Patent ID: 11908415
Assignee: GOOGLE LLC
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 16:
17. An electronics-implemented method, comprising:
receiving, at a computing device, an indication to activate an under-display fingerprint sensor that is located underneath a display of the computing device;
activating a collection of LEDs of the display to provide illumination for the under-display fingerprint sensor, including activating an LED in the collection of LEDs by:
establishing, by drive circuitry of the LED during a first programming stage of the drive circuitry, a first overdriven voltage across a gate terminal of an LED-driving transistor that is arranged to energize the LED and a source terminal of the LED-driving transistor, the first overdriven voltage being a first excess voltage in excess of a steady state voltage;
emitting, by the LED during a first emission stage that follows the first programming stage, a first light intensity that is less than a steady state light intensity by a first deficient intensity;
establishing, by the drive circuitry of the LED during a second programming stage of the drive circuitry that follows the first emission stage, a second overdriven voltage across the gate terminal of the LED-driving transistor and the source terminal of the LED-driving transistor, the second overdriven voltage being a second excess voltage in excess of the steady state voltage, the second excess voltage being less than the first excess voltage, a voltage difference between the second overdriven voltage and the steady state voltage being less than a voltage difference between the first overdriven voltage and the steady state voltage;
emitting, by the LED during a second emission stage that follows the second programming stage, a second light intensity that is less than the steady state light intensity by a second deficient intensity, an absolute amount of the second deficient intensity being less than an absolute amount of the first deficient intensity;
establishing, by the drive circuitry of the LED during a steady state programming stage of the drive circuitry that follows the second emission stage, the steady state voltage across the gate terminal of the LED-driving transistor and the source terminal of the LED-driving transistor; and
emitting, by the LED during a steady-stage emission stage that follows the steady state programming stage, the steady state light intensity;
establishing, by the drive circuitry of the LED during multiple steady state programming stages of the drive circuitry that follow the steady state programming stage, the steady state voltage across the gate terminal of the LED-driving transistor and the source terminal of the LED-driving transistor, so that the LED emits at a steady state light intensity for multiple contiguous frames of the display; and
activating the under-display fingerprint sensor by reading a signal from the under-display fingerprint sensor while the collection of LEDs is activated, including while the LED is emitting the steady state light intensity.