JP6014386B2 - Glass plate lighting device and processing device - Google Patents

Description

  The present invention relates to an illuminating device provided in an apparatus that converts an image acquired by a camera into an electrical signal and detects the shape and position of a glass plate that is a detection target by signal processing (image analysis), and such an illuminating device. The processing apparatus of the glass plate provided with this.

  When processing a glass plate carried into a processing machine with high accuracy, it is necessary to perform processing after detecting the position and orientation of the carried glass plate. For example, when processing the periphery of a glass plate, the glass plate is fixed and processed by vacuum suction or the like with the outer periphery of the glass plate protruding from the outer periphery of the table. If there is an error in the position or orientation of the glass plate carried on the table, accurate processing cannot be performed. Therefore, each time the glass plate is carried in, the position and orientation of the glass plate are detected, and the relative positional relationship between the table and the tool is corrected based on the detection result so that the glass plate is processed into an accurate shape. I have to.

  As one of means for detecting the position and orientation of the glass plate on the table, a camera is installed above the table and the image acquired by the camera is analyzed to detect the position and orientation of the glass plate on the table. Is widely used. Since the glass plate before processing is cut in advance to a predetermined size, the camera does not need to have a field of view for photographing the entire glass plate, and may have a field of view for photographing a part of the outer periphery of the glass plate, for example. It ’s fine.

  When acquiring an image of a glass plate with a camera, it is necessary to illuminate the visual field (photographing area) of the camera. Conventionally, a coaxial illumination that irradiates a glass plate with a light beam parallel to the optical axis of the camera and a ring illumination that illuminates the glass plate with a light source disposed around the camera are used as the illumination device. The coaxial illumination irradiates the glass plate with the light irradiated from the side of the optical axis of the camera toward the optical axis toward the optical axis by the half mirror. Then, the reflected light from the glass plate passes through the half mirror and forms an image on the image pickup device (CCD, CMos, etc.) of the camera. On the other hand, in the case of ring illumination, the glass plate is irradiated with a light source having a window in the center so as not to obstruct the path of light entering the camera from the glass plate, and the reflected light from the glass plate surface is reflected on the image sensor of the camera. To form an image.

  As another method, there is also used an illumination method in which a parallel light beam is irradiated obliquely on the glass plate surface, and the reflected light is received by a camera disposed obliquely opposite to the light source. However, in this method, the distance from the camera to the glass plate surface is not constant, and the camera cannot be focused on the entire field of view.

JP 2002-228774 A JP 2002-310938 A JP 2006-53030 A

  In the glass plate processing apparatus as described above, when a part of the periphery (for example, a corner) of the glass plate carried on the table is detected by the camera, the size of the glass plate carried in is large or small. Since the position of the periphery to be detected changes depending on the size of the glass plate, the position of the camera is moved according to the size of the loaded glass plate, or the periphery of all large and small glass plates is the field of view of the camera. It is necessary to use a camera with a large shooting area (wide angle) so as to enter.

  In the former method, the camera cannot be moved to an appropriate position unless the dimensions of the glass plate to be loaded are registered in the machine controller in advance, and the camera is moved each time the size of the glass plate changes. Therefore, the throughput (the number of processed parts per unit time) decreases. On the other hand, the method of widening the shooting area of the camera is capable of highly accurate detection without increasing the size of the camera because the degree of integration of the image sensor is high, but the lighting device is large. Problem arises.

  That is, when it is desired to widen the shooting area of the camera, if the coaxial illumination is adopted, the entire wide shooting area F cannot be illuminated uniformly unless the half mirror 73 is made large as shown in FIG. And since the surface light source 71 is installed in parallel with the optical axis of the camera 2, the illuminating device 7 becomes large and expensive.

  Therefore, the inventors of the present application conducted a test by adopting ring illumination in which a window through which a light beam to the camera passes is provided at the center. However, in the case of ring illumination, when the glass plate to be detected is a coated glass with a coating that suppresses surface reflection, an image of the glass plate can be obtained over the entire range of the imaging region. In the case of an uncoated glass, as shown in FIG. 7, a dark portion 75 is formed at the center of the acquired image 74, making it difficult to analyze the acquired image, and the glass at the center of the image. When the periphery of the plate came, there was a problem that the periphery of the glass plate could not be detected.

  This problem can be solved by increasing the light intensity of the light source so that the brightness of the glass plate can be detected even in the dark portion. Reflected light from the camera enters the camera and becomes a noise signal at the time of image processing, resulting in a new problem that signal processing becomes difficult and detection errors occur.

  This invention was made in order to solve the above-mentioned problems that occurred in a glass plate processing apparatus that sometimes processes a glass plate of raw glass. When detecting by analyzing the image of the plate, even if the object to be detected is bare glass, detection will not be hindered, and even if the shooting area of the camera is widened, the half mirror and lens will be enlarged. Therefore, it is an object to obtain a compact lighting device that can be easily mounted on a processing machine.

  The illuminating device 1 according to the present invention includes a surface light source 11 installed in parallel with the surface Ws of the glass plate to be illuminated, a window 14 provided substantially at the center of the surface light source 11 for allowing light to pass, and a window 14. And a second surface light source 12 that irradiates the illumination target Ws through the window 14 with the light reflected by the half mirror 13. The surface light source 11 and the second surface signal source 12 are realized by a surface light source, a light source composed of a large number of line light sources arranged in parallel, or a light source composed of point light sources arranged vertically and horizontally in a matrix.

  When acquiring an image to be illuminated, the camera 2 is installed on the side opposite to the illumination device 1 of the illumination device 1. That is, the illumination device 1 of the present invention is installed between the illumination target W and the camera 2 that acquires the image with the surface light source 11 parallel to the illumination target surface Ws. In this case, the surface light source 11 is a surface light source having a larger area than the imaging region F of the camera 2, and the second surface light source 12 is a surface light source having an area larger than the area of the window 14 provided in the surface light source 11. And

  The second surface light source 12 illuminates the illumination target through a half mirror 13 at a position farther from the illumination target than the surface light source 11. Therefore, in order to make the illuminance of the illumination target uniform, it is preferable to make the luminous intensity per unit area of the second surface light source 12 larger than that of the surface light source 11.

  The illuminating device of the present invention is particularly useful as a device for illuminating the glass plate when acquiring an image of a plate material having a smooth mirror surface, particularly a glass plate. Further, the illumination device of the present invention has an advantage that the illumination device can be made compact when the distance to the illumination target is relatively long. Therefore, it is particularly useful as a lighting device for detecting the position and orientation of a glass plate with a camera in a processing machine that processes the glass plate.

  The glass plate processing apparatus of the present invention includes a table 32, a processing tool 5 for the glass plate W fixed on the table 32, and a camera 2 that acquires an image of the peripheral edge of the glass plate W. Between the glass plate W, the illumination device 1 of the present invention is characterized in that the surface light source 11 is installed in parallel with the surface Ws of the glass plate.

  According to the present invention, it is possible to provide a compact illumination device that can uniformly illuminate a wide area without causing a partial increase or decrease in brightness when an image to be photographed is acquired by the camera 2. The illumination device of the present invention is particularly effective as an illumination device that illuminates the glass plate when the camera 2 detects the position and orientation of the glass plate W in the processing machine.

  The illuminating device of the present invention uses a camera to detect the position and orientation of a smooth glass plate that is stronger in specular reflection on the surface of the object to be detected than in other directions (irregular reflection), such as a glass plate of bare glass. It is particularly suitable as an illumination device for detection. That is, when the glass plate to be detected is a glass plate containing raw glass, by employing the illumination device of the present invention, it is possible to illuminate a large photographing area with a compact device without producing a dark portion.

  Therefore, the object to be detected may process various glass plates such as coated glass, raw glass, and glass with a positioning mark as a processing reference. In the case of detecting the position and orientation of the glass plate on the processing machine by analyzing the image taken in step 1, it is possible to provide a compact illumination device that can illuminate the entire wide field of view of the camera almost uniformly. Since there is no need to change the position of the camera due to the size of the glass plate, the throughput is improved and the illumination device is compact, so the field of view of the glass plate detection camera can be widened without increasing the size of the machine. it can.

Sectional side view which shows the Example of the illuminating device of this invention Side view showing an example of a processing apparatus provided with the illumination device of the present invention Explanatory drawing which shows the periphery process of the glass plate by the apparatus of FIG. Explanatory drawing which shows the detection of the angle | corner of the glass plate in the apparatus of FIG. The figure which shows the example of the image which the camera acquired in the state of FIG. Cross-sectional side view showing an example of a lighting device of another structure Explanatory diagram showing problems that occur with ring illumination

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the illumination device 1 of the present invention includes a surface light source 11 having a window 14 at the center, and a central axis (hereinafter referred to as “light”) of the window 14 on the side opposite to the light irradiation direction of the surface light source. And a second surface light source 12 for irradiating light from the side of the optical axis toward the half mirror. The camera 2 for photographing the glass plate W is installed on the side opposite to the optical window 14 with respect to the optical axis with the half mirror 13 interposed therebetween. The illuminating device 1 includes a case 23, and a surface 24 on the glass plate W side of the case 23 and a portion 25 through which incident light enters the camera 2 are formed of transparent low-reflection glass.

  The surface light source 11 shown in the figure is formed of a diffusion plate that diffuses the light of a large number of LEDs 15 arranged at equal intervals vertically and horizontally on a substrate 16 having an opening 17 in the center. Light is emitted from the LED, but the diffuser is the surface light source. Therefore, the window 14 is an opening or a transparent part provided in the center of the diffusion plate 11. Similarly to the surface light source 11, the second surface light source 12 in the figure is also formed of a diffusion plate that diffuses the light of a large number of LEDs 18 arranged at equal intervals in the vertical and horizontal directions on the substrate 19. The imaging region F, the surface light source 11 and the window 14 provided in the center thereof are rectangular shapes similar to the image receiving surface of the image sensor 22 of the camera 2.

  The positional relationship between the camera 2 and the surface light source 11 is preferably a positional relationship in which the light f directed from the edge of the photographing region F of the camera 2 toward the center of the lens 21 of the camera just passes through the edge of the window 14. In other words, the size of the window 14 is determined by the light f directed from the edge of the shooting area F of the camera determined by the viewing angle of the camera 2 and the distance from the lens center of the camera 2 to the glass plate W toward the lens center of the camera. It is good to make it the magnitude | size which passes the edge of the window 14 just. If the window 14 is smaller than this, the field of view of the camera is narrowed. If it is larger than this, the area of the second surface light source 12 must be increased.

  The size of the surface light source 11 is set to be equal to or larger than the size at which the specularly reflected light f of the light g irradiated from the outer edge to the edge of the photographing region F of the camera enters the camera 2 through the window 14. Therefore, the area of the surface light source 11 is wider than the area of the camera's shooting area. The substrate opening 17 may be sized so as not to block the light f.

  The light from the second surface light source 12 is reflected by the half mirror 13, irradiated to the glass plate W through the opening 17 and the window 14 of the substrate, reflected by the surface of the glass plate W, and the window 14 and the opening 17 of the substrate. , Passes through the half mirror 13 and enters the camera 2.

  The second surface light source 12 is at least capable of irradiating light h that is reflected by the half mirror 13 and passes through the edge of the window 14 and is regularly reflected by the surface of the glass plate W and incident on the lens center of the camera 2. Of a large size. When the second surface light source 12 is made larger than this, the light emitted from the enlarged portion illuminates the peripheral edge of the window 14 of the diffuser plate 11 and increases the luminous intensity of the surface light source 11 in this portion. However, the illuminating device becomes larger as the second surface light source 12 becomes larger. Therefore, the light emitting area of the second surface light source 12 is also preferably a rectangle similar to the imaging element 22 of the camera.

  FIG. 2 is a view showing an example of a peripheral processing apparatus for a glass plate provided with the illumination device of the present invention.

  In FIG. 2, a table 32 is fixed to the upper end of a table shaft 3 that is rotatably supported by a bearing 31 on a machine frame, and the upper surface of the table is a horizontal work holding surface 33. . The glass plate W carried into the work holding surface 33 is fixed to the table 32 by vacuum suction of the lower surface. A spindle motor (servo motor) 35 is connected to the lower end of the table shaft 3. The spindle motor 35 is connected to the controller 6 via a servo amplifier 61, and the rotation angle of the table shaft 3 is controlled by a command from the controller 6.

  A horizontal feed base 41 is provided above the table shaft 3. The lateral feed base 41 is movably guided by a horizontal lateral guide (not shown) provided on the machine frame, and is screwed to a lateral feed screw 44 that is rotationally driven by a lateral feed motor (servo motor) 43. The lateral feed motor 43 is connected to the controller 6 via the servo amplifier 62, and the movement position of the lateral feed base 41 is controlled by the controller 6.

  The horizontal feed table 41 is provided with a vertical feed table 45. The vertical feed table 45 is movably mounted on a vertical guide (not shown) in a direction parallel to the table shaft 3, and is screwed to a vertical feed screw 47 that is rotationally driven by a vertical feed motor 46.

  A grindstone shaft 51 is pivotally supported on the vertical feed base 45, and the grindstone 5 is mounted on the lower end of the grindstone shaft. The grindstone shaft 51 is supported by a bearing 52 in parallel with the table shaft 3. The upper end of the grindstone shaft 51 is connected to a grindstone drive motor 54 via a toothed belt 53.

  The axis of the table shaft 3 and the axis of the grindstone shaft 51 are located on the same vertical plane s parallel to the moving direction of the lateral feed base 41. FIG. 3 is a diagram schematically showing the outer peripheral processing of the glass plate W, and the controller 6 associates and controls the amount of movement x of the lateral feed base 41 and the rotation angle θ of the table shaft 3 to obtain a desired value. Performs peripheral processing of a planar shape.

  A camera 2 that acquires images of corners A and B of the glass plate on the table 32 is mounted on the lateral feed base 41. The camera 2 is fixedly provided on the lateral feed base 41 on a plane s including the axis of the grindstone shaft 51 and the axis of the table shaft 3. Under the camera 2, the illumination device 1 described in detail in FIG. 1 is installed.

  After the glass plate W is carried into the table 32 and fixed to the table 32, as shown in FIG. 4, the table 32 is rotated by an angle α with respect to the X axis of the diagonal line of the glass plate, which is known in advance. The corner A is made to enter the imaging area of the camera 2. Then, the camera 2 acquires an image of the first corner A. This image is, for example, as shown by the solid line in FIG. Next, the table 32 is rotated 180 degrees to acquire an image of the second corner B of the glass plate. This image is, for example, as shown by a broken line in FIG. When an image is acquired by the camera 2, the imaging region F of the camera is illuminated by the surface light source 11 and the second surface light source 12 of the illumination device 1.

  FIG. 5 shows a case where the corner of the glass plate is detected from the intersection of the boundary lines of the glass plate on the image acquired by the camera. The line segments a1, a2, b1, b2 and their intersections Ca, by an Hough transform method or the like for any two points on each of the two line segments a1, a2, b1, b2 of the solid line and the broken line, Coordinates on the Cb image can be acquired. Then, from the coordinates (bias) δx, δy in the x direction and y direction of the intersections Ca, Cb and the rotation angle α of the table, the deviation amount and the angular deviation amount of the center position of the glass plate W on the table 32 are obtained. Can do.

  The amount of deviation of the glass plate relative to the center of the table is detected every time the glass plate W is carried into the table 32, and the glass plate is processed using the correction value obtained for each glass plate.

  As described above, according to the illuminating device of the present invention, it is possible to uniformly illuminate a wide photographing area set in the camera 2 without generating a dark part, and the device is compact and the half mirror and the camera can be enlarged. Therefore, the position and orientation of the glass plate on the table 32 can be analyzed by analyzing the image taken by the camera 2 without changing the position of the camera 2 even if the size of the glass plate carried on the table 32 changes. It is possible to detect.

1 Lighting device 2 Camera
11 Area light source
12 Second surface light source
13 Half mirror
14 windows
32 Table W Glass plate Ws Glass plate surface

Claims (3)

A surface light source that is installed between a glass plate to be illuminated and a camera that acquires an image thereof, and has a larger area than the imaging region of the camera installed in parallel with the surface of the glass plate A window provided in the approximate center of the surface light source for allowing light to pass through, a half mirror installed on the opposite side of the window to be illuminated, and light reflected by the half mirror to be illuminated through the window An illumination device for a glass plate, comprising: a second surface light source having an area larger than an area of the window to be irradiated. The lighting device according to claim 1, wherein a luminous intensity per unit area of the second surface light source is larger than that of the surface light source . In a glass plate processing apparatus comprising a table, a glass plate processing tool fixed on the table, and a camera for acquiring an image of the peripheral edge of the glass plate,
 The processing apparatus of a glass plate provided with the illuminating device of Claim 1 or 2 installed with the said surface light source in parallel with the surface of the said glass plate between the said camera and the said glass plate.

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