Under-Display Fingerprint Sensor Brightness Control With Voltage Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic devices face challenges in integrating sensors, such as fingerprint scanners, under the display panel, which require longer stabilization times for pixel brightness adjustment, affecting overall fingerprint authentication speed.
Innovation Solution
Implementing data and supply voltage compensation to overdrive pixel circuits, reducing stabilization time by adjusting data and supply voltage signals to rapidly increase pixel brightness for under-display sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pixels are raised to high brightness to reduce integration time, then fingerprint authentication speed is improved, but pixel stabilization time increases
Solution Approach 1:
The system performs preliminary actions by pre-calculating and pre-applying voltage compensation factors to the pixel circuit before the actual fingerprint sensing operation. This allows the pixel to rapidly transition to high brightness without requiring long stabilization time, as the voltage compensation is already in place to accelerate the charging process of the OLED capacitor.
Solution Approach 2:
The system changes electrical parameters by applying overdriven voltage through data voltage compensation and supply voltage compensation. By increasing the voltage supplied to the pixel circuit beyond normal operating levels, the system accelerates the charging rate of the OLED capacitor, enabling faster brightness transition while maintaining control over the final stable brightness level.
2Speed
If integration time is reduced by raising pixel brightness, then sensor response speed is improved, but energy consumption increases
Solution Approach 1:
The system applies periodic voltage compensation in multiple stages: an initial overdriven voltage is applied to rapidly charge the OLED capacitor, then subsequent voltage adjustments bring the system to a stable operating point. This periodic action allows the pixel to achieve high brightness quickly while minimizing total energy consumption by avoiding continuous overdriven voltage application.
Solution Approach 2:
The system dynamically changes voltage parameters through two-stage compensation: first applying a high overdriven voltage to accelerate charging, then reducing to a controlled stable voltage. This parameter change strategy enables fast sensor response while optimizing energy consumption by not maintaining excessive voltage levels throughout the entire operation.
3Stability of the object's composition
If multiple frame times are used for stabilization, then pixel brightness stability is improved, but authentication time increases
Solution Approach 1:
The system implements feedback through voltage compensation that monitors and adjusts the charging state of the OLED capacitor in real-time. By using feedback information about the actual charging progress, the system can determine when sufficient stability has been achieved without requiring a fixed number of frame times, thus reducing authentication time while maintaining adequate brightness stability.
Solution Approach 2:
The system transitions from static, fixed-duration stabilization to dynamic, adaptive stabilization. By applying voltage compensation that adjusts based on actual charging conditions, the system can achieve brightness stability in fewer frame times when conditions permit, while automatically extending stabilization when necessary, thus optimizing authentication time dynamically.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the time required for fingerprint authentication by shortening pixel stabilization time, enhancing the speed and efficiency of sensor integration.
Implementation Method 1
establishing an overdriven voltage across a driving transistor of a pixel to increase current flowing through an OLED of the pixel
Implementation Method 2
activating an LED in the collection of LEDs by establishing a first overdriven voltage across a gate terminal of an LED-driving transistor that is arranged to energize the LED
Data Source
AI summary
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for brightness control for under-display fingerprint sensor are disclosed. A method includes receiving, at a computing device, an indication to activate an under-display 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 sensor, including activating an LED in the collection of LEDs by: establishing, by drive circuitry of the LED, a first overdriven voltage across an LED-driving transistor that is arranged to energize the LED; establishing a second overdriven voltage across the LED-driving transistor; and establishing a steady state voltage across the LED-driving transistor; and activating the under-display sensor by reading a signal from the under-display sensor once the collection of LEDs has activated, including once the steady state voltage has been programmed across the LED-driving transistor.