Apparatus and method for recording holographic images of human subjects
US4474421A · kind A · utility
Inventor
Key dates
| Filing date | Dec 3, 1981 |
| Grant date | Oct 2, 1984 |
| Priority date | — |
| Expiry date | Dec 3, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2210/54
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Safety mechanisms for use in recording holographic images of human subjects are disclosed for preventing a human subject from exposure to the reference beam and the object beam. The safety mechanisms comprise an array of light generating elements, and associated light sensing elements such as photocells arranged along the periphery of the reference beam path. When a subject blocks the reference beam path, the subject will also block sensing light from reaching a photocell, which will prevent the reference beam from traversing its normal path, preferably by disabling the energization circuit of the laser. Another embodiment of a safety mechanism comprises a protective housing which encloses the reference beam path. A safety mechanism is also disclosed for disabling the laser in response to the absence of ground glass screen diffuser in the path of the object beam. A method is also disclosed for recording lifelike images of human subjects comprising the steps of illuminating the subject with a white light source for a predetermined time period, extinguishing the white light source, opening the holographic recording material shutter, activating a pulse laser to generate an object and …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.