JP2010033176A - Detection device for fluorescence/afterglow, and paper sheet processing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detection device for fluorescence/afterglow and a paper sheet processing unit, enabling the miniaturization and cost reduction of the units and the improvement of afterglow detection performance. <P>SOLUTION: In the detection device for fluorescence/afterglow for detecting fluorescence from fluorescent print information printed with a fluorescent material on a paper sheet P to be conveyed, and for detecting afterglow from phosphorescent print information printed with fluorescent and phosphorescent materials, an optical system 18 is provided for spatially moving a light-receiving optical axis 13a in a fluorescence detection position 13, so as to move it to an afterglow detection position 15. With a single line image sensor 16 disposed at the afterglow detection position 15, both the fluorescence from the fluorescence detection position 13 and the afterglow from the afterglow detection position 15 are received. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides, for example, fluorescent and phosphorescent print information (second print information) from fluorescent print information (first print information) printed on paper sheets such as banknotes to be conveyed and other securities. ) From the fluorescent print information on the transported paper sheet in the paper sheet processing apparatus that sorts the transported paper sheet by type according to the detection result. The present invention relates to a fluorescence / afterglow detection device for detecting afterglow from fluorescence and phosphorescence printing information, and a paper sheet processing apparatus using the fluorescence / afterglow detection device.

  In general, for example, in a paper sheet processing apparatus that sorts paper sheets such as banknotes and other securities by type, fluorescent printing information and phosphorescent printing information printed on the surface of the conveyed paper sheets In the transport path, the fluorescent substance and phosphorescent substance are excited by irradiating excitation light from the excitation light source in the transport path, and the fluorescence detector that detects the emitted light in the excited state and the excitation located on the downstream side of the transport path A fluorescence / afterglow detector having a structure in which an afterglow detector for detecting afterglow of a phosphorescent substance after the end of light irradiation is arranged is used.

  As such a fluorescence / afterglow detection device, two reflection / reception systems are arranged on the upstream side and the downstream side of the conveyance path with an ultraviolet illumination device as an excitation light source, and the fluorescence and afterglow of the paper sheet are separated. The technique of doing is well-known (for example, refer patent document 1). In this known example, the ultraviolet illuminator is turned on intermittently, and the phosphorescent feature is discriminated in the dark, and the fluorescent feature is discriminated by the difference between the bright and dark times.

  Further, a technique for detecting an afterglow feature by arranging a fluorescence feature with an ultraviolet illumination device and a fluorescence detector on the upstream side of the transport path and an afterglow detector on the downstream side of the transport path is known (for example, Patent Documents). 2).

In each of these known examples, fluorescence and afterglow from a paper sheet are detected by arranging two reflection type detectors on the conveyance path.
Japanese Patent No. 3790931 Japanese Utility Model Publication No. 62-2691

  In general, light emission by fluorescent printing information or phosphorescent printing information printed on paper or the like is compared with the amount of fluorescent light emitted from fluorescent printing information emitted in the state excited by ultraviolet light. The amount of afterglow emitted by the phosphorescent printing information is small, and as shown in FIG. 4, it attenuates with time and becomes weak light.

  When the paper sheet is moved by the conveying means, there is a distance L from the absence of the excitation light by the ultraviolet illuminator to the afterglow detection position, and this corresponds to the delay time t shown in the figure, and the emission intensity of the afterglow is Will be reduced.

  Therefore, it is necessary to use a high-sensitivity optical sensor for detecting the afterglow of phosphorescent printed information, which is expensive. Furthermore, since the afterglow from the phosphorescent print information on the paper sheet is weak in the afterglow detection unit, it is necessary to shield light from the outside. The external light includes ambient light around the apparatus, light emitted from an ultraviolet illumination device as an excitation light source, and fluorescence emitted from paper sheets. A device for shielding these external lights is required.

Thus, the light shielding function of the fluorescence detection unit and the afterglow detection unit affects the afterglow detection performance. When two light receiving optical systems are provided close to the conveyance path, there is a problem that this light shielding performance cannot be sufficiently ensured.
Moreover, in such a conventional system, since it is necessary to arrange | position two sets of detectors for fluorescence and afterglow on a conveyance path, there exists a problem which enlarges an apparatus and becomes high-cost.

  Accordingly, an object of the present invention is to provide a fluorescence / afterglow detection device and a paper sheet processing device that can reduce the size and cost of the device and can improve the afterglow detection performance.

  The fluorescence / afterglow detection apparatus of the present invention is a light emission material that is different from the fluorescence and the fluorescence material and has afterglow characteristics from the first print information printed with the fluorescence material on the conveyed paper sheet. A fluorescence / afterglow detection device for detecting afterglow from second print information printed with a substance, a light source for irradiating excitation light on the conveyed paper sheet, and an excitation light by the light source A fluorescence detection position for detecting fluorescence emitted from the first print information on the paper sheet by irradiation, and provided on the downstream side of the fluorescence detection position in the transport direction of the paper sheet; An afterglow detection position for detecting afterglow from the second print information on the leaf, and an optical means for spatially moving a light receiving optical axis of the fluorescence detection position to guide to the afterglow detection position; An afterglow from the afterglow detection position is provided corresponding to the afterglow detection position. And a light receiving means for receiving the fluorescence from the fluorescence detection position guided by the optical means and converting it into an electrical signal, and a determination means for determining the presence or absence of the fluorescence and afterglow based on an output signal of the light receiving means. It has.

  In addition, the sheet processing apparatus of the present invention includes first print information printed with a fluorescent material and second print information printed with a luminescent material that is different from the fluorescent material and has afterglow characteristics. Conveying means for conveying a paper sheet having a light source, a light source for irradiating excitation light on the paper sheet conveyed by the conveying means, and first printing on the paper sheet by irradiation of excitation light by the light source A fluorescence detection position for detecting fluorescence emitted from the information, and a remaining position from the second print information on the paper sheet provided downstream of the fluorescence detection position in the transport direction of the paper sheet. An afterglow detection position for detecting light, an optical means for spatially moving the light receiving optical axis of the fluorescence detection position to guide to the afterglow detection position, and provided corresponding to the afterglow detection position, Afterglow from the afterglow detection position and guided by the optical means A light receiving means for receiving and converting the fluorescence from the fluorescence detection position into an electrical signal; a determination means for determining the presence or absence of the fluorescence and afterglow based on an output signal of the light receiving means; and a determination result of the determination means And sorting processing means for sorting the paper sheets according to the above.

  According to the present invention, it is possible to provide a fluorescence / afterglow detection apparatus and a paper sheet processing apparatus that can reduce the size and cost of the apparatus and improve the afterglow detection performance.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a paper sheet processing apparatus to which a fluorescence / afterglow detection apparatus according to an embodiment of the present invention is applied will be described.

  7 and 8 schematically illustrate the configuration of a paper sheet processing apparatus to which the fluorescence / afterglow detection apparatus according to the embodiment of the present invention is applied. This paper sheet processing apparatus 111, for example, inspects banknotes (hereinafter also referred to as paper sheets) sent from each branch of a plurality of banks, and binds only reusable banknotes and recycles them. It is for use.

  7 and 8, the paper sheet processing apparatus 111 has a supply unit 112 that sets a plurality of stacked banknotes at one end thereof. On the upper part of the supply unit 112, a take-out unit 113 is provided for taking out banknotes set in the supply unit 112 one by one from the upper end in the stacking direction. The take-out unit 113 has a suction roller 114 that rotates while being brought into contact with the uppermost bank note and generating a negative pressure. For example, the suction roller 114 functions to take out one banknote each time it rotates, and operates to take out banknotes at a constant pitch.

  On the downstream side of the take-out portion 113, a conveyance path 115 is extended as a conveyance means for conveying the banknotes taken out by the suction roller 114. A conveyance belt 115 and a drive pulley (not shown) are disposed in the conveyance path 115, and the banknotes are conveyed at a constant speed by running the conveyance belt by a drive motor (not shown).

  On the conveyance path 115 extending from the take-out unit 113, an inspection unit that detects optical and magnetic characteristic information of the banknote being conveyed and inspects the type, defacement loss, front and back, authenticity, etc. of the banknote. 116 is provided. The inspection unit 116 includes two image reading devices 117 and 118 that are arranged on both sides of the conveyance path 115 and read images on both sides of the banknotes to be conveyed. The image readers 117 and 118 have, for example, a CCD camera as an imaging unit, and read a pattern image on the surface of a banknote from the captured image.

  In addition, the inspection unit 116 includes a thickness inspection unit 119 that inspects the thickness of the banknotes conveyed along the conveyance path 115. The thickness inspection unit 119 is used to detect the removal of two banknotes.

  Furthermore, the inspection unit 116 detects fluorescence from fluorescence printing information (first printing information) printed on the banknotes to be conveyed and afterglow from phosphorescence printing information (second printing information). An afterglow detection device 135 is included. Details of the fluorescence / afterglow detection device 135 will be described later.

  In addition, the inspection unit 116 also includes at least one or more magnetic sensors that detect magnetic characteristic information of banknotes.

  For example, six gates 120 to 125 are sequentially arranged on the conveyance path 115 on the downstream side of the inspection unit 116. The gates 120 to 125 are switched according to control by a control unit (not shown) based on the inspection result in the inspection unit 116, and guide the banknote to a predetermined processing unit.

  A gate 120 disposed immediately after the inspection unit 116 is provided at a position where the conveyance path 115 branches to the exclusion conveyance path 126, and is an exclusion ticket that is detected to be not a regular banknote via the inspection unit 116, Further, the inspection unit 116 is switched so as to guide the inspection impossible ticket that could not be inspected to the exclusion conveyance path 126.

  At the end of the reject conveyance path 126, the take-out order of the removal ticket and the non-inspectable ticket is kept in the posture taken out by the take-out unit 113, that is, without turning the front and back sides (in fact, rotated 360 °). An exclusion stacking unit (exclusion unit) 127 that stacks without change is provided.

  In addition to this, the exclusion stacking unit 127 collects, for example, a non-inspectable ticket in which banknotes are duplicated and a fake ticket that is determined not to be a regular banknote.

  Further, at positions branched by the gates 121 to 124 provided along the conveyance path 115 on the downstream side of the gate 120, first to fourth stacking / bundling sections (stacking sections) 128 to 131 (hereinafter, referred to as “the following sections”). In some cases, the collecting / binding unit 132 may be referred to as a collective name. In the stacking / binding unit 132, only the reusable genuine bills out of the regular banknotes other than the rejected ticket guided through the gate 120 are collected and bound.

  For example, the first and second stacking / binding portions 128 and 129 are stacked by bundling 100 correct bills with the surface up, and the third and fourth stacking / binding portions 130 and 131 are stacked. , 100 genuine tickets with the back side up are collected and bundled. Specifically, after collecting 100 sheets of correct bills in the stacking / binding unit 128 and then binding the 100 correct tickets, the other 100 correct tickets are stacked in the other stacking / binding unit 129. Accumulate. The correct bills bundled in the stacking / binding unit 132 in this manner are discharged out of the machine by a conveyor (not shown) and are reused.

  The bank branch other than the rejected ticket guided via the gate 120 is not accumulated in the stacking / binding unit 132 at a position branched from the conveyance path 115 by the gate 125 disposed on the most downstream side. A cutting section 133 is provided for storing a banknote, that is, a regular banknote, which is judged to be non-reusable due to reasons such as loss of pollution, and is made invalid. Note that when the non-slip sheet cutting mode is not selected, the non-slip sheet is not conveyed to the cutting unit 133 but is stacked on the stacker 134 for stacking non-slip tickets.

  Further, the paper sheet processing apparatus 111 has an operation unit 136 that is operated by an operator on the supply unit 112 side. The operation unit 136 is provided with an operation / display panel (display unit) 137 for receiving various operation inputs by the operator and displaying various operation guidance for the operator. The operation / display panel 137 includes a touch panel that detects an input of the button when the operator touches the displayed button. In addition, in the vicinity of the operation / display panel 137, there are a door 138 having a handle for opening and closing the banknote slot of the supply unit 112, an outlet 139 for taking out the banknotes accumulated in the exclusion stacking unit 127, an operator A keyboard 140 or the like operated by is provided.

FIG. 9 schematically shows the configuration of the control system of the paper sheet processing apparatus 111 configured as described above.
In FIG. 9, the main control unit 151 is responsible for overall control, to which the inspection unit 116, the operation / display panel 137 and the keyboard 140 are connected, respectively, and the transport control unit 152 and the stacking / binding unit. Control units 153 are connected to each other.

The main control unit 151 controls the conveyance control unit 152 and the stacking / binding control unit 153 based on an instruction from the operation / display panel 137, an inspection result of the inspection unit 116, and the like.
The inspection unit 116 processes the image reading devices 117 and 118, the thickness inspection unit 119, the fluorescence / afterglow detection device 135, other banknote sensors (such as a magnetic sensor) 154, and data from these. It comprises a CPU (Central Processing Unit) 155 that detects optical and magnetic feature information to determine the type of banknote, fouling loss, front and back, authenticity, and the like.

  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 performing banknote take-out and transport control.

  The stacking / binding controller 153 controls stacking / binding of banknotes by controlling the reject stacking unit 127 and the stacking / binding units 128 to 131 based on the control of the main control unit 151.

Hereinafter, the operation of the paper sheet processing apparatus 111 configured as described above will be briefly described.
First, a set of banknotes is set in the supply unit 112 by an operator's manual work. In this case, the operator opens the door 138 and sets the banknote in the supply unit 112. Thereafter, when the take-out unit 113 is driven, banknotes are taken out one by one from the top end to the transport path 115 one by one. The banknotes taken out on the conveyance path 115 pass through the inspection unit 116 and are inspected.

  At this time, for example, when a plurality of banknotes are taken out by the takeout unit 113, images on the surface of the banknotes at both ends in the stacking direction are read by the image reading devices 117 and 118, respectively. As a matter of course, when only one bank note is normally taken out, the front and back images of the bank note are respectively read.

  The image read from the bank note in this way is temporarily stored in a memory (not shown) in the inspection unit 116 and displayed to the operator via the operation / display panel 137 as necessary. In the present embodiment, among the banknotes taken out by the takeout unit 113, only the images of banknotes accumulated in the exclusion stacking unit 127 are stored in the memory. The image stored in the memory can be switched and displayed by a predetermined operation on the operation / display panel 137.

  Based on the image read by the image reading devices 117 and 118, the inspection result of the thickness inspection unit 119, the inspection result of the fluorescence / afterglow detection device 135, the inspection unit 116 is a legitimate bank note. It is determined whether or not. As a result of the determination, if it is a regular bank note, it is determined whether or not the bank note is a reusable genuine note.

  As a result of this determination, if the bank note is a reusable genuine note, the gate 120 is switched to the direction of the conveyance path 115 toward the stacking / binding unit 132. Then, any one of the gates 121 to 124 is switched in the direction of the stacking / binding unit 132, and the correct bill guided through the gate 120 is stacked on any of the stacking / binding unit 132.

  In the present embodiment, for example, the first and second stacking / bundling units are used to detect a correct ticket whose front pattern is detected by one image reading device 117, that is, a correct ticket conveyed with the surface facing up. Third and fourth stacks of authentic bills that are accumulated on one of 128 and 129 and whose front pattern is detected by the other image reading device 118, that is, are conveyed with the back side up. -It is made to accumulate in any one of the binding parts 130 and 131.

  In this way, the front and back of the regular ticket are prepared. For example, when the first stacking / bundling unit 128 stacks the correct bills on the surface, and when the first stacking / binding unit 128 reaches 100 sheets, the 100 correct bills are bound. At the same time, the collection of the correct bills to the second stacking / binding unit 129 is started, and 100 sheets are alternately stacked and bound to the two stacking / binding units.

  If the banknote is a non-reusable banknote as a result of the determination, the gate 125 is switched, the banknote being transported is guided to the cutting unit 133, and the banknote is cut and expired. . It should be noted that the number of correct and accumulated bills and the number of non-performing bills that have been cut and expired are counted by the main control unit 151 and added up.

  As a result of the determination, if the bank note is not a regular bank note, the gate 120 is switched and the conveyance path 115 is connected to the exclusion conveyance path 126. Then, the inspection unit 116 determines whether or not the processing target medium is another medium. As a result of this determination, if it is determined that the target medium is not another medium, that is, it is determined from any of the images read by the two image reading devices 117 and 118 that the target medium is not another medium. It is determined that the processed medium is not a legitimate bank note, for example, a counterfeited rejected ticket, or it is determined that two or more banknotes have been duplicated, and the processed medium guided to the excluded transport path 126 The processing medium is collected as it is in the exclusion stacking unit 127.

  As a result of the determination, if the target medium is another medium, it is determined that the target medium is a foreign substance, for example, and the transport of the target medium is stopped and stopped on the removal transport path 126. In this way, the medium to be processed stopped on the removal conveyance path 126 is taken out and confirmed by the operator, and is processed manually.

Next, the fluorescence / afterglow detection device 135 will be described in detail.
1 and 2 schematically show an optical system portion of the fluorescence / afterglow detection device 135. FIG. In FIG. 1 and FIG. 2, paper sheets (for example, banknotes) P are fluorescent printing information (first printing information) printed with a fluorescent material on the surface thereof, and a luminescent material different from the fluorescent material. Each having light emission material having afterglow characteristics, for example, phosphorescent printing information (second printing information) printed with a phosphorescent material, and an arrow a shown by a conveying means (corresponding to the conveying path 115) not shown. Conveyed in the direction.

  The ultraviolet illuminating device 11 as a light source for irradiating excitation light onto the paper sheet P has ultraviolet rays for the strip-shaped illumination area 12 set on the paper sheet P to be conveyed in a direction orthogonal to the conveying direction a. (Excitation light) is irradiated to excite fluorescent printing information (fluorescent substance) and phosphorescent printing information (phosphorescent substance) on the paper sheet P.

  In addition, the ultraviolet illuminating device 11 can use, for example, a fluorescent lamp or a cold cathode tube that outputs ultraviolet rays, and can emit ultraviolet rays continuously in time by high-frequency lighting. In addition, in response to the recent trend of increasing the brightness of lighting devices using light emitting diodes (LEDs), lighting devices in which LEDs are arranged in an array in the line direction can also be used. Of course, it is also possible to use an illumination device that uses a light source having ultraviolet rays, such as a mercury lamp, and converts the light distribution on the line in accordance with the detection position.

  A fluorescence detection position 13 for detecting fluorescence emitted from the fluorescence print information on the paper sheet P is set at a site corresponding to the illumination area 12. Fluorescence on the paper sheet P is located at a position located on the back side of the paper sheet P that is conveyed opposite to the fluorescence detection position 13 and at a substantially central portion in the width direction orthogonal to the transport direction a of the paper sheet P. A reference plate 14 having a fluorescent material similar to the print information applied on the surface is provided. Details of the reference plate 14 will be described later.

  The afterglow detection position 15 for detecting the afterglow from the phosphorescent print information on the paper sheet P is located at a predetermined distance L downstream from the fluorescence detection position 13 in the conveyance direction a of the paper sheet P. Is set. Here, the predetermined distance L is determined by the afterglow characteristics of the phosphorescent material to be detected and the transport speed of the transport means (moving speed of the paper sheet P).

  A line image sensor 16 as a light receiving means is disposed in a direction orthogonal to the conveyance direction a of the paper sheet P at an upper portion opposite to the afterglow detection position 15. The line image sensor 16 has a scanning direction “b” in a direction orthogonal to the conveyance direction “a” of the paper sheet P, and an afterglow by the imaging lens 17 with respect to the front half portion 16 a of the light receiving surface with respect to the scanning direction “b”. The light receiving optical axis 15a at the detection position 15 is imaged.

  The light receiving means 16 uses a line image sensor in this embodiment, but for example, an array type sensor such as a color line image sensor is used for the purpose of color separation. In addition, when there is no need for color separation, a monochrome image sensor, a photodiode array, or the like can be used. When it is not necessary to acquire a divided signal in the scanning direction b, a single light receiving element can be provided. In that case, at least two signals for afterglow detection and fluorescence detection can be taken out, or two single light receiving elements are provided.

  Further, as the light receiving means 16, a highly sensitive back-illuminated image sensor as an array sensor, or a device that realizes high sensitivity with a TDI (Time Delay Integration) operation built in a storage function in the paper transport direction. Etc. can be used. In addition to a photodiode as a single light receiving element, an avalanche photodiode or a photomultiplier tube (photomultiplier) can be used as a high sensitivity sensor.

  In an upper part corresponding to the fluorescence detection position 13, an optical system 18 is provided as an optical unit that spatially moves the light receiving optical axis 13 a of the fluorescence detection position 13 and guides it to the afterglow detection position 15. The optical system 18 includes, for example, a substantially hemispherical reflecting mirror 19 and plate-like reflecting mirrors 20 and 21 that bend the optical path and move it to the afterglow detection position 15 (line image sensor 16).

  The optical system 18 that spatially moves the light receiving optical axis 13a at the fluorescence detection position 13 is configured by a plurality of reflecting mirrors 19, 20, and 21 in the present embodiment, but is configured by a glass component such as a prism. An optical element that converts the position of the optical axis using internal reflection can also be realized.

  The light receiving optical axis 13a guided by the optical system 18 is configured to form an image on the rear half portion 16b of the light receiving surface of the line image sensor 16 with respect to the scanning direction b by the imaging lens 22.

  In the optical path between the imaging lens 22 and the light receiving surface of the line image sensor 16, a light amount attenuating means for attenuating the light amount and approximating the received light amount at the fluorescence detection position 13 to the received light amount at the afterglow detection position 15. The neutral density filter (ND: Neutral Density) 23 is provided.

  As described above, the purpose of the neutral density filter 23 is that strong light is emitted from the fluorescent material, but afterglow from the phosphor material is attenuated quickly and becomes weak light. When these two lights are processed by the same light receiving means, it is important that the light receiving means is not saturated by the reception of fluorescence. However, the afterglow from the phosphor is weak and the signal S / N ratio is poor. As the difference between the two becomes larger, such as the fact that the fluorescence is saturated when the afterglow is optimized, the compatibility becomes more difficult. A solution to this problem is attenuation of the amount of fluorescent light, and therefore, a neutral density filter 23 is provided.

  Further, as shown in FIG. 2, the light-receiving member (dark box) as a light-shielding means is surrounded by the light-receiving surface of the line image sensor 16 from the reading surface of the optical system portion described above to limit the entry of light from the outside. It is configured.

  That is, the dark box 24 surrounding the portion of the optical system 18 excluding the light input side and the light output side is provided in the upper part corresponding to the fluorescence detection position 13, and in the upper part corresponding to the afterglow detection position 15, The light input side communicates with the light output side of the dark box 24, and a dark box 25 is provided surrounding the portion from the imaging lens 22 and the neutral density filter 23 to the rear half 16 b of the light receiving surface of the line image sensor 16. A dark box 26 is provided on the upper portion corresponding to the afterglow detection position 15 and surrounds the portion from the afterglow detection position 15 to the front half 16a of the light receiving surface of the line image sensor 16 including the imaging lens 22. .

  The purpose of providing such a light shielding means is that the fluorescence and afterglow from the paper sheet P are weak light, so the influence of external light on the detection light is large. By limiting this, the paper sheet P The amount of light emitted by the fluorescent / phosphorescent substance is stably detected. Examples of the type of external light include ambient light outside the fluorescence / afterglow detection device, light leaking from the ultraviolet illumination device, mutual interference between fluorescence from the fluorescence detection position and afterglow from the afterglow detection position, and the like.

  FIG. 3 schematically shows the configuration of the fluorescence / afterglow detection device 135. The signal from the line image sensor 16 is amplified by the amplifier 31 and then sent to the A / D converter and the signal correction circuit 32. The output is sent to the discrimination processing circuit 33. The presence or absence of is determined. A correction information memory 34 that stores and provides sensor signal correction information is connected to the A / D converter and the signal correction circuit 32, and the discrimination processing circuit 33 stores reference information, discrimination threshold values, and the like in discrimination processing. A judgment reference memory 35 is connected.

Hereinafter, the operation of the fluorescence / afterglow detection device 135 configured as described above will be described.
FIG. 4 shows the relationship between excitation and emission of a general fluorescent material and phosphorescent material by ultraviolet rays. Both the fluorescent substance and the phosphorescent substance emit light having an emission wavelength specific to the substance when excited by being irradiated with ultraviolet rays. As shown in FIG. 4 (a), as compared with a fluorescent material that stops emitting light immediately after the excitation of ultraviolet rays is stopped, as shown in FIG. Go. It is detected as afterglow that the irradiation of ultraviolet rays is stopped and the amount of emitted light is attenuated.

  When the paper sheet P is transported in the direction of the arrow a by a transport means (not shown) and reaches the illumination area 12 (fluorescence detection position 13), ultraviolet light is irradiated onto the paper sheet P from the ultraviolet illumination device 11 as excitation light, The fluorescent printing information (fluorescent substance) and phosphorescent printing information (phosphorescent substance) on the paper sheet P are respectively excited.

  The fluorescence printing information and the phosphorescent printing information excited by the ultraviolet irradiation emit light, and the emitted light passes through the optical system 18, the imaging lens 22 and the neutral density filter 23 to the rear half 16 b of the light receiving surface of the line image sensor 16. An image is formed and converted into an electric signal.

  When the transported paper sheet P passes through the illumination area 12, the ultraviolet irradiation by the ultraviolet illumination device 11 is stopped, so that the light emission from the fluorescence printing information stops immediately as shown in FIG. In the phosphorescent printing information, the amount of emitted light gradually decreases as it decays as shown in FIG.

  Thereafter, when the transported paper sheet P reaches the afterglow detection position 15, the afterglow from the phosphorescent print information on the paper sheet P passes through the imaging lens 17 and the first half of the light receiving surface of the line image sensor 16. An image is formed on 16a and converted into an electric signal.

  An image signal obtained from the line image sensor 16 is sent to an A / D converter and a signal correction circuit 32 via an amplifier 31, where after A / D conversion, sensitivity variations in the scanning direction of the line image sensor 16 are detected. In addition, the brightness unevenness in the line direction of the ultraviolet illuminator 11 and distortion components caused by the imaging lenses 17 and 22 are electrically corrected. The correction information is generated internally and stored in the correction information memory 34, and correction processing is performed.

  The corrected signal is sent to the discrimination processing circuit 33, where the presence / absence of fluorescence / afterglow is discriminated. The presence / absence determination of fluorescence / afterglow is determined, for example, when fluorescence information having a waveform as shown in FIG. 4 (a) is obtained, and the afterglow information having a waveform as shown in FIG. 4 (b). Is obtained, it is determined that there is afterglow.

  In the discrimination processing circuit 33, the detection position is arbitrarily set in the time direction or the scanning direction according to the type of the paper sheet P, color information calculation processing (when a color line image sensor is used), or between detection areas. High-precision fluorescence / afterglow detection performance is realized by performing necessary discrimination processing such as In addition, various environment data, determination parameters, and the like such as area division processing designation information for determination, calculation processing formulas, reference data for determination, determination levels, and the like are stored in or extracted from the determination reference memory 35. Realizes high performance.

  The discrimination result of the discrimination processing circuit 33 is sent to the CPU 155 of the inspecting unit 116, and is used as one of parameters for determining the type or authenticity of the paper sheet P.

  The unevenness in the scanning direction of the line image sensor 16 having the ultraviolet intensity in the ultraviolet illuminator 11 places a fluorescent light emitting medium whose brightness is controlled uniformly at the fluorescence detection position 12 and reads the emitted light by the line image sensor 16. Thus, it is possible to recognize the characteristics of the ultraviolet illumination device 11 and correct the uniform intensity data. This uneven illumination intensity also affects the amount of remaining light observed at the afterglow detection position 15 under the same conditions. By similarly applying the correction information obtained at the fluorescence detection position 13 to the signal at the afterglow detection position 15, the detection performance of the absolute amount can be improved.

  FIG. 5 shows a specific example of fluorescent print information and phosphorescent print information on the paper sheet P, and FIG. 6 shows a specific example of an image acquired from the paper sheet P of FIG. 5 by the above-described operation. . The paper sheet P in FIG. 5 has, for example, phosphor print information (second print information) 41 using a phosphor material at the center, and fluorescence print information (first print) using a phosphor material on both sides in the transport direction a. Information) 42 and 43 are shown, and the paper sheet P is transported in the direction of the arrow a in the figure, and the fluorescence detection position 13 and the afterglow detection position 15 are separated by a distance L. And

  As described above, if afterglow information can be acquired in the first half 16a of the light receiving surface of the line image sensor 16 and fluorescence information can be acquired in the second half 16b of the light receiving surface of the line image sensor 16, the sheet P in FIG. The image shown in FIG. 6 is obtained. In this example, an image that is misaligned in the transport direction a by a distance L is acquired between the fluorescence information and the afterglow information.

  As described above, in the present embodiment, the light receiving optical axis 13a at the fluorescence detection position 13 is spatially moved to the afterglow detection position 15, and the single line image sensor 16 provided at the afterglow detection position 15 is moved. Since the image is formed, information with different physical positions is output at the same time. This positional deviation of the information can be corrected by the discrimination processing circuit 33 in the subsequent stage, whereby the two pieces of information of fluorescence and afterglow can be converted into positional information from the same end face.

Next, details of the reference plate 14 will be described.
As described above, the reference plate 14 is located on the back side of the paper sheet P that is conveyed opposite to the fluorescence detection position 13 and is substantially in the center in the width direction perpendicular to the conveyance direction a of the paper sheet P. In the state where there is no paper sheet P to be conveyed, it emits fluorescent light upon receiving ultraviolet irradiation from the ultraviolet illumination device 11. This state is indicated by a band-like portion 14a which is shaded in the acquired image example of FIG.

  The purpose of the reference plate 14 is to eliminate the influence of the light amount decrease due to the time-dependent change of the ultraviolet illuminating device 11 and the light amount fluctuation with respect to the environmental temperature fluctuation, and to correct so that the absolute value of the light emission amount can be obtained stably. . When the fluorescence information includes a signal for monitoring the light emission amount of the reference plate 14 in the absence of the paper sheet P, it is possible to confirm the light emission amount of ultraviolet rays such as a change with time.

  This can be realized by controlling the gain of the amplifier 31 so that the signal of the reference plate 14 obtained from the line image sensor 16 becomes a constant value by the A / D converter and the signal correction circuit 32. Alternatively, the discrimination processing circuit 33 can perform correction by performing similar image processing from the acquired image information.

  As described above, according to the above-described embodiment, the light receiving means can be integrated into one line image sensor 16 by collecting the light receiving optical axis of fluorescence and the light receiving optical axis of afterglow. This can reduce the size and cost of the apparatus. Further, by moving the fluorescence light reception optical axis to the afterglow detection position, a space can be secured between the fluorescence light reception optical axis and the afterglow light reception optical axis. This space can be used as a space for suppressing external light, illumination light, or disturbance light due to fluorescence emission at the afterglow detection position. Thereby, the afterglow detection performance can be improved.

  Further, by collecting the fluorescence light reception optical axis and the afterglow light reception optical axis in one line image sensor 16, the unevenness in the scanning direction of the line image sensor 16 of the ultraviolet intensity in the ultraviolet illumination device 11 is detected by fluorescence and afterglow. This can be used in common for detection, and the output uniformity of the light emission amount in the scanning position direction of the line image sensor 16 can be improved.

  Similarly, the reference plate 14 is placed on the back side of the paper sheet P to be conveyed at the fluorescence detection position 13, and the light emission amount is monitored to correct the output signal of the line image sensor 16, thereby detecting the absolute amount of the signal. Performance can be improved.

  Furthermore, by combining the fluorescence light reception optical axis and the afterglow light reception optical axis in one line image sensor 16, the sensor sensitivity and light quantity optimization due to the difference in the ratio of the newly generated fluorescence and afterglow light reception quantity can be achieved. This can be avoided by adding a light amount attenuating means (a light reducing filter 23) that attenuates the amount of fluorescent light by a certain amount.

  In the embodiment, the light receiving optical axis 15a of the afterglow detection position 15 is imaged on the front half 16a of the light receiving surface of the line image sensor 16, and the fluorescence detection position is formed on the rear half 16b of the light receiving surface of the line image sensor 16. 13 is configured to form an image on the light receiving optical axis 13a, but in the opposite manner, that is, the light receiving optical axis 13a at the fluorescence detection position 13 is imaged on the front half 16a of the light receiving surface of the line image sensor 16 to form a line image sensor. The light receiving optical axis 15a at the afterglow detection position 15 may be imaged on the rear half 16b of the 16 light receiving surfaces.

  In the above-described embodiment, the case where the second print information is phosphorescent print information has been described. However, the present invention is not limited to this, and is a light emitting material other than a fluorescent material and has afterglow characteristics. The printing information printed with the light emitting substance having the same can be similarly applied.

The perspective view which shows typically the optical system part of the fluorescence and the afterglow detection apparatus which concerns on embodiment of this invention. 1 is a perspective view schematically showing a part of an optical system part of a fluorescence / afterglow detection apparatus according to an embodiment of the present invention. 1 is a block diagram schematically showing a configuration of a fluorescence / afterglow detection apparatus according to an embodiment of the present invention. The wave form diagram which shows the relationship between excitation and emission by a general fluorescent substance and phosphorescent substance by ultraviolet rays. The schematic diagram which shows the specific example of the fluorescence printing information on a paper sheet, and phosphorescence printing information. The schematic diagram which shows the specific example of the image acquired from the paper sheets of FIG. The perspective view which shows typically the external appearance of the paper sheet processing apparatus to which the fluorescence and the afterglow detection apparatus which concerns on embodiment of this invention is applied. The block diagram which shows typically the internal structure of a paper sheet processing apparatus. The block diagram which shows roughly the structure of the control system of a paper sheet processing apparatus.

Explanation of symbols

  P ... paper sheets, 11 ... ultraviolet illumination device (light source), 12 ... illumination area, 13 ... fluorescence detection position, 14 ... reference plate, 15 ... afterglow detection position, 16 ... line image sensor (light receiving means), 17 ... Imaging lens, 18 ... optical system (optical means), 19, 20, 21 ... reflection mirror, 22 ... imaging lens, 23 ... neutral density filter (light quantity attenuation means), 24, 25, 26 ... dark box (light shielding means) 41 ... Phosphorescent printing information (second printing information), 42,43 ... Fluorescent printing information (first printing information), 111 ... Paper sheet processing apparatus, 112 ... Supply unit, 113 ... Taking out unit, 115 ... Conveying Path (conveying means), 116 ... inspection section, 120 to 125 gate, 126 ... exclusion transport path, 127 ... exclusion stacking section, 128 to 131 ... stacking / binding section, 135 ... fluorescence / afterglow detection device.

Claims (4)

From the first print information printed with the fluorescent material on the conveyed paper sheet, from the second print information printed with the fluorescent material and the light emitting material different from the fluorescent material and having afterglow characteristics. A fluorescence / afterglow detection device for detecting the afterglow of
A light source for irradiating excitation light on the conveyed paper sheet;
A fluorescence detection position for detecting fluorescence emitted from the first print information on the paper sheet by irradiation of excitation light from the light source;
An afterglow detection position for detecting afterglow from the second print information on the paper sheet, provided downstream of the fluorescence detection position in the transport direction of the paper sheet;
Optical means for spatially moving the light receiving optical axis of the fluorescence detection position and guiding it to the afterglow detection position;
A light receiving unit that is provided corresponding to the afterglow detection position and receives afterglow from the afterglow detection position and fluorescence from the fluorescence detection position guided by the optical unit, and converts the received light into an electrical signal;
Discriminating means for discriminating the presence or absence of the fluorescence and afterglow based on the output signal of the light receiving means;
A fluorescence / afterglow detection device comprising:   2. A light amount attenuating means is provided for attenuating the amount of light in the light receiving optical axis at the fluorescence detection position to approximate the amount of light received at the fluorescence detection position to the amount of light received at the afterglow detection position. Fluorescence and afterglow detection apparatus as described.   As the light receiving means, a line image sensor having a scanning direction in a direction orthogonal to the transport direction of the paper sheet is used, and the light received at the afterglow detection position in the first half or the second half of the light receiving surface of the line image sensor with respect to the scanning direction. The image of the axis is formed, and the light receiving optical axis of the fluorescence detection position guided by the optical means is formed in the second half or the first half of the light receiving surface of the line image sensor with respect to the scanning direction. Fluorescence / afterglow detector. Transport means for transporting the first printed information printed with the fluorescent material and a paper sheet having the second printed information printed with the light emitting material that is different from the fluorescent material and has afterglow characteristics;
A light source for irradiating excitation light onto a paper sheet conveyed by the conveying means;
A fluorescence detection position for detecting fluorescence emitted from the first print information on the paper sheet by irradiation of excitation light from the light source;
An afterglow detection position for detecting afterglow from the second print information on the paper sheet, provided downstream of the fluorescence detection position in the transport direction of the paper sheet;
Optical means for spatially moving the light receiving optical axis of the fluorescence detection position and guiding it to the afterglow detection position;
A light receiving unit that is provided corresponding to the afterglow detection position and receives afterglow from the afterglow detection position and fluorescence from the fluorescence detection position guided by the optical unit, and converts the received light into an electrical signal;
Discriminating means for discriminating the presence or absence of the fluorescence and afterglow based on the output signal of the light receiving means
Sorting processing means for sorting the paper sheets according to the discrimination result of the discrimination means;
A paper sheet processing apparatus comprising:

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