JP2019078944A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus which can detect reduction in discharging performance of a discharging member through a simple method.SOLUTION: An image forming apparatus 1 includes: a photodetector 2; a charging member 3 for charging the photoreceptor 2; an exposure member 5 which exposes the photoreceptor 2 charged by the charging member 3 to from an electrostatic latent image on the photoreceptor 2; a developing member 6 which develops the electrostatic latent image formed on the photoreceptor 2 by the exposure member 5; a transfer member 7 for transferring an image developed on the photoreceptor 2 to a transfer body 8; a discharging member 9 which irradiates the photoreceptor 2 with discharging light with a set output, to remove the electrostatic latent image remaining on the photoreceptor 2; a charging current detection unit 11 which detects a charging current flowing in the charging member 3; and a performance determination unit 20 which determines reduction in discharging performance of the discharging member 9. The performance determination unit 20 determines reduction in discharging performance of the discharging member 9 on the basis of the charging current detected by the charging current detection unit 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus.

  In the image forming apparatus, when the toner image is formed on the photosensitive member, the toner image formed on the photosensitive member is transferred to the transfer belt or the recording medium by the transfer bias. Thereafter, the photosensitive member is irradiated with the charge removing light from the charge removing member, whereby the remaining potential remaining on the photosensitive member is erased (see, for example, Patent Documents 1 and 2).

  However, when the diselectrification capability of the diselectrification member is reduced due to the contamination of the diselectrification member due to the scattered toner or the like, or the light amount decrease of the diselectrification member due to aged deterioration, potential unevenness occurs on the photosensitive member and the printing quality is degraded. In order to cope with such a problem, Patent Document 1 arranges a transparent conductive electrode between the photosensitive member and the charge removing member, and detects the contamination of the charge removing member from the change in the detection value of the transparent conductive electrode. It is described.

Japanese Patent Application Laid-Open No. 05-035011

  However, in the technique described in Patent Document 1, since it is necessary to dispose a transparent conductive electrode between the photosensitive member and the charge removing member, there is a problem that the structure becomes complicated.

  An object of the present invention is to provide an image forming apparatus capable of detecting a decrease in the diselectrification capability of a diselectrifying member by a simple method.

  As a result of earnestly examining the above-mentioned subject, the present inventor found out the following knowledge. That is, when the output of the discharging member is increased, the charging current flowing to the charging member increases, and when the output of the discharging member exceeds a predetermined value, the charging current flowing to the charging member is saturated and substantially constant. Become. When the static elimination member is normal, the rate of increase of the charging current flowing to the charging member with respect to the rate of increase of the output of the static elimination member is substantially constant. However, if the diselectrification capability of the diselectrification member decreases, the rate of increase of the charging current flowing to the charging member with respect to the rate of increase of the output of the diselectrification member decreases. The present invention has been made based on the above findings.

  An image forming apparatus according to the present invention comprises a photosensitive body, a charging member for charging the photosensitive body, an exposure member for exposing the photosensitive body charged by the charging member to form an electrostatic latent image on the photosensitive body, and exposure The developing member for developing the electrostatic latent image formed on the photosensitive member by the member, the transfer member for transferring the image developed on the photosensitive member to the transfer body, and the photosensitive member are irradiated with static elimination light with setting output; It comprises: a charge removing member for removing an electrostatic latent image remaining on the photosensitive member; a charging current detection unit for detecting a charging current flowing to the charging member; and a performance determining unit for determining a decrease in charge removing capability of the charge removing member. The performance determination unit determines the decrease in the charge removal capability of the charge removal member based on the charging current detected by the charging current detection unit.

  As described above, when the charge removal member is normal, the increase rate of the charging current flowing to the charge member relative to the increase rate of the output of the charge removal member is substantially constant, but when the charge removal ability of the charge removal member decreases The increase rate of the charging current flowing to the charging member with respect to the increase rate of the output decreases. Therefore, by detecting the charging current flowing to the charging member, it is possible to appropriately determine the decrease in the discharging ability of the discharging member.

  In the above-described image forming apparatus, the performance determination unit operates the first charging current detected by the charging current detection unit when the discharging member is operated at the setting output, and the discharging member is operated at a comparison output smaller than the setting output. At this time, the decrease in the charge removing ability of the charge removing member may be determined by comparing the second charge current detected by the charge current detection unit. Usually, the setting output of the discharging member is set to an output larger than the output at which the charging current flowing to the charging member is saturated, in consideration of the occurrence of ghost and the like. Therefore, even if the discharging member is operated at the set output, it is difficult to determine the decrease in the discharging ability of the discharging member by the charging current flowing to the charging member until the discharging ability of the discharging member is significantly reduced. However, in this image forming apparatus, the first charging current detected by the charging current detection unit when the discharging member is operated at the setting output and the charging current detection when the discharging member is operated at the comparison output smaller than the setting output In order to compare with the 2nd charging current which the part detected, the fall of the static elimination capability of the static elimination member can be determined early.

  In the above-described image forming apparatus, the performance determination unit is configured to detect the third charging current detected by the charging current detection unit when the charge removal member is operated, and the fourth charging current detection unit when the exposure member is operated. The decrease in the charge removal ability of the charge removal member may be determined by comparing the charging current. When the diselectrification capability of the diselectrification member decreases, the charging current when the diselectrification member is operated decreases, but the charging current when the exposure member is activated hardly changes. Therefore, in this image forming apparatus, the third charging current detected by the charging current detection unit when the discharging member is operated, and the fourth charging current detected by the charging current detection unit when the exposure member is operated By comparison, it is possible to appropriately determine the decrease in the charge removal capability of the charge removal member.

  The image forming apparatus described above may further include a display device, and the performance determination unit may display a warning on the display device when determining that the charge removal capability of the charge removal member has decreased. In this image forming apparatus, by displaying a warning on the display device when it is determined that the charge removing capability of the charge removing member has decreased, it is possible to urge the user to clean the charge removing member, stop printing, or the like.

  In the above-described image forming apparatus, the image forming apparatus may further include a cleaning member that cleans the discharging member, and the performance determining unit may clean the discharging member by the cleaning member when it is determined that the discharging ability of the discharging member is reduced. In this image forming apparatus, the cleaning member is cleaned by the cleaning member when it is determined that the charge removal ability of the charge removal member is lowered, so the charge removal ability of the charge removal member is restored before the charge removal ability of the charge removal member is significantly reduced. be able to.

  In the above-described image forming apparatus, the performance determination unit stores the charging current detected by the charging current detection unit as a reference charging current when the process cartridge including the photosensitive member, the charging member, and the discharging member is installed. The reduction of the charge removal capability of the charge removal member may be determined by comparison with the charge current detected by the charge current detection unit. In this image forming apparatus, it is possible to appropriately determine the decrease in the diselectrification capability of the diselectrification member by comparing the stored reference charging current and the charging current detected by the charging current detection unit.

  In the above-described image forming apparatus, the performance determining unit may determine a decrease in the diselectrification capability of the diselectrifying member when the temperature or humidity of the environment in which the image forming apparatus is placed changes. In this case, when the temperature changes by 2 to 3 degrees and the humidity changes by 5%, the performance determining unit may determine the decrease in the charge removing capability of the charge removing member. The charge removal capacity of the charge removal member is susceptible to temperature or humidity. Therefore, in this image forming apparatus, when the temperature or humidity of the environment in which the image forming apparatus is placed changes, the deterioration of the charge removal ability of the charge removal member is determined to appropriately determine the decrease of the charge removal ability of the charge removal member. Can.

  In the above-described image forming apparatus, the performance determining unit may determine a decrease in the charge removing capability of the charge removing member when printing is continuously performed a predetermined number of times when the printing rate is equal to or more than a predetermined value. In this case, the performance determination unit may determine a decrease in the charge removal capability of the charge removal member when printing is continuously performed 200 times in which the printing rate is 20% or more. If printing with a printing rate equal to or higher than a predetermined value is continuously performed a predetermined number of times, the static elimination ability of the static elimination member tends to decrease. Therefore, in this image forming apparatus, when the printing rate at which the printing ratio is equal to or more than the predetermined value is continuously performed a predetermined number of times, the lowering of the static elimination ability of the static elimination member is judged to appropriately reduce the static elimination ability of the static elimination member. It can be determined.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the static elimination capability of the static elimination member can be detected by a simple method.

FIG. 2 is a view schematically showing the periphery of a photosensitive member of the image forming apparatus of the first embodiment. It is a graph which shows the relationship between the output of a static elimination member, and the charging current which flows into a charging member. 5 is a flowchart showing the processing operation of the image forming apparatus of the first embodiment. FIG. 7 is a view schematically showing the periphery of a photosensitive member of the image forming apparatus of the second embodiment. It is a flowchart which shows the processing operation of the image forming apparatus of 2nd embodiment. FIG. 14 is a view schematically showing the periphery of a photosensitive member of the image forming apparatus of the third embodiment. It is a flowchart which shows the processing operation of the image forming apparatus of 3rd embodiment. It is a figure which shows typically the photosensitive body periphery of the image forming apparatus of 4th embodiment. It is a flowchart which shows the processing operation of the image forming apparatus of 4th embodiment.

  Hereinafter, an image forming apparatus according to an embodiment will be described with reference to the drawings. The same or corresponding elements in the drawings will be denoted by the same reference symbols, without redundant description.

First Embodiment
As shown in FIG. 1, the image forming apparatus 1 according to the first embodiment includes a photosensitive member 2, a charging member 3, a charging power source 4, an exposure member 5, a developing member 6, a transfer member 7, and a transfer member. 8, the charge removal member 9, the cleaning member 10, the charging current detection unit 11, the display device 12, and the performance determination unit 20. In addition to the above, the image forming apparatus 1 has various known configurations required as an image forming apparatus.

  The photosensitive member 2 is a drum-shaped electrostatic latent image carrier (photosensitive drum) on which an image (toner) is formed on the circumferential surface. The photoreceptor 2 is made of, for example, an OPC (Organic PhotoConductor). The photosensitive member 2 is rotationally driven at a constant speed by a drive motor (not shown).

  The charging member 3 receives power supply from the charging power source 4 and uniformly charges the surface of the photosensitive member 2 to a predetermined potential. The potential charged on the surface of the photosensitive member 2 is not particularly limited, and can be, for example, 600 V. The charging member 3 is configured of, for example, a charging roller.

  The charging power source 4 supplies power to the charging member 3 by applying a voltage to the charging member 3.

  The exposure member 5 exposes the surface of the photosensitive member 2 charged by the charging member 3 in accordance with the image formed on the recording medium. As a result, the potential of the portion of the surface of the photosensitive member 2 exposed by the exposure member 5 changes, and an electrostatic latent image is formed.

  The developing member 6 develops the electrostatic latent image formed on the surface of the photosensitive member 2 by the toner supplied from a toner tank (not shown). Thereby, a toner image is formed on the surface of the photosensitive member 2.

  The transfer member 7 applies a transfer bias, which is a charge opposite to that of the toner, from the back side of the transfer body 8 (the side opposite to the photosensitive body 2). Thus, the toner image developed on the photosensitive member 2 is transferred to the transfer body 8.

  The transfer body 8 is a medium onto which the toner image is transferred from the photosensitive body 2 or a transfer belt or transfer roller onto which the toner image is primarily transferred from the photosensitive body 2. When the transfer body 8 is a transfer belt or a transfer roller to which a toner image is primarily transferred from the photosensitive body 2, the transfer body 8 is a secondary transfer member (not shown) to transfer the toner image primarily transferred from the photosensitive body 2. Secondary transfer to media.

  The discharging member 9 irradiates the photosensitive member 2 on which the toner image has been transferred to the transfer member 8 by the transfer member 7 with discharging light at a set output which is a set output (output value). The static elimination light is light for removing the residual potential remaining on the surface of the photosensitive member 2. Thus, the residual potential on the surface of the photosensitive member 2 is removed to prepare for the next image formation. In addition, if the output (power) of the static elimination member 9 becomes large, the irradiation intensity of the static elimination light which the static elimination member 9 irradiates will become large, and the static elimination effect will become large. On the other hand, when the output (power) of the static elimination member 9 becomes smaller, the irradiation intensity of the static elimination light emitted by the static elimination member 9 becomes smaller, and the static elimination effect becomes smaller. The static elimination member 9 is formed of, for example, an erase lamp (light emitting device) such as an LED or an El element.

  The cleaning member 10 collects toner (residual toner) remaining on the photosensitive member 2 even after the toner image is primarily transferred to the transfer member 8. The cleaning member 10 is formed of, for example, a cleaning blade that is in contact with the circumferential surface of the photosensitive member 2.

  The charging current detection unit 11 detects the charging current flowing to the charging member 3. The charging current detection unit 11 is configured of, for example, a current detector provided on an electrical wiring between the charging member 3 and the charging power source 4.

  The display device 12 is provided in a housing of the image forming apparatus 1 and displays the information instructed from the performance determination unit 20. The display device 12 may display various information of the image forming apparatus 1 in addition to the information instructed from the performance determination unit 20.

  The performance determination unit 20 determines the decrease in the charge removal capability of the charge removal member 9 based on the charging current detected by the charging current detection unit 11. The performance determination unit 20 can be realized as one function of a control device configured by a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like.

Here, the relationship between the output of the charge removing member 9 and the charging current flowing to the charging member 3 will be described with reference to FIG. In FIG. 2, the horizontal axis indicates the output of the charge removing member 9, and the vertical axis indicates the charging current flowing to the charging member 3. As shown in FIG. 2, when the output of the discharging member 9 is increased, the charging current flowing to the charging member 3 increases, and when the output of the discharging member 9 exceeds a predetermined value, the charging current flowing to the charging member 3 Becomes saturated and almost constant. When the static elimination member 9 is normal, as shown by the solid line A in FIG. 2, the increase rate of the charging current flowing in the charging member 3 with respect to the rise rate of the output of the static elimination member 9 is substantially constant. Therefore, assuming that the output of charge removing member 9 in which the charging current flowing to charging member 3 is saturated is output ER ₀ , the set output ER ₁ of charge removing member 9 is higher than output ER ₀ in view of ghosting and the like. It is set to a large value.

However, when the diselectrification capability of the diselectrification member 9 decreases, as shown by the broken line B in FIG. 2, the increase rate of the charging current flowing in the charging member 3 with respect to the increase rate of the output of the diselectrification member 9 decreases. Therefore, even when the output of the charge removing member 9 becomes output ER _0, charging current flowing through the charging member 3 is not saturated, even output of discharging member 9 are the same, discharging member 9 is normal Compared to the case, the charging current flowing to the charging member 3 is smaller.

Therefore, the performance determination unit 20 compares the first charging current CRi ₁ detected by the charging current detection unit 11 when the discharging member 9 is operated with the set output ER ₁ and the comparison output ER smaller than the setting output of the discharging member 9. By comparing the second charging current CRi ₂ detected by the charging current detection unit 11 when it is operated in ₂ , it is determined that the charge removing capability of the charge removing member 9 is lowered. Here, the charge removal ability of the charge removal member 9 is the ability to remove the residual potential remaining on the surface of the photosensitive member 2 by the charge removal member 9 irradiating the charge removal light. The decrease in the charge removing ability of the charge removing member 9 means that the residual potential remaining on the surface of the photosensitive member 2 can not be sufficiently removed. The reason why the charge removing ability of the charge removing member 9 is lowered is, for example, the stain of the erase lamp such as the LED and the El element constituting the charge removing member 9 and the decrease in the light amount due to the aged deterioration. In general, since the charge removal ability of the charge removal member 9 gradually decreases, the degree of decrease in the charge removal ability of the charge removal member 9 which is determined to have decreased is particularly limited. It may be set appropriately according to the design concept of the image forming apparatus 1 and the like.

Specifically, the performance determination unit 20, when the second charging current CRi ₂ smaller than the first charging current CRi _1, or the second charging current CRi ₂ is first charged current CRi setpoint than ₁ When it is smaller than the above, it is determined that the charge removing capability of the charge removing member 9 is lowered. Comparison output ER ₂ is preferably charged current flowing through the charging member 3 when discharging member 9 is normal is larger than the output ER ₀ to a saturated state. The setting value used to compare the second charging current CRi ₂ and the first charging current CRi ₁ takes into consideration the fluctuation error of the charging current, and can be an arbitrary value.

The performance determination unit 20 sets the charging current detected by the charging current detection unit 11 as a reference charging current CRi ₀ when a process cartridge (not shown) including the photosensitive member 2, the charging member 3, and the discharging member 9 is installed. It is also possible to determine the decrease in the diselectrification capability of the diselectrification member 9 by storing the first charge current CRi ₁ and the reference charge current CRi ₀ detected by the charge current detection unit 11 after that. Here, installation of the process cartridge may be, for example, when the new process cartridge is newly installed in the image forming apparatus 1 or when the process cartridge used in another image forming apparatus is replaced with the image forming apparatus 1. Thus, as an output ER ₀ following values comparison output ER _2, is compared with a first charging current CRi ₁ and a second charging current CRi ₂ and the reference charging current CRi _0, the charge removing member 9 It is possible to determine the decrease in the charge removal capability. For example, when the difference between the first charging current CRi ₁ and the second charging current CRi ₂ is larger than the difference between the first charging current CRi ₁ and the reference charging current CRi ₀ , or the second charging current CRi ₁ relative to the first charging current CRi ₁ If the ratio of the charging current CRi ₂ is smaller than the ratio of the reference charging current CRi ₀ to the first charging current CRi _1, it can be determined that the discharging ability of the discharging member 9 has decreased.

  Then, when the performance determining unit 20 determines that the charge removing capability of the charge removing member 9 has decreased, it causes the display device 12 to display a warning. The contents of the alarm to be displayed on the display device 12 include, for example, information indicating that the charge removing capability of the charge removing member 9 has decreased, and information for inquiring whether to continue printing or the like.

  Next, with reference to FIG. 3, a method of determining the decrease in the charge removing capability of the charge removing member 9 will be described. The processing illustrated in FIG. 3 is a processing operation performed by the control of the performance determining unit 20.

  The timing at which the performance determination unit 20 performs the processing operation to determine the decrease in the static elimination ability of the static elimination member 9 is not particularly limited, and may be performed periodically or at any time. . For example, the performance determination unit 20 may perform the above-described process to determine the decrease in the static elimination capacity of the static elimination member 9 when printing with a printing rate equal to or higher than a predetermined value is continuously performed a predetermined number of times. In this case, the performance determination unit 20 may perform the above-described process to determine the decrease in the static elimination capacity of the static elimination member 9 when printing with a printing rate of 20% or more is continuously performed 200 times. In addition, when the temperature or humidity of the environment in which the image forming apparatus 1 is placed changes, the performance determination unit 20 may perform the above-described processing to determine the decrease in the static elimination capacity of the static elimination member 9. In this case, when the temperature changes by 2 to 3 degrees and the humidity changes by 5%, the performance determining unit 20 may perform the above-described processing to determine the decrease in the static elimination capacity of the static elimination member 9. Specifically, when the temperature range and the humidity range are divided into a plurality, and the division corresponding to the temperature or humidity of the environment in which the image forming apparatus 1 is placed changes, the above processing is performed and the charge removal ability of the charge removal member 9 is The determination of the decrease may be made. The temperature range of one segment can be, for example, 2 to 3 degrees, and the humidity range of one segment can be, for example, 5%. The air temperature and humidity can be acquired by, for example, an air temperature sensor and a humidity sensor.

As shown in FIG. 3, performance determination unit 20 activates the charge removing member 9 at the set output ER ₁ (step S1), the then the charging current detection unit 11 obtains a first charging current CRi ₁ detected in ( Step S2). Also, performance determination unit 20 activates the charge removing member 9 in comparison output ER ₂ (step S3), and then the charging current detection unit 11 acquires a second charging current CRi ₂ detected (step S4). The process of step S1 and step S2 and the process of step S3 and step S4 may be performed in reverse or simultaneously.

Next, the performance determination unit 20 compares the first charging current CRi ₁ obtained in step S2 with the second charging current CRi ₂ obtained in step S4 to determine whether or not the discharging ability of the discharging member 9 is reduced. It is determined (step S5). In step S5, for example, the second charging current CRi ₂ whether less than the first charging current CRi _1, or whether the second charge current CRi ₂ smaller than the set value than the first charging current CRi ₁ Determine When it is determined that the second charging current CRi ₂ is not smaller than the first charging current CRi ₁ or the second charging current CRi ₂ is not smaller than the first charging current CRi ₁ by a set value or more, It is determined that the static elimination ability of No. 9 is not reduced. On the other hand, when it is determined that the second charging current CRi ₂ is smaller than the first charging current CRi ₁ or the second charging current CRi ₂ is smaller than the first charging current CRi ₁ by a set value or more, It is determined that the charge removal capability has decreased.

And (S5).

  And when it determines with the static elimination capability of the static elimination member 9 not falling (S5: NO), the performance determination part 20 complete | finishes a process. On the other hand, when it is determined that the charge removing capability of the charge removing member 9 has decreased (S5: YES), the performance determination unit 20 ends the process after displaying an alarm on the display device 12 (S6).

  As described above, when the discharging member 9 is normal, the increasing rate of the charging current flowing to the charging member 3 with respect to the rising rate of the output of the discharging member 9 is substantially constant, but the discharging ability of the discharging member 9 is lowered. Then, the rate of increase of the charging current flowing to the charging member 3 with respect to the rate of increase of the output of the static elimination member 9 is reduced. For this reason, in the image forming apparatus 1 according to the present embodiment, by detecting the charging current flowing to the charging member 3, it is possible to appropriately determine the decrease in the discharging ability of the discharging member 9.

Here, the set output ER ₁ static eliminating member 9, in view of the ghost occurrence, the charging current flowing to the charging member 3 is set to a value greater than the output ER ₀ to a saturated state. Therefore, even when operating the charge removing member 9 at the set output ER _1, until neutralization capacity of the discharging member 9 is greatly reduced, and determines a decrease in the neutralization capacity of the discharging member 9 by the charging current flowing to the charging member 3 It is difficult. However, in the image forming apparatus 1, less a first charging current CRi ₁ and charge removing member 9 charging current detector 11 detects when actuating the discharging member 9 at the set output ER ₁ than the set output ER ₁ Comparative In order to compare the second charging current CRi ₂ detected by the charging current detection unit 11 when the output ER ₂ is operated, it is possible to early determine the decrease in the static elimination ability of the static elimination member 9.

  Further, in the image forming apparatus 1, when it is determined that the charge removing ability of the charge removing member 9 is lowered, a warning is displayed on the display device 12 to prompt the user to clean the charge removing member 9 or stop printing. it can.

Further, in the image forming apparatus 1, the charge removal of the charge removing member 9 is performed by comparing the stored reference charging current CRi ₀ with the first charging current CRi ₁ and the second charging current CRi ₂ detected by the charging current detection unit 11. Deterioration of ability can be determined appropriately.

  Further, in the image forming apparatus 1, when the temperature or humidity of the environment in which the image forming apparatus 1 is placed changes, it is determined that the charge removing ability of the charge removing member 9 is lowered. Can be determined.

  Further, in the image forming apparatus 1, when the printing rate at which the printing rate is equal to or more than the predetermined value is continuously performed a predetermined number of times, the deterioration of the charge removal ability of the charge removal member 9 is determined. Can be properly determined.

Second Embodiment
Next, an image forming apparatus according to a second embodiment will be described. The image forming apparatus of the second embodiment is basically the same as the image forming apparatus of the first embodiment, and differs from the image forming apparatus of the first embodiment only in that the cleaning member is further provided. Therefore, in the following, only matters different from the image forming apparatus of the first embodiment will be described, and description of the same matters as the image forming apparatus of the first embodiment will be omitted.

  As shown in FIG. 4, an image forming apparatus 1A according to the second embodiment includes a photosensitive member 2, a charging member 3, a charging power source 4, an exposure member 5, a developing member 6, a transfer member 7, and a transfer member. 8, the charge removal member 9, the cleaning member 10, the charging current detection unit 11, the display device 12, the cleaning member 13, and the performance determination unit 20.

  The cleaning member 13 is a member that cleans the static elimination member 9. The cleaning member 13 is formed of, for example, a member that mechanically wipes the lens of the static elimination member 9 for emitting the static elimination light with a cloth or a belt. Then, when the performance determining unit 20 determines that the charge removing capability of the charge removing member 9 is lowered, the cleaning member 13 cleans the charge removing member 9.

  Next, with reference to FIG. 5, the determination method of the fall of the static elimination capability of the static elimination member 9 is demonstrated. The processing illustrated in FIG. 5 is a processing operation performed by the control of the performance determining unit 20. In addition, the timing which performs the said processing operation and determines the fall of the static elimination capability of the static elimination member 9 is the same as that of 1st embodiment.

As shown in FIG. 5, the performance determination unit 20 performs steps S1 to S4 as in the first embodiment, and the first charging current CRi ₁ obtained in step S2 and the second charging current CRi obtained in step S4. _It is determined by comparing with ₂ whether or not the diselectrification capability of the diselectrification member 9 has decreased (step S5).

  And when it determines with the static elimination capability of the static elimination member 9 not falling (S5: NO), the performance determination part 20 complete | finishes a process.

  On the other hand, when it is determined that the diselectrification capability of the diselectrification member 9 has decreased (S5: YES), the performance determining unit 20 determines whether the number of times of cleaning of the diselectrification member 9 by the cleaning member 13 is 0, that is, the cleaning member 13 It is determined whether the static elimination member 9 has not been cleaned or not (S7). If it is determined that the number of times of cleaning of the static elimination member 9 by the cleaning member 13 is 0 (S7: YES), the performance determination unit 20 causes the static elimination member 9 to be cleaned by the cleaning member 13 (S8), and the process ends. At this time, 1 is added to the number of times of cleaning of the static elimination member 9 by the cleaning member 13. On the other hand, when it is determined that the number of times of cleaning of the static elimination member 9 by the cleaning member 13 is not 0 (S7: NO), the performance determination unit 20 ends the process after displaying an alarm on the display device 12 (S6).

  As described above, in the image forming apparatus 1A of the present embodiment, the cleaning member 13 is cleaned by the cleaning member 13 when it is determined that the discharging ability of the discharging member 9 has decreased, so the discharging ability of the discharging member 9 is significantly large. Before being lowered, the charge removal capability of the charge removal member 9 can be restored.

Third Embodiment
Next, an image forming apparatus of the third embodiment will be described. The image forming apparatus according to the third embodiment is basically the same as the image forming apparatus according to the first embodiment, and the difference with the image forming apparatus according to the first embodiment is only the method of determining the decrease in the charge removing ability of the charge removing member. . Therefore, in the following, only matters different from the image forming apparatus of the first embodiment will be described, and description of the same matters as the image forming apparatus of the first embodiment will be omitted.

  As shown in FIG. 6, in the image forming apparatus 1B of the third embodiment, the photosensitive member 2, the charging member 3, the charging power source 4, the exposing member 5, the developing member 6, the transfer member 7, and the transfer member 8, the charge removal member 9, the cleaning member 10, the charging current detection unit 11, the display device 12, and the performance determination unit 21.

As described above, when the diselectrification capability of the diselectrification member 9 decreases, the charging current when the diselectrification member 9 is operated decreases. On the other hand, even if the diselectrification capability of the diselectrification member 9 is lowered, the charging current when the exposure member 5 is operated hardly changes. Therefore, the performance determination unit 21 detects the third charging current CRi ₃ detected by the charging current detection unit 11 when the discharging member 9 is operated, and the charging current detection unit 11 when the exposure member 5 is operated. By comparing the fourth charging current CRi ₄ with the fourth charging current CRi _4, it is determined that the charge removing capability of the charge removing member 9 is reduced. Here, the third charging current CRi ₃ detected by the charging current detection unit 11 when the discharging member 9 is operated operates only the discharging member 9 without operating the exposure member 5, and at this time the charging current It is the third charging current CRi ₃ detected by the detection unit 11. Further, the fourth charging current CRi ₄ detected by the charging current detection unit 11 when the exposure member 5 is operated operates only the exposure member 5 without operating the discharging member 9, and at this time, the charging current is detected It is the fourth charging current CRi ₄ detected by the unit 11.

Specifically, the performance judgment unit 21 first detects the charging current detection unit 11 when the charge removal member 9 is operated, as a comparison between the third charging current CRi ₃ and the fourth charging current CRi ₄ . The ratio between the three charging current CRi ₃ and the fourth charging current CRi ₄ detected by the charging current detection unit 11 when the exposure member 5 is operated is determined. The output when operating the discharging member 9 is preferably a value smaller than the setting output ER ₁ of the discharging member 9, and furthermore, the charging current flowing to the charging member 3 is saturated when the discharging member 9 is normal. It is preferable that the value is larger than the output ER ₀ which is in the state.

Next, the performance judgment unit 21 compares the obtained ratio with the reference ratio. The reference ratio is the third charging current CRi ₃ detected by the charging current detection unit 11 when the discharging member 9 is operated when the discharging member 9 is normal, and the charging current when the exposure member 5 is operated. It is a ratio to the fourth charging current CRi ₄ detected by the detection unit 11. The reference ratio is, for example, the third charging current CRi ₃ detected by the charging current detection unit 11 when a process cartridge (not shown) including the photosensitive member 2, the charging member 3, and the discharging member 9 is installed. The ratio to the fourth charging current CRi ₄ detected by the charging current detection unit 11 when the member 5 is operated can be set.

  The performance determining unit 21 determines that the static elimination ability of the static elimination member 9 has a change in the calculated ratio from the reference ratio, or in a case where the calculated ratio changes from the reference ratio by a predetermined value or more. It determines that it has fallen. The set value used for comparison with the reference ratio takes into consideration the fluctuation error of the charging current, and can be an arbitrary value.

  Next, with reference to FIG. 7, a method of determining the decrease in the charge removing capability of the charge removing member 9 will be described. The processing illustrated in FIG. 7 is a processing operation performed by the control of the performance determining unit 21. In addition, the timing which performs the said processing operation and determines the fall of the static elimination capability of the static elimination member 9 is the same as that of 1st embodiment.

As shown in FIG. 7, the performance determination unit 21 actuates the discharging member 9 (step S11), and then the charging current detection unit 11 obtains the third charging current CRi ₃ detected (step S12). Further, the performance determination unit 21 operates the discharging member 9 (step S13), and acquires the fourth charging current CRi ₄ detected by the charging current detection unit 11 at that time (step S14). The process of step S11 and step S12 and the process of step S13 and step S14 may be performed in reverse or simultaneously.

Next, the performance determination unit 21, by comparing the fourth charging current CRi ₄ obtained in the third charging current CRi ₃ and step S14 obtained in step S12, or neutralization capability of the discharging member 9 is lowered not It is determined (step S15). In step S5, for example, the ratio of the fourth charging current CRi ₄ obtained in the third charging current CRi ₃ and step S14 obtained in step S12, whether the varied from the reference ratio, or more than a predetermined value from the reference ratio Determine if it is fluctuating. The ratio of the fourth charging current CRi ₄ obtained in the third charging current CRi ₃ and step S14 obtained in step S12 is not changed from the reference ratio, or does not vary more than a predetermined value from the reference ratio When it determines with, it determines with the static elimination capability of the static elimination member 9 not falling. On the other hand, the ratio of the fourth charging current CRi ₄ obtained in the third charging current CRi ₃ and step S14 obtained in step S12, are varied from the reference ratio or fluctuating more than a predetermined value from the reference ratio When it determines with, it determines with the static elimination capability of the static elimination member 9 having fallen.

  And when it determines with the static elimination capability of the static elimination member 9 not falling (S15: NO), the performance determination part 21 complete | finishes a process. On the other hand, when it is determined that the charge removing capability of the charge removing member 9 has decreased (S15: YES), the performance determination unit 21 ends the process after displaying an alarm on the display device 12 (step S16).

As described above, when the diselectrification capability of the diselectrification member 9 decreases, the charging current when the diselectrification member 9 is operated decreases but the charging current when the exposure member 5 is activated hardly changes. Therefore, in the image forming apparatus 1B, the third charging current CRi ₃ detected by the charging current detection unit 11 when the discharging member 9 is operated, and the charging current detection unit 11 when the exposure member 5 is operated. By comparing with the fourth charging current CRi ₄ , it is possible to appropriately determine the decrease in the charge removing ability of the charge removing member 9.

Fourth Embodiment
Next, an image forming apparatus according to a fourth embodiment will be described. The image forming apparatus of the fourth embodiment is basically the same as the image forming apparatus of the third embodiment, and is different from the image forming apparatus of the third embodiment only in that it further includes a cleaning member. Therefore, in the following, only differences from the image forming apparatus of the third embodiment will be described, and description of the same matters as the image forming apparatus of the third embodiment will be omitted.

  As shown in FIG. 8, an image forming apparatus 1C according to the fourth embodiment includes a photosensitive member 2, a charging member 3, a charging power source 4, an exposing member 5, a developing member 6, a transfer member 7, and a transfer member. 8, the charge removal member 9, the cleaning member 10, the charging current detection unit 11, the display device 12, the cleaning member 13, and the performance determination unit 21.

  The cleaning member 13 is the same as the cleaning member 13 of the second embodiment, and is a member that cleans the static elimination member 9. Then, when the performance determination unit 21 determines that the charge removing capability of the charge removing member 9 is lowered, the cleaning member 13 cleans the charge removing member 9.

  Next, with reference to FIG. 9, the determination method of the fall of the static elimination capability of the static elimination member 9 is demonstrated. The processing illustrated in FIG. 9 is a processing operation performed by the control of the performance determining unit 21. In addition, the timing which performs the said processing operation and determines the fall of the static elimination capability of the static elimination member 9 is the same as that of 1st embodiment.

As shown in FIG. 9, the performance determination unit 21 performs steps S11 to S14 as in the third embodiment, and the third charging current CRi ₃ acquired in step S12 and the fourth charging current CRi acquired in step S14. By comparing with ₄ , it is determined whether or not the diselectrification capability of the diselectrification member 9 has decreased (S15).

  And when it determines with the static elimination capability of the static elimination member 9 not falling (S15: NO), the performance determination part 21 complete | finishes a process.

  On the other hand, when it is determined that the diselectrification capability of the diselectrification member 9 has decreased (S15: YES), the performance determining unit 21 determines whether the number of times of cleaning of the diselectrification member 9 by the cleaning member 13 is 0, that is, the cleaning member 13 It is determined whether the static elimination member 9 has not been cleaned or not (S17). If it is determined that the number of times of cleaning of the static elimination member 9 by the cleaning member 13 is 0 (S17: YES), the performance judgment unit 21 causes the static elimination member 9 to be cleaned by the cleaning member 13 (S18), and the process is ended. At this time, 1 is added to the number of times of cleaning of the static elimination member 9 by the cleaning member 13. On the other hand, when it is determined that the number of times of cleaning of the static elimination member 9 by the cleaning member 13 is not 0 (S17: NO), the performance determination unit 20 ends the process after displaying an alarm on the display device 12 (S16).

  As described above, in the image forming apparatus 1C of the present embodiment, when it is determined that the charge removing ability of the charge removing member 9 is lowered, the charge removing member 9 is cleaned by the cleaning member 13, whereby the charge removing ability of the charge removing member 9 is obtained. It is possible to restore the diselectrification capability of the diselectrification member 9 before it drops significantly.

  As mentioned above, although the suitable embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment. For example, arbitrary configurations or processes may be appropriately replaced between the embodiments.

  1, 1A, 1B, 1C: image forming apparatus, 2: photoconductor, 3: charging member, 4: charging power source, 5: exposure member, 6: developing member, 7: transferring member, 8: transferring member, 9: discharging Members, 10: cleaning members, 11: charging current detection units, 12: display devices, 13: cleaning members, 20, 21: performance determination units.

Claims (10)

A photoconductor,
A charging member for charging the photosensitive member;
An exposure member for exposing the photosensitive member charged by the charging member to form an electrostatic latent image on the photosensitive member;
A developing member for developing an electrostatic latent image formed on the photosensitive member by the exposure member;
A transfer member for transferring the image developed on the photosensitive member to a transfer member;
A charge removing member for applying a charge removing light to the photosensitive member at a setting output to remove an electrostatic latent image remaining on the photosensitive member;
A charging current detection unit that detects a charging current flowing to the charging member;
A performance determination unit that determines a decrease in the charge removal capability of the charge removal member;
The performance determination unit determines a decrease in the charge removal ability of the charge removal member based on the charging current detected by the charging current detection unit.
Image forming apparatus. The performance determination unit operates the first charging current detected by the charging current detection unit when the discharging member is operated with the set output, and the comparison operation when the discharging member is operated with a smaller comparison output than the set output The second charge current detected by the charge current detection unit is compared with the second charge current to determine the decrease in the charge removing ability of the charge removing member.
An image forming apparatus according to claim 1. The performance determination unit is configured to use a third charging current detected by the charging current detection unit when the discharging member is operated, and a fourth charging current detected by the charging current detection unit when the exposure member is operated. To determine the decrease in the charge removal capacity of the charge removal member by comparing
An image forming apparatus according to claim 1. Further comprising a display device,
The performance determination unit causes the display device to display a warning when it is determined that the charge removal capability of the charge removal member has decreased.
The image forming apparatus according to any one of claims 1 to 3. It further comprises a cleaning member for cleaning the charge removal member,
When the performance determining unit determines that the charge removing ability of the charge removing member is lowered, the cleaning member cleans the charge removing member.
The image forming apparatus according to any one of claims 1 to 4. The performance determination unit stores, as a reference charging current, the charging current detected by the charging current detection unit when a process cartridge including the photosensitive member, the charging member, and the discharging member is installed, and thereafter the charging is performed. The deterioration of the charge removing ability of the charge removing member is determined by comparison with the charging current detected by the current detecting unit,
The image forming apparatus according to any one of claims 1 to 5. The performance determination unit determines a decrease in the charge removal capability of the charge removal member when the temperature or humidity of the environment in which the image forming apparatus is placed changes.
The image forming apparatus according to any one of claims 1 to 6. The performance determination unit determines a decrease in the charge removal capability of the charge removal member when the temperature changes by 2 to 3 degrees and the humidity changes by 5%.
The image forming apparatus according to claim 7. The performance determination unit determines a decrease in the charge removal capability of the charge removal member when printing is continuously performed a predetermined number of times when the printing rate is equal to or more than a predetermined value.
The image forming apparatus according to any one of claims 1 to 8. The performance determining unit determines a decrease in the diselectrification capability of the diselectrifying member when printing is continuously performed 200 times in which the printing rate is 20% or more.
The image forming apparatus according to claim 9.

Images