JP2013167808A - Cleaning device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device which optimizes a toner amount to be supplied to a cleaning blade to reduce toner consumption, and improves robustness of image carrier cleaning.SOLUTION: A cleaning device 100 is used for an image forming apparatus including an image carrier 6 for carrying a toner image, and image forming means for forming the toner image on the image carrier. The cleaning device 100 comprises: a cleaning blade 101 for pressure contacting with the image carrier to remove toner on the image carrier; toner supply means 102, 103 for supplying the toner to the cleaning blade; switching means for switching a pressure contact with the image carrier by the cleaning blade, and a release thereof; detecting means 111 for detecting a toner amount on the image carrier left without being removed due to the release of the pressure contact with the image carrier; and control means for controlling a toner amount of the toner image formed on the image carrier by the image forming means on the basis of the detected toner amount.

Description

  The present invention relates to a cleaning device and an image forming apparatus.

  A toner image is formed on the photoconductor by charging, exposure, and development, and the toner image is directly transferred to a sheet of paper, or the toner images on a plurality of photoconductors are primary-transferred to an intermediate transfer member and then transferred onto the intermediate transfer member. In the image forming apparatus configured to secondarily transfer the toner image to the paper, a cleaning blade made of urethane rubber or the like is provided on the image carrier to remove the residual toner on the photoconductor or intermediate transfer body after the transfer. A blade cleaning method for cleaning by pressure contact is known.

  In the blade cleaning method, friction between the cleaning blade and the image carrier may cause the cleaning blade to sag or damage the edge, or cause toner filming. For this reason, a toner band made of a belt-like toner is formed on the image carrier, and the toner in the toner band functions as a lubricant by arriving at the edge of the cleaning blade. The friction coefficient between them has been lowered. However, a toner band is formed each time an image is formed, and the toner used as a lubricant is discarded, so that the amount of toner consumption increases.

  Techniques for preventing the cleaning blade from curling and wearing and suppressing toner consumption include the following. That is, the toner guide member that contacts the image carrier upstream of the pressure contact position by the cleaning blade with respect to the rotation direction of the image carrier, the toner discharge regulating member that contacts the toner guide member, and the toner storage space by the image carrier. Form. The toner removed from the image carrier by the blade cleaning method is stored in the storage space, and the toner is supplied to the cleaning blade by bringing the image carrier into contact with the toner in the storage space and attaching the toner. Some devices detect the amount of toner in a storage space and control the formation of a toner band based on the detected amount (Patent Document 1).

JP-A-2005-275219

  However, it becomes difficult for the toner to adhere to the image carrier due to the deterioration of the toner or the change in the surface state of the image carrier. Therefore, in the above prior art, even if the amount of toner stored in the storage space is sufficient, the toner does not sufficiently adhere to the image carrier due to toner deterioration or the like, which is necessary to prevent the cleaning blade from curling. There may be a situation in which a large amount of toner is not supplied to the cleaning blade. Further, if new toner is frequently supplied in order to prevent such a state, the amount of toner consumption increases.

  The present invention has been made to solve such problems. In other words, the pressure contact of the image carrier with the cleaning blade can be released, so that the amount of toner remaining on the image carrier is detected, and the amount of toner in the toner band formed on the image carrier is determined based on the detected amount. Control. Accordingly, an object of the present invention is to optimize the amount of toner supplied as a lubricant to reduce toner consumption and improve the robustness of image carrier cleaning.

  The above-described problems of the present invention are solved by the following means.

  A cleaning device used in an image forming apparatus having an image carrier that carries a toner image and an image forming unit that forms the toner image on the image carrier, and is pressed against the rotating image carrier And switching for switching between the cleaning blade for removing the toner remaining on the image carrier, the toner supply means for supplying toner to the cleaning blade, and the pressure contact of the image carrier by the cleaning blade and the release of the pressure contact And detecting the amount of toner remaining on the image carrier remaining without being removed by the cleaning blade by releasing the pressure contact with the image carrier that is rotated by the cleaning blade by the switching means. And the amount of toner of the toner image formed on the image carrier by the image forming unit is detected by the detecting unit. A cleaning device and a control means for controlling, based on the amount of toner.

  Further, the above-described problems of the present invention are solved by the following means.

  An image carrier that carries a toner image, an image forming unit that forms the toner image on the image carrier, and a cleaning that presses against the rotating image carrier to remove toner remaining on the image carrier. A blade, toner supply means for supplying toner to the cleaning blade, switching means for switching between pressing and releasing of the image carrier by the cleaning blade, and rotation by the cleaning blade by the switching means. Detection means for detecting the amount of toner on the image carrier remaining without being removed by the cleaning blade by releasing the pressure contact with the image carrier, and the image forming means formed on the image carrier Control means for controlling the amount of toner in the toner image to be detected based on the amount of toner detected by the detection means. Apparatus.

  By making it possible to release the pressure contact of the image carrier with the cleaning blade, the toner remaining on the image carrier is detected, and the amount of toner in the toner band formed on the image carrier is controlled based on the detected amount. As a result, the amount of toner supplied as the lubricant can be optimized to reduce the toner consumption, and the robustness of the image carrier cleaning can be improved.

It is explanatory drawing which shows the image forming apparatus which concerns on embodiment of this invention. 1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. It is principal part sectional drawing of the cleaning apparatus which concerns on this embodiment of this invention. FIG. 6 is an explanatory diagram illustrating an operation of the cleaning device according to the embodiment of the present invention when toner is left on the intermediate transfer belt to detect the amount of toner. 6 is a graph showing the relationship between the toner adhesion amount on the intermediate transfer belt and the output voltage of the IDC sensor. It is a figure which shows the flowchart of operation | movement of the cleaning apparatus which concerns on embodiment of this invention. FIG. 6 is a diagram showing the amount of toner in the width direction of an intermediate transfer belt when a cleaning device according to an embodiment of the present invention is implemented in comparison with a conventional example.

  Hereinafter, a cleaning device and an image forming apparatus having the same according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram illustrating an image forming apparatus according to the present embodiment.

  The image forming apparatus A is called a tandem type color image forming apparatus, and performs color image formation by four sets of image forming units 10C, 10M, 10Y, and 10K.

  The document placed on the document table is scanned and exposed by the optical system of the inspection exposure device of the image reading device SC, read into the line image sensor, and the photoelectrically converted image information signal is supplied to an image processing unit (not shown). ), Analog processing, A / D conversion, shading correction, image compression processing, and the like are performed, and then input to the optical writing unit of the image forming unit.

  The four image forming units include an image forming unit 10Y that forms a yellow (Y) image, an image forming unit 10M that forms a magenta (M) image, and an image forming unit that forms a cyan (C) image. 10C is an image forming unit 10K that forms a black (K) color image, and is denoted by symbols Y, M, C, and K representing colors formed after the common symbol 10, respectively.

  The image forming unit 10Y includes a photosensitive drum 1Y and a charging unit 2Y, an optical writing unit 3Y, a developing device 4Y, and a drum cleaner 5Y arranged around the photosensitive drum 1Y.

  Similarly, the image forming unit 10M includes a charging unit 2M, an optical writing unit 3M, a developing device 4M, and a drum cleaner 5M disposed around the photosensitive drum 1M, and the image forming unit 10C includes a periphery of the photosensitive drum 1C. The image forming unit 10K includes a charging unit 2K, an optical writing unit 3K, a developing unit 4C, and a developing unit 4C and a drum cleaner 5C. The apparatus includes a device 4K and a drum cleaner 5K.

  Photosensitive drums 1Y, 1M, 1C, and 1K in the image forming units 10Y, 10M, 10C, and 10K, charging units 2Y, 2M, 2C, and 2K, optical writing units 3Y, 3M, 3C, and 3K, a developing device 4Y, 4M, 4C, and 4K and drum cleaners 5Y, 5M, 5C, and 5K have the same content. In the following description, symbols Y, M, C, and K are not used unless particularly distinguished.

  The image forming unit 10 charges the outer peripheral surface of the photosensitive drum 1 by the charging unit 2, then writes an image information signal to the photosensitive drum 1 by the optical writing unit 3, and the image information signal to the photosensitive drum 1. To form a latent image. The latent image is developed by the developing device 4 to form a visible toner image on the photosensitive drum 1.

  In each of the image forming units 10Y, 10M, 10C, and 10K, the photosensitive drums 1Y, 1M, 1C, and 1K are respectively yellow (Y), magenta (M), cyan (C), and black (K). Images are formed.

  The intermediate transfer belt 6 is wound around a plurality of rollers and supported so as to be able to run. The intermediate transfer belt 6 runs by rotating in the direction indicated by the arrow in FIG. 1 (the clockwise direction on the paper surface) under the control of the control unit 90. In the following description, the direction in which the intermediate transfer belt 6 rotates when an image is formed in the image forming apparatus A is referred to as the “rotation direction” of the intermediate transfer belt 6.

  The toner images of the respective colors formed by the image forming units 10Y, 10M, 10C, and 10K are sequentially transferred onto the traveling intermediate transfer belt 6 by the primary transfer units 7Y, 7M, 7C, and 7K to be Y (yellow), M ( A color image is formed by toner in which the respective color layers of magenta), C (cyan), and K (black) are superimposed.

  The paper transport unit 20 transports the paper S. The paper S is accommodated in the paper feed trays 291, 292, 293, fed by the first paper feeding unit 21, conveyed to the secondary transfer unit 7 A through the registration roller 22, and the intermediate transfer belt on the paper S. 6 is transferred. The secondary transfer unit 7A is an example of a transfer unit, and transfers the toner image onto the paper S and transports the paper S.

  A cleaning device 100 according to this embodiment is provided on the downstream side of the secondary transfer portion 7 </ b> A with respect to the rotation direction of the intermediate transfer belt 6. The cleaning device 100 removes the toner remaining on the intermediate transfer belt 6 after the toner image is transferred onto the paper S in the secondary transfer portion 7A by bringing the cleaning blade into pressure contact with the rotating intermediate transfer belt 6. The details of the cleaning device will be described later.

  The sheet S on which the toner image is transferred in the secondary transfer unit 7A is fixed with the toner image on the sheet S by applying heat and pressure by the fixing device 40, and passes through the fixing conveyance roller 23 and the sheet discharge roller 25. It is discharged out of the device.

  The fixing device 40 fixes the toner image transferred onto the paper S by the secondary transfer unit 7A to the paper S, and conveys the paper S.

  The image forming apparatus A is provided with a paper reversing unit 24. The fixed paper can be guided from the fixing conveyance roller 23 to the paper reversing unit 24 so that the front and back are reversed and discharged, or an image can be formed on both sides of the paper. It is said.

  The size and number of sheets S can be set when performing image formation from the operation display unit 80 installed at the upper part of the main body of the image forming apparatus A.

  The operation of each part for image formation and the operation of each part for conveying the paper S are controlled by the control unit 90.

  The control unit 90 performs control of the above units and various arithmetic processes. In addition, the control unit 90 performs rasterization processing of image data received from an external computer, and creates bitmap data for image formation.

  The intermediate transfer belt 6 constitutes an image carrier, and the image forming units 10Y, 10M, 10C, and 10K constitute image forming means. The storage sheet 103 constitutes a contact member, and the rotating roller 102 and the storage sheet 103 constitute toner supply means. The control unit 90 constitutes switching means, control means, and reverse rotation control means. The sensor 111 and the control unit 90 constitute detection means.

  FIG. 2 is a block diagram illustrating a configuration of the image forming apparatus.

  As illustrated in FIG. 2, the image forming apparatus A includes a CPU 200, a RAM 201, a ROM 202, an HDD 203, an external interface 204, an operation unit 205, a display unit 207, an image control unit 208, a reading unit 209, a printing unit 209, and a cleaning unit 210. Is provided. These components are connected to each other via a bus 211 for exchanging signals.

  The CPU 200 performs control of each component described above and various arithmetic processes according to a program. That is, the CPU 200 performs overall control related to various processes, printing, storage, and cleaning while cooperating with each component constituting the image forming apparatus A.

  The RAM 201 temporarily stores various data received via the reading unit 208 or the external interface 204 via the network. Various data including image data stored in the RAM 201 is processed by the CPU 200 and transmitted to the HDD 203 and the image control unit 207 as necessary.

  The ROM 202 stores various programs and various data.

  The HDD 203 is an apparatus for storing various programs including a program for the CPU 200 to control each component of the image forming apparatus A, various data such as print job data, and rasterized image data. Programs and data stored in the HDD 203 are read by the CPU 200 as necessary, and executed or processed on the RAM 201.

  The external interface 204 is an interface for performing communication between the image forming apparatus A and an external device. The external interface 204 is a network interface based on a standard such as Ethernet (registered trademark), token ring, or FDDI, or a serial interface such as USB or IEEE1394. A parallel interface such as SCSI, IEEE1284, various local connection interfaces such as a wireless communication interface such as Bluetooth (registered trademark), IEEE802.11, HomeRF, and IrDA, a telephone line interface for connecting to a telephone line, and the like are used.

  The operation unit 205 has various fixed settings such as a touch panel for performing various settings, a numeric keypad for setting the number of copies, a start key for instructing start of operation, a stop key for instructing stop of operation, a reset key for initializing various setting conditions, and the like. It consists of keys.

  A display unit 206 displays various information or a touch panel for inputting various settings, a numeric keypad for setting the number of copies, a start key for instructing start of operation, a stop key for instructing stop of operation, and various setting conditions in the initial stage. It consists of various fixed keys such as reset keys, display lamps and the like. Note that regarding the overlapping functions of the operation unit 205 and the display unit 206, either the operation unit 205 or the display unit 206 may have this function.

  The image control unit 207 performs rasterization processing and layout processing of image data included in the print job.

  The reading unit 208 applies light to a document set at a predetermined reading position on the document table with a light source such as a fluorescent lamp, and photoelectrically converts the reflected light with an imaging device such as a CCD (Charge Coupled Device) image sensor. Image data (bitmap data) is generated from the electrical signal.

  The printing unit 209 prints an image based on the image data on a sheet through the steps of charging, exposure, development, transfer, and fixing by an electrophotographic method.

  In the cleaning unit 210, the cleaning blade is in pressure contact with the intermediate transfer belt 6 that rotates and removes toner remaining on the intermediate transfer belt 6. The cleaning unit 210 switches between the press contact with the intermediate transfer belt 6 by the cleaning blade and the release of the press contact. The cleaning unit 210 detects the amount of toner remaining without being removed from the intermediate transfer belt 6 by releasing the pressure contact with the intermediate transfer belt 6 by the cleaning blade, and based on the detected amount of toner. The amount of toner included in the toner band (toner image) formed on the intermediate transfer belt 6 is adjusted. The toner band is supplied to the cleaning blade via the intermediate transfer belt 6, and is formed to prevent the cleaning blade from curling and wearing, and toner filming.

  FIG. 3 is a cross-sectional view of a main part of the cleaning device according to the present embodiment.

  The cleaning device 100 includes a cleaning blade 101, a rotating roller 102, a storage sheet 103, a casing 104, a support shaft 105, a blade holder 106, a toner discharge unit 107, a toner receiving sheet 108, a pressing spring 109, a middle plate 110, and a sensor 111. It is configured. Note that the control unit 90 configured by the CPU 200, the RAM 201, the ROM 202, and the HDD 203 and controlling each of the above components is also a component of the cleaning device 100, but is not illustrated in FIG.

  The cleaning device 100 is provided on the downstream side of the secondary transfer portion 7A with respect to the rotation direction of the intermediate transfer belt 6 (the direction of the straight arrow in FIG. 2).

  A support shaft 105 is provided in the casing 104 in which each component of the cleaning device 100 is accommodated, and the support shaft 105 is rotatably supported by the casing 104.

  The cleaning blade 101 is fixed to one end of a blade holder 106 attached to the support shaft 105. The support shaft 105 can be rotated by a motor, for example, so that the cleaning blade 101 can be rotated about the support shaft 105 together with the blade holder 106 attached to the support shaft 105. The rotation angle of the support shaft 105 is switched by the motor to switch between the state where the intermediate transfer belt 6 is pressed by the cleaning blade 101 and the state where the pressure contact of the intermediate transfer belt 6 by the cleaning blade 101 is released. Can do.

  The pressure contact with the intermediate transfer belt 6 by the cleaning blade 101 is performed by pressing the intermediate transfer belt 6 at the portion carried by the driving roller 61 in a state where the tip of the cleaning blade 101 faces in the direction opposite to the rotation direction of the intermediate transfer belt 6. To do.

  The press contact of the intermediate transfer belt 6 with the cleaning blade 101 may be performed as follows. That is, the rotation control by the motor with respect to the support shaft 105 is removed. The cleaning blade 101 is urged counterclockwise about the support shaft 105 by a pressing spring 109 provided between the intermediate plate 110 fixed to the casing 104 and the other end of the blade holder 106. The cleaning blade 101 may be brought into pressure contact with the intermediate transfer belt 6.

  The cleaning blade 101 can be made of an elastic body such as urethane rubber.

  In the following description, the position P on the intermediate transfer belt 6 where the cleaning blade 101 presses the intermediate transfer belt 6 is referred to as a “pressure contact position P”.

  The rotation roller 102 is in contact with the intermediate transfer belt 6 on the upstream side of the pressure contact position P on the intermediate transfer belt 6 with respect to the rotation direction of the intermediate transfer belt 6. The rotary roller 102 has a columnar shape having the same height as the width of the intermediate transfer belt 6 and can be constituted by a roller of NBR (Nitrile Butadiene Rubber) and a stainless steel core.

  The rotating roller 102 rotates in the same direction as the intermediate transfer belt 6 (the direction of the counterclockwise curved arrow in FIG. 3) at the contact position with the intermediate transfer belt 6. In addition, the peripheral speed of the rotating roller 102 is higher than the peripheral speed of the intermediate transfer belt 6.

  One end of the storage sheet 103 is fixed to the intermediate plate 110, and the other end is in contact with the rotating roller 102 at a position opposite to the contact position between the rotating roller 102 and the intermediate transfer belt 6. The storage sheet 103 can be configured using, for example, a PET (PolyEthylene Terephthalate) material.

  The toner discharge unit 107 discharges the toner accumulated at the bottom of the casing 104 to the outside of the casing 104. The toner discharge unit 107 can be configured by a screw having a suction function.

  The sensor 111 is provided downstream of the pressure contact position P on the intermediate transfer belt 6 with respect to the rotation direction of the intermediate transfer belt 6 and detects the amount of toner adhering to the intermediate transfer belt 6. The sensor 111 can be configured by an IDC (Image Density Control) sensor.

  The cleaning device operates as follows by having the above configuration.

  The cleaning blade 101 is pressed against the rotating intermediate transfer belt 6 to remove the toner remaining on the intermediate transfer belt 6 after the toner image is transferred to the paper S in the secondary transfer portion 7A. The belt 6 is cleaned. The intermediate transfer belt 6 is rotated by a driving roller 61 that rotates by itself (the direction of rotation is a clockwise curved arrow in FIG. 3), a belt tension roller 62 and a supporting roller 63 that do not rotate by itself, and other rollers. Rotation travels by being supported or supported.

  The intermediate transfer belt 6, the rotating roller 102, and the storage sheet 103 form a storage space 112 in which toner can be stored. In the storage space 112, the toner on the intermediate transfer belt 6 removed by the cleaning blade 101 is stored. Since the storage space 112 has the same width as the width of the intermediate transfer belt 6, the toner stored in the entire width direction of the intermediate transfer belt 6 contacts the intermediate transfer belt 6 that forms the storage space 112. Therefore, the toner can be attached to the entire storage space 112 in the width direction of the intermediate transfer belt 6. The toner adhered on the intermediate transfer belt 6 is supplied to the cleaning blade 101 that is in pressure contact with the intermediate transfer belt 6 as the intermediate transfer belt 6 rotates.

  Note that by rotating the rotating roller 102 faster than the peripheral speed of the intermediate transfer belt 6, a part of the toner stored on the surface of the rotating roller 102 that moves as the rotating roller 102 rotates is provided on the storage sheet. It can be discharged to the bottom of the casing 104 from a vertical linear cut. As a result, the amount of toner stored in the storage space 112 can be kept substantially constant.

  When the pressure contact of the intermediate transfer belt 6 by the cleaning blade 101 is released, the toner on the intermediate transfer belt 6 is not removed by the cleaning blade 101. Therefore, it is possible to move the toner on the intermediate transfer belt 6 to a region where the toner sensor 111 can be detected while the toner remains on the intermediate transfer belt 6.

  FIG. 4 is an explanatory view showing the operation of the cleaning device when the amount of toner is detected by leaving the toner on the intermediate transfer belt. 4A shows a state in which the pressure contact with the intermediate transfer belt by the cleaning blade is released. FIG. 4B shows a state in which the intermediate transfer belt is rotated while the pressure contact with the intermediate transfer belt by the cleaning blade is released.

  As shown in FIG. 4A, by rotating the support shaft 105 in the clockwise direction, the pressure contact with the intermediate transfer belt 6 by the cleaning blade 101 is released. Further, as shown in FIG. 4B, the intermediate transfer belt 6 is rotated in a state in which the pressure contact with the intermediate transfer belt 6 by the cleaning blade 101 is released. As a result, the toner 112 a on the intermediate transfer belt 6 can be moved to the detectable area directly below the toner sensor 111 while the toner 112 a adhered to the intermediate transfer belt 6 in the storage space 112 remains.

  FIG. 5 is a graph showing the relationship between the toner adhesion amount on the intermediate transfer belt and the output voltage of the IDC sensor.

  The relationship between the toner adhesion amount on the intermediate transfer belt 6 and the output voltage of the IDC sensor is obtained in advance by actual measurement, and the amount of toner on the intermediate transfer belt 6 is determined by comparing the output of the sensor 111 with the relationship. Can be detected. Here, the amount of toner means the weight of toner per unit area.

  A plurality of sensors 111 are provided in the width direction of the intermediate transfer belt 6 (in the direction perpendicular to the rotation direction of the intermediate transfer belt 6 on the intermediate transfer belt 6), so that toner at a plurality of positions in the width direction of the intermediate transfer belt 6 is provided. Can be detected. The sensor 111 may be configured to detect the amount of toner at a plurality of locations in the width direction of the intermediate transfer belt 6 by being scanned in the width direction of the intermediate transfer belt 6. Further, the sensor 111 may be configured by a line sensor so as to simultaneously detect the amount of toner at a plurality of locations in the width direction of the intermediate transfer belt 6.

  A toner band is formed on the intermediate transfer belt 6 based on the amount of toner detected by the sensor 111. When the intermediate transfer belt 6 is brought into the pressure contact state by the cleaning blade 101 again, new toner constituting the toner band is removed by the cleaning blade 101 and stored in the storage space 112. By storing the new toner in the storage space 112, the adhesion of the toner to the intermediate transfer belt 6 that has decreased due to the deterioration of the toner is improved, and the amount of toner that adheres to the intermediate transfer belt 6 in the storage space 112 is increased. be able to. Thus, the amount of toner necessary for preventing the cleaning blade 101 from curling or edge damage and preventing toner filming can be supplied to the cleaning blade 101 via the intermediate transfer belt 6.

  Therefore, according to the present embodiment, the amount of toner supplied to the cleaning blade 101 as a lubricant can be optimized to reduce the toner consumption. In addition, since the variation in the amount of toner adhering to the cleaning blade 101 that may be caused by a change in environmental conditions is suppressed, the robustness of the cleaning of the intermediate transfer belt 6 can be improved.

  Further, the sensor 111 detects the amount of toner at a plurality of locations in the width direction of the intermediate transfer belt 6, and the amount of toner in the toner band formed on the extension line in the rotation direction of the intermediate transfer belt 6 from each location is determined at each location. Each can be controlled based on the amount of toner. As a result, the toner adhesion amount in the width direction of the intermediate transfer belt 6 is made uniform, and the toner blade is prevented from partially curling and edge damage and toner filming due to a partial lack of toner adhesion amount. can do.

  FIG. 6 is a flowchart illustrating the operation of the cleaning device according to the present embodiment. Hereinafter, the operation of the cleaning apparatus 100 will be described with reference to this flowchart.

  When the intermediate transfer belt 6 is cleaned, the control unit 90 interrupts the image forming process of the image forming apparatus A (S601). When this operation is performed by the cleaning apparatus 100, it is necessary to interrupt the image forming process of the image forming apparatus A. Therefore, it is desirable to perform this operation at a predetermined timing, such as a timing at which the influence of the cleaning blade 101 being swollen or damaged, and the occurrence of toner filming, or a timing at which the probability of occurrence thereof increases. .

  Table 1 shows an example of the operation timing of the cleaning device according to the present embodiment.

  Table 1 shows the number of printed sheets as the operation timing of the cleaning device set according to the environmental temperature as the environmental condition and the paper width of the paper. Therefore, this operation by the cleaning device 100 is performed at the timing when the number of printed sheets shown in Table 1 is reached. As described above, this operation is performed every time when the predetermined number of printed sheets set according to the environmental temperature and the paper width of the paper is reached. This is because the probability of toner filming increases. The operation timing of the cleaning device is preferably changed according to the characteristics of the image forming apparatus A.

  Note that the environmental conditions considered when performing this operation by the cleaning device 100 may include humidity in addition to the environmental temperature.

  Further, it is desirable that this operation by the cleaning apparatus 100 is performed even when the apparatus is started up, which is relatively largely affected by the occurrence of wobbling or edge damage of the cleaning blade 101 and toner filming.

  As described above, by performing this operation by the cleaning device 100 when the apparatus is started up or at an appropriate timing according to the environmental conditions and the print processing amount, the image forming efficiency of the image forming apparatus is prevented from deteriorating and the cleaning blade is used. It is possible to efficiently prevent the curling of 101, the damage of the edge, and the occurrence of toner filming.

  The controller 90 releases the pressure contact with the intermediate transfer belt 6 by the cleaning blade 101 (S602), and then restarts the rotation of the intermediate transfer belt 6 (S603). As a result, the toner adheres to the intermediate transfer belt 6 in the storage space 112, and the intermediate transfer belt 6 rotates and travels until the adhered toner reaches the detectable region of the toner sensor 111 while the adhered toner remains. The

  The controller 90 detects the amount of toner remaining on the intermediate transfer belt 6 by the sensor 111. At this time, the amount of toner at a plurality of locations in the width direction of the intermediate transfer belt 6 on the intermediate transfer belt 6 is detected (S604).

Based on the amount of toner at a plurality of locations in the width direction of the intermediate transfer belt 6 on the intermediate transfer belt 6, the control unit 90 determines the amount of toner in the toner band corresponding to each location (S605). The amount of toner in the toner band at least compensates for the difference between the amount of toner necessary to prevent the cleaning blade 101 from curling and edge damage, and toner filming, and the amount of toner detected in step 604. The amount can be. The amount of toner necessary for preventing the cleaning blade 101 from curling, damage to the edge, and toner filming can be set to an appropriate amount based on experience, for example, 1 g / m ² .

  The controller 90 reversely rotates the intermediate transfer belt 6 to return the remaining toner on the intermediate transfer belt 6 to the upstream side of the pressure contact position P on the intermediate transfer belt 6 with respect to the rotation direction of the intermediate transfer belt 6. Thereafter (S606), the cleaning blade 101 is pressed against the intermediate transfer belt 6 (S607). The distance that the intermediate transfer belt 6 travels in the reverse rotation direction in step S606 can be, for example, the same distance as the distance that the intermediate transfer belt 6 is rotationally traveled from step S603 to step S604.

  Instead of rotating the intermediate transfer belt 6 in the reverse direction in a state in which the pressure contact with the intermediate transfer belt 6 by the cleaning blade 101 is released, the intermediate transfer belt 6 is rotated by 1 in the rotation direction during image formation without releasing the pressure contact. The remaining toner may be removed by rotation.

  The controller 90 forms the toner band of the toner amount determined in step S605 on the intermediate transfer belt 6 by the image forming units 10Y, 10M, 10C, and 10K (S608). The toner band corresponds to each location where the amount of toner is detected by the sensor 111 in step S604, and is formed on the extension line in the rotational direction of the intermediate transfer belt 6 from each location. That is, according to the distribution of the actual toner adhesion amount in the width direction of the intermediate transfer belt 6, a toner band including an appropriate amount of toner is formed at a position on the intermediate transfer belt 6 corresponding to each location. As a result, the toner adhesion amount in the width direction of the intermediate transfer belt 6 is made uniform, and even if the toner adhesion amount is partially insufficient, a partial wrinkle or edge of the cleaning blade 101 caused by the toner adhesion amount is caused. Damage and toner filming can be prevented.

  The controller 90 rotates the intermediate transfer belt 6 and resumes image formation (S609). When the rotation of the intermediate transfer belt 6 is resumed, the toner remaining on the intermediate transfer belt 6 in steps S602 to S603 is removed by the cleaning blade 101. In step S608, the toner band formed on the intermediate transfer belt 6 is removed. That is, new toner constituting a toner band is supplied to the cleaning blade 101.

(Example)
Examples of the present embodiment will be described.

  A comparison was made between the result of detecting the amount of adhesion on the intermediate transfer belt again after the present embodiment and the result of detecting the amount of adhesion on the intermediate transfer belt according to the conventional example.

[Conditions and methods]
1. Implementation Conditions and Method of this Example (a) This embodiment was implemented according to the flowchart of FIG.

  (B) The toner band was supplied in a color mode using four color toners. The amount of toner was determined by the amount of toner shown in Table 2 below.

  Table 2 shows the relationship between the detected toner amount and the length of the toner band formed on the intermediate transfer belt.

As shown in Table 2, the toner band is supplied with four toners of cyan (C), magenta (M), yellow (Y), and black (K), and the detected toner amount is 0.2 g / m. ^In the case of less than ^2, the length of the toner band for each color was set to 50 mm. Further, when the detected toner amount is 0.2 g / m ² or more and less than 0.4 g / m ² , the length of the toner band is 40 mm or less, 0.4 g / m ² or more and less than 0.6 g / m ^2. Was 30 mm, 20 mm when 0.6 g / m ² or more and less than 0.8 g / m ² , and 10 mm when 0.8 g / m ² or more and less than 1.0 g / m ² . When the detected toner amount is 1.0 g / m ² or more, no toner band is formed. That is, the amount of toner necessary for preventing the cleaning blade from curling, damage to the edge, and toner filming was set to 1 g / m ² .

  When the toner band is formed in the monochrome mode, the amount of toner in the toner band is the same as the total amount of toner in the four toner bands in the color mode.

  (C) The amount of toner was detected by a line sensor at seven locations in the width direction of the intermediate transfer belt.

  (D) The width of the toner band was a value obtained by dividing the width of the intermediate transfer belt by 7, which is the number of locations for detecting the amount of toner.

  (E) The flowchart of FIG. 6 was implemented, and after the toner band was removed by the cleaning blade, the amount of toner adhering to the intermediate transfer belt in the storage space was detected. At this time, the toner amount was detected as follows. (I) The intermediate transfer belt is rotated to move the toner adhering to the intermediate transfer belt to a position 100 mm downstream of the rotation direction of the intermediate transfer belt with respect to the sensor. (Ii) The amount of toner is detected 10 times each time the intermediate transfer belt travels 1 mm while the intermediate transfer belt is rotated. (Iii) The average of the 10 detections of the toner amount is taken as the toner amount detection result.

  (F) The following components were used for the cleaning device.

  <Casing> The material was hard plastic.

  <Cleaning blade> The material was urethane rubber, the hardness was 70 °, the thickness was 2 mm, and the total length was 350 mm.

  <Blade holder> The thickness was 2 mm with SECC.

  <Storage sheet> The material was PET, and the thickness was 350 mm.

  <Intermediate transfer belt> The material was PI and the thickness was 0.1 mm.

  <Drive roller> The material was hollow aluminum, the thickness was 3 mm, and the outer diameter was φ40 mm.

<Sensor> An IDC sensor was used.
2. Implementation Conditions and Method of Comparative Example (a) As in this example, the toner on the intermediate transfer belt removed by the cleaning blade is stored in a storage space formed by the intermediate transfer belt, the rotating roller, and the storage sheet. Thus, the toner in the storage space was brought into contact with the intermediate transfer belt to adhere the toner.

  (B) The amount of toner stored in seven locations in the width direction of the storage space having the same width as that of the intermediate transfer belt is detected by a line sensor, and each location is handled based on the detected amount of toner at each location. A toner band was formed at the position.

  (C) The width of the toner band was a value obtained by dividing the width of the intermediate transfer belt by 7, which is the number of locations for detecting the amount of toner.

  (D) After the toner band was removed by the cleaning blade, the amount of toner adhering to the intermediate transfer belt in the storage space was detected. The amount of toner was detected in the same manner as in the example.

  (E) Each component of the cleaning device was the same as in the example.

[result]
FIG. 7 is a diagram showing the amount of toner in the width direction of the intermediate transfer belt when this embodiment is carried out in comparison with the conventional example. A of FIG. 7 shows the result of the example which implemented this embodiment, B of FIG. 7 has shown the result of the comparative example.

As shown in FIG. 7A, in this embodiment, the amount of toner adhering at all seven locations in the width direction of the intermediate transfer belt is used to prevent the cleaning blade from curling, damage to the edge, and toner filming. It exceeds the required toner amount of 1 g / m ² .

On the other hand, as shown in FIG. 7B, in the comparative example, the amount of toner adhering at seven locations in the width direction of the intermediate transfer belt is relatively large, and the amount of toner is less than 1 g / m ² . There is a place. Therefore, in order for the amount of toner to exceed 1 g / m ² at all seven locations, the amount of toner in the toner band must be further increased.

  This example demonstrates that the cleaning device according to the present embodiment can optimize the amount of toner supplied as a lubricant and reduce the amount of toner consumed.

  Although the cleaning apparatus and the image forming apparatus according to the embodiment of the present invention have been described above, the present embodiment has the following effects.

  By making it possible to release the pressure contact of the image carrier with the cleaning blade, the toner adhering to the image carrier remains, the remaining toner is detected, and the toner in the toner band formed on the image carrier based on the detected amount The amount of control. As a result, the amount of toner supplied as the lubricant can be optimized to reduce the toner consumption, and the robustness of the image carrier cleaning can be improved.

  In addition, the amount of toner in a plurality of locations in the width direction of the image carrier is detected, and the amount of toner in the toner band formed at the position on the image carrier corresponding to each location is controlled based on the detected amount in each location. To do. As a result, the toner adhesion amount in the width direction of the image carrier is made uniform, and partial cleaning of the cleaning blade, edge damage, and toner filming due to partial lack of toner adhesion are prevented. Can do.

  Further, when removing the toner remaining on the image carrier for detecting the amount of toner, the toner remaining by rotating the image carrier in the reverse direction with the pressure contact to the image carrier by the cleaning blade being released is removed. The pressure is returned to the upstream side with respect to the rotation direction of the image carrier from the pressure contact position on the image carrier. Thereby, the time required for detecting the amount of toner remaining on the image carrier can be shortened.

  Further, the amount of toner remaining on the image carrier is detected when the apparatus is started up or at an appropriate timing according to the environmental conditions and the print processing amount. As a result, it is possible to prevent the image forming efficiency of the image forming apparatus from deteriorating, and to efficiently prevent the cleaning blade from curling, edge damage, and toner filming.

  The cleaning device and the image forming apparatus according to the present invention are not limited to the above-described embodiments.

  For example, in the embodiment described above, the cleaning target of the cleaning device is the intermediate transfer belt, but the cleaning device according to the present invention can also be applied to a photosensitive member (photosensitive drum).

A image forming apparatus,
1C, 1M, 1Y, 1K photosensitive drum,
2C, 2M, 2Y, 2K charging unit,
3C, 3M, 3Y, 3K optical writing unit,
4C, 4M, 4Y, 4K developing device,
6 Intermediate transfer belt,
7A Secondary transfer part,
10C, 10M, 10Y, 10K image forming unit,
90 control unit,
100 cleaning device,
101 cleaning blade,
102 rotating roller,
103 storage sheet,
104 casing,
105 support shaft,
106 blade holder,
107 toner discharge unit,
108 toner receiving sheet,
109 pressure spring,
110 Middle plate,
111 sensors,
200 CPU,
201 RAM,
202 ROM,
203 HDD,
204 External interface,
205 operation unit,
206 display unit,
207 image control unit,
208 reading unit,
209 Printing Department,
210 Cleaning section,
211 Bus.

Claims (14)

A cleaning device used in an image forming apparatus comprising: an image carrier that carries a toner image; and an image forming unit that forms the toner image on the image carrier.
A cleaning blade that presses against the rotating image carrier and removes toner remaining on the image carrier;
Toner supply means for supplying toner to the cleaning blade;
Switching means for switching between the pressure contact of the image carrier by the cleaning blade and the release of the pressure contact;
Detecting means for detecting the amount of toner on the image carrier remaining without being removed by the cleaning blade by releasing the pressure contact with the image carrier that rotates by the cleaning blade by the switching means;
Control means for controlling the amount of toner of the toner image formed on the image carrier by the image forming means based on the amount of toner detected by the detecting means;
A cleaning device comprising: The toner supply means includes
A rotating roller that contacts the image carrier on the upstream side of the position where the image carrier is pressed by the cleaning blade with respect to the rotation direction of the image carrier;
A contact member that contacts the rotating roller,
The toner on the image carrier removed by the cleaning blade is stored in a storage space formed by the image carrier, the rotating roller, and the contact member, and the toner stored in the storage space is stored. 2. The toner is supplied to the cleaning blade pressed against the image carrier through the image carrier by bringing the image carrier into contact with the toner and attaching the toner to the image carrier. A cleaning device according to claim 1. The detection means includes a plurality of sensors that respectively detect amounts of toner at a plurality of locations along a direction orthogonal to the rotation direction of the image carrier on the image carrier.
The control means is configured to detect the amount of toner in the toner image formed on the extension line in the rotation direction of the image carrier from the plurality of places on the image carrier, and to detect the amount of toner in the plurality of places detected by the detection means. The cleaning device according to claim 1, wherein the cleaning device is controlled based on the amount. The detection means detects the amount of toner at a plurality of locations along the direction orthogonal to the rotation direction of the image carrier on the image carrier by scanning in the orthogonal direction on the image carrier. Consisting of sensors,
The control means is configured to detect the amount of toner in the toner image formed on the extension line in the rotation direction of the image carrier from the plurality of places on the image carrier, and to detect the amount of toner in the plurality of places detected by the detection means. The cleaning device according to claim 1, wherein the cleaning device is controlled based on the amount. The detection means comprises a line sensor that simultaneously detects the amount of toner at a plurality of locations along a direction orthogonal to the rotation direction of the image carrier on the image carrier,
The control means is configured to detect the amount of toner in the toner image formed on the extension line in the rotation direction of the image carrier from the plurality of places on the image carrier, and to detect the amount of toner in the plurality of places detected by the detection means. The cleaning device according to claim 1, wherein the cleaning device is controlled based on the amount.   The image carrier by the cleaning blade is used to remove the toner remaining on the image carrier without being removed from the cleaning blade by releasing the pressure contact with the image carrier by the cleaning blade by the switching means. The image carrier is pressed against the rotation direction of the image carrier by the cleaning blade by rotating the image carrier reversely with respect to the rotation direction of the image carrier with the pressure contact with the body being released. The cleaning apparatus according to claim 1, further comprising a reverse rotation control unit that returns the remaining toner on the image carrier upstream of the position.   The detection of the amount of toner on the image carrier by the detection unit is performed at least one of when the apparatus is started up and when the number of prints determined in advance according to environmental conditions is reached. The cleaning apparatus as described in any one of 1-6. An image carrier for carrying a toner image;
Image forming means for forming the toner image on the image carrier;
A cleaning blade that presses against the rotating image carrier and removes toner remaining on the image carrier;
Toner supply means for supplying toner to the cleaning blade;
Switching means for switching between the pressure contact of the image carrier by the cleaning blade and the release of the pressure contact;
Detecting means for detecting the amount of toner on the image carrier remaining without being removed by the cleaning blade by releasing the pressure contact with the image carrier that rotates by the cleaning blade by the switching means;
Control means for controlling the amount of toner of the toner image formed on the image carrier by the image forming means based on the amount of toner detected by the detecting means;
An image forming apparatus comprising: The toner supply means includes
A rotating roller that contacts the image carrier on the upstream side of the position where the image carrier is pressed by the cleaning blade with respect to the rotation direction of the image carrier;
A contact member that contacts the rotating roller,
The toner on the image carrier removed by the cleaning blade is stored in a storage space formed by the image carrier, the rotating roller, and the contact member, and the toner stored in the storage space is stored. 9. The toner is supplied to the cleaning blade pressed against the image carrier through the image carrier by bringing the image carrier into contact with the toner and attaching the toner to the image carrier. The image forming apparatus described in 1. The detection means includes a plurality of sensors that respectively detect amounts of toner at a plurality of locations along a direction orthogonal to the rotation direction of the image carrier on the image carrier.
The control means is configured to detect the amount of toner in the toner image formed on the extension line in the rotation direction of the image carrier from the plurality of places on the image carrier, and to detect the amount of toner in the plurality of places detected by the detection means. The image forming apparatus according to claim 8, wherein each of the image forming apparatuses is controlled based on the amount. The detection means detects the amount of toner at a plurality of locations along the direction orthogonal to the rotation direction of the image carrier on the image carrier by scanning in the orthogonal direction on the image carrier. Consisting of sensors,
The control means is configured to detect the amount of toner in the toner image formed on the extension line in the rotation direction of the image carrier from the plurality of places on the image carrier, and to detect the amount of toner in the plurality of places detected by the detection means. The image forming apparatus according to claim 8, wherein each of the image forming apparatuses is controlled based on the amount. The detection means comprises a line sensor that simultaneously detects the amount of toner at a plurality of locations along a direction orthogonal to the rotation direction of the image carrier on the image carrier,
The control means is configured to detect the amount of toner in the toner image formed on the extension line in the rotation direction of the image carrier from the plurality of places on the image carrier, and to detect the amount of toner in the plurality of places detected by the detection means. The image forming apparatus according to claim 8, wherein each of the image forming apparatuses is controlled based on the amount.   The image carrier by the cleaning blade is used to remove the toner remaining on the image carrier without being removed from the cleaning blade by releasing the pressure contact with the image carrier by the cleaning blade by the switching means. The image carrier is pressed against the rotation direction of the image carrier by the cleaning blade by rotating the image carrier reversely with respect to the rotation direction of the image carrier with the pressure contact with the body being released. The image forming apparatus according to claim 8, further comprising a reverse rotation control unit that returns the toner on the remaining image carrier upstream of the position.   The detection of the amount of toner on the image carrier by the detection unit is performed at least one of when the apparatus is started up and when the number of prints determined in advance according to environmental conditions is reached. The image forming apparatus according to any one of 8 to 13.

Images