| 摘要 |
PURPOSE: To maximize the heated surface area of a mirror and M minimize the used quantity of a silver conductor material by gradually tapering bus bars from power terminals toward free end sections for distributing the desired power density along the length. CONSTITUTION: Electric bus bars 16, 18 are arranged on one side of a base material 14 and connected to two terminals 20, 22. The bus bars 16, 18 are tapered from the power terminals 20, 22 to free ends, the power density along the length of the bus bars 16, 18 is made equal to the average power density of the whole heater area 12 on the base material 14, thus the electric resistance generated by the bus bars 16, 18 with the prescribed size gives the practically same heating effect as that generated by the heater area 12. The whole surface area of a mirror 10 is practically heated without practically accompanying a cooling point, and the required quantity can be reduced. |
