US Patent No: 5,795,047

Number of patents in Portfolio can not be more than 2000

Projection lens and projection display apparatus

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Abstract

A projection lens includes sequentially from a screen side a first lens group which has a negative power, a second lens group which has a weaker power than that of the first lens group, a third lens group which has a positive power, a fourth lens group which has a positive power, and at least one transparent prism, wherein the fourth lens group is placed on the third lens group side of the transparent prism so as to be close to or in contact with the transparent prism. In the projection lens, a back focus of the main lens group is much longer compared with a focal length. A projection display apparatus using this projection lens is composed of one main lens group, three auxiliary lenses, and three polarizer-beam splitters, and a color combining optical system for combining three primary color components of red, green, and blue into one light beam is placed between the main lens group and the auxiliary lens.

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First Claim

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Patent Owner(s)

Patent OwnerAddressTotal Patents
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.OSAKA27275

International Classification(s)

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  • [Patents Count]

Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Miyatake, Yoshito Neyagawa, JP 58 879
Sannohe, Shinya Neyagawa, JP 24 410

Cited Art

Patent Info (Count) # Cites Year
 
HUGHES-JVC TECHNOLOGY CORPORATION (1)
4,191,456 Optical block for high brightness full color video projection system 74 1979
 
INTERDIGITAL TECHNOLOGY CORPORATION (1)
5,224,120 Dynamic capacity allocation CDMA spread spectrum communications 132 1992
 
INTERNATIONAL BUSINESS MACHINES CORPORATION (1)
5,597,222 Optical relay lens system for projection displays 26 1995
 
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. (1)
5,390,048 Projection lens assembly and projection display apparatus 22 1992
 
PANASONIC LIQUID CRYSTAL DISPLAY CO., LTD. (1)
5,404,175 Method for projecting image obtained by using liquid crystal panels semiconductor substrate and display apparatus for realizing the same 46 1992
 
U.S. PHILIPS CORPORATION (1)
5,400,093 Image projection system with autofocusing 41 1993
 
U.S. PRECISION LENS INCORPORATED (1)
5,218,480 Retrofocus wide angle lens 47 1991
 
WESTLAKE LONGVIEW CORPORATION (1)
6,130,293 High clarity polyethylene compositions 6 1998

Patent Citation Ranking

Forward Cites

Patent Info (Count) # Cites Year
 
EASTMAN KODAK COMPANY (5)
6,624,949 Printing apparatus for photosensitive media using dichroic prism in illumination path 11 2002
6,736,514 Imaging apparatus for increased color gamut using dual spatial light modulators 6 2002
6,769,772 Six color display apparatus having increased color gamut 51 2002
6,863,402 Apparatus for displaying a color image from digital data 32 2004
6,857,748 Apparatus for displaying a color image from digital data 10 2004
 
CANON KABUSHIKI KAISHA (2)
7,102,828 Optical element and manufacturing method thereof 2 2001
7,262,920 Optical element and manufacturing method therefor 1 2003
 
3M INNOVATIVE PROPERTIES COMPANY (1)
7,315,418 Polarizing beam splitter assembly having reduced stress 2 2005
 
FUJINON CORPORATION (1)
6,301,058 Wide-angle lens 22 2001
 
JVC KENWOOD CORPORATION (1)
5,907,437 Converging optics for a single light valve full-color projector 23 1997
 
KONINKLIJKE PHILIPS ELECTRONICS N.V. (1)
6,533,422 Projector having optical components immersed in liquid 1 2001
 
MITSUBISHI DENKI KABUSHIKI KAISHA (1)
6,461,001 Illumination apparatus and projection type display apparatus 15 2001
 
MITSUBISHI ELECTRIC CORPORATION (1)
8,139,166 Image projection apparatus and projection optical system 0 2008
 
NIKON CORPORATION (1)
6,429,906 Projection displays with divergent chief rays at beam splitter 12 2000
 
PANASONIC LIQUID CRYSTAL DISPLAY CO., LTD. (1)
6,549,248 System for a compact projection display using reflection type liquid crystal panels 3 2000
 
SANYO ELECTRIC CO., LTD. (1)
8,049,822 Projection type video display 1 2007
 
SEIKO EPSON CORPORATION (1)
6,250,764 Polarization beam splitter, polarization converter, and projector 4 1999