Photoconductive sensors comprising dibromoanthanthrone (DBAA) were constructed aiming at the use in facsimile and digital copier machines.
Among four types of layer construction investigated, single layer sensor construction of DBAA dispersed in binder polymer gave a relatively high photocurrent(1.2×10^-5 A/10mm² at 5×10⁴ V·cm^-1) as well as a very high photo-to-dark current ratio of 2.0×10⁵, but showed a very poor response speed (rise time and decay time > 2000ms).
By adding styryl amine charge transporting material into the DBAA single layer photosensor, response speed was observed to be improved by a factor of 3 to 4×10³ while photocurrent was diminished only by a factor of 11.
Electrode materials of single layer sensor construction were found to affect the dark current values. The effect of the electrode material was discussed in terms of the work function of the material. The potential barrier height for the injection of electron from the electrode to the DBAA photoconductive layer was found to determine the dark current of the photosensor.
The response speed improvement by the addition of carrier transporting material to the photosensitive DBAA layer was regarded as the result of the hole transport enhancement across the layer.

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Diamond-like Carbon (DLC)thin films were prepared by Pulsed Supersonic Molecular Beam Deposition (PSMBD). Deposited films were diamond-like, having reasonable hardness (more than 3 times harder than Quartz substrate), optical transparency in the infrared (E_opt = 1.6 eV), high electrical resistivity (∼ 10¹² Ω·cm) and chemical inertness (no dissolution in a HF: HNO₃ solution). The Raman spectrum of the film has a broad peak centered around 1520 cm^-1.
DLC thin film with the thickness of 0.1 μm, deposited on OPC drum, was tested using the laser beam printer. No damage was occured after up to 70, 000 printings of A4, vertical format.

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This paper describes about a consideration on the high sensitivity of a rotating-wing type's electrometer, which is influenced by the elecrode structure of rotating sector and the circuit structure of pre-amplifier. The rotating-wing is so fan-shaped that the sensible area is alternated by its rotation to result the periodic trigonal waveform. As the results, so long as the blade numbers of rotating-wing and others are fixed suitably, it is verified that the measuring object space is substituted by the equivalent circuit with a constant electric currentsource.
As a trial to investgate the relationships between the electric field distribution of measurement system and the sensibility of electrometer, conformal mapping is applied to get the reasonable results. Moreover, each input impedance of buffer amplifier is examined, and its validity is confirmed.

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