Issue 27



25 November 2014

Your guide to the latest patents in entertainment technology.

Pepper’s Ghost Illusion: Reflective Surface Tensioning and Cleaning System

Inventors: Curtis Edwards, Thomas LaDuke, Daniel Beaumont
Assignee: Disney Enterprises
Patent No: 8888295
Date of Patent: 18 November 2014

The Pepper’s Ghost illusion has been used to frighten audiences in theatres, haunted houses and scary amusement park rides for hundreds of years – it was first described by camera obscura inventor Giambattista della Porta in 1584, and popularised by John Henry Pepper in 1862.

The basic original design uses a simple piece of plate glass and special lighting to make objects appear and disappear within a scene or room. Generally the systems include a main room or scene that is readily viewed, and a hidden room. Both are identical, except the hidden room contains additional objects or characters such as a ghost. A large piece of glass or a half-silvered mirror is placed between the viewer and the scene at an angle, and the ‘ghost’ becomes visible when the hidden room, or parts of it, are lit, but since only a portion of the light is reflected from the glass, the reflected image superimposed onto the main room appears to float.

This particular invention addresses the need to provide high quality images in extended use or permanent displays that are easy to maintain and install.


The system projects an image stream onto a reflective element with a first surface receiving and reflecting a portion of light associated with the image stream to the viewer, and a second surface opposite the first surface. The apparatus comprises a cleaning assembly including an air supply providing a volume of flowing air, and an ionising mechanism for receiving the flowing air and outputting an ionised airflow. The ionised airflow is directed over the second surface of the reflective element, which is positioned at a non-vertical display angle. An outlet of the cleaning assembly is positioned adjacent an upper edge of the reflective element, and the ionised air flow is output from nozzles as laminar airflow with a flow rate chosen to mitigate dust collection on the upper second surface.

Patently Clear covers the most recent, interesting patents in the industry, granted by the US Patents Office and selected by entertainment tech guru Mike Woods (link below).


Mike Wood Consulting
Full Patent PDF
United States Patent & Trademark Office





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