Lighting device

Abstract

This lighting device comprises: a support body that has a workpiece passage through which a long workpiece passes, the workpiece passage being formed so as to penetrate in a first direction along a central axis; and a plurality of light-emitting units that are installed side by side in the circumferential direction centered on the central axis with respect to the support body so as to surround the workpiece passage when viewed in the first direction. Each of the plurality of light-emitting units is disposed such that emitted light crosses the central axis.

Description

Illumination device

[0001] This disclosure relates to an illumination device.

[0002] This application claims priority based on Japanese Application No. 2024-211081 filed on December 4, 2024, and incorporates all the descriptions set forth in the said Japanese application.

[0003] Patent Document 1 describes an appearance inspection device equipped with an illumination device for imaging the outer peripheral surface of a long rubber hose using a camera.

[0004] Japanese Patent Application Laid-Open No. 2008-26254

[0005] The illumination device according to this disclosure includes a support having a work passage formed to penetrate in a first direction along a central axis through which a long work is passed, and a plurality of light emitting parts arranged side by side in a circumferential direction centered on the central axis with respect to the support so as to surround the work passage when viewed in the first direction. Each of the plurality of light emitting parts is arranged such that the emitted light intersects the central axis.

[0006] FIG. 1 is a schematic front view of a photographing system including the illumination device according to the embodiment. FIG. 2 is a schematic front view of the illumination device according to the embodiment. FIG. 3 is a schematic cross-sectional view taken along line A - A of FIG. 2. FIG. 4 is a schematic cross-sectional view taken along line B - B of FIG. 2. FIG. 5 is a schematic diagram showing the relationship between the central axis and the optical axes of each light emitting element in the illumination device according to the embodiment. FIG. 6 is a schematic developed view of the illumination area of the light emitting part on a plane in the illumination device according to the embodiment. FIG. 7 is a schematic cross-sectional view showing the illumination area in a cross-section corresponding to the virtual plane K1 of FIG. 6.

[0007] In a conventional appearance inspection device, two illumination devices are arranged facing each other at symmetric positions with respect to the rubber hose. For this reason, on the outer peripheral surface of the rubber hose, there are areas where light is likely to hit and areas where it is difficult to hit, and a partially dark area may occur.

[0008] Therefore, one of the objectives of this disclosure is to provide an illumination device that can reduce the occurrence of partially dark areas on the outer surface of a workpiece when light is emitted toward the workpiece.

[0009] According to this disclosure, it is possible to provide a lighting device that can reduce the occurrence of partially dark areas on the outer surface of a workpiece when light is emitted toward the workpiece.

[0010] Embodiments of the present disclosure will be listed and described first. (1) An illumination device according to the present disclosure comprises a support having a work passage formed to penetrate in a first direction along a central axis through which a long workpiece passes, and a plurality of light-emitting units arranged in a circumferential direction with respect to the support so as to surround the work passage when viewed in the first direction. Each of the plurality of light-emitting units is arranged such that the light it emits intersects the central axis.

[0011] The lighting device according to this disclosure, when a workpiece is passed through the workpiece passage, emits light from the light-emitting part, and because the light-emitting part is installed to surround the workpiece passage, it can illuminate the entire outer surface of the workpiece. This reduces the occurrence of partially dark areas on the outer surface of the workpiece when light is emitted toward a long workpiece. Here, "outer surface of the workpiece" means the outer surface of the area of ​​the workpiece that is illuminated by the lighting device in the longitudinal direction of the workpiece.

[0012] (2) In (1) above, each of the plurality of light-emitting units has a plurality of light-emitting elements arranged in the radial direction, and the optical axes of the plurality of light-emitting elements in each of the light-emitting units may be non-parallel to each other. The lighting device according to the present disclosure improves the degree of design freedom when setting the orientation of the optical axes of the plurality of light-emitting elements.

[0013] (3) In (2) above, the optical axes of the plurality of light-emitting elements in each of the light-emitting units may intersect with each other. The lighting device according to this disclosure makes it easier to increase the illuminance of the area to be illuminated on the workpiece.

[0014] (4) In any of (1) to (3) above, the plurality of light-emitting units are a plurality of first light-emitting units, and the lighting device further comprises a plurality of second light-emitting units installed on the support, each of the plurality of second light-emitting units being positioned between adjacent first light-emitting units in the circumferential direction, wherein the luminous flux value of the light emitted from each of the plurality of second light-emitting units may be smaller than the luminous flux value of the light emitted from each of the plurality of first light-emitting units. The lighting device according to this disclosure makes it easier to reduce power consumption and improve illuminance to the workpiece while reducing power consumption and heat generation in the entire lighting device compared to simply increasing the number of first light-emitting units.

[0015] (5) In (4) above, the first light-emitting unit and the second light-emitting unit may be installed such that the distance between adjacent first and second light-emitting units is equal in the circumferential direction. According to the lighting device in accordance with this disclosure, the unevenness in the illuminance of the target area of ​​the workpiece when supplemented by light emitted from the second light-emitting unit can be reduced.

[0016] (6) In any of (1) to (5) above, the support may further include an inner circumferential surface surrounding the work passage, an outer circumferential surface formed at a position where the minimum distance from the central axis is longer than the maximum distance between the central axis and the plurality of light-emitting parts, and a through-path that penetrates in the first direction and is formed from the inner circumferential surface to the outer circumferential surface. The through-path may be formed between at least one pair of adjacent light-emitting parts among the plurality of light-emitting parts. According to the lighting device in accordance with the present disclosure, a through-path can be formed while maintaining the spacing between the plurality of light-emitting parts. This makes it possible to have a structure in which a long workpiece can be placed in the work passage through the through-path while maintaining a structure that reduces the occurrence of partially dark areas in the circumferential direction of the workpiece.

[0017] (7) In (4) or (5) above, the support may have an inner circumferential surface surrounding the work passage, an outer circumferential surface formed at a position where the minimum distance from the central axis is longer than the maximum distance between the central axis and the plurality of light-emitting parts, and a through path that penetrates in the first direction and is formed from the inner circumferential surface to the outer circumferential surface. The through path may be formed to pass between at least one pair of the first light-emitting parts and the second light-emitting parts among the plurality of first light-emitting parts and the second light-emitting parts. According to the lighting device in accordance with the present disclosure, the through path can be formed while arranging the first light-emitting parts and the second light-emitting parts in appropriate positions.

[0018] (8) In (7) above, when viewed along the central axis, the passage is defined by a pair of inner surfaces inclined with respect to a straight line passing through the intersection of the passage and the outer surface and the central axis, and the pair of inner surfaces may be arranged between the first light-emitting part and the second light-emitting part. The lighting device according to this disclosure reduces the risk of a workpiece located in the work passage falling off the support through the passage.

[0019] (9) In (1) above, the plurality of light-emitting units may be a plurality of first light-emitting units, and the lighting device may further comprise a plurality of second light-emitting units installed on the support, each of the plurality of second light-emitting units being positioned between adjacent first light-emitting units in the circumferential direction. Each of the plurality of first light-emitting units may have at least one light-emitting element, and each of the plurality of second light-emitting units may have at least one light-emitting element. The maximum luminous intensity of each light-emitting element in each first light-emitting unit and the maximum luminous intensity of each light-emitting element in each second light-emitting unit may be different from each other. According to the lighting device in this disclosure, illumination of a workpiece can be performed by two types of light-emitting units with different maximum luminous intensities. Since the workpiece can be illuminated using a light-emitting unit with a high maximum luminous intensity as the main light source and a light-emitting unit with a low maximum luminous intensity as the auxiliary light source, power consumption can be reduced, and the occurrence of partially dark areas in the area of ​​illumination on the workpiece can be reduced.

[0020] (10) In (9) above, the maximum luminous intensity of each of the light-emitting elements in each of the second light-emitting units may be greater than the maximum luminous intensity of each of the light-emitting elements in each of the first light-emitting units. According to the illumination device of this disclosure, even if the workpiece is shifted radially from the central axis, the loss of illuminance in the area of ​​illumination on the workpiece can be reduced.

[0021] Next, embodiments of the lighting device 1 according to this disclosure will be described below with reference to the drawings. In the following drawings, the same or corresponding parts will be given the same reference numeral, and their descriptions will not be repeated.

[0022] Figure 1 is a schematic front view illustrating a system including the lighting device 1 according to this embodiment (hereinafter sometimes referred to as the imaging system 10). Figure 2 is a schematic front view illustrating the lighting device 1. Figure 3 is a schematic cross-sectional view illustrating a cross section along the line A-A in Figure 2. Figure 4 is a schematic cross-sectional view illustrating a cross section along the line B-B in Figure 2. Referring to Figures 1 and 3, when facing the front of the lighting device 1, the direction from back to front (the direction from back to front on the plane of Figure 1) is defined as the "first direction D1". The direction opposite to the first direction D1 is defined as the "second direction D2". On a plane perpendicular to the first direction D1, when viewing the lighting device 1 in the second direction D2, the direction from left to right is defined as the "third direction D3". The direction opposite to the third direction D3 is defined as the "fourth direction D4". On a plane perpendicular to the first direction D1, the direction from bottom to top is defined as the "fifth direction D5". The direction opposite to the fifth direction D5 is defined as the "sixth direction D6". Of the two opposing directions on an arc centered on the central axis C1, with the central axis viewed as the second direction D2, the clockwise (right-hand) direction is defined as the "first circumferential direction R1", and the counterclockwise (left-hand) direction is defined as the "second circumferential direction R2". In this disclosure, when simply referred to as "circumferential direction", it means the "first circumferential direction R1". In this disclosure, ordinal numbers preceding terms such as "first direction D1", "second direction D2", "third direction D3", "fourth direction D4", "fifth direction D5", "sixth direction D6", "first circumferential direction R1", and "second circumferential direction R2" are merely markers to distinguish terms and do not indicate priority.

[0023] In this embodiment, the plane including the first direction D1, the second direction D2, the third direction D3, and the fourth direction D4 is defined as the horizontal plane, and the installation surface of the lighting device 1 is described as a surface parallel to the horizontal plane. However, the installation surface may be inclined with respect to the horizontal plane. In this disclosure, "parallel" includes not only cases where two lines, edges, or surfaces, when extended, do not intersect each other, but also cases where they intersect but the angle between them is within a range of 3 degrees or less. "Orthogonal" includes not only cases where two lines, edges, or surfaces, when extended, intersect each other at a 90-degree angle, but also cases where they intersect within a range of 90 degrees ± 3 degrees.

[0024] The illumination device 1 is used, for example, in an imaging system 10 for photographing a workpiece W1. Referring to Figure 1, the imaging system 10 comprises an illumination device 1 having a support body 2 and light-emitting units 3 and 4, and a plurality of imaging units 6. The support body 2 has a work passage 23 through which the workpiece W1 passes. With the workpiece W1 passing through the work passage 23, the light-emitting units 3 and 4 emit light, thereby illuminating the workpiece W1.

[0025] The workpiece W1 according to this embodiment is formed in an elongated shape extending along the central axis C1. The shape of the workpiece W1 is such that, in a cross section perpendicular to the central axis C1, it is formed in, for example, a circle, triangle, square, pentagon, or hexagon. The workpiece W1 may remain stationary while passing through the workpiece passage 23, or it may move in a first direction D1 along the central axis C1. The workpiece W1 may rotate about the central axis C1. There are no particular restrictions on the material of the workpiece W1, and examples include synthetic resin, pulp, metal, rubber, cloth, wood, glass, and carbon.

[0026] In this disclosure, "long" means a shape in which the length in the first direction D1 is 10 times or more the longest dimension among the width, height, and diameter in a cross section perpendicular to the first direction D1. In this disclosure, the "longitudinal direction" of the workpiece W1 is the direction from the first end of the workpiece W1 toward the second end opposite to the first end, and is the same direction as the "first direction D1".

[0027] The workpiece W1 is flexible. In this disclosure, a flexible workpiece W1 means a workpiece W1 in which, when both ends in the longitudinal direction of the workpiece W1 are supported by simple support, the portion between the two ends bends due to its own weight. In this disclosure, a flexible workpiece W1 may be a workpiece that undergoes elastic deformation or a workpiece that undergoes plastic deformation when both ends in the longitudinal direction of the workpiece W1 are supported by simple support.

[0028] Examples of workpieces W1 include tubes (rubber tubes, carbon tubes, stainless steel tubes, etc.), ropes (cloth ropes, wire ropes, etc.), metal wires (copper wires, steel wires, etc.), electric wires, communication cables (metal cables, fiber optic cables, etc.), and pipes (steel pipes, titanium pipes, copper pipes, carbon pipes, etc.).

[0029] (Outline of the structure of the lighting device 1) The lighting device 1 according to this embodiment is used to illuminate a long workpiece W1. Referring to Figure 1, the lighting device 1 comprises a support 2 and a plurality of light-emitting units 3 and 4 attached to the support 2. The plurality of light-emitting units 3 and 4 include a plurality of first light-emitting units 3 arranged in a first circumferential direction R1 and a plurality of second light-emitting units 4, each arranged between adjacent first light-emitting units 3. Each first light-emitting unit 3 according to this embodiment has a plurality of light-emitting elements 31 and 32 (two in this embodiment). Each second light-emitting unit 4 according to this embodiment has one light-emitting element 41. The two light-emitting elements in the first light-emitting unit 3 may be referred to as the "first light-emitting element 31" and the "second light-emitting element 32". The light-emitting element in the second light-emitting unit 4 may be referred to as the "third light-emitting element 41".

[0030] The support 2 is supported on the installation surface, for example, by a base. The base is not particularly limited and may be formed by a frame or by a plate. The base may also be a rail from which the support 2 is suspended.

[0031] (Structure of the support 2) Referring to Figure 2, the support 2 supports a plurality of light-emitting units 3 and 4. The support 2 includes a first mounting portion 21 on which the first light-emitting unit 3 is installed, a second mounting portion 22 on which the second light-emitting unit 4 is installed, a work passage 23, and a passage 24. In this embodiment, the support 2 has the first mounting portion 21 and the second mounting portion 22 integrally formed.

[0032] (Work passage 23) A workpiece W1 is passed through the work passage 23. The work passage 23 is formed at a position that includes the center of the support 2 when viewing the lighting device 1 in the second direction D2. Referring to Figure 3, the work passage 23 penetrates the support 2 from the surface facing the space in the second direction D2 from the support 2 (hereinafter referred to as the rear surface 26) to the surface facing the space in the first direction D1 from the support 2 (hereinafter referred to as the front surface 27). In this embodiment, the inner circumferential surface 28 defining the work passage 23 is circular when viewed in the second direction D2, but it may be a polygon such as a square, pentagon, hexagon, or octagon.

[0033] (First mounting portion 21) Referring to Figure 2, the first light-emitting portion 3 is installed on the first mounting portion 21. The multiple first mounting portions 21 are arranged so as to surround the work passage 23 when viewing the lighting device 1 in the second direction D2. The multiple first mounting portions 21 are formed at regular intervals in the first circumferential direction R1. Each first mounting portion 21 has two mounting surfaces 211, 212 on which the light-emitting elements are arranged. Each first mounting portion 21 includes an inner mounting surface 211 and an outer mounting surface 212 as the two mounting surfaces 211, 212. The first light-emitting element 31 is mounted on the inner mounting surface 211. The second light-emitting element 32 is mounted on the outer mounting surface 212. The inner mounting surface 211 and the outer mounting surface 212 are arranged in this order radially when viewing the support 2 in the second direction D2. In this disclosure, "radial direction" means the direction from the central axis C1 to any point on the outer circumferential surface 29 of the support 2 in a cross section perpendicular to the central axis C1. In the radial direction, the outer circumferential surface 29 of the support 2 is located outside the outermost first mounting portion 21. In other words, in the radial direction, the minimum distance between the central axis C1 and the outer circumferential surface 29 of the support 2 is longer than the maximum distance between the central axis C1 and the plurality of light-emitting portions 3 and 4.

[0034] Referring to Figure 3, the internal mounting surface 211 is inclined with respect to a virtual plane perpendicular to the central axis C1. The angle between the internal mounting surface 211 and the virtual plane is the first angle θ1. The inclination of the internal mounting surface 211 with respect to the virtual plane causes the optical axis of the first light-emitting element 31 (hereinafter, the first optical axis OP1) to be inclined with respect to the central axis C1. The rear surface 26 of the support 2 may be flat, or the rear surface 26 may be parallel to the virtual plane. In the support 2 according to this embodiment, the first angle θ1 is synonymous with the angle between the rear surface 26 and the internal mounting surface 211.

[0035] The outer mounting surface 212 is inclined with respect to a virtual plane perpendicular to the central axis. The angle between the outer mounting surface 212 and the virtual plane is the second angle θ2. The second angle θ2 is greater than the first angle θ1. The inclination of the outer mounting surface 212 with respect to the virtual plane causes the optical axis of the second light-emitting element 32 (hereinafter, the second optical axis OP2) to be inclined with respect to the central axis C1. In the support 2 according to this embodiment, the second angle θ2 is synonymous with the angle between the rear surface 26 and the outer mounting surface 212.

[0036] The inner surface 211 and the outer surface 212 are, for example, bottom surfaces included in the inner surface that defines the recess. The shapes of the inner surface 211 and the outer surface 212 are not particularly limited and include, for example, polygonal shapes such as squares and pentagons, and circular shapes. The inner surface 211 and the outer surface 212 do not need to be clearly demarcated from other areas such as recesses, and it is sufficient that there are surfaces on which a light-emitting element can be attached.

[0037] The first optical axis OP1 of the first light-emitting element 31, mounted on the inner mounting surface 211, is perpendicular to the inner mounting surface 211. The second optical axis OP2 of the second light-emitting element 32, mounted on the outer mounting surface 212, is perpendicular to the outer mounting surface 212. When the first light-emitting element 31 is mounted on the inner mounting surface 211 and the second light-emitting element 32 is mounted on the outer mounting surface 212, the first optical axis OP1 and the second optical axis OP2 become non-parallel to each other. The second optical axis OP2 of the second light-emitting element 32 is contained within a plane that includes the first optical axis OP1 and the central axis C1 of the first light-emitting element 31, and within that plane, it is non-parallel to the first optical axis OP1 of the first light-emitting element 31.

[0038] In this embodiment, the first optical axis OP1 and the second optical axis OP2 approach each other as they move away from the light-emitting elements 31 and 32 in a plane containing the first optical axis OP1, the second optical axis OP2, and the central axis C1. The first optical axis OP1 intersects the central axis C1. The second optical axis OP2 intersects the central axis C1. In a plane containing the first optical axis OP1, the second optical axis OP2, and the central axis C1, the first optical axis OP1 and the second optical axis OP2 intersect at intersection point M1.

[0039] The intersection point M1 of the first optical axis OP1 and the second optical axis OP2 may be on the central axis C1 or offset from the central axis C1. On the straight line connecting the intersection point M1 and the center C31 of the first light-emitting element 31, the intersection point of the first optical axis OP1 and the central axis C1 is located between the intersection point M1 and the center C31. On the straight line connecting the intersection point M1 and the center C32 of the second light-emitting element 32, the intersection point of the second optical axis OP2 and the central axis C1 is located between the intersection point M1 and the center C32. Here, the centers C31 and C32 of the light-emitting elements 31 and 32 refer to the centers of the light-emitting regions of the corresponding light-emitting elements 31 and 32. However, the intersection point M1 of the first optical axis OP1 and the second optical axis OP2 may be located between the intersection point of the first optical axis OP1 and the central axis C1 and the center C31, and between the intersection point of the second optical axis OP2 and the central axis C1 and the center C31.

[0040] The first optical axis OP1 and the second optical axis OP2 do not necessarily have to intersect. For example, the first optical axis OP1 may intersect the central axis C1, but the second optical axis OP2 does not have to intersect the central axis C1. For example, the second optical axis OP2 may intersect the central axis C1, but the first optical axis OP1 does not have to intersect the central axis C2. For example, the first optical axis OP1 and optical axis OP2 do not have to intersect the central axis C1.

[0041] (Second Mounting Portion 22) Referring to FIG. 2, the second light-emitting portion 4 is installed in the second mounting portion 22. Each second mounting portion 22 is arranged between adjacent first mounting portions 21 among the plurality of first mounting portions 21 in the first circumferential direction R1. In the first circumferential direction R1, the second mounting portion 22 is formed such that the distance L1 between adjacent first mounting portions 21 and the second mounting portion 22 is equally spaced. Thereby, the first light-emitting portion 3 and the second light-emitting portion 4 are installed on the support 2 such that the distance L1 between the first light-emitting portion 3 and the second light-emitting portion 4 adjacent thereto is equally spaced in the first circumferential direction R1.

[0042] Referring to FIG. 4, the second mounting portion 22 has an arrangement surface 221 to which the third light-emitting element 41 is attached. The arrangement surface 221 is inclined with respect to a virtual plane orthogonal to the central axis. The angle formed between the arrangement surface 221 and the virtual plane is the third angle θ3. The third angle θ3 may be equal to or greater than the first angle θ1 and equal to or less than the second angle θ2, or may be greater than the first angle θ1 and less than the second angle θ2. By inclining the arrangement surface 221 with respect to the virtual plane, the optical axis of the third light-emitting element 41 (hereinafter, the third optical axis OP3) is inclined with respect to the central axis C1. In the support 2 according to the present embodiment, the third angle θ3 is synonymous with the angle between the rear surface 26 and the arrangement surface 221.

[0043] Referring to FIG. 2, in the radial direction, the distance from the central axis C1 to the center of the arrangement surface 221 is the same as the distance from the central axis C1 to the center of the outer arrangement surface 212. The arrangement surface 221 and the outer arrangement surface 212 are located on the same arc centered on the central axis C1. Thereby, the center C32 of the second light-emitting element 32 and the center C41 of the third light-emitting element 41 are arranged so as to be aligned on the same arc. The center C41 of the third light-emitting element 41 means the center of the light-emitting region in the third light-emitting element 41.

[0044] The arrangement surface 221 is, for example, the bottom surface included in the inner surface defining the depression. The shape of the arrangement surface 221 is not particularly limited, and examples thereof include a polygonal shape such as a quadrilateral or a pentagon, and a circular shape. The arrangement surface 221 may not have a region clearly partitioned from other regions such as a depression, as long as there is a surface on which the light-emitting element can be attached.

[0045] Referring to Figure 4, the third optical axis OP3 of the third light-emitting element 41 mounted on the mounting surface 221 is perpendicular to the mounting surface 221. When the third light-emitting element 41 is mounted on the mounting surface 221, the third optical axis OP3 intersects the central axis C1. The third optical axis OP3 does not necessarily have to intersect the central axis C1.

[0046] Figure 5 shows a schematic diagram illustrating the relationship between the central axis C1 and the workpiece W1 and the optical axes OP1, OP2, and OP3 of each light-emitting element 31, 32, and 41. Referring to Figure 5, the intersection point P1 is defined as the point where the first optical axis OP1 intersects with the central axis C1. The intersection point P2 is defined as the point where the second optical axis OP2 intersects with the central axis C1. The intersection point P3 is defined as the point where the third optical axis OP3 intersects with the central axis C1. In the first direction D1, the maximum distance L3 from the rear surface 26 of the support 2 to intersection point P2 is greater than or equal to the maximum distance L2 from the rear surface 26 to intersection point P1. In the first direction D1, the maximum distance L4 from the rear surface 26 to intersection point P3 is greater than or equal to the maximum distance L3. For example, the maximum distance L3 is 80 mm or more and 120 mm or less, and may be set to be 90 mm or more and 100 mm or less. This makes it easier to illuminate the workpiece W1 with the second light-emitting unit 4, even if the workpiece W1 is positioned off-center from the central axis C1.

[0047] Figure 6 is a schematic unfolded view of the illumination area S1 of the first light-emitting unit 3 and the illumination area S2 of the second light-emitting unit 4 on a plane relative to the workpiece W1. Referring to Figure 6, the illumination areas S1 of the first light-emitting units 3 adjacent to each other in the first circumferential direction R1 partially overlap. Therefore, the area of ​​the workpiece W1 illuminated by the illumination area S1 is continuous over the entire circumference of the first circumferential direction R1. Accordingly, with the illumination device 1 according to this embodiment, when the workpiece W1 is illuminated, it is possible to reduce the occurrence of partially dark areas in the circumferential direction of the workpiece W1.

[0048] FIG. 7 is a schematic cross-sectional view schematically showing an illumination area in a virtual plane K1 (FIG. 6) orthogonal to the central axis C1. The virtual plane K1 can be set at a position on the workpiece W1 where a desired illuminance can be obtained. For example, it can be set on the central axis of the angular field of view of the imaging unit 6. Referring to FIG. 7, on the virtual plane K1, the illumination area S2 of the second light emitting unit 4 is located radially outside the illumination area S1 of the first light emitting unit 3. Thus, even if the workpiece W1 is located off the central axis C1, the workpiece W1 can be illuminated by the second light emitting unit 4.

[0049] (Through passage 24) Referring to FIG. 2, the through passage 24 is formed from the inner peripheral surface 28 to the outer peripheral surface 29 of the support 2. The through passage 24 penetrates the support 2 from the rear surface 26 to the front surface 27. With such a configuration, it is easy to pass the long workpiece W1 through the support 2. The workpiece W1 extending in the first direction D1 can move from outside the support 2, through the through passage 24, into the workpiece passage 23.

[0050] The through passage 24 includes a first passage 241 and a second passage 242. The first passage 241 extends in the radial direction. The second passage 242 extends from the end of the first passage 241 to the outer peripheral surface 29. The first passage 214 communicates with the second passage 242. The workpiece passage 23 communicates with the second passage 242.

[0051] At least one of the first passage 241 and the second passage 242 is inclined with respect to the virtual straight line KL1. In the through passage 24 according to the present embodiment, both the first passage 241 and the second passage 242 are inclined with respect to the virtual straight line KL1. The "virtual straight line KL1" here is a straight line passing through the central axis C1 and the intersection point P4 between the through passage 24 and the outer peripheral surface 29 of the support 2 when viewed in the second direction D2. The "intersection point P4 between the through passage 24 and the outer peripheral surface 29" here means the intersection point between the virtual line passing through the center between the pair of inner side surfaces defining the through passage 24 and the outer contour line on the outer peripheral surface 29 when the illumination device 1 is viewed in the second direction D2.

[0052] The passage 24 is formed between a pair of adjacent first light-emitting units 3 among the plurality of first light-emitting units 3. More specifically, the passage 24 is formed between adjacent first light-emitting units 3 and second light-emitting units 4 among the plurality of light-emitting units 3 and 4. With this configuration, the passage 24 can be formed while maintaining a configuration in which the plurality of first light-emitting units 3 and the plurality of second light-emitting units 4 are positioned appropriately in the first circumferential direction R1.

[0053] The through passage 24 has a first passage 241 and a second passage 242 that are at different angles with respect to the virtual straight line KL1, thereby reducing the risk of the workpiece W1 located in the workpiece passage 23 falling out of the support 2 through the through passage 24. However, the through passage 24 may be formed by only one of the first passage 241 and the second passage 242.

[0054] (First light-emitting unit 3, second light-emitting unit 4) The plurality of first light-emitting units 3 are the main light sources in the lighting device 1 according to this embodiment. The first light-emitting units 3 are installed on the first mounting portion 21 of the support 2. When the plurality of first light-emitting units 3 are installed on the first mounting portion 21, they are installed in a circumferential direction. Each first light-emitting unit 3 has a plurality of light-emitting elements 31, 32 as described above. In this embodiment, each first light-emitting unit 3 has two light-emitting elements 31, 32 as a plurality of light-emitting elements, but it may have three or more light-emitting elements. However, each first light-emitting unit 3 may have only one light-emitting element.

[0055] The first light-emitting element 31 is attached to the internal mounting surface 211. Attachment of the first light-emitting element 31 to the internal mounting surface 211 can be done by, for example, adhesive, fitting, screwing, fusion bonding, hooking, or magnetic attachment. The first light-emitting element 31 is an LED (Light Emitting Diode) light-emitting element. The first light-emitting element 31 in this embodiment is a power LED. In this disclosure, a power LED means an LED with an output power of 1W or more.

[0056] The second light-emitting element 32 is attached to the external mounting surface 212. Attachment of the second light-emitting element 32 to the external mounting surface 212 can be done by, for example, adhesive, fitting, screwing, fusion, hooking, or magnetic attachment. The second light-emitting element 32 is an LED light-emitting element. In this embodiment, the second light-emitting element 32 is a power LED.

[0057] The second light-emitting unit 4 is an auxiliary light source in the lighting device 1 according to this embodiment. Even if the workpiece W1 is shifted radially from the central axis C1, the workpiece W1 can be illuminated by the second light-emitting unit 4. Each second light-emitting unit 4 has one third light-emitting element 41. However, each second light-emitting unit 4 may have two or more third light-emitting elements 41. The third light-emitting element 41 is an LED light-emitting element. In this embodiment, the third light-emitting element 41 is a power LED.

[0058] The luminous flux value of the light emitted from each second light-emitting unit 4 is smaller than the luminous flux value of the light emitted from each first light-emitting unit 3. The luminous flux value of the first light-emitting unit 3 is the intensity of the light emitted in any direction when the first light-emitting element 31 and the second light-emitting element 32 are illuminated. The luminous flux values ​​in the first light-emitting unit 3 and the second light-emitting unit 4 can be measured, for example, by an orientation measurement method. Compared to simply increasing the number of units by replacing the second light-emitting unit 4 with the first light-emitting unit 3, the lighting device 1 can reduce power consumption more easily, improve illuminance to the workpiece W1, and reduce power consumption and heat generation in the lighting device 1 as a whole.

[0059] In this embodiment of the lighting device 1, the first light-emitting element 31, the second light-emitting element 32, and the third light-emitting element 41 are all of the same type. Therefore, in this embodiment, the maximum luminous intensity of each of the first light-emitting element 31, the second light-emitting element 32, and the third light-emitting element 41 is the same. Consequently, with the lighting device 1 according to this embodiment, inventory management of the light-emitting elements 31, 32, and 41 becomes easier during manufacturing.

[0060] The maximum luminous intensity of the third light-emitting element 41 may differ from the maximum luminous intensity of each of the first light-emitting elements 31 and the second light-emitting element 32. In particular, the maximum luminous intensity of the third light-emitting element 41 may be greater than the maximum luminous intensity of each of the first light-emitting elements 31 and the second light-emitting element 32. With this configuration, even if the workpiece W1 is shifted radially from the central axis C1, the loss of illuminance in the area of ​​illumination on the workpiece W1 can be reduced.

[0061] (Imaging Unit 6) The imaging unit 6 is positioned so that the area where the light emitted from the multiple light-emitting units 3 and 4 intersects with the central axis C1 falls within the field of view. The central axis (optical axis) of the field of view in the imaging unit 6 intersects with the central axis C1 of the illumination device 1. In this embodiment, the central axis of the field of view in the imaging unit 6 is perpendicular to the central axis C1 of the illumination device 1.

[0062] The imaging unit 6 is a camera. The imaging unit 6 can acquire multiple still images. These still images may be, for example, multiple support images that make up a video, or they may be a dataset representing still images.

[0063] Multiple imaging units 6 are arranged at intervals in the circumferential direction. Multiple imaging units 6 are arranged at equal intervals. In this embodiment, there are three arranged in the circumferential direction, but there may be four or more, or there may be one or two.

[0064] The multiple imaging units 6 are installed so as not to move relative to the lighting device 1. For example, the multiple imaging units 6 are fixed to the mounting surface, and the lighting device 1 according to this embodiment is fixed to the mounting surface. In this way, the multiple imaging units 6 are installed so as not to move relative to the lighting device 1. The imaging units 6 may be directly fixed to the lighting device 1, or they may be supported independently of the lighting device 1 by self-supporting support legs such as a tripod.

[0065] (Modified Version) The support 2 may have a heat dissipation section for dissipating heat generated from the first light-emitting section 3 and the second light-emitting section 4. The heat dissipation section can be formed, for example, on at least one of the outer peripheral surface 29 and the rear surface 26 of the support 2. The heat dissipation section is thermally connected to the light-emitting section. As a result, the heat generated from the light-emitting sections 3 and 4 is dissipated through the support 2 to the heat dissipation section. Examples of the heat dissipation section include a plurality of grooves, a plurality of protrusions, and a plurality of fins. The heat dissipation section may be integrated with the support 2 or it may be a separate part.

[0066] In the above embodiment, power LEDs with an output power of 1W or more were used as light-emitting elements in the first light-emitting section 3 and the second light-emitting section 4, but LEDs with an output power of less than 1W may also be used.

[0067] In the above embodiment, the light-emitting elements of the first light-emitting unit 3 and the second light-emitting unit 4 are mounted so that their optical axes OP1, OP2, and OP3 intersect the central axis C1. However, the optical axes OP1, OP2, and OP3 do not necessarily have to intersect the central axis C1. The light-emitting elements of the first light-emitting unit 3 and the second light-emitting unit 4 may be arranged so that the peripheral light emitted from the light-emitting elements intersects the central axis C1 even if the optical axes OP1, OP2, and OP3 do not intersect the central axis C1.

[0068] The lighting device 1 according to the above embodiment has a first light-emitting unit 3 and a second light-emitting unit 4, but the second light-emitting unit 4 is not required, and the device may consist only of a plurality of first light-emitting units 3.

[0069] In the above embodiment of the lighting device 1, one second light-emitting unit 4 is arranged between adjacent first light-emitting units 3 in the first circumferential direction R1. However, in this disclosure, two or more second light-emitting units 4 may be arranged between adjacent first light-emitting units 3 in the first circumferential direction R1. In this case, the distance between a pair of adjacent second light-emitting units 4 in the first circumferential direction R1 may be the same as the distance L1 between adjacent first light-emitting units 3 and second light-emitting units 4.

[0070] In the above embodiment, the lighting device 1 was described based on a shooting system 10 having an imaging unit 6, but it is also possible to use the lighting device 1 alone, and the imaging unit 6 may be omitted.

[0071] In the lighting device 1 according to the above embodiment, the light-emitting units 3 and 4 may be configured so that the light intensity can be adjusted by the user's operation.

[0072] In the above embodiment, each second light-emitting unit 4 has one light-emitting element 41, but it may have multiple light-emitting elements.

[0073] The support 2 may be maintained such that its rear surface 26 is aligned with a vertical plane or aligned with a horizontal plane.

[0074] It should be understood that at least one configuration or feature described in each embodiment and variation can be combined with other embodiments and variations, or modified in various ways. The embodiments disclosed herein are illustrative in all respects and should be understood not to be restrictive in any way. The scope of the invention is defined by the claims rather than the foregoing description, and all modifications within the meaning and scope of the claims are intended to be included.

[0075] 10 Imaging system, 1 Lighting device, 2 Support, 21 First mounting part, 211 Inner placement surface, 212 Outer placement surface, 22 Second mounting part, 221 Placement surface, 23 Work passage, 24 Through passage, 241 First passage, 242 Second passage, 26 Rear surface, 27 Front surface, 28 Inner circumferential surface, 29 Outer circumferential surface, 3 First light-emitting part, 31 First light-emitting element, 32 Second light-emitting element, 4 Second light-emitting part, 41 Third light-emitting element, 6 Imaging part, W1 Work, C1 Central axis, C31 Center, C32 Center, C41 Center, S1 Illumination area of ​​the first light-emitting part, S2 Illumination area of ​​the second light-emitting part, K1 Virtual plane, KL1 Virtual straight line, D1 First direction, D2 Second direction, D3 Third direction, D4 Fourth direction, D5 Fifth direction, D6 Sixth direction, R1 First circumferential direction, R2 Second circumferential direction, L1 distance, L2 distance, L3 distance, L4 distance, θ1 first angle, θ2 second angle, θ3 third angle, OP1 first optical axis, OP2 second optical axis, OP3 third optical axis, M1 intersection point, P1 point, P2 point, P3 point, P4 intersection point of the passage and the outer surface of the support.

Claims

1. A lighting device comprising: a support having a work passage formed to penetrate in a first direction along a central axis through which a long workpiece passes; and a plurality of light-emitting units arranged in a circumferential direction around the central axis relative to the support so as to surround the work passage when viewed in the first direction, wherein each of the plurality of light-emitting units is arranged so as to emit light that intersects the central axis.

2. The lighting device according to claim 1, wherein each of the plurality of light-emitting units has a plurality of light-emitting elements arranged in the radial direction, and the optical axes of the plurality of light-emitting elements in each of the light-emitting units are non-parallel to each other.

3. The illumination device according to claim 2, wherein the optical axes of the plurality of light-emitting elements in each of the light-emitting sections intersect with each other.

4. The lighting device according to any one of claims 1 to 3, wherein the plurality of light-emitting units are a plurality of first light-emitting units, and the lighting device further comprises a plurality of second light-emitting units installed on the support, each of the plurality of second light-emitting units being positioned between adjacent first light-emitting units in the circumferential direction, and the luminous flux value of the light emitted from each of the plurality of second light-emitting units is smaller than the luminous flux value of the light emitted from each of the plurality of first light-emitting units.

5. The lighting device according to claim 4, wherein the plurality of first light-emitting units and the plurality of second light-emitting units are installed such that the distance between adjacent first light-emitting units and second light-emitting units is equal in the circumferential direction.

6. The lighting device according to any one of claims 1 to 5, wherein the support further comprises an inner circumferential surface surrounding the work passage, an outer circumferential surface formed at a position where the minimum distance from the central axis is longer than the maximum distance between the central axis and the plurality of light-emitting parts, and a through path that penetrates in the first direction and is formed from the inner circumferential surface to the outer circumferential surface, the through path being formed between at least one pair of adjacent light-emitting parts among the plurality of light-emitting parts.

7. The lighting device according to claim 4 or 5, wherein the support has an inner circumferential surface surrounding the work passage, an outer circumferential surface formed at a position where the minimum distance from the central axis is longer than the maximum distance between the central axis and the plurality of light-emitting parts, and a through path that penetrates in the first direction and is formed from the inner circumferential surface to the outer circumferential surface, the through path being formed to pass between at least one pair of the first light-emitting parts and the second light-emitting parts among the plurality of first light-emitting parts and the second light-emitting parts.

8. The lighting device according to claim 7, wherein, when viewed along the central axis, the passage is defined by the intersection of the passage and the outer surface and a pair of inner surfaces inclined with respect to a straight line passing through the central axis, and the pair of inner surfaces are arranged between the first light-emitting part and the second light-emitting part.

9. The lighting device according to claim 1, wherein the plurality of light-emitting units are a plurality of first light-emitting units, and the lighting device further comprises a plurality of second light-emitting units installed on the support, each of the plurality of second light-emitting units being arranged in the circumferential direction between adjacent first light-emitting units among the plurality of first light-emitting units, each of the plurality of first light-emitting units having at least one light-emitting element, and each of the plurality of second light-emitting units having at least one light-emitting element, and the maximum luminous intensity of each of the light-emitting elements in each of the first light-emitting units and the maximum luminous intensity of each of the light-emitting elements in each of the second light-emitting units being different from each other.

10. The lighting device according to claim 9, wherein the maximum luminous intensity of each of the light-emitting elements in each of the second light-emitting units is greater than the maximum luminous intensity of each of the light-emitting elements in each of the first light-emitting units.

Images