CN112499348B

CN112499348B - Sheet feeding device and image forming apparatus

Info

Publication number: CN112499348B
Application number: CN201910869413.6A
Authority: CN
Inventors: 梁健超
Original assignee: Konica Minolta Technology Development Wuxi Co Ltd
Current assignee: Konica Minolta Technology Development Wuxi Co Ltd
Priority date: 2019-09-16
Filing date: 2019-09-16
Publication date: 2022-10-04
Anticipated expiration: 2039-09-16
Also published as: CN112499348A

Abstract

The present invention relates to a paper feeding device and an image forming apparatus, wherein the paper feeding device comprises: an air supply part which is positioned on the side surface of the paper to be conveyed and supplies air to the paper to enable the paper to float; a suction unit which is positioned above the sheet and applies suction to the floating sheet; a conveying section which is located above the sheet, and which conveys the sheet along a predetermined conveying path after the sheet is attracted to the conveying section by an attraction section, the conveying section further comprising: and a sheet pushing mechanism located at a rear end side of the sheet to be conveyed, the sheet pushing mechanism being movable in a conveying direction and adapted to regulate the sheet in a floating state to align the sheet. From this, can promote the regulation effect, reduce the degree of difficulty of carrying out the regulation to the paper, avoid the crisscross paper that leads to being in lower floor's position to float, perhaps, lead to the paper that is in lower floor's position to remove along with the transport direction opposite direction.

Description

Sheet feeding device and image forming apparatus

Technical Field

The present invention relates to a paper feeding device and an image forming apparatus, and more particularly to a paper feeding device and an image forming apparatus capable of regulating a floating sheet of paper.

Background

In a conventional sheet feeding apparatus, a regulating mechanism having a rear-end regulating plate is provided at a trailing end of a sheet in a tray for placing the sheet. The regulating plate is movable in a sheet carrying direction for regulating the sheet so as to align the sheet with a front end of the sheet supply device to reduce instability of the sheet supply device during sheet feeding.

With the continuous development of printer technology, paper feeding speed is faster and faster, and the variety of paper applications is increasing day by day. The method for manufacturing the large-capacity paper box or the large-size paper seed and other standard boards is difficult to meet the standard requirements. Due to the fact that friction force exists between adjacent paper sheets, the paper sheets are pushed by the regulating plate to be fixed easily, and therefore the paper sheets are arched, or the tail ends of the paper sheets are crushed.

Fig. 1 is a schematic structural view of a paper feeding device 10, and referring to fig. 1, the paper feeding device 10 has: an air supply part which is positioned on the side surface of the paper to be conveyed and supplies air to the paper to enable the paper to float; a suction unit 11 positioned above the sheet and configured to apply a suction force to the floating sheet; a conveying section 12 located above the sheet, the suction section 11 sucking the sheet to the conveying section 12 and conveying the sheet along a predetermined conveying path; a drawer 30, said drawer 30 being adapted to place sheets to be transported, the sheets being placed in said drawer 30 in a stacked manner; a regulation plate 32, the regulation plate 32 being located on a rear end side of the sheet, a surface of the regulation plate 32 being perpendicular to a surface of the sheet.

Due to the above-mentioned friction force, the difficulty of the regulating plate 32 in pushing the sheets is great, and thus the regulating plate 32 has a poor regulating effect on the sheets, causing misalignment of the sheets in a stacked state and interleaving among the sheets. The staggered position of the paper causes not only the floating of the paper to be transported but also the floating of the paper at the lower position of the paper to be transported, and a plurality of pieces of paper are then attracted to the transporting part 12 by the attraction part 11, so that the operation of the transporting part 12 is easily stopped, and the operator needs to clean the paper on the transporting part 12 before transporting the paper again.

Referring to fig. 2, the sheet position is staggered such that, after the sheet positioned at the lower position of the sheet to be conveyed floats, the sheet positioned at the lower position in the floating state is easily moved in the direction opposite to the conveying direction x under the influence of the wind force applied by the wind blowing part.

Therefore, the paper feeding device is still to be improved to improve the regulation effect and ensure the stability of paper feeding.

Disclosure of Invention

The present invention provides a paper feeding device, comprising: an air supply part which is positioned on the side surface of the paper to be conveyed and supplies air to the paper to enable the paper to float; a suction unit which is positioned above the sheet and applies suction to the floating sheet; a conveying section located above the sheet, the suction section sucking the sheet to the conveying section and conveying the sheet along a predetermined conveying path, the sheet feeding apparatus further comprising: and a sheet pushing mechanism located at a rear end side of the sheet to be conveyed, the sheet pushing mechanism being movable in the conveying direction and adapted to regulate the sheet in a floating state to align the sheet.

As a result of intensive studies by the inventors of the present invention, it has been found that the frictional force between sheets in a floating state is significantly reduced as compared with sheets in a stacked state. Therefore, the floating paper is regulated, the resistance is small, and the paper is easy to push so as to align.

The sheet in the floating state is regulated to align the sheets by providing a sheet advancing mechanism on the rear end side of the sheet to be conveyed and pushing the rear end of the sheet in the floating state in the conveying direction by the sheet advancing mechanism. From this, can promote the regulation effect, reduce the degree of difficulty of carrying out the regulation to the paper, avoid the crisscross paper that leads to being in lower floor's position to float, perhaps, lead to the paper that is in lower floor's position to receive the air-feeding part to influence to move along with the opposite direction of carrying direction.

In addition, in order to accurately adjust the relative position of the paper pushing mechanism and the paper to be conveyed before the regulation, the paper pushing mechanism can move along the conveying direction and the reverse direction of the conveying direction, so that the paper pushing mechanism is just at the rear end of the paper in a floating state, and the action force can be conveniently applied to the rear end of the paper to align the paper.

In the above paper feeding device, the paper feeding device may further include: a housing; the drawer is positioned in the shell and is suitable for placing paper to be conveyed; the paper pushing mechanism is located in the shell and arranged on the top wall of the shell.

The paper pushing mechanism is thereby positioned on the top wall of the casing, moves in the conveyance direction, and regulates the paper that floats from the inside of the drawer to the top of the drawer. The paper advancing mechanism is arranged on the top wall of the shell and can screen the paper states, and the paper in the floating state can be touched by the paper advancing mechanism, and the paper in the drawer and in the stacking state is difficult to touch by the paper advancing mechanism, so that the paper advancing mechanism only regulates the paper in the floating state, and the difficulty in regulating the paper is reduced.

In the above paper feeding device, the paper advancing mechanism may include: and a push plate having an open position and an evasive position for regulating the sheet.

Therefore, in the process of regulating the floating paper by the paper pushing mechanism, the pushing plate is adjusted to the unfolding position, so that the surface of the pushing plate is perpendicular to the surface of the paper, and the pushing force can be conveniently applied to the rear part of the paper by utilizing the surface of the pushing plate so as to align the paper. After the paper pushing mechanism finishes the regulation of the paper, the pushing plate is adjusted to the avoiding position, so that the surface of the pushing plate is parallel to the surface of the paper, the occupation of the pushing plate on the space is reduced, the paper pushing mechanism is prevented from interfering the floating process of the paper to be conveyed, and the paper pushing mechanism is prevented from interfering the conveying part to convey the paper along the preset conveying path.

In the above paper feeding device, a front plate may be further provided in a conveying direction of the paper to be conveyed, the front plate being located on a front end side of the paper, a surface of the front plate being perpendicular to a surface of the paper; the paper pushing mechanism pushes the paper in the floating state until the front end of the paper moves to the front plate.

Thus, the sheet pushing mechanism pushes the rear end of the sheet in a floating state to move the sheet forward. Because the front plate is located the paper front end side, and this front plate surface perpendicular to paper surface, consequently when the paper front end move to front plate department, the front end of each paper is on the coplanar, and correspondingly, the rear end of each paper also is on the coplanar to guarantee that the paper aligns, in order to promote the regulation effect.

In the above paper feeding device, the paper feeding device may further include: a paper information acquisition unit that acquires length information of a paper in a conveyance direction; a standard setting unit that sets a standard position of a rear end of the sheet based on the length information acquired by the sheet information acquiring unit; the paper pushing mechanism pushes the paper in the floating state until the rear end of the paper moves to the standard position.

Thus, the sheet pushing mechanism pushes the rear end of the sheet in a floating state to move the sheet forward. The standard setting unit sets a standard position of the rear end of the sheet based on the length information acquired by the sheet information acquiring unit. When the rear ends of the paper sheets move to the standard position, the paper sheet pushing mechanism stops pushing the paper sheets, so that the rear ends of the paper sheets are located at the same position, correspondingly, the front ends of the paper sheets are also located at the same position, and therefore the paper sheets are aligned, and the regulation effect is improved.

In the above paper feeding device, the paper advance mechanism is moved to a rear end side of the paper by a predetermined length based on the paper length information acquired by the paper length information acquisition unit, and the advance plate is moved to regulate the floating paper.

Thus, according to the paper length information acquired by the paper length information acquiring unit, the paper pushing mechanism is moved to the rear end side of the paper by a predetermined length by first moving the paper pushing mechanism in the conveying direction or in the reverse direction, and then the rear end of the paper is pushed in the conveying direction, so that the rear end of the paper can be prevented from being damaged by the paper pushing mechanism while the regulating effect is ensured, and the paper can be protected.

In the above paper feeding device, the paper feeding device may further include: the first sensor is arranged on the paper pushing mechanism and is suitable for judging whether paper exists below the paper pushing mechanism or not; the second sensor is arranged on the paper advancing mechanism and is suitable for judging whether the lower part of the paper advancing mechanism is the rear end of the paper or not; when the second sensor judges that paper exists and the first sensor judges that paper exists, the paper pushing mechanism moves backwards until the first sensor judges that no paper exists; the paper pushing mechanism moves forwards, and in the process of moving forwards, the second sensor judges that no paper exists and the first sensor judges that no paper exists; and when the second sensor judges that paper exists and the first sensor judges that no paper exists, the paper advancing mechanism stops moving forwards.

When the second sensor judges that paper exists and the first sensor judges that paper exists, the position of the paper pushing mechanism relative to the paper is too far forward, so that the paper pushing mechanism moves backwards until the first sensor judges that no paper exists. Thus, by the first sensor cooperating with the second sensor, the sheet advancing mechanism can be moved to a position appropriate for the rear end of the sheet before the sheet regulating operation is performed. The paper advancing mechanism further moves forward to regulate the paper until the second sensor judges that the paper exists and the first sensor judges that the paper does not exist, which indicates that the rear ends of the paper are pushed to be right below the second sensor, namely, the paper is aligned and the regulation operation is finished, so that the paper advancing mechanism stops moving forward at the moment. Therefore, the paper advancing mechanism stops advancing at proper time by the first sensor and the second sensor, and the phenomenon of paper arching or damage to the rear end of the paper can be avoided.

In the above paper feeding device, when the second sensor determines that there is no paper and the first sensor determines that there is no paper, the paper feed mechanism may move forward until the second sensor determines that there is paper and the first sensor determines that there is no paper.

When the second sensor judges that there is no paper and the first sensor judges that there is no paper, it indicates that the paper advancing mechanism is located at a certain distance from the rear end side of the paper, and thus the paper advancing mechanism can move forward at this time to push the rear end of the paper to align the paper. When the second sensor judges that paper exists and the first sensor judges that no paper exists, the rear end of each paper is pushed to the position right below the second sensor, namely, the paper is aligned, and the regulation operation is finished, so that the paper pushing mechanism stops moving forwards, on one hand, the alignment effect of the paper is ensured, and on the other hand, the phenomenon that the paper is arched or the rear end of the paper is damaged is avoided.

In the above paper feeding device, the paper feeding device may further include: a judging unit adapted to judge whether there is an operation of pushing the drawer into the housing; when the judging unit judges that the operation of pushing the drawer into the shell exists, the air supply part starts to supply air to enable the paper to float, and the paper pushing mechanism starts to regulate the paper in the floating state so as to enable the paper to be aligned.

When there is an operation of pushing the drawer into the housing, it is indicated that there is a possibility that the user adds paper to the drawer. Whether the operation of pushing the drawer into the shell exists or not is judged through the judging unit, after the judging unit judges that the operation of pushing the drawer into the shell exists, the air supply part starts to supply air to enable the paper to float, the paper advancing mechanism is started, and therefore the paper in the floating state is regulated, the newly added paper is aligned, all the paper is guaranteed to be aligned, in addition, the situation that the paper advancing mechanism repeatedly regulates the paper after the paper is aligned to cause energy waste can be avoided, and the efficiency of regulating operation of the paper advancing mechanism is improved.

Further, the reading device of the present invention can be applied to an image forming apparatus, and can provide the above-described effects.

Drawings

FIG. 1 is a schematic view of a sheet feeding apparatus in a state of carrying a sheet;

FIG. 2 is a schematic view of the sheet feeding apparatus shown in FIG. 1 in another state of carrying sheets;

FIG. 3 is a schematic view of a structure of a sheet feeding apparatus according to an embodiment of the present invention;

FIG. 4 is a schematic view of the movement of the sheet advancing mechanism of the sheet feeding apparatus shown in FIG. 3;

FIG. 5 is a schematic view of the structure of the paper advance mechanism shown in FIG. 3;

FIG. 6 is an enlarged partial view of the paper advance mechanism shown in FIG. 5;

FIG. 7 is a schematic diagram of the operation of the paper advance mechanism shown in FIG. 3;

fig. 8 is another operational schematic diagram of the paper advance mechanism shown in fig. 3.

Detailed Description

Fig. 3 is a schematic configuration diagram of the sheet feeding device 100 according to the embodiment of the present invention. Fig. 4 is a schematic diagram showing the movement of the sheet advancing mechanism 200 of the sheet feeding apparatus 100 shown in fig. 3.

Hereinafter, a specific configuration of the paper feeding device 100 of the present invention will be described in detail.

Referring to fig. 3, the paper feeding device 100 has: an air supply part which is positioned on the side surface of the paper to be conveyed and supplies air to the paper to enable the paper to float; a suction unit 110 which is positioned above the sheet and applies a suction force to the floating sheet; a conveying part 120 positioned above the paper, wherein the paper is sucked to the conveying part 120 by the suction part 110 and then conveyed along a predetermined conveying path; a sheet advancing mechanism 200, which is located at the rear end side of the sheet to be conveyed, as shown in fig. 4, the sheet advancing mechanism 200 being movable in the conveying direction x and the reverse direction thereof, and adapted to regulate the sheet in a floating state so as to align the sheet.

In this embodiment, the paper feeding device 100 transports paper in an air feeding mode.

The friction between the sheets in the floating state is significantly reduced compared to the sheets in the stacked state. Therefore, the floating paper is regulated, the resistance is small, and the paper is easy to push so as to align.

The sheet in the floating state is regulated to align the sheet by providing the sheet advancing mechanism 200 at the rear end side of the sheet to be conveyed and pushing the rear end of the sheet in the floating state in the conveying direction x by the sheet advancing mechanism 200. From this, can promote the regulation effect, reduce the degree of difficulty of carrying out the regulation to the paper, avoid the crisscross paper that leads to being in lower floor's position to float, perhaps, lead to the paper that is in lower floor's position to receive the air supply portion to influence and move along with carrying direction x opposite direction.

In addition, in order to accurately adjust the relative position of the paper advance mechanism 200 and the paper to be conveyed before the sheet is regulated, the paper advance mechanism 200 can move not only in the conveying direction x, but also in the direction opposite to the conveying direction x, so that the paper advance mechanism 200 is just at the rear end of the paper in a floating state, and a force can be applied to the rear end of the paper to align the paper.

The paper feeding apparatus 100 further includes: a housing (not shown); a drawer 300, said drawer 300 being located in said housing, said drawer 300 being adapted to place sheets to be transported, the sheets being placed in said drawer 300 in a stacked manner.

The housing has a top wall, a bottom wall, and a side wall between the top wall and the bottom wall. The top wall, the bottom wall and the side wall enclose a cavity.

The air blowing unit, the suction unit 110, the conveying unit 120, and the paper pushing mechanism 200 are all located in the casing.

The air supply parts are arranged on two sides in the shell and face the upper part of the paper stack, and at least one air supply part is arranged on one side of the two sides. The air supply part supplies air to the paper stack from the side surface, so that a plurality of paper sheets above the paper stack float.

The suction part 110 is provided on the top wall of the housing, and the number of the suction parts 110 is one or more. The suction portion 110 applies a suction force in a vertically upward direction to the sheet, so that the sheet continues to float upward until it comes into contact with the conveyance portion 120.

In this embodiment, the suction unit 110 applies a suction force to the sheet by wind power.

The number of the conveying members 120 is one or more. The conveying unit 120 includes a conveying gear and a timing belt sleeved on the conveying gear. The paper floats up to the timing belt under the attraction force applied by the attraction part 110, and the conveying gear rotates to drive the timing belt to move, so that the paper is conveyed along a predetermined conveying path.

The paper advance mechanism 200 is located in the housing and is disposed on the top wall of the housing.

Thus, the sheet pushing mechanism 200 is located on the top wall of the casing, moves in the conveyance direction x and in the reverse direction, and regulates sheets floating from the inside of the drawer 300 to the above of the drawer 300. Paper advancing mechanism 200 is provided on the top wall of the housing, and can screen the paper state, and since only the floating paper can be touched by paper advancing mechanism 200, and the paper stacked in drawer 300 is difficult to be touched by paper advancing mechanism 200, paper advancing mechanism 200 regulates only the floating paper, thereby reducing the difficulty in regulating the paper.

In this embodiment, the paper advance mechanism 200 includes: and a push plate 210, wherein the push plate 210 has an unfolding position and an avoiding position for regulating the paper.

Thus, during the regulation of the sheet in the floating state by the sheet advancing mechanism 200, the advancing plate 210 is adjusted to the deployed position so that the surface of the advancing plate 210 is perpendicular to the surface of the sheet, facilitating the pushing force to be applied to the rear portion of the sheet by the surface of the advancing plate 210 to align the sheet. After the paper pushing mechanism 200 completes the regulation of the paper, the pushing plate 210 is adjusted to the avoiding position, so that the surface of the pushing plate 210 is parallel to the surface of the paper, which helps to reduce the occupation of space by the pushing plate 210, avoid the paper pushing mechanism 200 from interfering with the floating process of the paper to be conveyed, and prevent the paper pushing mechanism 200 from interfering with the conveying part 120 to convey the paper along the predetermined conveying path.

The push plate 210 is also rotatable about an axis parallel to the sheet surface and perpendicular to the conveyance direction x.

Thus, during actuation of the paper advance mechanism 200, the advance plate 210 rotates about the axis such that the surface of the advance plate 210 is perpendicular to the surface of the paper to facilitate the advancement of the trailing end of the paper by the surface of the advance plate 210. After the sheet pushing mechanism 200 completes the sheet regulation, the pushing plate 210 rotates around the axis so that the surface of the pushing plate 210 is parallel to the surface of the sheet to reduce the space occupied by the pushing plate 210.

In other embodiments, the surface of the pushing plate 210 may be kept perpendicular to the surface of the paper, and after the paper pushing mechanism 200 completes the regulation of the paper, the pushing plate 210 is lifted to the avoiding position to avoid interfering with the conveyance of the paper by the conveying part 120.

In the process of regulating the floating paper by the paper advance mechanism 200, the paper advance mechanism 200 moves in the conveyance direction x or the reverse direction.

During the movement of the sheet advancing mechanism 200 in the conveying direction x or the direction opposite thereto, the sheet advancing mechanism 200 moves along the guide rail 290. The guide rail 290 prevents the moving direction of the sheet advancing mechanism 200 from being shifted.

The paper feeding device 100 may further include: a judging unit (not shown in the drawings) adapted to judge whether there is an operation of pushing the drawer 300 into the housing; when the judging unit judges that there is an operation of pushing the drawer 300 into the housing, the air supplying part starts supplying air to float the paper, and the paper advance mechanism 200 is activated to regulate the paper in a floating state to align the paper.

When there is an operation of pushing the drawer 300 into the housing, it indicates that there is a possibility that a user adds paper to the drawer 300. Whether the operation of pushing the drawer 300 into the shell exists or not is judged through the judging unit, after the judging unit judges that the operation of pushing the drawer 300 into the shell exists, the air supply part starts air supply to enable the paper to float, the paper advancing mechanism 200 is started, and therefore the floating paper is regulated, so that the topmost paper of the newly added paper is aligned, even if the next printing task starts without regulation, the first paper is also aligned, in addition, the printing speed is accelerated, the situation that the paper advancing mechanism 200 repeatedly regulates the paper after the paper is aligned to cause energy waste can be avoided, and the efficiency of regulating operation of the paper advancing mechanism 200 is improved.

Fig. 5 is a schematic configuration diagram of the sheet advancing mechanism 200 shown in fig. 3.

Referring to fig. 5, the sheet advancing mechanism 200 further includes: a drive motor 201; a gear transmission mechanism 202, wherein the driving motor 201 drives the gear transmission mechanism 202, the gear transmission mechanism 202 is connected to a guide rail 290, and the gear transmission mechanism 202 drives the paper advancing mechanism 200 to move along the conveying direction x (refer to fig. 3) or the reverse direction.

Fig. 6 is a partially enlarged view of the sheet advancing mechanism 200 shown in fig. 5.

Referring to fig. 6, the pushing plate 210 has a first end 211 and a second end opposite to each other, and the paper pushing mechanism 200 further includes: a propelling motor 220, a crankshaft 221 of the propelling motor 220 is connected to the first end 211, and the crankshaft 221 can drive the propelling plate 210 to move along the conveying direction x (refer to fig. 3) or the opposite direction under the driving force of the propelling motor 220.

The sheet advancing mechanism 200 further includes: a support shaft 230, wherein the thrust plate 210 is located on the support shaft 230, and the support shaft 230 is adapted to support and bear the thrust plate 210. The central axis of the support shaft 230 serves as an axis around which the push plate 210 rotates. On the one hand, the pushing plate 210 is movable relative to the supporting shaft 230 in the conveying direction x (refer to fig. 3) or in the opposite direction thereto, and on the other hand, the pushing plate 210 is rotatable around the central axis of the supporting shaft 230.

The sheet advancing mechanism 200 further includes: and two support plates 240 are arranged at two ends of the support shaft 230, and the support plates 240 are fixedly arranged on the inner wall of the shell.

In this embodiment, the supporting plate 240 is fixedly connected to the supporting shaft 230, so that the positions of the supporting plate 240 and the supporting shaft 230 are fixed. In other embodiments, the support plate 240 is only axially fixed with the support shaft 230, and the support shaft 230 is rotatable about a central axis relative to the support plate 240.

The number of the push plates 210 is one or more. Fig. 2 shows a case where the number of the push plates 210 is two. The two thrust plates 210 are arranged in parallel along the support shaft 230, and a space is provided between the two thrust plates 210.

The sheet advancing mechanism 200 further includes: a pressing shaft 250; a roller 260, wherein the roller 260 is fixedly arranged at the end of the pressing shaft 250, the roller 260 is positioned on the pushing plate 210, and the roller 260 is positioned between the first end 211 and the second end; the fixing frame 270, the fixing frame 270 is fixedly arranged on the inner wall of the housing, the frame wall of the fixing frame 270 is enclosed into a ring shape, a through hole 271 is formed in the frame wall, and the pressing shaft 250 penetrates through the through hole 271, so that the fixing frame 270 is sleeved on the pressing shaft 250; the spring 280 is sleeved on the pressing shaft 250, the spring 280 is located in the fixing frame 270, and the spring 280 is connected with the fixing frame 270 and the pressing shaft 250, so that the pressing shaft 250 can be reset after rotating.

The push plate 210 is made of an elastic material. The surface of the push plate 210 between the first end 211 and the roller 260 is parallel or nearly parallel to the surface of the paper. The roller 260 is located on the push plate 210, and the push plate 210 is pressed vertically downward by the roller 260. The pushing plate 210 between the second end and the roller 260 is rotated around the central axis of the supporting shaft 230 until the surface of the pushing plate 210 between the second end and the roller 260 is perpendicular to the surface of the paper.

As the propulsion motor 220 propels the propulsion plate 210 toward the rollers 260, the first end 211 gradually approaches the rollers 260, and correspondingly, the second end gradually moves away from the rollers 260, and more parts of the propulsion plate 210 surface turn perpendicular to the paper surface. When the crankshaft 221 of the propel motor 220 moves into contact with the rollers 260, all or nearly all of the propel plate 210 surface is perpendicular to the paper surface such that the propel plate 210 reaches the deployed position. Subsequently, the pusher motor 220 drives the pusher plate 210 to move in the conveying direction x (refer to fig. 3) or in the reverse direction, thereby regulating the sheet.

After the sheet regulation is completed, the pushing motor 220 pulls the pushing plate 210 away from the roller 260, the first end 211 gradually moves away from the roller 260, correspondingly, the second end gradually approaches the roller 260, and more parts of the surface of the pushing plate 210 turn to be parallel or close to being parallel to the surface of the sheet. When the second end portion is moved to touch the roller 260, all or nearly all of the surface of the pushing plate 210 is parallel to the surface of the paper, so that the pushing plate 210 reaches the avoiding position.

Referring to fig. 3, in the present embodiment, the paper feeding apparatus 100 further includes: a front plate (not shown in the figure) provided in a conveyance direction x of the sheet to be conveyed, the front plate being located on a front end side of the sheet, a surface of the front plate being perpendicular to a surface of the sheet; the sheet advancing mechanism 200 pushes the sheet in the floating state until the leading end of the sheet moves to the front plate.

The sheet advancing mechanism 200 applies a pushing force to the rear end of the sheet in a floating state, so that the sheet advances. Because the front plate is positioned at the front end side of the paper, and the surface of the front plate is perpendicular to the surface of the paper, when the front end of the paper moves to the front plate, the front end of each paper is positioned on the same plane, and correspondingly, the rear end of each paper is also positioned on the same plane, so that the paper alignment is ensured, and the regulation effect is improved.

In this embodiment, the paper feeding device 100 further includes: a rear plate 320, the rear plate 320 being located on the rear end side of the sheet, the rear plate 320 surface being perpendicular to the sheet surface. The rear plate 320 is movable in the conveyance direction x or the reverse direction thereof, and can preliminarily regulate the stacked sheets.

In another embodiment, the paper feeding device 100 may further include: a sheet information acquiring section (not shown in the figure) that acquires length information of a sheet in the conveyance direction x from information input by a user of the image forming apparatus body; a standard setting unit (not shown) that sets a standard position of the rear end of the sheet by the length information acquired by the sheet information acquiring unit; the sheet advancing mechanism 200 pushes the sheet in the floating state until the rear end of the sheet moves to the standard position.

When the rear end of the paper moves to the standard position, the paper pushing mechanism 200 stops pushing the paper, so that the rear end of each paper is located at the same position, and correspondingly, the front end of each paper is also located at the same position, thereby ensuring the alignment of the paper and improving the regulation effect.

In this embodiment, the sheet pushing mechanism 200 is moved to a predetermined length on the rear end side of the sheet based on the sheet length information acquired by the sheet information acquiring unit, and the pushing plate 210 is moved to regulate the floating sheet.

Thus, according to the sheet length information acquired by the sheet information acquiring unit, the sheet pushing mechanism 200 is first moved in the conveying direction x or the reverse direction thereof to move the sheet pushing mechanism 200 to the rear end side of the sheet by a predetermined length, and then the rear end of the sheet is pushed in the conveying direction x, so that the sheet can be protected by preventing the sheet pushing mechanism 200 from damaging the rear end of the sheet while ensuring the regulating effect. The predetermined length may be the sheet length plus N, for example the sheet length plus 1 cm.

Fig. 7 is an operational schematic diagram of the paper advance mechanism 200 shown in fig. 3.

Referring to fig. 7, the paper feeding device 100 may further have: a first sensor 410 provided on the paper advance mechanism 200 (refer to fig. 5) and adapted to determine whether or not there is a paper 101 below the paper advance mechanism 200; a second sensor 420, disposed on the paper feeding mechanism 200, adapted to determine whether the rear end of the paper 101 is located below the paper feeding mechanism 200.

The first sensor 410 and the second sensor 420 are disposed at intervals along the conveying direction x of the paper 101, and the second sensor 420 is located further forward than the first sensor 410, wherein the definition of the front-back direction is consistent with the definition of the front-back end direction of the paper 101.

The sector 500 enclosed by the dashed-dotted line in fig. 7 represents the sensing range of the first sensor 410. When the paper 101 below the paper pushing mechanism 200 is within the sensing range of the first sensor 410, the first sensor 410 determines that there is paper.

A dotted line 500 in fig. 7 indicates a maximum height of floating of the sheet 101, and when the sheet 101 floats up to the position of the dotted line 500, the sheet 101 comes into contact with the surface of the timing belt, and the conveying part 120 conveys the sheet 101 along a predetermined conveying path.

In this embodiment, before the paper advance mechanism 200 is started, the second sensor 420 determines that there is paper and the first sensor 410 determines that there is paper. At this time, first, the paper advance mechanism 200 moves backward until the first sensor 410 determines that there is no paper; then, the paper advance mechanism 200 moves forward, and during the forward movement, the second sensor 420 judges that there is no paper and the first sensor 410 judges that there is no paper; finally, when the second sensor 420 determines that there is paper and the first sensor 410 determines that there is no paper, the paper advance mechanism 200 stops advancing.

When the second sensor 420 determines that there is paper and the first sensor 410 determines that there is paper, it means that the paper pushing mechanism 200 is too far forward relative to the paper 101, and the paper pushing mechanism 200 moves backward until the first sensor 410 determines that there is no paper. Thus, by the first sensor 410 cooperating with the second sensor 420, the sheet advancing mechanism 200 can be moved to a proper position at the rear end of the sheet 101 before the regulating operation is performed. The sheet advancing mechanism 200 further moves forward to regulate the sheets 101 until the second sensor 420 judges that there is a sheet and the first sensor 410 judges that there is no sheet, which indicates that the rear end of each sheet 101 has been pushed to the position right below the second sensor 420, i.e., that the sheets 101 are aligned, and the regulating operation is completed, so that the sheet advancing mechanism 200 stops moving forward at this time. Thus, the paper advance mechanism 200 is stopped at appropriate times by the first sensor 410 and the second sensor 420, and the paper 101 can be prevented from being raised or the rear end of the paper 101 can be prevented from being damaged.

Fig. 8 is another operational schematic diagram of the paper advance mechanism 200 shown in fig. 3.

Referring to fig. 8, in another embodiment, before the paper advancing mechanism 200 is activated, the second sensor 420 judges that there is no paper and the first sensor 410 judges that there is no paper. At this time, the paper advance mechanism 200 moves forward until the second sensor 420 determines that there is paper and the first sensor 410 determines that there is no paper.

When the second sensor 420 determines that there is no paper and the first sensor 410 determines that there is no paper, it indicates that the paper pushing mechanism 200 is located at a certain distance from the rear end side of the paper 101, so that the paper pushing mechanism 200 can move forward to push the rear end of the paper 101 to align the paper 101. When the second sensor 420 determines that there is paper and the first sensor 410 determines that there is no paper, it indicates that the rear end of each paper 101 has been pushed to a position right below the second sensor 420, i.e. it indicates that the paper 101 is aligned and the regulating operation is completed, so that the paper advancing mechanism 200 stops advancing, on one hand, the alignment effect of the paper 101 is ensured, and on the other hand, the phenomenon that the paper 101 is arched or the rear end of the paper 101 is damaged is avoided.

The present invention also provides an image forming apparatus including the above-described paper feeding apparatus 100.

The paper feeding device 100 can be applied to an image forming apparatus, and can provide the above-described effects.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A sheet feeding device includes:

an air supply part which is positioned on the side surface of the paper to be conveyed and supplies air to the paper to enable the paper to float;

a suction unit which is positioned above the sheet and applies suction to the floating sheet;

a conveying section which is located above the sheet, and which conveys the sheet along a predetermined conveying path after the sheet is attracted to the conveying section by an attraction section, the conveying section further comprising:

and a sheet pushing mechanism located at a rear end side of the sheet to be conveyed, the sheet pushing mechanism being movable in the conveying direction and adapted to regulate the sheet in a floating state to align the sheet.

2. The paper feeding device according to claim 1, further comprising:

a housing;

the drawer is positioned in the shell and is suitable for placing paper to be conveyed;

it is characterized in that the preparation method is characterized in that,

the paper pushing mechanism is located in the shell and arranged on the top wall of the shell.

3. The sheet feeding apparatus as set forth in claim 1, wherein the sheet advancing mechanism includes: and a push plate having an open position and an evasive position for regulating the sheet.

4. The sheet feeding apparatus according to claim 1,

a front plate is arranged in the conveying direction of the paper to be conveyed, the front plate is positioned at the front end side of the paper, and the surface of the front plate is vertical to the surface of the paper;

the paper pushing mechanism pushes the paper in the floating state until the front end of the paper moves to the front plate.

5. The sheet feeding apparatus as set forth in claim 1, further comprising:

a paper information acquisition unit that acquires length information of a paper in a conveyance direction;

a standard setting unit that sets a standard position of a rear end of the sheet based on the length information acquired by the sheet information acquiring unit;

the paper pushing mechanism pushes the paper in the floating state until the rear end of the paper moves to the standard position.

6. The sheet feeding apparatus as set forth in claim 5, wherein the sheet advancing mechanism includes: a push plate having an open position and an evasive position for regulating the paper;

according to the paper length information acquired by the paper information acquiring part, the paper pushing mechanism moves to the rear end side of the paper by a preset length, and the pushing plate moves to regulate the floating paper.

7. The sheet supply device according to any one of claims 1 to 6, further comprising:

the first sensor is arranged on the paper feeding mechanism and is suitable for judging whether paper exists below the paper feeding mechanism or not;

the second sensor is arranged on the paper advancing mechanism and is suitable for judging whether the lower part of the paper advancing mechanism is the rear end of the paper or not;

when the second sensor judges that paper exists and the first sensor judges that paper exists, the paper pushing mechanism moves backwards until the first sensor judges that no paper exists; the paper pushing mechanism moves forwards, and in the process of moving forwards, the second sensor judges that no paper exists and the first sensor judges that no paper exists; and when the second sensor judges that paper exists and the first sensor judges that no paper exists, the paper advancing mechanism stops moving forwards.

8. The sheet feeding apparatus as set forth in claim 7, wherein when the second sensor determines that there is no sheet and the first sensor determines that there is no sheet, the sheet advancing mechanism moves forward until the second sensor determines that there is sheet and the first sensor determines that there is no sheet.

9. The sheet feeding apparatus as set forth in claim 2, comprising:

a judging unit adapted to judge whether there is an operation of pushing the drawer into the housing;

when the judging unit judges that the operation of pushing the drawer into the shell exists, the air supply part starts to supply air to enable the paper to float, the paper pushing mechanism is started, and the paper in the floating state is regulated to enable the paper to be aligned.

10. An image forming apparatus comprising the sheet feeding apparatus according to any one of claims 1 to 9.