JPH07223758A - Paper width detector, sheet feeder and image forming device - Google Patents

Abstract

PURPOSE:To prevent occurence of wrong detection of paper width due to a difference taking place in a movement starting direction of paper width regulating members by pinching a moving piece of slide volume between two members provided on a movable paper width regulating member side so as to be connected to the movable paper width regulating member side. CONSTITUTION:A lever 50 on side of a rack 34 L which pushes the moving piece 46 of a slide volume 40 linking with the movement of the rack 34 L is rotatably provided, and one end of the lever 50 is energized by a spring 52 so that the lever 50 is pushed to the moving piece 46 of the slide volume 40. The moving piece 46 is retained under such a condition that it is pinched between the lever 50 and a bumping rib 48 by always bringing the lever 50 in contact with the moving piece 46 of the slide volume 40 by means of energy of the spring 52 so that any play between the rack 34 L and the moving piece 46 of the slide volume 40 may be prevented from occur ring even though a side guide, i.e., the rack 34 L is moved right or left. Therefore, the occurrence of wrong detection of paper width due to a difference taking place in a movement starting direction of the side guide is prevented so that accurate paper width detection can be carried out without any error.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a pair of paper width regulating members in which at least one member is a movable member and the distance between the other member and the other member can be widened, and a paper is sandwiched between the two members. The present invention relates to a device that detects a paper width by changing a resistance value of a slide volume by moving a movable paper width regulating member and moving a slider of a slide volume in conjunction with the movement. The present invention also relates to a sheet feeding device including the sheet width detecting device, and an image forming apparatus including the sheet feeding device.

[0002]

2. Description of the Related Art A paper width detecting device as described above is, for example,
It is arranged on a multi-tray of an image forming apparatus equipped with a multi-manual sheet feeding device (sheet feeding device). The multi-manual paper feeder is to introduce paper of any size as a recording material (transfer material) into the image forming apparatus. The width of the paper set in the multi-tray is detected by the paper width detection device, and the detected paper width is detected. Control the exposure area of blank exposure,
Automatic control is carried out to prevent unnecessary toner from adhering to the transfer roller and the subsequent back stain on the transfer material.

Specifically, as a pair of paper width restricting members disposed on the left and right of the upper surface of the multi-tray, at least one of which is movable and can be widely sandwiched according to the paper width of the placed paper so that the space between the other is movable. By moving the slider of the slide volume in conjunction with the movement of the movable side guides of the left and right side guides, the paper width is detected by the change in the resistance value of the slide volume.

Conventionally, as shown in FIG. 5, the movable side guide and the slider of the slide volume are connected to a movable side guide side member which is a paper width regulating member, for example, a rack 100 which slides integrally with the side guide. A slider insertion hole 101 is provided, and the slider 103 of the slide volume 102 fixedly installed is inserted into the hole 101 to connect the side guide side and the slider 103, and to interlock with the movement of the side guide. Slide volume 102
The moving element 103 of No. 1 is moved with respect to the slide volume 102.

[0005]

[Problems to be Solved by the Invention] However, in the case of this connection structure, the larger or smaller hole 1
01 and the mover 103 cause looseness x ₁ + x ₂ . Due to the backlash, the paper width may be erroneously detected depending on the moving start direction of the movable side guide as the paper width regulating member.

[0006] In addition, the difference L between the maximum width and the minimum width of paper that can be fed in the multi-tray is the slide volume 1
If the maximum moving amount M of the moving element 103 of No. 02 is larger than the maximum moving amount M of the moving element 103, or if the maximum moving amount M of the moving element is larger than the difference dimension L, the maximum moving amount M of the moving element is smaller than the difference dimension L. Must create a slide volume 102 for each machine, with a maximum movement M of the moving element M ≧ difference dimension L 2,
It becomes a problem in terms of cost.

In addition, the slide volume 10
A method of increasing the maximum moving amount M of the second moving element 103 may be considered, but there is a problem in that the slide volume becomes large and space is restricted.

The present invention is directed to overcoming the problems set forth above and above.

[0009]

SUMMARY OF THE INVENTION The present invention is a paper width detecting device, a sheet feeding device, and an image forming apparatus having the following features.

(1) At least one member is a movable member and has a pair of paper width regulating members whose distance from the other member can be widened, and the paper width regulating member is movable so as to sandwich the paper between both members. Is a device that detects the paper width by the resistance value change of the slide volume by moving the slider and the slider of the slide volume in conjunction with the movement, and the slider of the slide volume is provided on the movable paper width regulating member side. Two
A paper width detection device characterized in that it is sandwiched between members and connected to a movable paper width regulating member side, and at least one of the two members has a retracting mechanism.

(2) The retracting mechanism is a mechanism for constantly urging the moving member sandwiching member in a direction of being pressed against the moving member and allowing the retracting movement in the opposite direction against the urging force. The paper width detection device according to (1).

(3) The pair of paper width regulating members are both movable and connected to each other via a rack and a pinion, and when one paper width regulating member is moved and operated, the other paper width regulating member also moves to one paper width regulating member. The paper width detection device according to (1), wherein the paper width detection device moves equidistantly in a direction opposite to the direction of the restriction member, and the interval between both paper width restriction members varies widely with respect to the center.

(4) The sheet supporting means for supporting the manually-fed sheet and the sheet supporting means for detecting the sheet width of the sheet supported by the sheet supporting means according to any one of (1) to (3). A sheet feeding device comprising a sheet width detecting device and a sheet feeding means for feeding the sheet.

(5) An image forming apparatus comprising: the sheet feeding device described in (4) above; and an image forming means for forming an image on a sheet fed from the sheet feeding device. .

[0015]

The slide volume moving element is sandwiched between two members provided on the movable paper width regulating member side and is connected to the movable paper width regulating member side, so that the paper width regulating member side and the slide volume moving element are connected to each other. Since there is no looseness in the connecting portion of, the erroneous detection of the paper width due to the difference in the movement start direction of the paper width regulating member is prevented from occurring.

When the paper width regulating member side attempts to move beyond the maximum movement amount of the slider of the slide volume,
Even if the maximum moving amount of the slider of the slide volume is smaller than the moving amount of the paper width regulating member, the moving member sandwiching member retracts by the retracting mechanism and the subsequent movement on the paper width regulating member side is allowed. This makes it possible to save space in the machine without using a long slide volume. Therefore, the above problem can be solved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of an example of an image forming apparatus equipped with a manual paper feeding device provided with a paper width detecting device according to the present invention as seen from the rear side of the device, and FIG. 2 is a schematic view of the internal mechanism of the device. is there. The image forming apparatus of this embodiment is a fixed platen glass fixed-optical system moving type transfer electrophotographic copying machine.

(1) Overall Schematic Structure of Image Forming Apparatus 1 is a machine casing of a copying machine main body, 2 is a fixed platen glass fitted in an opening on the upper surface of the casing, and 3 is openable on the platen glass. Document pressing plates 4 and 4 are console panels arranged on the front side of the upper surface of the machine casing.

The original O is placed on the upper surface of the original glass 2 with the image surface to be copied facing downward and set according to a predetermined placing standard, and the original pressure plate 3 is covered and closed to close the original O. To

A. In the case of the cassette sheet feeding mode In this case, the operator inputs the copy conditions such as the size of the transfer material (recording material) used and the number of copies from the console panel 4 to the control system in advance.

When the copy button is pressed, the manuscript illumination lamp 5a of the movable optical system and the first moving mirror 5b below the manuscript table glass 2 are moved at a predetermined speed V along the lower surface of the manuscript table glass 2 from the left side to the right side. On the original platen glass 2 by moving backward and moving the second and third moving mirrors 5c and 5d in the same direction as the document illumination lamp 5a and the first moving mirror 5b at a speed of V / 2. The downward image surface of the set document O is illuminated and scanned from the left side to the right side, and the reflected light on the original surface of the illumination light is reflected by the first to third moving mirrors 5b, 5c, 5d and the zoom lens 5.
e → Slit imaging exposure on the surface of the electrophotographic photosensitive drum 6 which is rotationally driven at a predetermined peripheral speed (process speed) in the clockwise direction indicated by an arrow via the first to third fixed mirrors 5f, 5g, and 5h. L is done.

The rotary photosensitive drum 6 is charged to a predetermined polarity and potential by a charging roller 7 as a primary charging means.
A slit image forming exposure L of the above-mentioned document image is formed on the charging surface.
By receiving the electrostatic latent image, an electrostatic latent image corresponding to the original image is formed on the surface of the rotary photosensitive drum 6. The electrostatic latent image is developed as a toner image by the developing device 8.

On the other hand, the uppermost transfer material of the transfer materials P stacked and housed in the paper feed cassette 13 installed in the lower part of the main body of the copying machine is fed out by the paper feed roller 14 and the paper feed roller 14 and One sheet of the uppermost transfer material is separated in cooperation with the separation pad 15 pressed against the roller 14 and guided to the registration roller pair 19 by the reversing guide 16, the lower guide 17 and the upper guide 18.

In the copying machine of this embodiment, the paper feeding cassette 13 is mounted / pulled out from the copying machine in a so-called front loading type. The transfer material P stacked and stored in the paper feed cassette 13 is lifted by a pressure plate 13a whose tip end side is pushed up by a spring and urged, so that the top end side upper surface is pressed against the lower surface of the paper feed roller 14 and the paper feed roller 13 is pressed. By the rotation of, the feeding force acts on the uppermost transfer material of the loaded transfer material P.

The transfer material guided to the registration roller pair 19 is subjected to skew correction and registration adjustment by the registration roller pair 19, passes through the transfer guide 20, and comes into pressure contact between the rotating photosensitive drum 6 and the transfer roller 9 at a predetermined timing. By being conveyed to the nip portion (transfer portion), the toner image is sequentially transferred from the rotary photosensitive drum 6 side.

The transfer material having undergone the toner image transfer at the transfer portion is separated from the surface of the rotary photosensitive drum 6 and is conveyed to a fixing device 22 by a conveying device 21. The fixing device 22 heats and fixes the transferred toner image. As an image-formed product (copy), the paper is ejected to the paper ejection tray 24 outside the apparatus by the paper ejection roller 23.

After the transfer of the toner image to the transfer material, the surface of the rotating photosensitive drum is cleaned by a cleaning device 10 to remove residual deposits such as toner remaining after transfer, and the eraser lamp 11 receives static elimination exposure L ₁ . It is subjected to static elimination processing and is repeatedly used for image formation. L ₂ represents blank exposure light. Original illumination lamp 5a, first moving mirror 5b, second
When the third moving mirrors 5c and 5d reach the predetermined forward movement end points, they are returned to the initial forward movement start position (home position).

B. In the case of the multi-manual paper feeding mode, reference numeral 25 denotes a multi-manual paper feeding device section, which is disposed on the right side surface of the copying machine main body. Numeral 26 is a multi-tray of this multi-bypass feeder, which is centered on the hinge shaft on the lower side.
As shown by the chain double-dashed line in FIG. 2, a closed state in which the right side plate of the main body of the copying machine is raised, rotated, folded and stored.
As shown by the solid line in FIG. 2 and FIG. 1, the opening / closing rotation operation is freely performed by tilting outward from the right side plate of the main body of the copying machine and rotating it to the open state of the front downward inclination posture. It is closed when not in use.
It is opened when used.

27L and 27R are a pair of manually inserted transfer material side guides, which are provided on the left and right of the upper surface of the multi-tray 26 and serve as paper width regulating members.

The left and right side guides 27L and 27R are movable members that can freely slide and move on the upper surface of the multi-tray 26 in the left-right direction, and, as will be described later, via the rack and pinion on the rear surface side of the multi-tray 26. They are connected to each other, and when one side guide is slid to the left and right, the other side guide also moves in the opposite direction to the other side guide by the same distance, and the distance between the two side guides 27L and 27R becomes larger. Wide and narrow depending on the central reference.

Therefore, in the multi-manual paper feed mode,
The multi-tray 26 is rotated to the open state, and the distance between the left and right side guides 27L and 27R is made larger than the width of the transfer material to be manually fed, and both side guides 27L and 27R
The transfer material is placed on the multi-tray between 27R, and the side guide is slid in the direction in which the space between the left and right side guides is narrowed to sandwich the transfer material between both side guides. As a result, the transfer material has both side guides 27L and 27R on both sides.
Is regulated on the inner surface of the tray and is aligned on the multi-tray 26 with the central reference.

When the copy button is pressed, the toner image forming process corresponding to the original image on the rotary photosensitive drum 6 is executed as in the case of the cassette sheet feeding mode, and the multi-manual sheet feeding device section 25 is operated. ,
The intermediate plate 28, which is urged by a spring and whose vertical movement is controlled by a cam, rises and the upper surface of the leading end of the transfer material set on the multi-tray 26 is pressed against the manual paper feed roller 29. .

After that, the manual paper feed roller 29 is started to rotate at a predetermined timing, and the feeding force acts on the uppermost transfer material of the set transfer material on the multi-tray 26 so that the leading end of the transfer material is fed by the manual paper feed roller 29. When it is sandwiched between the separation pad 30 pressed against this and the intermediate pad 28, the middle plate 28 lowers.

By the subsequent rotation of the manual paper feed roller 29, the uppermost transfer material of the set transfer material on the multi-tray 26 becomes 1 by the cooperation of the manual paper feed roller 29 and the separation pad 30.
The sheets are separated and fed, and are guided to the registration roller pair 19 by the upper guide 18, the middle guide 31, and the lower guide 17.

The rest is the same as in the case of the cassette sheet feeding mode, and the transfer material from the above-mentioned multi-tray 26 is conveyed to the transfer portion, and the copy by the manual transfer material is discharged to the paper discharge tray 24.

(2) Paper Width Detection Device The multi-manual paper feeder 25 is used to introduce paper of any size, such as A3 width size paper to postcard size paper, as a transfer material into the main body of the copying machine. In the multi-manual paper feed mode, the width of the paper set on the multi-tray 26 is detected by the paper width detection device, and the exposure area of the blank exposure L ₃ is controlled according to the detected paper width to eliminate the need for the transfer roller 9. The automatic control is performed to prevent the adherence of a large amount of toner and the subsequent back stain on the transfer material.

In the present embodiment, by moving the slider of the slide volume by interlocking with the movement of one side guide 27L of the multi-tray 26, the resistance value of the slide volume changes, and the set transfer material on the multi-tray 26 moves. The paper width is detected and the paper width detection information is fed to the control system.

The slide volume is arranged on the back side of the multi-tray 26, and FIG. 3 is a mechanical view of the back side of the multi-tray 26.

Reference numerals 32L and 32R (FIGS. 1 and 3) are elongated guide holes formed in the surface of the multi-tray 26 in the left-right direction.
The left side guide 27L fits and engages two bosses 33L, 33L protruding from the lower surface of the guide with the left guide long hole 32L, so that the left and right guides on the multi-tray 26 are guided by the guide long hole 32L. It is free to slide in any direction. The right side guide 27R has two bosses 33R, 33R protruding from the lower surface of the guide fitted into and engaged with the right guide elongated hole 32R, so that the guide long hole 32R guides the left and right on the multi-tray 26. It is free to slide in any direction.

34L and 34R are left and right racks integrally attached to the left and right side guides 27L and 27R, respectively, on the back side of the multi-tray 26. Left and right side guides 27L for each rack 34L / 34R
-Positioning holes 35L, 35L, 3 at the protruding end of the 27R boss 33L, 33L, 33R, 33R on the back side of the multi-tray
5R and 35R are fitted and engaged, and fixed to the left and right side guides 27L and 27R respectively by screws 36L and 36R.

Therefore, the left and right racks 34L and 34R slide in the left and right directions integrally with the left and right side guides 27L and 27R, respectively, on the rear surface side of the multi-tray 26.

A pinion 37 is rotatably and pivotally attached to the center of the back surface of the multi-tray 26, and is provided on the left and right racks 34L.
The 34R faces the pinion 37 and is meshed with the pinion 37.

That is, the left and right side guides 27L and 27R are provided on the back side of the multi-tray 26 and the left and right racks 34L.
・ 34R and pinion 37 are connected to each other. When one side guide is slid in the left / right direction, the other side guide also moves in the opposite direction from the one side guide by the same distance. The distance between the two side guides 27L and 27R changes widely depending on the center.

38a to 38f are left and right racks 34L.3
A plurality of guide ribs are provided on the back surface of the multi-tray 26 in parallel in the left-right direction in order to stably slide the 4R in the left-right direction. Also 39L, 39L,
39R and 39R are left and right racks 34L and 34R, respectively
The left and right racks 34L and 34R are urged in the direction of the pinion 37 by pressing the spring parts respectively inside the guide ribs 38a and 38d, and the racks 34L and 34R are pinion-mounted. 37 is always held in a tight mesh. The guide ribs 38a to 38f and the spring portions 39L, 39L, 39 described above.
The left and right side guides 27L and 27R and the left and right racks 34L and 34R are smoothly slid and guided in the left and right directions by the R and 39R.

Reference numeral 40 denotes a slide volume, which is arranged in the left-right direction on the base side of the back surface of the multi-tray 26.
This slide volume 40 is a volume holder 41
It is fixed with screws 42 and 42 to the volume holder 41.
Is positioned with respect to the multi-tray 26 by the positioning pins 43, 43 and the fitting engagement holes 44, 44, and fixed by the screws 45, 45 to form a multi-tray unit. 46
Is a slider of the slide volume, and 47 is a lead wire of the slide volume, which is connected to a copying machine control system (not shown).

On the left rack 34L, an abutting rib 48 of a slider 46 of the slide volume 40 and a shaft 49 are provided.
There are provided a lever (arm) 50 that rotates around the center, a spring hook portion 51, and a tension coil spring 52 stretched between the spring hook portion 51 and one end of the lever 50.
The slider 46 of the slide volume 40 is sandwiched between the abutment rib 48 and the other end 50a of the lever 50 which is urged to rotate by the spring 52 without rattling, so that the rack 34L on the left side and the slide volume 40 are separated. The slider 46 is connected to the slider 46, and the slider 46 of the slide volume 40 is linked to the slide movement of the left side guide 27L, that is, the left rack 34L in the left-right direction.
Slide to the left and right with respect to 0.

Therefore, by moving the left and right side guides 27L and 27R as paper width regulating members so as to sandwich the transfer material placed on the multi-tray 26 so as to sandwich the transfer material, the left side guide 27L. The slider 46 of the slide volume moves in association with the movement of the slide volume, and the resistance value of the slide volume becomes a value corresponding to the paper width, and the value is fed to the control system via the lead wire 47 to detect the paper width.

A lower cover is attached to the back surface of the multi-tray 26 to conceal and protect the mechanism on the back surface side of the tray 26.

FIG. 3 shows the left and right side guides 27L and 27R.
Multi-tray 26 when the intervals of A3 size are adjusted
4 shows the state of the back side mechanism of FIG. 4, and FIG. 4 shows the state of the back side mechanism of the multi-tray 26 when adjusted to the postcard size width.

The left and right side guides 27L and 27R are A3
In order to handle the size width of 297 mm to the postcard size width of 100 mm, the amount of movement L of each of the left and right directions is (297 mm-100 mm) /2=98.5 mm.

The maximum moving amount M of the moving element 46 of the slide volume 40 is 100 mm, and it is mechanically compatible with the moving amount M of the rack 34L integrated with the left side guide 27L connected to the moving element 46, which is 98.5 mm. In Although,
Actually, since the rising characteristic of the slide volume 40 side is electrically dull, the tip of the slide volume 4 is about 3 mm.
0 is offset and arranged.

Therefore, with respect to the movement amount L of the rack 27L, the maximum movement amount M of the slider 46 of the slide volume 40 is M.
Causes a small relationship. That is, the left and right side guides 27
When the distance between L and 27R is adjusted to the postcard size width,
Before the left side rack 34L has finished moving the postcard size width of 98.5 mm, the slider 46 on the slide volume 40 side is moved.
Reaches the end point of movement, and further movement is blocked.

However, in this embodiment, when the side guides are continuously moved, the lever 50 pivots in the clockwise direction against the spring about the shaft 49 as shown in FIG. 4, whereby the left and right side guides 27L and 27R are rotated. Is allowed to move at intervals of the postcard size width. At this time, it is not necessary to create a dedicated slide volume having a sufficient length by considering all the post-sized paper widths from the paper width at which the lever 50 starts the retracting rotation as postcards.

That is, in this embodiment, the lever 50 on the rack 34L side that pushes the mover 46 of the slide volume 40 interlocked with the movement of the rack 34L is made rotatable, and one end of the lever 50 is urged by the spring 52 so that the lever 50 is urged. 50 is pressed against the mover 46 of the slide volume 40. When the rack 34L side tries to move beyond the maximum movement amount M of the slider 46 of the slide volume 40, the lever 50
By rotating and retracting
On the other hand, even if the moving amount M of the moving element 46 of the slide volume 40 is smaller, it is possible to cope with the situation.

The lever 50 is always in contact with the moving element 46 of the slide volume 40 by the biasing force of the spring 52, and the moving element 46 is held in a state of being sandwiched between the lever 50 and the abutment rib 48, so that the side guide is provided. 27L, that is, the rack 34L, and the slider 46 of the slide volume 40 are connected, so that the side guide 27L, that is, the rack 34
Even if L is moved leftward or rightward, the rack 34L
Since backlash does not occur between the slider 46 and the slider 46 of the slide volume 40, erroneous detection of the paper width due to the difference in the movement start direction of the side guides is prevented, and accurate paper width detection without error is possible.

An abutment rib 48, which is an opposing member for pinching the moving element 46 of the slide volume 40 in cooperation with the lever 50, is also provided with a retracting mechanism so as to move and urge the moving element 46 in the direction of pressing against the moving element 46. Good.

In the above embodiment, the left and right side guides 27L and 27R as the paper width regulating member are both movable in conjunction with each other, but one side guide is fixed and the other side guide is movable so that both side guides are movable. It is needless to say that the paper width detection device of the present invention can be applied to the one-side reference configuration in which the space between the two is widely sandwiched according to the paper width.

[0058]

As described above, according to the paper width detecting device of the present invention, the sheet feeding device having the paper width detecting device, and the image forming apparatus having the sheet feeding device, the paper width regulating member side and the slide volume are provided. Since there is no looseness in the connecting portion between the moving element and the moving element, erroneous detection of the paper width due to the difference in the movement start direction of the paper width regulating member is prevented from occurring, and accurate paper width detection can be performed without error.

Further, even when the maximum movement amount of the slider of the slide volume is smaller than the movement amount of the paper width regulating member, it is possible to cope with the case, and it is not necessary to use a long slide volume, and the space in the machine can be saved.

[Brief description of drawings]

FIG. 1 is a perspective view of an example of an image forming apparatus including a manual sheet feeding device provided with a paper width detecting device according to the present invention, as viewed from the rear side of the device.

FIG. 2 is a schematic view of the internal mechanism of the device.

FIG. 3 is a state diagram of the back tray side mechanism of the multi-tray when the distance between the left and right side guides is adjusted to the A3 size width.

FIG. 4 is a state diagram of the back tray side mechanism of the multi-tray when the interval between the left and right side guides is adjusted to the postcard size width.

FIG. 5 is a perspective view of a connecting portion of a movable side guide and a slider of a slide volume in a conventional device.

[Explanation of symbols]

1 Copier body 25 Multi-manual paper feed section 26 Multi-tray 27L / 27R Left and right side guides (paper width regulating member) 34L / 34R Left and right racks 37 Pinion 40 Slide volume 46 Mover 48/50 Mover sandwiching member (abutting rib) And pressure lever) 50 Extension spring (biasing member)

Claims (5)

[Claims] 1. A pair of paper width regulating members, wherein at least one member is a movable member so that a space between the other member and the other member can be widened, and a paper width regulating member which is movable so as to sandwich the paper between the both members. This is a device for detecting the paper width by the resistance value change of the slide volume by moving the slide volume moving element in conjunction with the movement, and the slide volume moving element is provided on the movable paper width regulating member side. A paper width detection device characterized in that it is sandwiched between members and connected to a movable paper width regulating member side, and at least one of the two members has a retracting mechanism. 2. The retracting mechanism is a mechanism which constantly urges the moving element sandwiching member in a direction of being pressed against the moving element, and allows the retracting movement in the opposite direction against the urging force. The paper width detection device according to claim 1. 3. The pair of paper width regulating members are both movable and connected to each other via a rack and a pinion, and when one paper width regulating member is moved and operated, the other paper width regulating member is also regulated to one paper width regulating member. 2. The paper width detection device according to claim 1, wherein the paper width detection device moves equidistantly in the opposite direction to the member, and the distance between both paper width regulation members varies widely with respect to the center. 4. The sheet width detecting means according to claim 1, which is provided to detect a sheet width of the sheet supported by the sheet supporting means and a sheet supported by the sheet supporting means. A sheet feeding apparatus comprising: an apparatus; and a sheet feeding unit that feeds the sheet. 5. An image forming apparatus, comprising: the sheet feeding device according to claim 4; and an image forming unit that forms an image on a sheet fed from the sheet feeding device.