Innovative Touch Key Assembly for Slimmer Mobile Terminals
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Summary
Problems
Conventional mobile terminals with light-emitting diodes (LEDs) for key illumination suffer from increased thickness due to the space required for LEDs and light obstruction by dome switches, leading to higher power consumption from increased LED numbers.
Innovation solutions
A touch key assembly with an optically transmissive cover and light guide system, where a light source positioned below the touch pad provides light to the keys through apertures, reducing the need for multiple LEDs and minimizing thickness by using an optical waveguide and reflection elements to enhance light distribution.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If LEDs are positioned within the gap between pad and circuit board to illuminate key buttons, then key illumination is achieved, but the gap increases the thickness of the mobile terminal
Why choose this principle:
The patent introduces a light guide as an intermediary component that redirects light from the LED to the key button area. The light guide receives light from the LED positioned in the gap and guides it to illuminate the key buttons, allowing the LED to be positioned closer to the circuit board while still achieving effective illumination without increasing terminal thickness
Principle concept:
If LEDs are positioned within the gap between pad and circuit board to illuminate key buttons, then key illumination is achieved, but the gap increases the thickness of the mobile terminal
Why choose this principle:
The patent uses a reflective element positioned at an angle (45 degrees) to redirect light in a different spatial dimension. The LED emits light upward, the reflective element redirects this light horizontally toward the key buttons, changing the light propagation path from vertical to horizontal direction, thereby illuminating keys without requiring increased vertical space
Application Domain
Data Source
AI summary:
A touch key assembly with an optically transmissive cover and light guide system, where a light source positioned below the touch pad provides light to the keys through apertures, reducing the need for multiple LEDs and minimizing thickness by using an optical waveguide and reflection elements to enhance light distribution.
Abstract
A touch key assembly is structured to operate with a cover having at least one touch key, which is defined by an optically transmissive region of the cover. A touch pad is coupled to the cover and is shaped to define at least one aperture which forms a light guide that is associated with the touch key. A light source is positioned relative to the bottom side of the touch pad, and is further positioned relative to the light guide to provide light to the touch key. The assembly may also include an optical waveguide positioned relative to the bottom side of the touch pad, the optical waveguide being structured to transmit light. A reflection element operatively associated with the bottom side of the optical waveguide may be used to enhance refection of the light. The touch key assembly may be implemented in a portable electronic device, such as a mobile terminal or a personal digital assistant (PDA).