JPH01249473A - Printer device - Google Patents

Abstract

PURPOSE:To obtain a high-quality printing, by detecting the lower end position of preceding lines, calculating an error amount of the detected position from the lower end position obtained in a proper paper feeding, and performing a correction paper feeding according to the error amount. CONSTITUTION:A CPU 11 shifts a carriage 31 and conducts a printing for one line on paper 33 by a printing head 21. While the carriage 31 returns to a printing start position, a sensor 22 scans the paper 33, which has been fed to a next line, in a carriage return direction. If the paper 33 is properly fed to the next line, detection signals are outputted from, for example, upper 4 elements 22a of 8 elements 22a forming the sensor 22. On the other hand, if a very little misregistration occurs, detection signals are outputted from the other range of the elements 22a. The CPU 11 calculates the error amount according to the comparison between the output state of the respective elements 22a and that of the respective elements 22a obtained in a proper feeding of the paper 33. Then, on the basis of the error amount the paper 33 is corrected to be fed to a proper printing position, and the printing for the appropriate one line is started.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a printer device suitable for graphic printing.

(Prior art) Unlike normal character printing, which has margins between lines, graphic printing connects dots in the vertical direction (paper feeding direction) by narrowing the line spacing, and prints continuous dot patterns over multiple lines, such as figures. is printed. In this case, in order to form a continuous dot pattern as described above, it is necessary to feed the paper with high precision at a value of one-tenth to one-tenth of the dot pitch. In other words, in graphic printing, after printing one line, the bottom dot of the previous line is connected to the top dot of the next line, that is, the bottom dot of the previous line is connected to the top dot of the next line. To connect,
The paper must be fed slightly without leaving any space between lines.

However, paper feeding is generally performed by a platen that is rotationally driven by a paper feeding motor, and the slippage of the paper set on the platen, changes in the thickness of the paper, and even the rotational movement of the paper feeding motor are transmitted to the platen. There is a problem in that misalignment is likely to occur due to rattling of various parts such as gears and rollers. Therefore, when printing graphics, the dots in the vertical direction of each line do not connect neatly, resulting in a disadvantage that the quality of printing as a graphic image deteriorates.

In addition, not only for graphic printing, but also when the dot pitch becomes narrower in the future as higher density and resolution progress, it will not be possible to obtain high-quality printing results with conventional paper feeding accuracy. It disappears.

(Problem to be Solved by the Invention) As mentioned above, conventionally, when printing a dot pattern that connects vertically (paper feeding direction) across multiple lines of figures, etc., there is a drawback that the printing quality deteriorates. Yes.

The present invention has been developed in view of the above points, and it is possible to obtain high-quality printing results even when printing dot patterns that are connected in the vertical direction (paper feeding direction) over multiple lines of figures, etc. The purpose is to provide a printer device that can.

[Structure of the Invention] (Means for Solving the Problems) That is, a printer device according to the present invention is a printer device in which a carriage carrying a print head performs printing by reciprocating in parallel with a platen. A detection means is provided for scanning the paper fed to the printing position of the next line in the moving direction of the carriage and detecting the lowest end position of the previous row, when the lowest end position of the previous row is detected by the detection means, The amount of error between the detected position and the lowest position that would be obtained if the paper was correctly fed to the next line's printing position is calculated, and based on this error amount, the paper that has been fed to the next line is moved to the correct printing position. It is configured to perform correction feeding.

(Operation) According to the above configuration, when the paper is fed to the printing position of the next line, if the paper is not fed correctly, it is corrected and fed to the correct position.

Therefore, in the case of graphic printing, for example, dots in the vertical direction (paper feeding direction) are connected accurately, making it possible to obtain high-quality printing results.

(Embodiment) Hereinafter, a printer device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the circuit configuration. The CPU II, which controls the entire device, has a system bus 12
ROM 13, RAM 14, interface 15, motor drive circuit 1B, head drive circuit 17,
A quantization circuit 18 is connected to each.

The ROM 13 stores various data necessary for printing, including the printing control processing program shown in FIG. R.A.
M14 temporarily stores print data.

The interface 15 sends and receives data to and from a host device (not shown). Motor drive circuit 16 drives paper feed motor 19 and carriage motor 20. The paper feed motor 19 and carriage motor 20 are, for example, pulse motors. Head drive circuit 17 drives print head 21 . The print head 21 is, for example, a thermal head. The quantization circuit 18 quantizes the output signal (analog signal) of the sensor 22, which will be described later.

FIG. 2 is a plan view showing the configuration of the printing mechanism section of the same embodiment, and the carriage 31 on which the print head 21 is mounted moves in the axial direction of the platen 32. As the carriage 3I moves in a predetermined direction (from left to right in this case), the print head 21 comes into contact with the paper 33 via an ink ribbon (not shown), and uses the heat of the heating element 21a to transfer ink from the ink ribbon to the paper 33. Welded to form dot characters. When the print head 21 finishes printing one line, the carriage 3
1 moves in the return direction (here, from right to left) and returns to the printing start position.

Here, a sensor 22 is provided on the carriage 31. This sensor 22 is a fraction of the size of the dot.
It detects a minute range of less than a tenth of
As shown in FIG. 3, a plurality of elements 22a consisting of a pair of light-emitting elements and a light-receiving element are arranged in one row in the paper feed direction, and when printing, the paper 33 that has been fed to the next line is scanned in the carriage return direction. do. In the example shown in FIG. 3, 8
Two elements 22a are arranged.

Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG.

FIG. 4 is a flowchart for explaining the print control processing operation. First, the CPU II moves the carriage 31 and prints one line on the paper 33 using the print head 21 (Steps Sl). Then, when the CPU II finishes printing this one line, it feeds the paper 33 to the printing position of the next line (step S2), returns the carriage 31 to the printing start position (carriage return), and prepares for printing the next line (step S2). S3).

Here, when the carriage 31 returns to the print start position, the sensor 22 provided on the carriage 31 scans the paper 33 that has been fed to the next line in the carriage return direction. In this case, the sensor 22 is formed by arranging, for example, eight elements 22a, as shown in FIG. 3, with the lowest end position of the previous row of the sheet 33 that has been fed to the next row as the boundary. Therefore, when the paper 33 is fed to the printing position of the next line, the lowest dot of the previous line is detected by the sensor 22 during graphic printing.

As a result, when the CPU II performs a carriage return in step S3, when the detection of the lowest dot is confirmed by the signal of the sensor 22 inputted through the quantization circuit 18 (step S4), the CPU II detects the lowest dot according to the detected position of the lowest dot. Paper position correction is performed (step S5).

That is, when the paper 33 is correctly fed to the next line, for example, the eight elements 2 constituting the sensor 22
It is assumed that detection signals are output from the fourth elements 22a from the top among the elements 22a. On the other hand, if a slight positional shift occurs when the paper is fed, a detection signal will be output from the elements 22a in another range.

Therefore, when the sensor 22 detects the lowest position of the previous row, the CPU 11 determines the output state of each element 22a at that time and the output state of each element 22a that would be obtained if the paper 33 is correctly fed to the printing position of the next row. The amount of error is calculated by comparing it with the output state. That is, when the paper 33 is fed to the next line printing position, for example, the third element from the top.

If there is an output signal from element 22a, the amount of error is determined by element 228.
It turns out that it is for one piece. Then, the CPU 1l, which has calculated the amount of error in this way, corrects and feeds the paper 33 that has been fed to the next line based on the amount of error to the correct printing position, and then starts printing one line of that line. (Step S6).

On the other hand, in the case of normal character printing rather than graphic printing, there is a margin between lines, so the lowest dot is not detected in step S4.

In this case, the CPU II performs printing of the next line after correcting and feeding only the logical shortage (to be described later) (step S7).

By the way, in the case of graphic printing, step S5
In this case, the corrected feed is executed according to the output state of each element 22a, but the direction of the corrected feed in this case is determined according to the positional deviation state at that time, that is, depending on whether the deviation is more or less. It is different for each line printed. This difference in the direction of corrected feeding is caused by the paper feeding motor 19
This causes the paper feeding mechanism such as the platen 32 and the like to become rattled, resulting in a deterioration of paper feeding accuracy. Therefore, in order to keep the corrected feeding direction always constant and to prevent the deterioration of paper feeding accuracy as described above, the following operation is actually performed.

That is, when feeding the paper in step S2, the paper 33 is fed in advance by a predetermined amount to the printing position of the next line. As a result, in the reprinting of graphic printing and normal character printing, a print shift that is smaller by the above-mentioned predetermined amount occurs. Therefore, the direction of the correction feed executed in step S5 or step S7 is always the direction that eliminates the above-mentioned small print deviation, that is, the normal paper feed direction, and the paper feed accuracy is not deteriorated. In this case, in step S5, an error amount is calculated taking into consideration the logical shortfall of the predetermined amount, and corrective feeding is executed based on this. On the other hand, in step S7, step S
In step 2, there is a shortage in paper feed by the predetermined amount in advance, so as described above, a correction feed is performed by the logical shortfall of this predetermined amount.

In the case of normal character printing, it is known in advance whether or not to connect dots in the vertical direction (paper feeding direction), so the series of processes from step S4 to step S7 is omitted. As before, the configuration may be such that paper is fed by a certain amount until the next line.

In this way, when the paper is fed to the printing position of the next line, if the paper is not fed correctly, it is corrected and fed to the correct position. Therefore, even when printing dot patterns that are connected in the vertical direction (paper feeding direction), such as graphics printing, for example,
The front and rear dots are connected accurately, allowing you to obtain high-quality printing results.

Generally, such unidirectional printing is used when printing, such as graphic printing, in which the connection of dots in the vertical direction is important.

[Effects of the Invention] As described above, according to the present invention, in a printer device in which a carriage carrying a print head performs printing by reciprocating in parallel with a platen, paper is fed to the printing position of the next line on the carriage. A detection means is provided that scans the paper in the moving direction of the carriage and detects the lowest end position of the previous row, and when the lowest end position of the previous row is detected by this detection means, the detected position and the paper are correctly aligned to the next row. The amount of error from the bottom edge position obtained when the paper is fed to the printing position is calculated, and based on this amount of error, the paper that has been fed to the next line is corrected and fed to the correct printing position. Vertically across multiple lines (paper feed direction)
High-quality printing results can be obtained even when printing dot patterns that are connected to each other.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration according to an embodiment of the present invention, FIG. 2 is a plan view showing the configuration of the printing mechanism section of the same embodiment, and FIG. 3 explains the configuration of the sensor of the same embodiment. FIG. 4 is a flowchart for explaining the operation of the embodiment. 11...CPU, 12...System bus, 13...
・ROM. 14...RAM, 15...Interface, 1B
...Motor drive circuit, 17...Head drive circuit, 1
8... Quantization circuit, 19... Paper feed motor, 20.
... Carriage motor, 21... Print head, 21a
...Heating element, 22...Sensor, 22a...Element, 31...Carriage, 32...Platen, 33...
...Paper. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1ll Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a printer device in which a carriage carrying a print head performs printing by reciprocating in parallel with a platen, the carriage moves the paper that is provided on the carriage and has been fed to the printing position of the next line. scan in the direction,
A detection means for detecting the lowest end position of the previous line, and when the lowest end position of the previous line is detected by this detection means, the detected position and the maximum value obtained when the paper is correctly fed to the printing position of the next line. The present invention is equipped with a calculation means for calculating the amount of error with respect to the lower end position, and a correction feeding means for correcting and feeding the paper that has been fed to the next line to the correct printing position based on the amount of error obtained by the calculation means. Characteristic printer device.