Keyboard Light Guide Curved Incident Surface
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing keyboard designs, such as those described in JP-A-06-242729, suffer from insufficient light illumination of keytops due to light leakage from the prism, resulting in reduced visibility, especially in dark environments.
Innovation Solution
A keyboard with a light guide member having a refractive index greater than air, featuring a curved incident surface that increases the surface area to capture more light from the light source, and a guide portion with reflection surfaces that direct light efficiently to the emitting portion, ensuring maximum light is focused on the keytop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a prism is used to guide light from the light source to the keytop, then the keytop is illuminated, but light leaks from places other than the emitting end portion, resulting in insufficient illumination quantity and visibility
Solution Approach 1:
The patent changes the geometric parameters of the light guide member, specifically forming the incident surface as a curved surface that protrudes toward the light source. This increases the surface area of the incident portion, allowing more light to enter the light guide member and be directed to the keytop, thereby improving illumination intensity while maintaining controlled light emission
Solution Approach 2:
The incident surface of the light guide member is designed as a curved surface rather than a flat surface. This curvature allows the surface to protrude toward the light source, increasing the effective incident area and improving light capture efficiency, which resolves the contradiction between achieving sufficient illumination and preventing light leakage
2Quantity of substance
If the surface area of the incident portion is increased to capture more light, then the quantity of light incident from the light source increases, but the device structure becomes more complex
Solution Approach 1:
Instead of increasing the physical size or adding complex structures, the patent employs a curved incident surface that protrudes toward the light source. This geometric modification increases the surface area in a simple, integrated manner, capturing more light without complicating the overall device structure
Solution Approach 2:
The incident surface extends in the radial direction of the axial line, utilizing the third dimension to increase surface area. The curved surface protrudes radially outward toward the light source, effectively capturing more light without increasing the axial length or overall device complexity
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
This configuration enhances the quantity of light illuminating the keytop, improving visibility and allowing the keyboard to be effectively used in dark places without light leakage, thus providing excellent visibility.
Implementation Method 1
since the refractive index of the light guide member is greater than the refractive index of the air, the light which is radiated from the light source and has reached the incident portion is refracted without being reflected on a front surface of the incident portion, and enters the inside of the light guide member from the incident portion
Implementation Method 2
the light incident from an incident end portion of the prism advances while being reflected on the inside of the prism, and then, is emitted toward the keytop from an emitting end portion of the prism
Data Source
Figure 1(a)~1(b)
Figure 2~3
Figure 4
AI summary
An object of the present invention is to improve visibility of a keybutton. In a keyboard in which a keybutton 11 supported by a housing 12 is disposed to oppose an operation detection portion 15 on an axial line X along an operating direction of the keybutton 11, a light source L is provided further on an outer side than the operation detection portion 15 on a substrate 30 when viewed from an axial direction of the axial line X, a light guide member 50 which guides light from the light source L to a keytop 110 of the keybutton 11 is formed of a material having a refractive index which is higher than that of the air and is provided in the housing 12, the light guide member 50 includes an incident portion 51 disposed to oppose the light source L in the axial direction of the axial line X, an emitting portion 53 disposed to oppose the keytop 110 at a position hidden by the keybutton 11 when viewed from the axial direction of the axial line X, and a guide portion 52 which guides the light, from the light source L, incident from the incident portion 51 to the emitting portion 53, and an incident surface 510 which is a surface that opposes the light source L of the incident portion 51 is formed in a shape of a curved surface that protrudes to the light source L side.