JPH09203857A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain accurate spot light measurement information from the output of a range-finding sensor by reducing an error in light measurement originating from the spectral sensitivity of the range-finding sensor. SOLUTION: The range-finding sensor of a range-finding part 5 which has a range-finding area in the center of its photographic picture plane is used even as a light measuring sensor which takes a spot light measurement in the center of the picture plane. Data on a couple of linear images obtained by the range-finding sensor consisting of a line sensor are stored in standard part/reference part data areas 124a and 124b of a memory 124 and a light measurement arithmetic part 122 calculates spot light measurement data for AE control by using the image data in the standard part data area 124a. The arithmetic result is corrected into a proper value corresponding to the light source of a subject with correction data for correcting an output error of the range-finding sensor resulting from a difference of a light source stored in the correction data area 124e and then stored in an AE data area 124d. Thus, the light measurement data calculated by using the range-finding sensor are corrected with the correction data regarding the light source to obtain accurate spot light measurement information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automatic focusing (A
The present invention relates to a camera in which the distance measuring sensor for F) is also used as a photometric sensor for automatic exposure (AE), and the output of the distance measuring sensor is used to calculate spot photometric information at the center of the screen.

[0002]

2. Description of the Related Art Conventionally, a camera has been proposed in which a photometric sensor for AE is also used as a distance measuring sensor for AF, and spot photometric data is obtained by using the output of the distance measuring sensor. Since the spectral sensitivity of the AF sensor is generally biased in the infrared region, when the photometric information is obtained using the output of the AF sensor, the photometric information is obtained using the output of a normal AE sensor having spectral sensitivity in the visible region. Unlike the obtained photometric information, there is a problem in the photometric accuracy in using the photometric information as it is. Especially,
Separately has a photometric sensor that obtains average photometric information for the entire shooting screen, and based on the average photometric data obtained from the output of this photometric sensor and the spot photometric data obtained from the output of the above distance measuring sensor, the control exposure value is set. When setting, it is necessary to adjust the photometric level.

Hitherto, there has been proposed a photometric device which corrects photometric information calculated on the basis of the output of a distance measuring sensor to improve photometric accuracy. For example, JP-A-3-103072
In JP-A-7, the accuracy of the photometric information is improved by correcting the photometric information obtained based on the output of the distance measuring sensor with the correction data of the subject brightness obtained at the same position as the distance measuring area of the distance measuring sensor. It is shown that they are allowed to do so. That is, a photometric element that receives reflected light from the image pickup surface and monitors the subject brightness is provided at a position near the image pickup surface of the distance measurement sensor, and the distance measurement information is calculated using the output from the distance measurement sensor. The spot photometric information is calculated, and the calculation result of the spot photometric information is corrected by the correction data of the subject brightness calculated from the output of the photometric element.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The device disclosed in Japanese Patent No. 0727 has a photometric sensor for monitoring the brightness of the subject in the vicinity of the photometric sensor, and thus has a drawback in that the photometric device that also performs spot photometry becomes large. There is also a method of directly providing an IR cut filter to the distance measuring sensor to correct the output of the distance measuring sensor. However, in this case, reflection of incident light occurs at the IR cut filter, and as an original distance measuring sensor, Problems such as improperness and increase in cost due to increase in members occur, and it is desirable that the distance measuring sensor can also be used as much as possible without changing the configuration of the distance measuring sensor.

The present invention has been made in view of the above problems, and in a camera having a distance measuring sensor also serving as a light measuring sensor, a light measuring error caused by the spectral sensitivity of the distance measuring sensor is reduced and the distance measuring sensor is accurately measured. The present invention provides a camera capable of obtaining various spot photometric information.

[0006]

The present invention has an image pickup means having a spectral sensitivity deviated from the visible region, which is formed by arranging a plurality of photoelectric conversion elements linearly, and the image pickup means captures the image. In a camera in which distance measurement information for automatic focus adjustment is calculated based on image data of a subject, a calculation means for calculating photometry information for automatic exposure adjustment using the image data, and a spectral sensitivity of the image pickup means. It is provided with storage means for storing correction data for correcting an error of the photometric information based on characteristics, and correction means for correcting the calculation result of the calculation means with the correction data (claim 1).

According to the above construction, the photometric information for automatic exposure adjustment is calculated by using the image data of the subject captured by the image pickup means for obtaining the distance measurement information, and the calculation result is the spectrum of the image pickup means. It is corrected by the correction data for correcting the error based on the sensitivity characteristic. As a result, the error of the photometric information based on the spectral sensitivity characteristic of the image pickup means is corrected.

The image pickup means is preferably output-adjusted on the basis of the standard light source A (claim 2). With this configuration, when the light receiving means dedicated to photometry is separately provided, the output of the light receiving means and the image pickup means can be adjusted at the same time by the same standard light source A, and the output error between the light receiving means and the image pickup means can be reduced. It can be reduced.

In the camera, the correction data may be an output difference between the output of the image pickup means when the standard light source A is received and the output of the image pickup means when the standard light source B is received. 3). Alternatively, it is assumed that the correction data is an output difference between the output of the image pickup unit when the subject illuminated by the standard light source A is imaged and the output of the image pickup unit when the subject illuminated by the standard light source B is imaged. Good (Claim 4).

According to the above construction, in an outdoor shooting scene using sunlight as a light source, an error based on the difference in the light source of the photometric information calculated using the image data of the object is properly corrected.

The present invention is also the above-mentioned camera, comprising light source detection means for detecting a light source of an object, correction data for a plurality of light sources is stored in the storage means, and the correction means is detected. The calculation result of the calculation means is corrected by the correction data corresponding to the light source (claim 5).

According to the above arrangement, the light source of the subject is detected, and the error based on the difference of the light source of the photometric information calculated using the image data of the subject is corrected by the correction data corresponding to the light source.

Further, according to the present invention, in the above camera, the light source detection means determines whether or not the light source of the subject is an artificial light source based on a level change of image data obtained by driving the image pickup means in a predetermined cycle. This is to be determined (claim 6).

According to the above construction, the image pickup means is driven at a predetermined cycle, and the image data of the subject is captured a plurality of times.
Based on the level variation of these image data, it is determined whether or not the light source of the subject is an artificial light source. For example, when the light source of the subject is an artificial light source such as a fluorescent lamp that causes flicker, the flicker of the light source is detected on the basis of the image data, and thereby whether or not the light source of the subject is the artificial light source is identified.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The AE function of a camera according to the present invention will be described with reference to the drawings. FIG. 1 is a front view showing the external appearance of a camera according to the present invention. The camera 1 according to the present invention has an average photometry unit for average photometry of the entire photographic screen and a spot photometry unit for spot photometry of the center of the photographic screen.
The exposure control value for taking a photograph is automatically set based on the average photometric information and the spot photometric information. Moreover, the photometric sensor of the spot photometric unit automatically adjusts the focus (A
The distance measuring sensor for F) is also used.

The camera 1 has a photographing lens 3 formed of a lens shutter substantially in the center of the front of a camera body 2, and a photometric unit 4 is provided in the upper left of the photographing lens 3. Further, a distance measuring unit 5 is provided above the photographing lens 3, and a finder objective window 6 is provided on the left side thereof.

The photometric unit 4 is an SPC (Silicon Photo Cel).
l) etc. light receiving element (hereinafter referred to as AE sensor)
2 is an average photometry unit that receives the reflected light from the subject and averages the entire brightness within the photographic screen 7, as shown in FIG. The AE sensor has an IR cut filter on the image pickup surface and is adjusted so that its spectral sensitivity is in the visible region.

The distance measuring section 5 has a distance measuring area 8 in the center of the photographing screen 7, and the distance from the image information obtained by receiving the reflected light from the object included in the distance measuring area 8 to the object ( Hereinafter, it is referred to as a subject distance.) D (m) is detected. Further, the distance measuring unit 5 is, as shown in FIG. 3, an AF mainly including a pair of line image sensors 91 and 92.
The sensor 9 and the pair of microlens arrays 1 arranged in front of the line image sensors 91 and 92, respectively.
The lens system 10 is composed of 01 and 102. The line image sensors 91 and 92 are arranged on the same line with a predetermined interval. The line image sensors 91 and 92 are CCD line sensors in which a large number of charge-coupled devices (hereinafter, referred to as pixels) are linearly arranged, and the distance measuring unit 5 includes the line image sensors 91 and 9.
In step 2, the partial light image of the subject is received, and the subject distance D (m) is detected using the data (data output from each pixel. Hereinafter, referred to as pixel data) forming both light images.

The object distance D is determined by the line image sensor 9
Of the reference numerals 1, 92, the image pickup section of the line image sensor 91 on the side closer to the optical axis L of the finder optical system 11 is the reference section, and the image pickup section of the line image sensor 92 on the side farther from the optical axis L is the reference section. It is calculated from the amount of positional shift between the two images by comparing the linear image of No. 2 and the linear image of the reference portion.

The line image sensor 9 of the distance measuring unit 5
1 is also used as a photometric element for spot-photometrically measuring the center of the photographic screen, and as will be described later, spot photometric data at the center of the photographic screen is calculated using pixel data forming a linear image of the reference portion. The line image sensor 92
Can also be used as a photometric element, but in order to reduce the parallax between the visual field range of the finder optical system 8 and the photometric range of the AF sensor 9 as much as possible, the optical axis of the finder optical system 11 is used in this embodiment. The line image sensor 91 on the side closer to L is used as a spot photometric element.

FIG. 4 is a block diagram showing a photometry and distance measurement control system of the camera. In the figure, the CPU 12
It is a microcomputer that centrally controls a series of shooting operations of cameras such as AF, AE, and release. CPU 12
Has a distance calculation unit 121 for AF control, a photometry calculation unit 122 and a light source correction unit 123 for AE control, and a memory 124 for the above calculation processing.

The memory 124 is a reference part data area 124.
a, reference data area 124b, AF data area 1
24c, an AE data area 124d, and a correction data area 124e, and pixel data forming a linear image of the subject captured by the line image sensor 91 of the AF sensor 9 in the standard part data area 124a and the reference part data area 124b. (Hereinafter, referred to as reference portion data.) And pixel data (hereinafter referred to as reference portion data) forming a linear image of the subject captured by the line image sensor 92 are stored, and the reference is stored in the AF data area 124c. Data relating to the subject distance calculated using the partial data and the reference portion data (hereinafter referred to as AF data) is stored, and data relating to the subject brightness calculated using the reference portion data (hereinafter, referred to as AF data) is stored in the AE data area 124d. A
It is called E data. ) And average photometric data calculated by the photometric unit 4 are stored. Further, the correction data area 124e stores preset correction data relating to the light source of the subject. This correction data is for correcting the AE data, and the details will be described later.

The AF data is obtained by dividing the image pickup area of the reference portion into a plurality of AF areas and calculating each AF area.
The calculation result is stored in the AF data area 124c corresponding to each AF area, the AE data is calculated for each AE area by dividing the imaging area of the reference portion into a plurality of AE areas, and the calculation result is calculated for each AE area. It is stored in the AE data area 124d in association with the area.

FIG. 5 is a diagram showing an example of the AF area and the AE area set in the image pickup area of the line image sensor 91.

In the image pickup area of the line image sensor 91, six AE areas and six AF areas are set. The AE areas AE1 to AE6 are configured by equally dividing the image pickup area of the line image sensor 91 into six.
Further, the AE areas AF1 to AF6 are divided areas AR1 to AR6, which are obtained by equally dividing the image pickup area of the line image sensor 91 into six areas, where AF1 = AR1 + AR2, AF2 =
AR2 + AR3, AF3 = AR3 + AR4, AF4 = A
R4 + AR5, AF5 = AR5 + AR6, AF6 = AR
1 + AR2 + AR3 + AR4 + AR5 + AR6.

In the present embodiment, the AE areas AE1 to AE
Since each area of E6 corresponds to each of the divided areas AR1 to AR6, each of the AF areas AF1 to AF1
The AF6 is configured by combining the AE areas AE1 to AE6. This is AF area AF1-A
This is because, when AF control is performed by selecting any one of F6, AE data for a subject in the selected AF area can be detected, and exposure control can be performed based on this AE data.

Therefore, the AF area and the AE area are set such that the minimum size AE area has a size substantially equal to or smaller than the minimum size AF area, and
If each AF area is configured so as to include at least one AE area, the imaging area of the line image sensor 91 is divided by another method.
You may make it comprise an F area. It should be noted that when at least one AE area is included in each AF area, the AE data in the AE area corresponding to the AF area is a portion protruding from the AF area even if the AE area is slightly larger than the AF area. If it does not affect the AE data, the size of the AE area can be treated equivalently as the size of the AF area as AE data. In such a case, a strict size relationship between the AE area and the AF area is not required. Is.

Returning to FIG. 4, the distance calculation unit 121 uses each of the distance measurement areas AF1 to AF1 by using the reference portion data and the reference portion data.
The AF data is calculated for each AF 6, and the calculation result is stored in the addresses corresponding to the distance measuring areas AF1 to AF6 of the memory 124. Further, the photometric calculation unit 122
The AE data is calculated for each of the photometry areas AE1 to AE6 using the reference portion data, and the calculation result is stored in the address corresponding to each of the distance measurement areas AE1 to AE6 in the memory 124.

The calculation and storage of the AE data is performed by the AF
The calculation is performed before the AF data is calculated so as not to be affected by the data calculation. As a result, even when the AF sensor 9 is also used as the AE sensor for spot photometry, the storage area of the data for both calculations in the memory 124 is maintained. I try not to increase it as much as possible. That is, as will be described later, the AF data is calculated by converting the standard part data and the reference part data into difference data, centroid data, etc., respectively, and then calculating the correlation value between the standard part data and the reference part data. Therefore, if the AF data calculation is performed independently of the AE data calculation, it is necessary to separately store the reference part data and the reference part data for the AE data calculation. However, in the present embodiment, the AF data calculation is performed. By calculating the AE data before the calculation, the standard part data and the reference part data are not saved unnecessarily, and the increase in the memory capacity is reduced accordingly. Further, since one piece of AE data is calculated for each of the AE areas AE1 to AE6, AE data for finally calculating a control brightness value for AE control (hereinafter referred to as AE control data). The number is 6 and the memory for storing AE data is reduced as much as possible.

The light source correction unit 123 corrects the AE control data using the correction data. Also, AF
The control unit 13 controls the driving of the taking lens 3 and adjusts the focus of the taking lens 3.

Next, the calculation of AF data and AE data using the image picked up by the AF sensor 9 will be described.

FIG. 6 is a main flow of arithmetic control of AF data and AE data using an image picked up by the AF sensor 9. This flow is executed in the shooting preparation process performed by pressing the release button halfway.

First, the AF sensor 9 is driven for a predetermined time set in advance, and charges corresponding to the amount of received light are accumulated in each pixel of the line image sensors 91 and 92 (# 1). All pixel data of the line image sensors 91, 92 is CPU
12 and the pixel data of the reference portion is stored in the memory 124.
Stored in the standard portion data area 124 a of the reference portion and the pixel data of the reference portion is stored in the reference portion data area 124 of the memory 124.
It is stored in b (# 2).

Subsequently, the reference portion data is read from the reference portion data area 124a of the memory 124 for each AE area _AE1 to AE6, and the AE data D _{AE1 to} D _AE6 corresponding to each AE area _{AE1 to AE6} is calculated. (# 3).
For the calculation of the AE data D _{AE1 to} D _AE6 , for example, various methods shown in Table 1 below can be adopted. Each data content in Table 1 is calculated by the calculation formula shown in the table.

[0035]

[Table 1]

In Table 1, the method of "average value 1" is AE
The arithmetic mean value of all pixel data in the area is used as the AE data of the AE area. Since the method of "average value 1" averages the entire brightness in the area, proper exposure control can be performed when the brightness balance in the area is within a certain range. The method of "average value 2" is to set the arithmetic average value of all the remaining pixel data excluding the pixel data having the maximum brightness and the minimum brightness among the pixel data in the AE area as the AE data of the AE area. . The "average value 2" method is suitable even when the brightness balance in an area exceeds a certain range, because the influence of abnormally bright and dark parts is removed when the brightness balance in the area exceeds a certain range. This is a method that improves the method of "average value 1" because it can achieve various exposure controls.

Further, the method of "average value 3, 4" is based on only the pixel data in the AE area which has a luminance value below or above a predetermined threshold value set according to the average photometric value. The arithmetic mean value is used as the AE data of the AE area, which is a method capable of simplifying the arithmetic processing for AE control. That is, in the method of “average value 3, 4”, the bright part or the dark part is extracted with the threshold value based on the average photometric value as a reference, and therefore it is not necessary to separately determine the backlight of the shooting scene after calculating the AE data. It is possible to simplify the calculation processing when calculating the AE control data for the AE control using the AE data.

In the "minimum value" method, the pixel data having the minimum brightness among the pixel data in the AE area is set as the AE data of the AE area, and the "maximum value" method is
Among the pixel data in the AE area, the pixel data having the maximum brightness is used as the AE data of the AE area. The method of "minimum value" is suitable for overexposure control, and the method of "maximum value" is suitable for underexposure control.

Then, the calculated AE data is stored in the memory 1
After being stored in the 24 AE data area 124d (#
4) An AF area for AF control (AF area used for AF control; hereinafter referred to as AF control area) and the AF control area by using the reference portion data and the reference portion data stored in the memory 124. The subject distance D with respect to the subject is calculated, and the calculation result is stored in the AF data area 124c of the memory 124 (# 5). It should be noted that the subject distance D is the data of the reference portion for each AF area after data conversion of the reference portion data of the reference portion data area 124a and the reference portion data of the reference portion data area 124b into, for example, difference data or luminance centroid data. Is calculated from the correlation value obtained by comparing the data in the reference section with the data in the reference section.
Then, of the AF areas AF1 to AF6, for example, the AF area with the smallest subject distance D is selected as the AF control area.

Subsequently, the AF control area and the subject distance D
The AE area for AE control (the AE area used for AE control; hereinafter referred to as the AE control area) is set based on the above (# 6).

FIG. 7 shows the AF control area and the subject distance D.
It is an example of a chart diagram for selecting the AE control area based on. In the figure, "1" in the "AE area" column,
“2”, ..., “6” indicates AE1, AE2, ..., AE6, and “1”, “2”, ..., “6” in the “AF area” column
Indicates AF1, AF2, ..., AF6. “All low contrast” is a case where the focus positions of all the AF areas AF1 to AF6 cannot be detected due to low contrast. Also, "●" indicates the selected AE area,
"-" Indicates an AE area that was not selected.

In the AE area selection method shown in the figure, the subject distance D is divided into three stages of "short distance", "medium distance" and "long distance", and the same AF area is selected as the AF control area. Even in such a case, the selection range of the AE control area is gradually widened as the subject distance D approaches the “short distance” side. For example, when the AF area AF3 is selected as the AF control area, the AE area AE included in the AF area AF3 when the subject distance D is “long distance”.
3 and AE4 are selected as AE control areas, but when the subject distance D is "medium distance", AE areas AE2 and AE5 outside the AF area AF3 are added as AE control areas,
Furthermore, when the subject distance D becomes "short distance", all AE areas A
E1 to AE6 are selected as the AE control area.

It is desirable that the range of the AE control area is as wide as possible, but the size of the subject image with respect to the photographic screen is small for a subject at a long distance (see FIG. 8), and the AE area outside the AF control area is AE. When included in the control area, the subject and the background are included in the AE control area, and the AE control data calculated based on the AE data in the AE control area may be affected by the background brightness.
While the AE area in the control area is selected as the AE control area, the size of the object image with respect to the shooting screen gradually increases for an object at a medium or short distance,
Even if an AE area outside the control area is included in the AE control area, the background is unlikely to be included in the AE control area.
Since it is unlikely that the E control data is affected by the background brightness, the AE area outside the AF control area is also A
It is selected as the E control area.

Further, in the case of the present embodiment, the control is made so that the photographing can be performed even in the low contrast mode. Therefore, even when "all low contrast" or the AF area AF6 close to "all low contrast" is selected, the AE areas AE1 to AE6 are selected. Is used as the AE control area to calculate the AE control data.

When the position of spot metering of the subject is fixed, the size of the subject image in the photographing screen becomes smaller as the subject distance D becomes longer. Therefore, in order to obtain accurate AE control data, the subject image can be obtained. It is necessary to change the maximum size of the AE control area according to the spot photometric position (that is, the subject distance D).

For example, when a human of a standard size is assumed as the subject and a human face is set as the position of spot photometry, the relationship between the subject distance D and the maximum number of pixel data in the suitable AE control area is shown in the figure. As shown by the dotted line in FIG. 9, when the human torso is set as the position of spot photometry, the relationship between the subject distance D and the maximum number of pixel data in the preferable AE control area is shown by the dashed line in FIG. Like Therefore, when a human face is assumed as the position of spot photometry and the maximum size of the control AE area is set according to the subject distance D, the size of the AE control area becomes extremely small for a subject at a long distance.

However, when the subject is a human, the framing of the subject of the photographer is generally performed so that the face of the subject K enters the center of the photographing screen 7 at a short distance as shown in FIG. 8, but at a long distance. Since the entire subject K is placed as much as possible within the photographing screen 7 and the position of spot metering of the subject changes depending on the subject distance D, a certain distance D
It is necessary to perform spot metering on the face of the subject K for a subject K at a short distance of 1 or less, but spot metering for the body of the subject K for a subject K farther than a certain distance D1. It can be performed.

Therefore, the AE suitable for the object distance D is obtained.
In FIG. 9, the number of pixel data in the control area can be switched from a certain distance D1 to a larger number of pixel data having the relation shown by in a longer distance than the certain distance D1.
In the setting of the range of the AE control area in FIG. 7, in consideration of the above, two AE areas included in the AF control area are selected as the AE control area even when the subject is a long distance, and the AE control is performed as much as possible. The area is widened so that suitable AE data can be obtained.

In FIG. 9, the relationship (concatenation of the relationship for switching from to at the distance D1) gives the maximum number of pixel data in the AE control area, and is less than or equal to this pixel data number. The range indicates the range of the AE control area that is less affected by the background. In the present embodiment, since spotlighting is also performed by using the outside light type distance measuring unit 5 as well, A according to the subject distance D
Although the E control area is set, when the distance measuring unit 5 is configured by the TTL (Through The Lens) method, the AE control area is set according to the image magnification β instead of the object distance D. It is good to do so.

10 and 11 show "AE control area selection based on AF control area and subject distance D".
8 shows an execution procedure of the AE control area selection method shown in FIG. 7 in the "area selection" subroutine.

First, it is sequentially determined whether or not all the AF areas are low contrast or whether the AF area AF6 is set as the AF control area (# 11, # 1).
2) If all low contrast or AF area AF6 is set as the AF control area (YE in # 11 and # 12)
S), AE areas AE1 to AE6 are set as AE control areas (# 24), and the process returns.

All are not low contrast, and the AF area AF6 is not set as the AF control area (# 11, # 1
If NO in 2), the distance range of the subject is determined from the subject distance D (# 13, # 14). Subject distance is "short distance"
If (b> D) (YES in # 13), AE area A
E1 to AE6 are set as AE control areas (# 2
4) Return and subject distance is "long distance" (D ≧ a)
If so (NO in # 14), it is sequentially determined whether or not each of the AF areas AF1 to AF4 has been selected as an AF control area (# 15, # 1).
7, # 19, # 21).

If the AF area AF1 is set as the AF control area (YES in # 15), the AE areas AE1 and AE2 are set as the AE control areas (# 1).
6) If the AF area AF2 is set as the AF control area (YES in # 17), the AE areas AE2, AE3
Is set as the AE control area (# 18), and the AF area AF3 is set as the AF control area (# 19).
YES), AE areas AE3 and AE4 are set as AE control areas (# 20), and AF area AF4 is set to AF.
If it is set in the control area (YES in # 21), A
The E areas AE4 and AE5 are set as the AE control areas (# 22), the process returns, and the AF areas AF1 to AF
If none of 4 is selected, that is, if the AF area AF5 is set as the AF control area (NO in # 21), the AE areas AE5 and AE6 are set as the AE control area (# 23), and the return is executed. To do.

If the subject distance is "medium distance"(a> D≥b) (YES in # 14), AF area AF1 or AF
2 is set in the AF control area (# 25), and if the AF area AF1 or AF3 is set in the AF control area (YES in # 25), the AE areas AE1 to AE4 are AE controlled. The area is set (# 26) and the process returns. In addition, the AF area AF1,
If AF2 is not set in the AF control area (# 2
5 is NO), and then it is determined whether or not the AF area AF3 is set as the AF control area (# 27).
If area AF3 is set as the AF control area (#
(YES in 27), the AE areas AE2 to AE5 are set as the AE control areas (# 28), and the AF area AF3 is not set as the AF control area (N in # 27).
O), AE areas AE3 to AE6 are set as AE control areas (# 29), and the process returns.

Returning to the flowchart of FIG. 6, when the setting of the AE control area is completed, the AE control data is subsequently calculated using the AE data in the set AE control area (# 7).

FIG. 12 is an example of a subroutine for calculating the AE control data, in which the calculation of the AE control data is switched according to the object distance D. That is, it is determined whether or not the subject distance D exceeds an appropriate predetermined distance a ′ (> a) of, for example, 4 m or more (# 3
1) If the subject distance D exceeds the predetermined distance a '(YES in # 31), the lowest brightness value min {of the brightness values B1, B2, ... Of the AE area selected as the AE control area. B1, B2, ...} is set as the AE control data (# 32), and the subject distance D is equal to or less than the predetermined distance a '(NO in # 31), the brightness value of the AE area selected as the AE control area. Average value B of B1, B2, ...
_AVE (= ΣBi / m, Bi; i-th luminance value, m; number of luminance values) is set as AE control data (# 3
3) Return.

In the above method, when the subject is at a long distance,
When the subject distance D is longer than the predetermined distance a ', the lowest luminance value is used as the AE control data because the subject image in the shooting screen is small and the influence of the subject edge is large. The effect of is reduced. In this case as well, the perspective of the subject can be determined by the image magnification β instead of the subject distance D.

Further, a constant arithmetic expression is irrespective of the object distance D, for example, (1) "average value 1" to (5) shown in Table 1 above.
The AE control data may be calculated by the arithmetic expression of "minimum value".

In the method of "average value 1", the brightness in the AE control area is averaged, so that even when the AE control data is calculated in the widest possible area, the variation in the calculation result can be reduced. The method of “average value 2” is a method of improving “average value 1” and can reduce the influence of the abnormal value even when the luminance balance is abnormally large. Also,
The method of "minimum value" is easier than the method of "average value 1" when the retrograde scene is determined by comparing the average brightness value of the entire photographing screen obtained by the photometric unit 4 with the AE control data. There is an advantage that the backlight discrimination can be performed. Also,
The methods of "average value 3" and "average value 4" extract the bright part or the dark part on the basis of the threshold value based on the average photometric value, and therefore have the advantage that backlight discrimination can be performed easily and accurately. .

Once the AE control data has been calculated, then
This AE control data is corrected (# 8). This correction is to correct an error in the AE control data that occurs when the light source of the subject is different from the adjusted light source of the AF sensor 9 according to the light source of the subject.

The standard light source A, the standard light source B and the standard light source C for colorimetry each have the spectral characteristics shown in FIG. 13, and the spectral characteristics of the standard light source A are much more red than those of the standard light sources B and C. Biased to the outer area. On the other hand, the line image sensor 9
The SPCs arranged as photoelectric conversion elements on the image pickup surfaces of 1, 92 have, for example, the specific sensitivity distribution shown in FIG. 14, and the SPC output when the standard light sources A, B, and C are respectively received by this SPC is shown in FIG. 15, the standard light source B,
The SPC output for C is less than half that of the standard light source A.

When the AF sensor 9 is also used as an AE sensor for spot photometry, it is necessary to perform level matching between the spot photometric value by the AF sensor 9 and the average photometric value by the AE sensor of the photometric unit 5, and normally the photometric unit 5 Since the output characteristic of the AE sensor is adjusted with respect to the standard light source A, the output characteristic of the AF sensor 9 is also adjusted with respect to the standard light source A.

Therefore, when photography is performed outdoors using sunlight as a light source, the light source (standard light source A) whose output characteristics of the AF sensor 9 are adjusted and the actual light source (light sources close to the standard light sources B and C) Therefore, the control brightness value obtained from the output of the AF sensor 9 is smaller than the actual brightness value. A above
The correction of the E control data corrects the output level from the AF sensor 9 due to the difference in the light source of the subject, and the correction data area 124e of the memory 124 is used for this correction.
In addition, correction data ΔB _B (≈1.21 EV) for correcting the difference between the output of the AF sensor 9 when the standard light source A is received and the output of the AF sensor 9 when the standard light source B is received, and the standard light source A The correction data ΔB _C (≈1.51 EV) for correcting the difference between the output of the AF sensor 9 when the light is received and the output of the AF sensor 9 when the standard light source C is received is calculated and stored in advance. .

Then, the correction data ΔB _B or the correction data ΔB _C is added to the AE control data to perform the correction.

The flow chart of FIG. 6 is based on the standard of shooting with outdoor sunlight, and the AE control data is always corrected by the correction data ΔB _B or the correction data ΔB _C , but it is preferable. The camera may be provided with a light source detection function, and the AE control data may be corrected according to the detected light source.

In this case, instead of step # 8, as shown in FIG.
Is performed. That is, after calculating the AE control data, the light source of the subject is detected (# 41), and it is determined whether the detected light source is the standard light source A or the standard light source B (# 42, # 43). If the light source of the subject is the standard light source A (YES in # 42), the process ends without correction. Further, if the object of the light source is a standard light source B (YES at # 43), adds the correction data .DELTA.B _B for AE control data (# 44), light source Utsushitai standard light source C
If so (YES in # 43), the correction data ΔB _C is added to the AE control data (# 45), and the process ends.

For light source detection, for example, a photometric sensor for WB is provided, and R (red) output from this photometric sensor,
The light source may be directly detected by the color component data of G (green) and B (blue). Alternatively, only the fluorescent lamp may be identified by driving the AE sensor 9 at a frequency higher than the flicker cycle of the fluorescent lamp and checking whether or not the sampling level has changed.

Further, in the present embodiment, the level difference between the standard light source B or the standard light source C with respect to the standard light source A when the standard light sources A, B and C are directly received by the AF sensor 9 is used as the correction data. , A when the reflected light of the standard light source A is received by illuminating an actual subject with the standard light sources A, B, and C
The difference ΔB _B ′ between the output of the F sensor 9 and the output of the AF sensor 9 when the reflected light of the standard light source B is received, and the output of the AF sensor 9 and the standard light source C when the reflected light of the standard light source A is received. The difference ΔB _C ′ from the output of the AF sensor 9 when the reflected light is received may be used as the correction data. In the former case, the light from the standard light source is directly received, so the correction data is for the standard reflectance of 18%, but in the latter case,
Since the reflected light from the subject is received, it becomes closer to the correction data for the actual subject, and A
The E control data can be corrected.

Since the output adjustments of the AF sensor 9 of the distance measuring unit 5 and the AE sensor of the photometric unit 4 are performed on the standard light source A, the same standard light source is used at the same time as shown in the flowchart of FIG. Good to do.

That is, first, the camera is attached to the adjuster (# 51), and the emission brightness of the standard light source A is set to the predetermined value S (E
After being set to V), it is turned on (# 52, # 53). Then, the outputs of the AE sensor 9 and the AE sensor are equal to the predetermined value S.
So that the sensitivity of both sensors is adjusted (# 54, #
55). This sensitivity adjustment is performed by changing the offset level of the sensor output.

After that, the light emission brightness of the standard light source A is changed to a value S'other than the predetermined value S (# 56), and changes in the outputs of the AE sensor 9 and the AE sensor are confirmed (# 57, # 5).
8). If the outputs of the AE sensor 9 and the AE sensor are not the predetermined values S '(NO in # 57 or # 58), # 5
2, the readjustment is performed, and when the outputs of the AE sensor 9 and the AE sensor reach the predetermined values S '(# 57, # 5
8 is YES), the standard light source A is turned off (# 59), the camera is removed from the adjuster, and the adjustment is finished (# 60).

By performing the simultaneous adjustment in this way,
Adjustment work can be simplified, and AF sensor 9 and AE
Adjustment error between the sensors can be reduced.

[0073]

As described above, according to the present invention,
A plurality of photoelectric conversion elements are linearly arranged and have an image pickup means having a spectral sensitivity deviated from the visible region. For automatic focus adjustment based on image data of a subject captured by this image pickup means. In the camera in which the distance measurement information is calculated, the light measurement information for automatic exposure adjustment is calculated based on the image data of the subject, and the calculation result is corrected by the correction data concerning the spectral characteristic of the image pickup means. Therefore, the error of the photometric information based on the spectral sensitivity characteristic of the image pickup means is properly corrected, and accurate photometric information can be obtained.

Further, since the image pickup means adjusts the output with reference to the standard light source A, even when the light receiving means dedicated to photometry is separately provided, the light receiving means and the image pickup means are simultaneously operated by the same standard light source A. The output can be adjusted and the output error between the light receiving means and the image pickup means can be reduced.

Since the correction data is the output difference between the output of the image pickup means when the standard light source A is received and the output of the image pickup means when the standard light source B is received, outdoor sunlight is used as the light source. Therefore, suitable spot photometric information can be obtained for a subject having a standard reflectance (18%).

The correction data is the output difference between the output of the image pickup means when the subject illuminated by the standard light source A is imaged and the output of the image pickup means when the subject illuminated by the standard light source B is imaged. Therefore, more accurate spot photometric information can be obtained for a person whose outdoor light source is sunlight.

Further, light source detection means for detecting the light source of the object is provided, correction data for a plurality of light sources is stored in the storage means, and the calculation result of the calculation means is corrected by the correction data corresponding to the detected light sources. Since this is done, accurate spot photometric information can be obtained even when the light source is different.

Further, since it is determined whether the light source is an artificial light source or not based on the level variation of the image data obtained by driving the image pickup means in a predetermined cycle, the light source can be easily determined with a simple structure. You can

[Brief description of drawings]

FIG. 1 is a front view showing an appearance of a camera according to the present invention.

FIG. 2 is a diagram illustrating a ranging area in a shooting screen.

FIG. 3 is a diagram showing a schematic configuration of a distance measuring unit.

FIG. 4 is a block diagram showing a photometry and distance measurement control system of the camera.

FIG. 5 is a diagram showing an example of an AF area and an AE area set in an imaging area of a line image sensor of a reference portion.

FIG. 6 is a main flow of arithmetic control of AF data and AE data using a captured image by an AF sensor.

FIG. 7 is a chart of a method of selecting an AE control area based on an AF control area and a subject distance.

FIG. 8 is a diagram showing spot photometric positions by a distance measuring sensor at each subject distance.

FIG. 9 is a diagram showing a preferable maximum number of pixel data in an AE control area with respect to a subject distance.

FIG. 10 is a subroutine of “AE control area setting”.

FIG. 11 is a subroutine of “AE control area setting”.

FIG. 12 is a subroutine for calculating AE control data.

FIG. 13 is a diagram showing spectral characteristics of standard light sources A, B, and C.

FIG. 14 is a diagram showing a specific sensitivity distribution of the AF sensor.

FIG. 15 is a diagram showing a light receiving characteristic of an AF sensor with respect to a standard light source.

FIG. 16 is a diagram showing a correction process of AE control data according to light source detection.

FIG. 17 is a flowchart for adjusting the outputs of the AF sensor and the AE sensor.

[Explanation of symbols]

 1 Camera 2 Camera Main Body 3 Photographing Lens 4 Photometry Section 5 Distance Measurement Section 6 Viewfinder Objective Window 7 Photographing Screen 8 Distance Measurement Area 9 AF Sensor (Imaging Means) 91,92 Line Image Sensor 10 Lens System 101,102 Microlens Array 11 Finder Optical system 12 CPU (calculation means, correction means, light source detection means) 121 Distance calculation part 122 Photometric calculation part 123 Light source correction part 124 Memory (storage means) 124a Reference part data area 124b Reference part data area 124c AF data area 124d AE data Area 124e Correction data area 13 AF control unit K Subject L Optical axis

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Akira Shiraishi 2-3-13 Azuchi-cho, Chuo-ku, Osaka City Osaka International Building Minolta Co., Ltd. (72) Kyoichi Miyazaki 2-3-3 Azuchi-cho, Chuo-ku, Osaka No. 13 Osaka International Building Minolta Co., Ltd. (72) Inventor Yoshinori Sugiyama 2-3-3 Azuchicho, Chuo-ku, Osaka City Osaka International Building Minolta Co., Ltd.

Claims (6)

[Claims] 1. An image pickup unit having a spectral sensitivity characteristic deviated from a visible region, which is formed by arranging a plurality of photoelectric conversion elements linearly, and based on image data of a subject captured by the image pickup unit. In a camera in which distance measurement information for automatic focus adjustment is calculated, calculation means for calculating photometry information for automatic exposure adjustment using the image data, and the photometry information based on the spectral sensitivity characteristic of the image pickup means. A camera comprising: storage means for storing correction data for correcting an error; and correction means for correcting a calculation result of the calculation means with the correction data. 2. The camera according to claim 1, wherein the image pickup means is output-adjusted with reference to a standard light source A. 3. The camera according to claim 2, wherein the correction data is an output difference between an output of the image pickup means when the standard light source A is received and an output of the image pickup means when the standard light source B is received. A camera characterized by that. 4. The camera according to claim 2, wherein the correction data is the output of the image pickup means when the object illuminated by the standard light source A is imaged and the image when the object illuminated by the standard light source B is imaged. A camera having an output difference from the output of the imaging means. 5. The camera according to claim 1, further comprising light source detection means for detecting a light source of a subject, wherein the storage means stores correction data for a plurality of light sources, and the correction means detects the light sources. A camera for correcting the calculation result of the calculation means with correction data corresponding to a light source. 6. The light source detection means according to claim 5 determines whether or not the light source of the subject is an artificial light source based on the level fluctuation of image data obtained by driving the imaging means at a predetermined cycle. A camera characterized by being.