JP2010076290A - Image recording apparatus - Google Patents

Abstract

To reduce the size in the transport direction.
An inkjet printer 1 includes four inkjet heads 2 arranged in the sub-scanning direction, a conveyance mechanism that faces the four inkjet heads 2 and conveys paper along the sub-scanning direction, and an inkjet printer in a standby state. Maintenance unit 50 disposed on the side of the head 2 along the sub-scanning direction, standby units 40c and 40d disposed below the inkjet head 2, and the side of the standby units 40c and 40d along the sub-scanning direction And a paper discharge tray 80 disposed at the same position.
[Selection] Figure 1

Description

  The present invention relates to an image recording apparatus that records an image on a recording medium.

  Patent Document 1 describes an image recording apparatus having a serial type recording head. In this image recording apparatus, a standby unit is provided downstream from the recording head, and curling of the recorded paper is suppressed by restraining the recorded paper from above and below by the standby unit. Furthermore, the recording head and the maintenance unit for the recording head are arranged side by side in a direction orthogonal to the transport direction.

Japanese Patent Laying-Open No. 2006-82546 (FIG. 1)

  In the image recording apparatus described in Patent Document 1, a line type recording head is used instead of the serial type recording head, and in order to prevent the apparatus from being enlarged in the orthogonal direction, the recording head and the maintenance unit are provided. It is conceivable to arrange them side by side in the transport direction. However, if it does in this way, a recording head, a standby part, and a maintenance unit will be located in a conveyance direction, and an apparatus will enlarge in a conveyance direction.

  Accordingly, an object of the present invention is to provide an image recording apparatus that is miniaturized in the transport direction.

  The image recording apparatus of the present invention includes a recording head that records an image on a recording medium, a transport mechanism that faces the recording head and transports the recording medium along a substantially horizontal transport direction, and the recording head in a standby state. A maintenance unit for maintaining the recording head, and a recording medium that is disposed below the recording head and on which an image is recorded by the recording head, along the conveying direction. A first standby unit that is held substantially flat and stopped; and a discharge unit that is disposed on a side of the first standby unit along the transport direction and on which a recording medium on which an image is recorded by the recording head is stacked. It is equipped with.

  According to the image recording apparatus of the present invention, the recording head and the maintenance unit are arranged side by side in the conveyance direction, and the first standby unit and the discharge unit are arranged side by side in the conveyance direction below the recording head. Can be miniaturized.

  In addition, a plurality of the first standby units are arranged in the vertical direction, and a recording medium on which an image is recorded by the recording head is disposed on a conveyance path between the plurality of first standby units and the recording head. It is preferable that a first distribution mechanism that selectively distributes one of the plurality of first standby units is disposed. If there is one first standby unit and a recording medium preceding the first standby unit is held, the next recording medium is set as the first standby unit until the recording medium is discharged to the discharge unit. I can't hold it. Therefore, by arranging a plurality of first standby units and selectively distributing the recording medium to one of the plurality of first standby units by the first distribution mechanism, high-speed conveyance is possible.

  Furthermore, it is preferable that the first standby unit includes a drying unit that dries a recording medium on which an image is recorded by the recording head. According to this, the recording medium on which the image is recorded can be quickly dried by the drying means, and the standby time in the first standby unit of the recording medium can be shortened.

  In addition, it is preferable that a plurality of the recording heads are arranged along the transport direction. According to this, since a plurality of recording heads are arranged along the transport direction, high-speed printing on a recording medium is possible.

  Further, it is preferable that the apparatus further includes a housing in which the transport mechanism, the recording head, and the first standby unit are arranged, and the first standby unit is detachable from the housing. According to this, when the recording medium is jammed in the first standby unit, the jam processing becomes easy.

  Furthermore, it is preferable that the apparatus further includes a housing in which the transport mechanism, the recording head, and the standby unit are disposed, and the discharge unit protrudes from the housing. According to this, it is easy to take out the recording medium.

  In addition, determination means for determining whether or not it is necessary to hold and stop the recording medium on which the image is recorded by the recording head in the first standby unit based on the recording data of the image on the recording medium. And when the determination unit determines that the recording medium needs to be stopped by the first standby unit, the recording medium is held and stopped by the first standby unit, and is determined unnecessary. It is preferable to pass the recording medium without stopping at the first standby unit. According to this, the standby at the first standby unit of the recording medium can be minimized.

  Furthermore, it is preferable that a reading unit for reading an image recorded on the recording medium is disposed above the discharge unit.

  In addition, it is preferable that the supply unit that can accommodate the recording medium and supplies the recording medium to the transport mechanism is disposed below the recording head and above the first standby unit. According to this, since the supply unit is disposed below the recording head and above the first standby unit, the apparatus can be further downsized in the transport direction.

  Further, the recording medium transported by the transport mechanism is re-routed to the transport mechanism again and the recording head is disposed above the recording head, and the recording medium on which an image is recorded by the recording head is held substantially flat. And a second standby unit for stopping the recording medium, and when performing double-sided printing on the recording medium, the recording medium on which an image is recorded by the recording head is once transported to the second standby unit, and then switched back. It is preferable to carry to the retransmission route. According to this, the second standby unit can be used during duplex printing. Further, the recording medium on which only one surface is recorded by the recording head at the time of the first printing in the duplex printing can be held and stopped by the second standby unit.

  In addition, a plurality of the second standby units are arranged along the vertical direction, and a recording in which an image is recorded by the recording head on a conveyance path between the plurality of second standby units and the recording head. It is preferable that a second distribution mechanism that selectively distributes the medium to any of the plurality of second standby units is disposed. If there is one second standby section and a recording medium preceding the second standby section is held during double-sided printing, the next recording medium is loaded until the recording medium is discharged to the discharge section. It cannot be held in the second standby unit. Therefore, by arranging a plurality of second standby units and selectively distributing the recording medium to any one of the plurality of second standby units by the second distribution mechanism, high-speed conveyance is possible.

  Since the recording head and the maintenance unit are arranged side by side in the conveyance direction, and the first standby unit and the discharge unit are arranged side by side in the conveyance direction below, the apparatus can be downsized in the conveyance direction.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The present embodiment is an example in which the present invention is applied to an ink jet printer that records characters, images, and the like by ejecting ink onto recording paper.

  FIG. 1 is a schematic sectional view of an ink jet printer according to an embodiment of the present invention. As shown in FIG. 1, an inkjet printer 1 that is an image recording apparatus has a housing 10 having a space inside. In the housing 10, two standby units 40 arranged in the vertical direction in order from the top, four inkjet heads 2 arranged along the sub-scanning direction (left and right direction in FIG. 1), the maintenance unit 50, and the transport mechanism 21. A sheet feeding device 30 (supply unit), a retransmission path 60, two standby units 40 arranged in the vertical direction, and an ink tank cassette 70 are arranged. Furthermore, the inkjet printer 1 includes a control unit 100 (see FIG. 4) that controls various operations.

  The four standby units 40 arranged in the vertical direction in the housing 10 are referred to as standby units 40a, 40b, 40c, and 40d in order from the top. The standby units 40c and 40d arranged below the paper feed cassette 31 in the present embodiment correspond to the first standby unit in the present invention. The standby units 40a and 40b arranged above the inkjet head 2 in the present embodiment correspond to the second standby unit in the present invention. In the casing 10 of the ink jet printer 1, a paper transport path for transporting paper is formed along the thick arrow shown in FIG.

  The sheet feeding device 30 includes a sheet feeding cassette 31 that can store a plurality of stacked sheets, a sheet feeding roller 32 that feeds sheets from the sheet feeding cassette 31, and a sheet feeding motor 132 that rotates the sheet feeding roller 32 (FIG. 4). Reference). Since the paper feeding device 30 is disposed below the ink jet head 2, the ink jet printer 1 can be downsized in the sub-scanning direction.

  The paper feed roller 32 feeds the paper by rotating and contacting the uppermost paper among the plurality of papers stored in the paper feed cassette 31. The left side of the transport mechanism 21 in the housing 10 in FIG. 1 extends in a paper transport path from the paper feed cassette 31 to the transport mechanism 21 while curving from the paper feed cassette 31 toward the transport mechanism 21. Conveying guides 27a to 27c to be carried out, and roller pairs 26a and 26b and a separating roller pair 26c disposed between the conveying guides 27a to 27c are provided. One of the roller pairs 26a and 26b and the separation roller pair 26c is a driving roller that is rotated by a feed motor (not shown), and the other roller is a driven roller that rotates as one roller rotates. The paper in contact with the paper feed roller 32 is guided to the transport mechanism 27 while being guided by the transport guides 27a to 27c and sandwiched between the roller pairs 26a and 26b and the separation roller pair 26c.

  The transport mechanism 21 includes two belt rollers 6, 7, an endless transport belt 8 wound around the rollers 6, 7, and an inner peripheral surface of the lower loop of the transport belt 8. It has tension rollers 9a and 9b that apply tension to the transport belt 8 by being biased downward while in contact with it, and a transport motor 133 (see FIG. 4) that rotates the belt roller 7 to horizontally level the paper. In the proper transport direction (sub-scanning direction). The belt roller 7 is a driving roller that rotates clockwise in FIG. The belt roller 6 is a driven roller that rotates clockwise in FIG. 1 as the conveyor belt 8 travels as the belt roller 7 rotates.

  The outer peripheral surface of the conveyance belt 8 has adhesiveness by being subjected to silicone treatment. A nip roller 4 is disposed at a position facing the belt roller 6 with the conveyance belt 8 interposed therebetween on the paper conveyance path. The nip roller 4 presses the sheet fed from the sheet feeding cassette 31 against the outer peripheral surface of the conveyance belt 8. The sheet pressed against the outer peripheral surface of the conveying belt 8 is conveyed rightward in FIG. 1 while being held on the outer peripheral surface by the adhesive force of the outer peripheral surface.

  A peeling plate 5 is provided on the side of the belt roller 7 on the downstream side in the conveying direction. The peeling plate 5 peels the paper held on the outer peripheral surface of the conveyor belt 8 from the outer peripheral surface. On the paper conveyance path from the conveyance mechanism 21 to the standby units 40a and 40b in the housing 10, the conveyance guides 29a, 29b and 33 extending while curving from the conveyance mechanism 21 toward the standby units 40a and 40b, and the conveyance A pair of rollers 28a and 28b disposed between the guides 29a, 29b and 33 is provided. A pair of rollers 35a and 35b is provided at the leading end of the conveyance guide 33 on the downstream side in the conveyance direction. One roller of the roller pair 28a, 28b, 35a, 35b is a driving roller that is rotated by a feed motor (not shown), and the other roller is a driven roller that rotates as the one roller rotates. Further, on the sheet conveyance path from the conveyance mechanism 21 to the standby units 40c and 40d in the housing 10, conveyance guides 29c, 58 and 61 branched from the conveyance guide 29b and a roller pair 59 are provided.

  The sheet peeled off from the outer peripheral surface of the transport belt 8 by the peeling plate 5 is guided upward by the transport guides 29a and 29b and fed upward while being sandwiched between the roller pairs 28a and 28b during double-sided printing. Thereafter, the sheet sent upward is guided by the conveyance guide 33 and selectively conveyed to one of the two standby units 40a and 40b. Further, the sheet peeled from the outer peripheral surface of the transport belt 8 by the peeling plate 5 is sent downward while being guided by the transport guide 29c during single-sided printing. A branch plate having the same configuration as a branch plate 34 to be described later is provided at a branch point between the conveyance guide 29b and the conveyance guide 29c, and the sheet conveyed from the conveyance mechanism 21 is either the conveyance guide 29a or the conveyance guide 29c. It is possible to selectively convey the material.

  As shown in FIG. 2, the conveyance guide 33 receives the branch guides 33 a and 33 b branched from the conveyance mechanism 21 toward the two standby units 40 a and 40 b from the middle part into two, and the sheet sent from the conveyance guide 29 a. And a branch plate 34 that distributes to one of the two branch guides 33a and 33b.

  The branch plate 34 extends from the tip end portion 33 c where the two branch guides 33 a and 33 b intersect to the side wall of the conveyance guide 33. The branch plate 34 is provided so as to be able to swing from the position of the solid line shown in FIG. 2 to the position of the broken line by driving a sorting motor 134 (see FIG. 4) with one end contacting the tip 33c as an axis. When the branch plate 34 is at the position of the solid line shown in FIG. 2, the sheet fed from the transport guide 29a is guided by the branch guide 33a and is sandwiched by the roller pair 35a. It is conveyed to the standby unit 40a located above. When the branch plate 34 is at the position of the broken line shown in FIG. 2, the sheet fed from the transport guide 29a is guided by the branch guide 33b and is sandwiched between the roller pair 35b, and the two standby units 40a and 40b. Are transferred to a standby unit 40b located below. In addition, the branch plate 34, the distribution motor 134, and the motor driver 124 described later in the present embodiment correspond to the second distribution mechanism in the present invention.

  Also, one drive roller of the roller pair 28a, 28b, 35a, 35b is a switchback roller, and rotates in the direction opposite to the rotation direction when it is fed from the conveyor belt 8 and conveyed to the standby units 40a, 40b. It is possible. The roller pair 28a, 28b, 35a, 35b rotates in the opposite direction while the trailing edge of the sheet conveyed to one of the standby units 40a, 40b is held between the roller pair 35a or the roller pair 35b, so that the sheet is Switched back to the lower conveyance guide 58 and sent. The sheet sent to the conveyance guide 58 is guided by the conveyance guide 61 while being nipped by the roller pair 59 and is conveyed to the two standby units 40 c and 40 d or is conveyed again to the conveyance mechanism 21.

  As shown in FIG. 3, the conveyance guide 61 is divided into three branch guides 61 a to 61 c that are branched from the middle part toward the downstream side in the conveyance direction, and three branch guides 61 a to 61 c that are fed from the conveyance guide 58. There are two branch plates 62a and 62b that are distributed to either of them.

  The branch plate 62a extends from the tip 61d where the two branch guides 61a and 61b intersect to the side wall of the transport guide 61. The branch plate 62a is provided so as to be swingable from the position of the solid line shown in FIG. 3 to the position of the broken line by driving a sorting motor 135 (see FIG. 4) with one end contacting the tip portion 61d as an axis.

  The branch plate 62b extends from the front end 61e where the two branch guides 61a and 61c intersect to the side wall of the transport guide 61. The branch plate 62b is provided so as to be able to swing from the position of the solid line shown in FIG. 3 to the position of the broken line by driving a sorting motor 136 (see FIG. 4) with one end contacting the tip 61e as an axis.

  When the branch plate 62b is at the position of the broken line shown in FIG. 3, the sheet sent from the conveyance guide 58 is conveyed again to the conveyance mechanism 21 via the retransmission path 60 described later. In addition, when the branch plate 62a is at the position of the solid line shown in FIG. 3 and the branch plate 62b is at the position of the solid line shown in FIG. 3, the sheet sent from the conveyance guide 58 is sent to the two standby units 40c and 40d. Of these, it is transported to the standby unit 40c located above. Further, when the branch plate 62a is at the position of the broken line shown in FIG. 3 and the branch plate 62b is at the position of the solid line shown in FIG. 3, the sheet sent from the conveyance guide 58 is sent to the two standby units 40c and 40d. Of these, it is transported to the standby unit 40d located below. Note that the branch plates 62a and 62b, the sorting motors 135 and 136, and motor drivers 125 and 126 described later correspond to the first sorting mechanism in the present invention.

  The retransmission path 60 includes conveyance guides 63a to 63d and roller pairs 64a to 64d arranged between the conveyance guides 63a to 63d. One roller of the roller pairs 64a to 64d is a driving roller that is rotated by a feed motor (not shown), and the other roller is a driven roller that rotates as the one roller rotates. The conveyance guide 63d merges with the conveyance guide 27c. The sheet conveyed from the retransmission path 60 to the conveyance mechanism 21 is opposite to the sheet conveyed from the paper feed cassette 31 to the conveyance mechanism 21 and is opposed to the inkjet head 2, and can be printed on both sides of the sheet. .

  Returning to FIG. 1, the standby unit 40 is arranged in a plurality of pairs of rollers 41 arranged in the sub-scanning direction and two in the vertical direction, and arranged in the sub-scanning direction between the plurality of roller pairs 41. It has a plurality of heating wires 42 (drying means). The sheet conveyed to the standby unit 40 is sandwiched by a plurality of roller pairs 41 and is held substantially flat along the sub-scanning direction. The inside of the standby unit 40 is heated by heat generated by applying a voltage to the heating wire 42, and the sheet conveyed to the standby unit 40 and sandwiched between the roller pair 41 is substantially along the sub-scanning direction. Dry on a flat surface. One roller of the roller pair 41 (a roller that comes into contact with the surface of the sheet on which the image has been recorded immediately before) is a spur roller so that ink that has not completely penetrated the surface on which the image of the sheet has been recorded does not easily adhere. ing.

  Thereby, the paper on which the image is recorded can be quickly dried by the heat generated by the heating wire 42, the ink can be quickly penetrated into the paper, and the curling of the paper can be prevented. In addition, the standby time in the standby unit 40 can be shortened compared to the case where the heating wire 42 is not provided. Furthermore, the heat generated by the heating wire 42 tends to flow upward. Therefore, the standby units 40 a and 40 b provided with the heating wire 42 are arranged above the inkjet head 2, so that the discharge effect of the inkjet head 2 due to the heat generated by the heating wire 42 can be reduced. In addition, the standby units 40c and 40d provided with the heating wire 42 are disposed at positions below the inkjet head 2 with the paper feed cassette 31 interposed therebetween, so that the inkjet head due to heat generated by the heating wire 42 is provided. 2 can be reduced.

  The side wall 10a which is a part of the housing 10 is detachable from the housing 10 along the sub-scanning direction together with the transport guide 61 and the two standby units 40c and 40d. Further, the side wall 10b, which is a part of the housing 10, can rotate around the shaft 10c extending in the main scanning direction together with the conveyance guide 33 and the roller pairs 35a and 35b. The two standby units 40a and 40b can be attached to and detached from the housing 10 along the sub-scanning direction through a space formed by rotating the side wall 10b, the conveyance guide 33, and the roller pair 35a and 35b clockwise. ing. If the attaching / detaching direction of the standby unit 40 is the main scanning direction, the sheet remaining between the inside of the housing 10 and the extracted standby unit 40 is torn when the standby unit 40 is extracted. However, since the attaching / detaching direction of the standby unit 40 is the transport direction (sub-scanning direction), when the standby unit 40 is removed from the housing 10, the paper remaining in the housing 10 is easy to see. Jam processing is easy.

  The sheet which is switched back and guided downward by the conveyance guide 58 and being nipped by the roller pair 59 passes through one of the standby units 40 c and 40 d and is discharged to the discharge tray 80. The paper discharge tray 80 protrudes from the housing 10 and is disposed on the side of the standby units 40c and 40d along the sub-scanning direction. The plurality of sheets on which the images are recorded and discharged are discharged onto the discharge tray 80 at the sides along the sub-scanning direction of the standby units 40c and 40d. Since the paper discharge tray 80 protrudes from the housing 10, it is easy to take out the paper.

  Each of the four inkjet heads 2 has a discharge surface 2a on which a plurality of nozzles for discharging ink are formed. Each of the four inkjet heads 2 extends along the main scanning direction orthogonal to the sub scanning direction, and is arranged in parallel in the sub scanning direction. Then, it is supported by the housing 10 via the frame 3. That is, the inkjet printer 1 is a line-type color inkjet printer that is fixed in the main scanning direction and can be printed on both sides of the paper. Since the four inkjet heads 2 are arranged in the sub-scanning direction, high-speed printing on a sheet can be performed.

  The maintenance unit 50 performs a purge operation for recovering the ejection operation of the inkjet head 2 that has fallen into an ejection failure and the wiping operation for the ejection surface 2 a of the inkjet head 2. The maintenance unit 50 includes four caps 52 arranged in parallel in the sub-scanning direction at the same interval as the four inkjet heads 2, a tray 51 that urges the four caps 52 upward via a spring (not shown), A movable plate 53 that can be moved along the main scanning direction over the four caps 52 via two springs (not shown) arranged with the two caps 52 interposed therebetween, and four caps arranged on the upper surface of the movable plate 53 52 and a wiper 54 made of an elastic material such as rubber, which is slightly longer than the length in the sub-scanning direction.

  When maintenance of the inkjet head 2 is not performed, the maintenance unit 50 stands still in a standby state at a retracted position that does not face the side inkjet head 2 along the sub-scanning direction of the inkjet head 2. When this maintenance is not performed, the movable plate 53 and the wiper 54 are located outside the end of the cap 52 in the main scanning direction.

  When performing maintenance, first, the inkjet head 2 is raised by a lifting mechanism (not shown) until the ejection surface 2 a of the inkjet head 2 is positioned higher than the tip of the wiper 54. Then, the maintenance unit 50 is moved horizontally from the retracted position to the maintenance position facing the inkjet head 2 by a moving mechanism (not shown). Thereafter, the inkjet head 2 is lowered by the lifting mechanism, and the cap 52 is brought into contact with the peripheral portion of the ejection surface 2 a of the inkjet head 2.

  In this manner, the cap 52 and the peripheral portion of the ejection surface 2a abut on each other, thereby improving the airtightness of the sealed space surrounded by the cap 52 and the ejection surface and preventing the ink in the nozzle from drying. Further, a purge operation in which ink is forcibly ejected from the inkjet head 2 by bringing the cap 52 into contact with the peripheral portion of the ejection surface 2a of the inkjet head 2 and sucking the sealed space to a negative pressure with a suction pump (not shown). I do. The ink accumulated in the cap 52 is discharged to a waste liquid tank through a hole (not shown) formed on the bottom surface of the cap 52.

  After completion of the purge operation, the inkjet head 2 is raised by the elevating mechanism to a position where the ejection surface 2a of the inkjet head 2 slightly contacts the tip of the wiper 54. Then, by moving the movable plate 53 from one end to the other end of the cap 52 in the main scanning direction by a horizontal movement mechanism (not shown), the wiper 54 is moved in the sub-scanning direction while being in contact with the ejection surface 2a of the inkjet head 2. A wiping operation for wiping off ink adhering to the ejection surface 2a is performed.

  A substantially rectangular parallelepiped platen 19 is disposed in the loop of the conveyor belt 8 so as to face the four inkjet heads 2 and the maintenance unit 50. The upper surface of the platen 19 is in contact with the inner peripheral surface of the upper loop of the conveyor belt 8 and supports it from the inner peripheral side of the conveyor belt 8. Thereby, the outer peripheral surface of the upper loop of the conveyor belt 8 and the lower surface of the inkjet head 2 are parallel to each other, and a slight gap is formed between the lower surface of the inkjet head 2 and the outer peripheral surface of the conveyor belt 8. Is done. The gap constitutes a part of the paper transport path. When the paper transported while being held on the outer peripheral surface of the transport belt 8 sequentially passes immediately below the four inkjet heads 2, ink of each color is ejected toward the upper surface of the paper, thereby Thus, a desired color image is formed.

  The four inkjet heads 2 are connected to four ink tanks 71 arranged along the sub-scanning direction in the ink tank cassette 70. That is, the four ink tanks 71 store the ink of the corresponding color of the inkjet head 2, and ink is supplied from each ink tank 71 to the inkjet head 2 via a tube (not shown).

  A manual feed tray 85 is disposed on the side of the conveyance guide 27c across the side wall of the housing 10. The sheet fed from the manual feed tray 85 is guided to the transport guide 86 that joins the transport guide 27 c and is transported to the transport mechanism 21 while being sandwiched by the roller pair 87. Since the manual feed tray 85 and the paper discharge tray 80 are in a position where they overlap each other in the vertical direction, the inkjet printer 1 can be downsized.

  A scanner (reading unit) 90 is provided above the standby units 40a and 40b. The scanner 90 includes a flat reading surface 91 made of a glass plate, a reading unit 92 that reads an image of a sheet placed on the reading surface 91, and a cover 93 that covers the reading surface 91. Then, the scanner 90 reads an image on the sheet with the reading unit 92 in a state where the cover 93 is closed after the sheet on which the image is formed is placed on the reading surface 91.

  Next, the control system of the inkjet printer 1 will be described with reference to FIG. FIG. 4 is a block diagram of the ink jet printer shown in FIG. The control unit 100 includes a CPU (Central Processing Unit) that is an arithmetic processing unit, a ROM (Read Only Memory) that stores a control program executed by the CPU and data used for the control program, and data when the program is executed. RAM (Random Access Memory) for temporary storage. These function as a head control unit 101, a conveyance control unit 102, a standby determination unit 103, a drying control unit 104, a first distribution control unit 105, a second distribution control unit 106, and the like.

  The head control unit 101 controls the head drive circuit 121 so that ink is ejected from the corresponding inkjet head 2 based on the image recording data on the paper received from the PC 200.

  The conveyance control unit 102 controls the motor driver 122 so that the sheet feeding roller 32 is rotated by driving the sheet feeding motor 132 and the uppermost sheet in the sheet feeding cassette 31 is sent out onto the conveying belt 8. The motor driver 123 is controlled so that the belt roller 7 is rotated by driving the conveyance motor 133 and the sheet is conveyed while being held on the conveyance belt 8.

  The standby determination unit 103 determines whether it is necessary to hold and stop the paper on which the image is recorded by the inkjet head 2 in the standby unit 40 based on the recording data of the image on the paper received from the PC 200. Specifically, the amount of ink ejected from the inkjet head 2 is calculated from the recording data of the image on the paper received from the PC 200, and the standby time to be held and stopped by the standby unit 40 is determined according to the ink amount. . When the ink amount is larger than the predetermined amount, the standby time is increased in proportion to the predetermined time that the standby unit 40 holds and stops when the ink amount is the predetermined amount. When the ink amount is smaller than the predetermined amount, it is determined that it is not necessary to hold and stop the ink in the standby unit 40.

  The drying control unit 104 applies heat to the heating wire 42 to generate heat when it is determined by the standby determination unit 103 that the standby unit 40 needs to hold and stop the paper on which the image is recorded, The inside of the standby unit 40 is kept in a high temperature environment.

  The first distribution control unit 105 swings the branch plate 34 by driving the distribution motor 134 so as to selectively distribute the sheet conveyed from the conveyance mechanism 21 to one of the two standby units 40a and 40b. The motor driver 124 is controlled.

  The second distribution control unit 106 swings the branch plates 62a and 62b by driving the distribution motors 135 and 136, and switches back the paper conveyed from the conveyance guide 58 to the two standby units 40c and 40d. Alternatively, the motor drivers 125 and 126 are controlled so as to be selectively distributed to any one of the retransmission paths 60.

  Next, a paper transport operation during single-sided printing will be described. First, the inkjet printer 1 drives the paper feed motor 132 under the control of the transport control unit 102 and rotates the paper feed roller 32, thereby transporting the uppermost paper in the paper feed cassette 31 to the transport guides 27 a to 27 c. And is conveyed to the conveyance mechanism 21 while being sandwiched between the roller pairs 26a and 26b and the separation roller pair 26c. When the paper on which an image is to be recorded is different in size from the paper in the paper feed cassette 31, the ink jet printer 1 drives a motor (not shown) under the control of the transport control unit 102, so that one of the roller pair 87 By rotating the drive roller, the paper on the manual feed tray 85 is guided to the transport mechanism 21 while being guided by the transport guides 27a, 27b, 87 and being sandwiched by the roller pairs 26a, 26b, 86.

  Then, the inkjet printer 1 controls the head drive circuit 121 to eject ink from the inkjet head 2 onto a sheet conveyed on the conveyance belt 8 and record a desired image on the sheet. Thereafter, the ink jet printer 1 conveys the sheet on which the image is recorded while being guided by the conveyance guide 29c.

  The ink jet printer 1 determines whether or not the standby unit 40c holds and stops the paper on which the image is recorded by the standby determination unit 103 until the paper is fed and the image is recorded on the paper. . When it is determined by the standby determination unit 103 that it is necessary to hold and stop the inkjet printer 1, the second distribution control unit 106 shows the branch plates 62a and 62b arranged on the conveyance guide 61 in FIG. The sheet is moved to the position of the solid line, and the sheet guided by the conveyance guide 29c and conveyed downward is guided by the conveyance guide 61a and conveyed to the standby unit 40c while being nipped by the roller pair 59. Thereafter, the ink jet printer 1 holds and stops the paper by the standby unit 40c for a predetermined standby time.

  Since the standby unit 40c is maintained in a high temperature environment by the heat generated by the heating wire 42, the sheet on which the image is recorded dries. When a predetermined standby time has elapsed, the inkjet printer 1 discharges the paper held in the standby unit 40 c to the paper discharge tray 80.

  Further, when the standby determination unit 103 determines that it is not necessary to wait, the inkjet printer 1 shows the branch plates 62a and 62b arranged on the transport guide 61 by the second distribution control unit 106 as shown in FIG. The sheet is moved to the position of the solid line, and the sheet guided by the conveyance guide 29c and conveyed downward is guided by the conveyance guide 61a and conveyed to the standby unit 40c. To discharge. In this way, the standby determination unit 103 determines whether or not the paper is held by the standby unit 40 and is stopped, and if it is not necessary to stop the paper, the paper is allowed to pass without being stopped by the standby unit 40. Thus, the standby of the paper in the standby unit 40 can be minimized.

  The recording of the image on the second and subsequent sheets is performed as described above, but the waiting time of the first sheet has not elapsed, and the first sheet held in the standby unit 40c is still discharged. If not, the inkjet printer 1 causes the second distribution control unit 106 to move the branch plate 62a disposed on the conveyance guide 61 to the position of the broken line shown in FIG. 3, and the branch plate 62b to the solid line shown in FIG. The sheet on which the second image is recorded is guided by the conveyance guide 61b and conveyed to the standby unit 40d. If there is one standby unit 40 and a sheet preceding the standby unit 40 is held, the next sheet cannot be held in the standby unit 40 until the sheet is discharged from the standby unit 40. . Therefore, by arranging a plurality of standby units 40 and selectively distributing the paper to any of the plurality of standby units 40 by the branch plates 62a and 62b, high-speed conveyance is possible.

  Next, a paper transport operation during duplex printing will be described. In the present embodiment, it is assumed that the standby determination unit 103 determines that all sheets on which images have been recorded need to be standby by the standby unit 40.

  First, the inkjet printer 1 drives the paper feed motor 132 under the control of the transport control unit 102 and rotates the paper feed roller 32, thereby transporting the uppermost paper in the paper feed cassette 31 to the transport guides 27 a to 27 c. And is conveyed to the conveyance mechanism 21 while being sandwiched between the roller pairs 26a and 26b and the separation roller pair 26c. When the paper on which an image is to be recorded is different in size from the paper in the paper feed cassette 31, the ink jet printer 1 drives a motor (not shown) under the control of the transport control unit 102, so that one of the roller pair 87 By rotating the drive roller, the paper on the manual feed tray 85 is guided to the transport mechanism 21 while being guided by the transport guides 27a, 27b, 87 and being sandwiched by the roller pairs 26a, 26b, 86.

  Then, the ink jet printer 1 controls the head driving circuit 121 to eject ink from the ink jet head 2 onto the surface opposite to the ejection surface 2a of the first sheet conveyed on the conveying belt 8, and the first sheet A desired image is recorded on the surface of the paper. Thereafter, the ink jet printer 1 conveys the first sheet on which the image is recorded on the front surface thereof while being guided by the conveyance guides 29a and 29b and sandwiched by the roller pairs 28a and 28b.

  Next, the inkjet printer 1 moves the branch plate 34 disposed on the conveyance guide 33 to the position indicated by the solid line shown in FIG. 2 by the first distribution control unit 105, and guides the first sheet with the conveyance guide 33a. Then, it is conveyed to the standby unit 40a while being sandwiched by the roller pair 35a. Thereafter, the inkjet printer 1 holds the first sheet for a predetermined waiting time in the standby unit 40a in a state where the trailing edge of the first sheet conveyed to the standby unit 40a is sandwiched between the roller pair 35a. Then stop. Since the inside of the standby unit 40a is maintained in a high-temperature environment by heat generated by the heating wire 42, the sheet on which the image is recorded on the first surface is dried.

  While the first sheet is held by the standby unit 40a, the inkjet printer 1 feeds the second sheet from the sheet feeding cassette 31, and the surface of the second sheet is similar to that described above. A desired image is recorded by operation. Thereafter, the ink jet printer 1 conveys the second sheet on which the image is recorded with the conveyance guides 29a and 29b and conveys it upward while being sandwiched between the roller pairs 28a and 28b.

  Next, the inkjet printer 1 moves the branch plate 34 disposed on the conveyance guide 33 to the position indicated by the broken line shown in FIG. 2 by the first distribution control unit 105, and guides the second sheet with the conveyance guide 33b. Then, it is conveyed to the standby unit 40b while being sandwiched by the roller pair 35b. Thereafter, the inkjet printer 1 holds the second sheet in the standby unit 40b for a predetermined waiting time while the trailing edge of the second sheet conveyed to the standby unit 40b is held between the roller pair 35b. Then stop. Since the inside of the standby unit 40b is maintained in a high temperature environment by the heat generated by the heating wire 42, the sheet on which the image is recorded on the surface of the second sheet is dried.

  While the second sheet is held by the standby unit 40b and a desired image is recorded on the surface of the third sheet fed from the sheet feeding cassette 31 by the same operation as described above, In the inkjet printer 1, the first distribution control unit 105 moves the branch plate 34 to the position indicated by the solid line in FIG. 2, and the first sheet held in the standby unit 40a is conveyed by the conveyance guides 29a, 29b, and 33a. The sheet is guided by the roller pair 28 a, 28 b, 35 a and switched back and conveyed to the conveyance guide 58.

  Thereafter, the inkjet printer 1 conveys the third sheet to the standby unit 40a while being guided by the conveyance guide 33a and sandwiched by the roller pair 35a. The ink jet printer 1 holds and stops the third sheet with the standby unit 40a in a state where the trailing edge of the third sheet conveyed to the standby unit 40a is held between the roller pair 35a.

  Next, the inkjet printer 1 moves the branch plate 62b arranged in the conveyance guide 61 to the position indicated by the broken line shown in FIG. 3 by the second distribution control unit 106, and is guided by the conveyance guide 58 and conveyed downward. Are transported again to the transport mechanism 21 while being guided by the transport guides 63a to 63d and sandwiched between the roller pairs 64a to 64d. Then, the back surface of the first sheet faces the ejection surface 2 a of the inkjet head 2. Thereafter, the ink jet printer 1 conveys the sheet on which the desired image is recorded on the back surface of the first sheet to the conveyance guide 58 while being guided by the conveyance guide 29c.

  Then, the inkjet printer 1 moves the branch plate 62a to the position indicated by the solid line shown in FIG. 3 by the second distribution control unit 106, moves the branch plate 62b to the position indicated by the solid line, and is guided by the conveyance guide 58 and conveyed downward. The first sheet is guided by the transport guide 61a and transported to the standby unit 40c. Thereafter, the ink jet printer 1 holds and stops the paper by the standby unit 40c for a predetermined standby time.

  Thereafter, while the third sheet is held by the standby unit 40a and a desired image is recorded on the surface of the fourth sheet fed from the sheet feeding cassette 31 by the same operation as described above, In the inkjet printer 1, the first distribution control unit 105 moves the branch plate 34 to the position of the broken line shown in FIG. 2, and the second sheet held in the standby unit 40b is conveyed by the conveyance guides 29a, 29b, and 33b. It is guided back and switched by the roller pair 28a, 28b, 35b while being switched back and conveyed to the conveyance guide 58.

  Thereafter, the inkjet printer 1 conveys the fourth sheet to the standby unit 40b while being guided by the conveyance guide 33b and sandwiched by the roller pair 35b. The inkjet printer 1 holds and stops the third sheet in the standby unit 40b in a state where the trailing edge of the fourth sheet conveyed to the standby unit 40b is sandwiched between the roller pair 35b.

  Next, the inkjet printer 1 moves the branch plate 62b arranged in the conveyance guide 61 to the position indicated by the broken line shown in FIG. 3 by the second distribution control unit 106, and is guided by the conveyance guide 58 and conveyed downward. Are transported again to the transport mechanism 21 while being guided by the transport guides 63a to 63d and sandwiched between the roller pairs 64a to 64d. Then, the back surface of the second sheet faces the ejection surface 2 a of the inkjet head 2. Thereafter, the inkjet printer 1 conveys the sheet on which the desired image is recorded on the back surface of the second sheet to the conveyance guide 58 while being guided by the conveyance guide 29c.

  Then, the inkjet printer 1 moves the branch plate 62a to the position indicated by the broken line shown in FIG. 3 by the second distribution control unit 106, moves the branch plate 62b to the position indicated by the solid line, and is guided downward by the transport guide 58 and transported downward. The second sheet thus fed is guided by the conveyance guide 61b and conveyed to the standby unit 40d. Thereafter, the ink jet printer 1 holds and stops the sheet by the standby unit 40d for a predetermined standby time.

  Then, the inkjet printer 1 discharges the first sheet held by the standby unit 40 c to the discharge tray 80. By continuing such an operation, the inkjet printer 1 according to the present embodiment can perform duplex printing on a plurality of sheets. Further, the standby units 40a and 40b can be used as a space for switching back and transporting the paper to the retransmission path 60 during duplex printing.

  In the double-sided printing described above, the standby determination unit 103 determines that the standby unit 40 needs to wait for all sheets on which images are recorded. However, the standby unit 40 does not need to wait. If it is included, only the sheet is transported to the transport mechanism 21 without being stopped by the standby unit 40 or discharged to the paper discharge tray 80.

  As described above, in the inkjet printer 1 of the present embodiment, the inkjet head 2 and the maintenance unit 50 are arranged side by side in the sub-scanning direction, and below that, the standby units 40c and 40d and the paper discharge tray 80 are in the sub-scanning direction. Since they are arranged side by side, the apparatus can be miniaturized in the sub-scanning direction.

  Next, modified examples in which various modifications are added to the above-described embodiment will be described. However, about the thing which has the structure similar to this embodiment mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

  In the above-described embodiment, the heating unit 42 is provided in the standby unit 40 in order to shorten the drying time of the paper. However, if a long drying time can be secured, the heating unit 42 is not provided in the standby unit 40. May be.

  In addition to the heating wire 42, a heater such as a halogen heater, a far infrared heater, or a near infrared heater is provided on the side of the standby unit 40 in the main scanning direction, and heat generated by driving the heater is supplied from the fan. The paper may be dried by being applied to the paper by an air current.

  Furthermore, when the standby time in the standby unit 40 takes a long time or when it is desired to perform the printing operation quickly, the number of standby units may be increased. If there is one standby unit 40 and a sheet preceding the standby unit 40 is held, the next sheet cannot be held in the standby unit 40 until the sheet is discharged to the paper discharge unit. . Therefore, by arranging a plurality of standby units 40 and selectively distributing the sheets to any one of the plurality of standby units 40 by the branch plate, the number of sheets that can be kept on standby increases and high-speed conveyance becomes possible. That is, the number of standby units may be one or more depending on the standby time and the printing operation.

  Further, the control unit 100 may not have the standby determination unit 103, and the standby unit 40 may always wait for the paper. Thereby, control by the control part 100 becomes easy.

  The standby units 40a and 40b, which are the second standby units, are arranged above the inkjet head 2, and do not extend in the horizontal direction, but may extend in the vertical direction in the middle of the conveyance guide 29a. However, considering the downsizing of the printer and the curl prevention efficiency of the paper, the extending direction of the standby units 40a and 40b is preferably the horizontal direction.

  Furthermore, the present invention is not limited to the ink jet printer as in the above-described embodiment, and can be applied to various apparatuses as long as it is an image recording apparatus.

1 is a schematic cross-sectional view of an ink jet printer according to an embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view of a conveyance guide that conveys a sheet upward. FIG. 6 is an enlarged cross-sectional view of a conveyance guide that conveys a sheet downward. 1 is a block diagram of an inkjet printer according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Inkjet head 21 Conveyance mechanism 40 Standby unit 50 Maintenance unit 80 Paper discharge tray

Claims (11)

A recording head for recording an image on a recording medium;
A transport mechanism facing the recording head and transporting a recording medium along a substantially horizontal transport direction;
In a standby state, a maintenance unit that is disposed on a side of the recording head along the transport direction and that maintains the recording head;
A first standby unit that is disposed below the recording head and holds the recording medium on which an image is recorded by the recording head substantially flatly along the transport direction and stops;
An image recording apparatus comprising: a discharge unit disposed on a side of the first standby unit along the transport direction and on which a recording medium on which an image is recorded by the recording head is stacked. A plurality of the first standby parts are arranged in the vertical direction,
In a transport path between the plurality of first standby units and the recording head, a first medium that selectively distributes a recording medium on which an image is recorded by the recording head to one of the plurality of first standby units. The image recording apparatus according to claim 1, wherein a minute mechanism is arranged.   The image recording apparatus according to claim 1, wherein the first standby unit includes a drying unit that dries a recording medium on which an image is recorded by the recording head.   The image recording apparatus according to claim 1, wherein a plurality of the recording heads are arranged along the transport direction. The apparatus further includes a housing in which the transport mechanism, the recording head, and the first standby unit are arranged.
The image recording apparatus according to claim 1, wherein the first standby unit is detachable from the housing. The apparatus further includes a housing in which the transport mechanism, the recording head, and the standby unit are arranged.
The image recording apparatus according to claim 1, wherein the discharge unit protrudes from the housing. Based on the recording data of the image on the recording medium, there is further provided a determination means for determining whether or not it is necessary to hold and stop the recording medium on which the image is recorded by the recording head in the first standby unit. ,
When the determination unit determines that the recording medium needs to be stopped by the first standby unit, the recording medium is held and stopped by the first standby unit, and when it is determined that the recording medium is unnecessary, the recording medium is The image recording apparatus according to claim 1, wherein the image recording apparatus allows the first standby unit to pass without stopping.   The image recording apparatus according to claim 1, wherein a reading unit that reads an image recorded on a recording medium is disposed above the recording head.   The recording medium can be accommodated, and a supply unit that supplies the recording medium to the transport mechanism is disposed below the recording head and above the first standby unit. The image recording apparatus of any one of -8. A retransmission path for re-sending the recording medium conveyed by the conveyance mechanism to the conveyance mechanism;
A second standby unit that is disposed above the recording head and that holds and stops the recording medium on which the image is recorded by the recording head substantially flat; and
2. The double-sided printing on a recording medium, wherein the recording medium on which an image is recorded by the recording head is once transported to the second standby unit, and then switched back and transported to the retransmission path. 10. The image recording apparatus according to any one of items 9. A plurality of the second standby parts are arranged along the vertical direction,
In a transport path between the plurality of second standby units and the recording head, a second medium that selectively distributes a recording medium on which an image is recorded by the recording head to one of the plurality of second standby units. The image recording apparatus according to claim 10, wherein a minute mechanism is arranged.

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