Projector having an object detector

Abstract

The invention provides a projector having a light source, a display device to modulate light emitted from the light source, a lens device to project light emitted from said light source via said display device, wherein the lens device has a diaphragm mechanism that is formed having an aperture, an object detector to detect an object between the lens device and the screen, and a diaphragm mechanism drive control to drive the diaphragm mechanism so as to reduce a size of an opening of the aperture of the diaphragm mechanism when the object detector detects an object between the lens device and the screen.

1 . A projector comprising: 
 a light source;    a display device to modulate light emitted from the light source;    a lens device to project light emitted from said light source via said display device, wherein the lens device comprises a diaphragm mechanism that is formed having an aperture;    an object detector to detect an object between the lens device and the screen; and    a diaphragm mechanism drive control to drive the diaphragm mechanism so as to reduce a size of an opening of the aperture of the diaphragm mechanism when the object detector detects an object between the lens device and the screen.    
   
   
       2 . The projector as claimed in  claim 1 , wherein the lens device is arranged telecentric to rays of light emitted from the display device and comprises a diaphragm mechanism having an aperture at such a position that the lens device causes principal rays of light emitted from various locations on the display device to intersect with the optical axis.  
   
   
       3 . The projector as claimed in  claim 2 , wherein the shape of the aperture of the diaphragm mechanism is determined in accordance with contrast characteristics with respect to directions and angles of incidence of light emitted from the display device onto the lens device so as to ensure a sufficiently high contrast.  
   
   
       4 . The projector as claimed in  claim 1 , wherein the display device is comprised of liquid crystal panels.