JPH0524680Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Field of invention]

The present invention relates to a sheet feeding device, and more particularly to a roller assembly having a scraping roller.

[Conventional technology]

Conventionally, rotating rollers have often been used in sheet feeding devices. This principle is based on a pair of rotatably supported rollers, one of which is a drive roller,
The other roller is used as a pressure roller, and the sheet is fed by sandwiching the sheet between its contact portions. However, since the sheet may stick to one of the rollers and be rolled up, causing a sheet jam or the like, a sheet peeling means is provided. Such a sheet feeding device can be divided into two systems. The first method uses the elasticity of the sheet to feed the sheet, and an example is shown in FIG. 6a. In this,
The lower roller 50 has two drive rollers 52 with the same diameter.
a and 52b, and three sheet feed rollers 53a, 53b, and 53c, each having the same diameter and having a slightly larger diameter than these drive rollers, and these drive shafts are rotatably supported by a support mechanism (not shown). 51. Further, the upper roller 54 has two driven rollers 56a and 56b having the same diameter as the drive rollers 52a and 52b,
Four sheet feed rollers 57a, 57b, which have the same diameter as the sheet feed rollers 53a, 53b, and 53c;
57c and 57d, which are rotatably supported by a support mechanism (not shown).
It is fixed to 5. The driven rollers 56a and 56b are in pressure contact with the drive rollers 52a and 52b, and the drive shaft 51
However, when the lower roller 50 is rotationally driven by a drive motor (not shown) via a power transmission mechanism (not shown), rotational force is transmitted from the drive rollers 52a and 52b to the driven rollers 56a and 56b,
Upper roller 54 rotates. Sheet feed rollers 53a, 53b and 53c
The sheet feeding rollers 57a, 57b, 57c, and 57d are arranged alternately in the direction in which the shafts 51 and 55 extend, so that they do not contact each other. The sheet is transported by sheet feeding rollers 53a, 53b and 53c, and sheet feeding rollers 57a, 57.
b, 57c and 57d. FIG. 6b is a front view of the sheet feeding device of FIG. 6a viewed from the sheet feeding direction. PA is the sheet that is sent. That is, sheet feed rollers 53a, 53b, 53c, 57a, 57b, 57
c and 57d have slightly larger diameters than the drive rollers 52a, 52b and the driven rollers 56a, 56b, so their heights overlap. When the sheet PA is fed in during this time, the sheet PA is deformed into a wave shape by each of the sheet feed rollers, but its elasticity maintains contact pressure against each of the sheet feed rollers, so the sheet
PA will be sent. Also, a sheet transformed into a corrugated shape
Since PA has rigidity in the direction of rotation of the sheet feed rollers, it is easily peeled off without being wrapped around the rollers. The second method is to scrape off the edge of the sheet.
An example is shown in Figure 7a. In this case, the lower roller 60 includes three driving rollers 62a and 62 having the same diameter.
b and 62c, and two scraping rollers 63a and 63b having serrated side peripheral surfaces, and are fixed to a drive shaft 61 rotatably supported by a support mechanism (not shown). Further, the upper roller 64 includes three pressure rollers 66a, 66b and 6 having the same diameter as the drive rollers 62a, 62b and 62c.
6c, and is fixed to a driven shaft 65 that is rotatably supported by a support mechanism (not shown). The scraping rollers 63a and 63b have the same shape, and when the lower roller 60 is viewed from the end of the shaft 61, the serrated teeth on the side circumferential surface are similar to the driving roller 6.
2a, 62b, and 62c. The pressure rollers 66a, 66b, and 66c are in pressure contact with the drive rollers 62a, 62b, and 62c, and when the drive shaft 61 is rotationally driven by a drive motor (not shown) via a power transmission mechanism (not shown), Drive rollers 62a, 62b and 62c
Rotational force is transmitted from the pressure rollers 66a, 66b, and 66c, and the upper roller 64 rotates. The sheet is driven by drive rollers 62a, 62b and 6
2c, and pressure rollers 66a, 66b and 66c.
sent between. FIG. 7b is a side view of the scraping roller 63a of the sheet feeding device shown in FIG. 7a, viewed from the end side of the drive shaft 61. PA is the sheet that is sent.
Sheet PA has drive rollers 62a, 62b and 62c and pressure rollers 66a, 66b and 66.
When the rear end passes between them, the scraping feed rollers 63a, 63
Since the trailing edge of the sheet is scraped off by the serrated teeth on the side peripheral surface of b, it does not wrap around the drive rollers 62a, 62b and 62c. By the way, in any of the above-mentioned sheet feeding devices, the upper roller and the lower roller must be constituted by a plurality of divided narrow rollers due to their mechanism. Furthermore, in the sheet feeding device shown in FIG. 6a, divided small rollers (sheet feeding rollers) must be arranged alternately on the upper and lower sides, and in the sheet feeding device shown in FIG. A space is required between the roller (scraping roller) and the upper roller.

[Problem that the idea aims to solve]

Therefore, when these sheet feeding devices are used as a paper ejection mechanism in, for example, a flash fixing type copying device, there is a problem that flash light leaks through the gap and harms the eyes of the operator. In order to prevent this, some of these paper ejection mechanisms are equipped with a comb-shaped light-shielding plate on the ejection side, but at least the scraping roller section with serrated teeth on the side circumferential surface prevents roller rotation. Since the gap between the upper surface of the tooth and the opposing roller changes in size, it is difficult to completely block light, and this is not a good solution. SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device that minimizes the gap between the main roller, the scraping roller, and the opposing roller, and ensures sheet separation.

[Means to solve the problem]

The present invention provides at least one trunk roller 35a to 35 having a cylindrical peripheral surface and disposed on the same axis.
c, and scraping rollers 36a, 36 which are arranged so that the end surfaces of the trunk roller are in contact with the shaft 34 on which the trunk roller is arranged, and which rotate together with the trunk roller.
b, and an opposing roller 31 having a cylindrical peripheral surface in contact with the peripheral surfaces of the main roller and the scraping roller. A member 361, a plurality of legs 362 that stand up radially outward from the boss-shaped member up to the height of the circumferential surface of the trunk roller, and one end of which is supported by the legs, and between the boss-shaped member A scraping roller peripheral surface member 363 that has a space and extends from the tip of the leg in a certain direction in the circumferential direction to the vicinity of the other leg, and has a sheet scraping means 364 for scraping the sheet at the other end. The boss-like member 361, the leg portion 362, and the scraping roller circumferential member 363 are integrally formed of an elastic body, and a sheet scraping member provided at the other end of the scraping roller circumferential member 363 is provided. The means 364 is configured to be higher than the circumferential surface of the trunk roller, and when it comes into contact with the opposing roller, is pushed down inward in the radial direction and is displaced to a height equal to the circumferential surface of the trunk roller. Note that symbols inside brackets indicate corresponding elements in the embodiments shown in the drawings and described later.

[Effect]

According to this, the opposing roller 31 is the main roller 3
5a to 35c and the peripheral surfaces of the scraping rollers 36a and 36b, first, the main rollers 35a to 3
There is no gap between 5c and the opposing roller 31. Next, the scraping rollers 36a and 36b are integrally constituted by a boss-shaped member 361, a leg portion 362, and a scraping roller circumferential member 363 made of an elastic body, and the roller circumferential member 363 is an integral part of the main roller circumferential surface. Since the height of the roller circumferential member 363 is
The circumferential surface of the opposing roller 31 is in contact with the circumferential surface of the opposing roller 31, and there is no gap between the two. The sheet scraping means 364 is higher than the peripheral surface of the trunk roller, but when it hits the opposing roller 31, the roller peripheral surface member 363 is pushed inward in the radial direction, so that the sheet scraping means 36
4 comes into contact with the trunk roller 30 and does not create a gap. Since the roller circumferential member 363 is an elastic body, when the sheet scraping means 364 passes through the trunk path 30, the roller circumferential member 363 is pushed outward in the radial direction and comes into contact with the opposing roller 31. Sheet scraping means 3
64 hits the rear end of the sheet and scrapes it forward.
That is, due to the elasticity of the leg portion 362 and the scraping roller circumferential member 363, one of the roller circumferential member 363 and its sheet scraping means 364 is always in contact with the opposing roller 31, so that the scraping roller 36
There is also no gap between a, 36b and the opposing roller 31. Since the scraping rollers 36a, 36b are arranged so that their end surfaces are in contact with the shaft 34 on which the trunk roller 30 is disposed, there is also a gap between the scraping rollers 36a, 36b and the trunk roller 30. There is no. As described above, according to the present invention, the sheet is not only raked and fed, but also by the main rollers 35a to 35c, the raking rollers 36a and 36b, and the opposing roller 3.
There is no gap between the three parties. Other objects and features of the invention will become apparent from the following description of embodiments shown in the drawings.

【Example】

FIG. 1 shows an outline of the mechanism of a copying apparatus according to an embodiment of the present invention. This will be explained with reference to FIG. Reference numeral 1 denotes a contact glass on which an original is set, and the original is brought into close contact with the contact glass 1 by a pressure plate 2. An optical scanning system comprising an exposure lamp 3, a first mirror 4, a second mirror 5, a third mirror 6, a condenser lens 7, a fourth mirror 8, etc. is provided below the contact glass 1. Light reflected from the original by exposure lamp 3 is guided to photoreceptor drum 9 by this optical system. The copying apparatus of this embodiment is of a document fixed type, and includes a first carriage (not shown) equipped with an exposure lamp 3, a first mirror 4, etc.;
Then, a second carriage (not shown) equipped with a second mirror 5, a third mirror 6, etc. is driven at a speed ratio of 2:1, and the document is scanned while keeping the optical path length constant. . This document scanning is performed in synchronization with the photosensitive drum 9 (clockwise in FIG. 1) rotating at a constant speed. Around the photosensitive drum 9, there are a static elimination lamp 10, a charging charger 11, an eraser 12, a developing unit 13, a transfer charger 14, a separation charger 15, and a separation claw 16.
and a cleaning unit 17. The paper feed table has two stages, and paper feed cassettes 18 and 19 are removably inserted into each paper feed table. When the first stage paper feed tray is selected, the recording sheets stored in the paper feed cassette 18 are fed out by the paper feed rollers 20 and feed rollers toward the registration rollers 22, and the second stage paper feed tray is selected. Then, the recording sheets stored in the paper feed cassette 19 are fed out toward the registration rollers 22 by the paper feed rollers 21 and the feed rollers. The registration roller 22 sends out the recording sheet to the photoreceptor drum 9 at a predetermined timing (sheet feeding). Downstream of the photosensitive drum 9,
A conveyor belt 23, a fixing unit 24, etc. are provided. 25, the recording sheet is transferred to the external paper output tray 2.
This is a pair of ejecting rollers for ejecting the paper to No. 6. An overview of the copy process will be explained. When the operator inputs a copy start instruction, charging of the photosensitive surface → electrostatic latent image formation → development → transfer →
Perform the copy process in the order of fixing. First, the photosensitive surface of the photosensitive drum 9 is uniformly charged to a high positive potential by the charging charger 11, and unnecessary areas are erased by the eraser 12 according to the recording sheet size. The optical system is energized at a predetermined timing so that the exposure of the leading edge of the original coincides with the end position of the leading edge erase, and the exposure lamp 3 illuminates the original.
Scanning is performed by the carriage and the second carriage. The reflected light of the original is reflected by the first mirror 4, the second mirror 5, and the third mirror 6, and is reflected by the lens 7.
When the light is focused, it is reflected by the fourth mirror 8 and formed into an image on the photosensitive surface of the photosensitive drum 9 . When the photosensitive surface of the photosensitive drum 9, which is uniformly charged to a high positive potential, is irradiated with the reflected light from the original, the surface charge is removed depending on the intensity of the reflected light from the original due to a photoconductive phenomenon, and the electrostatic charge is removed. A latent image is formed. Since this electrostatic latent image is formed negatively, negatively charged toner adheres to it while it passes through the developing device 13 and is visualized (developed: a positive image). Before starting exposure, load each paper cassette 18.
Alternatively, the recording sheet fed out from the registration roller 19 to the registration roller 22 is stopped once in contact with the registration roller 22, and is sent out toward the photoreceptor drum 9 at a predetermined timing according to the rotation of the photoreceptor drum 9. Ru. When the recording sheet passes directly above the transfer charger 14 to which a predetermined voltage is applied, it comes into contact with the toner image formed on the photosensitive surface of the photosensitive drum 9, and the toner image is transferred. After the toner image has been transferred, the photosensitive surface is cleaned by cleaning unit 1.
7, cleaning static electricity removal is performed to wipe away residual toner and carrier. The recording sheet onto which the toner image has been transferred is separated from the photosensitive surface of the photosensitive drum 9 by a separation charger 15 and a separation claw 16 and placed on a conveyor belt 23 with the toner image facing upward. The fixing unit 24 is a flashlight, and the toner image on the recording sheet is fixed by flash light. The recording sheet with the toner image fixed thereon is discharged onto a paper discharge tray 26 by a paper discharge roller 25 . FIG. 2 is a perspective view showing details of the paper discharge roller 25 of the copying machine shown in FIG. 1. Referring to FIG. 2, the paper discharge roller 25 is composed of an upper roller 30 and a lower roller 33. The upper roller 30 is a pressure roller 31 made of a relatively hard material and fixed to a driven shaft 32 that is rotatably instructed by an instruction mechanism (not shown). The lower roller 33 is fixed to a drive shaft 34 that is rotatably supported by a support mechanism (not shown).
Drive rollers 35a, 35b, 35c, and second
As is clear from the figure, the scraping roller 36 is disposed so that the end surface of the drive roller contacts the end surface of the drive roller.
It consists of a and 36b. The drive shaft 34 is coupled to a power transmission mechanism (not shown) that transmits the rotational force of a drive motor, but the illustration is omitted because there is no difference from a normal drive mechanism. In FIG. 2, the upper roller 30 is in pressure contact with the lower roller 33, and when the lower roller 33 is rotationally driven by the drive motor, the rotational force is transmitted from the pressing surface and the upper roller 30 rotates. Drive rollers 35a and 35b of the lower roller 33
and 35c, scraping rollers 36a and 3
The diameters of the rollers 6b are all the same, but the scraping roller 36
There are four protrusions 3 of about 1.5 mm on a and 36b.
64 (FIG. 3) is provided. A right side view of the scraping roller 36a is shown in FIG. Referring to FIG. 3, the scraping feed roller 36a
As is clear from FIG. 3 when viewed from the side, there is an inner cylinder 361 as a boss-shaped member disposed on the shaft 34, and a circumference of the main roller 35a etc. radially outward from the inner cylinder 361. A plurality of legs 362 that stand up to the height of the surface, one end of which is supported by the legs 362, and a space between the legs 362 and the inner cylinder 361, and other legs extending in a fixed direction in the circumferential direction from the tips of the legs 362. The cutout piece 363 is a peripheral surface member of the scraping roller and has a protrusion 364 as a sheet scraping means for scraping the sheet at the other end. These inner cylinder 361, leg portion 362, cutout piece 363, and protrusion 364 are integrally formed of an elastic body, and the portion consisting of the leg portion 362 and cutout piece 363 is
It serves as a bent piece of the scraping roller 36a. In FIG. 3, the scraping roller 36a rotates counterclockwise. The scraping roller 36a is made of a good elastic material (for example, a rubber material), and when a pressing force is applied to the protrusion 364, the cutout end of the bent piece (one end where the protrusion is formed) easily becomes hollow. It bends towards the end and returns to its original shape when the pressing force is released. The scraping roller 36b also has exactly the same shape and material as the roller 36a. The scraping roller 36a will be explained below. The recording sheet feeding by the above-mentioned paper ejection roller 25 will be explained with reference to FIGS. 4a and 4b. FIG. 4a shows a state in which the recording sheet PA is sandwiched, but the circumferential surface of the scraping feed roller 36a is
Since the driving rollers 35a, 35b, and 35c have the same height on their circumferential surfaces, they are in pressure contact with the pressure roller 31 without creating a gap. FIG. 4b shows the protrusion 36 of the scraping roller 36a.
4 is shown in contact with the pressure roller 31. In this case, since the pressing force of the pressure roller 31 is applied to the protrusion 364 which is higher than the circumferential surface of the scraping roller 36a, the protrusion 364 is in contact with the pressure roller 31. The cutout end of the bent piece (one end where the protrusion is molded) bends toward the hollow part, and the head of the protrusion 364 is buried at the same height as the circumferential surface of the scraping roller 36a, so that it is not connected to the pressure roller 31. No gaps are created on the contact surface. Also, when the rear end of the recording sheet PA passes between these rollers 25, the protrusion 364 of the scraping roller 36a
The rear end of the sheet is scraped off (Figure 4b)
Therefore, the recording sheet PA is attached to the drive rollers 35a, 35.
It is peeled off without wrapping around b and 35c. In the embodiment described above, the scraping roller 36a
Although 36b and 36b have four protrusions, the number of protrusions may be further increased. Alternatively, it may be a protrusion that smoothly continues with the circumferential surface. An example of this is shown in FIG. As is clear from FIG. 5, the scraping roller 36a in this example includes an inner cylinder 361 as a boss-shaped member disposed on the shaft 34, and a trunk roller 35a radially outward from the inner cylinder 361. A plurality of legs 362 that stand up to the height of the circumferential surface, one end of which is supported by the legs 362, and a space provided between the legs 362 and the inner column 361 so as to protrude away from the tip of the legs 362. A scraping roller having a scraping end 364 as a scraping means, which extends in a constant direction in the circumferential direction to the vicinity of the other leg and protrudes outward in the radial direction as it approaches the other end. It is composed of a cutout piece 363 as a peripheral surface member. This scraping roller 3 shown in FIG.
6a is made of a good elastic material such as a rubber material, similar to the one shown in FIG. The portion formed by this is a bent piece of the scraping roller 36a. This scraping feed roller 36a shown in FIG.
rotates counterclockwise in this figure. The cutout end 364 of the bent piece is elevated by about 1.5 mm from the circumferential surface of the drive roller 35a. In FIG. 5, the scraping roller 36a contacts the pressure roller (31: FIG. 2) and rotates counterclockwise, but at the contact portion, a portion 364 that is higher than the other circumferential surface of the bent piece Since the pressing force of the pressure roller 31 is applied to the hollow part, it bends toward the hollow part and is buried at the same height as the other circumferential surface. When the pressing force is released by rotation, this portion returns to its original shape.
When the trailing edge of the recording sheet passes, the notched end 364 of the bent piece scrapes off the trailing edge of the sheet.
The recording sheet does not wrap around and can be easily peeled off.

[Effect of the idea]

As described above, according to the present invention, since the opposing roller 31 is in contact with the circumferential surfaces of the trunk rollers 35a to 35c and the scraping rollers 36a and 36b, first,
There is no gap between the trunk rollers 35a to 35c and the opposing roller 31. Next, the scraping rollers 36a and 36b are integrally constituted by a boss-shaped member 361, a leg portion 362, and a scraping roller circumferential member 363 made of an elastic body, and the roller circumferential member 363 is an integral part of the main roller circumferential surface. Since the height of the roller circumferential member 363 is
The circumferential surface of the opposing roller 31 is in contact with the circumferential surface of the opposing roller 31, and there is no gap between the two. The sheet scraping feeding means 364 is higher than the circumferential surface of the main roller, but when it hits the opposing roller 31, the roller circumferential surface member 363 is pushed inward in the radial direction, so that the sheet scraping feeding means 364
is in contact with the trunk roller 30 and no gap is created. Since the roller circumferential member 363 is an elastic body, when the sheet scraping means 364 passes the trunk roller 30, the roller circumferential member 363 is pushed outward in the radial direction and comes into contact with the opposing roller 31. The sheet scraping and feeding means 364 comes into contact with the trailing edge of the sheet and scrapes it. That is, due to the elasticity of the legs 362 and the scraping roller peripheral member 363, the roller peripheral member 36
3 and its sheet scraping feed means 364 are always in contact with the opposing roller 31, so that no gap is created between the scraping rollers 36a, 36b and the opposing roller 31. Since the scraping rollers 36a, 36b are arranged so that their end surfaces are in contact with the shaft 34 on which the trunk roller 30 is disposed, there is also a gap between the scraping rollers 36a, 36b and the trunk roller 30. There is no. As described above, according to the present invention, the sheet is not only raked and fed, but also by the main rollers 35a to 35c, the raking rollers 36a and 36b, and the opposing roller 3.
There is no gap between the three parties.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing the mechanism of a copying apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing details of the paper discharge roller 25 of the apparatus shown in FIG. FIG. 3 shows the scraping feed roller 3 shown in FIG.
6a is a side view. FIGS. 4a and 4b are explanatory diagrams illustrating recording sheet feeding by the paper ejection roller 25 shown in FIG. 2. FIG. Figure 5 shows the second
It is a side view which shows the modification of the scraping roller 36a shown in FIG. 3, FIG. 4a, and FIG. 4b.
FIGS. 6a and 7a are perspective views showing examples of conventional sheet feeding devices. Figures 6b and 7
FIG. b is an explanatory diagram illustrating sheet feeding by the sheet feeding devices of FIGS. 6a and 7a, respectively. 1... Contact glass, 2... Pressure plate, 3...
Exposure lamp, 4...first mirror, 5...second mirror, 6...third mirror, 7...condensing lens, 8...
...Fourth mirror, 9... Photosensitive drum, 10... Discharge lamp, 11... Charger, 12... Eraser, 13... Developing unit, 14... Transfer charger, 15... Separation charger, 16... Separation claw, 17...Cleaning unit, 18,1
9... Paper feed cassette, 20, 21... Paper feed roller,
22... Registration roller, 23... Conveyor belt,
24... Fixing unit, 25... Paper ejection roller, 2
6... Paper discharge tray, 30, 54, 64... Upper roller, 31, 66a, 66b, 66c... Pressure roller (opposed roller), 32, 55, 65... Driven shaft, 33, 50, 60... ...lower roller, 34,5
1, 61... Drive shaft, 34... (roller shaft), 3
5a, 35b, 35c, 52a, 52b, 62
a, 62b, 62c... Drive roller (trunk roller), 36a, 36b, 63a, 63b... Scraping roller (scraping feed roller), 361... Inner cylinder (boss-shaped member), 362... Leg portion ( leg),
363...Notch piece (scraping roller circumferential member), 364...Protrusion (sheet scraping feeding means), 5
3a, 53b, 53c, 57a, 57b, 57
c, 57d... Sheet feed roller, 56a, 56
b...Followed roller, PA...Recording sheet.

Claims (1)

[Claims for Utility Model Registration] At least one trunk roller having a cylindrical circumferential surface and arranged on the same axis, and such that the end surface of the trunk roller is in contact with the axis on which the trunk roller is disposed. In the sheet feeding device, the sheet feeding device includes a scraping roller that is disposed in the trunk roller and rotates integrally with the trunk roller, and an opposing roller having a cylindrical circumferential surface that is in contact with the peripheral surfaces of the trunk roller and the scraping roller. The roller includes a boss-shaped member disposed on a shaft, a plurality of legs that stand radially outward from the boss-shaped member to a height of the circumferential surface of the trunk roller, and one end supported by the legs. a sheet scraper, which extends from the tip of the leg in a certain direction in the circumferential direction to the vicinity of the other leg with a space between it and the boss-shaped member, and scrapes the sheet to the other end. a scraping roller peripheral surface member having means, the boss-shaped member, the leg and the scraping roller peripheral surface member are integrally formed of an elastic body, and the other end of the scraping roller peripheral surface member is The provided sheet scraping means is configured to be higher than the circumferential surface of the main roller, and when it comes into contact with the opposing roller, it is pushed down inward in the radial direction and is displaced to a height equal to the circumferential surface of the main roller. Device.