Display apparatus, display method, goggle-type head-mounted display, and vehicle

Abstract

A display apparatus includes a light source which emits a beam including visible light forming an image and infrared rays, and a transmissive deflection unit including a first surface facing the eyes of a user and a second surface which is a rear surface of the first surface. The transmissive deflection unit has transmissive characteristics for transmitting the visible light from the second surface side to the first surface side, deflection characteristics for deflecting, toward the eyes of the user, the visible light projected from the light source to the first surface side, and infrared absorption characteristics for absorbing the infrared rays projected from the light source to the first surface side.

1 . A display apparatus which displays an image on a retina of a user, said display apparatus comprising:
 a light source which emits a beam including a visible light forming the image and an infrared ray; and   a transmissive deflection unit which includes a first surface facing an eye of the user, and a second surface that is a rear surface of said first surface,   wherein said transmissive deflection unit has:
 a transmissive characteristic for transmitting the visible light from a second surface side to a first surface side; 
 a deflection characteristic for deflecting, toward the eye of the user, the visible light projected from said light source to the first surface side; and 
 an infrared absorption characteristic for absorbing the infrared ray projected from said light source to the first surface side. 
   
   
   
       2 . The display apparatus according to  claim 1 , further comprising:
 a scan unit configured to perform two-dimensional scanning on said first surface of said transmissive deflection unit, using the beam emitted from said light source; and   a control unit configured to cause said light source to change an output intensity of the infrared ray according to a position on said first surface onto which the beam is projected for scanning by said scan unit.   
   
   
       3 . The display apparatus according to  claim 2 ,
 wherein said control unit is configured to cause said light source to increase the output intensity of the infrared ray as a position onto which the beam is projected for scanning by said scan unit becomes closer to a central part of said first surface.   
   
   
       4 . The display apparatus according to  claim 2 , further comprising
 a light detecting unit configured to detect a reflected light intensity, on said transmissive deflection unit, of the beam projected for scanning by said scan unit,   wherein said control unit is configured to cause said light source to change the output intensity of the infrared ray according to a change of the reflected light intensity detected by said light detecting unit.   
   
   
       5 . The display apparatus according to  claim 2 , further comprising
 a line-of-sight detecting unit configured to detect a line-of-sight of the user based on a reflected light, on the eye of the user, of the visible beam deflected by said transmissive deflection unit,   wherein said control unit is configured to cause said light source to increase the output intensity of the infrared ray as a position onto which the beam is projected for scanning by said scan unit becomes closer to a position where the line-of-sight of the user detected by said line-of-sight detecting unit and said first surface intersect with each other.   
   
   
       6 . The display apparatus according to  claim 1 ,
 wherein said transmissive deflection unit includes:
 an infrared absorption layer which is disposed on the first surface side, transmits the visible light, and absorbs the infrared ray emitted from said light source; 
 a visible light deflection layer which is disposed on the second surface side, transmits the visible light traveling from the second surface side to the first surface side, and deflects, toward the eye of the user, the visible light emitted from said light source; and 
 a heat insulation layer which is disposed between said infrared absorption layer and said visible light deflection layer, transmits the visible light, and blocks heat propagation between said infrared absorption layer and said visible light deflection layer. 
   
   
   
       7 . The display apparatus according to  claim 6 ,
 wherein said infrared absorption layer has a different infrared absorptance according to a position on said first surface.   
   
   
       8 . The display apparatus according to  claim 7 ,
 wherein said infrared absorption layer has a higher infrared absorptance as a position on said first surface becomes closer to the central part of said first surface.   
   
   
       9 . The display apparatus according to  claim 2 ,
 wherein said scan unit and said transmissive deflection unit are positioned such that the infrared ray specularly reflected by said transmissive deflection unit is projected onto a position that is different from a position of the eye of the user.   
   
   
       10 . The display apparatus according to  claim 1 , further comprising:
 an electric power supply mode switching unit configured to switch between a first electric power supply mode in which an electric power from an external power source is supplied to said light source, and a second electric power supply mode in which an electric power from a battery included in said display apparatus is supplied to said light source; and   a control unit configured to cause said light source to decrease the output intensity of the infrared ray in response to the switching into the second electric power supply mode by said electric power supply mode switching unit.   
   
   
       11 . The display apparatus according to  claim 1 , further comprising
 a control unit configured to make a wavefront shape of the infrared ray emitted from said light source different from a wavefront shape of the visible light, so that a focal position of the infrared ray that is deflected by said transmissive deflection unit toward the eye of the user is a position that is out of the eye of the user.   
   
   
       12 . A display method for displaying an image on a retina of a user via a transmissive deflection unit,
 wherein the transmissive deflection unit includes:
 a first surface facing an eye of the user, and a second surface that is a rear surface of the first surface; 
 a transmissive characteristic for transmitting a visible light from a second surface side to a first surface side; 
 a deflection characteristic for deflecting, toward the eye of the user, the visible light projected from a light source to the first surface side; and 
 an infrared absorption characteristic for absorbing an infrared ray projected from the light source to the first surface side, said display method comprising: 
   emitting a beam including the visible light forming the image and the infrared ray;   performing two-dimensional scanning on the first surface of the transmissive deflection unit, using the beam emitted in the emitting; and   changing an output intensity of the infrared beam in the emitting according to a position on the first surface onto which the beam is projected for scanning in the scanning.   
   
   
       13 . A goggle-type head-mounted display comprising:
 the display apparatus according to  claim 1 ;   a pair of lenses provided in front of the eyes of the user and each having said transmissive deflection unit on a side facing the eyes of the user; and   a pair of temples each having one end connected to corresponding one of said pair of lenses and the other end fixed to a lateral side of a head of the user.   
   
   
       14 . A vehicle comprising:
 the display apparatus according to  claim 1 ; and   a windshield having said transmissive deflection unit.