Patent ID: 8651671
Filing Date: 2014-02-18
Classification: G02B,G03B

Abstract:
1. A projection display device which displays an image by projecting the image on a screen, comprising: at least one light source outputting coherent light; a display device forming an image to be displayed on the screen in an area illuminated by a luminous flux from the light source; a first diffusion unit diffusing the luminous flux; a second diffusion unit diffusing the luminous flux; and a luminous flux intensity leveling unit leveling intensity of the luminous flux; wherein: the first diffusion unit is provided in a light source conjugate position in an optical path of an optical system including the light source through the screen; the second diffusion unit is provided in at least one of a display device conjugate position and a vicinity of the position in the optical path of the optical system; at least one of the first diffusion unit and the second diffusion unit fluctuates perpendicularly to an optical axis; the optical system including the light source through the screen comprises: wherein the display device forms an image to be displayed on the screen in the area illuminated by the luminous flux led by the optical system for illumination; the first diffusion unit is provided in the light source conjugate position in the optical path of the optical system for illumination; the second diffusion unit is provided in at least one of the display device conjugate position and the vicinity of the conjugate position in the optical path of the optical system for illumination; the luminous flux intensity leveling unit is provided in the optical system for illumination, a luminous flux incident surface of the luminous flux intensity leveling unit has a conjugate relationship with the light source, a luminous flux emission surface of the luminous flux intensity leveling unit has a conjugate relationship with the display device; the first diffusion unit is provided in a position of the luminous flux incident surface or a vicinity of the position; and the second diffusion unit is provided in a position of the luminous flux emission surface or a vicinity of the position.