Abstract: In a printing apparatus which performs printing by scanning a printhead having printing elements arrayed in a predetermined direction on a printing medium in a direction crossing to the array direction on the basis of information transmitted from a host apparatus, stores print data transmitted from the host apparatus, and has a buffer smaller in capacity than a print data amount printed on the printing medium by one scanning of the printhead, the buffer is divided into a plurality of blocks corresponding to rectangular regions printed by scanning. The use order of the blocks is so managed as to circularly store print data in the blocks along with the progress of printing. When print data representing non-driving of the printing elements successively exist in a predetermined amount, the predetermined amount of print data is represented by specific control data without storing the predetermined amount of print data in the blocks.

Abstract: The object of this invention is to provide a printing apparatus and printhead temperature retaining control method capable of suppressing power consumption, and reducing degradation in image quality. To achieve the object, a printing apparatus for printing an image on a printing medium by discharging ink, executes the following processes. A first temperature adjustment process is executed to adjust the printhead temperature to a first adjustment temperature during the non-printing period in which preparation for printing the image is executed by discharging ink from the orifices. Additionally, a second temperature adjustment process is executed to adjust the printhead temperature to a second adjustment temperature during a printing period in which the image is printed on the printing medium by discharging ink from the orifices. The process is executed while providing a quiescent period without printhead temperature adjustment between the first and second temperature adjustment processes.

Abstract: 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.

Abstract: The present invention provides an ink jet printing apparatus that can print high-quality images even if a print head with smaller nozzles is used, by efficiently stabilizing the ink ejection state of the print head without increasing the running costs of the printing apparatus. A cap that can be used to cap the print head includes a hole through which ink inside the cap is discharged and which can be sealed so as to retain the ink in the cap.

Abstract: To provide an ink jet printing apparatus and ink jet printing method capable of printing at high speed and high image quality in accordance with the distance between the head and the paper. In performing a first print mode for printing to a unit region of the print medium by making the print head scan N times (N: positive integer), and executing a second print mode for printing to the unit region of the print medium by making the print head scan M times (M: positive integer, M>N), the distance between the print head and the print medium (distance between the head and the paper) in the first print mode is made shorter than that in the second print mode.

Abstract: An image forming system includes: a computer for supplying image data; and a printer having a sub-tank for retaining ink to be supplied to a printing head and a system performing an on-demand supply of ink to the sub-tank. With the image forming system, during printing, the occurrence of a fuzzy image, due to ink in the sub-tank being exhausted, is prevented, and a reduction in the throughput of printing is also prevented. The computer counts, in advance, dots required for the printing of image data, and transmits the dot count, as well as image data, to the printer. The printer compares the amount of ink in the sub-tank with the required ink amount that based on the received dot counts. Only when it is determined that the remaining ink amount is insufficient, refilling of the sub-tank is performed, and thereafter, the printing of the image data is performed.

Abstract: A printer having storing means storing time information indicating the time at which cleaning operations were last performed, with the initial value of time information stored in the storing means being set to a time later than the shipment of the printer. Elapsed time between the time information stored in the storing means and the current time is calculated when a user gives the printer an instruction to start printing operations. The printer performs suitable cleaning operation for a case wherein the calculated value of the elapsed time is negative.

Abstract: When a printing position is displaced by an inclination of a printing head, for example, the displacement can be corrected in an easy and effective manner and a user can easily recognize the displacement of the printing position to correct the displacement. To realize this, dots for forming a test pattern are formed by different scannings by a nozzle group including a plurality of nozzles positioned at one end side of a nozzle row and a nozzle group including a plurality of nozzles positioned at the other end side of the nozzle row. Depending on displacements of the printing positions of these dots, the plurality of nozzles constituting the nozzle row are divided into a plurality of divided nozzle groups. Then, the printing position is adjusted on the basis of the divided nozzle groups.

Abstract: In an image processing apparatus, a data amount of printing data generated for each different size of dot is reduced. Specifically, in quantization to obtain data for each printing head, printing data for a large dot is set as data in which a bit number per pixel is two bits, and printing data for a medium or small dot is set as data in which a bit number per pixel is one bit. Thereby, a data amount per pixel can be reduced compared with data in which all bit numbers per pixel for the large, medium and small dots are equally two bits.

Abstract: In an image printing apparatus for printing an image by combining dots of a plurality of sizes, a banding problem attributable to variations in conveying operation, and a temperature rise of a print head with an increase of the number of ejections are solved with a relatively simple configuration. To this end, a combination of dots of a plurality of sizes is assigned to each of pixels expressed at a plurality level of density. In this assignment, a dot larger than a pitch of an image resolution is preferentially allocated to a pixel having a density level higher than that to which one dot smaller than the pitch of the image resolution is allocated.

Abstract: When bidirectional multi-pass printing is carried out by use of a printing head having an inclination, even if a bidirectional printing is somewhat displaced, an inclination of a printing position is corrected in a state where “band unevenness” is suppressed as much as possible. In order to realize the correction described above, a division number B for dividing a plurality of printing elements into a plurality of blocks, and a timing at which each of the blocks is driven, are set on the bases of inclination information on the printing head and the number of multi-passes. Thus, even if the bidirectional printing is displaced, printing widths are equally increased or reduced in the respective regions. Consequently, it is made possible to avoid the “band unevenness” which is caused by differences in the printing width among the regions.

Abstract: A printing apparatus performs printing by scanning a printhead having an array of printing elements in which a plurality of printing elements are arranged in a predetermined direction, over a printing medium according to control information and image data transmitted from a host apparatus. Setting information designating some of the printing elements to be used for printing in the printing elements in the printhead according to a predetermined printing parameter is transmitted as control information from the host apparatus to the printing apparatus in the printing apparatus, the printing elements to be used are set according to the setting information. Data to be printed by the printing elements used for printing in correspondence with scanning is generated in the host apparatus and transmitted as image data from the host. The printing apparatus performs printing by driving the set printing elements according to the image data during scanning.

Abstract: An inkjet recording apparatus includes a recording head having a nozzle array of plural nozzles capable of discharging ink. The inkjet recording apparatus performs a scanning/recording operation for forming an image on a recording medium by shifting the recording head in a main scanning direction. The inkjet recording apparatus repeatedly perform the scanning/recording operation and a recording medium conveying operation. The inkjet recording apparatus sets a recording position correction amount for each section of the nozzle array based on information relating to the inclination, so that a recording position correction amount in a forward scanning operation is different from a recording position correction amount in a backward scanning operation.

Abstract: The present invention provides an ink jet printing apparatus and a method for controlling temperature for the ink jet printing apparatus wherein the temperature of a print head, which may lower during printing, is controlled before printing without using any sub-heater to allow a favorable ejection condition to be established without reducing the head temperature below a predetermined value. Thus, scan width information and dot count information are acquired before a carriage starts scanning to determine the heating temperature of the print head on the basis of the information.

Abstract: The present invention provides an ink jet print head that allows for a fast printing of high-density, high-quality images without increasing cost and size of the print head. To this end, the ink jet print head has orifices for ejecting ink of a first volume and orifices for ejecting ink of a second volume, the second volume being smaller than the first volume. Further, the number of orifices for first-volume ink per unit length is greater than the number of orifices for second-volume ink per unit length.

Abstract: A CPU generates a mask pattern by generating patterns corresponding to a predetermined number of times in the sub-scanning direction in accordance with the number of printing elements of a printhead which corresponds to the amount by which scanning is performed once in the sub-scanning direction, and repeating this operation by the number of times corresponding to a predetermined number of columns. The generated mask pattern is stored in an RAM. An image is then printed by using image data and the mask pattern stored in the RAM for each printing timing signal in the main scanning direction.

Abstract: An ink jet printing apparatus and a print position adjusting method capable of easily adjusting a relative print position between nozzle lines are provided. Images are printed on a print medium in a drive mode A and a drive mode B by using a print head which has first and second nozzle groups, each including a plurality of ink ejection nozzle lines. In the drive mode A, only one of the first and second nozzle groups is driven during one scan of the print head. In the drive mode B, the first and second nozzle groups are driven at different timings during one scan of the print head. A print position adjust value for adjusting a relative print position between the nozzle lines in the drive mode A is retrieved. Depending on whether the print position adjust value is even or odd, a print position correction value for the first nozzle group and a print position correction value for the second nozzle group are determined.

Abstract: Image deterioration is suppressed as much as possible which is complexly generated by variations of printing positions respectively of printing elements in a printing element row and by displacement of printing positions among printing element rows. To this end, a first adjustment value for adjusting printing positions among a plurality of printing elements included in a printing element row is obtained. Next, printing positions among a plurality of printing elements are adjusted based on the first adjustment value. Then a second adjustment value for adjusting printing positions among not less than two of the printing element rows is obtained. Thereby variations of printing positions in a discharge port row and displacement of printing positions among discharge port rows are properly adjusted in different phases, and adverse effects generated by two kinds of different causes are collectively suppressed.

Abstract: When conveying tables for conveying the printing medium are selected to perform interlace printing, the occurrence of unevenness in an image which results from switching of the tables is prevented. It is determined whether a phase of the conveying table is a transfer inhibition phase in transfer to a printing area. In the case of the transfer inhibition phase, the switching is not made to a new table, but the previously used table is used. Thus, the switching can be made to a conveying table so as not to make a shift amount +1/2N or ?1/N continue. Consequently, it is possible to prevent the occurrence of unevenness in an image which is caused by 1/N deviation of a printing position in a sub-scanning direction with regard to print data at the time of transfer from a rear end area to the normal area or the normal area to the rear end area.

Abstract: An inkjet printing apparatus prints by scanning an inkjet printhead for discharging ink and a printing medium relative to each other. The printhead includes a first nozzle group used to print a dot having a first density, and a second nozzle group used to print a dot having a second density. The inkjet printing apparatus has a first printing mode in which only one of the first and second nozzle groups is used during one printing scan, and a second printing mode in which the first and second nozzle groups are driven at different timings during one printing scan. In this inkjet printing apparatus, a pattern for adjusting the relative printing positions of the nozzle rows in the first printing mode is printed. From this pattern, set values of relative printing positions in the first printing mode are specified. On the basis of the specified set values, set values of the relative printing positions of the nozzle rows in the second printing mode are determined.