JPH0222082A - Thermal transfer type printer - Google Patents

Abstract

PURPOSE:To feed an ink sheet without wastefulness while ink is perfectly used by controlling the feed speed of the ink sheet so as to increase and decrease the same on the basis of the density data of image data. CONSTITUTION:Ink sheets 10-12 printable two or more times are superposed on image receiving paper 1 to be moved at predetermined feed speeds and selectively transferred by thermal heads 3-5 generating heat patterns correspond ing to image recording data to perform recording. The feed speeds of the ink sheets 10-12 are controlled so as to be increased and decreased corresponding to the density distribution of the image recording data. As a result, the ink sheets 10-12 can be fed without wastefulness while the inks thereof are used perfectly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermal transfer printer, and particularly to a thermal transfer printer in which recording is performed by moving an ink sheet capable of multiple printing at a predetermined feeding speed. Related to type printers [Prior technology] Thermal transfer type printers overlap an ink sheet coated with heat-melting ink on an image-receiving paper and move it at a predetermined speed to print a thermal pattern according to image recording information. Recording is performed by selectively transferring ink from the ink sheet using a thermal head that generates . In recent years, in this thermal transfer printer, an ink sheet that can be printed multiple times is used, and running costs are reduced by setting the feeding speed of the ink sheet to 1/n of the feeding speed of the image receiving paper. The so-called 0x mode recording method was published in Japanese Patent Publication No. 62-5891.
This is proposed in Publication No. 7, etc. According to such a 0x mode recording method, ink sheets can be used at high density without complicating the apparatus, and waste of ink sheets can be prevented.

Normal image recording information has an image density distribution from halftone density to maximum density as shown in FIG. Therefore, the ink sheet has an ink composition that can reproduce the maximum image density portion, so that image printing can be performed at all times. In the above-mentioned 0x mode recording method, the feeding speed of ink sheets 1 to 1 is 1/n of the normal feeding speed, that is, 1/n of the feeding speed of the receiver paper.
The maximum image density portion can be reproduced by this constant speed of 1/n.

[Problems to be Solved by the Invention] However, since the ink in the ink sheet is consumed in an amount corresponding to the image density, as mentioned above, in the general 0x mode recording method, the maximum image density part cannot be used. If the ink sheet is fed at a constant speed that can be reproduced, there is still enough ink on the ink sheet for an image with halftone density. Therefore, the unused ink sheets are not fully utilized effectively, and there is still waste.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thermal transfer printer that can utilize ink sheets more effectively and further reduce running costs.

[Means for Solving the Problems] In order to achieve the above object, the present invention involves overlapping ink sheets that can be printed multiple times on image-receiving paper and moving them at a predetermined feeding speed, and applying heat according to image recording information. In a thermal transfer printer that performs recording by selectively transferring ink on the ink sheet using a thermal head that generates a pattern, the feeding speed of the ink sheets 1 to 1 is increased or decreased based on density data of image information. It has a controlled configuration.

[Function] Even in an apparatus having such a configuration, the ink in the ink sheet is consumed and used according to the image density, and the feeding of the ink sheet is adjusted according to the amount of ink consumed. Since the speed is controlled to increase or decrease, the ink sheet is fed so that the ink is completely used and there is no waste.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIGS. 1 and 2, the image receiving paper 1 is placed on the surface of the conveyance section of the feed belt 2, and is then sent.
It is being sent to the left in Figure 1 at a constant speed. On the surface of the conveying section of the conveying belt 2, there are three thermal heads 3 and 4.
．． 5 are arranged side by side in order in the conveyance direction of the feed belt 2 at regular intervals. Pressure rollers 6, 7, and 8 are disposed so as to face each of these thermal heads 3, 4, 5, so that the back side of the feed belt 2 can be seen.

The thermal head 3 is a thermal head that generates a thermal pattern according to yellow image information, and a yellow ink sheet 10 is placed between the thermal head 3 and the feed belt 2.
are arranged so that they are sandwiched between them. The yellow ink sheet 10 is drawn out from a supply reel 10a and taken up on a take-up reel 10b. The thermal head 4 is a thermal head that generates a thermal pattern according to magenta image information, and is arranged so that the magenta ink sheet 11 is sandwiched between the thermal head 4 and the feed belt 2. The magenta ink sheet 11 is drawn out from the supply reel lla and taken up on the take-up reel llb. The thermal head 5 is a thermal head that generates a thermal pattern according to cyan image information, and is arranged so that the cyan ink sheet 12 is sandwiched between the thermal head 5 and the feed belt 2.

The cyan ink sheet 12 is drawn out from a supply reel 12a and taken up by a take-up reel 12b.

Here, the feeding speed of each of the ink sheets 10, 11, and 12 is controlled to vary based on a control signal from an ink sheet feeding speed control circuit (not shown). The ink sheet feeding speed control circuit is equipped with an image data detection circuit and a comparator, and the ink sheets 1-10, 11, and 12 are fed in response to the density data of the image recording information detected by these. The speed is now set. At this time, if the percussion motor for feeding the ink sheet is a pulse motor, its driving frequency will be varied and controlled by the above circuit.

The feeding speed of the ink sheet during n-times mode recording is
For maximum image density, 1/n of the feed speed of receiver paper 1
In other words, the pixel length is set to 1/n of the pixel length per recording time for one recording pixel, and for intermediate image density, it is reduced according to the density ratio to the maximum image density. The feed rate will be controlled and set to a feed rate of less than 1/n.

In this case, the density data of the image information detected by the image data detection circuit is obtained by comparing the maximum image density of the entire image with the maximum density in one line.

Normal image recording information has an image density distribution from halftone density to maximum density as shown in FIG. In this embodiment, the feeding speeds of the ink sheets 10, 11, and 12 are controlled to vary in accordance with the density distribution of the image recording information. For example, when transferring an ink sheet in 10x mode, if the image density of image recording information in one line is 1/2 of the maximum image density,
This 1/2 image density is detected by the image data detection circuit, and based on the control signal from the ink sheet feeding speed control circuit, the feeding speed of the ink sheets 10, 11 and 12, which is normally 1/10, is changed to 1/10. 20. In this case, the ink in each ink sheet 10, 11, 12 is consumed and used in accordance with the image density, but the ink in each ink sheet 10, 11, 12 is consumed and used in accordance with the amount of ink consumed and used. 12 feed speeds are controlled to increase or decrease. Therefore each ink sheet 10°11.12
In this case, the ink is completely used, but the ink is sent without any waste.

The density data of the image information detected by the image data detection circuit includes data obtained by comparing the maximum image density of the entire image and the maximum density of one line as in the above embodiment, as well as data obtained by comparing the maximum image density of the entire image with the maximum density of one line. The data obtained by calculating the average image density and comparing it with the maximum image density may be used. If density data based on such average image density is used, it is possible to form a soft image by averaging the data during image printing, for example.

Further, the feeding speed of the ink sheet may be determined by using a predetermined coefficient on the density ratio of the maximum density in one line to the maximum image density of the entire image. By using such density data, it is possible to maintain a good printing effect even if the ink sheet is heated once and its transfer characteristics are somewhat degraded.

Furthermore, the density data of the image information can be obtained from images of 1 to n lines. If such density data is used, the relationship between image density and ink sheet feeding speed can be maintained even better, and image quality can be made more stable.

[Brief explanation of the drawing]

FIG. 1 is an explanatory side view showing an example of a thermal transfer printer to which the present invention is applied, FIG. 2 is a partially enlarged view of the apparatus shown in FIG. 1, and FIG. 3 is an illustration of image recording information. 3 is a diagram showing image density distribution for each line. FIG. 1... Image receiving paper, 3, 4.5... Thermal head, 1
0.11.12... Ink sheet.

Claims (1)

[Claims] Ink sheets that can be printed multiple times are stacked on image-receiving paper and moved at a predetermined feeding speed, and the ink on the ink sheets is selectively transferred using a thermal head that generates a thermal pattern according to image recording information. In thermal transfer printers that record by
A thermal transfer printer characterized in that the feeding speed of the ink sheet is variable controlled based on density data of image information.