JP4428132B2 - Continuous paper mark detection method, mark detection detection mechanism, and printer - Google Patents

Description

  The present invention relates to a mark detection method and a mark detection mechanism suitable for a printer that performs printing on continuous paper on which a mark such as a black mark representing a cutting position is printed. More specifically, a mark detection method and a mark detection mechanism that can prevent malfunction when an optical sensor for detecting a mark is contaminated by paper dust and the output is reduced, and a printer having the mark detection mechanism It is about.

As a printer that prints on continuous paper, the leading edge of the continuous paper after printing is cut in the width direction based on the black marks printed on the surface of the continuous paper at regular intervals along its length. What is issued as a receipt of a certain length is known. This type of printer is disclosed, for example, in Patent Document 1 below. As disclosed in this document, a light reflection type sensor is generally used as a sensor for detecting a black mark. The reflected light amount of the black mark is extremely small compared to the reflected light amount of the white background portion of the continuous paper surface. Therefore, the black mark can be detected based on whether or not the output of the light reflection type sensor is equal to or lower than a predetermined level (threshold).
JP 2002-62262 A

  Here, the continuous paper is generally provided as a roll body wound up in a roll shape. The roll body has a standard width by cutting a long roll body into a certain length. Therefore, paper dust generated at the time of cutting adheres to both ends of the roll body. For this reason, when printing is performed with the roll body mounted on the printer, the paper dust falls along the transport path. In addition, dust other than paper dust may adhere. If foreign matter such as paper dust adheres to the light emitting surface and light receiving surface of the optical sensor that detects the black mark placed on the transport path, the light emission amount or light receiving amount of the optical sensor decreases, and the output level accordingly. Also decreases. When the amount of adhered foreign matter increases, the output level is greatly reduced, and there is a possibility that the sensor output becomes below the threshold value even though the black mark has not passed. If the light reflection type sensor malfunctions, the continuous sheet cannot be cut at an appropriate cutting position.

  SUMMARY OF THE INVENTION An object of the present invention is to propose a mark detection method and a mark detection mechanism for continuous paper in a printer that can prevent malfunction of an optical sensor for detecting a mark such as a black mark.

  Another object of the present invention is to propose a printer that can prevent a malfunction in which continuous paper is cut at an inappropriate position due to erroneous mark detection.

In order to solve the above problem, the continuous paper mark detection method of the printer according to the present invention is printed on the surface of the continuous paper to be conveyed on the conveyance path for conveying the continuous paper via the printing position. An optical sensor for detecting a mark, and for detecting that the rear end of the continuous paper has passed the detection position by the optical sensor at a position downstream of the optical sensor on the transport path. With a paper presence sensor,
The initial output level of the optical sensor in said condition the continuous paper is not measured,
Based on the initial output level, a threshold value of an output level serving as a reference for detecting the mark is determined, the mark of the continuous paper transported along the transport path is detected based on the threshold value, and the paper presence sensor After it is detected that the trailing edge of the continuous paper has passed the detection position by the optical sensor, the output level of the optical sensor is measured again, and the measured output level is lower than the initial output level. In this case, the threshold value is reset based on the measurement output level.

  When foreign matter such as paper dust dropped from the conveyed continuous paper adheres to the light emitting surface or the light receiving surface of the optical sensor, the light emission amount or the light reception amount decreases, and the sensor output level decreases accordingly. In the present invention, every time there is no continuous paper, the output level of the optical sensor in the absence of continuous paper is measured again, and this is compared with the initial output level. I have confirmed. When the measurement output level is low, the detection reference threshold is lowered accordingly. This avoids erroneous mark detection.

  Here, when the measured output level is equal to or lower than the first level, or when the reset threshold is equal to or lower than the first value, it is desirable to output a predetermined warning. By outputting the warning, the printer user can know that maintenance such as cleaning of the optical sensor is necessary. By removing the foreign matter adhering to the maintenance, malfunction of the sensor can be avoided in advance.

Next, as the amount of foreign matter attached to the light emitting surface or light receiving surface of the optical sensor increases, the sensor output level also decreases, and the output level obtained when the white background portion of the continuous paper surface passes, and the mark The difference from the output level obtained when passing is gradually reduced. If the difference between the two output levels becomes narrow, the mark cannot be detected even if the threshold value is adjusted. Therefore, when the measured output level is less than or equal to the second level less than the first level , or when the reset threshold is less than or equal to the second value less than the first value. It is desirable to switch the subsequent printing operation to the disabled state and prevent malfunction.

  The method of the present invention is suitable for use for detecting a black mark for displaying each cutting position in the length direction on a continuous sheet.

On the other hand, the mark detection mechanism of the printer of the present invention is
An optical sensor for detecting a mark printed on the surface of the continuous paper transported through the transport path, arranged at a fixed position on the transport path for transporting the continuous paper via the printing position of the printer; ,
A paper presence sensor that is disposed at a position downstream of the optical sensor on the transport path and detects a rear end of the continuous paper transported along the transport path;
The output level of the optical sensor, as compared with the optical initial output level based preset by which the threshold of the sensor in the state continuous paper is not the mark passes the position detected by the optical sensor Determining means for determining whether or not
When the measured output level of the optical sensor measured when the trailing edge of the continuous sheet is detected by the paper presence sensor is lower than the initial output level, the threshold is reset based on the measured output level. And a threshold resetting means.

  Here, when the measurement output level becomes equal to or lower than the first level, or when the reset threshold value becomes equal to or lower than the first value, warning output means for outputting a predetermined warning is provided. It is desirable.

Further, when the measured output level is less than or equal to the second level less than the first level , or when the reset threshold is less than or equal to the second value less than the first value , It is desirable to have a forced stop means that disables the subsequent printing operation.

  Furthermore, when the optical sensor is a reflective optical sensor disposed below the transport path, the detection light emitted from the optical sensor is placed on the optical path above the transport path. A reflector that reflects toward the sensor may be disposed. The initial output level and the measured output level when there is no continuous paper can be measured based on the reflected light from the reflecting plate.

  Next, the present invention relates to a printer, and based on the determination result of the mark detection mechanism having the above-described configuration and the determination unit, the leading end print portion of the continuous sheet that has passed through the print position is cut in the width direction. And cutting means. Since erroneous detection of the mark can be prevented in advance, inappropriate cutting operation of the cutting means due to erroneous detection can be prevented beforehand.

  In the present invention, the end of continuous paper is detected using a paper presence sensor, and when the continuous paper ends, the output level of an optical sensor for detecting a mark on the continuous paper is measured, and this is output as an initial output. When the output level decreases compared to the level, the threshold for mark detection is reset according to the measured output level. Also, a warning is given that the output level has decreased. Accordingly, it is possible to prevent a malfunction caused by a foreign matter such as paper dust adhering to the mark detecting optical sensor and lowering the output level. Further, it is possible to prevent malfunction of the printer due to erroneous detection such as cutting continuous paper at an incorrect position based on the sensor output. Furthermore, since the operation of the printer is disabled when the output level of the optical sensor is significantly reduced, it is possible to prevent malfunction of the printer based on the inability to detect the mark.

  An example of a roll paper printer to which the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of the roll paper printer of this example. FIG. 2 is an explanatory diagram showing the relationship between black marks printed on continuous paper and each part of the printer. As shown in FIG. 1, a roll paper printer 1 includes a roll paper storage unit 4 for storing a roll paper 3 having a configuration in which a continuous paper 2 having a certain width is wound in a roll shape, and the roll paper loaded therein. 3 has a conveyance path 7 for guiding the continuous paper 2 fed out from 3 to the discharge port 6 via the printing position 5. A print head 8 and a platen 9 are opposed to each other at a print position 5 on the conveyance path 7 with a certain gap. The print head 8 is, for example, an ink pact dot head. Further, a light reflection type sensor 11 and a mechanical sensor 12 (paper presence sensor) are arranged in a conveyance path portion between the printing position 5 and the roll paper storage unit 4 in the conveyance path 7.

  As shown in FIG. 2, the continuous paper 2 is printed with rectangular black marks 2b at regular intervals in the length direction along one edge of the surface 2a. The black mark 2b is a mark for detecting the cutting position, and the black mark 2b is detected by the light reflection type sensor 11. The light reflection type sensor 11 is arranged on the lower side of the conveyance path in an upward state so as to face the surface 2a of the continuous paper 2 fed out from the roll paper supply unit 4. Above the light reflection type sensor 11, the reflection surface 13 a of the reflection plate 13 is disposed opposite to the conveyance path 7. When there is no continuous paper 2, the light emitted from the light emitting surface 11 a of the light reflecting sensor 11 is reflected by the reflecting surface 13 a and irradiates the light receiving surface 11 b of the light reflecting sensor 11.

  A mechanical sensor 12 is disposed at a position downstream of the conveyance path 7 with respect to the light reflection type sensor 11. The mechanical sensor 12 is a mechanical switch that includes a detection piece 12a that is inclined to the downstream side in the transport direction and is pressed against the surface 2a of the transported continuous paper 2 by an elastic force. When the trailing edge of the continuous paper 2 passes the detection piece 12a, the detection piece 12a turns upward as indicated by an imaginary line in the drawing, and it is detected that the trailing edge of the continuous paper 2 has passed. That is, it is detected that the continuous paper 4 has disappeared at the detection position of the light reflection type sensor 11 located on the upstream side.

  On the other hand, a paper feed roller 14 is disposed in the transport path 7 on the downstream side of the printing position 5, and a paper pressing roller 15 is pressed against the paper feed roller 14. The paper feed roller 14 is rotationally driven by a paper feed motor (not shown), and the paper pressing roller 15 rotates with the paper feed roller 14 to convey the continuous paper 2 sandwiched between them toward the discharge port 6. To do. An auto cutter 16 is disposed in the vicinity of the upstream side of the discharge port 6 in the transport path 7. As the auto cutter 16, a known type such as a pinching type or a rotary blade type can be used. At the cutting position by the auto cutter 16, the continuous paper 2 is cut in the width direction.

  In this example, as shown in FIG. 2, the cutting position 2c of the continuous paper 2 is an intermediate position in the length direction of each black mark 2b. Accordingly, the length from the black mark 2b to the cutting position 2c is set to be the conveyance path length from the detection position of the light reflection sensor 11 to the cutting position of the auto cutter 16.

  Next, each part of the roll paper printer 1 is driven and controlled by the drive control device 20. The drive control device 20 is composed mainly of a microcomputer, and includes a CPU, a ROM, and a RAM. By executing a control program stored in the ROM, printing is performed based on print information supplied from the host device 21. Printing is performed on the surface 2 a of the continuous paper 2 by the head 8. Further, the drive control device 20 compares the output level of the light reflection type sensor 11 with a preset threshold value, and determines whether or not the black mark 2b has passed the detection position by the light reflection type sensor 11. It functions as a discrimination means. Further, when the measurement output level of the light reflection sensor 11 measured when the rear end of the continuous paper 2 is detected by the mechanical sensor 12, the threshold value is reset based on the measurement output level. Functions as a threshold resetting means. Further, when the reset threshold value is equal to or lower than the first level, it functions as a warning output means for displaying a warning message indicating that maintenance is necessary on the screen of the printer display device 22. Furthermore, when the reset threshold value is equal to or lower than the second level (<first level), it functions as a forced stop means for disabling the subsequent printing operation.

  FIG. 3 is a schematic flowchart showing the printing operation of the roll paper printer 1. In the print standby state, the leading print position of the continuous paper 2 is located at the print position by the print head 8. When a print command is received from the host device 21 (step ST1), the paper feed roller 14 is driven to start transporting the continuous paper 2, and the print head 8 is driven at a predetermined timing so that the surface 2a of the continuous paper 2 is applied. Predetermined printing is performed (step ST2). After the series of printing operations is completed (step ST3), when the subsequent black mark 2b printed on the surface 2a of the continuous paper 2 is detected by the light reflection type sensor 11 (step ST4), the paper feed roller 14 is moved. The conveyance of the continuous paper 4 is temporarily stopped and stopped (step ST5). Thereafter, the auto cutter 16 is driven to cut and cut the leading end printing portion of the continuous paper 2 (step ST6). As a result, a print sheet such as a receipt having a predetermined length is discharged from the discharge port 6. Thereafter, the continuous paper 2 is reversely fed by a certain amount, and a cueing operation for adjusting the head print position of the continuous paper 2 to the print position by the print head 8 is performed (step ST7). After cueing, the printer waits for the next print command in that state.

  FIG. 4 is an explanatory view showing an output state of the light reflection type sensor 11. As shown in this figure, the upper limit value and the lower limit value of the output level of the light reflecting sensor 11 are set to 3.3 V and 0 V, respectively, for example. In the initial state, as indicated by the solid line A, when the white background portion on the front surface 2a of the continuous paper 2 is detected (between time t1 and t2 and from time t3 to t4), the reflecting plate 13 An output slightly lower than the output level S (0) due to the amount of light reflected from the reference reflection surface 13a is obtained. On the other hand, when the black mark 2b is detected, the amount of received light decreases, so that a low level output can be obtained as from time t2 to time t3.

  The drive control device 20 stores and holds the measured value of the output level of the light reflection type sensor 11 (the measured value of the amount of reflected light from the reference reflecting surface 13a) when there is no continuous paper 2 as the initial output level S (0). Has been. Further, an initial threshold value SH (0) serving as a reference for detecting the black mark 2b based on the output of the light reflection type sensor 11 is also set based on the initial output level S (0) and stored and held. For example, a value of 80% of the initial output level S (0) is set as the initial threshold value SH (0). When the output level S falls below the initial threshold value SH (0), the drive control device 20 determines that the black mark 2b has been detected.

  However, in the light reflection type sensor 11 in which the light emitting surface 11a and the light receiving surface 11b are positioned upward at the lower position of the continuous paper 2 being conveyed, the paper dust dropped from the continuous paper 2 is emitted from the light emitting surface 11a or the light receiving surface 11b. If accumulated, the output level decreases. For example, as indicated by a broken line A1 in FIG. 4, the output level as a whole decreases by Δ. As a result, the initial threshold value SH (0) is applied to the fluctuation range such as noise in the output level obtained from the white background portion of the continuous paper 2 at the lowered output level, and the black mark 2b may be erroneously detected. . Therefore, the drive control device 20 checks the output state of the light reflection type sensor 11 every time the continuous paper 2 runs out to prevent erroneous detection.

  That is, when the printing is repeated and the roll paper 3 is removed, the rear end of the continuous paper 2 passes through the light reflection type sensor 11 and the mechanical sensor 12. When the rear end of the continuous paper 2 passes the detection piece 12 a of the mechanical sensor 12, the detection piece 12 a turns and a detection signal is output to the drive control device 20. When the drive control device 20 detects that the continuous paper 2 is exhausted by this signal, the drive control device 20 activates an interrupt process for preventing erroneous mark detection of the light reflection type sensor 11.

  FIG. 5 is a schematic flowchart showing this interrupt processing. When the rear end of the continuous paper 2 is detected by the mechanical sensor 12, first, the output level of the light reflection type sensor 11 is measured. That is, the detection light is emitted from the light emitting surface 11a without the continuous paper 2 to irradiate the reference reflecting surface 13a of the reflecting plate 13, and the reflected light reflected by the reference reflecting surface 13a is received by the light receiving surface 11b. Is measured (step ST11, time point after time t5 in FIG. 4). Next, the obtained measured output level S (m) is compared with the initial output level S (0) (step ST12).

  If the measurement output level S (m) is lower than the initial output level S (0), the threshold is reset based on the measurement output level S (m) (step ST13). For example, when the measured output level S (m) is lower than the initial measured level S (0) by Δ as shown by the broken line A1 in FIG. 4, the measured output level is as shown by the alternate long and short dash line B1. A value of 80% of S (m) is set as a new threshold value SH (1).

  Here, when the amount of foreign matter adhering to the light reflection sensor 11 further increases, the output level also decreases accordingly. When the newly set threshold value SH (1) is lower than the first value α (step ST14), the drive control device 20 displays a warning message for prompting maintenance on the pretan display device 22 (step ST16). The warning may be a warning sound or a voice message from a speaker or the like instead of or together with the display.

  Next, when the output level of the light reflection type sensor 11 obtained from the white background portion of the continuous paper 2 is further lowered, even if the threshold level is lowered, the threshold level is applied to the normal output level fluctuation range, and normal black Mark detection is impossible. In this example, when the calculated threshold level SH (1) is equal to or lower than the second value β set in advance (step ST15), a message prompting maintenance is displayed on the display device 22 and forced. Therefore, the subsequent printer operation is disabled (step ST17). Accordingly, it is possible to prevent the adverse effect that the continuous paper 2 stops being conveyed due to erroneous detection of the black mark 2b and the continuous paper 2 is cut at an inappropriate position by the auto cutter 16.

  In this example, although the light reflection type sensor 11 is used as the black mark detection sensor, a light transmission type optical sensor may be used.

  Further, the example in which the optical sensor is disposed on the lower side of the transport path has been described, but the optical sensor may be disposed on the upper side of the transport path. On the side, a reflecting plate that reflects detection light emitted from the optical sensor toward the optical sensor may be disposed.

  Furthermore, a cutter blade for manual cutting may be disposed in the vicinity of the upstream side of the discharge port without disposing the auto cutter.

  Furthermore, in this example, the paper presence sensor is detected using a mechanical sensor that is not affected by the adhesion of paper dust, etc., so it can be reliably detected that there is no continuous paper, and the output level can be reliably measured. Therefore, the optical sensor has an effect that the foreign matter adhesion state of the optical sensor can be surely known at every end of the continuous paper, but the light transmission type optical type having a large difference in output level. Sensors can also be used.

  On the other hand, although the threshold value is described as 80% in this example, it goes without saying that the threshold is optimized according to the sensor.

1 is a schematic configuration diagram illustrating a roll paper printer to which the present invention is applied. FIG. 6 is an explanatory diagram illustrating a positional relationship between the position of a black mark on continuous paper and each part of a printer. 4 is a schematic flowchart illustrating a printing operation of a roll paper printer. It is explanatory drawing which shows the output state of a light reflection type sensor. 6 is a schematic flowchart illustrating interrupt processing of a roll paper printer.

Explanation of symbols

1 roll paper printer, 2 continuous paper, 2a surface, 2b black mark, 2c cutting position, 5 printing position, 7 transport path, 8 print head, 11 light reflection type sensor, 11a light emitting surface, 11b light receiving surface, 12 mechanical sensor, 13 reflecting plate, 13a reference reflecting surface, 14 paper feed roller, 16 auto cutter, 20 drive control device, 21 host device, 22 display device, S (0) initial output level, S (m) measurement output level, SH (0 ) Initial threshold, SH (1) Reset threshold, α first value, β second value

Claims (9)

An optical sensor for detecting a mark printed on the surface of the continuous paper to be transported on a transport path for transporting the continuous paper via the printing position, and on the transport path more than the optical sensor. A paper presence / absence sensor for detecting that the rear end of the continuous paper has passed the detection position by the optical sensor at a downstream position ;
The initial output level of the optical sensor in said condition the continuous paper is not measured,
Based on the initial output level, a threshold value of the output level serving as a reference for detecting the mark is determined,
Detecting the mark of the continuous paper transported along the transport path based on the threshold;
After the paper presence sensor detects that the trailing edge of the continuous paper has passed the detection position by the optical sensor, the output level of the optical sensor is measured again.
A method for detecting a mark on a continuous sheet of a printer, wherein if the measured output level is lower than the initial output level, the threshold is reset based on the measured output level. In claim 1,
A predetermined warning is output when the measured output level is equal to or lower than the first level or when the reset threshold is equal to or lower than the first value. Method. In claim 2,
When the measured output level is less than or equal to the second level less than the first level , or when the reset threshold is less than or equal to the second value less than the first value , the subsequent printing operation is performed. A method for detecting a mark on a continuous sheet of a printer, wherein the mark is switched to a disabled state. In claim 1, 2 or 3,
The mark detection method for a continuous sheet of a printer, wherein the mark is for displaying each cutting position in the length direction of the continuous sheet. An optical sensor for detecting a mark printed on the surface of the continuous paper transported through the transport path, arranged at a fixed position on the transport path for transporting the continuous paper via the printing position of the printer; ,
A paper presence sensor that is disposed at a position downstream of the optical sensor on the transport path and detects a rear end of the continuous paper transported along the transport path;
The output level of the optical sensor, as compared with the optical initial output level based preset by which the threshold of the sensor in the state continuous paper is not the mark passes the position detected by the optical sensor Determining means for determining whether or not
When the measured output level of the optical sensor measured when the trailing edge of the continuous sheet is detected by the paper presence sensor is lower than the initial output level, the threshold is reset based on the measured output level. A mark detection mechanism for a printer having threshold resetting means. In claim 5,
A printer having a warning output means for outputting a predetermined warning when the measured output level is equal to or lower than a first level or when the reset threshold is equal to or lower than a first value. Mark detection mechanism. In claim 6,
When the measured output level is less than or equal to the second level less than the first level , or when the reset threshold is less than or equal to the second level less than the first value , the subsequent printing operation is disabled. A mark detection mechanism for a printer, characterized by comprising forced stop means. In any one of claims 5 to 7,
The optical sensor is a reflective optical sensor disposed below the transport path,
A mark detection mechanism for a printer, wherein a reflection plate that reflects detection light emitted from the optical sensor toward the optical sensor is disposed above the transport path. A mark detection mechanism according to any one of claims 5 to 8,
A printer comprising: cutting means for cutting in a width direction a leading end print portion of the continuous paper that has passed through the print position based on a determination result of the determination means.

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