JP2008209501A - Optical fiber illuminating device and hologram inspection apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hologram inspection apparatus for stably detecting diffraction light from a hologram and detecting the authenticity and deficiency of the hologram stuck on an inspection medium. <P>SOLUTION: The hologram inspection apparatus includes: a support mechanism 14 which supports the inspection medium with the hologram stuck; the optical fiber illuminating device 16 which irradiates the hologram with light; an imaging part 20 which images the diffraction light from the hologram; an image processing part which performs the image processing of the image imaged by the imaging part; and a determination processing part which determines defects such as deficiency and exhaustion of the hologram and the authenticity of the hologram on the basis of the processed image. The optical fiber illuminating device includes: an emission surface disposed facing in parallel to the inspection medium; and the optical fiber with an emission side end part disposed with inclination related to the emission surface by an angle corresponding to the specified incident angle on the hologram, so that the hologram is irradiated with the light. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical fiber illuminating device that irradiates illumination light to an inspection medium such as a paper sheet or a card, and a hologram inspection device that inspects a hologram attached to the inspection medium.

  A diffractive optical change element represented by an embossed hologram (hereinafter referred to as a diffractive OVD) is an element that has been processed to cause a light diffraction phenomenon on its surface. It has a pattern that emits various colors. When light is incident on the hologram from a specific angle, the diffracted light is reflected at a specific angle according to the pitch and direction of the diffraction grating separately from the regular reflection light. Since holograms have optical characteristics that are different from those of normal printing, they are used as security threads for paper coupons such as gift certificates and securities, and cards such as credit cards. It has been realized.

  For the purpose of quality control of such paper sheets and cards, various inspection apparatuses for inspecting holograms attached to these paper sheets and cards have been proposed. As such an inspection apparatus, an apparatus is known in which light is applied to a hologram from a specific angle and a light receiving system is disposed at a position where diffracted light is emitted to determine the authenticity of the hologram. For example, Patent Document 1 discloses an inspection in which authentication is performed using a light projecting system that projects measurement light and a plurality of light receiving systems that respectively detect a plurality of reflected diffracted lights reflected and diffracted by a diffraction pattern of a hologram. An apparatus is disclosed. For example, Patent Document 2 discloses an apparatus that irradiates light by arranging a plurality of Selfoc (registered trademark) lenses at a predetermined angle as an illumination apparatus that illuminates a hologram.

In general, an illuminating device using an optical fiber that is less expensive than a SELFOC lens has an optical fiber light guide, and the strands of the optical fiber are arranged side by side perpendicular to the exit surface of the optical fiber light guide. ing. One end of the optical fiber light guide is disposed on the light source side, and light emitted from the light source travels through the optical fiber and is emitted from the exit surface of the other end.
JP 2001-307173 A JP 2002-221494 A

  When detecting the reflected diffracted light of the hologram, it is necessary to irradiate the hologram with light from a specific angle. At this time, when the conventional optical fiber light guide is used to irradiate the hologram with light from a specific angle, the exit surface of the optical fiber light guide is disposed at a specific angle with respect to the hologram. In this case, in the irradiated region, the light is strongly concentrated in the portion near the exit surface of the optical fiber light guide, and the light is diffused weakly in the portion far from the exit surface. Therefore, the spread of light and the light intensity in the detection visual field become non-uniform. In the hologram detection apparatus using such illumination, information in the entire detection visual field cannot be stably obtained, which adversely affects detection accuracy.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an optical fiber illuminating device capable of illuminating a detection region with a stable spread and light intensity, and a hologram inspection device including the same. is there.

In order to achieve the above object, an optical fiber illuminating device according to an aspect of the present invention is an optical fiber illuminating device that irradiates an inspection surface, and is formed of a light source and a plurality of strands, and guides light from the light source to an emission end. An optical fiber that exits from the optical fiber, and a guide member that supports the exit end of the optical fiber and has an exit surface that faces the inspection surface in parallel.
At the emission side end of the optical fiber, the plurality of strands are arranged side by side with a predetermined angle not including 90 degrees with respect to the exit surface of the guide member, and the exit ends of the plurality of strands Is located on the exit surface.

  A hologram inspection apparatus according to another aspect of the present invention is a hologram inspection apparatus that detects a hologram having a diffraction pattern that is diffracted and reflected in a certain direction with respect to light incident at a specific incident angle. A support mechanism for supporting the inspection medium; an exit surface disposed in parallel to the inspection medium; and an optical fiber disposed to be inclined with respect to the exit surface by an angle corresponding to the specific incident angle. And an optical fiber illuminating device that irradiates the hologram with light, an imaging unit that images diffracted light from the hologram, an image processing unit that performs image processing on an image captured by the imaging unit, and the processing And a determination processing unit that performs determination of hologram deficiency, exhaustion, and authenticity from an image.

  According to the above configuration, it is possible to provide an optical fiber illumination device that can illuminate a detection region with a stable spread and light intensity, and a hologram inspection device that can stably detect a hologram.

Hereinafter, a hologram inspection apparatus according to a first embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1 and FIG. 2, the hologram inspection apparatus holds a card 12 with a hologram 10 as an inspection medium and supports and conveys the card 12 including the hologram 10 along a predetermined direction B. Are provided with an optical fiber illuminating device 16 that irradiates the inspection surface 12a with inspection illumination light, and an imaging unit 20 that images diffracted light from the hologram.

  The hologram 10 includes, for example, a circular metal foil 10a attached to the card 12, and a diffraction pattern (diffraction grating) 10b having a desired shape formed on the metal foil. The diffraction pattern 10b has a predetermined grating direction. When visible light is irradiated from a specific angle, the hologram 10 reflects the diffracted light corresponding to the diffraction pattern 10b and displays a rainbow feature pattern.

  Conditions under which diffracted light appears from the hologram 10 to be inspected are determined by the direction and pitch of the diffraction pattern 10b of the hologram. As shown in FIG. 3, the incident light is the incident angle (elevation angle) θ1 and rotation angle φ1 optimized in the direction orthogonal to the diffraction pattern 10b (incident light in the direction Y perpendicular to the transport direction B or the transport direction B). When the hologram 10 is irradiated at an angle), regular reflection light appears at an angle θ1 from the diffraction pattern 10b, and diffracted light is observed between the incident angle and the regular reflection light angle.

  As shown in FIG. 4A, when viewed from the direction of arrow a in FIG. 3, when the incident light is irradiated onto the hologram 10 at an angle α1 obtained by combining the elevation angle θ1 and each rotation φ1, the diffraction pattern 10b. Therefore, specularly reflected light appears at an angle α1, and diffracted light is observed between the incident angle and the specularly reflected light angle. Similarly, as shown in FIG. 4B, when viewed from the direction of the arrow b in FIG. 3, when the incident light is irradiated onto the hologram 10 at an angle β1 obtained by combining the elevation angle θ1 and each rotation φ1, From the diffraction pattern 10b, specularly reflected light appears at an angle β1, and diffracted light is observed between the incident angle and the specularly reflected light angle.

  The support conveyance mechanism 14 is configured by, for example, a plurality of rollers 22 and a belt (not shown), and holds the card 12 in a predetermined position with no slack. The support conveyance mechanism 14 is also predetermined with respect to the optical fiber illumination device 16 and the imaging unit 20. It is relatively conveyed along the direction B.

  As shown in FIGS. 1 and 2, the optical fiber illuminating device 16 includes a light source 24, an optical fiber 26 formed by a bundle of a plurality of strands 26a, and a guide member that supports an output side end of the optical fiber. The light guide 28 is provided. As the light source 24, for example, a fluorescent tube or a halogen light source is used.

  As shown in FIGS. 1, 2, 5, and 6, the base end portion of the optical fiber 26 is optically connected to the light source 24, and the emission side end portion is supported by the light guide 28. The optical fiber 26 guides the light emitted from the light source 24 and emits it from the emission end. The light guide 28 is formed in a rectangular parallelepiped shape, for example, from aluminum, and has a flat emission surface 30. The light guide 28 is disposed above the card with the exit surface 30 facing the inspection surface 12a of the card 12 in parallel.

  The light guide 28 supporting the emission end of the optical fiber 26 is disposed at a predetermined angular position with respect to the card 12 and has a directivity optimized so that a diffraction image can be obtained by the diffraction pattern 10 b of the hologram 10. Illuminate the hologram with illumination light. That is, the light guide 28 has an angle α1 at which at least one diffraction pattern emits diffracted light with respect to the hologram 10 having the diffraction pattern 10b attached to the card 12, and the diffracted light enters the imaging unit 20. Placed in position.

  A plurality of strands 26a constituting the optical fiber are embedded in the light guide 28 at the exit side end of the optical fiber 26, and the exit end thereof is located on the exit surface 30 of the light guide. Each of the plurality of strands 26a is inclined with respect to the emission surface 30 by a predetermined angle θ1 not including 90 degrees. The inclination angle α1 of the strand 26a coincides with an angle obtained by synthesizing a specific incident angle (elevation angle) θ1 that produces reflected diffracted light from the hologram 10 to be inspected and the rotation angle φ1. Moreover, the some strand 26a is arrange | positioned along with the line form, for example, is located in a line along the direction orthogonal to the conveyance direction B of the card | curd 12.

  As shown in FIG. 7, a plurality of V-shaped grooves 31 are formed side by side in the light guide 28, and the plurality of strands 26 a are engaged with each other in the V-shaped grooves 31, at a predetermined angular position. Is positioned.

  The irradiation light irradiated on the card 12 from the emission end of the optical fiber 26 has a long and narrow irradiation region E extending in a direction perpendicular to the conveyance direction B of the card 12. The plurality of strands 26 a are arranged in a sufficient number and a sufficient length so that the irradiation region E is sufficiently wider than the width of the hologram 10. In the light guide 28, the strands 26a are not limited to one row, and may be arranged in a plurality of rows.

  As shown in FIG. 1, the imaging unit 20 is provided on the same surface side as the light guide 28 with respect to the card 12, and is disposed at a position for receiving reflected diffracted light from the hologram 10. As the imaging unit 20, for example, a line sensor is used, arranged along a direction orthogonal to the conveyance direction B of the card 12, and opposed to the irradiation region E of the optical fiber illumination device 16. As the imaging unit 20, a line point sensor, a monochrome point photo sensor, a color point photo sensor, a monochrome CCD sensor, a color CCD sensor, or the like can be used.

  As shown in FIGS. 1 and 2, the hologram inspection apparatus determines that the detected image obtained by the image processing unit and the image processing unit 25 that performs arithmetic processing on the detection data received and imaged by the imaging unit 20 and extracts features. Compared with reference data stored in the reference memory 32, the discrimination processing circuit 34 for discriminating the authenticity of the hologram 10 and the damage or loss of the hologram 10, the light source driver 36 for driving the light source 24, and the operation of the entire apparatus are controlled. The control part 40 to be provided is provided. The discrimination processing circuit 34 functions as a discrimination processing unit.

Next, an inspection operation of the hologram inspection apparatus configured as described above will be described.
As shown in FIGS. 1 and 2, the card 12 to which the hologram 10 having the diffraction pattern 10 b that is diffracted and reflected in the direction perpendicular to the incident light at the angle α <b> 1 is transported in the transport direction B by the support transport mechanism 14. . The light source 24 is turned on, and illumination light is irradiated from the exit end of the optical fiber 26 provided in the light guide 28 toward the hologram 10 on the card 12. When the hologram 10 on the card 12 passes through the irradiation region E, stable diffracted reflected light is reflected in the vertical direction from the entire diffraction pattern 10b in the hologram 10 by the light irradiated from the optical fiber inclined at the angle α1. To do. When the incident light with respect to the hologram 10 has an elevation angle θ1 and a rotation angle φ1, the diffracted light of the diffraction pattern 10b has the highest intensity and enters the imaging unit 20. The diffracted light from the hologram 10 is received by the imaging unit 20. The imaging unit 20 converts the received diffracted light into an electrical signal and inputs it to the image processing unit 25.

  The image processing unit 25 performs arithmetic processing on the detection data input from the imaging unit 20 and extracts features as a one-dimensional or two-dimensional image. When the diffraction pattern 10b on the hologram 10 has a defect due to chipping or peeling, the reflected diffracted light from the defective part is not detected. Further, when the hologram 10 is exhausted such that the surface state is deteriorated due to scratches, wrinkles, etc., there is no diffracted light or the intensity is weak. In addition, when there is no diffraction pattern 10b that should naturally exist, or when there is a different diffraction pattern, there is no diffracted reflected light. The determination processing circuit 34 compares the image data sent from the image processing unit 25 with the reference data stored in the determination reference memory 32 to determine whether the hologram 10 is damaged, missing, or true.

  According to the hologram inspection device and the optical fiber illuminating device configured as described above, the strands 26a of the optical fiber 26 are arranged in a line so as to be at a predetermined angle α1 with respect to the emission surface of the light guide 28, Further, the exit surface of the light guide is arranged in parallel with the inspection surface of the inspection medium. Thereby, the vertical distance between the exit end of each strand 26a and the inspection surface is constant for all the strands. Therefore, the spread and light intensity of light irradiated from the optical fiber 26 can be made uniform in the inspection visual field, that is, in the irradiation region E. Therefore, the entire hologram 10 can be uniformly irradiated with the light including the specific irradiation angle α1 emitted from the optical fiber 26. As a result, stable reflected diffracted light can be obtained from the entire area of the hologram 10. By using this reflected diffracted light, it is possible to detect defects, fatigue, and authenticity of the hologram with high accuracy and stability. .

Next, a hologram inspection apparatus according to the second embodiment will be described.
In the first embodiment, the apparatus for inspecting a hologram having one type of diffraction pattern has been described. However, according to the second embodiment, the hologram inspection apparatus can inspect a hologram having a plurality of types of diffraction patterns. It is configured.

  As shown in FIG. 8, the hologram 10 attached to the inspection medium diffracts and reflects diffraction light 10 diffracted and reflected on light incident at an elevation angle θ 1 and a rotation angle φ 1 and diffraction reflected on light incident at an elevation angle θ 2 and a rotation angle φ 2. In the case of having the pattern 10c, the optical fiber 26 of the optical fiber illumination device 16 has different angles α1 (an angle obtained by combining θ1 and φ1) and α2 (θ2 and φ2) corresponding to the diffraction patterns 10a and 10b, respectively. Are provided with a plurality of strands arranged to be inclined at an angle).

  That is, as shown in FIGS. 9 and 10, the plurality of first strands 26a constituting the optical fiber are embedded in the light guide 28 at the emission side end of the optical fiber 26, and the emission end of the optical fiber 26 is light. It is located on the exit surface 30 of the guide. The plurality of first strands 26a are respectively inclined with respect to the emission surface 30 by a predetermined angle α1 that does not include 90 degrees. The inclination angle α1 of the first strand 26a is equal to an angle obtained by combining a specific incident angle (elevation angle) θ1 that generates reflected diffracted light from the diffraction pattern 10b of the hologram 10 to be inspected and the rotation angle φ1. Moreover, the some strand 26a is arrange | positioned along with the line form, for example, is located in a line along the direction orthogonal to the conveyance direction B of the card | curd 12.

  At the exit end of the optical fiber 26, the plurality of second strands 26b constituting the optical fiber are embedded in the light guide 28, and the exit end is located on the exit surface 30 of the light guide. The plurality of second strands 26b are respectively inclined with respect to the emission surface 30 by a predetermined angle α2 that does not include 90 degrees. The inclination angle α2 of the second strand 26b coincides with an angle obtained by combining a specific incident angle (elevation angle) θ2 that produces reflected diffracted light from the diffraction pattern 10c of the hologram 10 to be inspected and the rotation angle φ2. The plurality of second strands 26b are arranged side by side in a line, for example, aligned in a line along a direction perpendicular to the conveyance direction B of the card 12. In addition, on the emission surface 30, the plurality of second strands 26 b are provided in parallel with each other at intervals from the first strand 26 b. In the present embodiment, the proximal end of the optical fiber 26 is connected to the common light source 24.

  The light guide 28 is disposed at a position where the emission surface 30 faces the inspection surface 12a of the card 12 as the inspection medium in parallel. In this way, by arranging the first strand 26a and the second strand 26b of the optical fiber in a line shape so that the angles α1 and α2 are with respect to the emission surface, and by arranging the light guide 28 as described above. Stable reflected diffracted light can be obtained for any of the diffraction patterns 10b and 10c of the hologram 10.

  When the hologram has a diffraction pattern n that is diffracted and reflected by a plurality of incident lights at an angle αn (n = 1, 2, 3,...), An angle αn with respect to the exit surface 30 is formed at the exit portion of the light guide 28. In this way, a plurality of optical fiber strands are arranged in a line so that the light guide exit surface 30 is parallel to the inspection surface on which the hologram is provided. Will stably reflect diffraction throughout.

  As shown in FIG. 10, a shutter mechanism 50 that opens and closes the exit end of the first strand 26 a and the exit end of the second strand 26 b is provided on the exit surface 30 side of the light guide 28. The shutter mechanism 50 is a first shutter 52a provided on the exit surface 30 so as to be slidable between a position where the exit end of the first strand 26a is closed and a position where the exit end is opened. 54a, a second shutter 52b provided on the exit surface 30 so as to be slidable between a position where the exit end of the second strand 26b is closed and a position where it is opened, and a drive unit 54b which drives the second shutter have. The drive units 54a and 54b are controlled by the control unit 40 described above. The shutter mechanism 50 constitutes an irradiation control means that allows only light irradiation from a strand arranged at any angle among a plurality of strands constituting the optical fiber.

  That is, when the hologram 10 has n diffraction patterns, for example, when reflected diffracted light is obtained from all the n diffraction patterns, both the first and second shutters 52a and 52b are switched to the open position. Then, light may be irradiated from all the optical fiber strands having an angle αn corresponding to the n diffraction patterns, here, the first strand 26a and the second strand 26b corresponding to the two diffraction patterns.

  In addition, when it is desired to obtain reflected diffracted light only from a specific diffraction pattern m among n diffraction patterns, light may be irradiated only from an optical fiber having a specific angle αm corresponding to the specific diffraction pattern. In this case, in the present embodiment, the shutter of the first or second strand corresponding to the diffraction pattern for which the reflected diffracted light is to be obtained is opened, and the other shutter is closed to restrict light emission.

In the second embodiment, the other configuration of the hologram inspection apparatus is the same as that of the first embodiment described above, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted.
According to the hologram inspection apparatus and the optical fiber illumination apparatus configured as described above, the same operational effects as those of the first embodiment can be obtained. In addition, even when a plurality of diffraction patterns are attached to the inspection medium, by using an optical fiber corresponding to the plurality of diffraction patterns, all the diffraction patterns can be accurately and stably defected, worn, and false. Can be detected.

  For example, when there are two diffraction patterns 10b and 10c, as shown in FIG. 11, irradiation control from the first and second strands of two angles α1 and α2 corresponding to the two diffraction patterns is performed. I do. That is, while irradiating light from the first strand 26a for the diffraction pattern 10b, the first shutter 52a is opened and the second shutter 52b is closed to emit light from the second strand 26b corresponding to the diffraction pattern 10c. Do not irradiate. In addition, while irradiating light from the second strand 26b for the diffraction pattern 10c, the second shutter 52b is opened and the first shutter 52a is closed to emit light from the first strand 26a corresponding to the diffraction pattern 10b. Do not irradiate. By repeating this cycle finely, the reflected diffracted light from the respective diffraction patterns 10b and 10c is incident on the imaging unit 20 alternately. Thereby, each diffraction pattern can be inspected independently.

  In the second embodiment described above, the optical fiber 26 is configured to receive light from the single light source 24. However, as shown in FIG. 12, the optical fiber 26 and the second strand composed of the first strand 26a. The optical fiber 26 made of 26b may be separately connected to two independent light sources.

In this case, the light source 24a is connected to the control unit 40 via the driver 36a, and the light source 24b is connected to the control unit 40 via the driver 36b. And it is good also as irradiation control which selectively irradiates light from a desired optical fiber by controlling on / off switching of the light sources 24a and 24b by the control part 40. For example, as shown in FIG. 11, the light source 24a and the light source 24b are alternately turned on and off by the control unit 40, and the reflected diffracted light from the diffraction patterns 10b and 10c is alternately obtained by repeating this cycle finely. be able to. As a result, as in the second embodiment described above, it is possible to detect defects, fatigue, and authenticity with high accuracy and stability for a hologram having a plurality of diffraction patterns.
The irradiation control method is not limited to the above, and any method that can control irradiation of n optical fibers may be used.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  For example, the inspection medium to which the hologram to be inspected is attached is not limited to the card described above, but may be a paper sheet such as a gift certificate or securities, or another inspection medium. In the above-described embodiment, the hologram is inspected while being transported to the inspection medium. However, the configuration is not limited to this, and the inspection medium hologram held at a predetermined position may be inspected. In the second embodiment, the configuration for inspecting a hologram having two types of diffraction patterns has been described. However, a hologram having three or more types of diffraction patterns can also be inspected. In this case, a plurality of strands inclined at an angle corresponding to the elevation angle peculiar to each diffraction pattern may be provided.

FIG. 1 is a perspective view showing a hologram inspection apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of the entire hologram inspection apparatus. FIG. 3 is a diagram showing incident light and reflected diffracted light with respect to the hologram. FIG. 4 is a diagram showing diffracted light and reflected light of a hologram. FIG. 5 is a side view showing a light guide of the hologram inspection apparatus and a plan view showing an irradiation region. FIG. 6 is a cross-sectional view of the light guide taken along line CC in FIG. FIG. 7 is a cross-sectional view of the light guide taken along line DD in FIG. FIG. 8 is a plan view showing a hologram having a plurality of diffraction patterns. FIG. 9 is a side view showing a light guide of a hologram inspection apparatus according to the second embodiment of the present invention. FIG. 10 is a plan view showing an exit surface side of a light guide of the hologram inspection apparatus according to the second embodiment. FIG. 11 is a timing chart showing irradiation control of emitted light. FIG. 12 is a view showing an optical fiber lighting device according to another embodiment of the present invention.

Explanation of symbols

10 ... Hologram, 10b, 10c ... Diffraction pattern, 12 ... Card,
12a ... inspection surface, 14 ... support and transport mechanism, 16 ... optical fiber illuminator, 20 ... imaging unit,
24, 24a, 24b ... light source, 26 ... optical fiber, 26a ... strand, 26b ... second strand,
28 ... light guide, 30 ... light exit surface, 25 ... image processing unit, 32 ... determination reference memory,
34 ... determination processing circuit, 40 ... control unit, 50 ... shutter mechanism,
52a ... 1st shutter, 52b ... 2nd shutter

Claims (9)

An optical fiber illumination device for illuminating an inspection surface,
A light source;
An optical fiber that is formed of a plurality of strands and guides light from the light source and emits the light from an emission end;
A guide member that supports the output side end of the optical fiber and has an output surface facing the inspection surface in parallel.
At the emission side end of the optical fiber, the plurality of strands are arranged side by side with a predetermined angle not including 90 degrees with respect to the exit surface of the guide member, and the exit ends of the plurality of strands Is an optical fiber illuminating device located on the exit surface. An optical fiber illumination device for illuminating an inspection surface,
A light source;
A plurality of optical fibers each of which is formed of a plurality of strands and guides light from the light source and exits from the exit end;
A guide member that supports the emission side end of the plurality of optical fibers and has an emission surface facing the inspection surface in parallel.
At the output side end of each optical fiber, the plurality of strands do not include 90 degrees with respect to the exit surface of the guide member, and are inclined at a predetermined angle different from the strands of other optical fibers. The optical fiber illuminating device which is arrange | positioned along with and the output end of these strands is located in the said output surface.   The optical fiber illuminating device according to claim 1, wherein the emission ends of the plurality of strands of the optical fiber are arranged in a line on the emission surface.   The optical fiber illuminating device according to claim 2, further comprising an irradiation control unit that allows only light irradiation from an optical fiber having a desired angle among the plurality of optical fibers.   The optical fiber illuminating apparatus according to claim 4, wherein the irradiation control unit includes a shutter mechanism that opens and closes an emission end of each of the plurality of optical fibers.   5. The light source according to claim 4, wherein the light source includes a plurality of independent light sources respectively connected to the plurality of optical fibers, and the irradiation control unit includes a control unit that switches on and off the plurality of light sources. Optical fiber lighting device. A hologram inspection apparatus that inspects a hologram having a diffraction pattern that is diffracted and reflected in a certain direction with respect to light incident at a specific incident angle,
A support mechanism for supporting the inspection medium with the hologram attached thereto;
An exit surface disposed in parallel to the inspection medium, and an optical fiber having an exit end disposed at an angle with respect to the exit surface by an angle corresponding to the specific incident angle; The optical fiber illumination device according to any one of claims 1 to 6, wherein the hologram is irradiated with light;
An imaging unit for imaging diffracted light from the hologram;
An image processing unit that performs image processing on an image captured by the imaging unit;
A determination processing unit for performing hologram defect, exhaustion, authenticity determination from the processed image,
A hologram inspection apparatus comprising:   The hologram inspection apparatus according to claim 7, wherein the imaging unit includes a line image sensor.   The hologram inspection apparatus according to claim 7, further comprising a transport mechanism that moves the inspection medium relative to the optical fiber illumination device and the imaging unit.

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