the object scene. A photometric device for calculating a luminance value of the object scene by weighting the photometric value in and the photometric value in the small area.

(Corresponding embodiment)
The embodiment related to the photometric device described in (1) corresponds to the one embodiment.

(Function and effect)
According to the photometric device described in (1), it is possible to provide a photometric device that divides the object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects. it can.

(2) When the photometric value in the equally divided area is equal to or less than a predetermined value, the calculation means weights the photometric value in the small area corresponding to the equally divided area instead of the photometric value in the equally divided area. The photometric device according to (1), wherein the photometric device performs calculation.

(Corresponding embodiment)
The embodiment related to the photometric device described in (2) corresponds to the one embodiment.

(Function and effect)
According to the photometric device described in (2), it is possible to provide a photometric device that divides the object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects. it can.

  (3) a mode for calculating a luminance value by using only the photometric value of the equally divided area in the central part which is an equally divided area of the light receiving surface in the multi-divided photometric means corresponding to the central part in the object field, the central part, etc. And a mode for calculating a luminance value using only a photometric value of a small area in the divided area, (1) or (2).

(Corresponding embodiment)
The embodiment related to the photometric device described in (3) corresponds to the one embodiment.

(Function and effect)
According to the photometric device described in (3), it is possible to provide a photometric device that divides an object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects. it can.

  (4) subject position detecting means, wherein the computing means is an equally divided area corresponding to the output of photometry in all equally divided areas in the multi-division metering means and the subject position of the detection result by the subject position detecting means The photometric device according to any one of (1) to (3), wherein the luminance value of the object scene is calculated using only the photometric output in a small area corresponding to.

(Corresponding embodiment)
The embodiment relating to the photometric device described in (4) corresponds to the one embodiment.

(Function and effect)
According to the photometric device described in (4), it is possible to provide a photometric device that divides the object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects. it can.

  (5) The photometric device according to any one of (1) to (4), wherein the equally divided area is an area including the small area.

(Corresponding embodiment)
The embodiment relating to the photometric device described in (5) corresponds to the one embodiment.

(Function and effect)
According to the photometric device described in (5), it is possible to provide a photometric device that divides the object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects. it can.

  (6) The photometric device according to any one of (1) to (5), wherein the equally divided area is an area excluding the small area.

(Corresponding embodiment)
The embodiment related to the photometric device described in (6) corresponds to the one embodiment.

(Function and effect)
According to the photometric device described in (6), it is possible to provide a photometric device that divides the object field into efficient photometric distributions and improves photometric accuracy and photometric stability for various subjects. it can.

(7) A photometric device comprising: a multi-division photometry unit that divides a subject field into a plurality of areas and performs photometry; and an arithmetic unit that calculates a luminance value of the scene based on an output of the multi-division photometry unit When,
An optical system for guiding the luminous flux from the subject to the photometric device;
An exposure control unit that performs exposure control based on a luminance value of the object scene output from the photometric device;
Comprising
The multi-division photometry means has an equally divided area corresponding to a plurality of photometric areas obtained by dividing the object field equally in the vertical direction and the horizontal direction, and has an area smaller than the equally divided area and the equally divided area A small area provided at the center of the light receiving surface, and output a photometric value in the equally divided area and a photometric value in the small area,
The calculation means is configured to calculate the equal division area based on a difference between a photometric value in the equal division area and a photometry value in the small area corresponding to the equal division area, and a position of the equal division area in the object scene. The camera is characterized in that the luminance value of the object scene is calculated by weighting the photometric value in and the photometric value in the small area.

(Corresponding embodiment)
The embodiment related to the camera described in (7) corresponds to the one embodiment.

(Function and effect)
According to the camera described in (7), it is possible to provide a camera in which the object scene is divided into efficient photometric distributions to improve photometric accuracy and photometric stability for various subjects.

(8) When the photometric value in the equally divided area is equal to or less than a predetermined value, the calculation unit weights the photometric value in the small area corresponding to the equally divided area instead of the photometric value in the equally divided area. (7) The camera according to (7), wherein the calculation is performed.

(Corresponding embodiment)
The embodiment related to the camera described in (8) corresponds to the one embodiment.

(Function and effect)
According to the camera described in (8), it is possible to provide a camera in which the object scene is divided into efficient photometric distributions to improve photometric accuracy and photometric stability for various subjects.

  (9) a mode for calculating a luminance value using only the photometric value of the equally divided area of the central part which is an equally divided area of the light receiving surface in the multi-divided photometric means corresponding to the central part of the object field, the central part, etc. The camera according to (7) or (8), further comprising: a mode for calculating a luminance value using only a photometric value of a small area in the divided area.

(Corresponding embodiment)
The embodiment related to the camera described in (9) corresponds to the one embodiment.

(Function and effect)
According to the camera described in (9), it is possible to provide a camera in which the object scene is divided into efficient photometric distributions to improve photometric accuracy and photometric stability for various subjects.

  (10) Subject position detecting means, wherein the computing means is an equally divided area corresponding to the output of photometry in all equally divided areas in the multi-division metering means and the subject position of the detection result by the subject position detecting means. The camera according to any one of (7) to (9), wherein a luminance value of the object scene is calculated using only a photometric output in a small area corresponding to.

(Corresponding embodiment)
The embodiment related to the camera described in (10) corresponds to the one embodiment.

(Function and effect)
According to the camera described in (10), it is possible to provide a camera in which the object scene is divided into efficient photometric distributions to improve photometric accuracy and photometric stability for various subjects.

  (11) The camera according to any one of (7) to (10), wherein the equally divided area is an area including the small area.

(Corresponding embodiment)
The embodiment related to the camera described in (11) corresponds to the one embodiment.

(Function and effect)
According to the camera described in (11), it is possible to provide a camera in which the object scene is divided into efficient photometric distributions to improve photometric accuracy and photometric stability for various subjects.

  (12) The camera according to any one of (7) to (11), wherein the equally divided area is an area excluding the small area.

(Corresponding embodiment)
The embodiment related to the camera described in (12) corresponds to the one embodiment.

(Function and effect)
According to the camera described in (12), it is possible to provide a camera in which the object scene is divided into efficient photometric distributions to improve photometric accuracy and photometric stability for various subjects.

The figure which shows an example of the system configuration | structure of the camera which concerns on one Embodiment of this invention. (A), (B) is a figure which shows typically the optical system of the camera which concerns on one Embodiment of this invention. The figure which shows the detailed structure of the photosensor in a photometry circuit. The figure which shows the example of a division | segmentation of the object scene in one Embodiment of this invention. A halftone image with the divided field of view and the field of view in the viewfinder superimposed. A halftone image in which an unevenly divided field area and the field of view in the viewfinder are superimposed. A halftone image in which an object field area (equal division without providing a small area) divided by 100 in 10 rows and 10 columns and a visual field in the viewfinder are overlapped. The figure which shows the definition of the area number set to an equally divided area, and the small area number set to the said small area 203. The figure which shows the flowchart which shows the operation control by Bucom of imaging | photography operation | movement in the camera which concerns on one Embodiment of this invention. The figure which shows the position and the number in a field area of the ranging point which AF sensor unit has. The figure which shows the flowchart of the operation control of ranging operation. The figure which shows the flowchart of operation control of photometry operation | movement. The figure which shows the flowchart of the operation control of exposure calculation. The figure which shows the flowchart of operation control of a light control calculation. The figure which shows the flowchart of the operation control of exposure parameter determination. FIG. 5 is a halftone image in which a field area divided according to an embodiment of the present invention is overlapped with a field of view in a viewfinder. A halftone image in which an unevenly divided field area and the field of view in the viewfinder are superimposed. A halftone image in which a field area divided by 100 in 10 rows and 10 columns and a field of view in a viewfinder are overlapped. FIG. 5 is a halftone image in which a field area divided according to an embodiment of the present invention is overlapped with a field of view in a viewfinder. A halftone image in which an unevenly divided field area and the field of view in the viewfinder are superimposed. A halftone image in which a field area divided by 100 in 10 rows and 10 columns and a field of view in a viewfinder are overlapped. The figure which shows the flowchart of operation control of the photometry operation | movement in a 2nd modification. (A) thru | or (C) is a figure which shows the object field division | segmentation concept in the photometry performed by dividing an object field into a some area | region. The figure which shows the object field area | region of the structure which combined the division | segmentation pattern of the object field area | region peculiar to one Embodiment of this invention, and the division | segmentation pattern of the object field area | region conventionally performed. The figure which shows the object field area | region of the structure which combined the division | segmentation pattern of the object field area | region peculiar to one Embodiment of this invention, and the division | segmentation pattern of the object field area | region conventionally performed.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 21 ... Shutter unit, 22 ... Imaging module, 100 ... Body unit, 102 ... Lens drive mechanism, 104 ... Aperture drive mechanism, 105 ... Microcomputer for lens control, 106 ... Communication connector, 112 ... Lens unit, 112a, 112b ... Photographing Lens 113b ... Quick return mirror 113a ... Penta prism 113d ... Sub mirror 113c ... Eyepiece lens 113b ... Quick return 113f ... Focusing screen 113 ... Quick return mirror 118 ... Mirror drive mechanism 130b ... AF sensor drive circuit , 130a, AF sensor unit, 132, photometry circuit, 132a, PD, 132b, logarithmic compression amplifier circuit, 132c, voltage amplification circuit, 132d, switch, 134 Image sensor interface circuit, 135 ... Communication connector, 136 ... Liquid crystal monitor, 138 ... SDRAM, 139 ... Recording medium, 140 ... Image processing controller, 148 ... Shutter drive control circuit, 150 ... Microcomputer for body control, 150a ... A / D Conversion circuit, 152 ... Camera operation switch, 153 ... Power supply circuit, 154 ... Battery, 157 ... LCD for operation display, 180 ... Strobe unit, 181 ... Flash emission part, 231L ... Left distance measuring point, 231C ... Center distance measuring point, 231R: Right distance measuring point, 182 ... Light emission control circuit, 183 ... Strobe control microcomputer, 233 ... Subject, 184 ... Battery, 185 ... Strobe communication connector, 201 ... Equally divided area, 203 ... Small area, 301 ... Conventional pattern Split area.

Claims (6)

Multi-division photometry means for dividing the subject field into a plurality of areas for photometry,
An arithmetic means for calculating a luminance value of the object scene based on an output of the multi-segment photometry means;
Comprising
The multi-division photometry means has an equally divided area corresponding to a plurality of photometric areas obtained by dividing the object field equally in the vertical direction and the horizontal direction, and has an area smaller than the equally divided area and the equally divided area And a photometric value in the equally divided area and a photometric value in the small area are output on the light receiving surface.   The arithmetic means calculates the photometric value in the equally divided area and the photometric value in the small area based on the difference between the photometric value in the equally divided area and the photometric value in the small area corresponding to the equally divided area. The photometric device according to claim 1, wherein weighting is performed to calculate a luminance value of the object scene.   3. The photometric device according to claim 2, wherein the calculation unit calculates the luminance value of the object scene by changing the weighting based on a position of the equally divided region in the object scene. . A photometric device comprising: a multi-division photometry unit that divides the object field into a plurality of areas and performs photometry; and an arithmetic unit that calculates a luminance value of the object field based on an output of the multi-division photometry unit;
An optical system for guiding the luminous flux from the subject to the photometric device;
An exposure control unit that performs exposure control based on a luminance value output from the photometric device;
Comprising
The multi-division photometry means has an equally divided area corresponding to a plurality of photometric areas obtained by dividing the object field equally in the vertical direction and the horizontal direction, and has an area smaller than the equally divided area and the equally divided area And a small area provided at the center of the light receiving surface, and outputs a photometric value in the equally divided area and a photometric value in the small area.   The arithmetic means calculates the photometric value in the equally divided area and the photometric value in the small area based on the difference between the photometric value in the equally divided area and the photometric value in the small area corresponding to the equally divided area. The camera according to claim 4, wherein weighting is performed to calculate a luminance value of the object scene.   The camera according to claim 5, wherein the computing unit calculates the luminance value of the object scene by changing the weighting based on the position of the equally divided region in the object scene.

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