Fingerprint Sensor Power Management via Touch-Triggered Light Emission
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Solution Overview
Problem
Fingerprint sensors in electronic devices consume unnecessary power when the device is in a sleep state, especially when an optical sensor requires a light source and processes non-fingerprint objects, leading to performance degradation and increased power consumption.
Innovation Solution
Incorporating a touch sensor and display panel that can emit light only when a fingerprint is detected, allowing the processor to remain in a low power state until a valid fingerprint pattern is recognized, thereby filtering out non-fingerprint events and reducing unnecessary power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fingerprint sensor is kept awake for continuous operation, then fingerprint recognition is always available, but power consumption increases unnecessarily
Solution Approach 1:
The touch sensor performs preliminary detection of external objects before the fingerprint sensor is activated. When a touch event is detected, this triggers the fingerprint sensor to wake up and perform recognition, avoiding continuous operation while ensuring readiness when needed
Solution Approach 2:
The fingerprint sensor operates in periodic cycles rather than continuously. It remains in sleep mode and only activates periodically or event-driven when a touch is detected, maintaining recognition capability while reducing overall power consumption
2Measurement precision
If the display emits light continuously to support optical fingerprint sensing, then fingerprint recognition accuracy is maintained, but power consumption increases
Solution Approach 1:
The display emits light periodically or event-driven rather than continuously. Light emission is triggered only when a touch event is detected, providing illumination for fingerprint sensing only when needed, thus maintaining accuracy while reducing power consumption
Solution Approach 2:
The display light is activated preliminarily when a touch event is detected, preparing the optical path for fingerprint sensing before the actual recognition occurs, ensuring accuracy is maintained when needed
3Ease of operation
If the processor processes all touch events including non-fingerprint objects, then all inputs are handled, but power consumption increases due to unnecessary processing
Solution Approach 1:
The processing workflow is segmented into multiple stages: touch sensor detection, preliminary filtering of non-fingerprint events, fingerprint sensor activation only for valid touches, and processor involvement only when fingerprint recognition is required. This segmentation ensures the processor handles only necessary operations
Solution Approach 2:
The touch sensor and fingerprint sensor act as intermediaries that filter and pre-process input events before they reach the processor. Non-fingerprint events are discarded by these intermediate components, preventing unnecessary processor activation and reducing power consumption
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 power consumption by ensuring the fingerprint sensor only activates when a valid fingerprint is present, minimizing unnecessary processing and light usage, thus enhancing device performance and battery life.
Implementation Method 1
a display panel that emits light
Implementation Method 2
an optical sensor module located below the touch screen to provide optical fingerprint sensing
Data Source
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AI summary
Disclosed is an electronic device. The electronic device according to an embodiment may include a display including a touch sensor, a fingerprint sensor formed in at least a partial area of the display, a processor and a control circuit that controls the touch sensor. The control circuit may detect an input related to an external object through the at least a partial area while the processor is in a low power state, determine whether the external object is an input related to the fingerprint sensor, when the external object is not an input related to the fingerprint sensor, discard the input of the external object, and when the external object is an input related to the fingerprint sensor, emit light through a display area at least including the at least partial area in the low power state. In addition, various embodiments understood through the disclosure may be possible.