Resources Contact Us Home
Projection optical apparatus

Image Number 5 for United States Patent #6798583.

The invention provides a small-sized projection optical apparatus which uses a decentered prism as a projection optical system and in which some contrivances are provided to how to introduce illumination light into a reflection type display device. The projection optical apparatus comprises a reflection type display device 1, a projection optical system 2 for providing projection of an image displayed thereon and an illumination light source for illuminating a display surface. The projection optical system 2 comprises a catadioptric optical element 10 having two rotationally asymmetric curved reflecting surfaces 12, 13 having positive power. The illumination light source is located such that both a light ray leaving the display surface and arriving at a projection display screen and a light ray leaving the illumination light source and arriving at the display surface are reflected at the first and second reflecting surfaces as counted from the display surface side of the catadioptric optical element 10, and that the axis of illumination light 6 incident on the catadioptric optical element 10 is not included in a plane that passes through the axis of projection light 7 leaving the catadioptric optical element 10 and the center of the display surface.

  Recently Added Patents
Storage apparatus and method including page discard processing for primary and secondary volumes configured as a copy pair
Patient programmer with automated MRI compatibility verification for active implantable medical device
Method and system for video parameter analysis and transmission
Crowd formation based on wireless context information
Magnetic circuit and speaker using same
Liquid dispensing apparatus
Forming agent for gate insulating film of thin film transistor
  Randomly Featured Patents
High temperature resistant vitreous inorganic fiber
Process for preparing polycarbonates using pyrrole catalysts
Starter system for an internal combustion engine and a solenoid usable in the starter system
Quench chamber structure for a down flow high pressure gasifier
Use of aryl-substituted pyrimidines as insecticidal and acaricidal agents
Powdery foaming agent
Modulo-2-adder for the logic-linking of three input signals
Chip operating conditions compensated clock generation
Thermal distortion compensation for laser mirrors
Storage-stable accelerator solution