JP2015203759A - image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to prevent chronological deterioration of a photoreceptor, while preventing afterimage from being generated due to discharge failure on any condition.SOLUTION: An image forming apparatus 99 includes: an image carrier 3 carrying an electrostatic latent image; charging means 23 for charging the image carrier 3 uniformly; write means 20 which writes the electrostatic latent image on the image carrier 3; developing means 7 which develops the electrostatic latent image formed on the image carrier 3; and discharge means 22 which discharges the image carrier 3 after transfer, with light irradiation. The discharge means 22 emits light to the vicinity of a charging position of the image carrier 3 charged by the charging means 23. The image forming apparatus 99 includes control means 5 for controlling the quantity of light form the discharge means 22, according to a thickness of the image carrier 3.

Description

  The present invention relates to a copying machine, a facsimile machine, a printer, and an image forming apparatus which is a multifunction machine having a plurality of these functions.

  Image formation in an electrophotographic image forming apparatus is generally performed by the following process. First, an electrostatic latent image is formed by performing writing processing by optical scanning or the like on an image carrier such as a photoconductor uniformly charged by a charging device, and the formed electrostatic latent image is developed by a developing device. Develop with Next, the visualized toner image is transferred from the image carrier to a transfer member such as a recording paper or an intermediate transfer member. Residual charges exist on the image carrier after the transfer process, and these residual charges are removed by a charge eliminating means such as a charge eliminating lamp.

  The reason why the image carrier is neutralized by the neutralizing means is as follows. In other words, the image carrier after the transfer process has a history of electrostatic latent images. In a state where this history exists, the potential of the image carrier is not easily uniform even after the uniform charging process by the charging device. When a subsequent image is formed on the image carrier in a state where the history of the electrostatic latent image remains, an afterimage of the previous image is generated in the solid portion of the image. In order to avoid the occurrence of such an afterimage, the image carrier after the transfer process is neutralized.

  2. Description of the Related Art Conventionally, for the purpose of suppressing an afterimage, a configuration is known in which a neutralizing bias is applied to a neutralizing member disposed in contact with or close to an image carrier by a neutralizing lamp method (for example, “Patent Document 1”, “Patent Document”). 2 ”and“ Patent Document 3 ”). Also, a configuration is known in which the charge removal amount during the image forming operation is made smaller than the charge removal amount after the image forming operation for the purpose of suppressing the afterimage and reducing the deterioration of the photoreceptor with time (see, for example, “Patent Document 4”). ). In addition, for the purpose of suppressing afterimages, a configuration is known in which sensitivity information of the photosensitive member is obtained, and the amount of light applied to the photosensitive member, such as a static elimination lamp light amount or a blank lamp light amount, is set according to the sensitivity of the photosensitive member (for example, (See Patent Document 5).

However, the conventional static elimination means has a problem that afterimages due to static elimination failures cannot be suppressed, and abnormal images are generated. Further, if the charge removal amount is increased in order to suppress the charge removal failure, there is a problem that the electrostatic fatigue of the photoconductor is accelerated and the deterioration of the photoconductor over time cannot be suppressed and the life of the photoconductor is shortened.
SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that solves the above-described problems and that can suppress the deterioration of a photoconductor over time while suppressing the occurrence of an afterimage due to poor charge removal under any conditions.

  The present invention includes an image carrier that carries an electrostatic latent image, a charging unit that uniformly charges the image carrier, a writing unit that writes an electrostatic latent image on the image carrier, and the image carrier. A developing unit that visualizes the electrostatic latent image formed thereon; and a discharging unit that discharges the image carrier after transfer by light irradiation. The discharging unit is configured to remove the image carrier by the charging unit. Control means for irradiating light toward the vicinity of the charging position and controlling the amount of light from the charge eliminating means in accordance with the film thickness of the image carrier.

  According to the present invention, it is possible to efficiently remove charges with a small amount of light and to prevent excessive charge removal to the image bearing member by irradiating the vicinity of the charging position with the neutralizing light corresponding to the film thickness of the image bearing member. . As a result, it is possible to provide both an afterimage reduction and electrostatic fatigue reduction, and to provide an image forming apparatus that suppresses the occurrence of afterimages over a long period of time.

1 is a schematic view of an image forming apparatus to which an embodiment of the present invention can be applied. It is the schematic of the process cartridge used for one Embodiment of this invention. It is the schematic explaining the afterimage generation | occurrence | production principle and the afterimage suppression effect to the charging nip part in one Embodiment of this invention. (A) Schematic diagram of a conventional process cartridge having no lubricant application structure (b) Schematic diagram of a process cartridge according to an embodiment of the present invention having no lubricant application structure. It is the schematic which shows transition of the residual potential in the conventional structure and the structure of this invention. It is the schematic which shows an example of the correction | amendment according to the working distance in one Embodiment of this invention. FIG. 6 is a diagram showing (a) film thickness wear amount of a photoconductor according to environmental conditions in an embodiment of the present invention; and (b) photoconductor film thickness wear amount according to an image area ratio. It is the schematic which shows the correction coefficient according to (a) correction coefficient according to environmental conditions in one embodiment of this invention, and (b) image area rate. It is the schematic which shows the relationship between the residual potential and transfer current value in one Embodiment of this invention. It is the schematic which shows an example of correction | amendment by the transfer electric current value and charging potential in one Embodiment of this invention. It is the schematic of the process cartridge used for the 2nd Embodiment of this invention.

  FIG. 1 shows an image forming apparatus to which the first embodiment of the present invention can be applied. In the figure, an image forming apparatus 99 includes four image forming units 1Y, 1C, 1M, and 1K for generating yellow (Y), cyan (C), magenta (M), and black (K) toner images. I have. The image forming units 1Y, 1C, 1M, and 1K are different only in that different color toners are used, and other configurations are the same. Here, the image forming unit 1Y will be described as an example.

  In FIG. 1, an optical writing unit 20 as writing means is disposed below the image forming unit 1. The optical writing unit 20 irradiates a photoconductor 3 as an image carrier included in the image forming unit 1 with laser light L based on image information. In the present embodiment, as an example of the configuration of the optical writing unit 20, the laser light L emitted from the light source is irradiated on the photosensitive member 3 through a plurality of lenses and mirrors while being deflected by the polygon mirror 21. In addition to this method, an LED array method may be used.

  FIG. 2 is an enlarged configuration diagram showing a process cartridge constituting the black (K) image forming unit 1K. The image forming unit 1K includes a charging roller 23K as a charging unit, a developing device 7K as a developing unit, a drum cleaning device 15K, a discharging lamp 22K as a discharging unit, and the like around the photoreceptor 3K. The photoreceptor 3K is configured by sequentially laminating an organic photosensitive layer and a surface layer on a peripheral surface of a drum-shaped conductive support, and the organic photosensitive layer is configured by a charge generation layer, a charge transport layer, and the like. Yes. The thickness of the charge transport layer is in the range of 10 to 40 μm, and may be appropriately selected according to the desired photoreceptor characteristics. Between the conductive support and the organic photosensitive layer in the photoreceptor 3K, as necessary. An undercoat layer may be formed.

  The charging roller 23K includes a cored bar that is a conductive support (not illustrated), a roller unit (not illustrated) that is coated around the longitudinal center of the cored bar, and an abutting unit (not illustrated) that is fixed to both longitudinal ends of the cored bar. It consists of a roller. A charging bias is applied to the cored bar from a power source (not shown). Then, a discharge occurs between the conductive roller portion and the photoconductor 3K through the charging gap, so that the photoconductor 3K is uniformly charged.

  The cleaning brush roller 236K disposed in the vicinity of the charging roller 23K has a metal cored bar and a brush roller unit made of a plurality of conductive fibers electrostatically flocked around the cored bar. The cleaning brush roller 236K scrapes off the toner from the roller portion by rotating in accordance with the rotation of the charging roller 23K while contacting the roller portion of the charging roller 23K by its own weight. A method in which the charging roller 23K and the cleaning brush roller 236K are brought into contact with the image forming area of the photoreceptor 3K may be employed. Further, a non-contact charging means such as a scorotron charger may be used.

  An electrostatic latent image is formed on the surface of the photoreceptor 3K uniformly charged by the charging roller 23K by optical scanning with the laser beam L, and then the photoreceptor 3K is a development region which is a position facing the developing device 7K. Enter. The developing device 7K develops the electrostatic latent image using a two-component developer (hereinafter referred to as a developer) containing a magnetic carrier and a non-magnetic toner (not shown). The developing device 7K includes a developing sleeve 12K having a magnet facing the photoreceptor 3K through an opening provided in the casing, and an agitator that feeds the developer contained in the developing sleeve 12K while stirring the developer. Part 9K. Further, the developing device 7K has a doctor blade 14K or the like whose tip is close to the developing sleeve 12K, and transfers the toner in the developer carried on the surface of the developing sleeve 12K to the photoreceptor 3K.

  The developing sleeve 12K is provided with a magnet roller (not shown), and the magnet roller has a plurality of magnetic poles that are sequentially arranged from the position facing the doctor blade 14K toward the rotation direction of the developing sleeve 12K. Each of these magnetic poles applies a magnetic force to the developer on the developing sleeve 12K at a predetermined position in the rotation direction. As a result, the developer sent from the stirring unit 9K is attracted to and carried on the surface of the developing sleeve 12K, and a magnetic brush is formed on the surface of the developing sleeve 12K along the lines of magnetic force. The formed magnetic brush is regulated to an appropriate layer thickness when passing through the position facing the doctor blade 14K as the developing sleeve 12K rotates, and then conveyed to the developing region facing the photoreceptor 3K. Then, the toner is transferred onto the electrostatic latent image by the potential difference between the developing bias applied to the developing sleeve 12K and the electrostatic latent image on the photoreceptor 3K, and the electrostatic latent image is visualized.

  The photosensitive member 3K on which the black toner image is formed on the surface by development by the developing device 7K enters the primary transfer nip portion for black with the primary transfer roller 45K as it rotates. In the primary transfer nip portion, the black toner image on the photoreceptor 3K is primarily transferred onto the front surface of the intermediate transfer belt 41.

  The surface of the photoreceptor 3K after passing through the primary transfer nip portion is discharged by the discharging lamp 22K and then enters a cleaning position by the drum cleaning device 15K. The drum cleaning device 15K includes an application brush roller 17K, a cleaning blade 18K, a solid lubricant 19K, a recovery coil 16K, and the like. The application brush roller 17K has a metal rotating shaft member and a brush roller portion made of a plurality of conductive fibers erected on the peripheral surface. The transfer residual toner scraped off by the cleaning blade 18K is transported to one end in the paper surface direction of FIG. 2 by the recovery coil 16 and discharged to the outside of the drum cleaning device 15K. Be contained.

  The application brush roller 17K scrapes off the lubricant from the solid lubricant 19K as it rotates, and then applies it to the surface of the photoreceptor 3K. By this coating, a film made of a lubricant powder is formed on the surface of the photosensitive member 3K, the adhesion between the photosensitive member 3K and the toner is weakened to improve the cleaning property, and the photosensitive member 3K and each member in contact with the photosensitive member 3K The service life of the photosensitive member 3K is extended by reducing the rubbing force. As solid lubricant 19K, zinc stearate, barium stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, magnesium stearate, zinc oleate, cobalt oleate, Examples thereof include fatty acid metal salts such as magnesium oleate and zinc palmitate, natural waxes such as carnauba wax, and fluorine-based resins such as polytetrafluoroethylene. The lubricant application configuration is not an essential requirement for the configuration of the present invention.

  Next, the afterimage generation principle and the afterimage suppression effect on the charging nip portion will be described with reference to FIG. As shown in FIG. 3A, in the exposure process, the photoreceptor surface potential Vd is the exposure potential VI in the image portion and the charging potential Vd in the non-image portion. In the transfer process, as shown in FIG. 3B, the surface potential of the photosensitive member remains VI at the solid portion of the image where the toner is moved. On the other hand, in the non-image portion, a positive charge is injected into the photoconductor due to the transfer bias applied in the transfer process, so the photoconductor surface potential is positively charged. When the charging process is started in this state, as shown in FIG. 3C, the charging potential is lowered in the non-image portion due to the positive charge on the surface of the photoreceptor injected in the transfer process. When a subsequent image is formed on the photoconductor with the history of the electrostatic latent image remaining, an afterimage corresponding to the magnitude of the afterimage potential ΔVd is generated on the solid portion of the image. (In the case of the figure, the image density of the portion corresponding to the solid portion of the previous image becomes light). The amount of positive charge injected in the transfer process increases as the transfer current value increases, and the afterimage potential ΔVd tends to increase and the afterimage tends to deteriorate. Also, the lower the charging potential Vd (the smaller the absolute value), the larger the afterimage potential ΔVd, and the afterimage tends to deteriorate.

  Next, the reason why neutralizing light irradiation to the charging nip portion is effective will be described. When the photosensitive member is irradiated with static elimination light, negative charge (electrons) and positive charge (holes) are generated in the charge generation layer (CGL layer) as shown in FIG. When the charging process is started in this state, the positive charge generated in the charge generation layer moves to the surface of the photoconductor due to the electric field generated by the negative charge on the surface of the photoconductor. In the non-image area, the charge potential is lowered due to the positive charge on the surface of the photoconductor injected in the transfer process, so that the electric field is weakened, and the positive charge generated by the irradiation of the static elimination light is difficult to move to the photoconductor surface. On the other hand, in the image portion, positive charges are not generated in the transfer process and the electric field is strong. Therefore, as shown in FIG. 3E, the positive charges generated by the irradiation of the static elimination light easily move to the surface of the photoreceptor. Therefore, as shown in FIG. 3 (f), the potential difference ΔVd ′ between the image portion and the non-image portion is smaller (ΔVd ′ <ΔVd) than when there is no static elimination light (state in FIG. 3C). The afterimage improves.

  In addition, even if the charge removal light is irradiated before the charging nip part where no charging bias is applied, the positive charge generated by the charge removal light does not easily move to the surface of the photoconductor because no electric field is applied. small. Further, since the positive charge generated in the charge generation layer by the charge removal light disappears with the passage of time, irradiating the charge nip portion to which an electric field is applied is effective in reducing the afterimage.

  FIG. 4A shows a process cartridge 2K constituting a conventional image forming unit having no lubricant, and FIG. 4B shows a process cartridge 4K constituting an image forming unit of the present invention having no lubricant. ing. As described with reference to FIG. 3, in order to suppress the occurrence of an afterimage, in the conventional process cartridge 2K, it is necessary to increase the charge removal amount L 'of the charge removal lamp in order to increase the irradiation to the charging nip portion. However, when the amount of static elimination light L 'is increased, the occurrence of afterimages is suppressed, but there is a problem that the deterioration of the photoreceptor due to electrostatic fatigue is accelerated and the life is shortened.

  In the case of the conventional process cartridge 2K shown in FIG. 4A, since the film thickness variation is larger than that of the process cartridge 1K having a lubricant, it is necessary to irradiate the charge removal amount corresponding to the film thickness. However, in the conventional configuration, the amount of charge removal cannot be easily changed according to the film thickness of the photoreceptor. Therefore, in the process cartridge 4K of the present invention, as shown in FIG. 4B, the discharge lamp (light quantity L′ 1) is irradiated aiming at the charging nip portion. At this time, the light amount L'1 is changed according to the film thickness of the photosensitive member, and is controlled by the control means 5 so as to be an appropriate light amount that does not generate an afterimage. As a means for detecting the film thickness of the photosensitive member, for example, an electrically measuring device disclosed in Japanese Patent Laid-Open No. 8-86607 can be cited. In accordance with the detection result of the detection means, the control means 5 controls the amount of charge removed from the light quantity L′ 1.

  FIG. 5 shows the transition of the residual potential in the conventional configuration and the configuration of the present invention. In the configuration of the present invention, an appropriate amount of light can be provided as compared with the conventional configuration, so that the residual potential with the same amount of light can be maintained over time, and deterioration of the photoconductor over time is suppressed.

  As described above, since the electrostatic capacitance changes according to the film thickness of the photoconductor, the optimal charge removal amount that suppresses the occurrence of an afterimage changes according to the film thickness. In particular, in the configuration in which the lubricant is not applied, the amount of abrasion on the surface of the photoconductor is large. Therefore, it is impossible to achieve both afterimage suppression and suppression of deterioration of the photoconductor with time unless the amount of charge removal is changed according to the film thickness. Therefore, the film thickness of the photosensitive member can be trimmed in proportion to the working distance, so that the intensity of the light quantity L′ 1 irradiated toward the charging nip portion in the process cartridge 4K shown in FIG. Change accordingly. Such correction according to the working distance is advantageous in terms of downsizing and cost reduction as compared with the configuration having the above-described means for detecting the film thickness.

  Here, an example of correction according to the working distance will be described. For example, the intensity of the amount of light L′ 1 irradiated toward the charging nip portion can be controlled in three stages from Level 1 to Level 3. In this case, as shown in FIG. 6, the intensity of the light quantity L′ 1 is set to Level 1 at the working distance of 0 to 10 km, the intensity of the light quantity L′ 1 is set to Level 2 at the working distance of 10 to 20 km, and the light quantity at the working distance of 20 km or more. Change the strength of L'1 to Level3. Note that the strength of the charge removal amount L′ 1 is Level1> Level2> Level3.

  As in the process cartridge 2K shown in FIG. 4A, when the amount of charge removed to the area other than the charging nip is increased, the deterioration of the photosensitive member with time is accelerated. However, in the process cartridge 4K shown in FIG. The intensity of the static elimination light irradiated only on the head is changed. As a result, it is possible to suppress the deterioration of the photoreceptor over time and to suppress the occurrence of afterimages.

  FIG. 7A is a diagram showing the film thickness wear amount of the photoconductor according to the environmental conditions, and FIG. 7B is a diagram showing the film thickness wear amount of the photoconductor according to the image area ratio. As shown in FIG. 7 (a), the film thickness wear amount of the photoconductor is higher in the middle temperature / humidity environment (MM) than in the high temperature / high humidity environment (HH), and in the lower temperature / humidity environment than in the middle temperature / humidity environment ( LL) and more. This is because the edge of the cleaning blade is harder in a low-temperature and low-humidity environment than in a high-temperature and high-humidity environment, resulting in an increased amount of wear. Further, as shown in FIG. 7B, the film thickness wear amount of the photosensitive member is larger when the sheet is passed at a high image area ratio than when the sheet is passed at a low image area ratio. This is because the additive contained in the toner acts like an abrasive, and the amount of wear on the film increases with a high image area ratio with a large amount of residual toner and a large amount of toner entering the cleaning blade. .

  As described above, the film thickness wear amount of the photoreceptor varies depending on the environmental conditions and the image area ratio. Therefore, an example in which the working distance of the photoreceptor is corrected according to each environmental condition and the image area ratio and the intensity of the charge removal amount L′ 1 is changed will be described below. As shown in FIG. 6, the intensity of the static elimination light quantity L′ 1 is changed in accordance with the working distance. Here, the working distance D used for correcting the static elimination light quantity L′ 1 is set as the environmental condition and the image. Correct according to the area ratio.

  FIG. 8A shows a list of correction coefficients according to the environmental conditions, and FIG. 8B shows a list of correction coefficients according to the image area ratio. The image forming apparatus 99 is provided with a temperature / humidity sensor (not shown), and the environment in which it is used is recorded in a CPU (not shown). If it is used in a low-temperature and low-humidity environment, the edge of the cleaning blade becomes hard and the film thickness wear amount of the photosensitive member increases as described above. Therefore, the value of D ′ obtained by multiplying the operating distance D by 1.1 is the CPU. Saved in. Conversely, when used in a high-temperature and high-humidity environment, the edge of the cleaning blade is bent and the amount of film wear on the photoconductor is reduced, so the value of D ′ obtained by multiplying the working distance D by 0.9 is stored in the CPU. Is done. The same applies to the image area ratio. In the case of a high image area ratio, the value of D ′ obtained by multiplying the working distance D by 1.1, and in the case of the low image area ratio, D is obtained by multiplying the working distance D by 0.9. Each value of 'is stored in the CPU.

  Temporarily, 2 km of paper is passed under a high temperature and high humidity environment and an image area ratio of 0.5%, and 10 km of paper is passed under an intermediate temperature and humidity environment and an image area ratio of 20%. Consider the case of passing paper. In this case, D ′ = 2 km × 0.9 × 0.9 + 10 km × 1 × 1.1 + 3 km × 1.1 × 1 = 1.62 km + 11 km + 3.3 km = 15.92 km. In this way, by correcting the travel distance D used for correcting the charge removal light amount, it is possible to set the charge removal light amount L′ 1 in consideration of the environmental condition and the film thickness variation of the photoconductor due to the image area ratio. Note that the correction coefficient is not limited to the above because it changes according to the characteristics of the photoreceptor, the system configuration, and the like.

  As shown in FIG. 9A, the afterimage potential (the surface potential difference between the non-image area and the image area of the photoconductor, see FIG. 3C) tends to increase as the transfer current value increases. This is because the amount of positive charge injected in the transfer process increases as the transfer current value increases. Further, as shown in FIG. 9B, the afterimage potential tends to increase as the charging potential decreases. This is because the influence of the amount of positive charges injected in the transfer process becomes larger as the charging potential is smaller (smaller negative charges are smaller). Even if the same positive charge amount is applied, if the original negative charge amount is large, the positive charge hardly remains on the surface of the photoreceptor, and an afterimage hardly occurs.

  Even with the same photoconductor film thickness, the magnitude of the afterimage potential changes depending on the transfer current value and the charging potential, so that the optimum amount of charge removal for suppressing the occurrence of the afterimage changes depending on the transfer current value and the charging potential. This assumes a case where the transfer current value and the charging potential are changed to keep the toner adhesion amount constant when the image forming conditions change due to external factors.

  Therefore, in the process cartridge 4K of the present invention shown in FIG. 4B, the intensity of the light amount L'1 irradiated toward the charging nip portion varies depending on the transfer current value and the charging potential. As a result, under conditions in which afterimages are likely to occur (transfer current value is large and charging potential is low), even afterimages with poor levels are suppressed by increasing the amount of charge removal. On the contrary, under conditions where an afterimage is unlikely to occur (low transfer current value, high charging potential), the photoconductor fatigue can be suppressed by reducing the amount of static elimination, and deterioration of the photoconductor over time can be suppressed. FIG. 10A and FIG. 10B show an example of correction based on the transfer current value and the charging potential. Here, the intensity of the charge removal amount is Level1> Level2> Level3.

  According to the above-described configuration, it is possible to efficiently remove charges with a small amount of light and to prevent excessive charge removal to the photosensitive member by irradiating the charging nip portion with the removing light corresponding to the film thickness of the photosensitive member. As a result, it is possible to provide both an afterimage reduction and electrostatic fatigue reduction, and to provide an image forming apparatus that suppresses the occurrence of afterimages over a long period of time. It is also appropriate to omit the film thickness detecting means by estimating the film thickness from the working distance by estimating the film thickness from the working distance by estimating the film thickness from the working distance of the photosensitive member and controlling the light quantity L′ 1 from the static eliminating means. It is possible to irradiate with a static elimination light amount. As a result, it is possible to provide an image forming apparatus that is low in cost and suppresses the occurrence of afterimages over a long period of time and has a long lifetime. In addition, by controlling the light quantity L′ 1 from the static eliminating unit according to the environmental conditions, the image area of the electrostatic latent image, the transfer current value, and the photosensitive member charging potential, it is appropriate according to the film thickness estimated from each condition. It is possible to irradiate with a sufficient amount of static elimination. Accordingly, it is possible to provide an image forming apparatus that suppresses the occurrence of afterimages over a long period of time and has a long lifetime.

  FIG. 11 shows a process cartridge 6K used in the second embodiment of the present invention. This process cartridge 6K is different from the process cartridge 4K shown in the first embodiment only in that it has two or more (two in this embodiment) static elimination lamps, and the other configurations are the same. is there. One of the charge removal lamps of the process cartridge 6K is irradiated toward the charging nip portion near the charging position (light quantity L'1), and the other is irradiated toward the photosensitive member surface (light quantity L'2). At this time, similarly to the first embodiment, the light amount L′ 1 is changed according to the film thickness of the photosensitive member, and is controlled by the control means 5 so as to obtain an appropriate light amount that does not generate an afterimage. Thereby, while being able to obtain the same operation effect as 1st Embodiment, it can perform static elimination efficiently with less static elimination light quantity than when the static elimination means is 1 by having two or more static elimination means, Electrostatic fatigue can be further reduced.

  Also in the second embodiment, similarly to the first embodiment, the film thickness is calculated from the working distance by estimating the film thickness from the working distance of the photosensitive member and controlling the light quantity L′ 1 from the static eliminating means. By estimating, it is possible to irradiate an appropriate amount of static elimination light even if the film thickness detection means is omitted. As a result, it is possible to provide an image forming apparatus that is low in cost and suppresses the occurrence of afterimages over a long period of time and has a long lifetime. In addition, by controlling the light quantity L′ 1 from the static eliminating unit according to the environmental conditions, the image area of the electrostatic latent image, the transfer current value, and the photosensitive member charging potential, it is appropriate according to the film thickness estimated from each condition. It is possible to irradiate with a sufficient amount of static elimination. Accordingly, it is possible to provide an image forming apparatus that suppresses the occurrence of afterimages over a long period of time and has a long lifetime.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments described above, and is described in the claims unless specifically limited by the above description. Various modifications and changes can be made within the scope of the present invention.
For example, the image forming apparatus to which the present invention is applied is not limited to the type of image forming apparatus described above, and may be another type of image forming apparatus. In other words, the image forming apparatus to which the present invention is applied may be a printer, a single facsimile, or a complex machine thereof, or a complex machine such as a monochrome machine or a color machine related thereto. In addition, the image forming apparatus to which the present invention is applied may be an image forming apparatus used for forming an electric circuit or an image forming apparatus used for forming a predetermined image in the biotechnology field.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention. .

3 Image carrier (photoconductor)
5 Control means 7 Developing means (developing device)
20 Writing means (optical writing unit)
22 Static elimination means (static elimination lamp)
23 Charging means (charging roller)
99 Image forming apparatus

Japanese Patent No. 2618009 JP 2000-181159 A JP 2000-66552 A JP 2009-31488 A JP-A-6-118757

Claims (7)

An image carrier for carrying an electrostatic latent image;
Charging means for uniformly charging the image carrier;
Writing means for writing an electrostatic latent image on the image carrier;
Developing means for visualizing the electrostatic latent image formed on the image carrier;
Neutralizing means for neutralizing the image carrier after transfer by light irradiation,
The neutralizing unit irradiates light toward the vicinity of the charging position of the image carrier by the charging unit, and includes an image forming apparatus having a control unit that controls the amount of light from the neutralizing unit according to the film thickness of the image carrier. . The image forming apparatus according to claim 1.
2. An image forming apparatus comprising: two or more charge eliminating units, at least one of which irradiates light toward the vicinity of a charging position of the image carrier by the charging unit. The image forming apparatus according to claim 1 or 2,
The image forming apparatus characterized in that the control means estimates the film thickness from the working distance of the image carrier and controls the amount of light from the charge eliminating means. The image forming apparatus according to any one of claims 1 to 3,
The image forming apparatus according to claim 1, wherein the control unit controls the amount of light from the charge eliminating unit according to an environmental condition. The image forming apparatus according to any one of claims 1 to 4,
The image forming apparatus according to claim 1, wherein the control unit controls a light amount from the charge eliminating unit in accordance with an image area of the electrostatic latent image. The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein the control unit controls the amount of light from the charge eliminating unit in accordance with a transfer current value. The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein the control unit controls the amount of light from the charge eliminating unit in accordance with a photosensitive member charging potential.

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