JP2942056B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus applied to a recording apparatus such as a printer or an electronic typewriter, which separates stacked sheets one by one and feeds them to a recording unit or the like.

[0002]

2. Description of the Related Art Today, with the development of information processing systems,
In offices and the like, recording devices such as printers and electronic typewriters are used. In the above-described recording apparatus, plain paper, postcards, thick paper such as envelopes, etc. are used as sheets, and the feeding method is such that the automatic feeding apparatus automatically feeds the sheets to the recording unit, and also feeds the sheets one by one manually. Has been adopted. Therefore, the recording apparatus is provided with a feed port for an automatic feeder and a feed port for manual feed.

In the above recording apparatus, as a method of separating sheets one by one, two types of a nail separation method and an inclined plate separation method are generally used. Each separation method separates sheets one by one using the fact that the coefficient of friction between the feeding roller and the sheet is larger than the coefficient of friction between the sheets. Further, when a separation sheet is provided at a position facing the feed roller on the pressure plate on which the sheets are stacked, the friction coefficient between the sheets is substantially equal to the friction coefficient between the sheet and the separation sheet. Is configured to be able to be separated and fed even if the number of sheets decreases.

Further, in the above automatic feeding device, a claw separation method is adopted because it can be generally constructed at a low cost. In order to stably separate and feed a sheet, it is limited to plain paper. In order to feed a cardboard such as a postcard or an envelope, the sheet is fed using a separate automatic feeding device using another separation method, for example, a friction separation method.

[0005]

However, in the above prior art, since the separation sheet protrudes from the pressure plate, when the number of sheets is small, when the sheet is back-fed (reversely conveyed), the rear end of the sheet is However, there is a possibility that the sheet may be jammed (paper jam) by being caught on the separation sheet.

In addition, when using different types of sheets, such as plain paper and thick paper such as postcards and envelopes, it is necessary to change the automatic feeding device to a recording device each time. You need a place to put the equipment. Even if the automatic paper feeder for plain paper is built in the main body and the automatic paper feeder for thick paper is attached and detached, a separate automatic paper feeder is required, leading to an increase in cost. It was necessary to separately provide a manual feed port, and there was a risk that the apparatus would be large and the installation area would be large.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a sheet feeding apparatus which does not cause a jam when a sheet is conveyed backward.

It is another object of the present invention to provide a small-sized and low-cost sheet feeding apparatus capable of feeding sheets regardless of the type of sheet.

[0009]

According to the present invention, there is provided a sheet feeding apparatus comprising: sheet supporting means for stacking and supporting sheets; and sheet feeding means for feeding a sheet supported by the sheet supporting means. A separating member provided at a position where the sheet feeding means of the sheet supporting means faces the sheet separating means, and the separating member on the sheet supporting means.
A projection is provided further downstream in the sheet conveying direction.

Another configuration of the sheet feeding apparatus according to the present invention includes a sheet supporting means for stacking and supporting sheets,
Feeding means for feeding a sheet supported by the sheet supporting means, separating claw for regulating an end portion of the sheets stacked on the sheet supporting means and separating the sheets one by one, and the separating claw the and a switching means selectively switched for a position spaced a position abutting on said sheet supporting means, sheet transport direction from the position where the separating claw on said sheet supporting means is brought into contact with said sheet supporting means A projection is provided on the upstream side.

[0011]

According to the above construction, the projection is provided on the downstream side of the separation member in the sheet conveying direction, so that when the sheet is back-fed, the rear end can be prevented from being caught by the separation member.

[0012] the position where the separating claw comes into contact with the sheet supporting means, by providing the protrusions in the sheet conveyance direction upstream side, in the case where the separation claw is brought into contact with the sheet supporting means by the switching means, the separation claw Since the sheet can be set on the upper side of the separation claw without receiving the resistance, the cardboard such as a postcard or an envelope can be fed. Further, when the separating claw is separated from the sheet supporting means by the switching means, the sheet can be set below the separating member, so that plain paper can be fed.

[0013]

【Example】

[First Embodiment]-An embodiment of a sheet feeding apparatus to which the present invention is applied will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a sheet feeding apparatus, FIG. 2 is a sectional explanatory view thereof, and FIG. 3 is a perspective view of another example of a sheet feeding apparatus.

First, a schematic configuration of a sheet feeding apparatus will be described with reference to FIG. Reference numeral 1 denotes a frame for supporting a feeding mechanism. The frame 1 supports a feeding shaft 2 rotatably. Feed rollers 3a and 3b, which are feed rotating bodies, are attached to the feed shaft 2 so as to be slidable in the axial direction. Guide rings 5a, 5b having grooves 4a, 4b are slidably mounted at predetermined positions of the feed shaft 2. The guide rings 5a, 5b are engaged with the U-grooves 7a, 7b of the sheet regulating guides 6a, 6b for guiding the sheet in the width direction, so that the grooves 4a, 4b engage with the sheet regulating guides 6a, 6b.
Is configured to be slidable in the axial direction together with. Further, a drive gear 8 for transmitting a driving force from a drive source (not shown) is integrally attached to one end of the feed shaft 2.

The sheet supporting means includes a support plate 9 and the support plate.
9 from sheet regulation guides 6a and 6b mounted on
It is configured. The support plate 9 holds sheets and feeds
It is pressed against the bearings 3a and 3b, and is attached to both sides of the frame 1 so as to be rotatable about a rotation fulcrum 9a. As shown in FIG. Thus, the pressure is applied to the feed rollers 3a and 3b. Sheet regulating guide 6a, 6b is supported
It is slidably mounted on the holding plate 9 in the width direction. On the sheet regulating guides 6a and 6b, cam receiving portions 6c and 6d are formed which come into contact with the rotation of the pressure release cams 11a and 11b, which will be described later, and the supporting plate 9 is provided together with the sheet regulating guides 6a and 6b. The feed rollers 3a and 3b are configured to be pushed down.

Reference numerals 12a and 12b denote separation claws, which press the sheet with claw portions 12c and 12d arranged at the corners in the sheet feeding direction. The separation claws 12a, 12b are provided on the side surfaces of the sheet regulating guides 6a, 6b with rotation fulcrums 12e, 12f.
Is mounted so as to be rotatable around the support plate 9 and is normally configured to abut on the support plate 9 by its own weight. still,
In this embodiment, the sheet feeding device is brought into contact with its own weight. However, when the sheet feeding device is used in an inclined state, the sheet feeding device may be configured to be positively biased toward the support plate 9 by a spring or the like.

The claw portions 12c, 12 of the separation claws 12a, 12b
Push-down portions 12g and 12h which are in contact with the claw open cams 11c and 11d formed on the pressure release cams 11a and 11b are formed at the end opposite to d. Press-release cam 11
When the push-down sections 12g and 12h are pushed down by the pawl open cams 11c and 11d by rotating the a and 11b,
A and 12b rotate clockwise as shown in FIG. 2 around rotation fulcrums 12e and 12f, and the claw portions 12c and 12d are configured to be separated from the support plate 9.

The above-mentioned press-release cams 11a and 11b are used to release the press-contact of the sheet by the support plate 9 with respect to the feed rollers 3a and 3b. The press-contact release cams 11a and 11b are
Both ends are integrally attached to a cam shaft 13 rotatably supported by the frame 1. At one end of the cam shaft 13, a pressure release lever 14 as a switching means is attached. By operating the pressure release lever 14, the rotational force is applied to the pressure release cams 11a and 11b via the cam shaft 13. Is transmitted. The press-release cams 11a and 11b are provided with cam receiving portions 6c and 6d provided on the sheet regulating guides 6a and 6b.
The sheet regulating guide 6
It is configured to slide along the cam shaft 13 in conjunction with the sliding operations of a and 6b.

Reference numerals 15a and 15b denote inclined plates for separating and feeding thick paper such as postcards and envelopes. As shown in FIG.
When the thick papers such as postcards and envelopes stacked above the separation claws 12a and 12b are fed by the feed rollers 3a and 3b in a state where the claw portions 12c and 12d of the separation claws 12a and 12b are in contact with the support plate 9, The leading edge of the thick paper hits the inclined surfaces 15c and 15d of the inclined plates 15a and 15b, and only the uppermost sheet pressed against the feed rollers 3a and 3b is fed by the resistance caused by the paper strain generated there. The inclined plates 15a and 15b are provided with arms 15e and 15
f, it is engaged with the feed shaft 2 and is configured to be sandwiched by guide rings 5a, 5b attached to the feed shaft 2 and to slide in conjunction with the slide operation of the sheet regulating guides 6a, 6b. I have.

Reference numerals 16a and 16b denote separation sheets serving as separation members.
When the support plate 9 is urged by the pressure spring 10, the feed rollers 3a, 3b are provided.
b. Since the coefficient of friction between the feed rollers 3a, 3b and the sheet is larger than the coefficient of friction between the sheets, the sheets can be separated one by one from the feed rollers 3a, 3b. Also sheet and separation sheet 16
Since the coefficient of friction with a and 16b is substantially equal to the coefficient of friction between the sheets, the sheets stacked on the support
You can feed up to sheets.

The projections 17a and 17b are formed on the sheet regulating guides 6a and 6b on the downstream side of the separation sheets 16a and 16b in the sheet conveying direction. These projections 17a, 17
b prevents the trailing edge of the fed sheet from being caught on the separation sheets 16a and 16b when the fed sheet is back-fed during recording.

FIG. 2 is an enlarged view around the projections 17a and 17b.
(B). The height of the projections 17a and 17b is
Since the sheet is lower than the sheets a and 16b, the sheet does not catch on the projections 17a and 17b in the normal feeding state. Also the above protrusion
The extension line of the inclination of 17a, 17b is formed so as to be guided to a position higher than the separation sheets 16a, 16b.
It does not catch on 16a and 16b.

According to the above configuration, the separation sheets 16a, 16b
Sheet regulation guides 6a, 6 further downstream in the sheet conveying direction.
By forming the projections 17a and 17b on the sheet b, the normal feeding of the sheet is not affected, and when the fed sheet is back-fed, the rear end of the sheet is separated into the separation sheets 16a and 16b. Can be prevented from being caught on the vehicle.

Second Embodiment Next, another embodiment of the sheet feeding apparatus will be described with reference to FIG. In this embodiment,
A sheet feeding device using one-claw separation is used. In FIG. 3, reference numeral 18 denotes a feeding roller for feeding the sheet, and 19 denotes a support plate for stacking the sheet and pressing the feeding roller 18. The support plate 19 is attached so as to be rotatable about a rotation fulcrum 19a, and is urged toward the feed roller 18 from the back side by a pressure spring (not shown).

On one side surface of the support plate 19, there is formed a convex portion 19b which comes into contact when the pressure release cam 20 described later rotates, and this convex portion 19b is formed on the cam surface 20 of the pressure release cam 20.
The feed roller 18 is configured to be pressed down by the feed roller 18 while being in contact with any one of b and 20c.

Reference numeral 21 denotes a separating claw, which presses the corner of the sheets stacked on the support plate 19 in the feeding direction by a claw portion 21b. The separation claw 21 is attached to a sheet regulating guide (not shown) so as to be rotatable around a rotation fulcrum 21a, and is normally configured to abut against the support plate 19 by its own weight. In this embodiment, the sheet is brought into contact with its own weight. However, when the sheet feeding device is used in an inclined manner as in the first embodiment, the sheet feeding device is positively urged toward the support plate 19 by a spring or the like. It may be configured as follows.

A push-down portion at which only the cam surface 20b of the pressure release cam 20 comes into contact with an end of the separation claw 21 opposite to the claw portion 21b.
21c is formed, and when the press-down portion 21c is pressed down by the press-contact release cam 20, the claw portion 21b is supported by a support plate so as to rotate clockwise around the rotation fulcrum 21a.
It becomes a state separated from 19.

The above-mentioned press-release cam 20 is connected to the support plate 19.
And presses the sheet against the feed roller 18, and the both ends are integrally attached to a cam shaft rotatably supported by a frame (not shown). The press-contact release cam 20 includes a cam surface 20b for simultaneously rotating the support plate 19 and the separation claw 21, and a cam surface 20c for rotating only the support plate 19.
And rotates about the rotation fulcrum 20a. A cam gear 20d is formed around the rotation fulcrum 20a, and is configured to mesh with a lever gear 22a integrally attached to the pressure release lever 22. The pressure release lever 22 is provided on the side of the support plate 19 with a lever fulcrum 22b.
The pressing force release lever 22 is operated to rotate the lever gear 22
a, is transmitted to the press-contact release cam 20 via the cam gear 20d.

Reference numeral 23 denotes a separation sheet, which is provided on the support plate 19 at a position facing the feed roller 18.
Is urged by the pressure spring from the back side, the feed roller 18
Is pressed against. As described above, since the coefficient of friction between the sheet and the separation sheet 23 is substantially equal to the coefficient of friction between the sheets, the sheet loaded on the support plate 19 can be fed up to the last sheet.

Reference numeral 24 denotes a rib, which is formed on the support plate 19 downstream of the separation sheet 23 in the sheet conveying direction.
The ribs 24 prevent the trailing edge of the sheet from being caught on the separation sheet 23 when the fed sheet is back-fed during recording. The ribs 24 are formed lower than the separation sheet when the sheet is fed normally, so that the ribs 24 do not hinder the sheet.

Third Embodiment Another example of the sheet feeding apparatus shown in the first embodiment will be described with reference to FIGS. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In this embodiment, as shown in FIG. 4, separation pawls 12a and 12b for regulating the ends of the sheets stacked on the support plate 9 are used as separation members, and the separation sheets 16a and 16b are omitted. Further, as shown in FIG. 5, the sheet restricting guides 6a and 6b are moved from the position where the separation claws 12a and 12b come into contact with the support plate 9 above.
Are provided on the upstream side in the sheet conveying direction.

When the claw portions 12c and 12d of the separation claws 12a and 12b are in contact with the support plate 9, projections 25a and 25b are provided so that the claw portions 12c and 12d do not protrude from the paper passing surface. Even if the sheet is set, the separation claws 12a, 12
The corners of the sheet do not get caught on the claw portions 12c and 12d of b.

Next, the feeding operation when plain paper is used as a sheet and when thick paper such as postcards and envelopes are used in the above configuration will be described with reference to FIGS. When the plain paper is fed, as shown in FIG. 6, since the pressure release lever 14 is at the feed position, the pressure release cams 11a and 11
The cam surface b does not abut against the cam receiving portions 6c and 6d of the sheet regulating guides 6a and 6b, and the pawl open cams 11c and 11d do not abut against the depressed portions 12g and 12h of the separation claws 12a and 12b. The plate 9 presses the sheet S against the feeding rollers 3a and 3b, and the claw portions 12c and 12d of the separation claws 12a and 12b press the corners of the sheet S in the feeding direction. Therefore,
When the feed rollers 3a, 3b are rotated in the direction of the arrow in the figure,
The uppermost sheet S can be fed one by one.

Next, the operation of setting the sheet S on the support plate 9 will be described. As shown in FIG. 7, the press release lever 14 is rotated in the direction of the arrow (counterclockwise) in the figure. At this time, the pressure release cam 11 attached to the cam shaft 13
a and 11b also rotate in the same direction, the cam surfaces abut against the support plate 9 and push it down, and the pawl open cams 11c and 11d abut against the push-down portions 12g and 12h to push it down, and
12c and 12d are spaced apart from the support plate 9 side to feed rollers 3a,
Retreat to 3b side. In this state, when the sheets S are stacked on the support plate 9 and the sheet regulating guides 6a, 6b are slid according to the width of the sheets S, the feeding rollers 3a, 3
b, the separation claws 12a and 12b, the press-contact release cams 11a and 11b, and the inclined plates 15a and 15b are coaxial or engaged with each other, and slide in conjunction with the sheet regulating guides 6a and 6b.
It is possible to correspond to various sheet widths. When the press release lever 14 is rotated in the reverse direction (clockwise) and returned to the feeding position again, the support plate 9
Is pressed against the feed rollers 3a, 3b, and the separation claws 12a, 12b
The claw portions 12c and 12d are rotated by their own weights to press the corners of the sheet S in the feeding direction, so that the sheet S can be fed.

Next, a case where thick paper such as a postcard or an envelope is fed will be described. As shown in FIG.
Is rotated in the direction of the arrow (clockwise) in the figure, the press-release cams 11a and 11b attached to the cam shaft 13 also rotate in the same direction, and the cam surface comes into contact with the support plate 9 to push it down. , The claw open cams 11c and 11d are pushed down
The hooks 12c and 12d are in contact with the support plate 9 by their own weight because they do not come into contact with g and 12h. When cardboard such as postcards and envelopes are stacked on the support plate 9 in this state, the separation claws 12a and 12b
Since the claw portions 12c and 12d are located at a lower position on the downstream side than the protrusions 17a and 17b provided on the sheet regulating guides 6a and 6b, the protrusions 17a and 12d are not caught by the claw portions 12c and 12d.
Load smoothly along 17b, and the tip is inclined plate 15
a and 15b are set in contact with the inclined surfaces 15c and 15d.
When the pressure release lever 14 is rotated in the reverse direction (counterclockwise) and returned to the feeding position again, the support plate 9 presses the sheet S against the feeding rollers 3a and 3b.
The corners are not held down by the claws 12c, 12d of 12a, 12b. When the feeding rollers 3a and 3b are rotated in this state, the separated feeding is performed by the inclined plates 15a and 15b.

Next, the operation for manually feeding a sheet will be described. As shown in FIG. 9, when the pressing release lever 14 is rotated in the direction of the arrow (clockwise) in a state where the sheets S are stacked on the support plate 9, the pressing release cam 11 is rotated.
The support plate 9 is pushed down by the feed rollers 3a and 3b by the a and 11b. Also, the claw portions 12c, 12c of the separation claws 12a, 12b.
"d" is rotated by its own weight and is in a state of pressing the corner of the sheet S in the feeding direction. In this state, another sheet S '
Is set on the sheet S, the set sheet S 'is placed on the upper side of the separation claws 12a and 12b, and the press release lever 14 is rotated in the reverse direction (counterclockwise) to return to the feeding position. And the support plate 9 feeds the sheet S 'to the feeding roller 3
The sheet S 'can be fed only by rotating the feeding rollers 3a and 3b while being pressed against the sheets a and 3b.

According to the above configuration, the projections 17a, 17b are provided on the upstream side in the sheet conveying direction from the position where the separation claws 12a, 12b abut on the support plate 9, so that the pressure release lever 14 is operated to operate the separation claws. When the sheets 12a and 12b are brought into contact with the support plate 9, the sheet can be set above the separation claws 12a and 12b without receiving the resistance of the separation claws 12a and 12b. Can be sent. When the press release lever 14 is operated to separate the separation claws 12a, 12b from the support plate 9, the sheet can be set below the separation claws 12a, 12b, so that plain paper can be fed. . Further, the position where the separation claws 12a and 12b abut on the support plate 9 by operating the pressure release lever 14 and the position of the support plate 9
By switching to a more distant position, automatic paper feed and manual paper feed can be switched. Therefore, it is possible to reduce the size and cost of the apparatus and obtain a sheet feeding apparatus which is excellent in usability.

[Fourth Embodiment] Another example of the sheet feeding apparatus shown in the second embodiment will be described with reference to FIG.
The same members as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted. The present embodiment relates to a sheet feeding apparatus using one-claw separation, and as shown in FIG.
The separation claw 21 for regulating the end of the sheet stacked thereon is used, and the separation sheet 23 is omitted. Further, a rib 26 is provided instead of a projection on the upstream side in the sheet conveyance direction from a position where the separation claw 21 contacts the support plate 19.

The rib 26 is formed at a height such that the claw portion 21 b does not protrude from the paper passing surface of the support plate 19 when the claw portion 21 b of the separation claw 21 is in contact with the support plate 19. Therefore, when the separation claw 21 is in contact with the support plate 19, the sheet is
Even if they are stacked on top of each other, they can be set without being caught by the claw portion 21b of the separation claw 21.

Next, the feeding operation when plain paper is used as a sheet and when thick paper such as a postcard or an envelope is used in the above configuration will be described with reference to FIGS. When the plain paper is fed, as shown in FIG. 11, since the press release lever 22 is at the feed position, both the cam surfaces 20b and 20c of the press release cam 20 have the convex portions 19b and Separation claw
The support plate 19 presses the sheet S against the feed roller 18 because the sheet S is not in contact with the press-down portion 21c of the separation claw 21.
Of the sheet S presses the corner of the sheet S in the feeding direction. Therefore, when the feed roller 18 is rotated in the direction of the arrow in the figure, the uppermost sheet S can be fed one by one.

Next, the operation of setting the sheet S on the support plate 19 will be described. As shown in FIG. 12, the pressure release lever 22 is rotated in the direction of arrow a (clockwise) in the figure. At this time, the cam gear 20d meshing with the lever gear 22a rotates, and the press-contact release cam 20 moves in the opposite direction (counterclockwise direction).
And the cam surface 20b comes into contact with the support plate 19 and is pushed down,
Since the depressing portion 21c of the separation claw 21 is pressed down,
21b is separated to the feed roller 18 side. In this state, the sheet S
Is stacked on the support plate 19, and the press release lever 22 is returned to the feeding position again.
The separation claw 21 is pressed against the sheet 18 and presses the corner of the sheet S in the feeding direction, so that the plain paper can be fed.

Next, a case where thick paper such as a postcard or an envelope is fed will be described. As shown in FIG.
Is rotated in the direction of arrow b (counterclockwise) in the figure, the press release cam 20 rotates in the opposite direction (clockwise) via the cam gear 20d meshing with the lever gear 22a, and only the cam surface 20c acts. The pressing release cam 20 is
Although this is pushed down only by 19, it does not come into contact with the push-down portion 21c, so that the claw portion 21b of the separation claw 21 rotates by its own weight and comes into contact with the support plate 19. When thick paper such as postcards and envelopes is stacked on the support plate 19 in this state, the ribs 26 are guided and placed above the claw portions 21b of the separation claws 21, so that the pressure release lever 22 is returned to the feeding position. However, the cardboard is not pressed by the separation claw 21. Therefore, in this case, when the feed roller 18 is rotated, thick paper can be fed by friction separation instead of claw separation.

Next, the operation when the sheet is manually fed will be described. As shown in FIG. 14, when the pressure release lever 22 is rotated in the direction of arrow b (counterclockwise) in a state where the sheets S are stacked on the support plate 19, the pressure release cam
By the cam surface 20b of 20, the claw portion 21b of the separation claw 21 is rotated by its own weight, and the support plate 19 is pushed down while holding the corner of the sheet S in the feeding direction. When another sheet S 'is set on the sheet S in this state,
Since the set sheet S 'is placed on the upper side of the claw portion 21b of the separation claw 21, the press release lever 22 is rotated in the reverse direction (clockwise) to return to the feeding position. By pressing S 'against the feed roller 18, only the sheet S' can be manually fed. Accordingly, it is not necessary to provide a separate feeding port, and the sheet can be manually fed in combination with the automatic feeding device, so that the size and cost of the device can be reduced.

FIG. 15 shows an example of an image forming apparatus equipped with the sheet feeding apparatus shown in the above embodiment. The image forming means of this image forming apparatus employs an ink jet method, and the ink jet method forms an image by discharging ink from a discharge port by growth of bubbles generated by heating exceeding film boiling by an electrothermal transducer. Is what you do.

In FIG. 15, reference numeral 27 denotes a recording head.
This is to form an image by discharging ink from a discharge port to a sheet according to image information. The recording head 27
Horizontal direction along guide rail 28 (perpendicular to paper)
The carriage 29 is supported by a reciprocally movable carriage 29.

A platen 30 is provided at a position facing the recording head 27, and the sheet S sent from the above-mentioned sheet feeding device is intermittently conveyed onto the platen 30 by a conveying roller pair 31. Then, the recording head 27 is scanned to sequentially form images. Sheet S after image formation
Is sent out onto a discharge tray 33 by a discharge roller pair 32.

In this way, images can be formed on various sheets such as plain paper, postcards, envelopes, etc. sent from the sheet feeding apparatus, and the versatility of the apparatus can be improved. Incidentally, the image forming means is not limited to the ink jet type, but may be of any other type.

[0048]

As described above, according to the present invention, by providing the projection on the downstream side of the separation member in the sheet conveying direction, it is possible to prevent the rear end from being caught by the separation member when the sheet is back-fed. And the reliability of the device can be improved.

Further, by providing a projection on the upstream side in the sheet conveying direction from the position where the separating member comes into contact with the sheet supporting means, when the separating member comes into contact with the sheet supporting means by the switching means, Since the sheet can be set on the upper side of the separation member without receiving resistance,
Cardboard such as postcards and envelopes can be fed.

When the switching member separates the separating member from the sheet supporting member, the sheet can be set below the separating member, so that plain paper can be fed.

Further, by switching the separating member between a position where the separating member is in contact with the sheet supporting means and a position where the separating member is separated from the sheet supporting means by the switching means, automatic paper feeding and manual paper feeding are switched from the same feeding port. Therefore, miniaturization and cost reduction of the device can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of a sheet feeding apparatus according to a first embodiment.

FIG. 2 is an explanatory sectional view of the sheet feeding device.

FIG. 3 is a perspective view of a sheet feeding device according to a second embodiment.

FIG. 4 is a perspective view of a sheet feeding device according to a third embodiment.

FIG. 5 is a partially enlarged explanatory view of the sheet feeding device.

FIG. 6 is an explanatory diagram of a feeding operation when plain paper is used as a sheet.

FIG. 7 is an explanatory diagram showing a setting operation of the sheet.

FIG. 8 is an explanatory diagram of a feeding operation when thick paper is used as a sheet.

FIG. 9 is an explanatory diagram of a manual feeding operation.

FIG. 10 is a perspective view of a sheet feeding apparatus according to a fourth embodiment.

FIG. 11 is an explanatory diagram of a feeding operation when plain paper is used as a sheet.

FIG. 12 is an explanatory diagram showing a sheet setting operation.

FIG. 13 is an explanatory diagram of a feeding operation when thick paper is used as a sheet.

FIG. 14 is an explanatory diagram of a manual feeding operation.

FIG. 15 is an explanatory diagram illustrating an example of an image forming apparatus to which the sheet feeding device is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Frame 2 ... Feeding shaft 3a, 3b, 18 ... Feeding roller 4a, 4b ... Groove 5a, 5b ... Guide ring 6a, 6b ... Sheet regulating guide 6c, 6d ... Cam receiving part 7a, 7b ... U groove part 8 ... Driving gear 9, 19 Support plate 10 Pressure springs 11a, 11b, 20 Press-release cams 11c, 11d Claw open cams 12a, 12b, 21 Separating claws 12c, 12d, 21b Claw portions 12e, 12f, 19a , 20a, 21a ... Rotating fulcrum 12g, 12h, 21c ... Depressing part 13 ... Camshaft 14, 22 ... Press-release lever 15a, 15b ... Inclined plate 15c, 15d ... Inclined surface 15e, 15f ... Arm 16a, 16b, 23 ... Separation Sheet 17a, 17b, 25a, 25b Projection 19b Projection 20b, 20c Cam surface 20d Cam gear 22a Lever gear 22b Lever fulcrum 24, 26 Rib 27 Recording head 28 Guide rail 29 Carriage 30 Platen 31 … Conveyor roller pair 32… Discharge roller pair 33… Discharge tray

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Soichi Hiramatsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Haruyuki Yanagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Hiroyuki Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tetsuo Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. ( 72) Inventor Masahiro Taniguro 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Takashi Nojima 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Inside Canon Inc. (56) Reference Document JP-A-5-24700 (JP, A) Japanese Utility Model Application Showa 60-148744 (JP, U) Japanese Utility Model Application Showa 62-144842 (JP, U) Japanese Utility Model Application Utility Model Hei 4-22436 (JP, U) Minute Field (Int.Cl. ⁶ , DB name) B65H 1/00-3/68

Claims (6)

(57) [Claims] 1. A sheet supporting means for stacking and supporting sheets, a feeding means for feeding a sheet supported by the sheet supporting means, and the sheet supporting means for separating the sheets. feeding means and a separation member provided at a position facing said sheet supporting means on the separating member sheet feeding apparatus is characterized by providing a protrusion in the sheet conveyance direction downstream side of the. 2. The sheet feeding device according to claim 1, wherein the protrusion is a rib. 3. An image forming apparatus comprising: the sheet feeding device according to claim 1; and an image forming unit configured to form an image on a sheet fed from the sheet feeding device in accordance with image information. . 4. A sheet supporting means for stacking and supporting sheets, a feeding means for feeding a sheet supported by the sheet supporting means, and an end of the sheet stacked on the sheet supporting means. A separating claw for regulating and separating the sheets one by one; and a switching means for selectively switching a position where the separating claw comes into contact with the sheet supporting means and a position where the separating claw is separated from the sheet supporting means. A sheet feeding device, wherein a projection is provided on the upstream side in the sheet conveying direction from a position where the separation claw contacts the sheet supporting means. 5. The sheet feeding device according to claim 3, wherein the protrusion is a rib. 6. An image forming apparatus comprising: the sheet feeding device according to claim 4; and an image forming unit configured to form an image on a sheet fed from the sheet feeding device in accordance with image information. .