JP3047570B2 - Printing paper guide device in printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for feeding printing paper.
The present invention relates to a printer capable of smoothly performing operations such as discharging.

[0002]

2. Description of the Related Art Conventionally, a nose portion of a print head mounted on a carriage of a printer is disposed so as to face a platen, and the carriage can be moved left and right along a platen surface. By attaching a paper presser plate facing the front surface to the carriage and moving the carriage substantially at the center in the width direction of the printing paper, a minute gap between the platen and the nose portion of the printing head in the printing apparatus when feeding and discharging the printing paper. To allow the printing paper to pass smoothly.

[0003]

In this case, since the width of the printing paper to be supplied is various, if the stop position of the carriage is uniformly determined to be substantially the center of the length of the platen, When printing paper having a short width is supplied to the leftward or rightward portion of the platen length on the platen, the stop position of the carriage becomes near the width edge of the paper, thereby preventing the paper from jamming (paper jam phenomenon). There is a problem that the effect is small. As means for solving this problem, a sensor means for directly detecting the width dimension of the printing paper or a guide body on both right and left side edges of the printing paper is configured to be movable left and right, and the left and right guide bodies are stopped ( It is conceivable to separately provide a means for detecting the (installation) position, but this would increase the number of components and increase the cost of the printer.

The present invention relates to a printer in which the carriage is moved to a substantially central portion in the width direction of the printing paper at the time of paper feeding or the like by using print data for printing on printing paper without providing the sensor and the like. It is intended to provide.

[0005]

According to the present invention, there is provided a printing paper for use in a printer according to the present invention.
The guide device includes a carriage driving unit that moves a print head mounted on the carriage in a state of facing a platen extending in a width direction of the printing paper, and a paper feeding unit that sends the printing paper in a direction intersecting with the carriage moving direction. Print duty is higher than the specified value
Determining means for determining how low, calculating means for calculating a value corresponding to the right end position of the print line, storage means for storing a value corresponding to the rightmost position among the calculated values,
The print duty is regulated based on the determination result of the determination means.
When higher value performs control Before moving the carriage to the estimated center position of the stored estimated from the rightmost position corresponds to a value sheet width direction substantially half the printing
When the duty is lower than the specified value, the carriage
Not to execute the control to move to the estimated center position.
Is obtained by a control means you.

[0006] The invention described in claim 2 is the invention according to claim 1.
Printing paper guide device in the printer described in
The control means detects whether there is print data to be printed.
Notice, after the printing work is completed, before discharging the printing paper,
So that the carriage is forcibly moved to the estimated center position.
To control.

[0007]

DETAILED DESCRIPTION OF THE INVENTION the present invention will now Embodiments <br/> embodying be described. The carriage 2 of the printer 1 is slidably fitted on a guide shaft 5 disposed along the longitudinal direction of a platen 4 having a rectangular column shape in cross section and provided on a pair of left and right frame side plates 3a and 3b of the frame. An auxiliary guide shaft 7 disposed in parallel with the guide shaft 5 is loosely fitted in a guide groove 6 formed in a rearward U-shape at the rear end of the carriage 2 so as to be movable left and right and back and forth.

The timing belt (drive belt with tooth profile) 8 attached to the lower surface of the carriage 2
The carriage 2 is wound around a pulley 9a rotatably supported by a and a pulley 9b attached to a drive shaft of a carriage driving motor M1, so that the carriage 2 moves left and right along the platen 4.

Also, eccentric shafts 5a are protrudingly provided at the left and right ends of the guide shaft 5, and both eccentric shafts are rotatably supported by shaft supporting holes formed in the left and right side plates of the frame. The carriage 2 is configured to be able to contact and separate from the platen 4 by the contacting / separating mechanism 11, and a printing wire (not shown) protruding from a nose portion 10 a at the tip of a print head 10 mounted on the carriage 2 and a platen 4. It is configured such that the size of the printing gap (gap) with the printing paper on the front surface can be adjusted. The print head 10 of this embodiment is of a dot matrix impact type in which a plurality of print wires are protruded from a nose portion 10a via a drive unit such as an electromagnetic device or a piezoelectric element built therein to execute printing.

Reference numerals 12, 13, 14, and 15 denote a pair of feed rollers provided on the downstream side and the upstream side of the transport of the printing paper P with the platen 4 interposed therebetween. Drive motor 16, timing belt 17
And the print paper P is held by at least one of these roller pairs and the platen 4 is rotated.
This is a so-called straight path type in which the paper is conveyed in a substantially straight line along the top.

A feed guide path 19 disposed below the carriage 2 is provided with feed roller pairs 20 and 21. The cut print paper P is fed to a manual feeder or an automatic feeder (not shown). The paper is fed toward the upstream roller pair 12, 13. Reference numeral 22 denotes a guide plate extending in the direction of the platen 4 from the upstream roller pair 12, 13, and reference numeral 23 denotes the guide plate 2.
2 is a paper pressing plate arranged so as to face 2. Sign 2
Reference numeral 4 denotes a carriage paper guide which is attached to the carriage 2 and extends in the direction of the platen 4 and the pair of downstream rollers 14 and 15 from the back side of the paper holding plate 23. It serves as a guide to ensure that the leading end of P is fed into the downstream roller pair 14,15. After the printing operation, when the single-sheet printing paper P is fed backward in the feed guide path 19 and discharged, the slack generated near the platen 4 and the paper holding plate 23 is reduced by the carriage paper. The guide 24 plays a role of suppressing. Reference numeral 25 denotes the carriage 4
And a paper guide plate positioned between the first and second pairs of downstream rollers 14 and 15 so as to face the carriage paper guide 24.

The continuous printing paper P2 conveyed by a tractor unit 26 composed of a pin tractor driven by the driving motor 16 is fed from between a guide plate 22 and a paper pressing plate 23 to the upstream roller. The rollers are fed to pairs 12 and 13, pass through four platens, and are connected to downstream roller pairs 14 and 1.
It is discharged from the 5 side. The continuous printing paper P3 from the other tractor unit 27 is sent from the platen 4 to the downstream roller pair 14, 15 via the curved guide passage 28.

FIG. 4 illustrates a phenomenon in which the nose portion 10a of the print head and the paper holding plate 23 are not provided substantially at the center in the width direction of the single-sheet printing paper P. When printing is performed on the leading edge of the paper in a quality print mode or the like, the printing paper P tends to warp so that the leading edge rises toward the printing surface. Therefore, when the nose portion 10a of the print head and the sheet holding plate 23 are not provided,
The leading end of the printing paper P is displaced from the paper path, so that the paper cannot be nipped and conveyed by the pair of rollers 14 and 15 on the downstream side. Further, for example, when printing is performed at a high print density on a printing sheet on which a plurality of copy slips are stacked, a gap is easily generated between the plurality of slips.
In particular, the slip sheet on the top layer tends to swell. Therefore, when such a material is conveyed in the reverse direction after printing, the guide plate 2
It is difficult to introduce the sheet into the gap between the sheet 2 and the sheet holding plate 23, and any of these causes a jam.

According to the present invention, these phenomena can be easily eliminated by the following control.

A control device 50 such as a microcomputer shown in FIG. 5 executes the entire drive control of the printer 1 and determines an estimated center position of approximately half of the printing paper P in the width direction. Execute the control to move. A central processing unit (CPU) 51 of the control device 50 has a read-only memory (ROM) 52 storing a control program and a read / write as needed for temporarily storing various data (data such as the number of print digits). It has a possible memory (RAM) 53 and an input / output interface, inputs print data from a host computer 54 via a reception buffer 55, and various operation keys provided on an operation panel 56, for example, a feed key 57, a paper discharge The signals of the keys 58 and the print mode key 59 and the signals of the detection switches such as the paper sensor 30 provided in the supply guide passage 19 and the like are taken into the central processing unit 51, and the carriage driving motor M1,
The paper feed drive motor 16 is driven via drive circuits 60 and 61, and the drive circuit 63 of the print head 10 is operated in accordance with the dot matrix of the print data obtained by developing two consecutive lines of print data in the line buffer 62. Executes the specified printing.

FIGS. 6 and 7 show control flowcharts for setting the position of approximately half the width of the printing paper P in the width direction and moving the carriage. Following the start, the memory is initialized and the read / write memory (RA) associated with the line buffer 62 for two consecutive rows is initialized in step 100.
M), the two memory areas 62a and 62b
Reset the number of print digits K0 and K1 of the print line to zero. As will be described later, one memory area 62a stores and holds only the maximum number of digits K0, and the other memory area 62 stores the number of print digits K1 of the line on which printing has been performed.

Next, the state of the print mode key selected in step 101 is detected, and it is determined whether or not the print duty is higher than a specified value. When the value is higher than the specified value, it is the time of the high-density printing (high-quality printing) mode, and when it is lower than the specified value, it is the time of the draft printing mode, the ruled line printing, or the like. When the printing duty is lower than the specified value, the leading end of the stamp paper P does not reach the downstream roller pair 14 and 15 so that the leading end of the stamp paper P does not warp and the printing operation is performed quickly. Even if there is, the movement of the carriage 2 described later is not executed every time the sheet is fed. The distance from the platen 4 to the pair of downstream rollers 14 and 15 is H1.

If the printing duty is higher than the specified value,
If they are separated (step 101: yes), printing of one line is executed in step 102, and the number of print digits K1 is stored in the memory area 62b in step 103. In step 104, the number of print digits K1 in this memory area 62b is compared with the maximum number of print digits (K0 = 0 initially) stored in one of the memory areas 62a, and if K0 <K1 (yes). ), The data of the large number of print digits is transferred (updated) to one of the memory areas 62a (step 105). If K0 <K1 is not satisfied (no), the large data stored in the memory area 62a is stored. The data of the number of print digits is retained as it is. In step 106, from the maximum number of print digits K0, a calculation is performed to estimate a position L / 2, which is approximately half of the print length B0 in the width direction of the paper, as a substantially central portion of the print paper width Lo. Here, the printing length B0 in the width direction is represented by a product of an interval required for one character (including a character interval) and the maximum number of printing digits. At this time, as shown in FIG. 8, the width dimension M1 (considering the margin amount) from the left end of the printing paper P to the printing start position is also calculated, and the position L / 2 (= B0) is calculated.
+ M1) / 2. Note that the embodiment of FIG. 8 is an example of a sheet that does not have a portion to be printed such as a date and a serial number at the upper right of the sheet. In general, a sheet such as a slip has a portion for printing a date or a serial number at the upper right end, so that the center of the sheet can be estimated almost certainly by the above-described method. Next, in step 107, the number of line feeds of the printing paper P is calculated, and the amount of line feed A converted from the number of line feeds and the upper margin (that is, the distance from the leading edge of the paper to the print line).
Determines whether the distance from the platen 4 to the pair of downstream rollers 14 and 15 is larger than H1, and when A <H1 (no), the carriage 2 is moved before the line feed operation. Is forcibly moved to a predetermined estimated center position L / 2 (step 108). Comparing the first line and the second line in FIG. 8, since the number of print digits on the first line is large, the position of approximately half of the print digits on the first line is estimated to be approximately the center of the width of the printing paper. The carriage 2 is forcibly moved before the line feed to the second line. When the third line is reached, the position of the carriage 2 is almost half of the number of print digits, and in the fourth line, the print digit of the fourth line is used. The processing from step 102 to step 108 is repeated, such that the position of approximately half of the number is assumed to be approximately the center of the width dimension of the printing paper and the carriage 2 before the line feed to the next line is forcibly moved.

Thus, even if the leading end of the cut-sheet printing paper P is warped due to high-density printing, or when the cut-sheet paper is fed, even if the sheet width is short, the print head 10 is positioned substantially at the center. Since the nose portion 10a is set, a substantially central portion in the width direction of the printing paper can be brought extremely close to the platen 4 to suppress the warping, and a jam at the downstream roller pair 14, 15 can be prevented. Can be.

When the result of step 101 is no (printing
When the duty is determined to be lower than the specified value) and
If yes in step 107 (when A ≧ H1)
In step 1, it is determined whether or not there is print data thereafter (step 1).
09), calculates the number of print digits K1 of the line for each printing operation of the subsequent print line, compares the number with the maximum number of print digits K0 before that, and if a large number of print digits appears, the maximum number of previously stored numbers is stored. Only the process of replacing (updating) the number of print digits K0 with the new maximum number of print digits is continued (steps 110 to 11).
3). As a result, the leading end of the printing paper P is
Since reached the position of 4, 15, subsequent jamming is not considered to occur, yet, the printing operation by forcibly moving the carriage before each new line as described above in substantially the center of the sheet width delay In order to prevent this, the forcible movement of the carriage 2 toward the center of the width is eliminated.

When the print data is lost and the printing operation is completed, the last updated and stored maximum number of printing digits K
Based on 0, a calculation is performed to estimate a position L / 2, which is approximately half of the printing width B0 of the paper in the width direction, to be approximately the center of the printing paper width Lo (step 114). Then, prior to discharging the printing paper P in the reverse direction, the carriage 2 is forcibly moved to the estimated center position L / 2 (Step 1).
15). Also in this case, the nose portion 10a of the print head is located substantially at the center in the width direction of the printing paper P. Therefore, when the printing paper P on which printing has been performed is discharged backward in the direction of the supply guide path 19, the swelling of the printing paper P it can be suppressed, and by eliminating the jam when the paper introduced into the gap between the paper pressing plate 23 and the guide plate 22, it is possible to perform a smooth discharge operations.

In the above-described embodiment, it is assumed that a sheet having a portion to be printed, such as a date and a serial number, is used in the upper right portion. However, for example, a case where the printing portion is concentrated only on the left side of the sheet can be considered. In this case, it is not possible to accurately estimate the center position of the right and left sides of the sheet, but in such a case, only the left side of the sheet is likely to be warped or floated, so that the Jams can be reduced compared to placing the carriage paper guide 24 on the left side.

In the same kind of printing operation, the sheet of the next page is often the same width as the sheet of the previous page when feeding the next page. The next page can be fed smoothly while the paper guide is left. In this case, the flowchart of the next page print, and omits the processing in step 100 of the embodiment. Of course, if the sheet width is different from the previous page, it goes without saying that the processing is performed again from step 100 by the operation of the operator.

Further, in the above-described embodiment , the process is executed using the number of digits of the line on which printing has already been performed. However, when a line buffer of three or more lines is used, the print data of the next line is When the data is stored in the line buffer, the data may be considered. Furthermore, if the present invention is embodied in a printing apparatus having a buffer capable of storing print information for one page, it is possible to estimate using the maximum number of printable digits on the page at the start of feeding, so that the carriage The paper guide can be placed at the optimum position.

[0025]

As described above, according to the first aspect of the present invention, there is provided a carriage driving means for moving a print head mounted on a carriage so as to face a platen extending in a width direction of a print sheet; In a printer comprising a paper feeding means for feeding a printing paper in a direction intersecting with the carriage moving direction, the printing duty is determined by the determining means.
While determining whether the value is higher or lower than the specified value, the calculating means calculates the value corresponding to the right end position of each line during the printing operation, and calculates the value corresponding to the rightmost position among the calculated values. By storing in the storage means, a position close to the paper width is always stored, and the paper width dimension can be estimated without separately providing a sensor means.

Then, based on the determination result of the determination means,
When the print duty is higher than the specified value , the carriage is controlled to be moved to an estimated center position substantially half of the sheet width direction calculated from the stored value corresponding to the rightmost position. When the nose portion of the print head is substantially at the center in the width direction of the printing paper on the platen, it is possible to suppress the paper curling phenomenon or the loosening phenomenon during high-density printing work .

As described above, even when printing paper having different width dimensions is used, or when printing paper is fed to an arbitrary position in the longitudinal direction of the platen, the printing paper is followed during a line feed operation or a paper discharging operation. By moving the nose of the print head to approximately the center in the width direction of the printing paper, the paper jam phenomenon can be eliminated very easily.

On the other hand, based on the determination result of the determination means,
When the print duty is lower than the specified value, the carry
Control to move the cartridge to the estimated center position.
To speed up printing during low-density printing
Can be.

[0029] Moreover, according to the present invention, there is no need to separately provide a sensor for detecting the feed position with respect to the longitudinal direction of the width dimension and the platen of the printing paper used, it utilizes the data associated with printing Therefore, there is a remarkable effect that an inexpensive printer can be provided.

The invention described in claim 2 is the invention
The printing paper guide device in the printer according to 1.
The control means detects whether there is print data to be printed.
Notice, after the printing work is completed, before discharging the printing paper,
So that the carriage is forcibly moved to the estimated center position.
Because it is controlled, for example, printing after printing
Prints swelling and warpage of printing paper when paper is ejected reversely
Paper jam due to the nose of the head
That the paper can be discharged smoothly.
It works.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a main part of a printer.

FIG. 2 is a schematic side view of a printing paper feeding mechanism.

FIG. 3 is a side sectional view of a main part of a printing paper guide near a print head.

FIG. 4 is an explanatory diagram illustrating a state of a print sheet when a print head is not positioned on a platen.

FIG. 5 is a functional block diagram of a control device.

FIG. 6 is a flowchart.

FIG. 7 is a continuation of the flowchart in FIG. 6;

FIG. 8 is an operation explanatory view of the embodiment .

[Explanation of symbols]

 2 Carriage 4 Platen 5 Guide shaft 7 Auxiliary guide shaft M1 Carriage drive motor P Print paper 10 Print head 10a Nose part 11 Contact / separation mechanism 12, 13 Roller pair 14, 15 Roller pair 16 Paper feed drive motor 19 Guide path 20, 21 Feeding roller pair 22 Guide plate 23 Paper press plate 24 Carriage paper guide 30 Paper sensor 50 Controller 51 Central processing unit 62 Line buffer 62a, 62b Memory area

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 29/38 B41J 13/00 B41J 19/18

Claims (2)

(57) [Claims] A carriage driving means for moving a print head mounted on a carriage in a state of facing a platen extending in a width direction of print paper, and a paper feed means for feeding print paper in a direction intersecting the carriage movement direction. In a printer equipped with a printer, it is determined whether the print duty is higher or lower than a specified value.
Another means, a calculation means for calculating a value corresponding to the right end position of the print line, a storage means for storing a value corresponding to the rightmost end position among the calculated values, and a determination result of the determination means. Printing duty
When higher value performs control Before moving the carriage to the estimated center position of the stored estimated from the rightmost position corresponds to a value sheet width direction substantially half the printing
When the duty is lower than the specified value, the carriage
Not to execute the control to move to the estimated center position.
Guiding device of the printing paper in the printer, characterized in that a control means you. 2. The printing apparatus according to claim 1, wherein the control unit is configured to output print data to be printed.
Is detected, and after the printing operation is completed, the printing paper is discharged.
Prior to moving the carriage to the estimated center position.
2. The control method according to claim 1, wherein
A guide device for printing paper in a printer.