On-screen Optical Fingerprint Capture via Internal Reflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fingerprint sensors on mobile devices occupy valuable space on the front face, leading to trade-offs between display size and sensor size, resulting in less accurate user authentication and an interrupted user experience due to the need for separate fingerprint scanning.
Innovation Solution
An on-screen optical fingerprint capture method using a camera within the display assembly, where light reflected from a fingertip propagates through a low refractive index layer within the cover glass, allowing internal reflection and capture of fingerprint images without a dedicated scanning surface, enabling authentication while maintaining a seamless user interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated fingerprint sensor is placed on the front face of the device, then fingerprint authentication can be performed, but the display area is reduced and device dimensions are increased
Solution Approach 1:
The fingerprint sensor is merged with the display assembly by integrating the camera and optical components within the display structure. The camera is positioned to capture fingerprints through the display layers, combining the display and fingerprint sensing functions into a single integrated component, thereby eliminating the need for a separate dedicated sensor area on the front face.
Solution Approach 2:
The display assembly is given multiple functions: it serves as both the visual display interface and the fingerprint sensing surface. The camera within the display assembly captures fingerprints using light propagated through the display layers, allowing the same structural component to perform both display and biometric authentication functions simultaneously.
2Reliability
If a separate fingerprint scanning surface is provided, then authentication can be performed, but user interaction is interrupted and user experience is degraded
Solution Approach 1:
The fingerprint sensing function is merged into the display assembly, allowing users to provide their fingerprint on the same surface they are interacting with for display purposes. This eliminates the need to move their finger from the display to a separate sensor, maintaining continuous user interaction flow.
Solution Approach 2:
The display assembly serves itself by incorporating the fingerprint capture capability within its structure. The camera and optical components within the display assembly enable it to perform authentication functions without requiring external dedicated hardware, making the system self-sufficient and streamlining the user experience.
3Area of stationary object
If the sensing area is made smaller to maintain display dimensions, then device size is reduced, but authentication accuracy decreases
Solution Approach 1:
The fingerprint capture is achieved through the display layers by propagating light through multiple layers including the touch sensor and display panels. This three-dimensional optical path through the display assembly allows the camera to capture fingerprint details without requiring a large dedicated surface area, effectively utilizing the depth dimension of the display structure.
Solution Approach 2:
Light acts as an intermediary medium to transmit fingerprint information from the contact point through the display layers to the camera. The optical path through the display assembly layers serves as a mediator, enabling the camera to capture fingerprint details at a distance without direct contact, thus maintaining accuracy while reducing the required sensing surface area.
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 solution allows for unobtrusive user authentication without a separate fingerprint scanning surface, enhancing accuracy and user experience by integrating fingerprint capture into the display assembly, thus optimizing device design and functionality.
Implementation Method 1
light reflected from a fingertip and propagated within a glass layer of a display assembly
Data Source
AI summary
Example methods, systems, computer-readable media, and apparatuses for on-screen optical fingerprint capture for user authentication are presented. These allow for the authentication of a fingerprint where the fingerprint image is propagated in a glass layer before being captured by a camera. In some examples, such propagation can result in multiple fingerprint images resulting from total internal reflection within the glass layer. Feature information can then be determined from the captured image of the fingerprint, which can include multiple fingerprint images. The amount of feature information can then be reduced. A histogram associated with the captured image based on the reduced number of features can be generated, and a user can be authenticated based on the histogram.