26-04-2012, 04:08 PM
A SINGLE-CHIP FINGER PRINT SENSOR AND IDENTIFIER
[attachment=20901]
INTRODUCTION:
Portable and mobile types of equipment, like IC cards, notebook computers, and cellular phones, are becoming increasingly popular. Consequently, user authentication to prevent unauthorized use of such equipment has become an important issue. For consumer products, the authentication process should be simple and reliable. Methods of user authentication include the use of passwords, personal identification numbers (PIN’s), and verification using the iris in the human eye. One of the simplest and most reliable authentication method is the fingerprint. For use in portable and mobile equipment, the fingerprint identification unit should be compact and inexpensive and must guarantee security of the user’s data and privacy.
FINGERPRINT SENSOR/IDENTIFIER CHIP:
A. Requirements for Fingerprint Chip Architecture: Recently, some architecture for the integration of the sensor and processing unit in a single chip has been reported. Fig. 1 shows the conventional photo image sensing chip architecture. In the architecture for a sensor embedded chip, the sensor and processing unit are integrated on a single chip by placing them side by side, as shown in Fig. 1(a). The photo sensor does not require large area, but a rather large number of pixels are needed for capturing an array.
IDENTIFYING PIXEL:
For the fingerprint identification, the array of identifying pixels employs pixel parallel image processing. For such processing, each processing element in the identifying pixels has to perform image processing on a 1-pixel datum of a fingerprint image in parallel. Hence, an identifying pixel must:
SENSOR STRUCTURE:
Fig. 6 is a cross section of an identifying pixel. The sensor plate is situated above some logic circuits, which are composed of the sensing, memory, and processing circuits.When a finger comes in contact with the chip, the capacitance between the plate and the finger is either for a ridge or for a valley. These capacitances are detected and binarized by the sensing circuits directly under the plate .Each sensor plate is surrounded with a lattice-like wall. This wall is also exposed on the chip surface and connected to ground.
CONCLUSION:
A chip architecture that enables a fingerprint sensor and identifier to be integrated on a single chip has been presented. The key feature is a pixel architecture that incorporates a sensing element and a processing element by stacking them without a large increase of chip size. This enables a high-sensitivity
sensing element to be fabricated above the processing element while maintaining high image density. Each pixel is surrounded by a ground wall to shield it to suppress the noise.
[attachment=20901]
INTRODUCTION:
Portable and mobile types of equipment, like IC cards, notebook computers, and cellular phones, are becoming increasingly popular. Consequently, user authentication to prevent unauthorized use of such equipment has become an important issue. For consumer products, the authentication process should be simple and reliable. Methods of user authentication include the use of passwords, personal identification numbers (PIN’s), and verification using the iris in the human eye. One of the simplest and most reliable authentication method is the fingerprint. For use in portable and mobile equipment, the fingerprint identification unit should be compact and inexpensive and must guarantee security of the user’s data and privacy.
FINGERPRINT SENSOR/IDENTIFIER CHIP:
A. Requirements for Fingerprint Chip Architecture: Recently, some architecture for the integration of the sensor and processing unit in a single chip has been reported. Fig. 1 shows the conventional photo image sensing chip architecture. In the architecture for a sensor embedded chip, the sensor and processing unit are integrated on a single chip by placing them side by side, as shown in Fig. 1(a). The photo sensor does not require large area, but a rather large number of pixels are needed for capturing an array.
IDENTIFYING PIXEL:
For the fingerprint identification, the array of identifying pixels employs pixel parallel image processing. For such processing, each processing element in the identifying pixels has to perform image processing on a 1-pixel datum of a fingerprint image in parallel. Hence, an identifying pixel must:
SENSOR STRUCTURE:
Fig. 6 is a cross section of an identifying pixel. The sensor plate is situated above some logic circuits, which are composed of the sensing, memory, and processing circuits.When a finger comes in contact with the chip, the capacitance between the plate and the finger is either for a ridge or for a valley. These capacitances are detected and binarized by the sensing circuits directly under the plate .Each sensor plate is surrounded with a lattice-like wall. This wall is also exposed on the chip surface and connected to ground.
CONCLUSION:
A chip architecture that enables a fingerprint sensor and identifier to be integrated on a single chip has been presented. The key feature is a pixel architecture that incorporates a sensing element and a processing element by stacking them without a large increase of chip size. This enables a high-sensitivity
sensing element to be fabricated above the processing element while maintaining high image density. Each pixel is surrounded by a ground wall to shield it to suppress the noise.