Lamp flashing circuit for line generating photoexposure device
US4170745A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1977 |
| Grant date | Oct 9, 1979 |
| Priority date | — |
| Expiry date | Dec 27, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit is disclosed for flashing a flash lamp in a photoexposure device which exposes lines on a photosensitive surface by projecting onto the surface a repetitive series of light spots the locus of which is moved relative to the surface so that the individual light spots partially overlap one another as a chain to synthesize the desired line. During each flash cycle, started by a cycle initiate pulse from an associated control circuit, conduction through the lamp is initiated by a high voltage pulse produced by the discharge of a triggering capacitor, through a high voltage pulse generating circuit, and conduction is thereafter continued by the discharge of a firing capacitor which supplies power at a lower voltage to the lamp. To optimize the maximum rate at which the lamp may be flashed the circuit operates, during each flash cycle, to trigger discharge of the capacitors immediately, or almost immediately, upon their reaching their desired charge. The flashing circuit also automatically compensates for changes in the voltage level at which the flash lamp extinguishes in each flash cycle, thereby maintaining the amount of light produced per flash relatively constant despite su…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.