Dimmable keypad device suitable for multiple faceplate and legend colors
US8102375B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 7, 2008 |
| Grant date | Jan 24, 2012 |
| Priority date | — |
| Expiry date | Nov 24, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2219/039
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A dimmable keypad device (20) includes a plurality of dimming curves stored in memory where each dimming curve corresponds to a combination of background and foreground colors. The dimmable keypad device includes a backlight (203), an ambient light sensor (201) to adjust the illumination of the backlight, key capsules (102) fabricated from substantially transparent plastic and having an opaque paint layer coating their outer surfaces. Key capsule lettering (103) is formed by the removal of a portion of the opaque paint layer and the lettering color, as seen by an observer (42), is formed by backlight illumination of the substantially transparent plastic. The backlight illumination is relatively high under a low ambient lighting condition and relatively low under a high ambient lighting condition when the opaque paint layer is white. The backlight illumination is relatively low under a low ambient lighting condition and relatively high under a high ambient lighting condition when the opaque paint layer is black.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.