CN110392661B

CN110392661B - Sheet separator using pressure

Info

Publication number: CN110392661B
Application number: CN201880013538.2A
Authority: CN
Inventors: 青木英司; 李镇受
Original assignee: Hewlett Packard Development Co LP
Current assignee: Hewlett Packard Development Co LP
Priority date: 2017-03-03
Filing date: 2018-01-05
Publication date: 2022-03-15
Anticipated expiration: 2038-01-05
Also published as: WO2018159936A1; EP3529184A4; US20200017324A1; EP3529184A1; CN110392661A; KR20180101054A

Abstract

A sheet separating apparatus includes: a separating member for contacting the feed roller and for separating the sheet-type media conveyed therebetween, the separating member being movable to a first position for contacting the feed roller at a first contact point to apply a first dynamic pressure and a second position for contacting the feed roller at a second contact point located on a downstream side of the first contact point in the take-out direction to apply a second dynamic pressure greater than the first dynamic pressure.

Description

Sheet separator using pressure

Background

Apparatuses such as printers, scanners, and ticket vending machines that use sheet-type media, for example, cut sheets (hereinafter, referred to as paper, or paper sheets), use a sheet separating device that feeds one sheet at a time from a loading tray on which a plurality of sheets are placed.

The sheet separating apparatus separates the paper into sheets fed one at a time by using a difference in frictional force between the feeding roller, the paper, and the separating member while the paper passes between the feeding roller and the separating member contacting the feeding roller.

The frictional force depends on a normal force between the feeding roller and the separating member and a friction coefficient between the feeding roller and the paper, a friction coefficient between one paper sheet and another paper sheet, and a friction coefficient between the paper sheet and the separating member. If the normal force is strong, the possibility of miss-feeding and the possibility of wear of the feed roller and/or the separating member may be reduced, while the possibility of multi-feeding of more than one sheet may be increased. On the other hand, if the normal force is weak, the possibility of multi-feeding may be reduced, while the possibility of skip-feeding and the possibility of abrasion of the feeding roller and/or the separating member may be increased.

Drawings

These and/or other aspects will become apparent and more readily appreciated from the following description of the examples, taken in conjunction with the accompanying drawings, in which:

fig. 1a is a schematic configuration diagram of a sheet separating apparatus according to an example;

fig. 1b is a schematic side view of the sheet separation device of fig. 1a according to an example;

FIG. 2 is a diagram of an active retard roll configuration according to an example;

FIG. 3 is a diagram of a semi-active retard roll configuration according to an example;

FIG. 4a is a diagram of a decoupling member in a first position, according to an example;

FIG. 4b is an illustration of a decoupling member in a second position, according to an example;

FIG. 4c is an operational diagram of a separation unit according to an example;

fig. 5a to 5e are diagrams of the operation of the sheet separating device in a case where no paper or only one sheet of paper is guided between the feeding roller and the separating member according to an example;

fig. 6a to 6c are diagrams of the operation of the sheet separating device in a case where at least two sheets of paper are guided between the feeding roller and the separating member according to an example;

fig. 7 is a schematic configuration diagram of a sheet separating apparatus according to an example;

fig. 8 is a perspective view of an implementation example of a structure that can move a separating member to a first position and a second position according to an example;

fig. 9 is a diagram of a sheet separating apparatus including a guide member according to an example;

fig. 10 is a perspective view of an example of an implementation of a structure that can move a separating member to a first position and a second position;

fig. 11 is a schematic configuration diagram of a sheet separating apparatus according to an example;

fig. 12 is a block diagram of a sheet processing apparatus including a sheet separating apparatus according to an example;

fig. 13 is a schematic configuration diagram of a scanner including a sheet separating device according to an example;

fig. 14 is a schematic configuration diagram of an image forming apparatus including a sheet separating device according to an example; and

fig. 15 is a schematic diagram of a multifunction device according to an example.

Detailed Description

Hereinafter, examples of a sheet separating device and a sheet processing apparatus using the same will be described with reference to the drawings, in which the same reference numerals denote the same elements throughout for clarity of description, and the size or thickness of each element may be exaggerated. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Fig. 1a is a schematic configuration diagram of a sheet separating apparatus 1 according to an example. Fig. 1b is a schematic side view of the sheet separation device 1 of fig. 1a according to an example.

Referring to fig. 1a and 1b, the sheet separating apparatus 1 includes: a loading tray 10 on which a sheet-type medium, for example, cut sheets (hereinafter referred to as paper, or paper sheets) P are placed; and a pickup roller (pickup member) 20 that picks up the sheet P placed on the loading tray 10. The pickup roller 20 is in contact with, for example, the paper P1 at the topmost of the paper sheets P placed on the loading tray 10. The pickup member is not limited to a roller type, and may be any of various types such as a belt type.

The pick roller 20 may be connected to the feed roller 31 by, for example, a belt. When the pickup roller 20 rotates, the paper P1 is picked up and guided or conveyed away from the loading tray 10. In some cases, the paper P1 and at least one sheet of paper P2 below the paper P1 may be guided or conveyed away together, which is called multi-feeding.

The sheet separating apparatus 1 further includes a separating unit for separating and conveying only one sheet of paper (e.g., paper P1) when multi-feeding occurs. The separation unit may have various structures such as an active retard roller structure, a semi-active retard roller structure, or a retard pad structure. The separating unit includes a feed roller 31 and a separating member 32 to be in contact with the feed roller 31 or being in contact with the feed roller 31. The elastic member 35a is for applying an elastic force (first elastic force) in a direction in which the separating member 32 is in contact with the feed roller 31.

Fig. 2 is a diagram of an active retard roll structure according to an example. Referring to fig. 2, the separating member 32 is a retard roller that contacts the feed roller 31. The feed roller 31 and the separation member 32 are rotationally engaged with each other. The feed roller 31 rotates in the first direction B1 for conveying the sheet P in the take-out direction a 1. The separation member 32 rotates in the second direction B2 for conveying the sheet P in the direction a2 opposite to the take-out direction a 1. The driving member (e.g., the driving gear 34) provides a driving force in the second direction B2 to the separating member 32. In addition to the gears, various power transmission members (such as a belt) may be used as the driving member.

The torque limiter 33 provides a threshold torque whereby the feed roller 31 begins to drive the separating member 32 to rotate. That is, the torque limiter 33 selectively allows the feed roller 31 to drive the separation member 32 to rotate according to the magnitude of the load torque applied to the separation member 32. When the load torque applied to the separating member 32 exceeds the threshold torque provided by the torque limiter 33, the driving force transmitted to the separating member 32 in the second direction B2 is blocked by the torque limiter 33, and the separating member 32 is allowed to be driven by the feed roller 31 to rotate in the third direction B3. When the load torque applied to the separating member 32 is less than the threshold torque provided by the torque limiter 33, the separating member 32 is rotated in the second direction B2 by the driving force of the driving gear 34.

The torque limiter 33 may have various known structures. For example, the torque limiter 33 may be implemented by a spring clutch structure. The separation member 32 is mounted at the support shaft 321 and engaged with the feed roller 31. When the support shaft 321 and the separation member 32 are integrally formed with each other, or when the separation member 32 is fixed to the support shaft 321, the support shaft 321 and the drive gear 34 are connected to each other by the torque limiter 33. For example, a clutch spring (not shown) may be inserted into the support shaft 321 or into a hub fixed to the support shaft 321, and a predetermined threshold torque may be provided by a clamping force of the clutch spring. The drive gear 34 provides a driving force in the second direction B2 to the clutch spring. When the load torque applied to the support shaft 321 is less than the threshold torque, the support shaft 321 rotates in the second direction B2. When the load torque applied to the support shaft 321 is greater than the threshold torque, the clutch spring is released (loosen), thereby preventing the driving force of the drive gear 34.

When the separating member 32 is rotatably installed at the support shaft 321, the support shaft 321 and the separating member 32 are connected to each other by the torque limiter 33. For example, a clutch spring (not shown) may be inserted into the support shaft 321 or into a hub fixed to the support shaft 321, and a predetermined threshold torque may be provided by a clamping force of the clutch spring. The ends of the clutch spring may be connected to the release member 32. The drive gear 34 is fixed to the support shaft 321 and rotates the support shaft 321 in the second direction B2. When the load torque applied to the decoupling member 32 is less than the threshold torque, the decoupling member 32 rotates in the second direction B2. When the load torque applied to the release member 32 is greater than the threshold torque, the clutch spring is released, thereby preventing the drive connection between the support shaft 321 and the release member 32.

The separation operation according to such a structure will now be briefly described.

When no paper P or only one paper P is guided between the feeding roller 31 and the separating member 32, the load torque applied to the separating member 32 is greater than the threshold torque of the torque limiter 33, and therefore, the torque limiter 33 blocks the driving force toward the separating member 32. Accordingly, the separating member 32 rotates in the third direction B3 to convey the sheet P in the take-out direction a1 in cooperation with the feed roller 31.

When at least two sheets of paper P (e.g., paper P1 and paper P2) are guided between the feed roller 31 and the separation member 32, the paper P1 and the paper P2 contact the feed roller 31 and the separation member 32, respectively. In this regard, the frictional force between the paper P1 and the paper P2 is smaller than the frictional force between the paper P2 and the separating member 32. Therefore, slippage may occur between the paper P1 and the paper P2, and the load torque applied to the separation member 32 is smaller than the threshold torque provided by the torque limiter 33. The separating member 32 rotates in the second direction B2, and the paper P2 is conveyed in the direction a2 opposite to the taking-out direction a1 by the separating member 32. Therefore, only the paper P1 passes between the feeding roller 31 and the separating member 32 and is conveyed in the take-out direction a 1.

Fig. 3 is a diagram of a semi-active retard roll configuration according to an example. Referring to fig. 3, the separating member 32 is a retard roller that contacts the feed roller 31. The difference between the structure of the semi-active retarding roller and the structure of the active retarding roller is as follows: the separating member 32 is not provided with the driving force in the second direction B2.

The feed roller 31 rotates in the first direction B1 for conveying the sheet P in the take-out direction a 1. The separation member 32 is rotatably installed at the support shaft 321. The separation member 32 is connected to the support shaft 321 through a torque limiter 33. The separating member 32 is driven by the feed roller 31 to rotate in the third direction B3.

The torque limiter 33 selectively allows the separating member 32 to rotate according to the magnitude of the load torque applied to the separating member 32. When the load torque applied to the separating member 32 exceeds the threshold torque provided by the torque limiter 33, the torque limiter 33 allows the separating member 32 to be rotated in the third direction B3 by the feed roller 31. When the load torque applied to the decoupling member 32 is less than the threshold torque provided by the torque limiter 33, the torque limiter 33 does not allow the decoupling member 32 to rotate.

When no paper P or only one paper P is guided between the feed roller 31 and the separating member 32, the load torque applied to the separating member 32 is greater than the threshold torque of the torque limiter 33, and therefore, the separating member 32 rotates in the third direction B3 to convey the paper P in the take-out direction a1 in cooperation with the feed roller 31.

When at least two sheets of paper P (e.g., paper P1 and paper P2) are guided between the feed roller 31 and the separation member 32, the paper P1 and the paper P2 contact the feed roller 31 and the separation member 32, respectively. In this regard, the frictional force between the paper P1 and the paper P2 is smaller than the frictional force between the paper P2 and the separating member 32. Therefore, slippage may occur between the paper P1 and the paper P2, and the load torque applied to the separation member 32 is smaller than the threshold torque provided by the torque limiter 33. The separating member 32 does not rotate, and the sheet P2 is jammed in the separating member 32 to stop without being conveyed in the take-out direction a 1. Therefore, only the paper P1 passes between the feeding roller 31 and the separating member 32 and is conveyed in the take-out direction a 1.

The sheet separating device 1 separates only one sheet of paper P1 by utilizing the difference in frictional force between the feed roller 31 and the paper P1, between the paper P1 and the paper P2, and between the separating member 32 and the paper P2. The frictional force depends on the normal force N between the feed roller 31 and the separating member 32 and the friction coefficient between the feed roller 31 and the paper P1, the friction coefficient between the paper P1 and the paper P2, and the friction coefficient between the paper P2 and the separating member 32. Since the coefficient of friction is determined by the material, the frictional force depends on the normal force N. If the normal force N is strong, the possibility of skip feeding and the possibility of abrasion of the feeding roller 31 and/or the separating member 32 may be reduced, and the possibility of multi-feeding may be increased. On the other hand, if the normal force N is weak, the possibility of multi-feeding may be reduced, and since the separating member 32 slips without being driven by the feed roller 31, the possibility of abrasion of the feed roller 31 and/or the separating member 32 may increase, and the possibility of skip-feeding may increase.

Therefore, when no paper P or only one paper P is guided between the feeding roller 31 and the separating member 32, the normal force N can be increased to reduce the possibility of missed feeding and the possibility of abrasion of the feeding roller 31 and/or the separating member 32. When at least two sheets of paper P are guided between the feeding roller 31 and the separating member 32, the normal force N can be reduced to reduce the possibility of multi-feeding.

The normal force N is influenced by the static pressure Ns caused by the elastic force Fs of the elastic member 35a that presses the separating member 32 against the feed roller 31 and by the dynamic pressure Nr1 caused by the torque Tr1 applied to the separating member 32 by the feed roller 31, and also by the dynamic pressure Nr2 caused by the torque Tr2 for driving the separating member 32 in the active retarding mechanism.

That is, in the semi-active retard roller mechanism and the retard pad mechanism, the following are satisfied:

n ═ Ns + Nr1 — (formula 1),

in the active retard roller mechanism, the following are satisfied:

n ═ Ns + Nr1+ Nr2 — (formula 2).

Therefore, the normal force N can be changed by adjusting the spring force Fs, the torque Tr1, and the torque Tr 2.

In order to adjust the elastic force Fs, means for detecting the number of sheets P guided between the feed roller 31 and the separation member 32 and active means for adjusting the free field length of the elastic member 35a (or adjusting the position of the support portion of the elastic member 35 a) are required. In addition, in order to adjust the torque Tr2, means for detecting the number of sheets P guided between the feed roller 31 and the separating member 32 and active means for adjusting the reduction gear ratio between the drive motor (not shown) and the separating member 32 are required.

In the present example, without a means of detecting the number of sheets P guided between the feed roller 31 and the separation member 32, a structure is adopted in which the normal force N is adjusted in accordance with the number of sheets P guided between the feed roller 31 and the separation member 32. In the present example, the normal force N is changed by adjusting the dynamic pressure Nr1 according to the number of sheets P guided between the feed roller 31 and the separation member 32.

Referring to fig. 1b, the separating member 32 is movable to a first position (shown in solid lines) and a second position (shown in dashed lines). The second position is located on the downstream side of the first position with respect to the rotational direction of the feed roller 31 or in the takeout direction of the sheet P. For example, the holder 36 is rotatable on the hinge 361. The separating member 32 is supported by the end of the bracket 36. The elastic member (first elastic member) 35a applies an elastic force so that the holder 36 rotates on the hinge 361 in a direction in which the separating member 32 comes into contact with the feed roller 31. The hinge 361 is movable from a position shown in solid lines in fig. 1b to a position shown in dashed lines. The second elastic member 35b provides an elastic force (second elastic force) in a direction for holding the separating member 32 at the first position (i.e., a direction for returning from the second position to the first position).

Fig. 4a is a view of the separating member 32 in a first position. Fig. 4b is a view of the disconnecting member 32 in a second position.

Referring to fig. 4a, the separating member 32 is placed in the first position. When the feed roller 31 rotates, the torque Tr1 acts on the separation member 32. Due to the torque Tr1, the force F of Tr1 × R acts on the first contact point C1 of the feed roller 31 and the separation member 32. In this regard, R is the radius of the separating member 32. The force F acts in a direction perpendicular to a line L11, which line L11 connects the center 32a or first contact point C1 of the separating member 32 to the center 31a of the feed roller 31. Since the separating member 32 is mounted so as to be rotatable on the hinge 361, the force F has a component in the direction of the line L11 and a component in the direction of the line L21, the line L21 connecting the first contact point C1 to the hinge 361. The first dynamic pressure Nr11 as a component of the force F in the direction of the line L11 corresponds to Nr1 of

equations

1 and 2. Nr11 is dependent on a first angle G1 between line L11 and line L21.

Referring to fig. 4b, the separating member 32 is placed in the second position. When the feed roller 31 rotates, the force F acts. The force F acts in a direction perpendicular to a line L12, which line L12 connects the center 32a or the second contact point C2 of the separating member 32 to the center 31a of the feed roller 31. Since the separating member 32 is mounted so as to be rotatable on the hinge 361, the force F has a component in the direction of the line L12 and a component in the direction of the line L22, the line L22 connecting the second contact point C2 to the hinge 361. The second dynamic pressure Nr12 as a component of the force F in the direction of the line L12 corresponds to Nr1 of

equations

1 and 2.

In this respect, the force F is the same. Nr1 depends on an angle between a first line connecting the center 31a of the feeding roller 31 to the center 32a of the separating member 32 or connecting the contact point of the feeding roller 31 and the separating member 32 to the center 31a of the feeding roller 31 and a second line connecting the contact point of the feeding roller 31 and the separating member 32 to the hinge 361. Nr1 increases as the angle between the first and second lines increases. A first angle G1 between line L11 and line L21 at the first position is less than a second angle G2 between line L12 and line L22 at the second position. Thus, Nr11 is less than Nr12 and the first normal force at the first position is less than the second normal force at the second position. Therefore, when one sheet of paper P is guided between the feeding roller 31 and the separating member 32, the separating member 32 is moved to the second position so that the separating unit can operate at a strong second normal force, and when at least two sheets of paper P are guided between the feeding roller 31 and the separating member 32, the separating member 32 is moved to the first position so that the separating unit can operate at a weak first normal force, thereby obtaining effects of preventing skip feeding, preventing multi-feeding, and preventing abrasion at the same time. As seen from the operation diagram of the separation unit shown in fig. 4c, the first position and the second position are located in the region where neither skip feeding nor multi feeding occurs. That is, the first position and the second position correspond to regions of the window a and the window b, respectively.

The second position or the second contact point C2 is located on the downstream side with respect to the rotational direction of the feed roller 31 as compared with the first position or the first contact point C1. In addition, the second position is a position where a second angle G2 between a first line connecting the center 31a of the feeding roller 31 to the center 32a of the separating member 32 and a second line connecting the contact point of the feeding roller 31 and the separating member 32 to the hinge 361 is larger than the first angle G1 at the first position.

The operation of the sheet separating apparatus 1 will now be described. Fig. 5a to 5e are diagrams of the operation of the sheet separating apparatus 1 in a case where no paper P or only one paper P is guided between the feeding roller 31 and the separating member 32. Fig. 6a to 6c are diagrams of the operation of the sheet separating device 1 in a case where at least two sheets of paper P are guided between the feeding roller 31 and the separating member 32.

First, the operation of the sheet separating apparatus 1 in the case where no paper P or only one paper P is guided between the feeding roller 31 and the separating member 32 will be described with reference to fig. 5a to 5 e.

Referring to fig. 5a, the disconnecting member 32 is placed in a first position when in a stopped or standby state. The separating member 32 is in contact with the feeding roller 31 due to the elastic force of the first elastic member 35 a. In addition, the separation member 32 is held at the first position by the elastic force of the second elastic member 35 b.

When the feed roller 31 rotates in the first direction B1, a torque in the third direction B3 acts on the separating member 32 due to a frictional force between the feed roller 31 and the separating member 32. The decoupling member 32 does not rotate in the third direction B3 due to the resistance provided by the torque limiter 33. Instead, the hinge 361 is pushed in the opposite direction of the elastic force of the second elastic member 35B (i.e., the direction D1), and the separating member 32 moves to the second position while rotating in the second direction B2. The separating member 32 is kept in contact with the feed roller 31 by the elastic force of the first elastic member 35a while moving from the first position to the second position. As shown in fig. 5B, when the separating member 32 reaches the second position, the separating member 32 is driven by the feed roller 31 to rotate in the third direction B3.

The second normal force at the second location is greater than the first normal force at the first location. No slip occurs between the feed roller 31 and the separating member 32, and the separating member 32 is driven to rotate by the feed roller 31. Therefore, the wear of the feed roller 31 and/or the separation member 32 can be reduced.

As shown in fig. 5c, even when a sheet of paper P picked up from the loading tray 10 by the pickup roller 20 is guided between the feeding roller 31 and the separating member 32, the separating member 32 can be maintained at the second position. Since the second normal force is greater than the first normal force, the paper P can be stably conveyed without skip feeding.

As shown in fig. 5d, when the feeding roller 31 rotates, the separating member 32 remains at the second position although the paper P is completely conveyed. As shown in fig. 5e, when the feed roller 31 stops, the hinge 361 moves in the direction D2. As shown in fig. 5e, when the feed roller 31 stops rotating, the separation member 32 is returned to the first position by the elastic force of the second elastic member 35 b.

Next, the operation of the sheet separating apparatus 1 in the case where at least two sheets of paper P are guided between the feeding roller 31 and the separating member 32 will be described with reference to fig. 6a to 6 c.

In the state shown in fig. 5b, the paper P is picked up from the loading tray 10 by the pickup roller 20, and the paper P is conveyed between the feeding roller 31 and the separating member 32. In this regard, as shown in fig. 6a, at least two sheets of paper P (e.g., paper P1 and paper P2) may be guided between the feeding roller 31 and the separating member 32. In this regard, since the separating member 32 is placed at the second position and is pressed against the feeding roller 31 by the strong second normal force, the paper P1 and the paper P2 can be certainly conveyed without being fed missing until the paper P1 and the paper P2 are both guided between the feeding roller 31 and the separating member 32.

The frictional force between the paper P1 and the paper P2 is smaller than the frictional force between the paper P1 and the feed roller 31 and smaller than the frictional force between the paper P2 and the separation member 32, and therefore, as shown in fig. 6b, for example, when two sheets of paper P1 and P2 are surely guided between the feed roller 31 and the separation member 32, a slip occurs between the paper P1 and the paper P2. Then, since the torque of the feed roller 31 is not transmitted to the separating member 32, the load torque applied to the separating member 32 becomes smaller than the threshold torque of the torque limiter 33. Then, the separation member 32 is stopped. When the torque of the feeding roller 31 is not transmitted to the separating member 32, the force to keep the separating member 32 at the second position disappears, and the hinge 361 is moved in the direction D2 by the elastic force of the second elastic member 35 b. As shown in fig. 6c, the disconnecting member 32 returns to the first position.

In this regard, a quick return operation occurs in which the separating member 32 quickly returns the paper P2 toward the loading tray 10. In addition, when the separating member 32 returns to the first position, the sliding between the paper P1 and the paper P2 continues to occur, and therefore, the separating member 32 is held at the first position. In the active retarding mechanism, the separating member 32 rotates in the second direction B2, while in the semi-active retarding mechanism, the separating member 32 stops. A first normal force weaker than the second normal force acts between the feed roller 31 and the separating member 32. Therefore, only the paper P1 can be separated and conveyed stably without overfeeding.

When the paper P1 is completely conveyed and the paper P2 is guided again between the feed roller 31 and the separation member 32, the paper P2 is conveyed in accordance with the operation shown in fig. 5a to 5 e.

As described above, when no paper P or only one paper P is guided between the feeding roller 31 and the separating member 32, the separating member 32 moves to the second position, and a strong second normal force acts between the feeding roller 31 and the separating member 32. Therefore, the separating member 32 can be definitely driven by the feeding roller 31, and therefore, the feeding roller 31 and/or the separating member 32 can be prevented from being worn, and a sheet of paper P can be stably conveyed without missing feeding.

When at least two sheets of paper P are guided between the feeding roller 31 and the separating member 32, since the separating member 32 is immediately returned from the second position to the first position, the paper P2 in contact with the separating member 32 can be immediately returned in the direction opposite to the conveying direction of the paper P1. This is very effective for preventing multi-feeding in the semi-active retard roller mechanism in which the separating member 32 does not rotate in the reverse direction (i.e., does not rotate in the second direction B2). In addition, at the first position, since the first normal force weaker than the second normal force acts between the feeding roller 31 and the separating member 32, only the paper P1 can be stably separated and conveyed without being overfed.

To test the effect of the sheet separating apparatus 1 according to the present example, 109 test sheets were prepared. The 109 test sheets included 10 reams of unused sheets (each ream including 10 sheets) and 9 sheets of used sheets located between the reams. The friction coefficients of the unused paper and the used paper are different from each other, and thus multi-feeding may occur. For example, the unused paper has a coefficient of friction of 0.7 and the used paper has a coefficient of friction of 0.3. The used paper may be, for example, paper whose surface is printed with a black or gray image. The results obtained by testing the multi-feed using this test paper are as follows.

As shown in table 1 below, in the case of the sheet separating device (the separating member 32 is located at a fixed position) in the related art, a bad result of a large number of unused sheets being multi-fed two sheets on a used sheet was obtained.

[ Table 1]

As shown in table 2 below, in the case of the sheet separating apparatus 1 according to the present example, very good results without multi-feeding in three tests were obtained.

[ Table 2]

Fig. 7 is a schematic configuration diagram of the sheet separating apparatus 1 according to the example. The sheet separating apparatus 1 shown in fig. 7 differs from the sheet separating apparatus 1 shown in fig. 1a in that: the hinge 361 is connected to the link 37, and the link 37 is connected to the rotation shaft 38. According to the above configuration, when the link 37 rotates in the direction E with respect to the rotation shaft 38, the hinge 361 moves. Thus, the decoupling member 32 may be allowed to move to a first position (represented by solid lines) and a second position (represented by dashed lines). The operation of the sheet separating device 1 illustrated in fig. 7 is the same as that described above with reference to fig. 5a to 5e and fig. 6a to 6 c.

Fig. 8 is a perspective view of an implementation example of a structure that can move the separating member 32 to the first position and the second position. The embodiment example shown in fig. 8 is applicable to the example of the sheet separating apparatus 1 shown in fig. 7.

Referring to fig. 8, the bracket 36 may have a "U" shape supporting both ends of the separation member 32. Therefore, when the separating member 32 is moved to the first position and the second position, the deviation of the separating member 32 in the width direction of the paper P can be minimized to allow stable position movement.

In the active retard roller mechanism, a drive member (e.g., the drive gear 34 shown in fig. 1 a) may be connected to the support shaft 321.

The link 37 may have a "U" shape supporting the bracket 36 to be rotatable on the hinge 361. The link 37 is rotatably supported on the rotation shaft 38. When the link 37 rotates on the rotation shaft 38 in the direction E, the hinge 361 may move, and when the bracket 36 rotates on the hinge 361, the separating member 32 may move to the first position and the second position.

The first elastic member 35a is supported by the link 37 and the bracket 36. For example, the first elastic member 35a may be a compression coil spring, one end of which is supported by the link 37 and the other end of which pushes the bracket 36. When the separation member 32 moves to the first and second positions, the first elastic member 35a also moves together, and therefore, the variation of the elastic force of the first elastic member 35a at the first and second positions can be minimized. Accordingly, since only the dynamic pressure changes when the separating member 32 moves to the first and second positions, the normal force at the first and second positions can be stably set such that the operation region of the separating unit can be within the region of the operation diagram of the separating unit shown in fig. 4c, in which neither the skip feeding nor the multi-feeding occurs.

In the present example, the second elastic member 35b is connected to the link 37, and applies an elastic force to the link 37 in a direction in which the separation member 32 moves to the first position. However, the present disclosure is not limited thereto, and as shown in fig. 7, the second elastic member 35b may be connected to the bracket 36.

Fig. 9 is a diagram of the sheet separating apparatus 1 including the guide member 40 according to an example. Fig. 9 shows the guide member 40 in detail, and the rest of the sheet separating apparatus 1 is omitted. Referring to fig. 9, the guide member 40 is located on the upstream side of the separating member 32 with respect to the conveying direction of the paper P. The guide member 40 guides the bottom surface of the paper P so that the paper P picked up by the pickup roller 20 can be stably guided between the separation member 32 and the feed roller 31.

In this example, the guide member 40 moves together with the separating member 32. That is, even when the separating member 32 moves to the first position and the second position, the relative position between the separating member 32 and the guide member 40 does not change. Accordingly, the picked-up paper P may be guided by the guide member 40 and stably guided between the feeding roller 31 and the separating member 32.

For this purpose, the guide member 40 is mounted at the bracket 36. In an example, the guide member 40 may be combined with the bracket 36. For example, the guide member 40 may be a membrane member and may be attached to the bracket 36. In another example, the guide member 40 may be integrally formed with the bracket 36.

Fig. 10 is a perspective view of an implementation example of a structure that can move the separating member 32 to the first position and the second position. The embodiment example shown in fig. 10 is applicable to the example of the sheet separating apparatus 1 shown in fig. 1 b.

Referring to fig. 10, the bracket 36 may have a "U" shape for supporting both ends of the separation member 32. Therefore, when the separating member 32 is moved to the first position and the second position, the deviation of the separating member 32 in the width direction of the paper P can be minimized to allow stable position movement.

The hinge 361 may be supported by the elastic frame 60. For example, the hinge 361 may be installed at the bracket 50, and the bracket 50 may be fixed to the elastic frame 60. The bracket 50 may have a "U" shape for supporting the stand 36 to be rotatable on the hinge 361. The elastic frame 60 may extend in the width direction of the paper P (i.e., the length direction of the feeding roller 31 and the separating member 32). When no paper P or only one paper P is guided between the feeding roller 31 and the separating member 32, a pushing force in a direction from the first position to the second position acts on the separating member 32 when the feeding roller 31 rotates. In this regard, the elastic frame 60 allows the hinge 361 to move while being elastically deformed (as shown by a dotted line in fig. 10). Thus, the disconnecting member 32 is movable from the first position to the second position. When at least two sheets of paper P are guided between the separation member 32 and the feed roller 31, or when the feed roller 31 is stopped, the elastic frame 60 elastically returns to the position indicated by the solid line. Thus, the disconnecting member 32 may return from the second position to the first position. As described above, the elastic frame 60 supports the holder 36 to be rotatable on the hinge 361, and at the same time, the elastic frame 60 serves as the second elastic member 35b that provides an elastic force in a direction to return the separating member 32 from the second position to the first position.

Although not shown, the hinge 361 may be directly mounted to the elastic frame 60.

Although not shown, the first elastic member 35a may be supported by the bracket 50 and the bracket 36. Accordingly, when the separating member 32 moves to the first and second positions, since only the dynamic pressure changes, the normal forces at the first and second positions can be stably set and controlled.

Fig. 11 is a schematic configuration diagram of the sheet separating apparatus 1 according to the example. In the previous example, a rotating retard roller is used as the separation member 32. However, in the present example, a retardation pad is used as the separation member 32. The retardation pad is a friction pad and satisfies the condition: the friction coefficient between the retard pad and the paper P is smaller than the friction coefficient between the feed roller 31 and the paper P and is larger than the friction coefficient between the paper P.

For example, the blocker pad is pivotally supported by one end of the bracket 36. The other end of the bracket 36 is pivotably supported by a hinge 361. To allow the blocker pad to move to a first position (shown in solid lines) and a second position (shown in phantom lines), the hinge 361 may be resiliently movable, such as by the structures shown in fig. 1b, 10, or 7 and 8.

The operation in the example in which a retardation pad is used as the separating member 32 is the same as that described above with reference to fig. 5a to 5e and 6a to 6 c.

The sheet separating apparatus 1 can be used in various apparatuses. Fig. 12 is a block diagram of a sheet processing apparatus including the sheet separating device 1 according to an example. Referring to fig. 12, the sheet processing apparatus includes: a sheet feeder 1a including a sheet separating device 1; and a sheet processor 2 that receives the paper P from the paper feeder 1a and processes the paper P. The processed paper P may be discharged into the output tray 3.

Fig. 13 is a schematic configuration diagram of a scanner 600 including the sheet separating device 1 according to an example. Referring to fig. 13, the scanner 600 includes a media processor that reads an image while conveying a document D supplied by a paper feeder including the sheet separating device 1. The media processor may include a document feeding unit 600a and a reading unit 600b that reads an image from a document. The sheet separating device 1 has been described with reference to fig. 1a to 11. Since the scanner 600 is a device that reads an image recorded on the document D, the sheet separating apparatus 1 conveys the document D.

The reading unit 600b includes a reading member 650 for reading an image from the document D. The reading member 650 emits light toward the document D, receives light reflected from the document D, and reads an image of the document D. A contact type image sensor (CIS), a Charge Coupled Device (CCD), or the like may be used as the reading member 650.

The scanner 600 uses a flatbed method in which the document D is located at a fixed position and a reading member (such as CIS or CCD) reads an image while moving, a document feeding method in which the reading member is located at a fixed position and the document D is conveyed, or a combination thereof. The scanner 600 according to the present example is a scanner using a combination of the flatbed method and the document feeding method.

The reading unit 600b includes a platen glass 660 on which the document D is placed to read an image from the document D by using a flat plate method. In addition, the reading unit 600b includes a reading window 670 for reading an image from the document D by using the document feeding method. The reading window 670 may be, for example, a transparent member. In an example, the height of the upper surface of the reading window 670 may be the same as the height of the upper surface of the platen glass 660.

When the document feeding method is used, the reading member 650 is located below the reading window 670. When the flat plate method is used, the reading member 650 may be moved in the sub-scanning direction S (i.e., the length direction of the document D) below the platen glass 660 by a conveying device (not shown). In addition, when the flat plate method is used, the platen glass 660 may be exposed to the outside to place the document D on the platen glass 660. For this, the document feeding unit 600a may rotate relative to the reading unit 600b to expose the platen glass 660.

The document feeding unit 600a conveys the document D so that the reading member 650 can read the image recorded on the document D and discharge the read document D. To this end, the document feeding unit 600a includes a document feeding path 610, and the reading member 650 reads an image from the document D conveyed along the document feeding path 610. The document feeding path 610 may include, for example, a supply path 611, a read path 612, and a discharge path 613. The reading member 650 is disposed in the reading path 612, and an image recorded on the document D is read by the reading member 650 while passing through the reading path 612. The supply path 611 is a path for supplying the document D to the read path 612, and the document D loaded on the loading tray 10 is supplied to the read path 612 via the supply path 611. The discharge path 613 is a path for discharging the document D having passed through the read path 612. Accordingly, the document D loaded on the loading tray 10 is conveyed along the supply path 611, the read path 612, and the discharge path 613, and is discharged to the discharge tray 630.

Conveying

rollers

621 and 622 for conveying the document D taken out of the loading tray 10 by the sheet separating apparatus 1 may be provided in the supply path 611. Each of the conveying

rollers

621 and 622 may have a structure in which a driving roller and a driven roller rotate while engaging with each other.

Conveying

rollers

623 and 626 for conveying the document D may be provided in the reading path 612. For example, conveying

rollers

623 and 626 for conveying the document D may be provided on both sides of the reading member 650. Each of the conveying

rollers

623 and 626 may have a structure in which a driving roller and a driven roller rotate while engaging with each other. A reading guide member 624 facing the reading member 650 is disposed in the reading path 612. The reading guide member 624 is pressed against the reading window 670 by its own weight or the elastic member 625, and the document D is conveyed to reach between the reading window 670 and the reading guide member 624. Although not shown, a reading roller that elastically presses against the reading window 670 and rotates to convey the document D supplied therebetween may be used instead of the reading guide member 624.

A discharge roller 627 which discharges the document D which has been read is provided in the discharge path 613. The ejecting roller 627 may have a structure in which the driving roller and the driven roller rotate while engaging with each other.

With the above configuration, the document D supplied by the sheet separating apparatus 1 is conveyed along the supply path 611, the reading path 612, and the discharge path 613, and the reading member 650 can read an image from the document D.

Fig. 14 is a schematic configuration diagram of an image forming apparatus 700 including the sheet separating device 1 according to an example. Referring to fig. 14, the image forming apparatus 700 includes a printing unit (media processor) 700a that prints an image on paper P supplied by a paper feeder. As shown by a solid line in fig. 14, the paper feeder may be in the form of a paper feeder 1b including the sheet separating device 1, and may be located below the printing unit 700 a. In addition, as shown by a dotted line in fig. 14, the sheet separating apparatus 1 may be applied to a multi function tray (MPT)1c located at a side of the printing unit 700 a.

The printing unit 700a according to the present example can print an image on the paper P by using various methods such as an electrophotographic method, an inkjet method, a thermal transfer method, or a thermal sublimation method. The image forming apparatus 700 according to the present example prints a color image on paper P by using an electrophotographic method. Referring to fig. 14, the printing unit 700a may include a plurality of developing devices 710, exposing devices 720, transferring devices, and fixing devices 740.

For color printing, the plurality of developing devices 710 may include, for example, four developing devices 710 for developing cyan C images, magenta M images, yellow Y images, and black K images. The four developing devices 710 may contain cyan C toner, magenta M toner, yellow Y toner, and black K toner, respectively. In addition to the above-described colors, the printing unit 700a may further include a developing device 710 for accommodating toners of various colors (such as light magenta and white), and develop such color images.

The developing device 710 includes a photosensitive drum 7 a. The photosensitive drum 7a is an example of a photosensitive body having an electrostatic latent image formed on the surface thereof, and may include a conductive metal pipe and a photosensitive layer formed on the outer periphery thereof. The charging roller 7c is an example of a charger that charges the photosensitive drum 7a to have a uniform surface potential. The cleaning blade 7d is an example of a cleaning device for removing toner and foreign matter remaining on the surface of the photosensitive drum 7a after a transfer process (described below).

The developing device 710 supplies the toner contained therein to the electrostatic latent image formed on the photosensitive drum 7a, thereby developing the electrostatic latent image into a visible toner image. Examples of the developing method include a one-component developing method using a toner and a two-component developing method using a toner and a carrier. The developing device 710 according to the present example uses a one-component developing method. The developing roller 7b is used to supply toner to the photosensitive drum 7 a. A developing bias voltage for supplying toner to the photosensitive drum 7a may be applied to the developing roller 7 b.

The one-component developing method may be classified into a contact developing method in which the developing roller 7b and the photosensitive drum 7a rotate in contact with each other and a non-contact developing method in which the developing roller 7b and the photosensitive drum 7a rotate spaced apart from each other by about several tens to several hundreds of micrometers. The supply roller 7e supplies the toner in the developing device 710 to the surface of the developing roller 7 b. A supply bias voltage for supplying the toner in the developing device 710 to the surface of the developing roller 7b may be applied to the supply roller 7 e.

The exposure device 720 forms an electrostatic latent image on the photosensitive drum 7a by irradiating light modulated according to image information onto the photosensitive drum 7 a. A Laser Scanning Unit (LSU) using a laser diode as a light source, a Light Emitting Diode (LED) using an LED as a light source, and the like may be used as the exposure device 720.

The transfer device may include an intermediate transfer belt 731, a first transfer roller 732, and a second transfer roller 733. The toner images developed on the photosensitive drums 7a of the four developing devices 710 are temporarily transferred to the intermediate transfer belt 731. The intermediate transfer belt 731 circulates while being supported by

support rollers

734, 735, and 736. Four first transfer rollers 732 are provided at positions facing the photosensitive drums 7a of the four developing devices 710, and the intermediate transfer belt 731 is between the four first transfer rollers 732 and the photosensitive drums 7 a. A primary transfer bias voltage for primary transfer of the toner image developed on the photosensitive drum 7a to the intermediate transfer belt 731 is applied to the four primary transfer rollers 732. The second transfer roller 733 faces the intermediate transfer belt 731. A second transfer bias voltage for transferring the toner image primarily transferred to the intermediate transfer belt 731 onto the paper P is applied to the second transfer roller 733.

When receiving a print command from a host computer (not shown), a controller (not shown) charges the surface of the photosensitive drum 7a to a uniform potential via the charging roller 7 c. The exposure device 720 forms an electrostatic latent image on the photosensitive drum 7a by scanning four light beams modulated according to image information of each color onto the photosensitive drums 7a of the four developing devices 710. The developing rollers 7b develop the electrostatic latent images into visible toner images by supplying C, M, Y, K toners to the corresponding photosensitive drums 7a, respectively. The developed toner image is primarily transferred to the intermediate transfer belt 731. The paper P is conveyed from the

paper feeder

1b or 1c to a transfer nip formed by the secondary transfer roller 733 and the intermediate transfer belt 731. The toner image primarily transferred onto the intermediate transfer belt 731 is secondarily transferred onto the paper P by a secondary transfer bias voltage applied to the secondary transfer roller 733. When the paper P passes through the fixing device 740, the toner image is fixed onto the paper P by heat and pressure. The paper P on which the fixing has been performed is discharged to the outside by the discharge roller 750.

The scanner 600 and the imaging apparatus 700 may each be used alone, or may be combined with each other to function as a multi-function apparatus. Fig. 15 is a schematic diagram of a multifunction device according to an example.

Referring to fig. 15, a scanner 600 is provided on a printing unit 700 a. The scanner 600 has the same structure as the scanner 600 shown in fig. 13 and the printing unit 700a has the same structure as the printing unit 700a shown in fig. 14. The sheet separating apparatus 1 for supplying the paper P to the printing unit 700a may be implemented in various forms. For example, the examples of the sheet separating device 1 illustrated in fig. 1a to 11 may be applied to: MPT at the side of the printing unit 700a (as shown in fig. 14), main paper feed cassette 810 installed below the printing unit 700a (as shown in fig. 15), secondary paper feed cassette 820 installed below the main paper feed cassette 810, high-capacity feeder 830 installed below the main paper feed cassette 810 or below the secondary paper feed cassette 820, high-capacity feeder 840 installed at the side of the printing unit 700a, and the like.

It is to be understood that the examples described herein are to be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example should generally be considered as applicable to other similar features or aspects in other examples.

Although one or more examples have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the inventive concept as defined by the following claims.

Claims

1. A sheet separating apparatus comprising:

a feed roller for conveying the sheet-type medium in a take-out direction;

a separating member for contacting the feed roller to separate the plurality of sheet-type media conveyed therebetween;

a holder for supporting the separating member, the holder being rotatable, and the separating member being pivotably supported by the holder;

a hinge for rotatably supporting the stand; and

a first elastic member for providing a first elastic force in a direction allowing the separation member to come into contact with the feed roller,

wherein the disconnecting member is movable to a first position and a second position,

at the first position, the separating member contacts the feed roller at a first contact point on the feed roller to apply a first dynamic pressure, and

at the second position, the separating member is in contact with the feed roller at a second contact point on the feed roller to apply a second dynamic pressure that is greater than the first dynamic pressure, wherein the second contact point is located on a downstream side of the first contact point in the take-out direction;

the sheet separating apparatus further includes an elastic frame extending in a length direction of the separating member, the hinge being mounted to and supported by the elastic frame, the elastic frame allowing the hinge to move by elastic deformation to move the separating member from the first position to the second position, and the separating member returning from the second position to the first position when the elastic deformation of the elastic frame is removed.

2. The sheet separating apparatus of claim 1 further comprising a bracket fixed to the resilient frame and to which the hinge is mounted.

3. The sheet separation device of claim 1, wherein the hinge is mounted directly to the resilient frame.

4. The sheet separating device according to claim 1,

a second angle formed between a line passing through the second contact point and the center of the feed roller and a line passing through the second contact point and the hinge when the separation member is in the second position is larger than a first angle formed between a line passing through the first contact point and the center of the feed roller and a line passing through the first contact point and the hinge when the separation member is in the first position.

5. The sheet separating apparatus according to claim 1, further comprising a guide member for guiding the bottom surfaces of the plurality of sheet-type media conveyed between the feed roller and the separating member and moving together with the separating member.

6. The sheet separating device according to claim 5, wherein the guide member is connected to the bracket.

7. The sheet separating apparatus according to claim 1, wherein the first elastic member applies a first elastic force to the holder to rotate the holder in a direction allowing the separating member to contact the feed roller.

8. The sheet separating apparatus according to claim 2, wherein the bracket has a "U" shape for supporting the bracket.

9. The sheet separating apparatus according to claim 8, wherein the first elastic member is supported by the bracket and the stand.

10. The sheet separating apparatus according to claim 1, wherein the bracket has a "U" shape for supporting both ends of the separating member.

11. The sheet separating device according to claim 1, wherein the elastic frame has a plate shape.

12. The sheet separating device according to claim 1, further comprising a torque limiter,

wherein the separation member comprises a retard roller, and

the torque limiter selectively starts rotation of the retard roller caused by rotation of the feed roller according to a magnitude of a load torque applied to the retard roller.

13. The sheet separating apparatus according to claim 12 further comprising a drive member for transmitting torque in a direction opposite to the take-out direction.

14. The sheet separation device of claim 1, wherein the separation member comprises a blocker pad.