JP4479941B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus capable of improving durability of an electrophotographic photosensitive member and preventing abnormal images such as image blurring and whitening, and a method for removing harmful substances from the image forming apparatus.
[0002]
[Prior art]
In general, in an electrophotographic process such as a copying machine or a printer, at least charging, exposure, development, transfer, and cleaning processes are performed on an electrophotographic photosensitive member, and a cycle of these processes is repeatedly performed. That is, as shown in FIG. 10, around the electrophotographic photosensitive member 11, there are a charging device 12, an original light image exposure mechanism 13, a developing device 14, a transfer electrode 15 and a separation electrode 16, a charge erasing electrode 17, and Cleaning mechanisms 18 are arranged in order. The toner attached to the electrostatic latent image on the surface of the photoconductor in the developing process by the developing device 14 is fed from the surface of the photoconductor by the paper feed roll 19 in the transfer process by the transfer electrode 15 and the separation electrode 16. It is moved to a transfer material 20 such as paper.
[0003]
In such an electrophotographic process, it is known that ozone and NOx gas are generated in the charging process, but these ozone and NOx gas adhere to the surface of an electrophotographic photoreceptor, particularly an organic photoreceptor, and deteriorate the photoreceptor. This causes an abnormal image. For this reason, a method of removing the generated ozone and NOx gas with an adsorbent or the like has been proposed. A method of providing a catalyst for promoting a denitration reaction on the surface of a wire to be heated has been proposed.
[0004]
[Problems to be solved by the invention]
However, ozone and NOx cannot be effectively removed by any method.
[0005]
Therefore, studies have been made to increase the ozone resistance and NOx resistance of the photoreceptor itself, but sufficient durability cannot be obtained.
[0006]
In view of such circumstances, the present invention improves the durability of an electrophotographic photosensitive member by effectively removing harmful substances, and can prevent abnormal images such as image blurring and whitening, and image formation It is an object to provide a method for removing harmful substances from an apparatus.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention for solving the above problem, in an image forming apparatus using an electrophotographic process including a charging process, a harmful substance removing device having a photocatalyst layer, and a harmful substance generated by the charging process are A gas guide means for contacting the photocatalyst layer, and a light source for irradiating light for activating the photocatalyst layer , wherein the harmful substance removing device has a cylindrical member having a plurality of through holes on an outer peripheral surface, The photocatalyst layer is provided on at least the inner peripheral surface of the cylindrical member, and the gas guiding means acts to introduce gas from the through hole and to discharge from one side or both ends in the axial direction. It is in the image forming apparatus.
[0009]
According to a second aspect of the present invention, in the first aspect, the photocatalyst layer is composed of at least one selected from the group consisting of titanium oxide, zinc oxide, tungsten oxide, iron oxide, strontium titanate, and the like. In the image forming apparatus.
[0011]
According to a third aspect of the present invention, in the first or second aspect, a foamed elastic member layer having air permeability is provided outside the cylindrical member, and the foamed elastic member layer cleans the surface of the photoreceptor. The image forming apparatus is in contact with the photosensitive member.
[0014]
In the present invention, harmful substances such as ozone and NOx can be effectively removed by the photocatalyst, and in particular, a cylindrical member having a photocatalyst layer on the inner surface is provided adjacent to the photoconductor, By introducing NOx into the inside of the cylindrical member and decomposing and removing it, harmful substances can be removed very effectively.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments.
[0016]
FIG. 1 shows an image forming apparatus according to an embodiment. This device is provided with a harmful substance removing device 30 adjacent to the charging device 12, and is basically the same as the device shown in FIG. Is omitted.
[0017]
The harmful substance removing device 30 includes a cylindrical member 33 having a plurality of through holes 31 and having a photocatalyst layer 32 on the inner peripheral surface, a foamed elastic member 35 provided on the outer peripheral surface of the cylindrical member 33, A photocatalytic activation lamp 37 provided on the opposite side, and a gas introduction fan 39 provided on both outer sides of the cylindrical member 33.
[0018]
The photocatalyst layer 32 is not limited as long as ozone and NOx can be removed. For example, titanium oxide, zinc oxide, tungsten oxide, iron oxide, strontium titanate, and particularly a titanium oxide layer is preferable.
[0019]
Further, an adsorbent such as activated carbon may coexist in the photocatalyst layer 32. As a result, the effect of removing harmful substances by adsorption and decomposing by a photocatalyst after adsorption is further effective.
[0020]
The photocatalyst activation lamp 37 is not particularly limited as long as the photocatalyst layer 32 made of a titanium oxide layer or the like is activated continuously or intermittently to continuously decompose and remove ozone and NOx. An ultraviolet irradiation lamp such as a black light can be used.
[0021]
The cylindrical member 33 is provided with a through hole 31 for taking in the ambient atmospheric gas inward, but the shape, number, etc. of the through hole 31 are not limited, and as shown in FIG. Good.
[0022]
The foamed elastic member 35 is preferably an open-celled one having air permeability, as long as harmful substances such as ozone and NOx can be introduced into the cylindrical member 33 through the foamed elastic member 35.
[0023]
Further, since the foamed elastic member 35 is provided in contact with the photoconductor 11, a material that can clean the surface of the photoconductor without contaminating the photoconductor 11 is preferable. For example, the foamed elastic member 35 is formed of foamed polyurethane, silicone rubber, or the like. That's fine.
[0024]
The gas introduction fan 39 may act so as to introduce the atmospheric gas from the through hole 31 and discharge it from the cylindrical member 33 and both ends.
[0025]
When such a harmful substance removing device 30 is provided, ozone and NOx generated in the charging device 12 are introduced into the cylindrical member 33 by the gas introduction fan 39 and contacted with the photocatalyst layer 32 to be effectively decomposed. The body 11 is not contaminated. The photocatalyst layer 32 is activated by irradiation with the photocatalyst activation lamp 37, and the action of removing ozone and NOx continues.
[0026]
Such a photocatalyst layer 32 may be provided in any manner that can effectively decompose and remove ozone and NOx, but it is efficient to provide the photocatalyst layer 32 on the inner peripheral surface of the cylindrical member. This is because the atmospheric gas can be effectively introduced and decomposed and removed from the whole of the photoreceptor 11 in the axial direction.
[0027]
When the cylindrical member 33 is used, the photocatalytic layer 32 may be provided on the outer side of the cylindrical member or only on the outer peripheral surface.
[0028]
Further, the foamed elastic member 35 is not particularly required when the photocatalyst layer is provided on the outer peripheral surface, and the photocatalyst layer provided on the outer peripheral surface is minimally activated by light irradiation from the charging device 12. Can do.
[0029]
Various structures can be employed to increase the surface area of the photocatalyst layer, and these structures are free to employ.
[0030]
In the above-described embodiment, the cylindrical member 33 is also fixed in the rotational direction.
[0031]
(Test Example 1)
2, the photocatalyst layer 32 was a titanium oxide (TiO ₂ ) layer, the foamed elastic member 35 was a polyurethane sponge, and NOx-containing gas was repeatedly passed to measure the NOx concentration. The results are shown in FIG. The titanium oxide layer is made by mixing titanium oxide having a particle size of 20 μm with a binder made of a fluororesin such as PTFE or FEVE and a solvent made of an organic solvent such as water or xylene, and applying this by spray coating or the like, followed by drying. Formed by volatilizing the solvent. As the photocatalyst activation lamp 37, black light was used. A similar apparatus was used as a comparative example except that the photocatalyst layer 32 was not provided.
[0032]
As a result, it was found that when the photocatalytic layer 32 made of titanium oxide was provided, NOx was effectively decomposed.
[0033]
(Test Example 2)
In the harmful substance removing apparatus of FIG. 2, the test was performed in the same manner as in Test Example 1 except that the particle diameter of the titanium oxide formed with the titanium oxide (TiO ₂ ) layer was changed to 10 μm, 20 μm, and 100 μm. The results are shown in FIG.
[0034]
As a result, it was found that NOx is more effectively decomposed as the particle size is smaller.
[0035]
(Test Example 3)
Test Example 1 except that the photocatalyst layer 32 in which the titanium oxide (TiO ₂ ) layer is formed of titanium oxide having an anatase type and a rutile type having a particle size of 20 μm was used in the harmful substance removing apparatus of FIG. Were tested in the same manner. The results are shown in FIG.
[0036]
As a result, it was found that the properties of titanium oxide that decompose harmful substances are hardly affected by the crystal structure.
[0037]
(Test Example 4)
In the hazardous substance removing device of FIG. 2, as the photocatalyst activating light 37, other black light (UV intensity 3 mW / cm ^2), a high pressure mercury lamp (UV intensity 20 mW / cm ^2), a white fluorescent lamp (UV intensity 0.01 mW / Test was conducted in the same manner as in Test Example 1 except that cm ² ) was used. The results are shown in FIG.
[0038]
As a result, it was found that the activation of titanium oxide depends on the intensity of ultraviolet light, and the activation is insufficient with a white fluorescent lamp.
[0039]
(Test Example 5)
2 was tested in the same manner as in Test Example 1 except that the photocatalyst layer 32 was formed of titanium oxide (TiO ₂ ) and activated carbon (titanium oxide: activated carbon = 90: 10). The results are shown in FIG.
[0040]
As a result, it was found that NOx was decomposed more effectively when the activated carbon coexists.
[0041]
(Test Example 6)
2 except that the photocatalyst layer 32 formed of zinc oxide (ZnO) and iron oxide (Fe ₂ O ₃ ) is used in addition to titanium oxide (TiO ₂ ) in the harmful substance removing apparatus of FIG. Tested. The results are shown in FIG.
[0042]
As a result, it was found that zinc oxide (ZnO) and iron oxide (Fe ₂ O ₃ ) also have an effect of decomposing NOx, but titanium oxide decomposes NOx most effectively.
[0043]
【The invention's effect】
According to the present invention, ozone, NOx, and the like generated from the charging unit of the image forming apparatus can be effectively removed, so that the durability of the photoconductor can be improved and the occurrence of an abnormal image or the like can be removed. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic view of an image forming apparatus according to an embodiment of the present invention.
FIGS. 2A and 2B are a perspective view and a cross-sectional view of the harmful substance removing apparatus of the apparatus of FIG.
FIG. 3 is a perspective view showing a modification of the embodiment of the present invention.
FIG. 4 is a graph showing the results of Test Example 1 of the present invention.
FIG. 5 is a graph showing the results of Test Example 2 of the present invention.
FIG. 6 is a graph showing the results of Test Example 3 of the present invention.
FIG. 7 is a diagram showing the results of Test Example 4 of the present invention.
FIG. 8 is a diagram showing the results of Test Example 5 of the present invention.
FIG. 9 is a graph showing the results of Test Example 6 of the present invention.
FIG. 10 is a schematic diagram illustrating an image forming apparatus according to a conventional technique.
[Explanation of symbols]
30 Toxic Substance Removal Device 31 Through Hole 32 Photocatalyst Layer 33 Cylindrical Member 35 Foamed Elastic Member 37 Photocatalyst Activation Lamp 39 Gas Introducing Fan

Claims (3)

In an image forming apparatus using an electrophotographic process including a charging process, a harmful substance removing device having a photocatalyst layer, a gas guiding means for bringing a harmful substance generated by the charging process into contact with the photocatalyst layer, and the photocatalyst layer A light source that emits light to be activated, and the harmful substance removing device has a cylindrical member having a plurality of through holes on an outer peripheral surface, and the photocatalyst layer is provided on at least an inner peripheral surface of the cylindrical member. The image forming apparatus is characterized in that the gas guiding means acts to introduce gas from the through-hole and discharge it from one or both ends in the axial direction. 2. The image forming apparatus according to claim 1 , wherein the photocatalytic layer is made of at least one selected from the group consisting of titanium oxide, zinc oxide, tungsten oxide, iron oxide, strontium titanate, and the like. 3. The foamed elastic member layer having air permeability on the outside of the cylindrical member according to claim 1 , wherein the foamed elastic member layer is in contact with the photoconductor for cleaning the surface of the photoconductor. An image forming apparatus.

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