Abstract: An image forming method is disclosed in which an image is formed on commercial printing paper using a high penetration pigmented ink by performing image processing which makes use of dot patterns corresponding to an output halftone level.

Abstract: This patent specification describes a droplet-ejecting head including a nozzle substrate having a plurality of nozzles for ejecting droplets, and an actuator configured to be driven to generate energy for ejecting droplets through each nozzle. The nozzle substrate is cleaned by a cleaning liquid containing microbubbles before being bonded to another member.

Abstract: An image processing method of processing image data includes a color space conversion step of converting an input color signal of image data into an output color signal having cyan (C), magenta (M), and yellow (Y) values; a black generation/under color removal step of converting the CMY values into cyan (C), magenta (M), yellow (Y), and black (K) values by adding a black (K) value and decreasing the CMY values so that portions of cyan (C), magenta (M), and yellow (Y) recording liquids used to form the image data are replaced with a black (K) recording liquid; and a total amount control step of controlling amounts of cyan (C), magenta (M), yellow (Y), and black (K) recording liquids calculated from the CMYK values so that a total amount of the CMYK recording liquids per unit area on a recording medium does not exceed a predetermined total amount limit.

Abstract: This patent specification describes a droplet-ejecting head including a nozzle substrate having a plurality of nozzles for ejecting droplets, and an actuator configured to be driven to generate energy for ejecting droplets through each nozzle. The nozzle substrate is cleaned by a cleaning liquid containing microbubbles before being bonded to another member.

Abstract: An image processing method of processing image data includes a color space conversion step of converting an input color signal of image data into an output color signal having cyan (C), magenta (M), and yellow (Y) values; a black generation/under color removal step of converting the CMY values into cyan (C), magenta (M), yellow (Y), and black (K) values by adding a black (K) value and decreasing the CMY values so that portions of cyan (C), magenta (M), and yellow (Y) recording liquids used to form the image data are replaced with a black (K) recording liquid; and a total amount control step of controlling amounts of cyan (C), magenta (M), yellow (Y), and black (K) recording liquids calculated from the CMYK values so that a total amount of the CMYK recording liquids per unit area on a recording medium does not exceed a predetermined total amount limit.

Abstract: An ink jet printing head includes: a plurality of piezoelectric actuators arranged in rows on a substrate, each row including first piezoelectric elements and second piezoelectric elements which are alternately arrayed along the row, the first piezoelectric elements being actuatable to apply a compressive force to ink in accordance with print signals, the second piezoelectric elements being fixed and not actuated; and an ink chamber unit which includes ink chambers located above the first piezoelectric elements and containing ink.

Abstract: An ink jet recording apparatus includes a recording head for ejecting droplets of ink and a driving circuit for driving the recording head. The recording head includes a base, a plate on which a plurality of openings are formed; an ink chamber to be filled with ink being formed between the base and the plate; and heater elements, provided in the ink chamber so as to face the openings of the plate, each of which heater elements supplies heat energy to ink adjacent thereto so that the air bubble is generated on each of the heater elements and so that the air bubble grows toward a corresponding one of the openings. An area of each of the openings of the plate is greater than an area each of the heater elements. When the driving circuit activates each of the heater elements, a droplet of ink is ejected due to the air bubble from the corresponding one of the openings of the plate.

Abstract: An apparatus for measuring the refractive index of liquid particularly suitable for use in an ink-jet printing system is provided. The apparatus includes a light emitting diode and a photodiode which are optically coupled by an optical fiber which in turn is partly immersed in a liquid to be measured. In one aspect, the wavelength of light emitted from the light emitting diode is so set to be outside a light absorption wavelength range of the liquid to be measured. In another aspect, provision is made of a temperature dependent resistor which changes its electrical resistance depending on the temperature of the liquid to be measured so as to vary the level of the driving current to be applied to the light emitting diode thereby varying the amount of light to be emitted.

Abstract: An ink supply system for use in an ink-jet printer includes a main block preferably comprised of a plastic material and defining part of a carriage of the printer. A valve assembly having an ink chamber is incorporated in the main body which controls the flow of ink from an ink reservoir formed in the main block to an ink-jet nozzle head mounted on the carriage. A plurality of ink passages are formed inside of the main body establishing fluidic communications between the ink reservoir, ink chamber and the nozzle head, thereby requiring to provide no tubing.

Abstract: A sheet is disposed around the outer peripheral surface of a drum. The drum is provided with sheet suction holes for attracting the sheet against the drum surface. The sheet suction holes extend through the drum from the interior to the exterior thereof, and are disposed in a plurality of circumferentially spaced rows. Each of the rows includes a plurality of sheet suction holes and is connected to suction means, which is operable to withdraw air outside the drum into the interior thereof through the row of suction holes. At least the leading edge of the sheet is retained by a sheet seizing claw which is movable toward or away from the drum surface. The claw is urged into abutment against the drum surface under the influence of a centrifugal force as the drum rotates.

Abstract: An ink level detector for use with an ink jet printer includes two electrodes for sensing changes in ink level inside an ink reservoir due to consumption. Fresh ink is supplied to the reservoir from an ink cartridge which is mounted in an upper wall of the reservoir. At least one of the two electrodes is positioned adjacent to a location where the cartridge is mounted to the upper wall of the reservoir.

Abstract: A disposable container for collecting waste liquid is disclosed. A casing has therein an absorption member for absorbing waste liquid toward the interior of the casing, and a liquid holding member held in contact with the absorption member to retain the waste liquid absorbed by the absorption member. The receptacle is applicable to an ink jet recording apparatus for collecting waste ink. A fresh ink container may be combined with the waste ink receptacle in an integral cartridge configuration to be mounted in an ink jet recorder.

Abstract: A paper loading apparatus includes a paper retaining roller and a stop claw, both arranged for movement toward or away from a platen in opposite directions from each other. When the stop claw bears against the platen, paper is inserted into the apparatus and is properly held by the claw. Subsequently, the paper retaining roller is brought into abutment against the platen, whereupon the stop claw is moved away from the platen. The movement of the roller and the stop claw toward or away from the platen occurs automatically in response to a detection signal which indicates the insertion of the paper into the apparatus. In one embodiment, the platen is peripherally formed with a plurality of axially spaced annular grooves which extend in a direction perpendicular to the axis thereof, and receive protuberances formed on the free end of the stop claw.

Abstract: An ink ejection head having a body and a nozzle member which is mounted on the head body through a nozzle holder. To facilitate the ease of machining, the nozzle member is formed with a generally cup-shaped recess first and then a nozzle hole for ejecting ink. The space defined between the wall of the cup-shaped recess and the nozzle holder is filled with a projection extending from the nozzle holder or a flexible member. A passageway extends throughout the projection or the flexible member to provide fluid communication between the nozzle hole and an ink chamber defined in the head body. The projection or the flexible member minimized a diametrical step conventionally defined between the nozzle hole and the cup-shaped recess, so that bubbles drawn into the nozzle hole upon termination of an ink ejection can be released to the outside within a short period of time.

Abstract: An ink ejection head including a nozzle holding member having an ink ejection nozzle threadably connected to a forward end portion of a liquid chamber structure. The ink ejection heads further includes a sealing member, such as a packing or an O-ring, located inwardly of a threaded connection as viewed from a liquid chamber in the liquid chamber structure. Introduction of dust or grit through the threaded connection into the liquid chamber can be effectively avoided by this arrangement, to thereby prevent obturation of the ink ejection nozzle.

Abstract: A sheet receptacle is provided which is capable of carrying a multiplicity of sheets to be separated and conveyed, in theform of a stack. A suction device which shaped like an inverted cup is located above the receptacle and is supported by an associated support member. A piping connects the suction device with an air suction source, which may be operated to apply an air suction. The sucker support member forms part of a mechanism which imparts a rotary motion to the suction device, which is also associated with another mechanism which causes a movement of the suction device in the vertical direction as well as in the fore-and-aft direction. An air intake opening may be formed in the air flow path which connects the suction device with the air suction source, and is provided with a sheet receiver which can be covered by a sheet to be separated and conveyed or a sheet which is equivalent thereto.

Abstract: In an ink-jet printing head of the type in which the front end of an ink distribution tube is formed with a nozzle hole and the rear end thereof is terminated into a spigot and inserted into one end of the ink supply tube and rigidly connected thereto, a resonance adjusting means has an ink passage of a fine diameter extended therethrough in the axial direction thereof and is inserted into the spigot end portion of the ink distribution tube in such a way that the front end of the resonance adjusting means is spaced apart from the front end with the nozzle hole of the ink distribution tube by a distance equal to a resonance distance, at which the ink in the ink distribution tube is resonated, and thereafter rigidly and liquid-tightly connected to the spigot end portion.

Abstract: A drum (13) is provided with vacuum openings (14), (16), for suckingly holding a sheet (19) thereto for printing or the like. A sheet feed failure is detected by sensing for a drop in the level of vacuum at a vacuum source (12) below a predetermined value. Several regulators (36), (37), (38), (39) are provided for regulation to selected levels of vacuum.