Integrated Display and Sensing Apparatus for Under-Display Fingerprint Recognition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing under-display fingerprint sensors face challenges in performance and cost due to limited space on the backplane for display pixel circuits, which affects light intensity and manufacturing complexity.
Innovation Solution
An integrated display and sensing apparatus is developed, where display pixel circuits and sensing pixel circuits are formed on the same substrate, allowing for a display pixel circuit-sharing scheme to reduce the area occupied by display pixel circuits, thereby freeing space for sensing pixel circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If sensing pixel circuits are disposed above the light source on the backplane, then the light intensity reaching the finger is decreased, but the manufacturing cost and complexity of the sensing layer is increased
Solution Approach 1:
The patent transitions from a planar arrangement where sensing circuits are stacked above light sources on the backplane to a spatial arrangement where light emitting elements are positioned between the backplane and the finger. This dimensional reorganization allows light to travel directly through the display structure to the finger and reflect back to sensors, eliminating the need for complex sensing layers above the light source while maintaining or improving light intensity.
Solution Approach 2:
The display structure itself is made to serve dual functions: displaying visual information and enabling fingerprint sensing. The light emitting elements and display layers are configured to also act as the illumination source and optical path for fingerprint recognition, eliminating the need for separate dedicated sensing components and reducing manufacturing complexity.
2Area of stationary object
If sensing pixel circuits are disposed above the light source, then space on the backplane is limited, but the aperture ratio of sensing pixel cells is reduced
Solution Approach 1:
The patent moves the sensing function from the backplane dimension to the display layer dimension. By positioning light emitting elements and sensors within the display structure itself rather than confining them to the backplane, the aperture ratio of sensing pixel cells can be increased without constraining the backplane area, as the sensing operations occur in a different spatial plane.
Solution Approach 2:
The display structure and sensing structure are merged into a single integrated system. The same layers that constitute the display (light emitting elements, pixel circuits, cover layer) are configured to simultaneously serve as the fingerprint sensing components, thereby increasing the aperture ratio of sensing pixel cells while utilizing the existing display structure rather than requiring separate dedicated sensing space.
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 enhances the performance of under-display fingerprint recognition by increasing the aperture ratio of sensing pixel cells and reducing manufacturing costs through efficient use of space on the backplane.
Implementation Method 1
at least one optical sensing element of the array of optical sensing elements is configured to detect optical information of the object based, at least in part, on light generated by at least one light emitting element of the array of light emitting elements and reflected by the object
Data Source
AI summary
An apparatus includes a backplane, a light emitting layer, a sensing layer, and a cover layer. The backplane includes an array of display pixel circuits and an array of sensing pixel circuits formed on a same substrate. The light emitting layer includes an array of light emitting elements above the backplane. Each display pixel circuit is configured to drive a plurality of light emitting elements. The sensing layer includes an array of optical sensing elements above the light emitting layer. Each sensing pixel circuit is configured to drive a respective optical sensing element. The cover layer is above the sensing layer. When an object is in contact with the cover layer, at least one optical sensing element is configured to detect optical information of the object based, at least in part, on light generated by at least one light emitting element and reflected by the object.