Patent ID: 7566145

Claim:
A direct type illuminating device comprising: a reflector plate; a diffuser plate spaced at an interval from said reflector plate; at least a light source unit providing source light beams and interposed between said reflector plate and said diffuser plate; and at least a lens module surrounding said light source unit and located between said reflector plate and said diffuser plate, an outer curved surface of said lens module having a radius of curvature different from a radius of curvature of an outer curved surface of said light source unit, wherein said outer curved surface of said lens module has a center of curvature which is non-coincident with that of said outer curved surface of said light source unit; wherein said lens module has left and right parts that are symmetrical to each other, and the curvature of said outer curved surface of said lens module is discontinuous at a junction of said left and right parts of said lens module; wherein said lens module has upper and lower parts that are symmetrical to each other, and the curvature of said outer curved surface of said lens module is discontinuous at a junction of said upper and lower parts of said lens module; whereby said source light beams provided by said light source unit are refracted by said lens module to result in change of traveling directions of said source light beams.