Input Device Light Guide Reduces Thickness and Leakage
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Solution Overview
Problem
Conventional input devices suffer from light leakage, resulting in insufficient brightness for desired patterns and are thicker due to LED placement on the outer case, making them unsuitable for thin applications.
Innovation Solution
An input device design featuring a light source and guide integrated between two sheets, where the light source is mounted on one sheet and a touch sensor electrode is positioned differently, with a light guide directing light through the body to a design portion, reducing thickness and enhancing brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If LEDs are disposed on the outer case side to illuminate the display, then the display can be lightened up, but the device thickness increases and light leakage occurs
Solution Approach 1:
The patent transitions from placing LEDs on the outer case surface to embedding them within the body thickness direction. The light source is positioned between the first and second sheets, utilizing the internal three-dimensional space to achieve illumination without increasing external device thickness.
Solution Approach 2:
The light source is nested within the body structure, specifically positioned between the first sheet and second sheet. This nesting approach allows the illumination system to be integrated within the existing device layers, eliminating the need for external LED placement that would increase thickness.
2Illumination intensity
If LEDs are disposed on the outer case side, then the display can be illuminated, but light leakage occurs resulting in insufficient brightness for desired patterns
Solution Approach 1:
The patent extracts the light source from the outer case surface and relocates it to an internal position between the sheets. This separation removes the harmful light leakage effect while preserving the useful illumination function, as the light is now contained within the device structure and directed precisely to the display.
Solution Approach 2:
The body structure acts as an intermediary between the light source and the display. By positioning the light source within the body and using the body's internal structure to guide and contain the light, the system achieves precise light delivery to the display while preventing light leakage to surrounding areas.
3Length of stationary object
If the device is made thinner for thin applications, then it becomes suitable for thin surfaces, but conventional LED placement on outer case is no longer feasible
Solution Approach 1:
The patent resolves the manufacturing feasibility issue by moving LED placement from the two-dimensional outer case surface to the third-dimensional internal space between sheets. This dimensional transition allows thin device construction while maintaining LED integration, as the light source is embedded within the device thickness rather than adding to it.
Solution Approach 2:
The light source is nested within the body structure between the first and second sheets, making it suitable for thin device applications. This nesting approach integrates the LED into the device's internal architecture, allowing thin external profiles while maintaining functional illumination capability.
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 allows for high-brightness light emission through the design portion, reducing the device's thickness and enabling uniform, flat installation on thin surfaces, such as storage box covers, while minimizing light leakage.
Implementation Method 1
a guide disposed in a light path from the light source to the design portion, the guide guiding light transmitting through an inside of the body toward the design portion
Data Source
AI summary
An input device includes: a light source that emits light; a first sheet including a design portion; a second sheet having a conductive pattern on which the light source is mounted and in which a touch sensor electrode is disposed in a position different from the light source; a body that is sandwiched between the first sheet and the second sheet to be integral therewith, and transmits the light emitted by the light source; and a guide disposed in a light path from the light source to the design portion, the guide guiding light transmitting through an inside of the body toward the design portion and being distinguished from the body. The light source and the light guide are disposed along a surface of the second sheet on a side facing the body. The body is integral with the light source and the light guide and encapsulates them.