Image formation apparatus

Abstract

To suppress the occurrence of abnormal sound, while reducing deterioration in productivity of an image formation apparatus.SOLUTION: An image formation apparatus includes: a first cartridge storing a first toner; a second cartridge storing a second toner; an intermediate transfer body; and detection means for detecting whether the first cartridge fitted to a device body is new or not. Further, the image formation apparatus includes a control unit which, in a case where the detection means detects that the first cartridge fitted to the device body is new, executes a first operation of toner supply for supplying the second toner from the second cartridge to a first contact part of the first cartridge, and which is capable of executing a second operation of toner supply in which the first toner is supplied to the first contact part, and the second toner is supplied to a second contact part of the second cartridge.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] In an electrophotographic image forming apparatus that forms an image on a recording material, an electrostatic latent image formed on the surface of an image carrier is developed with toner (developer) on a developer carrier to form an image. The toner image on the image carrier is then transferred onto a transfer material such as an intermediate transfer body. Meanwhile, toner that has not been transferred and remains on the image carrier is removed from the image carrier by a cleaning member.

[0003] As a cleaning member, a counter-type blade cleaning configuration that has a simple configuration and a high toner removal ability is widely used. In this configuration, a cleaning blade made of an elastic body is fixed to a container and supported at one end, and the other end is a free end that abuts against the peripheral surface of the image carrier. In addition, at the abutment position with the image carrier, the tip of the free end side of the cleaning blade is arranged in a state facing the upstream side of the moving direction of the image carrier surface (counter direction).

[0004] In such a configuration, if the frictional force between the image carrier and the cleaning blade increases, the stick-slip phenomenon of the cleaning blade may occur, which may cause abnormal noise. Patent Document 1 discloses a method for reducing the frictional force between the image carrier and the cleaning blade by using a toner having hemispherical protrusions made of an organosilicon polymer on the surface of a toner base particle of a predetermined size. The protrusions detach from the developer surface and enter the contact area between the image carrier and the cleaning blade, thereby reducing the frictional force. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-190713 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-mentioned configuration, it takes a certain amount of time for some of the protrusions to move from the surface of the toner base particle to the contact area between the image carrier and the cleaning blade. This is because the hemispherical protrusions on the surface of the toner base particle are linked to each other to form a network, which has the characteristic of being excellent in durability.

[0007] SUMMARY OF THE PRESENT EMBODIMENT In view of the above, an object of the present invention is to provide an image forming apparatus capable of suppressing a decrease in productivity. [Means for solving the problem]

[0008] In order to achieve the above object, an image forming apparatus according to the present invention comprises: A device body, a first cartridge including a first image carrier on whose surface an electrostatic latent image is formed, a first toner container for accommodating a first toner, a first toner carrier for carrying the first toner and developing the electrostatic latent image on the surface of the first image carrier into a toner image, and a first cleaning member for contacting the first image carrier to form a first contact portion, the first cartridge being detachably attached to the main body of the apparatus; a second image carrier on whose surface a toner image is formed; and a second toner storage container that stores a second toner. a second cartridge including a container, a second toner carrier that carries the second toner and develops the electrostatic latent image on the surface of the first image carrier into a toner image, and a second cleaning member that contacts the second image carrier to form a second contact portion, the second cartridge being detachably attached to the main body of the apparatus; an intermediate transfer body configured to be rotatable and onto which a toner image is transferred from the first image carrier and the second image carrier; a detection means for detecting whether the first cartridge attached to the main body of the apparatus is a new cartridge; Equipped with the first toner has toner particles containing toner base particles and an organosilicon polymer on the surface of the toner base particles, The organosilicon polymer has a structure represented by the following formula (1): the organosilicon polymer forms convex portions on the surfaces of the toner base particles, the second toner has a toner particle surface on which the convex portion is not formed and to which fine powder is externally added; The device is characterized in that, when the detection means detects that the first cartridge attached to the device main body is new, a control unit executes a first toner supply operation to supply the second toner from the second cartridge to the first contact portion of the first cartridge via the intermediate transfer body, and is equipped with a control unit capable of executing a second toner supply operation to supply the first toner to the first contact portion and the second toner to the second contact portion. R-SiO 3 / 2 (1) (In formula (1), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.) Effect of the Invention

[0009] According to the present invention, it is possible to provide an image forming apparatus capable of suppressing a decrease in productivity. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of an image forming apparatus according to a first embodiment. [Diagram 2] 1 is a schematic cross-sectional view of an image forming unit according to a first embodiment. [Diagram 3] FIG. 2 is a schematic diagram of a cross section of the toner according to Example 1 observed by STEM. [Figure 4] 4 is a schematic diagram showing a method for measuring protrusions of a toner according to Example 1. FIG. [Diagram 5] 4 is a schematic diagram showing a method for measuring protrusions of a toner according to Example 1. FIG. [Figure 6] 4 is a schematic diagram showing a method for measuring protrusions of a toner according to Example 1. FIG. [Figure 7] 2 is a block diagram showing an outline of a control mode of the image forming apparatus according to the first embodiment. FIG. [Figure 8] 4 is a schematic diagram of an initial installation operation according to the first embodiment. FIG. [Figure 9] 6A to 6C are explanatory diagrams of a toner supplying process in the initial installation operation according to the first embodiment. [Figure 10] 4 is a flowchart of a toner supplying operation according to the first embodiment. [Figure 11] FIG. 11 is a schematic diagram of an initial installation operation according to the second embodiment. [Figure 12] FIG. 11 is an explanatory diagram of a second initial toner supplying step of the initial installation operation according to the second embodiment. [Figure 13] 13A to 13C are explanatory diagrams of toner behavior during an initial installation operation according to the second embodiment. [Figure 14] 13 is an explanatory diagram of a toner supplying process in the initial installation operation according to the first modified example. FIG. [Figure 15] FIG. 11 is a schematic cross-sectional view of an image forming apparatus according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of an image forming apparatus according to the present invention will be described in more detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiment may be changed as appropriate depending on the configuration and various conditions of the apparatus to which the present invention is applied. In other words, the scope of the present invention is not limited to the following embodiment.

[0012] [Example 1] <Overall configuration of image forming apparatus and image forming operation> The overall configuration and image forming operation of an image forming apparatus 100 according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view of the image forming apparatus 100 according to the first embodiment. The image forming apparatus 100 according to the first embodiment is a tandem type laser beam printer employing an intermediate transfer method, capable of forming a full-color image using an electrophotographic method.

[0013] Image forming apparatus 100 has four image forming sections SY, SM, SC, and SK that form images of the colors yellow (Y), magenta (M), cyan (C), and black (K) as a plurality of image forming sections (image forming units) S. Elements having the same or corresponding functions or configurations for each color may be generally described by omitting the Y, M, C, or K at the end of the reference numeral indicating that the element is for one of the colors.

[0014] In the first embodiment, the image forming section S includes a photosensitive drum 1, a charging roller 2, an exposure device 3, a developing device 4, a primary transfer roller 5, a cleaning member 6, and the like, which will be described later.

[0015] The photosensitive drum 1, which serves as an image carrier on whose surface an electrostatic latent image is formed, is a rotatable drum-type (cylindrical) photosensitive member (electrophotographic photosensitive member). A driving force is transmitted from a drum driving motor (not shown) serving as a driving means to the photosensitive drum 1, and the photosensitive drum 1 is driven to rotate around its rotation shaft in the direction of the arrow shown in the figure (counterclockwise direction).

[0016] The charging roller 2 as a charging means is a roller-type charging member. The charging roller 2 uniformly charges the surface of the rotating photosensitive drum 1 to a predetermined potential of a predetermined polarity (negative polarity in the first embodiment).

[0017] The surface of the charged photosensitive drum 1 is scanned and exposed by an exposure device (exposure unit) 3 with a laser beam Ls corresponding to an image signal (image information) of a color component corresponding to each image forming section S, and an electrostatic latent image (electrostatic image) corresponding to the image signal is formed on the photosensitive drum 1. The image signal is input to the image forming apparatus 100 in response to a request from a user (operator), for example, from an image reading device (not shown) connected to the apparatus body 111 of the image forming apparatus 100. Alternatively, the image signal is input to the image forming apparatus 100 in response to a request from a host device (external device) (not shown), such as a personal computer, communicably connected to the apparatus body 111, for example.

[0018] Further, in the first embodiment, the exposure device 3 is configured as one unit common to each image forming section S, but may be provided for each image forming section S.

[0019] The electrostatic latent image formed on the photosensitive drum 1 is developed (visualized) by supplying toner 90 as a developer by the developing device 4 as a developing means, and a toner image (toner image, developer image) is formed on the photosensitive drum 1. In the first embodiment, the developer used is the toner 90, which is a non-magnetic one-component developer with a normal charging polarity (charging polarity for developing the electrostatic latent image) of negative polarity. That is, in the first embodiment, the developing device 4 performs development by a reversal development method in which the toner 90 charged to the same polarity as the charging polarity of the photosensitive drum 1 is attached to a portion (image portion, exposed portion) on the surface of the photosensitive drum 1 where the absolute value of the potential has been reduced by exposure after being uniformly charged. In the first embodiment, the charging polarity of the photosensitive drum 1 and the toner 90 to be attached is negative polarity.

[0020] An intermediate transfer belt 7, which is an endless belt serving as an intermediate transfer body, is disposed so as to face the four photosensitive drums 1. The intermediate transfer belt 7 is stretched around a driving roller 21, a tension roller 22, and a secondary transfer opposing roller 23 serving as a plurality of tension rollers, stretched with a predetermined tension, and configured to be rotatable. The intermediate transfer belt 7 rotates (circumferentially moves) in the direction of the arrow (clockwise direction) as the drive roller 21 is rotationally driven by a belt drive motor (not shown) which is an intermediate transfer body drive unit. The intermediate transfer belt 7 rotates at a rotational speed such that the moving speed (circumferential speed) of its surface (outer periphery) is substantially the same as the moving speed (circumferential speed) of the surface (outer periphery) of the photosensitive drum 1.

[0021] Primary transfer rollers 5Y, 5M, 5C, and 5K (first to fourth transfer members) are arranged on the inner circumferential surface side of the intermediate transfer belt 7 in correspondence with the photosensitive drums 1Y, 1M, 1C, and 1K (first to fourth image carriers). The primary transfer rollers 5 are roller-type primary transfer members (primary transfer means). The primary transfer rollers 5 are pressed against the photosensitive drums 1 via the intermediate transfer belt 7, and form a primary transfer portion (primary transfer nip) N1, which is a contact portion between the photosensitive drums 1 and the intermediate transfer belt 7.

[0022] The toner image formed on the photosensitive drum 1 is electrostatically transferred (primary transfer) onto the rotating intermediate transfer belt 7 as a transfer target by the action of the primary transfer roller 5 in the primary transfer section N1. At this time, a predetermined primary transfer voltage (primary transfer bias), which is a DC voltage of the opposite polarity to the normal charging polarity of the toner 90, is applied to the primary transfer roller 5 from a primary transfer power source 70 as a primary transfer voltage application means (primary transfer voltage application section). As a result, when forming a full-color image, for example, the toner images of each color of YMCK formed on each photosensitive drum 1 are transferred sequentially onto the intermediate transfer belt 7 so as to be superimposed on top of each other.

[0023] In the first embodiment, the primary transfer power supply 70 is configured as one power supply unit common to each image forming unit S. However, the primary transfer power supply 70 may be provided for each image forming unit S.

[0024] A secondary transfer roller 9 serving as a secondary transfer means (transfer member) is disposed at a position facing the secondary transfer opposing roller 23 on the outer peripheral surface side of the intermediate transfer belt 7. The secondary transfer roller 9 is a roller-type secondary transfer member. The secondary transfer roller 9 is pressed toward the secondary transfer opposing roller 23 via the intermediate transfer belt 7, and forms a secondary transfer portion (secondary transfer nip) N2 together with the intermediate transfer belt 7. Then, in the secondary transfer portion N2, which is the contact portion between the secondary transfer roller 9 and the intermediate transfer belt 7, a recording material P such as a recording paper or a plastic sheet serving as a transfer target is sandwiched and conveyed.

[0025] The toner image formed on the intermediate transfer belt 7 is transferred (secondary transfer) at the secondary transfer portion N2 by the action of the secondary transfer roller 9 onto the recording material P being conveyed while being sandwiched between the intermediate transfer belt 7 and the secondary transfer roller 9. At this time, a predetermined secondary transfer voltage (secondary transfer bias), which is a DC voltage of the opposite polarity to the normal charging polarity of the toner 90, is applied to the secondary transfer roller 9 from a secondary transfer power source 71 serving as a secondary transfer voltage application means (secondary transfer voltage application portion).

[0026] The recording material P is stored in a cassette 11 serving as a recording material storage section. The recording material P in the cassette 11 is separated one by one by a feed roller 12 serving as a feed member and sent out from the cassette 11. The recording material P is transported to the secondary transfer section N2 by a transport roller (registration roller) 13 serving as a transport member so as to be synchronized with the toner image on the intermediate transfer belt 7.

[0027] The recording material P onto which the toner image has been transferred is transported to a fixing device 10 serving as a fixing means. In the process of nipping and transporting the recording material P carrying an unfixed toner image between a pair of fixing rollers, the fixing device 10 pressurizes and heats the toner image on the recording material P to fix (melt and adhere) it onto the recording material P. The recording material P onto which the toner image has been fixed is discharged (output) as an image formed product onto a tray 14 serving as a discharge unit provided outside the apparatus main body 111 of the image forming apparatus 100.

[0028] On the other hand, the toner 90 remaining on the photosensitive drum 1 after the primary transfer (primary transfer residual toner) is removed from the photosensitive drum 1 and collected by a cleaning member 6 serving as an image carrier cleaning means.

[0029] Further, a conductive brush 15 is disposed on the outer peripheral surface side of the intermediate transfer belt 7. The conductive brush 15 is disposed downstream of the secondary transfer portion N2 and upstream of the primary transfer portion N1 (the most upstream primary transfer portion N1Y) in the rotation direction (movement direction of the surface) of the intermediate transfer belt 7. The toner 90 (secondary transfer residual toner) remaining on the intermediate transfer belt 7 after the secondary transfer is uniformly scattered by the conductive brush 15 and charged to a polarity opposite to the normal charging polarity of the toner 90. At this time, a DC voltage of a polarity opposite to the normal charging polarity of the toner 90 is applied to the conductive brush 15 from a conductive brush power source 72 as a conductive brush voltage application means (conductive brush voltage application portion). The secondary transfer residual toner charged to a polarity opposite to the normal charging polarity of the toner 90 is transferred to the photosensitive drum 1 at the primary transfer portion N1 and removed from the photosensitive drum 1 by a cleaning member 6 provided on the photosensitive drum 1 and collected.

[0030] In the first embodiment, in each image forming section S, the photosensitive drum 1, the charging roller 2 acting on the photosensitive drum 1 as a process means, the developing device 4, and the cleaning member 6 are integrated as a process cartridge 8. The process cartridge 8 is configured to be detachable from the device main body 111. The device main body 111 is a portion of the image forming apparatus 100 excluding the process cartridges 8. However, the image forming apparatus 100 is not limited to such a configuration. The image forming apparatus 100 may be configured, for example, such that the process cartridge 8 and the toner cartridge containing the toner 90 are detachable from the device main body 111 individually. The image forming apparatus 100 may also be configured, for example, such that the developing device 4 is a cartridge (developing cartridge) that is substantially detachable from the device main body 111 alone.

[0031] Note that the image forming apparatus 100 is configured so that it can form a monochromatic or multi-color image by using only one or some (not all) desired image forming units S.

[0032] <Process cartridge> 2 is a schematic cross-sectional view showing in more detail the configuration of the process cartridge 8 of Example 1. The process cartridge 8 is configured by integrating a photoconductor unit 16 including the photoconductor drum 1 and the like, and a developing device 4.

[0033] 2 is the posture of the process cartridge 8 when it is attached to the apparatus body 111 of the image forming apparatus 100 (when in use), and when describing the positional relationship and direction, etc. of each member of the process cartridge 8, the positional relationship and direction, etc. in this posture are shown. That is, the up-down direction on the paper in FIG. 2 corresponds to the vertical direction, and the left-right direction on the paper corresponds to the horizontal direction. Also, this arrangement is set on the assumption that the image forming apparatus 100 is installed on a horizontal surface as a normal installation state.

[0034] The photosensitive unit 16 has a cleaning frame 17 as a frame that supports various elements within the photosensitive unit 16. The photosensitive drum 1 is rotatably attached to the cleaning frame 17 via a bearing (not shown). The photosensitive drum 1 has a photosensitive layer in which an undercoat layer, a carrier generating layer, and a carrier transport layer, which are functional films, are coated in that order on an aluminum drum base. The photosensitive drum 1 is driven to rotate in the direction of the arrow A (counterclockwise direction) in the drawing around its rotation axis by a drum drive motor (not shown). In Example 1, the photosensitive drum 1 is a negatively charged organic photosensitive drum with a diameter of 20 mm, and its surface (outer periphery The moving speed (circumferential speed) of the surface (rotary surface) is, for example, 140 mm / sec.

[0035] The cleaning frame 17 has the charging roller 2 and the cleaning member 6 disposed therein so as to come into contact with the outer circumferential surface (surface) of the photosensitive drum 1.

[0036] The charging roller 2 is a conductive roller having a conductive rubber layer provided on a core metal. In the first embodiment, the charging roller 2 is disposed in contact with the surface of the photosensitive drum 1 with a predetermined pressure, and rotates in accordance with the rotation of the photosensitive drum 1. During image formation (charging process), a predetermined charging voltage (charging bias) is applied to the charging roller 2 from a charging power source (not shown) serving as a charging voltage application means (charging voltage application section). In the first embodiment, a DC voltage of, for example, -1150V is applied to the charging roller 2 during image formation (charging process), and the surface potential of the photosensitive drum 1 becomes approximately -500V.

[0037] The cleaning member 6 includes a support member 62 as a support for a metal substrate, and a cleaning blade 61 as an elastic body made of a thermosetting resin. The support member 62 is made of a metal sheet bent into an L-shape, with one plate portion fixed to the cleaning frame 17 by a fastener such as a screw, and the other plate portion extending in a direction substantially perpendicular to the one plate portion. In the first embodiment, the cleaning blade 61 is fixed to the tip of the plate portion on the side fixed to the cleaning frame 17. The cleaning blade 61 has one end fixed to the support member 62, and the other end, which is a free end, abuts against the surface of the photosensitive drum 1 with a predetermined pressure to form a cleaning nip N3, which is an abutment area (abutment portion) with the photosensitive drum 1. In the cleaning nip N3, the tip portion on the free end side of the cleaning blade 61 is provided so as to face the upstream side of the moving direction of the surface of the photosensitive drum 1 (counter direction). The primary transfer residual toner scraped off from the surface of the rotating photosensitive drum 1 by the cleaning blade 61 is contained in the cleaning frame 17 .

[0038] The developing device 4 has a rotatable developing roller 42 as a toner carrier (developing member), a rotatable supply roller 43 as a supply member, a regulating blade 44 as a regulating member, and a developing container (frame) 41 as a toner storage container that stores toner 90. The developing roller 42 contacts the surface of the photosensitive drum 1 to form a developing section, and supplies toner 90 charged to the normal charging polarity to the electrostatic latent image on the photosensitive drum 1 in the developing section.

[0039] The developing roller 42 and the supply roller 43 are each rotatably supported by the developer container 41. The developing roller 42 is rotated in the direction of the arrow B (clockwise direction) by a driving force transmitted from a developing drive motor (not shown) which is a developing drive unit as a driving means. Similarly, the supply roller 43 is rotated in the direction of the arrow C (clockwise direction) by a driving force transmitted from a developing drive motor (not shown). In the first embodiment, when the developing roller 42 is rotated, the supply roller 43 is also rotated. That is, the developing roller 42 is rotated so that the moving directions of the surfaces of the photosensitive drum 1 and the developing roller 42 are forward (same direction) at the facing portion (contact portion) with the photosensitive drum 1. Also, the supply roller 43 is rotated so that the moving directions of the surfaces of the developing roller 42 and the supply roller 43 are opposite to each other at the facing portion (contact portion) with the developing roller 42.

[0040] In the developing device 4, toner 90 is supplied to the surface of the developing roller 42 by a supply roller 43. The toner 90 held (carried) on the developing roller 42 is then thinned by a regulating blade 44, which regulates the layer thickness (thickness of the toner layer). The regulating blade 44 not only regulates the layer thickness of the toner 90 on the developing roller 42, but also imparts a predetermined charge to the toner 90 on the developing roller 42. The thinned toner 90 is transported to the contact portion with the photosensitive drum 1 as the developing roller 42 rotates, and is then transferred to the photosensitive drum 1. The electrostatic latent image formed on the surface is developed. Furthermore, toner 90 remaining on the developing roller 42 without being used for development is removed from the developing roller 42 at the contact portion with the supply roller 43. The toner 90 removed from the developing roller 42 is then stirred and mixed with the toner 90 in the developing container 41.

[0041] The developing roller 42 is configured such that a conductive elastic rubber layer having a predetermined volume resistance is provided on the outer periphery of a metal core, and the surface of the developing roller 42 has a predetermined surface roughness. The developing roller 42 may be a single-layer roller or a roller having a multi-layer structure. For example, a single-layer roller may be one in which an elastic layer is formed on a core from a rubber material such as silicone rubber, urethane rubber, or hydrin rubber. For example, a multi-layer roller may be one in which a surface layer is formed by coating the surface of the elastic layer similar to the above with silicone resin, urethane resin, polyamide resin, or fluororesin.

[0042] In the first embodiment, for example, when the image forming apparatus 100 stops operating, the developing roller 42 is stopped in a state in which it is separated from the photosensitive drum 1 by a developing contact / separation mechanism (not shown) (developing separated state). Also, in the first embodiment, the photosensitive drum 1 is rotated in response to the start of an image forming operation or the like. At the same time, the developing roller 42 is rotated in a state in which it is separated from the photosensitive drum 1 by the developing contact / separation mechanism (not shown). Then, at a predetermined timing, the developing contact / separation mechanism (not shown) operates to bring the developing roller 42 into contact with the photosensitive drum 1 at a predetermined contact width, and a developing operation or the like is performed.

[0043] The supply roller 43 is an elastic sponge roller having a foam layer formed of a foam having a predetermined electrical resistance value on the outer periphery of a metal core. The supply roller 43 is arranged so as to contact the developing roller 42 with a predetermined penetration amount. In the first embodiment, the supply roller 43 has a foam layer formed of urethane rubber, and the urethane rubber of the foam layer contains an ion conductive agent. In the first embodiment, the supply roller 43 is configured such that an ion conductive agent formed of a salt of a cation and an anion having a reactive functional group that reacts with an isocyanate group is chemically bonded to the urethane rubber of the foam layer via the reactive functional group. For example, the supply roller 43 having such a configuration can be manufactured by foaming and curing a urethane composition containing an ion conductive agent.

[0044] The regulating blade 44 is made of a plate-like elastic member having flexibility. The regulating blade 44 is a plate-like member having a substantially rectangular shape in a plan view, with a predetermined length in a longitudinal direction disposed substantially parallel to the rotation axis direction of the developing roller 42 and a lateral direction substantially perpendicular to the longitudinal direction. One end of the regulating blade 44 in the lateral direction is fixed to the developing container 41 and supported by a cantilever, and the other end in the lateral direction is a free end. The regulating blade 44 abuts against the surface (outer peripheral surface) of the developing roller 42 at a surface near the free end. The regulating blade 44 is disposed so as to contact the surface of the developing roller 42 at a position downstream of the opposing portion (contact portion) between the supply roller 43 and the developing roller 42 in the moving direction (rotation direction) of the surface of the developing roller 42. In the first embodiment, a SUS material is used as the elastic member of the regulating blade 44. In the first embodiment, the regulating blade 44 is provided so that its free end in the short side direction faces the upstream side of the moving direction of the surface of the developing roller 42 (counter direction).

[0045] During image formation (development operation), a predetermined DC voltage is applied to the developing roller 42, the supply roller 43, and the regulating blade 44. In the first embodiment, during image formation (development operation), a DC voltage of −350 V is applied to the developing roller 42 as a developing voltage (developing bias) by a developing power source (not shown) serving as a developing voltage application means (developing voltage application section). As a result, at the contact portion between the developing roller 42 and the photosensitive drum 1, the toner 90 on the developing roller 42, which is charged to the normal charging polarity, develops the electrostatic latent image formed on the surface of the photosensitive drum 1.

[0046] In addition, in the first embodiment, during image formation (development operation), a DC voltage of −450 V is applied as a supply voltage (supply bias) to the supply roller 43 by a supply power source (not shown) serving as a supply voltage application means (supply voltage application section). As a result, at the contact portion between the supply roller 43 and the development roller 42, the toner 90 charged to the normal charging polarity is urged (moved) from the supply roller 43 side to the development roller 42 side, and the supply of the toner 90 by the supply roller 43 can be stabilized.

[0047] In addition, in the first embodiment, during image formation (development), a DC voltage of −450 V is applied as a regulating voltage (regulating bias) to the regulating blade 44 by a regulating power source (not shown) serving as a regulating voltage application means (regulating voltage application section). As a result, at the contact portion between the regulating blade 44 and the developing roller 42, the toner 90 charged to the normal charging polarity is urged from the regulating blade 44 side to the developing roller 42 side, stabilizing the intake of the toner 90. Furthermore, the application of the electric charge to the toner 90 by the regulating blade 44 can be stabilized.

[0048] The voltages applied to the developing roller 42, the supply roller 43, and the regulating blade 44 are not limited to those described above. The potential difference between the supply roller 43 and the developing roller 42, and the potential difference between the regulating blade 44 and the developing roller 42 are appropriately set in accordance with the characteristics of each member. For example, the potential difference between the supply roller 43 and the developing roller 42, and the potential difference between the regulating blade 44 and the developing roller 42 may be the same potential.

[0049] As described above, the image forming apparatus 100 according to the first embodiment includes four process cartridges 8 (first, second, third, and fourth cartridges) that are configured similarly to one another. That is, the image forming apparatus 100 includes four photosensitive drums 1 (first, second, third, and fourth image carriers), four developing containers 41 (first, second, third, and fourth toner storage containers), and four developing rollers 42 (first, second, third, and fourth developing members). Furthermore, the image forming apparatus 100 includes four charging rollers (first, second, third, and fourth charging members) and four cleaning members (first, second, third, and fourth cleaning members).

[0050] In the first embodiment, two types of toner 90 are used in combination: toner 90a having protrusions containing an organosilicon polymer on the toner particle surface, and toner 90b having no protrusions. Toner 90a as the first toner and toner 90b as the second toner are contained in different image forming units S. In the first embodiment, the toner 90 contained in the developing devices 4Y, 4M, and 4C is referred to as toner 90a, and the toner 90 contained in the developing device 4K is referred to as toner 90b. However, this is not limited to this, and it is sufficient that the toner 90a and the toner 90b are contained separately in the developing devices 4Y, 4M, 4C, and 4K, respectively.

[0051] The volume average particle diameter of the toner 90 is preferably 5.0 to 9.0 μm. The volume average particle diameter of the toner 90 can be measured by the following measurement method. As the measuring device, a Coulter Multisizer IV (manufactured by Beckman Coulter, Inc.) is used. As the electrolyte, a solution prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of about 1 mass %, for example, ISOTON II (manufactured by Beckman Coulter, Inc.) can be used. As the measuring method, 0.1 to 5.0 ml of a surfactant (preferably an alkylbenzene sulfonate salt) is added as a dispersant to 100 to 150 ml of electrolyte solution, and 2 to 20 mg of the measurement sample is further added. The electrolyte in which the measurement sample is suspended is subjected to a dispersion treatment for about 1 minute with an ultrasonic disperser, and the volume particle size distribution is measured with a measuring device using a 100 μm aperture, and the measured median diameter (D50) is taken as the volume average particle diameter. In Example 1, the volume average particle diameter of the toner 90 was about 7.0 μm.

[0052] <Toner 90a> Next, the toner 90a as the first toner used in the first embodiment will be described. Toner particle 90a has protrusions containing an organosilicon polymer on the surface. The protrusions are in surface contact with the surface of the toner base particle. By making surface contact, it is expected that the effect of inhibiting the movement, detachment, and embedding of the protrusions is remarkable. To show the degree of surface contact, a cross-section of the toner was observed by STEM. Schematic diagrams of the protrusions of the toner particles are shown in Figures 3 to 6.

[0053] Fig. 3 is a schematic diagram of a cross-section of toner 90a observed by STEM. Fig. 3 shows a STEM image 91, which shows about 1 / 4 of the cross-sectional structure of a toner particle. The STEM image 91 shows a toner base particle 92, a toner base particle surface 93, and a protrusion 94. That is, the STEM image 91 in Fig. 3 is an image showing the cross-sectional structure in one of the four quadrants of a coordinate system whose origin is the center of the cross section of the toner particle, and it is presumed that the remaining three quadrants have a symmetrical similar structure.

[0054] A cross-sectional image of the toner is observed, and a line is drawn along the periphery of the surface of the toner base particle. A horizontal image is then formed based on the line along the periphery. In the horizontal image, the length of the line along the periphery in the portion where the convex portion and the toner base particle form a continuous interface is defined as the convex width W. The maximum length of the convex portion in the normal direction to the convex width W is defined as the convex diameter D, and the length from the apex of the convex portion to the line along the periphery in the line segment forming the convex diameter D is defined as the convex height H.

[0055] 4, 5, and 6 are schematic diagrams showing a method for measuring the protrusions 94 of the toner 90a according to Example 1. Fig. 4 shows a protrusion 94 formed when a surface along the periphery of the toner base particle 92, which is a substantially hemispherical particle, comes into contact with the toner base particle 92. Fig. 5 shows a protrusion 94 formed when a part of a spherical particle is buried in the toner base particle 92.

[0056] Figure 6 is a schematic representation of the adhesion state of bowl-shaped particles, which are semi-spherical particles with a concave center, obtained by crushing or breaking hollow particles. In Figure 6, the convex width W is the total length of the organosilicon compound in contact with the toner base particle surface. In other words, the convex width W in Figure 6 is the total of W1 and W2.

[0057] The configuration of the convex portions formed in the toner 90a manufactured by the manufacturing method of Example 1 described later is mostly constituted by convex portions 94 shown in Fig. 4, which have flat portions 94p and curved portions 94c described later. In Figs. 4 and 6, the convex diameter D and the convex height H are the same, and in Fig. 5, the convex diameter D is greater than the convex height H.

[0058] Based on the above conditions, it was found that if the convex portion of the organosilicon compound has a convex shape in which the ratio D / W of the convex diameter D to the convex width W is 0.33 or more and 0.80 or less, the convex portion is less likely to move, detach, or sink. In other words, it was found that, in the convex portion having a convex height H of 40 nm or more and 300 nm or less, if the number ratio NR(D / W) of the convex portions having the ratio D / W of 0.33 or more and 0.80 or less is 70 number % or more, excellent transferability capable of withstanding a long life is exhibited.

[0059] It is believed that the convex parts of 40 nm or more create a spacer effect between the toner base particle surface and the transfer member, improving transferability.On the other hand, it is believed that the convex parts of 300 nm or less have a remarkable effect of suppressing migration, detachment, and embedding through durability evaluation.

[0060] It has been found that if the number ratio NR(D / W) is 70% or more, which is the ratio of convex portions having a size of 40 nm or more and 300 nm or less, a higher effect of suppressing contamination of components is exhibited while maintaining transferability throughout durability. NR(D / W) is preferably 75% or more by number, and more preferably 80% or more by number. On the other hand, the upper limit is not particularly limited, but is preferably 99% or less by number, and more preferably 98% or less by number.

[0061] In addition, in cross-sectional observation of the toner by a scanning transmission electron microscope (STEM), the width of the horizontal image (the length of the line along the circumference of the surface of the toner base particle) is defined as the perimeter L. In this case, when the sum of the widths W of the convex parts of the organosilicon polymer present in the horizontal image, which have a convex height H of 40 nm or more and 300 nm or less, is defined as ΣW, it is preferable that ΣW / L is 0.30 or more and 0.90 or less. If ΣW / L is 0.30 or more, the transferability and the effect of suppressing member contamination are better, and if ΣW / L is 0.90 or less, the transferability is better. It is more preferable that ΣW / L is 0.45 or more and 0.80 or less.

[0062] Furthermore, the adhesion rate of the organosilicon polymer of the toner is preferably 80% by mass or more. If the adhesion rate is 80% by mass or more, the transferability and the effect of suppressing contamination of the member are more likely to be sustained through durable use. The adhesion rate is more preferably 90% by mass or more, and even more preferably 95% by mass or more. On the other hand, the upper limit is not particularly limited, but is preferably 99% by mass or less, and more preferably 98% by mass or less. Examples of methods for controlling the adhesion rate include the addition rate of the organosilicon polymer, the reaction temperature, the reaction time, the pH during the reaction, and the timing of pH adjustment when adding and polymerizing the organosilicon compound.

[0063] From the viewpoint of improving transferability, the cumulative distribution of the convex height H is taken for convex portions having a convex height H of 40 nm or more and 300 nm or less, and the convex height H that is integrated from the smallest convex height H and accounts for 80% by number is defined as H80. In this case, H80 is preferably 65 nm or more, and more preferably 75 nm or more. There is no particular upper limit, but it is preferably 120 nm or less, and more preferably 100 nm or less.

[0064] When the toner is observed with a scanning electron microscope (SEM), the maximum diameter of the convex portion of the organosilicon polymer is defined as the convex diameter R, and the number average diameter of the convex diameter R is preferably 20 nm or more and 80 nm or less, and more preferably 35 nm or more and 60 nm or less. When in the above range, component contamination is less likely to occur.

[0065] The toner comprises an organosilicon polymer having a structure represented by formula (1):

[0066] [ka]

[0067] (In formula (1), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.) In an organosilicon polymer having the structure of formula (1), one of the four valences of the Si atom is bonded to R, and the remaining three are bonded to O atoms. The O atom has two valences bonded to Si, that is, it forms a siloxane bond (Si-O-Si). When considering the Si atom and O atom as an organosilicon polymer, there are two Si atoms and three O atoms, so -SiO 3 / 2 This organosilicon polymer is expressed as -SiO 3 / 2 The structure is thought to have similar properties to silica (SiO2), which is composed of numerous siloxane bonds.

[0068] In the partial structure represented by formula (1), R is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Preferred examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group. More preferably, R is a methyl group.

[0069] The organosilicon polymer is preferably a condensation polymer of an organosilicon compound having a structure represented by the following formula (Z).

[0070] [ka]

[0071] (In formula (Z), R1 represents a hydrocarbon group having 1 to 6 carbon atoms (preferably an alkyl group), and R2, R3, and R4 each independently represent a halogen atom, a hydroxyl group, an acetoxy group, or an alkoxy group.) R1 is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, more preferably a methyl group. R2, R3, and R4 are each independently a halogen atom, a hydroxyl group, an acetoxy group, or an alkoxy group (hereinafter also referred to as a reactive group). These reactive groups undergo hydrolysis, addition polymerization, and condensation polymerization to form a crosslinked structure.

[0072] From the viewpoint of mild hydrolysis at room temperature and deposition onto the surface of the toner base particles, an alkoxy group having 1 to 3 carbon atoms is preferable, and a methoxy group or an ethoxy group is more preferable.

[0073] The hydrolysis, addition polymerization, and condensation polymerization of R2, R3, and R4 can be controlled by the reaction temperature, reaction time, reaction solvent, and pH. To obtain the organosilicon polymer used in the present invention, it is advisable to use one or a combination of several organosilicon compounds (hereinafter also referred to as trifunctional silanes) having three reactive groups (R2, R3, and R4) in one molecule excluding R1 in the formula (Z) shown above.

[0074] Examples of the compound represented by the above formula (Z) include the following. Trifunctional methylsilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxychlorosilane, methylmethoxyethoxychlorosilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, and methyldiethoxyhydroxysilane. Trifunctional silanes such as ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, and hexyltrihydroxysilane. Trifunctional phenylsilanes such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrihydroxysilane.

[0075] In addition, to the extent that the effect of the present invention is not impaired, an organosilicon polymer obtained by combining the following with an organosilicon compound having a structure represented by formula (Z) may be used. An organosilicon compound having four reactive groups in one molecule (tetrafunctional silane), an organosilicon compound having two reactive groups in one molecule (bifunctional silane), or an organosilicon compound having one reactive group (monofunctional silane). For example, the following may be mentioned. Trifunctional vinyl silanes such as dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, vinyltriisocyanatesilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane, and vinyldiethoxyhydroxysilane.

[0076] Furthermore, the content of the organosilicon polymer in the toner particles is preferably from 1.0% to 10.0% by weight.

[0077] A preferred method for forming the specific convex shape on the toner particle surface includes a method in which toner base particles are dispersed in an aqueous medium to obtain a toner base particle dispersion, and an organosilicon compound is then added to the toner base particle dispersion to form the convex shape, thereby obtaining a toner particle dispersion.

[0078] The toner base particle dispersion liquid is preferably adjusted to have a solids concentration of 25% by mass or more and 50% by mass or less. The temperature of the toner base particle dispersion liquid is preferably adjusted to 35° C. or more. The pH of the toner base particle dispersion liquid is preferably adjusted to a pH at which condensation of the organosilicon compound does not proceed easily. The pH at which condensation of the organosilicon polymer does not proceed easily varies depending on the substance, so it is preferably within ±0.5 of the pH at which the reaction does not proceed easily.

[0079] On the other hand, it is preferable to use an organosilicon compound that has been subjected to hydrolysis treatment. For example, the organosilicon compound is hydrolyzed in a separate vessel as a pretreatment. The concentration of the hydrolysis is preferably 40 parts by mass or more and 500 parts by mass or less, more preferably 100 parts by mass or more and 400 parts by mass or less, of water from which ions have been removed, such as ion-exchanged water or RO water, when the amount of the organosilicon compound is 100 parts by mass. The hydrolysis conditions are preferably pH 2 to 7, temperature 15 to 80°C, and time 30 to 600 minutes.

[0080] The obtained hydrolysis liquid is mixed with the toner base particle dispersion liquid, and the pH is adjusted to a value suitable for condensation (preferably 6 to 12, or 1 to 3, more preferably 8 to 12). The amount of the hydrolysis liquid is adjusted to 5.0 parts by mass or more and 30.0 parts by mass or less of the organosilicon compound per 100 parts by mass of the toner base particles, which makes it easier to form the convex shape. The temperature and time for the formation of the convex shape and the condensation are preferably 35°C to 99°C, and the mixture is maintained for 60 minutes to 72 hours.

[0081] In addition, in controlling the convex shape of the surface of the toner particles, it is preferable to adjust the pH in two stages. The convex shape of the surface of the toner particles can be controlled by appropriately adjusting the holding time before adjusting the pH and the holding time before adjusting the pH in the second stage to condense the organosilicon compound. For example, it is preferable to hold at pH 4.0 to 6.0 for 0.5 to 1.5 hours, and then hold at pH 8.0 to 11.0 for 3.0 to 5.0 hours. The convex shape can also be controlled by adjusting the condensation temperature of the organic compound in the range of 35°C to 80°C.

[0082] For example, the convex width W can be controlled by the amount of organosilicon compound added, the reaction temperature, the first-stage reaction pH, the reaction time, etc. For example, the convex width tends to increase as the first-stage reaction time increases.

[0083] The convex diameter D and convex height H can be controlled by the amount of organosilicon polymer added, the reaction temperature, the second-stage pH, etc. For example, if the second-stage reaction pH is high, the convex diameter D and convex height H tend to be large.

[0084] Specific methods for producing the toner are described below, but are not limited to these. It is preferable to produce the toner base particles in an aqueous medium and form convex portions containing an organosilicon polymer on the surface of the toner base particles.

[0085] The preferred methods for producing toner base particles are suspension polymerization, solution suspension, and emulsion aggregation, with suspension polymerization being the most preferred. With suspension polymerization, the organosilicon polymer is easily precipitated uniformly on the surface of the toner base particles, and the organosilicon polymer has excellent adhesion, environmental stability, charge reversal component suppression effect, and durability.

[0086] The suspension polymerization method is further described below. The suspension polymerization method is a method for obtaining toner base particles by granulating a polymerizable monomer composition containing a polymerizable monomer capable of producing a binder resin and, if necessary, an additive such as a colorant, in an aqueous medium, and polymerizing the polymerizable monomer contained in the polymerizable monomer composition.

[0087] The polymerizable monomer composition may contain a release agent or other resins as necessary. After the polymerization step is completed, the generated particles may be collected by washing and filtration using a known method. The temperature may be raised in the latter half of the polymerization step. In addition, in order to remove unreacted polymerizable monomers or by-products, it is also possible to distill off a part of the dispersion medium from the reaction system in the latter half of the polymerization step or after the polymerization step is completed.

[0088] It is preferable to use the thus obtained toner base particles to form convex portions of the organosilicon polymer by the above-mentioned method.

[0089] The toner may contain a release agent. Examples of the release agent include the following. Paraffin wax, microcrystalline wax, petroleum waxes such as petrolatum and their derivatives, montan wax and its derivatives, hydrocarbon waxes produced by the Fischer-Tropsch process and their derivatives, polyolefin waxes such as polyethylene and polypropylene and their derivatives, natural waxes such as carnauba wax and candelilla wax and their derivatives, higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid, or their acid amides, esters, or ketones, hydrogenated castor oil and its derivatives, vegetable waxes, animal waxes, and silicone resins.

[0090] The derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. The release agents may be used alone or in combination.

[0091] The content of the release agent is preferably 2.0 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the binder resin or the polymerizable monomer that produces the binder resin.

[0092] As the other resin, for example, the following resins can be used. Homopolymers of styrene and its substituted derivatives such as polystyrene and polyvinyltoluene; styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, Styrene-based copolymers such as styrene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-dimethylaminoethyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-dimethylaminoethyl methacrylate copolymers, styrene-vinyl methyl ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resins, polyester resins, polyamide resins, epoxy resins, polyacrylic resins, rosin, modified rosin, terpene resins, phenolic resins, aliphatic or alicyclic hydrocarbon resins, and aromatic petroleum resins. These may be used alone or in combination.

[0093] Suitable examples of the polymerizable monomer include the vinyl polymerizable monomers shown below. 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-octyl, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl 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, dibutyl phosphate ethyl acrylate methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl 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 benzoate, 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.

[0094] Among these vinyl polymers, styrene, styrene derivatives, acrylic polymerizable monomers and methacrylic polymerizable monomers are preferred.

[0095] In addition, a polymerization initiator may be added when polymerizing the polymerizable monomer. Examples of the polymerization initiator include the following. azo- or diazo-based polymerization initiators such as 2,2'-azobis-(2,4-divaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile; peroxide-based polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyloxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide.

[0096] These polymerization initiators are preferably added in an amount of 0.5 to 30.0 parts by mass per 100 parts by mass of the polymerizable monomer, and may be used alone or in combination of two or more.

[0097] In order to control the molecular weight of the binder resin constituting the toner base particles, a chain transfer agent may be added during polymerization of the polymerizable monomer. The preferred amount of the chain transfer agent is 0.001 to 15,000 parts by mass per 100 parts by mass of the polymerizable monomer.

[0098] On the other hand, in order to control the molecular weight of the binder resin constituting the toner base particles, a crosslinking agent may be added during polymerization of the polymerizable monomer. For example, the following may be mentioned. Divinylbenzene, bis(4-acryloxypolyethoxyphenyl)propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol #200, #400, #600 diacrylates, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester diacrylate (MANDA Nippon Kayaku), and those in which the above acrylates have been replaced with methacrylates.

[0099] Examples of the polyfunctional crosslinkable monomer include the following. Pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis(4-methacryloxypolyethoxyphenyl)propane, diacryl phthalate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diaryl chlorendate.

[0100] The preferred amount added is 0.001 to 15,000 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

[0101] When the medium used in the suspension polymerization is an aqueous medium, the following can be used as a dispersion stabilizer for the particles of the polymerizable monomer composition. Tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina.

[0102] Examples of organic dispersants include the following: Polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch.

[0103] In addition, commercially available nonionic, anionic, or cationic surfactants can also be used. Examples of such surfactants include the following: Sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate.

[0104] A colorant may be used in the toner, and is not particularly limited and any known colorant may be used. The content of the colorant is determined based on 100 mass of the binder resin or the polymerizable monomer capable of forming the binder resin. It is preferable that the content of the binder is 3.0 parts by mass to 15.0 parts by mass.

[0105] A charge control agent can be used during toner production, and known charge control agents can be used. The amount of these charge control agents added is preferably 0.01 to 10.00 parts by mass with respect to 100 parts by mass of the binder resin or polymerizable monomer.

[0106] Various measurement methods relating to the toner 90a of the present invention will be described below.

[0107] (Method of observing the cross section of toner using a scanning transmission electron microscope (STEM)) A cross section of a toner to be observed with a scanning transmission electron microscope (STEM) is prepared as follows.

[0108] The procedure for preparing the cross section of the toner is as follows: First, the toner is spread onto a cover glass (Matsunami Glass Co., Ltd., square cover glass; square No. 1) in a single layer, and then an Os film (5 nm) and a naphthalene film (20 nm) are applied to the toner as a protective film using an osmium plasma coater (Filgen Co., Ltd., OPC80T).

[0109] Next, a PTFE tube (Φ1.5mm×Φ3mm×3mm) is filled with photocurable resin D800 (JEOL Ltd.), and the cover glass is gently placed on top of the tube so that the toner is in contact with the photocurable resin D800. In this state, the resin is hardened by irradiating it with light, and then the cover glass and tube are removed to form a cylindrical resin with the toner embedded in the outermost surface.

[0110] Using an ultrasonic ultramicrotome (Leica, UC7), a cutting speed of 0.6 mm / s is used to cut from the outermost surface of the cylindrical resin to the length of the toner radius (for example, 4.0 μm when the weight average particle size (D4) is 8.0 μm) to expose a cross section of the center of the toner.

[0111] Next, a thin sample of the cross section of the toner is prepared by cutting it to a thickness of 100 nm. By cutting in this manner, a cross section of the center of the toner can be obtained.

[0112] The STEM probe size is 1 nm, and the image size is 1024 x 1024 pixels. The bright field image is acquired by adjusting the Contrast on the Detector Control panel to 1425, the Brightness to 3750, and the Contrast on the Image Control panel to 0.0, Brightness to 0.5, and Gamma to 1.00. The image magnification is 100,000x, and the image is acquired so that it covers about one-quarter to one-half of the circumference of the cross section of one toner particle, as shown in Figure 3.

[0113] The obtained images are analyzed using image processing software (Image J (available from https: / / imagej.nih.gov / ij / )) and the convex parts containing the organosilicon polymer are measured. Image analysis is performed on 30 STEM images.

[0114] First, use the line drawing tool (select Segmented line in the Straght tab) to draw a line along the periphery of the toner base particle. In areas where the protruding parts of the organosilicon polymer are embedded in the toner base particle, connect the lines smoothly, assuming that they are not embedded.

[0115] Using that line as a reference, convert to a horizontal image (select Selection on the Edit tab, change line width to 500 pixels in properties, then select Selection on the Edit tab and run Straghtener). For each convex portion containing the organosilicon polymer in the horizontal image, measure the convex width W, convex diameter D, and convex height H using the method described above. Calculate N(D / W) from the results of measuring 30 STEM images. The cumulative distribution of the convex height H is taken and H80 is calculated.

[0116] In addition, the total value of the convex width W of the convex parts with a convex height H of 40 nm to 300 nm in the horizontal image used in the image analysis is defined as ΣW, and the width of the horizontal image used in the image analysis is defined as the perimeter L. The width of the horizontal image corresponds to the length of the surface of the toner base particle in the STEM image. ΣW / L is calculated from one image, and the arithmetic average value of 30 STEM images is used.

[0117] The detailed measurement of the convex portion is as described above and shown in FIGS.

[0118] Measurements are performed in Image J by overlaying the scale on the image with Straight Line on the Straight tab, and setting the length of the scale on the image with Set Scale on the Analyze tab. A line segment equivalent to the convex width W or convex height H can be drawn with Straight Line on the Straight tab, and measurements can be performed with Measure on the Analyze tab.

[0119] (Method of calculating the average grain size of convex parts in a scanning electron microscope (SEM)) The SEM observation was performed using images taken with a Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (manufactured by Hitachi High-Technologies Corporation). The image taking conditions for the S-4800 were as follows:

[0120] (1) Sample preparation A thin layer of conductive paste (TED PELLA, Inc., Product No. 16053, PELCO Colloidal Graphite, Isopropanol base) is applied to a sample stage (aluminum sample stage 15 mm x 6 mm), and toner is sprayed onto the paste. Excess fine particles are removed from the sample stage by air blowing, and platinum is then evaporated at 15 mA for 15 seconds. The sample stage is set in the sample holder, and the sample stage height is adjusted to 30 mm using the sample height gauge.

[0121] (2) S-4800 observation condition setting Pour liquid nitrogen into the anti-contamination trap attached to the S-4800 housing until it overflows, and leave it for 30 minutes. Start the S-4800's "PC-SEM" and perform flushing (cleaning the FE chip, which is the electron source). Click the accelerating voltage display area on the control panel on the screen, and press the [Flushing] button to open the flushing execution dialog. Check that the flushing intensity is 2, and execute it. Check that the emission current due to flushing is 20 to 40 μA. Insert the sample holder into the sample chamber of the S-4800 housing. Press [Origin] on the control panel to move the sample holder to the observation position.

[0122] Click the accelerating voltage display to open the HV setting dialog, and set the accelerating voltage to [2.0 kV] and the emission current to [10 μA]. In the [Basic] tab of the operation panel, set the signal selection to [SE], select the SE detector to [Bottom (L)], and set the mode to observe the backscattered electron image. In the same [Basic] tab of the operation panel, set the probe current in the electron optical system condition block to [Normal], the focus mode to [UHR], and the WD to [8.0 mm]. Press the [ON] button in the accelerating voltage display on the control panel to apply the accelerating voltage.

[0123] (3) Focus adjustment Drag within the magnification display on the control panel to set the magnification to 5000 (5k). Rotate the focus knob [COARSE] on the operation panel to adjust the aperture alignment when the image is in focus to a certain extent. Click to display the alignment dialog and select [Beam]. Rotate the STIGMA / ALIGNMENT knobs (X, Y) on the operation panel to move the displayed beam to the center of the concentric circle.

[0124] Next, select [Aperture] and turn the STIGMA / ALIGNMENT knobs (X,Y) one by one to stop the image movement or adjust it so that it moves as little as possible. Close the Aperture dialog and use autofocus to adjust the focus. Repeat this operation two more times to adjust the focus. With the midpoint of the maximum diameter of the observed particle aligned with the center of the measurement screen, drag within the magnification display area of ​​the control panel to set the magnification to 10,000 (10k). Turn the focus knob [COARSE] on the operation panel until the image is in focus to a certain extent, then adjust the aperture alignment. Click [Align] on the control panel to display the alignment dialog and select [Beam]. Turn the STIGMA / ALIGNMENT knobs (X,Y) on the operation panel to move the displayed beam to the center of the concentric circles.

[0125] Next, select [Aperture] and turn the STIGMA / ALIGNMENT knobs (X, Y) one by one to stop the image movement or adjust it so that the movement is minimized. Close the Aperture dialog and adjust the focus using autofocus. After that, set the magnification to 50,000 (50k) times and adjust the focus using the focus knob and STIGMA / ALIGNMENT knob as above, then use autofocus to focus again. Repeat this operation to adjust the focus.

[0126] (4) Image storage Adjust the brightness in ABC mode, then take and save a photo with a size of 640 x 480 pixels.

[0127] From the obtained SEM image, the number average diameter (D1) of 500 protrusions of 20 nm or more present on the toner particle surface was calculated using image processing software (Image J). The method for measuring the number average diameter of the protrusions of the organosilicon polymer is as follows.

[0128] Particle analysis is used to binarize the convex parts and toner base particles in the image and color-code them. Next, the maximum length of the selected shape is selected from the measurement commands, and the convex diameter R (maximum diameter) of one convex part is measured. This operation is repeated multiple times to find the arithmetic mean value of 500 points, thereby calculating the number-average diameter of the convex diameter R.

[0129] (Method of measuring adhesion rate of organosilicon polymer) Add 160 g of sucrose (Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a concentrated sucrose solution. Add 31 g of the concentrated sucrose solution and 6 mL of Contaminon N (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of nonionic surfactants, anionic surfactants, and organic builders, manufactured by Wako Pure Chemical Industries, Ltd.) to a centrifuge tube (volume 50 ml) to prepare a dispersion. Add 1.0 g of toner to this dispersion and break up the toner clumps with a spatula or similar.

[0130] The centrifuge tube is shaken in a shaker at 350 strokes per minute (spm) for 20 minutes. After shaking, the solution is transferred to a glass tube for a swing rotor (50 mL capacity) and separated in a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.) at 3500 rpm for 30 minutes. Visually check that the toner and aqueous solution are sufficiently separated, and collect the toner that has separated into the top layer with a spatula or similar. The collected aqueous solution containing the toner is filtered through a vacuum filter, and then dried in a dryer for at least 1 hour. The dried product is crushed with a spatula, and the amount of silicon is measured using fluorescent X-rays. The amount of the measured elements in the toner after washing with water and in the initial toner The adhesion rate (%) is calculated from the ratio.

[0131] The measurement of fluorescent X-rays for each element conforms to JIS K 0119-1969, and specifically, is as follows.

[0132] The measurement equipment used is a wavelength dispersive X-ray fluorescence analyzer "Axios" (PANalytical) and the accompanying dedicated software "SuperQ ver.4.0F" (PANalytical) for setting measurement conditions and analyzing measurement data. Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 10 mm, and the measurement time is 10 seconds. In addition, detection is performed with a proportional counter (PC) when measuring light elements, and a scintillation counter (SC) when measuring heavy elements.

[0133] The measurement sample was prepared by placing approximately 1 g of the washed toner and the initial toner in a special aluminum ring with a diameter of 10 mm for pressing, flattening it, and pressing it at 20 MPa for 60 seconds using a tablet molding compression machine "BRE-32" (manufactured by Maekawa Test Machinery Manufacturing Co., Ltd.) to form a pellet with a thickness of approximately 2 mm.

[0134] Measurements are performed under the above conditions, and elements are identified based on the peak positions of the obtained X-rays, and their concentrations are calculated from the counting rate (unit: cps), which is the number of X-ray photons per unit time.

[0135] The method for quantifying the amount of silicon in the toner is, for example, to add 0.5 parts by mass of silica (SiO2) fine powder to 100 parts by mass of toner particles, and thoroughly mix using a coffee mill. Similarly, 2.0 parts by mass and 5.0 parts by mass of silica fine powder are mixed with the toner particles, respectively, and these are used as samples for the calibration curve.

[0136] For each sample, a pellet of the calibration curve sample is prepared as described above using a tablet press, and the count rate (unit: cps) of the Si-Kα ray observed at a diffraction angle (2θ) = 109.08° when PET is used as the analyzing crystal is measured. In this case, the acceleration voltage and current value of the X-ray generator are 24 kV and 100 mA, respectively. A linear function calibration curve is obtained by plotting the obtained X-ray count rate on the vertical axis and the amount of SiO2 added in each calibration curve sample on the horizontal axis.

[0137] Next, the toner to be analyzed is pelletized as described above using a tablet molding machine, and the count rate of the Si-Kα radiation is measured. The content of the organosilicon polymer in the toner is then calculated from the calibration curve. The ratio of the amount of elements in the toner after washing with water to the amount of elements in the initial toner calculated by the above method is calculated and used as the adhesion rate (%).

[0138] A specific description will be given below of a manufacturing example of the toner 90a in Example 1, but the toner 90a of the present invention is not limited to this manufacturing example. In addition, the "parts" of each material in the manufacturing examples are all based on mass unless otherwise specified.

[0139] (Production Example of Toner 90a) (1) Preparation of aqueous medium F In a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 650.0 parts of ion-exchanged water and 14.0 parts of sodium phosphate (Rasa Kogyo Co., Ltd., 12-hydrate) were added, and the mixture was kept at 65°C for 1.0 hour while purging with nitrogen.

[0140] A calcium chloride aqueous solution in which 9.2 parts of calcium chloride (dihydrate) was dissolved in 10.0 parts of ion-exchanged water was added all at once while stirring at 15,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare an aqueous medium containing a dispersion stabilizer. 10% by mass of hydrochloric acid was added to the aqueous medium to adjust the pH to 5.0, and aqueous medium F was obtained.

[0141] (2) Preparation of polymerizable monomer composition Styrene: 60.0 parts CI Pigment Blue 15:3:6.5 parts

[0142] The above materials were charged into an attritor (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and further dispersed using zirconia particles having a diameter of 1.7 mm at 220 rpm for 5.0 hours to prepare a pigment dispersion. The following materials were added to the above pigment dispersion.

[0143] Styrene: 20.0 parts n-Butyl acrylate: 20.0 parts Crosslinking agent (divinylbenzene): 0.3 parts Saturated polyester resin: 5.0 parts (Polycondensation product of propylene oxide modified bisphenol A (2 mole adduct) and terephthalic acid (molar ratio 10:12), glass transition temperature Tg = 68°C, weight average molecular weight Mw = 10,000, molecular weight distribution Mw / Mn = 5.12) Fischer-Tropsch wax (melting point 78°C): 7.0 parts

[0144] The mixture was kept at 65° C. and was uniformly dissolved and dispersed at 500 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a polymerizable monomer composition.

[0145] (3) Granulation process While maintaining the temperature of the aqueous medium F at 70° C. and the rotation speed of the TK homomixer at 15,000 rpm, the polymerizable monomer composition was charged into the aqueous medium F, and 10.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring speed at 15,000 rpm.

[0146] (4) Polymerization and distillation process After the granulation step, the agitator was replaced with a propeller agitator and the mixture was stirred at 150 rpm while maintaining the temperature at 70° C. for 5.0 hours, and then the temperature was raised to 85° C. and heated for 2.0 hours to carry out the polymerization reaction.

[0147] Thereafter, the reflux tube of the reaction vessel was replaced with a cooling tube, and the slurry was heated to 100° C. to perform distillation for 6 hours to distill off the unreacted polymerizable monomer, thereby obtaining a toner base particle dispersion liquid.

[0148] (5) Polymerization of organosilicon compounds 60.0 parts of ion-exchanged water was weighed into a reaction vessel equipped with a stirrer and a thermometer, and the pH was adjusted to 4.0 using 10% by mass hydrochloric acid. This was heated with stirring to a temperature of 40°C. Then, 40.0 parts of methyltriethoxysilane, an organosilicon compound, was added and stirred for 2 hours or more to carry out hydrolysis. The end point of hydrolysis was confirmed by visual observation when the oil and water did not separate and became one layer, and the mixture was cooled to obtain a hydrolyzed liquid of an organosilicon compound.

[0149] The temperature of the obtained toner base particle dispersion liquid was cooled to 55°C, and then 25.0 parts of the hydrolyzed liquid of the organosilicon compound was added to initiate polymerization of the organosilicon compound. After maintaining the mixture for 15 minutes, the pH was adjusted to 5.5 with a 3.0% aqueous sodium bicarbonate solution. After maintaining the mixture at 55°C for 60 minutes while continuing to stir, the pH was adjusted to 9.5 with a 3.0% aqueous sodium bicarbonate solution, and the mixture was maintained for another 240 minutes to obtain a toner particle dispersion liquid.

[0150] (6) Washing and drying process After the polymerization process was completed, the toner particle dispersion was cooled, and hydrochloric acid was added to the toner particle dispersion to adjust the pH to 1.5 or less, and the dispersion was left to stand with stirring for 1 hour, after which the dispersion was subjected to solid-liquid separation using a pressure filter to obtain a toner cake. This was reslurried in ion-exchanged water to make a dispersion again, and then the dispersion was subjected to solid-liquid separation using the aforementioned filter to obtain a toner cake.

[0151] The obtained toner cake was dried and classified in a thermostatic chamber at 40° C. for 72 hours to obtain toner particles.

[0152] The toner particles may be used as they are as toner 90a, or various organic or inorganic fine powders may be added to the toner particles as necessary. The organic or inorganic fine powder preferably has a particle size of 1 / 10 or less of the weight average particle size of the toner particles in terms of durability when added to the toner particles.

[0153] As the organic or inorganic fine powder, for example, the following may be used alone or in combination.

[0154] (1) Fluidity imparting agents: silica, alumina, titanium oxide, carbon black and carbon fluoride. (2) Abrasives: metal oxides (e.g., strontium titanate, cerium oxide, alumina, magnesium oxide, chromium oxide), nitrides (e.g., silicon nitride), carbides (e.g., silicon carbide), metal salts (e.g., calcium sulfate, barium sulfate, calcium carbonate). (3) Lubricants: Fluorine-based resin powder (e.g., vinylidene fluoride, polytetrafluoroethylene), fatty acid metal salts (e.g., zinc stearate, calcium stearate). (4) Charge control particles: metal oxides (e.g., tin oxide, titanium oxide, zinc oxide, silica, alumina), carbon black.

[0155] In order to improve the fluidity of the toner and to make the toner uniformly charged, the organic or inorganic fine powder may be subjected to a surface treatment. Examples of the treatment agent for the hydrophobic treatment of the organic or inorganic fine powder include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds. These treatment agents may be used alone or in combination.

[0156] The total amount of these various organic or inorganic fine powders added is preferably 0.05 parts by weight to 1.2 parts by weight per 100 parts by weight of toner, because toner 90a has protrusions containing an organosilicon polymer on the surface of the toner particles, and if the surface is further covered with a large amount of fine powder, the fixing property decreases.

[0157] When the toner 90a prepared as described above was used in the developing device 4 of Example 1, the toner 90a was negatively charged.

[0158] Next, the lubricating effect when the toner 90a is supplied to the cleaning nip N3 will be described.

[0159] As described above, the toner 90a is composed of toner base particles 92 and a plurality of convex portions 94 formed on the surfaces of the toner base particles. As the photosensitive drum 1 rotates, the toner 90a reaches the cleaning nip N3 and rubs against the cleaning blade 61, causing at least some of the convex portions 94 formed on the surface of the toner 90a to move and detach from the toner base particles 92. The hemispherical convex portions 94 that have moved and detached are deposited near the entrance of the cleaning nip N3 and are pushed by other following convex portions 94 that have also moved and detached, with some of them being taken into the cleaning nip N3. Then, in the cleaning nip N3, the hemispherical convex portions 94 are pushed by the other convex portions 94 that have moved and detached, causing at least some of them to be taken into the cleaning nip N3. The flat surface 94p of the hemispherical protrusion 94 adheres to the surface of the cleaning blade 61 and is held in place by the movement of the surface of the cleaning blade 61. This reduces the contact area between the photosensitive drum 1 and the cleaning blade 61, thereby reducing the frictional force.

[0160] In addition, the protrusions 94 formed on the surface of the toner 90a are in close contact with the surface of the toner base particle and are linked to the surrounding protrusions 94 to form a network, which provides excellent durability. Therefore, in order for some of the protrusions 94 to move and detach from the toner base particle 92, the toner 90a needs time to be repeatedly rubbed against the cleaning blade 61 and the photosensitive drum 1 near the entrance of the cleaning nip N3.

[0161] <Toner 90b> Next, the toner 90b used in the present invention will be described. In the first embodiment, a negatively charged non-magnetic toner produced by a suspension polymerization method is used as the toner 90b. However, the toner 90b is not limited to this, and may be a toner produced by other polymerization methods such as a pulverization method or an emulsion polymerization method.

[0162] Toner 90b is externally added with various organic or inorganic fine powders in order to improve fluidity, chargeability, cleaning properties, etc. As the organic or inorganic fine powders, for example, the same ones as those used in toner 90a can be used alone or in combination.

[0163] The toner 90b contains at least silica particles having an average primary particle size of 40 nm or less, preferably 20 nm or less, because when the toner 90b is supplied to the cleaning nip N3, the silica particles that move or detach from the surface of the toner 90b easily enter the cleaning nip N3, and the lubricating effect is easily exerted.

[0164] The average primary particle size of the organic or inorganic fine powder is measured using a Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (manufactured by Hitachi High-Technologies Corporation). The toner 90b to which various organic or inorganic fine powders have been externally added is observed, and the major axis of 100 or more primary particles of the various organic or inorganic fine powders is measured randomly in a field of view magnified up to 200,000 (200k) times to obtain the number-average particle size. The observation magnification is appropriately adjusted depending on the size of the various organic or inorganic fine powders. In addition, the measurement is performed while comparing images mapped with the elements contained in the various organic or inorganic fine powders using an elemental analysis means such as XMA attached to the scanning electron microscope.

[0165] In toner 90b, the total amount of these various organic or inorganic fine powders added is 0.05 parts by weight to 5.0 parts by weight, preferably 0.1 parts by weight to 3.0 parts by weight, per 100 parts by weight of toner. This is because toner 90b does not have protrusions containing an organosilicon polymer on the toner particle surface, and therefore can hold more fine powder on the toner particle surface. In Example 1, silica particles with an average primary particle size of about 10 nm were used, with 1.6 parts by weight externally added per 100 parts by weight of toner.

[0166] Next, the lubricating effect when the toner 90b is supplied to the cleaning nip N3 will be described.

[0167] As described above, the toner 90b contains at least silica particles having an average primary particle size of 40 nm or less (preferably an average primary particle size of 20 nm or less). The toner 90b also contains a larger amount of various organic or inorganic fine powders added to the toner particle surfaces than the toner 90a. When the toner 90b reaches the cleaning nip N3 as the photosensitive drum 1 rotates, it rubs against the cleaning blade 61, and some of the organic or inorganic fine powders added to the surface of the toner 90b move and detach from the surface of the toner 90b. At this time, the organic or inorganic fine powders that have been added to the surface of the toner 90b move and detach from the surface of the toner 90b. The amount of organic or inorganic fine powder that moves to the toner 90b is greater than the amount of protrusions 94 that move and detach from the surface of the toner 90a. In other words, the toner 90b has a higher lubricant supplying ability than the toner 90a. In addition, since the toner 90b uses silica particles with a small average primary particle size, the silica particles that move and detach from the surface of the toner 90b easily enter the cleaning nip N3, and the lubricating effect is quickly achieved.

[0168] On the other hand, the toner 90b is easily discharged from the cleaning nip N3, and is less likely to be retained on the surface of the cleaning blade 61 than the hemispherical protrusions 94 of the toner 90a. Therefore, when the amount of organic or inorganic fine powder accumulated near the entrance of the cleaning nip N3 decreases and the supply of lubricant decreases, the lubricating effect decreases. An example of a case where the amount of fine powder accumulated near the entrance of the cleaning nip N3 decreases is when the developing device 4 has been used for a long period of time and the toner 90b in the developing device 4 is repeatedly rubbed, causing the fine powder on the surface of the toner 90b to move, fall off, or sink.

[0169] <Control mode> Next, a description will be given of the control mode in the image forming apparatus 100 of the embodiment 1. Fig. 7 is a block diagram showing an outline of the control mode of the image forming apparatus 100 of the embodiment 1.

[0170] In the first embodiment, as shown in Fig. 7, the image forming apparatus 100 includes a control unit 101 as a control means configured with a CPU and the like for controlling the apparatus main body 111. The control unit 101 includes a CPU 102 as a calculation processing means which is a central element for performing calculation processing, a storage unit 103 such as a ROM, RAM, and non-volatile memory as a storage means, and an input / output unit (not shown). The ROM stores a control program, a data table obtained in advance, and the like. The RAM stores information input to the control unit 101, detected information, calculation results, and the like. The input / output unit inputs and outputs signals between the control unit 101 and devices connected thereto.

[0171] Each part of the image forming apparatus 100 is connected to the control unit 101. The control unit 101 communicates bidirectionally with each part of the image forming apparatus 100 to control the operation of each part. For example, various power sources (power supply devices, high-voltage power supply circuits) such as a charging power source 80, a developing power source 81, a supply power source 82, a regulating power source 83, a primary transfer power source 70, a secondary transfer power source 71, and a conductive brush power source 72 are connected to the control unit 101. In addition, for example, various motors (drive units, drive sources) such as a drum drive motor 51, a developing drive motor 52, and a belt drive motor 53, and a developing contact / separation mechanism 54 are connected to the control unit 101. In the first embodiment, the drum drive motor 51 transmits a rotational drive force to the photosensitive drum 1, and the developing drive motor 52 transmits a rotational drive force to the developing roller 42 and the supply roller 43 to drive them. However, this is not limited to this, and for example, the motor that transmits the rotational drive force to the photosensitive drum 1 and the motor that transmits the rotational drive force to the developing roller 42 and the supply roller 43 may be common.

[0172] The process cartridge 8 is also provided with a memory 104 which is a non-volatile storage means. The memory 104 stores information on whether the process cartridge 8 is unused (new) or not, usage information of the developing device 4, and the like. In the first embodiment, the memory 104 is provided in the cleaning frame 17. However, the present invention is not limited to this. The control unit 101 can read and write information from and to the memory 104 of the process cartridge 8 mounted in the apparatus main body 111. In other words, the control unit 101 can execute various operations based on detection information of the memory 104 which serves as detection means for detecting whether the process cartridge 8 is unused (new) or not.

[0173] <Toner supply during initial installation> In the first embodiment, when the process cartridge 8 is initially installed, the cleaning cartridge 8 is replaced with the developing device 4 of the process cartridge 8 that contains the toner 90b. A predetermined amount of toner 90b is supplied to the cartridge N3. Here, the initial installation operation is an operation that is executed when the process cartridge 8 mounted in the apparatus main body 111 of the image forming apparatus 100 is determined to be in an unused (brand new) state.

[0174] In the image forming apparatus 100 of the first embodiment, when the process cartridge 8 is mounted in the apparatus main body 111, the control unit 101 judges whether the mounted process cartridge 8 is unused (new) or not. Here, a known detection means can be used to judge whether the process cartridge 8 is unused (new) or not. The control unit 101 judges whether the process cartridge 8 is unused (new) or not based on the detection result of the known detection means, and performs an initial installation operation if the process cartridge 8 is unused. On the other hand, if the process cartridge 8 is not unused, the control unit 101 performs a predetermined preparatory operation and enters a standby state (READY state) in which the image forming operation can be started.

[0175] In the first embodiment, the memory 104 is used as a detection means for detecting whether the process cartridge 8 is unused (new) or not. For example, by configuring the memory 104 to set a usage flag in a predetermined location when the initial installation operation is completed, it becomes possible to detect whether the process cartridge 8 is unused (new) or not based on whether the usage flag is set.

[0176] Fig. 8 is a schematic diagram of the initial installation operation in the image forming apparatus 100 of the first embodiment. In Fig. 8, the horizontal axis indicates time. Using Fig. 8, as an example of the initial installation operation, the initial installation operation in a case where all of the process cartridges 8Y, 8M, 8C, and 8K mounted in the apparatus main body 111 of the image forming apparatus 100 are determined to be unused (brand new) will be described.

[0177] When the initial setting operation is started, a developing device preparation process is first performed. In the first embodiment, when the initial setting operation is started at timing t1, the photosensitive drum 1 is rotated and a DC voltage of −1150 V is applied to the charging roller 2, so that the surface of the photosensitive drum 1 is charged to a surface potential of −500 V.

[0178] In addition, in accordance with the rotational drive of the photosensitive drum 1, the developing roller 42 and the supply roller 43 are also rotated, and the developing roller 42 comes into contact with the photosensitive drum 1 at a predetermined contact width by the development contact / separation mechanism 54. In addition, in accordance with the rotational drive of the developing roller 42 and the supply roller 43, a DC voltage of −350 V is applied to the developing roller 42, and a DC voltage of −450 V is applied to the supply roller 43 and the regulating blade 44.

[0179] As the developing device 4 is driven, the toner 90 contained in the developing device 4 is stirred and filled into the foam layer of the supply roller 43, and the toner 90 is supplied from the supply roller 43 to the surface of the developing roller 42. Then, the supply roller 43 continues to drive for a predetermined time until the supply of the toner 90 from the supply roller 43 to the surface of the developing roller 42 is stably performed and the formation of the toner 90 layer by the regulating blade 44 is stably performed. In the first embodiment, the time of the developing device preparation step (the time from timing t1 to timing t2) is set to 50 seconds as the predetermined time.

[0180] In the developing device preparation process, the intermediate transfer belt 7 is also driven by the belt drive motor 53 in synchronization with the driving of the photosensitive drum 1 and the developing device 4. A predetermined DC voltage having the same polarity as the normal charging polarity of the toner 90 (negative polarity in the first embodiment) is applied to the primary transfer roller 5.

[0181] Next, at timing t2, a toner supplying step is performed. Figures 9(a) to 9(c) are schematic diagrams for explaining the toner supplying step of the initial setting operation in Example 1. In Figures 9(a) to 9(c), the driving directions of main members are indicated by arrows.

[0182] At timing t2, the photosensitive drum 1K of the process cartridge 8K containing the toner 90b is exposed to the laser light LsK by the exposure device 3, and the electrostatic latent image is developed by the toner 90b on the development roller 42K. Then, a predetermined toner image is formed by the toner 90b and is primarily transferred onto the intermediate transfer belt 7. At this time, a predetermined DC voltage of a polarity opposite to the normal charging polarity of the toner 90 (positive polarity in the first embodiment) is applied to the first transfer roller 5. As shown in FIG. 9(a), in the first embodiment, four horizontal bands E aligned in the moving direction Tr of the surface of the intermediate transfer belt 7 are formed as the predetermined toner image. Hereinafter, the four horizontal bands E will be described as horizontal bands Ea, Eb, Ec, and Ed, in order from the downstream side to the upstream side of the moving direction Tr of the surface of the intermediate transfer belt 7, as necessary.

[0183] In the case of adjacent horizontal bands Ea and Eb on the intermediate transfer belt 7, the interval Ga between the leading edge of the horizontal band Ea and the leading edge of the horizontal band Eb is set to the distance between the primary transfer portion N1K of the adjacent process cartridge 8K and the primary transfer portion N1C of the adjacent process cartridge 8C. Similarly, in the case of adjacent horizontal bands Eb and Ec, the interval Gb between the leading edge of the horizontal band Eb and the leading edge of the horizontal band Ec is set to the distance between the primary transfer portion N1C of the adjacent process cartridge 8C and the primary transfer portion N1M of the adjacent process cartridge 8M. Similarly, in the case of adjacent horizontal bands Ec and Ed, the interval Gc between the leading edge of the horizontal band Ec and the leading edge of the horizontal band Ed is set to the distance between the primary transfer portion N1M of the adjacent process cartridge 8M and the primary transfer portion N1Y of the adjacent process cartridge 8Y. In the first embodiment, the distance between the primary transfer portions N1 is the same, so Ga=Gb=Gc.

[0184] The toner image made of the toner 90b in the toner supplying process is desirably formed over a wide range in the direction of the rotation axis of the photosensitive drum 1 (the same as the longitudinal direction of the cleaning member 6). In the first embodiment, the four horizontal bands E of the toner image are horizontal bands extending parallel to the rotation axis of the photosensitive drum 1 from one end of the photosensitive drum 1 to the other end, including the center of the photosensitive drum 1.

[0185] The shape of the horizontal bands E is not limited to the above-mentioned shape. For example, if the width of each horizontal band E in the moving direction Tr is smaller than the distance between the primary transfer parts N1 of two adjacent process cartridges, the horizontal bands do not have to be formed parallel to the rotation axis direction of the photosensitive drum 1. Also, five or more horizontal bands E whose width in the moving direction Tr is smaller than the distance between the primary transfer parts N1 of two adjacent process cartridges may be formed.

[0186] In the first embodiment, the width of each of the four horizontal bands E in the moving direction Tr of the surface of the intermediate transfer belt 7 (the width in the moving direction of the surface of the photosensitive drum 1) is 65 mm, and the width in the direction of the rotation axis of the photosensitive drum 1 is 230 mm. After the toner image of the toner 90b is entirely primarily transferred onto the intermediate transfer belt 7, the developing roller 42 is separated from the photosensitive drum 1 by the developing contact / separation mechanism 54.

[0187] 9B, as the intermediate transfer belt 7 rotates, a predetermined DC voltage of the same polarity as the normal charging polarity of the toner 90 is applied to the secondary transfer roller 9 and the conductive brush 15 at the timing when the horizontal band Ea on the intermediate transfer belt 7 reaches the secondary transfer portion N2. In the first embodiment, a negative DC voltage is applied to the secondary transfer roller 9 and the conductive brush 15. As a result, the horizontal band E, which is the toner image on the intermediate transfer belt 7, is less likely to be collected by the secondary transfer roller 9 and the conductive brush 15 when passing through the contact portion between the secondary transfer portion N2 and the conductive brush 15 and the intermediate transfer belt 7.

[0188] Then, as shown in FIG. 9(c), when the leading edge of the horizontal band Ea on the intermediate transfer belt 7 reaches the primary transfer portion N1K, the photosensitive drum 1 of each process cartridge 8 is exposed to the laser light Ls (LsY, LsM, LsC, LsK) of the exposure device 3. At the same time, a predetermined DC voltage of the same polarity as the normal charging polarity of the toner 90 (negative polarity in Example 1) is applied to the primary transfer roller 5, and the horizontal band E on the intermediate transfer belt 7 is collected onto each photosensitive drum 1. The horizontal band E (toner image made of toner 90b) collected on the photosensitive drum 1 is supplied to the cleaning nip N3 as the photosensitive drum 1 rotates. In Example 1, the time for the toner supply process (the time from timing t2 to timing t3) is set to 2.4 sec.

[0189] When the toner supply process is completed at timing t3, the development contact rotation process is performed. At timing t3, the development contact separation mechanism 54 brings each development roller 42 into contact with the corresponding photosensitive drum 1 at a predetermined contact width. Then, the development rollers 42 are driven for a predetermined time in this state. This is to suppress the generation of abnormal noise while silica particles, etc., which have moved and detached from the surface of the toner 90b, accumulate near the entrance of the cleaning nip N3 and enter the cleaning nip N3 to exert a lubricating effect. That is, even if the frictional force between the photosensitive drum 1 and the cleaning blade 61 increases and the stick-slip phenomenon of the cleaning blade 61 is likely to occur, the development roller 42 is brought into contact with the photosensitive drum 1 to suppress this vibration. In the first embodiment, the time of the development contact rotation process (the time from timing t3 to timing t4) is set to 38 seconds. Moreover, the voltage application conditions to each member at this time are the same as those in the development device preparation process.

[0190] Thereafter, at timing t4, a post-processing process is carried out. In the post-processing process, a post-rotation process (printing completion operation) that is normally carried out after an image forming operation and a cleaning operation for cleaning off the toner 90 remaining on the intermediate transfer belt 7 are carried out. When the post-processing process ends, at timing t5, the device enters a standby state (READY state) in which an image forming operation can be started. In the first embodiment, the initial setup operation time was 95 seconds in total.

[0191] As described above, in the initial installation operation of the first embodiment, a predetermined amount of toner 90b is supplied from the developing device 4K of the process cartridge 8K that contains the toner 90b to the cleaning nip N3 of each process cartridge 8 (8Y, 8M, 8C, 8K). By using the toner 90b that has a high lubricant supplying ability and quickly exhibits a lubricating effect, the generation of abnormal noise can be suppressed in a short initial installation operation time compared to the case where the toner 90a is supplied from the developing device 4 of the process cartridge 8 that contains the toner 90a.

[0192] The above-mentioned example of the initial installation operation is an example of the operation when all the process cartridges 8Y, 8M, 8C, and 8K mounted in the main body 111 of the image forming apparatus 100 are judged to be unused (new), but the initial installation operation is not limited to this. For example, when only the process cartridge 8Y is judged to be unused (new), a predetermined amount of toner 90b may be supplied from the developing device 4K that contains the toner 90b to only the cleaning nip N3Y of the process cartridge 8Y that is judged to be unused. In this way, if a predetermined amount of toner 90b is supplied from the developing device 4 that contains the toner 90b to the cleaning nip N3 of the process cartridge 8 that is judged to be unused (new), it is possible to reduce the time required for the initial installation operation and suppress the generation of abnormal noise. In turn, it is possible to suppress a decrease in productivity.

[0193] Furthermore, when the developing device 4 has been used for a long period of time and the toner 90b in the developing device 4 is repeatedly rubbed, thereby reducing the lubricant supplying ability of the toner 90b, it is possible to take appropriate measures such as increasing the amount of toner in a predetermined toner image in the toner supplying process. Methods for increasing the amount of toner in a predetermined toner image include, for example, increasing the amount of exposure by the exposure device 3 or increasing the exposure time (increasing the width of the horizontal band E in the moving direction Tr on the surface of the intermediate transfer belt 7).

[0194] In the first embodiment, in the developing device 4 in an unused state, a predetermined amount of coating agent may be applied to the surfaces of the developing roller 42 and the supply roller 43 in order to protect the surfaces of the members and reduce the torque at the start of driving. The coating agent is present on the developing roller 42 until a certain period of time has elapsed since the start of driving of the developing device 4, and is gradually replaced by the toner 90. In addition, in order to adjust the time during which the coating agent is present on the developing roller 42, it is also possible to appropriately adjust the surface potential of the photosensitive drum 1 at the start of driving of the developing device 4. As the coating agent, the same type of Y (yellow) toner as that contained in the developing device 4Y can be used. However, the coating agent is not limited to this, and as long as the particles satisfy the characteristics required for the coating agent, for example, spherical crosslinked fine particles of polyurethane resin may be used. Here, the characteristics required for the coating agent include, for example, characteristics that the coating agent does not show reactivity with any of the members such as the developing roller 42 and the supply roller 43, and that the adhesion force to the developing roller 42 is not too high. The material, shape, charge amount, and coating amount of the coating agent should be appropriately selected according to various configurations.

[0195] In addition, in the first embodiment, in order to prevent the cleaning blade 61 from turning over when the photosensitive drum 1 starts to drive in the unused photosensitive unit 16, for example, a highly lubricating substance may be added to the outermost layer of the photosensitive drum 1. As the highly lubricating substance, known substances such as silicone oil and siloxane modified resin can be used, and among them, the use of siloxane modified resin can form a highly lubricating surface of the photosensitive drum 1. Furthermore, the use of siloxane resin having a viscosity average molecular weight of 10,000 or less is more preferable because it can provide a more highly lubricating surface of the photosensitive drum 1. These highly lubricating substances are peeled off by the surface of the photosensitive drum 1 rubbing against contact members such as the cleaning blade 61, the intermediate transfer belt 7, or the charging roller 2, and the effect gradually decreases during the initial installation operation.

[0196] <Toner supply after initial installation> In the first embodiment, a toner supplying operation is performed even after the initial installation operation in order to provide lubricity to the cleaning blade 61. In the toner supplying operation after the initial installation operation, at least the toner 90a, which maintains its lubricating effect for a relatively long time, is supplied to the cleaning nip N3 of the process cartridge 8. If the toner supplying operation in the initial installation operation is the first toner supplying operation, in the first embodiment, the control unit 101 is configured to be able to execute a second toner supplying operation and a third toner supplying operation in addition to the first toner supplying operation.

[0197] (Second toner supply operation) In the second toner supply operation, at a predetermined timing, a predetermined amount of toner 90 is supplied from the developing device 4 to the cleaning nip N3 (for example, from the developing device 4Y to the cleaning nip N3Y) in each process cartridge 8. That is, toner 90a is supplied to the process cartridge 8 containing toner 90a, and toner 90b is supplied to the process cartridge 8 containing toner 90b.

[0198] In the first embodiment, the second toner supply operation is executed according to the travel distance of the surface of the photosensitive drum 1. Specifically, when the integrated value of the travel distance of the surface of the photosensitive drum 1 reaches a predetermined threshold value, the second toner supply operation is executed. Here, the travel distance of the surface of the photosensitive drum 1 is a distance (surface movement distance) that indicates how far a certain point on the surface of the photosensitive drum 1 has advanced (moved) due to the rotation of the photosensitive drum 1. Then, when the second toner supply operation is executed, the integrated value of the travel distance of the surface of the photosensitive drum 1 is reset or decreased, and the accumulation is started again.

[0199] In the first embodiment, the second toner supply operation is performed in a post-rotation process after the image forming operation. In the first embodiment, the threshold value of the travel distance of the surface of the photosensitive drum 1 is set to a travel distance equivalent to 100 sheets of A4 size recording paper with two-sheet intermittent printing. Note that intermittent printing refers to a printing method in which the operation of the developing device 4 is temporarily stopped after a predetermined number of sheets are printed, and then the printing operation is performed again. Also, the determination as to whether the accumulated value of the travel distance of the surface of the photosensitive drum 1 is equal to or greater than the predetermined threshold value is This determination may be made by the control unit 101 or by other known determination means. Furthermore, the determination as to whether or not to execute the second toner supply operation is not limited to the travel distance of the surface of the photosensitive drum 1, and may be made based on other indicators such as the driving time of the photosensitive drum 1.

[0200] In the first embodiment, when the second toner supply operation is performed, a toner image is formed on the surface of the photosensitive drum 1 in the same manner as during the image forming operation. In the first embodiment, a horizontal band is formed on the surface of the photosensitive drum 1, the width of which is 15 mm in the moving direction and 230 mm in the direction of the rotation axis of the photosensitive drum 1. The toner image on the surface of the photosensitive drum 1 is then supplied to the cleaning nip N3 as the photosensitive drum 1 rotates. At this time, a predetermined DC voltage having the same polarity as the normal charging polarity of the toner 90 (negative polarity in the first embodiment) is applied to the primary transfer roller 5. This makes it difficult for the toner image on the surface of the photosensitive drum 1 to be transferred onto the intermediate transfer belt 7 when passing through the primary transfer portion N1.

[0201] In this way, the second toner supply operation periodically supplies the toner 90 to the cleaning nip N3 of the process cartridge 8, thereby maintaining the lubrication of the cleaning blade 61. In particular, the second toner supply operation can supply the toner 90a, which maintains its lubricating effect for a relatively long time, to the cleaning nip N3 of the process cartridge 8 that contains the toner 90a.

[0202] (Third toner supply operation) On the other hand, in the third toner supplying operation, the toner 90a is supplied to the cleaning nip N3 of the process cartridge 8 containing the toner 90b.

[0203] In the first embodiment, the process cartridge 8K containing the toner 90b is provided downstream of the process cartridges 8 (8Y, 8M, 8C) containing the toner 90a in the moving direction Tr of the surface of the intermediate transfer belt 7. By disposing in this manner, the toner 90a can be supplied to the cleaning nip N3 of the process cartridge 8K containing the toner 90b during the image forming operation.

[0204] The third toner supply operation will be specifically described. First, a toner image made of toner 90a formed in the process cartridge 8 (any one or a combination of 8Y, 8M, and 8C) on the upstream side in the moving direction Tr of the surface of the intermediate transfer belt 7 is primarily transferred onto the intermediate transfer belt 7. Then, the toner image reaches the primary transfer portion N1K as the intermediate transfer belt 7 rotates. At this time, a predetermined DC voltage of a polarity opposite to the normal charging polarity of the toner 90a (positive polarity in the first embodiment) is applied to the primary transfer roller 5, so that the toner image on the surface of the intermediate transfer belt 7 is difficult to be collected on the photosensitive drum 1K when passing through the primary transfer portion N1K. However, some of the toner 90a with a low charge amount among the toner 90a images on the surface of the intermediate transfer belt 7 are collected on the photosensitive drum 1K. Due to this action, in the first embodiment, the toner 90a is supplied to the cleaning nip N3 of the process cartridge 8K containing the toner 90b.

[0205] The method of supplying the toner 90a to the process cartridge 8K as the third toner supply operation is not limited to the above-mentioned method. For example, in the post-rotation process of the image forming operation, when the secondary transfer residual toner or the toner discharged by the cleaning operation of the secondary transfer roller 9 and the conductive brush 15 is collected by the photosensitive drum 1, the toner may be set to be collected by the photosensitive drum 1K. Also, for example, at the same timing as the second toner supply operation, an operation of supplying the toner 90a from one of the process cartridges 8 containing the toner 90a to the cleaning nip N3 of the process cartridge 8 containing the toner 90b may be performed. Also, for example, when the integrated value of the travel distance of the surface of the photosensitive drum 1 reaches a predetermined threshold, the third toner supply operation is performed at a timing different from that of the second toner supply operation. It's okay to do that.

[0206] In this manner, in the third toner supplying operation, the toner 90a, which maintains its lubricating effect for a comparatively long period of time, can be supplied to the cleaning nip N3 of the process cartridge 8 containing the toner 90b.

[0207] As described above, the first to third toner supplying operations are each executed at an appropriate timing in the embodiment 1. Fig. 10 is a flowchart summarizing the execution timing of the toner supplying operations in the embodiment 1. Below, the execution timing of the toner supplying operations of the image forming apparatus 100 in the embodiment 1 will be described with reference to the flowchart in Fig. 10.

[0208] First, when the process cartridge 8 is mounted in the apparatus body 111 of the image forming apparatus 100 (S101), a detection unit determines whether the process cartridge 8 is unused (new) or not (S102). If the process cartridge 8 is determined to be new, an initial installation operation including a first toner supply operation is executed (S103). At this time, toner 90b is supplied from the process cartridge 8K to the cleaning nip N3 of the process cartridge 8 determined to be new.

[0209] After the initial setting operation is performed, the image forming operation is started in accordance with the print job (S104). If none of the process cartridges 8 are new (NO in S103), the initial setting operation is not performed, and a predetermined preparation operation is performed before the image forming operation is started. In the first embodiment, the third toner supply operation is performed during the image forming operation (S105). At this time, toner 90a is supplied to the cleaning nip N3K ​​of the process cartridge 8K that contains toner 90b. Thus, in the first embodiment, the third toner supply operation is performed every time an image forming operation is performed.

[0210] When the third toner supply operation is performed and image formation is completed, a post-rotation process is started as part of the image formation operation (S107). In the post-rotation process, it is determined whether or not the accumulated value of the travel distance of the surface of the photosensitive drum 1 is equal to or greater than a predetermined threshold value. If it is determined that the accumulated value is equal to or greater than the threshold value, a second toner supply operation is performed (S106).

[0211] After the second toner supply operation is performed, or if it is determined that the integrated value is less than the threshold value (NO in S107), the post-rotation process ends and the image forming operation ends (S109). When a new image forming operation is started, the same operations as S104 to S109 are performed again. With this configuration, a more suitable toner 90 is supplied to the cleaning nip N3 at any timing, whether immediately after the process cartridge 8 is installed or when the process cartridge 8 is nearing the end of its life, thereby suppressing a decrease in productivity and the generation of abnormal noise.

[0212] <Evaluation experiment> Next, a description will be given of an evaluation experiment conducted to verify the abnormal noise suppression effect of the configuration of Example 1. Prior to the description of the evaluation experiment, a description will be given of Comparative Example 1 and Comparative Example 2, on which the evaluation experiment was conducted.

[0213] [Comparative Example 1] Comparative Example 1 will now be described. The basic configuration and operation of the image forming apparatus 100 of Comparative Example 1 are the same as those of Example 1. Therefore, in the image forming apparatus of Comparative Example 1, elements having the same or corresponding functions or configurations as those of the image forming apparatus 100 of Example 1 are given the same reference numerals as those of Example 1, and detailed descriptions thereof will be omitted.

[0214] In Comparative Example 1, the toner 90 contained in the developing device 4 of each process cartridge 8 was The toner is 90a.

[0215] In Comparative Example 1, the toner supplying process in the initial installation operation is different from that in Example 1. Specifically, in each process cartridge 8, a predetermined amount of toner 90 is supplied from the developing device 4 to the cleaning nip N3 (for example, from the developing device 4Y to the cleaning nip N3Y). In Comparative Example 1, when the toner supplying process is started, the photosensitive drum 1 is exposed by the exposure device 3, and the electrostatic latent image is developed by the toner 90 on the developing roller 42 to form a toner image.

[0216] In Comparative Example 1, a horizontal band having a width of 65 mm in the moving direction of the surface of the photosensitive drum 1 and a width of 230 mm in the direction of the rotation axis of the photosensitive drum 1 is formed as a toner image during the initial installation operation. Then, the toner image on the surface of the photosensitive drum 1 is supplied to the cleaning nip N3 as the photosensitive drum 1 rotates. At this time, a predetermined DC voltage having the same polarity as the normal charging polarity of the toner 90 (negative polarity in Example 1) is applied to the primary transfer roller 5. As a result, the toner image on the surface of the photosensitive drum 1 is less likely to be transferred onto the intermediate transfer belt 7 when passing through the primary transfer portion N1.

[0217] With regard to the above-mentioned Comparative Example 1, Comparative Example 1-1 was a configuration in which the initial installation operation time was 95 seconds, the same as in Example 1, and Comparative Example 1-2 was a configuration in which the initial installation operation time was 207 seconds, longer than in Example 1. In Comparative Example 1-2, in order to suppress the generation of abnormal noise, the developer contact rotation process in the initial installation operation was lengthened to 152 seconds, thereby lengthening the initial installation operation time.

[0218] [Comparative Example 2] Next, a description will be given of Comparative Example 2. The basic configuration and operation of the image forming apparatus 100 of Comparative Example 2 are the same as those of Example 1. Therefore, in the image forming apparatus of Comparative Example 2, elements having the same or corresponding functions or configurations as those of the image forming apparatus 100 of Example 1 are given the same reference numerals as those of Example 1, and detailed descriptions thereof will be omitted.

[0219] In Comparative Example 2, the toner 90 contained in the developing device 4 of the process cartridge 8 is entirely toner 90b.

[0220] In Comparative Example 2, the toner supplying step of the initial setting operation is the same as that of Comparative Example 1. The initial setting operation time is 95 seconds, the same as that of Example 1, in both Comparative Examples 2-1 and 2-2.

[0221] In Comparative Example 2-2, when the process cartridge 8 has been used for a long period of time, the toner supply amount in the second toner supply operation is increased. This is because the toner 90 in the developing device 4 is repeatedly rubbed, and the movement, detachment, and embedment of various organic or inorganic fine powders on the toner surface progresses, and the force of providing lubrication decreases. In Comparative Example 2-2, known development life detection methods such as the travel distance of the developing roller 42, the amount of toner in the developing device 4, and the number of printed sheets can be used alone or in combination. Then, the toner supply amount in the second toner supply operation is determined according to the development life detection result. In Comparative Example 2-2, the toner supply amount is set to be increased by 5 times when the development life remaining is 40% or less, especially in a low-temperature, low-humidity environment in which the movement, detachment, and embedment of various organic or inorganic fine powders on the toner surface progresses.

[0222] In order to confirm the effect of suppressing abnormal noise by the configuration of Example 1, evaluation experiments were conducted including Comparative Examples 1-1, 1-2, 2-1, and 2-2. In the evaluation experiments, evaluation of abnormal noise after initial installation and after long-term use of the process cartridge 8 were conducted. Each evaluation will be described below individually.

[0223] (Evaluation of abnormal noise after initial installation) First, the evaluation of abnormal noise after the initial installation operation will be described. , 8M, 8C, and 8K were prepared, and in an environment with a temperature of 23°C and a relative humidity of 50%, three all-white images were printed intermittently on A4-sized recording paper after the initial setup operation was performed, and the occurrence of abnormal noise was evaluated. In this evaluation, the operation of the developing device 4 was temporarily stopped after printing one sheet, and then the printing operation was performed again. In this evaluation, the initial setup operation time until a new process cartridge 8 reached a standby state (READY state) where it was possible to start image formation operation was also compared.

[0224] The abnormal noise evaluation (occurrence of abnormal noise) was judged according to the following criteria. ○: No abnormal noise, or slight abnormal noise but no practical problem ×: Abnormal noise is noticeable and there is a problem in practical use.

[0225] (Evaluation of abnormal noise after long-term use of process cartridges) Next, the evaluation of abnormal noise after long-term use of the process cartridge will be described. In an environment of 15°C temperature and 10% relative humidity, 4000 sheets of A4 size recording paper were intermittently printed with horizontal line images of 1-2% image ratio, and then three sheets of A4 size recording paper were intermittently printed with all-white images to evaluate the occurrence of abnormal noise. In this evaluation, when printing horizontal line images, the operation of the developing device 4 was temporarily stopped after two sheets were printed in succession, and then the printing operation was performed again, and when printing all-white images, the same evaluation as after the initial installation operation was performed. In this evaluation, the presence or absence of an increase in the amount of toner supplied in the second toner supply operation was also compared.

[0226] The criteria for judging abnormal noise were the same as those for evaluating abnormal noise after the initial installation operation.

[0227] <Evaluation Results> Table 1 shows the results of the abnormal noise evaluation after the initial installation operation and the abnormal noise evaluation after long-term use of the process cartridge for Example 1 and Comparative Examples 1-1, 1-2, 2-1, and 2-2. Table 1 also shows the different operating conditions for each example.

[0228] [Table 1]

[0229] First, the results of the evaluation of abnormal noise after the initial installation operation in Example 1 and each of the comparative examples will be compared.

[0230] In Comparative Example 1-1 and Comparative Example 1-2, toner 90a is supplied to the cleaning nip N3 during the initial setup operation. In Comparative Example 1-1, when the initial setup operation time was the same as in Example 1, abnormal noise occurred during the printing operation after the initial setup operation. In Comparative Example 1-2, when the initial setup operation time was set sufficiently longer than that of Comparative Example 1-1, abnormal noise did not occur. This is because This is because, in order for some of the protrusions 94 formed on the surface of the toner 90a to move and detach from the toner base particles 92, time is required for repeated rubbing with the cleaning blade 61 and the photosensitive drum 1 near the entrance of the cleaning nip N3. That is, if the time for the initial setting operation is short as in Comparative Example 1-1, frictional force increases until some of the protrusions 94 move from the surface of the toner 90a to the cleaning nip N3, and abnormal noise may occur. On the other hand, in Comparative Example 1-2, although abnormal noise did not occur, productivity decreases because the time required for the initial setting operation is long.

[0231] In Example 1, toner 90b is supplied to the cleaning nip N3 during the initial installation operation. As a result, in Example 1, no abnormal noise occurs even if the initial installation operation time is the same as that of Comparative Example 1-1. This is because toner 90b has a higher lubricant supplying ability and a faster lubricating effect than toner 90a. Therefore, compared to the case where toner 90a is supplied to the cleaning nip N3 during the initial installation operation, the occurrence of abnormal noise can be suppressed with a short initial installation operation time in Example 1.

[0232] In Comparative Examples 2-1 and 2-2, the initial setup operation is performed similarly to that in Example 1. That is, in Comparative Examples 2-1 and 2-2, toner 90b is supplied to the cleaning nip N3 during the initial setup operation, so that no abnormal noise is generated and the initial setup operation time is equivalent to that in Example 1.

[0233] Next, the results of the evaluation of abnormal noise after long-term use will be compared between Example 1 and each of the comparative examples.

[0234] In Comparative Example 2-1 and Comparative Example 2-2, in the toner supply after the initial installation operation, only the toner 90b is supplied to the cleaning nip N3. In Comparative Example 2-1, when the toner supply amount was not increased in the second toner supply operation in the latter half of the development life, an abnormal sound occurred during the printing operation after long-term use. This is because the development device 4 was used for a long period of time, and the toner 90b in the development device 4 was repeatedly rubbed, and the movement, detachment, and embedding of various organic or inorganic fine powders on the surface of the toner 90b progressed, and the lubricant supplying ability decreased. On the other hand, in Comparative Example 2-2, when the toner supply amount was increased in the second toner supply operation in the latter half of the development life, no abnormal sound occurred. This is because the supply amount of the toner 90b was increased and a sufficient amount of organic or inorganic fine powder was deposited near the entrance of the cleaning nip N3 to stabilize the supply of the lubricant. However, when the toner supply amount is increased, although the generation of abnormal sound can be suppressed, the toner 90b is excessively consumed, which may cause a disadvantage to the user.

[0235] In the first embodiment, at least the toner 90a is supplied to the cleaning nip N3 in the toner supply after the initial installation operation. As a result, in the first embodiment, even if the toner supply amount is not increased in the second toner supply operation in the latter half of the development life, no abnormal noise occurs. This is because the hemispherical convex portion 94 that has moved and detached from the surface of the toner 90a adheres to and is held on the surface of the cleaning blade 61, thereby maintaining the lubricating effect for a relatively long time. Therefore, in the toner supply after the initial installation operation, compared to the case where only the toner 90b is supplied to the cleaning nip N3, the amount of toner supply is suppressed without excessive toner supply, and the generation of abnormal noise can be suppressed.

[0236] In Comparative Example 1-1 and Comparative Example 1-2, the second toner supply operation is executed similarly to Example 1. That is, in Comparative Example 1-1 and Comparative Example 1-2, in the toner supply after the initial installation operation, toner 90a is supplied to the cleaning nip N3, so that no abnormal noise occurs even if there is no increase in the amount of toner supplied in the second toner supply operation in the latter half of the development life.

[0237] As described above, according to the configuration of the first embodiment, the occurrence of abnormal noise is suppressed while reducing the decrease in productivity caused by the long initial installation operation and the increase in the amount of toner supplied to the cleaning blade 61. It is possible.

[0238] [Example 2] Next, a description will be given of Example 2. The basic configuration and operation of the image forming apparatus 100 of Example 2 are similar to those of Example 1. Therefore, in the image forming apparatus of Example 2, elements having the same or corresponding functions or configurations as those of the image forming apparatus 100 of Example 1 are given the same reference numerals as those of Example 1, and detailed descriptions thereof will be omitted.

[0239] In the first embodiment, the generation of abnormal noise is suppressed by sending toner 90b to the cleaning nip N3 during the initial installation operation, and at least toner 90a after the initial installation operation. However, in a very rare case where printing is performed continuously in a mode in which image formation is performed only by the process cartridge 8K immediately after the initial installation operation (also referred to as the "monochrome mode" here), abnormal noise may be generated. This is because when image formation is performed in the monochrome mode, the photosensitive drums 1Y, 1M, 1C and the developing rollers 42Y, 42M, 42C are separated from each other so that the members of the developing devices 4Y, 4M, 4C of the process cartridges 8Y, 8M, 8C that are not printing are not worn out.

[0240] Since the photosensitive drums 1Y, 1M, and 1C continue to rotate even during image formation in mono mode, the organic or inorganic fine powder accumulated near the entrances of the cleaning nips N3Y, N3M, and N3C on the photosensitive drums 1Y, 1M, and 1C decreases. This is because toner is not supplied to the photosensitive drums 1Y, 1M, and 1C, including during image formation, after the initial installation operation. Then, even if the frictional force between the photosensitive drum 1 and the cleaning blade 61 increases, vibrations cannot be suppressed until the next toner supply, and abnormal noise occurs.

[0241] In order to avoid the generation of abnormal noise in such a case, for example, the start timing of the second toner supply operation after the initial installation operation can be advanced and the image forming operation can be forcibly interrupted to supply toner. However, in that case, the image forming operation is interrupted once to perform the second toner supply operation, which makes the user wait immediately after starting to use the process cartridge 8.

[0242] In the second embodiment, the initial installation operation includes two toner supplying steps, a first initial toner supplying step and a second initial toner supplying step. The first initial toner supplying step is a step of supplying toner 90b to the cleaning nip N3 of the process cartridge 8. The second initial toner supplying step is a step of supplying toner 90a to at least the cleaning nips N3Y, N3M, and N3C of the process cartridges 8Y, 8M, and 8C. This makes it possible to reduce the decrease in productivity of the image forming apparatus 100 and suppress the generation of abnormal noise, even for a user who wishes to perform continuous printing in mono mode immediately after the initial installation operation.

[0243] On the other hand, with regard to the process cartridge 8K, the photosensitive drum 1K and the developing roller 42K come into contact with each other during image formation even when performing continuous printing in monochrome mode, so that the above problem is unlikely to occur.

[0244] <Toner supply during initial installation> The initial installation operation of the second embodiment will be described. In the second embodiment, as described above, the toner supplying process during the initial installation operation of the process cartridge 8 is performed twice, that is, the first initial toner supplying process and the second initial toner supplying process. In other words, in the second embodiment, the first toner supplying operation includes the first initial toner supplying process and the second initial toner supplying process.

[0245] FIG. 11 is a schematic diagram of an initial setup operation in the image forming apparatus 100 according to the second embodiment. In FIG. 11, the horizontal axis indicates time. As an example of the initial setup operation according to the second embodiment, Next, an initial installation operation will be described in the case where it is determined that all of the process cartridges 8Y, 8M, 8C, and 8K mounted in the apparatus main body 111 of the image forming apparatus 100 are unused (brand new).

[0246] When the initial installation operation is started, first, at timing t1, a developing device preparation process similar to that of the first embodiment is performed. Then, in the second embodiment, a first initial toner supply process is performed at timing t2. In the first initial toner supply process, the same operation as the toner supply process in the first embodiment is performed. Specifically, a predetermined amount of toner 90b is supplied from the developing device 4K containing the toner 90b to the cleaning nip N3 of each process cartridge 8. Then, when the first initial toner supply process is completed, at timing t3, a developing contact rotation process similar to that of the first embodiment is performed.

[0247] When the developing contact rotation process is completed, the second initial toner supply process is performed at timing t4. The operation of the second initial toner supply process will be described with reference to Figs. 12(a) and (b). Figs. 12(a) and (b) are explanatory diagrams of the second initial toner supply process of the initial installation operation of the second embodiment. In the second initial toner supply process, unlike the first initial toner supply process, a toner image is formed on the photosensitive drum 1 by the developing device 4 in each of the process cartridges 8Y, 8M, 8C, and 8K.

[0248] 12(a), in the second initial toner supply process of the second embodiment, a toner image is formed on the surface of the photosensitive drum 1 in the same manner as in the image forming operation. That is, an electrostatic latent image is formed by exposing the charged photosensitive drum 1 to laser light Ls from the exposure device 3, and the electrostatic latent image is developed with the toner 90 on the development roller 42 to form a toner image. In the second embodiment, a horizontal band E having a width of 40 mm in the movement direction on the surface of the photosensitive drum 1 and a width of 230 mm in the direction of the rotation axis of the photosensitive drum 1 is formed.

[0249] As shown in FIG. 12(b), the horizontal band E (toner image) on the surface of the photosensitive drum 1 is supplied to the cleaning nip N3 as the photosensitive drum 1 rotates. At this time, a predetermined DC voltage of the same polarity as the normal charging polarity of the toner 90 (negative polarity in the second embodiment) is applied to the primary transfer roller 5. This makes it difficult for the toner image on the surface of the photosensitive drum 1 to be transferred onto the intermediate transfer belt 7 when passing through the primary transfer portion N1. Here, in the second embodiment, toner 90a is supplied to the cleaning nips N3Y, N3M, and N3C of the process cartridges 8Y, 8M, and 8C, and toner 90b is supplied to the cleaning nip N3K ​​of the process cartridge 8K.

[0250] Thereafter, at timing t5, a post-processing process is carried out. In the post-processing process, a post-rotation process (printing completion operation) that is normally carried out after an image forming operation and a cleaning operation for cleaning the toner 90 remaining on the intermediate transfer belt 7 are carried out. When the rear end process is completed, the system enters a standby state (READY state) at timing t6 in which an image forming operation can be started. In the second embodiment, the initial setup operation time was 96 seconds.

[0251] As described above, in the initial installation operation of the second embodiment, first, as in the first embodiment, the toner 90b, which has a high lubricant supplying capability and quickly exhibits a lubricating effect, is supplied to the cleaning nip N3 of the process cartridge 8. Then, the toner 90a, which maintains its lubricating effect for a relatively long time, is supplied to at least the cleaning nips N3Y, N3M, and N3C of the process cartridges 8Y, 8M, and 8C.

[0252] In the second embodiment, the toner 90b is supplied from the developing device 4K to the cleaning nip N3K ​​of the process cartridge 8K in the second initial toner supply step in accordance with the operation of the process cartridges 8Y, 8M, and 8C, but the present invention is not limited to this. Since the photosensitive drum 1K and the developing roller 42K come into contact with each other to perform image formation operations even when continuous printing is performed in mono mode, the process cartridge 8K may be set so that no toner 90 is supplied to the process cartridge 8K in the second initial toner supply step.

[0253] <Reason for supplying different toners in the first initial toner supply process and the second initial toner supply process> Next, in the process cartridges 8Y, 8M, and 8C in the initial installation operation, the reason why toner 90b is supplied to the cleaning nip N3 in the first initial toner supply step, and then toner 90a is supplied in the second initial toner supply step, sandwiching the development contact rotation step, will be explained. Figures 13(a) to (c) are explanatory diagrams of the toner behavior in the vicinity of the cleaning nip N3 in the initial installation operation of the second embodiment. As described above, the cleaning nip N3 is the contact portion between the photosensitive drum 1 and the cleaning blade 61, and in Figures 13(a) to (c), the rotation direction of the photosensitive drum 1 is indicated by an arrow.

[0254] In the initial installation operation of Example 2, similar to Example 1, toner 90b, which has high lubricant supply capability and quickly exhibits its lubricating effect, is supplied to the cleaning nips N3Y, N3M, N3C, and N3K of the process cartridges 8Y, 8M, 8C, and 8K in the first initial toner supply process.

[0255] Thereafter, the developing contact rotation process is performed. Here, as shown in FIG. 13(a), silica particles 90b1 and the like that have moved and fallen off from the surface of the toner 90b accumulate near the entrance of the cleaning nip N3 and enter the cleaning nip N3 to provide a lubricating effect.

[0256] Next, the second initial toner supply process is performed to supply the toner 90a to the cleaning nip N3. As a result, as shown in FIG. 13(b), at least a part of the convex portion 94 formed on the surface of the toner 90a is moved and detached from the toner base particle 92 by the rubbing with the cleaning blade 61. In FIG. 13(b) and (c), the convex portion 94 and other particles that have moved and detached from the toner base particle 92 are shown as detached particles 90a1. The detached particles 90a1 are deposited near the entrance of the cleaning nip N3 together with silica particles 90b1 and the like that have moved and detached from the surface of the toner 90b. Then, they are pushed by the other following detached particles 90a1 (moved and detached convex portion 94) and silica particles 90b1, and some of them are taken into the cleaning nip N3. The captured hemispherical convex portion 94 rolls due to the movement of the surface of the photosensitive drum 1, and the flat portion 94p of the hemispherical convex portion 94 adheres to the surface of the cleaning blade 61 and is held in place. This reduces the contact area between the photosensitive drum 1 and the cleaning blade 61, thereby reducing the frictional force.

[0257] When printing is performed continuously in mono mode immediately after the initial installation operation, image forming operations including toner supply are not performed in the cleaning nips N3Y, N3M, and N3C of the process cartridges 8Y, 8M, and 8C. Therefore, during continuous printing in mono mode, silica particles and the like that have moved and detached from the surface of the toner 90b that had accumulated near the entrance of the cleaning nip N3 gradually decrease. On the other hand, as shown in FIG. 13(c), the toner 90 that has accumulated near the entrance of the cleaning nip N3 is circulated in the direction of the arrow by the movement of the surface of the photosensitive drum 1, and is repeatedly rubbed against the cleaning blade 61. As a result, the convex portion 94 (detached particles 90a1) that has moved and detached from the surface of the toner 90a is further taken into the cleaning nip N3 and adheres to the surface of the cleaning blade 61, so that the lubricating effect is maintained for a relatively long time.

[0258] <Evaluation method> In order to confirm the effect of suppressing abnormal noise by the configuration of Example 2, an evaluation experiment was performed for Examples 1 and 2 and Comparative Example 3. In the evaluation experiment, printing was performed continuously in mono mode immediately after the initial installation operation, and abnormal noise was evaluated.

[0259] In Comparative Example 3, in a first initial toner supply step, toner 90b is supplied to the cleaning nip N3 of the process cartridge 8. Thereafter, after a development contact rotation step, an operation similar to the first initial toner supply step is performed in a second initial toner supply step, and toner 90b is again supplied to the cleaning nip N3. The basic configuration and operation of the image forming apparatus 100 in Comparative Example 3 are the same as those in Example 2.

[0260] The abnormal noise evaluation in the evaluation experiment will be explained. New process cartridges 8Y, 8M, 8C, and 8K were prepared, and in an environment of 23°C temperature and 50% relative humidity, 100 sheets of all-white images on A4 size recording paper were printed continuously in monochrome mode after the initial installation operation, and the number of printed sheets when the abnormal noise occurred was obtained. In this evaluation, the initial installation operation time until the new process cartridge 8 reached a standby state (READY state) where image formation operation can be started was also compared.

[0261] The abnormal noise evaluation was performed for the process cartridges 8Y, 8M, and 8C, which are prone to the above-mentioned problems. The criteria for judging abnormal noise were the same as those for the abnormal noise evaluation after the initial installation operation described in the description of Example 1, and the number of printed sheets at which the abnormal noise was so noticeable that it was judged to be problematic in practical use was obtained as the number of sheets at which abnormal noise occurred.

[0262] <Evaluation Results>

[0263] Table 2 shows the results of noise evaluation during continuous printing of 100 sheets in mono mode for Examples 1 and 2 and Comparative Example 3. Table 2 also shows the operating conditions and the like that differ for each example.

[0264] [Table 2]

[0265] In Example 1, when printing was performed continuously in mono mode immediately after the initial installation operation, an abnormal noise started to occur during the formation of the 43rd image. This is because, in the process cartridges 8Y, 8M, and 8C, no toner was supplied after the initial installation operation, including during the image formation operation. This is because the amount of organic or inorganic fine powder accumulated near the entrance of the cleaning nip N3 decreased, and the frictional force between the photosensitive drum 1 and the cleaning blade 61 increased.

[0266] In Comparative Example 3, abnormal noise began to occur during the formation of the 81st image, and the timing of the abnormal noise occurrence was later than in Example 1. This is because, during the initial installation operation, toner 90b was additionally supplied in the second initial toner supply step after the first initial toner supply step, increasing the amount of organic or inorganic fine powder accumulated near the entrance of the cleaning nip N3. Also, in Comparative Example 3, the increase in the initial installation operation time compared to Example 1 was 3.0 sec, and the decrease in productivity can be suppressed compared to the case where the image formation operation is forcibly interrupted to supply toner.

[0267] In Example 2, even when 100 sheets were printed continuously in mono mode, no abnormal noise was generated. This is because toner 90a, which maintains its lubricating effect for a relatively long time, was supplied to the cleaning nips N3Y, N3M, and N3C in the second initial toner supply process during the initial installation operation. In addition, in Example 2, the increase in the initial installation operation time compared to Example 1 was 1.0 sec, and the decrease in productivity can be suppressed compared to Comparative Example 3.

[0268] As described above, according to the configuration of the second embodiment, even when continuous printing is performed in monochrome mode immediately after the initial installation operation, it is possible to reduce the decrease in productivity of the image forming apparatus 100 and suppress the generation of abnormal noise.

[0269] According to the configurations of the first and second embodiments, by supplying toner 90b from the process cartridge 8 that contains toner 90b to the cleaning nip N3 of the process cartridge 8 that contains toner 90a, it is possible to suppress the decrease in productivity and the generation of abnormal noise. Note that not all of the elements having the functions and configurations of the image forming apparatus 100 described in each embodiment are necessarily required to obtain the above-mentioned effects, and some of the configurations and operations can be modified as appropriate. Therefore, next, modified examples according to the present invention will be described.

[0270] [Variation 1] A description will be given of Modification 1. The image forming apparatus 100 of Modification 1 is similar to the image forming apparatus 100 of the first embodiment except for the points described below.

[0271] In the first modification, the toner 90 contained in the developing devices 4M, 4C, and 4K is designated as toner 90a, and the toner 90 contained in the developing device 4Y is designated as toner 90b. Accordingly, in the first modification, the toner supplying step (first toner supplying operation) of the initial installation operation and the third toner supplying operation are different from those in the first embodiment.

[0272] First, a toner supplying process (first toner supplying process) of the initial installation operation according to the modified example 1 will be described. In the modified example 1, the toner 90b contained in the developing device 4Y of the process cartridge 8Y is supplied to the cleaning nip N3. Figures 14(a) and 14(b) are explanatory diagrams of the toner supplying process of the initial installation operation according to the modified example 1.

[0273] 14(a), when the toner supplying process is started at timing t2, the photosensitive drum 1Y of the process cartridge 8Y containing the toner 90b is exposed to the laser light Ls of the exposure device 3, and an electrostatic latent image is developed by the toner 90b on the developing roller 42Y. Then, a predetermined toner image (horizontal band E) is formed by the toner 90b and is primarily transferred onto the intermediate transfer belt 7. At this time, a predetermined DC voltage of a polarity opposite to the normal charging polarity of the toner 90 (positive polarity in the first modification) is applied to the primary transfer roller 5.

[0274] In the first modification, a total of four horizontal bands E are formed in the toner supply process of the initial installation operation. Specifically, horizontal bands Ea, Eb, Ec, and Ed are formed in this order from the downstream side to the upstream side in the moving direction Tr on the surface of the intermediate transfer belt 7.

[0275] 14(b), at the timing when the leading edge of the horizontal band Ea on the intermediate transfer belt 7 reaches the primary transfer portion N1K, a predetermined DC voltage of the same polarity as the normal charging polarity of the toner 90 (negative polarity in the first modification) is applied to the primary transfer roller 5. In the first modification, the leading edge of the horizontal band Ea reaches the primary transfer portion N1K substantially simultaneously with the leading edge of the horizontal band Eb reaches the primary transfer portion N1C and the leading edge of the horizontal band Ec reaches the primary transfer portion N1M. As a result, the horizontal bands Ea, Eb, and Ec on the intermediate transfer belt 7 are collected on the photosensitive drums 1M, 1C, and 1K, respectively, and are supplied to the cleaning nips N3M, N3C, and N3K as the photosensitive drum 1 rotates. On the other hand, the horizontal band Ed on the photosensitive drum 1Y passes through the primary transfer portion N1Y and is discharged to the cleaning nips N3M, N3C, and N3K. The sheet passes through and is supplied to the cleaning nip N3Y.

[0276] By the above operation, in the first modification, in the initial installation operation, a predetermined amount of toner 90b is supplied to the cleaning nip N3 of each process cartridge 8 from the developing device of the process cartridge containing the toner 90b.

[0277] Next, a third toner supply operation according to the first modification will be described. In the first modification, the toner 90a is supplied to the cleaning nip N3Y of the process cartridge 8Y containing the toner 90b during the image forming operation. Specifically, a toner image of the toner 90a formed in the process cartridge 8 (any one or a combination of 8M, 8C, and 8K) downstream in the moving direction of the surface of the intermediate transfer belt 7 is primarily transferred onto the intermediate transfer belt 7. Then, the toner image reaches the secondary transfer portion N2 with the rotational movement of the intermediate transfer belt 7. The toner 90a (secondary transfer residual toner) remaining on the intermediate transfer belt 7 after the secondary transfer is uniformly scattered by the conductive brush 15 and charged to a polarity opposite to the normal charging polarity of the toner 90. Then, the secondary transfer residual toner charged to a polarity opposite to the normal charging polarity of the toner 90 is transferred to the photosensitive drum 1 at the primary transfer portion N1 and supplied to the cleaning nip N3. In particular, during the image forming operation, the secondary transfer residual toner is collected at the most upstream primary transfer portion N1Y in order to suppress the influence of the secondary transfer residual toner on the image formation. Therefore, in the first modification, the toner 90a is selectively supplied to the cleaning nip N3Y of the process cartridge 8Y that contains the toner 90b.

[0278] The above-described configuration also provides the same effects as those of the embodiment 1. Moreover, the present invention is not limited to this, and no matter which of the developing devices 4Y, 4M, 4C, and 4K contains the toner 90a and the toner 90b, the toner supplying process in the initial installation operation and the toner supplying operation after the initial installation operation may be appropriately set.

[0279] [Variation 2] The image forming apparatus 100 of the second modification is similar to the image forming apparatus 100 of the first embodiment except for the points described below.

[0280] In the second modification, instead of the conductive brush 15, a belt cleaning member 24 as a cleaning means for the intermediate transfer belt 7 is provided on the outer circumferential surface side of the intermediate transfer belt 7. The belt cleaning device including the belt cleaning member 24 is disposed downstream of the secondary transfer portion N2 and upstream of the primary transfer portion (the most upstream primary transfer portion N1Y) in the rotation direction (the moving direction of the surface) of the intermediate transfer belt 7.

[0281] In the second modification, secondary transfer residual toner and adhering matters such as paper powder adhering to the intermediate transfer belt 7 during the secondary transfer are removed and collected from the intermediate transfer belt 7 by the belt cleaning member 24. Also, the belt cleaning member 24 can be placed in a state of contact with the outer circumferential surface of the intermediate transfer belt 7 and in a state of separation by a cleaning member contact / separation mechanism (not shown). In the second modification, the state in which the belt cleaning member 24 is in contact with the outer circumferential surface of the intermediate transfer belt 7 is regarded as a basic state, and separation control of the belt cleaning member 24 is performed by the cleaning member contact / separation mechanism at a predetermined timing.

[0282] In the second modification, when the toner supply process of the initial installation operation is started at timing t2, the belt cleaning member 24 is separated from the outer circumferential surface of the intermediate transfer belt 7 by the cleaning member contact / separation mechanism. Then, when the toner supply process is completed at timing t3 and the development contact / rotation process is started, the belt cleaning member 24 is brought into contact with the outer circumferential surface of the intermediate transfer belt 7 by the cleaning member contact / separation mechanism. With the developing member 24 spaced from the outer circumferential surface of the intermediate transfer belt 7, a predetermined amount of toner 90b is supplied to the cleaning nip N3 of each process cartridge 8 from the developing device 4 of the process cartridge 8 containing the toner 90b.

[0283] In the above configuration, the same effects as those in the first embodiment can be obtained.

[0284] [Variation 3] A description will now be given of Modification 3. The image forming apparatus 100 of Modification 3 is similar to the image forming apparatus 100 of the second embodiment, except for the points described below.

[0285] In the third modification, the toner 90 contained in the developing devices 4Y and 4M is toner 90a, and the toner 90 contained in the developing devices 4C and 4K is toner 90b. In this case, in the first initial toner supply step of the initial installation operation, for example, the toner 90b is supplied from the developing device 4K to the cleaning nips N3Y, N3M, N3C, and N3K of the process cartridges 8Y, 8M, 8C, and 8K in the same manner as in the second embodiment. Then, in the second initial toner supply step, the toner 90a is supplied from the developing devices 4Y and 4M in the process cartridges 8Y and 8M to the cleaning nips N3Y and N3M. Furthermore, in the process cartridges 8C and 8K, the toner 90a is supplied to the cleaning nips N3C and N3K via the intermediate transfer belt 7 from either the process cartridge 8Y or 8M located upstream in the moving direction of the intermediate transfer belt 7 surface.

[0286] The above-mentioned configuration also provides the same effect as in the second embodiment. Moreover, the present invention is not limited to this, and the operations of the first initial toner supply step and the second initial toner supply step of the initial installation operation may be appropriately set regardless of which of the developing devices 4Y, 4M, 4C, and 4K contains the toner 90a and the toner 90b. For example, the toner 90 contained in the developing devices 4C and 4K may be the toner 90a, and the toner 90 contained in the developing devices 4Y and 4M may be the toner 90b. In this case, in the first initial toner supply step of the initial installation operation, for example, the toner 90b is supplied from the developing device 4Y to the cleaning nips N3Y, N3M, N3C, and N3K of the process cartridges 8Y, 8M, 8C, and 8K, as in the first modification. Then, in the second initial toner supply step, the toner 90a is supplied from the developing device 4K to the cleaning nips N3Y, N3M, N3C, and N3K via the intermediate transfer belt 7, as in the first initial toner supply step of the second embodiment.

[0287] The disclosure of this embodiment includes the following configuration. (Configuration 1) A device body, a first cartridge including a first image carrier on whose surface an electrostatic latent image is formed, a first toner container for accommodating a first toner, a first toner carrier for carrying the first toner and developing the electrostatic latent image on the surface of the first image carrier into a toner image, and a first cleaning member for contacting the first image carrier to form a first contact portion, the first cartridge being detachably attached to the main body of the apparatus; a second cartridge including a second image carrier on whose surface a toner image is formed, a second toner container that contains a second toner, a second toner carrier that carries the second toner and develops an electrostatic latent image on the surface of the second image carrier into a toner image, and a second cleaning member that comes into contact with the second image carrier to form a second contact portion, the second cartridge being detachably attached to the device main body; an intermediate transfer body configured to be rotatable and onto which a toner image is transferred from the first image carrier and the second image carrier; a detection means for detecting whether the first cartridge attached to the main body of the apparatus is a new cartridge; Equipped with the first toner has toner particles containing toner base particles and an organosilicon polymer on the surface of the toner base particles, The organosilicon polymer has a structure represented by the following formula (1): the organosilicon polymer forms convex portions on the surfaces of the toner base particles, the second toner has a toner particle surface on which the convex portion is not formed and to which fine powder is externally added; An image forming apparatus comprising: a control unit that executes a first toner supply operation to supply the second toner from the second cartridge to the first contact portion of the first cartridge via the intermediate transfer body when the detection means detects that the first cartridge attached to the device main body is new, and a control unit capable of executing a second toner supply operation to supply the first toner to the first contact portion and the second toner to the second contact portion. R-SiO 3 / 2 (1) (In formula (1), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.) (Configuration 2) A line along the periphery of the surface of the toner base particle is drawn by observing a cross section of the first toner using a scanning transmission electron microscope (STEM), and a horizontal image is obtained by converting the line along the periphery as a reference. When the length of a line along the circumference in a portion where the convex portion and the toner base particle form a continuous interface is defined as a convex width W, the maximum length of the convex portion in a normal direction to the convex width W is defined as a convex diameter D, and the length from the apex of the convex portion to a line along the circumference in a line segment forming the convex diameter D is defined as a convex height H, In the convex portion having a convex height H of 40 nm or more and 300 nm or less, The image forming apparatus according to configuration 1, characterized in that the ratio D / W of the convex diameter D to the convex width W is 0.33 or more and 0.80 or less, that is, the number ratio NR(D / W) of the convex portions is 70% or more by number. (Configuration 3) In a cross-sectional observation of the first toner using a scanning transmission electron microscope (STEM), The width of the horizontal image is the perimeter L, When the sum of the convex widths W of the convex portions of the organosilicon polymer present in the horizontal image, which have a convex height H of 40 nm or more and 300 nm or less, is defined as ΣW, 3. The image forming apparatus according to configuration 2, wherein ΣW / L is 0.30 or more and 0.90 or less. (Configuration 4) 3. The image forming apparatus according to claim 2, wherein the adhesion rate of the organosilicon polymer of the first toner is 80% by weight or more. (Configuration 5) In the image forming apparatus according to configuration 2 or 3, when a cumulative distribution of the convex heights H is taken for the convex portions having a convex height H of 40 nm or more and 300 nm or less, and the convex height H that is integrated from the smallest convex height H and accounts for 80% by number is defined as H80, the H80 is 65 nm or more. (Configuration 6) 6. The image forming apparatus according to any one of configurations 1 to 5, wherein R is an alkyl group having 1 to 6 carbon atoms. (Configuration 7) 7. The image forming apparatus according to any one of Configurations 1 to 6, wherein the fine powder externally added to the second toner has an average primary particle size of 40 nm or less. (Configuration 8) 8. The image forming apparatus according to claim 7, wherein the total amount of the fine powder externally added to the second toner is 0.05 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner. (Configuration 9) 9. The image forming apparatus according to claim 7 or 8, wherein the fine powder is silica particles. (Configuration 10) the fine powder is externally added to the first toner, The image forming apparatus according to any one of configurations 7 to 9, characterized in that the amount of the fine powder added to the second toner is greater than the amount of the fine powder added to the first toner. (Configuration 11) the detection means is configured to be able to detect whether the second cartridge attached to the main body of the apparatus is a new one, The image forming apparatus according to any one of configurations 1 to 10, characterized in that the control unit supplies the second toner to the second contact portion in the first toner supply operation when it detects that the second cartridge attached to the apparatus main body is new. (Configuration 12) The image forming apparatus according to any one of configurations 1 to 11, characterized in that the control unit executes the second toner supply operation when an integrated value of the travel distance of the surface of the first image carrier or an integrated value of the travel distance of the surface of the second image carrier reaches a predetermined threshold value. (Configuration 13) The image forming apparatus according to any one of configurations 1 to 12, wherein the control unit is configured to be capable of executing a third toner supply operation of supplying the first toner to the second contact portion. (Configuration 14) 14. The image forming apparatus according to claim 13, wherein the control unit executes the third toner supplying operation every time an image forming operation is performed. (Configuration 15) The image forming apparatus of configuration 13, characterized in that the control unit executes the third toner supply operation when an integrated value of the travel distance of the surface of the first image carrier or an integrated value of the travel distance of the surface of the second image carrier reaches a predetermined threshold value. (Configuration 16) a transfer member that forms a transfer nip with the intermediate transfer body and nip-conveys a recording material together with the intermediate transfer body; The image forming apparatus of configuration 14 or 15, characterized in that, in the movement direction of the intermediate transfer body, the contact portion between the first image carrier and the intermediate transfer body is located upstream of the contact portion between the second image carrier and the intermediate transfer body and downstream of the transfer nip. (Configuration 17) The image forming apparatus according to any one of configurations 1 to 16, wherein the control unit performs the first toner supply operation in a state in which the first image carrier and the first toner carrier are spaced apart from each other. (Configuration 18) The image forming apparatus described in configuration 17, characterized in that, in the first toner supply operation, the control unit supplies the second toner from the second cartridge to the first contact portion of the first cartridge, and then supplies the first toner to the first contact portion of the first cartridge while the first image carrier and the first toner carrier are in contact with each other. [Explanation of symbols]

[0288] 100: image forming apparatus, 1: photosensitive drum (first and second image carriers), 6: cleaning member (first and second cleaning members), 7... intermediate transfer belt (intermediate transfer body), 8... process cartridge (first and second cartridge), 41... developing container (first and second toner storage container), 42... developing roller (first and second toner carrier), 101... control unit, 104... memory (detection means), 111... apparatus main body

Claims

1. A device body, a first cartridge including a first image carrier on whose surface an electrostatic latent image is formed, a first toner container for accommodating a first toner, a first toner carrier for carrying the first toner and developing the electrostatic latent image on the surface of the first image carrier into a toner image, and a first cleaning member for contacting the first image carrier to form a first contact portion, the first cartridge being detachably attached to the device main body; a second cartridge including a second image carrier on whose surface a toner image is formed, a second toner container for accommodating a second toner, a second toner carrier for carrying the second toner and developing an electrostatic latent image on the surface of the second image carrier into a toner image, and a second cleaning member for contacting the second image carrier to form a second contact portion, the second cartridge being detachably attached to the device main body; an intermediate transfer body configured to be rotatable and onto which a toner image is transferred from the first image carrier and the second image carrier; a detection means for detecting whether the first cartridge attached to the main body of the apparatus is a new cartridge; Equipped with the first toner has toner particles containing toner base particles and an organosilicon polymer on the surface of the toner base particles, The organosilicon polymer has a structure represented by the following formula (1): the organosilicon polymer forms convex portions on the surfaces of the toner base particles, the second toner has a toner particle surface on which the convex portion is not formed and to which fine powder is externally added; An image forming apparatus characterized in that it is provided with a control unit that executes a first toner supply operation to supply the second toner from the second cartridge to the first contact portion of the first cartridge via the intermediate transfer body when the detection means detects that the first cartridge attached to the device main body is new, and a control unit capable of executing a second toner supply operation to supply the first toner to the first contact portion and the second toner to the second contact portion. R-SiO ３／２ (1) (In formula (1), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.)

2. In a horizontal image obtained by observing a cross section of the first toner particle using a scanning transmission electron microscope (STEM), a line was drawn along the periphery of the surface of the toner base particle, and the line was converted based on the line along the periphery. When the length of a line along the circumference in a portion where the convex portion and the toner base particle form a continuous interface is defined as a convex width W, the maximum length of the convex portion in a normal direction to the convex width W is defined as a convex diameter D, and the length from the apex of the convex portion to a line along the circumference in a line segment forming the convex diameter D is defined as a convex height H, In the convex portion having a convex height H of 40 nm or more and 300 nm or less, 2. The image forming apparatus according to claim 1, wherein a ratio NR(D / W) of the convex diameter D to the convex width W is 0.33 or more and 0.80 or less of the number of the convex portions is 70% or more by number.

3. In a cross-sectional observation of the first toner using a scanning transmission electron microscope (STEM), The width of the horizontal image is the perimeter L, When the sum of the convex widths W of the convex portions of the organosilicon polymer present in the horizontal image, which have a convex height H of 40 nm or more and 300 nm or less, is defined as ΣW, 3. The image forming apparatus according to claim 2, wherein ΣW / L is equal to or greater than 0.30 and equal to or less than 0.

90.

4. 3. The image forming apparatus according to claim 2, wherein the adhesion rate of the organosilicon polymer in the first toner is 80% by weight or more.

5. 3. The image forming apparatus according to claim 2, wherein, in the convex portion having the convex height H of 40 nm or more and 300 nm or less, when a cumulative distribution of the convex height H is taken and the convex height H that is integrated from the smallest convex height H and accounts for 80% by number is defined as H80, the H80 is 65 nm or more.

6. 2. The image forming apparatus according to claim 1, wherein R is an alkyl group having 1 to 6 carbon atoms.

7. 2. The image forming apparatus according to claim 1, wherein the fine powder externally added to the second toner has an average primary particle size of 40 nm or less.

8. 8. The image forming apparatus according to claim 7, wherein a total amount of the fine powder externally added to the second toner is 0.05 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner.

9. 8. The image forming apparatus according to claim 7, wherein the fine powder externally added to the second toner is silica particles.

10. the fine powder is externally added to the first toner, 8. The image forming apparatus according to claim 7, wherein the amount of the fine powder added to the second toner is greater than the amount of the fine powder added to the first toner.

11. the detection means is configured to be able to detect whether the second cartridge attached to the main body of the apparatus is a new one, 2. The image forming apparatus according to claim 1, wherein the control unit supplies the second toner to the second contact portion during the first toner supply operation when the control unit detects that the second cartridge attached to the device main body is new.

12. 2. The image forming apparatus according to claim 1, wherein the control unit executes the second toner supply operation when an integrated value of the travel distance of the surface of the first image carrier or an integrated value of the travel distance of the surface of the second image carrier reaches a predetermined threshold value.

13. 2 . The image forming apparatus according to claim 1 , wherein the control unit is configured to be capable of executing a third toner supplying operation for supplying the first toner to the second contact portion.

14. 14. The image forming apparatus according to claim 13, wherein the control section executes the third toner supplying operation every time an image forming operation is performed.

15. The image forming apparatus according to claim 13, characterized in that the control unit executes the third toner supply operation when an integrated value of the travel distance of the surface of the first image carrier or an integrated value of the travel distance of the surface of the second image carrier reaches a predetermined threshold value.

16. a transfer member that forms a transfer nip with the intermediate transfer body and nip-conveys a recording material together with the intermediate transfer body; 15. The image forming apparatus according to claim 14, wherein, in the movement direction of the intermediate transfer body, the contact portion between the first image carrier and the intermediate transfer body is located upstream of the contact portion between the second image carrier and the intermediate transfer body and downstream of the transfer nip.

17. 2 . The image forming apparatus according to claim 1 , wherein the control section executes the first toner supplying operation in a state in which the first image carrier and the first toner carrier are spaced apart from each other.

18. The image forming apparatus according to claim 17, characterized in that, in the first toner supply operation, the control unit supplies the second toner from the second cartridge to the first contact portion of the first cartridge, and then supplies the first toner to the first contact portion of the first cartridge while the first image carrier and the first toner carrier are in contact with each other.

Images