JP2012076249A - Image recording device - Google Patents

Abstract

A state of a pair of conveyance rollers is detected using an existing sensor that detects the presence or absence of a recording sheet in a conveyance path without providing a new sensor.
A pair of transport rollers and a rotor 67 acting on an optical sensor 68 are provided in the transport path 31. When the recording paper 19 being conveyed on the conveyance path 31 pushes down the rotor 67, the output signal of the optical sensor 68 changes. Based on this change, the control unit 100 detects the presence or absence of the recording paper 19. On the other hand, the pressing roller 35 </ b> B below the transport roller pair 35 that is transported is supported by a roller holder 74. The roller holder 74 can move up and down together with the pressing roller 35B. When the roller holder 74 moves up and down, the rotor 67 rotates and the output signal of the optical sensor 68 changes. Based on this change, the control unit 100 determines the position of the roller holder 74.
[Selection] Figure 8

Description

  The present invention relates to an image recording apparatus having a pair of conveying rollers composed of a driving roller and a driven roller, and particularly to an image recording apparatus configured such that one roller can contact and separate from the other roller.

  In an inkjet image recording apparatus capable of recording an image on a recording sheet, the recording sheet is conveyed from a paper feed cassette toward a recording unit, and the recording unit records an image on the conveyed recording sheet. . A sensor for detecting the conveyance position of the recording paper is provided upstream of the recording unit in the conveyance direction. When it is detected by the sensor that the leading edge of the recording sheet has reached before the pair of conveying rollers, a registration operation is performed to reduce the skew of the recording sheet.

  By the way, when recording an image on a thick recording paper such as a postcard or glossy paper (hereinafter referred to as “thick paper”), when the rear end of the thick paper exits the nip point of the transport roller pair during image recording, the transport roller The pressure contact force of the pair pushes the cardboard in the feeding direction and transports the cardboard excessively. For this reason, in the recorded image recorded on the thick paper, a horizontal white line on which no ink is placed appears. As a means for preventing the generation of the white line, a mechanism for releasing the pressure contact of the conveying roller pair when the rear end of the thick paper leaves the nip point of the conveying roller pair is known.

JP 2009-107179 A

  In a conventional image recording apparatus, when it is determined whether or not the mechanism for releasing the pressure contact between the conveying roller pair is actually operating correctly, it is conceivable that the movement of the movable part of the mechanism is detected by a sensor. However, providing a new sensor to detect the movement of the movable part requires securing the sensor installation space and lead wire routing space, which not only hinders downsizing of the apparatus, This is not preferable because the assembly cost increases and the cost increases.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image recording apparatus capable of detecting the state of a pair of conveying rollers without providing a new sensor.

(1) The present invention provides a guide path capable of guiding a recording medium, a recording unit, a conveyance roller pair, a support member, a moving mechanism, a sensor having a sensing unit, a first detector, and a second detection. The image recording apparatus includes a child, a link mechanism, and a control unit.

  The recording unit records an image on the recording medium conveyed in the first feeding direction along the guide route. The conveying roller pair is provided on the upstream side in the first feeding direction from the recording unit. This pair of conveying rollers is composed of a driving roller and a driven roller that are arranged to face each other with the guide path interposed therebetween. The support member is configured to pivotally support the driven roller and to be movable between a first position where the driven roller contacts the driving roller and a second position which is separated from the driving roller. The moving mechanism receives the driving force supplied from the driving source and moves the support member from the first position to the second position. The first detector is configured to be rotatable between a first posture in which the detected portion is disposed at a position detectable by the sensing portion and a second posture in which the detected portion is retracted from the detectable position. ing. The second detector is provided on the upstream side in the first feed direction with respect to the pair of transport rollers so as to be rotatable in conjunction with the first detector. The second detector has a third posture that intersects the guide route when at least the first detector is in the first posture. The biasing member applies an elastic biasing force to the second detector so as to maintain the third posture. The link mechanism rotates the second detector from the third posture against the elastic biasing force in conjunction with the support member moving from the first position to the second position by the moving mechanism. Let

  The control unit controls image recording on the recording medium conveyed in the first feeding direction. The control unit includes first determination means, movement control means, and second determination means. The first determination means determines the rear end position of the recording medium in the guide route based on the output signal of the sensor. The movement control means drives and controls the drive source on the condition that the rear end position is determined by the first determination means, and moves the support member from the first position to the second position by the movement mechanism. Let The second determination means determines the position of the support member based on the output signal of the sensor on the condition that the drive control for the drive source is performed by the movement control means.

  In the process in which the recording medium is transported in the first feeding direction and reaches the front of the pair of transport rollers, the second detector is pressed against the elastic force of the urging member in the third posture as pushed by the recording medium. To the downstream side in the first feed direction. The first detector rotates in conjunction with the rotation of the second detector, and the detected part moves away from the position where the sensor can be detected. At this time, the first detector changes from the first posture to the second posture, and the output signal of the sensor changes. The control unit determines the position of the leading end of the recording medium in the guide route based on this change. When the recording medium is further conveyed and the rear end thereof passes through the second detector, the second detector returns to the third posture by the elastic biasing force of the biasing member. At this time, the first detector returns from the second posture to the first posture, and the output signal of the sensor changes. The first determination means of the control unit determines the rear end position of the recording medium in the guide route based on this change.

  After the rear end position of the recording medium is determined, the movement control means of the control unit starts drive control for the drive source. Thereby, a driving force is supplied from the driving source to the moving mechanism, and the moving mechanism moves the support member from the first position to the second position. When the support member moves to the second position, the second detector is rotated from the third posture against the elastic urging force by the link mechanism. At this time, in conjunction with the rotation of the second detector, the first detector also rotates to assume the second posture, and the detected portion is separated from the position detectable by the sensing portion. Thereby, the output signal of the sensor changes. The second determination unit of the control unit determines whether the support member is in the first position or the second position based on the output signal of the sensor when the movement control unit performs drive control on the drive source.

  As described above, according to the present invention, the position of the support member and the rear end position of the recording medium can be determined by one sensor without providing a new sensor. Thereby, it is possible to prevent an increase in the cost of the device, and to prevent an increase in wiring in the device and a complicated layout of the internal mechanism.

(2) In addition, it is preferable that the first determination unit determines whether the rear end of the recording medium in the guide path is at a nip point of the conveyance roller pair based on an output signal of the sensor. . In this case, the movement control control means drives and controls the drive source on the condition that the rear end of the recording medium is determined to be at the nip point by the first determination means, and the support member is controlled by the movement mechanism. Is moved from the first position to the second position.

(3) The control unit includes storage means for storing thickness information of a recording medium on which an image is recorded. In this case, the movement control means drives and controls the drive source when the thickness information stored in the storage means is equal to or greater than a predetermined value, and moves the support member from the first position to the second position by the movement mechanism. It is preferable to move it.

  Thereby, the movement control by the movement control means is performed only when an image is recorded on a recording medium in which a white line is likely to occur in a recorded image such as cardboard.

  According to the present invention, the moving position of the support member can be detected using the sensor for detecting the position of the recording medium in the guide route. That is, a plurality of detection targets can be detected by one sensor. For this reason, it is not necessary to provide a plurality of sensors for each of a plurality of detection targets, and it is possible to prevent an increase in cost, an increase in the number of parts, and an increase in the size of the apparatus caused by adding a new sensor.

1 is a perspective view illustrating an external appearance of a multifunction machine 10. 2 is a schematic cross-sectional view schematically showing a configuration of a printer unit 15. FIG. 3 is a perspective view illustrating a configuration of a transfer device 30. FIG. 7 is a perspective view illustrating a configuration of a cam moving mechanism 88. FIG. 3 is a perspective view showing a configuration of a detection mechanism 52. FIG. FIG. 5 is a cross-sectional view for explaining operations of a roller holder 74, a rotor 67, and a detector 54. 2 is a block diagram illustrating a configuration of a control unit 100. FIG. 3 is a flowchart illustrating a procedure of image recording processing executed by a CPU 101. FIG. 6 is a cross-sectional view showing a configuration of a modification of rotation restriction mechanism 80.

  Hereinafter, an MFP 10 according to an embodiment of the present invention will be described with reference to the drawings as appropriate. In the following description, the vertical direction 7 of the multifunction device 10 is defined with reference to the state in which the multifunction device 10 is installed (the state shown in FIG. 1), and the side on which the operation panel 16 is provided is in front. A front-rear direction 8 is defined as the side (front), and a left-right direction 9 is defined when the multifunction machine 10 is viewed from the front (front).

[Outline of MFP 10]
As shown in FIG. 1, the multifunction machine 10 includes a printer housing 11, a scanner housing 12 provided on the upper side of the printer housing 11, and a document cover 13 provided on the upper side of the scanner housing 12. And an operation panel 16 having an LCD 16A. The document cover 13 is supported by the scanner housing 12 so as to be openable and closable. The document cover 13 is opened and closed to sandwich the document with the scanner housing 12. The image of the document is scanned and captured by a scanner (not shown) such as a flat bed scanner housed in the scanner housing 12. The scanner housing 12 in which the scanner is accommodated is supported by the printer housing 11 so that it can be opened and closed.

  The printer housing 11 includes an accommodation space 18 in which the paper feed cassette 14 is accommodated in the lower part. The accommodation space 18 is provided from the opening 17 formed in the front surface of the printer housing 11 to the rear back part. The paper feed cassette 14 is supported in the housing space 18 so that it can be inserted and removed in the front-rear direction 8. A plurality of recording sheets are held in the sheet feeding cassette 14. The paper feed cassette 14 can hold not only recording paper called so-called plain paper but also thick recording paper (thick paper) such as postcards and glossy paper.

  Control of the printer unit 15 and the above-described scanner is performed by a control unit 100 (see FIG. 7) described later. The control unit 100 drives the printer unit 15 based on a signal input from the operation panel 16 of FIG. 1 or an external device such as a personal computer, and records an image on a recording medium. Further, as will be described later, the control unit 100 also performs processing for detecting the presence / absence of a recording sheet being conveyed and a conveyance position, and detecting movement of a roller holder 74 described later.

[Printer unit 15]
The printer unit 15 records an image on a transported recording medium. As shown in FIG. 2, the printer unit 15 mainly includes a paper feed cassette 14 that holds the recording paper 19 and a transport device 30 that transports the recording paper 19. And a recording unit 20 (an example of the recording unit of the present invention) that records an image on the recording paper 19.

[Recording unit 20]
The recording unit 20 includes a recording head 21 disposed above the rear portion of the paper feed cassette 14, a carriage 23 that holds the recording head 21, and a rail (with the carriage 23 that supports the recording head 21 so as to be slidable in the left-right direction 9. And a drive unit including a carriage motor 111 (see FIG. 7) and a drive transmission mechanism that transmits the driving force to the carriage 23.

[Recording head 21]
The recording head 21 includes a nozzle having an ejection port. When the nozzle is deformed by a piezoelectric element or the like, an ink droplet is ejected from the ejection port toward the lower platen 22. The recording head 21 is reciprocated in the left-right direction 9 by receiving the driving force of the carriage motor 111 (see FIG. 7). As will be described later, the recording paper 19 is ejected from the recording head 21 that reciprocates in the left-right direction 9 in the process of being conveyed forward on the platen 22, thereby An image can be recorded on almost the entire surface.

[Conveying device 30]
As shown in FIG. 3, the transport device 30 includes a paper feed roller 41 (see FIG. 2), a transport roller pair 35 (an example of the transport roller pair of the present invention), a recording medium in the transport path 31, and a later-described recording medium. It has the detection mechanism 52 which detects the position of the roller holder 74, the cam drive mechanism 88, and the frame 25 which supports these. In FIG. 3, the paper feed roller 41 is not shown.

[Frame 25]
A pair of frames 25 are provided on the rear side of the printer unit 15 so as to face each other with a predetermined interval in the left-right direction 9. The frame 25 is formed of a metal plate and is fixed to a base frame 39 provided on the lower side thereof.

[Feeding roller 41]
As shown in FIG. 2, the paper feed roller 41 feeds the recording paper 19 placed on the paper feed cassette 14 to the transport path 31. The paper feed roller 41 is disposed above the rear portion of the paper feed cassette 14 and is rotatably supported at the tip of an arm 43 that rotates about a support shaft 42. The support shaft 42 is supported by the frame 25 and the like so as to be rotatable about its central axis. When the driving force of the sheet feeding motor 112 (an example of the driving source of the present invention, see FIG. 7) is transmitted to the support shaft 42, it is supplied by the driving force transmitted from the support shaft 42 via the plurality of transmission gears 44. The paper roller 41 rotates. The recording paper 19 is sent out to the conveyance path 31 by rotating the paper supply roller 41 in contact with the recording paper 19. Note that a switching gear 114 (see FIG. 7) is provided on the output side of the paper feeding motor 112. By switching the driving transmission of the switching gear 114, the driving force of the paper feeding motor 112 is fed. It is transmitted to either the roller 41 or the cam drive mechanism 88.

[Conveyance path 31]
As shown in FIG. 2, a conveyance path 31 (an example of the guide path of the present invention) is formed in the printer unit 15. The conveyance path 31 includes a first conveyance path 32 having an arc cross section in which one end is located on the rear end portion of the paper feed cassette 14 and the other end is located behind the conveyance roller pair 35, and the platen 22 from the conveyance roller pair 35 to the platen 22. A linear second conveyance path 33 that reaches the front of the discharge roller pair 36 through the recording head 21 is formed. The first transport path 32 is formed of an inner guide member 32A and an outer guide member 32B that are each formed in an arc shape and are opposed to each other in the radial direction. The recording paper 19 delivered from the paper feed cassette 14 is guided by the first conveyance path 32 and the second conveyance path 33 to reach the recording unit 20, and then passes through the second conveyance path 33 to the paper discharge unit 14A. Discharged.

  In the second conveyance path 33, the conveyance path 31 is sandwiched on the rear side of the recording unit 20, in other words, on the upstream side in the direction in which the recording paper 19 is conveyed during recording (corresponding to the first feeding direction of the present invention). A pair of conveying rollers 35 is provided. A pair of discharge rollers 36 is provided in front of the recording unit 20 so as to sandwich the second conveyance path 33.

[Conveying roller pair 35]
As shown in FIG. 3, the conveyance roller pair 35 is composed of an upper conveyance roller 35A (an example of a driving roller of the present invention) and a lower pressing roller 35B (an example of a driven roller of the present invention). . The upper transport roller 35A is supported by the frame 25 so as to be rotatable about its central axis, and is rotated by the driving force of the transport motor 113 (see FIG. 7). The lower pressing roller 35B is supported by a roller holder 74 described later so as to be rotatable about its central axis.

[Discharge roller pair 36]
As shown in FIG. 2, the discharge roller pair 36 includes an upper pinch roller 36A and a lower discharge roller 36B. The upper pinch roller 36A is supported by the frame 25 and the like so as to be rotatable about its central axis.

[Roller holder 74]
As shown in FIGS. 3 and 4, the roller holder 74 (an example of the support member of the present invention) is provided slightly behind the conveying roller pair 35. The roller holder 74 is configured as a separate member from the platen 22. The roller holder 74 has a shape that is long in the left-right direction 9 by connecting four blocks in the left-right direction 9. A pressing roller 35B is rotatably supported at the front upper end of each block. In the present embodiment, the roller holder 74 supports eight pressing rollers 35 </ b> B arranged in a straight line along the left-right direction 9. A plurality of pressing rollers 35 </ b> B are rotatably supported on the front upper end portion of the roller holder 74. In the present embodiment, the roller holder 74 supports eight pressing rollers 35 </ b> B arranged in a straight line along the left-right direction 9. A plurality of support shafts 76 (see FIG. 5) are provided at the upper rear end of the roller holder 74. The support shaft 76 is supported by a bearing groove (not shown) provided in the subframe 26 described later. With this configuration, the roller holder 74 can rotate around the support shaft 76. More specifically, the roller holder 74 includes a first position (corresponding to the first position of the present invention) where the pressing roller 35B contacts the upper conveying roller 35A, and a first position where the pressing roller 35B is spaced downward from the conveying roller 35A. It can be rotated around a support shaft 76 between two positions (corresponding to the second position of the present invention).

  As shown in FIG. 4, a subframe 26 formed of a metal plate is provided below the roller holder 74. Both ends of the subframe 26 are fixed to the frame 25. A coil spring 78 is provided between the roller holder 74 and the subframe 26. In FIG. 4, the conveyance roller 35A is not shown. The coil spring 78 is provided at a position near the pressing roller 35 </ b> B so that the expansion / contraction direction is the vertical direction 7. Specifically, the upper end of the coil spring 78 is accommodated in a spring holder 78A provided on the back surface (lower surface) of the upper wall of the roller holder 74, and the lower end of the coil spring 78 is attached to the subframe 26. The coil spring 78 is provided between the roller holder 74 and the sub-frame 26 in a contracted state so as to apply a set biasing force to the transport roller 35A. As a result, an upward biasing force for the coil spring 78 to extend is applied to the roller holder 74, and the roller holder 74 maintains the first position. The upward biasing force of the coil spring 78 acts on the pressing roller 35B via the roller holder 74, and the pressing roller 35B is pressed against the conveying roller 35A with the biasing force. When the front end portion of the roller holder 74 is lowered downward against the urging force by a cam drive mechanism 88 described later, the roller holder 74 moves from the first position to the second position, and the pressing roller 35B is also transported. Move downward from 35A.

  Further, a stopper 74 </ b> A that protrudes downward from the rear end portion is provided near the center of the rear end portion of the roller holder 74. The stopper 74 </ b> A is provided behind the support shaft 76 that is the rotation center of the roller holder 74. Therefore, in FIG. 6, when the roller holder 74 is rotated counterclockwise (counterclockwise direction), the stopper 74A is moved upward, and when the roller holder 74 is rotated clockwise (clockwise direction), the stopper 74A is moved downward. To do. The stopper 74 </ b> A of the roller holder 74 is engaged with a later-described restricting member 81 and plays a role of restricting the rotation of the restricting member 81. The link mechanism of the present invention is realized by the stopper 74A and a regulating member 81 described later.

[Detection mechanism 52]
The detection mechanism 52 is for realizing a function of detecting the recording sheet 19 conveyed toward the recording unit 20 and a function of detecting the state of the roller holder 74. As shown in FIG. 3, the detection mechanism 52 is provided behind the pair of transport rollers 35 (upstream in the paper transport direction during recording). The detection mechanism 52 covers a rear portion of the roller holder 74 and accommodates each component of the detection mechanism 52, and an optical sensor 68 (an example of the sensor of the present invention) provided outside the left end portion of the case 69. Have The case 69 has a shape that is long in the left-right direction 9, and the case 69 is fixed to the subframe 26 by engaging a plurality of claws (not shown) provided at the front end of the case 69 with the subframe 26. As shown in FIG. 5, a rotating shaft 57 extending from near the center in the left-right direction 9 to the outside of the left end is rotatably supported in the case 69. An arm-shaped rotor 67 (an example of the second detector of the present invention) is fixed to the rotating shaft 57. A slit is formed in the central portion of the case 69 in the left-right direction 9, and the rotor 67 protrudes upward from the rotary shaft 57 and is exposed from the inside of the case 69 to the outside through the slit (see FIG. 3). . A detector 54 (an example of the first detector of the present invention) is provided at the left end of the rotating shaft 57. The detector 54 protrudes in the same direction as the rotor 67. The rotor 67 and the detector 54 are fixed to the rotation shaft 57. Therefore, when a rotational force is applied to the rotor 67, the detector 54 rotates in the same direction in conjunction with the rotor 67.

[Rotation restriction mechanism 80]
As shown in FIG. 5, a torsion coil spring 58 (hereinafter abbreviated as “spring 58”) is attached to the rotor 67. The spring 58 applies a biasing force F <b> 1 to the rotor 67 so that the rotor 67 is rotated backward from the posture shown in FIG. 5. A rotation restricting mechanism 80 that restricts the rotation of the rotor 67 by the urging force F <b> 1 is attached to the right end portion of the rotation shaft 57. The rotation restricting mechanism 80 includes a joint 83 connected to the right end portion of the rotation shaft 57, a restricting member 81 fixed to the joint 83, and a torsion coil spring 82 (hereinafter referred to as “spring 82”) attached to the restricting member 81. ). The joint 83 is connected to the right end of the rotary shaft 57 so as to be coaxially rotatable with the rotary shaft 57. The joint 83 is configured to allow the rotor 67 to try to rotate forward from the posture shown in FIG. 5 with respect to the restricting member 81 and to restrict trying to rotate backward. . Note that the biasing member of the present invention is realized by the spring 58 and the spring 82.

  The restricting member 81 has a protrusion 84 that protrudes in a direction perpendicular to the rotation shaft 57. The protrusion 84 protrudes rearward from the restricting member 81. The spring 82 applies a biasing force F <b> 2 that is greater than that of the spring 58 to the regulating member 81. Specifically, the spring 82 applies an urging force F <b> 2 (> F <b> 1) to the restricting member 81 so that the protrusion 84 tries to rotate upward from the posture shown in FIG. 5. That is, the urging force F2 acts in the direction opposite to the direction of the urging force F1. The urging force F <b> 2 is sufficiently smaller than the urging force of the coil spring 78. The above-described stopper 74 </ b> A provided at the rear end of the roller holder 74 is in contact with the upper surface of the protrusion 84. For this reason, the force applied to each member is balanced, and the rotor 67 protrudes upward from the rotation shaft 57 in the posture shown in FIG. 5 and FIG. Hold the intersecting posture. On the other hand, when the front end portion of the roller holder 74 is moved from the first position (position in FIG. 6A) to the second position (position in FIG. 6D) by the cam drive mechanism 88 described later, the rotation of the roller holder 74 is performed. The stopper 74A located rearward of the support shaft 76 that is the center moves upward. As a result, the regulating member 81 receives the biasing force F2 and rotates in the biasing direction. In conjunction with this rotation operation, the rotor 67 receives the rotational force from the joint 83 and tilts forward, and the detector 54 retracts from the sensing portion of the sensor 68 (see FIG. 6D). Note that the amount of rotation of the rotor 67 at this time is very small, and the rotor 67 maintains a state of intersecting the second conveyance path 33.

[Optical sensor 68]
The optical sensor 68 is a transmissive photo interrupter in which a light emitting element and a light receiving element are arranged to face each other. In the optical sensor 68, the light receiving element receives the light emitted from the light emitting element, and outputs an electrical signal (sensor signal) corresponding to the amount of received light. A light path (light path) from the light emitting element to the light receiving element is the sensing unit 68 </ b> A of the optical sensor 68. The optical sensor 68 is attached to the frame 25 so that the sensing unit 68 </ b> A is disposed in the rotation range of the detector 54. In the present embodiment, when the roller holder 74 is in the first position and the recording paper 19 is not present in the transport path 31, the tip 54A of the detector 54 (corresponding to the detected part of the present invention) serves as the sensing part 68A. It has entered and blocked the optical path (see FIGS. 5 and 6A). At this time, a low level sensor signal is output from the optical sensor 68. The controller 100 determines that the tip 54A has entered the sensing unit 68A when the sensor signal is at the LOW level. Note that the posture of the detector 54 (the posture shown in FIGS. 5 and 6A) when the distal end portion 54A enters the sensing portion 68A corresponds to the first posture of the present invention. When the recording paper 19 is guided along the conveyance path 31 and pushes down the rotor 67, the detector 54 is rotated in conjunction with the rotation, and the leading end 54A is retracted from the optical path of the sensing unit 68A. At this time, a high level sensor signal is output from the optical sensor 68. When the sensor signal changes from LOW to HIGH, the control unit 100 determines that the distal end portion 54A has retreated from the optical path of the sensing unit 68A. Note that the posture of the detector 54 when the distal end portion 54A is retracted from the sensing portion 68A corresponds to the second posture of the present invention.

[Cam drive mechanism 88]
The cam driving mechanism 88 is a mechanism that receives the driving force from the paper feeding motor 112 (see FIG. 7) and moves the roller holder 74 between the first position and the second position described above. As shown in FIG. 4, the cam drive mechanism 88 includes a bearing portion 89, a cam shaft 90, two cams 91, a shaft guide 75, and a link member 92. The bearing portion 89 is integrally provided at the front end portion of the roller holder 74. The bearing portion 89 is an annular member in which a ring larger than the outer diameter of the cam shaft 90 is formed. The shaft guides 75 are provided at both ends of the sub-frame 26 provided on the lower side of the roller holder 74 and are erected upward from the upper surface of the sub-frame 26. Each shaft guide 75 supports the cam shaft 90 so as to be rotatable and supports the cam shaft 90 so as to be movable in the vertical direction 7, and has a vertically long guide groove 75 </ b> A and a hook shape from the upper end of the shaft guide 75 to the left side. And a cam receiving portion 75B protruding in the direction. Both ends of the cam shaft 90 are inserted into the guide grooves 75 </ b> A of the shaft guide 75 of the sub-frame 26 while being passed through the ring of the bearing portion 89. Thereby, the cam shaft 90 is supported so as to be movable in the vertical direction 7 along the guide groove 75A. A cam 91 is fixed to the cam shaft 90. The cam 91 is fixed to the cam shaft 90 so as to be positioned below the cam receiving portion 75B of the shaft guide 75. The link member 92 is a portion that receives a driving force from the paper feeding motor 112 and is fixed to the right end of the cam shaft 90.

  When the link member 92 is in the posture shown in FIG. 4, the cam 91 is in a free state. At this time, the cam shaft 90 is supported by the lower portion of the bearing portion 89. The roller holder 74 is held at a first position where the pressing roller 35B is pressed against the transport roller 35A by an upward biasing force of the spring 78. On the other hand, when the driving force of the paper feeding motor 112 (see FIG. 7) is input to the link member 92 and the cam shaft 90 rotates, the cam 91 also rotates. When the outer edge portion of the cam 91 comes into contact with the cam receiving portion 75B by the rotation of the cam 91, the cam shaft 90 is pressed downward, and the cam shaft 90 moves downward. Further, when the cam shaft 90 moves downward, the front end portion of the roller holder 74 together with the bearing portion 89 is pulled by the cam shaft 90 against the biasing force of the spring 78, and the second position below the first position. Move to. Thereby, the pressing roller 35B is separated from the conveying roller 35A. The moving mechanism of the present invention is realized by the cam driving mechanism 88.

  Next, the configuration of the control unit 100 (an example of the control unit of the present invention) will be described with reference to FIG. The control unit 100 implements the first determination unit, the movement control unit, and the second determination unit of the present invention.

  As shown in FIG. 7, the control unit 100 mainly includes a CPU 101, a ROM 102 (an example of a storage unit of the present invention), and a RAM 103. The CPU 101, the ROM 102, and the RAM 103 are connected to each other via a bus line. The control unit 100 is connected to the operation panel 16, the carriage motor 111, the paper feed motor 112, the transport motor 113, the encoder 116, and the optical sensor 68 via the input / output port 105.

  The CPU 101 controls each function of the MFP 10 and controls each unit connected to the input / output port 105 according to data values and programs stored in the ROM 102 and RAM 103. The ROM 102 is a non-rewritable memory that stores a control program executed by the multifunction machine 10. A program for executing an image recording process described later shown in the flowchart of FIG. 8 and information on the thickness of a recording sheet used for the image recording process (hereinafter referred to as “thickness information”) are stored in the ROM 102. The RAM 103 is a rewritable volatile memory, and temporarily stores various data when each operation of the multifunction machine 10 is performed, and stores threshold data used in the determination process in the image recording process.

  Hereinafter, the procedure of the image recording process shown in the flowchart of FIG. 8 executed by the CPU 101 will be described with reference to FIG. 6, and the operation of each component of the multifunction machine 10 will be described. 6A is a cross-sectional view showing a state when the recording paper 19 is not present in the conveyance path 31, and FIG. 6B is a cross-sectional view showing a state where the recording paper 19 pushes down the rotor 67. ) Is a cross-sectional view showing a state when the rear end of the recording paper 19 has passed through the rotor 67, and (D) is a cross-sectional view showing a state in which the roller holder 74 has moved to the second position. 6A to 6D, the left side is a cross-sectional view showing the operation of the detector 54, and the right side is a cross-sectional view showing the operation of the roller holder 74.

  In this image recording process, when an image recording instruction is input, first, the CPU 101 obtains the thickness information of the recording sheet 19 on which an image is recorded based on various information included in the data stream input together with the image recording instruction. Obtain (S11). For example, when a data stream including print condition data and image data is input from an external personal computer connected to the multifunction peripheral 10 via a printer driver, the CPU 101 analyzes the print condition data included in the data stream. Then, the paper type set as the paper on which the image is recorded is acquired. The ROM 102 stores in advance thickness information corresponding to each of a plurality of paper types, and the CPU 101 reads out from the ROM 102 thickness information corresponding to the paper type acquired from the printing condition data.

  In the next step S12, the CPU 101 compares the thickness information acquired in step S11 with a threshold value stored in advance in the ROM 102 or RAM 103, and determines whether the thickness information is equal to or greater than the threshold value. The threshold value is a threshold value related to the thickness of the recording paper. When image recording is performed on a recording paper (thick paper) having a certain thickness or more, the recording paper is excessively conveyed when the rear end passes through the nip point of the conveying roller pair 35, and a horizontal line of white lines is formed on the recording surface. The phenomenon that appears in. The minimum thickness of the recording paper that can cause such a phenomenon is set as the threshold value.

  If it is determined in step S12 that the thickness information is less than the threshold value, a normal image recording process (S13) is performed in which the recording paper 19 is conveyed while the conveying roller pair 35 is always in pressure contact during image recording. Is called. On the other hand, when it determines with the said thickness information being more than the said threshold value, the process after step S14 is performed. Note that the description of the normal image recording process executed in step S13 is omitted.

  When the recording paper 19 is sent out to the transport path 31 by the paper feed roller 41, the CPU 101 starts processing for detecting the leading end position of the recording paper 19 in the transport path 31 based on the level of the output signal of the optical sensor 68. When the leading edge of the recording paper 19 pushes down the rotor 67 while the recording paper 19 is being conveyed, the detector 54 rotates and retracts forward from the sensing portion 68A of the optical sensor 68 (see FIG. 6B). At this time, the output signal of the optical sensor 68 changes from LOW to HIGH. The CPU 101 detects that the leading edge of the recording paper 19 has passed through the rotor 67 based on the change at this time (S14). That is, the CPU 101 detects the presence of the recording paper 19 in the transport path 31 and the leading end position.

  Subsequently, when the leading edge of the recording paper 19 reaches the image recording start position, image recording is started by the recording unit 20 (S15). During image recording, intermittent conveyance is repeated that repeats a process of conveying the recording paper 19 by a predetermined amount and a process of stopping the conveyance. While the conveyance of the recording paper 19 is stopped, the carriage 23 reciprocates and ink is discharged from the recording head 21. By ejecting the droplets, an image (band image) having a predetermined width is recorded on the recording paper 19. An image is recorded on the recording paper 19 by repeating the image recording with the predetermined width.

  When the image recording is started, the CPU 101 starts processing for detecting the rear end position of the recording paper 19 in the conveyance path 31 based on the level of the output signal of the optical sensor 68. When the trailing edge of the recording paper 19 passes through the rotor 67 during conveyance of the recording paper 19, the rotor 67 returns to the original position as shown in FIG. 6C, and the detector 54 is interlocked with this operation. Rotates to enter the sensing portion 68A of the optical sensor 68 again (see FIG. 6C). At this time, the output signal of the optical sensor 68 changes from HIGH to LOW. Based on the change at this time, the CPU 101 detects that the rear end of the recording paper 19 has passed through the rotor 67 (S16). That is, the CPU 101 detects the rear end position of the recording paper 19. In addition, the 1st determination means of this invention is implement | achieved by performing the process of step S16.

  When the trailing edge of the recording paper 19 is detected, the CPU 101 subsequently determines whether or not the trailing edge of the recording paper 19 has reached the nip point of the conveying roller pair 35, more specifically, the trailing edge of the recording paper 19 is conveyed. It is determined whether or not a predetermined position slightly before the nip point of the roller pair 35 has been reached (S17). Specifically, the conveyance amount of the recording paper 19 after the trailing edge is detected is calculated based on a signal from the encoder 116 attached to the conveyance roller 35A or the conveyance motor 113, and the calculated value and the rotor 67 are calculated. The distance from the nip point to the nip point is compared, and when the calculated value coincides with the distance to the predetermined position before the nip point, the rear end of the recording paper 19 is a predetermined distance before the nip point of the conveying roller pair 35. It is determined that the position has been reached.

  Subsequently, on the condition that the rear end position of the recording paper 19 has reached the nip point of the transport roller pair 35, the CPU 101 performs recording in a state where the rear end of the recording paper 19 is sandwiched between the transport roller pair. While the sheet 19 is stopped, the drive transmission path of the sheet feeding motor 112 is switched from the path transmitting to the sheet feeding roller 41 to the path transmitting to the cam drive mechanism 88 (S18), and then the sheet feeding motor. 112 is driven by a predetermined amount of rotation (S19). Specifically, the switching method is performed, for example, by changing the position of the switching lever provided in the switching gear 114 using the carriage 23 or other movable members. As a result, the driving force of the paper feeding motor 112 is transmitted to the roller holder 74 via the cam driving mechanism 88, and the roller holder 74 moves from the first position to the second position. Thereby, the pressing roller 35B is separated from the conveying roller 35A. The predetermined rotation amount is the rotation amount until the cam 91 of the cam drive mechanism 88 rotates and reaches the cam receiving portion 75B of the shaft guide 75. Thereafter, intermittent conveyance and image recording of the recording paper 19 are executed again. In addition, the movement control means of this invention is implement | achieved by performing the process of step S18 and S19.

  Subsequently, the CPU 101 determines whether or not the roller holder 74 is in the second position based on the output signal of the optical sensor 68 (S20). When the roller holder 74 moves to the second position, the rotor 67 is tilted forward as described above, and the detector 54 is retracted forward from the sensing unit 68A (see FIG. 6D). At this time, the level of the output signal of the optical sensor 68 changes from LOW to HIGH again. Such a change in signal level is the same as when the leading edge of the recording paper 19 pushes down the rotor 67. However, in step S20, the CPU 101 determines the position of the roller holder 74 based on the change in the output signal, on condition that control other than the sheet feeding purpose is performed on the sheet feeding motor 112 in step S19 described above. judge. In other words, when the CPU 101 satisfies two conditions, that is, the control other than the sheet feeding control is executed on the sheet feeding motor 112 and the output signal of the optical sensor 68 changes from LOW to HIGH. It is determined that the roller holder 74 is in the second position. In addition, the 2nd determination means of this invention is implement | achieved by performing the process of step S20.

  If it is determined in step S20 that the roller holder 74 is not in the second position, the processes in steps S19 and S20 are repeated again. If this repetitive process is executed a predetermined number of times and it is still determined that the roller holder 74 is not in the second position, an error display indicating an abnormality of the roller holder 74 is output to the LCD 16A or an externally connected personal computer. . In this case, the image recording operation is interrupted due to the abnormality of the roller holder 74. Note that the image recording operation may be continued without interruption.

  If it is determined that the roller holder 74 is in the second position, the CPU 101 drives the paper feeding motor 112 by a predetermined amount of rotation on the condition that it is determined that image recording has been completed in the next step S21. The roller holder 74 is returned from the second position to the first position (S22).

  Subsequently, the CPU 101 determines whether or not the roller holder 74 is in the first position based on the output signal of the optical sensor 68 (S23). When the roller holder 74 returns to the first position, the rotor 67 returns to the original posture shown in FIG. 6A as described above, and the detector 54 enters the sensing unit 68A again (FIG. 6A). reference). At this time, the level of the output signal of the optical sensor 68 changes from HIGH to LOW again. Such a change in signal level is the same as when the trailing edge of the recording paper 19 passes through the rotor 67. However, in step S23, the CPU 101 sets the position of the roller holder 74 based on the change in the output signal, on condition that control other than the sheet feeding purpose is performed on the sheet feeding motor 112 in step S19 described above. judge. If it is determined in step S23 that the roller holder 74 is not in the first position, the processes in steps S22 and S23 are repeated. If this repetitive process is executed a predetermined number of times and it is still determined that the roller holder 74 is not in the first position, an error display indicating an abnormality of the roller holder 74 is output to the LCD 16A or an externally connected personal computer. .

  If it is determined in step S23 that the roller holder 74 is in the first position, the drive transmission path of the paper feeding motor 112 is switched from the path transmitting to the cam drive mechanism 88 to the path transmitting to the paper feeding roller 41. (S24) The next image recording is prepared.

[Effect of the present invention]
As described above, in the image recording process in the multifunction machine 10, the leading edge position and the trailing edge position of the recording sheet 19 sent out from the sheet feeding cassette 14 are detected based on the change in the level of the output signal from the optical sensor 68. In addition, based on the change in the level of the output signal from the same optical sensor 68, it can be determined whether the position of the roller holder 74 is the first position or the second position. For this reason, since it is not necessary to provide an optical sensor for each of a plurality of detection targets, it is possible to prevent an increase in cost, an increase in the number of parts, and an increase in the size of the apparatus caused by adding a new sensor.

  In this embodiment, an example in which the optical sensor 68 is used as an example of the sensor has been described. However, a magnetic sensor, a contact-type sensor, or the like can be used instead of the optical sensor 68. In the above-described embodiment, the example in which the paper feeding motor 112 is also used as the driving source of the roller holder 74 has been described. However, the single driving of a solenoid, a motor, or the like without using the paper feeding motor 112 is also described. The present invention is also applicable to a configuration in which the roller holder 74 is moved using a power source without switching drive transmission.

  In the above-described embodiment, the link mechanism realized by the stopper 74A and the regulating member 81 has been described. However, as shown in FIG. 9, a stopper 74B is adopted instead of the stopper 74A, and the protrusion 84 is a protrusion. The restriction member 81 replaced with 85 may be adopted, and the stopper 74B and the restriction member 81 may be used. The stopper 74B protrudes downward from the rear end portion of the roller holder 74. The stopper 74 </ b> B is provided in front of the support shaft 76 that is the rotation center of the roller holder 74. Accordingly, in FIG. 9, when the roller holder 74 is rotated counterclockwise (counterclockwise), the stopper 74B is moved downward, and when the roller holder 74 is rotated clockwise (rightwardly rotated), the stopper 74B is moved upward. To do. The protrusion 85 protrudes vertically from the restriction member 81 forward. A stopper 74B is in contact with the upper surface of the protrusion 85. However, in this case, the urging force F1 applied to the rotor 67 is set larger than the urging force F2 applied to the regulating member 81, and the rotation is performed so that the posture shown in FIG. A stopper is provided to prevent the child 67 from rotating backward (clockwise direction in FIG. 9). Also, the joint 83 restricts the restricting member 81 from rotating from the posture shown in FIG. 9A to the counterclockwise rotation direction with respect to the rotor 67 and tries to rotate in the clockwise rotation direction. It is configured to allow

  Because of such a configuration, when the rotor 67 is held in the posture shown in FIG. 9A, that is, in a posture that protrudes upward from the rotation shaft 57 and intersects the second conveyance path 33. When the front end portion of the roller holder 74 is moved from the first position (position of FIG. 9A) to the second position (position of FIG. 9B) by the cam drive mechanism 88, the support that is the rotation center of the roller holder 74 is supported. The stopper 74A located in front of the shaft 76 moves downward. As a result, the protrusion 85 is pushed downward by the stopper 74B and moves, and the restricting member 81 rotates counterclockwise. In conjunction with this turning operation, the rotor 67 is tilted forward by receiving the rotational force from the joint 83, and the detector 54 is retracted forward from the sensing portion of the sensor 68 (see FIG. 9B). The present invention can also be applied to such a link mechanism.

10. Multifunction machine (image recording device)
15: Printer unit 19: Recording paper (recording medium)
20: Recording unit 30 ... Conveying device 31 ... Conveying path (guide path)
35... Transport roller pair 54... Detector (first detector)
58 ... Torsion coil spring 67 ... Rotor (second detector)
68 ... Optical sensor (sensor)
74: Roller holder (supporting member)
80 ... rotation restricting mechanism 81 ... regulating member 82 ... torsion coil spring 88 ... cam drive mechanism (moving mechanism)
100: Control unit

Claims (3)

A guide route capable of guiding the recording medium;
A recording unit that records an image on a recording medium conveyed in the first feeding direction along the guide path;
A pair of conveying rollers including a driving roller and a driven roller, which are provided upstream of the recording unit in the first feeding direction and arranged to face each other across the guide path;
A support member that pivotally supports the driven roller and is movable between a first position where the driven roller contacts the drive roller and a second position spaced apart from the drive roller;
A moving mechanism that receives the driving force supplied from the driving source and moves the support member from the first position to the second position;
A sensor having a sensing unit;
A first detector that is rotatable between a first posture in which the detected portion is disposed at a position detectable by the sensing portion and a second posture in which the detected portion is retracted from the detectable position;
It is provided upstream of the pair of transport rollers in the first feed direction so as to be able to rotate in conjunction with the first detector, and crosses the guide path when at least the first detector is in the first posture. A second detector in a third posture
An urging member for applying an elastic urging force to the second detector so as to maintain the third posture;
A link mechanism for rotating the second detector from the third posture against the elastic biasing force in conjunction with the movement of the support member from the first position to the second position by the moving mechanism; ,
A control unit for controlling image recording on the recording medium conveyed in the first feeding direction,
The control unit
First determination means for determining a rear end position of the recording medium in the guide route based on an output signal of the sensor;
Movement control means for driving and controlling the drive source on the condition that the rear end position is determined by the first determination means and moving the support member from the first position to the second position by the movement mechanism; ,
An image recording apparatus comprising: a second determination unit that determines a position of the support member based on an output signal of the sensor on the condition that the movement control unit performs drive control on the drive source. The first determination means determines whether the trailing edge of the recording medium in the guide path is at the nip point of the pair of conveying rollers based on the output signal of the sensor,
The movement control control means controls driving of the drive source on the condition that the rear end of the recording medium is determined to be at the nip point by the first determination means, and moves the support member by the movement mechanism. The image recording apparatus according to claim 1, wherein the image recording apparatus is moved from one position to the second position. The control unit includes storage means for storing thickness information of a recording medium on which an image is recorded,
The movement control means drives and controls the drive source when the thickness information stored in the storage means is equal to or greater than a predetermined value, and moves the support member from the first position to the second position by the movement mechanism. The image recording apparatus according to claim 1.

Images