JP2002296987A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which eliminates image blur by keeping the ozone concentration of an atmosphere around an image carrier at a prescribed value or lower correspondingly to the classification of the image carrier. SOLUTION: Ozone is generated around a photoreceptor drum 100 as the image carrier by electrification of the photoreceptor drum with an electrifying charger (corona discharger) 201. It is necessary to reduce the ozone concentration to 25 ppm or lower in the case that the photoreceptor drum is, for example, an organic photoreceptor body. Therefore, an ozone concentration controller 5 is provided to adsorb and remove ozone. That is, not only outside air is sucked by a fan 7 in a connection tube 6 but also air is discharged by a fan 10 in a connection tube 8, and sucked outside air is accompanied with ozone in the atmosphere around the photoreceptor drum, ad the outside air accompanied with ozone is made to pass an ozone treatment filter 9 through the periphery of the electrifying charger and the outside peripheral surface of the photoreceptor drum, and ozone is adsorbed and removed by this filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
More specifically, the present invention relates to an image forming apparatus such as a facsimile, and more specifically, an image forming apparatus that regulates an ozone concentration in an atmosphere around an image carrier (a member for carrying an electrostatic latent image, for example, a photosensitive drum) to a predetermined value or less. The present invention relates to a forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus, an image is formed by charging an image carrier, and high density ozone is generated by the charging. The ozone adversely affects the photoreceptor, and the image may be blurred due to the flow of the electrostatic latent image on the photoreceptor. For this reason, in an image forming apparatus using an electrophotographic method, a technique for regulating the degree of oxidation of the surface of an image carrier and the amount of adhered discharge products during image formation has conventionally been employed. One example is JP-A-8-16049.

The "electrophotographic method using an amorphous silicon photoreceptor" disclosed in Japanese Patent Application Laid-Open No. 8-16049 carries out main charging, image exposure, charging before development and transfer and transfer to an amorphous silicon photoreceptor. In the electrophotographic method, the atmosphere of the photoconductor and the surface accuracy thereof (by polishing) are adjusted so that the value of the degree of oxidation x and the amount of adhesion of the discharge product y on the surface of the photoconductor satisfy y ≦ a · exp (−bx). ) Is maintained. In the above formula, the symbol a is a value of 2.2 × 10 ^{-9 and} the symbol b is a value of 2.0.

In the above-mentioned known technique, by maintaining the photosensitive member in a state satisfying the above expression, there is no image deletion, the life of the photosensitive member is extended, and the effect of obtaining a stable image over a long period of time can be improved. . However, this known technique is limited to the case where the type of photoreceptor is an amorphous silicon photoreceptor, as described above, and does not specify other photoreceptors. Further, the degree of oxidation of the surface of the photoreceptor and the amount of adhered discharge products are employed as criteria for determining the contamination of the photoreceptor. However, both of these require time and labor for measurement, and are difficult to employ in practice.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to prevent image quality defects with a simple structure and to use a type of image carrier (that is, a characteristic of a surface layer thereof). The object of the present invention is to provide an image forming apparatus in which the upper limit of the ozone concentration is regulated in accordance with the type of the image carrier without particular limitation.

[0006]

In order to achieve the above object, an invention according to claim 1 is to determine the concentration of ozone in the atmosphere around an image carrier, the type of the image carrier, that is, the characteristics of its surface layer. And an image forming apparatus configured to regulate the image forming apparatus to a predetermined value or less in accordance with the image forming apparatus. In the present invention, image quality defects can be prevented by adopting a relatively simple configuration that regulates the concentration of ozone generated by charging in accordance with the type of the image carrier. Can be easily adopted in actual equipment and has a wide range of applications.

According to a second aspect of the present invention, an organic photoreceptor is provided as an image carrier, and the predetermined value is 25 ppm.
The image forming apparatus according to claim 1, wherein: By setting the upper limit of the ozone concentration to 25 ppm, the occurrence of image blur and the like is prevented in all the organic photoconductors. Although there are various types of image carriers, most of them are organic photoreceptors, and it is possible to prevent poor image quality by maintaining the atmosphere within the above upper limit. .

According to a third aspect of the present invention, an organic photoreceptor having a surface coated with a lubricant is provided as an image carrier.
The image forming apparatus according to claim 1, wherein the predetermined value is set to 15 ppm. The surface of the image carrier is usually in a state in which a lubricant is applied. In this case,
By setting the upper limit of the ozone concentration to 15 ppm, quality defects such as image deletion can be prevented. As described above, when the organic photoreceptor to which the lubricant is applied is provided, it is preferable that the predetermined value is set lower than when the organic photoreceptor to which the lubricant is not applied is provided.

Further, the invention according to claim 4 is characterized in that the lubricant is an organic solid lubricant, a fluororesin (Teflon (registered trademark))
The image forming apparatus according to claim 3, wherein the image forming apparatus is a lubricant of (system) or an inorganic solid lubricant. As the lubricant, an organic solid lubricant is most preferable, but a Teflon-based lubricant or an inorganic solid lubricant can also be used, and the effect of suppressing insect biting can be enhanced.

According to a fifth aspect of the present invention, there is provided a corona discharge device as an electrification charger provided opposite to the image carrier, the ozone generating source causing the atmosphere around the image carrier to contain ozone. The image forming apparatus according to claim 1, wherein: Ozone generation is mostly due to discharge from the charger. In this case, by maintaining the ozone atmosphere within the upper limit, image quality defects such as image deletion are prevented. Therefore, the present invention can be widely applied to image forming apparatuses actually used.

According to a sixth aspect of the present invention, a corona discharger is provided so as to face the photosensitive drum, and the ozone concentration in the atmosphere around the photosensitive drum is adjusted according to the characteristics of the surface layer of the photosensitive drum. An image forming apparatus provided with an ozone concentration regulating device that regulates the ozone concentration to not more than a predetermined value, wherein the ozone concentration regulating device has a first end surrounding a corona discharger and the other end opening to a housing outer wall of the image forming apparatus. A connecting pipe, a second connecting pipe having one end close to the outer peripheral surface of the photosensitive drum and the other end opening to the outer wall of the housing of the image forming apparatus, a first fan provided in the first connecting pipe, And a second fan having a gas-permeable ozone adsorbing member provided in the second connecting pipe.
And discharging the outside air sucked by the fan through the periphery of the corona discharger, the outer peripheral surface of the photosensitive drum, the ozone adsorption member, and the second fan to the outside of the housing.

According to a seventh aspect of the present invention, a corona discharger is provided so as to face the photosensitive drum, and the ozone concentration in the atmosphere around the photosensitive drum is adjusted in accordance with the characteristics of the surface layer of the photosensitive drum. An image forming apparatus provided with an ozone concentration regulating device that regulates the ozone concentration to be equal to or less than a predetermined value, wherein the ozone concentration regulating device has a connection pipe having one end side surrounding a corona discharger and the other end side opening to a housing outer wall of the image forming apparatus. Comprising a breathable ozone adsorbing member and a fan provided in the connecting pipe,
An image forming apparatus, wherein air around a photosensitive drum is sucked and introduced into a connecting pipe by the fan, and is discharged out of the housing via the ozone adsorbing member.

Further, according to the present invention, a corona discharger is provided so as to face the photoconductor drum, and the ozone concentration in the atmosphere around the photoconductor drum is adjusted according to the characteristics of the surface layer of the photoconductor drum. An image forming apparatus provided with an ozone concentration regulating device for regulating the concentration to a predetermined value or less, wherein the ozone concentration regulating device is provided with an ozone adsorbing member surrounding a corona discharger.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram illustrating a main configuration of the color copying machine 1. The copying machine is an image recording unit (image forming unit) 2 which is a color printer,
The image reading unit 3 and the sheet feeding unit 4 which are color scanners are provided. Hereinafter, these contents will be described.

First, an image reading method by the image reading section 3 will be described. An image of the original on the contact glass is formed on a color sensor via an illumination lamp, a mirror group, a lens, and the like, and color image information of the original is separated into, for example, red (R), green (G), and blue (B). The light is read for each light and converted into an electric image signal. The color sensor is composed of R, G, B color separation means and a photoelectric conversion element such as a CCD, and simultaneously reads three color images obtained by color separation of an original image. The image processing unit performs color conversion processing based on the R, G, and B color separation image signal intensity levels obtained by the color scanner, and displays black (hereinafter, referred to as Bk) and yellow (hereinafter, referred to as Y). ), Shan (hereinafter, referred to as C) and magenta (hereinafter, referred to as M) color image data are obtained.

The operation of the color scanner for obtaining Bk, Y, C, M color image data will be described. In response to a scanner start signal that is timed with the operation of the image forming unit 2 described later, an optical system including an illumination lamp, a mirror group, and the like scans the document and obtains one color image data for each scan. By repeating this operation four times in total, for example, each color separation light of R, G, B is read, converted into an electric image signal, and stored in the memory. Based on the intensity levels of the R, G, and B color separated image signals obtained by the color scanner, a color conversion process is performed by an image processing unit.
k, Y, C, and M image data are obtained.

Next, the image forming section 2 will be described. The image forming unit 2 includes a photoconductor drum 100 as an image carrier, a charging unit 200, a photoconductor cleaning device 300, a revolver developing unit 400 as a developing unit, an intermediate transfer unit 500, and a secondary transfer unit 600. And a fixing unit 700 and a writing optical unit 800 as exposure means.

In the present embodiment, the photosensitive drum 100 is formed of an organic photosensitive member, and is actually formed by applying an organic lubricant such as zinc stearate to the surface thereof. In addition,
The lubricant is not limited to this, and a Teflon-based lubricant or an inorganic solid lubricant can also be used. The photosensitive drum 100 rotates counterclockwise as shown. Charging means 2
Reference numeral 00 denotes a charging charger 201, a discharging lamp 202, and the like. In the present embodiment, a corona charger (corona discharging device) that performs corona discharge is employed as the charging charger 201.

The photosensitive member cleaning device 300 includes a cleaning blade 301, a fur brush 302, a zinc stearate 303 as a lubricant, and the like. Polish the zinc stearate 303 with the fur brush 302,
The polished fine particles are applied to the surface of the photosensitive drum 100. The cleaning blade 301 removes toner and the like on the surface of the photosensitive drum 100, and
00 is prepared for reuse.

The revolver developing unit 400 includes a Bk developing device 401 using Bk toner, a Y developing device 402 using Y toner, a C developing device 403 using C toner,
An M developing unit 404 using toner and a developing revolver driving unit (not shown) for rotating the entire unit counterclockwise are provided. The toner in each of the developing devices 401 to 404 is negatively charged by stirring with the ferrite carrier.
A developing bias voltage is applied to a developing sleeve provided in each of the developing devices 401 to 404, and the developing sleeve is biased to a predetermined voltage with respect to the photosensitive drum 100.
In the standby state of the color copying machine 1, the Bk developing device 40
1 is stopped at the home position which is the developing position,
By the copy start, the photosensitive drum 100 starts reading the image data of the original, and the formation of the electrostatic latent image starts based on the color image data, thereby forming the Bk electrostatic latent image. At the same time, Y, C, and M electrostatic latent images are formed.

The intermediate transfer unit 500 is stretched between rollers such as a primary transfer bias roller 507, a belt drive roller 508, a belt tension roller 509, a secondary transfer opposing roller 510, a cleaning opposing roller 511, and an earth roller 512. Intermediate transfer belt 501
And a position detection mark MC disposed inside the circulation traveling path thereof, and an optical sensor 5 as a mark detection sensor.
14 Further, on the outer peripheral side of the intermediate transfer belt 501, a charge removing charger 503 and a cleaning plate 50 are provided.
4. Fur brush 505, zinc stearate 506, etc. are arranged. A primary transfer power supply 515 is connected to the primary transfer bias roller 507.

The secondary transfer unit 600 includes three support rollers 602, 603, and 604, and a secondary transfer belt 601 and the like stretched over the rollers. A secondary transfer bias roller 605 to which a secondary transfer power source 609 is connected is provided on the inner peripheral side of the secondary transfer belt 601, and a cleaning blade 608, a transfer paper static charger 606 and a static charger 607 are provided on the outer peripheral side. Are located.

The fixing section 700 includes a fixing roller 701 and the like. The fixing section 700 is disposed downstream of the secondary transfer unit 600 so that the toner image is melted and fixed, and is sent out by a discharge roller (not shown). Writing optical unit 80
Numeral 0 converts the color image data from the image reading unit 3 into an optical signal, and irradiates the surface of the photosensitive drum 100 uniformly charged by the charging charger 201 with a laser beam corresponding to the image of the document to emit light. Write to the photosensitive drum 1
The electrostatic latent image is formed on the surface of the image No. 00. The components include a semiconductor laser as a light source, a laser emission drive control unit, a polygon mirror and its rotation motor, an f / θ lens, a reflection mirror, and the like. The paper feed unit 4 is disposed on the upstream side of the secondary transfer unit 600 and transfers the transfer paper (P) to the secondary transfer unit 600 and the transfer unit 5.
00.

In the color copier 1 configured as described above, for example, when an A4 horizontal feed image forming cycle is started, the photosensitive drum 100 and the intermediate transfer belt 501 are primary-transferred to a primary transfer unit by a drive motor (not shown). Rotate at the same linear velocity as indicated by the arrow in the position. A position detection mark MC is provided on the back side of the intermediate transfer belt 501. The position detection mark MC is the intermediate transfer belt 50.
The optical sensor 514 is attached to the immovable member in a predetermined passage area that moves together with the position detection mark MC and passes the position detection mark MC. As the optical sensor 514, a reflection type photosensor or a transmission type photosensor is used. When a reflection type photo sensor is used as the optical sensor 514, a member such as a reflective tape is attached to the intermediate transfer belt 501, and the intermediate transfer belt 501 is reflected by the reflection type photo sensor.
What is necessary is just to read the place where the lower reflection surface changes to the position detection mark MC, or the place where the position detection mark MC changes to the lower reflection surface on the intermediate transfer belt 501. With the rotation of the intermediate transfer belt 501, two Bk toner images, two Y toner images, two C toner images,
Primary transfer bias roller 507 for forming two M toner images
, Primary transfer is performed by a transfer bias by a voltage applied to the intermediate transfer belt 501, and two toner images are finally formed on the intermediate transfer belt 501 in the order of Bk, Y, C, and M.

For example, the formation of a Bk toner image is performed as follows. The charging charger 201 uniformly charges the surface of the photosensitive drum 100 to a predetermined potential with negative charge by corona discharge. Position detection mark M by optical sensor 514
A certain time after the detection of C, the following Bk
Optical writing is performed using the image data. Then, based on the color image signal converted from the image data stored in the RGB memory, the writing optical unit 800 performs raster exposure with laser light of Bk data.
When this raster image is exposed, in the exposed portion of the surface of the photosensitive drum 100 that is initially uniformly charged, the charge proportional to the amount of exposure light disappears, and a Bk electrostatic latent image is formed.
When the negatively charged Bk toner on the Bk developing roller of the Bk developing device 401 comes into contact with the Bk electrostatic latent image,
The toner does not adhere to the portion of the photoconductor drum 100 where the charge remains, and the toner is attracted to the portion having no charge, that is, the exposed portion, and a Bk toner image similar to the electrostatic latent image is formed. The Bk toner image formed on the photosensitive drum 100 is transferred onto the surface of the intermediate transfer belt 501 that is driven at a constant speed in a state of contact with the photosensitive drum 100. Hereinafter, the transfer of the toner image from the photosensitive drum 100 to the intermediate transfer belt 501 is referred to as “primary transfer”.

A small amount of untransferred residual toner remaining on the surface of the photosensitive drum 100 after the belt transfer is cleaned by the photosensitive member cleaning device 300 in preparation for reuse of the photosensitive drum 100. In the photoconductor cleaning device 300, a fur brush 302 and a cleaning blade 30 are provided.
There is one. Zinc stearate 304 as a lubricant is provided on the back surface of the fabrush 302. The zinc stearate 303 is polished by the fur brush 302, and the polished fine particles are applied to the photosensitive drum 100. Similarly, each time the intermediate transfer belt 501 makes one rotation, the position detection mark MC is detected by the optical sensor 514, and the photoconductor drum 100 side performs the Bk image forming process at the same timing as Bk, that is, the optical sensor. 51
After a certain period of time from the detection of the position detection mark MC by No. 4, optical writing by Y image data, optical writing by C image data, and optical writing by M image data are respectively performed. When proceeding to the Y image forming step, the conversion of the Y image data converted from the RGB memory is started at a predetermined timing, and a Y electrostatic latent image is formed on the surface of the photosensitive drum 100 by writing the laser light with the Y image data. I do. Then, after the rear end of the previous Bk electrostatic latent image has passed and before the front end of the Y electrostatic latent image has arrived, the rotation operation of the revolver developing unit 400 is performed, and the Y developing device 402 Position, and the Y electrostatic latent image is developed with Y toner. Thereafter, development of the Y electrostatic latent image area is continued, but when the rear end of the Y electrostatic latent image passes, the revolver developing unit 400 is used in the same manner as in the case of the Bk developing machine 401 described above.
Is performed, and the next C developing device 403 is moved to the developing position. This is also completed before the leading end of the next C electrostatic latent image reaches the developing position. In the image forming processes of C and M, the operations of retrieving the color image data, forming the electrostatic latent image, and developing are the same as those of the above-described processes of Bk and Y, and thus the description is omitted.

On the intermediate transfer belt 501, Bk, Y, C, and M toner images sequentially formed on the photosensitive drum 100 are sequentially transferred to the same surface while being aligned. As a result, two screens of a toner image in which a maximum of four colors are superimposed are formed on the intermediate transfer belt 501. At the time when the image forming operation is started, the transfer paper P is fed from a paper supply unit such as a transfer paper cassette or a manual feed tray (not shown),
Secondary transfer facing roller 510 and secondary transfer bias roller 605 waiting at the nip of registration roller pair 650
Thus, before the leading end of the toner image on the intermediate transfer belt 501 reaches the secondary transfer portion where the nip is formed, the secondary transfer contact / separation CL operates, and the secondary transfer unit 600 comes into contact with the intermediate transfer belt 501. Thereafter, the registration roller pair 65 is moved so that the leading end of the transfer paper P coincides with the leading end of the toner image.
0 is driven, and registration of the transfer sheet P with the toner image is performed. Then, the transfer paper P is transferred to the intermediate transfer belt 501.
The sheet passes through the secondary transfer portion while being superposed on the upper toner image. At this time, the four-color superimposed toner image on the intermediate transfer belt 501 is collectively transferred onto the transfer paper by the transfer bias by the voltage applied to the secondary transfer bias roller 605 by the secondary transfer power supply 609. This is called “secondary transfer”.
Then, a transfer sheet static eliminator 606 disposed downstream of the secondary transfer portion in the moving direction of the secondary transfer belt 601.
When the paper P passes through the opposite portion, the transfer paper P is discharged, separated from the secondary transfer belt 601, and sent to the fixing roller 701.

The toner image is fused and fixed at the nip portion of the fixing roller 701, sent out of the apparatus main body by a discharge roller pair (not shown), and stacked face up on a copy tray (not shown) to obtain a full color copy. On the other hand, the surface of the photoconductor drum 100 after the belt transfer is cleaned by the photoconductor cleaning device 300 and is uniformly discharged by a discharge lamp (not shown). Further, the toner remaining on the surface of the intermediate transfer belt 501 after transferring the toner image onto the transfer paper P is cleaned by a cleaning blade 504 pressed against the intermediate transfer belt 501 by a contact / separation mechanism (not shown).

Here, at the time of the repeat copy, the operation of the color scanner and the image formation on the photosensitive drum 100 are as follows.
After the fourth sheet (M) image forming step of the first sheet, the process proceeds to the second sheet first color (Bk) image forming step at a predetermined timing. In the intermediate transfer belt 501, the second Bk toner image is transferred to the area of the front surface cleaned by the cleaning blade 504 following the batch transfer process of the first four-color superimposed toner image onto the transfer paper. The belt is transferred. Thereafter, the operation is the same as that of the first sheet. The above is the copy mode for obtaining a four-color full-color copy, but in the case of the three-color copy mode and the two-color copy mode,
The same operation as described above is performed for the designated color and the number of times. In the case of the single color copy mode, the revolver developing unit 400
Then, only the developing device of the predetermined color is set in the developing operation state, and the copying operation is performed while the cleaning blade 504 is kept pressed against the intermediate transfer belt 501.

In the color copying machine 1 as described above,
Ozone is generated around the photoreceptor drum 100 by corona charging along with the image forming operation. This ozone adversely affects the photoreceptor, causing image blur and the like. That is, when the ozone is generated, the resistance of the surface of the photosensitive drum 100 is reduced, and the electric charge that must be held as an electrostatic latent image flows, and the image is blurred (flows). Note that moisture (atmospheric humidity) is also involved in the reduction of the surface resistance, and the greater this is, the more remarkable.

[Experimental Example] When no special ozone concentration control means is provided, the ozone concentration in the atmosphere around the photosensitive drum 100 is about 30 ppm or more. Therefore, the above-mentioned image blur was observed while changing the ozone concentration experimentally. Normally, the photoconductor drum 100 is made of an organic photoconductor, and its surface is coated with a lubricant to improve photosensitivity. However, when a lubricant is applied, the adsorption of moisture is promoted, and image blur is likely to occur. Therefore, when applying a lubricant, it is necessary to regulate the ozone concentration particularly low.

The following Table 1 shows that an organic lubricant of zinc stearate was applied to the organic photosensitive drum, and the image blur was observed while changing the ozone concentration in a state where 800,000 sheets, which is the life of the photosensitive member, were run. The results are shown.

[0033]

[Table 1]

As shown in Table 1, the photosensitive drum 10
It was found that the image blur did not occur when the ozone concentration around 0 was 15 ppm or less. In addition, when the experiment was stopped with the application of zinc stearate being stopped under the above conditions, it was found that image blur did not occur when the ozone concentration was 25 ppm or less. From the above, in the case of the organic photoreceptor drum, the ozone concentration around the organic photoreceptor drum was 25 pp when no lubricant was applied.
m and less than 15 ppm when a lubricant was applied, it was found that image blurring did not occur by restricting each to less than 15 ppm.

As the lubricant, zinc stearate is used as described above, but the following may also be used. Those having a stearic acid group such as barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, and calcium stearate may be used. Further, zinc oleate, barium oleate, lead oleate, iron oleate, nickel oleate, cobalt oleate, copper oleate, strontium oleate, calcium oleate, and the like, which are the same fatty acid groups, may be used. Further, zinc palmitate, barium palmitate, lead palmitate, iron palmitate, nickel palmitate, cobalt palmitate, copper palmitate, strontium palmitate, calcium palmitate, or the like may be used. Further, as the fatty acid group, caprylic acid, linolenic acid, corinolenic acid and the like can be used. In addition, waxes such as candelilla wax, canrunau wax, rice wax, wood wax, amber oil, beeswax, and lanolin can be used. Since these are organic solid lubricants and have good compatibility with toner,
There is an advantage that it is easy to use. In addition, a Teflon-based or inorganic solid lubricant can be used, but it is possible to suppress insect biting with high accuracy.

Next, a description will be given of an ozone concentration regulating device for maintaining the ozone concentration in the atmosphere around the photosensitive drum 100 at the predetermined value of 25 ppm or less or 15 ppm or less.

As shown in FIG. 2, the ozone concentration regulating device 5
The connecting pipe 6 has one end surrounding the charging charger 201 and the other end opening to the outer wall of the housing of the color copying machine 1, the other end being close to the outer peripheral surface of the photosensitive drum 100 and the other end being the outer wall of the housing of the color copying machine 1. A connecting pipe 8 which is open to the inside, a fan 7 disposed on the opening side in the connecting pipe 6, and an ozone treatment filter (a gas-permeable ozone adsorbing member) disposed on the side of the connecting pipe 8 close to the photosensitive drum 100 ) 9 and a fan 10 and the like arranged on the opening side of the connecting pipe 8. The ozone treatment filter 9 is a well-known filter for absorbing generated ozone.

By operating the fan 7, outside air is introduced into the connection pipe 6, and this outside air acts to introduce ozone generated around the photosensitive drum 100 into the connection pipe 8. Ozone is adsorbed by an ozone treatment filter 9 in the connecting pipe 8, and the remaining ozone and air are discharged to the outside air by a fan 10. As described above, the photosensitive drum 1
The ozone concentration around 00 can be controlled, and the ozone concentration of 25 ppm or less or 15 ppm or less can be secured.

The ozone concentration regulating device 5a shown in FIG. 3 includes a connecting pipe 6a which surrounds the charging charger 201 at one end and opens the other end to the outer wall of the casing of the color copying machine 1, and the connecting pipe 6a.
a, an ozone treatment filter 9a, a fan 10a, etc. In the ozone concentration regulating device 5a, the photosensitive drum 100
Ozone around the photosensitive drum 100 can be controlled by sucking the surrounding ozone into the connecting pipe 6a and performing ozone adsorption processing with the ozone processing filter 9a.

The ozone concentration regulating device 5b shown in FIG. 4 comprises an ozone adsorber (ozone adsorbing member) 12 which is arranged so as to surround the charger 201, a support 11 holding the ozone adsorber 12, and the like. With the ozone concentration control device 5b having the above structure, substantially the same effects as those described above can be obtained. Ozone concentration control devices 5 and 5
Each of a and 5b is relatively simple, and can easily control the ozone concentration and can be implemented at low cost.

[0041]

As is clear from the above description, the following effects can be obtained according to the present invention. (1) In the image forming apparatus according to the first aspect, even if the type of the image carrier changes, the image blur is eliminated by regulating the ozone concentration in the surrounding atmosphere to a predetermined value or less. Can be. As described above, the present invention is not limited to a photosensitive drum made of a specific material, but can be applied to any and a wide range of image forming apparatuses. (2) In the image forming apparatus according to the second aspect, when the image carrier is an organic photoreceptor, the image blur can be eliminated by maintaining the ozone concentration in the atmosphere around the image carrier at 25 ppm or less. it can. (3) In the image forming apparatus according to the third aspect, the ozone concentration in the atmosphere around the image carrier is reduced to 15 pp even when a commonly used organic photosensitive drum coated with a lubricant is used.
By maintaining m or less, image blur can be eliminated. (4) According to the image forming apparatus of the fourth aspect, various lubricants can be applied, and the applicable range of the present invention is widened. (5) In the image forming apparatus according to the fifth aspect, a corona discharger is provided as a charging charger for the image carrier.
The present invention is widely applicable to ordinary image forming apparatuses.

(6) In the image forming apparatus according to claims 6 to 8,
Since the ozone concentration regulating device having a predetermined configuration is provided, the ozone concentration in the atmosphere around the image carrier can be accurately maintained at 25 ppm or less or 15 ppm or less.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a main part structure of a color copying machine according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing an example of an ozone concentration control device provided in the color copying machine of FIG. 1;

FIG. 3 is an explanatory view showing another example of the ozone concentration control device provided in the color copying machine of FIG. 1;

FIG. 4 is an explanatory view showing still another example of the ozone concentration control device provided in the color copying machine of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Color copier (image forming apparatus) 2 Image recording part (image forming part) 3 Image reading part 4 Paper feeding part 5, 5a, 5b Ozone concentration control device 6, 6a, 8 Connecting pipe 7, 10, 10a Fan 9, 9a Ozone treatment filter 11 Support 12 Ozone adsorber 100 Photoconductor drum 200 Charging means 201 Charging charger (corona discharger) 300 Photoconductor cleaning device 303 Zinc stearate 400 Revolver developing unit 500 Intermediate transfer unit 600 Secondary transfer unit 700 Fixing Unit 800 Writing optical unit

Claims (8)

[Claims] 1. An image forming apparatus, wherein an ozone concentration in an atmosphere around an image carrier is regulated to a predetermined value or less in accordance with characteristics of a surface layer of the image carrier. . 2. The image forming apparatus according to claim 1, wherein an organic photoconductor is provided as the image carrier, and the predetermined value is 25 ppm. 3. An organic photoreceptor having a surface coated with a lubricant is provided as the image carrier, and the predetermined value is set to 15 or less.
The image forming apparatus according to claim 1, wherein the amount is set to ppm. 4. The image forming apparatus according to claim 3, wherein the lubricant is an organic solid lubricant, a fluororesin lubricant, or an inorganic solid lubricant. 5. The corona discharger according to claim 1, wherein the ozone generating source causing the atmosphere around the image carrier to contain ozone is a corona discharge device provided to face the image carrier. Image forming apparatus. 6. A photovoltaic device in which a corona discharger is provided so as to face the photoreceptor drum, and the ozone concentration in the atmosphere around the photoreceptor drum is regulated to a predetermined value or less according to the characteristics of the surface layer of the photoreceptor drum. An image forming apparatus provided with a concentration regulating device, wherein the ozone concentration regulating device has a first connection pipe that surrounds a corona discharge device at one end and opens to the outer wall of the housing of the image forming device at the other end. A second connecting pipe which is close to the outer peripheral surface of the photoconductor drum and the other end side of which is open to the outer wall of the housing of the image forming apparatus; a first fan provided in the first connecting pipe; An air-permeable ozone adsorbing member provided therein and a second fan, wherein the outside air sucked by the first fan is provided around the corona discharger, the outer peripheral surface of the photosensitive drum, the ozone adsorbing member and the second fan. Discharge outside the body Image forming apparatus. 7. An ozone device which is provided with a corona discharge device facing the photoconductor drum and regulates an ozone concentration in an atmosphere around the photoconductor drum to a predetermined value or less in accordance with characteristics of a surface layer of the photoconductor drum. An image forming apparatus provided with a concentration regulating device, wherein the ozone concentration regulating device has a connecting pipe having one end side surrounding a corona discharger and the other end side opening to an outer wall of a housing of the image forming apparatus, and being provided in the connecting pipe. Air-permeable ozone adsorbing member and a fan, the air around the photosensitive drum is sucked and introduced into the connecting pipe by the fan,
An image forming apparatus, wherein the image is discharged outside the housing via the ozone adsorption member. 8. An ozone device which is provided with a corona discharger opposed to the photosensitive drum and regulates an ozone concentration in an atmosphere around the photosensitive drum to a predetermined value or less in accordance with characteristics of a surface layer of the photosensitive drum. An image forming apparatus provided with a concentration regulating device, wherein the ozone concentration regulating device includes an ozone adsorbing member surrounding a corona discharger.