87results about How to "Reduce density unevenness" patented technology

To suppress curling phenomenon of a recording medium to which a liquid composition is applied while securing ejection stability. A liquid composition for used in an image recording method including the steps of applying an ink containing a colorant in a dissolved state or a dispersed state to a recording medium and applying to the recording medium a liquid composition which destabilizes the dissolved state or the dispersed state of the colorant in the ink by coming into contact with the ink, the liquid composition including at least a polyvalent metal ion, water, and water-soluble organic compounds 1 and 2, in which a content X (mass %) of the water-soluble organic compound 1 in the liquid composition is 15 mass % or more, and the content X (mass %) of the water-soluble organic compound 1 in the liquid composition and a content Y (mass %) of the water-soluble organic compound 2 in the liquid composition satisfy a specific relationship.

An image forming apparatus including an image carrying member, a transfer member, support rollers, a detecting mechanism, and a controller. The image carrying member forms a toner image on its surface facing a surface of the transfer member, supported by the support rollers, which transfers the toner image to a recording medium. The detecting mechanism includes a detection roller, a roller shaft, a moving member, and a sensor, and detects a speed of the transfer member. The detection roller includes one support roller selected from the support rollers, and is provided with the roller shaft. The moving member is directly fixed to the roller shaft and rotates with the detection roller. The sensor detects a moving speed of the detection roller with the moving member. The controller controls a traveling speed of the transfer member to a target speed based on a detection result of the sensor.

Provided are an inkjet recording device and an inkjet recording method for providing an image wherein concentration nonunifomiity is reduced with less ink bleed between inks of different colors, in high speed multicolor printing of single path system. In the device and the method, a conditional expression of 0.6≦R/R0≦0.9 is satisfied, where, R is a dot radius of a second ink jetted on a first ink which is jetted on the recording medium and semi-cured by a beam applied, and R0 is a dot radius of the second ink directly jetted on the recording medium.

An object of the present invention is to provide an apparatus and method for ink jet printing which can reduce density unevenness caused by an end deviation condition associated with ink droplets ejected from a print head, regardless of gray scale of a printed image. The present invention thus sets the print duty for a nozzle located at an end of a nozzle array formed in a print head on the basis of the end deviation amount of a position impacted by an ink droplet ejected from the end of the nozzle array.

In an inkjet printing apparatus, uneven density is reduced while suppressing a landing position deviation caused by a difference of head-to-medium distances in a printing medium conveying direction. Specifically, predetermined patterns for detecting a difference of the head-to-medium distances are printed. Reading of the patterns is performed and then a detection of a difference between the head-to-medium distances is performed based on the reading result. Then, adjustment of the head-to-medium distance is performed based on the difference between the head-to-medium distances detected. Specifically, the respective head-to-medium distances at the upstream side ejection port and the downstream side ejection port are made equal by changing an attitude of the print head.

In performing multi-pass printing by using a printhead having a plurality of nozzles, a print data setting unit sets a printing amount for each nozzle for each main scan of the printhead based on a print data setting LUT. This print data setting LUT reflects the information of the number of passes and the number of nozzles to be used which are arbitrarily set. A halftoning unit generates a dot pattern as a formation target by performing binarization processing for the print amounts set in this manner.

Density unevenness accompanying a variation in an ejection characteristic of each nozzle is reduced without worsening granularity of an image. To this end, an image processing apparatus generates first corrected data by correcting image data by using a first correction table common to the plurality of nozzles. Further, the image processing apparatus generates second corrected data by correcting the image data by using a second correction table for each of the plurality of nozzles. Furthermore, the image processing apparatus generates first quantized data by quantizing the first corrected data and generates second quantized data by quantizing the second corrected data. After that, the image processing apparatus generates N-valued print data based on the first quantized data and the second quantized data.

An objective of this invention is to suppress an increase in power consumption and reduce ink density unevenness caused by variations in the amount of ink discharge upon performing printhead temperature retaining control. To achieve this objective, a printing apparatus according to the invention which prints on a print medium by scanning a printhead with a printing element for generating thermal energy has the following arrangement. That is, the printing apparatus includes a determination unit which predicts a maximum temperature which the printhead reaches in printing, and determines a target temperature based on the predicted maximum temperature, and an adjustment unit which adjusts the temperature of the printhead in printing to the target temperature.

Provided is an inkjet printing apparatus for performing a printing with a first nozzle array for ejecting a first color ink and a second nozzle array for ejecting a second color ink. The apparatus reduces density unevenness stemming from a sudden error in conveyance of a printing medium. When the apparatus performs a scan with respect to the printing medium for printing in which using ranges of nozzles in the first and second nozzle arrays are restricted to parts thereof, the restricted using ranges of the first and second nozzle arrays are shifted from each other. Thereby, the density unevenness stemming from the error in conveyance occur in positions which are different between the first and second colors, Thus, it possible to make the overall density unevenness less obvious by making gradients of variations in brightness and chroma of an image smaller.

An optical scanning apparatus and a color image forming apparatus using the same, in which streak-shaped density unevenness is reduced to prevent image deterioration: each of scanning surfaces is simultaneously scanned with light beams emitted from light source units and scanning lines are simultaneously drawn on the scanning surfaces; the light beams emitted from at least four light emitting portions of the corresponding light source unit are simultaneously deflected for scanning by a deflecting unit; and image data corresponding to a first scanning line, i.e. a scanning line located on an uppermost stream side in a direction in which the scanning surfaces move among scanning lines, on at least one of the scanning surfaces in a k-th scanning by the deflecting unit is displaced by at least one line space from image data corresponding to a first scanning line on another scanning surface in the k-th scanning.

An inkjet printing apparatus, which ejects ink from a printing head to print, is provided for reducing an ejection amount increase caused by a temperature increase of the printing head due to ink ejection in the case of high speed printing, thereby suppressing density unevenness which occurs in a printing area in the main scanning direction due to the ejection amount increase. A scanning region of the printing head is divided into a plurality of count areas provided for counting the number of times of ink ejection based on image data and the count is carried out for each of the plurality of the counting areas. The scanning region of the printing head is divided into a plurality of printing areas provided for correcting the image data in response to the count value to print the image data and the correction of the image data is carried out for each of the plurality of the printing areas. In this way, the count of image data and their correction are carried out in one main scanning region.

When executing the gradation lowering processing to a data area in the lower side in multi-valued print data 403, an error generated by executing the gradation lowering processing to the data area in the lower side is stored in an information storage area 901B. On the other hand, the error thus distributed and stored is used for executing the gradation lowering processing to the data area “J” (Jth line) in multi-valued print data 404 relating to the next scan. In this way the error generated when executing the gradation lowering processing to the multi-valued print data is stored, which is used at the time of executing the gradation lowering processing to the multi-valued print data relating to the next scan. Therefore, the density is stored by receiving and delivering the error between the multi-valued print data in a scan unit.