Under-Screen Optical Fingerprint Module for Larger Display Areas
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Solution Overview
Problem
Existing mobile terminals with fingerprint unlock structures outside the display screen occupy a large non-display area, reducing the screen-to-body ratio.
Innovation Solution
Integrate an optical fingerprint module under the display screen, allowing fingerprint detection through the display screen, with the detection area positioned within the display area, and using a protective layer with a through hole for light transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fingerprint unlock structure is disposed outside the display screen, then fingerprint recognition function is achieved, but the non-display area increases and screen-to-body ratio decreases
Solution Approach 1:
The patent merges the fingerprint unlock structure with the display screen by integrating the optical fingerprint module under the display screen. The fingerprint detection area is positioned within the display area, allowing the display screen to serve dual purposes: displaying information and enabling fingerprint recognition. This integration eliminates the need for a separate dedicated area on the front panel, thereby reducing non-display area while maintaining fingerprint recognition functionality.
Solution Approach 2:
The patent transitions the fingerprint unlock structure from a two-dimensional surface arrangement (on the front panel) to a three-dimensional integration (under the display screen). By placing the optical fingerprint module in the vertical dimension beneath the display screen, the solution utilizes the Z-axis space, allowing light to pass through the display screen to reach the fingerprint detection area. This dimensional change enables fingerprint recognition without occupying additional front panel area.
2Reliability
If a fingerprint unlock structure is disposed outside the display screen, then fingerprint recognition function is achieved, but the screen-to-body ratio decreases
Solution Approach 1:
The patent combines the fingerprint recognition function with the display area by positioning the fingerprint detection area within the display area. This merging allows the display screen to fulfill both display and authentication functions, maximizing the utilization of the display area and eliminating the need for separate non-display areas, thereby improving the screen-to-body ratio.
3Area of stationary object
If the optical fingerprint module is disposed under the display screen, then the display area increases, but light transmission to the fingerprint detection area must be ensured
Solution Approach 1:
The patent introduces an optical clear adhesive as an intermediary between the display screen and the optical fingerprint module. This adhesive layer with high light transmittance (not less than 90%) serves as a mediator that allows light to effectively pass from the display screen through the adhesive to reach the fingerprint detection area, ensuring sufficient illumination for fingerprint recognition while maintaining the integrated structure.
Solution Approach 2:
The patent optimizes the light transmittance parameter of the optical clear adhesive to be not less than 90%. By controlling and adjusting this physical parameter, the solution ensures that sufficient light can penetrate through the adhesive layer to reach the fingerprint detection area, thereby maintaining effective fingerprint recognition functionality while allowing the display area to be maximized.
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
Increases the display area by eliminating the need for a dedicated space on the front panel, enhancing the screen-to-body ratio without altering the front panel size.
Implementation Method 1
light is able to be transmitted through the display screen to the fingerprint detection area
Implementation Method 2
light transmittance of the optical clear adhesive is not less than 90%
Data Source
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AI summary
A display module and a mobile terminal are provided. The display module includes a display screen and an optical fingerprint module, where the optical fingerprint module is located on a surface of the display screen away from a light-out surface and is fixedly connected to the display screen, a vertical projection of a fingerprint detection area of the optical fingerprint module on the light-out surface of the display screen is located inside a display area of the display screen, and light is able to be transmitted through the display screen to the fingerprint detection area. In the foregoing technical solution, the optical fingerprint module is used to detect a fingerprint, and the optical fingerprint module is disposed under the display screen, so that a fingerprint can be collected when a finger presses the screen. Different from a mobile terminal in the prior art, because the optical fingerprint module is disposed under the display screen, no space of a front panel of the mobile terminal needs to be occupied, and more space can be used for disposition of the display screen, thereby increasing an area of the display screen, increasing a display size of the mobile terminal, and improving a screen-to-body ratio.