JP3838374B2 - Image forming apparatus - Google Patents

Description

  The present invention belongs to the technical field of image forming apparatuses such as electrostatic copying machines and printers, and in particular, a contact portion between a developing roller of a developing device supported by a rotating body and rotatable and a toner thin layer regulating member is developed. The present invention belongs to the technical field of an image forming apparatus provided with a so-called under-regulated developing device positioned below the rotation center of a roller.

  Conventionally, in an image forming apparatus such as an electrostatic copying machine or a printer, after developing an electrostatic latent image carried on a photosensitive member into a toner image by a developing device, the toner image is transferred to a recording medium such as paper, Further, an image is obtained by fixing the toner image transferred to the recording medium.

  By the way, in the developing device of the image forming apparatus, the toner is conveyed to the photosensitive member by the developing roller for development. However, in order to perform good development, it is necessary to convey an appropriate amount of toner to the photosensitive member. Therefore, conventionally, the toner amount supplied from the supply roller to the developing roller is regulated by the thin layer regulating member and a predetermined toner thin layer is formed on the surface of the developing roller, so that the toner is conveyed to the photosensitive member by the developing roller. Is going.

As a method of regulating the toner layer thickness on the developing roller by such a thin layer regulating member, conventionally, the toner thin layer regulating member is disposed below the rotation center of the developing roller and below the rotation center of the developing roller. There is a so-called under-regulation method for regulating the toner layer thickness by the toner thin-layer regulating member at the position.
In the toner layer thickness regulation method based on the lower regulation, of the toner supplied from the supply roller, excess toner excluding the regulated toner layer thickness is scraped and scraped off by the thin layer regulation member. Excess toner is located below the supply roller and stagnates and accumulates in a space surrounded by the supply roller, the developing roller, and the thin layer regulating member. Then, if excessive toner is overfilled in this space and the space is in a toner compaction state, the toner layer thickness is not properly regulated by the thin layer regulating member, and the toner layer thickness is likely to increase. In addition, the toner in this space can be easily ejected from between the developing roller and the thin layer regulating member, and further, the toner can be easily leaked from the seal portion of the supporting member of the thin layer regulating member.

Therefore, conventionally, a rotatable toner scraping member is provided in the above-described space below the toner supply roller and on the side of the toner layer thickness regulating member, and by rotating the toner scraping member, Japanese Patent Application Laid-Open No. 9-244406 proposes a developing device that scrapes excess toner stored in the space into a toner storage portion of a developing device.
As another method, a recovery path for moving the excess toner stored in the above-described space or the recovered toner from the developing roller into the toner storage space in the developing device is provided, and the recovery path can be rotated. Japanese Patent Application Laid-Open No. 9-305020 discloses a developing device in which a stirring member is provided and the stirring member is rotated so that the toner stored in the space is scraped into the toner storage portion of the developing device via a recovery path. Has been proposed in
In the developing devices disclosed in these publications, by rotating the toner scraping member or the agitating member, excess toner stored in the space is surely scraped from the space.

  However, in the developing device disclosed in any of the above-mentioned publications, it is necessary to provide a special member such as a toner scraping member or a stirring member, and a special rotation drive mechanism for driving the special member to rotate. Is required. For this reason, there is a problem that not only the number of parts is increased and the structure of the developing device becomes complicated and large, but also the cost is increased.

  The present invention has been made in view of such circumstances, and an object of the present invention is to more reliably scrape off excess toner stagnated and stored in the above-described space in a regulated developer. An object of the present invention is to provide an image forming apparatus including a developing device that can be simplified, reduced in weight, reduced in size, and reduced in cost.

  In order to solve this problem, according to the first aspect of the present invention, one of the yellow, magenta, cyan, and black developing devices attached to the rotating body is set to the developing position by rotating the rotating body. A developing device configured to develop a latent image on the photosensitive member by a developing device set at a developing position, and a toner storage device provided outside the developing device and configured to store toner to be supplied to the developing device. A developing roller that develops a latent image on the photosensitive member by rotating at least each of the developing units to convey toner in a toner storage space of the developing units toward the photosensitive member. And a supply roller that rotates to supply toner in the toner storage space to the developing roller, and contacts the developing roller, and is supplied from the supplying roller to the developing roller. In an image forming apparatus comprising a thin layer regulating member that regulates toner and forms a thin layer of a predetermined toner on the surface of the developing roller, each of the developing devices is in a state where it is set at a development position. The contact portion between the developing roller and the thin layer regulating member is set to be lower than the rotation center of the developing roller, and at least one developing device of each of the developing devices in the rotating state of the rotating body. The supply roller is rotated outside the development for at least a predetermined time.

According to the second aspect of the present invention, one of the developing units of yellow, magenta, cyan, and black attached to the rotating body is set to the developing position by rotating the rotating body, and is set to the developing position. A developing device configured to develop the latent image on the photosensitive member by the developing device, and a toner storage device that is provided outside the developing device and stores toner to be supplied to the developing device. Each of the developing units rotates and conveys the toner in the toner storage space of the developing units toward the photoconductor to rotate the developing roller that develops the latent image on the photoconductor. A supply roller that supplies toner in the toner storage space to the developing roller, and a toner that contacts the developing roller and regulates toner supplied from the supply roller to the developing roller. An image forming apparatus comprising a thin layer regulating member that forms a thin layer of a predetermined toner on the surface of the developing roller, wherein the developing roller and the thin layer are in a state where each of the developing devices is set at a developing position. The contact portion with the regulating member is set to be lower than the rotation center of the developing roller, and the supply roller of at least one developing device of the developing device other than the developing position when the rotating body is stopped Is rotated outside the development for at least a predetermined time.
Further, in the invention of claim 3, among the developing devices other than the developing position, the supply roller of at least one developing device of the developing device in which the supply roller is below the rotation center of the rotating body rotates outside the development for at least a predetermined time. It is characterized by letting.

In the image forming apparatus of the present invention configured as described above, the supply roller rotates outside the development for a predetermined time when the rotating body is in the non-developing operation in which the developing operation is not performed or when the developing device is in the non-developing position. Will come to be. As a result, most of the excess toner stagnated and stored in the space surrounded by the developing roller, the supply roller, and the thin layer regulating member is more surely scraped out, and overfilling of the toner in the space is prevented. Therefore, with the simple configuration in which the supply roller is simply rotated outside the development without providing a special toner scraping member, the increase in the toner layer thickness, the ejection of the toner, and the thin layer regulation failure as described above are prevented, and the structure of the developing device In addition, the supply roller is rotated only for a predetermined time, so that toner damage due to the rotation of the supply roller outside the development is suppressed, and deterioration of image quality is suppressed. Is done.

In addition, since the supply roller is rotated outside the development during the non-development operation of all the developing devices, the influence of the load fluctuation generated when the supply roller rotates and the vibration generated at the start / stop are developed. The operation is not given, and good development is performed during the developing operation of the developing device.
Further, since the supply roller can be simply rotated outside the development by a drive source such as a drive motor that rotates the supply roller during the developing operation of the developing device, the drive source is newly provided for rotation outside the development of the supply roller. There is no need to add a driving load torque, and the supply roller can be rotated outside the development with a minimum driving source necessary for the developing operation. In addition, since the sliding load on the thin layer regulating portion and the toner seal portion is reduced by scraping the toner in the space, the driving load torque of the developing device driving source is reduced. Thereby, since energy consumption is suppressed, energy saving is effectively realized.

  According to the image forming apparatus of the present invention, the toner can be easily supplied from the toner storage device provided outside the developing device to the developing device regardless of the position of the developing device. Further, since the toner storage device is not provided in the developing device, the entire developing device can be made small even if the capacity of the toner storing device is large, and the rotation control of the developing device can be performed with high accuracy even when the developing device rotates at high speed. it can. As a result, the image forming apparatus of the present invention can sufficiently and reliably cope with a high speed machine. In addition, toner can be replenished to the developing device via the toner receiving portion regardless of the position of the developing device, so that it is not necessary to move the developing device to the replenishing position one by one, and toner can be replenished efficiently in a short time. Can do.

Further, since the supply roller is rotated outside the development for a predetermined time in the rotation state of the rotating body during the non-development operation where the development operation is not performed or in the non-development position of the developing device, the development roller and the supply roller are thinned. Most of the excess toner stagnated and stored in the space surrounded by the layer regulating member can be scraped out more reliably, and overfilling of the toner in the space can be prevented. Therefore, with the simple configuration in which the supply roller is simply rotated outside the development without providing a special toner scraping member, it is possible to prevent the increase in the toner layer thickness, the ejection of the toner, and the poor regulation of the thin layer as described above. The structure can be simplified, the weight can be reduced, and the cost can be reduced. In addition, since the supply roller is only rotated for a predetermined time, it is possible to suppress toner damage due to the rotation of the supply roller outside the development, thereby reducing the image quality. Can be reduced.

Further, since the developing roller rotates outside the developing operation during the non-developing operation of all the developing devices, the developing operation is affected by the load fluctuation that occurs when the supplying roller rotates and the vibration that occurs at the start / stop. Therefore, good development can be performed during the developing operation of the developing device.
Further, since the supply roller can be simply rotated outside the development by a drive source such as a drive motor that rotates the supply roller during the developing operation of the developing device, the drive source is newly provided for rotation outside the development of the supply roller. There is no need to add a driving load torque, and the supply roller can be rotated outside the development with a minimum driving source necessary for the developing operation. In addition, since the sliding load on the thin layer regulating portion and the toner seal portion can be reduced by scraping the toner in the space, the driving load torque of the developing device driving source can be reduced. Thereby, since energy consumption can be suppressed, energy saving can be effectively realized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a developing device and a photoreceptor in an example of an embodiment of an image forming apparatus of the present invention.
As shown in FIG. 1, the image forming apparatus 1 of this example includes a rotary developing device 2, and the rotary developing device 2 is rotatably supported by a rotary 3 and supported by the rotary 3. , Yellow (Y), magenta (M), cyan (C), and black (K) developing devices 4, 5, 6, and 7. Each of these developing devices 4, 5, 6, and 7 is disposed in the circumferential direction of the rotary 3 in this order in the clockwise direction and at equal intervals, and the developing rollers 4a, 5a, 6a, and 7a, and the supply roller, respectively. 4b, 5b, 6b, 7b, thin layer regulating members 4c, 5c, 6c, 7c for regulating the toner layer thickness of the developing rollers 4a, 5a, 6a, 7a, and the first and second augers 4d, 5d, 6d, 7d; 4e, 5e, 6e, 7e.

In the image forming apparatus 1 of this example, as shown in FIG. 1, in a state where, for example, the yellow developing device 4 is set at the developing position where the developing roller 4a contacts the photosensitive member 8 and performs development, the developing roller 4a with the photoconductor 8 is positioned below the rotation center O of the rotary 3, under regulatory contact portion between the developing roller 4a and the thin layer regulation member 4c is located below the rotation center 4a ₁ of the developing roller 4a It is a developing device.

Then, the rotary 3 rotates counterclockwise as indicated by the arrow α, so that the developing rollers 4a, 5a, 6a, and 7a sequentially contact the photosensitive member 8 in these developing units 4, 5, 6, and 7, respectively. The developing position is set in contact (the yellow developing device 4 is set in the developing position in FIG. 1). When any of the developing devices 4, 5, 6, 7 is located at a position other than the developing position, the developing rollers 4a, 5a, 6a, 7a and the supply rollers 4b, 5b, 6b, 7b are all stopped. When any of the developing devices 4, 5, 6, and 7 is set at the developing position, the developing rollers 4a, 5a, 6a, and 7a and the supply rollers 4b, 5b, 6b, and 7b are rotated together to develop. The toner in the toner storage spaces 4h, 5h, 6h, and 7h, which will be described later, of the devices 4, 5, 6, and 7 is supplied to the developing rollers 4a, 5a, 6a, and 7a by the supply rollers 4b, 5b, 6b, and 7b. A thin toner layer is formed on the surface of the developing rollers 4a, 5a, 6a, and 7a by the thin layer regulating members 4c, 5c, 6c, and 7c, and is conveyed toward the photoconductor 8.
The arrangement order of the developing devices 4, 5, 6, and 7 for each color is arbitrarily set without being limited to the above-described order. However, in the following description, for convenience of explanation, it is assumed that the developing units 4, 5, 6, and 7 are arranged in the order of the above-described colors, that is, in the order of yellow, magenta, cyan, and black in the clockwise direction. To do.

  As shown in FIG. 2, the rotary developing device 2 includes a toner receiving portion 9 that protrudes in the axial direction concentrically with the rotary 3 from one end of the rotary 3, and the toner receiving portion 9 is integrated with the rotary 3. To be rotated. As shown in FIG. 3, the toner receiving portion 9 includes a cylindrical portion 10 that extends in the axial direction concentrically with the rotary 3, and a flange portion 11 that is attached to the rotary 3 provided at one end of the cylindrical portion 10. ing. In the internal space of the cylindrical portion 10, four fan-shaped toner movement paths 13, 14, 15, 16 are defined by a cross-shaped partition wall 12, and these toner movement paths 13, 14, 15, 16 are respectively formed. It is long in the axial direction, the end on the flange part 11 side is opened, and the end opposite to the flange part 11 side is closed. Each of the toner moving paths 13, 14, 15, 16 receives yellow, magenta, cyan, and black toners in order.

  Furthermore, five partition ribs 17, 18, 19, 20, and 21 are provided on the outer peripheral surface of the cylindrical portion 10 to partition and form the outer peripheral surface into four in the axial direction. A yellow toner is introduced into the toner movement path 13 from the outer periphery of the cylindrical part 10 in the partition region of the cylindrical part 10 between the adjacent two partition ribs 17 and 18 by connecting the toner movement path 13 and the outside. Similarly, a toner receiving port 22 is formed. Similarly, in the partition region of the cylindrical portion 10 between the two partition ribs 18 and 19, the toner moving path 14 communicates with the outside so that magenta toner is fed to the outer periphery of the cylindrical portion 10. A toner receiving port 23 to be introduced into the toner moving path 14 from the toner is provided, and the toner moving path 15 and the outside communicate with each other in a partition area of the cylindrical portion 10 between the two partition ribs 19 and 20. A toner receiving port 24 for introducing the toner from the outer periphery of the cylindrical portion 10 into the toner moving path 15 is formed, and the toner moving path 16 is formed in a partition region of the cylindrical portion 10 between the two partition ribs 20 and 21. And communicate with the outside A toner receiving port (not shown) through which toner is introduced into the toner moving path 15 from the outer periphery of the cylindrical portion 10 is formed. Therefore, each toner receiving port is provided with a phase shift of approximately 90 ° counterclockwise in the order of yellow, magenta, cyan, and black toners.

  Further, as shown in FIG. 3, the rotary developing device 2 is provided between the two partition ribs 17, 18 to close the space between the partition ribs 17, 18 to form a toner temporary storage portion 27 described later. A pair of clamp-shaped temporary storage part forming members 25 and 26 are provided. These temporary storage portion forming members 25 and 26 are respectively composed of arc-shaped portions 25a and 26a and connecting flange portions 25b and 25c; 26b and 26c extending from both ends of the arc-shaped portions 25a and 26a, respectively. Then, as shown in FIGS. 1, 4 and 5, the arc-shaped portions 25a, 26a are fitted between the partition ribs 17, 18, and are arranged so as to surround the cylindrical portion 10 between the partition ribs 17, 18. In this state, the connection flange portion 25b on one end side of the temporary storage portion forming member 25 and the connection flange portion 26b on one end side of the temporary storage portion forming member 26 are connected on the other end side of the temporary storage portion forming member 25. The flange portion 25c and the connecting flange portion 26c on the other end side of the temporary storage portion forming member 26 are brought into contact with each other and connected to each other with an appropriate fixing tool such as a bolt or a screw (not shown). The forming members 25 and 26 surround the cylindrical portion 10 in a clamp shape.

Thus, in a state where the pair of temporary storage portion forming members 25, 26 are provided between the partition ribs 17, 18, the outer peripheral surface of the cylindrical portion 10 between the partition ribs 17, 18 and a circle as shown in FIG. A toner temporary storage portion 27 (corresponding to the temporary storage portion of the present invention) of yellow toner is formed between the inner peripheral surface 25a _{1 of the} arc-shaped portions 25a, 26a (the arc-shaped portion 26a and its inner peripheral surface are not shown). The toner temporary storage portion 27 is formed in an annular shape so as to cover the outer peripheral surface of the cylindrical portion 10 between the partition ribs 17 and 18. The toner temporary storage unit 27 is always in communication with the yellow toner moving path 13 through the toner receiving port 22, and yellow toner passes from the toner temporary storing unit 27 through the toner receiving port 22 into the toner moving path 13. It can be introduced. In this case, the inner peripheral surfaces 25a ₁ and 26a _{1 of the} arc-shaped portions 25a and 26a and the butted surfaces 25b ₁ and 25c ₁ ; 26b ₁ and 26c ₁ of the connecting flange portions 25b and 25c; However, a seal member is provided to prevent the toner in the toner temporary storage unit 27 from leaking outside.

  In the state where the temporary storage portion forming members 25 and 26 are provided between the partition ribs 17 and 18, when the toner receiving portion 9 rotates integrally with the rotary 3, the partition ribs 17 and 18 become the temporary storage portion formation members. Rotating and sliding relative to 25,26. The toner in the temporary storage part 27 is also moved to the outside of the temporary storage part forming members 25 and 26 by the sliding contact between the side surfaces of the partition ribs 17 and 18 and the side surfaces of the temporary storage part forming members 25 and 26. Leakage is prevented.

As shown in FIGS. 3 and 4, the arc-shaped portion 25 a of one temporary storage portion forming member 25 is provided with toner detection means 94 that detects the presence or absence of a predetermined amount of toner in the toner temporary storage portion 27. (This toner detecting means 94 is not shown in FIG. 2. Further, the positions of the toner detecting means 94 and the toner receiving port 22 shown in FIG. 3 and the toner detecting means 94 and the toner receiving means shown in FIG. The respective positions of the inlets 22 are shown shifted.) The toner detection means 94 is composed of an optical sensor formed in a U-shape, and optically detects toner present in the U-shaped bifurcated portion of the optical sensor.
A supply pipe 28 for supplying yellow toner is connected to the arc-shaped part 25a of one temporary storage part forming member 25, and the supply pipe 28 is provided in the toner temporary storage part 27 as shown in FIG. Is open.

  For the magenta, cyan and black toners, a pair of temporary storage portions forming members 25 and 26 for the yellow toner and a pair of temporary storage portions forming members 29 and 26 exactly the same as the replenishment pipe 28, respectively. 30; 31, 32; 33, 34 and supply pipes 35, 36, 37 are provided in the same manner as shown in FIG. 2, and the toner detection shown in FIGS. 3 and 4 for yellow toner. The same toner detecting means as the means 94 is provided in the same manner. Accordingly, although not shown, the yellow toner temporary storage portion 27 is covered by the temporary storage portion forming members 29, 30; 31, 32; 33, 34 so as to cover the outer peripheral surface of the cylindrical portion 10 between the partition ribs 18, 19. The magenta toner temporary storage section, the same cyan toner temporary storage section as the yellow toner temporary storage section 27, and the partition rib 20 so as to cover the outer peripheral surface of the cylindrical section 10 between the partition ribs 19, 20. , 21 is formed with a black toner temporary storage portion similar to the yellow toner temporary storage portion 27 so as to cover the outer peripheral surface of the cylindrical portion 10.

  These magenta, cyan, and black toner temporary storage units also move to the magenta toner moving path 14, the cyan toner moving path 15, and the black toner moving through the corresponding toner receiving ports in the same manner as in the case of yellow. The replenishment pipes 35, 36, and 37 are opened in the respective toner temporary storage portions while being always in communication with the path 16.

The outer peripheral surface of each toner temporary storage portion is defined by the inner peripheral surface of the arc-shaped portion of each toner temporary storage portion forming member on the upper side (for example, as shown in FIG. the outer peripheral surface is shown to be defined by the inner peripheral surface 25a ₁ of the arc-shaped portion of the upper toner temporary retention unit formation member 25 of the yellow toner), from the rotation center O of the toner temporary retention unit The distance d ₁ to the outer peripheral surface is smaller than the maximum distance d _{2 of} the toner storage spaces 4h, 5h, 6h, and 7h in which the toner in the developing devices 4, 5, 6, and 7 shown in FIG. (D ₁ <d ₂ ).

This toner storage space will be described. For example, the toner storage space 4h of the yellow developing device 4 is adjacent to the yellow developing device 4 and the partition walls 97 that partition the yellow developing device 4 and the adjacent magenta developing device 5 from each other. A partition wall 98 for partitioning the black developing device 7, a yellow developing roller 4 a, a toner thin layer regulating member 4 c in contact with the yellow developing roller 4 a, and a regulating member supporting the toner thin layer regulating member 4 c A space (a space indicated by an oblique grid in FIG. 6) surrounded by the support member 4f and a toner seal member 4g that contacts the yellow developing roller 4a and seals the yellow toner. That is, the yellow toner storage space 4h is a space for storing yellow toner that is not carried on the developing roller 4a after thin layer regulation by the toner thin layer regulating member 4c. Then, in the yellow developing device 4 of this example, the distance between the position 98a of the partition wall 98 shown by the arrow and the rotational center O is the largest distance d ₂ of the toner storage space 4h in FIG.
Note that the magenta, cyan, and black toner storage spaces 5h, 6h, and 7h are spaces surrounded by the partition walls 99, 100, and the like as in the case of the yellow color.

  By the way, as will be described later, the toner receiving port of the cylindrical portion 10 faces upward, and the toner in the temporary toner storage portion corresponding to the upward toner receiving port passes through the toner receiving port and the corresponding toner moving path. However, at this time, the water level of the toner supplied into the developing device is almost the same as the water level of the toner in the toner temporary storage portion due to the leveling action due to the fluidity of the toner. Become. Therefore, by controlling the water level of the toner in each toner temporary storage unit, the water level of the toner in the developing device at the time of supplying the toner to the developing device is controlled. In that case, the water level of the toner in each toner temporary storage unit, that is, the toner amount is controlled by controlling the rotation of each toner container 42, 43, 44, 45 based on the detection of the presence or absence of toner by each toner detection means. It has come to be.

The maximum water level of the toner in the temporary toner storage unit is controlled to be lower than the uppermost position of the outer peripheral surface of the temporary toner storage unit (that is, the distance d ₁ from the rotation center O to the outer peripheral surface). Therefore, when supplying toner to the developing device, the maximum water level of the toner in the developing device is also regulated to the distance d ₁ or less from the rotation center O, and no more toner is supplied to the developing device. Now, since the maximum distance d ₂ of the toner storage spaces 4h, 5h, 6h, and 7h of the developing units 4, 5, 6, and 7 from the rotation center O is set to be larger than the distance d ₁ , each developing unit is thereby set. The toner is not completely filled in the toner storage spaces 4h, 5h, 6h, and 7h in the developing units so that predetermined toner non-existing spaces are formed automatically and reliably. become. By forming the toner non-existing space, when each developing device is rotated by the rotation of the rotary 3, the newly supplied toner and the remaining old toner are efficiently stirred in each developing device. The toner in each developing device is made uniform, and the ejection of toner from the toner regulating member and the toner seal member of each developing device due to overfilling of the toner is prevented.

  The toner receiving ports of the toner receiving units 9 corresponding to the developing units and the developing units respectively have a toner non-existing space formed by controlling the maximum water level of the toner in each developing unit. Similarly, when the toner receiving port corresponding to the developing unit is positioned above the rotation center O, the toner receiving port is similarly positioned above the rotation center O.

  On the other hand, as shown in FIG. 2, each of the supply pipes 28, 35, 36, and 37 includes a yellow toner container 42 and a magenta toner container in a toner storage unit that stores toner provided outside the developing device 2. 43, a cyan toner container 44, and a black toner container 45 are connected to each other through connection supply pipes 38, 39, 40, and 41.

  Each of the toner containers 42, 43, 44, 45 is the same, and is composed of a resin-made cylindrical container 46 as shown in FIG. 7A, and a spiral rib 47 is integrally formed on the inner peripheral surface thereof. Molded. A handle 48 is provided on one end surface of the cylindrical container 46, and an engagement recess 49 is formed in the center of the other end surface of the cylindrical container 46, and the toner is discharged at a position eccentric from the center of the end surface. A hole 50 is formed. Further, a seal member 51, a shutter member 52, and a shutter pressing member 53 shown in FIG. 7B are fitted on the other end face of the cylindrical container 46 so as to be relatively rotatable. Each of the seal member 51, the shutter member 52, and the shutter pressing member 53 is provided with a toner discharge hole 54 that can communicate with the toner discharge hole 50. Further, a protruding first engaging means 55 is provided on the outer peripheral surface of the other end of the cylindrical container 46, and a protruding second engaging means is also provided on the outer peripheral surface of the shutter member 52. 56 is provided.

  The cylindrical container 46 thus configured is supported by a cylindrical container support member 57 shown in FIG. On the peripheral surface of the container support member 57, slit-shaped axial guide means 58 extending in the axial direction from one open end to the other end, and axially slightly before the other end of the axial guide means 58. A slit-shaped circumferential guide means 59 that branches and extends in the circumferential direction from the guide means 58; an engagement recess 60 provided on the other end side from a branch point of the circumferential guide means 59 of the axial guide means 58; Engagement recesses 61 provided at the end portions of the circumferential guide means 59 are respectively provided. In addition, a predetermined number of circular toner dropping holes 62 are formed on the peripheral surface of the container support member 57.

  Further, an elastic seal member 63 is mounted on the one end opening side of the container support member 57. The elastic seal member 63 prevents rattling due to the rotation of the cylindrical container 46, and the cylindrical container 46 It has a function of cleaning toner adhering to the outer peripheral surface of the container when it is detached from the container support member 57. In addition, a toner receiving member 64 is disposed below the container support member 57, and the toner receiving member 64 prevents the inside of the image forming apparatus 1 from being contaminated with toner.

A shutter member 65 and a seal member 66 are fitted and fixed to the other end of the container support member 57. As shown in FIG. 9B, toner discharge holes 67 and 68 are formed in the shutter member 65 and the seal member 66, respectively, and an annular rib is formed around the toner discharge hole 67 of the shutter member 65. A protrusion 69 is provided. The annular rib-like protrusion 69 is in pressure contact with the peripheral edge of the toner discharge hole 68 of the seal member 66 to prevent leakage of toner passing through the toner discharge holes 67 and 68.
Further, a cylindrical third engaging means 70 is provided in the central portion of the shutter member 65 so as to protrude in the axial direction and concentrically. The third engaging means 70 is a cylindrical container which is a toner container. 46 is engaged in a circumferential direction with an engaging recess 49 of 46.

  A toner storage container 71 is attached to the other end of the container support member 57 so as to be rotatable relative to the container support member 57. As shown in FIG. 9, the toner storage container 71 is open at one end side and is provided with a discharge cylinder 72 at the other end side. The inside of the discharge cylinder portion 72 communicates with the toner storage container 71, and the discharge cylinder portion 72 is provided with a toner discharge hole 73 that communicates the inside and the outside of the discharge cylinder portion 72. Further, a pair of annular seal members 74 and 75 are provided on the outer periphery of the discharge cylinder portion 72 in the circumferential direction with the toner discharge hole 73 interposed therebetween. The discharge cylinder portion 72 is penetrated through the through holes 76 and 77 provided at the ends of the corresponding connection supply pipes 38, 39, 40, and 41 so as to be slidable relative to each other. , 41 is disposed between the pair of annular seal members 74, 75 on the opposite side to the supply pipes 28, 35, 36, 37.

  A shutter member 78 made of a disk plate is fitted and fixed to an opening on one end side of the toner storage container 71, and a toner discharge hole 79 is provided in the shutter member 78. The toner discharge holes 67 and 68 and the toner discharge hole 79 are always aligned in the circumferential direction and communicated with each other in the axial direction. Further, an engaging portion 80 is provided in the central portion of the shutter member 78 so as to protrude in the axial direction and concentrically. The engaging portion 80 is a third cylindrical engagement fixed to the container support member 57. It is fitted to the coupling means 70 and engaged in the circumferential direction. Therefore, when the cylindrical container 46 is rotated about its central axis, the two shutter members 65 and 78 are integrally rotated. Furthermore, the shutter member 78 is provided with an adjustment member 81 so that the toner in the toner storage container 71 flows to the toner discharge hole 79 when the toner discharge hole 79 comes to the respective toner discharge holes 79. .

A rotation shaft 82 is concentrically provided at an end of the discharge cylinder portion 72 opposite to the toner storage container 71, and a drive gear 83 is fitted and fixed to the rotation shaft 82.
Then, the connecting flange 84 provided on the outer periphery of the toner storage container 71 and the connecting flange 96 provided on the outer periphery of the container support member 57 are connected, and the rotating shaft 82 is rotated by the driving force applied to the driving gear 83. Thus, the toner storage container 71 and the container support member 57 rotate together.

  Next, the operation of mounting the cylindrical container 46 on the container support member 57 will be described. Before the cylindrical container 46 is attached to the container support member 57, the first engaging means 55 of the cylindrical container 46 and the second engaging means 56 of the shutter member 52 are aligned in the circumferential direction. The toner discharge hole 50 of the cylindrical container 46 and the toner discharge holes 54 of the seal member 51 and the shutter member 52 are not aligned in the circumferential direction and are not in communication with each other in the axial direction. Therefore, leakage of toner from the cylindrical container 46 is prevented.

  In attaching the cylindrical container 46 to the container support member 57, the handle 48 of the cylindrical container 46 is held, and the first engaging means 55 of the cylindrical container 46 and the second engaging means 56 of the shutter member 52. The cylindrical container 46 is inserted from one end side of the container support member 57 so as to be fitted to the axial guide means 58 of the container support member 57 and is made to enter in the axial direction. Then, when the second engaging means 56 is engaged with the engaging recess 60 as shown in FIG. 10B, the cylindrical container 46 is rotated in the clockwise direction in FIG. The engaging means 55 moves along the circumferential guide means 59. At this time, since the second engaging means 56 is engaged with the engaging recess 60, the seal member 51, the shutter member 52, and the shutter pressing member 53 are all rotated with the rotation of the cylindrical container 46. do not do. Accordingly, relative rotation occurs between these members and the shutter members 65 and 78 on the cylindrical container 46 and the container support member 57 side.

  Then, as shown in FIG. 10B, when the first engagement means 55 engages with the engagement recess 61 at the end of the circumferential guide means 59, the cylindrical container 46 is fixed to the container support member 57 and attached. Is done. When the cylindrical container 46 is mounted on the container support member 57 as described above, as shown in FIG. 10A, the toner discharge hole 50 of the cylindrical container 46, the seal member 51, the shutter member 52, and the shutter pressing member. Each toner discharge hole 54 of 53 and the toner discharge hole 79 on the container support member 57 side are aligned in the circumferential direction, and these toner discharge holes communicate in the axial direction. Therefore, in this state, the toner in the cylindrical container 46 can move to the toner storage container 71.

  Note that some toner leaked from the cylindrical container 46 when the cylindrical container 46 is detached from the container support member 57 passes through the toner dropping hole 62 of the container support member 57 and falls to the toner receiving member 64 and is cylindrical. It adheres to the outer periphery of the container 46. The toner adhering to the outer periphery of the cylindrical container 46 is cleaned by the elastic seal member 63 and accommodated in the toner receiving member 64 when the cylindrical container 46 is pulled out in the axial direction.

Next, the operation of supplying toner to the developing device in the image forming apparatus 1 of this example configured as described above will be described. In the following description of the operation, the operation of yellow toner replenishment will be described for the sake of convenience, but the same applies to other magenta, cyan, and black toner replenishment, and description thereof will be omitted.
If the toner detection means 94 for yellow toner does not detect toner in the yellow toner temporary storage section 27, a yellow toner replenishing motor (not shown) is driven, and the rotational driving force is a container support member 57 for yellow toner. The drive gear 83 is added. Then, the drive gear 83 rotates, and the yellow toner storage container 71, the container support member 57, and the toner container 42 rotate together. As a result, the toner in the toner container 42 is conveyed toward the toner discharge hole 20 by the spiral rib 47, and further passes through the toner discharge holes 50, 54, 67, 68, 79, and the toner storage container 71. Supplied in. At this time, since the yellow toner is loosened by the rotation of the toner container 42, the fluidity thereof is improved and the toner container 71 flows smoothly.

  The toner supplied into the toner storage container 71 further flows into the discharge cylinder 72, and when the discharge cylinder 72 is rotated so that the toner discharge hole 73 faces downward, the yellow toner is discharged from the toner discharge hole 73. The free fall of the connection supply pipe 38 due to gravity. The excessive toner supplied into the toner storage container 71 flows to the toner discharge hole 79 by the adjustment member 81 when the toner discharge hole 79 comes up, and further passes through the toner discharge hole to pass through the toner container. Returned to

The yellow toner that has fallen into the connecting supply pipe 38 further freely falls into each annular toner temporary storage section 27 through the supply pipe 28 of the toner receiving section 9 and is temporarily stored in the toner temporary storage section 27. Is done. When the yellow toner is stored in the toner temporary storage unit 27 until the toner detection unit 94 detects the yellow toner, the yellow toner supply motor is stopped by the toner detection signal from the toner detection unit 94.
On the other hand, when the rotary 3 is rotated by driving the developing device driving motor, the cylindrical portion 10 and the flange portion 11 are also rotated integrally with the rotary 3, and the toner receiving port 22 provided in the cylindrical portion 10 is above the rotation center O. When the toner reaches the position, the yellow toner in the toner temporary storage unit 27 passes through the toner receiving port 22 and falls into the toner moving path 13 for the yellow toner.

  Since the toner that has entered the toner moving path 13 rotates around the rotation center O along with the rotation of the rotary 3, the toner tends to be leveled to a certain level due to its fluidity. 4 moves to the direction of 4 and enters the developing device 4. The toner that has entered the developing device 4 is stirred and circulated by the first and second augers 4d and 4e, respectively, and a part of the toner is supplied toward the supply roller 4b.

  By the way, when the developing operation of the image forming apparatus 1 is performed, among the toners supplied to the developing rollers 4a, 5a, 6a, and 7a by the supply rollers 4b, 5b, 6b, and 7b, the developing rollers 4a, 5a, 6a, and 7a. Excess toner excluding the portion of the toner layer formed on the surface is scraped off by the thin layer regulating members 4c, 5c, 6c, and 7c, respectively. The supply oil rollers 4b, 5b, 6b, and 7b and the thin layer regulating members 4c, 5c, 6c, and 7c are stagnated in the spaces 4i, 5i, 6i, and 7i and stored. When development is repeated, the amount of toner stagnated and stored in the spaces 4i, 5i, 6i, and 7i gradually increases, and excess toner is overfilled in these spaces 4i, 5i, 6i, and 7i and hardly flows. It becomes a compacted state. When the toner is overfilled in the spaces 4i, 5i, 6i, and 7i in this way, the excess toner in the spaces 4i, 5i, 6i, and 7i becomes the developing rollers 4a, 5a, 6a, and 7a and the thin layer regulating members 4c, There is a possibility that the toner may be ejected from the contact portion with 5c, 6c, 7c or the seal portion of the regulating member supporting members 4f, 5f, 6f, 7f or a thin layer regulation failure may occur.

  Therefore, in the image forming apparatus 1 of this example, at least each of the developing devices 4, 5, 6, 7 is necessary when, for example, a predetermined number of times of development is performed while the rotary 3 is rotating. The supply roller of one developing unit is rotated idly (that is, rotated outside the development) not for development for at least a predetermined time. That is, when the rotary 3 is rotated, none of the developing units 4, 5, 6, 7 is set at the developing position, and the developing rollers 4a, 5a, 6a, 7a and the supply rollers 4b, 5b, 6b, 7b Since neither developing operation is performed, the supply rollers 4b, 5b, 6b, and 7b are rotated outside the developing for a predetermined time by using this state, so that they are stagnated in the spaces 4i, 5i, 6i, and 7i. Excess toner is scraped from these spaces 4i, 5i, 6i, and 7i, and the gaps between the supply rollers 4b, 5b, 6b, and 7b and the regulating member support members 4f, 5f, 6f, and 7f and the supply rollers 4b and 5b. , 6b, 7b and the partition walls 97, 98, 99, 100 are moved into the toner storage spaces 4h, 5h, 6h, 7h on the toner supply side. As a result, the toner introduced into the spaces 4i, 5i, 6i, 7i hardly stagnates and recirculates into the toner storage spaces 4h, 5h, 6h, 7h on the toner supply side.

  According to the image forming apparatus 1 of this example, the toner from each toner container 42, 43, 44, 45 provided outside the rotary developing device 2 is related to the position of each developing device 4, 5, 6, 7. Can be replenished without any problems. Since the developing device 2 is not provided with a toner storage device, the toner receiving portion 9 of the developing device 2 can be kept small even if the capacity of the toner storage device is large. As a result, the entire developing device 2 can be reduced in size accordingly. Can be formed. Therefore, even when the developing device 2 rotates at high speed, the rotation control of the developing device 2 can be performed with high accuracy. As a result, the image forming apparatus 1 of this example can sufficiently and reliably cope with a high speed machine. In addition, since the toner can be supplied to the developing devices 4, 5, 6, and 7 via the toner receiving portion 9 regardless of the position of the developing device 2, the developing devices 4, 5, 6, and 7 are supplied one by one. There is no need to move to a position, and toner can be replenished efficiently in a short time.

Further, since the supply rollers 4b, 5b, 6b, and 7b are rotated for a predetermined time during the rotation of the rotary 3, which is a non-development operation in which the development operation is not performed, the inside of the spaces 4i, 5i, 6i, and 7i described above. The toner is almost scraped off by the rotation of the supply rollers 4b, 5b, 6b, and 7b, so that the toner can be prevented from being overfilled in the spaces 4i, 5i, 6i, and 7i. As a result, it is possible to prevent the increase in the toner layer thickness, the ejection of the toner, and the poor regulation of the thin layer as described above with a simple configuration in which the supply roller is simply rotated outside the development. Cost can be reduced, and by rotating the supply rollers 4b, 5b, 6b, and 7b for a predetermined time, toner damage due to the rotation of the supply rollers 4b, 5b, 6b, and 7b can be suppressed, and deterioration in image quality can be reduced. it can.

Further, since all the developing devices perform non-developing rotation of the supply rollers 4b, 5b, 6b, and 7b during non-development operation, load fluctuations and startup that occur when the supply rollers 4b, 5b, 6b, and 7b rotate. / Effects such as vibration generated at the time of stopping are not exerted on the developing operation, and good developing can be performed at the time of developing operation of each of the developing devices 4, 5, 6, and 7.
Further, since the supply rollers 4b, 5b, 6b, and 7b are simply rotated outside the development by a drive source such as a drive motor that rotates the supply rollers 4b, 5b, 6b, and 7b during the developing operation of the developing device. It is not necessary to add a new driving load torque for the development rotation of the supply rollers 4b, 5b, 6b, and 7b, and the supply rollers 4b, 5b, 6b, and 7b are configured with a minimum drive source necessary for the developing operation. Rotation outside development is possible. In addition, in this case, the sliding load of the thin layer regulating portion and the toner seal portion can be reduced by scraping the toner in the spaces 4i, 5i, 6i, 7i, so that the driving load torque of the developing device drive source can be reduced. Thereby, since energy consumption can be suppressed, energy saving can be effectively realized.

In the above example, the supply roller is rotated outside the development while the rotary 3 is rotating. However, the present invention is not limited to this, and the supply roller can be rotated outside the development at another time.
That is, the supply roller of at least one developing device of the developing device other than the developing position may be rotated outside the developing for a predetermined time in a stopped state of the rotary 3 where one developing device is set at the developing position. In this case, it is desirable to rotate the supply roller of at least one developing unit of the developing unit in which the supply roller is below the rotation center O of the rotary 3 for at least a predetermined time out of the developing units other than the developing position. This is because when the supply roller is below the rotation center O of the rotary 3, toner tends to fill the space surrounded by the developing roller, the supply roller, and the thin layer regulating member. This is because the toner in the space can be scraped out more effectively by rotating outside the development.

  Further, in this case, when the developing operation at the developing position is not performed, the supply roller of the other developing device is rotated outside the development, so that the influence of the external rotation of the supply roller on the developing operation is developed. Therefore, it is possible to perform a good developing operation. Other functions and effects in this case are the same as in the above example.

Furthermore, it is possible to set the time when the developing roller rotates outside the development after a predetermined number of continuous printings. In this case, after the developing device that has performed continuous printing is set to the non-developing position, the supply roller is rotated outside the development for at least a predetermined time. When continuous printing is performed in this manner, the amount of toner consumption increases, but excess toner scraped off by the thin layer regulating member is effectively removed from the toner storage space on the toner supply side by the rotation of the supply roller outside the development. Therefore, the toner does not run out during the next development, the density reduction such as fading can be prevented, and good image quality can be obtained even after continuous printing. Other functions and effects in this case are the same as those in the above examples.
Further, the developing roller can be rotated outside the development at the home position where the rotary 3 is stopped in a state where none of the developing units is at the development position.

In the above-described example, the contact portion (that is, the development position) between the developing roller and the photoconductor 8 is set to be positioned below the rotation center of the rotary 3. It is also possible to set so that the contact portion is located above the rotation center of the rotary 3. In this case, it is desirable to rotate the supply roller of the developer located below the rotation center of the rotary 3 outside the development.
In addition, the contact method of the thin layer regulating member to the developing roller may be either an abdominal contact or an edge contacting method, and the thin layer restricting member may be contacted to the developing roller by either the counter method or the trail method. Although the trail method is better, it is preferable because it is more effective. Furthermore, the rotation direction of the supply roller may be either the rotation with the rotation or the opposite rotation at the opposite portion of the developing roller, but the rotation with the rotation is more effective.

  The image forming apparatus of the present invention can be used in an image forming apparatus such as an electrostatic copying machine or a printer, and in particular, includes a developing roller of a developing device that is supported by a rotating body and is rotatable and a toner thin layer regulating member. The present invention can be suitably used for an image forming apparatus including a so-called under-regulated developing device in which the contact portion is positioned below the rotation center of the developing roller.

FIG. 1 is a diagram schematically showing a developing device and a photoreceptor in an example of an image forming apparatus to which the present invention is applied. 1 is a perspective view schematically showing a developing device and a toner supply device in an example of an embodiment of an image forming apparatus of the present invention. FIG. 3 is an exploded perspective view partially showing a toner receiving portion of the example shown in FIG. 2. 2A and 2B show a toner receiving portion of the example shown in FIG. 2, wherein FIG. 2A is a cross-sectional view taken along the line IVA-IVA in FIG. 2B, and FIG. 2B is a vertical cross-sectional view of the toner receiving portion. It is a fragmentary sectional view which follows the V-V line in Fig.4 (a). It is a figure which shows the developing device internal space in the developing device of the developing device shown in FIG. FIG. 2 shows a toner container used in the image forming apparatus of this example, (a) is a perspective view, and (b) is an exploded perspective view showing one end of the toner container. It is a perspective view which shows partially the container support member used for the image forming apparatus of this example. The connection part of the container support member and connection supply pipe | tube used for the image forming apparatus of this example is shown, (a) is a disassembled perspective view, (b) is an enlarged view of the IXB part in (a). FIG. 7A is a perspective view of the toner container shown in FIG. 7 attached to the container support member shown in FIG. 8, and FIG. 7B is a partially enlarged view of the axial guide means and the circumferential guide means of the container support member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Rotary developing device, 3 ... Rotary, 4 ... Yellow developing device, 5 ... Magenta developing device, 6 ... Cyan developing device, 7 ... Black developing device, 4a, 5a, 6a , 7a ... developing roller, 4b, 5b, 6b, 7b ... supply roller, 4c, 5c, 6c, 7c ... toner thin layer regulating member, 4f ... thin layer regulating member supporting member, 4g ... yellow toner seal member, 4h , 5h, 6h, 7h ... toner storage space in the developing device, 8 ... photoconductor, 9 ... toner receiving portion, 42 ... yellow toner container, 42 ... yellow toner container, 43 ... magenta toner container, 44 ... cyan Toner container, 45 ... black toner container, 38,39,40,41 ... connection supply pipe, 46 ... toner container, 57 ... container support member, 94 ... toner detection means, 97,98,99,100 ... partition wall

Claims (3)

One of the yellow, magenta, cyan, and black developing devices attached to the rotating member is set to the developing position by rotating the rotating member, and the latent image of the photosensitive member is set by the developing device set to the developing position. A developing device configured to develop the toner and a toner storage device that is provided outside the developing device and stores toner supplied to the developing device, and each of the developing devices rotates. And a developing roller for developing the latent image on the photosensitive member by transporting the toner in the toner storing space of the developing unit toward the photosensitive member, and rotating the toner in the toner storing space by rotating the developing roller. A supply roller to be supplied to the developing roller; and a toner that contacts the developing roller and regulates toner supplied from the supply roller to the developing roller, In the image forming apparatus and a thin layer regulating member for forming a thin layer of toner,
Each of the developing devices is set so that a contact portion between the developing roller and the thin layer regulating member is below a rotation center of the developing roller in a state where the developing device is set to a developing position.
Furthermore, the image forming apparatus, wherein the supply roller of at least one developing unit of each developing unit is rotated outside the developing for at least a predetermined time in a rotating state of the rotating body. One of the yellow, magenta, cyan, and black developing devices attached to the rotating member is set to the developing position by rotating the rotating member, and the latent image of the photosensitive member is set by the developing device set to the developing position. A developing device configured to develop the toner and a toner storage device that is provided outside the developing device and stores toner supplied to the developing device, and each of the developing devices rotates. And a developing roller for developing the latent image on the photosensitive member by transporting the toner in the toner storing space of the developing unit toward the photosensitive member, and rotating the toner in the toner storing space by rotating the developing roller. A supply roller to be supplied to the developing roller; and a toner that contacts the developing roller and regulates toner supplied from the supply roller to the developing roller, In the image forming apparatus and a thin layer regulating member for forming a thin layer of toner,
Each of the developing devices is set so that a contact portion between the developing roller and the thin layer regulating member is below a rotation center of the developing roller in a state where the developing device is set to a developing position.
Further, an image forming apparatus characterized in that, while the rotating body is in a stopped state, a supply roller of at least one developing device in a developing device other than the developing position is rotated outwardly for at least a predetermined time. 3. The developing roller of at least one developing unit of a developing unit located at a position lower than a rotation center of the rotating body among the developing units other than the developing position is rotated outwardly for at least a predetermined time. The image forming apparatus described.

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