Abstract: An improved method of electrophotographic color printing in which only a single pass of a drum or belt is needed for formation and transfer of the toner image onto a desired medium by utilizing a transparent drum or belt for the supportive member for the photoconductive material, and exposing from the inner side of the drum or belt. The invention includes, among others, a method of synchronous laser-beam exposure that provides improved registration of images, methods of exposure for small diameter drums, a method to achieve a longer-lived drum or belt, an improved fusing method, methods of improving the toning process, and methods to achieve an improved image quality.

Abstract: A free loop oscillator system including a set of successive delay elements connected in series forming a free running loop oscillator, a set of taps disposed between the delay elements, a circuit for determining the speed of the free-running loop oscillator, and circuit for choosing a given tap in response to the speed of the free-running loop oscillator. Such a system may be implemented as a part of interval timer, a printer controller, a frequency synthesizer, an FM modulator, a digital-to-analog converter, or any other device which requires the availability of finely addressable signals since the taps disposed between the delay elements present signals much finer than any presently available clock.

Abstract: A free loop oscillator system including a set of successive delay elements connected in series forming a free-running loop oscillator, a set of taps disposed between the delay elements, a circuit for determining the speed of the free-running loop oscillator, and circuit for choosing a given tap in response to the speed of the free-running loop oscillator. Such a system may be implemented as a part of interval timer, a printer controller, a frequency synthesizer, an FM modulator, a digital-to-analog converter, or any other device which requires the availability of finely addressable signals since the taps disposed between the delay elements present signals much finer than any presently available clock.

Abstract: A raster scanning print engine driver accomplished by establishing a pixel scan time period representing a pixel print area, generating a number of pixel signals independently representative of the position and of the length of each line segments to be printed in the pixel print area, and producing from the pixel signals a pulse width and position modulated print engine drive signal representative of the position and length of the line segments to be printed in the pixel print area.

Abstract: A raster print engine driver for generating from incoming data representative of a continuous tone or text image, a transition-modulated engine drive signal for causing the engine to reproduce the image as a series of modulated print lines, in which the driver establishes a cell scan time period representing the horizontal length along a print line of an elemental cell print area, and generates from the incoming data in the cell at least zero or two independently located drive signal transitions which cause the print engine to change state at selected points along the print lines to closely reproduce the image.

Abstract: A method of converting existing copiers to laser printer engines by externally attaching an apparatus to the copier with no significant alteration of the copier engine, and attachable in an easily removable manner. The apparatus consists of a laser together with an optical system having means for modulating and scanning the laser beam, which enters the copier and passes through the copier's existing imaging lens. The apparatus incorporates a specially designed field mirror that simplifies that optical system.

Abstract: Apparatus for directing a jet of fluid at a target to deposit a desired image thereon. The apparatus employs a nozzle with a pointed nozzle nib, a supply of fluid for the nozzle, and a pressure regulator controlling the pressure of the fluid at the nozzle upstream of the nib. The jet of fluid is accelerated from the nozzle nib and caused to flow to the target by the creation of an electric field in the region between the nozzle and the target. The fluid jet is substantially prevented from breaking up into droplets during flight by a combination of techniques so that the fluid flows to the target as a solid liquid filament or as a stream of mist-size droplets which are so small and so closely spaced that they behave like a solid liquid filament. The amplitude of the fluid flow is continuously modulated in response to an information signal by fluid surface pumping action or other means to produce the desired fluid image on the target.