JP2011201224A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of high quality printing by preventing paper float in a printing section, thereby maintaining satisfactory flatness, while minimizing a cost increase.SOLUTION: The printer 1 includes a platen 26 having a platen surface 26a facing an ink jet head 21; a main feed roller 36 provided upstream of the platen 26 in the direction of conveyance of a roll of paper 11, and adapted to convey the roll of paper 11 facing the platen surface 26a while sandwiching the roll of paper 11; and a front feed roller 37 disposed downstream of the platen 26 in the direction of conveyance of the roll of paper 11, and adapted to eject the roll of paper 11 from the platen surface 26a while sandwiching the roll of paper 11. The platen surface 26a is disposed at the side of the ink jet 21 with respect to a plane C including the position A where the roll of paper 11 is sandwiched using the main feed roller 36 and the position B where the roll of paper 11 is sandwiched using the front feed roller 37.

Description

  The present invention relates to a printer that performs printing on a sheet to be conveyed.

As a printer for preventing paper floating, a printer that includes a pressing unit that presses a medium that has passed through a pair of conveyance rollers that sandwich the medium and convey it from the supply side onto the processing reference surface is directed toward the processing reference surface. (For example, refer to Patent Document 1). In this printer, when the sheet-like medium is sandwiched by the conveyance roller pair and conveyed toward the processing reference surface of the processing unit, the pressing unit presses the medium toward the processing reference surface. The lift of the medium can be prevented.

Also, there are those equipped with a suction device for adsorbing the medium to the platen, and those that wrap around the charging belt between the driving roller and the driven roller and charge the surface of the charging belt with the charging roller to adsorb the medium It is known (see, for example, Patent Documents 2 and 3).

JP 2008-132628 A JP 2008-114409 A Japanese Patent Laid-Open No. 7-53082

However, as in the technique of Patent Document 1, even if the paper is pressed against the platen surface by the pressing portion to suppress the floating of the paper, the fine wrinkles of the paper cannot be suppressed on the platen surface, and the paper flatness is ensured. Therefore, it has been difficult to improve the printing image quality.
In addition, in the techniques of Patent Documents 2 and 3 in which a sheet is sucked or adsorbed by static electricity, a complicated suction mechanism or electrostatic transport mechanism is required, resulting in an increase in cost.

An object of the present invention is to provide a printer capable of performing high-quality printing while preventing a paper floating in a print processing unit and maintaining good flatness while suppressing cost increase as much as possible.

A printer according to the present invention that can solve the above problems includes a print head that performs a printing process,
A platen having a platen surface facing the print head;
A conveyance roller that is provided upstream of the platen in the sheet conveyance direction and conveys the sheet while nipping it toward the platen surface;
A printer provided with a paper discharge roller that is provided on the downstream side of the platen in the paper conveyance direction and discharges paper while nipping from the platen surface;
The platen surface is disposed on the print head side with respect to a plane including a position where the paper is nipped by the transport roller and a position where the paper is nipped by the paper discharge roller.

According to this configuration, since the platen surface of the platen is on the print head side with respect to the position where the paper is nipped by the transport roller and the paper discharge roller, the paper is always pressed against the platen surface to be in a good contact state. Flatness can be ensured. In other words, compared with a structure in which roll paper is closely attached to the platen surface of the platen with separate parts and mechanisms, the paper is prevented from floating while maintaining high flatness while minimizing cost increase. Can print to quality.

In the printer of the present invention, it is preferable that the paper transport speed of the paper discharge roller is set to be faster than the paper transport speed of the transport roller.
According to this configuration, an appropriate tension can be applied to the paper on the platen, and the flatness can be improved by further improving the adhesion of the paper to the platen surface.

In the printer according to the aspect of the invention, it is preferable that the print head is an inkjet head that ejects ink.
When printing with an inkjet head, the print quality is likely to change depending on the paper flatness. According to this configuration, the ink ejected from the inkjet head can be evenly adhered to the paper disposed on the platen surface with good flatness, and high-quality printing processing can be performed.

1 is an external perspective view of an ink jet printer that is an embodiment of a printer according to the present invention. FIG. 2 is a side view of the printer of FIG. 1 with a printer case removed. FIG. 2 is a schematic side view of a transport mechanism for explaining a schematic configuration of a transport mechanism of the printer of FIG. 1. FIG. 2 is a side view of the vicinity of a print processing unit of the printer of FIG. 1. FIG. 2 is a schematic side view illustrating a roll paper conveyance state in the vicinity of a print processing unit of the printer of FIG. 1.

Hereinafter, an example of an embodiment of a printer according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, an ink jet printer (printer) 1 uses a plurality of types of color inks to perform color printing on a part of a rolled paper roll, and is centered on the front surface of a printer case 2 that covers the printer body. A roll paper cover 3 is provided so as to be freely opened and closed. An ink cartridge insertion port 8 is provided on the side of the roll paper cover 3, and the ink cartridge 4 is inserted and accommodated therein. Further, on the front surface of the printer case 2, a power switch 5, a feed switch 6, an indicator 7, and the like are also arranged.

As shown in FIG. 2, a roll paper (paper) 11 that is a medium to be printed is a roll paper storage unit 1.
2, when the roll paper cover 3 is opened, the roll paper storage unit 12 containing the roll paper 11 is opened, and the roll paper 11 can be replaced.

The roll paper cover 3 can be rotated to the near side with its lower end as a center. On the upper side of the roll paper cover 3, a paper discharge unit 9 for discharging the printed roll paper is provided on the front side, and an opening / closing slider 10 slidable on the front side is provided on the front end of the paper discharge unit 9. It is done.

When a finger is placed on the open / close slider 10 and pulled forward, the open / close slider 10 moves forward and the lock is released. In this state, when the opening / closing slider 10 is further pulled forward, the roll paper cover 3 is rotated and opened around the lower end, and the roll paper storage portion 12 provided at the back of the roll paper cover 3 is opened.
Is exposed, and roll paper can be loaded into the roll paper storage unit 12.

As shown in FIG. 3, a feed roller 34 that feeds the roll paper 11 stored in the roll paper storage unit 12 into a sheet shape is provided at the upper rear portion of the roll paper storage unit 12. A roll paper supply device 39 that feeds the roll paper 11 in a sheet form from the roll paper storage unit 12 and the feed roller 34 is configured.

On the downstream side of the feed roller 34, a main feed roller (transport roller) 36 that sandwiches and transports the roll paper 11 is provided. Further, in the conveyance path from the feed roller 34 to the main feed roller 36, the tension urged rearward of the apparatus by an urging member (not shown) so as to keep the tension of the roll paper 11 with respect to the main feed roller 36 constant. A roller 35 is provided.

Further, on the downstream side of the main feed roller 36, a front feed roller (paper discharge roller) 37 that sandwiches and conveys the roll paper 11 is provided, and a platen between the main feed roller 36 and the front feed roller 37 is provided. 26 is provided. Further, the paper discharge unit 9 is provided with a cutter 38 for cutting the printed roll paper 11.

The roll paper 11 is pulled out from the roll paper storage unit 12 and is fed out by a feed roller 34, a tension roller 35, a main feed roller 36, a platen 26, and a front feed roller 37.
Then, the paper is discharged from the paper discharge unit 9.

The feeding roller 34 generates a paper feeding force that draws the roll paper 11 stored in the roll paper storage unit 12 into a sheet shape. The main feed roller 36 is rotationally controlled with high accuracy, and conveys the roll paper 11 at a high accuracy paper feed pitch. The tension roller 35 stabilizes the paper feed accuracy by keeping the load applied to the main feed roller 36 constant, and realizes high-speed feed by holding a certain amount of slack of the roll paper 11.

Further, the front feed roller 37 feeds the sheet-shaped roll paper 11 to the paper discharge unit 9 while holding the roll paper 11 with a sufficient holding force. As a result, for example, even when the roll paper 11 that has been printed and discharged on the paper discharge unit 9 is pulled out, paper floating on the platen 26 is prevented, and printing can be performed satisfactorily without jamming caused by paper floating thereafter. Is done.

The front feed roller 37 is set so that the paper transport speed is faster than the main feed roller 36. Thus, the main feed roller 36 and the front feed roller 37
In the meantime, the roll paper 11 is in a state where a predetermined tension is applied, and is prevented from being lifted on the upper surface of the platen 26 and is prevented from adhering to the inkjet head 21.

4 and 5, a virtual plane C including a position A where the roll paper 11 is sandwiched by the main feed roller 36 and a position B where the roll paper 11 is sandwiched by the front feed roller 37. The platen surface 26a formed from the upper surface of the platen 26 is disposed on the inkjet head 21 side.
As a result, the roll paper 11, which is always tensioned between the main feed roller 36 and the front feed roller 37, is always pressed against the platen surface 26 a of the platen 26 and is in close contact with the lower side of the inkjet head 21. Thus, good flatness is ensured.

Further, the main feed roller 36 arranged on the upper side is arranged at a position where the central axis is shifted to the downstream side in the transport direction of the roll paper 11 with respect to the central axis of the main feed roller 36 arranged on the lower side. Has been. Accordingly, the roll paper 11 that is nipped and conveyed by the main feed roller 36 is fed downward toward the platen 26. That is, since the roll paper 11 is conveyed in the direction in which it is pressed against the platen surface 26a of the platen 26, the adhesion to the platen surface 26a is further improved.

As shown in FIG. 5, corner portions 26b are formed in the width direction at the end portion of the platen surface 26a on the main feed roller 36 side and the end portion on the front feed roller 37 side.
Thereby, as for the roll paper 11 on the platen surface 26a, the flatness between the corner portions 26b is effectively improved.

As shown in FIG. 2, an inkjet head (print head) 2 constituting a print processing unit of the inkjet printer 1 is disposed above the roll paper storage unit 12 in the printer case 2.
1 is provided. The carriage 22 is supported by a guide member 23 extending along the width direction of the roll paper 11 so as to be movable in the paper width direction.
An endless belt (not shown) extending in the width direction of the roll paper 11 and a carriage motor (not shown) that drives the endless belt can reciprocate above the platen 26 in the width direction of the roll paper 11. . A flexible ink tube 27 connected to the ink cartridge is connected to the carriage 22, and ink is supplied from the ink cartridge 4 to the inkjet head 21 of the carriage 22 through the ink tube 27.

One side in the width direction of the inkjet printer 1 is a standby position (home position) of the carriage 22 that reciprocates. Below this standby position, an ink suction mechanism (not shown) for sucking ink in each ink nozzle of the inkjet head 21 exposed on the lower surface of the carriage 22 is provided.

In the above-described ink jet printer 1, printing processing is performed by ejecting ink to a part of the roll paper 11 that is fed out from the ink jet head 21 of the carriage 22 that reciprocates.

With respect to a plane C including a position A where the roll paper 11 is clamped by the main feed roller 36 and a position B where the roll paper 11 is clamped by the front feed roller 37, the platen 26
A platen surface 26a comprising the upper surface of the ink jet head 21 is disposed on the ink jet head 21 side. As a result, the roll paper 11 is always pressed against and in close contact with the platen surface 26 a of the platen 26, and good flatness is secured on the lower side of the inkjet head 21. Therefore, the ink ejected from the inkjet head 21 can be evenly adhered to the roll paper 11 disposed on the platen surface 26a with good flatness.

That is, according to the ink jet printer 1 of the above-described embodiment, the print processing unit is suppressed while minimizing the cost increase as compared with the structure in which the roll paper 11 is brought into close contact with the platen 26 by providing a complicated suction mechanism or electrostatic conveyance mechanism. Can prevent the roll paper 11 from being lifted to maintain good flatness and can perform printing with extremely high quality.

In particular, since the transport speed of the roll paper 11 by the front feed roller 37 is set to be faster than the transport speed of the roll paper 11 by the main feed roller 36, an appropriate tension can always be applied to the roll paper 11 on the platen 26. It is possible to improve the flatness by further improving the adhesion of the roll paper 11 to the platen surface 26a.

In the above-described embodiment, a film, a cloth, a thin metal plate, or the like may be used as the medium that is the printing medium.

The ink jet printer according to the above-described embodiment may have a part of functions or mechanisms respectively included in a computer main body, a display device such as a CRT, an input device, a flexible disk drive device, and a CD-ROM drive device. For example, the printer has an image processing unit that performs image processing, a display unit that performs various displays, and a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. Also good.

If the computer system includes a printer, a computer main body, a display device such as a CRT, an input device such as a mouse or a keyboard, a flexible drive device, and a CD-ROM drive device according to this embodiment, the entire system is more than the conventional system. An excellent system.

In each of the above embodiments, a color inkjet printer that performs a printing process by ejecting ink from the inkjet head 21 is used as a printing apparatus. However, the printing apparatus is not limited to this as long as the printing apparatus can perform a printing process on paper. For example, you may apply to a monochrome inkjet printer, a laser printer, a thermal printer, a facsimile, etc.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer (printer), 11 ... Roll paper (paper), 21 ... Inkjet head (printing head), 26 ... Platen, 26a ... Platen surface, 36 ... Main feed roller (conveyance roller), 37 ... Front feed roller ( (Eject roller)

Claims (3)

A print head for performing the printing process;
A platen having a platen surface facing the print head;
A conveyance roller that is provided upstream of the platen in the sheet conveyance direction and conveys the sheet while nipping it toward the platen surface;
A printer provided with a paper discharge roller that is provided on the downstream side of the platen in the paper conveyance direction and discharges paper while nipping from the platen surface;
The printer according to claim 1, wherein the platen surface is disposed on the print head side with respect to a plane including a position where the paper is nipped by the transport roller and a position where the paper is nipped by the paper discharge roller. The printer according to claim 1,
A printer, wherein the paper transport speed of the paper discharge roller is set to be faster than the paper transport speed of the transport roller. The printer according to claim 1 or 2,
A printer, wherein the print head is an inkjet head that ejects ink.

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