JPS6374847A - Paper end detection system - Google Patents

Abstract

PURPOSE:To prevent the stoppage of printing action and the delivery of wrong paper end information from occurring, by making a detection signal so as to be delivered at a time when the paper end information out of a paper end detecting device is continuously outputted while paper feeding for the specified quantity is performed. CONSTITUTION:An output signal 5 out of a paper end detector 1 keeps an on-state even continuing its line feed unless it is bot by format printing, and reset of a counter 3 keeps an off-state so that this counter 3 continues to count a driving pulse 7 of a line-feed stop motor 10, and when a carry is emitted out of the counter 3, an output signal 6 comes one, transmitting it to a control part 4. However, when the signal 5 out of the detector 1 comes on by the format printing, if a format printing part passes through a photosensor by line feed operation, the signal 5 of the detector 1 comes off again, whereby the counter 3 is reset and the signal 6 keeps the off-state so that a paper end detection signal is not transmitted to the control part 4. Thus, an error in paper end detection by the format printing or the like is preventable.

Description

TECHNICAL FIELD The present invention relates to a paper end detection method, and more particularly to a paper end detection method for a serial printer having a paper end detector using a reflective photosensor.

BACKGROUND ART Conventionally, in this type of serial printer, the presence or absence of paper has been detected using a paper end detector that generally uses a reflective photosensor, as shown in FIG.

In FIG. 2, the print head 8 prints by moving parallel to the platen 9 by a lateral feed motor (not shown). Also,
When one line of printing is completed, the line feed step motor 10 rotates the platen 9 via the timing belt 11 to move the paper 12 in a direction perpendicular to the platen 9.

Thereafter, this operation is repeated continuously to perform the printing operation.

During this printing operation, a photo sensor (not shown) in the paper end detector 1 shines light on the paper 12, and if the reflected light 8 is larger than a certain item, it does not indicate the end of the paper and provides paper end information. Paper end information was sent out when the amount of reflected light became smaller than a certain amount.

However, since the photo sensor used the reflected light from the paper 12 to detect the end of the paper, if the paper 12 has been printed with a format, the amount of reflected light will be low even if the printed part is hit by light. As a result, even though there is paper 12, the state is the same as the paper end, and paper end information is sent.

In such conventional serial printers, the paper end sensor 7 of the paper end detector 1 uses reflected light from the paper 12 to detect the paper end, so if a format is printed on the paper 12, the photo The sensor detects the same state as the paper end in the printing area and sends paper end information, causing the serial printer to stop printing or erroneously sending paper end information to the host device. There was a drawback.

Purpose of the Invention The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional method, and prevents errors in paper end detection due to format printing, etc., and prevents printing operation from stopping and incorrect paper end information from being sent to the host device. The purpose of the present invention is to provide a paper end detection method that can prevent the paper from being sent out.

Structure of the Invention The paper end detection method according to the present invention is a paper end detection method for a serial printer having a paper end detection means for detecting the end of paper, the paper end detection method indicating the end of the paper from the paper end detection means. The present invention is characterized in that a paper end detection signal is transmitted when information is continuously output while the paper is fed by a predetermined amount.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, one embodiment of the present invention includes a paper end detector 1 having a photosensor (not shown), an inverter 2, a counter 3, and a control unit 4 that controls printing operations and paper feeding of a printer (not shown). It is made up of.

The configuration of the printing section where the paper end detector 1 detects the paper end is the same as that of the conventional example shown in FIG. 2, and its operation is also the same as that of the conventional example.

An embodiment of the present invention will be described using FIG. 1 and FIG. 2.

The output signal 5 of the paper end detector 1 is inverted by the inverter 2 and input to the reset (R) terminal of the counter 3.

When paper 12 is present, the reset is turned on and the counter 3 does not operate, so its output signal 6 remains off. When the paper reaches the end, the reset of the counter 3 is turned off, and the control section 4 starts counting the drive pulse signal 7 of the line feed step motor 10.

The output signal 5 of the paper end detector 1 remains on even if line feeds continue, unless it is due to format printing.
Since the counter 3 is reset to maintain the off state, the counter 3 continues to count the drive pulses 7 of the line feed step motor 10, and when a carry is generated from the counter 3, the output signal 6 is turned on and this is transmitted to the control section 4. However, when the output signal 5 of the paper end detection 'P11 is turned on due to format printing, when the format printing section passes the 7 sensor due to the feed feed operation, the paper end detector 1
The output signal 5 of is turned off again, the counter 3 is reset, and its output signal 6 is kept off, so that the paper end detection signal is not transmitted to the control section 4. By doing this, it is possible to prevent errors in paper end detection due to format printing or the like.

In this way, by using the drive pulse signal 7 of the line feed step motor 10 to turn on the paper end detection signal only when the paper end is detected continuously over a certain width, the paper 12 can be formatted. It is possible to prevent paper from reaching the end due to printing, etc., to prevent printing from stopping due to erroneous paper end detection, and to prevent erroneous paper end information from being sent to a host device.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a paper end detection signal is output only when paper end information indicating the paper end is continuously sent over a certain width, thereby achieving format printing. This has the effect of preventing errors in paper end detection caused by such factors, and preventing the printing operation from stopping and sending erroneous paper end information to the one-to-one stand-alone device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. Explanation of symbols of main parts 1... Paper end detector 2... Inverter 3... Counter 4... Control section 7... Drive pulse signal

Claims (1)

[Claims] A paper end detection method for a serial printer having a paper end detection means for detecting the end of paper, wherein paper end information indicating the end of the paper from the paper end detection means is continuous while the paper is fed by a predetermined amount. A paper end detection method is characterized in that a paper end detection signal is transmitted when a paper end detection signal is output.