Invention Grant
- Patent Title: Fingerprint sensing system with sensing reference potential providing circuitry
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Application No.: US15399124Application Date: 2017-01-05
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Publication No.: US09953204B2Publication Date: 2018-04-24
- Inventor: Rolf Sundblad , Emil Hjalmarson , Erik Säll , Allan Olsson , Klaas-Jan De Langen
- Applicant: Fingerprint Cards AB
- Applicant Address: SE Göteborg
- Assignee: FINGERPRINT CARDS AB
- Current Assignee: FINGERPRINT CARDS AB
- Current Assignee Address: SE Göteborg
- Agency: RMCK Law Group PLC
- Priority: SE1650548 20160422
- Main IPC: G06K9/00
- IPC: G06K9/00 ; H02M3/07 ; G06K9/03

Abstract:
A fingerprint sensing system comprising a device connection interface including a device reference potential input, a sensing arrangement, and sensing reference potential providing circuitry. The sensing arrangement includes multiple sensing structures and read-out circuitry connected to each of the sensing structures. The sensing reference potential providing circuitry provides a sensing reference potential to the sensing arrangement in the form of a sensing reference signal alternating between a first sensing reference potential and a second sensing reference potential, and comprises a first capacitor; a second capacitor; charging circuitry; and switching circuitry for alternatingly switching the sensing reference potential providing circuitry between a first state in which the first capacitor and the second capacitor are connected in parallel to the charging circuitry; and a second state in which the first capacitor and the second capacitor, when charged, are connected in series between the device reference potential input and the sensing arrangement.
Public/Granted literature
- US20170308730A1 FINGERPRINT SENSING SYSTEM WITH SENSING REFERENCE POTENTIAL PROVIDING CIRCUITRY Public/Granted day:2017-10-26
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