Optical member, light source apparatus, display apparatus, and terminal apparatus

Abstract

A planar light source, Fresnel lens sheet, and louver are disposed in the stated order in a light source apparatus. The Fresnel lens sheet deflects and focuses in one dimension light that has entered from the planar light source. The louver is disposed in the optical path of the light emitted from the Fresnel lens sheet, and the directivity of the light can be increased by restricting the traveling direction of the light to the focal direction of the Fresnel lens sheet. The light utilization ratio can thereby be increased, the directivity of planarly emitted light can be increased, and the brightness can be made uniform at the point of observation.

1 . An optical member having:
 an element for restricting the direction of light rays that restricts the traveling direction of incident light to the direction that is parallel to the optical path of the light, and emits the light; and   a deflecting element for deflecting and emitting light that is incident from the element for restricting the direction of light rays.   
     
     
         2 . The optical member according to  claim 1 , wherein said deflecting element is one in which the light-deflecting direction varies depending on the incident position of light, and focuses said light toward a single externally positioned imaginary straight line. 
     
     
         3 . The optical member according to  claim 1 , wherein said deflecting element is one in which the light-deflecting direction varies depending on the incident position of light, and which focuses said light toward a single externally positioned point. 
     
     
         4 . The optical member according to  claim 1 , wherein said deflecting element has a plurality of triangular-columned prisms which are arrayed in the direction orthogonal to said straight line and in which the ridge lines thereof extend parallel to said straight line; and
 the angle between the side surfaces on the far side from said straight line in said prisms and the plane orthogonal to said optical path increases with an increase in the distance from said straight line.   
     
     
         5 . The optical member according to  claim 2 , wherein said deflecting element has a plurality of triangular-columned prisms which are arrayed in the direction orthogonal to said straight line and in which the ridge lines thereof extend parallel to said straight line; and
 the angle between the side surfaces on the far side from said straight line in said prisms and the plane orthogonal to said optical path increases with an increase in the distance from said straight line.   
     
     
         6 . The optical member according to  claim 3 , wherein said deflecting element has a plurality of triangular-columned prisms which are arrayed in the direction orthogonal to said straight line and in which the ridge lines thereof extend parallel to said straight line; and
 the angle between the side surfaces on the far side from said straight line in said prisms and the plane orthogonal to said optical path increases with an increase in the distance from said straight line.   
     
     
         7 . The optical member according to  claim 1 , wherein said deflecting element has a plurality of prisms that are two-dimensionally arrayed in two directions intersecting said optical path; and
 the angle between the side surfaces on the far side from said point in said prisms and the plane orthogonal to said optical path increases with an increase in the distance from said straight line.   
     
     
         8 . The optical member according to  claim 2 , wherein said deflecting element has a plurality of prisms that are two-dimensionally arrayed in two directions intersecting said optical path; and
 the angle between the side surfaces on the far side from said point in said prisms and the plane orthogonal to said optical path increases with an increase in the distance from said straight line.   
     
     
         9 . The optical member according to  claim 3 , wherein said deflecting element has a plurality of prisms that are two-dimensionally arrayed in two directions intersecting said optical path; and
 the angle between the side surfaces on the far side from said point in said prisms and the plane orthogonal to said optical path increases with an increase in the distance from said straight line.   
     
     
         10 . The optical member according to  claim 1 , wherein said deflecting element is a Fresnel lens. 
     
     
         11 . A light source apparatus, having
 a planar light source for emitting planar light, and   the optical member according to  claim 1  for receiving light emitted from the planar light source.   
     
     
         12 . A light source apparatus, having:
 a light source;   a light-guide plate in which light emitted from the light source is incident on the side surface thereof, and the incident light is planarly emitted from the principal surface thereof; and   an element for restricting the direction of light rays that increases the directivity of said light by causing the traveling direction of light incident from the light-guide plate to be restricted to the principal direction of the light, and emitting the light, wherein   said light-guide plate is one in which the light-emitting direction varies depending on the emitting position of the light.   
     
     
         13 . A light source apparatus, having:
 a light source;   a light-guide plate in which light emitted from the light source is incident on the side surface thereof, and the incident light is planarly emitted from the principal surface thereof;   a reflective plate which is disposed on the side opposite from said principal plane as viewed from the light-guide plate, and whereby light that is incident from said light-guide plate is reflected toward said light-guide plate; and   an element for restricting the direction of light rays that increases the directivity of said light by causing the traveling direction of light incident from the light-guide plate to be restricted to the principal direction of the light, and emitting the light, wherein   said reflective plate is one in which the reflective direction thereof varies depending on the incident position of light.   
     
     
         14 . The light source apparatus according to  claim 11 , having a transparent/scattering switching element that can switch between a transparent state in which light emitted from said element for restricting the direction of light rays is allowed to pass, and a scattering state in which the light is scattered. 
     
     
         15 . The light source apparatus according to  claim 12 , having a transparent/scattering switching element that can switch between a transparent state in which light emitted from said element for restricting the direction of light rays is allowed to pass, and a scattering state in which the light is scattered. 
     
     
         16 . The light source apparatus according to  claim 13 , having a transparent/scattering switching element that can switch between a transparent state in which light emitted from said element for restricting the direction of light rays is allowed to pass, and a scattering state in which the light is scattered. 
     
     
         17 . A display apparatus, having:
 the light source apparatus according to  claim 11 , and   a display panel for adding an image to light by transmitting the light emitted from the light source apparatus.   
     
     
         18 . A display apparatus, having:
 the light source apparatus according to  claim 12 , and   a display panel for adding an image to light by transmitting the light emitted from the light source apparatus.   
     
     
         19 . A display apparatus, having:
 the light source apparatus according to  claim 13 , and   a display panel for adding an image to light by transmitting the light emitted from the light source apparatus.   
     
     
         20 . A terminal apparatus, having the display apparatus according to  claim 17 . 
     
     
         21 . A terminal apparatus, having the display apparatus according to  claim 18 . 
     
     
         22 . A terminal apparatus, having the display apparatus according to  claim 19 . 
     
     
         23 . The terminal apparatus according to  claim 20 , being a television receiver, desktop personal computer, notebook computer, ATM, automatic vending machine, onboard television receiver, PDA, game machine, digital video camera, digital camera, video player, or mobile phone. 
     
     
         24 . The terminal apparatus according to  claim 21 , being a television receiver, desktop personal computer, notebook computer, ATM, automatic vending machine, onboard television receiver, PDA, game machine, digital video camera, digital camera, video player, or mobile phone. 
     
     
         25 . The terminal apparatus according to  claim 22 , being a television receiver, desktop personal computer, notebook computer, ATM, automatic vending machine, onboard television receiver, PDA, game machine, digital video camera, digital camera, video player, or mobile phone.