Event-Driven Solid-State Imaging Device for Fingerprint Authentication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CMOS-based fingerprint sensors face challenges in dark environments, narrow dynamic range, and light interference, which affect their performance and accuracy.
Innovation Solution
A solid-state imaging device with event-driven pixels and a control unit that sets two thresholds and a region of interest (ROI) to enhance authentication accuracy, particularly in dark conditions, by differentiating between high-contrast and low-contrast luminance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a CMOS sensor is used for fingerprint authentication, then the device can acquire fingerprint information, but the performance deteriorates in dark places and the dynamic range becomes narrow due to light interference
Solution Approach 1:
The patent implements dynamic threshold adjustment where the threshold value changes based on detected light conditions. The control unit adjusts the threshold dynamically to adapt to varying light environments, allowing the sensor to maintain high sensitivity in dark places while filtering out noise in brighter conditions. This dynamic adaptation resolves the contradiction between maintaining measurement precision across different lighting conditions and rejecting light interference.
Solution Approach 2:
The patent changes the operational parameters of the sensor by adjusting the threshold value based on light reception conditions. When the light receiving unit detects specific light patterns, the control unit modifies the threshold parameter to optimize fingerprint detection. This parameter change enables the system to differentiate between authentic fingerprint signals and noise caused by ambient light, thereby improving authentication accuracy in varying light environments.
2Device complexity
If a fixed threshold is used for event-driven pixels, then the device structure remains simple, but the authentication accuracy deteriorates in varying light conditions
Solution Approach 1:
The patent implements a feedback mechanism where the light receiving unit continuously monitors light conditions and provides information to the control unit. Based on this feedback, the control unit automatically adjusts the threshold value for event-driven pixels. This feedback loop enables the system to maintain high authentication accuracy across varying light conditions without requiring complex manual intervention, effectively resolving the contradiction between device simplicity and measurement precision.
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
The solution enables high-accuracy fingerprint authentication with noise immunity, even in dark environments, by effectively distinguishing between authentic fingerprint data and noise, thus improving performance and reliability.
Implementation Method 1
a light receiving unit (16) including event-driven pixels (40) that output, as event data, the occurrence of an event on the basis of a threshold
Data Source
AI summary
The present invention relates to a solid-state imaging device capable of highly accurate authentication.The solid-state imaging device includes a light receiving unit and a control unit. The light receiving unit includes event-driven pixels that output the occurrence of an event on the basis of a threshold. The control unit is a control unit that controls the light receiving unit, and is configured to set a first threshold for the event-driven pixels, and, in a case where an event based on the first threshold has been detected, set a second threshold smaller than the first threshold for the event-driven pixels.