JP6545476B2 - Line light irradiator - Google Patents

Description

  The present invention relates to, for example, a line light irradiation apparatus for irradiating line-like light to an object (work) such as a product in a factory or the like, and suitably used for an appearance inspection or the like.

  The line light irradiation apparatus irradiates, for example, a line-shaped light (hereinafter also referred to as line light) along a width direction orthogonal to the conveyance direction to a sheet material or a flat work conveyed in a predetermined direction. In many cases, LEDs arranged in a line along the width direction are used as light sources.

  For example, when detecting a defect such as a flaw along the work transfer direction, the light axis of the LED is inclined at a predetermined angle with respect to a plane perpendicular to the width direction, and the work is irradiated with light from an oblique direction. For example, Patent Document 1 discloses such a line light irradiation apparatus. In this line light irradiation apparatus, an inclined surface corresponding to the inclination angle of the optical axis of the light emitted from the LED (hereinafter also referred to as an LED optical axis) is provided on the base, and the LED is attached to the inclined surface. The optical axis is configured to be inclined.

  By the way, in order to detect the defect along the conveyance direction of the work with high accuracy as described above, the light within the predetermined inclination angle range is detected using the LED with strong directivity (narrow light distribution angle) It is effective to irradiate the work. However, in the case of using a highly directional LED, even a slight deviation of the LED optical axis is likely to cause unevenness in the illuminance of the line light in the predetermined direction, and in order to make this uneven within a predetermined allowable range, at least The tilt angle of each LED optical axis must be precisely aligned with the desired tilt angle.

  However, in the structure in which the LED is mounted on the inclined surface of the base described above, the inclination angle of the optical axis of the LED is precisely adjusted to the desired angle by the processing accuracy of the inclined surface, the manufacturing variation of the LED, or the mounting accuracy of the LED. It is difficult. Furthermore, in this structure, in order to adjust the inclination angle of the optical axis of the LED after being attached to the base, it is necessary to remove the LED from the base, which is an extremely troublesome operation.

Unexamined-Japanese-Patent No. 2004-317470

  Therefore, the present invention has been made to solve the above-mentioned problems, and its main object is to facilitate adjustment of the inclination angle of the optical axis of light emitted from the LED.

  That is, the line light irradiation apparatus according to the present invention is a line light irradiation apparatus that irradiates a work with light in the form of a line along a predetermined direction, and a plurality of holders on which at least one or more LEDs are mounted; A plurality of holders are provided in a row along the predetermined direction, and each holder has a predetermined optical axis of light emitted from the LED with respect to a plane perpendicular to the predetermined direction. It is characterized in that it is attached to the frame so as to be inclined at an angle.

  With such a line light irradiation apparatus, there is no need to accurately determine the position of the LED and the holder on which the LED is mounted, and the light is emitted from the LED mounted on the holder by attaching the holder to the frame. It is possible to adjust the optical axis of the received light. This facilitates the adjustment of the inclination angle of the optical axis of the light emitted from the LED. Therefore, it is possible to easily adjust the angle of the optical axis of the light emitted from each LED in order to keep the illuminance unevenness in the predetermined direction of the linear light within the predetermined allowable range.

It is desirable that the holding body be formed in a block shape, and a plurality of heat radiation fins be provided on the side opposite to the mounting surface of the LED.
With this configuration, the heat dissipation characteristics of the holder can be improved, and a high output (high luminance) LED can also be applied. In addition, if a high output LED is used, the inclination angle of the optical axis of light emitted from the LED is increased to ensure sufficient illuminance on the surface to be irradiated of the workpiece even if the distance between the LED and the workpiece is large. Can.

The heat dissipating fins may be formed along a direction from the light emitting side to the opposite side of the frame.
With this configuration, the cooling performance is improved by the air flowing along the heat dissipating fins. For example, when the line light irradiator irradiates the line light obliquely downward, the air warmed by the heat of the LED flows upward along the radiation fin by the chimney effect and is discharged.

It is desirable to have an angle adjustment mechanism which adjusts an inclination angle to the perpendicular plane of an optical axis of light emitted from the LED.
With this configuration, the adjustment operation of the tilt angle of the optical axis of the light emitted from the LED can be further facilitated.

It is desirable that the angle adjustment mechanism is configured to rotate the optical axis about a rotation center axis set in the vicinity of the LED.
With this configuration, the optical axis can be adjusted while reducing the moving range of the LED.

It is desirable to have a light shielding member which transmits only light within a predetermined angle range among the light emitted from the LED.
With this configuration, of the light emitted from the LED, light outside the predetermined angle range can be blocked, and the directivity of the light emitted from the LED can be improved.

  According to the present invention configured as described above, by attaching the holder on which the LED is mounted to the frame, the optical axis of the light emitted from the LED mounted on the holder can be adjusted. The adjustment operation of the inclination angle of the optical axis of the emitted light can be facilitated.

The schematic diagram which shows the inspection system using the line light irradiation apparatus of this invention. The partially broken perspective view which shows the structure of the line light irradiation apparatus of the embodiment. The front view in the state which removed the front side wall part (front cover) of the line light irradiation apparatus of the embodiment, a bottom view, and a longitudinal cross-sectional view. The six views showing composition of the maintenance object of the embodiment. The schematic diagram which shows the angle adjustment mechanism of the embodiment. The schematic diagram which shows the modification of an angle adjustment mechanism. The schematic diagram which shows the positioning mechanism of modification embodiment. The schematic diagram which shows the positioning mechanism of modification embodiment. The schematic diagram which shows the positioning mechanism of modification embodiment. The schematic diagram which shows the positioning mechanism of modification embodiment. The schematic diagram which shows the structure of the light-shielding member of deformation | transformation embodiment.

  One embodiment of a line light irradiation apparatus according to the present invention will be described below with reference to the drawings.

  The line light irradiation apparatus 100 according to the present embodiment is, as shown in FIG. 1, for irradiating the light receiving surface W1 of the inspection object (workpiece) W in the form of a sheet, for example, with the line light L1. The image pickup device 200 such as the one described above images the surface to be irradiated W1, and the obtained image data is taken in by an image processing device (not shown) and used in a product inspection system or the like that performs automatic surface inspection for the presence or absence of defects. In addition, as an example of the workpiece | work W, what has a light-diffusing surface, such as paper and a nonwoven fabric, is mentioned, and the flaw etc. along the conveyance direction of the workpiece | work W are mentioned as a defect.

  The line light irradiation apparatus 100 of FIG. 1 is disposed to irradiate the line-shaped light L1 from a direction inclined with respect to the direction (vertical direction in the present embodiment) orthogonal to the light receiving surface W1. The imaging axis of the device 200 is disposed orthogonal to the light receiving surface. In addition, the workpiece | work W of this embodiment is conveyed along a predetermined | prescribed conveyance direction.

  Specifically, the line light irradiation apparatus 100 irradiates the line-shaped light L1 extending in a predetermined direction (in the present embodiment, the work width direction orthogonal to the transport direction) to the light receiving surface W1. As shown in FIGS. 2 and 3, a plurality of block bodies 2 as a plurality of holding bodies on which one LED unit 21 is mounted, and the plurality of block bodies 2 are arranged in a row at substantially equal intervals along the predetermined direction. And a frame 3 to be attached.

  The plurality of block bodies 2 are identical to each other and made of, for example, a metal such as aluminum having a substantially rectangular parallelepiped shape, and these are attached to the frame 3 in a row to make a plurality of LED units 21 in the predetermined direction. It becomes the structure arrange | positioned in a line along.

  As shown in FIG. 4, one surface of each block 2 is an LED mounting surface 2A on which the LED unit 21 is mounted. The LED mounting surface 2A is attached to the LED mounting surface 2A by screw fixing or the like so that the LED substrate 22 on which the LED unit 21 is mounted is in close contact, and the heat of the LED unit 21 is easily transferred to the block body 2.

  Each LED unit 21 of this embodiment has one LED 211 and a lens 212 provided on the light emission side front of the LED 211, and emits light with strong directivity (narrow light distribution angle) . Here, the LED 211 is, for example, a surface mount type in which an LED element is disposed at the center of a thin rectangular plate-like package. The LED unit 21 may have a lens portion in the LED 211 itself separately from the lens 212. In this case, the LED unit 21 may not have the lens 212. Further, the LED unit 21 is mounted on one end (the lower end in FIG. 4 and the like) of the LED mounting surface 2A, which is one surface of each block 2, in the longitudinal direction.

  Further, a plurality of heat dissipating fins 2F are integrally formed on the surface 2B opposite to the LED mounting surface 2A of each block body 2 by forming a plurality of grooves 2M. In the present embodiment, the plurality of heat dissipating fins 2F are formed along the longitudinal direction (vertical direction) of the block body 2.

  The frame 3 is a frame having a substantially rectangular parallelepiped shape whose longitudinal direction is the predetermined direction, has a space for accommodating the plurality of block bodies 2 therein, and emits light from the plurality of LED units 21. The line light emitting portion 31 is formed on at least one surface (the lower surface in FIGS. 2 and 3).

  More specifically, the frame 3 has front and rear side walls 32, 33 extending along the longitudinal direction, and left and right side walls 34, 35 that close both longitudinal end portions of the front and rear side walls 32, 33. Further, a slit 3S that constitutes a part of the line light emitting portion 31 is formed between the light emitting side end portions (lower end portions) of the front and rear side wall portions 32 and 33. Further, a notch 3K is formed at the light emitting side end (lower end) of the left side wall 34 so as to be continuous with the slit 3S. The slit 3S and the notch 3K constitute the line light emitting part 31.

  In addition, a base portion 36 extending along the longitudinal direction is provided at an end (upper end) of the rear side wall 33 opposite to the light emission side. The left and right side walls 34 and 35 are fixed to the base portion 36 and the rear side wall 33 by screws or the like, and the front side wall 32 is screwed to the left and right side walls 34 and 35. ing. Thus, only the front side wall portion 32 can be removed, and in a state where the front side wall portion 32 is removed, the attachment work and adjustment of the plurality of block bodies 2 to the frame 3 (rear side wall portion 33) Work can be done.

  The base portion 36 is provided with an attachment groove for attaching the line light irradiation device 100 to an external member (for example, a rack or the like). Further, an electric cable (not shown) for supplying power to the LED 21 extends from the right side wall portion 35. Furthermore, vent holes 3V, 3T, and 3U are formed in the front, rear, and upper portions of the frame 3 (see the cross-sectional view of FIG. 2). Specifically, an air vent 3V is formed between the front side wall 32 and the base 36 or in the front side wall 32, and between the rear side wall 33 and the base 36 or the rear side wall 33. The air vent 3T is formed in the base portion 36, and the air vent 3U is formed in the base portion 36.

  Then, the plurality of block bodies 2 are attached to the rear side wall portion 33 via the fixing mechanism 4 as shown in FIG. Specifically, the fixing mechanism 4 has a screw 43 engaged with the female screw hole 41 formed in the block body 2 from the rear of the rear side wall portion 33 through the through hole 42 formed in the rear side wall portion 33, The rear side wall portion 33 is sandwiched and fixed by the block body 2 and a screw. The fixing mechanism 4 of the present embodiment is configured to fix the inclined block body 2 to the rear side wall portion 33 at the upper and lower two places. At this time, the plurality of block bodies 2 are attached so as to be in substantially the same posture (see FIG. 3).

  Further, the plurality of block bodies 2 are attached in a state where the optical axis 21X of the LED unit 21 is inclined to the left with respect to the direction orthogonal to the slit 3S (see FIG. 5). Here, the optical axis 21X of the LED unit 21 in the present embodiment is an axis indicating the peak intensity of light emitted from the LED unit 21. The light emitted from at least the frontmost (leftmost) LED unit 21 among the plurality of LED units 21 passes through the notch 3K formed in the left side wall 34 (see FIGS. 2 and 3). . With this configuration, the line light irradiation apparatus 100 according to the present embodiment moves the line light L1 from the line light emitting portion 31 extending in the longitudinal direction formed on one surface of the frame 3 toward the direction inclined leftward along the longitudinal direction. It will be irradiated.

  Moreover, the corner | angular part is notched on the right side of the lower end part of each block body 2 (refer FIG. 4 etc.). With this configuration, even when the block bodies 2 are densely arranged in the longitudinal direction, the LED units 21 of the block bodies 2 located on the right side (rear side) of the adjacent block bodies 2 are located on the left side (front side) It does not physically interfere with the block 2 and can not block the light emitted from the LED unit 21 of the block 2 located on the light emission side.

  Furthermore, since the space (groove 2M) formed between the radiation fins 2F opens upward, the air warmed by the heat of the LED 211 convects so as to flow out naturally from the opening at the top due to the chimney effect. In the present embodiment, the air vents 3V, 3T, 3U are formed in the frame 3 separately from the line light emitting part 31 (see FIG. 2), and the warmed air is outside the vents 3V, 3T, 3U. Flow out. The vents 3V, 3T, 3U are located at substantially the same height as the upper end of the block 2 attached to the frame 3 or higher.

  Furthermore, as shown in FIG. 5, the line light irradiation apparatus 100 according to the present embodiment is provided between the block 2 and the frame 3 and is an angle for adjusting the inclination angle of the block 2 with respect to the frame 3. An adjustment mechanism 5 is provided.

  The angle adjustment mechanism 5 is configured together with the fixing mechanism 4, and by making at least one of the upper and lower two through holes 42 as a long hole, the block body 2 is made centering around the other through hole 42. Make the tilt angle of the adjustable.

  In the present embodiment, the upper through hole 42 is a long hole, and the lower through hole 42 is a rotation center. Here, the upper through hole 42 has an arc shape centering on the lower through hole 42.

  With this configuration, the inclination angle of the block body 2 can be continuously adjusted between the inclination angle at which the screw 43 strikes one end of the upper through hole 42 in the circumferential direction and the inclination angle at which the screw 43 strikes the other end in the circumferential direction. Fine adjustment becomes possible with it. By adjusting the optical axis 21X for each of the LED units 21 in this manner, it is easy to adjust the illuminance unevenness in the predetermined direction (longitudinal direction) of the line light L1 within a predetermined allowable range. In addition, since the lower through hole 42 close to the LED unit 21 is the rotation center, the rotation movement radius of the LED unit 21 can be reduced, and the influence due to the position change of the LED unit 21 can be minimized. In this case, assuming that the rotation center is at the upper part of the block 2, when the angle of the block 2 is adjusted, the positional change of the LED unit 21 becomes large, and the interval between the LED units 21 becomes uneven. This is because the distance between the unit 21 and the work W changes, which causes uneven illuminance. In this sense, it is desirable that the center of the lower through hole 42 be located on the back surface side of the LED unit 21, that is, located near the LED 211.

<Effect of this embodiment>
According to the line light irradiation apparatus 100 of this embodiment configured as described above, there is no need to accurately determine the positions of the LED unit 21 (the LED 211 and the lens 212) and the block 2 on which the LED unit 21 is mounted. By attaching the block 2 to the frame 3, the optical axis 21 X of the LED unit 21 mounted on the block 2 can be adjusted. Thereby, the adjustment operation of the inclination angle of the optical axis 21X of the LED unit 21 can be facilitated. Therefore, even if a slight deviation of the optical axis 21X causes uneven illuminance due to the LED unit 21 having strong directivity, the uneven illuminance in a predetermined direction of the line light L1 can be easily made within a predetermined allowable range. It can fit.

  In addition, since the plurality of heat dissipating fins 2F are formed on the opposite side of the block body 2 to the LED mounting surface 2A, the heat dissipating property of the block body 2 can be improved, and the high output (high luminance) LED 211 is used. can do. Further, since the LED 211 with high output (high luminance) can be used, the illuminance on the surface W1 to be irradiated of the workpiece W is increased even if the inclination angle of the optical axis 21X of the LED 211 is increased and the distance between the workpiece W and the LED 211 increases. Can be secured. Therefore, illuminance unevenness in the predetermined direction of the line light L1 can be further reduced.

  Furthermore, since the heat dissipating fins 2F (grooves 2M) are formed in the vertical direction, air warmed by the heat of the LED 21 naturally flows out from the vents 3V, 3T, 3U in the upper portion by the chimney effect.

  Moreover, since the angle adjustment mechanism 5 for adjusting the inclination angle of the block body 2 with respect to the frame 3 is provided, the adjustment operation of the inclination angle of the optical axis 21X of the LED unit 21 can be further facilitated.

The present invention is not limited to the above embodiment.
For example, although the angle adjustment mechanism 5 of the embodiment has a configuration in which one of the upper and lower two through holes 42 is a long hole, as shown in FIG. 6, the upper and lower two through holes 42 are long holes. As well. At this time, the shape of the long hole may be any shape as long as the inclination angle of the block body 2 can be adjusted. This configuration can increase the degree of freedom in positioning the optical axis 21X of the LED unit 21.

  Furthermore, although the fixing mechanism 4 of the said embodiment was what fixed the block body 2 by two places of upper and lower sides, it is good also as a structure which fixes at three or more places besides it is good also as a structure fixed at one place. In the case of a fixing mechanism that fixes at three or more locations, the angle adjusting mechanism is configured such that all the through holes formed in the rear side wall portion are long holes or one remaining through hole is removed in each fixing mechanism. A configuration with a long hole is conceivable. In addition, in the case of the fixing mechanism which fixes one place, an angle adjustment mechanism is comprised by one through-hole formed in the back side wall part in each fixing mechanism.

  Although the block body 2 is fixed to the rear side wall 33 of the frame 3 in the embodiment, it may be fixed to both of the front and rear side walls 32 and 33 of the frame 3.

  In the above embodiment, the optical axis 21X of the LED unit 21 is angularly adjusted by adjusting the attachment position of the block 2 to the frame 3. In addition to or instead of this, the block is The mounting position of the LED unit 21 with respect to 2 may be adjusted.

  Specifically, as shown in FIGS. 7 to 9, the positioning mechanism 6 is provided between the block 2 and the LED substrate 22, and the position of the LED substrate 22 with respect to the block 2 is adjusted. The mounting position of the LED unit 21 may be adjusted.

The positioning mechanism 6 shown in FIG. 7 arranges the elastic member 61 between the LED mounting surface 2A of the block body 2 and the back surface of the LED substrate 22 and places the LED substrate 22 on the LED mounting surface 2A so as to sandwich the elastic member 61. It is a structure to fix a screw.
The positioning mechanism 6 fixes the LED substrate 22 with screws 62 at three locations, and an elastic member 61 is disposed corresponding to each screw 62. The elastic member 61 may be a spacer (shim), a spring, or the like that elastically deforms, such as rubber.
Thus, by adjusting the position of the LED substrate 22 with respect to the block body 2 at three locations, the optical axis 21X of the LED unit 21 can be three-dimensionally adjusted. In addition, the fixed location of the positioning mechanism 6 is not restricted to three places, Two places may be sufficient and four or more places may be sufficient. Further, in the above configuration, a gap is formed between the LED mounting surface 2A and the back surface of the LED substrate 22. Therefore, in order to improve heat dissipation, a heat conductive member such as silicon may be provided in the gap. desirable.

Further, in the positioning mechanism 6 shown in FIG. 8, the convex portion 63 formed on one of the LED mounting surface 2A of the block body 2 or the back surface of the LED substrate 22 abuts on the other, and rotates around the convex portion 63. It is a structure to adjust the inclination angle and fix it by screw.
The positioning mechanism 6 has a convex portion 63 of a protrusion provided by the first flat surface 631 and the second flat surface 632 of the LED mounting surface 2A, and the rear surface of the LED substrate 22 is in contact with the first flat surface 631. The LED substrate 22 rotates around the tip of the convex portion 63 between the first inclination angle and the second inclination angle at which the rear surface of the LED substrate 22 abuts on the second flat surface 632. Here, the back surface of the LED substrate 22 is shaped so as to be rattled against the LED mounting surface 2A in a state in which the back surface of the LED substrate 22 is in contact with the tip of the projection 63. Then, the LED substrate 22 is fixed by the screws 64 provided on both sides of the protrusion 63.
By adjusting the mounting position of the LED unit 21 with respect to the block body 2 in this manner, the optical axis 21X of the LED unit 21 can be two-dimensionally adjusted. The shape of the convex portion 63 may be a polygonal cross-sectional shape such as a trapezoidal cross-sectional shape, in addition to a triangular cross-sectional shape formed of the first flat surface 631 and the second flat surface 632. Further, in the above configuration, a gap is formed between the LED mounting surface 2A and the back surface of the LED substrate 22. Therefore, in order to improve heat dissipation, a heat conductive member such as silicon may be provided in the gap. desirable.

Furthermore, the positioning mechanism 6 shown in FIG. 9 is configured to change the direction (light emission direction) of the optical axis 21X of the LED unit 21 by rotationally moving the LED substrate 22 on the LED mounting surface 2A of the block body 2. is there. For example, the optical axis 21X of the LED unit 21 is inclined, or the LED 211 and the lens 212 are off-axis, and the irradiation position of the light irradiated from the LED unit 21 on the irradiated surface W1 is theoretical from the theoretical position In the case of displacement in the width direction, if uneven illuminance occurs, if the LED substrate 22 is rotationally moved such that the displacement direction is the same as the transport direction of the work W, irradiation in this direction is caused. Since the displacement of the position does not significantly affect the illuminance of the line light L1, it is possible to prevent the uneven illuminance.
In the positioning mechanism 6, a plurality of elongated holes 65 having a circular arc shape along the periphery of the central axis of the LED unit 21 are formed concentrically in the LED substrate 22, and the LED substrate 22 is formed via the elongated holes 65. The LED mounting surface 2A of the block body 2 is fixed by screws 66.
By rotating the LED substrate 22 on the LED mounting surface 2A by this positioning mechanism 6, the optical axis 21X of the LED unit 21 can be adjusted around the rotation center axis.

In the positioning mechanism 6 described above, the LED 211 and the lens 212 are moved integrally, but as shown in FIG. 10, for example, the optical axis 21 X of the LED unit 21 is moved by moving the lens 212 relative to the LED 211 When the LED 211 and the lens 212 are off-axis, the direction (light emission direction) of the optical axis 21X of the LED unit 21 may be changed. Also in this case, the same effect as that of the positioning mechanism 6 of FIG. 9 can be obtained, or the direction of the optical axis 21X can be matched with the theoretical angle.
The positioning mechanism 6 has a support member 67 for supporting the lens 212 at the front of the light emission side of the LED 211, and the support member 67 is moved relative to the LED mounting surface 2A or with respect to the support member 67. The lens 212 is configured to be moved relative to one another.
With this configuration, the direction of the optical axis 21X of the LED 211 can be changed by adjusting the position of the lens 212 with respect to the LED 211, and by positioning and attaching the block body 2 to the frame 3, the light of the LED unit 21 The degree of freedom in positioning the shaft 21X can be increased.

  Furthermore, as shown in FIG. 11, a light blocking member 7 for blocking the light spreading beyond a predetermined angle among the light emitted from the LED unit 21 in front of the light emission side of the LED unit 21 mounted on each block body It may be provided. The light shielding member 7 is configured to also cover the lower side (work side) of the LED unit 21. Further, the light shielding member 7 is for improving the directivity of the light emitted from the LED unit 21, and the light transmitting portion 71 for transmitting the light within the predetermined angle range is formed. Even in this manner, only light from a predetermined angle can be irradiated toward the work W. In addition, although the light transmission part 71 of FIG. 11 is a through-hole which penetrates the light shielding member 7, it may be comprised using a light transmission material. Further, as shown in FIG. 11A, the light blocking member 7 blocks light from the LED unit 21 of the block 2 located behind the block 2 by providing the light blocking member 7 on the block 2 located forward. It is good also as composition, and as shown in Drawing 11 (B), it may provide in block object 2 in which the LED unit 21 concerned was provided so that it may be located ahead of LED unit 21.

  Moreover, as far as the frame 3 is concerned, it does not have a space for accommodating the plurality of block bodies 2 inside as long as it has a generally flat attachment wall portion to which the plurality of block bodies 2 are attached. good. In addition, if the blocks 2 are provided in a plurality of rows and the line light L1 is formed by the light from the LED units 21, the illuminance on the irradiation surface W1 of the work W can be further enhanced. In this case, if the plural rows of the staggered arrangement are used, uneven illuminance can be further reduced.

  In the embodiment, the vents are provided at three locations on the front side wall side, the rear side wall side, and the base side, but they are provided on any one of the wall side and the line light irradiator 31 A flow path may be formed between them so that the air warmed by the heat of the LED is discharged.

  In addition, the present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the invention.

100 ··· Line light irradiation device 2 ··· Block body 2A ··· LED mounting surface 2F ··· Heat radiation fin 2M ··· Space formed between heat radiation fins 21 ··· LED unit 21 X ··· Optical axis 211 ... LED
212 ... lens 22 ... substrate 3 ... frame 5 ... angle adjustment mechanism

Claims (6)

A line light irradiation apparatus for irradiating a work with light in the form of a line along a predetermined direction, wherein
A plurality of holders on which at least one or more LEDs are mounted;
A frame in which the plurality of holders are accommodated, the plurality of holders are attached in a row along the predetermined direction, and a line light emitting portion for emitting light from the plurality of LEDs is formed And
Each of the holders is attached to the frame such that an optical axis of light emitted from the LED is inclined at a predetermined angle with respect to a plane perpendicular to the predetermined direction ,
The frame includes a pair of front and rear side walls extending along the predetermined direction, and a pair of left and right side walls closing the both ends in the predetermined direction of the pair of front and rear side walls.
The slit formed in the predetermined direction between the light emission side end portions of the pair of front and rear side wall portions, and the light emission side end portion of one of the left and right side wall portions The line light irradiation apparatus comprised from the notch part formed so that the said slit might be followed .   The line light irradiation apparatus according to claim 1, wherein the holding body is formed in a block shape, and a plurality of heat radiation fins are provided on the side opposite to the mounting surface of the LED.   The line light irradiation apparatus according to claim 2, wherein the heat radiation fin is formed along a direction from the light emission side to the opposite side of the frame.   The line light irradiation apparatus according to any one of claims 1 to 3, further comprising an angle adjustment mechanism that adjusts an inclination angle of the optical axis of the light emitted from the LED with respect to the vertical plane.   5. The line light irradiation apparatus according to claim 4, wherein the angle adjustment mechanism is configured to rotate the optical axis about a rotation center axis set in the vicinity of the LED. The line light irradiation apparatus according to any one of claims 1 to 5 , wherein a vent is formed in at least one of the pair of front and rear side wall portions of the frame .