JP2010131815A - Sublimation type printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a condition that the density of several lines at the beginning of printing of a printed article printed by a sublimation type printing apparatus is thin, to the same density as that for the lines other than the beginning of printing. <P>SOLUTION: A thermal head driving system for the sublimation type printing apparatus has a means in which on several lines at the beginning of printing, the total number of exothermic resistance bodies of the thermal head are energized simultaneously, and on the lines other than the beginning of printing, the exothermic resistance bodies of groups of odd number-th and the exothermic resistance bodies of groups of even number-th are energized alternately without overlapping in time, and as the result, twice number of energization can be realized on several lines at the beginning of printing in comparison with the lines other than them. In addition, the system has a power source circuit part having an ability to perform energization to the exothermic resistance bodies being a half of the whole exothermic resistance bodies of the thermal head, and has a back-up capacitor in parallel with the power source circuit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sublimation type printer apparatus in which a dye applied to an ink ribbon is sublimated and adhered to a dedicated sheet by heat generated when a thermal head having a plurality of heating element resistors arranged in a row is energized. Relates to a thermal head drive system that prevents energization of the heat-generating resistor at the beginning of the image, compensates for the temperature rise and deficiency at the beginning of the image, prevents density reduction, and provides a clear image with different shades at the start of the image. .

  Conventionally, in a sublimation type printer apparatus, a current corresponding to the number of gradations of an image to be printed is applied to a heating resistor arranged in a row on a thermal head, and as a result, the generated heat is applied to an ink ribbon. Dyeing dyes on a special paper. In order to form a color image, image data having gradations for each color component of yellow, magenta, and cyan is created, and on the ribbon coated with yellow, magenta, and cyan dyes according to the number of gradation data. Energize the heat generating resistor of the thermal head.

However, the temperature rise of the heating resistor is deeply related to the temperature of the heating resistor itself before energization. That is, at the beginning of printing (the heating resistor is energized from the ambient temperature) and in the middle of printing (the energization after reaching a certain heating temperature), the temperature reached by the heating resistor is the same even when energizing for the same number of gradations. In contrast, the temperature reached at the beginning of printing is lower. As a result, at the beginning of printing, the paper moves before reaching the temperature at which the dyes of each color are sufficiently sublimated and diffused, and a sufficient density cannot be obtained. (See Figure 6.)
As a method for increasing the density in one line, there has been proposed a method in which energization is performed by concentrating the current distribution timings in one line disclosed in Japanese Patent Laid-Open No. 7-164667.
JP-A-7-164667

  However, in the conventional example, the thermal energy generated by the heating resistor is the same even when the timing of energizing the heating resistor is dispersed and concentrated, and a large temperature rise cannot be expected, so that the density at the start of drawing is corrected deeply. There was a problem of being insufficient.

  An object of the present invention is to provide a clear image with high density by increasing the density at the beginning of the image.

In order to achieve the above object, the invention according to the present application
The N line at the beginning of drawing is energized simultaneously for all of the heating head's heating resistors, and the odd-numbered and even-numbered heating resistors other than the N line at the beginning of drawing are alternately energized in time. Means for realizing twice the number of energization times when energizing without overlapping is provided.

  Furthermore, it has a power supply circuit section capable of energizing half of all the heating resistors of the thermal head, and has a backup capacitor in parallel with the power supply circuit. As a result, an apparently double current supply to the thermal head is possible, and all the thermal heads are energized simultaneously.

  As described above, according to the present invention, in the sublimation type printer device, for the first N lines, all of the plurality of heating resistors arranged in a line on the thermal head are energized at the same time. At first, when printing lines other than the N line, the heat generating resistors of the thermal head are divided into odd-numbered groups and even-numbered groups. By giving it to the applied ink ribbon, it is possible to print the image at a sufficiently high density even at the beginning of printing, and it is possible to form a clear printed matter with a light and shade at the beginning of printing.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  FIG. 1 shows a configuration diagram of a camera direct print system including a sublimation printer using the thermal head drive control method of the present embodiment.

  In FIG. 1, 1 is a digital camera which is an optical image forming apparatus, and 2 is a direct printing apparatus which outputs a digital image to printing paper. Reference numeral 3 denotes a cable for exchanging data between the digital camera 1 and the direct printing apparatus 2. In the present embodiment, the USB protocol is used, so the USB cable is used.

  When image transfer is executed, the digital camera and the direct printing device negotiate according to the USB protocol, and image transfer starts. The data is communicated through the USB cable 3.

  The direct printing apparatus of this embodiment will be described a little more.

  Reference numeral 4 in FIG. 1 denotes a composite card slot for exchanging image data with a card-type recording medium such as an SD memory card (SD). Reference numeral 5 denotes an LCD monitor for displaying a graphical user interface (GUI) for operating the direct printing apparatus. 6 is a power switch of the apparatus, and 7 is various switches as operation members of the apparatus.

  Next, a block diagram of the direct printing apparatus of this embodiment will be described with reference to FIG. A CPU 10 controls the entire apparatus, processes a digital image, controls USB communication, and controls an LCD. An IC memory 11 stores a program for controlling the apparatus, icon data for GUI displayed on the LCD monitor 17, frame data for image synthesis, and the like. Reference numeral 12 denotes an SDRAM as a work memory for storing data to be used during program operation or image processing or displayed on an LCD monitor. Reference numeral 13 denotes a thermal head of the sublimation printer section, a head / motor control IC for controlling the LF motor and the UD motor, and reference numeral 14 denotes a thermal head which is a main part of the sublimation printer. In the thermal head, 1280 heating elements are arranged in a row. The present invention proposes a drive control method for on / off control of the heating element. Reference numeral 15 denotes a motor driver that drives an LF motor and a UD motor. Reference numeral 16 denotes an LCD driver for driving the LCD monitor 17. Reference numeral 17 denotes an LCD monitor for displaying a digital image and a graphical user interface (GUI) for operating the apparatus. Reference numeral 18 denotes a USB HUB for distributing USB protocol data, which is connected to the card memory controller and the USB A connector. A card memory controller 19 having a USB interface is connected to the composite card slot.

  FIG. 3 is a schematic diagram for explaining the basic principle of the sublimation printing method used in the image output portion of the direct printing apparatus of this embodiment. The sublimation printing method is a method using a diffusion phenomenon of a dye (pigment). In the figure, reference numeral 31 denotes an ink sheet in which three color (yellow, magenta, and cyan) dyes are applied to a plastic sheet. The ink sheet 31 is overlapped with the dedicated printing paper 32 and is sandwiched between the thermal head 33 and the platen roller 34, and the ink sheet is sublimated / thermally diffused onto the dedicated printing paper 32 by the heat of the thermal head 33. Get a color print.

  The dedicated printing paper 32 is coated with a receiving layer 36 containing a polyester resin as a main component in order to secure the color of the sublimation dye 35. At this time, gradation can be given by controlling the heat applied to the thermal head 33. By giving gradation to each of the three colors (yellow, magenta, and cyan) and printing at the same location on the photographic paper, high-definition full-color printing in units of one pixel can be realized.

  The thermal head of this embodiment has 1280 heating resistors arranged in one row.

  In the present embodiment, the thermal head drive system other than the N line at the start of the drawing divides the 1280 heating resistors into an odd-numbered group and an even-numbered group in the order of arrangement, and conducts 640 currents in half. This is because a large current flows when 1280 heating resistors are energized simultaneously, so that the current supply capacity of the power supply circuit becomes very large and the power supply circuit itself becomes large, which is not preferable as a consumer product. Because it becomes a form.

  On the other hand, in the driving method of the N-line thermal head at the start of printing in this embodiment, all 1280 heating resistors are energized simultaneously. For this purpose, the power supply circuit designed on the assumption that current is supplied to the maximum half of the heat generating resistor is insufficient in current supply capability. Therefore, in this embodiment, a backup capacitor is installed in parallel with the power supply circuit.

  FIG. 4 is a diagram for explaining the relationship between the power supply circuit and the backup capacitor. In the figure, 41 is a power supply circuit, 42 is a backup capacitor, and 43 is a thermal head in which 1280 heating resistors are arranged in a row.

  In addition to the 1280 heating resistors, the thermal head transfers image printing data to the heating resistors, and a circuit having a configuration as shown in FIG. 5 in order to pass a current through the heating resistors in accordance with the data. have. A D flip-flop (F), a latch (L), an AND circuit, and an FET are connected to each heating resistor. FIG. 5 shows only six sets of circuit configurations, but 1280 of the circuit configurations are mounted on the thermal head of this embodiment.

  Each of the heating resistors is connected to a head power supply, and a current flows through the heating resistor when the FET is turned on. Whether or not this FET is turned on is determined by image printing data. The 1280 sets of circuit blocks are divided into 10 groups called 128 channels, and these 10 channels operate in parallel. 128 D flip-flops (F) are connected to form a shift register. 128 pieces of image printing data are serially input to the shift register, and are shifted by one bit in synchronization with the data transfer clock, and all the image printing data is stored in the D flip-flop at the 128th clock. When the data is stored, the data is held in the latch circuit. The output of the latch circuit is connected to one input of the AND circuit. The other of the AND circuit is connected to the strobe (STB) signal, and the strobe signal is enabled at the next timing when all data is held in the latch circuit. As a result, the ON / OFF state of the FET is determined according to the logic of the data held in the latch circuit, and it is determined whether or not the current flows to the heating resistor.

  Here, one energization / non-energization of the heating resistor corresponds to one gradation of the pixel. Therefore, in order to express 256 gradations, the above signal transmission is repeated 256 times. That is, the heating resistors arranged in one row are energized and de-energized 256 times in accordance with the image printing data “1” and “0”, thereby forming an image for one line. By repeating this for a predetermined number of lines, one color of the entire image is printed. Further, a color image is completed by performing the image formation with each color of yellow, magenta, and cyan.

  In sublimation printers, the heating resistors arranged in a row on the thermal head are energized to form an image by sublimating and diffusing the dye applied to the ink ribbon onto the special paper. The temperature rise strongly depends on the temperature of the heating resistor itself before energization. For example, since the heating resistor is not energized in the first line at the start of drawing, the heating resistor itself is at the ambient temperature, and energization is performed based on that temperature, and the temperature of the heating resistor increases. In the second and subsequent lines, the temperature rises based on the temperature that the heating resistor had in the previous line, so the temperature is higher than in the previous line. As the number of lines increases, the temperature difference from the previous line decreases and the temperature of the heating resistor becomes substantially constant.

  Therefore, the amount of dye applied to the ink ribbon by sublimation and diffusion to the special paper due to the heat energy due to the temperature rise of the heating resistor is small at the beginning of the image, and after the number of lines increases, A certain amount of dye will be sublimated and diffused. This is shown schematically in the figure. In the drawing, the left side represents the start of drawing, and the first line has a lighter density, the density becomes higher as the line progresses, and an image having a constant density is formed from the existing line.

  A driving method other than the N line at the start of printing in this embodiment will be described with reference to FIG. In FIG. 7, the amount by which the dye applied to the ink ribbon is sublimated and diffused on the paper by one energization of the heating resistor is represented by an ellipse. Actually, this ellipse overlaps to form a pixel with gradation, but here the horizontal axis is extended so that the ellipses do not overlap.

  Usually, in order to express black, 256 energizations are performed per line, so that it is expressed by 256 ellipses, but here it is simplified and expressed by 8 ellipses. Therefore, in FIG. 7, since there are six ellipses in one line, 75% gray is represented by two lines. An ellipse is formed from the right side of FIG. The figure shows how the ellipses of odd-numbered rows are formed first, then the ellipses of even-numbered rows are formed, and then the ellipses are alternately formed in odd-numbered rows and even-numbered rows. As described above, in the conventional example, pixels are formed by alternately energizing adjacent heating resistors.

  Next, a method of driving the thermal head for the N line at the start of printing in this embodiment will be described with reference to FIG. In FIG. 8, two lines are represented as in FIG. In the first line, unlike the conventional example, ellipses are simultaneously formed in odd-numbered rows and even-numbered rows. That is, there is an effect of increasing the amount of dye applied to the ink ribbon to be sublimated and diffused on the paper by increasing the number of times of energization to the heating resistor than the driving method other than the N line at the beginning of the image.

  As described above, in this embodiment, all 1280 heating resistors arranged in the thermal head are energized at the same time up to the first N lines of printing, and the odd-numbered groups and even-numbered lines are arranged in the other lines. Energize the second group alternately without overlapping in time. As a result, it is possible to pass a current through the heating resistor twice up to the N line at the start of printing as compared to the other lines, and it is possible to correct and darken the state where the density at the start of printing is low.

  In the second embodiment of the present invention, the system configuration and the block diagram of the direct print system are the same as those of the first embodiment, and the description thereof will be omitted.

  FIG. 9 shows a second realization method of power supply for energizing all the heating heads of the thermal head at the same time in the print start N line which is the proposal.

  FIG. 9 shows the relationship between the power supply of the sublimation printer and the energization of the thermal head. In the figure, 101 is a power supply circuit unit, and 102 is a rechargeable battery. The power supply circuit 101 also has a function of charging the rechargeable battery 102. Reference numeral 103 denotes a switch for switching connection between the power supply circuit, the thermal head, and the rechargeable battery, and reference numeral 104 denotes a switch for connecting the rechargeable battery and the thermal head. Reference numeral 105 denotes a thermal head in which heating resistors are arranged in a line.

  For the N lines at the beginning of printing, it is possible to flow current simultaneously through all the heating resistors of the thermal head by connecting the thermal head and the power supply circuit with the switch 103 and connecting the rechargeable battery and the thermal head with the switch 104. . This is the print mode 3 in FIG.

  FIG. 10 is a table showing the relationship between each mode and switch of the sublimation type printer apparatus. In the printing mode 1, printing is performed by the power supply circuit, and in the printing mode 2, printing is performed by the rechargeable battery. The charging mode is entered except during printing, and the switch 103 is connected to the rechargeable battery as shown in FIG.

  As described above, in this embodiment, all 1280 heating resistors arranged in the thermal head are energized at the same time up to the first N lines of printing, and the odd-numbered groups and even-numbered lines are arranged in the other lines. Energize the second group alternately without overlapping in time. As a result, it is possible to pass a current through the heating resistor twice up to the N line at the start of printing as compared to the other lines, and it is possible to correct and darken the state where the density at the start of printing is low.

The figure explaining the structure of a camera direct print system. The block diagram of the direct print storage apparatus of an Example. The figure explaining the outline | summary of a sublimation type printing system. The figure explaining the relationship between the power supply circuit of this 1st Example, and a backup capacitor. The figure explaining the internal circuit of a thermal head. FIG. 4 is a diagram for explaining insufficient density at the start of printing. The figure explaining the electricity supply method of the thermal head in the middle of printing. The figure explaining the energization method of the thermal head of the printing start. The figure explaining the relationship between the power supply circuit of a 2nd Example, and a rechargeable battery. The figure explaining the operation mode of the 2nd Example.

Explanation of symbols

1 Digital Camera 2 Direct Print Storage Device 3 USB Cable 4 Compound Card Slot 5 LCD Monitor 6 Power Switch 7 Various Switches 10 CPU
11 IC Memory
12 SDRAM
13 Head motor control IC
14 Thermal Head 15 Motor Driver 16 LCD Driver 17 LCD Monitor 18 USB HUB
19 Card Memory Controller 31 Ink Sheet 32 Dedicated Printing Paper 33 Thermal Head 34 Platen Roller 35 Sublimation Dye 36 Receiving Layer

Claims (3)

  The thermal head is provided with energization means for the heating resistors arranged in a line in the thermal head, and the energization means energizes all the heating resistors at the same time for the N line at the start of printing, and the other lines are arrangements of the heating resistors. Dividing into odd-numbered groups and even-numbered groups in order, the energization to the heating resistors of the odd-numbered group and the energization of the heating resistors of the even-numbered group are performed without overlapping in time. Sublimation type printer device.   A power supply circuit section capable of energizing half of all the heating resistors of the thermal head and having a backup capacitor in parallel with the power supply circuit, and the power supply circuit at the time of N line printing at the start of printing; The sublimation type printer apparatus according to claim 1, wherein the current supply is apparently doubled to the thermal head by receiving current supply from the backup capacitor, and all the thermal heads are energized simultaneously.   A power supply circuit capable of energizing half of all the heating resistors of the thermal head; and the power supply circuit has a charging function for a rechargeable battery capable of supplying power to the sublimation printer. In addition, when N lines are printed at the start of printing, current is supplied from the power supply circuit and the rechargeable battery so that the current is apparently doubled and all the thermal heads are energized simultaneously. 1. A sublimation type printer device according to 1.

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