Light Guide V-Shaped Slots Uniform Keypad Illumination
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Solution Overview
Problem
Existing light guide systems for illuminating keypads in electronic devices require multiple expensive light sources, leading to increased power dissipation and non-uniform illumination, with manufacturing costs further elevated by integral lens formation.
Innovation Solution
A light guide with a transparent plate design featuring apertures corresponding to keys, receiving holes for light sources, and V-shaped slots that allow for efficient light distribution and reflection, reducing the number of light sources needed and ensuring uniform brightness across the keypad.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple distributed light sources are used to illuminate each key individually, then each key can be illuminated, but the cost increases significantly and power dissipation increases
Solution Approach 1:
The light guide plate is segmented with multiple V-shaped notches that divide and redirect light from a single source to multiple key areas, creating separate illumination zones without requiring multiple light sources
Solution Approach 2:
The light guide plate acts as an intermediary component that receives light from one source and distributes it uniformly across multiple keys through its V-shaped notched structure
2Illumination intensity
If multiple light sources are used to illuminate the keypad, then illumination coverage is improved, but the standby time decreases due to higher power consumption
Solution Approach 1:
The light guide plate is segmented with multiple V-shaped notches that divide and redirect light from a single source to multiple key areas, creating separate illumination zones without requiring multiple light sources
Solution Approach 2:
A single light source performs the function of multiple light sources by using the light guide plate's V-shaped notches to distribute light uniformly across all keys, making the system more efficient and extending standby time
3Illumination intensity
If a conventional light guide with integral lens formation is used, then light can be directed to keys, but the manufacturing cost increases
Solution Approach 1:
The lens function is extracted from the light guide plate body and implemented separately through V-shaped notches that naturally refract and direct light, eliminating the need for integral lens formation and reducing manufacturing complexity
Solution Approach 2:
The V-shaped notches provide a simpler, cheaper manufacturing approach compared to integral lens formation, accepting that the light guide may need replacement but significantly reducing initial manufacturing costs
4Ease of manufacture
If fewer distributed light sources are used with a light guide, then cost is reduced, but the illumination is not uniform as keys adjacent to the light source are brighter
Solution Approach 1:
The V-shaped notches are strategically positioned and oriented to create different light redirection angles for different key areas, ensuring that keys farther from the light source receive adequate illumination while maintaining uniformity across the entire keypad
Solution Approach 2:
The V-shaped notches utilize the third dimension (depth/angle) to redirect light at specific angles, creating uniform illumination distribution across the two-dimensional key surface from a single light source
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 reduces power consumption, prolongs standby time, and achieves uniform illumination by optimizing light reflection within the light guide, while minimizing manufacturing costs through reduced complexity in lens formation.
Implementation Method 1
The slots are defined in a face of the light guide adjacent to the keypad
Data Source
AI summary
A light guide (30) for illuminating a keypad (20) including a plurality of keys (22) includes a plurality of apertures (300) corresponding to the keys, and a plurality of slots (340). The slots are defined in a face of the light guide adjacent to the keypad.