JPH0421482A - Printer with paper width detector - Google Patents

Abstract

PURPOSE:To ensure printing in the full printable area of paper and to minimize the reduction of a printing speed by a method wherein printable left end right end positions are previously calculated on the basis of the inclination of the paper before the start of printing per line. CONSTITUTION:A paper width detector 3 is a reflection-type optical sensor. A printer comprises a control means 9 containing a control circuit for controlling a printing head 2, the paper width detector 3, a carriage motor 4, a line feed motor 7, and the like. A carriage 1 is moved longitudinally, and a paper left end L1 and a right end R1 are measured by the paper width detector 3. A travel amount of paper when the paper is fed from a paper upper end to a top margin position is T. At this position, a paper left end is LT and a paper right end is RT. The inclination of the paper calculated by a formula (LT-L1)/T is stored as dL. Where the paper is fed by a travel amount V, a printable left end at this position calculated by a formula LT+dLXV+M is LV, and a printable right end calculated by a formula RT+dLXV-M is RV. Where the left end of printing data is LD and the right end is RD, whether LV is larger than LD or RV is smaller than RD is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device using a wire tod head or an inkjet head.

[Conventional technology]

Most printers using conventional wire tod heads or inkjet heads do not have a means to detect the width of the paper to be printed, and as a result, print data that exceeds the width of the paper is sent from the host computer. In this case, printing is performed outside the paper, and in this case, printers using wire tod heads have problems such as wires breaking when printing on the boundaries of the paper. Further, in printers using inkjet heads, problems occur in that ink adheres to the platen and stains the next sheet of paper.

In order to solve this problem, an increasing number of printers have recently been equipped with a paper width detector on the carriage to measure the width of the paper before printing, thereby ensuring that printing can be performed within the paper.

[Problem to be solved by the invention]

However, in printers equipped with paper width detectors such as those mentioned above, the print-prohibited area within the paper is set large to allow for diagonal insertion of the paper. Problems such as not being able to fully enter have been occurring.

On the other hand, if print data is to be placed all over the paper, it is necessary to measure the width of the paper immediately before nail printing, and such a method results in a decrease in printing speed.

[Means to solve the problem]

The present invention was devised to solve the above problem, and calculates the degree of inclination of the printing paper when it is taken into the printer, and uses this degree of inclination to calculate the degree of inclination of the paper before starting nailing printing. By calculating the printable left end position and right side position in advance, it is possible to ensure that printing is performed within the paper, and also to print within the paper.

Furthermore, by measuring the paper width only when the paper is taken in, the reduction in printing speed is attempted to be minimized.

〔Example〕

The present invention will be explained in detail based on examples.

FIG. 1 is a perspective view of a printer according to an embodiment of the present invention. A carriage 1 is equipped with a print head 2 and a paper width detection device 3, and is moved in the direction of the arrow by driving a carriage motor 4 via a heald 5. A platen 6 feeds the printing paper 8 by driving a line feed motor 7.

The paper width detection device 3 is a reflective optical sensor, and has the highest reflectance on the paper and the lowest reflectance on the black platen, so it can easily detect the boundary between the paper and the platen. 9 is the print head 2, paper width detector ra
3. A control means including a control circuit for controlling the carriage motor 4, line feed motor 7, etc.

FIG. 2 is a block diagram of a control system of a printer according to an embodiment of the present invention. 10 is a central processing unit (CPU), and DAT
Via the A signal line 11 and ADDRESS signal line 12,
ROM13 that stores control programs and character fonts
, a RAM 14 that is read and written as a print buffer and a data receive buffer, a print control section 15, and a data reception section 16, and receives data from a host computer 17 to execute a printing operation.

The print control section 15 controls each operating means during printing, and in the illustrated example, controls the print head 2 via a head driver 18 and the line feed motor 7 via an LFM (line feed motor) driver 20. ,CRM
(Carriage Motor) The carriage motor 4 is configured to be controlled via a driver 21. Further, an input signal from the paper width detection device 3 is input to the print control section 15 via the receiver 22.

FIG. 3 is a flowchart showing a control operation procedure according to an embodiment of the present invention. First, in step 100, the printing paper is fed, and the position where the paper width detector is stably turned on is determined as the top edge of the paper. Next, proceed to step 101, move the carriage 1 left and right and measure the left and right edges of the paper using the paper width detection device i13.The left edge is Ll and the right edge is R.
Remember it as 1. Next, in step 102, the paper is fed to the top margin position, and the amount of movement from the two ends of the paper is stored as T. The area from the top margin position to the top edge of the paper is an area where printing is impossible, and various values are taken depending on the control system of the printer. At this position, the process moves to step 103, where the left and right edges of the paper are measured again, and the left edge is stored as LT and the right edge as RT. This is 1
Move to step 04 and set the degree of inclination of the paper (LT-Ll).
/T is calculated and stored as dL. Next, the process proceeds to step 105, where the received data written in the receive buffer in the RAM 14 from the host computer is taken out one after another, and in the case of character data, character fonts are developed and written in the print buffer.

Next, in step 106, one line of data taken out is determined to be line movement data. 1 for row movement data
The process advances to step 07 and the paper is fed by a predetermined amount.

Thereafter, the process advances to step 108, and the amount of movement from the top margin position is stored as V. Next, in step 109, set the printable left edge position at this position to LT+dL.
Calculate using the formula xV+M and store as LV. Also, calculate the printable right edge position using the formula RT+dLxV-M, and
Store it as V. Here, M is the accuracy of the paper width detection device,
This is a margin value that takes into consideration the mounting accuracy between the print head 2 and the paper width detection device 3. This completes the processing of the line movement data, and the process returns to step 105 to retrieve the next data.

It is determined in step 110 whether the one line of data extracted in step 106 is print data. If it is print data, the process advances to step 111, and from one line of print data, the left end of the print data is stored as LD and the right end as RD.

Next, the process advances to step 112, where the printable left end (LV) and print data left end (LD) are compared to determine whether LV is larger than LD. 11 if LV is greater than or equal to LD
Proceed to step 3 and store the LV as the print execution left end (LP). If LV is smaller than LD in step 112, proceed to step 104 and store LD as LP.0 Next, proceed to step 115 and select the printable right end (RV).
and the right end (RD) of the print data to determine whether RV is smaller than RD. If RV is less than or equal to RD, the process advances to step 116 and RV is stored as the print execution right end (RP). If RV is greater than RD in step 115, the process advances to step 117 and RD is stored as RP. Next, proceed to step 118 and print at the left end (LP
) and print right! Execute printing within the range of 1ift (RP). When printing is completed, the process returns to step 105 to process the next data.

In the embodiment, the position was determined for each line or for each movement of the carriage 1, but depending on the degree of inclination of the paper, n
It is also possible to determine the position for each line and every n movements of the carriage 1, and the overall speed can be further increased.

FIG. 4 illustrates the above explanation.

As described above, according to the present invention, the only area in which printing is not possible is the accuracy of the paper width detector and the mounting accuracy of the print head and the paper width detector, as described above.

Therefore, at worst, only about 1 mm on either side becomes an area where printing is impossible.

In contrast, in the conventional method, it is necessary to take into account the inclination caused by inserting the paper. Even if the paper feed mechanism, paper guide, etc. are devised, the tilt caused by inserting the paper will be ±0.3.
About 1 occurs. Therefore, for A4 size, it is 297mm.
xtan0.3@=1.6mm, and adding paper width detector accuracy and paper width detector mounting accuracy to this, it becomes 4.2 for left and right.
The unprintable area is about mm. FIG. 5 shows the print area according to the present invention, and FIG. 6 shows the print area according to the conventional method, and it can be seen that the print area according to the present invention is wide.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, printing can be performed reliably on printing paper, the printing area can be secured to the maximum, and there is no need to worry about missing data. Furthermore, the time required to detect the paper width is short, making it possible to minimize the decrease in printing speed, which has great effects.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a printer according to an embodiment of the present invention, FIG. 2 is a block diagram of a control system according to an embodiment of the present invention, FIG. 3 is a flowchart showing a control operation procedure according to an embodiment of the present invention, and FIG. 4 5 is a diagram to supplement the flowchart of the present invention, FIG. 5 is a diagram showing a print area according to the present invention, and FIG. 6 is a diagram showing a print area according to a conventional method. Applicant Seiko Epson Co., Ltd. Agent Patent Attorney Kizobe Suzuki and 1 other person Figure 4 Figure 6

Claims (1)

[Claims] In a printer equipped with a moving carriage, a print head mounted on the carriage, and a paper width detection device, the paper width detection device measures the degree of inclination of the paper taken in at the time the paper is taken into the printer. and a second means for determining the print start position and print end position for each at least one movement of the carriage based on the degree of inclination measured by the first means. printer.