Abstract: Because the prior art liquid crystal driving control circuit needs shift registers, latch circuits and selectors in a number corresponding to the number of cells in the liquid crystal shutter array, the structure of the circuit inevitably becomes complicated and involves a large number of components to thereby push up the production cost. Since this invention method controls a liquid crystal shutter array with pulse width modulation, image data can be serially converted into the data necessary for switching ON/OFF the driving voltage, and the conversion circuit can be structured with only one system. As this invention method controls opening/closing of the cells with binary pulse width signals in a number corresponding to the number of liquid crystal cells, the structure of the circuit can be simplified and yet efficiency of recording in controlled gradation can be enhanced.

Abstract: A method for driving a twisted nematic type liquid crystal shutter, the liquid crystal shutter having a pair of transparent substrates held opposite to each other; a pair of patterned transparent electrodes each formed on the planes of the transparent substrates and arranged opposite to each other so that the overlapping parts of the patterns form display pixels; a pair of aligning film each formed on the pattern of the transparent electrode and on the plane; a liquid crystal material contained in a space between the transparent substrates; and a pair of transmission type polarizers each arranged on the outside plane of the transparent substrate which is counter to the plane on which the patterned transparent electrode is formed, comprising the steps of: applying an electric voltage to establish static or multiplex driving to the transparent electrodes so as to prevent the transmission of incident light when no image signal is received from an external apparatus; and preventing the application of the electric

Abstract: An image recording device has an optical switch panel disposed nearly or directly in contact with a photosensitive body. The optical switch panel contains many liquid crystal display dot elements between a pair of boundary layers and serves to form on the photosensitive body an image which is displayed on the optical switch panel. The boundary layer on the side of the photosensitive body is significantly thinner than that distal therefrom.

Abstract: Because the prior art liquid crystal driving control circuit needs shift registers, latch circuits and selectors in a number corresponding to the number of cells in the liquid crystal shutter array, the structure of the circuit inevitably becomes complicated and involves a large number of components to thereby push up the production cost. Since this invention method controls a liquid crystal shutter array with pulse width modulation, image data can be serially converted into the data necessary for switching ON/OFF the driving voltage, and the conversion circuit can be structured with only one system. As this invention method controls opening/closing of the cells with binary pulse width signals in a number corresponding to the number of liquid crystal cells, the structure of the circuit can be simplified and yet efficiency of recording in controlled gradation can be enhanced.

Abstract: A developing unit for electrophotography has a magnet roller disposed opposite to its photosensitive drum and a toner sensor disposed near the magnet roller and displaced from the position of one of the poles of the magnet roller by 5.degree.-15.degree. in the direction of the photosensitive drum.

Abstract: A documenting reading apparatus is comprised of a cylindrically shaped color filter with three filter elements having different colors. Both a light source and a cylindrical lens are disposed inside this cylindrical filter.

Abstract: An automatic exposure adjusting device for use in a variable copying magnification type copying apparatus, which controls quantity of light of a light source by detecting photographic density of an original document by the use of a photo detector and includes a shielding plate formed with a slit aligned with an optical path for subjecting a photosensitive member to exposure. The photo detector is provided below and adjacent to the light source, while the shielding plate is provided below and adjacent to a copy face of the original document.