Authentication system having a flexible imaging pressure sensor
First Claim
1. An access control system including a fingerprint authentication subsystem comprising:
- a) an imaging pressure sensor for providing an image of a textured surface, the sensor comprising;
i) a flexible membrane conformable to the textured surface;
ii) a flexible sensor substrate, wherein said sensor substrate has a flexural rigidity DS and said membrane has a flexural rigidity DM, and wherein DM <
DS <
106 DM;
iii) at least two pressure sensor elements, wherein each pressure sensor element is responsive to a separation between a part of the membrane and a corresponding part of the sensor substrate; and
iv) a spacer disposed between and connected to the membrane and the sensor substrate;
wherein each of the separations has a corresponding non-zero nominal value determined in part by the spacer; and
b) electronic circuitry connected to the pressure sensor.
4 Assignments
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Accused Products
Abstract
A sensor for a textured surface (e.g., a fingerprint) is provided. The sensor includes a flexible substrate and a flexible membrane supported above the substrate by one or more spacers. The sensor also includes multiple pressure sensor elements responsive to a separation between parts of the membrane and corresponding parts of the substrate. The membrane is conformable to the textured surface being sensed, so the variation in separation between substrate and membrane is representative of the textured surface being sensed. Such pressure sensors can be included in fingerprint authentication subsystems including associated integrated electronic circuitry (e.g., encryption, image processing, fingerprint matching, communication and/or location determination circuitry). Such subsystems can be included in various access control systems (e.g., smart cards and mobile electronics). Unpackaged IC chips can be included on the flexible substrate or can be disposed on a separate electronics substrate attached to the sensor.
124 Citations
25 Claims
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1. An access control system including a fingerprint authentication subsystem comprising:
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a) an imaging pressure sensor for providing an image of a textured surface, the sensor comprising; i) a flexible membrane conformable to the textured surface; ii) a flexible sensor substrate, wherein said sensor substrate has a flexural rigidity DS and said membrane has a flexural rigidity DM, and wherein DM <
DS <
106 DM;iii) at least two pressure sensor elements, wherein each pressure sensor element is responsive to a separation between a part of the membrane and a corresponding part of the sensor substrate; and iv) a spacer disposed between and connected to the membrane and the sensor substrate; wherein each of the separations has a corresponding non-zero nominal value determined in part by the spacer; and b) electronic circuitry connected to the pressure sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification