JP2020152535A - Sheet feeding device and image formation apparatus - Google Patents

Abstract

To provide a sheet feeding device and image formation apparatus which can reduce the cost of the device.SOLUTION: A sheet feeding device comprises: air spray means which floats a sheet on the upper part of a sheet bundle by spraying the air to the sheet bundle loaded on a sheet loading part; feeding means which feeds the floating uppermost sheet; and imaging means which images the sheet floated by the air spray means. The imaging range of the imaging means is set such that the feeding surface of the feeding means and at least the uppermost sheet of the sheet bundle loaded on the sheet loading part are imaged.SELECTED DRAWING: Figure 9

Description

The present invention relates to a sheet feeding device and an image forming device.

Conventionally, air has been blown onto the seat bundle loaded on the seat loading portion to raise the upper sheet of the seat bundle, an air blowing means for feeding the surfaced top sheet, and an air blowing means. A sheet feeding device including an imaging means for imaging a sheet is known.

In Patent Document 1, as the sheet feeding device, a sensor that detects that a bundle of sheets loaded on a sheet loading portion has reached an optimum levitation position, and an image pickup that captures a surfaced top sheet and a second sheet. Those provided with means are described. In order to take a good picture of the raised top sheet and the second sheet, an imaging means for taking a picture of the side surface of the sheet edge when the top sheet is not in contact with the feeding surface of the feeding means is arranged. There is.

However, in the sheet feeding device described in Patent Document 1, there is a risk that the device cost will be high.

In order to solve the above-mentioned problems, the present invention supplies an air blowing means for blowing air onto a seat bundle loaded on the seat loading portion to raise the upper sheet of the seat bundle, and a floating top sheet. In a sheet feeding device including a feeding means for feeding and an imaging means for photographing a sheet surfaced by the air blowing means, the feeding surface of the feeding means and at least a sheet loaded on the sheet loading portion. It is characterized in that the imaging range of the imaging means is set so that the top sheet of the bundle is photographed.

According to the present invention, the cost of the device can be reduced.

The schematic block diagram which shows the image forming apparatus and the sheet feeding unit of this embodiment. The schematic block diagram of the image forming apparatus which concerns on this embodiment. The schematic explanatory view of the sheet feeding apparatus of this embodiment provided on the side surface of the apparatus main body. Schematic perspective view of the vicinity of the storage tray. Perspective view of the front blower. Schematic plan view of the containment tray. The block diagram which shows an example of the main part structure of the control system in this image forming apparatus. The figure explaining the feeding operation. The schematic diagram which shows the imaging range of an image sensor. (A) is a schematic diagram showing a state when the light source is turned on, and (b) is a schematic diagram showing an image taken by an image sensor with the light source turned on. The figure explaining an example of image processing by an image processing unit. The flow chart of the initial operation based on the photographed image of an image sensor. Air volume adjustment flow chart based on the captured image of the image sensor. The figure which shows the distance between the belt suction surface and the top sheet during a paper feed preparation operation. Operation flow diagram of belt feed control. The figure which shows the distance between the belt suction surface and the top sheet in a separation process. The figure which shows an example of the timing chart in continuous delivery.

Hereinafter, an embodiment of a sheet feeding device to which the present invention is applied will be described.
FIG. 1 is a schematic configuration diagram showing an image forming apparatus 100 and a sheet feeding apparatus 200.
As shown in FIG. 1, in the image forming apparatus 100, in addition to the feeding unit 114 mounted as standard in the image forming apparatus 100, a sheet feeding means as a sheet feeding means capable of loading a large amount of sheets is provided. It has a device 200. The sheet feeding device 200 is provided on the side surface of the image forming device 100 main body.

First, among the electrophotographic type and inkjet type image forming devices to which the sheet feeding device of the present embodiment can be applied, the overall configuration and operation of the image forming device will be described by taking the electrophotographic type image forming device as an example. To do.

FIG. 2 is a schematic configuration diagram of the image forming apparatus 100 according to the present embodiment.
This image forming apparatus includes an image forming unit 110 as an image forming means, a feeding unit 114 on which the image forming unit 110 is placed, a scanner 130 fixed on the image forming unit 110, and the like. It also includes an automatic document transfer device 140 fixed on the scanner 130.

The image forming unit 110 has five image forming units 101S, 101Y, for forming an image of each color of special color (S), yellow (Y), magenta (M), cyan (C), and black (K). It includes 101M, 101C, and 101K. The subscripts S, Y, M, C, and K added after the numbers of each code mean that they are members for special colors, yellow, cyan, magenta, and black (the same applies hereinafter). The special color is a general term for colors different from any of Y, M, C, and K, and examples thereof include white.

Since the configurations and operations of the image-forming units 101S, 101Y, 101M, 101C, and 101K are substantially the same, the color symbols (S, Y, M, C, K) are omitted here for image-drawing. The unit will be described. In the image forming unit 101, a charger 103, a developing device 104, a cleaning device 105, and the like are arranged around the photoconductor drum 102 as an image carrier. Further, the exposure means 107 is arranged above the photoconductor drum 102.

Below the five image forming units 101S, 101Y, 101M, 101C, and 101K, intermediate transfer belts 108 hung around a plurality of support rollers are arranged. The intermediate transfer belt 108 is driven to travel in the direction of arrow A by rotationally driving one of the support rollers by a driving means. A transfer roller 106 as a primary transfer means is arranged so as to face the photoconductor drum 102 of each image forming unit with the intermediate transfer belt 108 interposed therebetween.

In each image forming unit 101, the photoconductor drum 102 is rotationally driven counterclockwise in the drawing, and the photoconductor surface is uniformly charged to a predetermined polarity by the charger 103. Next, the charged surface is irradiated with a light-modulated laser beam emitted from the exposure means 107, whereby an electrostatic latent image is formed on the photoconductor drum 102. The electrostatic latent image is developed by the toner applied from the developing device 104 and visualized as a toner image. The special color, yellow, magenta, cyan, and black toner images formed by each image forming unit 101 are sequentially superimposed and transferred on the intermediate transfer belt 108.

On the other hand, the feeding unit 114 has accommodation trays 114a and 114b, and the sheet is fed from either the feeding unit 114 or the sheet feeding device 200 described later attached to the image forming device 100. .. The fed sheet is conveyed toward the resist roller 111 as shown by arrow B.

The sheet includes paper, coated paper, label paper, OHP sheet, film, prepreg and the like. The prepreg is mainly used as a material for laminated boards and multilayer printed wiring boards. For example, a long base material such as glass cloth, paper, non-woven fabric, or aramid cloth is continuously impregnated with a resin varnish mainly composed of a thermosetting resin such as epoxy resin or polyimide resin, dried by heating, and then cut. Therefore, it is processed into a sheet material.

The sheet that has been abutted against the resist roller 111 and temporarily stopped is sent out from the resist roller 111 at the timing of the toner image on the intermediate transfer belt 108, and the secondary transfer roller 109 and the intermediate transfer belt 108 are in contact with each other. It is sent to the next transfer section. A voltage opposite to the charging polarity of the toner is applied to the secondary transfer roller 109, whereby the layered toner image (full-color image) on the intermediate transfer belt 108 is transferred onto the sheet. The sheet after the toner image is transferred is conveyed to the fixing device 113 by the conveying belt 112, and the toner is fixed to the sheet by heat and pressure in the fixing device 113. The sheet after the toner image is fixed is discharged to the outside of the machine as shown by an arrow C, and is discharged onto the paper ejection tray.

In the case of single-sided printing, backside paper ejection (face-down paper ejection) is performed, the front and back sides of the sheet are reversed by ejecting the sheet to the outside of the machine as shown by an arrow C through the sheet reversing portion 115. Further, in the case of double-sided printing, the sheet after fixing is re-fed to the resist roller 111 from the refeeding path 117 via the double-sided reversing portion 116, and the toner image is transferred from the intermediate transfer belt 108 to the back surface of the sheet. The sheet after the toner image transfer is fixed by the fixing device 113, and as shown by the arrow C from the fixing device 113 as in the case of single-sided printing, or as shown by the arrow C via the sheet reversing portion 115, the sheet is removed from the machine. It is ejected and is ejected on the output tray. Switching claws 118 and 119 for switching the sheet transport direction are appropriately arranged.

In the case of monochrome printing, in the image forming apparatus 100 of this example, a toner image is imaged using only the black (K) image forming unit 101K, and the toner image is transferred onto the sheet via the intermediate transfer belt 108. To do. The handling of the sheet after fixing the toner image is the same as in the case of full-color printing.

A toner bottle setting unit 120 for setting each color toner bottle 121 containing toner to be supplied to the developing device 104 of each image forming unit is provided on the upper surface of the apparatus main body. Further, an operation unit 124 having a display unit 122 and an operation panel 123 is also provided on the upper surface of the apparatus main body. Further, a sheet loading portion D from a sheet feeding device (see FIG. 3), which will be described later, is provided on the right side surface of the device main body. The sheet loading section D is provided with an opening 125 for receiving the sheet and a transporting means 126 for transporting the sheet.

FIG. 3 is a schematic explanatory view of the sheet feeding device 200 of the present embodiment provided on the side surface of the device main body.
As shown in FIG. 3, the sheet feeding device 200 includes two upper and lower storage trays 10. Each storage tray 10 includes a sheet mounting table 11 for loading the sheet bundle P. In the present embodiment, each storage tray 10 can store a maximum of about 2500 sheets. Above each storage tray 10, a feeding unit 20 for separating and feeding the sheets loaded on the storage tray 10 is arranged. The feeding unit 20 includes a suction belt 21 and a suction device 23, which are transport means.

The sheet loaded on the lower storage tray 10 is conveyed to the image forming apparatus 100 main body by the outlet roller pair 80 through the lower transfer path 82. The sheet loaded on the upper storage tray 10 is conveyed to the image forming apparatus 100 main body by the outlet roller pair 80 through the upper transfer path 81.

FIG. 4 is a schematic perspective view of the vicinity of the storage tray 10. In FIG. 4, for easy understanding, the feeding unit 20 is marked by shifting it in the direction of the arrow K in the figure from the original arrangement location.
The suction belt 21 of the feeding unit 20 serving as the feeding means is stretched by two tension rollers 22a and 22b, and suction holes penetrating from the front surface side to the back surface side of the belt are provided in the entire circumferential direction. ing. Further, a suction device 23 is provided inside the suction belt 21. The suction device 23 is connected to a suction fan that sucks air through an air duct that is an air flow path, and the suction device 23 generates a negative pressure downward to suck the sheet on the lower surface of the suction belt 21. Acts like. The air sucked by the suction device 23 is called suction air.

Further, the accommodating tray 10 is provided with a blower device 17 which is an air blowing means for blowing air onto the sheet above the sheet bundle P. The blower 17 has a front blower 12 and a side blower 14.

The side blower 14 is provided on the pair of side fences 13 and blows air to the upper side surface of the seat bundle P in the direction indicated by the arrow b in the drawing. The side blower 14 is provided with a side levitation nozzle that handles the sheet bundle P and guides air in the direction of levitation, and has a side blower 14a that sends air to this nozzle. The air blown from the side levitation nozzle in the direction indicated by the arrow b in the figure is called side air. This side air is discharged from a discharge port 13a provided at a position facing the upper portion of the seat bundle P of each side fence 13, and is sprayed on the side surface of the upper portion of the seat bundle P. The air blown from the front blower 12 and the discharge ports of the pair of side fences 13 raises the upper sheet of the sheet bundle.

Further, the storage tray 10 is provided with an end fence 25 for aligning the rear ends of the seat bundle P loaded on the seat mounting table 11 serving as the seat loading portion. The seat mounting table 11 is configured to be able to move up and down in the direction of arrow E in the figure by an elevating device 19 as a moving means.

FIG. 5 is a perspective view of the front blower device 12.
The front blower device 12 blows air to the upper tip (downstream end in the feeding direction) of the seat bundle P. The front blower 12 includes a levitation nozzle 15a that guides air in the direction of levitation of the sheet bundle P, a separation nozzle 16a that guides and separates air between the uppermost levitation sheet and the second levitation sheet, and levitation. A floating blower 15 that sends air to the nozzle 15a and a separation blower 16 that sends air to the separation nozzle 16a are arranged. Further, an air chamber 18 having a floating air chamber portion 18a and a separation air chamber portion 18b is provided.

Of the nozzles, the air blown from the levitation nozzle 15a is called levitation air, and the air blown from the separation nozzle 16a is called separation air. The levitation air is blown out in the direction of arrow a1 in FIG. 4 from a portion facing the upper tip of the sheet bundle P (downstream end in the feeding direction), and the upper tip of the sheet bundle P (downstream end in the feeding direction). Is sprayed on. The separated air is blown out in the direction of arrow a2 in FIG. 4 from a portion facing the upper tip (downstream end in the feeding direction) of the sheet bundle P, and the uppermost sheet adsorbed on the suction belt 21 and the second sheet surfaced. It is sprayed between.

Further, a levitation shutter member 24 capable of blocking air sent to the levitation nozzle 15a is arranged in the levitation air chamber portion 18a. Both the levitation shutter members 24 are plate-shaped members and are attached to the rotating shaft 24a.

An arm member 26 extending in a direction orthogonal to the axial direction of the rotating shaft 24a is attached to one end of the rotating shaft 24a. The rotating shaft 24a is attached to the substantially center of the arm member 26. A shutter solenoid 28 is connected to one end of the arm member 26 via a connecting member 27. A spring 29 is attached to the other end of the arm member 26 to urge the arm member 26 downward in the drawing.

When the shutter solenoid 28 is not driven, the levitation shutter member 24 is located in the open position due to the urging force of the spring 135. When the shutter solenoid 28 is driven to move the connecting member 27 downward in the drawing against the urging force of the spring 29, one end side of the arm member 26 (the side to which the connecting member 27 is attached) is lowered. The arm member 26 rotates so that the other end side rises. The rotation of the arm member 26 causes the rotation shaft 24a to rotate, and the levitation shutter member 24 to rotate. Then, it rotates 90 degrees, and as shown in FIG. 5, when the levitation shutter member 24 is positioned at the closed position, the movement of the connecting member 27 stops. As a result, the blowing of the floating air is stopped.

Further, in the above description, only the floating air is blocked by the shutter member, but the shutter member may be provided for the separated air and the side air in the same manner, and the blower may be blocked by the shutter member.

FIG. 6 is a schematic plan view of the storage tray 10.
As shown in FIG. 6, a pair of regulation plates 33 for aligning the tips of the sheet bundles are provided on the downstream side of the storage tray 10 in the sheet transport direction. By abutting the tip of the sheet bundle P loaded on the seat mounting table 11 against the regulation plate 33, the position of the tip of the sheet bundle is regulated and positioned.

Further, on the downstream side of the storage tray 10 in the sheet transport direction, the belt suction surface 21a (see FIG. 8) of the suction belt 21, which is the feed surface to which the floating top sheet is contacted (sucked) and fed, An image pickup device 30 for imaging the floating sheet and the upper part of the sheet bundle whose upper surface (top sheet) is located at the optimum floating position (the position where the upper sheet of the sheet bundle is appropriately floated by the floating air or the like) is provided. There is. The image pickup device 30 includes an image pickup device 31 as an image pickup means such as a CCD, and a light source 32 such as an LED that illuminates the shooting range of the image pickup device 31. Since the inside of the sheet feeding device 200 is covered with an exterior cover, the inside of the sheet feeding device 200 is dark. Therefore, the image sensor 31 alone cannot accurately discriminate the belt suction surface 21a, the floating sheet, the upper part of the sheet bundle, and the like from the captured image. Therefore, by providing the light source 32 to illuminate the image pickup range of the image pickup element, it is possible to accurately discriminate the belt suction surface 21a, the floating sheet, and the upper part of the sheet bundle from the captured image.

The light source 32 is provided at the center of the sheet in the width direction, and is arranged so as to illuminate the center of the tip of the sheet in the width direction, which is photographed by the image sensor 31. The image pickup element 31 is arranged on one side in the sheet width direction so that the image pickup surface of the image pickup element 31 faces the central portion of the sheet tip in the width direction.

In the present embodiment, as will be described later, elevating control of the elevating device 19, air volume adjustment of the blower device 17, and feeding control of the top sheet adsorbed on the suction belt 21 are performed based on the image taken by the image sensor 31. To do.

FIG. 7 is a block diagram showing an example of the main configuration of the control system in the image forming apparatus 100. In the figure, the image pickup device 30 is connected to the control unit 66 as the control means of the sheet feeding device 200. Specifically, the image sensor 31 and the light source 32 of the image pickup device 30 are connected to the control unit 66. It also has an image processing unit 69 that processes the image captured by the image sensor 31.

A blower 17 and a suction device 23 are also connected. Further, a shutter solenoid 28 for opening and closing the levitation shutter member 24 and an elevating drive motor 65 included in the elevating device 19 for elevating and lowering the seat mounting table 11 are also connected. Further, the control unit 66 of the seat feeding device 200 is connected to the feeding motor 68 that drives the suction belt 21 included in the feeding unit 20. Further, the control unit 66 of the sheet feeding device 200 is connected to the host controller 67 of the image forming device 100. Various devices of the image forming apparatus 100, such as the operation unit 124, are connected to the host controller 67.

The control unit 66 controls the drive of the elevating drive motor 65 based on the image captured by the image sensor 31 of the image pickup device 30. Further, the control unit 66 controls the side blower 14a, the levitation blower 15, the separation blower 16, and the like of the blower 17 based on the image taken by the image sensor 31 of the image pickup device 30, and controls the levitation air, the separation air, and the side. Adjust the air volume such as air. Further, the control unit 66 controls the feeding motor 68 to control the feeding of the top sheet sucked on the suction belt 21 based on the image taken by the image sensor 31 of the image pickup device 30. Details of the control based on the images captured by these image pickup devices 31 will be described later.

Next, the feeding operation will be described.
FIG. 8 is a diagram illustrating a feeding operation.
There are four main feeding operations: the levitation process shown in FIG. 8A, the suction process shown in FIG. 8B, the separation process shown in FIG. 8C, and the feeding process shown in FIG. 8D. Consists of processes.
First, when the control unit 66 receives a command to start feeding from the host controller of the image forming apparatus 100 main body, the levitation process in the feeding operation shown in FIG. 8A is executed.
First, the air blowing device 17 is started with the suction belt 21 stopped, and the floating air, the separated air, and the side air are blown from the floating nozzle 15a, the separation nozzle 16a, and the side nozzle. By blowing the floating air and the side air to the tip side of the upper part of the sheet bundle, a plurality of sheets on the upper part of the sheet bundle are floated, and at least the highest sheet among the floating sheets is attracted by the suction device 23. Ascend to a working height.

The suction process shown in FIG. 8B is performed at the timing when at least the uppermost sheet among the surfaced sheets is floated to a height at which the suction force of the suction device 23 acts. In the suction process, suction of the suction device 23 is started (driving of the suction fan is started), and a negative pressure is generated below the belt suction surface 21a of the suction belt 21. Then, the floating sheet moves to the suction belt 21 side due to the negative pressure, and the uppermost sheet P1 is sucked on the belt suction surface 21a of the suction belt 21.

In the description of FIG. 8, the suction of the suction device 23 is started at the timing when the uppermost sheet rises to a height at which the suction force of the suction device 23 acts, but at the timing when the ventilation of the blower device 17 is started. The suction of the suction device 23 may be started.

When the uppermost sheet is adsorbed on the suction belt 21, the negative pressure below the belt suction surface 21a is eliminated, and separated air flows between the uppermost sheet P1 adsorbed on the suction belt 21 and the second sheet, and the uppermost sheet is formed. The sheet P1 and the second sheet are separated.

When the upper sheet is adsorbed on the suction belt 21 in this way, the process proceeds to the separation process shown in FIG. 8 (c). In the separation process, the shutter solenoid 28 is driven to move the levitation shutter member 24 to the closed position and stop the blowing of levitation air. Further, the drive of the separation blower 16 is stopped, or the shutter that shuts off the separation air is driven to stop the blowing of the separation air. By stopping the blowing of the levitation air in this way, the levitation force due to the air applied to the seat is reduced, and the second and subsequent seats fall. As a result, the distance between the uppermost sheet P1 adsorbed on the suction belt 21 and the second sheet P2 is opened by a predetermined value or more, and the uppermost sheet P1 and the second sheet are separated.

When the distance between the belt suction surface 21a of the suction belt 21 and the second sheet P2 is opened by a predetermined value or more, the process proceeds to the feeding process as shown in FIG. 8D. In the feeding process, the feeding motor 68 is driven to rotate and drive the suction belt 21, and the top sheet sucked on the suction belt 21 is fed. Specifically, when the distance between the belt suction surface 21a and the tip of the second sheet P2 is equal to or greater than the distance L1 (see FIG. 9) between the belt suction surface 21a and the tip of the regulation plate 33, the suction belt 21 is released. The top sheet sucked on the suction belt 21 is fed by rotational driving. This is because, on the front end side of the sheet, even if the top sheet P1 adsorbed on the belt suction surface and the second sheet P2 are separated, the top sheet is in contact with the second sheet on the rear end side. There is. Therefore, when the uppermost sheet is fed, the second sheet may be subjected to a conveying force due to friction between the uppermost sheet on the rear side and the second sheet. At that time, if the distance between the belt suction surface 21a and the tip of the second sheet P2 is at least the distance L1 (see FIG. 9) between the belt suction surface 21a and the tip of the regulation plate 33, the rear side Even if a conveying force is applied to the second sheet P2, the tip of the sheet hits the regulation plate 33 and is not conveyed. Therefore, when the distance between the belt suction surface 21a and the tip of the second sheet P2 is equal to or greater than the distance L1 (see FIG. 9) between the belt suction surface 21a and the tip of the regulation plate 33, the suction belt 21 is rotationally driven. Therefore, by feeding the top sheet sucked on the suction belt 21, the feeding of the second sheet can be suppressed, and the occurrence of double feeding can be suppressed.

In the present embodiment, the side air is constantly blown in the series of paper feeding operations shown in FIGS. 8A to 8D, but the side air blowing is stopped during the separation process and the feeding process. You may. However, by not stopping the spraying of the side air, a plurality of sheets are slightly levitated with respect to the sheet bundle during the feeding operation, and in the ascending process of the next feeding operation in continuous feeding, the next in a short time. The top sheet in the feeding operation of the above can be levitated to a height at which the suction force of the suction device 23 acts, and the productivity in the continuous feeding can be improved.

Further, in the present embodiment, when the start and stop of the blowing of the floating air is controlled by opening and closing the floating shutter member 24, the start and stop of the blowing of the floating air is controlled by turning on / off the floating fan. In comparison, the floating air air volume can be set to the specified air volume in a short time, the blowing of the floating air can be stopped, the floating process and the separation process can be shortened, and the productivity in continuous feeding can be achieved. Can be enhanced.

FIG. 9 is a schematic view showing the imaging range of the image sensor 31.
As shown in FIG. 9, the tips of the pair of regulating plates 33 are separated by a distance L1 from the belt suction surface 21a of the suction belt 21. Further, as shown by a broken line in the figure, the image pickup range of the image pickup device 31 is set so that the belt suction surface 21a and the upper portion of the sheet bundle P whose upper surface is located at the optimum levitation position can be seen. In this way, the image pickup range of the image pickup element 31 is set so that the belt suction surface 21a and the upper portion of the sheet bundle P whose upper surface is located at the optimum levitation position can be seen, so that the image taken by the image pickup element 31 can be seen. It is possible to grasp the behavior of the floating sheet floating between the belt suction surface and the sheet bundle and the position of the upper surface (top sheet) of the sheet bundle. As a result, the number of parts can be reduced and the cost of the device can be reduced as compared with a sensor for grasping the position of the upper surface of the sheet bundle, which is provided separately from the image pickup device.

FIG. 10A is a schematic diagram showing a state when the light source 32 is turned on, and FIG. 10B is a schematic diagram showing an image taken by the image sensor 31 with the light source 32 turned on. is there.
As described above, the inside of the sheet feeding device 200 is covered with an exterior cover and is dark. Therefore, as shown in FIG. 10A, when the light source 32 is turned on, the tip of the upper part of the sheet bundle located at the center in the width direction on the downstream side of the belt suction surface 21a of the suction belt 21 in the sheet transport direction and at the optimum levitation position. The central part in the width direction of is illuminated. Further, the central portion in the width direction of the sheet tip floating between the belt suction surface 21a and the sheet bundle is also illuminated.

By illuminating the belt suction surface 21a, the upper part of the sheet bundle, and the floating sheet with the light source 32, the reflected light from these is projected onto the image pickup element 31 and photographed by the image pickup element 31 as shown in FIG. 10B. To.

The image taken by the image sensor 31 is sent to the image processing unit 69. The image processing unit 69 processes an image within the predetermined image processing range shown by the broken line in FIG. 10B, measures the distance from the belt suction surface to the object to be measured, and determines the floating state and the position of the sheet bundle. Etc. are detected. The image processing range is set to include the belt suction surface 21a, the upper part of the sheet bundle, and the portion illuminated by the light source 32 of the floating sheet.

FIG. 11 is a diagram illustrating an example of image processing by the image processing unit 69.
First, as shown in FIG. 11A, the image processing unit 69 binarizes the image captured by the image sensor 31. The binarization is a process of converting the brightness value to 0 (black) for pixels having a brightness value less than a predetermined threshold value and converting the brightness value to 255 (white) for pixels having a brightness value equal to or higher than the threshold value. Is. The threshold value of the binarized brightness is set by experimentally obtaining an optimum value at which the floating sheet, the belt suction surface 21a, and the upper part of the sheet bundle can be clearly distinguished when binarized.

Next, as shown in FIG. 11B, the image processing unit 69 extracts a region in which pixels (white) having a brightness of 255 are connected based on the binarized image data, and each connection region. Is recognized as one object.

For example, during the initial operation in which the seat mounting table 11 is raised by the elevating device 19 to position the sheet bundle at the optimum floating position, the blower device 17 is stopped, so that the image taken by the image sensor 31 at that time is processed. The resulting connecting region is two, the uppermost connecting region corresponds to the belt suction surface 21a, and the other connecting region (bottom connecting region) corresponds to the sheet bundle.

On the other hand, the connecting regions obtained by processing the image taken by the image pickup device 31 during the levitation process and the suction process are the uppermost connecting region corresponding to the belt suction surface 21a and the lowermost connecting region corresponding to the sheet bundle. It becomes a connecting region of the above and a connecting region corresponding to one or more floating sheets floating between the belt suction surface 21a and the sheet bundle.

Further, the connecting region obtained by processing the image taken by the image pickup device 31 during the separation process or the transport process is the uppermost connecting region corresponding to the belt suction surface 21a and the top sheet sucked on the belt suction surface. Then, it becomes a bottom connecting region corresponding to the sheet bundle and a connecting region corresponding to one or more floating sheets floating between the belt suction surface 21a and the sheet bundle.

Next, the image processing unit 69 acquires the desired information based on the extracted plurality of connected regions. For example, when it is desired to obtain the distance between the belt suction surface 21a and the raised top sheet P1, as shown in FIG. 11, from a plurality of connecting regions, the top connecting region and the second connecting region from the top are formed. And extract. Then, as shown in FIG. 11D, the pixels in the vertical direction from the lowermost end of the uppermost connecting area to the uppermost end of the second connecting area from the top are counted, and the number of pixels obtained by counting is counted. Converts from to the vertical distance between two objects. As a result, the distance between the belt suction surface and the raised top sheet can be calculated from the image taken by the image sensor 31. In this way, by obtaining the distance between the belt suction surface 21a and the raised top sheet P1 from the image captured by the image sensor 31, the floating state of the sheet can be grasped, and each air of the blower 17 can be grasped. The air volume (floating air, side air, etc.) can be adjusted.

Further, for example, when it is desired to obtain the distance from the belt suction surface 21a to the upper surface of the sheet bundle, the pixels from the lowermost end of the uppermost connecting region to the uppermost end of the lowermost connecting region are counted and counted. By converting the number of pixels thus obtained into a distance, the distance from the belt suction surface 21a to the upper surface of the sheet bundle can be calculated. In this way, by obtaining the distance from the belt suction surface 21a to the upper surface of the sheet bundle from the image taken by the image sensor 31, it is possible to perform the elevating control to position the sheet bundle at the optimum levitation position.

Further, as described above, the uppermost connecting region extracted by processing the image taken by the image sensor 31 during the separation process (see FIG. 8C) and the feeding process (see FIG. 8D). Corresponds to the belt suction surface 21a and the top sheet sucked on the belt suction surface 21a. Therefore, it is difficult to distinguish the belt suction surface 21a from the uppermost connecting region, and the measurement object (top level) based on the belt suction surface 21a from the image taken by the image pickup device 31 during the separation process or the feeding process. It becomes difficult to calculate the distance (the upper surface of the floating sheet or the sheet bundle).

Therefore, the position of the lower end (pixel position) of the uppermost connecting region corresponding to the belt suction surface 21a obtained by processing the image taken during the initial operation is used as a reference position and stored in the storage means. preferable. As a result, when calculating the distance from the belt suction surface 21a to the object to be measured (the uppermost floating sheet or the upper surface of the sheet bundle) from the image taken by the image sensor 31 during the separation process or the transfer process, the storage means is used. By counting the pixels between the stored reference position and the uppermost end of the connecting region corresponding to the measurement object and converting the number of pixels obtained by counting into a distance, the measurement target is measured from the belt suction surface 21a. The distance to an object (the uppermost floating sheet or the upper surface of the sheet bundle) can be calculated.

Further, from the number of pixels from the lower end of the second connecting region to the upper end of the lowermost connecting region extracted from the image taken by the image sensor during the levitation process or the suction process, the distance between the levitation top sheet and the sheet bundle is obtained. Information can be obtained. Further, the distance between the top levitation sheet and the second levitation sheet can be calculated from the number of pixels from the lower end of the second connection region to the upper end of the third connection region. From these distances, the floating state of the seat can be grasped, and the air volume of each air (floating air, side air, etc.) of the blower 17 can be adjusted.

Further, not only the vertical distance between the objects but also, for example, information on whether or not the top sheet is adsorbed on the belt suction surface is also obtained by image processing the image taken by the image sensor 31. Can be obtained based on. Specifically, whether or not the top sheet is adsorbed on the belt suction surface is determined by counting the pixels in the vertical direction of the uppermost connecting region and whether or not the number of pixels obtained by counting is equal to or greater than the threshold value. Information can be obtained. When the top sheet is not adsorbed on the belt adsorption surface 21a, the uppermost connecting region is composed only of the reflected light from the belt adsorption surface 21a, so that the pixels in the vertical direction of the uppermost connecting region The number is below the threshold. On the other hand, when the uppermost sheet is adsorbed on the belt suction surface 21a, the uppermost connecting region is the reflected light from the belt suction surface and the reflected light from the uppermost sheet adsorbed on the belt suction surface 21a. Since it is composed of, the number of pixels in the vertical direction is equal to or greater than the threshold value. As a result, it is possible to obtain information on whether or not the top sheet is sucked on the belt suction surface 21a from the number of pixels in the vertical direction of the top connecting region. From the information on whether or not the top sheet is adsorbed on the belt suction surface 21a obtained from the image taken by the image sensor 31, the floating state of the sheet can be grasped, and each air of the blower 17 (floating air, The air volume of side air, etc.) can be adjusted. It can also be used to control switching from the suction process to the separation process.

Next, specific control based on the image captured by the image sensor 31 will be described.
In the present embodiment, the following three controls are performed based on the image captured by the image sensor 31. That is, elevating control of the elevating device 19 for positioning the upper surface of the sheet bundle at the optimum levitation position, air volume adjustment control for adjusting the air volume of each air of the blower device 17, and driving of the suction belt 21 to suck the sheet on the suction belt 21. It is a belt feeding control that starts feeding. However, the control based on the image captured by the image sensor 31 is not limited to these.
First, the elevating control of the elevating device 19 for positioning the upper surface of the toe bundle at the optimum ascent position will be described.

FIG. 12 is a flow chart of an initial operation (control of the elevating device 19) based on a captured image of the image sensor 31.
First, the control unit 66 turns on the light source 32 (S1) when the sheet bundle is set in the storage tray 10. The setting of the sheet bundle on the storage tray 10 can be performed, for example, by detecting the attachment / detachment of the storage tray 10. Next, an image is taken by the image sensor 31, and the taken image is subjected to the image processing shown in FIG. 11 by the image processing unit 69 to calculate the distance L from the belt suction surface 21a to the upper surface of the sheet bundle (S3). .. Specifically, the image processing unit 69 performs image processing to extract a connected region. At this time, when the number of sheet bundles mounted on the sheet mounting table 11 is small and the upper surface of the sheet bundle is below the image pickup range of the image pickup device, the connecting region to be extracted is from the belt suction surface 21a. There is only one connecting area composed of the reflected light of. On the other hand, when the number of sheet bundles mounted on the sheet mounting table 11 is large, the upper surface of the sheet bundle falls within the imaging range of the image pickup device, and the extracted connecting region is composed of the reflected light from the belt suction surface 21a. There are two connecting regions, one is the connecting region and the other is the connecting region composed of the reflected light from the upper part of the sheet bundle.

Next, when two connected regions are extracted, the pixels from the lower end of the uppermost connected region to the upper end of the bottom (second connected region) are counted, and the number of images obtained by counting is counted. Is converted into a distance to calculate the distance L from the belt suction surface 21a to the upper surface of the sheet bundle. When the calculated distance L is less than the specified distance Le (No in S4), it is determined that the sheet is overloaded on the sheet mounting table 11, and the upper controller of the image forming apparatus 100 is overloaded. Notify that (S5). Upon receiving the notification from the sheet feeding device 200 that the sheet is overloaded, the host controller 67 displays on the display unit 122 of the operation unit 124 that the sheet stored in the storage tray 10 is overloaded, and stores the sheet. Prompt to reset the sheet bundle to the tray 10. The specified distance Le may be the same as the distance Ls between the belt suction surface 21a and the upper surface of the sheet bundle at the optimum levitation position, or may be shorter than the distance Ls.

When the sheets are fed in the overloaded state, the distance between the belt suction surface 21a and the upper surface of the sheet bundle is too short, and the sheets do not float properly in the levitation process or the suction process, and a plurality of sheets are suction belts. There is a risk of double feeding due to adsorption to. Therefore, by detecting overloading and prompting the user to reset the sheet bundle in the case of overloading, it is possible to prevent the occurrence of double feeding.

On the other hand, when the distance L is equal to or greater than the specified distance Le, or when only one connecting region is extracted and the distance L is not calculated (YES in S4), the control unit 66 uses the elevating drive motor of the elevating device 19. 65 is driven to raise the seat mounting table 11 (S6). When only one connection region is extracted and the distance L is not calculated, the upper surface of the sheet bundle is located below the image pickup range of the image pickup device 31. Therefore, the distance between the belt suction surface 21a and the upper surface of the sheet bundle is sufficiently farther than the specified distance Le than when the distance L is calculated, and is equal to or greater than Le. Therefore, even when only one connecting region is extracted and the distance L is not calculated, the seat mounting table 11 is raised.

In this way, when the raising / lowering control for raising the seat mounting table 11 and positioning the upper surface of the sheet bundle at the optimum levitation position is started, the image sensor 31 again performs imaging. Then, the image taken by the image processing unit 69 is processed, and the distance L from the belt suction surface 21a to the upper surface of the sheet bundle is calculated based on the processed image (S7). When the calculated distance L is equal to or greater than the distance Ls when the upper surface of the sheet bundle is located at the optimum floating position from the belt suction surface 21a, or when there is only one connecting region and the distance L cannot be calculated (YES in S8). Again captures an image with the image pickup element 31 to calculate the distance L (S7), and checks whether or not the calculated distance L has reached the distance Ls (S8).

On the other hand, when the distance L is equal to or less than the distance Ls when the upper surface of the sheet bundle is located at the optimum levitation position from the belt suction surface 21a and the upper surface of the sheet bundle reaches the optimum levitation position (YES in S8), the lifting device 19 The drive of the elevating drive motor 65 is stopped, the ascent of the seat mounting table 11 is stopped (S9), and the light source 32 is turned off (S10).

The optimum levitation position is the upper surface position of the sheet bundle in which the upper sheet of the sheet bundle can be appropriately floated by air, and the optimum levitation position is the condition (paper type and paper thickness) of the sheet set in the storage tray 10. It may be different depending on. In that case, a plurality of the distances Ls are stored in the storage means according to the conditions of the sheet. Then, when the sheet bundle is set in the storage tray 10, the display unit 122 of the operation unit 124 of the image forming apparatus is displayed to prompt the input of the sheet conditions (paper type and paper thickness). When the user inputs the sheet condition based on the content displayed on the display unit 122, the corresponding distance Ls is specified from the plurality of distance Ls stored in the storage means based on the input sheet condition. , The initial operation is performed based on the specified distance Ls. As an example, in the case of a sheet with sheet conditions that are difficult to float, such as a large sheet size and a thick paper, the value of the distance Ls becomes small and the optimum floating position is close to the belt suction surface 21a. On the other hand, in the case of a sheet with sheet conditions such that the sheet size is small and the paper thickness is thin, the value of the distance Ls becomes large, and the optimum levitation position is a position away from the belt suction surface 21a.

Next, the air volume adjustment control of the blower device 17 based on the captured image of the image pickup device 31 will be described.
FIG. 13 is an air volume adjustment flow diagram based on the captured image of the image pickup device 31, and FIG. 14 is a diagram showing the distance between the belt suction surface 21a and the top sheet P1 during the paper feed preparation operation.
The air volume adjustment control is performed during the paper feed preparation operation before the feeding operation (see FIG. 8).
In the paper feed preparation operation, the side blower 14a, the levitation blower 15, and the separation blower 16 of the blower 17 are driven to blow the levitation air, the side air, and the separation air, and the suction device 23 is driven to provide a spare sabaki. This is the action to be taken.

As shown in FIG. 13, when the blowing of the floating air, the side air, and the separated air and the generation of the suction air of the suction device are started (S11), the timer is started (S12) and the time measurement is started. At the same time, the light source 32 is turned on (S13), and an image is taken by the image sensor 31.

Next, the image processing unit 69 performs the image processing shown in FIG. 11 on the image taken by the image sensor 31 to calculate the distance Lt from the belt suction surface 21a to the upper surface of the sheet bundle (S14). Specifically, the number of pixels between the top connecting region corresponding to the belt suction surface 21a obtained by image processing by the image processing unit 69 and the second connecting region from the top corresponding to the top sheet. The distance Lt from the belt suction surface 21a to the upper surface of the sheet bundle is calculated based on the above. Then, an image is taken by the image pickup element 31 until the top sheet is attracted to the belt suction surface 21a of the suction belt and the distance Lt becomes 0, and the distance Lt from the belt suction surface 21a to the upper surface of the sheet bundle is calculated ( NO of S15 → S14).

As shown in FIG. 14A, immediately after the start of driving (t = 0), the top sheet of the sheet bundle is not floating, and the distance from the belt suction surface 21a to the upper surface of the sheet bundle at that time. Lt0 is the same as the distance Ls from the belt suction surface 21a to the sheet bundle when the upper surface of the sheet bundle is in the optimum levitation position.

After that, as shown in FIG. 14B, the uppermost sheet floats by the levitation air and the side air, and after ta, the uppermost sheet P1 rises to a position where the suction force of the suction device 23 acts.

After that, the top sheet is sucked to the belt suction surface 21a by the suction force of the suction device, and the distance from the belt suction surface 21a calculated by analyzing the captured image of the image pickup device 31 to the top sheet gradually increases. It gets shorter. Then, as shown in FIG. 14 (c), when the top sheet is adsorbed on the belt suction surface 21a, the distance Lt becomes 0.

In the present embodiment, it is determined that the distance Lt is 0 (that the top sheet is adsorbed on the belt suction surface 21a) as follows. That is, in the present embodiment, it is based on the number of pixels between the top connecting region obtained by processing the image captured by the image sensor 31 and the second top connecting region corresponding to the top sheet. The distance Lt is calculated. Until the top sheet is attracted to the belt suction surface 21a, the top connecting region is the belt suction surface, the second connection region from the top is the top sheet, and the top connecting region is used. The number of pixels between the top and the second connecting region gradually decreases. Then, as shown in FIG. 14C, when the uppermost sheet is adsorbed on the belt suction surface 21a, the uppermost connecting region becomes the uppermost sheet adsorbed on the belt suction surface and the belt suction surface, which is the second from the top. The connecting area of is the second sheet. Therefore, when the top sheet is attracted to the belt suction surface 21a, the number of counted pixels starts to increase from decrease. In this way, when the number of pixels to be counted changes from decreasing to increasing, it is determined that the distance Lt is 0 (the top sheet is adsorbed on the belt suction surface 21a).

Further, it may be determined that the distance Lt is 0 (that the top sheet is adsorbed on the belt adsorption surface 21a) as follows. That is, as described above, the position of the belt suction surface 21a is specified from the image captured by the image pickup device 31 before the start of blowing air, and the position of the specified belt suction surface 21a is stored in the storage means as a reference position. Then, the pixels between the reference position stored in the storage means and the upper end of the connecting region immediately below the reference position are counted, and when the counted number of pixels becomes 0, the distance Lt is 0 (belt suction surface 21a). It may be determined that the top sheet is adsorbed on the surface).

Further, as described above, when the number of pixels in the vertical direction of the uppermost connecting region exceeds the threshold value, it may be determined that the distance Lt is 0 (the uppermost sheet is adsorbed on the belt suction surface 21a).

When it is detected that the distance Lt between the belt suction surface 21a and the top sheet is 0 (the top sheet is sucked on the belt suction surface 21a) based on the image taken by the image sensor 31 (Yes in S15), the timer The time measurement is finished by stopping, and the light source 32 is turned off (S16).

When the time tx measured by the timer is earlier than the lower limit value Tb of the time range in which the uppermost sheet can be satisfactorily conveyed (YES in S17), the sheet is in a state of being easily lifted, and the second sheet is also a suction belt. There is a risk that it will be adsorbed on the surface and double feeding will occur. Therefore, in this case, the rotation speed of the levitation blower 15 is reduced to reduce the air volume of the levitation air (S18).

When the time tx measured by the timer is later than the upper limit value Tc of the optimum ascent time range in which the top sheet can be fed satisfactorily (NO in S17, YES in S19), the sheet is in a state where it is difficult to ascend. The sheet may not be sucked by the suction belt drive start timing. Therefore, in this case, the rotation speed of the levitation blower 15 is increased to increase the air volume of the levitation air (S20).

When the levitation air is adjusted, the suction by the levitation air, the separation air, the side air and the suction device 23 is stopped (S21), and when the uppermost sheet falls on the sheet bundle, the air volume is adjusted again.

On the other hand, when the time tx measured by the timer falls within the time range (tb ≤ tx ≤ tc) at which the top sheet can be satisfactorily conveyed (S17NO, S19NO), the rotation speed of the floating blower at that time is stored in the storage means. (S22). At the time of feeding operation, the levitation blower is driven by the rotation speed stored in this storage means.

The above-mentioned adjustment of the air volume is an example, and the rotation speed of the suction fan of the suction device 23 is adjusted to adjust the suction force, or the rotation speed of the side blower 14a is adjusted to adjust the air volume of the side air. You may. Further, the rotation speeds of the floating blower 15, the side blower 14a, and the suction fan may be adjusted.

Further, in adjusting the rotation speed of the levitation blower 15 or the like, the rotation speed may be adjusted by uniformly increasing or decreasing a certain specified rotation speed, or a delay (tx-tk) with respect to the optimum levitation time range of the measurement time tx. It is preferable to find the optimum number of revolutions within the optimum ascent time range based on the early (tb-tx). As a result, the optimum levitation time is the time from the start of air blowing to the suction of the top sheet on the suction belt with a single adjustment, compared to the case where the specified rotation speed is uniformly increased or decreased. Can be within range.

Further, for example, the relationship table between the measurement time tx and the appropriate rotation speed is stored in the storage means, and the rotation speed of the floating blower 15 or the like is appropriately determined based on the measurement time tx and the table stored in the storage means. It may be adjusted to a high rotation speed. Even with such an adjustment, the time from the start of air blowing to the suction of the top sheet to the suction belt can be set within the optimum floating time range by one adjustment.

Further, in the above, the time from the start of blowing the floating air until the top sheet is adsorbed on the belt suction surface is measured by a timer, but it is detected that the top sheet is adsorbed on the belt suction surface 21a. From the number of frames in the image, the time from the start of blowing the floating air to the suction of the top sheet on the belt suction surface may be obtained.

Further, in the above description, the air volume adjustment control is repeatedly performed until the time from the start of air blowing until the top sheet is adsorbed on the suction belt 21 is within the optimum levitation time range. If the adjustment is not within the optimum ascent time range, the device may be out of order, and the user may be urged to inspect the device.

Further, for example, the air volume may be adjusted based on the distance between the uppermost sheet and the second sheet when the uppermost sheet is adsorbed on the suction belt 21. If the distance between the top sheet and the second sheet when the top sheet is sucked on the suction belt is shorter than the specified value, the second sheet may also be sucked on the suction belt and double feeding may occur. , The rotation speed of the floating blower 15 and the suction fan is reduced to reduce the air volume.

Next, the belt feeding control based on the captured image of the image pickup device 31 will be described.
FIG. 15 is an operation flow diagram of the belt feed control, and FIG. 16 is a diagram showing the distance between the belt suction surface 21a and the top sheet P1 in the separation process.
When the top sheet is sucked on the belt suction surface 21a of the suction belt, the belt feeding control is started. Whether or not the top sheet is adsorbed on the belt suction surface 21a may be determined based on the image taken by the image sensor 31, or after a predetermined time has passed from the start of blowing the floating air or the side air, the belt suction surface It may be determined that the top sheet is adsorbed on 21a.

In this way, when the top sheet is attracted to the belt suction surface 21a of the suction belt 21, the floating shutter member 24 is moved to the closed position to stop the blowing of the floating air and separate as shown in FIG. 16A. The drive of the blower 16 is stopped, or the shutter that shuts off the separation air is driven to shift to the separation process of stopping the blowing of the separation air.

After shifting to the separation process, the light source 32 is turned on (S31) and an image is taken by the image sensor 31. Then, the captured image is subjected to the image processing shown in FIG. 11 by the image processing unit 69 to calculate the distance Lu from the belt suction surface 21a to the second sheet (S32).

At this time, the uppermost connecting region obtained by processing the image taken by the image sensor 31 is composed of the belt suction surface 21a and the uppermost sheet sucked on the belt suction surface 21a. Therefore, the pixels between the reference position corresponding to the belt suction surface stored in the storage means and the upper end of the second connecting region from the top corresponding to the second sheet are counted and obtained by counting. The distance Lu is calculated by converting the number of pixels into a distance.

By stopping the blowing of the levitation air, the levitation sheets other than the top sheet adsorbed on the belt suction surface 21a fall by their own weight, and the distance calculated by the image processing unit 69 with the passage of time as shown in FIG. 16B. Lu gradually becomes longer. As shown in FIG. 16C, an image is taken by the image sensor until the calculated distance Lu becomes equal to or more than the separation secured distance Ld, and the captured image is processed to continue calculating the distance Lu (S33NO → S32).

Then, when the distance Lu becomes equal to or greater than the separation securing distance Ld (S33YES), the belt drive is started (S34) and the top sheet sucked on the belt suction surface 21a is fed. The separation securing distance Ld is equal to or greater than the distance L1 (see FIG. 9) between the belt suction surface 21a shown in FIG. 9 and the tip of the regulation plate 33.

As shown in FIG. 16B, when the second seat starts the belt drive at a separation securing distance of less than Ld and starts feeding the uppermost seat, as described above, the downstream side in the seat transport direction. At the part where the top sheet and the second sheet are in contact with each other, when the second sheet is subjected to the conveying force, the tip of the second sheet is conveyed without hitting the regulation plate 33 and is double-fed. May occur.

On the other hand, after the distance Lu between the belt suction surface 21a and the second sheet is equal to or more than the separation securing distance Ld and the distance between the belt suction surface 21a and the tip of the regulation plate 33 is L1 (see FIG. 9) or more, the suction belt 21 By starting the driving of, even if the conveying force is applied to the second sheet, the tip of the second sheet hits the regulation plate 33 and is not fed together with the uppermost sheet, so that double feeding is suppressed. ..

Further, the position of the belt suction surface 21a does not change in the vertical direction. Therefore, by calculating the distance Lu of the second sheet and setting the separation securing distance Ld with reference to the belt suction surface 21a, the second sheet is surely positioned below the regulation plate 33. The drive of the suction belt 21 can be started.

FIG. 17 is a diagram showing an example of a timing chart in continuous feeding. In the figure, A is the implementation period of the air volume adjustment control, B in the figure is the implementation period of the belt feed control, and C in the figure is the control execution period of the lifting device.

First, when the control unit 66 receives the feeding instruction from the image forming apparatus 100, the control unit 66 executes the paper feed preparation operation, and causes the floating blower 15, the side blower 14a, and the separation blower 16 at the number of rotations stored in the storage means. It is driven and the suction fan is driven at the number of revolutions stored in the storage means to generate floating air, side air, separation air and suction air. As a result, the upper sheet of the sheet bundle floats, and the uppermost sheet is adsorbed on the belt suction surface. While the paper feed preparation operation is being executed, the air volume adjustment control (A in the figure) shown in FIG. 13 is executed to adjust the rotation speed of the floating blower 15, and the adjusted rotation speed is stored in the storage means.

Next, when the floating air is adjusted to the optimum air volume in the paper feed preparation operation, the continuous feeding operation is started. In the first feeding in the continuous feeding operation, since the top sheet has already been sucked to the belt suction surface 21a in the paper feed preparation operation, the separation process (see FIG. 8C) is performed. Specifically, the shutter solenoid 28 is driven to close the levitation shutter member 24 to shut off the levitation air, and the belt feeding control (B in the drawing) shown in FIG. 15 is performed. Then, when the distance Lu between the belt suction surface 21a and the second seat becomes equal to or greater than the separation secured distance Ld in the belt feeding control, the feeding motor 68 is started to be driven, and the feeding process (FIG. 8 (d)). ) See).

During this feeding process, the elevating device 19 for locating the sheet bundle at the optimum levitation position is controlled based on the captured image (C in the figure). During this feeding process, the uppermost sheet is adsorbed on the belt suction surface 21a, so that the uppermost connecting region obtained by processing the image taken by the image sensor 31 is the belt suction surface 21a. It is composed of a top sheet adsorbed on the belt suction surface 21a. Therefore, during the feeding process, the pixels between the reference position corresponding to the belt suction surface 21a stored in the storage means and the upper end of the bottom connecting region corresponding to the sheet bundle are counted and counted. The obtained number of pixels is converted into a distance to calculate the distance L from the belt suction surface 21a to the upper surface of the sheet bundle. Next, when the calculated distance L is equal to or greater than the distance Ls when the upper surface of the seat bundle is located at the optimum levitation position from the belt suction surface 21a, the elevating drive motor 65 is driven to raise the seat mounting table 11. .. When the distance L calculated based on the image taken by the image sensor 31 becomes the distance Ls when the upper surface of the sheet bundle is located at the optimum levitation position from the belt suction surface 21a, the motor of the elevating drive motor is stopped. As a result, even if the number of sheets in the sheet bundle is reduced by continuous feeding, the upper surface of the sheet bundle can be positioned at the optimum levitation position, and the sheets can be levitation satisfactorily by levitation air or side air. ..

Next, after the sheet feeding is completed and the feeding motor 68 is stopped, the shutter solenoid 28 is stopped, the levitation shutter member 24 is opened, and levitation air is blown to the next sheet in the levitation process (FIG. 8). (See (a)), the suction process (see FIG. 8 (b)) is carried out. Then, the air volume adjustment control is executed when the levitation process and the suction process are carried out. In the air volume adjustment control at this time, the time from the start of the ascent process (stopping the solenoid 28 for the shutter) to the adsorption of the ascended top sheet to the belt suction surface is within the time range (tb ≦ tx) at which the sheet can be satisfactorily conveyed. Whether or not it is within ≦ tk) is monitored based on the image taken by the image sensor 31, and if it is not within the above time range, the rotation speed of the levitation blower 15 is adjusted and stored in the storage means. Update the rotation speed to the adjusted rotation speed.
Further, if it is not detected from the captured image that the surfaced top sheet is adsorbed on the belt suction surface even after a certain specified time, the sheet feeding is stopped as a feeding failure.

In FIG. 17, the suction fan continues to be driven from the start of the paper feed preparation operation to the end of the feeding, but the rotation of the suction fan is stopped at the same time as the feeding motor 68 is stopped, and the suction fan is sucked on the belt suction surface. When the feeding of the sheet is completed, the suction of the sheet to the belt suction surface 21a may be stopped. In this case, the drive of the suction fan may be restarted at the start of the levitation process in which the drive of the shutter solenoid 28 is stopped and the blowing of the levitation air is restarted, or the suction force of the suction fan acts on the floating top sheet. It may be the start of the suction process in which the top sheet that has risen to the position where the suction belt is to be sucked is sucked.

Further, in FIG. 17, an image is always taken and image processing is performed during the feeding operation. However, for example, when the elevating control during the feeding process is completed, the image taking of the image sensor is temporarily stopped. You may stop and pause the image processing.

In the above-described embodiment, an example in which the present invention is applied to the sheet feeding device 200 optionally attached to the image forming apparatus has been described, but the present invention can also be applied to the feeding unit 114 included in the image forming apparatus. .. Further, the present invention may be applied to the document feeding unit in the document automatic transport device 140.

Further, in the present embodiment, the floating top sheet is sucked by the suction belt and the top sheet is fed by the rotational drive of the suction belt by the suction force, but the top sheet is pushed to the pickup roller by the floating air. The top seat may be fed by the rotational drive of the pickup roller due to the frictional force between the pickup roller and the top seat.

What has been described above is an example, and has a unique effect in each of the following aspects.
(Aspect 1)
An air blowing means such as a blower 17 that blows air onto the seat bundle P loaded on the seat loading portion such as the seat mounting table 11 to raise the seat on the upper part of the seat bundle, and a supply for feeding the floating top sheet. In a sheet feeding device 200 provided with a feeding means such as a feeding unit 20 and an imaging means such as an image pickup element 31 for photographing a sheet floated by an air blowing means, the feeding means such as a belt suction surface 21a is fed. The imaging range of the imaging means is set so that the surface and at least the top sheet of the sheet bundle loaded on the sheet loading portion are photographed.
According to this, since at least the top sheet of the sheet bundle can be photographed by the imaging means, whether the top sheet (upper surface) of the sheet bundle has reached the optimum levitation position based on the image taken by the imaging means. Whether or not it can be detected. As a result, it is possible to eliminate the sensor that detects that the upper surface of the sheet bundle loaded on the seat loading portion has reached the optimum floating position, reduce the number of parts, and reduce the cost of the device. it can.
In addition, since the feeding surface that feeds the top sheet of the feeding means is also within the imaging range of the imaging means, it is possible to photograph the state of the surfaced sheet near the feeding surface, and the imaging means photographs. The air volume of the blowing means can be satisfactorily adjusted based on the image.

(Aspect 2)
In the first aspect, based on an image taken by an image pickup means such as an image pickup device 31, a bundle of sheets loaded on a seat loading portion such as a seat mounting table 11 is moved up and down toward a feeding means such as a feeding unit 20. It controls at least one of the moving means such as the device 19, the air volume adjustment of the air blowing means such as the blower 17, and the feeding control of the feeding means.
According to this, as described in the embodiment, movement control such as elevating control of a moving means such as an elevating device 19, air volume adjustment of an air blowing means such as a blower 17, and a feeding means such as a feeding unit 20. It is possible to reduce the number of parts and reduce the cost of the device as compared with the one in which at least one of the feeding controls is performed based on the detection results of different detection means.

(Aspect 3)
In the second aspect, the movement control of the moving means such as the elevating device 19 calculates the distance between the feeding surface such as the belt suction surface 21a and the upper surface of the sheet bundle based on the image taken by the imaging means such as the image sensor 31. Then, the means of transportation is controlled based on the calculated distance.
According to this, as described in the embodiment, the upper surface of the sheet bundle can be positioned at the optimum levitation position based on the image taken by the image pickup means such as the image pickup element 31.
Further, since the position of the feeding surface such as the belt suction surface 21a does not fluctuate, the sheet bundle is accurately positioned at the optimum floating position by calculating the distance between the feeding surface and the upper surface of the sheet bundle. be able to.

(Aspect 4)
In the second or third aspect, the air volume of the air blowing means such as the blower 17 is adjusted based on the image taken by the image pickup means such as the image sensor 31, and the air volume adjustment is performed on the image taken by the image pickup means. Based on this, the time from the start of air blowing of the air blowing means until the top sheet lifted by the air comes into contact with the feeding surface such as the belt suction surface 21a is measured, and based on the measured time, the air blowing means of the air blowing means Adjust the air volume.
According to this, as described in the embodiment, the air volume is adjusted so that the uppermost sheet of the sheet bundle can be brought into contact with the feeding surface such as the belt suction surface 21a within a time range in which the sheet can be transported well. It is possible to suppress the delay in feeding and the occurrence of double feeding.

(Aspect 5)
In the fourth aspect, the air volume adjustment is performed during the paper feed preparation operation before the start of feeding, and the air volume adjustment is repeated until the optimum air volume is obtained.
According to this, the feeding operation can be performed with the optimum air volume.

(Aspect 6)
In the fourth or fifth aspect, the air volume adjustment is a process of blowing air on the sheet bundle in the feeding operation to float the uppermost sheet and bring it into contact with the feeding surface such as the belt suction surface 21a (the floating process and suction in the present embodiment). Process) at the time.
According to this, the air volume can be adjusted in the paper feeding operation.

(Aspect 7)
In the fifth or sixth aspect, the air volume adjusted by the air volume adjustment is stored in the storage means, and based on the air volume stored in the storage means, air is blown to the sheet bundle to raise the uppermost sheet to raise the belt suction surface 21a. The process of contacting the feed surface (the levitation process and the suction process in the present embodiment) is performed.
According to this, the air volume of the blowing means such as the blower 17 is adjusted to the air volume adjusted by adjusting the air volume, and air is blown to the sheet bundle to raise the uppermost sheet and contact the feeding surface such as the belt suction surface 21a. The process of making it can be carried out.

(Aspect 8)
In any of aspects 4 to 7, the distance between the feeding surface such as the belt suction surface 21a and the raised top sheet is calculated from the image taken by the image pickup means such as the image sensor 31, and based on the calculated distance. Detects contact of the top sheet with the feeding surface.
According to this, as described in the embodiment, the distance between the feeding surface such as the belt suction surface 21a and the raised top sheet is gradually shortened, and when the top sheet comes into contact with the feeding surface, the distance is reached. Becomes 0. Therefore, the contact of the uppermost sheet with the feeding surface can be satisfactorily detected based on the distance between the feeding surface calculated from the image taken by the image pickup means such as the image sensor 31 and the raised top sheet. ..

(Aspect 9)
In any one of aspects 1 to 8, the feeding means such as the feeding unit 20 sucks the floating top sheet onto the feeding surface such as the belt suction surface 21a, and feeds the top sheet.
According to this, the top sheet adsorbed on the feeding surface can be fed by moving the surface of the feeding surface.

(Aspect 10)
In the ninth aspect, the feeding control of the feeding means such as the feeding unit 20 is performed based on the image taken by the imaging means such as the image sensor 31, and the feeding control such as the belt feeding control is performed. The distance between the feed surface and the second sheet is constant based on the image taken by the imaging means during the separation process in which the floating sheet is dropped after the top sheet is adsorbed on the feed surface such as the belt suction surface 21a. When it is detected that the distance is more than the distance, the top sheet adsorbed on the feeding surface is fed.
According to this, as described in the embodiment, it is possible to suppress the occurrence of double feeding.
Further, since the position of the feeding surface such as the belt suction surface 21a does not change, the distance between the feeding surface and the second sheet is calculated so that the second sheet can accurately suppress the double feeding. It is possible to detect that the sheet has fallen.

(Aspect 11)
In any of aspects 1 to 10, the feeding of the belt suction surface 21a and the like specified based on the image taken by the image pickup means such as the image pickup element 31 in a state where the air blowing by the air blowing means such as the blower 17 is stopped. The position of the surface is stored in the storage means.
According to this, as described in the embodiment, even when the top sheet comes into contact (adsorption) with the feeding surface such as the belt suction surface 21a and it is difficult to identify the feeding surface from the image taken by the imaging means. By reading the position of the feeding surface from the storage means, the position of the feeding surface can be specified, and the distance to the measurement target with the feeding surface as a reference can be calculated.

(Aspect 12)
In an image forming apparatus including an image forming means such as an image forming unit 110 that forms an image on a sheet and a sheet feeding device that feeds the sheet toward the image forming means, the sheet feeding device is described in aspects 1 to 1. 11 Any sheet feeding device was used.
According to this, the cost of the device can be reduced.

10: Storage tray 11: Seat mounting table 12: Front blower 13: Side fence 14: Side blower 14a: Side blower 15: Floating blower 15a: Floating nozzle 16: Separation blower 16a: Separation nozzle 17: Blower 18: Air Chamber 18a: Floating air chamber part 18b: Separation air chamber part 19: Elevating device 20: Feeding unit 21: Suction belt 21a: Belt suction surface 23: Suction device 24: Floating shutter member 28: Shutter solenoid 30: Imaging device 31 : Imaging element 32: Light source 33: Restriction plate 65: Lifting drive motor 66: Control unit 68: Feeding motor 69: Image processing unit 100: Image forming device 110: Image forming unit 114: Feeding unit 122: Display unit 123: Operation panel 124: Operation unit 140: Document automatic transfer device 200: Sheet feeding device

Japanese Patent No. 6347066

Claims (12)

An air blowing means that blows air onto a bundle of seats loaded on the seat loading portion to raise the seat above the bundle of seats.
The means of feeding the surfaced top sheet and
In a sheet feeding device provided with an imaging means for photographing a sheet floated by the air blowing means.
The sheet feeding is characterized in that the imaging range of the imaging means is set so that the feeding surface of the feeding means and at least the uppermost sheet of the sheet bundle loaded on the sheet loading portion are photographed. Feeding device. In the sheet feeding device according to claim 1,
Control of the moving means for moving the sheet bundle loaded on the sheet loading unit toward the feeding means, based on the image taken by the imaging means, based on the image taken by the imaging means, and the air blowing. A sheet feeding device characterized in that the air volume of the means is adjusted and at least one of the feeding controls of the feeding means is performed. In the sheet feeding device according to claim 2,
The movement control of the moving means calculates the distance between the feeding surface and the upper surface of the sheet bundle based on the image taken by the imaging means, and controls the moving means based on the calculated distance. A sheet feeding device characterized by that.
A sheet feeding device characterized by this. In the sheet feeding device according to claim 2 or 3.
The air volume of the air blowing means is adjusted based on the image taken by the imaging means.
The air volume adjustment measures the time from the start of air blowing by the air blowing means until the top sheet surfaced by the air comes into contact with the feeding surface based on the image taken by the imaging means. A sheet feeding device characterized in that the air volume of an air blowing means is adjusted based on the measured time. In the sheet feeding device according to claim 4,
The air volume adjustment is performed during the paper feed preparation operation before the start of feeding.
The sheet feeding device, characterized in that the air volume adjustment is repeatedly performed until the optimum air volume is obtained. In the sheet feeding device according to claim 4 or 5.
The sheet feeding device is characterized in that the air volume adjustment is performed during the process of blowing air onto the sheet bundle in the feeding operation to raise the top sheet and bring it into contact with the feeding surface. In the sheet feeding device according to claim 5 or 6.
The air volume adjusted by the air volume adjustment is stored in the storage means and stored.
A sheet feeding device characterized in that a process of blowing air onto the sheet bundle to levitate the top sheet and bring it into contact with the feeding surface is performed based on the air volume stored in the storage means. In the sheet feeding device according to any one of claims 4 to 7.
The distance between the feeding surface and the raised top sheet is calculated from the image taken by the imaging means, and the contact of the top sheet with the feeding surface is detected based on the calculated distance. Sheet feeding device. In the sheet feeding device according to any one of claims 1 to 8.
The sheet feeding device is a sheet feeding device, characterized in that the floating top sheet is adsorbed on the feeding surface and the top sheet is fed. In the sheet feeding device according to claim 9,
The feeding control of the feeding means is performed based on the image taken by the imaging means.
The feeding control is based on the image taken by the imaging means during the separation process of dropping the floating sheet after the top sheet is adsorbed on the feeding surface, and the feeding surface and the second sheet. A sheet feeding device characterized in that when it is detected that the distance between the two is more than a certain distance, the feeding of the top sheet adsorbed on the feeding surface is started. In the sheet feeding device according to any one of claims 1 to 10.
A sheet feeding device characterized in that the position of the feeding surface specified based on an image taken by the imaging means is stored in the storage means in a state where the blowing of air by the air blowing means is stopped. An image forming means for forming an image on a sheet and
In an image forming apparatus including a sheet feeding device that feeds a sheet toward an image forming means,
An image forming apparatus according to claim 1, wherein the sheet feeding device according to any one of claims 1 to 11 is used as the sheet feeding device.