Compressible Capacitive Sensors in Display Stacks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display stacks in devices such as e-readers and smartphones are thick due to the space-consuming sensors used for detecting user inputs, which hinders device miniaturization and durability.
Innovation Solution
Integration of compressible capacitive sensors with optically clear light guides that serve as both compression layers and light guides, reducing the overall thickness by eliminating the need for separate light guides and minimizing material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If traditional separate sensors and light guides are used in display stacks, then user input detection function is achieved, but device thickness increases
Solution Approach 1:
The patent merges the light guide layer and capacitive sensor layer into a single integrated structure. The light guide serves dual functions: guiding light through the display stack and acting as one of the capacitor plates in the sensor. This integration eliminates the need for separate sensor components, directly reducing display stack thickness while maintaining both lighting and touch detection functions.
Solution Approach 2:
The light guide layer is designed to perform multiple functions simultaneously: it guides light from the backlight to the display, provides structural support, and serves as an electrode in the capacitive sensor system. This multi-functionality reduces the overall component count and simplifies the display stack structure, directly addressing the thickness issue.
2Length of moving object
If compressible capacitive sensors are used, then device thickness is reduced, but sensor reliability under compression may be compromised
Solution Approach 1:
The sensor structure is designed to be dynamically adaptable to compression forces. The capacitive sensor layers are configured to maintain proper spacing and electrical connection even when the display stack is compressed during assembly or use. This dynamic design allows the sensor to withstand compression without permanent damage or performance degradation.
Solution Approach 2:
The patent incorporates compliant layers and flexible structures between rigid components to cushion and distribute compression forces before they reach the sensitive capacitive sensor elements. This protective design prevents stress concentration that could damage the sensor, ensuring reliability while enabling the thin, compressible structure.
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 results in thinner devices with improved durability and reduced component count, enabling more compact and efficient user input detection systems.
Implementation Method 1
a light guide layer integrated into the capacitive sensor stack, where the light guide layer is optically clear and compressible
Implementation Method 2
capacitive sensor stack configured to detect a force applied at the display
Data Source
AI summary
Systems, methods, and computer-readable media are disclosed for ambient light sensing for electronic displays. In one embodiment, a device may include a cover layer, a display, and a capacitive sensor stack positioned in between the cover layer and the display. The capacitive sensor stack may include a first sensor optically coupled to the cover layer, a light guide optically coupled to the first sensor, where the light guide is translucent and compressible, and a second sensor optically coupled to the display and to the light guide. The capacitive sensor stack may be configured to detect a force received at the cover film and to compress in response to the force.