Fingerprint sensor
View Patent ↗The invention provides a fingerprint sensor including a sensing array. The sensing array includes a plurality of sensing units to form a plurality of sensing regions arranged in an array. Each of the plurality of sensing regions includes at least one column of sensing units. A first part of the plurality of sensing regions receives a power signal to perform fingerprint sensing. A second part of the plurality of sensing regions does not receive a power signal. Therefore, the fingerprint sensor of the invention can provide a fast and energy-saving large-area fingerprint sensing effect.
1. A fingerprint sensor, comprising:
a sensing array, comprising a plurality of sensing units to form a plurality of sensing regions arranged in an array, wherein each of the plurality of sensing regions comprises at least one column of sensing units; and
a plurality of switch circuits, respectively coupled between corresponding sensing regions and a power input terminal, and respectively receiving corresponding control signals,
wherein when a first part of the plurality of sensing regions receives a power signal, to perform fingerprint sensing, a second part of the plurality of sensing regions does not receive a power signal,
wherein a first part of the plurality of switch circuits respectively provides the power signal provided by the power input terminal to the first part of the plurality of sensing regions according to the corresponding control signals,
wherein each of the plurality of sensing units comprises:
a photodiode, comprising a first terminal connected to ground;
a first transistor, comprising a first terminal directly coupled to the power input terminal, a second terminal directly coupled to a second terminal of the photodiode and a control terminal that respectively receives a correspond reset signal;
a second transistor, comprising a control terminal directly coupled to the second terminal of the photodiode and a first terminal coupled to the power input terminal via a corresponding switch circuit of the plurality of switch circuits; and
a third transistor, comprising a first terminal directly coupled to a second terminal of the second transistor, a second terminal directly connected to a corresponding signal readout line and a control terminal that respectively receives a corresponding selection signal,
wherein when the power signal is provided to the first terminal of the second transistor and when the third transistor is turned on via the corresponding selection signal, a second terminal of the third transistor outputs a sensing signal to the corresponding signal readout line,
wherein an N th column of sensing units in each of the plurality of sensing regions are coupled to each other via a same row signal line that directly connects between the signal readout lines of the N th column of sensing units, wherein N is a positive integer greater than 1.
2. The fingerprint sensor according to claim 1 , wherein each of the plurality of switch circuits comprises at least one switch component, wherein the at least one switch component is coupled in a one-to-one manner between the at least one column of sensing units of the corresponding sensing region and the power input terminal.
3. The fingerprint sensor according to claim 1 , wherein each of the plurality of sensing regions comprises a plurality of columns of sensing units, and each of the plurality of switch circuits comprises one switch component, wherein the one switch component is coupled in a one-to-many manner between the plurality of columns of sensing units of the corresponding sensing region and the power input terminal.
4. The fingerprint sensor according to claim 1 , wherein one of the plurality of sensing regions is coupled to a readout circuit.
5. The fingerprint sensor according to claim 1 , wherein the first terminal of the second transistor of each of the plurality of sensing units in a same column is coupled to a same power line.
6. The fingerprint sensor according to claim 1 , wherein the second terminal of the third transistor of each of the plurality of sensing units in a same column is coupled to a same signal readout line.