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Applied Optics

Applied Optics


  • Editor: Joseph N. Mait
  • Vol. 52, Iss. 34 — Dec. 1, 2013
  • pp: 8347–8354

High contrast ratio prism design in a mini projector

Jui-Wen Pan and Hsiang-Hua Wang  »View Author Affiliations

Applied Optics, Vol. 52, Issue 34, pp. 8347-8354 (2013)

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In this paper, we present a novel prism with the ability to enhance the contrast ratio and maintain the optical efficiency in a digital light processing projection system. The working theorem for the novel prism is derived as well. In this novel prism design, the ghost ray is directed away from the projection lens by a total internal reflection surface. Since the ghost ray does not even enter the projection lens, the contrast ratio enhancement is more effective than that achieved by an asymmetrical stop. Compared with the conventional method, the full-on/full-off contrast ratio is increased from 9211 to 463471 and the American National Standards Institute contrast ratio is increased from 1771 to 2951. The imaging system efficiency can maintain at 79.8% under the contrast ratio enhancement process. Ghost ray analysis for the novel prism explains the contrast enhancement well.

© 2013 Optical Society of America

OCIS Codes
(230.3670) Optical devices : Light-emitting diodes
(230.5480) Optical devices : Prisms
(330.1800) Vision, color, and visual optics : Vision - contrast sensitivity
(110.2945) Imaging systems : Illumination design

ToC Category:
Optical Devices

Original Manuscript: August 22, 2013
Revised Manuscript: October 29, 2013
Manuscript Accepted: October 29, 2013
Published: November 25, 2013

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Vol. 9, Iss. 2 Virtual Journal for Biomedical Optics

Jui-Wen Pan and Hsiang-Hua Wang, "High contrast ratio prism design in a mini projector," Appl. Opt. 52, 8347-8354 (2013)

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