Fingerprint Capture Initiation via Touch Screen Validation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fingerprint sensor wake-up schemes that rely on physical button presses or electrical contact measurements are impractical and inaccurate when the fingerprint sensor is integrated within the active display area, leading to false rejections and increased power consumption.
Innovation Solution
A system that uses a touch screen sensor to initiate fingerprint capture by first detecting finger presence in a low-power doze mode and then validating the touch in a validation mode, allowing direct communication between touch and display controllers to illuminate the fingerprint area and reduce latency and power consumption without waking the host processor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wake-up schemes using physical button presses or electrical contact measurements are used, then the fingerprint sensor can be activated, but the device experiences increased power consumption and false rejections when the sensor is integrated within the active display area
Solution Approach 1:
The patent introduces a touch controller as an intermediary component that mediates between the user's touch input and the fingerprint sensor activation. The touch controller detects touch events on the display surface and communicates with the fingerprint sensor controller to trigger fingerprint capture, eliminating the need for physical button presses and improving both reliability and power efficiency
Solution Approach 2:
The display screen serves multiple functions: it acts as both the visual output device and the touch-sensitive interface for initiating fingerprint capture. By integrating the touch controller with the display, the system eliminates separate wake-up buttons and uses the universal touch interface to trigger fingerprint sensing, reducing component count and improving reliability
2Speed
If the fingerprint sensor is continuously active to ensure immediate response, then detection speed is improved, but power consumption increases significantly
Solution Approach 1:
The system performs preliminary touch detection through the touch controller before activating the fingerprint sensor. The touch controller continuously monitors the display surface for touch events in a low-power state, and only activates the fingerprint sensor when a valid touch is detected, thereby maintaining fast response while minimizing power consumption
Solution Approach 2:
The fingerprint sensor operates in dynamic power states, switching between active and sleep modes based on touch events. The system dynamically adjusts the operational state of the fingerprint sensor controller based on signals from the touch controller, ensuring immediate response when needed while conserving power during idle periods
3Ease of operation
If physical button presses are used to wake up the fingerprint sensor, then the activation process is simple, but the device complexity increases and usability is reduced when the sensor is integrated within the display area
Solution Approach 1:
The patent merges the touch interface and fingerprint sensor activation functions into a single integrated system. The touch controller and fingerprint sensor controller communicate directly, allowing the display surface itself to serve as the activation interface, thereby simplifying the user experience while managing device complexity through integrated communication protocols
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A method for initiating fingerprint capture in an electronic device is described. The device includes a touch screen with a sensing region, a touch controller, a fingerprint controller, and a host. The device is placed in a low power doze mode where the fingerprint controller is in a low power state and the device scans for an object proximate to the sensing region. When an object is proximate to the sensing region, the device executes a validation mode to determine whether the object is a fingerprint. When a fingerprint is detected, the device sends a wake up signal to the fingerprint controller and places the fingerprint controller in a high power mode. One or more fingerprint images are then captured.