Diffractive Optical Element for Full-Screen Facial Recognition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices with integrated optical modules, such as those in mobile terminals, face limitations in screen design and increased thickness due to the need for notch areas or punch holes for optical devices, which restricts the flexibility of screen design and increases device thickness.
Innovation Solution
A display device design that incorporates a display panel with a first pixel area and a second pixel area, featuring light transmitting parts, a cover glass with a diffractive optical element, and an optical module under the display panel to separate infrared light into dot beams, allowing for facial recognition without the need for notch areas, thereby enhancing screen design freedom and reducing module thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If optical devices are disposed in notch areas or punch holes on the display panel, then optical functions such as facial recognition are achieved, but screen design freedom is limited and device thickness increases
Solution Approach 1:
The patent merges the optical module with the display panel by disposing the optical module under the display panel and integrating the diffractive optical element with the touch sensor layer or display panel structure. This combination eliminates the need for separate notch areas or punch holes, achieving full-screen display while maintaining optical functionality.
Solution Approach 2:
The patent moves the optical module from the front surface (notch/punch hole locations) to the back surface of the display panel, utilizing the z-dimension (thickness direction) to relocate components. This dimensional shift allows the front surface to be fully utilized for display while the optical functions are achieved through the integrated structure.
2Adaptability or versatility
If optical modules are disposed in notch areas, then optical functions are achieved, but the optical module thickness increases overall device thickness
Solution Approach 1:
The patent nests the diffractive optical element within the existing display panel layers, specifically integrating it with the touch sensor layer or circuit layer. This nesting approach allows the optical functionality to be embedded within the display structure itself, minimizing additional thickness.
Solution Approach 2:
The diffractive optical element is implemented as a thin film or patterned layer integrated into the display panel structure, rather than a bulky three-dimensional optical component. This thin-film approach significantly reduces the thickness contribution of the optical module.
3Illumination intensity
If light transmitting parts are added to the second pixel area, then infrared light transmittance is improved for facial recognition, but light loss through circuit layer and wiring increases
Solution Approach 1:
The patent applies local quality by creating light transmitting parts (light transmitting regions) specifically in the second pixel area where infrared light needs to pass through. These regions have different optical properties (higher transmittance) compared to the first pixel area, allowing selective infrared transmission without compromising overall display performance.
Solution Approach 2:
The diffractive optical element acts as an intermediary that separates and directs infrared light from the light source toward the infrared sensor. It processes the infrared light by separating it into dot beams, ensuring efficient transmission through the circuit layer and wiring to the sensor while minimizing energy loss.
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 enables a full-screen display with improved infrared light transmittance for facial recognition, reducing the optical module's thickness and increasing design flexibility, while minimizing light loss through the circuit layer and wiring.
Implementation Method 1
a diffractive optical element disposed on at least one of the cover glass and the display panel at a position facing the light transmitting part of the second pixel area and configured to separate infrared light from the light source into a plurality of dot beams
Data Source
AI summary
A display device and a mobile terminal including the display device are discussed. The display device can include a display panel including a first pixel area and a second pixel area, a cover glass disposed on a first surface of the display panel in the second pixel area, an optical module disposed under a second surface of the display panel to face the second pixel area and configured to direct infrared light towards a light transmitting part of the second pixel area, and a diffractive optical element disposed on or in at least one of the cover glass and the display panel at a position corresponding to the light transmitting part of the second pixel area. The diffractive optical element can separate the infrared light from the optical module into a plurality of dot beams.