Brother Kogyo Kabushiki-Kaisha

Brother Koygo Kabushiki Kaisha

Tatsuo Oishi

Atsuo Sakaida

Atsushi Hirota

Naoto Iwao

An ink-jet recording apparatus of one aspect of the invention comprises nozzles are arranged on an ink ejection surface in a matrix in a first direction in which a recording medium is conveyed and a second direction orthogonal to the first direction. The plurality of nozzles are grouped into a plurality of nozzle sets, each of the plurality of nozzle sets includes nozzles arranged along the second direction. The plurality of nozzle sets are spaced from one another in the first direction by first distances, each of the first distances is an integral multiple of a distance that is obtained by multiplying a unit distance by 2. The unit distance corresponds to a highest resolution among first resolutions with respect to the first direction of an image to be formed on the recording medium.

Ink-jet recording apparatus

In an inkjet head, 4n rows (n: a natural number) parallel to each other are formed in each of which nozzles are arranged on an ink ejection face of the inkjet head in one direction. All the nozzles constituting each row are arranged such that projection points of the nozzles obtained by projecting the nozzles on an imaginary straight line extending parallel to each row, from a direction parallel to a plane including the rows, and perpendicular to each row, are arranged on the imaginary straight line at regular intervals. The nozzles are arranged in a cycle corresponding to a distance between the projection points at both ends of 4n+1 projection points arranged on the imaginary straight line. The total of products each obtained by a peak value of a modulation transfer function defined by the arrangement of the nozzles, multiplied by a value of a visual transfer function at a spatial frequency corresponding to the peak value of the modulation transfer function, is not more than 0.10.

Inkjet head

An inkjet printer includes an inkjet head, a sheet supply unit and a sheet supply position switching unit. The sheet supply unit has two sheet trays corresponding to two printing positions of the inkjet head which are shifted from each other in the width direction of the sheet. The sheet supply unit is capable of selectively supplying a sheet narrower than the maximum printable width of the inkjet head from either one of trays to the inkjet head. The sheet supply position switching unit switches one of the sheet trays to the other based on the number of printings on the narrower sheet at each of the printing positions.

Inkjet printer

An inkjet head includes plural nozzles that eject ink. The nozzles are arranged so that (a) the nozzles are arranged in a first direction on an ink ejection surface to form a plurality of rows parallel to one another; and (b) when the nozzles are projected from a second direction, which is parallel to the ink ejection surface and perpendicular to the first direction, onto a virtual straight line extending in the first direction, projective dots of the nozzles are arranged at equally spaced intervals on the virtual straight line. A spatial frequency, which is determined based on an appearance interval of a most-distant adjacent projective dot pair in the first direction, is lower than a spatial frequency corresponding to a peak value of a visual transfer function.

Inkjet head and nozzle plate of inkjet head

The angles and sizes for each of the constituent members of the ink jet recording head is designed to satisfy the following relational expression:0&#xb7;&#x3b1;&#xb7;()&#xb7;()&#x2266;0. in which a0=1.87686, b0=0.31786, c0=&#x2212;0.18649, d0=&#x2212;1.09273, e0=3.97019, f0=0.93332 and K0=0.05307 are satisfied when N is a number of layers in one of a piezoelectric element, A is a number of active layers in the piezoelectric element, &#x3b1; is an angle [&#xb0;] which is one of internal angles of virtual lattices containing one of a cavity and forming a matrix and which is not higher than 90&#xb0;, Spin is an area [mm] occupied by one lattice in the matrix, Scav is an area [mm] occupied by the cavity contained in one lattice in the matrix, and Spzt is an area [mm] occupied by an active portion of the piezoelectric element provided in accordance with one lattice in the matrix.

Growing community of inventors

Nagoya, Japan

Tatsuo Oishi