Field-of-view controlling arrangements

Abstract

A field-of-view controlling arrangement such as a privacy screen includes a single microprism or lenticular sheet having a plurality of sets of parallel surfaces that intersect to form prisms or lenticular structures, and in which field-of-view control is achieved by (i) for sheets made up of parallel “one-dimensional” microprism or lenticular structures having at least two intersecting sets of mutually parallel surfaces, altering at least two sets of the mutually parallel surfaces, and/or portions of the at least two sets of mutually parallel surfaces, by applying a light-attenuating treatment, (ii) for sheets made up of polyhedral lenticular structures having at least three intersecting sets of mutually parallel surfaces, or at least one set of curved surfaces extending in directions transverse to directions in which the field-of-view is to be limited, altering at least one set of the mutually parallel or curved surfaces by applying a light-attenuating treatment, or (iii) for any type of microprism or lenticular sheet, including a diffusing agent in at least a portion of the sheet, and arranging the surfaces of the microprism or lenticular sheet so that light transmitted along selected optical paths is attenuated before exiting the sheet.

What is claimed is:  
     
         1 . A field-of-view controlling arrangement made up of a single microprism or lenticular sheet having at least two sets of parallel planar surfaces that intersect to define portions of prisms or lenticular structures, and additional surfaces not included in said two sets of parallel planar surfaces, 
 wherein at least portions of each said surface in said sets of intersecting parallel planar surfaces are arranged to attenuate light transmitted through the sheet,    wherein said additional surfaces are transparent, and    wherein said light-attenuating portions of each of said surfaces in said sets of intersecting parallel planar surfaces thereby define privacy zones on at least two sides of a field-of-view for images transmitted through the sheet.    
     
     
         2 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein each said surface in said sets of intersecting parallel surfaces is arranged to attenuate light over an entire extent of the surface.  
     
     
         3 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein each said surface in said sets of intersecting parallel surfaces is arranged to attenuate light over only a portion of the surface.  
     
     
         4 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein said intersecting parallel surfaces and said additional surfaces respectively define alternating grooves of a microprism sheet.  
     
     
         5 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein said intersecting parallel surfaces define spaced-apart grooves of a microprism or lenticular sheet, and wherein said additional surfaces extend between said grooves.  
     
     
         6 . A field-of-view controlling arrangement as claimed in  claim 5 , wherein said additional surfaces are planar surfaces extending between said grooves.  
     
     
         7 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein said additional surfaces define lenticular structures extending between said grooves.  
     
     
         8 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein said intersecting parallel surfaces and said additional surfaces respectively define alternating grooves on opposite sides of a microprism sheet.  
     
     
         9 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein said intersecting parallel surfaces define spaced-apart grooves on opposite sides of a microprism or lenticular sheet, and wherein said additional surfaces extend between said grooves.  
     
     
         10 . A field-of-view controlling arrangement as claimed in  claim 1 , wherein said intersecting parallel surfaces include surfaces treated by processes selected from the group consisting of coating processes, delustering, chemical or laser etching, casting, and differential polishing of previously roughened surfaces.  
     
     
         11 . A field-of-view controlling arrangement made up of a single lenticular sheet made up of polyhedral lenticular structures having at least two sets of parallel planar surfaces that intersect to define portions of the lenticular structures, and additional surfaces not included in said two sets of parallel planar surfaces, 
 wherein at least portions of each said surface in said sets of intersecting parallel planar surfaces are arranged to attenuate light transmitted through the sheet,    wherein said additional surfaces are transparent, and    wherein said light-attenuating portions of said at least one if said surfaces in said sets of intersecting parallel planar surfaces thereby defines a privacy zone for images transmitted through the sheet.    
     
     
         12 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein each said surface in said sets of intersecting parallel surfaces is arranged to attenuate light over an entire extent of the surface.  
     
     
         13 . A field-of-view controlling arrangement as claimed in  claim 11  wherein said lenticular structures are truncated tetrahedral structures arranged in staggered rows.  
     
     
         14 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein said lenticular structures are truncated tetrahedral structures arranged in a grid pattern.  
     
     
         15 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein said lenticular structures are tetrahedral structures arranged in staggered rows.  
     
     
         16 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein said lenticular structures are tetrahedral structures arranged in a grid pattern.  
     
     
         17 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein said lenticular structures are truncated hexahedral structures arranged in a honeycomb pattern.  
     
     
         18 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein said lenticular structures are truncated hexahedral structures arranged in a honeycomb pattern.  
     
     
         19 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein said lenticular structures are hexahedral structures arranged in a honeycomb pattern.  
     
     
         20 . A field-of-view controlling arrangement as claimed in  claim 11 , wherein said intersecting parallel surfaces include surfaces treated by processes selected from the group consisting of coating processes, delustering, chemical or laser etching, casting and differential polishing of previously roughened surfaces.  
     
     
         21 . A field-of-view controlling arrangement made up of a single lenticular sheet made up of frustoconical lenticular structures having a curved surface and additional surfaces not included in a set of said curved surfaces, 
 wherein at least portions of each said curved surface in said set of curved surfaces s arranged to attenuate light transmitted through the sheet,    wherein said additional surfaces are transparent, and    wherein said light-attenuating portions of said curved surfaces thereby define a 360° privacy zone for images transmitted through the sheet.    
     
     
         22 . A field-of-view controlling arrangement as claimed in  claim 21 , wherein said curved surface is treated by processes selected from the group consisting of coating processes, delustering, chemical or laser etching, casting, and differential polishing of previously roughened surfaces.  
     
     
         23 . A field-of-view controlling arrangement, comprising: 
 a microprism or lenticular sheet including a diffusing agent in at least a portion of the sheet, and surfaces arranged so that light transmitted through the sheet along selected optical paths is attenuated before exiting the sheet through a first set of surfaces while light transmitted along other optical paths is relatively unattenuated before exiting the sheet through a second set of surfaces oriented at a nonzero angle relative to each of the surfaces in the first set of surfaces, thereby achieving a field-of-view controlling arrangement that restricts viewing of an image from more than one side of the potential field-of-view.    
     
     
         24 . A field-of-view controlling arrangement as claimed in  claim 23 , wherein said bulk diffuser is distributed throughout said sheet.  
     
     
         25 . A field-of-view controlling arrangement as claimed in  claim 23 , wherein said bulk diffuser is concentrated on a light entrance side of said sheet.  
     
     
         26 . A field-of-view controlling arrangement as claimed in  claim 23 , wherein surfaces in said first set of surfaces define spaced-apart grooves of a microprism or lenticular sheet, and wherein said surfaces in said second set of surfaces extend between said grooves.  
     
     
         27 . A field-of-view controlling arrangement as claimed in  claim 26 , wherein surfaces in said second set of surfaces are planar surfaces extending between said grooves.  
     
     
         28 . A field-of-view controlling arrangement as claimed in  claim 26 , wherein surfaces in said second set of surfaces define lenticular structures extending between said grooves.  
     
     
         29 . A field-of-view controlling arrangement as claimed in  claim 33 , wherein surfaces in said first set of surfaces define spaced-apart grooves on opposite sides of a microprism or lenticular sheet, and wherein surfaces in said second set of surfaces extend between said grooves.  
     
     
         30 . A field-of-view controlling arrangement, comprising a transparent sheet having a plurality of spaced apart grooves on at least one side of the sheet, wherein each surface of each of said grooves is arranged to attenuate light to thereby define privacy zones on at least two sides of a field-of-view for images transmitted through the sheet.  
     
     
         31 . A field-of-view controlling arrangement as claimed in  claim 30 , wherein said transparent surfaces extending between said grooves are planar.  
     
     
         32 . A field-of-view controlling arrangement as claimed in  claim 30 , wherein said transparent surfaces extending between said grooves define lenticular structures.  
     
     
         33 . A field-of-view controlling arrangement suitable for use as a window covering, comprising: 
 a microprism or lenticular sheet including surfaces arranged so that light transmitted through the sheet along selected optical paths is attenuated before exiting the sheet through a first set of surfaces while light transmitted along other optical paths is relatively unattenuated before exiting the sheet through a second set of surfaces oriented at a nonzero angle relative to each of the surfaces in first set of surfaces,    wherein sad second set of surfaces is arranged to expand a scene visible through the window.