JPH08227035A - Optical axis adjusting tool for camera - Google Patents

Abstract

PURPOSE: To provide an optical axis adjusting tool for a camera capable of easily adjusting the optical axis of the camera with respect to an image recognizing surface. CONSTITUTION: As to this optical axis adjusting tool 1 for the camera used to be placed on the image recognizing surface 52; this tool is used in the case of adjusting the position of an optical axis 12 of the camera, so that the optical axis 12 of the camera is perpendicular to the image recognizing surface 52 by moving the position of the camera 10. The tool 1 is provided with a first recognition part 2 for recognizing the perpendicularity of the optical axis 12 of the camera with respect to the surface 52 in a first direction X, a second recognition part 3 for recognizing the perpendicularity of the optical axis 12 of the camera with respect to the surface 52 in a second direction Y crossing with the first direction X, and a central display part M arranged on a central part at which the first recognition part crosses with the second recognition part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention adjusts the position of a camera, such as a video camera, for obtaining an image of an object with respect to the image recognition surface so that the optical axis of the camera is perpendicular to the image recognition surface. The present invention relates to an optical axis adjusting tool for a camera used when adjusting so that

[0002]

2. Description of the Related Art Some electronic component mounting machines, precision component assembling apparatuses, etc., are industrial cameras (objective cameras) for taking images of small electronic components when they are mounted on a printed circuit board, for example. ) Is provided. As described above, the camera is necessary for recognizing the position of the component to be mounted on the board by an image and specifying the position of the component to ensure the mounting of the component. This type of camera is set in a robot for handling parts, for example. The mechanical parallelism between the robot and the table for mounting the parts on the board is secured in advance, and the surface of the table for mounting the parts on the board is an image recognition surface for image recognition of the parts by the camera. Is.

[0003]

By the way, unless the optical axis of the camera is perpendicular to the image recognition surface, the camera cannot correctly recognize the positions of the parts. Conventionally, the perpendicularity of the optical axis of the camera with respect to the image recognition surface is attempted to be obtained by utilizing the mechanical relationship between the reference plane of the outer box of the camera body and the reference plane of the robot body. But,
The direction of the reference plane of the camera body and the direction of the optical axis of the camera are not completely the same and have an error. In some cases, the relationship between the reference plane of the camera body and the reference plane of the robot body cannot be measured. In this case, it is not easy to adjust the optical axis of the camera with respect to the image recognition surface.

Therefore, the present invention has been made to solve the above problems, and an object thereof is to provide an optical axis adjusting tool for a camera capable of easily adjusting the optical axis of the camera with respect to an image recognition surface. .

[0005]

According to the invention of claim 1, there is provided an optical axis adjusting tool for a camera mounted on an image recognition surface, wherein the camera is moved by moving the position of the camera. A first recognition part for recognizing the perpendicularity of the optical axis of the camera with respect to the image recognition surface in a first direction, which is a camera optical axis adjustment tool for making the optical axis perpendicular to the image recognition surface. And a second recognition portion for recognizing the perpendicularity of the optical axis of the camera to the image recognition surface in a second direction intersecting the first direction, a first recognition portion and a second recognition portion. A center display portion arranged at a central portion where the portions intersect. In the invention of claim 2, preferably, the first direction and the second direction are orthogonal to each other. In the invention of claim 3, preferably, the side surface of the first recognizing portion and the side surface of the second recognizing portion are formed perpendicularly to the bottom surface abutting the image recognition surface.

[0006]

According to the first aspect of the invention, the camera captures the image of the central display unit and aligns the optical axis of the camera with the central display unit. The camera captures the first recognition portion and adjusts the optical axis of the camera with respect to the image recognition surface with respect to the first direction based on the captured image of the first recognition portion.
Then, the camera captures the image of the second recognition portion, and adjusts the optical axis of the camera with respect to the image recognition surface also in the second direction based on the captured image of the second recognition portion. In the invention of claim 2, preferably the first
If the direction is orthogonal to the second direction, the user can more easily adjust the optical axis. In the invention of claim 3, since the side surface of the first recognition portion and the side surface of the second recognition portion are both formed perpendicular to the bottom surface, the first recognition portion captured by the camera. The inclination of the optical axis of the camera can be determined by whether or not the side surface of the camera and the side surface of the second recognition portion can be recognized on the image.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
It is not limited to these modes.

FIG. 1 shows a part of an image recognition surface 52 and an optical axis adjusting tool 1 of a camera of a preferred embodiment of the present invention. In FIG. 1, the optical axis adjusting tool 1 of the camera is a cross-shaped columnar member when viewed from above and is made of metal, plastic, or the like. The optical axis adjusting tool 1 of the camera includes a first recognition part 2, a second recognition part 3, and a center display part M.
It has. The first recognition portions 2 and 2 are portions for recognizing the perpendicularity of the optical axis of the camera in the first direction X (X1, X2). The first recognition parts 2 and 2 are
Each has a side surface 2a, 2a, 2a. This first
The side surfaces 2a, 2a, 2a of the recognition portions 2, 2 are precisely formed by machining so as to be perpendicular to the bottom surface 4 of the optical axis adjusting tool 1 of the camera. The second recognition parts 3 and 3 have side surfaces 3a, 3a and 3a, respectively. The side surfaces 3a of these second recognition parts 3 and 3,
3a, 3a are precisely formed by machining so as to be perpendicular to the bottom surface 4, respectively.

The upper surface 5 of the optical axis adjusting tool 1 of the camera shown in FIGS. 1 and 2 is formed parallel to the bottom surface 4 as shown in FIG. 3, and has a cross shape when viewed from above. . A center display portion M for optical axis alignment is provided at the center of the upper surface 5. The center display portion M is, for example, a mark displayed in a predetermined color. The optical axis adjusting tool 1 of the camera shown in FIGS. 1 to 3 has a size that fits within the field of view of the lens 11 of the camera 10 shown in FIGS.
It is preferable to prepare several types according to the type of the lens 11.

Next, a method of using the above-mentioned optical axis adjusting tool 1 of the camera will be described. First, as shown in FIG. 1, the bottom surface 4 of the optical axis adjusting tool 1 of the camera is placed in close contact with the image recognition surface 52. The image recognition surface 52 is, for example, the upper surface of the table of the electronic component mounting machine, on which electronic components, printed circuit boards, and the like are placed. The camera 10 whose optical axis is to be adjusted is set, for example, on the body of the robot (not shown), but the position of the camera of the camera 10 can be moved with respect to the robot body. As shown in FIG. 4, the upper surface 5 of the optical axis adjusting tool 1 of the camera is the camera 10
Facing to the side. The image of the optical axis adjusting tool 1 of the camera is captured by the camera 10 through the lens 11. At this time, FIG.
As illustrated in, the center of the optical axis 12 of the camera 10 is aligned with the center display portion M of the upper surface 5 of the optical axis adjusting tool 1 of the camera.

When the image of the optical axis adjusting tool 1 of the camera captured by the camera 10 of FIG. 5 is in the state shown in FIG. 6, the optical axis 12 of the camera 10 is the image recognition surface 5
Not perpendicular to 2. Therefore, work (1) and work (2) are performed so that the optical axis 12 of the camera 10 is perpendicular to the image recognition surface 52 as follows.
Need to be adjusted. Work (1) When the image of the optical axis adjusting tool 1 of the camera is obtained as shown in FIG. 6, the cross-shaped edges of the top surface 5 and the bottom surface 4 do not overlap each other, and in the example of FIG. Side portions 2a of the recognition portions 2 and 2,
2a, 2a and side surfaces 3a, 3 of the second recognition parts 3, 3
a and 3a are visible. These side surfaces 2a, 3
The optical axis 12 of the camera 10 of FIG.
Is modified as follows. That is, by tilting the camera 10 of FIG. 7 in the X1 direction or the X2 direction,
The side surfaces 2a, 2a, 2a of the first recognition portions 2, 2 are made invisible in the image. Next, in the camera 10 of FIG. 7, the side surfaces 3a, 3 of the second recognition portions 3, 3 are tilted by tilting the camera in the Y1 direction or the Y2 direction.
Make a and 3a invisible in the image. By doing so, the optical axis 12 of the camera 10 becomes 90 °.
The inclination of the optical axis 12 can be easily adjusted independently in each of the X direction and the Y direction having an angle of.

Work (2) After adjusting the optical axis 12 of the camera 10 in the X and Y directions, move the camera 10 in the direction shown by the arrow in FIG.
The optical axis 12 of the camera 10 is aligned with the center display portion M again. If the side surface 2a or 3a is still visible in the image with the optical axis 12 of the camera 10 aligned with the central display portion M, the above-described adjustment work (1) of the optical axis 12 of the camera 10 (1), ( It is necessary to repeat step 2). The adjustment operations (1) and (2) are repeated to perform side surfaces 2a, 2a, 2a of the first recognition portions 2 and 2 and the second recognition portions 3 and 2.
When the side surfaces 3a, 3a, 3a of 3 do not appear in the image at all,
The optical axis 12 of the camera 10 is perpendicular to the recognition surface 52. As described above, when the side surfaces 2a, 3a of the optical axis adjusting tool 1 of the camera disappear, the optical axis 12 of the camera 10 is perpendicular to the image recognition surface 52 as shown in FIG. In this state, the camera 10 is firmly fixed to the robot body.

By the way, as shown in FIG. 8, the optical axis adjusting tool 1 of the camera with respect to the mechanical reference plane 30 of the electronic component mounting machine.
May be obliquely arranged at a predetermined angle θ corresponding to the image recognition surface 52. The optical axis 12 of the camera 10 obliquely attached to the robot body can be adjusted using the optical axis adjusting tool 1 of this camera. The optical axis adjusting tool 1 of the camera described above should be installed on the image recognition surface 52 by a magnetic attraction force, for example, by a magnet, or set so as not to move due to attraction by negative pressure such as vacuum attraction. Is also possible. By thus setting the optical axis adjusting tool 1 of the camera on the image recognition surface 52, the camera 1
The optical axis 12 of 0 can be adjusted accurately and surely.
Further, even if the optical axis adjusting tool 1 of the camera of the present invention is arranged apart from the image capturing camera 10, the camera 1
The optical axis of 0 can be easily adjusted. By the way, the present invention is not limited to the above embodiments. For example, the optical axis adjusting tool of the illustrated embodiment has a cross-shaped pillar shape so that tilting of the optical axis with respect to the image recognition surface can be easily recognized, and the first recognition portions 2 and 2 and the second recognition portion are used. The parts 3, 3 are orthogonal. However, the first recognition parts 2, 2 and the second recognition parts 3, 3
Do not necessarily have to be orthogonal. Further, the optical axis adjusting tool is not limited to a cross-shaped one when seen in a plan view, and another shape can be adopted.

[0014]

As described above, according to the present invention, the optical axis of the camera with respect to the image recognition surface can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a perspective view showing a preferred embodiment of an optical axis adjusting tool of a camera of the present invention and a part of an image recognition surface.

FIG. 2 is a plan view of an optical axis adjusting tool of the camera shown in FIG.

FIG. 3 is a side view of an optical axis adjusting tool of the camera of FIG.

FIG. 4 is a diagram showing a state in which the position of the camera is corrected by trying to align the optical axis of the camera with the center display portion of the optical axis adjusting tool of the camera.

FIG. 5 is a diagram showing a state where the optical axis of the camera is tilted with respect to the optical axis adjusting tool of the camera.

FIG. 6 is a diagram showing an example of an image of the optical axis adjusting tool captured by the camera when the optical axis of the camera is tilted.

FIG. 7 is a diagram showing a state in which the optical axis of the camera is positioned perpendicularly to the image recognition surface by an optical axis adjusting tool of the camera.

FIG. 8 is a diagram showing an example of adjustment of an optical axis of a camera when the camera is obliquely attached to a reference plane.

[Explanation of symbols]

 1 Camera Optical Axis Adjustment Tool 2 First Recognition Part 2a Side of First Recognition Part 3 Second Recognition Part 3a Side of Second Recognition Part 4 Bottom 5 Top 52 Image Recognition Surface M Center Display Department

Claims (3)

[Claims] 1. An optical axis adjusting tool for a camera mounted on an image recognition surface for moving the position of the camera to make the optical axis of the camera perpendicular to the image recognition surface. A first recognizing part for recognizing the perpendicularity of the optical axis of the camera with respect to the image recognition surface in the first direction, and the perpendicularity of the optical axis of the camera with respect to the image recognition surface in the first direction. A second recognizing portion for recognizing in a second direction intersecting with the first recognizing portion, and a center display portion arranged at a central portion where the first recognizing portion and the second recognizing portion intersect with each other. An optical axis adjustment tool for a camera. 2. The optical axis adjusting tool for a camera according to claim 1, wherein the first direction and the second direction are orthogonal to each other. 3. The optical axis of the camera according to claim 1, wherein the side surface of the first recognition portion and the side surface of the second recognition portion are formed perpendicularly to a bottom surface that abuts the image recognition surface. Adjustment tool.