JP6680247B2 - Image forming device - Google Patents

Description

  The present invention relates to an image forming apparatus including an organic photoconductor drum.

In the image forming apparatus for charging the organic photoconductor drum with a corona charger, ozone, SOox, discharge products such as NO _X adheres to the surface of the photosensitive drum. Since this discharge product is ionized by corona discharge during charging, the surface potential of the organic photoconductor drum is changed by the transfer current when the toner image carried on the organic photoconductor drum is transferred to the sheet. For example, when the toner image is transferred by applying a negative polarity bias to the organic photosensitive drum by a corona charger and applying a negative bias, the negative charge at the time of transfer from the portion where the discharge product is ionized is organic. It is injected into the photosensitive layer of the photosensitive drum. Therefore, in the organic photosensitive drum, the surface potential of the portion where the negative charges are injected into the photosensitive layer is lowered. Such a decrease in surface potential causes deterioration in image quality due to image deletion, white stripes, and the like.

  Further, in order to prevent the occurrence of image deletion due to discharge products, an image forming apparatus has been proposed that forms an electrostatic latent image on the photoconductor drum while avoiding a defective area on the photoconductor drum to which the discharge product may be attached. (See, for example, Patent Document 1).

JP 2012-189681 A

  However, when an electrostatic latent image is formed on the photoconductor drum while avoiding the defective area, the defective area is specified, and then the timing at which the defective area passes through the exposure device is specified to expose the defective area. Need to stop. Further, when the exposure in the defective area is stopped, a void area in which a toner image is not formed is formed corresponding to the defective area. Therefore, when the toner image is transferred to the sheet, it is necessary to specify the timing at which the missing area faces the sheet and stop the movement of the sheet at that timing. As described above, in the method of forming the electrostatic latent image on the photosensitive drum while avoiding the defective area, the control in the image forming process becomes complicated.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of suppressing deterioration of image quality due to discharge products attached to an organic photoconductor drum without complicating control in image forming processing.

  An image forming apparatus according to one aspect of the present invention includes an organic photosensitive drum, a charging unit, a charge eliminating unit, a first acquisition processing unit, a second acquisition processing unit, a light amount calculation processing unit, and a charge elimination control unit. The organic photosensitive drum is rotatably supported and carries toner. The charging unit charges the surface of the organic photoconductor drum by using corona discharge. The charge removing unit irradiates the surface of the organic photoconductor drum with charge removing light to remove charges on the surface of the organic photoconductor drum and lower the potential. The first acquisition processing unit acquires a charging time during which a charging process is performed on the surface of the organic photosensitive drum by the charging unit in the image forming process on the sheet. The second acquisition processing unit acquires a pause time during which the image forming process is paused. The light amount calculation processing unit, based on the charging time acquired by the first acquisition processing unit and the pause time acquired by the second acquisition processing unit when an image formation request is made, The light amount of the static elimination light emitted from the static elimination unit is calculated. The static elimination control unit controls driving of the static elimination unit in order to cause the static elimination light of the light amount calculated by the light amount arithmetic processing unit to be emitted from the static elimination unit.

  According to the present invention, it is possible to provide an image forming apparatus capable of suppressing a deterioration in image quality due to a discharge product attached to an organic photoconductor drum without complicating control in an image forming process.

FIG. 1 is a sectional view schematically showing an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration around the image forming unit of the image forming apparatus of FIG. FIG. 3 is a block diagram of the image forming apparatus of FIG. FIG. 4 is a static elimination light amount table stored in the image forming apparatus of FIG. FIG. 5 shows an example of changes over time in the surface potential of the organic photoconductor drum after charging the organic photoconductor drum to which the discharge products are attached, before transfer, during transfer, and after transfer. FIG. 6 shows an example of changes over time in the surface potential of the organic photoconductor drum before and after the charging process when the static elimination process is performed on the organic photoconductor drum to which the discharge products are attached. FIG. 7 is a flowchart showing the procedure of the image formation request time process executed by the control unit of the image forming apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are merely examples embodying the present invention, and the embodiments of the present invention can be appropriately modified without departing from the scope of the present invention.

  The image forming apparatus 10 shown in FIG. 1 has a scanner function of reading an image from a document and a printer function of forming a color image or a monochrome image on a sheet by an electrophotographic method using toner.

  The image forming apparatus 10 includes an ADF 11, an image reading unit 12, an image forming unit 13, a paper feed tray 14, a paper discharge tray 15, and a control unit 5.

  The ADF 11 is an automatic document feeder that feeds a document set in a document setting unit (not shown) to a position where the image reading unit 12 reads image data and conveys the document. The image reading unit 12 can read an image from a document set on a contact glass (not shown) or a document conveyed by the ADF 11.

  The image forming unit 13 forms an image on a sheet. The image forming unit 13 includes a plurality of image forming units 2 each having an organic photosensitive drum 21 carrying a toner image, an intermediate transfer belt 31, an exposure device 32 (an example of the exposure unit of the present invention), a secondary transfer roller 33, and a fixing unit. A device 34 is provided.

  As shown in FIGS. 1 and 2, each of the image forming units 2 includes an rotatably supported organic photosensitive drum 21, a scorotron 22 (an example of the charging unit of the present invention), and a developing device 23 (the developing unit of the present invention). Unit), a primary transfer roller 24, a static eliminator 25 (an example of the static eliminator of the present invention), and a drum cleaning device 26.

  As shown in FIG. 2, the organic photoconductor drum 21 has a conductive element tube 211 such as an aluminum tube, and an organic photosensitive layer 212 formed on the surface of the conductive element tube 211. The organic photosensitive layer 212 may be either a positively charged organic photosensitive layer or a negatively charged organic photosensitive layer, but a positively charged organic photosensitive layer is preferable. When the organic photosensitive layer 212 is a positively charged organic photosensitive layer, it may have a single layer structure containing a charge generating material and a charge transporting material. Known materials can be used as the charge generation material and the charge transport material.

  The scorotron 22 charges the surface of the organic photosensitive drum 21. The scorotron 22 has a discharge wire 221, a shield case 222, and a grid electrode 223. The discharge wire 221 performs corona discharge. The shield case 222 surrounds the discharge wire 221, and has an opening in a portion facing the organic photosensitive drum 21. The grid electrode 223 is provided in the opening of the shield case 222.

  The developing device 23 develops the electrostatic latent image formed on the surface of the organic photoconductor drum 21 by the exposure device 32 with a developer. The developer may be either a one-component developer containing no carrier or a two-component developer containing a carrier, but a two-component developer is preferred. The two-component developer preferably contains a magnetic toner.

  The static eliminator 25 removes electric charges on the surface of the organic photoconductor drum 21 by irradiating the surface of the organic photoconductor drum 21 with static elimination light to lower the potential of the organic photoconductor drum 21. As shown in FIG. 3, the static eliminator 25 has a light source 251 and a light quantity adjusting unit 252. The light source 251 emits the light with which the organic photosensitive drum 21 is irradiated. The light source 251 is, for example, an LED or a cold cathode tube. The light amount adjusting unit 252 adjusts the amount of light emitted from the light source 251, and adjusts the amount of static elimination light emitted from the static eliminator 25. As the light quantity adjusting unit 252, a known dimming circuit having, for example, a variable resistor, a transistor, or the like can be applied. Further, in the present embodiment, the static eliminator 25 irradiates the area on the surface of the organic photosensitive drum 21 between the transfer position by the primary transfer roller 24 and the cleaning position by the drum cleaning device 26 with the static eliminator light. That is, the static eliminator 25 performs so-called post-transfer static elimination.

  The intermediate transfer belt 31 shown in FIG. 1 carries a toner image composed of a plurality of color toner images (four colors in this embodiment). The intermediate transfer belt 31 is rotatably supported by a driving roller 311 and a driven roller 312. The surface of the intermediate transfer belt 31 can move while being in contact with the surface of each organic photosensitive drum 21.

  The exposure device 32 forms an electrostatic latent image on the surface of the organic photoconductor drum 21 by irradiating the surface of the organic photoconductor drum 21 uniformly charged by the scorotron 22 with light according to image data. This electrostatic latent image is developed by the developing device 23 and is visualized as a toner image.

  The secondary transfer roller 33 transfers the toner image transferred to the intermediate transfer belt 31 to the sheet conveyed from the paper feed tray 14. The sheet onto which the toner image has been transferred is conveyed to the fixing device 34 by a conveying unit (not shown). The fixing device 34 has a heating roller 341 and a pressure roller 342. The fixing device 34 conveys the sheet onto which the toner image is transferred while applying heat and pressure. As a result, the toner image is melted and fixed on the sheet. The sheet on which the toner image is fixed is further transported to the downstream side, and is discharged to the paper discharge tray 15 arranged above the intermediate transfer belt 31.

  The control unit 5 controls the image forming unit 13 as a whole. Further, the control unit 5 executes a pre-electrification process (see step S4 in FIG. 7), an image forming process (see steps S5 to S12 in FIG. 7), and the like. The control unit 5 is a computer having control devices such as a CPU, a ROM, and a RAM. The control unit 5 controls the image forming unit 13 and the like by using a RAM or the like as a temporary storage memory (working area) and executing a control program previously stored in the ROM. Further, as shown in FIG. 3, the control unit 5 includes a first acquisition processing unit 51, a first storage unit 52, a second acquisition processing unit 53, a second storage unit 54 (an example of a storage unit of the present invention), The light amount calculation processing unit 55 and the static elimination control unit 56 are provided.

  The first acquisition processing unit 51 acquires the charging time during which the surface of the organic photosensitive drum 21 is charged by the scorotron 22 in the image forming processing on the sheet in response to the image forming request. For example, the first acquisition processing unit 51 counts in synchronization with the clock signal while the voltage is being applied to the discharge wire 221 and the grid electrode 223, and acquires the charging time based on the count value. The first acquisition processing unit 51 may also acquire the charging time based on a real-time clock (RTC). Further, the first acquisition processing unit 51 acquires the charging time as the number of sheets (printed sheets) on which an image is formed in the image forming process, the number of times the organic photosensitive drum is rotated in the image forming process, or the like. You may.

  The first storage unit 52 stores the charging time acquired by the first acquisition processing unit 51. For example, the first storage unit 52 is realized by a RAM.

  The second acquisition processing unit 53 acquires a pause time during which the image forming process is paused. For example, the second acquisition processing unit 53 starts counting in synchronization with the clock signal when the image forming process is completed. In the present embodiment, when the image forming process is completed, the second acquisition processing unit 53 acquires the period until the next image forming request as the pause time. That is, the second acquisition processing unit 53 acquires the period until the next image forming request is made as the pause time each time the image forming process is completed. In this case, the second acquisition processing unit 53 ends the counting started when the image forming process ends when an image forming request is made. It should be noted that the second acquisition processing unit 53 acquires the pause time when the image forming processes are continuously performed for a plurality of jobs and when all the image forming processes for the plurality of jobs are completed. Good. Further, the second acquisition processing unit 53 may acquire the pause time based on a real time clock (RTC).

  The second storage unit 54 stores a table or an arithmetic expression that defines the relationship between the charging time, the rest time, and the light amount of the static elimination light emitted from the static elimination device 25 (the static elimination light amount). In the present embodiment, the second storage unit 54 stores the static elimination light amount table 541. Details of the static elimination light amount table 541 will be described later.

  The light amount calculation processing unit 55, based on the charging time acquired by the first acquisition processing unit 51 and the rest time acquired by the second acquisition processing unit 53, when the image formation request is made, Calculate the amount of static elimination light. Further, the light amount calculation processing unit 55 calculates the light amount of the static elimination light based on the table or the calculation formula stored in the second storage unit 54. Specifically, the light amount calculation processing unit 55 stores the number of prints as the charging time read from the first storage unit 52, the pause time acquired by the second acquisition processing unit 53, and the second storage unit 54. The charge removal light amount is calculated based on the stored charge removal light amount table 541.

  The static elimination control unit 56 controls the drive of the static elimination device 25 in order to cause the static elimination device 25 to emit the static elimination light having the light amount calculated by the light intensity calculation processing unit 55. In the present embodiment, the static elimination control unit 56 performs the preliminary static elimination process (see step S4 of FIG. 7) before the image formation process (see steps S5 to S12 of FIG. 7) and the static elimination process in the image formation process. (See step S9 in FIG. 7) The drive of the static eliminator 25 is controlled, and the static eliminator 25 emits the static eliminator having the light quantity calculated by the light quantity calculation processing unit 55.

  Here, FIG. 4 shows an example of the static elimination light amount table 541. The charge removal light amount table 541 shown in FIG. 4 defines the relationship among the number of printed sheets, which is an example of the charging time, the pause time, and the charge removal light amount. It should be noted that “T” in the charge removal light amount table 541 indicates a half exposure amount that is an exposure amount required to reduce the surface potential of the organic photoconductor drum 21 charged by the scorotron 22 to half. That is, the static elimination light amount table 541 shows the static elimination light amount as a ratio to the half-exposure amount T.

  In the static elimination light amount table 541, as the number of printed sheets in the image forming process increases (the charging time increases), the static elimination light amount tends to increase with an upper limit of 10 times (10T) of the half exposure amount T. This is because the longer the charging time is, the more the amount of the discharge products deposited on the surface of the organic photoconductor drum 21 tends to be. Therefore, the longer the charging time is, the larger the amount of static elimination light needs to be. Further, in the static elimination light amount table 541, the longer the pause time, the smaller the static elimination light amount tends to be, with the lower limit being three times (3T) of the half exposure amount T. This is because the discharge products attached to the surface of the organic photoconductor drum 21 decrease with time. It should be noted that three times (3T) of the half-dose exposure amount T is a general charge removal light amount when the influence of the discharge products is not taken into consideration.

  In the example shown in FIG. 4, the charge removal light amount is in the range of 3 times (3T) or more and 10 times (10T) or less of the half-exposure amount T according to the amount of the discharge products attached on the surface of the organic photosensitive drum 21. It is set. Specifically, the charge removal light amount lowers a potential corresponding to, for example, a difference ΔV between the surface potential Va of the organic photosensitive drum 21 after the charging process and the minimum surface potential Vb of the organic photosensitive drum 21 at the time of transfer. It is defined as the amount of light required for (see FIG. 5). The surface potential Va is, for example, an average value of the surface potential of the organic photosensitive drum 21 after charging and before transfer. The surface potential Va may be the maximum surface potential or the minimum surface potential of the organic photosensitive drum 21 after charging and before transfer. Further, the surface potential Va, the minimum surface potential Vb, and the difference ΔV are values that are predetermined by experiments. That is, the static elimination light amount shown in the static elimination light amount table 541 is a value predetermined by an experiment.

  As described above, the light amount calculation processing unit 55 calculates the charge removal light amount based on the charge removal light amount table 541. That is, the light amount calculation processing unit 55 determines the charge removal light amount from the range of 3 times (3T) or more and 10 times (10T) or less of the half exposure amount T.

  Specifically, the light amount calculation processing section 55 applies the transfer voltage to the organic photoconductor drum 21 when the discharge product does not adhere to the organic photoconductor drum 21 or when the discharge product hardly adheres to the organic photoconductor drum 21. If the surface potential of the organic photoconductor drum 21 does not drop even by the above, the amount of static elimination light is determined to be 3 times the half-exposure amount T (3T). That is, when it is estimated that the cleanliness of the surface of the organic photoconductor drum 21 can be ensured, the light amount calculation processing unit 55 determines the charge removal light amount to be three times the half exposure amount T (3T). For example, when the number of printed sheets is four or less, or when the pause time is more than 200 hours, the light amount calculation processing unit 55 determines the charge removal light amount to be three times the half exposure amount T (3T).

  On the other hand, in the case where the light quantity calculation processing unit 55 causes the discharge products to adhere to the organic photoconductor drum 21, the surface potential of the organic photoconductor drum 21 significantly drops even when the transfer voltage is applied to the organic photoconductor drum 21. In this case, the amount of the static elimination light is determined to be 10 times (10T) the half exposure amount T. That is, when it is estimated that the maximum amount of the discharge product assumed in advance is attached to the surface of the organic photoconductor drum 21, the light amount calculation processing unit 55 sets the charge removal light amount to 10 times the half exposure amount T. Determine to (10T). For example, when the number of printed sheets is 150 or more and the pause time is 10 hours or less, the light amount calculation processing unit 55 determines the charge removal light amount to be 10 times (10T) the half exposure amount T.

  Here, FIG. 5 shows an example of changes over time in the surface potential of the organic photoconductor drum 21 after charging the organic photoconductor drum 21 to which the discharge products are attached, before transfer, during transfer, and after transfer. The surface potential was measured using a surface potential meter (not shown) whose position was fixed while the organic photosensitive drum 21 was rotated. As the organic photoconductor drum 21, one having a positively charged organic photoconductive layer was used, and was charged to a positive polarity by a scorotron 22. The transfer of the organic photosensitive drum 21 was performed by applying a negative transfer voltage using the primary transfer roller 24.

  As shown in FIG. 5, in the organic photoconductor drum 21 to which the discharge products are attached, the surface potential periodically drops. This periodic decrease in the surface potential corresponds to the portion of the organic photoconductor drum 21 where the discharge product is attached. When the organic photoconductor drum 21 is transferred, the amount of periodic decrease in the surface potential is significantly larger than before and after the transfer. It is considered that this is because the discharge product is ionized by the negative transfer voltage and the negative charge at the time of transfer is injected into the organic photosensitive layer 212 of the organic photosensitive drum 21.

  Generally, a decrease in surface potential at the time of transfer causes deterioration in image quality due to image deletion, white stripes, and the like. Therefore, in order to prevent the occurrence of image deletion due to the discharge products, an image forming apparatus has been proposed that forms an electrostatic latent image on the photoconductor drum while avoiding a defective area on the photoconductor drum to which the discharge product may be attached. ing. However, when an electrostatic latent image is formed on the photoconductor drum while avoiding the defective area, the defective area is specified, and then the timing at which the defective area passes through the exposure device is specified to expose the defective area. Need to stop. Further, when the exposure in the defective area is stopped, a void area in which a toner image is not formed is formed corresponding to the defective area. Therefore, when the toner image is transferred to the sheet, it is necessary to specify the timing at which the missing area faces the sheet and stop the movement of the sheet at that timing. As described above, in the method of forming the electrostatic latent image on the photosensitive drum while avoiding the defective area, the control in the image forming process becomes complicated.

  On the other hand, in the image forming apparatus 10 according to the present exemplary embodiment, when the image forming request is made, the pre-electrification processing is executed before the image forming processing is executed. In this preliminary charge removal processing, the charge removal light of the light quantity calculated by the light quantity calculation processing unit 55 is emitted from the charge removal device 25 toward the organic photoconductor drum 21 under the control of the charge removal control unit 56. The surface of the organic photoconductor drum 21 is irradiated with the static elimination light emitted from the static eliminator 25. By continuing the irradiation state of the charge removal light to the organic photoconductor drum 21 while rotating the organic photoconductor drum 21, the charge removal light is applied to the entire surface of the organic photoconductor drum 21. On the organic photosensitive layer 212 of the organic photosensitive drum 21, trap carriers are generated by being irradiated with the static elimination light. As a result, the surface potential of the entire organic photoconductor drum 21 is lowered. Specifically, in the organic photoconductor drum 21, for example, the surface potential other than the portion to which the discharge product is attached is approximately the same as the surface potential (minimum surface potential Vb (see FIG. 5)) of the portion to which the discharge product is attached. Be lowered to. As a result, it is possible to prevent the occurrence of unevenness of the surface potential on the organic photoconductor drum 21 before charging (“before charging process” in FIG. 6). If the generation of the unevenness of the surface potential on the organic photosensitive drum 21 before the charging can be prevented in this manner, the occurrence of the unevenness of the surface potential on the organic photosensitive drum 21 after the charging can be prevented (see “Charging Process in FIG. 6”). rear"). As a result, it is possible to prevent the surface potential of the organic photosensitive drum 21 from remarkably decreasing locally due to the application of the transfer voltage, and it is possible to suppress the deterioration of the image quality due to the discharge products.

  Further, as described above, the amount of static elimination light shown in the static elimination light amount table 541 is, for example, the difference ΔV between the surface potential Va of the organic photosensitive drum 21 after the charging process and the minimum surface potential Vb of the organic photosensitive drum 21 at the time of transfer. Is defined as the amount of light required to drop the potential corresponding to. In this case, since the amount of static elimination light is determined according to the state of attachment of the discharge products on the organic photoconductor drum 21, pre-static elimination is performed according to the amount of decrease in the surface potential at the time of transfer due to the discharge products on the organic photoconductor drum 21. The surface potential of the processed organic photosensitive drum 21 is determined. Therefore, it is possible to prevent the surface potential of the organic photoconductor drum 21 before charging from being excessively lowered.

  Further, in the image forming apparatus 10, even in the static elimination process in the image forming process, the static elimination of the organic photosensitive drum 21 is performed under the same conditions as the preliminary static elimination process. Therefore, when the image data related to the print request is to form an image on two or more sheets, it is possible to suppress the deterioration of the image quality due to the discharge products even in the image forming processing for the second and subsequent sheets.

  As described above, in the image forming apparatus 10, the light amount of the static elimination light emitted from the static elimination device 25 is adjusted based on the relationship between the charging time determined by the static elimination light amount table 541 and the like, the idle time, and the static elimination light amount. Only by doing so, it is possible to prevent the surface potential of the organic photoconductor drum 21 from being remarkably lowered locally by applying the transfer voltage. Therefore, in the image forming apparatus 10, the deterioration of the image quality due to the discharge products can be suppressed by the simple control.

  Next, with reference to the flowchart of FIG. 7, the image formation request time process executed by the control unit 5 will be described. This image formation request time process is a process executed after an image formation request is made. In the flowchart shown in FIG. 7, the charge removal light amount is calculated based on the number of printed sheets as the charging time. In the figure, S1, S2, ... Represent step numbers of the processing procedure. In the image forming request processing, steps S5 to S12 are the image forming processing.

<Step S1>
As shown in FIG. 7, in step S1, the control unit 5 acquires the time from the time when the second acquisition processing unit 53 starts the time measurement to the time when there is an image formation request in step S13, which will be described later, as a pause time. To do. The control unit 5 clears the clock time when the pause time is acquired.

<Step S2>
In step S2, the light amount calculation processing unit 55 of the control unit 5 reads out the number of printed sheets stored in the first storage unit 52, which is incremented by the first acquisition processing unit 51 in step S11 described below. On the other hand, when the number of printed sheets is read by the light amount calculation processing unit 55, the first acquisition processing unit 51 clears the count value of the number of printed sheets.

<Step S3>
In step S3, the light amount calculation processing unit 55 of the control unit 5 calculates the light amount of the static elimination light emitted from the static elimination device 25 in accordance with the static elimination light amount table 541 based on the pause time obtained in step S1 and the number of printed sheets obtained in step S2. .

<Step S4>
In step S4, the static elimination control unit 56 of the control unit 5 executes a preliminary static elimination process. The pre-static charge removal process is a process executed before the image forming process (steps S5 to S12). Specifically, the static elimination control unit 56 controls the light amount adjustment unit 252 of the static elimination device 25 based on the light amount of the static elimination light calculated in step S3, and at least while the organic photosensitive drum 21 makes one rotation, the light source 251. To emit light from.

<Step S5>
In step S5, the control unit 5 drives the scorotron 22 and executes a charging process for uniformly charging the surface of the organic photosensitive drum 21.

<Step S6>
In step S6, the control unit 5 drives the exposure device 32 based on the image data to execute an exposure process for forming an electrostatic latent image on the surface of the organic photoconductor drum 21.

<Step S7>
In step S7, the control section 5 drives the developing device 23 to execute a developing process for visualizing the electrostatic latent image with a developer.

<Step S8>
In step S8, the controller 5 executes a transfer process. The transfer process in step S8 is performed by applying a transfer voltage to the primary transfer roller 24 to transfer the toner image carried on the organic photoconductor drum 21 to the intermediate transfer belt 31, and a transfer voltage to the secondary transfer roller 33. Is applied to transfer the toner image carried on the intermediate transfer belt 31 to the sheet.

<Step S9>
In step S9, the static elimination control unit 56 of the control unit 5 controls the static elimination device 25 to execute the static elimination process for removing the toner remaining on the organic photosensitive drum 21. The static elimination control unit 56 controls the light amount adjustment unit 252 of the static elimination device 25 based on the light amount of the static elimination light calculated in step S3, as in the above-described preliminary static elimination process of step S4. The light source 251 emits light during one rotation.

<Step S10>
In step S10, the control unit 5 drives the fixing device 34 to execute a fixing process of fixing the toner image transferred to the sheet.

<Step S11>
In step S11, the first acquisition processing unit 51 of the control unit 5 increments the count value of the number of printed sheets stored in the first storage unit 52.

<Step S12>
In step S12, the control unit 5 determines whether there is unprocessed image data. When there is unprocessed image data (step S12: Yes), the controller 5 shifts the process to step S5 and continues the image forming process. On the other hand, when there is no unprocessed image data (step S12: No), the control unit 5 ends the image forming process and shifts the process to step S13.

<Step S13>
In step S13, the control unit 5 starts counting the pause time and ends the image formation request time process.

10 Image Forming Device 21 Organic Photosensitive Drum 212 Organic Photosensitive Layer 22 Scorotron 23 Developing Device 25 Static Eliminating Device 32 Exposure Device 5 Control Unit 51 First Acquisition Processing Unit 53 Second Acquisition Processing Unit 54 Second Storage Unit 541 Static Emission Light Quantity Table 55 Light Intensity Arithmetic processing unit 56 Static elimination control unit

Claims (9)

An organic photosensitive drum that is rotatably supported and carries toner;
A charging unit for charging the surface of the organic photosensitive drum by using corona discharge,
A charge removing unit that removes electric charges on the surface of the organic photoconductor drum by irradiating the surface of the organic photoconductor drum with charge removing light, and reduces the potential.
A first acquisition processing unit that acquires a charging time during which the surface of the organic photosensitive drum is charged by the charging unit in the image forming process on the sheet;
A second acquisition processing unit that acquires a pause time during which the image forming process is paused;
When there is an image formation request, the charge removal time to be emitted from the charge removal unit based on the charging time acquired by the first acquisition processing unit and the rest time acquired by the second acquisition processing unit. A light amount calculation processing unit for calculating the light amount of lightning,
E Bei and a neutralization controller for controlling the driving of the discharger in order to emit the lamp light of the computed the amount from the discharger by the light amount calculating section,
The static elimination control unit controls the drive of the static elimination unit in the static elimination process for removing the toner remaining on the organic photosensitive drum, which is executed in the image forming process, and is calculated by the light amount calculation processing unit. An image forming apparatus that causes the static elimination light of the light amount to be emitted from the static elimination unit .   The image forming apparatus according to claim 1, wherein the light amount calculation processing unit determines the light amount of the static elimination light emitted from the static elimination unit from a range of 3 times to 10 times the half-exposure amount. The charging time, the rest time, and further has a storage unit that stores a table or an arithmetic expression that defines a relationship between the light amount of the static elimination light emitted from the static elimination unit,
The image forming apparatus according to claim 1, wherein the light amount calculation processing unit calculates the light amount of the static elimination light based on the table or the arithmetic expression stored in the storage unit.   The static elimination control unit controls driving of the static elimination unit before executing the image forming processing in response to the image formation request, and removes the static elimination light of the light amount calculated by the light amount calculation processing unit. The image forming apparatus according to claim 1, wherein the image forming apparatus emits light from the image forming apparatus. The dwell time, image forming apparatus according to any one of claims 1 to 4 from the end of the image forming process is a period until the next image forming request. The organic photosensitive drum, an image forming apparatus according to claims 1 having a positively charged organic photosensitive layer to claim 5. The image forming apparatus according to claim 6 , wherein the positively charged organic photosensitive layer has a single layer structure containing a charge generating material and a charge transporting material. The charging unit, an image forming apparatus according to any one of claims 1 to 7 is scorotron. An exposure unit that forms an electrostatic latent image on the surface of the organic photoconductor drum by irradiating the organic photoconductor drum whose surface is charged by the charging unit with light.
The image forming apparatus according to claim 8 and a developing unit for developing the electrostatic latent image by a developer containing a magnetic toner and carrier, from claim 1, further comprising a.

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