Key Device Chassis Rib Reduction for Miniaturization

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Solution Overview

Problem

Conventional key devices face challenges in miniaturization due to the need to clear ribs for strength reduction, which increases costs and compromises the structural integrity of the chassis.

Innovation Solution

A key device design where only one of the vertical or horizontal ribs divides the chassis opening, with keys arranged closely using horizontal ribs and a substrate engagement mechanism to ensure strength and miniaturization, utilizing positioning guides and projections to secure keys and maintain chassis rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If one of the vertical and horizontal ribs dividing the chassis opening is cleared to miniaturize the key device, then the key device size is reduced, but the strength of the chassis is reduced

Engineering Contradiction:

Improvekey device sizeVSAvoidchassis strength

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The chassis opening is divided into multiple key arranging spaces using only one set of ribs (either vertical or horizontal), reducing the total number of ribs while maintaining functional segmentation for key placement

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The rib structure is integrated with the substrate through engagement mechanisms, combining the support function of the rib with the mounting function of the substrate to maintain structural integrity with fewer ribs

Inventive Principle:

Principle #5Merging (Combining)

2Strength

If both vertical and horizontal ribs are used to divide the chassis opening into multiple spaces, then the chassis strength is maintained, but the key device size cannot be miniaturized

Engineering Contradiction:

Improvechassis strengthVSAvoidkey device size

Core Design Contradiction:

StrengthVSVolume of moving object

Solution Approach 1:

One set of ribs (either vertical or horizontal) is extracted from the chassis structure, removing unnecessary structural elements while maintaining sufficient support through the remaining rib and substrate engagement

Inventive Principle:

Principle #2Taking out (Extraction)

3Ease of operation

If keytops with flanges are used in the conventional configuration, then the keys can be retained in the chassis opening, but adhering the keytops onto the base film requires high costs

Engineering Contradiction:

Improvekey retentionVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The flange structure is extracted from the keytop design, eliminating the need for adhesive bonding while maintaining key retention through the modified chassis opening configuration and rib structure

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS8665609B2Key device and electronic equipment

Publication Date: 2014.03.04 CASIO COMPUTER CO LTD

AI summary

A key device includes: a chassis which has an opening divided by one of a vertical rib and a horizontal rib; a plurality of keys which are arranged along the opening; and a substrate which is housed in the chassis, wherein the rib is engaged with the substrate.