Liquid crystal device, driving method thereof, liquid crystal apparatus, and illumination apparatus
US5631665A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 28, 1994 |
| Grant date | May 20, 1997 |
| Priority date | — |
| Expiry date | Jun 28, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/2014
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illumination apparatus includes a liquid crystal device (L) disposed in the optical path of light projected from a light source (P) and a driving circuit (D) connected to the liquid crystal device for applying a special driving voltage to a composite film (1) of the device (L). The applied driving voltage alternately causes the composite film (1) to attain an opaque state and a transparent state. The time periods of the alternating voltage pulses are varied, thereby changing the ratio of the duration of the opaque state to the duration of the transparent state per unit time period, and thus controlling the power of light transmitted through the composite film (1) without undesirably altering the color spectrum of the transmitted light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.