JP2001106345A - Sheet feeding device and image forming device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely separate various kinds of sheets having rigidity. SOLUTION: This sheet feeding device 11 has a sheet loading means to load sheets 36, a sheet feeding means 35 capable of contacting with sheets loaded on the means 36 and separating therefrom while feeding out them from the means 36, and a separation slant surface 41 receiving a tip of sheets fed out of the means 36 so as to separate them one by one. The means 36 has a sheet loading part 21 capable of supporting sheets in a bent condition with the pressing force against the sheets of the sheet feeding means 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sheet (hereinafter referred to as a sheet).
A sheet feeding device for feeding one sheet at a time, and a copying machine including the sheet feeding device and forming an image on a recording medium sent from the sheet feeding device.
The present invention relates to an image forming apparatus such as a printer, a facsimile, and a composite device thereof.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No.
The sheet feeder used in the printer, which is an image forming apparatus described in Japanese Patent Laid-Open Publication No. H10 (1995), makes the feed roller abut on the uppermost recording medium among the stacked recording media,
The recording medium is supplied by the rotation of the feed roller. However, the recording medium is not always supplied one by one, but may be supplied in a plurality of layers.
For this reason, the sheet feeding device causes the leading end of the recording medium sent out by the feeding roller to abut on the separation slope, and separates the topmost recording medium from the recording medium below by utilizing the bending of the recording medium. Only the uppermost recording medium is supplied to a predetermined position (for example, a printing position).

Further, a feeding roller (referred to as a driving roller in this publication) of a sheet feeding device described in Japanese Patent Application Laid-Open No. Hei 8-259013 is rotated by a gear train to feed a sheet. It has become.

The sheet feeding apparatus shown in FIG. 13 in which these are combined has a shaft support gear train 30 formed by a drive shaft gear 2, idler gears 3, 4 and a feeding roller gear 5. The shaft support gear train 30 is supported by a swing frame 34 provided to be swingable in the direction of arrow A on a rotation center shaft 130 which is the center of the drive shaft gear 2. Feeding roller gear 5
Is integrated with the large-diameter feeding roller 31.

[0005] The feed roller 31 is provided with a stacked recording medium P.
Are placed on the upper surface of the uppermost recording medium P, and the uppermost recording medium P is fed in the direction shown by the arrow B.

For example, when the drive shaft gear 2 is rotated in a counterclockwise direction by a motor (not shown), a counterclockwise rotation torque is applied to the swing frame 34 which freely rotates around the rotation shaft 130, and the swing The frame 34 approaches the recording medium, and presses the feed roller 31 against the uppermost recording medium to restrict swinging. At this time, the swing frame 34
The rotation is restricted in a state where the feed roller 31 is pressed against the uppermost recording medium. When the rotation of the swing frame 34 is restricted, the feeding roller 31 starts rotating. At this time, the feeding roller 31 may be rotated from a completely stopped state, or may be further rotated from a slightly rotated state.

The uppermost recording medium P is pressed against the separation slope 33 by the rotation of the feed roller 31. The uppermost recording medium P bends in a loop and separates from the second recording medium. When the uppermost recording medium is formed into a loop, the feed roller 31 forms a loop against the rigidity of the recording medium. Theoretically, there is no limitation on the rotational torque of the supporting gear train 30, and the vertical force due to the rotational torque of the swing frame of the paper feed roller 31 is affected by the buckling resistance of the separated recording medium. After it loops, it continues to increase until it buckles.

For this reason, a reaction force in the reverse rotation direction is applied to the feeding roller 31, and the rotation is slowed. Then, the rotation torque of the oscillating frame increases by an amount corresponding to the slow rotation, and the feeding roller 31 is strongly pressed by the recording medium, and reliably sends only the uppermost recording medium without slipping on the recording medium. . When the recording medium is fed, the rotation of the feed roller 31 increases. Oscillating frame 3 due to faster rotation
4 is reduced.

As described above, the sheet feeding device shown in FIG.
The recording medium is pressed against the separation slope 33 by the balance with the rotation torque of No. 4 to reliably separate and feed the recording medium one by one.

The sheet includes plain paper, a thin resin sheet which is a substitute for plain paper, a postcard, cardboard,
There are sealed letters and plastic thin plates.

[0011]

However, in the conventional sheet feeding apparatus shown in FIG. 13, the portion related to Japanese Patent Application Laid-Open No. Hei 2-132018 (U.S. Pat. The separation performance of the recording medium is limited by the coefficient of friction and the like, and the types of applicable recording media are limited.

For example, when a recording medium having a small thickness is used at a gradient of a separation slope set so that a good feeding operation can be performed on a recording medium having a large thickness, the recording medium has no rigidity. The frictional force of the recording medium is extremely small, and a slippage occurs between the separation slope and the recording medium, so that there is a problem that a plurality of recording media are simultaneously fed while overlapping (multifeed).

For this reason, a recording medium having a small rigidity is difficult to be separated, and it is necessary to provide a sufficient deflection by increasing the slope of the separation slope. However, if a recording medium having high rigidity such as a postcard or an envelope is abutted against a separation slope having a large gradient, a buckling resistance acting on the recording medium when the recording medium is separated is large. There has been a problem that the vertical force of the feed roller (for example, see Japanese Patent Application Laid-Open No. H8-259013) continues to increase, and the rotation torque about the rotation center shaft 130 becomes unnecessarily large.

As described above, various kinds of rigid recording media cannot be reliably separated, causing misfeeds and jamming of the recording media.

Therefore, the present invention automatically adjusts the contact angle of the sheet to the separation slope to an optimum angle according to the rigidity of the sheet so that sheets of various rigidities can be reliably separated. It is an object of the present invention to provide a sheet feeding apparatus capable of eliminating the causes of double feeding, misfeeding, jamming, and the like of sheets, and an image forming apparatus including the sheet feeding apparatus.

[0016]

According to the present invention, there is provided a sheet feeding apparatus comprising: a sheet stacking unit on which sheets are stacked; and a sheet stackable unit capable of moving toward and away from the sheets stacked on the sheet stacking unit. Means for feeding the sheet, and a separation slope for receiving the leading edge of the sheet sent from the sheet stacking means by the sheet feeding means and separating the sheets one by one, wherein the sheet stacking means includes There is a sheet stacking section capable of supporting the sheet in a bent state by a pressing force of the supply means against the sheet.

The sheet stacking portion of the sheet feeding device of the present invention is formed to be bendable by a pressing force of the sheet feeding means against the sheet, and is urged toward the sheet feeding means by an urging means.

The sheet stacking section of the sheet feeding apparatus according to the present invention includes an upstream tilting member whose downstream end tilts up and down around the upstream end, and an upstream tilting member whose vertical end moves vertically around the downstream end. A downstream tilting member that tilts, and a connecting portion that connects the downstream end of the upstream tilting member and the upstream end of the downstream tilting member so that they can approach and separate from each other and can rotate. At least one of the downstream-side inclined members is urged by the urging means toward the sheet supply means.

The sheet stacking section of the sheet feeding apparatus according to the present invention includes an upstream tilting member whose downstream end tilts up and down around the upstream end, and an upstream tilting member whose vertical end moves vertically around the downstream end. A downstream-side inclined member that tilts, wherein the upstream-side inclined member and the downstream-side inclined member are each urged toward the sheet supply means by urging means.

In the sheet stacking section of the sheet feeding apparatus of the present invention, an upstream end side from an intermediate portion of the sheet stacking surface is formed so as to be displaceable downward by a pressing force of the sheet feeding section against the sheet, and is biased by an urging section. The apparatus includes a descending displacement member urged toward the sheet supply means and a sheet leading end support for supporting a downstream end portion of the sheet.

[0021] The sheet leading end support of the sheet feeding apparatus of the present invention has a loading surface for supporting the leading end of the sheet and a slope for bending the sheet.

The separation slope of the sheet feeding device according to the present invention is disposed near a downstream end of a sheet stacking section of the sheet stacking means.

The angle formed between the sheet stacked on the sheet stacking means when the sheet feeding device of the present invention is not fed and the separation slope is set to be substantially a right angle.

The sheet feeding device of the present invention has a sheet stacking section having a sheet stacking section on which sheets are stacked, and a sheet stacking section capable of coming into contact with and separating the sheets stacked on the sheet stacking section. And a separation slope for receiving the leading edge of the sheet sent from the sheet stacking unit by the sheet feeding unit and separating the sheets one by one, wherein the sheet stacking unit includes A first sheet stacking surface supporting the leading end, and a concave second sheet stacking surface for dropping an intermediate portion of the sheet supported by the first sheet stacking surface by a pressing force of the sheet supply means against the sheet The first separation slope is provided downstream of the first sheet stacking surface, and the second separation slope is provided downstream of the second sheet stacking surface. The surface is provided, towards the second separation slope is inclined to the downstream side of the first separation slope.

The downstream end of the sheet stacking section of the sheet feeding apparatus of the present invention is set lower than the upstream end.

The sheet stacking section of the sheet feeding apparatus according to the present invention is inclined from about 45 degrees to about 90 degrees with respect to the installation surface.

[0027] The sheet stacking means of the sheet feeding apparatus of the present invention has a frame, and the sheet stacking section is provided in the frame.

The sheet stacking means of the sheet feeding apparatus according to the present invention has a frame provided with the sheet stacking section, wherein the first separation slope is a wall at a downstream end of the frame. A second separation slope is formed at an intermediate portion of the frame.

The angle formed by the straight sheet stacked on the first sheet stacking surface of the sheet feeding device of the present invention and the first separation slope is set to be substantially a right angle.

The sheet supply means of the sheet supply device of the present invention includes a swing member having an upstream end side as a swing center, and a swing member provided at a swing end of the swing member to contact the sheet and to feed the sheet. And a sheet supply rotating body rotatable in the feeding direction.

The sheet feeding apparatus according to the present invention has a rotation transmitting means for transmitting rotation to the sheet supply rotating body through a swing center of the swinging member, and a rotational force transmitted to the sheet supply rotating body. Thereby, the torque around the swing center is applied to the swing member so that the sheet supply rotating body is urged against the stacked sheets.

[0032] The sheet feeding device of the present invention comprises a drive gear centered on the swing center of the swing member, and a gear arranged on the swing member to transmit the rotation of the drive gear to the sheet feed rotating body. With columns.

[0033] The image forming apparatus of the present invention may include any one of the above.
One sheet supply device, and image forming means for forming an image on the sheet supplied by the sheet supply device,
It has.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 5, and a second embodiment will be described with reference to FIG.
The third embodiment will be described with reference to FIGS. 8 and 9 based on FIG. 7, and the fourth embodiment will be described with reference to FIGS. 10 to 12.

The same parts as those of the conventional sheet feeding apparatus shown in FIG. 13 are denoted by the same reference numerals.

Numerical values shown in the description of the present embodiment are numerical values shown for reference to facilitate understanding.
It is not limited to the numerical value.

(First Embodiment) The sheet feeding apparatus 11 of the first embodiment shown in FIGS. 1 to 4 is a recording apparatus 1 which is an image forming apparatus shown in FIGS. It is provided in.

FIGS. 1 and 2 are side views of the recording apparatus 1 and are partially shown in section.

The recording apparatus 1 includes a sheet feeding unit 210, a carriage unit 220, and a sheet discharging unit 230 in addition to the sheet feeding unit 11.
Etc. are provided.

In FIG. 1, the sheet feeding device 11 includes a frame 61 of the sheet feeding device 11, a sheet stacking section 21, a separation slope 41 serving as a sheet separating means, a shaft support gear train 30, a movable side guide 51, and the like. Have been. The movable side guide 51 is located on one side (rear side in the drawing), and has a fixed guide (not shown) on the facing surface so that both sides of the recording medium P are aligned.

The sheet stacking section 21 is mounted on the right side of the recording apparatus 1.

The recording medium P set in the sheet supply device 11 is discharged substantially horizontally after printing.

As shown in FIG. 1, the recording medium P and the feed roller 31, which is a sheet supply rotating body, are normally in a standby state.
Separated from each other.

The swing frame 34, which is a swing member that swings around the rotation center shaft 130, the feeding roller 31, and the drive shaft gear 2 that is a drive gear that rotates around the rotation center shaft 130. And the idler gears 3 and 4 for transmitting the rotation of the drive shaft gear 2 to the feed roller 31, and the shaft support gear train 30 which is a gear train formed by the feed roller gear 5 and the like,
The sheet supply means 35 is constituted.

As shown in FIG. 2, the recording medium P is rotated by a paper feed motor (not shown) started by a feed roller 31 attached to the shaft support gear train 30 in accordance with a recording medium feed command. Sheet loading unit 21
Is picked up and set on the separation slope 4
1 and are separated one by one by a separation slope 41. The separated recording medium P is sent to the paper feeding unit 210 (see FIG. 2).

The feeding roller 31 feeds the recording medium P to the sheet feeding section 2.
It rotates until it is fed to 10, and when it is fed, it enters a standby state.

At the same time, a motor (not shown)
The drive to the feeding roller 31 is cut off, and the sheet feeding device 11 is turned off.
Is in an initial state (see FIG. 1).

In order to make the feed roller 31 stand by, for example, the drive shaft gear 2 is rotated clockwise at a predetermined timing, and the drive shaft gear 2 is rotated clockwise in the shaft support gear train 30 which freely rotates around the rotation center shaft 130. Then, the feeding roller 31 is separated from the recording medium P by applying the rotation torque described above, and a standby state is set. Alternatively, an elastic body such as a spring is provided so that the feeding roller 31 is separated from the recording medium P at the same time when the transmission about the rotation center shaft 130 is completed, and the feeding roller 31 is provided by the elastic body.
May be put in a standby state.

The paper feeding section 210 includes a transport roller 211, a pinch roller 212, a PE sensor lever 214, a PE sensor 215, a platen 216, and the like.

The recording medium P sent to the paper feeding section 210 is guided by a platen 216 and is sent between a pair of conveying rollers 211 and a pinch roller 212. PE sensor lever 2 provided in front of these roller pairs 211 and 212
14, the leading end of the recording medium P is detected, and the printing position on the recording medium P is determined.

The recording medium P sent between the pair of rollers 211 and 212 advances along the platen 216 by the pair of rollers 211 and 212 rotated by a paper feed motor (not shown), and a predetermined image is formed by the recording head 221. Recording based on the information is performed.

The recording head 221 is an ink-jet recording head which is formed integrally with the ink tank and is easily replaceable. The recording head 221 includes an electric exchanger, and performs recording by discharging re-ink from the discharge port using a pressure change generated by applied heat energy.

The carriage section 220 includes a recording head 221.
, A guide shaft 223 that guides reciprocal scanning in a direction perpendicular to the conveyance direction of the recording medium P, a timing belt (not shown) for transmitting drive of a carriage motor (not shown) to the carriage 222, and a timing belt. An idler pulley (not shown) to be provided, a flexible substrate (not shown) for transmitting a head drive signal from the electric substrate to the recording head, and the like are provided.

The recording head 221 and the carriage 222
By performing the scanning integrally, an image can be formed on the recording medium P conveyed on the platen 216.

The paper discharge section 230 includes a paper discharge roller 231, a transmission roller 232 for transmitting the drive of the transport roller 211 to the paper discharge roller 231, a spur 233 for assisting paper discharge, and a paper discharge tray (not shown).

The recording medium P on which an image has been recorded by the recording head 221 is discharged to a discharge tray by a discharge roller 231 and a spur 233.

FIGS. 3 to 5 are side views of the sheet feeding device 11 and are partially shown in section.

The sheet feeding device 11 is unitized by attaching each component to a frame 61.

The sheet stacking section 21 includes a first pressure plate 22 that is an upstream inclined member and a second pressure plate 23 that is a downstream inclined member.

As shown in FIG. 3, the sheet loading surface 22 ′ of the first pressure plate 22 of the sheet loading unit 21 and the second pressure plate 23
The sheet stacking surfaces 22 ′ and 23 ′ as the sheet stacking unit 21 are substantially aligned with the sheet stacking surface 23 ′.
And the separation slope 41 for receiving the downstream end of the recording medium is set at about 90 degrees to about 100 degrees.

When the sheet stacking surfaces 22 ′ and 23 ′ as the sheet stacking section 21 are substantially straight, the downstream end is set lower than the upstream end and the inclination angle ε with respect to the installation surface of the recording apparatus 1 is set. Is set at about 30 degrees to about 90 degrees.

The first pressure plate 22 is connected to the frame 61 by first shafts 24 on both sides on the upstream end, and can be tilted up and down about the first shaft 24. Further, a pressure plate spring 62 as an urging means is disposed between the lower surface of the first pressure plate 22 and the frame 61 and at a position substantially opposed to the feed roller 31. The pressure plate spring 62 may be provided between the lower surface of the second pressure plate 23 described below and the frame 61.

The first pressure plate 22 is urged by the pressure plate spring 62 toward the shaft support gear train 30. First pressure plate 2
2 is a cam 25 provided at the inclined end of the first pressure plate 22.
By contacting with the regulating holes 150 formed in the frame body 61, the tilting toward the shaft support gear train 30 side is regulated.

The second pressure plate 23 is connected to the frame 61 by second shafts 26 on both sides at the downstream end, and can be tilted up and down around the shaft 26. The second pressure plate 23 is
In the vicinity of the rotation trajectory of the feeding roller 31, the first pressure plate 22 is connected to the first pressure plate 22 by the elongated holes 23d provided on both sides of the upstream end and the shafts 22f provided on both sides of the downstream end of the first pressure plate 22. I have. For this reason, the sheet stacking section 21 is bendable.

The range of the bending angle θ (see FIG. 5) of the sheet stacking section 21 is determined by the length of the long hole 23d. The long hole 23d and the shaft 22f constitute a connecting portion 37.

In the above configuration, the first and second pressure plates 22 and 23 (sheet stacking portion 21), the long hole 23d and the shaft 22f (connection portion 37), the pressure plate spring 62 (biasing means), the frame 61 The movable side guide 51, the cam 25, the restriction hole 150, and the like constitute the sheet stacking means 36.

Next, the operation will be described.

FIG. 3 to FIG. 5 are views showing the state of separation of recording media having different rigidities.

Each of the recording media shown in FIGS.
1, P2, and P3, and P3>P2> P in descending order of rigidity
Let it be 1.

In FIG. 3, when the recording medium P1 is set, the drive shaft gear 2 of the shaft support gear train 30 in the initial state is rotated counterclockwise by a paper feed motor (not shown) started by a recording medium feeding command. , A counterclockwise rotation torque is applied to the shaft support gear train 30, the swing frame 34 swings toward the recording medium P, and the feed roller 31 attached to the shaft support gear train 30 also moves to the recording medium P1. Move towards. The feed roller 31 contacts the recording medium. Then, the rotational force of the drive shaft gear 2 is transmitted to the feed roller 31 via the idler gears 3 and 4 and the feed roller gear 5. Thus, the uppermost recording medium P1 is pressed against the separation slope 41.

Since the turning force of the shaft gear train 30 is not limited, the vertical force of the feeding roller 31 pressing the recording medium is limited by the buckling resistance of the uppermost recording medium P1 separated from the lower recording medium. Defined by Therefore, this normal force is
The recording medium P1 continues to increase until it buckles against the uppermost separation slope 41. The feed roller 31 continues to rotate even if the uppermost recording medium P1 buckles. For this reason, the uppermost recording medium P1 is separated from the lower-order recording medium and is conveyed to the paper feeding unit 210 (see FIG. 2). The angle between the recording medium P1 and the separation slope 41 when the recording medium P1 buckles is α
And

When the uppermost recording medium P1 is fed, the normal force does not increase any more. The vertical force at this time is smaller than the urging force of the pressure plate spring 62. Therefore, the first
The pressure plate 22 and the second pressure plate 23 are not bent as shown in FIG. 3 and are held in a straight line.

Next, the action on the recording medium P2 having different rigidity is shown in FIG.

The buckling resistance of the recording media P2 having different rigidities is as follows.
Since the recording medium P1 is larger than the recording medium P1, the buckling hardly occurs at the angle α of the separation slope 41. Therefore, the vertical force of the feed roller 31 also increases. And, the shaft support gear train 30 is
The sheet stacking portion 21 is bent as it rotates around zero. That is, the first pressure plate 22 and the second pressure plate 23
Is bent against the pressure plate spring 62 as shown in FIG.

As a result, the sheet stacking portion 21 continues to bend until the contact angle β at which the recording medium P2 is bent with respect to the separation slope 41. When the contact angle to the separation slope 41 becomes β (β <α), the uppermost recording medium P2 is separated from the lower recording medium and conveyed to the paper feeding unit 210 (see FIG. 2).

FIG. 5 shows a recording medium P having a higher rigidity.
3 (P3>P2> P1).

Similarly, the sheet stacking section 21 continues to bend until it buckles due to the difference in rigidity of the recording medium,
Recording medium P3 at the contact angle γ (γ <β <α)
Is separated from the lower recording medium.

As described above, as the buckling resistance increases,
The sheet stacking portion 21 continues to bend, and the contact angle with the separation slope 41 decreases. For this reason, the elasticity, the bending angle θ, and the like of the pressure plate spring 62 are set so as to obtain stable separation performance, so that double feeding does not occur.

Therefore, by changing the contact angle of the recording medium to the separation slope 41 so that the recording medium can be reliably separated in accordance with the rigidity of the recording medium, the rigidity differs between a thin recording medium and a thick recording medium. It is possible to prevent occurrence of feeding failure such as double feeding, misfeed, and jam of the recording medium.

(Second Embodiment) A sheet feeder 11A according to a second embodiment of the present invention will be described with reference to FIGS. Note that this sheet supply device 11A also has
It can be incorporated in the recording device 1 shown in FIGS.

FIGS. 6 and 7 are side views of the sheet feeding device 11A, and are partially shown in section.

In the sheet feeding device 11A, the first
The same parts as those of the sheet feeding apparatus 11 according to the embodiment are denoted by the same reference numerals, and
In order to correspond to the sheet feeding device 11 of the embodiment,
1 to 5 are indicated by adding a suffix a.

The sheet feeding device 11A is unitized by attaching various components to a frame 61a.

The sheet stacking section 21a includes a first pressure plate 22a which is an upstream inclined member and a second pressure plate 23a which is a downstream inclined member.

As shown in FIG. 6, when the sheet loading surface 22'a of the first pressure plate 22a of the sheet loading portion 21a and the sheet loading surface 23'a of the second pressure plate 23a are substantially in a straight line, Sheet loading surface 2 as loading portion 21a
The angle δ between 2′a, 23′a and the separation slope 41a that receives the downstream end of the recording medium is set to about 90 degrees to 100 degrees.

When the sheet stacking surfaces 22'a and 23'a as the sheet stacking section 21a are substantially in a straight line, the downstream end is set lower than the upstream end, and the inclination with respect to the installation surface of the recording apparatus 1 is set. The angle ε is about 30 degrees to about 9
It is set to 0 degrees.

The first pressure plate 22a is provided at both ends of the upstream end.
The shaft 24a is connected to the frame 61a, and can be tilted up and down about the first shaft 24a. Also, between the lower surface of the first pressure plate 22a and the frame 61a,
In addition, a first pressure plate spring 62a, which is an urging means, is provided at a position substantially opposed to the feeding roller 31.

The first pressure plate 22a is urged toward the feed roller 31 by the first pressure plate spring 62a. The first pressure plate 22a is provided with a force hole 25a provided at the tilting end of the first pressure plate 22a, and a restriction hole 15 formed in the frame 61a.
The rotation to the feed roller 31 side is restricted by abutting on Oa.

The second pressure plate 23a is connected to the frame 61a by second shafts 26a on both sides at the downstream end, and can be tilted up and down about the shaft 26a. Further, a second pressure plate spring 63 serving as an urging means is disposed between the lower surface of the second pressure plate 22a and the frame 61a and at a position substantially opposed to the feeding roller 31.

The second pressure plate 23a is urged toward the feed roller 31 by the second pressure plate spring 63a. The rotation of the second pressure plate 23a toward the feed roller 31 is restricted by the shaft 27 provided at an intermediate portion of the second pressure plate 23a abutting on the restriction hole 160 formed in the frame 61a. Have been.

With the above configuration, the range of the bending angle θa (see FIG. 7) of the sheet stacking portion 21a is determined by the contact between the shaft 27 and the restriction hole 160.

In the above configuration, the first pressure plate 22a and the second pressure plate 23a (the sheet stacking portion 21a), the pressure plate springs 62a and 63 (biasing means), the frame 61a, the movable side guide 51, the cam 25a, and the restriction. The hole 150a, the shaft 27, the restriction hole 160, and the like constitute a sheet stacking unit 36a.

Next, the operation will be described.

As in the first embodiment, FIGS. 6 and 7 show how recording media having different rigidities are separated from each other.

The recording media shown in FIG. 6 and FIG.
1, P3, and P3> P1 in descending order of rigidity.

From FIG. 6, the angle of the separation slope at which the recording medium P1 buckles is αa.

Next, the state of action on recording media P3 having different stiffness is shown in FIG.

Since the buckling resistance of the recording media P3 having different stiffness is larger than that of the recording medium P1, it is difficult to bend at the angle αa of the separation slope, so that the vertical force of the feeding roller 31 increases. The sheet stacking portion 21a is bent as the shaft support gear train 30 rotates around the rotation center shaft 130.

As a result, the recording medium P3 is separated from the separation slope 41a.
Sheet stacking portion 21a up to the contact angle γa buckling against
Keeps bending. The contact angle to the separation slope 41a is γa
When (γa <αa), the recording medium is separated.

As the buckling resistance increases as shown in FIG.
The sheet stacking portion 21a continues to bend, and the contact angle to the separation slope 41a decreases. Therefore, the elasticity and bending angle θa of the first pressure plate spring 62a and the second pressure plate spring 63
Are set so that stable separation performance can be obtained, so that double feeding does not occur.

Therefore, by changing the contact angle of the recording medium to the separation slope 41a so that the recording medium can be surely separated in accordance with the rigidity of the recording medium, recording can be performed due to the difference in rigidity between a thin recording medium and a thick recording medium. It is possible to prevent the occurrence of feeding failure such as double feeding, misfeeding, and jam of the medium.

(Third Embodiment) A sheet feeding apparatus 11B according to a third embodiment of the present invention will be described with reference to FIGS. Note that this sheet supply device 11B also has
It can be incorporated in the recording device 1 shown in FIGS.

FIGS. 8 and 9 are side views of the sheet feeding device 11B, which are partially shown in section.

In this sheet feeding device 11B, the first
The same parts as those of the sheet feeding apparatus 11 according to the embodiment are denoted by the same reference numerals, and
In order to correspond to the sheet feeding device 11 of the embodiment,
1 to 5 are indicated with a suffix b.

The sheet feeding device 11B is unitized by attaching each component to a frame 61b.

The sheet stacking portion 21b includes a pressure plate 22b which is a descending displacement member for supporting at least the intermediate portion between the intermediate portion and the upstream end portion of the recording medium, and a convex portion which is a sheet leading end support member for bending the recording medium. 23b.

As shown in FIG. 8, when the sheet loading surface 22'b of the pressure plate 22b of the sheet loading portion 21b and the sheet loading surface 23'b of the projection 23b are substantially in a straight line, the sheet loading portion 21b Sheet loading surface 22'b, 23 '
The angle δ between b and the separation slope 41b that receives the downstream end of the recording medium is set at about 90 degrees to about 100 degrees.

When the sheet stacking surfaces 22b 'and 23'b as the sheet stacking section 21b are substantially aligned, the downstream end is set lower than the upstream end, and the inclination angle with respect to the installation surface of the recording apparatus 1 is set. ε is from about 30 degrees to about 9
It is set to 0 degrees.

The pressure plate 22b is connected to the first shaft 24 on both sides of the upstream end.
b, the first shaft 24b is connected to the frame 61b.
Can be tilted up and down around the center. In addition, between the lower surface of the pressure plate 22b and the frame body 61b and at a position substantially opposed to the feed roller 31, a pressure plate spring 6 serving as an urging means is provided.
2b is provided.

The pressure plate 22b is urged toward the feed roller 31 by the pressure plate spring 62b. The pressure plate 22b
The force 25b provided at the tilting end of the pressure plate 22b is
By contacting the regulating holes 150b formed in the feeding roller 31b, the tilting toward the feeding roller 31 is restricted.

As shown in FIGS. 8 and 9, the projection 23b protrudes from the frame 61b so as to contact the lowermost recording medium loaded. In addition, the convex portion 23b is provided with the first corner portion 28.
And a second corner 29 near the rotation orbit of the feed roller 31. First corner 28 and second corner 2
The slope 23 ″ b between the first and second sheets 9 is a slope for bending the sheet.

With the above arrangement, the bending angle θb of the recording medium
The range of (see FIG. 9) includes the first corner 28 and the second corner 2.
Nine and nine.

In the above configuration, the pressure plate 22b and the convex portion 23b (sheet stacking portion 21b), the pressure plate spring 62b (biasing means), the frame 61b, the movable side guide 51, and the cam 25
b and the restriction hole 150b constitute a sheet stacking means 36b.

Next, the operation will be described.

FIG. 8 and FIG. 9 are views showing the state of separation of recording media having different rigidities by the sheet feeding device 11B.

The recording media shown in FIG. 8 and FIG.
1, P3, and P3> P1 in descending order of rigidity.

From FIG. 8, the angle of the separation slope at which the recording medium P1 is bent is αb.

Next, the action on recording media P3 having different stiffness is shown in FIG.

Since the buckling resistance of the recording media P3 having different stiffness is larger than that of the recording medium P1, the buckling hardly occurs at the contact angle αb with the separation slope 41b, and the vertical force of the feeding roller 31 pressing the recording medium also increases. . And the shaft support gear train 30
Is rotated around the rotation center axis 130, the recording medium bends about the first corner 28 as a fulcrum.

As a result, the recording medium P3 is separated from the separation slope 41b.
The recording medium P3 continues to bend until the contact angle γb is bent. When the contact angle to the separation slope 41b is γb (γb <
At αb), the recording medium is separated.

As the buckling resistance increases as shown in FIG.
The recording medium continues to bend, and the contact angle to the separation slope 41b decreases. For this reason, the pressure plate spring 62b, the bending angle θb, and the like are set so as to obtain stable separation performance, so that double feeding does not occur.

Therefore, by changing the contact angle of the recording medium to the separation slope 41b so that the recording medium can be reliably separated in accordance with the rigidity of the recording medium, the recording medium due to the difference in rigidity between a thin recording medium and a thick recording medium can be obtained. It is possible to prevent occurrence of feeding failure such as double feeding, misfeed, and jam.

(Fourth Embodiment) FIGS. 10 to 1 show a sheet feeding apparatus 11C according to a fourth embodiment of the present invention.
2 will be described. Note that this sheet feeding device 11
C can also be incorporated in the recording device 1 shown in FIGS.

FIGS. 10 to 12 show the sheet feeding device 11C.
3 is a side view of FIG.

In the sheet feeding device 11C, the first
The same parts as those of the sheet feeding apparatus 11 according to the embodiment are denoted by the same reference numerals, and
In order to correspond to the sheet feeding device 11 of the embodiment,
1 to 5 are indicated with a suffix c.

The sheet feeding device 11C is unitized by attaching components to a frame 61c.

The sheet stacking portion 21c is formed integrally with the frame 61c, and has a first sheet stacking surface 240a,
240b (see FIG. 10), and a second sheet stacking surface 250 (see FIG. 11), which is a concave portion for bending the recording medium, is provided near the rotation orbit of the feed roller 31. The first sheet stacking surfaces 240a and 240b are formed in a straight line. The first sheet stacking surfaces 240a and 240b and the second sheet stacking surface 250 are formed substantially parallel to each other.

Further, the first sheet stacking surfaces 240a, 240
0b and the first separation slope 42 that receives the downstream end of the recording medium is set at about 90 degrees to about 100 degrees.

Further, the first sheet stacking surfaces 240a, 240a
40b, the downstream end side is set lower than the upstream end side, and the inclination angle ε with respect to the installation surface of the recording apparatus 1 is set to about 30 degrees to about 90 degrees.

The first sheet stacking surface 240 on the downstream side and the second
The sheet stacking surface 250 of FIG.
1).

The first sheet stacking surface 240 on the downstream side and the second
A corner 28c for receiving the lowest-order recording medium when the recording medium is pressed against the second sheet stacking surface 250 is formed between the separation slope 43 (see FIG. 12).

With the above configuration, the bending angle θc of the recording medium
The range of (see FIG. 12) is determined by the corner 28c and the second sheet stacking surface 250.

In the above configuration, the frame 61c, the sheet stacking section 21c, the first separation slope 42, the second separation slope 43, and the like constitute a sheet stacking means 36c.

Next, the operation will be described.

FIGS. 10 and 12 are views showing the state of separation of recording media having different rigidities.

The recording media shown in FIGS. 10 and 12 are denoted by P1 and P3, respectively, and P3> P1 in descending order of rigidity.

As shown in FIG. 10, the recording medium P1 having low rigidity is set on the second sheet stacking surface 250. As shown in FIG. 11, a recording medium P3 having a large rigidity is set on the first sheet stacking surface 240. Recording medium P in FIG.
The angle λ of the second separation slope 43 where 1 is bent in a loop shape is set so as to obtain stable separation performance.

As shown in FIG. 10, the angle δ between the first sheet stacking surfaces 240a and 240b and the first separation slope 42 for receiving the downstream end of the recording medium is about 90 degrees to about 100 degrees. Is set.

In the sheet stacking section 21c, the downstream end side is set lower than the upstream end side, and the inclination angle ε with respect to the installation surface of the recording apparatus 1 is set at about 30 degrees to about 90 degrees.

Next, the state of action on the recording medium P3 having high rigidity is shown in FIG.

Since the buckling resistance of the recording media P3 having different stiffnesses is large, the contact angle αc of the first separation slope with the 42 (FIG. 1).
1), the buckling hardly occurs, so that the vertical force of the feed roller 31 on the recording medium also increases. And the shaft gear train 30
As the recording medium P3 rotates around the rotation center axis 130, the recording medium P3 bends around the corner 28c.

As a result, the recording medium P3 continues to bend until the contact angle γc at which the recording medium P3 bends with respect to the first separation slope. The contact angle to the first separation slope 42 is γc
When (γc <αc), the uppermost recording medium is separated from the lower recording medium.

As the buckling resistance increases as shown in FIG. 12, the recording medium continues to bend and the contact angle with the first separation slope 42 decreases, so that the bending angle θc is set so that double feeding does not occur. Are set so as to obtain stable separation performance.

Therefore, by changing the contact angle of the recording medium to the separation slope so as to be surely separated according to the rigidity of the recording medium, the rigidity of the recording medium such as a thin recording medium and a thick recording medium is different. Double feed, misfeed,
It is possible to prevent a feeding failure such as a jam.

The separation slopes 41, 41 a, 41 b, 42, 43 in each of the embodiments described above are formed by
It is also used as a wall at the downstream end of 1a, 61b, 61c.

In any of the embodiments, the angle δ between the sheet stacking surface and the separation slope for receiving the downstream end of the recording medium is set to about 90 degrees to about 100 degrees. In the section, the downstream end side is set lower than the upstream end side, and the inclination angle with respect to the installation surface of the recording apparatus 1 is set to about 30 degrees to about 90 degrees. This is to make it easier.

[0147]

According to the sheet feeding apparatus of the present invention, the sheet seat in which the vertical force of the feeding roller applied to the uppermost stacked sheet is used by the contact pressure of the sheet feeding means against the recording medium during sheet feeding. As the bending resistance increases, the sheet stacking portion continues to bend, and the sheet stacking portion is bent, so that the contact angle of the sheet with the separation slope can be changed. The sheet separation performance is limited, and the types of sheets that can be applied are not limited, and the sheets can be reliably separated according to the rigidity of the sheet, and feeding failures such as double feed, misfeed, and sheet jam occur. Can be prevented.

According to the sheet feeding apparatus of the present invention, the buckling resistance of the sheet using the vertical force of the feeding roller applied to the stacked uppermost sheet by the contact pressure of the sheet feeding means with the sheet during sheet feeding is reduced. The larger the larger, the larger the sheet continues to increase, and the sheet falls on the concave sheet stacking surface, so that the contact angle of the leading end of the sheet with respect to the separating slope can be changed. The sheet separation performance is limited by such factors, and the types of sheets that can be applied are not limited, the sheet can be reliably separated according to the rigidity of the sheet, and sheet feeding defects such as double feed, misfeed, and jam Can be prevented from occurring.

Since the image forming apparatus of the present invention is provided with the sheet feeding device capable of feeding the sheets one by one, the image can be surely formed on the sheets.

[Brief description of the drawings]

FIG. 1 is a side view of an image forming apparatus provided with a sheet feeding device according to a first embodiment of the present invention, which is a partially sectional view.

FIG. 2 is a diagram illustrating a state in which a sheet is being supplied by a sheet supply device in FIG. 1;

FIG. 3 is a side view of the sheet feeding apparatus according to the first embodiment of the present invention, which is a partially sectional view.

FIG. 4 is a side view of the sheet feeding apparatus according to the first embodiment of the present invention, which is a partial cross-sectional view illustrating a state in which a sheet having higher rigidity than FIG. 3 is being supplied.

FIG. 5 is a side view of the sheet feeding apparatus according to the first embodiment of the present invention, which is a partial cross-sectional view illustrating a state in which a sheet having higher rigidity than FIG. 4 is being supplied.

FIG. 6 is a side view of a sheet feeding apparatus according to a second embodiment of the present invention, which is a partially sectional view.

FIG. 7 is a side view of the sheet feeding apparatus according to the second embodiment of the present invention, which is a partial cross-sectional view illustrating a state in which a sheet having higher rigidity than FIG. 6 is being fed.

FIG. 8 is a side view of a sheet feeding device according to a third embodiment of the present invention, which is a partially sectional view.

FIG. 9 is a side view of the sheet feeding device according to the third embodiment of the present invention, which is a partial cross-sectional view illustrating a state in which a sheet having higher rigidity than FIG. 8 is being fed.

FIG. 10 is a side view of a sheet feeding apparatus according to a fourth embodiment of the present invention, which is a partial sectional view.

FIG. 11 is a side view of a sheet feeding apparatus according to a fourth embodiment of the present invention, which is a partial cross-sectional view;
FIG. 7 is a view showing a state in which a sheet having a rigidity greater than 0 is set.

FIG. 12 is a side view of a sheet feeding apparatus according to a fourth embodiment of the present invention, which is a partial cross-sectional view;
FIG. 3 is a diagram illustrating a state in which a sheet can be supplied from the state of FIG.

FIG. 13 is a side view of a conventional sheet feeding apparatus, which is a partially sectional view.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 recording device (image forming device) 2 drive shaft gear (drive gear) 5 feed roller 11, 11A, 11B, 11C sheet feeder 21, 21a, 21b, 21c sheet stacking part 22, 22a first pressure plate (upstream side) Tilting member) 22b Pressure plate (downward displacement body) 22'b Sheet loading surface 22 ', 22'a Sheet loading surface of first pressure plate 23, 23a Second pressure plate (downstream tilting member) 23', 23'a No. 2 sheet loading surface 23b Convex portion (sheet leading end support) 23'b Sheet loading surface 30 Gear train (rotation transmitting means) 31 Sheet supply rotating body 32 Swinging member 35 Sheet supply means 36, 36a. 36b. 36c sheet stacking means 37 connecting portions 41, 41a. 41b Separation slope 42 First separation slope 43 Second separation slope 61, 61a, 61b, 61c Frame body 62, 62a, 62b, 63 Pressure plate spring (biasing means) 130 Rotation center axis (oscillation center) 221 Recording head (Image Forming Means) 240a, 240b First Sheet Loading Surface 250 Second Sheet Loading Surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinya Sonoda 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Haruyuki Yanagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon In-house F term (reference) 2C059 AA05 AA08 DD05 DD08 DD13 3F343 FA02 FA06 FB02 FB03 FB04 FC01 FC04 GA03 GB01 GC01 GD01 HA12 HB01 HD08 HD09 HD10 HD18 JA01 JD03 JD13 JD40 LA04 LA15 LC02 LC07 LC19 LC20 LD04 LD24

Claims (18)

[Claims] 1. A sheet stacking unit on which sheets are stacked, a sheet feeding unit capable of coming into contact with and separating from the sheets stacked on the sheet stacking unit, and feeding the sheet from the sheet stacking unit; A separating slope for receiving the leading edge of the sheet sent from the sheet stacking means and separating the sheets one by one, wherein the sheet stacking means presses the sheet by the pressing force of the sheet supply means against the sheet. A sheet stacking section capable of supporting the sheet in a bent state. 2. The sheet stacking portion is formed to be bendable by a pressing force of the sheet supply means against the sheet, and is urged toward the sheet supply means by an urging means. 2. The sheet feeding device according to 1. 3. An upstream-side inclined member, wherein the sheet stacking section has a downstream end tilted up and down around an upstream end.
A downstream inclined member whose upstream end side tilts up and down around the downstream end side, and a connecting portion that connects the downstream end of the upstream inclined member and the upstream end of the downstream inclined member so as to be close to and rotatable. 2. The sheet feeding apparatus according to claim 1, wherein at least one of the upstream inclined member and the downstream inclined member is urged toward the sheet supply unit by an urging unit. 3. . 4. An upstream-side inclined member, wherein the sheet stacking section has a downstream end tilted up and down around an upstream end.
A downstream inclined member whose upstream end side tilts up and down around the downstream end side, wherein the upstream inclined member and the downstream inclined member are respectively attached to the sheet supply means side by urging means. The sheet feeding device according to claim 1, wherein the sheet feeding device is energized. 5. The sheet stacking portion is formed such that an upstream end side from an intermediate portion of a sheet stacking surface can be displaced downward by a pressing force of the sheet feeding unit against the sheet, and is biased by the biasing unit. 2. The sheet feeding device according to claim 1, further comprising: a downwardly displaceable member that is biased to the sheet; 6. The sheet feeding apparatus according to claim 5, wherein the sheet leading end support has a loading surface for supporting a leading end of the sheet, and a slope for bending the sheet. 7. The sheet feeding apparatus according to claim 1, wherein the separation slope is disposed near a downstream end of a sheet stacking section of the sheet stacking unit. 8. The sheet according to claim 1, wherein an angle between the sheet stacked on the sheet stacking unit when the sheet is not fed and the separation slope is set to be substantially a right angle. Feeding device. 9. A sheet stacking unit having a sheet stacking unit on which sheets are stacked, and a sheet feeding unit capable of coming into contact with and separating from the sheets stacked on the sheet stacking unit and feeding the sheet from the sheet stacking unit. A separation slope for receiving the leading end of the sheet sent from the sheet stacking unit by the sheet supply unit and separating the sheets one by one, wherein the sheet stacking unit supports the leading end of the sheet.
And a concave second sheet loading surface for dropping an intermediate portion of the sheet supported by the first sheet loading surface by a pressing force of the sheet supply means against the sheet, The first separation slope is provided on the downstream side of the first sheet stacking surface, the second separation slope is provided on the downstream side of the second sheet stacking surface, and the second separation slope is the second separation slope. 1. A sheet feeding device, wherein the sheet feeding device is inclined downstream of the separation slope. 10. The sheet feeding apparatus according to claim 1, wherein a downstream end side of the sheet stacking section is set lower than an upstream end side. 11. The sheet feeding apparatus according to claim 10, wherein the sheet stacking section is inclined at about 45 degrees to about 90 degrees with respect to an installation surface. 12. The sheet stacking means has a frame,
The sheet feeding device according to claim 1, wherein the sheet stacking unit is provided in the frame. 13. The sheet stacking means has a frame provided with the sheet stacking section, the first separation slope is a wall at a downstream end of the frame, and the second separation slope is provided. The sheet feeding device according to claim 9, wherein is formed at an intermediate portion of the frame. 14. An apparatus according to claim 9, wherein an angle between the straight sheet stacked on the first sheet stacking surface and the first separation slope is set to be substantially a right angle.
Or the sheet feeding apparatus according to 13. 15. The sheet supply means is provided at a swinging end of the swinging member, the swinging member having an upstream end side as a swinging center, and is rotatable in a direction in which the sheet comes in contact with the sheet and feeds the sheet. 10. The sheet feeding apparatus according to claim 1, further comprising a rotary sheet feeding rotary member. 16. A sheet supply rotation unit for transmitting rotation to the sheet supply rotating unit through a swing center of the swinging member, wherein the sheet supply rotation unit transmits the sheet supply rotation by a rotational force transmitted to the sheet supply unit. The sheet feeding device according to claim 15, wherein a torque around the swing center is applied to the swing member so as to be urged by a sheet on which a body is stacked. 17. A driving gear having a center of a swing center of the swinging member, and a gear train arranged on the swinging member and transmitting rotation of the driving gear to the sheet supply rotating body. The sheet feeding device according to claim 16, wherein: 18. A sheet supply device according to claim 1, further comprising: an image forming unit configured to form an image on the sheet supplied by the sheet supply device. Characteristic image forming apparatus.