Single plane optical membrane switch and keyboard
US4480182A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1982 |
| Grant date | Oct 30, 1984 |
| Priority date | — |
| Expiry date | Mar 16, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/3596
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Photo-optical switch apparatus useful for example in keyboard switches includes a photopolymerized orthogonal matrix of horizontal and vertical intersecting light channels or guides, monolithically formed by exposure to ultraviolet light on a flat planar, plastic substrate. Each intersection has a refractive index higher than either the channel or the adjacent substrate area. A curved tap or light coupler couples the horizontal to the vertical channel of the array. The intersections of the channels are disposed over an array of upstanding projections on a flat mounting substrate with each projection located at a respective intersection of the horizontal and vertical light channel. A light absorbing key pad is arranged adjacent to each intersection to couple light from the channel up into the key pad. A relative loss of light indicates the key being depressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.