JP2006001699A - Sheet feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To previously eliminate close contact of a sheet regardless of the type of a sheet. <P>SOLUTION: When OHP sheets 200 different in thickness between a mount part 202 and a transparent part 204 are stacked and accommodated in a sheet feed tray 52, a difference in height is caused between the mount part 202 and the transparent part 204 of the OHP sheet 200. Accordingly, an air blowout part 70 is lowered to the optimum air blowout port 70 position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet feeding apparatus.

  2. Description of the Related Art Conventionally, in image forming apparatuses such as printers and copying machines, cut sheets (copy sheets) that enable continuous paper feeding are generally used as media on which images are formed. Conventionally, these sheets (paper) have been used plain paper or high-quality paper designated by the copier manufacturer. These plain papers and high-quality papers have low surface smoothness, so the adhesion between the sheets is low, and even when sheets are fed one by one from the paper stacking unit such as a paper feed tray, multiple sheets are in close contact. It was relatively easy to prevent so-called double feeding.

  However, in recent years, with the diversification of recording media, it has been required to transport a wide variety of sheets including sheets with high surface smoothness. In particular, coated paper with increased whiteness and gloss with the development of color technology (coated paper, composite sheet with a coating color, a type of paint, for the purpose of improving printability on both sides or one side of the sheet) ), And a medium other than paper, such as a film sheet and tracing paper, has a high demand for conveyance in the same model. This coated paper, film sheet, tracing paper, etc. have high surface smoothness, so the adhesion between the sheets is strong, and as a result it is difficult to prevent double feeding, so special measures are required for sheet supply Become.

  For example, taking coated paper as an example, the coated paper increases in quality as the quality of the coated paper increases, the white glossiness, which is an optical property, increases, and the surface unevenness decreases and the surface smoothness increases. On the other hand, when the surface smoothness becomes high, the interval between the papers when in contact with each other becomes narrower, the negative pressure generated in a state where air does not pass through the interval is maintained, and the adhesion between the coated papers becomes stronger. . In particular, when the sheets are stacked in a high humidity environment, the coated papers are adsorbed and the degree of adhesion becomes higher. Film sheets, tracing paper, and the like are also similar to coated paper because they have high surface smoothness and high sheet-to-sheet adhesion.

When such smooth sheets with strong adhesion between sheets are fed one by one from the paper feed tray on which the sheets are stacked, they are separated and conveyed one by one with the normal plain paper feeding device. It becomes very difficult to do. In particular, a sheet feeding device using a pull-in roll that pulls a sheet by rotating in contact with the surface of the sheet with a predetermined pressing force, and a system that presses and separates a supply roll and a separation roll at a constant pressure when the sheet is rolled. Then, when the smooth sheet is separated and conveyed, a pressing force that is about 30 times that of normal plain paper is required. As a method for eliminating such close contact with the smooth sheet in advance, a technique for blowing air from the side surface of the stacked sheets has been proposed (for example, see Patent Document 1).
JP 2003-63675 A

  Now, some sheets have a non-uniform thickness. For example, as shown in FIG. 10, an OHP sheet 200 having a mount portion 202 for gripping by hand at the front end portion is thick, the transparent portion 204 other than the mount portion 202 is thin, and the thickness is uniform. No.

  When the OHP sheets 200 having different thicknesses between the mount portion 202 and the transparent portion 204 are stacked and stored in the sheet supply tray 552 as shown in FIG. 11, the mount portion 202 and the transparent portion 204 of the OHP sheet 200 A difference in height occurs. (Note that both FIG. 10 and FIG. 11 are extremely shown for the sake of clarity). Therefore, in the case of the OHP sheet 200 having a non-uniform thickness, the air blown from the air outlet 570 does not hit the OHP sheet 200 according to the method described in Japanese Patent Laid-Open No. 2003-63675. For this reason, there is a problem that the adhesion of the OHP sheet 200 cannot be eliminated in advance.

  The present invention has been made to solve the above-described problems, and an object thereof is to eliminate adhesion of a sheet in advance regardless of the type of the sheet.

  The sheet supply apparatus according to claim 1, wherein a storage unit that stacks and stores sheets, a feeding unit that supplies the sheet stored in the storage unit to a next process, and the storage unit that stores the sheet are stored in the storage unit. An air spraying means for blowing air to the sheet, a spray position moving means for moving the air spraying position of the air spraying means in the stacking direction of the sheets, and the spraying defined for each type of the sheet In a sheet supply apparatus including a storage unit that stores a reference position of a position and a sheet type selection unit that selects the type of the sheet, the selection result of the sheet type selection unit and the reference position stored in the storage unit And control means for controlling the spray position moving means based on the above.

  In the sheet supply apparatus according to the first aspect, air is blown by the air blowing means to the sheets stacked and accommodated in the accommodating portion, and the adhesion between the sheets is released. Then, the sheet is supplied to the next process by the feeding means. As described above, since the close contact between the sheets is solved in advance, for example, sheet supply failure such as double feeding is prevented.

  Further, the control means controls the spray position moving means based on the selection result of the sheet type selection means and the reference position of the air spray position of the air spray means stored in the storage means. Therefore, air is blown to the optimum position for each sheet type. Accordingly, the close contact between the sheets is solved in advance regardless of the type of the sheet.

  The sheet supply apparatus according to claim 2, wherein the storage unit stores and stacks the sheets, the feeding unit that supplies the sheets stored in the storage unit to the next process, and the storage unit stores the sheets. Air blowing means for blowing air to the sheet, air blowing position moving means for moving the air blowing position of the air blowing means with respect to the stacking direction of the sheets, and the above defined for each type of the sheet In a sheet supply apparatus including a storage unit that stores a reference position of a spray position and a sheet type selection unit that selects the sheet type, a stacking amount input unit that inputs a stacking amount of the sheet stored in the storage unit. The spray position movement based on the load amount input to the load amount input means, the selection result of the sheet type selection means, and the reference position stored in the storage means It is characterized in that it comprises a control means for controlling the stage.

  According to a second aspect of the present invention, there is provided the sheet supply apparatus, wherein the control unit is configured to perform spraying based on the input result of the sheet stacking amount of the stacking amount input unit, the selection result of the sheet type selection unit, and the reference position stored in the storage unit. The position moving means is controlled. Therefore, air is blown to the optimum position according to the sheet stacking amount. Accordingly, the close contact between the sheets is solved in advance regardless of the sheet stacking amount.

  The sheet supply apparatus according to claim 3, wherein the storage unit stores and stacks the sheets, the feeding unit that supplies the sheet stored in the storage unit to the next process, and the storage unit stores the sheet. Air blowing means for blowing air to the sheet, air blowing position moving means for moving the air blowing position of the air blowing means with respect to the stacking direction of the sheets, and the above defined for each type of the sheet In a sheet supply apparatus including a storage unit that stores a reference position of a spray position and a sheet type selection unit that selects the sheet type, a stack amount detection unit that detects a stack amount of the sheets stored in the storage unit And controlling the spray position moving means based on the detection result of the load amount detection means, the selection result of the sheet type selection means, and the reference position stored in the storage means It is characterized in that it comprises a control unit that.

  According to a third aspect of the present invention, there is provided the sheet supply apparatus, wherein the control means includes the spray position moving means based on the detection result of the stacking amount detection means, the selection result of the sheet type selection means, and the reference position stored in the storage means. I have control. Therefore, air is blown to the optimum position according to the sheet stacking amount. Accordingly, the close contact between the sheets is solved in advance regardless of the sheet stacking amount.

  The sheet supply apparatus according to claim 4, wherein a storage unit that stacks and stores sheets, a feeding unit that supplies the sheets stored in the storage unit to the next process, and the storage unit that stores the sheets are stored in the storage unit. An air spraying means for blowing air to the sheet, a spray position moving means for moving the air spraying position of the air spraying means in the stacking direction of the sheets, and the spraying defined for each type of the sheet A sheet supply device comprising a storage unit that stores a reference position of a position and a sheet type selection unit that selects the type of the sheet, and a remaining sheet amount detection that detects the remaining sheet amount of the sheet stored in the storage unit. And the spray position movement based on the detection result of the sheet remaining amount detection means, the selection result of the sheet type selection means, and the reference position stored in the storage means It is characterized in that it comprises a control means for controlling the stage.

  According to a fourth aspect of the present invention, there is provided the sheet feeding apparatus according to the fourth aspect, wherein the control means is based on the detection result of the remaining sheet quantity detection means, the selection result of the sheet type selection means, and the reference position stored in the storage means. To control. Therefore, even if the optimum air blowing position on the sheet changes due to the change in the remaining sheet amount, the optimum air blowing position is controlled regardless of the remaining sheet amount because the air blowing position is controlled according to the change. Position.

  The sheet supply apparatus according to claim 5, wherein a storage unit that stacks and stores sheets, a feeding unit that supplies the sheet stored in the storage unit to a next process, and the storage unit that stores the sheet are stored in the storage unit. An air spraying means for blowing air to the sheet, a spray position moving means for moving the air spraying position of the air spraying means in the stacking direction of the sheets, and the spraying defined for each type of the sheet In a sheet supply apparatus including a storage unit that stores a reference position of a position, and a sheet type selection unit that selects the type of the sheet, a stacking amount input unit that inputs a stacking amount of the sheet stored in the storage unit, A sheet remaining amount detecting unit that detects the remaining amount of the sheet stored in the storage unit, and an input result input to the stacking amount input unit and detection of the sheet remaining amount detecting unit And fruit, and the selection result of the sheet type selecting means, the reference position stored in the storage means, characterized in that it comprises a control means for controlling the blowing position moving means based on.

  The sheet supply apparatus according to claim 5 is based on the input result input to the stacking amount input unit, the detection result of the remaining sheet amount detection unit, the selection result of the sheet type selection unit, and the reference position stored in the storage unit. The control means controls the spray position moving means. Therefore, since the air blowing position is controlled according to the change in the sheet stacking amount and the remaining sheet amount, the optimum air blowing position is obtained regardless of the sheet stacking amount and the remaining sheet amount.

  The sheet supply apparatus according to claim 6, wherein a storage unit that stacks and stores sheets, a feeding unit that supplies the sheet stored in the storage unit to a next process, and the storage unit that stores the sheet are stored in the storage unit. An air spraying means for blowing air to the sheet, a spray position moving means for moving the air spraying position of the air spraying means in the stacking direction of the sheets, and the spraying defined for each type of the sheet A storage unit that stores a reference position of the position; and a sheet supply apparatus that includes a sheet type selection unit that selects the type of the sheet, and a stack amount detection unit that detects a stack amount of the sheets stored in the storage unit. Sheet remaining amount detecting means for detecting the remaining amount of the sheet accommodated in the accommodating portion, the detection result of the stack amount detecting means, the detection result of the remaining sheet amount detecting means, And selection result of the serial sheet type selecting means is characterized by comprising said reference position stored in the storage means, a control means for controlling the blowing position moving means based on.

  The sheet supply apparatus according to claim 6 is controlled based on the detection result of the stacking amount detection unit, the detection result of the remaining sheet amount detection unit, the selection result of the sheet type selection unit, and the reference position stored in the storage unit. The means controls the spray position moving means. Therefore, since the air blowing position is controlled according to the change in the sheet stacking amount and the remaining sheet amount, the optimum air blowing position is obtained regardless of the sheet stacking amount and the remaining sheet amount.

  The sheet supply apparatus according to claim 7, in the configuration according to claim 3 or claim 6, includes a top sheet position detection unit that detects the position of the uppermost sheet of the sheet stored in the storage unit. A lift-up unit that lifts up the seat stored in the storage unit; and a lift-up control unit that controls a lift-up amount of the lift-up unit according to a detection result of the top sheet detection unit. The stacking amount detection means detects the stacking amount of the sheets based on the lift-up amount.

  The sheet supply apparatus according to claim 7, wherein the top sheet position detection unit detects the position of the uppermost sheet of the sheets stored in the storage unit, and the lift-up control unit detects the lift of the lift-up unit based on the detection result. The up amount is controlled, and the sheet stacking amount is detected based on the lift up amount. The control unit controls the spray position moving unit based on the detection result (lift amount) of the sheet stacking amount. Therefore, air is blown to the optimum position according to the sheet stacking amount. Accordingly, the close contact between the sheets is solved in advance regardless of the sheet stacking amount.

  According to an eighth aspect of the present invention, in the configuration according to any one of the first to seventh aspects, the control means moves the spray position up and down at a predetermined cycle.

  In the sheet supply apparatus according to the eighth aspect, since the control unit moves the spray position up and down at a predetermined cycle, the air is sequentially flowed from the upper stacked sheet to the lower sheet and from the lower sheet to the upper sheet. Is sprayed. Therefore, the adhesion between the stacked sheets can be more effectively solved. For this reason, for example, it is possible to prevent the upper sheet from being floated while being in a bundle shape from the weakly adhered portion, so that double feeding or the like can be more reliably prevented.

  As described above, according to the present invention, air is blown at an optimum position for each sheet type, so that the close contact between the sheets can be solved in advance regardless of the type of the sheet.

  Hereinafter, an embodiment of an image forming apparatus including a sheet supply apparatus according to the present invention will be described with reference to the drawings. A known electrophotographic process is used as an image forming method of the image forming apparatus.

  First, the configuration of the image forming apparatus 10 and an outline of image formation will be described first, and then the main part of the present invention will be described. In addition, as the sheet P on which an image is formed, a sheet having a smooth surface such as plain paper, coated paper having a surface coated to obtain whiteness and gloss, and the like are shown in FIG. An OHP sheet 200 or the like is used.

  As shown in FIG. 1, the image forming apparatus 10 includes a control unit 24 that controls the entire image forming apparatus 10 and stores various types of information. An operation panel 11 is provided on the upper part of the apparatus. When the user operates the operation panel 11, the control unit 24 performs control according to the operation content.

  Further, the image forming apparatus 10 includes an image forming unit 12 that forms an image using a known electrophotographic process.

  The image forming unit 12 is provided with a photosensitive drum 14, and a charger 16, a developing device 18, and a cleaner 20 are disposed on the photosensitive drum 14 along the circumferential direction. Further, an image writing device 22 that irradiates the surface of the photosensitive drum 14 between the charger 16 and the developing device 18 with the laser light L is provided. Further, a transfer roller 34 is provided on the opposite side of the photosensitive drum 14 from the image writing device 22.

  The image writing device 22 is connected to the control unit 24, and the control unit 24 is connected to the receiving unit 26. An external device such as an image reading device 28 or a personal computer 30 is connected to the receiving unit 26 via a communication line 32, and image information is sent from the image reading device 28, the personal computer 30, or the like. The image information is sent from the receiving unit 26 to the control unit 24, and the control unit 24 controls the image writing device 22 based on the image information and irradiates the laser beam L.

  The surface of the photosensitive drum 14 is charged to a predetermined potential by the charger 16. Then, the laser beam L is irradiated from the image writing device 22 to expose the surface of the photosensitive drum 14 to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 18 and a toner image is formed on the surface of the photosensitive drum 14.

  A sheet P is conveyed from a sheet feeding unit 40 to be described later to a nip portion between the photosensitive drum 14 and the transfer roller 34 via a sheet conveying unit 44 having a plurality of conveying rollers 46. Then, the toner image on the photosensitive drum 14 is transferred to the sheet P by the transfer roller 34 and sent to the fixing device 36 installed on the downstream side in the transport direction, and the toner image is fixed on the sheet P. A pair of discharge rollers 38 is provided on the downstream side in the conveyance direction of the fixing device 36, and the sheet P on which the toner image is fixed is discharged to the discharge tray 39 by the discharge rollers 38.

  The toner remaining on the surface of the photosensitive drum 14 without being transferred to the sheet P is collected by the cleaner 20.

  Below the image forming apparatus 10, a sheet feeding unit 40 in which a plurality (four in the present embodiment) of sheet feeding devices 50 are arranged vertically is disposed. Each sheet supply device 50 is provided with a sheet supply tray 52 on which sheets P are stacked and stored. A bottom plate 120 (see FIG. 6) is provided inside these sheet supply trays 52, and is moved up and down by a drive mechanism (not shown). As the bottom plate 120 is moved up and down, the stacked sheets P are raised and lowered.

  As shown in FIG. 3, on the upstream side of the sheet feeding direction S of the sheet P in the sheet supply tray 52, an end guide 64 that is configured to be movable depending on the size of the sheet P and regulates the rear end surface of the sheet P is provided. Yes. Further, a side fixed guide 66 is disposed on one side surface in a direction orthogonal to the sheet feeding direction S. On the other side facing the side fixed guide 66, a side movable guide 68 configured to be movable depending on the size of the sheet P is disposed.

  As shown in FIGS. 2 and 3, on the downstream side in the feeding direction S of the sheet supply tray 52, the sheet P is sequentially passed through the sheet conveying unit 44 to the nip portion between the photosensitive drum 14 and the transfer roller 34 ( 1 is provided. The feeding mechanism 90 is provided with a nudger roller (retraction roller) 56 that is brought into frictional contact with the upper surface of the uppermost top sheet TP of the stacked sheets P. As shown in FIG. 5, the nudger roller 56 is movable between a delivery position A that is sent out in contact with the upper surface of the top sheet TP and a standby position B that is retracted upward.

  As shown in FIGS. 2 and 3, a feed roller (conveying roller) 58 and a retard roller (rolling roller) 60 pressed by the feed roller 58 are provided downstream of the nudger roller 56 in the feeding direction S. ing.

  The nudger roller 56, the feed roller 58, and the retard roller 60 are configured to perform the conveying action of the sheet P by making frictional contact with the sheet P. Specifically, the sheet P fed from the nudger roller 56 is conveyed one by one by the feed roller 58 and the retard roller 60 and conveyed to the downstream portion.

  As shown in FIG. 4, the retard roller 60 is pressed against the feed roller 58 with a weak pressure by a spring 96 via a support 94 having a pivot 92 as a rotation center. The retard roller 60 is connected to a first gear 100 that rotates and a fixed second gear 102 via a torque limiter 98 provided on the shaft 60A. A driving force from a feed motor (not shown) is transmitted to the second gear 102, and the retard roller 60 receives a driving force in the arrow direction.

  The nudger roller 56 is configured to rotate via an arm 82 with the shaft 58A of the feed roller 58 as a rotation center, and rotates in conjunction with the drive of the feed roller 58 by a gear group 84. Further, when the planer 86A enters and exits due to the operation of the solenoid 86 that operates in response to a drive signal from the control unit 24 (see FIG. 1), the link 88 rotates around the shaft 89 to move the protrusion 88A up and down. A pin 82A of the arm 82 is placed on the projecting portion 88A. When the pin 82A moves up and down in conjunction with the projecting portion 88A, the arm 82 rotates up and down and the nudger roller 56 is sent to the standby position B. Move to position A (see FIG. 5). That is, when the protruding portion 88A of the link 88 is lowered, the nudger roller 56 is lowered to the delivery position A in contact with the upper surface of the top sheet TP, and the top sheet TP is sent out by being rotationally driven with a predetermined pressing force. .

  Further, the movement of the arm 82 (the nudger roller 56) at the delivery position A is detected by the photo sensor 85 detecting the protrusion 83 of the arm 82 so that the height of the top sheet TP falls within a certain range. The control part 24 (refer FIG. 1) is controlling the raise of FIG.

  As shown in FIG. 3, in each sheet supply device 50, an air blowing device 54 that blows air from the side surface of the sheet P stacked in the sheet supply tray 52 is disposed in the vicinity of the side surface fixed guide 66. . The air blowing device 54 is provided with a fan (not shown) that rotates in the direction of arrow K in the figure, and high-pressure air is supplied from an air outlet 70 formed in the plate 150 through a bendable connection duct 158. It is configured to blow out. Then, air is blown to the sheets P from the notches 71 formed in the side fixed guide 66, so that the air is sent between the stacked sheets P, and the sheets P are lifted, and the adhesion between the sheets P is released.

  As shown in FIG. 6, a rack (flat gear) 150A is formed on the side of the plate 150, and the rack 150A meshes with a gear 152 attached to a shaft of a drive mechanism (not shown). The plate 150 is supported by a guide rail (not shown) so as to be movable in the vertical direction. The drive mechanism rotates the gear 152 in both directions based on a signal from the control unit 24 (see FIG. 1). Therefore, the plate 150 moves up and down, that is, the air outlet 70 can move up and down. The air outlet 70 and the air outlet device 54 are connected by a flexible connecting duct 158. Therefore, even if the air outlet 70 moves up and down, the air supplied from the air outlet 54 is blown out from the air outlet 70.

  Next, the operation of the sheet feeding apparatus 50 according to the present invention will be described.

  4 and 5, when the sheet P is sent out, the solenoid 86 is operated based on the drive signal from the control unit 24 (see FIG. 1), and the arm 82 is lowered to bring the nudger roller 56 into the standby position B. To the delivery position A. In the sheet supply tray 52, the stacked sheets P rise due to the rise of the bottom plate 120 (see FIG. 6). When the top sheet TP comes into contact with the nudger roller 56 and is lifted upward, the protrusion 83 of the arm 82 is detected by the photo sensor 85, and the control unit 24 stops the bottom plate 120 from rising. Further, as the sheets P are sequentially fed out, when the position of the top sheet TP is lowered and the nudger roller 56 is lowered, the protrusion 83 of the arm 82 is not detected by the photo sensor 85, so the control unit 24 raises the bottom plate 120. Let Thus, the height of the top sheet TP is controlled so as to be within a certain range.

  Further, the air blowing device 54 is driven based on the drive signal from the control unit 24, and air is blown from the side surface of the stacked sheets P. Then, the stacked sheets P are floated by the blown air, and the adhesion between the sheets P is released. (See FIG. 5).

  As shown in FIG. 5, when the nudger roller 56 rotates in the direction of the arrow, the sheet P is fed out by frictional contact with the upper surface of the stacked top sheet TP. The sheet P sent out by the nudger roller 56 is sandwiched between the feed roller 58 and the retard roller 60, and the sheet P is conveyed one by one toward the downstream side. In addition, since the close contact between the sheets P stacked by air is released, so-called multi-feeding in which a plurality of sheets P are supplied in close contact is prevented.

  The top sheet TP separated and conveyed by the sheet supply device 50 is conveyed to a nip portion (see FIG. 1) between the photosensitive drum 14 and the transfer roller 34 by a sheet conveyance unit 44 having a plurality of conveyance rollers 46, and is a toner image. Is transcribed. The top sheet TP onto which the toner image has been transferred is sent to the fixing device 36 where the toner image is fixed. Then, the paper is discharged to the discharge tray 39 by the discharge roller 38.

  Now, in the case of the sheet P having a uniform thickness, the position of the air outlet 70 may be determined based on the delivery position A of the nudger roller 56 as shown in FIG. However, as shown in FIG. 10, the OHP sheet 200 having the mount portion 202 held by the hand at the front end portion is thick, and the transparent portion 204 other than the mount portion 202 is thin.

  As described above, when the OHP sheets 200 having different thicknesses of the mount portion 202 and the transparent portion 204 are stacked and accommodated in the sheet supply tray 52, as shown in FIG. ) And the transparent portion 204 have a height difference. (Note that FIG. 7 extremely illustrates the difference in thickness of the OHP sheet 200 for the sake of clarity). In this case, if the position of the air outlet 70 is the delivery position A, air does not hit the OHP sheet 200. (See FIG. 11). Therefore, the air blower outlet 70 is lowered to the optimum position of the air blower outlet 70.

  Below, the control method of the movement of the position of the air blower outlet 70 is demonstrated.

  First, the user operates the operation panel (see FIG. 1) to select the sheet type. The control unit 24 stores a reference position of the air outlet 70 with respect to a reference stacking amount for each selected sheet type. For example, the reference position (origin) G is stored for the sheet P having a uniform thickness, and the reference position a is stored for the OHP 200.

  When the bottom plate 120 in the sheet supply tray 52 rises, the stacked OHP sheet 200 rises, the top sheet TP comes into contact with the nudger roller 56, and when it is lifted upward, it is detected by the photo sensor 85, and the control unit 24 Stop climbing 120. Then, the control unit 24 detects the lift-up amount at that time. The load amount of the OHP sheet 200 can be determined from the detected lift-up amount.

  For example, if the lift-up amount in the case of 100 OHP sheets 200 is X and the lift-up amount is 2X, 200 OHP sheets 200 are stacked.

  When the loading amount of the OHP sheet 200 is detected, the control unit 24 moves the position of the air outlet 70 based on the reference position a and the loading amount.

  For example, when the reference stacking amount is 100 sheets and the reference position in that case is the reference position a, 200 OHP sheets 200 are currently stacked, and therefore, as shown in FIG. 7, the reference position a × (200 Sheets / 100 sheets) = the air outlet 70 is moved to the position of a × 2 = 2a.

  Now, when the OHP sheets 200 are sequentially sent out and the remaining amount of the OHP sheets 200 decreases, the height difference between the mount portion 202 and the transparent portion 204 of the top sheet TP decreases as shown in FIG. Therefore, the control unit 24 counts the number of feeds in which the OHP sheets 200 are sequentially sent out, and moves the air outlet 70 upward.

  For example, assuming that the number of feeds is 150, the air outlet 70 is moved to a position of 2a-1.5a = 0.5a from (a × 2) − (feeds / 100) × a.

  Thus, the optimum air outlet 70 position is obtained regardless of the type of sheet, the stacking amount, and the remaining amount of sheets (number of feeds). Therefore, regardless of the type of sheet, the stacking amount, and the remaining amount of sheets (number of sheets fed), the sheet is lifted by the air and the adhesion between the sheets is released.

  The present invention is not limited to the above embodiment.

  For example, when the air blower outlet 70 is moved as the remaining amount of the OHP sheet 200 decreases, the air blower outlet 70 is not moved every time one sheet is sent out, but is stepped for each predetermined number of feeds as shown in FIG. Alternatively, the air outlet 70 may be moved.

  Further, for example, as shown in FIG. 9B, the air outlet 70 may be moved up and down periodically. By moving the air outlet 70 up and down in this way, air is blown in order from the stacked upper sheet to the lower sheet and from the lower sheet to the upper sheet. For this reason, for example, it is possible to prevent the upper sheets from being floated in a bundled state from the weakly adhered portion, so that the adhesion between the stacked sheets can be more effectively solved. Therefore, double feeding and the like are prevented more reliably.

  Further, for example, the load amount is detected by the lift-up amount of the bottom plate 120, but the number of sheets stored in the sheet supply tray 52 by the user may be input to the operation panel (see FIG. 1). Or you may input how many times it is with respect to a reference | standard load capacity. In this case, if the reference stacking amount is set to one pack of commercially available sheets and the number of packs stored is input, the user's operation becomes simple.

  Further, for example, the remaining sheet amount may be detected based on the lift-up amount of the bottom plate 120.

  In the above embodiment, a known electrophotographic process is used as an image forming method, but the present invention is not limited to this. For example, the image forming method may be a known ink jet recording method, or may be another image forming method.

  The above embodiment is an example of the image forming apparatus. However, the present invention is not limited to the image forming apparatus, and may be applied to other devices for conveying a sheet, such as a cutting machine or a press machine. Is possible.

1 is a schematic configuration diagram illustrating an image forming apparatus including a sheet supply apparatus according to an embodiment of the present invention. It is a perspective view which shows the sheet supply apparatus which concerns on embodiment of this invention. It is a top view which shows the sheet supply apparatus which concerns on embodiment of this invention. It is a perspective view which shows the feeding mechanism of the sheet supply apparatus which concerns on embodiment of this invention. It is a figure which shows the stand-by position and sending position of a nudger roller. It is a figure which shows the position of the air blower outlet when the sheet | seat with uniform thickness is loaded and accommodated. It is a figure which shows the position of the air blower outlet at the time of stacking and accommodating the OHP sheet | seat with non-uniform thickness. It is a figure which shows the position of an air blower outlet when the OHP sheet | seat with non-uniform thickness is loaded and accommodated and the sheet | seat residual amount reduces. (A) is a graph showing a stepwise movement of the air outlet according to the number of feeds, and (B) is a graph showing a case where the position of the air outlet moves up and down in a predetermined cycle. It is a perspective view which shows an OHP sheet with non-uniform thickness. It is a figure which shows the position of the air blower outlet at the time of loading and accommodating the OHP sheet | seat with non-uniform thickness in the conventional sheet supply apparatus.

Explanation of symbols

11 Operation panel (sheet type selection means, load amount input means)
24 control unit (storage means, control means, lift-up control means, remaining sheet detection means)
50 Sheet supply device 52 Sheet supply tray (container)
54 Air blowing device (Air blowing means)
70 Air outlet (Blowing position moving means)
90 Feeding mechanism (feeding means, top sheet position detecting means)
120 Bottom plate (lift-up means)
150 plate (spraying position moving means)
150A rack (spraying position moving means)
152 Gear (Blowing position moving means)
158 Connection duct (spraying position moving means)
200 OHP sheet (sheet)
P sheet TP top sheet (top sheet)

Claims (8)

A storage section for stacking and storing sheets;
A feeding means for supplying the sheet accommodated in the accommodating portion to the next process;
Air blowing means for blowing air against the sheet accommodated in the accommodating portion;
A blowing position moving means for moving an air blowing position of the air blowing means with respect to a stacking direction of the sheets;
Storage means for storing a reference position of the spray position defined for each type of the sheet;
In a sheet supply apparatus provided with a sheet type selection means for selecting the type of the sheet,
A selection result of the sheet type selection means;
The reference position stored in the storage means;
A sheet supply apparatus comprising: control means for controlling the spray position moving means based on the above. A storage section for stacking and storing sheets;
A feeding means for supplying the sheet accommodated in the accommodating portion to the next process;
Air blowing means for blowing air against the sheet accommodated in the accommodating portion;
A blowing position moving means for moving an air blowing position of the air blowing means with respect to a stacking direction of the sheets;
Storage means for storing a reference position of the spray position defined for each type of the sheet;
In a sheet supply apparatus provided with a sheet type selection means for selecting the type of the sheet,
A loading amount input means for inputting a loading amount of the sheet to be accommodated in the accommodating portion;
The load amount input to the load amount input means;
A selection result of the sheet type selection means;
The reference position stored in the storage means;
A sheet supply apparatus comprising: control means for controlling the spray position moving means based on the above. A storage section for stacking and storing sheets;
A feeding means for supplying the sheet accommodated in the accommodating portion to the next process;
Air blowing means for blowing air against the sheet accommodated in the accommodating portion;
A blowing position moving means for moving an air blowing position of the air blowing means with respect to a stacking direction of the sheets;
Storage means for storing a reference position of the spray position defined for each type of the sheet;
In a sheet supply apparatus provided with a sheet type selection means for selecting the type of the sheet,
A load amount detecting means for detecting the load amount of the sheets stored in the storage portion;
A detection result of the load amount detection means;
A selection result of the sheet type selection means;
The reference position stored in the storage means;
A sheet supply apparatus comprising: control means for controlling the spray position moving means based on the above. A storage section for stacking and storing sheets;
A feeding means for supplying the sheet accommodated in the accommodating portion to the next process;
Air blowing means for blowing air against the sheet accommodated in the accommodating portion;
A blowing position moving means for moving an air blowing position of the air blowing means with respect to a stacking direction of the sheets;
Storage means for storing a reference position of the spray position defined for each type of the sheet;
In a sheet supply apparatus provided with a sheet type selection means for selecting the type of the sheet,
A sheet remaining amount detecting means for detecting a sheet remaining amount of the sheet stored in the storage unit;
A detection result of the sheet remaining amount detection means;
A selection result of the sheet type selection means;
The reference position stored in the storage means;
A sheet supply apparatus comprising: control means for controlling the spray position moving means based on the above. A storage section for stacking and storing sheets;
A feeding means for supplying the sheet accommodated in the accommodating portion to the next process;
Air blowing means for blowing air against the sheet accommodated in the accommodating portion;
A blowing position moving means for moving an air blowing position of the air blowing means with respect to a stacking direction of the sheets;
Storage means for storing a reference position of the spray position defined for each type of the sheet;
In a sheet supply apparatus provided with a sheet type selection means for selecting the type of the sheet,
A stack amount input unit that inputs a stack amount of the sheets stored in the storage unit, and a sheet remaining amount detection unit that detects a remaining sheet amount of the sheets stored in the storage unit,
An input result input to the load amount input means;
A detection result of the sheet remaining amount detection means;
A selection result of the sheet type selection means;
The reference position stored in the storage means;
A sheet supply apparatus comprising: control means for controlling the spray position moving means based on the above. A storage section for stacking and storing sheets;
A feeding means for supplying the sheet accommodated in the accommodating portion to the next process;
Air blowing means for blowing air against the sheet accommodated in the accommodating portion;
A blowing position moving means for moving an air blowing position of the air blowing means with respect to a stacking direction of the sheets;
Storage means for storing a reference position of the spray position defined for each type of the sheet;
In a sheet supply apparatus provided with a sheet type selection means for selecting the type of the sheet,
A stack amount detection unit that detects a stack amount of the sheets stored in the storage unit, and a sheet remaining amount detection unit that detects a remaining sheet amount of the sheets stored in the storage unit,
A detection result of the load amount detection means;
A detection result of the sheet remaining amount detection means;
A selection result of the sheet type selection means;
The reference position stored in the storage means;
A sheet supply apparatus comprising: control means for controlling the spray position moving means based on the above. A top sheet position detecting means for detecting the position of the uppermost sheet of the sheet stored in the storage unit;
Lift-up means for lifting up the seat accommodated in the accommodating portion;
According to the detection result of the top sheet detection means, comprising a lift-up control means for controlling the lift-up amount of the lift-up means,
The sheet feeding apparatus according to claim 3, wherein the stacking amount detection unit detects the stacking amount of the sheets based on the lift-up amount.   The sheet feeding apparatus according to claim 1, wherein the control unit moves the spray position up and down at a predetermined cycle.

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