JPH01271277A - Paper finish detection - Google Patents

Abstract

PURPOSE:To prevent blind printing by stopping paper feed before the terminal of paper reaches a printing position, by indexing the finish position of paper with due regard to the position where the terminal of the paper is detected and the feed quantity from said position. CONSTITUTION:The control part 20 of a line printer 1 prints the data inputted from a host computer 12 through an interface control part 21 by the operation of a printing control part 22 and that of a paper feed control part 23. When the terminal of paper is detected by a paper exhaustion detecting switch 11, the interface control part 21 indexes the finish position of the paper on the basis of the detected terminal of the paper and the feed quantity of the paper fed from the paper terminal position toward a printing position through the paper feed control part to output a signal, which stops paper feed and printing operation before the thermal of the paper reaches the printing position, to the printing control part 22 and the paper feed control part 23. By this method, blind printing is prevented and the disappearance of printing data can be prevented.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a paper end detection method for line printers that detects the end of printing paper that is being fed at high speed and stops paper feeding. The purpose is to determine the paper end position by considering the paper feed amount from that position, and when the paper end is detected while paper is being fed, the interface controls the paper feed amount beyond the paper end detection position. In this method, the interface control section determines the sheet end position from the detected end of the sheet and the received feed amount.

[Industrial application field]

The present invention relates to a paper end detection method for a line printer that detects the end of printing paper that is being fed at high speed and stops paper feeding.

(Prior Art) In the conventional line printer 1, as shown in FIG. 6, a top cover 3 that opens upward is rotatably attached to the top surface of the forms rack 2, and a front cover that opens forward is attached to the front of the forms rack 2. A door 4 is rotatably attached, a paper feed unit 5 is provided in the second part of the forms rack 2 covered by the top cover 3, a print unit 6 is provided in front of the paper feed unit 5, and paper 7 for printing is placed below this. A forms guide 9 forms a hopper 8 for storing the paper and guides the paper 7 toward the print unit 6 at the upper part of the hopper.
EOF detection plate 1 is installed on the front of the form guide 9.
0 is provided, and the EOF detection plate 10 is pressed against the forms guide 9 side, so that the paper out detection switch 11 built into the forms guide 9 can be operated by the EOF detection plate 10.

The EOF detection plate 10 is located at the lower end of the EOF detection plate 10 when the paper 7 is held between the forms guide 9 and the EOF detection plate 10, as shown in FIGS. 7(a) and 7(b). is obstructed by the paper 7 and the paper out detection switch 1
] , and the lower end of the paper 7 moves above the switch contact part i0a provided at the lower end of the EOF detection plate 10, the switch contact part 10a
The paper-out detection switch 11 can be pressed without being disturbed by the paper-out detection switch 11, and it is possible to indicate that the paper-out detection switch 11 is about to run out.

When the paper 7 runs out, the switch abutting portion 10a presses the paper out detection switch 11, but the paper remaining between the position of the form guide 9 where the paper out detection switch 11 is provided and the printing position of the print unit 6 is Since there is a considerable amount of paper 7 that has been removed, it is necessary to estimate the remaining amount.

In this case, the paper out detection switch 11 is turned on.
When the end of the paper is detected), if there are N inches remaining in the cross print section, then n (n<N) inches are printed and then the paper is finished and stopped.

(Problems to be Solved by the Invention) In the conventional learn printer 1 described above, during this paper feeding,
When the paper out detection switch 3.1 was turned on and the near end was detected, it was not known at what point in paper feeding the paper reached near, end, or end, and the near end detection position for that paper was set at the position where it stopped. .

For this reason, the amount of paper 7 that moves toward the printing position from near-end detection to paper feeding stop is not constant, and in some cases, printing may occur even though there is no paper 7 at the printing position. , resulting in loss of print data and damage to the print head. In addition, in order to prevent this, if the long paper feed is divided into one line at a time and the paper out detection switch 11 is turned on every time the paper is fed one line, the paper feed speed will be reduced. There is a problem that the processing speed becomes slow and the processing efficiency decreases.

The present invention has been made in view of the above-mentioned problems, and the technical problem set for solving the problem is to detect the end of the paper by taking into consideration the position where the end of the paper is detected and the feed amount from that position. An object of the present invention is to provide a paper end detection method that determines the position.

[Failure to solve the problem]

As a specific means for solving the above problems, the present invention provides a method for detecting the end of paper in a printer in which the printing position and the end detection position of the paper sent to the printing position are far apart, as shown in FIG. As shown, the end of paper 7 was detected (step 16) during paper feeding (step 15).
In this case, the feed amount of the paper 7 that advances beyond the paper end detection position is input to the interface control unit 21 (step 17), and the interface control unit 21 inputs the detected end of the paper 7 and the received feed base. The paper end position is determined from (step 18).

[Effect]

According to the above configuration, when the end of the paper 7 is detected during paper feeding, the interface control unit 21 detects the detected end of the paper 7 and the paper 7 sent to the print position side from the paper end detection position. It is now possible to determine the paper end position from the feed amount and control the paper feed to stop before the end of the paper 7 reaches the print position, eliminating the need for blank printing and eliminating print data. This prevents the printing head from being damaged, protects the print head, and eliminates the need to reduce the feeding speed of the paper 7.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a case where paper end management is programmed and executed by an interface control section provided in a control section of a line printer will be illustrated and explained below.

As shown in FIG. 2, the control unit 20 of the line printer 1 communicates with the host computer 12 and the interface control unit 21.
A print control unit 22 and a paper feed control unit 23 are connected to this interface control unit 21, and each prints the data input from the host computer 12, and also feeds the paper 7 at a paper feed speed that matches the printing. Let it be supplied.

A paper end detection switch 11 is connected to the paper feed control unit 23 so that the detection of the end of paper can be input.

As shown in FIG. 3, the end management method for the paper 7 is carried out by controlling the print control section 22 and paper feed control section 23 according to a program stored in the interface control section 21.

First, as an initial value, the number of paper feed pitches that can be fed from the time of near-end detection until the end of the paper 7 is moved to the printing position is entered in a register called PFDATA. PNEND again.

Put 0 in the flag called PEND (Step 3)
1).

Next, check whether data necessary for printing one line has been received from the host computer 12 (step 32). If not, wait until it is received; if it has been received, proceed to the next step and set PNEND to 1. (Step 3)
3).

If PNEND is 1, the paper feed pitch number P of the data input from the host computer 12 side from PFDATA.
(step 34), then PFDATA is O
Check whether it is less than or equal to O (step 35), and if it is less than O, set PEND to 1 (step 36), and if it is greater than 0, skip step 36 and proceed to step 37.

If PNEND is not 1, a print command is sent to the print control section 22 to print one line (step 37), and after printing, a paper feed command is sent to the paper feed control section 23 to execute paper feed for one line. (Step 38).

After that, check whether PEND is 1 (step 39),
If D is 1, this control is terminated (step 40), and P
If END is not 1, proceed to the next step and check whether the end of paper 7 has been detected (step 41).
), if not detected, return to step 32; if detected, proceed to the next step and check whether PNEND is 1 (step 42).

If PNEND is 1, return to step 32 and PNEND
If is not 1, get the paper feed pitch number PEP from PFDATA.
ITCH is subtracted and PNEND is set to 1 (step 43), and the process returns to step 32.

When this control is finished in step 40, the state is kept in standby until the paper 7 is set, and when the paper is ready,
Return to the initial state.

When a paper feed command is sent from the interface control unit 21 to the paper feed control unit 23, the paper feed control unit 23 performs the following operations.
As shown in FIG. 4, first, it is checked whether a paper feed command has been input (step 51), and if it has not been input, wait; if it has been input, the number of paper feed pitches is entered in register A (step 52); Execute paper feed for one pitch (
Step 53). After paper feeding, 1 is subtracted from register A (step 54). Then, it is checked whether register A is 0 (step 55), and if it is not 0, the process returns to step 53, and if it is 0, the error during paper feeding is sent back to the interface control unit 21 (step 56), and then the process returns to step 51. return.

When the paper out detection switch 11 is turned on, an interrupt is generated and the register A is set as shown in FIG.
Store the contents of to PEPITCH (step 57),
PEPI along with near-end detection information when replying an error
The contents of the TCH are transmitted to the interface control unit 21 side.

In this way, in this embodiment, it is constantly monitored whether the end of the paper 7 reaches the position of the paper out detection switch 11 and the switch is turned on, and when the end of the paper is detected, the paper feed control unit 23 starts the interface control. The feed amount from that position is reported to the interface control unit 21.
By subtracting the feed amount from FDATA, the paper 7 can be used effectively as long as the paper 7 is not left in the printing position.

〔Effect of the invention〕

As described above, the present invention uses a paper end detection method that determines the paper end position by taking into account the position at which the paper end is detected and the feed amount from that position, so that the end of the paper 7 is detected during paper feeding. After that, the paper feed can be stopped before the end of the paper 7 reaches the printing position, preventing blank printing, preventing the loss of print data, protecting the print head, and furthermore, the paper feeding can be stopped before the end of the paper 7 reaches the printing position. No need to reduce speed.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing a paper end detection method according to the present invention. FIG. 2 is a configuration diagram showing a control section of a line printer according to an embodiment. FIG. 3 is a diagram showing processing of an interface control section according to an embodiment. Flowchart: FIG. 4 is a flowchart showing the processing of the paper feed control unit according to the embodiment; FIG. 5 is a flowchart showing the interrupt processing according to the embodiment; FIG. 6 is a side explanatory diagram showing a conventional line printer; FIG. 7 is an explanatory side view showing a conventional paper-out detection method. 5...Paper feed unit 1-6...Print I unit 7...Paper 10...EOF detection plate 11...Paper out detection switch 20...Control unit 21...Interface control unit 22...Print control unit 23...Paper feed control unit misfire August 1-Due paper outside 3 sheets Kameko type 1j, 1 Tang, Unzu 1st Agony Award @ Italy Line Printer H Wholesale Temporary pt *1 O-nose relation Diagram 2 Diagram 584 Showing the processing of the paper feed control section by operation (1 movement) There is one missing t on the thread (a) A thousand buttons are stabbed with a knife on a stack of paper. 7th one-eyed, four-pronged form (b) and the t is on one side.

Claims (1)

[Claims] In a printer where the printing position and the end detection position of the paper sent to the printing position are far apart, when the end of the paper is detected during paper feeding, the paper advances beyond the paper end detection position. (7) The feed amount is input to the interface control unit (21), and the interface control unit (21) determines the paper end position from the detected end of the paper (7) and the received feed amount. paper end detection method.