Back light module having concave-down luminance distribution
AssigneeLite-On Technology Corporation
InventorShih-Yuan Kuo
Life of this patent
Estimating the term…
Abstract
Several optical mechanism designs for making luminance of the outer portion of a back light module of edge lighting type to become higher than luminance of the inner portion of the back light module are disclosed in accordance with the present invention. The disclosed optical mechanism designs can cooperate with each other to enhance the optical effect of the back light module. Additionally, the back light modules of the present invention are feasible for use in various scanners or liquid crystal displays.
Claims27
A back light module of edge lighting type comprising:
- a light guide plate (LGP) for scattering incident light to a light output surface;
- a diffuser positioned on the light output surface of the light guide plate for diffusing light from the light output surface;
- a reflecting layer positioned on a reflection surface of the light guide plate for reflecting light into the light guide plate;
- and
- a light emitting device for emitting light to at least one side of the light guide plate, wherein the outer portion of the light emitting device along a first axis having higher luminous intensity than the inner portion thereof.
A back light module of edge lighting type comprising:
- a light emitting device for emitting light;
- a light guide plate (LGP) for scattering light from the light emitting device to a light output surface, wherein a plurality of reflection patterns/elements being formed on a reflection surface of the light guide plate so that the outer portion of the light guide plate has higher luminance than the inner portion of the light guide plate;
- a diffuser positioned on the light output surface of the light guide plate for diffusing light from the light output surface;
- and
- a reflecting layer positioned on the reflection surface of the light guide plate for reflecting light into the light guide plate.
A back light module of edge lighting type comprising:
- a light emitting device for emitting light;
- a light guide plate (LGP) for scattering light from the light emitting device to a light output surface;
- a diffuser positioned on the light output surface of the light guide plate for diffusing light from the light output surface, wherein the outer portion of the diffuser has higher light transmittance than the inner portion of the diffuser;
- and
- a reflecting layer positioned on a reflection surface of the light guide plate for reflecting light into the light guide plate.
A back light module of edge lighting type comprising:
- a light guide plate (LGP) for scattering incident light to a light output surface;
- a diffuser positioned on the light output surface of the light guide plate for diffusing light from the light output surface;
- a reflecting layer positioned on a reflection surface of the light guide plate for reflecting light into the light guide plate;
- a light emitting device for emitting light to the light guide plate;
- and
- a reflector positioned on a side of the light emitting device such that the light emitting device being disposed between the reflector and the light guide plate, the reflector for reflecting light from the light emitting device to the light guide plate;
- wherein the outer portion of the reflector has higher reflectivity or larger reflecting area than the inner portion of the reflector.
A back light module of edge lighting type comprising:
- a light guide plate (LGP) for scattering incident light to a light output surface;
- a diffuser positioned on the light output surface of the light guide plate for diffusing light from the light output surface;
- a reflecting layer positioned on a reflection surface of the light guide plate for reflecting light into the light guide plate;
- a light emitting device for emitting light to the light guide plate;
- and
- two reflectors positioned on a side of the light emitting device with each corresponding to one of two ends of the light emitting device such that the light emitting device being disposed between the two reflectors and the light guide plate, the two reflectors for reflecting light emitted from the two ends of the light emitting device to the light guide plate.
Dependencies are inferred from the claim text.