Workpiece Imaging System

Abstract

To provide a workpiece imaging system that can execute workpiece alignment and identification of a mark on a workpiece by switching between different lighting devices.SOLUTION: A workpiece imaging system comprises: a holding unit that holds a workpiece in contact with a holding surface in an imaging area; a first radiation unit that radiates first irradiation light in a wider range than the workpiece toward a surface of the workpiece from a direction opposite to the holding surface holding the workpiece; a second radiation unit that radiates second irradiation light from the back face of the workpiece toward an identification part of the workpiece through a light transmission part of the holding unit; a selection unit that causes at least either one of the first radiation unit or the second radiation unit to radiate light toward the workpiece; and an imaging unit that is arranged opposite to the workpiece, receives the first irradiation light reflected on the workpiece to pick up an image of the contour of the workpiece, and receives the second irradiation light transmitting through the workpiece to pick up an image of identification information on the workpiece.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a workpiece imaging system, and more particularly to a workpiece imaging technique for optically reading the outer shape and identification information of a workpiece. [Background technology]

[0002] As an example of this type of system, Patent Document 1 describes a system that aligns a liquid crystal panel and obtains identification information based on the image capture results of a camera. In detail, the alignment of the liquid crystal panel is performed by capturing an image of part of the outer shape of the liquid crystal panel with a camera. At that time, reflected light from a reflector is used as illumination. Meanwhile, data (identification information) of the liquid crystal panel is captured and read by a camera different from the camera used for the above alignment.

[0003] In the system of Patent Document 1, a positioning camera captures an image of part of the outer shape of the liquid crystal panel to obtain position information. After that, the liquid crystal panel is moved by a moving mechanism, and a data reading camera captures an image of the data of the liquid crystal panel to obtain identification information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-010273 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the technology described in Patent Document 1, a camera that captures the external shape of the liquid crystal panel and a camera that captures the identification information of the liquid crystal panel are positioned with the panel movement mechanism in between, which creates the problem of a complex system configuration, particularly in relation to lighting.

[0006] An object of the present invention is to provide a workpiece imaging system that is capable of acquiring the outer shape and identification information of a workpiece simply by switching the lighting for the camera. [Means for solving the problem]

[0007] In order to achieve this object, one aspect of the workpiece imaging system of the present invention includes a housing that defines an imaging area in an internal space,

[0008] a conveying unit that conveys the workpiece to the internal space while holding the workpiece on a holding surface and places the workpiece in the imaging area;

[0009] A first irradiation unit that irradiates a first irradiation light from a direction facing the holding surface of the holding unit toward a surface of the workpiece, over a wider area than the workpiece;

[0010] A second irradiation unit that irradiates a second irradiation light from the back side of the workpiece toward an identification portion of the workpiece through the light transmitting portion of the holding unit;

[0011] A selection unit that irradiates light from either the first irradiation unit or the second irradiation unit toward the workpiece;

[0012] and an imaging unit that is disposed opposite the workpiece, receives the first irradiation light reflected by the workpiece to image the outer shape of the workpiece, and receives the second irradiation light that has passed through the workpiece to image the identification information of the workpiece. Effect of the Invention

[0013] According to one aspect of the present invention, in a workpiece imaging system, it is possible to acquire the outer shape and identification information of a workpiece simply by switching the lighting for the camera. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram showing a schematic diagram of a workpiece imaging system according to an embodiment of the present invention; [Diagram 2]13 is a view of the holding plate in the holding section of the transport section as viewed from the workpiece adsorption surface side. FIG. [Diagram 3] 11A and 11B are diagrams illustrating the relationship between the holding plate and the size of the workpiece. [Figure 4] FIG. 2 is a perspective view illustrating a light absorption process of each part of the housing. [Diagram 5] 13(a) and (b) are diagrams illustrating illumination when capturing an image of an identification mark on a workpiece. [Figure 6] 1A, 1B, 1C and 1D are diagrams illustrating an imaging process performed by a work imaging system according to an embodiment of the present invention. [Figure 7] 13A and 13B are diagrams illustrating contrast when imaging in workpiece alignment. [Figure 8] 1A, 1B, and 1C are diagrams showing a comparative example of the present embodiment. [Figure 9] 13(a) to 13(d) are diagrams illustrating the effect of diffused light in imaging an identification mark. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The embodiment described below is an example of a specific embodiment of the present invention. Therefore, the configuration of the embodiment described below should be appropriately modified or changed depending on the configuration of the device to which the present invention is applied and various conditions, and the present invention is not limited to the following embodiment.

[0016] FIG. 1 is a diagram illustrating a workpiece imaging system according to an embodiment of the present invention.

[0017] The workpiece imaging system 100 of this embodiment is configured to include a housing 101, the details of which will be described later in Fig. 4. The housing 101 generally includes a top plate 101a located at the top of the housing 101, side plates 101b covering two side surfaces at the top of the housing 101, four pillars 101c holding the side plates 101b, and a horizontal frame 101d supporting a transparent plate 102. The transparent plate 102 is attached to the lower end of the range in which the side surfaces are covered by the side plates 101b, and an anti-reflection plate 103 is attached to the bottom of the housing 101.

[0018] The workpiece imaging system 100 of this embodiment includes an imaging unit 104, two first irradiation units 105a and 105b, and one second irradiation unit 106. Here, in FIG. 1, the side where the top plate 101a is located is called the upper side, the side where the imaging unit 104 is located is called the lower side, the side where the first irradiation unit 105a is located is called the left side, and the side where the first irradiation unit 105b is located is called the right side, and the same applies in the following description referring to FIG. 1. The top plate 101a, the transparent plate 102, and the anti-reflection plate 103 are substantially the same rectangular shape. The outer shape of the housing 101 is a rectangular parallelepiped. The transparent plate 102 is a transparent plate for sandwiching the conveying unit 108 and the workpiece 107 to be imaged, and can be formed of, for example, glass. The anti-reflection plate 103 is located between the light receiving surface of the imaging unit 104 and the workpiece 107, and an opening is provided on the optical axis of the imaging unit 104. This prevents reflection of equipment parts and the like on the transparent plate, which provides the effect of realizing clearer binarization. The anti-reflection plate 103 is a plate with at least its upper side colored in a color that has a high light absorption rate (e.g., black). This makes it possible to reduce unnecessary reflection of light in the space in which the workpiece, lighting, and light receiving section of the imaging unit of the housing 101 are present. Note that part of the pillars 101c that hold the side plates 101b and part of the horizontal frame 101d are not shown in FIG. 1.

[0019] The first irradiation units 105a and 105b are attached to the center of each of the left and right sides of the housing 101 between the transparent plate 102 and the anti-reflection plate 103 via a support member (not shown). The second irradiation unit 106 is attached to a horizontal frame 101d located on the right side of the housing immediately below the top plate 101a. The second irradiation unit 106 is attached to the center of the horizontal frame 101d extending in the vertical direction of the paper surface in FIG. 1 via a support member (not shown). The imaging unit 104 is attached to the housing 101 via a support member (not shown) so that its light receiving unit can be seen at the center of the anti-reflection plate 103. Illumination from each of the first irradiation units 105a and 105b and the second irradiation unit 106 is selectively switched by a control unit (not shown) that selects the first irradiation units 105a and 105b and the second irradiation unit 106. In this specification, the functional part of the control unit that performs this selection process is called a selection unit.

[0020] The workpiece 107, which is the imaging target of this embodiment, is provided with an identification mark having information unique to the workpiece, such as information for distinguishing the workpiece 107 (hereinafter, identification information), on a part of the workpiece. The workpiece 107 is formed of a resin sheet having a rectangular shape and transmitting a certain amount of light. Regarding this light transmission, at least the periphery around the identification mark needs to be transparent. In this embodiment, since the workpieces 107 having different dimensions are the imaging targets, the workpiece imaging system 100 can acquire the external shape and read the identification mark, which will be described later, corresponding to each of the workpieces 107 having different dimensions. Note that the workpiece is not limited to being made of resin, but may be made of glass, for example, and the imaging target may be, for example, a display panel, or a liquid crystal panel described in Patent Document 1. The shape of the workpiece is not limited to the rectangle of this embodiment, and may be any shape, such as a circle. In this way, any imaging target may be used as long as the workpiece imaging system of the present invention can be applied to acquire the external shape and read the identification mark.

[0021] The identification mark provided on the workpiece 107 may be any mark capable of acquiring the identification information of the identification mark by being imaged by the imaging unit 104. For example, the identification mark may be a circuit itself formed on the workpiece, a mask pattern for forming a circuit, or the like. Alternatively, a barcode, a QR code (registered trademark), or the like may be used as the identification mark.

[0022] The workpiece imaging system 100 of this embodiment includes a conveying unit 108. The conveying unit 108 includes a robot arm 108a and a holding unit 108b. The holding unit 108b adsorbs and holds the workpiece 107 via a holding surface below the holding unit 108b. The robot arm 108a has a shape bent at a right angle, for example, like an L-shape, and has a part (not shown) extending to the other side in the vertical direction of the paper in FIG. 1, and the holding unit 108b that holds the workpiece 107 is attached to the tip of the extended part. The workpiece is held by the holding unit 108b of the conveying unit in the imaging area, and the workpiece 107 can be imaged. This allows the robot arm 108a to insert the held workpiece 107 into the internal space of the housing 101 from the front side of the paper in FIG. 1. The robot arm 108a transports the workpiece 107 placed at a predetermined position while being held by the holder 108b, enters the internal space of the housing 101 from the front side in the vertical direction of the paper surface in FIG. 1, and sets it above the transparent plate 102. Then, the robot arm 108a maintains the state of holding the workpiece 107 while the workpiece imaging system 100 is imaging it. The transparent plate 102 transmits the first irradiation light and the second irradiation light, and is provided in the internal space so that the workpiece 107 comes into contact with the transparent plate 102 as the workpiece 107 moves toward the imaging unit 104. This reduces the warping of the workpiece 107 that comes into contact with the transparent plate 102, and has the effect of making it possible to prevent the workpiece 107 from warping.

[0023] FIG. 2 is a view of the holding plate 302 in the holding unit 108b of the transport unit 108 as seen from the workpiece adsorption surface side. The holding plate 302 is a rectangular plate located on the lower surface side of the holding unit 108b and formed with multiple notches. The holding plate 302 is formed of a light-absorbing material. On the other hand, since the workpiece 107 has translucency, the contrast between the holding plate 302 and the workpiece 107 can be increased. It is needless to say that the holding plate 302 is not limited to being formed of a light-absorbing material. At least the surface side of the holding plate 302 that adsorbs the workpiece 107 may be colored with a light-absorbing color such as matte black. The holding plate 302 is provided with multiple holes (not shown) for suction. In addition, the holding plate 302 is provided with an opening 302a, which is a notch, as a part of its outer shape. Through this opening 302a, light from the upper second irradiating unit 106 can be irradiated onto the workpiece 107 in the imaging of the identification mark described later, and thus the transmitted light of the identification mark can be formed. Since the light transmitting portion of the holding portion 108b is an opening, light can be transmitted through the opening of the holding portion 108b, and the identification mark can be recognized.

[0024] The color of the holding surface of the holding portion 108b is the same as that of the side plates 101b and top plate 101a of the housing 101, and this color creates a contrast with the workpiece, so that the contrast between the color of the holding surface, the colors of the side plates 101b and top plate 101a of the housing, and the workpiece 107 can be increased, which has the effect of improving the visibility of the outline of the workpiece 107. The side plates 101b and top plate 101a of the housing 101 reflect light of a predetermined wavelength and absorb light of the remaining wavelengths, so that the reflected light of the predetermined wavelength from the side plates 101b and top plate 101a of the housing enters the eye, which has the effect of improving the visibility of the outline of the workpiece 107.

[0025] FIG. 3 is a diagram for explaining the relationship between the holding plate 302 shown in FIG. 2 and the size of the workpiece 107. As described above, the workpiece imaging system 100 of this embodiment is compatible with workpieces of different sizes. For this reason, the arrangement of the suction holes (not shown) of the holding plate 302 is determined so as to appropriately suction each of the relatively large size workpiece 107a, the medium size workpiece 107b, and the relatively small size workpiece 107c. In addition, the opening size of the opening 302a is determined so that the identification mark of the workpiece 107 can be appropriately irradiated. In addition, by using the holding plate 302 having the configuration shown in FIG. 3, the matte black color absorbs reflected light from the suction piping of the conveying unit 108, and the like, so that it is possible to prevent the suction piping of the conveying unit 108 from being reflected in the captured image. Furthermore, because the shape of the holding plate 302 brings the holding plate 302 and the upper surface of the transparent plate 102 into contact with each other, it is also possible to hold the workpiece 107 and correct the warp.

[0026] 1 again, the first irradiating units 105a and 105b irradiate the workpiece 107 with the first irradiation light through the transparent plate 102 from below on the same side as the surface where the holding plate 302 of the holding unit 108b holds the workpiece 107. At this time, the first irradiation light is irradiated to an area wider than the workpiece 107 by the two irradiating units.

[0027] On the other hand, the second irradiating unit 106 irradiates the workpiece 107 from an obliquely upward direction opposite to the surface where the holding plate 302 of the holding unit 108b holds the workpiece 107. At this time, the part of the workpiece 107 on which the identification mark is provided is irradiated through the opening 302a of the holding plate 302 as described above.

[0028] The switching of irradiation between the first irradiation units 105a, 105b and the second irradiation unit 106 is performed by a selection unit (not shown). The selection unit can be in the form of a microcomputer having a CPU or the like, and executes a series of processes described later in FIG. 6 according to a predetermined program. Note that the switching of irradiation between the first irradiation units 105a, 105b and the second irradiation unit 106 is not limited to the switching form of turning on the first irradiation units 105a, 105b and turning off the second irradiation unit 106. For example, the irradiation units can be selectively switched by providing a mechanism that physically blocks irradiation from an irradiation unit that is turned off while keeping both the first irradiation units 105a, 105b and the second irradiation unit 106 on, and controlling the blocking operation of the mechanism that physically blocks.

[0029] The imaging unit 104 can be configured with a digital camera. Although the workpiece imaging system of this embodiment uses a single imaging unit, the present invention is not limited to this form. There may be a plurality of imaging units below the transparent plate 102 of the housing 101, and the images captured by the plurality of imaging units may be analyzed to detect the outer shape and identification mark of the workpiece 107.

[0030] FIG. 4 is a perspective view illustrating the light absorption treatment of each part of the housing 101 shown in FIG. 1. As shown in FIG. 4, the periphery of each of the top plate 101a and the transparent plate 102 is held by a horizontal frame 101d supported by four pillars 101c. The top plate 101a and the left and right side plates 101b of the housing 101 are formed of a light absorbing material colored in matte black. As a result, as described later, the contrast between the workpiece and the background can be increased during imaging. In addition, the light absorption treatment by forming the matte black can prevent the reflected light of the equipment, such as a robot arm, from being reflected in the captured image. In this embodiment, the light absorption treatment of the top plate 101a and the left and right side plates 101b is performed on both sides of each plate, but is not limited to this form. It is sufficient that the above-mentioned light absorption treatment is performed at least in the internal space of the housing 101, that is, on the side where imaging is performed using the irradiation light from the irradiation unit of each plate member. In addition, the color of the light absorption treatment does not need to be the same for the top plate 101a and the left and right side plates 101b, and may be different colors. The point is that it is sufficient to increase the contrast with the workpiece 107 and obtain an appropriate image.

[0031] 6(a) and (b) are diagrams for explaining illumination when imaging the identification mark of the workpiece. As described above, the light from the second irradiation unit 106 is irradiated to the location where the identification mark of the workpiece 107 is provided through the opening 302a of the holding plate 302. At this time, a part of the light from the second irradiation unit 106 hits the air suction tube 109 and is reflected, and another part passes through the air suction tube 109 and the diffusion plate 110, and is irradiated to the identification mark of the workpiece 107 as diffused light. The diffusion plate 110 is a component part of the conveying unit 108. In this embodiment, the diffusion plate 110 is formed of frosted glass. By using the diffused light by the diffusion plate 110 in this way, the imaging of the identification mark can be stabilized.

[0032] 6(a) to 6(d) are diagrams for explaining imaging processing by the workpiece imaging system 100 according to one embodiment of the present invention. In this embodiment, imaging is used to perform processing for acquiring an identification mark of the workpiece 107 and processing for acquiring the outer shape of the workpiece 107 and acquiring the position of the workpiece 107 relative to the holder 108b (hereinafter also referred to as "alignment").

[0033] First, as shown in Fig. 5(a), the workpiece 107 placed at a predetermined position is sucked and held by the holding part 108b of the transport part 108. This suction is performed by applying negative pressure by air suction to the workpiece 107 through a plurality of holes provided in the holding plate 302 of the holding part 108b. The transport part 108 is provided with a tube connected to a negative pressure drive source (not shown) for this purpose.

[0034] Next, as shown in Fig. 6(b), the robot arm 108a of the transport unit 108 is operated to insert the workpiece 107 into the internal space of the housing 101 from the front side in the vertical direction of the paper surface of Fig. 6, and the workpiece 107 held by suction is placed so as to be in contact with the transparent plate 102. Alternatively, the workpiece 107 may be placed above the transparent plate 102. At this time, the robot arm 108a is operated so that the holding plate 302 presses the workpiece 107 with a predetermined force. This makes it possible to flatten the workpiece 107 and make it suitable for imaging.

[0035] In a state where the workpiece 107 is held by the holding part 108b of the conveying part 108 and kept flat on the transparent plate 102, as shown in FIG. 6(c), the irradiation from the first irradiation parts 105a and 105b is turned on. At this time, the irradiation from the second irradiation part 106 is turned off. As a result, the irradiation light from the first irradiation parts 105a and 105b irradiates the workpiece 107 from the underside of the transparent plate 102 through the transparent plate 102. Then, the reflected light from the workpiece 107 due to this irradiation enters the light receiving part of the imaging part 104, and the workpiece 107 is imaged. At this time, in this embodiment, as described later in FIG. 7, reflection from the periphery of the workpiece 107 is reduced, and a high-contrast outline image of the workpiece 107 can be acquired.

[0036] Next, the irradiation from the first irradiation units 105a and 105b is turned off, and the irradiation from the second irradiation unit 106 is turned on, as shown in FIG. 6(d). As a result, the light from the second irradiation unit 106 is irradiated from the upper side of the transparent plate 102 to the holding unit 108b that holds the workpiece 107. Then, this irradiated light irradiates the workpiece 107 through the opening 302a of the holding plate 302. An identification mark is provided at a portion of the workpiece 107 corresponding to the opening 302a, and the light that is irradiated to the identification mark and is blocked or attenuated at the identification mark and its vicinity passes through the workpiece 107 and the transparent plate 102, and enters the light receiving unit of the imaging unit 104. Here, the identification mark is of a form that allows information represented by the identification mark to be obtained when the identification mark is imaged by the light that passes through it. As a result, an image of the identification mark of the workpiece 107 is imaged, and the information is obtained. At this time, in this embodiment, as shown in Fig. 5, the light from the second irradiation unit 106 is incident on the workpiece 107 as indirect light that is diffused by peripheral equipment such as the air suction tube of the transport unit described above. This makes it possible to stabilize the imaging of the identification mark. In this way, by imaging the identification mark using transmitted light, it becomes possible to properly image the identification mark regardless of whether the front or back side of the workpiece is placed on the transparent plate 102.

[0037] The coordinates of the workpiece are calculated and the workpiece is identified by image processing of the outline of the workpiece 107 and the identification mark of the workpiece 107 captured as described above. The results of these processes are subjected to processing according to the respective purposes.

[0038] The workpiece imaging system 100 of this embodiment is provided with a calculation unit (not shown) that calculates the shape, area, or alignment coordinates of the workpiece 107 from the outer shape of the workpiece 107 imaged by the imaging unit 104, and identifies the workpiece 107 from the identification information of the workpiece 107. Such functions of the calculation unit make it possible to perform various processes or preparations for these processes that correspond to the type of workpiece and to the unique state of each workpiece.

[0039] As described above, by simply switching between the first irradiation unit and the second irradiation unit, it is possible to acquire the outer shape and the identification mark of the workpiece 107. In other words, it is not necessary to prepare imaging units corresponding to each of the outer shape and the identification mark of the workpiece 107, and as a result, a complex configuration such as moving the workpiece 107 for imaging and preparing lighting according to the movement is not required.

[0040] It is needless to say that the workpiece alignment and the process of detecting the identification mark may be performed in the reverse order from that described above. Also, the alignment and the process of detecting the identification mark may be performed at different times, rather than as part of a series of steps.

[0041] 7(a) and 7(b) are diagrams for explaining contrast during imaging in the alignment of the workpiece described in FIG. 6. The workpiece imaging system of this embodiment is applicable to workpieces of various sizes. FIG. 7(a) shows the imaging result of the alignment of a relatively small workpiece 107c. FIG. 7(b) shows the imaging result of the alignment of a relatively large workpiece 107a.

[0042] As shown in these figures, this embodiment increases the contrast between the workpiece and its surroundings by reducing the light reflected from the surroundings of the workpiece 107. Specifically, as described above, the holding plate 302, top plate 101a, and side plate 101b of the transport unit 108 are colored matte black to reduce the light reflected from the surroundings of the workpiece.

[0043] 8(a), (b) and (c) are diagrams showing comparative examples of the present embodiment shown in FIG. 7. FIG. 8(a) and (b) show the imaging results of workpieces of the same size as the workpieces shown in FIG. 7(a) and (b), respectively. The comparative examples show a case where no color is applied to reduce reflected light from the surroundings of the workpiece, as in the present embodiment. As shown in FIG. 8, in the case of the comparative example, the contrast is small, making it relatively difficult to obtain the workpiece outline by image processing.

[0044] 8(c) shows, as another comparative example, an imaging result in the case where the holding plate 302, the top plate, and the side plates are not present. As shown in the figure, the holding part of the conveying part and the like are reflected in the captured image, which makes the obtained image unstable and makes it difficult to properly obtain the outer shape of the workpiece by image processing.

[0045] 9(a) to (d) are diagrams illustrating the effect of diffused light in imaging an identification mark. Figures 9(a) and (c) show the case where diffused light is not used, and Figures 9(b) and (d) show the case where diffused light is used.

[0046] When diffused light is not used, a clear image 901a of the workpiece 107 cannot be obtained as shown in Fig. 9(c). In contrast, when diffused light is used, a clear image of the identification mark 901b in the captured image 901a can be obtained as shown in Fig. 9(d).

[0047] According to this embodiment, diffused light can be formed using components of the transport unit 108, for example, equipment components such as the tube 109, and this makes it possible to perform stable imaging using appropriate indirect light in a limited space. In addition, there is no need to provide a new diffuser plate, and no space is required for a new diffuser plate.

[0048] (Embodiments of the invention) A first embodiment of the present invention is a workpiece imaging system comprising: a holding unit that holds a workpiece in contact with a holding surface in an imaging area; a first irradiation unit that irradiates a first irradiation light from a direction opposite the holding surface that holds the workpiece toward a surface of the workpiece, over a wider area than the workpiece; a second irradiation unit that irradiates a second irradiation light from the back side of the workpiece toward an identification location of the workpiece through a light transmitting unit of the holding unit; a selection unit that irradiates light toward the workpiece from either the first irradiation unit or the second irradiation unit; and an imaging unit that is disposed opposite the workpiece, receives the first irradiation light reflected by the workpiece to image the outline of the workpiece, and receives the second irradiation light that has passed through the work to image the identification information of the workpiece.

[0049] This has the effect of making it possible for the workpiece imaging system to acquire the outer shape and identification information of the workpiece simply by switching the lighting for the camera.

[0050] A second embodiment of the present invention is the same as the first embodiment, further comprising a transport section that causes the holding section to hold the substrate in the imaging area.

[0051] This has the effect of making it possible to hold the workpiece by the holding portion of the transport section in the imaging area and to image the workpiece.

[0052] A third embodiment of the present invention is a housing that defines the imaging area in an internal space in the second embodiment, and further includes a housing including a top panel and side panels, and the color of the holding surface is the same as the color of the side panels and top panel of the housing, and is a color that creates a contrast with the workpiece.

[0053] This increases the contrast between the color of the holding surface, the colors of the side panels and the top panel of the housing, and the workpiece, thereby improving the visibility of the outline of the workpiece.

[0054] A fourth embodiment of the present invention is the same as the third embodiment, in that the side plates and the top plate of the housing reflect light of a predetermined wavelength and absorb light of the remaining wavelengths.

[0055] This allows light of a specified wavelength to be reflected by the side panels and top panel of the housing and enters the eye, improving the visibility of the outline of the workpiece.

[0056] A fifth embodiment of the present invention is the second or fourth embodiment, in which the second irradiation section irradiates the second irradiation light to the identification location through a diffusion plate installed in the transport section.

[0057] This has the effect of enabling stable imaging of the identification mark using indirect light without the need for installing any new fixtures.

[0058] A sixth embodiment of the present invention is the fifth embodiment, in which the diffusion plate is a component part of the transport section.

[0059] This makes it possible to form diffuse light, and has the effect of enabling stable imaging using appropriate indirect light in a limited space.

[0060] A seventh embodiment of the present invention is any of the first to sixth embodiments, in which the light transmitting portion of the holding portion is an opening.

[0061] This allows light to pass through the opening in the holding portion, which has the effect of making it possible to recognize the identification mark.

[0062] An eighth embodiment of the present invention is characterized in that, in the first to seventh embodiments, an anti-reflection plate is provided which is positioned between the light receiving surface of the imaging unit and the workpiece and has an opening on the optical axis of the imaging unit.

[0063] This has the effect of preventing reflections of equipment parts and the like on the transparent plate, thereby achieving clearer binarization.

[0064] A ninth embodiment of the present invention is characterized in that, in the first to eighth embodiments, a calculation unit is provided which calculates the shape, area, or alignment coordinates of the work from the outer shape of the work imaged by the imaging unit, and identifies the work from the identification information of the work.

[0065] This has the effect of allowing the calculation unit to calculate the shape, area, or alignment coordinates of the workpiece, thereby identifying the workpiece from the workpiece identification information.

[0066] A tenth embodiment of the present invention is characterized in that, in the first to ninth embodiment, a transparent plate is provided in the internal space which transmits the first irradiation light and the second irradiation light and against which the workpiece abuts as the workpiece moves toward the imaging unit.

[0067] This reduces warping of the workpiece that comes into contact with the transparent plate, making it possible to prevent warping of the workpiece. [Explanation of symbols]

[0068] 100 Work Imaging System 101 Cabinet 101a Tabletop 101b Side plate 101c pillar 101d horizontal frame 102 Transparent plate 103 Anti-reflection plate 104 Imaging unit 105a 1st irradiation section 105b 1st irradiation section 106 Second irradiation section 107 Work 107a Large size workpiece 107b Medium size workpiece 107c Small size work 108 Conveyor 108a Robot Arm 108b Holding part 109 Tube 110 Diffuser 302 Holding plate 302a aperture 901a Image 901b Identification mark

Claims

1. a holding portion that holds the workpiece in contact with a holding surface in the imaging area; A first irradiation unit that irradiates a first irradiation light from a direction facing the holding surface that holds the workpiece toward a surface of the workpiece to a range wider than the workpiece; A second irradiation unit that irradiates a second irradiation light from a back side of the workpiece toward an identification portion of the workpiece through a light transmitting portion of the holding unit; A selection unit that irradiates light from either the first irradiation unit or the second irradiation unit toward the workpiece; an imaging unit disposed opposite the workpiece, receiving the first irradiation light reflected by the workpiece to image the outer shape of the workpiece, and receiving the second irradiation light transmitted through the workpiece to image identification information of the workpiece.

2. The workpiece imaging system according to claim 1 , further comprising a transport section that transports the workpiece to the imaging area and causes the workpiece to be held by the holding section in the imaging area.

3. The workpiece imaging system of claim 2, further comprising a housing that defines the imaging area in an internal space, the housing including a top plate and side plates, the color of the holding surface being the same as the color of the side plates and the top plate of the housing, and a color that creates a contrast with the workpiece.

4. 4. The workpiece imaging system according to claim 3, wherein the holding surface of the transport section and the side and top panels of the housing reflect light of a predetermined wavelength and absorb light of the remaining wavelengths.

5. The workpiece imaging system according to claim 2 or 4, wherein the second irradiation unit irradiates the second irradiation light onto the identification location via a diffusion plate provided in the transport unit.

6. The workpiece imaging system according to claim 5 , wherein the diffusion plate is a component part of the transport unit.

7. The workpiece imaging system according to claim 1 , wherein the light transmitting portion of the holding portion having the holding surface is an opening.

8. The workpiece imaging system according to claim 1 , further comprising an anti-reflection plate located between the light receiving surface of the imaging unit and the workpiece, the anti-reflection plate having an opening on an optical axis of the imaging unit.

9. The workpiece imaging system according to any one of claims 1 to 8, further comprising a calculation unit that calculates the shape, area, or alignment coordinates of the workpiece from the outer shape of the workpiece imaged by the imaging unit, and identifies the workpiece from the identification information of the workpiece.

10. A workpiece imaging system as described in any one of claims 1 to 9, comprising a transparent plate in the imaging area that transmits the first irradiation light and the second irradiation light and against which the workpiece abuts as the workpiece moves toward the imaging unit.

Images