JPH0747740A - Serial printer - Google Patents

Abstract

PURPOSE:To carry out final printing by conveying a cutform paper by the distance shorter than the width of one printing band by a printing head by a method wherein the printing of final printing band is carried out on the cutform paper, which is conveyed with a final printing band conveying means on the basis of drawing data. CONSTITUTION:When a paper sensor 18 is turned ON, the detection of the front end of a cutform paper is judged, resulting in starting the counter X 23a of a RAM 23 so as to count the number of the driving steps of a feeding motor 30. When the counted value reaches the predetermined value or more, the rotation of the feeding motor 30 is stopped, a head 11 is scanned once to the direction normal to the conveying direction of the cutform paper and, at the same time, prints one line by passing one line dot data from a print buffer 28 through a head controller 27 to the head 11. Next, the remaining one line dot data drawn on the print buffer 28 is outputted through the head controller 27 to the head 11 in outer to carry out the final printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prints on cut-sheet paper by scanning the print head in a direction orthogonal to the conveyance direction of cut-sheet paper, such as a wire dot printer or ink jet printer. Regarding serial printers.

[0002]

2. Description of the Related Art Generally, in a wire dot printer, an ink jet printer or the like, a print head is mounted on a carrier, the carrier is scanned in a direction orthogonal to the paper transport direction, and the print head mounted by the print head is used to scan the paper. There is known a serial printer that prints on a sheet.

For example, in an ink jet printer, nozzles (dot printing elements) for ejecting ink by an electric signal to print one dot are arranged in one line along the paper carrying direction. A print head is mounted on a carrier, and this carrier is scanned by a carrier motor in a direction orthogonal to the paper conveyance direction. An electric signal is input to the print head mounted on the carrier based on the print data, and each nozzle is controlled by the electric signal to perform printing on the paper.

FIG. 8 shows a side view of the essential structure of the above-mentioned ink jet printer.

1 is along the conveyance direction P of the cut sheet 2
A print head including a plurality of nozzles arranged in a row and mounted on a carrier (not shown). This print head 1
A platen 3 made of a molding material is arranged so as to face the platen 3, and a plurality of ribs 3a for preventing wrinkles from being generated on the cut sheet 2 during printing are integrally formed on the platen 3.

Reference numeral 4 designates the cut sheet 2 and the print head 1
Is a paper feed roller for supplying the paper to the paper, and the paper 2 is fixed near the peripheral surface of the paper feed roller 4 by sandwiching the paper 2 with the paper feed roller 4 during printing. Leaf plates 5 for doing so are arranged opposite to each other. 6
Reference numerals 7 and 7 convey the cut sheet 2 printed by the print head 1, and after the printing is completed, the cut sheet 2
Is a star wheel for discharging.

The cut sheet 2 is conveyed to the print position of the print head 1 by the rotation of the paper feed roller 4. When the cut sheet 2 reaches the printing position, the rotation of the paper feed roller 4 is stopped, and the cut sheet 2 is sandwiched and fixed by the leaf plate 5 with the paper feed roller 4. Therefore, a carrier motor (not shown) scans the carrier in a direction orthogonal to the conveyance direction P of the cut sheet 2, and thus the print head mounted on the carrier is orthogonal to the conveyance direction P of the cut sheet 2. The paper is scanned in the direction
The print band) is printed.

When the printing of one line is completed, the paper feed roller 4 and the star wheels 6 and 7 are rotated, and the cut sheet 2 is cut.
When the print head 1 is conveyed by the print width of one line, the paper feed roller 4 and the star wheels 6 and 7 stop rotating again, and the leaf plate 5 sandwiches the cut sheet 2 with the paper feed roller 4. Fixed. Then, the carrier motor is driven and the scanned print head 1 prints the next line.

Similarly, the paper feed roller 4 and the star wheels 6 and 7 convey the cut sheet 2 and the print head 1.
The single-cut sheet 2 is printed by repeating the one-line printing by, and the finished single-cut sheet 2 is printed by the star wheels 6 and 7.
Is discharged by the rotation of.

[0010]

As described above, in the conventional serial printer, for example, the ink jet printer, the print head 1 conveys each line by the print width,
One line is printed and one cut sheet 2 is printed.

By the way, as shown in FIG.
If the trailing edge of the cut sheet 2 passes through between the paper feed roller 4 and the leaf plate 5 when the print head 1 is conveyed by the print width of one line, the cut sheet 2 is cut at the time of printing. Was not fixed, and there was a problem that the printing accuracy deteriorated.

In this way, when the trailing edge of the cut-sheet paper 2 passes through and comes off, a margin is left without printing after the conventional printing. However, the printing range is narrow. Therefore, there is a problem that the cut sheet cannot be used effectively.

Therefore, the present invention provides a serial printer which can convey a single-cut sheet shorter than the width of one print band by a print head to print the final print band and can effectively use the single-cut sheet. With the goal.

[0014]

SUMMARY OF THE INVENTION According to the present invention, a print head including a plurality of dot printing elements arranged in a row along a front end direction and a rear end direction of a cut form sheet to be conveyed is provided. In a serial printer that scans in the direction orthogonal to the transport direction and prints on the cut sheet by the print head, it is placed on the feed supply side of the cut sheet in the scan path of the print head, and fixes the cut sheet during printing. When a fixing member that detects the rear edge of the cut sheet and a sheet detection sensor that is located on the feeding and feeding side of the cut sheet of this fixing member and that detects the rear edge of the cut sheet The distance from the rear edge of the cut sheet to the fixed member is calculated as the remaining transportable distance, and it is determined whether the calculated remaining transportable distance is shorter than the width of one print band printed by the print head. A remaining transportable distance determining means, When the remaining transportable distance determining means determines that the remaining transportable distance is shorter than the width of one print band, the final print strip transporting means for transporting the cut sheet within the range of the remaining transportable distance, and the final print strip transporting means. In accordance with the transport distance by the transport means, the print drawing data of the final print band to be printed by the print head is shifted in the direction corresponding to the rear end side of the print head, and this shift processing shifts to the portion corresponding to the front end side of the print head. Based on the final print band drawing means for drawing non-printed data on the generated undrawn part and the drawing data drawn by the final print band drawing means, the final printing is performed on the cut sheet paper conveyed by the final print band conveying means. A final printing band printing means for printing the band is provided.

[0015]

In the present invention having such a structure, when the sheet detection sensor detects the rear edge of the cut sheet by the remaining transportable distance determination means, the distance from the rear edge of the cut sheet to the fixing member. Is calculated as the remaining transportable distance, and it is determined whether the calculated remaining transportable distance is shorter than the width of one print band printed by the print head.

When the remaining transportable distance determining means determines that the remaining transportable distance is shorter than the width of one print band, the final print band transporting means transports the cut sheet within the remaining transportable distance. It

The final drawing band drawing means shifts the printing drawing data of the final printing band to be printed by the print head in the direction corresponding to the rear end side of the printing head in accordance with the carrying distance of the final printing band carrying means. At the same time, the non-printing data is drawn in the undrawn portion generated in the portion corresponding to the front end side of the print head by this shift processing.

The final print band printing means prints the final print band on the cut sheet transported by the final print band transport means based on the drawing data drawn by the final print band drawing means.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of the main structure of an ink jet printer to which the present invention is applied.

No. 11 is a nozzle No. arranged in one line along the conveyance direction P of the cut sheet 12. 1 to Nozzle No. The head is composed of n nozzles of n and is mounted on a carrier (not shown). A platen 13 formed of a molding material is arranged so as to face the head 11, and a plurality of ribs 13a for preventing wrinkles from being formed on the cut sheet 12 during printing are integrally formed on the platen 13. There is. The nozzles form a dot print element, and the head 11 forms a print head.

Reference numeral 14 denotes the cut sheet 12 for the head 1.
1 is a paper feed roller for feeding the paper 1, and the cut sheet 2 is pressed near the peripheral surface of the paper feed roller 14 by sandwiching the cut sheet 2 with the paper feed roller 14 at the time of printing.
Leaf plates 15 are arranged to face each other in order to fix the two. Reference numerals 16 and 17 denote star wheels for conveying the cut sheet 12 printed by the head 11 and discharging the cut sheet 12 after the printing is completed.

The paper feed roller 14 and the leaf plate 15 constitute a fixing member.

FIG. 2 shows the head 11 and the paper feed roller 14, a paper sensor 18 as a paper detection sensor composed of a transmission type optical sensor for detecting the front end and the rear end of the cut sheet, and a printing position. It is a figure which shows each positional relationship with the said single-cut sheet 12 positioned to. The cut sheet 12 is shown by a broken line in FIG.

Nozzle No. of the head 11 from the paper sensor 18. The distance to the position of the nozzle of n is m, and the last nozzle N of the head 11 from the paper feed roller 14
o. The distance to the position of the nozzle (rear end) of n is h.
Further, when the head 11 is scanned one time, the image is printed 1
The print width of a line (1 print band), that is, the nozzle No. The nozzle No. 1 from the position of the nozzle (front end). The distance to the position of the nozzle of No. n is L, and the nozzle No. The distance from the position of the first nozzle to the front end of the cut sheet 12 positioned at the printing position, that is, the margin width of the front end of the cut sheet 12 is i.

It should be noted that all of the above distances are expressed as numerical values converted by the number of steps of the paper feed motor described later.

FIG. 3 is a block diagram showing the circuit configuration of the main parts of this ink jet printer. Reference numeral 21 is a CPU (central processing unit) that constitutes the main body of the control unit. ROM (read only memory) 22 in which program data of processing performed by the CPU 21 is stored, the CP
A RAM (random access memory) 23 in which areas of various memories used by the U21 to perform processing are received, data received from a host computer connected through a line, and the like, and the received data is stored. An I / O (input / output) port 25 for inputting a detection signal output from the buffer 24 and the paper sensor 18 is connected to the CPU 21 via a system bus 26, respectively.

The RAM 23 is further provided with a counter x23a for counting the number of drive steps of the paper feed motor for carrying the paper, which will be described later.

A head controller 27 for controlling the head 11, a print buffer 28 for drawing dot data (image data) to be printed by the head 11, and a carrier (not shown) on which the head 11 is mounted are provided. Carrier motor 29 for scanning in the direction orthogonal to the transport direction of the cut sheet 12 and paper for rotating the paper feed roller 14 and the star wheels 16 and 17 for transporting the cut sheet 12 The motor controller 31 that controls the feed motor 30 and
The CPU 21 via the system bus 26, respectively.
Connected with.

The print buffer 28 is connected to the head controller 27, and the CPU
The drawn dot data is directly output to the head controller 27 by the control command 21.

FIG. 4 shows the flow of the printing process performed by the CPU 21.

First, the cut sheet 12 is sucked and the paper feed roller 14 and the like are rotationally driven to convey the cut sheet 12 to the print position of the head 11 via the paper feed roller 14.

When the paper sensor 18 is turned on and the paper sensor 18 is turned on, it is determined that the front edge of the cut sheet 12 is detected, and the counter x23a formed in the RAM 23 is started. The number of driving steps of the paper feed motor 30 from this time is counted.

Next, the count value of the counter x23a is
Nozzle No. of the head 11 from the paper sensor 18. The distance m to the position of the nozzle of No. n and the nozzle No. of the head 11. Nozzle No. 1 to Nozzle No. A standby state is reached until a value (m + L + i), which is the sum of the distance L to the nozzle position of n and the margin width i of the front end portion of the cut-sheet paper 12, is added.

When the count value becomes equal to or more than the added total value (the counted value becomes equal to the added total value), the rotation of the paper feed motor 30 is stopped and the carrier motor is operated as the process of step 1 (ST1). 29 is rotationally driven to scan the head 11 mounted on the carrier for one scan in a direction orthogonal to the transport direction of the cut sheet 12 and to print one line (one print band) of dot data from the print buffer 28. Head 11 via controller 27
To print one line.

When the printing of one line is completed, the paper feed motor 30 is rotationally driven to convey the cut sheet 12 by the print width L.

After the cut sheet 12 is conveyed by the distance L,
When the rotation of the paper feed motor 30 is stopped, the paper sensor 1
It is confirmed whether 8 is in the OFF state, that is, whether the trailing edge of the cut sheet 12 is detected. Here, the storage area t is formed in the RAM 23 only when the paper sensor 18 is in the OFF state and a sufficiently large numerical value (always larger than the count value x of the counter x23a) is set by initialization.
In this case, the count value x of the counter x23a at this time is stored.

Next, whether or not the value of mh- (x-t), that is, the distance from the trailing edge of the cut sheet to the paper feed roller 14 (remaining transportable distance) is smaller than the print width L or not. Is determined (remaining transportable distance determination means).

If the value of m-h- (x-t) is equal to or greater than the print width L, the process returns to step 1 described above, and m-h- (x-t). If the numerical value of () is smaller than the print width L, the next one line is printed (printing of the line immediately preceding the last line) as described above.

Next, the storage area K formed in the RAM 23
The numerical value of mh- (x-t) at this time is stored in, and the numerical value (distance) K (= m-h-
(X−t)), the paper feed motor 30 is driven to rotate,
The cut sheet 12 is conveyed (final print band conveying means).

When the transport of the cut sheet 12 is completed and the rotation of the sheet feed motor 30 is stopped, the print buffer 28 is
From the print width L, the remaining dot data drawn in the area K is stored in the storage area K as a numerical value K = m−h− (x−
The nozzle No. of the head 11 is reduced by the numerical value (L−K) obtained by subtracting t). The nozzle No. of the head 11 that has become a non-drawing area due to the shift. Drawing is performed so that the portion including the area corresponding to 1 is filled with space (non-printing) data that is not printed (final print band drawing means).

Next, based on the dot data drawn in the print buffer 28, the carrier motor 29 is rotationally driven to move the head 11 mounted on the carrier in a direction orthogonal to the direction in which the cut sheet 12 is conveyed. 1 dot is scanned and the remaining one line of dot data is output from the print buffer 28 to the head 11 via the head controller 27 to print the last line (final print band printing means).

When the printing of the last line is completed, the paper feed motor 30 is rotationally driven to eject the cut form paper 12 and the printing process is completed.

In the present embodiment having such a structure, first, the cut sheet 12 is sucked in, and when the front end of the cut sheet 12 is detected by the sheet sensor 18, the counter x23a.
Counting starts, and the paper sensor 18 of the cut paper 12 is started.
The transport amount from the detection position of is measured as the number of drive steps of the paper feed motor 30. The cut-sheet paper 12 reaches the paper feed roller 14 and is conveyed to the print position of the head 11 by the rotation of the paper feed roller 14.

The count value x of the counter x23a is the distance m.
When + L + i, the print start position considering the front end (upper end) margin on the cut sheet 12 is positioned at the print position of the head 11, and the dot data of the first line drawn in the print buffer 28 causes The first one line is printed.

When the printing of the first line is completed, the single-cut sheet 12 is conveyed by the printing width (width of the print band) L for printing the single line by the head 11, and the printing of the next line is performed.

As described above, the conveyance of the one-line printing width L of the single-cut sheet 12 and the one-line printing are repeatedly performed, and the single-cut sheet 12 is printed.

When the trailing edge of the cut sheet 12 is detected by the sheet sensor 18, the counter x23a at that time is detected.
The counter value x of is stored in the storage area t, and the distance m−h− (x
Until -t) becomes smaller than the print width L, the above-described conveyance of the print width L and one-line printing are continuously repeated.

If the distance m-h- (x-t) from the paper feed roller 14 to the trailing edge of the cut sheet 12 becomes smaller than the print width L, one line is printed and then the paper feed roller at that time is printed. The distance from 14 to the rear edge of the cut sheet 12 (remaining transportable distance) K = m−h− (x−t), the cut sheet 12
To transport. At this time, the trailing edge of the cut sheet 12 is still located between the paper feed roller 14 and the leaf plate 15, so that the cut sheet 12 is printed by the leaf plate 15 during printing.
Can be fixed by sandwiching it with the paper feed roller 14.

At this time, when the print data is set to the entire print range of the cut sheet 12, the dot data of the remaining last line is not the dot data of the print width L as shown in FIG. Instead, the dot data has the conveyance width K as the print width. On the other hand, by the conveyance of the distance K, the print width L of the head 11 overlaps with the print width L−K of the previous one-line printed portion.

In order to print the dot data of the remaining last line, as shown in FIG. k (k is 2 or more) to the nozzle No. of the head 11. Printing can be performed by using only the nozzles up to n (rear end). On the other hand, the other nozzle Nos. No. 1 (front end) to the nozzle No. Since the nozzle of (k-1) is scanned over the already printed portion, it must be prevented from being used for printing.

Therefore, as shown in FIG. 7A, the dot data of the last line of the dot data drawn in the print buffer 28 by the print data is the nozzle number of the head 11 as shown in FIG. 7B. ． towards n (at the bottom)
The non-drawing portion D that has been shifted and generated above the shift processing is filled with unprinted data. That is, the nozzle No. The dot data of No. 1 is the nozzle number. Nozzle No. 2 dot data for nozzle N
o. (K + 1) dot data, ..., Nozzle No. (N
Nozzle No. n dot data, and the nozzle No. 1 to Nozzle No. Space (non-printing) data is drawn in (k-1).

As a result, in the last line printing, the nozzle No. No. 1 to No. Nozzles up to (k-1) are not used, and the nozzle No. k to the nozzle No. The dot data of the last line is printed using the nozzles up to n.

As described above, according to the present embodiment, the distance m-h from the paper feed roller 14 to the rear end of the single-cut sheet 12 measured after the rear edge of the single-cut sheet 12 is detected by the paper sensor 18. When-(x-t) is smaller than the print width L of one line printed by the head 11, the distance K = m-h- from the paper feed roller 14 to the trailing edge of the cut sheet 12 at that time.
(X-t), and the remaining dot data in the print buffer 28 is transferred to the nozzle No. at the rear end of the head 11 by a width corresponding to the carry distance. n is shifted to the side corresponding to n for drawing, and the nozzle No. at the front end of the head 11 is changed by this shift processing. 1 is filled with non-printed data and the last line is printed with the dot data drawn in the print buffer 28, so that the single-cut sheet 12 is printed by the head 11. The sheet can be conveyed shorter than the width, and the last line can be fixed by sandwiching the cut sheet 12 with the sheet feed roller 14 by the leaf plate 15 for printing. Therefore, it is possible to perform highly accurate printing even in the final line printing, and further, it is possible to reduce the margin at the rear end of the cut sheet 12 to the distance from the paper feed roller 14 to the head 11. Can be used effectively.

[0055]

As described above in detail, according to the present invention,
It is possible to provide a serial printer that can effectively use a single-cut sheet by conveying the single-cut sheet with a width shorter than the width of one print band by the print head and printing the final print band.

[Brief description of drawings]

FIG. 1 is a side view showing the configuration of a main part of an embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship among a head, a paper feed roller, a paper sensor, and a cut sheet of the embodiment.

FIG. 3 is a block diagram showing a circuit configuration of a main part of the embodiment.

FIG. 4 is a diagram showing a flow of a printing process of the embodiment.

FIG. 5 is a view for explaining the position and width of each one-line print and the position and width of the last line showing the embodiment.

FIG. 6 is a diagram for explaining a usage state of the nozzles of the head according to the embodiment in printing the last line.

FIG. 7 is a diagram showing a drawing state of a print buffer according to the embodiment.

FIG. 8 is a side view for explaining a printing state of the inkjet printer.

FIG. 9 is a side view showing a state at the time of printing the last line of the conventional inkjet printer.

[Explanation of symbols]

11 ... Head, 12 ... Single sheet paper, 14 ... Paper feed roller,
15 ... Leaf plate, 18 ... Paper sensor, 21 ... CP
U, 23a ... Counter x, 29 ... Carrier motor, 30
… Paper feed motor.

Claims (1)

[Claims] 1. A print head comprising a plurality of dot printing elements arranged in a row along a front end direction and a rear end direction of a cut sheet to be conveyed is orthogonal to a conveyance direction of the cut sheet. In a serial printer that scans in the direction and prints on the cut sheet by the print head, the serial printer is arranged on the conveyance supply side of the cut sheet in the scanning path of the print head, and fixed to fix the cut sheet at the time of printing. A member, a sheet detection sensor that is arranged on the conveyance supply side of the cut sheet of the fixing member, and detects a rear end of the cut sheet, and a state in which the sheet detection sensor detects the rear end of the cut sheet. At this time, the distance from the trailing edge of the cut sheet to the fixing member is calculated as the remaining transportable distance, and whether the calculated remaining transportable distance is shorter than the width of one print band printed by the print head. Remaining to judge whether When the transportable distance determining means and the remaining transportable distance determining means determine that the remaining transportable distance is shorter than the width of the one print band, the cut sheet is transported within the remaining transportable distance. In accordance with the final print band conveying means and the conveying distance by the final print band conveying means, the print drawing data of the final print band to be printed by the print head is shifted in the direction corresponding to the rear end side of the print head, and Based on the final print band drawing means for drawing non-print data in the undrawn part generated in the part corresponding to the front end side of the print head by the shift process, and the drawing data drawn by the final print band drawing means, A serial printer, comprising: final print band printing means for printing the final print band on the single-cut sheet conveyed by the final print band carrying means.