66results about How to "Uneven inhibitory concentration" patented technology

A magnetic toner having magnetic toner particles each containing at least a binder resin and a magnetic iron oxide particle, in which: when a solution is prepared by dissolving the magnetic iron oxide particles in an acidic aqueous solution and an Fe element amount in a solution in which all the magnetic iron oxide particles are dissolved is defined as a total Fe element amount, a ratio X of the amount of Fe(2+) in a solution in which the magnetic iron oxide particles are dissolved to a state where 10 mass % of the total Fe element amount is present in the solution (solution having an Fe element-dissolving ratio of 10 mass %) to an Fe element amount in the solution having a specific Fe element-dissolving ratio; and the dielectric loss tangents of the magnetic toner measured at a temperature of 40° C. satisfy specific conditions.

A data processing method, printing apparatus, host apparatus, and printing system are capable of reducing the data transfer rate from the host apparatus to the printing apparatus, suppressing density unevenness, and reducing the cost of the apparatus.

Provided are an inkjet printing apparatus and inkjet printing method that can, regardless of an ejection frequency of a print head, stabilize density of an image expressed on a print medium. For this purpose, an ink concentration integrated value is obtained according to the ejection history of each nozzle so as to be increased by data indicating non-ejection of the nozzle or decreased by data indicating ejection. Then, image data on the target pixel is corrected such that density of the target pixel is further reduced as the pixel is subjected to printing by a nozzle having a higher ink concentration integrated value.

A liquid jetting apparatus jetting a liquid onto a recording medium conveyed in a first direction includes head units arranged in a second direction orthogonal to the first direction. One head unit includes nozzle chips; one nozzle chip has a nozzle arrangement area wherein nozzles are aligned in a third direction crossing the first and second directions. The nozzle chip is arranged to be shifted relative to another nozzle chip in a direction crossing the first and second directions and different from the third direction. The head unit has a first overlapping portion wherein nozzle arrangement areas of first and second nozzle chips included in the nozzle chips partially overlap with each other in the first direction. The liquid jetting apparatus has a second overlapping portion wherein nozzle arrangement areas of third and fourth nozzle chips included in the head units partially overlap with each other in the first direction.

Density unevenness caused in an image formed with an overlap portion of nozzles is suppressed. For this purpose, a method of determining an ink ejection method includes: transporting a medium in a transporting direction; forming an image with a nozzle unit having a plurality of nozzle rows in which a plurality of nozzles for ejecting ink are arranged at a predetermined interval in an intersecting direction intersecting the transporting direction, wherein the plurality of nozzle rows are arranged parallel to each other, one end side in the intersecting direction in a particular nozzle row and the other end side in the intersecting direction in another nozzle row are overlapped with each other in the transporting direction so as to form an overlap area, and in the overlap area, the nozzle in the particular nozzle row and the nozzle in the other nozzle row are at different positions in the intersecting direction; and determining an ink ejection method from the nozzles in the overlap area, based on a density of the image.

This invention relates to suppression of density unevenness caused by occurrence of ink-landing position shifts between print scans. In an embodiment, upon printing by scanning an inkjet printhead including printing elements, the following control is executed. That is, in order to form an image by print scans of the printhead on a single print area on a print medium, image data are acquired in correspondence with the respective scans. Also, the printing elements are partitioned into plural groups each including continuously arrayed printing elements, and the printing elements in each of the plural groups are time-divisionally driven based on drive sequences. Then, the drive sequences upon time-divisional driving in respective scans are set to include elements having the same drive timings and those having different drive timings.

The invention realizes a uniform toner coating on a developing roller, thereby preventing a density unevenness and a toner dripping and suppressing a developing roller set mark image in a contact developing method, by conditions that the DC voltage applied to the developer regulating member is the same as the DC voltage applied to the developer carrying member or at a side of a charging polarity of the developer with respect to the DC voltage applied to the developer carrying member; and a frequency f (Hz) and a peak electric field strength E (V / m) of the AC electric field formed by the AC voltage between the developer regulating member and the developer carrying member, and a peripheral speed v (m / s) of the image bearing member satisfy conditions:4.2×v≦f≦2500 and2.2×106≦E≦5.2×106.

An image forming apparatus has an image bearing member on which a toner image is to be formed. A transfer roller contacts a surface of the image bearing member for transferring a toner image on the image bearing member to one side of a transfer medium by applying a voltage having a polarity opposite to that of the toner image on the image bearing member from the other side of the transfer medium. A biasing member biases the transfer roller toward the image bearing member. The transfer roller is shaped such that the outer diameter of a first part corresponding to the width of a specified sheet size is constant and the outer diameters of second parts located closer to opposite ends of the transfer roller than the first part are gradually increased toward the outer sides in an axial direction.

There is provided an ink jet printer including a carriage, and an ink jet head. The ink jet head has two first nozzle groups to jet a first ink, two second nozzle groups to jet a second ink, and two third nozzle groups to jet the second ink. Each of the first, second and third nozzle groups includes a plurality of nozzles arrayed at a pitch P along a second direction. The second nozzle groups accord respectively with the first nozzle groups in terms of nozzle position in the second direction, the third nozzle groups are dislocated respectively from the second nozzle groups in terms of nozzle position in the second direction, and any two groups selected from the first and second nozzle groups are arranged respectively on two opposite sides of each of the third nozzle groups in the first direction.

An ink jet printing apparatus and an ink jet printing method are provided which use a printing head having a plurality of ejection opening arrays and enable high quality printing without causing uneven density in a conveying direction. For this purpose, by providing a plurality of ejection opening arrays to chips constituting the printing head and changing data assigning ratio of each ejection opening array, deviation in impact positions depending on the distance between the ejection opening arrays becomes inconspicuous.