Backlight and liquid crystal display device

Abstract

A side light type backlight includes a light source including a plurality of LEDs, and a light guide plate. One of the end surfaces of the light guide plate is a light incidence surface at which a plurality of R-LEDs, a plurality of G-LEDs and a plurality of B-LEDs are arranged. LEDs satisfy the relationship of: a distribution range of light emitted from G-LEDs<a distribution range of light emitted from R-LEDs, or a distribution range of light emitted from G-LEDs<a distribution range of light emitted from B-LEDs. Also, LEDs are electrically connected to each other.

1 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which a plurality of R-LEDs, a plurality of G-LEDs and a plurality of B-LEDs are arranged, wherein a plurality of G-LEDs are arranged at one of the light incidence surfaces and a plurality of R-LEDs and a plurality of B-LEDs are arranged at the opposing light incidence surface. 
     
     
         2 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which a plurality of R-LEDs, a plurality of G-LEDs and a plurality of B-LEDs are arranged, wherein a plurality of G-LEDs and a plurality of B-LEDs are arranged on one of the light incidence surfaces and a plurality of R-LEDs are arranged on the opposing light incidence surface. 
     
     
         3 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, at least one of opposing end surfaces of the light guide plate being light incidence surface at which a plurality LEDs are arranged, wherein said plurality of LEDs includes a plurality of white LEDs and a plurality of B-LEDs. 
     
     
         4 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, at least one of opposing end surfaces of the light guide plate being a light incidence surface at which a plurality LEDs are arranged, wherein at least two rows of LEDs are arranged in a direction of a thickness of the light guide plate and the LEDs of each row are arranged in a longitudinal direction of the light incidence surface of the light guide plate. 
     
     
         5 . A side-light type backlight as defined in  claim 4 , wherein the LEDs of the lower row are interposed between the LED positions of the upper row in the longitudinal direction of the light incidence surface of the light guide plate. 
     
     
         6 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which and a plurality LEDs are arranged, wherein the LEDs at both ends are arranged in such a fashion that a light emission portion of each of the LEDs opposes an extreme end of the light incidence surface of the light guide plate in a longitudinal direction. 
     
     
         7 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which the plurality of LEDs are arranged, wherein a frame is provided for accommodating the light source and the light guide plate, and a member having an elastic property or a spring property is arranged between the light source and the frame or between an end surface of the light guide plate opposing the light incidence surface in such a fashion as to press the LEDs to the light guide plate. 
     
     
         8 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which the plurality of LEDs are arranged, wherein the plurality of LEDs are mounted to a circuit substrate, and a member having a higher heat conductivity than that of air is interposed between one of mounting surfaces and surfaces other than light outgoing surfaces of the LEDs, and a surface of a housing of the light source or a surface of a frame constituting a backlight unit. 
     
     
         9 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which plurality of LEDs are arranged, wherein the plurality of LEDs are mounted to a circuit substrate, and one of the mounting surfaces and a surfaces other than light outgoing surfaces of the LEDs makes contact with a surface of a housing of the light source or a surface of a frame constituting a backlight unit. 
     
     
         10 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which the plurality of LEDs are arranged, wherein the light guide plate has a taper shape at an end portion thereof on the side of the light incidence surface, and a jig for fixing the LEDs has a taper shape substantially coming into close contact with the taper shape of the light guide plate. 
     
     
         11 . A side-light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which the plurality of LEDs are arranged, wherein the plurality of LEDs are arranged with intervals among them, and a member is interposed between the LED and the LED. 
     
     
         12 . A backlight as defined in  claim 10 , wherein at least a surface of the jig is a white color or a mirror surface. 
     
     
         13 . A side light type backlight comprising a light source including a plurality of LEDs, and a light guide plate, opposing end surfaces of the light guide plate being light incidence surfaces at which the plurality of LEDs are arranged, wherein the LEDs are mounted to a circuit substrate, and light emission surfaces of the LEDs protrude outward from the circuit substrate. 
     
     
         14 . A backlight as defined in  claim 11 , further comprising a jig for fixing the LEDs, wherein at least a surface of the jig is a white color or a mirror surface.