JP2019086361A - Detector and detection method - Google Patents

Abstract

To provide a detector with which it is possible to detect the state of each of a plurality of light-emitting diodes (LEDs) and improve the accuracy of detecting degradation or abnormality.SOLUTION: Provided is a detector for detecting the state of a plurality of light-emitting diodes of illumination means, the detector comprising illumination means capable of illuminating an imaging subject from various directions by the plurality of light-emitting diodes, and imaging means for imaging the imaging subject illuminated by the illumination means. An illumination inspection jig having mirror surface reflection characteristics and capable of illuminating by the illumination means is arranged. The imaging means is provided with a focus adjustment mechanism for focusing on each light-emitting diode. At the time of imaging of the illumination inspection jig, each light-emitting diode is imaged while each light-emitting diode is being focused on by the focus adjustment mechanism.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a detection apparatus, and more particularly to a detection apparatus and a detection method for detecting a deterioration state of a light emitting element in an apparatus (for example, an observation apparatus) using the light emitting element (LED).

  When inspecting articles (workpieces) such as various products, generally, an illumination system is used to image the articles. Examples of the illumination system include a simple illumination system as shown in FIG. 8 and a dome illumination system as shown in FIG.

  In the illumination system shown in FIG. 8, direct light from the LED 2 is applied to an article (workpiece) 1, and the image is captured by the camera 3. Moreover, the illumination system shown in FIG. 8 arranges a plurality of LEDs 2 along the concave surface 4 a of the dome member 4, and direct light from each LED 2 is applied to the article (work) 1, The camera 3 picks up the image. As described above, in the illumination system shown in FIG. 9, the irradiation directions of the plurality of LEDs 2 are arranged to be different from one another, and the work 1 to be imaged can be illuminated from all directions.

  By the way, LED2 has a life. Deterioration of the LED 2 causes a decrease in brightness, leading to a decrease in inspection accuracy, leading to a decrease in the reliability of the system (device). Therefore, in the related art, there is one that determines the degree of deterioration of the LED 2 based on the luminance of a captured image (Patent Document 1). That is, in this case, direct light (illumination light) from the LED 2 is applied to an imaging target to perform imaging, and the luminance value of the image is confirmed to detect a decrease in brightness due to deterioration of the illumination.

  Also, conventionally, a reflection area, which is an area of an input image captured by an imaging device, is detected, analysis of the reflection area is performed, and an abnormality of the illumination device and the imaging device There is also proposed one that detects That is, illumination is applied to the reflection plate for imaging, and the luminance of the image is confirmed to detect an abnormality of the illumination device and the imaging device.

JP 2007-265287 A JP, 2009-159568, A

  In Patent Document 1, a simple illumination system as shown in FIG. 7 is used. In such a case, the decrease in the illuminance due to the deterioration of the LED directly leads to the decrease in the luminance of the image. However, in this case, the LED itself was not imaged, and it was not possible to accurately grasp the deterioration or abnormality of the LED. Also in Patent Document 2, although a reflector is used, the LED itself is not imaged, and degradation or abnormality of the LED (variation, positional deviation and / or abnormality such as optical axis deviation) is accurately grasped I could not do it.

  By the way, when the dome illumination shown in FIG. 8 is used, as described above, the irradiation directions of the plurality of LEDs 2 are arranged to be different from one another, and the work 1 to be imaged can be illuminated from all directions. It has become.

  For this reason, the influence which each LED has on the brightness of a captured image is not uniform. For example, irradiation in a specific direction may affect the brightness of a captured image depending on the state or posture of the surface to be imaged. Therefore, it is difficult to recognize the deterioration or abnormality of a plurality of LEDs individually for each LED, and it is easy to miss.

  The present invention provides a detection device which can detect the state of each of a plurality of light emitting elements (LEDs) and can improve the detection accuracy of deterioration or abnormality in view of the above-mentioned problems.

  The detection apparatus according to the present invention is an observation unit including an illumination unit capable of illuminating an imaging target from various directions by a plurality of light emitting elements, and an imaging unit imaging an imaging target illuminated by the illumination unit. A detection device for detecting a state of a plurality of light emitting elements of the illumination means in the device, wherein a light inspection jig having specular reflection characteristics and capable of being illuminated by the illumination means is disposed, and the imaging means is provided A focus adjustment mechanism for focusing on the light emitting elements is provided, and at the time of imaging of the illumination inspection jig, each light emitting element is imaged in a state where the respective light emitting elements are focused by the focus adjustment mechanism. Here, the state of the light emitting element is an abnormal state such as a deteriorated state, a variation, an arrangement deviation, and / or an optical axis deviation.

  According to the detection device of the present invention, each light emitting element can be imaged by the imaging unit in a state where each light emitting element is focused by the focus adjustment mechanism. Therefore, the light emitting element itself can be imaged. Further, it is sufficient to arrange an illumination inspection jig capable of imaging with the illumination means of this observation device in an existing observation device or the like, and reflect the illumination inspection jig so as to project each light emitting element, The device can be easily configured without complication.

  The illumination means may direct light to the illumination inspection jig or may emit indirect light to the illumination inspection jig.

  The imaging means can display the images of all the light emitting elements in focus at one time, or can sequentially display the images of a predetermined number of light emitting elements in focus among all the light emitting elements. If it is projected at one time, the workability can be improved, and if it is projected sequentially, the image of each light emitting element can be projected more clearly, and detection with high accuracy becomes possible.

  It is preferable to have an image processing means for confirming the brightness of each light emitting element based on an image obtained by imaging the illumination inspection jig by the imaging means. In this case, the image processing means can be set to compare the image of each light emitting element in the initial state with the image of each light emitting element at the time of inspection. By comparing in this manner, it can be stably determined whether the light emitting element is deteriorated or the like.

  It comprises moving means for moving at least one of the illumination means side and the illumination inspection jig side to the illuminable position of the illumination inspection jig by the illumination means and the illuminable position of the imaging object by the illumination means. Are preferred.

  With this configuration, it is possible to switch between the illuminable state of the illumination inspection jig and the illuminable state of the imaging target. Therefore, normal observation of the imaging target and observation of the light emitting element can be performed, and furthermore, the illumination inspection jig does not inhibit observation of the normal imaging target, and the imaging target does not inhibit observation of the light emitting element.

  An inspection method according to the present invention is an observation method comprising: illumination means capable of illuminating an imaging object from various directions by a plurality of light emitting elements; and imaging means for imaging an imaging object illuminated by the illumination means A detection method for detecting the states of a plurality of light emitting elements of the illumination means in an apparatus, the illumination inspection jig having specular reflection characteristics and capable of being illuminated by the illumination means is disposed, and the illumination inspection jig Is imaged, and at the time of imaging of the illumination inspection jig, each light emitting element is focused, and in this state, each light emitting element is imaged to obtain an image of each light emitting element.

  According to the inspection method of the present invention, each light emitting element can be imaged by the imaging unit in a state in which each light emitting element is focused. Therefore, the light emitting element itself can be imaged.

  In the present invention, since the light emitting element itself can be imaged, it becomes possible to confirm an abnormality such as brightness (deterioration), variation, positional deviation and / or optical axis deviation of each light emitting element, and deterioration and abnormality The detection capability of is increased, and it is possible to identify the site of deterioration or abnormality, and to stably grasp the state (state) of these sites. In addition, by correcting the amount of lighting with respect to a light emitting element that is deteriorated or the like, the same brightness as the light emitting element that is not deteriorated can be obtained.

  In addition, the apparatus can be easily configured without complication and cost reduction can be achieved.

The detection apparatus which shows embodiment of this invention is shown, (a) is a simplified diagram of the state arrange | positioned in the illumination possible position of the imaging object by an illumination means, (b) is illumination of the illumination inspection jig by an illumination means. It is the simplification figure of the state arrange | positioned in the possible position, (c) is a simplification figure after focus adjustment. FIG. 2 is a simplified block diagram of the sensing device shown in FIG. It is a simplification figure of a screen in the state where each light emitting element is projected. It is a flowchart figure which shows the deterioration detection process using the detection apparatus shown in FIG. It is a flowchart figure which shows the abnormality detection process using the detection apparatus shown in FIG. FIG. 6 is a simplified view of another illumination means. FIG. 6 is a simplified view of another illumination means. FIG. 1 is a simplified diagram of a simple lighting system. It is a simplified view of dome lighting.

  Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 7.

  FIG. 1 shows an existing observation apparatus (inspection apparatus) equipped with a detection apparatus according to the present invention, and the existing observation apparatus is an illumination means capable of illuminating an imaging object with various light emitting elements 11 from various directions. 12 and an imaging means 13 for imaging the imaging object W illuminated by the illumination means 12.

  The illumination means (illumination system) 12 is a so-called dome illumination, and is arranged on a dome 15 whose inner surface is a concave surface 15a, and a printed circuit board (not shown) disposed along the concave surface 15a of the dome 15. And a plurality of light emitting elements 11. For example, the light emitting elements 11 are disposed on a plurality of concentric circles at a predetermined pitch along the circumferential direction. Specifically, as shown in FIG. 3 (this figure shows a screen in which the light emitting element 11 is shown as described later), the six concentric circles are arranged substantially without gaps in the circumferential direction. The printed circuit board is provided with a plurality of through holes, and the leads of the light emitting elements 11 are inserted and mounted on lands of the printed circuit board. Hereinafter, the light emitting element 11 may be referred to simply as the LED 11.

  Further, as the imaging means 13, for example, a CCD camera or a CMOS camera can be used. The imaging unit 13 changes the distance to the work W by moving closer to or away from the work W by the focus adjustment mechanism 21 (see FIG. 2) to obtain an image with different focal points in the vertical direction. it can. In this case, the element side may be moved, the lens system side may be moved, or the element side and the lens system side may be moved. Moreover, as a means to move, it can comprise by screw structure, for example. That is, the element side and / or the lens system side can be moved by moving the male screw side or the female screw side of the screw structure up and down by turning the operation knob.

  Further, as shown in FIG. 1, the imaging target W is disposed on the stage 16, and direct light from the illumination unit (illumination system) 12 is irradiated to the work W, and the imaging unit 13 disposed on the dome 15 The workpiece W can be projected through the observation window 15b of the dome 15. At this time, the camera can be focused on the work W by the focus adjustment mechanism 21.

  The detection apparatus according to the present invention includes, as shown in FIG. 2, an illumination inspection jig 20, an imaging unit 13 equipped with a focus adjustment mechanism 21, an image processing unit 22 and the like. The illumination inspection jig 20 is, as shown in FIG. 1, a convex spherical surface 20a having specular reflection characteristics and capable of being illuminated by the illumination means 12, and is disposed on the stage 16 on which the imaging target W is disposed. Ru. The illumination inspection jig 20 may be made of glass, plastic, or metal as long as it has a specular reflection characteristic.

  Further, the stage 16 on which the illumination inspection jig 20 and the imaging target W are arranged is an arrow from the state shown in FIG. 1A via the moving means 23 (see FIG. 2) as shown in FIG. It can slide in the A direction. Further, it can be slid in the direction of arrow B from the state shown in FIG. 1 (b) via the moving means 23, and can be returned to the state shown in FIG. 1 (a).

  In the state shown in FIG. 1 (a), it becomes the lightable position of the work W by the lighting means 12, and in the state shown in FIG. 1 (b) (c), it becomes the lightable position of the lighting inspection jig 20 by the lighting means 12. . For this reason, the moving means 23 moves the light inspection jig side to displace it to the lightable position of the work W by the lighting means 12 and the lightable position of the light inspection jig 20 by the light means 12. . The moving means 23 can be configured by, for example, various known and public mechanisms such as a cylinder mechanism, a ball screw mechanism, and a linear motor mechanism.

  Next, a method for detecting the state of the LED 11 by the detection device configured as described above will be described using FIGS. 4 and 1. In addition, as the illumination means 12, there exist abnormalities, such as degradation (fall of illumination intensity) of LED11, variation in the brightness for every LED11, arrangement shift, and / or optical axis shift. For this reason, in order to simplify the explanation, FIG. 4 shows a flowchart for detecting the LED 11 that is deteriorated (the illuminance is reduced).

  First, the illumination inspection jig 20 is set to a photographing possible position (illuminable position) (step S1). That is, the stage 16 is moved in the direction of arrow A as shown in FIG. 1B from the state shown in FIG. 1A, and the illumination means 12 and the imaging means 13 are positioned on the illumination inspection jig 20. State.

  Next, in step S2, the focus adjustment mechanism 21 focuses each LED 11. That is, light is directly applied from the LED 11 of the illumination means 12 to the illumination inspection jig 20, reflected by the illumination inspection jig 20, and the reflected light is incident on the imaging means 13. And the image of each LED11 is acquired as shown in FIG. 3 (step S3).

  Then, it transfers to step S4 and it is judged whether there is any LED11 which has deteriorated. In this case, the image of each LED 11 in the initial state and the image of the LED 11 at the time of inspection are compared. This comparison can be performed by the image processing means 22. As a processing method of the image processing means 22, for example, the brightness of the image of the LED 11 in the initial state (state not deteriorated) is 100, and the brightness of the image of the LED 11 at the time of inspection is a predetermined value or less with respect to 100. It is determined whether the image quality is lowered to the level below the predetermined value or not. In FIG. 3, the deteriorated LED 11 is dotted. The image processing means 22 can be configured, for example, by a microcomputer in which a ROM (Read Only Memory), a RAM (Random Access Memory), etc. are connected to each other via a bus, centering on a CPU (Central Processing Unit). Further, a storage device as the storage means is connected to the image processing means 22, and the storage device is an HDD (Hard Disc Drive), a DVD (Digital Versatile Disk) drive, a CD-R (Compact Disc-Recordable) drive And EEPROM (Electronically Erasable and Programmable Read Only Memory). The ROM stores programs and data to be executed by the CPU. The image of each initial LED 11 is stored in this storage device.

  If there is no degraded LED 11 in step S4, this detection process is ended. In addition, if there is an LED 11 that has deteriorated in step S4, the process proceeds to step S5, and it is determined whether the detection process is ended. When the detection process is ended, the process is ended. In this case, the position of the deteriorated LED 11 among the plurality of LEDs 11 is detected and the process ends.

  If the detection process is not completed in step S5, the process proceeds to step S6, and the light amount of the deteriorated LED 11 is corrected to match the brightness of the undeteriorated LED 11. After that, the process returns to step S4.

  Further, even if there is an abnormality such as a variation in brightness for each LED 11, a positional deviation, or an optical axis deviation, it can be detected by comparing the image of each LED 11 in the initial state with the image of this LED 11 at the time of inspection. These abnormalities can be detected according to the flowchart shown in FIG.

  Steps S7 to S9 in FIG. 5 are the same as steps S1 to S3 shown in FIG. In step S10, it is determined whether there is an abnormal LED 11. In step S10, if there is no abnormal LED 11, this detection process is ended.

  In step S10, if there is an abnormal LED 11, the process proceeds to step S11, and it is determined whether correction of the abnormal LED 11 is possible. That is, if it is the variation of the brightness for every LED11, it will be judged whether the variation can be eliminated, and if it is abnormality, such as a position shift or an optical axis shift, whether a correction of an arrangement or an optical axis can be canceled To judge. If it is determined in step S11 that the correction is possible, the process proceeds to step S12, and after the correction, the process returns to step S10. If it is determined in step S11 that the correction can not be made, this detection process is ended.

  In the present invention, since each light emitting element 11 can be imaged by the imaging unit 12 in a state where each light emitting element 11 is focused by the focus adjustment mechanism 21, the light emitting element 11 itself can be imaged. Therefore, it becomes possible to confirm abnormalities such as each brightness (deterioration), variation, positional deviation, optical axis deviation, etc. of the light emitting element 11, the detection capability of deterioration and abnormality becomes high, and the site of deterioration or abnormality is specified It is possible to stably understand the state of this part. In addition, by correcting the lighting light amount for the light emitting element 11 that is deteriorated or the like, it is possible to obtain the same brightness as the light emitting element 11 that is not deteriorated.

  Moreover, as a detection apparatus, the illumination inspection jig 20 which can be imaged with the illumination means 12 of this observation apparatus is arrange | positioned to the existing observation apparatus etc., It is made to reflect on this illumination inspection jig 20, Each light emitting element 11 Therefore, the apparatus can be easily configured without complication and cost reduction can be achieved.

  The image processing means 22 can be set to compare the image of each light emitting element 11 in the initial state with the image of each light emitting element 11 at the time of inspection. By comparing in this manner, it can be stably determined whether the light emitting element is deteriorated and / or whether or not an abnormality has occurred.

  By the way, in the above-mentioned embodiment, although the image pickup means 13 was made to project the image of all the light emitting elements 11 which made the focus at once, of the predetermined number of light emitting elements 11 which made the focus in all the light emitting elements 11 Images can be projected sequentially. If it is projected at one time, the workability can be improved, and if it is projected sequentially, the image of each light emitting element 11 can be projected more clearly, and detection with high accuracy becomes possible.

  Further, it is possible to switch between the illuminable state of the illumination inspection jig 20 and the illuminable state of the imaging target. Therefore, normal observation of the imaging target W and observation of the light emitting element 11 can be performed, and furthermore, the illumination inspection jig does not disturb observation of the normal imaging target W, and the imaging target W is the light emitting element 11. It does not inhibit the observation.

  By the way, in FIG. 1, although direct type dome illumination which can irradiate light to LED inspection jig 20 grade | etc., Directly from LED11 was used as the illumination means 12, As shown in FIG. 6, using internal reflection type dome illumination It is also good. In this case, a plurality of LEDs 11 are disposed along the circumferential direction on the inner side of the lower opening of the dome 15, and the irradiation light from the LEDs 11 is applied to the dome inner surface 15a, and reflected light (diffuse light ) Is applied to the light inspection jig 20 and the work W. Thereby, the image of the illumination inspection jig 20 and the work W can be obtained by the imaging means 13.

  For this reason, in the illumination means 12 shown in FIG. 6, indirect light is irradiated to the illumination inspection jig 20 and the work W. Even in such a case, the reflected light reflected by the illumination inspection jig 20 can be incident on the imaging unit 13. By this, it is possible to focus on the light emitting element by the focus adjustment mechanism, and it is possible to detect an abnormality such as deterioration of the LED 11, variation in brightness among the LEDs 11, positional deviation, or optical axis deviation.

  In FIG. 7, ring illumination is used as the illumination means 12. That is, in this case, a plurality of LEDs 11 are arrayed on the conical surface 30a of the ring body 30 having the conical surface 30a on the lighting inspection jig 20 side, and light can be directly emitted from the LEDs 11 to the lighting inspection jig 20 etc. .

  Therefore, even in such a case, the reflected light reflected by the illumination inspection jig 20 can be made to enter the imaging means 13. As a result, the light emitting element can be focused by the focus adjustment mechanism 21, and an abnormality such as deterioration of the LED 11, variation in brightness among the LEDs 11, positional deviation, or optical axis deviation can be detected.

  The present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, when switching between the illuminable state of the illumination inspection jig and the illuminable state of the imaging target, illumination means The stage 16 which is the lighting inspection jig 20 side is moved while fixing the 12 side, but conversely, the stage 16 which is the lighting inspection jig 20 side is fixed and the lighting means 12 side is moved Alternatively, the lighting unit 12 side and the lighting inspection jig 20 side may be moved. That is, it is sufficient to move at least one of the illumination means side and the illumination inspection jig side. In this case, the illumination means 12 side includes the illumination means 12 and the imaging means 13. When moving the illumination means 12 side, it is preferable to move at least the illumination means 12 and the imaging means 13.

  Further, the shape of the illumination inspection jig 20 has a specular reflection characteristic and can be illuminated by the illumination means 12, and direct light and indirect light from the illumination means 12 are reflected to enter the reflected light into the imaging means 13. Any shape may be used as long as it can emit light, and various shapes such as a sphere, a cone, and a pyramid (polyhedron) can be used. In the case of dome illumination as shown in FIG. 1, it is preferable that the reflection surface be a convex surface corresponding to the concave surface of the inner surface of the dome on which the LED 11 is disposed, and in the case of ring illumination as shown in FIG. Preferably, the reflecting surface is a conical surface similar to the conical surface on which the LED 11 is disposed. That is, as the illumination inspection jig 20, one having a reflecting surface having the same shape as the arrangement surface of the LED illumination of the illumination means 12 is preferable. Thus, if it has a reflective surface of the same shape as the arrangement | positioning surface of the LED illumination of the illumination means 12, the image of all LED11 can be acquired stably. In addition, as the illumination means 12, the number of LED11 and arrangement pitch etc. can be set arbitrarily.

  Moreover, in order to eliminate the illumination nonuniformity of LED illumination, it is preferable to arrange a diffusion plate (diffusion sheet). By arranging the diffusion plate (diffusion sheet) in this manner, it is possible to suppress the illumination unevenness and to improve the detection accuracy of the detection device and the inspection accuracy of the observation device. The diffusion plate (diffusion sheet) is made of polycarbonate, polyester, acrylic, glass or the like, has a fine uneven structure on the surface, and diffuses incident light at a certain angle by the refraction / diffraction action by the structure.

  In the embodiment described above, the image processing means 22 for confirming the brightness of each light emitting element 11 is provided, but without providing such an image processing means 22, the brightness is confirmed by visual observation by the operator. It may be

11 light emitting element (LED)
12 illumination means 13 imaging means 20 illumination inspection jig 21 focus adjustment mechanism 22 image processing means 23 moving means W work (imaging target)

Claims (9)

In the observation device, an observation apparatus comprising: illumination means capable of illuminating an imaging object from various directions by a plurality of light emitting elements; and imaging means for imaging the imaging object illuminated by the illumination means A detection device for detecting the states of a plurality of light emitting elements, wherein
An illumination inspection jig having specular reflection characteristics and capable of being illuminated by the illumination means is disposed, and the imaging means includes a focus adjustment mechanism for focusing on each light emitting element, and the imaging means is provided with an imaging mechanism. A detection device characterized in that each light emitting element is imaged in a state in which each light emitting element is focused by a focus adjustment mechanism.   The detection device according to claim 1, wherein the illumination unit emits light directly to the illumination inspection jig.   The detection device according to claim 1, wherein the illumination unit irradiates the illumination inspection jig with indirect light.   The detection device according to any one of claims 1 to 3, wherein the imaging unit projects an image of all the light emitting elements in focus at one time.   The detection device according to any one of claims 1 to 3, wherein the imaging means sequentially projects an image of a predetermined number of light emitting elements which are in focus among all the light emitting elements.   The image processing means which confirms the brightness of each light emitting element based on the image which the illumination inspection jig was imaged with the said imaging means was provided, The image processing means of any one of the Claims 1-5 characterized by the above-mentioned. Detection device.   7. The detection device according to claim 6, wherein the image processing means compares the image of each light emitting element in the initial state with the image of each light emitting element at the time of inspection.   It comprises moving means for moving at least one of the illumination means side and the illumination inspection jig side to the illuminable position of the illumination inspection jig by the illumination means and the illuminable position of the imaging object by the illumination means. The detection device according to any one of claims 1 to 7, characterized in that: In the observation device, an observation apparatus comprising: illumination means capable of illuminating an imaging object from various directions by a plurality of light emitting elements; and imaging means for imaging the imaging object illuminated by the illumination means A detection method for detecting the states of a plurality of light emitting elements, wherein
An illumination inspection jig having specular reflection characteristics and capable of being illuminated by the illumination means is disposed, and the illumination inspection jig is imaged, and at the time of imaging of the illumination inspection jig, each light emitting element is focused. In this state, each light emitting element is imaged to obtain an image of each light emitting element.

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