JPH07137326A - Operation device of thermal transfer printer - Google Patents

Abstract

PURPOSE:To realize stable density and color reproducibility by suppressing density irregularity by stabilizing the temp. of a head at the start time of the printing of respective colors. CONSTITUTION:Even at the start time of printings 104, 106 with inks on and after a second color, the temp. of a head is controlled like 103, 105 within a predetermined temp. range in the same way as head temp. control 101 at the start time of printing 102 due to first color ink and, thereafter, printing is started. By this constitution, the temp. of a head at the point of time when a printer starts printing on and after a second color is stabilized in the same way as the first color and, as a result, printing density is stabilized and color reproducibility can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer or a thermal transfer printer for expressing printing gradation by controlling the temperature of a thermal head or a thermal line head (hereinafter abbreviated as head) using a multicolor ink sheet applied in a frame sequential manner. The present invention relates to a thermal printer (hereinafter abbreviated as a printer), and particularly to a head temperature control method at the start of printing of each color of a multicolor ink sheet.

[0002]

2. Description of the Related Art In a conventional printer, a frame-sequential multicolor ink sheet is thermally transferred one by one onto a recording paper to obtain a color image or a character print. For example, a head in which a large number of heating elements are arranged in a direction perpendicular to the paper transport direction of recording paper is controlled in heat generation in accordance with input image data to print one line, and this operation is performed multiple times along with paper transport. I was printing one color. By performing similar printing on the other color ink sheets thereafter, color printing by mixing a plurality of colors has been realized.

As an example, printing with a four-color ink sheet will be described. It is composed of yellow (hereinafter abbreviated as Ye or Y), magenta (hereinafter abbreviated as Mg or M), cyan (hereinafter abbreviated as Cy or C), and black (hereinafter abbreviated as Bk or K), and is sequentially printed. It

First, when a print start command is sent from a control device such as a personal computer outside the printer, the printer performs initial setting necessary for printing one color, such as recording start positioning control of Ye ink sheet and recording paper, After that, the ink is printed on the recording paper according to the input data.

Similarly, after the recording start positioning control of the Mg ink sheet and the positioning control of the recording paper are performed, the Mg ink is printed on the recording paper.

In the case of printing with Cy ink and Bk ink, printing is performed by the same procedure.

Finally, the recording paper is discharged and printing is completed.

By the way, in the printer, the head is protected,
For the purpose of stabilizing the print density, the print operation is started only when the head temperature at the start of printing for one color is within a predetermined temperature range.

When the head temperature at the start of printing satisfies the predetermined temperature range, the temperature control is not performed and the printing operation is started.

When the head temperature at the start of printing is lower than the minimum value in the predetermined temperature range, the head is heated to the minimum value in the predetermined temperature range or higher to start the printing operation.

On the contrary, when the head temperature at the start of printing is higher than the maximum value in the predetermined temperature range, the head is cooled to the maximum value in the predetermined temperature range or less to start the printing operation.

As an example of such a head temperature control system, Japanese Patent Application Laid-Open No. 1-165458 is disclosed.

When printing with multicolor ink, 1
The head temperature control is performed only when printing with the color ink (Ye ink in the above example) is started, and printing is performed regardless of the head temperature when printing with subsequent color inks is started.

[0014]

In the prior art printer, the head temperature control is only performed at the start of printing with the first color ink, so the head temperature at the start of printing with the second and subsequent colors of ink is not always the same. It is not always within the predetermined temperature range.

Therefore, the head temperature at the start of printing of each color varies each time printing is performed. Therefore, the print density of each color may not achieve the desired density.

An object of the present invention is to stabilize the head temperature at the start of printing of each color, thereby suppressing variations in density and realizing stable density and color reproduction.

[0017]

The object of the present invention is to control the head temperature within a predetermined temperature range at the start of printing with the second and subsequent inks, as well as the head temperature control at the start of printing with the first ink. It can be achieved by starting printing.

[0018]

Since the head temperature at the start of printing of each color ink is stable, the print density is stable.

[0019]

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

FIG. 1 is a diagram for explaining the principle of head temperature control according to an embodiment of the present invention, and shows a case where three color inks of YMC are used.

In FIG. 1, the horizontal axis represents the passage of time and the vertical axis represents the detected head temperature. Th and Tl are the maximum value and the minimum value of the head temperature in the predetermined temperature range, and this section is the predetermined temperature range.

Reference numeral 101 is for initial printing of a mechanism such as positioning control of a recording medium (for example, recording paper or ink sheet) necessary for printing with the first Ye ink and head temperature control by heating and cooling. It took the print preparation period. 102 is the actual print time for actually printing with Ye ink. 103 and 105 are print preparation times for the Mg ink and the Cy ink, respectively. 10
4 and 106 are the actual print times with Mg ink and Cy ink, respectively. Reference numeral 107 is a time period in which post-printing processing such as recording paper discharge / cutting and pre-processing for controlling the mechanical unit for the next page printing are combined.

The operation of the present invention will be described below with reference to FIG.

When the printer receives a print command from an external controller such as a personal computer, the printer controls the head temperature within a predetermined temperature range in parallel with the initial setting of the mechanical section or in the period 101 after the initial setting. . In FIG. 1, since the head temperature at the time of receiving the print command is equal to or lower than the lowest value Tl in the predetermined temperature range, the head is heated by controlling the head to generate heat, for example. Here, the head temperature is the highest value Th in the predetermined temperature range.
In the above case, the head is cooled using, for example, a fan. If the head temperature is within the predetermined temperature range, head temperature control is not performed.

At 102, the heat generation amount of the head is controlled according to the input data from the external controller, and printing is performed on the recording paper with the Ye ink.

During the print preparation period with Mg ink, Ye
As a result of printing with the ink, the head temperature became lower than the minimum value Tl in the predetermined temperature range. Therefore, the head temperature was set to Tl in parallel with or after the initial setting of the mechanical unit required for printing with the next Mg ink. The heating of the head is controlled as described above. After that, actual printing with the Mg ink is started as soon as the head temperature becomes Tl or higher.

Next, in the print preparation period with the Cy ink, as a result of printing with the Mg ink, the head temperature became higher than the maximum value Th in the predetermined temperature range, so that the head temperature becomes Th or less as in 103. Control to cool the head. After that, actual printing with Cy ink is started as soon as the head temperature becomes Th or lower.

As described above, the print preparation time for the second and subsequent colors is controlled so that the head temperature at the start of printing is within the predetermined temperature range.

In FIG. 1, the case where the head temperature control time is longer than the initial setting time of the mechanism has been described, but conversely, the head temperature control time may be shorter.
In addition to that, even if the head temperature is within the predetermined temperature range at the time of starting the initial setting of the mechanical section, it may be outside the predetermined temperature range by the start of printing. For this reason, an example will be described with reference to the principle explanatory diagram of FIG. 2 in the case where the head temperature is ended before the end of the initial setting of the mechanical section.

In FIG. 2, components having the same functions as those in FIG. 1 are designated by the same reference numerals. tY is the time when the head temperature control of FIG. 1 is completed during the print preparation period with the Ye ink.

The head temperature is continuously monitored for the time from tY to the actual printing with the Ye ink, and the minimum value T within the predetermined temperature range is set.
When it becomes lower than 1, control is performed to heat the head as in FIG. If the head temperature is within a predetermined temperature range, head temperature control is not performed.

In this example, when the temperature becomes lower than the lowest value in the predetermined temperature range, but when it becomes higher than the highest value Th in the predetermined temperature range, the head is controlled to be cooled. If the head temperature is within a predetermined temperature range, head temperature control is not performed.

By such head temperature control, actual printing can be started within the predetermined temperature range even if the initial setting of the mechanical section is completed before the head temperature control of FIG. 1 during the print preparation time.

FIG. 3 is a diagram explaining the principle of another head temperature control in one embodiment of the present invention.

In FIG. 3, components having the same function as in FIG. 1 are designated by the same reference numerals. t0 represents the head temperature at the start of printing with Ye ink.

The operation of the present invention will be described below with reference to FIG.

The operations from 101 to 102 are the same as in FIG.

During the print preparation period 103 with the Mg ink, the head temperature became lower than T0 as a result of the printing with the Ye ink. Therefore, in parallel with the initial setting of the mechanical unit required for the next printing with the Mg ink, or After the initial setting, control is performed to heat the head so that the head temperature becomes equal to T0. After that, actual printing with the Mg ink is started as soon as the head temperature becomes substantially equal to T0.

Next, since the head temperature became higher than T0 as a result of printing with the Mg ink during the print preparation period with Cy ink, control is performed to cool the head so that the head temperature becomes equal to T0, similar to 103. To do. After that, as soon as the head temperature becomes substantially equal to T0, actual printing with Cy ink is started.

In this way, control is performed so that the head temperature at the start of printing with the second and subsequent inks is equal to the head temperature at the start of printing the first color.

Although FIG. 3 illustrates the case where the head temperature control time is longer than the initial setting time of the mechanism section as in FIG. 1, the head temperature control time may be short.
In addition, even if the head temperature is almost equal to T0 at the time when the initial setting of the mechanical unit is started, the temperature difference from T0 may be large by the start of printing.
Therefore, by performing the head temperature control of FIG. 2, even when the initial setting of the mechanical unit is completed before the head temperature control of FIG. Actual printing can be started with head temperatures that are almost equal.

FIG. 4 is a block diagram of a print engine which realizes the above embodiment of the present invention.

In FIG. 4, a central controller 301 is a device for controlling the entire print engine. The head 302 is a device that prints data on a recording medium. The temperature detector 303 is a device that detects the current head temperature. The temperature comparator 304 is a device that compares the current head temperature with a predetermined predetermined head temperature. The head cooling device 306 is a device that cools the head by blowing air to the head with, for example, a fan. The gradation control device 306 is a device that performs normal gradation control of image data and head heating control. The mechanical unit 311 is a mechanical unit of a printer that carries recording paper and ink sheets. The mechanism control device 310 is a device that controls the mechanism unit 311 to perform positioning control and the like. The engine control device 399 is a device that sends data and a print command to the print engine to control the print engine.

The print engine is an engine controller 39.
When the central control device 301 receives a print command from the printer 9, printing is started. First, the central control unit checks the current state of the mechanical unit 311. If these are normal, the central controller sends an initialization start command to the mechanism controller. The mechanism control device controls the mechanism section to perform initial settings such as positioning control of the recording medium, and heats or cools the head temperature if necessary.

First, the temperature control will be described.

After completion of the initial setting, the temperature information of the head 302 acquired by the temperature detector 303 is sent to the temperature comparator 304.

The temperature comparator compares the current temperature Tc with the maximum value Th in the predetermined temperature range, and when Tc is large, sends positive temperature difference information (Tc-Th) to the central control unit. After that, or before that, Tc is compared with the lowest value Tl in the predetermined temperature range, and if Tc is small, the negative temperature difference information (Tl-Tc) is given to the central controller 30.
Send to 1. If neither case applies, 0 is sent as the temperature difference information.

When the temperature difference information is positive, the central controller operates the head cooling device 306 to cool the head. If the temperature difference information is negative, a control command to heat the head is sent to the gradation control device 306 to heat the head.

After completion of the series of temperature control, temperature detection is performed again by the temperature detector, and the above operation is repeated until the temperature difference information by the temperature comparator becomes zero.

When the temperature difference information becomes 0, the temperature control ends and the print engine starts the actual printing.

The temperature comparator and the mechanism controller need not be independent devices, but may be a part of the central controller.

If the maximum value Th and the minimum value Tl in the predetermined temperature range used for comparison in the temperature comparator are the same temperature,
The print engine can always start printing at the same temperature. In particular, if Th and Tl of the second color and thereafter are the temperatures at the start of printing the first color, the temperature at the start of printing the second color and thereafter becomes equal to the temperature at the start of printing the first color, as described with reference to FIG. .

Further, the above-mentioned operation does not necessarily have to be performed after completion of the initial setting required for printing by the mechanism control unit,
It may be done in parallel with the initial setting.

When the initial setting and the head temperature control are performed in parallel, the head temperature control may end before the initial setting, and the actual head temperature before printing may become unstable as in the prior art. is expected. When the head temperature control is performed in parallel with the initial setting, even if the temperature difference information of the temperature comparator becomes 0, it is necessary to perform the printing until the actual printing is started, as shown in FIG.
Monitor the temperature difference information as described in.

The above operation is performed not only at the start of printing the first color but also at the start of printing the second and subsequent colors.

FIG. 5 is a flow chart of temperature control in one embodiment of the present invention.

At 401, the head temperature Tc is detected.

At 402, the maximum value Th at a predetermined temperature is compared with Tc. When Tc is large, the head is cooled at 403, and the process returns to 401 again.

At 404, the minimum value Tl of the predetermined temperature is compared with Tc. When Tc is small, the head is heated at 405, and the process returns to 401 again. In T404, when Tc is large, the head temperature control is ended.

The head temperature control shown in FIG. 5 is performed after the initial setting required for the print engine to print in the mechanism control unit 110 shown in FIG. 4 or in parallel with the initial setting.

FIG. 6 is a block diagram of a printer system according to an embodiment of the present invention.

In FIG. 6, the printer 500 refers to the entire printer. The print engine 100 is the printer 500
A device that performs printing operations. The host controller 510 is a device that sends print data to the printer 500 and sends a print start command. A central control device 501 is a device that controls the entire printer and causes the print engine 100 to perform a recording operation. The external I / F device 502 is a device that controls the I / F between the printer 500 and the host controller 501. The storage device 503 is a device for storing data to be recorded by the print engine sent from the host controller.

The operation of the present invention will be described below with reference to FIG.

The host controller 510 transfers the recording data to the storage device 503 via the external I / F device 502. When all the necessary recording data is sent, the host controller 510 sends a recording start command to the external I / F device 502. The recording start command sent to the external I / F device 502 is decoded by the central controller 501, and the recording start command is sent to the print engine 100.

In FIG. 6, the head temperature control is performed inside the print engine 100 as described with reference to FIG. 4, and is performed independently of other devices. Therefore, the central controller 501
The recording start command from the host controller 510 becomes independent of whether the print engine 100 is under temperature control.

The central control unit 501 may be the same as the central control unit 101 of the print engine in FIG.

[0067]

As described above, according to the present invention, the head temperature at the time when the printer starts printing the second and subsequent colors is stable as in the first color, and as a result, the print density is stabilized and color reproduction is performed. It is possible to improve the sex.

As the temperature control means, the one used for the first color in the conventional printer can be used in the same manner, so that the temperature control means can be constructed without increasing the hardware.

Further, since the temperature control is performed after the printing is started, the printing can be started even if the head temperature deviates from the predetermined temperature range. The host controller can send a print start command regardless of whether or not the printer is performing head temperature control, and can increase the operating rate of the printer system.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of head temperature control according to an embodiment of the present invention.

FIG. 2 is a principle explanatory diagram in the case where the head temperature according to the embodiment of the present invention ends before the end of the initial setting of the mechanical section.

FIG. 3 is a diagram illustrating the principle of another head temperature control according to the embodiment of the present invention.

FIG. 4 is a block diagram of a print engine according to the present invention.

FIG. 5 is a flowchart of temperature control according to the present invention.

FIG. 6 is a configuration diagram of a printer system according to the present invention.

[Explanation of symbols]

101 ... Initial setting of mechanical unit and head temperature control time required for printing with Ye ink, 102 ... Printing time with Ye ink, 103 ... Initial setting of mechanical unit and head temperature control time required for printing with Mg ink, 104
... Mg ink printing time, 105 ... Initial setting of the mechanical unit and head temperature control time required for printing with Cy ink, 106 ... Cy ink printing time, 107
Processing time after printing such as recording paper discharge, 301 Central control unit, 302 Head, 303 Temperature detector, 3
04 ... Temperature comparator, 305 ... Head heating device, 306 ...
Head cooling device, 310 ... Mechanism control device, 311 ... Mechanism part, 401-405 ... Flow chart, 300 ... Print engine, 500 ... Printer, 501 ... Central control device, 502 ... External I / F device, 503 ... Storage device, 51
0 ... Host controller.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidefumi Goto Inventor Hidefumi Goto 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Visual Media Research Laboratory, Hitachi, Ltd. (72) Inventor Yasunori Kobori 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock Company Hitachi Media Media Research Laboratories (72) Inventor Hiroshi Nakamura 1410 Inada, Katsuta City, Ibaraki Prefecture Hitachi Ltd. AV Equipment Division

Claims (3)

[Claims] 1. A thermal transfer printer using a multi-color ink sheet applied in a frame-sequential manner, a central controller, a thermal head, cooling means and heating means for the thermal head, and controlling these cooling means and heating means. It has a head temperature control means, a head temperature detection means, a predetermined temperature range setting means, and an initial setting means for ink sheets, recording paper, etc., and predetermines the head temperature in parallel with the initial setting operation at the start of printing of each color. An operation method of a thermal transfer printer, which is characterized in that the temperature is controlled so as to be within a predetermined temperature range. 2. In addition to the structure according to claim 1, there is a temperature storage means for storing the head temperature at the start of printing of the first color, and the head temperature at the start of printing of the second and subsequent colors by the head temperature control. An operating method of a thermal transfer printer, wherein the temperature is controlled so that the temperature is substantially the same as the data held in the temperature storage means. 3. A printer system including a thermal transfer printer having a print start command receiving device and a printer control device for transmitting a print start command to the thermal transfer printer, in addition to the configuration of claim 1 or 2, When a print start command is transmitted from the print control device during the control of the head temperature, the print operation is started after the print start command is received, and the actual printing is started after the head temperature control is completed. According to this, the central controller receives a print start command from the printer controller even during the head temperature control, and starts the actual printing after the operation of the head temperature control means is completed. Operation method.