JP2008185821A - Photometric device and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photometric device capable of appropriately obtaining information by using an accumulation type photometric sensor. <P>SOLUTION: The photometric device includes the accumulation type photometric sensor 19, and accumulation control means 23 and 24 performing first control to control accumulation of the photometric sensor 19 based on the maximum value of output obtained by the photometric sensor 19, and second control to control accumulation of the photometric sensor 19 based on an average output value by the photometric sensor 19. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photometric device and an imaging apparatus having the photometric device.

  When using a storage-type photometric element and dividing the light-receiving surface of the element into a plurality of areas for photometry, the photometric element does not saturate and takes a value close to the saturation level. Is known to control the accumulation (see Patent Document 1).

Japanese Patent No. 3601146

  If you use the same storage type photometric element and try to obtain the color information of the object to be measured based on the output obtained by receiving the light beam through the color filter, if you perform storage control based on the maximum output value, There is a part where the output decreases in preparation, and appropriate color information cannot be obtained.

(1) A photometric device according to the present invention is based on an accumulation-type photometric sensor, first control for accumulating and controlling the photometric sensor based on the maximum output value obtained by the photometric sensor, and an average output value from the photometric sensor. And accumulation control means for performing second control for accumulation control of the photometric sensor.
(2) In the photometric device according to claim 1, it is preferable that the accumulation control means selectively switches between the first control and the second control.
(3) In the photometry device according to claim 2, it is preferable that the accumulation control means performs the first control before the second control.
(4) In the photometric device according to any one of claims 1 to 3, the accumulation control means is configured so that the maximum value of the output does not exceed the saturation output level of the photometric sensor during the first control. The accumulation time and gain are determined, and during the second control, the accumulation time and gain of the photometric sensor are set such that the average output value of the photometric sensor falls within a predetermined range based on the accumulation time and gain during the first control. Is preferably determined.
(5) In the photometric device according to claim 4, it is preferable that the accumulation control means does not perform the second control when the accumulation time of the photometric sensor during the first control is longer than a predetermined time.
(6) In the photometric device according to claim 4, the photometric sensor may be configured to divide the light receiving surface of the light beam into a plurality of regions and obtain an output for each region. In this case, the accumulation control means preferably does not perform the second control when the difference between the outputs in the plurality of areas is equal to or less than a predetermined value during the first control.
(7) The photometric device according to claim 6 may further include a color filter. In this case, the output difference between the areas of the photometric sensor is preferably obtained from the luminance value of the light beam received by the photometric sensor through the color filter or the output value of the predetermined color.
(8) An image pickup apparatus according to the present invention controls exposure using luminance information based on the photometric device according to any one of claims 1 to 4, a color filter, and an output of a photometric sensor obtained by the first control. And a photographing control means for performing focus detection control using luminance information or color information based on the output of the photometric sensor obtained by the second control with respect to the light flux through the color filter.
(9) An imaging device according to the present invention is obtained by the second control with respect to the photometric device according to any one of claims 1 to 4, an imaging unit, a color filter, and a light beam that passes through the color filter. And analyzing means for analyzing a scene photographed by the photographing means using color information and luminance information based on the output of the photometric sensor.
(10) An image pickup apparatus according to the present invention provides an output of a photometric sensor according to claim 5 or 6, an imaging means, a color filter, and a photometric sensor obtained by a first control with respect to a light beam passing through the color filter. And analyzing means for analyzing a scene photographed by the photographing means using the color information and luminance information based thereon.

  According to the present invention, information can be appropriately obtained using a storage-type photometric sensor.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a main configuration of an electronic camera equipped with a photometric device according to an embodiment of the present invention. In FIG. 1, a photographic lens 50 configured to be detachable from the camera body 10 is attached.

  Light from the subject enters the camera body 10 through the lens optical system 51 and the diaphragm 52 of the photographing lens 50. The subject light incident on the camera body 10 is guided to the upper finder by a quick return mirror (hereinafter referred to as a main mirror) 11 positioned as indicated by a broken line before being released, and forms an image on the diffusion screen 14. A part of the subject light incident on the camera body 10 is reflected downward by the sub mirror 21 and also enters the distance measuring element 22. The distance measuring element 22 is a known pupil division type used at the time of focus detection (AF processing) for detecting the focus adjustment state by the photographing lens 50.

  The subject light imaged on the diffusing screen 14 further enters the pentaprism 15 via the condenser lens 20. The pentaprism 15 guides the incident subject light to the eyepiece 16, and also guides part of it to the photometric optical system 17. The light incident on the photometric optical system 17 forms a subject image on the photometric sensor 19 via the photometric lens 18. The photometric sensor 19 includes a CCD image sensor provided with a plurality of photoelectric conversion elements corresponding to pixels. The photometric sensor 19 outputs a photoelectric conversion signal for photometric processing corresponding to the brightness of the subject image.

  After the release, the main mirror 11 rotates to the position indicated by the solid line, and the subject light is guided to the image sensor 13 via the shutter 12 to form a subject image on the imaging surface. The image sensor 13 is configured by a CCD image sensor or the like provided with a plurality of photoelectric conversion elements corresponding to pixels. The image sensor 13 captures a subject image formed on the imaging surface, and outputs a photoelectric conversion signal for photographing corresponding to the brightness of the subject image.

  The photographing operation of the electronic camera is controlled by the photographing control circuit 25. The photometric sensor 19 is controlled by the photometric circuit 24 and the accumulation control circuit 23 that have received an instruction from the imaging control circuit 25 during photometric processing described later. Note that the accumulation control circuit 23, the photometry circuit 24, and the photographing control circuit 25 are actually disposed inside the camera body 10.

  FIG. 2 is a flowchart for explaining the flow of the photographing process performed by the photographing control circuit 25 described above. In step S11, the imaging control circuit 25 determines whether or not a release button (not shown) has been pressed halfway. The imaging control circuit 25 makes an affirmative determination in step S11 when the half-press operation is performed, and proceeds to step S12. If the half-press operation is not performed, the imaging control circuit 25 makes a negative determination in step S11 and proceeds to step S21.

  In step S12, the imaging control circuit 25 sends an instruction to a sensor control microcomputer which will be described later, performs photometry processing, and proceeds to step S13. Details of the photometric processing will be described later. In step S13, the imaging control circuit 25 performs AF processing using the detection signal from the distance measuring element 22, and proceeds to step S14. In step S14, the imaging control circuit 25 determines whether or not a release button (not shown) has been fully pressed. The imaging control circuit 25 makes an affirmative determination in step S14 when the full-press operation is performed, and proceeds to step S15. If the full-press operation is not performed, the imaging control circuit 25 makes a negative determination in step S14 and returns to step S11.

  In step S15, the imaging control circuit 25 sends an instruction to a sequence control device (not shown), starts up driving of the main mirror 11, and proceeds to step S16. In step S16, the imaging control circuit 25 initializes the image sensor 13 and proceeds to step S17. In step S <b> 17, the imaging control circuit 25 causes the imaging device 13 to accumulate imaging charges for a predetermined time. Note that the diaphragm 52 and the running curtain of the shutter 12 are driven by a sequence control device (not shown) so that the control exposure calculated by the exposure calculation using the photometric processing result is obtained. The imaging control circuit 25 instructs to sweep out the charges accumulated in the image sensor 13, and proceeds to step S18.

  In step S18, the imaging control circuit 25 sends an instruction to a sequence control device (not shown) to start down driving of the main mirror 11, and proceeds to step S19. In step S19, the imaging control circuit 25 performs predetermined image processing on the charge signal (photoelectric conversion signal) constituting the image, and then proceeds to step S20. In step S20, the imaging control circuit 25 records the image-processed data on a recording medium (not shown), and ends the imaging process shown in FIG.

  In step S21, which proceeds with a negative determination in step S11, the imaging control circuit 25 determines whether the time is up. The imaging control circuit 25 makes an affirmative determination in step S21 when a predetermined time has elapsed in the non-operation state, and ends the process of FIG. On the other hand, if the predetermined time has not elapsed, the imaging control circuit 25 makes a negative determination in step S21 and returns to step S11.

Hereinafter, the photometric process will be described in more detail.
<Configuration of photometric sensor>
FIG. 3 is a diagram for explaining the photometric sensor 19. The photometric sensor 19 has an optical black portion 19b and an effective pixel portion 19a. The pixels included in the optical black portion 19b are shielded from light and output a signal serving as a reference for sensor output. The pixels included in the effective pixel portion 19a output a photoelectric conversion signal received through the color filter 19c (FIG. 1). In this example, a pixel having the R, G, and B color filters 19c is configured as one pixel.

  The photometry sensor 19 receives a driving clock signal, a signal for controlling the charge accumulation time, and a gain control signal for controlling the amplification gain from the sensor control microcomputer corresponding to the accumulation control circuit 23 and the photometry circuit 24 of FIG. The The photometric sensor 19 synchronizes the accumulated charge signal (photometric signal Vout) with the A / D timing signal and outputs the A / D timing signal to the sensor control microcomputer. The photometry circuit 24 obtains a signal value for each pixel by performing A / D conversion (analog signal → digital signal conversion) of the photometry signal Vout.

<Division of area>
FIG. 4 is a diagram for explaining area division of the photometric sensor 19. In the present embodiment, an example in which the effective pixel portion 19a is divided into 15 regions will be described. The photometry circuit 24 calculates the luminance obtained from the photometry signal Vout in the divided area or the average value of the signal values of the G pixels included in the area. In general, in the case of shooting under backlighting or shooting including a high-luminance subject, the average brightness value (or the average value of the G pixel signal) varies greatly between the divided areas. Accordingly, when the average value of the luminance or G signal calculated for each region is compared between the divided regions, if there is a difference of a predetermined value or more, it is determined that the shooting is performed under backlighting or shooting including a subject with high luminance. it can.

<Dynamic range of photometric sensor>
FIG. 5A is a diagram for explaining the photometric range of the photometric device. The electronic camera of the present embodiment has a range of EV0 to EV20 as a photometric range. FIG. 5B is a diagram illustrating the dynamic range of the photometric sensor 19. When a storage type photometric sensor such as a CCD sensor is used, its dynamic range depends on the accuracy (ie, bit length) of A / D conversion. For example, the dynamic range in the case of A / D conversion with a 10-bit length is about 7 stages in EV value as shown in FIG. In this case, since it is difficult to appropriately obtain luminance information for the entire range of EV1 to EV20, the photometric range is switched according to information to be acquired from the photometric sensor 19. The photometric range is switched by changing at least one of the above-described charge accumulation time and amplification gain.

  6A to 6D are diagrams for explaining information obtained from the photometric sensor 19 in a shooting scene including a high-luminance subject. FIG. 6A is a diagram illustrating an image (luminance information) obtained from the photometric sensor 19 that has been “photometric sensor controlled” so as to determine the photometric range based on the maximum value of the photometric signal Vout. Although the pixel signal value corresponding to the sun located behind the person is set close to the maximum brightness target level (the maximum brightness target level is lower than the saturation level), the pixel signal in the solar region is not saturated, The pixel signals in other areas including are smaller than the average luminance level (too dark).

  FIG. 6B is a diagram illustrating an image (luminance information) obtained from the photometric sensor 19 that has been “scene-analyzed sensor controlled” so as to determine the photometric range based on the average value of the photometric signal Vout. Since the photometric range is determined so that the average pixel signal value in the screen approaches the average luminance target level, the pixel signals in the sun region are saturated, but the pixel signals in other regions including a person approach the average luminance level.

  FIG. 6C is a diagram exemplifying an image (color information) obtained from the photometric sensor 19 subjected to the “photometric sensor control”. Although the sun area has color information, other areas including the person lack color information and become monochrome (too dark). FIG. 6D is a diagram exemplifying an image (color information) obtained from the photometry sensor 19 subjected to the “scene analysis sensor control”. Although the sun region is white, color information can be obtained from other regions including people.

  Thus, “photometric sensor control” is suitable for obtaining luminance information (luminance or G signal value) from the photometric sensor 19, and “scene analysis control” is suitable for obtaining color information from the photometric sensor 19. .

(Photometric processing)
The sensor control microcomputers 23 and 24 appropriately acquire luminance information and color information by switching the photometric range of the photometric sensor 19. FIG. 7 is a flowchart for explaining the flow of photometric processing performed by the sensor control microcomputers 23 and 24. The photometric process according to FIG. 7 corresponds to step S12 in FIG. In step S1 of FIG. 7, the sensor control microcomputers 23 and 24 cause the photometric sensor 19 to perform charge accumulation by “photometric sensor control”, and then proceed to step S2.

  In step S2, the sensor control microcomputers 23 and 24 perform a photometric calculation using the signal value after A / D conversion to calculate a luminance value, and proceed to step S3. The photometric calculation result is used for exposure calculation by the imaging control circuit 25. In step S3, the sensor control microcomputers 23 and 24 cause the photometric sensor 19 to perform charge accumulation by “scene analysis sensor control”, and then the process proceeds to step S4. However, if it is determined that the scene analysis sensor control is not performed by the determination process described later, step S3 is skipped. In step S4, the sensor control microcomputers 23 and 24 perform a scene analysis calculation and finish the process shown in FIG.

  The scene analysis calculation uses the color information obtained from the photometric sensor 19, for example, by determining the blue part as the background or the skin color part as the main subject, and thereby, among the plurality of regions divided into the regions. An area in which the main subject exists is determined. The main subject area determined in this way is used when determining an area for detecting focus adjustment information in AF processing.

(Photometric sensor control processing)
FIG. 8 is a flowchart for explaining the flow of photometric sensor control processing performed by the sensor control microcomputers 23 and 24. This flowchart explains step S1 and step S3 in detail. In step S101 of FIG. 8, the sensor control microcomputers 23 and 24 determine whether or not the power is turned on. The sensor control microcomputers 23 and 24 make an affirmative decision in step S101 when the process is the first process after the power is turned on, and proceed to step S102. The process proceeds to S103.

  In step S102, the sensor control microcomputers 23 and 24 initialize the photometric sensor 19, and proceed to step S103. In step S103, the sensor control microcomputers 23 and 24 determine whether or not the execution flag is on. If the execution flag is on, the sensor control microcomputers 23 and 24 make a positive determination in step S103 and proceed to step S113. If the execution flag is off, the sensor control microcomputer 23 and 24 proceeds to step S104. The execution flag is set in a “scene analysis control execution determination” process described later.

  In step S104, the sensor control microcomputers 23 and 24 increment the count value by 1 and proceed to step S105. This counter counts the number of accumulations of the photometric sensor 19 by “photometric sensor control”. In step S105, the sensor control microcomputers 23 and 24 cause the photometric sensor 19 to accumulate charges by “photometric sensor control”, and the process proceeds to step S106. Note that a standard time and a standard gain determined in advance are used for the first charge accumulation time and amplification gain, respectively. These values are stored in a nonvolatile memory (not shown) in the sensor control microcomputers 23 and 24. In step S106, the sensor control microcomputers 23 and 24 read the photometric signal Vout from the photometric sensor 19, and proceed to step S107.

  In step S107, the sensor control microcomputers 23 and 24 determine the data validity for the signal value after A / D conversion, and proceed to step S108. The sensor control microcomputers 23 and 24 (1) If the data indicates output saturation due to an abnormality of the photometric sensor 19, (2) If the data exceeds the maximum allowable luminance, (3) If the data exceeds the allowable minimum luminance (the influence of noise) If it falls under any of the cases where the low luminance state is unacceptable), “no data validity” is determined. On the other hand, the sensor control microcomputers 23 and 24 determine “data valid” if none of the above (1) to (3) is satisfied.

  In step S108, the sensor control microcomputers 23 and 24 calculate the next charge accumulation time and the next amplification gain, and proceed to step S109. As illustrated in FIG. 6A, the sensor control microcomputers 23 and 24 accumulate the data so that the maximum value of the data read in step S106 approaches the maximum luminance target level (the maximum luminance target level is lower than the saturation level). And determining the amplification gain.

  In step S109, the sensor control microcomputers 23 and 24 perform redo determination and proceed to step S110. The sensor control microcomputers 23 and 24 determine “redo” when “no data validity” is determined or the count value is less than a predetermined value. On the other hand, the sensor control microcomputers 23 and 24 do not determine “redo” when “data valid” is determined or the count value exceeds a predetermined value.

  In step S110, if the sensor control microcomputers 23 and 24 have determined redo, the sensor control microcomputers 23 and 24 make a positive determination in step S110 and return to step S104. In this case, charge accumulation by “photometric sensor control” is repeated. If the sensor control microcomputers 23 and 24 have not determined redo, the sensor control microcomputers 23 and 24 make a negative determination in step S110 and proceed to step S111. When the process proceeds to step S111, the counter for counting the number of accumulations is reset.

  In step S111, the sensor control microcomputers 23 and 24 calculate correction coefficients necessary for the photometric calculation, and the process proceeds to step S112. In step S112, the sensor control microcomputers 23 and 24 perform "scene analysis control execution determination" and return to step S103. Details of the scene analysis control execution determination will be described later.

  In step S113, which proceeds after making an affirmative decision in step S103, the sensor control microcomputers 23, 24 calculate the charge accumulation time and amplification gain in the case of controlling for scene analysis, and the process proceeds to step S114. As illustrated in FIG. 6B, the sensor control microcomputers 23 and 24 determine the accumulation time and the amplification gain so that the average value of the data read in step S106 approaches the average luminance target level. As the “average value of data”, a value calculated in a “scene analysis control execution determination” process described later is used.

  In step S114, the sensor control microcomputers 23 and 24 accumulate charges in the photometric sensor 19 by the “scene analysis control”, and the process proceeds to step S115. In step S115, the sensor control microcomputers 23 and 24 read the photometric signal Vout from the photometric sensor 19, and proceed to step S116.

  In step S116, the sensor control microcomputers 23 and 24 determine the data validity for the signal value after A / D conversion, and the process proceeds to step S117. The sensor control microcomputers 23 and 24 determine “no data validity” when the data indicates output saturation due to an abnormality of the photometric sensor 19. On the other hand, the sensor control microcomputers 23 and 24 determine “data valid” if the output saturation is not satisfied.

  In step S117, the sensor control microcomputers 23 and 24 turn off the execution flag and return to step S103.

(Control execution judgment process for scene analysis)
FIG. 9 is a flowchart for explaining the flow of the scene analysis control execution determination process performed by the sensor control microcomputers 23 and 24. The process according to FIG. 9 corresponds to step S112 in FIG. In step S201 of FIG. 9, the sensor control microcomputers 23 and 24 calculate an average luminance value for each of the divided areas of the photometric sensor 19, and the process proceeds to step S202. The reason for calculating for each divided area is that the luminance difference between the divided areas is affected by the noise contained in the signal or pixel defects are generated, compared to the case where the luminance difference is calculated for each pixel. It is because it becomes difficult to receive the influence of the abnormal value. Instead of calculating the average luminance value for each divided area, the average value of the G color signal may be calculated.

In step S202, the sensor control microcomputers 23 and 24 calculate the maximum luminance and the minimum luminance in each divided area, and proceed to step S203. In step S203, the sensor control microcomputers 23 and 24 calculate the logarithmic luminance difference dBv between the divided areas using the following equation (1).
dBv = Log2 (BvMax / BvMin) (1)
However, dBv is the luminance difference between the divided regions, BvMax is the maximum luminance of the divided regions, and BvMin is the minimum luminance of the divided regions.

  In step S204, the sensor control microcomputers 23 and 24 determine whether or not the luminance difference between the divided areas> a predetermined threshold value is satisfied. If the luminance difference> predetermined threshold is satisfied, the sensor control microcomputer 23, 24 makes an affirmative decision in step S204 and proceeds to step S205. If the luminance difference> predetermined threshold is not established, the sensor control microcomputer 23, 24 makes a negative determination in step S204 to step S207. move on. When the process proceeds to step S204, there is a possibility of shooting under the above-described backlight or shooting including a high-luminance subject. In the case of proceeding to step S207, since a high-luminance subject is not included, color information is also obtained from the signal value of the photometric sensor 19 by “photometric sensor control”. The predetermined determination threshold value is stored in advance in a nonvolatile memory (not shown) in the sensor control microcomputers 23 and 24.

  In step S205, the sensor control microcomputers 23 and 24 determine whether or not the charge accumulation time during the photometric sensor control <predetermined time is satisfied. If the charge accumulation time <predetermined time is satisfied, the sensor control microcomputer 23, 24 makes an affirmative decision in step S205 and proceeds to step S206. If the charge accumulation time <predetermined time does not hold, the sensor control microcomputer 23, 24 makes a negative determination in step S205. The process proceeds to S207. The process proceeds to step S206 when the time required for charge accumulation by the scene analysis sensor control is secured. When the process proceeds to step S207, it takes a long time to accumulate charges by the photometric sensor control, and the time required for the charge accumulation by the scene analysis sensor control is insufficient. The predetermined time is stored in advance in a nonvolatile memory (not shown) in the sensor control microcomputers 23 and 24.

  In step S206, the sensor control microcomputers 23 and 24 turn on the execution flag and end the process of FIG. When this execution flag is ON, in the photometric sensor control process (FIG. 8), charge accumulation by the scene analysis control is performed following the charge accumulation by the photometric sensor control. In step S207, the sensor control microcomputers 23 and 24 turn off the execution flag and end the process of FIG. When this execution flag is OFF, in the photometric sensor control process (FIG. 8), only charge accumulation by the photometric sensor control is performed, and charge accumulation by the scene analysis control is not performed.

According to the embodiment described above, the following operational effects can be obtained.
(1) With respect to the storage type photometric sensor 19, the “photometric sensor control” for determining the photometric range by AGC (Auto Gain Control) based on the maximum value of the photometric signal Vout and the AGC based on the average value of the photometric signal Vout Since “scene analysis sensor control” for determining the photometric range is performed, it is possible to appropriately obtain information both when the information regarding the maximum luminance and the information regarding the average luminance are desired.

(2) Since “photometric sensor control” and “scene analysis sensor control” are alternatively switched, the appropriate information can be obtained without providing a plurality of photometric sensors 19.

(3) Since “photometric sensor control” is performed before “scene analysis sensor control”, it is determined whether or not the information obtained by “photometric sensor control” is “scene analysis sensor control”. It can be used as a material.

(4) If the charge accumulation time in “photometric sensor control” is long (determination of step S205 is negative), if “scene analysis sensor control” is omitted, the photometric processing is required compared to the case where both sensor controls are performed. Time can be shortened.

(5) If the output difference between the divided areas in “photometric sensor control” is small (determination is negative in step S204), if “scene analysis sensor control” is omitted, photometry is performed compared to the case where both sensor controls are performed. The time required for processing can be shortened.

(6) Since the output difference of (5) above is obtained from the average value of the luminance or the average value of the G signal obtained through the color filter 19c, it is suitable for determination of shooting under backlight or shooting including a subject with high luminance. It is. If it is determined that the shooting is under backlight or includes a high-luminance subject, “scene analysis sensor control” is performed to obtain information on the average luminance. From the information obtained through the color filter 19c by “scene analysis sensor control”, the color information about the non-bright area can be obtained without overexposure.

(7) Exposure calculation is performed using the output value (information relating to the maximum luminance) of the photometric sensor 19 subjected to “photometric sensor control”, and the output value (information relating to the average luminance) output from the photometric sensor 19 subjected to “scene analysis sensor control” Is used to determine the area where the main subject exists, and focus adjustment information during AF processing is acquired for the area. Thereby, compared with the case where the focus adjustment information at the time of AF processing is acquired for all regions, the processing load and time can be reduced.

(8) When “scene analysis sensor control” is omitted, an area where the main subject exists is determined using the output value (information on the maximum luminance) of the photometric sensor 19 that has been “photometric sensor control”, and the area is Focus adjustment information at the time of AF processing is acquired for the target. Thus, even when “scene analysis sensor control” is omitted, it is not necessary to acquire focus adjustment information at the time of AF processing for all regions.

  The above description is merely an example, and is not limited to the configuration of the above embodiment. For example, an electronic camera or a film camera may be used as long as the camera includes the above-described photometric device, and the present invention may be applied to a camera different from the single-lens reflex type.

It is a figure explaining the principal part structure of the electronic camera carrying the photometry apparatus by one embodiment of this invention. It is a flowchart explaining the flow of the imaging | photography process which an imaging | photography control circuit performs. It is a figure explaining a photometric sensor. It is a figure explaining area division of a photometric sensor. (a) is a figure explaining the photometry range of a photometry apparatus, (b) is a figure explaining the dynamic range of a photometry sensor. (a) is a diagram illustrating an image (luminance information) obtained by “photometric sensor control”, (b) is a diagram illustrating an image (luminance information) obtained by “scene analysis sensor control”, (c) FIG. 7 is a diagram illustrating an image (color information) obtained by “photometric sensor control”, and (d) is a diagram illustrating an image (color information) obtained by “scene analysis sensor control”. It is a flowchart explaining the flow of the photometry process which a sensor control microcomputer performs. It is a flowchart explaining the flow of the photometry sensor control processing which a sensor control microcomputer performs. It is a flowchart explaining the flow of the control execution determination process for scene analysis which a sensor control microcomputer performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Camera body 12 ... Shutter 13 ... Imaging element 19 ... Photometry sensor 19c ... Color filter 23, 24 ... Sensor control microcomputer 25 ... Shooting control circuit

Claims (10)

A storage-type photometric sensor;
Accumulation for performing first control for accumulating and controlling the photometric sensor based on the maximum output value obtained by the photometric sensor, and for performing second control for accumulating and controlling the photometric sensor based on an average output value from the photometric sensor. And a control means. The photometric device according to claim 1,
The photometry apparatus according to claim 1, wherein the accumulation control unit selectively switches between the first control and the second control. The photometric device according to claim 2,
The photometry apparatus according to claim 1, wherein the accumulation control means performs the first control before the second control. In the photometric device as described in any one of Claims 1-3,
The accumulation control means determines the accumulation time and gain of the photometric sensor so that the maximum value of the output does not exceed the saturated output level of the photometric sensor during the first control, and during the second control, A photometric device that determines an accumulation time and a gain of the photometric sensor so that an average output value of the photometric sensor falls within a predetermined range based on the accumulation time and the gain during the first control. . The photometric device according to claim 4,
The photometry device according to claim 1, wherein the accumulation control means does not perform the second control when the accumulation time of the photometry sensor during the first control is longer than a predetermined time. The photometric device according to claim 4,
The photometric sensor is configured to divide a light receiving surface of a light beam into a plurality of regions and obtain the output for each region,
In the first control, the accumulation control unit does not perform the second control when a difference between the outputs in the plurality of regions is a predetermined value or less. The photometric device according to claim 6,
A color filter,
The difference in output between the areas of the photometric sensor is obtained from a luminance value of a light beam received by the photometric sensor through the color filter or an output value of a predetermined color. A photometric device according to any one of claims 1 to 4,
A color filter,
Luminance information based on the output of the photometric sensor obtained by the second control with respect to the light flux that has passed through the color filter is subjected to exposure control using luminance information based on the output of the photometric sensor obtained by the first control. An imaging apparatus comprising: an imaging control unit that performs focus detection control using color information. A photometric device according to any one of claims 1 to 4,
Photographing means;
A color filter,
Analyzing means for analyzing a scene photographed by the photographing means using color information and luminance information based on an output of the photometric sensor obtained by the second control with respect to the light flux that has passed through the color filter. An imaging device. A photometric device according to claim 5 or 6,
Photographing means;
A color filter,
Analyzing means for analyzing a scene photographed by the photographing means using color information and luminance information based on an output of the photometric sensor obtained by the first control with respect to the light flux that has passed through the color filter. An imaging device.

Images