Abstract: In an ink-jet head having an orifice ejecting an ink for forming an image, the ink-jet head further has a water repellent film for repelling the ink on a surface of the orifice, and the water repellent film has a fluorine-containing polymer resin layer and a part having a perfluoropolyether chain or a perfluoroalkyl chain bonded on the layer, whereby an ink-jet head and an ink-jet printer having a water repellent film having high water repelling property to an oil-based ink and high abrasion resistance can be provided.

Abstract: There are provided frequency analyzing method and apparatus, and a spectrum analyzer capable of reliably detecting and displaying a radio wave even if the radio wave is a frequency spread or low level one. A signal to be measured existing in a frequency band to be measured is extracted by a plurality of measurement signal extracting devices, and each of the extracted plural signals to be measured is frequency analyzed to compute a correlation value with respect to the plural results of frequency analyses. If the computed correlation value is equal to or greater than a preset value, a decision that the signal to be measured exists in the analyzed frequency is rendered, and if the computed correlation value is smaller than the preset value, a decision that the signal to be measured does not exist in the analyzed frequency is rendered. The decision results are displayed.

Abstract: An inkjet head having an ink flow path communicated with an ink chamber to an inkjet nozzle and having an orifice plate to which the nozzle is formed. An ink-philic layer is formed on the surface of the ink flow path, and an ink repellent layer is formed on the surface of the orifice plate where the nozzle is formed. The ink-philic layer is made of amorphous silica or inorganic polymer of colloidal silica bonded with a polymer of (SiOR), and the ink repellent layer contains a compound having perfluoropolyether chain and alkoxysilane residue as a terminal.

Abstract: A correlation function measuring method and apparatus can correct a correlation vector with high accuracy. The correlation function measuring apparatus includes first signal processing means 18a to 22a for processing a first monitored signal to give a first spectrum, second signal processing means 18b to 22b for processing a second monitored signal to give a second spectrum, correction value computing means 26 for inputting correction signals to the first and second signal processing means to give correction values corresponding to respective frequencies, based on the first spectrum and the second spectrum, and correlation function computing means 30 for obtaining a correlation function between the first spectrum and the second spectrum by using correction values given by the correction value computing means.

Abstract: The object of the present invention is to provide an inkjet head characterized by better ink repellency, greater resistance to abrasion and a longer service life than a prior art product.

Abstract: A print head for ink jet printer having a reduced length in a main scanning direction and an elongated length in an auxiliary scanning direction perpendicular to the main scanning direction. A plurality of linear print head modules are arrayed in the auxiliary scanning direction, and each linear print head module extends in a slanting direction with respect to the main scanning direction by a predetermined angle. Further, each linear print head module has a width in a direction perpendicular to its extending direction. The slanting angle and the width determine scanning pitch extending in the auxiliary scanning direction and can reduces the length of the print head in the main scanning direction.

Abstract: To provide a correlation function measuring method which can correct a correlation vector with high accuracy. There are provided first signal processing means 18a to 22a for processing a first monitored signal to give a first spectrum, second signal processing means 18b to 22b for processing a second monitored signal to give a second spectrum, correction value computing means 26 for inputting correction signals to the first signal processing means and the second signal processing means to give correction values corresponding to respective frequencies, based on the spectrum given by the first signal processing means and the spectrum given by the second signal processing means, and correlation function computing means 30 for giving a correlation function between the first spectrum and the second spectrum by using correction values given by the correction value computing means.

Abstract: A rotary polygon mirror device comprises: a rotor including a polygon mirror secured to one end face of a cylinder, a central rod secured inside said cylinder in such a manner that the central rod is extended along the axis of the cylinder, and a thrust bearing magnet secured to the end face of the central rod, said magnet; and a casing coaxially surrounding the cylinder with a gap therebetween. In the device, the gap provides radial bearing means, and the cylinder and the casing are made equal in thermal expansion coefficient.

Abstract: In an electrostatic printing machine, a paper curl correction apparatus can vary the amount of curl correction provided by rotating paper guide rollers around a shaft on which paper conveying rollers are provided. As a result, angle between the shaft and a circumference of the paper guide rollers can be varied.

Abstract: A paper feed device for holding a stack of printing paper sheets, has a paper holder box, a paper support bed on which the paper sheets are adapted to be placed and an elevator mechanism for moving the paper support bed upward and downward, a sensor detects the height of the paper sheets, whereby at the time of supply of the paper sheets, the paper support bed is moved downward so that the level of the paper sheets can be at a predetermined height relative to an upper end of the paper holder box.

Abstract: A sheet reversing apparatus comprises a support in which sheets are stacked, an entrance section for guiding the sheet to the support, a blowing mechanism for directing an air stream to a sheet stack on the support to separate a lowermost sheet from remaining sheets, and a feeding mechanism for attracting the sheet to feed it. Further, stopper plates are provided to be pivoted above the support so that it cooperates with the support to pinch and brake the sheet therebetween in a continuous reversing mode wherein the incoming sheet is immediately fed and that it abuts against the incoming sheet by a portion thereof opposing a leading end of the sheet in a stack reversing mode wherein while the sheets are being stacked the lowermost sheet is separated and fed.

Abstract: In an electrophotographic printing mechanism in which a photosensitive drum mechanism having a photosensitive drum and a drum cap is turned to electrostatically form an image on the photosensitive material wound on the drum, the drum cap is provided with a switch which is operated by a switch control unit, so that when the mechanism is stopped for urgent work, the operator is protected from being struck by electricity touching the drum cap.

Abstract: A dot-line printer has a hammer bank carrying a plurality of printing hammers arranged in groups, each group having a predetermined number of printing hammers displaced from one another by predetermined numbers of dot-lines in the direction of paper feed. A shuttle mechanism causes the hammer bank to undergo reciprocating shuttle movements with a reversing period between successive shuttle movements. A character line, covering a predetermined number of dot-lines, is printed over a plurality of shuttle movements, a paper feed mechanism causing the paper to move a predetermined number of dot-lines in the reversing period between shuttle movements. A number of blank dot-lines separate a printed character line from the beginning of the first dot-line of the next character line to be printed.

Abstract: A dot matrix type printer head in which delays in the release of print hammers are eliminated by providing release coils only in alternate hammer positions, or alternatively, activating at one time only release coils in one of even-numbered and odd-numbered hammer positions. A rear yoke and a permanent magnet affixed to a lower leg of the rear yoke are provided in common for all hammer positions. An upper leg of the rear yoke is divided into a plurality of pole pieces. Hammer elements are provided having lower ends rigidly affixed to the rear yoke at positions adjacent the permanent magnet and upper ends retractable against pole faces of corresponding pole pieces by the magnetic force of the permanent magnet. In a first preferred embodiment of the invention, release coils are provided around only even-numbered or odd-numbered pole pieces.

Abstract: A printing mechanism is provided with a counter-balanced hammer bank such that the hammer bank and a counterweight are oppositely reciprocated by a pair of cams mounted on a vertically oriented cam shaft. Vibration of the printer even at high speed can be eliminated by completely dynamically balancing the system.

Abstract: A dot printer in which vibration is eliminated without the use of a separate counterweight. The printer includes first and second hammer banks each holding a plurality of dot printing elements. The first and second hammer banks are spaced apart from each other a predetermined distance in the direction in which a printing sheet passes. A motor and oppositely-phased drive cams reciprocate the two hammer banks in opposite directions parallel to a dot printing direction.

Abstract: A printing apparatus including a plurality of drive coils for driving printing hammers arranged longitudinally in side-by-side relation at one side of a core of the U-shape. A first cooling fluid passageway is defined inside the core of the U-shape to allow a cooling fluid for cooling the drive coils to flow therethrough, and a second cooling fluid passageway is defined outside the core by a duct to allow the cooling fluid for cooling the drive coils to flow therethrough without escaping to the outside by diffusion. A current of cooling fluid is forcibly fed into these cooling fluid passageways by a fluid machine.

Abstract: A printing mechanism is provided with a counter-balanced hammer bank such that the hammer bank and a counterweight are oppositely reciprocated by a pair of coaxial, identical, orthogonally oriented cams. Vibration of the printer even at high speed can be eliminated by completely dynamically balancing the system.