SHEET CONVEYANCE APPARATUS AND IMAGE FORMING APPARATUS

A sheet conveyance apparatus includes a roller pair having first and second rollers, a roller holder having first and second guided portions, and a guiding portion having first and second guides. The first and second rollers can take a first state where the first roller contacts the second roller with a predetermined force and take a second state where the predetermined force is reduced. A first direction in which the first guide guides the first guided portion is inclined relative to a second direction in which the second guide guides the second guided portion. When viewed in a rotational axis direction of the first roller with the first and second rollers in the first state, an angle formed by a straight line passing through rotational centers of the first and second rollers and the first direction is smaller than an angle formed by the straight line and the second direction.

BACKGROUND

Field

The present disclosure relates to a sheet conveyance apparatus, and more particularly, to a sheet conveyance apparatus for conveying sheets such as recording sheets and document sheets, mounted on image forming apparatuses such as printers, facsimiles, and copying machines.

Description of the Related Art

A certain sheet conveyance apparatus is configured to bias one roller to the other roller to bring the rollers into contact with each other. In a known example of this configuration, the one roller is a drive roller rotating by a driving force of a drive source, and the other roller is a driven roller driven to rotate by the drive roller. Japanese Patent Application Laid-Open No. 2019-137517 discusses a configuration in which a driven roller holder for slidably and rotatably holding a driven roller is pressed by a spring, and the driven roller comes into contact with a drive roller.

SUMMARY

The present disclosure is directed to providing a sheet conveyance apparatus effectively using the space around rollers while restricting a large change of the sheet conveyance direction.

According to an aspect of the present disclosure, a sheet conveyance apparatus includes a roller pair configured to convey a sheet and including a first roller and a second roller, a biasing member, a roller holder configured to hold the first roller and to be biased by the biasing member so that the first roller is biased toward the second roller, wherein the roller holder includes a guided portion and the guided portion includes a first guided portion and a second guided portion positioned upstream of the first guided portion in a biasing direction of the biasing member, and a guiding portion including a first guide and a second guide, wherein the first guide is configured to movably support and guide the first guided portion, the second guide is configured to movably support and guide the second guided portion, and the guiding portion is configured to movably guide the roller holder so that the first and second rollers can take a first state where the first roller comes into contact with the second roller with a contact force that is a predetermined force and take a second state where the contact force is reduced from the predetermined force, wherein a first direction in which the first guide guides the first guided portion is inclined relative to a second direction in which the second guide guides the second guided portion, and wherein, when viewed in a rotational axis direction of the first roller in a case where the first and second rollers are in the first state, an angle formed by a straight line passing through rotational centers of the first and second rollers and the first direction is smaller than an angle formed by the straight line and the second direction.

DESCRIPTION OF THE EMBODIMENTS

FIGS.17A to17Cillustrate a conveyance roller pair of an image forming apparatus according to a comparative example. The conveyance roller pair includes a conveyance roller rotating by a driving force, and a driven roller driven to rotate by the conveyance roller.

In the configuration illustrated inFIG.17A, a driven roller24′ is slidably and rotatably held by a roller holder31′, and the roller holder31′ rotatable around a rotational center25c′ is pressed toward a conveyance roller23b′ by a spring (not illustrated). As a result, a nip of the conveyance roller pair (conveyance rollers23b′ and24′) is formed. However, when the intersecting angle λ between the conveyance direction T of the conveyance path for conveying a sheet to the nip of the conveyance roller pair (conveyance rollers23b′ and24′) and the conveyance direction N of the conveyance roller pair is an obtuse angle, the position of the rotational center25c′ overlaps with the conveyance path, and hence the rotational center25c′ may not be disposed.

The conveyance roller pair (conveyance rollers23b′ and24′) illustrated inFIG.17Bdischarges a sheet S onto a sheet discharge tray60′ for stacking sheets S. The driven roller24′ is rotatably held by the roller holder31′.

The roller holder31′ is provided with two pairs of bosses25a′ and25b′ in the direction perpendicular to the nip line. While sliding with a groove30′ as a part of a frame29′, the roller holder31′ pressed by a spring (not illustrated) linearly moves in the direction of a nip pressure F. The groove30′ is disposed so that the upstream boss25a′ and the downstream boss25b′ of the roller holder31′ are disposed on the line connecting the centers of the conveyance roller23b′ and the driven roller24′.

The conveyance direction N of the conveyance roller pair (conveyance rollers23b′ and24′) has an angle relative to the horizontal direction H and conveys the sheet S in the obliquely upward direction. However, in this configuration, allocating a space for disposing the spring, the roller holder31′, and the frame29′ will increase the distance HD from the outer diameter edge of the driven roller24′ of the frame29′ for holding the roller holder31′ in the horizontal direction H. The longer the distance HD, the higher the possibility that the trailing edge of the discharged sheet S is caught on the frame29′.

In the configuration illustrated inFIG.17C, the conveyance direction of the conveyance roller pair (conveyance rollers23b′ and24′) is an obliquely upward direction, and the driven roller holder24′ is linearly moved in the vertical direction. In the configuration where the linear movement direction of the driven roller holder24′ is different from the nip pressure direction of the conveyance roller pair (conveyance rollers23b′ and24′), if the conveyance roller23b′ is bent by the nip pressure and shifts from the solid-line position to the dotted-line position, the driven roller24′ moves from the solid-line position to the dotted-line position.

As a result, the driven roller24′ relatively rotates counterclockwise around the conveyance roller23b′. Therefore, the angle of the conveyance direction changes by the angle θ formed by the line connecting with the center of the conveyance roller pair (conveyance rollers23b′ and24′) drawn with a solid line, and the line connecting with the center of the conveyance roller pair (conveyance rollers23b′ and24′) drawn with a dotted line. Then, the conveyance direction changes from N1 to N2. Particularly if the outer diameter of the conveyance roller23b′ is small, the conveyance direction largely changes, possibly preventing the sheets S from being normally stacked on the sheet discharge tray.

As an example of a configuration of the image forming apparatus according to a first exemplary embodiment, an electrophotographic laser printer will be described below. The following describes an overall configuration of the image forming apparatus according to the present exemplary embodiment, and then describes a configuration of a sheet discharge unit of the image forming apparatus according to the present exemplary embodiment.

FIG.1is a cross-sectional view illustrating a configuration of an electrophotographic laser printer having a double-sided image forming function as an example of an image forming apparatus. Sizes, materials, shapes, and relative arrangements of components described in the following exemplary embodiments are not limited thereto. Unless otherwise specifically described, the scope of the present disclosure is not limited to the exemplary embodiments. The image forming apparatus according to the present exemplary embodiment is not limited to a laser printer but is applicable to copying machines, facsimiles, and other image forming apparatuses.

An image forming apparatus1illustrated inFIG.1roughly includes a sheet feeding unit, an image forming unit (a photosensitive drum3and a transfer roller9) for forming an image on a sheet, a fixing unit (fixing apparatus10), and a sheet discharge unit20.

The image forming apparatus1includes a process cartridge2attachable to and detachable from the apparatus main body. The process cartridge2includes a process unit including a photosensitive drum3, a developing unit (not illustrated), a charge roller (not illustrated), and the like. A scanner unit4disposed vertically above the process cartridge2emits light based on an image signal to the photosensitive drum3for exposure.

After the photosensitive drum3has been charged to a predetermined negative polarity potential by the charge roller (not illustrated), an electrostatic latent image is formed on the drum3by the scanner unit4. The electrostatic latent image is applied with negative-polarity toner by the developing unit (not illustrated) in the process cartridge2for reversal development, and a toner image is formed.

The sheet feeding unit includes a sheet feeding unit5aattached to the image forming apparatus1, and a sheet feeding cassette6afor storing sheets S attachable to and detachable from the image forming apparatus1. The sheets S stored in the sheet feeding cassette6aare separated and fed one by one from the sheet feeding cassette6aby the sheet feeding unit5athat is rotated by the power of a sheet feeding drive unit (not illustrated). A fed sheet S is conveyed to a registration roller pair8by a conveyance roller pair7a, and subjected to skew correction and conveyed to a transfer unit by the registration roller pair8.

A sheet feeding cassette6balso stores sheets S with a different size from or the same size as the sheets S in the sheet feeding cassette6a.

The transfer unit is configured to apply a positive-polarity bias to the transfer roller9by a bias application unit (not illustrated). Thus, a toner image is transferred as a non-fixed image onto the sheet S conveyed to the transfer unit.

The sheet S with the toner image transferred thereon is conveyed to the fixing apparatus10provided downstream of the transfer unit in the conveyance direction. The fixing apparatus10for fixing the toner image transferred on the sheet S includes a heat roller11as a fixing member heated by a heater as heating unit (not illustrated), and a pressure roller12as a pressurizing member rotating in pressure contact with the heat roller11. The sheet S is conveyed while being pinched by a fixing nip portion formed by the heated roller11and the pressure roller12. When the toner image is heated and pressurized, the toner image is fixed onto the surface of the sheet S.

Then, the sheet S with the toner image fixed thereto is discharged from the fixing apparatus10onto a sheet discharge tray60for stacking sheets S discharged by a sheet discharge roller pair22(described below) illustrated inFIGS.3A and3B.

The sheet discharge unit20that characterizes the present exemplary embodiment will be described below with reference toFIGS.2to10.

FIG.2illustrates a periphery of the sheet discharge roller pair22when viewed from the direction of the arrow H′ inFIG.1.FIGS.3A and3Bare cross-sectional views illustrating another periphery of the sheet discharge roller pair22. More specifically,FIG.3Ais a partial cross-sectional view taken along the A-A line inFIG.2, andFIG.3Bis a partial cross-sectional view taken along the B-B line inFIG.2.

The sheet discharge roller pair22includes a sheet discharge roller23as a second roller rotatably driven by a driving source (not illustrated). The sheet discharge roller pair22further includes a sheet discharge driven roller24as a first roller driven to rotate by the rotation of the sheet discharge roller23. The sheet discharge driven roller24, when pressed by a pressing spring26, comes into contact with the sheet discharge roller23to form a nip. As a result, the sheet S is conveyed while being pinched by the sheet discharge roller23and the sheet discharge driven roller24. The sheet discharge driven roller24is positioned vertically below the sheet discharge roller23.

The sheet discharge roller23includes a sheet discharge roller axis23a, and two rubber rollers23balong the direction of the sheet discharge roller axis23a, and brings the sheet discharge driven roller24into contact with each of the rubber rollers23b. The sheet discharge driven roller24is rotatably held to the roller holder31. The roller holder31is provided with a projection25that engages with a groove30(described below) to be movably regulated. The roller holder31is attachable to and detachable from the apparatus main body together with the sheet discharge driven roller24. The roller holder31has two different projections25(guided portions, to be guided portions): a first projection25b(first guided portion), and a second projection25a(second guided portion) positioned upstream of the first projection25bin the biasing direction of a biasing member (the pressing spring26to be described below).

A sheet discharge frame29(guiding portion) is a part of the frame of the main body of the image forming apparatus1. The sheet discharge frame29is provided with the groove30as an opening for storing the projections25. The groove30includes a first groove30b(first guide) for movably supporting and guiding the first projection25b, and a second groove30a(second guide) for movably supporting and guiding the second projection25a. In other words, the first projection25band the second projection25aare stored in the groove30, and the first projection25band the second projection25aare movably guided by a portion (plane) forming the first groove30band the second groove30a, respectively.

Thus, the sheet discharge frame29allows the roller holder31to be movable so that the sheet discharge roller23and the sheet discharge driven roller24come into pressure contact with each other (pressure contact state or first state) and come out of pressure contact (released state or second state).

According to the present exemplary embodiment, in a state where the sheet discharge roller23and the sheet discharge driven roller24are in pressure contact with each other, the sheet S can be conveyed. In a state where the sheet discharge roller23and the sheet discharge driven roller24are out of pressure contact, the rollers23and24are separable. Although, according to the present exemplary embodiment, both rollers are configured to be separable in a state where the rollers23and24are out of pressure contact, the present exemplary embodiment is not limited thereto. The pressure contact force between the rollers may be reduced to an extent that sheet S jam recovery is possible, i.e., a light contact state.

The groove30further includes an intermediate groove30cfor connecting the first groove30band the second groove30a. When the roller holder31is attached to the sheet discharge frame29, the second projection25apasses through the intermediate groove30c. More specifically, the first groove30band the second groove30aare provided at the portion where an opening is formed. Although, according to the present exemplary embodiment, a groove is provided as an opening on the sheet discharge frame29, the opening may have any desired shape, for example an oblong hole, as long as the opening guides the projections.

The first groove30bis inclined relative to the second groove30a. More specifically, the direction (first direction) in which the first groove30bguides the first projection25b, i.e., the direction in which the first projection25bmoves in the first groove30bis inclined relative to the direction (second direction) in which the second groove30aguides the second projection25a, i.e., the direction in which the second projection25amoves in the second groove30a.

In a relation where the first groove30bis inclined relative to the second groove30a, the angle formed by the first direction relative to the direction of the straight line passing through the rotational centers of the sheet discharge driven roller24and the sheet discharge roller23when viewed in the rotational axis direction of the sheet discharge driven roller24in a state where the sheet discharge driven roller24and the sheet discharge roller23are in pressure contact with each other is smaller than the angle formed by the second direction relative to the direction of the straight line.

Since the first groove30band the second groove30aare not parallel to each other, the roller holder31and the sheet discharge driven roller24move along the groove30, while rotating, relative to the apparatus main body. The moving locus of the sheet discharge driven roller24in this operation is different from the biasing direction and the directions of the first groove30band the second groove30a. According to the present exemplary embodiment, the first groove30band the second groove30aare formed so that the sheet discharge driven roller24moves toward the sheet discharge roller axis23a.

More specifically, the angle formed by the lines A2and A1is smaller than the acute angle formed by the lines A1and A3, where the line A1is the line along the first direction, the line A2is the line along the second direction, and the line A3is the straight line passing through the rotational centers of the sheet discharge driven roller24and the sheet discharge roller23. This means that the line A2forms an angle closer to the vertical direction than the line A3. When the roller holder31and the sheet discharge driven roller24move, while rotating, relative to the apparatus main body based on this relation between the lines A1, A2, and A3, the sheet discharge driven roller24moves toward the sheet discharge roller axis23a.

A more specific configuration of the lines A1, A2, and A3will be described below. According to the present exemplary embodiment, the line A2extends in the vertical direction. In other words, the second groove30aextends in the vertical direction. Referring toFIG.3B, the line A1is a result of rotating the line A2counterclockwise by an angle of 10 degrees (angle x=10°).

Referring toFIG.3B, the line A3is a result of rotating the line A1counterclockwise by an angle of 10 degrees, i.e., the line A3is a result of rotating the line A2counterclockwise by an angle of 20 degrees (angle y=10°). The direct distance between the first projection25band the second projection25ais 8 mm, and the direct distance between the first projection25band the rotational center of the sheet discharge driven roller24is 9 mm.

These angular configurations may be suitably changed according to the direction in which the sheet discharge driven roller24is to be biased. The angular ranges are represented by 0°<x<90° and 0°≤y<90°.

The pressing spring26(compression spring) as a biasing member is held at one end by the sheet discharge frame29and held at the other end by the roller holder31. Thus, the pressing spring26presses the sheet discharge driven roller24toward the sheet discharge roller23to bring the sheet discharge driven roller24and the sheet discharge roller23into pressure contact with each other. The biasing direction of the pressing spring26is in the vertically upward direction, and the angle relative to the extending direction of the second groove30ais smaller than the angle relative to the extending direction of the first groove30b. Although the present exemplary embodiment uses a compression spring as a biasing member, any member for pressing the roller holder31is suitably applicable.

A sheet discharge full load detection flag27is provided to be rotatable around a rotational center27c, as illustrated by the arrow a. The sheet S conveyed by the sheet discharge roller pair22presses the sheet discharge full load detection flag27and is conveyed to the sheet discharge tray60.

FIG.4Ais a cross-sectional view illustrating the image forming apparatus1when viewed in the direction of the arrow H′ illustrated inFIG.1.FIG.4Aillustrates only the sheet discharge frame29, the rubber roller23bas a part of the sheet discharge roller23, the sheet discharge driven roller24, and the roller holder31.FIG.4Bis a cross-sectional view taken along the C-C line inFIG.4A.FIG.5is a perspective view illustrating the roller holder31.

As illustrated inFIG.4B, the sheet discharge driven roller24is positioned at a position closer to the image forming unit than the sheet discharge roller23in the direction perpendicular to the axial directions of the sheet discharge roller23and the sheet discharge driven roller24and perpendicular to the vertical direction (the extending direction of the sheet discharge tray60when viewed from the vertical direction). More specifically, the sheet discharge driven roller24is positioned more on the front side of the image forming apparatus1than the sheet discharge roller23. With this configuration, the conveyance direction of the sheet S by the sheet discharge roller pair22is an upward direction (arrow N) by an angle β from the horizontal direction H. Therefore, the discharged sheet S is not unlikely to disturb the aligned sheets on the sheet discharge tray60.

As illustrated inFIG.5, the roller holder31supports one discharge driven roller24according to the present exemplary embodiment. The two roller holders31are disposed in the rotational axis direction of the sheet discharge driven roller24to form two different nip portions.

FIG.6illustrates the loci of the sheet discharge driven roller24and the roller holder31in a state where the position of the sheet discharge roller23is fixed.FIG.6illustrates four different positions: the starting position where the sheet discharge roller23and the sheet discharge driven roller24are in contact with each other, the position as a result of the movement of an upstream boss25aby a distance L below the starting position, the position as a result of the movement thereof by a distance L above the starting position, and the position as a result of the movement thereof by a distance2L above the starting position.

The above-described configuration enables the moving direction K of the sheet discharge driven roller24and the nip pressure direction F to be approximately in parallel. As a result, even if the sheet discharge roller axis23ais bent by the nip pressure, the angle of the conveyance direction N of the sheet S remains unchanged, thus achieving stable conveyance. This makes it possible to use a molding material having a low rigidity instead of a highly rigid metal as the sheet discharge roller axis23a, achieving cost reduction.

The inclination of the nip direction will be briefly described below with reference toFIGS.7A to7C and8A to8C.FIGS.7A to7Cillustrate states where the sheet discharge driven roller24and the roller holder31are inclined when the projection25moves while being guided by the groove30.FIG.7Aillustrates the sheet discharge driven roller24and the roller holder31in a simplified way, andFIGS.7B and7Cillustrate states where the projection25is guided by the groove30.

FIGS.8A to8Cillustrate the sheet discharge roller23and the sheet discharge driven roller24.FIG.8Aillustrates a state where a thin sheet S1is pinched by the sheet discharge roller23and the sheet discharge driven roller24.FIG.8Billustrates a state where the sheet discharge roller23and the sheet discharge driven roller24pinch a thick sheet S2when the sheet discharge driven roller24moves in the vertical direction as illustrated inFIG.17C.FIG.8Cillustrates a state where the sheet discharge roller23and the sheet discharge driven roller24pinch the thick sheet S2according to the present exemplary embodiment.

In a state where the sheet discharge driven roller24is in contact with the sheet discharge roller23as illustrated inFIG.7B, when the thick sheet S2passes through the nip portion formed by the sheet discharge roller23and the sheet discharge driven roller24, and then the sheet discharge driven roller24is retracted, the sheet discharge driven roller24moves to the position illustrated inFIG.7C. At this timing, a line Z1passing through the first projection25band the second projection25ainFIG.7Bis different in angle from a line Z2passing through the first projection25band the second projection25ainFIG.7C. In this way, the sheet discharge driven roller24and the roller holder31moves, while rotating, relative to the apparatus main body.

Referring toFIGS.8A to8C,FIG.8Billustrating a state where the sheet discharge driven roller24moves in the vertically downward direction is compared withFIG.8Cillustrating a state where the sheet discharge driven roller24moves in the lower right direction, with reference toFIG.8A. Referring toFIG.8A, the sheet discharge roller23and the sheet discharge driven roller24are in contact with each other at a contact point P1. Referring toFIG.8B, the sheet S2and the sheet discharge driven roller24are in contact with each other at a contact point P2. Referring toFIG.8C, the sheet S2and the sheet discharge driven roller24are in contact with each other at a contact point P3.

Referring toFIG.8B, the straight line passing through the rotational centers of the sheet discharge roller23and the sheet discharge driven roller24is referred to as a line A4. Referring toFIG.8C, the straight line passing through the rotational centers of the sheet discharge roller23and the sheet discharge driven roller24is referred to as a line A5.

Referring toFIG.8B, the sheet discharge driven roller24moves in the vertically downward direction by the thick sheet S2. Thus, the line A4inclines relative to the line A3. At this timing, the distance between the contact points P1and P2is L1 in the conveyance direction of the sheet S. Referring toFIG.8C, the line A5inclines relative to the line A3. Since the moving direction of the sheet discharge driven roller24is the lower right direction, the inclination between the lines A5and A3is smaller than the inclination between the lines A4and A3. The distance between the contact points P1and P3is L2 in the conveyance direction of the sheet S.

Since the moving direction of the sheet discharge driven roller24is different from that inFIG.8B, L2 is smaller than L1 (L1>L2). In the configuration of the present exemplary embodiment illustrated inFIG.8C, the conveyance direction of the sheet S is more unlikely to change than that in the configuration illustrated inFIG.8Bbecause of the difference (L1>L2). This means that the present exemplary embodiment provides an excellent discharge performance.

In the above descriptions, the thick sheet S2is used. The thicker the sheet S, the more markedly the effect of the present exemplary embodiment is exhibited. However, the effect that the conveyance direction of the sheet S is unlikely to change can be obtained even when the thin sheet S is used.

As illustrated inFIG.9, the groove30is disposed upstream of the line of the arrow F (the straight line passing through the rotational centers of the sheet discharge roller23and the sheet discharge driven roller24) in the sheet S conveyance direction. Therefore, the protrusion amounts of the roller holder31and the sheet discharge frame29can be reduced. This enables reducing the possibility that the trailing edge of the discharged sheet S is caught on the sheet discharge frame29.

FIGS.10A and10Billustrate a comparative example and the present exemplary embodiment, respectively.FIG.10Aillustrates the configuration of the comparative example as a modification of the present exemplary embodiment.FIG.10Billustrates the configuration of the present exemplary embodiment. The present exemplary embodiment is configured to provide a smaller sliding resistance when the roller holder31moves than the comparative example. The mechanism of the roller holder31will be described below.

FIG.10Aillustrates a configuration in which the moving direction D′ of the first projection25band the moving direction U′ of the second projection25aare made parallel to the nip pressure direction F to linearly move the roller holder31in the nip pressure direction F. To reduce the moving region toward the downstream side of the roller holder31in the horizontal direction H, the positions of the first projection25band the second projection25aare disposed upstream (arrow N′) of the dotted line of the nip pressure direction F in the conveyance direction.

The roller holder31is upwardly pressed by the force of the pressing spring26, and the first projection25bcomes into contact with the groove30′ at a point25b′. Since the roller holder31receives the resistance of the nip pressure in the F′ direction, a moment M′=F′*L′ arises around the point25b′, where L′ denotes the distance between the point25b′ and the dotted line of the nip pressure direction F. As a result, the second projection25acomes into contact with the groove30′ at a point25a′ and receives the moment M′.

Since a direction Z1of the force by the moment M′ at the point25a′ and a direction Z2perpendicular to the surface receiving the force at the point25a′ form an angle ε1, the upstream boss25agenerates a force to break into the groove30′. Therefore, when the roller holder31moves downward, the sliding friction at the point25a′ increases, making it hard for the roller holder31to move downward.

On the other hand, in the configuration illustrated inFIG.10Bin which the arrow D is inclined relative to the arrow U, an angle ε2 formed by the direction Z1and a direction Z3perpendicular to the surface receiving the force at the point25a′ becomes smaller than the angle ε1. As a result, the sliding friction at the point25a′ relatively decreases and the roller holder31becomes likely to move downward.

According to a second exemplary embodiment, the configuration characterizing the present disclosure is applied to the sheet feeding unit5a. The present exemplary embodiment will be described below with reference toFIGS.11and16A and16B.FIG.11is a cross-sectional view illustrating a periphery of the sheet feeding unit5a. A pick roller103comes into contact with the top sheet S and rotates to feed the sheet S to the nip portion formed by a feed roller101and a separation roller102. The separation roller102incorporates a torque limiter (not illustrated). The feed roller101and the separation roller102separate and feed the sheets S one by one.

Referring toFIG.11, a conveyance path120for conveying the sheet S fed from the sheet feeding unit6binFIG.1is provided to the right of the sheet feeding unit5a.FIG.12is a perspective view illustrating the sheet feeding cassette6a.FIGS.13A to13Dillustrate the separation roller unit100.FIG.13Ais a plan view,FIG.13Bis a right-side view,FIG.13Cis a rear view, andFIG.13Dis a cross-sectional view taken along the E-E line inFIG.13C.

The separation roller unit100includes a separation roller102, a separation roller holder104, a separation guide105, and a pressure spring107. The separation roller102is held by the separation roller holder104that is held by the separation guide105. When the separation roller holder104is pressed toward the feed roller101by the pressure spring107, the nip pressure between the feed roller101and the separation roller102is applied.

FIGS.14A and14Bare perspective views illustrating the separation roller holder104holding the separation roller102.FIGS.15A and15Bare perspective views illustrating the separation guide105, andFIG.15Cis a side view illustrating the separation guide105. The separation roller holder104is provided with two pairs of bosses, a pair of upstream bosses104aand a pair of downstream bosses104bin the sheet width direction. Both side surfaces of the separation guide105in the sheet width direction are provided with an oblong hole106including an upstream oblong hole106aand a downstream oblong hole106b. When the upstream boss104afits into the upstream oblong hole106aand the downstream boss104bfits into the downstream oblong hole106b, the separation roller holder104is held by the separation guide105.

FIGS.16A to16Billustrate the separation roller unit100.FIG.16Aillustrates the separation roller unit100when viewed in the same direction as that inFIG.13C.FIG.16Bis a cross-sectional view taken along the G-G line inFIG.16A, illustrating a state where the separation roller102and the separation roller holder104are in contact with the feed roller101and a state where the separation roller102is separated from the feed roller101.

The moving direction of the downstream boss104btoward the feed roller101is indicated by the arrow D, and the moving direction of the upstream boss104atoward the feed roller101is indicated by the arrow U. According to the present exemplary embodiment, to achieve stable sheet feeding as in the first exemplary embodiment, the arrow D is inclined relative to the arrow U by an angle γ upstream in the conveyance direction N to bring the moving direction K of the separation roller102and the nip pressure direction F close to each other.

When viewed in the rotational axis direction of the separation roller102like the first exemplary embodiment, the angle formed by the arrow D relative to the direction of the straight line passing through the rotational centers of the separation roller102and the feed roller101is smaller than the angle formed by the arrow U relative to the direction of the straight line.

A guide path formed by the groove106, the downstream boss104b, and the upstream boss104ais disposed upstream of the line of the arrow F in the sheet S conveyance direction. The use of this configuration enables reducing the downstream side of the separation roller102and the separation roller holder104in the horizontal direction H, making it possible to provide the conveyance path120as illustrated inFIG.11.

The sheet conveyance apparatus of the present disclosure can effectively use the space around the rollers while restricting a large change of the sheet conveyance direction.

This application claims the benefit of Japanese Patent Application No. 2022-126812, filed Aug. 9, 2022, which is hereby incorporated by reference herein in its entirety.