JP2550874B2 - Printout method of serial printer and its control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printout method for a serial printer and a control device therefor, and more particularly, to a printout method for changing the position of a recording material in the sub-scanning direction.
The present invention relates to a serial printer printout method and a control device therefor capable of reducing streak-like density unevenness that occurs in parallel with the main scanning direction.

[0002]

2. Description of the Related Art Conventionally, in this type of serial printer, density unevenness which occurs in parallel with the main scanning direction due to an error in the amount of change when changing the relative position of the recording material and the print head in the sub-scanning direction, in particular, In order to prevent a gap between images, one part of the image on the recording material formed by one scanning in the main scanning direction and one image on the recording material formed by the next scanning in the main scanning direction Part of the image on the recording material formed by one scan in the main scanning direction is slightly enlarged, or one scan in the main scanning direction is performed so that a minute overlap occurs in the adjacent portion. A part where an image is formed by either scanning is provided adjacent to a part of the image formed on the recording material by the next scanning in the main scanning direction. There are known techniques for preventing gaps.

In Japanese Patent Laid-Open No. 63-69657, when a print font is vertically expanded in a serial printer, the line feed pitch is made slightly narrower than the print height of one line to print the upper line and the lower line. There is disclosed a technique for preventing the occurrence of a gap at the line feed portion based on the cause such as the non-uniformity of the backlash of the line feed mechanism by overlapping and.

In Japanese Patent Laid-Open No. 2-235670, when a print font is vertically expanded in a serial printer, data for correcting a line feed width to a desired value is input, and a line feed obtained before the line feed is obtained. It is described that the width data is corrected by the correction data and the paper feed mechanism is controlled so as to feed the paper by an amount corresponding to the corrected newline width data.

[0005]

In the technique described in the first known example, a part of the image on the recording material formed by one scanning in the main scanning direction and the next main scanning direction. In the adjacent portion of a part of the image formed on the recording material by the scanning of 1, the part where the image is formed overlaps. Therefore, when there is a correlation between the number of times an image is formed and the density of the image, particularly when a light-transmissive ink is used in image formation with ink,
There is a problem that streak-like density unevenness occurs in the overlapping portion in parallel with the main scanning direction.

On the other hand, in the technique described in the second known example, since the line feed width is corrected by the correction data, such a problem does not occur, but in the case where the backlash of the line feed mechanism changes, Has the problem that the correction amount must be changed each time.

The present invention is intended to solve such a problem of the prior art, and a part of the image on the recording material formed by one main scan and the next main scan direction. Dispersing the density unevenness generated in the adjacent portion of the image on the recording material formed by scanning in the sub-scanning direction reduces the streak-like density unevenness generated in the main scanning direction and makes it inconspicuous. The purpose is to do.

[0008]

The present invention is intended to achieve the above-mentioned object by adopting the following configuration.

A print head drive section for driving the print head, and an LF / SP for driving the print head in the main scanning direction and the recording material in the sub scanning direction perpendicular to the main scanning direction.
A part of the image adjacent to the recording material by repeatedly forming a part of the image on the recording material by scanning the print head in the main scanning direction and moving the recording material in the sub-scanning direction. In a serial printer in which the entire image is formed by sequentially forming the image, the relative movement amount of the print head in the sub-scanning direction is made smaller than the width of the image formed by one main scanning, and the overlapping is thereby performed. In the area where an image can be formed, an image forming portion by the previous main scanning and an image forming portion by the subsequent main scanning are alternately provided at regular intervals in the main scanning direction. There is. This aims to achieve the above-mentioned object.

[0010]

FIG. 1 shows the basic configuration of the present invention. A serial printer to which the present invention is directed includes a print head drive unit 7 that drives a print head, and an LF / SP that drives a print head in a main scanning direction and a recording material in a sub scanning direction perpendicular to the main scanning direction. Motor drive unit 8
A part of the image adjacent to the recording material is repeated by repeatedly forming a part of the image on the recording material by scanning the print head in the main scanning direction and moving the recording material in the sub-scanning direction. By sequentially forming, the entire image is formed.

In such a serial printer, for example, the LF / SP motor drive unit 8 is set to 1 from the print width of one pass.
A line feed is performed with a width of a few bits, and the print data processing unit 6 is provided to perform the following processing.

Further, a divide-by-2 counter 9 is provided to count a clock synchronized with the head data and output a signal indicating whether the input head data is even-numbered or odd-numbered from the path end. Bit shift register 10
When the input head data is an even number (or an odd number) from the pass edge, the recording material suction direction edge bit data is stored and output after one pass.

A first selector 11 is provided so that when the input head data is an odd number (or even number) from the pass end, the recording material suction direction end bit data is output as it is as the recording material suction direction end bit print data. , The recording material suction direction end bit data is masked at the even number (or odd number), and the second selector 12 is provided. When the input head data is at the even number (or odd number) from the pass end, the shift register 10 The output is output as the printing material discharge direction end bit print data, and when it is an odd number (or even number), the recording material suction direction end bit data is masked.

Therefore, with respect to a region where images can be formed in an overlapping manner by two successive main scans, an image forming portion by the previous main scan and this image forming are formed at regular intervals in the main scanning direction. Since a portion and an image forming portion by a main scanning after a certain interval in the sub scanning direction are alternately provided, a part of the image on the recording material formed by one main scanning and the next main scanning. The density unevenness that occurs in the adjacent part of the image on the recording material formed by scanning in the direction
By dispersing in the sub-scanning direction, streak-like density unevenness occurring in the main scanning direction can be alleviated and made inconspicuous.

[0015]

Embodiments of the present invention will be described below with reference to FIGS. 2 is a block diagram of a serial printer showing an embodiment of the present invention, FIG. 3 is a circuit diagram of a print data processing unit, FIG. 4 is an example of a print pattern according to the present invention, and FIG. 5 is a timing chart of the print data processing unit. FIG. 6 shows the printing result according to the present invention.

The embodiment shown in FIG. 2 has a control unit 1, an interface unit 2, an operation panel 3, a detection unit 4, a power supply circuit unit 5, a print data processing unit 6, and a print head drive unit 7. ,
It has a schematic structure including an LF / SP motor drive unit 8. This will be described in more detail below.

The control unit 1 controls the entire printer,
Outputs 3-bit print data to the print data processing unit 6. The interface unit 2 communicates between the external data processing device and the control unit 1. The operation panel 3 inputs various operation information. The detection unit 4 detects the paper position and the paper shortage, and outputs it to the control unit 1. The power supply circuit unit 5 supplies power to each unit. The print data processing unit 6 processes the data sent from the control unit 1 as shown in FIG. 5, and outputs it to the print head drive unit 7.

The print head drive unit 7 uses the dot pattern shown in FIG. 4 for the data input from the print data processing unit 6 by using the print head 7A having four dot rows arranged in parallel with the sub-scanning direction. Print on the recording material. The LF / SP motor drive unit 8 sucks and discharges the recording material, and
The print head is scanned in the main scanning direction (hereinafter referred to as a pass), and the recording material is moved by 3 dots in the sub scanning direction each time one pass is completed.

In the circuit diagram of the print data processing section shown in FIG. 3, the divide-by-2 counter 9 inputs the strobe signal STROBE of the print data, and in one pass, the odd-numbered data (hereinafter odd number) from the print start end is inputted. Called column data)
If so, an ODD signal of "1" is output, and if it is an even number (hereinafter referred to as even column data), an ODD signal of "0" is output.

The 2-bit shift register 10 receives the output ODD signal of the divide-by-2 counter 9 and the output of the NOR circuit 13, and if it is not the last pass for one recording material, the even-numbered column data for one pass The print inhalation direction end print data a3 is stored and is output to the d1 selector 12 as the print ejection end dot print data of the even-numbered column data in the pass subsequent to this one pass.

The d4 selector 11 masks the output of the OR circuit 14 with the print suction direction end data a3 of the even-numbered column data of the non-last pass for one sheet of recording material, and the even-numbered column data of the sheet suction direction. Output as end data d4. The d1 selector 12 receives the output of the divide-by-2 counter 9 and outputs the output of the 2-bit shift register 10 to the print head drive unit as the end dot data d1 of the paper discharge direction of the even column data.

The NOR circuit 13 outputs a signal L from the control section, which indicates that the data is the data for the final pass for one recording material.
ASTLINE and paper suction direction end print data a3
If it is not the final pass for one sheet of recording material,
The sheet suction direction end data is output to the 2-bit shift register 10. The OR circuit 14 uses the LASTLI signal from the control unit.
The NE signal and the ODD signal are received, and a signal for masking the sheet suction direction end data of the even-numbered column data that is not the final pass for one recording material is output to the d4 selector 11.

In the example of the print pattern according to the present invention shown in FIG. 4, the parts 15, 16 and 17 are respectively 1,
The print dot patterns for the second and third passes are shown. In the figure, d1 to d4 indicate the signal lines in FIG. 3 from which the dot data for that portion are output, and the numbers in parentheses indicate the order in which printing is performed.

In the timing chart of the print data processing unit shown in FIG. 5, an (m) represents digital print data sent from the control unit. However, an
Is a1 to a3, and m is an integer of 1 to 12.

In the print result according to the present invention shown in FIG. 6, X indicates the boundary portion of the path. In the portion B to which the present invention is not applied, it is shown that streak-like density unevenness occurs in a part of the overlapping portion of the image on the recording material due to two scans in the main scanning direction. On the other hand, the print result according to the present invention shown in A shows that the density unevenness generated in the main scanning direction is dispersed in the sub-scanning direction, so that the density unevenness is alleviated and becomes conspicuous. There is.

[0026]

As described above, according to the present invention, a part of the image on the recording material formed by one scanning in the main scanning direction and the next scanning in the main scanning direction are formed. The density unevenness that occurs in a portion adjacent to a part of the image on the recording material is dispersed in the sub-scanning direction, so that the streak-like density unevenness that occurs parallel to the main scanning direction is alleviated and becomes inconspicuous. It is possible to provide a print output method of a serial printer and a control device thereof that have excellent effects.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a circuit diagram of a print data processing unit.

FIG. 4 is a diagram showing an example of a print pattern according to the present invention.

FIG. 5 is a timing chart of a print data processing unit.

FIG. 6 is an explanatory diagram showing a printing result according to the present invention.

[Explanation of symbols]

 6 Print Data Processing Section 7 Print Head Drive Section 8 LF, SP Motor Drive Section 9 2 Frequency Division Counter 10 2 Bit Shift Register 11 First Selector 12 Second Selector

Claims (1)

(57) [Claims] 1. A print head drive unit for driving a print head, and an LF / SP for driving the print head in a main scanning direction and driving a recording material in a sub scanning direction perpendicular to the main scanning direction.
A motor drive unit is provided, and the formation of a part of the image on the recording material by the scanning of the print head in the main scanning direction and the movement of the recording material in the sub scanning direction are repeated and controlled to control the recording material. In a serial printer including a control unit for sequentially forming a part of adjacent images and controlling output of the entire image, the control unit performs a line feed with a width that is 1 bit smaller than a print width of one pass by the print head. To the LF / SP
It has a narrow line feed control function that drives and controls the print head unit via a motor drive unit, and counts clocks synchronized with head data, and the input head data is an even number or an odd number from the path end. And a 2-bit shift register for storing the bit data of the recording material suction direction end and outputting it after one pass when the input head data is an even number (or an odd number) from the pass end. , When the input head data is an odd number (or even number) from the path end, the bit data in the recording material suction direction is output as it is as the bit data in the recording material suction direction, and when it is an even number (or an odd number), the recording material suction is performed. A first selector that masks the direction end bit data is provided, and when the input head data is an even (or odd) number from the path end, The output of the shift register is output as the recording material discharge direction end bit print data, and at the time of an odd number (or even number), a print data processing unit having a second selector for masking the recording material suction direction end bit data is provided. Equipped with a print output control device for serial printers.