JP2008132628A - Conveyance mechanism, recorder equipped with it, and control method of conveyance mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveyance mechanism which prevents a medium from floating from a reference plane for processing and can reduce variation of a medium conveyance load, and to provide a recorder equipped with the same, and a control method of the conveyance mechanism. <P>SOLUTION: The conveyance mechanism 11 of the inkjet printer 1 has a pair of conveyance rollers comprised of a paper feed roller 41 and a following roller 42 which hold a paper P therebetween and convey from the supply side onto a platen surface 91a, a following auxiliary roller 42a which presses the paper P passed through a pair of the conveyance rollers towards on the platen surface 91a, a second conveyance part which holds the paper P passed through on the platen surface 91a and conveys it to the downstream side, and a processing gap adjustment mechanism 51 which adjusts a gap PG between the platen surface 91a and a printing processing mechanism 43. After the completion of locating the head of the paper P, printing processing is carried out after the following auxiliary roller 42a is released upward. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a conveyance mechanism that conveys a medium to a processing unit that performs information processing on a sheet-like medium on a processing reference surface, a recording apparatus including the medium, and a method for controlling the conveyance mechanism.

An example of a device that conveys a sheet-shaped medium along a predetermined conveyance path and performs information processing on a medium conveyed on a processing reference plane in the middle of the conveyance path is a personal computer or the like. A connected printer (recording device) can be mentioned.
In such a printer, in a device case forming an outline, a sheet feeding unit that stacks and stores sheets of media, and a sheet that is fed out one by one from the sheet feeding unit and conveyed along a predetermined conveyance path A mechanism, a print head that performs image printing processing such as characters and figures on the surface of the paper that has been transported to the platen surface (processing reference surface) set in the middle of the transport path, and a predetermined movement to the print head Various operating devices such as a carriage for applying force are incorporated.

In recent printers, there are various types of front feed / discharge types in which both the paper feed unit and the printed paper discharge unit are arranged on the front side of the device in order to make the device compact and save space. It has been proposed (see, for example, Patent Document 1).
In such a front feed / discharge type printer, a paper cassette in which sheets are stacked and fed for paper feeding is arranged at the lower part of the front of the apparatus, and a paper discharge tray for discharging the printed paper is provided in the paper cassette. A U-shaped transport path that is disposed above and connects between the paper cassette and the paper discharge tray is constructed in the apparatus case, and the platen surface is located in the middle of the linear transport path that constitutes the U-shaped transport path. Is set, the print head is arranged above the platen surface.

  In the U-shaped conveyance path of the front feed / discharge type printer, a paper feed roller and a driven roller for holding the sheet and conveying it to the platen surface provided on the downstream side of the conveyance path, An intermediate roller and an assist roller for holding the paper fed into the transport path and transporting it to the paper feed roller and the driven roller separated by a predetermined distance on the downstream side of the transport path, or transport onto the platen surface A print head that performs a printing process on the sheet that has been printed, and a discharge roller and a guide roller that discharge the sheet printed by the print head to a discharge tray at the exit of the conveyance path are disposed.

  In addition, in an inkjet printer, the paper is folded or curled before it is fed, or there is an influence of wrinkles and curls generated on the paper due to the adhesion of ink droplets. A paper jam is likely to occur in the vicinity of the conveying means for nipping and conveying the paper that has passed through the print processing section downstream.

  Therefore, as a recording apparatus for suppressing the occurrence of paper jam in these parts, an inkjet recording apparatus provided with an inkjet recording means (at least a head mounting portion) and a platen that supports a recording medium corresponding to the head mounting portion in a recording area. In this case, there is known a paper presser plate for holding a sheet fed onto the platen surface by a sheet feeding roller from above and holding it on the platen surface (see, for example, Patent Document 2).

Japanese Patent No. 3520469 Japanese Patent No. 3507485

  By the way, in the recording apparatus described in the above-mentioned Patent Document 2, the paper conveyed on the platen surface is pressed by the paper pressing plate to prevent the paper from being lifted from the platen surface. The load applied to the paper from the paper presser plate changes due to the difference. For this reason, the load from the paper pressing plate becomes a factor that fluctuates the paper conveyance load, leading to a decrease in print processing accuracy. In particular, this tendency tends to be manifested when the trailing edge of the paper is removed from the paper supply roller and the paper is conveyed by the paper discharge roller. Also, when the trailing edge of the paper passes through the paper pressing plate, the load that has been applied to the paper from the paper pressing plate until then suddenly disappears, so that the paper conveyance load fluctuates.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a transport mechanism that can prevent the medium from floating from the processing reference surface and can reduce fluctuations in the medium transport load, a recording apparatus including the transport mechanism, and a transport mechanism control method. It is to provide.

  A transport mechanism according to the present invention that can solve the above-described problems is a transport mechanism that transports the medium to a processing unit that performs information processing on a sheet-like medium on a processing reference surface. A pair of conveyance rollers for nipping the medium and conveying the medium from the supply side onto the reference surface for processing; and a pressing portion for pressing the medium that has passed through the pair of conveyance rollers toward the reference surface for processing, The pressing portion is capable of moving in a direction away from the processing reference surface independently of the pair of transport rollers.

  According to the transport mechanism configured as described above, when the sheet-like medium is sandwiched by the pair of transport rollers and transported toward the processing reference surface of the processing unit, the medium is placed on the processing reference surface by the pressing unit. Therefore, it is possible to prevent the medium from floating in the processing unit. Then, the load applied to the medium from the pressing unit can be reduced by moving the pressing unit in a timely manner in a direction away from the processing reference surface independently of the conveyance roller pair, and the fluctuation of the medium conveyance load is reduced. be able to. Thereby, it is possible to suppress a decrease in accuracy of information processing performed on the medium on the processing reference surface.

  In the transport mechanism of the present invention, it is preferable that the amount of movement of the pressing portion can be adjusted.

  According to the transport mechanism configured as described above, it is possible to set an appropriate amount of movement of the pressing portion corresponding to a difference in the type (quality, thickness, etc.) of the medium. For this reason, it is possible to reduce the difference in the medium conveyance load due to the difference in the type of medium.

  The transport mechanism according to the present invention further includes a processing gap adjustment mechanism that adjusts a gap between the processing reference surface and the processing unit, and the pressing unit moves by power transmission from the processing gap adjustment mechanism. It is preferable.

  According to the transport mechanism configured as described above, since the pressing portion is moved by the power of the processing gap adjusting mechanism, it is not necessary to provide a dedicated drive source for moving the pressing portion, and the cost of the apparatus can be reduced. Can be planned. Moreover, the movement operation of the pressing portion can be performed together with the gap adjustment operation.

  In the transport mechanism of the present invention, the timing at which the pressing portion moves is set after the front end of the medium has passed the pressing portion and before the rear end of the medium has passed the transport roller pair. It is preferable that

  According to the transport mechanism configured as described above, the holding unit is held at a predetermined position until at least the front end of the medium passes through the pressing unit, and the medium conveyed on the processing reference surface is lifted. Make sure to prevent it. Then, when the trailing edge of the medium passes through the pair of conveyance rollers, the variation in the conveyance load tends to increase. Therefore, the variation in the conveyance load can be reduced by moving the pressing portion in the direction away from the processing reference plane until then. .

  In addition, a recording apparatus according to the present invention that can solve the above-described problems includes the transport mechanism according to the present invention, and the processing unit includes a print head that performs a printing process on the medium.

  The recording apparatus configured as described above prevents the medium from being lifted from the processing reference surface when the print process is performed by the print head, thereby preventing the medium in the transport mechanism from being clogged, and also causing a change in the medium transport load. The print processing accuracy can be kept good.

  In addition, the control method of the transport mechanism according to the present invention that can solve the above-described problem is a transport that transports the medium to a processing unit that performs information processing on the sheet-like medium on the processing reference surface. In the control method of the mechanism, the transport mechanism includes a transport roller pair that sandwiches the medium and transports the medium from the supply side onto the processing reference surface, and a medium that has passed through the transport roller pair. A pressing portion that presses upward, and after the front end of the medium has passed through the pressing portion, until the rear end of the medium has passed the pair of conveying rollers, the pressing portion is It is characterized in that it is moved in a direction away from the processing reference surface independently of the pair of conveying rollers.

  According to the control method of the transport mechanism configured as described above, when the sheet-shaped medium is sandwiched by the pair of transport rollers and transported toward the processing reference surface of the processing unit, at least the front end of the medium has the pressing unit. The holding portion is held at a predetermined position until it passes, and the medium is pressed toward the processing reference surface by the holding portion, so that it is possible to prevent the medium from floating in the processing portion. Then, the load applied to the medium from the pressing portion is reduced by moving the pressing portion in a direction away from the processing reference surface independently of the conveying roller pair until the rear end of the medium passes the conveying roller pair. And fluctuations in the medium transport load can be reduced. Thereby, it is possible to suppress a decrease in accuracy of information processing performed on the medium on the processing reference surface.

  In the transport mechanism control method of the present invention, it is preferable that the amount of movement of the pressing portion is adjusted according to the type of the medium to be transported.

  According to the control method of the transport mechanism configured as described above, the medium is transported by adjusting the amount of movement of the appropriate pressing portion corresponding to the difference in the type (quality, thickness, etc.) of the medium, and by the difference in the type of the medium. The difference in load can be reduced.

  In the transport mechanism control method of the present invention, the transport mechanism includes a processing gap adjustment mechanism that adjusts a gap between the processing reference surface and the processing unit, and is adapted to the type of the medium to be transported. It is preferable that the movement amount of the pressing portion is adjusted together with the gap adjusting operation by the processing gap adjusting mechanism.

  According to the control method of the transport mechanism configured as described above, when performing the gap adjustment operation according to the thickness of the medium, the appropriate amount for the medium can be efficiently set by adjusting the amount of movement of the pressing portion at the same time. be able to.

  Further, in the control method of the transport mechanism according to the present invention, immediately after the medium is cued to the processing unit by the transport roller pair, the pressing unit is controlled independently of the transport roller pair. It is preferable to move in a direction away from the reference plane.

  According to the control method of the transport mechanism configured as described above, until the end of the medium cueing operation, the presser unit reliably presses the medium up and performs a good cueing operation. By moving the pressing unit before the processing operation by the processing unit is performed, it is possible to maintain good processing accuracy without changing the transport load after the processing operation is started.

Hereinafter, an example of embodiments of a transport mechanism, a recording apparatus including the transport mechanism, and a control method of the transport mechanism according to the present invention will be described with reference to the drawings.
In the present embodiment, the ink jet printer 1 shown in FIG. 1 will be described as an example of a recording apparatus having a transport mechanism. However, the transport mechanism according to the present invention may be, for example, a copier, a scanner, a facsimile, in addition to a printer. It is also applicable to banknote change machines and the like.

  1 is an external perspective view of an ink jet printer according to an embodiment of the present invention, FIGS. 2 and 3 are external perspective views of a state in which a paper discharge tray and an upper case are removed from the ink jet printer shown in FIG. 6 is a side cross-sectional view for explaining a paper transport path in the ink jet printer shown in FIG. 1, FIGS. 7 to 10 are side cross-sectional views of main parts of a paper transport path in the ink jet printer shown in FIG. 1, and FIG. FIG. 12 is a control block diagram of the ink jet printer shown in FIG. 1. FIG. 12 is a plan view showing a part of the mechanism for moving the pressing portion.

An ink jet printer 1 according to the present embodiment is a front feed / discharge type printer, and has a sheet-like shape in the center of the front surface of an apparatus case 4 composed of an upper case 2 and a lower case 3 as shown in FIG. A substantially box-shaped paper cassette 5 in which paper P, which is a medium of the above, is stacked and accommodated, is detachably inserted.
Further, a paper discharge tray 6 for receiving the printed paper is provided so as to cover the open top portion of the paper cassette 5.

  Further, a display unit 7 such as an indicator and an operation unit 8 such as a power switch are disposed on the left and right sides of the front surface of the device case 4. The black ink cartridge mounting portion and the color ink cartridge mounting portion disposed on the left and right sides of the front surface of the apparatus case 4 are covered with a black ink cover 9 and a color ink cover 10 that can be freely opened and closed, respectively.

  As shown in FIGS. 2 and 3, the paper sheet P that is fed out from the paper cassette 5 one by one by a pickup roller (paper feed roller) 21 of a paper feed unit 22 to be described later is conveyed in a U-shape inside the apparatus case 4. A transport mechanism 11 that transports along a path (transport path), a carriage 13 that is reciprocally movable in a direction perpendicular to the transport direction of the paper P in the middle of the U-shaped transport path by the transport mechanism 11, A print head 44 that is mounted on the carriage 13 and discharges micro droplets of recording ink onto the paper P to perform printing processing (information processing), and ink tanks 15 and 16 that store recording ink supplied to the print head 44. And a control unit (see FIG. 12) that controls the conveyance speed of the paper P by the conveyance mechanism 11, the movement speed of the carriage 13, the ink ejection operation of the print head 44, and the like. There.

2 and 3, the carriage 13 is supported by a pair of carriage shafts 53, 53 extending in the paper width direction so as to be movable in the paper width direction, and is driven by a carriage motor 14. It is fixed to 54 and is reciprocated in the paper width direction according to the travel of the timing belt 54.
The inkjet printer 1 controls the ink ejection operation from the print head 44 mounted on the carriage 13 with the transport direction of the paper P as the sub-scanning direction and the moving direction of the carriage 13 as the main scanning direction. Image recording (printing processing) of characters and graphics is performed.

In the case of the inkjet printer 1 of the present embodiment, the U-shaped transport path through which the paper P is transported by the transport mechanism 11 is an arc-shaped transport path for transporting the paper P fed from the paper cassette 5 as shown in FIG. A and a linear conveyance path B that connects the arcuate conveyance path A to the paper discharge tray 6.
Further, a guide part 34 which is a part of a mechanism constituting the arcuate conveyance path A of the U-shaped conveyance path is assembled to the rear opening / closing cover 17 shown in FIG. The rear opening / closing cover 17 that can open and close the portion 34 constitutes a conveyance path opening / closing mechanism that exposes a part of the paper P jammed in the arcuate conveyance path A due to a paper jam.

The transport mechanism 11 further includes an auto sheet feeder (ASF) unit, a first transport unit, and a second transport unit.
The auto sheet feeder is provided in the arcuate conveyance path A, and a paper feeding unit 22 that feeds a plurality of sheets P stacked in the paper cassette 5 one by one to the entrance of the arcuate conveyance path A at the rear of the apparatus. An intermediate roller 31 and an assist roller 33 for conveying the paper P fed out by the paper feeding unit 22 while being sandwiched between a paper feed roller 41 and a driven roller 42 separated by a predetermined distance on the downstream side, and on the outer periphery of the intermediate roller 31 And a guide portion 34 that regulates the conveyance direction of the sheet P fed along the arc to reach the exit of the arcuate conveyance path A.

  The intermediate roller 31 as a driving roller sandwiches and conveys the paper P by sandwiching the paper P with the assist roller 33 as a driven roller. A retard roller 32 is provided on the upstream side of the assist roller 33 to prevent a plurality of sheets P from being fed out to the arcuate conveyance path A.

The first transport unit transports the paper P that has been transported from the paper P supply side (arc-shaped transport path A) by a pair of transport rollers including a paper feed roller 41 and a driven roller 42 provided on the linear transport path B. Is a paper feeding section that conveys the paper onto a platen 91 having a platen surface (processing reference surface) 91a disposed downstream thereof (see FIG. 7). As shown in FIG. 7, the first conveyance unit is provided with a driven auxiliary roller 42 a in the vicinity of the downstream side of the driven roller 42, and the driven auxiliary roller 42 a includes the paper feed roller 41 and the driven roller 42. Functions as a pressing portion that presses the sheet P that has passed through the platen toward the platen surface 91a.
In the first transport unit of the present embodiment, the driven roller 42 presses and urges the upper surface of the paper P against the paper feed roller 41 as a driving roller that contacts the lower surface of the paper P, thereby sandwiching the paper P. While being conveyed, the driven auxiliary roller 42a prevents the paper P from being lifted.

  Further, inside the apparatus case 4, a print processing mechanism (processing unit) 43 including a print head 44 that prints images such as characters and graphics on the paper P conveyed on the platen surface 91 a of the platen 91. Is incorporated. The paper P that has undergone the printing process by the print processing mechanism 43 is conveyed while being sandwiched between a paper discharge roller 48a that is a driving roller and a guide roller 48b that is a driven roller that constitutes the second conveyance unit, and is conveyed in a U-shape. The paper is discharged to a paper discharge tray 6 at the route exit.

  As shown in FIG. 4, the paper feed unit 22 is configured such that a rear end of a paper feed lever 25 having a pickup roller 21 for feeding at the front end can be rotated in the vertical direction in the figure by a support pin 24. The sheet feeding unit 22 can bring the pickup roller 21 into contact with the uppermost sheet P in the sheet cassette 5 by swinging the sheet feeding lever 25 downward.

In the paper feeding unit 22, when the ink jet printer 1 is stopped, the paper feeding lever 25 is maintained substantially horizontal as shown in FIG. 4, and the pickup roller 21 is kept away from the paper P on the paper cassette 5. .
At the time of paper feeding, the pickup roller 21 is pressed against the uppermost paper P in the paper cassette 5, as shown in FIG. As the roller 21 rotates, the paper P in the paper cassette 5 comes into contact with the inclined friction pad 23, and is fed out to the arcuate conveyance path A one by one while being separated by the frictional force and the stiffness of the paper P.

At this time, the retard roller 32 applies a force in a direction to push the paper P back to the paper cassette 5, and is sandwiched between the intermediate rollers 31 to separate the paper P one by one and to provide a downstream arcuate conveyance path. Separately conveyed to A.
When the paper supply is completed and printing is started by the print processing mechanism 43, the paper supply lever 25 is returned to the original horizontal state as shown in FIG.

An auxiliary guide member 35 is provided on the upper side of the guide unit 34 together with an assist roller 33 for feeding the conveyed paper P toward the linear transport path B side.
The auxiliary guide member 35 is rotatably supported at the rear end side with respect to the guide portion 34 and is swingable at the front end side.
As shown in FIG. 6, the auxiliary guide member 35 presses the sheet P conveyed from the arcuate conveyance path A to the linear conveyance path B by its own weight from the upper side, and holds the sheet P in the linear conveyance path B. To the front side of the ink jet printer 1.

  The paper feed roller 41 and the driven roller 42 constituting the first transport unit are provided a predetermined distance away from the exit end of the arcuate transport path A (the downstream end of the guide unit 34) on the front side of the apparatus. As shown in FIG. 6, the paper P sent out from the arcuate conveyance path A to the linear conveyance path B is nipped and conveyed under the print processing mechanism 43 which is the printing position. By controlling the rotational driving amount of the paper feed roller 41, it is possible to position the paper P with respect to the print processing mechanism 43 (such as a cueing operation).

As shown in FIG. 4, the print head 44 of the print processing mechanism 43 has a discharge nozzle 46 that discharges ink droplets toward the paper P. On the rear side of the inkjet printer 1 with respect to the discharge nozzle 46, A PW sensor 47 that detects the paper P and detects its width is provided.
The PW sensor 47 detects the presence or absence of the paper P by detecting the reflected light of the light irradiated toward the paper P, and detects the width of the paper P by the movement of the carriage 13.
In the ink jet printer 1 of the present embodiment, paper detection sensors that detect the presence or absence of the paper P are installed at a plurality of appropriate locations on the transport path. For example, in the present embodiment, a sheet detection sensor 45 provided at a position where the sheet P conveyed from the arcuate conveyance path A to the linear conveyance path B can be detected is provided. The paper detection sensor may be a transmissive sensor.

  Further, the transport mechanism 11 of the present embodiment adjusts the gap between the platen surface 91a and the print head 44 for the printing process on the paper P having a different thickness and the direct printing process on the CD-R surface. A processing gap adjustment mechanism (APG: Auto Platen Gap mechanism) 51 is provided.

  As shown in FIGS. 7 to 10, the processing gap adjusting mechanism 51 is rotatably provided at each end of a pair of carriage shafts 53 and 53 that support the carriage 13 so as to be movable in the width direction of the paper P. A housing on the side of the device case 4 so that the transmission gear 55 and the cam 57 formed integrally with the transmission gear 55 with a cam surface 57b raised on a part of the outer periphery of the cylindrical portion 57a are in contact with the outer periphery of the cam 57. A ring-shaped cam receiver 59 supported by the body, a gap adjusting wheel train 61 (see FIG. 2) for inputting rotational force to the transmission gear 55, and a gap adjusting motor for rotationally driving the gap adjusting wheel train 61 63.

  In the processing gap adjusting mechanism 51 configured as described above, the rotational driving force output from the gap adjusting motor 63 is input to the transmission gear 55 via the gap adjusting wheel train 61, and the transmission gear 55 is predetermined in the direction of the arrow X in FIG. When the angle rotates, as shown in FIG. 8, the cam surface 57 b of the cam 57 rides on the cam receiver 59 to move each carriage shaft 53 upward. Due to the upward movement of the carriage shaft 53, the print head 44 of the print processing mechanism 43 ascends integrally with the carriage 13, and the gap PG between the platen 91 and the platen surface 91a is expanded.

The cylindrical portion 57a of the cam 57 adjusts the gap PG between the platen 91 and the print head 44 to the minimum by contact with the cam receiver 59, and has a thickness among the paper types to be printed. Used when printing the thinnest paper P.
As shown in FIG. 9, the cam surface 57b of the cam 57 includes an inclined portion 58a in which the amount of protrusion from the rotation center gradually changes, and an arc portion 58b that maintains the maximum amount of protrusion of the inclined portion 58a. The inclined portion 58a is used for gap adjustment when printing on paper P having different thicknesses such as postcards or CD-ROM, and the arc portion 58b is used between the platen 91 and the print head 44 when a paper jam occurs. It is used when the gap PG is adjusted to the maximum (predetermined interval).

In the ink jet printer 1 of the present embodiment, the paper feed roller 41 is connected to a shaft end of a wheel train (gear train) that transmits rotation by the rotation of the paper feed shaft 71, as shown in FIG. And is driven by the rotation of the paper feed shaft 71.
A large-diameter belt wheel 72 is fixed to the outer periphery of the paper feed shaft 71. Further, a small-diameter belt wheel 74 is provided on the output shaft of a paper feed motor (PF motor) 73 provided at the lower part on the left side of the ink jet printer 1, and the belt wheel 74 and the large-diameter belt wheel are provided. A timing belt 75 is wound around the belt 72. That is, the paper feed roller 41 is rotationally driven by the paper feed motor 73.

On the other hand, the driven roller 42 paired with the paper feed roller 41 is rotatably provided at the tip (swing end) of a swing arm 77 supported swingably by a support shaft 76 as shown in FIG. In general, the size and arrangement of the swing arm 77 are set so that the driven roller 42 is kept in press contact with the paper feed roller 41.
In the case of this embodiment, as shown in FIG. 8, when the gap adjustment between the print head 44 and the platen 91 is performed by driving the gap adjustment motor 63, the tip of the swing arm 77 is interlocked. A first release mechanism 78 is provided that swings and displaces upward to retract the driven roller 42 away from the paper feed roller 41.

The first release mechanism 78 receives the rotation of the gap adjusting motor 63, and the oscillating arm when the rotation amount of the rotation shaft 81 reaches a predetermined angle on the outer periphery of the rotation shaft 81 rotating in the direction of the arrow Y1 in FIG. In this configuration, a first release protrusion 82 is provided to push down the rear end of 77 and move the tip of the swing arm 77 upward.
Therefore, when the first release protrusion 82 pushes down the rear end of the swing arm 77 by the rotation of the rotation shaft 81, the tip of the swing arm 77 swings upward as shown by the arrow Z in FIG. The driven roller 42 is separated (released) from the paper feed roller 41.

  The rotation shaft 81 of the first release mechanism 78 transmits power through the transmission gear 55 of the processing gap adjustment mechanism 51 and a gear (not shown). The transmission gear 55 rotates by a predetermined angle in the direction of arrow X in FIG. When the cam surface 57 b of the cam 57 rides on the cam receiver 59, the rotation shaft 81 is set to rotate by a predetermined angle so that the first release protrusion 82 pushes down the rear end of the swing arm 77. As described above, the first release mechanism 78 is operated in conjunction with the operation in which the processing gap adjustment mechanism 51 widens the gap PG to the maximum extent.

  Further, in the inkjet printer 1 of the present embodiment, the driven auxiliary roller 42a that is a pressing portion moves in a direction away from the platen surface 91a independently of the pair of conveying rollers including the paper feed roller 41 and the driven roller 42 (that is, The platen surface 91a can be released).

  As shown in FIGS. 11 and 4 to 6, the driven auxiliary roller 42 a is supported by the auxiliary arm 77 a and is disposed at a position slightly downstream of the driven roller 42. The auxiliary arm 77 a is rotatably supported on the side portion of the swing arm 77 by a shaft 76 a disposed in the vicinity of the support shaft 76 of the swing arm 77. A second release protrusion 82 a is formed on the outer periphery of the rotating shaft 81 with a phase different from that of the first release protrusion 82 for swinging the swing arm 77.

  The second release protrusion 82 a is disposed so as to contact the auxiliary arm 77 a at a smaller rotation angle than the rotation angle of the rotation shaft 81 for the first release protrusion 82 to contact the swing arm 77. For example, on the cam surface 57b, the rotation amount of the rotary shaft 81 when the inclined portion 58a used for gap adjustment when printing on paper P of different thickness such as postcard or CD-ROM contacts the cam receiver 59 The rotation amount of the rotary shaft 81 when the second release protrusion 82a contacts the auxiliary arm 77a is preferably set to be substantially equal.

  As shown in FIG. 6, when the rotation amount of the rotary shaft 81 reaches a predetermined angle (smaller than a predetermined angle in the first release protrusion 82), the rear end of the auxiliary arm 77a is pushed down by the second release protrusion 82a. The tip of the auxiliary arm 77a is moved upward, and the driven auxiliary roller 42a is moved upward. Thus, the driven auxiliary roller 42a moves in conjunction with the operation in which the processing gap adjustment mechanism 51 finely adjusts the gap PG.

When the driven auxiliary roller 42a moves upward, the force for pressing the paper P becomes weak and the load applied to the paper P is reduced. By moving the driven auxiliary roller 42a in a timely manner, it is possible to suppress fluctuations in the conveyance load of the paper P.
Further, the amount of upward movement of the driven auxiliary roller 42a can be finely adjusted by the amount by which the auxiliary arm 77a is pushed down, that is, the rotation angle of the rotary shaft 81.

  In the discharge rollers 48 a provided in two rows along the conveyance direction of the second conveyance portion, one row is provided on the rotation shaft 90 (see FIG. 3), and the other row is transmitted by rotation of the rotation shaft 90. It is provided on a shaft that rotates in the same direction as the rotation shaft 90 via a train wheel. The rotary shaft 90 is rotationally driven by gears 79 and 80 that transmit the rotation of the paper feed shaft 71 as shown in FIG. That is, the paper discharge roller 48a is driven to rotate by the paper feed motor 73 in the same manner as the paper feed roller 41 of the first transport unit.

  The guide roller 48b constituting the driven roller of the second transport unit is a roller for pressing the upper surface of the paper P that has passed between the platen 91 and the print head 44 to a transport reference position having a predetermined height. It is supported at a predetermined position by the support member 92. The guide rollers 48b are so-called serrated rollers provided with protrusions at regular intervals in the circumferential direction, and are arranged in three rows at predetermined intervals along the conveying direction, and are rotatably supported by the support member 92. Further, the guide roller 48b is supported by a coil spring-like shaft, and is appropriately elastically displaced in a direction orthogonal to the rotation axis when the paper P is pressed so that the position and the contact pressure with respect to the paper P are adjusted appropriately. It has become. Of the three rows of guide rollers 48b, two rows are arranged corresponding to the paper discharge rollers 48a arranged in two rows, and the paper P is sandwiched and conveyed in cooperation with these paper discharge rollers 48a. To do.

Further, in the inkjet printer 1 of the present embodiment, a paper feed motor 73 that also serves as a drive source for the paper feed roller 41 is input to the paper feed shaft 71 via the belt wheel 74, the timing belt 75, and the large-diameter belt wheel 72. The rotational driving force thus transmitted is transmitted to the intermediate roller 31 and the paper discharge roller 48 a via a train wheel (not shown) connected to the paper feed shaft 71.
However, in the case of the intermediate roller 31, a one-way clutch mechanism 84 that enables power transmission only when the paper feed motor 73 rotates forward is interposed between the intermediate roller 31 and the train wheel connected to the paper feed shaft 71.

  As shown in FIGS. 7 and 8, the one-way clutch mechanism 84 of this embodiment includes a relay gear 85 that is rotatably supported by the pivot 83 and to which the rotational force of the paper feed roller 41 is transmitted, and the relay gear 85. A frame 87 having an intermediate portion rotatably supported by a pivot 86 disposed between the intermediate roller 31 and the intermediate roller 31, and is rotatably supported on one end side of the frame 87 via a torque limiter. The planetary gear 88 that can mesh with the provided gear 31a and the planetary gear 88 that is arranged on the pivot 86 so that the central axis coincides with the direction of the rotational force that is received from the relay gear 85 are transferred to the intermediate roller 31. And a transmission gear 89 capable of transmitting a rotational force while swinging in a direction to be engaged with and disengaged from the gear 31a.

  When the paper feed roller 41 is rotationally driven in the direction in which the paper P is normally conveyed (that is, when the paper feed motor 73 is rotating forward), the transmission gear 89 meshes the planetary gear 88 with the gear 31a of the intermediate roller 31. The rotational force is transmitted to the gear 31a of the intermediate roller 31 via the planetary gear 88 while maintaining the meshing state by swinging and biasing in the direction of rotation (the direction opposite to the arrow D shown in FIG. 10).

  On the other hand, when the paper feed roller 41 is driven in reverse by the reverse drive of the paper feed motor 73 as shown by the arrow E in FIGS. 7 and 10, the transmission gear 89 moves the planetary gear 88 from the gear 31 a of the intermediate roller 31. Since the meshing state is released by swinging and energizing in the direction of detachment (the direction of arrow D shown in FIG. 10), the planetary gear 88 simply rotates idle and cannot transmit the rotational force to the intermediate roller 31 and the gear 31a. Thereby, power transmission to the intermediate roller 31 via the one-way clutch mechanism 84 is interrupted.

In order to return the one-way clutch mechanism 84 to the original state in which power can be transmitted to the intermediate roller 31, the paper feed motor 73 is rotated forward, and the planetary gear 88 is transferred to the gear 31 a of the intermediate roller 31 via the transmission gear 89. What is necessary is just to carry out rocking | biasing biasing in the direction to mesh.
The swinging range of the planetary gear 88 is defined by engaging the engaging portion provided on the other end side of the frame 87 with the pivot 83.

  Next, control of the inkjet printer 1 of the present embodiment will be described with reference to FIGS. 12 and 13. The ink jet printer 1 of the present embodiment is configured to reduce fluctuations in the paper transport load by moving the driven auxiliary roller 42a upward when executing the printing process by the printing processing mechanism 43. Hereinafter, the control of the inkjet printer 1 will be described while focusing on the movement operation of the driven auxiliary roller 42a.

FIG. 12 is a block diagram showing a control mechanism for controlling the ink jet printer 1 of the present embodiment.
The ink jet printer 1 according to the present embodiment is configured around a control unit 101. The control unit 101 is physically configured by a processor such as a CPU, a volatile memory having a rewritable storage area such as a RAM, a rewritable nonvolatile memory such as a flash ROM, and the like, and firmware stored in the flash ROM By executing the above, each part of the inkjet printer 1 is controlled, and printing processing is executed while communicating with the host computer 200 installed outside via the communication interface 121.

  For example, the inkjet printer 1 drives a carriage motor 14 that controls the position of the carriage by driving the carriage motor 14 and a gap adjustment motor 63 as a driver circuit that controls drive parts. A gap adjusting motor driving unit 103 that adjusts the gap PG between the printing head 44 and a paper feeding motor driving unit 104 that drives the paper feeding motor 73 to rotationally drive various paper feeding rollers to convey the paper P. And a print head driving unit 105 that controls ejection of ink droplets from the print head 44.

  The inkjet printer 1 includes a plurality of sensors that detect the state of the printer. For example, the inkjet printer 1 includes a paper detection sensor 45 that detects the presence or absence of the paper P in the transport path upstream of the print head 44, a PW sensor 47 that detects the presence or absence of the paper P immediately below the print head 44, and a black ink cover. Are provided with a black ink cover sensor 112 for detecting the opening / closing of the color ink cover 10, a color ink cover sensor 113 for detecting the opening / closing of the color ink cover 10, a paper cassette attaching / detaching sensor 114 for detecting whether the paper cassette 5 is attached. .

  The control unit 101 monitors signals from a PW sensor 47 provided in the print head 44 and a paper detection sensor 45 provided in the transport path during a paper feeding operation and a printing process. Further, the driving load of the carriage motor 14 by the carriage motor driving unit 102 and the driving load of the paper feeding motor 73 by the paper feeding motor driving unit 104 are monitored by a change in voltage or the like.

  Then, the control unit 101 detects the presence or absence of the paper P in the transport path based on these detection signals and voltage changes, and detects the driving status of the carriage 13 and the transport mechanism 11 for transport. Depending on the type of the paper P, after the front end of the paper P passes through the driven auxiliary roller 42a and before the rear end of the paper P passes through the conveying roller pair (paper feeding roller 41 and driven roller 42), The gap adjusting motor 63 is driven by the gap adjusting motor driving unit 103, and the driven auxiliary roller 42a is moved by a predetermined amount in a direction away from the platen surface 91a (that is, upward).

Control for moving the driven auxiliary roller 42a will be described with reference to the flowchart shown in FIG.
When the printer 1 receives a print execution command from the host computer 200, the control unit 101 determines the type of paper P to be printed based on the print data (step S01) included in the print execution command (step S02). In step S02, it is determined whether the paper P to be conveyed is plain paper or dedicated paper (super fine paper, matte paper, glossy paper, etc.).

  If it is determined in step S02 that the paper is a special paper, the release amount of the driven auxiliary roller 42a is further determined according to the type of the special paper (step S03). The nonvolatile memory of the control unit 101 stores a data table with an appropriate release amount corresponding to the type of dedicated paper. In step S03, the control unit 101 refers to the data table and follows the auxiliary auxiliary roller. The release amount of 42a is determined. For example, the release amount is set to 0.5 mm for super fine paper, 0.7 mm for matte paper, and 1.0 mm for glossy paper.

  After determining the release amount in step S03, the control unit 101 issues a paper feed operation execution command to the paper feed motor driving unit 104, and drives the paper feed motor 73 of the transport mechanism 11 to start the paper feed operation (step). S04). In step S04, the presence or absence of the paper P to be transported is detected by the paper detection sensor 45, and the front end of the paper P passes through the transport roller pair (the paper feed roller 41 and the driven roller 42) and the driven auxiliary roller 42a, and then the print head 44. The cueing operation is performed based on the detection signal of the PW sensor 47 provided on the head and the rotation amount (step number) of the paper feed motor 73.

  When the paper P is transported to the cueing position in step S04, the paper feeding operation ends (step S05), and then the gap adjustment motor driving unit 103 drives the gap adjustment motor 63 according to the release amount determined in step S03. Then, the rotation shaft 81 is rotated by a predetermined amount. As a result, the second release protrusion 82a pushes down the rear end of the auxiliary arm 77a to move the tip of the auxiliary arm 77a upward, and the driven auxiliary roller 42a moves upward (step S06).

  In step S06, as the rotary shaft 81 rotates, the inclined portion 58a of the cam surface 57b comes into contact with the cam receiver 59, and the adjustment operation of the gap PG according to the type of dedicated paper is also performed at the same time. Thus, the driven auxiliary roller 42a moves in conjunction with the operation in which the processing gap adjustment mechanism 51 finely adjusts the gap PG.

  After the end of step S06, the control unit 101 issues a print processing execution command to the carriage motor driving unit 102 and the print head driving unit 105, and drives the carriage motor 14 and the print head 44 based on the print data to start the printing process. (Step S09).

  If it is determined in step S02 that the paper is plain paper, the process related to the release of the driven auxiliary roller 42a is not executed. That is, the same paper feeding operation as in step S04 is started (step S07), and when the paper feeding operation is completed (step S08), the process proceeds to step S09 to start the printing process.

  When the printing process in step S09 is completed (step S10), a paper discharge operation is executed by the second transport unit (step S11). After the paper discharge operation is completed, the gap adjusting motor 63 is driven by the gap adjusting motor driving unit 103 to rotate the rotating shaft 81 in the reverse direction, and the released auxiliary roller 42a is returned to the original position (step S12).

  As described above, according to the inkjet printer 1 of the present embodiment, after the cueing of the paper P is completed, the driven auxiliary roller 42a is released and then the printing process is performed. That is, when the paper P is nipped by the pair of transport rollers and transported toward the platen surface 91a, the driven end is driven until the front end of the paper P passes the driven auxiliary roller 42a and the cueing operation of the paper P is finished. Since the auxiliary roller 42a is held in a predetermined pressing position and the paper P is pressed toward the platen surface 91a by the driven auxiliary roller 42a, the paper P is prevented from being lifted in the print processing mechanism 43, and a paper jam is generated. Can be prevented.

  After the cueing operation of the paper P is finished, the load applied to the paper P from the driven auxiliary roller 42a is reduced by releasing the driven auxiliary roller 42a before the start of printing. Even when the pair of transport rollers is removed or when the rear end of the sheet P passes through the driven auxiliary roller 42a, the variation in the sheet transport load is suppressed to a small level. As a result, it is possible to prevent a decrease in print processing accuracy and perform high-quality print processing.

  Note that when the paper P is plain paper, the paper stiffness is weaker than that of the special paper, so the fluctuation of the paper conveyance load is originally small, and high printing accuracy is not required. It was decided not to release. In other words, in plain paper printing, there is a tendency to prioritize the printing processing speed over the printing accuracy, and the throughput of plain paper printing is improved by not performing the release. However, when performing plain paper printing in the high-definition printing mode, the driven auxiliary roller 42a may be released.

  Further, since the release amount of the driven auxiliary roller 42a is adjusted according to the difference in the type (quality, thickness, etc.) of the paper P, the difference in transport load due to the difference in the type of the paper P can be reduced.

  Further, since the release of the driven auxiliary roller 42a is performed by transmitting power from the processing gap adjusting mechanism 51, it is not necessary to provide a dedicated drive source for moving the driven auxiliary roller 42a, and the cost of the printer 1 can be reduced. Can do. Further, by performing the release operation of the driven auxiliary roller 42a together with the adjustment operation of the gap PG, it is possible to efficiently perform an appropriate setting according to the type of the paper P. A release drive source for the driven auxiliary roller 42a may be provided separately.

  Note that the timing of releasing the driven auxiliary roller 42a may be any time after the front end of the sheet P has passed the driven auxiliary roller 42a and before the rear end of the sheet P has passed the transport roller pair. That is, if the driven auxiliary roller 42a is held at a predetermined position when at least the front end of the paper P passes through the driven auxiliary roller 42a, the sheet P conveyed on the platen surface 91a can be prevented from being lifted. Therefore, the release may be performed before the cueing operation is performed.

  In addition, even after the start of printing, the ink discharge operation and the paper transport operation are alternately performed for each length of the ink discharge nozzle during the print processing operation. It is also possible to release 42a. If the trailing edge of the sheet P passes through the pair of conveyance rollers, the variation in the conveyance load tends to increase. Therefore, if the driven auxiliary roller 42a is released until then, the variation in the conveyance load can be reduced.

  Moreover, the apparatus provided with the conveyance mechanism according to the present invention is not limited to the ink jet printer exemplified in the above embodiment. For example, the present invention can be applied to various devices having a similar transport path for transporting a medium such as a thermal printer, a copier, a fax machine, a scanner, a magnetic information reading device, a magnetic information recording device, and a bill changer. Even when a magnetic head that is a processing unit of the processing mechanism is in contact with a medium that is a medium, such as a magnetic information reader, if a jam is detected, the medium is urged to the magnetic head or the magnetic head. Providing the gap by moving the biasing member that is retracted from the conveyance path has the same effect as the above-described embodiment that makes it easy to pull out the jammed medium.

In the above-described embodiment, the driven auxiliary roller 42a is exemplified as a pressing portion that presses the medium toward the processing reference surface. However, other configurations such as a resin-molded plate-like member may be employed.
Further, although the flat platen 91 has been described as an example of the processing reference surface, it may be a roller platen.
In addition, although a sheet is described as an example of a sheet-like medium, a medium made of a resin film or the like is also applicable.

1 is an external perspective view of an inkjet printer according to an embodiment of the present invention. FIG. 2 is an external perspective view of a state where a paper discharge tray and an upper case are removed from the inkjet printer shown in FIG. 1. It is the external appearance perspective view which looked at the inkjet printer shown in FIG. 2 from the rear surface side upper side. FIG. 2 is a side cross-sectional view illustrating a sheet conveyance path in the ink jet printer illustrated in FIG. 1. FIG. 2 is a side sectional view showing a paper feeding state of the ink jet printer shown in FIG. 1. FIG. 2 is a side cross-sectional view illustrating a state where a cueing operation is performed in the ink jet printer illustrated in FIG. 1. FIG. 2 is a partial side cross-sectional view showing a processing gap adjusting mechanism in the ink jet printer shown in FIG. 1. FIG. 8 is a partial side cross-sectional view illustrating a state in which the processing gap adjustment mechanism illustrated in FIG. 7 is operated. FIG. 8 is a partial side cross-sectional view illustrating a state in which the processing gap adjustment mechanism illustrated in FIG. 7 is operated. FIG. 10 is a side cross-sectional view illustrating a state where power transmission between the drive motor and the intermediate roller in the conveyance path illustrated in FIG. 9 is interrupted. It is the top view which showed the support structure of a driven auxiliary roller. It is a block diagram which shows the control mechanism which controls the inkjet printer shown in FIG. 3 is a flowchart illustrating an example of operations during paper conveyance and printing processing in the inkjet printer illustrated in FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inkjet printer (recording apparatus), 2 ... Upper case, 3 ... Lower case, 4 ... Apparatus case, 5 ... Paper cassette, 6 ... Paper discharge tray, 11 ... Conveyance mechanism, 13 ... Carriage, 14 ... Carriage motor, 17 ... rear opening / closing cover, 31 ... intermediate roller, 32 ... retard roller, 41 ... paper feed roller, 42 ... driven roller, 42a ... driven auxiliary roller, 43 ... print processing mechanism (processing section), 44 ... print head, 48a ... discharge Paper roller, 48b ... driven roller, 51 ... processing gap adjusting mechanism, 53 ... carriage shaft, 55 ... transmission gear, 57 ... cam, 59 ... cam receiver, 63 ... gap adjusting motor, 73 ... paper feed motor, 78 ... first 1 release mechanism, 81 ... rotating shaft, 82 ... first release protrusion, 82a ... second release protrusion, 77 ... swing arm, 77a ... auxiliary arm, 84 ... one Way clutch mechanism, 91 ... platen, 91a ... platen surface (processing reference plane), A ... arc-shaped transport path, B ... straight transporting path, P ... paper (medium)

Claims (9)

A transport mechanism that transports the medium to a processing unit that performs information processing on a sheet-like medium on a processing reference surface;
A pair of conveyance rollers for nipping the medium and conveying the medium from the supply side onto the processing reference surface;
A pressing portion that presses the medium that has passed through the pair of conveying rollers toward the reference surface for processing, and
The transport mechanism, wherein the pressing portion is movable in a direction away from the processing reference plane independently of the transport roller pair. The transport mechanism according to claim 1,
A transport mechanism characterized in that the amount of movement of the pressing portion can be adjusted. The transport mechanism according to claim 1 or 2,
A processing gap adjusting mechanism for adjusting a gap between the processing reference surface and the processing unit;
The transport mechanism, wherein the pressing portion moves by power transmission from the processing gap adjusting mechanism. It is a conveyance mechanism as described in any one of Claim 1 to 3,
The timing at which the pressing unit moves is set after the front end of the medium has passed through the pressing unit and before the rear end of the medium has passed through the transport roller pair. mechanism. A transport mechanism according to any one of claims 1 to 4, comprising:
The recording apparatus, wherein the processing unit includes a print head that performs a printing process on the medium. A control method for a transport mechanism that transports the medium to a processing unit that performs information processing on a sheet-like medium on a processing reference surface,
The transport mechanism includes a transport roller pair that sandwiches the medium and transports the medium from the supply side onto the processing reference surface, and a pressing unit that presses the medium that has passed through the transport roller pair toward the processing reference surface. With
After the front end of the medium passes through the pressing unit, the pressing unit is used for the processing independently from the conveying roller pair until the rear end of the medium passes through the conveying roller pair. A method for controlling a transport mechanism, wherein the transport mechanism is moved in a direction away from a reference plane. It is a control method of the conveyance mechanism according to claim 6,
A control method of a transport mechanism, characterized in that an amount of movement of the pressing portion is adjusted according to a type of the medium to be transported. It is a control method of the conveyance mechanism according to claim 7,
The transport mechanism includes a processing gap adjustment mechanism that adjusts a gap between the processing reference surface and the processing unit,
According to the type of the medium to be conveyed, the movement amount of the pressing portion is adjusted together with the gap adjusting operation by the processing gap adjusting mechanism. A method for controlling a transport mechanism according to any one of claims 6 to 8,
Immediately after the medium is cued to the processing unit by the conveying roller pair, the pressing unit is moved in a direction away from the processing reference plane independently of the conveying roller pair. A control method of the transport mechanism.

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