JPH10226125A - Printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing device capable of maximally utilizing a printable area of a printing paper while reliably preventing a print dot row from protruding from a printing rear end of a printable area. I do. SOLUTION: In the case of one-pass printing, when it is determined that the print data of the print dot row D2 exceeds the print rear end position L in the printable area of the paper P, the print data of the print dot row D2 is printed. The data is developed while shifting the data development position so as not to exceed the rear end position L, and the feed amount of the paper P is changed in accordance with the deviation of the data development position. Also when performing the printing, if it is determined that the print data of the print dot arrays D5 and D6 is beyond the print rear end position L in the printable area of the paper P, the print data of the print dot arrays D5 and D6 The data is developed while shifting the data development position so as not to exceed the end position L, and the feed amount of the paper P is changed according to the shift of the data development position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prints a print dot row composed of a plurality of print dots by moving a print head in a direction perpendicular to the paper feed direction while feeding print paper having a predetermined printable area by a paper feed mechanism. Regarding a printing device that forms a desired print by forming a head, in particular, to maximize the printable area of printing paper while reliably preventing a print dot row from protruding from the printing end of the printable area. The present invention relates to a printing device capable of performing the following.

[0002]

2. Description of the Related Art Conventionally, while a printing paper is fed through a paper feeding mechanism, a printing head having a printing unit is moved at a predetermined pitch in the paper feeding direction in a direction orthogonal to the paper feeding direction, and printing of a plurality of printing dots is performed. 2. Description of the Related Art Various printing apparatuses such as an ink jet printer that prints characters and the like by forming dot rows on printing paper are known.

In this type of printing apparatus, the maximum area (printable area) that can be printed on printing paper is determined for reasons such as printing control and the mechanism of a printing mechanism or a paper feeding mechanism. When printing characters and the like, it is desirable that printing can be performed by making maximum use of the printable area.

Under such circumstances, a conventional printing apparatus performs printing by a method as shown in FIG. Here, a printing method performed by a conventional inkjet printer will be described with reference to FIG. FIG. 6 is an explanatory view schematically showing a printing method performed by a conventional inkjet printer.

Here, as is well known, the ink jet printer includes an ink jet head in which a plurality of nozzle openings for discharging ink are arranged in a vertical direction, and such an ink jet head is orthogonal to the feeding direction of the printing paper. In this case, ink is ejected from each nozzle opening while being moved in the direction of printing to print characters and the like on printing paper.

FIG. 6 shows one-pass printing (left side in FIG. 6) in which printing of a printable width by each nozzle opening is completed in one pass of the ink-jet head, and two passes of the ink-jet head. In the case of two-pass printing that completes printing with a printable width by nozzle openings (right side in FIG. 6)
It is shown. Here, the inkjet head used for one-pass printing has ten nozzle openings,
An example in which one line is printed in the vertical direction is shown. In addition, the ink jet head used for two-pass printing is 9
Similarly, an example is shown in which one nozzle opening is provided and one line is printed in the vertical direction. In FIG. 6, A indicates the feeding direction of the printing paper, and B indicates the moving direction of the inkjet head. L indicated by a broken line is the position of the trailing edge of the printable area of the printing paper, and E is the trailing edge of the printing paper.

In FIG. 6, when performing one-pass printing,
The ink is ejected from the nozzle opening of 0 nozzles to print dot row D
After printing 1, the printing paper is fed in the direction A by an amount corresponding to the printable width, and further, a printing dot row D2 is printed following the printing dot row D1. At this time, in the conventional ink jet printer, no special control such as selecting the number of nozzle openings for ejecting ink in consideration of the printing end position L is performed at all. As a result, a dot row (four print dots in FIG. 6) is formed beyond the print rear end position L.

In the case of performing two-pass printing, after printing ink dot rows D3 by ejecting ink from nine nozzle openings, the printing paper is moved in the A direction by an amount corresponding to half the printable width. Then, the next print dot row D4 is printed so as to be arranged between each print dot in 1/2 of the print dot row D3. Specifically, the first print dot of the print dot row D4 is arranged between the fifth print dot and the sixth print dot in the print dot row D3. Similarly, after the printing paper is sent in the direction A by an amount corresponding to a half of the printable width, the printing dot row D
The next print dot row D5 is printed so as to be arranged between each print dot at 1/2 of 4. At this time, in the print dot row D5, five print dots are printed to complete two-pass printing, and a gap is generated between the lower end of the print dot row D5 and the print rear end position L.

[0009]

By the way, in the above-mentioned conventional ink jet printer, the printing rear end position L of the printable area of the printing paper is usually set such that the rear end E of the printing paper comes from the paper feed roller provided in the paper feeding mechanism. In many cases, the print quality is set to a position where print quality can be assured just before the departure position. From this point, the portion of the print paper that has exceeded the print trailing end position L has already come off the paper feed roller. Therefore, it cannot be said that it is held in a state appropriate for printing.

Therefore, considering the case of the one-pass printing, the state in which the lower printing dot in the printing dot row D2 exceeds the printing rear end position L, that is, the rear end E of the printing paper
Is printed out of the paper feed roller, the print quality cannot be assured for the print dot row D2 printed beyond the rear end position L of the print. There is a problem that the print quality of the print dots printed near the rear end position L is extremely reduced. On the other hand, when the printing of the printing dot row D2 is not performed so that the printing dot row does not protrude from the printing rear end position, the printing dot row D1 is positioned between the printing dot at the lower end of the printing dot row D1 and the printing rear end position L. In this case, a large gap is formed, and as a result, the area of the unprinted portion in the printable area becomes large, making it impossible to make the best use of the printable area.

In the case of the two-pass printing, a request for completing the two-pass printing in the final printing dot row D5 requires that when the printing dot row D5 is printed, the rear end E of the printing paper is already fed. Because it has come off the roller,
The print quality is not guaranteed for the print dot row D5.
For this reason, if printing is performed with the validity up to the fifth print dot of the print dot row D4, a large gap exists between the fifth print dot of the print dot row D4 and the rear end position L of the print. As a result, there remains a problem that the printable area cannot be used to the maximum.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and it is intended to prevent a print dot row from protruding from a printing rear end of a printable area and to reduce a printable area of a printing paper. It is an object of the present invention to provide a printing device that can be used to the maximum.

[0013]

According to a first aspect of the present invention, there is provided a printing apparatus, comprising: a paper feeding mechanism for feeding printing paper having a predetermined printable area in a predetermined paper feeding direction; Print head having a plurality of printed portions formed and forming a print dot row composed of a plurality of print dots on a sheet sent by a sheet feed mechanism while moving in a predetermined print direction orthogonal to the sheet feed direction and performing desired printing A data developing unit that expands print data to be printed via the print head for each of the print dot strings and supplies the print data to the print head; and Determining means for determining whether the print data of the print dot row exceeds a predetermined reference position in a printable area of the paper, When it is determined by the determination means that the print data of the print dot row exceeds a predetermined reference position of the printable area, the data developing means is controlled so that the print data of the print dot row does not exceed the predetermined reference position. First control means for causing the print data to be developed while shifting the data development position, controlling the paper feed mechanism in accordance with the shift of the data development position, and changing the paper feed amount of the print paper, and via the paper feed mechanism And a second control means for performing printing by a print head in accordance with print data developed by the data development means while feeding printing paper.

In the printing apparatus according to the first aspect, when desired printing is performed on printing paper via a printing head having a plurality of printing sections arranged at a predetermined pitch in a paper feeding direction by a paper feeding mechanism, first, data development means The print data is developed for each print dot string via the. When the print data is expanded by the data expanding means, when the determination means determines that the print data of the print dot row exceeds a predetermined reference position in the printable area of the printing paper, the first control means sets the data. The developing means is controlled so that the print data of the print dot row is developed while shifting the data developing position so as not to exceed a predetermined reference position, and the feed amount of the printing paper by the paper feeding mechanism is adjusted according to the shift of the data developing position. Be changed. Based on such control, the print data is not developed beyond the predetermined reference position of the printable area, and thereby the print data can be printed by making the best use of the printable area.

After the above, under the control of the second control means,
While the printing paper is fed through the paper feeding mechanism, printing is performed by the print head in accordance with the print data developed by the data development unit and the first control unit and the paper feed amount changed by the first control unit.

In the printing apparatus according to the first aspect, if the determination means determines that the print data of the print dot row exceeds a predetermined reference position in the printable area of the printing paper, the first control means. Since the print data of the print dot row is developed while shifting the data development position so as not to exceed the predetermined reference position, and the feed amount of the printing paper by the paper feed mechanism is changed according to the shift of the data development position, so printing is performed. The data is not expanded beyond the predetermined reference position of the printable area, and thus the print data can be printed by making maximum use of the printable area.

According to a second aspect of the present invention, in the printing apparatus of the first aspect, the predetermined reference position is set at a printing rear end position of a printable area. As described above, in the printing apparatus according to the second aspect, since the predetermined reference position is set at the rear end position of the printable area, the print data is not developed beyond the rear end position of the printable area. In addition, it is possible to print the print data by maximizing the use of the printable area up to a position near the lower end of the print.

Further, in the printing apparatus according to a third aspect, in the printing apparatus according to the second aspect, the paper feeding mechanism has a paper feed roller, and the printing rear end position of the printable area is:
It is characterized in that it corresponds to the position where the printing paper comes off the paper feed roller. In the printing apparatus according to the third aspect, since the printing rear end position of the printable area corresponds to the position where the printing paper comes off from the paper feed roller of the paper feeding mechanism, the printing paper remains until the printing head reaches the printing rear end position. Can be maintained in an appropriate state, thereby making it possible to maintain the print quality satisfactorily while printing the print data by making maximum use of the printable area.

According to a fourth aspect of the present invention, in the printing apparatus according to any one of the first to third aspects, the second control means prints a dot row of a predetermined width based on a printing operation of a plurality of passes. The print head is driven and controlled so as to perform the following. In the printing apparatus according to the fourth aspect, since the drive control of the print head is performed via the second control means so as to perform printing of a dot row of a predetermined width based on the printing operation of a plurality of passes, so-called interlaced printing is performed. In this case, the print data can be printed by making the most of the printable area.

Further, in the printing apparatus according to the fifth aspect, in the printing apparatus according to the fourth aspect, when the determination means determines that the print data of the print dot row exceeds a predetermined reference position of the printable area, (1) The control means controls the data developing means for each of the plurality of passes to develop the print data while shifting the data developing position so that the print data of the print dot row does not exceed a predetermined reference position. It is characterized in that the paper feed mechanism is controlled to change the paper feed amount of the printing paper in accordance with the shift of the developing position. In the printing apparatus according to the fifth aspect, each time the printing operation of each pass of the interlaced printing is performed, the data developing means is controlled via the first control means so that the printing data of the printing dot row does not exceed the predetermined reference position. Print data is developed while shifting the development position, and the paper feed mechanism is controlled according to the deviation of the data development position, so the paper feed amount of the print paper is changed, so print data can be printed even in interlaced printing The print data is not expanded beyond the predetermined reference position of the area, so that the print data can be printed by making maximum use of the printable area.

According to a sixth aspect of the present invention, in the printing apparatus according to any one of the first to fifth aspects, the print head is an ink jet head having a plurality of nozzles. In the printing apparatus according to the sixth aspect, even in an ink jet printer equipped with an ink jet head, similarly to the above, print data is not developed beyond a predetermined reference position of the printable area, thereby maximizing the printable area. And print data can be printed.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a printing apparatus according to the present invention will be described in detail with reference to the drawings based on an embodiment in which the present invention is embodied for an ink jet printer.
First, a schematic configuration of the ink jet printer according to the present embodiment will be described with reference to FIGS. FIG. 1 is a side sectional view of an ink jet printer, FIG. 2 is an enlarged side cross sectional view showing a configuration around an ink jet head, and FIG. 3 is a block diagram showing a control system of the ink jet printer.

As shown in FIG. 1, the ink jet printer 1 basically includes a paper feed mechanism 10 for feeding a plurality of papers P stacked on a paper table 12 one by one, and a paper feed mechanism 1
0, a paper feed mechanism 20 for transporting the paper P fed through the paper transport path 4 to a paper discharge table (not shown), and a printing mechanism 30 for discharging ink on the paper P being transported for printing.
And a drive mechanism (not shown) that rotationally drives the pickup roller 14 of the paper feed mechanism 10, the paper feed roller 21 of the paper feed mechanism 20, and the feed roller 25.

First, the paper feed mechanism 10 will be briefly described. As shown in FIG. 1, the paper feed cassette 11 is detachably mounted in a cassette mounting recess 2a formed at the upper end of the rear end of the main body frame 2. The rear end of the paper table 12 on which a plurality of sheets P are stacked is pivotally supported by the paper feed cassette 11 and the front end thereof is urged upward by a compression coil spring 13. .

Immediately above the front end of the paper table 12,
A pickup roller 14 extending in the left-right direction is provided,
Left and right ends of the pickup roller 14 are rotatably supported by a pair of left and right side wall plates 3 connected to the main body frame 2 respectively.

That is, a plurality of sheets P stacked on the sheet table 12 of the sheet cassette 11 are pressed by the pickup roller 14 by the compression coil spring 13 via the sheet table 12. When the pickup roller 14 is rotated in a counterclockwise direction by a drive mechanism (not shown) driven by a feed motor 62 (see FIG. 3) formed of a stepping motor, only the upper sheet P is rotated by the pickup roller 14. Is fed toward the print head 36.

Next, the paper feed mechanism 20 for transporting the paper P fed by the paper feed mechanism 10 will be described. As shown in FIGS. 1 and 2, a paper guide portion 2b of the main body frame 2 extending forward from the cassette mounting recess 2a.
As a result, a paper transport path 4 for transporting the paper P is formed, and a rubber paper feed roller 21 is rotatably provided on the main body frame 2 on the upstream side of an ink jet head 36 described later in the paper transport path 4. The paper feed roller 21 is pivotally supported.
Driven roller 22 that contacts the upper side of the side wall plate 3
, And rotatably connected to the lower end of a swing arm 24 urged by a compression coil spring 23.

On the other hand, on the downstream side of the ink jet head 36 in the paper transport path 4, a rubber feed roller 25 is provided.
Are rotatably supported by the body frame 2 and a plurality of driven spurs 26 abut against the feed roller 25 from above.
Are gear-shaped rollers having a plurality of radial projections, and support plates 33 for supporting the carriage 31 described later.
Are rotatably supported at predetermined intervals in the print width direction. The feed roller 21 and the feed roller 25 are driven by a feed motor 62. It is driven to rotate clockwise while being synchronized with the pickup roller 14 via a drive mechanism (not shown),
The paper P is transported in the transport direction.

Next, the printing mechanism 30 will be described.
As shown in FIGS. 1 and 2, a carriage 31 is supported by a side wall (not shown) and extends in a left-right direction.
And an upper end portion of a support plate 33 movably supported in the left-right direction. An ink cartridge 35 containing ink to be used for printing is detachably mounted on a cartridge holder 34 fixed to the carriage 31. An ink jet head 36 having a plurality of ink jet nozzles (not shown) for ejecting ink supplied from the ink cartridge 35 is mounted so as to face the paper transport path 4.

The carriage 31 is driven by a carriage driving motor 63 via a carriage driving mechanism (not shown).
(See FIG. 3), the paper P reciprocates in a direction orthogonal to the feeding direction. Here, in the inkjet head 36, for example, 64 inkjet nozzles are divided and arranged in two rows of 32 each. Each row extends in the paper feed direction. Then, based on the dot pattern data to be printed, ejection is selectively driven from these 64 inkjet nozzles.

By the way, immediately upstream of the paper feed roller 21, a paper detection lever 4 swinging with the paper P being conveyed is provided.
0 is pivotally supported by the main body frame 2 so as to be rotatable, and a lower end portion of the paper detection lever 40 is provided with an optical sensor that detects the swinging position of the paper detection lever 40, that is, the front end or the rear end of the paper P. A paper edge detection sensor 41 is provided. That is, when the sheet P is conveyed, as shown in FIG. 1, the sheet detection lever 40 rotates clockwise, so that the sheet edge detection sensor 41 outputs the sheet detection signal PE of the “H” level. Is output and when the trailing edge of the sheet P passes, as shown in FIG.
Is returned to the original return position, the sheet edge detection sensor 4
1 outputs an "L" level paper detection signal PE.

Next, the control system of the ink jet printer 1 is configured as shown in the block diagram of FIG. The control device 50 includes a CPU 51, a ROM 52 and a RAM 53 connected to the CPU 51 via a bus 54 such as a data bus, an input / output interface 55, and drive circuits 56 to 58 connected to the input / output interface 55.
It is composed of

The input / output interface 55 includes:
An operation panel 60 provided with a power switch, various switches, and display lamps, an origin position detection switch 61 for detecting the origin position of the carriage 31, a paper end detection sensor 41, and the like are connected. The head 36 is connected, the feed circuit 62 is connected to the drive circuit 57, and the carriage drive motor 63 is connected to the drive circuit 58. Further, a communication interface 64 connected to the bus 54
Through an external electronic device 65 such as a host computer.
Can receive the recording data transmitted from.

The ROM 52 stores an ink jet head 36, a carriage drive motor 63, a feed motor 62, and the like based on a communication control program for receiving recording data from the external electronic device 65 and print data developed into dot pattern data. A print drive control program for drive control, a print control program specific to the present application, which will be described later, and the like are stored. The RAM 53 is provided with various memories and buffers necessary for communication control and print control, in addition to a memory for storing received recording data and a print data memory for storing print data.

Next, the printing control performed in the ink jet printer 1 configured as described above will be described with reference to FIG.
It will be described based on. FIG. 4 is a flowchart of the print control program.

When the printing control is started in FIG. 4, first, in step (hereinafter abbreviated as S) 1, the correspondence between each ink jet nozzle position of the ink jet head 36 and the printing data is determined, and the printing data memory of the RAM 53 is stored. Is obtained. At this time, the development position of the print data is acquired for each nozzle row constituted by each inkjet nozzle, that is, for each print dot row that can be printed via each inkjet nozzle.

Next, in S2, it is determined whether or not the print data of the print dot row exceeds the print trailing end position in the printable area of the paper P with respect to the acquisition of the print data development position. Here, the printing rear end position is the most upstream in the paper feeding direction of each ink jet nozzle of the ink jet head 36 when the rear edge of the paper P is released from the nip between the feed roller 21 and the driven roller 22. It is set at a position facing the ink jet nozzle existing on the side. Specifically, in FIG. 2, the nip position of the sheet P by the sheet feeding roller 21 and the driven roller 22 and
A distance X between each of the ink jet nozzles of the ink jet head 36 and the position of the ink jet nozzle located at the most upstream side along the paper feed direction, in other words, a distance X from the trailing edge of the paper P toward the printable area. Is set to the position that was set. Whether or not the ink jet head 36 has approached the rear end position of the printing is determined, for example, from the time when the leading edge of the paper P passes the paper edge detection sensor 41 and the “H” level paper detection signal PE is detected. It is obtained by adding the feed amount of the paper P by the feed motor 62. However, since it is necessary to know the length of the paper P in the transport direction, it is necessary to use only the paper of a predetermined length, select and input the type of paper in advance, or freely input the length of the paper. Make sure you can do it.

In S2, when it is determined that the print data of the print dot row exceeds the print rear end position in the printable area of the paper P (S2: YES), the lower end position of the undeveloped area in the print data memory is set. Checked, based on the lower end position of the undeveloped area, acquire the developed position while shifting the data developed position so that the print data does not exceed the trailing end position of the printing, and perform data development, and Correspondingly, feed data for changing the feed amount of the paper P is created (S3). Thereafter, the process proceeds to S5.

On the other hand, if it is determined in S2 that the print data of the print dot row does not exceed the print trailing end position in the printable area of the paper P (S2: NO),
At S4, the print data is developed according to the print data development position acquired at S1. After this, S5
Move to

In step S5, the ink is fed while the sheet P is fed based on the print data expanded in step S3 and the changed feed amount data of the sheet P, or based on the print data expanded in step S4. Head 36
Printing is performed via.

Next, a printing method based on the print control will be described with reference to FIG. 5 while showing a specific print example in order to facilitate understanding of the print control. FIG. 5 is an explanatory diagram schematically showing a printing method in the ink jet printer of the present embodiment.

FIG. 5 shows one of the ink jet heads 36.
In the case of one-pass printing (the left side in FIG. 5) in which the printing of the printable width by each of the inkjet nozzles is completed in a pass, and the printing of the printable width in each of the inkjet nozzles in the two passes of the inkjet head 36 is completed. The case of two-pass printing (right side in FIG. 5) is shown.

Here, in order to simplify the printing method and facilitate understanding, as in FIG. 6, a head having 10 ink jet nozzles is shown as the ink jet head 36 used for one-pass printing. An example in which one line is printed is shown. Further, as an inkjet head used for two-pass printing, a head having nine inkjet nozzles is shown, and similarly, an example in which one line is printed in the vertical direction is shown. Also,
In FIG. 5, A indicates the feeding direction of the paper P, and B indicates the moving direction of the inkjet head 36. Further, L indicated by a broken line is a printing rear end position of the printable area of the paper P, and E is
At the back end.

First, the case of performing one-pass printing will be described. In FIG. 5, when one-pass printing is to be performed, the 10
Correspondence is established between each of the ink jet nozzle positions and the print data, and the development position of the print data in the print data memory of the RAM 53 is obtained (S1). Since the print data of the print dot row D1 does not exceed the rear end position L of the print (S2: NO), the print data is expanded according to the expansion position of the print data acquired as described above (S4). After the printing paper is fed in the direction A by an amount corresponding to the printable width of each ink jet nozzle based on the print data, the ink is ejected from the ten ink jet nozzles of the ink jet head 36 while driving the carriage 31. Then, the print dot row D1 is printed (S5).

Next, in the same manner as described above, the print dot row D
In order to print No. 2, the positions of each of the ten ink jet nozzles of the ink jet head 36 are associated with the print data, and the development position of the print data in the print data memory of the RAM 53 is obtained (S1). At this time, since the print data of the print dot row D2 exceeds the print rear end position L as described with reference to FIG.
2: YES), the lower end position of the undeveloped area in the print data memory is checked, and based on the lower end position of the undeveloped area, the data development position is shifted while shifting the data development position so that the print data does not exceed the rear end position of printing. The acquired data is developed and feed data for changing the feed amount of the paper P corresponding to the shift of the data development position is created (S3). Specifically, as shown in FIG. 5, four print dots out of ten print dots are shifted upstream, and the feed amount of the paper P is reduced by four print dots. Be changed. In addition, of the ten nozzles,
The four downstream nozzles (indicated by open circles in FIG. 5) are not used.

As described above, in the case of one-pass printing, when it is determined that the print data of the print dot row D2 is beyond the print rear end position L in the printable area of the paper P, the print data of the print dot row D2 is determined. Is developed while shifting the data development position so as not to exceed the printing rear end position L, and the feed amount of the paper P is changed according to the shift of the data development position, so that the print data is printed in the printable area. The print data is not developed beyond the rear end position L, so that the print data can be printed by making maximum use of the printable area up to a position near the print rear end position L.

Further, the printing rear end position L of the printable area
Corresponds to the position where the sheet P comes off from the sheet feeding roller 21 and the driven roller 22, that is, the printing rear end position L is
Is set at the position of the distance X from the rear end E, the paper P is held in an appropriate state until the ink jet head 36 reaches the print rear end position L, thereby maximizing the printable area. It is possible to maintain print quality satisfactorily while printing print data by utilizing the print data. Although the feed roller 25 is still engaged with the sheet P even if the sheet P is detached from the feed roller 21, the feed roller 25 and the driven spur 2
6 alone is not sufficient to keep the paper P in an appropriate state.

Next, the case of performing two-pass printing will be described. In FIG. 5, when two-pass printing is performed, the ink jet head 36 is moved to print the print dot row D3.
Correspondence is established between each of the ink jet nozzle positions and the print data, and the development position of the print data in the print data memory of the RAM 53 is obtained (S1). Since the print data of the print dot row D3 does not exceed the print trailing end position L (S2: NO), the print data is developed according to the print data development position acquired as described above (S4). Based on the print data, after the printing paper is sent in the direction A by an amount corresponding to の of the printable width by each ink jet nozzle, the nine ink jet nozzles of the ink jet head 36 are driven while the carriage 31 is driven. The print dot row D3 is printed by discharging ink (S5).

Next, in the same manner as described above, the print dot row D
In order to print 4, the correspondence between the nine ink jet nozzle positions of the ink jet head 36 and the print data,
The development position of the print data in the print data memory of the RAM 53 is obtained (S1). Such a print dot row D4
Since the print data does not exceed the print end position L (S2: NO), the print data is expanded in accordance with the print data expansion position acquired as described above (S4), and the print data After the printing paper is fed in the direction A by an amount corresponding to の of the printable width of each ink jet nozzle, the ink is ejected from the nine ink jet nozzles of the ink jet head 36 while driving the carriage 31. The print dot row D4 is printed (S5).

Further, the positions of the nine ink jet nozzles of the ink jet head 36 are associated with the print data in order to print the print dot row D5, and the development position of the print data in the print data memory of the RAM 53 is obtained (S1). ). At this time, the print data of the print dot row D5 is, as described with reference to FIG.
(S2: YES), the lower end position of the undeveloped area in the print data memory is checked,
Based on the lower end position of the undeveloped area, the data development position is obtained while shifting the data development position so that the print data does not exceed the print end position, and the data development is performed.
Feed data for changing the feed amount of the paper P corresponding to the shift of the data development position is created (S3). More specifically, as shown in FIG. 5, two print dots out of the nine print dots are shifted upward, and the feed amount of the paper P is 2
It is changed so as to be reduced by the number of print dots. Then, after the paper P is fed by the changed feed amount, ink is ejected from the six ink jet nozzles while driving the carriage 31 to print the print dot row D5 (S5).

Next, in order to complete the two-pass printing, the ink jet head 36 is operated to print the print dot row D6.
Correspondence is established between each of the ink jet nozzle positions and the print data, and the development position of the print data in the print data memory of the RAM 53 is obtained (S1). At this time, since the print data of the print dot row D6 exceeds the print end position L (S2: YES), the lower end position of the undeveloped area in the print data memory is checked, and the lower end of the undeveloped area is checked. Based on the position, the data development position is acquired while shifting the data development position so that the print data does not exceed the rear end position of the printing, and the data development is performed. In addition, the feed amount of the paper P corresponding to the shift of the data development position Is created (S3). In particular,
As shown in FIG. 5, six print dots out of nine print dots are shifted upstream by six print dots, and the feed amount of the paper P is changed so as to be reduced by six print dots. Then, after the paper P is fed by the changed feed amount, ink is ejected from the three inkjet nozzles while driving the carriage 31 to print the print dot row D6 (S
5).

As described above, in the case of two-pass printing, that is, when performing interlaced printing, the print dot arrays D5 and D6
Is determined to be beyond the print end position L in the printable area of the paper P, the data development position is determined so that the print data of the print dot strings D5 and D6 do not exceed the print end position L. And the feed amount of the paper P is changed in accordance with the shift of the data development position, so that the print data is not developed beyond the printing rear end position L of the printable area. As a result, the print data can be printed by maximizing the use of the printable area up to a position near the printing rear end position L.

In addition, at each printing operation of each pass of the interlaced printing, the printing data of the printing dot rows D5 and D6 is expanded while shifting the data developing position so as not to exceed the printing end position L. Since the paper feed amount of the paper P is changed in accordance with the shift of the data development position, the print data is not developed beyond the printing rear end position L of the printable area even in the case of interlaced printing. Thus, print data can be printed by making the most of the printable area.

By the way, in the above embodiment, if the size and the transport direction of the paper P used for printing are determined in advance, for example, if the “A4” paper is used in the portrait orientation, the paper P 297m in transport direction
m, the trailing edge of the sheet P is determined based on the time when the leading edge of the sheet is detected.
Is detected from the paper feed roller 21 by the paper detection lever 40.
The distance between the print end position and the nip point of the paper feed roller 21 is also taken into consideration, and the print trailing end position L is indirectly determined. However, the present invention is not limited to this. For example, the rear end of the sheet may be directly detected. That is, based on the time when the trailing edge of the sheet P is released from the paper detection lever 40, the paper feed lever 21 determines how far the trailing edge E of the sheet P is released from the paper feed roller 21 afterward. It may be determined from the distance between the roller 21 and the nip point.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various improvements and modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, in both of the one-pass printing and the two-pass printing, the control to expand the print data and the control to feed the paper P are performed at the rear end of the paper P.
In the case of one-pass printing, a configuration may be adopted in which the development of print data and the feed control of the paper P are performed at the front end of the paper P.

In the two-pass printing according to the above-described embodiment, the paper feed amount between the passes during the normal printing operation is constant. For example, in FIG. Both the amount and the paper feed amount performed after printing of the print dot row D4 are equivalent to 4.5 times the nozzle row pitch, but are not limited thereto, and the paper feed amount is alternately changed at a different paper feed amount. Two-pass printing in which P is conveyed may be used.

Further, as interlaced printing, 2
The present invention is not limited to pass printing, but may be, for example, three-pass printing, four-pass printing, or more than one multi-pass printing. In either case, the present invention can be applied.

[0058]

According to the first aspect of the present invention, when the determination means determines that the print data of the print dot row exceeds the predetermined reference position in the printable area of the print paper, the first control means is used. Since the print data of the print dot row is developed while shifting the data development position so as not to exceed the predetermined reference position, and the feed amount of the printing paper by the paper feed mechanism is changed according to the shift of the data development position, The print data is not developed beyond the predetermined reference position of the printable area, whereby the print data can be printed by making the most of the printable area.

Further, in the printing apparatus according to the second aspect, since the predetermined reference position is set at the printing end position of the printable area, the print data is expanded beyond the printing end position of the printable area. It is possible to print the print data by maximizing the use of the printable area up to a position near the lower end of the printable area.

Further, in the printing apparatus according to the third aspect, since the printing rear end position of the printable area corresponds to the position where the printing paper comes off from the paper feed roller of the paper feeding mechanism, the print head is positioned at the printing rear end position. The print paper can be held in an appropriate state up to, so that the print quality can be maintained satisfactorily while printing the print data by making maximum use of the printable area.

In the printing apparatus according to the fourth aspect, the second
Through the control means, the drive control of the print head is performed so as to print a dot row of a predetermined width based on the printing operation of a plurality of passes, so that the printable area is maximized even when performing so-called interlaced printing. It is possible to print the print data by utilizing it.

Further, in the printing apparatus according to the fifth aspect, for each printing operation of each pass of the interlaced printing, the data developing means is controlled via the first control means so that the print data of the print dot row is set at the predetermined reference position. While expanding the print data while shifting the data development position so that it does not exceed
The paper feed mechanism is controlled according to the deviation of the data development position, and the paper feed amount of the printing paper is changed, so that even during interlaced printing, the print data does not spread beyond the predetermined reference position of the printable area. This makes it possible to print the print data by making the most of the printable area.

In the printing apparatus according to the sixth aspect, even in an ink jet printer equipped with an ink jet head, print data is not developed beyond a predetermined reference position of a printable area, as described above. Printing data can be printed by making maximum use of the printable area.

As described above, the present invention provides a printing apparatus capable of maximizing the use of the printable area of the printing paper while reliably preventing the print dot row from protruding from the trailing edge of the printable area. Can be provided.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an ink jet printer according to an embodiment.

FIG. 2 is an enlarged side sectional view showing a configuration near an inkjet head.

FIG. 3 is a block diagram illustrating a control system of the inkjet printer.

FIG. 4 is a flowchart of a print control program.

FIG. 5 is an explanatory diagram schematically showing a printing method in the inkjet printer according to the embodiment.

FIG. 6 is an explanatory diagram schematically showing a printing method performed by a conventional inkjet printer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inkjet printer 10 paper feed mechanism 20 paper feed mechanism 21 paper feed roller 30 printing mechanism 36 inkjet head 41 paper edge detection sensor 50 control device 51 CPU 52 ROM 53 RAM D1 to D6 print dot row L print trailing edge position P paper

Claims (6)

[Claims] 1. A paper feed mechanism for feeding print paper having a predetermined printable area in a predetermined paper feed direction, and a plurality of printing units arranged at a predetermined pitch in the paper feed direction, wherein a plurality of printing units are arranged in a predetermined print direction orthogonal to the paper feed direction. A print head that forms a print dot row composed of a plurality of print dots on a sheet fed by a sheet feed mechanism while moving, and performs a desired print; and print data that is printed via the print head. Data developing means for developing the print dot array and supplying the print head, when developing print data by the data developing means,
Determining means for determining whether or not the print data of the print dot row exceeds a predetermined reference position in the printable area of the sheet; and wherein the print data of the print dot row determines the predetermined reference position of the printable area by the determination means. When it is determined that the print data exceeds the predetermined value, the control unit controls the data development unit to develop the print data while shifting the data development position so that the print data of the print dot row does not exceed the predetermined reference position. First control means for controlling the paper feed mechanism to change the paper feed amount of the print paper in accordance with the above, and printing by a print head in accordance with print data developed by the data developing means while feeding the print paper via the paper feed mechanism And a second control means for performing the following. 2. The printing apparatus according to claim 1, wherein the predetermined reference position is set at a printing rear end position of a printable area.
The printing device according to the above. 3. The paper feeding mechanism includes a paper feed roller, and a print trailing end position of the printable area corresponds to a position where a print paper comes off from the paper feed roller. Printing device. 4. The printing apparatus according to claim 1, wherein the second control unit controls the driving of the print head so as to print a dot row having a predetermined width based on a printing operation in a plurality of passes. The printing device according to any one of the above. 5. When the determination means determines that the print data of the print dot row exceeds a predetermined reference position of the printable area, the first control means sets the
By controlling the data development means to develop the print data while shifting the data development position so that the print data of the print dot row does not exceed a predetermined reference position, the paper feed mechanism is adapted to the shift in the data development position. 5. The printing apparatus according to claim 4, wherein the printing paper feed amount is changed by controlling the paper feeding amount. 6. The print head according to claim 1, wherein the print head is an inkjet head having a plurality of nozzles.
The printing device according to claim 5.