JP2006143477A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of causing an abnormal image and damage of a head, when paper contacts with the head, when flapping becomes large, when a cock ring of the paper is generated in imaging. <P>SOLUTION: An imaging receiving member 27 is arranged for guiding the paper 3 carried oppositely to a recording head 14. A plurality of different height ribs 28a and 28b are arranged at a different interval in the imaging receiving member 27. A part on the inside a little from both ends in the paper width direction, becomes a place where a rib interval between the high ribs 28a and 28a is not an equal interval, by arranging two low ribs 28b and 28b sandwiched by the two high ribs 28a and 28a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to a structure of a printing receiving member disposed to face a head.

  An ink jet recording apparatus used as an image recording apparatus (image forming apparatus) such as a printer, a facsimile machine, a copying apparatus, etc. means paper (an image is recorded) by ejecting ink droplets from a nozzle (ejection port) of an ink jet head. (This is not limited to paper.) Since the image is recorded on the recording head and the relative positional relationship between the recording head and the paper is deviated, the image quality deteriorates. Therefore, it is necessary to transport the paper stably and accurately. become.

  In addition, since the ink jet recording apparatus records ink droplets attached to the paper, the paper is likely to wavy (cockling) during printing, and thus the flatness of the paper with respect to the head cannot be ensured. If the gap between the paper and the head varies and the image is disturbed or the waviness becomes large, the paper and the head come into contact with each other, and an abnormal image or head damage occurs.

Therefore, conventionally, as described in, for example, Patent Documents 1 to 3, in order to maintain the flatness of the sheet and the recording head, a conveyance roller is arranged on the upstream side and the downstream side of the sheet conveyance. .
Japanese Patent Laid-Open No. 7-125364 Japanese Patent Laid-Open No. 7-132659 Japanese Patent Laid-Open No. 9-24650

  However, in the ink jet recording apparatus in which the conveyance rollers are arranged on the upstream side and the downstream side of the sheet conveyance, printing must be performed with the leading and trailing ends of the sheet held by the conveyance rollers. Due to restrictions, the unprintable areas (so-called leading margin and trailing margin) at the leading edge and the trailing edge of the sheet become large.

  In addition, there is an actual machine that can be handled by bending and pulling the paper in advance in the transport path, or by applying stiffness, but this causes the image to be disturbed because the gap changes due to the difference in the thickness of the paper.

  SUMMARY An advantage of some aspects of the invention is to prevent contact between a sheet and a head due to cockling with a simple configuration.

  In order to solve the above problems, an image forming apparatus according to the present invention is provided with a printing receiving member for guiding a sheet conveyed facing a recording head, and the printing receiving member has a different height. The ribs are formed at two or more different intervals, and there are portions where the intervals between the high ribs are not equal.

  The image forming apparatus according to the present invention is provided with a printing receiving member for guiding a sheet conveyed facing the recording head, and the printing receiving member has ribs having different heights at two or more different intervals. It is formed, and there is a configuration in which a low rib is sandwiched between two high ribs, and there are places where the intervals between the high ribs are not equal.

  In each of the image forming apparatuses according to each of the present inventions, a portion where the intervals between the high ribs are not equal may be provided at the end in the sheet width direction.

  According to the image forming apparatus of the present invention, the printing receiving member for guiding the sheet conveyed facing the recording head is provided, and the printing receiving member has two or more ribs having different heights. Since there is a portion where the intervals between the high ribs are not equal intervals, the interference between the head and the paper due to cockling can be prevented with a simple configuration.

  According to the image forming apparatus of the present invention, the printing receiving member for guiding the sheet conveyed facing the recording head is provided, and the printing receiving member has two or more ribs having different heights. Since there is a part where the low ribs are sandwiched between the two high ribs and the distance between the high ribs is not equal, the interference between the head and the paper due to cockling is simplified. Can be prevented.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing a mechanical part of an ink jet recording apparatus as an image forming apparatus according to a first embodiment of the present invention, FIG. 2 is a schematic perspective view of the main part of the recording apparatus, and FIG. It is a front view of a printing receiving member.

  The ink jet recording apparatus includes a carriage that is movable in the main scanning direction inside the recording apparatus main body 1, a recording head that includes an ink jet head mounted on the carriage, an ink cartridge that supplies ink to the recording head, and the like. A sheet feeding cassette (or a sheet feeding tray) 4 capable of stacking a large number of sheets 3 from the front side can be removably attached to the lower part of the apparatus main body 1. The paper 3 fed from the paper feed cassette 4 is taken in, a required image is recorded by the printing mechanism unit 2, and then discharged to a paper discharge tray 6 mounted on the rear side.

  The printing mechanism unit 2 holds a carriage 13 slidably in a main scanning direction (perpendicular to the paper in FIG. 1) by a main guide rod 11 and a sub guide rod 12 which are horizontally mounted on left and right side plates (not shown). On the lower surface side of 13, a recording head 14 composed of an inkjet head having nozzles for discharging ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk) is disposed in the ink droplet discharge direction downward. Each ink tank (ink cartridge) 15 for supplying ink of each color to the recording head 14 is replaceably mounted on the upper side of the carriage 5.

  The recording head 14 may be one in which a plurality of heads that eject ink droplets of each color are arranged in the main scanning direction, or one that has a nozzle that ejects ink droplets of each color. But you can.

  On the other hand, in order to convey the paper 3 set in the paper feed cassette 4 to the lower side of the recording head 14, the paper feed roller 21 and the friction pad 22 for separating and feeding the paper 3 from the paper feed cassette 4 and the paper 3 are guided. The guide member 23 that performs the above operation, the transport roller 24 that reverses and transports the fed paper 3, the transport roller 25 that is pressed against the peripheral surface of the transport roller 24, and the feed angle of the paper 3 from the transport roller 15 are defined. A conveyance roller 26 is provided.

  A printing receiving member 27 is provided as a paper guide member that guides the paper 3 fed from the transport roller 24 below the recording head 4 corresponding to the range of movement of the carriage 5 in the main scanning direction. As shown in FIGS. 2 and 3, the printing receiving member 27 has a large number of ribs 28a and 28b. The ribs 28a and 28b of the printing receiving member 27 are formed in the width direction of the paper at substantially equal intervals, and the height of the rib 28b slightly inside the width direction end of the paper is set to other ribs as shown in FIG. It is formed lower than the height of 28a (may be about 1 mm).

  A conveyance roller 31 and a spur 32 that are rotationally driven to send out the paper 3 in the paper discharge direction are provided on the downstream side of the printing receiving member 27 in the paper conveyance direction, and the paper 3 is sent out to the paper discharge tray 6. A roller 33 and a spur 34, and guide members 35 and 36 that form a paper discharge path are disposed.

  In this ink jet recording apparatus, the sheet 3 fed from the transport roller 24 is transported along the ribs 28a of the printing receiving member 27 as shown in FIG. An ink droplet that is defined by the gap and ejected from the recording head 14 is attached.

  Here, a cockling phenomenon occurs in which the paper swells within a few seconds after the ink droplets adhere to the paper. Due to this cockling, both ends in the width direction of the sheet normally swell up. In other words, when an image is recorded on paper, margins that are non-printing parts are always formed on the top, bottom, left, and right of the paper, so the boundary between the printing parts and the non-printing parts (margins) at both ends in the width direction of the paper. This is because the ink in the printing portion is pulled to dry and the both end portions of the sheet swell upward.

  Therefore, as shown in FIG. 5, when only the gap defining rib 28 a is provided on the printing receiving member 27 (when the height of the rib is constant), the recording head 14 bulges at both ends of the sheet 3. The paper may get dirty or the head may be damaged.

  Therefore, as in the present embodiment, the printing receiving member 27 is provided with ribs 28a for defining a gap, and the height of the ribs 28b slightly inside the both ends in the paper width direction is made lower than the ribs 28a. As shown in FIG. 6, the sheet 3 swollen with ink droplets falls at the ribs 28b, and the upward swelling of both end portions of the sheet 3 can be suppressed, and interference with the recording head 14 can be prevented. .

  In this case, if the amount of ink adhering to the paper 3 is small and cockling does not occur, even the portion of the rib 28b having a low height is kept straight by the stiffness of the paper 3, so that the gap with the recording head 14 varies. There is nothing.

  Thus, by providing a plurality of ribs having different heights on the printing receiving member facing the recording head, interference between the paper and the head due to cockling can be prevented with a simple configuration.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the printing receiving member 27 is provided with a plurality of ribs 28a, and the interval between the ribs 28a is widened at portions slightly inside from both ends in the paper width direction. As a result, as shown in FIG. 8, the sheet 3 swelled by ink droplets falls down at the portion where the interval between the ribs 28a is wide, and the upward bulging of both ends of the sheet 3 can be suppressed. Interference can be prevented.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, as shown in FIG. 9, the printing receiving member 27 is provided with ribs 28a and 28b having different heights (with different heights), and the rib interval between the high ribs 28a and the ribs of the low ribs 28b. The interval is different. A portion slightly inside from both ends in the paper width direction is formed by sandwiching two low ribs 28b, 28b between two high ribs 28a, 28a, and the intervals between the high ribs 28a, 28a are not equal. It is a place.

  Thus, here, the printing receiving member is formed with ribs having different heights (with different heights) at two or more different intervals, and the intervals between the high ribs are not equal (see above). In the example shown in FIG. 2, there is a vicinity of both ends in the paper width direction. Further, the printing receiving member is formed with ribs having different heights (with different heights) at two or more different intervals, the lower ribs are sandwiched between two higher ribs, and the intervals between the higher ribs are equal. There are places that are not spaced apart (in the above example, near both ends in the paper width direction).

  As a result, as shown in FIG. 10, the paper 3 swelled with the ink droplets adhering to the paper 3 swells at the portions of the ribs 28 b and 28 b where the height of the ribs is not equal, and the height is low and wide. It is possible to suppress the upward bulging of both ends, and to prevent interference with the recording head 14.

  In the above-described embodiment, two types of rib heights and two types of rib intervals have been described. However, any of three or more types of heights or intervals may be used. Further, ribs having different heights can be alternately provided, and the interval can be alternately changed.

  The image forming apparatus according to the present invention can be configured as, for example, a printer, a facsimile, a copying apparatus, or the like as described above, but is not limited thereto.

1 is a schematic configuration diagram illustrating a mechanism unit of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view of a main part of the recording apparatus. FIG. 3 is a front view of a printing receiving member of the recording apparatus. FIG. 6 is an explanatory diagram for explaining the operation of the recording apparatus. It is explanatory drawing of the comparative example with which it uses for operation | movement description of the same embodiment. It is explanatory drawing with which it uses for operation | movement description of the same embodiment. It is a front view of the printing receiving member of the recording apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing with which it uses for operation | movement description of the same embodiment. It is a front view of the printing receiving member of the recording device which concerns on 3rd Embodiment of this invention. It is explanatory drawing with which it uses for operation | movement description of the same embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus body 2 ... Printing mechanism part 3 ... Paper 4 ... Paper feed cassette 6 ... Paper discharge tray 13 ... Carriage 14 ... Recording head 24 ... Conveyance roller 27 ... Printing receiving member 28a ... High rib 28b ... Low rib

Claims (3)

  In an image forming apparatus that prints an image on a sheet by ejecting droplets from a recording head, a printing receiving member is provided for guiding a sheet conveyed opposite the recording head. An image forming apparatus characterized in that ribs having different heights are formed at two or more different intervals, and the intervals between the high ribs are not equal.   In an image forming apparatus that prints an image on a sheet by ejecting droplets from a recording head, a printing receiving member is provided for guiding a sheet conveyed opposite the recording head. The image forming is characterized in that the ribs having different heights are formed at two or more different intervals, the low ribs are sandwiched between two high ribs, and the intervals between the high ribs are not equal. apparatus. 3. The image forming apparatus according to claim 1, wherein a portion where the intervals between the high ribs are not equal is located at an end in the sheet width direction.

Images