Fuji Photo Film Company, Limited

Hisashi Enomoto

Nobuo Katsuma

Shinji Hayashi

Kouichi Hirasawa

Hiroyuki Matsukawa

Yoshiki Kawaoka

Sugio Makishima

Michitoshi Takayama

Yoshiki Takeoka

Illumination adjustment of LEDs is carried out prior to printing to a color thermosensitive recording paper with each thermosensitive coloring layer of yellow, magenta, and cyan. A light control circuit lights on the LEDs by one line printing period upon printing to each thermosensitive coloring layer, and makes CCD line sensors use its reflected light to image lateral edge of the color thermosensitive recording paper. Consequently, the output signal from the CCD line sensors is set within the linearity.

Printer

A lateral edge of a color thermosensitive recording paper in the main scan direction is detected. An edge heating element closest to the lateral edge is specified. The distance W between the edge heating element and the lateral edge of the color thermosensitive recording paper is detected. The proportion of the distance W to the width Wt of the heating element is calculated. Recording density of the edge heating element is lowered according to the proportion. The boundary between the edge of the recording paper and the print image is blurred.

Printer and printing method

A color thermal printer has thermal heads for recording yellow, magenta and cyan mono-color image, respectively. An mono-color image data of each mono-color image is processed in image data processing section, and thereafter sent to the thermal head. A correction CPU for each mono-color image reads out mono-color image data at each line to calculate a transport friction fluctuation at the thermal head between recording line and a first previous line thereto. Further, the correction CPU calculates a correction of heat energy of the thermal head on the basis of all of the transport friction fluctuation of the thermal heads.

Color thermal printer

There is disclosed a data processing method for correcting heating data for a thermal head of a thermal printer, to eliminate influence of heat energy accumulated in first to Nth heat accumulating layers of the thermal head. Basic heating data of a subject line is corrected with first to Nth correction data obtained by multiplying first to Nth heat accumulation data by predetermined coefficients respectively. The heating elements are driven in accordance with the corrected heating data, to print the subject line. A drive voltage to be applied across heating elements of the thermal head is determined at the start of printing a frame of image, according to an environmental temperature around the thermal head and a head temperature measured through a thermistor mounted in the Nth heat accumulating layer of the thermal head. The Nth coefficient is calculated according to a formula that includes the head drive voltage as a parameter.

Data processing method for eliminating influence of heat accumulation in thermal head of thermal printer

A thermal printer has a thermal head, which applies recording heat energy to an effective recording region on a thermosensitive recording sheet. The thermal head includes an array of heating elements arranged in a main scan direction. The recording sheet is conveyed relative to the thermal head in a sub scan direction perpendicular to the main scan direction, for recording at least one input image to the recording sheet. The effective recording region is separated into an insertion region, a template region and a blank frame region. The frame region extends in a linear shape with a small width. A first borderline is defined between the insertion region and the frame region, and a second borderline is defined between the template region and the frame region. The first borderline includes at least one first borderline segment being straight or curved, extends crosswise to the sub scan direction and is inclined with reference to the main scan direction. The input image is recorded in the insertion region. At least one template image is recorded in the template region, to constitute a synthesized image in combination with the input image.

Thermal printing method and thermal printer

A thermal printing method for printing an image line by line on a recording material by driving an array of heating elements of a thermal head while transporting the recording material relative to the thermal head. Heating data for recording a subject line to print is corrected in accordance with heat accumulation amounts of the heating elements. Surface temperatures of the respective heating elements are estimated on the basis of corrected heating data. A frictional force that will be generated between the thermal head and the recording sheet on recording the subject line is calculated on the basis of the estimated surface temperatures. The heating elements start being driven to record the subject line at a time shifted by a time shifting amount from a standard time. The time shifting amount is determined depending upon the frictional force so as to eliminate influence of fluctuations in transport speed of the recording sheet on the printed image.

Thermal printing method for preventing degrading of print quality due to

A thermal head has a heating element array with a plurality of heating elements disposed in line and a head driver. The head driver drives the heating elements at the same time in accordance with each set of heating data of 8 bits to record dots of one line on a recording sheet. In printing dots by using heating data of 9 bits, a heating data divider circuit divides the 9-bit heating data into two series of 8-bit converted heating data. By using these two series of the 8-bit converted heating data, two heating sequences are continuously executed. Each heating element is heated by the two heating sequences as many times as that corresponding to the heating data.

A thermal printer using a thermal head having a plurality of heating elements arranged in line, wherein the heating elements are driven for different power conduction times to record dots at different densities. According to the invention, the thermal printer is comprised of a first look-up table for converting original heating data into time data representative of a power conduction time corresponding to the original heating data; a correction circuit for correcting the time data to obtain a corrected power conduction time; a second look-up table for converting the corrected power conduction time into corrected heating data which corresponds to the corrected power conduction time; and a head driver for driving the heating elements in accordance with the corrected heating data.

A data processing apparatus for correcting heating data for a thermal head to eliminate influence of heat accumulation in the thermal head on recording density. The apparatus is comprised of a correction circuit having a subtracter for subtracting first correction data from original heating data of a subject line to print, in pixel-to-pixel correspondence; and first to Nth operation circuits provided in correspondence with first to Nth heat accumulating layers of the thermal head respectively. The first operation circuit has a register storing first heat accumulation data for one line, a multiplier for multiplying the stored first heat accumulation data by a coefficient to provide the first correction data; a multiplier for multiplying the original or the corrected heating data of the subject line by a coefficient to provide a first value for each pixel of the subject line; a multiplier for multiplying the stored first heat accumulation data by a coefficient to provide a second value for each pixel of one line; and an adder for adding the first and second values in pixel-to-pixel correspondence. A new series of first heat accumulation data is obtained from output data of the first adder, and is stored in the register in place of the previously stored first heat accumulation data. The Jth operation circuit, J being 2 to N, has the same construction as the first operation circuit, and prepares Jth heat accumulation data based on previously stored Jth and (J-1)th heat accumulation data, to provide Jth correction data based on the Jth heat accumulation data.

Data processing method for eliminating influence of heat accumulating in

A direct color thermal printer is used with color thermosensitive recording sheet (23), and prints a pixel (i, j) to it in accordance with 8-bit digital data g(i, j), namely brightness data (Y) and chrominance data (R-Y, B-Y). The digital data is compensated by use of a second-order differential operator. An integer 128 is added to the digital data g'(i, j) being compensated. A sum of 128 and the compensated digital data is limited to a range of nine bits, so as to heighten halftone of the pixel to be printed.

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Saitama, Japan

Hisashi Enomoto