Optical Module for Touch Detection and Display Illumination
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Solution Overview
Problem
As electronic devices increase in size, the time constant of touch panels increases, leading to lower touch detection accuracy and response speed, and existing display technologies face challenges in power consumption and visibility under varying light conditions.
Innovation Solution
An optical module comprising a light-emitting element with fluorescent substances and a light-emitting diode, an optical filter, and a light-receiving element is integrated into an electronic device, allowing for efficient light management and touch detection, enabling power-saving and improved visibility through reflective and transmissive liquid crystal display technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the electronic device increases in size, then the display area and functionality are improved, but the time constant of the touch panel increases leading to lower touch detection accuracy and response speed
Solution Approach 1:
The patent replaces the conventional electrical touch detection system with an optical detection system. Instead of using electrical signals that are affected by wiring resistance and parasitic capacitance in large devices, the invention uses light emission and detection to sense touch positions, eliminating the electrical time constant problem while maintaining high detection accuracy across large display areas.
Solution Approach 2:
The patent integrates multiple functions into the display system: the display panel serves both as the visual output interface and as the touch sensing interface. The same display structure that presents information to users also detects their touch inputs through optical means, eliminating the need for separate electrical touch sensor systems and their associated wiring constraints.
2Illumination intensity
If a backlight unit is used in a transmissive liquid crystal display, then favorable display performance is achieved, but power consumption increases
Solution Approach 1:
The patent employs pulse-width modulation (PWM) to control the backlight, switching it on and off at high frequency with variable duty cycles. This periodic operation allows the display to achieve different brightness levels while maintaining energy efficiency, as the backlight operates at full intensity only when needed and remains off during refresh periods or low-brightness conditions.
Solution Approach 2:
The patent dynamically adjusts backlight brightness parameters based on ambient light conditions detected by sensors and the current display content requirements. By changing the illumination intensity parameter adaptively rather than maintaining constant high brightness, the system achieves favorable display performance only when necessary while reducing overall power consumption.
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
The solution enhances touch detection accuracy and reduces power consumption by utilizing the optical module for both touch sensing and display illumination, ensuring effective operation across different light environments.
Implementation Method 1
a light-emitting element with fluorescent substances and a light-emitting diode
Implementation Method 2
The plurality of fluorescent substances emit second light by being excited by the first light
Implementation Method 3
The first optical filter has a function of forming third light having a wavelength range longer than 680 nm from the second light
Implementation Method 4
The first light-receiving element has a function of detecting the third light. The first light-receiving element has a function of a sensor detecting the existence of a shielding object on a light path
Data Source
AI summary
An electronic device using a novel optical module is provided.The optical module includes a first light-emitting element, an optical conversion element, and a first light-receiving element. The first light-emitting element includes a plurality of fluorescent substances and a light-emitting diode. The optical conversion element includes a first optical filter. The light-emitting diode emits first light, and the fluorescent substances can emit second light by being excited by the first light. The first optical filter can form third light having a wavelength range longer than 680 nm from the second light. The first light-receiving element has the function of detecting the third light, and the first light-receiving element functions as a sensor detecting the existence of a shielding object on a light path connecting the first light-emitting element and the first light-receiving element. Furthermore, the second light formed by the optical module can function as a light source of the display device.