JP2002154244A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the forward end of a roll sheet from plunging into a platen to cause jamming. SOLUTION: In front of a print section comprising a print head 6 and a platen 7, forward end of a roll sheet 1 is detected by a line sensor 12 comprising an array 24 of detection elements arranged tightly in the widthwise direction of the roll sheet 1 and operation is controlled, based on the detection results, to start rotation of the platen 7 immediately before the forward end of the roll sheet reaches the platen 7.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for printing by sandwiching roll paper as a printing medium between a thermal head and a platen forming a printing section, and in particular, to prevent a roll paper jam in the printing section. It is related to the technology for performing.

[0001]

2. Description of the Related Art FIG. 11 is a side view showing a schematic structure of a conventional printer of this type, in which a ticket issuing printer is shown as an example. FIG. 12 is a plan view of the printer.
In the figure, reference numeral 1 denotes roll paper as a printing medium for issuing tickets.
The roll paper 1 is loaded on a rotatable loading shaft 11 of a loading section provided on the rear side of the printer 2.

A transport path 4 is provided from the loading section to a stacker 9 provided in front of the printer 2. Along the transport path 4, a separator 3, a plurality of transport rollers 5, a sensor 10, a print head 6 and a platen 7 and a cutter 8 are arranged in order. Here, thermal paper is used for the roll paper 1, and a print head 6 for printing on the roll paper 1 is used.
A thermal head having a heating element for simultaneously printing one line is used.

Further, in the transport direction of the roll paper 1, a sensor 10 disposed in front of a printing unit constituted by a print head 6 and a platen 7 is constituted by a pair of light emitting elements and a light receiving element for detecting roll paper. The roll paper 1 is provided so as to be located at the center in the width direction. The printer 2 is connected to a host device including a keyboard, a display device, a control device, and the like.

The operation of this configuration is as follows. Now, the roll paper 1 is loaded on the loading shaft 11 of the loading section, and the roll paper 1 is sandwiched between the transport rollers 5 and is sandwiched between the print head 6 and the platen 7 in the printing section. Further, it is assumed that the leading end of the roll paper 1 is located at the position of the cutter 8, and the cutter 8 is in a non-operation state.

In this state, when the operator operates the keyboard of the host device to send a ticket issuing signal to the printer together with the print data, the print head 6 prints one line on the roll paper 1. Accordingly, power from a drive source (not shown) is transmitted to the platen 7 and the transport roller 5. As a result, the roll paper 1 is fed by one line, and when the feeding is completed, printing of the next one line is performed by the print head 6, and the roll paper 1 is fed again by one line.

[0006] Such operations are repeated, and when printing is completed, the roll paper 1 is fed by a predetermined amount by rotation of the transport roller 5 and the platen, and then the roll paper 1 is cut into a fixed length by the cutter 8 and printed. The portion is discharged to the stacker 9 as a predetermined ticket. Note that the transport roller 5 is attached to the platen 7.
Power is transmitted from the drive source, or power is transmitted from the same drive source via a clutch or the like, and the platen 7 rotates independently of the transport roller 5. I have.

The print head 6 and the platen 7 are always in contact with each other. Therefore, in order to secure the life of the print head 6, the platen 7 does not rotate except during printing. By the way, when the roll paper 1 runs out, the operator newly loads the roll paper 1 on the loading shaft 11.

When the roll paper 1 is jammed in the transport path 4, the operator once puts the roll paper 1 on the loading shaft 11.
, And after removing the jam, the roll paper 1 is reloaded on the loading shaft 11. In such a case, when the operator sends a signal for instructing the setting of the roll paper 1 to the printer 2 by using the keyboard of the host device, the power of a drive source (not shown) is transmitted to the loading shaft 11 and the transport roller 5, and
And the transport roller 5 rotates.

As a result, the roll paper 1 rotates in the direction of arrow A, and the leading end of the roll paper 1 is picked up by the separator 3 and sent to the transport path 4. The roll paper 1 sent to the transport path 4 is nipped by a transport roller 5 and transported toward the printing unit by the rotation of the transport roller 5. The front end central portion of the roll paper 1 is detected by a sensor 10 before the printing unit. The rotation of the platen 7 starts immediately before the leading end of the roll paper 1 reaches the printing unit based on the detection signal.
The control is performed so that the leading end of the roll paper 1 does not collide with the platen 7 to cause a jam.

As a result, the leading end of the roll paper 1 is smoothly sandwiched between the print head 6 and the platen. Further, after the roll paper 1 is fed by a fixed amount, the leading end is cut by the cutter 8 and discharged to the stacker 9. . In this way, roll paper 1
Is completed.

[0011]

However, the above-mentioned prior art has the following problems. That is, when a new roll paper is loaded or when a jam that has occurred in the transport path is recovered, the operator manually cuts the end of the new roll paper or the roll paper to be reloaded. The tip shape hardly becomes a shape perpendicular to or close to the length direction, and is often cut into an oblique shape or the like.

Therefore, when the leading end of the roll paper is conveyed toward the printing unit, the sensor detects the center of the leading end of the roll paper just before the printing unit. If the roll paper is cut, the center of the leading edge in the width direction is detected after the leading edge of the roll paper has passed, and accurate detection is not performed. As a result, if the platen is rotated after a certain amount of roll paper is conveyed from the detection of the roll paper by the sensor, the leading edge of the roll paper may collide with the contact portion between the print head and the platen before the rotation of the platen, causing a jam. There was a problem that occurred.

An object of the present invention is to solve such a problem.

[0014]

In order to solve the above-mentioned problems, the present invention sends the leading end of a roll paper loaded in a loading section to a printing section, and holds the leading end of the roll paper between the platen and the print head by rotating the platen. In a printer that performs printing on the roll paper by the print head, a detection unit capable of detecting the roll paper over the entire width direction of the roll paper is disposed in front of the printing unit in the transport direction of the roll paper. The rotation of the platen is started immediately before the leading end of the roll paper reaches the platen by detecting the leading end of the roll paper.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a printer according to the present invention will be described below with reference to the drawings. Figure 1 shows the first
2 is a side view showing a schematic configuration of the embodiment, and FIG. 2 is a plan view of the same. As shown in this figure, in the present embodiment, a line sensor 12 is disposed as a detecting unit in front of a printing unit in the transport direction of the roll paper 1 in place of a conventional sensor including a pair of a light emitting element and a light receiving element. The line sensor 12 has an element row 13 in which a plurality of reading elements (detection elements) are densely arranged in a line in a length capable of reading the entire width of the roll paper 1. The paper 1 is provided so as to be orthogonal to the length direction.

A transport roller 5 for transporting the roll paper 1
A motor (not shown), which is a driving source for driving the disk, is provided with a disk that rotates integrally with its rotating shaft, and an encoder including a sensor that detects a slit provided on the disk. The feed amount of the roll paper 1 can be recognized according to the rotation amount of the motor to be rotated.

The other components are the same as those of the prior art, so that the same components are denoted by the same reference numerals and description thereof is omitted. Next, the operation will be described. Note that the operation of issuing a ticket is performed in the same manner as in the related art, and a description thereof will be omitted. First, the operator loads a new roll paper 1 or a roll paper 1 to be reloaded into the loading shaft 11 at the time of paper out or jam recovery processing, and then sends a signal to the printer 2 to instruct the setting of the roll paper 1 from the keyboard of the host device. And loading shaft 1
The power of a drive source (not shown) is transmitted to the transfer roller 1 and the transport roller 5, and the loading shaft 11 and the transport roller 5 rotate.

As a result, the roll paper 1 rotates in the direction of arrow A, and the leading end of the roll paper 1 is picked up by the separator 3 and sent to the transport path 4. The roll paper 1 sent to the transport path 4 is nipped by the transport roller 5 and transported toward the printing unit by the rotation of the transport roller 5, but the front end of the roll paper 1 is detected by the line sensor 12 just before the printing unit. Is performed.

FIG. 3 shows the roll paper 1 by the line sensor 12.
FIG. 4 is a plan view showing the detection of the leading end of FIG. When the leading end of the roll paper 1 is cut obliquely as shown in this figure, the leading end is detected by an unspecified reading element of the element array 13 of the line sensor 12. Therefore, after the leading edge of the roll paper 1 is detected in this way, a specific reading element of the element array 13, for example, A
The output signal from an encoder (not shown) provided in the driving source of the transport roller 5 is counted until the reading element at the distance of the roll paper 1 detects the roll paper 1 and the leading edge of the roll paper 1 is determined based on the count value. , A length B from the position to the detection position of the specific reading element is calculated.

As a result, since the leading edge position of the roll paper 1 in the distance from the line sensor 12 to the printing unit can be recognized, the leading edge of the roll paper 1 immediately before reaching the printing unit based on the output signal signal from the encoder. To platen 7
Start rotation. Here, the leading end of the roll paper 1 is smoothly sandwiched between the print head 6 and the platen. Further, the roll paper 1 is fed by a fixed amount and then cut by the cutter 8.

In this case, since the length B is known, a length obtained by adding a predetermined length to this length B passes through the cutter 8, and then the cutting is performed so that the leading end of the roll paper 1 is long. Can be cut at right angles to the vertical direction. The cut portion is discharged to the stacker 9, and the roll paper 1
Is completed.

According to the first embodiment described above,
The leading edge of the roll paper is detected by a line sensor before the printing unit, the length from the leading edge of the roll paper to a certain position is calculated, and based on the calculation result, immediately before the leading edge of the roll paper reaches the printing unit. The start of the rotation of the platen prevents the leading end of the roll paper from entering the platen and causing a jam even if the leading end shape of the roll paper is not constant when the roll paper is loaded or reloaded. The effect is obtained.

FIG. 4 is a side view showing a schematic configuration of the second embodiment, and FIG. 5 is a plan view. In the second embodiment, instead of the line sensor 12 of the first embodiment,
A plurality of optical sensors 14 each including a light emitting element and a light receiving element pair are arranged as detecting means, and the optical sensors 14 are arranged in a line in a width direction of the roll paper 1, that is, a direction orthogonal to a length direction of the roll paper 1. Have been.

In the second embodiment, after loading or reloading of the roll paper 1,
Is detected by the optical sensor 14 when the leading edge of the roll paper 1 is conveyed, and the ON signal at that time is used as a trigger to control the rotation of the platen 7 immediately before the leading edge of the roll paper 1 reaches the printing section. It is. In this case, a position where any one of the optical sensors 14 arranged in one row detects the roll paper 1 and is turned on is set as the forefront of the roll paper 1 and the first position is determined.
Similarly to the embodiment, the output signal from an encoder (not shown) is counted, and the platen 7 is counted based on the counted value.
The timing of the start of the rotation is obtained.

According to the above-described second embodiment, the effect of preventing the jam of the roll paper can be obtained similarly to the first embodiment, and a plurality of optical sensors can be used instead of the line sensor. An effect that can be realized at low cost can also be expected. FIG. 6 is a side view showing a schematic configuration of the third embodiment, and FIG. 7 is a plan view of the same. In the third embodiment,
An application that reads an application form and applies the ticket to a printer that issues tickets for vehicles, various events, etc., and inserts and ejects an application form such as a mark sheet below the stacker 9 at the front of the apparatus as shown in the figure. An outlet 18 is provided,
From the insertion / ejection port 18 to the inside of the apparatus,
A reading device (OMR) 20 for reading a mark written on the application form is arranged in the middle of the transport path 16, and the read application form is temporarily held at the end of the transport path 16. A temporary storage unit 19 is provided.

A loading shaft 11, on which the roll paper 1 is set, a separator 3, a transport path 4, a transport roller 5, a print head 6 and a platen 7, a cutter 8, a stacker 9, and a sensor 10, which constitute a printing section, are provided in the same manner as in the prior art. The transport path 4 and the transport path 16 are connected by a transport path 21, and a blade 17 for switching the feed direction is arranged at a junction of the transport path 4 and the transport path 21.

Further, in this embodiment, a detecting means 22 using a switch or a sensor for detecting the attachment / detachment of the roll paper 1 to / from the loading shaft 11 is provided. In the case of issuing a ticket from the printer 2 in this configuration, when an operator inserts an application filled in by a user (ticket purchaser) into the insertion / ejection port 18, the application is transported through the transport path 16 and read by the reader 20. The contents written in are read.

Thereafter, the application form is sent to the temporary storage section 19 and temporarily stored. In parallel with this temporary storage operation or after the temporary storage, data corresponding to the contents of the application form is recorded on the roll paper 1 by the print head 6. After the printing, the roll paper 1 is cut by the cutter 8 and discharged to the stacker 9 as a ticket. After discharging the ticket, the application is discharged from the insertion / discharge port 18.

In such a printer 2, when the operator loads a new roll paper 1 or a roll paper 1 to be reloaded into the loading shaft 11 at the time of paper out or jam recovery processing, the attachment / detachment of the roll paper 1 at this time is detected by the detecting means 22. Is detected by The power of a drive source (not shown) is transmitted to the loading shaft 11 and the transport roller 5 by using the detection signal of the detection unit 22 as a trigger, and the loading shaft 11 and the transport roller 5 rotate.

As a result, the roll paper 1 rotates in the direction of arrow A, and the leading end of the roll paper 1 is picked up by the separator 0 and sent to the transport path 4. The roll paper 1 sent to the transport path 4 is nipped by a transport roller 5 and transported by the rotation of the transport roller 5.
7, the leading edge of the roll paper 1 is sent from the transport path 16 to the transport path 16 through the transport path 21, and the reader 20 detects the leading edge of the roll paper 1.

FIG. 8 shows a roll paper 1 by the reading device 20.
FIG. 4 is a plan view showing the detection of the leading end of FIG. As shown in this figure, the reading device 20 has a reading sensor 23 similar to a line sensor, and has an element row 24 in which a plurality of reading elements are arranged in a row so as to be capable of reading the entire width of the roll paper 1. ing. Further, it is assumed that the sensor 10 is disposed on the transport path 4 so as to be at the same position as the setting reading element located at a distance C from the end of the element row 24.

Therefore, assuming that the leading end of the roll paper 1 is cut obliquely as in the first embodiment, the leading end is detected by an unspecified reading element in the element array 24. After the leading edge of the roll paper 1 is detected and before the setting reading element detects the roll paper 1, an output signal from an encoder (not shown) provided in the drive source of the transport roller 5 is counted. The length D from the leading edge of the roll paper 1 to the detection position of the setting reading element is calculated based on the value, and the calculated length D is stored in a memory (not shown) provided in the printer 2. Remember.

Thereafter, the loading shaft 11 and the transport roller 5 are rotated in the reverse direction to take up the roll paper 1 so that the roll paper 1
Is returned to the transport path 4, and then the roll paper 1 is transported toward the printing unit by rotating the loading shaft 11 and the transport roller 5. The portion detected by the setting reading element in front of the printing unit by this conveyance is detected by the sensor 10, so that the roll paper 1 at the distance from the sensor 10 to the printing unit based on the length D stored in the memory.
And the rotation of the platen 7 is started immediately before the leading edge of the roll paper 1 reaches the printing section based on the output signal signal from the encoder.

As a result, the leading end of the roll paper 1 is smoothly sandwiched between the print head 6 and the platen. Further, the roll paper 1 is fed by a fixed amount and then cut by the cutter 8. In this case, since the length D is known, a length obtained by adding a predetermined length to the length D passes through the cutter 8, and then the cutting is performed so that the leading end of the roll paper 1 is in the length direction. It can be cut at a right angle to it.

The cut portion is discharged to the stacker 9, whereby the setting of the roll paper 1 is completed. According to the third embodiment described above, when a reading device for reading an application form is provided, the leading end of the roll paper is detected from the leading edge of the roll paper to a certain position by using the reading device to detect the leading end of the roll paper. Is calculated, and based on the calculation result, the rotation of the platen is started immediately before the leading edge of the roll paper reaches the printing unit, so that the occurrence of a jam like the first embodiment is reduced. The effect that it can be prevented is obtained.

FIG. 9 is a side view showing a schematic configuration of the fourth embodiment, and FIG. 10 is a plan view of the same. In the fourth embodiment, in addition to the configuration of the third embodiment, a manual cutter 25 is provided at the insertion / ejection port 18 of the application form. The operation of this configuration will be described. When the operator loads a new roll paper 1 or a roll paper 1 to be reloaded into the loading shaft 11 at the time of paper out or jam recovery processing, the attachment / detachment of the roll paper 1 at this time is detected by the detecting means 22. Is done.

The power of a drive source (not shown) is transmitted to the loading shaft 11 and the transport roller 5 by using the detection signal of the detection means 22 as a trigger, and the loading shaft 11 and the transport roller 5 rotate. As a result, the roll paper 1 rotates in the direction of arrow A, and the leading end of the roll paper 1 is picked up by the separator 3 and sent to the transport path 4. The roll paper 1 sent to the transport path 4 is nipped by the transport roller 5 and transported by the rotation of the transport roller 5, and at this time, the blade 17 is switched, whereby the leading end of the roll paper 1 is moved from the transport path 16. The paper is sent to the conveyance path 16 through the conveyance path 21, and the leading edge of the roll paper 1 is detected by the reading sensor 23 of the reading device 20.

Based on the detection signal at this time, the transport of the roll paper 1 is controlled such that the leading end of the roll paper 1 projects from the insertion / ejection port 18 by a certain length and then stops. In this case, control is performed by using a detection signal when the reading sensor 23 detects the leading edge of the roll paper 1 as a trigger and counting output signals from an encoder (not shown) provided in the drive source of the transport roller 5. Is performed based on the transport amount of the roll paper 1 obtained from the count value.

After stopping, the operator cuts the leading end of the roll paper 1 by cutting the leading end of the roll paper 1 with the cutter 25, and after the cutting, rotates the loading shaft 11 and the transport roller 5 in the reverse direction to take up the roll paper 1. Then, the leading end is detected by the reading sensor 23 of the reading device 20. At this time, if each reading element of the reading sensor 23 detects the leading end of the roll paper 1 at the same time, it is determined that the leading end of the roll paper 1 is cut at a right angle to the longitudinal direction, and each reading element is At the same time, when the leading end of the roll paper 1 is not detected, it is determined that the roll paper 1 has been cut into an improper shape such as oblique.

In the case of an improper shape, the roll paper 1 is conveyed so that the leading end projects again from the insertion / ejection port 18 by a certain length and then stops, and the operator cuts the leading end of the roll paper 1 with the cutter 25. Thereafter, the leading end of the roll paper 1 is returned, and detection by the reading sensor 23 is performed. If it is determined by the detection by the reading sensor 23 that the roll paper 1 has been cut into an appropriate shape,
Then, the blade 17 is switched to convey the roll paper 1 toward the printing unit.

By this transport, the roll paper 1 is located just before the printing section.
Is detected by the sensor 10, the rotation of the platen 7 is started immediately before the leading edge of the roll paper 1 reaches the printing section based on the detection signal. As a result, the leading end of the roll paper 1 is smoothly sandwiched between the print head 6 and the platen, and the setting of the roll paper 1 is completed by further transporting the roll paper 1 until the leading end reaches the cutter 8.

In the above-described fourth embodiment, a cutter is provided at the insertion / ejection port of the application form, the leading end of the roll paper is cut by the cutter by the cutter, and the leading end shape after the cut is examined to determine an inappropriate shape. If so, cut the tip of the roll paper again with a cutter to adjust the shape, and then start the rotation of the platen just before the leading edge of the roll paper reaches the printing section, so that the jam more reliably The effect that generation can be prevented is obtained.

Incidentally, in the above-described fourth embodiment,
If the operator appropriately cuts the leading end of the roll paper 1 with the cutter 25, the leading end shape becomes an appropriate shape. Therefore, after cutting, the roll paper 1 is returned to the transport path 4 without detecting the leading end of the roll paper 1 by the reading sensor 23. Alternatively, the operation may be shifted to the operation of transporting the sheet to the printing section. In this case, the control becomes easy and the operation time is shortened.

Although the embodiments have been described above, the present invention is not limited to these embodiments. For example, in the above-described first and second embodiments, after the roll paper 1 is loaded or reloaded, the roll paper 1 is conveyed and the leading edge is detected by an instruction to the operator, and the roll paper 1 is set. However, when the first printing is performed after the loading or reloading of the roll paper 1, the transport of the roll paper 1 and the leading edge detection may be performed by using the print instruction as a trigger, and the roll paper 1 may be set.

In the third and fourth embodiments, the leading end of the roll paper 1 is detected by using the detection signal of the detecting means 22 for detecting the attachment / detachment of the roll paper 1 as a trigger, and the roll paper 1 is set. However, when the detecting unit 22 detects the attachment / detachment of the roll paper 1, the data is stored in a storage unit (not shown), and thereafter, when the first printing is performed,
The print instruction may be used as a trigger to convey the roll paper 1 and detect the leading end, and then set the roll paper 1.

Further, in each of the above-described embodiments, a printer that performs printing on roll paper 1 has been described. However, any printer other than roll paper that performs printing using a platen can be applied.

[0047]

As described above, according to the present invention,
Even if the leading edge of the roll paper is not constant at the time of loading or reloading the roll paper, the platen can be started to rotate just before the leading edge of the roll paper reaches the printing section. To prevent the occurrence of a jam due to the intrusion.

[Brief description of the drawings]

FIG. 1 is a side view showing a schematic configuration of a first embodiment.

FIG. 2 is a plan view of the first embodiment.

FIG. 3 is a plan view showing the detection of the leading end of roll paper by a line sensor.

FIG. 4 is a side view showing a schematic configuration of a second embodiment.

FIG. 5 is a plan view of the second embodiment.

FIG. 6 is a side view showing a schematic configuration of a third embodiment.

FIG. 7 is a plan view of the third embodiment.

FIG. 8 is a plan view showing detection of the leading end of roll paper by a reading sensor.

FIG. 9 is a side view showing a schematic configuration of a fourth embodiment.

FIG. 10 is a plan view of a fourth embodiment.

FIG. 11 is a side view showing a schematic configuration of a conventional technique.

FIG. 12 is a plan view of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roll paper 2 Printer 3 Separator 4 Transport path 5 Transport roller 6 Print head 7 Platen 8 Cutter 9 Stacker 10 Sensor 11 Loading axis 12 Line sensor 13 Element row 14 Optical sensor 16 Transport path 17 Blade 18 Insertion discharge port 19 Temporary storage section 20 Reading device 21 Conveying path 22 Detecting means 23 Reading sensor 24 Element array 25 Cutter

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takeshi Kaneko 1-7-12 Toranomon, Minato-ku, Tokyo Inside Oki Electric Industry Co., Ltd. (72) Inventor Ryuji Ishii 3-1 Futaba-cho, Takasaki-shi, Gunma F-term (reference) 2C058 AB16 AC06 AE04 AF20 AF31 AF51 GA14 GB05 GB09 GB13 GB31 GB43 GB47 LA03 LB06 LB17 LB35 LC11 LC22 LC25 2C060 BA01 BC02 BC03 BC12 BC15 BC84 3F103 AA02 BA04

Claims (7)

[Claims] 1. A leading end of a roll paper loaded in a loading section is sent to a printing section, and the leading end is interposed between the platen and the print head by rotation of a platen, and the print head prints on the roll paper. In the printer performing, a detection means capable of detecting the roll paper over the entire width direction of the roll paper is disposed in front of the printing unit in the roll paper conveyance direction, and the detection means detects the leading end of the roll paper, A printer, wherein the rotation of the platen is started immediately before the leading edge of the roll paper reaches the platen. 2. The printer according to claim 1, wherein a line sensor having an element array including detection elements densely arranged in the width direction of the roll paper is used as the detection means. 3. The printer according to claim 1, wherein an optical sensor comprising a light emitting element and a light receiving element arranged in a line in the width direction of the roll paper is used as the detecting means. 4. The length according to claim 2, wherein after the roll paper is loaded, the length of time from when an unspecified detection element in an element array detects the leading end of the roll paper to when a specific detection element detects the roll paper. A printer that cuts the leading end of the roll paper with a cutter provided in front of the printing unit in the roll paper transport direction based on the calculated length. 5. An application in which the leading end of the roll paper loaded in the loading section is sent to the printing section, and the leading end is sandwiched between the platen and the print head by the rotation of the platen, and the roll paper is inserted from the insertion / ejection port. A printer that reads the written contents of a book with a read sensor and prints on the roll paper by the print head based on the read content, wherein the read sensor has an element row that can detect the roll paper over the entire width direction, Before the printing unit in the transport direction of the roll paper,
Along with arranging a detection sensor to correspond to a specific element of the element row in the width direction of the roll paper,
A conveyance path is provided so that the leading end of the roll paper can be guided to the reading sensor side before the detection sensor. After loading the roll paper, the leading end is sent to the reading sensor, and the leading edge of the roll paper is After calculating the length from the detection of an unspecified element in the element row to the detection of the roll paper by the specific element, the roll paper is returned to the printing section after returning the leading end thereof. The position of the leading edge of the roll paper is recognized by detecting the portion of the roll paper detected by the specific element by the detection sensor, and the position of the platen is detected immediately before the leading edge of the roll paper reaches the platen. A printer for starting rotation. 6. An application in which the leading end of the roll paper loaded in the loading section is sent to the printing section, and the leading end is sandwiched between the platen and the print head by the rotation of the platen, and the roll paper is inserted through the insertion / ejection port. In a printer that reads the written contents of a book with a read sensor and prints on the roll paper by the print head based on the read content, the read sensor has an element row that can detect roll paper over the entire width direction, A detection sensor is arranged in front of the printing unit in the roll paper conveyance direction, and a conveyance path is provided so that the leading end of the roll paper can be guided to the reading sensor side before the detection sensor. A cutter is provided at the discharge port, and after loading the roll paper, the leading edge is sent to the reading sensor to check the leading edge of the roll paper. Out, and based on the detection result, project the leading end of the roll paper from the insertion / ejection port by a predetermined length, cut the projected portion with the cutter, and then move the leading end of the roll paper to the reading sensor. By returning it and detecting the leading edge, it is determined whether or not the leading edge is perpendicular to the length direction of the roll paper. If the leading edge is not perpendicular, the roll is cut again by the cutter. A printer, wherein the leading end is returned and then sent to a printing unit. At that time, the detection sensor detects the leading end of the roll paper, and starts rotating the platen immediately before the leading end reaches the platen. 7. An application in which the leading end of the roll paper loaded in the loading section is sent to the printing section, and the leading end of the roll paper is sandwiched between the platen and the print head by rotation of the platen, and is inserted from the insertion / ejection port. A printer that reads the written contents of a book with a read sensor and prints on the roll paper by the print head based on the read content, wherein the read sensor has an element row that can detect the roll paper over the entire width direction, A detection sensor is arranged in front of the printing unit in the roll paper conveyance direction, and a conveyance path is provided so that the leading end of the roll paper can be guided to the reading sensor side before the detection sensor. A cutter is provided at the discharge port, and after loading the roll paper, the leading edge is sent to the reading sensor to check the leading edge of the roll paper. And, based on the detection result, protrude the leading end of the roll paper from the insertion / ejection port by a predetermined length, cut the protruding portion with the cutter, return the leading end of the roll paper, and then perform printing. Wherein the detection sensor detects the leading end of the roll paper and starts rotating the platen immediately before the leading end reaches the platen.