Plasma-coupled bipolar linear image sensor

A new bipolar 1728-bit linear image sensor is described. Combining the plasma-coupled device (PCD) shift registers and a photodiode array, a simple structure and unique operation are realized. In contrast to other MOS or CCD imaging devices, some remarkable characteristics and performance were obtained. High output power, more than 1 mW, and high sensitivity of 2.26 × 10
⁸
µA/µJ (at 6000 Å) were measured. Spectra response is observed from 0.45 µm to 0.95 µm, and lineaxity is about unity. Large
S/N
ratio, more than 46 dB, is easily attained. Inherent thermal noise, induced spike noise, and transfer noise axe less than in other conventional imaging devices. Only a single power supply of less than +5 V is necessary. A wide scanning clock frequency range from dc to 3 MHz can be used with a power dissipation of 70 mW being obtained. The above features are discussed in terms of a theory based on the low impedance nature of the bipolar sensing circuit.