Light diffusion plate and method for manufacturing the same

A manufacturing method for manufacturing a light diffusion plate, comprising:

• feeding a base material of a plastic substrate of the light diffusion plate and at least one light color conversion material into a hopper of a foaming extrusion machine;
• performing uniform mixing and foaming processes for the fed materials in an extrusion screw section of the foaming extrusion machine at a general processing temperature suitable for polycarbonate;
• wherein said general processing temperature suitable for polycarbonate is between 220˜270° C.;
• using a T-die head of the foaming extrusion machine to extrude the uniformly mixed and foamed materials from the extrusion screw section into a plate;
• and
• said extruded plate being rolled by a roller module of the foaming extrusion machine and cooled down, and then the rolled and cooled plate being sent out from a discharge outlet of the foaming extrusion machine as the light diffusion plate;
• characterized in that:
• after the materials are uniformly mixed and foamed in the extrusion screw section, a temperature of front stage at an exit end of the T-die head is lowered by 20-30° C. lower than a process temperature of a section of the extrusion screw section just previous to the T-die head, such that a size of micro-bubbles contained in the plastic substrate is condensed and shrunk to a range of 60-400 μm.