Abstract: A method for controlling printing speed of print jobs having different printing images on printing material, includes calculating printing data from a first static component, calculating and combining printing data from first variable components with printing data from the first static component forming first printing data and forwarding the first printing data to a printing unit, counting a current value with a counter, calculating printing data from a second static component, printing first printing images with the printing unit using first printing data and controlling printing speed of the printing unit to conclude the calculation before the counter reaches a value, calculating and combining printing data from the second variable components with printing data from the second static component forming second printing data and forwarding second printing data to the printing unit, and printing the second printing images with the printing unit using second printing data.

Abstract: A target pixel is processed according to a blended combination of two or more error diffusion techniques. For example, the two or more techniques may include a standard error diffusion technique and rank ordered error diffusion. Additionally, or alternatively, a quantization resolution is selected for the target pixel based on information regarding the pixel. For example, a quantization resolution is selected based on a relative position of the target pixel or based on a value of the target pixel and/or values of pixels neighboring the target pixel.

Abstract: When printing is performed by dividing a thermal printer head into segmented blocks, the number of dots to be printed in one line is changed, depending on the case, high-speed printing with a small division number of the segmented blocks, or low-speed printing with a large division number of the segmented blocks. When the division number of the segmented blocks is large and printing is performed at a low speed, paper feeding within one line is performed by multiple pitches to prevent the paper sheet from halting in one line, and energization is performed for each pitch to prevent occurrence of gaps between dots and between lines, by increasing the number of dots to be printed in one line. In the multiple pitches in one line, the ratio of energization amount to be fed in each pitch is changed to reduce a difference in density among pitches in one line.

Abstract: A driver circuit of a thermal print head is disclosed including: a plurality of gating groups respectively coupled to a plurality of strobe signals of different timings in which each gating group includes a plurality of gate units respectively coupled to a plurality of heating elements; and a register module coupled to the plurality of gating groups for providing each gate unit with a corresponding color level data; wherein each gate unit controls a coupled heating element according to a corresponding strobe signal and a received color level data.

Abstract: A method of driving a print head and an image forming apparatus employing the same are provided, wherein recording elements of the print head are divided into n groups and are driven to print an image on a medium, wherein recording elements from the respective n groups, that is, one recording element from each of the n groups, are simultaneously driven and a driving order of the recording elements is arranged such that printing positions of the recording elements in each group form a plurality of oblique lines as a medium is fed. Accordingly, the plurality of recording elements, which are divided into a plurality of phases, are non-sequentially driven and therefore, the power consumption due to the driving of the recording elements and degradation of print quality can be reduced.

Abstract: A method of controlling a temperature of a print chip of a printhead in an ink jet printer includes providing a memory device within the printer. Ink is emitted from the printhead. Temperature data associated with the print chip during the emitting step is recorded. A thermal resistance value associated with the printhead and/or a thermal capacitance value associated with the printhead is calculated. The calculating is dependent upon the recorded temperature data. The thermal resistance value associated with the printhead and/or the thermal capacitance value associated with the printhead is stored in the memory device. A temperature of the print chip at a future point in time is estimated based upon a number of ink drops to be emitted by the printhead before the future point in time, and the thermal resistance value associated with the printhead and/or the thermal capacitance value associated with the printhead.

Abstract: A thermal line printer drive method and a thermal line printer devised to prevent occurrence of a white gap during printing. A plurality of heating elements arranged on a line perpendicular to a sheet feed direction are separated into a plurality of blocks, and the heating elements in each block are driven separately from those in other blocks to perform thermal recording on a heat-sensitive sheet. A drive pulse is applied to each heating element in each block a certain number of times by being divided.

Abstract: A multi-gradation recording method wherein the recording energy in high density region can be reduced, and the rough appearance in low density region or high density region and notchy appearance in profile or line of the image can be reduced while maintaining the level of reproduction of intermediate tones obtained by the conventional recording method using the zigzag pattern or the stripe pattern is provided which comprises: using a printer of the type wherein each one pixel is formed by using each one recording element and the optical density of the pixel formed is represented by the magnitude of the area of the pixel, dividing input data into two or more groups with respect to the data corresponding to pixels to be arranged in principal scanning direction, correcting the data of each group on the basis of the corresponding &ggr; correction data, the &ggr; correction data for the respective groups being different from each other, and performing recording on the basis of the corrected data wherein the pixels

Abstract: A thermal head has plural heating elements arranged in line in a main scan direction. The heating elements are supplied with a train of drive pulses while the thermosensitive recording sheet is conveyed in a sub scan direction crosswise to the main scan direction, for thermal recording to the recording material by one line. The heating elements are grouped into first and second groups. The drive pulse train for the first group of the heating elements is determined by starting the drive pulse train at a start of the one line. The drive pulse train for the second group of the heating elements is determined by ending the drive pulse train at an end of the one line.

Abstract: A thermal transfer recording apparatus for performing recording of data on a recording medium by transferring ink of an ink sheet on said recording medium comprises conveying means for conveying said ink sheet and recording medium, recording means for effecting said ink sheet to record image data on said recording medium, and control means for counting time after image recording by said recording means and driving said recording means when the next image recording is not performed in a predetermined time period.

Abstract: Line head thermal printing apparatus including a plurality of printing heating elements (2) designed to print, under the control of individual activation elements (7, 8) and by means of memory points (6; 46) of a printing register (5; 45), successive lines of points on a medium to be printed which is driven in advance against the head (1), which apparatus includes elements (10; 40) for individual write addressing of the memory points (6; 46).

Abstract: A thermal printer for forming an image on a sheet, with the image having a plurality of line image data. The thermal printer includes a thermal head having a plurality of linearly arranged thermal elements for forming the image. The total number of the thermal elements to be driven is determined. The thermal elements are driven for a predetermined time period in accordance with the line image data if the number of thermal elements to be driven is not greater than a predetermined value. If the total number of the thermal elements to be driven is greater than the predetermined value, then the predetermined time period is divided into a number of fractional time periods and the thermal elements are intermittently driven for each of the fractional time periods. The predetermined value is determined to avoid sticking between the thermal head and a thermosensitive sheet due to excess heat.

Abstract: A gradational printing method for performing a gradational printing by energizing a plurality of heat emitting elements arranged on a thermal head correspondingly to respective bits of digital gradation data representing a gray level. In case of this method, the plurality of heat emitting elements are divided into two or more blocks and the blocks are energized correspondingly to different bits of the digital gradation data. Thus, an energizing time, during which a maximum current should be supplied, can be reduced. Further, the weight of the printer can be light. Moreover, if the maximum electric current of a printer is equal to that of the conventional method, the duration thereof can be equal to the minimum duration of the energizing pulses corresponding to the bits of the gradation data. Consequently, the capacities of a power supply and a printer employing this method can be small. Further, the size and manufacturing cost of the power supply and the printer can be small.