Patent ID: 7354179
Filing Date: 2008-04-08
Classification: F21V,F21Y,G02B,G02F

Abstract:
1. A prism set for diffusing light rays, comprising: a first prism having a first incident face and a first refraction face that is adjacent to and that cooperates with said first incident face to define an angle ranging 50° to 70°, and having a third refraction face for the light rays to exit from, wherein the third refraction face is located in a first light path which includes a total reflection on the first refraction face; a second prism having a second incident face that is generally parallel to said first refraction face, and having a second refraction face for the light rays to exit from, wherein the second refraction face is located in a second light path which includes no reflection; and a medium layer sandwiched between said first refraction face and said second incident face, and having a refractive index smaller than that of said first and second prisms.