JP3471923B2 - camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a camera such as a single-lens reflex camera provided with a photometric means for measuring the brightness of a plurality of areas within a photographing screen.

[0002]

2. Description of the Related Art Conventionally, a plurality of distance measuring points (focus detection areas) are provided within a photographing range, and an arbitrary distance measuring point is selected to perform distance measurement (focus detection). Various automatic focus detection devices of a plurality of distance measuring methods have been proposed.

For example, an automatic focus detection apparatus using a passive AF method (basic AF) that uses natural light of a subject performs distance measurement at a plurality of distance measuring points, and the photographer uses the distance measuring results of the plurality of distance measuring points. Is selected and estimated. Then, the focus state of the taking lens is controlled based on this distance measurement information.

As a method of estimating one focus detection point intended by the photographer, there is a method of selecting the closest focus detection point.

As a method of calculating the exposure amount from the brightness of the subject, the brightness of the subject is calculated from the brightness information of each area within the shooting range by using a photometric sensor that divides the area within the shooting range into a plurality of areas. A method of calculating the exposure amount by using the above method has already been proposed.

Further, when calculating the brightness of the subject, it is judged from the brightness information of each area within the photographing range whether or not the light ray state of the subject is a back light, and if the light is a back light, a predetermined amount is corrected,
Various methods have been proposed to calculate the exposure amount so that the main subject is properly exposed even under the backlight condition.

Further, the above-described automatic focus detection apparatus of a plurality of distance measuring systems for measuring a plurality of points within the photographing screen and the above-mentioned sensor for dividing the photographing range into a plurality of areas to perform photometry are used. Various methods have been proposed in which a distance measuring point intended by a photographer is obtained from a detection device, and the distance measuring point is used as a main subject, and the main subject is weighted to calculate an exposure amount.
By doing so, since the weighted calculation is performed on the main subject, it is possible to take a photograph in which the main subject is emphasized.

Further, as described above, when the brightness of the subject is calculated, from the brightness information of each area within the above-mentioned photographing range,
The brightness difference between the brightness of the main subject and the surroundings of the main subject, and the brightness difference between the brightness of the surroundings of the main subject and the brightness of the background area determine whether the light state is backlit or not, and the amount of correction for backlighting. A method of asking for is also proposed.

[0009]

However, as in the above-mentioned conventional example, the luminance difference between the luminance of the main subject and the luminance around the main subject, and the luminance between the luminance around the main subject and the luminance of the background portion. The method of determining the backlight from the difference and obtaining the correction amount at the time of backlight has the following problems.

Generally, when a still subject is photographed, since the main subject and the background are both still, the brightness of the main subject, the brightness around the main subject, and the brightness of the background portion are constant. The amount of correction during backlighting is constant. Therefore, when shooting a still subject, for example,
In the case of photographing a portrait or the like, it works extremely effectively.

However, in the case of photographing a moving object, for example, in a race of a bicycle, when photographing while following a competitor, even if the main subject is continuously chased, the surroundings of the main subject, and , The background changes from moment to moment. In such a situation, an object that was in the background at some time would go around the main subject, and an object that was around the main subject would often go in the background. If the object has a high brightness enough to affect the backlight condition, it may or may not be backlit depending on whether the object is in the background or around the main subject. Or, the correction amount at the time of backlighting may change, and as a result, the exposure amount varies.

( Object of the Invention) An object of the present invention is to provide a moving object in a case where the object is continuously tracked and photographed.
Even changes is greater than or equal exposure correction amount by a change in the delicate position of an object in the background, it is possible to suppress variations in exposure amount due to the change in the exposure correction amount, further,
Even if the exposure correction amount changes significantly, the appropriate exposure
Is to provide a camera that can give .

[0013]

[0014]

[0015]

[Means for Solving the Problems] In order to achieve the above object, the present invention measures the brightness of a plurality of areas in a shooting screen.
Light metering means and the exposure amount is calculated based on the output of the light metering means.
Based on the output of the calculation means and the photometric means,
Ray state determination means for determining the state, and the light state determination hand
Exposure obtained by said computing means based on the output of the stage
Exposure amount correction hand to calculate the exposure amount correction amount to correct the amount
In a camera having a step, the exposure amount correction unit stores a value corresponding to at least one exposure amount correction amount calculated in the past by the exposure amount correction unit, and the exposure amount correction unit.
The latest exposure correction amount obtained by the above is stored in the storage means.
If the value changes more than the first predetermined value, the latest
Exposure dose correction amount, while the latest exposure dose correction
The quantity is greater than the first predetermined value with respect to the stored value of the storage means.
If the change is greater than the second predetermined value, which is even greater, the latest
That the correction means that does not correct the exposure correction amount of
It is a feature .

[0016]

[0017]

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

FIGS. 1 to 3 are diagrams relating to the first embodiment of the present invention. FIG. 1 shows the optical system arrangement of the single lens reflex camera when applied to FIGS. 2 (A) and 2 (B). 3A and 3B are top and back views of the camera of FIG. 1, and FIGS. 3A and 3B are views of the viewfinder field of FIG.

In FIG. 1, reference numeral 1 designates a taking lens, which is shown as two lenses for convenience, but is actually composed of more lenses. Reference numeral 2 is a main mirror, which is obliquely installed in the photographing optical path or is retreated according to the observation state of the subject by the finder system and the photographing state of the subject image. Reference numeral 3 denotes a sub-mirror, which reflects the light flux transmitted through the main mirror 2 toward a focus detection device 6 described below below the camera body. Four
Is a shutter, and 5 is a photosensitive member, which is made of a silver salt film or the like. Reference numeral 6 denotes a focus detection device, which is arranged near the image plane and includes a field lens 6a, reflection mirrors 6b and 6c,
It is composed of a secondary imaging lens 6d, a diaphragm 6e, a sensor 6f and the like.

The focus detection device 6 in this embodiment uses a well-known phase difference method, and as shown in FIGS. 3A and 3B, a plurality of regions (5) in the observation screen (in the viewfinder field) are used.
A spot is set as a focus detection point (focus detection area), and the focus can be detected at the focus detection point. 7 is a focusing plate arranged on the planned image forming surface of the taking lens 1, 8 is a pentaprism for changing the optical path of the finder, and 9 and 10 are an image forming lens and a photometric sensor for measuring the subject brightness in the observation screen. The imaging lens 9 conjugately connects the focusing plate 7 and the photometric sensor 10 via the reflection optical path in the pentaprism 8. Reference numeral 11 denotes an eyepiece lens 11 arranged behind the exit surface of the pentaprism 8 and used for observing the focusing plate 7 by the photographer's eye 15.

Reference numeral 21 denotes a high-intensity superimposing LED that can be visually recognized even in a bright subject. The emitted light is reflected by the main mirror 2 via the light projecting prism 22 and is provided on the display portion of the focusing plate 7. Is bent in the vertical direction by the minute prism array 7a, and the penta prism 8 and the eyepiece 1
1 to reach the photographer's eye 15. Therefore, the micro prism array 7a is formed in a frame shape at a plurality of positions (distance measuring points) corresponding to the focus detection area of the focusing plate 7, and five superimposing LEDs 21 (each of which is an LED) are formed. -L1, LED-L2, LED-C, LED
-R1, LED-R2).

As a result, as can be seen from the viewfinder field shown in FIG. 3A, each distance measuring point mark 200,
201, 202, 203, and 204 illuminate in the field of view of the finder, and a focus detection area (distance measuring point) can be displayed. (Hereinafter, this is called superimpose display).

Reference numeral 23 is a field mask for forming a finder field area, and 24 is an LCD in the finder for displaying photographing information outside the field of view of the finder, which is an illumination LED (F-LE).
D) Illuminated by 25.

The light transmitted through the LCD 24 is guided into the finder field by the triangular prism 26, as shown in FIG.
As indicated by 207 in (A), it is displayed outside the viewfinder field, and the photographer can know the photographing information.

Reference numeral 31 denotes an aperture provided in the photographing lens 1,
Reference numeral 32 is an aperture drive device including an aperture drive circuit 111 described later, 33 is a lens drive motor, and 34 is a lens drive member including a drive gear and the like. Reference numeral 35 denotes a photocoupler, which detects rotation of the pulse plate 36 interlocked with the lens driving member 34 and transmits it to the lens focus adjustment circuit 110. The focus adjusting circuit 110 drives the lens driving motor by a predetermined amount based on this information and the information on the lens driving amount from the camera side to move the taking lens 1 to the in-focus position. A mount contact 37 serves as an interface between a known camera and a lens.

In FIGS. 2A and 2B, 41 is a release button, and 42 is a monitor L as an external monitor display device.
The CD is composed of a fixed segment display section 42a for displaying a predetermined pattern and a 7-segment display section 42b for displaying variable numerical values. 43 is A for holding the photometric value
The E lock button and 44 are mode dials for selecting a photographing mode and the like. Reference numeral 90 denotes a focus detection point selection button used to set the camera to the focus detection point setting state when changing the focus detection point, and reference numeral 91 denotes the camera AF when changing the AF mode.
It is an AF mode button used for setting the mode. The other operating members are not particularly necessary for understanding the present invention, and will be omitted.

FIG. 4A shows a detailed view of the mode dial 44 shown in FIG. 2. By aligning the display with the index 55 imprinted on the camera body, the photographing mode is set according to the displayed contents. .

In FIG. 4A, 44a is a lock position for disabling the camera, 44b is a position in an automatic photographing mode controlled by a photographing program preset by the camera, and 44c is a photographer who can set photographing contents. The manual shooting mode has program AE, shutter priority AE, aperture priority AE, subject depth priority AE, and manual exposure shooting modes.

FIG. 4B shows the internal structure of the mode dial 44.

Reference numeral 46 denotes a flexible printed circuit board, which has a switch pattern (M1,
M2, M3, M4) and the GND pattern are arranged as shown in the drawing, and the four contact pieces (47a, 47b, 47a, 47b, 47b) of the switch contact piece 47 which are interlocked with the rotation of the mode dial 44.
By sliding (47c, 47d), 12 positions shown on the mode dial 44 can be set by 4 bits. An electronic dial 45 is for selecting a set value that can be further selected from the modes selected by the mode dial 44 by rotating the electronic dial to generate a click pulse. For example, when the shutter priority shooting mode is set by the mode dial 44, the in-viewfinder LCD 24 and the monitor LCD 42 are set.
Indicates the currently set shutter speed. When the photographer rotates the electronic dial 45, the shutter speed is sequentially changed from the currently set shutter speed according to the rotating direction.

FIGS. 5A and 5B show the electronic dial 4
5 is a schematic view showing the internal structure of FIG.

In FIG. 5, a click plate 48 is arranged along with the dial 45, and a printed board 49 is fixed to the click plate 48. The printed circuit board 49 has switch patterns 49a (SWDIAL-1) and 49b (SWDIAL-1).
-2) and the GND pattern 49c are arranged as shown, and the switch contact piece 50 having three sliding contact pieces 50a, 50b, 50c is fixed to the fixing member 51. A click ball 52 that fits into a recess 48 a formed on the outer peripheral portion of the click plate 48 is arranged, and a coil spring 53 that biases the ball is held by the fixing member 51. In addition, the normal position (click ball 52 is recessed 4
8a), the sliding contact piece 5
0a and 50b are not in contact with either of the switch patterns 49a and 49b.

The electronic dial 4 formed in this way
5, when the photographer rotates the electronic dial 45 in the clockwise direction in FIG. 5, the sliding contact piece 50b first contacts the switch pattern 49, and then the sliding contact piece 50a moves to the switch pattern 49a. It comes into contact with and counts up at this timing. In the case of counterclockwise rotation, the relationship between the sliding contact piece 50b and the switch pattern 49 is just opposite to this, and the set value is counted down at the same timing.

FIG. 5B is a timing chart showing this state, showing the pulse signals generated in the switch patterns 49a and 49b when the electronic dial 45 is rotated, and the timing thereof.

The upper part of FIG. 5 (B) shows the case of one-click rotation in the clockwise direction, and the lower part shows the case of the counterclockwise rotation. In this way, the count-up / down timing and rotation direction are shown. Is being detected.

FIG. 6 is a block diagram showing a circuit configuration incorporated in the single-lens reflex camera in the first embodiment of the present invention, and the same portions as those in FIG. 1 are designated by the same reference numerals.

A central processing unit (hereinafter referred to as a CPU) 10 in a microcomputer incorporated in the camera body
To 0, a photometry circuit 102, an automatic focus detection circuit 103, a signal input circuit 104, an LCD drive circuit 105, an LED drive circuit 106, a shutter control circuit 108, and a motor control circuit 109 are connected. Further, the focus adjustment circuit 110 and the diaphragm drive circuit 111 arranged in the photographing lens 1 are
Signals are transmitted through the mount contacts 37 shown in FIG.

The photometric circuit 102, after amplifying the output from the photometric sensor 10, performs logarithmic compression and A / D conversion, and sends it to the CPU 100 as luminance information of each sensor.

The photometric sensor 10 has a left focus area (focus detection area) 2 in the finder field shown in FIG. 3B.
SPC-A3 for photometry of the area A3 including 00, SPC-A1 for photometry of the area A1 including the left inner focus detection point 201 in the viewfinder field, and central focus detection point 202 in the viewfinder field
SPC-A0 for photometry of the area A0 including S, and S for photometry of the area A2 including the right inside focus detection point 203 in the viewfinder field.
PC-A2, SPC-A5 for measuring the area A4 including the right distance measuring point 204 in the viewfinder field, SPC-B5 for measuring the area B5 adjacent to the upper and lower sides of the central distance measuring point 202 in the viewfinder field, and SPC-B5 in the viewfinder field Left inner AF point 20
SPC-B6 for photometrically measuring the area B6 adjacent to the upper and lower sides of
SPC-B7 that measures the area B7 adjacent to the upper and lower sides of the right inner focus detection point 203 in the viewfinder field, SPC-B8 that measures the area B8 adjacent to the upper part of the left focus detection point 200 in the viewfinder field, and the viewfinder field of view AF point 200 on the left
SPC-B9, which measures the area B9 adjacent to the lower part of the field of viewfinder, SPC-B10, which measures the area B10, which is adjacent to the upper part of the right focus area 204 in the viewfinder field, and adjacent to the bottom of the right focus area 204 in the field of viewfinder SPC-B11 for metering the area B11 to be measured, SPC-C12 for metering the outermost upper right area C12 in the viewfinder field, and SPC for metering the outermost upper left area C13 in the viewfinder field.
-C13, the area C at the lower left of the outermost edge in the viewfinder
SPC-C14 for photometry of 14 and SPC-C15 for photometry of the lower right area C15 at the outermost periphery in the viewfinder field.
, A photodiode for photometrically measuring a total of 16 areas.

The line sensor 6f shown in FIG. 6 corresponds to that shown in FIG.
As shown in (A), five focus detection points 200 to 20 on the screen are displayed.
5 sets of line sensors CCD-L2, CCD-L1, CCD-C, CC as light receiving means for focus detection corresponding to 4
This is a known CCD line sensor composed of D-R1 and CCD-R2. The automatic focus detection circuit 103 A / D converts the voltage obtained from the line sensor 6f, and the CPU 1
Send to 00.

SW1 is a switch that is turned on by the first stroke of the release button 41 to start photometry, AF, etc., SW2 is a release switch that is turned on by the second stroke of the release button, and SW-AEL is the AE lock button 43. It is an AE lock switch that is turned on by. SW-DIAL
1 and SW-DIAL 2 are the electronic dial 4 already described.
5, a pulse signal generated here is input to an up / down counter of the signal input circuit 104, and is used to count the rotational click amount of the electronic dial 45.

SW-M1 to M4 are also dial switches provided in the mode dial 44 already described. The signals of these switches are input to the signal input circuit 104 and transmitted to the CPU 100 by the data bus.

The known LCD driver 105 is a known circuit for driving the liquid crystal display device LCD for display.
According to the signal from U100, the display of the aperture value, shutter speed, set shooting mode, etc. is simultaneously displayed on both the monitor LCD 42 and the in-finder LCD 42.

The LED drive circuit 106 is a lighting LE.
D (F-LED) 25 and LED2 for superimposing
1 is turned on and blinking is controlled. In addition, the LED drive circuit 10
6 has a circuit for driving the LED with a constant current. This constant current driving circuit is independent of the illumination LED (F-LED) 25 and the superimposing LED 21. The current value of the lighting LED (F-LED) 25 is fixed, but that of the superimposing LED is 0 m.
It is possible to select from A, 5 mA, and 40 mA. This current value can be set by the CPU 100 so that the current value for driving the superimposing LED 21 can be set, and the brightness can be controlled.

The shutter control circuit 108 controls the magnet MG-1 that runs the front curtain and the magnet MG-2 that runs the rear curtain when energized to expose the photosensitive member with a predetermined amount of light.

The motor control circuit 109 controls the motor M1 for winding and rewinding the film and the motor M2 for charging the main mirror 2 and the shutter 4.

A series of release sequences is performed by the shutter control circuit 108 and the motor control circuit 109.

FIGS. 7A and 7B show the monitor LCD 4
2 and the contents of all display segments of the LCD 24 in the finder.

In FIG. 7A, the fixed display segment portion 42a is provided with a known photographing mode display and the like. The 7-segment portion 42b for displaying variable numerical values includes a 4-digit 7-segment 62 for displaying shutter speed, a 2-digit 7-segment 63 for displaying an aperture value and a decimal point 64, and a limited numerical value displaying segment 65 for displaying the number of films. It consists of one-digit 7-segment 66.

In FIG. 7B, reference numeral 71 is a shake warning mark, 72 is an AE lock mark, 73, 74 and 75 are the same display segments as the shutter time display and the aperture value display, and 76 is an exposure correction setting mark. , 77 are strobe-filling marks, and 79 is a focusing mark indicating the focusing state of the taking lens.

Next, the operation of the camera having the above structure will be described with reference to the flow charts of FIGS.

When the mode dial 44 is rotated to set the camera from the inoperative state to the predetermined photographing mode (this embodiment will be described based on the case of setting the shutter display priority mode), the power of the camera is turned on. (Step # 1
00), the CPU 100 starts operation from step # 101 in FIG. [Step # 101] Flags required for camera control,
Initialize variables etc. This includes clearing the flag indicating that the shutter is being released (release flag). [Step # 102] Information on the operating member is input from the signal input circuit 104. Here, the change of the switch SW1 is also detected. The result of the detection of the change of the switch SW1 is held until the next step # 102 is executed. [Step # 103] It is determined whether or not the focus detection point selection button 90 is ON. If it is OFF, the process proceeds to step # 105, but if it is ON, the process proceeds to step # 104, where the subroutine " AF point setting ”is called.

The subroutine "range-finding point setting" sets whether the range-finding point is "arbitrary selection" input by the photographer or "automatic selection" in which the camera automatically sets the range-finding point.

In the case of "arbitrary selection", any one of the five distance measuring points is determined. First, the currently set focus detection point is displayed. In this state, the electronic dial 45
Is operated to automatically select a distance measuring point, a distance measuring point corresponding to the distance measuring point mark 200 (hereinafter referred to as a left distance measuring point), and a distance measuring point corresponding to a distance measuring point mark 201 (hereinafter, left middle). Distance measuring point), distance measuring point corresponding to the distance measuring point mark 202 (hereinafter referred to as central distance measuring point), distance measuring point corresponding to distance measuring point mark 203 (hereinafter referred to as right middle distance measuring point) ), AF point mark 2
Any of the focus detection points corresponding to 04 (hereinafter referred to as the right focus detection point) can be selected.

When the setting is completed, the focus detection point selection button 90 may be pressed (turned on) again. [Step # 105] It is determined whether or not the AF mode button 91 is ON, and if it is OFF, step # 107
If it is turned on, the process proceeds to step # 106, and the subroutine "AF mode setting" of step # 106 is called here.

In the subroutine "AF mode setting", one-shot AF or servo AF is set.

First, the currently set AF mode is displayed. By operating the electronic dial 45 in this state, either one-shot AF or servo AF can be selected. When finishing the setting,
The AF mode button 91 may be turned on again. [Step # 107] It is determined whether or not the release button 41 is pressed to turn on the switch SW1. If the switch SW1 is turned on, the process proceeds to step # 108. If the switch SW1 is turned off, the process returns to step # 102 and the measurement is performed. Distance selection button 90,
While checking the AF mode button 91, switch SW
Wait until 1 is turned on.

Then, the switch SW1 is turned on, and the operation shifts from step # 107 to step # 108. [Step # 108] The subroutine "photometry" is called. This subroutine "photometry" performs photometry calculation in which the selected focus detection points are weighted.

When the step # 108 is executed, the focus may not be detected yet, but in this case, the photometry calculation is performed by weighting the central focus detection point. The details of this subroutine "photometry" will be described later. [Step # 109] Here, step # 1 described above.
If it is detected in 02 that the state of the switch SW1 has changed from OFF to ON, step # 110
If the change is not detected, the process proceeds to step # 111. [Step # 110] Switch SW1 goes from OFF to O
Since it is N, it is the first focus detection operation, so
Before starting the distance measuring operation, an AF flag such as a focus flag is initialized. [Step # 111] A subroutine "focus detection" is called in order to detect the focus state of a plurality of focus detection points.

By calling this subroutine "focus detection", the defocus amount as a focus signal representing the focus state of each distance measuring point is obtained. [Step # 112] The subroutine "select distance measuring point" is called.

In this subroutine "focusing point selection", the subroutine "focus detection" executed in step # 111
Based on the defocus amounts of the plurality of focus detection points obtained by, the main subject is estimated and the focus detection points are determined. The defocus amount of the focus detection point obtained by this subroutine "selection of focus detection point" becomes the defocus amount actually used for lens control. [Step # 113] The subroutine "focus determination" is called.

In this subroutine "focus determination", the subroutine "distance measuring point selection" executed in step # 112 is executed.
Based on the defocus amount of the focus detection point obtained by the above, it is determined whether the current focus state is in focus, whether it is within the focus range, whether distance measurement is impossible, or the like. This determination result is used for control for driving the lens, display, and the like. [Step # 114] One-shot AF or servo AF
If it is one-shot AF, step # 11
5. If it is the servo AF, the process proceeds to step # 120.

Here, it is assumed that the one-shot AF is selected and the operation is moved from step # 114 to step # 115. [Step # 115] It is determined whether or not the distance measurement (focus detection) is impossible, and if the distance measurement is impossible, the process proceeds to step # 117 to display this. [Step # 116] The CPU 100 sends a signal to the LCD drive circuit 105 to blink the focus mark 79 on the in-viewfinder LCD 24 to notify the photographer that distance measurement is impossible.

If it is determined in step # 115 that distance measurement is possible, the process proceeds to step # 117. [Step # 117] It is determined whether or not the focus state of the focus detection point selected in step # 112 is in focus, and if it is in focus, the process proceeds to step # 118 to perform focus display. [Step # 118] The CPU 100 sends a signal to the LCD drive circuit 105 to turn on the focus mark 79 of the in-viewfinder LCD 24 to notify the photographer of the focus.

If it is determined in step # 117 that the lens is out of focus, the process proceeds to step # 119 to drive the lens. [Step # 119] The CPU 100 sends a signal to the lens focus adjustment circuit 110 to drive the taking lens 1 by a predetermined amount.

If it is determined in step # 114 that the servo AF is selected, the process proceeds to step # 120. [Step # 120] Here, the above step # 112.
It is determined whether or not the focus state of the focus detection point selected in step 7 is within the in-focus range, and if it is within the in-focus range, the lens is not driven and the process immediately proceeds to step # 122. On the other hand, if the focus is out of the range, the process proceeds to step # 121 to drive the lens. [Step # 121] The CPU 100 sends a signal to the lens focus adjustment circuit 110 to drive the taking lens 1 by a predetermined amount.

Steps # 116, # 118, # 11
9 or when the operation of step # 121 is completed, the process proceeds to step # 122. [Step # 122] Call the subroutine "distance measuring point display".

In this subroutine “distance measuring point display”,
The distance measuring point is displayed except during the release control. Details of the subroutine " distance measuring point display " will be described later.

The following steps # 123, # 124, # 1
25 is a process for determining whether or not to perform the release sequence. [Step # 123] If it is the one-shot AF, the release cannot be performed unless the focus is achieved, so it is necessary to determine the focus. Therefore, first, here, it is determined whether the one-shot AF or the servo AF. As a result, if it is the one-shot AF, the process proceeds to step # 124 in order to determine the focus. On the other hand, if the servo AF,
Since it is not necessary to determine the focus, the process immediately proceeds to step # 125. [Step # 124] During the one-shot AF, the release must be done without focusing as described above. Therefore, the state of the focusing flag (set to 1 when the in-focus is determined by the subroutine of # 113) If it is in focus, the process proceeds to step # 125, and if it is not in focus, the process returns to step # 102 in FIG.

As described above, if the one-shot AF is selected and the focus flag is set (focus flag = 1), the operation moves from step # 124 to step # 125. [Step # 125] It is determined whether or not the switch SW1 is ON, and if it is ON, step # 126
If it is turned off, step # 102 in FIG.
Return to. [Step # 126] It is determined whether or not the switch SW2 is ON, and if it is ON, step # 127
And the release sequence described later is executed.
If the switch SW2 is off, the process returns to step # 102 in FIG.

Next, the release sequence is shown in FIG.
Description will be given according to the flowcharts of FIGS. [Step # 200] Release control is started. [Step # 201] As a preparation for exposing the film 5 to light, first, the main mirror 2 is raised.

For this purpose, the CPU 100 sends a signal to the motor control circuit 109 to start driving the motor M2. [Step # 202] When energization of the motor M2 is started, a rush current flows. In order to prevent the rush current and the driving of the diaphragm 31 performed in the next step # 203 from overlapping, the diaphragm 3 is started from the start of energization of the motor M2.
Wait 10 ms before starting the driving of 1. [Step # 203] A signal is sent to the diaphragm driving device 32 including the diaphragm driving circuit 11 to narrow down the diaphragm 31 by a predetermined amount. [Step # 204] Phase signal C of a phase substrate (not shown)
Continue monitoring MSP1 and CMSP2, and wait until the phase signal reaches the mirror-up position. [Step # 205] Since the mirror-up position is reached, a signal is sent to the motor control circuit 109 to cause the motor M to move.
Stop the energization of 2. [Step # 206] Wait until the aperture 31 is narrowed down by a predetermined amount. [Step # 207] Shutter control is performed. First, C
The PU 100 sends a signal to the shutter control circuit 108 to energize the magnet MG1 and open the front curtain of the shutter 4. The aperture value of the aperture 31 and the shutter speed of the shutter 4 are determined from the exposure value detected by the photometric circuit 102 and the sensitivity of the film 5. After a lapse of a predetermined shutter time, a signal is sent to the shutter control circuit 108, the magnet MG2 is energized, and the rear curtain of the shutter 4 is closed.
This completes the exposure of the film 5.

When the exposure of the film 5 is completed, the film 5 is wound, the mirror is down, and the shutter is charged.

The film 5 is wound up by the motor M1, and the mirror down and shutter charge are carried out by the motor M2.
Done by The winding of the film 5 is controlled by monitoring the signals FILM1 and FILM2 of the phase substrate (not shown) and driving the motor M1 until the winding complete position is reached. In addition, control of mirror down and shutter charge is performed by the signal CMS of the phase substrate (not shown).
This is performed by monitoring P1 and CMSP2 and driving the motor M2 until the shutter charge completion position is reached.

These controls are actually performed by using interrupt processing. This interrupt occurs every 1ms, and 1ms
The above-mentioned processing is performed every time. Details will be described later. [Step # 208] Here, preparation for starting the above-mentioned interrupt, that is, permission of the interrupt and setting of the timer (1 ms) for generating the interrupt are performed. In step # 208, mirror down and shutter charge are performed by reenergizing the motor M2.

For this reason, a signal is sent to the motor control circuit 109 to energize the motor M2, and the above-mentioned 1 ms is passed.
The process is performed such that the interrupt flag is generated every time, the control flag related to shutter charge is initialized, the shutter charge flag is set to 1, and the like. [Step # 209] A rush current flows when energization of the motor M2 is started. In order not to overlap the rush current and the energization of the motor M1 for winding the film 5 at the next step # 210, the motor M1
10 from the start of energization of 2 to the start of driving of the motor M1
Wait for ms. [Step # 210] The film M is wound by the motor M.
This is done by driving 1.

Therefore, a signal is sent to the motor control circuit 109 to energize the motor M1 and the above-mentioned 1 ms
Used for interrupt processing that occurs each time, initialization of control flags related to film winding, film winding flag set to 1, and the like are performed together. [Step # 211] Here, a rush current flows when the energization of the motor M1 is started. In order to prevent the rush current and the driving of the diaphragm 31 performed in the next step # 212 from overlapping, it is necessary to wait 10 ms from the start of energization of the motor M1 until the driving of the diaphragm 31 is started. [Step # 212] A signal is sent to the diaphragm driving device 32 including the diaphragm driving circuit 111 to start driving the diaphragm 31. This is done to return the aperture to full aperture. [Step # 213] The shutter charging flag is 0.
Until, that is, until the shutter charge is completed. When the shutter charge is completed, the main mirror 2 is also in the down state. [Step # 214] Wait until the aperture 31 returns to the open position. When the shutter charge is completed (the main mirror 2 is also in the down state) and the diaphragm 31 is in the open state, the metering and the AF are possible. [Step # 215] Servo AF or One-shot AF
If it is the one-shot AF, the photometry and distance measurement are not performed during the continuous shooting, so that the process proceeds to step # 223 in FIG. On the other hand, in the case of servo AF, photometry and distance measurement are performed even during continuous shooting, so the flow shifts to step # 216.

Here, assuming that the servo AF is performed,
It is assumed that the process proceeds to step # 216. [Step # 216] In servo AF, a subroutine "focus detection" is called because distance measurement is performed even during continuous shooting.

By calling this subroutine "focus detection", the defocus amount of each distance measuring point is obtained. [Step # 217] Call the subroutine "distance measuring point selection".

In this subroutine "focus detection point selection", the main subject is estimated based on the defocus amounts of a plurality of focus detection points obtained by the subroutine "focus detection" executed in step # 216, A process for determining a focus detection point is performed. The defocus amount of the focus detection point obtained by this subroutine "selection of focus detection point" becomes the defocus amount actually used for lens control. [Step # 218] The subroutine "focus determination" is called.

In this subroutine "focus determination", based on the defocus amount of the focus detection point obtained by the subroutine "selection of focus detection point" executed in step # 217,
It is determined whether or not the current focus state is in focus, whether it is in the focus range, whether distance measurement is impossible, or the like. This determination result is used for control, display, etc. for driving the lens. [Step # 219] The subroutine "display of distance measuring points" is called.

This subroutine "display of distance measuring point" is for notifying the photographer of the distance measuring point currently selected even during continuous shooting. The details of this subroutine "distance measuring point display" will be described later. [Step # 220] It is determined whether or not the focus state of the focus detection point obtained in step # 218 is within the in-focus range, and if it is out of the in-focus range, the lens driving is performed in step # 220.
Proceed to 221. [Step # 221] The CPU 100 sends a signal to the lens focus adjustment circuit 110 to drive the photographic lens 1 by a predetermined amount.

If it is determined in step # 220 that the lens is within the in-focus range, or if the lens driving is completed in step # 221, the process proceeds to step # 222. [Step # 222] The subroutine "photometry" is called. The subroutine "photometry" weights the selected focus detection points and performs photometry calculation. The details of this subroutine "photometry" will be described later.

If it is determined in step # 215 that the one-shot AF is selected, or after the subroutine "photometry" is completed in step # 222, the process proceeds to step # 223. [Step # 223] Wait until the film winding flag becomes 0, that is, until the film 5 is wound by one frame. When the winding of the film 5 is completed, it is determined in step # 224 whether or not the release operation is continued.
Move to. [Step # 224] It is determined whether or not the release button 41 is pressed and the switch SW2 is turned on. If the switch SW2 is turned on, the process returns to step # 201 of FIG. 11 to continue the release operation. ,on the other hand,
If the switch SW2 is off, the release operation is terminated and the process returns to step # 102 in FIG.

Next, the interrupt processing for controlling film winding and shutter charge will be described with reference to the flowchart of FIG. [Step # 300] Timer for interrupt generation (1 m
When s) elapses, an interrupt occurs, and step # 301
Interrupt control from. [Step # 301] In order to generate an interrupt again 1 ms later, the interrupt generation timer (1 ms) is reset. [Step # 302] The shutter charging flag is checked, and if shutter charging is in progress, the process proceeds to step # 303, and if not, the process proceeds to step # 305. [Step # 303] Signal CMS of the phase board (not shown)
By monitoring P1 and CMSP2, it is determined whether or not the shutter charge is at the completed position. If the shutter charge is not yet completed, the process proceeds to step # 305, and if the shutter charge is completed, Go to step # 304. [Step # 304] Since the shutter charge is completed, a signal is sent to the motor control circuit 109 to stop the motor M2, the shutter charge flag is cleared, and the completion of the shutter charge control is stored. [Step # 305] The film drive (winding) flag is determined, and if the film is being wound, step # 30.
Go to step 6, and if the film is not being wound, step #
Move to 308. [Step # 306] Signal FIL of the phase board (not shown)
By monitoring M1 and FILM2, it is determined whether or not the winding for one frame is completed, and if the winding is not completed yet, the process proceeds to step # 308 and the winding is completed. If so, the process proceeds to step # 307. [Step # 307] Since the winding of one frame is completed,
A signal is sent to the motor control circuit 109 to stop the motor M1 and the film winding flag is cleared to store that the film winding control is completed. [Step # 308] It is determined whether or not the shutter charge control and the film winding control are both ended. If the control is still underway, the process proceeds to step # 310, and if the control is completed for both, the process proceeds to step # 309. To do. [Step # 309] Since the film winding control and the shutter charge control are both finished and it is no longer necessary to generate an interrupt, the interrupt is prohibited. [Step # 310] The interrupt process ends.

The operation of the camera having the focus detecting means has been described above.

Next, the above-mentioned subroutine "focus detection" will be described with reference to the flowchart of FIG. This subroutine "focus detection" performs processing such as sensor accumulation operation, image signal reading, and defocus amount calculation. [Step # 400] When the subroutine "focus detection" is called, the CPU 100 performs the following control from step # 401. [Step # 401] One-shot AF or Servo AF
If it is servo AF, the process proceeds to step # 403, and if it is one-shot AF, the process proceeds to step # 402. [Step # 402] The focus flag is checked to determine whether or not the current focus state of the taking lens 1 is in focus. If in focus, the process proceeds to step # 410. If it is not in focus, the process proceeds to step # 403.

If it is the one-shot AF and the focus is achieved by the above steps # 401 and # 402, the focus detection is not executed. That is, this subroutine "focus detection" is immediately returned. [Step # 403] It is determined whether the setting state of the focus detection points is the focus detection point automatic selection or the arbitrary selection. If the focus detection point automatic selection is selected, the process proceeds to step # 405, and if the focus detection points are selected, the process proceeds to step # 404. Transition.

First, an optional case will be described. [Step # 404] Since it is an arbitrary selection, the focus detection point designated by the photographer is set as the calculation focus detection point. The arithmetic focus detection point is a focus detection point for performing sensor accumulation control, image signal reading, and defocus amount calculation.

Next, the case of automatic selection of distance measuring points will be described. [Step # 405] Since the focus detection points are automatically selected,
Since the camera automatically selects focus detection points by estimating the main subject, it is necessary to calculate all focus detection points. Therefore, all the distance measuring points are set as the calculation distance measuring points.

After the calculation distance measuring point is determined as described above, the process proceeds to step # 406. [Step # 406] The accumulation operation of the line sensor 6f is started. Here, the accumulation operation is started for all the sensor regions corresponding to all the distance measuring points, regardless of the above-described calculated distance measuring points. [Step # 407] The process waits until the accumulation operation of all the sensor areas corresponding to the above calculation distance measuring points is completed. [Step # 408] When the accumulation operation of all the sensor areas of the calculation distance measuring point described above is completed, the accumulation signal of the sensor area corresponding to the calculation distance measuring point is read out. [Step # 409] When the reading operation of the accumulated signals of all the sensor areas of the calculation distance measuring point is completed, the defocus amount corresponding to the calculation distance measuring point is calculated. Also,
In this step, it is also determined whether or not each distance measuring point cannot be measured. [Step # 410] The subroutine "focus detection" is completed and the process returns.

Next, the subroutine "selection of distance measuring points" will be described with reference to the flowchart of FIG.

The subroutine "focus detection point selection" estimates the main subject based on the defocus amount of each focus detection point,
A process of selecting the distance measuring point is performed. [Step # 500] When the subroutine "select distance measuring point" is called, the CPU 100 executes the following control from step # 501. [Step # 501] It is determined whether the focus detection points are automatically selected or arbitrarily selected. If the focus detection points are arbitrary, the process proceeds to step # 502 to set the focus detection points set by the photographer to the selected focus detection points. If the distance point is automatically selected, the process proceeds to step # 503.

First, an optional case will be described. [Step # 502] Since it is the time of arbitrary selection, the focus detection point set by the photographer is set as the selected focus detection point, and the flow advances to step # 514.

Next, at the time of automatic selection of focus detection points, the processing from step # 503 is executed in order to estimate the main subject from the defocus amount of each focus detection point. [Step # 503] It is determined whether or not there is a distance measuring point that can be measured out of the five distance measuring points, and if none of the distance measuring points can be measured, step # is performed to select the central distance measuring point. If there is a distance measuring point where the distance can be measured, the process proceeds to step # 504.

Here, it is assumed that there is a distance measuring point at which the distance can be measured, and the process proceeds to step # 504. [Step # 504] It is determined whether or not there is one distance measuring point, and if there is one, the process proceeds to step # 512 to select that distance measuring point, and distance measuring is possible. 2 points
If the number is one or more, the process proceeds to step # 505.

First, it is assumed that there are two or more distance measuring points capable of distance measurement. [Step # 505] It is determined whether or not there is a central distance measuring point among the distance measuring points capable of distance measurement. If the central distance measuring point is present, the process proceeds to step # 506, and if there is no central distance measuring point, the step is performed. #
Move to 507. [Step # 506] Here, it is determined whether or not the central focus detection point is at a short distance (for example, 20 times or less of the focal length). If it is at a short distance, the process proceeds to step # 507, and if it is not at a short distance. Go to step # 510.

If the distance measuring point capable of distance measurement is the central distance measuring point and the distance is short, or if the distance measuring at the central distance measuring point is impossible, the operation proceeds to step # 507. [Step # 507] It is determined whether or not the number of short-distance focus points is greater than the number of long-distance focus points, and if there is more, it is determined that the main subject is on the photographer side, and If the number of short-distance focus points is small, the main subject is judged to be on the far-distance side, and the long-distance depth is considered in consideration of the depth of field. The process proceeds to step # 512 in order to select the closest point among the distance measuring points. [Step # 508] Since the number of short-distance focus points is larger than the number of long-distance focus points, the most recent point is selected as the selected focus point, and the process proceeds to step # 514. [Step # 509] Since the number of short-distance focus points is small, the closest focus distance point in the long distance is set as the selected focus point, and the process proceeds to step # 514.

If the central distance measuring point is not a short distance in the above step # 506, this step # 506 is executed as described above.
Move to 510. [Step # 510] It is determined whether or not the number of long-distance focus points is larger than the number of short-distance focus points, and if there is more, it is determined that the subject is on the far-distance side including the central focus point. , The process proceeds to step # 511 to select the central distance measuring point, while if the number of long distance distance measuring points is small, the process proceeds to step # 508 to select the closest distance measuring point as described above. [Step # 511] Since the number of long-distance focus points is larger than the number of short-distance focus points, here, the central focus point is selected as the selected focus point, and the process proceeds to step # 514.

Next, the case where there is only one focus detection point in step # 504 will be described. In this case, the process proceeds to step # 512 as described above. [Step # 512] Here, the distance measuring point capable of distance measurement is set as the selected distance measuring point, and the process proceeds to step # 514.

If none of the five distance measuring points can be measured in step # 503, the process proceeds to step # 513 as described above. [Step # 513] Here, the central focus detection point is set as the selected focus detection point, and the process proceeds to step # 514. [Step # 514] The subroutine "distance measuring point selection" is ended, and the process returns to the main routine.

Next, the subroutine "photometry" will be described with reference to the flowchart of FIG.

The subroutine "photometry" means the photometric sensor 10
And the photometric circuit 102 are used to measure the brightness of each area within the shooting range. Then, from the brightness of each area and the selected distance measuring point, a photometric value is calculated by an arithmetic expression weighted to the selected distance measuring point, and an exposure amount correction amount for correcting the exposure amount according to the light ray state is set. Then, the exposure amount is calculated from the photometric value and the exposure amount correction amount.

Here, an arithmetic expression in which the selected distance measuring points are weighted will be described.

First, the luminance of the entire area within the photographing range is measured. The brightness information of each area is SA0 for area A0 and area A1.
Is SA1, area A2 is SA2, area A3 is SA3, area A4 is SA4, area B5 is SB5, area B6 is SB6,
Area B7 is SB7, area B8 is SB8, area B9 is SB
9, area B10 is SB10, area B11 is SB11, area C12 is SC12, area C13 is SC13, area C1
4 is SC14, and area C15 is SC15.

Next, the brightness of the area of the main subject, that is, the area of the selected focus detection point is BVSA, and the brightness of the area adjacent to the selected focus detection point vertically and horizontally is BVSB1, BVS.
B2, BVSB3, and the sum of the luminance in all areas within the shooting range is BVSUM. In addition, the area of the focus detection point selected from the entire area within the shooting range and the area that is vertically and horizontally adjacent to the selected focus detection point are deleted, that is, the brightness of the background area is selected as BVSC. Among the brightnesses BVSB1, BVSB2, and BVSB3 of the areas adjacent to the distance measuring point vertically and horizontally, the one having the highest brightness is BVSB. Then, an average value is obtained by weighting the selected distance measuring points as shown in the equation (1) below.

BV = {(3 (BVSA) + BVSB1 + BVSB2 + BVSB3 + BVSUM) / 22} ... (1) Then, from the above-mentioned BVSA, BVSB, BVSC,
The exposure amount correction amount ALPHA at the time of backlighting is obtained, and the BV value is calculated according to the following equation (2).

BV = {(3 (BVSA) + BVSB1 + BVSB2 + BVSB3 + BVSUM) / 22} + ALPHA (2) In this way, the main subject is emphasized and the calculation is performed in consideration of the backlit scene to obtain the exposure amount. [Step # 600] When the subroutine "photometry" is called, the CPU 100 performs the following processes from step # 601. [Step # 601] Photometric circuit 102 and photometric sensor 1
0 is used to obtain the luminance information of the entire area within the shooting range. [Step # 602] The sum of the brightness information of all the areas within the shooting range is obtained, and this is set as BVSUM. [Step # 603] An average value is obtained from the brightness information of all areas within the shooting range, and this is set as BVAVE. [Step # 604] The subroutine "AB calculation" is called.

In this subroutine "AB calculation", the brightness BVSA of the area of the selected focus detection point, the brightness BVSB1 of the area vertically and horizontally adjacent to the selected focus detection point described above.
The maximum value BVSB among the brightnesses of BVSB2, BVSB3, and the selected vertically and horizontally adjacent areas is calculated. The details of this subroutine "AB calculation" will be described later. [Step # 605] The subroutine "C operation" is called.

In this subroutine "C operation", the brightness BVSC of the background portion is obtained. This subroutine "C operation"
Details of will be described later. [Step # 606] The subroutine "exposure amount correction amount calculation" is called.

In this subroutine "exposure amount correction amount calculation", the backlight correction value ALPHA is obtained. The details of this subroutine "exposure amount correction amount calculation" will be described later. [Step # 607] Subroutine "Calculation of BV value"
To call.

In this subroutine "calculation of BV value",
The BV value is calculated from the information obtained in steps # 601 to # 606. Details of this subroutine "calculation of BV value" will be described later. [Step # 608] Exposure calculation is performed based on the photometric value calculated in step # 607, and the EV value is obtained from the photometric value and film sensitivity. [Step # 609] The aperture value and the shutter speed are calculated from the EV value calculated in step # 608. [Step # 610] The subroutine "photometry" is terminated, and the process returns to the main routine.

Next, the above subroutine "AB calculation" will be described with reference to the flowcharts of FIGS.

This subroutine "AB calculation" is performed by the brightness BVSA of the area of the selected focus area and the brightness BVSB1, BVSB of the areas vertically and horizontally adjacent to the selected focus area.
2, BVSB3, a process for obtaining the highest brightness BVSB in the region vertically and horizontally adjacent to the selected focus detection point, which is used when obtaining the backlight correction value. [Step # 700] When the subroutine "AB operation" is called, the CPU 100 performs the following processes from step # 701. [Step # 701] Although the change of the switch SW1 is detected in the above step # 102, when the change of the switch SW1 is detected to be changed from OFF to ON, the first photometry operation is performed. Can be recognized.
Here, it is determined whether the current photometry operation is the first photometry operation, and if it is the first photometry operation, step # 708.
Otherwise, to step # 702.

At the time of the first photometry operation, since the focus detection operation is not yet performed, the selected focus detection point is not obtained. At this time, since the central focus detection point is regarded as the selected focus detection point for calculation, the process proceeds to step # 708 as described above.

If the focus detection operation is performed at least once, the process proceeds to step # 702. [Step # 702] As a result of the focus detection operation, if all the focus detection points cannot be measured, the process proceeds to step # 708, and if at least one focus detection point can measure the distance, step # 7.
Move to 03.

When all the focus detection points cannot be measured, the selected focus detection point cannot be obtained . At this time, since the central focus detection point is regarded as the selected focus detection point for calculation, the process proceeds to step # 708 as described above.

At least 1 is set in the following step # 703.
It advances when two focus points can be measured. [Step # 703] It is determined whether or not the selected focus detection point is the central focus detection point. When the central focus detection point is selected, the process proceeds to step # 708, and a focus detection point other than the central focus detection point is selected. If so, the process proceeds to step # 704. [Step # 704] It is determined whether or not the selected focus detection point is the left focus detection point, and if the left focus detection point is selected, the process proceeds to step # 711, and other than the left focus detection point is selected. If so, the process proceeds to step # 705. [Step # 705] It is determined whether or not the selected focus detection point is the left inner focus detection point, and if the left inner focus detection point is selected, the process proceeds to step # 709, except for the left inner focus detection point. If is selected, the process proceeds to step # 706. [Step # 706] It is determined whether or not the selected focus detection point is the right inner focus detection point. When the right inner focus detection point is selected, the process proceeds to step # 710, and other than the right inner focus detection point. If is selected, the process proceeds to step # 707.

The following step # 707 is performed when the right focus detection point is selected. [Step # 707] The brightness BVSA of the area of the selected focus area and the brightness BVSB1, BVSB2, BVSB3 of the areas vertically and horizontally adjacent to the selected focus area are set as follows.

BVSA = Brightness SA3 in the area A4 BVB1 = Brightness SA2 in the area A2 BVB2 = Brightness SB10 in the area B10 BVB3 = Brightness SB11 in the area B11 The following steps # 708 come when the central focus detection point is selected. . [Step # 708] The brightness BVSA of the area of the selected focus detection area and the brightness BVSB1, BVSB2, BVSB3 of the areas adjacent to the selected focus detection area vertically and horizontally are set as follows.

BVSA = Brightness SA0 of area A0 BVB1 = Brightness SA1 of area A1 BVB2 = Brightness SA2 of area A2 BVB3 = Brightness SB5 of area B5 The following steps # 709 proceed when the left inner AF point is selected. come. [Step # 709] The brightness BVSA of the area of the selected focus detection point and the brightness BVSB1, BVSB2, BVSB3 of the areas adjacent to the selected focus detection point vertically and horizontally are set as follows.

BVSA = Brightness SA1 in the area A1 BVB1 = Brightness SA0 in the area A0 BVB2 = Brightness SA3 in the area A3 BVB3 = Brightness SB6 in the area B6 The following steps # 710 proceed when the right inner focus point is selected. come. [Step # 710] The brightness BVSA of the area of the selected focus detection point and the brightness BVSB1, BVSB2, BVSB3 of the areas adjacent to the selected focus detection area vertically and horizontally are set as follows.

BVSA = Brightness SA2 of the area A2 BVB1 = Brightness SA0 of the area A0 BVB2 = Brightness SA4 of the area A4 BVB3 = Brightness SB7 of the area B7 The following steps # 711 come when the left focus area is selected. . [Step # 711] The brightness BVSA of the area of the selected focus area and the brightness BVSB1, BVSB2, BVSB3 of the areas adjacent to the selected focus area vertically and horizontally are set as follows.

BVSA = Brightness SA3 in the area A3 BVB1 = Brightness SA1 in the area A1 BVB2 = Brightness SB8 in the area B8 BVB3 = Brightness SB9 in the area B9 In the next step # 712 and below, the backlight correction value ALPHA
The maximum value BVSB among the brightnesses BVSB1, BVSB2, BVSB3 of the areas vertically and horizontally adjacent to the selected distance measuring point used when calculating [Step # 712] Here, assume that BVSB is BV.
SB1. [Steps # 713, # 714] BVSB and BVSB
When 2 is compared (step # 713) and BVSB2 is larger, BVSB is changed to BVSB2 (step # 714). [Steps # 715, # 716] BVSB and BVSB
3 is compared (step # 715), and if BVSB3 is larger, BVSB is changed to BVSB3 (step # 716). [Step # 717] The subroutine "AB calculation" is completed and the process returns.

Next, regarding the subroutine "C operation",
A description will be given according to the flowchart of FIG.

This subroutine "C operation" is a process for obtaining the brightness information BVSC of the background area. A region obtained by deleting the region of the selected focus detection point and the regions vertically and horizontally adjacent to the focus detection point from all the regions within the shooting range is regarded as the background portion, and the brightness of this background portion is set to BVSC. BVSC is luminance information used when obtaining the backlight correction value ALPHA. [Step # 800] When the subroutine "C operation" is called, the CPU 100 performs the following processes from step # 801. [Step # 801] The brightness BVSC of the background portion is calculated according to the following equation (3).

BVSC = (BVSUM−BVSA−BVSB1−BVSB2−BVSB3) / 12 (3) As described above, the area of the selected focus area and the focus area thereof are selected from the entire area within the shooting range. The average value of the brightness of the area (area 12) in which the areas adjacent to each other in the vertical and horizontal directions are deleted is the brightness BVSC of the background portion. [Step # 802] The subroutine "C operation" is completed and the process returns.

Next, the subroutine "correction amount calculation" will be described.

This subroutine "exposure amount correction amount calculation"
Performs processing for obtaining the exposure correction amount APLHA.

First, how to obtain the exposure correction amount will be described.

To obtain the exposure correction amount, three pieces of information, that is, the luminance of the main subject, the luminance of the surroundings of the main subject, and the luminance of the background are used. From these three pieces of information, the brightness difference between the brightness of the main subject and the brightness around the main subject and the brightness difference between the brightness of the background part and the brightness around the main subject are obtained, and the exposure amount is corrected according to the degree of each brightness difference. Find the amount.

In the first embodiment of the present invention, the brightness BVSA of the area of the selected focus detection point is the brightness of the main subject, and the brightness BVSB of the area vertically and horizontally adjacent to the selected focus detection point.
1, BVSB2, BVSB3, the brightness B showing the maximum value
The brightness difference BVBA between the brightness of the main subject and the brightness of the surroundings of the main subject is obtained by the following equation (4), where VSB is the brightness around the main subject.

BVBA = BVSB−BVSA (4) Further, the area of the selected focus detection area and the area adjacent to the selected focus detection area vertically and horizontally are deleted from the entire area within the shooting range. With the average value BVSC of the brightness of the selected area as the background brightness, the brightness difference B between the background brightness and the surrounding brightness of the main subject
VCB is calculated by the following equation (5).

BVCB = BVSC−BVSB (5) Basically, the exposure correction amount is determined by the BVBA level and the BVCB level described above.

However, if the exposure amount correction amount is determined from the two factors of the BVBA level and the BVCB level, if the BVBA level and the BVCB level are the same, it is the same whether the background is dark or bright. Since the exposure amount is the correction amount, a proper exposure amount correction amount cannot be obtained. Therefore, in the first embodiment of the present invention, the background brightness BVSC
Depending on the height of the
As shown in FIGS. 21 to 23, 3 depending on the brightness of the background portion.
Prepared the pattern.

FIG. 21 is a pattern of exposure amount correction amount when BVSC is BV8 or more , and FIG. 22 is BVSC BV4.
The pattern of the exposure amount correction amount when it is equal to or more than BV8, and FIG.
Is a pattern of exposure amount correction amount when BVSC is less than BV4 .

Next, the subroutine "exposure amount correction amount calculation" is actually executed according to the flow charts of FIGS.
I will explain. [Step # 900] When the subroutine "exposure amount correction amount calculation" is called, the CPU 100 returns to step # 90.
The following processing is performed from 1. [Step # 901] Difference between the brightness of the area of the selected focus detection area and the brightness of the area adjacent to the selected focus detection point BVBA
Is calculated by the above equation (4). [Step # 902] The difference BVBA between the brightness of the background portion and the brightness of the area adjacent to the selected focus detection point is calculated by the above equation (5).

In steps # 903 and # 904 below, the brightness of the background portion is determined in order to change the backlight correction value obtained depending on the brightness of the background portion. [Step # 903] The background brightness BVSC is BV8.
If it is BV8 or more, the process proceeds to step # 920 in FIG. 25 to obtain the exposure amount correction amount according to the exposure amount correction amount pattern in the case of high brightness.
If it is less than this, the process proceeds to step # 904.

First, the case where the background brightness BVSC is less than BV8 will be described. [Step # 904] The background brightness BCSC is BV4.
If it is BV4 or more, the process proceeds to step # 940 in FIG. 26 in order to obtain the exposure amount correction amount according to the exposure amount correction amount pattern for medium brightness, and BV4
If it is less than this, the process proceeds to step # 905.

Here, the background brightness BCSC is BV.
It shall be less than 4. [Step # 905] The exposure correction amount APLHA is temporarily set to +1.0. [Step # 906] Here, the exposure correction amount ALP
Determine whether or not the condition for HA to be +1.0 is met. This determination is made when BVCB is -1.0 stage or more and BVBA is +2.0 stage or more. If this condition is satisfied, the process proceeds to step # 950 in FIG. 27 to set the exposure amount correction amount ALPHA to +1.0 step. If this condition is not satisfied, step # 9 is performed to make the next determination.
Move to 07. [Step # 907] Temporarily set the exposure correction amount APLHA to +0.5 steps. [Step # 908] Here, the exposure amount correction amount ALP
Determine whether or not the condition to set HA to +0.5 is met. This determination is made when the BVCB is -1.5 or more and the BVBA is +1.0 or more. If this condition is satisfied, the process proceeds to step # 950 in FIG. 27 to set the exposure amount correction amount ALPHA to +0.5 step. If this condition is not satisfied, the exposure amount correction amount ALPHA is set to 0. Move to # 909. [Step # 909] The exposure amount correction amount ALPHA is set to 0, and the process proceeds to step # 950 in FIG.

If the background portion has a high luminance of BV8 or higher in step # 903, as described above,
The process moves from step # 903 to step # 920 in FIG. [Step # 920] Temporarily set the exposure correction amount APLHA to +1.5 steps. [Step # 921] Here, the exposure amount correction amount ALP
Determine whether or not the conditions for HA +1.5 stage are met. This determination is made when BVCB is -0.5 stage or higher and BVBA is +2.0 stage or higher. If this condition is satisfied, the process proceeds to step # 950 in FIG. 27 to set the exposure amount correction amount ALPHA to +1.5 steps. If this condition is not satisfied, step # 9 is performed to make the next determination.
Move to 22. [Step # 922] The exposure amount correction amount APLHA is temporarily set to +1.0. [Step # 923] Here, the exposure amount correction amount ALP
Determine whether or not the condition for HA to be +1.0 is met. This determination is made when BVCB is -1.0 stage or more and BVBA is +1.5 stage or more. If this condition is satisfied, the process proceeds to step # 950 in FIG. 27 to set the exposure amount correction amount ALPHA to +1.0 step. If this condition is not satisfied, step # 92 is performed to make the next determination.
Go to 4. [Step # 924] Temporarily set the exposure correction amount APLHA to +0.5 steps. [Steps # 925, # 926] Here, it is determined whether or not the condition for setting the exposure amount correction amount ALPHA at +0.5 is satisfied. This determination is made when the BVBA is +1.0 stage or more or the BVCB is -1.5 stage or less.
If this condition is satisfied, the process proceeds to step # 950 in FIG. 27 to set the exposure amount correction amount ALPHA to +0.5 step,
If this condition is not satisfied, the process proceeds to step # 927 to set the exposure amount correction amount to 0. [Step # 927] The exposure amount correction amount ALPHA is set to 0, and the process proceeds to step # 950 in FIG.

If the brightness of the background portion is medium brightness of BV4 or more (less than BV8) in step # 904 of FIG. 24, the process shifts from step # 904 to step # 940 of FIG. 26 as described above. [Step # 940] Temporarily set the exposure correction amount APLHA to +1.5 steps. [Step # 941] Here, the exposure amount correction amount ALP
Determine whether or not the conditions for HA +1.5 stage are met. This determination is made when BVCB is -0.5 stage or more and BVBA is +2.5 stage or more. If this condition is satisfied, the process proceeds to step # 950 in FIG. 27 to set the exposure amount correction amount ALPHA to +1.5 steps. If this condition is not satisfied, step # 9 is performed to make the next determination.
Move to 42. [Step # 942] The exposure amount correction amount APLHA is temporarily set to +1.0. [Step # 943] Here, the exposure amount correction amount ALP
Determine whether or not the condition for HA to be +1.0 is met. This determination is made when BVCB is -1.0 stage or more and BVBA is +1.0 stage or more. If this condition is satisfied, the process proceeds to step # 950 in FIG. 27 to set the exposure amount correction amount ALPHA to +1.0 step. If this condition is not satisfied, step # 9 is performed to make the next determination.
Go to 44. [Step # 944] Temporarily set the exposure correction amount APLHA to +0.5 steps. [Step # 945] Here, the exposure correction amount ALP
Determine whether or not the condition to set HA to +0.5 is met. This determination is made when the BVBA is +0.5 stage or more. If this condition is satisfied, the exposure amount correction amount AL
The process proceeds to step # 950 in FIG. 27 to set the PHA to +0.5 stage, and if this condition is not satisfied, the process proceeds to step # 947 to set the backlight correction value to 0. [Step # 946] The exposure amount correction amount ALPHA is set to 0, and the process proceeds to step # 950 in FIG.

When the process proceeds to the next step # 950, the exposure amount correction amount ALPHA is obtained. The steps after this step are the operation parts related to the storage means and the correction means in the present invention. [Step # 950] Whether or not this photometric operation is the first photometric operation is determined, and if the photometric operation is the first photometric operation, the obtained exposure amount correction amount ALPHA should be used as it is.
8 is moved to step # 962, and if it is not the first photometric operation, the process proceeds to step # 951. [Step # 951] It is determined whether or not the photometric operation is in continuous shooting. If not, the process proceeds to step # 962 in FIG. 28 to use the obtained exposure amount correction amount ALPHA as it is. If you are shooting continuously, step #
Move to 952.

As described in the release sequence above, in the case of one-shot AF, metering is not performed during continuous shooting.
In the case of one-shot AF, the exposure amount is determined at the time of focusing. Therefore, the photometry operation during continuous shooting is limited to the servo AF. By the above steps # 950 and # 951, the correction means for correcting the exposure correction amount of the present invention functions only during the continuous shooting of the servo AF.

The following step # 952 and the subsequent steps are the operation part related to the correction means of the present invention.

In steps # 952 to # 956, the exposure amount correction amount ALPHA is the previous exposure amount correction amount A.
When the amount of change in LPHA_OLD has changed by the second predetermined amount or more, the exposure amount correction amount ALPHA is not corrected.

The purpose of this processing is that when the exposure amount correction amount changes by a second predetermined value or more with respect to the previous exposure amount correction amount, a composition change and a sudden change in the light beam state occur. It is to obtain an appropriate exposure amount correction amount by determining that the exposure amount correction amount has not occurred and not correcting the exposure amount correction amount. [Step # 952] Here, the exposure correction amount ALPH
A level for checking whether A has changed by a second predetermined amount or more with respect to the previously obtained exposure amount correction amount ALPHA_OLD is set. Previously calculated exposure amount correction amount ALPHA_
The second predetermined value ALPHA_LVL is added to OLD,
This is level 1 (LVL1). [Step # 953] Previously obtained exposure amount correction amount ALP
The second predetermined value ALPHA_LVL is subtracted from HA_OLD, and this is set to level 2 (LVL2). [Step # 954] The exposure amount correction amount ALPHA is compared with the level 1 (LVL1), and the exposure amount correction amount ALPHA is compared.
28 is larger than the level 1 (LVL1), the exposure amount correction amount ALPHA should be used as it is in step # 9 of FIG.
62, and the exposure amount correction amount ALPHA is set to level 1 (L
If it is smaller than VL1), the process proceeds to step # 955 to make the next determination. [Step # 955] The exposure amount correction amount ALPHA is compared with the level 2 (LVL2), and the exposure amount correction amount ALPHA is compared.
28 is smaller than the level 2 (LVL2), the exposure amount correction amount ALPHA is used as it is, step # 9 in FIG.
62, and the exposure amount correction amount ALPHA is set to level 2 (L
If it is larger than VL2), FIG.
No. # 956.

In the following steps # 956 and thereafter, the exposure amount correction amount ALPHA is equal to the previous exposure amount correction amount ALPHA_.
A process of correcting the exposure amount correction amount ALPHA is performed when the amount of change exceeds the first predetermined amount with respect to OLD. [Step # 956] Here, the exposure correction amount ALPH
A threshold value is set so that A does not become larger than the previously determined exposure amount correction amount ALPHA_OLD by a first predetermined amount or more. Previously calculated exposure correction amount ALPHA_OLD
Is the first predetermined amount, a constant ALPH for limiting
A_DELTA is added and this is made the upper limit value TEMP1. [Step # 957] A threshold value is set so that the exposure amount correction amount ALPHA does not become smaller than the previously obtained exposure amount correction amount ALPHA_OLD by a predetermined amount or more. The exposure amount correction amount ALPHA_OLD obtained last time is subtracted by a constant ALPHA_DELTA for limiting, which is a first predetermined amount, and is set as a lower limit value TEMP2. [Step # 958] The exposure amount correction amount ALPHA is compared with the upper limit value TEMP1, and when the exposure amount correction amount ALPHA is less than the upper limit value TEMP1, the process proceeds to step # 960 to make the next determination, and the exposure amount correction amount ALPHA1 is reached. Is larger than the upper limit value TEMP1, the exposure amount correction amount ALPHA
To correct step # 959. [Step # 959] The exposure amount correction amount ALPHA is corrected to the upper limit value TEMP1. [Step # 960] The exposure amount correction amount ALPHA is compared with the lower limit value TEMP2. When the exposure amount correction value ALPHA is equal to or more than the lower limit value TEMP2, the process proceeds to step # 962 to make the next determination, and the exposure amount correction amount ALPHA is performed. Is smaller than the lower limit value TEMP2, the exposure amount correction amount ALPHA
Step 961 to correct the above. [Step # 961] The exposure amount correction amount ALPHA is corrected to the lower limit value TEMP2.

The following step # 962 is a part related to the storage means of the present invention, and the storage means stores the exposure amount correction amount ALPHA after being actually corrected. [Step # 962] The exposure amount correction amount ALPHA is stored and stored in ALPHA_OLD for the next photometric operation. [Step # 963] The subroutine "exposure amount correction amount calculation" is ended and the process returns.

Next, the subroutine "BV value calculation" will be described with reference to FIG.

The calculation for obtaining the BV value is performed by the calculation formula described in the above-mentioned subroutine "photometry". This arithmetic expression is to add the exposure amount at the time of backlighting to the average value weighted to the main subject, and the weighting ratio is the largest in the region of the main subject, and the region adjacent to the main subject is in the middle,
The background area has the smallest ratio. [Step # 1000] Subroutine "BV value calculation"
Is called, the CPU 100 executes step # 1001.
The following controls are performed. [Step # 1001] In order to weight the area of the main subject with the largest ratio, the value A, which is a value obtained by multiplying the brightness BVSA of the area of the selected distance measuring point by three, is obtained. [Step # 1002] In order to give an intermediate weighting to the brightness of the areas vertically and horizontally adjacent to the selected focus detection point, B
B, which is a value obtained by adding VSB1, BVSB2, and BVSB3, is obtained. [Step # 1003] Obtain a weighted average value,
Further, a calculation for adding the exposure correction amount at the time of backlight is performed. The arithmetic expression at this time is BV = (A + B + BVSUM) / 22 + ALPHA.

In the arithmetic expression, A is a value three times that of BVSA, B is a value of three areas, and BVSUM is a value of 16 areas. Therefore, (A + B + BVSUM) is divided by 22 to obtain a weighted average. You will be asked for the value. [Step # 1004] Subroutine "BV value calculation"
Ends and returns.

Here, the weighting of the brightness of the main subject will be described. The value A obtained in step # 1001 is three times the brightness BVSA of the main subject. Also, BVSU
M also contains BVSA. Therefore, since the information amount of the luminance of the main subject is 3 (BVSA) + (BVSA), that is, 4 (BVSA), the ratio is weighted by 4.

Next, the weighting of the brightness of the areas vertically and horizontally adjacent to the main subject will be described. Step # 10
The value B obtained in 02 is the sum of the brightness BVSB1, BVSB2, and BVSB3 in the upper, lower, left, and right regions adjacent to the main subject. Since BVSUM is the sum of all areas obtained by dividing the shooting range into 16 parts, BVSUM is also BVSB1, BVSB.
2, BVSB3 is included. Therefore, the information amount of the luminance of the area vertically and horizontally adjacent to the subject is 2 (BVSB1
+ BVSB2 + BVSB3), the ratio is weighted by 2.

Next, the weighting of the background area will be described. The background area is an area obtained by deleting the area of the main subject and the areas vertically and horizontally adjacent to the main subject from all areas obtained by dividing the photographing screen into 16 areas. Therefore, it is included only in BVSUM. Therefore, since the information amount of the brightness of the area in contact with the background area is 1, the ratio is weighted by 1. That is, the weighting is 4 for the area of the main subject, 2 for the areas vertically and horizontally adjacent to the main subject, and 1 for the background area.

[0157] Thus, the pair <br/> the weighted average by adding the exposure correction amount at the time of backlight, determine the BV value.

As described above, according to the first embodiment of the present invention, when shooting a moving subject, the exposure amount correction amount changes due to the delicate positional relationship of the background, and the exposure amount correction amount is changed. However, the first
If the value exceeds a predetermined value range of, the exposure amount correction amount is corrected to “previous exposure amount correction amount + first predetermined amount value” (step # 959 in FIG. 28), and exposure is performed. When the amount correction amount becomes a small value exceeding the range of the first predetermined value with respect to the previous amount exposure correction amount, the amount exposure correction amount is set to
By correcting (previous exposure amount correction amount-first predetermined amount value) (step # 961 in FIG. 28), it is possible to suppress the variation of the exposure amount due to the change of the exposure amount correction amount. There is.

Also, when shooting while following a moving subject, the composition or the state of the light beam changes greatly and the exposure amount correction amount changes, and the exposure amount correction amount is different from the previous exposure amount correction amount. When it becomes a large value exceeding the range of the second predetermined value (step # 954 in FIG. 27, YES),
Alternatively, when the exposure amount correction amount becomes a small value that ends the range of the second predetermined value with respect to the previous exposure amount correction amount (step # 955. YES in FIG. 27), the exposure amount correction amount is corrected. Instead, it is used as it is, and it is possible to obtain an appropriate exposure amount correction amount even when the light ray state changes during shooting or when the background changes extremely.
The second predetermined value is larger than the first predetermined value.

Further, the exposure amount correction amount is corrected only when photographing a moving subject such as the servo AF (step # 215. YES in FIG. 12), and the appropriate exposure amount correction amount is set. It is possible to obtain.

(Second Embodiment) In the first embodiment, as described above, when shooting while tracking a moving subject, the exposure amount correction amount changes due to the delicate positional relationship of the background. , The exposure correction amount is the first with respect to the previous exposure correction amount.
If the value exceeds the predetermined value range of, the exposure amount correction amount is set to “previous exposure amount correction amount + first predetermined amount value”.
When the exposure amount correction amount becomes a small value that exceeds the first predetermined value range with respect to the previous exposure amount correction amount,
By correcting the exposure amount correction amount to "the previous exposure amount correction amount-the value of the first predetermined amount", variations in the exposure amount due to changes in the exposure amount correction amount are suppressed.

In the second embodiment, the processes of steps # 958 to # 963 of FIG. 28 are performed as shown in FIG.
The process from step # 964 to # 968 is changed.

Specifically, when the exposure amount correction amount becomes a large value exceeding the range of the first predetermined value with respect to the previous exposure amount correction amount, the exposure amount correction amount is set to the previous exposure amount. If the exposure amount correction amount is smaller than the previous exposure amount correction amount by exceeding the first predetermined value range, the exposure amount correction amount is changed to the previous exposure amount correction amount. The exposure amount is corrected so that variations in the exposure amount due to changes in the exposure amount correction amount are suppressed.

(Correspondence between Invention and Example) In this example, the photometric sensor 10 and the photometric circuit 102 correspond to the photometric means of the present invention, and steps # 952 to # 9 of the CPU 100 are performed.
The part which performs the operation of 61 corresponds to the correcting means of the present invention, and C
The part that performs the operation of step # 962 of the PU 100 and the CP
A RAM (not shown) in U100 corresponds to the storage means of the present invention.

In addition, the step # of FIG.
602, # 603, a part that performs the operation of each step of FIGS. 18 to 20 of the CPU 100, and a CP
The portion of U100 that performs the operation of step # 607 in FIG. 17 corresponds to the computing means of the present invention. Further, steps # 901 to # 904 of the CPU 100 in FIG. 24 correspond to the light ray state determining means of the present invention, and a part for performing the operations of steps # 905 to # 909 of FIG. 24 of FIG. Corresponds to the exposure amount correction means of the present invention.

In addition, step # of FIG.
The portion performing the operations 950 and 951 corresponds to the prohibition means of the present invention.

The above is the correspondence relationship between each configuration of the embodiments and each configuration of the present invention, but the present invention is not limited to the configurations of these embodiments, and the functions or embodiments shown in the claims or the embodiments It goes without saying that any structure may be used as long as it can achieve the function of.

(Modification) According to this embodiment, the previous exposure amount correction amount is used when correcting the exposure amount correction amount. You may make it memorize and use this average value.
Also, in the first embodiment, steps # 954 and 955 are performed.
Alternatively, the correction amount may be constantly corrected and the limit value may be set.

The present invention is not limited to the single-lens reflex camera,
It may be applied to cameras such as lens shutter cameras and video cameras.

[0170]

As described above, according to the present invention, at least the past 1 calculated by the exposure amount correction unit is calculated.
Stores the value corresponding to the exposure correction amount for each time by the storage means
However, the latest exposure correction amount obtained during backlighting is stored.
When the exposure amount correction amount changes by a first predetermined value or more, the latest exposure amount correction amount is corrected.

[0171] Therefore, in a case such as shooting follows the subject to move, even when the change amount of exposure correction amount is greater than or equal by changing the delicate position of an object in the background, due to changes in the exposure correction amount It is possible to suppress variations in exposure amount.

Further , according to the present invention , the latest exposure amount correction amount obtained at the time of backlighting changes by the second predetermined value larger than the first predetermined value with respect to the stored exposure amount correction amount. In this case, it is determined that the latest exposure amount correction amount is not corrected because a composition change and a sudden change in the light ray state have occurred.

Therefore, even if the exposure amount correction amount largely changes, an appropriate exposure amount can be given.

[0174]

[0175]

[Brief description of drawings]

FIG. 1 is an optical system arrangement diagram when a first embodiment of the present invention is applied to a single-lens reflex camera.

FIG. 2 is a diagram showing a top surface and a back surface of the camera of FIG.

FIG. 3 is a diagram showing focus detection points and focus detection areas in the finder according to the first embodiment of the present invention.

FIG. 4 is a top view showing the structure of the mode dial of FIG.

5 is a diagram showing a structure of the electronic dial of FIG.

FIG. 6 is a block diagram showing the main configuration of the camera shown in FIG.

7 is an LCD for a monitor and an LCD in a finder shown in FIG.
FIG.

FIG. 8 is a flowchart showing a main operation of the camera of the first embodiment of the present invention.

9 is a flowchart showing a continuation of the operation of FIG.

FIG. 10 is a flowchart showing a continuation of the operation of FIG.

FIG. 11 is a flowchart showing a release sequence of the camera of the first embodiment of the present invention.

FIG. 12 is a flowchart showing a continuation of the operation of FIG.

13 is a flowchart showing a continuation of the operation of FIG.

FIG. 14 is a flowchart showing a “feed system interrupt process” operation of the camera of the first embodiment of the present invention.

FIG. 15 is a flowchart showing a “focus detection” operation of the camera of the first embodiment of the present invention.

FIG. 16 is a flowchart showing a “distance measuring point selection” operation of the camera of the first embodiment of the present invention.

FIG. 17 is a flowchart showing a “photometry” operation of the camera of the first embodiment of the present invention.

FIG. 18 is a flowchart showing an “AB calculation” operation of the camera of the first embodiment of the present invention.

19 is a flowchart showing a continuation of the operation of FIG.

FIG. 20 is a “C operation” of the camera of the first embodiment of the present invention.
It is a flowchart showing the operation.

FIG. 21 is a diagram showing an exposure amount correction amount at high brightness in the camera of the first embodiment of the present invention.

FIG. 22 is a diagram showing an exposure amount correction amount at medium brightness in the camera of the first embodiment of the present invention.

FIG. 23 is a diagram showing an exposure amount correction amount at low luminance in the camera of the first embodiment of the present invention.

FIG. 24 is a flowchart showing an “exposure amount correction amount calculation” operation of the camera of the first embodiment of the present invention.

FIG. 25 is a flowchart showing a continuation of the operation of FIG. 24.

FIG. 26 is a flowchart showing a continuation of the operation of FIG.

FIG. 27 is a flowchart showing a continuation of the operation of FIG. 24 or FIG. 25.

FIG. 28 is a flowchart showing a continuation of the operation of FIG. 27.

FIG. 29 is a flowchart showing the “BV value calculation” operation of the camera of the first embodiment of the present invention.

FIG. 30 is a flowchart showing a main part of “exposure amount correction amount calculation” operation of the camera of the second embodiment of the present invention.

[Explanation of symbols] 6 Focus detection device 6f line sensor 10 Photometric sensor 90 AF point selection button 100 CPU 102 Photometric circuit 110 Focus adjustment circuit

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Claims (7)

(57) [Claims] 1. A photometric means for measuring the brightness of a plurality of areas in a photographing screen, a computing means for calculating an exposure amount based on the output of the photometric means, and a light beam state discrimination based on the output of the photometric means. In the camera, the camera is provided with : a light ray state determination means; and an exposure amount correction means for calculating an exposure amount correction amount for correcting the exposure amount obtained by the calculation means based on the output of the light ray state determination means. A storage unit for storing a value corresponding to at least one past exposure amount correction amount calculated by the exposure amount correction unit, and the exposure amount correction unit.
The latest exposure correction amount obtained by the above is stored in the storage means.
When the value changes by a predetermined value or more, the latest exposure amount correction amount is corrected , while the latest exposure amount correction amount is corrected.
The quantity is greater than the first predetermined value with respect to the stored value of the storage means.
If the change is greater than the second predetermined value, which is even greater, the latest
Camera, characterized in that a and correction means does not correct the exposure correction amount. 2. The camera according to claim 1, wherein the light ray state determining means is means for determining a backlit state. 3. A prohibition unit for prohibiting the operation of the correction unit.
The camera according to claim 1 , further comprising: 4. The calculation means comprises a plurality of photometry means.
Exposure is performed by weighting each brightness value from the area.
The light ray state determining means is a means for calculating the quantity.
Exposure amount correction means for determining the degree of light condition
Is the backlight state determined by the light ray state determination means.
The camera according to claim 1 , wherein the camera is means for calculating an exposure correction amount having a value according to the degree . 5. The latest value for the stored value of the storage means
Whether or not the exposure correction amount of is changed by the first predetermined value or more
A first judging means for judging, wherein the correcting means is
It is judged by the judging means No. 1 that the change exceeds the first predetermined value.
When activated, it activates to identify the latest exposure correction amount
To a constant value, and the above-mentioned first judgment means described above.
The latest exposure amount correction amount is the first predetermined value
If it is determined that the change is within the value, the latest dew
Claim, characterized in that does not perform correction of the light amount correction amount 1
The listed camera. 6. The latest value for the stored value of the storage means
Whether or not the exposure correction amount of has changed by the second predetermined value or more
A second determining means for determining
It is judged by the second judging means that the value has changed by the second predetermined value or more.
If the latest exposure correction amount is not corrected,
Claim 5, wherein the camera, characterized in that brewing. 7. The specific constant value is relative to the stored value.
The camera according to claim 5, wherein the first predetermined value is a value obtained by adding the first predetermined value .