Knurled Keytop Surface for Slip-Resistant Tilt and Press Input

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Solution Overview

Problem

Conventional input apparatuses for electronic devices, such as cameras, face issues with slippage and discomfort during multidirectional tilt and press operations due to smooth operation surfaces, leading to incorrect operations and potential user discomfort.

Innovation Solution

The input apparatus features a keytop with a knurled operation surface having a twill shape and a wall portion, where each vertex is on a spherical surface, enhancing friction and preventing slippage, allowing precise tilt and press operations by optimizing the radius and angle of the surface features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a smooth operation surface is used, then the manufacturing process is simple, but the finger slips during tilt operation causing incorrect input

Engineering Contradiction:
Improveoperation surface manufacturing simplicityVSAvoidinput accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The operation surface is divided into two distinct regions: a smooth pressing region for press operations and a knurled tilted region for tilt operations. Each region has different surface properties optimized for its specific function, resolving the contradiction by providing locally appropriate surface characteristics rather than a uniform surface.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The operation surface is segmented into functionally distinct zones - the pressing region and the tilted region with knurled surface. This segmentation allows each zone to be optimized independently for its specific operation type, preventing slippage during tilt operations while maintaining manufacturing simplicity through modular design.

Inventive Principle:
Principle #1Segmentation

2Reliability

If concave or convex portions are added to the operation surface, then slippage is reduced, but press operation becomes difficult and may hurt the user

Engineering Contradiction:
Improveslip preventionVSAvoidpress operation comfort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The knurled surface pattern is applied only to the tilted region where tilt operations occur, while the pressing region maintains a smooth surface. This localized application of surface treatment provides slip prevention exactly where needed for tilt operations without interfering with press operations, resolving the contradiction between slip prevention and press operation comfort.

Inventive Principle:
Principle #3Local quality

3Reliability

If a knurled surface is applied to the entire operation surface, then slippage is prevented, but the structure becomes more complex

Engineering Contradiction:
Improveslip preventionVSAvoidoperation surface structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The knurled surface pattern is selectively applied only to the tilted region rather than the entire operation surface. This localized approach provides slip prevention where it is most needed for tilt operations while keeping the pressing region simple and smooth, thereby reducing overall structural complexity compared to full-surface knurling.

Inventive Principle:
Principle #3Local quality

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 improves the operability of both tilt and press operations by reducing slippage and discomfort, ensuring accurate and comfortable user input.

Implementation Method 1

a knurled operation surface having a twill shape... enhancing friction and preventing slippage

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4318174A1Input apparatus and electronic apparatus
Publication Date: 2024.02.07 CANON KK
  • EP4318174A1 patent drawingFigure 1
  • EP4318174A1 patent drawingFigure 2
  • EP4318174A1 patent drawingFigure 3~4

AI summary

An input apparatus includes an operation surface having a twill shape and configured to receive input through tilt operation and press operation, and a wall portion formed at an end of the operation surface. Each vertex of the twill shape is located on a spherical surface. The wall portion protrudes from the spherical surface.