	US 7,532,398 B2
	Light pipe and polarized-light source
Minoru Miyatake, Osaka (Japan); and Takafumi Sakuramoto, Osaka (Japan)
Assigned to Nitto Denko Corporation, Osaka (Japan)
Filed on Apr. 28, 2006, as Appl. No. 11/412,996.
Application 11/412996 is a division of application No. 10/872460, filed on Jun. 22, 2004.
Application 10/872460 is a division of application No. 09/569024, filed on May 11, 2000, granted, now 6,952,310, filed on Oct. 08, 2005.
Claims priority of application No. P. 11-131429 (JP), filed on May 12, 1999; application No. P. 11-131430 (JP), filed on May 12, 1999; application No. P. 11-138102 (JP), filed on May 19, 1999; application No. P. 11-166727 (JP), filed on Jun. 14, 1999; application No. P. 11-174368 (JP), filed on Jun. 21, 1999; and application No. P. 11-197083 (JP), filed on Jul. 12, 1999.
Prior Publication US 2007/0014007 A1, Jan. 18, 2007
Int. Cl. G02B 5/30 (2006.01); F21V 7/04 (2006.01)

U.S. Cl. 359—500 [359/599; 362/19; 362/558; 362/619; 362/623]

11 Claims

1. A light pipe comprising:

a laminate having a birefringent light-transmitting resin plate, and a polarized-light scattering plate laminated on at least one surface of said light-transmitting resin plate, said polarized-light scattering plate having fine birefringent domains dispersed therein to exhibit anisotropy in scattering depending on a polarization direction; and

a specular reflection layer provided on a surface of said laminate, such that said specular reflection layer is on a side of said laminate which is opposite said birefringent light-transmitting resin plate,

wherein said polarized-light scattering plate is positioned between said light-transmitting resin plate and said specular reflection layer,

said light-transmitting resin plate and said polarized-light scattering plate do not contact each other, and

a phase difference due to birefringence of the light-transmitting resin plate is 50 nm or more based on an average phase difference in a plane of said light-transmitted resin plate.