US 12,205,401 B2
Readout integrated circuit
Chi-Ting Chen, Hsinchu (TW)
Assigned to Novatek Microelectronics Corp., Hsinchu (TW)
Filed by Novatek Microelectronics Corp., Hsinchu (TW)
Filed on Nov. 13, 2022, as Appl. No. 17/985,895.
Application 17/985,895 is a continuation in part of application No. 17/168,185, filed on Feb. 5, 2021, granted, now 11,503,241.
Claims priority of provisional application 62/970,713, filed on Feb. 6, 2020.
Prior Publication US 2023/0070145 A1, Mar. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06V 40/13 (2022.01)
CPC G06V 40/1318 (2022.01) 28 Claims
OG exemplary drawing
 
1. A readout integrated circuit, configured to read out sensing signals from an optical sensing panel comprising a sensor array for fingerprint sensing, the readout integrated circuit comprising:
a plurality of input terminals, configured to be coupled to a plurality of output terminals of the optical sensing panel;
a first discharging circuit, coupled to one of the plurality of input terminals and configured to discharge an output terminal included in the plurality of output terminals of the optical sensing panel by a first current during a readout period, wherein the readout integrated circuit reads out a voltage of the output terminal of the optical sensing panel as a sensing signal; and
a pre-charging circuit, coupled to the output terminal of the optical sensing panel, wherein the pre-charging circuit is configured to charge the output terminal of the optical sensing panel to an initial voltage during a pre-charging period, and the initial voltage is lower than and approximate to a highest input voltage of an analog-to-digital converter, wherein the pre-charging period is earlier than the readout period,
wherein the first discharging circuit comprises:
a first switch element, controlled to be either conducted or not by a control signal, wherein a first terminal of the first switch element is coupled to the output terminal of the optical sensing panel, and a control terminal of the first switch element is coupled to the control signal; and
a first current source, coupled to a second terminal of the first switch element, wherein the first current source is configured to generate the first current.