# US 10,121,048 B2 · Operating method for a fingerprint sensing device and fingerprint sensing system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,048 B2 - Document ID: US10121048B2 - Status: Granted - Kind: B2 - Application number: 15/398,435 - Filed: 2017-01-04 - Published: 2018-02-01 - Granted: 2018-11-06 - Earliest claimed: 2016-07-29 - Assignees: Elan Microelectronics Corporation - Applicants: Elan Microelectronics Corporation - Inventors: Chao-Chi Yang; Jui-Che Lin; Tung-An Yao; Chung-Han Cheng; Chung-An Tang - Web page: https://patentgrep.com/patent/US10121048B2 ## CPC - G06V 40/1306: {non-optical, e.g. ultrasonic or capacitive sensing} - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A fingerprint sensing system has a fingerprint sensing device and a power supply circuit. The fingerprint sensing device has a high-voltage input terminal and a low-voltage input terminal. During scan phases of the fingerprint sensing device, the power supply circuit provides a first voltage to the high voltage input terminal and provides a second voltage to the low voltage input terminal. During the read phases of the fingerprint sensing device, the power supply circuit provides a third voltage to the high voltage input terminal and provides a fourth voltage to the low voltage input terminal. A first voltage difference is between the first voltage and the second voltage. A second voltage difference is between the third voltage and the fourth voltage. The first voltage difference is greater than the second voltage difference. ## Claims ### Claim 1 An operating method for a fingerprint sensing device, wherein the fingerprint sensing device comprises a high-voltage input terminal and a low-voltage input terminal, the high-voltage input terminal and the low-voltage input terminal are coupled to a power supply circuit to power the fingerprint sensing device for sensing a fingerprint, the method comprising: in a scan phase of the fingerprint sensing device, providing a first voltage to the high-voltage input terminal and providing a second voltage to the low-voltage input terminal to cause a first voltage difference between the high-voltage input terminal and the low-voltage input terminal, wherein the first voltage is greater than the second voltage; and in a read phase of the fingerprint sensing device, providing a third voltage to the high-voltage input terminal and providing a fourth voltage to the low-voltage input terminal to cause a second voltage difference between the high-voltage input terminal and the low-voltage input terminal, wherein the third voltage is greater than the fourth voltage; wherein the first voltage difference is greater than the second voltage difference. ### Claim 2 (depends on 1) The operating method as claimed in claim 1, wherein the read phase comprises a first read period and a second read period and the first read period is earlier than the second read period, wherein the step of providing the third voltage to the high-voltage input terminal is performed during the first read period to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal during the first read period; the operating method further comprises: providing a fifth voltage to the high-voltage input terminal during the second read period to generate a third voltage difference between the high-voltage input terminal and the low-voltage input terminal during the second read period, wherein the fifth voltage is less than the third voltage; wherein the third voltage difference is less than the second voltage difference. ### Claim 3 (depends on 1) The operating method as claimed in claim 1, wherein the scan phase comprises a first scan period and a second scan period, and the first scan period is earlier than the second scan period, wherein the step of providing the first voltage to the high-voltage input terminal and providing the second voltage to the low-voltage input terminal is performed during the second scan period to cause the first voltage difference between the high-voltage input terminal and the low-voltage input terminal during the second scan period; the operating method further comprises: providing a sixth voltage to the high-voltage input terminal and providing the fourth voltage to the low-voltage input terminal to cause a fourth voltage difference between the high-voltage input terminal and the low-voltage input terminal during the first scan period, wherein the sixth voltage is less than the first voltage and is greater than the third voltage; wherein the fourth voltage difference is not greater than the first voltage difference but is greater than the second voltage difference. ### Claim 4 (depends on 1) The operating method as claimed in claim 1, wherein a capacitor is coupled between the high-voltage input terminal and the low-voltage input terminal, the scan phase comprises a first scan period and a second scan period, and the first scan period is earlier than the second scan period; the operating method further comprises: providing a sixth voltage to the high-voltage input terminal and providing the fourth voltage to the low-voltage input terminal to cause a fourth voltage difference between the high-voltage input terminal and the low-voltage input terminal during the first scan period, wherein the sixth voltage is greater than the third voltage, and providing the second voltage to the low-voltage input terminal during the second scan period so as to implement the step of providing the first voltage to the high-voltage input terminal; wherein the fourth voltage difference is equal to the first voltage difference. ### Claim 5 (depends on 3) The operating method as claimed in claim 3, wherein the read phase comprises a first read period and a second read period and the first read period is earlier than the second read period, wherein the step of providing the third voltage to the high-voltage input terminal is performed during the first read period to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal during the first read period; the operating method further comprises: providing a fifth voltage to the high-voltage input terminal during the second read period to generate a third voltage difference between the high-voltage input terminal and the low-voltage input terminal during the second read period, wherein the fifth voltage is less than the third voltage; wherein the third voltage difference is less than the second voltage difference. ### Claim 6 (depends on 4) The operating method as claimed in claim 4, wherein the read phase comprises a first read period and a second read period and the first read period is earlier than the second read period, wherein the step of providing the third voltage to the high-voltage input terminal is performed during the first read period to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal during the first read period; the operating method further comprises: providing a fifth voltage to the high-voltage input terminal during the second read period to generate a third voltage difference between the high-voltage input terminal and the low-voltage input terminal during the second read period, wherein the fifth voltage is less than the third voltage; wherein the third voltage difference is less than the second voltage difference. ### Claim 7 (depends on 1) The operating method as claimed in claim 1, wherein the third voltage is less than an operating voltage provided to the power supply circuit. ### Claim 8 (depends on 1) The operating method as claimed in claim 1, wherein the fourth voltage is a ground voltage of the power supply circuit. ### Claim 9 (depends on 3) The operating method as claimed in claim 3, wherein the sixth voltage is equal to an operating voltage provided to the power supply circuit. ### Claim 10 (depends on 4) The operating method as claimed in claim 4, wherein the sixth voltage is equal to an operating voltage provided to the power supply circuit. ### Claim 11 A fingerprint sensing system comprising: a fingerprint sensing device comprising, a high-voltage input terminal and a low-voltage input terminal; and a power supply circuit coupled to the high-voltage input terminal and the low-voltage input terminal of the fingerprint sensing device, and supplying a first voltage, a second voltage, a third voltage and a fourth voltage, wherein the first voltage is greater than the second voltage, and the third voltage is greater than the fourth voltage; wherein in a scan phase of the fingerprint sensing device, the power supply circuit provides the first voltage to the high-voltage input terminal and provides the second voltage to the low-voltage input terminal to cause a first voltage difference between the high-voltage input terminal and the low-voltage input terminal; in a read phase of the fingerprint sensing device, the power supply circuit provides the third voltage to the high-voltage input terminal and provides the fourth voltage to the low-voltage input terminal to cause a second voltage difference between the high-voltage input terminal and the low-voltage input terminal; and the first voltage difference is greater than the second voltage difference. ### Claim 12 (depends on 11) The fingerprint sensing system as claimed in claim 11, wherein the power supply circuit comprises: a voltage boosting circuit providing the first voltage and the second voltage, wherein the first voltage is greater than the second voltage; a voltage regulator providing the third voltage; and a fourth voltage terminal for providing the fourth voltage, wherein the third voltage is greater than the fourth voltage. ### Claim 13 (depends on 12) The fingerprint sensing system as claimed in claim 12, wherein the voltage regulator further provides a fifth voltage, and the fifth voltage is greater than the fourth voltage and is less than the third voltage; wherein the read phase comprises a first read period and a second read period, and the first read period is earlier than the second read period; wherein during the first read period, the power supply circuit provides the third voltage to the high-voltage input terminal to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal, and during the second read period, the power supply circuit provides the fifth voltage to the high-voltage input terminal to cause a third voltage difference between the high-voltage input terminal and the low-voltage input terminal; wherein the third voltage difference is less than the second voltage difference. ### Claim 14 (depends on 12) The fingerprint sensing system as claimed in claim 12, wherein the power supply circuit further comprises a sixth voltage terminal for providing a sixth voltage, and the sixth voltage is less than the first voltage and is greater than the third voltage; the scan phase comprises a first scan period and a second scan period, and the first scan period is earlier than the second scan period; wherein during the first scan period, the power supply circuit provides the sixth voltage to the high-voltage input terminal and provides the fourth voltage to the low-voltage input terminal to cause a fourth voltage difference between the high-voltage input terminal and the low-voltage input terminal, and during the second scan period, the power supply circuit provides the first voltage to the high-voltage input terminal and provides the second voltage to the low-voltage input terminal to cause the first voltage difference between the high-voltage input terminal and the low-voltage input terminal; wherein the fourth voltage difference is not greater than the first voltage difference but is greater than the second voltage difference. ### Claim 15 (depends on 11) The fingerprint sensing system as claimed in claim 11, wherein the power supply circuit comprises: a voltage boosting circuit providing the second voltage; a voltage regulator providing the third voltage; a fourth voltage terminal for providing the fourth voltage, wherein the third voltage is greater than the fourth voltage; a sixth voltage terminal for providing the sixth voltage, wherein the sixth voltage is greater than the third voltage; and a capacitor coupled between the high-voltage input terminal and the low-voltage input terminal; wherein the scan phase of the fingerprint sensing device comprises a first scan period and a second scan period, and the first scan period is earlier than the second scan period; wherein during the first scan period, the power supply circuit provides the sixth voltage to the high-voltage input terminal and provides the fourth voltage to the low-voltage input terminal to cause a fourth voltage difference between the high-voltage input terminal and the low-voltage input terminal, and during the second scan period, the power supply circuit provides the second voltage to the low-voltage input terminal, thus providing the first voltage to the high-voltage input terminal during the scan phase is accomplished; wherein the fourth voltage difference is equal to the first voltage difference. ### Claim 16 (depends on 14) The fingerprint sensing system as claimed in claim 14, wherein the voltage regulator further provides a fifth voltage, and the fifth voltage is greater than the fourth voltage and is less than the third voltage; wherein the read phase comprises a first read period and a second read period, and the first read period is earlier than the second read period; wherein during the first read period, the power supply circuit provides the third voltage to the high-voltage input terminal to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal, and during the second read period, the power supply circuit provides the fifth voltage to the high-voltage input terminal to cause a third voltage difference between the high-voltage input terminal and the low-voltage input terminal; wherein the third voltage difference is less than the second voltage difference. ### Claim 17 (depends on 15) The fingerprint sensing system as claimed in claim 15, wherein the voltage regulator further provides a fifth voltage, and the fifth voltage is greater than the fourth voltage and is less than the third voltage; wherein the read phase comprises a first read period and a second read period, and the first read period is earlier than the second read period; wherein during the first read period, the power supply circuit provides the third voltage to the high-voltage input terminal to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal, and during the second read period, the power supply circuit provides the fifth voltage to the high-voltage input terminal to cause a third voltage difference between the high-voltage input terminal and the low-voltage input terminal; wherein the third voltage difference is less than the second voltage difference. ### Claim 18 (depends on 11) The fingerprint sensing system as claimed in claim 11, wherein the third voltage is less than an operating voltage supplied to the power supply circuit. ### Claim 19 (depends on 11) The fingerprint sensing system as claimed in claim 11, wherein the fourth voltage is a ground voltage of the power supply circuit. ### Claim 20 (depends on 14) The fingerprint sensing system as claimed in claim 14, wherein the sixth voltage is equal to an operating voltage provided to the power supply circuit. ### Claim 21 (depends on 15) The fingerprint sensing system as claimed in claim 15, wherein the sixth voltage is equal to an operating voltage provided to the power supply circuit. ### Claim 22 A fingerprint sensing device comprising: multiple sensors; and a high-voltage input terminal and a low-voltage input terminal, wherein the high-voltage input terminal and the low-voltage input terminal are for coupling to a power supply circuit that supplies power to the fingerprint sensing device for sensing a fingerprint by the multiple sensors; wherein the fingerprint sensing device comprises a scan phase and a read phase while sensing the multiple sensors, a first voltage difference is between the high-voltage input terminal and the low-voltage input terminal during the scan phase, and a second voltage difference is between the high-voltage input terminal and the low-voltage input terminal during the read phase; wherein the first voltage difference is greater than the second voltage difference. ### Claim 23 (depends on 22) The fingerprint sensing device as claimed in claim 22, wherein during the scan phase, the high-voltage input terminal and the low-voltage input terminal respectively receive a first voltage and a second voltage provided by the power supply circuit, and during the read phase, the high-voltage input terminal and the low-voltage input terminal respectively receive a third voltage and a fourth voltage provided by the power supply circuit, wherein the first voltage is greater than the second voltage and the third voltage is greater than the fourth voltage. ### Claim 24 (depends on 23) The fingerprint sensing device as claimed in claim 23, the read phase comprises a first read period and a second read period, and the first read period is earlier than the second read period; wherein during the first read period, the high-voltage input terminal and the low-voltage input terminal respectively receive the third voltage and the fourth voltage to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal; and during the second read period, the high-voltage input terminal receives a fifth voltage supplied from the power supply circuit, and the low-voltage input terminal receives the fourth voltage, such that a third voltage difference is caused between the high-voltage input terminal and the low-voltage input terminal, wherein the fifth voltage is less than the third voltage; wherein the third voltage difference is less than the second voltage difference. ### Claim 25 (depends on 23) The fingerprint sensing device as claimed in claim 23, wherein the scan phase comprises a first scan period and a second scan period, and the first scan period is earlier than the second scan period; wherein during the second scan period, the high-voltage input terminal and the low-voltage input terminal respectively receive the first voltage and the second voltage to cause the first voltage difference between the high-voltage input terminal and the low-voltage input terminal, and during the first scan period, the high-voltage input terminal receives a sixth voltage supplied from the power supply circuit, and the low-voltage input terminal receives the fourth voltage, such that a fourth voltage difference is caused between the high-voltage input terminal and the low-voltage input terminal during the first scan period, wherein the sixth voltage is less than the first voltage and greater than the third voltage; wherein the fourth voltage difference is not greater than the first voltage difference but is greater than the second voltage difference. ### Claim 26 (depends on 25) The fingerprint sensing device as claimed in claim 25, the read phase comprises a first read period and a second read period, and the first read period is earlier than the second read period; wherein during the first read period, the high-voltage input terminal and the low-voltage input terminal respectively receive the third voltage and the fourth voltage to cause the second voltage difference between the high-voltage input terminal and the low-voltage input terminal; and during the second read period, the high-voltage input terminal receives a fifth voltage supplied from the power supply circuit, and the low-voltage input terminal receives the fourth voltage, such that a third voltage difference is caused between the high-voltage input terminal and the low-voltage input terminal, wherein the fifth voltage is less than the third voltage; wherein the third voltage difference is less than the second voltage difference. ### Claim 27 (depends on 23) The fingerprint sensing device as claimed in claim 23, wherein the third voltage is less than an operating voltage supplied to the power supply circuit. ### Claim 28 (depends on 23) The fingerprint sensing device as claimed in claim 23, wherein the fourth voltage is a ground voltage of the power supply circuit. ### Claim 29 (depends on 25) The fingerprint sensing device as claimed in claim 25, wherein the sixth voltage is equal to an operating voltage provided to the power supply circuit.