Abstract: For eliminating waste of ink and achieving high charging efficiency with a reduced charging time where a printing head is equipped with a second tank for reserving a predetermined amount of ink and a supply system is configured to supply ink from a first tank to the second tank intermittently, the second tank is provided with a variable internal volume. The internal volume is varied to cause the second tank itself to function as an actuator for charging ink and performing a venting process. Specifically, the internal volume is forcibly reduced to cause a reverse flow of a gas residing in the second tank along with ink into the first tank, which makes it possible to generate of waste ink that is released to the outside. A normal charging operation can be completed simply by causing a change in the opposite direction (the direction of increasing the internal volume). Relatedly, the second tank may be provided with a member for holding ink and generating a negative pressure originating from an elastic force.

Abstract: An ink jet recording apparatus for effecting recording on a recording material by ejecting ink through a plurality of ejection outlets in units of band with relative scanning movement between a recording head and the recording material, the ink jet recording apparatus, includes obtaining means for obtaining scanning interval information relating to time period required for recording a connecting portion between a band of a certain scan of the recording head and a band of the next scan of the recording head; and reducing means for reducing an amount of the ink shot to a neighborhood of the connecting portion on the basis of the scanning interval information obtained by the obtaining means.

Abstract: In a recording apparatus for effecting recording with a recording head on a recording medium, a temperature detector provided on a control circuit board of the recording apparatus detects a temperature at the board, and a timer measures a first activation time of electric power supply to the control circuit board for a control not involving a recording operation. The timing of reading the temperature detected by the temperature detector, as well as a correction value for the thus read value, are determined according to the first activation time measured by the timer.

Abstract: There is provided an inkjet printing head carrying a sub-tank from which accumulated gases can be easily discharged. The inkjet printing head includes a sub-tank which has a movable section constituted by a deformable film sheet, a spring for generating a negative pressure, and a supply/discharge channel for supplying ink and discharging accumulated gases. The sub-tank is intermittently supplied with ink from a main tank and reserving the ink. The supply/discharge channel is provided in a position where it does not interfere with the movable section and the spring, e.g., in a frame of the sub-tank. The supply/discharge channel is preferably formed in an upper part of the sub-tank, e.g., a ceiling section of the sub-tank.

Abstract: In a printing apparatus a printing medium is fed such that before a paper sensor detects a trailing edge of a preceding printing medium, a paper feeding roller begins the feeding of a succeeding printing medium, and after the paper sensor detects the trailing edge of the preceding printing medium, a leading edge of the succeeding printing medium arrives at the location of the paper sensor. Thus, the feeding of printing paper is performed rapidly and consequently the printing apparatus can perform recording rapidly.

Abstract: An inkjet recording apparatus suppresses defective ejection while reducing a consumed ink amount. In the apparatus, a cap-open period, during which a cap member does not cap ejection ports of a recording head of the apparatus, is measured, and a recovery operation executed by a recovery unit is controlled based on a cumulated cap-open period. With the above arrangement, there can be solved a problem that the ink ejecting state of the recording head is deteriorated depending on a recording operation because a cap-open state, in which the cap member does not cap the ejection ports of the recording head, continues while the inkjet recording apparatus executes the recording operation, thereby the reliability of the inkjet recording apparatus can be improved.

Abstract: A printing apparatus and a preliminary discharge control method capable of efficient preliminary discharge control even in a case where a time interval to assure normal printing is equal or nearly equal to the period of one print scanning of an inkjet printhead. In the method, in an inkjet printhead which performs printing by discharging ink from plural print elements while reciprocate-scanned by a carriage, the number of ink dischargings from each of the plural print elements is counted during print scanning by reciprocate scanning. It is determined whether or not the counted number of ink dischargings from each of the plural print elements is equal to or greater than a predetermined number at predetermined intervals. In accordance with the result of determination, a printable period is updated, and the updated printable period is compared with time necessary for the next print scanning upon completion of one print scanning by reciprocate scanning.

Abstract: A print apparatus that, without significantly reducing an overall printing speed, allows a reduction in uneven densities due to the discharge time difference between black ink and color inks, which occur particularly at both ends in a scanning range and which are caused by the printing by bidirectional scanning of print heads, and enables high image-quality printing to be realized. In this print apparatus, one band is divided into plural areas in a main scanning direction, the dot numbers of black ink and color ink imparted to respective areas are counted. If there are any areas where the dot numbers of both black and color exceed respective threshold values, the area number is counted, and if the number exceeds a predetermined number, the print mode is switched from bidirectional printing to a unidirectional one, upon determining that there is a high probability of occurrence of the above-described uneven densities.

Abstract: An ink jet recording apparatus comprises an ink jet recording head with a plurality of recording elements for generating energy for discharging ink, a plurality of ink flow paths, a plurality of ink discharge ports for discharging ink, and a plurality of recording element substrates, and a cap member for capping the discharge ports. The plurality of recording element substrates, the thickness of one being different from that of the others, are arranged adjacent to each other on a substantially even flat plane, and the cap member is made capable of capping the discharge ports of the plurality of recording element bases plates altogether on the substantially even flat plane.

Abstract: In a structure which includes a second tank for reserving a predetermined amount of ink to be supplied to a printing head and in which a supply system is configured such that ink is intermittently supplied to the second tank from a first tank, a high charging efficiency to and shortened processing time for charging the second tank, and high overall usability of ink are achieved. In an orientation upon using the printing apparatus, a port of a channel located at the second tank side for supplying ink from the first tank to the second tank is arranged relatively high position and an outlet port for supplying ink from the second tank to the head is arranged relatively low position in relation to the direction of gravity, and a port of the channel located at the first tank side is arranged at the bottom of the first tank.

Abstract: Images are printed with a reduced extent of a joint streak regardless of the type of a printing medium or the number of printing passes and a printing speed is increased without executing an unwanted thinning for correcting the joint streak. More specifically, printing method information added to print data is obtained, and it is determined on the basis of this information whether or not to execute a thinning process. Consequently, inter-band data correction process based on the thinning can be executed depending on the type of the print medium and the number of printing passes, thereby achieving an appropriate thinning depending on the type of the print medium or the like. When the thinning is not to be executed, all the processes related to the thinning can be omitted to prevent a decrease in printing speed.

Abstract: Two print heads combined for each ink color are arranged symmetric to each other with respect to the scan direction and are used for a bidirectional printing. In producing secondary colors, image data is spread-processed by using a “diagonal arrangement” spread pattern to differentiate the ink application order at one of dots arranged in the raster direction from those of the other dots and thereby reduce color variations in the scan direction. Further, when image data has a half-tone, a “horizontal arrangement” spread pattern, different from the previous one, is used to perform image processing on the image data to alleviate an undesired texture. To prevent a driving load from concentrating on only one of the paired print heads, the number of times that each nozzle is driven is counted and an adjustment is made to spread the frequency of use among the two paired print heads.

Abstract: A liquid ejection head according to the present invention includes a single liquid supplying port to which a liquid is supplied, a plurality of liquid supplying passages having one end in communication with the liquid supplying port, a plurality of common liquid chambers that are in communication with the other ends of the liquid supplying passages, respectively, and a plurality of ejection port groups which are in communication with the common liquid chambers via liquid channels and from which liquid droplets are ejected. A cross sectional area or length of the liquid supplying passage in communication with the ejection port group having a larger sum of opening areas of the ejection ports is set smaller than that of the liquid supplying passage that is in communication with the ejection port group having a smaller sum of opening areas of the ejection ports.

Abstract: It is an object of this invention to provide a ternary or higher-order quantization method which avoids close gathering of pixels at a first output level. First and second threshold values Lth1 and Lth2 for ternarization and output values 0 (blank), 1, and 2 as converted output values are set to have a relationship of output value of 0 (blank)<first threshold value Lth1<second threshold value Lth2<output value of 1<output value of 2. This prevents a quantization error from becoming 0 when an input pixel value is an intermediate value, and prevents continuous outputting of only pixels having the output value of 1. When this image is printed, small ink dots corresponding to the output value of 1 are not easily continuously printed. This improves the image quality.

Abstract: Disclosed are an image processing apparatus and method for the purpose of preventing overlapping of dots between two colors in low-density areas in color pseudo-grayscale processing, thereby obtaining excellent placement of the dots of each color. When a color image is binarized, an error is added to a respective one of color components (I0,I1), after which output decision means (2) decides an output value in accordance with the value of the sum in such a manner that the sum of pixel values after conversion will be rendered constant. Error calculation means (3-0, 3-1) calculate differences between pixel values before and after binarization as errors, and error diffusion means (9-0, 9-1) calculate values to be diffused to a neighboring pixel. Weighting coefficients used at such time are decided in accordance with combinations of values of the color components (I0,I1) of pixel values in the original image. The output value decided by the output decision means (2) is printed out by a printer or the like.

Abstract: An ink jet recording apparatus, for effecting recording on a recording material by ejecting a plurality of inks with relative scanning movement between a recording head and the recording material, includes an obtaining unit for obtaining relative information indicative of a relative relation between the amounts of inks to be ejected for each of unit areas provided by dividing an area in the neighborhood of a boundary between adjacent bands of scanning recording of the recording head across the recording material; a determining unit for determining, for each of the inks, a reduction rate at which the amount of the ink to be ejected to the neighborhood of the boundary in the unit area on the basis of the relative information for each of the unit areas obtained by the obtaining unit and on the basis of quantity information indicative of an amount of each into be ejected in the unit area; and a reducing unit for reducing the amount of each ink to be ejected to the neighborhood of the boundary on the basis of the

Abstract: To reduce the number of simultaneously driven printing elements so that the instantaneously flowing current is restricted in a printing system for completing an image by repeating the printing scan a plurality of times in the same printing area while applying random mask thereto. For this purpose, a mask of a predetermined size is structured as a thinning pattern in which data are arranged randomly, the data being for determining whether or not the respective ink ejection openings in a printing head are to be driven when the printing head repeats the scan a plurality of times in the same printing area of a printing medium. When forming an image, the printing elements concerned with the printing operation in the same printing area are divided into a plurality of sections, and the thinning patterns complementary to each other are applied to the respective sections during the respective printing scans.

Abstract: In an ink jet print head used in a serial type ink jet printing apparatus according the present invention, a portion of the nozzle column is given a wider nozzle-to-nozzle interval than those of other portions of the nozzle column so that the width in the line feed direction of each image area printed in a single printing scan by the ink jet print head is longer than a distance that a print medium is moved by one line feed. In this serial print head, the width of each image area printed by a single printing scan can be made a predetermined amount longer than the line feed distance at all times. As a result, the adjoining image areas printed by separate printing scans overlap each other at their boundary portions by a predetermined amount.

Abstract: An ink jet printing apparatus is provided which can prevent a discharged paper-induced smear efficiently with a simple construction. To achieve this objective, the ink jet printing apparatus of this invention determines, based on an amount of ink ejected per unit area onto a preceding print medium last discharged to the discharge position by the discharging section, a required time duration that needs to elapse before a subsequent print medium being discharged toward the discharge position is allowed to contact a predetermined area of the preceding print medium and then controls a printing speed on the subsequent print medium so that the subsequent print medium will not contact the predetermined area of the preceding print medium within the time duration determined.

Abstract: In a supply system which includes an ink container for reserving a predetermined amount of ink to be supplied to a printing head and which is configured such that ink is intermittently supplied to the container from an ink tank, there is provided a structure that fundamentally eliminates waste of ink associated with an operation of charging the container to apply a required negative pressure to the head. An ink containing body in which a negative pressure can be generated because of its elasticity is provided in the container. After the ink containing body is expanded to introduce ink into the same by depressurizing the interior of the container, the interior of the container is pressurized to contract the ink containing body, thereby returning a predetermined amount of ink to the tank. A negative pressure is thus generated in equilibrium with an ink meniscus holding ability of the head.