JP3558975B2 - Fingerprint collation device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fingerprint matching device for matching fingerprint data registered in advance with fingerprint data detected by a semiconductor capacitive sensor.
[0002]
[Prior art]
A semiconductor capacitive sensor used in this type of fingerprint collating device detects unevenness of a human fingerprint as a capacitance difference and generates a grayscale image.
When authenticating a user using a fingerprint, the fingerprint matching device registers the fingerprint data of the user in advance. Then, when a user's finger is imprinted on the semiconductor capacitive sensor, the unevenness of the fingerprint of the user is detected as a fingerprint image based on the capacitance difference of the capacitive sensor as described above, and the detected fingerprint image is detected. , And compares the generated fingerprint data with the registered fingerprint data. If the two match, the user is identified as the user.
[0003]
[Problems to be solved by the invention]
Generally, human fingertips have individual differences such as dry skin and oily skin. In a conventional fingerprint collation device, since a semiconductor capacitive sensor detects a fingerprint image of a human fingertip having such individual differences under the same conditions irrespective of individual differences, an accurate fingerprint image necessary for collation can be obtained. There was a problem that it could not be obtained.
Accordingly, an object of the present invention is to accurately detect a fingerprint image of a human fingertip having individual differences such as dry skin or oily skin.
[0004]
[Means for Solving the Problems]
In order to solve such a problem, the present invention provides a semiconductor having a plurality of sensors arranged in a grid and detecting a fingerprint of a user, and an A / D converter for converting a detection output of the sensor into a digital value. a capacitive sensor chip made of, storing the fingerprint image data of a user, and a user specific parameters for the set to the a / D converter changes the luminance and resolution of the fingerprint image as the personal information of the user with a fingerprint verification unit for collating the storage unit stores the waiting time fingerprint image detection of a capacitive sensor chip, and a fingerprint image data storage unit and the detected fingerprint image data by the capacitive sensor chip, a / a setting unit for setting the parameters of the storage unit relative to D conversion unit, after setting the parameters to the a / D converter by the setting unit, the contact of the finger to the sensor is detected, the waiting storage unit Provided a control unit for detecting the start the capacitive sensor chips after time fingerprint image data, the fingerprint comparing unit includes a fingerprint image data detected by the capacitive sensor chip after activation of the capacitive sensor chip of the control unit The fingerprint authentication is performed by collating the fingerprint image data in the storage unit .
Also, the storage unit stores personal information is provided on the IC card, the IC card reader for reading data of the IC card, capacitive sensor chip, the fingerprint comparing unit, which was provided with a setting unit, the control unit and the detection unit is there.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of the fingerprint matching device according to the present invention. As shown in FIG. 1, the fingerprint collation apparatus includes an IC card reader 1 and an IC card 2. The IC card reader 1 inputs a semiconductor capacitive sensor chip (hereinafter, sensor chip) 11 for detecting a fingerprint of the finger 3 imprinted by a user, and fingerprint image data detected by the sensor chip 11, and performs predetermined processing. , A memory 13 for storing fingerprint image data input by the control unit 12, a display unit 14 for performing various displays, and an interface 15 for the IC card 2.
[0006]
The sensor chip 11 includes a sensor unit 11A and an A / D conversion unit 11B that digitizes a fingerprint image detected by the sensor unit 11 and outputs the digitized fingerprint image to the control unit 12 as fingerprint image data. Further, the control unit 12 includes a timer 12A.
Further, the IC card 2 has an interface 21 with the IC card reader 1 and a memory 22 for registering fingerprint image data of the user.
[0007]
When the user's finger 3 is impressed, the sensor section 11A of the sensor chip 11 constituting the IC card reader 1 generates a capacitance difference corresponding to the unevenness of the skin surface of the contacted finger 3 (that is, a fingerprint). The voltage signal is output as a voltage signal. The voltage signal output from the sensor unit 11A is converted into a digital signal by the A / D conversion unit 11B as described above, and is output to the control unit 12 as fingerprint image data.

[0008]
2 and 3 are views showing the configuration of the sensor section 11A in the sensor chip 11 described above. The sensor section 11A is composed of a plurality of sensors 4 arranged in a grid as shown in FIG. 2, and the sensor 4 which is one unit sensor has a detecting element 41 which is a capacitive element as shown in FIG. The circuit includes a circuit, a signal amplifying circuit 43, and an output circuit. When the finger 3 comes into contact, a capacitance difference is generated in the detecting element 41 of each sensor 4 according to the unevenness of the surface of the skin of the contacted finger 3. And is output from the output circuit 44 to the A / D converter 11B.
[0009]
The A / D converter 11B constituting the sensor chip 11 converts an analog voltage level (analog value) output from the output circuit 44 of the sensor 4 into a digital value, and according to a set parameter value. The correspondence between the analog value and the digital value changes.
As parameters set in the A / D conversion unit 11B, parameter values A and B as shown in FIG. 4 are set.
[0010]
If the analog value input to the A / D converter 11B is lower than the set parameter value (A + B), it is assumed that the A / D converter 11B can obtain a black fingerprint image of gray level 0. If the analog value input to the A / D converter 11B is equal to or more than the set parameter value (A + (255 × B)), a pure white fingerprint image with a gradation of 255 can be obtained from the A / D converter 11B. I do. Further, if the analog value input to the A / D converter 11B is at a level equal to or more than the parameter value (A + n × B) and less than the parameter value (A + (n + 1) B), the gray scale n from the A / D converter 11B. Is obtained.
[0011]
Thus, when the parameter value A is set to a large value, the fingerprint image obtained from the A / D conversion unit 11B becomes black, and when the parameter value A is set to a small value, the fingerprint image obtained from the A / D conversion unit 11B becomes white. When the parameter value B is set to a large value, the resolution of the fingerprint image obtained from the A / D conversion unit 11B becomes coarse, and when the parameter value B is set to a small value, the resolution of the fingerprint image obtained from the A / D conversion unit 11B becomes fine. Become.
By changing the parameter value of the A / D converter 11B in this manner, the brightness and resolution of the fingerprint image obtained from the A / D converter 11B can be changed. Therefore, when a fingerprint image of a human fingertip having individual differences such as dry skin or oily skin is detected, by setting a parameter value corresponding to such individual differences in the A / D conversion unit 11B, A / D conversion is performed. An accurate fingerprint image that is not affected by the individual difference as described above can be output from the D conversion unit 11B.
[0012]
FIG. 5 is a flowchart showing the operation of the main part of the fingerprint collating apparatus, showing the operation of reading a fingerprint by the sensor chip 11.
The operation of the main part of the present invention will be described in detail according to this flowchart.
By the way, the fingerprint image data unique to the user is registered in the memory 22 of the IC card 2, and the parameter value A unique to the user set in the A / D conversion unit 11B in the sensor chip 11 described above. , B, and the waiting time until the A / D converter 11B starts the conversion operation is registered and stored as the user's personal information.
[0013]
When the IC card 2 is inserted into the IC card reader 1 by the user, the control unit 12 of the IC card reader 1 first reads the fingerprint image data, parameter values, and the waiting time of the user from the memory 22 of the IC card 2 in step S1. The time is read and stored in the memory 13. Next, the control unit 12 sets the parameter value in the A / D conversion unit 11B via the signal line a shown in FIG. 1 in step S2, and sets the waiting time in the timer 12A in step S3.
[0014]
Next, the control unit 12 determines whether or not the user's finger 3 has been stamped on the sensor unit 11A in the sensor chip 11 via the signal line b shown in FIG. If detected, the timer 12A is started in step S5. Then, it is determined in step S6 whether or not the timer 12A has timed out. When the timer 12A has timed out, the A / D converter 11B is activated via the signal line c shown in FIG. 1 in step S7.
[0015]
Thereafter, the control unit 11 sequentially reads the fingerprint image data detected by the sensor unit 11A and digitized by the A / D conversion unit 11B in step S8 and sequentially stores them in the memory 13, and the reading of all the fingerprint image data is completed. If the determination in step S9 is "Y", the fingerprint image data read from the sensor chip 11 and stored in the memory 13 is compared with the fingerprint image data read from the memory 22 of the IC card 2 and stored in the memory 13 in step S9. This is performed in S10.
[0016]
Then, the quality of the result of the collation processing is determined in step S11. When the fingerprint image data read from the sensor chip 11 and the fingerprint image data read from the IC card 2 match, and the determination in step S11 becomes "Y", In step S12, the personal identification result indicating "identification" is output and displayed on the display unit 14.
[0017]
As described above, when a fingerprint image of a human fingertip having individual differences such as dry skin or oily skin is detected, a parameter value corresponding to such individual differences is set in the A / D converter 11B. Accordingly, an accurate fingerprint image that is not affected by individual differences as described above can be output from the A / D conversion unit 11B.
Furthermore, when a fingerprint image of a human fingertip having individual differences is detected, the detection waiting time of the sensor chip 11 is set according to the individual differences as described above. It is possible to obtain a more accurate fingerprint image which is not affected by the fingerprint.
[0018]
【The invention's effect】
As described above, according to the present invention, a capacitive sensor chip made of a semiconductor for detecting a fingerprint, a storage unit for storing personal information including fingerprint image data of a user and parameters of the capacitive sensor chip, A fingerprint collating unit for collating fingerprint image data detected by the sensor chip with fingerprint data of the storage unit, and a setting unit for setting parameters of the storage unit for the capacitive sensor chip; After setting the parameters for the chip, this capacitive sensor chip is activated to detect fingerprint image data, so that a fingerprint image of a human fingertip having a difference for each individual, such as dry skin or oily skin, is detected. In such a case, since parameters corresponding to such individual differences are set in the capacitive sensor chip, the capacitive sensor chip is not affected by the individual differences as described above. , It is possible to output an accurate fingerprint image.
In addition, the storage unit stores the waiting time at the time of detecting a fingerprint image of the capacitive sensor chip as personal information, and includes a detecting unit that detects contact of a finger with the capacitive sensor chip. After the detection, the capacitive sensor chip is activated after the elapse of the waiting time in the storage unit to start detection of the fingerprint image.Therefore, when detecting a fingerprint image of a human fingertip having individual differences, as described above. Since the detection waiting time of the capacitive sensor chip is set according to the individual difference, it is possible to output a more accurate fingerprint image from the capacitive sensor chip without being affected by such individual differences.
In addition, a storage unit for storing personal information is provided on the IC card, and a capacitive sensor chip, a fingerprint collation unit, a setting unit, a control unit, and a detection unit are provided on the IC card reader for reading data of the IC card. In addition, each user can properly manage and store his / her personal information.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a fingerprint matching device according to the present invention.
FIG. 2 is a diagram showing a configuration of a fingerprint sensor unit in a semiconductor capacitive sensor chip of the fingerprint collation device.
FIG. 3 is a block diagram showing a configuration of one detection unit in the semiconductor capacitive sensor chip.
FIG. 4 is a diagram showing the status of parameters set in an A / D converter in the semiconductor capacitive sensor chip.
FIG. 5 is a flowchart illustrating an operation of a main part of the fingerprint matching device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... IC card reader, 2 ... IC card, 3 ... finger, 4 ... sensor, 11 ... semiconductor capacitive sensor, 11A ... sensor part, 11B ... A / D conversion part, 12 ... control part, 12A ... timer, 13, 22 memory, 14 display unit, 15, 21 interface, 41 detection element, 42 signal generation circuit, 43 signal amplification circuit, 44 output circuit.

Claims (2)

A capacitive sensor chip composed of a semiconductor having a plurality of sensors arranged in a grid and detecting a fingerprint of a user, and an A / D converter for converting a detection output of the sensor into a digital value ;
A fingerprint image data of a user, along with storing the user specific parameters for set in the A / D converter changes the luminance and resolution of the fingerprint image as personal information of a user, said capacitive sensor chip A storage unit for storing a waiting time when a fingerprint image is detected ,
A fingerprint matching unit that compares fingerprint image data detected by the capacitive sensor chip with fingerprint image data of the storage unit,
A setting unit that sets parameters of the storage unit for the A / D conversion unit ;
After the setting unit sets the parameters to the A / D conversion unit , when a touch of the finger to the sensor is detected, the capacitive sensor chip is activated after a lapse of a waiting time of the storage unit, and the fingerprint image data is set. and a control unit for detecting the fingerprint verification unit verifies the fingerprint image data of the capacitive sensor chip after start fingerprint image data detected by the capacitive sensor chip the storage portion of the controller Fingerprint authentication device for performing fingerprint authentication by performing fingerprint authentication. In claim 1,
The storage unit for storing the personal information is provided on an IC card, and an IC card reader for reading data of the IC card is provided, and the IC card reader has the capacitive sensor chip, the fingerprint matching unit, the setting unit, A fingerprint matching device comprising a control unit and a detection unit .

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