JP2010097039A - Developer supplying device, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration in image quality due to creep formed on a developing roller without using a special constitution or a member. <P>SOLUTION: A developer supplying device supplies developer to a developing roller 342 for supplying the developer to a photoreceptor drum 31 in a multifunction machine 1, and includes a supplying roller 343, a creep information detection section 185 and a developer supplied amount adjusting section 183. The supplying roller 343 is a member which can supply the developer to the developing roller 342. The creep information detection section 185 is a means for detecting the creep information regarding the creep in the developing roller 342. The developer supplied amount adjusting section 183 is a means for adjusting the supplied amount of the developer to the developer roller 342 from the supplying roller 343 based on the creep information detected by the creep information detection section 185. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developer supply device, a process cartridge, and an image forming apparatus, and in particular, a developer supply device that supplies developer to a developing roller that supplies developer to an electrostatic latent image carrier of the image forming apparatus, and developer supply The present invention relates to a process cartridge including the apparatus and an image forming apparatus including the process cartridge.

  Generally, an electrophotographic image forming apparatus includes an image forming unit having a photosensitive drum, a charging device, a cleaning device, and a developing device, a fixing unit, a paper transport unit, and a discharge unit. is there.

  In this image forming apparatus, the surface of the photosensitive drum is charged by the charging device. Then, the photosensitive drum is irradiated with laser light, and an electrostatic latent image based on image information is formed on the photosensitive drum. Thereafter, a developer is supplied from the developing device to the electrostatic latent image. The image formed on the photosensitive drum is transferred to the sheet conveyed by the sheet conveying unit, and the image is fixed on the sheet by the fixing unit. After the image on the photosensitive drum is transferred to the paper, the developer remaining on the photosensitive drum without being transferred is cleaned by a cleaning device. Thereafter, the paper on which the image is printed is discharged from the discharge unit to the outside of the apparatus.

  Here, the developing device includes a developer container that can store the developer therein, a developing roller that supplies the developer inside the developer container to the photosensitive drum, and the thickness of the developer layer of the developer roller. Some have a regulating blade for regulating the above and a supply member capable of supplying the developer to the developing roller. In this developing device, the developer inside the developing device is supplied to the developing roller by the supply member, and the thickness of the developer layer on the developing roller is regulated by the regulating blade. Thereafter, the developer is supplied from the developing roller to the photosensitive drum.

  If the developing roller is in contact with another member such as a regulating blade or a photosensitive drum for a long time, creep may be formed on the surface of the developing roller. Here, creep refers to elastic deformation that requires a long time to release the deformation. For example, when another roll or plate is kept in contact with a roll formed of a material such as rubber or urethane for a long time, a creep is formed. When the developer is supplied to the developing roller in a state where creep is formed on the developing roller, the developer in the creep portion of the developing roller is less than the developer in other portions of the developing roller. For this reason, the amount of developer supplied to the photosensitive drum is reduced only by the creep portion, which may reduce the quality of the formed image.

In order to solve such a problem, a process cartridge provided with a cushioning sheet member has been considered. In this process cartridge, the buffering sheet member is disposed so that the buffering sheet member is positioned between the photosensitive drum and the regulating blade and the developing roller. (See Patent Document 1)
JP 2005-316507 A

  In the apparatus described in Patent Document 1, it is necessary to dispose a buffer sheet member around the developing roller. However, there is little space around the developing roller, and it is difficult to dispose the buffer sheet member. Further, the buffer sheet member is sandwiched between the developing roller, the photosensitive drum, the regulating member, and the like, and it is difficult to remove the buffer sheet member.

  An object of the present invention is to prevent image quality from being deteriorated by creep formed on a developing roller without using a special configuration or member.

  A developer supply device according to a first aspect of the present invention is a device that supplies a developer to a developing roller that supplies a developer to an electrostatic latent image carrier of an image forming apparatus, and includes a supply member, a creep information detection unit, and a supply And an amount adjusting means. The supply member is a member capable of supplying the developer to the developing roller. The creep information detecting means is means for detecting creep information related to creep of the developing roller. The supply amount adjusting means is means for adjusting the supply amount of the developer to the developing roller of the supply member based on the creep information detected by the creep information detecting means.

  The developer supply amount adjusting device detects creep information related to creep of the developing roller. The developer supply amount to the developing roller of the supply member is adjusted based on the creep information, and the developer is supplied from the supply member to the developing roller.

  Here, since the creep information is detected and the developer supply amount is adjusted based on the creep information, it is possible to prevent the image quality from being deteriorated due to the decrease in the developer supply due to the creep. Here, for example, the developer supply amount is increased in accordance with the creep of the developing roller, so that the amount of developer adhering to the creep portion can be increased, and the image quality is prevented from being deteriorated due to the effect of creep. it can. The creep information is information including the presence / absence of creep on the developing roller, the depth and width of the creep, and the like. Creep is an effect that affects the image quality in the image forming operation, and at least the cause of creep, for example, the electrostatic latent image from the developing roller from the point when the regulating member does not contact the developing roller. This refers to elastic deformation that cannot be recovered until the developer is supplied to the carrier.

  A developer supply apparatus according to a second aspect is the developer supply apparatus according to the first aspect, wherein an AC bias is applied to the developing roller and the supply member during an image forming operation. The supply amount adjusting means adjusts the developer supply amount of the supply member to the developing roller by adjusting at least one of an alternating current bias applied to the developing roller and an alternating current bias applied to the supply member.

  Here, since the developer supply amount can be adjusted by adjusting the AC bias applied to the supply member and the developing roller, it is not necessary to provide a mechanism for adjusting the developer supply amount. For this reason, it is possible to prevent an increase in cost due to the installation of a mechanism for adjusting the developer supply amount. And the enlargement of the apparatus by installing the mechanism which adjusts a developer supply amount can be prevented.

  A developer supply apparatus according to a third aspect is the developer supply apparatus according to the second aspect, wherein the supply amount adjusting means has a difference between an AC bias applied to the developing roller and an AC bias applied to the supply member. Increase the time that is occurring.

  Here, the amount of developer supplied to the developing roller can be increased by increasing the time during which the developer is supplied from the supply member to the developing roller. Further, the developer supply amount can be increased without providing a special mechanism.

  A developer supply device according to a fourth aspect is the developer supply device according to the third aspect, wherein the supply amount adjusting means has a difference between an AC bias applied to the developing roller and an AC bias applied to the supply member. The values of the AC bias applied to the developing roller and the AC bias applied to the supply member are adjusted according to the time that has occurred.

  Here, by adjusting the AC bias applied to the developing roller and the supply roller, the amount supplied from the developing roller to the electrostatic latent image carrier during the image forming operation can be prevented from increasing.

  A developer supply apparatus according to a fifth aspect of the present invention is the developer supply apparatus according to any one of the first to fourth aspects, wherein the developing roller is in contact with a regulating member capable of regulating the thickness of the developer layer. The creep information detecting means detects a creep amount on the surface of the developing roller.

  Here, since the regulating member is in contact with the developing roller, creep is easily formed on the developing roller, and the present invention is effective.

  A developer supply device according to a sixth aspect of the present invention is the developer supply device according to the fifth aspect, wherein the date when the regulating member is disposed so as to contact the development roller and the date when the development roller is used can be stored. Storage means is further provided. The creep information detecting means detects creep information based on the time when the restricting member is disposed so as to contact the developing roller and the date and time when the developing roller is used.

  Here, the time required for the developing roller to recover to its original shape is determined by the time during which the developing roller is pressed by another member. Here, the time includes seconds, minutes, hours, days, months, and years.

  Here, the creep information is estimated from the driving stop time of the developing roller, and the developer supply amount is adjusted. Therefore, it is not necessary to directly measure the creep formed on the developing roller. For this reason, it is not necessary to provide a structure for creep measurement.

  A developer supply device according to a seventh aspect of the present invention is the developer supply device according to any one of the first to sixth aspects, further comprising a humidity detection means for detecting the humidity around the developing roller. The developer supply amount adjusting means adjusts the developer supply amount to the developing roller of the supply member according to the humidity detected by the humidity detecting means.

  Here, the time for recovery from the state of creep and deformation also changes depending on the humidity.

  Here, an appropriate amount of developer can be supplied to the developing roller by detecting the humidity and estimating the creep amount according to the detected humidity.

  A process cartridge according to an eighth aspect of the invention includes an electrostatic latent image carrier capable of carrying an electrostatic latent image on a surface thereof, a developing roller capable of supplying a developer to the electrostatic latent image carrier, and a developer supplied to the developing roller. The developer supply device according to claim 1 is provided.

  An image forming apparatus according to a ninth aspect includes the process cartridge according to the eighth aspect.

  In the present invention, it is possible to prevent the image quality from being deteriorated by creep formed on the developing roller without using a special configuration or member.

[First Embodiment]
[overall structure]
Hereinafter, a multifunction machine 1 as an image forming apparatus according to the present invention will be described with reference to FIG. Here, FIG. 1 shows an overall outline of the multifunction machine 1 according to the present invention. The multifunction device 1 is connected to an external computer or the like, and can form an image on a sheet based on image information read from a document or image information sent from a computer.

  The multifunction device 1 has various functions such as a function of copying a document and a function of transmitting image information of the document. As shown in FIG. 1, the multifunction device 1 includes a document reading unit 2, an image forming unit 3, a transfer unit 4, a sheet storage unit 5, a sheet transport unit 6, a fixing unit 7, and a discharge unit 8. And an application control device 9 (see FIG. 7). The configuration of each functional unit will be described below.

{Original reading unit}
The document reading unit 2 is a part for reading image information of a document. The document reading unit 2 is disposed at the top of the multifunction device 1.

{Image forming part}
The image forming unit 3 is a part for forming an image on a sheet based on image information. The image forming unit 3 is disposed between the paper storage unit 5 and the document reading unit 2. Further, the image forming unit 3 includes four image forming units 30. The four image forming units 30 are arranged in a line. The four image forming units 30 include a photosensitive drum 31 (electrostatic latent image carrier), a charging device 32, a laser unit 33, a developing device 34, a toner storage unit 35, and a charge eliminating device 36, respectively. , A drum cleaning device 37, a first AC bias applying device 38 shown in FIG. 2, and a second AC bias applying device 39 shown in FIG. The four image forming units 30 can form yellow, magenta, cyan, and black toner images in order from the left side of FIG. The image forming units 30 have the same configuration. The yellow image forming unit 30 will be described below.

  The photosensitive drum 31 is a member capable of carrying an electrostatic latent image on the surface. Further, the photosensitive drum 31 is rotatable around a rotation axis extending perpendicularly to the paper surface of FIG. The photosensitive drum 31 is disposed so as to contact a transfer belt 41 described later.

  The charging device 32 is a device for uniformly charging the surface of the photosensitive drum 31. The charging device 32 is disposed below the photosensitive drum 31.

  The laser unit 33 is a device for irradiating the surface of the photosensitive drum 31 with laser light based on image information. The laser unit 33 is disposed below the photosensitive drum 31.

  FIG. 2 shows a partially enlarged view around the developing device 34. The developing device 34 will be described with reference to FIG. The developing device 34 is a device capable of supplying a developer to the electrostatic latent image carried on the photosensitive drum 31. Further, each developing device 34 is arranged on the upper side of each laser unit 33. Further, the developing device 34 includes a developing container 341, a developing roller 342, a supply roller 343 (supply member), a regulating blade 344 (regulating member), a stirring screw 345, and a creep information detecting device 346 (see FIG. 7) ( Creep information detecting means).

  The developing container 341 is a container that can store a developer of a color corresponding to each photosensitive drum 31 therein.

  The developing roller 342 is a member for supplying a developer to the photosensitive drum 31. The developing roller 342 is supported by the developing container 341. Further, the developing roller 342 is disposed so as to face the photosensitive drum 31. The developing roller 342 has a layer formed of an elastic member such as rubber or urethane near the surface. For this reason, when the developing roller 342 is in contact with another member for a long time, creep is formed.

  The supply roller 343 is a member for supplying the developer inside the developing container 341 to the developing roller 342. Further, the supply roller 343 is rotatably supported by the developing container 341. Further, the supply roller 343 is disposed in parallel with the developing roller 342.

  The regulating blade 344 is a member for regulating the thickness of the developer layer of the developing roller 342. Further, the regulating blade 344 is disposed so as to contact the surface of the developing roller 342. Further, the regulation blade 344 is a plate-like member. The regulating blade 344 is a member that extends along the developing roller 342. As shown in FIG. 2, a bias applying device 344 a is connected to the regulating blade 344 so that an AC bias is applied to the regulating blade 344.

  The stirring screw 345 is a member for stirring the developer inside the developing container 341. Two stirring screws are accommodated in the developing container 341. Further, the stirring screw 345 is disposed in parallel with the developing roller 342 and the supply roller 343.

  The creep information detecting device 346 (see FIG. 7) is a device for detecting information on creep formed on the developing roller 342. The creep information detecting device 346 has a laser displacement meter 346a (see FIG. 2) disposed in the vicinity of the developing roller 342. The laser displacement meter 346a is a reflection type device. The laser displacement meter 346a measures the displacement from the reflected light of the laser irradiated on the object. The creep information detection device 346 detects the presence or absence of creep or the displacement of creep from the measurement result of the laser displacement meter 346a.

  The toner storage portion 35 is a portion for storing toner that can be supplied to the developing device 34. The toner storage unit 35 includes a toner container 351 that can store toner corresponding to the color of each developing device 34. The toner container 351 is connected to the developing device 34 by a supply path (not shown).

  The static eliminator 36 is a device for removing charges on the surface of the photosensitive drum 31. The static eliminator 36 is disposed below the photosensitive drum 31.

  The drum cleaning device 37 is a device for cleaning the developer remaining on the photosensitive drum 31 without being used for the developing operation. The drum cleaning device 37 includes a blade member 371 that contacts the surface of the photosensitive drum 31, and a waste developer storage container 372 that can store toner scraped off by the blade member 371.

  The first AC bias applying device 38 is a device for applying an AC bias to the developing roller 342. The first AC bias applying device 38 is connected to the developing roller 342. Specifically, the first AC bias applying device 38 applies an AC bias A having a shape as shown in FIG. 3 to the developing roller 342 during the image forming operation.

  The second AC bias applying device 39 is a device for applying an AC bias to the supply roller 343. The second AC bias applying device 39 is a device for applying an AC bias to the supply roller 343. Specifically, the second AC bias applying device 39 applies an AC bias B having a shape as shown in FIG. 4 to the supply roller 343 during the image forming operation.

  Here, the supply is performed according to the magnitude of the effective bias E indicated by the product of the difference C between the AC bias applied to the developing roller 342 and the AC bias applied to the supply roller 343 and the time D during which the difference occurs. The amount of developer supplied from the roller 343 to the developing roller 342 changes. FIG. 5 shows the effective bias E during the image forming operation. The portion E in FIG. 5 indicates the effective bias.

  A process cartridge 30a including the photosensitive drum 31, the developing device 34, and the application control device 9 is configured (see FIG. 7). Therefore, the photosensitive drum 31, the developing device 34, and the application control device 9 can be handled as a unit. The process cartridge 30 a is provided with a date and time storage unit 30 b that stores the date and time when the developing roller 342 is disposed so as to contact the regulating blade 344 and the date and time when the developing roller 342 is used.

{Transcription part}
The transfer unit 4 includes a transfer belt 41, four primary transfer rollers 42, a secondary transfer roller 43, and a belt cleaning device 44.

  The transfer belt 41 is a member for transferring an image formed by the image forming unit 3 to a sheet. The transfer belt 41 is a member to which an image is primarily transferred from the photosensitive drum 31. Further, the transfer belt 41 is disposed on the upper side of the photosensitive drum 31.

  The primary transfer roller 42 is a member for transferring the image on the photosensitive drum 31 onto the transfer belt 41. The primary transfer roller 42 is disposed so as to face the photosensitive drum 31 with the transfer belt 41 interposed therebetween. Further, each primary transfer roller 42 is connected to a voltage application device (not shown). Each primary transfer roller 42 is arranged in parallel with the direction in which the photosensitive drums 31 are arranged.

  The secondary transfer roller 43 is a member for transferring the image primarily transferred from the photosensitive drum 31 to the transfer belt 41 onto a sheet. The secondary transfer roller 43 is disposed so as to face the transfer belt 41 with the paper transport path of the paper transport unit 6 interposed therebetween.

  The belt cleaning device 44 is a device for cleaning toner, paper dust, dust and the like on the transfer belt 41. The belt cleaning device 44 is disposed on the left side of the transfer belt member 41 in FIG.

{Paper storage}
The paper storage unit 5 is a part for storing paper. The paper storage unit 5 is disposed at the lower part of the multifunction machine 1. Further, the paper storage unit 5 has a plurality of paper feed cassettes 51. Each paper cassette 51 stores different types (sizes, etc.) of paper. A plurality of paper feed cassettes 51 are stacked.

{Paper transport section}
The paper transport unit 6 is a part for transporting paper to each functional unit. The paper transport unit 6 has a paper transport path for transporting paper in the order of the paper storage unit 5, the image forming unit 4, the fixing unit 7, and the discharge unit 8. The paper transport unit 6 includes a paper transport guide pair 61 and a plurality of paper transport roller pairs 62.

  The paper transport guide pair 61 is a member for guiding the paper transport direction. The paper transport guide pair 61 has plate-like members arranged so as to face each other. A sheet can pass between these plate-like members.

  The paper transport roller pair 62 is a member for transporting paper in the paper transport direction. The pair of paper transport rollers 62 has two rollers arranged to face each other. The sheet can pass between the two rollers.

{Fixing part}
The fixing unit 7 is a part for fixing an image on a sheet. The fixing unit 7 is disposed on the downstream side of the transfer unit 4 in the sheet conveyance direction. Further, the fixing unit 7 includes a heating roller 71 that heats the image on the paper, and a pressure roller 72 that is disposed to face the heating roller 71 and presses the paper between the heating roller 71. .

{Discharge unit}
The discharge unit 8 is a part for discharging the sheet to the outside of the multifunction device 1. As shown in FIG. 1, the discharge unit 8 is disposed downstream of the fixing unit 7 in the sheet conveyance direction. The discharge unit 8 has a discharge roller 81. The discharge unit 8 is disposed below the document reading unit 3. The discharge unit 8 further includes a recess 82 that is recessed rightward from the left side surface of the multifunction device 1 in FIG. Then, the sheet is discharged into the recess 82.

[Application control device]
The application control device 9 is a device for controlling the first AC bias application device 38 and the second AC bias application device 39. FIG. 7 shows a block diagram of the application control device 9. Hereinafter, the application control device 9 will be described with reference to the block diagram of FIG.

  The application control device 9 includes a storage unit 91 (storage means) and a CPU. The application control device 9 includes a developer supply amount adjustment unit 92 (supply amount adjustment unit) and a humidity detection unit 93 (humidity detection unit). The application control device 9 is a device that controls each functional unit by executing a program stored in the storage unit 91.

The storage unit 91 stores programs for causing various functional units to function. The storage unit 91 is a part that stores information on the relationship between the absolute humidity and the creep amount and the AC bias applied to the developing roller 342 and the supply roller 343. Specifically, the storage unit stores relationship information as shown in the table of FIG. The relationship information shown in FIG. 8 is, for example, when the absolute humidity is less than 4 g / m ³ and the creep amount is 4 μm to 10 μm, the duty ratio is increased by 5%. Further, an absolute humidity ^{4g / m 3 ~264g / m 3} , when the creep amount is 4μm~10μm indicates that increasing the Duty ratio of 10%. Here, the duty ratio means the ratio of the time during which the effective bias occupies one wavelength of the AC bias, that is, D / F in FIG. Note that during a normal image forming operation, the duty ratio is set to 30%.

  The developer supply amount adjusting unit 92 is a part that adjusts the developer supply amount. The developer supply amount adjusting unit adjusts the amount of developer supplied from the supply roller 343 to the development roller 342 by adjusting the AC bias applied to the development roller 342 and the supply roller 343. Specifically, the AC bias applied to the developing roller 342 and the supply roller 343 is determined from the relation information of FIG. 8 stored in the storage unit 91 based on the creep information detected by the creep information detection device 346, and determined. The developer supply amount adjusting unit controls the first AC bias application device 38 and the second AC bias application device 39 so that the applied AC bias is applied to the developing roller 342 and the supply roller 343, so that the developer supply amount adjustment unit Adjust. For example, the first AC bias applying device 38 and the second AC bias applying device 39 are controlled so that an effective bias as shown in FIG. 6 acts between the developing roller 342 and the supply roller 343.

  Here, the AC bias applied to the developing roller 342 and the supply roller 343 in the state of FIG. 6 has a maximum value and a minimum value of 200 V than the AC bias applied to the developing roller 342 and the supply roller 343 in the state of FIG. It is rising. This is because the amount of developer supplied from the developing roller 342 to the photosensitive drum 31 during the image forming operation is set to the same amount as in FIG. That is, the duty ratio in FIG. 6 is higher than that in FIG. 5, and the developer supplied from the developing roller 342 to the photosensitive drum 31 when the same developing bias (minimum value) as in FIG. 5 is applied. Will increase. Therefore, the maximum value and the minimum value of the AC bias applied to the developing roller 342 and the supply roller 343 are increased in the case of FIG. 6 than in the case of FIG. As described above, the maximum value and the minimum value of the AC bias applied to the developing roller 342 and the supply roller 343 are increased as the duty ratio increases.

  The humidity detector 93 is a part for detecting the humidity around the developing roller 342. The humidity detection unit 93 includes a thermometer 931 and a hygrometer 932 arranged around the developing roller 342. The humidity detector 93 detects absolute humidity from the hygrometer 932 and the thermometer 931.

  The supply roller 343 and the application control device 9 constitute a developer supply device 94 (see FIG. 7).

[Operation]
Next, the operation of the multifunction device 1 will be described.

  When image information of an original is read by the original reading unit 2 or image information is sent from a computer connected to the outside of the multifunction machine 1, an electrostatic latent image is formed on the photosensitive drum 31 based on the image information. . Specifically, the surface of the photosensitive drum 31 is charged by the charging device 32, and laser light is irradiated from the laser unit 33 to the photosensitive drum 31 based on the image information. When the electrostatic latent image is formed on the photosensitive drum 31 in this way, the developer is supplied from the developing roller 342 of the developing device 34 to the electrostatic latent image. When the developer is supplied from the developing device 34 to the electrostatic latent image, a toner image is formed on the photosensitive drum 31.

  Then, the toner image on each photosensitive drum 31 is transferred to the transfer belt 41. Then, the toner image on the transfer belt 41 is transferred to a sheet. The sheet on which the toner image is transferred is conveyed to the fixing unit 7 by the sheet conveying unit 6. After the toner image is fixed on the paper by the fixing unit 7, it is conveyed to the discharge unit 8. The sheet conveyed to the discharge unit 8 is discharged out of the multifunction machine 1.

[AC bias application control operation]
Next, the AC bias application control operation will be described.

When the developer inside the developing container 341 is supplied to the developing roller 342, it is first determined whether or not creep is formed on the developing roller 342 (S1). Specifically, the presence or absence of creep on the surface of the developing roller 342 and the creep amount are measured by the laser displacement meter 346a. When creep is not formed on the developing roller 342 (NO in S1), the AC bias having the waveform shown in FIG. 3 is applied from the first AC bias applying device 38 to the developing roller 342, and the second AC is applied. An AC bias having the waveform shown in FIG. 4 is applied from the bias applying device 39 to the supply roller 343. On the other hand, when creep is formed on the developing roller 342 (YES in S1), the absolute humidity in the vicinity of the developing roller 342 is detected. Then, a bias application condition to the developing roller 342 and the supply roller 343 is determined from the relationship information stored in the storage unit 91. For example, when the creep amount is 4 μm to 10 μm and the absolute humidity near the developing roller 342 is 14 to 50 g / m ³ , an effective bias G as shown in FIG. 6 is generated between the developing roller 342 and the supply roller 343. An AC bias is applied to the developing roller 342 and the supply roller 343 so as to act in between.

[effect]
Here, it is possible to prevent the image quality from being deteriorated by the creep formed on the developing roller 342 without using a special configuration or member. Further, since the creep information regarding the creep of the developing roller 342 is detected and the developer supply amount is adjusted based on the detected creep information, the developer supply amount can be adjusted efficiently.
[Second Embodiment]
As shown in FIG. 10, the multifunction machine 10 according to the second embodiment includes a document reading unit 11, an image forming unit 12, a transfer unit 13, a paper storage unit 14, a paper transport unit 15, and a fixing unit 16. A discharge unit 17 and an application control device 18. Here, since the configuration other than the application control device 18 is the same as the configuration of the multi-function device 1 according to the first embodiment, the description thereof is omitted. Further, members of the respective functional units will be described with reference to the multifunction machine 1 of the first embodiment.

  The application control device 18 is a device for controlling the first AC bias application device 38 and the second AC bias application device 39. FIG. 10 shows a block diagram of the application control device 18. Hereinafter, the application controller 18 will be described with reference to the block diagram of FIG.

  The application control device 18 includes a storage unit 181 (storage unit), a CPU, and the like. The application control device 18 includes a date / time information calculation unit 182 (date / time information calculation unit), a developer supply amount adjustment unit 183 (developer supply amount adjustment unit), a humidity detection unit 184 (humidity detection unit), and a creep information detection. Part (creep information detecting means) 185. The application control device 18 is a device that controls each functional unit by executing a program stored in the storage unit 181.

  The storage unit 181 stores various programs for controlling each functional unit. The storage unit 181 stores the relationship between the date / time information stored in the date / time information storage unit 30b of the process cartridge 30a and the AC bias applied to the supply roller 343 and the developing roller 342. The storage unit 181 stores a relationship between a time elapsed in a state in which the developing roller 342 and the regulating blade 344 that have been experimentally detected in advance are in contact with a creep amount of the developing roller 342. Specifically, a relationship as shown in FIG. 11 is stored.

  The date / time information calculation unit 182 is a part for calculating the elapsed time from the date / time information storage unit 30b provided in the process cartridge 30a while the developing roller 342 and the regulating blade 344 are in contact with each other. Specifically, when the previous use date / time is not stored in the date / time information storage unit 30b, the time elapsed from the manufacturing date / time and the current date / time of the process cartridge 30a in a state where the developing roller 342 and the regulating blade 344 are in contact with each other. Is calculated by the date / time information calculation unit 182. When the previous use date and time is stored in the date and time information storage unit 30b, the time and date information calculation unit 182 uses the time elapsed from the previous use date and time and the current date and time when the developing roller 342 and the regulating blade 344 are in contact with each other. Calculated.

  The developer supply amount adjustment unit 183 is a part that adjusts the developer supply amount based on the relationship information stored in the storage unit 181. For example, the first AC bias applying device 38 and the second AC bias applying device 39 are controlled so that the effective bias G shown in FIG. 6 acts between the developing roller 342 and the supply roller 343.

  The humidity detector 184 is a part for detecting the humidity around the developing roller 342. The humidity detection unit 184 includes a hygrometer 184 a and a thermometer 184 b disposed around the developing roller 342. The humidity detector 184 detects absolute humidity from the hygrometer 184a and the thermometer 184b.

  The creep information detection unit 185 is a part that detects the amount of creep based on the elapsed time in a state where the developing roller 342 and the regulating blade 344 are in contact based on the relationship shown in FIG. For example, when the elapsed time with the developing roller 342 and the regulating blade 344 in contact is 10 days, the creep information detecting unit 185 detects that the creep amount is 10 μm from the relationship of FIG.

[AC bias application control operation]
Next, the AC bias application control operation of the multifunction machine 10 will be described with reference to the flowchart of FIG. Note that the image forming operation of the multifunction device 10 is the same as the image forming operation of the multifunction device 1 of the first embodiment, and a description thereof will be omitted. When the image forming operation ends, the application control device 18 stores the date and time at that time in the storage unit 181.

  First, the time during which the developing roller 342 and the regulating blade 344 are in contact with each other is calculated from the date / time information stored in the date / time information storage unit 30b of the process cartridge 30a. The creep amount formed on the developing roller 342 is calculated from the calculated period (S11). Specifically, the creep amount is detected from the relationship (see FIG. 11) between the elapsed time and the developing roller 342 creep amount stored in the storage unit 181 while the developing roller 342 and the regulating blade 344 are in contact with each other. .

  Then, the absolute humidity in the vicinity of the developing roller 342 is calculated (S12). Thereafter, the AC applied to the developing roller 342 and the supply roller 343 based on the relationship between the absolute humidity and the creep amount stored in the storage unit 181 and the AC bias applied to the developing roller 342 and the supply roller 343. A bias is calculated (S13).

  Then, the calculated AC bias is applied to the developing roller 342 and the supply roller 343, respectively (S14).

[effect]
Here, since it is not necessary to actually measure the creep amount or the like, it is not necessary to provide a mechanism for actually measuring the creep amount or the like. For this reason, the cost and space for installing a mechanism for measuring the creep amount and the like can be reduced.

[Other Embodiments]
(A) In the above embodiment, the amount of developer supplied from the supply roller 343 to the development roller 342 is adjusted by adjusting the bias applied to the development roller 342 and the supply roller 343. However, the developer supply amount to the developing roller 342 may be increased by other methods. For example, the amount of developer supplied from the supply roller 343 to the developing roller 342 may be increased by increasing the number of rotations of the supply roller 343.

  (B) In the above embodiment, the creep amount of the developing roller 342 is measured using the reflection type laser displacement meter 346a. However, the present invention is not limited to this, and the contact type laser displacement meter, the developing roller, and the like are not limited thereto. The creep amount may be detected based on the density on 342.

  (C) In the above embodiment, the multifunction peripheral has been described. However, the present invention is not limited to this, and may be a copying machine, a printer, or the like.

  (D) In the above embodiment, the effective bias shown in FIG. 6 is applied between the developing roller 342 and the supply roller 343. However, the present invention is not limited to this, and is applied to, for example, the supply roller 343 shown in FIG. Alternatively, an alternating current bias having a waveform in which the alternating current bias is shifted in the negative direction as a whole may be applied.

  (E) Further, in the above-described embodiment, the date / time information calculation unit 182 calculates the elapsed time from the date / time information storage unit 30b provided in the process cartridge 30a while the developing roller 342 and the regulating blade 344 are in contact with each other. However, the present invention is not limited to this, and seconds, days, months, and years may be calculated.

1 is an overall schematic cross-sectional view of a multifunction machine according to an embodiment of the present invention. The elements on larger scale of an image formation part. 6 shows a waveform of an AC bias applied to the developing roller during an image forming operation. 6 shows a waveform of an AC bias applied to a supply roller during an image forming operation. FIG. 4 is a diagram illustrating an effective bias that acts between a developing roller and a supply roller during an image forming operation. The figure which shows an example of the effective bias in the state in which creep has arisen. The functional block diagram of an application control apparatus. The figure which shows the relationship between creep amount and humidity, and the applied alternating current bias. 6 is a flowchart showing an application control operation. FIG. 9 is a functional block diagram of a multifunction machine according to a second embodiment. The figure which shows the relationship between the creep amount of the multifunctional machine which concerns on 2nd Embodiment, and a storage period. 9 is a flowchart showing the operation of the multifunction machine according to the second embodiment.

Explanation of symbols

1 MFP (image forming device)
3 Image forming unit 30a Process cartridge 31 Photosensitive drum (electrostatic latent image carrier)
91 Storage unit (storage means)
92 Developer supply amount adjusting section (Developer supply amount adjusting means)
93 Humidity detector (humidity detector)
94 Developer Supply Device 181 Storage Unit (Storage Unit)
182 Date / time information calculation unit (date / time information calculation means)
183 Developer supply amount adjusting unit (supply amount adjusting means)
184 Humidity detector (humidity detection means)
185 Creep information detection unit (creep information detection means)
342 Development roller 343 Supply roller (supply member)
344 Restriction blade (regulation member)
346 Creep information detection device (creep information detection means)

Claims (9)

A developer supply device that supplies developer to a developing roller that supplies developer to an electrostatic latent image carrier of an image forming apparatus,
A supply member capable of supplying a developer to the developing roller;
Creep information detecting means for detecting creep information relating to creep of the developing roller;
A supply amount adjusting means for adjusting a supply amount of the developer to the developing roller of the supply member based on the creep information detected by the creep information detecting means;
A developer supply device. The developing roller and the supply member are each applied with an AC bias during an image forming operation,
The supply amount adjusting means adjusts at least one of an AC bias applied to the developing roller and an AC bias applied to the supply member, so that the developer supply amount of the supply member to the developing roller is adjusted. Adjust the
The developer supply device according to claim 1.   The developer supply device according to claim 2, wherein the supply amount adjusting unit increases a time during which a difference between the AC bias applied to the developing roller and the AC bias applied to the supply member is generated.   The supply amount adjusting unit includes an AC bias applied to the developing roller and the supply according to a time during which a difference between the AC bias applied to the developing roller and the AC bias applied to the supplying member is generated. The developer supply device according to claim 3, wherein a value of the AC bias applied to the member is adjusted. A regulating member capable of regulating the thickness of the developer layer is in contact with the developing roller,
The creep information detecting means detects a creep amount on the surface of the developing roller;
The developer supply device according to claim 1. A storage unit capable of storing a time when the restricting member is arranged to contact the developing roller and a date and time when the developing roller is used;
The creep information detecting means detects creep information based on a date on which the regulating member is disposed so as to contact the developing roller and a date on which the developing roller is used;
The developer supply device according to claim 5. A humidity detecting means for detecting the humidity around the developing roller;
The developer supply amount adjusting means adjusts the developer supply amount of the supply member to the developing roller according to the humidity detected by the humidity detecting means;
The developer supply device according to claim 1. An electrostatic latent image carrier capable of carrying an electrostatic latent image on the surface;
A developing roller capable of supplying a developer to the electrostatic latent image carrier;
A developer supply device according to claim 1, capable of supplying a developer to the developing roller;
With
Process cartridge. An electrostatic latent image carrier capable of carrying an electrostatic latent image on the surface;
A developing roller capable of supplying a developer to the electrostatic latent image carrier;
A developer supply device according to claim 1, capable of supplying a developer to the developing roller;
An image forming apparatus comprising:

Images