JP2010222130A - Paper feeding unit for printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding unit restricting double feeding of a printing medium and preventing a surface of the printing medium from being damaged. <P>SOLUTION: The paper feeding unit for a printer includes: a pick-up roller 56 to be brought into contact with the top surface of a placed print medium P to apply a carrying-out force to the printing medium P; and a friction roller 51 provided under the pick-up roller 56 so as to be brought into contact with a lower surface of the printing medium P when conveying out the printing medium P to apply friction force to the printing medium P. A friction pad 52 and a guide roller 53 are arranged outside the friction roller 51 in the axial direction, and a second contact level L2 of the top surface of the friction pad 52 is set higher than a first contact level L1 of the top surface of the friction roller 51, and a third contact level L3 of the guide roller 53 thereby becomes higher in contact to prevent a phenomenon where excessive force is applied to the printing medium P from the friction pad 52. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a paper feeding unit of a printing apparatus that stores sheet-like print media in a stacked state.

  As a paper feeding unit of the printing apparatus configured as described above, Patent Document 1 discloses that a paper table 5 having a friction member 6 is rotated by rotating a paper feeding roller 5 until it faces the paper feeding roller 5. The point which makes it move, and rotates the push-up board 9 after this is described. Then, the paper feed portion 5a of the paper feed roller 5 is moved in a state where the friction member 6 is in contact with the lower surface of the paper P (print medium of the present invention) placed on the push-up plate 9 by the rotation of the winding table 7. It is described that the first sheet P is pressed against the sheet P and pulled out, and at the same time, the next sheet P is brought into contact with the friction member 6 and retained to suppress double feeding.

  In Patent Document 1, next, after the paper P is in contact with the paper feed roller 5, the pulling-up plate 9 is lowered and the paper feed roller 5 further rotates and stops at the home position. The point which rotates the winding stand 7 with the dynamic spring 11 is described.

  Further, Patent Document 2 discloses that a feed roller 13 made of rubber or the like at an end position of the feed tray 3 and a friction pad made of a material having a friction coefficient smaller than that of the feed roller 13 at a position facing the feed roller 13. 7 is shown.

  In this Patent Document 2, a mounting plate 1 on which a sheet material S (print medium of the present invention) is loaded is supported so as to be rotatable around a support shaft 2a, is urged upward by a pressure spring 3, and is supported by a support shaft 5a. A separation pad 4 is provided on a support member 5 that is rotatably supported around the periphery. A rotation type cam 6 that presses the support member 5 is provided. A sheet feeding rotating body 15 is disposed above the separation pad 4, and overlaps with a position that is exposed when the separation pad 4 is pushed down by the rotation type cam 6. A feed preventing member 13a is provided.

  In this patent document 2, when the sheet material S is placed on the placement plate 1, the separation pad 4 and the placement plate 1 are in a lowered position. They are in a separated positional relationship. By actuating the actuator 31a, the cam 6 and the sheet feeding rotator 15 start to rotate, the placing plate 1 rotates upward, and sheet feeding of the sheet S is started by the sheet feeding rotation 15. . Thereafter, the placing plate 1 and the separation pad 4 are pushed down, and the sheet material S that has been transported to the sheet S is locked by the double feed preventing member 13a, thereby preventing double feed.

JP 2007-168956 A (paragraph numbers [0015] to [0026], FIGS. 1 to 12) Japanese Patent Laid-Open No. 06-16269 (paragraph numbers [0017] to [0029], FIGS. 1 to 4)

  In this type of paper feeding unit, it is important to perform an operation of pulling out one print medium from a stacked print medium. In Patent Document 1 and Patent Document 2, an unloading roller and a position opposed to this are provided. In addition to changing the positional relationship with the pad, there is provided a configuration for changing the positional relationship between the placement plate on which the print medium is placed and the carry-out roller. However, when the print medium is carried out, a carry-out roller is brought into contact with the upper surface and a pad that makes a frictional force act on the lower surface, but double feed can be prevented by resistance force acting from the pad. In a situation where the print medium does not occur, the pad may come into contact with the lower surface of the print medium, thereby causing a scratch on the lower surface side of the print medium.

  In particular, in print media that enable photographic quality printing on both the front and back sides, it is not only required to prevent the occurrence of double feed, but scratches caused by the pads coming into contact with the lower surface side of the print media are also required. Control is also required.

  If the center of the print medium protrudes upward or causes curling to protrude downward as a cause of causing double feed to the print medium, the pad is placed against the print medium to be double fed. It is also conceivable that they cannot contact each other with a predetermined pressure and act on an appropriate resistance force.

  An object of the present invention is to rationally configure a paper feeding unit that suppresses double feeding of print media and at the same time hardly scratches the surface of the print media.

A feature of the present invention is a paper feeding unit of a printing apparatus that accommodates sheet-like print media in a stacked state,
A pick-up roller that contacts the upper surface of the print medium placed on the placement plate and causes a carry output to act, and contacts the lower surface of the print medium at a position facing the pick-up roller to rub against the carry-out of the print medium A friction roller for applying force,
A friction pad that applies a friction force when the print medium is carried out and a guide body that smoothly guides by contacting the lower surface of the print medium are arranged adjacent to each other at a sorting position that sandwiches the friction roller from the axial direction, In the axial direction of the friction roller, the friction pad and the guide body are arranged in parallel in the direction far from the position near the friction roller, and the contact level of the guide body with respect to the print medium is higher than the contact level of the friction pad with respect to the print medium. Is set high.

According to this configuration, when the print medium is carried out by the conveying force from the pickup roller that is in contact with the upper surface of the print medium, the friction roller at a position facing the pickup roller on the lower surface of the print medium is placed on the lower surface of the print medium. Since the frictional force is applied, the friction roller is not scratched. In addition, although the friction pad in a position aligned in the axial direction of the friction roller also contacts the lower surface of the print medium and exerts a frictional force, the guide body lifts the lower surface of the print medium from the friction pad due to the difference in contact level. Since the force is applied, the phenomenon that the friction pad strongly contacts the lower surface of the print medium is suppressed, and no scratches are caused.
Therefore, a paper feeding unit that suppresses the double feeding of the print medium and hardly damages the surface of the print medium is configured.

In the present invention, the contact level of the friction roller with respect to the print medium may be set lower than the contact level of the friction pad.
According to this, since the contact level of the friction pad is higher than the contact level of the friction roller and the contact level of the guide body is higher than this, when the print medium is sent to this part, the print medium is connected to the friction roller. From this position, a smooth concave shape is formed between the friction pad and the guide body, and the phenomenon that the lower surface of the print medium is locally brought into contact with the friction pad can be avoided.

In the present invention, the upper surface of the friction pad may be formed into an inclined surface that becomes lower toward the side closer to the friction roller.
According to this, even when the print medium curls into a smooth concave shape from the pick-up roller and the friction roller to the friction pad and the guide body from the pressure contact position, the outer edge of the upper surface of the friction pad is strongly against the lower surface of the print medium. There is no contact.

According to the present invention, the guide body is constituted by a guide roller that is loosely supported around an axis parallel to the axis, and the outer edge of the friction pad is carried out of the print medium on the basis of the outer periphery of the guide roller. A protruding portion having a shape protruding upstream in the direction may be formed, and the protruding portion may be disposed at an upstream position in the carry-out direction with reference to a position where the pickup roller and the friction roller are opposed to each other.
According to this, when the print medium is carried out, it comes into contact with the friction pad before the print medium reaches the position where the pickup roller and the friction roller face each other, and the print medium adheres to the lower surface of the print medium. In this case, the attached print medium can be separated by the frictional force from the friction pad. Further, since the guide body is composed of guide rollers, the print medium can be smoothly carried out.

According to the present invention, the placing plate swings around an axis in a horizontal posture so as to move up and down a carry-out side end which is downstream in the carry-out direction of the print medium in a state where the print medium is placed. After unloading the print medium, when the print medium is unloaded, the unload-side end is moved upward to bring the loaded print medium into contact with the pickup roller. After unloading by the pickup roller is started, The operation of moving the unloading side end downward may be performed.
According to this, it is possible to carry out the print medium placed on the placement board by moving the carry-out side end portion of the placement board upward, and after the carry-out is started, the carry-out of the placement board is started. By moving the side end portion downward, the print medium to be carried out and the print medium on the lower side are separated, and the resistance acting on the print medium to be carried out from the lower print medium is reduced. At the same time, double feeding is also suppressed.

It is a perspective view which shows a printing apparatus from a different direction. It is a vertical side view of a printing apparatus. FIG. 3 is a vertical side view of a paper feeding unit connected to a printing apparatus main body. FIG. 4 is a side view of a paper feeding unit connected to a printing apparatus main body. FIG. 6 is a cross-sectional plan view of the paper feeding unit. It is a top view which shows the structure of a guide width adjustment mechanism. It is sectional drawing which shows the structure of a position control body. It is a disassembled perspective view which shows the positional relationship of an action | operation arm, a lock plate, etc. It is a figure which shows arrangement | positioning of a friction pad, a guide roller, etc. It is a perspective view which shows a bracket, a friction pad, and a guide roller. It is the vertical side view and cross-sectional plan view of the carrying-out side edge part of the mounting board of a locked state. FIG. 6 is a longitudinal side view and a transverse plan view of a carrying-side end portion of a mounting plate when carrying out a print medium. It is a vertical side view which shows the state which descended the carrying-out side edge part of the mounting board to the intermediate position, and the state which descended to the lower end position.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
〔overall structure〕
As shown in FIGS. 1 to 3, a sheet-like unit B and a collection unit C are provided at the front position of the printing apparatus main body A, and the sheet shape is carried out of the printing apparatus main body A from the paper feeding unit B. A printing unit D that ejects ink onto the printing medium P to print image information, character information, and the like; a cutting unit E that cuts the printed medium P after printing; and a printing medium that blows dry air onto the printing medium P Printing is provided with a drying unit F that dries P, a transport unit G that transports the dried print medium P to the collection unit C, and an auxiliary transport unit H that realizes printing of the artificially supplied print medium P. The device is configured.

  In this printing apparatus, a drawer-like collection container 3 is provided so as to collect a container 2 for a plurality of ink cartridges 1 and a cut piece of the print medium P cut by the cutting part E at the lower part on the front side of the printing apparatus main body A. And are arranged. Further, a slit-shaped manual opening 4 for artificially supplying the print medium P is formed on the upper surface of the printing apparatus main body A. Further, inside the printing apparatus main body A, a control apparatus 5 having a microprocessor is provided so as to realize various processes such as carrying the printing medium P and performing printing in the printing unit D.

[Details of the configuration of each part of the device body]
The print unit D includes a paper sensor 10 that detects the tip position of the print medium P, and an advance roller 11 that presses against the print medium P at two locations on the upstream side and the downstream side in the transport direction of the print medium P to apply a transport force. And an electric motor (not shown) for driving the advance roller 11. Further, in this printing section D, at the intermediate position between the two advance rollers 11, a reference plate 12 disposed below the transport path of the print medium P, and the transport direction of the print medium P above the reference plate 12 Two print heads 13 that reciprocate in the orthogonal main scanning direction, and a suction unit that applies a negative pressure to the print medium P on the reference plate 12 through a number of openings (not shown) formed in the reference plate 12. 14.

  In the print unit D, the print medium P conveyed by the advance roller 11 is brought into close contact with the upper surface of the reference plate 12 by the negative pressure acting from the suction unit 14. In this close contact state, the print head 13 is reciprocated in the main scanning direction, and ink is ejected onto the upper surface of the print medium P in synchronism with this reciprocation, thereby realizing print processing such as image information and character information on the print medium P. To do.

  The cutting unit E arranges the upper blade 16 and the lower blade 17 that are in a posture orthogonal to the conveyance direction of the print medium P in a shearing positional relationship, an electric motor (not shown) that drives the lower blade 17, and a cutting position. A sensor (not shown) for optically detecting the marking of the printing medium and a guide cylinder 18 for guiding the cut print medium piece in the dropping direction are provided.

  In this cutting part E, when the marking indicating the cutting position printed on the front end side or the rear end side of the print medium P is detected by the sensor, a part of the print medium P is operated by operating the lower blade 17 upward. Is disconnected. The print medium piece separated in this way is guided downward by the guide cylinder 18 and collected by the collection container 3. The collection container 3 has a drawer-like structure with an open top, and the collected print medium piece can be discarded by being pulled out to the front of the printing apparatus main body A.

  As the cutting operation, the upper blade 16 may be operated downward, or the print medium P is cut by linearly operating a single cutter blade in the width direction of the print medium P. It may be a thing. This cutting is not always performed, but is performed according to the print form.

  The drying unit F includes a drying conveyance roller 20 that presses against the print medium P and applies a conveyance force at two locations on the upstream side and the downstream side in the conveyance direction of the print medium P, and an electric motor that drives the drying conveyance roller 20. (Not shown) and a blower 21 that blows dry air onto the print medium P from above the transport path of the print medium P at an intermediate position between the two dry transport rollers 20.

  The transport unit G includes a plurality of pressure-bonding-type transport rollers 24 that transport the print medium P, a guide plate 25 that guides the print medium P, and the print medium P transported by the plurality of transport rollers 24 to the collection unit C. A pressure-feed type discharge roller 26 that feeds out, and a discharge guide plate 27 that is disposed upstream of the discharge roller 26 in the conveyance direction of the print medium P are provided.

  Although not shown in the drawing, the plurality of transport rollers 24 are driven synchronously by an electric motor (not shown), and the discharge roller 26 is driven by a dedicated electric motor (not shown). With this configuration, in the transport unit G, the print medium P sent out from the drying unit F to the rear side is transported upward, then transported horizontally forward, and discharged from the discharge roller 26 to the collection unit C. Is carried out.

  The auxiliary transport unit H includes a discharge roller 26 and a discharge guide plate 27 of the transport unit G, and has a function of directly feeding the print medium P artificially inserted into the manual feed opening 4 to the print unit D. is doing. The auxiliary transport unit H includes a discharge roller 26 and a discharge guide plate 27, and further includes a vertical guide plate 28 and a supply roller 29 on the downstream side in the transport direction. In order to realize such conveyance, the discharge roller 26 and the discharge guide plate 27 swing around one axis of the discharge roller 26.

  With this configuration, when executing the printing process using the auxiliary transport unit H, the discharge roller 26 and the discharge guide plate 27 are swung so as to transport the print medium P in the vertical direction, Then, the operation of driving the supply roller 29 and supplying the print medium P from the manual feed opening 4 is performed. As a result, the print medium P is sequentially conveyed to the discharge roller 26, the discharge guide plate 27, the vertical guide plate 28, and the supply roller 29, and the printing process is realized in the printing unit D.

  This printing apparatus is configured to be able to print on both sides of the print medium P. That is, when performing both-side printing, after the print medium P carried out from the paper supply unit B is printed by the print unit D and cut by the cutting unit E, the rear end of the print medium P is printed. Is carried by the carrying unit G until it reaches the part of the discharge roller 26. Next, the discharge roller 26 and the discharge guide plate 27 are swung in the direction in which the print medium P is fed to the auxiliary transport unit H, and the discharge roller 26 is reversed so that the print medium P is supplied to the print unit D to reverse the back surface. Side printing.

  The collection unit C includes a tray-like container 31 that is detachably provided in a form protruding forward from the front surface of the main body case. Further, a rack plate 32 on which the print medium P can be placed is provided at an upper position of the collection unit C.

[Paper Feed Unit]
As shown in FIGS. 3 to 6, the paper feeding unit B is configured as a cassette that is detachable from the printing apparatus main body A of the printing apparatus. The sheet feeding unit B has a level at an end portion on the counter-unloading side (hereinafter referred to as an anti-unloading side end portion) with respect to a level at an end portion (hereinafter referred to as an unloading side end portion) of the print medium P. Is connected to the printing apparatus main body A in a generally inclined posture so as to be slightly higher.

  The paper feeding unit B includes a lower case 41 made of resin, an upper case 42 made of resin so as to cover an upper portion of the end of the print medium P on the lower case 41, and an unloading side of the upper case 42. A case Bc having a sealed structure is configured by including an open / close case 43 made of a transparent resin that is supported to be openable / closable with respect to the end portion.

  In the case Bc, the upper case 42 and the open / close case 43 are slidably connected by a hinge shaft 44 in a lateral orientation, and a handle 45 is provided on the upper surface of the open / close case 43 when the operator carries it. A buckle 46 is provided between the open / close case 43 and the lower case 41 to close the open / close case 43 in a closed position.

  In the case Bc, a slit-shaped outlet 47 for discharging the accommodated print medium P is formed between the lower case 41 and the upper case 42. In addition, an ID plate 48 on which information such as the size and type of the accommodated print medium P is set is provided on the wall portion of the carry-out side end portion of the lower case 41, and also provided in the printing apparatus main body A. An operation opening 49 through which the operation arm 87 is inserted and an operation hole 36 through which the operation rod 35 protruding from the printing apparatus main body A is inserted are formed.

  The operation opening 49 is provided with a shutter 50 biased to a closed position. When the paper feeding unit B is connected to the printing apparatus main body A, the shutter 50 is opened by the pressing force of the operation rod 35, and thus The operation arm 87 is inserted into the operation opening 49 where the shutter 50 is opened. When the shutter 50 is thus opened, the operation opening 49 also functions as a vent that allows air to flow inside the case Bc of the printing apparatus main body A.

  When the paper feeding unit B is detached from the printing apparatus main body A, the shutter 50 closes the operation opening 49 by the spring biasing force, the case Bc is in a sealed state, and the carry-out side end of the mounting plate 55 described later is the lower end. It is locked in a posture maintained in position (these modes of operation will be described later). The ID plate 48 includes a plurality of DIP switch-like operation pieces, and the position of the operation piece is set according to the size of the print medium P, the type of the print medium P, and the like. By detecting the operation position by a sensor (not shown) provided in the printing apparatus main body A, the size, paper type, and the like of the print medium P accommodated in the case Bc are grasped by the printing apparatus main body A.

[Paper Feed Unit-Placement Plate]
Inside the case Bc, a sheet-like print medium P is placed in a stacked state, and a mounting plate 55 that can swing around a horizontal axis X is provided. The mounting plate 55 is placed in a stacked state. A pick-up roller 56 that contacts the upper surface of a certain uppermost print medium P and causes a carry-out output is provided, and a guide wall 60 that guides the lower surface of the print medium P carried out by the pick-up roller 56 is provided. A regulation wall 62 that is arcuate in a side view is formed so as to be directed downward from the guide wall 60 and along the movement trajectory of the unloading side end portion of the mounting plate 55 centered on the axis X.

  On the lower surface side of the mounting plate 55, a support shaft 63 that is coaxial with the axis X is provided at the center position of the mounting plate 55 in the carry-out direction of the print medium P. By supporting both ends of the support shaft 63 on the lower case 41, the carry-out side end of the mounting plate 55 can be moved in the vertical direction around the axis X. In the vicinity of the carry-out side end of the mounting plate 55, a lift spring 64 is provided that applies a biasing force in the direction of lifting the carry-out end.

  On the upper surface of the mounting plate 55, a position restricting body 65 that determines the position of the end of the print medium P on the side opposite to the carry-out side and a pair of left and right guide bodies 66 that restrict the position of the end in the width direction of the print medium P are provided. ing. The position restricting body 65 is formed by bending a metal plate as shown in FIG. 7, and is supported by the mounting plate 55 so as to be movable in a direction along the carrying-out direction of the print medium P. The guide body 66 is set in a vertical posture with respect to the mounting plate 55 and is supported by the mounting plate 55 so as to be movable in a direction (width direction) orthogonal to the carrying-out direction of the print medium P.

  On the lower surface side of the mounting plate 55, a guide width adjusting mechanism W that moves the pair of left and right guide bodies 66 in opposite directions is provided. As shown in FIGS. 5 and 6, the guide width adjusting mechanism W includes a rotary operation type knob 67 provided at the end of the mounting plate 55 and a pair of screw shafts 68 that are rotated by the rotational force of the knob 67. And a timing belt 69 that rotates the pair of screw shafts 68 in an interlocking manner. Furthermore, a nut 68N that is screwed to the right screw portion 68S of the screw shaft 68, a nut 68N that is screwed to the left screw portion 68T of the screw shaft 68, and a pair of sliders 70 that support each nut 68N are provided. A connecting body 70 </ b> A that connects to the guide body 66 is formed in 70.

  A slit 55S through which the connecting body 70A is inserted is formed in the mounting plate 55 along the width direction of the print medium P, and the connecting body 70A is inserted through the slit 55S. Thereby, by rotating the knob 67, the pair of screw shafts 68 rotate in the same direction, and the moving force from the nut 68N screwed into the right screw portion 68S of each screw shaft 68 and the left screw portion 68T. The moving force from the nut 68N screwed to the slider 70 acts on the slider 70 in opposite directions. As a result, the guide body 66 coupled to the slider 70 via the coupling body 70A moves in the opposite direction, and the guide body 66 can be set at a position corresponding to the width of the print medium P.

  A guide groove 55A into which the base portion 65B of the position restricting body 65 is inserted and a plurality of guide grooves 55A are formed along the guide groove 55A to prevent the base portion 65B from being lifted at the center position in the width direction of the mounting plate 55. A lifting prevention piece 55B and a large number of lock grooves 55C formed continuously in the carry-out direction at the center in the width direction of the guide groove 55A are formed.

  The position restricting body 65 includes a plate-shaped main body 65A that is inclined with respect to the mounting surface of the mounting plate 55, and is movable along the guide groove 55A and supported in a state that suppresses lifting. A lock body 65C that includes 65B and is operable in the vertical direction is provided. The lock body 65C is engaged with any one of the many lock grooves 55C to reach a locked state, and can be locked at a position corresponding to the size of the print medium P.

  A film-like friction material 55F made of rubber or resin is provided at the center position in the width direction on the upper surface of the carry-out side end portion of the placement plate 55, and the remaining amount of the print medium P placed on the placement plate 55. When the upper print medium P is carried out, a friction force is applied to the lower surface side of the lower print medium P from the friction material 55F to prevent double feeding.

[Paper Feed Unit-Pickup Roller]
Under the pickup roller 56, a frictional force is applied while rotating by contacting the lower surface of the print medium P (a frictional force may be applied in a non-rotating state), a friction pad 52, And a guide roller 53 as a guide body. The friction roller 51 and the friction pad 52 constitute a frictional force acting means. Note that a rotating member such as the guide roller 53 is not necessarily used as the guide body. For example, a resin or metal having a smooth surface and a small friction coefficient may be used.

  The friction roller 51 is disposed at a boundary portion between the guide wall 60 and the regulation wall 62, and the friction roller 51 is supported by the shift frame SF via a shaft body 51a. The friction roller 51 is rotatably supported with respect to the shaft body 51a, and a frictional force acts between the friction roller 51 and the shaft body 51a with respect to the rotation when the print medium P moves in the carry-out direction. And a frictional force applying mechanism 51b having a one-way clutch so that the print medium P is rotated lightly when the print medium P is moved in the anti-unloading direction.

  The friction pad 52 and the guide roller 53 are distributed and arranged at positions where the friction roller 51 is sandwiched from the axial direction while being supported by the bracket 54, and the bracket is detachably attached to the shift frame SF. The bracket 54 is formed in a form in which a concave space 54A in which the friction roller 51 is disposed is cut out at the center position of the upper end, and a friction pad 52 is disposed on this side portion (a position adjacent in the axial direction of the friction roller 51). ing. Further, the guide roller 53 is provided so as to be freely supported with respect to the guide shaft 53A in a state in which the guide roller 53 is fitted in the slit portion 54B located outward in the axial direction. As a result, the friction pad 52 is arranged at a position where the friction roller 51 is sandwiched from the axial direction, and the guide roller 53 is arranged at a position outside the friction pad 52 (on the anti-friction roller side) in the axial direction and close to the friction pad 52. Is done.

  The position where the friction roller 51 contacts the lower surface of the print medium P is referred to as a first contact level L1, the position where the friction pad 52 contacts the lower surface of the print medium P is referred to as a second contact level L2, and the friction pad 52 is the print medium. When the position in contact with the lower surface of P is referred to as a third contact level L3, the second contact level L2 is set higher than the first contact level L1, and the third contact level L3 is set higher than the second contact level L2. ing.

  Further, a portion of the upper surface of the friction pad 52 that is close to the friction roller 51 is formed as an inclined surface 52T that becomes lower as the position is closer to the friction roller 51, and the outer edge of the friction pad 52 is based on the outer periphery of the guide roller 53. A protruding portion 52F having a shape protruding toward the upstream side in the carry-out direction of the print medium P is formed. Further, the friction pad 52 and the guide roller 53 are arranged at an upstream position in the carry-out direction from a position where the pickup roller 56 and the friction roller 51 press the print medium P.

  The pickup roller 56 and the friction roller 51 are formed of rubber or resin on the outer periphery, the friction pad 52 is formed of rubber, urethane resin, or the like, and the guide roller 53 has a smooth outer peripheral surface and is harder than rubber or urethane resin. It is formed with. The friction coefficient of the friction roller 51 and the friction pad 52 is set lower than the friction coefficient of the pickup roller 56.

  Thus, since the frictional force acting means is configured, when the print medium P placed on the placement plate 55 is carried out, the print medium P is reached before reaching the position where the pickup roller 56 and the friction roller 51 are pressure-bonded. Since the lower surface side of the friction plate 52 comes into contact with the projecting portion 52F of the friction pad 52, when the print medium P adheres to the lower surface of the print medium P, it adheres due to the frictional force from the projecting portion 52F of the friction pad 52. It is possible to separate the print medium P, and supply only the uppermost sheet between the pickup roller 56 and the friction roller 51.

  Thereafter, when the position where the pickup roller 56 and the friction roller 51 are pressed is reached, the center of the print medium P in the width direction is set to the lowest level as shown in FIGS. The outer side is lifted by the friction pad 52 and the guide roller 53, and the outer side further becomes a smooth concave shape depending on the weight of the print medium P. Even in such a shape, when the left and right guide rollers 53 come into contact with the lower surface of the print medium P, the phenomenon that the upper surfaces of the left and right friction pads 52 strongly come into contact with the print medium P can be suppressed. Friction resistance is applied to the lower surface, and even if the print medium P adheres to the lower surface of the print medium P, friction force is applied to the lower surface of the attached print medium P from the friction pad 52 for separation. Promote. In particular, since the inclined surface 52T formed on the friction pad 52 is formed on the inclined surface where the portion close to the friction roller 51 is lowered, the phenomenon that the corner portion of the friction pad 52 strongly contacts the lower surface side of the print medium P is caused. Can be avoided. As a result, even if double feeding occurs in the print medium P at the portion where the pickup roller 56 and the friction roller 51 are pressure-bonded, the lower print medium P can be efficiently separated from the uppermost print medium P. .

  The relative posture between the guide wall 60 and the case Bc of the paper feed unit B is set so that the upper surface of the guide wall 60 is in a horizontal posture with the paper feed unit B connected to the printing apparatus main body A. ing. The upstream advance roller 11 is disposed at a position where the print medium P transported horizontally from the transport outlet 47 in a form guided by the upper surface of the guide wall 60 is pressed.

  As described above, the pickup roller 56 is made of a material having a high coefficient of friction, such as rubber or resin material, with respect to the outer periphery of the cylindrical body that rotates integrally with the metal roller shaft 57 that is loosely supported on the lower case 41. The roller shaft 57 is provided with an input gear 58 that rotates integrally with the roller shaft 57.

  As shown in FIG. 4, when the paper feeding unit B is connected to the printing apparatus main body A, the printing apparatus main body A is provided with a drive gear 59 that meshes with the input gear 58, and this driving gear 59 is electrically driven. Driven by the paper motor M1.

  An opening / closing plate 82 is supported at a position opposed to the upper side of the guide wall 60 so as to be swingable around an opening / closing shaft 82 </ b> A in a lateral orientation, and an intermediate swinging body 83 that swings the opening / closing plate 82 is laterally directed to the lower side of the guide wall 60. It is supported so as to be swingable around the intermediate shaft 84 of the posture. A pair of projecting pieces 83A are formed at both end positions in the width direction of the intermediate rocking body 83 so as to face upward, and the intermediate rocking body 83 is linked with the rotation of the rotation block 75 (described below). By swinging, the shutter 50 is opened. When the shutter 50 is opened, the opening / closing plate 82 is maintained in the open posture.

[Operating structure of shutter and friction pad]
As shown in FIGS. 8 and 11 to 13, the mounting plate 55 is extended toward the unloading side end of the paper feeding unit B, and the operating arm swings integrally with the mounting plate 55. 71, a shaft portion 71A that is parallel to the axis X is formed at the swing end of the operating arm 71, and a contact portion 71B that is a roller that is freely loosely fitted to the shaft portion 71A is formed. ing.

  The shift frame SF is slidably supported in the vertical direction with respect to the vertical frame 72 and is urged upward by a shift spring 73. A contact piece 74A is formed at the lower end of the plate-like body 74 connected to the lower side of the shift frame SF. By being biased upward by the shift spring 73, the shift frame SF is shifted to the upper limit. In the state where the shift frame SF is shifted to the upper limit, there is a gap between the outer periphery of the friction roller 51 and the outer periphery of the pickup roller 56. A gap having a value smaller than the thickness of the print medium P is formed.

  In this way, by setting the gap between the outer periphery of the friction roller 51 and the outer periphery of the pickup roller 56 to a value smaller than the thickness of the print medium P, the conveyance of the print medium P of three sheets or the like is suppressed. . Note that the pickup roller 56 and the friction roller 51 may be in a positional relationship in contact with each other.

  As shown in FIGS. 11 and 12, the lower case 41 is provided with a rotation block 75 that can swing around a rotation axis Y in a vertically oriented posture, and a shutter 50 is connected to the rotation block 75. The urging force from the close spring 76 acts on the rotating block 75 in the direction in which the shutter 50 is closed. The rotating block 75 is integrally formed with a pair of upper and lower arms 75A that are rotatably supported by a shaft support disposed on the axis of the rotation axis Y, and is inserted into the operation hole 36. A pressed portion 75B to be pressed by the operating rod 35 is integrally formed, and a cam portion 75C for operating the intermediate rocking body 83 is formed on the upper surface.

  Further, the rotation block 75 is provided with a metal lock plate 77, and a recess 77 </ b> A is formed in the lower part of the lock plate 77. The recess 77A of the lock plate 77 and the shaft portion 71A of the operating arm 71 constitute a lock mechanism L.

  The lock mechanism L is located on the recess 77A when the sheet feeding unit B is removed from the printing apparatus main body A and the shutter 50 is switched to the closed position with the carry-out side end of the mounting plate 55 at the lower end. When the shaft portion 71 </ b> A of the operating arm 71 is engaged, the unloading side end portion of the mounting plate 55 functions so as to be maintained at the lower end. In this state where the mounting plate 55 is positioned at the lower end, the friction arm 51 and the shift frame SF are picked up by the operating arm 71 of the mounting plate 55 coming into contact with the contact piece 74A of the plate-like body 74. It is maintained at a position away from the roller 56.

  More specifically, when the paper feeding unit B is connected to the printing apparatus main body A, the operation rod 35 formed in the printing apparatus main body A is inserted into the operation hole 36 formed in the lower case 41, The distal end abuts against the pressed portion 75B and rotates the rotation block 75 about the rotation axis Y against the urging force of the close spring 76, thereby turning the rotation block 75 as shown in FIG. Rotate.

  In this rotating state, the shutter 50 formed on the rotating block 75 rotates integrally with the rotating block 75, so that the operation opening 49 is opened. When the paper feeding unit B is connected to the printing apparatus main body A, the operation arm 87 enters the inside of the paper feeding unit B through the open operation opening 49, and the tip of the operation arm 87 is a contact portion of the operating arm 71. The positional relationship is such that it can contact 71B.

  As will be described later, when printing is not performed by the printing apparatus, the tip of the operation arm 87 is in contact with the contact portion 71B of the operating arm 71 from above, and the portion is pushed down to the lower end position. Therefore, the carry-out side end portion of the placement plate 55 is at the lower end position, and the print medium P placed on the placement plate 55 is in a position not in contact with the pickup roller 56.

  When the sheet feeding unit B is pulled out and separated from the printing apparatus main body A in this state, the rotation block 75 is rotated by the urging force of the close spring 76 by an amount corresponding to the drawing amount of the sheet feeding unit B. Along with the rotation, the shutter 50 moves in the closing direction, and at the same time, the lock plate 77 moves in a direction in contact with the operating arm 71.

  By continuously pulling out the sheet feeding unit B, the shaft 71A of the operating arm 71 reaches a state where it is fitted into the recess 77A of the lock plate 77, and the urging force of the lift spring 64 acts on the mounting plate 55. Regardless, the end of the loading plate 55 on the carry-out side is maintained at the lower end position.

  Thus, as a result of maintaining the carry-out side end of the mounting plate 55 at the lower end position, the print medium P mounted on the mounting plate 55 does not fall into a state of being pressed against the pickup roller 56, and printing is performed. The deformation of the medium P and the deformation of the pickup roller 56 are suppressed. Further, the posture of the intermediate rocking body 83 is switched in conjunction with the rotation of the rotation block 75, the opening / closing plate 82 operated via the protruding piece 83A is operated to the closed posture, and the carry-out port 47 is closed.

〔Control device〕
In the printing apparatus main body A, the operation arm 87 described above is supported by the printing apparatus main body A so as to be swingable in the vertical direction around the support shaft 88, and a roller-shaped cam follower 89 protruding from the operation arm 87 is electrically driven. It is in contact with the outer cam surface of a rotating cam 91 that rotates integrally with an output shaft 90 driven by a mold operating motor M2. A transmission system is formed that transmits the driving force of the operation motor M2 to the output shaft 90 via a reduction gear, and a potentiometer 92 that measures the amount of rotation of the rotary cam 91 is provided. Then, the control device 5 controls the operation motor M <b> 2 in a state where the signal from the potentiometer 92 is fed back to the control device 5.

  In the present invention, a lift spring 64 that applies a biasing force in the direction of lifting the unloading side end of the mounting plate 55, an operation arm 87 that applies a force in a direction of pressing the unloading side end of the mounting plate 55, and this A drive elevating mechanism is configured by the operation motor M2 that swings and drives the operation arm 87.

  The operating arm 87 is urged by a torsion spring 93 so that the cam follower 89 is always in contact with the rotating cam 91. Then, when the operation arm 87 swings around the support shaft 88, the tip end portion 87A swings downward and contacts the contact portion 71B of the operating arm 71. Thereby, the mounting plate 55 is swung together with the operating arm 71. In the state where the distal end portion 87A of the operation arm 87 is not in contact with the contact portion 71B of the operating arm 71, the carry-out side end portion of the mounting plate 55 moves upward by the urging force of the lift spring 64.

  A carry-out path through which the print medium P is carried out by driving rotation of the pickup roller 56 is provided with a double feed detection sensor (not shown) that detects double feed of the print medium P. This double feed detection sensor has a light source and a light receiving element, and the control device 5 determines the presence or absence of double feed from the amount of light transmitted through the print medium P.

[Sequence of unloading operation]
In the printing apparatus, the control device 5 acquires a measurement signal from the potentiometer 92 and a measurement signal from the paper sensor 10 provided in the printing unit D, and the printing unit D, the cutting unit E, the drying unit F, and the transport unit. G and auxiliary transport unit H are controlled.

  When the print medium P is not carried out, the loading plate 55 has an unloading side end at the lower end position, and at this lower end position, the operating arm 71 of the loading plate 55 contacts the contact piece 74A of the plate-like body 74. By hitting, the friction roller 51 and the friction pad 52 are in a position shifted in a direction away from the pickup roller 56.

  When the print medium P is discharged from the paper supply unit B, the pickup roller 56 is rotated in the normal rotation direction at a low speed that corresponds to about 1/5 of the normal conveyance speed under the control of the paper supply motor M1. Immediately after this, the operating arm 87 is swung to the upper limit by the control of the operating motor M2, and this raised state is maintained for the first set time.

  By swinging the operation arm 87 to the upper limit in this way, the placing plate 55 also swings to the upper limit by the urging force of the lift spring 64. The upper limit is a swinging posture in contact with the uppermost print medium P among the print media P placed in a stacked state on the placement plate 55 as shown in FIGS. Further, at this time, the print medium P comes into contact with the pickup roller 56 in a state where the dynamic inertia acts on the pickup roller 56. Therefore, even when the friction coefficient of the pickup roller 56 is small, printing is performed using a large pressure due to the dynamic inertia. Since a strong force is applied to the medium P in the unloading direction, and the pickup roller 56 rotates at a low speed, the unloading can be surely started without causing a slip.

  Immediately before the top surface of the uppermost print medium P comes into contact with the pickup roller 56 and unloading is started, the protruding portion 52F formed on the friction pad 52 is brought into contact with the lower surface of the print medium P. The print medium P adhering to the lower surface side of the upper print medium P is separated, and only the uppermost sheet can be supplied between the pickup roller 56 and the friction roller 51.

  Further, when the carry-out side end of the mounting plate 55 rises to the upper limit, the friction roller 51 and the friction pad 52 move to a position close to the pickup roller 56 in conjunction with this. As a result, when the conveyance of the print medium P is started by being sandwiched between the pickup roller 56 and the friction roller 51, the first friction roller 51 in contact with the center in the width direction of the print medium P as shown in FIG. The first contact level L1 is set to the lowest level, and the outer side is raised to the second contact level L2 by contact with the friction pad 52, and the outer side further to the third contact level L3 by contact with the guide roller 53. Lifted. In this way, the left and right guide rollers 53 come into contact with the lower surface of the print medium P, so that the frictional resistance acts on the lower surface of the print medium P while suppressing the phenomenon that the upper surfaces of the left and right friction pads 52 strongly contact the print medium P. To prevent double feeding.

  In particular, since the inclined surface 52T formed on the friction pad 52 is formed on the inclined surface where the portion close to the friction roller 51 is lowered, the phenomenon that the corner portion of the friction pad 52 strongly contacts the lower surface side of the print medium P is caused. Can be avoided. By configuring the frictional force acting means in this way, even when a frictional force is applied to the lower surface side of the print medium P, no scratches are caused. Therefore, for example, even when the print medium P capable of photographic quality printing on both sides is conveyed, high-quality printing is realized without causing scratches on the print surface on the lower surface side. By this control, the print medium P is conveyed by a set distance.

  Next, as shown in FIG. 13A, the operating arm 87 is slightly lowered to lower the placing plate 55 to the intermediate position, and the rotation speed of the pickup roller 56 is normally increased in the normal rotation direction by the paper feed motor M1. The speed is increased to a speed corresponding to a high speed about twice the transport speed and maintained for the second set time. When the second set time elapses, the pickup roller 56 stops rotating. Immediately after this, the pickup roller 56 is rotated in the reverse direction at a speed corresponding to a high speed about twice the normal conveying speed. This rotation is maintained for a set time.

  At the above-described intermediate position, the operating arm 71 of the mounting plate 55 is located above the contact piece 74A of the plate-like body 74, and the friction roller 51 and the lower surface of the print medium P conveyed by the pickup roller 56 are placed. The state of contacting the friction pad 52 is maintained. Then, by lowering the placing plate 55 to the intermediate position, the print medium P positioned below the print medium P that has been transported by the pickup roller 56 is separated.

  By performing this control, when the print medium P is in a double feed state in which the print medium P is in close contact with the lower surface of the print medium P, the lower print medium P is transferred from the friction roller 51 and the friction pad 52 during conveyance in the carry-out direction. A frictional force is applied to promote separation of the lower print medium P, and further, the lower print medium P can be returned to the mounting plate 55 by moving in the opposite direction.

  In particular, when the print medium P is fed in the opposite direction, the friction roller 51 rotates with little frictional force acting on the print medium P, and the lower print medium P is placed on the placement plate 55. It will return smoothly.

  Next, the pickup roller 56 is driven by the paper feed motor M1 in the forward rotation direction at a speed corresponding to the normal transport speed, and this drive is maintained until the paper sensor 10 detects it, thereby realizing carry-out. Thereafter, as shown in FIG. 13B, by lowering the mounting plate 55 to the lower end, the friction roller 51 is lowered to release the pressure bonding of the friction roller 51, and the paper feed motor M1 is in a freely rotating state. By doing so, the print medium P is pulled out by the advance roller 11 and can be printed by the printing apparatus main body A.

  In this control, the carry-out of the print medium P has been described on the assumption that no multi-feed occurs. For example, a multi-feed detection sensor provided to detect a multi-feed with respect to a path through which the print medium P is carried out provides a multi-feed. If it is detected, it is conceivable to carry out the print medium P in the reverse direction again or to activate an alarm.

  As described above, according to the present invention, when the print medium P is carried out by the rational arrangement of the frictional force acting means including the friction roller 51, the friction pad 52, and the guide roller 53, the pickup roller 56, the friction roller 51, and the like. The protruding portion 52F of the friction pad 52 is brought into contact with the print medium P before being pressure-bonded by the pick-up roller by separating the print medium P even if the print medium P is in close contact with the lower side of the uppermost print medium P. A single print medium P can be supplied to 56. Further, when the pick-up roller 56 starts to carry out the print medium P, the print medium P is smoothly curved so that the central portion of the print medium P is concave, and an excessive frictional force is not applied so that no scratches are caused. It is possible to suppress double feeding.

  The present invention can be used in general printing apparatuses that form images.

51 Friction roller 52 Friction pad 52F Protruding portion 52T Inclined surface 53 Guide body (guide roller)
55 Mounting plate 56 Pickup roller P Print medium X Axle core

Claims (5)

A paper feeding unit of a printing apparatus that accommodates sheet-like print media in a stacked state,
A pick-up roller that contacts the upper surface of the print medium placed on the placement plate and causes a carry output to act, and contacts the lower surface of the print medium at a position facing the pick-up roller to rub against the carry-out of the print medium A friction roller for applying force,
A friction pad that applies a friction force when the print medium is carried out and a guide body that smoothly guides by contacting the lower surface of the print medium are arranged adjacent to each other at a sorting position that sandwiches the friction roller from the axial direction, In the axial direction of the friction roller, the friction pad and the guide body are arranged in parallel in the direction far from the position near the friction roller, and the contact level of the guide body with respect to the print medium is higher than the contact level of the friction pad with respect to the print medium. Is a feeding unit of a printing device that is set high.   The paper feeding unit of the printing apparatus according to claim 1, wherein a contact level of the friction roller with respect to a print medium is set lower than a contact level of the friction pad.   3. The paper feeding unit of a printing apparatus according to claim 2, wherein the upper surface of the friction pad is formed into an inclined surface that becomes lower toward a side closer to the friction roller.   The guide body is composed of a guide roller that is idle-supported around an axis parallel to the axis, and the outer edge of the friction pad is upstream in the carry-out direction of the print medium with respect to the outer periphery of the guide roller. A projecting portion having a shape protruding in the shape is formed, and the projecting portion is disposed at an upstream position in the unloading direction with reference to a position where the pickup roller and the friction roller are opposed to each other. A paper feeding unit of the printing apparatus according to any one of the above.   The mounting plate is swingably supported around a horizontal axis so as to move up and down the unloading side end that is downstream in the unloading direction of the print medium in a state where the print medium is mounted. When the print medium is unloaded, the unload side end is moved upward to bring the print medium placed thereon into contact with the pickup roller. After unloading by the pickup roller is started, the unload side The sheet feeding unit of the printing apparatus according to claim 1, wherein an operation of moving the end portion downward is performed.

Images