Glass Member With Dual-Scale Irregularities for Pen and Finger Touch
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Solution Overview
Problem
Existing touch panel surface members provide inadequate tactile sensations for both input pens and fingertips due to excessive irregularities, leading to rough feel and reduced visibility, while fine irregularities cause excessive friction and deteriorate tactile sensations.
Innovation Solution
A glass member with specific surface irregularities, including first irregularities with arithmetical mean height Sa1 of 2-500 nm and mean width RSm1 of 2-100 μm, and second irregularities with Sa2 of 0.7-50 nm, optimized to balance pen and fingertip sliding, enhancing tactile sensations and visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If large irregularities are formed on the surface to improve pen writing feel, then the feel of writing with an input pen is improved, but the feel of touch with a fingertip becomes rough and visibility deteriorates
Solution Approach 1:
The surface irregularities are segmented into two distinct types: first irregularities with larger amplitude (Sa1: 2-500 nm) that provide tactile feedback for pen input, and second irregularities with smaller amplitude (Sa2: 0.7-50 nm) that maintain smooth fingertip contact and visibility. This segmentation allows each type of irregularity to serve its specific function without interfering with the other.
Solution Approach 2:
Different regions of the surface profile are assigned different qualities through the two types of irregularities. The first irregularities provide localized tactile engagement points for pen tips, while the second irregularities provide a generally smooth background that maintains optical clarity and comfortable fingertip contact. This local differentiation resolves the contradiction between pen writing feel and overall smoothness.
2Illumination intensity
If fine irregularities are formed on the surface to improve visibility by suppressing haze, then visibility is improved, but frictional force increases and tactile sensations deteriorate
Solution Approach 1:
The surface structure is segmented into two irregularity types with different amplitude characteristics. The second irregularities (Sa2: 0.7-50 nm) are responsible for haze suppression and visibility improvement, while the first irregularities (Sa1: 2-500 nm) with larger spacing (RSm1: 2-100 μm) provide the tactile sliding feel. This segmentation allows fine irregularities to improve visibility without causing excessive friction.
Solution Approach 2:
The surface structure functions as a composite of two irregularity types, each contributing different properties. The combination of first irregularities (providing tactile feedback) and second irregularities (providing optical clarity) creates a composite surface structure that achieves both visibility improvement and acceptable tactile sensation, resolving the contradiction between these two properties.
3Illumination intensity
If uniform fine irregularities are formed on the surface, then haze is suppressed and visibility is ensured, but frictional force becomes excessive and tactile sensations deteriorate
Solution Approach 1:
Instead of using uniform fine irregularities, the surface is segmented into two irregularity types: second irregularities (Sa2: 0.7-50 nm) that suppress haze and improve visibility, and first irregularities (Sa1: 2-500 nm with RSm1: 2-100 μm) that provide tactile feedback. This segmentation prevents excessive friction while maintaining visibility.
Solution Approach 2:
The surface structure parameters are changed from a single uniform irregularity type to a dual irregularity type system with different amplitude and spacing parameters. The first irregularities have larger amplitude (Sa1: 2-500 nm) and wider spacing (RSm1: 2-100 μm) to reduce friction and improve tactile sensation, while the second irregularities have smaller amplitude (Sa2: 0.7-50 nm) to suppress haze. This parameter differentiation resolves the contradiction between visibility and tactile sensation.
Data Source
AI summary
Provided are: a glass member that excels in tactile sensation such as the feel of writing and the feel of touch; a glass member laminate; an input device; an input display device; a glass member for exterior use; a housing; a door body; a container; and a method for manufacturing the glass member. In first irregularities, the arithmetic mean height Sa1 is 2-500 nm and the mean width RSm1 of roughness profile elements is 2-100 μm when it is assumed that the cutoff value of a high-pass filter λc1 is 14 μm and the cutoff value of a low-pass filter λs1 is 0.35 μm. In second irregularities, the arithmetical mean height Sa2 in a square region with one side measuring 5 μm is 0.7-50 nm when it is assumed that the cutoff value of a high-pass filter λc2 is 2.5 μm.