JP2001206573A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeder that stably separates transfer media at feeding and easily guides a blast between them, and particularly, can separate even various types of transfer medium of different thicknesses continuously constantly and feed them stably. SOLUTION: This paper feeder is so designed that a blowing means 23 blows wind over the leading edges of transfer media piled on a stacker 5a, 5b from the direction of feeding to separate the transfer media, and a feed belt 7 having a suction means 6 above is driven to feed it when effecting suction on the topmost transfer medium. A pressurizing means 27 is arranged on the upstream side of the suction means 6 in the feed direction of the transfer media so as to apply pressure to top places of the transfer media on both sides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder provided in an image forming apparatus such as a copying machine and a printer.
In particular, the present invention relates to a sheet feeding device that sucks a plurality of transfer materials stacked on a stacker by a suction belt and feeds the transfer materials to an image forming unit at a high speed.

[0002]

2. Description of the Related Art There is known a paper feeder for feeding a transfer material to an image forming apparatus or an image forming section one by one at a high speed. For example, air is blown by a blowing means such as a blower toward a front edge of a plurality of transfer materials stacked on a stacker or the like. The transfer material is separated at substantially equal intervals by separating the transfer material, and one of the uppermost surfaces of the transfer material is sucked by a transport belt provided with suction means. Thereafter, the transfer material is transported to the image forming unit by transporting the transport belt, and then image formation is performed.

The transfer material is aligned with the front end and one side as a reference surface on the stacker so as to match the size of the transfer material, and the other side and the rear of the transfer material are guided by a guide member provided on the stacker so as to be movable in the horizontal direction. The side surface is pressed to position the end. The size of the transfer material is specified by a size detection sensor or the like provided on the guide member by the lateral pressing by the guide member. Also, an actuator is provided so as to be in contact with the top surface of the transfer material in order to always keep the height of the top surface of the transfer material reduced by the consumed transfer material, and the actuator swings due to the decrease of the transfer material, The moving amount is detected by a detecting means such as a photo sensor, and the stacker is moved and adjusted by an elevator mechanism or the like based on this signal.

The mounting position of the actuator is provided in the vicinity of one side surface close to the reference surface side of the transfer material which does not need to be moved depending on the size of the transfer material.

[0005]

SUMMARY OF THE INVENTION
In view of miniaturization of the blowing means and the suction means, reduction of noise, and stability of the blowing quantity, it is desirable to reduce the blowing quantity and the suction quantity as much as possible and to reduce the number of installations. For this reason, the paper handling may not be stabilized simply by blowing air to the front edge of the transfer material. For example, when the transfer material has a smooth surface, the transfer materials are in close contact with each other, or the wind does not blow out to the rear end of the transfer material due to the pressing of the actuator, and flows to the other side surface where the actuator is not provided. In some cases.

Further, unless the transfer materials are separated and separated so that they penetrate back and forth with respect to the feeding direction of the transfer materials, the transfer materials may be multi-fed or fed obliquely. In particular, by forming the transfer material so as to have a mountain shape in the transport direction, there is an advantage that the suction to the suction belt provided with the suction means can be weakened.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a paper feeding device that stabilizes the separation of transfer materials during paper feeding and that easily guides air blowing between the transfer materials. That is the task. In particular, it is an object of the present invention to provide a paper feeder capable of always providing a constant transfer material separation even when a transfer material of a different thickness is used and capable of stably feeding the transfer material. I do.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is a paper feeder for sequentially feeding a plurality of transfer materials stacked on a stacker from the top, wherein the transfer material is stacked on the stacker. Air is blown to the front edge of the transfer material by the blowing means from the paper feed direction side of the transferred transfer material to loosen the transfer material, and the uppermost transfer material is adsorbed on a transport belt provided with a suction means positioned above. In a paper feeding device for feeding paper by driving the transport belt, a pressing means for pressing upper positions at both ends of the transfer material is provided at a position upstream of the suction means with respect to a feeding direction of the transfer material, and It is characterized in that air is blown from the leading edge to the trailing edge between the transfer materials.

Further, at least one of the pressing means is provided with a roller which is driven by the movement of the transfer material, and a movable guide for aligning a side edge of the transfer material with at least one of the pressing means. It is a substantially L-shaped pressing member provided on the member and moving in the up-down direction.

[0010] It is characterized in that the pressing means also serves as detecting means for detecting the position of the uppermost surface of the transfer material.

In such a configuration, even when the transfer materials having different paper thicknesses are used, the wind blows reliably between the transfer materials in the paper feed direction, and the transfer material is reliably separated from the transfer materials. A mountain shape is formed along. Next, the separated transfer material on the uppermost surface is adsorbed on a transport belt provided with a suction unit, and is sent to an image forming unit by driving the transport belt. Therefore, the transfer material can be reliably fed at a high speed without a double feed of the transfer material and without skew.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an image forming apparatus provided with the sheet feeding device of the present invention. The image forming apparatus 1 is roughly divided into a sheet feeding unit 2 for feeding a plurality of stacked transfer materials one by one, an image forming unit 3 for forming an image on the surface of the transfer material,
A stacking unit 4 for stacking transfer materials on which images have been formed in an orderly manner.

The paper supply unit 2 includes a stacker 5 on which transfer materials having different sizes are placed, and a suction unit 6 for picking up one of the uppermost transfer materials selected from the stacker 5.
And a lift 8 as an elevator mechanism that keeps the height of the transfer material constant at all times.

The paper feed unit 2 includes respective stackers 5.
a transport means 10 for transporting the transfer material selected by the transport belt 7 from a, 5b to a common outlet 9 provided in the paper feeding unit 2;

The image forming section 3 forms an image on the transfer material sent from the sheet feeding section 2 by a known image forming method, and for example, a corona charger 12 for uniformly charging the photosensitive drum 11 as a center. An exposure device 13 such as an LED array for exposing image data onto the photosensitive drum 11;
A developing device 14 for developing the electrostatic latent image formed on the photosensitive drum 11 with a developer, a transfer corona discharger 15 for transferring a toner image developed on the photosensitive drum 11 to a transfer material, A separating corona discharger 16 for peeling off the photosensitive drum 11, a cleaning device 17 such as a blade for removing toner remaining after transfer, an eraser lamp 18 for removing electricity from the surface of the photosensitive drum 11, and a transfer carrying an unfixed toner image A fixing device 19 for fixing the material.

The transfer material on which an image has been formed by a known image forming method is guided to a stacking section 4 having an upper tray 21 and a lower tray 22 through a transfer material transport path 20, and the transfer materials are stacked neatly. Is done.

FIG. 2 is an enlarged cross-sectional view of the paper feed unit 2, and FIG. 3 is a schematic diagram showing the vicinity of the uppermost surface of the transfer material loaded on the paper feed unit 2 as viewed from the direction of arrow A in FIG. . 4 and FIG.
1 shows a schematic view of the air outlet as viewed from the arrow B direction. In the drawing, a paper feeding unit 2 includes a blowing unit 23 that blows wind toward a leading edge of a loaded transfer material as a paper feeding unit, and a detection unit that detects a height of the transfer material consumed by image formation. 24, a transport belt 7 provided with a suction unit 6 for sucking the upper surface of the transferred transfer material, and a pressing unit 27 for pressing the uppermost surface of the transfer material.

The blower 23 blows air from a blower port 30 provided at a position facing the front edge of the transfer material via a duct 29a by a blower 28 provided in the paper feeding device 2 or the like. In the duct 28, for example, there is provided a switching plate (not shown) that opens and closes and controls so as to blow air only to a stacker corresponding to the selected size. Blow port 30
Has a shape that is sprayed substantially toward the center of the front edge of the transfer material, as shown in FIG. 4, and preferably has a hole 25a that is sprayed near the center, and is weakened toward both ends and sprayed toward the upper edge. And a hole 25b.

The detecting means 24 contacts the transfer material on the uppermost surface of each of the stackers 5a and 5b as shown in FIG.
32 that swings around the center, and a sensor 33 such as a photo sensor that detects the swing of the actuator 32
And a lift 34 for moving the stackers 5a and 5b up and down according to the signal. The lift 34 has, for example, a nut 35 fixed to each of the four positions of the stackers 5a and 5b, and a screw 36 provided on the apparatus main body side is screwed to the nut 35, and the stacker 5a is 5b is controlled. A driven roller 37 that rotates in the paper feeding direction is provided at the tip of the actuator 32 that comes into contact with the transfer material in order to reduce the resistance due to the feeding of the transfer material. In addition, the position of the uppermost surface of the transfer material is set to be an appropriate height for the transfer material to be separated, and the actuator 32 detects a decrease in the height of the transfer material consumed by image formation. The lift 8 is driven based on the signal.

The transport belt 7 includes a single-width belt that extends over the entire width of the maximum-size transfer material or a plurality of endless belts that are appropriately divided in the width direction of the transfer material and arranged in parallel. And a suction means 6 for transporting the transfer material so as to adhere to the transport belt 7. The suction means 6 is provided with a plurality of intake ports at predetermined locations on a peripheral surface of the transport belt 7, and a suction box 41 having a large number of intake holes on a lower surface arranged in a space surrounded by the transport belt. The transfer material is connected to a suction means such as a blower via a duct 29b, and air is sucked from these air intake ports toward the inside of the conveyance belt 7 to convey the transfer material in close contact with the peripheral surface of the conveyance belt 7.

The transfer belt 7 may be any type as long as it can suck and transfer the leading end of the transfer material by belt driving. In the embodiment, the transfer belt 7 is provided such that a suction box is attached to the top end of the transfer material. The transfer material is provided so as to be long enough to feed the suctioned transfer material to the supply roller 38.

As shown in FIGS. 5 and 7, the pressing means 27 is provided at a position upstream of the conveyor belt 7 with respect to the feeding direction of the transfer material so as to press the upper side of both ends of the transfer material.
The pressing of the pressing means 27 is preferentially adjusted by the height detecting means 24 of the transfer material.
Is provided so as to be higher than the contact position of the transfer material, and when the transfer material is loosened by the wind of the air blowing means 23, the transfer material is pressed so as not to float further. The pressing of the pressing means 27 acts so that the wind from the blowing means 23 blows from the leading edge to the trailing edge between the transfer materials.

As shown in FIG. 5, the positional relationship of the pressing means 27 is such that it is located between the actuator 32 and the rear end of the conveyor belt 7, and is located above the detection of the height position of the transfer material of the actuator 32. Is preferred. Further, a driven roller 34 that is driven by the movement of the transfer material is provided on at least one of the pressing units 27. This pressing means 27
“a” is preferably provided on the side where the actuator 32 is located, and acts to minimize the frictional resistance due to the movement of the transfer material and to prevent the transfer material from skewing or being damaged.

As shown in FIG. 3, reference numeral 39a denotes a slidable guide member for aligning the side edges of the transfer material in accordance with the size of the transfer material. The guide member 39a guides the side edges of the transfer material. Is provided with a substantially L-shaped pressing member 27b that moves vertically. FIG. 6A is a view of the guide member 39a viewed from above, and FIG.
9a is shown in a view from the side. As shown in the figure, the pressing means 27b is provided so as to be swingable about the fulcrum 26, and urges the transfer material in the direction of pressing the transfer material by the action of the spring means 40 or the weight of the pressing means. The transfer material is placed on the transfer material placing table, and after the guide 39a is pressed against the side surface of the transfer material, the transfer material placing table is lifted up by the lift 34, so that the projection 41 of the pressing means 27b presses the transfer material. .

In particular, the pressing means 27a can also serve as the detecting means 24 for detecting the position of the uppermost surface of the transfer material.
Thereby, the number of parts can be omitted.

The operation of the above configuration will be described. The transfer material is stacked on the stackers 5a and 5b, and the guide members 39a and 39b are moved to match the size of the transfer material. At this time, pressing means 27b provided on a guide member for aligning the side surfaces of the transfer material presses the transfer material. The transfer material set in the paper feeding unit 2 is moved by the lift 34 to a position where the stackers 5a and 5b swing the actuator 32 as the detection means 24 in preparation for image formation.
The position of the uppermost transfer material is determined.

In order to form a well-known image, a blower 2
3 and a blower 28 for operating the suction means 6 are operated,
The blowing unit 23 blows air from the blowing port 30 toward the front edge of the transfer material, and the suction unit 6 sucks the leading end portion of the transfer material on the uppermost surface and causes the transfer belt 7 to adsorb it. At this time, the blowing of the air by the blowing means 23 is performed by the pressing means 27a and 27b which press the upper positions on both sides of the transfer material, as shown in the perspective view of FIG. Blow-through from the front edge to the rear edge, the central portion of the transfer material is lifted in the direction in which the transport belt 7 is located, and is attracted to the transport belt by suction of the suction means.

Next, when printing is started, the transfer material is conveyed from the paper supply unit 2 to the image forming unit 3 via the supply roller 38 which is constantly driven at the timing of image formation, and the well-known image formation is performed. This is performed in the forming unit 2, and passes through the fixing device 19 and is accumulated in the accumulation unit 4. The transport belt 7 temporarily stops at the timing when the first transfer material is transported by the driving of the paper feed roller 38, and the next transfer material is moved by the wind from the blowing unit 23 and the action of the pressing units 27a and 27b. , The central portion of the transfer material is lifted by blowing from the front end to the rear end, and is attracted to the transport belt 7 to be on standby. Next, at a predetermined distance from the rear end of the first transfer material, the next transfer material
To 8. By repeating this operation, high-speed image formation is achieved.

[0029]

According to the present invention, even in the case where transfer materials having different paper thicknesses are used, the wind blows between the transfer materials in the paper feeding direction to reliably separate the transfer materials, and the transfer material is piled up along the paper feeding direction. A mold is formed. Next, the separated transfer material on the uppermost surface is adsorbed on a transport belt provided with a suction unit, and is sent to an image forming unit by driving the transport belt. Therefore, the transfer material can be reliably fed at a high speed without a double feed of the transfer material and without skew.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus provided with a sheet feeding device according to the present invention.

FIG. 2 is a schematic sectional view of a sheet feeding device according to the present invention.

FIG. 3 is a schematic sectional view as seen from the direction of arrow A in FIG. 2;

FIG. 4 is a diagram showing an air outlet of an air blowing means as viewed from the direction of arrow B in FIG. 2;

FIG. 5 is a side view showing an example of a pressing unit.

FIG. 6A is a top view showing another embodiment of the pressing means. (B) The side view which shows another Example of a pressing means.

FIG. 7 is a perspective view showing a transfer material being loosened in a paper feeding unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper feed part 3 Image forming part 4 Stacking part 5a, 5b Stacker 6 Suction means 7 Conveying belt 8 Lift 9 Exit 10 Conveying means 11 Photosensitive drum 12 Corona charger 13 Exposure device 14 Developing device 15 Corona discharger 16 Separating corona discharger 17 Cleaning device 18 Erase lamp 19 Fixing device 20 Transfer material transport path 21 Upper tray 22 Lower tray 23 Blowing means 24 Detecting means 25a, 25b Hole 26 Support points 27, 27a, 27b Pressing means 28 Blowers 29a, 29b Duct 30 Blow port 31 Support point 32 Actuator 33 Sensor 34 Follower roller 35 Nut 36 Screw 37 Follower roller 38 Supply roller 39a, 39b Guide member 40 Spring means 41 Intake box

Claims (4)

[Claims] 1. A sheet feeding device for sequentially feeding a plurality of transfer materials stacked on a stacker from above, wherein the transfer material stacked on the stacker is transferred from the sheet feeding direction side by a blowing unit. A paper feed device for blowing the wind to the front edge of the material to loosen the transfer material, adsorbing the uppermost transfer material to a transport belt provided with suction means positioned above, and feeding the paper by driving the transport belt; A pressing means for pressing the upper end of both ends of the transfer material is provided at a position upstream of the suction means with respect to the feeding direction of the transfer material, so that the air blown by the air blowing means blows from the front edge between the transfer materials to the rear edge. A sheet feeding device, which is provided. 2. A sheet feeding device according to claim 1, wherein at least one of said pressing means is provided with a roller driven by the movement of the transfer material. 3. A substantially L-shaped pressing member which is provided on at least one of said pressing means and is provided on a movable guide member for aligning a side edge of a transfer material and moves in a vertical direction. 2. The paper feeding device according to 1. 4. The sheet feeding device according to claim 1, wherein said pressing means also serves as a detecting means for detecting a position of an uppermost surface of said transfer material.