JPH0468995A - Optical axis alignment device for ccd camera - Google Patents

Abstract

PURPOSE:To align an optical axis of a CCD image sensor element to a proper position of a CCD camera without position deviation at all times by using a discrimination section so as to apply electric discrimination to the degree of optical axis alignment. CONSTITUTION:A CCD camera is driven to display a picture of an object onto, e.g. a screen of a monitor, and a reference cross pattern is displayed on the screen of the monitor similarly to the case with the object picture by using an electric signal from a reference pattern generating section 13b. On the other hand, whether or not the picture of an object picture is matched with a reference pattern is discriminated by a discrimination section 13d and when the result of discrimination is unmatched, a discrimination signal is used to allow a control section 13f to control the display of the result of discrimination onto the monitor or the drive of operation motor for optical axis alignment screw. Thus, the degree of optical axis alignment is discriminated electrically by the discrimination section 13d, then the optical axis of the CCd image sensor element is aligned to a proper position without position deviation at all times because the personal difference of the optical axis alignment person is avoided.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is directed to the adjustment of the optical axis in the final manufacturing process of a CCD camera which is mainly used as a visual sensor of a VTR camera or an intelligent robot and constitutes an image processing system. This relates to equipment used for.

<Prior Art> Normally, in a CCD camera capable of optical axis adjustment, adjustment is performed to correct optical axis deviation in the final manufacturing process. Conventionally, such optical axis adjustment has been performed in the following procedure. That is, as shown in FIG. 11, a CCD camera 3 with an adjustment lens 3a attached is installed on the top of a mounting base 2 that stands vertically on a base 1, and the focal point of this camera is A subject 5 with an image attached thereto is fixed on a support 4 vertically disposed on a base 1 at a position spaced apart by a matching distance (generally about 1 m). And CCD camera 3
While looking at the image of the subject obtained from the image signal, the storage is performed according to the screwing degree of each of the four optical axis adjustment screws 3c screwed up, down, left and right when looking from the front side of the peripheral wall in the storage section 3b. The position of the CCD image sensor element incorporated in the section 3b in the vertical and horizontal directions is adjusted to correct the deviation of the optical axis.

However, in this first axis adjustment method, the subject 5 is
Due to the relatively large spacing of approximately 1 m from a, 0. Even a positional deviation of several millimeters causes a large error between the two, and it is necessary to accurately align the inclination, center, and vertical and horizontal positions between the structural optical axis center of the CCD camera 3 and the subject 5 three-dimensionally. be. Therefore, a precise mechanism is required, the configuration becomes complicated, and the entire device becomes large-scale and expensive.

In addition, when adjusting each CCD camera 3, each CCD
Even a slight difference in the accuracy of mounting the camera 3 on the mounting base 2 makes positioning difficult, which has the drawback of requiring complicated and difficult work.

Furthermore, when moving the optical axis adjustment mechanism to another location, there is a problem in that the above-mentioned complicated and difficult positioning work must be performed from the beginning.

Therefore, the present applicant has proposed a method for adjusting the optical axis of a CCD camera, which solves the various problems described above and allows the positional deviation of the optical axis to be easily corrected by simple operations using a simple device. (Japanese Patent Application No. 2-46680) That is, in this optical axis adjustment method, an object having a copy image whose center can be identified in the vertical and horizontal directions is rotatably attached to the front surface of the lens, and the rear surface of the lens is is connected to the front surface of a CCD camera via an extension cylinder long enough to display the copied image on the screen, and when the subject is rotated, the copied image is displayed on the CCD camera.
The CCD camera is positioned to have an appropriate positional relationship with respect to the camera, and the CCD camera is driven to project an image of the copied image on the screen, and a reference pattern is projected on the screen by an electric signal from a signal generator. This is carried out by moving a built-in CCD image sensor element to superimpose the image of the copy on the reference pattern.

<Problems to be Solved by the Invention> The above-mentioned optical axis adjustment method is an eyepiece in which a subject having a copy is attached to the front of the lens, and an elongated tube long enough to project the copy as an image is attached to the rear of the lens. Since the lens system is attached directly to the CCD camera, the adjustment device is simple and inexpensive, and the positional relationship between the copied image and the CCD camera is always constant, eliminating the need for complicated and difficult three-dimensional images. To eliminate position adjustment work, and to easily and accurately adjust the positions between a copy image and a CCD camera even if the optical axis is adjusted by moving to any location.

However, there are still problems that need to be resolved. That is, by loosening one of the four optical axis adjustment screws and screwing in the opposite side, the CCD image sensor element is moved in a direction in which the image of the copied image overlaps the reference pattern, and the image of the copied image is adjusted. Since the optical axis adjustment operator visually determines whether or not the pattern matches the reference pattern, there is a problem in that the degree of optical axis adjustment varies depending on individual differences among the operators. If this problem is solved, the above-mentioned optical axis adjustment means should have a very remarkable effect.

The present invention has been made in view of these points,
A technical object of the present invention is to provide an optical axis adjustment device that can always adjust the optical axis to a uniform degree regardless of the operator.

Means for Solving the Problems> In the present invention, as a technical means for achieving the above-mentioned problems, an optical axis adjustment device for a CCD camera is configured as follows. That is, a subject with a copy image whose center can be identified in up, down, left and right directions and the center is positioned and attached to the front of a CCD camera, and the CCD camera is driven to project the image of the copy on the screen, and the reference pattern is projecting a reference pattern on the screen using an electrical signal from the generating section;
A device for superimposing an image of the copy image on the reference pattern by displacing a CCD image sensor element built into the CCD camera, the apparatus comprising: comparing the image signal of the copy image and the reference pattern signal to determine whether they match; a determination unit that determines whether or not the optical axis adjustment screw is present, and outputs a determination signal based on the determination result; and a control unit that uses this determination signal to display the determination result on a monitor or to control driving of a motor for operating the optical axis adjustment screw. It is constructed with the following features.

For example, if a filter with a cross-shaped copy with the intersection point located at the center is used as the subject, this filter is rotatably attached to the front of the lens, and an extension tube is attached to the rear of the lens. After attaching this eyepiece system to the front of the CCD camera, use a suitable jig to align one of the cross-shaped lines of the copy image with the bottom of the CCD camera while rotating the filter. The filter is positioned relative to the CCD camera so that the filter is parallel to the CCD camera.

Then, the CCD camera is driven to display an image of the copy on, for example, a monitor screen, and a cross-shaped reference pattern similar to the copy is displayed on the monitor screen using an electrical signal from the reference pattern generator. On the other hand, the determination section determines whether or not the copy image matches this reference pattern, and if the determination result does not match, the determination signal output from the determination section is sent to the control section or the monitor for determination. Controls the display of results or the drive of the motor for operating the optical axis adjustment screw. For example, "NG" indicates a misalignment between the copy image and the reference pattern on the monitor screen.
is displayed, the adjustment operator adjusts the screwing degree of the four optical axis adjustment screws (top, bottom, left, and right) while looking at the screen, so that the image of the copy image approaches the reference pattern.
As the image sensor element is displaced, when the copied image exactly matches the reference pattern, a judgment signal from the judgment section that discriminates this indicates that the image matches the reference pattern.
"OK" will be displayed.

In this way, since the degree of optical axis adjustment is electrically judged by the determination unit, fluctuations due to individual differences in the optical axis adjustment person are eliminated, and the optical axis of the CCD image sensor element is always adjusted to an appropriate position without misalignment in the CCD camera. Can be adjusted to position.

<Example> Hereinafter, preferred examples of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a block configuration of an optical axis adjustment device 13 according to an embodiment of the present invention, and this optical axis adjustment device 13 converts an image signal of a copy image from a CCD camera 3 into a binary image signal. A binarization section 13a, a reference pattern generation section 13b that outputs a reference pattern signal similar to that of a copy image, and a binarization section 13.
an on-screen section 13c that superimposes the binary image signal of the copy image from a and a reference pattern signal; a 75Ω driver 13e that displays an image based on the output image signal of the on-screen section 13c on a monitor; and a binarization section 13a. The determination section 13d determines whether the binary image signal of the copied image matches the reference pattern signal and outputs a determination signal to the on-screen section 13c.

Next, a procedure for adjusting the optical axis using the optical axis adjustment device 13 of the embodiment described above will be explained. First, as shown in FIG. 2(a), a filter 7 with a cross-shaped copy 7a attached to a transparent or semi-transparent plate is attached to a lens 6 as shown in FIG. 2(b).
The lens 6 is rotatably attached to the front side of the lens 6 by screwing means or fitting means, and an elongated tube 8 is attached to the rear side of the lens 6 to form an eyepiece lens system. Incidentally, the copy image 7a is
The filter 7 is positioned so that the intersection point of the cross is located at the center of the filter 7, and the extension tube 8 is set to a length that allows the copy image 7a to be displayed on the screen.

Next, as shown in FIG.
Screw it onto the front side of the main body of the D camera 3, place it on the flat table 9 as shown in FIG. In addition, it is brought into close contact with the front side of the filter 7. This adjustment jig 10 is shown in FIG. 5(a).
Two lines 10a exactly perpendicular to the bottom surface as shown in
10b is attached at the same interval as the line width of the copy image 7a. Therefore, the two lines 10a, 10 of this adjustment jig 10
b is located perpendicular to the bottom surface of the flat table 9 and the CCD camera 3.

After connecting the CCD camera 3 to the monitor 12 via the connection cable 11 as shown in FIG.
Copy image 7a and two lines 1 obtained by driving the D camera 3
Images 7A, 10A, based on image signals 0a and 10b,
Display IOB on monitor 12. Now, two lines 10
When the copy image 7a is in the positional relationship with respect to the images a and 10b as shown in FIG. As shown in FIG. 5(C), the filter 7 is positioned so that any one line of the copy 7a fits between the two lines 10a and 10b.

As a result, the copy image 7a of the filter 7 is positioned so that its horizontal line is precisely parallel to the bottom surface of the CCD camera 3.

After positioning the filter 7 in this way, the adjustment jig 10 is removed and the CCD is placed as shown in FIGS. 1 and 7.
The camera 3 is connected to the binarization unit 13a of the optical axis adjustment device 13, and the driver 13e of the optical axis adjustment device 13 is connected to the monitor 12, so that the copied image 7 is displayed on the screen of the monitor 12.
A reference pattern 14 having a cross shape similar to the copy image 7a is displayed superimposed on the image 7A of a. The intersection of this reference pattern 14 is set to be at the same position as the intersection of the image 7A of the copy image 7a when the center of the light receiving part of the CCD image sensor element of the CCD camera 3 is accurately positioned at a predetermined position. . The above-mentioned means are similar to the optical axis adjustment method previously applied for.

On the other hand, the determination section 13d of the optical axis adjustment device 13 compares the image signal of the copy image 7a with the reference pattern signal to determine whether or not they match, and transmits the determination signal of the determination result to the on-screen section. Output to 13c. now,
When the image 7A of the copy image 7a is shifted from the reference pattern 14 as shown in FIG. via monitor 12
On the screen, the judgment result “NG” indicating a discrepancy is displayed and Image 7
An arrow showing the direction in which A should be moved is displayed.

Based on this display, by adjusting the screwing degree of each of the four optical axis adjustment screws 3C provided on the top, bottom, left and right sides of the storage section 3b when viewed from the front of the CCD camera 3, the image of the copy image 7a is When the CCD image sensor element is displaced so that the image 7A moves in a direction approaching the reference pattern 14 according to the above-mentioned display arrow, the image 7A of the copy 7a moves closer to the reference pattern 14 as shown in FIG. 8(b). At the point in time when there is an exact match, a judgment signal from the judgment unit 13d that judges this indicates that there is a match [OKJ] is displayed. Since the degree of optical axis adjustment is electrically determined by the determination unit 13d in this way, variations due to individual differences in the judgment of the optical axis adjuster are eliminated, and the optical axis of the CCD image sensor element is always misaligned in the CCD camera 3. Can be adjusted to the appropriate position without any problems.

After completing the adjustment, remove the eyepiece system and connection cable 11 from the CCD camera 3, and then connect each CCD using the same procedure.
The optical axis of the camera 3 is sequentially adjusted. In this optical axis adjustment means, a filter 7 having a cross-shaped copy 7a positioned around the intersection point is attached to the front of the lens 6.
In addition, an elongated tube 8 having a length that allows the copied image 7a to be projected on the screen is attached to the rear surface of the lens 6 to constitute an eyepiece system, and this eyepiece lens system is attached to the CCD camera 3, so that the copied image 7a can be seen on the CCD camera 3. On the other hand, since the copy image 7a and the CCD camera 3 are integrated without being separated as in the conventional case, and the positional relationship between the copy image 7a and the CCD camera 3 is always constant, the interaction between the copy image 7a and the CCD camera 3, which is complicated and difficult in the conventional case, is avoided. Moreover, the mutual positional adjustment between the copy image 7a and the CCD camera 3 can be easily and accurately performed even if the optical axis is adjusted by moving to any location.

In addition, as another embodiment of the present invention, as shown in the front view of FIG. 9 and by dashed lines in FIG. Optical axis adjusting motors 15a to 15d are installed so that the optical axis adjusting screws 3c can be adjusted individually, and as driving means for these, motor control is performed on the optical axis adjusting device 13 as shown by the dashed line in FIG. A section 13f and a driver 13g are provided, and the determining section 13d outputs a determination signal indicating the direction and magnitude of positional deviation between the image 7A of the copy 7a and the reference pattern 14 to the motor control section 13f. Thereby, optical axis adjustment can be performed automatically.

Now, if the image 7A of the copy image 7a and the reference pattern 14 are out of alignment as shown in the screen of the monitor 12 shown in FIG. is created, and each motor 15a to 15d is driven and controlled as follows via a driver 13g.

That is, first, the vertical movement motors 15a, 15c are rotationally controlled to loosen the upper and lower screws 3c, thereby making the CCD image sensor element movable in the horizontal direction. Next, the motor 15 for left and right movement
One of the elements b and 15d is rotated in the forward direction, and the other is rotated in the opposite direction, and the CCD image sensor element is rotated to produce an image 7A of the subject 7a.
is displaced so that it moves in the direction of the arrow in FIG. Then, as shown in FIG. 8(b), an image 7A of the copy 7a is
When each vertical line between and the reference pattern 14 matches,
The motors 15b and 15d are stopped based on the determination signal.

Next, after returning the screwing degree of the upper and lower screws 3c to the original state, the motors 15b and 15d for left and right movement are rotationally controlled to loosen the screwing degree of the left and right screws 3c. The image sensor element becomes movable in the vertical direction. Next, the motors 15a, 1 for vertical movement
5c is rotated forward, and the other is rotated backwards.
The image sensor element D is displaced so as to move downward from the image 7A of the subject 7a as shown by the arrow in FIG.

Then, as shown in FIG. 8(C), the image 7 of the copy 7a is
When the horizontal lines of A and the reference pattern 14 match, the motors 15a and 15c are stopped. Thereafter, the threading degree of the left and right screws 3c is returned to the original state, and the CCD image sensor element is fixed.

<Effects of the Invention> As described above, according to the optical axis adjustment device for a CCD camera of the present invention, since the degree of optical axis adjustment is electrically determined by the judgment unit, variations due to individual differences in the judgment of the optical axis adjustment person can be avoided. No longer a CCD image sensor - the optical axis of the element is always CC
The D camera 3 can be reliably and stably adjusted to an appropriate position without displacement.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 (
a) and (b) are front and right side views of the eyepiece system used before use of the present invention, Figure 3 is a right side view of the eyepiece system attached to a CCD camera, and Figure 4 is the same. A right side view of the positioning of the eyepiece system relative to the CCD camera, Figures 5 (a), (b), and (C) are explanatory diagrams of the adjustment procedure in Figure 3, and Figure 6 is an illustration of the adjustment procedure of the same optical axis. Fig. 7 is a block diagram of the state in which the device in Fig. 1 is connected, and Fig. 8 (
a) and (b) are diagrams showing monitor screens showing the optical axis adjustment procedure according to FIG. 7, FIG. 9 is a front view of another embodiment of the present invention, and FIG. 10 (a)
, (b) and (C) are diagrams showing monitor screens showing the optical axis adjustment procedure according to FIG. 9, and FIG. 11 is a configuration diagram of a conventional optical axis adjustment means. 3... CCD camera 7... Subject 7a... Copy image 7A... Copy image 12... Monitor 13... Optical axis adjustment device 13b... Reference pattern generating section 13c... On-screen section (display control section) 13d.
...Determination section 13f...Motor control section (control section) 14...Reference pattern 15a to 15d-...Motor

Claims (1)

[Claims] (1) Position and attach a subject with an image whose center can be identified in the up, down, left and right directions and center on the front of a CCD camera, and drive the CCD camera to project an image of the subject on the screen. , an optical axis adjustment method in which a reference pattern is projected on the screen by an electric signal from a reference pattern generator, and a CCD image sensor element built in the CCD camera is displaced to superimpose an image of the object on the reference pattern. The device to be used includes a determination unit that compares the image signal of the subject and the reference pattern signal to determine whether they match, and outputs a determination signal based on the determination result; 1. An optical axis adjustment device for a CCD camera, comprising a control unit that displays determination results on a monitor or controls driving of a motor for operating an optical axis adjustment screw.