Infrared flash unit
US4866285A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1988 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Jun 20, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2215/0517
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An infrared flash unit, for use with camera employing infrared film, is mounted in a housing having a base configured to fit on the normal flash unit attachment of a standard camera. The housing has a front panel with an array of eight individual reflectors, each having an infrared light emitting diode or laser diode in it. A power supply is connected through a pulse driver circuit to the diodes, each of which are connected in series with a corresponding switch. The diode and switch combination are connected in parallel with one another and in series with the pulse driver circuit. Different combinations of diodes are selected for operation in accordance with the shutter speed and range of the camera. The pulse driver circuit supplies energizing pulses to the selected diodes at a repetition rate and duty cycle selected to match the primary infrared wave length of the diodes and the film used in the camera to reduce fogging due to background infrared light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.