Display with variably transmissive element

Abstract

A display includes a scanning beam display portion and an optical lelement. The scanning beam display portion is responsive to an image signal to present a first image. The optical element has a transmissiveness which varies as a function of ambient light. The first image presented by the scanning beam display portion is visible through the optical element.

What is claimed is:  
     
         1 . A display comprising: 
 a scanning beam display portion responsive to an image signal to present a first image; and    an optical element having a varying transmissiveness and oriented such that the first image presented by the scanning beam display portion is visible through said optical element.    
     
     
         2 . A display according to  claim 1 , in which the optical element varies transmissiveness as a function of ambient light.  
     
     
         3 . A display according to  claim 1 , in which the optical element is a passively variable light transmissive element.  
     
     
         4 . A display according to  claim 3 , in which the passively variable light transmissive element comprises a photochromic material that is sensitive to light to change light transmissiveness as a function of ambient light.  
     
     
         5 . A display according to  claim 1  having an optical output configured for alignment to a viewer's eye.  
     
     
         6 . A display according to  claim 1 , in which said optical element is an actively variable light transmissive element, and further comprising a photosensor which detects ambient light, the transmissive element actively varying transmissiveness based at least in part on the ambient light detected by the photosensor.  
     
     
         7 . A display according to  claim 6 , in which the actively variable light transmissive element comprises a liquid crystal material.  
     
     
         8 . A display according to  claim 6 , in which said transmissive element controls an amount of light presented by the scanning beam display portion which passes through said transmissive leement in response to an photosensor output signal of said photosensor.  
     
     
         9 . A display system comprising: 
 means for generating an image in response to an image signal;    optical means for varying transmissiveness as a function of ambient light, wherein the generated image is emitted from the generating means through the optical element.    
     
     
         10 . A display system according to  claim 9 , in which the optical means comprises a passively variable transmissive optical element light which changes transmissiveness as a function of ambient light.  
     
     
         11 . A display system according to  claim 9 , in which the optical means comprises an actively variable transmissive optical element light which receives a control signal to actively vary the transmissiveness of the optical element.  
     
     
         12 . A display system according to  claim 11 , further comprising a means for sensing ambient light, the sensing means generating the control signal.  
     
     
         13 . A display system according to  claim 11 , in which the optical means comprises a liquid crystal device.  
     
     
         14 . A method of display, comprising: 
 generating an image in response to an image signal;    varying transmissiveness of an optical material as a function of ambient light, wherein the generated image is visible through the optical material.    
     
     
         15 . A display method according to  claim 14 , further comprising: 
 detecting ambient light with a photodetector, wherein the optical material has a transmissiveness which varies actively in response to the detected ambient light.    
     
     
         16 . A display method according to  claim 14 , wherein the optical material is a liquid crystal material and wherein the liquid crystal material is responsive to an output of the photodetector corresponding to the sensed ambient light.