JP2008284836A - Thermal transfer printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer printer which permits the printing speed to be adjusted as long as power consumption does not exceed the rated maximum power consumption on the basis of a tone value by a simple structure when an image quality adjustment is made to an input image. <P>SOLUTION: The thermal transfer printer 1 has a tone level adjustment value acquisition means 4 to acquire a tone level adjustment value of input digital image data, a tonal level adjustment means 4 to adjust the tone level of the input digital image data on the basis of the tone level adjustment value and output adjusted digital image data, control means (7, 8, 10) to control the on time of a strobe pulse driving a thermal head 9 on the basis of the tone level adjustment value and the adjusted digital image data and control the paper transfer speed and the ribbon transfer speed, and a printing means 9 to print at the paper transfer speed and the ribbon transfer speed by the thermal head 9 driven by the strobe pulse on the basis of the adjusted image data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal transfer printer apparatus, and more particularly, to a thermal transfer printer apparatus capable of controlling the driving of a thermal head, the paper conveyance speed, and the ribbon conveyance speed based on adjusted gradation values.

  In a conventional thermal transfer printer, the power consumption generated when printing image data consisting only of a gradation value (generally 0 gradation out of 0 to 255 gradations) having the highest density (black) is reduced. Generally, the maximum power consumption allowed by the apparatus, that is, the rated maximum power consumption is generally used. The thermal transfer printer device preferably prints at a high speed, but the power consumption increases when printing at a high speed, so the printing speed is limited by the maximum power consumption. Therefore, the printing speed of the thermal transfer printer device is not printed at a speed higher than the speed set to satisfy the rated maximum power consumption.

  As a countermeasure, there is a thermal transfer printer apparatus that changes the printing speed for each line in accordance with the maximum gradation value in one line data of the input image (see, for example, Patent Document 1). In Patent Document 1, 0 gradation is described corresponding to white.

JP-A-6-71912 (page 6, FIG. 3)

  Patent Document 1 changes the printing speed for each line, and requires a complicated configuration and control such as a gradation counter and a gradation comparator. In addition, the user often changes the print density by adjusting the image quality before executing the print, but Patent Document 1 never assumes such a case.

  The present invention has been made to solve these problems. When image quality adjustment is performed on an input image, a range that does not exceed the rated maximum power consumption based on the gradation value by a simple configuration. It is an object of the present invention to provide a thermal transfer printer apparatus capable of adjusting the printing speed within the printer.

  In order to solve the above problems, a thermal transfer printer apparatus according to the present invention includes a gradation level adjustment value acquisition unit that acquires a gradation level adjustment value of input digital image data, and an input digital image based on the gradation level adjustment value. Controls the on-time of the strobe pulse that drives the thermal head based on the tone level adjustment means that adjusts the tone level of the data and outputs the adjusted digital image data, and the tone level adjustment value and the adjusted digital image data And a control means for controlling the paper conveyance speed and the ribbon conveyance speed, and a printing means for printing at the paper conveyance speed and the ribbon conveyance speed by the thermal head driven by the strobe pulse based on the adjusted image data. It is characterized by.

  According to the first aspect of the present invention, the gradation level adjustment value acquisition means for acquiring the gradation level adjustment value of the input digital image data, and the gradation of the input digital image data based on the gradation level adjustment value. Based on the gradation level adjustment means for adjusting the level and outputting the adjusted digital image data, the on-time of the strobe pulse for driving the thermal head based on the gradation level adjustment value and the adjusted digital image data, Since the printing apparatus includes a control unit that controls the conveyance speed and the ribbon conveyance speed, and a printing unit that prints at the paper conveyance speed and the ribbon conveyance speed by the thermal head driven by the strobe pulse based on the adjustment image data. However, when image quality adjustment is performed, the maximum power consumption is not exceeded based on the gradation value with a simple configuration. It is possible to adjust the image speed.

  Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1>
FIG. 1 is a block diagram of a thermal transfer printer apparatus 1 according to Embodiment 1 of the present invention. The thermal transfer printer apparatus 1 includes a video input block 2 including a decoder that decodes an input video signal such as an NTSC system into an RGB video signal, and an A / D conversion that quantizes the RGB video signal into a digital video signal. A gradation level adjustment value is acquired from the quantization block 3 and the quantized RGB video signal (tone level adjustment value acquisition means), and the gradation level of the input digital image data is adjusted based on the gradation level adjustment value. An image quality adjustment block 4 having brightness adjustment (tone level adjustment means) for outputting adjusted digital image data, and a memory control block 5 having a memory controller for storing quantized RGB video signals, The DRAM 6 for storing the quantized RGB video signal and the quantized RGB video signal are connected to the thermal head drive Based on the print control block 7 provided with gradation-pulse conversion (strobe pulse generating means) for converting into a blue pulse, a RAM 8 for storing a plurality of reference tables for conversion into a strobe pulse for driving the thermal head, and adjustment image data A thermal head 9 (printing means) for printing at a paper transport speed and a ribbon transport speed by a thermal head driven by a strobe pulse, a microcomputer 10 for controlling a memory control block 5, a print control block 7, MDAs 11 and 13, and a paper A paper transport motor MDA11 that controls the transport motor 12, a paper transport motor 12 that is a stepping motor that transports paper for printing, a ribbon transport motor MDA13 that controls the ribbon transport motor 14, and a ribbon used for printing Rib is a stepping motor that transports It includes a transport motor 14, and a power supply block 30 supplies power to the thermal head 9.

  Based on the gradation level adjustment value and the adjusted digital image data, the on-time of the strobe pulse for driving the thermal head is controlled by the control means including the print control block 7, the reference table RAM 8, and the microcomputer 10, and the paper is conveyed. Controls the speed and ribbon transport speed. That is, the control means selects a reference table corresponding to the gradation level range from a plurality of reference tables that associate the gradation value of the adjusted digital image data with the strobe pulse ON time and a plurality of reference tables. And a strobe pulse generating means for generating a strobe pulse from the gradation value of the digital image data output from the gradation level adjusting means based on the reference table selected by the reference table selecting means. And a speed changing means for changing the paper transport speed and the ribbon transport speed based on the strobe pulse. The image quality adjustment block 4 includes calculation means for calculating a gradation level range. The gradation level range has a lower limit that is a gradation level adjustment value and an upper limit that is a predetermined maximum gradation value, or a lower limit that is a predetermined minimum. The range is a gradation value and the upper limit is a gradation level adjustment value.

  When a video signal is input to the video input block 2, the quantization block 3 generally quantizes it to 256 gradations (0 to 255 gradations). When the image quality adjustment block 4 does not perform gradation adjustment, as shown in FIG. 2, when the input signal is 0 gradation, the output signal is also 0 gradation, and similarly for the n gradation, n + 1 gradation, and 255 gradation. The input signal and the output signal have the same gradation value. The gradation value output from the image quality adjustment block 4 is stored in the DRAM 6 by the memory control block 5. The print control block 7 generates a strobe pulse for driving the thermal head 9 according to the gradation value of the video signal stored in the DRAM 6. For example, when the gradation value is 0, a strobe pulse for driving the thermal head 9 to generate heat (strobe pulse on, control voltage Von) using all the gradations using the reference table RAM 8 as shown in FIG. Generate. The reference table RAM 8 stores data for generating a strobe pulse having a predetermined time for the input gradation value, and generates a strobe pulse based on the data. At the time of printing, a control signal is transmitted from the microcomputer 10 to the paper transport motor MDA11 and the ribbon transport motor MDA13 in synchronization with the driving of the thermal head 9, and the paper transport motor 12 receives the control signal and the paper transport motor 12 causes the ribbon transport. The ribbon transport motor 14 is driven by the motor MDA13. When an image having an input signal whose gradation value is only 0 is printed, the power consumption of the power supply block 30 of the thermal transfer printer apparatus 1 is close to the rated maximum power consumption. The power consumption at that time has a relationship that is substantially proportional to the total heat generation of 256 gradations from the 0th gradation heat generation period T0 to the 255th gradation heat generation period T255.

  In the image quality adjustment block 4, when the black level of the video signal is increased, for example, brightness adjustment is performed, the gradation value of the video signal output from the image quality adjustment block 4 to the memory control block 5 is n or less as shown in FIG. No longer exists. From FIG. 4, the minimum value of the output gradation value (the value closest to the black level) is calculated by a simple calculation of a linear function. An arithmetic means for performing this calculation may be provided in the image quality adjustment block 4, for example. In the embodiment of the present invention, gradation adjustment is performed with reference to black. However, the same effect can be obtained by performing gradation adjustment with reference to white. When an image having only an input gradation value of 0 is printed after gradation adjustment is performed in the image quality adjustment block 4, the thermal head is driven from 0 gradation to n gradations as shown in FIG. The strobe pulse is not turned on. As a result, the time during which the strobe pulse per line is on is shortened, so that the overall power consumption of the thermal transfer printer apparatus 1 can be suppressed. The power consumption at that time depends on the total heat generation of 256 gradations from the 0th gradation heat generation period T0 ′ to the 255th gradation heat generation period T255 ′, but from the heat generation period T0 ′ to the heat generation period Tn ′. Since the corresponding strobe pulse is not asserted, power consumption is not affected. At this time, the sum of the on-time of the strobe pulses per line is expressed by the following equation (1).

  As shown in FIG. 6, with respect to the on time of the strobe pulse for driving the thermal head 9, the reference table is referred to from the reference table RAM 8 so that the on time becomes longer at a gradation value larger than n, and at the same time, the paper The conveyance speed of the conveyance motor 12 and the ribbon conveyance motor 14 is increased. As a result, it is possible to shorten the printing time without exceeding the rated maximum power consumption of the thermal transfer printer apparatus 1. The reference table is selected from a plurality of tables based on the minimum gradation value when the gradation is adjusted by the image quality adjustment block 4. An example of the selection method is shown below.

When the minimum gradation value is from 0 to n−1 Select the reference table 1 When the minimum gradation value is n or more Select the reference table 2

  Note that three or more reference tables may be stored in the reference table RAM 8. At this time, the maximum value of the power consumption is made equal to the rated maximum power consumption by setting the sum of the on-times of the strobe pulses per line, that is, the sum of the heat generation periods as shown in the following equation (2). It becomes possible.

  As shown in FIG. 6, the power consumption depends on the total heat generation for 256 gradations from the 0th gradation heat generation period T0 ″ to the 255th gradation heat generation period T255 ″, but the heat generation period T0. Since the strobe pulse corresponding to the period from "" to the heat generation period Tn "is not asserted, the power consumption is not affected. Therefore, the power consumption corresponding to the power consumption in the heat generation period Tn ″ from the heat generation period T0 ″ in which the strobe pulse is not asserted is used for the heat generation period Tn + 1 ″ and the heat generation period T255 ″ in which the strobe pulse is asserted. The paper transport motor 12 and the ribbon transport motor 14 are transported at a speed that is used to lengthen the heat generation period, and accordingly, in order to cancel out the increase in the color of the ribbon due to the longer heat generation period. increase. Such control can be performed by control programmed in advance by the microcomputer 10. That is, the microcomputer 10 functions as a reference table selection unit corresponding to the minimum gradation value, and a paper and ribbon conveyance speed changing unit according to the selection.

  As a result, the printing speed can be increased with a simple configuration within a range not exceeding the rated maximum power consumption.

<Embodiment 2>
FIG. 7 shows a block diagram when the thermal transfer printer apparatus 1 according to Embodiment 2 of the present invention and a PC (personal computer) 27 are connected. As shown in FIG. 7, the thermal transfer printer apparatus 1 and the PC 27 are connected by a USB (Universal Serial Bus), and a video signal is transmitted from the PC 27 to the thermal transfer printer apparatus 1 via the USB for printing. The PC 27 includes application software 28 that generates image data for printing, and a printer driver 29 provided with brightness adjustment for adjusting image quality. On the other hand, the thermal transfer printer apparatus 1 includes a USB control block 31 provided with a USB controller that controls transmission / reception of video data by USB in the thermal transfer printer apparatus 1.

  The gradation adjustment of the image quality of the image data generated by the application 28 is performed by the printer driver 29. Then, the minimum gradation value is transmitted to the USB control block 31 of the thermal transfer printer apparatus 1. That is, unlike the first embodiment, the thermal transfer printer apparatus 1 does not include the gradation adjustment unit and the calculation unit, but is externally provided in the PC 27 and receives the minimum value of the gradation value calculated by the PC 27. ing. Other operations and effects are the same as those in the first embodiment.

  As a result, the printing speed can be increased with a simple configuration within a range not exceeding the rated maximum power consumption.

1 is a block diagram of a thermal transfer printer apparatus according to Embodiment 1 of the present invention. FIG. 5 is a relationship diagram between an input gradation value and an output gradation value when gradation adjustment is not performed according to Embodiment 1 of the present invention. It is a figure which shows the strobe pulse in the gradation value 0 by Embodiment 1 of this invention. FIG. 6 is a relationship diagram between an input gradation value and an output gradation value when gradation adjustment is performed according to Embodiment 1 of the present invention. It is a figure which shows the strobe pulse when the gradation adjustment by Embodiment 1 of this invention is performed. It is a figure which shows the strobe pulse when the gradation adjustment by Embodiment 1 of this invention is performed. It is a block diagram of the thermal transfer printer apparatus and external apparatus by Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Thermal transfer printer apparatus, 2 Video input block, 3 Quantization block, 4 Image quality adjustment block, 5 Memory control block, 6 DRAM, 7 Print control block, 8 Reference table RAM, 9 Thermal head, 10 Microcomputer, 11 Paper conveyance motor MDA, 12 Paper transport motor, 13 Ribbon transport motor MDA, 14 Ribbon transport motor, 27 PC, 28 Application software, 29 Printer driver, 30 Power supply block, 31 USB control block.

Claims (5)

Gradation level adjustment value acquisition means for acquiring a gradation level adjustment value of input digital image data;
A gradation level adjusting means for adjusting a gradation level of the input digital image data based on the gradation level adjustment value and outputting the adjusted digital image data;
Based on the gradation level adjustment value and the adjusted digital image data, control means for controlling the on-time of the strobe pulse for driving the thermal head and controlling the paper conveyance speed and the ribbon conveyance speed;
Printing means for printing at the paper transport speed and the ribbon transport speed by the thermal head driven by the strobe pulse based on the adjusted image data;
A thermal transfer printer apparatus comprising:   The gradation level adjustment means includes calculation means for calculating a gradation level range, and the gradation level range has a lower limit that is a gradation level adjustment value and an upper limit that is a predetermined maximum gradation value, or 2. The thermal transfer printer apparatus according to claim 1, wherein the lower limit is a predetermined minimum gradation value and the upper limit is any one of gradation level adjustment values. The control means includes
A plurality of reference tables that associate the gradation values of the adjusted digital image data with the on-time of the strobe pulse;
A reference table selection means for selecting a reference table corresponding to the gradation level range from the plurality of reference tables;
Strobe pulse generating means for generating the strobe pulse from the gradation value of the digital image data output from the gradation level adjusting means based on the reference table selected by the reference table selecting means;
Speed changing means for changing the paper transport speed and the ribbon transport speed based on the strobe pulse;
The thermal transfer printer apparatus according to claim 2, comprising: In the control means,
4. The thermal transfer printer device according to claim 1, wherein when the on-time is increased, the paper conveyance speed and the ribbon conveyance speed are increased accordingly. A thermal transfer printer apparatus further comprising a transmission / reception means for transmitting / receiving the gradation level adjustment value,
The gradation level adjustment value acquisition means and the gradation level adjustment means are provided outside the thermal transfer printer device casing,
The transmission / reception means transmits the gradation level adjustment value acquired by the gradation level adjustment value acquisition means and the adjusted digital image data output by the gradation level adjustment means to the control means, 5. The thermal transfer printer apparatus according to claim 1, wherein the adjusted digital image data output by the gradation level adjusting unit is sent to the printing unit.

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