JP5377397B2 - Paper sheet identification device, paper sheet identification method, and paper sheet identification program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper sheet identification apparatus capable of reducing an image transfer amount upon picking up an image with high resolution and also reducing capacity of an image memory without compressing a bus band. <P>SOLUTION: The paper sheet identification apparatus comprises: a one-dimensional image sensor 11 which picks up an image of a paper sheet 30; a line buffer 12 which temporarily stores the image picked up by the image sensor 11; a step S13 of transferring image data with low resolution based on image data of the line buffer 12; steps S27 and S28 of determining areas A0, A1, B0, B1 to which image data with high resolution of the image obtained by picking up the paper sheet 30 based on the image data of the line buffer 12 is transferred; and a step S28 of transferring the image data with high resolution for the areas A0, A1, B0, and B1 in the image data of the line buffer 12. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a paper sheet identification device, a paper sheet identification method, and a paper sheet that need to capture and process a high-resolution image, for example, by recognizing a serial number printed on the paper sheet. Class identification program.

  2. Description of the Related Art Conventionally, in a bill identifying device for identifying a bill that is a type of paper sheet, a device for identifying a serial number using a low resolution sensor and a high resolution sensor has been proposed (see Patent Document 1).

  This patent document 1 is a system in which the short side of a bill is conveyed in a direction perpendicular to the conveyance direction, such as a bill identification device used in a vending machine. For this reason, in countries where the short length is constant regardless of the denomination like Japan, the passage position of the serial number can be easily fixed by adjusting the width of the slot to the short length. Can do.

  On the other hand, in the method of transporting the banknotes in the direction perpendicular to the transport direction, such as the banknote identification apparatus used in an automatic transaction apparatus (ATM) installed in a financial institution, the length of each denomination is long. The length of is different. For this reason, it is necessary to set the conveyance path width to be longer than the longitudinal length of the longest denomination. Then, when the denomination with the shortest length is conveyed, the passage position of the banknote on the conveyance path varies. For this reason, a high-resolution sensor that covers the entire passage width must be mounted.

  As described above, in the method of transporting the bill in the direction perpendicular to the transport direction, when a high resolution sensor and a low resolution sensor are attached, the high resolution sensor is also large, and two similar sensors are mounted. There is a problem that the cost becomes high.

  In addition, when a large sensor is mounted and the entire conveyance path width is imaged, there is a problem that a large amount of image memory is required and the cost is increased. There is a problem that the bus bandwidth becomes insufficient.

Japanese Patent Laid-Open No. 10-154256

  In view of the above-described problems, the present invention provides a paper sheet identification apparatus, paper that can capture a high-resolution image, reduce the image transfer amount, do not compress the bus bandwidth, and reduce the capacity of the image memory. An object is to provide a leaf identification method and a paper sheet identification program.

  The present invention relates to a one-dimensional imaging unit that captures an image of a paper sheet, a line buffer that temporarily stores an image captured by the imaging unit, and a low-resolution image based on the image data of the line buffer. Low-resolution transfer means for transferring image data; and high-resolution area determination means for determining a high-resolution area for transferring high-resolution image data among images obtained by imaging the paper sheets based on the image data of the line buffer; It is a paper sheet identification device provided with a high resolution transfer means for transferring high resolution image data for the high resolution area in the image data of the line buffer.

  According to the present invention, after capturing a high-resolution image, the image transfer amount can be reduced, the bus bandwidth can be reduced, and the capacity of the image memory can be reduced.

The block diagram which shows schematic structure of the paper sheet processing apparatus carrying a paper sheet identification device. The block diagram which shows the functional structure of a paper sheet identification device. The top view which shows the external appearance of paper sheets. The side view which shows the operation | movement at the time of imaging of paper sheets. Explanatory drawing of a thinning process (resolution reduction process). A timing chart showing transfer timing. The block diagram of the link buffer which stores the medium length for every line. The flowchart of a low resolution transfer process. The flowchart of a high resolution transfer process. Area explanatory drawing explaining a high resolution area | region and a low resolution area | region. Explanatory drawing of medium length.

  An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing a schematic configuration of a paper sheet processing apparatus 1 equipped with a paper sheet identification device 8 as a computer.
The entrance / exit 2 of the paper sheet identification device 8 is an opening through which an operator inputs and receives paper sheets. The paper sheet identification device 8 identifies the authenticity or denomination of the conveyed paper sheet and outputs the identification result. The temporary holding unit 3 temporarily holds a paper sheet that has been input by the operator in the deposit process and whose paper sheet identification device 8 has been able to identify authenticity, denomination, and the like.

  The storage units 4A, 4B, and 4C store paper sheets that are determined to be genuine by the paper sheet identification device 8 and denominated. The collection unit 5 stores paper sheets whose denomination could not be determined by feeding from the temporary storage unit 3, paper sheets whose denomination could not be determined by feeding from the storage units 4A, 4B, and 4C. Yes.

  The cassette 7 stores paper sheets to be replenished in the storage units 4A, 4B, and 4C, and paper sheets collected from the storage units 4A, 4B, and 4C. The replenishment collection unit 6 stores paper sheets whose denominations cannot be determined among paper sheets fed from the cassette 7. Each of the above portions is connected by a conveyance path 9, and the sheets are conveyed one by one through the conveyance path 9.

FIG. 2 is a block diagram showing a functional configuration of the paper sheet identification device 8.
The CPU 14 controls the paper sheet identification device 8 as a whole. The ROM 15 is a non-volatile memory, and stores a control program used by the CPU 14, a paper sheet identification program, and the like. The RAM 16 is a volatile memory and stores variables used by the CPU 14.

  The image sensor 11 is a one-dimensional sensor that captures an image of a paper sheet. The line buffer 12 is a memory that temporarily stores one-dimensional image data captured by the image sensor 11. There are a total of four line buffers 12, and images for one line from the image sensor are sequentially stored. Starting from the line buffer # 0, next to the last line buffer # 3, the process returns to the first line buffer # 0 and is stored in order.

  The image memory 17 is a memory for storing a high-resolution image and a low-resolution image of paper sheets. The image transfer unit 13 refers to the line buffer 12 and transfers part of the high-resolution image data 23 and the entire low-resolution image data 24 to the image memory 17, and combines the high-resolution image data 23 with the high-resolution image data 23. The position information and length information of the image data are also transferred.

  In addition to the image sensor, the paper sheet identification device 8 includes a sensor 18 such as a magnetic sensor or a thickness sensor, and sensor data is transferred from each sensor 18 to each sensor memory 20 by a sensor transfer unit 19.

  Each device is connected to the bus 10. The bus 10 is a signal line used in common. The bus 10 is used when transferring image data to the image memory 17, when transferring sensor data of the sensor 18 to the sensor memory 20, or when the CPU 14 accesses data or programs stored in the ROM 15 or RAM 16. Is called.

  With this configuration, the paper sheet identification device 8 stores the image data captured by the image sensor 11 in the line buffer 12 and transfers and stores the image data in the image memory 17 by the image transfer unit 13, and sensor data of other sensors 18. Is transferred to and stored in the sensor memory 20 by the sensor transfer unit 19, and the CPU 14 performs identification processing of the paper sheet 30 such as denomination determination and authenticity determination based on the image data in the image memory 17 and the sensor data in the sensor memory 20. Execute. The CPU 14 that executes the identification process functions as an identification unit that identifies paper sheets based on the high-resolution image data 23, the low-resolution image data 24, and the like.

FIG. 3 is a plan view showing the appearance of the paper sheet 30.
Here, the paper sheets include at least banknotes, checks, securities, and gift certificates. In this embodiment, an example of a paper sheet 30 in the image of a banknote will be described.

  On the surface of the paper sheet 30, serial numbers 31A and 31B are printed in at least two places. In FIG. 3, the combination of alphanumeric characters is used, but the serial number is not limited to alphanumeric characters and may include a symbol that can identify the paper sheet 30. Here, the areas near the serial numbers 31A and 31B are the areas 32A and 32B to be noted.

FIG. 4 is a side view showing an operation at the time of imaging a paper sheet.
The paper sheet 30 is conveyed in the direction of the direction A shown in the drawing. The lamp 40A irradiates the entire upper surface of the paper sheet 30, and the image sensor 11A receives the light reflected from the paper sheet 30. The image data read from the image sensor 11A is for one line, but since the images are sequentially taken as the paper sheet 30 is conveyed, a two-dimensional image can be obtained as a result.

  Also on the lower surface of the paper sheet 30, a two-dimensional image can be obtained by the lamp 40B and the image sensor 11B in the same manner as the upper surface. In FIG. 2, only one set of the image sensor 11, the line buffer 12, and the image transfer unit 13 is illustrated, but two sets are actually connected to the bus 10.

  The paper sheet 30 is configured such that the length in the conveyance width direction is shorter than the conveyance path width of the conveyance path 9. For this reason, a skew (inclination) of the paper sheet 30 occurs during conveyance on the conveyance path 9.

  Japanese banknotes have a serial number printed on only one side and no serial number printed on the other side, so you can't tell which side will be transported up, An imaging system (lamps 40A and 40B and image sensors 11A and 41B) is arranged on the upper side and the lower side, but in an apparatus that handles paper sheets with serial numbers printed on both sides, the imaging system is arranged only on one side. May be. In addition, even in a device that handles paper sheets with serial numbers printed on only one side, such as Japanese banknotes, the imaging system may be arranged on only one side when the paper sheet side can be fixed and handled.

FIG. 5 is an explanatory diagram of thinning processing (resolution reduction processing).
First, image data for one line imaged by the image sensor 11 is sequentially stored in the four line buffers 12. After the last line buffer # 3, the data is stored back to the first line buffer # 0. As a result, the correspondence between the line numbers captured by the image sensor and the line buffer numbers is as follows: the line numbers are # 0, # 1, # 2, # 3, # 4, # 5, # 6, and # 7. While the number increases by 1, the line buffer number circulates through # 0, # 1, # 2, # 3, # 0, # 1, # 2, # 3 and functions as a ring buffer.

Each pixel of the image captured by the image sensor 11 is represented as Pnm. Here, n represents the line number of the image sensor and corresponds to the transport direction. M represents the number of each image sensor of the image sensor, and corresponds to the conveyance path width direction.
This collection of Pnm becomes the high-resolution image data 23.

  The thinning-out process is a process for reducing the data amount by reducing the resolution. Here, a total of 16 pixels corresponding to 4 lines in the transport direction and 4 pixels in the transport path width direction are converted into one pixel. . As a conversion method, a value obtained by an appropriate calculation method such as simply using an average value of 16 pixels or using a median value of 16 pixels is used. In FIG. 5, for example, conversion from 16 pixels of P00, P01, P02, P03, P10, P11, P12, P13, P20, P21, P22, P23, P30, P31, P32, and P33 to one pixel. Is shown.

  Here, 4 lines × 4 pixels are defined as one block, but any combination other than 1 line × 1 pixels may be used. For example, one line × 4 pixels or four lines × 1 pixels may be used. In this case, the number of line buffers may be changed as the number of lines is changed.

FIG. 6 is a timing chart showing the transfer timing.
When the image sensor 11 sequentially captures an image for one line, the image is stored in the line buffer 12. This timing T1 is shown in the figure as line numbers 0, 1,.

  The high resolution transfer is executed every time image data for one line is stored in the line buffer 12. That is, high-resolution transfer is performed at a timing T2 that has a one-to-one correspondence with a timing T1 at which the image sensor 11 captures an image for one line and stores it in the line buffer 12. In this high-resolution transfer, only a portion that requires high-resolution image processing from one line of image data is transferred to the image memory 17 by the transfer unit 13. In this embodiment, only the portion considered to be a serial number area is transferred, but other attention areas such as micro characters may be transferred. Details of this high resolution transfer process will be described later.

  The low resolution transfer is executed at every timing T3 when the image data is stored in the line buffer # 3. The low-resolution image data 24 transferred at this time is low-resolution image data in which the resolution is reduced to 1/4 in the transport direction and 1/4 in the transport path width direction. The low-resolution image data 24 is transferred to the image memory 17 by the image transfer unit 13. Details of the low resolution transfer process will be described later.

FIG. 7 is a configuration diagram of the link buffer 21 that stores the medium length for each line obtained by photographing the paper sheet 30 by the image sensor 11.
The link buffer 21 can store a total of four medium lengths, and the counter C manages where the medium lengths should be stored. That is, the value of the counter C indicates the number of the link buffer 21. The link buffer 21 is paired with the line buffer 12 and both are configured to store data for four lines.

FIG. 8 is a flowchart of the low-resolution transfer process executed by the paper sheet identification device 8 based on the paper sheet identification program.
As described with reference to FIG. 6, the low-resolution transfer process is performed once every four lines and transfers an image with a reduced resolution. The transferred low-resolution image data 24 is used in processing that requires image data of the entire medium, such as denomination discrimination.

  The paper sheet identification device 8 waits for the image sensor 11 to complete the imaging for one line (imaging step) and to store the image data in the line buffer 12 (primary storage step) (step S10: not yet). . When the storage in the line buffer 12 is completed (step S10: end), the paper sheet identification device 8 checks whether the storage in all the line buffers 12 is completed (step S11). If the sheet identification device 8 has not yet been stored in all line buffers (step S11: No), the process returns to step S10, and if the storage in all line buffers 12 has been completed (step S11). S11: Yes), the process proceeds to the next step.

  As described with reference to FIG. 6, the paper sheet identification device 8 performs a thinning process for reducing the resolution to one pixel every 4 lines × 4 pixels (step S <b> 12), and generates the low-resolution image data 24 created thereby. A low resolution transfer step of transferring to the image memory 17 is performed (step S13).

  The paper sheet identification device 8 confirms whether or not the thinning process has been completed for all the pixels (step S14). If not completed yet (step S14: incomplete), the process returns to step S12 to thin out the next pixel. Perform processing. If completed (step S14: completed), the paper sheet recognition apparatus 8 advances the processing to the next step.

  The paper sheet identification device 8 confirms whether or not the imaging process has been completed last (step S15), and if not completed yet (step S15: No), the process returns to step S10, and the image data of the next line is obtained. Storage processing, thinning-out processing, and transfer processing are performed. If completed (step S15: Yes), the paper sheet identification device 8 ends the low resolution transfer process.

  FIG. 9 is a flowchart of the high-resolution transfer process executed by the paper sheet identification device 8 based on the paper sheet identification program. FIG. 10 illustrates the high-resolution area and the low-resolution area in the read paper sheet image. FIG. 11 is an explanatory diagram of a medium length that can be recognized by image reading by the image sensor 11.

  As described with reference to FIG. 6, the high resolution transfer process is performed for each line, and only the area including the serial number areas 32A and 32B is transferred to the image memory 17 while maintaining the high resolution. However, an image that is transferred at a high resolution as a two-dimensional image in the high resolution area is not only the vicinity of the serial number areas 32A and 32B of the paper sheet 30 described in FIG. 3, but also a vertically long image such as B0 and B1 shown in FIG. The area is Since the position of the serial number in the transport direction differs depending on whether the paper sheet 30 is inserted in the front or back direction, the image is acquired over the entire front and rear in the transport direction. Since the serial number is located from the front or rear of the paper sheet 30 in the transport direction, it is possible to adopt a configuration excluding the central position in the transport direction of the regions B0 and B1.

  The transferred high resolution image data 23 is used in a process that requires a high resolution image with a fine pattern such as serial number recognition. This high resolution transfer process is executed in parallel with the above-described low resolution transfer process.

  The paper sheet identification device 8 first clears the counter C to 0 (step S20). This counter C is for managing the position for storing the medium length L for each line.

  Wait until the image sensor 11 completes imaging for one line and stores it in the line buffer 12 (step S21: incomplete). If completed (step S21: completed), the process proceeds to the next step.

  The paper sheet identification device 8 refers to the image data stored in the line buffer 12 and calculates the medium length L (step S22). In this calculation, for example, all pixels in one line are binarized, the left end and the right end of the medium are obtained, and the medium length L is obtained from the difference between the right end position and the left end position.

  The paper sheet identification device 8 stores the medium length L calculated in step S22 in the ring buffer at the position indicated by the counter C (step S23). The paper sheet identification device 8 updates the value of the counter C to the next value for the processing of the next line (step S24). The updating of the counter C is executed by a bit operation that performs AND with 3. As a result, the counter C is incremented by 1 from 0, such as 0, 1, 2, 3, 0, 1,. repeat.

  The paper sheet identification device 8 checks the medium length L calculated in step S23 (step S25). If the medium length L is 0 (step S25: Yes), since there is no medium yet, the transfer process is not performed and the process returns to step S21. If the medium length L is not 0 (step S25: No), since the medium has arrived, the paper sheet identification device 8 proceeds to the next step in order to perform the transfer process.

  The paper sheet identification device 8 calculates the DIF in order to determine whether the current line is the leading edge (area A0), the trailing edge (area A1), or the middle (area B) of the medium. (Step S26).

Here, DIF is the sum of absolute values of the differences between the media lengths L of adjacent lines, and is obtained by the following equation 1.
<Formula 1>
DIF = | L0-L1 | + | L1-L2 | + | L2-L3 |

  Here, a determination method for determining the front end portion, the rear end portion, and the intermediate portion of the paper sheet 30 using the DIF will be described. As shown in FIG. 10, the leading end portion of the paper sheet 30 corresponds to the region A <b> 0 in FIG. 10, the rear end portion corresponds to the region A <b> 1, and the intermediate portion corresponds to the region B of the paper sheet 30. That is, the paper sheet 30 transported in the short direction is skewed (inclined) as illustrated in the transport path 9 having a transport path width wider than the length of the paper sheet 30 in the transport width direction. There are a front end portion and a rear end portion in which the length of the medium sequentially read by the image sensor 11 greatly fluctuates for each line before and after the intermediate portion that can be read by the image sensor 11 to both ends (full width) of the paper sheet 30 in the conveyance width direction. Exists. In the regions A0 and A1 which are the leading end portion and the trailing end portion, the medium length La changes greatly for each line, so the DIF becomes a large value. On the other hand, in the central portion excluding the areas A0 and A1 in the paper sheet 30 in FIG. 10, the medium length Lb for each line is stable and does not change so much, so the DIF becomes a small value. Therefore, if the DIF is small, it can be determined that the center portion is present, and if the DIF is large, it is possible to distinguish the tip portion or the rear end portion. According to this DIF method, even when a plurality of types of paper sheets 30 having different medium lengths in the conveyance width direction are identified, the front end portion, the rear end portion, and the intermediate portion can be separated without any problem.

  It should be noted that the front end portion, the rear end portion, and the central portion are not limited to the method using the DIF, and other methods can be employed. For example, if the medium length L is less than a certain threshold value (predetermined reference value), the leading edge or the trailing edge may be used.

  The paper sheet identification device 8 compares the DIF with a predetermined threshold value (predetermined reference value) (step S27). If the DIF as the predetermined criterion satisfies the criterion that the DIF is smaller than the threshold value (step S27: Yes), the paper sheet identification device 8 determines that it is the central portion of the medium, and the serial number area in the paper sheet 30 Only the area corresponding to 32A, 32B is transferred (step S28). Specifically, the high-resolution image data 23 in the areas B0 and B1 shown in FIG. 10 is transmitted.

  Here, step S28 is a transfer process when it is determined that the center portion, and only the area corresponding to the serial number area is transferred. For this reason, as shown in FIG. 10, as a predetermined condition, only those corresponding to the condition for n pixels are transferred from a position which is inward by m pixels from the left end and the right end of the paper sheet 30. That is, the areas corresponding to B0 and B1 in FIG. 10 are transferred. At this time, for the image processing to be performed later, the start position and the length of each of the areas B0 and B1 in the transport width direction are also transferred. In region B0 shown in FIG. 10, start point = x0 + m and length = n, and in region B1, start point = x0 + m + n + k and length = n.

The method for calculating the position and length of the transfer area may be obtained as a ratio to the medium length L.
In this embodiment, there are two transfer areas in the central part because the serial numbers are in two symmetrical positions, and the serial number is only in one central part in the conveyance path width direction. In the case where they are arranged, only one transfer area is required.

  If the DIF is greater than or equal to the threshold value (step S28: No), it is determined that it is the leading edge or trailing edge of the paper sheet 30, and only the medium portion (areas A0 and A1 shown in FIG. 10) is used as the high resolution area. A high resolution image is transferred (step S29).

  Here, this step S29 is a transfer process when it is determined that the front end portion or the rear end portion, and the entire area of the front end portion and the rear end portion is transferred. As shown in FIG. 3, since the serial number is printed near the front end and the rear end, the serial number is highly likely to be included in the front end area A0 and the rear end area A1 in FIG. Therefore, in this embodiment, in the case of the front end portion or the rear end portion, the entire area of the medium is transferred. At this time, similar to step S28, the transfer area start position and length are also transferred. Therefore, start position = media left end coordinate, length = La.

  The determination in step S27 and the extraction of the necessary part in step S28 become the high resolution area determination step, and the transfer in step S28 and the transfer in step S29 become the high resolution transfer step.

  In this embodiment, transfer is also performed at the front end and the rear end. However, when the attention area such as a serial number is only at the center of the medium, the attention area does not enter the front end or the rear end. Therefore, it is only necessary not to transfer at the front end portion or the rear end portion.

  In this embodiment, the start position and length data are transferred together with the image data. However, if it is desired to reduce the transfer capacity but the image memory itself can be mounted with a large capacity memory, the start position and length data are transferred. The image data may be transferred without transferring the image data.

  Finally, the paper sheet identification device 8 confirms whether the imaging process has been completed (step S30). If it has not been completed yet (step S30: No), the process returns to step S21 to perform the process for the next line. If completed (step S30: Yes), the high resolution transfer process is terminated.

The low resolution transfer process and the high resolution transfer process executed in this way are executed in parallel as described above, but the timing of performing the main process is different.
That is, in the low resolution transfer process, the decimation process (step S12) and the transfer process (step S13) are executed at the stage when the image data is stored in all the four line buffers 12 from # 0 to # 3, and # 0 is again performed. When the image data is stored from the line buffer 12 and proceeds to # 3, thinning processing and transfer are executed. Therefore, every time imaging is performed four times by the image sensor 11, thinning processing and transfer are performed.

  On the other hand, each time image data is stored in one line buffer 12, the high resolution transfer process is performed with an edge / intermediate part determination process (step S27), a transfer area extraction process (step S28), and a transfer process (step S28, 29) is executed.

  Therefore, when the main processing (steps S27 to S29) of the high resolution transfer processing is executed four times, the main processing (steps S12 to S13) of the low resolution transfer processing is executed once.

  By this high resolution transfer processing and low resolution transfer processing, the amount of data to be transferred can be made smaller than when the entire high resolution data of the paper sheet 30 is transferred. As a result, the bus bandwidth is not compressed during the transfer of the image data, and the memory capacity of the image memory 17 for storing the transferred image data can be reduced.

  With the above configuration and operation, it is possible to provide the paper sheet identification device 8 that reduces the image transfer amount, does not impose a bus bandwidth, and reduces the memory capacity of the image memory 17. Specifically, as a general image process, extraction of a region of interest and resolution reduction are performed after all image data is temporarily stored in an image memory. Such a method requires a large-capacity image memory, and may cause a problem that the bus bandwidth is insufficient at the time of transfer to the image memory. On the other hand, the above-described paper sheet identification device 8 stores all pixel image data in the line buffer 12, and partially extracts high-resolution image data 23 from the pixel data or the entire low-resolution image subjected to the thinning process. By transferring the data 24 to the image memory 17, the total transfer capacity can be suppressed.

  Further, since the area to which the high-resolution image data 23 is transferred is determined based on the medium length L in the conveyance width direction of the paper sheet 30 that can be determined by the one-dimensional image sensor 11, Transfer of high-resolution image data 23 extracted in part can be realized without acquiring image data. For this reason, image processing can be executed with much less information than when the entire image data of the paper sheet 30 is handled.

  Since a plurality of line buffers 12 are provided, the image data can be transferred to the image memory 17 after the resolution of the image data is reduced in the transport direction. In this embodiment, since four line buffers 12 are provided, the image data for four pixels in the transport direction can be reduced to one pixel and transferred to the image memory 17.

  Whether the edge / intermediate portion of the paper sheet 30 is determined (determination between the leading edge portion, the trailing edge portion, and the intermediate portion) is the difference between the medium lengths L acquired in order by the image sensor 11 is equal to or less than a predetermined threshold value. Therefore, the edge / intermediate portion can be determined for a plurality of types of paper sheets having different medium lengths L.

  Further, since the areas A0 and A1 at the front end and the rear end of the paper sheet 30 are all configured to transfer the high-resolution image data 23, the degree of skew is strong and the serial numbers are assigned to the areas A0 and A1. However, this serial number can be identified by the high-resolution image data 23.

  Further, when transferring the high-resolution image data 23 partially extracted from the intermediate part, the CPU 14 transfers the extracted image data along with the start position and the length in the transport width direction. It is possible to reproduce whether the image data of the area. Thereby, it is possible to easily identify an appropriate paper sheet 30.

  If the transfer amount when the resolution is not reduced and the area is not extracted is 1, in the above-described embodiment, the low resolution transfer portion is 1/16 of the original, and the high resolution transfer portion is approximately the original 5 / 8 or so (however, it depends on how much the serial number area is expected). Therefore, the image transfer amount can be suppressed to about 11/16 in total for the low resolution transfer and the high resolution transfer.

  The present invention is not limited only to the configuration of the above-described embodiment, and many embodiments can be obtained.

  The present invention can be used to identify paper sheets such as banknotes, checks, securities, and gift certificates.

8 ... Paper sheet identification device, 11, 11A, 11B ... Image sensor, 12 ... Line buffer, 23 ... High resolution image data, 24 ... Low resolution image data, 30 ... Paper sheets, A0, A1, B, B0, B1 ... area

Claims (7)

One-dimensional imaging means for capturing an image of a paper sheet;
A line buffer for temporarily storing an image captured by the imaging means;
Low resolution transfer means for transferring low resolution image data based on the image data of the line buffer;
High-resolution area determination means for determining a high-resolution area for transferring high-resolution image data among images obtained by imaging the paper sheets based on the image data of the line buffer;
A paper sheet identification apparatus comprising: a high-resolution transfer unit configured to transfer high-resolution image data for the high-resolution area in the image data of the line buffer. The high resolution region determining means includes
2. The paper sheet identification apparatus according to claim 1, wherein image data obtained by imaging a paper sheet to be conveyed is divided into a conveyance end portion and an intermediate portion, and the high resolution area is determined for each portion. The high resolution region determining means includes
For the transport end, determine whether to set each high resolution area,
The paper sheet identification apparatus according to claim 2, wherein the intermediate part is configured to determine a part of the area according to a predetermined condition as a high resolution area. The high resolution region determining means includes
If the paper width in the transport width direction does not meet the predetermined standard,
The paper sheet identification apparatus according to claim 2 or 3, wherein the intermediate portion is set while the predetermined standard is satisfied. 5. The paper sheet identification apparatus according to claim 1, wherein the high-resolution transfer unit is configured to transfer the position information and length information of the image data together with the high-resolution image data. . An imaging step of capturing an image of a paper sheet by a one-dimensional imaging means;
A primary storage step of temporarily storing an image captured by the imaging means in a line buffer;
A low-resolution transfer step of transferring low-resolution image data based on the image data of the line buffer;
High resolution region determination step of determining a high-resolution area to transfer high resolution image data of the Chi sac image taken the paper sheet based on the image data of the line buffer,
A paper sheet identification method comprising: a high resolution transfer step of transferring high resolution image data for the high resolution area in the image data of the line buffer. Computer
One-dimensional imaging means for capturing an image of a paper sheet;
A line buffer for temporarily storing an image captured by the imaging means;
Low resolution transfer means for transferring low resolution image data based on the image data of the line buffer;
And a high-resolution area determining means for determining a high-resolution area to transfer high resolution image data of the Chi sac image taken the paper sheet based on the image data of the line buffer,
A paper sheet identification program that functions as a high-resolution transfer unit that transfers high-resolution image data for the high-resolution area in the image data of the line buffer.

Images