JPH04164753A - Sheet material feeding device - Google Patents

Abstract

PURPOSE:To convey a sheet material accurately without oblique feeding an the like by setting a sheet material pressure for a one-side conveyance reference guide of the first contact pressure means on upstream side to an equal or less value to or than that of the second contact pressure means on the downstream side. CONSTITUTION:In the reversing and conveying process of a sheet material along the outer surface of the carrier roller 27, in the sheet material P, the side edge Pa of the sheet material P on the conveyance reference side is made to come into uniform contact with the side conveyance reference guide 33 by the sheet material feeding action through the first and second contact pressure means 25 and 26 (sheet material pressure feed action in the direction of a one-side conveyance reference guide 33). After the side edge Pa of the sheet material P is to come into uniform contact with the guide 33, too, the sheet material oblique feed action of the first and second contact pressure means 25 and 26 is applied to the sheet material P, so that it is reversed and conveyed along the guide 33 and the outer surface of the carrier roller 27 while a uniform contacting condition of the side edge Pa with the guide 33 is being kept. It is thus possible to reverse and convey the sheet material P properly at all time without oblique feed and the like.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to image forming apparatuses such as copying machines, printers, facsimile machines, and word processors, as well as various other types of sheet material handling equipment. One sheet of sheet material (transfer paper, photosensitive paper, electrostatic recording paper, photosensitive paper, printing paper, printing paper, OHP sheet, envelope, postcard, sheet original, etc.) is sent out from the storage section to the image forming section on a one-sided feeding basis.・
The present invention relates to a sheet material feeding device that feeds and conveys sheet material to a sheet material receiving section such as an exposure section and a processing section.

(Prior Art) For convenience, a laser beam printer recording apparatus using electrophotographic recording, which is schematically shown in FIGS. 7(A), 7(B), and 7(C), will be described as an example.

In Figures 7 (A), (B), and (C), the sheet path (sheet material conveyance path) from the sheet material storage section to the sheet material discharge section is a straight type, a 0-character type, and a 5-character type, respectively. It shows a certain device.

The device shown in the figure, which is a sheet path or straight type (^), has a paper feed cassette insertion slot 51 on one side of the main body 50 and a sheet material discharge port 62 on the other side. A paper feed cassette 52 as a sheet material accommodating section is attached to 51, and a paper discharge tray 63 is attached to the paper discharge port 62 so as to protrude outward.

The paper feed roller 53 is rotationally driven by the paper feed signal and feeds the topmost recording paper of the stacked recording paper (recording medium) P as a storage sheet material in the paper supply cassette 52, and the separating claw 54 and With the cooperation of the two, the topmost recording sheet is separated and sent into the apparatus.

The recording paper is sent out through a path between guide plates 55 and 56 → pair of registration rollers 57 → image transfer section 58 → transport belt device 59 → image fixing device 60 → paper discharge roller 61 → paper discharge port 62 (
The sheet passes through a sheet path and is discharged onto a paper discharge tray 63 as an image-formed product (print).

Reference numeral 64 denotes a drum-type electrophotographic photoreceptor (hereinafter referred to as photoreceptor drum) which is rotated clockwise around a central support shaft at a predetermined circumferential speed (process speed). It is equipped with a photoreceptor mainly composed of an inorganic photoconductor layer. 65 is a charger that uniformly charges the outer peripheral surface of the photosensitive drum to a predetermined polarity and potential;
Reference numeral 6a denotes a laser beam scanner and a beam reflector for writing target image information onto the surface of the charged photosensitive drum 5 and scanning and exposing it. Reference numeral 67 denotes a developer for developing an electrostatic latent image on the photosensitive drum surface formed by scanning exposure with toner. , 68 is a transfer roller serving as a transfer means for transferring the toner image carried on the photosensitive drum surface side to the recording paper P, and 69 is a cleaning device for cleaning the photosensitive drum surface after the image has been transferred. Since the process and principle of image formation is well known, the explanation thereof will be omitted. Further, in the apparatus of this embodiment, four process devices including a photosensitive tram 64, a charging device 65, a developing device 67, and a cleaning device 69 are collectively assembled into a process cartridge 70 which is detachably mountable to the main body of the device.

In this apparatus, the sheet path from the paper feed cassette 52, which is a sheet material storage section, to the paper discharge tray 63, which is a sheet material discharge section, is almost straight, and the reliability of sheet material conveyance is good. However, the paper feed cassette 52 as a sheet material accommodating section and the paper ejection tray 63 as a sheet material ejecting section, which protrude outward on one side and the other side of the device, respectively, are added to the installation space of the device. This substantially increased the installation space for the device.

Therefore, in order to reduce the actual footprint of the device (
Many device configurations have come to be used, such as the devices shown in Figures B) and (C), which have a 0-shaped or 5-shaped sheet path with a bent sheet path.

The device shown in Figure (B), which is a sheet path or 0-character type, has a paper feed cassette insertion port 51 and a paper ejection port 62 on one side of the device, and almost the entire paper feed cassette 52 as a sheet material storage section. is inserted into the main body of the apparatus, and the recording paper P fed from the cassette by the paper feed roller 53 is transferred to the reversing guide 71.
cassette 52 with a and 71b and transport rollers 72a and 72b.
The recording paper is conveyed upward in a U-turn in the opposite direction to the feeding direction of the recording paper from the cassette, and the image transfer section 58 → the conveyance held device 59 → the image fixing device 60 → the paper ejection roller 61 → the paper ejection port 6.
2, the paper is ejected onto the ejection tray 63, and the only protruding member to the outside of the device is the ejection tray 63.
A) The installation area of the device is smaller than that of the device shown in the figure.

The device in figure (G), which is either seat pass or 5-character type, is (B
) In the apparatus shown in the figure, the recording paper that has come out of the paper ejection roller 61 is directed toward the top plate of the apparatus, and is again conveyed in a U-turn by the reversing guide 73, and then the second paper ejection roller 74 makes a paper ejection tray using the top plate of the apparatus. 75, there is no need for a projecting member to the outside of the device, and the installation area of the device is further reduced compared to the device shown in FIG.

(Problem to be solved by the invention) By bending the sheet path into a U-shape or 5-shape as shown in Figures (B) and (C), the installation area of the equipment can be reduced, but on the other hand, the height of the equipment is reduced. The sheet path tends to be larger than that of the device shown in FIG. Therefore, attempts have been made to reduce as much as possible the radius of the equivalent circular arc by which the sheet material is folded and reversed at the U-shaped or 5-shaped sheet material reversal section.

However, if the radius of the circular arc to be reversed is made small, for example, at the reversing section C in FIG. 7(B), the reversing guide 71a and
There was a possibility that the sheet material would become tight or sag in the gap between the holes 71b and 71b, resulting in poor reliability.

Further, in an image forming apparatus, if a sheet material such as a recording paper is not correctly fed into a recording section within the image forming apparatus, image distortion may occur.

Therefore, the sheet material is conveyed while pressing the side (edge/end surface of the sheet material) on the one side conveyance reference side of the sheet material against the sheet material one side conveyance reference guide of the image forming apparatus main body using the oblique feed roller. A conveying method has been proposed to prevent skew from occurring, but as mentioned above, if the radius of the arc for reversing the sheet material is made small, the conveyance load of the reversing guide on the non-reference side will cause the first skew to the roller. Due to this, skew feeding occurred, and the side part of the one-sided conveyance standard of the sheet material was sometimes damaged.

Therefore, in view of the above points, the present invention has a relatively simple configuration and conveys the sheet material to be fed to one side conveyance reference plane while pressing the side of the conveyance reference side, thereby accurately eliminating skewing etc. Even when a relatively small arc radius is set for sheet material reversal,
It is an object of the present invention to provide a sheet material feeding device capable of feeding and conveying sheet materials without causing skew feeding of the sheet materials or damaging the side portions of the sheet materials on the conveyance reference side.

(Means for Solving the Problems) The present invention includes: a sheet material storage section; a paper feeding means for feeding sheet materials from the sheet material storage section to one sheet; and a one-sided conveyance standard for the sheet material sent from the sheet material storage section. a guide; a conveyance roller that conveys the sheet material in contact with a side portion of the one-side conveyance reference side of the sheet material sent out from the sheet material storage section; The conveyor rollers are arranged sequentially on the side, and sandwich the side portion of the one side conveyance reference side of the sheet material to be sent out between the conveyance roller and press the sheet material against the one side conveyance reference guide, and move the sheet material along the guide with the conveyance roller. and at least two first and second press-contact means for conveying the sheet material in cooperation with each other. This sheet material feeding device is characterized in that it is set to be equal to or smaller than that of the pressure contact means.

Further, the present invention relates to the sheet material feeding device as described above,
The first and second pressure contact means are sheet material skew feeding rollers, and the skew feeding angle of the sheet material skew feeding roller as the first pressure contact means is changed from the skew feeding angle of the sheet material skew feeding roller as the second pressure contact means. A sheet material feeder characterized in that the sheet material pressing force of the first pressing means against the one-sided conveyance reference guide is set to be equal to or smaller than that of the second pressing means by setting the sheet material pressing force to be equal to or smaller than the corner. It is a sending device.

(Function) The sheet material fed out one sheet from the sheet material accommodating section by the paper feeding means is sandwiched between the side portion on the one-side transport reference side or between the Wl transport roller and the first pressure contact means, and is further interposed between the transport roller and the first pressure contact means. Second
It is sandwiched between the pressure contact means and the transport roller and is reversely transported along the outer periphery of the transport port and the roller by cooperation of the transport roller and the first and second pressure contact means. During the reversal conveyance process of the sheet material along the outer peripheral surface of the Fj feed roller, the sheet material is skewed by the sheet material diagonal feeding action (sheet material pressing and moving action in the direction of the one-sided transport reference guide) by the first and second pressure contact means. The side of the conveyance reference side of is in uniform contact with one side of the conveyance reference kite.

- Even after the side edges of the sheet material are in uniform contact with the guide, the sheet material is subjected to the oblique feeding action of the first and second pressure contact means to maintain the uniform contact state of the side edges with the kite. While hanging, it is reversely conveyed along the kite and along the outer peripheral surface of the conveyance roller. Therefore, the sheet material is always accurately reversed and conveyed without any skew or the like.

At least two sheet material pressure contact means for the conveyance roller shall be arranged sequentially from the upstream side to the downstream side in the sheet material conveyance direction, and the sheet material pressing force of the first pressure contact means on the upstream side against the one-sided conveyance reference kite will be By setting it to be equal to or smaller than that of the second pressure contact means on the side, the sheet material oblique feeding action toward the one-side transport reference kite on the transport sheet material can be easily and smoothly performed. Therefore, damage caused by excessive contact interference of the side portions of the sheet material with the guide is prevented.

The arc radius of the reversal conveyance of the sheet material is precisely defined by the diameter of the conveyance roller, and even when a relatively small arc radius is set, the sheet material is firmly sandwiched between the conveyance roller and the first and second pressing means. The sheet material is reversely conveyed along the outer peripheral surface of the conveyance roller, and the side edges of the sheet material are pressed against the one-sided reference guide by the sheet material oblique feeding action of the first and second pressing means, so that the sheet material is not skewed or conveyed. Even highly rigid sheet materials such as cardboard can always be smoothly and reliably conveyed without damaging the side portions of the sheet material.

Furthermore, since the reversal conveyance of the sheet material is carried out by one roller, it is relatively inexpensive and the conveyance speed is accurate (Example) Fig. 1 is an example of a laser beam printer recording device using the sheet material feeding device according to the present invention. FIG. FIG. 2 shows a perspective view of a reversing conveyance portion of a recording material as a sheet material.

Components and parts common to the apparatus shown in FIG. 7 will be designated by the same reference numerals and will not be described again.

A paper feed cassette 52 serving as a sheet material storage section is located in the main body 5 of the apparatus.
Almost the whole of the device is inserted into the main body of the device through an insertion port 51 opened at the lower part of the right side surface of the device.

The paper feed cassette 52 includes a cassette housing 20 and a pressure spring 24.
the intermediate plate 23 lifted and energized by the sheet material separating claw 54;
It has an end face regulating member 22 (FIG. 2) that guides one end face (side) of the J self-recording paper P as a storage sheet material. Recording papers P are stacked and stored in this cassette.

The recording paper P loaded in the paper feed cassette 52 is transferred to the paper feed roller 5.
3, a conveying force is applied to only the uppermost sheet of the stacked recording sheets to the upper right in FIG. 1, and only the uppermost sheet is separated by the separating claw 54 and conveyed to the right A. At this time, middle plate 2
3 and the pressure spring 24, the recording paper P and the paper feed roller 5 are
A predetermined pressing force is applied between the

The separated and fed recording paper P is conveyed upward along the upward kite 20a of the paper feed cassette (~52), and is then conveyed to the conveyance roller 27 and the first oblique conveyance roller 2 as the first pressure contact means.
5, the recording paper P is conveyed in synchronization with the rotational speed from a drive source (not shown), and is conveyed along the reversing guide 31 between the conveyance roller 27 and a second oblique conveyance roller serving as a second pressing means. 26, the recording paper P from the cassette 52
A U-turn is made to the left B, which is the opposite direction to the sending A, and the paper is reversely conveyed. Then, the recording paper P that is reversely conveyed passes through the path of guide plate 32 → image transfer section 58 → guide plate 75 → image fixing device 60 → paper discharge roller 61 → paper discharge port 62, and is provided on the left side of the main body 50 of the apparatus. The paper is output onto the discharge tray 63.

The toner image is transferred from the surface of the photosensitive drum 64 to the recording paper P by charging the back surface of the recording paper P with a transfer roller 68 to a polarity opposite to that of the toner image. The recording paper P that has passed through the image transfer section 58 is separated from the surface of the photosensitive drum 64 by being neutralized by a separation layer static elimination needle 9 to which a potential of opposite polarity to that of the transfer roller 68 is applied.

33 (Fig. 2) is one side of the recording paper P sent out from the paper feed cassette 52! This is the i-feed reference kite, and is a member on the device main body side. The conveyance roller 27 is disposed on one side of the conveyance reference kite.

The first and second oblique feed rollers 25 and 26 are connected to the paper feed cassette 5.
3 in the direction of pressing the side Pa of the conveyance reference side of the recording paper P sent from No. 2 against the surface of this one-sided conveyance reference kite 33.
As shown in Figures (A) and (B), θ1=1°,
The first skew arm 28 (FIG. 1), the second skew arm 29, and the pressing spring 30 cooperate with each other to press against the conveying roller 27 with a predetermined pressure at a skew angle of θ2=4'.

By setting the oblique feeding angle of the oblique feeding roller 25 to be smaller than that of the second oblique feeding roller 26, the perspective view of FIG. As shown in the developed view of the reversing conveyance path, in order to avoid applying more than necessary diagonal feeding force to the recording paper P, the conveying load FH due to the frictional force between the reversing guide 31 and the leading edge of the recording paper P and the first diagonal feeding roller 25 is applied. Diagonal feed force F
Recording paper P and one-sided conveyance standard kite 3 through cooperation with SI
The reaction force FG acting during the period 3 is not large, and the sheet material is transported without damaging the side Pa on the transport reference side of the recording paper P (FIG. 5(A)).

Furthermore, when the recording paper P is conveyed and reaches the position of the second diagonal feed roller 26 as shown in FIG. A sufficient diagonal feed force FS2 is applied to the recording paper P by the second diagonal feed roller 26, and the moment force M centered on the first diagonal feed roller 25 causes the side Pa of the recording paper P on the conveyance reference side to move to the conveyance reference kite 33. You will come into contact with the animals uniformly (Figure 5 (B)
)→(C)).

After the side Pa of the recording paper P uniformly touches the conveyance reference kite 33 (FIG. 5(C)), the recording paper P is moved to the first oblique feed roller 2.
By the cooperation of the skew feeding forces FSI and FS2 of the second skew roller 26 and the second skew roller 26, the sheet is stably skew conveyed while maintaining the uniform contact state.

In addition, Δ and Δ' are the conveyance loads FH-F by the reversing kite 31.
W&
This value indicates whether a delay occurs or not.

As long as the relative relationship between the angular oblique feeding angles of the first and second feeding rollers 25 and 26 as the first and second pressure contact means is maintained, the oblique feeding angle θ of the first oblique feeding roller 25 is 0° to The oblique feed angle θ2 of the second oblique feed roller 26 can be set between 0° and 10°.

The number of oblique rollers 25 and 26 serving as pressure contact means is not limited to two, and it is also possible to use two or more rollers. It is also possible to apply the sheet material conveyance force to the oblique feed rollers 25 and 26 instead of the conveyance roller 27.

In this embodiment, the oblique feed rollers 25 and 26 are used as pressure contact means for obliquely feeding the sheet material, but as shown in FIG. It is also possible to use the conveyance roller 27A and the oblique feed rollers 25A and 26A formed with ltS.

Further, although a mold separation method was used as a means for separating one sheet of stacked sheet material, other single sheet separation methods may also be adopted.

Also, the sheet material storage section is not limited to the cassette type.
It may be a deck type, a manual feed tray or a tray, or a long sheet material wound on a roll may be sequentially cut into the required length by the operation of a cutter means, and the cut sheet material may be It may also be a sending method.

(Effects of the Invention) As explained above, by using this structure, the side of the sheet material on the conveyance reference side is pressed against the one side conveyance reference guide surface with a relatively simple configuration, and the sheet material is conveyed skewly. Even if a relatively small circular arc radius for reversal is set, the sheet material will be transported skewed or the side part of the sheet material on the reference side of the sheet material will be damaged. In addition, even highly rigid sheet materials such as cardboard can be smoothly conveyed diagonally.

Furthermore, since the sheet material is reversely conveyed using one roller, it is possible to accurately set the conveyance speed at a relatively low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus using a sheet material feeding device according to the present invention. FIG. 2 is a perspective view of the sheet material reversal conveyance section. FIGS. 3(A) and 3(B) are a front view and a plan view of the conveyance roller and the oblique feed roller, respectively. FIG. 4 is a perspective view of the conveyance roller and oblique feed roller portion. FIGS. 5A, 5B, and 5C are development views of the conveyance path showing the conveyance process of the sheet material in the sheet material reversal conveyance section, respectively. FIG. 6 is a perspective view of a conveyance roller or oblique feed roller with a spiral pattern formed on its outer circumferential surface. FIGS. 7(^), (B), and (C) are schematic configuration diagrams of an example of an image forming apparatus in which the seat bus is of a straight type, a 0-character type, and a 5-character type, respectively. 52 is a paper feed cassette as a sheet material storage unit, P is a recording paper as a sheet material, 53 is a paper feed roller, 27 is a conveyance roller, 25 and 26 are oblique feed rollers as first and second pressure contact means, 31 is a reversing kite, and 33 is a one-sided conveyance standard guide. Patent applicant Canon Co., Ltd. Figure 4Δ

Claims (2)

[Claims] (1) A sheet material accommodating section, a paper feeding means for feeding out the sheet material from the sheet material accommodating section one by one, a one-sided conveyance reference guide for the sheet material being sent out from the sheet material accommodating section, and a sheet being sent out from the sheet material accommodating section. A conveyance roller that conveys the sheet material in contact with a side portion on the reference side of one conveyance of the material; At least two second rollers are configured to sandwich the side portion of the one-side conveyance reference side of the sheet material between them, press the sheet material against the one-side conveyance reference guide, and convey the sheet material along the guide in cooperation with the conveyance roller. 1 and a second pressing means, and the sheet material pressing force of the first pressing means on the upstream side against the one-sided conveyance reference guide is set to be equal to or smaller than that of the second pressing means on the downstream side. A sheet material feeding device characterized by the following. (2) The first and second pressure contact means are sheet material skew feeding rollers, and the skew feeding angle of the sheet material skew feeding roller as the first pressure contact means is the sheet material skew feeding roller as the second pressure contact means. The first skew feed angle should be set equal to or smaller than the skew feed angle.
2. The sheet material feeding device according to claim 1, wherein the pressing force of the sheet material against the one-sided conveyance reference guide of the pressure contact means is set to be equal to or smaller than that of the second pressure contact means.