Image forming device

Abstract

To suppress the occurrence of an adverse effect in an image resulting from a cleaning failure.SOLUTION: An image forming apparatus controls to perform an image forming operation, which forms a toner image on a recording material, and a toner supply operation, which supplies a toner to a cleaning blade nip portion. The image forming apparatus sets a region of an image carrier facing a developer carrier at a developing portion as a first region, sets a region of the image carrier facing the developer carrier at the developing portion after the region of the developer carrier facing the first region makes one revolution as a second region, sets a region between the first region and the second region as a third region. When the toner supply operation is performed, the image forming apparatus forms, in the third region, a toner supply pattern formed from a first pattern for exposing and a second pattern for not exposing or for exposing with an exposure amount smaller than an exposure amount with which the first pattern exposes. In the toner supply pattern, the length of the second pattern is larger than the length of the first pattern in a rotational direction, and the first pattern and the second pattern are repeatedly formed.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] Image forming devices such as printers that use an electrophotographic image forming method have a configuration in which a process cartridge is detachable. In a process cartridge, a toner image on an image carrier (hereinafter referred to as a photosensitive member or drum) may remain after being transferred to a recording material. A known method for removing the remaining toner is to bring a cleaning member into contact with the surface of the drum. A widely used cleaning member is configured to include an elastic body made of urethane rubber or the like and a supporting metal plate that supports the elastic body.

[0003] However, a new process cartridge does not have a cleaning-blocking layer made of an external additive between the drum and the cleaning member, and the cleaning performance is unstable, which can lead to the problem of poorly cleaned images.

[0004] To address this issue, Patent Document 1 proposes a toner supply sequence that efficiently discharges toner onto the drum when a new product is used, thereby suppressing image defects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-187707 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the configuration of Patent Document 1 had the following problems. For example, when a new drum is first used, the initial friction coefficient is high, and if the amount of toner supplied per unit area of ​​the drum in the toner supply sequence is large in an L / L (low temperature / low humidity) environment (15°C / 10%), toner may slip through the cleaning member. In such cases, poor cleaning results in image degradation. [Means for solving the problem]

[0007] Therefore, the present invention has been made in consideration of the above-mentioned problems, and provides a cleaning device comprising: a rotatable image carrier; an exposure unit that exposes the surface of the image carrier to light to form an electrostatic latent image on the surface of the image carrier; a rotatable developer carrier that supplies toner to the surface of the image carrier in a developing section to develop the electrostatic latent image as a toner image; and a cleaning member that comes into contact with the image carrier to form a contact section and removes toner adhering to the surface of the image carrier at the contact section. a memory for storing information for determining whether the toner is in a ready-to-use state;In an image forming apparatus including a control unit that controls the image carrier and the developer carrier to rotate and the exposure unit to perform i) an image forming operation of forming the toner image on a recording material, and ii) a toner supplying operation that is an operation different from the image forming operation and moves the toner from the developer carrier to the image carrier and supplies it to the contact portion, while the image carrier and the developer carrier are rotating, a region of the image carrier that faces the developer carrier in the developing unit is referred to as a first region, and a region of the image carrier that faces the developer carrier in the developing unit after the region of the developer carrier that faces the first region has made one revolution is referred to as a second region. and a region of the image carrier between the first region and the second region in the rotation direction of the image carrier is defined as a third region, the control unit, when performing the toner supply operation, controls to form a toner supply pattern in the third region, the toner supply pattern being formed from a first pattern, a part of which is exposed by the exposure unit, and a second pattern, a part of which is not exposed or a part of which is exposed with an exposure amount smaller than that for exposing the first pattern, the toner supply pattern being configured such that a length of the second pattern is longer than a length of the first pattern in the rotation direction, and the first pattern and the second pattern are repeatedly formed. and the control unit controls to execute a first toner supply operation using a first toner supply pattern when the information stored in the memory is iii) information that the toner is in a start-of-use state, and iv) when the information that the toner is not in a start-of-use state, to execute a second toner supply operation that is different from the first toner supply operation using the first toner supply pattern, the second toner supply operation using a second toner supply pattern that is different from the first toner supply pattern. It is characterized by the following. [Effects of the Invention]

[0008] According to the present invention, it is possible to suppress the occurrence of image defects due to poor cleaning. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view of a process cartridge according to the first embodiment. [Figure 3] FIG. 2 is a block diagram showing a control configuration of the image forming apparatus according to the first embodiment. [Figure 4] FIG. 2 is a surface diagram of the photoreceptor in Example 1 after surface roughening treatment. [Figure 5] 1 is a schematic view of a surface roughening treatment device for a photosensitive member in Example 1. FIG. [Figure 6] FIG. 2 is a schematic diagram of the toner in Example 1. [Figure 7] 1 is a flowchart according to the first embodiment. [Figure 8] FIG. 2 is an explanatory diagram of a toner supply pattern in Examples 1 to 3. [Figure 9] FIG. 2 is a diagram illustrating the definition of regions on the surface of a photoreceptor in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description is an example and does not limit the present invention to its contents. Furthermore, in the following drawings, components that are not necessary for the description of the embodiments will be omitted as appropriate. For convenience, the magnitude (high / low) of voltage or potential refers to the magnitude (high / low) when compared in absolute value, unless otherwise specified.

[0011] Example 1 <Overall configuration of image forming apparatus> First, the overall configuration of the image forming apparatus of this embodiment will be described. FIG. 1 is a schematic cross-sectional view of the image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment is a full-color laser printer that employs an inline system and an intermediate transfer system. The image forming apparatus 100 can form a full-color image on a sheet-like recording material P (e.g., recording paper, plastic sheet, cloth, etc.) in accordance with image information. The image information is input to the image forming apparatus 100 from an external device (not shown), such as an image reading device or a personal computer, that is communicably connected to the image forming apparatus 100.

[0012] The image forming apparatus 100 includes multiple image forming units, namely, first, second, third, and fourth image forming units SY, SM, SC, and SK, for forming images of yellow (Y), magenta (M), cyan (C), and black (K), respectively. The same or corresponding elements provided for each color may be generally described by omitting the Y, M, C, or K suffix to the reference numerals indicating the element for that color. In this embodiment, the image forming unit S is comprised of a photoreceptor 1 serving as an image carrier, a charging roller 2 serving as a charging member, an exposure device 3 serving as an exposure unit, a developing device 4 serving as a developing unit, and a cleaning device 5 serving as a cleaning unit. In this embodiment, the image forming unit S further includes a pre-exposure device 6 serving as a pre-exposure unit. In this embodiment, the exposure device 3 is configured as a single unit that exposes the photoreceptor 1 of each image forming unit S, but it may also be provided independently for each image forming unit S. In each image forming station S, a photosensitive member 1, a charging roller 2 as a process means acting on the photosensitive member 1, a developing device 4, and a cleaning device 5 are integrated to form a process cartridge 7. Figure 2 is a schematic cross-sectional view showing one representative process cartridge 7.

[0013] A rotatable drum-type (cylindrical) photosensitive member (photosensitive drum) 1, which serves as an image carrier for carrying an electrostatic latent image and a toner image, is driven to rotate in the direction of arrow R1 (clockwise) in FIG. 2 by a driving force transmitted from a driving unit 80 (FIG. 3) serving as a driving means. In this embodiment, four photosensitive members 1 are arranged side by side in a direction intersecting the vertical direction. In this embodiment, the rotational speed of the photosensitive member 1 is 321 mm / sec in normal mode. As will be described later, the rotational speed of the photosensitive member 1 in low-speed mode, which is slower than that in normal mode, is 91 mm / sec. The rotational speed of the photosensitive member 1 is also the speed at which image processing is performed during image formation, and is therefore sometimes collectively referred to as PS (process speed).

[0014] The surface of the rotating photoreceptor 1 is charged to a predetermined potential of a predetermined polarity (negative polarity in this embodiment) by a charging roller 2, which is a roller-type charging member serving as a charging means. In this embodiment, the charging roller 2 is a single-layer roller consisting of a conductive core and a conductive rubber layer (elastic layer) provided around the core, and has an outer diameter of 7.5 mm and a volume resistivity of 10 3 ~10 6 The resistance is Ω·cm. The charging roller 2 is disposed in contact with the surface of the photoreceptor 1, pressed against the photoreceptor 1, and rotates in accordance with the rotation of the photoreceptor 1. During image formation (charging), a predetermined charging voltage (charging bias) is applied to the charging roller 2 from a charging power supply (high-voltage power supply) 71 (FIG. 3) serving as a charging voltage application unit. This is a direct current (DC) voltage of a predetermined polarity (negative in this embodiment). In this embodiment, a charging voltage of −1000 V is applied to the charging roller 2, and the surface of the photoreceptor 1 is uniformly charged to −500 V, which is Vd, the dark area potential (non-image area potential). In other words, a DC charging voltage Vd+Vth is applied to the charging roller 2, and the surface of the photoreceptor 1 is uniformly charged to Vd through discharge. Here, Vd is the dark area potential (non-image area potential), which is −500 V in this embodiment. Vth is the discharge start voltage, which is −500 V in this embodiment. When the charging voltage applied to the charging roller 2 is small, the surface potential on the photosensitive member 1 does not increase due to discharge, but when the charging voltage applied to the charging roller 2 reaches or exceeds the discharge start voltage Vth, the surface potential of the photosensitive member 1 begins to increase due to discharge. The position in the rotation direction of the photosensitive member 1 where the charging roller 2 charges the surface of the photosensitive member 1 is the charging portion (charging position) P1. In this embodiment, the surface of the photosensitive member 1 is charged by discharge that occurs in minute gaps formed upstream and downstream of the contact point between the photosensitive member 1 and the charging roller 2 in the rotation direction of the photosensitive member 1. However, for convenience, the contact point between the photosensitive member 1 and the charging roller 2 may also be considered as the charging portion P1.

[0015] The charged surface of the photoreceptor 1 is scanned and exposed by an exposure device 3 serving as an exposure means or exposure unit, and an electrostatic latent image (electrostatic image) is formed on the photoreceptor 1. The exposure device 3 irradiates the surface of the photoreceptor 1 with laser light based on image information, forming an electrostatic latent image on the photoreceptor 1. The surface potential of the photoreceptor 1 irradiated with the laser light changes to -100 V, which is the light area potential (image area potential) Vl. The position in the rotation direction of the photoreceptor 1 where the exposure device 3 irradiates the surface of the photoreceptor 1 with light is the exposure area (exposure position) P2.

[0016] The electrostatic latent image formed on the photoreceptor 1 is developed (visualized) by the developing device 4, which serves as a developing means, by supplying toner as a developer, and a toner image (toner image, developer image) is formed on the photoreceptor 1. The developing device 4 has a developing roller 41 as a developing member (developer carrier). The developing roller 41 has an outer diameter of φ12, and the ratio of the peripheral speed of the developing roller 41 to the rotation speed of the photoreceptor 1 is 90%. During image formation (development), a predetermined developing voltage (developing bias), which is a DC voltage of a predetermined polarity (negative in this embodiment), is applied to the developing roller 41 by a developing power supply (high-voltage power supply) 72 ( FIG. 3 ), which serves as a developing voltage application unit. In this embodiment, a developing voltage Vdc of −300 V is applied to the developing roller 41, causing toner to adhere to the Vl portion on the photoreceptor 1. In this way, in this embodiment, toner charged with the same polarity as the charge polarity of the photoconductor 1 (negative in this embodiment) adheres to the image area on the photoconductor 1, which has been uniformly charged and then exposed to light to reduce its potential (reverse development method). In this embodiment, the normal charge polarity of the toner, which is the main charge polarity of the toner during development, is negative. The developing device 4 will be described in further detail below. The position in the rotational direction of the photoconductor 1 where the developing device 4 supplies toner to the surface of the photoconductor 1 (the contact point between the photoconductor 1 and the developing roller 41 in this embodiment) is the developing unit (developing position) P3.

[0017] An intermediate transfer belt 31, which is an endless belt serving as an intermediate transfer body, is disposed facing the four photoreceptors 1. The intermediate transfer belt 31 is stretched around a plurality of tension rollers, namely, a drive roller 33 and a tension roller 34, and tensioned with a predetermined tension. The intermediate transfer belt 31 rotates (circulates or moves around) in the direction of arrow R2 (counterclockwise) in FIG. 1 when the drive roller 33 is driven to rotate by a driving force transmitted from a drive unit 80 (FIG. 3) serving as a driving means. Primary transfer rollers 32, which are roller-type primary transfer members serving as primary transfer means, are disposed on the inner circumferential surface of the intermediate transfer belt 31, facing each photoreceptor 1 via the intermediate transfer belt 31. The primary transfer rollers 32 are pressed against the photoreceptors 1 and come into contact with the photoreceptors 1 via the intermediate transfer belt 31, forming a primary transfer portion (primary transfer nip) N1 where the photoreceptors 1 and the intermediate transfer belt 31 come into contact. At the primary transfer portion N1, the toner image formed on the photoreceptor 1 is transferred (primary transfer) onto the rotating intermediate transfer belt 31, which serves as the transfer recipient, by the action of the primary transfer roller 32. During image formation (primary transfer), a primary transfer voltage (primary transfer bias), which is a DC voltage of opposite polarity (positive polarity in this embodiment) to the normal charge polarity of the toner, is applied to the primary transfer roller 32 by a primary transfer power supply (high-voltage power supply) 73 (FIG. 3) serving as a primary transfer voltage application portion. For example, when forming a full-color image, the yellow (Y), magenta (M), cyan (C), and black (K) toner images formed on each photoreceptor 1 are sequentially transferred onto the intermediate transfer belt 31 so as to be superimposed on top of each other. The position where the toner image is transferred from the surface of the photoreceptor 1 to the intermediate transfer belt 31 in the rotational direction of the photoreceptor 1 is the primary transfer position P4 (the primary transfer portion N1, which is the contact point between the photoreceptor 1 and the intermediate transfer belt 31 in this embodiment).

[0018] A secondary transfer roller 9, a roller-type secondary transfer member serving as a secondary transfer means, is disposed on the outer peripheral surface of the intermediate transfer belt 31, facing the drive roller 33, which also serves as a secondary transfer opposing roller. The secondary transfer roller 9 is pressed against the drive roller 33 and contacts the drive roller 33 via the intermediate transfer belt 31, forming a secondary transfer portion (secondary transfer nip) N2 where the intermediate transfer belt 31 and the secondary transfer roller 9 contact each other. The toner image formed on the intermediate transfer belt 31 is transferred (secondarily transferred) to a recording material P, serving as a transfer target, which is sandwiched and transported between the intermediate transfer belt 31 and the secondary transfer roller 9 at the secondary transfer portion N2. During image formation (secondary transfer), a secondary transfer voltage (secondary transfer bias), which is a DC voltage of the opposite polarity (positive polarity in this embodiment) to the normal charging polarity of the toner, is applied to the secondary transfer roller 9 by a secondary transfer power supply (high-voltage power supply) 74 ( FIG. 3 ) serving as a secondary transfer voltage application portion. The recording material (transfer material, recording medium, sheet) P is stored in a cassette 10 serving as a recording material storage section, and is sent out of the cassette 10 by a feed roller 11 serving as a feeding member, and is sent to a registration roller 12 serving as a conveying member. The registration roller 12 conveys the recording material P to the secondary transfer section N2 in synchronization with the toner image on the intermediate transfer belt 31.

[0019] The recording material P onto which the toner image has been transferred is conveyed to a fixing device 13 serving as a fixing means. The fixing device 13 applies heat and pressure to the recording material P bearing the unfixed toner image, thereby fixing (melting and adhering) the toner image onto the recording material P. The recording material P onto which the toner image has been fixed is discharged (output) to a tray 14 serving as a discharge unit provided outside the apparatus main body 110 of the image forming apparatus 100.

[0020] On the other hand, after the toner image is transferred to the intermediate transfer belt 31, the surface potential of the photoconductor 1 becomes uneven due to the primary transfer voltage. The pre-exposure device 6, which serves as a charge removal device, pre-exposes the surface of the photoconductor 1 (full-surface exposure, full-surface light irradiation), thereby leveling out the uneven surface potential of the photoconductor 1 caused by the previous image formation. In other words, pre-exposure removes residual charge from the surface of the photoconductor 1. The pre-exposure device 6 exposes the surface of the photoconductor 1 downstream of the primary transfer station P4 and upstream of the charging station P1 in the direction of rotation of the photoconductor 1. The light source for the pre-exposure device 6 can be an LED, a halogen lamp, or the like. While there is no particular limitation on the light source used, an LED is preferred due to its low driving voltage and ease of device miniaturization. In this embodiment, an LED was used as the light source for the pre-exposure device 6. The position in the direction of rotation of the photoconductor 1 where the pre-exposure device 6 irradiates the surface of the photoconductor 1 with light is the pre-exposure section (pre-exposure position) P5.

[0021] Furthermore, toner remaining on the surface of the photoreceptor 1 without being transferred to the intermediate transfer belt 31 (primary transfer residual toner) is removed and collected from the surface of the photoreceptor 1 by a cleaning device 5 serving as a photoreceptor cleaning means. The cleaning device 5 uses a cleaning blade 51, a cleaning member that contacts the surface of the photoreceptor 1, to scrape the transfer residual toner from the surface of the rotating photoreceptor 1. A contact point P6 is formed when the cleaning blade 51 contacts the surface of the photoreceptor 1, forming a nip where a blocking layer is formed. The waste toner is then collected in a waste toner collection chamber 52 located below the cleaning blade 51. In this embodiment, the contact point P6 and the nip are distinguished for convenience, since the initial state in which a blocking layer is not formed at the contact point P6 will also be described. However, after toner and external additives are supplied to the contact point P6, the terms contact point P6 and nip are used interchangeably. The setting conditions for the cleaning blade 51 in this embodiment are as follows. The set angle with respect to the photosensitive member 1 was 22°, the penetration amount was 1.0 mm, and the hardness of the cleaning blade 51 was 70 degrees (Asker-C, 500 gf load).

[0022] In addition, any deposits such as toner (secondary transfer residual toner) remaining on the surface of the intermediate transfer belt 31 without being transferred to the recording material P are removed and collected from the surface of the intermediate transfer belt 31 by a belt cleaning device 35 serving as an intermediate transfer body cleaning means.

[0023] The intermediate transfer belt 31 can be brought into contact with and separated from each photosensitive member 1 by a belt contact / separation mechanism 90 (FIG. 3). In this embodiment, the belt contact / separation mechanism 90 separates the intermediate transfer belt 31 from the photosensitive member 1 by moving the primary transfer roller 32 in a direction away from the photosensitive member 1. The belt contact / separation mechanism 90 is also configured to bring the intermediate transfer belt 31 into contact with the photosensitive member 1 by moving the primary transfer roller 32 in a direction approaching the photosensitive member 1.

[0024] <Process cartridge configuration> Next, a further description will be given of the process cartridge 7 to be mounted in the image forming apparatus 100 of this embodiment.

[0025] The process cartridge 7 is detachably mounted in the main body 110 of the image forming apparatus 100 via mounting means (not shown), such as a mounting guide or a positioning member, provided in the image forming apparatus 100. In this embodiment, the main body 110 refers to the image forming apparatus 100 excluding the process cartridge 7. In this embodiment, the process cartridges 7 for each color all have the same shape, and each process cartridge 7 contains toner t of each color: yellow (Y), magenta (M), cyan (C), and black (K). In this embodiment, the configuration and operation of the process cartridges 7 for each color are substantially identical, except for the type (color) of toner t they contain. The process cartridge 7 includes a developing device (developing unit) 4 and a photosensitive unit 8.

[0026] The developing device (developing unit) 4 has a developing container (developing frame) 46. The developing container 46 is partitioned into a developing chamber 46a and a toner containing chamber (developer containing portion) 46b.

[0027] The toner storage chamber 46b stores toner t, which is a non-magnetic single-component developer. A toner transport member (developer transport member) 44 is provided within the toner storage chamber 46b. The toner transport member 44 is driven to rotate in the direction of arrow R5 in FIG. 2 (clockwise direction) by a driving force transmitted from a driving unit 80 (FIG. 3) serving as a driving means, and transports the toner t to the developing chamber 46a.

[0028] A developing roller 41 serving as a developing member (developer carrier) is disposed in the developing chamber 46a. During image formation (development), the developing roller 41 is brought into contact with the photosensitive member 1 and is driven to rotate in the direction of arrow R3 (counterclockwise) in FIG. 2 by a driving force transmitted from a driving unit 80 serving as a driving means. In this embodiment, the developing roller 41 and the photosensitive member 1 rotate so that their surfaces move in a forward direction in the developing portion P3 where they face each other (contact each other). In this embodiment, the developing roller 41 is made of a conductive core metal and a conductive rubber layer (elastic layer) provided around the core metal. The rotation direction of the developing roller 41 is not limited to the rotation direction in this embodiment, and may be a rotation direction in which the surface of the developing roller 41 and the surface of the photosensitive member 1 move in opposite directions in the developing portion P3.

[0029] Furthermore, a supply roller 42 is disposed in the developing chamber 46a as a supply member that supplies toner t conveyed from the toner storage chamber 46b to the developing roller 41. The supply roller 42 is disposed in contact with the developing roller 41. During image formation (development), the supply roller 42 is driven to rotate in the direction of arrow R4 in FIG. 2 (counterclockwise direction) by a driving force transmitted from a driving unit 80 serving as a driving means. In this embodiment, the supply roller 42 and the developing roller 41 rotate such that the surfaces of the supply roller 42 and the developing roller 41 move in opposite directions at their contact portions. The rotation direction of the supply roller 42 is not limited to the rotation direction in this embodiment, and may be a rotation direction in which the surfaces of the supply roller 42 and the developing roller 41 move in the forward direction at their contact portions.

[0030] Furthermore, in the developing chamber 46a, a developing blade 43 is disposed as a regulating member that regulates the coating amount of the toner t on the developing roller 41 supplied by the supply roller 42 and also applies a charge to the toner t.

[0031] Independent voltages are applied to the developing roller 41, the supply roller 42, and the developing blade 43 from a high-voltage power supply. The toner t supplied to the developing roller 41 by the supply roller 42 is frictionally charged by the friction between the developing roller 41 and the developing blade 43, and is given an electric charge and its layer thickness is regulated. The toner t on the developing roller 41, whose layer thickness has been regulated, is transported by the rotation of the developing roller 41 to the developing section P3, which is the portion facing (contacting) the photosensitive member 1, and adheres to the image portion of the electrostatic latent image on the photosensitive member 1, forming a toner image on the photosensitive member 1.

[0032] During image formation (development), a predetermined development voltage (development bias) Vdc, which is a DC voltage of a predetermined polarity (negative in this embodiment), is applied to the development roller 41 by a development power supply (high-voltage power supply) 72 (FIG. 3) serving as a development voltage application unit. In this embodiment, the development voltage Vdc is set to -300 V. As a result, in the development unit P3, the development contrast Vcont (=Vl-Vdc), which is the potential difference between the light area potential Vl on the photoreceptor 1 and the development bias (the potential of the development roller 41), is +200 V. Also, during image formation (development), a predetermined supply voltage (supply bias) Vrs, which is a DC voltage of a predetermined polarity (negative in this embodiment), is applied to the supply roller 42 by a supply power supply (high-voltage power supply) 75 (FIG. 3) serving as a supply voltage application unit. In this embodiment, the supply voltage Vrs is set to -350 V. The amount of toner t supplied to the development roller 41 can be adjusted by adjusting the potential difference (ΔVr) between the supply roller 42 and the development roller 41. In this embodiment, ΔVr (=Vdc-Vrs) is set to +50V. This sets the potential so that the negatively charged toner t can easily move from the supply roller 42 to the development roller 41. During image formation (development), a predetermined regulated voltage (regulated bias), which is a DC voltage of a predetermined polarity (negative in this embodiment), is applied to the development blade 43 by a regulated power supply (high-voltage power supply) 76 (FIG. 3) serving as a regulated voltage application unit. In this embodiment, the regulated voltage is set to -350V, similar to the supply voltage. Note that the settings of the development bias Vdc and the like are default settings when the apparatus main body 110 and process cartridge 7 are in a brand new state.

[0033] As mentioned above, unless otherwise specified, the magnitude (high / low) of voltage or potential refers to the magnitude (high / low) when compared in absolute value. In other words, with respect to potential or applied voltage, a high potential refers to an absolute value that is larger on the negative polarity side (e.g., -1000 V compared to -500 V), and a low potential refers to an absolute value that is smaller on the negative polarity side (e.g., -300 V compared to -500 V). This is because, in this embodiment, negatively charged toner t is considered as the reference. Furthermore, voltage is expressed as a potential difference from the earth potential (0 V). Therefore, a development voltage of -300 V means that the development voltage applied to the core of the development roller 41 has a potential difference of -300 V compared to the earth potential. This also applies to other voltages, such as charging voltage.

[0034] The photosensitive unit 8 has a photosensitive unit container (photosensitive unit frame) 53. The photosensitive element 1 is rotatably mounted in the photosensitive element container 53 via a bearing (not shown). The photosensitive element 1 is driven to rotate in the direction of arrow R1 (clockwise) in FIG. 2 by receiving a driving force transmitted from a drive unit 80 (FIG. 3) serving as a driving means. The photosensitive element 1 also includes a charging roller 2 and a cleaning blade 51, which is a plate-shaped elastic body, arranged in contact with the surface (outer periphery) of the photosensitive element 1. The charging roller 2 is rotatably mounted in the photosensitive element container 53 via a bearing (not shown). One end (fixed end) of the cleaning blade 51 is fixed to a metal plate attached to the photosensitive element container 53, and the other end (free end) abuts against the photosensitive element 1, forming a cleaning nip, which is the contact point with the photosensitive element 1. The cleaning blade 51 rubs against the surface of the photosensitive member 1, scraping off toner t and fine particles remaining on the photosensitive member 1 after the primary transfer process, and stores the scraped toner in a waste toner storage chamber 52 formed in the photosensitive member unit container 53. This prevents the toner t from adhering to the charging roller 2 or from being carried around by the photosensitive member 1, preventing proper image formation. The cleaning blade 51 and the waste toner storage chamber 52 (photosensitive member unit container 53) form a cleaning device 5.

[0035] The image forming apparatus 100 also includes a contact / separation mechanism 60 for contacting and separating each developing roller 41 with and from each photosensitive member 1. In this embodiment, the developing container 46 is swingably coupled to the photosensitive member unit container 53, and the developing container 46 is biased in a direction in which the developing roller 41 contacts the photosensitive member 1 by a pressure spring, which is a biasing member serving as a biasing means. The contact / separation mechanism 60 is configured to move (rotate) the developing container 46 against the biasing force of the pressure spring, thereby separating the developing roller 41 from the photosensitive member 1. The contact / separation mechanism 60 is also configured to allow the developing container 46 to move (rotate) due to the biasing force of the pressure spring, thereby contacting the developing roller 41 with the photosensitive member 1. In this embodiment, when the image forming apparatus 100 is stopped, the developing roller 41 is separated from the photosensitive member 1 by the contact / separation mechanism 60. During image formation (development), the developing roller 41 is brought into contact with the photosensitive member 1 by the contact / separation mechanism 60. The contact / separation mechanism 60 is driven by a driving force transmitted from a driving unit 80 (FIG. 3) serving as a driving means.

[0036] <Control configuration of image forming apparatus> Next, a description will be given of the control configuration of the image forming apparatus 100 of this embodiment. Fig. 3 is a block diagram showing the control configuration of the main parts of the image forming apparatus 100 of this embodiment.

[0037] The image forming apparatus 100 is provided with a control unit 202 that controls the operation of the image forming apparatus 100. Signals indicating various types of information are input to and output from the control unit 202 via electrical connections. The control unit 202 processes signals input from various process devices and sensors, and processes signals output to instruct the various process devices to operate. A controller 200 provided in the image forming apparatus 100 inputs and outputs various signals to and from an external device (host device), and inputs and outputs various signals to and from the control unit 202 via an interface 201 provided in the image forming apparatus 100. The control unit 202 comprehensively controls the operation of the image forming apparatus 100 in accordance with a predetermined control program and lookup table in response to instructions from the controller 200.

[0038] The control unit 202 includes a CPU 221 as a processing means that is a central element for performing various arithmetic operations, and a main memory 222 such as a RAM, a ROM, and a nonvolatile memory that is a storage element for storing information. The RAM temporarily stores the detection results of the sensors, the count results of the counters, the calculation results, etc. The ROM stores a control program and data tables obtained in advance through experiments, etc. The nonvolatile memory stores the count results of the counters, various setting information, the results of the sensors, etc. The control unit 202 is connected to each control target, sensor, counter, etc. in the image forming apparatus 100. The control unit 202 controls the input and output of various signals and the timing of driving each unit, thereby controlling a predetermined image formation sequence, etc.

[0039] The control unit 202 controls, for example, the charging power supply 71, the developing power supply 72, the supply power supply 75, the regulating power supply 76, the exposure device 3, the primary transfer power supply 73, the secondary transfer power supply 74, and the drive unit 80. In addition, the control unit 202 controls the contact / separation mechanism 60, the charging current detection unit (charging current detection circuit) 61 that detects the charging current flowing in the charging unit P1 (charging roller 2, charging power supply 71), and the belt contact / separation mechanism 90.

[0040] Although not shown in the drawings, in this embodiment, the charging power supply 71, the developing power supply 72, the supply power supply 75, the regulating power supply 76, the primary transfer power supply 73, the contact / separation mechanism 60, and the charging current detection unit 61 are provided independently for each image forming unit S. The drive unit 80 includes a drive motor as a drive source, a drive transmission member, and the like. The drive sources that drive the photoconductor 1, the intermediate transfer belt 31, the rotating members of the developing device 4, the contact / separation mechanism 60, and the belt contact / separation mechanism 90 may be provided independently, or at least some of them may be shared. The drive sources that drive the elements for each color may be provided independently, or at least some of them may be shared.

[0041] Here, the image forming apparatus 100 executes an image forming operation (print job), which is a series of operations initiated by a single start command to form and output an image on one or more recording materials P. The image forming operation generally includes an image forming process, a pre-process (pre-rotation process, pre-printing operation), a paper-interval process when forming images on multiple recording materials P, and a post-process (post-rotation process, post-printing operation). The image forming process is a period during which an electrostatic latent image of the image to be actually formed and output on the recording material P is formed, a toner image is formed, and the toner image is first transferred, second transferred, and fixed. This period is referred to as the image formation time. More specifically, the timing of the image formation time varies depending on the position where each of the processes of charging, exposure, development, first transfer, second transfer, and fixing is performed. The pre-process is a period from when a start command is input until the actual start of image formation, during which preparatory operations are performed before the image forming process. The paper-interval process is a period corresponding to the interval between recording materials P when image formation is performed continuously on multiple recording materials P (continuous image formation). The post-rotation process is a period during which a tidying operation (preparatory operation) is performed after the image forming process. The non-image formation period refers to a period other than image formation, including the pre-process, inter-sheet process, and post-process, as well as the pre-multiple rotation process, which is a preparatory operation when the image forming apparatus 100 is turned on or when the image forming apparatus 100 returns from a sleep state. In this embodiment, the toner supply operation, which will be described later, can be performed. The toner supply operation is performed at a timing different from the image forming operation, and supplies toner t from the developing roller 41 to the photosensitive member 1 and to the contact portion P6 between the cleaning blade 51 and the photosensitive member 1. Regarding the toner supply operation, a first toner supply operation and a second toner supply operation can be performed based on the conditions stored in memory m1. The first toner supply operation and the second toner supply operation will be described in detail later. The first toner supply operation is primarily performed when the process cartridge 7 is initially installed in the image forming apparatus 100. The second toner supply operation is performed after the first toner supply operation.

[0042] <Photoreceptor structure> Next, the photoreceptor 1 in this embodiment will be further described.

[0043] The photoreceptor 1 can be constructed by providing a photosensitive material such as OPC (organic photoconductor), amorphous selenium, or amorphous silicon on a cylindrical drum substrate made of aluminum, nickel, or the like. Furthermore, the photoreceptor 1 can be provided with a wear-resistant protective layer on its outermost surface to improve wear resistance. Providing a protective layer can improve the durability of the photoreceptor 1. In this embodiment, the photoreceptor 1 is an OPC photoreceptor whose photosensitive layer is made of an organic photoconductor. In this embodiment, the photoreceptor 1 is comprised of a cylindrical, conductive metal support having an outer diameter of 24 mm, a conductive layer serving as an undercoat layer for the support, a photosensitive layer (charge generation layer, charge transport layer) formed on the undercoat layer, and a protective layer formed on the photosensitive layer.

[0044] The protective layer preferably contains conductive particles and / or a charge transport material and a resin. Examples of conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, and indium oxide. Examples of charge transport materials include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these materials. Among these, triarylamine compounds and benzidine compounds are preferred. Examples of resins include polyester resins, acrylic resins, phenoxy resins, polycarbonate resins, polystyrene resins, phenolic resins, melamine resins, and epoxy resins. Among these, polycarbonate resins, polyester resins, and acrylic resins are preferred.

[0045] The protective layer may also be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group. Examples of the reaction include thermal polymerization, photopolymerization, and radiation-induced polymerization. Examples of the polymerizable functional group possessed by the monomer having a polymerizable functional group include an acrylic group and a methacrylic group. A material having charge transport capability may also be used as the monomer having a polymerizable functional group.

[0046] The protective layer may also contain additives such as antioxidants, ultraviolet absorbers, plasticizers, leveling agents, slippage-imparting agents, and abrasion resistance improvers. Specific examples of such additives include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles.

[0047] The average thickness of the protective layer is preferably 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 7 μm or less In this example, the average thickness of the protective layer was set to 3 μm.

[0048] The protective layer can be formed by preparing a coating solution for the protective layer containing the above-mentioned materials and solvent, forming a coating film from the coating solution, and drying and / or curing the coating film. Examples of the solvent used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, sulfoxide-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[0049] Furthermore, in this embodiment, a roughening treatment is performed on the surface of the photoreceptor 1. When a photoreceptor 1 that has been subjected to an appropriate roughening treatment is used, the metal soap 45c fills the grooves formed on the surface of the photoreceptor 1, and the metal soap 45c is not removed but remains on the surface of the photoreceptor 1. Therefore, the effect of the metal soap application operation is further sustained, and the metal soap 45c can be stably applied to the surface of the photoreceptor 1 for a long period of time.

[0050] In order to achieve the above-described effects, when the surface of the photoreceptor 1 is subjected to a roughening treatment, the photoreceptor 1 that satisfies the following conditions is used. The ten-point average surface roughness (Rz) of the peripheral surface of the photoreceptor 1 is 0 < Rz ≤ 0.70 (μm) (preferably, 0.10 ≤ Rz ≤ 0.50 (μm)), and the average interval (Sm) of the irregularities on the peripheral surface is 0 < Sm ≤ 70 (μm) (preferably, 5 ≤ Sm ≤ 70 (μm)). By setting the above range, it is possible to stably maintain the metal soap 45c on the surface of the photoreceptor 1, and as a result, image flow can be suppressed over a long period. Therefore, in the present embodiment, it is characterized in that the durability of the photoreceptor 1 is maintained even in a configuration with a longer lifespan by performing a roughening treatment to form appropriate irregularities on the surface of the photoreceptor 1.

[0051] In the photoreceptor 1 of the present embodiment, in order to maintain the durability of the photoreceptor 1, a roughening treatment for forming minute irregularities on the surface is performed. According to Japanese Patent No. 4027407, on the peripheral surface of the photoreceptor 1, grooves having a width within a range of 0.5 μm or more and 40 μm or less and extending in a substantially circumferential direction of the peripheral surface are formed in a plurality in the longitudinal direction (the busbar direction, the direction of the rotation axis of the photoreceptor 1).

[0052] FIG. 4 shows an example of the state of the groove 1b formed on the peripheral surface 1a of the photoreceptor 1. As shown in FIG. 4, each groove 1b is an annular groove extending in the circumferential direction on the peripheral surface 1a of the photoreceptor 1, and is formed so as to be arranged at intervals in the busbar direction of the peripheral surface 1a. That is, the peripheral surface 1a has a configuration in which a flat portion 1c where the groove 1b is not formed and the groove 1b are alternately formed in the busbar direction. Note that the region where the groove 1b is formed on the peripheral surface 1a only needs to include at least the region where the cleaning blade 51 abuts, and does not necessarily need to be formed over the entire longitudinal direction of the peripheral surface 1a.

[0053] As described in the above publication, the grooves 1b are not limited to a configuration in which they are formed to extend in the same direction as the circumferential direction as shown in FIG. 4. For example, the grooves 1b may be formed at an angle of 10° with respect to the circumferential direction. Alternatively, the grooves 1b may be formed at angles of ±30° with respect to the circumferential direction, with grooves 1b at different angles intersecting each other. In this embodiment, the term "substantially circumferential direction" includes both a completely circumferential direction and a nearly circumferential direction, and the nearly circumferential direction specifically refers to a direction at an angle of less than ±60° with respect to the circumferential direction.

[0054] Next, a polishing method for polishing the surface of the photoreceptor 1 will be described. FIG. 5 is a schematic diagram of a polishing device for polishing the surface of the photoreceptor 1. The polishing sheet 40 is taken up in the direction of the arrow by a take-up mechanism (not shown). The photoreceptor 1 rotates in the direction of the arrow. The backup roller 39 rotates in the direction of the arrow. Regarding the polishing conditions, a polishing sheet manufactured by Riken Corundum Co., Ltd. (product name: GC#3000, base layer thickness: 75 μm) was used as the polishing sheet 40. A urethane roller (outer diameter: 50 mm) with a hardness of 20° was used as the backup roller 39. The penetration depth was 2.5 mm, the sheet feed rate was 200 to 400 mm / s, and the feed direction of the polishing sheet 40 was the same as the rotation direction of the photoreceptor 1. Polishing was performed for 5 to 30 seconds. The surface roughness of the photoreceptor 1 after polishing was measured using a surface roughness measuring instrument (product name: SE700, SMB-9, manufactured by Kosaka Laboratory Co., Ltd.) under the following conditions. Measurements were taken in the longitudinal direction of the photoreceptor 1 at positions 30, 110, and 185 mm from the top of the coating. After rotating the photoreceptor 1 120° forward, measurements were taken again at positions 30, 110, and 185 mm from the top of the coating. After rotating the photoreceptor 1 120° forward, measurements were taken again in the same manner, for a total of nine measurements. The measurement conditions were: measurement length: 2.5 mm, cutoff value: 0.8 mm, feed speed: 0.1 mm / s, filter characteristics: 2CR, and leveling: linear (full range). In this example, the surface of the photoreceptor 1 was roughened, but roughening is not required.

[0055] <Toner composition> Next, the composition of the toner t will be further described.

[0056] In this embodiment, the toner t is an inorganic particle-added toner in which inorganic silicon is externally added to the base particles (toner particles) to ensure fluidity and improve charging performance. The toner t used in this embodiment is a non-magnetic, single-component, particle-polymerized toner with a negative charging polarity and an average particle size of 7 μm.

[0057] 6, metal soap 45c is added to inorganic silicon 45b to reduce the coefficient of friction on the surface of photoreceptor 1. Discharge products are inherently highly sticky and increase the coefficient of friction on the surface of photoreceptor 1, but by supplying metal soap 45c to the surface of photoreceptor 1, adhesion of discharge products to the surface of photoreceptor 1 can be suppressed, thereby suppressing an increase in the coefficient of friction.

[0058] Metal soap 45c is a general term for salts of long-chain fatty acids and metals other than sodium and potassium. Specific examples include metal salts of fatty acids such as stearic acid, myristic acid, lauric acid, ricinoleic acid, and octylic acid with metals such as lithium, magnesium, calcium, barium, and zinc. In Example 1, zinc stearate is externally added as metal soap 45c. However, the type of metal soap 45c is not limited to this, and other suitable metals include lead stearate, cadmium stearate, barium stearate, calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, zinc laurate, and zinc myristate. At least one of these may be selected.

[0059] The amount of metal soap 45c added externally is preferably 0.6 wt% or less. The more the amount added externally, the more effective it is in suppressing adhesion of discharge products to the photoreceptor 1, but if added excessively, the fluidity of the toner decreases, resulting in lower image density in the latter half of the image. This is a phenomenon known as solid image tracking degradation, in which tracking decreases as the image approaches the trailing edge of the recording material when outputting a solid black image. On the other hand, the amount of metal soap 45c added externally is preferably 0.05 wt% or more. If the amount is too small, the effect of the metal soap 45c is less likely to be realized.

[0060] The average particle size of the metal soap 45c is preferably 0.15 μm or more and 2.0 μm or less. If the average particle size of the metal soap 45c is smaller than 0.15 μm, it becomes difficult to apply the metal soap 45c to the surface of the photoreceptor 1. This becomes particularly noticeable when the surface of the photoreceptor 1 has grooves, as described below. On the other hand, if the particle size is larger than 2.0 μm, the metal soap 45c cannot pass through the toner regulation member 43 in the developing unit 4 and is left behind in the developing chamber 46, making it difficult to supply the metal soap 45c to the surface of the photoreceptor 1. Hereinafter, the toner base particles 45a and the external additives 45b and 45c are collectively referred to as the toner.

[0061] The method for measuring the average particle size of metal soap 45c will be described. 10 mL of ethanol was added to 0.5 g of metal soap 45c, and ultrasonic dispersion was performed for 5 minutes using an ultrasonic disperser manufactured by Nippon Seiki Co., Ltd. Next, ethanol was circulated as the measurement solvent. The resulting dispersion of metal soap 45c was then added to a Microtrac laser diffraction / scattering particle size distribution analyzer (SPA type) manufactured by Nikkiso Co., Ltd. until the DV (diffracted light intensity) value, which is a value related to the integrated value of the scattered light intensity of the particles, reached 0.6 to 0.8. The particle size distribution in this state was then measured, and the median diameter obtained as the cumulative median diameter, which is the 50% diameter, was taken as the average particle size.

[0062] The metal soap 45c having the above average particle size may be produced, for example, by a double decomposition method in which an aqueous solution of a fatty acid salt and an aqueous solution or dispersion of an inorganic metal salt are reacted with each other.

[0063] In Example 1, zinc stearate having an average particle size of 0.60 μm was used. The zinc stearate as the metal soap 45c is attached to the toner particles by being charged with a polarity opposite to that of the toner particles, and is supplied onto the photoreceptor 1 during non-image formation.

[0064] Next, a method for producing toner particles will be described.

[0065] The toner particles can be produced by a known method, such as a kneading and pulverization method or a wet production method. From the viewpoint of uniform particle size and shape controllability, the wet production method is preferred. Further, the wet production method can be a suspension polymerization method, a dissolution suspension method, an emulsion polymerization aggregation method, an emulsion aggregation method, or the like.

[0066] In this example, a suspension polymerization method was employed. In the suspension polymerization method, first, a polymerizable monomer for producing a binder resin and, if necessary, other additives such as a colorant are uniformly dissolved or dispersed using a disperser such as a ball mill or an ultrasonic disperser to prepare a polymerizable monomer composition. This process is called the polymerizable monomer composition preparation process. At this time, if necessary, a multifunctional monomer, a chain transfer agent, a wax or charge control agent as a mold release agent, a plasticizer, and the like can be appropriately added. Suitable examples of polymerizable monomers in the suspension polymerization method include the vinyl polymerizable monomers shown below.

[0067] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, and p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, and dibutyl phosphate. acrylic polymerizable monomers such as ethyl acrylate and 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

[0068] Next, the polymerizable monomer composition is added to a previously prepared aqueous medium, and droplets of the polymerizable monomer composition are formed into the desired toner particle size using a stirrer or disperser with high shear force. This process is called the granulation process. It is preferable that the aqueous medium used in the granulation process contains a dispersion stabilizer in order to control the particle size of the toner particles, sharpen the particle size distribution, and prevent the toner particles from coalescing during the production process. Dispersion stabilizers are generally broadly classified into polymers that exert repulsive forces due to steric hindrance and poorly water-soluble inorganic compounds that stabilize dispersion through electrostatic repulsive forces. Fine particles of poorly water-soluble inorganic compounds are preferably used because they dissolve in acids or alkalis and can be easily removed by washing with acids or alkalis after polymerization.

[0069] As the dispersion stabilizer of the poorly water-soluble inorganic compound, one containing any of magnesium, calcium, barium, zinc, aluminum, and phosphorus is preferably used. It is more preferable that one of magnesium, calcium, aluminum, and phosphorus is contained. Specific examples include the following.

[0070] Magnesium phosphate, tricalcium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, hydroxyapatide.

[0071] The dispersion stabilizer may be used in combination with an organic compound such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, or starch. These dispersion stabilizers are preferably used in an amount of 0.01 to 2.00 parts by mass per 100 parts by mass of the polymerizable monomer.

[0072] Furthermore, to refine the dispersion stabilizer, a surfactant may be used in an amount of 0.001 to 0.1 parts by mass per 100 parts by mass of the polymerizable monomer. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and calcium oleate are preferably used.

[0073] After or during the granulation step, the temperature is preferably set to 50°C or higher and 90°C or lower to polymerize the polymerizable monomers contained in the polymerizable monomer composition, thereby obtaining a toner particle dispersion. This step is called the polymerization step. In the polymerization step, stirring is preferably performed so that the temperature distribution in the container is uniform. When a polymerization initiator is added, it can be added at any timing and for any required time. In addition, the temperature may be increased in the latter half of the polymerization reaction in order to obtain a desired molecular weight distribution. Furthermore, in order to remove unreacted polymerizable monomers, by-products, etc. from the system, a portion of the aqueous medium may be distilled off in the latter half of the reaction or after completion of the reaction. The distillation step can be performed under normal pressure or reduced pressure.

[0074] In general, the polymerization initiator used in the suspension polymerization method is an oil-soluble initiator, for example, the following:

[0075] azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), and 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile; and peroxide initiators such as acetylcyclohexylsulfonyl peroxide, diisopropyl peroxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide, acetyl peroxide, tert-butyl peroxy-2-ethylhexanoate, benzoyl peroxide, tert-butyl peroxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxypivalate, and cumene hydroperoxide.

[0076] The polymerization initiator may be used in combination with a water-soluble initiator, if necessary. Examples thereof include the following.

[0077] Ammonium persulfate, potassium persulfate, 2,2'-azobis(N,N'-dimethyleneisobutyromidine) hydrochloride, 2,2'-azobis(2-aminodinopropane) hydrochloride, azobis(isobutylamidine) hydrochloride, sodium 2,2'-azobisisobutyronitrile sulfonate, ferrous sulfate, or hydrogen peroxide.

[0078] These polymerization initiators can be used alone or in combination of two or more, and in order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor, etc. can also be added.

[0079] The toner t may contain an organosilicon polymer, and the organosilicon polymer may have 1 to 3 carbon atoms directly bonded to the silicon atom. 3 / 2 Here, R may be a hydrocarbon group having 1 to 6 carbon atoms, or R may be a hydrocarbon group having 1 to 3 carbon atoms.

[0080] The amount of inorganic silica transferred by washing was controlled by using a Henschel mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) as the surface modification device and changing the external addition conditions, namely, the amount of external additive added, the rotation speed (circumferential speed) of the blade tips, and the time (hours) for which the blades rotated. Table 1 below shows the external addition conditions for toner T in this example. Details of the surface modification device and the external addition conditions, namely, the peripheral speed and time of the surface modification device, are as described in JP 2016-38591 A. Furthermore, 0.20 wt% of zinc stearate was externally added to toner T used in this example.

[0081] [Table 1]

[0082] <Lubricant composition> The lubricant applied to the developing roller 41 at the time of shipping the cartridge is inorganic particle-added toner t, as shown in FIG. 6, with an average particle size of 7 μm. However, the type of lubricant is not limited to the inorganic particle-added toner t described above, and silicone resin or the like may also be used. Furthermore, it is not necessary to apply a lubricant to the surface of the developing roller 41.

[0083] <Requirements and overview of the toner supply sequence> In the first embodiment, a toner supply sequence operation (toner purge operation) is executed when a new process cartridge 7 is installed in the image forming apparatus 100. An outline of the toner supply sequence will be described with reference to FIG.

[0084] FIG. 7 is a flowchart showing the operation of discharging the toner on the developing roller when the process cartridge 7 is new.

[0085] For example, when the image forming apparatus 100 is turned on or the cartridge replacement panel is opened or closed, and the apparatus is put into an operable (standby ON) state (S1), the control unit 202 starts an operation to determine whether to execute the toner supply sequence (S2).

[0086] First, the control unit 202 communicates with the memory m1 installed in the process cartridge 7 through the memory communication unit 222, and reads information related to the usage amount of the process cartridge 7 (S3). Here, the memory m1 is arranged on the photosensitive unit 8 side, but it may also be arranged on the developing unit 4 side.

[0087] Thereafter, the control unit 202 determines whether or not a new cartridge is included based on the information relating to the amount of use of the process cartridges 7 (S4).

[0088] If a new cartridge is not included (NO in S4), the control unit 202 controls the toner supply sequence not to be executed, and the process proceeds to the image forming process (S6).

[0089] If the controller 202 determines in step S4 that a new cartridge is included (YES in step S4), it executes a toner supply sequence (described later) (step S5). After the toner supply sequence is completed, the process proceeds to the image formation process (step S6).

[0090] In the initial stages of use of the process cartridge 7, the coefficient of friction on the surface of the photoreceptor 1 is high, and it is desirable to quickly and proactively supply metal soap 45c to the surface of the photoreceptor 1 to reduce the coefficient of friction. At the contact point P6 where the photoreceptor 1 and cleaning blade 51 come into contact, a cleaning-blocking layer made of external additives has not yet been sufficiently formed, and cleaning performance is unstable. Therefore, special care must be taken when supplying toner to the surface of the photoreceptor 1 and sending the toner to the contact point P6. In particular, it has been found that when the surface of the photoreceptor 1 is roughened as employed in this embodiment, it is difficult for a blocking layer to form in the nip area.

[0091] Therefore, in the first embodiment, driving is started under high voltage conditions and driving conditions for image formation so that the potential difference formed between the supply roller 42 and the developing roller 41, which causes an electrostatic force to act on the metal soap 45c in the direction from the supply roller 42 to the developing roller 41, is reduced. Then, laser irradiation is performed on the photosensitive member 1 to supply a fixed amount of toner. The voltages applied to each component during the toner supply sequence are set to Vd = -500V, Vdc = -350V, and Vrs = -400V.

[0092] In the first embodiment, the timing for executing the toner supply sequence operation is described as being when the toner is new, but the timing is not limited to this. The toner supply sequence operation may be executed at a timing designated by the user, at a timing when it is determined that the torque during driving is high, or at a timing when an image defect such as uneven density or poor cleaning occurs.

[0093] <Details of the toner supply pattern during the toner supply sequence> Here, the discharge pattern of the toner image discharged onto the photosensitive member 1 will be described.

[0094] FIG. 8 is a timing chart when the exposure unit 3 is controlled to form a toner supply pattern with laser light during a toner supply operation as a toner supply sequence.

[0095] At the initial installation of the cartridge, in the contact portion P6 formed between the photoreceptor 1 and the cleaning blade 51, the cleaning prevention layer made of an external additive or the like is not yet sufficiently formed, and the cleaning performance is unstable. Therefore, it is not desirable to select a pattern that supplies a large amount of toner to the contact portion P6. That is, it is desirable to control the laser beam so that it becomes an ejection pattern that can supply a small amount at a time and an amount sufficient to form the blocking layer on the surface of the photoreceptor 1. Specifically, in order to appropriately form the cleaning prevention layer, leveling rotation for a certain period is required after toner is supplied to the contact portion P6. Therefore, this embodiment is characterized in that a leveling section is provided in which toner is discharged in small amounts and toner is not discharged for a certain period. Further, in this embodiment, after discharging a small amount of toner, a repetitive operation of providing a leveling section in which toner is not discharged for a certain period is required. Therefore, as shown in Fig. 8(a), the pattern of the toner image formed on the surface of the photoreceptor 1 repeats a uniform line pattern in the longitudinal direction a certain number of times. By forming this pattern on the surface of the photoreceptor 1 and supplying toner, a small amount and the required amount are supplied. In this embodiment, the nip width of the nip formed in the contact portion P6 between the photoreceptor 1 and the cleaning blade 51 is 100 μm.

[0096] In Example 1, there are a development (purge) width A (first pattern, third pattern) and a non-development (purge) width B (second pattern, fourth pattern) in the circumferential direction of the rotation direction (circumferential direction) of the photoreceptor 1, and toner is discharged so as to be repeated a plurality of times with the relationship of A < B. Here, the non-development width B corresponds to the above-mentioned leveling section. The control unit 202 controls so that the development width A = 1 mm, the non-development width B = 9 mm, the number of repetitions = 5 times, and the laser beam amount = 0.40 μJ / cm 2 At this time, the toner t developed on the exposure surface corresponding to the development width A exposed with the laser beam amount = 0.40 μJ / cm formed on the surface of the photoreceptor 1 is 0.40 mg / cm on the surface of the development roller 41. 2 で露光された現像幅Aに対応する露光面に現像されるトナーtは、現像ローラ41の表面に0.40mg / cm 2The toner t is carried in an amount of 100% from the developing roller 41 toward the photosensitive member 1. In this embodiment, the toner supply operation PS is set to 91 mm / sec, which is a low speed mode. Therefore, the peripheral speed ratio of the developing roller 41 to the rotation speed of the photosensitive member 1 is 90%, and the toner t is carried in an amount of 1 cm. 2 0.36 mg of toner t is developed per development width. In this embodiment, the development opening width in the direction of the rotation axis of the development roller 41 (the maximum width that can supply toner t to the surface of the development roller 41) is 220 mm. The maximum width that can be exposed by the exposure unit 3 is set to a width that allows exposure to an area outside the above 220 mm. In this embodiment, the first pattern corresponding to the development width A is formed uniformly in the longitudinal direction. This allows toner to be supplied uniformly in the longitudinal direction to the contact portion P6 between the photosensitive member 1 and the cleaning blade 51. Of course, a configuration in which the above pattern is formed in only a portion of the longitudinal direction is also acceptable.

[0097] When the photoconductor 1 and the developing roller 41 are rotating, the area of ​​the photoconductor 1 that faces the developing roller 41 at the developing portion P3 is defined as the first area. The area of ​​the developing roller 41 that faces the first area, and the area of ​​the photoconductor 1 that faces the developing roller 41 at the developing portion P3 after the developing roller 41 has made one rotation, is defined as the second area. The area of ​​the photoconductor 1 between the first area and the second area in the direction of rotation of the photoconductor 1 is defined as the third area. A diagram illustrating the definitions of the areas is shown in FIG. 9.

[0098] The toner supply pattern used when performing the toner supply operation will be described in detail later.

[0099] The following first, second, third, and fourth patterns are formed in the third region, i.e., the region of the photosensitive member 1 corresponding to one rotation of the developing roller 41. That is, the following first, second, third, and fourth patterns are formed in the region of the photosensitive member 1 corresponding to the outer diameter of the developing roller 41, φ12×π×(1 / (90 / 100))=41.9 mm (90 is the ratio of the peripheral speed of the developing roller 41 to the rotational speed of the photosensitive member 1).

[0100] In this embodiment, the outer diameter of the photoconductor 1 is φ24, so the outer circumferential length of the photoconductor 1 is φ24 × π = 75.4 mm. The 41.9 mm corresponding to one rotation of the developing roller 41 corresponds to approximately 55% of one rotation of the photoconductor 1. The first pattern is the development width A, which is a pattern partially exposed by the exposure unit 3. The second pattern is the non-development width B, which is a pattern not exposed after the first pattern in the rotation direction. The third pattern is the second development width A, which is a pattern partially exposed by the exposure unit after the second pattern in the rotation direction. The fourth pattern is the second non-development width B, which is a pattern not exposed after the third pattern in the rotation direction. The control unit 202 controls the formation of a toner supply pattern consisting of the first pattern, second pattern, third pattern, and fourth pattern. Here, the toner supply pattern is configured so that the length of the second pattern is longer than the length of the first pattern in the rotation direction. The fourth pattern is also configured so that the length of the fourth pattern is longer than the length of the third pattern in the rotation direction. In particular, in this embodiment, the first pattern and the second pattern are formed repeatedly, i.e., the first pattern and the third pattern are the same pattern, and the second pattern and the fourth pattern are the same pattern.

[0101] Instead of not exposing the second and fourth patterns, non-developed areas may be formed by exposing them with a smaller amount of exposure than the amount of exposure used to expose the first pattern. Furthermore, if the toner supply section and the leveling section are configured as described above, the toner supply section may not be formed by exposure, but rather, toner may be developed on the surface potential Vd of the photoconductor 1 formed by the charging roller 2. Specifically, the control unit 202 sets the development voltage so that its absolute value is greater than Vd. This creates a potential difference between the development roller 41 and the photoconductor 1 such that the negatively charged toner t moves from the surface of the development roller 41 to which the development voltage is applied to the surface of the photoconductor 1 on which the surface potential Vd is formed.

[0102] In this embodiment, the surface of the developing roller 41 carries a toner t containing inorganic particles as a lubricant. The controller 202 reads information about the amount of toner used in the process cartridge 7 and controls the toner supply operation to be performed only when the cartridge is new. Therefore, when the process cartridge 7 is initially installed in the image forming apparatus 100, it is necessary to prevent the photosensitive member 1 and the cleaning blade 51 from continuing to rotate in a state of contact with each other under high torque. To achieve this, it is necessary to quickly and effectively deliver the lubricant to the contact portion P6 between the photosensitive member 1 and the cleaning blade 51. Therefore, the toner supply operation must be performed for at least one rotation of the developing roller 41. In this embodiment, the amount is set so that a portion of the toner supply pattern is included within the area corresponding to the third area.

[0103] Furthermore, in this embodiment, when the process cartridge 7 is not in the start-of-use state, the control unit 202 controls the process cartridge 7 to execute a second toner supply operation that is different from the first toner supply operation described above. The second toner supply operation is executed using a second toner supply pattern that is different from the first toner supply pattern described above. In the second toner supply operation, the development width A formed on the surface of the photosensitive member 1 is 12.6 mm. The development width A in the second toner supply operation is preferably approximately 10 to 20 mm. The toner supply pattern in the second toner supply operation is not a repeating pattern, but is an operation that is completed in one supply.

[0104] The first toner supply operation is performed in the early stages of cartridge use, repeatedly supplying and leveling toner to provide lubrication to the contact point P6 between the photoreceptor 1 and the cleaning blade 51. The amount of toner supplied at one time is controlled to a minimum so as to prevent cleaning defects and form a blocking layer. Meanwhile, the second toner supply operation is performed after the cartridge has been used to a certain extent. For example, the second toner supply operation is performed during a post-rotation operation after an image forming operation or during a paper-interval operation between consecutive image forming operations. When the second toner supply operation is performed, a blocking layer made of toner and external additives is formed at the contact point P6 between the photoreceptor 1 and the cleaning blade 51. Because the second toner supply operation is performed to maintain the blocking layer, more toner is supplied than in the first toner supply operation. In other words, the amount of toner supplied to contact portion P6 by the first toner supply pattern according to the first pattern formed on the surface of photoconductor 1 is set to be less than the amount of toner supplied to contact portion P6 by the second toner supply pattern formed on the surface of photoconductor 1. This means that the second toner supply operation supplies more toner in one operation than the first toner supply operation. Furthermore, the amount of toner supplied to contact portion P6 by the first toner supply pattern is set to be less than the amount of toner supplied to contact portion P6 by the second toner supply pattern formed on the surface of photoconductor 1. This means that the total amount of toner supplied in one toner purge operation is greater in the second toner supply operation than in the first toner supply operation. By setting the above conditions, it is possible to use the toner supply operation appropriately depending on the situation.

[0105] Furthermore, when performing the first toner supply operation, the control unit 202 controls the photoconductor 1 to rotate at a first rotational speed, and when performing the second toner supply operation, the control unit 202 controls the photoconductor 1 to rotate at a second rotational speed faster than the first rotational speed. By relatively slowing down the speed of the first toner supply operation, the objective is to improve the tracking of the cleaning blade 51 with respect to the photoconductor 1 and reduce the amount of toner supplied per unit time. In other words, by reducing the momentum of the toner, a condition is created where cleaning by the cleaning blade 51 is easier. In this embodiment, the rotational speed of the photoconductor 1 during the second toner supply operation is 321 mm / sec, which is the speed in normal mode. On the other hand, the rotational speed of the photoconductor 1 during the first toner supply operation is 91 mm / sec in low-speed mode, in which the rotational speed of the photoconductor 1 is slower than in normal mode.

[0106] Furthermore, in this embodiment, the intermediate transfer belt 31 can be brought into contact with and separated from each photoconductor 1 by a belt contact / separation mechanism 90 (FIG. 3). In this embodiment, the belt contact / separation mechanism 90 separates the intermediate transfer belt 31 from the photoconductor 1 by moving the primary transfer roller 32 away from the photoconductor 1. The controller 202 also moves the primary transfer roller 32 toward the photoconductor 1 to bring the intermediate transfer belt 31 into contact with the photoconductor 1. When performing the first toner supply operation, the controller 202 controls the intermediate transfer belt 31 to be in contact with the photoconductor 1, and when performing the second toner supply operation, the controller 202 controls the intermediate transfer belt 31 to be separated from the photoconductor 1. When performing the first toner supply operation, the controller 202 controls the transfer voltage as follows: The absolute value of the transfer voltage applied to the transfer roller 32 in the first toner supply operation is smaller than the absolute value of the transfer voltage applied in the image forming operation. Then, the transfer contrast, which is the potential difference between the transfer voltage and the surface potential of the photosensitive member 1 at the transfer portion P4, is made smaller than the transfer contrast during the image forming operation. The reason for the above control regarding transfer will be explained below.

[0107] The first toner supply operation is typically performed during the initial use of the process cartridge 7, as described above. In this case, contact between the photosensitive member 1 and the cleaning blade 51 is highly unstable. This instability can cause rotational fluctuations in the photosensitive member 1, or cleaning defects due to the unstable contact state of the cleaning blade 51. Therefore, in this embodiment, during the first toner supply operation, the transfer roller 32 is moved toward the photosensitive member 1 to bring the intermediate transfer belt 31 into contact with the photosensitive member 1. This contact between the intermediate transfer belt 31 and the photosensitive member 1 stabilizes the rotation of the photosensitive member 1, thereby suppressing the instability. Furthermore, during the first toner supply operation, the intermediate transfer belt 31 is brought into contact with the photosensitive member 1 to rotate the photosensitive member 1, so that the toner t transferred from the developing roller 41 to the surface of the developed photosensitive member 1 passes through the transfer portion P4. At the transfer portion P4, a transfer voltage is applied that minimizes the transfer of the lubricant containing toner t (in this embodiment, toner t with inorganic particle additives) to the intermediate transfer belt 31. In this embodiment, a transfer voltage of a polarity opposite to the normal polarity of the toner is applied to the transfer roller 32. This transfer voltage is set to be larger toward the normal polarity, i.e., negative polarity, than the transfer voltage in the image forming operation, with the polarity opposite to the normal polarity of the toner as a reference. Alternatively, the transfer voltage may be turned off, or a voltage of the same polarity as the normal polarity of the toner may be applied in the first place. This forms an electric field at the transfer portion P4 that makes it more difficult for the toner t to move toward the intermediate transfer belt 31 than during the image forming operation, making it possible to supply the lubricant containing toner t to the contact portion P6 between the photoconductor 1 and the cleaning blade 51.

[0108] In this way, by setting the conditions for executing the toner supply operation, the amount of toner per unit time that enters the contact point P6 between the photosensitive member 1 and the cleaning blade 51 can be reduced, and cleaning performance can be maintained while supplying components that form a cleaning prevention layer.

[0109] <Verification of effectiveness> In the above-described Example 1, after executing the toner supply sequence for a new product, a comparative verification was carried out between Example 1 and the comparative example by observing the amount of toner adhering to the charging roller 2. The verification was carried out using a cartridge filled with 400 g of toner under low temperature and low humidity conditions (temperature 15°C, humidity 10%), which are conditions that make cleaning defects likely to occur.

[0110] The toner supply pattern was set as follows:

[0111] Comparative Example 1 has purge width A (first pattern) = 5 mm, non-purge width (second pattern) = 0 mm, and repetition count = 1. This corresponds to control in which the length of the first pattern is shortened with respect to the second toner supply operation.

[0112] In Comparative Example 2, purge width A (first pattern)=1 mm, non-purge width (second pattern)=1 mm, and number of repetitions=5 times.

[0113] In Example 1-1, purge width A (first pattern) = 1 mm, non-purge width (second pattern) = 9 mm, number of repetitions = 5 times.

[0114] In Example 1-2, purge width A (first pattern) = 2.5 mm, non-purge width (second pattern) = 9 mm, number of repetitions = 2 times.

[0115] In both cases, the toner supply amount was the same (5 mm) for comparison.

[0116] <Verification results> Table 2 shows the verification results.

[0117] [Table 2]

[0118] In Comparative Example 1, when the charging roller 2 was checked after the toner supply sequence ended, a large amount of toner t adhered, resulting in charging defects due to contamination of the charging roller, and numerous vertical streaks occurred. In Comparative Example 2, although it was less severe than Comparative Example 1, toner t adhered to the charging roller 2, resulting in charging defects due to contamination of the charging roller, and numerous vertical streaks occurred.

[0119] On the other hand, in Example 1-1 and Example 1-2, no image defects occurred. Consider the reasons why the effects were demonstrated with the configurations of Example 1-1 and Example 1-2.

[0120] As conditions for performing the toner supply operation, it is necessary to quickly and effectively send the above lubricant to the contact portion P6 between the photoreceptor 1 and the cleaning blade 51. Therefore, in this embodiment, at least a toner supply pattern is formed within the region corresponding to the third region. It is configured such that the length of the second pattern, which is the non-purge portion, is longer than the length of the first pattern, which is the purge portion in the rotational direction, and the first pattern and the second pattern are repeatedly formed.

[0121] First, in Example 1-1, the first pattern A is set to 1 mm and the second pattern B is set to 9 mm. In this embodiment, it is preferable that A is set to less than 50% of B, and it is more preferable that the ratio of B to the toner supply pattern is set to 70% or more. That is, it is preferable that A < B and (B / (A + B)) × 100 ≧ 70% is satisfied. Here, 70% is called the "smoothing ratio". A larger smoothing ratio means that the smoothing time is longer. Since the smoothing ratio in Example 1-1 is 90%, it can be seen that a sufficient smoothing effect is obtained. On the other hand, the smoothing ratio of Comparative Example 1 is 0%, and the smoothing ratio of Comparative Example 2 is 50%. From the magnitude of the smoothing ratio, the level of Comparative Example 2 is better than that of Comparative Example 1, but both are insufficient.

[0122] Also, there is a preferable range for the length of A. In this embodiment, it is preferably within the range of 0.5 mm to 3.0 mm. In this embodiment, the nip width in the rotational direction of the photoreceptor 1 formed at the contact portion P6 between the photoreceptor 1 and the cleaning blade 51 is 100 μm, and the amount of toner t carried on the developing roller 41 is 0.40 mg / cm 2 is. Here, the developing width A is set to 1 mm as the first pattern, and the peripheral speed ratio of the developing roller 41 to the photoreceptor 1 in the first toner supply operation is 90%. Therefore, when the toner purge operation for 1 mm is performed, the amount of toner entering the nip portion is 0.036 mg / (1 mm×1 cm). In the configuration of this embodiment, it has been experimentally found that the amount of toner that can be tolerated by one toner supply in the nip portion per unit nip (per 1 cm in the longitudinal width) is about 0.11 mg, which corresponds to a developing width A of about 3.0 mm. Therefore, in Comparative Example 1, since A is 5 mm, it can be said that the level of toner adhesion was poor. Also, if the amount of toner supplied at one time is too small, the time of the toner supply operation may become long, or the effect may not be obtained at all. Therefore, a suitable range should be defined according to the configuration. Although it will be described after Example 2, once the blocking layer starts to be formed in the nip portion, the above-mentioned tolerable amount of toner tends to increase.

[0123] In Example 1-2, there was slightly more toner adhesion than in Example 1-1, but the image quality was at a level with no problem. This is also because, for the same reason as in Example 1-1, A < B and (B / (A + B))×100 ≧ 70% is satisfied. Since the leveling ratio in Example 1-2 is 78%, it can be seen that the effect is obtained.

[0124] From this verification, as described above, it was found that by appropriately supplying a small amount of toner at a time rather than supplying a large amount of toner at once, the toner that becomes the cleaning blocking layer can be supplied at a low load. As in Example 1, after performing the toner supply and then performing the leveling rotation for a certain period, the toner that becomes the cleaning blocking layer can be supplied at a low load to the contact portion P6 between the photoreceptor 1 and the cleaning blade 51.

[0125] This embodiment has the following configuration.

[0126] The image forming apparatus includes a photoconductor 1 as a rotatable image carrier and an exposure unit 3 that exposes the surface of the photoconductor 1 to light to form an electrostatic latent image on the surface of the photoconductor 1. The image forming apparatus includes a developing roller 41 as a rotatable developer carrier that supplies toner to the surface of the photoconductor 1 at a developing portion P3 to develop the electrostatic latent image into a toner image. The image forming apparatus includes a cleaning blade 51 as a cleaning member that contacts the photoconductor 1 to form a contact portion P6 and removes toner adhering to the surface of the photoconductor 1 at the contact portion P6. The image forming apparatus includes a controller 202 that controls the rotation of the photoconductor 1 and the developing roller 41 and the exposure unit 3 to control the following operations: i) an image forming operation in which a toner image is formed on a recording material; and ii) a toner supplying operation, which is an operation different from the image forming operation, in which toner is transferred from the developing roller 41 to the photoconductor 1 and supplied to the contact portion P6. When the photoconductor 1 and the developing roller 41 are rotating, the area of ​​the photoconductor 1 facing the developing roller 41 at the developing portion P3 is designated as a first area. The area of ​​the photoconductor 1 facing the developing roller 41 in the developing unit P3 after the area of ​​the developing roller 41 facing the first area has made one rotation is defined as the second area. Furthermore, the area of ​​the photoconductor 1 between the first area and the second area in the rotation direction of the photoconductor 1 is defined as the third area. When performing the toner supply operation, the controller 202 controls the exposure unit 3 to form the following pattern in the third area: a first pattern, a portion of which is exposed by the exposure unit 3, and a second pattern, a portion of which is not exposed or is exposed with an exposure amount smaller than that of the first pattern. The toner supply pattern is configured such that the length of the second pattern is longer than the length of the first pattern in the rotation direction, and the first and second patterns are repeatedly formed.

[0127] Furthermore, the length of the third pattern in the rotation direction is shorter than the length of the first pattern in the rotation direction.

[0128] The control unit 202 further includes a memory m1 that stores information regarding the toner usage status, and executes a toner supply operation using the toner supply pattern based on the information stored in the memory m1. The information is for determining whether the toner is in a start-of-use state, and if the information indicates that the toner is in a start-of-use state, the control unit 202 executes a toner supply operation using the toner supply pattern. If the information indicates that the toner is not in a start-of-use state, the control unit 202 controls to execute a second toner supply operation that is different from the first toner supply operation using the toner supply pattern. The second toner supply operation is executed using a second toner supply pattern that is different from the first toner supply pattern that is the toner supply pattern. The amount of toner supplied to the contact portion P6 by the first toner supply pattern according to the first pattern formed on the surface of the photoconductor 1 is less than the amount of toner supplied to the contact portion P6 by the second toner supply pattern formed on the surface of the photoconductor 1. The amount of toner supplied to contact point P6 by the first toner supply pattern formed on the surface of photoreceptor 1 is less than the amount of toner supplied to contact point P6 by the second toner supply pattern formed on the surface of photoreceptor 1. The length of the first pattern in the direction of the rotation axis of photoreceptor 1 is a length that allows image formation during image formation operation. The first pattern is formed uniformly in the direction of the rotation axis of photoreceptor 1.

[0129] The image forming apparatus includes an intermediate transfer belt 31 that contacts the photoreceptor 1 to form a transfer portion P4 and transfers a toner image formed on the surface of the photoreceptor 1 to a recording material P at the transfer portion P4. The image forming apparatus further includes a belt contact / separation mechanism 90 that can perform a contact operation to bring the intermediate transfer belt 31 into contact with the photoreceptor 1 and a separation operation to separate the intermediate transfer belt 31 from the photoreceptor 1. The control unit 202 controls the intermediate transfer belt 31 to be in contact with the photoreceptor 1 when performing a first toner supply operation. Furthermore, the control unit 202 controls the intermediate transfer belt 31 to be separated from the photoreceptor 1 when performing a second toner supply operation. The image forming apparatus further includes a primary transfer power supply 73 that applies a transfer voltage to the intermediate transfer belt 31, i.e., the transfer roller 32. The potential difference between the transfer voltage and the surface potential formed on the surface of the photoreceptor 1 at the transfer portion P4 is defined as transfer contrast. The control unit 202 reduces the transfer contrast of the first toner supply operation to be smaller than the transfer contrast of the image forming operation. The control unit 202 controls the absolute value of the transfer voltage of the first toner supply operation to be smaller than the absolute value of the transfer voltage of the image forming operation, or controls the transfer voltage to be OFF. The control unit 202 may also control the first toner supply operation to apply a transfer voltage of opposite polarity to the polarity of the transfer voltage of the image forming operation. When performing the first toner supply operation, the control unit 202 controls the photoconductor 1 to rotate at a first rotation speed, and when performing the second toner supply operation, the control unit 202 controls the photoconductor 1 to rotate at a second rotation speed that is faster than the first rotation speed.

[0130] By adopting the above-described configuration, it is possible to suppress the occurrence of image defects due to poor cleaning.

[0131] Example 2 Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the image forming apparatus of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements that are the same as or correspond to those of the image forming apparatus of embodiment 1 are given the same reference numerals as those of embodiment 1, and detailed explanations thereof will be omitted.

[0132] <Outline of this Example> In the second embodiment, the toner supply pattern is changed in the same configuration as in the first embodiment.

[0133] Specifically, as shown in FIG. 8(b), the non-purge width B is fixed, and the purge width A is reduced as the number of times increases. That is, the first time, there is a circumferential purge width A that is developed and a circumferential non-purge width B that is not developed, the second time there is a circumferential purge width C that is developed and a non-purge width B, and the third time there is a circumferential purge width E that is developed and a non-purge width B. In general, the toner t is discharged so that the relationship between the circumferential purge width developed in the nth time and the circumferential purge width developed in the n+1th time satisfies n>n+1. This example is compared with Comparative Example 2, which was compared in Example 1.

[0134] The toner supply pattern in Example 2 is as follows:

[0135] In Example 2, the purge width was 2.5 mm / 1.5 mm / 1 mm, the non-purge width B was 9 mm, and the number of repetitions was 3.

[0136] The toner supply amount was the same in both cases (5 mm).

[0137] <Verification result 2> Table 3 shows the verification results.

[0138] [Table 3]

[0139] In Comparative Example 2, as described in Example 1, the smoothing rotation distance after the first purge was insufficient, so the second purge entered the contact point P6 of the cleaning blade 51 before the cleaning prevention layer was formed, causing the toner to slip through.

[0140] In Example 2, toner adhesion to the charging roller due to poor cleaning did not occur. This is because the cleaning member was able to withstand the first purge amount, and the subsequent long smoothing rotation of the non-purged area formed a sufficient blocking layer, and furthermore, the purge amount was reduced from the second time onwards, making cleaning easier.

[0141] This test showed that a cleaning prevention layer can be formed if the non-purge distance (the distance of the smoothing rotation) is longer than the purge distance by a certain distance, and that cleaning becomes easier by reducing the amount of purge from the second time onwards. Furthermore, the time required to form the prevention layer can be shortened compared to the configuration of Example 1-1, and the test results were better than those of Example 1-2.

[0142] The configuration of this embodiment has the following features.

[0143] The image forming apparatus includes a photoconductor 1 as a rotatable image carrier and an exposure unit 3 that exposes the surface of the photoconductor 1 to light to form an electrostatic latent image on the surface of the photoconductor 1. The image forming apparatus includes a developing roller 41 as a rotatable developer carrier that supplies toner to the surface of the photoconductor 1 at a developing portion P3 to develop the electrostatic latent image into a toner image. The image forming apparatus includes a cleaning blade 51 as a cleaning member that contacts the photoconductor 1 to form a contact portion P6 and removes toner adhering to the surface of the photoconductor 1 at the contact portion P6. The image forming apparatus includes a controller 202 that controls the rotation of the photoconductor 1 and the developing roller 41 and the exposure unit 3 to control the following operations: i) an image forming operation in which a toner image is formed on a recording material; and ii) a toner supplying operation, which is an operation different from the image forming operation, in which toner is transferred from the developing roller 41 to the photoconductor 1 and supplied to the contact portion P6. When the photoconductor 1 and the developing roller 41 are rotating, the area of ​​the photoconductor 1 facing the developing roller 41 at the developing portion P3 is designated as a first area. The area of ​​the photoconductor 1 that faces the developing roller 41 in the developing unit P3 after the area of ​​the developing roller 41 facing the first area has made one rotation is defined as the second area. Furthermore, the area of ​​the photoconductor 1 between the first area and the second area in the rotation direction of the photoconductor 1 is defined as the third area. When performing the toner supply operation, the control unit 202 forms a toner supply pattern consisting of the following first, second, third, and fourth patterns in the third area. The first pattern is a pattern in which a portion is exposed by the exposure unit 3. The second pattern is a pattern in which a portion is not exposed after the first pattern in the rotation direction of the photoconductor 1. The third pattern is a pattern in which a portion is exposed by the exposure unit after the second pattern in the rotation direction of the photoconductor 1. The fourth pattern is a pattern in which a portion is not exposed after the third pattern in the rotation direction of the photoconductor 1. These toner supply patterns are configured so that the second pattern is longer than the first pattern in the rotation direction of the photosensitive member 1, and the fourth pattern is longer than the third pattern in the rotation direction of the photosensitive member 1. The length of the third pattern in the rotation direction of the photosensitive member 1 is shorter than the length of the first pattern in the rotation direction.

[0144] By having the configuration as described above, the occurrence of image defects associated with cleaning failures can be more effectively suppressed.

[0145] (Example 3) In Example 3, the toner supply pattern is further changed in the same configuration as in Example 1. In Example 2, it was characterized in that the non-purge width B was fixed and the purge width A was decreased as the rotation number advanced. Specifically, in Example 3, as shown in FIG. 8(c), the control of the first pattern and subsequent patterns of the toner supply pattern is changed. There are regions of the circumferential purge width C developed as the third pattern and the non-purge width D in the circumferential direction not developed as the fourth pattern, and the relationship is C < D in terms of length. Thereafter, there are regions of the circumferential purge width E developed as the fifth pattern and the non-purge width F in the circumferential direction not developed as the sixth pattern, and the relationship is E < F. Thus, the control unit 202 is controlled such that the relationship between the circumferential purge width developed at the n-th development and the circumferential purge width developed at the (n + 1)-th development is n > n + 1. Further, the toner t is discharged such that the relationship between the non-purge width in the circumferential direction not developed at the n-th time and the non-purge width in the circumferential direction not developed at the (n + 1)-th time is n > n + 1. That is, the lengths of the purge portion and the non-purge portion are always such that the purge portion < non-purge portion, and even if both widths are shortened each time it is repeated, improvement in the charging roller contamination due to cleaning failures is compared with Example 1 and Example 2. Two types of the configuration of Example 3 and one type of the modified example of Example 3 were compared simultaneously.

[0146] In Comparative Example 3, the purge widths A / C / E = 2.5 mm / 1.5 mm / 1 mm, the non-purge widths B / D / F = 9 mm / 1 mm / 1 mm, and the number of repetitions = 3 times.

[0147] In Example 3-1, the purge widths A / C / E = 2.5 mm / 1.5 mm / 1 mm, the non-purge widths B / D / F = 9 mm / 3 mm / 1 mm, and the number of repetitions = 3 times.

[0148] Example 3-2 has a purge width of A / C / E = 2.5 mm / 1.5 mm / 1 mm, a non-purge width of B / D / F = 9 mm / 7 mm / 5 mm, and a repetition count of 3 times.

[0149] Modification 1 has a purge width of A / C / E = 2.5 mm / 1 mm / 1.5 mm, a non-purge width of B / D / F = 9 mm / 5 mm / 7 mm, and a repetition count of 3 times. In both cases, the toner supply amount was the same (5 mm).

[0150] <Verification Result 3> Table 4 shows the verification results.

[0151]

Table 4

[0152] In Comparative Example 3, since the leveling rotation distance after the second purge was insufficient, the third purge entered the contact portion P6 of the cleaning blade 51 before the cleaning prevention layer was formed, and it is considered that the toner passed through.

[0153] On the other hand, in Example 3-1, no cleaning failure occurred. This is because a certain degree of prevention layer was formed at the nip portion in the first pass, and the leveling rotation distance after the second purge could be ensured due to the relationship of C < D, indicating that the cleaning prevention layer could be formed more effectively than in Comparative Example 3. And further, due to the relationship of E < F, the third purge could also clean to some extent. Here, in Example 3-1, the leveling ratio was 70% in the first pass, but was below 70% in the second and third passes. Since the foundation of the prevention layer could be constructed in the first pass, the conditions for the second and third passes were slightly relaxed. Therefore, in the toner supply operation after the first pass, as long as C < D and E < F, even if the leveling ratio is smaller than that in the first pass, the occurrence of problems can be suppressed.

[0154] Furthermore, even in Example 3-2, toner adhesion to the charging roller 2 due to poor cleaning did not occur. Example 3-2 is a more suitable condition than Example 3-1, ensuring a uniform ratio of 70% for all the first, second, and third times. As a result, as toner supply conditions to the nip portion, the distances of the non-purged portions after the first, second, and third purges are sufficient, and in all cases, a sufficient cleaning prevention layer is formed. However, the rotation time of the photoreceptor 1 is slightly longer than that of Example 3-1.

[0155] Subsequently, Variant 1 will be considered. The difference between Example 3-2 and Variant 1 is that the conditions for the second time and the third time are swapped. Therefore, in Variant 1, C < E, and it is characteristic that the toner purge executed later in the toner supply operation has a larger supply toner amount. Even in Variant 1, no image defects occurred, and a suitable blocking layer could be formed. This indicates that the relationship A < C is maintained from the first time to the second time, suggesting that the formation of the blocking layer has progressed to some extent at this point. And even if the supply amount increases from the second time to the third time, it is presumed that the penetration of the toner can be suppressed. As long as the conditions are advantageous for the formation of the blocking layer, they can also be applied under the conditions of Variant 1. However, the relationships A < B, C < D, and E < F need to be satisfied.

[0156] Therefore, by performing the above control, in addition to the effects of Example 1, it is possible to further reduce the extra rotation of the process cartridge 7 and suppress the wear of the photoreceptor 1 and the deterioration of the toner t.

[0157] The configuration of this embodiment has the following characteristics.

[0158] The image forming apparatus includes a photoconductor 1 as a rotatable image carrier and an exposure unit 3 that exposes the surface of the photoconductor 1 to light to form an electrostatic latent image on the surface of the photoconductor 1. The image forming apparatus includes a developing roller 41 as a rotatable developer carrier that supplies toner to the surface of the photoconductor 1 at a developing portion P3 to develop the electrostatic latent image into a toner image. The image forming apparatus includes a cleaning blade 51 as a cleaning member that contacts the photoconductor 1 to form a contact portion P6 and removes toner adhering to the surface of the photoconductor 1 at the contact portion P6. The image forming apparatus includes a controller 202 that controls the rotation of the photoconductor 1 and the developing roller 41 and the exposure unit 3 to control the following operations: i) an image forming operation in which a toner image is formed on a recording material; and ii) a toner supplying operation, which is an operation different from the image forming operation, in which toner is transferred from the developing roller 41 to the photoconductor 1 and supplied to the contact portion P6. When the photoconductor 1 and the developing roller 41 are rotating, the area of ​​the photoconductor 1 facing the developing roller 41 at the developing portion P3 is designated as a first area. The area of ​​the photoconductor 1 that faces the developing roller 41 in the developing unit P3 after the area of ​​the developing roller 41 facing the first area has made one rotation is defined as the second area. Furthermore, the area of ​​the photoconductor 1 between the first area and the second area in the rotation direction of the photoconductor 1 is defined as the third area. When performing the toner supply operation, the control unit 202 forms a toner supply pattern consisting of the following first, second, third, and fourth patterns in the third area. The first pattern is a pattern in which a portion is exposed by the exposure unit 3. The second pattern is a pattern in which a portion is not exposed after the first pattern in the rotation direction of the photoconductor 1. The third pattern is a pattern in which a portion is exposed by the exposure unit after the second pattern in the rotation direction of the photoconductor 1. The fourth pattern is a pattern in which a portion is not exposed after the third pattern in the rotation direction of the photoconductor 1. These toner supply patterns are configured so that the length of the second pattern is longer than the length of the first pattern in the rotation direction of the photosensitive member 1, and the length of the fourth pattern is longer than the length of the third pattern in the rotation direction of the photosensitive member 1. The length of the fourth pattern in the rotation direction of the photosensitive member 1 is shorter than the length of the second pattern in the rotation direction.

[0159] By adopting the above-described configuration, it is possible to more effectively suppress the occurrence of image defects due to poor cleaning.

[0160] In this example, the toner supply amount was set to 5 mm, but this is not limiting and it may be necessary to increase or decrease the toner supply amount depending on the configuration of the image forming apparatus. However, the same effect can be obtained with the combinations described in this example.

[0161] Furthermore, although the embodiment has been described for an inline color image forming apparatus in which the image forming units S are arranged in a straight line, it can also be applied to a rotary color image forming apparatus. The contents of this embodiment may also be applied to a monochrome image forming apparatus with a single image forming unit S. In that case, a configuration using a recording material transport member may be used instead of a configuration using the intermediate transfer belt 31, or a configuration in which a toner image is transferred directly to the recording material P without using a recording material transport member may be adopted.

[0162] Although the process cartridge 7 is used, a dual-component cartridge in which the photosensitive unit 8 and the developing unit 4 are each mountable to the image forming apparatus 100 may also be used. In this case, the toner supply operation of this embodiment may be performed when the photosensitive unit 8 is new, or when the developing unit 4 is new. The former is because, as described in this embodiment, no blocking layer is formed at the contact point P6 between the cleaning blade 51 and the photosensitive element 1. The latter is because, even if a blocking layer is formed, if the developing unit 4 is new and new toner t is supplied to the contact point P6, the blocking layer may be destroyed by the new toner t, which has a high charge. Therefore, the toner supply operation of this embodiment may also be performed when the developing unit 4 is new. Alternatively, the photosensitive unit 8 may be configured so that only the photosensitive unit 8 is attached to the image forming apparatus and cannot be removed.

[0163] The disclosure of this embodiment includes the following configuration.

[0164] (Configuration 1) a rotatable image carrier; an exposure unit for exposing the surface of the image carrier to light to form an electrostatic latent image on the surface of the image carrier; a rotatable developer carrier in a developing section that supplies toner to a surface of the image carrier to develop the electrostatic latent image into a toner image; a cleaning member that comes into contact with the image carrier to form a contact portion and removes toner adhering to the surface of the image carrier at the contact portion; By rotating the image carrier and the developer carrier and controlling the exposure unit, i) an image forming operation for forming the toner image on a recording material; ii) a toner supplying operation, which is an operation different from the image forming operation, in which the toner is moved from the developer carrier to the image carrier and supplied to the contact portion; a control unit that controls the above so that the above can be executed; In an image forming apparatus comprising: When the image carrier and the developer carrier are rotating, a region of the image carrier that faces the developer carrier in the developing unit is defined as a first region, a region of the image carrier that faces the developer carrier in the developing unit after the region of the developer carrier that faces the first region has made one rotation is defined as a second region, and a region of the image carrier between the first region and the second region in the rotation direction of the image carrier is defined as a third region. When the control unit executes the toner supply operation, controlling the exposure unit to form, in the third region, a toner supply pattern that is formed from a first pattern that is partially exposed by the exposure unit and a second pattern that is partially not exposed or is exposed with an exposure amount that is smaller than the exposure amount for exposing the first pattern; The toner supply pattern is configured so that the length of the second pattern is longer than the length of the first pattern in the rotation direction, and the first pattern and the second pattern are repeatedly formed.

[0165] (Configuration 2) a rotatable image carrier; an exposure unit for exposing the surface of the image carrier to light to form an electrostatic latent image on the surface of the image carrier; a rotatable developer carrier in a developing section that supplies toner to a surface of the image carrier to develop the electrostatic latent image into a toner image; a cleaning member that comes into contact with the image carrier to form a contact portion and removes toner adhering to the surface of the image carrier at the contact portion; By rotating the image carrier and the developer carrier and controlling the exposure unit, i) an image forming operation for forming the toner image on a recording material; ii) a toner supplying operation, which is an operation different from the image forming operation, in which the toner is moved from the developer carrier to the image carrier and supplied to the contact portion; a control unit that controls the above so that the above can be executed; In an image forming apparatus comprising: When the image carrier and the developer carrier are rotating, a region of the image carrier that faces the developer carrier in the developing unit is defined as a first region, a region of the image carrier that faces the developer carrier in the developing unit after the region of the developer carrier that faces the first region has made one rotation is defined as a second region, and a region of the image carrier between the first region and the second region in the rotation direction of the image carrier is defined as a third region. When the control unit executes the toner supply operation, control to form, in the third region, a toner supply pattern formed from a first pattern, a second pattern, a portion of which is not exposed after the first pattern in the rotation direction or is exposed with an exposure amount smaller than that for exposing the first pattern; a third pattern, a portion of which is exposed by the exposure unit after the second pattern in the rotation direction; and a fourth pattern, a fourth pattern, a portion of which is not exposed after the third pattern in the rotation direction or is exposed with an exposure amount smaller than that for exposing the third pattern; An image forming apparatus characterized in that the toner supply pattern is configured so that the length of the second pattern is longer than the length of the first pattern in the rotation direction, and so that the length of the fourth pattern is longer than the length of the third pattern in the rotation direction.

[0166] (Configuration 3) 3. The image forming apparatus according to claim 2, wherein the length of the third pattern in the rotation direction is shorter than the length of the first pattern in the rotation direction.

[0167] (Configuration 4) The image forming apparatus according to configuration 2 or 3, wherein the length of the fourth pattern in the rotation direction is shorter than the length of the second pattern in the rotation direction.

[0168] (Configuration 5) The toner cartridge further includes a memory for storing information about the toner usage status, 3. The image forming apparatus according to claim 1, wherein the control unit executes the toner supply operation according to the toner supply pattern based on the information stored in the memory.

[0169] (Configuration 6) The information is information for determining whether the toner is in a start-of-use state, 6. The image forming apparatus according to configuration 5, wherein when the information indicates that the toner is in a start-of-use state, the toner supply operation is executed according to the toner supply pattern.

[0170] (Configuration 7) the control unit, when the information indicates that the toner is not in a start-of-use state, performs control to execute a second toner supply operation different from a first toner supply operation that is the toner supply operation according to the toner supply pattern; 7. The image forming apparatus according to configuration 6, wherein the second toner supply operation is performed using a second toner supply pattern that is different from the first toner supply pattern that is the toner supply pattern.

[0171] (Configuration 8) The image forming apparatus of configuration 7, characterized in that the amount of toner supplied to the contact portion by the first toner supply pattern according to the first pattern formed on the surface of the image carrier is less than the amount of toner supplied to the contact portion by the second toner supply pattern formed on the surface of the image carrier.

[0172] (Configuration 9) The image forming apparatus of configuration 7, characterized in that the amount of toner supplied to the contact portion by the first toner supply pattern formed on the surface of the image carrier is less than the amount of toner supplied to the contact portion by the second toner supply pattern formed on the surface of the image carrier.

[0173] (Configuration 10) 3. The image forming apparatus according to configuration 1 or 2, wherein the length of the first pattern in the direction of the rotation axis of the image carrier is a length that allows image formation in the image forming operation.

[0174] (Configuration 11) 11. The image forming apparatus according to claim 10, wherein the first pattern is formed uniformly in the direction of the rotation axis of the image carrier.

[0175] (Configuration 12) a transfer member that contacts the image carrier to form a transfer section and transfers the toner image formed on the surface of the image carrier to a transfer material in the transfer section; a contact / separation mechanism that can perform a contact operation that brings the transfer member into contact with the image carrier and a separation operation that separates the transfer member from the image carrier, The image forming apparatus according to configuration 7, wherein the control unit controls the transfer member to be in contact with the image carrier when performing the first toner supply operation, and controls the transfer member to be separated from the image carrier when performing the second toner supply operation.

[0176] (Configuration 13) a transfer voltage applying unit that applies a transfer voltage to the transfer member; When the potential difference formed between the transfer voltage and the surface potential formed on the surface of the image carrier in the transfer portion is defined as a transfer contrast, 13. The image forming apparatus according to claim 12, wherein the control unit makes the transfer contrast of the first toner supplying operation smaller than the transfer contrast of the image forming operation.

[0177] (Configuration 14) The image forming apparatus according to configuration 13, characterized in that the control unit controls the absolute value of the transfer voltage of the first toner supply operation to be smaller than the absolute value of the transfer voltage of the image forming operation, or controls the transfer voltage to be OFF.

[0178] (Configuration 15) 14. The image forming apparatus according to claim 13, wherein the control unit controls the transfer voltage to be applied in the first toner supply operation, the transfer voltage having a polarity opposite to that of the transfer voltage in the image forming operation.

[0179] (Configuration 16) The image forming apparatus according to configuration 7, wherein the control unit controls the image carrier to rotate at a first rotational speed when performing the first toner supply operation, and controls the image carrier to rotate at a second rotational speed that is faster than the first rotational speed when performing the second toner supply operation. [Explanation of symbols]

[0180] 1 photoreceptor 2 Charging roller 3 Exposure Unit 7 Process cartridge 41 Developing roller 42 Supply roller 100 Image forming device 202 Control section

Claims

1. a rotatable image carrier; an exposure unit for exposing the surface of the image carrier to light to form an electrostatic latent image on the surface of the image carrier; a rotatable developer carrier in a developing section that supplies toner to a surface of the image carrier to develop the electrostatic latent image into a toner image; a cleaning member that comes into contact with the image carrier to form a contact portion and removes toner adhering to the surface of the image carrier at the contact portion; a memory for storing information for determining whether the toner is in a ready-to-use state; By rotating the image carrier and the developer carrier and controlling the exposure unit, i) an image forming operation for forming the toner image on a recording material; ii) a toner supplying operation, which is an operation different from the image forming operation, in which the toner is moved from the developer carrier to the image carrier and supplied to the contact portion; a control unit that controls the above so that the above can be executed; In an image forming apparatus comprising: When the image carrier and the developer carrier are rotating, a region of the image carrier that faces the developer carrier in the developing unit is defined as a first region, a region of the image carrier that faces the developer carrier in the developing unit after the region of the developer carrier that faces the first region has made one rotation is defined as a second region, and a region of the image carrier between the first region and the second region in the rotation direction of the image carrier is defined as a third region. When the control unit executes the toner supply operation, controlling the exposure unit to form a toner supply pattern in the third region, the toner supply pattern being composed of a first pattern that is partially exposed by the exposure unit and a second pattern that is partially not exposed or is exposed with an exposure amount that is smaller than the exposure amount for exposing the first pattern; the toner supply pattern is configured such that a length of the second pattern is longer than a length of the first pattern in the rotation direction, and the first pattern and the second pattern are repeatedly formed, The control unit is configured to: iii) if the information indicates that the toner is in a ready-to-use state, executing a first toner supply operation according to a first toner supply pattern; iv) When the information indicates that the toner is not in a ready-to-use state, the image forming apparatus is controlled to execute a second toner supply operation that is different from the first toner supply operation using the first toner supply pattern, the second toner supply operation using a second toner supply pattern that is different from the first toner supply pattern.

2. a rotatable image carrier; an exposure unit for exposing the surface of the image carrier to light to form an electrostatic latent image on the surface of the image carrier; a rotatable developer carrier in a developing section that supplies toner to a surface of the image carrier to develop the electrostatic latent image into a toner image; a cleaning member that comes into contact with the image carrier to form a contact portion and removes toner adhering to the surface of the image carrier at the contact portion; By rotating the image carrier and the developer carrier and controlling the exposure unit, i) an image forming operation for forming the toner image on a recording material; ii) a toner supplying operation, which is an operation different from the image forming operation, in which the toner is moved from the developer carrier to the image carrier and supplied to the contact portion; a control unit that controls the above so that the above can be executed; In an image forming apparatus comprising: When the image carrier and the developer carrier are rotating, a region of the image carrier that faces the developer carrier in the developing unit is defined as a first region, a region of the image carrier that faces the developer carrier in the developing unit after the region of the developer carrier that faces the first region has made one rotation is defined as a second region, and a region of the image carrier between the first region and the second region in the rotation direction of the image carrier is defined as a third region. When the control unit executes the toner supply operation, control to form, in the third region, a toner supply pattern formed from a first pattern, a second pattern, a portion of which is not exposed after the first pattern in the rotation direction or is exposed with an exposure amount smaller than that for exposing the first pattern, a third pattern, a portion of which is exposed by the exposure unit after the second pattern in the rotation direction, and a fourth pattern, a fourth pattern, a portion of which is not exposed after the third pattern in the rotation direction or is exposed with an exposure amount smaller than that for exposing the third pattern, the toner supply pattern is configured such that the length of the second pattern is longer than the length of the first pattern in the rotation direction, and the length of the fourth pattern is longer than the length of the third pattern in the rotation direction, An image forming apparatus characterized in that the length of the third pattern in the rotational direction is shorter than the length of the first pattern in the rotational direction, or the length of the fourth pattern in the rotational direction is shorter than the length of the second pattern in the rotational direction.

3. The toner cartridge further includes a memory for storing information about the toner usage status, 3. The image forming apparatus according to claim 2, wherein the control unit executes the toner supplying operation according to the toner supplying pattern based on the information stored in the memory.

4. The information is information for determining whether the toner is in a start-of-use state, 4. The image forming apparatus according to claim 3, wherein when the information indicates that the toner is in a ready-to-use state, the toner supply operation is executed according to the toner supply pattern.

5. the control unit, when the information indicates that the toner is not in a start-of-use state, performs control to execute a second toner supply operation different from a first toner supply operation that is the toner supply operation according to the toner supply pattern; 5. The image forming apparatus according to claim 4, wherein the second toner supply operation is performed using a second toner supply pattern that is different from the first toner supply pattern that is the toner supply pattern.

6. 6. The image forming apparatus according to claim 5, wherein the amount of toner supplied to the contact portion by the first toner supply pattern according to the first pattern formed on the surface of the image carrier is less than the amount of toner supplied to the contact portion by the second toner supply pattern formed on the surface of the image carrier.

7. 6. The image forming apparatus according to claim 5, wherein the amount of toner supplied to the contact portion by the first toner supply pattern formed on the surface of the image carrier is less than the amount of toner supplied to the contact portion by the second toner supply pattern formed on the surface of the image carrier.

8. 3. The image forming apparatus according to claim 1, wherein the length of the first pattern in the direction of the rotation axis of the image carrier is a length that allows image formation in the image forming operation.

9. 9. The image forming apparatus according to claim 8, wherein the first pattern is formed uniformly in the direction of the rotation axis of the image carrier.

10. a transfer member that contacts the image carrier to form a transfer section and transfers the toner image formed on the surface of the image carrier to a transfer material in the transfer section; a contact / separation mechanism that can perform a contact operation that brings the transfer member into contact with the image carrier and a separation operation that separates the transfer member from the image carrier, The image forming apparatus according to claim 5, characterized in that the control unit controls the transfer member to be in contact with the image carrier when performing the first toner supply operation, and controls the transfer member to be spaced from the image carrier when performing the second toner supply operation.

11. a transfer voltage applying unit that applies a transfer voltage to the transfer member; When the potential difference formed between the transfer voltage and the surface potential formed on the surface of the image carrier in the transfer portion is defined as a transfer contrast, 11. The image forming apparatus according to claim 10, wherein the control unit makes the transfer contrast of the first toner supplying operation smaller than the transfer contrast of the image forming operation.

12. 12. The image forming apparatus according to claim 11, wherein the control unit controls the transfer voltage so that the absolute value of the transfer voltage in the first toner supply operation is smaller than the absolute value of the transfer voltage in the image forming operation, or controls the transfer voltage to be OFF.

13. 12. The image forming apparatus according to claim 11, wherein the control unit controls the transfer voltage to be applied in the first toner supplying operation, the transfer voltage having a polarity opposite to that of the transfer voltage in the image forming operation.

14. 6. The image forming apparatus according to claim 5, wherein the control unit controls the image carrier to rotate at a first rotational speed when performing the first toner supply operation, and controls the image carrier to rotate at a second rotational speed faster than the first rotational speed when performing the second toner supply operation.

Images