In-Display Fingerprint Sensor Using Red Green OLED Light Sources
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Solution Overview
Problem
Existing display panels with fingerprint identification modules suffer from reduced precision due to direct light irradiation on the fingerprint identification unit and a lower screen-to-body ratio, which also affects the user experience and design trends.
Innovation Solution
Incorporating a fingerprint identification unit within the display region close to the array substrate, utilizing a combination of red and green organic light emitting units as light sources for fingerprint identification, while minimizing the transparent area opposite to the display side to reduce stray light and enhance reflection-based fingerprint detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fingerprint identification module is arranged in the non-display region of the display panel, then the fingerprint identification function is achieved, but the screen-to-body ratio is reduced
Solution Approach 1:
The patent merges the fingerprint identification module with the display region by placing it at the side of organic light emitting units within the display area. This integration allows the fingerprint identification function to be achieved while maintaining the screen-to-body ratio, as the module occupies space that would otherwise be part of the display region rather than reducing the overall screen area.
Solution Approach 2:
The organic light emitting units serve dual functions: they generate light for display purposes and simultaneously serve as light sources for the fingerprint identification module. This multi-functionality eliminates the need for separate light sources and allows the fingerprint identification feature to be integrated within the display region without compromising the screen-to-body ratio.
2Reliability
If the fingerprint identification module is arranged on the surface opposite to the light exiting side, then the fingerprint identification function is achieved, but the light rays directly irradiate the fingerprint identification unit forming noise
Solution Approach 1:
The patent introduces a touch body (such as a finger) as an intermediary between the light source and the fingerprint identification unit. The light rays emitted by the organic light emitting units must reflect through the touch body to reach the fingerprint identification unit, which eliminates direct irradiation and the associated noise, thereby improving fingerprint identification precision.
Solution Approach 2:
Instead of placing the fingerprint identification unit on the opposite surface where light directly irradiates it, the patent inverts the arrangement by positioning it within the display region at the side of the organic light emitting units. This inversion changes the light path so that light must reflect through the touch body rather than directly irradiating the sensor, thereby reducing noise.
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 configuration improves fingerprint identification precision by reducing stray light and noise, maintaining a higher screen-to-body ratio, and aligning with design trends of edge-narrowing displays.
Implementation Method 1
At least one of the red organic light emitting unit and the green organic light emitting unit emits light in a fingerprint identification phase, and serves as a light source for the fingerprint identification unit
Implementation Method 2
The at least one fingerprint identification unit is configured to perform fingerprint identification according to light rays reflected on the at least one fingerprint identification unit by a touch body
Implementation Method 3
Compared with the blue organic light emitting unit, at least one of the red organic light emitting unit and the green organic light emitting unit serving as the light source for the fingerprint identification unit has a smaller transparent area towards a side opposite to a display side of the display panel. Therefore, stray light directly irradiated on the fingerprint identification unit without being reflected through the touch body is reduced
Data Source
AI summary
A display panel and an electronic device are provided. The display panel includes: an array substrate; a plurality of organic light emitting units disposed on the array substrate; at least one fingerprint identification unit located in a display region at a side close to the array substrate of the organic light emitting units. The fingerprint identification unit performs fingerprint identification according to light rays reflected on the fingerprint identification unit by a touch body. Each organic light emitting unit includes a red organic light emitting unit, a green organic light emitting unit and a blue organic light emitting unit. In a fingerprint identification phase, the red/green organic light emitting unit emits light to be a light source for the fingerprint identification unit. Compared with the blue organic light emitting unit, the red/green organic light emitting unit has a smaller transparent area towards a side opposite to a display side.