JP2011073820A - Recording device equipped with double feed determining function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording device wherein, when an image is recorded over one face of a plurality of double-fed recording media and the image is not normally recorded on one recording medium, the same image as the image which is recorded over the other face of one of the recording media is recorded to allow the reuse of the recording medium on one face of which the image is not normally recorded, if desired by a user. <P>SOLUTION: When a user sets a single-side recording mode into a re-recording mode for re-recording a first image on the other face of one of the double-fed sheets of recording paper over which the first image is recorded, a printer part 14 utilizes a value for the shift length between the double-fed sheets of recording paper and a change-over of a switch-back roller 76 from positive rotation into reverse rotation for carrying one sheet of recording paper to a re-carrying part 28 to record the first image on the other face of one sheet of paper and for discharging the other sheets of recording paper to a discharge part 23. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording apparatus having a multi-feed judgment function for recording media, and more particularly, even when images are recorded across one side of a plurality of recording media by being double-fed, the recording is performed across the images. The present invention relates to a recording apparatus capable of recording the same image as the image recorded across the other surface of one of the plurality of recording media.

  The facsimile apparatus described in Patent Document 1 includes a paper feed cassette on which recording media are stacked, a paper feed roller that feeds the loaded recording media, and a transfer unit that records an image on the fed recording medium. A recording unit, a size detection plate and a pre-registration sensor for detecting whether or not the recording medium is double fed are provided. The size detection plate detects the size of the paper feed cassette, and the size of the paper feed cassette is determined according to the size of the recording medium to be loaded. That is, the size detection plate can detect the recording medium length that is the value of the length in the conveyance direction of one recording medium. Further, the pre-registration sensor is disposed upstream of the recording unit in the recording medium conveyance direction. The control unit of this facsimile apparatus detects the leading and trailing edge length, which is the length value from the leading edge to the trailing edge of one or a plurality of recording media conveyed by the pre-registration sensor signal. Therefore, the control unit of this facsimile apparatus compares the recording medium length detected by the size detection plate with the leading and trailing end lengths detected by the signal from the pre-registration sensor to determine whether or not the recording medium has been double fed. Judging.

  When the recording medium is double-fed, the control unit of this facsimile apparatus performs double feeding by further using the position of the image appearing on the recording medium (the value of the margin length on the leading end side of the conveyed recording medium). The image recording position on a plurality of recording media is determined. When an image is stored on one of a plurality of recording media that are double-fed and recorded, the control unit performs a reception end process. However, when an image is recorded across a plurality of recording media that have been multi-fed, the control unit performs control to record the same image as the image that has been recorded across the newly fed recording medium. After that, reception end processing is performed.

Japanese Patent Laid-Open No. 7-41207

  In the facsimile apparatus described in Patent Document 1, when an image is recorded across a plurality of multi-fed recording media, the control unit newly feeds the same image as the image recorded across the recording medium. Control to record on the recording medium. At this time, each of the recording media on which the images are fed over and recorded over the same has a part of the image recorded on one side, but no image is recorded on the other side. Therefore, in many cases, an image can be recorded on the other surface of the plurality of recording media. However, in this facsimile apparatus, no image is recorded on the other surface of the plurality of recording media. Further, it is not considered to effectively use the other surface of the plurality of recording media. For this reason, there has been a problem that all of a plurality of recording media that have been double-fed and recorded across one side of the image are wasted.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to record an image across one side of a plurality of double-fed recording media, and the image is not recorded normally. In this case, if the user desires, a recording medium in which the same image as the image recorded across the other side of one of the recording media is recorded, and the image is not normally recorded on one side It is an object of the present invention to provide a recording apparatus capable of reusing data.

  In a recording apparatus in which an image can be recorded on both sides of a recording medium by a recording unit, the feeding mechanism having a feeding roller for feeding the recording medium is in contact with the feeding roller on the surface of the recording medium A transport mechanism that transports the recording medium in a predetermined transport direction from the feeding mechanism toward the recording unit such that a surface opposite to the surface faces the recording unit, and a first roller that rotates in the forward and reverse directions The recording medium is sandwiched between the first roller, the recording medium is conveyed in the predetermined conveying direction in cooperation with the first roller by the normal rotation of the first roller, and the reverse rotation of the first roller is performed. And a switchback mechanism having a second roller that cooperates with the first roller to convey the recording medium in a direction opposite to the predetermined conveying direction, and a drive unit that drives the first roller in the forward and reverse rotational directions. , Conveyed by the reverse rotation of the first roller A reversing mechanism for reversing the front and back of the recording medium to be conveyed toward the recording unit, a single-sided recording mode for recording an image on one side of the recording medium, and a double-sided recording mode for recording an image on both sides of the recording medium, A mode selection unit that selects any one of the plurality of recording media, and when the single-sided recording mode is selected, a plurality of recording media that are double-fed when a plurality of recording media are double-fed from the feeding mechanism When an image is recorded across one side of one recording medium, the same image as the one recorded across the other side of one recording medium of the multiple fed recording media A re-recording setting unit including an operation unit operable to set a re-recording mode for recording an image by a user, a multi-feed determining unit for determining that a recording medium is double-fed from the feeding mechanism, and an image On multiple recording media An image determination unit that determines whether or not recording is performed, and a rear end of the recording medium that is most rearward in the predetermined transport direction among the plurality of multi-feed recording media is the first roller and the A position determination unit that determines whether or not the rear end of the other recording medium is positioned more than a predetermined value on the downstream side of the holding position when positioned at the holding position by the second roller; Among the plurality of recording media, the leading edge of the recording medium that precedes in the predetermined transport direction reaches the clamping position, and then the trailing edge of the recording medium that follows most reaches the clamping position; and A predetermined amount determining unit that determines, as a predetermined amount, a normal rotation amount of the first roller until a rear end of another recording medium is conveyed more than the predetermined value downstream from the clamping position; and the double-sided recording mode Is selected, the multifeed decision If the image determination unit determines that the image is recorded across a plurality of recording media, the rear end of all of the plurality of recording media that have been multi-fed A first control function for controlling the drive of the drive unit so that the first roller rotates forward until the first roller is conveyed more than the predetermined value downstream from the clamping position, and the re-recording in the single-sided recording mode. When the re-recording mode is set by the setting unit, the multi-feed determining unit determines that the multi-feed has been performed, and the image determining unit determines that an image is recorded across a plurality of recording media. In addition, when the rear end of the most subsequent recording medium is positioned at the holding position, the position determination unit moves the rear end of the other recording medium away from the holding position by the predetermined value or more. If the first position is determined, The roller controls the drive of the drive unit so that the leading end of the leading recording medium of the plurality of multi-fed recording media reaches the clamping position and then reverses after the predetermined amount of normal rotation. A second control function for controlling the operation of the recording unit so as to record the same image as the image recorded across the recording medium conveyed by being reversed by the reversing mechanism. And a control unit having a function.

  According to this configuration, when the recording medium is double-fed and an image is recorded across one side of the multiple fed recording media, one of the recordings is recorded in the single-sided recording mode. When it is set to record the same image as the image recorded across the other side of the medium, that is, the user effectively uses the other side of the recording medium where the image is recorded across one side. If desired, the same image as the image recorded across the other side of one of the recording media having a part of the image recorded on one side is recorded. The Therefore, in this case, the waste of the recording medium can be reduced.

  3. The recording apparatus according to claim 2, wherein the predetermined amount determination unit includes a rearmost recording medium after the leading edge of the recording medium that precedes the plurality of multi-fed sheets reaches the clamping position. Until the end reaches the clamping position, and the trailing edge of the other recording medium is conveyed further downstream than the clamping position by a length corresponding to the radius of the first roller or the second roller. The normal rotation amount of the first roller is determined as the predetermined amount.

  According to this configuration, when the first roller is rotated forward by a predetermined amount, the trailing end of the preceding recording medium among the plurality of multi-fed recording media is closer to the first roller or the second roller than the holding position. It is transported downstream by a length corresponding to the radius. At this time, the preceding recording medium is reliably separated by its own weight from the most subsequent recording medium sandwiched between the first roller and the second roller. Therefore, the preceding recording medium is not conveyed to the reversing mechanism even if the first roller is reversed. Therefore, by transporting the trailing end of the preceding recording medium to the downstream side by a length corresponding to the radius of the first roller or the second roller from the sandwiching position, the most of the multiple recording media that are multi-fed. Only one subsequent sheet can be reliably conveyed to the reversing mechanism.

  The recording apparatus according to claim 3, wherein a recording medium length storage unit that stores a value of the length of one recording medium, and a leading end of the conveyed recording medium or recording sheets in the predetermined conveying direction. A leading-end length calculating unit that calculates a length value to the trailing end, and a deviation length value based on a value obtained by subtracting a value stored in the recording medium length storage unit from a value calculated by the leading-end length calculating unit A deviation length calculation unit, and the image determination unit calculates a deviation length value calculated by the deviation length calculation unit from a leading edge of a recording medium to be conveyed. If it is smaller, the image is determined to be recorded across a plurality of recording media.

  According to this configuration, it is determined whether or not an image is recorded across a plurality of recording media on which double feeding is performed, depending on whether or not the margin length value is smaller than the deviation length value. Therefore, it can be reliably determined that an image is recorded across a plurality of recording media that have been multi-fed.

  5. The recording apparatus according to claim 4, wherein when the value of the deviation length is larger than the predetermined value, the position determination unit is the most in the predetermined transport direction among the plurality of multi-fed recording media. When the trailing end of the recording medium to be followed is positioned at the clamping position, it is determined that the trailing ends of the other recording media are positioned at the predetermined value or more downstream from the clamping position.

  According to this configuration, it is possible to easily determine whether only the most subsequent recording medium among the plurality of recording media that have been multi-fed is conveyed to the reversing mechanism.

  6. The recording apparatus according to claim 5, wherein the predetermined amount determination unit determines the predetermined amount based on a value calculated by the leading and trailing end length calculation unit.

  According to this configuration, the predetermined amount determination unit determines the predetermined amount using the leading and trailing end lengths used for the determination by the image determination unit. Thus, the predetermined amount can be easily determined without newly calculating a value for determining the predetermined amount.

  The recording apparatus according to claim 6, wherein the recording medium that is conveyed in the predetermined conveyance direction by the normal rotation of the first roller and the rear end of which is conveyed more than the predetermined value downstream from the clamping position is discharged. And a discharge part.

  According to this configuration, the recording medium whose rear end is conveyed to the downstream side by a predetermined value or more with respect to the clamping position due to normal rotation of the first roller is discharged to the discharge unit. On the other hand, the recording medium whose rear end has reached the clamping position due to normal rotation of the first roller is conveyed to the reversing mechanism due to reverse rotation of the first roller. Therefore, whether the recording medium is discharged to the discharge portion or transferred to the reversing mechanism is determined depending on whether the rear end of the recording medium is transported a predetermined value or more downstream from the sandwiching position or transported to the sandwiching position. Can be switched.

  According to the recording apparatus of the present invention, when an image is recorded across one side of a plurality of multi-fed recording media, that is, a part of the image is recorded on the multi-fed recording media. In this case, the same image as the image recorded across the other surface of one of the recording media is recorded according to the user's request, so that the waste of the recording medium can be reduced.

1 is an external perspective view of a multifunction machine 10 according to an embodiment of the present invention. 1 is a schematic sectional view of a printer unit 14 according to an embodiment of the present invention. Explanatory drawing which shows the state which the switching flapper 74 of the switching part 26 concerning embodiment of this invention is located in a discharge position in order to guide a recording paper to the paper discharge part 23 In the state where the switching flapper 74 of the switching unit 26 according to the embodiment of the present invention is located at the discharge position, the trailing edge of the recording paper P2 that follows and the trailing edge of the preceding recording paper P1, and the switchback roller pair Explanatory drawing which shows the positional relationship with 56 clamping positions. Explanatory drawing which shows the state which the switching flapper 74 of the switching part 26 based on embodiment of this invention is located in a re-conveying position in order to guide a recording paper to the re-conveying part 28. 1 is a block diagram showing a control system of a multifunction machine 10 according to an embodiment of the present invention. The flowchart which shows the recording operation performed by the control part 96 which concerns on embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate.

  FIG. 1 is an external perspective view of a multifunction machine 10 according to an embodiment of the present invention. In the following description, the vertical direction 1 is defined with reference to the state of FIG. 1 in which the multifunction machine 10 is installed, and the front-rear direction 2 is defined with the side on which the operation panel 12 is provided as the front side. The horizontal direction 3 is defined when the multifunction machine 10 is viewed from the front side.

  The multifunction machine 10 is a substantially rectangular parallelepiped that is longer in the left-right direction and the front-rear direction than in the up-down direction. The multifunction machine 10 includes a printer unit 14 at the bottom, a scanner unit 16 at the top, and an operation panel 12 at the front top. The operation panel 12 includes a first input button 89 and a second input button 91 described later. Details of the printer unit 14 will be described below. The description of the details of the scanner unit 16 is omitted.

[Configuration of Printer Unit 14]
As shown in FIG. 2, the printer unit 14 includes an image recording unit 18, a paper feed unit 20, a paper discharge unit 23, a main transport unit 24, a switching unit 26, a re-transport unit 28, and a detection unit 29. And have. The main transport unit 24 transports the recording paper from the paper supply unit 20 to the switching unit 26 via the image recording unit 18. The switching unit 26 switches the conveyance direction of the recording paper in order to record an image on the other side of the recording paper. The re-conveying unit 28 conveys the recording paper whose conveying direction has been switched to the main conveying unit 24 again. Each configuration will be described below.

[Image Recording Unit 18]
The image recording unit 18 is disposed at the upper part of the printer unit 14 and records an image on a recording sheet. The image recording unit 18 includes a recording head 30, a carriage 32 that supports the recording head 30, and a platen 60 that supports the recording paper so as to face the recording head 30.

  The recording head 30 can eject ink droplets, and ink is supplied from an ink cartridge (not shown).

  The carriage 32 on which the recording head 30 is supported can reciprocate in the left-right direction. The carriage 32 is connected to a CR motor 34 (see FIG. 6) that is a drive source. The carriage 32 reciprocates in the left-right direction when the rotation of the CR motor 34 is transmitted through a first transmission mechanism (not shown) including a plurality of gears. As the carriage 32 reciprocates, the recording head 30 ejects ink droplets. As a result, an image is recorded on the recording paper facing the recording head 30.

  The platen 60 is a member that is disposed below the recording head 30 and extends across the front and rear and the left and right. The platen 60 supports the recording paper being recorded on the upper surface of the platen 60 substantially horizontally.

[Paper Feeder 20]
The paper feed unit 20 includes a paper feed cassette 22 on which recording paper can be stacked, and a paper feed mechanism 36. The recording paper fed by the paper feeding mechanism 36 is guided by a main transport unit 24 described later, and an image is recorded on the recording paper by the image recording unit 18.

  The paper feed cassette 22 is a box-like member that is disposed at the bottom of the printer unit 14 and has an open upper surface. Various sizes of recording paper can be loaded on the paper feed cassette 22. The paper feed cassette 22 can be inserted and removed in the front-rear direction from an opening 37 (see FIG. 1) formed on the front surface of the printer unit 14.

  The paper feed mechanism 36 is disposed above the paper feed cassette 22. The basic configuration of the paper feed mechanism 36 is known, and the configuration is disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-247542. Hereinafter, the configuration of the paper feed mechanism 36 will be briefly described. The paper feed mechanism 36 includes a paper feed roller 38 that feeds the stacked recording paper and a support arm 40 that supports the paper feed roller 38.

  The paper feed roller 38 is rotatably provided, and is provided so as to be able to contact and separate from the recording paper loaded in the paper feed cassette 22. The paper feed roller 38 is connected to a paper feed motor 42 (see FIG. 6) that is a drive source. The paper feed roller 38 rotates by receiving the rotation of the paper feed motor 42 via a second transmission mechanism (not shown) composed of a plurality of gears. The paper feed roller 38 rotates forward by the rotation of the LF 42 motor in the forward direction, and transports the recording paper toward the main transport unit 24. The paper feed roller 38 is configured not to rotate when the paper feed motor 42 rotates in the reverse direction.

  The support arm 40 is a rod-shaped member that supports the paper feed roller 38 on one end side and is supported by the shaft 41 on the other end side. The support arm 40 is provided so as to be rotatable about a shaft 41. The shaft 41 is fixed to a frame (not shown) of the printer unit 14.

  Further, the support arm 40 is urged so that the paper feed roller 38 moves downward by its own weight or a spring (not shown). As a result, the paper feed roller 38 contacts the upper surface of the recording paper loaded in the paper feed cassette 22. When the paper feed cassette 22 is inserted and removed, the support arm 40 rotates about the shaft 41 so that the paper feed roller 38 moves upward. As a result, the paper feed roller 38 moves upward and retreats from the insertion / extraction area of the paper feed cassette 22.

[Paper Discharge Unit 23]
As shown in FIG. 1, the paper discharge unit 23 is disposed above the front side of the paper feed cassette 22, and supports the recorded recording paper that has been discharged on the upper surface of the paper discharge unit 23. The paper discharge unit 23 is configured integrally with the paper feed cassette 22 and can be inserted into and removed from the printer unit 14 together with the paper feed cassette 22.

[Main transport section 24]
As shown in FIG. 2, the main transport unit 24 is arranged from the vicinity of the upper end of the paper feed cassette 22 through the image recording unit 18 to the rear of the switching unit 26 described later. The main transport unit 24 transports the recording paper so that the recording paper reaches the switching unit 26 after passing through the image recording unit 18. The main transport unit 24 includes a curved guide 58 and a discharge guide 62 that guide the recording paper, and a transport roller pair 52 and a discharge roller pair 54 that transport the recording paper. The recording paper conveyed by the main conveyance unit 24 is conveyed on the main conveyance path 50.

  The curved guide 58 is a generally arcuate member that extends from the downstream side of the paper supply unit 20 to the upstream side of the image recording unit 18 and has an inner side of the printer unit 14 as a center. Here, the upstream side and the downstream side refer to the upstream side and the downstream side in the transport direction 55 when the recording paper is transported on the main transport path 50 in the transport direction 55 indicated by the two-dot chain arrow in FIG. It is. Hereinafter, they are simply referred to as “upstream side” and “downstream side”. The recording paper conveyed by the paper supply roller 38 is conveyed so as to make a U-turn from below to above along the inner surface of the curved guide 58. For this reason, the recording paper is conveyed such that the lower surface opposite to the upper surface with which the paper feed roller 38 is in contact is opposed to the recording head 30. When the recording paper is transported by the paper feed roller 38 toward the main transport unit 24, another recording paper is put on one recording paper transported by the paper feeding roller 38, and two recording papers In some cases, so-called double feeding occurs. When the recording paper is double-fed, the recording paper abutted by the paper feed roller 38 is often transported prior to the recording paper being carried. Therefore, after the two recording sheets are fed in a state where they are shifted and overlapped, when the paper is turned upside down by the curved guide 58, the subsequent recording sheet P2 is placed on the preceding recording sheet P1 so as to partially overlap. State (see FIG. 3).

  The discharge guide 62 is a member that extends from the downstream side of the image recording unit 18 to the upstream side of the switching unit 26 described later. The discharge guide 62 supports the recorded recording paper substantially horizontally on the upper surface of the discharge guide 62.

  The conveyance roller pair 52 is disposed in front of the curved guide 58 and behind the image recording unit 18. The conveyance roller pair 52 includes a conveyance roller 64 that is driven, and a first pinch roller 66 that is pressed against the conveyance roller 64 and rotates following the conveyance roller 64. The transport roller pair 52 transports the recording paper transported along the curved guide 58 toward the image recording unit 18. The first pinch roller 66 is disposed below the conveying roller 64.

  The discharge roller pair 54 is disposed in front of the image recording unit 18 and behind the discharge guide 62. The discharge roller pair 54 includes a driven discharge roller 68 and a second pinch roller 70 that is in pressure contact with the discharge roller 68 and rotates following the discharge roller 68. The discharge roller pair 54 conveys the recording paper on which the image is recorded by the image recording unit 18 toward the discharge guide 62. The second pinch roller 70 is disposed above the discharge roller 68.

  The conveyance roller 64 and the discharge roller 68 are connected to a PF motor 72 (see FIG. 6) that is a drive source. The conveyance roller 64 and the discharge roller 68 are rotated by the rotation of the PF motor 72 transmitted through a third transmission mechanism (not shown) including a plurality of gears. The conveyance roller 64 and the discharge roller 68 are configured to rotate only in the direction in which the recording paper is conveyed further downstream from the arrangement position of each roller.

[Switching unit 26]
The switching unit 26 is disposed in front of the discharge guide 62. The switching unit 26 switches the transport direction to whether the recording paper transported from the main transport unit 24 is discharged to the paper discharge unit 23 or guided to a re-transport unit 28 described later. The switching unit 26 includes a switchback roller pair 56 that rotates in the forward and reverse directions to switch the recording paper conveyance direction, and a switching flapper 74 that switches the recording paper guide direction.

  The switchback roller pair 56 is disposed downstream of the discharge guide 62 and upstream of the paper discharge unit 23. The switchback roller pair 56 includes a switchback roller 76 that is driven, and a third pinch roller 78 that is in pressure contact with the switchback roller 76 and rotates following the switchback roller 76. The switchback roller 76 can rotate in forward and reverse directions. The recording paper conveyed on the conveyance guide 62 is conveyed toward the paper discharge unit 23 by the normal rotation of the switchback roller 76. On the other hand, the recording paper is conveyed in the reverse direction by the reverse rotation of the switchback roller 76. The third pinch roller 78 is disposed above the switchback roller 76.

  The switchback roller 76 is connected to a paper feed motor 42 that is a drive source. The switchback roller 76 rotates when the rotation of the paper feed motor 42 is transmitted through a fourth transmission mechanism (not shown) including a plurality of gears. The paper feed motor 42 can be driven in forward and reverse directions, and the switchback roller 76 rotates in the forward and reverse directions as the paper feed motor 42 rotates.

  The switching flapper 74 is disposed behind the third pinch roller 78 and switches the recording paper guide direction. The switching flapper 74 includes a first auxiliary roller 80, a flapper portion 81, and a second auxiliary roller 82. The first auxiliary roller 80 is rotatably supported by the frame of the printer unit 14. The flapper portion 81 extends rearward from the first auxiliary roller 80 and is provided so as to be rotatable about the first auxiliary roller 80. The second auxiliary roller 82 is disposed at the extended end of the flapper portion 81 and moves up and down as the flapper portion 81 rotates.

  The switching flapper 74 has a “discharge position” and a “re-transfer position” described below.

  As shown in FIG. 3, at the discharge position of the switching flapper 74, the second auxiliary roller 82 is positioned at substantially the same height as the first auxiliary roller 80. At this time, the switching flapper 74 guides the recording paper conveyed on the discharge guide 62 to be conveyed toward the paper discharge unit 23.

  As shown in FIG. 5, at the re-conveying position of the switching flapper 74, the second auxiliary roller 82 is positioned obliquely below and behind the first auxiliary roller 78. At this time, the switching flapper 74 guides the recording paper conveyed by the reverse rotation of the switchback roller pair 56 to be conveyed toward the re-conveying unit 28.

  The switching flapper 74 is connected to a paper feed motor 42 that is a drive source. The switching flapper 74 is rotated by the rotation of the paper feed motor 42 being transmitted via a fifth transmission mechanism (not shown) including a plurality of gears.

  The switching flapper 74 is rotated to the discharge position by the rotation of the paper feed motor 42 in the forward direction, and is rotated to the re-transport position by the rotation in the reverse direction. When the switching flapper 74 is located at the discharge position, the recording paper conveyed on the discharge guide 62 reaches the switchback roller pair 56 via the lower side of the switching flapper 74. At this time, since the paper feed motor 42 is rotating in the forward direction, the recording paper is further conveyed downstream by the forward rotation of the switchback roller 76. Note that the recording paper whose rear end is conveyed downstream of the position where the switchback roller pair 56 is held by the forward rotation of the switchback roller 76 falls due to its own weight and is discharged to the paper discharge unit 23.

  When the switchback roller 76 rotates reversely after normal rotation, the switching flapper 74 rotates to the re-conveying position in synchronization with the reverse rotation. When the switchback roller 76 starts reverse rotation, the trailing edge of the recording paper in the conveyance direction 55 is sandwiched by the switchback roller pair 56. Therefore, when the switchback roller 76 rotates in the reverse direction and the switching flapper 74 rotates to the reconveying position, the recording paper sandwiched by the switchback roller pair 56 is guided to the reconveying unit 28 described later by the switching flapper 74.

[Re-transport unit 28]
As shown in FIG. 2, the re-conveying unit 28 passes from between the lower back of the switchback roller pair 56 to the front of the curved guide 58 constituting the main conveying unit 24, passing between the platen 60 and the paper feeding unit 20. It is arranged over. The re-conveying unit 28 conveys the recording paper conveyed from the switching unit 26 toward the curved guide 58. The re-conveying unit 28 includes a re-conveying guide 84 that guides the recording paper, and a re-conveying roller pair 86 that conveys the recording paper.

  The re-conveying guide 84 is a member that extends from obliquely below the switchback roller pair 56 to the front of the curved guide 58. The re-transport guide 84 supports the recording paper transported from the switching unit 26 on the upper surface of the re-transport guide 84. The recording paper conveyed on the re-conveying guide 84 is guided by the curved guide 58 and conveyed toward the image recording unit 18 so as to make a U-turn again from below to above.

  The re-conveying roller pair 86 is disposed near the center of the re-conveying guide 84 in the front-rear direction. The re-conveying roller pair 86 includes a re-conveying roller 88 that is driven, and a fourth pinch roller 90 that is pressed against the re-conveying roller 88 and rotates following the re-conveying roller 88. The re-conveying roller 88 conveys the recording paper conveyed on the re-conveying guide 84 toward the curved guide 58. The fourth pinch roller 90 is disposed above the re-transport roller 88.

  The re-conveying roller 88 is connected to a PF motor 72 (see FIG. 6) that is a driving source. The re-conveying roller 88 is rotated by the rotation of the PF motor 72 transmitted through a sixth transmission mechanism (not shown) including a plurality of gears. The re-conveying roller 88 is configured to rotate only in the direction of conveying the recording paper further downstream.

[Detection unit 29]
The detection unit 29 includes a registration sensor 51 that detects the presence or absence of recording paper, and a sheet sensor 53. The registration sensor 51 is disposed on the upstream side of the image recording unit 18, the sheet sensor 53 is disposed on the downstream side of the image recording unit 18, and both sensors detect the presence or absence of recording paper in the main conveyance path 50. The registration sensor 51 and the sheet sensor 53 each include a detector (not shown) and an optical sensor (not shown). The detector is arranged so as to cross the main transport path 50 and is configured to be able to protrude or retract from the main transport path 50. The optical sensor is turned on or off by the protrusion or withdrawal of the detector. Accordingly, the position of the leading or trailing edge of the recording paper in the main transport path 50 is detected by changing the recording paper to a state where the detector protrudes or retracts. Here, the leading edge and the trailing edge of the recording paper are the leading edge and the trailing edge of the conveyed recording paper.

[Configuration of Control System of Embodiment]
Next, a control system of the multifunction machine 10 shown in FIG. 6 will be described. The control system controls the overall operation of the multifunction machine 10 including the scanner unit 16, but only control of the operation of the printer unit 14 will be described here.

  The control system includes a first storage unit 92 that stores recording information for recording an image on recording paper, a calculation unit 94 that performs each calculation described below based on the detection result of the detection unit 29, and a switchback roller 76 that rotates forward. A predetermined amount determining unit that determines a predetermined amount to be performed, and a control unit 96 that controls driving of the image recording unit 18 and each driving source. Each drive source includes a CR motor 34, a paper feed motor 42, a PF motor 72, and the like. The predetermined amount determination unit includes a second storage unit 97 and a calculation unit 94 which will be described later.

  The first storage unit 92 stores recording information for recording an image on recording paper. The recording information is information included in the recording operation execution instruction input from the operation panel of the multifunction machine 10 or an external input device such as a PC. When an instruction to execute a recording operation is input from the operation panel 12 of the multifunction machine 10 or an external input device such as a PC, the control unit 96 described later stores recording information included in the input instruction in the first storage unit 92. Remember.

  The recording information includes image data including an image to be recorded on a recording sheet and a margin length value, and recording sheet data including a recording sheet length. Here, the recording paper length is a length value in the conveyance direction of one recording paper. In the case of single-side recording in which an image is recorded on one side of the recording paper, the image data includes a first image to be recorded on one side of the recording paper and a margin length value.

  The calculation unit 94 calculates the length of the leading and trailing edges, which is the length from the leading edge to the trailing edge of one or two sheets of recording paper being conveyed, and the length of the misalignment between the two sheets of recording paper that have been double fed. A value (hereinafter simply abbreviated as “deviation length”) is calculated. In addition, the calculation unit 94 determines whether the deviation length is larger or smaller than each value described later. The calculation unit 94 outputs each calculated value and each comparison result to the control unit 96.

  The front / rear end length is calculated based on the detection result of the registration sensor 51. The calculation unit 94 calculates the leading and trailing edge length, which is the value of the length from the leading edge to the trailing edge, from the leading edge and trailing edge positions of the recording paper detected by the registration sensor 51. That is, the front / rear end length is a value of the length from the front end to the rear end of one or two recording sheets to be transported regardless of whether or not they are double-fed.

  The deviation length is calculated based on the leading and trailing edge lengths and the recording paper length stored in the first storage unit 92. The calculation unit 94 calculates a value obtained by subtracting the recording paper length and the set value “α” from the leading and trailing edge lengths as the deviation length. In the present embodiment, the set value “α” is set to “2 mm” in consideration of the conveyance error of the recording paper and the detection error of the registration sensor 51. The set value “α” is a value stored in the second storage unit 97.

  Further, the arithmetic unit 94 determines whether or not the deviation length is larger than “0”. When the misalignment length is greater than “0”, the control unit 96 determines that the two recording media are fed in a state where they are shifted in the transport direction 55 and overlapped, that is, they are double fed.

  The calculation unit 94 uses the value of the margin length from the leading edge of the conveyed recording paper among the margin length values included in the first image data (hereinafter simply referred to as “leading margin length”). Judge whether it is large or not. As a result, it can be determined whether or not the first image is recorded across the two sheets of recording paper that have been multi-fed. Note that this determination is necessary only when the recording paper is double-fed, and is therefore performed only when it is determined that the misalignment length is greater than “0”.

  Here, when the misalignment length is larger than the leading edge margin length, the first image is recorded across the two fed sheets of recording paper. On the other hand, when the misalignment length is smaller than the leading edge margin length, the first image is stored on one of the two sheets of the double-fed recording paper.

  The calculation unit 94 determines whether or not the deviation length is greater than a value R (see FIG. 4) corresponding to the radius of the switchback roller 76 (hereinafter simply referred to as “roller radius length”). As a result, it can be determined whether or not only the recording paper P2 that follows the two of the two recording papers that have been multi-fed can be reliably conveyed to the re-conveying unit 28. This determination is necessary only when the recording paper is double-fed and the first image is recorded across the two recording papers that have been double-fed, so that the deviation length is determined to be greater than “0”. It is performed only when it is determined that the deviation length is larger than the leading edge margin length.

  The case where the misalignment length is larger than the roller radius length R (see FIG. 4) is a case where only the following recording sheet P2 out of the two sheets of recording paper that have been multi-fed can be reliably conveyed to the reconveying unit 28. At this time, the preceding recording sheet P1 out of the two recording sheets that have been multi-fed is separated from the following recording sheet P2 and discharged to the sheet discharge section 23 (see FIG. 5). On the other hand, when the deviation length is smaller than the roller radius length R, it is a case where it is not certain that only the recording paper P2 that follows the two of the double-fed recording papers is conveyed to the re-conveying unit 28.

  Of the two sheets fed double, the separating recording paper P2 is transported to the re-conveying unit 28 and the preceding recording paper P1 is ejected to the paper ejecting unit 23. This is performed by switching from forward rotation of 76 to reverse rotation. Details of the separation of the two fed recording sheets will be described later.

  The predetermined amount determination unit includes a second storage unit 97 and a calculation unit 94. The predetermined amount determination unit uses the set value “α” stored in the second storage unit 97 and the leading and trailing end length calculated by the calculation unit 94 to set the value calculated by the calculation unit 94 to the correct value by the switchback roller 76. It is determined as a predetermined amount to roll. The predetermined amount of forward rotation of the switchback roller 76 means that the leading edge of one sheet of recording paper being conveyed or the leading edge of the preceding recording sheet P1 among the two sheets of recording paper being fed is nipped by the switchback roller pair 56. After reaching the position, until the trailing edge of one sheet of conveyed recording paper or the trailing edge of recording paper P2 of two sheets fed double is sandwiched between the switchback roller pair 56 This is the forward rotation amount of the switchback roller 76 that conveys the recording paper. The predetermined amount corresponds to an amount of the recording paper that is transported by the length of the front and rear ends. Therefore, the predetermined amount is determined based on a value obtained by subtracting the set value “α” from the front and rear end lengths in consideration of the conveyance error and the length of the recording paper necessary to be held between the switchback roller pair 56. The At this time, the control unit 96 determines whether or not the leading edge of the conveyed recording paper has reached the holding position of the switchback roller pair 56 based on the detection result of the sheet sensor 53.

  When two sheets of recording paper are fed when the switchback roller 76 is rotated forward by the predetermined amount, as shown in FIG. 4, the recording paper that follows is fed out of the two fed sheets of recording paper as shown in FIG. The rear end of P2 is located upstream of the position where the switchback roller pair 56 is sandwiched and downstream of the discharge guide 62, but the rear end of the preceding recording paper P1 is sandwiched between the switchback roller pair 56. It is conveyed downstream from the position by at least the roller radius length R. The preceding recording paper P1 whose rear end is conveyed downstream from the nipping position of the switchback roller pair 56 by the roller radius length R or more is separated from the following recording paper P2 by its own weight, as shown in FIG. The paper is discharged to the paper discharge unit 23. On the other hand, the subsequent recording paper P2 is conveyed in the reverse direction when the switchback roller 76 is reversed, and is guided to the re-conveying unit 28.

  In this embodiment, the mode selection unit is provided to select one of a single-sided recording mode for recording an image on one side of the recording paper and a double-sided recording mode for recording an image on both sides of the recording paper. It is done. The mode selection unit includes a first input button 89 (see FIG. 1) of the operation panel 12, an internal fixed memory (not shown) of the control unit 96 that stores information input by the first input button 89, a control unit 96 and some processing. When one of the single-sided recording mode and the double-sided recording mode is selected by operating the first input button 89, the control unit 96 stores information regarding the selected mode in the internal fixed memory of the control unit 96. . The control unit 96 determines information related to the mode stored in the internal fixed memory of the control unit 96 and executes processing described later.

  In the present embodiment, when the re-recording setting unit records the first image across one side of two sheets of double-fed recording paper, the other side of one of the recording papers It is provided for setting a re-recording mode for recording the first image. The re-recording setting unit includes a second input button 91 (see FIG. 1) of the operation panel, an internal fixed memory of the control unit 96 that stores information input by the second input button 91, and a part of the control unit 96. Processing. The re-recording setting unit sets whether or not the control unit 96 executes the re-recording mode. The re-recording mode is a mode that can be set in the single-sided recording mode. When the user sets the re-recording mode with the second input button 91, the control unit 96 stores that the re-recording mode is set in the internal fixed memory of the control unit 96. The control unit 96 determines whether or not the fact that the re-recording mode has been set is stored in the internal fixed memory of the control unit 96, and executes processing to be described later.

  When the recording paper is double fed and the first image is recorded across one side of the two double fed recording papers, and the first image is not normally recorded, one of the first images is recorded. When the user desires to effectively use the other side of the recording paper recorded on one side, the user can set the re-recording mode. The user prefers to effectively use the other side of the recording paper in which a part of the first image is recorded on one side, rather than recording the first image on a new recording paper. In this case, the user sets the re-recording mode. On the other hand, the user has priority over recording the first image on a new recording sheet over effectively using the other side of the recording sheet in which a part of the first image is recorded on one side. If desired, the user does not set the re-recording mode. Thereby, an image can be recorded according to a user's request. When the re-recording mode is set, the other side of the recording paper on which a part of the first image is recorded on one side is used effectively, so that waste of the recording paper can be reduced. .

[Recording operation]
Next, a recording operation executed by the control unit 96 of the multifunction machine 10 will be described with reference to FIG. Each step shown in FIG. 7 is a process executed by the control unit 96. A control program for executing each process of the flowchart shown in FIG. 7 is stored in the internal fixed memory of the control unit 96.

  When a recording operation execution instruction is input from the operation panel 12 of the multifunction machine 10 or an external input device such as a PC, the control unit 96 stores the recording information of the information included in the input instruction in the first storage unit 92. To remember. The control unit 96 confirms the recording information, and confirms the first image data including at least the first image and the margin length and the recording sheet data including the recording sheet length (S1).

  In step S <b> 2, the control unit 96 drives the paper feed motor 42 so that the paper feed roller 38 rotates. The paper feed roller 38 rotates in contact with the upper surface of the recording paper loaded on the paper feed cassette 22. By this rotation, the recording paper is fed from the paper feed cassette 22 and is conveyed along the curved guide 58 so as to make a U-turn from below to above.

  In step S3, the control unit 96 checks whether or not the registration sensor 51 has detected the leading edge of the recording paper. If NO is determined in step S3, the control unit 96 executes the process of step S2 so that the recording paper is further conveyed.

  On the other hand, if YES is determined in step S3, the control unit 96 drives the PF motor 72 so that the transport roller 64 and the discharge roller 68 are rotated (S4). The leading edge of the recording paper that has passed through the registration sensor 51 reaches the conveyance roller pair 52, and the recording paper is conveyed onto the platen 60 by the conveyance roller pair 52.

  In step S5, the control unit 96 records the first image on the front surface of the recording paper conveyed to the platen 60 based on the first image data stored in the first storage unit 92. The operation of the image recording unit 18 is controlled. In the present embodiment, the surface of the recording paper on which the first image is recorded is the surface opposite to the upper surface of the recording paper with which the paper feed roller 38 is in contact. The leading edge of the recording paper that has passed between the recording head 30 and the platen 60 is conveyed onto the discharge guide 62 by the discharge roller pair 54. The recording medium conveyed on the discharge guide 62 is detected by the sheet sensor 53.

  In step S6, the control unit 96 checks whether the registration sensor 51 has detected the trailing edge of the recording paper. If NO is determined in step S6, the control unit 96 executes the process of step S25 so that the recording paper is further conveyed. On the other hand, when it is determined YES in step S6, the control unit 96 executes the process of step S7. When the registration sensor 51 detects the trailing edge of the recording paper, the recording paper is in the middle of recording the first image by the image recording unit 18 or after the first image is recorded.

  In step S <b> 7, the control unit 96 controls the calculation unit 94 so as to calculate the deviation length after the trailing edge of the conveyed recording paper passes through the registration sensor 51.

  In step S <b> 8, the control unit 96 confirms the leading edge margin length stored in the first storage unit 92.

  In step S <b> 9, the control unit 96 confirms the comparison result between the deviation length in the calculation unit 94 and the value “0”.

  The case where NO is determined in step S9 is a case where the arithmetic unit 94 determines that the deviation length is smaller than or equal to “0”. In this case, the control unit 96 determines that the recording paper has not been double fed, and executes the process of step S22. In step S22, the control unit 96 checks the internal fixed memory of the control unit 96, and determines whether or not the stored information regarding the mode is the single-sided recording mode.

  If YES is determined in step S22, the single-sided recording mode has been selected. In this case, the control unit 96 discharges the recording paper (S21). On the other hand, if NO is determined in step S22, the double-sided recording mode has been selected. In this case, the control unit 96 performs a normal back side recording operation (S23). A detailed description of the normal back side recording operation is omitted. In the normal back side recording operation, the control unit 96 executes at least the processes of steps S15 to S19, records the image to be recorded on the back side instead of the first image in the process of step S20, and then performs the process of step S21. Execute.

  If YES is determined in step S9, the calculation unit 94 determines that the deviation length is greater than “0”. In this case, the control unit 96 determines that two sheets of recording paper have been fed, and executes the process of step S10.

  In step S <b> 10, the control unit 96 confirms a comparison result between the shift length and the leading edge margin length in the calculation unit 94. Based on the comparison result, the control unit 96 determines whether or not the first image is recorded across the two recording sheets that have been double-fed.

  The case where NO is determined in step S10 is a case where the calculation unit 94 determines that the deviation length is smaller than or equal to the leading edge margin length. If NO is determined in step S10, the first image is stored and recorded on the subsequent recording sheet P2 out of the two sheets of the recording paper that are double-fed. In this case, in the subsequent step S26, the control unit 96 checks the internal fixed memory of the control unit 96 and determines whether or not the information regarding the stored mode is the single-sided recording mode. If YES is determined in step S26, the control unit 96 discharges the two fed recording sheets to the paper discharge unit 23 (S21). If NO is determined in step S26, the control unit 96 checks the comparison result between the deviation length and the roller radius length R in the calculation unit 94 (S27).

  The case where NO is determined in step S27 is a case where the arithmetic unit 94 determines that the deviation length is smaller than or equal to the roller radius length R. In this case, the control unit 96 discharges the two fed recording sheets to the paper output unit 23 (S24), and then drives the paper supply motor 42 so that the paper supply roller 38 rotates ( S4), the recording paper is fed again. If it is determined NO in step S27, it is a case where it is not certain that only the recording paper P2 that follows will be conveyed to the re-conveying unit 28 among the two sheets of double-fed recording paper. Accordingly, since it is not certain that an image is recorded only on both sides of a single recording sheet, useless recording operation is prevented by discharging the double-fed recording sheets and starting over from the paper supply. be able to. If it is determined NO in S27 and the first image is being recorded on the recording paper by the image recording unit 18, the control unit stops the operation of the image recording unit 18 and performs recording. The paper is ejected. This can prevent useless recording operations. On the other hand, when YES is determined in step S <b> 27, the arithmetic unit 94 determines that the deviation length is larger than the roller radius length R. In this case, since only the recording paper P2 that follows the two of the double-fed recording papers can be reliably conveyed to the re-conveying unit 28, the control unit 96 can control the two double-fed recording sheets. A process of recording an image on the back side of one of the recording sheets is executed (S28). In step S28, after executing the processing from step S14 to step S19, the control unit 96 controls the operation of the image recording unit 18 to record an image to be recorded on the back surface instead of the processing in step S20. The process of S21 is executed. As a result, even if the recording paper is double-fed, an image can be recorded only on both sides of one recording paper.

  On the other hand, if YES is determined in step S10, it is a case where the calculation unit 94 determines that the deviation length is larger than the leading edge margin length. In this case, the control part 96 performs the process of step S11. If YES is determined in step S10, it is a case where the first image is recorded across two double-fed recording sheets. In step S11, the control unit 96 checks the internal fixed memory of the control unit 96, and determines whether or not the stored information regarding the mode is the single-sided recording mode.

  If NO is determined in step S11, the duplex recording mode has been selected. In this case, the control unit 96 discharges the double fed recording sheets to the paper discharge unit 23 (S24), and then drives the paper supply motor 42 so that the paper supply roller 38 rotates (S4). ), Start again from feeding the recording paper. At this time, the first image is recorded across one side of the two sheets of double-fed recording paper. Therefore, if NO is determined in step S11, an image cannot be recorded only on both sides of one recording sheet, so the two recording sheets that have been multi-fed are discharged and the paper supply is started again. If it is determined NO in step S11 and the first image is being recorded on the recording paper by the image recording unit 18, the control unit 18 stops the operation of the image recording unit 18. Step S24 is executed. This can prevent useless recording operations. On the other hand, if YES is determined in step S11, the single-sided recording mode is selected. In this case, the control part 96 performs the process of step S12.

  In step S <b> 12, the control unit 96 checks the internal fixed memory of the control unit 96 and determines whether or not the fact that the re-recording mode is set is stored in the internal fixed memory of the control unit 96. The re-recording mode is set when the recording paper is double-fed and the first image is recorded across one side of the two double-fed recording papers and the first image is not recorded normally. Whether the other side of one of the recording sheets is to be used effectively or whether the first image is recorded on a new recording sheet without setting the re-recording mode is determined by the user's wish. Thereby, an image can be recorded according to a user's request. When the re-recording mode is set, the other side of the recording paper on which a part of the first image is recorded on one side is used effectively, so that waste of the recording paper can be reduced. .

  If NO is determined in step S12, the re-recording mode is not set. In this case, if the first image is recorded over a plurality of recording sheets due to multiple feeding, and the first image is not normally recorded, the recording sheet of one of the recording sheets is reused. This is a case where the user desires to record the first image on a new recording sheet rather than using it. Therefore, the control unit 96 discharges the two fed recording sheets to the paper discharge unit 23 (S24), and then drives the paper feed motor 42 so that the paper feed roller 38 rotates (S4). Then, start again from feeding the recording paper. If it is determined NO in step S12 and the first image is being recorded on the recording paper by the image recording unit 18, the control unit 18 stops the operation of the image recording unit 18. Step S24 is executed.

  On the other hand, if YES is determined in step S12, the re-recording mode is set. In this case, when the first image is recorded over a plurality of recording sheets due to multiple feeding, and the first image is not normally recorded, the first image is recorded on a new recording sheet. This is also the case where the user desires to effectively use the other side of the recording paper on which a part of the first image is recorded to reduce waste of the recording paper. Therefore, if YES is determined in step S12, the control unit 96 continues to record the first image on the other side of the recording paper on which a part of the first image is recorded on one side. The process of S13 is executed. In this case, since the first image is recorded on the other surface of one of the two recording papers that have been recorded in such a manner that the first image is straddled across one surface. The waste of the recording medium can be reduced. In the present embodiment, step S11 is a part of the process of the control unit 96 constituting the mode selection unit, and step S12 is a part of the process of the control unit 96 constituting the re-recording setting unit.

  In step S <b> 13, the control unit 96 confirms a comparison result between the deviation length and the roller radius length R in the calculation unit 94.

  The case where NO is determined in step S13 is a case where the arithmetic unit 94 determines that the deviation length is smaller than or equal to the roller radius length R. In this case, the control unit 96 discharges the two fed recording sheets to the paper output unit 23 (S24), and then drives the paper supply motor 42 so that the paper supply roller 38 rotates ( S4), the recording paper is fed again. If NO is determined in step S13, it is ensured that only the recording paper P2 that follows is transported to the re-conveying unit 28 out of the two recording papers that are double-fed and recorded across the first image. This is not the case. Therefore, it is possible to prevent useless recording operations by discharging the two fed recording sheets and starting over from the paper supply. If it is determined NO in S13 and the first image is being recorded on the recording paper by the image recording unit 18, the control unit stops the operation of the image recording unit 18 and performs recording. The paper is ejected. This can prevent useless recording operations.

  On the other hand, when YES is determined in step S <b> 13, the arithmetic unit 94 determines that the deviation length is greater than the roller radius length R. In this case, the control part 96 performs the process of step S14. If YES is determined in step S13, of the two recording sheets that are double-fed and recorded across the first image, only the subsequent recording sheet P2 can be reliably conveyed to the re-conveying unit 28. It is.

  In step S14, the control unit 96 controls the calculation unit 94 so as to calculate a predetermined amount.

  In step S15, the control unit 96 drives the paper feed motor 42 so that the switchback roller 76 rotates forward by a predetermined amount. As a result, the two fed sheets of recording paper are separated. When the switchback roller 76 rotates forward by a predetermined amount, the trailing edge of the recording paper P2 that follows the two of the double-fed recording papers is located between the switchback roller pair 56. The rear end of the paper P1 is positioned on the downstream side of the roller radius length R or more from the holding position of the switchback roller pair 56 (see FIG. 4). At this time, since the preceding recording sheet P1 is not sandwiched between the switchback roller pair 56, it is separated from the subsequent sheet by its own weight and discharged to the sheet discharge section 23 (see FIG. 5). As a result, of the two sheets of recording paper that have been double-fed and recorded across the first image on one side, the preceding recording sheet P1 is ejected and the first recording sheet P2 on the other side is first. An image is recorded. Thus, since the first image is recorded using the other side of the recording paper on which a part of the first image is recorded on one side, waste of the recording paper can be reduced.

  In step S <b> 16, the control unit 96 drives the paper feed motor 42 in the reverse direction so that the switchback roller 76 rotates in the reverse direction. As a result, the recording paper whose rear end is sandwiched between the switchback roller pair 56 is conveyed in the reverse direction.

  Note that the switching flapper 74 is rotated to the re-transport position (see FIG. 5) by driving the paper feed motor 42 in the reverse direction in step S16. When the switchback roller 76 starts reverse rotation, the trailing edge of the recording paper in the conveyance direction 55 is sandwiched by the switchback roller pair 56. For this reason, when the switchback roller 76 rotates in the reverse direction and the switching flapper 74 rotates to the re-conveying position, the recording paper held by the switchback roller pair 56 is guided by the switching flapper 74 toward the re-conveying unit 28 described later. Are transported.

  In step S <b> 17, the control unit 96 drives the PF motor 72 so that the re-transport roller 88 rotates. Accordingly, the recording paper conveyed on the re-conveyance guide 84 is conveyed toward the curved guide 58. The recording paper conveyed to the curved guide 58 is conveyed so as to make a U-turn from below to above, and conveyed so that the back surface opposite to the front surface on which the first image is recorded faces the recording head 30. .

  In step S18, the control unit 96 checks whether the registration sensor 51 has detected the leading edge of the recording paper. If NO is determined in step S18, the control unit 96 executes the process of step S17 to further convey the recording paper. On the other hand, when it is determined as YES in step S18, the control unit 96 executes the process of step S19.

  In step S19, the control unit 96 drives the PF motor 72 so that the transport roller 64 and the discharge roller 68 rotate. The leading edge of the recording paper that has passed through the registration sensor 51 reaches the conveyance roller pair 52, and the recording paper is conveyed onto the platen 60 by the conveyance roller pair 52.

  In step S <b> 20, the control unit 96 controls the image recording unit 18 so that the first image is recorded on the recording sheet conveyed to the platen 60 based on the first image data stored in the first storage unit 92. Control the behavior. As a result, the first image is recorded on the other surface of the recording paper P2 on which the first image is partially recorded on one surface.

  In step S21, the control unit 96 causes the PF motor 72 and the paper feed motor to discharge the recording paper on which the first image is recorded to the paper discharge unit 23 by the discharge roller pair 54 and the switchback roller pair 56. 42 is driven. Thereafter, the control unit 96 checks whether or not to record an image on the next recording sheet. When recording an image on the next recording sheet, the control unit 96 executes the process of step S2. When the image is not recorded on the next recording sheet, the control unit 96 ends the process.

  According to the multifunction machine 10 according to an embodiment of the present invention, when the recording paper is double-fed and the first image is recorded across one side of the two double-fed recording papers, the user's If desired, the first image is recorded again on the other side of one of the recording sheets, so that the waste of the recording medium can be eliminated.

  Note that the combination of the control unit 96 and the process of step S9 in the present embodiment is an example of the double feed determination unit of the present invention. A combination of the control unit 96 and the process of step S10 is an example of the image determination unit of the present invention. A combination of the control unit 96 and the process of step S13 is an example of the position determination unit of the present invention. A combination of the second storage unit 97 and the calculation unit 94 is an example of the predetermined amount determination unit of the present invention. Further, the calculation unit 94 serves as both the front and rear end length calculation unit and the deviation length calculation unit of the present invention. Moreover, the combination of the processing of step S9, step S10, and step S15 in the control unit 96 is an example of the first control function of the control unit of the present invention. A combination of the processes of step S9, step S10, step S13, and step S16 in the control unit 96 is an example of the second control function of the control unit of the present invention. The process of step S20 in the control unit 96 is an example of a third control function of the control unit of the present invention.

[Modification]
The multifunction machine 10 only needs to include the printer unit 14. For example, a multifunction machine corresponding to the image recording apparatus of the present invention may not include a scanner unit.

  The printer unit 14 is an inkjet printer having an image recording unit 18 that records an image with ink, but may be any printer that can record an image. For example, the printer unit may be a laser printer having an image recording unit that records an image with toner.

  The recording head 30 of the image recording apparatus 18 is arranged above the conveyance path of the recording paper. However, the present invention is not limited to this, and the recording head 30 may be arranged below the conveyance path.

  The paper feeding unit 20 feeds the recording paper by the paper feeding roller 38 supported by the support arm 40, but may be configured so that the recording paper can be fed. For example, the recording paper is fed by a paper feeding roller fixed to the frame of the printer unit and a paper feeding cassette 22 configured to lift up the recording paper loaded so that the recording paper contacts the paper feeding roller. It may be a paper configuration.

  The paper feed roller 38 is in contact with the upper surface of the stacked recording paper, but may be in contact with the lower surface of the recording paper. In this embodiment, the case where two sheets of recording paper are double-fed is described as an example where the recording paper is double-fed by the paper feed roller 38. However, three or more recording sheets are double-fed. It may be the case.

  The support arm 40 is rotated by its own weight or a spring and insertion / extraction of the paper feed cassette 22, but may be connected to a driving source such as a motor and rotated by transmitting a driving force of the driving source.

  The main transport unit 24 may further include a guide member for guiding the recording paper in addition to the curved guide 58 and the discharge guide 62. The main transport unit 24 guides the recording paper so as to make a U-turn from the lower side to the upper side by the curved guide 58, but the image is recorded on the surface opposite to the surface of the recording paper that the paper feed roller contacts. Any structure may be used as long as it is conveyed.

  The switching unit 26 includes the switchback roller pair 56 and the switching flapper 74. However, the switching unit 26 switches the direction in which the recording paper is conveyed to the direction in which the recording paper is guided to the paper discharge unit or the direction in which the recording paper is guided to the re-conveying unit. If it is. For example, the switching unit may not have the switching flapper 74. The switching unit may have a switching flapper 74 on the downstream side of the switchback roller pair 56 in the transport direction 55.

  The switchback roller pair 56 has a third pinch roller 78 that rotates following the switchback roller 76 to which the driving force is transmitted, but has a third pinch roller 78 below the switchback roller 76. You may do it.

  The paper discharge unit 23 is disposed immediately before the switchback roller pair 56, but may be disposed anywhere as long as the recorded recording paper can be discharged. For example, a guide member for guiding the recording paper to the paper discharge unit may be further provided between the switchback roller pair 56 and the paper discharge unit 23. Further, an intermediate tray that temporarily supports recording paper may be further provided between the switchback roller pair 56 and the paper discharge unit 23.

  The re-conveying unit 28 is disposed from the diagonally lower rear side of the switchback roller pair 56 to the front of the curved guide 58. The re-conveying unit 28 reverses the front and back of the recording paper on which the image is recorded on one side, and again Any configuration that can be conveyed to the recording unit 18 may be used. For example, a guide member may be provided that guides the recording paper conveyed by the reverse rotation of the switchback roller 76 so that the front and back of the recording paper are reversed after passing between the recording head 30 and the platen 60.

  The detection unit 29 includes the registration sensor 51 and the sheet sensor 53, but may include only one of the sensors. The registration sensor 51 and the sheet sensor 53 can detect the presence or absence of recording paper by detecting the thickness of the recording paper or a non-contact sensor such as an ultrasonic sensor, as long as the position of the leading or trailing edge of the recording paper can be detected. It may be a sensor to detect. Further, a sensor that is disposed in the re-conveying unit 28 and detects the presence or absence of recording paper conveyed through the re-conveying unit 28 may be further provided. When the sensor for detecting the presence or absence of the recording paper conveyed through the reconveying unit 28 is provided, the control unit 96 performs a reconveying unit in the arithmetic unit 94 based on the detection result of the sensor during steps S16 to S18. There is newly provided a step for controlling so that the value of the length from the leading edge to the trailing edge of the recording paper conveyed 28 is calculated. Thereby, in steps S15 and S16, it is possible to confirm whether or not the multiple sheets of recording paper that have been multi-fed are separated. If the recording paper has not been separated, that is, if a plurality of recording papers that have been double-fed to the re-conveying unit 28 are conveyed, the control unit 96 uses the re-conveying unit. Based on the detection result of the sensor arranged at 28, the operation of the image recording unit 18 is controlled so that the first image is recorded only on the most subsequent recording sheet among the plural recording sheets conveyed. A new step is provided.

The recording paper length is a value that the recording information has in the information included in the recording operation execution instruction input from the operation panel 12 or an external input device such as a PC. In this case, the leading and trailing edge lengths of the recording medium conveyed immediately before may be used.

  Although the mode selection unit includes the first input button 89 of the operation panel, the internal fixed memory of the control unit 96, and a part of the processing of the control unit 96, the mode selection unit is not limited thereto. The selection of either the single-sided recording mode or the double-sided recording mode is input by the first input button 89, but any input button may be used as long as it is an input button of the multifunction machine 10. The first input button 89 is one input button, but may be a combination of a plurality of input buttons. The mode selection unit may be configured to select a mode in accordance with a mode selection command from an external input device such as a PC instead of the first input button 89.

  The re-recording setting unit includes the second input button 91 included in the operation panel, the internal fixed memory of the control unit 96, and a part of the processing of the control unit 96, but is not limited thereto. Although the re-recording mode setting is input by the first input button 91, any input button may be used as long as the input button of the multifunction device 10 is included. The first input button 91 is one input button, but may be a combination of a plurality of input buttons. Further, the re-recording setting unit may be configured to set the re-recording mode in accordance with an operation signal transmitted from an input operation unit of an external input device such as a PC, instead of the first input button 91 included in the multifunction machine 10. good.

  Although the setting of the re-recording mode by the re-recording setting unit is performed together with the input of the recording operation execution instruction content, the setting is not limited to this as long as it is set by the user. For example, when YES is determined in step S11, the control unit 96 selects whether or not to set the re-recording mode on, for example, the display screen of the operation panel 12 or the display screen of an external input device such as a PC. A message may be displayed to the user so that the user can set the re-recording mode.

  The front and rear end lengths are calculated based on the detection results of the registration sensor 51, but may be calculated based on the detection results of the sheet sensor 53 as long as they can be used for calculation of the deviation length and comparison with each value. When the detection unit 29 further includes other sensors, the leading and trailing edge lengths are calculated based on the detection result of any sensor as long as it is a sensor that detects the presence or absence of recording paper in the main conveyance path 50. Also good.

  The set value “α” used for calculating the deviation length and determining the predetermined amount is set to “2 mm”, but is not limited thereto. The set value “α” is a value that is set in consideration of the conveyance error of the recording paper and the detection error of the sensor. Therefore, the setting value “α” is a value that can reliably detect double feeding, and one of a plurality of multi-feed recording papers. “0” if it is a value that can reliably determine whether or not the first image fits on a sheet and is recorded, or a value that can convey only one of a plurality of multi-fed recording sheets to the re-conveyance unit. Any value including can be used.

  The second storage unit 97 stores one set value “α”, but stores the set value used for calculating the deviation length and the set value used for determining the predetermined amount as different arbitrary values. You may do it. Moreover, although the 1st memory | storage part 92 and the 2nd memory | storage part 97 are provided separately, you may provide in one memory.

  The leading edge margin length is defined as the margin length from the leading edge of the recording paper to be conveyed among the margin lengths included in the first image data, but is not limited thereto. The leading margin length only needs to be able to determine whether or not the first image is recorded across a plurality of sheets of recording paper that have been multi-fed. For example, a sensor for detecting the position of the first image recorded on the recording paper may be further provided, and a margin length value calculated based on the detection result of the sensor may be used.

  The roller radius length R is defined as a value corresponding to the radius of the switchback roller 76, but may be a radius length of a roller disposed below the switchback roller pair 56. If the third pinch roller is disposed below the switchback roller, the roller radius length R is defined as the radius length of the third pinch roller.

  Further, the arithmetic unit 94 uses the roller radius length R for comparison with the deviation length, but any value can be used as long as the two recording sheets can be reliably separated by switching from the forward rotation to the reverse rotation of the switchback roller 76. Instead of the roller radius length R, an arbitrary value may be used.

  The predetermined amount determining unit determines the predetermined amount based on the leading and trailing end lengths and the set value “α”, but may be determined using an arbitrary value set in advance.

  The control unit 96 confirms the recorded information in step S1, but this confirmation is not limited to step S1. Of the information included in the recorded information, the confirmation of the first image can be confirmed in a step before the operation of the image recording unit 18 is controlled so that the first image is recorded by the control unit 96. That's fine. Of the information included in the recording information, the recording paper length may be confirmed in the step before the deviation length is calculated by the calculation unit 94.

  The control unit 96 calculates the misalignment length in step S7. However, the present invention is not limited to step S7, and after the trailing edge of the recording paper is detected by the registration sensor 51, the control unit 96 determines the misalignment length in the calculation unit 94 as “0”. It is only necessary to calculate in the step before confirming the comparison result with "."

  The control unit 96 calculates the leading edge margin length in step S8, but is not limited to step S8, but before the control unit 96 confirms the comparison result between the deviation length and the leading edge margin length in the calculation unit 94. What is necessary is just to calculate in the step.

  In step S11 and step S22, the control unit 96 checks the internal fixed memory of the control unit 96 and determines whether or not the information related to the stored mode is the single-sided recording mode. However, the present invention is not limited to this. For example, when the re-recording mode is set, a message is displayed on the display screen of the operation panel 12 or the display screen of an external input device such as a PC so that the user selects the single-sided recording mode. The single-sided recording mode may be selectable.

  In step S <b> 12, the control unit 96 confirms the internal fixed memory of the control unit 96 and determines whether information indicating that the re-recording mode is set is stored in the internal fixed memory of the control unit 96. However, this determination is not limited to step S12, and may be performed in a step before the switchback roller is rotated forward by a predetermined amount.

  The control unit 96 calculates the predetermined amount in step S14. However, the control unit 96 is not limited to step S14, but before the sheet feeding motor 42 is driven by the control unit 96 so that the switchback roller 76 rotates forward by the predetermined amount. It suffices if it is calculated in this step.

  In step S9, the control unit 96 determines NO when the deviation length is equal to “0”, but may determine YES. In addition, in step S10, the control unit 96 determines NO when the shift length is equal to the leading edge margin length, but may determine YES. In addition, in step S13, the control unit 96 determines NO when the deviation length is equal to the roller radius length R, but may determine YES.

  Further, in step S9, the control unit 96 determines whether or not double feeding has been performed based on a comparison result between a deviation length, which is a value obtained by subtracting the recording paper length from the leading and trailing edge lengths, and “0”. Whether or not the first image is recorded across a plurality of recording sheets is determined based on the comparison result between the shift length and the leading edge margin length, but the determination is not limited to this. For example, the control unit 96 may compare the value obtained by subtracting the leading edge margin length from the leading and trailing edge length with the recording paper length. In this case, when the value obtained by subtracting the leading margin length from the leading and trailing edge length is larger than the recording paper length, the control unit 96 double feeds the recording paper, and the first image has two sheets. It is determined that the recording is performed across the recording paper. On the other hand, when the value obtained by subtracting the leading margin length from the leading and trailing edge lengths is smaller than the recording sheet length, the control unit 96 does not feed the recording sheets or the first image fits on one recording sheet. It is determined that it will be recorded.

10. Multifunction machine (image recording device)
14: Printer unit 18: Image recording unit (recording unit)
20: Paper feeding unit (feeding mechanism)
23 ... Paper discharge unit (discharge unit)
24 ... Main transport section (part of transport mechanism and reversing mechanism)
26 ... switching part (switchback mechanism)
28 ... Re-conveying part (part of reversing mechanism)
30 ... Recording head 32 ... Carriage 34 ... CR motor 38 ... Paper feed roller (feed roller)
40 ... support arm 42 ... feed motor (drive unit)
50 ... main transport path 51 ... registration sensor 53 ... sheet sensor 56 ... pair of switchback rollers 72 ... PF motor 74 ... switching flapper 76 ... switchback roller (first roller)
78 ... Third pinch roller (second roller)
83 ... Re-transport path 89 ... First input button 91 ... Second input button (operation unit)
92 ... 1st memory | storage part (recording medium length memory | storage part)
94: Calculation unit 96: Control unit (control unit)

Claims (6)

In a recording apparatus capable of recording images on both sides of a recording medium by a recording unit,
A feeding mechanism having a feeding roller for feeding the recording medium;
The recording medium is conveyed in a predetermined conveying direction from the feeding mechanism toward the recording unit so that the surface of the recording medium opposite to the surface on which the feeding roller contacts is opposed to the recording unit. A transport mechanism,
The recording medium is sandwiched between a first roller that rotates in the forward and reverse directions and the first roller, and the recording medium is cooperated with the first roller by the forward rotation of the first roller in the predetermined conveying direction. And a second roller for conveying the recording medium in a direction opposite to the predetermined conveying direction in cooperation with the first roller by the reverse rotation of the first roller, and driving the first roller in the forward / reverse rotating direction. A switchback mechanism having a drive unit to
A reversing mechanism for reversing the front and back of the recording medium conveyed by the reverse rotation of the first roller and conveying the recording medium toward the recording unit;
A mode selection unit for selecting one of a single-sided recording mode for recording an image on one side of the recording medium and a double-sided recording mode for recording an image on both sides of the recording medium;
When the single-side recording mode is selected, a plurality of recording media are double-fed from the feeding mechanism and an image is recorded, and an image is formed on one side of the multi-fed recording media. When recording is performed across multiple recording media, the user sets a re-recording mode for recording the same image as the image recorded across the other side of one of the multiple recording media. A re-recording setting unit including an operation unit operable to perform,
A double feed determining unit for determining that the recording medium is double fed from the feeding mechanism;
An image determination unit for determining whether or not an image is recorded across a plurality of recording media that have been multi-fed;
When the trailing edge of the recording medium that is the most rearward in the predetermined transport direction is located at the nipping position between the first roller and the second roller, the other recording medium A position determination unit that determines whether or not a rear end of the medium is positioned at a predetermined value or more downstream from the clamping position;
Among the plurality of double-fed recording media, the leading edge of the recording medium that precedes in the predetermined transport direction reaches the clamping position, and then the trailing edge of the recording medium that follows most reaches the clamping position. And a predetermined amount determining unit that determines a normal rotation amount of the first roller until the rear end of the other recording medium is conveyed more than the predetermined value downstream from the clamping position,
When the double-side recording mode is selected, the multi-feed determining unit determines that the multi-feed has been performed, and the image determining unit determines that an image is recorded across a plurality of recording media. Controls the drive of the drive unit so that the first roller rotates forward until all the rear ends of the multiple fed recording media are conveyed more than the predetermined value downstream from the clamping position. And when the re-recording mode is set by the re-recording setting unit in the one-sided recording mode, the multi-feed determining unit determines that the multi-feed is performed, and the image determining unit Determines that the image is recorded across a plurality of recording media, and when the position determining unit is located at the holding position of the rear end of the most succeeding recording medium, The rear end is on the downstream side of the clamping position. When it is determined that the first roller is positioned at a predetermined value or more, the first roller reaches the predetermined amount after the leading edge of the most preceding recording medium among the plurality of multi-feed recording media reaches the clamping position. A second control function for controlling the drive of the drive unit so as to reversely rotate after normal rotation and the same image as the image recorded across the recording medium conveyed by reversing the front and back by the reversing mechanism are recorded. And a control unit having a third control function for controlling the operation of the recording unit.   The predetermined amount determining unit is configured such that the leading edge of the most preceding recording medium among the plurality of multi-fed sheets reaches the clamping position, and then the trailing edge of the recording medium that follows most reaches the clamping position; and The normal rotation amount of the first roller until the trailing edge of the other recording medium is conveyed downstream from the clamping position by a length corresponding to the radius of the first roller or the second roller. The recording apparatus according to claim 1, wherein the recording apparatus is determined as the predetermined amount. A recording medium length storage unit for storing a length value of one recording medium;
A leading and trailing edge length calculating unit that calculates a length value from the leading edge to the trailing edge in the predetermined conveying direction of one or a plurality of conveyed recording media;
A deviation length calculation unit that calculates a deviation length value based on a value obtained by subtracting a value stored in the recording medium length storage unit from a value calculated by the leading and trailing end length calculation unit;
The image determination unit records a plurality of images when the margin length value from the leading edge of the recording medium to be conveyed until the image appears is smaller than the deviation length value calculated by the deviation length calculation unit. The recording apparatus according to claim 1, wherein the recording apparatus determines that recording is performed across a medium.   When the value of the deviation length is larger than the predetermined value, the position determination unit is configured such that a rear end of the recording medium that is most rearward in the predetermined transport direction among the plurality of multi-fed recording media is the The recording apparatus according to claim 3, wherein when positioned at the clamping position, it is determined that the rear end of the other recording medium is positioned more than the predetermined value on the downstream side of the clamping position.   The recording apparatus according to claim 3, wherein the predetermined amount determination unit determines the predetermined amount based on a value calculated by the leading and trailing end length calculation unit.   2. The apparatus further includes a discharge unit that discharges a recording medium that is transported in the predetermined transport direction by forward rotation of the first roller and whose rear end is transported more than the predetermined value downstream from the clamping position. The recording apparatus according to any one of 5.

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