JPS5968277A - Paper-positioning method of color printer - Google Patents

Abstract

PURPOSE:To enable to obtain a clear color image without any bad registering of starting positions for printing in respective colors in the same page, by a method wherein a mark is printed on a part of a paper, and the paper is reversely fed until the mark is detected in the process of reciprocal printing. CONSTITUTION:When printing is started by turning on a switch, a platen roller 3 is forwardly rotated to feed the paper 1 in the direction of an arrow A, printing in cyan color is started, and when the paper is fed by a distance d1, the marks m1-m5 are successively printed for each one step of a stepping motor. When printing in cyan color is completed, the platen roller is reveresly rotated at a high speed, and when a detector 10 detects the mark m5, deceleration is started, further deceleration is conducted each time the mark m1, m2 is detected, and the roller 3 is stopped when the mark m1 is detected. From this position, printing in magenta color is conducted while rotating the roller 3 forwardly, and then printing in yellow is similarly conducted. Accordingly, bed registering in printing in respective colors in the same page can be prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper positioning method for a color printer that performs color printing on paper.

Some color printers have three colors: cyan, magenta, and yellow.
There is a color printer that uses an ink ribbon on which colored inks are repeatedly applied and thermally transfers the three colored inks onto Ml paper to create seven colors using a subtractive color method.

Is it possible to produce color images with a color printer like this?
In order to obtain this, it is necessary that the cyan, magenta, and yellow color images completely intersect. Here, a conventional image alignment method used in the above-mentioned color printer will be explained with reference to FIG. In this figure, 1 is a sheet of paper, and the sheet of paper 1 is brought into contact with the outer periphery of a platen roller 3 and is conveyed by this platen reeler 3. in this case,
Feed holes are provided on both sides of the paper 40,
This feed hole is engaged with a feed pin 3a%3PL of the platen roller 3. 2 is an ink ribbon to which diasmagenta and yellow inks are sequentially applied; ). 4 is a thermal head provided close to the left side of the platen roller 3, and it
and is brought into pressure contact with the ink ribbon 2.

In the figure, points FLI and FL2 are the print start position and print end position of paper 1, respectively, and the length between points al and a1 is the length of one print section. Also, the area between dots and -b on the ink ribbon 2 (approximately one length) is the area where cyan ink is applied, and the area to the right between the dots and -b on the ink ribbon 2 is a section where cyan ink is applied. Magenta, yellow, cyan, magenta, etc. with the same interval width.
Colored ink is applied sequentially. In addition, in the above-described configuration, the platen roller receives power from the stepping motor (m) and can rotate in either the clockwise or counterclockwise direction, and the paper 1 is transported by the supply pulse to the stepping motor. is controlled.

Now, in the above-described configuration, when the platen roller 3 rotates clockwise (forward rotation), the paper 1 and the ink ribbon 2
are conveyed while being overlapped on the lower surface of the platen roller 3, and at the same time, the thermal pad 4 presses against the paper 1 and the ink ribbon 2 to print cyan on the paper 1. When the printing end position at of the paper 1 and the point b2 of the ink ribbon 2 reach the position of the thermal head 4, the pressure contact of the thermal head 4 is released 17, and the platen roller 3 is moved counterclockwise while the ink ribbon 2 is stopped. The sheet 1 is rotated (reversely) to convey it in the direction of the broken line arrow B. In this case, the amount of drive of the platen roller 3 in the reverse direction is made equal to the body jIM of one page in the forward direction. In other words, the number of pulses supplied to the stepping motor is the same as during normal rotation. As a result, the printing start position fFjal of paper 1 reaches the thermal head position 40 INJ again. At this time, there are 20 ink ribbons.

Since is located at the position of the thermal head 4, magenta ink is applied to the portion of the ink ribbon 2 facing between the points PL H & 2 of the paper 1 at this point. Then, repeat the above-mentioned operation and move to point a I on paper 1.
& Printing with composite colors of cyan, magenta, and yellow between 2
conduct. In this way, in the color printer described above, color printing is performed by reciprocating the paper 1 three times,
Positioning of the paper 1 (that is, image alignment) during each reciprocation is performed by controlling the number of pulses supplied to the stepping motor. There is a color printer that rotates the cut paper three times while keeping it in contact with the outer periphery of the platen roller 3, thereby performing a printing operation similar to the above case (three back and forth printing), but in this case as well, the image is The alignment is performed by controlling the number of pulses supplied to the stepping motor.

By the way, in the conventional image alignment method for color printers described above, the amount of drive of the platen roller for aligning the paper is predetermined by the number of pulses.
If the feed holes of the paper are deformed due to reciprocating movement, or if the paper itself is deformed due to temperature, humidity, etc., the paper conveyance will be misaligned, and as a result, the printing position of each color will be misaligned, resulting in a clear color image. The disadvantage was that it was not possible to obtain

In view of the above-mentioned circumstances, the present invention provides a paper positioning method for a color printer that can obtain a clear color image without color shift. In the process of printing the previous page, a mark is printed on a part of the page l1, and the printing start position of the paper is set by detecting this mark.

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

2 and 3 are diagrams each showing a printing example in one embodiment of the present invention, and FIGS. 4(a) and 4(b) are diagrams each showing the mechanical configuration of this embodiment. In these figures, the same reference numerals are given to the parts corresponding to those in FIG. 1, and the explanation thereof will be omitted. Further, this embodiment is an embodiment in which the present invention is applied to a color printer that performs color printing by moving paper back and forth three times.

In FIG. 2, g, , ex are perforations, and the space between these perforations L, /l* is page 1p.

M is a mark printed by the method described below, and is printed on page 1.
Distance hawk from printing start position a, on the left female part of p.

It is printed separately. This mark MG;Jm3 As shown in the figure, it consists of five lines m, ~m, each having a length of 2 to 3 gates, printed along the longitudinal direction of the paper 1, and the lines m, ~m. The distance between the two rollers corresponds to the conveying distance of the paper 1 corresponding to one step of the driving stepping motor.

In FIGS. 4(A) and 4(B), 10 is a detector for detecting the mark M, and is composed of 7 reflective type sensors. In this case, the detector 10 detects the surface of the paper 1 (mark M
Light is irradiated onto the left end M; of the surface (on which is printed) and the reflected light is received, and 19m1 to m6 forming the mark M are detected by the reflective light needle. The positional relationship between the detector 10 and the thermal head 4 is as shown in FIG. 4(b) when the detector 10 detects the line m.
Printing start position fF? , &I are set to face the heating resistor of the thermal head 4. In addition, in FIG. 4, the ink ribbon and its conveyance system are not shown.

Next, the 17+ work of this embodiment will be explained. First, the operator sets the printing start position t? Set so that 2a+ faces the heating resistor of the thermal head 4. Next, when the operator presses a print button (not shown), the stepping motor is driven, and the platen roller 3 rotates in the counterclockwise H1 direction (forward rotation) as shown in FIG. 1-'''/1 side begins to be conveyed upward. At this time, printing of cyan, the first color, starts on page 1p, and paper 1 is conveyed a distance of 4 degrees from the printing start position a1. At this point, a line m is printed on the left end of the Nip, and thereafter, a line ITII.m3.m4.ml+ is printed every time the stepping motor takes one step.

In this case, fe I'll d + is set by the number of pulses supplied to the stepping motor. , so that

Then, as the paper 1 is further conveyed and all cyan color printing on page 1p is completed, the platen roller 3 starts to rotate in reverse (see FIG. 3B), and the paper 1 is conveyed in the reverse direction.

At this time, the platen roller 3 rotates in the opposite direction at high speed, and the next color (
Magenta) Shorten the windless time until printing starts. When the detector 10 detects the line m5, the rotational speed of the platen roller 3 is decelerated, and from then on, the detector 10 detects the line m5.
4, ml, m! The rotational speed of the platen roller 3 is further reduced each time mmt is detected, and the platen roller 3 is stopped when the detector 10 detects mmt (FIG. 4(b)). From this position of the paper 1 (the position shown in FIG. 4(B)), the platen roller 3 rotates normally, and printing of the next color, magenta, is started. Next, when the magenta printing is completed, the paper 1 is conveyed in the reverse direction until the detector 10 detects Hml, and then the platen 4 is rotated forward to print the yellow color. I do. Then, when the yellow printing is completed, the color printing is completed on page 1], and the paper 1 is further moved to the ejection side (see Fig. 4).
→ arrow direction) until the printing start position of the first page is at the position of the heating resistor of the thermal head 4.

The conveyance amount of the paper 1 in the beginning of the paper is controlled by controlling the number of pulses supplied to the stepping motor.

In this embodiment, the mark M is printed when the first color is printed, but instead, the mark M of the page is printed when any color is printed in the printing process of the previous page. It's okay.

As explained above, according to the present invention, a mark is printed on a part of the paper, and during the reciprocating printing process, the paper is conveyed in reverse until the mark is detected, so that the feed hole of the paper is deformed. Even if the paper itself is deformed due to temperature, humidity, etc., the printing start positions of each color on the same page will not shift, making it possible to obtain extremely clear color images.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the layout of a conventional color printer. FIGS. ) are schematic configuration diagrams of the tJM structural configuration in the same example. 10...Detector, M...Mark, ml~I
J. Curve (mark).

Claims (1)

[Claims] In a paper positioning method for color printers that sequentially transports and prints in border colors on the same page portion of paper that is transported back and forth multiple times, when printing the first color in one page of color printing or on the page before the previous page. During the printing process, a mark is printed on a portion of the page, and a detector is provided to detect the mark on the paper supply side of the printing section, and every time printing of each color is completed, except when printing the last color of the page. , pulling the paper back until the detector detects the mark;
A paper positioning method for a color printer characterized by printing the next color from this pulled back position.