JP2007040732A - Inspection device, inspection method and cylinder inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device capable of reducing the installation load of an inspection target during inspection and capable of enhancing inspection precision and processing efficiency. <P>SOLUTION: This cylinder inspecting device 1 is constituted by providing a camera 5 above a cylinder 17 so as to be movable in a vertical direction and the cylinder 17 is supported so as to be rotated by a plurality of rollers 21. The cylinder 17 is simultaneously irradiated with red light and blue light from a red illuminator 9 and a blue illuminator 11 and the reflected lights from the cylinder 17 are imaged by the camera 5. An R-component image is extracted from one color image as a reference image while a B-component image is extracted as an inspection target image from the same color image and these R-component and B-component images are compared with each other to detect defectiveness. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inspection apparatus for inspecting the surface of a cylinder or a printing plate used for gravure printing or the like.

  2. Description of the Related Art Conventionally, a cylinder inspection apparatus that inspects a cylinder used for gravure printing or the like installs a cylinder at a predetermined inspection position by moving a driving portion in accordance with the diameter and width of the cylinder. In addition, a gravure cylinder inspection apparatus having means for changing a gravure cylinder from an inclined state to a horizontal state has been proposed (for example, see [Patent Document 1]).

  Regarding defect detection, a plate that captures cylinder surfaces using a line camera, counts the number of impositions of images in the captured image, compares the impositions, and detects defects such as pinholes and scratches. An inspection apparatus has been proposed (see, for example, [Patent Document 2]).

JP 2002-254590 A [Patent Document 2] JP 2004-170394 A

  However, in the conventional cylinder inspection apparatus, it is necessary to attach and detach the chucks on both side surfaces in order to cope with the sleeve-like cylinder and the shaft-like cylinder. Further, it is necessary to move the drive portion in accordance with the diameter and width of the cylinder.

  The gravure cylinder inspection apparatus shown in [Patent Document 1] has a problem in that since a camera is installed in the lower part of the cylinder, it is affected by dust and dust falling from the cylinder and the upper part, and a stable imaging environment is not obtained.

The plate inspection apparatus shown in [Patent Document 2] has a problem that the apparatus is expensive and large because it takes images of a cylinder using several high-precision line cameras. In addition, since images are input from a plurality of line cameras, a process for integrating a plurality of images is required to obtain one image.
Further, since imperfections are detected by comparing impositions from an image of a cylinder, there is a problem that image processing becomes complicated. In addition, there is a risk of misdetecting the registration marks and surface numbers added during imposition. In addition, there is a problem that it is impossible to cope with various imposition images.

  The present invention has been made in view of the above problems, and provides an inspection apparatus and the like that can reduce the installation burden of an inspection object at the time of inspection and improve inspection accuracy and processing efficiency. For the purpose.

  In order to achieve the above-described object, the first invention is an inspection apparatus that inspects the quality of the inspection object by performing image processing on the inspection image acquired by imaging the inspection object, and the inspection object A color component image is extracted for each of the different color components from an illuminating unit that irradiates an object with light of a plurality of different colors simultaneously, an imaging unit that images the inspection object, and a captured image captured by the imaging unit. An inspection apparatus comprising: a color component image extracting unit that detects a defect by comparing different color component images extracted by the color component image extracting unit.

  The inspection apparatus irradiates the inspection object with a plurality of different colors of light (lights of different wavelengths) simultaneously to image the inspection object, and extracts a color component image for each different color component from one captured image. Detecting a defect by comparing different color component images.

The inspection object is, for example, a gravure cylinder or a printing plate. In the case of a curved or flat surface having light reflectivity (in the case of a mirror surface), the effect in the defect detection process described later is significant.
The imaging device is a device that performs color imaging of an inspection target, for example, a color line camera.
The light of a plurality of different colors is, for example, red light (R) and blue light (B).
The inspection device, for example, irradiates the inspection object with red light and blue light simultaneously to capture reflected light, extracts an R component image as a reference image from the color captured image, and further inspects the inspection target from the same color captured image A B component image is extracted as an image, and the R component image and the B component image are compared to detect a defect.

  In the first invention, the inspection apparatus extracts an image for each wavelength of the irradiation light from one color captured image and simultaneously acquires the reference image and the inspection target image. Can be prevented. Further, the inspection apparatus can acquire an image in which only defects are extracted by performing a comparison process on these images. Further, since the inspection apparatus extracts defects by image processing using the same image, it is possible to detect defects even if not all images on the inspection object can be acquired.

  A second invention is an inspection method for inspecting the quality of the inspection object by performing image processing on an inspection image obtained by imaging the inspection object, and a plurality of different colors of light on the inspection object. Illuminating at the same time, an imaging step for imaging the inspection object, a color component image extraction step for extracting a color component image for each of the different color components from the captured image captured by the imaging step, A defect detection step of detecting a defect by comparing different color component images extracted by the color component image extraction step.

  2nd invention is invention regarding the inspection method which the inspection apparatus of 1st invention performs.

  3rd invention is a cylinder inspection apparatus which inspects the surface of the cylinder used for rotary printing, Comprising: The imaging means which images the surface of the said cylinder, The some roller which supports the said cylinder by line contact, The said roller A rotation drive means for rotating the image sensor, and a defect detection means for detecting a defect by performing image processing on an image captured by the image pickup means, the image pickup means being provided above the cylinder, A cylinder inspection apparatus that is movable in a vertical direction.

The cylinder inspection device includes an imaging device that images the surface of the cylinder, a plurality of rollers that support the cylinder, and a rotation drive device that rotates the rollers, and performs image processing on the captured image to detect defects.
The imaging device is, for example, a color line camera or the like, is provided above the cylinder, and is movable in the horizontal direction and the vertical direction.
The rotation drive device transmits a driving force from a rotation drive source (motor or the like) to a roller via a transmission medium (belt or the like).

In the cylinder inspection device according to the third aspect of the invention, the imaging device is provided downward above the cylinder, and the imaging device is provided so as to be movable in the vertical direction, so that it is affected by the type of cylinder, dust, dust, etc. And a stable imaging environment can be realized. Further, since the cylinder inspection device supports and rotates the cylinder with a plurality of rollers, the installation burden of the cylinder during inspection can be reduced.
For defect detection, the defect detection processing in the first invention and the second invention can be used.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the installation burden of the test target object at the time of a test | inspection, the test | inspection apparatus etc. which can improve test | inspection precision and processing efficiency can be provided.

  Hereinafter, preferred embodiments of a cylinder inspection apparatus and the like according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, the same reference numerals are given to components having substantially the same functional configuration, and redundant description will be omitted.

(1. Configuration of cylinder inspection device 1)
Initially, the structure of the cylinder inspection apparatus 1 which concerns on embodiment of this invention is demonstrated, referring FIG.1 and FIG.2.
FIG. 1 is a configuration diagram of a cylinder inspection device 1.
FIG. 2 is a perspective view of the main body of the cylinder inspection apparatus 1.

  The cylinder inspection device 1 includes a camera 5, a roller 21, a motor 25, a transmission medium 29, and the like. The cylinder inspection device 1 includes a control unit 37 (computer), a storage unit 39 (hard disk), an operation unit 41 (keyboard / mouse), a display unit 43 (display), an output unit 45 (printer), etc. It is connected via a connection line such as a bus or a cable.

The cylinder inspection apparatus 1 performs image processing such as comparison processing on the image captured by the camera 5 to inspect the surface of the cylinder 17 to be inspected, and displays the inspection result on the display unit 43 or outputs it to the output unit 45. To do.
The cylinder 17 is an original for gravure printing. The cylinder 17 has a recessed portion 19 on the surface. The recessed portion 19 is a recessed portion (cell) corresponding to an image of gravure printing. Gravure printing is performed by filling the recess 19 with ink and transferring the ink to paper or a resin film. In addition, it is desirable to provide a plurality of the same recessed portions 19 in one cylinder 17 so as to be multifaceted.
Further, the weight of the cylinder 17 may be 90 kg or more. The surface of the cylinder 17 is mirror-finished by processing such as chrome plating and has light reflectivity.

The camera 5 (color line camera) is a device that images the surface of the cylinder 17. The camera 5 is, for example, a camera (imaging device) including an optical sensor such as a CCD (Charge Coupled Device) in which light receiving elements (pixels) corresponding to RGB colors are one-dimensionally arranged, a drive circuit, an imaging optical system, and the like. .
The red illumination 9 is a light source that irradiates the surface of the cylinder 17 with red light. The blue illumination 11 is a light source that irradiates the surface of the cylinder 17 with blue light. The red illumination 9 and the blue illumination 11 are, for example, illuminators in which a plurality of LEDs are arranged in a planar shape.

  The camera 5, the red illumination 9, and the blue illumination 11 are provided on the fixing jig 7. The fixing jig 7 is provided on the vertical slide rail 13 so as to be movable in the vertical direction. The vertical slide rail 13 is provided on the horizontal slide rail 15 so as to be movable in the horizontal direction. Therefore, the camera 5, the red illumination 9, and the blue illumination 11 are movable in the vertical direction and the horizontal direction.

The roller 21 is a member that supports the cylinder 17. The roller 21 rotates about the roller shaft 23. A plurality of rollers 21 are provided and are in line contact with the cylinder 17 in the axial direction.
Regarding the length of the roller 21, for example, it is desirable that the length of the cylinder 17 be substantially the entire length. Regarding the shape of the roller 21, for example, a cylindrical shape is desirable. Regarding the material of the roller 21, it is desirable to determine the material of the roller 21 from the viewpoint of transmitting the rotational driving force and protecting the recessed portion 19. As the material of the surface of the roller 21, for example, an elastic material can be used.

The motor 25 is a driving source that applies a rotational driving force to the roller 21.
The transmission medium 29 transmits the rotational driving force from the motor 25 side to the roller 21 side. The transmission medium 29 is provided between the motor shaft 27 and the roller shaft 23. The transmission medium 29 is, for example, a belt or a chain. A transmission member such as a pulley or a sprocket may be provided on the motor shaft 27 and the roller shaft 23, and the transmission medium 29 may be hung on the transmission member.

  Frame members 33 are provided at both ends of the base member 31. A frame member 35 stands on the base member 31. The frame member 33 supports the end of the roller shaft 23 of the roller 21. The frame member 35 supports the horizontal slide rail 15.

  The control unit 37 performs image processing on the image data captured by the camera 5, and detects defects such as scratches and pinholes. The control part 37 can be comprised by the program etc. which operate a computer and the said computer as the control part 37 of the cylinder inspection apparatus 1, for example.

The storage unit 39 is a device that stores image data and the like. The storage unit 39 is, for example, a hard disk or a storage medium drive.
The operation unit 41 is a device that receives an operation instruction from an operator. The operation unit 41 is a pointing device such as a keyboard and a mouse, for example.
The display unit 43 displays a defect detection result or the like in the control unit 37. The display unit 43 is, for example, a CRT (Cathode Ray Tube) or an LCD (Liquid Crystal Display).
The output unit 45 outputs a failure detection result or the like in the control unit 37. The output unit 45 is, for example, a printer.

(2. Hardware configuration of control unit 37)
Next, the hardware configuration of the control unit 37 will be described with reference to FIG.
FIG. 3 is a diagram illustrating a hardware configuration of the control unit 37.

The control unit 37 shown in FIG. 3 is configured by connecting a CPU 51, a memory 53, and the like to each other via a system bus (not shown).
The control unit 37 is connected to the camera 5 via a network interface (not shown) or the like, and is connected to the display unit 43 via a video adapter (not shown) or the like.
Note that the hardware configuration shown in FIG. 3 is merely an example, and various configurations can be adopted depending on the application and purpose.

A CPU 51 (Central Processing Unit) stores a storage device, a ROM (Read Only Memory), an execution program stored in a recording medium, an OS (operation system) program, an application program, and the like on a work memory on a RAM (Random Access Memory). Called and executed in the area, performs arithmetic processing (four arithmetic operations, comparison operations, etc.), operation control of hardware and software, etc., and realizes various functions to be described later.
The memory 53 is a storage device such as a RAM or a ROM. An R component image memory 55, a B component image memory 57, a display memory 59, a work memory for executing a processing program, and the like are allocated to the RAM.

The R component image memory 55 is a memory for holding R component image data (R component image 63) extracted from image data captured by the camera 5.
The B component image memory 57 is a memory for holding B component image data (B component image 65) extracted from the image data captured by the camera 5.
The display memory 59 is a memory that holds display data to be displayed on the display unit 43, and holds, for example, image data indicating inspection results and defective portions.
The R component image memory 55, the B component image memory 57, and the display memory 59 may be provided independently in the control unit 37, or areas may be appropriately allocated on the RAM.

The CPU 51 determines pass / fail of the cylinder 17 to be inspected based on the R component image 63 and the B component image 65, and outputs the inspection result to the display memory 59.
The contents of the display memory 59 are input to the display unit 43 and displayed.

(3. Operation of camera 5 and roller 21)
Next, operations of the camera 5 and the roller 21 will be described with reference to FIGS. 4 and 5.

(3-1. Operation of Camera 5)
FIG. 4 is a diagram illustrating the operation of the camera 5.
The cylinder inspection apparatus 1 irradiates the cylinder 17 with red light and blue light from the red illumination 9 and the blue illumination 11, respectively. The camera 5 captures and captures the reflected light from the cylinder 17.

The fixing jig 7 is movable in the vertical direction along the vertical slide rail 13. Further, the vertical slide rail 13 is movable in the horizontal direction along the horizontal slide rail 15 (see FIGS. 1 and 2).
Therefore, the positions of the camera 5, the red illumination 9, and the blue illumination 11 can be adjusted according to the diameter and width of the cylinder 17. The cylinder inspection apparatus 1 can acquire imaging data over the entire length of the cylinder 17 by performing imaging while moving the camera 5 in the axial direction of the cylinder 17.
Further, since the position of the camera 5 is automatically set up and down according to the change in the diameter of the cylinder 17, the same image can be input regardless of the type of the cylinder 17.
The camera 5 is provided downward above the cylinder 17 to be inspected. Therefore, a stable imaging environment can be realized without being affected by dust from the cylinder 17 or from above.

(3-2. Operation of Roller 21)
FIG. 5 is a diagram illustrating the operation of the roller 21.
The cylinder 17 is placed on the two parallel rollers 21. The roller 21 supports the cylinder 17 in line contact.
When the motor shaft 27 of the motor 25 rotates, the rotational driving force is transmitted to the roller shaft 23 of the roller 21 via the transmission medium 29, and the roller 21 rotates. The motor 25 (motor shaft 27) and the roller 21 (roller shaft 23) rotate in the same direction (clockwise in FIG. 5), and the cylinder 17 rotates in the direction opposite to the roller 21 (roller shaft 23) (FIG. 5). Rotate counterclockwise.

  As described above, the rotation driving portion is provided at the end of the roller 21, and the cylinder 17 rotates axially when the plurality of rollers 21 rotate in the same direction. Therefore, the cylinder 17 can be rotated only by placing the cylinder 17 on the roller 21 regardless of the width, diameter, and type of the cylinder 17. Therefore, the installation burden of the cylinder 17 at the time of inspection can be reduced.

(4. Operation of cylinder inspection device 1)
Next, the operation of the cylinder inspection apparatus 1 in the defect detection process will be described with reference to FIGS.
FIG. 6 is a flowchart showing the operation of the cylinder inspection apparatus 1 in the defect detection process.
FIG. 7 is a diagram showing a flow of operation of the cylinder inspection apparatus 1 in the defect detection process.

The cylinder inspection apparatus 1 irradiates the recessed portion 19-1 of the cylinder 17 with red light (R) and blue light (B) from the red illumination 9 and the blue illumination 11, respectively (step 101).
The cylinder inspection device 1 captures the reflected light from the recessed portion 19-1 with the camera 5 and acquires the captured image 61 (step 102).
The cylinder inspection apparatus 1 extracts the R component image 63 and the B component image 65 based on the captured image 61 (step 103). In the R component image 63, the image line image 81 showing the image line portion 71 can be recognized, but the defective portion is not recognized. In the B component image 65, a defective image 83 showing the defective portion 73 is recognized together with the image line image 81. The defective portion 73 is a defect such as a pinhole or a scratch.

The cylinder inspection apparatus 1 compares the R component image 63 and the B component image 65, and detects a defective portion 73 in the recessed portion 19-1 (step 104).
The cylinder inspection apparatus 1 deletes the image line image 81 from the R component image 63 and the B component image 65, extracts only the defective image 83, and creates and displays a defective extracted image 67 (step 105).
The cylinder inspection apparatus 1 performs the processing of step 101 to step 105 sequentially for each of the recessed portions 19-1, 19-2,.

FIG. 8 is a diagram showing the reflected light in the cylinder 17.
Since the surface of the cylinder 17 is a mirror surface, the incident light is totally reflected at portions other than the recessed portion 19 and the reflected light toward the camera 5 is very small. The same applies to the portions other than the image line portion 71 of the recessed portion 19, and the amount of light traveling to the camera 5 out of the reflected light 92 of the incident light 91 is small.
Incident light 93 to the image line portion 71 is irregularly reflected and partly becomes reflected light 94 and travels to the camera 5. The line portion 71 is recognized as a line image 81.
Incident light 95 incident on the defective portion 73 is diffusely reflected and partly becomes reflected light 96 and travels to the camera 5. The defective portion 73 is recognized as a defective image 83.

In addition, the light quantity of the reflected light 96 in the defective part 73 changes according to the wavelength of light. In the blue light from the blue illumination 11, the amount of reflected light 96 is large. The defective portion 73 is recognized as a defective image 83 in the B component image 65. In other colors, for example, red light from the red illumination 9, the amount of reflected light 96 is small. The defective portion 73 is not recognized in the R component image 63.
Therefore, the cylinder inspection apparatus 1 extracts the R component image 63 as the reference image and the B component image 65 as the inspection target image from the color captured image of the single recessed portion 19.

  Through the above process, the cylinder inspection apparatus 1 simultaneously irradiates the cylinder 17 with red light and blue light, images the reflected light with the camera 5, extracts an R component image as a reference image from one color image, A B component image is extracted as an inspection object image from the same color captured image, and the R component image and the B component image are compared to detect a defect.

In this way, the cylinder inspection device 1 can prevent image shifts that occur during image processing by simultaneously capturing images (reference image and inspection target image) from two types of illumination from a color camera. .
Further, the cylinder inspection apparatus 1 extracts an R component image and a B component image from an image captured by a color camera, and performs a comparison process, a difference process, and the like on these two images to remove a defective portion ( An image obtained by extracting only scratches, pinholes, etc.) can be acquired.

Moreover, since the cylinder inspection apparatus 1 extracts defects by image processing using the same image, it is possible to detect defects even if not all images on the cylinder can be acquired. That is, it is not necessary to perform comparison processing with other impositions (other concave portions), and defect detection processing can be performed for each input image regardless of the image line portion or imposition. Therefore, the inspection process can be performed quickly and efficiently.
For example, in the defect detection process in the recessed portion 19-1, there is no need to capture images of the other recessed portions 19-2, 19-3,. Therefore, a plurality of cameras are not required. Further, it is not necessary to prepare a reference image separately and input it at the time of inspection.
In addition, since the cylinder inspection apparatus 1 performs processing using the same image, the same detection result can be obtained even in a place other than an image or an image line portion that fluctuates in imposition positions such as register marks and surface numbers. Can do.

(5. Effects, etc.)
As described above, in the embodiment of the present invention, the cylinder inspection device is provided with an imaging device (camera) movably in the vertical direction above the cylinder. A stable imaging environment can be realized without receiving. Further, since the cylinder inspection device supports and rotates the cylinder with a plurality of rollers, the installation burden of the cylinder during inspection can be reduced.

  In addition, the cylinder inspection device simultaneously illuminates two types of wavelengths, extracts images for each wavelength from one color captured image, and simultaneously acquires the reference image and the inspection target image. The resulting image shift can be prevented. In addition, the cylinder inspection apparatus can acquire an image obtained by extracting only defects excluding the image line portion by performing comparison processing, difference processing, and the like on these two images. In addition, since the cylinder inspection device extracts defects by image processing using the same image, it is possible to detect defects even if not all images on the cylinder can be acquired.

  In the above-described embodiment, the cylinder inspection has been described with respect to performing defect detection by simultaneously irradiating two types of wavelengths of illumination. However, the inspection target is not limited to the cylinder. It is also possible to inspect printing plates and the like. The shape to be inspected may be curved or flat. In addition, regarding the material to be inspected, the above-mentioned effect is particularly remarkable when the surface is a mirror surface, but it may be other than the mirror surface.

  The preferred embodiments of the cylinder inspection apparatus and the like according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

Configuration diagram of cylinder inspection device 1 Perspective view of cylinder inspection device 1 The figure which shows the hardware constitutions of the control part 37 The figure which shows operation | movement of the camera 5 The figure which shows operation | movement of the roller 21 Flow chart showing the operation of the cylinder inspection device 1 in the defect detection process The figure which shows the flow of operation | movement of the cylinder inspection apparatus 1 in a defect detection process. The figure which shows the reflected light in the cylinder 17

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inspection apparatus 5 ... Camera 7 ... Fixing jig 9 ... Red illumination 11 ... Blue illumination 13 ... Vertical slide rail 15 ... Horizontal slide rail 17 ... Cylinder 19 ......... Recessed portion 21 ......... Roller 23 ......... Roller shaft 25 ......... Motor 27 ......... Motor shaft 29 ......... Transmission medium 31 ......... Base members 33, 35 ......... Frame members 37 ... ...... Control unit (computer)
39 ……… Storage (hard disk)
41 ..... Operation part (keyboard, mouse)
43 ……… Display (display)
45 ......... Output section (printer)
61... Imaged image 63... R component image 65... B component image 67... Defective extracted image 71... Image portion 73... Defective portion 81. ... Defective images 91, 93, 95 .... Incident light 92, 94, 96 ..... Reflected light

Claims (10)

An inspection apparatus that performs image processing on an inspection image acquired by imaging an inspection object and inspects the quality of the inspection object,
Illuminating means for simultaneously irradiating the inspection object with a plurality of different colors of light;
Imaging means for imaging the inspection object;
Color component image extraction means for extracting a color component image for each of the different color components from the captured image captured by the imaging means;
A defect detecting means for detecting a defect by comparing different color component images extracted by the color component image extracting means;
An inspection apparatus comprising:   The inspection apparatus according to claim 1, wherein the plurality of different colors of light are red light and blue light.   The inspection apparatus according to claim 1, wherein a surface of the inspection object is a curved surface or a flat surface having light reflectivity. An inspection method for inspecting the quality of the inspection object by performing image processing on the inspection image acquired by imaging the inspection object,
An illumination step of simultaneously irradiating the inspection object with a plurality of different colors of light;
An imaging step of imaging the inspection object;
A color component image extraction step of extracting a color component image for each of the different color components from the captured image captured by the imaging step;
A defect detection step of detecting defects by comparing different color component images extracted by the color component image extraction step;
An inspection method comprising:   The inspection method according to claim 4, wherein the plurality of different colors of light are red light and blue light.   The inspection method according to claim 4 or 5, wherein the surface of the inspection object is a curved surface or a flat surface having light reflectivity. A cylinder inspection device for inspecting the surface of a cylinder used for rotary printing,
Imaging means for imaging the surface of the cylinder;
A plurality of rollers for supporting the cylinder by line contact;
Rotation driving means for rotating the roller;
A defect detection unit that performs image processing on a captured image by the imaging unit and detects a defect;
Comprising
The cylinder inspection apparatus, wherein the imaging means is provided above the cylinder and is movable in a horizontal direction and a vertical direction.   The cylinder inspection apparatus according to claim 7, wherein the cylinder and the roller are parallel in an axial direction, and the cylinder rotates as the roller rotates. Illumination means for simultaneously irradiating the cylinder with a plurality of different colors of light;
Color component image extraction means for extracting a color component image for each of the different color components from the captured image captured by the imaging means;
Further comprising
9. The cylinder inspection apparatus according to claim 7, wherein the defect detecting unit detects a defect by comparing different color component images extracted by the color component image extracting unit.   The inspection apparatus according to claim 9, wherein the plurality of different colors of light are red light and blue light.

Images