JP4411058B2 - Fingerprint reader - Google Patents

Description

  The present invention mainly relates to a fingerprint reading apparatus including a fingerprint reading sensor using a sweep type capacitive sensor capable of reading a fingerprint pattern on a fingertip as a fingerprint image image in accordance with a rotation operation of a rotating roller. The present invention relates to a power-saving fingerprint reader that can suppress fingerprint power consumption in a standby state as much as possible and enables accurate fingerprint detection.

  2. Description of the Related Art Conventionally, several types of fingerprint readers (see Patent Documents 1 to 4) are known as fingerprint readers capable of detecting a fingerprint in accordance with a rotation operation of a rotary roller.

  In these fingerprint readers, the fingerprint reader sensor for detecting the fingerprint pattern is composed of a combination of an optical element including a light source and an imaging unit, and these are arranged separately. There is a problem that the number of parts increases and an occupied space is required.

On the other hand, as a fingerprint reading sensor that can counter these problems, a capacitance matrix is provided so that the contour of the undulation line of the fingerprint obtained during relative movement when the finger is directly touched and slid can be provided. It is equipped with a sweep type capacitive sensor that acquires fingerprint image data from a partial image obtained by a sensitive element composed of a capacitance element that enables pattern sensing, and reconstructs the image of the fingerprint image data. A structure capable of detecting a fingerprint pattern (see Patent Document 5) has also been developed.
JP 2001-184490 A (summary) JP 2001-283206 A (summary) JP 2002-133402 (Abstract) JP 2002-517835 (summary) JP-A-10-91769 (Summary, Claims [Claim 1], [Claim 7], [Claim 15])

  In the case of the fingerprint reading device according to Patent Document 5 described above, the use of the sweep type capacitance sensor has an advantage that it is smaller and simpler than those of other types according to Patent Documents 1 to 4. On the other hand, the configuration using a single sensor that does not involve the rotating operation of the rotating roller may cause the fingerprint reading direction to be oblique, and in this case, it is difficult to stably obtain a good fingerprint image. In addition, in any of the fingerprint reading devices according to Patent Documents 1 to 5, in order to obtain a state in which the fingerprint reading sensor can read a fingerprint, each part is always energized while the entire device is turned on. In order to obtain the status, the dedicated switch for starting the application is turned on, and then each part is energized to supply power. Who it takes the power consumption in the standby state is not performed rotating operation of the rotary roller, there is a problem that it can not aim a sufficient power saving reduction in functionality.

  In any of the fingerprint reading devices according to Patent Documents 1 to 5, in order to synthesize a part of the fingerprint image data obtained by the fingerprint reading sensor, the amount of finger movement is calculated based on the fingerprint image data. The calculation result of the movement amount is used for reconstruction of the fingerprint image, but the number of times of examining duplicate images increases due to the influence of slipping when the finger moves, and it takes considerable time for the calculation process, There is also a drawback that the efficiency of the fingerprint image reconstruction process does not increase, and as a result, the image process takes too much time.

  The present invention has been made to solve such problems, and its technical problem is that power consumption in a standby state can be suppressed as much as possible, and a fingerprint image can be reconstructed efficiently and fingerprint detection can be performed. An object of the present invention is to provide a power-saving fingerprint reader that can be stably and quickly performed with high accuracy.

  According to the present invention, when the rotating roller used for the rotating operation and the rotating roller are disposed in the vicinity of the rotating roller and are subjected to the moving contact by the fingertip of the person who is the subject in accordance with the rotating operation of the rotating roller. A fingerprint reading unit including a fingerprint reading sensor that obtains fingerprint image data by reading a fingerprint pattern on the fingertip, and one of the fingerprint image data according to a result of calculating a movement amount of the finger based on the fingerprint image data. In a fingerprint reading apparatus comprising: an image processing arithmetic unit that performs image processing for combining and reconstructing the units; and a storage device that stores at least data necessary for image processing on fingerprint image data. A rotation detection unit that detects a rotation direction and a rotation amount, and the image processing calculation unit is configured to detect a fingerprint pattern by a fingerprint reading sensor after the rotation detection unit confirms the rotation of the rotation roller. Image processing calculation control for controlling the amount of duplication when combining fingerprint image data based on a period corresponding to the amount of rotation of the rotating roller as image processing. The fingerprint reader which is a part is obtained.

  According to the present invention, in the fingerprint reader, the storage device includes a program storing a program for image processing, and the image processing calculation control unit performs drive control and duplication amount according to the program read from the storage device. A fingerprint reading device that performs the above control is obtained.

  Furthermore, according to the present invention, in any one of the above-described fingerprint readers, a rotation period counting unit for counting and holding the period based on the rotation amount of the rotation roller is provided, and the image processing calculation control unit includes the rotation period. A fingerprint reading apparatus is obtained that calculates and estimates the magnitude of slipping during movement by the fingertip based on the period read from the counting unit, and controls the amount of overlap based on the magnitude of the slipping.

  In addition, according to the present invention, in any one of the fingerprint readers described above, the rotation detection means is included in the fingerprint reader and is disposed in the vicinity of the rotation roller to indicate the rotation direction of the rotation roller. A fingerprint reader which is a rotation detection sensor that outputs a signal and a rotation amount signal indicating the rotation amount is obtained. In this fingerprint reader, the rotation detection sensor outputs a rotation amount signal at a low level in a standby state where the rotation roller is not rotating, and includes a rotation amount signal at a high level in a reading state where the rotation roller is rotated. Is preferably output.

  On the other hand, according to the present invention, in any one of the above fingerprint readers, the rotation detection means is arranged in the vicinity of the rotation roller and images the rotation roller in a state where the fingerprint pattern can be read by the fingerprint reading sensor. In addition to including an imaging unit that obtains imaging data, the image processing calculation control unit analyzes the imaging data to obtain rotation direction data indicating the rotation direction of the rotating roller and rotation amount data indicating the rotation amount. A fingerprint reader is obtained.

  On the other hand, according to the present invention, in any one of the above fingerprint readers, the fingerprint reader sensor obtains a partial image of the fingerprint pattern with a sensitive element composed of capacitance elements that enable sensing of the capacitance matrix pattern. A sweep-type capacitance sensor that acquires fingerprint image data with the image processing operation control unit reconstructs an image of fingerprint image data as image processing, and the storage device stores at least the image of the fingerprint image data. A fingerprint reading device including data necessary for reconstruction or data storing the rotation direction data and rotation amount data is obtained.

  In the case of the fingerprint reading apparatus of the present invention, the fingerprint reading sensor is driven so that the fingerprint reading sensor can read the fingerprint pattern after the rotation of the rotating roller detected by the rotation detecting means is confirmed by the image processing calculation control unit. The fingerprint image data is acquired by control, and the amount of overlap during the synthesis of the fingerprint image data is controlled based on the period corresponding to the rotation amount of the rotating roller as image processing, so the power consumption in the standby state is reduced. As much as possible, the convenience is improved, and the fingerprint image can be efficiently reconstructed, and the fingerprint detection can be performed stably. In addition, the image processing arithmetic control unit has a function of performing drive control and overlap amount control according to an image processing program read from the storage device, and counts and holds the period based on the rotation amount of the rotating roller. Based on the period read from the rotation period counter, the amount of slippage when moving with the fingertip is calculated and estimated, and the amount of overlap is controlled based on the amount of slippage. Since the number of times of checking for duplication can be reduced and efficiency is improved, image processing can be performed quickly and with high accuracy, which is not possible conventionally. Further, the rotation detection sensor as the rotation detection means for detecting the rotation direction and the rotation amount of the rotation roller outputs a rotation amount signal at a low level in a standby state where the rotation operation of the rotation roller is not performed, and the reading operation in which the rotation operation of the rotation roller is performed. In the state, the rotation amount signal is output so as to include the High level, so that the rotation detection sensor side also saves power. Therefore, the power saving of the entire apparatus is further strengthened. Further, since the sweep type capacitance sensor is used as the fingerprint reading sensor, there is an advantage that it is small and simple.

  The fingerprint reading apparatus of the present invention is disposed in the vicinity of a rotating roller used for a rotating operation and the rotating roller, and is subjected to a moving contact by a fingertip of a person who is a subject along with the rotating operation of the rotating roller. Sometimes a fingerprint reading unit including a fingerprint reading sensor that obtains fingerprint image data by reading a fingerprint pattern on the fingertip, and the fingerprint image data of the fingerprint image data according to the result of calculating the amount of finger movement based on the fingerprint image data In a basic configuration including an image processing calculation unit that performs image processing for combining and reconstructing a part, and a storage device that stores at least data necessary for image processing on fingerprint image data, Rotation detection means for detecting the rotation direction and rotation amount is provided, and the image processing calculation unit is operated by the fingerprint reading sensor after the rotation of the rotation roller is confirmed by the rotation detection means. Image processing calculation control for controlling the amount of duplication when synthesizing fingerprint image data based on a period corresponding to the amount of rotation of the rotating roller as image processing, while driving and controlling the fingerprint reading sensor so that the pattern pattern can be read. Part.

  In addition, in this fingerprint reading device, a program for image processing is stored in a storage device so that the image processing arithmetic control unit performs drive control and overlap amount control in accordance with the program read from the storage device, and rotation. A rotation cycle counting unit for counting and holding the cycle based on the rotation amount of the roller is provided, and the magnitude of slipping during movement by the fingertip is determined based on the cycle read from the rotation cycle counting unit by the image processing calculation control unit. It is preferable to calculate and estimate, and to control the amount of overlap based on the magnitude of the slip.

  Further, in this fingerprint reader, as a fingerprint reader sensor, a sweep type static image sensor that acquires fingerprint image data by obtaining a partial image of the fingerprint pattern with a sensitive element composed of a capacitance element that enables sensing of the capacitance matrix pattern. Using a capacitance sensor, the image processing calculation control unit reconstructs the image of the fingerprint image data, and the storage device includes at least data necessary for reconstructing the image of the fingerprint image data. preferable.

  In the case of a fingerprint reading device having such a configuration, a rotating roller corresponding to the amount of finger movement by the rotation detecting means when the rotating roller arranged in front of or behind the fingerprint reading sensor (sweep type capacitive sensor) is rotated. The rotation direction and amount of rotation are detected, and based on the detection result, the image processing calculation control unit confirms the rotation of the rotating roller and then reads the fingerprint pattern by the fingerprint reading sensor, thereby driving and controlling the fingerprint reading sensor. Fingerprint image data is acquired, and a fingerprint pattern is detected by a fingerprint reading sensor after the rotation operation of the rotation roller in order to control the overlap amount when synthesizing the fingerprint image data based on the period corresponding to the rotation amount of the rotation roller as image processing. The fingerprint image data obtained by reading the fingerprint pattern with the fingerprint reader sensor. It is easy to re-build of (the image).

  FIG. 1 is a block diagram illustrating a basic configuration of a fingerprint reading apparatus 1 according to a first embodiment of the present invention.

  The fingerprint reading device 1 is disposed in the vicinity of a rotating roller 29 that is used for a rotating operation and the rotating roller 29, and receives a moving contact by a fingertip of a person who is a subject in accordance with the rotating operation of the rotating roller 29. The swept capacitive sensor 22 as a fingerprint reading sensor that obtains fingerprint image data by reading the fingerprint pattern on the fingertip and the rotating roller 29 is arranged in the vicinity of the rotating roller 29 to determine the rotation direction and amount of rotation of the rotating roller 29. A fingerprint reading unit 20 comprising a rotation detection sensor 28 serving as a rotation detection means for detecting, and a part of the fingerprint image data is synthesized and reconstructed according to the result of calculating the movement amount of the finger based on the fingerprint image data. In addition to having a basic function as an image processing arithmetic unit that performs image processing for the purpose of the image processing, the rotation detection sensor 28 confirms the rotation of the rotation roller 29 and then performs a swipe Fingerprint image data is controlled based on a period corresponding to the rotation amount of the rotating roller 29 as image processing, and the sweep type capacitance sensor 22 is driven and controlled so that the fingerprint pattern can be read by the group capacitance sensor 22. CPU 10 as an image processing calculation control unit for controlling the amount of overlap when combining images, a rotation cycle counting unit (RTC) 15 for counting and holding cycles, and image processing for fingerprint image data (specifically, the image) Data transmission / reception between the external device 17 connected to the external device 17 and a storage device comprising a RAM 14 in which data necessary for the storage is stored, and a ROM 12 in which a program for performing operation processing in the CPU 10 is stored. CPU 10 connected to each part other than rotating roller 29 is provided with I / F controller 16 for performing When performing image processing according to the program read from 2, the amount of slippage during movement by the fingertip is calculated and estimated based on the cycle read from the rotation cycle counting unit 15, and the amount of overlap is calculated based on the size of the slip It has a function to control.

  That is, in the fingerprint reader 1, the ROM 12, which is a non-volatile storage device dedicated to reading data, mainly controls the drive of the sweep type capacitive sensor 22 by the CPU 10 and reads the fingerprint pattern from the sweep type capacitive sensor 22. A program for performing a series of operation processing including image processing on the fingerprint image data obtained in (1) is stored. The RAM 14, which is a volatile storage device capable of reading and writing data, mainly stores data associated with image processing and other data in a rewritable manner. The rotation cycle counting unit 15 counts a cycle (time) corresponding to the rotation amount of the rotation roller 29 obtained by the rotation detection sensor 28 and holds the value.

  In operation, the CPU 10 first reads out a program for operation processing from the ROM 12 to issue an input command to the fingerprint reading unit 20, and the fingerprint reading unit 20 performs a rotation roller 29 by the rotation detection sensor 28 based on the input command. The CPU 10 is notified of the data indicating the presence / absence of the rotation operation at, and if this data is valid data indicating the rotation of the rotation roller 29, the CPU 10 is notified of this. Therefore, after receiving the rotation direction signal and the rotation amount signal from the rotation detection sensor 28 as the valid data notification, the CPU 10 drives and controls the sweep type capacitance sensor 22 in the fingerprint reading unit 20, and the sweep type capacitance sensor. The fingerprint pattern obtained from 22 is read to obtain fingerprint image data, image processing including control of the overlapping amount when the fingerprint image data is synthesized is executed, and the fingerprint image data resulting from the image processing is written into the RAM 14. Further, the CPU 10 issues a data transmission / reception command to the I / F controller 16 as necessary, and reads or writes data to the I / F controller 16 following the command. The I / F controller 16 transmits and receives data to and from the external device 17 based on a command issued from the CPU 10.

  FIG. 2 is an enlarged side view showing a detailed configuration of the fingerprint reading unit 20 which is a main part of the fingerprint reading device 1.

  Here, the arrangement of each part constituting the fingerprint reading unit 20 is illustrated. That is, the casing of the fingerprint reading device 1 is provided with a slit so that a part of the outer peripheral surface of the rotation roller 29 is exposed along the direction of the rotation axis of the rotation roller 29. It is mounted in the housing so that a part of the outer peripheral surface is exposed and used for a rotation operation. The sweep-type electrostatic capacitance sensor 22 is provided at a distance in the vicinity of the rotation roller 29 so that the finger naturally contacts when the rotation roller 29 is rotated, and outputs fingerprint pattern data to the CPU 10. The rotation detection sensor 28 provided in the vicinity of the rotation roller 29 in the housing is composed of an encoder, a potentiometer, and the like. The rotation detection sensor 28 detects the rotation amount of the rotation roller 29 and rotates at a period corresponding to the detected rotation amount. A function of outputting a signal, and a function of outputting a rotation direction signal indicating the rotation direction of the rotary roller 29.

  The sweep type capacitance sensor 22 is driven and controlled by the CPU 10 after the rotation operation of the rotation roller 29 is detected by the rotation detection sensor 28, and the timing of the rotation direction signal and the rotation amount signal output from the rotation detection sensor 28 is detected. The fingerprint pattern data (fingerprint image data) is fetched in accordance with.

  Incidentally, the rotation cycle counting unit 15 described above receives the rotation amount signal output from the rotation detection sensor 28, counts the cycle (time) of the rotation amount signal, and holds the data for one rotation amount signal cycle. The data of one period of the rotation amount signal held in the rotation period counter 15 can be read and written from the CPU 10.

  When image processing is performed on fingerprint image data obtained by fetching fingerprint pattern data by the sweep-type capacitive sensor 22, the finger moving speed according to the finger moving direction is constant as shown in FIG. 2, for example. When there is no slip, the fingerprint image data overlaps with a certain width. However, if the finger movement speed increases, the slip increases, so the actual calculation is based on the rotation direction and amount of rotation from the rotation detection sensor 28. The duplication of fingerprint image data is less than the amount of duplication. The fingerprint reading device 1 of the present invention also has an equivalent function as compared with the method of imaging every time the finger moves a certain distance as in the case of Patent Document 1, but the fingerprint reading device 1 of the present invention has an image. Since the CPU 10 looks at the moving speed (cycle) during processing, the magnitude of the slip can be predicted to some extent. That is, the size of the slip can be predicted from the moving speed of the finger, and the efficiency of reconstructing the fingerprint image can be improved (details will be described later).

  FIG. 3 is a timing chart illustrating the time transition of the rotation direction signal and the rotation amount signal according to the rotation operation of the rotation roller 29 output from the rotation detection sensor 28 provided in the fingerprint reading device 1.

  Here, as the output signal of the rotation detection sensor 28, when the rotation roller 29 is not rotating, the rotation amount signal is output at the Low level, and the rotation direction signal is not changed from the previous value (in the case of the illustration, the Low level). ) And the rotation roller 29 is rotated, the rotation amount signal is periodically changed from the low level to the high level and from the high level to the low level with a cycle corresponding to the rotation amount of the rotation roller 29. It is shown that the rotation direction signal in a state corresponding to the rotation direction is output. The rotation direction signal output from the rotation detection sensor 28 outputs, for example, a high level when the rotating roller 29 rotates counterclockwise as shown in FIG. 2 and a low level when the rotation roller 29 rotates clockwise. The case of outputting can be illustrated.

  In the form shown in FIG. 2, when a fingerprint is read by the fingerprint reader 1, the tip of the subject's fingertip is directed to the right side with respect to the sweep type capacitive sensor 22, and then the fingertip is moved from the right side to the left side. In this way, the case where the moving direction of the finger is leftward is shown. At this time, the moving fingertip rotates the rotating roller 29 counterclockwise along with the movement, and when the rotating roller 29 rotates counterclockwise, the rotation detection sensor 28 rotates with a period corresponding to the rotation amount of the rotating roller 29. The quantity signal is periodically changed from the Low level to the High level and from the High level to the Low level, and the rotation direction signal is output at the High level.

  FIG. 4 is a flowchart showing an operation process of fingerprint reading by the fingerprint reading apparatus 1.

  In the fingerprint reading operation process in the fingerprint reading device 1, first, the CPU 10 monitors the rotation amount signal from the rotation detection sensor 28, and the rotation is detected by determining whether or not the signal level has changed from Low to High. It is determined whether or not (step S1).

  As a result, if rotation is not detected, the process returns to and waits before determining whether rotation is detected (step S1), but if it is determined that the rotating roller 29 is rotating, the CPU 10 detects rotation. Every time the rotation amount signal of the sensor 28 becomes high level, the image data obtained by reading the fingerprint pattern data from the sweep type capacitance sensor 22 and the cycle counted by the rotation cycle counter 15 based on the rotation amount signal. Are read out and stored in the RAM 14 to read the image data (step S2).

  Next, the CPU 10 extracts two fingerprint image data stored in the RAM 14 in time series order, and performs a process of estimating an overlapping portion of the image (step S3). Here, in the case of an ideal state where there is no slip between the moved finger and the rotating roller 29, the two fingerprint image data are in the direction in which the finger is moved regardless of the moving speed of the finger. The rotation amount signal of the rotation detection sensor 28 becomes equal to the rotation amount for outputting the High level, and the images overlap at regular intervals. Therefore, the CPU 10 searches for an overlapping portion of the two fingerprint image data based on the rotation amount at which the rotation amount signal of the rotation detection sensor 28 outputs a high level in accordance with the program, and combines the images according to the searched result ( After step S4) is performed and the image is reconstructed, it is determined whether the reading is finished (step S5). As a result, if the reading is not completed, the process returns to before the image data reading process (step S2), and the above-described process for reconstructing the image is repeated for all the fingerprint image data on the time series. After the fingerprint image data indicating one fingerprint pattern is obtained, the reading is completed in the same manner as the reading is completed.

  By the way, in the image processing by the CPU 10, two fingerprint image data stored in the RAM 14 are taken out in time series order, and the rotation amount signal obtained from the rotation period counting unit 15 simultaneously with the latter data in the time series of the two fingerprint image data. Based on the periodic data, the magnitude of slippage during movement by the fingertip is calculated and estimated, and the amount of overlap is controlled based on the magnitude of the slippage. Since this periodic data indicates time, it is estimated that the shorter the value, the faster the finger is moved.

  In general, the faster the finger is moved, the greater the slip between the moved finger and the rotating roller 29. Therefore, it is estimated that the amount of overlap between the two extracted fingerprint image data decreases. Therefore, when reconstructing the image, by correcting the overlapping area (duplication amount) of two fingerprint image data in time series based on the size of the period data of the rotation amount signal acquired from the rotation period counting unit 15, It is possible to obtain an overlapping area (duplication amount) with a smaller number of calculations. This means that the time required for the CPU 10 to reconstruct the fingerprint image data indicating the fingerprint pattern for one finger is shortened.

  Incidentally, in the CPU 10, when the rotation amount signal of the rotation detection sensor 28 is at the Low level for a certain period, it is determined that the rotating roller 29 is not rotating, and the rotation amount signal held in the rotation cycle counter 15 is included in the cycle data of the rotation amount signal. 0 is written and fingerprint data is not read by the sweep type capacitance sensor 22 without driving and controlling the sweep type capacitance sensor 22.

  FIG. 5 is a schematic diagram of fingerprint image data shown to explain image reconstruction processing (image processing) in consideration of finger slipping by the CPU 10.

  As described above, the rotation detection sensor 28 outputs a rotation amount signal indicating a period corresponding to the rotation amount (a constant rotation amount = a time when a finger movement distance occurs). If the period of the rotation amount is long, the movement speed of the finger is slow and the slip is small, but conversely, if the period is short, the movement speed of the finger is high and the slip is large.

  Referring to FIG. 5, since the moving speed of the finger is slow between the image areas A and B, the moving distance (the rotating amount of the rotation detection sensor 28) obtained from the rotation amount period and the actual moving amount of the finger. The difference is reduced by the small slip.

  However, since the moving speed is faster between the image areas CD than the image areas AB, the rotation amount period is shorter than that between the image areas AB. Furthermore, the difference between the movement distance (rotation amount of the rotation detection sensor 28) obtained from the period of the rotation amount and the actual movement amount of the finger becomes large due to the large slip, and this causes the overlapping region of the image. Becomes smaller.

  Specifically, the period from the rotation detection sensor 28 in the movement of the finger without slipping is T0, and the rotation speed from the rotation detection sensor 28 at a speed at which the finger movement speed increases and the fingerprint cannot be reconstructed. The cycle is T5, and there are 4 lines, 3 lines, 2 lines, overlapping lines from T0 where there are no slips, and T5 where there are no overlapping lines because the finger speed is high and the slip is large. Assuming that the period corresponding to the speed of each finger forming one line is T1, T2, T3, and T4, if the output from the rotation detection sensor 28 is equal to or greater than T0, there is no slip, so there is an overlap of five lines. Similarly, it is considered that there is an overlap of about 5 lines between T0 and T1, similarly, 4 lines between T1 and T2, 3 lines between T2 and T3, 2 lines between T3 and T4, Is between 4 and T5 1 line is considered that there is no overlap if T5 below.

  As described above, the approximate overlap amount can be determined by the period of the rotation amount signal output from the rotation detection sensor 28. Therefore, when the start position for examining the overlap region when the image is reconstructed is T1 or more, about 5 lines. , Around four lines in the case of T1 to T2, around three lines in the case of T2 to T3, around two lines in the case of T3 to T4, and around one line in the case of T4 to T5, respectively. It will be enough to examine as. That is, here, it is shown that the approximate number of times of examining the overlapping area of the image can be known, so that the number of times of examining the overlapping area of the image can be reduced when the image is reconstructed.

  FIG. 6 is a schematic view exemplifying local fingerprint image data stored in the RAM 14 that is used for the above-described image reconstruction processing (image processing).

  The local fingerprint image data stored and stored in the RAM 14 is a fingerprint pattern read at a time at the input unit of the fingerprint reading sensor (sweep capacitive sensor 22) for the fingerprint ridge M indicated by a solid line. The data are stored in the storage areas so as to correspond to the local areas E1 and E2, respectively. The fact that the positions of the local areas E1 and E2 of the fingerprint pattern are shifted indicates that the relative positions of the finger and the input portion are shifted for each input.

Using the density distribution of each dot in the fingerprint image data, the calculation target image is the fingerprint image data of the local region E1, the reference image is the fingerprint image data of the local region E2, and the coordinates (X, Y) are used in the local region E1. When the density data of the designated dot is P ₁ (X, Y) and the density data of the dot designated by the coordinates (X, Y) in the local area E2 is P ₂ (X, Y), the relative data The image difference amount D between the two local fingerprint image data representing the calculation of the positional relationship is defined as expressed by the following equation (1).

  In other words, the image difference amount D shown in Equation 1 is obtained by superposing the local area E1 by shifting (x, y) with respect to the local area E2 and adding the differences of the corresponding dots in the overlapped area. It is.

  In FIG. 6, there is a common area Ex that is included in common with the local areas E1 and E2, and the relative position of the local area E1 to the local area E2 is (x0, y0). The value of D (x0, y0) is ideally 0.

  In this way, D (x, y) is obtained for various (x, y), and by searching for a set of (x, y) whose value is 0, the relative position of the local area E1 with respect to the local area E2 is obtained. Can be sought. However, since a certain amount of noise is included in the actual local fingerprint image data, the value of D (x0, y0) does not necessarily become 0, but a pair with the smallest absolute value of D (x, y) is searched. Then, (x0, y0) can be obtained.

  In the fingerprint reading apparatus 1 according to the first embodiment described above, the machine rotation detection sensor 28 serving as a rotation detecting unit is included in the fingerprint reading unit 20 and disposed in the vicinity of the rotating roller 29, so The rotation direction signal indicating the rotation direction and the rotation amount signal indicating the rotation amount have been described as being output. However, the rotation detection unit is arranged in the vicinity of the rotation roller 29 in addition to this, for example, the sweep type capacitance sensor 22. In addition to including an imaging unit such as a CCD for imaging the rotating roller 29 and obtaining imaging data while the fingerprint pattern can be read by the CPU 10, the imaging data is subjected to image analysis by the CPU 10 serving as an image processing calculation control unit. To obtain rotation direction data indicating the rotation direction of the rotation roller 29 and rotation amount data indicating the rotation amount (such as detection of rotation angular velocity). Since equivalent function in the obtained) as the obtained may be replaced by such a configuration. However, in this case, when the CPU 10 reconstructs fingerprint image data (its image) as image processing, the rotation direction other than storing the data necessary for reconstructing the fingerprint image data (its image) in the RAM 14. What is necessary is just to comprise so that data and rotation amount data may be memorize | stored.

1 is a block diagram showing a basic configuration of a fingerprint reading apparatus according to Embodiment 1 of the present invention. It is the side view which expanded and showed the detailed structure of the fingerprint reading part which is the principal part of the fingerprint reading apparatus shown in FIG. 3 is a timing chart illustrating time transitions of a rotation direction signal and a rotation amount signal according to a rotation operation of a rotation roller output from a rotation detection sensor provided in the fingerprint reading device illustrated in FIG. 1. 3 is a flowchart showing a fingerprint reading operation process by the fingerprint reading apparatus shown in FIG. 1. FIG. 3 is a schematic diagram of fingerprint image data shown to explain image reconstruction processing (image processing) in consideration of finger slipping by a CPU provided in the fingerprint reading device shown in FIG. 1. FIG. 6 is a schematic view illustrating local fingerprint image data stored in a RAM provided for processing (image processing) for reconstructing the image described in FIG. 5.

Explanation of symbols

1 Fingerprint reader 10 CPU
12 ROM
14 RAM
15 Rotation cycle counter (RTC)
16 I / F controller 17 External device 20 Fingerprint reader 22 Sweep type capacitance sensor 28 Rotation detection sensor 29 Rotation roller

Claims (6)

A rotating roller that is used for a rotating operation, and a fingerprint that is disposed in the vicinity of the rotating roller and receives a moving contact by a fingertip of a person who is the subject in accordance with the rotating operation of the rotating roller. A fingerprint reading unit including a fingerprint reading sensor that obtains fingerprint image data by reading a pattern;
An image processing calculation unit that performs image processing for synthesizing and reconstructing a part of the fingerprint image data according to a result of calculating the movement amount of the finger based on the fingerprint image data;
In a fingerprint reading device comprising at least a storage device for storing data necessary for the image processing on the fingerprint image data,
Rotation detection means for detecting the rotation direction and rotation amount of the rotating roller ;
A rotation cycle counting unit for counting and holding the cycle based on the rotation amount of the rotation roller ;
The image processing calculation unit drives and controls the fingerprint reading sensor so that the fingerprint pattern can be read by the fingerprint reading sensor after the rotation detection unit confirms the rotation of the rotating roller, and the image image processing operation control unit der for controlling the amount of overlap in the synthesis of the fingerprint image data based on the cycle read from the rotational period counter as a process is,
The image processing calculation control unit extracts two pieces of the fingerprint image data in time series order, and determines the magnitude of slipping during movement by the fingertip based on the latter time series data of the two fingerprint image data and the period. A fingerprint reading apparatus characterized by controlling a starting position for examining an overlapping area of two fingerprint image data based on a magnitude of slippage calculated and estimated .   The fingerprint reading apparatus according to claim 1, wherein the storage device includes a storage unit storing a program for the image processing, and the image processing calculation control unit performs the drive control and the control according to the program read from the storage device. A fingerprint reader which controls the amount of overlap. 3. The fingerprint reading apparatus according to claim 1, wherein the rotation detecting means is included in the fingerprint reading unit and is arranged in the vicinity of the rotating roller to indicate the rotating direction of the rotating roller; And a rotation detection sensor that outputs the rotation amount signal indicating the rotation amount. 4. The fingerprint reader according to claim 3 , wherein the rotation detection sensor outputs the rotation amount signal at a low level in a standby state in which the rotating roller is not rotating, and in a reading state in which the rotating roller is rotating. A fingerprint reader which outputs the rotation amount signal so as to include a high level. 3. The fingerprint reader according to claim 1, wherein the rotation detection unit is arranged in the vicinity of the rotation roller and images the rotation roller in a state where the fingerprint pattern can be read by the fingerprint reading sensor. Including an imaging unit for obtaining data, and performing image analysis on the imaging data by the image processing calculation control unit to obtain rotation direction data indicating the rotation direction of the rotation roller and rotation amount data indicating the rotation amount A fingerprint reader characterized by the above. In the fingerprint reading apparatus according to any one of claims 1 to 5, wherein the fingerprint reading sensor is a partial image of the fingerprint pattern in the sensitive element consists of the capacitance elements to enable sensing of the matrix pattern of capacitance It is a sweep-type capacitive sensor that acquires the fingerprint image data by obtaining the image processing calculation control unit to reconstruct the image of the fingerprint image data as the image processing, and the storage device A fingerprint reader including at least data necessary for reconstructing an image of the fingerprint image data, or data storing the rotation direction data and the rotation amount data.

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