JP4068588B2 - Light irradiation device - Google Patents

Description

  The present invention relates to a light irradiation apparatus that irradiates an object such as a product in a factory or the like, and is suitably used for appearance inspection and reading of symbols written on a surface.

  Conventionally, for example, a system has been known in which a suitable illumination environment is created by irradiating an object such as a product, and then the object is imaged with a CCD camera to perform automatic appearance inspection and automatic symbol reading. ing.

In such a system, when it is necessary to irradiate light from an observation axis (imaging axis) of a camera or the like, such as when illuminating the entire surface of an object, a configuration as shown in Patent Document 1 is conventionally used. Is going. Specifically, as shown in FIG. 25, the principle diagram includes a half mirror HM installed at an inclination of 45 ° on the observation axis C of the camera 6 and the like, and a light source unit A5 that emits light from the side. The light irradiation device A1 is used. According to such a configuration, the light emitted from the light source unit A5 is reflected by the half mirror HM, travels in the same direction as the observation axis C, and is irradiated onto the object W. Further, since the light from the object W passes through the half mirror HM and reaches the camera 6, it is possible to image the object.
Japanese Patent Laid-Open No. 10-21729

  However, such a light irradiation apparatus A1 has a disadvantage that the entire apparatus is particularly large in the direction of the observation axis C because of having a half mirror HM inclined at 45 °.

  In addition, since such a large light irradiation device A1 is interposed between the object W and the camera 6, the camera 6 cannot be brought close to the object W. For example, as shown in FIG. In the case where the object W is imaged from the observation hole 7b provided in the all-sky illumination device 7, the field of view becomes narrow, and there is a problem that only a small area can be imaged.

  Furthermore, since the optical path length from the light source unit A5 to the object W must be increased because the half mirror HM is interposed, the object W can be irradiated with light only at an angle close to vertical. Since the object W is too close to the parallel light in this manner, for example, in the case of a substrate on which the object W is solder-plated, a shadow can be formed by slight unevenness on the surface. If the object W is obstructed or the object W is mirror-like like a semiconductor wafer, the picked-up image becomes dark with a slight inclination. May occur.

  In addition, since the optical path length from the light source unit A5 to the object W has to be increased, the light emission of the light source unit A5 is combined with the fact that the camera 6 cannot be brought closer to the object W to some extent as described above. There is a need to increase the amount, which can cause heat problems and the like.

  Therefore, the present invention is capable of drastically reducing the flatness and size of the light irradiation device of this type capable of irradiating the object from the direction coaxial with the observation axis of the observation means, and solves the above problems all at once. This is the main desired issue.

  That is, the light irradiation apparatus according to the present invention includes a large number of reflective portions arranged side by side so that a fine gap is formed therebetween, and a light source portion installed at a position where light can be directly irradiated to the respective reflective portions. And configured to be able to irradiate the object with the light reflected by the reflecting portion, and to transmit the light reflected by the object to the opposite side through the gap.

  If this is the case, the reflected light from the reflecting part can illuminate the observation axis of the camera or the like in the coaxial direction, and the object can be viewed on the opposite side through a gap or captured by a CCD camera. By doing so, the inspection of the object can be performed. Here, “reflection” includes irregular reflection (scattering).

  Therefore, these reflecting portions may be provided side by side on a plane with a minute gap, and the light source portion may be provided, for example, in an annular shape around these reflecting portions. Can be flat with small dimensions.

  As a result, the observation means such as a camera can be made much closer to the object than in the prior art, and the field of view can be expanded.

  Further, by making the distance between the reflecting portion and the object close to each other, the object can be irradiated with light having a larger incident angle. As a result, the object can be illuminated with more uniform scattered light, and the quality of illumination for inspection or the like can be improved.

  Furthermore, since the light from the light source unit directly reaches the reflection unit and is reflected there, the light from the light source unit can be efficiently transmitted to the object. In addition to this, since the observation means such as a camera can be brought close to the target object as described above, a light source part with a large light quantity as in the conventional case is not required, a heat problem hardly occurs, and a further compact size. It becomes possible. Here, “directly” means that it does not include light reflected on the way, and for example, “directly” also means that the light source portion passes through a transparent medium such as glass and reaches the reflecting portion. include.

  Specifically, a configuration in which the reflecting portion is supported by a flat plate-like transparent support is preferable.

  As a preferred embodiment for forming the reflection part, there can be mentioned one in which the reflection part is provided on the surface of the transparent support on the illumination object side.

  If the reflective part includes a reflective layer that forms the reflective surface and a light blocking layer formed on the back side of the reflective layer, when the object is observed with a camera or the like, light is reflected at the reflective part. Inspection and the like can be suitably performed while preventing irregular reflection. The light blocking layer desirably absorbs or blocks all light, but may absorb or block part of the light.

  In order to be able to irradiate the object with a more uniform diffused light, it is preferable that the reflective layer contains a light diffusing member.

  In order to promote flattening, it is desirable that the light source unit has a plurality of LEDs arranged in a ring shape.

  As an aspect of surrounding the object from the whole so that more uniform light can be emitted, the LED group further includes a plurality of transmission diffusion portions arranged on the light emission direction side of the LED group. An example of the configuration is such that light is emitted through a gap between the diffusion portions.

  When used together with a so-called dome illumination that has a light emitting surface capable of covering the object from almost the whole sky except for the observation hole, the reflector is arranged in the observation hole. do it.

  Since the light irradiation apparatus according to the present invention can be made thin as described above, it may be considered that the light irradiation apparatus can be directly attached to an imaging means such as a CCD camera for imaging the object. In this case, it is preferable that the reflection unit is a region having a size and a shape corresponding to the imaging surface of the imaging unit and is positioned in front of the imaging unit when attached to the imaging unit.

  If the reflection parts are regularly arranged in the same shape, interference fringes may occur due to the influence of diffraction or the like. In order to effectively avoid this, the pitch between the reflecting portions is set at random, and the reflecting portions are arranged irregularly, or have a different shape in plan view, and different in shape from each other. Is desirable.

  In order to enhance the diffusing action when light is reflected by the reflecting section, it is preferable to further include a transparent film that covers the reflecting section and increases the diffusing action of light. If this is the case, the light is refracted when incident on the transparent film, and the light is reflected and reflected at an angle closer to the perpendicular to the surface of the reflecting portion than the light without the transparent film. In this case, the diffusion action increases. This transparent film also serves to protect the reflective portion.

  An embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIGS. 1 to 4, the light irradiation device 1 according to the present embodiment has an annular frame 2 and an equal-thickness flat plate that is fitted and held in the inner periphery of the upper end of the frame 2. A transparent support 3; a large number of reflecting parts 4 arranged on the bottom surface (lower surface) 3a of the transparent support 3; and a light source part 5 provided so as to circulate around the inner periphery of the lower end of the frame 2. The lower surface 3a of the transparent support 3 is disposed so as to face the object W, and the surface of the object W is irradiated with light. In addition, the upper and lower sides described in this description are convenient directions as seen from the drawings, and do not determine the absolute installation direction of the light irradiation device 1.

  Each part will be described in detail.

  As shown in FIGS. 1 and 2, the frame 2 has a square shape in plan view, and includes a frame main body 21 and a thin plate-like bottom plate 22 attached to the lower surface of the frame main body 21. .

  The transparent support 3 is formed of glass or the like having a flat plate shape with a rectangular shape in plan view, and its peripheral edge is fitted into a groove 2 a provided at the upper end of the inner periphery of the frame body 21.

  As shown in FIGS. 3 and 4, each of the reflecting portions 4 is very small and very thin on the order of microns, and the transparent portion 4 is formed so that a fine gap S is formed between them. They are arranged vertically and horizontally at intervals of about 0.2 mm over substantially the entire lower surface 3a excluding the peripheral edge of the support 3. Each reflection part 4 has a cloud shape in which at least a part thereof is different in shape in plan view, and covers and transparently supports a reflection layer 41 that irregularly reflects light and an upper surface of the reflection layer 41 on the side opposite to the object. A layer structure including a light blocking layer 42 directly attached to the lower surface 3a of the body 3 is formed. Note that FIG. 3 is a schematic diagram in which the thickness of the reflecting portion is exaggerated.

  The reflective layer 41 is formed of, for example, a white pigment containing a particulate reflective filler (not shown), which is a light diffusing member, and mainly reflects light on its surface. Although this is very thin and has some light transmittance, a part of the light entering the inside is diffused and reflected by the reflection filler. On the other hand, the light blocking layer 42 is formed using a matte black material (such as brown or gray) such as chromium oxide (CrO2). In this embodiment, the chromium oxide is used for the purpose of further improving the reflectance. The upper surface of the layer 421 is further provided with a mirror-like chrome layer 422. That is, light that has entered the reflective layer 41 is reflected by the surface of the chromium layer 422.

  These reflecting portions 4 are formed by a method as shown in FIGS. First, the lower surface 3a of the transparent support 3 is covered with the chromium layer 422 and the chromium oxide layer 421 in this order, and the lower surface of the chromium oxide layer 421 is further covered with the photopolymer PP. Next, a laser beam is irradiated to a site where the gap S is formed, and the photopolymer PP at that site is removed. Then, the chromium layer 422 and the chromium oxide layer 421 exposed by removing the photopolymer PP by laser light irradiation are removed by etching. Thereafter, by removing the photopolymer PP, only the cloud-shaped light blocking layer 42 is formed first. Finally, although not shown, the reflective portion 4 is formed by applying a pigment for forming the reflective layer 41 to the lower surfaces of the light blocking layers 42 using a printing technique. In this embodiment, the reflective layer 41 is made smaller than the light blocking layer 42 in order to allow a slight misalignment such as printing.

  The light source unit 5 includes a large number of LEDs 51 arranged at equal intervals so as to form an annular shape along the inner periphery of the lower end of the frame body 2, and a substrate 52 that holds the LEDs 51. Then, by holding the light source unit holding groove 2b formed by the frame body 21 and the bottom plate 22 in a posture in which the optical axis of the LED 51 is slightly inclined upward, at least a part of the light emitted from the LED 51 is obtained. It is configured to directly reach the reflecting portion 4.

  The light irradiation device 1 is arranged so that the lower surface 3a of the transparent support 3 faces the object W, and an observation means such as a CCD camera 6 is arranged on the upper side of the transparent support 3 to It can be suitably used when performing surface inspection or symbol reading of the object W.

  The operation will be specifically described below.

  First, when light is irradiated from the light source unit 5, the light is irregularly reflected by the reflection layer 41 of the reflection unit 4, and is irradiated onto the object W as uniformed diffused light. Thus, the object W is illuminated with uniform light.

  On the other hand, the light reflected by the object W passes through the transparent support 3 through the gap S between the reflecting portions 4 and is captured by the CCD camera 6. That is, the object W illuminated as described above can be imaged by the CCD camera 6, and surface inspection and symbol reading of the object W can be performed. It should be noted that the size or pitch of the gap S and the reflection portion 4 is optimal so that observation is not hindered by using the separation distance between the CCD camera 6 and the reflection portion 4, the separation distance between the CCD camera 6 and the object W, etc. as parameters. What is necessary is just to stipulate. For example, when the separation distance between the CCD camera 6 and the reflecting portion 4 is small, the size of the gap S or the reflecting portion 4 or the pitch may be increased correspondingly, and vice versa.

  Specifically, the distance between the CCD camera 6 and the object W is D, the pitch between the reflecting parts 4 is P, the distance between the reflecting parts 4 and the object W is L, the observation diameter of the object W is d, If the focal depth of the CCD camera 6 is B and the reflectance is δ (mirror is 1.0),

  P = a · L · d / (D · B · δ).

  Here, a is a coefficient.

  As described above, according to the present embodiment, the reflected light from the reflecting unit 4 can illuminate the observation axis C of the CCD camera 6 in the coaxial direction, and the object W is imaged by the CCD camera 6 through the gap S. And inspection can be performed.

  Thus, since these reflecting portions 4 are arranged side by side on the thin plate-like transparent support lower surface 3a, and the light source portion 5 is also provided annularly around the reflecting portions 4 using the LEDs 51, the entire apparatus 1 is It can be made flat with a small dimension along the observation axis C.

  As a result, the CCD camera 6 can be made much closer to the object W than in the prior art, and the field of view can be expanded.

  Moreover, since it is also possible to make the distance of the reflection part 4 and the target object W close, the target object W can be irradiated with the light of a larger incident angle. As a result, the object W can be illuminated with more uniform scattered light, and the quality of illumination for inspection or the like can be improved.

  Furthermore, since the light from the light source part 5 reaches | attains the reflection part 4 directly and reflects there, the light from the light source part 5 can be efficiently transmitted to the target object W. In addition to this, since the CCD camera 6 can be brought close to the object W as described above, a light source part having a large light quantity as in the conventional case is not required, and heat problems are unlikely to occur. Is also possible.

  In particular, in the present embodiment, the light blocking layer 42 can prevent the light from being transmitted through the reflecting portion 4 or irregularly reflected to the camera 6 side, so that inspection or the like can be suitably performed. Moreover, since the reflection part 4 is a very thin structure, the reflection of the light in the side surface can also be prevented.

  In addition, if the distance between the reflection unit 4 and the object W is close, a part of the light emitted from the light source unit 5 directly irradiates the object W, so that low-angle illumination is performed at the same time. Can do. Therefore, what conventionally performed the low-angle illumination and the coaxial illumination using the two light irradiation devices 1 can be performed by a single device. Of course, the LED 51 may be installed such that its optical axis faces the radial direction, or may face slightly downward.

  In addition, when image processing is normally performed in a square area, since the area where the reflection units 4 are arranged is formed in a square, an image of the object W can be captured without waste.

  Next, a second embodiment of the present invention will be described below.

  In the present embodiment, as shown in FIGS. 8, 9, and 10, the reflecting portion 4 is made smaller and thinner, and has a diameter of about 50 μm and a thickness of 0.1 to 0.2 μm. Of course, a cloud shape may be used as in the previous embodiment. Specifically, this has a layer structure including an intermediate layer 43 directly attached to the lower surface 3a of the transparent support 3, and a reflective layer 41 that covers the lower surface and side surfaces of the intermediate layer 42 and diffuses and reflects light.

  The reflective layer 41 is made of a metal such as nickel (Ni) or chromium (Cr), and has a plurality of irregularities on its surface so as to be rough, and mainly diffuses and reflects light. . On the other hand, the intermediate layer 43 is an ITO film which is a conductive thin film, and has a property that a metal can be coated on the surface thereof by plating or the like.

  These reflecting portions 4 are attached to the transparent support 3 as shown below, for example.

  First, as shown in FIG. 11, an intermediate layer 43 is formed by depositing an ITO film on the lower surface 3a of the transparent support 3 by a method such as sputtering or vapor deposition. Further, the lower surface of the intermediate layer 43 is made of photopolymer PP. cover. Next, as shown in FIG. 12, the portion where the gap S is formed is irradiated with laser light or the like, and the photopolymer PP at that portion is removed. Then, as shown in FIG. 13, the intermediate layer 43 exposed by removing the photopolymer PP is removed by etching, and then the photopolymer PP is removed, whereby only the disc-shaped intermediate layer 43 is formed. Thereafter, the lower surface 3a of the transparent support 3 is plated as shown in FIG. At this time, since the plating does not adhere to the glass but adheres only to the ITO film, a metal layer such as nickel (Ni) or chromium (Cr) is formed as the reflective layer 41 only on the lower and side surfaces of the ITO film. Thus, the reflection unit 4 is generated. At this time, no metal layer is formed on the exposed portion of the transparent support 3 without the ITO film, and a gap S is formed between the reflecting portions 4.

  Therefore, according to this embodiment having such a configuration, only the lower surface 3a of the transparent support 3 is uniformly plated, and only the lower surface and side surfaces of the ITO film forming the intermediate layer 43 remaining after etching are not displaced. Not only can the reflective layer 41 be formed with a high degree of accuracy, but also an alignment operation that is required in the method of forming the reflective layer 41 using a printing technique is not required, thereby saving labor.

  In addition, since the reflective layer 41 can be formed with such a high accuracy, a smaller reflective portion 4 can be formed. For example, by increasing the gap S, the light reflected by the object W can be converted into a CCD. The object W can be illuminated with highly uniform scattered light by efficiently capturing with the camera 6 and providing many reflecting portions 4 on the lower surface 3 a of the transparent support 3.

  In addition, since the ITO film forming the intermediate layer 43 can be made extremely thin as compared with the chrome forming the light blocking layer 42 in the previous embodiment, the ITO film that is emitted from the LED 51 is formed in this way. It is possible to more completely prevent the light that does not depend on the object W reflected on the side surface of 4 from entering the CCD camera 6.

  The present invention is not limited to the above embodiment.

  For example, as shown in FIGS. 14 and 15, a large number of transmission diffusion parts 4 </ b> A may be further provided on the light emission direction side of the light source part 5 with fine gaps SA therebetween. Unlike the reflection part 4, the transmission diffusion part 4 A is a cloud-shaped part composed of only a transmission diffusion layer 41 A for transmitting and diffusing light, and is a thin flat plate-like second arranged vertically below the transparent support 3. On the inner surface of the transparent support 3A, the transmissive diffusion layer 41A is arranged side by side so as to face inward. A part of the light from the LED 51 is directly emitted through the gap SA, and the other light is emitted through the transmission diffusion portion 4A.

  If it does in this way, it will become possible to surround the target object W almost completely from the circumference | surroundings, and to illuminate uniformly by the reflection part 4 and the transmission diffusion part 4A.

  In addition, as another method for uniformly illuminating the object W by completely completely surrounding the object W, as shown in FIG. 16, a semi-concave spherical surface capable of covering the object W from substantially the whole sky except the observation hole 7b. You may make it use with the whole sky illuminating device (what is called a dome illuminating device) 7 which has the light-emitting surface 7a of the shape. In this case, the light irradiation device 1 is arranged so that the reflecting section 4 is brought close to the observation hole 7b.

  Further, as shown in FIG. 17, the transparent support 3 itself may be partially spherical or hemispherical.

  Further, since it can be made thin as described above, as shown in FIG. 18, a configuration in which an attachment portion 8 is provided so that it can be directly attached to the imaging means such as the CCD camera 6 may be adopted. In that case, it is preferable that the reflection unit 4 is an area having a size and a shape corresponding to the imaging surface of the imaging unit and is located in front of the imaging unit 6 when attached to the imaging unit 6. In this example, the transparent support 3 is circular in plan view although not shown.

  In addition, you may provide a reflection part in the upper surface of a transparent support body, ie, the surface by the side of a counter object. Even in such a case, it goes without saying that the reflective layer is disposed so as to face the object side.

  Further, for example, as shown in FIG. 19, each reflecting portion 4 may be continuously provided so as to form a mesh and formed into a sheet shape, and this may be directly stretched on the frame to have a structure without a transparent support. However, as shown in FIG. 23, the reflection part 4 or the transmission diffusion part 4A may have an equal shape, and may be regularly arranged at an equal pitch.

  Furthermore, since the intensity of light emitted from the light source unit becomes weaker in the central part of the reflecting part, the surface area of the central reflecting part is the largest, and if it is made smaller toward the end, it becomes more uniform on the object. It can irradiate light of high intensity.

  Further, the reflecting portion is not limited to a substantially equal thickness, and as shown in FIGS. 20 and 21, the reflecting surface may be curved or inclined, and the reflecting surface may be inclined or inclined for each reflecting portion. The degree of curvature may be random. Furthermore, for example, as shown in FIG. 22, the reflecting portions may be annular and arranged concentrically.

  In FIG. 24, the surface of the reflecting portion 4 attached to the transparent support 3 is covered with a transparent film F made of resin or the like. In this figure, the transparent film F covers not only the surface of the reflecting portion 4 but also the surface 3a of the transparent support 3, but it goes without saying that only the surface of the reflecting portion 4 may be covered.

  If this is the case, as shown in the figure, the light is refracted when light enters the transparent film F, and is closer to the surface of the reflecting portion 4 than the surface without the transparent film. Since the light hits, the diffusion effect at the time of reflection increases. This transparent film also serves to protect the reflective portion.

  Of course, a light source other than the LED may be used as the light source unit. The reflection part is not limited to a cloud shape, and the arrangement is not limited to vertical and horizontal, and any arrangement may be used as long as a gap is provided.

  In addition, the intermediate layer in another embodiment is thin, and the same effect can be obtained as long as it is not limited to an ITO film but can be formed on a transparent support and can be plated.

  In addition, if the film forming the intermediate layer is more transparent and can be plated in a limited manner, it is not necessary to perform etching to form the reflective portion. It is possible to save labor.

  Further, as a method of forming the reflection portion and the gap, after plating the intermediate layer, a photopolymer is applied and etching is performed to remove the metal and the intermediate layer used for plating, or at this time, the intermediate layer If is a transparent film, only the metal used for plating may be removed.

  In addition, the present invention is not limited to the above illustrated example, and various modifications can be made without departing from the spirit of the present invention.

The center vertical positive end view which shows the internal structure of the light irradiation apparatus in one Embodiment of this invention. The top view of the light irradiation apparatus in the embodiment. The partial enlarged front view which mainly shows the reflection part of the light irradiation apparatus in the embodiment. The partial expanded bottom view which mainly shows the reflection part of the light irradiation apparatus in the embodiment. Explanatory drawing which shows the manufacture procedure of the reflection part in the embodiment. Explanatory drawing which shows the manufacture procedure of the reflection part in the embodiment. Explanatory drawing which shows the manufacture procedure of the reflection part in the embodiment. The partial enlarged front view which mainly shows the reflection part of the light irradiation apparatus in 2nd Embodiment. The elements on larger scale which mainly show the reflection part of the light irradiation apparatus in FIG. The partial expanded bottom view which mainly shows the reflection part of the light irradiation apparatus in 2nd Embodiment. Explanatory drawing which shows the manufacture procedure of the reflection part in 2nd Embodiment. Explanatory drawing which shows the manufacture procedure of the reflection part in 2nd Embodiment. Explanatory drawing which shows the manufacture procedure of the reflection part in 2nd Embodiment. The center vertical positive end view which shows the internal structure of the light irradiation apparatus in other embodiment of this invention. FIG. 15 is a detailed view of part A in FIG. 14. The center longitudinal regular end view which shows the light irradiation apparatus etc. in further another embodiment of this invention. The center longitudinal regular end view which shows the light irradiation apparatus in further another embodiment of this invention. The center longitudinal regular end view which shows the light irradiation apparatus in further another embodiment of this invention. The partial bottom view which shows the reflection part in other embodiment of this invention. The partial expanded front view which mainly shows the reflection part of the light irradiation apparatus in other embodiment of this invention. The partial expanded front view which mainly shows the reflection part of the light irradiation apparatus in other embodiment of this invention. The bottom view in FIG. The partial expanded bottom view which mainly shows the reflection part of the light irradiation apparatus in other embodiment of this invention. The fragmentary sectional view which mainly shows the reflection part in other embodiment of this invention. Explanatory drawing which shows the test | inspection system containing the conventional light irradiation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light irradiation apparatus 3 ... Transparent support 4 ... Reflection part 41 ... Reflection layer 42 ... Light shielding layer 5 ... Light source part 51 ... LED
6 ... Imaging means (CCD camera)
DESCRIPTION OF SYMBOLS 7 ... All-sky illumination device 7a ... Light-emitting surface 7b ... Observation hole 8 ... Mounting part 4A ... Transmission diffusion part S ... Gap W ... Object F ... Transparent film

Claims (13)

A large number of reflective portions arranged side by side so as to form a gap, and a light source portion installed at a position where light can be directly irradiated to each reflective portion, and the reflective portion is plated on a thin intermediate layer The inspection is configured so that the object reflected by the reflection part can be irradiated and the light reflected by the object can be transmitted to the opposite side through the gap. light irradiation apparatus of use. A plurality of reflective portions arranged side by side so as to form a gap, and a light source portion installed at a position where light can be directly irradiated to each of the reflective portions, the reflective portion being covered with a transparent film, An inspection light irradiating apparatus configured to be able to irradiate an object with light reflected by a reflecting portion and to be able to transmit light reflected by the object to the opposite side through the gap. The light irradiation apparatus for inspection according to claim 1 , further comprising a flat plate-like transparent support that supports the reflection portion. The light irradiation apparatus for inspection according to claim 3 , wherein the reflection section is provided side by side on a surface of the transparent support on the object side. The inspection according to claim 1, 2 , 3, or 4 , wherein the reflection part includes a reflection layer that reflects light and a light blocking layer that absorbs or blocks light formed on an anti-object side of the reflection layer. light irradiation apparatus of use. The light irradiation apparatus for inspection according to claim 5, wherein a light diffusing member is contained in the reflective layer. Said light source unit, according to claim 1, 2, 3, 4 and has a plurality of LED having arranged annularly, the light irradiation apparatus for inspection of 5 or 6. A plurality of transmission diffusion portions arranged on the light emission direction side of the light source unit are further provided, and light is emitted from the light source unit through the gap between the transmission diffusion unit and the transmission diffusion unit. Item 8. A light irradiation apparatus for inspection according to Item 7 . It is used with an all-sky illumination device having a light emitting surface capable of covering the object from almost the whole sky excluding the observation hole, and the reflection portion is arranged in the observation hole. The light irradiation apparatus for inspection according to 1 , 2 , 3 , 4 , 5 , 6 or 7 . An attachment part for attaching to the imaging means for imaging the object is further provided, and the reflection part is an area having a size and shape corresponding to the imaging surface of the imaging means when attached to the imaging means. claim that is configured to be positioned in front Te 1,2,3,4,5,6,7, light irradiation apparatus for inspection of 8 or 9. Wherein each reflection unit, without a plan view different shapes, yet claim 5, 6, 7, 8 is shaped different from each other, the light irradiation apparatus for inspection of 9 or 10, wherein . Claim 1,2,3,4,5,6,7,8 the pitch is set at random between the reflective portion, 9 or 10 for inspection of the light irradiation apparatus according. A transparent film that covers the reflective portion and increases a light diffusion effect is further provided.
3 , 4 , 5 , 6 , 7, 8 , 9 , 10 , 11 or 12 light irradiation apparatus for inspection