Abstract: Disclosed is a process for the preparation of lead compounds which comprises reacting lead monoxide according to the wet method with an inorganic acid or organic acid in the presence of hydroxylamine under such conditions that the initial pH value of the reaction system is not higher than 7.Lead monoxide according to the wet method has an excellent reactivity with an inorganic acid or organic acid, but it contains higher oxides such as lead dioxide and minium, which cause coloration in lead compound products. According to this process, this undesirable coloration can effectively prevented.

Abstract: A copying or printing machine includes processing units operative for reproducing a copy of an original, a read-only memory having program sequences stored which are composed of coded steps necessary for accomplishing printing or copying cycles, and a random-access memory in which a set of coded signals may be written in and read out. The processing units are actuated in response to coded signals in accordance with the program sequences.

Abstract: A copying apparatus comprises a recording medium, process means for forming an image on the recording medium including image transfer means for transferring the image formed on the recording medium to a transfer medium, feed means for feeding the transfer medium to an image transfer station, memory means for storing the operating time of the feed means so that the leading end of the image on the recording medium and the leading end of the transfer medium are brought into a predetermined relationship, and control means responsive to the output of the memory means to control the time whereat the feed means operates.

Abstract: An image forming device having a plurality of image forming modes to enable an image reproduced member to be formed under various conditions, in which a predetermined image forming mode is selected out of the abovementioned image forming modes and automatically set when the power source is turned on, or after the image formation has been finished, or in other particular states.

Abstract: Disclosed is an image forming apparatus of a type, in which there is provided first and second electrically chargeable members, a first processing device to form a primary electrostatic latent image on the first chargeable member, a second processing device to form a secondary electrostatic latent image of the second chargeable member in accordance with the primary electrostatic latent image, to develop the secondary electrostatic latent image, and to transfer the thus developed image onto an image transfer material. A detecting device is provided to detect the visible image forming capability of at least one of electrostatic latent images; and, a control device is provided, responsive to the detecting device, to control at least one of the first and second processing devices so as to form a developed image of a predetermined image density.

Abstract: There is disclosed a method of maintaining at a desired level the temperature of components in a copying machine which is in its idle state. An electric power is supplied members in the machine having an impedance component after the copying operation has been stopped. The voltage of the power must be set at a value lower than the rated voltage of the members.