JP7265722B2 - Sheet feeding device and image forming device - Google Patents

Description

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

Conventionally, an abutting member is provided with an abutting portion with which the leading end of the sheet in the feeding direction abuts, the abutting member being rotatable between an abutting position where the abutting portion abuts against the sheet and a retracted position where it does not abut against the sheet, and the abutting member. An engaging portion is provided for restricting rotation of the abutment member from the abutting position to the retracted position by engaging the engaged portion, and the engaging portion engages the engaged portion. A sheet feeding device is known that has a locking member rotatable at a stop position and a locking release position for releasing the locking. In this sheet feeding apparatus, the locking member is applied with locking biasing force in the locking direction from the locking release position to the locking position by its own weight or biasing means. In this sheet feeding device, the abutting member rotates from the retracted position to the abutting position while the sliding portion of the locking member slides against the slid portion of the abutting member. When the abutting member rotates to the abutting position, the sliding portion is disengaged from the slidable portion, and the locking member rotates to the locking position by the locking biasing force.

For example, Japanese Patent Application Laid-Open No. 2002-100003 discloses a contact member having the above-described configuration for the purpose of preventing the leading edge of a sheet from entering the downstream side of the target set position in the feeding direction when the sheet is set. is positioned at the abutting position, and the abutting portion of the abutting member prevents the leading edge of the sheet from entering.

However, in the conventional sheet feeding device, the abutting member cannot return to the abutting position at the end of feeding, and the leading edge of the newly set sheet moves downstream of the target set position in the feeding direction. Sometimes I couldn't stop myself from doing it.

In order to solve the above-mentioned problems, the present invention is provided with an abutting portion against which the leading edge of the sheet in the feeding direction abuts, the abutting portion being rotatable between an abutting position where the abutting portion abuts against the sheet and a retracted position where it does not abut against the sheet. and an engaging portion that restricts rotation of the abutting member from the abutting position to the retracted position by engaging the engaged portion of the abutting member, the engaging portion has a locking member rotatable between a locking position for locking the locked portion and a locking release position for releasing the locking, and the locking member is rotatable by its own weight or biasing means. A locking biasing force is applied in the locking direction from the unlocked position to the locking position, and the sliding portion of the locking member and the slid portion of the abutment member slide. When the abutment member rotates from the retracted position to the abutment position, and the abutment member rotates to the abutment position, the sliding portion is disengaged from the slidable portion, and the locking member is engaged. In the sheet feeding device that rotates to the locking position by a stop biasing force, the abutting member has the locked portion and the slidable portion that are different from each other in the direction of the central axis of rotation of the abutting member. It is characterized by being equipped with a position.

According to the present invention, it is possible to suppress the occurrence of a situation in which the abutment member does not return to the abutment position at the end of feeding.

FIG. 2 is a perspective view showing the main parts of the sheet feeding device according to the embodiment; 1 is a schematic configuration diagram of a copying machine according to an embodiment; FIG. FIG. 2 is a block diagram showing main parts of the copier; Sectional drawing of the cross section shown with the code|symbol A in FIG. Sectional drawing of the cross section shown with the code|symbol B in FIG. Sectional drawing of the cross section shown with the code|symbol C in FIG. 4(a) and 4(b) are perspective views of states in which the paper stopper is located at the abutment position in the embodiment, viewed from different directions. FIG. (a) and (b) are perspective views of a state in which the paper stopper is positioned at the retracted position, viewed from different directions. 4(a) and 4(b) are perspective views of a state in which the sliding surface of the paper stopper and the sliding projection of the paper stopper rotation regulating member are in contact with each other, viewed from different directions. FIG. 10 is an explanatory view showing the force received by the paper stopper when the paper stopper returns to the abutting position at the end of paper feeding in the paper stopper and the paper stopper rotation regulating member in the conventional configuration; FIG. 5 is an explanatory diagram showing components of force received by the sheet stopper; FIG. 5 is an explanatory diagram for explaining the shaft frictional force received from the peripheral surface of the stopper shaft when the paper stopper rotates; FIG. 5 is an explanatory diagram for explaining conditions for the paper stopper to return to the abutting position; (a) to (d) are explanatory diagrams for explaining the load acting on the contact point while the paper stopper of the conventional configuration rotates from the retracted position to the abutment position. FIG. 4 is a side view of the paper stopper according to the embodiment, viewed from a direction orthogonal to the central axis of rotation of the paper stopper; 4A to 4D are explanatory diagrams for explaining the load acting on the contact point while the paper stopper in the embodiment rotates from the retracted position to the contact position; FIG. FIG. 4 is an explanatory diagram showing an example of layout constraints in the embodiment;

An embodiment of an electrophotographic image forming apparatus to which the present invention is applied will be described below.
FIG. 2 is a schematic configuration diagram of a copier 100, which is an image forming apparatus according to the embodiment.

A copier 100 shown in FIG. 2 includes an ADF 200 as an automatic document feeder, a scanner section 300 as an image reading device, and a printer section 101 for forming an image on a sheet S of paper. The scanner unit 300 reads an image of a sheet-shaped document conveyed by the ADF 200 and an image of a document placed on the contact glass of the scanner unit 300 . The printer unit 101 forms an image on a sheet S based on image information input from an external device such as a personal computer or image information of a document read by the scanner unit 300 .

In the printer section 101, an image forming section 110 as a printer engine, a fixing device 120, and an optical writing device 112 are arranged. The printer unit 101 also includes an in-apparatus paper feed unit 400 having an in-apparatus paper feed tray 103 for stacking and holding sheets S. As shown in FIG.
Further, on the right side of the printer section 101 in FIG. 2, there is provided a manual paper feeding device 105 having a manual paper feed tray 104 as a placement member on which paper S to be manually fed is placed.

An operation panel (operation display unit 3 ), which is input means for inputting print information, is arranged on the upper part of the copier 100 .
In the printer section 101, there is arranged a control section 150 for controlling each section of the copying machine 100 based on input information input from an external device such as a personal computer or an operation panel and detection information by a sensor.

FIG. 3 is a block diagram showing the main parts of copier 100. As shown in FIG.
The copying machine 100 includes a control section 150 as control means for controlling the entire copying machine 100. The control section 150 includes a CPU 150a as calculation means and an information storage section. The information storage unit includes a RAM 150b, a ROM 150c, a HDD (Hard Disk Drive), and the like, which store data. In this embodiment, for example, a ROM 150c containing a system OS, various control programs necessary for copy, facsimile, and printer processes, a printer PDL (Page Description Language) processing system, system initial setting values, etc.; It is composed of a RAM 150b and the like. The operation display unit 3 includes a display unit configured by a liquid crystal display or the like for displaying character information, etc., and an operation unit as operation reception means for receiving input information from an operator using a numeric keypad or the like and sending the input information to the control unit 150. It is

A space is formed between the scanner unit 300 and the printer unit 101 . Two stack sections 131 (131a, 131b) are formed above the printer section 101 positioned in this space, on which sheets S on which images are formed by the printer section 101 are discharged and stacked. Further, a sheet conveying path is formed for conveying the sheet S from the in-apparatus paper feed tray 103 or the manual feed tray 104 to the fixing device 120 through the image forming section 110 . Arrow "F" in FIG.

The image forming unit 110 includes a drum-shaped photoreceptor 111 which is an image carrier having a photosensitive layer on its surface. The photoreceptor 111 is rotatably supported by a side plate of the printer section 101, and rotated counterclockwise in FIG. 2 by a drive source. Around the photoreceptor 111, a charging roller 11 as a charging member, an irradiation exposure position of writing light L from an optical writing device 112, a developing device 113, a transfer roller 114 as a transfer member, a cleaning member, and the like are arranged in this order. .

The surface of the charging roller 11 is in contact with the surface of the photoreceptor 111 , the photoreceptor 111 rotates, and a uniform charge is supplied to the surface of the photoreceptor 111 by applying a charging bias to the charging roller 11 . be. As a result, the surface of the photoreceptor 111 is uniformly charged to a constant potential.

The optical writing device 112 irradiates the surface of the photosensitive member 111 with laser light emitted from a laser diode as writing light L based on image information of a document read by the scanner unit 300 or image information input from an external device. Optical scanning. By optically scanning the charged photoreceptor 111 , an electrostatic latent image is formed on the surface of the photoreceptor 111 .

The developing device 113 serves as a developer bearing member that faces the surface of the photoreceptor 111 and supplies toner, which is a developer, to the electrostatic latent image on the surface of the photoreceptor 111, developer density detection means, and developer transport means. A pair of conveying screws and the like are provided. With such a configuration of the developing device 113, the electrostatic latent image on the surface of the photoreceptor 111 is developed to form a toner image.

The surface of a rotatable transfer roller 114 contacts the surface of the photosensitive member 111 to form a transfer nip, and a transfer bias is applied to the transfer roller 114 from a transfer bias power source. The transfer roller 114 transfers the toner image formed on the surface of the photoreceptor 111 onto the sheet S conveyed to the transfer nip by applying a transfer bias.

A pair of registration rollers 107 for controlling the timing of transporting the sheet S to the transfer nip is arranged upstream of the transfer nip in the sheet transport direction.

A toner image formed on the surface of the photoreceptor 111 is transferred to the paper S fed from the paper feed tray 103 or the like in the apparatus and sent to the transfer nip by the pair of registration rollers 107 when passing through the transfer nip. . The paper S onto which the toner image has been transferred is conveyed to the fixing device 120, where the toner image is melted by heat and pressure, and the toner image is fixed on the paper S. FIG. The sheet S on which the toner image has been fixed is sequentially discharged and stacked as an output image (copy) on a stack section 131 (131a or 131b) by a sheet discharge roller pair 130 (130a or 130b).

The sheet S placed on the manual feed tray 104 of the manual paper feeder 105 is fed downstream in the sheet conveying direction by a manual feed pickup roller (pickup roller 40) as a feeding member. Then, only one sheet S is separated by a sheet feed roller 32 and a separation roller 34 that constitute a manual separation mechanism, which is separation feeding means for separating the fed sheet into one sheet. Then, the separated one sheet S is fed into the sheet conveying path and sent to the registration roller pair 107 .

The manual separation mechanism of this embodiment forms a separation nip with a pair of roller members (32, 34). When a plurality of sheets S enter the separation nip, only the uppermost sheet S is fed downstream in the sheet feeding direction, and the other sheets S are fed upstream in the sheet feeding direction. It is the structure which gives a conveying force. The manual separation mechanism is not limited to such a configuration. For example, other known configurations are used, such as a configuration in which a separation nip is formed by a belt member and a roller member, or a configuration in which a separation nip is formed by a roller that imparts a conveying force and a separation pad that inhibits movement in the conveying direction. be able to.

A paper feeder in the copying machine 100 is provided with an internal paper feed tray 103 for accommodating standard size paper S in the body of the printer section 101 . Further, the printer unit 101 is provided with a manual paper feeder 105 for handling printing on a sheet of a size that cannot be accommodated in the paper feed tray 103 in the apparatus, or on a small number of sheets S, or the like. The manual paper feeding device 105 includes a manual paper feeding tray 104 on which the paper S is manually placed, and feeds and conveys the paper S from the manual paper feeding tray 104 .

Next, the configuration of the sheet feeding device 30 as a sheet feeding device applicable to the manual sheet feeding device 105 in this embodiment will be described.
FIG. 1 is a perspective view showing the main parts of the sheet feeding device 30. As shown in FIG.
FIG. 4 is a cross-sectional view of a cross section indicated by symbol A in FIG.
FIG. 5 is a cross-sectional view of the cross-section indicated by symbol B in FIG.
FIG. 6 is a cross-sectional view of a cross-section indicated by symbol C in FIG.

The paper feeder 30 includes a paper feed roller 32 and a separation roller 34 . A pick-up arm 38 is also provided, one end of which is supported by a paper feed roller shaft 36 which is the rotating shaft of the paper feed roller 32 and which rotates around the paper feed roller shaft 36 . A pickup roller shaft 42 is arranged at the other end of the pickup arm 38 , and a pickup roller 40 is rotatably supported with respect to the pickup roller shaft 42 .

The pickup roller 40 is connected to the paper feed roller 32 via a drive transmission gear 41 . The control unit 150 shown in the block diagram of FIG. 3 drives the paper feed motor 140 to rotate the paper feed roller 32. Along with the rotation of the paper feed roller 32, the pickup roller 40 also rotates. there is The pickup arm 38 is urged by a torsion spring arranged on the pickup roller shaft 42 such that the other end (on the pickup roller 40 side) rotates downward.

A manual feed tray 104 is positioned below the pickup roller 40 . 1 and FIGS. 4 to 6 do not show the manual feed tray 104 for the sake of simplicity. On the downstream side of the manual feed tray 104 in the paper transport direction (sheet feed direction, leftward in FIG. 4), the paper S transported from the manual feed tray 104 passes through a separation nip where the paper feed roller 32 and the separation roller 34 abut. A transport guide 52 is provided for guidance.

As shown in FIG. 3, the control unit 150 is electrically connected to the paper detection sensor 160, the solenoid 62, and the paper feed motor 140 provided in the paper feeder 30, and controls their operations. A paper detection sensor 160 is a sensor that detects the presence or absence of paper S on the manual feed tray 104 .

A paper stopper 56 is provided above between the manual feed tray 104 and the transport guide 52 as an abutting member rotatably supported by a stopper shaft 54 fixed to the housing of the paper feeder 30 . The paper stopper 56 has a first stopper arm 56a and a second stopper arm 56b extending in a direction (parallel to the ZX plane) orthogonal to the longitudinal direction (Y-axis direction) of the stopper shaft 54. there is The first stopper arm 56a and the second stopper arm 56b extend from the stopper shaft 54 in mutually different directions.

As shown in FIG. 5, above the paper stopper 56, a paper stopper rotation regulating member 60 is rotatably supported by a regulating member shaft 58 fixed to the housing of the paper feeder 30. is provided. The paper stopper rotation regulating member 60 has a regulating member arm 60 a extending perpendicularly to the longitudinal direction of the regulating member shaft 58 . As shown in FIG. 5, the regulating member arm 60a is provided with a locking portion 60a1 so as to lock the locked portion 56b1 of the stopper second arm 56b of the sheet stopper 56. As shown in FIG.

The position of the paper stopper 56 in the state shown in FIG. 5 is the position where the first stopper arm 56a stands by to stop the leading edge of the paper S when the stack of paper S is pushed into the manual feed tray 104 (hereinafter referred to as " It is referred to as "the abrupt position"). That is, even if the paper stopper 56 is pushed by the leading edge of the paper S and tries to rotate counterclockwise in FIG. The paper stopper 56 is held at the abutting position by being locked by the locking portion 60a1 of the member arm 60a so that the paper stopper 56 does not rotate in the counterclockwise direction.

Further, the paper stopper rotation restricting member 60 is urged to rotate in the direction indicated by arrow D in FIG. The biasing member that biases the paper stopper rotation restricting member 60 to rotate is not limited to the torsion spring, and other elastic members such as springs can be used. Alternatively, depending on the positional relationship between the position of the center of gravity of the paper stopper rotation restricting member 60 and the restricting member shaft 58, gravity may exert an urging force similar to the urging force of the torsion spring for urging the restricting member. good.

FIGS. 7A and 7B are perspective views of the paper stopper 56 at the abutting position, viewed from different directions. In the states of FIGS. 7A and 7B, the solenoid 62 is in the OFF state.
FIGS. 8A and 8B are perspective views of the paper stopper 56 at the retracted position, viewed from different directions. In the states of FIGS. 8(a) and 8(b), the solenoid 62 is in the ON state.
9(a) and 9(b) are perspective views of the state in which the sliding surface 56b2 of the paper stopper 56 and the sliding projection 60a2 of the paper stopper rotation regulating member 60 are in contact with each other, viewed from different directions. be.

The sheet feeding device 30 is provided with a solenoid 62 and a solenoid link 66 rotatably supported by a link support shaft 64 fixed to the housing of the sheet feeding device 30 . The solenoid link 66 has a connection portion 66 a that is connected to the movable iron core 68 of the solenoid 62 . The connecting portion 66a is connected to the movable iron core 68 of the solenoid 62 so as to be rotatable about a rotating shaft 68a orthogonal to the advancing/retreating direction of the movable iron core 68. As shown in FIG. A tension spring 67, one end of which is supported by the housing, is attached to the connecting portion 66a of the solenoid link 66 to urge the connecting portion 66a in the direction of arrow E in FIG.

When the solenoid 62 is turned on, the movable iron core 68 is pulled toward the main body of the solenoid as indicated by arrow F in FIG. to move. As a result, the solenoid link 66 rotates clockwise in FIG. 8 around the link support shaft 64 . On the other hand, when the solenoid 62 is turned off, the connecting portion 66a of the solenoid link 66 moves in the direction in which the movable iron core 68 is pulled out from the main body of the solenoid by the biasing force of the tension spring 67, as indicated by arrow E in FIG. As a result, the solenoid link 66 rotates counterclockwise in FIG. 7 around the link support shaft 64 .

The solenoid link 66 also has a vertically moving portion 66b that pushes up the pushed portion 59 integrally provided with the paper stopper rotation restricting member 60 rotatably supported by the restricting member shaft 58 from below. When the solenoid 62 is turned on and the solenoid link 66 rotates around the link support shaft 64 in the clockwise direction in FIG. pushes up the push-up portion 59 integrated with the paper stopper rotation restricting member 60 against the urging force of . As a result, the paper stopper rotation restricting member 60 rotates around the restricting member shaft 58 in the direction in which the restricting member arm 60a moves upward. That is, the locking portion 60a1 of the paper stopper rotation regulating member 60 locks the locked portion 56b1 of the stopper second arm 56b of the paper stopper 56 from the locking position (state shown in FIG. 7). The paper stopper rotation restricting member 60 rotates to the unlocked position (the state shown in FIG. 8).

In this manner, the paper stopper 56, which is unlocked by the paper stopper rotation regulating member 60, moves from the abutment position (the state shown in FIG. 7) where the first stopper arm 56a abuts the paper S (the state shown in FIG. 7). 56a is rotatable about the stopper shaft 54 to the retracted position (state shown in FIG. 8) where the sheet S is not hit. As a result, the paper feeding operation is started after that, and the front end of the paper S in the paper feeding direction can push aside the stopper first arm 56a, and the paper S can be transported. When the sheet S is fed and the leading edge of the sheet S pushes away the stopper first arm 56a, the sheet stopper 56 rotates from the abutting position to the retracted position, and enters the state shown in FIG.

5 and 6, the depressed portion 38a of the pickup arm 38 is positioned below the vertically moving portion 66b of the solenoid link 66. As shown in FIGS. The depressed portion 38 a of the pickup arm 38 extends on the side opposite to the pickup roller 40 with respect to the paper feed roller shaft 36 that rotatably supports the pickup arm 38 . As described above, since the pickup arm 38 is rotationally urged by the torsion spring in the direction in which the pickup roller 40 moves downward, the pressed portion 38a side is rotationally urged in the direction in which the pickup roller 40 moves upward.

When the solenoid 62 is turned on, the vertically movable portion 66b of the solenoid link 66, which presses from above the pressed portion 38a urged upward by the torsion spring, moves upward. As a result, the pick-up arm 38 rotates in the direction indicated by symbol H1 in FIG. 6 due to the biasing force of the torsion spring. As a result, the pickup roller 40 supported by the pickup arm 38 moves downward and comes into contact with the upper surface of the uppermost sheet S set on the manual feed tray 104 . In this state, by rotating the pickup roller 40 connected to the paper feed roller 32 by the paper feed motor 140, the uppermost paper S set on the manual feed tray 104 can be sent out to the separation nip. .

On the other hand, when the solenoid 62 is turned off and the solenoid link 66 rotates counterclockwise in FIG. 7 around the link support shaft 64, the vertical movement portion 66b of the solenoid link 66 moves downward. As a result, the pushed-down portion 38a of the pickup arm 38 contacts the vertically moving portion 66b and is pushed down, and the pickup arm 38 rotates in the direction of H2 in FIG. 6 against the biasing force of the torsion spring. As a result, the pickup roller 40 supported by the pickup arm 38 moves upward and separates from the upper surface of the sheet S set on the manual feed tray 104 .

Further, when the solenoid 62 is turned off and the vertically movable portion 66b of the solenoid link 66 moves downward, the vertically movable portion 66b is separated from the lower surface of the pushed portion 59 of the paper stopper rotation restricting member 60. As a result, the paper stopper rotation restricting member 60 can be rotated in the direction of arrow D in FIG. 7 by the biasing force of the restricting member biasing torsion spring.

At this time, when the paper stopper 56 is rotated to the abutment position (the state shown in FIG. 7), the paper stopper rotation regulating member 60 is configured so that the engaging portion 60a1 of the paper stopper 56 stops the second stopper arm 56b of the paper stopper 56. is rotated to a locking position for locking the locked portion 56b1. On the other hand, when the paper stopper 56 is rotated to the retracted position (the state shown in FIG. 8) due to the leading edge of the paper S pushing away the first stopper arm 56a, the regulating member of the paper stopper rotation regulating member 60 A sliding protrusion 60a2, which is a sliding portion provided at the tip of the arm 60a, contacts a sliding surface 56b2, which is a sliding portion provided on the stopper second arm 56b of the paper stopper 56. As shown in FIG. In this case, the paper stopper rotation restricting member 60 does not rotate to the locking position.

Due to the positional relationship between the center of gravity of the paper stopper 56 and the stopper shaft 54, the paper stopper 56 of this embodiment has a biasing force (biasing force in the direction of symbol G in FIG. 8A) that tends to return from the retracted position to the abutment position due to gravity. ) works. Of course, an urging means such as a spring may be provided to apply a similar urging force (rotational force). Due to this biasing force (rotational force) acting, the sheet S set in the manual feed tray 104 starts to be fed, and the leading edge of the sheet S pushes the first stopper arm 56a to the sheet stopper. After the sheet stopper 56 has been rotated to the retracted position, if there is no sheet S below the first stopper arm 56a, the sheet stopper 56 can be rotated from the retracted position to the abutting position by gravity. However, when the paper feed operation is started, a plurality of sheets S are normally sent to the separation nip consisting of the paper feed roller 32 and the separation roller 34 in a state of being piled up. Even after being separated and conveyed, the state in which the paper S exists below the first stopper arm 56a continues. Therefore, normally, the tip of the stopper first arm 56a of the paper stopper 56 contacts the upper surface of the paper S below it and rotates to the abutment position until the paper S set on the manual feed tray 104 runs out. no.

When the sheet set on the manual feed tray 104 runs out, the sheet S does not exist below the first stopper arm 56a, and the sheet stopper 56 may rotate from the retracted position to the abutment position due to gravity. can. At this time, since the solenoid 62 is turned off, the sliding protrusion 60a2 of the paper stopper rotation restricting member 60 contacts the sliding surface 56b2 of the paper stopper 56 due to the biasing force of the torsion spring for biasing the restricting member. in contact with Therefore, the sheet stopper 56 rotates from the retracted position to the abutting position while the sliding projection 60a2 slides on the sliding surface 56b2. Therefore, when the paper stopper 56 rotates from the retracted position to the abutting position, it receives rotational resistance due to the frictional force between the sliding projection 60a2 and the sliding surface 56b2.

When the paper stopper 56 rotates from the retracted position to the abutting position, the sliding projection 60a2 of the paper stopper rotation restricting member 60 reaches the sliding direction downstream end of the sliding surface 56b2. The sliding direction downstream side of the sliding direction downstream end of the sliding surface 56b2 is a step portion 56b4 as shown in FIG. Therefore, when the sliding protrusion 60a2 of the paper stopper rotation restricting member 60 reaches the sliding direction downstream end of the sliding surface 56b2, the sliding protrusion 60a2 moves toward the stepped portion 56b4 due to the biasing force of the restricting member biasing torsion spring. side, and the paper stopper rotation restricting member 60 rotates.

By this rotation, the engaging portion 60a1 of the paper stopper rotation regulating member 60 is moved to a position where the engaged portion 56b1 of the stopper second arm 56b of the paper stopper 56 is engaged (relative to the engaged portion 56b1). 56 in the direction of rotation from the abutment position to the retracted position). That is, the paper stopper rotation restricting member 60 rotates from the unlocked position to the locked position. As a result, the paper stopper 56 that has been rotated to the abutment position is restricted from rotating to the retracted position, and the paper stopper 56 is pushed by the leading edge of the paper S and moves counterclockwise in FIG. Even if it tries to rotate, the engaged portion 56b1 of the second stopper arm 56b is engaged with the engaging portion 60a1 of the restricting member arm 60a of the paper stopper rotation restricting member 60, and the paper stopper 56 moves counterclockwise. The paper stopper 56 is held at the abutting position without rotating.

A series of sheet feeding operations in the sheet feeding device 30 of this embodiment is summarized as follows.
When the paper feeding operation is stopped, the solenoid 62 is turned off, and as shown in FIG. 7, the movable iron core 68 is pulled out from the solenoid body by the biasing force of the tension spring 67 (arrow E in FIG. 7). direction). At this time, the solenoid link 66 rotates about the link support shaft 64 in the counterclockwise direction in FIG. 7, and the vertical movement portion 66b of the solenoid link 66 is lowered. As a result, the pushed-down portion 38a of the pickup arm 38 is pushed down by the vertical movement portion 66b, the pickup arm 38 rotates in the direction H2 in FIG. 6, and the pickup roller 40 rises.

Further, when the paper feeding operation is stopped, the paper stopper 56 is rotated to the abutment position (the state shown in FIG. It is rotated to the locking position where the locked portion 56b1 is locked. Therefore, even when the stack of sheets S is set in the manual feed tray 104 so as to pierce the stack of sheets S in the paper feed direction, the leading edge of the stack of sheets S hits the stopper first arm 56a of the sheet stopper 56. , it is possible to prevent the sheet S from being thrust into the separation nip formed by the paper feed roller 32 and the separation roller 34 .

When the bundle of sheets S set in the manual feed tray 104 is forcefully inserted toward the separation nip by hand, the number of sheets S that is larger than the maximum number of sheets S expected to reach the separation nip at the time of feeding. S may reach the separation nip. If the sheets are fed in this state, the sheets S cannot be completely separated at the separation nip, and multiple sheets S may be fed to the sheet conveying path in the printer section 101, causing multi-feeding. In addition, if the stack of sheets S is manually inserted into the separation nip while being tilted, skewing may occur. In addition, when the bundle of paper S is forcefully inserted toward the separation nip by hand, the leading end of the bundle of paper S is bent by the paper feed roller 32 or the separation roller 34, degrading the print quality or There is a risk of causing a jam inside.

In the paper feeding device 30 of the present embodiment, even if a bundle of paper S set in the manual feed tray 104 is manually inserted into the separation nip, the paper held by the paper stopper rotation restricting member 60 is prevented from being manually inserted into the separation nip. The first stopper arm 56a of the stopper 56 abuts the stack of sheets S, and the stack of sheets S can be prevented from further entering the downstream side in the sheet feeding direction. Therefore, it is possible to prevent the stack of sheets S from being inserted into the separation nip, thereby preventing the above-described double feeding, deterioration of print quality, and occurrence of jams during printing. Further, by aligning the position of the leading edge of the paper S with the paper stopper 56, occurrence of skew can be prevented.

When the paper feeding operation is started, prior to the paper feeding operation, the control section 150 starts driving the paper feeding motor 140 and the paper feeding roller 32 is rotationally driven. As the paper feed roller 32 rotates, the drive is also transmitted to the pickup roller 40 via the drive transmission gear 41, and the pickup roller 40 in the raised state is also rotationally driven. The separation roller 34 whose surface is in contact with the surface of the paper feed roller 32 rotates as the paper feed roller 32 rotates.

After that, when the control unit 150 turns on the solenoid 62, the movable iron core 68 is pulled toward the main body of the solenoid against the biasing force of the tension spring 67 (in the direction of arrow F in FIG. 8). As a result, the solenoid link 66 rotates in the clockwise direction in FIG. 8 around the link support shaft 64, and the vertically movable portion 66b of the solenoid link 66 rises. As a result, the pushed-up portion 59 of the paper stopper rotation regulating member 60 is pushed up, and the paper stopper rotation regulating member 60 moves from the stopper second arm 56b of the paper stopper 56 to the stopper portion 60a1 of the paper stopper rotation regulating member 60. from the locking position (state shown in FIG. 7) where the locked portion 56b1 is locked to the unlocking position (state shown in FIG. 8) where the locking is released. As a result, the paper stopper 56 can be rotated from the abutting position (the state shown in FIG. 7) to the retracted position (the state shown in FIG. 8).

Further, when the solenoid 62 is turned on, the vertically moving portion 66b of the solenoid link 66, which presses the pressed portion 38a of the pickup arm 38 from above, rises. 40 is rotated in a direction to lower it. As a result, the rotationally driven pickup roller 40 comes into contact with the uppermost paper sheet S on the manual feed tray 104, and a conveying force is applied to the paper sheet S in the conveying direction.

The uppermost sheet S of the manual feed tray 104 is picked up from the manual feed tray 104 by the pickup roller 40 and conveyed toward the separation nip where the paper feed roller 32 and the separation roller 34 are in contact with each other. At this time, the sheet S collides with the first stopper arm 56a of the sheet stopper 56 while being conveyed. Therefore, the paper stopper 56 is not locked (restricted to rotate), the first stopper arm 56a is pushed aside, the paper passes through the abutment point by the paper stopper 56, and the paper feed roller 32 and the separation roller 34 come into contact with each other. It is conveyed towards the separation nip. When the first stopper arm 56a is pushed away by the leading edge of the sheet S, the sheet stopper 56 rotates from the abutment position to the retracted position against the biasing force of gravity.

The controller 150 turns off the solenoid 62 at a predetermined timing before the trailing edge of the sheet S passes through the pickup roller 40 . As a result, as shown in FIG. 7, the movable iron core 68 is pulled out from the solenoid body by the biasing force of the tension spring 67 (in the direction of arrow E in FIG. 7). As a result, the solenoid link 66 rotates counterclockwise in FIG. 7 about the link support shaft 64, and the vertical movement portion 66b of the solenoid link 66 descends. As a result, the depressed portion 38a of the pickup arm 38 is pushed down by the vertically moving portion 66b, and the pickup roller 40 of the pickup arm 38 returns to the raised state. The sheet S is transported by the paper feed roller 32 after the pickup roller 40 is lifted.

Further, when the solenoid 62 is turned off, the vertical movement portion 66b of the solenoid link 66 separates from the lower surface of the pressed portion 59 of the paper stopper rotation regulating member 60, and the paper stopper rotation regulating member 60 is activated for urging the regulating member. Due to the biasing force of the torsion spring, it becomes possible to rotate in the direction of arrow D in FIG. At this time, since the sheet S separated by the separation nip remains below the first stopper arm 56a of the sheet stopper 56, the tip of the first stopper arm 56a of the sheet stopper 56 is placed on the upper surface of the sheet S. It abuts and cannot be rotated to the abutting position and remains at the retracted position. Therefore, as shown in FIG. 8, the sliding protrusion 60a2 of the regulating member arm 60a of the paper stopper rotation regulating member 60 comes into contact with the sliding surface 56b2 of the stopper second arm 56b of the paper stopper 56, thereby preventing the paper stopper rotation. The movement restricting member 60 does not rotate to the locking position. Therefore, normally, the paper stopper 56 is positioned at the retracted position and the paper S set on the manual feed tray 104 is conveyed sequentially until the paper S set on the manual feed tray 104 runs out.

Next, features of the sheet feeding device 30 according to this embodiment will be described.
When the sheet S set in the manual feed tray 104 is exhausted, the paper stopper 56 rotates from the retracted position to the abutting position, and the paper stopper rotation regulating member 60 rotates to the locking position. , the sheet stopper 56 must be in a state in which rotation is restricted from the abutting position to the retracted position. However, when the paper stopper 56 rotates from the retracted position to the abutting position, it receives rotational resistance due to the frictional force between the sliding projection 60a2 and the sliding surface 56b2. Therefore, in the conventional configuration, there is a rotation blocking force (such as the aforementioned frictional force and the rotational load of the rotating shaft) that prevents the paper stopper 56 from rotating from the retracted position to the abutment position, and a force that prevents the paper stopper 56 from projecting from the retracted position. A state of equilibrium is reached in which the rotational force for rotating the paper stopper 56 to the present position (biasing force due to gravity acting on the paper stopper 56, etc.) is balanced, the paper stopper 56 cannot rotate, and the paper stopper 56 returns from the retracted position to the abutment position. Sometimes it was not possible.

FIG. 10 is an explanatory view showing the force received by the paper stopper 56' when the paper stopper 56' returns to the abutment position at the end of paper feeding in the paper stopper 56' and the paper stopper rotation regulating member 60' in the conventional configuration. is.
At the end of paper feeding, there is no more paper S in contact with the stopper first arm 56a' of the paper stopper 56', and the paper stopper 56' becomes rotatable from the retracted position to the abutment position by gravity. At this time, the sheet stopper rotation restricting member 60' receives an urging force in the direction of symbol D in FIG. ' receives the load F1' from the sliding projection 60a2' of the sheet stopper rotation regulating member 60' that abuts thereon. The load direction of this load F1' is the rotation direction (tangential direction) about the rotation center O2 of the paper stopper rotation regulating member 60' passing through the contact point T1 on the sliding surface 56b2' with which the sliding projection 60a2' contacts. ). The angle between the direction connecting the contact point T1 and the rotation center O1 of the paper stopper 56' and the direction of the load F1' is defined as the contact angle θ'.

Further, when the paper stopper 56' rotates toward the abutment position in the direction of symbol G in FIG. receive.
Further, the sheet stopper 56' receives gravity F3' at the gravity center position T2 of the sheet stopper 56' due to its own weight.

FIG. 11 is an explanatory diagram showing components of the force that the paper stopper 56' receives.
The forces F1', F2', F3' that the paper stopper 56' receives are resolved into tangential direction components (n) and normal direction components (t) with respect to the rotation center O1 of the paper stopper 56'. The paper stopper 56 ′ is rotatably supported by the stopper shaft 54 and slides and rotates on the peripheral surface of the stopper shaft 54 . The paper stopper 56' has a load F1' acting on the contact point T1 from the peripheral surface of the stopper shaft 54 and a normal direction component F1(t)'+F2(t)' of the sliding friction force F2', and a normal force, A normal force to the normal direction component F3(t)' of gravity F3' acting on the center of gravity position T2 is received. Therefore, as shown in FIG. 12, when the sheet stopper 56' rotates toward the abutting position in the direction of symbol G in FIG. An axial frictional force F4' corresponding to the normal force to +F2(t)' and an axial frictional force F5' corresponding to the normal force to F3(t)' are received.

As a result of the above, the rotational force for rotating the paper stopper 56' from the retracted position to the abutting position is the tangential component F1(n)' of the load F1 of the paper stopper rotation regulating member 60' and the tangential line of gravity F3'. There is a directional component F3(n)'. Further, as the rotation preventing force for preventing rotation of the paper stopper 56' from the retracted position to the abutment position, the tangential direction component F2(n)' of the sliding frictional force F2' acting on the sliding surface 56b2' , and shaft frictional forces F4′ and F5′ acting on the contact surface with the stopper shaft 54 exist.

FIG. 13 is an explanatory diagram for explaining the conditions for the paper stopper 56' to return to the abutment position.
Let R1′ be the distance from the rotation center O1 of the paper stopper 56′ to the point T1 where the rotation force F1(n)′ and the rotation blocking force F2(n)′ act. Also, let R2′ be the distance from the center of rotation O1 of the paper stopper 56′ to the point T2 where the rotational force F3(n)′ acts. Further, the distance from the rotation center O1 of the paper stopper 56' to the points T3 and T4 where the rotation blocking forces F4' and F5' act is defined as R3'. In this case, in order for the paper stopper 56' to rotate in the G direction and return to the abutting position after the paper feeding is completed, the following conditional expression (1) must always be satisfied.
R1′×(F1(n)′−F2(n)′)+
R2'×F3(n)'-R3'×(F4'+F5')>0 (1)

FIGS. 14(a) to 14(d) are explanatory diagrams for explaining the load F1' acting on the contact point T1 while the paper stopper 56' having the conventional configuration rotates from the retracted position to the contact position. .
At the end of paper feeding, as shown in FIG. 14A, the sliding protrusion 60a2' of the paper stopper rotation regulating member 60' is positioned near the upstream end of the slide surface 56b2' of the paper stopper 56' in the sliding direction. , and the paper stopper 56' receives a load F1a'. Thereafter, as shown in FIG. 14(b), the paper stopper 56' rotates around the rotation center O1 in FIG. Rotate counterclockwise. In the state shown in FIG. 14(b), the paper stopper 56' receives a load F1b'. Then, as shown in FIG. 14(c), when the sliding projection 60a2' slides to the vicinity of the downstream end in the sliding direction of the sliding surface 56b2' of the paper stopper 56', the paper stopper 56' receives the load F1c'. receive.

At this time, if the distances between the contact point T1a at the start of sliding, the contact point T1b during sliding, and the contact point T1c at the end of sliding and the rotation center O1 are R1a′, R1b′, and R1c′, respectively. , the tangential direction component F1a(n)' of the load F1a' at the contact point T1a at the time of sliding start rotates the paper stopper 56' in the direction of the arrow G in the figure (the direction toward the contact position). The condition for facing is R1a'>R1b'. Similarly, the condition for the tangential direction component F1b(n)' of the load F1b' at the contact point T1b in the middle of sliding to turn the paper stopper 56' in the direction of the arrow G in the drawing is , R1b'>R1c'. Therefore, by satisfying these conditions, the sliding projection 60a2' slides from the upstream end of the slide surface 56b2' of the paper stopper 56' to the downstream end in the sliding direction, and the contact point T1 is maintained. The applied load F1' can always generate a rotational force to rotate the paper stopper 56' in the direction of the arrow G in the figure.

Further, when the sliding projection 60a2' exceeds the sliding direction downstream end of the sliding surface 56b2', the sliding projection 60a2' is disengaged from the sliding surface 56b2', and the paper stopper rotation regulating member 60' is stopped. The urging force of the member urging torsion spring rotates in the direction of symbol D in the figure. As a result, as shown in FIG. 14(d), the engaging portion 60a1' of the paper stopper rotation restricting member 60' located upstream in the sliding direction of the sliding projection 60a2' is positioned on the sliding surface 56b2'. It faces the locked portion 56b1' of the paper stopper 56', which is a stepped portion located on the downstream side in the sliding direction with respect to the downstream end in the sliding direction. This state is a state in which the paper stopper 56 has rotated to the abutment position, and the paper stopper 56 thus rotated to the abutment position is restricted from rotating to the retracted position.

As shown in FIG. 14D, the state in which the rotation of the paper stopper 56' is restricted, that is, the locked portion 56b1' of the paper stopper 56' is moved to the locking portion 60a1' of the paper stopper rotation restricting member 60'. is locked, the distance from the contact point (locking position) T1d between the locking portion 60a1' and the locked portion 56b1' to the rotation center O1 is defined as R1d'. At this time, the engaging portion 60a1' located on the sliding direction upstream side of the sliding projection 60a2' beyond the sliding direction downstream end of the sliding surface 56b2' is positioned downstream of the sliding direction downstream of the sliding surface 56b2'. It is necessary that R1c'>R1d' in order to be properly engaged by being caught by the locked portion 56b1' located on the side.

As described above, in the conventional paper stopper 56′, the shape of the sliding surface 56b2′ and the locked portion 56b1′ of the paper stopper 56′ satisfies the condition of R1a′>R1b′>R1c′>R1d′. must be fulfilled.

However, the contact angle θ′ of the paper stopper 56′ cannot be increased due to layout restrictions (the paper stopper rotation regulating member 60′ cannot be positioned away from the stopper shaft 54 of the paper stopper 56′, etc.). It is often difficult. For example, in order to increase the contact angle θ' of the paper stopper 56', the difference between R1a' and R1b' and the difference between R1b' and R1c' of the sliding surface 56b2' of the paper stopper 56' is increased. However, this makes it difficult to satisfy R1c′>R1d′. It becomes difficult to catch on the portion 56b1' so that it can be locked properly.

As a result of the inability to increase the contact angle θ′ of the paper stopper 56′ in this way, the rotational force (the tangential component F1(n )') cannot be increased, and on the other hand, the normal direction component F1(t)' of the load F1' increases, so that the rotation inhibiting force due to the sliding friction force F2' and the shaft friction force F4' increases. . Therefore, the paper stopper 56' may not be able to rotate to the abutting position. In particular, the paper stopper 56' stops without rotating at the abutment point T1a at the start of sliding, and the paper stopper 56' cannot be rotated to the abutment position in many cases.

Therefore, as shown in FIG. 15, the paper stopper 56 in the present embodiment is arranged so that the locked portion 56b1 and the sliding surface 56b2 of the paper stopper 56 are aligned in the direction of the rotation center axis of the paper stopper 56 (horizontal direction in FIG. 15). ) are arranged at mutually different positions. As a result, for example, a structure (Rc<Rd) in which the locked portion 56b1 of the paper stopper 56 is arranged at a position farther from the rotation center O1 of the paper stopper 56 than the sliding surface 56b2 of the paper stopper 56 is adopted. It is also possible to As a result, even if there are layout restrictions as described above, the shape of the sliding surface 56b2 of the paper stopper 56 is adjusted so that the contact angle θ of the paper stopper 56 becomes large without considering the locking function. can be adopted. Also, the shape of the locked portion 56b1 of the paper stopper 56 can be determined so that the locking function can be appropriately exhibited without considering the contact angle θ of the paper stopper 56. FIG. As a result, the contact angle .theta. Therefore, it is possible to suppress the occurrence of a situation in which the paper stopper 56 cannot return to the abutting position.

FIGS. 16A to 16D are explanatory diagrams for explaining the load F1 acting on the contact point T1 while the paper stopper 56 in this embodiment rotates from the retracted position to the contact position. This corresponds to FIGS. 14(a)-(d).
As shown in FIGS. 16A to 16C, the paper stopper 56 of the present embodiment is configured such that the shape of the sliding surface 56b2 of the paper stopper 56 satisfies the condition of R1a>R1b>R1c. there is Moreover, when compared with the conventional configuration shown in FIGS. 14(a) to 14(d), although R1a≈R1a′, R1b<R1b′ and R1c<<R1c′, the sliding surface 56b2 is configured. As a result, as shown in FIGS. 16A to 16C, the contact angles θa to θc of the paper stopper 56 are different from the contact angles θa′ to θc of the conventional structure shown in FIGS. 14A to 14D. ' is larger than As a result, a sufficiently large contact angle θa can be obtained even at the contact point T1a at the start of sliding where the contact angle is most unlikely to increase. Therefore, compared with the conventional configuration, it is possible to increase the rotational force (the tangential direction component F1(n) of the load F1) due to the load F1 received from the paper stopper rotation restricting member 60. On the other hand, the normal line of the load F1 By reducing the directional component F1(t), it is possible to reduce the rotation inhibiting force due to the sliding friction force F2 and the shaft friction force F4. Therefore, the occurrence of a situation in which the paper stopper 56 cannot be rotated to the abutting position is suppressed.

Further, when the sliding projection 60a2 exceeds the sliding direction downstream end of the sliding surface 56b2, the sliding projection 60a2 is disengaged from the sliding surface 56b2, and the paper stopper rotation regulating member 60 moves to the torsion for urging the regulating member. The urging force of the spring rotates in the direction of symbol D in the figure. As a result, as shown in FIG. 16D, the engaging portion 60a1 formed near the middle of the restricting member arm 60a of the paper stopper rotation restricting member 60 is positioned at the same center axis direction position as the engaging portion 60a1. 56 b 1 of the paper stopper 56 arranged in the opposite direction. This state is a state in which the paper stopper 56 has rotated to the abutment position, and the paper stopper 56 thus rotated to the abutment position is restricted from rotating to the retracted position.

At this time, the paper stopper 56 of the present embodiment has R1d≈R1d′ as compared with the conventional configuration shown in FIG. 14(d). As for the locking and unlocking functions of the locking portion 60a1 of 60, the functions equivalent to those of the conventional configuration are retained.

Therefore, according to the present embodiment, the locking and releasing of the locking portion 60a1 of the paper stopper rotation regulating member 60 with respect to the locked portion 56b1 of the paper stopper 56 are properly functioned, and the paper stopper 56 is contacted. It is possible to suppress the occurrence of a situation in which the paper stopper 56 cannot return to the abutting position due to the large tangent angle θ.

FIG. 17 is an explanatory diagram showing an example of layout constraints in this embodiment.
As shown in FIG. 17, the paper feed roller shaft 36 and the rotation bearing 37 are present near the paper stopper 56'. Therefore, the position where the paper stopper 56' can rotate counterclockwise in FIG. It is up to the position shown in FIG. 17(a). The position where the paper stopper 56' can rotate clockwise in FIG. 17(b).

Under such layout restrictions, the rotatable range of the paper stopper 56' is narrow. It is difficult to change the shape of the paper stopper 56' so as to increase the rotational force F3(n)' acting on the center of gravity position T2 by increasing the distance from the center O1 to the center of gravity position T2. This is because the clearances P1 and P2 between the paper stopper 56' and the paper feed roller shaft 36 and rotary bearing 37 are very small under the above layout restrictions.

In this embodiment, as shown in FIGS. 16A to 16C, the sliding protrusion 60a2 of the paper stopper rotation regulating member 60 and the sliding surface 56b2 of the paper stopper 56 are in contact with each other. The paper stopper rotation regulating member 60 and the paper stopper 56 are configured so as not to come into contact with each other except at the contact point between the sliding projection 60a2 and the sliding surface 56b2. Therefore, while the paper stopper 56' rotates to the abutment position, the portion other than the abutting portion between the sliding protrusion 60a2 and the sliding surface 56b2 (for example, the engaging portion 60a1 of the paper stopper rotation restricting member 60 and the (between the guide portion 56b3) of the paper stopper 56 facing the paper stopper 56), sliding between the paper stopper rotation regulating member 60 and the paper stopper 56 does not occur, the rotation blocking force is reduced, and the paper Occurrence of a situation in which the stopper 56 cannot return to the abutting position can be further suppressed.

Further, in this embodiment, as shown in FIG. Other than the locking portion between the stopping portion 60a1 and the locked portion 56b1 (for example, between the sliding protrusion 60a2 of the paper stopper rotation regulating member 60 and the stepped portion 56b4 of the paper stopper 56 facing thereto), the paper The stopper rotation restricting member 60 and the paper stopper 56 are configured so as not to come into contact with each other. As a result, the locked state between the locking portion 60a1 and the locked portion 56b1 can be stabilized, and a situation in which the locking is released unintentionally can be avoided.

In addition, in this embodiment, there may be a relative positional deviation between the paper stopper 56 and the paper stopper rotation restricting member 60 in the direction of the central axis of rotation due to looseness during assembly. In this case, the sliding protrusion 60 a 2 of the paper stopper rotation regulating member 60 may deviate from the sliding surface 56 b 2 of the paper stopper 56 in the rotation center axis direction and come into contact with the paper stopper 56 . Therefore, in this embodiment, a positional deviation correcting means is provided for correcting the relative positional deviation between the paper stopper 56 and the paper stopper rotation regulating member 60 in the direction of the central axis of rotation.

The positional deviation correcting means in this embodiment is provided with a guiding portion 56b3 inclined toward the sliding surface 56b2 of the paper stopper 56 at the same position as the engaged portion 56b1 of the paper stopper 56 in the rotation center axis direction. is. As a result, the sliding projection 60 a 2 of the paper stopper rotation regulating member 60 slides against the sliding surface 56 b 2 of the paper stopper 56 due to the relative positional deviation between the paper stopper 56 and the paper stopper rotation regulating member 60 in the rotation center axis direction. , and comes into contact with the guide portion 56b3 of the paper stopper 56, the sliding projection 60a2 biased by the biasing force of the torsion spring for biasing the regulating member moves along the inclined surface of the guide portion 56b3. It slides and is guided to the sliding surface 56b2 of the paper stopper 56, and as a result, the relative positional deviation between the paper stopper 56 and the paper stopper rotation restricting member 60 is corrected.

It should be noted that, as in the paper feeding device 30 of the present embodiment, a configuration that does not include an urging member that urges the paper stopper 56 to return to the abutment position has a higher balance than a configuration that includes an urging member. condition can occur. However, by using the paper stopper 56 as in the present embodiment, the paper stopper 56 cannot return to the abutment position even if the above-described urging member is not provided and the balanced state is likely to occur. It can suppress the occurrence. Therefore, when the sheet S is set on the manual feed tray 104 , the sheet stopper 56 is positioned at the abutment position, and the movement of the sheet stopper 56 can be regulated by the sheet stopper rotation regulating member 60 .

Further, the configuration for rotating the paper stopper rotation regulating member 60 in the direction indicated by D in FIG. It is good also as a structure rotated by.

An image forming apparatus equipped with a sheet feeding device according to the present invention is not limited to a copier. The sheet feeding apparatus according to the present invention can be used in an image forming apparatus having functions such as a printing apparatus, an inkjet recording apparatus, a printer, a copier, or a facsimile machine.
Further, the image forming apparatus equipped with the sheet feeding device according to the present invention is not limited to the electrophotographic apparatus such as the copier 100 described above, and can be applied to an inkjet apparatus.

The sheet conveyed by the sheet feeding apparatus according to the present invention is not limited to the recording medium such as the sheet S. Further, the sheet feeding device is not limited to the manual feeding device used in the image forming device, but any device other than the image forming device as long as it feeds a plurality of stacked sheets. It is also applicable to

As a device for feeding a plurality of stacked sheets, an automatic document feeder such as the ADF 200 shown in FIG. 2 is also applicable. The ADF 200 shown in FIG. 2 feeds one sheet positioned at the top of the stack of documents placed on the document table 201 into the main body of the ADF 200, passes the reading position of the scanner unit 300, and ejects the document. Eject to paper tray 202 . As document feeding means for feeding documents placed on the document table 201 in the ADF 200, it is possible to apply a sheet feeding device according to the present invention having a configuration similar to that of the sheet feeding device 30 described above. can.

Sheets to be fed by the sheet feeding apparatus according to the present invention include not only sheet-like members but also thin plate-like members. Sheets include paper, cloth, resin sheets, front and back protective paper, metal sheets, metal foils such as copper foils, electronic circuit board materials with plating, special films, plastic films, prepregs, and electronic circuits. Including substrate sheets. A prepreg is a sheet-like material in which carbon fibers or the like are impregnated with a resin in advance. As an example of prepreg, a fibrous reinforcing material such as carbon fiber or glass cloth is impregnated with a thermosetting resin mixed with additives such as a curing agent and a coloring agent, and then heated or dried to a semi-cured state. sheet-like reinforced plastic molding compound.

What has been described above is only an example, and each of the following aspects has a unique effect.
[First aspect]
The first mode includes an abutting portion (for example, the first stopper arm 56a) against which the leading end of the sheet (for example, the paper S) in the feeding direction abuts, and the abutting portion hits the sheet at the abutment position and the retracted position where the abutting portion does not hit the sheet. Rotation of the abutment member from the abutment position to the retracted position is prevented by locking the rotatable abutment member (for example, the paper stopper 56) and the engaged portion 56b1 of the abutment member. An engaging portion 60a1 for restricting is provided, and an engaging member (e.g., a paper stopper rotating portion) is rotatable between an engaging position where the engaging portion engages the engaged portion and an unlocking position where the engagement is released. and a movement restricting member 60), and the locking member moves in the locking direction D toward the locking position from the unlocked position by its own weight or biasing means (for example, a torsion spring for biasing the restraining member). A locking biasing force is applied, and the sliding portion of the locking member (for example, the sliding protrusion 60a2) and the slidable portion of the abutment member (for example, the sliding surface 56b2) slide. When the abutting member rotates from the retracted position to the abutting position, and the abutting member rotates to the abutting position, the sliding portion is disengaged from the slidable portion, and the locking member moves to the locking position. A sheet feeding device (e.g., sheet feeding device 30) that rotates to the locking position by an urging force, wherein the abutting member connects the locked portion and the slidable portion to each other by the rotation of the abutting member. It is characterized in that they are provided at mutually different positions in the central axis direction.

At the end of feeding, the sliding portion of the locking member and the slid portion of the abutting member are in contact with each other due to the locking urging force of the locking member, so the abutting member can move from the retracted position to the abutting position. During rotation, the sliding portion of the locking member and the slid portion of the abutting member slide. Then, when the abutment member rotates to the abutment position against this sliding resistance, the sliding portion is disengaged from the slidable portion, the locking member can rotate to the locking position, and the urging force engages. The stop member rotates to the locked position. As a result, the locked portion of the abutment member is locked by the locking portion of the locking member, and the abutment member positioned at the abutment position is restricted from rotating to the retracted position. As a result, even if the leading edge of the newly set sheet attempts to enter the feeding direction downstream side of the target set position, the abutting portion of the abutting member can prevent the entry.

In the conventional structure, the abutment member could not return to the abutment position at the end of feeding. This is due to the rotation prevention force (frictional force between the sliding portion of the locking member and the slid portion of the abutment member, etc.) that prevents the abutment member from rotating from the retracted position to the abutment position, and the abutment member. This is caused by a balanced state in which the rotational force that rotates the member from the retracted position to the abutted position is balanced. In order to prevent such a balanced state from occurring, it is necessary to make the rotational force sufficiently large with respect to the rotation inhibiting force.

However, if the rotational force for rotating the abutment member from the retracted position to the abutment position is increased, the abutment portion of the abutment member to which the abutment member is applied with this rotational force may, at the start of the feeding operation, for example, for a sheet such as thin paper. cannot be pushed aside by the leading edge of the sheet, and a feeding failure may occur. Further, if a drive mechanism is provided to rotate the abutment member from the abutment position to the retracted position in order to prevent this, the structure becomes complicated and the cost increases. Therefore, there is a limit to increasing the rotational force for rotating the abutment member from the retracted position to the abutment position. Therefore, in order to prevent the occurrence of a balanced state, it is important to reduce the rotation-preventing force that prevents the abutment member from rotating from the retracted position to the abutment position.

Here, if the frictional force between the sliding portion of the locking member and the slid portion of the abutting member can be reduced, the rotation blocking force can be reduced. In order to reduce this frictional force, the contact angle of the sliding portion of the locking member with respect to the slid portion of the contact member, that is, the normal direction of the slid portion at the contact point It is desirable to make the angle formed by the contact direction of the sliding portion with respect to the portion as large as possible. If this contact angle is large, it is possible to reduce the vertical component of the contacting biasing force of the locking member that increases the frictional force, thereby reducing the rotation inhibiting force.

However, in the conventional structure, the sliding portion of the locking member and the locking portion are made of the same member, and the sliding portion (locking portion) of the locking member slides on the slid portion of the abutting member. After sliding to the downstream end in the direction, the sliding portion (locking portion) is dropped into the stepped portion (locked portion) formed at the downstream end by the locking biasing force, and the abutment member is locked. was configured to be In such a configuration, the locked portion and the slidable portion of the abutment member are arranged at the same position in the rotation center axis direction of the abutment member, so that the locked portion of the abutment member does not abut. There are significant structural restrictions, such as the fact that the abutting member must be arranged at a position closer to the center of rotation of the abutting member than the slid portion of the member. As a result, the locking and releasing of the locking portion of the locking member with respect to the locked portion of the abutment member can be appropriately performed, and the contact of the sliding portion of the locking member with respect to the slid portion of the abutment member can be achieved. It has been difficult to increase the tangent angle to suppress the occurrence of the equilibrium state described above.

Therefore, in this aspect, the engaged portion and the slidable portion of the abutment member are arranged at mutually different positions in the direction of the rotation center axis of the abutment member. As a result, structural restrictions such as the need to dispose the locked portion of the abutting member at a position closer to the rotation center of the abutting member than the sliding portion of the abutting member are reduced. As a result, the slidable portion of the abutting member and the sliding portion of the locking member are configured so that the contact angle of the sliding portion of the locking member with respect to the slidable portion of the abutting member can be increased. The engaged portion of the abutment member and the engaging portion of the engaging member are configured so that the engagement and release of the engaging portion of the engaging member with respect to the engaged portion of the abutment member are appropriately performed. be possible. As a result, while the engagement and release of the engaging portion of the engaging member with respect to the engaged portion of the abutting member are properly functioned, the occurrence of the above-described balanced state is suppressed, and the abutment occurs at the end of feeding. It is possible to suppress the occurrence of a situation in which the member does not return to the abutting position.

[Second aspect]
A second aspect is characterized in that, in the first aspect, the abutting member is arranged such that the slidable portion is arranged further away from the rotation center of the abutting member than the locked portion. It is.
According to this structure, the locking and releasing of the locking portion of the locking member with respect to the locked portion of the abutting member can be appropriately performed, and the occurrence of the above-described balanced state can be suppressed, so that when the feeding is finished, the It is possible to achieve a configuration that can suppress the occurrence of a situation in which the abutment member does not return to the abutment position with a simple configuration.

[Third aspect]
According to a third aspect, in the first or second aspect, the abutting member is provided with an abutting urging force in an abutting direction from the retracted position to the abutting position by its own weight or an urging means. It is characterized by
According to this, the contact urging force can increase the rotational force for rotating the contact member from the retracted position to the contact position. While appropriately functioning the locking and releasing of the rollers, it is possible to suppress the occurrence of the above-described balanced state, thereby suppressing the occurrence of a situation in which the abutment member does not return to the abutment position at the end of feeding. Cheap.

[Fourth aspect]
According to a fourth aspect, in any one of the first to third aspects, when the sliding portion of the locking member and the slidable portion of the abutment member are in contact with each other, the sliding portion and the slidable portion It is characterized in that the engaging member and the abutment member are configured so as not to contact each other except for the contact portion with the moving portion.
According to this, while the abutting member rotates to the abutting position, sliding between the abutting member and the locking member does not occur except at the abutting portion between the sliding portion and the slidable portion. Therefore, the rotation blocking force is reduced, and it is possible to further suppress the occurrence of a situation in which the abutment member cannot return to the abutment position.

[Fifth aspect]
According to a fifth aspect, in any one of the first to fourth aspects, when the locking portion of the locking member locks the locked portion of the abutment member, the locking portion and the locked portion It is characterized in that the locking member and the abutting member are configured so as not to come into contact with each other except for the locking portion with the stop portion.
According to this, the locked state between the locking portion and the locked portion can be stabilized, and a situation in which the locking is released unintentionally can be avoided.

[Sixth aspect]
According to a sixth aspect, in any one of the first to fifth aspects, positional deviation correction corrects a relative positional deviation between the abutment member and the locking member in the direction of the rotation center axis of the abutment member. It is characterized by having a means (for example, guide portion 56b3).
According to this, even if a relative positional deviation occurs between the abutting member and the locking member in the direction of the rotation center axis, the relative positional deviation is corrected by the positional deviation correcting means, and the sliding portion and the slidable member are corrected. The portion can slide properly, and the locking portion and the locked portion can be locked properly.

[Seventh aspect]
In a seventh aspect based on the sixth aspect, the positional deviation correcting means is such that the sliding portion of the locking member abuts on the same position on the abutting member as the locked portion in the rotation center axis direction. It is characterized by providing a guide portion 56b3 for sliding the sliding portion toward the slidable portion when the sliding portion is moved.
According to this, it is possible to correct the relative positional deviation in the rotation center axis direction between the abutment member and the locking member with a simple configuration.

[Eighth aspect]
According to an eighth aspect, in any one of the first to seventh aspects, locking member driving means ( For example, it is characterized by having a solenoid 62).
According to this, the locking member can be rotated between the locked position and the unlocked position by controlling the locking member driving means.

[Ninth aspect]
According to a ninth aspect, in the eighth aspect, a feeding member (for example, a pick-up roller 40) that feeds a sheet placed on a placing member (for example, a manual feed tray 104) while being in contact with or separated from the sheet is provided, and the feeding member is characterized in that the mounting member is brought into contact with and separated from the sheet in conjunction with the operation of the locking member driving means.
According to this, the device can be simplified and the cost can be reduced as compared with the case where the driving means for moving the delivery member to contact and separate is provided separately from the locking member driving means.

[Tenth Aspect]
In a tenth aspect based on the ninth aspect, the locking member driving means includes a rectilinear core member (for example, a movable iron core 68) that linearly moves when driven, and a linear motion of the rectilinear core member that performs a rotational motion. It is characterized in that the locking member is rotated from the locking position to the unlocking position.
According to this, it is possible to realize a configuration in which the locking member is rotated by the linear motion of the locking member driving means.

[11th aspect]
An eleventh aspect is image forming comprising image forming means (for example, image forming section 110) for forming an image on a sheet (for example, paper S) and feeding means for feeding the sheet toward the image forming means. The apparatus (for example, the copying machine 100) is characterized by using the sheet feeding device (for example, the sheet feeding device 30) according to any one of the first to tenth aspects as the feeding means.
According to this structure, the locking and releasing of the locking portion of the locking member with respect to the locked portion of the abutting member can be appropriately performed, and the occurrence of the above-described balanced state can be suppressed, so that when the feeding is finished, the The occurrence of a situation in which the abutment member does not return to the abutment position is suppressed. Therefore, it is possible to prevent the occurrence of double feeding or skewing caused by the sheet entering the downstream side in the feeding direction from the position where the sheet set at the time of sheet setting abuts against the abutting portion of the abutting member. Since the sheet can be fed, stable image formation can be performed.

[Twelfth aspect]
A twelfth aspect is characterized in that, in the eleventh aspect, the sheet feeding device is a manual sheet feeding device that feeds sheets placed on a manual feed tray 104 .
In the manual feed tray, the sheet tends to enter the downstream side in the feeding direction from the position at which the sheet is abutted against the abutment member when the sheet is set, but this problem can be prevented.

30: Paper feeder 32: Paper feed roller 34: Separation roller 36: Paper feed roller shaft 37: Rotary bearing 38: Pickup arm 38a: Depressed portion 40: Pickup roller 41: Drive transmission gear 42: Pickup roller shaft 52: Conveyance guide 54: Stopper shafts 56, 56': Paper stoppers 56a, 56a': Stopper first arms 56b, 56b': Stopper second arms 56b1, 56b1': Locked portions 56b2, 56b2': Slide surface 56b3 : Guide portion 56b4 : Step portion 58 : Regulating member shaft 59 : Pushed upper portions 60, 60': Paper stopper rotation regulating member 60a: Regulating member arms 60a1, 60a1': Locking portions 60a2, 60a2': Sliding projection 62 : Solenoid 64 : Link support shaft 66 : Solenoid link 66a : Connecting portion 66b : Vertically moving portion 67 : Tension spring 68 : Movable iron core 68a : Rotating shaft 100 : Copier 101 : Printer 103 : Paper feed tray 104 in device : Manual feed tray 105 : Manual feeder 107 : Registration roller pair 110 : Image forming section 120 : Fixing device 130 : Paper discharge roller pair 140 : Paper feed motor 150 : Control section 160 : Paper detection sensor 200 : ADF
300: scanner unit 400: paper feeding unit inside device

Patent No. 5128451

Claims (12)

an abutting member having an abutting portion with which the leading end of the sheet in the feeding direction abuts, the abutting member being rotatable between an abutting position at which the abutting portion abuts against the sheet and a retracted position at which the abutting portion does not abut against the sheet;
an engaging portion that restricts rotation of the abutting member from the abutting position to the retracted position by engaging the engaged portion of the abutting member, the engaging portion being the engaged portion; and a locking member rotatable between a locking position for locking and an unlocking position for releasing the locking,
The locking member is applied with a locking biasing force in a locking direction from the unlocking position to the locking position by its own weight or biasing means,
The abutment member rotates from the retracted position to the abutment position while the sliding portion of the locking member and the slid portion of the abutment member slide, and the abutment member moves to the abutment position. a sheet feeding device in which the sliding portion disengages from the slidable portion when rotated up to the position where the locking member rotates to the locking position by the locking urging force,
The sheet feeding device, wherein the abutting member has the engaged portion and the slidable portion at mutually different positions in a direction of a rotation center axis of the abutting member. The sheet feeding device according to claim 1,
The abutting member rotates from the retracted position to the abutting position, and in a state immediately before the sliding portion is separated from the slidable portion, the abutting member is moved from the portion of the slidable portion with which the sliding portion is in contact . 2. A sheet feeding device according to claim 1, wherein said engaging portion is arranged away from the center of rotation of said abutting member. In the sheet feeding device according to claim 1 or 2,
The sheet feeding device, wherein the abutment member is applied with an abutment biasing force in the abutment direction from the retracted position to the abutment position by its own weight or biasing means. The sheet feeding device according to any one of claims 1 to 3,
When the sliding portion of the locking member and the slid portion of the abutting member are in contact with each other, the locking member and the slidable portion other than the abutting portion between the sliding portion and the slid portion are in contact with each other. A sheet feeding device, wherein the abutment members are configured so as not to come into contact with each other. The sheet feeding device according to any one of claims 1 to 4,
When the engaging portion of the engaging member engages the engaged portion of the abutting member, the engaging member and the engaging portion other than the engaging portion between the engaging portion and the engaged portion are separated from each other. A sheet feeding device, wherein the abutment members are configured so as not to come into contact with each other. The sheet feeding device according to any one of claims 1 to 5,
A sheet feeding apparatus comprising positional deviation correcting means for correcting a relative positional deviation between the abutment member and the locking member in the direction of the rotation center axis of the abutment member. In the sheet feeding device according to claim 6,
When the sliding portion of the locking member comes into contact with the same position on the abutting member as the locked portion in the rotation center axis direction, the positional deviation correcting means moves the sliding portion to the locked portion. A sheet feeding device comprising a guide portion that slides toward the sliding portion. The sheet feeding device according to any one of claims 1 to 7,
A sheet feeding apparatus comprising locking member driving means for rotating the locking member from the locking position to the unlocking position against the locking biasing force. In the sheet feeding device according to claim 8,
having a delivery member that delivers the sheet while coming into contact with and separating from the sheet placed on the placement member;
A sheet feeding apparatus, wherein the sending member moves into contact with and separates from the sheet on the placing member in conjunction with the operation of the locking member driving means. In the sheet feeding device according to claim 9,
The locking member driving means includes a rectilinear core member which is linearly moved by driving, and a linear movement of the rectilinear core member to rotate the locking member from the locking position to the unlocking position. A sheet feeding device , comprising: a rotary motion member . an image forming means for forming an image on a sheet;
An image forming apparatus comprising feeding means for feeding the sheet toward the image forming means,
An image forming apparatus, wherein the sheet feeding device according to any one of claims 1 to 10 is used as the feeding means. The image forming apparatus according to claim 11, wherein
An image forming apparatus, wherein the sheet feeding device is a manual sheet feeding device that feeds a sheet placed on a manual feeding tray.

Images