JPH0799332B2 - Convergence mechanism - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a convergence adjusting mechanism used to image the same object at a desired position by two focusing optical systems.
Such a convergence adjustment mechanism is effectively used, for example, to optically measure a distance to an object by stereoscopic vision.

[Prior Art] There is a so-called stereo method as a method of optically measuring a distance to an object. In this method, two objective lenses having the same focal length are kept parallel to each other with their optical axes being parallel to each other with a predetermined distance therebetween, and an illuminance distribution measuring means is arranged behind each objective lens to measure these two. The distance to the object can be calculated from the positional relationship of the same illuminance distribution pattern measured by the means.

FIGS. 4A and 4B are diagrams for explaining the principle of the stereo method. In the figure, 101 and 102 are light-focusing objective lenses having the same focal length, and 101A and 102A are their optical axes. The lenses 101 and 102 are arranged such that the optical axes 101A and 102A are parallel to each other and the straight line (base line) connecting the lens centers is orthogonal to the optical axes 101A and 102A. Lens 1
A measuring means 103 is arranged behind the lens 01 at a position separated by the focal length F of the lens, and a measuring means 104 is arranged behind the lens 102 at a position separated by the distance F. These measuring means are arranged on one straight line in a direction parallel to the base line direction of the lenses 101 and 102.

In FIG. 4A, the object 105 exists at infinity on the optical axis 101A. In this case, the image 106 of the object 105 on the measuring means 103 by the lens 101 is on the optical axis 101A, and similarly the object 105 on the measuring means 104 by the lens 102.
Image 107 of is present on the optical axis 102A.

In FIG. 4B, the object 105 exists at a position separated by a finite distance X on the optical axis 101A. In this case, the image 106 of the object 105 on the measuring means 103 by the lens 101
Exists on the optical axis 101A, but the measuring means 1 by the lens 102
An image 107 of the object 105 on 04 exists at a position separated from the optical axis 102A by a distance D.

Therefore, by detecting the deviation amount D of the image 107 from the optical axis 102A by the measuring means, the lenses 101 and 102 and the measuring means 10
The distance X to be measured can be obtained from the distance F to the 3,104 and the base line length L by the calculation processing according to the following equation.

X = FL / D By the way, since an object generally has a certain extent, an image is formed over a range on the measuring means. Therefore, it is difficult to identify the images of the same object point on the same object. Therefore, in the above stereo method, in order to obtain the positions of the images 106, 107 by the measuring means 103, 104, the illuminance distribution in one measuring means 103 and the illuminance distribution in the other measuring means 104 are correlated. .

5 (a), (b) and (c) are diagrams for explaining the principle of such a correlation method.

As the measuring means 103 and 104, for example, a CCD array which is a self-scanning sensor is used.

In FIG. 5A, the CCD array 103, which is a measuring means corresponding to the lens 101, has n light receiving elements, and the lens 10
The CCD array, which is the measuring means corresponding to 2, has m light receiving elements (m> n). That is, if the distance to the object on the optical axis 101A is measured, the image 106 by the lens 101 exists on the optical axis 101A regardless of the distance to the object.
Since the position of the image 107 formed by 2 changes according to the distance to the object, the CCD array 104 is provided with more light receiving elements than the CCD array 103. In such an arrangement, the CCD array 103 is referred to as the standard field of view and the CCD array 104 is referred to as the reference field of view.

The illuminance distributions in the standard visual field and the reference visual field as shown in FIG. 5 (a) are as shown in FIG. 5 (b). That is, the imaging relationship in the optical axis direction of the object 105 and the image 106 related to the lens 101 is equal to the imaging relationship in the optical axis direction of the object 105 and the image 107 related to the lens 102 (that is, the magnification is the same), so
The illuminance distribution of the copper 107 and the illuminance distribution of the copper 107 are different only in that they are displaced from the optical axis by a distance D.

Therefore, the CCD arrays 103 and 104 can provide outputs corresponding to the respective light receiving elements as shown in FIG. 5 (c).

Therefore, in order to correlate the outputs of the two CCD arrays, first, the outputs S of the first to nth light receiving elements in the reference field of view are output.
(1) to S (n) and the sum of the differences between the outputs corresponding to the outputs R (1) to R (n) of the first to nth light receiving elements in the reference field of view. Ask for. Next, similarly, the first to nth points in the reference visual field
Outputs S (2) to S (n) of the second light receiving element and outputs R (1) of the second to (n + 1) th light receiving elements in the reference field of view.
~ R (n + 1) sum of the difference between corresponding outputs Ask for. And so on Ask up to.

By selecting the COR number that has the smallest value (ideally 0) from the (m-n + 1) values thus obtained, and multiplying that number by the width of one light receiving element of the CCD array The value of D can be obtained.

As described above, when determining the distance D by the correlation method, a standard visual field having a certain size and a reference visual field larger than the standard visual field are required. As will be understood from the above description, when the distance measurement is performed over a wide distance range from infinity to short distance, the value of D becomes large at the time of short distance measurement, and thus the reference field of view is formed. CC
There is a problem that the number of light receiving elements of the D array needs to be increased considerably.

In order to solve such problems, CCD that constitutes the reference field of view
Japanese Laid-Open Patent Publication No. 61-116611 discloses that a CCD array having substantially the same number of light receiving elements as the reference visual field CCD array and movable along the baseline direction can be used to perform essentially the same distance measurement. Have been described. The publication also discloses a lens interval and a lens while maintaining a predetermined relationship.
It is disclosed that accurate measurement is performed in a focused state by changing the distance from the CCD array.

[Problems to be Solved by the Invention] By the way, in the distance measuring apparatus as described above, conventionally, movement of the lens and movement of the illuminance distribution measuring means are independently performed by using driving means such as a pulse motor. It was being done. For this reason, there is a problem that a separate control means is required to maintain the respective movement amounts in a predetermined relationship, which complicates the configuration.

Therefore, the present invention solves such a problem of the conventional technique, and moves both the lens and the illuminance distribution measuring means in a predetermined relationship with one driving source, thus facilitating the convergence adjustment in stereoscopic vision. With the goal.

[Means for Solving the Problems] According to the present invention, in order to achieve the above object, two optics having substantially the same focal length and arranged side by side such that their optical axes are parallel to each other. System and illuminance distribution measuring means juxtaposed corresponding to the optical system, the distance between the optical systems is relatively variable with respect to the distance between the illuminance distribution measuring means, and the illuminance distribution measuring means is It is movable in the optical axis direction relative to the optical system, and the direction between the two optical systems and the illuminance distribution measuring means is perpendicular to the plane formed by the optical axes of the two optical systems. The two optical systems are connected directly or indirectly by a crank lever that can rotate as an axis, and change the relative positional relationship between the optical system and the illuminance distribution measuring means with the rotation of the crank lever. And the above illuminance distribution measuring means Wherein the of have become as moving at least one congestion combined mechanism, is provided.

[Examples] Specific examples of the present invention will be described below with reference to the drawings.

1 (a) and 1 (b) are schematic views showing a first embodiment of a congestion matching mechanism according to the present invention.

In the figure, 11 is a lens barrel of the lens 1, and the lens barrel is fixed to a frame (not shown). Incidentally, 1A is the optical axis of the lens 1. A lens barrel 12 for the lens 2 is provided with a pair of accessory members 12a and 12b extending in the base line direction. The attached members are formed with elongated guide holes 13a and 13b extending in the base line direction. Reference numerals 14a and 14b are guide pins fixed to a frame (not shown), and these are fitted in the guide elongated holes 13a and 13b, respectively.
The lens barrel 12 is also provided with a guide pin 15 protruding in a direction (hereinafter, referred to as P direction) orthogonal to both the optical axis direction and the base line direction. The focal lengths of the lenses 1 and 2 are both F.

Reference numeral 16 is a crank lever, which is substantially orthogonal to each other 2
It has two arms 16a and 16b. The arm 16a extends substantially in the optical axis direction, and the arm 16b extends substantially in the base line direction. A rotating shaft 16c in the P direction is provided at the connecting portion of these two arms. The rotating shaft is rotatably connected to a frame (not shown). A guide elongated hole 17a extending in a direction toward the center of the rotating shaft 16c is formed at the tip of the arm 16a, while a direction toward the center of the rotating shaft 16c is formed at the tip of the arm 16b. A guide elongated hole 17b extending in the direction is formed. The guide pin 15 attached to the lens barrel 12 is fitted in the guide elongated hole 17a.

Reference numerals 3 and 4 denote CCD arrays having the same number of light receiving elements arranged corresponding to the lenses 1 and 2, respectively, and the CCD arrays are fixed to the support 18 along the base line direction. A guide pin 19 projecting in the P direction is attached to the support. The guide pin is fitted in the guide elongated hole 17b. Further, a guide elongated hole 20 extending in the optical axis direction is formed in the support 18. Reference numerals 21a and 21b are guide pins aligned in the optical axis direction and fixed to a frame (not shown), and the guide pins are fitted into the guide elongated holes 20.

In FIG. 1 (a), the center of the lens 1 and the center of the lens 2 are located at a distance L in the base line direction, and similarly, the center of the CCD array 3 and the center of the CCD array 4 are in the base line direction. The lenses 1 and 2 and the CCD arrays 3 and 4 are separated from each other by the focal length F of the lenses 1 and 2.

FIG. 1 (b) shows the crank lever from the state of FIG. 1 (a).
It shows a state in which 16 is rotated about the rotation axis 16c counterclockwise in the figure by an angle θ. By this rotation, the lens barrel 12 is moved toward the left side in the drawing by a distance ΔL in the base line direction based on the connection relationship between the guide elongated holes 17a and the guide pins 15 and the connection relationship between the guide elongated holes 13a and 13b and the guide pins 14a and 14b. Just move.
On the other hand, due to this rotation, the support 18 is connected to the guide elongated hole 17b and the guide pin 19 and the guide elongated hole 20 and the guide pin 19 are connected.
It moves in the optical axis direction by a distance ΔF downward in the figure based on the connection with 21a and 21b. In FIG. 1 (b), the distance between the lens 1 and the lens 2 is L '(= L-ΔL), and the distance between the lenses 1 and 2 and the CCD arrays 3 and 4 is F'.
(= F + ΔF).

Here, when the arm 16a of the crank lever 16 is in the optical axis direction,
From the center of the rotary shaft 16c of the crank lever 16 to the lens barrel 12
The distance from the center of the rotary shaft 16c to the center of the guide pin 19 attached to the support 18 is A · F, and the distance from the center of the rotating shaft 16c is A · F. A is a constant of proportionality).

In this case, if the rotation angle θ (radian) is small, it can be approximated as ΔL = A · L · θ ΔF = A · F · θ, and thus L ′ · F ′ = (LA−L · θ ) · (F + a · F · θ) = a ^{L · F-a 2 LFθ 2} . Then, when θ is small, A ² LFθ ² can be ignored, so that L ′ · F ′ = L · F can be approximated.

2 (a) and 2 (b) are the same as FIG. 1 (a) and FIG.
It is an optical diagram corresponding to the state of (b).

FIG. 2 (a) shows a case where the object 5 exists at infinity on the optical axis 1A. The images 6 and 7 of the object 5 on the CCD arrays 3 and 4 by the lenses 1 and 2 exist on the optical axis. And
The image is located in focus in the center of each of the CCD arrays 3,4.

2 (b) shows that the object 5 has a finite distance X on the optical axis 1A.
This is the case when they are located at a distance. In this case, the image 6 of the object 5 on the CCD array 3 formed by the lens 1 is the optical axis 1A.
It exists above, but the image 7 of the object 5 on the CCD array 4 by the lens 2 does not exist on the optical axis 2A. However, in this embodiment, when the crank lever 16 is rotated, ΔL and Δ are maintained while maintaining the relationship of L ′ · F ′ = L · F as described above.
Since F changes, the images 6 and 7 of the object 5 are CCD arrays, respectively.
It will be in focus in the center of 3 and 4.

The reason why an image is always focused on the center of the CCD array in this embodiment will be described below.

As described above, in FIGS. 2 (a) and 2 (b), L '.
Since F ′ = L · F, L · F = (L−ΔL) (F + ΔF) holds. Further, from the similarity relationship in FIG. 2 (b), (L−ΔL) / X = L / [X + (F + ΔF)] holds. From these equations, 1 / F = 1 / X + 1 / (F + ΔF) is derived. From this, it can be seen that the object 5 and the images 6 and 7 in FIG. 2 (b) satisfy the formulas for focusing images with respect to the lenses 1 and 2, respectively.

The movement of the lens 2 in the present embodiment can be driven by linearly reciprocating or rotating one of the lens barrel 12, the crank lever 16 and the support 18 in a predetermined direction by an appropriate drive means. .

FIG. 3 is a schematic diagram showing a second embodiment of the congestion matching mechanism according to the present invention. In this figure, the same members as those in FIG. 1 are designated by the same reference numerals.

In the present embodiment, the lens barrel 11 of the lens 1 can also move in the base line direction but in the opposite direction like the lens barrel 12 of the lens 2. That is, in association with the movement of the lens barrel 11, the attachment members 22a and 22b similar to the attachment members 12a and 12b, the guide elongated holes 23a and 23b similar to the guide elongated holes 13a and 13b, and the guide pin
Guide pins 24a, 24b similar to 14a, 14b, above guide pin 15
A guide pin 25 similar to the above, a crank lever 26 similar to the above crank lever 16, arms 26a and 26b similar to the above arms 16a and 16b,
A rotary shaft 26c similar to the rotary shaft 16c, the guide elongated hole 17a,
Long guide holes 27a and 27b similar to 17b, and the above guide pin 19
A guide pin 29 similar to the above is provided.

However, in the present embodiment, the ratio of the lengths of the two arms of the crank levers 16 and 26 is different from that in the first embodiment. That is, when the arm 16a of the crank lever 16 is in the optical axis direction, the distance from the center of the rotary shaft 16c of the crank lever 16 to the center of the guide pin 15 attached to the lens barrel 12 is A.
Let L / 2 be the distance from the center of the rotary shaft 16c to the center of the guide pin 19 attached to the support 18 as A and F (where A is a proportional constant), and similarly crank lever 26 When the arm 26a is in the optical axis direction, the distance from the center of the rotation shaft 26c of the crank lever 26 to the center of the guide pin 25 attached to the lens barrel 11 is A · L / 2 and the center of the rotation shaft 26c. From the center of the guide pin 29 attached to the support 18 to A · F.

As a result, the lenses 1 and 2 and the CCD arrays 3 and 4 can be moved relative to each other while maintaining the same relationship as in the first embodiment.

In the above embodiment, the guide elongated hole is formed at the tip of the arm of the crank lever, and the guide pin that fits with the guide elongated hole is formed on the lens barrel and the illuminance distribution measuring means supporting member. Alternatively, a guide pin may be formed on the crank lever, and a guide elongated hole that fits the guide pin may be formed on the lens barrel and the support. In this case, a guide slot in the optical axis direction is formed in the lens barrel, and a guide slot in the base line direction is formed in the support. In this case as well, it is possible to realize congestion matching substantially similar to that of the above embodiment.

[Effects of the Invention] According to the present invention as described above, it is possible to always use two driving sources.
It is possible to realize convergence adjustment in which two illuminance distribution measuring means form substantially the same visual field in a focused state, and when applied to distance measurement by the stereo method, control at the time of measurement becomes simple and The measurement accuracy can be improved.

[Brief description of drawings]

1 (a) and 1 (b) are schematic views showing a congestion matching mechanism according to the present invention. 2 (a) and 2 (b) are optical diagrams of the convergence adjusting mechanism according to the present invention. FIG. 3 is a schematic diagram showing a congestion matching mechanism according to the present invention. FIGS. 4A and 4B are diagrams for explaining the principle of the stereo method. 5 (a), (b) and (c) are diagrams for explaining the principle of the correlation method. 1,2: Lens, 1A, 2A: Optical axis, 3,4: CCD array, 5: Object, 6,7: Image, 11,12: Lens barrel, 16,26: Crank lever, 18: Support.

Claims (4)

[Claims] 1. An optical system comprising: two optical systems having substantially the same focal length and juxtaposed such that their optical axes are parallel to each other; and an illuminance distribution measuring means juxtaposed corresponding to the optical systems. The distance between the optical systems is relatively variable with respect to the distance between the illuminance distribution measuring means, and the illuminance distribution measuring means is movable in the optical axis direction relative to the optical system. The system and the illuminance distribution measuring means are directly or indirectly connected by a crank lever which is rotatable about a direction perpendicular to a plane formed by the optical axes of the two optical systems as an axis. At least one of the two optical systems and the illuminance distribution measuring means is moved so as to change the relative positional relationship between the optical system and the illuminance distribution measuring means with the rotation of the crank lever. Convergence matching, characterized by Structure. 2. When the optical system and the illuminance distribution measuring means move with the rotation of the crank lever, the product of the distance between the optical axes of the two optical systems and the distance between the optical system and the illuminance distribution measuring means is substantially constant. The congestion adjusting mechanism according to claim 1, wherein the congestion adjusting mechanism is maintained. 3. Only one optical system is movable in the base line direction, the distance between the rotation center of the crank lever and the point of action of the lever for moving the optical system, the rotation center of the crank lever and the lever. The ratio of the distance between the illuminance distribution measuring means and the point of action with respect to the movement in the optical axis direction is set to be substantially equal to the ratio between the distance between the two illuminance distribution measuring means and the focal length of the optical system. The congestion matching mechanism according to claim 2. 4. Two optical systems are both movable in the base line direction, and each optical system moves in the opposite direction with the movement of the illuminance distribution measuring means. With respect to the movement of each optical system, The distance between the center of rotation of the crank lever and the point of action for the movement of the optical system of the lever, and the distance between the center of rotation of the crank lever and the point of action for the movement of the illuminance distribution measuring means of the lever in the optical axis direction. The ratio is set to be substantially equal to the ratio of the half of the distance between the two illuminance distribution measuring means and the focal length of the optical system.
Convergence matching mechanism of term.