JP2001305423A - Range finder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deviation of a main object range intended by a photographer from a found range to the minimum, in the case of enlarging a range finding extent in accordance with the focal distance of a photographing optical system. SOLUTION: A divided area to be used for measuring the object range is selected out of plural divided areas AREA0 to AREA7 of photoelectric conversion element arrays 22a and 22b in accordance with the focal distance of the variable-focal distance photographing optical system, and information on the distance up to the object is calculated based on the image deviation quantity detected in the selected divided area, and in the case the image deviation quantity is not detected in all the divided areas selected in accordance with the focal distance of the photographing optical system, the divided area to be used for measuring the object range is horizontally enlarged stepwise until the divided area where the image deviation quantity is detected is found. Thus, such the failure is eliminated that the range finding value of both end parts of the corresponding photographing screen to the focal distance of the photographing optical system or outside the photographing screen is used and an operation of finding the range of the main object intended by the photographer is not performed, thus, the deviation of the main object range intended by the photographer from the found range is suppressed to the minimum in the case of enlarging the range finding extent in accordance with the focal distance of the photographing optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passive distance measuring apparatus for measuring a photographing distance to a subject by an optical triangulation method.

[0002]

2. Description of the Related Art In order to focus a photographing lens of a camera on a subject, a passive distance measuring apparatus that measures a photographing distance to the subject by an optical triangulation method is known. In an autofocus camera equipped with this type of distance measuring device, a photographing optical system, a finder optical system, and an optical system of the distance measuring device (hereinafter, referred to as a distance measuring optical system) are provided separately and independently. Have been.

Further, a zoom lens having a variable focal length may be used in a photographing optical system of an autofocus camera having the above-described distance measuring device. In such a distance measuring device for a camera with a zoom lens, the focal length of the finder optical system is changed according to the focal length of the zoom lens, but the distance measuring optical system has a fixed focal point.

In the above-described camera with a zoom lens, since the focal length of the distance measuring optical system does not change even if the focal length of the zoom lens is changed, the distance measuring range does not change and remains constant.
In other words, distance measurement is performed in the same range of the object field on both the wide-angle side and the telephoto side of the zoom lens.When the zoom lens is on the telephoto side, the distance measurement range on the shooting screen is wider than on the wide-angle side. At the telephoto end, the distance measurement range may extend beyond the shooting screen.

In order to avoid such inconvenience, the photoelectric conversion element array for distance measurement is divided into a plurality of regions, and the distance measurement range in the photographing screen becomes substantially constant even when the focal length of the zoom lens changes. As described above, there is known a distance measuring device that determines a range of a photoelectric conversion element array used for measuring a subject distance according to a focal length of a zoom lens.

In the latter camera with a zoom lens, the photoelectric conversion element array is divided into a plurality of areas, and when the zoom lens is on the telephoto side, the center divided area of the photoelectric conversion element array is selected for object distance measurement. The divided area for measuring the subject distance is expanded to the left and right divided areas as the position becomes wider. In this apparatus, a distance measurement value is calculated for each divided region of the photoelectric conversion element array, and if a distance measurement value cannot be obtained in all the divided regions selected according to the focal length of the zoom lens, a distance measurement value other than the selected region is obtained. The area in which the distance measurement value is obtained is searched from all the divided areas, and the distance measurement value of the area is set as the distance measurement value for the current focal length of the zoom lens.

[0007]

However, in the latter distance measuring device for a camera with a zoom lens, when a distance measurement value cannot be obtained in all of the divided areas selected according to the focal length of the zoom lens. Since the area where the distance measurement value is obtained is searched from all the divided areas other than the selected area, and the distance measurement value of that area is set as the distance measurement value for the current focal length of the zoom lens, the current focus of the zoom lens is In some cases, ranging values at both ends of the shooting screen or outside the shooting screen according to the distance are adopted, and the main subject intended by the photographer cannot be measured. For example, when shooting a portrait of a night scene, if the subject cannot be measured at a low contrast on the telephoto side of the zoom lens, the photographer may want to focus on a different shooting screen than the person in the center of the shooting screen. There is a problem that the distance is measured at both ends or outside the shooting screen.

SUMMARY OF THE INVENTION It is an object of the present invention to minimize the deviation between the distance of the main subject intended by the photographer and the measured distance when expanding the distance measuring range according to the focal length of the photographing optical system. is there.

[0009]

Means for Solving the Problems The present invention will be described with reference to FIG. 1 showing the configuration of one embodiment. (1) The invention according to claim 1 comprises a pair of photoelectric conversion elements each comprising a plurality of photoelectric conversion elements. Charge storage type photoelectric conversion element array 22
A distance measuring optical system 21 having a fixed focal length for guiding a pair of subject lights to the pair of photoelectric conversion element arrays 22; and dividing each photoelectric conversion element array 22 into a plurality of regions, and performing a correlation operation for each divided region. Calculating means 1 for detecting the amount of image shift
From a plurality of divided areas of each photoelectric conversion element array 22,
An area selecting means for selecting a divided area used for measuring a subject distance according to a focal length of the photographing optical system having a variable focal length; and an image shift amount detected in the divided area selected by the area selecting means. A distance calculating means for calculating information on a distance to a subject based on the image data; and a divided area for detecting an image shift amount when no image shift amount is detected in all of the divided areas selected by the area selecting means. Area expanding means 1 for gradually expanding the divided area used for measuring the subject distance in the direction in which the photoelectric conversion element array 22 extends until is found, thereby achieving the above object. (2) In the distance measuring device according to the second aspect, the area expanding means 1
Thus, when the charge accumulation time of the photoelectric conversion element array 22 is within a predetermined time limit, the expansion of the divided area for subject distance measurement is executed. (3) The distance measuring device according to the third aspect is the area expanding means 1
Thus, the divided area for subject distance measurement is not extended to the divided areas at the left and right ends of the photoelectric conversion element array 2.

In the section of the means for solving the above-mentioned problem, a diagram of one embodiment is used for easy understanding of the description, but the present invention is not limited to this embodiment. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a passive distance measuring apparatus according to the present invention is applied to a lens shutter type autofocus camera will be described. FIG. 1 shows a configuration of a camera provided with a distance measuring device according to an embodiment. Illustration and description of camera devices not directly related to the distance measuring apparatus of the present invention are omitted.

The control device 1 is a microprocessor,
It performs control such as the photographing operation of the camera other than the distance measuring operation and various calculations. The control device 1 includes a CPU 11, a memory 12,
The control device 1 includes a timer 13, an A / D converter 14, and an input / output port 15. The control device 1 is connected to a charge storage type photoelectric conversion device 2, a photographing lens 3, and a finder 4.

The photoelectric conversion device 2 includes a light receiving lens 21, a light receiving unit 22, an amplifying unit 23, a storage unit 24, a transfer unit 25, and an output unit 26. The light receiving lens 21 constitutes the above-described distance measuring optical system. The light receiving unit 22 is composed of two sets of photoelectric conversion element rows (arrays) in which a plurality of photoelectric conversion elements are arranged on a straight line, and these two sets of photoelectric conversion element rows are juxtaposed at predetermined intervals in a direction perpendicular to the subject direction. Thus, a pair of photoelectric conversion element arrays is formed. A pair of subject light incident from a pair of left and right ranging windows (not shown) of the camera is guided onto a pair of photoelectric conversion element arrays of a light receiving unit 22 including a pair of light receiving lenses 21. The pair of photoelectric conversion element arrays of the light receiving section 22 receive the pair of subject lights and convert them into electric charges according to the light intensity. This charge is amplified by the amplifier 23 and stored in the storage 24. The charges stored in the storage unit 24 are sequentially transferred to the output unit 26 by the transfer unit 25, and are sequentially output from the output unit 26 to the control device 1.

The control device 1 inputs an output signal of the photoelectric conversion device 2 through an input / output port 15, converts the output signal into a digital signal by an A / D converter 14, and stores the digital signal in a memory 12 as a pair of subject image data. . The CPU 11
An image shift amount is detected by correlating a pair of subject image data, and a distance to the subject is calculated based on the image shift amount. That is, the distance to the subject is calculated by optical triangulation based on a pair of subject image data received by the charge storage type photoelectric conversion device 2. Further, a driving amount of a focusing lens for focusing the photographing lens 3 on a subject is calculated based on the calculated subject distance.

The taking lens 3 is a zoom lens whose focal length can be changed. The viewfinder 4 is a zoom finder that changes magnification in conjunction with zooming of the photographing lens 3, and a distance measurement frame indicating a distance measurement range is displayed so as to be superimposed on a subject image.

Here, the light receiving lens 21 of the photoelectric conversion device 2 constituting the distance measuring optical system, the photographing lens 3 as the photographing optical system, and the optical system of the finder 4 are provided separately and independently.

FIG. 2 shows the relationship between the photographing range and the distance measuring range in one embodiment. The shooting range (shooting screen) of the camera in the object scene changes according to the focal length of the shooting lens 3, and as shown in FIG. The larger the shooting range, the wider the shooting range. On the other hand, FIG.
The subject image 31 is displayed by the finder optical system as shown in FIG.

As described above, since the focal length of the optical system of the finder 4 changes according to the focal length of the taking lens 3, when the taking lens 3 is on the telephoto side, the optical system of the finder 4 also changes to the telephoto side. As shown in FIG. 2C, a subject image 31 in which a part of the object field is enlarged is formed on the finder 4 as shown in FIG. 2C. This finder image 31 corresponds to the subject image in the photographing range of the photographing lens 3 shown in FIG. Conversely, when the taking lens 3 is on the wide-angle side, the optical system of the finder 4 also changes magnification to the wide-angle side, and a subject image 31 in a wide field of view is formed as shown in FIG. 2D. This finder image 31 corresponds to the subject image in the photographing range on the wide-angle side of the photographing lens 3 shown in FIG. 2A.

FIG. 2C and FIG.
As shown in FIG. 7, a distance measurement frame 32 indicating the distance measurement range is displayed so as to be superimposed on the subject image. Since the distance measuring frame 32 is printed as a mask in the optical path of the optical system of the viewfinder 4, its size does not change even if the focal length of the taking lens 3 changes. However, the focal length of the distance measuring optical system (the light receiving lens 21 of the photoelectric conversion device 2) does not change according to the focal length of the photographing lens 3, but is fixed. Therefore,
Even when the optical system of the photographing lens 3 and the viewfinder 4 zooms to the wide-angle side to form an image of the subject in a wide range of the object field, on the contrary, zooms to the telephoto side to enlarge a part of the object field. Even when the subject image is formed, the actual distance measurement range in the object scene does not change at all.

Now, the photographing lens 3 and the finder 4
Is located on the wide-angle side, and the distance measurement frame 32 shown in FIG. 2D matches the actual distance measurement range. When the optical system of the photographing lens 3 and the finder 4 is zoomed to the telephoto side from this state, the photographing range of the photographing lens 3 becomes a range in which a part of the object field is enlarged, and the viewfinder image 31 becomes the photographing range of the photographing lens 3. The corresponding enlarged image is shown in FIG. 2c. At this time, a distance measurement frame 32 of the same size as that at the time of wide angle is displayed on the finder image 31.

Even if the optical system of the photographing lens 3 and the viewfinder 4 is zoomed to the telephoto side, the actual distance measuring range in the object field does not change because the focal length of the distance measuring optical system is fixed.
The range of the distance measurement frame 32 shown in FIG. 2D remains. When this actual distance measurement range is represented on the finder image 31 at the telephoto time shown in FIG. 2C, the actual distance measurement range is wider than the distance measurement frame 32 shown in FIG. 2C, and is further larger than the finder image 31 of FIG. 2C. Wide range.

As described above, since the distance measurement is performed in a range wider than the actual photographing range in the object scene, there is a problem in that the distance of a subject not intended by the photographer is measured as described above. Specifically, taking the telephoto shooting range shown in FIG. 2C as an example, the user wants to take an enlarged photograph of the person. The actual distance measurement range is the distance measurement frame 3 in FIG.
Since the range is even wider than 2, if there is another subject closer than the person in that range, the subject other than the person will be measured, and a close-up photograph of the out-of-focus person will be taken. .

Therefore, in this embodiment, as the focal length of the photographing lens 3 becomes closer to the telephoto side, the actual distance measurement range is reduced, and the actual distance measurement range is changed to the finder image 31.
To be the same as the range of the distance measurement frame 32 superimposed and displayed.

Now, it is assumed that the actual distance measurement range of the taking lens 3 at the wide angle shown in FIG. 2B coincides with the range of the distance measurement frame 32 superimposed and displayed on the finder image 31 at the wide angle shown in FIG. 2D. I do. From this state, when the optical system of the photographing lens 3 and the finder 4 is zoomed to the telephoto side, FIG.
The actual distance measurement range at the time of telephoto so that the actual distance measurement range at the time of telephotography of the photographing lens 3 shown in FIG. 2B is the same as the range of the distance measurement frame 32 superimposed and displayed on the finder image 31 shown in FIG. To narrow.

Of course, even when the focal length of the optical system of the photographing lens 3 and the finder 4 is between the wide-angle end and the telephoto end, the actual distance measurement range of the distance measurement frame 32 superimposed on the finder image 31 is displayed. The subject distance measurement range of the photoelectric conversion device 2 is determined according to the focal length of the photographing lens 3 so as to always match the range.

FIG. 3 shows the light receiving lens 21 of the photoelectric conversion device 2.
And FIG. With reference to this figure, a method of changing the distance measurement range according to the embodiment will be described. The light receiving lens 21 includes a pair of left and right lenses 21a and 21b, and the light receiving unit 22 includes a pair of left and right photoelectric conversion element arrays 22a and 22b.
Having. As described above, the camera is provided with a pair of left and right distance measurement windows (not shown), and a pair of subject light enters the camera from the distance measurement windows. One object light incident from the left distance measuring window is guided to the left photoelectric conversion element array 22a by the left light receiving lens 21a, and the other object light incident from the right distance measuring window is right irradiated by the right light receiving lens 21b. To the photoelectric conversion element array 22b.

In this embodiment, the left and right photoelectric conversion element arrays 22a and 22b are divided into eight areas AREA0 to AREA7 (hereinafter referred to as distance measuring areas) for every five photoelectric conversion elements. Then, the left and right photoelectric conversion element arrays 22a and 22b respectively perform a correlation operation for each ranging area to detect an image shift amount.

Then, as shown in FIG.
At the time of wide angle, all the distance measurement areas AREA0 to AREA7 are selected, and the subject distance is calculated based on the image shift amount of the selected areas AREA0 to AREA7. This selection area AREA0-ARE
A7 corresponds to the distance measurement range indicated by the distance measurement frame 32 at the time of wide angle of the photographing lens 3 shown in FIG. 2D.

On the other hand, when the photographing lens 3 is telephoto, the center 4
The distance measuring areas AREA2 to AREA5 are selected, and the subject distance is calculated based on the image shift amounts of the selected areas AREA2 to AREA5. The selection areas AREA2 to AREA5 correspond to the distance measurement range indicated by the distance measurement frame 32 in the telephoto state of the photographing lens 3 shown in FIG. 2C. When the focal length of the photographing lens 3 is between the wide-angle end and the telephoto end, the distance measuring area is evenly selected from the center to the left and right according to the focal length of the photographing lens 3.

The number of areas divided by the photoelectric conversion device and the number of photoelectric conversion elements in each distance measuring area are not limited to this embodiment.

FIG. 4 is a flowchart showing the distance measurement processing, and FIG. 5 is a flowchart showing the distance measurement value search processing. The operation of the embodiment will be described with reference to these flowcharts. When the shutter release button (not shown) is half-pressed, the CPU 11 of the control device 1 starts the distance measurement process shown in FIG.

In step 41, sensing is performed.
The photoelectric conversion device 2 is controlled, and a pair of light receiving units 22a and 22b are controlled.
Is converted into electric charges corresponding to the light intensity, and the electric charges are amplified by the amplifier 23 and accumulated in the accumulator 24. Then, the accumulated charges are sequentially transferred to the output unit 26 by the transfer unit 25, and are sequentially output from the output unit 26 to the control device 1. The control device 1 converts an output signal of the photoelectric conversion device 2 into a digital signal by the A / D converter 14 and stores a pair of subject data in the memory 12.

The control device 1 controls the accumulation of electric charges in the photoelectric conversion device 2 based on the accumulation level and the accumulation time. After the start of charge accumulation in the photoelectric conversion device 2, it is confirmed whether or not the accumulation level has reached a predetermined level, and when the accumulation level has reached the predetermined level, the charge accumulation in the photoelectric conversion device 2 is terminated. If the accumulation level has not reached the predetermined level, it is confirmed whether or not the time measured by the timer 13 for measuring the accumulation time has reached a predetermined accumulation limit time. If the time counted by the timer 13 has not reached the predetermined accumulation limit time, the charge accumulation is continued, and if the time counted by the timer 13 reaches the accumulation limit time, the charge accumulation is terminated, and the accumulation limit time is exceeded. The reason why the charge accumulation is controlled by the accumulation limit time is that the accumulation time becomes long when the subject is dark, so that an appropriate time limit is set and the accumulation of the charge is stopped halfway.

In step 42, a correlation between a pair of subject data stored in the memory 12 is calculated for each of the distance measurement areas AREA0 to AREA7 to detect a distance measurement value (image shift amount). In a succeeding step 43, a distance measuring area for measuring a subject distance is selected from the distance measuring areas AREA0 to AREA7 according to the focal length of the photographing lens 3, and whether an image shift amount is obtained in each of the selected distance measuring areas. Search for Details of the distance measurement value search processing will be described later. If the image shift amount is obtained in any of the selected areas, the process proceeds from step 44 to step 45. If the image shift amount is not obtained in all of the selected areas, the process proceeds from step 44 to 47.

If the image shift amount has been obtained in any of the distance measurement areas selected according to the focal length of the photographing lens 3, the image shift amount is calculated for each of the distance measurement areas for which the image shift amount was obtained in step 45. The subject distance based on the distance measuring optical system is calculated based on the distance. In the following step 46, based on the subject distance calculated for each ranging area, a final subject distance based on the ranging optical system is obtained in accordance with a predetermined algorithm such as a close-priority algorithm.

In step 47, the final object distance based on the distance measuring optical system is converted into the object distance based on the photographing lens 3. As described above, the lens shutter type camera according to the embodiment has a photographing optical system (photographing lens 3).
And the distance measuring optical system (the light receiving lens 21 of the photoelectric conversion device 2) are provided separately and independently, and the object distance of the distance measuring optical system does not always match the object distance of the photographing optical system. Therefore, it is necessary to convert the subject distance of the ranging optical system into the subject distance of the photographing optical system.

If no image shift amount is obtained in all the distance measurement areas selected in step 44,
In step 47, a predetermined value is set for the subject distance based on the photographing optical system.

In this embodiment, an example is shown in which the distance to the subject based on the distance measuring optical system or the photographing optical system is calculated based on the image shift amount. This subject distance is calculated based on the actual distance [m ], For example, a lens movement amount [μ] corresponding to a subject distance in a distance measuring optical system or a photographing optical system.
m], etc.

FIG. 5 is a flowchart showing the distance measurement value search processing in step 43 of FIG. The details of the distance measurement value search processing will be described with reference to this flowchart. Step 5
At 01, an area for starting a search is set from the distance measurement areas selected according to the focal length of the photographing lens 3. In the following step 502, an area for ending the search is set from the distance measurement areas selected according to the focal length of the photographing lens.

For example, when the photographing lens 3 is on the wide-angle side, AREA0 to AREA7 are selected as the distance measurement areas for measuring the subject distance, AREA0 is set as a search start area, and AREA7 is set as a search end area. When the taking lens 3 is on the telephoto side, AREA2 to AREA5 are displayed in the distance measurement area for measuring the subject distance.
Is selected, and AREA2 is set as a search start area, and AREA5 is set as a search end area. Then, in step 503, the number of the search start area is set in the area counter AREA.

In step 504, it is confirmed whether or not a distance measurement value (image shift amount) has been obtained in the distance measurement area of the area counter AREA.
Proceed to step 1. If the image shift amount has not been obtained, step 5
Go to 05.

If a distance measurement value (image shift amount) has been obtained in any of the selected areas, it is set in step 511 that there is a distance measurement value, and the process returns to step 44 of FIG. On the other hand, if the image shift amount cannot be obtained, step 505 is executed.
The area counter AREA is incremented, and the process proceeds to step 506. In step 506, the area counter AR
It is determined whether the EA has reached the search end area. If the EA has reached the search end area, the process proceeds to step 507. If the EA has not reached the search end area, the process returns to step 504.

If the area counter AREA has not reached the search end area, at step 504, the image shift amount of the next selected area is confirmed. If the area counter AREA has exceeded the search end area, it is checked in step 507 whether the charge accumulation in sensing has exceeded the time limit. If the charge accumulation time exceeds the time limit, the process proceeds to step 512; otherwise, the process proceeds to step 508. If the charge accumulation time exceeds the time limit, in step 512, no distance measurement value is set, and the process returns to step 44 in FIG. On the other hand, if the charge accumulation time does not exceed the time limit, the search start area is set to AREA0 in step 508.
Check whether or not. If the selection start area is AREA0, the process proceeds to step 512, where no distance measurement value is set, and the process returns to step 44 in FIG.

On the other hand, if the search start area is not AREA0, 1 is subtracted from the search start area in step 509,
In subsequent step 510, 1 is added to the search end area.
Then, the process returns to step 503 to repeat the above-described search processing. That is, the selection area is extended one by one to the left and right in the direction in which the photoelectric conversion device 2 extends, and the distance measurement value is searched again in all the selection areas including the extended selection area.

As described above, the area in which the distance measurement value (the amount of image shift) is obtained is searched from the distance measurement areas selected in accordance with the focal length of the photographing lens 3, and the distance measurement in which the distance measurement value is obtained is obtained. When an area is found, the search processing is terminated at that point in time assuming that there is a distance measurement value.

On the other hand, if the distance measurement value cannot be obtained in all the selected areas among the distance measurement areas selected in accordance with the focal length of the photographing lens 3, the selected areas are gradually expanded. It expands one by one to the left and right in the direction of presence, and performs a search again for the distance measurement value in all the selected areas including the expanded selected area. As a result, it is possible to avoid a situation in which it is not possible to measure the distance to the main subject intended by the photographer by using the distance measurement values at both ends of the photographing screen or outside the photographing screen according to the current focal length of the photographing lens 3, When the distance measurement range according to the focal length of the photographing lens 3 is expanded, the deviation between the distance of the main subject intended by the photographer and the measurement distance can be suppressed to a minimum.

The selection area is expanded on condition that the charge accumulation time is within the time limit (when the subject is bright). If the subject is darker than the charge accumulation time exceeds the time limit, a distance measurement value cannot be obtained in the distance measurement area selected according to the focal length of the photographing lens 3 in many cases.
By expanding the selection area and adopting the distance measurement values of both end portions of the photographing screen or the distance measuring area outside the photographing screen, the probability that the photographer cannot measure the distance to the main subject intended by the photographer increases. Therefore, the selection area is expanded only when the subject is bright, and such a problem is prevented.

The subject distance measuring area is not extended to the distance measuring areas at the left and right ends of the photoelectric conversion device 2. If the object distance measurement area is extended to the distance measurement areas at the left and right ends of the photoelectric conversion device 2 when the distance measurement value is not found, the distance measurement is performed at both ends of the shooting screen or the outside of the shooting screen according to the focal length of the shooting lens 3. If the value is adopted, the main subject intended by the photographer cannot be measured. Therefore, even when the distance measurement value is not found, the object distance measurement area is not extended to the left and right end distance measurement areas, and such a problem is prevented.

In the above-described embodiment, the taking lens 3
If there is no distance measurement value in the selection area corresponding to the focal length of the area, the selection area is extended one by one to the left and right in the extending direction of the photoelectric conversion device 2, and the distance measurement is performed in all the selection areas including the extended selection area Although the example in which the value is searched again has been described, only the expanded ranging area may be searched. When performing the process of searching for the distance measurement value using the software form of the microcomputer, the process of searching only the expanded distance measurement area is:
Since the processing is more complicated than the processing of re-searching all the selected areas including the expanded area, the processing program of the microcomputer is simpler in the reconstruction plan processing of the above-described embodiment.

[0050]

(1) As described above, according to the first aspect of the present invention, the subject distance is selected from the plurality of divided areas of the photoelectric conversion element array in accordance with the focal length of the variable focal length imaging optical system. When selecting the divided area to be used for the measurement and calculating the information on the distance to the subject based on the image shift amount detected in the selected divided area, the selected area is selected according to the focal length of the imaging optical system. If the image shift amount is not detected in all of the divided regions, the divided regions used for measuring the subject distance are gradually changed in the extending direction of the photoelectric conversion element array until the divided region in which the image shift amount is detected is found. Since it is expanded, it is possible to avoid the situation where it is not possible to measure the main subject intended by the photographer by using the distance measurement value at both ends of the shooting screen or outside the shooting screen according to the focal length of the shooting optical system And When the distance measurement range according to the focal length of the photographing optical system is extended, the deviation between the distance of the main subject intended by the photographer and the measurement distance can be minimized. (2) According to the invention of claim 2, when the charge accumulation time of the photoelectric conversion element array is within a predetermined time limit,
The extension of the divided area for subject distance measurement is performed. If the subject is darker than the charge accumulation time exceeds the time limit, the distance measurement value cannot be obtained in the divided area selected according to the focal length of the imaging optical system. By adopting the distance measurement values of both end portions or the divided areas outside the shooting screen, the probability that the main subject intended by the photographer cannot be measured is increased. Therefore, such an inconvenience can be prevented by expanding the selection area only when the subject is bright. (3) According to the invention of claim 3, the divided area for subject distance measurement is not extended to the divided areas on the left and right ends of the photoelectric conversion element array. If the subject distance measurement area is extended to the left and right end divided areas of the photoelectric conversion element array when the distance measurement value is not found, the distance measurement value at both ends of the shooting screen or outside the shooting screen according to the focal length of the shooting optical system And it becomes impossible to measure the distance of the main subject intended by the photographer. Therefore, even when the distance measurement value is not found, such a problem can be prevented by not extending the subject distance measurement area to the left and right end divided areas.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment.

FIG. 2 is a diagram illustrating a relationship between a photographing range and a distance measurement range.

FIG. 3 is a diagram illustrating a method of changing a distance measurement range.

FIG. 4 is a flowchart illustrating a distance measuring process according to the embodiment;

FIG. 5 is a flowchart illustrating a distance measurement value search process according to one embodiment;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 control device, 2 photoelectric conversion device 3 shooting lens 4 finder 11 CPU, 12 memory, 13 timer 14 A / D converter 15 input / output port 21, 21 a, 21 b light receiving lens 22 light receiving unit 22 a, 22 b photoelectric conversion element array 23 amplifying unit 24 storage unit 25 transfer unit 26 output unit

Claims (3)

[Claims] A pair of charge storage type photoelectric conversion elements each comprising a plurality of photoelectric conversion elements; a distance measuring optical system having a fixed focal length for guiding a pair of subject light to said pair of photoelectric conversion elements; Each photoelectric conversion element array is divided into a plurality of regions, correlation calculation means for performing a correlation calculation for each divided region and detecting an image shift amount, and among the plurality of divided regions of each of the photoelectric conversion element arrays,
Area selecting means for selecting a divided area to be used for measuring a subject distance according to the focal length of the imaging optical system having a variable focal length; and, based on an image shift amount detected in the divided area selected by the area selecting means. A distance calculating unit that calculates information on a distance to the subject; and, if an image shift amount is not detected in all of the divided regions selected by the region selecting unit, until a divided region in which the image shift amount is detected is found. A distance measuring device comprising: a region expanding means for gradually expanding a divided region used for measuring a subject distance in an extending direction of the photoelectric conversion element array. 2. A distance measuring apparatus according to claim 1, wherein said area expanding means expands a divided area for subject distance measurement when the charge accumulation time of said photoelectric conversion element array is within a predetermined time limit. A distance measuring device that performs the following. 3. A distance measuring apparatus according to claim 1, wherein said area expanding means does not extend the divided area for subject distance measurement to the divided areas on the right and left ends of said photoelectric conversion element array. Characteristic ranging device.