JP2004184439A - Heat radiation device in developing cartridge and developing cartridge equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the heat radiation device of a developing cartridge by which heat generated in the developing cartridge is efficiently radiated. <P>SOLUTION: A developing cartridge 12 is provided with a housing 43, a toner storing part 45 to store toner, a roller 53 to supply a photoreceptor drum 5 with the toner and a gear 137 provided at a rotary shaft made of metal so as to rotate and drive the roller, and the gear is provided with a double structure constituted of an outside part 157 where gear teeth are formed and which is made of resin and an inside part 159 that is positioned on the inside of the outside part and is made of sintered metal, and the rotary shaft 135 of the roller is inserted into and fixed at the inside part 159. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a developing cartridge used in an image forming apparatus such as a laser beam printer and a digital copying machine for storing a toner and developing a latent image formed on a photosensitive drum with the toner. The present invention relates to a structure for radiating the heat generated in the above to the outside.
[0002]
[Prior art]
The structure of a conventional laser beam printer including a rotary developing unit will be described (for example, see Patent Document 1, Patent Document 2, and Patent Document 3). In a laser beam printer including this rotary developing unit, a plurality of developing cartridges containing toners of different colors are set in the rotary developing unit. At the time of printing, while rotating the rotary developing unit, a developing cartridge of a required color is placed adjacent to the photosensitive drum, toner is carried on the latent image formed on the photosensitive drum, and the toner is transferred from the photosensitive drum to the transfer belt. Is transferred to a sheet (printing medium) and fixed.
[0003]
The developing cartridge is provided with a supply roller and a developing roller, and the toner is supplied to the developing roller via the supply roller, and is supplied from the developing roller to the photosensitive drum.
[0004]
The developing cartridge generates heat by frictional heat generated by the rotation of the supply roller and the developing roller and by driving other driving systems. When this heat accumulates in the developing cartridge, the toner is thermally denatured due to a rise in temperature, which adversely affects print quality. In particular, since the developing roller is made of metal, the specific heat is small, the surface tends to be high in temperature, and the toner supplied from the supply roller exists as a thin layer on the surface of the developing roller, so that the toner is easily subjected to thermal denaturation. .
[0005]
[Patent Document 1]
JP-A-2002-268319
[Patent Document 2]
JP-A-10-3248
[Patent Document 3]
JP-A-8-129306
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a heat radiating device in a developing cartridge that can efficiently radiate heat generated in the developing cartridge.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the heat radiating device in the developing cartridge according to the first aspect of the present invention rotates the selected developing cartridge around an axis of rotation in a state in which a plurality of developing cartridges are mounted, thereby forming an image on the selected developing cartridge. In a developing cartridge used in a rotary developing unit adjacent to a photosensitive drum in an apparatus and capable of transferring toner in the developing cartridge to the photosensitive drum, the developing cartridge has a peripheral surface and two end surfaces on both sides of the peripheral surface. A toner storage portion formed in the housing for storing toner, a roller for supplying toner in the toner storage portion to the photosensitive drum, and a housing for rotating the roller. Externally, a gear provided on a metal rotating shaft of the roller, wherein the gear has an outer periphery. It has a double structure composed of a resin outer part on which gear teeth are formed, and a sintered metal inner part located inside the outer part, and the inner part has a rotation of the roller. The shaft is inserted and fixed.
[0008]
According to this aspect, since the heat generated in the developing cartridge is transmitted through the metal rotation shaft of the roller and is radiated from the inner part of the gear, it is possible to prevent the developing cartridge from being excessively heated. . Further, the rotation shaft and the gear can be fixed only by press-fitting the rotation shaft of the roller into the inner portion made of the sintered metal.
[0009]
Further, in the heat dissipation device in the developing cartridge according to a second aspect of the present invention, in the first aspect, a roller for supplying the toner to the photosensitive drum is provided adjacent to the toner container, A developing roller having a supply roller whose rotation shaft is rotatably supported by the two end surfaces, and a peripheral surface that is in contact with the peripheral surface of the supply roller, the rotation shaft of which is rotatably supported by the two end surfaces; It is a roller. According to this aspect, thermal denaturation of the toner thinly carried on the surfaces of the supply roller and the developing roller can be prevented, so that high-quality printing can be realized.
[0010]
In the heat radiating device for a developing cartridge according to a third aspect of the present invention, in the second aspect, the gear having the double structure is a developing roller driving gear for driving the developing roller. It is. Since the surface of the developing roller is made of metal and has a small specific heat, it tends to be high in temperature. By employing such a heat dissipation structure in the drive gear of the developing roller, it is possible to prevent the surface temperature of the developing roller from being overheated, and to reliably transfer the toner to the photosensitive drum.
[0011]
Further, in the heat radiating device for a developing cartridge according to a fourth aspect of the present invention, in the third aspect, the first gear portion and the second gear portion having different diameters are provided on a peripheral surface of the developing roller driving gear. Are formed adjacent to each other in the rotation axis direction, and the inner portion is formed so as to straddle the first gear portion and the second gear portion. According to this aspect, when a resin outer portion of the first gear portion and the second gear portion is molded and then cooled, a phenomenon called “sink” caused by a difference in thickness between the two gear portions when cooling is performed. The inner diameter of the inner portion can be made uniform without being affected, and errors in the outer diameter of the gear hardly occur. Therefore, the accuracy of the bearing portion of the developing roller drive gear and the gear itself is increased, and it is possible to prevent rattling of the rotating shaft of the developing roller and inconsistency in gear meshing due to the "sinking" phenomenon.
[0012]
Further, in the heat dissipation device in the developing cartridge according to a fifth aspect of the present invention, in the first aspect, the gear having the double structure may be formed by insert molding in a state where the inner portion is present. It is characterized by being formed by molding the outer member. According to this aspect, since the form of the inner portion does not change when the outer portion is formed, the accuracy of the bearing portion of the developing roller drive gear can be maintained.
[0013]
Further, a developing cartridge according to the present invention includes the heat radiating device according to any one of the first to fifth aspects. According to this aspect, since the heat in the developing cartridge is radiated to the outside through the heat radiating device, the toner is less likely to be thermally denatured, and high quality printing can be realized.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing an image forming apparatus provided with a heat radiating device in a developing cartridge according to the present invention, FIG. 2 is a perspective view of a rotary developing unit, and FIG. 3 is an upper housing member and a lower housing member. FIG. 4 is a perspective view showing a state in which is opened in the direction of the arrow, and FIG. 4 is a side sectional view of the developing cartridge. FIG. 5 is an explanatory view showing the movement of toner in each developing cartridge when the rotary developing unit is rotated from the state shown in FIG. 5A to the state shown in FIG. . 6A is a front view showing the entire roller supporting frame, FIG. 6B is an enlarged view of the left side portion of the roller supporting frame, and FIG. 6C is a view showing the periphery of the roller end sealing member and the roller supporting frame. 7A shows a state in which the left side of the developing roller in FIG. 3 is broken to support the shaft, and FIG. 7B shows a state in which the right side of the developing roller 55 in FIG. 3 is broken. FIG. 7 is a cross-sectional view illustrating a state where the shaft is supported. FIG. 8 is a perspective view showing a roller supporting frame, and a supply roller and a developing roller supported by the roller supporting frame.
[0015]
In the image forming apparatus 1 to which the present invention is applied, the photosensitive drum 5 is provided in the apparatus main body 3 so as to be rotatable in the direction of arrow 7. Around the photoreceptor drum 5, along a rotation direction 7, a charger 9 as a charging unit, a rotary developing unit 11 for holding a developing cartridge as a developing unit, and a cleaning unit 13 are arranged. The charger 9 is applied with a charging bias from a charging bias circuit (not shown), and can uniformly charge the outer peripheral surface of the photoconductor drum 5.
[0016]
An exposure unit 15 is provided below the rotary developing unit 11, and the exposure unit 15 emits a laser beam L toward the outer peripheral surface of the photosensitive drum 5 charged by the charger 9. The exposure unit 15 scans and exposes the laser beam L onto the photosensitive drum 5 in accordance with image data obtained by developing the image forming command into an image, and forms an electrostatic image corresponding to the image forming command on the photosensitive drum 5. Form a latent image.
[0017]
The electrostatic latent image thus formed is developed by the rotary developing unit 11 with toner. That is, in the present embodiment, the rotary developing unit 11 includes a yellow developing cartridge 12Y, a cyan developing cartridge 12C, a magenta developing cartridge 12M, and a black developing cartridge 12K. Are provided so as to be rotatable around the center. The positions of the developing cartridges 12Y, 12C, 12M, and 12K in the circumferential direction of the developing unit 11 are determined, so that the developing cartridges 12Y, 12C, 12M, and 12K are selectively adjacent to the photosensitive drum 5, and the toner is deposited on the surface of the photosensitive drum 5. Can be supplied. Thus, the electrostatic latent image on the photosensitive drum 5 is visualized with the selected toner color. FIG. 1 shows a state in which the developing cartridge 12 </ b> Y for yellow supplies toner to the photosensitive drum 5. In this specification, when the word “up” or “down” is used for the developing cartridge, the word “left” or “right” is used for the developing cartridge based on the direction of the developing cartridge 12Y in FIG. When used, the orientation of the developing cartridge shown in FIG. 3 is used as a reference.
[0018]
A transfer unit 19 is provided above the rotary developing unit 11 and the cleaning unit 13. The transfer unit 19 includes an intermediate transfer belt 21 wrapped around a plurality of rollers, and a drive unit (not shown) for driving the intermediate transfer belt 21 to rotate. The toner image developed by the developing unit 11 is primarily transferred on the intermediate transfer belt 21 of the transfer unit 19 in the primary transfer area 17. The photosensitive drum 5 remains on the outer peripheral surface of the photosensitive drum 5 after the primary transfer by the cleaning unit 13 at a position rotated from the primary transfer area 17 in the rotation direction indicated by the arrow 7 in FIG. The toner is scraped off.
[0019]
When the color image is transferred to the sheet member S, the color images are formed by superimposing the toner images of the respective colors formed on the photosensitive drum 5 on the intermediate transfer belt 21, and in the secondary transfer area 23, The color image is secondarily transferred onto the sheet member S taken out of the cassette 25. The sheet member S on which the color image has been formed in this manner is conveyed via the fixing unit 27 onto the discharge tray section 29 provided on the upper surface of the apparatus main body 3.
[0020]
Next, the configuration and operation of the rotary developing unit 11 provided in the image forming apparatus 1 of FIG. 1 will be described. As shown in FIG. 2, the rotary developing unit 11 has a rotation shaft 31 at the center, and a support frame composed of four frame elements 33 formed around the rotation shaft 31 at an interval of 90 degrees from each other. 35 is provided fixed to the rotating shaft 31. A storage section 37 is formed between the frame elements 33, and the above-described four-color developing cartridges 12Y, 12C, 12M, and 12K are stored in each storage section 37, and the support frame 33 is fixed by a fixing bracket (not shown). Fixed to. In FIG. 2, only the developing cartridge 12Y is shown for simplification.
[0021]
A drive unit (not shown) is connected to the rotating shaft 31 via a clutch. By driving the drive unit, the support frame 35 is rotated, and any one of the four developing cartridges 12Y, 12C, 12M, and 12K is used. The configuration is such that one developing cartridge can be selectively positioned at a developing position facing the photosensitive drum 5 (the position of the developing cartridge 12Y in FIG. 1).
[0022]
The developing cartridges 12Y, 12C, 12M, and 12K held by the support frame 35 have the same configuration. Therefore, here, the developing cartridges 12Y, 12C, 12M, and 12K are collectively referred to as the developing cartridge 12, and will be described below.
[0023]
In the developing cartridge 12, an upper housing member 41 and a lower housing member 42 are integrally combined to form a housing 43 serving as a main body.
[0024]
As shown in FIG. 3, a toner storage portion 45 for storing toner is formed in the housing 43, and a plurality of inclined stirring pieces 51 for stirring the toner 47 are formed in the toner storage portion 45. Have been. When the rotary developing unit 11 rotates about the rotation shaft 31, the toner 47 drops along the stirring piece 51 so that the toner 47 is stirred in the toner storage unit 45.
[0025]
A supply roller 53 (also referred to as an S roller) having a surface formed of urethane sponge is disposed in the toner storage unit 45 so as to be rotatable with respect to the housing 43 while being supported by a metal rotation shaft 139. Have been. As shown in FIGS. 3 and 4, a developing roller 55 (also referred to as a D roller) is provided outside the supply roller 53 in contact with the supply roller 53 and supported by a metal rotary shaft 135 with respect to the housing 43. It is provided rotatably. When the supply roller 53 rotates in the direction of the arrow (FIG. 4) while carrying the toner 47 stored in the housing 43 on its surface, the developing roller 55 receives the toner 47 from the supply roller 53 on its outer peripheral surface. 4 is rotated at a lower speed than the supply roller 53 in the direction of the arrow in FIG. In this example, the supply roller 53 rotates at 1.5 times the speed of the developing roller 55. Note that a charging bias is applied to the supply roller 53 and the developing roller 55 by a mechanism described later, so that the supply roller 53 and the developing roller 55 can be charged.
[0026]
As shown in FIG. 4, the developing roller 55 rotates while being in contact with the photosensitive drum 5, and the toner 47 carried by the developing roller 55 adheres to the surface of the photosensitive drum 5 at the developing position 39. Thus, the toner 47 is rubbed from the supply roller 53 to the surface of the developing roller 55 to form a toner layer having a predetermined thickness (for example, about 10 μm to 20 μm). Transition.
[0027]
Returning to FIG. 2, a communication hole 61 for allowing the air in the toner storage unit 45 to flow with the atmosphere is formed on the upper surface 57 of the upper housing member 41 that forms the housing 43. A seal 63 having a large number of fine holes formed therein, the size of which passes through but does not allow toner to pass through, is affixed. By providing such an air communication means with the inside of the toner storage portion 45 on the upper surface 57 of the upper housing member 41, when the rotary developing unit 11 rotates about the rotation shaft 31, the toner 47 falls down due to a falling phenomenon. Is pushed out from the communication hole 61, so that the air in the toner container 45 can be replaced.
[0028]
FIG. 5 focuses on the developing cartridges 12C and 12K, and shows the inside of the developing cartridges 12C and 12K when the rotary developing unit 11 rotates from the state shown in FIG. 5A to the state shown in FIG. 5B. The movement of the toner 47 of FIG. Note that the seal 63 is not shown in FIGS. 5A and 5B.
[0029]
In FIG. 5A, the toner 47K in the developing cartridge 12K is located on the lower housing member 42 side, and then when the rotary developing unit 11 rotates to the position shown in FIG. 5B, the toner 47K in the developing cartridge 12K becomes The air moves so as to fall to the upper housing member 41 side, and at this time, the air in the space area 65 in the toner container 45 is expelled from the communication hole 61 by the toner 47K that falls so as to cover from above. .
[0030]
By allowing the air in the toner storage unit 45 to freely flow through the communication holes 61 in this manner, even when the toner 47 in the toner storage unit 45 is being consumed, the inside of the toner storage unit 45 has a negative pressure. Therefore, the pressure in the toner container 45 can always be equal to the atmospheric pressure. Further, even when a heat generation source is present near the toner storage unit 45, it is possible to prevent the air in the toner storage unit 45 from being expanded by the heat from the heat generation source to be in a pressurized state. Therefore, the influence of the pressure in the toner container 45 can be eliminated, and the supply state of the toner from the toner container 45 can be constantly maintained.
[0031]
Next, the peripheral structure of the developing roller 55 in the developing cartridge 12 will be described with reference to FIGS. A roller support frame 75 is fixed to the housing 43 of the developing cartridge 12. The roller support frame 75 is entirely made of metal, and as shown in FIG. 6A, a lower frame portion 77 and side frame portions 79a, 79b formed by bending 90 degrees from both ends of the lower frame portion 77. And an upper frame 83 connected to the upper ends of the side frames 79a and 79b with screws 81. The developing roller 55 can be arranged in a region surrounded by the lower frame 77, the upper frame 83, and the two side frames 79a and 79b.
[0032]
6, a blade fixing frame 85 is attached to the lower frame 77 by a plurality of fixing screws 87. Between the blade fixing frame 85 and the lower frame 77, as shown in FIG. And a blade support plate 89 made of phosphor bronze. A regulating blade 91 made of rubber, a resin member, or the like is affixed to the upper surface on the distal end side of the blade supporting plate 89. The regulating blade 91 acts as a spring return function of the blade supporting plate 89 itself and the blade supporting plate 89. Due to the elastic return action of the backup sponge 93 (see FIG. 4) provided below the leading end of the developing roller 55, the peripheral surface of the developing roller 55 is pressed at a constant pressure over its longitudinal direction.
[0033]
The regulating blade 91 has a function of being charged to the same polarity by the friction of the toner 47 with the toner 47. Thus, the toner charged to a predetermined polarity is supplied to the developing roller 55, and the electrostatic latent image on the photosensitive drum 5 can be developed by the toner 47 on the developing roller 55.
[0034]
Further, the regulating blade 91 has a function of averagely adjusting the toner 47 attached to the peripheral surface of the developing roller 55 so that the thickness finally becomes, for example, about 20 μm. Therefore, in order to make the thickness of the toner 47 in the longitudinal direction of the developing roller 55 uniform, it is necessary that the regulating blade 91 is pressed against the peripheral surface of the developing roller 55 at a constant pressure over the longitudinal direction. Important for 12
[0035]
In order to ensure the averaging of the pressing force of the regulating blade 91 against the developing roller 55, the upper frame portion 83 is added as a component of the roller support frame 75 as described above, and the roller support frame 75 is closed. It is to be.
[0036]
That is, by adopting such a closed loop structure and unitizing the developing roller 55 and the regulating blade 91, the shape retention of the roller support frame 75 is improved. Even if a considerable force is applied to the roller support frame 75 when attaching to or detaching from the 37, the positional relationship between the peripheral surface of the developing roller 55 and the regulating blade 91 hardly changes over its longitudinal direction. Become. As a result, the regulating blade 91 continuously presses the peripheral surface of the developing roller 55 with a constant force over its length direction, so that the distribution of the toner 47 on the peripheral surface of the developing roller 55 Can be prevented, and printing defects such as unevenness of color density can be prevented.
[0037]
Next, a structure for attaching the roller support frame 75 to the lower housing member 42 will be described with reference to FIGS. FIG. 7A shows a state in which the left side of the developing roller 55 in FIG. 3 is broken and the rotary shaft 135 is supported, and FIG. 7B shows a state in which the right side of the developing roller 55 in FIG. FIG. 135 shows a state where 135 is supported.
[0038]
As shown in FIGS. 7A and 7B, the end surfaces 95a and 95b of the lower housing member 42 are formed with a supply roller through hole (not shown) and a developing roller through hole 99, respectively. , 95b are provided with shaft holding members 101a, 101b.
[0039]
Both ends of the rotating shaft 135 of the developing roller 55 are rotatably supported by a shaft holding portion 105 extending from the shaft holding members 101a and 101b into the developing roller through hole 99. As shown in FIG. 7A, two holes 106 slightly smaller than the screw thread of the screw 107 are formed in the left end face 95a of the lower housing member 42, and the screw 107 is forcibly inserted through the washer 108 there. By being screwed in, the left shaft holding member 101a and the left end surface 95a of the lower housing member 42 are fixed. Two holes for screws 107 are also formed on the left side frame portion 79a of the roller support frame 75 at positions matching the holes 106 on the left end surface 95a of the lower housing member 42. It is a fool hole 109 larger than the screw thread of the screw 107, and the screw 107 enters therein.
[0040]
On the other hand, as shown in FIG. 7 (b), the right end face 95 b of the lower housing member 42 is formed with two fool holes 113 larger than the screw thread of the screw 111, and the right side frame of the roller support frame 75. The portion 79b is formed with two screw holes 115 in which female screws for the screws 111 are formed at matching positions. Then, the screw 111 is screwed into the fool hole 113 and the screw hole 115 from the hole formed in the right shaft holding member 101b, so that the right shaft holding member 101b, the right end face 95b of the lower housing member 42, and the right side frame portion. 79b is fixed integrally.
[0041]
As a result of such a configuration, the relationship between the housing 43 and the roller support frame 75 is fixed to each other so that the movement of the housing in the longitudinal direction is restricted on the right side, but is fixed on the left side. Are not fixed to the end surface 95a of the lower housing member, so that both can freely move in the longitudinal direction of the housing without being influenced by each other.
[0042]
The reason for adopting such a configuration is that the resin constituting the housing 43 has a larger coefficient of thermal expansion than the metal constituting the roller support frame 75, and thus the resin constituting the housing 43 expands and contracts between the housing 43 and the roller support frame 75 due to a thermal change. The difference (the difference in expansion and contraction is larger in the housing 43) is to eliminate the influence of such difference in expansion and contraction. That is, since the distortion of the roller support frame 75 due to the difference in expansion and contraction between the housing 43 and the roller support frame 75 can be prevented by adopting the above configuration, the outer peripheral surface of the developing roller 55 provided on the roller support frame 75 can be prevented. , The contact pressure of the regulating blade 91 can be kept constant in the longitudinal direction, and toner supply without unevenness in the longitudinal direction is realized.
[0043]
Although not clearly shown in FIGS. 7A and 7B, the lower housing member 42 is in the most contracted state between the end surface 95 a of the lower housing member 42 and the side frame 79 a of the roller support frame 75. However, it is designed such that a slight gap is formed between them.
[0044]
Next, a structure for preventing the toner 47 from scattering from the toner storage portion 45 in the housing 43 to the outside will be described. As shown in FIG. 4, a scattering prevention seal member 117 is fixed to the upper frame 83 of the roller support frame 75 above the developing roller 55, and the other end of the scattering prevention seal member 117 is connected to a lower housing member. The backup sponge 119 is pressed against the developing roller 55 side. This prevents the toner 47 from scattering from between the developing roller 55 and the upper frame 83 to the outside.
[0045]
Further, a seal member 121 is attached to the inside of the upper frame portion 83 of the roller support frame 75, and the seal member 121 closes a gap between the roller support frame 75 and the lower housing member 42, thereby passing through the backup sponge 119. The scattering of the toner 47 to the outside is prevented.
[0046]
Further, as shown in FIGS. 6C and 8, roller end seal members 123 are in contact with both ends of the peripheral surface of the developing roller 55 to prevent the toner 47 from scattering from the end of the developing roller 55 to the outside. are doing. As shown in a partially enlarged view in FIG. 8, the roller end seal member 123 has a double structure in which an upper low friction function member 125 and a lower powder seal function member 127 are bonded. The upper low-friction function member 125 minimizes the rotational frictional resistance of the contact surface with the developing roller 55, such as Fujilon 7000 (registered trademark) (manufactured by Fujiko Co., Ltd.), and has excellent durability against rotational wear. It is made of material. Further, the lower powder sealing function member 127 is made of a material having an excellent sealing function with respect to powder such as toner, for example, wool felt.
[0047]
The base end side of such a roller end seal member 123 is fixed to the blade support plate 89 or the lower frame portion 77, and the front end side of the roller end seal member 123 is supported by the lower housing member 42 from below. However, they are not fixed to the lower housing member 42 and are free ends.
[0048]
By setting the leading end side of the roller end seal member 123 as a free end, the contact state between the peripheral surfaces of both ends of the developing roller 55 and the roller end seal member 123 changes slightly with time. It can be avoided that only the same portion is worn down in a groove shape and the sealing performance is reduced.
[0049]
Next, a driving mechanism of the supply roller 53 and the developing roller 55 will be described with reference to FIGS. FIG. 9 is a side view of a developing cartridge showing a driving system of a supply roller and a developing roller. FIG. 10 is a partial perspective view of the developing cartridge showing a driving system of a supply roller and a developing roller. FIG. 12 is a front view showing a right end surface of the cartridge, and FIG. 12 is a cross-sectional view taken along a longitudinal axis of a rotation shaft of the idle gear.
[0050]
In FIG. 9, reference numeral 129 indicates a rotary gear, and the rotary gear 129 is provided by being inserted into a pin 128 (see FIG. 2) formed inward from the end face of each storage section 37 of the rotary developing unit 11. The rotary gear 129 is connected to a drive source (not shown), and transmits a driving force to a supply roller and a developing roller via an idle gear 131 described later.
[0051]
As shown in FIG. 9, the rotary gear 129 meshes with an idle gear 131 which is an adjacent intermediate gear, and the idle gear 131 is connected to the right end face 130 of the housing 43 of the developing cartridge 12 (the end face located on the right side in FIG. 3). ) Is rotatably provided with respect to a support shaft 133 fixedly provided. The idle gear 131 also meshes with a developing roller driving gear 137 provided on a rotating shaft 135 of the developing roller 55, and the developing roller driving gear 137 is connected to a supplying roller driving gear 141 provided on a rotating shaft 139 of the supplying roller 53. Is meshed with.
[0052]
The developing roller drive gear 137 is composed of two gear parts, a first gear part 143 located outside and having a helical gear form, and a second gear part 145 located inside and having a spur gear form. ing. The second gear portion 145 is adjacent to the first gear portion 143 and has a slightly smaller outer diameter than the first gear portion 143. As shown in FIG. 9, grease 138 is supplied above a portion where the idle gear 131 and the developing roller driving gear 137 mesh with each other. I'm going to go to gear. The grease may be provided at a position above a portion where the other gears mesh with each other.
[0053]
The idle gear 131 has a form of a helical gear that can mesh with the first gear portion 143 of the developing roller drive gear 137, and the rotary gear 129 also has a form of a helical gear that can mesh with the idle gear 131. Have. On the other hand, the supply roller drive gear 141 is in the form of a spur gear, and meshes with the second gear portion 145 of the developing roller drive gear 137.
[0054]
The direction of the teeth of the helical gears of the idle gear 131 and the first gear portion 143 of the developing roller drive gear 137 is such that when each gear rotates in the direction shown by the arrow in FIG. The direction is such that it is biased in the direction. By employing a helical gear for the drive mechanism of the supply roller 53 and the developing roller 55, the developing roller 55 is urged in the direction shown by the arrow 147 to position the developing roller 55 in the longitudinal direction. . As a reaction of such an urging force, the idle gear 131 tends to be urged in a direction indicated by an arrow 149. As a result, the support shaft 133 of the idle gear is moved to the right side of the housing 43 which is softened by frictional heat of gears and the like. The end face 130 is pushed inward and deformed.
[0055]
Therefore, as shown in FIG. 11, as a deformation preventing device, a pressure distribution plate 151 that contacts the outer surface of the right end surface 130 of the housing 43 and contacts the outer surface of the end surface 130 of the housing with an area sufficiently larger than the cross section of the support shaft 133. Is provided. This disperses the stress applied to the support shaft 133 of the idle gear to the pressure distribution plate 151, thereby preventing the right end surface 130 of the housing 43 from being deformed.
[0056]
More specifically, as shown in FIG. 12, a pressing portion 153 having a flange-like enlarged diameter from the supporting shaft 133 is integrally formed near the center of the supporting shaft 133 of the idle gear. An idle gear 131 is rotatably provided outside. The base end side of the support shaft 133 of the idle gear penetrates the right end face 130 of the housing 43 and is fixed to the end face 130 by a nut 155. The pressure distribution plate 151 is, for example, a metal plate plate having a hole through which the support shaft 133 penetrates, and is provided so as to be sandwiched between the pressing portion 153 and the outer surface of the right end surface 130 of the housing 43. ing. Accordingly, when a load is applied to the support shaft 133 of the idle gear in the direction indicated by the arrow 149, the pressing portion 153 presses the pressure distribution plate 151, and the pressure distribution plate 151 is supported by a wide area of the right end surface 130 of the housing 43. Thereby, the deformation of the end face 130 is prevented.
[0057]
The shape and size of the pressure distribution plate 151 can be appropriately determined according to the load applied to the support shaft 133 of the idle gear so that the right end surface 130 of the housing 43 is not deformed. Further, the pressing portion 153 does not need to be formed integrally with the support shaft 133, and the ring-shaped pressing portion 153 may be made to penetrate the conventional support shaft 133 and fixed with a pin or the like. Further, the pressure distribution plate 151 can be directly fixed to the support shaft 133 without using the holding portion 153.
[0058]
Next, the peripheral structure of the developing roller 55 will be described with reference to FIGS. 13 is a longitudinal sectional view showing the inside of the developing roller driving gear, FIG. 14 is a perspective view showing the right side portion of the developing cartridge, and FIG. 15 is a perspective view showing the structure around the low friction member. FIG. 16 is a perspective view showing a state in which a low friction member is provided on the right end face of the developing roller, and FIG. 17 is a front view showing the relationship between the contact regulating roller and the photosensitive drum.
[0059]
As shown in FIG. 13, the developing roller driving gear 137 includes an outer portion 157 in which the first gear portion 143 and the second gear portion 145 are formed with a step, and an inner portion supporting the rotating shaft 135 of the developing roller. 159. An outer portion 157 of the developing roller drive gear 137 is formed of resin, and an inner portion 159 is formed of sintered metal. The sintered metal inner portion 159 is formed so as to straddle the first gear portion 143 and the second gear portion 145. By adopting such a structure, the heat generated in the developing cartridge 12 is transmitted to the rotating shaft 135 of the developing roller and is radiated from the inner portion 159 of the developing roller driving gear 137. Heating can be prevented.
[0060]
When the developing roller drive gear 137 having such a configuration is formed, the inner member 159 made of a sintered metal is prepared, and the outer member 157 is formed by insert molding in a state where the inner member 159 made of the sintered metal is present. Mold. In a conventional method of forming a gear having two stepped gear portions from only resin, a recessed portion called “sink” is formed at a boundary portion due to a difference in thickness of the two gear portions during cooling after molding. This affects the accuracy of the bearing and the accuracy of the outer edge of the gear. However, as described above, the inner member 159 made of sintered metal is formed so as to straddle the first gear portion 143 and the second gear portion 145, and only the outer portion 157 is resin-molded. Such a “sink” phenomenon does not occur at the boundary between the first gear portion 145 and the second gear portion 145.
[0061]
Accordingly, the accuracy of the bearing portion of the developing roller driving gear 137 is improved, and the rattling of the rotating shaft 135 of the developing roller can be prevented. As a result, the accuracy of the outer edge of the developing roller driving gear 137 is increased, so that the driving of the developing roller is stabilized. It will be. Also, by forming the inner portion 159 of a sintered metal, there is an advantage that the shaft can be easily press-fitted.
[0062]
As described above, the gear has a double structure of a metal inner member and a resin outer member, and the heat in the developing cartridge is radiated from the inner member through a shaft attached to the inner member. In addition to the drive gear 137, the present invention can be similarly applied to the supply roller drive gear 141, the idle gear 131, and the rotary gear 129.
[0063]
As shown in FIG. 17, a contact regulating roller 69 having a diameter slightly larger than that of the developing roller 55 is provided at both ends of the rotating shaft 135 of the developing roller 55 so as to be rotatable with respect to the rotating shaft 135. In FIG. 1, when the rotary developing unit 11 rotates and, for example, the developing cartridge 12Y for yellow approaches the photosensitive drum 5, the peripheral surfaces of the two contact regulating rollers 69 of the developing cartridge 12Y collide with the photosensitive drum 5. The distance between the peripheral surface of the developing roller 55 and the peripheral surface of the photosensitive drum 5 is defined as a predetermined distance. Although the predetermined distance is drawn relatively large in FIG. 17, it is actually a very small distance of 1 mm or less.
[0064]
As shown in FIG. 15, on the bottom side of the lower housing member 42, a contact structure is formed when the developing roller 55 is urged toward the developing roller drive gear 137 side. That is, the lower housing member 42 is formed with a support portion 161 for supporting the rotating shaft 135 of the developing roller 55 and a contact portion 163 located on the left side of the support portion 161 with an interval. A roller receiving portion 165 is formed between the contact contact portion 163 and the right contact control roller 69.
[0065]
On the left side of the contact portion 163, that is, on the side of the developing roller 55, a ring-shaped low friction member 167 is provided so as to penetrate the rotation shaft 135 of the developing roller, and the low friction member 167 is in contact with the right end face of the developing roller 55. It is located in a state of being sandwiched between the contact portion 163. When the developing roller 55 is rotated by the driving of the drive mechanism and the developing roller 55 is urged toward the driving gear by the action of the helical developing roller driving gear 137, the right end surface of the developing roller 55 is a low friction member. 167 is pressed by the contact portion 163 with the 167 therebetween.
[0066]
Therefore, frictional heat generated between the end surface of the developing roller 55 and the low friction member 167 and between the low friction member 167 and the contact portion 163 is reduced, so that overheating in the developing cartridge 12 can be prevented and overheating can be prevented. Accordingly, the softening deformation of the contact portion 163 can be prevented. Further, since the deformation of the contact portion 163 is prevented, the positioning of the developing roller 55 in the longitudinal direction is ensured, and the positioning of the entire developing cartridge 12 is also ensured. Further, since the end surface of the developing roller 55 and the contact portion 163 do not directly come into frictional contact with each other, it is possible to prevent the end surface of the developing roller 55 and the contact portion 163 from being worn by the rotation of the developing roller 55.
[0067]
As a specific example of the low friction member 167, Poly Slider (registered trademark) can be given. However, in addition to this, a conventionally known material having a low friction coefficient and abrasion resistance can be used as the low friction member 167.
[0068]
Next, the structure of the left end of the developing cartridge 12 (the end opposite to the developing roller driving gear 137) and the operation of the structure will be described with reference to FIGS. FIG. 18 is a perspective view of the left end side end cover of the developing cartridge as viewed from the back side, FIG. 19 is a perspective view showing a state in which the left end of the developing cartridge is provided with an end cover, and FIG. FIG. 9 is an explanatory diagram showing a state when a developing roller approaches a photosensitive drum during development.
[0069]
As shown in FIG. 19, an end cover 169 is provided at the left end of the developing cartridge 12. The end cover 169 is formed substantially in the shape of a fan so as to conform to the shape of the left end of the developing cartridge 12. An elongated hole 171 is formed near the corner of the fan, and protrudes near both ends of the fan toward the developing cartridge 12. Two press-fit projections 173 (see FIG. 18) are formed. A hole 175 is formed in the vicinity of one press-fit projection 173.
[0070]
On the other hand, two screw holes 172 and 174 are formed at the left end of the developing cartridge 12. A screw 176 is screwed into the screw hole 174 through the long hole 171, and the screw hole 172 is inserted through the hole 175. The end cover 169 is attached to the left end of the developing cartridge 12 by screwing the screw 178 into the left end. The end cover 169 is not rigidly fixed by the screws 176, 178. That is, the screws 176 and 178 are provided so that the developing cartridge 12 can swing around the screw 178 provided in the hole 175 in a range where the screw 176 contacts both ends of the long hole 171.
[0071]
With such a configuration, the developing roller 55 can swing about the right end, so that when the rotary developing unit 11 rotates, the developing cartridge 12 approaches the photosensitive drum 5, as shown in FIG. First, the developing roller 55 approaches the photosensitive drum 5 in a state of being slightly inclined by the action of guide means (not shown) such as a cam, and then gradually approaches the photosensitive drum 5 as shown in FIG. Will be positioned in parallel. When the developing roller 55 approaches the photosensitive drum 5 in this manner, the positional relationship between the developing roller 55 and the photosensitive drum 5 is finally more accurately determined.
[0072]
As shown in FIG. 2, a terminal press-fit portion 177 is formed at the end of each frame element 33 in the support frame 35, and an inside press-fit portion 179 is formed inside each terminal press-fit portion 177. When the developing cartridge 12 is mounted on the support frame 35, the developing cartridge 12 is slid in the longitudinal direction with the developing cartridge 12 disposed in the storage portion 37, and the two press-fitting projections 173 (FIG. 18) of the developing cartridge 12 are respectively moved to the ends. The press-fit portion 177 and the inner press-fit portion 179 are pressed. As a result, the developing cartridge 12 is fixed to the support frame 35.
[0073]
Next, a specific configuration of the contact regulating roller 69 will be described with reference to FIGS. FIG. 21 is an enlarged perspective view of the contact regulating roller, FIG. 22 is a longitudinal section of the contact regulating roller, and FIG. 23 is a cross-sectional view showing another embodiment of the contact regulating roller.
[0074]
As described with reference to FIG. 17, the contact-regulating rollers 69 are provided rotatably with respect to the rotation shaft 135 of the developing roller, and when the rotary developing unit 11 rotates, the peripheral surfaces of the two contact-regulating rollers 69. Collides with the photosensitive drum 5 and regulates the distance between the peripheral surface of the developing roller 55 and the peripheral surface of the photosensitive drum 5 to a predetermined distance.
[0075]
As shown in FIG. 21, the contact regulating roller 69 is formed integrally with a roller body 181 formed in a cylindrical shape, and at the center of the roller body 181, the diameter of which is increased in a disk shape from the outer peripheral surface of the roller body 181. And a roller operating portion 183. An inner protrusion 185 is formed on the inner peripheral surface of the abutment regulating roller 69 so as to protrude inward from a position corresponding to the inside of the roller operating portion 183 and located at the center in the rotation axis direction. ing.
[0076]
By adopting such a configuration, a portion where the rotating shaft 135 of the developing roller is in sliding contact with the contact regulating roller 69 is narrowed, so that the contact regulating roller 69 is easily rotated around the rotating shaft 135.
[0077]
The inner peripheral surface of the inner protrusion 185 is a portion that substantially supports the rotating shaft 135 of the developing roller, and the rotating shaft 135 of the developing roller contacts only the inner peripheral surface of the inner protrusion 185, and It does not contact the other inner peripheral surface 187. Since the inner protrusion 185 is formed inside the roller working portion 183, when the roller working portion 183 is in contact with the photosensitive drum 5, the pressing force is directly applied to the inner protrusion 185. The rotation shaft 135 of the developing roller can be supported.
[0078]
Also, since the inner peripheral surface 187 of the roller main body 181 other than the inner protrusion 185 is configured to be recessed by one step as viewed from the inner protrusion 185, the rotation shaft 135 of the developing roller is exposed as shown in FIG. When inclined with respect to the body drum 5, a space where the rotation shaft 135 of the developing roller can be inclined can be provided on both sides of the inner protrusion 185. Thus, at the initial stage (see FIG. 20A) where the developing roller 55 approaches the photosensitive drum 5, even if the rotating shaft 135 of the developing roller is inclined, the rotating shaft 135 is It is possible to avoid a situation in which the user cannot enter the inner peripheral surface 187 and cannot leave the state.
[0079]
Further, as a result of the formation of the inner protrusion 185, the portion becomes thicker. As a result, the “sink” phenomenon that can occur in the step of resin molding and cooling the configuration in which the roller working portion 183 protrudes outward from the roller main body 181 is less likely to occur. . Further, since the inner protrusion 185 has a smaller diameter and a smaller width than other inner circumferences, it can be formed with high accuracy.
[0080]
As shown in FIG. 22, the inner protrusion 185 has a width W and a height H, and dimensions B on both sides of the inner protrusion 185 on the inner peripheral surface of the roller body 181 are set to be equal to each other. As described above, the width W, the height H, and the dimension B of the inner protrusion 185 are set at the initial stage when the developing roller 55 approaches the photosensitive drum 5 in a slightly inclined state, as shown in FIG. As shown in the figure, the dimensions are set such that the rotation shaft 135 of the developing roller does not contact the inner peripheral surface 187 of the roller main body 181 when it is inclined with respect to the photosensitive drum 5. As an example of such dimensions, the width W of the inner protrusion 185 is 5.0 mm, the height H is 0.3 mm, and the dimension B is 2.2 mm.
[0081]
Due to the presence of the portion corresponding to the dimension B on both sides of the inner protrusion 185 on the inner peripheral surface of the roller main body 181, that is, the extension provided with reference numeral 187, the left and right balance of the inner protrusion 185 is improved. When the contact-regulating roller 69 rotates, the centering action centering on the inner protrusion 185 is improved, and the state in which the contact-regulating roller 69 abuts on the photosensitive drum 5 vertically, that is, the state of good posture, is stabilized. Can be maintained.
[0082]
As shown in FIG. 23, a part of the contact regulating roller 69 can be changed. That is, in the embodiment shown in FIG. 23A, the cross section of the peripheral surface 189 of the roller acting portion 183 is formed in an arc shape so as to protrude outward. According to such an embodiment, since the contact area between the roller acting portion 183 and the photosensitive drum 5 is reduced, the contact resistance is reduced, and the rotation of the contact regulating roller 69 is improved. Further, in the embodiment shown in FIG. 23B, the inner peripheral surface 191 of the inner projection 185 is formed in an arc shape so that the cross section thereof protrudes inward. According to such an embodiment, since the contact area between the inner peripheral surface 191 of the inner protrusion 185 and the rotating shaft 135 of the developing roller is reduced, the contact resistance is reduced, and the rotation of the contact regulating roller 69 is improved. . When the inner peripheral surface 191 of the inner protrusion 185 is formed in an arc shape, the curvature of the inner peripheral surface 191 is such that the rotating shaft 135 is fixed to the roller main body 181 even if the rotating shaft 135 of the developing roller is inclined. It is set so as not to contact the other inner peripheral surface 187.
[0083]
Next, a configuration in which a charging bias is applied to charge the supply roller 53 and the developing roller 55 will be described with reference to FIGS. FIG. 24 is a perspective view showing a state in which an end cover is removed from the left end side of the developing cartridge, FIG. 25 is a perspective view showing a contact state between a conductive elastic plate, a supply roller and a developing roller, and FIG. It is a perspective view of a conductive elastic plate. In FIG. 25, the blade fixing frame 85, the blade support plate 89, and the regulating blade 91 are omitted.
[0084]
As described above, the supply roller 53 and the developing roller 55 can be charged to attract toner to the peripheral surface of the roller. Further, the regulating blade 91 is also chargeable because the toner conveyed to the developing area is appropriately charged. The voltage applied for the charging includes one electric terminal (not shown) connected to the right end of the developing roller 55, the rotating shaft 135 of the developing roller 55 and the left end of the developing roller 55 from the one electric terminal. The conductive elastic plate 193 is provided between the conductive elastic plate 193 and another electric terminal (not shown) connected to the right end of the supply roller 53 via the rotation shaft 139 of the supply roller 53. Can apply a voltage to the regulating blade 91 as well.
[0085]
As shown in FIG. 24, the conductive elastic plate 193 is provided inside the end cover 169 of the developing cartridge 12, and has a three-dimensional structure formed by bending a flat plate as a whole as shown in FIG. . The conductive elastic plate 193 has a first screw fixing portion 195 and a second screw fixing portion 197, and is fixed to a screw hole (not shown) formed on the left end surface of the housing 43 of the developing cartridge 12 by screws 199 and 201, respectively. Have been.
[0086]
From the first screw fixing part 195 and the second screw fixing part 197, a first arm part 203 and a second arm part 205 extending in directions substantially orthogonal to each other are formed, and the first arm part 203 and the second arm part 205 are formed. 205 crosses at a first electrical contact 207. The first electric contact 207 is in contact with the left end side of the rotation shaft 139 of the supply roller.
[0087]
By forming the first electrical contact 207 at the intersection of the first arm 203 and the second arm 205 extending in a direction substantially orthogonal to each other, the first arm 203 and the second arm 205 are connected to each other. Acting as a leaf spring, the first electric contact 207 can buffer the contact pressure at which the end of the rotation shaft 139 of the supply roller comes into contact. Therefore, in the first screw fixing portion 195 and the second screw fixing portion 197 separated from the first electric contact 207, even if the conductive elastic plate 193 is strongly tightened to the housing 43 by the screws 199 and 201, the first arm portion 203 The contact pressure of the first electrical contact 207 on the end of the rotation shaft 139 of the supply roller does not increase so much due to the leaf spring buffering action of the second arm 205.
[0088]
On the other hand, as a result of being screwed to the housing 43 by the first screw fixing portion 195 and the second screw fixing portion 197, the first electrical contact 207 is conductive so as to be urged to the end of the rotating shaft 139 of the supply roller. Since the elastic plate 193 is elastically deformed, it is possible to reliably maintain a state in which the first electrical contact 207 contacts the end of the rotating shaft 139 of the supply roller with an appropriate contact pressure.
[0089]
As described above, since the first electric contact 207 can surely come into contact with the end of the supply roller rotating shaft 139 with a relatively weak contact pressure, the first electric contact 207 due to the rotation of the supply roller rotating shaft 139 is in contact with the first electric contact 207. Hole of the first electrical contact 207 due to wear of the first electrical contact 207 can be prevented.
[0090]
In the above embodiment, the crossing angle between the first arm 203 and the second arm 205 is approximately 90 degrees, but the contact pressure at which the first electrical contact 207 contacts the end of the rotation shaft 139 of the supply roller is delicate. In order to change the angle, the crossing angle can be appropriately changed in the range of 30 to 150 degrees, preferably in the range of 60 to 120 degrees, and more preferably in the range of 80 to 100 degrees.
[0091]
The conductive elastic plate 193 further has a third arm portion 209 extending integrally from the second screw fixing portion 197, and a second spring-shaped second electric member is provided in the middle of the third arm portion 209 via a branch arm portion 211. The contact 213 is connected. The second electric contact 213 has a shape curved downwardly convex as shown in FIG. 26, and functions as an electric contact by pressing the curved lower surface against the left end of the rotating shaft 135 of the developing roller. In the present example, the first arm 203, the second arm 205, the third arm 209, the branch arm 211, the first electrical contact 207, and the second electrical contact 213 are located on the left end face side of the developing cartridge 12. They are located in substantially the same plane.
[0092]
From the end of the third arm portion 209 opposite to the second screw fixing portion 197, a fourth arm portion 215 is formed, which is bent substantially 90 degrees and extends toward the right end of the developing roller 55. A ring-shaped third screw fixing portion 217 is formed at the end of the fourth arm portion 215, and the third arm portion 215 is slightly pulled toward the right end of the developing cartridge 12 as indicated by an arrow 216. The screw fixing part 217 is fixed to the lower frame part 77 with a screw 219. Electrical conduction is formed from the lower frame portion 77 to the regulating blade 91 (see FIG. 6B) via the blade supporting plate 89, and as a result, a potential applied to the conductive elastic plate 193 causes the regulating blade 91 to charge the regulating blade 91. Bring. In the present embodiment, the potential applied to the regulating blade 91 is adjusted to be equal to the potential applied to the supply roller 53 and the developing roller 55, but is not necessarily required to be equal.
[0093]
When the fourth arm 215 is fixed in a state where it is slightly pulled in the direction indicated by the arrow 216, the third arm 209 is bent toward the arrow 216, and the second electrical contact 213 in the form of a leaf spring is thereby caused. As a result, it is possible to maintain a state in which it is bent and abuts against the left end of the rotating shaft 135 of the developing roller with an appropriate contact pressure. Since the second electric contact 213 is formed at a free end branched from the fourth arm portion 215, even if the pulling force in the direction of the arrow 216 is somewhat strong, the second electric contact 213 has a buffer effect due to the leaf spring action of the second electric contact 213. Does not occur, and a contact pressure that is so strong that a hole is formed in the second electrical contact 213 due to wear does not occur in the second electrical contact 213. Therefore, a stable electric contact can be provided for a long time.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an image forming apparatus to which the present invention is applied.
FIG. 2 is a perspective view of the rotary developing unit of the present invention.
FIG. 3 is a perspective view of the developing cartridge of the present invention with a housing member opened.
FIG. 4 is a side sectional view of the developing cartridge of the present invention.
FIG. 5 is an explanatory diagram showing the movement of toner during rotation according to the present invention.
6A is a front view showing the entirety of the roller supporting frame of the present invention, FIG. 6B is an enlarged view of the left side portion of the roller supporting frame, and FIG. 6C is a roller end seal member and the periphery of the roller supporting frame; FIG.
7A illustrates a state in which the shaft is supported by breaking the left side of the developing roller in FIG. 3; FIG. 7B illustrates a state in which the shaft is supported by breaking the right side of the developing roller 55 in FIG. 3; It is sectional drawing which shows a mode that it is.
FIG. 8 is a perspective view of a roller support frame, a supply roller, and a developing roller of the present invention.
FIG. 9 is a side view showing a drive system of a supply roller and a developing roller of the present invention.
FIG. 10 is a partial perspective view showing a drive system of a supply roller and a developing roller of the present invention.
FIG. 11 is a side sectional view of the vicinity of an idle gear according to the present invention.
FIG. 12 is a sectional view taken along a longitudinal axis of a rotation shaft of the idle gear according to the present invention;
FIG. 13 is a longitudinal sectional view showing the inside of the developing roller driving gear of the present invention.
FIG. 14 is a perspective view showing a developing cartridge of the present invention with its right side portion opened.
FIG. 15 is a perspective view showing a structure around a contact portion according to the present invention.
FIG. 16 is a perspective view of a developing roller provided with the low friction member of the present invention.
FIG. 17 is a front view showing the relationship between the contact regulating roller and the photosensitive drum according to the present invention.
FIG. 18 is a perspective view of the end cover according to the present invention as viewed from the back side.
FIG. 19 is an exploded perspective view showing a left side portion of the developing cartridge of the present invention.
FIG. 20 is an explanatory diagram when a developing roller of the present invention approaches a photosensitive drum.
FIG. 21 is an enlarged perspective view of the contact regulating roller of the present invention.
FIG. 22 is a longitudinal section of a contact regulating roller according to the present invention.
FIG. 23 is a cross-sectional view showing another embodiment of the contact regulating roller of the present invention.
FIG. 24 is a perspective view showing a left end side of the developing cartridge of the present invention.
FIG. 25 is a perspective view showing a contact state of the conductive elastic plate of the present invention.
FIG. 26 is a perspective view of the conductive elastic plate of the present invention.
[Explanation of symbols]
Reference Signs List 1 image forming device, 3 device main body, 5 photosensitive drum, 7 rotation direction
9 charger, 11 rotary developing unit, 12 developing cartridge
13 cleaning unit, 15 exposure unit, 17 primary transfer area
19 transfer unit, 21 intermediate transfer belt, 23 secondary transfer area
25 cassettes, 27 fixing unit, 29 discharge tray, 31 rotating shaft
33 frame element, 35 support frame, 37 storage section, 39 developing position
41 Upper housing member, 42 Lower housing member, 43 Housing
45 toner storage unit, 47 toner, 51 stirring piece, 53 supply roller
55 developing roller, 57 upper surface of upper housing member, 61 communication hole
63 seals, 65 areas, 69 contact control rollers, 75 roller support frames,
77 lower frame part, 79a, 79b side frame part, 81 screw, 83 upper frame part,
85 blade fixing frame, 87 fixing screw, 89 blade support plate
91 regulating blade, 93 backup sponge,
95a, 95b End face of lower housing member, 99 through hole for developing roller
101a, 101b shaft holding member, 105 shaft holding portion, 106 hole,
107 screws, 109 holes, 111 screws, 113 holes,
115 screw hole, 117 shatterproof seal member, 119 backup sponge
121 seal member, 123 roller end seal member, 125 low friction function member
127 powder seal function member, 128 pins, 129 rotary gear,
130 Right end face of housing, 131 Idle gear,
133 support shaft of idle gear, 135 rotation shaft of developing roller,
137 developing roller drive gear, 138 grease, 139 rotation axis of supply roller,
141 supply roller drive gear, 143 first gear part, 145 second gear part
147 arrow, 149 arrow, 151 pressure distribution plate, 153 holding part
155 Nut, 157 Outer part of developing roller drive gear
159 Inner part of developing roller drive gear, 161 support part, 163 degree contact part
165 Roller receiver, 167 Low friction member, 169 End cover, 171 Slot
172 screw holes, 173 press-fit projections, 174 screw holes, 175 holes
176 screw, 177 end press-fit part, 178 screw, 179 inner press-fit part
181 Roller body, 183 Roller working part, 185 Inner projection
187 inner peripheral surface (extended portion) other than the inner projection, 189 peripheral surface of
191 inner peripheral surface of the inner protrusion, 193 conductive elastic plate, 195 first screw fixing part,
197 second screw fixing part, 199 screw, 201 screw, 203 first arm part
205 second arm part, 207 first electric contact, 209 third arm part
211 branch arm part, 213 second electric contact, 215 fourth arm part
216 arrow, 217 third screw fixing part, 219 screw
L laser beam, S sheet member

Claims (6)

By rotating around a rotation axis with a plurality of developing cartridges mounted, the selected developing cartridge can be moved adjacent to the photosensitive drum in the image forming apparatus and the toner in the developing cartridge can be transferred to the photosensitive drum. In the developing cartridge used in the rotary developing unit, the developing cartridge is
A housing having a peripheral surface and two end surfaces on both sides of the peripheral surface;
A toner storage portion formed in the housing and configured to store toner;
A roller for supplying toner in the toner storage unit to the photosensitive drum,
A gear provided on a metal rotating shaft of the roller, outside the housing, for driving the roller to rotate.
The gear has a double structure including a resin outer portion having gear teeth formed on an outer periphery thereof, and a sintered metal inner portion located inside the outer portion. Wherein the rotation shaft of the roller is inserted and fixed in the developing cartridge. 2. A supply roller according to claim 1, wherein a roller for supplying the toner to the photosensitive drum is provided adjacent to the toner container, and a rotation shaft of which is rotatably supported on the two end surfaces. A heat radiating device for a developing cartridge, comprising: a developing roller having a peripheral surface that is in contact with a peripheral surface of the supply roller, and a rotation shaft of which is rotatably supported by the two end surfaces. 3. The heat radiating device according to claim 2, wherein the gear having the double structure is a developing roller driving gear for driving the developing roller. 4. The device according to claim 3, wherein a first gear portion and a second gear portion having different diameters are formed adjacent to each other on a peripheral surface of the developing roller driving gear in a rotation axis direction, and the inner portion is formed of the first gear portion. A heat radiating device in a developing cartridge, wherein the heat radiating device is formed so as to extend over a gear portion and a second gear portion. 5. The developing cartridge according to claim 1, wherein the gear having the double structure is formed by molding the outer member by insert molding in a state where the inner portion is present. 6. Heat dissipation device. A developing cartridge comprising the heat radiating device according to claim 1.

Images