88results about How to "Reduce density unevenness" patented technology

Each embodiment relates to an image display device which comprises an image display panel, in which two or more groups of particles having different colors and different charge characteristics are sealed between two substrates, at least one of two substrates being transparent, and, in which the particles, to which an electrostatic field produced by a pair of electrodes provided on one or both substrates is applied, are made to fly and move so as to display an image. Among them, in the first aspect of the invention, an image forming process for forming the image by applying an electric field pattern between the electrodes, the electric field pattern serving to fly particles A to the substrate at an image display side; and an image forming process for forming the image by applying an inversion (negative) electric field pattern with respect to the electric field pattern, the inversion electric field pattern serving to fly particles B having different colors and different charge characteristics with respect to those of the particles A to the substrate at an image display side; so that an image deleting process prior to forming the image to be displayed is eliminated.

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.

An image quality detecting apparatus detects image quality based on a specified image pattern formed on an image carrier. This apparatus includes a light-emitting device that radiates a spotlight on the image carrier, a lens, a scanning unit that scans the image pattern with the spotlight, and a photoelectric conversion element that detects a quantity of light reflected from the image pattern and the image carrier or light transmitted through the image pattern and the image carrier during the scanning. The image quality is detected by setting a diameter of the spotlight at least in a scanning direction to the reciprocal number of a spatial frequency or smaller in which human eyesight is the most sensitive, for example, to 1000 μm or less.

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.

An image recording apparatus includes: a recording head having a plurality of recording elements; a conveying device which conveys at least one of the recording head and a recording medium to cause relative movement between the recording head and the recording medium; a density information acquisition device which acquires output density data indicating a recording density of each of the plurality of recording elements; a characteristic computation device which obtains recording information of each of the plurality of recording elements from the output density data acquired by the density information acquisition device; a characteristic storage device which stores characteristic information in an appropriate state of the plurality of recording elements that is set in advance; a comparison device which compares, for each recording element that is able to perform recording on the recording medium, the recording information with the characteristic information stored in the characteristic storage device; a density correction value calculation device which calculates, for each of the plurality of recording elements, a correction value for recording control according to a comparison result of the recording information and the characteristic information obtained by the comparison device; a density correction value modification device which performs modification of the correction value for recording control of a peripheral recording element that performs recording on a periphery of a recording position on the recording medium performed by a detected recording element, from among the plurality of recording elements, for which the recording information is determined to fulfill a predetermined condition with respect to the characteristic information according to the comparison result, the modification being performed according to the characteristic information and the recording information of the detected recording element so as to compensate the recording density of the detected recording element; and an image correction device which performs, for each of the plurality of recording elements, correction of data of an image outputted by the plurality of recording elements onto the recording medium, according to the correction value calculated by the density correction value calculation device and the correction value modified by the density correction value modification device.

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 image reading device has an image processor that generates correction data to be used for shading correction and performs the shading correction using the correction data. The image processor generates intermediate data with a predetermined density level, generates intermediate data in different positions in the sub-scanning direction based on image signals of a first reference plate and a second reference plate disposed in the different positions, generates first and second black correction data based on the respective intermediate data, generates black correction data according to the sub-scanning direction based on both the black correction data, and performs the shading correction using the black correction data in the respective positions in the sub-scanning direction.

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.

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.

Density unevenness is suppressed even in an image that is formed by a multiple exposures method in which the same region on a photoreceptor is exposed multiple times with different laser light sources (light emitting elements), by adjusting the amounts of light of the respective lasers based on a density difference among test images. An image is formed for each group of light emitting elements grouped together for multiple exposures by dividing, in the main scanning direction, the region of a test image formed on a recording medium. The images formed for the respective multiple-exposure light emitting element groups are compared to one another in density, to thereby adjust the amounts of light of the respective laser light sources (light emitting elements) and reduce fluctuations in image density.

The object of the invention is to settle a phenomenon that a quantity of jetted ink increases at the end of an image and a density increases in a share-mode ink jet head. In a three-split driven head, a first group prints so that a diameter of a dot is reduced by reducing the quantity of jetted ink as dots at both ends, a second group similarly prints, and a third group also similarly prints. Since each three dots at both ends in a main scanning direction of an acquired image are smaller than dots in the middle, a phenomenon that a quantity of jetted ink increases at the end of the image and density increases is reduced.

An image reading apparatus includes: a sensor module which includes a light source and sensors; a reference member for creating black correction data and white correction data; and an image processor. The image processor corrects uneven density of an image resulting from interference of image signals from the sensors, by performing, on the image signals obtained by the sensors, shading correction using black correction data and white correction data. The image processor obtains causes the sensors to obtain image signals of the reference member, and creates the white correction data based on white data, and the black correction data based on intermediate data. At least one of when creating the white correction data and when creating the black correction data, the image processor causes the sensors to obtain image signals of the reference member a plurality of times.

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.