Abstract: A color image scanner which includes a plurality of light sources composed of a first light emitting diode for emitting a red light, a second light emitting diode for emitting a yellow light and a fluorescent light source for emitting a blue light, a control circuit for switching the plurality of light sources, sequentially and an image sensor for receiving light reflected from the original, scanned image, wherein a characteristic value of the light emitted from the first light emitting diode is selected so as to have an overlap in wavelength with that of the light emitted from the second light emitting diode, and a characteristic value of the light emitted from the fluorescent light source is selected so as to have an overlap in wavelength with that of the light emitted from the second light emitting diode.

Abstract: A head drive system for printer apparatus for gray scale recording divides digital data representing each pixel into upper and lower groups of bits respectively defining upper bit data and lower bit data. The lower bit data is compared with periodic reference data. On the basis of the comparison, binary data is derived and added to the upper bit data to form output data for controlling a printer head. The invention combines the advantages of density modulation and area modulation and at the same time enables high speed data processing and printing.

Abstract: An improved photosensitive material for electrophotography, said material comprising a mixture of a polyvinylcarbazole or a derivative thereof together with a sensitizing dye consisting of certain alkyl substituted indocyanine derivates, particularly the perchlorates.

Abstract: A method for forming a color image includes a step of spraying three kinds of photoconductive toners with a sensitization wavelength band different from its absorption wavelength band, a step of electrically charging these different toners, a step of exposing these sprayed and electrically charged photoconductive toners to light for selectively removing electrostatic charges, and a step of removing the toners freed of electrostatic charges from the substrate. The magenta color photoconductive toners sensitive to red light, yellow color photoconductive toners sensitive to green light, and the cyan color photoconductive toners sensitive to blue light, are used as aforementioned three kinds of photoconductive colors.

Abstract: An electrostatic printing apparatus of the ion-flow type for printing an image on record paper in response to an information signal includes a corona generator for generating ions; a back electrode over which the paper travels for producing a bias potential to cause the generated ions to flow from the corona generator toward the back electrode onto the recording paper; a control electrode interposed between the corona generator and the back electrode for controlling the flow of ions therebetween and including a plurality of apertures through which the ions are adapted to flow; and a control signal generator for supplying a control signal to the control electrode to cause the latter to control the amount of ion flow through each aperture, in response to the level of the information signal, to a first amount corresponding to an area on the paper which is black, a second amount corresponding to an area on the paper which is white, or at least one other amount corresponding to at least one area on the paper which

Abstract: A stabilized power supply circuit has a stabilized or regulator circuit connected between an input terminal and a first output terminal and a constant voltage element for example, a Zener diode, whose one electrode is connected to the input terminal and whose other electrode is connected to the first output terminal, and a second output terminal is connected to the first-mentioned electrode of the constant voltage element.

Abstract: A novel circuit is provided for controlling an alternating current supplied to a load which includes a variable impedance element in the form of a low emitter concentration transistor which is bidirectional, and which has a high gain. The impedance of the variable impedance element to the flow of current therethrough is substantially the same in either direction of current flow.