| 摘要 |
PURPOSE: A charge coupled device is provided so that a manufacturing cost of a CCD camera can be reduced by constructing a circuit within a device, not the outside. CONSTITUTION: In an OFD(OverFlow Drain) circuit, a substrate bias(Vsub) is set by using light sensors(41a,41b,41c,41d) each having different sizes. The light sensors(41a,41b,41c,41d) increase those surface areas for receiving light with double(S,2S,3S,4S). Depletion type MOS transistors(M1,M2,M3,M4) are selectively turned on/off according to the amount of charge outputted from the light sensors(41a,41b,41c,41d) connected in series. Poly resistors are connected serially between a power voltage terminal and a ground voltage terminal, and the depletion type MOS transistors(M1,M2,M3,M4) are coupled to respective connection nodes between the adjacent poly resistors. The poly resistors set the substrate bias(Vsub) outputted by turning off the transistors.
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