Victor Company of Japan, Limited

Tadao Shinya

Itsuo Takanashi

Toshinori Takahashi

Hiroki Kitamura

Hideshi Tanaka

Yutaka Mizoguchi

Kenichi Miyazaki

Terumi Ohara

Katsuhiko Terada

Toru Nibe

Yutaka Endo

Naomi Osada

Yutaka Endou

Each pixel receives a digital picture data having a multi-gradation data. A line composed of printing pixels having a thickness difference of multi-gradations is obtained on a recording paper by controlling whether or not there exist ink transcription by each gradation with a line head. A digital printer of printing a picture by recording a plurality of lines on a recording paper with scanning by the line head, comprising counting devices ( - - ) for counting a number of pixels to print at each gradation, dividing devices ( - - - - - - ) for dividing all pixels into several groups in accordance with the counting devices and deciding devices ( - - - - ) for deciding a number of groups. A range of grouping and as number of groups can be changed so as for a number of printing pixels in every group to be equal to a predetermined number of simultaneous turn-on pixels. During a printing operation at each gradation, a pixel of simultaneously printing in one line is limited to a unit of the group and prints each gradation a plurality of times. Accordingly, a number of simultaneous turn-on pixels can always be held constant except a specific case.

Digital printer and its printing method

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.

Gradational printing method

A thermal printing apparatus for printing input gradational images, characters and figures by using multilevel density which can appropriately regulate the levels of the densities representing the gradational images etc. to be printed by a linear thermal head having n heating resistors arranged in a line, the printing apparatus is provided with a density control unit for regulating, for example, the multilevel durations for energizing the heating resistors in accordance with n gradational printing data each corresponding to respective one of said resistors, and a data conversion unit, receiving a set of n original data for each line as the printing data, for producing p sets of n data for p split lines on the basis of the n original data, where p is an integer being equal to or greater than two, the p sets of n data being sequentially supplied to the density control unit set by set to print each line corresponding to the input gradational image, character and figure printing data as a plurality of split lines corresponding thereto, thereby increasing uniformity of density of print lines of pixels of the input gradational images, characters and figures by overlapping low density portions of dotes of adjacent split lines.

Thermal printing apparatus

A heat-sensitive hot-melt image transfer sheet transfers an ink image to a recording sheet when selectively heated by the heating element of the thermal head of a thermal printer. The image transfer sheet comprises a base coated on a surface thereof with a matrix of circular hot-melt ink dots at a constant pitch. The hot-melt ink dots are selectively meltable with heat applied through the base by the heating elements for transferring an ink image to the recording sheet held against the matrix of hot-melt ink dots.

Heat-sensitive hot-melt image transfer sheet

A method for manufacturing a color separation plate for screen dot color printing, having screen dots recorded thereon, the size of the screen dots corresponding to the density of one of the primary colors of an image to be printed, by one of the color signals corresponding to respective primary colors and obtained by reading out the image to generate an electric signal corresponding to the image and separating the electric signal into the color signals corresponding to the primary colors, respectively. A sheet of recording material (12) which is transparent and applicable to thermal transfer recording is prepared. Also prepared is a rotatable flat platen (11). The sheet (12) of the recording material is put on the flat platen and the flap platen is rotated by a specific angle from the position where the sheet of the recording material is put on the flat platen. Then, the thermal transfer recording is performed on the sheet of recording material, in accordance with one of the color signals, to manufacture the color separation plate corresponding to one of the primary colors.

Color separation plate manufacturing method

A thermal printing apparatus prints input gradational images, characters and figures by using multilevel density regulates the levels of the densities representing the gradiational images etc. to be printed by a linear thermal head having n heating resistors arranged in a row. The printing apparatus is provided with a density control unit for regulating, for example, the multilevel durations for energizing the heating resistors in accordance with n gradational printing data each corresponding to a respective one of said resistors, and a data conversion unit, receiving as printing data a set of n original data for each a plurality of lines parallel with the row of n resistors, for producing p sets of n data for p split lines on the basis of the n original data, where p is an integer equal to or greater than two, each of the p split lines being disposed in an area in which the line corresponding to the printing data should be printed, in parallel with the row of n resistors, the p sets of n data being sequentially supplied to the density control unit set by set to print the original line corresponding to the printing data by printing the split lines corresponding to the original line split line by split line so by shifting the linear thermal head in a direction perpendicular to the row of n resistors every time each of the split lines is printed, that each of the n printing data is represented by p dots.

A thermal printer comprises a thermal head and a printing data output circuit outputting printing data. A portion of the printing data is copied. The copied portion of the printing data is added to a head of the printing data to form a combination of the copied portion and the printing data. The data combination is outputted to the thermal head. The thermal head is driven with the copied portion to preheat the thermal head. Then, the thermal head is driven with the printing data to perform actual printing.

Thermal printer

A gradation control device for a thermal ink-transfer type printing apparatus controls an applying time of a current to each of heating elements of a thermal printing head depending on a voltage drop introduced between a power source and the thermal printing head, so that it is possible to constantly print the same gradation level with the same printing dot size regardless of the printing data.

Gradation control device for thermal ink-transfer type printing apparatus

A color correcting circuit for thermal printer comprises a first circuit for obtaining a first degree correction operation result, a second circuit for obtaining a second degree correction operation result, and a difference limiting circuit for selectively outputting a correction data. The first degree correction operation makes the relationship between the density of an input image and the density of an output image linear for each primary color. The second degree correction operation reduces a difference between the density of the input image and the density of the output image by use of the method of least squares for each primary color. The difference limiting circuit selectively outputs as the correction data the second degree correction operation result when a difference between the first and second degree correction operation results falls within a predetermined range of a boundary value, and selectively outputs as the correction data a value which is deviated from the first degree correction operation result by the boundary value when the difference falls outside the predetermined range of the boundary value. The color correction of the input image is carried out based on the correction data outputted from the difference limiting circuit.

Color correcting circuit for thermal printer selectively outputting a

A structure of a thermal head of the type using an ink paper or a heat-sensitive paper is disclosed. The structure includes an array of units each comprising a single resistance body and a pair of electrode members which respectively correspond to a first and a second heat-generating portions positioned at both ends of the resistance body, the electrode members being adapted to energize the resistance body. At least one of the first and second heat-generating portions of the resistance body is divided into a plurality of heat-generating members, and so is done one of the electrode members which is associated with those heat-generating members.

Thermal printhead

A picture information processing system processes a picture information so that a printing area of each of dots constituting a picture is variably set depending on printing areas of the dots surrounding each dot. The picture information processing system comprises a memory for pre-storing an optimum printing area of a dot for each of dot patterns. The optimum printing area of one dot is obtained depending on the printing areas of the dots surrounding the one dot, and the optimum printing area is obtained for each of the dot patterns which are formed by the one and the surrounding dots.

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Yokohama, Japan

Tadao Shinya