WO2013042348A1 - Dispositif de lecture - Google Patents

Dispositif de lecture Download PDF

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Publication number
WO2013042348A1
WO2013042348A1 PCT/JP2012/005927 JP2012005927W WO2013042348A1 WO 2013042348 A1 WO2013042348 A1 WO 2013042348A1 JP 2012005927 W JP2012005927 W JP 2012005927W WO 2013042348 A1 WO2013042348 A1 WO 2013042348A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
light emitting
light guide
emitting element
reading
Prior art date
Application number
PCT/JP2012/005927
Other languages
English (en)
Japanese (ja)
Inventor
崇史 真田
伸浩 土橋
川野　裕三
Original Assignee
パナソニック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2011206046A external-priority patent/JP2013069484A/ja
Priority claimed from JP2011220052A external-priority patent/JP2013081075A/ja
Priority claimed from JP2011220047A external-priority patent/JP2013081074A/ja
Priority claimed from JP2011220044A external-priority patent/JP2013081073A/ja
Application filed by パナソニック株式会社 filed Critical パナソニック株式会社
Publication of WO2013042348A1 publication Critical patent/WO2013042348A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/024—Details of scanning heads ; Means for illuminating the original
    • H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
    • H04N1/02815—Means for illuminating the original, not specific to a particular type of pick-up head
    • H04N1/02845—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array
    • H04N1/0285—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array in combination with at least one reflector which is in fixed relation to the light source
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/024—Details of scanning heads ; Means for illuminating the original
    • H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
    • H04N1/02815—Means for illuminating the original, not specific to a particular type of pick-up head
    • H04N1/02845—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array
    • H04N1/02855—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array in combination with a light guide, e.g. optical fibre, glass plate
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/024—Details of scanning heads ; Means for illuminating the original
    • H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
    • H04N1/02815—Means for illuminating the original, not specific to a particular type of pick-up head
    • H04N1/02845—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array
    • H04N1/02865—Means for illuminating the original, not specific to a particular type of pick-up head using an elongated light source, e.g. tubular lamp, LED array using an array of light sources or a combination of such arrays, e.g. an LED bar
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/024—Details of scanning heads ; Means for illuminating the original
    • H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
    • H04N1/03—Details of scanning heads ; Means for illuminating the original for picture information pick-up with photodetectors arranged in a substantially linear array
    • H04N1/0301—Details of scanning heads ; Means for illuminating the original for picture information pick-up with photodetectors arranged in a substantially linear array using a bent optical path between the scanned line and the photodetector array, e.g. a folded optical path
    • H04N1/0303—Details of scanning heads ; Means for illuminating the original for picture information pick-up with photodetectors arranged in a substantially linear array using a bent optical path between the scanned line and the photodetector array, e.g. a folded optical path with the scanned line and the photodetector array lying in non-parallel planes

Definitions

  • the present invention relates to a reading apparatus using an imaging apparatus that images a surface to be read illuminated by an illumination apparatus including a light emitting element and a light guide.
  • a reading device such as a copying machine or a scanner
  • an object to be read is placed on a platen made of a glass plate or the like, and an image pickup device (camera) is irradiated by illuminating the surface to be read from below the platen with a lighting device.
  • an illumination device of such a reading device there is one that uses an LED as a light source.
  • an LED is provided at one end in a longitudinal direction of a rod-shaped light guide and a light reflecting portion that extends in the longitudinal direction of the light guide
  • a linear light source that guides the light from the LED into the light guide and emits it in a direction perpendicular to the longitudinal direction by the light reflecting portion, there is one that irradiates the surface to be read (for example, see Patent Document 1). ).
  • the conventional reading apparatus uses a so-called line sensor as an image reading means, and linear light is emitted from the light guide correspondingly.
  • the reading target is the longitudinal direction of the linear light source (mainly The image is moved in a direction (sub-scanning direction) orthogonal to the (scanning direction).
  • a reading device in which the entire surface of the document table is imaged by a camera (imaging device) at a time.
  • a reading apparatus it is necessary to irradiate the entire surface of the document table.
  • the illumination device in the conventional reading device a plurality of light reflecting portions as light sources are provided apart from each other in the sub-scanning direction in order to widen the irradiation range in the sub-scanning direction.
  • the irradiation range with respect to the sub-scanning direction is narrow.
  • a large number of light guides are arranged side by side, which increases the size of the entire illumination device.
  • the layout of the built-in parts including the imaging device will be restricted if the illumination device becomes large.
  • the light emitted from the light guide is reflected on the back side of the document table made of glass or the like (the surface opposite to the surface on which the object to be read is placed) It may be reflected by a mirror installed for compactness to become stray light, and the stray light may directly enter the imaging apparatus.
  • stray light enters the image pickup device directly, there is a problem that the accumulated charge is saturated in each pixel of the image pickup device (image sensor), and a whiteout phenomenon occurs in an image.
  • the present invention has been devised to solve such problems of the prior art, and the main object of the present invention is to provide an imaging device in a reading apparatus having an illumination device having a light guide from the light guide.
  • An object of the present invention is to provide a reading apparatus configured so that light does not enter directly.
  • the reading device of the present invention includes a transparent reading object mounting unit on which a reading object is mounted, an illumination device that illuminates the reading object mounted on the reading object mounting unit, and the illumination
  • a reading apparatus comprising: an imaging device that images the reading object illuminated by the apparatus, wherein the lighting device guides light from the light emitting element and the light emitting element toward the reading object placing unit.
  • a light guide having a rod shape, the light guide having an emission surface on a side facing the reading object mounting portion, and an optical axis of the light emitting element when the light guide is viewed from the longitudinal direction.
  • the outer shape line serving as the emission surface is asymmetric with respect to the optical axis.
  • the outline forming the curved emission surface is formed asymmetrically, and the emission direction of light from the emission surface is taken as the optical axis of the light emitting element. It can be asymmetrical.
  • the exit surface is a cylindrical lens, there is a possibility that light that is reflected by the reflector and becomes stray light in the light emitted from the light guide body is generated. Since the radius of the exit surface is reduced and refracted greatly, the light traveling from the exit surface of the light guide toward the reflector can be removed from the reflector, so stray light enters the imaging device and the image It is possible to prevent the occurrence of overexposure.
  • FIG. 1 is an overall perspective view of a reading apparatus to which the present invention is applied.
  • Side view showing the main part inside the reader (A) is a principal part perspective view of an upper light guide, (b) is a principal part perspective view of a lower light guide.
  • Front view of illumination board showing the arrangement of LED elements Explanatory drawing corresponding to FIG.
  • a transparent reading object placing unit on which a reading object is placed, and the reading object placed on the reading object placing unit.
  • a reading device comprising: an illuminating device that illuminates; and an imaging device that images the reading object illuminated by the illuminating device, wherein the illuminating device includes a light emitting element and light from the light emitting element to be read.
  • a rod-shaped light guide that guides toward the object placement unit, the light guide has an emission surface on a side facing the reading object placement unit, and the light guide is viewed from the longitudinal direction.
  • the outline serving as the emission surface is asymmetric with respect to the optical axis.
  • the outer shape line forming the curved emission surface is formed asymmetrically, and the emission direction of the light from the emission surface is set with respect to the optical axis of the light emitting element.
  • the exit surface is a cylindrical lens, there is a possibility that light that is reflected by the reflector and becomes stray light in the light emitted from the light guide body is generated. Since the radius of the exit surface is reduced and refracted greatly, the light traveling from the exit surface of the light guide to the reflecting mirror can be removed from the reflecting mirror, so that stray light enters the imaging device directly. It is possible to prevent overexposure in the video.
  • a reflecting mirror is provided for reflecting an image of the reading object placed on the reading object placing portion toward the imaging device. The configuration.
  • the image of the reading object placed on the reading object placing portion can be folded back by the reflecting mirror and photographed by the imaging device, and the reading device can be made compact.
  • the illuminating device and the imaging device are disposed on the opposite side of the reflecting mirror, and the outline of the emission surface is formed by combining a plurality of arcs.
  • the radius of each of the plurality of arcs closer to the reflecting mirror is relatively small.
  • the emitted light when the emitted light is emitted from the illuminating device in a fan shape, the light emitted from the portion near the reflecting mirror on the emitting surface of the light guide is reflected by the reflecting mirror toward the reading object mounting portion.
  • the light is reflected by the reading object placement unit and directly travels to the imaging device via the reflecting mirror.
  • the radius of the arc on the reflecting mirror side of the exit surface is reduced, the light traveling to the reflecting mirror is generated. Can be bent toward the reading object mounting portion side, so that the outgoing light from the light guide toward the reflecting mirror can be eliminated, and the light from the illuminating device passes through the reflecting mirror and the imaging device Can be prevented from entering directly.
  • the light emitting element and the light guide are disposed at least at two positions that are far from the reading object placing portion,
  • An average radius of the plurality of arcs forming the outline of the light guide is configured to be smaller than an average radius of the plurality of arcs forming the outline of the light guide at the close position.
  • the light emitting element and the light guide are disposed at two positions that are far from the reading object placing unit, and the average radius of the light guide at a position far from the reading object placing unit is set.
  • the diameter By making the diameter small, it is possible to narrow the light emitted from the light guide at a distant position, and it is possible to prevent the irradiation range from being excessively widened at the reading object placing portion, and it is arranged at two near and far positions. It is possible to perform substantially uniform irradiation with each light guide provided.
  • the light emitting element includes a plurality of light emitting elements arranged side by side, and the light guide transmits light from the light emitting elements to the reading object.
  • the plurality of light emitting elements further includes a first light emitting element and a second light emitting element having a light distribution different from that of the first light distributing element.
  • the light guide has a refractive index that diffuses the light from the first light emitting element with a substantially uniform illuminance over the entire area of the reading object mounting portion corresponding to the light distribution of the first light emitting element.
  • the second light emitting element is formed so as to be displaced in a direction perpendicular to the optical axis of the light emitting element with respect to the first light emitting element when viewed from the longitudinal direction of the light guide.
  • the second light emitting element having a light distribution different from that of the first light emitting element is In the case of the same position as the first light emitting element when viewed from the longitudinal direction of the light guide, the light distribution of the second light emitting element is not diffused with substantially uniform illuminance, but the second light emitting element is By being disposed in a shifted manner, the light from the second light emitting element passes through a different part of the light guide from the first light emitting element, and can be diffused differently from the light of the first light emitting element. . Accordingly, by appropriately setting the position of the second light emitting element to be shifted according to the light distribution, the second light emitting element can be irradiated with substantially uniform illuminance.
  • the light exit surface of the light guide is formed with a portion having a large radius and a small radius when viewed from the longitudinal direction of the light guide.
  • the second light emitting element has a light distribution that is wider than the light distribution of the first light emitting element, and the first light emitting element is seen from the longitudinal direction of the light guide.
  • it is set as the structure which has shifted
  • the light from the second light emitting element is emitted from the small radius portion of the light emitting surface of the light guide, so Of the emitted light can be suppressed.
  • the wavelength of the second light emitting element is longer than the wavelength of the first light emitting element.
  • the wavelength of the light of the second light emitting element is longer than that of the first light emitting element, the light from the second light emitting element is difficult to be refracted, but the light from the second light emitting element is refracted by the refractive index of the light guide. Since the light can be largely refracted by being emitted through a large portion, the occurrence of uneven illuminance can be suppressed by the arrangement according to the refractive index.
  • the illumination device has a light source in which a plurality of the light emitting elements are arranged in a straight line, and the light from the light source is incident on the light guide.
  • the light guide has an entrance surface and an exit surface that emits light incident on the entrance surface, and is formed in an elongated shape so as to extend in the direction in which the plurality of light emitting elements are arranged. At least one end in the longitudinal direction of the shape has a light emission direction changing portion that changes the light from the light emitting element in a direction different from the optical axis perpendicular to the incident surface.
  • a long light guide is formed in the direction in which the plurality of light emitting elements are arranged, and light is emitted from the light emitting elements disposed in the vicinity of the one end at least at one end in the longitudinal direction of the light guide. Since the light emission direction changing unit for changing the direction is provided, a part of the emitted light from the light guide can be emitted in different directions.
  • the second emission surface for emitting the light whose direction has been changed is inclined rearwardly with respect to the emission surface in the light emission direction changing portion. It is set as the structure provided in.
  • the emitted light whose direction has been changed by the light emitting direction changing unit with respect to the range irradiated by the emitted light emitted from the emitting surface other than the light emitting direction changing unit of the light guide is the second emitting surface. Since the light is emitted from and irradiated, a single light guide can obtain an emission state in different directions.
  • a tenth aspect of the invention is the light guide according to the ninth aspect of the invention, wherein the light emitting direction changing portion changes the direction of light incident from the incident surface to a direction of emitting from the second emitting surface. It is set as the structure which has a reflective surface which consists of a longitudinal direction end surface.
  • the direction of light incident from the incident surface near one end can be changed with a simple structure in which a reflecting surface is formed on the end surface in the longitudinal direction of the light guide.
  • the eleventh aspect of the invention is the ninth or tenth aspect of the invention, wherein the exit surface is formed on a cylindrical lens.
  • the emitted light emitted from the emission surface by the cylindrical lens can be made substantially uniform in the short direction of the light guide.
  • the light traveling from the light emitting element toward the outer side in the longitudinal direction of the light from the light emitting element is moved closer to the center.
  • a prism surface for changing the direction is provided.
  • the outgoing light is emitted with a spread with respect to the optical axis at the center of the light emitting element
  • the direction of the light traveling outward in the longitudinal direction of the light guide to the center of the light guide is changed by the prism surface.
  • the light emitted from the light exit surface of the light guide can be irradiated substantially uniformly in the longitudinal direction of the light guide.
  • a thirteenth aspect of the present invention is the method according to any one of the eighth to twelfth aspects, further comprising control means for controlling light emission of the plurality of light emitting elements, wherein the control means is disposed in the vicinity of the one end.
  • control means for controlling light emission of the plurality of light emitting elements, wherein the control means is disposed in the vicinity of the one end.
  • the emission direction due to light emission in each mode changes by controlling the light emission by switching the mode
  • the direction is changed when determining what changes in appearance due to the difference in the angle of light hitting. It is possible to cope with this by simply switching the mode on the lighting device side.
  • the light source and the light guide are arranged in a plurality of parallel rows, and the plurality of rows of the light guides.
  • Each of the light emission direction changing sections is configured such that the emission directions of the emitted lights emitted from the respective light emission direction changing sections are different in each of the plurality of rows.
  • the whole light can be irradiated by changing the emission direction by the emission direction changing unit of each of the plurality of light guides to compensate for the portions that cannot be irradiated by each. Can do.
  • the plurality of light emitting elements include any one of a white light element, an ultraviolet light element, and an infrared light element. To do.
  • the transparent object placing unit irradiated with the illumination device from below and on which the reading object is placed, and the read object And an imaging device that images the surface.
  • the illumination device when the object to be read is visually determined to be provided on the surface to be read depending on the irradiation angle, the illumination device according to each of the inventions described above is used for the object placement unit.
  • the illumination device By imaging the surface to be read of the placed reading object with an imaging device and projecting it on the screen, it is possible to easily irradiate the surface to be read with the irradiation angle changed, and the captured image is displayed on the screen. Easy to judge.
  • a transparent reading object mounting unit on which a reading object is mounted, an illumination device that illuminates the reading object mounted on the reading object mounting unit,
  • a reading device comprising: an imaging device that images the reading object illuminated by an illuminating device, wherein the lighting device directs light from the light emitting element and the light from the light emitting element toward the reading object mounting portion.
  • a rod-shaped light guide for guiding, and the light guide has a light emitting direction from the light emitting element toward an end side of the read target object placement part, at a central portion of the read target object placement part. The optical path refracting part is refracted on the side.
  • the light path refraction that refracts light from the light emitting element toward the portion near the end of the reading object placing portion toward the center side. Since the portion is provided on the light guide, it is possible to irradiate the portion closer to the end of the reading object placing portion with higher illuminance. As a result, the peripheral portion is irradiated with high illuminance in response to a decrease in the amount of light in the peripheral portion of the image screen due to the influence of the lens, so that the entire surface of the reading object placing portion is imaged to have substantially uniform brightness. be able to.
  • an eighteenth aspect of the invention is that in the seventeenth aspect of the invention, the optical path refracting portion is formed by an inclined surface that is concave or convex on the incident surface of the light guide.
  • the light incident on the light path refracting part can be refracted by the light path refracting part provided on the incident surface of the light guide, the light can be directed in any direction by simply changing the form of the light path refracting part. Can be refracted.
  • At least two rows of the light guide and the light emitting element are provided at positions that are in a perspective relationship with respect to the reading object placing portion.
  • a refractive index of the optical path refracting portion provided in the light guide in a row close to the reading object placement portion is configured to be larger than that in a far row.
  • the refractive index of the optical path refracting part provided on the light guide near the reading object mounting part is increased, the emitted light can be spread widely with a large refractive index. Since it is close to the portion, it is possible to prevent the irradiation range of the light emitted from the light guide from becoming narrow.
  • the light guide emits light from the light emitting element toward the central portion of the reading object placing portion. And a second optical path refracting portion to be diffused.
  • FIG. 1 is an overall perspective view showing an example of a reading apparatus according to the present invention.
  • the reading device 1 has a substantially rectangular parallelepiped housing 2 having a hollow inside and is used on a desk or the like. In the following description, the vertical direction is assumed to be in a state where the reader 1 is placed on a desk.
  • FIG. 2 is a side view showing an essential part inside the reading apparatus according to the present invention.
  • a glass plate 3 as a reading object placing portion is provided on the upper surface of the housing 2 over substantially the entire surface.
  • a passport 4 as an object to be read is placed on the upper surface of the glass plate 3 with the read surface 4 a facing the glass plate 3.
  • a main substrate 5 is disposed in the vicinity of the bottom surface of the housing 2 below the glass plate 3.
  • the main board 5 is provided with a control circuit, a drive circuit, and the like (not shown) of the reading device 1.
  • An illuminating substrate 6 is disposed at an upper position on one end side of the main substrate 5 and is inclined upward so as to face the back surface of the glass plate 3.
  • the support structure for fixing the substrates 5 and 6 to the housing 2 may be a known screwing structure and is not shown.
  • the LED board 7 in which a plurality of LED elements as light emitting elements are arranged is arranged in the upper and lower rows on the illumination board 6, and as shown in FIG. 3, each LED row 7 is arranged.
  • Each of the rod-shaped light guides (upper light guide 8 and lower light guide 9. These are collectively referred to as “light guides 8 and 9” hereinafter so as to cover the emission surfaces of the respective LED elements.
  • the lighting device is configured in this manner.
  • resin spacers 16 each having an opening corresponding to each LED element of the LED array 7 arranged on the illumination board 6 are arranged. ing.
  • the wall surface of the opening provided in the spacer 16 has a tapered shape spreading in the light emitting direction of the LED element, and the light emitted from the LED element is reflected by this wall surface and efficiently guided into the light guides 8 and 9. It is burned.
  • FIG. 3A is a perspective view of a main part of the upper light guide 8, and FIG. 3B is a perspective view of a main part of the lower light guide 9.
  • the upper light guide 8 has a shape in which the left and right sides thereof are line-symmetrical at the central portion in the longitudinal direction.
  • 3 (b) showing the front view of the lower light guide 9 as well, which is screwed to the illumination board 6 with the spacers 16 sandwiched between the mounting holes 8a provided at the locations.
  • the illumination board 6 has a shape that is line symmetric as shown in FIG. 5 and has spacers 16 sandwiched between the mounting holes 9a provided at three locations in the longitudinal center and both ends. (Each screw is not shown).
  • the light guides 8 and 9 are each configured as a single body.
  • the LED array 7 is disposed at a position corresponding to the central portion in the longitudinal direction of each light guide 8 and 9 on the illumination board 6.
  • the light guides 8 and 9 may be divided at the central portion in the longitudinal direction. In this way, electrical components can be arranged on the illumination board 6 corresponding to the divided portion, so that the mounting efficiency of the illumination board 6 is improved.
  • an image of the surface to be read 4 a of the passport 4 placed on the upper surface of the glass plate 3 is imaged at the center in the longitudinal direction of the upper light guide 8 and on the upper side thereof.
  • a camera 13 as an imaging device is provided, and a reflecting mirror 14 for bending the optical path of the image of the read surface 4 a toward the camera 13 is provided at a position facing the camera 13. The reason for bending the optical path in this manner is effective for making the reading device 1 compact.
  • FIG. 4 is a front view of an illumination board showing the arrangement of LED elements according to the present invention.
  • FIG. 4 shows the arrangement of the LED elements of each LED row 7 arranged on the illumination board 6.
  • two ultraviolet LED elements UV 1 and UV 2 for ultraviolet rays, infrared rays are provided from the center to the right side along the upper reference line L 1 in the longitudinal direction of the upper light guide 8.
  • Infrared LED element IR1, white LED element WL1 for visible light, two ultraviolet LED elements UV3 and UV4, infrared LED element IR2, and white LED element WL2 are arranged in this order.
  • each LED element of the LED row 7 of the left side part from the center part of the figure of the upper side light guide 8 is arrange
  • UV6 / UV7 / UV8, infrared LED element IR3, white LED element WL3, ultraviolet LED element UV9, and white LED element WL4 are arranged in this order. Further, the LED elements of the LED row 7 in the left part from the center of the lower light guide 9 in the figure are also arranged symmetrically with respect to the right side.
  • the glass plate 3 is formed by white LED elements WL1 and WL3 on the center side. It is desirable to illuminate the entire (original surface) as uniformly as possible. In this case, unevenness can be reduced if the light emitted from the white LED elements WL1 and WL3 is sufficiently diffused by the light guides 8 and 9.
  • FIG. 5 is an explanatory view corresponding to FIG. 2 showing the optical path of the outgoing light
  • FIG. 6A is a cross-sectional view showing the outer shape of the outgoing face of the upper light guide 8 in the present invention
  • FIG. 3 is a cross-sectional view showing an outer shape of an emission surface of the light body 9.
  • the diffusion range can be simply increased by adjusting the curvature of the exit surfaces 8d and 9d of the light guides 8 and 9,
  • the diffusion becomes excessive that is, when the outgoing direction of the outgoing light from the outgoing faces 8d and 9d is excessively widened, as shown by the broken line arrow Lm1 and the two-dot chain line arrow Lm2 in FIG.
  • Part of the emitted light travels toward the reflecting mirror 14, and light that is reflected by the reflecting mirror 14 and then travels toward the glass plate 3 is generated.
  • Such light Lm1 and Lm2 may be reflected by the lower surface 3a of the glass plate 3 and reflected by the reflecting mirror 14 to be directed to the camera 13 in some cases.
  • the stray light due to the reflection may be avoided by adjusting the positional relationship among the light guides 8 and 9, the camera 13, and the reflecting mirror 14.
  • the design of the positional relationship is complicated.
  • the present invention corresponds by the shape of the exit surfaces 8d and 9d of the light guides 8 and 9.
  • the outline forming the exit surface 8d in the cross section viewed from the longitudinal direction of the upper light guide 8 is formed by an arc having a radius Ra in the range A on the reflecting mirror 14 side.
  • an arc having a radius Rb is formed in the range B on the glass plate 3 side.
  • the radius Ra is smaller than the radius Rb and is asymmetric with respect to the optical axis CL of the white LED element WL1.
  • the outer shape forming the exit surface 9d in the cross section viewed from the longitudinal direction of the lower light guide 9 is an arc having a radius Rc in the range C on the reflecting mirror 14 side, as shown in FIG. 6B.
  • an arc having a radius Rd is formed in the range D on the glass plate 3 side.
  • the radius Rc is smaller than the radius Rd and is asymmetric with respect to the optical axis CL of the white LED element WL3.
  • the emission directions of the light Lw1 and Lw2 (solid arrows in FIG. 5) that are closest to the reflecting mirror 14 of the emitted light emitted from the ranges A and C of the emission surfaces 8d and 9d of the light guides 8 and 9 Can be tilted and emitted so as to return to the light Lm1 and Lm2 by angles ⁇ 1 and ⁇ 2, respectively, inside the light guides 8 and 9.
  • the sizes of the angles ⁇ 1 and ⁇ 2 can be arbitrarily changed according to the sizes of the radii Ra and Rc, and the emission directions of the lights Lw1 and Lw2 can be further away from the reflecting mirror 14 by making the diameters smaller. . In this way, it is possible to eliminate the light that enters the camera 13 due to the reflection as described above, and it is possible to prevent the image of the camera 13 from being overexposed.
  • the radius Ra / Rc is set so as to secure the emission angle to be the light Lw1 / Lw2, and the ranges A / C and the radii Rb / Rd and the radii Rb / Rd and the glass plate 3 have uniform illuminance.
  • Each range B and D is set. In this way, by combining arc surfaces having different curvatures, the light (Lm1 and Lm2) that directly hits the reflecting mirror 14 after being emitted from the exit surfaces 8d and 9d of the light guides 8 and 9 is eliminated. 3 can ensure a uniform illuminance distribution.
  • the exit surface 8d (9d) is formed with two different radii Ra ⁇ Rb (Rc ⁇ Rd).
  • the exit surface 8d (9d) is a combination of three or more different radii, that is, a non-single arc surface.
  • the surface 8d (9d) may be formed. In any case, it is preferable to form a curved surface that smoothly changes from one radius to the other at the boundary between different radii.
  • each of the exit surfaces 8d and 9d for example, when the respective average radii are obtained from the weighted average of the radii Ra and Rb (Rc and Rd) using the ratio A: B (C: D) of each range,
  • the average radius of the exit surface 9d of the lower light guide 9 is made smaller than the average radius of the exit surface 8d of the upper light guide 8. Since the lower light guide 9 is farther than the glass plate 3 than the upper light guide 8, the irradiation range from the lower light guide 9 is further expanded in the case of the same radius, as described above.
  • the irradiation range can be narrowed, and even if there is a difference in perspective with respect to the glass plate 3 between the light guides 8 and 9, the illuminance It is possible to prevent non-uniform illuminance distribution due to the spread of the range.
  • a shift is made in a direction orthogonal to the reference lines L 1 and L 2 on the surface of the illumination substrate 6.
  • the reference line L1 is orthogonal to the optical axis CL of the white LED element WL1 as the first light emitting element
  • the reference line L2 is orthogonal to the optical axis CL of the white LED element WL2 as the first light emitting element.
  • the extending direction of the reference line L1 (L2) as the arrangement direction of the LED elements WL, IR, and UV is the X direction, and the reference line L1 (L2) is viewed from the arrangement direction of the LED elements WL, IR, and UV.
  • a direction perpendicular to the surface and along the surface of the illumination substrate 6 is defined as a Y direction.
  • d is an arbitrary shift amount.
  • the white LED element WL1 on the center side is positioned on the line, and the infrared LED element IR1 as the second light emitting element provided next to the white LED element WL1 is shifted downward ( ⁇ d in FIG. 4), The infrared LED element IR2 is positioned on the line.
  • the four ultraviolet LED elements UV1 to UV4 are shifted in different sizes on the lower side.
  • the white LED element WL3 on the center side is positioned on the line, and the adjacent infrared LED element IR3 is also Located on the line.
  • the five ultraviolet LED elements UV5 to UV9 are shifted in different sizes on the lower side.
  • the LED elements are arranged in this way even when white light, infrared light, and ultraviolet light having different light distribution characteristics are used by using the same light guides 8 and 9 (emission surfaces 8d and 9d). This is to enable the glass plate 3 to be irradiated with a substantially uniform illuminance distribution, and each shift amount is set to an appropriate value so as to obtain a substantially uniform illuminance distribution.
  • the outermost white LED elements WL2 and WL4 are arranged in correspondence with the protrusions 11 and 12 provided at both ends in the longitudinal direction of the light guides 8 and 9, as shown in FIG. ing.
  • the protrusions 11 and 12 are provided with rear surface portions 11a and 12a on the outer side in the longitudinal direction of the light guides 8 and 9, and the second emission surfaces 11b and 12b in a rearward inclined state on the inner side in the longitudinal direction of the light guides 8 and 9. Is provided.
  • the light is emitted obliquely toward. Accordingly, it is possible to cope with authenticity determination of a passport or the like to which OVI (Optically Variable Ink) whose color changes according to the difference in irradiation angle is applied.
  • OVI Optically Variable Ink
  • the white LED elements WL1 and WL3 are arranged so that the illuminance distribution of white light on the glass plate 3 is substantially uniform.
  • the light guides 8 and 9 have a kamaboko-shaped cross section extending along the reference lines L1 and L2, and the illuminance distribution is uniformized with respect to the bending direction (Y direction) of the exit surfaces 8a and 9a as described above.
  • the illuminance distribution in the extending direction of the reference lines L1 and L2 cannot be adjusted by the curvature of the exit surfaces 8d and 9d. Therefore, according to the difference in the spread of the emitted light depending on the distance of the light guides 8 and 9 with respect to the glass plate 3, in the present embodiment, the white LED element WL1 corresponding to the upper light guide 8 as shown in FIG. Is arranged closer to the center of the glass plate 3, and the white LED element WL3 corresponding to the lower light guide 9 is arranged outside the white LED element WL1.
  • FIG. 7 is a characteristic diagram showing the light distribution of the white LED element and the infrared LED element of the present invention in a graph.
  • the light distribution characteristic of the infrared LED element IR is narrower than the light distribution characteristic (two-dot chain line) of the white LED element WL as shown by the solid line in FIG. 7, and the wavelength of the infrared light is visible light (white light). Therefore, infrared light is less likely to be refracted at the medium boundary than white light. Therefore, when the same lens (prism) is used, infrared light can be irradiated only in a narrow range with respect to white light.
  • both the curved direction and the linear direction (longitudinal direction of the light guides 8 and 9) of the output surfaces 8d and 9d of the light guides 8 and 9 are targets.
  • the exit surfaces 8d and 9d of the light guides 8 and 9 are formed in a shape that prioritizes the uniform illumination distribution by the white LED elements WL, and each of the light guides 8 and 9 is used.
  • the arrangement of the infrared LED elements IR1 to IR3 will be described below.
  • the infrared LED element IR is arranged next to the white LED element WL so as to be basically at the same position as the white LED element WL.
  • the center side of the glass plate 3 is irradiated by the infrared LED element IR1 inside the light guide 8 in the longitudinal direction, and the side edge side of the glass plate 3 is irradiated by the infrared LED element IR2 outside the longitudinal direction of the light guide 8. Irradiate.
  • the outer infrared LED element IR2 of the upper light guide 8 is disposed on the reference line L1, but the inner infrared LED element IR1 is located below the reference line L1. A fixed amount is shifted.
  • FIG. 8 is an explanatory view showing a state in which the position of the infrared LED element is shifted.
  • the emission direction of the emitted light from the upper light guide 8 by the infrared LED elements IR1 and IR2 arranged in a shifted manner is shown in FIG.
  • the solid line indicates the inner infrared LED element IR1 shifted downward from the reference line L1 (that is, the side where the radius of the emission surface 8d is small), and the two-dot chain line indicates the outer side located on the reference line L1.
  • the infrared LED element IR2 is shown, and each outgoing light is indicated by an arrow.
  • the upper side of the emitted light from both infrared LED elements IR1 and IR2 is emitted in substantially the same direction, but the lower side of each emitted light is the infrared LED element IR2 arranged on the reference line L1. Is spread out downward and emitted.
  • the radius In the upper range (radius Rb) of the exit surface 8d, the radius is larger than the lower range (Rb> Ra) and faces the glass plate 3 as described above.
  • the change in the emission direction at 8d is not so great.
  • the two infrared LED elements IR1 and IR2 are in a relative translational relationship with respect to the incident surface 8b, and the optical axes of the emitted lights from the infrared LED elements IR1 and IR2 are parallel to each other.
  • FIG. 9 is an explanatory diagram showing the distribution of the irradiation range by the infrared LED element.
  • the irradiation ranges S1 and S2 on the glass plate 3 by the infrared LED elements IR1 and IR2 will be described with reference to FIG.
  • an irradiation range is demonstrated using the vertical and horizontal direction in the figure of the glass plate 3.
  • the irradiation range S2 by the infrared LED element IR2 arranged on the reference line L1 becomes a vertically long as shown in the figure because it becomes a diffused emission as described above.
  • the irradiation range S1 by the infrared LED element IR1 arranged to be shifted downward from the reference line L1 is narrowed to the upper side as described above, the light guide 8 of the glass plate 3 as shown in the figure. It becomes the range shortened in the vertical direction.
  • the infrared LED element IR1 is arranged near the center of the light guide 8 in the longitudinal direction, and the irradiation range S1 is the central portion in the horizontal direction of the glass plate 3, so that the infrared LED element IR1 alone is the glass plate 3. Illuminance decreases for the vicinity of the side edge in the horizontal direction.
  • the vicinity of the side edge of the glass plate 3 is irradiated by the outer infrared LED element IR2.
  • the outer infrared LED element IR2 is arranged on the reference line L1, and the emission light emitted from the emission surface 8d spreads downward as shown in FIG. 8, so that the irradiation range is as shown in FIG.
  • the vicinity of the side edge of the glass plate 3 can be irradiated over the entire length in the vertical direction.
  • the infrared LED element IR1 arranged corresponding to the upper light guide 8 irradiates the front side (near the upper light guide 8) of the glass plate 3, the rear side (upper guide) of the glass plate 3 is irradiated. The illuminance on the side far from the light body 8 is reduced. Therefore, the rear side of the glass plate 3 is irradiated by the infrared LED element IR3 arranged corresponding to the lower light guide 9 as shown in S3 of FIG.
  • the boundaries indicating the irradiation ranges S1 to S3 in FIG. 9 are illustrated so that the entire surface of the glass plate 3 is not partitioned, only the general ranges of the irradiation ranges S1 to S3 are shown.
  • the illuminance does not drop sharply outside the boundary, and the necessary illuminance is obtained even at the outer part of the boundary.
  • sufficient illuminance is obtained because the portions where the illuminances are reduced overlap.
  • the entire surface of the glass plate 3 could be irradiated with sufficient illuminance and substantially uniformly by the irradiation ranges S1 to S3 by the infrared LED elements IR1 to IR3.
  • the ultraviolet LED element UV Since the wavelength of the ultraviolet light is shorter than that of the white light, the ultraviolet light is more easily refracted than the white light, and when the same lens (prism) is used, the ultraviolet light is slightly condensed with respect to the white light.
  • the light distribution characteristic of the UV LED element UV which is generally easily available, is considerably wider than the light distribution characteristic of the white LED element WL, and the emission range of the ultraviolet light emitted from the emission surfaces 8d and 9d of the light guides 8 and 9 is large. Since UV light is wider than white light, UV light is diffused more than white light in both the curved direction of the exit surfaces 8d and 9d and the linear direction (longitudinal direction of the light guides 8 and 9).
  • FIG. 10 is an explanatory view showing a state in which the position of the ultraviolet LED element is shifted. Thereafter, using FIG. 10, similarly to the infrared LED element IR, the emission surfaces 8d and 9d of the light guides 8 and 9 are formed in a shape that prioritizes the uniform illumination distribution by the white LED elements WL, The arrangement of the ultraviolet LED elements UV1 to UV9 when the light guides 8 and 9 are used will be described below.
  • the ultraviolet LED element UV when the ultraviolet LED element UV is disposed on the reference line L 1, the light distribution characteristics of the ultraviolet light as described above, from the emission surface 8 d as shown by the two-dot chain line in FIG. The emitted light is greatly spread and emitted, resulting in a problem that the illuminance decreases. Further, if there is light that is greatly refracted toward the lower side of the light guide 8 due to the wide light distribution of the ultraviolet LED element UV and the refractive index of the ultraviolet light, the reflecting mirror 14 is caused by the light. May be directly irradiated. Even in the case of ultraviolet light, if there is light directly illuminating the reflecting mirror 14, the reflected light may become stray light and enter the camera 13.
  • the emitted light from the exit surface 8d is on the reference line L1.
  • the upper side is substantially the same direction, but the lower side is directed upward.
  • each of the ultraviolet LED elements UV1 to UV4 arranged corresponding to the light guide 8 is arranged so as to be shifted downward (that is, on the side where the radius of the emission surface 8d is small) with respect to the reference line L1, as described above. ing. Further, the adjacent ultraviolet LED elements UV1 and UV2 are arranged so as to be shifted relative to the reference line L1 in the Y direction. This is because when the adjacent objects are the same in the Y direction, the irradiation position in the Y direction is the same. Therefore, when there is uneven illuminance in each Y direction, it is emphasized and unevenness is prevented from occurring. Because. Similarly, the adjacent ultraviolet LED elements UV3 and UV4 are also relatively displaced in the Y direction. The amount of deviation is as large as possible within a range where the irradiation range does not change greatly. In this way, mutual interference due to the light distribution between adjacent ones can be reduced as much as possible.
  • each of the ultraviolet LED elements UV5 to UV9 is shifted downward with respect to the reference line L2, and is also shifted in the Y direction between adjacent ones.
  • Each of the ultraviolet LED elements UV1 to UV9 is arranged more than the other LED elements because the output of the generally easily available ultraviolet LED elements is relatively low.
  • the reader 1 of this embodiment functions as an OCR (Optical Character Reader).
  • OCR Optical Character Reader
  • OCR for reading passports and licenses may be used for authenticity determination.
  • white light is used for illumination when reading as OCR.
  • FIG. 11 is an explanatory diagram showing the illuminance distribution in the image due to the influence of the camera lens.
  • an image captured by the camera 13 has a problem that the peripheral light amount on the screen decreases due to the influence of so-called vignetting and the cosine fourth power law.
  • a sufficient amount of light can be obtained in the circle of the broken line in FIG. 11, for example, which is the central portion Sc collected by the lens of the camera 13 with the object of the imaging range as the entire surface of the glass plate 3, but the periphery outside the range Sc
  • the amount of light decreases in the portion Ss.
  • FIG. 12 (a) is an explanatory view showing a prism provided on the upper light guide
  • FIG. 12 (b) is an explanatory view showing a prism provided on the lower light guide.
  • the adjustment of the illuminance distribution includes two configurations: a configuration corresponding to the above-described decrease in the amount of peripheral light, and a configuration that prevents a decrease in illuminance at the central portion of the document surface due to the structure of the reading apparatus according to the present invention.
  • the camera 13 is positioned on the right side of the drawings in FIGS.
  • the portion facing the white LED element WL1 on the incident surface 8b of the upper light guide 8 is constituted by an inclined surface formed to be concave with respect to the incident surface 8b, as shown in FIG. 12 (a).
  • the first prism 21 serving as the optical path refracting section and the second prism 22 serving as the second optical path refracting section configured by a plurality of similarly inclined slopes are provided.
  • the light emitting element is not disposed at a position corresponding to the central portion in the longitudinal direction of the light guides 8 and 9 (see FIGS.
  • the document surface facing the central portion in the longitudinal direction is Although it is disadvantageous in terms of illuminance, the first prism 21 is formed of a slope that is recessed on the side edge side of the glass plate (original surface) 3 with respect to the white LED element WL1, and the above-described white LED element WL1
  • the light Lw3 emitted toward the side edge is refracted toward the center. Thereby, the light which leaks to the outer side of the glass plate 3 can be condensed on the peripheral part inner side part of the glass plate 3, and the illumination intensity of the part can be raised.
  • the second prism 22 is composed of a plurality of small slopes recessed continuously on the central side of the glass plate 3 with respect to the first prism 21, and each slope is provided with pitches p1 to p4. It is formed in a sawtooth shape.
  • the second prism 22 disperses and refracts the light Lw4 emitted from the white LED element WL1 toward the central portion. Since the upper light guide 8 is close to the glass plate 3 and has a short light traveling distance, the light does not sufficiently strike the center of the glass plate 3 when the second prism 22 is not provided, and the illuminance directly above the camera 13 is high. Extremely low.
  • the second prism 22 having a larger inclination angle ⁇ 2 with respect to the incident surface 8b than the first prism 21 is refracted toward the center of the glass plate 3 to prevent a decrease in illuminance at the center of the glass plate 3.
  • the reason why the second prism is provided at a narrower pitch than that of the first prism is a measure for imparting a relatively large tilt angle ⁇ 2 to the second prism while the size of the light guide is limited.
  • a third prism 23 is provided as an optical path refracting section constituted by The third prism 23 is provided in the same manner as the first prism 21, and concentrates the light Lw5 leaking outside the glass plate 3 on the inner peripheral portion of the glass plate 3 to increase the illuminance of that portion. Can do.
  • the lower light guide 9 is a flat surface on which the incident surface 9b is formed on the center side of the glass plate 3 opposite to the third prism 23. This is because, since the lower light guide 9 is far from the glass plate 3, the white LED element WL ⁇ b> 2 is directed toward the center of the glass plate 3 even if it is flat without providing an optical path refracting portion like the second prism 22. This is because the light Lw6 emitted in this way can reach the center of the glass plate 3.
  • FIG. 13 is an explanatory diagram showing the distribution of the range in which the illuminance is increased by the white LED elements, and shows the illuminance distribution by the white LED elements WL1 and WL2 due to the provision of the prisms 21-23.
  • the strong illuminance range S4 by the left and right white LED elements WL1 of the upper light guide 8 is substantially the upper half in the figure on the upper light guide 8 side of the glass plate 3, as shown in FIG.
  • the light beam that illuminates the portion directly above the camera 13 is a light beam that can avoid the camera 13, resulting in a significant decrease in illuminance.
  • the second prism 22 irradiates the light directly distributed over the range of the portion directly above the camera 13, but the intensity of illumination is suppressed.
  • the position of the white LED element WL1 in the X direction and the shapes of the first and second prisms 21 and 22 are set so as to obtain such an illuminance distribution.
  • the shape of the prism optical path refracting portion
  • the inclination angle ⁇ of the inclined surface with respect to the incident surface 8b, the length L of the inclined surface, the pitches p1 to p4 when a plurality of inclined portions are continuously provided, and the like (FIG. 12A)
  • the inclination angle ⁇ corresponds to ⁇ 1 and ⁇ 2 in FIG.
  • the strong illuminance range S5 by the left and right white LED elements WL3 of the lower light guide 9 is a substantially lower half in the figure on the side farther from the lower light guide 9 of the glass plate 3, as shown in FIG. Across the entire surface. Since this portion corresponds to the peripheral portion Ss in FIG. 11, the illuminance should be increased over the entire region. Therefore, the same applies to the portion closer to the center of the glass plate 3 as in the range S4 in FIG.
  • the position of the white LED element WL3 in the X direction and the shape of the third prism surface 23 are set so as to irradiate to the extent.
  • the lower light guide 9 is not provided with a plurality of short sloped prisms (second prisms 22) on the center side of the glass plate 3, but the specification of the reading device and the glass plate 3 are not included.
  • the second prism 22 may be provided with a prism composed of a plurality of slopes in which the length and pitch of each slope are changed.
  • the optical path refracting portion is constituted by a slope that is inclined with respect to a plane orthogonal to the incident optical axis, but is called a prism, but the optical path refracting portion has a function of bending the optical path.
  • Any optical device may be used, and the present invention is not limited to a sloped shape that is concave or convex with respect to the incident surfaces 8b and 9b.
  • the light guides 8 and 9 arranged in two rows have been described. However, the light guides 8 and 9 may be arranged in three rows or more, or in a single row when the application is limited. There may be.
  • LEDs 7 as a plurality of light-emitting elements are arranged in a straight line in the longitudinal direction in two rows (see FIG. 4 and the like), and the emission surfaces of the LEDs 7 in each row
  • Each of the rod-shaped light guides 8 and 9 is arranged for each row so as to cover each.
  • a resin spacer 16 provided with an opening corresponding to the LED 7 portion arranged on the illumination board 6 is provided between the illumination board 6 and each light guide 8, 9.
  • the wall surface of the opening provided in the spacer 16 has a tapered shape that spreads in the light emission direction, and the light emitted from the LED 7 is reflected by this wall surface and efficiently guided into the light guides 8 and 9.
  • FIG. 14 is an overall view of the light guide of the reading apparatus according to the present invention.
  • the upper light guide 8 has a shape in which the left and right sides thereof are axisymmetric at the center in the longitudinal direction.
  • the lower light guide 9 is also screwed to the illumination board 6 using the mounting holes 8a provided at three positions with both ends. It has a shape that is line symmetric and is screwed to the illumination board 6 using the respective mounting holes 9a provided at three locations in the longitudinal center and both ends (each screw is not shown).
  • the light guides 8 and 9 are each configured as a single body, but the LED 7 is not disposed at the position corresponding to the central portion in the longitudinal direction of each of the light guides 8 and 9 on the illumination board 6. Since the portion does not have an optical function, the light guides 8 and 9 may be divided at the central portion in the longitudinal direction. In this way, electrical components can be arranged on the illumination board 6 corresponding to the divided portion, so that the mounting efficiency of the illumination board 6 is improved.
  • an image of the surface to be read 4 a of the passport 4 placed on the upper surface of the glass plate 3 is imaged at the center in the longitudinal direction of the upper light guide 8 and on the upper side thereof.
  • a camera 13 as an imaging device is provided, and a reflecting mirror 14 for bending the optical path of the image of the read surface 4 a toward the camera 13 is provided at a position facing the camera 13. The reason for bending the optical path in this manner is effective for making the reading device 1 compact.
  • FIG. 15 is a cross-sectional side view of the main part of the light guide of the reading apparatus according to the present invention.
  • FIGS. 3, 15 and 16 show one side as a representative.
  • a white LED 7a for visible light and a red for infrared light are provided in a direction from one end side which is the right side of the drawing to the central portion which is the left side of the drawing.
  • An outer LED 7b, three ultraviolet LEDs 7c for ultraviolet rays, a white LED 7a, an infrared LED 7b, and an ultraviolet LED 7c are arranged in this order.
  • the incident surfaces 8b and 9b facing the LED 7 of the light guides 8 and 9 are formed on a plane orthogonal to the optical axis of the emitted light of the LED 7, but are partially on the incident surfaces 8b and 9b.
  • Recessed prism surfaces 8c and 9c are provided in a plurality of different shapes (the prism surfaces are inclined surfaces facing one end side or the center of the light guides 8 and 9). Further, on the side opposite to the incident surfaces 8b and 9b of the light guides 8 and 9, an arc is formed around the axis along the longitudinal direction of the light guides 8 and 9, and linearly extends in the longitudinal direction.
  • Outgoing surfaces 8d and 9d made of curved surfaces are provided.
  • the emission surfaces 8d and 9d may be formed by a cylindrical surface of a cylindrical lens, for example.
  • the LED 7 is considered as a point light source, and the emitted light is generally emitted radially around the optical axis that is the maximum light quantity (some light quantities on the optical axis are designed to be slightly lower).
  • the white LED 7a disposed as a light guide 9 in the approximate center of the range illustrated will be described as a representative.
  • the direction of the optical axis Cw The light L1 emitted to the light enters the light incident surface 9b perpendicularly to the light guide 9, and travels straight from the light emission surface 9c in the direction of the optical axis Cw.
  • the light L2 emitted obliquely with respect to the optical axis Cw from the white LED 7a toward the central portion of the light guide 9 is incident obliquely on the incident surface 9b and is inclined at an inclined angle from the output surface 9b. The light is emitted toward the center of the light guide 9.
  • the light L3 incident on the prism surface 9c with light emitted obliquely with respect to the optical axis Cw from the white LED 7a toward the outer side opposite to the central portion of the light guide 9 is refracted by the prism surface 9c.
  • the prism surface 9c is formed as an inclined surface having an angle for refracting the light L3 so as to be emitted substantially parallel to the optical axis Cw.
  • the light L3 emitted toward the outside from the white LED 7a in the illustrated example can be caused to travel straight in the direction of the optical axis Cw, and the light can be efficiently diffused by preventing unnecessary diffusion of light.
  • the inclined surfaces of the prism surfaces 8c and 9c are set corresponding to the LEDs 7 so that the light emitted toward the outside is refracted toward the center of the light guides 8 and 9 according to the respective positions. Yes.
  • FIG. 3 is a perspective view of the main part of the light guide of the reading apparatus according to the present invention.
  • protrusions 11 and 12 serving as emission direction changing portions protrude at the opposite ends in the longitudinal direction of the light guides 8 and 9 in a square shape with respect to the emission surfaces 8 d and 9 d. are integrally formed.
  • FIG. 3 is a perspective view of the main part of the light guide of the reading apparatus according to the present invention.
  • protrusions 11 and 12 serving as emission direction changing portions protrude at the opposite ends in the longitudinal direction of the light guides 8 and 9 in a square shape with respect to the emission surfaces 8 d and 9 d. are integrally formed.
  • each light guide 8 * 9 may be formed by the acrylic resin represented by PMMA, for example as a transparent material.
  • a white LED 7a is disposed immediately below each of the protrusions 11 and 12, and the light emitted from the white LED 7a is reflected by the back surface portions 11a and 12a as shown by L4 in the figure, and is emitted from the second emission surface. It is emitted from 11b and 12b.
  • the outgoing light undergoes angle conversion mainly in the longitudinal direction of the light guides 8 and 9, but the light guides 8 and 9 are three-dimensional objects, and the light emitted from the light guides is
  • the light emitted from the second emission surfaces 11 b and 12 b is actually the diagonal direction of the glass plate 3 that is the target object mounting portion as a whole characteristic.
  • the angle conversion is applied to.
  • the degree of this angle conversion is determined by designing the inclination (curvature) of the rear surfaces 11a and 12a and the upward angle of the second emission surfaces 11b and 12b to arbitrary values, thereby changing the emission direction from the second emission surfaces 11b and 12b. It can be set freely, and the irradiation angle to the glass plate 3 can be arbitrarily set.
  • FIG. 16 is an enlarged view of a main part showing the shape of the protrusion of the light guide of the reading apparatus according to the present invention.
  • the left and right adjacent sides of the glass plate 3 are irradiated with the light emitted from the protrusions 11 of the upper light guide 8, and the lower light guide 9 is located near the center of the glass plate 3 with respect to the irradiation position. It is made to share so that it may irradiate with the emitted light from the protrusion 12 of this.
  • the curvatures of the rear surfaces 11a and 12a forming the reflective surfaces inside the protrusions 11 and 12 are partially changed.
  • a curved surface having a radius R2 that is convex to the outside (concave outward), a curved surface having a radius R3 that is convex inward, and a curved surface having a radius R4 that is convex outward until reaching the exit surface 8d are continuously formed.
  • the magnitude relationship between the radii is R1 ⁇ R4, R2> R3, but is not limited to this, and may be appropriately changed according to the emission direction of the emitted light from the second emission surface 11b.
  • the emission angle of light reflected at that portion (the angle with respect to the optical axis Cw) can be reduced, and from the second emission surface 11b.
  • the emission angle is also reduced.
  • the radius R1 remains large, the emission direction of the light reflected on the surface will be concentrated. Therefore, the curved surfaces of the radii R2 and R3 which are convex inside the intermediate portion are provided and reflected on the back surface 11a. It is diffused slightly by changing the outgoing angle. Thus, the emission angle from the second emission surface 11b (the angle with respect to the optical axis Cw) can be reduced.
  • the curved shape of the back surface 12a remains convex outward, but on the top side of the protrusion 12, the curved surface has a radius R5, and on the white LED 7a side, the radius The curved surface is R6 ( ⁇ R5). In addition, it is made to change smoothly in the switching part of both radii R5 * R6.
  • the radius R6 on the incident surface 9b side smaller than the radius R5
  • the light reflected by the portion of the radius R6 has an emission angle of the light from the second emission surface 12b (second) than the light reflected by the portion of the radius R5.
  • the exit angle is expressed with respect to the exit surfaces (11b, 12b), it means the angle with respect to the optical axis of the LED 7a (the same applies hereinafter).
  • the irradiation range in the glass plate 3 can be designed to be an appropriate range by arbitrarily setting the curvature of the convex curved surfaces of the second emission surfaces 11b and 12b.
  • FIG. 17 shows a schematic block diagram of the control circuit 210 of the reading apparatus.
  • the control circuit 210 includes a main control unit 210a that performs overall control, an ISP control unit 210b that is an image processing unit connected to the main control unit 210a, an IC chip reading control unit 210c, and antenna control.
  • 210d upper LED control unit 210e, lower LED control unit 210f, and camera control unit 210g connected to ISP control unit 210b, which are driven by, for example, a reading switch (not shown).
  • the camera 13 is connected to the camera control unit 210g, and the LEDs 7a, 7b, 7c disposed corresponding to the upper light guide 8 are connected to the upper LED control unit 210e, and the lower LED control unit Each LED 7a, 7b, 7c arranged corresponding to the lower light guide 9 is connected to 210f.
  • the reading process of the passport 4 placed on the glass plate 3 is executed by a program.
  • the camera control unit 210g performs shooting control of the camera 13 and capture of an image signal, the image signal is subjected to image processing by the ISP control unit 210b, and the image processed data is sent to an external monitor (not shown) via the main control unit 210a.
  • the IC chip reading control unit 210c and the antenna control unit 210d perform authentication by wireless connection with the IC chip embedded in the passport 4, and the main control unit 210a determines whether the code signal is legitimate, for example. judge.
  • the main control unit 210a prepares four modes of left side irradiation, right side irradiation, left and right irradiation, and full surface irradiation, and irradiates the read surface 4a from various directions.
  • the main controller 210a selectively drives the LEDs 7 to be lit according to each mode with respect to the upper and lower LED controllers 210e and 210f.
  • FIG. 18 is a plan view showing an irradiation procedure in the left side irradiation mode
  • FIG. 19 is a plan view showing an irradiation procedure in the right side irradiation mode
  • FIG. 20 is a plan view showing an irradiation procedure in the left and right irradiation mode
  • FIG. It is a top view which shows the irradiation point by.
  • the white LED 7a disposed at a position corresponding to the left protrusions 11 and 12 in FIG. 14 is turned on, and white light is emitted from the glass plate 3 as indicated by an arrow in FIG. Irradiate obliquely from the left to the center.
  • the white LED 7a disposed at the position corresponding to the right protrusions 11 and 12 in FIG. 14 is turned on, and white light is emitted from the glass plate 3 as indicated by the arrows in FIG. Irradiate obliquely from the right to the center.
  • the white LEDs 7a disposed at the positions corresponding to the left and right protrusions 11 and 12 are turned on, and white light is emitted from both the left and right sides of the glass plate 3 as indicated by arrows in FIG. Irradiate obliquely toward the center.
  • the white LED 7a disposed at a position corresponding to the space between the left and right protrusions 11 and 12 (the portion closer to the center of the emission surfaces 8b and 9b) in FIG. As shown by the arrows in FIG. 21, the entire glass plate 3 is irradiated with white light so as to be substantially equal in the left-right direction.
  • the light reflected from the portion having the smaller radius R6 has a larger light emission angle from the second emission surface 12b than the light reflected from the portion having the radius R5. Since a large change occurs in the exit angle from the two exit surfaces 12b, the possibility that the OVI is captured is increased and the inspection on the monitor is facilitated.
  • the emission range from the second emission surface 12b of the lower light guide 9 is set larger than the second emission surface 11b of the upper light guide 8, for example, the broken line A1 in FIG.
  • the central portion of the glass plate 3 can be widely irradiated diagonally, but an area where the illuminance decreases is formed on the left side in FIG. 18, particularly in the lower left corner.
  • the emission angle from the second emission surface 11b of the upper light guide 8 is reduced, the irradiation range is as shown by the broken line A2 in FIG. It can be covered enough.
  • the irradiation is performed in a reverse pattern symmetrical to that in FIG. 18, and it is possible to cope with OVI that changes in color according to the difference in irradiation angle. In this way, light from one direction can be strengthened by irradiation from either the left or right side, and OVI provided to change the color according to irradiation from that direction can be made even easier to see.
  • the left and right irradiation mode in FIG. 20 in the above example, one of the modes is performed in order. However, if it is confirmed that the OVI processing is performed by performing irradiation from the left and right at the same time, If the irradiation mode is performed in advance, and confirmation can be made in that mode, the left and right modes can be omitted.
  • the visibility of OVI may be inferior compared to the case of one at a time.
  • the visual recognition of OVI the image quality is not questioned and there may be some unevenness. Since it is only necessary to visually recognize the change, it can sufficiently cope with confirmation of the presence or absence of OVI.
  • each irradiation range from the projections 11 and 12 shows the case where the entire range of the glass plate 3 cannot be irradiated with sufficient illuminance. If the entire range of the glass plate 3 can be irradiated by one of the light guides 8 and 9 by improving the capability of the white LED 7a or the like, the light guides 8 and 9 may be irradiated separately. Thereby, a clear difference due to irradiation from different directions can be confirmed.
  • the passport 4 is targeted.
  • the subject in the illumination device and the reader provided with the illumination device is not limited to the passport 4, and may be applied to a license, securities, and the like.
  • a white LED 7a is provided for OVI for passport authenticity determination, an infrared LED 7b suitable for reading processing such as character recognition, and an ultraviolet LED 7c that makes it possible to visually check forgery prevention fluorescent ink.
  • an infrared light irradiation mode and an ultraviolet light irradiation mode are set, and each mode is automatically or sequentially executed by a selection switch operation. Confirmation can be easily performed.
  • the infrared LED 7b and the ultraviolet LED 7c may not be provided depending on the specification of the reading target.
  • only white LED 7a corresponding to each protrusion 11 * 12 of the both ends of the light guide 8 * 9 may be sufficient.
  • the reading apparatus according to the present invention can be applied to uses such as a copying machine and a scanner that require that the light reflected by the reading object placing unit be separated from the imaging apparatus.
  • Reading Device 3 Glass Plate (Reading Object Placement Unit) 4 Passport (object to be read) 4a Read surface 6 Illumination board (illumination device) 7 LED row (light emitting element / lighting device) 8 Upper light guides 8b and 9b Incident surfaces 8d and 9d Emission surface 9 Lower light guide 9b Incident surfaces 11 and 12 Projection (light emission direction changing portion) 11a, 12a Back (reflective surface) 11b and 12b Second exit surface 13 Camera (imaging device) 14 Reflecting mirror 16 Spacer 21 First prism 22 Second prism 23 Third prism IR1 to IR3 Red LED element (light emitting element) UV1 ⁇ UV9 UV LED element (light emitting element) WL1 to WL4 White LED elements (light emitting elements)

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Light Sources And Details Of Projection-Printing Devices (AREA)

Abstract

L'invention vise à assurer, dans un dispositif de lecture comportant un dispositif d'éclairage ayant un guide de lumière, qu'une lumière venant du guide de lumière ne peut pas entrer directement dans un dispositif de prise d'image. A cet effet, selon l'invention, en section transversale, vue à partir de la direction longitudinale de guides de lumière (8, 9), les lignes extérieures définissant les faces d'émission incurvées (8d, 9d) de ceux-ci sont formées de façon asymétrique sous la forme de continuation des arcs respectifs, le rayon d'arc sur le côté d'un miroir réfléchissant (14) étant rendu plus petit que le rayon d'arc sur le côté opposé. Par conséquent, bien qu'il y ait un risque pour qu'une lumière parasite émise à partir des guides de lumière quand la face d'émission de ceux-ci est, par exemple, une lentille cylindrique, puisse être réfléchie sur le miroir réfléchissant (14), une quelconque telle lumière arrivant vers le miroir réfléchissant à partir de la face d'émission d'un guide de lumière évite le miroir réfléchissant. Ceci est dû au fait que cette lumière est plus fortement réfractée, car le rayon de la face d'émission sur le côté du miroir réfléchissant est plus petit. Par conséquent, il est possible d'empêcher un éblouissement d'image produit par l'entrée de cette lumière réfléchie dans la caméra.
PCT/JP2012/005927 2011-09-21 2012-09-17 Dispositif de lecture WO2013042348A1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
JP2011206046A JP2013069484A (ja) 2011-09-21 2011-09-21 照明装置およびそれを備える読取装置
JP2011-206046 2011-09-21
JP2011220052A JP2013081075A (ja) 2011-10-04 2011-10-04 読取装置
JP2011-220044 2011-10-04
JP2011-220047 2011-10-04
JP2011220047A JP2013081074A (ja) 2011-10-04 2011-10-04 読取装置
JP2011-220052 2011-10-04
JP2011220044A JP2013081073A (ja) 2011-10-04 2011-10-04 読取装置

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WO2013042348A1 true WO2013042348A1 (fr) 2013-03-28

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020124244A1 (fr) * 2018-12-21 2020-06-25 Sita Information Networking Computing Canada Inc. Kiosque interactif ayant un lecteur de document

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05199367A (ja) * 1992-01-22 1993-08-06 Sharp Corp 光源装置
US20090010020A1 (en) * 2006-03-13 2009-01-08 Canon Components, Inc. Linear lighting apparatus and image reader using the same
US20100195168A1 (en) * 2007-01-25 2010-08-05 Mark Eric Miller Image Illumination and Capture in a Scanning Device
US20100238666A1 (en) * 2009-03-23 2010-09-23 Brother Kogyo Kabushiki Kaisha Prism and lighting device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05199367A (ja) * 1992-01-22 1993-08-06 Sharp Corp 光源装置
US20090010020A1 (en) * 2006-03-13 2009-01-08 Canon Components, Inc. Linear lighting apparatus and image reader using the same
US20100195168A1 (en) * 2007-01-25 2010-08-05 Mark Eric Miller Image Illumination and Capture in a Scanning Device
US20100238666A1 (en) * 2009-03-23 2010-09-23 Brother Kogyo Kabushiki Kaisha Prism and lighting device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020124244A1 (fr) * 2018-12-21 2020-06-25 Sita Information Networking Computing Canada Inc. Kiosque interactif ayant un lecteur de document
US12106592B2 (en) 2018-12-21 2024-10-01 Sita Information Networking Computing Canada, Inc. Interactive kiosk having document reader

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