JPH06138514A - Photometry device for camera - Google Patents

Abstract

PURPOSE:To obtain a proper exposure signal by preventing influence by blooming, a smear, etc., due to the existence of an extremely high brightness region, in a photometry device executing divided photometry. CONSTITUTION:This photometry device for a camera is equipped with a photometry means 25 dividing the brightness of an object into plural regions to execute photometry and outputting plural photoelectric conversion signals, a correcting means 101 correcting the signal values of plural regions, that is, a region where a signal showing the brightness of a prescribed value or more exists and the surroundings of the region, when the existence of the signal in plural photo electric conversion signals is detected and a calculating means 101 executing calculation based on the signal values corrected by the correcting means and outputting the signal on an exposure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photometric device for a camera, and in particular, in the case where the brightness of an object is divided into a plurality of regions for photometry, when a partial region is irradiated with excessive intensity of light. Also relates to technology that enables appropriate photometry.

[0002]

2. Description of the Related Art Conventionally, a camera is provided with a photometric device for measuring the brightness of an object in order to perform an appropriate exposure. Based on the photometric brightness value obtained by such a photometric device, the shutter time and the aperture value are determined so that the exposure amount given to the film by the processing circuit in the camera becomes appropriate.

In such a photometric device,
In the past, for example, only the central part was focused on, but in recent years, it has become common to measure the brightness of a subject at a plurality of parts. Such a photometric method is generally called divided photometry, in which the subject is divided into a total of 5 or more locations in the central portion and a plurality of peripheral portions, and the luminance state of the main subject and its peripheral portions is measured. Optimal exposure conditions are required in consideration.

In such divisional photometry, the larger the number of divisions, the more detailed the luminance distribution of the main portion and the peripheral portion can be obtained, and the accuracy of exposure conditions can be increased. It is obvious that the number is naturally increasing. In the future, it is expected that the number of divisions will increase to several tens to several hundreds by improving the light receiving element.

A semiconductor element such as a silicon photodiode is generally used as a light receiving element for performing the above-described divided photometry, and outputs a current proportional to the intensity of the irradiated light.

[0006]

However, in a silicon photodiode as a light receiving element used for the above-described divided photometry, when a partial element region is irradiated with excessive intensity of light, it is generated there. There is a problem that an electric current flows into the elements in the adjacent regions and an error occurs in the original output. That is, the silicon photodiode in each element region is provided with a potential barrier between regions so that the charges generated in one region do not enter the adjacent region. However, the charges generated in the element region irradiated with light of excessive intensity cross the potential barrier and enter the adjacent region, causing an error in the detection current.

The phenomenon as described above is generally called blooming or smear due to the situation of occurrence, and the original output signal of the peripheral region including the portion irradiated with light of excessive intensity is destroyed. With a secondary sensor used in a video camera or the like, even if such blooming occurs, it can be easily detected by monitoring the monitor image, and measures such as changing the aperture value of the lens can be taken.

However, in a general camera for photographing, calculation is executed based on the signal output from the light receiving element, and as a result, it is simply displayed as each control value of the shutter time or aperture. Absent. Therefore, even if there is an error in the signal used in the process of calculation, there is a problem that it is not noticed until the film is developed.

Therefore, an object of the present invention is to make it possible to obtain an appropriate exposure condition without being adversely affected by blooming, smearing, etc. even in an object having a partially high brightness.

[0010]

In order to achieve the above object, a camera photometric device according to the present invention comprises a photometric device which divides the brightness of an object into a plurality of regions to perform photometry and outputs a plurality of photoelectric conversion signals. A correction that corrects the signal values of a region in which the signal exists and a plurality of regions around the region by a predetermined amount when it is detected that a signal having a brightness equal to or higher than a predetermined value exists in the plurality of photoelectric conversion signals. It is characterized by comprising means and means for calculating based on the signal value corrected by the correcting means and outputting a signal relating to exposure.

The correction means includes a region in which a signal having a brightness equal to or higher than the predetermined value is present, and corrects the signal values of a plurality of regions around the region, or indicates a brightness equal to or higher than the predetermined value. It is convenient to configure so as to correct the signal value of a region along at least one predetermined direction from the region where the signal exists.

Further, it is convenient that the correction means replaces a signal having a brightness equal to or higher than the predetermined value with a signal having a predetermined maximum value or lower, and the presence of a signal having a brightness equal to or higher than the predetermined value. It is convenient to perform the correction by multiplying the signals of a plurality of areas around the area to be multiplied by a predetermined correction coefficient smaller than 1.

[0013]

In the above structure, the signals showing the brightness of the predetermined value or more in the plurality of photoelectric conversion signals are replaced with, for example, the signals of the predetermined maximum value or less, and the signal values of the plurality of areas around the area are changed. Is corrected by, for example, multiplying a predetermined correction coefficient smaller than 1. Therefore, even if there is an extremely high brightness area, the area and the surrounding area are appropriately corrected, and the exposure condition is appropriately set without being adversely affected by blooming or smear.

When blooming occurs due to the presence of an extremely high-luminance region, the signal values of a plurality of regions around the region in which a signal having a luminance equal to or higher than the predetermined value exists is corrected. The appropriate exposure condition can be determined by, and when smear occurs, the signal of the region along the predetermined direction determined by the configuration of the light receiving element from the region where the signal indicating the brightness of the predetermined value or more exists Appropriate exposure information can be obtained by correcting the value.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing an example of a camera incorporating a camera photometric device according to the present invention. The camera shown in the figure is constructed by disposing a lens 4, a finder 2, and a back cover 3 on a camera body 1 in a removable structure. The lens 4 can be attached to and detached from a mount portion (not shown), the fan 2 can be attached to and detached from a screen portion 8 as shown, and the back cover 3 can be attached to and detached from a film storage portion (not shown).

Further, the camera body 1 is provided with a shutter button 5, a display means 6 on the upper right side, and various setting buttons 7 on the upper left side. The shutter button 5 has a two-stage switch incorporated therein. When the shutter button 5 is half-pressed, a power switch for starting power supply to the circuit is turned on, and when fully pressed, a release switch for starting an exposure operation is turned on.

The subject light that has passed through the lens 4 is projected on the screen portion 8. In front of the screen portion 8, a contact group 9 that faces upward is arranged. Further, the detachable viewfinder 2 is provided with a contact group 11 facing downward in addition to an eyepiece 10 for visually recognizing a subject. The contact point group 11 has a function of contacting the contact point group 9 of the camera body 1 to exchange signals. Further, the back cover 3 is configured to be openable / closable and removable via a hinge (not shown).

FIG. 2 schematically shows an optical system of the camera body 1, the lens 4, and the finder 2 shown in FIG. In FIG. 2, light from a subject (not shown) passes through the lens optical system 20 in the lens 4, is reflected upward by the reflection mirror 21, and forms an image on the screen 22. The formed subject image is reflected by the pentaprism 23, and a part thereof enters the observer's eye 26 via the half mirror 24. A part of the subject image reflected upward by the half mirror 24 enters a two-dimensional sensor (hereinafter, simply referred to as a sensor) 25.

The sensor 25 may be a generally used sensor, which divides the subject brightness into a plurality of areas for photometry and outputs a photometric signal corresponding to each area. Then, a processing circuit, which will be described later, performs a predetermined calculation on the basis of these photometric signals and a signal representing the sensitivity of the film being used to obtain the optimum exposure condition.

FIG. 3 shows an example of an electric circuit provided in the camera body 1. The circuit of FIG. 3 has a battery 70 for power supply.
A DC-DC converter 71, a film sensitivity detection circuit 72, a switch group 73, a CPU 74, and a drive circuit 75 for driving each unit. The drive circuit 75 includes a shutter 76, a diaphragm 77, motors 78 and 79, and a lamp 8.
0, auxiliary light source 81, focus detection element 82, etc. are connected.

The battery 70 supplies power to all the circuits in the camera body 1 via the DC-DC converter 71 and the circuits in the finder 2 via the contacts 83 at, for example, 5 volts. Note that the DC-DC converter 71 also supplies power to the circuit inside the back cover 3, but the contacts for this are not shown. The other contacts 84, 85, 86 together with the contact 83 constitute a signal transmitting / receiving contact for the finder 2.

The CPU 74 controls the whole operation,
To the CPU 74, a signal indicating the sensitivity of the film from the film sensitivity detection circuit 72 and signals related to various switches are input from the switch group 73. For example, commands or status signals from the shutter button 5, the selection button 7, a sequence switch (not shown), etc. are input from the switch group 73. In addition to the CPU74,
A focus matching state signal from the focus detection element 82 is input. Further, each of the contacts 83, 84, which constitute the contact group 9,
A signal relating to the proper exposure condition from the finder 2 is input from the inner contact 85 of the 85 and 86.

On the other hand, as signals output from the CPU 74, first, a signal for controlling the exposure time by opening and closing the shutter 76 via the driving means 75, a control signal for limiting the subject light by setting the diaphragm 77 to a predetermined value, A signal for controlling the winding and rewinding of the film by turning on and off the motor 78, the motor 79
There is a control signal for turning on and off to bring the lens 4 into focus. Further, a signal for controlling the lighting of the lamp 80 for reducing the so-called red-eye phenomenon by closing the pupil of the subject from the CPU 74 via the drive circuit 75, and performing the focus detection function by illuminating the subject with a predetermined pattern of light when the luminance is low. A signal for controlling the auxiliary light source 81 for assisting and a signal for driving the focus detection element 82 are also output. Although not shown in the figure, the display drive of the display unit 6 formed by the LCD or the like on the upper surface of the camera body 1 is also performed. The CPU 74 further sends a film sensitivity signal to the finder 2 via the contact 84, as will be described later.

FIG. 4 shows a schematic structure of an electric circuit in the finder 2. The circuit shown in the figure includes a CPU 101, a drive circuit 102, a memory circuit 104, and the like. Further, the contacts 93, 94, 95, 96 are contacts for exchanging signals with the camera body 1.

In the circuit of FIG. 4, the CPU 101 drives the sensor 25 via the drive circuit 102, and the sensor 25
The luminance of the subject is measured by the sensor, and the resulting subject image signal is received from the sensor 25. The subject image signal is temporarily stored in the storage circuit 104, and is read out again for use when necessary such as when calculating the optimum exposure condition. Further, a film sensitivity signal is input from the camera body 1 via the contact 94, and the CPU 101 calculates the optimum exposure condition based on the film sensitivity signal and the subject image signal described above. Then, an appropriate exposure signal representing the calculated optimum exposure condition is output to the camera body 1 via the contact 95.

Next, the operation of the photometric device provided in the camera having the above structure will be described. FIG. 5 shows an example of ideal subject image recognition in the sensor 25 (FIG. 4) described above. That is, FIG. 5 schematically illustrates a state in which the luminance of the subject corresponding to each detection region detected by the sensor 25, that is, the subject image is stored in the storage circuit 104. In FIG. 5, the point light sources 116 and 117 are placed at the positions shown in the uniformly dark luminance region.
Exists. Since FIG. 5 shows an ideal state, the point light sources 116 and 117 are present only in the detected pixels and have no effect on the surrounding dark part.

The image signal blooming and smear peculiar to the sensor 25 when the subject is a high-intensity point light source will be described below. FIG. 6 is an example in which a so-called blooming phenomenon occurs, and shows an example of subject image recognition when the subject image signal obtained by the sensor 25 is stored in the storage circuit 104. In FIG. 6, the high-intensity point light source 11
It can be seen that it is recognized that the areas 118 and 119, which should originally be dark areas, around 6 and 117 have a certain degree of brightness in a plane.

In such blooming, excess charges generated by a high-brightness light source or from a signal transfer circuit flow into peripheral pixels or circuits, so that not only the specific light receiving portion but also its peripheral portion. It is a phenomenon that occurs because it is equivalent to a bright situation. In this case, the amount of influence on the surroundings varies depending on the difference between the brightness of the point light source and the amount of ambient light, but in general, the central point light source becomes the original brightness and gradually shifts to low brightness in the periphery. Becomes

FIG. 7 shows an example of so-called smear phenomenon. In the figure, the parts 121 and 122 below the point light sources 116 and 117, which are originally supposed to be dark parts, are shown.
A linear low-brightness part is generated in the area. Such a smear occurs only in a so-called frame transfer type two-dimensional sensor that performs a light receiving operation even during signal transfer among the two-dimensional sensors. And depending on the direction of signal transfer,
A low brightness part may occur above the point light source.
In the case of such a smear, the amount of influence on the surroundings is different from that in the case of blooming, and is determined by the driving time factors such as the brightness of the point light source and the transfer time.

The blooming and smear as described above are expected to have a serious influence when the sensor 25 is used for the purpose of photometrically measuring the brightness of an object as in this embodiment. For example, when the sun image is captured in a part of the subject, the portion around the sun, which should have normal brightness, is erroneously recognized as being in a brighter condition because of the brightness of the sun. For this reason, if this is left as it is, the calculation result of underexposure will result, and the optimum exposure condition cannot be obtained.

In the present invention, for example, the following processing is performed in order to eliminate the adverse effect caused by such blooming or smear. This process will be described with reference to FIG.

First, in the case of blooming, if there is signal data indicating a brightness equal to or higher than a predetermined value, first, a central region in which signal data indicating a brightness equal to or higher than the predetermined value exists is specified, and the central region is specified. The luminance signal of is replaced with a signal having a predetermined maximum value or less, and the signal level of the peripheral data is reduced at a constant rate.

FIG. 8 is a partial view of the signal data map stored in the storage circuit 104 described above. In this figure, DMN (M and N are integers) indicates that it is the measurement data of the light receiving unit in the M rows / N columns of the sensor 25. Therefore, the signal data D55 existing in the center of FIG.
Is the measurement data of the 5th row / 5th column of the sensor 25.

In FIG. 8, it is assumed that the data for the point light source 116 in FIG. 6 corresponds to the signal data D55 in FIG. 8, a very high brightness value is stored in D55, and the influence of the blooming described above is caused. It is assumed that it appears in each signal data around it.

In order to eliminate such an adverse effect due to blooming, in the present invention, it is first determined whether or not there is a luminance signal of a predetermined value or more in the output from the light receiving portion of each pixel of the light receiving sensor. By this determination, for example, it is assumed that only the signal data D55 stores a luminance signal of a predetermined value or more. In this case, first, the signal data D55 is replaced with a predetermined value less than or equal to a predetermined maximum value and stored. This is called high brightness cut processing. Therefore, after this processing, there is no signal data larger than the predetermined value in the memory circuit 104.

Next, the signal data D44, D45, D46, D54, D5 around the data D55 is provided.
A process of reducing the luminance signals stored in 6, D64, D65, and D66 to a fixed ratio is performed. The proportion in this case is
For example, the brightness may be determined to be optimum according to the characteristics of the sensor 25. If necessary, the peripheral signal data of these peripheral signal data D44, ..., And D66 is sequentially reduced to a fixed ratio.

Next, with respect to the influence of smear, when there is signal data indicating a brightness equal to or higher than a predetermined value, the center thereof is first specified, and the light receiving sensor 25 and other components are arranged in a fixed direction. , The signal level of the peripheral data existing in the downward direction is reduced at a constant rate. That is, the above-described blooming processing may be applied only to pixels in a certain direction.

This process will be described with reference to the signal data map of FIG. 8. Assume that the area 116 in FIG. 7 corresponds to the signal data D55 of FIG.
Only the very bright values are assumed, and the smear effect mentioned above lies below. in this case,
First, it is determined whether or not the signal data of each light receiving portion of the light receiving sensor 25 has a brightness of a predetermined value or more, and it is detected that the signal data D55 has a brightness of a predetermined value or more. In response to this detection, the value of the signal data D55 is replaced with a predetermined value equal to or smaller than a predetermined maximum value and stored. That is, the above-described high brightness cut processing is performed. Next, a process of reducing the luminance signal stored in the signal data D65, D75, ... Corresponding to each pixel below the high luminance region to a certain ratio is performed. In this case, the decrease rate may be determined according to the characteristics of the sensor 25 so that the corrected brightness level becomes an appropriate value.

Next, the correction processing as described above will be described with reference to FIGS.
This will be described in more detail with reference to FIG. FIG. 9 shows an example of processing performed by the CPU 74 in the camera body 1. The processing routine of FIG. 9 is performed by the DC-DC converter 7
It is repeatedly executed while the power is applied to the CPU 74 by the activation of 1. First, in step S1, the sensitivity of the film used is detected via the film sensitivity detection circuit 72. Then, in step S2,
Performs the first data communication with the finder 2, then step S
The signal representing the film sensitivity obtained in 1 is transmitted to the finder 2.

Next, in step S3, the second data communication with the finder 2 is performed, and the signal transmission from the finder 2 is awaited. That is, in the finder 2, the proper exposure signal is calculated using the film sensitivity signal obtained in step S2, and the result is calculated.
It will be sent to the side. When the proper exposure signal is obtained from the finder 2, the display corresponding to the proper exposure signal, for example, the shutter time and the aperture value, is displayed on the display means LCD 6 in step S4.

Next, in step S5, it is determined whether or not the exposure operation is instructed by the operation of the shutter button 5, and if it is not instructed, the process returns to step S1 and the processing is repeated. If the exposure operation is instructed in step S5, the process proceeds to step S6, and first, the mirror 21 shown in FIG. 2 is raised and retracted from the optical path. Next, in step S7, the diaphragm 77 in the lens 4 is controlled to a predetermined value based on the above-mentioned proper exposure signal. Further, in step S8, the shutter 76 is opened for a predetermined time based on the above-mentioned appropriate exposure signal, and the film is exposed. Since the exposure operation is completed as described above, in step S9, the winding motor 78 is rotated to wind the film by one frame, and the process returns to step S1 to prepare for the next exposure, and the above processing is repeatedly executed.

FIG. 10 shows a processing procedure of the CPU 101 in the finder 2 shown in FIG. The routine of FIG. 10 is
When the DC-DC converter 71 in the camera body 1 is activated, power is supplied into the finder 2 via the contact 93, and is repeatedly executed while the power is applied to the CPU 101. First, in step S15, the camera body 1 waits for data communication. This communication is
It corresponds to the processing step S2 of the camera body 1. In step S16, the film sensitivity signal obtained from the camera body 1 is temporarily stored in the storage circuit 104.

Next, in step S17, subject light is accumulated in the sensor 25 via the drive circuit 102. This is an operation in which electric charges generated by subject light received by a plurality of light receiving elements in the sensor 25 are stored in the internal microcapacitance element, and a darker subject requires a longer storage time.
Then, in step S18, the drive circuit 102 reads the charge signal in the sensor 25 in time series, and in step S19, the read analog signal is converted into a digital signal and stored in the memory circuit 104. Then, in step S20, it is determined whether or not the signals of all the divided light receiving elements of the sensor 25 have been received, and the signals from all the light receiving elements are received in step S1.
The process of 8 and S19 is repeated.

If it is determined in step S20 that the signals of all the divided light receiving elements have been received, the process proceeds to the correction subroutine of step S21 to execute the correction process. As will be described in detail later, this correction processing is to reproduce the subject image signal stored in the storage device 104 and remove the influence of blooming or smear.

Next, in step S22, a predetermined calculation is performed on the basis of all the object image signals corrected by the correction process and the film sensitivity signal stored in step S16 to calculate the proper exposure condition. . Then, in step S23, step S3 of FIG.
The data communication with the camera body 1 corresponding to is performed, and the signal representing the proper exposure condition obtained in step S22, that is, the proper exposure signal is transmitted to the camera body side. Then, it returns to step S15 and repeats the above process.

Next, the correction process in step S21 of FIG. 10 will be specifically described. First, a correction process when a blooming countermeasure is taken will be described with reference to FIG. In FIG. 11, first, in step S25, it is determined whether or not there is data indicating a predetermined brightness or higher in the M × N signal data from the sensor 25. If there is no data indicating a predetermined brightness or higher, the process returns to step S22 in the main routine.

In step S25, if there is data indicating a predetermined luminance or more, in step S26,
Raw signal data having a predetermined brightness or higher is set as DMN, and the value of this signal data DMN is replaced with a predetermined maximum value Dmax. As a result, there is no value above the predetermined value in the signal data. In the routine of this embodiment,
The description will be made assuming that there is only one data having a predetermined brightness or more. However, if there is a plurality of data having a predetermined brightness or more, for example, the data showing all the predetermined brightness or more is set to a predetermined maximum value D.
This can be dealt with by substituting max and correcting the data around it.

Then, in step S27, the process shown in FIG.
As described above, in order to reduce the peripheral signal data affected by blooming at a constant rate, first, the raw signal data D (M-
1) Replace the signal data of (N-1) with a value multiplied by the correction coefficient α which is a constant smaller than 1. Next, step S2
8, the raw signal data D directly above the signal data DMN
Replace (M-1) N with the value multiplied by the constant α. Next, in step S29, the raw signal data D (M-1) (N + 1) at the upper right of the signal data DMN is replaced with a value multiplied by a constant α. Next, in step S30, the raw signal data DM (N-1) on the left side of the signal data DMN is replaced with a value multiplied by a constant α. Further, in step S31, the raw signal data DM (N
Replace +1) with the value multiplied by the constant α. Further, in step S32, the raw signal data D (M + 1) (N-1) at the lower left of the signal data DMN is replaced with a value multiplied by a constant α. Further, in step S33, the raw signal data D (M + 1) N immediately below the signal data DMN is set to a constant α.
Replace with the value multiplied by. Finally, in step S34, the raw signal data D (M +
1) After replacing (N + 1) with a value multiplied by a constant α, the process returns to the main routine.

The above process is a process for affecting only one peripheral pixel adjacent to the high-luminance region due to blooming, but if it is considered to affect two peripheral pixels, the following process is performed. Perform any kind of processing. That is, similar to the above processing, first, the data (D5
5)), and the peripheral signal data D44, D45, D46, D54, D56, D6.
4, the luminance signals stored in D65 and D66 are reduced at a constant first rate (the above α), and signal data D33 to D37, D43, D47,
Similarly, the processing of reducing the signal data of D53, D57, D63, D67, and D73 to D77 at a constant second ratio (generally, a correction width smaller than the above α) is performed. The first and second ratios are set here because it is considered that the influence of the signal data D55 of the central high-luminance region is small toward the periphery. The respective correction ratios in this case may be set so that an optimum correction amount can be obtained according to the characteristics of the sensor 25.

Further, when it is expected that the area outside the surrounding two pixels will be affected, the same processing as described above may be sequentially performed. In addition, when the influence on the surrounding pixels is different depending on the central brightness value indicating high brightness, the correction coefficient is changed according to the value of the central brightness value indicating high brightness, or when the normal high brightness value is set. It is also possible to correct only the peripheral one pixel and to correct the peripheral two pixels or more pixels only when the brightness value is extremely high.

Next, the processing for correcting smear will be described with reference to FIG. First, step S
At 40, it is determined whether or not there is data indicating a brightness equal to or higher than a predetermined value among the M × N signal data of the sensor 25. If there is no data indicating the brightness equal to or higher than the predetermined value, the process returns to step S22 of the main routine of FIG.

In step S40, if there is data indicating a predetermined value or more, the process proceeds to step S41, and the raw signal data indicating the brightness equal to or more than the predetermined value is DMN,
A high-luminance cut process is performed to replace this value DMN with a predetermined maximum value Dmax. As a result, there is no value larger than the maximum value Dmax in the signal data.

Next, in step S42, as described with reference to FIG. 8, the signal data on the lower side of the maximum luminance area affected by smear is reduced at a constant rate. Raw signal data D underneath
It is replaced with a value obtained by multiplying (M + 1) N by a predetermined correction coefficient β smaller than 1. Next, in step S43, the raw signal data D (M + 2) N further below is replaced with a value multiplied by a constant β. Similarly, the lower side signal data is sequentially corrected by the correction coefficient β, and finally, in step S44, the lowermost raw signal data D (M + n) N is replaced with the value multiplied by the correction coefficient β. To finish.

In the above processing, it is explained that there is only one data indicating the brightness equal to or higher than the predetermined value.
In the case of being present at a plurality of locations, all the data having a predetermined brightness or higher may be cut, and the data below the region having the data having the predetermined brightness or higher may be sequentially corrected in the same manner. Further, the above processing example has been shown as an example in which the high-brightness subject has affected all of the lower part of the image, but if the direction of the influence is opposite or the pixels at a limited distance are affected, The correction may be made according to the direction and range of the influence.

[0055]

As described above, according to the present invention, blooming or smear occurs due to the presence of an extremely high-luminance region in a part of an image of a subject, and peripheral pixel signals are affected. Even in the condition, the exposure condition can be appropriately determined, and the disadvantage that the inappropriate exposure is performed by calculating the peripheral pixel signal which is not appropriate due to the influence of the extremely high brightness area as in the conventional case is eliminated. It

[Brief description of drawings]

FIG. 1 is an external view showing an example of a camera system in which a camera photometric device according to the present invention can be used.

FIG. 2 is an optical path diagram showing a path of subject light in the camera system of FIG.

3 is a block diagram showing an electric circuit inside a camera body in the camera system of FIG.

FIG. 4 is a block diagram showing an example of an electric circuit in a finder in the camera system of FIG.

FIG. 5 is a schematic diagram showing an image recognition result by the sensor 25 in a normal brightness state.

FIG. 6 is a schematic diagram showing an image recognition state when blooming occurs due to a high-luminance subject.

FIG. 7 is a schematic diagram showing an image recognition state when smear occurs due to a high-luminance subject.

8 is an explanatory diagram showing a data array of each pixel in a specific area of the sensor 25. FIG.

9 is a CPU in the camera body of the camera system of FIG.
5 is a flowchart showing the processing procedure of step S1.

10 is a viewfinder CPU of the camera system of FIG.
5 is a flowchart showing the processing procedure of step S1.

11 is a flowchart showing a blooming correction process in the process of FIG.

FIG. 12 is a flowchart showing smear correction processing in the processing of FIG.

[Explanation of symbols]

1 Camera Body 2 Finder 3 Back Lid 4 Lens 5 Shutter Button 6 Display 7 Setting Button 8 Screen 9 and 11 Contact Group 10 Eyepiece 20 Lens Optical System 21 Reflection Mirror 22 Screen 23 Penta Prism 24 Half Mirror 25 Two-dimensional Sensor 70 Battery 71 DC-DC converter 72 Film sensitivity detection circuit 73 Switch group 74 CPU 75 Drive circuit 83, 84, 85, 86, 93, 94, 95, 96 Contact group 101 CPU 102 Drive circuit 104 Memory circuit 116, 117 High Luminance area 118,119 Blooming area 121,122 Smear area

Claims (6)

[Claims] 1. A photometric unit that divides the brightness of an object into a plurality of regions to perform photometry and outputs a plurality of photoelectric conversion signals, and a signal indicating a brightness equal to or higher than a predetermined value among the plurality of photoelectric conversion signals. In the case of detection of the exposure signal, a correction unit that corrects the signal values of the region where the signal exists and a plurality of regions around the region by a predetermined amount, and an operation based on the signal value corrected by the correction unit, A photometric device for a camera, comprising: an arithmetic means for outputting a signal. 2. The photometric device for a camera according to claim 1, wherein the correction unit includes a region in which a signal having a luminance equal to or higher than the predetermined value exists, and corrects the signal values of a plurality of regions centered on the region. apparatus. 3. The photometric device for a camera according to claim 1, wherein the correction unit corrects a signal value of an area along at least one predetermined direction from an area where a signal having a brightness equal to or higher than the predetermined value exists. 4. The photometric device for a camera according to claim 1, wherein the correction unit replaces a signal indicating a luminance equal to or higher than the predetermined value with a signal equal to or lower than a predetermined maximum value. . 5. The correction unit according to claim 4, wherein the correction unit performs correction by multiplying signals of a plurality of regions around a region where a signal having a brightness equal to or higher than the predetermined value exists by a predetermined correction coefficient smaller than 1. Photometric device for cameras. 6. The photometric device for a camera according to claim 5, wherein the correction coefficient has a different value in an area closer to an area where a signal having a luminance equal to or higher than the predetermined value is present and in an area farther from the area.