JP2012060313A - Lighting unit, and image reader provided with lighting unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting unit capable of realizing higher illuminance and high uniformity in illuminance, and to provide an image reader provided with the lighting unit.SOLUTION: A lighting unit of one embodiment is provided with a light source part and a reflection member. The light source part comprises a light-emitting part formed linearly and emitting light. The reflection member comprises a reflection surface reflecting light emitted from the light-emitting part of the light source part, to a predetermined range. The reflection surface has a cross section in the shape of a bent line comprising a plurality of line segments along a reference ellipse having a long axis forming a predetermined angle with a direction perpendicular to the predetermined range, in a direction orthogonal to the longitudinal direction of the light-emitting part of the light source part.

Description

  Embodiments described herein relate generally to an illumination device and an image reading device including the illumination device.

  Conventionally, a paper sheet processing apparatus for inspecting various paper sheets such as banknotes has been put into practical use. The paper sheet processing apparatus includes an image reading device that reads an image of a paper sheet. The paper sheet processing apparatus takes in the paper sheets input into the input unit one by one and conveys them to the image reading apparatus.

  The image reading device includes an illumination unit (illumination device) and a line image sensor. The image reading device irradiates light on a paper sheet conveyed in a predetermined direction by an illumination device. The image reading device reads the transmitted light or reflected light of the light irradiated to the conveyed paper sheet by the line image sensor, and acquires an image.

  The illumination device irradiates light on the surface of a paper sheet as a test object. In this case, the illuminating device desirably has an illuminance distribution that is uniform in the longitudinal direction of the line image sensor. When performing high-speed and high-precision processing, the illumination unit needs to have high illuminance and illuminance uniformity in order to reduce the burden of image processing and signal processing.

  The illumination unit includes, for example, a light source such as a halogen light source or a fluorescent lamp, and a light guide (light guide member) using an optical fiber. In recent years, an illumination unit including a light source (hereinafter simply referred to as an LED) using a light emitting diode has been put into practical use. The illumination unit includes a plurality of LEDs arranged in a straight line or a matrix.

  In order to condense light emitted from a light source within a reading range of a line image sensor, there is an illuminating device including a reflecting member having an arc shape with an elliptical cross section in the sheet conveyance direction. However, when a reflecting member having an elliptical arc shape is used, the peak of the illuminance distribution becomes sharp.

  When the peak of the illuminance distribution is sharp, the range in which the illuminance of the lighting device is uniform becomes narrow. For this reason, there is a problem that it becomes difficult to install the line image sensor and the illumination device in accordance with the peak of the illuminance distribution within the reading range of the line image sensor.

  Further, since the peak of the illuminance distribution is sharp, the illuminance distribution is not uniform within the reading range of the line image sensor. For this reason, there is a problem that the read image may be affected by luminance unevenness, for example, depending on the conveyance state of the paper sheet.

JP 2001-330734 A JP 2010-110938 A

  Accordingly, it is an object of the present invention to provide an illuminating device capable of realizing higher illuminance and higher illuminance uniformity, and an image reading apparatus including the illuminating device.

  The illuminating device which concerns on one Embodiment is provided with a light source part and a reflection member. The light source unit is formed in a linear shape and includes a light emitting unit that emits light. The reflecting member has a reflecting surface that reflects light emitted from the light emitting unit of the light source unit with respect to a predetermined range. The reflecting surface is a polygonal line shape having a plurality of line segments along a reference ellipse having a long axis that forms a predetermined angle with a direction perpendicular to a predetermined range in a direction orthogonal to the longitudinal direction of the light emitting unit of the light source unit. Has a cross section.

FIG. 1 is an explanatory diagram for explaining an appearance of a paper sheet processing apparatus according to an embodiment. FIG. 2 is an explanatory diagram for describing a configuration example of a paper sheet processing apparatus according to an embodiment. FIG. 3 is an explanatory diagram for explaining a configuration example of a control system of the paper sheet processing apparatus according to the embodiment. FIG. 4 is an explanatory diagram for describing a configuration example of the image reading apparatus according to the embodiment. FIG. 5 is an explanatory diagram for describing a configuration example of a light source unit according to an embodiment. FIG. 6 is an explanatory diagram for describing a configuration example of a reflecting member according to an embodiment. FIG. 7 is an explanatory diagram for explaining an example of an arrangement position of the illumination device according to the embodiment. FIG. 8 is an explanatory diagram for explaining the illuminance in the illumination device according to the embodiment. FIG. 9 is an explanatory diagram for explaining the illuminance in the illumination device according to the embodiment. FIG. 10 is an explanatory diagram for explaining a relationship between a reflecting member and illuminance according to an embodiment. FIG. 11 is an explanatory diagram for explaining another configuration example of the reflecting member according to the embodiment. FIG. 12 is an explanatory diagram for explaining the illuminance distribution in the illumination device according to the embodiment. FIG. 13 is an explanatory diagram for explaining another configuration example of the image reading apparatus according to the embodiment. FIG. 14 is an explanatory diagram for describing another example of the arrangement position of the illumination device according to the embodiment. FIG. 15 is an explanatory diagram for explaining another configuration example of the light source unit according to the embodiment. FIG. 16 is an explanatory diagram for explaining still another configuration example of the light source unit according to the embodiment. FIG. 17 is an explanatory diagram for explaining the illuminance distribution in the illumination device according to the embodiment.

  Hereinafter, an illumination device according to an embodiment, an image reading device including the illumination device, and a paper sheet processing device including the image reading device will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram for explaining an appearance of a paper sheet processing apparatus 100 according to an embodiment.
As shown in FIG. 1, the sheet processing apparatus 100 includes a loading unit 112, an operation unit 136, an operation display unit 137, a door 138, an outlet 139, and a keyboard 140 outside the apparatus.

  The input unit 112 is configured to input, for example, a paper sheet 7 as a test object. The input unit 112 receives the stacked paper sheets 7 together. The operation unit 136 receives various operation inputs by the operator. The operation display unit 137 displays various operation guidance and processing results for the operator. The operation display unit 137 may be configured as a touch panel. In this case, the sheet processing apparatus 100 detects various operation inputs based on the buttons displayed on the operation display unit 137 and the operations performed on the operation display unit 137 by the operator.

  The door 138 is a door for opening and closing the input port of the input unit 112. The take-out port 139 has a configuration for taking out the paper sheet 7 from the stacking unit in which the paper sheets 7 determined not to be recirculated by the paper sheet processing apparatus 100 are stacked. The keyboard 140 functions as an input unit that receives various operation inputs by an operator.

FIG. 2 is an explanatory diagram for describing a configuration example of the paper sheet processing apparatus 100 illustrated in FIG. 1.
The sheet processing apparatus 100 includes an input unit 112, a take-out unit 113, a suction roller 114, a conveyance path 115, an inspection unit 116, gates 120 to 125, an exclusion conveyance path 126, an exclusion accumulation unit 127, an accumulation / bundling unit. 128 to 131, a cutting unit 133, and a stacker 134. Further, the paper sheet processing apparatus 100 includes a main control unit 151. The main control unit 151 controls the operation of each unit of the paper sheet processing apparatus 100 in an integrated manner.

  The take-out part 113 is provided in the upper part of the input part. The take-out unit 113 includes a suction roller 114. The suction roller 114 is provided so that the paper sheet 7 set in the input unit 112 is in contact with the upper end in the stacking direction. That is, the suction roller 114 rotates to take the sheets 7 set in the input unit 112 one by one from the upper end in the stacking direction. For example, the suction roller 114 functions to take out one sheet 7 every rotation. Thereby, the suction roller 114 takes out the paper sheets 7 at a constant pitch. The paper sheet 7 taken in by the suction roller 114 is introduced into the conveyance path 115.

  The conveyance path 115 is a conveyance unit that conveys the paper sheet 7 to each unit in the paper sheet processing apparatus 100. The conveyance path 115 includes a conveyance belt and a drive pulley (not shown). The conveyance path 115 operates the conveyance belt by a drive motor and a drive pulley (not shown). The conveyance path 115 conveys the paper sheet 7 taken in by the suction roller 114 at a constant speed by the conveyance belt. In the following description, the side near the take-out portion 113 in the transport path 115 is the upstream side, and the side near the stacker 134 is the downstream side.

  An inspection unit 116 is provided on the conveyance path 115 extending from the extraction unit 113. The inspection unit 116 includes an image reading device 117 and a thickness inspection unit 119. The inspection unit 116 detects optical feature information, mechanical feature, and magnetic feature information of the paper sheet 7. Thereby, the paper sheet processing apparatus 100 inspects the type of the paper sheet 7, the fouling loss, the front and back, the authenticity, and the like.

  The image reading device 117 includes a reading unit having a plurality of image pickup devices such as a charge coupled device (CCD), and an illumination device. The reading unit functions as, for example, a line image sensor. In this case, the reading unit includes a plurality of imaging elements arranged in a direction orthogonal to the conveyance direction of the paper sheet 7.

  The image reading device 117 reads an image of the paper sheet 7 conveyed through the conveyance path 115. The image reading device 117 may be configured to be installed on one side of the conveyance path 115 or may be configured to face both sides of the conveyance path 115. When installed so as to face both sides of the conveyance path 115, the image reading device 117 can read images on both sides of the paper sheet 7 conveyed along the conveyance path 115.

  The image reading device 117 temporarily stores the read image in a memory (not shown) in the inspection unit 116. The sheet processing apparatus 100 can display the image stored in the memory on the operation display unit 137 in accordance with an operation input.

  The thickness inspection unit 119 inspects the thickness of the paper sheet 7 conveyed through the conveyance path 115. For example, if the detected thickness is equal to or greater than a specified value, the paper sheet processing apparatus 100 detects two sheets of the paper sheet 7 being picked.

  Still further, for example, a magnetic sensor for detecting magnetism from the paper sheet 7 conveyed through the conveyance path 115 may be provided.

  Based on the detection results of the image reading device 117, the thickness inspection unit 119, and the like, the main control unit 151 performs the type determination, authenticity determination, correctness determination, and determination of whether or not the sheet is a rejection ticket based on the detection results by the image reading device 117 and the thickness inspection unit 119. Do.

  The main control unit 151 determines the authenticity of the paper sheet 7 based on the detection result of each unit. The main control unit 151 determines that the paper sheet 7 conforming to the preset parameters is a genuine sheet, and the non-conforming paper sheet 7 is a false sheet.

  Further, the main control unit 151 determines the ticket type of the paper sheet 7 based on the detection result of each unit and preset parameters.

  Furthermore, the main control unit 151 determines whether or not the paper sheet 7 is a paper sheet 7 suitable for recirculation based on the detection result of each unit and a preset parameter (determination of damage). I do. That is, the main control unit 151 determines that the paper sheet 7 conforming to the preset parameter is a correct sheet, and the non-conforming paper sheet 7 is an unfit sheet.

  The paper sheet processing apparatus 100 conveys the paper sheet 7 determined to be a genuine note to the stacking / binding unit 128 to 131. Further, the paper sheet processing apparatus 100 conveys the paper sheet 7 determined to be a non-performing ticket to the cutting unit 133. The cutting part 133 cuts the conveyed slip. In addition, the paper sheet processing apparatus 100 may convey and stack the non-use ticket to the stacker 134. The stacker 134 performs sealing every time when the accumulated slips reach 100 sheets, for example.

  Further, the main control unit 151 rejects a paper sheet 7 such as a two-sheet ticket, a paper sheet 7 that is broken or torn, a paper sheet 7 whose ticket type is unknown, a counterfeit ticket, and the like. sheet). The main control unit 151 controls each unit so as to convey the paper sheet 7 determined to be an exclusion ticket to the exclusion stacking unit 127.

  Gates 120 to 125 are sequentially arranged on the conveyance path 115 on the downstream side of the inspection unit 116. Each of the gates 120 to 125 is controlled by the main control unit 151. The main control unit 151 controls the operations of the gates 120 to 125 based on the result of the inspection by the inspection unit 116. As a result, the main control unit 151 performs control so that the paper sheet 7 being conveyed on the conveyance path 115 is conveyed to a predetermined processing unit.

  A gate 120 disposed immediately after the inspection unit 116 branches the conveyance path 115 to an exclusion conveyance path 126. That is, the main control unit 151 controls the gate 120 so as to transport the paper sheet 7 determined to be the rejection ticket to the rejection transport path 126.

  An exclusion stacking unit (exclusion unit) 127 is provided at the end of the exclusion transport path 126. The exclusion stacking unit 127 stacks the exclusion tickets in the posture taken out by the taking-out unit 113. The paper sheets 7 accumulated in the exclusion accumulation unit 127 can be taken out from the take-out port 139.

  Further, stacking / binding portions 128 to 131 (generally referred to as a stacking and binding portion 132) are provided at the branches of the gates 121 to 124, respectively. In the stacking / binding unit 132, the paper sheets 7 determined to be redistributable are stacked separately for each type and front and back. The stacking / binding unit 132 binds and stores the stacked paper sheets 7 every predetermined number of sheets. Also, the paper sheet processing apparatus 100 collects and bundles a plurality of bundles of paper sheets 7 that are bundled every predetermined number by a bundling unit (not shown).

  A cutting portion 133 and a stacker 134 are disposed at a point branched by the gate 125. The cutting unit 133 cuts and stores the paper sheet 7. The stacker 134 accumulates the paper sheets 7 to be conveyed. The main control unit 151 controls the gates 121 to 124 so as to transport the paper sheet 7 determined to be a non-performing paper to the gate 125.

  When the non-paying sheet cutting mode is selected by an operation input from the outside, the main control unit 151 controls the gate 125 so as to transport the paper sheet 7 to the cutting unit 133. Further, the main control unit 151 controls the gate 125 so as to transport the paper sheet 7 to the stacker 134 when the non-paying sheet cutting mode is not selected.

  Note that the main control unit 151 sequentially stores the number of sheets 7 stacked in the stacking / binding unit 132, the number of sheets 7 cut by the cutting unit 133, and identification information.

  FIG. 3 is an explanatory diagram for explaining a configuration example of a control system of the paper sheet processing apparatus 100 shown in FIGS. 1 and 2.

  The sheet processing apparatus 100 includes a main control unit 151, an inspection unit 116, a conveyance control unit 152, a stacking / binding control unit 153, a cutting control unit 156, an operation display unit 137, a keyboard 140, and the like.

  The main control unit 151 governs overall control of the sheet processing apparatus 100. The main control unit 151 controls the conveyance control unit 152 and the stacking / binding control unit 153 based on the operation input by the operation display unit 137 and the inspection result by the inspection unit 116.

  For example, the operator inputs the ticket type, the number of sheets, the damage judgment level, the name of the supplier, the processing method, and the like of the paper sheet 7 to be processed by using the operation display unit 137 or the keyboard 140.

  The inspection unit 116 includes an image reading device 117, a thickness inspection unit 119, other sensors 154, and a CPU 155.

  The image reading device 117 reads an image of the paper sheet 7 conveyed through the conveyance path 115. The image reading device 117 turns on the illumination device and irradiates the paper sheet 7 with light based on the control by the main control unit 151. The image reading device 117 receives reflected light or transmitted light from the paper sheet 7, forms an image of the received light on the image sensor, and acquires an electrical signal (image).

  The main control unit 151 stores an image (reference image) serving as a reference of the paper sheet 7 in the storage unit 151a in advance. The main control unit 151 performs various determinations by comparing the image acquired from the paper sheet 7 with the reference image stored in the storage unit 151a.

  The thickness inspection unit 119 inspects the thickness of the paper sheet 7 conveyed through the conveyance path 115. The other sensors 154 include, for example, a magnetic sensor and / or an ultraviolet image acquisition unit. The magnetic sensor detects magnetism from the paper sheet 7. The ultraviolet image acquisition unit irradiates the paper sheet 7 conveyed through the conveyance path 115 with ultraviolet light, and detects excitation light emitted from the phosphor applied to the paper sheet 7.

  The CPU 155 integrates inspection results obtained by the image reading device 117, the thickness inspection unit 119, and other sensors 154. In addition, the CPU 155 may be configured to determine the type, correctness, front / back, authenticity, and the like of the paper sheet 7 that is transported through the transport path 115 based on the inspection result of each unit.

  The transport control unit 152 controls the take-out unit 113, the transport path 115, the exclusion transport path 126, and the gates 120 to 125 based on the control of the main control unit 151. Thereby, the conveyance control unit 152 controls the taking-in and conveyance of the paper sheet 7. Further, the conveyance control unit 152 performs a sorting process for sorting for each type of the determined paper sheet 7. That is, the transport control unit 152 functions as a sorting processing unit.

  The stacking / binding controller 153 controls the exclusion stacking unit 127 and the stacking / binding units 128 to 131 based on the control of the main control unit 151. Thereby, the stacking / binding controller 153 controls the stacking and binding of the paper sheets 7.

  The cutting control unit 156 controls the operation of the cutting unit 133 based on the control of the main control unit 151. Accordingly, the cutting unit 133 performs cutting of the conveyed paper sheet 7.

FIG. 4 is an explanatory diagram for describing a configuration example of the image reading device 117 illustrated in FIGS. 2 and 3. The image reading device 117 is installed in the vicinity of the conveyance path 115 of the paper sheet processing apparatus 100, for example. Here, it is assumed that the paper sheet 7 is conveyed in the direction of arrow a (conveyance direction) by the conveyance path 115. The transport direction a is parallel to the x-axis direction shown in FIG.
The image reading device 117 includes a reading unit 6 and an illumination device 10.

  As described above, the reading unit 6 detects the optical characteristic information (optical image) of the paper sheet 7. For example, the reading unit 6 has an imaging optical axis in a direction (z-axis direction) perpendicular to a predetermined range on the paper sheet 7 to be conveyed as shown in FIG. The reading unit 6 receives transmitted light or reflected light of light emitted from the illumination device 10 to the paper sheet 7 and acquires an image.

  The reading unit 6 includes, for example, an image sensor such as a CCD and an imaging lens. The imaging lens focuses the received light on the image sensor. The imaging device converts light imaged by the imaging lens into an electrical signal (image). The reading unit 6 includes a plurality of image sensors arranged in a direction orthogonal to the conveyance direction a of the paper sheet 7. That is, the reading unit 6 includes a line image sensor.

  The reading unit 6 has a predetermined range (reading range) that is the same size as the predetermined range (irradiation range) irradiated with light by the illumination device 10 on the paper sheet 7 conveyed by the conveyance path 115 or narrower than the irradiation range. The light is received from and an image is acquired. The reading unit 6 acquires an image for one line from the reading range at one timing. The reading unit 6 acquires an entire image of the paper sheet 7 by continuously acquiring images from the paper sheet 7 conveyed by the conveyance path 115.

  The reading unit 6 may be configured to include a plurality of line image sensors, a dichroic prism, and a color filter. The reading unit 6 separates the light with a dichroic prism and filters the separated light with a color filter. As a result, the reading unit 6 can form images of light having a plurality of different wavelengths on different line image sensors.

  The imaging lens of the reading unit 6 adds an image on the surface of the paper sheet 7 onto the line image sensor. The imaging optical axis of the reading unit 6 may have any configuration as long as it satisfies such an imaging relationship and a relationship between an imaging optical axis of the reading unit 6 and an illumination device 10 described later. For example, the imaging optical axis of the reading unit 6 may be bent by using a mirror or a light guide member.

  The illumination device 10 irradiates light on a predetermined range on the conveyed paper sheet 7 at a timing based on the control of the main control unit 151. The illumination device 10 irradiates at least an irradiation range (irradiated region) wider than the reading range of the reading unit 6.

  Although the reading unit 6 and the illumination device 10 of the image reading device 117 have been described as the configuration for acquiring an image based on the control of the main control unit 151, the configuration is not limited to this configuration. The image reading device 117 includes a sensor that detects the position of the paper sheet 7 conveyed by the conveyance path 115 and a control unit that automatically controls the operations of the reading unit 6 and the light emitting element 12 based on the detection result of the sensor. The structure provided with.

  The illumination device 10 includes a light source unit 15 and a reflecting member 11. FIG. 4 shows a cross section of the reflecting member 11 in the conveyance direction of the paper sheet 7. The light source unit 15 includes a light emitting element 12, a mounting substrate 13, and a heat dissipation member 14.

  The light emitting element 12 is a light emitting element that emits light. The light source unit 15 includes a plurality of LEDs as the light emitting elements 12 arranged in a line in a direction orthogonal to the conveyance direction of the paper sheet 7. That is, the light source unit 15 includes LEDs as a plurality of light emitting elements 12 arranged in a line parallel to the scanning direction of the reading unit 6. That is, the light source unit 15 includes a light emitting unit that is formed in a linear shape and emits light.

  In addition, although this embodiment demonstrates the example which uses LED as the light emitting element 12, it is not limited to this structure. The light emitting element may be configured to use a linear halogen light source or a fluorescent lamp. When an LED is used as the light emitting element 12, the light emitting unit includes a plurality of LEDs arranged in a line.

  The mounting substrate 13 is a base for disposing the LEDs as the light emitting elements 12. The mounting substrate 13 is made of, for example, aluminum, copper, or another material with high heat dissipation. In addition, an electrical circuit for lighting the light emitting element 12 is installed on the mounting board. The heat radiating member 14 is a member for radiating the heat of the mounting substrate 13.

  For example, as shown in FIG. 5, the light source unit 15 has a configuration in which light emitting elements 12A having a center wavelength of a first wavelength and light emitting elements 12B having a center wavelength of a second wavelength are alternately arranged in a line. Is provided. In this case, in the irradiation range, light emitted from the light emitting element 12A and the light emitting element 12B is mixed in the process of being reflected by the reflecting member 11 and converged in the irradiation range. That is, the irradiation range is irradiated with light in which light having the first wavelength and light having the second wavelength are mixed. Thereby, the illuminating device 10 can suppress the nonuniformity of the wavelength of the emitted light. The light source unit 15 may have a configuration in which light emitting elements having the same center wavelength are arranged in a line.

  The reflection member 11 includes a mirror (reflection surface) that totally reflects light. As shown in FIG. 6, the mirror of the reflecting member 11 is formed in a polygonal line along an ellipse (reference ellipse) whose major axis is a straight line that forms an angle θ with the imaging optical axis of the reading unit 6. That is, the mirror of the reflecting member 11 has a plurality of linear shapes that are inscribed in or circumscribed by the arc of the reference ellipse. Further, the mirror of the reflecting member 11 may have a shape in which a node of a broken line of the mirror exists on or near the reference ellipse.

The shape of the cross section of the mirror of the reflecting member 11 is determined by the following method, for example.
First, a reference ellipse is indicated by a broken line in FIG. The focus F1 and the focus F2 of the reference ellipse are specified. When the orthogonal coordinate system is set with the center of the reference ellipse as the origin O, the long axis direction as the x axis, and the short axis direction as the y axis, the focal points F1 and F2 are plotted on the x axis as shown in FIG. Is done.

  Also, let P be the intersection of the reference ellipse and the positive x-axis direction, and Q be the intersection of the reference ellipse and the positive y-axis direction. The mirror of the reflecting member 11 is formed along the elliptical arc of the reference ellipse in the first quadrant.

  The elliptical arc of the reference ellipse in the first quadrant is divided so as to be equiangular when viewed from the focal point F2. For example, the elliptical arc is divided by auxiliary lines arranged at an equal angle as shown by a one-dot chain line in FIG. The angle formed between the x-axis and the auxiliary line (A1) closest to the x-axis is half the angle formed between the auxiliary lines. Further, the angle formed by the straight line including the point F2 and the point Q and the auxiliary line (A5) closest to the y-axis is half the angle formed by the auxiliary lines.

That is, the auxiliary lines A1 to An are

Meet. In Equations 1 and 2, θ is an arbitrary angle determined by the number of broken lines of the mirror. Moreover, n in Formula 1 and Formula 2 shows the number of broken lines in the cross section of the mirror of the reflecting member 11.

  Here, the tangent line of the elliptical arc having the contact point at the intersection of each of the auxiliary lines A1 to A5 and the elliptical arc is specified. The mirror of the reflecting member 11 is formed such that a broken line formed with the intersection of the specified tangents as a node (folding point) has a cross-sectional shape of the reflecting surface of the mirror of the reflecting member 11. In the example shown in FIG. 6, the mirror of the reflecting member 11 is shown with n = 5, but is not limited to this configuration.

  The mirror of the reflecting member 11 is made of, for example, a metal member such as aluminum. That is, the metal member is cut out so that the shape of the cross section becomes the polygonal line shape specified by the above method. Furthermore, a mirror surface (reflection surface) is formed by polishing the surface of the metal member. Thereby, the mirror of the reflecting member 11 can be formed.

  Further, the mirror of the reflecting member 11 may be formed of, for example, a bent sheet metal. In this case, the sheet metal is bent so that the cross-sectional shape becomes the broken line shape specified by the above method. Further, the mirror surface is polished by polishing the surface of the sheet metal. Thereby, the mirror of the reflecting member 11 can be formed.

  Moreover, the mirror of the reflecting member 11 may be formed by, for example, a plurality of rectangular mirrors. In this case, a plurality of mirrors are combined so that the shape of the cross section becomes a polygonal line shape specified by the above method. Thereby, the mirror of the reflecting member 11 can be formed.

  The reflecting member 11 and the light emitting element 12 are arranged at a position shown in FIG. 7, for example. For example, the light emitting element 12 is installed at the position of one focal point F1 of a reference ellipse serving as a reference for the reflecting member 11.

  Further, the reflecting member 11 is installed so that the other focal point F2 of the reference ellipse is positioned in the vicinity of the reading range of the reading unit 6. For example, the reflecting member 11 is formed based on a reference ellipse in which the irradiation range on the paper sheet 7 exists at a position closer to the focal point F1 than the focal point F2. In this case, the focal point F2 exists on the side facing the focal point F1 across the conveyance path 115.

FIG. 8 is a diagram showing a relative illuminance distribution in the illumination device 10.
In the solid line graph of FIG. 8, the focal point F2 is (x, z) = (0, 0) in the coordinate system x, z of FIG. 7, and the irradiated area on the surface of the paper sheet 7 is the same as the focal point F2. Illuminance distribution when at height. The dotted line graph shows the illuminance distribution when the irradiated region is 1.5 mm above the focal point F2 in the z-axis direction. The dashed-dotted line graph shows the illuminance distribution when the irradiated region is 1.5 mm below the focal point F2 in the z-axis direction.

  That is, the graph of FIG. 8 shows an example in which the focal point F2 of the reference ellipse exists in (x, z) = (0, 0) in the coordinate system x, z shown in FIG. Here, the solid line shown in FIG. 8 indicates the illuminance distribution when the paper sheet 7 does not change in the direction of the imaging optical axis (z-axis direction) of the reading unit 6. Further, the dotted line shown in FIG. 8 indicates the illuminance distribution when the paper sheet 7 varies by +1.5 mm in the direction of the imaging optical axis (z-axis direction) of the reading unit 6. Also, the alternate long and short dash line shown in FIG. 8 indicates the illuminance distribution when the paper sheet 7 varies by −1.5 mm in the direction of the imaging optical axis (z-axis direction) of the reading unit 6.

  Note that each illuminance distribution indicated by a solid line, a dotted line, and a one-dot chain line is normalized with the maximum illuminance of the illuminance distribution obtained by optical simulation being 1.

  According to the illuminance distribution shown in FIG. 8, the illuminance when the irradiation range is 1.5 mm above the focal point F2 in the z-axis direction is the case where the irradiation range is 1.5 mm below the focal point F2 in the z-axis direction. Higher than illuminance. For this reason, the illuminating device 10 illuminates the paper sheet 7 more efficiently by installing each part so that the irradiation range on the surface of the paper sheet 7 exists above the focal point F2 in the z-axis direction. can do. Although an example of the illuminance distribution has been described here, the above tendency does not depend on the number of broken lines n of the reflecting member 11 and the length of the major axis of the reference ellipse.

  The number n of the broken lines of the mirrors of the reflecting member 11 is determined based on the required illuminance and the required illuminance uniformity.

  The illumination device 10 desirably has high illuminance in the reading range of the reading unit 6 in order to cope with high-speed conveyance of the paper sheet 7. Further, the paper sheet 7 conveyed at high speed may be fluttered, that is, change in the direction of the imaging optical axis (z-axis direction) shown in FIG. This variation causes a difference in luminance in the image. In order to correct this, an electronic correction process may be required. As a result, the processing speed may decrease and the load may increase.

  Therefore, it is desirable that the illumination device 10 illuminates the paper sheet 7 with uniform illuminance even when the paper sheet 7 fluctuates in the direction of the imaging optical axis of the reading unit 6. For example, the image reading device 117 of a paper sheet 7 such as a printed matter or a card has a change in illuminance within, for example, 10% with respect to a height fluctuation of about ± 1.5 mm of the paper sheet 7. It is preferable.

FIG. 9 is a diagram showing a relative illuminance distribution in the lighting apparatus 10.
The solid line shown in FIG. 9 indicates the illuminance distribution when the paper sheet 7 does not vary in the direction of the imaging optical axis (z-axis direction) of the reading unit 6. Also, the dotted line shown in FIG. 9 shows the illuminance distribution when the paper sheet 7 fluctuates by +1.5 mm in the direction of the imaging optical axis (z-axis direction) of the reading unit 6. In addition, the alternate long and short dash line in FIG. 9 indicates the illuminance distribution when the paper sheet 7 varies by −1.5 mm in the direction of the imaging optical axis (z-axis direction) of the reading unit 6.

  Each illuminance distribution shown in FIG. 9 is normalized based on the illuminance in the irradiation range in the case of the reference position (z = 0). It can be seen that the variation between the illuminance indicated by the solid line, the illuminance indicated by the dotted line, and the illuminance indicated by the alternate long and short dash line is less than 10% within the irradiation range shown in FIG.

  For example, by performing a simulation by changing the amount of fluctuation of the paper sheet 7 in the z-axis direction and the number of folding lines n of the reflecting member 11, the appropriate number of mirror folding lines n of the reflecting member 11 can be specified. .

  An illuminance ratio is calculated based on the amount of change in illuminance within the irradiation range (for example, the absolute value of the maximum amount of change) and the illuminance at the reference position (z = 0). Furthermore, the illuminance ratio is simulated for each number of broken lines of the reflecting member 11. As a result of the simulation, FIG. 10 shows a relationship between the illuminance ratio and the number n of broken lines of the reflecting member 11. When the illuminance ratio shown in FIG. 10 is 90% or more, it can be determined that the variation in illuminance is less than 10%.

  That is, as shown in FIG. 10, when the number n of broken lines of the reflecting member 11 is 10 or less, the illuminance ratio can be maintained at 90% or more. That is, if the number of broken lines of the mirror of the reflecting member 11 is 10 or less, the lighting device 10 can irradiate the irradiation range with light having an appropriate illuminance distribution.

  As described above, by installing the light emitting element 12 and the reflecting member 11, the light of the light emitting element 12 can be efficiently converged in the reading range of the reading unit 6.

  That is, in the illuminating device 10 according to the present embodiment, the mirror image of the light emitting element 12 projected on each of the polygonal mirror surfaces of the reflecting member 11 illuminates the reading range of the reading unit 6. According to this structure, the illuminating device 10 can implement | achieve the irradiation range where illumination intensity is uniform in the conveyance direction (namely, short direction of the illuminating device 10) of the paper sheets 7. FIG. As a result, it is possible to realize the illumination device 10 having a margin strong against an attachment error of the illumination device 10 and the reading unit 6 and a manufacturing error. That is, according to the present embodiment, it is possible to provide an illuminating device that can realize high illuminance and high illuminance uniformity, and an image reading device including the illuminating device.

  Moreover, the illuminating device 10 further includes an end face mirror 16 as shown in FIG. 11 in order to improve the illuminance uniformity in the direction orthogonal to the transport direction of the paper sheet 7 (that is, the longitudinal direction of the light source unit 15). May be.

  FIG. 11A shows the illumination device 10 as viewed from the conveyance direction of the paper sheet 7. Moreover, B of FIG. 11 shows the illuminating device 10 seen from the direction orthogonal to the conveyance direction of the paper sheet 7. FIG. As shown in FIG. 11, the end surface mirror 16 is a planar mirror having a mirror surface (reflection surface). The end surface mirror 16 is provided at the end of the lighting device 10 in the longitudinal direction so as to sandwich the reflecting member 11 and the light source unit 15. For example, the end surface mirror 16 is installed so as to have a mirror surface parallel to a surface constituted by the x-axis direction and the z-axis direction shown in FIG.

  FIG. 12 shows the simulation result of the illuminance distribution in the illumination device 10 having the end mirror 16. FIG. 12 shows a graph normalized so that the maximum value of illuminance is 1. When the end mirror 16 is not provided, the illuminance is low at the end of the illumination device 10. However, when the end surface mirror 16 is provided, the illumination device 10 can illuminate the irradiation range with light having high illuminance uniformity in the longitudinal direction, as shown in FIG.

  Moreover, although the illuminating device 10 was demonstrated as a structure provided with the one reflection member 11 and the light source part 15, respectively in above-described embodiment, it is not limited to this structure. As illustrated in FIG. 13, the illumination device 10 may be configured to include two reflecting members 11 and a light source unit 15, respectively.

  The illumination device 10 further includes a reflecting member 21 and a light source unit 25. The reflection member 21 has the same configuration as that of the reflection member 11. The light source unit 25 has the same configuration as the light source unit 15. That is, the light source unit 25 includes the light emitting element 22, the mounting base 23, and the heat dissipation member 14.

  The reflection member 21 and the light source unit 25 are provided symmetrically with the reflection member 11 and the light source unit 15 with the imaging optical axis of the reading unit 6 interposed therebetween. That is, the mirror of the reflecting member 21 is formed in a polygonal line along a second reference ellipse having a long axis as a straight line that forms an angle −θ with the imaging optical axis of the reading unit 6. Note that the first reference ellipse and the second reference ellipse serving as the reference of the reflecting member 11 are bilaterally symmetric with respect to the imaging optical axis of the reading unit 6.

  The mirror of the reflecting member 21 has a plurality of linear shapes that are inscribed or circumscribed to the arc of the second reference ellipse. Further, the mirror of the reflecting member 21 may have a shape in which the node of the broken line of the mirror exists on or near the second reference ellipse. In addition, since the shape of the mirror of the reflecting member 21 can be specified by the same method as that of the mirror of the reflecting member 11, detailed description is omitted.

  The reflecting member 21 and the light emitting element 22 of the light source unit 25 are arranged at a position shown in FIG. 14, for example. For example, the light emitting element 22 is installed at the position of one focal point F3 of the second reference ellipse that becomes the reference of the reflecting member 21. The reflecting member 21 is installed so that the other focal point F4 of the second reference ellipse is located in the vicinity of the reading range of the reading unit 6.

  In addition, it is preferable that the irradiation range on the surface of the paper sheet 7 by the light source part 15 exists in the position close | similar to the light emitting element 22 arrange | positioned near the focus F1 rather than the focus F2. The reflection member 11 is formed based on a reference ellipse (first reference ellipse) in which the irradiation range on the paper sheet 7 is present at a position closer to the focus F1 than the focus F2. In this case, the focal point F2 exists on the side facing the focal point F1 across the conveyance path 115.

  Moreover, it is preferable that the irradiation range on the surface of the paper sheet 7 by the light source part 25 exists in the position close | similar to the light emitting element 22 arrange | positioned near the focus F3 rather than the focus F4. The reflecting member 21 is formed based on a reference ellipse (second reference ellipse) in which the irradiation range on the paper sheet 7 is present at a position closer to the focal point F3 than the focal point F4. In this case, the focal point F4 exists on the side facing the focal point F3 with the conveyance path 115 interposed therebetween.

  The light emitting element 12 and the light emitting element 22 are installed as shown in FIG. 15, for example. That is, the plurality of light emitting elements 12 and light emitting elements 22 are alternately installed on the mounting boards 13 and 23 in the longitudinal direction of the lighting device 10. By providing the light emitting element 12 and the light emitting element 22 installed as described above, the lighting device 10 can improve the illuminance uniformity in the irradiation range.

  Further, the light emitting element 12 and the light emitting element 22 may include at least two kinds of light emitting elements that emit light having different wavelengths. In this case, the light emitting element 12 includes, for example, a light emitting element 12A that emits light having a first wavelength and a light emitting element 12B that emits light having a second wavelength. The light emitting element 22 includes, for example, a light emitting element 22A that emits light of a first wavelength and a light emitting element 22B that emits light of a second wavelength.

  For example, the light emitting element 12A, the light emitting element 12B, the light emitting element 22A, and the light emitting element 22B are installed as shown in FIG. That is, the light emitting elements 12A and 22A that emit light of the first wavelength and the light emitting elements 12B and 22B that emit light of the second wavelength are alternately arranged on the mounting substrates 13 and 23 in the longitudinal direction of the lighting device 10. Installed. By providing the light emitting element 12 and the light emitting element 22 installed as described above, the lighting device 10 can reduce wavelength unevenness in the irradiation range.

FIG. 17 shows the illuminance distribution in the illumination device 10.
The solid line in FIG. 17 indicates the relationship between the illuminance and the number of broken lines when the paper sheet 7 does not change in the direction of the imaging optical axis of the reading unit 6. 17 indicates the relationship between the illuminance and the number of broken lines when the paper sheet 7 fluctuates by +1.5 mm in the direction of the imaging optical axis of the reading unit 6. The dotted line in FIG. 17 indicates the relationship between the illuminance and the number of broken lines when the paper sheet 7 varies by −1.5 mm in the direction of the imaging optical axis of the reading unit 6.

  As shown in FIG. 17, the illuminating device 10 as shown in FIG. 4 and FIG. 13 irradiates light with high illuminance uniformity in the short direction of the irradiation range, that is, in the transport direction of the paper sheet 7. Can do. As a result, the illuminating device 10 having a margin with respect to the deviation of the reading range of the reading unit 6 in the conveyance direction of the paper sheet 7 can be realized.

  Moreover, as shown in FIG. 17, there are few differences between a solid line, a dotted line, and a dashed-dotted line. That is, the illumination device 10 has a stable illuminance distribution regardless of fluctuations in the direction of the imaging optical axis of the reading unit 6. As a result, it is possible to realize the illumination device 10 having a margin even with respect to fluctuations in the direction of the imaging optical axis of the reading unit 6 of the paper sheet 7.

  That is, the illumination device 10 according to the present embodiment can achieve high illuminance and high illuminance uniformity.

  The illuminance distribution by the illumination device 10 shown in FIG. 4 is asymmetrical with respect to the position of x = 0 as shown in FIG. For this reason, in consideration of fluctuations in the z-axis direction of the paper sheet 7, the reflecting member 11 may be installed so that the peak (maximum value) of the illuminance distribution does not exist within the irradiation range. In this case, the illuminance distribution in the irradiation range may change due to an attachment error of the lighting device 10 or the like.

  However, as described above, by providing the reflecting member 11, the light source unit 15, the reflecting member 21, and the light source unit 25 symmetrically with respect to the position of x = 0, the illuminating device 10 is as shown in FIG. Illuminance distribution can be realized. That is, the illuminating device 10 can realize a symmetric illumination distribution with the imaging optical axis of the reading unit 6 interposed therebetween. Thereby, it is possible to prevent the illuminance distribution in the irradiation range from being changed due to an attachment error of the illumination device 10 or the like.

  Furthermore, as shown in FIG. 17, the illuminating device 10 can keep the change in illuminance with respect to a variation of ± 1.5 mm in the z-axis direction of the paper sheet 7 to less than 10%.

  As described above, the illuminating device 10 includes the reflection member and the light source provided symmetrically with respect to the imaging optical axis of the reading unit 6, and thus illuminance that is symmetrical with respect to the imaging optical axis of the reading unit 6. Distribution can be realized. Moreover, the illuminating device 10 can reduce the change of the illumination intensity with respect to the fluctuation | variation in the z-axis direction of the paper sheet 7. FIG.

  Further, the image reading device 117 including the illumination device 10 and the reading unit 6 can stably acquire an image from the paper sheet 7 conveyed at high speed. In other words, the image reading device 117 can acquire an image with less luminance variation and luminance unevenness from a plurality of paper sheets 7 conveyed at high speed.

  In the above-described embodiment, the image reading device 117 has been described as a configuration that irradiates light to the conveyed paper sheet 7 and reads an image, but is not limited to this configuration. The image reading device 117 may be configured to acquire an image from the stationary paper sheet 7 while moving the illumination device 10 and the reading unit 6. In this case, the illumination device 10 and the reading unit 6 move in conjunction with each other.

  In the above-described embodiment, the reading unit 6 has been described as a configuration that acquires reflected light of light emitted from the illumination device 10, but the configuration is not limited thereto. The reading unit 6 may be configured to acquire transmitted light of light emitted from the illumination device 10. In this case, the reading unit 6 is provided on the side facing the illumination device 10 across the conveyance path 115. That is, the reading unit 6 receives light emitted from the illumination device 10 and transmitted through the paper sheet 7 and acquires an image.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, 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, you may combine suitably the component covering different embodiment.

  DESCRIPTION OF SYMBOLS 6 ... Reading part, 7 ... Paper sheet, 10 ... Illuminating device, 11 ... Reflective member, 12 ... Light emitting element, 13 ... Mounting board, 14 ... Radiation member, 15 ... Light source part, 16 ... End surface mirror, 21 ... Reflective member , 22 ... light emitting element, 23 ... mounting base, 24 ... heat radiating member, 25 ... light source part, 100 ... paper sheet processing device, 112 ... input part, 113 ... take-out part, 114 ... suction roller, 115 ... transport path, 116 ... inspection unit, 117 ... image reading device, 119 ... thickness inspection unit, 151 ... main control unit, 151a ... storage unit, 152 ... transport control unit, 153 ... stacking / binding control unit, 154 ... other sensors, 155 ... CPU, 156... Cutting control unit.

Claims (10)

A first light source part in which a light emitting part for emitting light is formed in a linear shape;
A first reflecting member having a first reflecting surface for reflecting light emitted from the light emitting unit of the first light source unit with respect to a predetermined range;
Comprising
The first reflecting surface is along a reference ellipse having a major axis that forms a predetermined angle with a direction perpendicular to the predetermined range in a direction orthogonal to the longitudinal direction of the light emitting unit of the first light source unit. Having a cross-section that is a polygonal line shape having a plurality of line segments;
Lighting device. The light emitting unit of the first light source unit is installed at the position of the first focal point of the reference ellipse,
2. The illumination device according to claim 1, wherein the first reflecting member is installed such that the second focal point of the reference ellipse is disposed at a position facing the first focal point across the predetermined range.   3. The illumination according to claim 2, wherein the first reflecting surface has a cross section in which the fold line-shaped fold point exists on the reference ellipse in a direction orthogonal to a longitudinal direction of a light emitting unit of the first light source unit. apparatus.   The number of broken line-shaped line segments of the first reflecting surface is specified based on a change in illuminance in the predetermined range with respect to a change in the test object in a direction perpendicular to the predetermined range. Lighting equipment.   The first light source unit includes a light emitting unit in which a plurality of light emitting elements that emit light having a first wavelength and a plurality of light emitting elements that emit light having a second wavelength are alternately formed in a linear shape. The lighting device according to claim 1.   The first reflecting member is provided so as to sandwich the first reflecting surface and the light emitting unit of the first light source unit in the longitudinal direction of the light emitting unit of the first light source unit, and reflects light to be reflected The lighting device according to claim 1, further comprising a surface. A second light source part in which a light emitting part for emitting light is formed in a linear shape;
A second reflecting member having a second reflecting surface that reflects the light emitted from the light emitting unit of the second light source unit with respect to the predetermined range;
Further comprising
The light emitting unit of the second light source unit includes a light emitting unit of the first light source unit across a plane including a direction perpendicular to the predetermined range and a longitudinal direction of the light emitting unit of the first light source unit. Provided in a symmetrical position,
The second reflection surface is provided at a position symmetrical to the first reflection surface across a surface including a direction perpendicular to the predetermined range and a longitudinal direction of the first light emitting unit. The lighting device according to 1. The first and second light source units include a light emitting unit in which a plurality of light emitting elements that emit light are linearly formed at predetermined intervals,
The lighting device according to claim 7, wherein the light emitting elements of the first and second light source units are alternately formed in a longitudinal direction of the light emitting units of the first and second light source units. The first light source unit includes a light emitting unit in which light emitting elements that emit light having a first wavelength and light emitting elements that emit light having a second wavelength are alternately formed in a linear shape,
The second light source unit includes a light emitting element that emits light of a first wavelength and a light emitting element that emits light of a second wavelength in the reverse order of the light emitting elements of the light emitting unit of the first light source unit. The illuminating device according to claim 7, further comprising light emitting portions alternately formed in a linear shape. A light source part in which a light emitting part for emitting light is formed in a linear shape;
A reflective member having a reflective surface for reflecting light emitted from the light emitting unit of the light source unit with respect to a predetermined range;
A reading unit that receives light from within the predetermined range and acquires an image;
Comprising
The reflective surface has a plurality of line segments along a reference ellipse having a major axis that forms a predetermined angle with a direction perpendicular to the predetermined range in a direction orthogonal to the longitudinal direction of the light emitting unit of the light source unit. Having a cross-section that is a polygonal line shape,
Image reading device.

Images