JP7192266B2 - Image forming apparatus and image forming system - Google Patents

Description

The present invention relates to an image forming apparatus and an image forming system.

In general, image forming apparatuses (printers, copiers, facsimiles, etc.) using electrophotographic process technology irradiate (expose) laser light based on image data to a charged photosensitive drum (image carrier). forms an electrostatic latent image. Then, by supplying toner from a developing device to the photosensitive drum on which the electrostatic latent image is formed, the electrostatic latent image is visualized and a toner image is formed. Further, after the toner image is directly or indirectly transferred to the paper, the toner image is formed on the paper by heating and pressurizing it in the fixing nip.

By the way, in the process of supplying the toner from the developing device to the photosensitive drum, the toner may scatter and accumulate in the developing device. In this case, the scattered and deposited toner spills (falls off) from the developing device, resulting in an image defect. Therefore, in order to suppress the occurrence of such image defects, a vibrating device for vibrating the developing device has been proposed.

For example, Japanese Patent Application Laid-Open No. 2002-200000 discloses an image forming apparatus capable of efficiently collecting toner deposited on a toner receiving member by vibrating the toner receiving member.

JP 2018-45012 A

However, it is unclear to what extent the accumulated toner could be removed by the vibration of the vibrating device. Therefore, if the amount of vibration is insufficient, the accumulated toner may spill out of the developing device, causing continuous image defects. On the other hand, if the amount of vibration is greater than necessary, there is a problem that the vibration application time increases, which may increase the downtime of the image forming process.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and an image forming system capable of suppressing an increase in downtime while reducing toner spillage.

In order to achieve the above object, the image forming apparatus of the present invention includes:
a developer container containing toner;
a vibration unit that vibrates the developer container;
a detection unit that detects the amount of toner that has fallen out of the developer container due to the vibration of the vibrating unit;
a determination unit that determines whether or not vibration by the vibration unit is necessary based on the detection result of the detection unit;
Prepare.

In order to achieve the above object, the image forming system of the present invention comprises:
a developer container containing toner;
a vibration unit that vibrates the developer container;
a detection unit that detects the amount of toner that has fallen out of the developer container due to the vibration of the vibrating unit;
a determination unit that determines whether or not vibration by the vibration unit is necessary based on the detection result of the detection unit;
Prepare.

According to the present invention, it is possible to suppress an increase in downtime while reducing toner spillage.

1 is a diagram schematically showing the overall configuration of an image forming apparatus according to an embodiment of the invention; FIG. FIG. 2 is a diagram showing main parts of a control system of the image forming apparatus according to the embodiment of the invention; 4 is a flow chart showing an example of the operation of a vibrating section; 3 is a diagram schematically showing a partial configuration of an image forming apparatus according to modification 1; FIG. 9 is a flow chart showing an example of the operation of the vibrating unit in Modification 1. FIG. FIG. 10 is a diagram schematically showing the configuration of a developing device in Modification 2; 10 is a flow chart showing an example of the operation of the vibrating unit in Modification 2. FIG.

Hereinafter, this embodiment will be described in detail based on the drawings. FIG. 1 is a diagram schematically showing the overall configuration of an image forming apparatus 1 according to an embodiment of the invention. FIG. 2 is a diagram showing the main part of the control system of the image forming apparatus 1 according to this embodiment.

The image forming apparatus 1 shown in FIG. 1 is an intermediate transfer type color image forming apparatus using electrophotographic process technology. That is, the image forming apparatus 1 primarily transfers each color toner image of Y (yellow), M (magenta), C (cyan), and K (black) formed on the photosensitive drum 413 onto the intermediate transfer belt 421, An image is formed by superimposing four-color toner images on the intermediate transfer belt 421 and then secondary-transferring them onto a sheet S (recording medium).

In the image forming apparatus 1, the photosensitive drums 413 corresponding to the four colors of YMCK are arranged in series in the running direction of the intermediate transfer belt 421, and the toner images of the respective colors are sequentially transferred onto the intermediate transfer belt 421 in one procedure. A tandem system is used.

As shown in FIG. 2, the image forming apparatus 1 includes an image reading section 10, an operation display section 20, an image processing section 30, an image forming section 40, a sheet conveying section 50, a fixing section 60, a vibrating section 80, and a detecting section 90. and a control unit 100 .

The control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and the like. The CPU 101 reads out a program corresponding to the processing content from the ROM 102, develops it in the RAM 103, and centrally controls the operation of each block of the image forming apparatus 1 in cooperation with the developed program. At this time, various data stored in the storage unit 72 are referred to. The storage unit 72 is composed of, for example, a nonvolatile semiconductor memory (so-called flash memory) or a hard disk drive.

The control unit 100 transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via the communication unit 71. conduct. For example, the control unit 100 receives image data (input image data) transmitted from an external device, and forms an image on the paper S based on this image data. The communication unit 71 is composed of a communication control card such as a LAN card, for example.

The image reading unit 10 includes an automatic document feeder 11 called an ADF (Auto Document Feeder), a document image scanning device 12 (scanner), and the like.

The automatic document feeder 11 transports the document D placed on the document tray by the transport mechanism and sends it to the document image scanning device 12 . The automatic document feeder 11 makes it possible to continuously read images (including both sides) of a large number of documents D placed on the document tray at once.

The document image scanning device 12 optically scans the document conveyed onto the contact glass from the automatic document feeder 11 or the document placed on the contact glass, and converts the light reflected from the document into a CCD (Charge Coupled Device). ) An image is formed on the light-receiving surface of the sensor 12a, and the document image is read. The image reading unit 10 generates input image data based on the result of reading by the document image scanning device 12 . Predetermined image processing is performed on the input image data in the image processing section 30 .

The operation display unit 20 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 21 and an operation unit 22 . The display unit 21 displays various operation screens, image status display, operation status of each function, etc. according to a display control signal input from the control unit 100 . The operation unit 22 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs operation signals to the control unit 100 .

The image processing unit 30 includes a circuit or the like that performs digital image processing on input image data in accordance with initial settings or user settings. For example, the image processing unit 30 performs gradation correction based on gradation correction data (gradation correction table) under the control of the control unit 100 . The image processing unit 30 also performs various types of correction processing such as color correction and shading correction, compression processing, etc., on the input image data, in addition to tone correction. The image forming section 40 is controlled based on the image data subjected to these processes.

The image forming section 40 includes image forming units 41Y, 41M, 41C, and 41K, an intermediate transfer unit 42, and an image forming unit 41Y, 41M, 41C, and 41K for forming images with colored toners of Y, M, C, and K components based on input image data. etc.

Image forming units 41Y, 41M, 41C, and 41K for the Y, M, C, and K components have similar configurations. For convenience of illustration and description, common components are denoted by the same reference numerals, and Y, M, C, or K is added to the reference numerals to distinguish them. In FIG. 1, only the components of the image forming unit 41Y for the Y component are denoted by reference numerals, and the components of the other image forming units 41M, 41C, and 41K are omitted.

The image forming unit 41 includes an exposure device 411, a developing device 412 (corresponding to the "developing section" of the invention), a photosensitive drum 413 (corresponding to the "image carrier" of the invention), a charging device 414, and a drum cleaning device. 415 and the like.

The photosensitive drum 413 is, for example, an aluminum conductive cylindrical body (aluminum tube) having a drum diameter of 80 [mm], and an undercoat layer (UCL) and a charge generation layer (CGL) on the peripheral surface of the drum. Generation Layer) and a charge transport layer (CTL: Charge Transport Layer) are sequentially laminated to form a negatively charged organic photoreceptor (OPC: Organic Photo-conductor). The charge-generating layer is made of an organic semiconductor in which a charge-generating material (eg, phthalocyanine pigment) is dispersed in a resin binder (eg, polycarbonate), and generates a pair of positive and negative charges when exposed by the exposure device 411 . The charge-transporting layer consists of a hole-transporting material (electron-donating nitrogen-containing compound) dispersed in a resin binder (e.g., polycarbonate resin), and transports positive charges generated in the charge-generating layer to the surface of the charge-transporting layer. do.

The control unit 100 rotates the photoreceptor drum 413 at a constant peripheral speed by controlling the drive current supplied to a drive motor (not shown) that rotates the photoreceptor drum 413 .

The charging device 414 uniformly charges the surface of the photosensitive drum 413 having photoconductivity to a negative polarity. The exposure device 411 is composed of, for example, a semiconductor laser, and irradiates the photosensitive drum 413 with laser light corresponding to an image of each color component. A positive charge is generated in the charge generation layer of the photoreceptor drum 413 and transported to the surface of the charge transport layer, thereby neutralizing the surface charge (negative charge) of the photoreceptor drum 413 . An electrostatic latent image of each color component is formed on the surface of the photosensitive drum 413 due to a potential difference with the surroundings.

As the charging device 414, a corona discharger that uniformly charges the surface of the photosensitive drum 413 to a negative polarity by corona discharge is used. Charging device 414 has a charging wire and a shield electrode. The charging wire is arranged along the width direction (longitudinal direction) of the photosensitive drum 413 . By supplying a high voltage to the charging wire, a corona discharge is generated between the charging wire and the shield electrode surrounding the charging wire, and the surface of the photosensitive drum 413 arranged facing the shield electrode is uniformly distributed. charged to

The developing device 412 is a two-component developing device that adheres toner of each color component to the surface of the photosensitive drum 413 to visualize the electrostatic latent image and form a toner image. The developing device 412 forms a toner image on the surface of the photosensitive drum 413 by supplying the toner contained in the developer to the photosensitive drum 413 . The developing device 412 has a developing container 412A containing developer. Note that the area where the toner image is formed on the surface of the photoreceptor drum 413 may be referred to as an "image forming area". Also, the area between the image forming areas on the surface of the photoreceptor drum 413 may be referred to as "paper space" or "non-image forming area".

The drum cleaning device 415 has a drum cleaning blade or the like that slides on the surface of the photoreceptor drum 413, and removes transfer residual toner remaining on the surface of the photoreceptor drum 413 after the primary transfer.

The intermediate transfer unit 42 includes an intermediate transfer belt 421 (corresponding to the "image carrier" of the invention), a primary transfer roller 422, a plurality of support rollers 423, a secondary transfer roller 424, a belt cleaning device 426, and the like. Similarly to the "image forming area" and "between sheets" of the photosensitive drum 413, the area where the toner image is formed on the surface of the intermediate transfer belt 421 is the "image forming area" and the space between the image forming areas. The area may be referred to as "paper space" or "non-image forming area".

The intermediate transfer belt 421 is an endless belt and stretched around a plurality of support rollers 423 in a loop. At least one of the plurality of supporting rollers 423 is configured as a driving roller, and the others are configured as driven rollers. For example, it is preferable that the roller 423A arranged downstream in the belt running direction from the primary transfer roller 422 for the K component is a drive roller. This makes it easier to keep the running speed of the belt in the primary transfer portion constant. As the drive roller 423A rotates, the intermediate transfer belt 421 runs in the arrow A direction at a constant speed.

The intermediate transfer belt 421 is a conductive and elastic belt, and has a high-resistance layer with a volume resistivity of 8 to 11 [logΩ·cm] on its surface. Intermediate transfer belt 421 is rotationally driven by a control signal from control unit 100 . The material, thickness and hardness of the intermediate transfer belt 421 are not limited as long as they have conductivity and elasticity.

The intermediate transfer belt 421 specifically has a laminated structure consisting of a base layer and a surface layer. The base material layer is made of a synthetic resin in which a conductive material or the like is dispersed. The substrate layer may have a single-layer structure or a multi-layer structure of two or more layers.

The primary transfer roller 422 is arranged on the inner circumferential surface side of the intermediate transfer belt 421 so as to face the photosensitive drum 413 of each color component. A primary transfer nip for transferring a toner image from the photosensitive drum 413 to the intermediate transfer belt 421 is formed by pressing the primary transfer roller 422 against the photosensitive drum 413 with the intermediate transfer belt 421 therebetween.

The secondary transfer roller 424 is arranged on the outer peripheral surface side of the intermediate transfer belt 421 so as to face the backup roller 423B arranged on the downstream side of the drive roller 423A in the belt running direction. A secondary transfer nip for transferring the toner image from the intermediate transfer belt 421 to the sheet S is formed by pressing the secondary transfer roller 424 against the backup roller 423B with the intermediate transfer belt 421 therebetween. A secondary transfer belt is stretched in a loop shape around a plurality of support rollers including the secondary transfer roller 424 .

When the intermediate transfer belt 421 passes through the primary transfer nip, the toner images on the photosensitive drum 413 are sequentially superposed on the intermediate transfer belt 421 and primarily transferred. Specifically, a primary transfer bias is applied to the primary transfer roller 422, and a charge opposite to that of the toner is applied to the back side of the intermediate transfer belt 421 (the side that contacts the primary transfer roller 422), thereby forming the toner image. It is electrostatically transferred to the intermediate transfer belt 421 .

After that, when the sheet S passes through the secondary transfer nip, the toner image on the intermediate transfer belt 421 is secondarily transferred onto the sheet S. FIG. Specifically, a secondary transfer bias is applied to the secondary transfer roller 424, and an electric charge having a polarity opposite to that of the toner is applied to the back surface side of the sheet S (the side in contact with the secondary transfer roller 424), thereby forming a toner image. is electrostatically transferred to the paper S. The sheet S onto which the toner image has been transferred is conveyed toward the fixing section 60 .

The belt cleaning device 426 has a belt cleaning blade or the like that slides on the surface of the intermediate transfer belt 421, and removes transfer residual toner remaining on the surface of the intermediate transfer belt 421 after secondary transfer.

The fixing unit 60 includes a fixing belt 61, a heating roller 62, an upper pressure roller 63 arranged on the fixing surface (the surface on which the toner image is formed) of the paper S, and the back surface of the paper S (the surface opposite to the fixing surface). ) side, a heat source 60C, and the like. The heating roller 62 incorporates a heat source 60</b>C that heats the fixing belt 61 . By pressing the lower pressure roller 65 against the upper pressure roller 63, a fixing nip is formed in which the paper S is nipped and conveyed.

The fixing unit 60 fixes the toner image to the paper S by heating and pressurizing the paper S conveyed after the toner image is secondarily transferred at the fixing nip. The fixing section 60 is arranged inside the fixing device F as a unit.

The paper conveying unit 50 includes a paper feeding unit 51, a paper discharging unit 52, a conveying path unit 53, and the like. The three paper feed tray units 51a to 51c that constitute the paper feed unit 51 store paper S (standard paper, special paper) identified based on basis weight, size, etc., for each preset type. . The transport path portion 53 has a plurality of transport roller pairs including a registration roller pair 53a.

The paper sheets S accommodated in the paper feed tray units 51 a to 51 c are sent out one by one from the top and conveyed to the image forming section 40 by the conveying path section 53 . At this time, the skew of the fed sheet S is corrected and the transport timing is adjusted by the registration roller section in which the registration roller pair 53a is arranged. Then, in the image forming section 40 , the toner images on the intermediate transfer belt 421 are collectively secondary-transferred onto one surface of the sheet S, and the fixing section 60 performs a fixing process. The sheet S on which the image has been formed is discharged to the outside of the apparatus by a discharge section 52 having a discharge roller 52a.

By the way, in the process of supplying toner from the developing device 412 to the photosensitive drum 413 , the toner may scatter and accumulate inside the developing device 412 . In this case, the scattered and accumulated toner falls off (spills out) from the developing device 412, resulting in an image defect. In order to suppress the occurrence of image defects, the image forming apparatus 1 according to the present embodiment includes a vibrating section 80 for forcibly removing the accumulated toner.

The vibrating section 80 vibrates the developer container 412A. The control section 100 controls the vibrating section 80 to vibrate the developer container 412A.

By vibrating the developing container 412A with the vibrating section 80, the toner deposited on the developing container 412A can be forcibly removed. However, it is unclear to what extent the accumulated toner can be removed by the vibration of the vibrating section 80 . If the amount of vibration (also referred to as the amount of vibration) is insufficient, the toner may remain deposited and then fall off, causing continuous image defects. If the amount of vibration becomes more than necessary, the vibration application time increases, which may increase the downtime of the image forming process.

Therefore, in order to eliminate the excess or deficiency of the amount of vibration, the image forming apparatus 1 according to the present embodiment includes a detection method for detecting the amount of toner that has accumulated in the developing container 412A and fallen off due to the vibration of the vibrating section 80. A section 90 is provided. The detection unit 90 is arranged downstream of the fixing unit 60 in the paper transport direction in the transport path unit 53 . The control unit 100 vibrates the developer container 412A when a predetermined vibration start condition is satisfied before image formation in which a toner image is formed on the sheet S based on the input image data. It controls the vibrator 80 . Here, the start condition of vibration means, for example, the case of starting every predetermined number of printed sheets (for example, 5000 sheets). Note that another start condition may be, for example, turning off the sub power of the image forming apparatus 1 at night and turning on the sub power of the image forming apparatus 1 first thing in the morning of the next day. A combination may be used.

When controlling the vibrating section 80 to vibrate the developer container 412A, the control section 100 controls the image forming section 40 so that a blank image is formed on the sheet S (recording medium). The detection unit 90 detects the amount of toner falling off by detecting the amount of toner adhering to the area of the sheet S where the white background image is formed. Note that the sheet S (recording medium) may be referred to as an "image carrier".

In the present embodiment, the toner amount includes the number of dots of toner that are equal to or larger than a predetermined size. The detection unit 90 has a scanner capable of reading dots. The detection unit 90 counts the number of dots having a predetermined size or larger among the dots read by the scanner.

The control unit 100 has a function as a determination unit that determines whether vibration by the vibration unit 80 is necessary based on the number of dots counted by the detection unit 90 . Specifically, the control unit 100 (determination unit) determines that the vibration by the vibration unit 80 is necessary when the number of dots counted by the detection unit 90 exceeds a specified value. On the other hand, the controller 100 determines that the vibration by the vibrating section 80 is unnecessary when the number of dots of toner having a predetermined size or larger is equal to or smaller than the specified value.

When the control section 100 determines that vibration by the vibration section 80 is necessary, the control section 100 controls the vibration section 80 so as to vibrate the developer container 412A. In other words, the vibrating section 80 vibrates again when it is determined that vibration is necessary. On the other hand, when the controller 100 determines that the vibration by the vibration generator 80 is unnecessary, it does not control the vibration of the developer container 412A. In other words, the vibrating section 80 terminates the vibrating when it is determined that the vibrating is unnecessary. As a result, excess or deficiency of the vibration amount can be eliminated.

Next, an example of the operation of vibrating section 80 in the present embodiment will be described with reference to FIG. FIG. 3 is a flow chart showing an example of the operation of the vibrating section 80. As shown in FIG. This flow is started when the image forming apparatus 1 is activated.

First, the control unit 100 determines whether or not conditions for starting vibration are satisfied (step S100). If the excitation start condition is satisfied (step S100: YES), the process transitions to step S110. If the excitation start condition is not satisfied (step S100: NO), the process returns to before step S100.

In step S<b>110 , the control unit 100 performs control for starting vibration by the vibrating unit 80 .

Next, in step S120, the control section 100 controls the image forming section 40 to form a white background image on the sheet S. FIG.

Next, in step S130, the control unit 100 acquires the amount of toner falling off in the area of the sheet S detected by the detection unit 90 where the white background image is formed.

Next, in step S140, the control unit 100 determines whether or not the amount of toner falling off detected by the detection unit 90 is equal to or less than a specified value. If the amount of toner falling off is equal to or less than the specified value (step S140: YES), the process transitions to step S150. If the amount of toner falling off exceeds the specified value (step S140: NO), the process returns to before step S120.

In step S<b>150 , the control unit 100 performs control to terminate the vibration application by the vibration application unit 80 . After that, the process ends.

According to the image forming apparatus 1 of the above-described embodiment, the developer container 412A containing the toner, the vibration unit 80 that vibrates the developer container 412A, and the developer container 412A are separated from the developer container 412A by the vibration of the vibration unit 80. A detection unit 90 that detects the amount of toner falling off, and a control unit 100 (determination unit) that determines whether vibration by the vibration unit 80 is necessary based on the detection result of the detection unit 90. .

Accordingly, when it is determined that vibration is necessary, vibration is performed again. If it is determined that the excitation is unnecessary, the excitation ends. As a result, it is possible to prevent the amount of vibration from becoming insufficient, so it is possible to reduce toner spillage. In addition, since it is possible to prevent the amount of vibration from increasing more than necessary, it is possible to suppress an increase in downtime of the image forming process.

Next, Modification 1 of the present embodiment will be described with reference to FIG. FIG. 4 is a diagram schematically showing a partial configuration of an image forming apparatus 1 according to Modification 1. As shown in FIG. In Modification 1, configurations different from those of the above-described embodiment will be mainly described, and similar configurations will be given the same reference numerals and descriptions thereof will be omitted.

In the above-described embodiment, the detecting section 90 is arranged downstream of the fixing section 60 in the paper conveying direction in the conveying path section 53 . The detection unit 90 detects the amount of toner adhering to the area of the sheet S where the white background image is formed.

On the other hand, in Modification 1, the detector 90A is arranged on the surface side of the intermediate transfer belt 421, as shown in FIG. The detection unit 90A detects the amount of toner adhering to the area where the white background image is formed between the sheets of the intermediate transfer belt 421 . The detection unit 90A has, for example, a line sensor in which imaging elements are linearly arranged in a line. The detection unit 90A counts the number of dots having a predetermined size or larger among the dots captured by the line sensor.

In Modified Example 1, the control unit 100 controls the image forming unit 40 to form a white background image between the sheets of the intermediate transfer belt 421 when the previous amount of toner falling off exceeds the specified value, and , the vibrating section 80 is controlled to vibrate the developer container 412A. As a result, the toner dropped from the developer container 412A adheres to the area where the white background image is formed between the sheets. Here, the "previous amount of toner falling off" is the amount of toner falling off due to the vibration applied last time when it was determined that the vibration was necessary. In the following description, as a prerequisite, it is assumed that the previous amount of toner falling off has been acquired.

Next, an example of the operation of the vibrating section 80 in Modification 1 will be described with reference to FIG. FIG. 5 is a flow chart showing an example of the operation of the vibrating section 80 in Modification 1. As shown in FIG. This flow starts by executing image formation based on the input image data.

First, the control unit 100 determines whether or not conditions for starting vibration are satisfied (step S200). If the excitation start condition is satisfied (step S200: YES), the process transitions to step S210. If the excitation start condition is not satisfied (step S200: NO), the process returns to before step S200.

In step S210, control unit 100 determines whether or not the previous amount of toner falling off is equal to or less than a specified value. If the previous amount of toner falling off is equal to or less than the specified value (step S210: YES), the process ends. If the previous amount of toner falling off exceeds the specified value (step S210: NO), the process transitions to step S220.

In step S<b>220 , the control unit 100 performs control for starting vibration by the vibrating unit 80 .

Next, in step S<b>230 , the control section 100 controls the image forming section 40 to form a blank image between the sheets of the intermediate transfer belt 421 .

Next, in step S<b>240 , the control section 100 performs control to terminate the excitation by the excitation section 80 .

Next, in step S250, the control unit 100 acquires the amount of toner falling off in the area where the white background image is formed between the sheets detected by the detection unit 90A, and returns the process to before step S210.

According to the image forming apparatus 1 of Modification 1, the amount of toner falling off is detected on the intermediate transfer belt 421 and not detected on the sheet S, so consumption of the sheet S can be suppressed. Further, according to the image forming apparatus 1 in the first modification, the control unit 100 controls the image forming unit 40 so as to transfer the white background image between the sheets of the intermediate transfer belt 421, and adds the developer container 412A. The vibrator 80 is controlled to vibrate. As a result, the toner dropped from the developer container 412A adheres to the area where the white background image is formed between the sheets. As a result, it is possible to apply vibration by the vibration applying unit 80 and detect the amount of toner falling off during image formation in which a toner image is formed on the sheet S based on input image data. In other words, since vibration and the like can be performed by the vibrating section 80 during execution of a job, it is possible to reduce the downtime of the image forming process as compared with the above-described embodiment performed before execution of the job.

It should be noted that although the detection unit 90A detects the amount of toner adhering to the intermediate transfer belt 421 in the first modification, the present invention is not limited to this. may be detected. In this case as well, the control unit 100 controls the image forming unit 40 to transfer the blank image between the sheets of the photosensitive drum 413, and controls the vibrating unit 80 to vibrate the developer container 412A. do. As a result, the toner dropped from the developer container 412A adheres to the area where the white background image is formed between the sheets.

Further, in the above modification 1, the control unit 100 controls the developer container 412A when the toner falling off from the developer container 412A adheres between the sheets of the image carrier (for example, the intermediate transfer belt 421 and the photosensitive drum 413). The vibrating section 80 may be controlled so that the amount of vibration for vibrating the developer container 412A is smaller than the amount of vibration for vibrating the developer container 412A when the toner does not adhere between the sheets of the image carrier. By reducing the amount of vibration, even if the number of times of vibration increases, the vibration is applied by the vibration section 80 and the amount of toner falling off is detected between sheets, so downtime is not increased. Also, the amount of vibration is reduced to reduce the amount of toner falling off per vibration. As a result, by fine-tuning the number of times of vibration, it is possible to adjust the total amount of vibration with high accuracy. can.

When the vibration amount is the vibration force, the controller 100 vibrates the developer container 412A when the toner dropped from the developer container 412A adheres to the paper space of the image carrier. The vibrating section 80 is controlled so that the force is smaller than the vibrating force that vibrates the developer container 412A when the toner does not adhere between the sheets of the image carrier. Further, when the vibration amount is the vibration time, the controller 100 vibrates the developer container 412A when the toner falling out of the developer container 412A adheres between the sheets of the image carrier. The vibrating section 80 is controlled so that the time is shorter than the vibrating time for vibrating the developer container 412A when the toner does not adhere between the sheets of the image carrier. Further, the control unit 100 may control the vibrating unit 80 so as to adjust both the vibrating force and the vibrating time, that is, to reduce the vibrating force and shorten the vibrating time. .

Next, Modification 2 of the present embodiment will be described. Also in Modification 2, configurations different from those of the above-described embodiment will be mainly described, and similar configurations will be given the same reference numerals and descriptions thereof will be omitted.

FIG. 6 is a diagram schematically showing the configuration of the developing device 412 in Modification 2. As shown in FIG. As shown in FIG. 6, the developing device 412 has a developing roller 412B that faces the photosensitive drum 413 and conveys the developer toward the developing nip that faces the photosensitive drum 413. In addition, the developing roller 412B A collecting roller 412C is provided for collecting the toner from the toner. The recovery roller 412C is configured in a non-grounded state (floating state). A magnet roller, for example, is used for the collection roller 412C.

In the developing device 412 having the recovery roller 412C, the toner is scattered and deposited on the developer container 412A and also deposited on the recovery roller 412C. When the toner deposited on the collecting roller 412C is to be removed, it is easier to remove the toner from the area where the halftone image is formed than the area where the white background image is formed. Therefore, for example, when the accumulated toner is forcibly removed from the developing device 412 having the collecting roller 412C, after the toner is removed in the area where the white background image is formed, the removed toner is used to form the halftone image. be attached to the area to be covered. Specifically, the control unit 100 controls the image forming unit 40 to form a halftone image when the amount of toner attached to the area where the white background image is formed (amount of toner falling off) is equal to or less than a specified value, In addition, the vibrating section 80 is controlled so as to vibrate the developer container 412A. As a result, the toner dropped out of the developer container 412A from the collection roller 412C adheres to the area where the halftone image is formed. The detection unit 90 detects the amount of toner adhered to the area of the sheet S where the halftone image is formed (amount of toner falling off).

Next, an example of the operation of the vibrating section 80 in Modification 2 will be described with reference to FIG. 7 . FIG. 7 is a flowchart showing an example of the operation of the vibrating section 80 in Modification 2. As shown in FIG. Note that the processing from step S300 to step S330 shown in FIG. 7 is the same as the processing from step S100 to step S130 shown in FIG. 3, so description thereof will be omitted.

In step S340 shown in FIG. 7, control unit 100 determines whether or not the amount of toner falling off in the area where the white background image is formed is equal to or less than a specified value. If the amount of toner falling off exceeds the specified value (step S340: NO), the process returns to before step S320. If the amount of toner falling off is equal to or less than the specified value (step S340: YES), the process transitions to step S350.

In step S<b>350 , the control section 100 controls the image forming section 40 to form a halftone image on the sheet S. FIG.

Next, in step S360, the control unit 100 acquires the amount of toner falling off in the region where the halftone image detected by the detection unit 90 is formed.

Next, in step S370, control unit 100 determines whether or not the amount of toner falling off in the area where the halftone image is formed is equal to or less than a specified value. If the amount of toner falling off exceeds the specified value (step S370: NO), the process returns to before step S350. If the amount of toner falling off is equal to or less than the specified value (step S370: YES), the process transitions to step S380.

In step S<b>380 , the control unit 100 performs control to terminate the vibration application by the vibration application unit 80 . After that, the process ends.

According to the image forming apparatus 1 of Modified Example 2, the control unit 100 forms a halftone image on the sheet S when the amount of toner falling off in the area where the white background image is formed on the sheet S is equal to or less than the specified value. , and the vibrating section 80 is controlled to vibrate the developer container 412A. As a result, the toner dropped out of the developer container 412A from the collection roller 412C adheres to the area where the halftone image is formed. The detection unit 90 detects the amount of toner adhered to the area where the halftone image is formed (amount of toner falling off). By allowing the toner to fall off in the area where the halftone image is formed, the toner can be easily removed. As a result, the toner does not remain accumulated on the collection roller 412C, and it is possible to further reduce the spillage of the toner accumulated on the collection roller 412C after the vibration, thereby preventing the continuous occurrence of defective images. You can increase the effect.

Note that in the second modification, the control unit 100 controls the image forming unit 40 to form a blank image between the sheets of the image carrier (for example, the intermediate transfer belt 421 and the photosensitive drum 413), and , the vibrating unit 80 is controlled to vibrate the developer container 412A, and if the amount of toner adhering to the area where the white background image is formed between the sheets (the amount of toner falling off) is greater than or equal to a specified value, a halftone image is generated between the sheets. , and the vibrating section 80 is controlled to vibrate the developer container 412A. As a result, the toner dropped from the developer container 412A adheres to the area where the halftone image is formed between the sheets.

Note that in Modification 2 above, a specified value to be compared with the amount of toner falling off in an area where a white background image is formed, a specified value to be compared with the amount of toner falling off in an area where a halftone image is formed, Although the values are the same, they may be different from each other. By making the prescribed values different from each other, it is possible to adjust the amount of toner falling off for each vibration.

In addition, the above-described embodiments are merely examples of specific implementations of the present invention, and the technical scope of the present invention should not be construed to be limited by these. Thus, the invention may be embodied in various forms without departing from its spirit or essential characteristics.

The present invention can be applied to an image forming system including a plurality of units including the image forming apparatus 1. FIG. The plurality of units includes, for example, external devices such as humidifiers, networked controllers, and the like.

1 Image forming apparatus 10 Image reading unit 20 Operation display unit 21 Display unit 22 Operation unit 30 Image processing unit 40 Image forming unit 412 Developing device 412A Developing container 412B Developing roller 412C Recovery roller 413 Photoreceptor drum 421 Intermediate transfer belt 50 Paper transport unit 60 fixing unit 71 communication unit 72 storage unit 80 vibrating unit 90, 90A detection unit 100 control unit

Claims (10)

a developer container containing toner;
a vibration unit that vibrates the developer container;
a detection unit that detects the amount of toner falling off from the developer container and adhering to the image bearing member due to the vibration of the vibrating unit;
a determination unit that determines whether or not the detected amount of falling off toner exceeds a specified value;
controlling the vibrating unit to vibrate the developer container when the amount of toner falling off exceeds a specified value; and vibrating the developing container when the amount of toner falling off does not exceed the specified value. a control unit that does not perform vibration control;
An image forming apparatus comprising: When a white background image is formed on the image carrier, the amount of toner falling off includes the amount of toner adhered to the area where the white background image is formed.
The image forming apparatus according to claim 1. When a halftone image is formed on the image carrier, the amount of toner falling off includes the amount of toner adhered to the area where the halftone image is formed.
The image forming apparatus according to claim 1. The image carrier is a recording medium,
The image forming apparatus according to any one of claims 1 to 3. The image carrier is a photoreceptor,
The image forming apparatus according to any one of claims 1 to 3. The image carrier is an intermediate transfer member,
The image forming apparatus according to any one of claims 1 to 3. When the toner falling out of the developer container adheres to the image bearing member, either the photoreceptor or the intermediate transfer member,
The controller controls a vibration amount for vibrating the developer container when the toner falling out of the developer container adheres to a non-image forming area, which is an area between the image forming areas on the image carrier. controlling the vibrating section so as to be smaller than an amount of vibration for vibrating the developer container when the toner does not adhere to the non-image forming area on the image carrier;
The image forming apparatus according to claim 1. The excitation amount is an excitation force,
The image forming apparatus according to claim 7. The amount of excitation is an excitation time,
The image forming apparatus according to claim 7 or 8. a developer container containing toner;
a vibration unit that vibrates the developer container;
a detection unit that detects the amount of toner falling off from the developer container and adhering to the image bearing member due to the vibration of the vibrating unit;
a determination unit that determines whether or not the detected amount of falling off toner exceeds a specified value;
controlling the vibrating unit to vibrate the developer container when the amount of toner falling off exceeds a specified value; and vibrating the developing container when the amount of toner falling off does not exceed the specified value. a control unit that does not perform vibration control;
An imaging system comprising:

Images