Reflection type diffuse hologram, hologram for reflection hologram color filters, etc, and reflection type display device using such holograms

Abstract

A method of fabricating a hologram having a pattern made up of pixels in which a photosensitive material for forming a hologram is stacked on either a reflection-type hologram or a transmission type hologram. According to one aspect of the invention, the photosensitive material is stacked on a reflection-type relief hologram and reconstructing illumination light of a given wavelength is struck on the reflection-type relief hologram through the photosensitive material, so that interference fringes produced by interference of the light diffracted from the reflection type relief hologram and the incident light are recorded in the photosensitive material. According to another aspect of the invention, the photosensitive material is stacked on a transmission-type hologram, and reconstructing illumination light of a given wavelength is struck on a side of the transmission type hologram that is not opposite to the volume hologram photosensitive material, so that interference fringes produced by interference of light diffracted from the transmission type hologram and reference light incident on the photosensitive material are recorded in the photosensitive material. According to a third aspect of the invention, the photosensitive material is stacked on a transmission type hologram, and reconstructing illumination light of a given wavelength is struck on a side of the transmission type hologram that is not opposite to the photosensitive material, so that interference fringes produced by interference of light diffracted from the transmission type hologram and zero-order transmitted light are recorded in the photosensitive material, and a reflecting layer is provided on a back side of the photosensitive material.

1 . A reflection type diffuse hologram characterized by reflecting, and diffracting light incident thereon at an angle with respect to a normal direction while it is diffused within a desired angle range.  
   
   
       2 . The reflection type diffuse hologram of  claim 1 , characterized in that an angle of diffusion lies within a range of 10° to 35°.  
   
   
       3 . A reflection type diffuse hologram, characterized by having been formed by allowing scattered light that diffuses within a desired angle range, and parallel light to strike on both surfaces of a volume hologram-recording photosensitive material, and interfere therein.  
   
   
       4 . The reflection type diffuse hologram of any one of  claim 1  to  3 , characterized in that an image has simultaneously been recorded in a reconstructible fashion.  
   
   
       5 . The reflection type diffuse hologram of any one of  claim 1  to  3 , characterized by being located on a backlight side of a liquid crystal display device for diffuse illumination purposes.  
   
   
       6 . A method for fabricating a reflection type diffuse hologram characterized in that a transmission type diffusing plate having a diffusion angle characteristic within a desired angle range is located in close contact with, or in proximity to, a volume hologram-recording photosensitive material, and two light beams are allowed to strike on front and back sides of the combined diffusing plate and photosensitive material for interference recording.  
   
   
       7 . The method for fabricating a reflecting type diffuse hologram according to  claim 6 , characterized in that the transmission type diffusing plate is a diffusing plate of a 20% to 60% haze.  
   
   
       8 . The method for fabricating a reflecting type diffuse hologram according to  claim 6 , characterized in that the transmission type diffusing plate is an array of microlenses.  
   
   
       9 . The method for fabricating a reflecting type diffuse hologram according to  claim 6 , characterized in that the transmission type diffusing plate is a lenticular screen.