Display device

Abstract

A head-mounted camera of the present invention includes the following elements. A first image pickup device includes a first photographing optical system that can change the focal distance and a CCD for converting a subject image formed by the first photographing optical system into an image signal. A see-through image display portion displays a photographic frame indicating the photographic range as a virtual image so that it is superimposed on a subject substantially directly observed by a photographer. A remote controller includes a second operation switch for setting the visual angle of the photographic frame when viewed from the photographer. A controller/recorder includes a first CPU for setting the focal distance of the first photographing optical system so that the visual angle of the photographic frame set by the second operation switch coincides with the field angle of the first image pickup device.

1 . A display device comprising: 
 an optical element for displaying an image containing predetermined information as a virtual image so that the image is superimposed on a subject substantially directly observed by an observer;    projection means for projecting the image that is displayed by the optical element on the optical element;    virtual-image distance adjusting means for adjusting a distance from the optical element to the virtual image that is displayed by the optical element so as to correspond to a distance from the optical element to the subject.    
   
   
       2 . The display device according to  claim 1 , further comprising visual-angle adjusting means for adjusting the visual-angle concerning the virtual image so as to be constant without depending upon the distance from the optical element to the virtual image.  
   
   
       3 . The display device according to  claim 1 , further comprising distance-measurement means for measuring a distance from the optical element to the subject; 
 wherein the virtual-image distance adjusting means adjusts the distance from the optical element to the virtual image based on the distance from the optical element to the subject measured by the distance-measurement means.    
   
   
       4 . The display device according to  claim 1 , wherein the projection means comprises a display element for generating the image containing the predetermined information; and 
 the virtual-image distance adjusting means adjusts the distance from the optical element to the virtual image that is displayed by the optical element by adjusting the distance between the optical element and the display element.    
   
   
       5 . The display device according to  claim 1 , wherein the projection means comprises a display element for generating the image containing the predetermined information and an image-forming optical system for forming the image generated by the display element on an optical path between the display element and the optical element, and 
 the virtual-image distance adjusting means adjusts the distance from the optical element to the virtual image that is displayed by the optical element by adjusting a position at which the image generated by the display element is formed by the image-forming optical system.    
   
   
       6 . The display device according to  claim 2 , wherein the projection means comprises a display element for generating the image containing the predetermined information, and 
 the visual-angle adjusting means adjusts the visual-angle concerning the virtual image so as to be constant by adjusting the size of the image generated on the display element.    
   
   
       7 . A display device comprising: 
 an optical element for displaying an image containing predetermined information as a virtual image so that the image is superimposed on a subject substantially facing an observer;    a projector that projects the image that is displayed by the optical element on the optical element;    virtual-image distance adjuster that adjusts a distance from the optical element to the virtual image that is displayed by the optical element so as to correspond to a distance from the optical element to the subject.    
   
   
       8 . The display device according to  claim 7 , further comprising visual-angle adjuster that adjusts a visual-angle concerning the virtual image so as to be constant without depending upon the distance from the optical element to the virtual image.  
   
   
       9 . The display device according to  claim 7 , further comprising distance measuring devices that measure a distance from the optical element to the subject; 
 wherein the virtual-image distance adjuster adjusts the distance from the optical element to the virtual image based on the distance from the optical element to the subject measured by the distance measuring device.    
   
   
       10 . The display device according to  claim 7 , wherein the projector comprises a display element for generating the image containing the predetermined information; and 
 the virtual-image distance adjuster adjusts the distance from the optical element to the virtual image that is displayed by the optical element by adjusting the distance between the optical element and the display element.    
   
   
       11 . The display device according to  claim 7 , wherein the projector comprises a display element for generating the image containing the predetermined information and an image-forming optical system for forming the image generated by the display element on an optical path between the display element and the optical element, and 
 the virtual-image distance adjuster adjusts the distance from the optical element to the virtual image that is displayed by the optical element by adjusting a position at which the image generated by the display element is formed by the image-forming optical system.    
   
   
       12 . The display device according to  claim 8 , wherein the projector comprises a display element for generating the image containing the predetermined information, and 
 the visual-angle adjuster adjusts the visual-angle concerning the virtual image so as to be constant by adjusting the size of the image generated on the display element.