JP5093200B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus that reads a hologram portion of an irradiated object such as a banknote.

  Conventionally, as this type of reading apparatus, for example, there is a label identification apparatus described in Japanese Patent Laid-Open No. 2000-293105 (Patent Document 1). In Patent Document 1, the light receiving surface of the reflector of the optical identification label 1 is irradiated with the beam light from one light source 10, and the light receiving surface of the reflector converts the beam light into two reflected lights. The light component A is sent toward the first sensor 11, and the second light component B is sent toward the second sensor 12. Further, in the paper sheet recognition apparatus described in Japanese Patent Laid-Open No. 2006-39996 (Patent Document 2), the light emitted from the illumination device 10 and transmitted through the paper sheet 20 is transmitted to the light receiving element 12 by the lens array 11. A guiding arrangement is disclosed.

JP 2000-293105 A (FIG. 1) Japanese Patent Laying-Open No. 2006-39996 (FIG. 1)

  However, the label identification device described in Patent Document 1 irradiates light from the light source onto the light receiving surface of the reflector of the label, and two types of light components reflected on the light receiving surface are different in two installation angles. However, since there is no lens to focus the light, the reading position and focus position of the image to be identified are not determined, and it is possible to identify whether the label is genuine or not. However, there is a problem that it is insufficient for identifying a label at a precise pixel level. In addition, the recognition device described in Patent Document 2 has a problem in that it can recognize the shape of a paper sheet, but in principle cannot read a portion that is not transmitted through the paper sheet. .

  The present invention is a novel image in which a hologram area is read by detecting light reflected by an area where an optical change pattern such as a hologram is pressed or printed on the object to be irradiated, thereby determining the authenticity of the object to be irradiated. An object is to provide a reader.

  In addition, the present invention provides a difference in the spectrum of reflected light generated in the hologram region by irradiating the hologram part (region) with a white light source from different angles to the irradiation unit provided along the conveyance path of the irradiated object. An object of the present invention is to provide an image reading apparatus capable of detecting authenticity by detecting the above.

An image reading apparatus according to a first aspect of the present invention includes a conveying unit that conveys an irradiation object having a hologram region in a part on at least one reading line in the main scanning direction in the conveying direction, and passing the hologram area of the irradiation object. Hologram detection means which is a plurality of sensors arranged along the main scanning direction to detect and output a detection signal, and an object irradiation object conveyed by the conveyance means from the detection signal output from the hologram detection means At a timing when the hologram area of the first area approaches the first irradiation section, the first light source, which is a white light source that irradiates light to the first irradiation section in the hologram area, and the first light source are separated from each other along the transport direction. A second irradiation in the hologram region when the hologram region is transported by a predetermined distance from the first irradiation unit by the transport means; And a second light source that is a white light source for irradiating light, and the hologram region is conveyed by a predetermined distance from the first irradiation unit at an irradiation angle at which the light from the first light source is irradiated to the first irradiation unit. A rod having an optical axis that is different from an irradiation angle of irradiating the light from the second light source to the second irradiating unit, arranged along the main scanning direction, and perpendicular to the transport direction The reflected light of the light emitted from the first light source and the light emitted from the second light source by the irradiated object is received through the lens array, respectively, and an electrical signal related to the hologram area of the irradiated object is received. The level of the electric signals is adjusted by detecting and using the similarity of the waveforms of the portions other than the hologram region in these electric signals.

According to a second aspect of the present invention, there is provided an image reading apparatus including a conveying unit that conveys an irradiation object having a hologram region in a part of at least one reading line in the main scanning direction in the conveying direction, and passing the hologram region of the irradiation object. Hologram detection means which is a plurality of sensors arranged along the main scanning direction to detect and output a detection signal, and an object irradiation object conveyed by the conveyance means from the detection signal output from the hologram detection means At a timing when the hologram area of the first area approaches the first irradiation section, the first light source, which is a white light source that irradiates light to the first irradiation section in the hologram area, and the first light source are separated from each other along the transport direction. A second irradiation in the hologram region when the hologram region is transported by a predetermined distance from the first irradiation unit by the transport means; The second irradiating unit when the hologram region is conveyed by a predetermined distance from the first irradiating unit with respect to the irradiation angle at which the first illuminating unit is irradiated with light from the first light source. A second light source that is a white light source provided so as to be different from an irradiation angle for irradiating light, and an optical axis that is disposed along the main scanning direction and is perpendicular to the transport direction, And a first rod lens array and a second rod lens array for reflecting the reflected light from the first and second irradiating portions in the hologram region, respectively, and the first and second rod lenses. The reflected light of the light emitted from the first light source and the light emitted from the second light source by the irradiated object is received through the array , and an electrical signal relating to the hologram area of the irradiated object is detected. And these And performs level adjustment of the electrical signals to each other using the waveform of the portion other than the hologram region in a gas signal is similar.

According to the present invention, the reflected light of the light irradiated from the first light source and the light irradiated from the second light source by the irradiated object is received and the electric signals are detected, and these electric signals are detected. It is possible to obtain an image reading apparatus that performs level adjustment of electrical signals by using similar waveforms in portions other than the hologram region in FIG.

1 is a cross-sectional configuration diagram of an image reading apparatus according to Embodiment 1 of the present invention. 1 is an overall cross-sectional configuration diagram of an image reading apparatus according to Embodiment 1 of the present invention. It is a top view of the transparent body of the image reading apparatus which concerns on Embodiment 1 of this invention. 1 is a side view of an image reading apparatus according to Embodiment 1 of the present invention. 1 is a plan view of an image reading apparatus according to Embodiment 1 of the present invention. 1 is a circuit configuration diagram of an image reading apparatus according to Embodiment 1 of the present invention. 1 is a flowchart of an image reading apparatus according to Embodiment 1 of the present invention. It is a light source control timing diagram of the image reading apparatus according to the first embodiment of the present invention. It is a light source control timing diagram of the image reading apparatus according to the first embodiment of the present invention. It is an image output timing diagram of the image reading apparatus according to the first embodiment of the present invention. It is a figure explaining the light source irradiation angle of the image reading apparatus which concerns on Embodiment 1 of this invention. It is a figure explaining the kind of light source of the image reading apparatus which concerns on Embodiment 1 of this invention, and the spectral sensitivity of a sensor. It is a top view of the sensor of the image reading apparatus which concerns on Embodiment 1 of this invention, (a) is a monochrome reading sensor, (b) is a color reading sensor. It is a figure explaining the relationship between the insertion direction of the banknote of the image reading apparatus which concerns on Embodiment 1 of this invention, and a hologram. It is a signal processing circuit diagram of the photosensor output of the image reading apparatus according to Embodiment 1 of the present invention. It is a logic diagram of the photosensor output of the image reading apparatus concerning Embodiment 1 of this invention. It is a series of operation | movement flowcharts of the image reading apparatus which concerns on Embodiment 1 of this invention. It is a hologram figure of the image reading apparatus which concerns on Embodiment 1 of this invention. It is a floating island type hologram distribution map of an image reading device concerning Embodiment 1 of this invention, (a) is all the data stored in RAM, (b) is hologram data after reduction, (c) is collation data is there. It is a block diagram explaining the collation method of the image reading apparatus which concerns on Embodiment 1 of this invention. It is a collation waveform diagram of the image reading apparatus according to the first embodiment of the present invention. It is a figure explaining the sensor output divided | segmented according to each spectrum of the image reading apparatus which concerns on Embodiment 1 of this invention. It is a section lineblock diagram of an image reading device concerning Embodiment 2 of this invention. It is a cross-sectional block diagram of an image reading apparatus according to Embodiment 3 of the present invention. It is a top view of the transparent body of the image reading apparatus which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
(Constitution)
Embodiment 1 of the present invention will be described below with reference to FIG. FIG. 1 is a cross-sectional configuration diagram of an image reading apparatus according to the first embodiment. In FIG. 1, reference numeral 1 denotes an object to be irradiated such as a banknote, a securities, or a check, which is preferably a thermocompression bonding part, a printing part, and a sticking part where a hologram processing (holography) is performed on a transparent substrate. In addition, other areas where the color changes depending on the viewing angle, etc., have areas where light is relatively difficult to transmit.

  Reference numeral 2 denotes a transport roller (transport means) for transporting the irradiated object 1 (banknote 1), 2a is a paper feed side transport roller, 2b is a relay transport roller, and 2c is a paper discharge side transport roller. 3 is an irradiation part provided in the conveyance path | route of the banknote 1, 3a is a 1st irradiation part, 3b is a 2nd irradiation part. Reference numeral 4 denotes a white light source (first light source) using plasma excitation such as a fluorescent lamp or a cold cathode tube, 4a irradiates the irradiation unit 3a, and 4b irradiates the irradiation unit 3b. Reference numeral 5 denotes a reflector that efficiently irradiates the light generated by the white light source 4 toward the irradiating unit 3, and reference numeral 6 denotes a pseudo white light source (first light source) formed of an LED array or a rod-like light source equipped with a plurality of light emission sources such as RGB. 6a irradiates the irradiation unit 3a, and 6b irradiates the irradiation unit 3b. Reference numeral 7 denotes a light emitting portion of the pseudo white light source 6, and 8 denotes a white cover that prevents light leakage of the pseudo white light source 6 and serves as a reflector. 9 is a lens array (rod lens array) that converges the reflected light of the light irradiated on the banknote 1, 9a converges the reflected light of the banknote 1 from the irradiation unit 3a, and 9b is the banknote 1 from the irradiation unit 3b. Converges the reflected light.

  Reference numeral 10 denotes a sensor (light receiving unit) configured by linearly arranging a plurality of semiconductor chips that receive light converged by the lens array 9 and perform photoelectric conversion, and a photoelectric conversion unit (photoelectric conversion circuit) for each pixel. 10a receives light from the lens array 9a, and 10b receives light from the lens array 9b. 11 is a sensor substrate on which the sensor 10 is arranged, and 12 is a signal for A / D converting the analog signal photoelectrically converted by the sensor 10, performing signal processing for each pixel, and calculating / processing image information from the banknote 1. Processing IC (ASIC). Reference numeral 13 denotes a substrate constituted by a printed wiring board or the like on which electronic components are mounted, and reference numeral 14 denotes an electronic component such as a capacitor, which is mounted on the substrate 13. 15 is a relay connector for transferring signals and power between the sensor board 11 and the board 13, and 16 is an external connector supported on the back side of the board 13, and includes a system signal (SCLK), a start signal (SI), and a clock signal. (CLK) and an input signal such as a power source, a light source and the like are supplied with electric power, and other control signals are input and output, and an image signal (SIG) and the like are output to the outside.

  17 is a transparent body made of a plastic material or the like provided along the conveyance path, 18 is an internal housing for housing and supporting the lens array 9 and the sensor substrate 11, 19 is a white light source 4, a pseudo white light source 6, a substrate 13, An external housing 20 that houses and supports the transmissive body 17 and the internal housing 18, and 20 is provided inside the external housing 19, and is a light guide path that sets the incident angle of light irradiated from the white light source 4 to the banknote 1 to a narrow angle ( A light guide unit) 21 is a reflective sensor structure (referred to as CIS) that contains components excluding the transport roller 2, and 21a is a first CIS that irradiates the irradiation unit 3a with a white light source 4a at a narrow angle. This is the second CIS for irradiating the irradiation unit 3b with the pseudo white light source 6b at a wide angle. In the figure, the same reference numerals indicate the same or corresponding parts.

  In a reader mounted on a banknote discriminator (paper discriminator) used in the financial terminal field or the like, the intended image may not be read due to the difference between the front and back images of the banknote 1 that is arbitrarily inserted and set. In the first embodiment, a case will be described in which image information on both sides of the banknote 1 is simultaneously read to determine authenticity as shown in FIG.

  FIG. 2 is a cross-sectional configuration diagram of an image reading apparatus in which CIS 21 having the same structure is arranged on both sides of the conveyance path of banknote 1, whereas CIS 21 a and CIS 21 b are arranged on one surface of the conveyance path of banknote 1. The CIS 21c and the CIS 21d are arranged on the other surface while being inverted upside down from the CIS 21a and the CIS 21b. Therefore, in the main scanning direction (reading width direction) orthogonal to the banknote 1 conveyance direction, the CIS 21a and CIS 21b have the same scanning direction and are scanned from the left end to the right end, while the CIS 21c and CIS 21d have the same scanning direction. Scanning from the right end to the left end. In addition, the irradiation unit 3a and the irradiation unit 3c, and the irradiation unit 3b and the irradiation unit 3d are installed separated by a certain distance in the transport path. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  Next, the area | region of the irradiation part 3 is demonstrated in FIG. FIG. 3 is a plan view of the transmissive body 17 mounted on the CIS 21, and 17 w is a groove (opening) of the transmissive body 17 provided in the convergence region of the lens array 9. The opening 17w is formed as a cavity extending from one end to the other end in the main scanning direction with a width of 5 mm with respect to the bill 1 conveyance direction. The transmissive body 17 has a matte black finish on a plastic material, the light irradiated to other than the opening 17w is absorbed, and the light emitted from the opening 17w irradiates the banknote 1 as effective light.

  FIG. 4 is a side view of the image reading apparatus as viewed from the main scanning direction with the conveying unit and the like removed, 22 is a holder for fixing CIS 21a and CIS 21c, 23 is a screw for attaching CIS 21 and holder 22, 24 Is a system support for fixing the CIS 21 to the system main body (reading system) of the image reading apparatus, and 25 is a screw for attaching the holder 22 and the system support 24.

  FIG. 5 is a plan configuration diagram including the conveying unit of the image reading apparatus according to the first embodiment. Reference numeral 30 denotes a detection means (hereinafter simply referred to as “photosensor”) constituted by a separation type photosensor having a light emitting element and a light receiving element, and extends from one end of the banknote 1 to the other end in the main scanning direction of reading. Provided. The photosensor 30 is provided with a connector, and the photosensor 30 is positioned and fixed to a system cradle (not shown) via a stay 31. The photosensor 30 is provided with a predetermined distance (for example, L = 50 mm) apart from the irradiation unit 3a in a direction opposite to the conveyance direction of the banknote 1, and the banknote 1 includes a light emitting element and a light receiving element of the photosensor 30. It is configured to pass between.

  And about the photosensor 30, the light radiate | emitted from the light emitting element is reflected with respect to reflection parts, such as a hologram part of the banknote 1, and does not reach a light receiving element, but a level is substantially zero, and transmission of the banknote 1 is carried out. The part passes through the transmission part and reaches the light receiving element, and exhibits a fluctuation level. Moreover, when there is no banknote 1, the level of a light receiving element shows a saturation value. Therefore, in the conveyance of the banknote 1, the photosensor 30 receives light at a level equal to or lower than the saturation value by the light receiving element until the banknote 1 finishes passing. Further, the output of the light receiving element becomes zero while the banknote 1 passes through the hologram region.

  Reference numeral 32 denotes a cassette for storing banknotes 1 and includes a paper feed side cassette 32a and a paper discharge side cassette 32b. Reference numeral 33 denotes a banknote table on which the cassette 32 is placed, and includes a paper supply-side banknote table 33a and a paper discharge-side banknote table 33b. Reference numeral 34 denotes a transport roller, which includes a paper feed-side take-out roller 34a and a paper discharge-side take-in roller 34b. The conveyance rollers 34a and 34b convey the banknote 1 by driving a motor (not shown) based on a predetermined conveyance signal in synchronization with the conveyance rollers 2a, 2b and 2c.

  Therefore, in FIG. 5, the banknote 1 placed on the upper part of the paper feed side cassette 32a is sequentially transported to the irradiation units 3a and 3c in the reading areas of the CIS 21a and CIS 21c by the transport rollers 34a and 2a. The photo sensor 30 for detecting the edge of the banknote 1 and detecting the transmission part and the hologram area in the transport path of the banknote 1 is provided by five infrared sensors at regular intervals in the main scanning direction of reading. When one hologram region is formed from one end to the other end in the main scanning direction of reading as shown in FIG. 5, the photosensor 30 may be composed of one infrared sensor. .

  Next, the banknote 1 that has passed through the reading area is conveyed to the irradiation units 3b and 3d in the reading area of the CIS 21b and CIS 21d by the conveying roller 2b. Finally, the banknote 1 is stored in the cassette 32b by the transport roller 2c and the transport roller 34b. Here, the transport rollers 2 and 34 are driven accurately in synchronization so that the transport speed of the banknote 1 is transported at, for example, 250 mm / sec. In FIG. 5, the same reference numerals as those in FIGS. 1, 2, and 4 denote the same or corresponding parts.

(Light source on / off control)
FIG. 6 is a circuit configuration diagram of the image reading apparatus according to the first embodiment. In FIG. 6, reference numeral 40 denotes a light source drive that turns on and off the white light source 4 and the pseudo white light source 6 and drives the photosensors 30 and transmits output levels from the five photosensors 30 to the signal processing IC (ASIC) 12. Circuit. A control unit (CPU) 41 controls a series of operations such as the light source driving circuit 40.

  First, a timing signal for first detecting the edge portion of the banknote 1 is input to the CPU 41 of the ASIC 12 by the photosensor 30. At this time, since the conveyance speed of the banknote 1 is constant, the banknote 1 reaches the irradiation section 3a after the time corresponding to the predetermined distance L between the photosensor 30 and the irradiation section 3a, so that the light source driving circuit 40 is driven at that timing. Control to turn on the white light source 4a of the CIS 21a. Similarly, the white light source 4c of the CIS 21c for reading the opposite side of the bill 1 is also turned on. Alternatively, the white light sources 4a and 4c may be turned on simultaneously with a timing signal that first detects the edge portion of the banknote 1.

  Next, when the banknote 1 passes through the photosensor 30, the output of the photosensor 30 fluctuates below the saturation level of the photosensor 30. This level change is determined by the light transmittance of the bill 1. However, in the hologram area (part) of the banknote 1, in addition to the paper thickness of the banknote 1, the metal pattern processing process and the thermocompression bonding process are performed.

  Next, when the opposite edge of the banknote 1 is detected, the processing for one banknote 1 of the photosensor 30 is completed. During this time, the output level of each photosensor 30 is sampled at intervals of 5 ms, and the size of the banknote 1 and the approximate size information of the hologram area are transmitted to the light source drive circuit 40.

  Moreover, since the conveyance speed of the banknote 1 is constant by detection of the opposite edge of the banknote 1, the light source drive circuit 40 is driven and controlled immediately after the opposite edge of the banknote 1 has passed through the irradiation unit 3a after a certain period of time. The white light source 4a of the CIS 21a is turned off. Similarly, the white light source 4c of the CIS 21c for reading the opposite side of the bill 1 is also turned off.

(Operation of entire block configuration)
In FIG. 6, 42 is an amplifier that amplifies a photoelectrically converted analog image signal (SO), and 43 is an A / D (analog / digital) conversion with 256 digits (8 bits) resolution that converts the analog signal (SO) into a digital signal. , 44 is a comparison circuit for comparing the digital output of SO, and 45 is a comparison circuit for comparing the reference data (collation data) of the hologram with the actually measured data.

  First, based on a reading system signal (SCLK) sent from the reading system, a start signal (SI) set at a reading speed of 0.5 ms / Line synchronized with the clock signal (CLK) of the CIS 21 is detected by the sensor 10. Are inputted, the analog signal (SO) photoelectrically converted in the light receiving unit (sensor) 10 is sequentially outputted at the timing. The SO is amplified by the amplifier 42, then analog-digital (A / D) converted by the A / D converter 43, and input to the comparison circuit 44 and the verification circuit 45.

  Next, the comparison input of the comparison circuit 44 will be described. In the first embodiment, the CIS 21a and the CIS 21b are separated and each has a signal processing IC 12. Accordingly, one input of the comparison circuit 44 of the CIS 21a is directly output from the A / D converter 43 of the CIS 21a, and the other input of the comparison circuit 44 is output from the A / D converter 43 of the CIS 21b. Also, one input of the comparison circuit 44 of the CIS 21b is directly output from the A / D converter 43 of the CIS 21b, and the other input of the comparison circuit 44 is output from the A / D converter 43 of the CIS 21a. That is, there is an interpolation relationship.

  The light source driving circuit 40 for the photosensor 30 is performed by the CIS 21a, and the output of the photosensor 30 is sent to both the CIS 21a and the CIS 21b. For comparison, the A / D converted digital data of the CIS 21a read by the white light source 4a is stored in the RAM 1, and the A / D converted digital data of the CIS 21b read by the pseudo white light source 6b is stored in the RAM 2. Stored.

  Next, after the photosensor 30 detects the opposite edge of the banknote 1, when the CIS 21b finishes reading the banknote 1, the RAM1 data and RAM2 data are subtracted and stored in one RAM (for example, RAM1) as difference data. The stored data is further subtracted, and only data larger than a certain value is stored in the other RAM (for example, RAM 2), the address and the number of data are reduced, and an actually measured hologram distribution map is obtained. The reason why the subtraction processing is not performed at the same time is that correction for the singular bit is performed during the second subtraction processing.

  In the second constant value subtraction process, data that does not continuously occur in the main scanning direction and transport direction data during map creation is erased as singular data and set as zero data. That is, it is outside the hologram area. Further, the singular data having a low numerical value in the continuously generated data is left as data not related to the hologram in the hologram area. That is, it is set as a hologram area.

  As another means, when a large number of singular data exists during the creation of the hologram distribution map, the high resolution map may be reduced to the 1/4 resolution map by thinning out the hologram distribution map.

  Next, the verification circuit 45 will be described. The collation circuit 45 is, for example, a hologram distribution map stored in the RAM 2 and reference data (true data) which is stored in the RAM 3 and is a part of digital data obtained by reading the hologram area of the banknote 1 with the white light source 4 and the pseudo white light source 6 in advance. A circuit that is also referred to as a hologram distribution map).

  The RAM 3 data is data in which a part of the data in the hologram area of various banknotes including the banknote insertion direction is distributed and stored in a specified address area. The photosensor 30 can extract the size of the banknote and the approximate size of the hologram area can be determined. Therefore, the address of the corresponding RAM3 data is selected and collated with the hologram distribution map to shorten the collation processing time. In the collation, the number of addresses of the hologram distribution map is set to be larger than the number of addresses of the RAM3 data and the data in the address. Therefore, the RAM3 data is transferred, and the RAM3 data is relatively shifted by the one-dimensional bidirectional register. Collate with hologram distribution map for each address.

  FIG. 7 shows a flow of a series of operations leading to collation. In FIG. 7, STEP1 (S1) to STEP3 (S3) relate to the operation of the photosensor 30, STEP4 (S4) relates to CIS 21a, and STEP5 (S5) relates to CIS 21b reading. STEP 6 (S6) to STEP 9 (S9) are related to comparison and processing, and STEP 10 (S10) to STEP 12 (S12) are related to collation.

  Note that the CIS 21c and CIS 21d installed on the other conveyance surface of the banknote 1 also share the photosensor 30, but are independently driven, and perform comparison / collation operations similar to those of the CIS 21a and CIS 21b.

(Operation timing)
FIG. 8 shows the relationship between the output signal (FO) of the photosensor 30 and the white light source 4a mounted on the CIS 21a and the lighting signal of the white light source 4c mounted on the CIS 21c provided facing the banknote 1 over time. It is a timing chart which showed change to an axis. It is assumed that the banknote 1 is conveyed at 250 mm / sec.

  Since the output signal (FO) of the photosensor 30 is at a high level (saturation level) in the portion where the banknote 1 is not present in the photosensor 30, the light sources 4a and 4c are not turned on (ON). However, when the banknote 1 in the photosensor 30 reaches the edge, the level of the output signal (FO) of the photosensor 30 decreases. At this time, the white light source 4a is turned on from the time when the output signal (FO) of the photosensor 30 falls within a predetermined level range, that is, lower than Vth1, and the white light source 4c having a different irradiation part is turned on with a little delay.

  Further, when the banknote 1 in the photosensor 30 reaches the opposite edge, the output signal (FO) of the photosensor 30 returns to the saturation level, so that the distance (L) between the photosensor 30 and the irradiation unit 3a is increased. The white light source 4a is turned off with a delay. The white light source 4c is also turned off correspondingly. Further, in the hologram area, the light transmittance of the bill 1 is low, so that the output signal (FO) of the photosensor 30 is substantially zero.

FIG. 9 shows the turn-on / off period of each light source of the CIS 21 during the conveyance of banknotes. In the CIS 21a, 21b, the white light source 4a of the CIS 21a is turned on and then turned off. Then, after a predetermined time, the pseudo white light source 6b of the CIS 21b is turned on and then turned off.
Similarly, in the CIS 21c and 21d, the white light source 4c of the CIS 21c is turned on and then turned off. After a certain time, the pseudo white light source 6b of the CIS 21d is turned on and then turned off. When the light sources 4 and 6 are turned on, the start signal (SI) is driven for the continuous lighting period of the clock signal (CLK), and image reading is performed. The system clock signal (SCLK) is time-controlled in conjunction with the CPU 41 at twice the speed of CLK.

  FIG. 10 shows the relationship between the start signal (SI) and the analog image output (SO). The image output (SO) having a predetermined number of bits with respect to the reading cycle (0.5 ms / Line) of the CIS 21. Get. FIG. 10 shows temporal changes in the image output (SO) in the lighting region of the white light source 4 and the lighting region of the pseudo white light source 6, and sequentially images having a predetermined number of bits in synchronization with the start signal (SI). Output (SO) appears. By providing a blanking interval between each line, it is possible to finely adjust the image output (SO) level by changing the reading cycle (0.5 ms / Line).

  That is, since the image read by the white light source 4 and the image read by the pseudo white light source 6 are the same except for the image in the hologram area, the waveform of the image signal (SO) is macroscopically similar and the CIS 21 is independent. Therefore, when the level of the image output (SO) obtained with the white light source 4 and the image output obtained with the pseudo white light source 6 are different, the blanking interval of one CIS 21 is changed (that is, the reading cycle is changed). It is possible to adjust (calibrate) the level of image output (SO) in areas other than both hologram areas.

  Next, the image of the hologram area will be described with reference to FIG. By irradiating the bill 1 with the white light source 4 and the pseudo white light source 6 having a different irradiation angle, the output level is similar except that the absolute level of the output is different except in the hologram region. In contrast to the waveform distribution, different image outputs are obtained by irradiating the light source from different angles in the hologram region. In particular, in the irradiation of the white light source 4, it appears remarkably due to the radiation of a plurality of spectra.

  In the CIS 21, a white light source 4 using a high-power fluorescent lamp or the like is irradiated from a distance at a narrow angle with an incident angle of 30 degrees, and the pseudo white light source 6 is accompanied by RGB light emission, which is the same white light source with a relatively low output. Is achieved at a wide angle of 45 to 60 degrees. In the RGB pseudo white light source 6, as shown in FIG. 12, a white light source is obtained by covering a plurality of visible light regions. However, in the visible light region, an LED light source of another spectrum may be used. Alternatively, a pseudo white light source 6 may be added by adding an LED light source that emits ultraviolet light.

  Further, as shown simultaneously in FIG. 12, the light receiving unit 10 of the CIS 21 has a characteristic of high spectral sensitivity on the red light emission side with respect to the optical wavelength. Accordingly, as shown in FIG. 13A, the light receiving unit 10 receives the reflected light of the white light source 4 as it is, and reads the hologram area and the like. On the other hand, as shown in FIG. 13 (b), after the sensor IC is formed, a color reading RGB filter is divided into three equal parts on the light receiving portion 10, and each pixel is coated and formed with a transparent gelatin material. By filtering a part of the spectrum and appropriately selecting and outputting the image output (SO), it is possible to determine whether the hologram area is color-coded. For example, in FIG. 13B, the image output (SO) is extracted from the G terminal of the sensor 10 by using a filtering function for green colored light (G) in the middle of the visible light region, so that it is different from natural light. The authenticity of the banknote 1 can be determined by optical recognition.

  Next, the insertion direction of the banknote 1 and the identification of the hologram shape will be described with reference to FIG. When the banknote 1 is transported in the longitudinal direction and when it is transported in the short direction, the hologram data stored in the RAM 3 that is the reference data is also different. FIG. 14A shows a case in which a banknote 1 having a band-shaped hologram area in the width direction of the banknote 1 is conveyed in the longitudinal direction of the banknote 1 and is detected by each photosensor 30, and is a vertical band-shaped hologram. Call it. On the other hand, FIG. 14B shows a case where the same banknote 1 is conveyed in the short direction of the banknote 1 and is detected by a part of the photosensors 30 for a relatively long time, and is called a horizontal belt-like hologram. FIG. 14B shows a floating island type hologram that is detected by a part of the photosensors 30 for a relatively short time regardless of the insertion direction of the banknote 1.

  Next, a method for detecting the size of the banknote 1 by the output from the photosensor 30 and detecting the size of the hologram area will be specifically described taking a vertical belt-shaped hologram as an example. FIG. 15 shows a signal comparison circuit incorporated in the light source driving circuit 40 for inputting information (FO) of the photosensor 30 to the ASIC 12 via the light source driving circuit 40. The output of each photosensor 30 specifies the level of the photosensor 30 with two systems of level comparators incorporated in the light source drive circuit 40 and is signal-processed with the ASIC 12.

  FIG. 16 shows the fluctuations in the output of each photosensor 30 as the bill 1 is conveyed. In FIG. 16, the FO1 to FO4 of the photosensor 30 detect the hologram area 50 ms after the banknote edge is detected, shows that the banknote 1 has passed the hologram area 70 ms later, and detects the opposite edge of the banknote 1 150 ms later. ing.

  Moreover, about the banknote 1 reading width | variety, the output (FO5) of the photosensor 30 is not detecting the signal of the banknote 1 always in FIG.

  From the above, in the conveyance of the banknote 1 in the longitudinal direction, the length of the banknote 1 is found from the elapsed time from the first edge detection of the banknote 1 to the edge detection on the opposite side of the banknote 1, and from the transit time of the hologram area of the banknote 1. The length of the hologram area of the banknote 1 is found.

  Further, the approximate width of the banknote 1 is determined from the installation positions of the FO1 to FO5 of the photosensors 30 installed at intervals, and in addition, the approximate width of the hologram area of the banknote 1 is determined. In detecting the width, when high accuracy is required, the installation intervals of the photosensors 30 may be close to each other, or another CIS equipped with a transmissive light source may be added.

  Further, when the detection area of the photosensor 30 is relatively wide and the edge response of the banknote 1 is slow, using a semiconductor laser sensor with a beam spot of about 50 μmφ, the edge detection position is highly accurate and the detection level response time is shortened. In addition, the size of the banknote 1 and the position detection time accuracy of the hologram area may be improved by shortening the sampling time which is the detection time interval.

  From the above, based on the output (displayed by MO1 to MO10) information of the comparators 1 and 2 shown in FIG. 15, the CPU 41 sets the type (address) of the reference data stored in the optimum RAM 3 to be verified.

(Verification)
Next, the collation method will be described in detail with reference to FIG. In the first embodiment, the reading density in the reading width direction is 1872 bits in the case of 300 dpi and 3744 bits in the case of 600 dpi, and any density corresponds to a bill of about 160 mm or less. The number of reading lines is 1280 bits and corresponds to a bill of about 160 mm or less. Here, as shown in FIG. 13B, the CNT terminal (reading density switching terminal) of the sensor 10 is set to 300 dpi, and a total of 1872 bits of photoelectric conversion output in which only odd bits of each pixel operate will be described.

  First, a data signal taken in by turning on the white light source 4a is stored in the RAM 1 having an 1872 × 1280 area, and simultaneously transferred as a digital image signal (SIG) to the reading system for image reference display in real time. Similarly, the data signal captured by turning on the pseudo white light source 6b is stored in the RAM 2 having an 1872 × 1280 area.

  Next, the CPU 41 compares the address data of the RAM1 data and RAM2 data by subtraction processing, and stores the absolute value difference data in the RAM1. Next, the CPU 41 performs a subtraction process, specifies an address with a large change, reduces the data at each address, and stores it in the RAM 2. This is because the read image is the same for both the white light source 4a and the pseudo-white light source 6b, and the data processing other than the hologram area has a similar relationship with different absolute values. . At this time, singular bit processing is performed as described above, and even data smaller than a certain value may be handled as hologram area data. This hologram area data is called a hologram distribution map, specifies the type or candidate of the RAM3 data, and is collated with reference hologram data (collation data) transferred from the RAM3.

  In the difference between the RAM1 data and the RAM2 data captured first, a macro comparison between the RAM1 data and the RAM2 data is performed in the data area corresponding to the both edge portions of the banknote 1, and the RAM1 data obtained with the white light source 4 is simulated. It is preferable to perform address positional deviation correction by rearranging addresses with the RAM 2 data obtained by the white light source 6 to ensure data consistency.

  FIG. 18 shows an example of specific difference data between RAM 1 and RAM 2, and the hologram area is specified by the difference value. In FIG. 18, 35 digit or more is selected as the data of the belt-type hologram area.

  FIG. 19A shows a specific example of a floating island type hologram region. By determining the type of the hologram area, the CPU 41 identifies the type of RAM3 data that matches the appropriate hologram distribution map, transfers the reference hologram data (collation data) of RAM3 to the collation circuit, and sequentially stores the RAM3 data as the RAM2 data. Match.

  Next, the collation will be further described using the floating island type hologram data shown in FIG. FIG. 19B shows data obtained by extracting only floating island type holograms of 35 digits or more. The data stored in the RAM 3 previously set as reference hologram data (collation data) shown in FIG. Match. Here, the capacity of the number of addresses stored in the RAM 2 and the number of data of each address is set larger than the data capacity stored in the RAM 3.

  Next, as shown in FIG. 20, the RAM3 data is transferred to the one-dimensional bidirectional shift register by an A / D signal (address designation signal) for each address, and transferred again to the bidirectional shift register latch unit (latch unit). In the latch unit, the R / L signal (left / right shift signal) is used to check each address of the RAM2 data.

  The RAM2 data is input directly to the cell area logic verification gate circuit composed of only the logic circuit via the shift register by the A / D signal, whereas the RAM3 data is input to the R / L from the CPU 41 a plurality of times. The data in the address is shifted left and right by the signal (sweep). The LA signal (latch signal) is sent for each data shift in the RAM 3 and is verified by the cell area logic verification gate circuit each time. The collation is performed based on the undulation of the data in each address, and as shown in FIG. 21, whether the undulation of the RAM3 (1) data matches the address of the RAM2 data is performed for each RAM2 data address.

  When the RAM (1) data matches the arbitrary address data in the RAM 2, the cell area logic verification gate circuit sends a match signal to the CPU, and the CPU 41 sends the R / L signal to the RAM 2 address by the number of R / L signals sent. Specify the address.

  Next, RAM3 (2) data which is the next address of the RAM3 data is transferred, collated with the next address data of the specified RAM2 address, and if it matches, the cell area logic verification gate circuit sends a match signal to the CPU 41. At this time, the CPU 41 may output a coincidence determination signal to the reading system, but further transfers the RAM3 (3) data, which is the next address of the RAM3 data, and collates with the address data after the specified address of the RAM2, The determination signal may be sent to the reading system after confirming the match.

  In the first embodiment, the digital data in the RAM1 to RAM3 is set to 5 digits for the sake of convenience, but may be 10 digits. When comparing the difference between the white light source 4a and the pseudo white light source 6a, the number of image data stored in the RAM 1 or RAM 2 due to the conveyance deviation of the banknote 1 in the width direction of about 0.1 mm or the variation in the conveyance speed of the banknote 1 is as follows. There are cases where the fetch address for pixels changes. In such a case, the data stored in the RAM 1 and RAM 2 is not an image signal but only a true / false determination signal, so that the averaged data of adjacent bits and the next line is processed as in the case of the singular bit processing described above. May be stored in RAM 1 and RAM 2 so that the discrimination resolution is ¼ and the collation determination is simplified.

  FIG. 22 shows an example in which the output of the sensor 10 is decomposed by spectrum. In FIG. 22, the color of reflected light in the hologram region is mainly red (R) light. Further, in the sensor 10 manufactured by the semiconductor manufacturing process, as shown in the spectral sensitivity curve of the sensor 2 in the visible light region, the higher the optical wavelength, the higher the light receiving sensitivity, so the output value of the sensor 10 is affected by the red light. When a problem occurs in the accuracy of authenticity determination, the image output (SO) is preferably received through an R-Filter shown in FIG. In that case, the reference data stored in the RAM 3 is also stored that is actually measured under the same conditions.

  In the first embodiment, since the high-definition hologram area by laser writing is mainly described, the sensor 10 having a resolution of 300 dpi is used to set the data for each pixel and the digital conversion level of 256 digits (8 bits). In the determination of authenticity of a hologram area using a simple prism or reflector and a printed pattern, the image pattern is not fine, so it may be a digital conversion level of 64 digits (6 bits), and simply changes optically depending on the viewing angle. With a printed pattern hologram, the authenticity can be determined even if a sensor IC having a resolution of about 8 dots / mm is used.

  From the above, by irradiating light at different angles to the irradiation unit installed along the conveyance direction of the banknote 1, it is possible to determine true / false with high accuracy by detecting the difference in the spectrum of reflected light generated in the hologram region. An image reading apparatus can be obtained.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIG. FIG. 23 is a cross-sectional configuration diagram of the image reading apparatus according to the second embodiment. In FIG. 23, 21 is CIS which installed the white light source 4 and the pseudo | simulation white light source 6 on both sides of the irradiation part 3, CIS21a and CIS21b are arranged side by side on the one surface side of the banknote 1, and CIS21c and CIS21d are It is the structure arranged side by side on the other surface side of the banknote 1. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts.

  Next, the configuration will be described. In FIG. 23, two white light sources 4 are mounted on one CIS 21, and the white light source 4 is simultaneously illuminated on the banknote 1 from both sides at the same angle. Similarly, two pseudo white light sources 6 are mounted, and the pseudo white light source 6 is simultaneously illuminated from both sides at the same angle with respect to the banknote 1 at an angle different from that of the white light source.

  From the above, by simultaneously illuminating the banknote 1 from both sides, even if a non-uniform plane occurs on the banknote 1 in the irradiating unit 3 due to a change in the undulation during the conveyance of the banknote 1, the same angle illumination is performed from both sides of one side of the banknote 1 Therefore, compared with the case of irradiating from one side, no shadow is generated on one of the non-uniform surfaces of the banknote 1, the inconvenience due to uneven conveyance of the banknote 1 is eliminated, and the authenticity determination and image reading of the banknote 1 are stable. It becomes possible. The operation / function and the determination method are the same as those described in the first embodiment except that both are turned on simultaneously.

Embodiment 3 FIG.
Embodiment 3 of the present invention will be described with reference to FIG. FIG. 24 is a cross-sectional configuration diagram of the image reading apparatus according to the third embodiment. In FIG. 24, reference numeral 60 denotes a pseudo white light source (second light source) made up of an LED light source, and 70 denotes a black block (first light shielding member) made of a plastic material, and holds the pseudo white light source 60. Reference numeral 80 denotes a second light shielding member made of a plastic material, and is held by a black block. Reference numeral 100 denotes a sensor, 100a denotes a first sensor, 100b denotes a second sensor, 110 denotes a substrate holding the white light source 4 (also referred to as a first substrate), and 120 denotes a sensor substrate on which the sensor 100 is mounted (also referred to as a second substrate). ). 160 is an input / output connector (external connector) for passing signals, 170 is a transparent body having two irradiation units 3, 210 is a CIS, 210a is a CIS disposed on one side of the banknote 1, and 210c is It is CIS arrange | positioned on the other surface side of the banknote 1. FIG. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

Next, the configuration will be described. In FIG. 24, two lens arrays 9 a and 9 b are mounted on one CIS 210, and two irradiation units 3 are provided corresponding to each lens array 9. The banknote 1 that has been conveyed is first illuminated by the white light source 4 with the banknote 1 positioned at the irradiation unit 3a, and the reflected light is focused by the lens array 9a and received by the sensor 100a. Further, when the banknote 1 reaches the irradiation unit 3b, the pseudo white light source 60 illuminates the banknote 1 located on the irradiation unit 3b, and the reflected light is focused by the lens array 9b and received by the sensor 100b.
Note that the CIS 210c operates independently in the same manner as the CIS 210a.

  FIG. 25 is a plan view of the transmissive body 170 mounted on the CIS 210, and 170 w is two openings provided in the transmissive body 170. The irradiation unit 3a and the irradiation unit 3b are located along the opening 170w.

  As described above, the white light source 4 and the pseudo-white light source 60 are mounted on one CIS 210, and one is obtained by irradiating the irradiation unit 3 with light at different irradiation angles provided at different positions along the transport direction. The authenticity of the hologram can be determined by the CIS 210. Further, since the external housing is integrated as compared with the first embodiment or the second embodiment, the number of signal processing ICs such as a control line for exchanging signals and a comparison / collation circuit is expected to be reduced. Become.

  DESCRIPTION OF SYMBOLS 1 Object to be irradiated (banknote), 2 Conveyance means (conveyance roller), 3 Irradiation part, 4 First light source (white light source), 5 Reflector, 6 Second light source (pseudo white light source), 7 Light emission part (emission part) ), 8 cover, 9 lens array (rod lens array), 10 sensor (light receiving part), 11 sensor substrate, 12 signal processing IC (ASIC), 13 substrate, 14 electronic component, 15 relay connector, 16 external connector, 17 transmission Body, 17w groove (opening), 22 holder, 23 screw, 24 system cradle, 25 screw, 30 detection means (photo sensor), 31 stay, 32 cassette, 33 cassette base (banknote base), 34 transport roller, 40 Light source drive circuit, 41 CPU, 42 amplifier, 43 analog-digital converter (A / D converter), 4 comparison circuit, 45 collation circuit, 60 second light source (LED light source), 70 light shielding member (first light shielding member), 80 light shielding member (second light shielding member), 100 sensor, 100a first sensor, 100b second sensor, 110 substrate (first substrate), 120 sensor substrate (second substrate), 160 external connector, 170 transmission body, 170w groove (opening), 210 image sensor (CIS).

Claims (2)

A transport means for transporting an irradiated object having a hologram area in a part of at least one reading line in the main scanning direction in the transport direction, and detecting a passage of the irradiated object through the hologram area and outputting a detection signal; Hologram detection means, which is a plurality of sensors arranged along the scanning direction, and a hologram area of the object irradiation object conveyed by the conveyance means from the detection signal output from the hologram detection means is inserted into the first irradiation section. A first light source that is a white light source that irradiates light to the first irradiation unit in the hologram area at a timing to be applied, and is separated from the first light source along the transport direction. Is a white light source for irradiating light to the second irradiation part in the hologram region when transported by a predetermined distance from the first irradiation part A light source, an irradiation angle at which the light from the first light source is applied to the first irradiation unit, and a light from the second light source when the hologram region is transported from the first irradiation unit by a predetermined distance. Configured to be different from the irradiation angle irradiated to the second irradiation unit, arranged along the main scanning direction, through the rod lens array having an optical axis perpendicular to the transport direction, depending on the irradiated object , Receiving the light emitted from the first light source and the reflected light of the light emitted from the second light source , respectively, detects an electrical signal related to the hologram area of the irradiated object, and the hologram area in these electrical signals An image reading apparatus that performs level adjustment of the electrical signals by using similar waveforms in other parts. A transport means for transporting an irradiated object having a hologram area in a part of at least one reading line in the main scanning direction in the transport direction, and detecting a passage of the irradiated object through the hologram area and outputting a detection signal; Hologram detection means, which is a plurality of sensors arranged along the scanning direction, and a hologram area of the object irradiation object conveyed by the conveyance means from the detection signal output from the hologram detection means is inserted into the first irradiation section. A first light source that is a white light source that irradiates light to the first irradiation unit in the hologram area at a timing to be applied, and is separated from the first light source along the transport direction. Irradiates the second irradiator in the hologram area with light from the first illuminator when the first irradiator is transported a predetermined distance from the first irradiator, Provided to be different from an irradiation angle at which the second irradiation unit is irradiated with light when the hologram region is transported by a predetermined distance from the first irradiation unit with respect to an irradiation angle at which the first irradiation unit is irradiated. A second light source that is a white light source and an optical axis that is disposed along the main scanning direction and is perpendicular to the transport direction, and the light from the first and second light sources is the first light source in the hologram region. It is reflected by the first and second irradiation portions, and first and second rod lens array for converging the reflected light, respectively, through the first and second rod lens array, due to the irradiated object, the first the light emitted from the light source, and the reflected light of light emitted from the second light source respectively received to detect an electric signal of the hologram area of the irradiated member, the hologram territory in these electrical signals An image reading apparatus using the waveform of the portions other than to similar performing level adjustment of the electrical signals to each other.

Images