Other

Sortex Limited

Ver-tec Security Systems Limited

David Roy Winterbottom

John David Wiltshire

Brendan D Costello

Laurence John Robinson

Satyamoorthy Kabilian

Richard Howard Evans

Improved techniques for using holograms to provide security for documents and the like. A method of providing a tamper-resistant pattern in association with a hologram on a substrate, the method including: preparing a hologram, the hologram being recorded in a photosensitive recording layer carried by a carrier; printing a pattern onto the photosensitive recording layer; and then attaching the hologram to a substrate by adhesive such that the pattern is between the photosensitive recording layer and the substrate to provide a tamper-resistant pattern in association with the hologram.

Security holograms

A holographic recording system () includes a transparent or semi-transparent holographic recording medium (), a source of coherent optical radiation (), and an optical system (). The recording medium has a first side () presented toward the radiation source, a second side () opposite to the first side and presented toward the optical system, and a recording volume () between the two sides. The radiation source is arranged to project incident optical radiation () onto the first side and through the recording volume towards the optical system, which is arranged to redirect () the optical radiation back onto the second side and into the recording volume so that the incident and redirected radiation intersect within the recording volume at an obtuse angle () to create an interference pattern () from which a holographic recording may be made.

Apparatus and method for producing a hologram

An optical system is disclosed for use in sorting apparatus to monitor light at a viewing station thereof to generate signals indicative of the optical properties of selected items in the product stream being sorted. In the system light received from a single line at the viewing station is split into discrete beams, which are filtered into different wavelength ranges to determine the category of the respective product items. The beams are directed onto a slit through which the light beams must pass on their way to respective lines of light sensors.

Optical systems for use in sorting apparatus

Pattern scanning device

Growing community of inventors

Colchester, United Kingdom

David Roy Winterbottom