Back light module having concave-down luminance distribution
OwnerShih-Yuan Kuoinventor
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Abstract
Several optical mechanism designs for making luminance of the outer portion of a back light module to become higher than luminance of the inner portion of the back light module of the direct lighting type are disclosed in accordance with the present invention. The disclosed optical mechanism designs can be cooperated 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 utilization in various scanners or liquid crystal displays.
Claims17
A back light module of direct lighting type comprising:
- a light emitting device for emitting light, wherein an outer portion of the light emitting device with respect to an axis having higher luminous intensity than an inner portion of the light emitting device;
- a diffuser positioned on a side of the light emitting device for diffusing light;
- and
- a reflecting device positioned on another side of the light emitting device for reflecting light emitted from the light emitting device to the diffuser.
A back light module of direct lighting type comprising:
- a light emitting device for emitting light;
- a diffuser positioned on a side of the light emitting device for diffusing light;
- and
- a reflecting device positioned on another side of the light emitting device for reflecting light emitted from the light emitting device to the diffuser;
- wherein the outer portion of the reflecting device has higher reflectivity or larger reflecting area than the inner portion of the reflecting device.
A back light module of direct lighting type comprising:
- a light emitting device for emitting light;
- a diffuser positioned on a side of the light emitting device for diffusing light, wherein the outer portion of the diffuser has higher light transmittance than the inner portion of the diffuser;
- and
- a reflecting device positioned on another side of the light emitting device for reflecting light emitted from the light emitting device to the diffuser.
Dependencies are inferred from the claim text.