Abstract: Reproducing a predetermined pattern on a medium, by for example, an apparatus that includes in combination a source of colored ink, a primary source of compressed air, a spray head including a housing having an inner ink chamber in flow communication with the source of ink, an outer air chamber in flow communication with the source of air and surrounding the inner ink chamber, a spray nozzle having an outside diameter and an internal longitudinal bore connected to the inner ink chamber and extending forward of the housing. A spray shield has an outer surface adjacent the medium and an inner surface positioned adjacent to and spaced from the housing and has a transverse opening therethrough in alignment with the nozzle. An auxiliary air supply has a pressure significantly less than the pressure of the air from the primary source of compressed air.

Abstract: Reproducing a predetermined pattern on a medium, by for example, an apparatus that includes in combination a source of colored ink, a primary source of compressed air, a spray head including a housing having an inner ink chamber in flow communication with the source of ink, an outer air chamber in flow communication with the source of air and surrounding the inner ink chamber, a spray nozzle having an outside diameter and an internal longitudinal bore connected to the inner ink chamber and extending forward of the housing. A spray shield has an outer surface adjacent the medium and an inner surface positioned adjacent to and spaced from the housing and has a transverse opening therethrough in alignment with the nozzle. An auxiliary air supply has a pressure significantly less than the pressure of the air from the primary source of compressed air.

Abstract: An automatic system for the spray painting of color images in which accurate color reproduction is achieved by a separate look-up table generated for each jet and stored in the computer memory. During the reproduction of an image, the computer uses the look-up tables to determine the pulse width of an air modulation stream to reproduce the precise color density called for by the input data. Because slight variations in the characteristics of two jets spraying the same color would produce objectionable lining in the image, a separate look-up table is provided for each jet. A color test image is generated for a selected jet by successively varying the width of the pulse modulation from the minimum to the maximum. For example, while the jet is making a single scan across the medium, the pulse width modulation of the air stream is varied in 256 separate steps to produce a test image that varies from the lightest to the darkest density of the particular color being sprayed.

Abstract: A system for reproducing color images by electronically scanning an original to control the paint-spraying of a larger duplicate image. Multiple ink spray heads scan the width of the recording medium while being controlled by width-modulation of constant air pressure supplied to the heads. Ink is contained in multiple reservoirs that are each connected to one of the spray heads by a conduit extending substantially perpendicular to the direction of travel of the spray heads. Each ink reservoir contains a sub-reservoir with a bottom surface above the level of the bottom surface of the primary reservoir. Sloping deflector plates cause ink to flow from the primary reservoir into the sub-reservoir during acceleration or deceleration of the reservoirs. The height of the ink in the reservoir is such that a meniscus of ink is maintained on the tip of the spray jet during periods when ink is not being sprayed.

Abstract: A system for copying images onto a long sheet of paper or vinyl while. A flow of constant-pressure air is pulse-width modulated in accordance with the control signals and passed over an ink meniscus maintained on the end of a small nozzle. The pulse-modulated air flowing across the meniscus causes the ink to be sprayed onto the recording medium. The dot size on the image remains constant and the pulse width within each pixel is varied to produce the desired density of color. Pressure surges in the ink supply system, produced for example by vibration or acceleration of the ink, are suppressed by a second meniscus in the ink-supply system, formed by a gas bubble or interface near the nozzle meniscus. The second meniscus should have a surface area at least as large as that of the jet meniscus. At the end of each pixel, the ink flow is interrupted for a period of about 100 microseconds to restore system equilibrium.

Abstract: The invention is embodied in a pressurized ink supply system for a three color ink jet printer. In order to provide a relatively large ink supply, three stationary primary ink reservoirs, formed as three long tubular sacks of flexible plastic film, contained in a pressurized disposable cartridge, are connected through flexible plastic umbilical tubes, and three solenoid-operated valves, to three secondary ink reservoirs mounted on the movable carriage of the print head. Automatic ink replenishment and an out-of-ink alarm are controlled entirely from the secondary ink reservoirs.The ink level in each secondary reservoir is maintained within close limits without attention from the operator. When the primary reservoir runs out of ink, as indicated by failure of the secondary reservoir to fill within a specified time period, an alarm alerts the operator to remove and replace the ink cartridge.

Abstract: In a jet drop recording system a drop catcher includes a drop impinging face having a narrow slot at its lower edge so that drops impinging on the face may travel over it to the slot for removal from the system. A reduced pressure is maintained in the catcher to draw the recording material through the slot and the size of the slot and the pressure differential across it are adjusted so that a meniscus is formed at the mouth of the slot. The surface tension of the recording material then acts in opposition to the reduced pressure tending to draw the material into the catcher and maintains the slot full of recording material. This meniscus, in effect, forms a "seal" which prevents air from being drawn into the catcher and eliminates air currents in the vicinity of the catcher which might affect the trajectory of drops intended for deposit on the receiving member.