A diffuser structure and a manufacturing method thereof are disclosed. A system to be tested may be composed of multiple processors, busses, bus-bridges, shared memories, etc. A layer of polarizer may be laminated onto the surface of the color filter layer. This considerably simplifies the planning of subsequent work and makes it possible to save time and lower costs. Electric power loss can be reduced in a power supply device that uses such a composition circuit in which a switching element and the return diode are connected in reverse parallel.