JPH032538Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a paper feeding mechanism for sequentially passing copy paper sent from a paper feeding section through a transfer section and a fixing section in an electronic copying machine.

In an electronic copying machine, a copy sheet having a visible image transferred by a transfer section is passed through a fixing section, and the visible image is fixed on the copy sheet by heating in the fixing section. Conventionally, a plurality of pairs of rollers that are in rolling contact with each other are arranged in a fixing section, and a copy sheet is sandwiched between both rollers of the pair of rollers, and is sent sequentially through the pairs of rollers. Since the copy paper passes through a pair of rollers before the toner visible image heated in the fixing section is sufficiently cooled, some of the toner in the visible image adheres to the roller, and the toner on the roller is transferred to the copy paper. Due to the re-adhesion, there was a drawback that a thin band-shaped roller mark was formed at the portion of the copy paper that came into contact with the roller. As copying machines become smaller, the visible image within the fusing section is less sufficiently cooled and the roller marks become more noticeable.

From this point of view, in Utility Model Application No. 1986-8605, in the transfer section that transfers the visible image of toner on the photosensitive drum onto copy paper, first and second The belts are moved simultaneously, and one side edge of the copy paper is sandwiched between the first and second belts,
It has been proposed that the copy paper that has passed through the transfer section is peeled off from the photosensitive drum and is then passed through the fixing section using the first and second belts. If this is done, the roller marks will not occur. However, because the belt is driven synchronously with the photosensitive drum by placing part of the belt over one side edge of the photosensitive drum, when the toner is brought into contact with almost the entire width of the photosensitive drum in the developing section, the toner is toner adhered to the belt, and there was a risk that the toner adhered to the belt would adhere to the copy paper.

The object of this invention is to provide a paper feeding mechanism for an electronic copying machine that does not cause the copy paper to be soiled by toner in the developing section.

In this invention, first and second first and second
The belt is transported in synchronization with the photosensitive drum, and the first and second belts are sequentially sent to the fixing section and the delivery section in an overlapping state, and from there, the first and second belts are respectively passed through separate paths. Circulate.

Hereinafter, an embodiment of the paper feeding mechanism of an electronic copying machine according to this invention will be described with reference to the drawings. A photosensitive drum 12 is rotatably held within a case 11 of an electronic copying machine. The photosensitive drum 12 is capable of uniformly accumulating electric charges on its outer peripheral surface and projecting a light image onto the accumulated electric charges to form an electrostatic latent image, that is, an image of the electric charge. It is possible to use a sheet with a photosensitive layer formed on the outer peripheral surface of the drum, or a sheet with a photosensitive layer formed around a drum. Further, although a rotation mechanism for the photosensitive drum 12 is not shown in the figure, it is provided as a drive unit 13 in a space inside the photosensitive drum 12, for example.

A document table 14 is provided on the top surface of the case 11 so as to be movable left and right in the figure. The document table 14 is made of transparent glass, for example, and the document 15 is placed on it. A corotron 17 is provided on the bottom plate 16 side of the casing 11 so as to closely face the circumferential surface of the photosensitive drum 12 . A high voltage is applied to the photosensitive drum 12 by the corotron 17, so that charges can be uniformly accumulated on the outer peripheral surface of the photosensitive drum 12. When the charged portion of the photosensitive drum 12 is rotated clockwise in the figure as shown by the arrow and positioned on the document table 14 side, that is, when it is rotated to the exposure position 18, the document on the document table is rotated. 15 are sequentially reflected by reflecting mirrors 19 and 21, and are further imaged onto the photosensitive drum 12 by a lens 22. As a result, a charge image, a so-called electrostatic latent image, is formed on the photosensitive drum 12.

As the rotation of the photosensitive drum 12 progresses, this electrostatic latent image on the photosensitive drum 12 reaches a developing section 23 provided opposite the upper right side of the photosensitive drum 12 in the figure. In the developing section 23, the toner 24
is brought into contact with the surface of the photosensitive drum 12 by the magnet roller 25, and toner is attached by the charge on the drum 12, forming a toner image, that is, a visible image. As the rotation of the photosensitive drum 12 progresses, this visible image approaches the bottom plate 16 side in the figure, and the copy paper 42 fed from the paper feed section 26 comes into contact with the drum surface of the visible image, making a copy. The paper 42 moves together with the photosensitive drum 12, and at the position of the corotron 17, the visible image is transferred to the copy paper 42 by the high voltage. The copied copy paper 4
2 passes through the fixing section 27, and at this time, the visible image is fixed on the copy paper 42 by the heat of the heat generating light source 28 and sent out of the case 11.

In this example, the light from the heat-generating light source 28 for heat fixing is used for exposure. That is, the light from the light source 28 is guided to the original on the original platen 14, and an optical path 29 is formed so that the reflected light reaches the exposure position 18. In the figure, the heat-generating light source 28 is provided above the copy paper path 31 extending left and right in the fixing section 27, and a reflective plate 32 that is inclined upwardly to the right is provided on the upper left side of the heat-generating light source 28. The light from the light source 28 is irradiated and reflected, and the reflected light passes through the document table 14 and reaches the document 15. The reflected light from the document table 14 is sequentially reflected by the reflecting mirrors 19 and 21, and then reaches the projecting lens 22. It is incident. It is preferable to provide a heat absorbing filter 33 in the middle of the optical path 29 from the heat generating light source 28 to the document 15 to absorb the heat from the heat generating light source 28 . As the heat generating light source 28, for example, a halogen lamp, which is conventionally used for this type of heat fixing, can be used.

A reflector 3 is disposed below the reflector 32 in close opposition to the reflector 32.
6 are provided, and these reflecting plates 32 and 36 shield the exposure optical path 29 from the outside. Further, a heat absorption filter 33 is held between the reflection plates 32 and 36. A light amount adjusting plate 40 is provided to adjust the amount of light passing through the optical path 29. In order to effectively utilize the heat of the heat generating light source 28 for the fixing action in the fixing section 27, a reflecting plate 37 is provided above the heat generating light source 28, facing the passage 31, for reflecting the light from the heat generating light source 28 toward the passage 31 side. , 38 are the reflecting plates 32, 36
and are connected to each other and provided on both sides of the heat generating light source 28, and these constitute an oven. The entrance of this oven, that is, the entrance of the fixing section 27 is provided near the exit side of the photosensitive drum 12 of the corotron 17, and a shielding plate 39 for opening and closing the entrance is rotatably provided. The shielding plate 39 is closed to block the light from the heat-generating light source 28 from reaching the photosensitive drum 12, so that the charges on the photosensitive drum accumulated by the corotron 17 are prevented from being discharged. The copy sheet passing through the corotron 17 and having the visible image transferred thereon is allowed to enter the fixing section 27 .

In the paper feed section 26 at the lower right of FIG.
When the copy paper rotates, it is sent out from the paper case 41 toward the photosensitive drum 12 , and the leading edge of the copy paper hits the stopper 44 and is placed on standby in the immediate vicinity of the photosensitive drum 12 . When the electrostatic latent image on the photosensitive drum 12 reaches close to the stopper 44, the stopper 44 moves downward in the figure and is removed, and the movable roller 45 descends to press the copy paper 42 against the drive roller 46 to remove the copy paper. 42 is sent along the circumferential surface of the photosensitive drum 12.

In this invention, the paper feeding mechanism for feeding the copy paper is constructed as follows. That is, as shown in FIGS. 1 and 2, the paper feed section 26, the vicinity along the periphery of one end of the photosensitive drum 12 in the transfer section 47 where transfer is performed by the corotron 17, and further around the fixing section 27. A belt 48 is provided. In addition to the roller 46, the belt 48 includes a roller 34 at the entrance of the transfer section 47, a plurality of rollers 49 in the fixing section 27, a feed roller 51 that sends out the fixing section 27, and appropriately arranged rollers 52. In this case, at least from the entrance to the exit of the transfer section 47, the peripheral surface of the photosensitive drum 12 is located on an axially extended surface of the photosensitive drum 12, and is close to one side edge of the drum. It is made to move parallel to and at the same time as this.

Further, the belt 53 is brought into contact with the belt 48 near the entrance of the transfer section 47, moves together with the belt 48, passes through the transfer section 47, and moves the fixing section 27 at the same time while being in contact with the belt 48, and is fed out. It passes around the feed roller 54 that rolls in contact with the roller 51, passes through the guide roller 55, goes around the roller 56 that makes a pair with the roller 34, goes around the roller 56 that rolls in contact with the roller 34, and is returned to the entrance of the transfer section 47 and circulated.

The belts 48 and 53 are moved at the transfer portion 47 in synchronization with the movement of the circumferential surface of the photosensitive drum 12 . For this purpose, for example, as shown in FIG. 2, a belt 61 is placed around the peripheral surface of the photosensitive drum 12 at the end opposite to the belts 48, 53. On the other hand, the axis of the roller 54 is extended parallel to the axis of the photosensitive drum 12, a pulley 62 is mounted on the axis, and a belt 61 is placed around the pulley 62. A gear 63 is attached to the other end of the shaft of the roller 54 , and the gear 64 meshed with the gear 63 is fixed on the shaft of the roller 51 .
Therefore, the rotation of the photosensitive drum 12 drives the belt 61, which causes the pulley 62, roller 54,
The gear 63 is rotated, and the gear 64 is rotated by the gear 63. The equivalence ratio of the gears 63 and 64 is 1:1, and the roller 51 rotates at the same speed as the roller 54, so that the belts 48 and 53 are rotated at the same speed. It runs at the same speed as the circumferential speed of the photosensitive drum 12. If necessary, a shielding plate 65 is interposed between the belt 61 and the magnet roller 25, so that the toner on the magnet roller 25 near the belt 65 is transferred to the photosensitive drum 1.
You will be prevented from getting attached to 2.

Therefore, one side edge of the copy paper 42 fed from the paper feed section 26 to the photosensitive drum 12 is connected to the belt 48,
53 and not in contact with the belt 61. The copy paper 42 is attached to belts 48, 53
The transfer section 47 is sandwiched by the photosensitive drum 12.
The copy paper 42 that has passed along the transfer section 47 is peeled off from the photosensitive drum 12 and sent to the fixing section 27 side. Further from this, the roller 5 which is the sending part
The copy paper is delivered to the outside through 1 and 54.
In this example, as shown in FIG.
A static elimination lamp 57 is provided between the photosensitive drum 12 and the paper feed section 26 for projecting light onto the photosensitive drum 12 to remove electric charge. Furthermore, while the shielding plate 39 is open, light is transmitted from the heat generating light source 28 to the optical path 5.
As shown at 8, the photosensitive drum 12 is irradiated with electricity to eliminate static electricity.

As described above, according to the paper feeding mechanism of this invention, the copy paper 42 from the paper feed section 26 is sandwiched at one side edge by the belts 48 and 53, and is transported along the circumferential surface of the photosensitive drum 12 to the transfer section. 47, the visible image is transferred to the copy paper 42 at the transfer section 47, and the copy paper 42 that has passed the transfer section 47 is forced to move as the belts 48, 53 separate from the photosensitive drum 12 and enter the fixing section 27. The image is then peeled off from the photosensitive drum 12 and enters the fixing section 27, where the transferred visible image is thermally fixed and sent out to the outside of the casing 11.

In this way, the copy paper 42 is fed with its side edges sandwiched between the belts 48 and 53, so there is no need to provide a roller for feeding the copy paper 42 in the fixing unit 27, and heating during fusing is eliminated. Since the roller does not come into contact with the visible image that has been created, there is no risk of the rolling traces of the roller being left on the copy paper.

Further, since the belts 48 and 53 are circulated not over the photosensitive drum 12 but at a distance from this, there is no risk that the toner on the magnet roller 25 or the photosensitive drum 12 will stick to the belts 48 and 53.
There is no risk that the copy paper 42 will be smudged by the toner attached to the copy paper 53.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of an electronic copying machine to which this invention is applied, and FIG. 2 is a perspective view showing an example of a paper feeding mechanism according to this invention. 11... Enclosure, 12... Photosensitive drum, 14...
Original table, 15...Original, 18...Exposure position, 23
...developing section, 27...fixing section, 26...paper feeding section,
28... Heat generating light source, 48, 53... Belt, 5
1,54...Feeding roller.

Claims (1)

[Claim for Utility Model Registration] An image of a document is exposed to light on a photosensitive drum to form an electrostatic latent image, toner is applied to the electrostatic latent image to make it visible, and the visible image is transferred to the paper feed section. An electronic system that transfers the visible image onto copy paper sent from In the copying machine, a first belt that sequentially circulates around the paper feed section, the vicinity of one end of the photosensitive drum in the transfer section, the fixing section, and the delivery section; a second belt that circulates in contact with the first belt in the vicinity of the circumferential edge of one end of the photosensitive drum in the fixing section and the sending section; driving means for transporting the first and second belts respectively in synchronization with the peripheral edges, and one side edge of the copy sheet fed from the paper feed section is sandwiched between the first and second belts and the sheet is fed. A paper feed mechanism for an electronic copying machine.