JPS60209772A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate the need for an extra space and obtain destaticizing effect securely without making constitution complex by incorporating a conductive material in a fixing roller and destaticizing a carrier. CONSTITUTION:A fixing device 38 fixes a toner image on transfer paper 33 by a heat roller 43 and a pressure roller 44 while clamping and conveying the transfer paper 33. Those heat roller 43 and pressure roller 44 are constituted by providing heat-resisting rubber materials 43b and 44b which contain a conductive material to outer peripheral parts of metallic shafts 43a and 44a. The transfer paper 33 to which the toner image is transferred is charged electrostatically, but is passed through the fixing device 38 to destaticize both surfaces by the heat roller 43 and pressure roller 44. Consequently, the transfer paper 33 never jams by being wound around the pressure roller 44 and discharged sheets of transfer paper 33 do not attract each other, so that there is no trouble during paper discharge. Further, a destaticizing device need not be provided separately, no extra space is unnecessary, and the constitution is prevented from becoming complex.

Description

DETAILED DESCRIPTION OF THE INVENTION [Sixteen Fields of the Invention] The present invention relates to image forming apparatuses such as electronic printers and electronic copiers.

[Technical background of the invention and its problems]

For example, in electronic printers, one configured as shown in FIG. 1 is conventionally known. That is, this device exposes the surface of a photosensitive drum 4 with laser light 3 scanned by a scanning device 2 including a rotating mirror 1, etc., to form an electrostatic latent image. Next, this electrostatic latent image is developed by a developing device @5 to form a toner image. On the other hand, transfer paper 7 is fed one by one from the paper feed cassette 6 by a paper feed roller 8, and the toner image on the surface of the photosensitive drum 4 is transferred onto the transfer paper 7 by a transfer device 9. Next, this transfer paper 7 is sent via a reversing roller 10 and a conveyance bell 1-11 to a fixing device 14 consisting of, for example, a heating roller 12 and a pressure roller 13 to fix the toner trace, and then the paper is transferred by a paper ejection roller 15. The configuration is such that the paper is discharged onto the paper discharge 1-ray 16 and printing is performed in this manner.

By the way, in such an apparatus, the transfer paper 7 on which the toner image has been transferred is charged with static electricity, and is directly transferred to the fixing device 1.
4, when the transfer paper 7 is fixed by the heat roller 12 and the pressure roller 13, it may not only wrap around the pressure roller 13 and cause a jam, but also cause the ejected transfer paper 7 and ...There is a problem that adsorption occurs between paper sheets, causing inconvenience when paper is ejected.

Therefore, conventionally, in order to solve the above problem, a static eliminator 17 for neutralizing the pressure roller 13 and a static neutralizing device 18 for neutralizing the transfer paper 7 are provided. However, when these static eliminators 1F17 and 18 are provided, there is a problem that not only an extra space is required, but also the configuration becomes complicated.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and an object of the present invention is to provide an image forming apparatus that can reliably obtain a static elimination effect without requiring extra space or complicating the configuration. It is about providing.

[Summary of the invention]

In order to achieve the above object, the present invention includes an image carrying means for carrying an image on a carrier, and a pair of fixing rollers that pinch and convey the carrier on which the image is carried by the image carrying means. and a fixing device for fixing the image, and the fixing device is characterized in that the fixing roller contains a conductive substance to eliminate static electricity from the carrier.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 2 and 3. The third section shows a laser printer as an image forming apparatus according to the present invention, and numeral 21 in the figure is a book. A photosensitive drum 22, which rotates in a predetermined direction depending on the printing process, is supported on a substantially medium flame within the main body 21. Above this photosensitive drum 22 is a rotating mirror 23.
A scanning device 24 is provided, and the surface of the photosensitive drum 22 is exposed to laser light 25 scanned by a rotating mirror 23, thereby forming an electrostatic latent image. Further, around the photosensitive drum 22, the scanning device 2
In order from the exposure position according to No. 4 along the rotational direction of the photosensitive drum 22, the present device 26, the transfer device 27, the peeling device 28,
A purifying device 29, a static eliminator @30, and a charging device 31 are provided.

Further, at the bottom of the main body 21, a transfer path 34 for transfer paper (carrier) 33 passing through a transfer section 32 between the photosensitive drum 22, transfer device 27, and peeling device 28 is provided. The transfer paper 33 independently fed from the paper feed cassettes 35 and 36 is transferred to the paper ejection tray 40 by sequentially controlling the register I roller 37, the transfer section 32, the fixed paper device 38, and the paper ejection roller 39. It is supposed to be done.

When an electrostatic latent image is formed on the photosensitive drum 22 by the scanning device 24, this electrostatic latent image is developed by the developing device 26, thereby forming a toner image. On the other hand, when the transfer paper 33 is fed one by one by the paper feed rollers 41 and 41 from the first or second paper feed cassette 35, 36, the transfer paper 33 comes into contact with the registration roller 37 and is aligned. After that, the toner image is stopped, and after timing with the toner image on the photosensitive drum 22, it is restarted and sent to the transfer section 32. Then, in the transfer section 32, the toner image on the photosensitive drum 22 is transferred onto the transfer paper 33 by the transfer device 27. Next, the transfer paper 33 on which the image has been transferred is peeled off from the photosensitive drum 22 by a peeling device 28 and sent to a fixing device 38 by an adsorption belt 42, where the toner image is transferred.

Then, the fixing device 38 transfers the image onto the transfer paper 3.
3 is discharged onto a paper discharge tray 40 by a paper discharge roller 39.

By the way, the fixing device 38 uses a heating roller (fixing roller) 43 and a pressure roller (fixing roller) 44 to fix the transfer paper 3.
3, the i/toner image is fixed on the transfer paper 33 while the transfer paper 33 is being nipped and conveyed, and electricity is removed from both sides of the transfer paper 33 during this nipping and conveyance, as shown in FIG. That is, the heating row 543 and the pressure roller 44 are constructed by providing heat-resistant rubber materials 43b' and 44b@ containing a conductive substance on the outer periphery of the metal shirts t-43a and 44a, respectively. Shaft 43a.

44a is rotatably supported on a grounded metal frame 45 via bearings 46 and 46. Further, the heating row 543 has a heater 47 built into the metal shaft 43a, and a metal shirt h 43.
A gear 48 is fixed to the end of a, and driving force is transmitted through this gear 48. On the other hand, the pressure roller 44 is rotated as a result of the heating roller 43.

According to the above configuration, the transfer paper 33 to which the toner image has been transferred
is charged with static electricity, but when the transfer paper 33 passes through the fixing device 38, it is heated by a heating roller 43 and a pressure roller 44.
Static electricity is removed from both sides.

This prevents the transfer paper 33 from wrapping around the pressure roller 44 and causing a jam. Further, the discharged transfer sheets 33A do not stick to each other, and no inconvenience occurs when the sheets are discharged. Furthermore, since there is no need to separately provide a static eliminator, no extra space is required and the configuration does not become complicated.

Note that the fixing device 38 is not limited to the above embodiment, and may be configured as shown in FIG. 4 or FIG. 5, for example. That is, in the embodiment shown in FIG. 4, the metal leaf springs 49, 49 are fixed to the frame 51 with screws 50, and their tips are connected to the fully bent shaft t-43a of the heating roller 43, respectively. Metal shifter 1 of pressure roller 44
44a, and these leaf springs 49 and 49 are also grounded. Further, in the embodiment shown in FIG. 5, the metal plate springs 49, 49 are fixed to the frame 51 by screws 50, and their tips are connected to the surface of the heating roller 43 and the surface of the pressure roller 44, respectively. These plates are in pressure contact with each other, and the plates 49 and 49 are also grounded. According to such an embodiment, a defrosting effect can be obtained even when the frame 51 has no conductivity.

Further, in the above embodiment, the fixing device 38 is replaced by the heating roller 43.
The configuration is such that fixing is performed by the heating and pressing effects of the heating roller 43 and the pressure roller 44, and the heating roller 43 and the pressure roller 44 are grounded to perform static elimination.
The present Komei is not limited to this, but has a structure in which the fixing device performs fixing by pressure IY using a pair of pressure rollers,
The pressure roller may be grounded, and the same effect can be obtained even in this case.

Further, in the above embodiment, a laser printer that performs single-sided printing is described, but the present invention is also effective in a laser printer that performs double-sided printing as shown in FIG. Of course, this laser printer uses a rotating mirror 61.
A laser beam 6 scanned by a scanning device 62 consisting of a
3, the photosensitive drum 64 is exposed to light to form a static N latent image.

Then, this electrostatic latent image is developed by a developing device 65 to form a toner image. On the other hand, transfer paper (
A transfer device 70 transfers the transfer paper 69 to the transfer paper 69.
The toner image on the photosensitive tram 64 is transferred. Next, this transfer paper 69 is sent to the fixing device 71 and then! Fix the henna image on six transfer papers. Then, these six transfer papers are temporarily stacked in the stacking section 73 via the goo-i-conveyance mark 72. Next, the six stacked transfer sheets are taken out by the take-out roller 74, and in the same manner as described above, printing is performed on the opposite side of the transfer sheet 69, and the sheets are discharged onto the discharge sheets 1 to 75. With this configuration, the transfer paper 69 with prints printed on one side is electrically charged, and when the transfer paper 69 is fed again to print on the opposite side of the transfer paper 69, it wraps around the photosensitive drum 64, causing the transfer paper 69 to become electrically charged. Not only may this cause V-hum, but also the stacked transfer sheets 69 may stick to each other, resulting in inconveniences such as taking out two sheets when taking out the fixing device 71. By having the same configuration as No. 38, the adverse effects of static electricity can be prevented and paper can be conveyed smoothly.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided an image carrying means for carrying an image on a carrier, and a carrier on which an image is carried by the image carrying means is held and conveyed between a pair of fixing rollers. A fixing device for fixing the image is used, and the fixing device has a structure in which the fixing roller contains a conductive substance to eliminate static electricity from the carrier.
Excellent effects such as a reliable static elimination effect can be achieved without requiring extra space or complicating the configuration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing a conventional example, FIG. 2 is a sectional view schematically showing an embodiment of the present invention, FIG. 3 is a sectional view showing a fixing device of the same embodiment, and FIG. The figure is a sectional view showing another embodiment of the fixing device, FIG. 5 is a sectional view showing still another embodiment of the fixing device, and FIG. 6 is a schematic diagram of an apparatus for automatic double-sided printing to which the present invention is applied. FIG. 33.69... Carrier (transfer paper), 43... Fixing roller (heating roller), 44... Fixing roller (pressure roller), 38.71... Fixing device, 43a, 44a...
・Shaft, 46...bearing), 49...
・Leaf spring. Applicant's Representative Patent Attorney Takehiko Suzue No. 31 Saw Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. Image carrying means for carrying an image on a carrier, and fixing the image on the carrier by sandwiching and conveying the carrier on which the image is carried by the image carrying means between a pair of fixing rollers. 1. An image forming apparatus, comprising: a fixing device, the fixing device having a structure in which the fixing roller contains a conductive substance to eliminate static electricity from a carrier. 2. The fixing device has a configuration in which one of a pair of fixing rollers is a heating roller and the other is a pressure roller, and fixing is performed by heating action and pressure action. image forming device. 3. The image forming apparatus according to claim 1, wherein the fixing device has a configuration in which a pair of fixing rollers are pressed together and fixing is performed by pressure action. 4. The image forming apparatus according to claim 1, wherein the fixing device is configured such that the shafts of the pair of fixing rollers are grounded via bearings. 5. The image forming apparatus according to claim 1, wherein the fixing device has a structure in which a conductive plate spring is pressed into contact with the shirt l of the pair of fixing rollers, and this plate spring is grounded. 6. The image forming apparatus according to claim 1, wherein the fixing device has a structure in which a conductive leaf spring is pressed against the surface of the pair of fixing rollers, and the leaf spring is grounded. 7. The image forming apparatus according to claim 1, wherein the image carrying means is configured to carry an image on one or both sides of the carrier.