Recording apparatus with double frequency driven liquid crystal shutter
US4641156A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 14, 1984 |
| Grant date | Feb 3, 1987 |
| Priority date | — |
| Expiry date | Sep 14, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40025
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In the recording apparatus of this invention, liquid crystal light shutter operates by using the double frequency drive. The double frequency drive utilizes signals of a high frequency f.sub.H and lower frequency f.sub.L. The dielectric anisotropy of liquid crystal matrial becomes positive in the case of the frequency f.sub.L lower than crossover frequency f.sub.C and becomes negative in the case of the frequency f.sub.H higher than the frequency f.sub.C. When the data signal including the signal of the frequency f.sub.L for a final period of a writing cycle Tw, is applied to write selection electrodes and data signal electrodes, liquid crystal light shutter is kept open for the final period of the writing cycle Tw, namely, opening or closing state of the shutter which is caused during a selection period can be eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.