JP6500070B1 - Inspection equipment, lighting equipment for inspection - Google Patents

Abstract

An inspection apparatus capable of simply and accurately inspecting a printed image or the like is provided.
An inspection apparatus 1 according to the present invention includes an irradiation unit 3 (a control device 10) that irradiates a part of an image P with light from LEDs of three primary colors (red, green, and blue) in a predetermined order for each color. An image capturing unit 7 (control device 10) that captures each line of the image P for each irradiated color and a computer 15 are provided. The computer 15 generates color data obtained by combining the images captured by the imaging unit 7 for each color, then generates a full-color composite image from the color data, and measures the inspection items for the composite image.
[Selection] Figure 1

Description

  The present invention relates to an inspection device for inspecting color loss and positional accuracy of a printed image and the like, and an inspection illumination device used in the inspection device.

  2. Description of the Related Art Conventionally, an inspection apparatus for inspecting a printed matter for stains, uneven printing, ink density, and the like is known. For example, the inspection device of Patent Document 1 below receives three light emitting diodes that sequentially irradiate a printed material with light of three colors of red, green, and blue, and each reflected light amount from the traveling direction reflected from the printed material. The image pickup unit is formed by integrating a monochrome CCD camera that detects actual image data and a Fresnel lens provided below the monochrome CCD camera.

  The light emitted from the light emitting diode passes through the Fresnel lens and is reflected on the upper surface of the printed material, and finally collected by a monochrome CCD camera. The light emitting diode irradiates the printed matter with light at a pitch of about 0.6 mm, and the three-color separation is performed for a total of about 1.8 mm, and then the second line and the third line are irradiated.

  The principle is that red light emitting diodes are sensitive to indigo and ink, green light emitting diodes are sensitive to red, indigo and ink, and blue light emitting diodes are sensitive to yellow, red and ink. There is sensitivity. For this reason, when the amount of light reflected from the printed material is imaged by a monochrome CCD camera and processed by the signal processing unit, characteristic image data can be obtained. The obtained image data is taken into the comparison / calculation unit and compared with each reference image data prepared in advance to check for printing defects (paragraphs 0037 to 0044).

JP 2002-202266 A

  However, the inspection apparatus of Patent Document 1 has a problem that it takes inspection time because the image data corresponding to a predetermined area of the printed matter is separated into three colors, and the inspection accuracy is low. The present invention has been made in view of such circumstances, and an object thereof is to provide an inspection apparatus capable of simply and accurately inspecting a printed image or the like.

  The inspection apparatus according to the first aspect of the invention irradiates a part of the inspection target with light from the light sources of the three primary colors in a predetermined order for each color and each line of the inspection target. An image capturing unit that captures an image for each color, a storage unit that stores an image captured by the image capturing unit, and color data obtained by combining the images stored in the storage unit for each color are generated, and then the color data is A composite image generation unit that generates a full-color composite image by combining and a composite image measurement unit that measures an inspection item for the composite image are provided.

  In the inspection apparatus of the present invention, when the irradiation unit irradiates light of three primary colors (red, green, and blue) in a predetermined order on a part of an inspection target (for example, an image of a poster or the like), reflected light is obtained from the inspection target. . This reflected light has different components depending on the color of the irradiated light. Then, the imaging unit obtains an image of each line to be inspected for each color, and the image is stored in the storage unit.

  The composite image generation unit generates color data for each color from the image stored in the storage unit, and generates a full-color composite image based on the color data. In addition, the image measurement unit can detect inspection items (color shift, shading, etc.) for the composite image and detect defects to be inspected. Thereby, it is possible to easily and accurately inspect the inspection target.

  In the inspection apparatus according to the first aspect of the invention, it is preferable that the imaging unit is a monochrome line sensor camera.

  According to this configuration, by adopting the line sensor camera as the imaging unit, it is possible to image one line to be inspected with high pixels and increase the accuracy of the inspection. Further, by using a monochrome line sensor camera, the manufacturing cost of the apparatus can be reduced as compared with a color line sensor camera.

  In the inspection apparatus according to the first aspect of the present invention, it is preferable that the irradiation unit has an irradiation time of one color of light on a part of the inspection target of 100 μs or less.

  If the irradiation time of one color of light on a part of the inspection object is 100 μs or less, the irradiation time of three colors of light on this part is about 300 μs. Thereby, a high-speed inspection of the inspection object can be realized.

  In the inspection apparatus according to the first aspect of the present invention, the inspection target is further fixed to a stage unit, and further includes a stage drive unit that moves the stage unit at a constant speed when the light from the light source is irradiated by the irradiation unit. Is preferred.

  According to this configuration, the stage driving unit moves the stage unit at a constant speed when the irradiation unit irradiates light. Thereby, since the to-be-inspected object can be imaged for each line by the imaging unit while the irradiation unit is stationary, the accuracy of the inspection can be improved.

  A lighting device for inspection according to a second aspect of the present invention includes a light source of three primary colors, an opening for adjusting the shape of the irradiation light so that the light of the light source irradiates a part of the object to be inspected, and turning on and off the light of the light source. A light source control unit for controlling the light source, wherein the light source control unit controls the light source so that the irradiation time of one color of light on a part of the inspection target is 100 μs or less.

  In the inspection illumination device of the present invention, the light from the light source irradiates a part of the inspection target through the opening. The light source control unit controls the irradiation time of one color of light to a part of the inspection target to be 100 μs or less. Thereby, the reflected light for each color can be obtained at high speed from the object to be inspected.

The perspective view which shows the whole structure of the test | inspection apparatus of embodiment of this invention. The system block diagram explaining the connection relation of an inspection apparatus. The flowchart of the image taking process of an image taking device. FIG. 4 is a timing chart of the image capture process of FIG. 3. The figure explaining the synthesis | combination of a color image.

  Below, with reference to FIGS. 1-5, embodiment of the test | inspection apparatus of this invention is described.

  First, FIG. 1 shows the overall configuration of an inspection apparatus 1 that is an embodiment of the present invention. The image capturing device 2 of the inspection apparatus 1 mainly captures the irradiation unit 3 that irradiates the image P (the “inspection target” of the present invention) with light, the stage unit 5 on which the image P is placed, and the image P. The imaging unit 7 is configured. Further, the control device 10 that controls them is provided separately from the image capturing device 2 and is connected by a cable.

  The irradiation unit 3 is an illumination device that can emit light of three primary colors of R (Red), G (Green), and B (Blue). The irradiation unit 3 includes an LED control board 3 a (“light source control unit” of the present invention) in which the above three color LEDs (Light Emitted Diodes) are arranged, and emits light for each color according to a control signal from the control device 10. It can be performed.

  The casing of the irradiation unit 3 is provided with an elongated opening 3b substantially equal to the width (length in the x-axis direction) of the stage unit 5, and LED light is emitted from the opening 3b. The light from the LED irradiates a part of the image P (a rectangle long in the x-axis direction). The LED lighting switching speed is 100 μs, and the emission color can be switched at high speed.

  The stage unit 5 is provided in a pedestal 6 having a rectangular frame shape. The image P is placed on the upper surface of the stage unit 5, covered with a glass cover, and fixed. The stage unit 5 moves at a constant speed in the y-axis direction in the figure within the pedestal 6 when a stage driving unit 5a described later receives a control signal from the control device 10.

  The object to be inspected by the inspection apparatus 1 is mainly a printed matter such as a poster, but is not limited thereto. For example, it is possible to inspect a printed circuit board, a glass surface, a screen of a liquid crystal display device, and the like.

  The imaging unit 7 is a line sensor camera attached to the uppermost portion of the support unit 9 extending in the vertical direction (upward direction) from the inside of the base 6. The line sensor camera has a resolution as high as 16384 pixels per line because the imaging area is a line. For this reason, the image P can be captured with high accuracy line by line. The distance between the image P and the imaging unit 7 is 50 to 60 cm.

  The imaging unit 7 captures one line of the image P (y axis direction is about 20 μm). Since the lighting time of one color by the irradiation unit 3 is 100 μs, the time for scanning one line is about 300 μs. Considering this, the control device 10 moves the stage unit 5 at a constant speed and switches the emission color of the irradiation unit 3. Note that the scanning of all lines of the A4 sheet image is completed in about 4 seconds.

  When all the lines have been scanned, a color image is synthesized by the computer 15 (details will be described later). The imaging unit 7 of the present embodiment is a monochrome line sensor camera, but can generate a color image using dedicated firmware. A color camera may be used instead of the line sensor camera, but the manufacturing cost of the apparatus can be reduced by using a monochrome camera.

  The final color image (resolution: 1200 dpi) is displayed on a monitor (not shown) of the computer 15. The computer 15 measures and inspects a color image for geometric characteristics (size, squareness, parallelism, pitch, etc.), color shift, density linearity, dot volume, and the like. Further, an inspection for detecting a specific pattern by image comparison is performed. The inspection result can be confirmed on the monitor of the computer 15.

  Next, the system configuration of the inspection apparatus 1 will be described with reference to FIG.

  First, the control device 10 includes a control board 10a inside, and the control board 10a is USB-connected to the computer 15 with a cable C0. The control device 10 transmits the image data picked up by the image pickup unit 7 and stores it in the memory of the computer 15 (the “storage unit” of the present invention), or causes the dedicated firmware to generate a color image.

  The control device 10 is connected to the LED control board 3a by a power cable Pw1 and supplies power to the LED control board 3a. The control board 10a of the control device 10 is connected to the LED control board 3a by cables C1 (three), and controls each of the three primary colors LEDs ("light source" of the present invention) of the LED control board 3a.

  More specifically, each LED of the LED control board 3a is connected to a transistor, and on / off is controlled by a control signal from the control board 10a. When the LED control board 3a receives a transistor ON signal from the control board 10a, the irradiation unit 3 emits light corresponding to the ON transistor.

  The stage unit 5 is driven by a stage driving unit 5a. The control board 10a of the control device 10 is connected to the driver circuit 5b via cables C2 and C3, and the driver circuit 5b is connected to the stage drive unit 5a via cable C4. The control board 10a transmits a control signal synchronized with the stage drive signal as an irradiation signal of the irradiation unit 3 and an imaging signal of the imaging unit 7.

  The driver circuit 5b is also connected to a motor control board 15b of the computer 15. The stage driving unit 5a is a two-pulse motor, which rotates the motor forward by the CW pulse of the cable C2 and reversely rotates the motor by the CCW pulse of the cable C3. Thereby, the stage part 5 can be driven in a horizontal direction.

  The motor control board 15b of the computer 15 is connected to a PLC (Programmable Logic Controller) circuit 12 by a cable C5. The PLC circuit 12 is a circuit for the casing of the image capturing device 2. Although the image capturing device 2 shown in FIG. 1 is actually housed in the housing, the housing is opened by a predetermined operation from the computer 15.

  The control device 10 is connected to the imaging unit 7 via a power cable Pw2 and supplies power to the imaging unit 7. Further, the control board 10a of the control device 10 is connected to the image IF board 15a of the computer 15 by a cable C6. The control board 10a transmits a control signal to the imaging unit 7 via the image IF board 15a by a cable C7 which is a camera link cable. Thereby, the image P can be taken at a predetermined timing.

  Next, with reference to FIG. 3, a flowchart of image capturing processing by the image capturing device 2 will be described. The following processing is mainly performed by the control device 10 (hereinafter referred to as a control unit). The description will be supplemented with reference to FIGS. 4 and 5 as appropriate.

  First, the control unit starts image scanning (step S01). Specifically, the control unit moves the stage unit 5 on which the image P is fixed at a constant speed. This speed is just the speed at which the first line of the image P is shifted to the second line when steps S02 to S07 described below are completed. In the time chart of FIG. 4, this corresponds to the period between time t <b> 0 and t <b> 1 and imaging by the imaging unit 7 is not yet performed. However, in this step, irradiation by the irradiation unit 3 and preparation for imaging by the imaging unit 7 are completed. Thereafter, the process proceeds to step S02.

  In step S02, the control unit turns on the irradiation unit in red. Specifically, the red LED transistor of the LED control board 3a is turned on (the green LED and blue LED transistors are turned off). Thereby, red light is emitted from the irradiation unit 3 and a part of the image P is irradiated. In the time chart of FIG. 4, this corresponds to time t1. Thereafter, the process proceeds to step S03.

  In step S03, the control unit performs imaging by the imaging unit. That is, the image P is picked up by the image pickup unit 7 in a state where red light is emitted from the irradiation unit 3. In the time chart of FIG. 4, this corresponds to time t2. Thereafter, the process proceeds to step S04.

  In step S04, the control unit turns on the irradiation unit in green. Thereby, green light is emitted from the irradiation unit 3 and a part of the image P (the same part as when red light is emitted) is irradiated. In the time chart of FIG. 4, this corresponds to time t3. Thereafter, the process proceeds to step S05.

  In step S05, the control unit performs imaging by the imaging unit. Since the red LED transistor is turned off by this step, the image P is picked up by the image pickup unit 7 in a state where the image P is irradiated with the green light from the irradiation unit 3. In the time chart of FIG. 4, this corresponds to time t4. Thereafter, the process proceeds to step S06.

  In step S06, the control unit turns on the irradiation unit in blue. Thereby, blue light is emitted from the irradiation unit 3 and a part of the image P (the same part as when red light and green light are emitted) is irradiated. In the time chart of FIG. 4, this corresponds to time t5. Thereafter, the process proceeds to step S07.

  In step S07, the control unit performs imaging by the imaging unit. Since the transistor of the green LED is turned off by this step, the image P is picked up by the image pickup unit 7 in a state where the image P is irradiated with the blue light from the irradiation unit 3. In the time chart of FIG. 4, this corresponds to time t6. Thereafter, the process proceeds to step S08.

  Next, the control unit determines whether or not scanning for the designated number of lines has been completed (step S08). Here, the designated number of lines corresponds to the scan area of the image P. If the scan for the specified number of lines is completed, the process proceeds to step S09. If the scan for the specified number of lines is not yet completed, the process returns to step S02, and the processes in the subsequent steps (the process for the second line) I do.

  The image when the scanning of the designated number of lines is completed is as shown in FIG. 5A, and images of three colors (red, green, blue) are arranged in the order of lighting by the irradiation unit 3. LINEn (n = 1, 2, 3,...), Which is a combination of three colors, corresponds to one line of the image P.

  When the scan for the designated number of lines is completed (step S08: YES), the control unit generates image data for each color (step S09). This step corresponds to generating image data for each color shown in FIG. 5B (“color data” of the present invention) from the image of FIG. Then, it progresses to step S10.

  Finally, the control unit generates a color image (step S10). Specifically, the control unit combines the image data generated in step S09 to generate one full-color image (the “composite image” of the present invention). This step corresponds to generating a color image shown in FIG. 5C from the image data shown in FIG. As a result, a series of image capture processing is completed, and thereafter, the color image generated this time is inspected.

  As described above, in the inspection apparatus 1, when the stage unit 5 is moved at a constant speed, the irradiating unit 3 irradiates the image P with three colors of red, green, and blue, and the imaging unit 7 has three colors. One line of the image P is captured for each color. Further, the computer 15 generates image data obtained by combining the images captured by the imaging unit 7 for each color, then generates a color image from the image data, and further measures the inspection items for the color image. Thereby, the image P can be inspected easily and accurately and at high speed.

  The above embodiment is an embodiment of the inspection apparatus of the present invention, and various modifications can be considered besides this. For example, the lighting order of the LEDs by the irradiation unit 3 is not limited to the order of red, green, and blue shown in FIG. Even in other orders, the color image finally generated is the same.

  Although the irradiation time of one color of light by the irradiation unit 3 is 100 μs, it is preferably 100 μs or less. By reducing this time, the processing speed for one line of the image P is improved, leading to a reduction in the time for scanning the entire image P (the number of designated lines).

  DESCRIPTION OF SYMBOLS 1 ... Inspection apparatus, 2 ... Image capture device, 3 ... Irradiation part (inspection illumination apparatus), 3a ... LED control board (light source control part), 3b ... Opening part, 5 ... Stage part, 5a ... Stage drive part, 5b ... driver circuit, 6 ... pedestal, 7 ... imaging unit, 9 ... support unit, 10 ... control device, 10a ... control board, 12 ... PLC circuit, 15 ... PC (storage unit, composite image generation unit, image measurement unit) , 15a ... image IF board, 15b ... motor control board, C0 to C7 ... cable, P ... image, Pw1, Pw2 ... power cable.

Claims (5)

An irradiation unit that irradiates light from the three primary color light sources in a predetermined order for each color on a part of the inspection target;
An imaging unit that images each line of the inspection target for each irradiated color;
A storage unit for storing an image captured by the imaging unit;
A combined image generating unit that generates color data obtained by combining the images stored in the storage unit for each color, and then combines the color data to generate a full-color combined image;
An inspection apparatus comprising: a composite image measurement unit that measures an inspection item for the composite image. The inspection apparatus according to claim 1,
2. The inspection apparatus according to claim 1, wherein the imaging unit is a monochrome line sensor camera. The inspection apparatus according to claim 1 or 2,
The said irradiation part is an inspection apparatus characterized by the irradiation time of the light of one color with respect to a part of said test object being 100 microseconds or less. In the inspection device according to any one of claims 1 to 3,
The inspection object is fixed to the stage part,
An inspection apparatus, further comprising a stage drive unit that moves the stage unit at a constant speed when the light source emits light from the light source. Three primary color light sources,
An opening for adjusting the shape of the irradiation light so that the light from the light source irradiates a part of the inspection target;
A light source controller that controls turning on and off the light of the light source,
The inspection light device, wherein the light source control unit controls the light source so that an irradiation time of one color of light on a part of the inspection target is 100 μs or less.