JP2000219352A - Sheet conveying device and image forming device - Google Patents

Abstract

(57) Abstract: The present invention removes frictional static electricity generated in a sheet by a curl removing unit or a curl applying unit, and prevents the occurrence of skewing due to sticking of the sheet or occurrence of a jam due to a conveyance delay. It is an object of the present invention to provide a transport device and an image forming apparatus provided with the transport device. SOLUTION: A driving roller 31a and a curling roller 31 are provided.
A discharging member 33 for removing charges charged on the sheet P is provided near the downstream side of the curl applying means constituted by b and 31c, and is electrically connected to the apparatus main body A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sheet conveying device provided in an image forming apparatus such as a copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art Conventionally, a sheet conveying device provided in an image forming apparatus such as a facsimile or a printer has a curl removing means for removing the curl of a sheet and a curl applying means for imparting a desired curl. The sheet is passed through each pair of rollers, such as a sponge roller type or a type in which two rollers are pressed against one roller, to remove the curl of the sheet, or conversely, the desired curl Was granted.

In particular, in a color copier or the like of a type in which a toner image formed on a photosensitive drum is transferred after a sheet is electrostatically attracted on a transfer drum, a recent diversification of sheet types (materials) has occurred. In general, in order to supplement the adsorbability of the sheet to the transfer drum due to an increase in the thickness of the sheet or the like, not only the electrostatic force but also the curling of the sheet along the transfer drum is generally performed.

[0004]

However, in general, in order to effectively curl the sheet more effectively, the pressing pressure of the curling roller pair is increased, or the sheet at the entrance and the exit of the curling roller pair is increased. In either case, the angle and the like of the conveyance path are changed, but the sheet is pulled and curled by a pair of curling rollers, so that the sheet pulling force and the amount of sheet pulling become extremely large.

For this reason, when the sheet passes through the pair of curling rollers, static electricity is generated due to iron friction and the sheet is charged, so that the sheet is moved downstream in the sheet conveyance direction (hereinafter simply referred to as “downstream”) by the electrostatic force. Side), there is a risk that jamming or the like may occur due to skew or conveyance delay.

FIGS. 6 (a) and 6 (b) are views showing an example of a state of skew when 50 sheets of A4 size plain paper are continuously fed horizontally in a conventional apparatus. The vertical axis in FIG. 6A shows the positional deviation (unit: mm) between the front end and the rear end at one side end in the sheet conveyance direction, and the horizontal axis shows the number of sheets. The vertical axis in FIG. 6B indicates the positional deviation (unit: mm) between the front end and the rear end at one side end in the sheet conveyance direction, and the horizontal axis indicates the feed of 50 sheets fed continuously in a row. Indicates the order number.

As shown in FIGS. 6 (a) and 6 (b), it can be seen that the sheet is partially adhered to a conveyance guide or the like on the downstream side of the curling roller pair and largely skews right and left. In the above configuration, the curl amount (height) of the sheet when the A3 size thick paper is passed is as shown in Table 1 below.

[0008]

[Table 1]

In order to solve the above problem, the gap between the pair of conveying guides facing each other in the sheet conveying path on the downstream side of the pair of curling rollers is reduced so that the sheet conveying force of the pair of curling rollers is increased in the sheet and sheet conveying directions. There is also a sheet which stably conveys a sheet which is easily transmitted and partially adhered to a conveyance guide or the like.

FIGS. 7 (a) and 7 (b) show a case where 50 sheets of A4 size plain paper are continuously fed laterally in a case where the gap between the above-described transport guide pairs is made small (for example, at an interval of about 2 mm). It is a figure which shows an example of the aspect of skew. FIG.
The vertical and horizontal axes of (a) and (b) are the same as those in FIG.
The same applies to the vertical and horizontal axes in FIG.

As shown in FIGS. 7A and 7B, the interval between the pair of conveying guides is reduced, and the sheet conveying force by the curling roller pair is easily transmitted to the sheet.
It can be seen that the skew amount of the sheet is greatly reduced as compared with (a) and (b), and the skew is concentrated on one of the left and right sides. In the above configuration, the curl amount (height) of the sheet when the A3 size thick paper is passed is as shown in Table 2 below.

[0012]

[Table 2]

When the gap between the pair of conveying guides is reduced, the curl amount applied to the sheet by the curling roller pair is reduced so that the curl amount is reduced by comparing Table 2 and Table 1. There is also a problem that a desired curl cannot be imparted because the sheet is returned by being sandwiched between the paired conveyance guides.

The present invention solves the above-mentioned problems, and
An object of the present invention is to provide a sheet conveying apparatus and a sheet conveying apparatus for removing frictional static electricity generated on a sheet by a curl removing unit or a curl applying unit to prevent occurrence of a skewing due to sticking of the sheet or a jam due to a conveyance delay. To provide an image forming apparatus.

[0015]

According to a first aspect of the present invention, there is provided a sheet conveying apparatus which is arranged on a conveying path for conveying a sheet and removes curls formed on the sheet. Alternatively, a charge removing member for removing charges charged on the sheet is provided in the vicinity of the downstream side in the sheet conveying direction of the curl applying means for curling the sheet.

According to the above construction, the static electricity generated on the sheet by the curl removing means or the curl applying means is removed by the charge removing member, thereby preventing the occurrence of skewing due to the sticking of the sheet or the occurrence of a jam due to a delay in conveyance. I can do it.

In the case where the static elimination member is constituted by a sheet-like member arranged in the vicinity of a sheet which comes into contact with or passes through the sheet, durability performance is improved as compared with a thin metal needle-like member. In addition, even if the charge removing member is cut due to sheet conveyance or the like, no damage is caused to other components.

A typical configuration of the image forming apparatus according to the present invention includes the sheet conveying device, an image forming unit for forming a toner image according to image information, and a toner image formed on the image forming unit. And a curl removing means or a curl applying means, and the charge removing member is provided upstream of an image transfer position between the image forming means and the transfer means in a sheet conveying direction. ,
Further, the static elimination member is electrically connected to the apparatus main body through an electric resistance member having a predetermined electric resistance value, and the electric resistance value of the electric resistance member is transferred from the curl removing unit or the curl applying unit to the image transfer. Each member capable of contacting the sheet on the conveyance path to the position is configured to have a larger electrical resistance value with respect to the apparatus main body.

According to the above arrangement, each member which can come into contact with the sheet on the conveyance path from the curl removing means or the curl applying means to the image transfer position has an electric resistance larger than the electric resistance of the apparatus main body. Since the static elimination member is electrically connected to the apparatus main body via the member, high-voltage current during image transfer or when the sheet is attracted to the transfer unit is prevented from escaping from the static elimination member via the sheet. Thus, it is possible to stably curl the sheet while maintaining a good image forming state.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a sheet conveying apparatus according to the present invention and an embodiment in which the present invention is applied to a full-color image forming apparatus. First, a first embodiment of an image forming apparatus including a sheet conveying device according to the present invention will be described with reference to FIGS.

FIG. 1 is a cross-sectional view showing the structure of an image forming apparatus provided with a sheet conveying device according to the present invention, and FIG. 2 is a cross-sectional view showing the structure of a curl applying means provided in the sheet conveying device according to the present invention. FIGS. 3 and 4 are cross-sectional explanatory views showing the configuration around the curl applying means and the charge removing member provided in the sheet conveying apparatus according to the present invention. FIGS. 4A and 4B show 50 sheets of A4 size plain paper. It is a figure which shows an example of the skew amount at the time of continuous horizontal feed.

In FIG. 1, a full-color image forming apparatus main body A is provided with a digital color image reader section B at an upper portion and a digital color image printer section C at a lower portion.

An original D is placed on an original platen glass 26 in a digital color image reader section B, and is exposed and scanned by an exposure lamp 27 so that a reflected light image from the original D is converted into a lens.
The light is condensed by 28 and received by a full-color CCD (charge coupled device) sensor 29 to obtain a color separation image signal. This color-separated image signal is processed in a video processing unit via an amplifier circuit (not shown) and sent to a digital color image printer unit C.

In the digital color image printer section C, an electrophotographic photosensitive drum 1 which is an image forming means and serves as an image carrier is rotatably supported in a clockwise direction in FIG. Pre-exposure lamp 11, corona charger 2, laser exposure optical system 3, potential sensor 12, four developing units 4y, 4c, 4m, 4Bk of different colors, yellow, cyan, magenta, and black, on photosensitive drum 1. A light amount detecting unit 13 for detecting a light amount, a transfer device 5 serving as a transfer unit, a cleaning device 6, and the like are arranged.

In the laser exposure optical system 3, an image signal from the digital color image reader section B is converted into an optical signal in a laser output section (not shown), and the laser light converted into the optical signal is reflected by the polygon mirror 3a to form a lens. 3b
And is reflected by the mirror 3c and projected on the surface of the photosensitive drum 1.

At the time of image formation in the digital color image printer section C, the photosensitive drum 1 is rotated clockwise in FIG. 1 and the surface of the photosensitive drum 1 is neutralized by the pre-exposure lamp 11 and then charged by the corona charger 2. The surface of the photoreceptor drum 1 is uniformly charged and irradiated with a light image E for each of the separated colors to form an electrostatic latent image.

Next, predetermined developing units 4y, 4c, 4m, 4Bk
Is operated to supply toner of each color based on resin and pigment to the electrostatic latent image on the photosensitive drum 1 to form a toner image. The developing units 4y, 4c, 4m and 4Bk are eccentric cams 24y and 24b.
The operation of c, 24m, and 24Bk is such that the photosensitive drum 1 is selectively approached in accordance with each color separation.

On the other hand, sheets P made of paper, synthetic resin or the like stored in the sheet cassettes 7a, 7b, 7c are separated and fed one by one by various sheet feeding means and sheet conveying means, and the registration rollers are paired. 18, the skew of the sheet P is corrected by the registration roller pair 18, and then the photosensitive drum 1 is transferred via a transfer device 5 serving as a transfer unit.
The toner image on the photosensitive drum 1 is transferred to the sheet P by the operation of the transfer device 5.

The transfer device 5 includes a transfer drum 5a, a transfer charger 5b, and an attraction charger 5c for electrostatically attracting the sheet P.
5g, an inner charging device 5d, an outer charging device 5e, and the like, which are opposed to the transfer roller 5a. A support sheet 5f made of a dielectric sheet such as a polycarbonate film is integrally stretched in a cylindrical shape.

The toner image on the photosensitive drum 1 is transferred onto the sheet P carried on the carrier sheet 5f by the transfer charger 5b as the transfer drum 5a adsorbing the sheet P on the carrier sheet 5f is rotated. Thus, a desired number of color images are transferred to the sheet P conveyed by being electrostatically attracted to the supporting sheet 5f, and a full-color image is formed.

In the case of forming a full-color image, when the transfer of the four color toner images is completed in this manner, the separation claws 8a,
After the sheet P is separated from the transfer drum 5a by the action of the separation push-up roller 8b and the separation charger 5h, the toner image is heated and pressure-fixed to the sheet P by the heat roller fixing device 9 serving as a fixing unit, and then discharged. Exhausted on 10.

On the other hand, after the image is transferred, the photosensitive drum 1 is cleaned by a cleaning device 6 to remove residual toner on the surface.
It is subjected to the next image forming step.

When an image is formed on both sides of the sheet P, the sheet P passes through the heat roller fixing device 9 and then immediately drives the conveyance path switching guide 19 to temporarily move the sheet P through the conveyance vertical path 20. After being guided to the reversing path 21a, the sheet P is retreated in a direction opposite to the direction in which the sheet P was fed by the reverse rotation of the pair of reversing rollers 21b, with the rear end of the sheet P leading.
It is guided by the flapper means 23 and temporarily stored in the intermediate tray 22. Thereafter, an image is formed on the other surface again by the above-described image forming step.

In order to prevent the powder such as toner from being scattered and adhered on the carrier sheet 5f of the transfer drum 5a, the fur brush 14 and the carrier sheet 5f intervene through the fur brush 14 to prevent oil from adhering to the sheet P. The cleaning is performed by the backup brush 15 facing the oil removal roller 16 and the backup brush 17 facing the oil removal roller 16 via the oil removal roller 16 and the supporting sheet 5f. Such cleaning is performed before or after image formation, and is performed at any time when the sheet P is jammed.

In the present embodiment, the eccentric cam 25 is operated at a desired timing and the cam follower 5i integrated with the transfer drum 5a is operated to arbitrarily set the gap between the supporting sheet 5f and the photosensitive drum 1. For example, the interval between the transfer drum 5a and the photosensitive drum 1 is increased during standby or when the power is turned off.

Next, referring to FIGS. 1 to 3, a curling portion 31 for the sheet P in the main body A of the full-color image forming apparatus will be described.
Will be described. As shown in FIG. 1, the curling unit 31 is located upstream of the image transfer position between the photosensitive drum 1 serving as an image forming unit and the transfer drum 5a serving as a transfer unit in the sheet conveyance direction (hereinafter simply referred to as “upstream side”). As shown in FIG. 2, there is provided a curl applying means in which two curling rollers 31b and 31c are pressed against one driving roller 31a provided on a conveying path for conveying the sheet P. are doing.

The sheet P being conveyed is driven by the drive roller 31.
When the sheet P passes between a and the curling rollers 31b, 31c, the sheet P is flattened downward by the rollers 31a, 31b, 31c in FIG.

Since the sheet P is squeezed together with this curling operation, the sheet P is charged with frictional static electricity after passing through the curling roller 31b, so that the sheet P is located downstream of the curling roller 31b. The sheet is conveyed in a state in which it is very easy to stick to the guide surfaces of the upper and lower conveyance guides 32a and 32b serving as sheet conveyance means. This phenomenon is particularly noticeable in a dry environment.

In the present embodiment, the upper and lower transport guides 32
The interval between a and 32b is large enough not to return the curl formed in the curling portion 31, and the sheet P is stuck to the guide surfaces of the transport guides 32a and 32b. In such a case, the conveyance force of the drive roller 31a and the curling rollers 31b and 31c is hardly transmitted to the sheet P, so that the sheet P is liable to be skewed or to be delayed.

Therefore, in the present embodiment, as shown in FIG. 3, a charge for removing the charge on the sheet P near the downstream side of the curl applying means constituted by the driving roller 31a and the curling rollers 31b and 31c is used. Remove the static elimination member 33 from the apparatus main body A
The sheet P having passed through the curling roller 31b is electrically connected to the sheet P, and the charge on the sheet P is dropped to the ground via the charge removing member 33 to remove the charge, thereby removing the downstream conveyance guide.
The sheet P is configured to prevent sticking of the sheet P to 32a and 32b.

Thus, the static electricity generated on the sheet P due to the squeezing of the driving roller 31a and the curling rollers 31b and 31c serving as the curl applying means is removed by the charge eliminating member 33, and the sheet P is adhered to the conveyance guides 32a and 32b of the sheet P. As a result, it is possible to prevent the occurrence of skewing or a jam due to a conveyance delay.

Further, since the distance between the transport guides 32a and 32b can be set wide, the sheet P can be transported stably while maintaining the curling effect.

The discharging member 33 is configured to move the sheet P after passing through the curling roller 31b on the downstream side in the sheet conveying direction (hereinafter, referred to as the sheet P).
Before or after contact with the transport guides 32a and 32b (hereinafter simply referred to as "downstream"), the area downstream of the curl applying means is set so that the area is not large enough to cause sticking due to charging. It is preferable to arrange it near.

The static elimination member 33 according to the present embodiment employs a static elimination cloth which is a sheet-like member disposed in the vicinity of the sheet P which is in contact with or passes through the sheet P and is spaced from the sheet P by about 3 mm to 5 mm. The discharging member 33 is electrically connected to the apparatus main body A and grounded.

As a result, the durability is improved as compared with a thin metal needle-shaped member, and the charge removing member is conveyed by conveying the sheet P or the like.
Even if 33 is cut, other parts such as the photosensitive drum 1, the transfer drum 5a or the heat roller fixing device 9 are not damaged.

FIGS. 4A and 4B are views showing an example of a skew state when 50 sheets of A4 size plain paper are continuously fed horizontally. The vertical axis in FIG. 4A indicates the positional deviation (unit: mm) between the front end and the rear end at one side end of the sheet P in the conveying direction, and the horizontal axis indicates the number of sheets P. FIG. 4 (b)
The vertical axis indicates the positional deviation (unit: mm) between the front end and the rear end at one side end of the sheet P in the conveying direction, and the horizontal axis indicates the number of the feeding order of the sheet P which has been continuously fed 50 times continuously. .

Since the sheet P is neutralized by the neutralizing member 33, the sheet P does not stick to the transport guides 32a and 32b, and as shown in FIGS. It can be seen that the skew has almost completely disappeared. In the above configuration, the curl amount (height) of the sheet when the A3 size thick paper is passed is as shown in Table 3 below.

[0048]

[Table 3]

As can be seen from the comparison with Tables 1 and 2 shown in the above-mentioned conventional example, the curl amount does not decrease as shown in Table 2 in which the gap between the pair of conveyance guides is reduced. It is possible to maintain a degree of curl.

A so-called sponge roller in which a hard small-diameter roller is pressed against a soft large-diameter roller instead of a roller pair type using one driving roller 31a and two curling rollers 31b and 31c as a curling means. In the case of the type of curl applying means, the charging of triboelectricity generated by the ironing of the sheet P is the same.
Stable sheet P that can prevent sticking to 32a and 32b
Can be transported.

In this embodiment, as shown in FIG. 3, the static elimination member 33 is contacted from the lower side (non-image side) of the sheet P to eliminate static electricity, but from the upper side of the sheet P (image side). Even if the charge removing member 33 is configured to be in contact, the charge removing effect is substantially the same, and thus may be appropriately selected and used according to individual design conditions.

Next, a second embodiment of the image forming apparatus provided with the sheet conveying device according to the present invention will be described with reference to FIG. FIG. 5 is a schematic circuit diagram showing an arrangement of electric resistance members in the second embodiment of the image forming apparatus provided with the sheet conveying device according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the present embodiment, the static elimination member 33 is the device main body A.
(Ground) via an electric resistance member 41 having an electric resistance value of 100 MΩ. The electric resistance value of the electric resistance member 41 is constituted by a driving roller 31a and curling rollers 31b and 31c. Electricity of each member capable of contacting the sheet P on the conveyance path from the curl applying means to the image transfer position between the photosensitive drum 1 serving as the image forming means and the transfer drum 5a serving as the transfer means, with respect to the apparatus main body A It is configured to be larger than the resistance value.

Particularly in a high humidity environment or the like, a high voltage current when the sheet P is attracted to the transfer drum 5a or a high voltage current when transferring an image passes through the sheet P, and the sheet P such as a transport guide or a transport unit upstream of the transfer drum 5a. In this embodiment, there is a possibility that the sheet P may flow to a member that can come into contact with the sheet P, and a defective suction of the sheet P or a defective transfer of an image may occur. The unit 42 is electrically connected to the apparatus main body A (ground) via an electric resistance member 43 having an electric resistance value of 20 MΩ.

Here, the reason why the suction unit 42 is not completely electrically floated so that a high voltage current does not flow when the sheet P is suctioned or an image is transferred is that the suction unit 42 itself is charged and generates discharge noise. This is to prevent it. By setting the electric resistance value of the electric resistance member 43 to about 20 MΩ, it is possible to prevent the occurrence of discharge noise and to prevent the high-voltage current at the time of adsorbing the sheet P and transferring the image to the apparatus main body A. .

A conveyance guide 32 disposed between the suction unit 42 and the curling unit 31 on the conveyance path of the sheet P.
As for a and 32b, an electrically insulating coating is applied to the passage surface side of the sheet P to prevent high voltage current from flowing through the sheet P, and the transport guides 32a and 32b themselves are electrically connected to the apparatus main body A. And connected to the ground.

Various transport rollers such as a pair of pre-registration rollers 34 and a pair of registration rollers 18 disposed downstream of the transport guides 32a and 32b are composed of a pair of an electrically insulating resin roller and a rubber roller. This prevents a high-voltage current from flowing through the sheet P from these various transport rollers.

When transferring the image to the sheet P and adsorbing the sheet P to the transfer drum 5a, the sheet P may still be in contact with the charge removing member 33 depending on the size of the sheet P (when it is long in the transport direction). . For this reason, if the static elimination member 33 is directly connected to the apparatus main body A and directly grounded, the high-voltage current flows from the sheet P through the static elimination member 33 to the apparatus main body A, and the above-described defective adsorption of the sheet P and the like. There is a possibility that image transfer failure may occur.

Therefore, in the present embodiment, as shown in FIG. 5, the electric resistance value of the electric resistance member 43 electrically connected between the suction unit 42 and the apparatus main body A downstream of the charge removing member 33 is determined. An electrical resistance member 41 having a large electrical resistance value is electrically connected between the static elimination member 33 and the apparatus main body A to be grounded.

By setting the electric resistance member 41 to about 100 MΩ, the electric discharge member 33 is dropped to the ground with a higher electric resistance value than the suction unit 42 downstream of the electric discharge member 33, so that a high voltage current flows from the electric discharge member 33. In addition, the electric charge generated when the sheet P is discharged can be reliably released to the ground.

The other structure is the same as that of the first embodiment, and can obtain the same effect.

In each of the above embodiments, the case where the present invention is applied to the curl applying means for curling the sheet P has been described, but the present invention is similarly applied to the curl removing means for removing the curl formed on the sheet P. Can be done.

[0063]

Since the present invention has the above-described configuration and operation, the sheet is removed by the curl removing means and the curl applying means by the neutralizing member provided near the downstream side in the sheet conveying direction of the curl removing means and the curl applying means. Elimination of generated frictional static electricity can prevent skew due to sticking of the sheet and occurrence of jam etc. due to transport delay, impairing sheet curl removal by curl removing means and curling of sheet by curl applying means. There is no.

When the charge removing member is formed of a sheet-like member arranged in the vicinity of a sheet that comes into contact with or passes through the sheet, the durability performance is improved as compared with a thin metal needle-like member. Even if the static elimination member is cut off due to sheet conveyance or the like, no damage is caused to other components.

Also, each of the members that can come into contact with the sheet on the conveyance path from the curl removing unit or the curl applying unit to the image transfer position via an electric resistance member having an electric resistance larger than the electric resistance of the apparatus main body. When the static elimination member is electrically connected to the apparatus main body, it is possible to prevent a high voltage current at the time of image transfer or attraction of the sheet to the transfer unit from escaping from the static elimination member via the sheet. It is possible to stably curl the sheet while maintaining the image forming state.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view illustrating a configuration of an image forming apparatus including a sheet conveying device according to the present invention.

FIG. 2 is an explanatory cross-sectional view illustrating a configuration of a curl applying unit provided in the sheet conveying apparatus according to the present invention.

FIG. 3 is an explanatory cross-sectional view illustrating a configuration around a curl applying unit and a charge removing member provided in the sheet conveying apparatus according to the present invention.

FIGS. 4A and 4B are diagrams illustrating an example of a skew amount when 50 sheets of A4 size plain paper are continuously fed horizontally.

FIG. 5 is a schematic circuit diagram illustrating an arrangement of electric resistance members in an image forming apparatus including a sheet conveying device according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a problem of a conventional example.

FIG. 7 is a diagram illustrating a problem of a conventional example.

[Explanation of symbols]

A: Full-color image forming apparatus main body, B: Digital color image reader unit, C: Digital color image printer unit, D
... Original, E ... Light image, P ... Sheet, 1 ... Photoconductor drum, 2
... Corona charger, 3 ... Laser exposure optical system, 3a ... Polygon mirror, 3b ... Lens, 3c ... Mirror, 4y, 4c,
4m, 4Bk developing device, 5 transfer device, 5a transfer drum, 5b transfer charger, 5c adsorption charger, 5d inner charger, 5e outer charger, 5f support sheet, 5g
Suction roller, 5h: Separate charger, 5i: Cam follower,
6 cleaning device, 7a, 7b, 7c sheet cassette, 8a separation claw, 8b separation push-up roller, 9 heat roller fixing device, 10 discharge tray, 11 pre-exposure lamp, 12
Potential sensor, 13 ... Light amount detection means, 14 ... Fur brush, 15
... back-up brush, 16 ... oil removal roller, 17 ... back-up brush, 18 ... registration roller pair, 19 ... conveyance path switching guide, 20 ... conveyance vertical path, 21a ... reverse path,
21b: reverse roller pair, 22: intermediate tray, 23: flapper means, 24y, 24c, 24m, 24Bk: eccentric cam, 25: eccentric cam, 26: platen glass, 27: exposure lamp, 28: lens,
29: full-color CCD sensor, 31: curling part, 31a
... Driving roller, 31b, 31c ... Curling roller, 32a,
32b: conveyance guide, 33: static elimination member, 34: roller pair before registration, 41: electric resistance member, 42: suction unit, 43: electric resistance member

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hisakazu Okubo 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc. 3F053 HA03 HA08 HB01 LA02 LA05 LA07 LB03 3F101 AA01 AA13 LA02 LA05 LA07 LB03

Claims (5)

[Claims] An electric charge charged on a sheet near a downstream side in a sheet conveying direction of a curl removing unit that removes curl formed on a sheet or a curl applying unit that curls a sheet, which is disposed on a conveying path that conveys the sheet. A sheet conveying device provided with a charge removing member for removing the sheet. 2. The sheet conveying apparatus according to claim 1, wherein the static elimination member is formed of a sheet-like member arranged near a sheet that contacts or passes through the sheet. 3. The sheet conveying device according to claim 1, wherein the static elimination member is electrically connected to the apparatus main body via an electric resistance member having a predetermined electric resistance value. apparatus. 4. A sheet conveying device according to claim 1, an image forming unit for forming a toner image according to image information, and a sheet for forming the toner image on the image forming unit. And a curl removing unit or a curl applying unit, and the charge removing member is provided on an upstream side in a sheet conveying direction from an image transfer position between the image forming unit and the transfer unit. An image forming apparatus comprising: 5. An electric resistance value of the electric resistance member is larger than an electric resistance value of each member capable of contacting a sheet on a conveyance path from the curl removing means or the curl applying means to the image transfer position with respect to the apparatus main body. The image forming apparatus according to claim 4, wherein: