JP2010149443A - Image recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording apparatus capable of preventing the leading end of a recording paper from coming in contact with a recording head. <P>SOLUTION: The recording paper on which an image is recorded is guided onto a paper feed tray 20 through a reverse guiding path 67 branching from a paper discharge path 66, and fed by a paper feed roller 25 to a recording part 24 again. Curved paths 65A, 65B and 65C are disposed in a portion from the paper feed tray 20 to the recording part 24, a guide flap 70 is disposed in a connection part 37 between each of the curved paths and the paper feed tray 20. The guide flap 70 is positioned in one of first, second and third positions P1, P2 and P3 by a control part 84 in accordance with the rigidity of the recording paper. The recording paper on which the image is recorded is conveyed in one of the curved paths guided by the guide flap 70. The recording paper is halted at a second stop position in the curved path, during the halt, the leading end of the recording paper is curved toward the platen 42 (facing down). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording roller that contacts a recording sheet stacked on a tray and feeds the recording sheet, and a recording that records an image by ejecting ink onto the recording sheet fed by the feeding roller. The present invention relates to an image recording apparatus including a head and capable of recording an image on both a first surface and a second surface of a recording sheet by the recording head.

  2. Description of the Related Art Conventionally, ink jet type image recording apparatuses capable of recording images on both sides of a recording sheet are known. For example, in Patent Document 1, a recording sheet on which an image is recorded is switched back on the downstream side of the recording head, and the recording sheet is returned to a paper feed tray provided on the lower side of the recording head before the recording head. And a mechanism for recording an image on the back surface of the recording paper.

JP 2007-145574 A

  However, the recording paper on which the image is recorded on the surface may be curled downward at the end in the transport direction due to the influence of the adhered ink. The image recording apparatus described in Patent Document 1 is configured such that the front surface and the back surface are reversed when the recording paper passes through the curved path. Therefore, when a recording sheet having an image recorded on the surface is fed to the recording head side through the curved path, the recording sheet is sent to the recording head with the curl direction facing upward. In this case, there is a problem that the leading edge of the recording paper comes into contact with the recording head and the recording paper is stained with ink. In some cases, the recording paper may be damaged or clogged.

  Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide an image recording apparatus capable of preventing contact between the leading end of a recording sheet and a recording head.

(1) In order to achieve the above object, the present invention provides a feeding roller that feeds the recording paper by rotating while contacting the recording paper contained in the tray, and a feeding roller that feeds the recording paper. And a recording head that records an image by ejecting ink onto the recording sheet, and is configured as an image recording apparatus capable of recording images on both the first and second surfaces of the recording sheet by the recording head. . The image recording apparatus is formed so that a recording sheet can be guided toward the recording head so that a surface opposite to the surface on which the feeding roller contacts is opposed to the recording head, and a plurality of curves having different curvatures are provided. A path, a return path for returning a recording sheet on which an image is recorded on the first surface by the recording head, to the upstream side of the plurality of curved paths, and a connecting portion between the plurality of curved paths and the return path. And a guide flap for guiding the recording sheet passing through the return path to any one of the plurality of curved paths, and a recording sheet fed into the return path after recording an image on the first surface. Before entering one of the plurality of curved paths, there is a rigidity determining means for determining the rigidity of the recording paper, and a curvature rate corresponding to the rigidity determined by the rigidity determining means from the plurality of curved paths. You A path determining means for determining one curved path, a flap control means for operating the guide flap so that the recording sheet is conveyed to the curved path determined by the path determining means, and an image is recorded on the second surface. Stop means for temporarily stopping the recording paper for a first predetermined time in the curved path determined by the path determining means before the recording paper reaches the recording head.

  According to this configuration, the recording paper accommodated in the tray is fed by the feeding roller, passes through one of the curved paths formed in a curved shape, reaches the recording head, and is recorded by the recording head. An image is recorded on one side. Then, the recording sheet on which the image is recorded on the first surface is conveyed to the upstream side of the plurality of curved paths through the return path. The guide flap is provided at a connecting portion between each curved passage and the return passage. This guide flap is operated by the flap control means so that the recording sheet passes through the curved path determined by the path determination means. The passage determining means determines a curved passage having a curvature corresponding to the rigidity determined by the rigidity determining means. For example, when the recording sheet being conveyed has a high rigidity, the recording sheet tends to have a small curl, so a curved path having a small curvature, that is, a gentle curve is determined. On the other hand, when the recording paper has a low rigidity, the recording paper tends to have a large curl. Therefore, a curved path having a large curvature, that is, a tight curve is determined.

  The recording sheet returned to the upstream side of the plurality of curved paths is guided by the guide flap operated by the flap control means and enters the curved path determined by the path determining means. At this time, the recording unit temporarily stops the recording sheet in the curved path determined by the path determination unit for a first predetermined time. As a result, the leading edge of the recording paper that has been curled to the recording head side when an image is recorded on the first surface is curled toward the side opposite to the recording head. This curling is performed by temporarily stopping the recording paper in the curved path for a first predetermined time in a deformed state, so that a new physical configuration is provided for curling. There is no need for mounting, and the leading edge of the recording paper can be curled with a simple configuration without increasing the size of the apparatus.

  Furthermore, in the image recording apparatus of the present invention, curling is performed in a curved path corresponding to the rigidity of the recording paper, so that the optimal curling can be applied to all the recording papers regardless of the rigidity.

(2) The path determining means has a second threshold value determined with respect to the curvature when the rigidity of the recording paper on which the image is recorded on the second surface is larger than the first threshold value determined with respect to the rigidity of the recording paper. It is preferable to determine a curved path having a small curvature. The path determining means determines a curved path having a curvature greater than the second reference value when the rigidity of the recording paper on which the image is recorded on the second surface is smaller than the first threshold. It is preferable that

(3) The image recording apparatus of the present invention further includes an electric motor that applies a rotational force to the feeding roller. In this configuration, it is preferable that the rigidity determination unit detects the rigidity of the recording sheet based on a load current value of the electric motor when the recording sheet is fed from the tray by the feeding roller.

  As a result, the rigidity determining means is realized without physically adding a new configuration.

(4) In addition, the rigidity determination unit may determine the rigidity of the recording sheet based on information regarding the paper type of the recording sheet input from the external device to the image recording apparatus.

  For example, when information regarding the paper type of the recording paper is input to the image recording apparatus together with the image data to be image-recorded, the rigidity of the recording paper can be estimated based on the information. Specifically, when information indicating that the recording paper is glossy paper or a postcard is input, it can be estimated that these papers are relatively thick and have high rigidity. When information indicating that the recording paper is plain paper is input, it can be estimated that the plain paper is relatively thin and therefore has low rigidity.

(5) The image recording apparatus of the present invention further includes a leading edge detecting means for detecting the position of the leading edge of the recording sheet in the traveling direction in each of the plurality of curved paths. In this configuration, it is preferable that the stop means temporarily stops the recording paper in the curved path based on the position of the front end in the traveling direction detected by the front end detection means.

  Thereby, the recording paper can be stopped at an accurate position in the curved path.

(6) Further, the image recording apparatus of the present invention is arranged on the downstream side of the recording head, and is configured to be able to rotate forward and reverse. The recording sheet that has passed the recording head is sandwiched and the sandwiched recording is performed. It further includes a pair of feed rollers that convey the paper toward the outside or to the feed roller so that the first surface of the recording paper comes into contact with the feed roller again. In this configuration, the return passage is branched from a passage connecting the pair of feed rollers and the recording head, and extends toward the feed roller. In this case, after the image is recorded on the first surface of the recording sheet, the stop means is transported through the return path by the pair of feeding rollers and before contacting the feeding roller again. The recording paper is preferably temporarily stopped for a second predetermined time.

  According to the present invention, regardless of the rigidity of the recording paper to be fed, when the recording paper is fed again to the recording head after the image is recorded on the first surface, one of the plurality of curved paths is selected. In this case, curling directed to the opposite side of the recording head can be applied to the leading edge of the recording paper without excess or deficiency. As a result, at the time of image recording on the second surface, curling of the leading edge of the recording sheet to the recording head side is suppressed, and contact between the recording head and the leading edge is prevented.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. The embodiment described below is merely an example of the present invention, and it is needless to say that the embodiment of the present invention can be changed as appropriate without departing from the gist of the present invention.

  FIG. 1 is an external perspective view of a multifunction machine 10 according to an embodiment of the present invention. The multifunction machine 10 is equipped with an ink jet printer unit 11 capable of recording an image on both the front surface (first surface) and the back surface (second surface) of the recording paper, so that the ink adheres without increasing the size of the apparatus. Thus, the recording paper with the curled edge can be corrected with a simple configuration.

  The multifunction machine 10 has various functions such as a facsimile function, a printer function, a scanner function, and a copy function. The printer function has a double-sided image recording function for recording images on both sides of the recording paper. Functions other than the printer function are arbitrary. For example, the image recording apparatus of the present invention may be implemented as a printer having only a printer function that does not have a scan function, a copy function, or a facsimile function.

  The multifunction machine 10 is mainly provided with a printer unit 11 provided at the lower part, a scanner part 12 provided at the upper part, and an operation panel 40 provided at the upper part of the front face.

  The printer unit 11 has an opening 13 formed in the front, and a paper feed tray 20 (an example of a tray according to the present invention) and a paper discharge tray 21 are provided in two upper and lower stages inside the opening 13. The paper feed tray 20 is for loading recording paper. The recording sheets stacked on the sheet feeding tray 20 are fed (feeded) into the printer unit 11 and are discharged to the sheet discharge tray 21 after a desired image is recorded. The paper feed tray 20 and the paper discharge tray 21 are configured to be inserted into and removed from the printer unit 11 through the opening 13.

  The scanner unit 12 is configured as a so-called flat bed scanner. A document cover 30 is provided on the upper portion of the scanner unit 12. The document cover 30 is provided as a top plate of the multifunction machine 10, and a platen glass (not shown) is disposed under the document cover 30. The document is placed on the platen glass and read by the scanner unit 12 while being covered with the document cover 30.

  The operation panel 40 is for operating the printer unit 11 and the scanner unit 12 and is provided with various operation buttons and a liquid crystal display unit. The user can set various functions and perform operations by operating the operation panel 40. For example, setting of the type of recording paper (plain paper or postcard) as a recording paper, setting of a single-sided recording mode for recording an image only on the surface of the recording paper, setting of a double-sided recording mode for recording an image on both front and back sides, Setting of the resolution (draft mode or photo mode) can be instructed via the operation panel 40.

  Next, the configuration of the printer unit 11 will be described with reference to FIGS. 2 and 3. 2 and 3 are longitudinal sectional views schematically showing the structure of the printer unit 11.

  The printer unit 11 is mainly fed by a paper feed tray 20 on which recording paper is stacked, a paper feeding unit 15 that feeds (feeds) recording paper from the paper feed tray 20, and a paper feeding unit 15. It is disposed between a recording unit 24 that records an image on a recording sheet by ejecting ink droplets onto the recording sheet, a discharge tray 21 that discharges the recording sheet, and between the discharge tray 21 and the recording unit 24. In order to record an image on the back surface, a path switching unit 41 that switches the conveyance path of the recording paper is provided.

  Further, in the printer unit 11, there are three curved paths 65 A, 65 B, 65 C formed between the leading end of the paper feed tray 20 and the recording unit 24, and between the recording unit 24 and the paper discharge tray 21. The formed discharge passage 66 and the reversing guide passage 67 formed between the path switching portion 41 and the upstream side of each of the curved passages 65A, 65B, 65C (return of the present invention). An example of a use passage) is formed. The recording sheet fed from the feeding unit 15 is conveyed to the recording unit 24 through one of the three curved paths 65A, 65B, and 65C. The recording sheet that has passed through the recording unit 24 is conveyed to the sheet discharge tray 21 through the sheet discharge path 66, or the conveyance path is switched by the path switching unit 41 and is fed through the reverse guide path 67. It is conveyed to the portion 15 and the curved passages 65A, 65B, 65C.

  A guide flap 70 is provided at a connecting portion 37 (an example of the connecting portion of the present invention) where the three curved passages 65A, 65B, 65C and the reverse guide passage 67 are connected. The guide flap 70 is rotatably supported by the frame of the printer unit 11 and is rotated by receiving a driving force from a flap motor 73 (see FIG. 4). The guide flap 70 guides the recording sheet fed from the feeding unit 15 to any one of the three curved paths 65A, 65B, 65C, and its rotational position is controlled by the control unit 84 described later. Is done. The configuration of the guide flap 70 and the position control by the control unit 84 will be described later.

  The sheet feeding tray 20 is provided below the feeding unit 15. The paper feed tray 20 is disposed on the bottom side of the printer unit 11 and is configured in a rectangular box shape with an open top surface. The paper feed tray 20 has a bottom plate 113 that constitutes a paper placement surface. A plurality of recording sheets are stacked on the bottom plate 113. The recording paper loaded on the paper feed tray 20 is fed to one of the curved paths 65A, 65B, 65C by a paper feed roller 25 (an example of the feed roller of the present invention) provided in the paper feed unit 15.

  The paper discharge tray 21 is disposed above the paper feed tray 20. A flap 17 is attached to the front end (left end in FIG. 2) of the paper discharge tray 21. The flap 17 forms a reverse guide passage 67 together with a guide member 34 and a guide member 35 described later. The flap 17 will be described later.

  When the printer unit 11 records an image only on one side (front surface) of the recording paper, the recording paper fed by the paper feed roller 25 is guided to one of the curved paths 65A, 65B, 65C by the guide flap 70. And conveyed to the recording unit 24. At this time, the recording sheet is conveyed so as to make a U-turn from below to above along any one of the curved paths 65A, 65B, and 65C. Then, after an image is recorded on the surface by the recording unit 24, the recording paper that has passed through the recording unit 24 is discharged to the discharge tray 21 through the discharge path 66.

  On the other hand, when images are recorded on both sides (front and back) of the recording paper, the recording paper on which the image is recorded on the front surface is reversely guided by the path switching unit 41 so that the front surface is in contact with the paper feed roller 25. The paper is guided to the passage 67 and fed again to one of the curved passages 65A, 65B, and 65C by the paper feed roller 25. Then, after an image is recorded on the back surface of the recording paper by the recording unit 24, the image is discharged to the paper discharge tray 21.

  The recording unit 24 is disposed on the upper side of the paper feed tray 20. The recording unit 24 includes a carriage 38 and a recording head 39 (an example of the recording head of the present invention). The recording head 39 is mounted on the carriage 38 and is configured to reciprocate along a guide rail (not shown) extending in the direction perpendicular to the paper surface (main scanning direction) in FIG. In the reciprocation process of the carriage 38, ink supplied from an ink cartridge (not shown) is ejected as fine ink droplets onto a recording sheet conveyed on the platen 42 (see FIG. 2). Thereby, an image is recorded on the recording paper.

  The feeding unit 15 includes a paper feed roller 25, a paper feed arm 26, and a drive transmission mechanism 27. The paper feed roller 25 is disposed on the upper side of the paper feed tray 20. The paper feed roller 25 feeds the recording paper loaded on the paper feed tray 20 to one of the curved paths 65A, 65B, 65C, and is rotatably supported at the tip of the paper feed arm 26. . The sheet feed roller 25 is rotationally driven via a drive transmission mechanism 27 using an SF motor (Sheet Feed Motor) 73 (see FIG. 4) as an example of the electric motor of the present invention as a drive source. The drive transmission mechanism 27 is composed of a plurality of gears arranged substantially linearly, and is configured by meshing them.

  The paper feed roller 25 is provided with a rotary encoder 86 (see FIG. 4). The rotary encoder 86 detects the pattern of an encoder disk (not shown) that rotates together with the paper feed roller 25 with an optical sensor. Based on the signal detected by the optical sensor, the rotation of the paper feed roller 25 is controlled by the control unit 84 described later.

  A base shaft 28 is provided above the paper feed tray 20 and below the recording unit 24. The paper feed arm 26 has a base end portion supported by a base shaft 28 and is configured to be rotatable about the base shaft 28 as a rotation center axis. For this reason, the paper feed arm 26 can move up and down so as to be able to contact and separate from the paper feed tray 20. Further, the paper feed arm 26 is urged to rotate downward by its own weight or urged by a spring or the like. For this reason, the paper feed arm 26 is normally in contact with the paper feed tray 20. The paper feed arm 26 is configured to retract upward when the paper feed tray 20 is inserted into and removed from the printer unit 11.

  When feeding recording paper from the paper feed tray 20, the paper feed arm 26 is biased downward and the paper feed roller 25 is pressed against the recording paper on the paper feed tray 20. The paper roller 25 is rotated. As a result, a frictional force is generated between the roller surface of the paper supply roller 25 and the recording paper, and the recording paper at the uppermost position is sent out to any one of the curved paths 65A, 65B, and 65C by this frictional force. .

  When the leading edge of the recording paper comes into contact with the separation inclined plate 22 provided in the paper feed tray 20, the traveling direction of the recording paper is changed by the separation inclined plate 22. Specifically, the advancing direction of the recording paper sent out from the paper feed tray 20 in the horizontal direction is changed to the inclination direction of the separation inclined plate 22, that is, obliquely upward. When the uppermost recording paper is sent out by the paper feed roller 25, the recording paper immediately below it may be sent out together by friction or static electricity, but this recording paper is restrained by contact with the separation inclined plate 22. Is done.

  The curved passages 65A, 65B, and 65C are curved passages formed between the upper end of the separation inclined plate 22 and the recording unit 24. In the present embodiment, the recording sheet on which the image is recorded on the front surface is temporarily stopped at a second stop position described later set in each of the curved paths 65A, 65B, and 65C, and the curling of the recording sheet due to the adhesion of ink is corrected. Is done. The curved passage 65A is disposed on the innermost side (the paper feed roller 25 side). Further, the curved passage 65C is disposed on the outermost side. The curved passage 65B is disposed between the curved passage 65A and the curved passage 65C. These curved passages 65A, 65B, and 65C are partitioned by a guide plate 68 that separates the passages. Each of the curved passages 65A, 65B, 65C has a different curvature. In the present embodiment, the curvature of the curved passage 65A disposed on the inner side is the smallest, and the curvature of the curved passage 65C disposed on the outer side is the largest. In other words, if the curvature of the curved passage 65B disposed in the middle is K (second threshold value of the present invention), the curvature of the curved passage 65A is smaller than the curvature K, and the curvature of the curved passage 65C is the curvature. Greater than rate K. Therefore, the curved passage 65A is curved most gently, and the curved passage 65C is curved most tightly. Each of the curved passages 65A, 65B, and 65C is bent upward in the U shape from the upper end of the separation inclined plate 22 to the front side (right side in FIG. 2) and reaches the recording unit 24. Therefore, the recording sheet fed from the sheet feeding tray 20 by the sheet feeding roller 25 is conveyed so that the surface opposite to the surface on which the sheet feeding roller 25 is in contact is opposed to the recording head 39 of the recording unit 24. Is done. The paper discharge passage 66 extends substantially linearly from the recording unit 24 to the front side from the back side (left side in FIG. 3) of the multifunction machine 10 and communicates with the paper discharge tray 21.

  The guide flap 70 is provided at the connection portion 37. The guide flap 70 is composed of two plate members arranged opposite to each other at a predetermined interval, and a rotation shaft 69 provided on one plate material, and the rotation shaft 69 is a frame of the printer unit 11 or the like. It is supported by. The rotation shaft 69 is connected to a flap motor 74 (see FIG. 4) via a known drive transmission mechanism such as a gear or a belt. The guide flap 70 is disposed at one of the first position P1, the second position P2, and the third position P3 when the flap motor 74 is driven and controlled by the control unit 84. Here, the first position P1 is a position for guiding the recording sheet fed from the sheet feeding tray 20 to the curved path 65A. The second position P2 is a position for guiding the recording sheet to the curved path 65B. The third position P3 is a position for guiding the recording sheet to the curved path 65C. The guide flap 70 is not limited to the driving method by the flap motor 74, and is rotated by the driving force transmitted from the SF motor 73 or the LF motor 71 via the drive transmission mechanism, for example. Also good.

  In the present embodiment, when single-sided recording in which image recording is performed only on the surface of the recording paper is performed, the control unit 84 arranges the guide flap 70 at the second position P2. In the double-sided recording in which the image is recorded on both sides of the recording paper, when the recording paper is conveyed from the reverse guide path 67 to the curved paths 65A, 65B, and 65C in order to record an image on the back side, the control unit 84 The guide flap 70 is arranged at any position corresponding to the rigidity of the recording paper on which the image is recorded. For example, when it is determined that the rigidity of the recording paper being conveyed is larger than the rigidity of the plain paper, the guide flap 70 is disposed at the first position P1 in order to guide the recording paper to the curved path 65A. On the other hand, when it is determined that the rigidity of the recording paper being conveyed is smaller than the rigidity of the plain paper, the guide flap 70 is disposed at the third position P3 in order to guide the recording paper to the curved path 65C. When it is determined that the rigidity of the recording sheet being conveyed is equal to the rigidity of the plain paper, the guide flap 70 is disposed at the second position P2 in order to guide the recording sheet to the curved path 65B.

  The paper discharge path 66 extends substantially linearly from the recording unit 24 to the front side (right side in FIG. 2) of the multifunction machine 10, and the end of the paper discharge path 66 leads to the paper discharge tray 21.

  A conveying roller 60 and a pinch roller 61 are provided between the terminal ends of the curved paths 65A, 65B, and 65C and the recording unit 24. These are paired. The pinch roller 61 is disposed so as to be in pressure contact with the lower side of the conveying roller 60. The conveyance roller 60 and the pinch roller 61 nipping the recording paper conveyed through any one of the curved paths 65A, 65B, and 65C and feeding it onto the platen 42.

  A paper discharge roller 62 and a spur 63 are provided between the recording unit 24 and the start end of the paper discharge path 66. The paper discharge roller 62 and the spur 63 sandwich the recorded recording paper and convey it further downstream (on the paper discharge tray 21 side). The conveyance roller 60 and the paper discharge roller 62 are rotated by a rotational driving force transmitted from the LF motor 71 (see FIG. 4).

  The transport roller 60 and the paper discharge roller 62 are driven using the LF motor 71 as a drive source. The driving of the transport roller 60 and the paper discharge roller 62 is synchronized and is intermittently driven during image recording. As a result, the recording sheet is image-recorded while being sent with a predetermined line feed width.

  The transport roller 60 is provided with a rotary encoder 87 (see FIG. 4). The rotary encoder 87 detects a pattern of an encoder disk (not shown) that rotates together with the conveyance roller 60 with an optical sensor, and controls the rotation of the conveyance roller 60 and the discharge roller 62 based on a signal detected by the optical sensor. Is done. In addition, before and after image recording, the transport roller 60 and the paper discharge roller 62 are continuously driven to realize rapid paper transport.

  A rotor 103 is provided on the upstream side of the transport roller 60. The rotor 103 protrudes from the outermost guide plate 68 toward the curved passages 65A, 65B, 65C, and is disposed so as to cross the curved passages 65A, 65B, 65C. When the recording medium passing through the curved path pushes away the rotor 103 and proceeds downstream, the rotor 103 rotates. At this time, a detector (not shown) included in the rotor 103 blocks an optical path of the photo interrupter 105 described later. As a result, the output signal from the photo interrupter 105 varies. Based on this variation, the control unit 84 detects the position of the leading edge in the traveling direction of the recording paper passing through each of the curved paths 65A, 65B, 65C (hereinafter referred to as “tip position”). In the present embodiment, the rotor 103, the photo interrupter 105, and the control unit 84 realize the tip detection means of the present invention.

  The reverse guide passage 67 branches from the paper discharge passage 66 and extends to the upstream side of the curved passages 65A, 65B, 65C, specifically, to the vicinity of the guide flap 70. Specifically, the reverse guide passage 67 is formed from the branch portion 36 of the paper discharge passage 66 to the connection portion 37 near the guide flap 70 through the paper feed tray 20. The reversal guide path 67 constitutes a reversal path that guides the recording sheet having an image recorded on the surface thereof back onto the paper feed tray 20.

  The reverse guide passage 67 is formed by a guide member 35 provided in a frame or the like of the printer unit 11 and a flap 17 pivotally supported on the paper discharge tray 21. The guide member 35 extends obliquely downward from the branch portion 36 of the paper discharge passage 66 toward the paper feed roller 25.

  In the present embodiment, the reverse guide path 67 is configured to return the recording paper onto the paper feed tray 20, but is not limited to this. In short, it is sufficient for the reverse guide path 67 to be able to connect the branch part 36 and the connection part 37 of the curved path 23, so that the recording sheet passes from the paper discharge path 66 through a path other than the reverse guide path 67. What is necessary is just to return to the connection part 37. FIG.

  The flap 17 has a support shaft 115. The support shaft 115 is rotatably supported at the tip of the paper discharge tray 21. Therefore, the flap 17 can rotate around the support shaft 115. The flap 17 has a protruding portion 117 that protrudes obliquely downward from the center in the width direction of the paper feed tray 20 (perpendicular to the paper surface in FIG. 2) toward the bottom plate 113 of the paper feed tray 20. The protruding portion 117 extends to the bottom plate 113 in a state where no recording paper is present in the paper feed tray 20.

  The flap 17 is rotated by its own weight or by a torsion coil spring (not shown) provided on the support shaft 115 in the direction indicated by the arrow 119 in FIG. Contacts the uppermost recording sheet. The flap 17 always contacts the top surface of the recording paper even if the recording paper stacking amount on the paper feed tray 20 changes. Therefore, the recording paper loaded on the paper feed tray 20 receives a downward pressing force from the flap 17. Since this pressing force acts on the recording paper, even if the leading edge of the recording paper that has passed through the reverse guide path 67 and returned to the paper feed tray 20 is curled (curled back), the curl is pressed by the flap 17. It is done.

  Next, the route switching unit 41 will be described. The path switching unit 41 is disposed in the paper discharge path 66. Specifically, the path switching unit 41 is disposed in the branch portion 36 in the paper discharge passage 66, that is, in the vicinity of the connection portion between the paper discharge passage 66 and the reverse guide passage 67. The path switching unit 41 is provided with a first roller 45 and a second roller 46 (an example of a pair of feed rollers according to the present invention) constituting a roller pair, and an auxiliary roller 47 arranged in parallel with the second roller 46. ing.

  The first roller 45 and the second roller 46 sandwich the recording paper sent from the paper discharge roller 62 and the spur 63. The first roller 45 and the second roller 46 can transport the recording paper along the paper discharge path 66 further downstream in the transport direction (discharge tray 21 side) and can transport the recording paper to the reverse guide path 67. It is.

  The second roller 46 and the auxiliary roller 47 are attached to the frame 48. The frame 48 extends in the left-right direction of the multi-function device 10 (the direction perpendicular to the paper surface of FIG. 2). A plurality of second rollers 46 and auxiliary rollers 47 are arranged in the frame 48 at predetermined intervals in the width direction of the multifunction machine 10. The second roller 46 and the auxiliary roller 47 are supported by shafts 50 and 51 whose axial direction is a direction perpendicular to the paper surface in FIG. 2, and are rotatable about the shafts 50 and 51. Since the second roller 46 and the auxiliary roller 47 are in contact with the recording surface of the paper, they are formed in a spur shape like the spur 63. The auxiliary roller 47 is disposed upstream of the second roller 46 by a predetermined distance. The second roller 46 is urged toward the first roller 45 by an elastic member.

  The first roller 45 is connected to an LF motor 71 (see FIG. 4) via a predetermined drive transmission mechanism, and is driven to rotate using the LF motor 71 as a drive source. The first roller 45 includes a central shaft 52, and the central shaft 52 is supported by the frame of the printer unit 11.

  A second roller 46 is disposed above the first roller 45. The first roller 45 may be formed in a single elongated cylindrical shape, and a plurality of rollers may be disposed to face the second rollers 46, respectively. The first roller 45 is rotated forward or backward by the LF motor 71. The recording paper conveyed from the recording unit 24 along the paper discharge path 66 is sandwiched between the first roller 45 and the second roller 46.

  As shown in FIG. 2, the path switching unit 41 is configured such that the frame 48, the second roller 46, and the auxiliary roller 47 rotate integrally in the direction of the arrow 29 with the central shaft 52 as the rotation center. ing. The path switching unit 41 changes its posture in the direction of the arrow 29 depending on the presence or absence of the driving force transmitted from the LF motor 71 (see FIG. 4). Specifically, the path switching unit 41 reverses the recording paper that has passed the recording unit 24 and the discharge posture (see FIG. 2) for discharging the recording paper that has passed the recording unit 24 to the paper discharge tray 21 and the reverse guide. It can be changed to a reverse posture (see FIG. 3) for guiding to the passage 67.

  When the first roller 45 is rotated forward (clockwise rotation in FIGS. 2 and 3) by the LF motor 71, the path switching unit 41 maintains its posture in the above-described discharge posture. Thus, the recording paper that has passed through the recording unit 24 is sent to the paper discharge tray 21 side (the right side in FIG. 2). When performing single-sided recording, the first roller 45 continues to rotate forward, so that the recording paper is sandwiched between the first roller 45 and the second roller 46 and conveyed downstream as shown in FIG. Then, the paper is discharged to the paper discharge tray 21.

  When performing double-sided recording, the path switching unit 41 is configured so that the first roller 45 and the second roller 46 sandwich the trailing edge of the recording sheet, and the reverse posture (see FIG. 3) from the discharge posture (see FIG. 2). ) Is changed. This change in posture is caused by switching the rotation direction of the LF motor 71 (see FIG. 4) and switching the first roller 45 from normal rotation to reverse rotation (counterclockwise rotation in FIGS. 2 and 3). Achieved. When the path switching unit 41 is changed to the reverse posture, the rear end portion of the recording sheet is pressed downward by the auxiliary roller 47. As a result, the recording sheet that has passed through the recording unit 24 is conveyed in a switchback manner and fed into the reverse guide path 67 from the rear end side.

  In the present embodiment, when the first roller 45 is rotating forward, the driving force of the SF motor 73 (see FIG. 4) is transmitted to the sheet feeding roller 25 via the base shaft 28, and the first roller 45 rotates in the reverse direction. In some cases, the driving force is not transmitted to the paper feed roller 25. That is, the driving force of the SF motor 73 is not transmitted to the base shaft 28 while the recording sheet is conveyed through the reverse guide path 67 by the first roller 45 or the like. Such a configuration can be realized by independently controlling the SF motor 73 that supplies driving force to the paper feed roller 25. Of course, when a drive transmission system in which the rollers such as the paper feed roller 25 and the conveyance roller 62 are driven by a common motor is used, the above operation can be realized by using a transmission switching mechanism such as a clutch or a planetary gear. it can.

  Next, the configuration of the control unit 84 of the multifunction machine 10 will be described with reference to FIG. FIG. 4 is a block diagram illustrating a configuration of the control unit 84 of the multifunction machine 10. The control unit 84 controls the overall operation of the multifunction machine 10, but a detailed description of the control of the scanner unit 12 and the recording unit 24 is omitted. In the present embodiment, the control unit 84 embodies rigidity determination means, passage determination means, flap control means, and stop means of the present invention.

  The control unit 84 is configured as a microcomputer mainly including a CPU 88, ROM 89, RAM 90, and EEPROM 91, and is connected to each unit via a bus 92.

  The ROM 89 stores a program for controlling various operations of the multifunction machine 10. For example, a control program for executing the processing of each procedure (step) according to the flowchart shown in FIG. 5 is stored.

  The RAM 90 is used as a storage area or work area for temporarily recording various data used when the CPU 88 executes the program. The EEPROM 91 stores data, settings, flags, etc. that should be retained even after the power is turned off.

  The drive circuit 94 includes an LF motor 71 connected to the transport roller 60, the paper discharge roller 62, the first roller 45, the SF motor 73 connected to the paper feed roller 25, and a flap connected to the guide flap 70. The motor 74 is driven. The drive circuit 94 is provided with drivers for driving the LF motor 71, the SF motor 73, and the flap motor 74. The LF motor 71, the SF motor 73, and the flap motor 74 are It is controlled independently by each driver. The drive circuit 94 receives the phase excitation signal output from the CPU 88 and generates an electrical signal for rotating the LF motor 71, the SF motor 73, and the flap motor 74. In response to the electrical signal, the LF motor 71, the SF motor 73, and the flap motor 74 rotate, and the rotational force of the conveyance roller 60, the discharge motor 60, and the like via a known drive transmission mechanism including a gear, a drive shaft, and the like. This is transmitted to the paper roller 62, the first roller 45, the paper feed roller 25, and the guide flap 70.

  The control unit 84 monitors the drive current output from the drive circuit 94 to the SF motor 73 via the driver via the bus 92. Specifically, an analog distributor having one input and two outputs is provided on the primary (input) line of the SF motor 73, and one of the outputs is supplied to the SF motor 73 and the other output is output. Can be fed back to the control unit 84 via the bus 92. Of course, the digitized signal may be fed back using an A / D converter. When the recording paper is fed by the paper feed roller 25, the control unit 84 specifically drives the SF motor 73 drive current value (load current value) based on the feedback signal immediately after the paper feed is started. Measure. Then, the control unit 84 determines the rigidity of the recording paper based on this drive current value.

  For example, when thick paper such as glossy paper or postcard having high rigidity is fed, a larger conveying force is required than when feeding plain paper. In the configuration in which the separation inclined plate 22 is provided in the paper feed tray 20 as in the present embodiment, the thick paper must be bent against the rigidity of the thick paper when the leading edge of the thick paper exceeds the separation inclined plate 22. Compared to the case of feeding plain paper with less rigidity than that, a larger conveying force is required. For this reason, the drive current to the SF motor 73 becomes larger than when plain paper is fed. In this embodiment, the controller 84 finds that there is a relationship between the magnitude of rigidity and the drive current value at the time of paper feeding, and using this relationship, the control unit 84 uses the rigidity of the recording paper to be fed. Determine. Specifically, the control unit 84 uses the driving current value (an example of the first threshold value of the present invention) required for feeding plain paper as a threshold value, and the driving current value measured at the time of feeding the threshold value is the above threshold value. Is greater than the stiffness of plain paper. On the other hand, the control unit 84 determines that the rigidity of the recording paper is relatively small (smaller than the rigidity of plain paper) when the measured drive current value is smaller than the threshold value.

  In the multifunction machine 10 according to the present embodiment, the LF motor 71 is a driving source for conveying the recording paper positioned on the platen 42 and discharging the recorded recording paper to the paper discharge tray 21. Is a drive source for driving the paper discharge roller 62 via a predetermined drive transmission mechanism. The LF motor 71 is also a drive source for switching the path switching unit 41 to either the discharging posture (see FIG. 2) or the reverse posture (see FIG. 3) via a planetary gear or the like.

  The bus 92 detects the amount of rotation of the photo interrupter 105 for detecting the leading end position of the recording paper fed from the paper feed roller 25 to the curved path 23A, the transport roller 60 driven by the LF motor 71, and the like. A rotary encoder 87, a rotary encoder 86 for detecting the rotation amount of the paper feed roller 25 driven by the SF motor 73, and the like are connected. Based on the output signal of the photo interrupter 105 and the encoder amount detected by the rotary encoders 86 and 87, the control unit 84 grasps the position of the leading or trailing edge of the recording paper and the transport amount of the recording paper.

  Next, referring to FIGS. 7 to 9, the procedure of control processing executed by the control unit 84 when performing double-sided image recording in the printer unit 11 of the multifunction machine 10 using the flowcharts of FIGS. 5 and 6. An example will be described. FIG. 5 is a flowchart illustrating a procedure of control processing executed by the control unit 84 of the multifunction machine 10. FIG. 6 is a flowchart illustrating the procedure of the stiffness determination process executed by the control unit 84 of the multifunction machine 10. In the control process of FIG. 5, it is assumed that a double-sided image recording instruction has been input. FIG. 7 is a plan view of the recording sheet 123 facing the front surface. 8 and 9 are cross-sectional views showing the state of the recording paper 123 during double-sided image recording in chronological order.

  When a double-sided image recording execution instruction is input, first, the SF motor 73 is driven to rotate the paper feed roller 25. As a result, the recording paper 123 stored in the paper feed tray 20 is fed.

  Next, the control unit 84 determines the rigidity of the recording paper fed from the paper feed tray 20. Specifically, as shown in FIG. 6, based on the feedback signal from the drive circuit 94, the drive current value output to the SF motor 73 at the start of paper feeding is measured (S31). The control unit 84 determines whether or not the measured value is larger than the threshold value by comparing with a predetermined threshold value (S32). In the present embodiment, as the threshold value, a drive current value (an example of the first threshold value of the present invention) immediately after paper feeding when plain paper is fed from the paper feed tray 20 is employed. As described above, since there is a relationship between the rigidity of the recording paper and the driving current value immediately after the paper feeding, the threshold of the driving current value immediately after the paper feeding determines the rigidity of the recording paper 123 to be fed. Can be obtained. If it is determined in step S32 that the measured value is larger than the threshold (Yes in S32), the recording paper 123 is stiffer than plain paper (in this embodiment, “thick paper”). A flag indicating the presence is set in the RAM 90 (S33). On the other hand, when the measured value is not larger than the threshold value in step S32 (No side of S32), if it is determined in the next step S34 that the measured value is equivalent to the threshold value (Yes side of S33), A flag indicating that the recording paper 123 has the same rigidity as that of plain paper (in this embodiment, “plain paper”) is set in the RAM 90 (S35). In step S33, if it is determined that the measured value is not equivalent to the threshold value (No in S33), that is, the measured value is determined to be smaller than the threshold value, and the recording paper 123 is plain paper. A flag indicating that the rigidity is lower (in this embodiment, “thin paper”) is set in the RAM 90 (S36).

  In the present embodiment, the rigidity of the recording paper 123 is determined based on the drive current value of the SF motor 73. For example, the thickness of the recording paper 123 is detected using an optical sensor or the like. Various methods such as a method for determining the rigidity of the recording paper 123 from the thickness or a method for determining the rigidity of the recording paper 123 by contacting the recording paper being conveyed and detecting the reaction force thereof are employed. It is possible.

  When the rigidity determination is finished, as shown in FIG. 5, one curved path through which the recording paper 123 having the image recorded thereon is conveyed is determined from the curved paths 65A, 65B, 65C (S3). ). Specifically, a curved path 65A is associated with a path corresponding to thick paper, and further, a lookup table in which the curved path 65B is associated with plain paper and the curved path 65C is associated with thin paper is referred to. Then, the control unit 84 determines one curved path. The association described above is based on the fact that the curl at the leading edge of the recording paper is smaller when an image is recorded on thick paper having high rigidity than when an image is recorded on thin paper. In other words, the larger the rigidity, the smaller the curl. Therefore, when the recording paper 123 is thick paper, the curved path 65A having a gentle curve (small curvature) is determined. Similarly, since the thin paper with low rigidity has a large curl, when the recording paper 123 is a thin paper, the curved passage 65C having a tight curve (high curvature) is determined. Information about the determined curved path is stored in the RAM 90.

  When the paper feeding roller 25 is rotated, the recording paper 123 is sent out from the paper feeding tray 20, and the recording paper 123 is conveyed to the curved path 65B by the guide flap 70 initially arranged at the second position P2. By passing through the curved path 65 </ b> B, the recording sheet 123 is reversed so that the surface (front surface) opposite to the surface with which the sheet feeding roller 25 contacts is opposed to the nozzle forming surface of the recording head 39. The conveyance path conveyed immediately after the start of paper feeding is not limited to the curved path 65B, and may be, for example, the curved path 65A that is the least curved or the curved path 65C that is tightly curved.

  When the recording paper 123 reaches the conveyance roller 60 and the pinch roller 61, the recording paper 123 is sandwiched by the conveyance roller 60 and the pinch roller 61, and the recording paper 123 is moved between the recording head 39 and the platen by the conveyance roller 60 and the pinch roller 61. 42. Then, image recording on the surface facing the recording head 39 is started. Further, simultaneously with the start of image recording on the surface, detection of the amount of ink discharged toward the surface is started by the CPU 88 of the control unit 84 (S4).

  Here, with reference to FIG. 7, detection of the amount of ink discharged to the surface will be described. FIG. 7 is a plan view of the recording sheet 123 facing the front surface. In FIG. 7, the conveyance direction in which the recording paper is conveyed between the recording head 39 and the platen 42 is indicated by a white arrow 76. Further, the end of the lower recording sheet 123 in the figure, which is the leading end when image recording is performed on the front surface and the rear end when image recording is performed on the back surface, is referred to as an end portion 123A using reference numeral 123A. Also, the end of the upper recording sheet 123 in the figure, which is the rear end when image recording is performed on the front surface and the front end when image recording is performed on the rear surface, is referred to as an end portion 123B using reference numeral 123B. Further, in the recording sheet 123, an area from the end 123B to the distance L1 in the transport direction 76 is defined as a first area R1, and the remaining area (an area from the end 123A to the distance L2 in the counter-transport direction 76) is the second. Region R2.

  The distance L1 from the end portion 123B to the conveyance direction 76 is a contact area 78 of the paper feed roller 25 that contacts the surface of the recording paper 123 from the end portion 123B (second line in FIG. This is the approximate distance to the dotted line).

  Then, the ink discharge amount discharged to the first region R1 and the ink discharge amount discharged to the second region R2 are detected as the ink discharge amount discharged onto the surface. In the present embodiment, the amount of ink ejected to the first region R1 and the amount of ink ejected to the second region R2 are detected by the number of ejections of ink ejected to each region. The number of ink ejections is counted by the CPU 88 and the count value is stored in the RAM 90 as needed. However, the method for detecting the ink discharge amount is not limited to this. For example, the ink discharge amount is calculated from the ink consumption amount, or based on the gradation or color distribution of the recorded image data. Thus, the ink discharge amount may be predicted. Alternatively, the density of the recorded image actually recorded may be read by a density sensor or the like, and the ink discharge amount may be calculated based on the density value.

  When image recording on the surface and detection of the ink discharge amount are started, the recording paper 123 is intermittently conveyed by the conveying roller 60 and the pinch roller 61, and the carriage 38 is slid while the recording paper 123 is stopped. An image is recorded on the surface of the recording paper 123 by the recording head 39.

  When the recording paper 123 reaches the paper discharge roller 62 and the spur 63, the paper discharge roller 62 and the spur 63 are driven, and the recording paper 123 is further conveyed downstream by the paper discharge roller 62 and the spur 63. Further, when the recording paper 123 reaches the first roller 45 and the second roller 46, the first roller 45 and the second roller 46 are driven, and the recording paper 123 is further moved downstream by the first roller 45 and the second roller 46. Transport. During this time, the image recording on the surface of the recording paper 123 and the detection of the ink discharge amount are completed (S5).

  Then, when the image recording on the surface is finished, the first drying time T1 necessary for drying the first region R1 according to the ink discharge amount discharged to the first region R1 and the second region R2, and The CPU 88 calculates the second drying time T2 necessary for drying the second region R2 (S6). Such processing refers to, for example, referring to the look-up table in Table 1 in which the number of ink ejections and the drying time corresponding to the number of ejections are associated, and the drying time corresponding to the number of ejections detected in step S5. This is done by selecting from a lookup table.

  Here, the lookup table of Table 1 will be described. The drying time T required for drying the recording paper is considered to be proportional to the number of ink ejections. Therefore, in this look-up table, there is a relationship of Ta <Tb <Tc between Ta, Tb, and Tc that are predetermined as the drying times T1 and T2.

  Subsequently, as shown in FIG. 8A, the recording sheet 123 is moved by the first roller 45 and the second roller 46 to the first stop position where the recording sheet 123 is sandwiched between the first roller 45 and the second roller 46. The recording paper 123 is conveyed, and the driving of the first roller 45 and the second roller 46 is stopped at the first stop position (S7). Here, the first stop position is a position where the end 123B is sandwiched between the rollers of the path switching unit 41 as shown in FIG. Thereafter, the first drying time T1 is stopped while maintaining the discharging posture shown in FIG. 8A (S8).

  Accordingly, a drying time for drying the first region R1 of the recording paper 123 can be secured before the first region R1 of the recording paper 123 contacts the paper feed roller 25, and the first region R1 of the recording paper 123 can be secured. Is in contact with the paper feed roller 25, it is possible to prevent the image recorded in the first region R 1 of the recording paper 123 from being transferred to the paper feed roller 25 and becoming dirty.

  Thereafter, when the first drying time T1 elapses, the path switching unit 41 is driven so as to change the path switching unit 41 in the discharging posture to the reverse posture as shown in FIG. 8B (S9).

  When changing the path switching unit 41 to the reverse posture, the path switching unit 41 is rotated about the central axis 52 of the first roller 45, and the recording sheet 123 is pressed by the auxiliary roller 47. As a result, the recording sheet 123 is pressed by the auxiliary roller 47 from the front side toward the reverse guide passage 67, and the recording sheet 123 is positioned at the upstream side of the recording sheet 123 as shown in FIG. 123B enters the reverse guide passage 67 side.

  Then, the first roller 45 and the second roller 46 are driven in reverse to convey the recording paper 123 toward the paper feed roller 25 in the reverse guide path 67 (S10). Thereafter, as shown in FIG. 8C, when the end 123B of the recording paper 123 reaches the paper feed roller 25, the control unit 84 drives the flap motor 74 to rotate the guide flap 70, It arrange | positions at a predetermined position (S11). Specifically, it arrange | positions in the position corresponding to the curved path determined by step S3 among 1st position P1, 2nd position P2, and 3rd position P3. Thereafter, the paper feed roller 25 is driven (S12).

  However, the paper feed roller 25 is driven after a lapse of a predetermined time after the recording paper 123 reaches the paper feed roller 25, and during this time, the first roller 45 and the second roller 46 are continuously reversed. As a result, the skew of the recording sheet 123 is adjusted, and the refeeding property by the sheet feeding roller 25 can be improved.

  The paper feed roller 25 is driven, and recording is performed by the paper feed roller 25, the first roller 45, and the second roller 46 to a predetermined second stop position in the curved path as shown in FIG. 8C. The recording paper 123 is conveyed until the end 123B of the paper 123 reaches, and when the end 123B reaches the second stop position, the paper feed roller 25, the first roller 45, and the second roller 46 are driven. Stop (S13). Specifically, the recording sheet is conveyed by a predetermined conveyance distance after the end 123B of the recording sheet 123 is detected based on the output signal of the photo interrupter 105, and then stopped. The second stop position is set to a position where the curve is the tightest in each curved path.

  Then, the recording paper 123 is temporarily stopped at the second stop position for the second drying time T2 calculated in step S6 (S14). The second drying time T <b> 2 is a time required for attaching a downward curl on the platen 42 to the end 123 </ b> B of the recording paper 123. When the second drying time T2 is stopped in a state where the recording paper 123 is deformed in the curved path 65, the end 123B of the recording paper 123 is curled toward the platen 42 side.

  As a result, the leading end of the recording sheet 123 conveyed to the platen 42 is directed toward the platen 42, so that the leading end of the recording sheet 123 that has been curled toward the recording head 39 is corrected to a downward curl, and the leading end is the recording head. Contact with 39 is prevented. Further, the recording paper 123 is smoothly guided toward the space between the recording head 39 and the platen 42. Further, the curling is performed by stopping the second drying time in the curved path 65 in a state where the recording paper 23 is deformed in a curved shape, so that a new physical configuration is provided for curling. The recording paper 123 can be curled with a simple configuration without the need for mounting, increasing the size of the apparatus, and the like. Further, while the recording paper 123 is stopped for the second drying time T2, the second region R2 of the recording paper 123 that has not passed through the paper supply roller 25 can be dried, and the stop time for curling can be reduced. By combining the stop time for drying, double-sided image recording can be performed at high speed.

  In addition, one curved path is determined from the curved paths 65A, 65B, and 65C according to the rigidity of the recording sheet 123 as a conveyance path through which the recording sheet 123 having an image recorded on the surface passes. In the curved path, the end 123B of the recording sheet 123 can be appropriately curled without excess or deficiency.

  When the second drying time T2 has elapsed at the second stop position, the recording paper 123 thereafter passes through the curved path 65, so that the recording paper 123 has a surface (back surface) opposite to the surface (front surface) with which the paper feed roller 25 abuts. ) Is reversed so as to face the nozzle formation of the recording head 39, and image recording is started by the recording head 39 on the back surface (S15).

  Then, before the leading edge (the leading edge of the back surface) of the recording sheet 123 enters the path switching unit 41, the path switching unit 41 is driven so that the path switching unit 41 is changed from the reverse posture to the discharge posture again (S16). ). Thereafter, when the image recording on the back surface of the recording paper 123 is completed (S17), the recording paper 123 on which images are recorded on both sides is conveyed downstream in the conveying direction by the first roller 45 and the second roller 46. At this time, the first roller 45 and the second roller 46 are rotated forward, and the recording paper 123 is discharged to the paper discharge tray 21 (S18).

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention.

  In the above-described embodiment, the rigidity of the recording paper is determined based on the drive current value of the SF motor 73 immediately after feeding from the paper feed tray 20, but for example, the printer unit 11 is an external device such as a personal computer. When connected to a device via a network so as to be communicable, the stiffness of the recording paper is determined based on information regarding the paper type of the recording paper input from the external device to the printer unit 11 via the network. Is also possible. In the external device, the above information is input by the user using a printer driver corresponding to the printer unit 11, and the upper part is sent to the printer unit 11 together with a print instruction and print data for the printer unit 11. It is configured.

  In the above-described embodiment, the three curved passages 65A, 65B, and 65C are provided. However, two or four or more curved passages are provided, and the guide flap 70 is used to respond to the rigidity of the recording paper. The recording sheet may be guided in the curved path.

FIG. 1 is an external perspective view of a multifunction machine 10 according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing the structure of the printer unit 11. FIG. 3 is a longitudinal sectional view showing the structure of the printer unit 11. FIG. 4 is a block diagram illustrating a configuration of the control unit 84 of the multifunction machine 10. FIG. 5 is a flowchart illustrating a procedure of control processing executed by the control unit 84 of the multifunction machine 10. FIG. 6 is a flowchart illustrating the procedure of the stiffness determination process executed by the control unit 84 of the multifunction machine 10. FIG. 7 is a plan view of the recording sheet 123 facing the front surface. FIG. 8 is a cross-sectional view showing the state of the recording paper 123 during double-sided image recording in chronological order. FIG. 9 is a cross-sectional view showing the state of the recording paper 123 during double-sided image recording in chronological order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Multifunction machine 11 ... Printer part 20 ... Paper feed tray 21 ... Paper discharge tray 65A, 65B, 65C ... Curve path 67 ... Reverse guide path 25 ... Paper feed roller 39: Recording head 84: Control unit

Claims (6)

A recording roller that feeds the recording paper by rotating while contacting the recording paper contained in the tray, and a recording that records an image by ejecting ink onto the recording paper fed by the feeding roller. An image recording apparatus capable of recording images on both the first surface and the second surface of the recording paper by the recording head,
A plurality of curved passages that are formed so that a recording sheet can be guided toward the recording head so that a surface opposite to the surface in contact with the feeding roller faces the recording head;
A return path for returning the recording paper on which the image is recorded on the first surface by the recording head to the upstream side of the plurality of curved paths;
A guide flap that is rotatably provided at a connecting portion between the plurality of curved passages and the return passage, and guides a recording sheet passing through the return passage to any one of the plurality of curved passages;
Rigidity determination means for determining the rigidity of the recording sheet before the recording sheet fed into the return path after recording an image on the first surface enters one of the plurality of curved paths;
Passage determining means for determining, from the plurality of curved paths, one curved path having a curvature corresponding to the rigidity determined by the rigidity determining means;
Flap control means for operating the guide flap so that the recording paper is conveyed to the curved path determined by the path determination means;
Stop means for temporarily stopping the recording paper for a first predetermined time in the curved path determined by the path determining means before the recording paper on which an image is recorded on the second surface reaches the recording head;
An image recording apparatus comprising: The passage determining means is
When the rigidity of the recording paper on which the image is recorded on the second surface is larger than the first threshold determined with respect to the rigidity of the recording paper, the curved path having a curvature smaller than the second threshold determined with respect to the curvature is provided. Decide
The curved path having a curvature larger than the second reference value is determined when the rigidity of the recording sheet on which the image is recorded on the second surface is smaller than the first threshold. Image recording device. An electric motor for applying a rotational force to the feeding roller;
3. The image recording according to claim 1, wherein the rigidity determination unit detects the rigidity of the recording sheet based on a load current value of the electric motor when the recording sheet is fed from the tray by the feeding roller. apparatus.   The image recording apparatus according to claim 1, wherein the rigidity determining unit determines the rigidity of the recording sheet based on information regarding a paper type of the recording sheet input from an external device to the image recording apparatus. A tip detecting means for detecting the position of the tip of the recording paper in the traveling direction in each of the plurality of curved paths;
5. The image recording apparatus according to claim 1, wherein the stopping unit is configured to temporarily stop the recording sheet in the curved path based on the position of the leading end in the traveling direction detected by the leading end detecting unit. . The recording sheet is disposed downstream of the recording head and configured to be forwardly and reversely rotated. The recording sheet that has passed through the recording head is sandwiched, and the sandwiched recording sheet is directed to the outside or the recording sheet A pair of feed rollers that convey toward the feed roller so that one surface again comes into contact with the feed roller;
The return path is branched from a path connecting the pair of feed rollers and the recording head, and extends toward the feed roller.
After the recording of the image on the first surface of the recording paper, the stopping means is arranged so that the recording paper is transported through the return path by the pair of feeding rollers and is again brought into contact with the feeding roller. 6. The image recording apparatus according to claim 1, wherein the sheet is temporarily stopped for a second predetermined time.

Images