Under-Display Fingerprint Sensor Layout Without a Separate Light Source
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Solution Overview
Problem
Existing display devices require a separate or external light source for fingerprint recognition, which increases thickness and manufacturing costs, and may compromise resolution and reliability.
Innovation Solution
Incorporating a fingerprint recognition sensor layer under the display panel with a light blocking layer that includes holes for light passage, utilizing light emitted from subpixels for fingerprint recognition, eliminating the need for a separate light source and allowing for reduced thickness and improved alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate light source is used for fingerprint recognition, then fingerprint recognition can be achieved, but device thickness increases and manufacturing costs increase
Solution Approach 1:
The patent merges the light source function with the display panel by using the display panel's own light emission capability. The fingerprint recognition sensor layer is integrated with the display panel structure, eliminating the need for a separate light source. The light blocking layer with holes allows light from the display panel to reach the sensor, combining display and fingerprint recognition functions into a single integrated structure.
Solution Approach 2:
The display panel serves multiple functions: it displays images and simultaneously provides light for fingerprint recognition. The light blocking layer serves dual purposes of controlling light for display and enabling light passage for fingerprint sensing through its holes. This multi-functionality eliminates the need for dedicated separate components.
2Reliability
If a separate light source is used for fingerprint recognition, then fingerprint recognition can be achieved, but manufacturing costs increase
Solution Approach 1:
The patent combines the fingerprint recognition sensor layer with the display panel manufacturing process. The light blocking layer is formed as part of the display panel structure, and the sensor layer is integrated during the same manufacturing sequence. This merging eliminates the need for separate assembly of external light sources and reduces overall manufacturing complexity and cost.
Solution Approach 2:
The display panel manufacturing process is made universal to produce both display functionality and fingerprint recognition capability simultaneously. The same manufacturing steps produce the light emitting elements, the light blocking layer with holes, and the sensor layer integration, eliminating the need for separate production lines or additional component assembly.
3Reliability
If light blocking layer with holes is used, then light passage for fingerprint recognition is enabled, but alignment precision must be optimized
Solution Approach 1:
The light blocking layer with holes is formed in advance during the display panel manufacturing process, before final assembly. The holes are pre-positioned with precise alignment to the sensor layer and light emitting elements. This preliminary formation of the light blocking structure ensures proper alignment is built into the manufacturing process itself, reducing the need for post-assembly alignment adjustments.
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
Enables fingerprint recognition without a separate light source, reducing device thickness and manufacturing costs while enhancing recognition accuracy and reliability by using light emitted from subpixels and optimizing hole pitches for improved fingerprint recognition characteristics.
Implementation Method 1
light reflected by a finger touching the cover window passes
Implementation Method 2
organic light emitting diodes (OLEDs) that generate light through recombination of electrons and holes
Data Source
AI summary
Provided is a display device. The display device includes a display panel which includes a base substrate, a thin-film transistor layer on the base substrate, and a light emitting element layer comprising light emitting elements on the thin-film transistor layer; a cover window on the light emitting element layer of the display panel; and a fingerprint recognition sensor layer under the display panel. The base substrate includes a first base, a second base on the first base, and a light blocking layer between the first base and the second base, and the light blocking layer includes holes through which light reflected by a finger touching the cover window passes.