[OPTICAL REVIEW Vol. 21, No. 1 (2014) 90-93]
© 2014 The Japan Society of Applied Physics
Nonuniform Intensity Distribution of the Scattered Light by Moving Diffuser across Projection Lens Pupil and Its Influence in Speckle Reduction
Yasushi TOMITA*, Koji SUZUKI, Tatsuo FUKUI, Hironori TOKITA, and Shigeo KUBOTA
Oxide Corporation, Yokohama 223-0052, Japan
(Received May 28, 2013; Accepted October 1, 2013)
The measurement of the nonuniform intensity distribution of scattered light by a moving diffuser using an integrating sphere, which lowers the effective numerical aperture of the projection lens and affects the lowest speckle contrast, is reported. A comparison of the effective numerical apertures realized by several diffusers revealed that JIS #600 or #800 diffusers are most appropriate for efficient speckle reduction.
Key words: encircled energy distribution, integrating sphere, diffuser, speckle, laser display
*E-mail address: tomita@opt-oxide.com