JP5419205B2 - Label detection device - Google Patents

Description

  The present invention relates to a label detection apparatus for detecting a label mark in a process in which a long sheet is conveyed on a conveyance path at a predetermined speed.

While the long paper is being transported on the transport path at a specified speed, the label position of the paper is detected and the label position is detected accurately, and the label is printed or a label is attached based on the detected label position. Label detecting devices for attaching are known.
The label mark of the paper indicates a mark (gap) between the labels of the paper on which a plurality of labels are temporarily attached at a predetermined interval so as to be peeled off on one side of a long mount, or a pre-printed label position. There are label marks such as position detection marks (so-called black marks).
Such a label detection apparatus is provided with a sensor for detecting a label mark on the paper. In general, a sensor has a light emitting element and a light receiving element at positions facing the front and back sides of a sheet, and detects a mark (gap) between labels based on a difference in transmitted light amount transmitted through the conveyed sheet. Sensor or a reflection sensor that has a light emitting element and a light receiving element on one side of the paper, emits light to the position detection mark of the conveyed paper, and detects the position detection mark by the difference in the amount of reflected light reflected There is.

When a transmission sensor is used in a conventional label detection device, a threshold value for a change in output level of the transmission sensor detected by paper conveyance is calculated and set in advance, and the transmission sensor output value is compared with the threshold value while paper is being conveyed. Thus, the print position is determined by detecting the label mark (for example, Patent Document 1).
In addition, when a reflection sensor is used, the position detection mark of the conveyed paper is compared with the reflection sensor output value and the threshold value, the length of the position detection mark is measured, and the midpoint of the position detection mark is determined. A technique for calculating and determining a printing position is known (for example, Patent Document 2).

Japanese Patent Laid-Open No. 02-139329 JP 05-147310 A

FIG. 9 is a diagram showing a label detection method using a conventional transmission sensor. In the conventional label detection method using the transmission sensor, the leading edge of the label 22b is detected by comparing the sensor output waveform Ha of the transmission sensor with the threshold T while conveying the paper 20.
In the conventional method shown in FIG. 9, when the paper 20 is replaced with a different production lot, when the temperature around the transmission sensor changes, or when paper dust or the like adheres to the vicinity of the transmission sensor, The amount of transmitted light of the mount 23 between the labels 22b changes. Specifically, the output value of the transmission sensor changes from the sensor output waveform Ha to the sensor output waveform Hb. Occurs, and the printing position on the label 22b is shifted. Therefore, there is a problem that work such as resetting the threshold value again or readjusting the sensor output level is required, and the work becomes complicated.

FIG. 10 is a diagram showing a conventional label detection method using a transmission sensor, and a label 25 in FIG.
In the conventional method shown in FIG. 10, the amount of transmitted light at the leading portion of the label 22b is changed by the printing unit 25, and the output value of the transmission sensor changes from the sensor output waveform Ha to the sensor output waveform Hb. If the determination is made, a label detection position shift G occurs, and the print position on the label 22b shifts. For this reason, when the paper having the printing unit 25 is replaced with the paper without the printing unit 25, the label detection position deviation G occurs, and the printing position on the label 22b is shifted. There is a problem that it is not possible to cope with a sheet in which a label having the printing unit 25 and a label having no printing unit 25 are mixed.

FIG. 11 is a diagram illustrating a label detection method using a conventional reflection sensor. The conventional label detection method using a reflection sensor compares the sensor output waveform Ha of the reflection sensor with a threshold T while conveying the marked sheet 21 on which the position detection mark 24 indicating the label position is printed, and the rear end of the label 22a. The rear end of the position detection mark 24 indicating is detected.
In the conventional method shown in FIG. 11, when the mount 23 that easily transmits light is replaced with the marked sheet 21, the reflected light amount differs between the mounts 23 between the labels 22 a and 22 b, and the output value of the reflection sensor is different. If the sensor output waveform Ha is changed to the sensor output waveform Hb and judged by a fixed threshold T, a label detection position shift G occurs, and the print position on the label 22b shifts. Therefore, there is a problem that work such as resetting the threshold value again or readjusting the sensor output level is required, and the work becomes complicated.

  The present invention has been considered in view of the above problems. Label detection that reliably detects a label mark on a paper even if the amount of transmitted light or reflected light on the paper changes depending on the type of paper or the presence or absence of label printing. It is an object to provide an apparatus.

  Further, the present invention provides a label detection device that detects a label mark on a sheet by changing a difference between sensor values at two successive positions of sensor output for each step drive by a conveying unit without providing a threshold for comparison with an output value of the sensor. The issue is to provide.

That is, the label detection apparatus according to claim 1 includes a transport unit that transports a sheet having a label mark, a detection unit that detects a sensor value of the label mark of the sheet transported by the transport unit, and the transport unit. A storage means for storing the sensor value detected by the detection means for each step drive, and a sensor value detected by the detection means in the previous step drive of the transport means and stored by the storage means and detected by the detection means The label mark measurement start determining means for determining the difference between the current sensor values and determining the start of label mark measurement, and the label mark measurement start determining means determining that the label mark measurement has started, and then stepping the previous transport means. in Raberuma determines the difference between the current sensor value detected by the sensor value stored in the storing means and the detection means detects said detection means It is the intermediate position or the determining label mark determination means the end position, and configurations with.
The label detection apparatus according to claim 2 is a conveyance unit that conveys a sheet having a label mark, a detection unit that detects a sensor value of a label mark of the sheet conveyed by the conveyance unit, and the detection unit. A detection value calculation unit that calculates the sensor value detected in step 1 to obtain a detection value; and a detection value calculation unit that calculates a detection value from the sensor value detected by the detection unit for each step drive of the transport unit; Storage means for storing the detection value, and label mark measurement for determining the start of label mark measurement by obtaining a difference between the detection value stored by the storage means and the detection value detected by the detection means and calculated by the detection value calculation means After the start determination means and the label mark measurement start determination means determine that label mark measurement starts, the detection value stored by the storage means and the detection value detected by the detection means are calculated. It has a configuration that includes a label mark determination means for determining the intermediate position, or end position of the label marks obtains the difference between the detection value calculated in unit.
According to a third aspect of the present invention, there is provided a label detection apparatus comprising an input unit for setting initial values of the label mark measurement start determination unit and the label mark determination unit.

As described above, according to the present invention, it is not necessary to set a threshold value for detecting a label mark, and an output value (sensor value) of a sensor for each step by the transport unit is measured, and sensor values at two consecutive positions are measured. The label mark is reliably detected by the change in the difference, and the leading position of the label can be accurately obtained from the detected label mark even if the transmitted light quantity or reflected light quantity of the paper changes depending on the type of paper or whether the label is printed. As a result, printing can be performed at an accurate printing position.
Furthermore, since a threshold value for detecting the label mark is not required, complicated operations such as resetting the threshold value again or readjusting the sensor output level are reduced.

  Next, a label detection apparatus that detects a middle point of a label mark using a transmission sensor according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5 and FIG.

FIG. 1 is a diagram illustrating a configuration of a label detection apparatus 100 according to an embodiment of the present invention.
The label detection apparatus 100 includes a transport unit 10, a detection unit 30, a control unit 40, a storage unit 50, a label mark measurement start determination unit 51, and a label mark determination unit 52. The sheet mark 20 is detected by the detection unit 30 while the sheet 20 is conveyed on the conveyance path at a predetermined speed by the conveyance unit 10, and the voltage of the label mark detected by the detection unit 30 is a digital value. The sensor value converted into is stored in the storage unit 50, and the label mark measurement start determination unit 51 and the label mark determination unit 52 determine the label mark.

FIG. 2 is a diagram showing the form of the paper used in this embodiment, FIG. 2 (a) is a figure showing the form of the paper used in the transmission sensor, and FIG. 2 (b) is used in the reflection sensor. It is a figure which shows the form of the paper to perform.
In the following embodiments of the present invention, description will be made using the paper 20 of FIG.

FIG. 3 is a block diagram of a control unit in the label detection apparatus of this embodiment.
In the block diagram showing the control unit of the label detection device 100, the control unit 40 of the label detection device 100 operates as a CPU 41 that controls each unit, a ROM 42 that stores a predetermined control program for the CPU 41 to control, and the CPU 41 operates. A RAM 43 for storing various data necessary for the above, a pulse signal for supplying a step drive to the transport motor 12, a motor control unit 11 for controlling the transport of the paper 20 by rotating the platen roller 13 by the transport motor 12, and a CPU 41 A control signal corresponding to print data such as characters and figures to be printed supplied from the printer is generated and supplied to the print head 15 to emit light toward the paper 20 and a print control unit 14 for performing a print operation. In addition, the voltage converted into a predetermined voltage according to the amount of light received by the sensor light receiving element is converted into a digital value. And supplies A / D circuit 37 to capacitors values to CPU 41, an operation unit 44 that performs key input and LCD display, an external I / F unit 45 that communicates to connect to external devices such as a host computer.
Each of these units is connected to the CPU 41 via a data bus, and under the control of the CPU 41, the label mark is detected by the detection means 30 while the sheet 20 is conveyed on the conveyance path at a predetermined speed.

  The conveyance means 10 supplies a pulse signal to the conveyance motor 12 under the control of the CPU 41 and controls the conveyance motor 12 by step driving, the conveyance motor 12 of the motor that rotates under the control of the motor control unit 11, A platen roller 13 that rotates by the rotation of the transport motor 12 is provided. The paper 20 is sandwiched between the print head 15 that prints on the label 22 by the heat generation and the platen roller 13, and the paper 20 is transported by the rotation of the platen roller 13.

The detection unit 30 includes a transmission sensor 31 that detects the amount of light transmitted through the paper 20, and an A / D circuit 37 that converts the voltage output from the transmission sensor 31 into a digital value and sends the converted digital value to the CPU 41. Prepare.
The transmission sensor 31 is provided on the upstream side of the transport unit 10, and is provided at a transmission sensor light emitting element 32 provided on one side of the paper 20 and the other position facing the transmission sensor light emitting element 32 across the paper 20. The transmitted light amount of the sheet 20 conveyed by the conveying means 10 is measured by the transmission sensor light receiving element 33. In this case, the transmission sensor 31 may be a transmission sensor having a wide viewing angle. Next, the transmission sensor 31 outputs a predetermined voltage to the A / D circuit 37 according to the amount of transmitted light received, and the A / D circuit 37 sends a sensor value obtained by converting the input predetermined voltage into a digital value to the CPU 41. .

FIG. 4 is a diagram illustrating a circuit of the transmission sensor.
The transmission sensor light emitting element 32 is provided on one surface of the paper 20 and emits light at all times or when the paper 20 is transported.
The transmissive sensor light receiving element 33 is provided on the other side of the paper 20 of the transmissive sensor light emitting element 32, emits light from the transmissive sensor light emitting element 32, and passes through the mount 22 and the label 22 temporarily attached to the mount 23. Is converted into a predetermined voltage according to the amount of received light.
The A / D circuit 37 converts the voltage converted by the transmission sensor light receiving element 33 into a digital value, and outputs the converted digital value as a sensor value to the CPU 41.

Hereinafter, in the label detection apparatus of the present invention, the operation until the detection means 30 detects the middle point of the label mark with the transmission sensor 31 will be described with reference to FIGS.
5A and 5B are diagrams for explaining the difference between the sensor output waveform detected by the transmission sensor and the detected value at the two positions. FIG. 5A shows the form of the paper, FIG. 5B shows the transmission sensor output waveform, and FIG. FIG. 5C is an explanatory diagram for explaining the difference between the detected values at the two positions obtained from the output waveform of the transmission sensor. FIG. 8 is a flowchart for explaining the operation for detecting the label mark by the detecting means 30.

First, in order to detect an intermediate point between the label 22a and the label 22b shown in FIG. 5, a label mark measurement start value 70a for determining a change point Pa that is an intermediate point between the labels is prepared in advance.
For example, when the A / D circuit 37 in which the digital output value of the A / D circuit 37 that detects the output voltage of the transmission sensor 31 changes in the range of “0 to 255” is used, the detection values of the two positions of the transmission sensor 31 are detected. The difference between the detected values at the two positions of the transmission sensor 31 when only the label is detected changes within the range of “−3 to +3”. In this case, a label mark measurement start value 70a for starting measurement of a mark (gap) between labels is set to “10 or more”, and a label mark determination for determining a change point Pa that is an intermediate point between labels. The value is “0 or less”. Further, using the sensor value input from the A / D circuit 37 by the detection means 30 with the value of the transmission sensor 31, each area of the previous detection value, maximum value, and minimum value provided in the RAM 43 is initialized (S1). .

Next, the one-step paper 20 is conveyed by the conveying means 10 (S2).
As the paper 20 is transported, the detection means 30 inputs the sensor value of the transmission sensor 31 from the A / D circuit 37 (S3).
The input sensor value is compared with the maximum value stored in the RAM 43. If the input sensor value is large, the input sensor value is stored in the RAM 43 as the maximum value. Further, the input sensor value is compared with the minimum value stored in the RAM 43. If the input sensor value is small, the input sensor value is stored in the RAM 43 as the minimum value (S4).
Using the maximum value and the minimum value, the ratio (percentage) of the input sensor value is calculated by the following calculation formula and used as the current detection value (S5) (detection value calculation means).
Detection value this time = (input sensor value-minimum value) / (maximum value-minimum value) x 100
The difference between the previous detection value stored in the RAM 43 and the current detection value calculated above is obtained (S6). This is to obtain the difference between the detected value of the position of the sheet 20 before being conveyed by the conveying means 10 and the detected value of the position of the sheet 20 conveyed by one step, that is, the difference between the detected values at two positions. 5 (b) detects a change in waveform.
The current detection value obtained in S5 is stored in the RAM 43 as the previous detection value (S7) (storage means 50).

If it is determined that the difference between the detected values at the two positions is less than the label mark measurement start value 70a (for example, less than 10), the process proceeds to S2 (S8) (label mark measurement start determination means 51). This process indicates that the sensor value has not been changed by the transmission sensor 31. Specifically, the paper 20 in FIG. 5A transports the paper step by step by the transport means 10 and detects it. It shows that the transmission sensor 31 detects a position where the label 22a and the mount 23 are located in the process of being sequentially detected in the direction of the arrow J1 by the means 30.
Therefore, in steps S2 to S8, the mount 23 is detected by the transmission sensor 31 while the paper 20 is being conveyed, and the label mark measurement start determination is performed in step S8. The processing from S2 to S8 is processing for detecting the J1 portion in the graph of FIG.

  If it is determined in S8 that the difference between the detected values at the current two positions is greater than or equal to the label mark measurement start value 70a (for example, 10 or greater), the process proceeds to S9. This processing indicates that there is a change in sensor value by the transmission sensor 31. Specifically, the sheet 20 in FIG. 5A conveys the sheet step by step by the conveying unit 10, and the detecting unit 30 In the process of sequentially detecting in the direction of the arrow J1, the transmission sensor 31 detects the position of the mount 23, and in the waveform diagram of FIG.

Next, in step S <b> 9, the one-step paper 20 is transported by the transport unit 10.
As the paper 20 is transported, the detection unit 30 inputs the sensor value of the transmission sensor 31 from the A / D circuit 37 (S10).
The input sensor value is compared with the maximum value stored in the RAM 43. If the input sensor value is large, the input sensor value is stored in the RAM 43 as the maximum value. Further, the input sensor value is compared with the minimum value stored in the RAM 43. If the input sensor value is small, the input sensor value is stored in the RAM 43 as the minimum value (S11).
Using the maximum value and the minimum value, the ratio (percentage) of the input sensor value is calculated by the following calculation formula and used as the current detection value (S12) (detection value calculation means).
Detection value this time = (input sensor value-minimum value) / (maximum value-minimum value) x 100
The difference between the previous detection value stored in the RAM 43 and the current detection value calculated above is obtained (S13).
The current detection value obtained in S12 is stored in the RAM 43 as the previous detection value (S14) (storage means 50).

If the difference between the detected values at the two positions is not the label mark determination value (for example, 0 or less), the process returns to S9 (S15) (label mark determination means 52). This processing indicates that the sensor value change by the transmission sensor 31 does not pass through the apex. Specifically, the paper 20 in FIG. 5A transports the paper step by step by the transport means 10. In the process of being sequentially detected by the detection means 30 in the direction of the arrow J2, it is shown that the transmission sensor 31 detects a position that is not the intermediate point (vertex) of the mount 23 in the waveform diagram of FIG. .
In S15, when the difference between the detected values at the two positions this time is a label mark determination value (for example, 0 or less), it indicates that the change point Pa has been passed. Specifically, it is determined that the vertex in the waveform diagram of FIG. 5B has been passed, and the process proceeds to S16 (S15) (label mark determination means 52).
An intermediate point of the mount 23 is obtained, and the position transported by a fixed distance from the position is set as the leading position of the label 22, so that the process of printing at the leading position of the label 22 is performed, and the process returns to S2 (S16).
Accordingly, in steps S9 to S15, the intermediate point of the mount 23 is detected by the transmission sensor 31 while the paper 20 is being conveyed, and it is determined whether or not the change point Pa is in step S15. The processing from S9 to S15 is processing for detecting the J2 portion in the graph of FIG.

According to the embodiment described above, the sensor value of the transmission sensor 31 is input from the A / D circuit 37, and the change in the difference between the two positions of the sensor value, that is, the inclination of the change in the sensor value is monitored. Since the change of the sensor value from the label 22a and the mount 23 to the mount 23 only can be recognized, it is not necessary to set a threshold value, and the middle point of the label mark can be detected.
Therefore, in the above embodiment, in the process of moving from the position where the label 22 and the mount 23 are located to the position of the mount 23 alone, the waveform of the sensor value input by the transmission sensor 31 is inclined downward (FIG. 5B). )), The intermediate point of the mount 23 is obtained, and the position transported by a fixed distance from the position is set as the leading position of the label 22 so that printing can be performed at the leading position of the label 22.

  Further, since the label mark can be detected without using the threshold value, the label cannot be detected even if the output value of the transmission sensor or the reflection sensor deviates from the threshold value, and the interval between the labels temporarily attached on the mount is not increased. If it is narrow, it is possible to detect the intermediate point of the mark (gap) position between the labels by using a low-cost transmission sensor with a wide viewing angle.

  In the label detection apparatus of the present invention, the operation until the detection means 30 detects the leading position of the label by the transmission sensor 31 will be described with reference to FIGS.

First, in order to detect the leading end of the label 22b shown in FIG. 5, a label mark measurement start value 70b for determining the change point Pb that is the leading position of the label is prepared in advance.
For example, the label mark measurement start value 70b for starting the measurement of the tip of the label 22b is set to “−10 or less”, and the label mark determination value for determining the change point Pb that is the tip of the label 22b is set. “-3 or more”. Further, using the sensor value input from the A / D circuit 37 by the detection means 30 with the value of the transmission sensor 31, each area of the previous detection value, maximum value, and minimum value provided in the RAM 43 is initialized (S1). .

  Next, the one-step paper 20 is conveyed by the conveying means 10 (S2), the sensor value of the transmission sensor 31 is input from the A / D circuit 37 by the detecting means 30 (S3), and the input sensor value, maximum value and minimum value are input. And the maximum value and the minimum value are stored in the RAM 43 (S4), and the ratio (percentage) of the input sensor value is calculated using the maximum value and the minimum value as the detected value this time (S5) (detected value) (Calculation means) The difference between the previous detection value stored in the RAM 43 and the current detection value calculated above is obtained (S6), and the current detection value is stored in the RAM 43 as the previous detection value (S7).

When it is determined that the difference between the detected values at the two positions is not less than or equal to the label mark measurement start value 70b (for example, not less than −10), the process proceeds to S2 (S8) (label mark measurement start determination means 51). . This processing indicates that the vicinity of the leading end of the label is not detected by the transmission sensor 31. Specifically, the sheet 20 in FIG. 5A conveys the sheet step by step by the conveying unit 10 and is detected by the detecting unit 30. It shows that the transmission sensor 31 detects the vicinity of the intermediate point of the mount 23 from the position where the label 22a and the mount 23 exist in the process of sequentially detecting in the direction of the arrow J3.
Therefore, in steps S2 to S8, the mount 23 is detected by the transmission sensor 31 while the paper 20 is being conveyed, and the label mark measurement start determination is performed in step S8. The processing from S2 to S8 is processing for detecting the J3 portion in the graph of FIG.

  If it is determined in S8 that the difference between the detected values at the current two positions is equal to or less than the label mark measurement start value 70b (for example, −10 or less), the process proceeds to S9. This process indicates that the vicinity of the leading edge of the label is detected by the transmission sensor 31. Specifically, the sheet 20 in FIG. 5A conveys the sheet step by step by the conveying unit 10 and is detected by the detecting unit 30. In the case of sequential detection in the direction of the arrow J3, the transmission sensor 31 detects the vicinity of the intermediate point of the mount 23, and indicates that the intermediate point between the labels has passed in the waveform diagram of FIG.

  Next, the one-step paper 20 is conveyed by the conveying means 10 (S9), the sensor value of the transmission sensor 31 is input from the A / D circuit 37 by the detecting means 30 (S10), and the input sensor value, maximum value and minimum value are input. And the maximum value and the minimum value are stored in the RAM 43 (S11), and the ratio (percentage) of the input sensor value is calculated using the maximum value and the minimum value as the detected value (S12) (detected value). (Calculation means) The difference between the previous detection value stored in the RAM 43 and the current detection value calculated above is obtained (S13), and the current detection value is stored in the RAM 43 as the previous detection value (S14).

If the difference between the detected values at the two positions is not the label mark determination value (for example, −3 or more), the process returns to S9 (S15) (label mark determination means 52). This process indicates that the change in sensor value by the transmission sensor 31 is not stable. Specifically, the sheet 20 in FIG. 5A conveys the sheet step by step by the conveying unit 10 and detects it. In the case where the means 30 sequentially detects in the direction of the arrow J4, in the waveform diagram of FIG. 5 (b), it shows that the transmission sensor 31 detects the position before the head position of the label.
In S15, if the difference between the detected values at the two positions this time is a label mark determination value (for example, −3 or more), it indicates that the change point Pb has been passed. Specifically, it is determined that the inclination in the waveform diagram of FIG. 5B is stable, and the process proceeds to S16 (S15) (label mark determination means 52).
The top position of the label 22, that is, the end position of the mount 23 (label mark) is obtained, and the process of printing at the top position of the label 22 is performed, and the process returns to S2 (S16).
Accordingly, in steps S9 to S15, the front end of the label 22b is detected by the transmission sensor 31 while the paper 20 is being conveyed, and in step S15, it is determined whether or not the change point is Pb (end position of the label mark). The processing from S9 to S15 is processing for detecting the J4 portion in the graph of FIG.

According to the above embodiment, the sensor value of the transmission sensor 31 is input from the A / D circuit 37, and the change in the sensor value from the mount 23 to the label 22a is monitored by monitoring the change in the difference between the two positions of the sensor value. Can recognize the leading position of the label without the need to set a threshold.
Therefore, in the above embodiment, in the process of moving from the position of only the mount 23 to the position where the label 22 and the mount 23 are located, the waveform of the sensor value input by the transmission sensor 31 is inclined upward (FIG. 5B). It is possible to print at the leading position of the label 22 by finding the leading position of the label 22 by paying attention to the above)).

Next, a label detecting means using the reflection sensor according to the embodiment of the present invention will be described with reference to FIG. 2, FIG. 6 to FIG.
In the following embodiments of the present invention, description will be made using the paper 20 of FIG.

The detection means 30 includes a reflection sensor 34 that detects the amount of reflected light on the paper 21, and an A / D circuit 37 that converts the voltage output from the reflection sensor 34 into a digital value and sends the converted digital value sensor value to the CPU 41. Prepare.
The reflection sensor 34 measures the amount of reflected light of the position detection mark 24 of the marked paper 21 provided on the upstream side of the transport unit 10 and provided on one side of the paper 21. The reflection sensor 34 outputs a predetermined voltage to the A / D circuit 37 according to the amount of reflected light received, and the A / D circuit 37 sends a sensor value obtained by converting the input predetermined voltage to a digital value to the CPU 41.

FIG. 6 is a diagram illustrating a circuit of the reflection sensor 34.
The reflection sensor light emitting element 35 is provided on the side of the mount 23 on which the position detection mark 24 is printed, and emits light at all times or when the marked paper 21 is conveyed.
The reflection sensor light receiving element 36 is provided on the same side as the reflection sensor light emitting element 35 with respect to the mount 23, and is an element that receives light emitted from the reflection sensor light emitting element 35 and reflected by the mount 23. To a predetermined voltage according to
The A / D circuit 37 converts the voltage converted by the reflection sensor light receiving element 36 into a digital value, and outputs the converted digital value to the CPU 41 as a sensor value.

Hereinafter, in the label detection apparatus of the present invention, the operation until the detection unit 30 detects the intermediate point of the label mark (position detection mark) by the reflection sensor 34 will be described with reference to FIGS.
7A and 7B are diagrams for explaining the difference between the sensor output waveform detected by the reflection sensor and the detected value at the two positions. FIG. 7A shows the form of the sheet, FIG. 7B shows the reflection sensor output waveform, and FIG. FIG. 7C is an explanatory diagram for explaining a difference between detection values at two positions obtained from an output waveform of the reflection sensor.

First, in order to detect an intermediate point of the position detection mark 24 shown in FIG. 7, a label mark measurement start value 70c for determining a change point Pc that is an intermediate point of the position detection mark 24 is prepared in advance. .
For example, in the A / D circuit 37 in which the digital output value of the A / D circuit 37 that detects the output voltage of the reflection sensor 34 changes in the range of “0 to 255”, the difference between the detection values at the two positions of the reflection sensor 34 is In the case where the difference between the detection values at the two positions of the reflection sensor 34 changes within the range of “−3 to +3” when only the mount 23 is detected and changes in the range of “−20 to +20”. The label mark measurement start value 70c for starting the measurement of the position detection mark 24 is “−10 or less”. Further, the label mark determination value for determining the change point Pc that is the intermediate point of the position detection mark 24 by the detection means 30 is set to “0 or more”. Further, using the sensor value input from the A / D circuit 37 by the detection means 30 with the value of the reflection sensor 34, the areas of the previously detected value, maximum value and minimum value provided in the RAM 43 are initialized (S1). .

  Next, the one-step paper 21 is conveyed by the conveying means 10 (S2), the sensor value of the reflection sensor 34 is input from the A / D circuit 37 by the detecting means 30 (S3), and the input sensor value, maximum value and minimum value are input. And the maximum value and the minimum value are stored in the RAM 43 (S4), and the ratio (percentage) of the input sensor value is calculated using the maximum value and the minimum value as the detected value this time (S5) (detected value) (Calculation means) The difference between the previous detection value stored in the RAM 43 and the current detection value calculated above is obtained (S6), and the current detection value is stored in the RAM 43 as the previous detection value (S7).

If it is determined that the difference between the detected values at the two positions is not less than or equal to the label mark measurement start value 70c (for example, not less than −10), the process proceeds to S2 (S8) (label mark measurement start determination means 51). This processing indicates that the position is not near the position detection mark 24 by the reflection sensor 34. Specifically, the sheet 21 in FIG. 7A conveys the sheet step by step by the conveying unit 10, and the detecting unit 30 indicates that the reflection sensor 34 detects the position where the label 22a without the position detection mark 24 is present in the case where the detection is sequentially performed in the direction of the arrow J5.
Therefore, in steps S2 to S8, the position detection mark 24 is detected by the reflection sensor 34 while the paper 21 is being conveyed, and in step S8, it is determined whether label mark measurement is started. The processing from S2 to S8 is processing for detecting the J5 portion in the graph of FIG.

  If it is determined in S8 that the difference between the detected values at the current two positions is not more than the label mark measurement start value 70c (for example, −10 or less), the process goes to S9. This processing indicates that the position near the tip of the position detection mark 24 is indicated by the reflection sensor 34. Specifically, the paper 21 in FIG. 7A conveys the paper step by step by the conveying means 10, In the case where the detection means 30 sequentially detects in the direction of the arrow J5, the reflection sensor 34 detects the tip position of the position detection mark 24. In the waveform diagram of FIG. 7B, the tip of the position detection mark 24 is detected. It shows that the slope of the change in sensor value has changed greatly after passing.

  Next, the one-step paper 21 is conveyed by the conveying means 10 (S9), the sensor value of the reflection sensor 34 is input from the A / D circuit 37 by the detecting means 30 (S10), and the input sensor value, maximum value and minimum value are input. And the maximum value and the minimum value are stored in the RAM 43 (S11), and the ratio (percentage) of the input sensor value is calculated using the maximum value and the minimum value as the detected value (S12) (detected value). (Calculation means) The difference between the previous detection value stored in the RAM 43 and the current detection value calculated above is obtained (S13), and the current detection value is stored in the RAM 43 as the previous detection value (S14).

If the difference between the detected values at the two positions is not the label mark determination value (for example, 0 or more), the process returns to S9 (S15) (label mark determination means 52). This processing indicates that the change in sensor value by the reflection sensor 34 does not pass through the apex. Specifically, the sheet 21 in FIG. 7A conveys the sheet step by step by the conveying unit 10. In the case where the detection means 30 sequentially detects in the direction of the arrow J6, in the waveform diagram of FIG. 7B, the reflection sensor 34 detects a position that is not an intermediate point (vertex) of the position detection mark 24. It shows that.
In S15, if the difference between the detected values at the current two positions is a label mark determination value (for example, 0 or more), it indicates that the change point Pc has been passed. Specifically, it is determined that the vertex in the waveform diagram of FIG. 7B has been passed, and the process proceeds to S16 (S15) (label mark determination means 52).
An intermediate point of the position detection mark 24 is obtained, and the position transported by a fixed distance from the position is set as the leading position of the label 22, so that the printing process is performed at the leading position of the label 22 and the process returns to S2 (S16).
Accordingly, in steps S9 to S15, the intermediate point of the position detection mark 24 is detected by the reflection sensor 34 while the paper 21 is being conveyed, and in step S15, it is determined whether or not the change point Pc. The processing from S9 to S15 is processing for detecting the J6 portion in the graph of FIG.

According to the embodiment described above, the sensor value of the reflection sensor 34 is input from the A / D circuit 37, and the change in the difference between the two positions of the sensor value is monitored, whereby the sensor from the mount 23 to the position detection mark 24 is detected. Since the change in value can be recognized, it is not necessary to set a threshold value, and the leading position of the label can be detected.
Therefore, in the above embodiment, in the process of moving from the mount 23 to the position of the position detection mark 24, the waveform of the sensor value input by the reflection sensor 34 is inclined upward (FIG. 7B). Paying attention, an intermediate point of the position detection mark 24 is obtained, and the position transported by a fixed distance from the position is set as the leading position of the label 22, so that printing can be performed at the leading position of the label 22.

In the above embodiment, the example has been described in which the ratio (percentage) is obtained as the detection value from the maximum and minimum sensor values acquired by the detection means 30 and the input sensor value. Therefore, the ratio may not be calculated and the sensor value may be used as a detection value or may be changed as appropriate.
In the above embodiment, the previous detection value and the current detection value calculated, that is, the difference (inclination) between the detection value of the previous step by the transport unit 10 and the current detection value is described. The difference between the average detection value three steps before and the current detection value, or the difference between the average detection value three steps from the present six steps and the average detection value three steps before the present including the present, Any method can be used as long as it can detect the slope of the waveform by comparing the detection values, and may be changed as appropriate. Use of the above is useful when the output voltage of the sensor of the detection means 30 is affected by electrical noise such as the conveyance motor 12.

  Further, in the above-described embodiment, the description has been made in which the values for determining the changing point Pa, the changing point Pb, the changing point Pc, or the changing point Pd are prepared as fixed values in the ROM 42, but on the setting screen of the operation unit 44 It is also possible to set in the RAM 43 or by a communication command from the host computer through the external I / F unit 45.

In the above embodiment, the label detection apparatus 100 having the configuration including the print head 15 has been described. However, the present invention is not limited to this, and the present invention is incorporated into the label detection apparatus 100 that does not have the print head 15. Needless to say, this is possible.
Moreover, in the said embodiment, although the sensor provided the sensor of both the permeation | transmission sensor and the reflection sensor, the sensor may be only one of a permeation | transmission sensor or a reflection sensor.

It is a figure which shows the label detection apparatus which concerns on embodiment of this invention. It is a figure which shows the form of the paper used by this embodiment, (a) is a figure which shows the form of the paper used with a permeation | transmission sensor, (b) is a figure which shows the form of the paper used with a reflection sensor. It is a block diagram of the control part in the label detection apparatus of this Embodiment. It is a figure explaining the circuit of a permeation | transmission sensor. It is a figure explaining the difference of the sensor output waveform which detected the paper with the transmission sensor, and the detected value of 2 positions, (a) is a form of a paper, (b) is a transmission sensor output waveform, (c) is an output waveform of a transmission sensor. It is explanatory drawing for demonstrating the difference of the detected value of 2 positions calculated | required by (1). It is a figure explaining the circuit of a reflection sensor. It is a figure explaining the difference of the sensor output waveform which detected the paper with a mark with the reflection sensor, and the detected value of 2 positions, (a) is a form of a paper, (b) is a reflection sensor output waveform, (c) is a reflection sensor. It is explanatory drawing for demonstrating the difference of the detected value of 2 positions calculated | required with the output waveform. It is a figure which shows the sensor output waveform and difference which detected the paper with a mark with the reflection sensor. It is a flowchart explaining the operation | movement for detecting a label mark by a detection means. It is a figure which shows the label detection method by the conventional transmission sensor. It is a figure which shows the label detection method by the conventional transmission sensor. It is a figure which shows the label detection method by the conventional reflective sensor.

DESCRIPTION OF SYMBOLS 100 Label detection apparatus 10 Conveyance means 11 Motor control part 12 Conveyance motor 13 Platen roller 14 Print control part 15 Print head 20 Paper 21 Marked paper 22, 22a, 22b Label 23 Mount 24 Position detection mark 25 Printing part 30 Detection means 31 Transmission sensor 32 Transmission sensor light emitting element 33 Transmission sensor light receiving element 34 Reflection sensor 35 Reflection sensor light emitting element 36 Reflection sensor light receiving element 37 A / D circuit 40 Control unit 41 CPU
42 ROM
43 RAM
44 Operation unit 45 External I / F unit 50 Storage unit 51 Label mark measurement start determination unit 52 Label mark determination unit 70a, 70b, 70c Label mark measurement start value

Claims (3)

Transport means for transporting paper having a label mark;
Detecting means for detecting a sensor value of a label mark of the paper conveyed by the conveying means;
Storage means for storing the sensor value detected by the detection means for each step drive of the transport means;
Label mark measurement for determining the start of label mark measurement by obtaining the difference between the sensor value detected by the detection means in the previous step drive of the transport means and stored by the storage means and the current sensor value detected by the detection means Start determination means;
After the label mark measurement start determination means determines that label mark measurement has started, the detection value detected by the detection means in the previous step drive of the transport means and the current value detected by the storage means Label mark determination means for determining the difference between the sensor values of the label mark and determining the middle position or the end position of the label mark;
A label detection apparatus comprising: Transport means for transporting paper having a label mark;
Detecting means for detecting a sensor value of a label mark of the paper conveyed by the conveying means;
A detection value calculation means for calculating the sensor value detected by the detection means as a ratio and making it a detection value;
A storage means for calculating a detection value by the detection value calculation means from a sensor value detected by the detection means for each step drive of the transport means, and storing the detection value;
A label mark measurement start determining unit for determining a measurement start of the label mark by obtaining a difference between the detection value stored by the storage unit and the detection value detected by the detection unit and calculated by the detection value calculation unit;
After determining that the label mark measurement start is determined by the label mark measurement start determination unit, the difference between the detection value stored by the storage unit and the detection value detected by the detection unit and calculated by the detection value calculation unit is obtained. Label mark determination means for determining the intermediate position or end position of
A label detection apparatus comprising: The label detection unit according to claim 1, further comprising an input unit that sets initial values of the label mark measurement start determination unit and the label mark determination unit.

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