Abstract: Oxygen content in the exhaust gas of a combustion system is controlled such that the actually detected value of the oxygen content is compared with a set value which is varied in accordance with the combustion load of the system. A value theoretically adapted to control an air-fuel mixing ratio is calculated from the combustion load and the result of the comparison, and the flow rates of air and fuel supplied to the combustion system are controlled according to this value.

Abstract: After a photosensitive drum is cleaned of residual toner by a scraper blade, a lubricant film is applied to the drum to maintain the coefficient of friction between the drum and blade constant and thereby ensure efficient cleaning and printing density without damage to the drum. The film forming material is in the form of a block and is applied to the drum by a rotary brush. The brush is selectively moved into and out of engagement with the drum to control the amount of film application. The engagement of the brush with the drum is controlled in accordance with a sensed parameter such as a number of copies produced, the coefficient of friction between the drum and a sensor blade, etc.

Abstract: A cleaning device for a photoelectrostatic copying apparatus has a cleaning blade and a cleaning roller adapted to be brought into pressing engagement with a photosensitive member to effect cleaning thereof after transfer printing. The cleaning blade is brought out of contact with the photosensitive member and the cleaning roller is either brought out of contact with the photosensitive member or has its contact pressure reduced when the apparatus is inoperative, whereby damage to the photosensitive member due to the pressing engagement of the photosensitive member with the blade and the roller can be avoided or minimized.

Abstract: A sheet supply includes a sheet supply roller disposed for contact with copy sheets housed in a cassette for feeding forward one copy sheet at a time and a guide roller which is disposed on the outer side of the sheet supply roller. The guide roller is loosely mounted on the axis of the sheet supply roller so as to be movable in the direction of its diameter and such that it rotatably contacts the copy sheets under its dead weight.

Abstract: An auto-bias developing process for developing an electrostatic latent image formed on a photosensitive member which includes the step of storing a detected potential in order to apply a fixed bias potential to a developing electrode plate wherein the surface potential of a photosensitive member is detected through a developing solution by a sensor electrode, and is stored in a memory circuit for subsequent conversion to a fixed bias potential which corresponds to the detected potential and is applied to the developing electrode. The process also includes the step of removing any toner which attaches to the developing electrode plate, by the application of a reverse bias potential thereto when the developing process is not taking place and the step of rendering the developing electrode plate electrically floating for removing toner from the plate and preventing deposition of toner onto the surface of the photosensitive member.

Abstract: A rotary valve disposed in a conveying passage for a powdery or granular material and comprising a valve casing and a valve member of arcuate cross section. In full closed position, the inner peripheral surface of the valve member is directed toward the flow of powdery or granular material to shut off the material flow, but in full open position, the valve member is rotated to permit conveyance of the powdery or granular material through an opening bored therein.

Abstract: An exposure controlling apparatus for electrophotographic copying machines comprises an operating member which is operable externally of the machine to control the amount of exposure. The operating member is normally biased to return to its neutral position, but can be temporarily held in its operative position when operated. The temporary retention is released upon completion of a copying operation, allowing the operating member to return to its neutral position.

Abstract: A reel drive roller and a tape draw-out roller larger in diameter than the reel drive roller and formed with irregularities on its peripheral surface are rotatably mounted coaxially on support means. When the support means is swung toward the opening in a cartridge, the reel drive roller engages a flange of a tape reel to rotate the tape reel to expand the outer convolutions of the wound tape radially outwardly, and the tape draw-out roller engages the outer convolutions under some pressure to feed the leading end of the tape to a capstan roller associated with a pinch roller which is formed with irregularities on its peripheral surface. The capstan roller and the pinch roller feed the tape which is drawn out in this manner to a tape take-up reel.