Lens, light source unit, backlight apparatus, and display apparatus

Abstract

A lens diffusing light emitted from a light source includes a concave light-incident surface, a light guide portion, and a light-emitting surface. The light-incident surface includes a plane portion opposed to the light source and an optical function portion that is formed on the plane portion and one of scatters and diffuses the light. The light emitted from the light source enters the light-incident surface. The light that has entered the light-incident surface passes through the light guide portion. The light-emitting surface emits the light passed through the light guide portion.

What is claimed is: 
     
         1 . A lens configured to diffuse light emitted from a light source, the lens comprising:
 a concave light-incident surface including a plane portion opposed to the light source and an optical function portion that is formed on the plane portion and scatters and/or diffuses the light, and which at least a portion of the light emitted from the light source enters;   a light guide portion through which the light that has entered the light-incident surface passes; and   a light-emitting surface configured to emit the light that passes through the light guide portion,   wherein the light-emitting surface is a cylindrical surface or a toroidal surface.   
     
     
         2 . The lens according to  claim 1 , wherein the optical function portion is a part that has been subjected to print processing. 
     
     
         3 . The lens according to  claim 2 , wherein the light-emitting surface includes a part opposed to the plane portion that has been subjected to the print processing. 
     
     
         4 . The lens according to  claim 1 , wherein the optical function portion is a part that has been subjected to roughening processing. 
     
     
         5 . The lens according to  claim 4 , wherein the light-emitting surface includes a part opposed to the plane portion, that has been subjected to the roughening processing. 
     
     
         6 . The lens according to  claim 1 , wherein the light-emitting surface includes a part opposed to the plane portion that has been subjected to roughening processing. 
     
     
         7 . The lens according to  claim 1 , further comprising:
 a bottom surface; and   a print processing portion or a roughening processing portion formed on the bottom surface.   
     
     
         8 . The lens according to  claim 1 , wherein the light guide portion comprises a diffusing material for diffusing the light. 
     
     
         9 . The lens according to  claim 1 , further comprising a heat flow path that is formed from the light-incident surface to the light-emitting surface and discharges heat radiated from the light source. 
     
     
         10 . The lens according to  claim 1 , wherein the light source comprises a plurality of light-emitting elements that are arranged in a predetermined direction and emit light by an EL (Electro Luminescence) phenomenon, and wherein the lens is elongated in the predetermined direction. 
     
     
         11 . The lens according to  claim 10 , wherein the lens has light distribution characteristics that are substantially the same in a direction orthogonal to the predetermined direction within a plane on which the plurality of light-emitting elements are arranged. 
     
     
         12 . A light source unit, comprising:
 a light source; and   a lens configured to diffuse light emitted from the light source, the lens comprising:
 a concave light-incident surface including a plane portion opposed to the light source and an optical function portion that is formed on the plane portion and scatters or diffuses the light, and which at least a portion of the light emitted from the light source enters, 
 a light guide portion through which the light that has entered the light-incident surface passes, and 
 a light-emitting surface configured to emit the light that passes through the light guide portion. 
   
     
     
         13 . The light source unit according to  claim 12 , further comprising:
 an optical member that is mounted on the light source and scatters and/or diffuses the light.   
     
     
         14 . The light source unit according to  claim 13 , wherein the light source comprises a light-emitting element to emit light by an EL phenomenon, and wherein the optical member includes a sealing member to seal up the light-emitting element. 
     
     
         15 . The light source unit according to  claim 14 , wherein the optical member contains a diffusing material. 
     
     
         16 . The light source unit according to  claim 14 , further comprising:
 a common substrate, wherein the light-emitting element of the light source is provided plurally, the plurality of light-emitting elements being arranged on the common substrate, and   wherein the sealing member seals each of the plurality of light-emitting elements.   
     
     
         17 . A backlight apparatus, comprising:
 a light source unit comprising a light source; =   a lens to diffuse light emitted from the light source, the lens comprising:
 a concave light-incident surface including a plane portion opposed to the light source and an optical function portion that is formed on the plane portion and scatters and/or diffuses the light, and which at least a portion of the light emitted from the light source enters, 
 a light guide portion through which the light that has entered the light-incident surface passes, and 
 a light-emitting surface configured to emit the light that passes through the light guide portion; and 
   a supporting member to support the light source unit.   
     
     
         18 . A display apparatus, comprising:
 a light source unit including a light source;   a lens to diffuse light emitted from the light source, the lens comprising:
 a concave light-incident surface including a plane portion opposed to the light source and an optical function portion that is formed on the plane portion and scatters and/or diffuses the light, and which the light emitted from the light source enters, 
 a light guide portion through which the light that has entered the light-incident surface passes, and 
 a light-emitting surface configured to emit the light that passes through the light guide portion; 
   a supporting member to support the light source unit; and   a light transmission control panel that includes a plurality of pixels and controls transmission of the light emitted from the lens for each of the plurality of pixels.