JP2006248097A - Line-misalignment detecting method for dot-line printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stop a printing action in the detection of line misalignment by detecting the line misalignment through the use of an inexpensive component without a drastic change of a paper feed mechanism. <P>SOLUTION: A plurality of reflection host sensors for detecting the passage of printing paper through a feed hole are provided at arbitrary intervals, and the detection of the line misalignment is realized by comparing the number of times when the reflection host sensors detects a feed hole during line feed, with the reference number of times of the detection of the feed hole, which is preset for each line feed amount. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a line shift detection method for a dot line printer.

  FIG. 5 shows an outline of the printing mechanism of the dot line printer.

  The hammer mechanism 51 having a printing element reciprocates in the digit direction (direction orthogonal to the paper feed direction) by a shuttle mechanism (not shown). Further, the hammer mechanism 51 is disposed in a state of facing the platen 54 for ensuring the printing force via the ink ribbon 52 and the printing paper 53. Each time the printing element is driven in a timely manner in a reciprocating motion, characters, figures, etc. are printed on the printing paper 53 in the form of a dot matrix.

  The tractor L55 and the tractor R56 serve to convey the printing paper 53 by engaging pins with feed holes continuously arranged at both ends of the printing paper 53. The printing paper 53 is fed in the row direction (paper feeding direction) by the paper feeding mechanism 57 and the paper feeding motor 58 in which the tractor L55 and the tractor R56 are arranged at an appropriate time during the reciprocating motion of the hammer mechanism 51.

  A reflection type photosensor (hereinafter referred to as reflection type photosensor A) 59 for detecting the passage of the paper feed hole is provided at the upper portion of the tractor L55. It monitors whether there is a paper running failure due to cutting.

  In general, a stepping motor is used as the paper feed motor 58 of the dot printer, and the printing paper 53 is set so as to be conveyed by an amount corresponding to one dot of the printing element every time one step is driven.

  In the conventional technology, in the control of the paper feed motor, the stepping motor rotates at a predetermined step angle in synchronization with the drive pulse, so that the operation of the motor is not constantly monitored by an encoder or a tachometer, so-called open loop control Thus, speed and positioning are performed, thereby simplifying the device configuration and reducing costs.

  However, the paper feed motor 58 rotates at a high speed when the amount of line feed is large, but when it rotates at a high speed, the torque generally decreases due to the characteristics of the motor. At this time, if tension is applied to the printing paper 53 due to load fluctuation, the paper feed motor 58 may step out for a moment, but the above-described open loop control cannot detect step out.

  As described above, even if a step-out is not detected and a line shift occurs, the dot line printer continues the printing operation. As a result, it is noticed that there is a line shift after the end of printing, and particularly in the case of continuous printing of a large number of sheets, it takes a lot of time and cost for reprinting and the like.

  In addition, encoders, tachometer generators, etc. can be provided to detect line shifts due to step-out by constantly monitoring the motor step amount. However, there are mounting problems and the encoder and tachometer generators themselves are expensive. The cost will increase significantly due to the addition of control.

  Accordingly, an object of the present invention is to detect a line shift using inexpensive parts without making a significant change in the paper feed mechanism, and to stop the printing operation when a line shift is detected.

  In order to solve the above-described problems, the present invention includes a hammer mechanism portion on which a plurality of printing elements are mounted, a shuttle mechanism for reciprocating the hammer mechanism portion in the girder direction, and feed holes that are continuously arranged at both ends. A dot line using a dot printer having a paper feed motor for applying power to rotate a tractor driving shaft for holding and driving a tractor for holding the tractor and a tractor for conveying the printing paper by engaging a continuous form printing paper and a tractor A method of detecting a line deviation of a printer, wherein a plurality of reflective photosensors for detecting passage of a feed hole are provided in a tractor at an arbitrary interval, and the number of times the reflective photosensor detects a feed hole at the time of a line feed and the amount of line feed It is characterized in that the presence / absence of a line shift is detected by comparing a reference detection number of a feed hole set in advance for each of the above.

  The present invention prevents line-shift printing and, as a result, prevents the use of a computer system and the cost of printing paper associated with checking and reprinting of printing results from becoming large.

  The present invention has been realized by arranging an inexpensive reflective photosensor on the left and right tractors without significantly changing the paper feed mechanism.

  An embodiment of the present invention will be described with reference to FIGS. The following description will be made using a dot line printer having a print density in the row direction of 180 dpi.

  FIG. 1 is a diagram showing the arrangement of a reflective photosensor. The interval between the feed holes of the printing paper 53 is defined as 1/2 inch (equivalent to 90 dots). A reflective photosensor A59 is provided above the tractor L55 through which the feed holes pass, and a reflective photosensor B11 and a reflective photosensor C12 are provided above the tractor R56 through which the feed holes pass. The reflective photosensor B11 is shifted 1/6 inch upward (corresponding to 30 dots) with respect to the reflective photosensor A59, and the reflective photosensor C12 is shifted downward 1/6 inch with respect to the reflective photosensor A59. Deploy. In this way, by arranging three reflective photosensors that detect feed holes at intervals of 30 dots with respect to 90 dots of feed hole intervals, one of the reflective photosensors is fed every 30 dot line feed amount. Is detected.

  Usually, the line shift that occurs at the time of a line feed is shifted by an amount of 30 dots or more. Therefore, when a line deviation occurs, the total number of times that the reflection type photosensor A59, the reflection type photosensor B11, and the reflection type photosensor C12 detect the feed hole is one or more times less than when no line deviation occurs.

  As an example, FIG. 2 is a diagram showing an operation of counting the number of detections of feed holes when the line feed amount is 240 dots and the sensor that detects the feed holes first is the reflective photosensor C12. When a line feed is started by a line feed command from a paper feed control unit (not shown) and the reflection type photosensor C12 detects the feed hole A21, the signal of the reflection type photosensor C12 changes from L (Low) to H (High). stand up. With the rise of this signal, a counter (hereinafter referred to as a counter) in the paper feed control unit is increased from 0 to 1.

  Next, when the printing paper 53 is fed by 1/6 inch and the reflective photosensor A59 detects the feed hole B22, the signal of the reflective photosensor A59 rises from L to H. The counter is incremented to 2 by the rise of this signal.

  Next, when the printing paper 53 is fed by 1/6 inch and the reflection type photosensor B11 detects the feed hole A21, the signal of the reflection type photosensor B11 rises from L to H. The counter is increased to 3 by the rise of this signal.

  This is sequentially repeated. Finally, the feed hole C23 is detected by the reflection type photosensor A59, and the counter value becomes 8.

  FIG. 3 is a flowchart of line shift detection. FIG. 4 shows the number of times of reference detection of the feed hole set in advance for each line feed amount.

  In FIG. 3, when the line feed amount (number of steps of the paper feed motor) is received from the host device in process 301, the counter is cleared to 0 in process 302, and the paper feed motor is driven in process 303 to start a line feed. When 1 dot (paper feed motor 1 step) printing paper is sent in process 304, the signal from reflection type photosensor A59, reflection type photosensor B11, or reflection type photosensor C12 is detected as L by detection of the feed hole in process 305. Check if there was a rise from H to H. Here, if there is a rise from L to H, the counter is incremented by 1 in step 306, and if there is no rise from L to H, the counter is not incremented.

  Next, it is confirmed in process 307 whether or not the line feed amount of printing paper received in process 301 has been completed. If it has not been completed, process 304 to process 307 are repeated, and if completed, the paper feed motor is turned on in process 308. Stop and move to processing 309.

  In process 309, it is determined whether or not the line feed amount received in process 301 is equal to or greater than 30 dots (reflection photosensor installation interval). If the line feed amount is less than 30 dots, it is considered that there is no line shift and process 312 is performed. Ends line feed processing with.

  When the line feed amount is 30 dots or more in the process 309, the reference detection number of the feed hole preset for each line feed amount shown in FIG. 4 is calculated in the process 310, and the counter value is calculated in the process 310 in the process 310. If it is the reference number of detections, the paper feed process is terminated in step 312. If it is not the reference number of detections, the printing operation is stopped in step 313, and an operation panel (not shown) is displayed. “Paper running error” is displayed on the display (for example, LCD).

  In this embodiment, one reflection type photosensor is installed on the left tractor and two on the right tractor. However, two reflection photosensors may be installed on the left tractor and one on the left tractor.

It is the figure which showed arrangement | positioning of a reflection type photosensor. It is the figure which showed the operation | movement which counts the frequency | count of detection of a feed hole. It is a flowchart of line shift detection. This is the reference detection number of feed holes set in advance for each line feed amount. It is the schematic of the printing mechanism of a dot line printer.

Explanation of symbols

11 is a reflection type photosensor B, 12 is a reflection type photosensor C, 21 is a feed hole A, 22 is a feed hole B, 23 is a feed hole C, 51 is a hammer mechanism, 52 is an ink ribbon, 53 is printing paper, 54 is a platen, 55 is a tractor L, 56 is a tractor R, 57 is a paper feed mechanism, 58 is a paper feed motor, and 59 is a reflection type photosensor A.

Claims (1)

Engage the hammer mechanism with multiple printing elements, the shuttle mechanism for reciprocating the hammer mechanism in the digit direction, and the continuous form printing paper and feed tractor with feed holes arranged continuously at both ends. A line shift detection method for a dot line printer using a dot printer having a tractor that conveys printing paper, a tractor drive shaft that holds and drives the tractor, and a paper feed motor that provides power to rotate the tractor drive shaft,
A plurality of reflective photosensors that detect the passage of feed holes are provided on the tractor at arbitrary intervals, and the number of times the reflective photosensor detects a feed hole at the time of a line feed, and a reference for a feed hole set in advance for each line feed amount. A method of detecting a line shift of a dot line printer, wherein the presence or absence of a line shift is detected by comparing the number of detections.

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