JP2010202307A - Method for detecting recording paper and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for detecting recording paper accurately detecting the presence or absence of recording paper by using a transmissive photosensor and a reflective photosensor even to label paper using a thin continuous paper or transparent mount. <P>SOLUTION: In a conveyance passage A of a printer 1, the transmissive photosensor 26 and the reflective photosensor 27 are arranged. As thresholds for determination of the transmissive photosensor 26, two-stage thresholds of a lower side transmitted light amount threshold SLt and an upper side transmitted light amount threshold SHt are set, and as thresholds for determination of the reflective photosensor 27, two-stage thresholds of a lower side reflective light amount threshold SLr and an upper side reflective light amount threshold SHr are set. When printing is performed in a label paper P1, a label paper P2 with a mark, a continuous paper P3 with a mark, and a continuous paper P4 without a mark, the level of detection output of the transmissive photosensor 26 and the reflective photosensor 27 is determined by using the thresholds for determination in accordance with the kinds of paper, and the presence or absence of the recording paper 12a and the kind of paper of the recording paper 12a are determined based on a determination result. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a printer that detects various recording media such as label paper, marked recording paper, and continuous paper with transmissive and reflective optical sensors, and a recording paper detection method in such a printer.

Label paper with labels attached at regular intervals on a long mount, continuous continuous paper, or recording paper with marks that have black marks or other marks printed on the surface of continuous paper or label paper at regular intervals, etc. In these printers that print on various types of recording paper, a printer in which a reflective or transmissive optical sensor is arranged along the recording paper conveyance path is used. In such a printer, transmitted light transmitted through the recording sheet or reflected light from the recording sheet is received (detected) by an optical sensor while the recording sheet is conveyed, and the recording sheet is detected based on the result of the received light output (detected output). Detection of presence / absence, paper type, label / mark position on recording paper, etc.

Patent Document 1 describes a printer in which a reflection type photo sensor and a transmission type photo sensor are arranged facing each other across a conveyance path of a recording paper. The printer of Patent Document 1 determines the amount (high or low) of the amount of light received (detected light amount) by the reflective photosensor and the transmissive photosensor, and based on the combination of the high and low determination results, the presence or absence of recording paper and positioning on the recording paper The end of the label as a reference, the position of the mark, and the like are detected, and the paper type of the recording paper is determined.

JP 2007-106556 A

Here, although a method for setting a threshold value used for the determination of the level of the detected light amount by the reflection type photosensor and the transmission type photosensor is not described in detail in Patent Document 1, as described below, as described below, Depending on the type, the presence or absence of recording paper may not be detected accurately.

FIG. 7A is an explanatory diagram showing threshold values of a conventional transmissive photosensor. The amount of received light that has passed through the detection target by the transmission type photosensor is defined as the amount of transmitted light on the vertical axis. As shown in this figure, the threshold value St of the transmissive photosensor is set higher than the level of the transmitted light amount L1 from the label portion and lower than the level of the transmitted light amount L2 from the mount portion. In addition, FIG.
These are explanatory drawings which show the threshold value of the reflection type photosensor of the conventional example. The amount of light received by the reflection type photosensor that reflects the detection target is defined as the amount of reflected light on the vertical axis. As shown in this figure, the threshold value Sr of the reflection type photosensor is higher than the level of the reflected light amount L3 from the mark portion of the marked recording paper, and the reflected light amount L4 from the ground color portion of the paper not marked. It is set to be lower than the level.

According to the setting of the threshold value St as described above, the light reception output (detection output) of the transmission type photosensor.
Based on this, it is possible to detect the label by detecting the change in the amount of transmitted light between the mount portion and the label portion.
At this time, a case where the mount portion is a transparent mount or the like having a higher transmittance may be considered. However, since the transmitted light amount L5 from the transparent mount is further larger than the transmitted light amount L2 from the normal opaque mount, The label can be detected as in the case.

Here, when the recording paper is not a label paper but a continuous paper, normally, the continuous paper is thicker than the mount of the label paper, and the continuous paper has a lower transmittance. Therefore, it is assumed that the light reception output (detection output) of the transmissive photosensor for continuous paper is always lower than the threshold value St. Therefore, it was possible to detect the presence or absence of continuous paper based on the detection output of the transmission type photosensor.

However, when thin continuous paper or the like having a higher transmittance than before is used, the level of the transmitted light amount L6 from the thin continuous paper may be higher than the threshold value St. Therefore, in such a case, there is a problem that erroneous detection occurs when the presence or absence of continuous paper is detected based on the detection output of the transmissive photosensor.

On the other hand, according to the setting of the threshold value Sr as described above, a change in the amount of reflected light between the mark portion and the ground color portion of the paper is detected on the basis of the light reception output (detection output) of the reflective photosensor, and the continuous paper And black marks on the front or back of the label paper can be detected.

Here, when the recording paper is a continuous paper or label paper without a mark, it is normally assumed that the amount of reflected light from the continuous paper or label paper without a mark is always higher than the threshold value Sr. The For this reason, it is possible to detect the presence or absence of unmarked continuous paper or the presence of label paper based on the detection output of the reflective photosensor.

However, when a label sheet with a label attached to a transparent mount is used, the amount of reflected light L7 from the transparent mount is unstable and may be lower than the threshold value Sr. Further, the amount of light reflected from the low reflectance mount having a lower reflectance than usual may always be lower than the threshold value Sr. Therefore, in such a case, there is a possibility that the portion of the low reflectance mount including the transparent mount is erroneously determined as a mark. Further, if the presence or absence of label paper using a low-reflectance mount including a transparent mount is detected based on the detection output of the reflective photosensor, there is a problem in that erroneous detection occurs.

In view of the above problems, an object of the present invention is to detect a mark or a label on a recording sheet using a reflection type photosensor and a transmission type photosensor, and to detect the presence or absence of the recording sheet using these sensors. It is an object of the present invention to propose a recording paper detection method that can accurately detect the presence / absence of a recording paper even on a label paper using a low-reflectance mount such as a thin continuous paper or a transparent mount.

In order to solve the above problems, the present invention provides a recording sheet detection method in a printer that selectively loads a plurality of recording sheet types.
A reflection type photo sensor and a transmission type photo sensor are installed in the conveyance path for conveying the recording paper,
A plurality of reflected light amount threshold values used for determination of the light reception output by the reflection type photosensor are set in advance, and a plurality of transmission light amount threshold values used for determination of the light reception output by the transmission type photosensor are set in advance,
When printing or transporting the recording paper,
Before starting the printing or conveyance, set any one of the plurality of reflected light amount thresholds and one of the plurality of transmitted light amount thresholds as a determination threshold,
The presence or absence of the recording paper or the paper type in the transport path is detected based on the determination threshold and the light reception outputs of the reflective photosensor and the transmissive photosensor.

In the present invention, a plurality of threshold values are set for each of the reflection type photo sensor and the transmission type photo sensor in this way, so that an appropriate combination of threshold values is selected according to the paper type of the recording paper and its specifications. Can be used properly. As a result, it is highly likely to be erroneously detected with the same threshold setting as other recording papers, such as thin continuous paper with high transmittance and reflectance, and label paper using low reflectance board including transparent backing paper, etc. Can use different thresholds. Therefore,
Presence / absence of recording sheets of various paper types, paper types and positions, etc. can be detected with high accuracy, and the occurrence of erroneous detection can be suppressed.

In the present invention, the received light output of the transmissive photosensor is higher than the transmitted light amount threshold set as the determination threshold, and the received light output of the reflective photosensor is set as the determination threshold. If it is lower than that, it can be determined that the recording sheet is out of paper in the transport path. When there is no recording paper at the detection position of the transmission type photosensor and reflection type photosensor, the light reception output (detection output) of the reflection type photosensor is low and the light reception output (detection output) of the transmission type photosensor is low. Is expected to be high. Therefore, by combining the determination results of the detection outputs of these two sensors, the presence or absence of recording paper can be detected with higher accuracy.

Further, when the recording paper of the plurality of paper types includes a label paper in which a label is pasted on a long mount and a recording paper with a mark having a mark attached at a constant interval, the label paper When printing or transporting, the label is detected based on the light receiving output of the transmissive photosensor, and when printing or transporting the marked recording paper, the label is detected based on the light receiving output of the reflective photosensor. Marks can be detected. Thus, since the label portion has a lower transmittance than the mount portion, a transmissive photosensor can be used as the label detector. In addition, since the mark portion has a lower reflectance than the portion other than the mark, a reflective photosensor can be used as the mark detector. In addition, as described above, if the presence or absence of the recording paper is detected based on the detection output of the label detection or mark detection sensor, it is not necessary to provide a dedicated sensor for detecting the presence or absence of the recording paper.

Here, when the recording paper of the plurality of paper types includes continuous paper having a higher transmittance than the label, the plurality of transmitted light amount thresholds are higher than the transmitted light amount transmitted through the label, and When printing or transporting the label paper by including a lower transmitted light amount threshold value lower than the transmitted light amount transmitted through the mount of the label paper and an upper transmitted light amount threshold value higher than the transmitted light amount transmitted through the continuous paper The lower transmitted light amount threshold value may be used as the determination threshold value, and when the continuous paper is printed or conveyed, the upper transmitted light amount threshold value may be used as the determination threshold value. In this way, since the amount of light transmitted from continuous paper having a higher transmittance than the label portion is always lower than the threshold value, determination of the presence or absence of recording paper by combining the detection output of the transmission type photosensor and the reflection type photosensor Can prevent erroneous determination. Also, for such continuous paper, it is not necessary to detect the label as a positioning reference on the recording paper, and it is only necessary to detect the mark. Therefore, instead of the lower transmission light amount threshold value that is normally used as the threshold value for label detection, Even if the upper transmitted light amount threshold is used, the positioning reference is not erroneously detected. Therefore, the detection accuracy in the absence of paper can be improved without reducing the detection accuracy of the positioning reference.

Further, when the recording paper of the plurality of paper types includes a label paper using a low-reflectance mount as the mount, the reflected light amount by the mark portion of the marked recording paper is set to the plurality of reflected light amount threshold values. And an upper reflected light amount threshold value lower than the reflected light amount by the portion other than the mark of the marked recording paper and a lower reflected light amount threshold value lower than the reflected light amount by the low reflectance mount, When printing or transporting attached recording paper, the upper reflected light amount threshold value is used as the determination threshold value, and when performing printing or transporting of the low-reflectance mount label paper, the lower reflected light amount threshold value is used for the determination. It is good to use as a threshold value. In this way, unstable reflected light from the transparent mount and low reflected light from other low-reflectance mounts are always higher than the threshold, so the detection output of the transmissive photosensor and reflective photosensor It is possible to prevent erroneous determination in the determination of the presence or absence of recording paper by the combination of Further, in the case of a label paper using a low reflectance mount including such a transparent mount, the detected label end can be used as a positioning reference, and there is no need to detect a mark. Even if the lower reflected light amount threshold value is used instead of the normally used upper reflected light amount threshold value, the positioning reference is not erroneously detected. Therefore, the detection accuracy in the absence of paper can be improved without reducing the detection accuracy of the positioning reference.

Further, the present invention is a recording paper detection method in a printer that selectively loads recording paper of a plurality of paper types,
A reflection type photo sensor and a transmission type photo sensor are installed in the conveyance path for conveying the recording paper,
At least two reflected light amount threshold values used for determination of the received light output by the reflective photosensor are set in advance, and at least two transmitted light amount threshold values used for determination of the received light output by the transmissive photosensor are set in advance. ,
When printing on the recording paper or transporting the recording paper,
In addition to setting the paper type of the recording paper, any one of the plurality of reflected light amount threshold values and one of the plurality of transmitted light amount threshold values are set as determination threshold values,
The presence / absence of the recording paper or the paper type in the transport path is detected based on the determination threshold value and light reception outputs of the reflection type photosensor and the transmission type photosensor.
In this way, by setting the optimum one of the reflected light amount threshold value and the transmitted light amount threshold value as the determination threshold value together with the paper setting of the recording paper, occurrence of erroneous detection can be suppressed.

Here, before the printing on the recording paper or the conveyance of the recording paper is started, the determination threshold value can be set based on a command received from the host apparatus. In this way, there is no need to manually operate the printer when performing printing. If a command corresponding to the paper type is included in the print job, it is not necessary to transmit a threshold setting command separately from the print job.

Next, the printer of the present invention is
The presence or absence of the recording paper in the conveyance path is detected by the recording paper detection method described above.

According to the present invention, a plurality of threshold values are set for each of the reflection type photo sensor and the transmission type photo sensor, and an appropriate combination of threshold values is selected according to the paper type of the recording paper and used as the determination threshold value. This makes it possible to use an appropriate threshold depending on the paper type of the recording paper. If the same threshold setting is used for other recording papers, there is a high possibility of erroneous detection. Different threshold values can be used for label paper using a low-reflectance mount including a transparent mount. Therefore, it is possible to accurately detect the presence / absence of recording sheets of various paper types, paper types, positions, and the like, and to suppress the occurrence of erroneous detection.

1 is an external perspective view of a printer to which the present invention is applied. It is a longitudinal cross-sectional view which shows the internal structure of a printer. It is a schematic block diagram which shows the control system of a printer. It is explanatory drawing of a recording paper. It is explanatory drawing of the threshold value for determination of a transmission type photosensor and a reflection type photosensor. It is a setting table of recording paper detection modes. It is explanatory drawing of the threshold value for determination of the transmission type photosensor of a prior art example, and a reflection type photosensor.

  Embodiments of a printer to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
FIG. 1 is an external perspective view of a printer according to the present invention, and FIG. 2 is a longitudinal sectional view of the printer. The printer 1 includes a printer body 2 having a substantially rectangular parallelepiped shape as a whole, and an opening / closing lid 3 attached to the front surface of the printer body 2. A discharge port 4 having a predetermined width is formed on the front surface of the outer case of the printer body 2. When the paper discharge guide 5 mounted on the opening / closing lid 3 is pulled forward, the opening / closing lid 3 opens until it becomes almost horizontal with the lower end as the center, and the roll paper storage portion 7 formed inside the printer is opened. It becomes a state. At the same time, the transport path A from the roll paper storage unit 7 to the discharge port 4 is opened. In the roll paper storage unit 7, a roll paper 12 in which a long recording paper 12 a having a constant width is wound in a roll shape is stored so as to be rollable in a horizontally placed state facing the printer width direction.

A head unit frame 9 is horizontally attached to the upper end of the printer main body frame 10 above the roll paper storage unit 7. The head unit frame 9 is provided with an inkjet head 13, a carriage (not shown) on which the inkjet head 13 is mounted, and the like. A platen frame 18 that extends horizontally in the front-rear direction of the printer is disposed below the inkjet head 13. A platen 8 is attached to the upper end of the platen frame 18 horizontally in the printer width direction. The platen 8 is an inkjet head 13.
And the print position of the inkjet head 13 is defined. The platen 8 has a flat rectangular parallelepiped shape that is long in the printer width direction, and defines a printing area in the printer width direction of the inkjet head 13 that reciprocates.

A tension guide 20 that is curved downward is attached to the rear end of the platen frame 18. When the roll paper 12 is loaded into the roll paper storage unit 7, the recording paper 12 a drawn from the roll paper 12 is drawn upward along the conveyance path A passing through the feeding roller 20 a and the tension guide 20, and then forward. It is pulled out so as to be bent, and is pulled out from the rear end of the platen 8 to the horizontal portion of the transport path A via the printing position by the inkjet head 13. And it is conveyed along the horizontal part of the conveyance path A by the recording paper conveyance means provided with a paper feed motor and a paper feed roller.

The recording paper 12 a pulled out from the roll paper 12 is conveyed while being sucked to the surface of the platen 8 by the recording paper conveying means, and passes through the printing position by the inkjet head 13. At the printing position, printing is performed by the inkjet head 13 mounted thereon while reciprocating the carriage in the paper width direction. After a series of line printing in the width direction of the recording paper 12a is completed, the recording paper conveying means is driven to feed the recording paper 12a by a predetermined pitch. After this, the next line printing is performed. Thus, the recording paper 12a is printed by the inkjet head 13 while being intermittently sent out at a predetermined pitch. Thereafter, the conveyance is stopped in a state in which the printed recording paper 12a is discharged from the discharge port 4, and the print portion of the recording paper 12a is cut by an auto cutter arranged in the vicinity of the discharge port 4, and the printed recording paper piece Is issued.

(sensor)
A transmission type photosensor 26 and a reflection type photosensor 27 are disposed on the upstream side of the inkjet head 13 in the transport path A. The transmissive photosensor 26 includes a light emitting element disposed on the upper side of the conveyance path A and a light receiving element disposed on the lower side. The transmissive photosensor 26 irradiates inspection light toward the conveyance path A from above and transmits downward. Detect light. Reflective photo sensor 27
Is equipped with a light emitting element and a light receiving element, and irradiates inspection light toward the transport path A from below,
The reflected light returning downward is detected. Note that the light-emitting element and the light-receiving element of the transmissive photosensor 26 may be arranged oppositely across the conveyance path.

(Control system)
FIG. 3 is a schematic block diagram illustrating a control system of the printer 1. The control system of the printer 1 is configured around a control unit 30 including a storage unit 31 such as a CPU, ROM, and RAM. The storage unit 31 stores a threshold used for control, a control program, and the like.

A host device 32 such as a host computer is connected to the input side of the control unit 30, and a print command and print data are supplied from the host device 32 to the control unit 30. Also, the control unit 30
A transmissive photosensor 26 and a reflective photosensor 27 are connected to the input side. When the control unit 30 receives a print command or print data from the host device 32, the control unit 30 detects the recording paper 12 a on the conveyance path A based on the detection outputs of the transmissive photosensor 26 and the reflective photosensor 27. In addition, the control unit 30 determines that the roll paper 12 has been replaced when the opening / closing of the roll paper storage unit 7 is detected based on the detection output of an open / close detector (not shown), and the newly loaded recording is performed. The paper 12a is detected and a cueing operation is performed.

The inkjet head 13 is connected to the output side of the control unit 30 via a head driver 13a.
And a carriage motor (not shown) and a paper feed motor (not shown) are connected via a motor driver. The control unit 30 drives and controls the carriage motor based on the print command and print data received from the host device 32 to print on the recording paper 12a while moving the inkjet head 13 in the width direction of the platen 8,
By driving and controlling the paper feed motor, the recording paper 12a is conveyed by a predetermined amount in conjunction with the operation of the inkjet head 13. In addition, the control unit 30 performs a conveying operation for aligning the printing start position on the recording paper 12a with the printing position defined on the platen 8, and the printed portion of the recording paper 12a up to the cutting position by the auto cutter. Carry out the transfer operation to send out.

(Recording paper detection method)
FIG. 4 is an explanatory diagram of the recording paper 12a used as the printing paper of the printer 1. The printer 1 has a label paper P1 attached to the surface of a long release board 12b in a state where a regular label 12c can be peeled at regular intervals, and a black mark 12d is attached to a predetermined position on each label 12c. A plurality of types of recording paper 12a, such as a labeled paper P2 with a mark, a continuous paper P3 with a black mark 12d on the surface of the continuous paper, and a non-marked continuous paper P4 without a black mark 12d. Is assumed to be used as printing paper. Here, the label paper P1 and the marked label paper P2 include the peeling mount 12b.
And a low-reflectance mount (including a mount with a high transmittance and an unstable amount of reflected light, such as a transparent mount). Further, the continuous paper P3 with marks and the continuous paper P4 without marks include paper that is thinner and has a higher transmittance than before.

FIG. 5A is an explanatory diagram of the determination threshold value of the transmissive photosensor 26, and FIG. 5B is an explanatory diagram of the determination threshold value of the reflective photosensor 27. In the present embodiment, the recording paper 12a is detected by detecting the presence or absence of the recording paper 12a of each paper type and the label or mark on the recording paper 12a.
In order to determine the paper type, two upper and lower threshold values as shown in FIGS. 5A and 5B are set for each sensor.

Two thresholds for the transmissive photosensor 26 include the label 12 on the label paper P1.
a lower transmitted light amount threshold SLt that is higher than the transmitted light amount L1 that passes through the part to which c is attached and lower than the transmitted light amount L2 that passes through the part of the peeling mount 12b, and the continuous paper P3 with marks or the continuous paper without marks Upper transmitted light amount threshold value S higher than transmitted light amount L6 transmitted through each part of P4
Two of Ht are set. Here, the upper transmitted light amount threshold value SHt is the continuous paper P3 with a mark.
Alternatively, since it is set on the assumption that thin paper with high transmittance is used as the unmarked continuous paper P4, the value is higher than the lower transmission light amount threshold SLt. The upper transmitted light amount threshold value SHt is lower than the transmitted light amount L5 when a high transmittance mount such as a transparent mount is used as the peeling mount 12b.

On the other hand, the two threshold values for the reflective photosensor 27 are higher than the amount of reflected light L3 by the portion of the black mark 12d attached to the marked continuous paper P3 and the marked label paper P2, and other than the black mark 12d. Reflected light quantity L by the part (the background part of the paper)
Two threshold values are set: an upper reflected light amount threshold value SHr lower than 4 and a lower reflected light amount threshold value SLr that is surely lower than the reflected light amount L7 by the peeling mount 12b using the low reflectance mount including the transparent mount. Here, the upper reflected light amount threshold value SHr is set on the assumption that the ground color portion of the paper is neither transparent nor low in reflectance, and the lower reflected light amount threshold value SLr is the reflected light amount as the peeling mount 12b. Is set on the assumption that a low reflectance mount including an unstable transparent mount is used. Accordingly, the lower reflected light amount threshold SLr is lower than the upper reflected light amount threshold SHr.

FIG. 6 is a setting table of recording sheet detection modes set in association with each sheet type of the recording sheet 12a. In this table, the thresholds for determination used in each recording paper detection mode and the assumed results when the transmitted light amount or the reflected light amount from the recording paper 12a is determined using these determination threshold values (presumed sensors) Detection output). Assumed results of the height determination are indicated by “H” when the transmitted light amount or the reflected light amount is higher than the determination threshold, and when it is low,
L ”. In addition, this setting table shows criteria for determining the presence or absence of the recording paper 12a and criteria for determining the paper type of the recording paper 12a.

The control unit 30 includes a command for setting a recording sheet detection mode corresponding to the recording sheet 12a to be printed from the host device 32 at a predetermined timing before being included in the print command or print data, or at a predetermined timing before the start of printing. Receive. When the control unit 30 receives this command, the SL 30
Of the threshold values t, SHt, SLr, and SHr, a combination of threshold values set in association with the recording sheet detection mode specified by the command is set as a determination threshold value. The combination of threshold values corresponding to each recording sheet detection mode may be stored in advance in the storage unit 31 of the control unit 30 or may be included in a command for setting the recording sheet detection mode. Further, data specifying the paper type of the recording paper 12a to be printed is included in the print command and print data, and the recording paper detection mode and determination threshold value stored in advance in the storage unit 31 based on the paper type. May be read and set.

When receiving a print command or print data from the host device 32, the control unit 30 conveys the recording paper 12 a to the printing position by the inkjet head 13 and starts printing. At this time, the recording paper 12a is detected at the detection position by the transmissive photosensor 26 and the reflective photosensor 27. That is, the detection operation by the transmissive photosensor 26 and the reflective photosensor 27 is performed while conveying the recording paper 12a for a predetermined length or more, and the detection outputs of the transmissive photosensor 26 and the reflective photosensor 27 are used for the current determination. It is determined whether the value is higher or lower than the value set as the threshold value. Based on the determination result, the presence or absence of the recording paper 12a is determined. When the recording paper 12a is detected, that is, when it is determined that the recording paper 12a is not in the no-paper state, the paper type of the recording paper 12a is determined.

Here, the presence / absence of the recording paper 12a and the determination of the paper type in each recording paper detection mode will be described. First, when the recording paper detection mode is the label detection mode for printing the label paper P1, the lower transmission light amount threshold SLt is selected as the threshold of the transmissive photosensor 26, and the threshold of the reflective photosensor 27 is The lower reflected light amount threshold value SLr is selected. In this setting, when the recording paper 12a loaded in the printer 1 is the label paper P1 or the marked label paper P2, the determination result for the transmitted light amount is always “at the position of the peeling mount 12b.
H ”and always“ L ”at the position of the label 12c. This result is the same when the peeling mount 12b is a transparent mount. Further, when the recording paper 12a loaded in the printer 1 is the continuous paper P3 with marks or the continuous paper P4 without marks, when the transmittance of these continuous papers is low, it becomes “L” and the transmittance is low. When it is high, it becomes “H”. On the other hand, the determination result for the reflected light amount is that the lower reflected light amount threshold value SLr is selected as the determination threshold value.
Label paper P1, labeled paper P2 with mark, continuous paper P3 with mark, continuous paper P4 without mark
It is always “H” for all the recording sheets 12a.

Here, the criteria for determining the presence or absence of the recording paper 12a, that is, the condition for determining that there is no paper, are as follows. The transmitted light amount is “H” and the reflected light amount is “ L ". In the label detection mode, with respect to the amount of reflected light, a determination result of “H” is always obtained for any type of recording paper 12a. Accordingly, if it is determined that there is no paper according to this determination criterion, it is erroneously determined that the recording paper 12a is out of paper when the recording paper 12a is present at a detection position by the transmissive photosensor 26 and the reflective photosensor 27. There is no.

If it is determined in the label detection mode that there is no paper, the paper type is determined based on the detection output of the transmissive photosensor 26. That is, in this case, the detection output of the transmissive photosensor 26 is monitored while the recording paper 12a is conveyed at least as long as the length of each label 12c in the conveying direction (label length). It is determined whether or not the detection output has changed from “H” to “L” or vice versa. In the label detection mode, the lower transmitted light amount threshold value SLt is selected as the threshold value of the transmissive photosensor 26. Therefore, the position of the end of the label 12c can be detected based on the detection output of the transmissive photosensor 26. Therefore, it is possible to perform printing based on the detected position of the end of the label 12c. On the other hand, when there is no change, it is determined that the loaded recording paper 12a is the marked continuous paper P3 or the unmarked continuous paper P4. In this case, since the recording paper 12a having a paper type different from that to be printed is detected, the control unit 30 determines that the paper type is different and performs predetermined error processing.

Next, when the recording paper detection mode is the BM detection mode for printing the marked continuous paper P3, the upper transmission light amount threshold SHt is selected as the threshold of the transmission photosensor 26, and the reflection photosensor 27 As the threshold value, the upper reflected light amount threshold value SHr is selected. In this setting, the determination result for the transmitted light amount is always “L” when the recording paper 12a loaded in the printer 1 is the continuous paper P3 with marks or the continuous paper P4 without marks. In the case of the label paper P1 or the labeled label paper P2, the label 12c is always “L”.
However, at the position of the peeling mount 12b, it becomes “H” if the peeling mount 12b is a transparent mount, and “L” or “H” if it is not a transparent mount. On the other hand, the determination result for the reflected light amount is always “L” for the black mark 12d portion of the labeled paper P2 with marks or the continuous paper P3 with marks, but for a mount with a unstable reflected light amount such as a transparent mount. “L” or “H” for the portion, and in the case of a low reflectance mount other than the transparent mount, the amount of reflected light is “L”. And the normal peeling mount 1 whose reflected light quantity is neither unstable nor low reflectivity
It becomes “H” for the portion 2b and the portion excluding the black mark 12d of the label 12c.

The criterion for determining the presence or absence of the recording paper 12a in the BM detection mode is that the amount of transmitted light is “H” and the amount of reflected light is “L”, as in the label detection mode. In the BM detection mode,
For the continuous paper P3 with mark and the continuous paper P4 without mark, the upper transmitted light amount threshold value SHt
Therefore, the determination result for the transmitted light amount is always “L”, and there is no erroneous determination that there is no paper. For the label paper P1 or the labeled label paper P2, the determination result with respect to the amount of transmitted light at the position of the label 12c is always “L”, so that the recording paper 12a is conveyed at least as long as the length of the gap between labels. If the detection output is monitored, the determination result for the transmitted light amount is always “L”. Therefore, if it is determined that there is no paper according to this determination criterion, the recording paper 12a is transferred to the transmissive photosensor 26 and the reflective photosensor 27.
When it is present at the detection position, the paper is not erroneously determined to be out of paper.

If it is determined in the BM detection mode that there is no paper, the paper type is determined based on the detection output of the reflective photosensor 27. That is, in this case, the detection output of the reflective photosensor 27 is monitored while the recording paper 12a is transported by a length in the transport direction of each label 12c (label length). Detection output is “H”
It is determined whether or not it has changed from “L” to “L” or vice versa. In the BM detection mode, the upper reflected light amount threshold value SHr is selected as the threshold value of the reflective photosensor 27. Therefore, the position of the black mark 12d can be detected based on the detection output of the reflective photosensor 27, and printing can be performed using the detected position of the black mark 12d as a reference. On the other hand, when the black mark 12d is not detected, it is determined that the loaded recording paper 12a is the label paper P1 or the unmarked continuous paper P4. In this case, since the recording paper 12a having a paper type different from that to be printed is detected, the control unit 30 determines that the paper type is different and performs predetermined error processing.

Subsequently, when the recording paper detection mode is the BM label detection mode for printing the marked label paper P2, the lower transmission light amount threshold SLt is selected as the threshold of the transmission photosensor 26, and the reflection photosensor. As the threshold value 27, the upper reflected light amount threshold value SHr is selected.
In this setting, as in the label detection mode, the determination result for the transmitted light amount is always “H” at the position of the peeling mount 12b including the transparent mount, and is always “L” at the position of the label 12c. Further, for the continuous paper P3 with marks and the continuous paper P4 without marks, it becomes “L” when the transmittance of the continuous paper is low, and becomes “H” when the transmittance is high. On the other hand, the determination result for the amount of reflected light is always “
“L”, but “L” or “H” for a portion of the mount such as a transparent mount where the amount of reflected light is unstable. In the case of a low reflectance mount other than the transparent mount, the amount of reflected light is “L”. " Then, it is “H” for the portion of the normal peeling mount 12b where the amount of reflected light is not unstable and the reflectance is not low, and the portion of the label 12c excluding the black mark 12d.

The criteria for determining the presence or absence of the recording paper 12a in the BM label detection mode, that is, the condition for determining that there is no paper is the same as in the label detection mode and the BM detection mode. The amount of light is “L”. In the BM label detection mode,
As for the label paper P1 or the labeled label paper P2, as in the BM detection mode, the determination result with respect to the amount of transmitted light at the position of the label 12c is always “L”, so that the recording paper 12a is at least longer than the length of the gap between labels. If the detection output during monitoring is monitored, the determination result for the transmitted light amount is always “L”. On the other hand, for the continuous paper P3 with marks or the continuous paper P4 without marks, the determination result for the amount of reflected light is always “H” for the portions other than the black mark 12d, so at least the length of the black mark 12d in the transport direction. If the detection output during the conveyance of the recording paper 12a is monitored, the determination result for the transmitted light amount is always “
H ". Therefore, if it is determined that there is no paper according to this determination criterion, it is erroneously determined that the recording paper 12a is out of paper when the recording paper 12a is present at a detection position by the transmissive photosensor 26 and the reflective photosensor 27. There is no.

If it is determined in the BM label detection mode that there is no paper, the paper type is determined based on the detection output of the reflective photosensor 27. That is, in this case, B
Similar to the M detection mode, the black mark 12d is detected based on the detection output of the reflective photosensor 27 while the recording paper 12a is conveyed for the label length or longer, and the detected black mark 12 is detected.
Printing can be performed based on the position of d. On the other hand, when the black mark 12d is not detected, the loaded recording paper 12a is different from the printing target, so that it is determined that the paper type is different and predetermined error processing is performed.

Subsequently, when the recording paper detection mode is the continuous paper detection mode for printing the unmarked continuous paper P4, the upper transmission light amount threshold value SHt is selected as the threshold value of the transmission type photosensor 26, and the reflection type photosensor 27 is selected. As the threshold value, the upper reflected light amount threshold value SHr is selected. This setting is the same setting as the BM detection mode described above. In addition, the determination criterion for the presence or absence of the recording paper 12a in this continuous paper detection mode is that the amount of transmitted light is “H”, as in the other detection modes, and
The amount of reflected light is “L”. Accordingly, even in the continuous paper detection mode, it is possible to determine the presence / absence of the recording paper 12a by the same determination method as in the other detection modes without causing erroneous determination.

If it is determined that there is no paper in the continuous paper detection mode, the paper type is determined based on the detection outputs of the transmissive photosensor 26 and the reflective photosensor 27. That is, in the continuous paper detection mode, the threshold of the transmissive photosensor 26 is the upper transmitted light amount threshold SH.
Since t is selected, the label 12c is detected based on the detection output of the transmission type photosensor 26 while the recording paper 12a is conveyed for the label length or longer, and if the label 12c is detected, the paper type is different. Can be determined. On the other hand, when the label 12c is not detected, the position of the black mark 12d is further detected based on the detection output of the reflective photosensor 27. Since the upper reflected light amount threshold value SHr is selected as the threshold value of the reflection type photosensor 27, the black mark 12d can be detected with certainty, the unmarked continuous paper P4 and the marked continuous paper P.
3 can be discriminated. Therefore, it is possible to accurately determine the paper type difference.

In the present embodiment, as described above, the transmissive photosensor 26 and the reflective photosensor 2 are used.
7 is used to determine the presence or absence of the recording paper 12a by performing AND determination using the detection results of the two types of sensors. At this time, the determination thresholds of the two types of sensors are set in two stages, and the print target is recorded. An appropriate combination of thresholds for determination is used according to the paper type of the paper 12a. As a result, a thin-mark continuous paper P3 or unmarked continuous paper P4 that is likely to be erroneously detected with the same threshold setting as the other recording paper 12a, or a low-reflectance mount including a transparent mount as the release mount 12b is used. The presence / absence of the recording paper 12a can be detected without causing erroneous detection of various types of paper including the label paper P1 and the labeled label paper P2 used.

The transmissive photosensor 26 is installed as a label detector for detecting each label 12c on the recording paper 12a, and the reflective photosensor 27 is a mark detector for detecting the black mark 12d. It will be installed. The two-stage threshold setting described above allows the transmissive photosensor 26 to function as a label detector when a label detector is required, and the reflective photosensor 27 as a mark detector when a mark detector is required. It is set to work. Therefore, it is possible to detect the absence of paper using a mark detector and a label detector without providing a dedicated sensor.

In the above-described embodiment, the determination threshold values of the transmission type photosensor 26 and the reflection type photosensor 27 are set in two stages, but three or more determination threshold values are set, and the sheet specifications are set. You may use properly according to.

Further, in the above-described embodiment, the detection of the absence of paper at the time of executing a print job performed when a print command or print data is received has been described. However, conveyance for cueing when the roll paper 12 is loaded, etc. Even when the recording paper 12a is transported without a printing operation, it is possible to detect the absence of paper and the type of paper by the same method. In this case, the paper type to be transported and the recording paper detection mode may be set in advance.

DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Printer main body, 3 ... Open / close lid, 4 ... Discharge port, 5 ... Discharge guide, 7 ...
Roll paper storage unit, 8 ... Platen, 9 ... Head unit frame, 10 ... Printer body frame, 12 ... Roll paper, 12a ... Recording paper, 12b ... Release sheet, 12c ... Label, 12d
DESCRIPTION OF SYMBOLS ... Black mark, 13 ... Inkjet head, 13a ... Head driver, 18 ... Platen frame, 20 ... Tension guide, 20a ... Feeding roller, 26 ... Transmission type photo sensor, 27 ... Reflection type photo sensor, 30 ... Control part, 31 ... Storage unit, 32 ... host device, A ... transport path, L1, L2, L5, L6 ... transmitted light amount, L3, L4, L7 ... reflected light amount,
P1 ... label paper, P2 ... marked label paper, P3 ... continuous paper with mark, P4 ... continuous paper without mark, SHr ... upper reflected light intensity threshold, SLr ... lower reflected light intensity threshold, SHt ... upper transmitted light intensity threshold, SLt ... Lower transmitted light amount threshold value, Sr, St ... threshold value

Claims (8)

A recording paper detection method for a printer that selectively loads recording paper of a plurality of paper types,
A reflection type photo sensor and a transmission type photo sensor are installed in the conveyance path for conveying the recording paper,
A plurality of reflected light amount threshold values used for determination of the light reception output by the reflection type photosensor are set in advance, and a plurality of transmission light amount threshold values used for determination of the light reception output by the transmission type photosensor are set in advance,
When printing or transporting the recording paper,
Before starting the printing or conveyance, set any one of the plurality of reflected light amount thresholds and one of the plurality of transmitted light amount thresholds as a determination threshold,
A recording paper detection method, comprising: detecting the presence or absence of the recording paper in the transport path or the paper type based on the determination threshold value and light reception outputs of the reflective photosensor and the transmissive photosensor. The recording paper detection method according to claim 1,
When the light reception output of the transmission photosensor is higher than the transmission light amount threshold set as the determination threshold, and the light reception output of the reflection photosensor is lower than the reflection light threshold set as the determination threshold And determining that the recording sheet is out of paper in the transport path. In the recording paper detection method according to claim 1 or 2,
The recording paper of the plurality of paper types includes a label paper in which labels are pasted at a constant interval on a long mount, and a recording paper with a mark to which marks are attached at a constant interval,
When printing or transporting the label paper, the label is detected based on the light reception output of the transmissive photosensor,
A method for detecting a recording paper, wherein when the recording paper with a mark is printed or conveyed, the mark is detected based on a light reception output of the reflective photosensor. In the recording paper detection method according to claim 3,
The recording paper of the plurality of paper types includes continuous paper having a higher transmittance than the label,
The plurality of transmitted light amount threshold values are lower than the transmitted light amount that passes through the label and lower than the transmitted light amount that passes through the mount, and the upper side that is higher than the transmitted light amount that passes through the continuous paper. Including transmitted light threshold,
When printing or transporting the label paper, the lower transmitted light amount threshold is used as the determination threshold,
A recording paper detection method, wherein when the continuous paper is printed or conveyed, the upper transmitted light amount threshold value is used as the determination threshold value. In the recording paper detection method according to claim 3 or 4,
The recording paper of the plurality of paper types includes label paper using a low reflectance mount as the mount,
The plurality of reflected light amount threshold values are higher than a reflected light amount by a mark portion of the marked recording paper and lower than a reflected light amount by a portion other than the mark of the marked recording paper, and the low reflection amount Including a lower reflected light amount threshold value lower than the reflected light amount by the rate mount,
When printing or transporting the marked recording paper, the upper reflected light amount threshold is used as the determination threshold,
A recording paper detection method, wherein when the label sheet of the low reflectance mount is printed or conveyed, the lower reflected light amount threshold value is used as the determination threshold value. A recording paper detection method for a printer that selectively loads recording paper of a plurality of paper types,
A reflection type photo sensor and a transmission type photo sensor are installed in the conveyance path for conveying the recording paper,
At least two reflected light amount threshold values used for determination of the received light output by the reflective photosensor are set in advance, and at least two transmitted light amount threshold values used for determination of the received light output by the transmissive photosensor are set in advance. ,
When printing on the recording paper or transporting the recording paper,
In addition to setting the paper type of the recording paper, any one of the plurality of reflected light amount threshold values and one of the plurality of transmitted light amount threshold values are set as determination threshold values,
A recording paper detection method, comprising: detecting the presence or absence of the recording paper in the transport path or the paper type based on the determination threshold value and light reception outputs of the reflective photosensor and the transmissive photosensor. In the recording paper detection method according to any one of claims 1 to 6,
A recording paper detection method, wherein the determination threshold value is set based on a command received from a host device before printing on the recording paper or conveyance of the recording paper is started. A printer that detects the presence or absence of the recording paper in the conveyance path by the recording paper detection method according to claim 1.

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