JPH05443U - Ink jet printer - Google Patents

Abstract

(57) [Abstract] [Purpose] To ensure that printing can be performed from the leading edge of printing paper, and to prevent the paper support and the inside of the device from being contaminated during printing. [Structure] A pair of first and second feed rollers 8 and 9 are arranged on the upstream side and the downstream side of a paper path 2 with an inkjet head 6 in between. Inkjet head 6
The sheet support 7 is disposed at a position facing the sheet support 7. An opening 10 is formed in the paper support 7, and a sensor 11 is arranged at a position corresponding to the opening 10 so as to face the paper path 2.
Then, after the printing paper 1 is fed between the first feed rollers 8, after the sensor 11 detects that the leading edge of the paper 1 has passed between the first feed rollers 8, the inkjet head 6 is operated. ..

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an ink jet printer that prints on paper by an inkjet head.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, there is an inkjet printer as shown in FIG. 2, for example. In this inkjet printer, a pair of first and second feed rollers 28 and 29 are provided upstream and downstream of the paper path 22 across an inkjet head 26 for printing image information on the printing paper 21. Are arranged respectively, and a sensor 30 for detecting the presence or absence of the printing paper 21 is provided on the upstream side of the first feed roller 28. A paper support 27 is arranged at a position facing the inkjet head 26. Then, a large number of printing sheets 21 stacked in the sheet feeding cassette 23 are picked up one by one by the sheet feeding roller 24, the leading edge of the printing sheet 21 is detected by the sensor 30, and then the first feeding is performed. When the roller 28 is rotated by a predetermined amount, that is, the printing paper 21 is fed by a predetermined amount and faces the nozzle of the inkjet head 26, the inkjet head 26 is operated and printing is performed.

[0003]

[Problems to be solved by the device]

 However, as shown in FIG. 2, even when the sensor 30 detects the leading edge of the printing paper 21 picked up by the paper feed roller 24, the printing paper 21 is not fed between the first feed rollers 28 and the paper is not fed. The printing paper 21 may not reach between the ink jet head 26 and the paper support 27 due to a jam or the like. Even if the printing paper 21 is not fed between the inkjet head 26 and the paper support 27, when the first feed roller 28 is rotated by a predetermined amount, the inkjet head 26 is activated, and therefore the same head is used. The paper support 27 and the inside of the apparatus, which are arranged so as to face 26, are contaminated with ink. Then, there is a problem that the printing paper 21 to be sent next time is also soiled due to the soiling of the paper support 27 and the inside of the apparatus.

In order to solve this problem, another sensor 31 is provided on the downstream side of the second feeding roller 29 as shown by a chain line in FIG. 2, and after the leading edge of the printing paper 21 is detected by the sensor 31. Although it may be possible to operate the inkjet head 26, in this case, when the front end of the printing paper 21 reaches the sensor 31, the front part of the printing paper 21 has already passed the inkjet head 26 largely. Therefore, there is a problem that a large blank area where image information is not printed is formed on the front portion of the printing paper 21.

The present invention has been made in order to solve the above problems, and an object thereof is to prevent the paper support and the inside of the apparatus from being contaminated during printing, and to provide a large print on the front part of the printing paper. An object is to provide an inkjet printer in which an unprintable area is not formed.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the present invention, a printing paper is fed by a feed roller so as to pass over a paper support, and image information is printed on the printing paper by an ink jet head on the paper support. In the inkjet printer thus configured, a sensor is provided between the feed roller and the inkjet head to detect the leading edge of the printing paper fed from the feed roller and output an operation command of the inkjet head. It is a thing.

[0007]

[Action]

 Therefore, according to the present invention, when the printing paper is fed onto the paper support by the feeding roller and the leading edge of the paper is detected by the sensor, the inkjet head is activated, so that the printing by the inkjet head is performed. It is done reliably on the paper, there is no need to move the print paper too much, and there is no large unprintable area formed at the front of the print paper.

[0008]

【Example】

 An embodiment of an ink jet printer embodying the present invention will be described below with reference to the drawings. As shown in FIG. 1, a path 2 for printing paper 1 is formed in the apparatus, and a paper feed cassette 3 for stacking a large number of printing papers 1 is arranged upstream of the paper path 2. The paper feed roller 4 is arranged above one end of the paper feed cassette 3, and the printing paper 1 in the paper feed cassette 3 is picked up one by one by the rotation of the paper feed roller 4 and sent to the paper guide 5. The inkjet head 6 is arranged on the downstream side of the paper guide 5 so as to face the paper path 2, and the paper support 7 is arranged so as to sandwich the paper path 2 and face the ink jet head 6. Further, nozzles (not shown) for ejecting ink are formed on the surface of the inkjet head 6 facing the paper path 2, and the print paper 1 sent through the paper guide 5 is placed on the paper support 7. Printing is performed by ejecting ink onto the printing paper 1 from the nozzles of the inkjet head 6 in the supported state.

A pair of first and second feed rollers 8 and 9 are arranged on the upstream side and the downstream side of the paper path 2 with the inkjet head 6 interposed therebetween, and the rotation of these feed rollers 8 and 9 is performed. Thus, the feeding is applied to the printing paper 1 that passes through the paper path 2. An opening 10 is formed in the paper support 7, and a sensor 11 is arranged at a position corresponding to the opening 10 so as to face the paper path 2. The sensor 11 is a reflection type photo sensor, and when the leading edge of the print sheet 1 passing through the sheet path 2 reaches a position facing the sensor 11, the sensor 11 detects the leading edge of the sheet 1 and the inkjet head 6 The operation command of is output. The sensor 11 is arranged at the position of the nozzle of the ink jet head 6, that is, slightly upstream of the portion of the ink jet head 6 on which printing is actually performed.

In the inkjet printer of this embodiment, a large number of printing papers 1 in the paper feed cassette 3 are picked up one by one by the rotation of the paper feed roller 4, and the first paper is guided via the paper guide 5. It is fed between the feed rollers 8. Then, the printing paper 1 fed between the first feed rollers 8 is fed by the rotation of the rollers 8 and fed onto the paper support 7, and the leading end thereof is detected by the sensor 11. Then, the sensor 11 outputs an operation command to the inkjet head 6, and when the first feed roller 8 is rotated by a predetermined amount and the print start position of the print sheet 1 faces the nozzle, the print sheet 1 is ejected. Printing is performed by operating the inkjet head 6 while being supported on the support 7 and ejecting ink from the nozzles of the head 6 onto the printing paper 1. Then, the printing paper 1 passed between the inkjet head 6 and the paper support 7 is sent between the second feed rollers 9 and is discharged to the outside of the apparatus by the rotation of the rollers 9.

As described above, in the inkjet printer of this embodiment, after the printing paper 1 is fed between the first feed rollers 8, the leading edge of the paper 1 passes between the first feed rollers 8. The ink jet head 6 is activated after the sensor 11 detects That is, the inkjet head 6 is not operated in a state where the printing paper 1 is not fed between the first feed rollers 8 and a paper jam occurs and the printing paper 1 is not fed to the nozzle position of the inkjet head 6.

Therefore, unlike the above-mentioned conventional method, the inkjet head 6 is operated in a state where the printing paper 1 is not fed to the position of the nozzle of the inkjet head 6, and the paper support 7 and the inside of the apparatus are contaminated. Therefore, the printing by the inkjet head 6 is reliably performed on the printing paper 1. . Further, after the sensor 11 detects the leading edge of the printing paper 1, printing is performed immediately from the leading edge of the printing paper 1, so that a large blank area where image information is not printed is formed at the front of the printing paper 1. The paper surface of the printing paper 1 can be effectively used without causing any trouble.

[0013]

[Effect of the device]

 As described in detail above, according to the present invention, it is possible to reliably perform printing on printing paper, the paper support and the inside of the device are not contaminated during printing, and moreover, the leading edge of the printing paper is required. This has the excellent effect that printing can be performed from a position and a large unprintable area is not formed in the front part of the printing paper.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of an ink jet printer embodying the present invention.

FIG. 2 is a schematic cross-sectional view showing a conventional inkjet printer.

[Explanation of symbols]

1 printing paper, 6 inkjet head, 7 paper support, 8 first feed roller, 11 sensor.

Claims (1)

[Claims for utility model registration] [Claim 1] Printing paper is fed by a feed roller so as to pass over the paper support, and image information is printed on the printing paper by an inkjet head on the paper support. In the inkjet printer described above, between the feed roller and the inkjet head, the tip of the printing paper fed from the feed roller is detected,
An inkjet printer provided with a sensor for outputting an operation command of an inkjet head.