Electromotive Force Touch Display Without Front Electrodes
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Solution Overview
Problem
Existing touch sensing technologies for display apparatuses face issues such as image quality deterioration, increased bezel thickness, and higher costs due to the need for transparent electrodes, sensor insertion, and external light vulnerability, particularly in capacitive, infrared, and ultrasonic methods.
Innovation Solution
A display apparatus that utilizes an induced electromotive force generated by a user's touch, sensed through a closed loop circuit with a coil and processor, allowing for touch input detection without compromising image quality or design integrity, by positioning sensors at the backside of the display and using a magnetic field to determine touch inputs based on inductance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transparent electrode such as ITO or silver is applied to the front surface of the display for capacitive touch sensing, then touch sensing capability is achieved, but image quality deteriorates due to non-100% transparency and thickness variations
Solution Approach 1:
The patent moves the touch sensing function from the front surface (2D plane) to the back surface of the display, utilizing the third dimension (depth/thickness) to resolve the contradiction. By placing the coil and closed-loop circuit on the back surface, the transparent electrode requirement is eliminated, maintaining front surface transparency and image quality while achieving touch sensing capability through electromagnetic induction.
Solution Approach 2:
The patent replaces the capacitive sensing mechanism (requiring transparent electrodes) with an electromagnetic induction-based sensing mechanism. The coil generates a magnetic field that induces electromotive force in the closed-loop circuit, and touch detection is achieved by sensing changes in this induced electromotive force, eliminating the need for transparent conductive materials on the front surface.
2Reliability
If a sensor is inserted into the bezel of a display for infrared touch sensing, then touch sensing capability is achieved, but bezel thickness and power consumption increase
Solution Approach 1:
The patent merges the touch sensing function with the existing display structure by integrating the coil and closed-loop circuit into the back surface of the display panel itself. This eliminates the need for separate infrared sensors in the bezel, reducing bezel thickness while maintaining touch sensing capability through the electromagnetic induction mechanism.
3Reliability
If a separate structure is added for ultrasonic touch sensing, then touch sensing capability is achieved, but bezel thickness increases
Solution Approach 1:
The patent makes the display panel itself multi-functional by integrating both display and touch sensing capabilities into a single structure. The back surface housing serves dual purposes: structural support and housing for the electromagnetic induction-based touch sensing components, eliminating the need for separate ultrasonic sensing structures and reducing overall bezel thickness.
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 accurate and intuitive touch sensing without deteriorating image quality or increasing bezel thickness, reducing costs by limiting sensor placement to necessary areas and integrating touch functionality into existing LCD structures.
Implementation Method 1
a sensor configured to: generate an electromotive force in a closed loop circuit, which is provided in a layer of the display, and sense a change in the electromotive force
Implementation Method 2
a sensor comprising a coil configured to generate a magnetic field in accordance with an Alternating Current (AC) voltage applied to the coil
Data Source
AI summary
There is provided a display apparatus, which includes a display configured to display a UI including a plurality of items; a sensor configured to generate electromotive force to a closed loop which is included in the display and sense a user's touch based on a change in the electromotive force which is generated in the closed loop; and a processor configured to execute a function which corresponds to an item touched by a user from among the plurality of items based on a size of the change in the electromotive force generated in the closed loop.