Abstract: A device for developing an electrostatic latent image recorded on a photoconductive layer. The developing device comprises a doner roll for supporting a uniform layer of single-component developing material adjacent to the photoconductive layer. The doner roll is disposed as to create a space gap between the photoconductive layer and the doner roll. The doner roll is made of semiconductive material having a specific resistance ranging from 10.sup.6 to 10.sup.12 .OMEGA.cm. An electrical bias potential is applied across the gap, thereby establishing a field for transferring the developing material from the doner roll to the photoconductive layer.

Abstract: A thermal recording head is provided with a driving system wherein higher printing speeds may be obtained. Particularly, in the case where the image to be printed by a divided block of elements is totally black, all common driving terminals corresponding to the block are selected for simultaneous recording.

Abstract: An elongated light receiving element is formed with a plurality of parallel one dimensional light receiving arrays or lines, each of which is lead out from a substrate. Each line is tested to determine which line or lines are free of defects, and the remaining lines are disconnected from the power source. The device serves to increase the production yield of such devices, which are prone to defects when manufactured in large sizes.

Abstract: A microfilm copier includes a holding device for the aperature card or the like which is rotatable through a 90.degree. angle so that copying can be effected in either the lengthwise or widthwise direction of the sheet roll comprising the copying medium. The copied images may be of differing magnification in order to minimize the creation of blank, unused portions in the sheet.

Abstract: An optical data recordation and reproduction system comprising a first optical means modulates a light beam with digitized data and impacts this modulated light beam onto a photosensitive material, producing discontinuities in the photosensitive material corresponding to the data. A second optical means then directs a beam of unmodulated light onto this photosensitive material, and converts the resulting modulated light into an electric signal. An electric circuit then differentiates and samples the signal, producing the recorded digitized data via self-locking.

Abstract: A microfilm copying machine is provided with a variable width exposure slit controlled by a magnification setting, for decreasing the range of the light output quantity required of the light source. The device may also include a mechanism by which the exposure is varied in response to changes in magnification factor, the density of a film and variations in the quantity of light which reaches the photo-sensitive drum or like device.

Abstract: A method for the formation of a multi-nozzle ink jet is herein disclosed. In this method a single crystal silicon plate is masked and impurities are diffused upon its surface, creating regions of echant resistance. A second single crystal silicon plate is then grown onto the first, and is masked and etched. Due to the unisotropic etching properties of single crystal silicon plates, a groove is formed in the second plate, and a plurality of nozzles is formed in the first plate. This process yields a multi-nozzle ink jet of greater overall strength and utility, while eliminating the waste due to etching run common in the manufacture of conventional ink jets.