JPH0688437B2 - Printer control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A printer control method for detecting the end of a sheet at the time of printing on the back side in a printer having a sheet reversing mechanism and capable of continuously printing the front side and the back side of the sheet, and a mechanism of a sheet detecting means is simple. And a paper detecting means for detecting the presence or absence of paper at the leading edge of the paper, which is provided on the paper inlet side at the print head position, and a paper inlet at the print head position. The paper reversing mechanism provided on the opposite side of the paper and the number of feed pulses from when the paper detecting means detects the presence of paper to when the paper is not detected at the time of printing on the surface of the paper, and corresponds to the paper length. When the back side of the paper is printed by using the paper length detecting means for storing the number of pulses, the paper length is first detected by the paper length detecting means at the time of printing on the front surface of the paper, and then the paper is reversed by the reversing mechanism. After reversing, only the paper is fed in the direction of the suction port, the leading edge of the paper is detected by the above-mentioned paper detecting means, and then the paper is fed back to the reversing mechanism to the print position of the first line, and from there, in the direction of the suction port. While the paper is being fed, the back side is printed, and at this time, the paper length detecting means starts counting the number of feed pulses after the paper detecting means detects the leading edge of the paper. When the number of pulses has reached the limit, it is judged that the paper has reached the end, and the discharge control is controlled.

[Industrial application field]

The present invention relates to a printer control method for detecting the end of a paper at the time of printing on the back surface in a printer having a paper reversing mechanism and capable of continuously printing on the front surface and the back surface of the paper.

In recent years, various printers have been developed that can continuously print on the front surface and the back surface of paper.

The present invention provides a simple paper end detection method at the time of printing on the back surface, which is necessary for continuously printing the front surface and the back surface of the paper.

[Conventional technology]

A sheet end detection example of a conventional printer that continuously prints the front surface and the back surface of a sheet will be described with reference to FIGS. 6 and 7.

FIG. 6 is a schematic view of a conventional example of a printer, and FIG. 7 is a flowchart for detecting the paper end in the conventional example of FIG.

In FIG. 6, 1 is a print head, 2 is a platen, paper (not shown) and ink ribbon are inserted between the print head 1 and the platen 2, and a CPU (not shown) is also shown.
The print head is driven in response to a command from the printer to print.

A paper detection sensor 3 detects the leading edge and the trailing edge of the paper when the surface of the paper is printed, and controls the presence / absence of the paper by counting the number of paper feed pulses and the count of paper absence. . Reference numeral 4 is a paper feed roller, 5 is a paper inlet / outlet port, 6 is a paper guide, and 7 is a guide drum, which together with the paper guide 6 serve as a guide for reversing the paper. 8
Is a paper detection sensor that detects the leading edge and the trailing edge of the paper when the paper is reversed, and controls the paper presence count and the paper absence count in the same manner as the paper detection sensor 3.

A is a printing unit, which is a print head 1, a platen 2, a paper detection sensor
3, a paper feed roller 4, and a paper detection sensor 8.

Further, B is a paper reversing portion, which is composed of a paper feed roller 4, a paper guide 6, and a guide drum 7.

A printer having such a configuration will be described with reference to the flowchart of the processing for detecting the end of paper in FIG.

Line feed (line feed) from the main unit (not shown)
Is executed (71).

Based on this execution command, the excitation phase of the pulse motor that feeds the paper is switched to start feeding the paper (72).

When the leading edge of the paper is detected by the paper detection sensor 3, the first position according to the format set by the main body device from that position is detected.
When the paper is fed to the line print position, printing of the first line is started (73).

The paper out count is cleared by the ON signal of the paper detection sensor 3 (74).

When the paper detection sensor 3 cannot detect the paper,
Count up the paper-free count (75).

Compare if the out-of-paper count is greater than the specified out-of-paper count (76).

If the out-of-paper count is greater than the specified out-of-paper count, the out-of-paper process is performed (77).

Clear the out-of-paper count (74), and if the out-of-paper count is not greater than the specified out-of-paper count, return to the original and repeat the next execution (78).

After printing the front surface of the paper, the paper is inverted by the reversing unit B, and the leading edge of the paper is detected by the paper detection sensor 8. The subsequent operation is exactly the same as when printing on the surface of the paper.

[Problems to be Solved by the Invention]

The conventional printer as described above has a problem that it is uneconomical in terms of cost because it has two mechanisms that perform exactly the same operation in order to detect the paper at the time of printing each of the front surface and the back surface of the paper. .

An object of the present invention is to realize an inexpensive printer by simplifying the mechanism of the paper detecting means.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention is provided with a sheet detecting means provided on the side of the sheet inlet of the print head for detecting the presence or absence of paper at the leading edge of the sheet and the sheet inlet of the print head. The paper reversing mechanism provided on the side and the number of feed pulses from when the paper detection unit detects the presence of paper to when it detects the absence of paper at the time of printing on the surface of the paper, and counts the number of pulses corresponding to the paper length. Using the paper length detection means to store,
When printing on the back side of the paper, first, when the front side of the paper is printed, the length of the paper is detected by the paper length detecting means, and then the paper is reversed by the reversing mechanism, and then only the paper is fed in the direction of the suction port. Is detected by the paper detecting means, and then the paper is sent back to the reversing mechanism to the print position of the first line,
The back side is printed while feeding the paper toward the suction port from there, and at this time, the paper length detecting means starts counting the number of feeding pulses after the paper detecting means detects the leading edge of the paper, and at that time When the number of pulses reaches the stored number of pulses, it is determined that the paper is at the end and discharge control is executed.

[Action]

In the present invention, since the printing on the front surface and the back surface of the paper is controlled by the same paper detecting means, the control procedure is slightly complicated, but the mechanism is simple and an inexpensive printer can be provided.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a mechanism explanatory view of an embodiment of a printer according to the present invention, FIG. 2 is a block diagram of an embodiment of a printer according to the present invention, and FIGS. 3A and 3B are paper feed control according to an embodiment of the present invention. FIG. 4 is a flow chart of a process for measuring the paper length during printing on the front side of the paper in the embodiment of the present invention, and FIG. 5 is a flow chart of a process for detecting paper shortage during printing on the back side of the paper in the embodiment of the present invention. .

In FIG. 1, the paper detection sensor 8 is removed from FIG. 6, and the other mechanical structure is the same as the conventional one.

In FIG. 2, 10 is a CPU, 11 is a main unit, 12 is an interface, and the CPU 10 and main unit are connected. 13 is a data storage RAM that has a count with paper and a count without paper,
Reference numeral 14 is a program storage ROM for storing a printer control program or characters, 15 is a line buffer capable of storing one line of printing, and 16 is a hammer driver for driving the hammer of the print head 1. Reference numeral 17 is a motor driver, 18 is a carrier moving motor, 19 is an LF (line feed) motor, and 20 is a reversing section B motor. Each motor 18 to 20 is driven by the motor driver 17.

Paper feed control during backside printing in the printer according to the embodiment of the present invention will be described with reference to FIGS.

In response to an execution command from the main body device 11, the CPU 10 rotates the paper feed roller 4 and sends the paper 9 sucked from the paper suction / discharge port 5 to the printing unit A. The number of pulses sent after the paper 9 passes through the paper detection sensor 3 is counted by the paper presence count built in the data storage RAM 13. The paper 9 is fed to the print position of the first line while counting the feed pulses (see FIG. 3A).

Printing and line feed are repeated on the paper 9 by the mechanism shown in FIG. 2, counting is continued until the paper 9 is no longer present on the paper detection sensor 3, and the result is stored in the data storage RAM 13 ( See FIG. 3A).

The paper 9 is further printed up to the bottom of the paper 9 (see FIG. 3A).

After that, the printed sheet 9 is reversed by the reversing section B (see FIG. 3A), enters the printing section A again, and is fed until the sheet detection sensor 3 detects the leading edge of the sheet 9 ( See FIG. 3B).

Since the distance between the paper detection sensor 3 and the print head 1 is fixed and known, the paper 9 is fed back by a predetermined count number to set the first line on the back surface to the printing position (third position).
(See Figure B).

Printing and line feed are repeated while counting the number of pulses sent from the paper 9 with the paper presence count, and when the count number reached in FIG.
Is discharged from the discharge port 5 (see FIG. 3B).

It should be noted that when printing the back side of the paper 9, a program is prepared in advance so that the editing is automatically reversed from that when printing on the front side.

Next, an embodiment of the present invention will be described with reference to the flowcharts shown in FIGS. 4 and 5.

FIG. 4 is a flow chart of the process for measuring the paper length during the front surface printing of the paper 9 in the embodiment of the present invention, and FIG. 5 is a flow chart for detecting the paper shortage during the back surface printing of the paper 9 in the embodiment of the present invention.

The flowchart of FIG. 4 will be described.

An execution command is issued from the main body device 11 to print on the front surface of the sheet 9 (41).

This execution command switches the excitation phase of the pulse motor that drives the paper feed roller 4 (42).

When the paper 9 is fed by the paper feed roller 4 and the leading edge of the paper 9 is detected by the paper detection sensor 3 (43), the data is stored.
Increase the paper count in RAM13 (4
Four).

Clear the paper-free count in the data storage RAM 13 (4
Five).

When the paper 9 is not detected by the paper detection sensor 3, the paper out count in the data storage RAM 13 is counted up (46).

If the out-of-paper count is larger than the predetermined out-of-paper count (47), the out-of-paper process is performed (4
8).

If the paper-out count is cleared, or if the paper is not out, return to the original and prepare for printing the next line (4
9).

By counting the feed pulses of the sheet 9 in this manner, the length of the sheet 9 can be measured during printing on the surface of the sheet.

Next, the flowchart of FIG. 5 will be described.

The excitation phase of the LF motor 19 is switched (52) by the reverse LF execution command (51) during printing on the back side of the paper.

At this time, the paper presence count in the data storage RAM 13 is counted down (53). This paper presence count is counted down from the pulse number of the paper length obtained in FIG.

If the paper present count reaches zero (54), paper out processing is performed (55).

If the paper does not run out, return to the original and wait for the next execution command.

〔The invention's effect〕

According to the present invention, the paper detection sensor is used both for printing the front surface of the paper and for printing the back surface of the paper.

[Brief description of drawings]

FIG. 1 is an explanatory view of a mechanism of a printer according to an embodiment of the present invention, FIG. 2 is a block diagram of a printer according to an embodiment of the present invention, and FIG.
A and FIG. 3B are explanatory views of the paper feed control in the present invention, FIG. 4 is a flowchart of a process for measuring the paper length during front surface printing in the embodiment of the present invention, and FIG. 5 is during back surface printing in the embodiment of the present invention. 6 is a flow chart of the process for detecting the paper shortage, FIG. 6 is a mechanism explanatory view of the printer in the conventional example, and FIG. 7 is a flow chart of the process for detecting the paper shortage in the conventional example. In the figure, 1 ... Print head, 2 ... Platen 3 ... Paper detection sensor, 4 ... Paper feed roller 5 ... Paper inlet / outlet, 6 ... Paper guide 7 ... Guide drum, 9 ... Paper

Claims (1)

[Claims] 1. A paper detecting means for detecting the presence or absence of paper at the leading edge of the paper, which is provided on the side of the paper inlet of the print head, and the paper provided on the side opposite to the paper inlet of the print head. A reversing mechanism and a paper length detecting means for counting the number of feed pulses from the detection of the presence of paper to the detection of the absence of paper at the time of printing on the front side of the paper and storing the number of pulses corresponding to the paper length. When printing on the back side of the paper, first the paper length is detected by the paper length detection means when printing on the front surface of the paper, and then the paper is reversed by the reversing mechanism and then only the paper is fed toward the suction port. The leading edge of the paper is detected by the above-mentioned paper detection means, and then the paper is sent back to the reversing mechanism to the print position of the first line,
The back side is printed while feeding the paper toward the suction port from there, and at this time, the paper length detecting means starts counting the number of feeding pulses after the paper detecting means detects the leading edge of the paper, and at that time A printer control method characterized in that when the number of pulses reaches the stored number of pulses, it is judged that the end of the paper has been reached, and discharge control is performed.