Abstract: A printing head for an ink jet printer is provided with a plurality of ink jet sets. Each of the ink jets. Each of the ink jets includes an ink nozzle through which ink is ejected; a pressure chamber communicated with the ink nozzle and having a diaphragm made of a flexible plate; and a piezoelectric member bonded on an outside of the diaphragm for deforming the diaphragm to eject ink through the ink nozzle from the pressure chamber. The piezoelectric member includes a layer, having titanium an upper PZT layer chemically bonded on an upper surface of the titanium layer and polarized in a first direction; and a lower PZT layer chemically bonded on a lower surface of the titanium layer and polarized in a second direction opposite to the first direction.

Abstract: An ink jet printing apparatus includes a sheet transporting mechanism for transporting a printing sheet along a vertical plane; a first printing head unit provided on a horizontal plane perpendicularly intersecting the vertical plane and having an ink emission portion for emitting ink to one side surface of the printing sheet; and a second printing head unit provided on a horizontal plane perpendicularly intersecting the vertical plane and having an ink emission portion for emitting ink to the other side surface of the printing sheet.

Abstract: An ink jet printing apparatus includes a printing head operable to emit ink onto a printing sheet, the printing head being movable along a first direction; a sheet transporter operable to transport the printing sheet along a second direction perpendicular to the first direction; a head moving mechanism operable to reciprocally move the printing head along the first direction; and a controller which controls the sheet transporter and the head moving mechanism to execute a first printing mode of moving the printing head while holding the printing sheet in a stationary position and a second printing mode of moving the printing sheet while holding the printing head at a stationary position.

Abstract: A sheet transporting device for use in an image forming apparatus includes a first and second sheet transporting members movable in widthwise directions of sheet to be transported, the first sheet transporting member for transporting the sheet in a lengthwise direction of the sheet in contact with one side end portion of the sheet, the second sheet transporting member for transporting the sheet in the lengthwise direction in contact with the other side end portion of the sheet; a moving mechanism for moving the first and second sheet transporting members in widthwise directions of the sheet: a sheet feeder provided at an upstream of the first and second sheet transporting members for holding the sheet temporarily and feeding the sheet to the first and second sheet transporting members; and a controller for controlling the moving mechanism and the sheet feeder to move the first and second sheet transporting members until they come into contact with the sheet while rendering the sheet feeder hold the sheet.

Abstract: Conveying devices, operation of which is stopped during printing, are provided upstream and downstream, as seen in a direction of conveying of a paper, of a platen arranged to face a printing head. The platen is provided with an electrostatic attraction member electrostatically the paper by the application of a voltage. A first control applies the voltage to the member during printing until a leading end of the paper arrives at the downstream conveying device. A second control applied the voltage to the member during printing after conveyance of a trailing end of the paper by the upstream conveying device is completed. Thereby, lifting of the end portions of the paper away from the platen is prevented, thus avoiding unprintable margins at such end portions of the paper.

Abstract: An apparatus for generating clock pulses comprises a Colpitts-type quartz crystal oscillator having an inverter composed of a C-MOS integrated circuit, and a quartz-crystal resonator connected with said inverter, and an amplifying circuit for amplifying the output of said quartz-crystal oscillator and delivering clock pulses as output. A first resistor is provided between the input terminal of the inverter and the quartz-crystal resonator, and the input terminal of the inverter is connected with the input terminal of the amplifying circuit. The amplifying circuit is for connection with a load composed of TTL circuits. This amplifying circuit includes a capacitor for suppressing a direct-current bias voltage from the output of the oscillator, an inverter composed of a C-MOS integrated circuit for providing the clock pulses as output, and a negative feedback circuit which utilizes negative feedback to the inverter as a direct-current bias voltage corresponding to the duty ratio of the clock pulses.

Abstract: A developing apparatus includes a developing roller which conveys developer on the surface thereof by the rotation in a predetermined direction. The developer conveyed thereon to develop a latent image formed on an image-holding device. A supply roller rotates keeping contact with the developing roller and by the rotation of which the developer is supplied to the developing roller. A regulating member regulates the amount of the developer to be conveyed on the surface of the developing roller. The supply roller is so disposed that the axis thereof is positioned lower than that of the developing roller while the top thereof is also positioned lower than that of the developing roller.

Abstract: An automatic image-density control system for photo-copying the page-to-page content of an open book, in which optimum values (of exposure or development bias) needed for precisely copying the page-to-page content are initially established by performing either continuous pre-scanning of both pages of an open book or pre-scanning of the second page after completing photo-copying of the first page, and then, based on the optimum values thus established in conjunction with the first page content, photo-copying operation for the first page content is executed, and then, based on the optimum values established for the second-page content, photo-copying operation is sequentially executed for the second-page content.

Abstract: An image-forming apparatus equipped with an optical means, an electrostatic image-forming means and a control means. The optical means projects a scanned light beam to be controlled according to an image to be formed. The image-forming means receives the scanned light beam projected from the optical means and forms an image corresponding to the scanned light beam. The control means controls the optical means and the image-forming means.

Abstract: An image-forming apparatus equipped with an optical means, an electrostatic image-forming means and a control means. The optical means projects a scanned light beam to be controlled according to an image to be formed. The image-forming means receives the scanned light beam projected from the optical means and forms an image corresponding to the scanned light beam. The control means controls the optical means and the image-forming means.

Abstract: This invention relates to a binder comprising (a) a polyamine-epichlorhydrine resin obtained by reacting epichlorhydrine with a polyamine resin having at least 2 amino groups per molecule; and (b) an amphoteric high molecular compound having at least 2 cation groups and at least 2 anion groups per molecule.