JP2926599B2 - Camera exposure calculation device - Google Patents

Description

The present invention relates to an exposure control device for a camera.

B. Conventional Technology A conventional camera exposure control device performs focus detection for a plurality of regions as described in Japanese Patent Application Laid-Open No. 1-105221, and as a result, corresponds to a region in focus. In this method, the luminance from an area is measured, and an exposure calculation is performed using the luminance information.

C. Problems to be Solved by the Invention In the above conventional technique, the focus detection to be focused is determined by a main subject selection calculation function built in the camera.

Therefore, when the main subject selected by calculation according to the algorithm preset in the camera and displayed is contrary to the photographer's intention, the photographer must reset the mode. No. However, prior to the idea that the photographer wants to focus on the "far left subject" or "far right subject" than the main subject selected by calculation, what should be selected from multiple algorithms It was extremely difficult to judge and operate instantaneously.

D. Means for Solving the Problems The present invention provides a camera in which a photographer can arbitrarily select a specific focus detection area from a plurality of focus detection areas and obtain an appropriate exposure value of the selected area. It is an object of the present invention to provide an exposure calculation device.

The present invention solves the above problems as follows. (1) Receiving light from an object field, focus detection is performed on a plurality of focus detection areas of the object field to be subjected to focus detection, and a focus detection output is output. Using the focus detection means to generate light, receiving light from the object scene, performing luminance measurement on a plurality of photometry areas to be measured in the object scene, and generating a luminance output; and using the focus detection output. Selecting means for selecting a focus detection area to be focused at the time of exposure from among a plurality of focus detection areas in which focus detection has been performed; and simultaneously displaying a state of focus detection of each of the plurality of focus detection areas, and selecting the Display means for notifying the focus detection area selected by the control means; area change means for changing the focus detection area selected by the selection means to another focus detection area; It has been the focus detection by the luminance output for metering area corresponding to the area, an exposure calculating means for calculating a proper exposure, exposure calculation device for a camera, characterized in that it consists of.

(2) The display means sets the focus detection state of the other focus detection area corresponding to the focus detection state of the focus detection area selected by the selection means as the focus detection state in accordance with the distance of the subject. The exposure calculation device for a camera according to (1), wherein the display is displayed.

E. Function According to the present invention, the focus detection area in the object scene selected by the calculation according to the algorithm set in advance in the camera can be confirmed by a clear display. And when the focus detection area is contrary to the photographer's intention,
It is easy to change to another intended area and obtain an appropriate exposure calculation value in that area.

F. Embodiment A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a first embodiment of a camera exposure control apparatus according to the present invention.

The taking lens 4 is controlled by the AF motor control means 10.
Driven by the AF motor 11.

The focus detecting means 9 is provided to receive the light passing through the photographing lens 4, and a plurality of recombination lenses 6a and 6b and a plurality of photoelectric conversion element groups 7a and 7b are arranged behind the predetermined focal plane 5 by the photographing lens 4. Have been. The output from each of the plurality of photoelectric conversion element groups 7a and 7b is
Is output to the focus detection circuit 8 provided in In the focus detection circuit 8, whether or not the image of the object is formed on the predetermined focal plane 5, that is, whether the object is in focus or out of focus, or when the object is out of focus, the image forming position is set to the predetermined focal plane 5. Whether the object side
That is, a so-called front focus or rear focus is determined, and further, a defocus amount De (i) of the front focus or the rear focus is calculated.

Each of the photoelectric conversion element groups 7a and 7b is composed of 120 pixels, each being a charge storage element, and is divided into six parts in this embodiment. A focus detection area (hereinafter referred to as AF) that optically corresponds to a plurality of areas of the object scene where focus detection is to be performed.
In this embodiment, six (areas) are used, and defocus amounts De (1) to De (6) in six A areas (i = 1 to 6).
Is calculated. Since the photoelectric conversion element groups 7a and 7b have the same structure, perform the same operation, and have the same area for focus detection, the photoelectric conversion element groups 7a and 7b
It may be explained as.

The focus detection output from the focus detection circuit 8 is output to the selection means 12.

The selecting means 12 outputs the result of ranking the defocus amounts De (1) to De (6) to the display means 21, and
From among De (1) to De (6), the one that satisfies the condition set separately is selected, and the number N of the AF area that gives the selected defocus amount De (i) is output to the display means 21 and the exposure calculation means 13. Then, the selected defocus amount De (N) is output to the AF motor control means 10.

For example, if the amount of deformed gas De (i) is obtained as shown in FIG. 3 (A), as will be described later, the AF area (1) is the rearmost focus, and the AF area (4) is the most in-focus. Close to
The AF area (6) is the forefront focus. Therefore, if the setting condition is “closest subject”, AF
The area (1) is selected, the defocus amount De (1) is output to the AF motor control means 10, and the selected area number "1" is output to the exposure calculation means 13. . Similarly, if the condition is "the subject closest to the focus", the AF area (4) is selected and the AF motor control means 10 is provided with a default.
The waste amount De (4) is output. If the focus cannot be detected and the amount of defocus is not calculated in any of the AF areas, a signal indicating that the focus cannot be detected is output to the AF motor control means 10 and the exposure calculation means 13 is output to the exposure calculation means 13. Outputs "0".

 Details of the selection means 12 will be described later.

When the AF motor control means 10 is out of focus, the lens 4 is driven by the AF motor 11 and moved to a position corresponding to the defocus amount De (N) output from the selection means 12. Let it. Whether the object is out of focus or in focus is determined, for example, by selecting means 12
When the magnitude of the defocus amount output from is within a predetermined range, it is determined that the object is in focus, and when not, it is out of focus.

The photometric unit 3 includes a photometric photoelectric conversion element 1 and a photometric circuit 2. The photoelectric conversion element 1 is a silicon photodiode (SPD), and the field is divided as shown in the figure. In the present embodiment, a photometric area (hereinafter, referred to as an AE area) optically corresponding to a plurality of areas of the object scene to be measured is set to 8
That is, photometry is performed by dividing the central portion into three AE regions 1a to 1c, the central portion into one AE region 1d, and the peripheral portion into four AE regions 1e to 1h. Here, the three AE regions 1a to 1c at the center of the photoelectric conversion element 1 have a corresponding relationship with respect to the focus detection range of the focus detection means 9. Details of the correspondence will be described later with reference to FIG.

The photometry circuit 2 has eight divided AEs of the photoelectric conversion element 1.
The photometric output from the area is input. The photometric circuit 2 converts the photometric output into a luminance value BV (k) (k = 1 to 8) using the open F-number signal Fo obtained from the photographing lens 4 and outputs the result to the exposure calculating means 13.

Exposure calculation means 13 receives the output of photometry means 3 and the output of selection means 12, calculates an appropriate exposure value B according to an algorithm set by the photometry mode setting means described later with reference to FIG. Output to

The exposure control means 14 receives the output of the proper exposure value B and
And the shutter 16.

Next, referring to FIG. 2, FIG. 3 (B) and FIG. 3 (C), three AE regions 1a at the center of the photoelectric conversion element 1 for photometry.
The positional relationship between .about.1c and the photoelectric conversion element group 7 of the focus detection means 9 will be described. FIG. 2 shows three photoelectric conversion elements at the center of the photoelectric conversion element 1.
FIG. 3B illustrates an optically corresponding positional relationship between the AE regions 1a to 1c and the photoelectric conversion element group 7 of the focus detection means 9, and FIG.
FIG. 7 shows a photoelectric conversion element group 7 of the focus detection means 9 and FIG.
FIG. 3C shows three AE regions 1 a to 1 at the center of the photoelectric conversion element 1.
It is a figure which shows 1c.

The length in the longitudinal direction of the photoelectric conversion element group 7 and the length in the longitudinal direction of the AE regions 1a to 1c at the center of the photoelectric conversion element 1 for photometry are almost the same length in an optically corresponding positional relationship. Is set to 3 (B) and FIG. 3 (C), the AF areas (7-1) and (7-2) on the left-hand side of the photoelectric conversion element group 7 with respect to the drawing are photoelectric conversion. AE area (1a) on the left side of the drawing of the central part of element 1
The AF area (7-
3) and (7-4) are located in the central AE region 1b at the center of the photometric photoelectric conversion element 1 on the right side of the photoelectric conversion element group 7 in the drawing.
One-third AF areas (7-5) and (7-6) are arranged corresponding to the right AE area 1b at the center of the photometric photoelectric conversion element 1, respectively.

FIG. 3A shows the AF area (7-
1) to (7-6) are plotted on the horizontal axis, and the defocus amount is plotted on the vertical axis. The positional relationship on the horizontal axis corresponds to FIG. 3B described above. Each of the AF areas (7-1) to (7-6) is a group of photoelectric conversion elements, and the amount of defocus and its direction (front focus, focus, rear focus) can be detected for each AF area. Is configured. In this figure, the AF area (7-
1) to (7-3) are rear pins, regions (7-4) to (7-
6) indicates a front pin.

The AF mode setting means 30 includes an autofocus mode in which the AF motor 11 is driven by the AF motor control means 10 based on the defocus amount output from the selection means 12 to focus, and a manual movement of the photographing lens 4 for focusing. One of the manual focus modes to be performed is selected and set, and the setting state is output to the AF motor control means 10 and the selection means 12.

The photometric mode setting means 31 is provided for the photometric photoelectric conversion element 1.
An average photometry mode that calculates an appropriate exposure value B using all outputs of 1a to 1h, and a center-weighted photometry mode that calculates an appropriate exposure value B using the outputs of 1a to 1d in the center and near the center, Using the outputs of the central portions 1a to 1c in accordance with an algorithm described later, one of the spot metering modes for calculating an appropriate exposure value B is selected, and the setting state is output to the focus selecting means 12 and the exposure calculating means 13.

The display means 21 determines the defocus amount and its direction (front focus, focus, rear focus) for each AF area of the photoelectric conversion element group 7 of the focus detection means 9 described with reference to FIGS. Is displayed so as to correspond to. Then, the AF area that gives the defocus amount selected by the above-described algorithm is determined to be an AF area.
It is displayed and announced in a different form from the AF area.

If the AF area giving the selected defocus amount notified by the display means 21 does not suit the photographer's intention, the area changing means 25 outputs the output for changing the AF area according to the photographer's will by adding the output of the area number. And to the selecting means 12 as a minus signal. The area changing means 25 may generate the signal according to the rotation direction of the multi-function dial of the camera as shown in FIG. 1 or may use a separately provided button.

Next, an example of the operation of the selection means 12 in the autofocus mode will be described in detail with reference to FIG. In the following, unless otherwise specified, the display means 21 and the exposure calculation means 13 will be described in the autofocus mode.

First, in step 100, the operation starts. step 1
In step 05, the selection means 12 reads the defocus amounts De (1) to De (6) of each AF area from the focus detection circuit 8
Go to 110. In step 110, the AF areas are ranked according to the numerical value of the defocus amount. The ranking is shown in Fig. 3 (A).
As an example, the order of the rear pin is Dr (1) =
1, Dr (2) = 2,..., Dr (6) = 6, and the order of each area is output to the display means 21 in step 115.

Next, in step 120, the focus amounts De (1) to De (6)
Are selected from among those satisfying the separately set conditions, and the number of the area to be selected is determined. For example, it is assumed that the defocus amount is obtained as shown in FIG. In this case, the AF area (7-1) is the rearmost focus, and the AF area (7-4)
Is closest to focusing, and the AF area (7-6) is the frontmost focus. Therefore, if the predetermined condition is “the closest subject”, the AF area (7-1) which is the rearmost focus is selected,
N = 1. Similarly, if the condition is "the subject closest to focus", the AF area (7-4) is selected, and N = 4. If the focus cannot be detected and the amount of defocus is not calculated in any of the regions, N = 0
And N obtained in step 120 is output to the display means and the exposure calculation means 13 in step 125.

Next, in step 130, according to the determined N, A
The defocus amount De (N) is output to the F motor control means 10. If N = 0, a signal indicating that the focus cannot be detected is output. Next, at 135, the defocus amount De (i) of each area is updated. In step 130, the defocus amount De (N) is output to the AF motor control means 10 and the photographing lens 4 is moved by driving the AF motor 11, so that the defocus amount of each area of the photographing lens 4 is obtained by using De ( i) (after update) = De (i) (before update)-De
(N) Defocus amount De of each area by (before update)
(I) is updated.

In the next step 140, the input of the area change signal from the area change means 25 is detected. If the area number after the area change is smaller than the area number before the area change, that is, if the area change signal (-) is received, the process proceeds to step 145, where the area number after the area change is larger than the area number before the area change. At this time, that is, if a (+) area change signal is received, the process proceeds to step 155. Step if the area number after the area change is the same as the area number before the area change or if no area change signal has been received
Enter the waiting state at 140.

If a forced interrupt signal such as a release signal is received in step 140, a release operation is performed, and after exposure, the flow is terminated.

In step 145, a condition determination for the (-) area change operation is performed. If N = 1, no further (−) area change operation can be performed, so the process returns to step 140 without changing N. If N = ≠ 1, go to step 150,
An area change operation of N (after change) = N (before change) -1 is performed, and the process returns to step 125. On the other hand, in step 155, (+)
The condition judgment for the area change operation is performed. If N = 6, no further (+) area change operation can be performed, and the process returns to step 140 without changing N. If N ≠ 6, the process proceeds to step 160, where an area change operation of N (after change) = N (before change) +1 is performed, and the process returns to step 125.

Next, a first example of the display means 21 will be described in detail with reference to FIGS.

FIGS. 5A and 5B show the display portion of the display means 21. FIG. The display part is a liquid crystal display, and is a part of the display part on the top of the camera or on the back cover. In the figure, the display portion is vertically and horizontally divided by the same number as the number of divisions of the AF area, and the number of segments is 6 × 6 = 36. In the vertical direction, columns X = 1 to 6 correspond to AF areas i [(7-
1) to (7-6)]. Also, the horizontal row Y =
1 to 6 respectively correspond to the rank Dr (i) of the AF area described above. Segment coordinates are segment (X, Y)
I will write it.

Next, an algorithm for driving the display means 21 is selected by the selection means 12.
Input signal region order Dr (i) and selected region number N
This will be described with reference to FIG.

First, the process starts at step 400 and proceeds to step 405. In step 405, it is determined whether focus detection is possible or impossible. If N = 0, the focus cannot be detected, and the process proceeds to step 415, where the focus cannot be detected. N ≠
If it is 0, the flow advances to step 410 to initialize the area number i and set i = 1. Next, at step 420, it is determined whether or not i is the same as the selected area number N. If i = N, since the AF area (i) is the selected AF area, the process proceeds to step 430 to notify the photographer, and the blinking of the segment (i, Dr (i)) is performed. If i ≠ N, the AF area has not been selected, so the process proceeds to step 425, and lighting of the segment (i, Dr (i)) is performed. In the next step 435, it is determined whether or not the above processing has been performed for each AF area up to i = 6. If i ≠ 6 and the processing is not completed, i is incremented in step 440 and the processing returns to step 420. If the processing is completed at i = 6, the process proceeds to step 445 and ends at step 445.

FIG. 5A shows a display example of a subject which can obtain the defocus amount shown in FIG. 3A as described above. In this case, since there is an algorithm for focusing and selecting the “closest subject”, N = 1, so that the segment (1, 1) in the drawing blinks, and the other segments (2, 2) to segment (6, 6) ) Is lit.

Next, FIG. 5B shows an example in which the area change operation of (+) is performed twice by the area change means 25 and the area is changed.
Shown in Since the selected area changes to N = 3, the segment (3, 3) blinks and the others are lit.

FIG. 5 (C) shows the focus detection impossible display in step 410.
The "+" mark may be made to blink on and off the entire display portion as shown in FIG. 5, or the entire row (in this example, Y =
3 and Y = 5; a plurality of rows as shown, or a single row of only one of the rows may be blinked).

The shape of the display portion of the display means 21 shown in FIGS. 5 (A) and 5 (B) will be described. As De (i) is closer to the subject as the rear focus is closer, Dr.
If you add (i), Dr
Displayed from the lower row of Y = 1 in descending order of (i). In addition, the shape of the entire display means 21 is easy to understand because the inverted trapezoidal shape having a long upper side is close to the distribution shape of the subject. The ratio of the length of the upper side to the lower side
Up to about 6: 4 (the number of area divisions: the number of area divisions−2), even when the segments (1, 1) and the segments (2, 6) are lit or blinking, the left and right positions are not reversed and are visually recognized. Good nature.

Next, a second example of the display means 21 will be described in detail with reference to FIGS. 7 and 8. FIG.

When the display portion of the display means 21 is displayed in the viewfinder, for example, as shown in FIG. 7 (D), the display portion is provided outside the screen, so that it is preferable that the display portion is small. In this example, as shown in FIG. 7 (A), the number of rows is reduced, the configuration is set to Y = 1 to 3, and it is flat and provided at the top or bottom of the screen.

The algorithm for driving the display means 21 of this embodiment will be described with reference to FIG.

First, the process starts in step 500 and proceeds to step 505.

In step 505, it is determined whether the focus can be detected or not. If N = 0, it means that the focus cannot be detected. N ≠
If it is 0, the process proceeds to step 515, where the initial setting of the area number i is performed, and i = 1.

Next, in step 520 and step 525, the conditions of the region order Dr (N) of the selected region are classified. This is because the line in which the in-focus area is notified is different, and when Dr (N) = 1, the step is performed.
The process proceeds from step 520 to step 555 and below. If Dr (N) = 6, the process proceeds from step 525 to step 580 and below. Dr (N) =
In the case of 2 to 5, the process proceeds to step 530.

First, the case where DR (N) = 1 will be described. At step 555, it is determined whether or not i is the same as the selected area number N. If i = N, the AF area (i) is the selected AF
Step 575 to notify the photographer because it is an area
To display the blinking of the segment (i, 1). In this case, the blinking segment is on the first row (Y = 1).
If i ≠ N, the AF area (i) has not been selected, so the process proceeds to step 560 to determine whether Dr (i) = 2. Considering the ease of photographer's area selection, the second row (Y
= 2) is for displaying only one area. Dr
If (i) = 2, the process proceeds to step 565, and the segment (i, 2) is turned on. If Dr (i) ≠ 2, the flow advances to step 570 to light the segment (i, 3).

If any of steps 565 to 575 has been completed, the process proceeds to step 605. In step 605, it is determined whether the above process has been performed for all AF areas. If i ≠ 6, the process has not been completed, and the process proceeds to step 610. Increment i and return to step 520. If the process is completed at i = 6, the process proceeds to step 615 and ends at step 615.

Next, the case where Dr (N) = 6 will be described. At step 580, it is determined whether or not i is the same as the selected area number N. If i = N, the AF area (i) is the selected AF
Step 600 to notify the photographer because it is an area
And the blinking display of the segment (i, 3) is performed.
In this case, the blinking segment is on the third row (Y = 3). If i ≠ N, the AF area has not been selected, so the process proceeds to step 585 to determine whether Dr (i) = 5. If Dr (i) = 5, go to step 590,
The segment (i, 2) is turned on. If Dr (i) ≠ 5, the process proceeds to step 595, where segment (i, 1) is turned on. When any of the processes in steps 590 to 600 is completed, the process proceeds to step 605 in the same manner as described above. Next, Dr (N) ≠
1. The case of Dr (N) ≠ 6 will be described. At step 530, it is determined whether or not i is equal to the selected area number N. If i = N, since the AF area (i) is the selected AF area, the process proceeds to step 550 to notify the photographer, and the blinking of the segment (i, 2) is performed. In this case, the blinking segment is on the second row (Y = 2).
If i ≠ N, the AF area has not been selected, so the process proceeds to step 535 to determine whether Dr (i) <Dr (N).

If Dr (i) <Dr (N), proceed to step 540,
The segment (i, 1) is turned on. Dr (i) <Dr
If not (N), the flow advances to step 545 to light the segment (i, 3). When any one of steps 540 to 550 is completed, the process proceeds to step 605 in the same manner as described above.

FIG. 7A shows a display example of a subject which can obtain the defocus amount shown in FIG. 3A as described above. In the case of the algorithm for focusing and selecting the “closest subject”, N = 1, so that the segment (1, 1) in the figure blinks, and the other segments (2, 2) to segment (6,
3) is a lighting display. Here, all the segments corresponding to the regions 3 to 6 are lighted in the third row because Dr (i) is 3 or more.

Next, the area change operation of (+) by the area change means 25 is 2
FIG. 7 (B) shows an example of the case where the AF area has been changed
Shown in The selected AF area changes to N = 3 and Dr (N) =
3 so that the algorithm goes through step 530 and below. Therefore, the segment (3, 2) blinks on the second line, and the segments corresponding to the AF areas (1) to (2) where Dr (i) <Dr (N) are lit on the first line. The segments corresponding to the A regions (4) to (6) where Dr (i) <Dr (N) do not hold are lit in the third row.

The focus detection impossible display in step 510 can be easily understood by blinking the entire second row as shown in FIG. 7 (C).

In the above, two preferred examples of the display means 21 have been described in detail, but the present invention is not limited thereto. In the above example, the display segment is a liquid crystal, but may be constituted by an LED or an EL element. Further, two examples of the display means 21 will be described in the embodiment of the present invention shown in FIG.
For example, both of them may be implemented in the upper part of the camera and in the viewfinder, or only one of them may be implemented.

Next, the exposure calculating means 13 will be described with reference to FIG. FIG. 9 is a flowchart showing the contents of the exposure calculating means 13.

The exposure calculation means 13 starts from the start of step 200.

In step 205, the luminance output Bv (k) of the photometric means 3
Is read. Here, k = 1 to 8, where k = 1 is the output of the AE area 1a of the photoelectric conversion element 1, k = 2 is the output of the AE area 1b, and similarly k = 8 is the output of the AE area 1h. Yes, it is.

In step 210, the selection area number N of the AF area which gives the defocus amount selected by the selection means 12 is read.

Next, in step 220, a photometric calculation algorithm is selected based on an input from the photometric mode setting means 31. When the setting of the photometry mode setting means 31 is the average photometry mode, the process proceeds to step 250. If the setting is the center-weighted metering mode, the process proceeds to step 245. If the setting is the spot metering mode, the process proceeds to step 225.

In step 250, the average photometric value Bw is calculated by using the outputs of all the photoelectric conversion elements 1a to 1h and the brightness outputs Bv (1) to Bv (8) by the following calculation.

In step 245, the outputs of the photoelectric conversion elements 1a to 1d, Bv
The center-weighted photometric value Bcw is calculated using (1) to Bv (4).

Bcw = ｛t × Bv (2) + u × (Bv (1) + Bv (3)) +
v × Bv (4)｝ / {t + (2 × u) + v} (where t>u> v) Multiplying each of the photometric values by a predetermined coefficient t, u, v is performed by assigning a weight to the center of the screen. This is because the photometric value of the section is used more heavily.

If the metering mode is the spot metering mode,
At 225, it is determined whether or not focus detection is possible.
If N = 0, the focus cannot be detected, so step 240
Then, the spot metering value is calculated when the main subject cannot be determined. If N ≠ 0, proceed to step 230.

In step 240, the outputs of the photoelectric conversion elements 1a to 1c, Bv
The spot photometric value Bso is calculated using (1) to Bv (3).

In this step, since the focus cannot be detected and it is difficult to determine the position of the main subject, Bv (1) to Bv (3) are averaged with emphasis on the stability of the photometric value.

If N ≠ 0, the focus can be detected.
The luminance information output by the photometry means 3 when the value is 0 or less, and the selection means 1
The spot metering value Bsa is calculated using the outputs of the photoelectric conversion elements 1a to 1c based on the focus selection area number N output by 2.

That is, when N = 1 or 2, the output Bv (1) of the photoelectric conversion element 1a is used, and when N = 3 or 4, the photoelectric conversion element 1a is used.
If N = 5 or 6, the output Bv (2) of the photoelectric conversion element 1c is the spot photometric value Bsa.

As described above, the spot metering value Bsa is set,
In step 230, the numerical conversion of N is performed by the following equation.

N (after conversion) = Int [(N (before conversion) +1) / 2] Here, Int (A) is a function representing the largest integer that does not exceed A. In the case of the above equation, N + 1 is divided by 2. The integer part of the value will be retrieved. Then, in the next step 235, a spot photometric value Bsa is obtained by the following equation.

Bsa = Bv (N) As described above, the final photometric value is obtained in step 23.
It is calculated by one of four photometric value calculation algorithms of 5 to 250. Then, the process proceeds to step 255 according to the above four photometric value calculation algorithms, and step 255
After outputting the finally determined photometric value to the exposure control means 14, the process proceeds to step 260 to end the calculation.

The above is the description of the first embodiment of the present invention shown in FIG.

Next, a second embodiment of the present invention will be described with reference to FIG.
In this embodiment, a photometric photoelectric conversion element is composed of a plurality of separated parts, and a part of the divided parts also serves as a distance measuring photoelectric conversion unit. Parts having the same functions as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The main parts of the second embodiment that differ from the first embodiment are as follows.

The point at which the photometric photoelectric conversion element 50 is divided into five AE regions 50a to 50e, and the luminance value at the center portion is determined by the focus detection circuit 8.
And the calculation algorithm of the exposure calculation means 63 is different. The photometric circuit 55 determines the brightness value according to the output of each element of the CCD type photoelectric conversion element group 7 for distance measurement obtained by the focus detection circuit 8 and the charge accumulation time. It is not limited to.

FIG. 11 is a flowchart showing the contents of the exposure calculating means 63 of the second embodiment. Begin at step 300.

In step 305, the luminance output Bv from the photometric means 3 is read.

Luminance output Bv of each AE area 50a to 50e of photoelectric conversion element 50
(K) is read as Bv (7) to Bv (11). K here
= 7 to 11 respectively correspond to the AE regions 50a to 50e.

In step 310, bV (1) to bV (120) are read from the photometric circuit 55 assuming that the luminance value of each element of the photoelectric conversion element group 7 is bV (j). (J = 1 to 120) In step 315, a brightness value Bv for each AF area is calculated by the following equation.

According to, the average value of bV (1) to bV (20) is converted to Bv (1),
The average value of bV (21) to bV (40) is set to Bv (2), and so on.
Assign up to Bv (6).

In step 320, the number N of the AF area which gives the defocus amount selected by the selection means 12 is read.

Next, in step 325, a photometric calculation algorithm is selected based on an input from the photometric mode setting means 31. When the setting of the photometry mode setting means 31 is the average photometry mode, the process proceeds to step 350. If the setting is the center-weighted metering mode, the process proceeds to step 345. If the setting is the spot metering mode, the process proceeds to step 330.

In step 350, the luminance values Bv (1) to Bv (6) by the photoelectric conversion element group 7 and the photoelectric conversion
The average photometric value Bw is calculated using all of the luminance values Bv (7) to Bv (11).

In step 345, the luminance value Bv obtained by the photoelectric conversion element group 7
(1) to Bv (6) and the luminance value Bv by the photoelectric conversion element 50a
The center-weighted photometric value Bcw is calculated using (7).

Bcw = ｛s × (Bv (3) + Bv (4)) + t × (Bv
(2) + Bv (5)) + u × (Bv (1) + Bv (6)) + v × Bv (7)｝ / {2 × (s + t + u) + v} (where s>t>u> v) Predetermined coefficient The reason why s, t, u, and v are each multiplied by the photometric value is that weighting is used and the photometric value at the center of the screen is used more heavily.

If the metering mode is the spot metering mode,
At 330, it is determined whether focus detection is possible or impossible. If N = 0, the focus cannot be detected, and the process proceeds to step 340 to calculate the spot photometric value when the main subject cannot be determined. If N ≠ 0, proceed to step 335.

In step 340, the luminance value Bv obtained by the photoelectric conversion element group 7
A spot photometric value is calculated using only (1) to Bv (6).

In this step, since the focus cannot be detected and the position of the main subject is difficult to determine, the stability of the photometric value is emphasized, and Bv (1) to Bv (1) to Bv
The averaging of (6) is performed.

If N ≠ 0, the focus can be detected.
5 or less, Bv (1) based on the outputs Bv (1) to Bv (6) of the photometric circuit 55 and the selection area number N output by the selection means 12.
ス ポ ッ ト Bv (6) is used to calculate the spot photometric value Bsa by the following equation.

Bsa = Bv (N) As described above, the final photometric value is calculated in step 33.
It is calculated by any one of four photometric value calculation algorithms of 5-350. Then, the process proceeds to step 355 after following the above four photometric value calculation algorithms. Step 3
After outputting the photometry value finally determined at 55 to the exposure control means 14, the calculation is terminated at step 360.

The above is the description of the second embodiment of the present invention shown in FIG.

G. Effects of the Invention According to the present invention, the focus detection area of the main subject selected by the calculation according to the algorithm set in advance inside the camera can be confirmed by a clear display. And when the focus detection area is contrary to the photographer's intention,
It is easy to change to another intended area and obtain an appropriate exposure calculation value in that area.

Therefore, a good photographing result reflecting the intention of the photographer can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of the first embodiment, FIG. 2 is a diagram showing an optically corresponding positional relationship between a photoelectric conversion element of a photometric unit and a photoelectric conversion element group of a focus detection unit, and FIGS. (C) is a diagram showing the relationship between the in-focus state of each area of the photoelectric conversion element group and the corresponding photometric area, FIG. 4 is an explanatory diagram of the operation of the selection means, and FIGS. 5 (A) to (D) are display means. FIG. 6 is an explanatory diagram of the operation of the first example of the display means, FIGS. 7A to 7D are diagrams of the second example of the display means, and FIG. FIG. 9 is an operation explanatory view of the second example of the means, FIG. 9 is an operation explanatory view of the exposure calculating means of the first embodiment, FIG. 10 is a block diagram of the second embodiment, and FIG. 11 is an exposure of the second embodiment. FIG. 7 is an explanatory diagram of the operation of the calculating means. (Description of Signs of Main Parts) 1... Photoelectric conversion element 3... Photometric means 7... Photoelectric conversion element group 9... Focus detection means 12... Selection means 13... Exposure calculation means 14. ... Display means 25 ... Area changing means 30 ... AF mode setting means 31 ... Metering mode setting means

Continuation of the front page (58) Fields investigated (Int.Cl. ⁶ , DB name) G03B 7/00 G03B 7/28 G03B 3/00 G02B 7/11 G03B 17/18-17/20

Claims (2)

(57) [Claims] 1. Focus detecting means for receiving light from a field, performing focus detection on a plurality of focus detection areas of the field to be detected, and generating a focus detection output; Receiving light of the subject, performs luminance measurement on a plurality of photometric regions to be photometrically measured in the object scene, and generates a luminance output. Selecting means for selecting a focus detection area to be focused at the time of exposure; and displaying a focus detection state of each of the plurality of focus detection areas at the same time and notifying the focus detection area selected by the selection means. Means for changing the focus detection area selected by the selection means to another focus detection area; and photometry corresponding to the changed focus detection area when changed by the area change means. The luminance output for range, an exposure calculating means for calculating a proper exposure, exposure calculation device for a camera, characterized in that it consists of. 2. The apparatus according to claim 1, wherein the display means corresponds to the focus detection state of the other focus detection area corresponding to the focus detection state of the focus detection area selected by the selection means, as the focus detection state. The exposure calculation device for a camera according to (1), wherein the display is displayed by being displayed.