JP4869412B2 - Inkjet recording apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an ink jet recording apparatus and an image forming apparatus, and more particularly to an ink jet recording apparatus and an image forming apparatus provided with a paper pressing member that presses a paper.

  In general, an ink jet recording apparatus used as an image recording apparatus or an image forming apparatus such as a printer, a copying apparatus, a facsimile machine, or a plotter has a nozzle for discharging ink droplets and a discharge chamber (pressure chamber, pressurized liquid chamber, Liquid chamber, ink flow path, etc.) and energy generating means for generating energy to pressurize the ink in the discharge chamber, and driving the energy generating means to pressurize the ink in the discharge chamber. Ink droplets are ejected from the nozzles, and an image is recorded on paper (meaning that an image is recorded, and the material is not limited to paper).

  However, in an ink jet recording apparatus, ink droplets are landed on a sheet to perform recording. Therefore, when printing is performed with the trailing edge of the sheet free, the trailing edge of the sheet is caused by cockling or curling of the sheet itself. The paper jumps up, the paper comes into contact with the recording head, and the image becomes dirty or the nozzles are clogged. For this reason, all images must be recorded in a state where the trailing edge of the sheet is pressed, the margin at the trailing edge of the sheet is increased, and the image recordable area is narrowed.

  Therefore, in the conventional ink jet recording apparatus, as described in, for example, Patent Documents 1 and 2, in order to press the trailing edge of the sheet, which has been removed from the conveying roller, to the limit of the printing area by the recording head. Some include a sheet pressing member such as a sheet-like elastic body or a leaf spring.

JP-A-6-293168 Japanese Utility Model Publication No. 7-40144

  However, when a paper pressing member for pressing the paper to the limit of the printing area is provided as in the conventional inkjet recording apparatus described above, when a paper jam occurs, the paper is pressed when the jammed paper is removed. There is a problem that the workability of the jam processing (paper jam processing) is deteriorated such that the paper is caught on the member, the paper may tear and remain in the main body, and it takes time to remove the remaining paper.

  The present invention has been made in view of the above points, and it is an object of the present invention to reduce the occurrence of image smearing when a sheet contacts a head.

In order to solve the above problems, an ink jet recording apparatus according to the present invention includes:
A printing receiving member facing the recording head;
Conveying means comprising a conveying roller and a plurality of rollers facing the conveying roller, and conveying means for conveying paper to the printing receiving member;
A paper pressing member that presses the paper sent from the conveying means to the printing receiving member,
One end side of the sheet pressing member is locked to the upstream side in the transport direction from the roller, and the other end side is a direction passing through the axis of the support shaft of the roller and only in a region where the roller is not disposed. The sheet is disposed between the support shaft and the transport roller and presses the sheet against the printing receiving member on the downstream side in the transport direction of the support shaft.

  Here, the sheet pressing member can be configured to press on the rib formed on the printing receiving member.

  Further, the conveying roller may be divided into a plurality of parts.

  In this case, the rib formed on the printing receiving member can be formed at least directly below the support shaft.

  Further, a collar member may be interposed between the paper pressing member and the support shaft of the roller.

  Further, the paper pressing member can be configured to press the paper at a plurality of locations and be individually rotatable at each location.

An image forming apparatus according to the present invention includes:
A printing receiving member facing the recording head;
Conveying means comprising a conveying roller and a plurality of rollers facing the conveying roller, and conveying means for conveying paper to the printing receiving member;
A paper pressing member that presses the paper sent from the conveying means to the printing receiving member,
One end side of the sheet pressing member is locked to the upstream side in the transport direction from the roller,
The other end side is disposed between the support shaft and the transport roller only in a region passing through the axis of the support shaft of the roller and not including the roller, and on the downstream side in the transport direction of the support shaft . The sheet is pressed against the printing receiving member .

The ink jet recording apparatus according to the present invention and the image forming apparatus according to the present invention can reduce the occurrence of image smearing due to the paper contacting the head.

FIG. 2 is a schematic perspective explanatory view of a mechanism portion of the ink jet recording apparatus according to the present invention. It is principal part side explanatory drawing of the mechanism part. FIG. 3 is an enlarged view of a main part of FIG. 2. It is principal part plane explanatory drawing of the mechanism part.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic perspective view of a mechanism portion of an ink jet recording apparatus according to the present invention as an image forming apparatus according to the present invention, FIG. 2 is a side view of an essential portion of the mechanism portion, and FIG. 3 is an enlarged view of the main portion of FIG. 4 and 4 are plan views of the main part of the mechanism.

  In this recording apparatus, a main support guide rod 1 and a sub support guide rod 2 are horizontally placed between side plates on both sides in a substantially horizontal positional relationship, and the main support guide rod 1 and the sub support guide rod 2 support the carriage 3. It is slidably supported in the scanning direction. On the lower surface side of the carriage 3, a recording head 4 that discharges yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (Bk) ink is disposed below the discharge surface (nozzle surface). In addition, an ink cartridge 5 of each color for supplying ink of each color to the recording head 4 is mounted on the upper surface side of the carriage 3 in a replaceable manner.

  As the recording head 4, a plurality of heads that eject ink droplets of each color may be used, or a single head having nozzles that eject ink droplets of each color may be used. The ink jet head used as the recording head 4 is an ink that pressurizes ink through a vibration plate that forms the wall surface of a liquid chamber with an electromechanical transducer such as a piezoelectric element, or generates bubbles by film boiling by a heating resistor. Or a device that pressurizes ink by displacing the diaphragm with an electrostatic force between the diaphragm that forms the wall surface of the liquid chamber and the electrode facing the diaphragm.

  The carriage 3 is connected to a timing belt 10 stretched between a drive pulley (drive timing pulley) 8 and a driven pulley (idler pulley) 9 that are rotated by the main scanning motor 7 to drive the main scanning motor 7. By controlling, the carriage 3 is moved and scanned in the main scanning direction.

  Further, as shown in FIG. 2, a conveying roller 12 for rotatably feeding the paper 11 in a sub-scanning direction orthogonal to the main scanning direction is held between side plates (not shown). The transport roller 12 transmits the rotation of the sub-scanning motor 13 shown in FIG. 1 through a gear train (not shown). The transport roller 12 is set in the paper feed cassette 14 and reverses and transports the paper 11 fed by the paper feed roller 15.

  A pressure roller 16 for turning (reversing) the paper 11 along the surface of the conveyance roller 12 and a tip roller 17 as a pressing roller are rotatably disposed on the circumferential surface of the conveyance roller 12. These conveying roller 12, pressure roller 16, tip roller 17 and the like constitute a conveying means. Then, on the downstream side of the conveyance roller 12 in the sheet conveyance direction, the sheet 11 that faces the recording head 4 and is fed from the conveyance roller 12 corresponding to the movement range of the carriage 3 in the main scanning direction is below the recording head 4. The printing receiving member 18 to be guided is arranged.

  3 and 4, the printing receiving member 18 has a length corresponding to the moving range of the carriage 3 in the main scanning direction printing area, and has a number of second ribs 19 in the main scanning direction. A plurality of first ribs 20 are formed at a required interval. The sheet 11 is guided while being in contact with the uppermost surfaces of the first rib 20 and the second rib 19, whereby the distance between the recording head 4 and the surface of the sheet 11 (printing surface) is defined.

  Then, on the upstream side of the printing receiving member 18 in the paper conveyance direction, a paper pressing member 21 made of a torsion coil spring as an elastic member is provided at a position corresponding to the first rib 20 of the printing receiving member 18. 4 and adjacent to the tip roller 17 that is a pressing roller, here, as shown in FIG. 4, it is rotatably attached to a support shaft 17a of the tip roller 17. As shown in FIG. 4, the sheet pressing member 21 has a tapered shape toward the downstream side in the sheet conveyance direction. Further, although a plurality of sheet pressing members 21 and 21 are provided in FIG. 4, they can be independently rotated.

  As shown in FIG. 3, the paper pressing member 21 presses the paper 11 on the first rib 20, but the downstream end of the paper pressing member 21 in the paper transport direction reaches the second rib 19. The second rib 19 is a rib that is not pressed by the sheet pressing member 21. Further, as shown in FIG. 4, the downstream end portion (downstream end) of the first rib 20 in the sheet conveyance direction has a positional relationship that is upstream of the downstream end of the second rib 19 in the sheet conveyance direction. Yes.

  The rear end portion 21 a of the sheet pressing member 21 is locked by the locking portion 22, and the sheet pressing member 21 is pressed against the rib 20 of the printing receiving member 18 by an elastic restoring force. With the support shaft 17a as the center, it can be rotated by 90 ° or more in the direction opposite to the sheet pressing direction (the arrow direction in FIG. 3). That is, the sheet pressing member 21 is locked to the upstream side in the transport direction with respect to the roller 17 at one end side, and the support shaft 17a only in the region where the other end side is in the support shaft direction of the roller 17 and the roller 17 is not disposed. The sheet 11 is disposed between the conveyance roller 12 and presses the sheet 11 on the downstream side in the conveyance direction of the support shaft 17a. Further, as shown in FIG. 3, the height of the sheet pressing position (the height of the rib surface of the first rib 20), which is the position where the sheet pressing member 21 comes into contact with the sheet on the first rib 20, is conveyed. The height of the nip position between the roller 12 and the tip roller 17 is lower.

  The rear end portion 21 a of the sheet pressing member 21 is locked by the locking portion 22, and the sheet pressing member 21 is pressed against the rib 20 of the printing receiving member 18 by an elastic restoring force. With the support shaft 17a as the center, it can be rotated by 90 ° or more in the direction opposite to the sheet pressing direction (the arrow direction in FIG. 3). As described above, the sheet pressing member is rotatably mounted on the support shaft of the pressing roller so that the number of parts does not increase.

  A collar member 23 is interposed between the sheet pressing member 21 and the support shaft 17 a of the leading end roller 17. As the collar member 23, for example, a material having good slidability such as polyacetal can be used to reduce the occurrence of abnormal noise due to sliding between the paper pressing member 21 and the leading roller shaft 17a. preferable.

  Further, on the downstream side of the printing receiving member 18 in the paper transport direction, a first paper discharge roller 25 that is rotationally driven to send the paper 11 in the paper discharge direction, a spur roller 26 that contacts the first paper discharge roller 25, and a transport path forming member 27. A second paper discharge roller 28 and a spur roller 29 in contact with the second paper discharge roller 28 are arranged, and a paper discharge tray 30 mounted in an inclined state for stocking the paper 11 to be discharged is provided.

  In the ink jet recording apparatus configured as described above, when the paper 11 is fed from the cassette 14 by the paper feed roller 15, the paper is reversed by the intermediate roller 16 along the peripheral surface of the transport roller 11 and pressed by the leading roller 17. Then, the paper 11 is sent out from the conveying roller 12 and guided to the ribs 19 and 20 of the printing receiving member 18, and then the back surface of the paper 11 is guided while being in contact with the uppermost surfaces of the ribs 19 and 20. The distance between the head 6 and the head 6 is regulated.

  Therefore, ink droplets are ejected from the head 4 and an image is printed on the paper 11 by, for example, an interlace printing method. At this time, the paper 11 is printed on the printing receiving member 18 while maintaining the flatness on the paper feeding side held by the transport roller 12 and the leading end roller 17 and the paper discharging side held by the first paper discharging roller 25 and the spur 26. , Transported. When the trailing edge of the sheet 11 passes through the leading end roller 17, the trailing edge of the sheet is pressed against the rib 20 of the printing receiving member 18 only by the sheet pressing member 21, and printing is performed in this state.

  Here, when the paper 11 is jammed, the paper pressing member 21 is rotated by 90 ° or more about the support shaft 17a of the leading end roller 17 from the state where the paper pressing member 21 is pressed against the rib 20 of the printing receiving member 18. Therefore, the jammed paper can be removed by separating the paper pressing member 21 from the rib 20 and the jam handling operation is facilitated.

  In addition, the jam of the paper pressing member 21 is prevented because the tip of the paper pressing member 21 hardly damages the paper 11, the jammed paper 11 is torn by the paper pressing member 21, and the remaining paper remaining on the main body cannot be removed. It becomes easy.

  In this case, since the elastic member is used as the paper pressing member 21, the paper pressing member 21 is pressed onto the first rib 20 of the printing receiving member 18 by the elastic restoring force after the jammed paper is removed. Therefore, the workability of the jam handling work is further improved. Further, since the sheet pressing member 21 is an elastic member, it is possible to prevent problems such as contact with the head due to insufficient pressing of the trailing edge of the sheet due to plastic deformation.

  In the above embodiment, the example using the tip roller and the torsion coil spring as the sheet pressing means has been described. However, for example, a combination of a sheet guide and a sheet may be used, and the sheet pressing member is not limited to the torsion coil spring. A spring or the like may be used. Further, as described above, the present invention can also be applied to an image forming apparatus such as a printer, a facsimile, a copying apparatus, and a plotter.

DESCRIPTION OF SYMBOLS 3 ... Carriage 4 ... Recording head 12 ... Conveying roller 17 ... Lead end roller 17a ... Support shaft of tip end roller 18 ... Printing receiving member 19 ... Second rib 20 ... First rib 21 ... Paper pressing member 23 ... Color member

Claims (7)

A printing receiving member facing the recording head;
Conveying means comprising a conveying roller and a plurality of rollers facing the conveying roller, and conveying means for conveying paper to the printing receiving member;
A paper pressing member that presses the paper sent from the conveying means to the printing receiving member,
One end side of the sheet pressing member is locked to the upstream side in the transport direction from the roller, and the other end side is a direction passing through the axis of the support shaft of the roller and only in a region where the roller is not disposed. An ink jet recording apparatus, wherein the ink jet recording apparatus is disposed between a support shaft and the transport roller and presses the sheet against the printing receiving member on the downstream side of the support shaft in the transport direction.   2. The ink jet recording apparatus according to claim 1, wherein the sheet pressing member presses on a rib formed on the printing receiving member.   The ink jet recording apparatus according to claim 1, wherein the transport roller is divided into a plurality of parts. 3. The ink jet recording apparatus according to claim 2 , wherein the rib formed on the printing receiving member is formed at least directly below the support shaft.   The inkjet recording apparatus according to claim 4, wherein a collar member is interposed between the sheet pressing member and the support shaft of the roller.   The ink jet recording apparatus according to claim 1, wherein the sheet pressing member presses the sheet at a plurality of locations and is individually rotatable at each location. A printing receiving member facing the recording head;
Conveying means comprising a conveying roller and a plurality of rollers facing the conveying roller, and conveying means for conveying paper to the printing receiving member;
A paper pressing member that presses the paper sent from the conveying means to the printing receiving member,
One end side of the sheet pressing member is locked to the upstream side in the transport direction from the roller,
The other end side is disposed between the support shaft and the transport roller only in a region passing through the axis of the support shaft of the roller and not including the roller, and on the downstream side in the transport direction of the support shaft . An image forming apparatus , wherein the sheet is pressed against the printing receiving member .

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