Abstract: The present invention is directed to a piezoelectric ink jet head wherein the partition walls that separate the adjacent recesses that make the pressure chambers are formed to have such a cross sectional shape as the width W1 in the planar direction at the upper end on the side of the substrate where the drive section is formed and height H in the direction of substrate thickness satisfy the expression (1): W1?H??(1) while the width W1 and W2 of the lower end at the bottom of the recess of the substrate in the planar direction satisfy the expression (2): W1?W2??(2) in order to prevent the dot size and dot shape of the picture to be formed from varying as the state of driving the individual drive regions or the state of driving the individual piezoelectric elements are influenced by the state of driving the other plurality of drive regions or the state of driving the individual piezoelectric elements that surround the former.

Abstract: The azo-metal chelate dye to which the present invention is applied is a compound formed as follows: for example, 1,3,4-thiadiazole ring is selected as the diazo component; the diazo component is combined with a coupler component having condensed rings including a fluorine-substituted alkylsulfonylamino group and an amino group, to form an azo dye compound; and the azo dye compound forms chelate bonds with at least one metal selected from the group consisting of Co, Ni, Cu and Pd. Here, two absorption bands (OD1 and OD2) are seen in the absorption spectrum, which is measured in a range of 400 to 800 nm wavelengths. The azo-metal chelate dye is characterized in that the optical density ratio (OD2/OD1) of the two absorption bands is greater than 1.25. By using this azo-metal chelate dye, an optical recording medium capable of high-speed recording is provided.

Abstract: The present invention is directed to a method for driving a piezoelectric ink jet head comprising a piezoelectric actuator AC that includes two piezoelectric ceramic layers 7a, 7b having such a size that covers the plurality of pressure chambers 2, wherein an electric field of opposite sense to the polarizing direction is applied to the second piezoelectric ceramic layer 7b by using the common electrodes 8a, 8b and, (1) for the pressure chambers 2 from which the ink is discharged, an electric field of the same sense as the polarizing direction of the layer is applied to the first piezoelectric ceramic layer 7a by using the individual electrode 10 and the first common electrode 8a, thereby causing the region of the piezoelectric actuator AC to deflect toward the pressure chamber 2, while (2) for the pressure chambers 2 from which the ink should not be discharged, an electric field of the opposite sense to the polarizing direction is applied to the first piezoelectric ceramic layer 7a by using the electrodes 10

Abstract: The present invention is directed to a piezoelectric ink jet head wherein contacts for the electrical connection of the upper and lower electrodes that sandwich the piezoelectric element on the upper and lower sides are disposed in a solid region of the substrate where any of recess to make the pressure cavity, common feed path, feed port, nozzle passage or nozzle is not formed, in order to surely prevent the vibration characteristic of individual drive regions or individual piezoelectric element from varying.

Abstract: The present invention is directed to a piezoelectric ink jet head wherein the partition walls that separate the adjacent recesses that make the pressure chambers are formed to have such a cross sectional shape as the width W1 in the planar direction at the upper end on the side of the substrate where the drive section is formed and height H in the direction of substrate thickness satisfy the expression (1):

Abstract: The present invention provides a method for driving a piezoelectric ink jet head that surely suppresses the ensuing vibration of the drive section while suppressing the flying speed of the ink droplet from decreasing, by setting the time constant &tgr;UP of rise of voltage when the drive voltage is applied and/or the time constant &tgr;DN of fall of voltage when stopping the application of the drive voltage are set in ranges that satisfy the relations of the expressions (i) and (ii):

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.