JP2006089170A - Sheet feeding device and sheet feeding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeding device capable of obtaining a stable sheet feeding power even when a sheet is curled, paper dust or the like is generated from the sheet when the sheet is a recording paper sheet or the like. <P>SOLUTION: The sheet feeding device comprises a moving mechanism to move a needle-like member 312 to be bitten into a sheet in the sheet feeding direction, and an advancing/retracting mechanism to advance/retract the needle-like member 312 to/from a sheet P1 located on an end of a sheet bundle P. The needle-like member 312 is bitten into one sheet located on one end of the sheet bundle P by advancing the needle-like member 312 toward an end of the sheet bundle. The sheet P1 is then taken out of the sheet bundle P1 by moving the needle-like member 312 in the sheet feeding direction by the moving mechanism. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet feeding apparatus and a sheet feeding method for taking out and feeding one sheet from a plurality of stacked sheets.

In general, in an image forming apparatus such as a printer or a copier, a sheet is separated from a plurality of sheets stacked on a sheet stacking unit by a sheet feeding unit and is fed to an image forming unit. A feeding device is provided.
Conventionally, the sheet feeding means is for picking up only one sheet from a pick-up roller, which is a rotating body arranged so as to be able to contact and separate from the sheet, and one or a plurality of sheets fed by the pick-up roller. And a separating means. The separation means includes a separation pad formed by a high friction member, and a separation roller which is provided so as to come into contact with and separate from the separation pad and is a rotating body that separates the sheet from the separation pad.

  In such a conventional sheet feeding apparatus, when a recording start signal is input, a pickup roller as a rotating body comes into contact with the sheets stacked on the sheet stacking unit, and one or a plurality of sheets P are fed out. Then, the sheet is conveyed to a pressure contact portion between the separation roller and the separation pad, and conveyed to the downstream side while being separated one by one between the separation pad and the separation roller.

  Further, after the sheet is conveyed to the downstream side by the pressure contact portion between the separation roller and the separation pad, the pickup roller moves away from the sheet, and the separation roller further presses the sheet at the pressure contact portion with the separation pad. After separating each, it moves away from the separation pad.

Japanese Patent Laid-Open No. 7-100039

However, in the conventional sheet feeding apparatus as described above, the sheet feeding is performed by rotating the pickup roller, which is a rotating body, as the sheet feeding unit. In addition, when the sheet is curled, there is a problem that the contact area when the pickup roller contacts the sheet decreases, the sheet feeding force decreases, and reliable sheet conveyance becomes difficult. .
Further, in the case of roller conveyance, there is a problem that the sheet feeding force is remarkably reduced when paper dust adheres to the roller.
The present invention has been made by paying attention to the above-described problems of the prior art, and is capable of always stably feeding a sheet without being affected by paper curl or paper dust generated from a sheet such as recording paper. It is an object of the present invention to provide a sheet feeding apparatus and a sheet feeding apparatus having an inexpensive configuration capable of obtaining force.

In order to solve the above-described problems of the conventional techniques, the present invention has the following configuration.
That is, the present invention is a sheet feeding apparatus that feeds a sheet positioned at the outermost end of the sheets stacked on the sheet stacking unit to a predetermined feeding position, and a needle that can bite into the sheet A moving mechanism for moving the needle-like member in the sheet feeding direction, and an advancing / retreating mechanism for moving the needle-like member forward and backward with respect to the sheet positioned at the outermost end, and the needle-like member is disposed on the sheet stacking unit. The needle-like member is bitten into the sheet located at the outermost end by advancing toward the outer surface of the sheet located at the outermost end of the stacked sheets, and then the needle-like member is moved by the moving mechanism. The sheet is fed to a predetermined feeding position by moving in the sheet feeding direction.

  In the above invention, the advance / retreat mechanism can include an adjustment mechanism that adjusts the amount of feeding needle biting into the sheet.

  In the above invention, the moving mechanism includes a housing that can move between a predetermined standby position and a predetermined feeding position while holding the advance / retreat mechanism, and a housing driving means that moves the housing. The advance / retreat mechanism includes a holder movably held in the housing, a needle holder held by the holder, holder driving means for moving the holder forward and backward, and a needle holder for the sheet bundle. And an adjustment mechanism that adjusts the amount of the feed needle that bites into the sheet by adjusting the distance interval. As the adjusting mechanism, it is preferable that the amount of biting of the needle-shaped member can be adjusted within the thickness of the sheet, and further, the amount of biting of the needle-shaped member can be changed to a plurality of types by the adjusting mechanism. If it makes it, it becomes possible to apply to the sheet | seat of various thickness, and a highly versatile apparatus can be provided.

  The adjustment mechanism includes, for example, a cam that constantly contacts the needle holder and a cam drive motor that rotates the cam, and the cam drive motor changes a contact position between the cam and the needle holder. It is conceivable that the distance between the sheet located at the outermost end and the needle holder can be adjusted, and the cam has, for example, a large diameter portion and a small diameter portion, The amount of biting of the needle-like member into the sheet is increased by bringing the large-diameter portion and the needle holder into contact, and the amount of biting of the needle-like member into the sheet is reduced by bringing the small-diameter portion and the needle holder into contact with each other. It is conceivable that the configuration is as follows.

  In addition, it is desirable that the needle-like member in the above invention bites at a predetermined angle with respect to the outer surface of the outermost sheet stacked on the sheet stacking unit.

  Furthermore, in the above invention, when the sheet located at the outermost end where the needle-like member is bitten is moved by the moving mechanism, the sheet is attached to the sheet located at the outermost end to give a movement load. By separating the sheet located at the outermost edge and the sheet adhering to it by the moving load, it is possible to reliably feed only the sheet located at the outermost edge held by the needle-like member. It becomes.

  In addition, the present invention is an image forming apparatus that forms a predetermined image on a sheet fed by the sheet feeding apparatus.

  The present invention is also a sheet feeding method in which a sheet positioned at the outermost end of the sheets stacked on the sheet stacking unit is fed to a predetermined feeding position, and the sheet is bitten into the sheet. The needle-shaped member that is allowed to move toward the outer surface of the sheet located at the outermost end in the sheet bundle, so that the needle-shaped member is bitten into the sheet located at the outermost end, and then the movement The sheet is fed to a predetermined feeding position by moving the needle-like member in the sheet feeding direction by the member.

  According to the above invention, even when the stacked sheets are curled, since the sheets are held by the bite of the needle-like member, it is possible to hold the sheets with certainty and a good feeding force. Can be obtained. In addition, when the sheet is a recording sheet or the like, paper dust generated from the recording sheet may adhere to the needle-shaped member, but the sheet holding force of the needle-shaped member is not reduced thereby, and always Stable feeding can be performed.

  Furthermore, if an adjustment mechanism for adjusting the amount of biting of the needle-like member into the sheet is provided, the amount of biting of the needle-like member into the sheet can be adjusted according to the thickness of the sheet, so that a more stable sheet holding force can be obtained. In addition, there is no risk of penetrating the sheet and degrading the quality of the recorded matter.

  Further, if the needle-like member bites into the sheet at a predetermined angle with respect to the surface of the sheet, the amount of biting between the needle-like member and the sheet can be increased, and the sheet is removed from the needle-like member. Since it becomes difficult to come off, a more stable sheet feeding force can be obtained.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal side view showing an overall configuration of an ink jet printer to which the present invention is applied. The ink jet printer shown here constitutes a so-called card printer that performs recording on a relatively small card.
In FIG. 1, reference numeral 101 denotes a card printer. The card printer 101 includes an image forming unit 102 and a sheet feeding device 103 that separates and feeds sheets P to the image forming unit 102 one by one. .

Here, the image forming unit 102 is an ink jet recording head in which a large number of ink jet nozzles 104a are arranged in a length substantially equal to the image forming width of the sheet P along a direction (width direction) perpendicular to the sheet conveying direction indicated by the arrow X. A plurality of (here, six) 104 (hereinafter simply referred to as “recording heads”) are juxtaposed along the sheet conveying direction, and each recording is performed while supporting the sheet P conveyed from the sheet feeding device 103. A conveyance belt 105 that passes below the head 104 is provided.
The conveying belt 105 is stretched around a driving shaft 106, a driven pulley 107, and a driving pulley 108. When the driving shaft 106 is driven to rotate by the driving motor 109, the conveying belt 105 is rotated in the sheet conveying direction (X direction). ) To go around. Reference numeral 106 denotes a roller disposed at a position facing the driven pulley 107 via a conveyor belt 105.

  Further, as shown in FIG. 2, a plurality (four in this case) of the conveying belt 105 is wound around a driving shaft 106, a driven pulley 107, and a driving pulley 108. 1 and 2, reference numeral 110 denotes a plurality of spur units that rotate while pressing the sheet P conveyed by the conveyance belt 105 onto the conveyance belt 105, and each spur unit 110 is fixed to a rotation shaft 110a. The plurality of spurs 110b are configured. Reference numeral 111 denotes a spur cleaner unit provided to remove foreign matters such as paper dust adhering to each spur 110 b of each spur unit 110.

  In the image forming unit 102 configured as described above, the sheet P is conveyed at a constant speed by the revolving motion of the conveyance belt 105 while being sandwiched between the upper portion of the conveyance belt 105 and each spur unit 110, and each recording is performed therebetween. A color image is formed by applying inks of different colors, such as cyan, magenta, yellow, light cyan, light magenta, and black, from the nozzles 104a of the head 104.

  On the other hand, as shown in FIG. 1, a sheet feeding apparatus 103 that feeds sheets P one by one to the image forming unit 102 is installed at the side of the sheet supply port 102a of the image forming unit. It is configured.

  That is, the sheet feeding device 103 includes a sheet stacking table 112 that is a sheet stacking unit provided in the machine frame so as to be movable up and down, and one or a plurality of sheets that are above the sheet bundle stacked on the sheet stacking table 112. Of the sheet P picked up by the feeding mechanism 113, the separating means 114 for separating the sheets P picked up by the feeding mechanism 113 one by one, and the sheets P separated one by one by the separating means 114 A skew feeding correcting means 115 composed of a pair of rollers for correcting skew feeding, a curling means 116 comprising a pair of rollers for curling the sheet P whose skew feeding has been corrected by the skew feeding correcting means 115, and the like. Mainly prepared.

  Next, the configuration of each part of the sheet feeding apparatus 103 in the present embodiment will be described in more detail.

  The sheet stacking table 112 is held on the side of the lower frame 103a of the sheet feeding apparatus so as to be movable up and down by a predetermined lifting means 330 (see FIG. 9). Further, the sheet stacking table 112 is provided with sheet detecting means for determining whether or not sheets are stacked. This sheet detection means is configured such that when a sheet is present on the sheet stacking base 112, the sheet detection flag 122 abuts on the lower surface of the sheet and stops at the detection position by the sheet presence / absence detection sensor S2, and when there is no sheet, the sheet is detected. The detection flag is configured to move to a non-detection position by the sensor S2, and is detected by whether or not the sheet presence / absence detection sensor S2 detects the sheet detection flag 122 (whether it is on or off).

  Further, height detection means for detecting whether or not the sheets stacked on the sheet stacking table 112 are present at a height that can be fed is provided. The height detection means includes a paper surface detection flag 121 that is rotatably supported on the upper surface of the upper frame 103b, and a height detection sensor S1 that detects whether the paper surface detection flag 121 is present at a predetermined height. And is composed of. The height detection flag 121 is urged so that one end thereof is in contact with the uppermost sheet of the sheet bundle stacked on the sheet stacking table 112, and only when the sheet exists at a position suitable for supply. The sheet height sensor S1 detects the other end portion of the paper surface detection flag 121 and outputs a detection signal. When the sheet exists at a position unsuitable for supply, the detection signal is output from the sensor S1 by the movement of the paper surface detection flag 121. Not to be.

Further, the feeding mechanism 113 is configured as shown in FIGS.
In each figure, 302 is a housing held in the upper frame 103b. A pair of left and right arm portions 302a in which long holes 302b are formed are provided on both sides of the housing 302, and two housing support shafts 301a inserted into the long holes 302b formed in the arm portions 302a. , 301b is held movably in the front-rear direction (arrow X direction). A rack 304 is formed on the lower surface of the arm portion 302a, and a pinion 305 fixed to a rotating shaft 321 connected to a driving shaft that rotates by driving of the housing motor 320 is engaged with the rack 304. Yes. For this reason, the housing 302 moves back and forth together with the arm portions 301a and 301b by the forward rotation and the reverse rotation of the housing motor 320. The housing 113, the housing motor 320, the rack 305, and the like constitute a moving mechanism.

  A pickup mechanism 330 is provided in the housing 302 for picking up sheets from the sheet bundle stacked on the sheet stacking table 112. The pickup mechanism 330 includes a holder 306 that is rotatably supported on both sides of a rear portion by a fulcrum shaft 308 supported in the housing 302. The holder 306 is always suspended at a position where the upper surface is substantially horizontal by the elastic force of the two housing springs 307 hooked between the upper surface portion and the inner surface of the housing. In addition, a pair of shaft insertion portions 306a and 306a provided opposite to each other protrude from the upper surface of the upper portion of the housing 302, and the elongated holes 306b and 306b formed in the shaft insertion portions 306a and 306a A connecting shaft 303b protruding from a plunger 303a of a solenoid 303 (holder driving means) fixed to the housing is inserted.

  The holder 306 supports a feeding needle unit 309. The feeding needle unit 309 is provided with a housing 311. As shown in FIG. 4, the housing 311 has stoppers 311 a projecting from both left and right sides thereof loosely fitted in long holes 306 a formed on both left and right sides of the holder 306, and is long with respect to the holder 306. It can move up and down within the range of the hole 306a. A needle unit spring 310 is provided between the upper outer surface of the housing 309 a and the upper inner surface of the holder 306, and the housing 311 is always stopped by the pressing force of the needle unit spring 310. Is held at a position (downward position) that contacts the lower end of the long hole. Further, a needle base (needle holder) 313 formed by projecting two feeding needles (needle-like members) 312 on the lower surface is suspended by four base springs 315 in the housing 311. . In this embodiment, the feeding needles 312 and 312 are held with their sharp tip portions inclined at a predetermined angle toward the left and right outer sides, and the tip portions are formed on the bottom surface of the housing 311. It penetrates the needle insertion hole 311b and protrudes outward.

  Further, a cam shaft 316c is rotatably supported in the housing 311. A pair of left and right cams 316 having the same shape are supported on the cam shaft 316c with the same rotational phase at a predetermined interval. The outer peripheral surfaces (cam surfaces) of both cams are always in pressure contact with the upper surface of the needle base 313 by the urging force of the needle base spring 315. The cam shaft 316c is connected to a cam motor 318 held in the housing 311 via a coupling 317. When the cam motor 318 rotates, the cam shaft 316c and the cam 316 are connected to the upper surface of the needle base 313. It is designed to rotate while being pressed against. As shown in FIG. 3, the outer peripheral surface (cam surface) of the cam 316 in this embodiment has a small diameter at which the distance between the cam shaft 316a and the large diameter portion 316a where the distance between the cam shaft 316a and the cam shaft 316a is maximum. Part 316b. As shown in FIG. 5, when the large-diameter portion 316a of the cam surface is in contact with the needle base 313, the feeding needle 312 is pushed down together with the needle base 313 to protrude from the needle insertion hole 309b. When the amount is the maximum (T2) (see FIG. 6) and the small diameter portion of the cam surface is in contact with the needle base 313 as shown in FIG. 7, the amount of protrusion of the feeding needle 312 from the needle insertion hole 309 is It becomes the minimum (T1) (see FIG. 8). Thus, in this embodiment, the amount of protrusion of the feeding needle 312 from the needle insertion hole 311b can be changed in two stages by rotating the cam 316. Further, the protruding amount of the feeding needle 312 is detected by a base detection flag 319 provided at one end of the needle base 313 and a cam sensor S6 for detecting the presence or absence thereof. That is, when the cam sensor S6 detects the base detection flag 319, the protruding amount of the feeding needle 312 becomes large, and when the cam sensor S6 does not detect the base detecting flag 319, the protruding amount of the feeding needle 312 is small. Become. The holder 306, the solenoid 303, and the paper feed needle unit 309 constitute an advance / retreat mechanism for advancing and retreating the feeding needle 312 with respect to the sheet P1 positioned at the uppermost position of the sheet bundle P. The cam 316 and the cam motor 318 constitute a preparation mechanism that adjusts the amount of biting of the feeding needle 312 with respect to the sheet P1.

Next, the configuration of the control system 80 of the card printer 101 to which the sheet feeding apparatus in this embodiment is applied will be described with reference to FIG.
In FIG. 9, the control system 80 of the card printer 101 in this embodiment has a CPU 81 as a control means for controlling each part described later in accordance with a program corresponding to the flow shown in FIG. The CPU 81 has a program ROM 83, a work RAM 84 having a work area for storing data in the data processing by the CPU 81, and an interface (I / F) for connecting the host computer 200 and the CPU 81. 82, an input port 85, an output port 88, a recording control circuit 86 for controlling the recording head 104 of the image forming unit 102, and the like are connected. The above-described sensors S1 to S7 are connected to the input port 85, and the motors 109, 318, and 320 of the card printer 101, the solenoid 303, and the skew correction means 115 are connected to the output port 88. A driver circuit 87 for driving the elevating means 330 and the like is connected.

Based on the above configuration, the operation of the sheet feeding apparatus 103 in the present embodiment will be described with reference to the flowchart of FIG. 14 and the operation explanatory diagrams of FIGS.
In a standby state before a recording operation start command is input from the host computer 200 or the like, the feeding mechanism 113 of the sheet feeding apparatus 103 is in a state as shown in FIG. That is, the housing 302 is in the most retracted state (rightward in FIG. 3), the solenoid 303 is in a non-driven state, the plunger 303a protrudes backward, and the holder 306 is substantially pressed by the elastic force of the holder spring 307. It is held in a horizontal state. Further, the small diameter portion 316b of the cam 316 of the conveying needle unit 309 is in contact with the upper surface of the needle base 313, and the feeding needle 312 is held in the raised state. For this reason, the feeding needle 312 is held at a position away from the sheet P1 positioned at the top of the sheet bundle P stacked on the sheet stacking table 112. Note that the uppermost sheet P1 of the sheet bundle P stacked on the sheet stacking table 112 is always maintained at a constant height regardless of the sheet stacking amount. This is performed by the CPU 81 controlling the lifting mechanism in accordance with a signal from the seat height detection sensor S1.

  Here, when a feeding command is input from the host computer to the sheet feeding apparatus 103, an image forming operation is instructed (step S1), and the CPU 81 follows the control program stored in the program ROM 83. The paper feed mechanism 113 of the feeding device 103 is controlled as follows.

  First, the protrusion amount of the feeding needle 312 to be set is determined based on the sheet thickness information input in advance by the host computer 200 (step S2). The protrusion amount is determined by comparing the set sheet thickness with the protrusion amounts T1 and T2. That is, it determines by selecting the protrusion amount which becomes less than sheet thickness among each protrusion amount T1, T2. However, if both protrusion amounts are less than the sheet thickness (sheet thickness> (T1 and T2)), it is determined by selecting a larger amount (T2) to puncture the sheet. Also, if both protrusion amounts T1 and T2 exceed the sheet thickness (when sheet thickness <(T1 and T2)), an error occurs, an error signal is sent to the host computer, and an error display is displayed. This is done (step S3).

  Thus, when T1 or T2 is selected as the protrusion amount of the feeding needle, the cam motor 318 is driven or stopped as it is by the signal of the cam sensor S6, and a predetermined protrusion amount T1 or T2 is set (step S4).

  Thereafter, the skew feeding correction member 115 starts to be driven and the solenoid 303 is driven (ON), and the plunger 303a is pulled inward (leftward in FIG. 3) (step S5). As a result, the holder 306 rotates around the fulcrum 308 and the feeding needle unit 309 is pressed by the needle unit spring 310 against the uppermost sheet P1 in the sheet bundle P stacked on the sheet stacking table 112. The feeding needle 312 bites into the sheet P1 (see FIG. 10).

  Next, the housing motor 320 is driven (step S6), the pinion 305 starts to rotate counterclockwise in the figure, and the housing 302 starts to move forward (leftward in the figure). At that time, the sheet P2 adhering to the uppermost sheet P1 due to static electricity between the sheets is separated from the uppermost sheet P1 by being applied with a conveying load by contact with the separating unit 114, and only the sheet P1 is dropped. Is conveyed (see FIG. 11).

  Further, when the housing 302 moves forward and the housing sensor S4 detects the tip of the arm portion 302a and is turned on (step S7), the driving of the housing motor 320 is stopped according to the detection signal, and the pinion 305 is turned on. The rotation stops (step S8). At this time, the sheet P1 has been delivered to the skew feeding correction means 115 (see FIG. 12). Next, the energization of the solenoid 303 is cut off (OFF) (step S9), and the feeding needle unit 309 is retracted upward by the urging force of the holder spring 307 and is separated from the sheet P1 (see FIG. 13).

  Thereafter, the housing motor 320 rotates in the reverse direction, and the pinion 305 rotates in the reverse direction (step S10). As a result, the housing moves rearward (rightward in the figure), and when it reaches the standby position detected by the housing sensor S3 (step S11), the housing motor 320 stops its rotation (step S12), and the pinion The rotation of 305 stops. As a result, the state shown in FIG. 3 is restored. Note that the sheet P1 delivered to the skew feeding correcting unit 115 is conveyed by the conveying belt 109 of the image forming unit 102 through the curling unit 116, and after the image is formed by the recording head 104, the sheet discharge tray 120. The paper is discharged.

  Thereafter, it is determined whether or not a sheet is present on the sheet stacking table 112 based on whether or not the sheet detection sensor S2 is ON (step S13). Is prohibited, and a no-sheet signal is sent to the host computer 200 (step S14). If it is determined in step S13 that a sheet is present on the sheet stacking table 11, it is further determined whether or not there is a feeding command (step S15). The paper feeding operation is stopped (step S16). If there is a feeding command, it is determined whether or not the sheet thickness has been changed (step S17). If the sheet thickness has not been changed as in the case of continuous recording, skew correction is performed. When the skew feeding sensor S7 provided downstream of the means 115 detects the trailing edge of the sheet P1, the operations after step S5 are repeated again. Further, when the sheet thickness is changed, in steps S2 and S3, a projection amount corresponding to the sheet thickness is set, and thereafter the same operation is performed.

(Other embodiments)
In the above embodiment, the case where the two feeding needles 312 protruding from the needle base 313 are inclined toward the outside by a predetermined angle (θ degrees) as shown in FIG. 6 is taken as an example. As described above, the two feeding needles 312 may be inclined inward by a predetermined angle (θ degrees) as shown in FIG. 15, and in this case as well, as in the above embodiment. In addition, since the amount of biting into the sheet can be increased, good holding force can be obtained, and stable feeding can be performed.

  Further, the present invention is not limited to the above embodiment, and the number, arrangement, angle, and the like of the feeding needles can be changed as appropriate. For example, the number of feeding needles may be one, or two or more, and the feeding needles may be arranged at positions shifted in the front-rear direction. May be inclined in the front-rear direction. Furthermore, the mechanism for moving the feeding needle toward and away from the sheet bundle, the mechanism for moving the feeding needle in the sheet conveyance direction, etc. are not limited to those shown in the above embodiment, and other configurations are used. It is also possible. For example, in the above embodiment, the feeding needle 312 is moved up and down together with the transport unit 309 by turning the holder 306 about the fulcrum 308. However, the holder 306 is held linearly movable relative to the housing. It is also possible to raise and lower the holder linearly by moving the plunger of the solenoid 303 up and down. Further, it is possible to use a motor or the like without using a solenoid as a drive source for raising and lowering the feeding needle, and any mechanism can be applied as long as it can raise and lower the feeding needle.

  Furthermore, the present invention is not limited to the one that sequentially feeds the uppermost sheet of the sheet bundle, but can also be applied to one that sequentially feeds the sheet positioned at the lowest (outermost end) of the sheet bundle. In this case, the feeding needle can be moved forward and backward with respect to the lowermost sheet exposed from the opening formed in the mounting table.

  In the above-described embodiment, the case where the sheet feeding apparatus according to the present invention is applied to an image forming apparatus such as a card printer has been described as an example. However, the sheet feeding apparatus according to the present invention is a stacked sheet. The present invention can be applied to all processes such as feeding sheets from a bundle, and the application range is not limited to the image forming apparatus.

1 is a longitudinal side view showing a schematic configuration of a card printer which is an example of an image forming apparatus according to an embodiment of the present invention. It is a top view which shows the structure of the card printer shown in FIG. FIG. 3 is a partially longitudinal side view for explaining a configuration of a feeding mechanism in the sheet feeding device of the card printer shown in FIG. 1. FIG. 4 is a partially longitudinal front view for explaining the configuration of the feeding mechanism shown in FIG. 3. FIG. 5 is a partially longitudinal side view for explaining the configuration of the feeding needle unit in the state shown in FIG. 4 and shows a state in which the feeding needle is set to a large protruding amount T1. FIG. 6 is a partially longitudinal front view for explaining the configuration of the feeding needle unit in the state shown in FIG. 5. FIG. 7 is a partially longitudinal side view for explaining the configuration of the feeding needle unit in the state shown in FIG. 6, and shows a state where the feeding needle is set to a small protrusion amount T <b> 1. FIG. 8 is a partially longitudinal front view for explaining the configuration of the feeding needle unit shown in FIG. 7. It is a block diagram which shows schematic structure of the control system of the card printer in embodiment of this invention. FIG. 2 is a schematic side view illustrating a state in which the feeding needle unit of the feeding mechanism is lowered to the uppermost sheet and the feeding needle is inserted into the sheet in the sheet feeding apparatus illustrated in FIG. 1. FIG. 11 is a schematic side view showing a state in which the housing of the feeding needle unit moves forward from the state shown in FIG. 10 and separates the sheet attached to the uppermost sheet. FIG. 12 is a schematic side view showing a state where the housing further moves forward from the state shown in FIG. 11, reaches the detection by the housing sensor S <b> 4, and passes the sheet to the skew feeding correction unit. FIG. 13 is a schematic side view showing a state where the feeding needle unit is lifted from the state shown in FIG. 12 and the feeding needle is separated from the sheet. 3 is a flowchart showing sheet feeding operation of the card printer shown in FIG. 1. It is a partially longitudinal front view which shows the structure of the feeding needle in other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Card printer 102 Image forming part 103 Sheet feeding apparatus 104 Inkjet recording head 105 Conveying belt 106 Driving shaft 107 Driven pulley 108 Driving pulley 109 Conveying motor 110 Spur unit 111 Spur cleaner unit 112 Sheet stacking table 113 Feeding mechanism 114 Separating means 115 Skew correction means 116 Curling means 117 Roller 118 Pinch roller 119 Paper discharge spur 120 Paper discharge tray 121 Paper surface detection flag 122 Sheet presence / absence detection flag 301 Housing support shaft 302 Housing 303 Solenoid 304 Rack 305 Gear 306 Holder 307 Holder spring 308 Support shaft 309 Feeding needle unit 310 Needle unit spring 311 Stopper 312 Feeding needle 313 Needle base 314 Feeding needle frame 3 5 needle Besubane 316 cam 317 coupling 318 cam motor 319 based detection flag S1 sheet height detection sensor S2 sheet presence detecting sensor S3 housing sensor S4 housing sensor S5 TOF sensor S6 cam sensor S7 skew sensor

Claims (11)

A sheet feeding device that feeds a sheet positioned at the outermost end of the sheets stacked on the sheet stacking unit to a predetermined feeding position,
A moving mechanism for moving a needle-like member capable of biting into the sheet in the sheet feeding direction;
An advancing and retreating mechanism for advancing and retreating the needle-like member with respect to the sheet located at the outermost end,
The needle-like member is bitten into the sheet located at the outermost end by advancing the needle-like member toward the outer surface of the sheet located at the outermost end of the sheets stacked on the sheet stacking unit. Then, the sheet feeding device is characterized in that the sheet is fed to a predetermined feeding position by moving the needle-like member in the sheet feeding direction by the moving mechanism.   The sheet feeding apparatus according to claim 1, wherein the advance / retreat mechanism includes an adjustment mechanism that adjusts a biting amount of the feeding needle with respect to the sheet. The moving mechanism includes a housing that can move between a predetermined standby position and a predetermined feeding position while holding the advance / retreat mechanism, and a drive unit that moves the housing,
The advance / retreat mechanism includes a holder movably held in the housing, a needle holder held by the holder, a driving means for moving the holder forward and backward, and a distance between the needle holder and the sheet bundle. The sheet feeding apparatus according to claim 1, further comprising an adjusting mechanism that adjusts an amount of biting of the feeding needle with respect to the sheet by adjusting an interval.   The sheet feeding apparatus according to any one of claims 1 to 3, wherein the adjusting mechanism is capable of adjusting a biting amount of the needle-like member within a thickness of the sheet.   The sheet feeding apparatus according to any one of claims 1 to 4, wherein the adjustment mechanism can change the amount of biting of the needle-like member into a plurality of types.   The adjustment mechanism includes a cam that constantly contacts the needle holder and a cam drive motor that rotates the cam, and the cam drive motor changes the contact position between the cam and the needle holder so that the outermost 6. The sheet feeding apparatus according to claim 3, wherein a distance between the sheet positioned at an end and the needle holder can be adjusted.   The cam has a large-diameter portion and a small-diameter portion, and when the large-diameter portion and the needle holder are brought into contact with each other, the amount of biting of the needle-like member into the sheet is increased, and the small-diameter portion and the needle holder are The sheet feeding device according to claim 6, wherein the amount of biting of the needle-like member into the sheet is reduced by contacting the sheet-like member.   The sheet feeding device according to claim 1, wherein the needle-like member bites at a predetermined angle with respect to an outer surface of the outermost sheet stacked on the sheet stacking unit. .   When the moving mechanism moves the sheet positioned at the outermost end where the needle-like member is bitten, the moving load is applied to the sheet attached to the sheet positioned at the outermost end, and the moving load causes the maximum load. 9. A sheet feeding apparatus according to claim 1, wherein a sheet positioned at the outer end and a sheet adhering to the sheet are separated from each other.   An image forming apparatus, wherein a predetermined image is formed on a sheet fed by the sheet feeding device according to claim 1. A sheet feeding method in which a sheet positioned at the outermost end of the sheets stacked on the sheet stacking unit is fed to a predetermined feeding position,
The needle-like member that can bite into the sheet is advanced toward the outer surface of the sheet located at the outermost end in the sheet bundle, so that the needle-like member is bitten into the sheet located at the outermost end. Thereafter, the sheet is fed to a predetermined feeding position by moving the needle-like member in the sheet feeding direction by the moving member.

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