Title:
TRANSMISSION SCREEN
Document Type and Number:
WIPO Patent Application WO/2004/083955
Kind Code:
A1
Abstract:
A transmission screen preventing a decrease in contrast due to external light such as indoor lighting. A transmission screen comprising a Fresnel lens sheet having Fresnel lens element formed on its viewer-side surface, and a light-shielding sheet (13) disposed on the viewer side of the Fresnel lens sheet, wherein the above problem is solved by forming light-shielding elements (22) which absorbs those portions of the external light (2) incident on the light-shielding sheet (13) from the viewer side which are totally reflected by the projection-light-source-side surface of the Fresnel lens sheet and which go out to the viewer side. At this time, it is preferable that the light-shielding elements transmit the external light that have transmittingly refracted in the light shielding sheet at an angle Ѳ which satisfies at least the relation Ѳ < 24 + 0.018 x F, where Ѳ is the angle at which the external light is incident on the light-shielding sheet and F is the focal length (mm) of the Fresnel lens elements.
Inventors:
OSAWA FUTOSHI (JP)
HONDA MAKOTO (JP)
HONDA MAKOTO (JP)
Application Number:
PCT/JP2004/003646
Publication Date:
September 30, 2004
Filing Date:
March 18, 2004
Export Citation:
Assignee:
DAINIPPON PRINTING CO LTD (JP)
OSAWA FUTOSHI (JP)
HONDA MAKOTO (JP)
OSAWA FUTOSHI (JP)
HONDA MAKOTO (JP)
International Classes:
G02B3/06; G02B3/08; G02B5/00; G02B5/18; G02B5/22; G03B21/62; G03B21/625; (IPC1-7): G03B21/62; G02B3/06; G02B3/08; G02B5/00
Foreign References:
| JP2002350607A | 2002-12-04 | |||
| JP2003050426A | 2003-02-21 | |||
| JP2000112036A | 2000-04-21 | |||
| JPH11223879A | 1999-08-17 |
Attorney, Agent or Firm:
Yoshitake, Kenji (Room 323 Fuji Bldg., 2-3, Marunouchi 3-chom, Chiyoda-ku Tokyo 05, JP)
Download PDF:
Previous Patent: FLAT SOURCE OF LIGHT FRONT LIGHT AND LIQUID CRYTAL DISPLAY
Next Patent: SILVER HALIDE PHOTOGRAPHIC MATERIAL
Next Patent: SILVER HALIDE PHOTOGRAPHIC MATERIAL