Optical Shutter Keypad for Portable Terminals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing keypad assemblies in portable devices face challenges with limited button count, high power consumption, poor outdoor visibility, and limited color expression, making it difficult to effectively input symbols and provide a click feeling.
Innovation Solution
A keypad assembly featuring an optical shutter, a light guide panel, and a symbol pattern layer illuminated by internal and external light, with light sources and extracting patterns to enhance visibility and power efficiency, and incorporate a dome switch for tactile feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LCD or OLED display keypad is used to increase button count and functionality, then the number of input symbols is improved, but the device becomes thick and consumes much power
Solution Approach 1:
The patent uses an electronic paper display that copies the visual appearance of physical buttons and keymaps without requiring the actual mechanical components. The display shows a three-dimensional keymap image that visually replicates the function of physical buttons while consuming minimal power, solving the contradiction between having many input symbols and low power consumption.
Solution Approach 2:
The patent replaces the mechanical LCD/OLED display system with an electronic paper display system. This substitution eliminates the need for continuous power consumption associated with LCD/OLED backlights and processing, while still providing the visual interface needed for multiple input symbols.
2Adaptability or versatility
If LCD or OLED display keypad is used to increase button count and functionality, then the number of input symbols is improved, but the device becomes thick
Solution Approach 1:
The electronic paper display creates a visual copy of the keymap and button structures without requiring the physical depth of mechanical buttons or the thickness of LCD/OLED layers. The display shows a three-dimensional image that appears flat, reducing the overall device thickness while maintaining functionality.
Solution Approach 2:
The patent employs thin-film electronic paper display technology that can be manufactured as a flexible, thin layer. This thin-film approach eliminates the need for thick mechanical button structures and multi-layer LCD/OLED stacks, significantly reducing device thickness while maintaining the ability to display multiple input symbols.
3Adaptability or versatility
If LCD or OLED display keypad is used to increase button count and functionality, then the number of input symbols is improved, but outdoor visibility is poor
Solution Approach 1:
The electronic paper display is designed to change its visual properties based on ambient lighting conditions. The display can adjust its contrast and brightness characteristics to maintain high visibility in outdoor environments, solving the contradiction between displaying multiple symbols and maintaining outdoor visibility.
Solution Approach 2:
The electronic paper display creates a high-contrast visual copy of the keymap that is specifically optimized for outdoor visibility. The display technology enables the keymap to be clearly visible in bright sunlight conditions while still displaying the full range of input symbols.
4Use of energy by stationary object
If electronic paper display keypad is used to reduce thickness and power consumption, then the device becomes thin and light, but color expression is limited
Solution Approach 1:
The electronic paper display technology used in the patent is capable of displaying multiple colors to represent different button types and states. The display can change colors to indicate various functions and press states, providing adequate color expression for a keypad interface while maintaining low power consumption and thin profile.
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 results in a thin, lightweight keypad with improved color reproduction and visibility, reduced power consumption, and the ability to provide a click feeling, enhancing user experience and interface efficiency.
Implementation Method 1
an optical shutter configured to shield or transmit light according to a voltage applied thereto
Implementation Method 2
The coupled light propagates from the first side surface of the light guide panel to the second side surface opposite to the first side surface, the first side surface of the light guide panel referring to the side surface to which the internal light is coupled, and the light coupled to the interior of the light guide panel undergoing total internal reflection.
Implementation Method 3
at least one light extracting pattern configured to extract light propagating into the light guide panel (280) to the outside of the light guide panel (280) to introduce the extracted light into the symbol pattern layer (282)
Data Source
Figure 1
Figure 2A~2C
Figure 3
AI summary
A keypad assembly includes an optical shutter configured to shield or transmit light according to a voltage applied thereto; a light guide panel configured to guide an internal light generated inside of the keypad assembly and coupled to the interior of the light guide panel; and a symbol pattern layer including at least one symbol pattern illuminated by both the internal light irradiated from the light guide panel and an external light from outside of the keypad assembly that has passed through the optical shutter.