JP2009069582A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control application of a lubricant so that an amount of the lubricant on an image carrier may be always constant. <P>SOLUTION: An area on the image carrier is divided into a plurality of areas, and an image amount of each of the plurality of areas is detected, then the application of the lubricant is controlled based on a detection value. For example, when the image amount in any of the plurality of areas becomes equal to or above a predetermined threshold, the application of the lubricant is performed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, and a fax machine, and more particularly, to an image having a coating apparatus for applying a lubricant that maintains the lubricity of an image bearing surface such as a photoconductor and an intermediate transfer body. The present invention relates to a forming apparatus.

  In an electrophotographic image forming apparatus, a toner image is formed on a photoreceptor by charging, exposure and development, and the formed toner image is transferred to a recording material and fixed to form an image on the recording material, or A toner image is formed on the photosensitive member by charging, exposure and development, the formed toner image is transferred to an intermediate transfer member, the toner image on the intermediate transfer member is transferred to a recording material, fixed, and an image is formed on the recording material. Is formed.

  As described above, the image forming process is repeated by transferring the toner image from the image carrier such as the photosensitive member or the intermediate transfer member to the transfer member such as the intermediate transfer member or the recording material, and cleaning the image carrier after the transfer. As a result, a large number of images are formed.

  A lubricant is applied to the surface of the image carrier for the purpose of improving and stabilizing the cleaning property in the cleaning step and the transfer property in the transfer step.

  In recent years, small-diameter toner has come to be used to form high-quality images. However, when small-diameter toner is used, the cleaning performance is likely to deteriorate, so that the application of a lubricant is difficult. It has become particularly important.

  Since the amount of lubricant on the image carrier also affects the transferability, it is necessary to form a uniform lubricant layer on the image carrier in order to stabilize the transfer.

  Patent Documents 1 to 4 propose that a uniform lubricant layer is formed on an image carrier such as a photoreceptor or an intermediate transfer member, and a high-quality image is stably formed.

Patent Document 1:
It has a new product detection means that detects that the photoconductor unit is new, and when the installation of a new photoconductor unit is detected, lubricant is applied, and the drive torque of the photoconductor is detected and detected. It has been proposed to determine the application time based on the drive torque.

Patent Document 2:
It has been proposed to detect the density of toner adhering to the outside of the image area of the photoreceptor and to control the lubricant application means based on the detection result.

Patent Document 3:
N / R is calculated assuming that the pixel amount of the written image is N and the rotation amount of the image carrier is R. When the image formation of a low image area where N / R is a certain value or less continues for a predetermined time or longer, the toner is It has been proposed to maintain the slidability of the surface of the image carrier by supplying it onto the image carrier.

Patent Document 4:
It has been proposed to have storage means for storing the amount of the written image, and to control the application of the lubricant to the image carrier based on the image amount stored in the storage means.
JP 2005-181742 A JP-A-8-254933 JP 2006-201464 A JP 2002-244486 A

  Generally, the toner contains a fine particle external additive such as silica for the purpose of ensuring fluidity.

  It is known that such fine particles act as an abrasive when the image carrier is rubbed with a cleaning member such as a rubber blade, and the lubricant on the image carrier is scraped off by toner containing the abrasive.

  Therefore, when the high density image, that is, the image formation in which a large amount of toner adheres to the image carrier continues, the amount of lubricant on the image carrier decreases.

  As a result, when high-density image formation continues, problems such as poor cleaning, progress of wear of the cleaning blade, and poor transfer (missing) occur.

  In Patent Documents 1 to 4, for such a problem, for example, an image amount is detected and a lubricant corresponding to the image amount is applied to prevent occurrence of defects such as defective cleaning.

  However, in the conventional techniques such as Patent Documents 2 to 5, since the toner amount of the entire image to be formed is detected, the detection accuracy of the toner amount is low, and problems such as defective cleaning due to lack of lubricant are sufficient. Could not be prevented.

  That is, in one page image, there are regions with a large amount of toner and regions with a small amount of toner, and even when the amount of toner forming the entire image is within a predetermined allowable range, it is locally high. There may be a toner amount area, which may cause a cleaning failure or the like.

  In addition, even when image formation on a small size recording paper continues for a long time, a shortage of lubricant occurs in a part of the image carrier, and the occurrence of the above problems is unavoidable.

  In Patent Document 1, the application of the lubricant is controlled based on the driving torque of the photoconductor. However, in the control based on the driving torque of the photoconductor, the amount of the lubricant on the photoconductor is accurately controlled. It is difficult to form a sufficiently stable image.

  The present invention aims to solve such problems.

The object is achieved by the following invention.
1.
An image carrier, a toner image forming device for forming a toner image on the image carrier, a transfer device for transferring a toner image on the image carrier to a transfer member, a cleaning device for cleaning the image carrier after transfer, and In an image forming apparatus that has a coating device that applies a lubricant to the image carrier, moves the image carrier, and performs image formation and lubricant application.
Based on the image amount detection means for detecting the image amount in the plurality of regions of the image carrier divided in the direction perpendicular to the moving direction of the image carrier, and the image amount in the plurality of regions detected by the image amount detection means. An image forming apparatus comprising control means for controlling application of the lubricant by the coating apparatus.
2.
2. The image according to 1, wherein the control unit controls application of the lubricant by the coating apparatus based on the detected unit time or the image amount per unit moving amount of the image carrier. Forming equipment.
3.
The control means operates the coating device when the image amount per unit time in at least one of the plurality of regions or a unit movement amount of the image carrier becomes a predetermined threshold value or more. The image forming apparatus according to 2 above.
4).
4. The image forming apparatus according to any one of 1 to 3, wherein the image amount detecting unit includes an image data counting unit that counts image data for forming a toner image.
5).
4. The image forming apparatus according to any one of 1 to 3, wherein the image amount detection unit includes a density detection unit that detects a density of a toner image and a density accumulation unit that accumulates the detected density of the density detection unit. Image forming apparatus.
6).
The control unit interrupts the job when the image amount detected by the image amount detection unit exceeds a predetermined threshold value, operates the application unit, and applies the lubricant onto the image carrier. 6. The image forming apparatus according to any one of 1 to 5, wherein application control is performed.
7).
When the image amount detected by the image amount detection unit exceeds a predetermined threshold value, the control unit waits for the end of the job being executed and operates the coating device to apply the image to the image carrier. 6. The image forming apparatus according to any one of 1 to 5, wherein a lubricant is applied.

  In the present invention, the image amount of the image formed on the image carrier is detected for each of a plurality of regions obtained by dividing the region of the image carrier, and the lubricant application device is provided based on the detection result of the image amount in the plurality of regions. Therefore, even when locally biased image formation continues on the image bearing member, it is possible to prevent defective cleaning, damage to the cleaning blade, defective transfer, etc. Thus, an image forming apparatus that forms stably can be realized.

  Hereinafter, the present invention will be described with reference to embodiments of the invention, but the present invention is not limited to the embodiments.

  FIG. 1 is a diagram showing an overall configuration of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus is a color image forming apparatus capable of forming a color image, and includes a Y image forming unit for forming a yellow toner image, an M image forming unit for forming a magenta toner image, and a C image forming for forming a cyan toner image. And a K image forming unit for forming a black toner image.

  Each of the Y, M, C, and K image forming units has a configuration described below, but in the drawing, only the Y image forming unit is denoted by the reference numerals for the components forming the image forming unit, and the others are omitted.

  In the figure, 10 is a photoconductor as an image carrier, 11 is a charging device comprising a scorotron band, 12 is an exposure device for writing an image by exposure using a laser diode, 13 is a developing device, and 14 is rubber. A cleaning device that cleans the surface of the photoconductor 10 with a cleaning blade, 15 is a blade for cleaning the photoconductor 10 that is a component of the cleaning device 14, 16 is a developing sleeve that is a component of the developing device 13, and 17 is a lubricant. 18 is a static elimination lamp as a static elimination means, 19 is a potential detection sensor as a potential detection means on the surface of the photoreceptor 10, and 20 is an intermediate transfer body. The cleaning device 14 including the coating device 17 will be described later.

  The image forming units Y, M, C, and K are configured by a gantry (not shown) on which the photoconductor 10, the charging device 11, the developing device 13, the cleaning device 14, and the like are placed, and along a guide rail (not shown). It can be inserted into and pulled out from the main body.

  The image forming units Y, M, C, and K are arranged in the order of Y, M, C, and K with respect to the traveling direction of the intermediate transfer body 20, and each has a primary transfer roller 25 and primary transfer. The roller 25 transfers the toner image of each color to the intermediate transfer member 20.

  The intermediate transfer member 20 is stretched around a driving roller 21, an earth roller 22, a tension roller 23, a charge-removing roller 27, and a driven roller 24. These rollers, the intermediate transfer member 20, the primary transfer roller 25, and a cleaning device as a cleaning unit. The belt unit 2 is composed of 28 or the like. The belt unit 2 is placed on a gantry (not shown) and can be inserted into and pulled out from the apparatus main body along a guide rail (not shown).

  The photosensitive member 10 is formed by forming a photosensitive layer such as a conductive layer, an a-Si layer, or an organic photosensitive member (OPC) on the outer periphery of a cylindrical metal base formed of, for example, an aluminum material, and the conductive layer is grounded. It rotates in the counterclockwise direction indicated by the arrow in the figure.

  An electrical signal corresponding to image data from the image reading device 80 or digital data from an external device such as a PC (personal computer) is input to the exposure device 12, converted into an optical signal, and the photoconductor 10 is image-exposed. .

  The developing device 13 has a developing sleeve 16 that is formed of a cylindrical nonmagnetic stainless steel or aluminum material that maintains a predetermined interval with respect to the peripheral surface of the photoconductor 10 and rotates in a direction opposite to the rotation direction of the photoconductor 10. ing.

The intermediate transfer member 20 travels by rotation of the drive roller 21 by a drive motor (not shown). The material of the intermediate transfer member 20 is an endless belt having a volume resistivity of 10 ⁶ to 10 ¹² Ω · cm, such as modified polyimide, thermosetting polyimide, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride, and nylon alloy. Two layers in which a conductive material is dispersed in an engineering plastic, and a fluorine coating having a thickness of 5 to 50 μm is preferably applied to the outside of a semiconductive film substrate having a thickness of 0.04 to 0.10 mm, preferably as a toner filming prevention layer. It is a seamless belt of the configuration. In addition to this, a semiconductive rubber belt having a thickness of 0.5 to 2.0 mm in which a conductive material is dispersed in silicon rubber, urethane rubber, or the like can also be used.

  The primary transfer roller 25 is applied with a DC voltage having a polarity opposite to that of the toner, presses the intermediate transfer member 20 against the photosensitive member 10 from the inside of the belt, and transfers the toner image formed on the photosensitive member 10 to the intermediate transfer member 20. To do.

  A secondary transfer roller 26 is a nip S formed by the earth roller 22 by pressing the earth roller 22 through the belt and the transfer material P by a not-shown pressure bonding and pressure release mechanism, and the intermediate transfer body 20. The upper toner image is transferred to the transfer material P. The secondary transfer roller 26 is made of a conductive solid rubber whose surface is covered with a coating layer, and a reverse polarity bias voltage is applied to the toner during transfer (or a voltage having the same polarity as the toner is applied to the ground roller 22). And the transfer roller 26 may be grounded).

  An AC voltage in which a DC voltage having the same or opposite polarity as that of the toner is superimposed is applied to the charge removal roller 27, and after the toner image is transferred to the transfer material P, the toner charge remaining on the intermediate transfer body 20 is weakened.

  A fixing device 4 includes a heating roller 41 and a pressure roller 42.

  The heating roller 41 has a cylindrical shape made of thin aluminum and has a halogen heater 47 and the like for heating from the inside to a predetermined temperature. The temperature is a contact (not shown) installed on the heating roller 41. It is detected and controlled by a temperature sensor.

  70 is a paper feed roller, 71 is a timing roller, and 72 is a paper feed tray unit, which can be pulled out from the apparatus body along the slide mechanism and pushed in. Reference numeral 73 denotes a conveyance roller. A discharge roller 81 discharges the fixed transfer material to a discharge tray 82.

  Next, the image forming process will be described with reference to FIG.

  Simultaneously with the start of image recording, the photosensitive member drive motor (not shown) is started to rotate the photosensitive member 10 of the image forming portion Y in the counterclockwise direction indicated by the arrow, and at the same time, the charging device 11 is charged to apply a potential to the photosensitive member 10. Is started.

  After the photoconductor 10 is applied with a potential, writing of an image corresponding to the Y image data is started by the exposure device 12, and an electrostatic latent image corresponding to the Y image of the original image is formed on the surface of the photoconductor 10. Is done.

  The electrostatic latent image is reversely developed in a non-contact state by the Y developing device 13, and a Y toner image is formed on the photoconductor 10 as the photoconductor 10 rotates.

  The Y toner image formed on the photoconductor 10 is primarily transferred onto the intermediate transfer body 20 by the action of the primary transfer roller 25.

  Thereafter, a lubricant is applied to the surface of the photoconductor 10 by the coating mechanism 17, and residual toner is cleaned by the blade 15 of the cleaning 14, and the next image forming cycle starts.

  Next, the exposure device 12 writes an image corresponding to an M (magenta) color signal, that is, M image data, and an electrostatic latent image corresponding to the M image of the original image is formed on the surface of the photoconductor 10. . The electrostatic latent image becomes an M toner image on the photosensitive member 10 by the M developing device 13, and is synchronized with the Y toner image on the intermediate transfer member 20 by the M primary transfer roller 25. The image is superimposed on the Y toner image.

  By a similar process, the Y and M superimposed toner images are synchronized, and the C (cyan) toner image is superimposed on the Y and M superimposed toner images by the C primary transfer roller 25. Is done. Next, the Y, M, and C superimposed toner images already formed are synchronized, and the K toner image is transferred to the K primary transfer roller 25 by the Y, M, and C superimposed toners. Overlaid on the image, a Y, M, C, and K superimposed color toner image is formed.

  The intermediate transfer member 20 carrying the color toner image is fed clockwise as indicated by the arrow, and the transfer material P is fed from the paper feed tray unit 72 by the paper feed roller 70, passes through the transport roller 73, and then the timing roller. It is conveyed to 71.

  After being temporarily stopped at the timing roller 71, the timing roller 71 is driven to synchronize with the superimposed toner image on the intermediate transfer member 20, and is fed to the nip portion S of the secondary transfer roller 26 to be intermediate transfer member 20. The upper toner image is secondarily transferred onto the transfer material P all at once.

  Thereafter, the intermediate transfer member 20 travels, the charge of the residual toner is weakened by the charge removing roller 27, the residual toner on the belt is cleaned by the blade 29 of the cleaning device 28 by the cleaning device 28, and the next image forming cycle starts.

  The toner scraped off is stored in the cleaning device 28, conveyed in the axial direction (in the drawing from the paper surface to the paper back direction) by rotation of a conveyance screw (not shown), and stored in a storage box via a waste pipe (not shown). Accumulated.

  The transfer material P onto which the superimposed toner image has been transferred is sent to the fixing device 4, and is nipped, pressed and fixed at the nip portion T between the heating roller 41 and the pressure roller 42. The transfer material P on which the toner image is fixed is conveyed to a paper discharge tray 82 by a paper discharge roller 81.

  Next, application of the lubricant will be described.

  The lubricant is applied to an image carrier such as a photoreceptor or an intermediate transfer member, and maintains the surface resistance of the image carrier at a predetermined value. The lubricant includes stearic acid such as zinc stearate and calcium stearate. Metal salts are used.

  A solid-state lubricant is installed in the image forming apparatus, and in the illustrated example, it is applied to the photoconductor 10 as an image carrier little by little with a brush or the like.

  By forming a lubricant film on the surface of the photoconductor 10, the surface frictional resistance of the photoconductor 10 is reduced, and the cleaning performance and transfer performance are improved.

  FIG. 2 shows the structure of the lubricant application device, and each of the image forming portions Y, M, C, and K in FIG. 1 has the structure shown in FIG.

  In FIG. 2, in order to apply the lubricant to the surface of the photoreceptor, the lubricant 142 is brought into contact with the brush 171 at a position away from the contact portion between the brush 171 formed in a roller shape and the photoreceptor 10. Scrapes off the lubricant, and the brush 171 to which the lubricant has adhered is brought into contact with the photosensitive member 10.

  In the cleaning device 14, the blade 15 scrapes off the transfer residual toner on the photoreceptor 10, and is stored in the cleaning device 14, and is stored in a storage box by a transport screw 146 through a waste pipe (not shown).

  The lubricant application device 17 includes a brush 171 made of conductive nylon or conductive acrylic fiber, a lubricant 142 made of zinc stearate (ZnSt) or calcium stearate (CaSt) equivalent to pencil hardness HB, and a support for the lubricant 142. A guide 145, a pusher base 174 that slides in the support guide 145, and a pressure spring 173 that causes the lubricant 142 to contact the brush 171 with a predetermined pressure via the pusher base 174.

  In the embodiment, the rotation directions of the brush 171 and the photosensitive member 10 are the same, but they may be opposite to each other. The brush 171 is rotationally driven by a variable-speed motor M.

  The lubricant 142 contacts the brush 171 with a predetermined pressure by the pressure spring 173, and the lubricant is applied to the surface of the photoconductor 10.

  As shown in the figure, the brush 171 is arranged on the upstream side of the blade 15 with respect to the rotation direction of the photoconductor 10, and the blade 15 slides on the surface of the photoconductor 10 coated with a lubricant.

  Therefore, since the blade 15 cleans the photosensitive member 10 having a reduced frictional resistance, the cleaning performance is improved. Further, the lubricant 142 is pushed up as it is gradually consumed, but since the pressure in the predetermined range is maintained with the brush, the lubricant is uniformly and stably applied to the photoconductor 10. The

  The lubricant 142 is applied to the surface of the photoconductor 10 to which the residual toner has adhered, and the residual toner and the lubricant are scraped off by the blade 15, but a part of the lubricant 142 remains on the surface of the photoconductor 10, and the next image Enter into formation.

  The amount of lubricant on the photoconductor 10 is gradually reduced by being scraped off by the blade 15 or the like when the photoconductor 10 rotates during image formation, but remains on the photoconductor 10 over a plurality of rotations.

  The amount of lubricant on the photoconductor 10 is affected by the amount of toner on the photoconductor 10.

  That is, it is considered that the lubricant on the photoconductor 10 is scraped off by the toner polishing effect.

  The toner contains an external additive such as silica. When the blade 15 scrapes off the toner from the photoreceptor 10, the external additive acts as an abrasive, and the blade 15 is removed from the photoreceptor 10. Remove the lubricant.

  By such an action, the lubricant is removed from the photoconductor 10 as the amount of toner on the photoconductor 10 increases, that is, as the image formation with a high printing rate is performed.

  FIG. 3 shows the amount of lubricant on the photoconductor 10 in a solid image, that is, an image region with a large amount of toner, a white image, that is, an image region with a small amount of toner, and a region outside the image region (region without toner adhesion). The results are shown. The measured values are based on ESCA (Electron Spectroscopy for Chemical Analysis).

  Also, in the figure, Zn is an experimental example in which zinc stearate is used and Ca is calcium stearate as a lubricant, and photosensitivity at the stage where 5 kC (50000 sheets) of a copy of an original having coverage of 0% and 100% was performed. It is the result of conducting an experiment of inspecting the body surface twice.

  FIG. 4 shows the contact angles of the white and solid portions of the photoreceptor surface.

  The contact angle substantially corresponds to the amount of lubricant, and the smaller the contact angle, the smaller the amount of lubricant.

  As is apparent from FIGS. 3 and 4, the amount of lubricant in the solid portion is small, the amount of lubricant changes depending on the amount of toner, and the amount of lubricant on the photoreceptor decreases as the amount of toner increases. It is clear that it is remarkable.

  In copying or printing, the surface of the photoreceptor 10 is not used uniformly but is used in a biased manner.

  As shown in FIG. 5, when the photosensitive member 10 is divided into a plurality of regions A1, A2,... An in the main scanning direction, that is, the direction X perpendicular to the moving direction Y of the photosensitive member 10, the regions A1, A2,. A toner image is not formed evenly on An, but an image with a different toner amount is formed for each region, and the amount of toner to be cleaned is different.

  Therefore, as can be seen from the experimental results shown in FIGS. 3 and 4, the amount of lubricant is different in the regions A1, A2,.

  In the present embodiment, the region on the photoconductor 10 is divided into a plurality of regions A1, A2,... An in the main scanning direction X, the image amount per unit time in each region is calculated, and the image amount is the largest. The lubricant application device is controlled based on the image amount in the region.

  The image amount is the amount of toner forming a toner image on the image carrier.

  In the present invention, the image amount is detected. As the image amount detection means, a means for accumulating image data for forming a toner image or a density of a toner image formed on an image carrier is detected. A means for accumulating the detected density can be employed.

  As a result, poor cleaning due to lack of lubricant, abrasion of the cleaning blade, transfer omission, etc. were prevented very well.

  Hereinafter, control of lubricant application based on such an image amount will be described.

  FIG. 6 is a block diagram of a control system that performs lubricant application control, in which 100 is a control means, 101 is an image processing unit, and 102a to 102n are images that form images to be printed in areas A1 to An in FIG. A pixel counter serving as an image amount detection unit that counts pixel values of data, 103 a toner image forming apparatus that forms a toner image on the photoconductor 10, and M a motor M in FIG. 2, that is, a motor that rotationally drives the brush 171 It is. The toner image forming apparatus 103 includes the charging device 11, the exposure device 12, and the developing device 13 in FIG.

  FIG. 7 is a flowchart of the lubricant application control performed by the control means 100 in FIG.

  In the image forming process, as described above, the motor M rotates the brush 171 to apply the lubricant to the photoconductor 10.

  The control unit 100 controls the lubricant application shown in FIG. 7 in addition to the lubricant application in the image forming process.

  In FIG. 7, step S1 is a start step of image formation. In the start of image formation, the control unit 100 operates the toner image forming apparatus 103 to form a toner image on the photoreceptor 10.

  Simultaneously with the start of image formation, the pixel counters 102a to 102n count pixel values corresponding to images formed in the areas A1 to An in FIG.

  The count in step S2 is a count of image data output from the image processing unit 101, that is, image data that drives the exposure apparatus 12. In the formation of a binary image, the count is the number of pixels, but a multi-value image is formed. Then, it is a count of the pixel value of each pixel.

  In step S3, the travel distance of the photoconductor 10 is measured. The measurement start in step S3 starts simultaneously with the image data count in step S2.

  In step S4, coverages C1 to Cn in the respective areas A1 to An are calculated.

This coverage is represented by C1 = {G1 / (W1 × R)} × 100, C2 = {G2 / (W2 × R)} × 100... Cn = {Gn / (Wn × R)} × 100. It is a ratio.

  W1 to Wn are widths in the main scanning direction X of the regions A1 to An, R is a unit travel distance of the photoconductor 10, and G1 to Gn are cumulative values of pixel values in the regions A1 to An in the unit travel distance.

  As the unit distance, for example, the total length of 5000 A4 size sheets is used.

  In step S5, it is determined whether or not C1 to Cn is equal to or greater than the threshold value Th. If all of C1 to Cn are smaller than the threshold value Th, image formation is continued (step S6).

  When any one of C1 to Cn is equal to or greater than the threshold value Th, it is determined that the amount of lubricant in the specific portion on the photoconductor 10 is insufficient, and image formation is interrupted (step S7).

  Following the interruption of image formation, the motor M2 is operated and the photosensitive member 10 is rotated to apply a lubricant to the photosensitive member 10 (step 8).

  The lubricant application in step 8 is executed for a predetermined time, and then image formation is resumed in step S9.

  Although image formation is interrupted in step S7, image formation may be continued without intermediate processing, and lubricant application may be performed after the end of the job.

  FIG. 8 is a flowchart of such control.

  In the control of FIG. 8, steps S5 and S6 are the same as those in FIG.

  In the case of Yes in step S5 in FIG. 7, the process proceeds to step S10 in FIG. 8, and image formation is continued.

  When image formation is completed (Yes in step S11), a lubricant application operation is performed (step S12), and the process ends after application of the lubricant.

  The lubricant application to the photosensitive member 10 has been described above. However, in the control of applying the lubricant to the intermediate transfer member 20 and applying the lubricant to the intermediate transfer member, the above-described control, that is, a region divided into a plurality of regions. It is also possible to detect the image amount every time and perform lubricant application control corresponding to the detected image amount.

  In the color image forming apparatus shown in FIG. 1, a plurality of toner images are formed on the intermediate transfer body 20. When the plurality of toner images are formed in this way, the image amount is determined by each of the image forming units Y and M. , C and K, the total amount of toner constituting the formed image in the toner image forming apparatus is calculated as the image amount.

  As the image amount detecting means for detecting the image amount, one that directly detects the toner image formed on the image carrier can be used.

  That is, it is possible to provide a density sensor for detecting the image density of the toner image on the image carrier or transfer body, and to detect the image amount by accumulating the image density detected by the density sensor.

1 is a diagram illustrating an example of an overall configuration of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows the structure of a lubricant coating device. It is a graph which shows the measurement result of the lubricant amount on a photoconductor. It is a figure which shows the contact angle of the photoreceptor surface of a white background part and a solid part. It is a figure which shows the several area | region on a photoconductor. It is a block diagram of the control system which performs lubricant application control. It is an example of the flowchart of lubricant application control. It is another example of the flowchart of lubricant application control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photoconductor 11 Charging device 14 Cleaning device 142 Lubricant 15 Blade 17 Application mechanism 171 Brush 20 Intermediate transfer member

Claims (7)

An image carrier, a toner image forming device for forming a toner image on the image carrier, a transfer device for transferring a toner image on the image carrier to a transfer member, a cleaning device for cleaning the image carrier after transfer, and In an image forming apparatus that has a coating device that applies a lubricant to the image carrier, moves the image carrier, and performs image formation and lubricant application.
Based on the image amount detecting means for detecting the image amount in the plurality of regions of the image carrier divided in the direction perpendicular to the moving direction of the image carrier, and the image amount in the plurality of regions detected by the image amount detecting means. An image forming apparatus comprising control means for controlling application of the lubricant by the coating apparatus. The said control means controls application | coating of the lubricant by the said application | coating apparatus based on the detected unit time or the said image amount per unit moving amount of the said image carrier. Image forming apparatus. The control means operates the coating device when the image amount per unit time in at least one of the plurality of regions or a unit movement amount of the image carrier becomes a predetermined threshold value or more. The image forming apparatus according to claim 2. The image forming apparatus according to claim 1, wherein the image amount detection unit includes an image data counting unit that counts image data for forming a toner image. 4. The image amount detecting unit according to claim 1, further comprising: a density detecting unit that detects a density of the toner image; and a density accumulating unit that accumulates the detected density of the density detecting unit. Image forming apparatus. The control unit interrupts the job when the image amount detected by the image amount detection unit exceeds a predetermined threshold value, operates the application unit, and applies the lubricant onto the image carrier. 6. The image forming apparatus according to claim 1, wherein application control is performed. When the image amount detected by the image amount detection unit exceeds a predetermined threshold value, the control unit waits for the end of the job being executed and operates the coating device to apply the image to the image carrier. The image forming apparatus according to claim 1, wherein a lubricant is applied.

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