JP2022128517A - ranging camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ranging camera capable of calculating a distance to a subject without using a translation parallax between a plurality of images.

SOLUTION: A ranging camera includes: a first optical system OS1; a second optical system OS2; an imaging portion S for imaging a first subject image and a second subject image; a distance calculating portion 4 that calculates a distance to a subject 100 on the basis of the first subject image and the second subject image; a first lens drive portion AF1 for executing focus operation of the first optical system OS1; and a second lens drive portion AF2 for executing focus operation of the second optical system OS2. Changes in the magnification of the first subject image differs from changes in the magnification of the second subject image. An image magnification ratio between the first subject image and the second subject image changes according to a distance to the subject. A focal distance of the first optical system and a focal distance of the second optical system are different from each other.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates generally to a rangefinder camera for measuring the distance to an object, and more specifically to a rangefinder camera formed by at least two optical systems that differ from each other in the change in magnification of an object image according to the distance to the object. Also, the present invention relates to a distance measuring camera that measures the distance to a subject based on the image magnification ratio of at least two subject images.

2. Description of the Related Art In recent years, distance measuring cameras have been proposed that measure the distance to a subject by taking an image of the subject. Such a distance measuring camera is a stereo camera having two or more pairs of an optical system for forming an image of light from an object and an image sensor for converting the object image formed by the optical system into an image signal. A pattern comprising a camera-type ranging camera, a projector for irradiating a subject with light of a certain pattern (for example, a lattice pattern), and an imaging system for imaging the subject illuminated by the light of a certain pattern An irradiation-type ranging camera is known (see, for example, Patent Document 1).

A stereo camera type distance measuring camera acquires a plurality of images having different translational parallaxes by using a combination of two or more pairs of an optical system and an imaging device, and based on the translational parallaxes between the acquired plurality of images, a subject is detected. Calculate the distance to In order to accurately calculate the distance to the object based on the translational parallax between a plurality of images, it is necessary to obtain a large translational parallax. Therefore, it is necessary to dispose two or more optical systems at a large distance in one rangefinder camera, which increases the size of the rangefinder camera.

In the pattern irradiation type ranging camera, the distance to the subject is measured by irradiating the subject with a predetermined pattern of light and analyzing the distortion of the predetermined pattern projected onto the subject. For this reason, the pattern irradiation type rangefinder camera requires a projector for irradiating the subject with light of a certain pattern, resulting in a large-scale configuration of the rangefinder camera.

JP 2013-190394 A

The present invention has been made in view of the above-mentioned conventional problems, and its object is to determine the distance to a subject without using translational parallax between a plurality of images and without illuminating the subject in a fixed pattern. To provide a distance measuring camera capable of calculating.

Such objects are achieved by the present invention of the following (1) to (9).
(1) a first optical system for condensing light from a subject and forming a first subject image;
a second optical system for condensing the light from the subject and forming a second subject image;
an imaging unit for capturing the first subject image formed by the first optical system and the second subject image formed by the second optical system;
a distance calculation unit for calculating a distance to the subject based on the first subject image and the second subject image captured by the imaging unit;
a first lens driving unit for performing a focusing operation of the first optical system;
a second lens driving unit for executing a focusing operation of the second optical system;
The distance calculation unit calculates the distance to the subject based on an image magnification ratio between the magnification of the first subject image and the magnification of the second subject image,
the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image varies according to the distance to the subject;
The first optical system and the second optical system are configured such that the focal length of the first optical system and the focal length of the second optical system are different from each other. A change in the magnification of the first subject image according to the distance to the subject is different from a change in the magnification of the second subject image according to the distance to the subject. A rangefinder camera characterized by:

(2) A one-to-one relationship is established between the value of the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image and the distance to the subject. The distance measuring camera according to (1) above.

(3) The distance calculation unit may at least:
the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image;
the focal length of the first optical system;
The distance measuring camera according to (1) or (2) above, wherein the distance to the subject is calculated using the focal length of the second optical system.

(4) The first optical system, the second optical system, and the image capturing section are configured to operate in an initial state in which the first lens driving section and the second lens driving section are not performing the focusing operation. , are arranged to be in focus at infinity,
The distance calculator further uses the depth parallax in the optical axis direction between the front principal point of the first optical system in the initial state and the front principal point of the second optical system in the initial state. The distance-measuring camera according to (3) above, which calculates the distance to the subject.

(5) a first optical system for condensing light from a subject and forming a first subject image;
a second optical system for condensing the light from the subject and forming a second subject image;
an imaging unit for capturing the first subject image formed by the first optical system and the second subject image formed by the second optical system;
a distance calculation unit for calculating a distance to the subject based on the first subject image and the second subject image captured by the imaging unit;
an image magnification ratio between the magnification of the first subject image and the magnification of the second subject image varies according to the distance to the subject;
The distance calculation unit is configured to at least
the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image;
a focal length of the first optical system;
and a focal length of the second optical system to calculate the distance to the subject.

(6) The distance measuring camera according to (5) above, wherein the focal length of the first optical system and the focal length of the second optical system are different from each other.

(7) further comprising: a first lens driving section for executing a focusing operation of the first optical system; and a second lens driving section for executing a focusing operation of the second optical system. ,
The first optical system, the second optical system, and the imaging section are configured to be at infinity in an initial state in which the first lens driving section and the second lens driving section are not performing the focusing operation. It is arranged so that the focus is on the
The distance calculator further uses the depth parallax in the optical axis direction between the front principal point of the first optical system in the initial state and the front principal point of the second optical system in the initial state. The distance measuring camera according to (5) or (6) above, which calculates the distance to the subject by

ここで、ａは、前記被写体までの前記距離であり、ＭＲは、前記像倍比であり、ｆ_１は、前記第１の光学系の前記焦点距離であり、ｆ_２は、前記第２の光学系の前記焦点距離であり、Ｄは、前記初期状態における前記第１の光学系の前記前側主点と、前記初期状態における前記第２の光学系の前記前側主点との間の前記光軸方向の前記奥行視差である。 (8) The distance-measuring camera according to (7) above, wherein the distance calculator calculates the distance to the subject using the following equation (1) or (2).

Here, a is the distance to the subject, MR is the image magnification ratio, f1 is the focal length of the _first optical system, and f2 is the _second is the focal length of the optical system, and D is the light between the front principal point of the first optical system in the initial state and the front principal point of the second optical system in the initial state It is the depth parallax in the axial direction.

(9) A one-to-one relationship is established between the value of the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image and the distance to the subject. The distance measuring camera according to any one of (5) to (8) above.

The distance measuring camera of the present invention uses two optical systems configured so that the change in the magnification of the subject image according to the distance to the subject is different from each other. Based on the image magnification ratio (magnification ratio), the distance to the object can be measured. Therefore, in the distance measuring camera of the present invention, unlike conventional stereo camera type distance measuring cameras that use translational parallax between a plurality of images, there is no need to ensure a large translational parallax. The distance to the object can be calculated accurately even if the object is placed in the same position. As a result, it is possible to reduce the size of the distance measuring camera as compared with conventional stereo camera type distance measuring cameras. Moreover, according to the present invention, since it is not necessary to design a ranging camera in consideration of translational parallax, the degree of freedom in designing a ranging camera can be increased.

Further, unlike the conventional pattern irradiation type range finding camera, the range finding camera of the present invention does not need to use a special light source such as a projector that irradiates a subject with light of a predetermined pattern. Therefore, the system configuration of the ranging camera can be simplified. As a result, it is possible to reduce the size, power consumption, and cost of the ranging camera as compared with the conventional ranging camera of the pattern irradiation method.

FIG. 4 is a diagram for explaining the distance measurement principle of the distance measurement camera of the present invention; The image magnification ratio between the magnification of the first subject image formed by the first optical system shown in FIG. 1 and the magnification of the second subject image formed by the second optical system shown in FIG. is a graph for explaining that it changes according to the distance of . 7 is a graph for explaining a case where the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image does not change according to the distance to the subject; 1 is a block diagram schematically showing a ranging camera according to a first embodiment of the invention; FIG. 5 is a diagram schematically showing a configuration example of a first optical system and a second optical system shown in FIG. 4; FIG. FIG. 4 is a block diagram schematically showing a distance measuring camera according to a second embodiment of the present invention; FIG. FIG. 11 is a block diagram schematically showing a ranging camera according to a third embodiment of the present invention; FIG. 12 is a block diagram schematically showing a distance measuring camera according to a fourth embodiment of the present invention; FIG. FIG. 11 is a block diagram schematically showing a distance measuring camera according to a fifth embodiment of the present invention; FIG. 11 is a block diagram schematically showing a distance measuring camera according to a sixth embodiment of the present invention; FIG. 12 is a block diagram schematically showing a ranging camera according to a seventh embodiment of the present invention; FIG. 20 is a block diagram schematically showing a distance measuring camera according to an eighth embodiment of the present invention; 4 is a flow chart for explaining a ranging method executed by the ranging camera of the present invention;

First, the principle for calculating the distance to the subject, which is used in the distance measuring camera of the present invention, will be described.

As is well known, the magnification m of a subject image formed by an optical system is determined by the distance (object distance) a from the front principal point (front principal plane) of the optical system to the subject, and the rear principal point of the optical system It can be calculated by the following equations (1) and (2) using the distance b from (the rear principal surface) to the imaging position of the subject image and the focal length f of the optical system.

When the imaging plane of the imaging element is at the imaging position of the subject image (that is, in the case of best focus), as is clear from the above equation (2), the subject image formed on the imaging plane of the imaging element by the optical system is a function of the distance a from the front principal point of the optical system to the subject and the focal length f of the optical system. When the focal length f of the optical system is fixed, the magnification m of the subject image changes according to the distance a to the subject.

Here, as shown in FIG. 1, it is assumed that the same subject 100 is imaged using two imaging systems IS1 and IS2. The first imaging system IS1 includes a first optical system OS1 that collects light from the subject 100 to form a first subject image, and at least one lens (for example, , focus lens) to perform the focus operation (or autofocus operation) of the first optical system OS1, and the first optical system OS1. and a first image sensor S1 for capturing a first subject image. The second imaging system IS2 includes a second optical system OS2 that collects light from the subject 100 and forms a second subject image, and at least one lens (for example, , focus lens) to realize the focus operation (or autofocus operation) of the second optical system OS2, and the second optical system OS2. and a second image sensor S2 for capturing a second subject image. Also, as is clear from FIG. 1, the optical axis of the first optical system OS1 of the first image sensor S1 and the optical axis of the second optical system OS2 of the second image sensor S2 are parallel. , does not match. In the illustrated embodiment, for simplification of explanation, the first optical system OS1 is arranged such that the front principal point and the rear principal point of the first optical system OS1 are at the center position of the first optical system OS1. Similarly, the second optical system OS2 is such that the front principal point and the rear principal point of the second optical system OS2 are at the center position of the second optical system OS2. is shown schematically as

The first optical system OS1 and the second optical system OS2 are configured to have different focal lengths f ₁ and f ₂ , respectively. Further, the first optical system OS1 and the first imaging element S1 perform a focusing operation by driving (extending) at least one of the lenses that constitute the first optical system OS1 by the first lens driving unit AF1. In the initial state when not executed, it is arranged so that the focus is at infinity. That is, in FIG. 1, in the initial state where the first optical system OS1 is represented by a dotted line, the distance from the rear principal point of the first optical system OS1 to the imaging surface of the first imaging element S1 is , equal to the focal length f1 of the _first optical system OS1.

Similarly, the second optical system OS2 and the second imaging device S2 perform a focus operation by driving (extending) at least one of the lenses that constitute the second optical system OS2 by the second lens driving unit AF2. In the initial state before executing That is, in FIG. 1, in the initial state where the second optical system OS2 is represented by a dotted line, the distance from the second optical system OS2 to the imaging surface of the second imaging element S2 is the second optical system OS2. It is equal to the focal length f2 of system _OS2 .

Also, the first optical system OS1 and the second optical system OS2 are the front principal point of the first optical system OS1 of the first imaging system IS1 in the initial state and the second principal point of the second imaging system IS2 in the initial state. 2 and the front principal point of the optical system OS2, there is a depth parallax D in the optical axis direction.

When subject 100 is positioned at an arbitrary distance when subject 100 is imaged by first imaging system IS1, subject 100 is not in focus in the initial state (because defocus exists). A focus operation of the first optical system OS1 is performed by the lens driving unit AF1. At this time, at least one lens (for example, a focus lens) constituting the first optical system OS1 is extended by the first lens driving unit AF1, and the front principal point and the rear principal point of the first optical system OS1 are moved. The position of the point changes. Here, it is assumed that the amount of shift of the front principal point and the rear principal point of the first optical system OS1 due to the focusing operation is _Δb1 . Let a be the distance from the front principal point of the first optical system OS1 to the object 100 after the focus operation.

Similarly, when subject 100 is imaged by second imaging system IS2, if subject 100 is positioned at an arbitrary distance, subject 100 is not in focus in the initial state (because defocus exists). A focus operation of the second optical system OS2 is performed by the second lens driving unit AF2. At this time, at least one lens (for example, a focus lens) constituting the second optical system OS2 is extended by the second lens driving unit AF2, and the front principal point and the rear principal point of the second optical system OS2 are moved. The position of the point changes. Let Δb2 be the shift amount of the front principal point and the rear principal point of the _second optical system OS2 due to the focusing operation. Also, let A be the distance from the front principal point of the second optical system OS2 to the object 100 after the focus operation.

Here, as is clear from FIG. 1, the distance A from the front principal point of the second optical system OS2 to the subject 100 is calculated using the distance a from the front principal point of the first optical system OS1 to the subject 100. , can be expressed by the following formula (3).

Here, in a state in which the object 100 located at a distance a from the front principal point of the first optical system OS1 is in focus, is equal to _{1/f 1 −1} /a from the lens formula. Therefore, the shift amount Δb ₁ of the front principal point and the rear principal point of the first optical system OS 1 is determined by the distance b ₁ and the rear principal point of the first optical system OS 1 in focus at infinity to the imaging surface of the first imaging element S1 (that is, the focal length f ₁ of the first optical system OS1) can be expressed by the following equation (4).

Similarly, in a state in which the object 100 located at a distance A from the front principal point of the second optical system OS2 is in focus, is equal to _{1/f 2 −1} /A from the lens formula. Therefore, the shift amount _Δb2 of the front principal point and the rear principal point of the _second optical system OS2 is the distance b2 and the rear principal point to the imaging surface of the second imaging element S2 (that is, the focal length f ₂ of the second optical system OS2), the following equation (5) can be obtained.

Further, the magnification m1 of the first subject image formed on the imaging surface of the first imaging element S1 by the _first optical system OS1 and the magnification m1 on the imaging surface of the second imaging element S2 by the second optical system OS2 The magnification m ₂ of the second object image formed in can be expressed by the following equations (6) and (7), respectively, using the above equation (2).

Therefore, the magnification m1 of the _first subject image formed on the imaging surface of the first imaging element S1 by the first optical system OS1 and the imaging surface of the second imaging element S2 by the second optical system OS2 The image magnification ratio MR to the magnification _m2 of the second object image formed above can be expressed by the following equation (8) from the above equations (6) and (7).

Also, by summarizing Δb2 from the above equations (3) and (5), it is possible to obtain a _quadratic equation for _Δb2 such as the following equation (9).

In the above equation (9), X=a+D+ _Δb1 is used for simplification of the equation. X can be represented by the following formula (10) using the above formula (4). Also, P in the following formula (10) is f ₁ -D.

The following equation (11) can be obtained by solving the _quadratic equation for Δb2 in the above equation (9).

By transforming the above equation (3) for A using the above equation (10) for X and the above equation (11) for _Δb2 , the following equation (12) can be obtained.

By substituting the above equation (12) for A into the above equation (8) for the image magnification ratio MR to simplify the image magnification ratio MR, the following equation (13) is obtained. Also, K in the following formula (13) is f ₂ /f ₁ .

By substituting the above equation (10) regarding X into the above equation (13) regarding the image magnification ratio MR and using K=f ₂ /f ₁ , the distance a can be rearranged to obtain the two equations represented by the following equation (14). The following equation is obtained. Also, L in the following formula (14) is 2f ₂ /(MR·f ₁ ).

Solving the quadratic equation of the above formula (14) and using the above relationships of P=f ₁ −D and L=2f ₂ /(MR·f ₁ ) yields the following general formulas (15) and (16) Two solutions are obtained for the distance a represented by .

Which of the two solutions for the distance a represented by the above general formulas (15) and (16) is appropriate for the distance a depends on the focal length f1 of the _first optical system OS1 and the first ₂ and the focal length f2 of the optical system OS2. That is, based on the following conditions (1) to (3), it is determined which of the two solutions represented by the general formulas (15) and (16) is appropriate for the distance a. be judged.

(1) When f ₂ ≤ f ₁ When the relationship between the focal length f ₁ of the first optical system OS1 and the focal length f ₂ of the second optical system OS2 satisfies f ₂ ≤ f ₁ , the above The solution represented by general formula (15) is suitable as the distance a.

(2) When f ₂ ≧f ₁ +D When the relationship between the focal length f ₁ of the first optical system OS1 and the focal length f ₂ of the second optical system OS2 satisfies f ₂ ≧f ₁ +D , the solution represented by the above general formula (16) is appropriate as the distance a.

(3) When f ₁ <f ₂ <f ₁ +D The relationship between the focal length f ₁ of the first optical system OS1 and the focal length f ₂ of the second optical system OS2 is f ₁ <f ₂ < If f ₁ +D, further conditioning is required. That is, when the condition of f ₁ <f ₂ <f ₁ +D is satisfied, the above general formulas (15) and (16) are further based on the following conditions (3-1) to (3-3): Which of the two solutions represented by is appropriate for the distance a changes.

(3-1) When L ² −2L≦0 When L ² −2L, which is the coefficient of the term a ² in the above formula (14), is 0 or less, the solution represented by the above general formula (16) is the distance It is suitable as a.

On the other hand, when L ² −2L, which is the coefficient of the term a ² in the above formula (14), is greater than 0 (when L ² −2L>0), it is a function of the distance a and is expressed by the above formula (14). Depending on the differential value g'(a) of the position g(a) of the axis of the quadratic curve, which one of the two solutions represented by the above general formulas (15) and (16) is the distance Whether or not it is suitable as a changes. The position g(a) of the axis of the quadratic curve represented by the above equation (14) is represented by the following equation (17).

(3-2) When L ² -2L>0 and g′(a)≦0 L ² -2L, which is the coefficient of the term a ² in the above formula (14), is greater than 0, and the above formula When the differential value g'(a) of the axis position g(a) of the quadratic curve represented by (14) is 0 or less, the solution represented by the above general formula (16) is appropriate as the distance a. .

(3-3) When L ² -2L>0 and g′(a)>0 L ² -2L, which is the coefficient of the term a ² in the above formula (14), is greater than 0, and the above formula When the differential value g'(a) of the axis position g(a) of the quadratic curve represented by (14) is greater than 0, the solution represented by the above general formula (15) is appropriate as the distance a. .

In the above general formulas (15) and (16), the focal length f ₁ of the first optical system OS1, the focal length f 2 of the second optical system OS2, and the front principal distance f ₂ of the first optical system OS1 in the initial state. The depth parallax D between the point and the front principal point of the second optical system OS2 in the initial state is a fixed value determined when constructing and arranging the first optical system OS1 and the second optical system OS2. is. Therefore, if the image magnification ratio MR can be obtained, the distance a can be uniquely calculated.

FIG. 2 shows the magnification of the first subject image formed on the imaging surface of the first image sensor S1 by the first optical system OS1, calculated based on the above general formula (15) or (16). The image magnification ratio MR between m1 and the magnification _m2 of the _second object image formed on the imaging surface of the second image sensor S2 by the second optical system OS2, and the distance a to the object 100 An example relationship is shown. As is clear from FIG. 2, the distance a to the subject 100 can be specified from the value of the image magnification ratio MR.

On the other hand, the image magnification ratio MR can be calculated by the following formula (18). In the following formula (18), sz is the actual size (height or width) of the subject 100, and Y1 is the _first image formed on the imaging surface of the first imaging element S1 by the first optical system OS1. 1 is the size (image height or image width) of the subject image, and Y ₂ is the size (image height or image width) of the second subject image formed on the imaging surface of the second image sensor S2 by the second optical system OS2. image width).

The size Y1 of the _first subject image and the size Y2 of the _second subject image are determined by the fact that the first image sensor S1 and the second image sensor S2 capture the first subject image and the second subject image. can be calculated from the image signal of the first subject image and the image signal of the second subject image obtained by . Therefore, from the image signal of the first subject image and the image signal of the second subject image obtained by actually imaging the subject 100 using the first imaging system IS1 and the second imaging system IS2, the second The size Y1 of the _first subject image and the size Y2 of the _second subject image are actually measured, and based on this, the image magnification ratio between the magnification m1 of the _first subject image and the magnification _m2 of the second subject image MR can be obtained.

According to the principle described above, the distance measuring camera of the present invention determines the magnification m ₁ of the first object image and the size Y ₂ of the second object image based on the actually measured size Y ₁ of the first object image and size Y 2 of the second object image. ₂ , and furthermore, using the calculated image magnification ratio MR, the distance a from the front principal point of the first optical system OS1 to the subject 100 is calculated. .

As is clear from the above equation (13) regarding the image magnification ratio MR, the focal length f1 of the _first optical system OS1 and the focal length f2 of the _second optical system OS2 are _equal (f1=f2 ₌ f) and when there is no depth parallax D between the front principal point of the first optical system OS1 in the initial state and the front principal point of the second optical system OS2 in the initial state (D=0, i.e. , a=A), the image magnification ratio MR does not hold as a function of the distance a and is a constant. In this case, as shown in FIG. 3, the change in the magnification m1 of the first object image according to the distance a to the object ₁₀₀ changes the magnification _m2 of the second object image according to the distance a to the object 100. , and it becomes impossible to calculate the distance a to the subject 100 based on the image magnification ratio MR.

Therefore, in the ranging camera of the present invention, the first optical system OS1 and the second optical system OS2 are configured and arranged so that at least one of the following two conditions is satisfied, whereby the distance to the subject 100 is A change in the magnification m1 of the first object image according to a is different from _a change in the magnification _m2 of the second object image according to the distance a to the object 100. FIG.

(First Condition) The focal length f1 of the _first optical system OS1 and the focal length f2 of the _second optical system OS2 are different from _each other ₍ f1≠f2)
(Second condition) The front principal point of the first optical system OS1 in the initial state in which the first lens driving unit AF1 is not performing the focusing operation, and the second lens driving unit AF2 is performing the focusing operation. There is a depth parallax D between the front principal point of the second optical system OS2 in the initial state without

In addition, even if at least one of the first condition and the second condition is satisfied, in order to calculate the distance a to the subject 100 using the general formula (15) or (16), , the first optical system OS1 and the second optical system OS2 must be configured and arranged to satisfy the conditions represented by the following equations (19) and (20). Hereinafter, the condition of formula (19) below will be referred to as the third condition, and the condition of formula (20) below will be referred to as the fourth condition.

When the condition (third condition) of the above formula (19) is not satisfied (that is, when MR=f ₂ /f ₁ ), the denominator of the above general formula (15) or (16) becomes zero. Ultimately, the distance a to the object 100 cannot be calculated based on the image magnification ratio MR. On the other hand, when the condition (fourth condition) of the above formula (20) is not satisfied (that is, when the left side of the above formula (20) is negative), the distance a to the subject 100 includes an imaginary number. Therefore, it is inappropriate.

Therefore, in order to calculate the distance a to the subject 100 based on the image magnification ratio MR, the distance measuring camera of the present invention satisfies at least one of the above first and second conditions, and the third condition , and the fourth condition. Therefore, the size Y1 of the _first object image and the size Y1 of the second object image actually measured from the image signal of the first object image and the image signal of the second object image acquired using the distance measuring camera of the present invention By calculating the image magnification ratio MR from the size Y2 of , the distance a from the front principal point of the _first optical system OS1 to the object 100 can be calculated.

A distance measuring camera according to the present invention, which calculates the distance to a subject using the principle described above, will be described below with reference to preferred embodiments shown in the accompanying drawings.

<First embodiment>
First, referring to FIGS. 4 and 5, the distance measuring camera according to the first embodiment of the invention will be described in detail. FIG. 4 is a block diagram schematically showing a ranging camera according to the first embodiment of the invention. FIG. 5 is a diagram schematically showing a configuration example of the first optical system and the second optical system shown in FIG.

The ranging camera 1 shown in FIG. 4 includes a control unit 2 for controlling the ranging camera 1, and a first optical system OS1 for condensing light from a subject 100 and forming a first subject image. , a first lens driving unit AF1 for executing a focusing operation (or an autofocus operation) of the first optical system OS1; a second optical system OS2, a second lens driving unit AF2 for executing a focus operation (or an autofocus operation) of the second optical system OS2, and a first optical system OS1 formed by 1 and a second object image formed by the second optical system OS2, a magnification m1 of the _first object image and a magnification _m2 of the second object image; image magnification ratio MR and the distance a to the subject 100, and the association information in the association information storage unit 3. a distance calculator 4 for calculating a distance a to the subject 100 based on the first subject image and the second subject image obtained by the imaging section S; A three-dimensional image generation unit 5 for generating a three-dimensional image of the subject 100 based on the subject image and the distance a to the subject 100 calculated by the distance calculation unit 4, and arbitrary information such as a liquid crystal panel. A display unit 6 for displaying, an operation unit 7 for inputting operations by the user, a communication unit 8 for executing communication with an external device, and exchange of data between each component of the ranging camera 1 and a data bus 9 for executing

The configuration of the first optical system OS1 and the configuration of the second optical system OS2 in this embodiment are merely examples for explanation, and the present invention is not limited to this. Each of the first optical system OS1 and the second optical system OS2 satisfies at least one of the above-described first and second conditions, the third condition, and the fourth condition, Any mode may be used as long as the change in the magnification m1 of the first object image with respect to the distance is different from the change in the magnification _m2 of the _second object image with respect to the distance to the object 100 . However, the distance measuring camera 1 of the present embodiment satisfies the first condition out of the first condition and the second condition required for calculating the distance a to the subject 100 based on the image magnification ratio MR. _{The first optical} system _OS1 and the It is characterized by comprising a second optical system OS2. On the other hand, in this embodiment, the first optical system OS1 and the second optical system OS2 are not constructed and arranged to satisfy the second condition (D≠0) described above. Furthermore, in the distance measuring camera 1 of the present embodiment, the first optical system OS1 and the second optical system OS2 are configured to satisfy the third and fourth conditions described above.

Therefore, the above general formulas (15) and (16) for calculating the distance a to the subject 100 using the image magnification ratio MR are simplified by the condition of D=0, and the following formula (21) and (22).

In the present embodiment, since D=0, there is no need to consider the division of conditions in (3) above. If the relationship between the focal length f ₁ of the first optical system OS1 and the focal length f ₂ of the second optical system OS2 satisfies the conditional expression (1) above, f ₂ <f ₁ , the above equation The solution expressed by (21) is suitable for the distance a, and is used as the distance a to the object 100. FIG. On the other hand, if the relationship between the focal length f ₁ of the first optical system OS1 and the focal length f ₂ of the second optical system OS2 satisfies the condition (2) above, f ₂ >f ₁ , the above The solution expressed by equation (22) is suitable as the distance a, and is used as the distance a to the object 100. FIG.

The distance measuring camera 1 of the present embodiment captures an image of the subject 100 with the imaging unit S, thereby calculating an image magnification ratio MR between the magnification m1 of the _first subject image and the magnification _m2 of the second subject image, Furthermore, the distance a to the object 100 is calculated using the above equation (21) or (22).

Each component of the ranging camera 1 will be described in detail below. The control unit 2 exchanges various data and various instructions with each component via the data bus 9 to control the ranging camera 1 . The control unit 2 includes a processor for executing arithmetic processing, and a memory for storing data, programs, modules, etc. necessary for controlling the ranging camera 1. The processor of the control unit 2 controls the distance measuring camera 1 by using data, programs, modules, etc. stored in the memory. Also, the processor of the control unit 2 can provide desired functions by using each component of the ranging camera 1 . For example, the processor of the control unit 2 uses the distance calculation unit 4 to calculate the distance a to the object 100 based on the first object image and the second object image captured by the imaging unit S. process can be executed.

The processor of the control unit 2 is, for example, one or more microprocessors, microcomputers, microcontrollers, digital signal processors (DSPs), central processing units (CPUs), memory control units (MCUs), arithmetic processing units for image processing. An arithmetic unit that performs arithmetic operations such as signal manipulation based on computer readable instructions such as (GPU), state machines, logic circuits, application specific integrated circuits (ASIC), or combinations thereof. In particular, the processor of controller 2 is configured to fetch computer readable instructions (eg, data, programs, modules, etc.) stored in memory of controller 2 and to perform signal manipulation and control.

The memory of the control unit 2 includes volatile storage media (eg, RAM, SRAM, DRAM), non-volatile storage media (eg, ROM, EPROM, EEPROM, flash memory, hard disk, optical disk, CD-ROM, digital versatile disk ( DVD), magnetic cassette, magnetic tape, magnetic disk), or any combination thereof, removable or non-removable.

The first optical system OS1 has a function of condensing light from the subject 100 and forming a first subject image on the imaging surface of the first imaging element S1 of the imaging section S. The second optical system OS2 has a function of condensing light from the subject 100 and forming a second subject image on the imaging surface of the second imaging element S2 of the imaging section S. The first optical system OS1 and the second optical system OS2 are composed of optical elements such as one or more lenses and a diaphragm. Also, as shown in the figure, the optical axis of the first optical system OS1 and the optical axis of the second optical system OS2 are parallel but do not match.

As described above, the first optical system OS1 and the second optical system OS2 are arranged such that the focal length f1 of the _first optical system OS1 and the focal length f2 of the _second optical system OS2 are different from each other. (f ₁ ≠f ₂ ), is constructed. As a result, the change of the magnification m1 of the first object image formed by the _first optical system OS1 in accordance with the distance a to the object 100 is reflected in the second object image formed by the second optical system OS2. is configured to differ from the change according to the distance a to the subject 100 at the magnification _m2 of .

For example, as shown in FIG. 5, the first optical system OS1 is composed of a convex lens (real image optical component), and the second optical system OS2 has the same focal point as the convex lens that constitutes the first optical system OS1. Convex lens (real image optical component) L1 having a distance, and concave lens (virtual image optical component) L2 which is on the same axis as convex lens L1 and which is spaced from convex lens L1 toward object 100 by distance d. ing. In this case, the focal length f2 of the _second optical system OS2 is different from the focal length f1 of the convex lens forming the _first optical system OS1 due to the effect of the concave lens L2. Thus, by making the configurations of the first optical system OS1 and the second optical system OS2 different from each other, the focal length f1 of the _first optical system OS1 and the focal length f1 of the second optical system OS2 and the distances f2 can be different from _each other. The modes of the first optical system OS1 and the second optical system OS2 shown in FIG. 5 are merely examples, and the focal length f1 of the _first optical system OS1 and the focal length f2 of the _second optical system OS2 is different, the present invention is not limited to this.

Taking as an example the embodiment shown in FIG. 5 in which only the second optical system OS2 includes a concave lens L2 and the first optical system OS1 does not include a concave lens, the first optical system OS1 and the second optical system Although the configuration of OS2 has been described, the present invention is not limited to this. It is also within the scope of the invention that the first optical system OS1 and the second optical system OS2 each comprise a concave lens. In this case, by adjusting the number of concave lenses included in each of the first optical system OS1 and the second optical system OS2, the arrangement (for example, the distance from other lenses), and the focal length, the first The focal length f1 of the optical system OS1 and the focal length f2 of the _second optical system OS2 _are different from each other. As a result, the change in the magnification m1 of the first object image with respect to the distance a to the object ₁₀₀ differs from the change in the magnification _m2 of the second object image with respect to the distance a to the object 100. FIG.

Thus, the configuration and arrangement of the first optical system OS1 and the second optical system OS2 in this embodiment satisfy the above-described first condition (f ₁ ≠f ₂ ). What if the change in the magnification m1 of the first object image with respect to the distance a to ₁₀₀ and the change in the magnification _m2 of the second object image with respect to the distance a to the object 100 are different from each other? It may be an aspect.

Returning to FIG. 4, the first lens driving unit AF1 moves at least one of the lenses (for example, the focus lens) constituting the first optical system OS1 in the optical axis direction under the control of the processor of the control unit 2. It has a function of driving (extending) the first optical system OS1 to perform a focus operation (or an autofocus operation) of the first optical system OS1. Similarly, the second lens driving unit AF2 drives at least one of the lenses (for example, the focus lens) constituting the second optical system OS2 in the optical axis direction under the control of the processor of the control unit 2. It has a function of moving (advancing) and executing a focus operation (or an autofocus operation) of the second optical system OS2. If each of the first lens driving unit AF1 and the second lens driving unit AF2 can execute the focusing operation of the first optical system OS1 or the second optical system OS2 according to the control from the processor of the control unit 2, It is not particularly limited, and can be configured by an actuator such as a DC motor, stepping motor, voice coil motor, or the like.

Note that the processor of the control unit 2 drives the first lens driving unit AF1 and the second lens driving unit AF2 using any autofocus technique such as the contrast autofocus technique or the phase difference autofocus technique. The focusing operation of one optical system OS1 and the second optical system OS2 is realized.

The imaging unit S captures a first object image formed by the first optical system OS1 and a second object image formed by the second optical system OS2, and outputs an image signal of the first object image and a second object image. 2 has a function of acquiring the image signal of the subject image. In the present embodiment, the imaging unit S includes a first imaging element S1 for capturing a first subject image and acquiring an image signal of the first subject image, capturing a second subject image, and capturing a second subject image. and a second image sensor S2 for acquiring image signals of two subject images.

The separation distance from the rear principal point of the first optical system OS1 to the imaging surface of the first image sensor S1 is the initial value when the focusing operation of the first optical system OS1 is not performed by the first lens driving unit AF1. In a state (a state in which the first optical system OS1 is indicated by a dotted line in FIG. 4), a first subject image of a subject 100 positioned at infinity is projected onto the imaging surface of the first image sensor S1. set to be formed. In other words, in the initial state in which the focusing operation of the first optical system OS1 is not performed by the first lens driving unit AF1, the first optical system OS1 and the first imaging are adjusted so as to focus on infinity. An element S1 is arranged. Therefore, in the initial state, the separation distance from the rear principal point of the first optical system OS1 to the imaging surface of the first imaging element S1 is equal to the focal length f1 of the _first optical system OS1. Therefore, when the subject 100 is positioned at an arbitrary distance a, at least one of the lenses (for example, the focus lens) constituting the first optical system OS1 is extended under the control of the processor of the control unit 2. As a result, the front principal point and the rear principal point of the first optical system OS1 are shifted by Δb1 toward the object ₁₀₀ , and the object 100 positioned at an arbitrary distance a is brought into focus.

Similarly, the separation distance from the rear principal point of the second optical system OS2 to the imaging surface of the second imaging element S2 is determined by the second lens driving unit AF2 performing the focusing operation of the second optical system OS2. In the initial state (in FIG. 4, the second optical system OS2 is indicated by a dotted line), the second subject image of the subject 100 positioned at infinity is captured by the second image sensor S2. It is set to be formed on the surface. In other words, in the initial state in which the focusing operation of the second optical system OS2 is not performed by the second lens driving unit AF2, the second optical system OS2 and the second imaging are adjusted so as to focus on infinity. An element S2 is arranged. Therefore, in the initial state, the separation distance from the rear principal point of the second optical system OS2 to the imaging surface of the second imaging element S2 is equal to the focal length f2 of the _second optical system OS2. Therefore, when the object 100 is positioned at an arbitrary distance a, at least one of the lenses (for example, the focus lens) constituting the second optical system OS2 is extended under the control of the processor of the control unit 2. As a result, the front principal point and the rear principal point of the _second optical system OS2 are shifted by Δb2 toward the object 100, and the object 100 positioned at an arbitrary distance a is brought into focus.

In the illustrated embodiment, the first image sensor S1, the first lens driving unit AF1, and the first optical system OS1 are provided in the same housing. The lens drive unit AF2 and the second optical system OS2 are provided in another same housing, but the present invention is not limited to this. The first optical system OS1, the second optical system OS2, the first lens driving unit AF1, the second lens driving unit AF2, the first image sensor S1, and the second image sensor S2 are all in the same housing Also within the scope of the present invention are aspects such as those provided in .

The first imaging element S1 and the second imaging element S2 are color imaging elements having color filters such as RGB primary color filters or CMY complementary color filters arranged in an arbitrary pattern such as a Bayer array. Alternatively, it may be a black-and-white imaging device that does not have such a color filter.

The first optical system OS1 forms a first subject image on the imaging surface of the first image sensor S1, and the first image sensor S1 acquires color or black-and-white image signals of the first subject image. be. The acquired image signal of the first subject image is sent to the control section 2 and the distance calculation section 4 via the data bus 9 . Similarly, the second optical system OS2 forms a second subject image on the imaging surface of the second image sensor S2, and the second image sensor S2 generates color or black-and-white image signals of the second subject image. is obtained. The acquired image signal of the second subject image is sent to the control section 2 and the distance calculation section 4 via the data bus 9 . The image signal of the first subject image and the image signal of the second subject image sent to the distance calculator 4 are used to calculate the distance a to the subject 100 . On the other hand, the image signal of the first subject image and the image signal of the second subject image sent to the control section 2 are used for image display by the display section 6 and for communication of image signals by the communication section 8 .

The association information storage unit 3 stores an image magnification ratio MR (m ₂ /m ₁ ) between the magnification m ₁ of the first subject image and the magnification m ₂ of the second subject image, and the front side of the first optical system OS 1 . Any non-volatile recording medium (for example, hard disk, flash memory) for storing association information that associates the distance a from the principal point to the subject 100 .

The association information stored in the association information storage unit 3 is obtained from the image magnification ratio MR (m ₂ /m ₁ ) between the magnification m ₁ of the first subject image and the magnification ₂ of the second subject image. 1 is information for calculating the distance a from the front principal point of the optical system OS1 to the object 100. FIG.

Typically, the association information stored in the association information storage unit 3 is based on the above equations (21) and (22) (or , general formulas (15) and (16)), and the above-mentioned fixed value determined by the configuration and arrangement of the first optical system OS1 and the second optical system OS2 in the formula (the above formula (21 ) and (22), fixed values f ₁ and f ₂ ). Alternatively, the association information stored in the association information storage unit 3 may be a lookup table that uniquely associates the image magnification ratio MR with the distance a to the subject 100 . By referring to such association information stored in the association information storage unit 3, it is possible to calculate the distance a to the subject 100 based on the image magnification ratio MR.

The distance calculator 4 has a function of calculating the distance a to the subject 100 based on the first subject image and the second subject image captured by the imaging section S. FIG. The distance calculator 4 receives the image signal of the first subject image from the first image sensor S1 of the image sensor S, and further receives the image signal of the second subject image from the second image sensor S2 of the image sensor S. receive.

After that, the distance calculation unit 4 performs filter processing such as Canny on the image signal of the first subject image and the image signal of the second subject image, and calculates the first distance in the image signal of the first subject image. and edge portions of the second subject image in the image signal of the second subject image. The distance calculation unit 4 calculates the size (image width or image height) Y1 of the _first subject image based on the extracted edge portion of the first subject image, and further calculates the size of the extracted second subject image. Based on the edge portion, the size (image width or image height) Y2 of the _second object image is calculated.

A distance calculation unit ₄ calculates the size Y1 of the _first subject image and the size Y2 of the second subject image based on the extracted edge portion of the first subject image and the edge portion of the second subject image. Although the method is not particularly limited, for example, in each image signal, the separation distance between the uppermost part and the lowermost part of the edge part of the subject image may be used as the image height of the subject image, or The distance between the leftmost edge portion and the rightmost edge portion of the image may be used as the image width of the subject image.

Thereafter, the distance calculation unit 4 calculates the _first object image size Y1 and the _second object image size Y2 according to the above equation (18) MR ₌ Y2 _/ Y1. An image magnification ratio MR between the image magnification m1 and the _second object image magnification _m2 is calculated. When the image magnification ratio MR is calculated, the distance calculation unit 4 refers to the association information stored in the association information storage unit 3, and calculates the distance a to the subject 100 based on the image magnification ratio MR. (Identify.

The three-dimensional image generation unit 5 generates the distance a to the subject 100 calculated by the distance calculation unit 4 and the two-dimensional image of the subject 100 acquired by the imaging unit S (the image signal of the first subject image or the second subject image image signal) to generate a three-dimensional image of the subject 100 . The "three-dimensional image of the subject 100" referred to here means data in which the calculated distance a of the subject 100 is associated with the pixels of the normal two-dimensional image of the subject 100 in color or black and white.

The display unit 6 is a panel-type display unit such as a liquid crystal display unit, and displays a two-dimensional image of the subject 100 (first subject image image) acquired by the imaging unit S according to a signal from the processor of the control unit 2 . signal or image signal of the second object image), distance a to object 100 generated by distance calculation unit 4, image such as three-dimensional image of object 100 generated by three-dimensional image generation unit 5, distance measurement Information for operating the camera 1 is displayed on the display unit 6 in the form of characters or images.

The operation unit 7 is used by the user of the distance measuring camera 1 to perform operations. The operation unit 7 is not particularly limited as long as the user of the distance measuring camera 1 can operate it. . The operation unit 7 transmits a signal according to the user's operation of the ranging camera 1 to the processor of the control unit 2 .

The communication unit 8 has a function of inputting data to the ranging camera 1 or outputting data from the ranging camera 1 to an external device. The communication unit 8 may be connected to a network such as the Internet. In this case, the distance measuring camera 1 can communicate with an external device such as a web server or data server provided outside by using the communication unit 8 .

Thus, in the distance measuring camera 1 of the present embodiment, the first optical system OS1 and the second optical system OS2 have a focal length f1 of the _first optical system OS1 and a focal length f1 of the second optical system OS2. f ₂ are different from _each other (f ₁ ≠f ₂ ). are different from _each other. Therefore, the distance measuring camera ₁ of the present invention does not use translational parallax between a plurality of images, and does not irradiate the subject in a fixed pattern. Based on the image magnification ratio MR (m ₂ /m ₁ ) to the image magnification m ₂ , the distance a to the object 100 can be uniquely calculated (identified).

Further, in the present embodiment, the first optical system OS1 and the second optical system OS2 are arranged such that the focal length f1 of the _first optical system OS1 and the focal length f2 of the _second optical system OS2 are different. , the angle of view and the magnification of the image signal of the first subject image acquired by the first image pickup element S1 of the image pickup section S are obtained by the second image pickup element S2 of the image pickup section S. different from the angle of view and the magnification of the image signal of the second object image. Therefore, with the ranging camera 1 of the present embodiment, two image signals (image signal of the first subject image and image signal of the second subject image) with different angles of view and magnifications can be obtained simultaneously. . A plurality of image signals with different angles of view and magnifications can be used for various purposes.

For example, since the rangefinder camera 1 of this embodiment can acquire a plurality of image signals with different angles of view and magnifications, the rangefinder camera 1 of this embodiment can be suitably used in an iris authentication system. . When the ranging camera 1 of the present embodiment is used in an iris authentication system, a face image (or whole body image) of an authentication subject with a wide angle of view and low magnification and a binocular image of the authentication subject with a narrow angle of view and high magnification can be obtained simultaneously. Therefore, by using the distance measuring camera 1 of the present embodiment, iris authentication of both eyes can be performed without using a camera having a zoom function, and the iris authentication system can be made smaller and less expensive. can.

Also, the distance measuring camera 1 of the present embodiment can be suitably used in a handler robot used for assembling and inspecting precision equipment. When driving the handler robot, it is necessary to calculate the distance to the part to be assembled, and to use a wide-angle, low-magnification image to identify the rough position of the part, A narrow angle of view and high magnification images are required for precise control of the hand of the handler robot. The distance measuring camera 1 of the present embodiment can calculate the distance to a part (object), and can simultaneously acquire an image with a wide angle of view and a low magnification and an image with a narrow angle of view and a high magnification. It is particularly useful in handler robots because it can The distance measuring camera 1 of the present embodiment can provide three functions of measuring the distance to a component, acquiring a wide angle of view and low magnification image, and acquiring a narrow angle of view and high magnification image. By using the distance measuring camera 1 of this embodiment in the handler robot, the number of cameras used in the handler robot can be reduced. Therefore, the size and cost of the handler robot can be reduced.

Also, the distance measuring camera 1 of the present embodiment can be suitably used for vehicle occupant detection. By acquiring wide-angle and low-magnification images with the distance measuring camera 1 of the present embodiment, it is possible to detect a wide range of occupants in the vehicle without using an additional camera. Therefore, the vehicle occupant detection system can be reduced in size and cost.

<Second embodiment>
Next, referring to FIG. 6, the distance measuring camera 1 according to the second embodiment of the present invention will be described in detail. FIG. 6 is a block diagram schematically showing a ranging camera according to a second embodiment of the invention.

In the following, the distance measuring camera 1 of the second embodiment will be described with a focus on the differences from the distance measuring camera 1 of the first embodiment, and the description of the same items will be omitted. In the distance measuring camera 1 of the second embodiment, the first band-pass filter 10a is placed on the optical path of the light condensed on the imaging surface of the first imaging element S1 of the imaging unit S by the first optical system OS1. Further, the second bandpass filter 10b is arranged on the optical path of the light condensed on the imaging surface of the second imaging element S2 of the imaging unit S by the second optical system OS2. Except for this, it is the same as the distance measuring camera 1 of the first embodiment.

In the illustrated embodiment, the first band-pass filter 10a is arranged on the front side (object 100 side) of the first optical system OS1, and the second band-pass filter 10b is arranged on the front side of the second optical system OS2. (Subject 100 side), but the present invention is not limited to this. For example, the first bandpass filter 10a is arranged on the rear side of the first optical system OS1 (on the side of the first imaging element S1), and the second bandpass filter 10b is arranged on the rear side of the second optical system OS2 (on the side of the first imaging element S1). A mode in which the second image sensor S2 side) is arranged is also within the scope of the present invention.

The first bandpass filter 10a passes only light in a specific wavelength band among the light from the subject 100 condensed on the imaging surface of the first imaging element S1 by the first optical system OS1. The second bandpass filter 10b passes only light in a specific wavelength band among the light from the object 100 condensed on the imaging surface of the second imaging element S2 by the second optical system OS2. The wavelength band of light passed by the first bandpass filter 10a is different from the wavelength band of light passed by the second bandpass filter 10b. Therefore, the first imaging element S1 and the second imaging element S2 can receive light in different wavelength bands.

Note that each of the first imaging element S1 and the second imaging element S2 has a color filter such as an RGB primary color filter or a CMY complementary color filter arranged in an arbitrary pattern such as a Bayer array for color imaging. A device may be used, or a black-and-white image sensor having no color filter may be used, but a black-and-white image sensor is preferable. By using black-and-white imaging elements as the first imaging element S1 and the second imaging element S2, the amount of light in a specific wavelength band that has passed through the first bandpass filter 10a or the second bandpass filter 10b can be converted into a color image. Further reduction due to the color filter of the imaging device can be prevented.

As described above, in the present embodiment, the first image sensor S1 and the second image sensor S2 can respectively receive light in different wavelength bands, so that two images formed by light in different wavelength bands can be obtained. Signals (the image signal of the first subject image and the image signal of the second subject image) can be obtained simultaneously. Therefore, the distance measuring camera 1 can be used in applications where it is useful to use a plurality of image signals formed by light of different wavelength bands, such as an iris authentication system and a dark field occupant state detection system for an on-vehicle camera.

Moreover, in the distance measuring camera 1 of the present embodiment, it is not necessary to use a plurality of light sources emitting light of different wavelength bands in order to acquire two image signals formed by light of different wavelength bands. Therefore, even when the distance measuring camera 1 is used in applications where it is useful to use a plurality of image signals formed by light of different wavelength bands as described above, the distance measuring camera 1 can be made smaller and less expensive. be.

<Third Embodiment>
Next, referring to FIG. 7, the distance measuring camera 1 according to the third embodiment of the present invention will be described in detail. FIG. 7 is a block diagram schematically showing a ranging camera according to a third embodiment of the invention.

In the following, the distance measuring camera 1 of the third embodiment will be described with a focus on the differences from the distance measuring camera 1 of the second embodiment, and the description of the same items will be omitted. In the distance measuring camera 1 of the third embodiment, the imaging section S is composed only of the first imaging element S1, the first optical system OS1, the second optical system OS2, and the first lens driving section AF1. , the second lens drive unit AF2, the first band-pass filter 10a, the second band-pass filter 10b, and the first image sensor S1 are provided in the same housing, and the mirror 11 is provided in the housing. , and a prism 12 are provided, and the first image sensor S1 is limited to a color image sensor.

As shown in FIG. 7, in this embodiment, a first optical system OS1, a second optical system OS2, a first lens driving unit AF1, a second lens driving unit AF2, a first bandpass filter 10a, The second bandpass filter 10b and the first imaging element S1 are provided in the same housing. A mirror 11 and a prism 12 are arranged on the optical path of the light condensed by the second optical system OS2. Light passing through the second bandpass filter 10b and condensed by the second optical system OS2 passes through the mirror 11 and the prism 12 and forms an image on the imaging surface of the first imaging element S1. As a result, a second subject image is formed on the imaging surface of the first imaging element S1.

Therefore, in the present embodiment, both the first subject image formed by the first optical system OS1 and the second subject image formed by the second optical system OS2 are captured by the first image sensor S1. formed on the imaging surface.

In this embodiment, the first image sensor S1 is a color image sensor having color filters such as RGB primary color filters and CMY complementary color filters arranged in an arbitrary pattern such as the Bayer array. . The wavelength band of the light passed by the first bandpass filter 10a corresponds to any one of the plurality of color filters of the first imaging element S1, and the light passed by the second bandpass filter 10b corresponds to a different one of the plurality of color filters of the first imaging element S1.

As a result, any one of the image signals (for example, red image signal, green image signal, and blue image signal) corresponding to each color filter acquired by the first image sensor S1 is the image of the first subject image. A different one corresponds to the image signal of the second object image. Therefore, the first image sensor S1 can separate and simultaneously acquire the image signal of the first subject image and the image signal of the second subject image.

For example, when the wavelength band of light passed by the first band-pass filter 10a corresponds to the transmission wavelength band of the red color filter of the plurality of color filters of the first imaging device S1, the first imaging device The red image signal acquired by S1 becomes the image signal of the first subject image. On the other hand, when the wavelength band of light passed by the second band-pass filter 10b corresponds to the transmission wavelength band of the green color filters of the plurality of color filters of the first imaging device S1, the first imaging device The green image signal acquired by S1 becomes the image signal of the second subject image.

With such an aspect, the imaging unit S is a single unit that captures both the first object image formed by the first optical system OS1 and the second object image formed by the second optical system OS2. It can be configured with a color image pickup device (first image pickup device S1). Therefore, it is possible to reduce the size and cost of the ranging camera 1 .

<Fourth Embodiment>
Next, referring to FIG. 8, the distance measuring camera 1 according to the fourth embodiment of the present invention will be described in detail. FIG. 8 is a block diagram schematically showing a ranging camera according to a fourth embodiment of the invention.

In the following, the distance measuring camera 1 of the fourth embodiment will be described with a focus on the differences from the distance measuring camera 1 of the third embodiment, and the description of the same items will be omitted. In the distance measuring camera 1 of the fourth embodiment, the first bandpass filter 10a and the second bandpass filter 10b are omitted, and the first shutter 13a and the second shutter 13b are provided in the housing. and that the first image sensor S1 is not limited to a color image sensor.

As shown in FIG. 8, in the present embodiment, a first shutter 13a for blocking light from the subject 100 entering the first optical system OS1 and a second shutter 13a for blocking light from the subject 100 to the second optical system OS2. A second shutter 13b for blocking the incidence is provided in the housing. The first shutter 13 a and the second shutter 13 b are controlled by the processor of the controller 2 and open and close according to signals from the processor of the controller 2 . The first shutter 13a and the second shutter 13b are controlled so that only one of them is opened, and they are not opened at the same time.

When the first shutter 13a is opened, light from the subject 100 enters the first optical system OS1, forming a first subject image on the imaging surface of the first image sensor S1. At this time, the first image pickup device S1 acquires the image signal of the first subject image and sends the image signal of the first subject image to the control section 2 and the distance calculation section 4 .

On the other hand, when the second shutter 13b is opened, the light from the subject 100 enters the second optical system OS2, passes through the mirror 11 and the prism 12, and is projected onto the imaging surface of the first image sensor S1 as the second light. is formed. At this time, the first image sensor S1 acquires the image signal of the second subject image and sends the image signal of the second subject image to the control section 2 and the distance calculation section 4. FIG.

As described above, in the present embodiment, one of the first shutter 13a and the second shutter 13b is opened under the control of the processor of the controller 2 . Through such control, the ranging camera 1 can separate and acquire the image signal of the first subject image and the image signal of the second subject image.

Further, in this embodiment, the imaging unit S is a single unit for capturing both the first object image formed by the first optical system OS1 and the second object image formed by the second optical system OS2. image sensor (first image sensor S1). Therefore, it is possible to reduce the size and cost of the ranging camera 1 .

Moreover, in this embodiment, unlike the above-described third embodiment, the first image sensor S1 may be a black-and-white image sensor. By using a black-and-white imaging device as the first imaging device S1, the cost of the distance measuring camera 1 can be further reduced.

<Fifth Embodiment>
Next, referring to FIG. 9, the distance measuring camera 1 according to the fifth embodiment of the present invention will be described in detail. FIG. 9 is a block diagram schematically showing a distance measuring camera according to a fifth embodiment of the invention.

In the following, the distance measuring camera 1 of the fifth embodiment will be described with a focus on the differences from the distance measuring camera 1 of the first embodiment, and the description of the same items will be omitted. The rangefinder camera 1 of this embodiment is the same as the rangefinder camera 1 of the first embodiment, except that the configuration and arrangement of the first optical system OS1 and the second optical system OS2 are changed.

As shown in FIG. 9, the distance measuring camera 1 of the present embodiment has the first and second conditions required to calculate the distance a to the subject 100 based on the image magnification ratio MR. Among them, the front principal point of the first optical system OS1 in the initial state in which the first lens driving unit AF1 does not perform the focusing operation, and the initial state in which the second lens driving unit AF2 does not perform the focusing operation. The first optical system OS1 and the second optical system OS2 are arranged so as to satisfy the second condition that there is a depth parallax D with the front principal point of the second optical system OS2 (D≠0). is configured and arranged. On the other hand, in this embodiment, the first optical system OS1 and the second optical system OS2 are not configured to satisfy the first condition (f ₁ ≠f ₂ ) described above. Furthermore, in the distance measuring camera 1 of the present embodiment, the first optical system OS1 and the second optical system OS2 are configured to satisfy the third and fourth conditions described above.

Therefore, the above general formulas (15) and (16) for calculating the distance a from the front principal point of the first optical system OS1 to the subject 100 using the image magnification ratio MR are f ₁ =f ₂ = It is simplified by the condition of f and can be represented by the following equations (23) and (24), respectively.

In this embodiment, from the condition f ₁ =f ₂ =f, the relationship between the focal length f ₁ of the first optical system OS1 and the focal length f ₂ of the second optical system OS2 is the above ( Since the conditional expression 1) f ₂ ≤ f ₁ is necessarily satisfied, the solution represented by the above equation (23) is suitable as the distance a. Therefore, the solution represented by the above equation (23) is used as the distance a to the subject 100. FIG.

As described above, in the distance measuring camera 1 of the present embodiment, the front principal point of the first optical system OS1 and the second lens driving section in the initial state in which the first lens driving section AF1 is not performing the focusing operation. It is constructed and arranged so that there is a depth parallax D between the front principal point of the second optical system OS2 and the front principal point of the second optical system OS2 in the initial state where the AF2 is not performing a focusing operation (D≠0). The change in the magnification m1 of the first object image with respect to the distance a to ₁₀₀ and the change in the magnification _m2 of the second object image with respect to the distance a to the object 100 are different from each other. Therefore, the distance measuring camera 1 of the present embodiment calculates the subject 100 based on the image magnification ratio MR (m ₂ /m ₁ ) between the magnification m ₁ of the first subject image and the magnification m ₂ of the second subject image. It is possible to uniquely calculate the distance a to .

This embodiment can also exhibit the same effect as the above-described first embodiment. Note that the configuration of the first optical system OS1 and the configuration and arrangement of the second optical system OS2 in this embodiment satisfy the second condition described above, thereby providing a Any mode may be used as long as the change in the magnification m1 of the _first subject image and the change in the magnification _m2 of the second subject image with respect to the distance a to the subject 100 are different from each other.

<Sixth embodiment>
Next, with reference to FIG. 10, the distance measuring camera 1 according to the sixth embodiment of the present invention will be described in detail. FIG. 10 is a block diagram schematically showing a ranging camera according to the sixth embodiment of the invention.

In the following, the distance measuring camera 1 of the sixth embodiment will be described with a focus on the differences from the distance measuring camera 1 of the fifth embodiment, and the description of the same items will be omitted. The difference between the rangefinder camera 1 of the present embodiment and the rangefinder camera 1 of the fifth embodiment is the difference between the rangefinder camera 1 of the second embodiment and the rangefinder camera 1 of the first embodiment. It is the same. That is, in the distance measuring camera 1 of the sixth embodiment, the first band-pass filter is placed on the optical path of the light condensed on the imaging surface of the first imaging element S1 of the imaging unit S by the first optical system OS1. 10a is arranged, and a second bandpass filter 10b is arranged on the optical path of light condensed on the imaging surface of the second imaging device S2 of the imaging unit S by the second optical system OS2. It is the same as the distance measuring camera 1 of the fifth embodiment except for one point.

As shown in FIG. 10, similarly to the second embodiment, the first band-pass filter 10a is configured to filter light from an object 100 condensed onto the imaging surface of the first image sensor S1 by the first optical system OS1. Only light in a specific wavelength band is allowed to pass through. The second bandpass filter 10b passes only light in a specific wavelength band among the light from the object 100 condensed on the imaging surface of the second imaging element S2 by the second optical system OS2. Also, the wavelength band of light passed by the first band-pass filter 10a is different from the wavelength band of light passed by the second band-pass filter 10b. Therefore, the first imaging element S1 and the second imaging element S2 can receive light in different wavelength bands.

As described above, in the present embodiment, as in the second embodiment, the first image sensor S1 and the second image sensor S2 can receive light in different wavelength bands, respectively. Two image signals (the image signal of the first subject image and the image signal of the second subject image) formed by light can be obtained simultaneously. Therefore, the distance measuring camera 1 can be used in applications where it is useful to use a plurality of image signals formed by light of different wavelength bands, such as an iris authentication system and a dark field occupant state detection system for an on-vehicle camera.

Also, as in the second embodiment, in this embodiment, there is no need to use a plurality of light sources emitting light in different wavelength bands in order to acquire two image signals formed by light in different wavelength bands. Therefore, even when the distance measuring camera 1 is used in applications where it is useful to use a plurality of image signals formed by light of different wavelength bands as described above, the distance measuring camera 1 can be made smaller and less expensive. be.

<Seventh embodiment>
Next, with reference to FIG. 11, the distance measuring camera 1 according to the seventh embodiment of the present invention will be described in detail. FIG. 11 is a block diagram schematically showing a ranging camera according to a seventh embodiment of the invention.

In the following, the distance measuring camera 1 of the seventh embodiment will be described with a focus on the differences from the distance measuring camera 1 of the sixth embodiment, and the description of the same items will be omitted. The difference between the rangefinder camera 1 of the present embodiment and the rangefinder camera 1 of the sixth embodiment is the difference between the rangefinder camera 1 of the third embodiment and the rangefinder camera 1 of the second embodiment. It is the same. That is, in the distance measuring camera 1 of the seventh embodiment, the imaging section S is composed only of the first imaging element S1, the first optical system OS1, the second optical system OS2, and the first lens drive The part AF1, the second lens driving part AF2, the first bandpass filter 10a, the second bandpass filter 10b, and the first image sensor S1 are provided in the same housing. It is the same as the distance measuring camera 1 of the sixth embodiment except that a mirror 11 and a prism 12 are provided and the first image sensor S1 is limited to a color image sensor.

As shown in FIG. 11, similarly to the third embodiment, a first optical system OS1, a second optical system OS2, a first lens driving unit AF1, a second lens driving unit AF2, a first band pass A filter 10a, a second bandpass filter 10b, and a first imaging element S1 are provided in the same housing. A mirror 11 and a prism 12 are arranged on the optical path of the light condensed by the second optical system OS2. Light passing through the second bandpass filter 10b and condensed by the second optical system OS2 passes through the mirror 11 and the prism 12 and forms an image on the imaging surface of the first imaging element S1. As a result, a second subject image is formed on the imaging surface of the first imaging element S1.

Further, as in the third embodiment, the first image pickup device S1 has color filters such as RGB primary color filters and CMY complementary color filters arranged in an arbitrary pattern such as the Bayer array for color imaging. element. The wavelength band of the light passed by the first bandpass filter 10a corresponds to any one of the plurality of color filters of the first imaging element S1, and the light passed by the second bandpass filter 10b corresponds to a different one of the plurality of color filters of the first imaging element S1.

As a result, any one of the image signals (for example, red image signal, green image signal, and blue image signal) corresponding to each color filter acquired by the first image sensor S1 is the image of the first subject image. A different one corresponds to the image signal of the second object image. Therefore, the first image sensor S1 can separate and simultaneously acquire the image signal of the first subject image and the image signal of the second subject image.

<Eighth embodiment>
Next, with reference to FIG. 12, the distance measuring camera 1 according to the eighth embodiment of the present invention will be described in detail. FIG. 12 is a block diagram schematically showing a distance measuring camera according to an eighth embodiment of the invention.

In the following, the distance measuring camera 1 of the eighth embodiment will be described with a focus on the differences from the distance measuring camera 1 of the seventh embodiment, and the description of the same items will be omitted. The difference between the distance measuring camera 1 of the present embodiment and the distance measuring camera 1 of the seventh embodiment is the difference between the distance measuring camera 1 of the fourth embodiment and the distance measuring camera 1 of the third embodiment. It is the same. That is, in the ranging camera 1 of the eighth embodiment, the first bandpass filter 10a and the second bandpass filter 10b are omitted, and the first shutter 13a and the second shutter 13b are provided inside the housing. It is the same as the distance measuring camera 1 of the seventh embodiment except that it is provided and that the first image sensor S1 is not limited to a color image sensor.

As shown in FIG. 12, similarly to the fourth embodiment, in the distance measuring camera 1 of the present embodiment, the front side (subject 100 side) of the first optical system OS1 is provided with the subject toward the first optical system OS1. A first shutter 13a for blocking the incidence of light from the object 100 is arranged, and a second shutter 13a for blocking the incidence of light from the object 100 to the second optical system OS2 is arranged on the front side of the second optical system OS2. A shutter 13b is arranged.

Since the first shutter 13a and the second shutter 13b operate in the same manner as in the above-described fourth embodiment, the distance measuring camera 1 uses only a single image pickup device (first image pickup device S1). , the image signal of the first object image and the image signal of the second object image can be obtained separately.

As described above, in the present embodiment, similarly to the fourth embodiment, the imaging unit S is composed of the first object image formed by the first optical system OS1 and the second object image formed by the second optical system OS2. can be configured with a single image sensor (first image sensor S1) that captures both of the subject images. Therefore, it is possible to reduce the size and cost of the ranging camera 1 .

As described in detail with reference to each embodiment, the distance measuring camera 1 of the present invention does not use translational parallax between a plurality of images and does not irradiate a subject with a fixed pattern. The distance a to the subject 100 can be uniquely calculated based on the image magnification ratio MR (m ₂ /m ₁ ) between the magnification m ₁ of the first subject image and the magnification m ₂ of the second subject image.

Therefore, in the ranging camera 1 of the present invention, unlike a conventional stereo camera type ranging camera using translational parallax between a plurality of images, it is not necessary to secure a large translational parallax. and the second optical system OS2 are arranged close to each other, the distance a to the subject 100 can be calculated accurately. This makes it possible to reduce the size of the distance measuring camera 1 as compared with a conventional stereo camera type distance measuring camera. Moreover, since it is not necessary to design the ranging camera 1 in consideration of translational parallax, the degree of freedom in designing the ranging camera 1 can be increased.

Further, unlike a pattern irradiation type rangefinder camera, the rangefinder camera 1 of the present invention does not need to use a special light source such as a projector that irradiates a subject with light of a predetermined pattern. Therefore, the system configuration of the ranging camera 1 can be simplified. This makes it possible to reduce the size, power consumption, and cost of the ranging camera 1 as compared with a conventional ranging camera of the pattern irradiation method.

Although two optical systems, the first optical system OS1 and the second optical system OS2, are used in each of the above-described embodiments, the number of optical systems used is not limited to this. For example, in addition to the first optical system OS1 and the second optical system OS2, an aspect further comprising an additional optical system is also within the scope of the present invention. In this case, the additional optical system is such that the change in the magnification of the object image formed by the additional optical system with respect to the distance a to the object 100 is the magnification m of the _first object image with respect to the distance a to the object It is constructed and arranged to differ from the change and the change with respect to the distance a to the object of the magnification _m2 of the second object image.

Further, in each of the above-described embodiments, any one of the above-described first condition and second condition required for calculating the distance a to the subject 100 based on the image magnification ratio MR; The first optical system OS1 and the second optical system OS2 are configured and arranged so as to satisfy conditions 3 and 4, and all of the above-described first to fourth conditions are satisfied. , the configuration and arrangement of the first optical system OS1 and the second optical system OS2 (for example, the configuration and arrangement of the first optical system OS1 and the second optical system OS2 as shown in FIG. ) are also within the scope of the present invention.

<Range measurement method>
Next, with reference to FIG. 13, the distance measuring method executed by the distance measuring camera 1 of the present invention will be described. FIG. 13 is a flow chart for explaining the ranging method executed by the ranging camera of the present invention. The distance measuring method described in detail below can be executed using the distance measuring camera 1 according to the above-described first to eighth embodiments of the present invention and any device having the same function as the distance measuring camera 1. However, for the sake of explanation, it is assumed that the distance measuring camera 1 according to the first embodiment is used.

The distance measurement method S100 shown in FIG. 13 is started when the user of the distance measurement camera 1 uses the operation unit 7 to perform an operation for measuring the distance a to the object 100. FIG. In step S110, the first lens driving unit AF1 is driven under the control of the processor of the control unit 2, and the focusing operation of the first optical system OS1 for focusing on the object 100 is executed. . After that, the first image sensor S1 of the imaging unit S captures the first subject image formed by the first optical system OS1, and the image signal of the first subject image is acquired. An image signal of the first subject image is sent to the control section 2 and the distance calculation section 4 via the data bus 9 . In step S120, the distance calculator 4 calculates the size (image height or image width) Y1 of the _first subject image from the received image signal of the first subject image.

On the other hand, in step S130, the second lens driving unit AF2 is driven according to the control from the processor of the control unit 2, and the focusing operation of the second optical system OS2 for focusing on the subject 100 is executed. be done. After that, the second image sensor S2 of the imaging unit S captures the second subject image formed by the second optical system OS2, and the image signal of the second subject image is obtained. An image signal of the second subject image is sent to the control section 2 and the distance calculation section 4 via the data bus 9 . In step S140, the distance calculator 4 calculates the size (image height or image width) Y2 of the _second subject image from the received image signal of the second subject image.

The acquisition of the image signal of the first subject image and the calculation of the size Y1 of the _first subject image in steps S110 and S120 are the same as the acquisition of the image signal of the second subject image in steps S130 and S140. It may be executed simultaneously with the calculation of the size Y2 of the _two subject images, or may be executed separately.

When _both the size Y1 of the _first subject image and the size Y2 of the second subject image are calculated, the process proceeds to step S150. In step S150, the distance calculation unit 4 calculates the _first distance from the size Y1 of the _first subject image and the size Y2 of the _second subject image based on the above equation (18) MR ₌ Y2/Y1. An image magnification ratio MR between the magnification m1 of the subject image and the magnification _m2 of the _second subject image is calculated.

Next, in step S160, the distance calculation unit 4 refers to the association information stored in the association information storage unit 3, and calculates the distance a to the subject 100 based on the calculated image magnification ratio MR ( Identify. After the distance a to the subject 100 is calculated in step S160, the process proceeds to step S170.

In step S170, the three-dimensional image generation unit 5 calculates the distance a to the subject 100 calculated by the distance calculation unit 4 and the two-dimensional image of the subject 100 acquired by the imaging unit S (the image signal of the first subject image or the first 2), a three-dimensional image of the subject 100 is generated. After that, the two-dimensional image of the subject 100, the distance a to the subject 100, and/or the three-dimensional image of the subject 100 acquired in the steps up to this point are displayed on the display unit 6, or sent to an external device by the communication unit 8. transmitted and the ranging method S100 ends.

Although the distance measuring camera of the present invention has been described above based on the illustrated embodiments, the present invention is not limited to this. Each configuration of the present invention can be replaced with any one capable of exhibiting a similar function, or any configuration can be added to each configuration of the present invention.

Those skilled in the art and technology to which the present invention pertains will be able to implement modifications in the described configuration of the inventive ranging camera without significantly departing from the principles, concepts and scope of the present invention. , ranging cameras with modified configurations are also within the scope of the present invention.

For example, the number and type of components of the ranging camera 1 shown in FIGS. 4 and 6 to 12 are merely examples for explanation, and the present invention is not necessarily limited thereto. Embodiments in which any components are added or combined, or any components are omitted, are within the scope of the present invention without departing from the principles and intent of the present invention. Further, each component of the distance measuring camera 1 may be implemented in hardware, software, or a combination thereof.

Also, the number and types of steps of the ranging method S100 shown in FIG. 13 are merely examples for explanation, and the present invention is not necessarily limited to this. It is also within the scope of the present invention that any step is added or combined for any purpose, or any step is deleted without departing from the principle and intent of the present invention.

<Usage example>
Examples of use of the ranging camera 1 of the present invention are not particularly limited. In such a form of use, it is preferable to incorporate the distance measuring camera 1 of the present invention into a mobile device such as a smart phone or a mobile phone.

Also, the distance measuring camera 1 of the present invention can be used in a handler robot used for assembling and inspecting precision equipment. According to the ranging camera 1, when assembling a precision device, the distance from the handler robot main body or the handler robot arm to the precision device or parts of the precision device can be measured. The part can be gripped to the

Further, according to the distance measuring camera 1 of the present invention, it is possible to measure the distance to the subject, so that it is possible to obtain the three-dimensional information of the subject. Such three-dimensional information of an object can be used for producing a three-dimensional structure by a 3D printer.

Further, by using the distance measuring camera 1 of the present invention in an automobile, the distance from the automobile to any object such as a pedestrian or an obstacle can be measured. Information on the calculated distance to an arbitrary object can be used for automatic braking systems and automatic driving of automobiles.

DESCRIPTION OF SYMBOLS 1... Ranging camera 2... Control part 3... Associated information storage part 4... Distance calculation part 5... Three-dimensional image generation part 6... Display part 7... Operation part 8... Communication part 9... Data bus 10a... First band Pass filter 10b... Second bandpass filter 11... Mirror 12... Prism 13a... First shutter 13b... _Second shutter a... Distance _A ... Distance d... Separation distance D... Depth parallax f, f1, f2... Focal length m ₁ , m ₂ Magnification OS1 First optical system OS2 Second optical system L1 Convex lens L2 Concave lens S Imaging unit S1 First image sensor S2 Second image sensor S100 Measurement Distance method S110, S120, S130, S140, S150, S160, S170 Steps Δb ₁ , Δb ₂ Shift amount 100 Subject AF1 First lens driving unit AF2 Second lens driving unit IS1, IS2 Imaging system

Claims (9)

a first optical system for condensing light from a subject and forming a first subject image;
a second optical system for condensing the light from the subject and forming a second subject image;
an imaging unit for capturing the first subject image formed by the first optical system and the second subject image formed by the second optical system;
a distance calculation unit for calculating a distance to the subject based on the first subject image and the second subject image captured by the imaging unit;
a first lens driving unit for performing a focusing operation of the first optical system;
a second lens driving unit for executing a focusing operation of the second optical system;
The distance calculation unit calculates the distance to the subject based on an image magnification ratio between the magnification of the first subject image and the magnification of the second subject image,
the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image varies according to the distance to the subject;
The first optical system and the second optical system are configured such that the focal length of the first optical system and the focal length of the second optical system are different from each other. A change in the magnification of the first subject image according to the distance to the subject is different from a change in the magnification of the second subject image according to the distance to the subject. A rangefinder camera characterized by: A one-to-one relationship is established between the value of the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image and the distance to the subject. 1. The distance measuring camera according to 1. The distance calculation unit is configured to at least
the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image;
the focal length of the first optical system;
3. The distance measuring camera according to claim 1, wherein the distance to the object is calculated using the focal length of the second optical system. The first optical system, the second optical system, and the imaging section are configured to be at infinity in an initial state in which the first lens driving section and the second lens driving section are not performing the focusing operation. It is arranged so that the focus is on the
The distance calculator further uses the depth parallax in the optical axis direction between the front principal point of the first optical system in the initial state and the front principal point of the second optical system in the initial state. 4. The distance measuring camera according to claim 3, wherein the distance to the subject is calculated by a first optical system for condensing light from a subject and forming a first subject image;
a second optical system for condensing the light from the subject and forming a second subject image;
an imaging unit for capturing the first subject image formed by the first optical system and the second subject image formed by the second optical system;
a distance calculation unit for calculating a distance to the subject based on the first subject image and the second subject image captured by the imaging unit;
an image magnification ratio between the magnification of the first subject image and the magnification of the second subject image varies according to the distance to the subject;
The distance calculation unit is configured to at least
the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image;
a focal length of the first optical system;
and a focal length of the second optical system to calculate the distance to the object. 6. The distance measuring camera according to claim 5, wherein said focal length of said first optical system and said focal length of said second optical system are different from each other. further comprising a first lens driving unit for executing the focusing operation of the first optical system, and a second lens driving unit for executing the focusing operation of the second optical system,
The first optical system, the second optical system, and the imaging section are configured to be at infinity in an initial state in which the first lens driving section and the second lens driving section are not performing the focusing operation. It is arranged so that the focus is on the
The distance calculator further uses the depth parallax in the optical axis direction between the front principal point of the first optical system in the initial state and the front principal point of the second optical system in the initial state. 7. The distance measuring camera according to claim 5, wherein the distance to the subject is calculated by 8. The distance measuring camera according to claim 7, wherein the distance calculator calculates the distance to the subject using the following formula (1) or (2).

Here, a is the distance to the subject, MR is the image magnification ratio, f1 is the focal length of the _first optical system, and f2 is the _second is the focal length of the optical system, and D is the light between the front principal point of the first optical system in the initial state and the front principal point of the second optical system in the initial state It is the depth parallax in the axial direction. A one-to-one relationship is established between the value of the image magnification ratio between the magnification of the first subject image and the magnification of the second subject image and the distance to the subject. 9. A ranging camera according to any one of 5 to 8.

Images