JP3543712B2 - Developing device and image forming apparatus including developing device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention supplies toner to an electrostatic latent image formed on the surface of a photoconductor drum to perform toner development of the electrostatic latent image, and transfers an image developed on the surface of the photoconductor drum to toner. Particularly, the present invention relates to a developing device used in an image forming apparatus such as a laser printer that forms an image by performing toner image formation. In particular, toner leakage occurs between a toner supply roller disposed in the developing device and a seal member that contacts both ends of the toner supply roller. The present invention relates to a developing device in an image forming apparatus capable of preventing friction torque from decreasing and increasing the rotational torque of a toner supply roller while effectively preventing the development, and an image forming apparatus including the developing device.
[0002]
[Prior art]
2. Description of the Related Art Various types of developing devices used in image forming apparatuses such as laser printers have been proposed. An example of such a developing device will be described with reference to FIGS. FIG. 9 is an explanatory view schematically showing a main part of a conventional developing device, and FIG. 10 is a perspective view showing a main part of the conventional developing device.
[0003]
In FIG. 9, the developing device has a toner cartridge 100 for storing toner, and a toner supply port 101 (a hole formed substantially at the center of the toner cartridge 100 and a frame F) is provided in the toner cartridge 100 by stirring the toner. And an agitator 103 for supplying the toner to the developing chamber 102 side through a hole formed in the developing chamber 102. A toner supply roller 104 is rotatably disposed at a lower position in the developing chamber 102 closed by the upper frame F1 and the lower frame F2, and the toner supply roller 104 is configured to supply the toner supplied from the toner supply port 101. It is supplied to the developing roller 105. A blade 107 is fixed to the inner wall of the upper frame F1 above the developing roller 105 via a fixing member 106. The blade 107 reduces the thickness of the toner layer supplied to the surface of the developing roller 105. Acts to regulate. Further, the developing roller 105 is disposed so as to be in contact with the photosensitive drum 108, and an electrostatic latent image is formed on the surface of the photosensitive drum 108 by an exposure device (not shown) that scans a laser beam based on image data. Is formed. The developing roller 105 supplies toner to the electrostatic latent image formed on the surface of the photoconductor drum 108 to perform toner development of the image. Further, the image developed on the surface of the photoconductor drum 108 is supplied with toner. The image is transferred onto a sheet fed from a paper unit (not shown) to form an image.
[0004]
In FIG. 10, on both sides of the developing chamber 102, side seal members 109 made of a sponge material that are in contact with both ends of the toner supply roller 104 and seal the toner on both sides inside the developing chamber 102 are arranged. ing. A roller shaft 104A of the toner supply roller 104 is inserted into a shaft hole 109A of each side seal member 109 (see FIG. 11 and the like). Thus, both ends of the roller material 104B (covering the roller shaft 104A and formed of sponge) of the toner supply roller 104 are in contact with the inner surface of the side seal member 109, and the toner supply roller 104 is in this contact state. The toner is supplied to the developing roller 105 by rotation.
[0005]
A support plate 110 that rotatably supports the toner supply roller 104 is disposed outside each side seal member 109. The upper side of the developing chamber 102 is sealed by an upper seal member (not shown), and the lower side is sealed by a lower frame F2.
[0006]
[Problems to be solved by the invention]
In the conventional developing device, in order to effectively prevent leakage of toner between a toner supply roller disposed in the development device and a seal member contacting both ends thereof, the toner supply roller 104 has a roller shaft. 104A is inserted into the shaft hole 109A of each side seal member 109, and both ends are rotated while contacting each side seal member 109 during toner supply. It is necessary that the frictional resistance generated between the toner supply roller 104 and the side seal member 109 does not become excessive while the and the side seal member 109 are surely in contact with each other.
[0007]
For example, as shown in FIG. 11, when a gap A exists between the end of the toner supply roller 104 and the side seal member 109, the toner supplied from the toner cartridge 100 via the toner supply port 102 However, the toner leaks from the gap A. As a result, the leaked toner is inadvertently adhered to the edge of the sheet from the developing roller 105 via the photosensitive drum 108, and the vertical streak is formed on the sheet. There is a problem that printing failure occurs.
[0008]
On the other hand, as shown in FIG. 12, when the end of the roller member 104B of the toner supply roller 102 is excessively pressed against the side seal member 109, the toner is generated between the end of the roller member 104B and the side seal member 109. Therefore, there is a problem that the rotational driving of the toner supply roller 102 is hindered due to an increase in the torque of the toner supply roller 102 as a result.
[0009]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is intended to reduce the frictional resistance and increase the rotational torque of the toner supply roller while performing good toner sealing on both sides of the developing chamber. An object of the present invention is to provide a developing device in an image forming apparatus capable of preventing the image forming apparatus and an image forming apparatus having the developing device.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the developing device according to claim 1,Developing roomA supply roller, which is rotatably disposed within the roller shaft and has a roller shaft covered with a roller material, and a toner carried on an outer peripheral surface of the supply roller via the supply roller; A developing roller that develops the latent image with the toner, a seal member having a shaft hole that is in contact with both ends of a roller shaft body and a roller material of the supply roller, and has a shaft hole into which the roller shaft is inserted; Is placed at a position where the seal member is in contact with the roller shaft and both ends of the roller material.TwoWith washer memberThe two washer members are formed by punching a film sheet, and burrs generated on a side opposite to a punching direction are arranged so as to abut against the seal member and the roller member, respectively.
[0011]
In the developing device according to the first aspect, the washer member into which the roller shaft of the supply roller is inserted is disposed at a position where the seal member and the roller shaft body and both end portions of the roller material are in contact with each other. With almost no contact between both ends of the shaft member and the roller member, while preventing the leakage of toner by contacting the peripheral end portion of the roller member and the seal member, the seal member and the roller shaft member during rotation of the supply roller, It is possible to reduce the frictional resistance generated between the roller member and the roller member.In addition, the surfaces of the two washer members on which the burr does not exist are in contact with each other, so that the superior sliding characteristics of each washer can be used to rotate the supply roller between the end of the supply roller and the inner surface of the seal member. The frictional resistance generated by the above can be remarkably reduced.
[0012]
Claims1The developing device according to,The washer member is formed from a film sheet. When the washer member is formed from a film sheet as described above, the shaft of the supply roller and both ends of the roller material are mainly brought into contact with the washer member having a good sliding characteristic. It is possible to further reduce the frictional resistance generated between the seal member, the roller shaft, and the roller material during the rotation of the roller, and to smoothly rotate the supply roller.
[0013]
Further, the claims2The developing device according to claim1Wherein the outer diameter of the washer member is set to be larger than the shaft diameter of the roller shaft body and smaller than the roller diameter of the supply roller.3The developing device according to claim 1,OrClaim2Wherein the roller member and the seal member are formed of a sponge material.
[0014]
Claim2And claims3In the developing device of (1), the outer diameter of the washer member is set to be larger than the shaft diameter of the roller shaft body, so that the roller shaft body is supplied in contact with the washer member without directly contacting the seal member made of a sponge material. It is possible to reduce frictional resistance when the roller rotates. Further, since the outer diameter of the washer member is set smaller than the roller diameter of the supply roller, the roller member made of a sponge material is slightly deformed by the washer member, and comes into contact with the seal member at the peripheral end thereof so that the toner is removed. Leakage can be reliably prevented.
[0015]
Claims4The developing device according to the present invention includes a supply roller formed by coating a roller material around a roller shaft having a roller shaft, and a developing roller that develops an electrostatic latent image on the photosensitive drum with toner supplied from the supply roller. Members provided on both sides of a roller shaft body and a roller material in the supply rollerAnd two washer members which are disposed at positions where the roller shaft is inserted and at which the seal member and both ends of the roller shaft body and the roller material are in contact with each other.By extending both end surfaces of the roller material outside the both end surfaces of the roller shaft, the both end surfaces of the roller material and the seal member are brought into contact with each other.The two washer members are formed by punching a film sheet, and burrs generated on a side opposite to a punching direction are arranged so as to abut against the seal member and the roller member, respectively.
[0016]
Claim4In the developing device, since both end surfaces of the roller material in the supply roller extend outside the both end surfaces of the roller shaft, both end surfaces of the roller shaft areWasher member andWithout direct contact with the seal member, both end surfaces of the roller material and the seal member are brought into contact, thereby reducing the contact area between the both end portions of the supply roller and the seal member, thereby reducing frictional resistance. It becomes possible. Further, since the end surface of the roller member is always in contact with the inner surface of the seal member, it is possible to reliably prevent the toner from inadvertently leaking from the supply roller to the developing roller.In addition, the surfaces of the two washer members on which the burr does not exist are in contact with each other, so that the superior sliding characteristics of each washer can be used to rotate the supply roller between the end of the supply roller and the inner surface of the seal member. The frictional resistance generated by the above can be remarkably reduced.
[0017]
[0018]
[0019]
And claims5The image forming apparatus according toDeveloping roomA supply roller, which is rotatably disposed within the roller shaft and has a roller shaft covered with a roller material, and a toner carried on an outer peripheral surface of the supply roller via the supply roller; In an image forming apparatus including a developing device having a developing roller for developing a latent image with the toner, a shaft that is in contact with both ends of a roller shaft body and a roller material of the supply roller, and in which the roller shaft is inserted. A seal member having a hole, the roller shaft is inserted and fitted, and the seal member is disposed at a position where the roller shaft body and both ends of the roller material are in contact with each other.Two HornWith washer memberThe two washer members are formed by punching a film sheet, and burrs generated on a side opposite to a punching direction are arranged so as to abut against the seal member and the roller member, respectively.It is characterized by the following.
According to a sixth aspect of the present invention, there is provided an image forming apparatus, comprising: a supply roller formed by covering a roller shaft around a roller shaft having a roller shaft; and an electrostatic latent image on the photosensitive drum by toner supplied from the supply roller. An image forming apparatus provided with a developing device having a developing roller for developing, wherein a seal member disposed on both sides of a roller shaft and a roller material in the supply roller; A shaft member inserted therein and two washer members disposed at positions where the seal member and the roller shaft body and both ends of the roller material are in contact with each other; and both end surfaces of the roller material are both end surfaces of the roller shaft body. By extending more outwardly, both end faces of the roller material and the seal member are brought into contact, and the two washer members are formed by punching a film sheet, and the burr generated on the side opposite to the punching direction is formed. The seal member and the roller member are arranged so as to be in contact with each other.
[0020]
Claim5In the image forming apparatus, the washer member in which the roller shaft of the supply roller is inserted in the developing device is disposed at a position where the seal member and both ends of the roller shaft body and the roller material are in contact with each other. The seal member and the roller are rotated during the rotation of the supply roller while preventing the toner from leaking by making the peripheral end of the roller material and the seal member contact with each other without making the member and the roller shaft and both ends of the roller material almost contact each other. It is possible to reduce the frictional resistance generated between the shaft body and the roller material.
[0021]
In particular, if the outer diameter of the washer member is set to be larger than the shaft diameter of the roller shaft member, the roller shaft member is brought into contact with the washer member without directly contacting the seal member, thereby further reducing frictional resistance when the supply roller rotates. It is possible to do.
[0022]
As a result, the frictional resistance is reduced and the rotational torque of the toner supply roller is increased while effectively preventing the leakage of the toner between the toner supply roller disposed in the developing device and the seal contacting both ends of the toner supply roller. It is possible to realize an image forming apparatus capable of preventing such a situation.
Further, in the image forming apparatus according to the sixth aspect, since both end surfaces of the roller material in the supply roller extend outside the both end surfaces of the roller shaft, both end surfaces of the roller shaft are connected to the washer member and the seal member. Without direct contact, the both end surfaces of the roller material and the seal member are brought into contact, whereby it is possible to reduce the contact area between the both end portions of the supply roller and the seal member, thereby reducing frictional resistance. . Further, since the end surface of the roller member is always in contact with the inner surface of the seal member, it is possible to reliably prevent the toner from inadvertently leaking from the supply roller to the developing roller.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a developing device according to the present invention will be described in detail with reference to the drawings based on an embodiment in which the present invention is embodied as a developing device of a laser printer. First, a schematic configuration of a laser printer according to the present embodiment will be described with reference to FIGS. FIG. 1 is an exploded perspective view of main components of the laser printer, and FIG. 2 is a side sectional view of the laser printer.
[0024]
In FIG. 1, a main body case 1 of a laser printer P is formed by integrally molding a main frame 1a and a main cover 1b by injection molding or the like. A scanner unit 2, a process unit 3, a fixing unit 4, and a paper feed unit 5 are mounted on the main frame 1a from above. Further, the main cover 1b covers the outer surfaces of the main frame 1a in four rounds (front and rear and right and left sides). Further, a drive system unit 6 including a drive motor and a gear train is inserted from below the main body case 1 and fixed in a storage recess 33 formed by an outer surface of the main frame 1a and an inner surface of the main cover 1b. You.
[0025]
Further, the top surfaces of the main frame 1a and the main cover 1b are covered with a top cover 7, and the top cover 7 has holes 7a for penetrating an operation panel portion 1c formed to project upward from the main frame 1a. Further, an opening 7b for penetrating the base of the sheet feeding unit 5 is formed. Further, a pair of brackets 9 having support shafts 9a protruding inward on both sides thereof are provided on the front side (the right side in FIG. 1) of the top cover 7 (in FIG. 1, Only one of them is shown), and a support shaft 9 a of each bracket 9 supports a support hole 8 b of each support portion 8 a formed on both sides of the paper discharge tray 8. Thereby, the paper discharge tray 8 is supported rotatably with respect to the top cover 7. In addition, a step 7e is formed on the upper surface of the top cover 7 between the upper surface of both side portions 7c and the upper surface of the central portion 7d, and the step 7e discharges paper when the discharge tray 8 is not used. A storage recess 7f (see FIG. 2) for storing the tray 8 on the central portion 7d of the top cover 7 is configured. Thus, the paper discharge tray 8 is stored in the storage recess 7f by rotating to the storage position on the top cover 7 side when not in use, and is rotated from the storage position in the direction opposite to the storage direction during use. Thus, the sheet discharged from the fixing unit 4 is set at a stack position (see FIG. 2) where the sheets are sequentially stacked.
[0026]
Next, a schematic configuration inside the laser printer P will be described with reference to FIG. In FIG. 2, sheets 50 are stored in a stacked state in a feeder case 5a of a sheet feeding unit 5, and a leading end of each sheet 50 is provided with a biasing spring 10a provided in the feeder case 5a. While being pressed toward the paper feed roller 11 via the plate 10, the paper is separated one by one by the paper feed roller 11 and the paper separating member 62 that rotate while being transmitted with power from the drive system unit 6. The separated sheet 50 is fed to the process unit 3 by a pair of upper and lower registration rollers 13 and 14.
[0027]
Here, the process unit 3 supplies toner to an electrostatic latent image formed on the surface of the photosensitive drum 12 in accordance with image data via a laser optical system, which will be described later, provided in the scanner unit 2. A unit for performing toner development of an image. More specifically, the process unit 3 includes a photosensitive drum 12 and a transfer roller 17 that contacts the upper surface thereof, a scorotron-type charger 18 disposed below the photosensitive drum 12, a photosensitive drum 12 in the sheet feeding direction. A developing device having a developing roller 19 and a toner supply roller 20 disposed upstream of the photosensitive drum 12; and a detachable toner cartridge 21 serving as a toner storage unit disposed upstream of the developing device. The cleaning roller 22 and the like are disposed at the same position.
[0028]
A pair of lower auger rollers 34 and an upper auger roller 35 are rotatably disposed above the toner supply roller 20 in the developing chamber of the developing device. The lower auger roller 34 is supplied from the toner cartridge 21 to the developing chamber via a toner supply port 21A (consisting of a hole formed at a substantially central position of the toner cartridge 21 and a hole formed on the unit frame 25 side). The upper auger roller 35 conveys the toner from both ends of the toner supply roller toward the toner supply port 21A above the toner supply roller 20. Perform the action of As described above, the toner supplied from the toner supply port 21A to the developing chamber via the lower auger roller 34 and the upper auger roller 35 is circulated and conveyed above the toner supply roller 20 in both side directions. Is supplied to the toner supply roller 20 while being circulated and conveyed. The blade 24 is fixed to the lower surface of the unit frame 25 above the developing roller 19 by an L-shaped blade fixing member 36. The blade 24 regulates the thickness of the toner layer supplied from the toner supply roller 20 onto the developing roller 19 to a predetermined thickness.
[0029]
Further, an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 12 by scanning (scanning) a laser beam from the scanner unit 2 on the charged layer formed by the charger 18. The toner in the toner cartridge 21 is agitated by the agitator 23 and released from the toner supply port 21 </ b> A, and then carried on the outer peripheral surface of the developing roller 19 via the toner supply roller 20. Is regulated. The electrostatic latent image formed on the photoconductor drum 12 is visualized by toner attached from the developing roller 19, and is transferred to a sheet 50 passing between the transfer roller 17 and the photoconductor drum 12. Then, the toner remaining on the photosensitive drum 12 is temporarily held by the cleaning roller 22, returned to the photosensitive drum 12 at a predetermined timing, and collected by the developing roller 19 into the developing chamber.
[0030]
The process unit 3 configured as described above is made into a cartridge by being incorporated in a unit frame 25 made of a synthetic resin, and the cartridge-formed process unit 3 is detachably mounted to the main frame 1a. .
[0031]
The scanner unit 2 includes a known laser optical system, and scans the laser optical system based on predetermined image data to form an electrostatic latent image on the surface of the photosensitive drum 12. More specifically, the scanner unit 2 is disposed below the process unit 3, and a scanner cover 26 is attached to the upper surface of the scanner unit 2. The scanner cover 26 is fixed to the main frame 1a on the upstream side of the bottom plate 27 so as to cover most of the opening. The scanner unit 2 as an exposure unit includes a laser light emitting unit (not shown), a scanner motor 28, a polygon mirror 29, a lens 30, a reflecting mirror 31, and the like arranged on a lower surface side of a scanner cover 26. Passes through a glass plate 33 inserted in a horizontally long scanner hole 32 formed in the scanner cover 26 so as to extend along the axis of the photoconductor drum 12, and to the outer peripheral surface of the photoconductor drum 12 in the process unit 3. Irradiated. Thus, an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 12 by exposure in accordance with the image data. As described above, the toner is supplied to the electrostatic latent image formed on the photosensitive drum 12 by the laser optical system of the scanner unit 2 through the process unit 3, and the toner development of the electrostatic latent image is performed. Is
[0032]
The toner image based on the electrostatic latent image formed on the photosensitive drum 12 in the process unit 3 is transferred to the sheet 50 fed to the process unit 3 as described above. Paid. In the fixing unit 4, the toner image transferred onto the sheet 50 via the pair of heating rollers 15 and the pressing roller 16 is thermally fixed. Thereafter, the paper 50 on which the image is formed is discharged while being sequentially stacked on the discharge tray 8 at the stack position by the rollers 15 and 16. Here, in FIG. 2, the trajectory R of the sheet 50 fed from the sheet supply unit 5 to the sheet discharge tray 8 is indicated by a two-dot chain line.
[0033]
Next, a detailed configuration of the developing chamber in the process unit 3 will be described with reference to FIGS. FIG. 3 is a side sectional view of the process unit 3, and FIG. 4 is a front sectional view showing the inside of the developing chamber. The developing chamber D includes an upper seal member 37 disposed on the lower surface of the upper frame 25A of the unit frame 25, a lower frame 25B of the unit frame 25, and a pair of side walls formed on both sides of the developing chamber D and formed of a sponge material. It is constituted by a space surrounded by a seal member 38 (see FIG. 4). The toner supply roller 20 is configured by coating a roller member 20C made of a sponge material around a roller shaft member 20B having a roller shaft 20A formed at both ends thereof, and each roller shaft 20A is formed by a side seal member. 38 is supported by a pair of support plates 39 rotatably attached to the lower frame 25B on the outside thereof (see FIG. 4). . Further, both ends of the roller shaft 20B and both ends of the roller material 20C are in contact with the inner surfaces of the side seal members 38 via washers 40 described later. Such a contact state will be described later.
[0034]
The center of rotation of each support plate 39 is indicated by C in FIG. Each of the support plates 39 rotatably supports the developing roller 19, and is urged in a clockwise direction in FIG. 3 via an urging spring (not shown) so that each of the support plates 39 rotates. The developing roller 19 is rotated clockwise about the center C, and the developing roller 19 contacts the photosensitive drum 12. As described above, since the toner supply roller 20, the lower and upper auger rollers 34 and 35, and the developing roller 19 are integrally supported on each support plate 39, the toner supply roller 20, each of the lower and upper auger rollers 34, Adjustment of the positional relationship between the developing roller 35 and the developing roller 19 can be easily performed as a unit, and maintenance and the like can be easily performed.
[0035]
As shown in FIG. 4, the lower auger roller 34 has spiral teeth 34 </ b> A spirally formed from the center position toward both ends, and the roller shaft 34 </ b> B supports each supporting member similarly to the toner supply roller 20. It is supported by a plate 39. When the lower auger roller 34 is rotated clockwise in FIG. 3, the toner supplied from the toner supply port 21 </ b> A sequentially flows in the developing chamber D above the toner supply roller 20 according to the spiral direction of the spiral teeth 34 </ b> A. It is transported in both directions. The upper auger roller 35 has spiral teeth 35A spirally formed from both ends toward the center position, and the roller shaft 35B is supported by each support plate 39 as described above. As a result, when the upper auger roller 35 is rotated clockwise in FIG.ToThe transported toner is sequentially transported toward the toner supply port 21A according to the spiral direction of the spiral teeth 35A. As described above, the lower auger roller 34 and the upper auger roller 35 perform an operation of circulating and conveying the toner supplied from the toner supply port 21A into the developing chamber D above the toner supply roller 20, and thereby the toner is supplied. The toner can be uniformly supplied to the toner supply roller 20 without local stagnation.
[0036]
Next, the manner of contact between both ends of the roller shaft 20B of the toner supply roller 20 and both ends of the roller material 20C and the inner surfaces of the side seal members 38 will be described with reference to FIG. FIG. 5 is an explanatory view schematically showing a contact state between the toner supply roller 20 and the side seal member 38. Although FIG. 5 shows only the contact state at one end of the toner supply roller 20, a similar contact state exists at the other end.
[0037]
5, a washer 40 formed by punching a PET (polyethylene terephthalate) film sheet is interposed between the end of the toner supply roller 20 and the side seal member 38. Here, the outer diameter D1 of the washer 40 is set larger than the shaft diameter D2 of the roller shaft body 20B and smaller than the roller diameter D3 of the toner supply roller 20. Thus, since the outer diameter D1 of the washer 40 is set to be larger than the shaft diameter D2 of the roller shaft 20B, the end surface of the roller shaft 20B does not directly contact the inner surface of the side seal member 38, It comes into contact with the washer 40 having excellent sliding characteristics, and most of the end face of the roller material 20C also comes into contact with the washer 40. Thus, the frictional resistance generated between the end of the toner supply roller 20 and the inner surface of the side seal member 38 when the toner supply roller 20 rotates can be reduced. As a result, the rotation torque of the toner supply roller 20 does not increase. Further, since the outer diameter D1 of the washer 40 is set smaller than the roller diameter D3 of the toner supply roller 20, the roller material 20C made of a sponge material has a portion corresponding to the washer 40 as shown in FIG. While being compressed slightly inward, the peripheral edge 20D keeps the state in contact with the inner surface of the side seal member 38, so that a gap is generated between the end of the toner supply roller 20 and the inner surface of the side seal member 38. Thus, the toner can be reliably sealed on both sides of the developing chamber without inadvertent leakage of the toner from the toner supply roller 20 to the developing roller 19.
[0038]
Next, another contact mode in which both end portions of the toner supply roller 20 and the inner surface of each side seal member 38 are brought into contact without using the washer 40 will be described with reference to FIG. FIG. 6 is an explanatory diagram schematically showing another contact state between the toner supply roller 20 and the side seal member 38. Although FIG. 6 shows only a contact state at one end of the toner supply roller 20, a similar contact state exists at the other end.
[0039]
In FIG. 6, the end of the roller material 20C in the toner supply roller 20 extends outside the end of the roller shaft 20B, and is located between the end surface of the roller shaft 20B and the inner surface of the side seal member 38. Is formed with a gap E. As a result, only the end surface of the roller material 20C comes into contact with the inner surface of the side seal member 38, and the contact area between the end of the toner supply roller 20 and the side seal member 38 is reduced, so that the friction at the time of rotation of the toner supply roller 20 is reduced. Resistance can be reduced. As a result, the rotation torque of the toner supply roller 20 does not increase. In addition, since the end surface of the roller member 20C is always in contact with the inner surface of the side seal member 38, it is possible to reliably prevent the toner from accidentally leaking. At this time, the frictional resistance generated between the end surface of the roller material 20C and the inner surface of the side seal member 38 is larger than that in the case of FIG. 5, but the rotation of the toner supply roller 20 and the prevention of toner leakage There is no problem above.
[0040]
Further, when the both end portions of the toner supply roller 20 and the inner surfaces of the side seal members 38 are brought into contact with each other, the configuration shown in FIG. . FIG. 7 is an explanatory view schematically showing still another contact state between the toner supply roller 20 and the side seal member 38. Although FIG. 7 shows only a contact state at one end of the toner supply roller 20, a similar contact state exists at the other end.
[0041]
In FIG. 7, between the end of the toner supply roller 20 and the side seal member 38, the same washer 40 as in FIG. At this time, the outer diameter D1 of the washer 40 is set larger than the shaft diameter D2 of the roller shaft body 20B and smaller than the roller diameter D3 of the toner supply roller 20. The same is true. 6, the end of the roller material 20C of the toner supply roller 20 extends outside the end of the roller shaft 20B, and the end of the roller shaft 20B and the washer 40. A gap E is formed between the side surface.
[0042]
Thus, the outer diameter D1 of the washer 40 is set to be larger than the shaft diameter D2 of the roller shaft 20B, and the gap E is formed between the end surface of the roller shaft 20B and the inner surface of the washer 40. Therefore, the end surface of the roller shaft 20B does not contact the washer 40, and only a part of the end surface of the roller material 20C contacts the washer 40. Therefore, when the toner supply roller 20 rotates, the frictional resistance generated between the end of the toner supply roller 20 and the inner surface of the side seal member 38 can be further reduced as compared with the case of FIG. Thereby, the rotation torque of the toner supply roller 20 can be further reduced.
[0043]
Also, as in the case of FIG. 5, the outer diameter D1 of the washer 40 is set smaller than the roller diameter D3 of the toner supply roller 20, so that the roller material 20C made of a sponge material corresponds to the portion corresponding to the washer 40. 7 is slightly compressed inward as shown in FIG. 7, while the peripheral portion 20D keeps the state of being in contact with the inner surface of the side seal member 38, so that the end of the toner supply roller 20 and the inner surface of the side seal member 38 are Inadvertent leakage of toner can be reliably prevented without generating a gap between them.
[0044]
The washer 40 is formed by punching a PET film as described above, and burrs are generally generated on the side opposite to the punching direction at the time of punching, but as shown in FIG. When the two washers 40 are interposed, the burrs are disposed on the inner surface side of the side seal member 38 and on the end surface side of the roller member 20C, respectively. This is because the side seal member 38 and the roller member 20C are formed of a sponge material, so that one washer 40 abuts the burr side on the inner surface of the side seal member 38 and uses the burr to form the side seal member 38. When the toner supply roller 20 rotates, the other washers 40 are fixed to the end surface of the roller material 20C by contacting the burr side of the other washer with the end surface of the roller material 20C and using burrs. Of the toner supply roller 20 is rotated only when the toner supply roller 20 rotates by utilizing the excellent sliding characteristic of each washer 40. This is based on the fact that the frictional resistance generated between the end and the inner surface of the side seal member 38 can be significantly reduced.
[0045]
Further, when the both end portions of the toner supply roller 20 and the inner surfaces of the side seal members 38 are brought into contact, a configuration as shown in FIG. 8 may be employed. FIG. 8 is an explanatory view schematically showing still another contact state between the toner supply roller 20 and the side seal member 38. Although FIG. 8 shows only a contact state at one end of the toner supply roller 20, a similar contact state exists at the other end. The configuration shown in FIG. 8 is basically the same as the configuration shown in FIG. 5, in which the roller shaft 20A is not formed at the end of the roller shaft 20B, and the end 20E of the roller shaft 20B is left as it is. The configuration is different from that of FIG. 5 in that it is inserted into the shaft hole 38A of the side seal member 38, and the remaining configuration is the same.
[0046]
In FIG. 8, a washer 40 is interposed between the end of the toner supply roller 20 and the side seal member 38. Here, the outer diameter D1 of the washer 40 is set larger than the shaft diameter D2 of the roller shaft body 20B and smaller than the roller diameter D3 of the toner supply roller 20. As described above, the outer diameter D1 of the washer 40 is set to be larger than the shaft diameter D2 of the roller shaft body 20B, and most of the end surface of the roller material 20C comes into contact with the washer 40. Thus, the frictional resistance generated between the end of the toner supply roller 20 and the inner surface of the side seal member 38 when the toner supply roller 20 rotates can be reduced, and therefore, the rotational torque of the toner supply roller 20 increases. Will not be invited. Further, since the outer diameter D1 of the washer 40 is set smaller than the roller diameter D3 of the toner supply roller 20, the roller material 20C made of a sponge material has a portion corresponding to the washer 40 as shown in FIG. While being compressed slightly inward, the peripheral edge portion 20D keeps the state in contact with the inner surface of the side seal member 38, so that a gap is generated between the end of the toner supply roller 20 and the inner surface of the side seal member 38. Inadvertent leakage of toner can be reliably prevented.
[0047]
As described above in detail, in the developing device according to the present embodiment, when the configuration illustrated in FIG. 5 is employed, the washer 40 into which the roller shaft 20A of the toner supply roller 20 is inserted is formed by the side seal member 38 and the roller. Since the shaft member 20B and the roller material 20C are disposed at locations where they contact each other, the side seal member 38 and the roller shaft 20B and the roller material 20C hardly contact both ends of the roller material 20C. The friction between the side seal member 38 and the roller shaft 20B and the roller material 20C during rotation of the toner supply roller 20 is reduced while preventing the toner from leaking by bringing the peripheral end portion into contact with the side seal member 38. Can be reduced.
[0048]
Further, since the washer 40 is formed from a PET film sheet, both end surfaces of the roller shaft 20B and the roller material 20C of the toner supply roller 20 are mainly brought into contact with the washer 40 having a good sliding property. The frictional resistance generated between the side seal member 38, the roller shaft 20B, and the roller material 20C when the toner supply roller 20 rotates can be further reduced, and the toner supply roller 20 can be smoothly rotated.
[0049]
Further, since the outer diameter D1 of the washer 40 is set to be larger than the shaft diameter D2 of the roller shaft 20B, the roller shaft 20B contacts the washer 40 without directly contacting the side seal member 38 made of a sponge material. Thus, the frictional resistance during rotation of the toner supply roller 20 can be reduced. Further, since the outer diameter D1 of the washer 40 is set to be smaller than the roller diameter D3 of the toner supply roller 20, the roller material 20C made of a sponge material is slightly deformed by the washer 40 and has a side seal member at its peripheral end. 38 can be reliably prevented from leaking out of the toner.
[0050]
When the configuration shown in FIG. 6 is adopted in the developing device, both end surfaces of the roller material 20C of the toner supply roller 20 extend outside the both end surfaces of the roller shaft body 20B, and the end surface of the roller shaft body 20B is formed. A gap E is formed between the roller member 20C and the inner surface of the side seal member 38, so that only the end surface of the roller member 20C contacts the inner surface of the side seal member 38, and the end portion of the toner supply roller 20 and the side seal member The frictional resistance during rotation of the toner supply roller 20 can be reduced by reducing the contact area with the toner supply roller 38. Since the end surface of the roller member 20C is always in contact with the inner surface of the side seal member 38, it is possible to reliably prevent the toner from being accidentally leaked.
[0051]
Further, when the configuration shown in FIG. 7 is adopted in the developing device, the outer diameter D1 of the washer 40 is set to be larger than the shaft diameter D2 of the roller shaft 20B, and the end face of the roller shaft 20B is Since the gap E is formed between the roller member 20 and the inner surface of the roller member 40, the end surface of the roller shaft 20B does not contact the washer 40, and only a part of the end surface of the roller material 20C contacts the washer 40. Therefore, when the toner supply roller 20 rotates, the frictional resistance generated between the end of the toner supply roller 20 and the inner surface of the side seal member 38 can be further reduced. Further, since the outer diameter D1 of the washer 40 is set smaller than the roller diameter D3 of the toner supply roller 20, the roller material 20C made of a sponge material has a portion corresponding to the washer 40 as shown in FIG. While being compressed slightly inward, the peripheral edge portion 20D keeps the state in contact with the inner surface of the side seal member 38, so that a gap is generated between the end of the toner supply roller 20 and the inner surface of the side seal member 38. Inadvertent leakage of toner can be reliably prevented.
[0052]
When the configuration shown in FIG. 8 is adopted in the developing device, the washer 40 into which the end portion 20E of the roller shaft 20B of the toner supply roller 20 is inserted is formed by the side seal member 38 and the roller shaft 20B. Since the roller member 20C is disposed at a position where both ends of the roller member 20C are in contact with each other, the side seal member 38 and both ends of the roller member 20C are hardly brought into contact with each other as in the case of the configuration in FIG. It is possible to reduce the frictional resistance generated between the side seal member 38 and the roller member 20C when the toner supply roller 20 rotates, while preventing the toner from leaking by bringing the peripheral end portion into contact with the side seal member 38. .
[0053]
Further, since the washer 40 is formed from a PET film sheet, both end surfaces of the roller material 20C of the toner supply roller 20 are mainly brought into contact with the washer 40 having good sliding characteristics. The frictional resistance generated between the side seal member 38 and the roller material 20C during rotation can be further reduced, and the toner supply roller 20 can be rotated smoothly.
[0054]
Further, since the outer diameter D1 of the washer 40 is set smaller than the roller diameter D3 of the toner supply roller 20, the roller material 20C made of a sponge material is slightly deformed by the washer 40, and a side seal member is formed at a peripheral end thereof. 38 can be reliably prevented from leaking out of the toner. It should be noted that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention.
[0055]
【The invention's effect】
As described above, in the developing device according to the first aspect, since the roller shaft of the toner supply roller is inserted and the washer member is disposed at a position where the seal member and the roller shaft body and both ends of the roller material are in contact with each other. The seal member is brought into contact with the peripheral end portion of the roller member and the seal member to prevent the leakage of toner while making the seal member hardly contact the both ends of the roller shaft member and the roller member. Frictional resistance generated between the roller shaft member and the roller material can be reduced.In addition, the surfaces of the two washer members on which the burr does not exist are in contact with each other, so that the superior sliding characteristics of each washer can be used to rotate the supply roller between the end of the supply roller and the inner surface of the seal member. The frictional resistance generated by the above can be remarkably reduced.
[0056]
Claims1In the developing device according to the related art, the washer member is formed from a film sheet, and the shaft of the toner supply roller and both end portions of the roller material are mainly brought into contact with the washer member having a good sliding characteristic. The frictional resistance generated between the seal member, the roller shaft, and the roller material when the supply roller rotates is further reduced, so that the toner supply roller can be rotated smoothly.
[0057]
Further, the claims2And claims3In the developing device according to the present invention, since the outer diameter of the washer member is set to be larger than the shaft diameter of the roller shaft member, the roller shaft member is brought into contact with the washer member without directly contacting the seal member made of a sponge material. The frictional resistance during rotation of the toner supply roller can be reduced, and the outer diameter of the washer member is set to be smaller than the roller diameter of the toner supply roller. The toner is slightly deformed and comes into contact with the seal member at the peripheral end, so that leakage of the toner can be reliably prevented.
[0058]
Claims4In the developing device of (1), since both end surfaces of the roller material in the toner supply roller extend outside both end surfaces of the roller shaft, both end surfaces of the roller shaft areWasher member andThe end surfaces of the roller material and the seal member are brought into contact without directly contacting the seal member, thereby reducing the contact area between the end portions of the toner supply roller and the seal member to reduce frictional resistance. Can be. Further, since the end surface of the roller material is always in contact with the inner surface of the seal member, it is possible to reliably prevent the toner from inadvertently leaking from the toner supply roller to the developing roller.In addition, the surfaces of the two washer members on which the burrs do not exist are in contact with each other, so that the superior sliding characteristics of each washer can be used to rotate the end of the supply roller and the inner surface of the seal member during rotation of the supply roller. Friction resistance generated between them can be remarkably reduced.
[0059]
[0060]
As described above, the present invention relates to a toner supply roller which reduces frictional resistance while effectively preventing toner leakage between a toner supply roller disposed in a developing device and a seal member contacting both ends thereof. It is possible to provide a developing device in an image forming apparatus capable of preventing an increase in rotational torque of the image forming apparatus.
[0061]
Claim5In the image forming apparatus, the washer member in which the roller shaft of the supply roller is inserted in the developing device is disposed at a position where the seal member and both ends of the roller shaft body and the roller material are in contact with each other. The seal member and the roller are rotated during the rotation of the supply roller while preventing the toner from leaking by making the peripheral end of the roller material and the seal member contact with each other without making the member and the roller shaft and both ends of the roller material almost contact each other. It is possible to reduce the frictional resistance generated between the shaft body and the roller material.
[0062]
In particular, if the outer diameter of the washer member is set to be larger than the shaft diameter of the roller shaft member, the roller shaft member is brought into contact with the washer member without directly contacting the seal member, thereby further reducing frictional resistance when the supply roller rotates. It is possible to do.
[0063]
As a result, the frictional resistance is reduced and the rotational torque of the toner supply roller is increased while effectively preventing the leakage of the toner between the toner supply roller disposed in the developing device and the seal contacting both ends of the toner supply roller. It is possible to realize an image forming apparatus capable of preventing such a situation.
Further, in the image forming apparatus according to the sixth aspect, since both end surfaces of the roller material in the supply roller extend outside the both end surfaces of the roller shaft, both end surfaces of the roller shaft are connected to the washer member and the seal member. Without direct contact, the both end surfaces of the roller material and the seal member are brought into contact, whereby it is possible to reduce the contact area between the both end portions of the supply roller and the seal member, thereby reducing frictional resistance. . Further, since the end surface of the roller member is always in contact with the inner surface of the seal member, it is possible to reliably prevent the toner from inadvertently leaking from the supply roller to the developing roller.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of main components of a laser printer.
FIG. 2 is a side sectional view of the laser printer.
FIG. 3 is a side sectional view of a process unit.
FIG. 4 is a front sectional view showing the inside of a developing chamber.
FIG. 5 is an explanatory diagram schematically showing a contact state between a toner supply roller and a side seal member.
FIG. 6 is an explanatory diagram schematically showing another contact state between the toner supply roller and the side seal member.
FIG. 7 is an explanatory view schematically showing still another contact state between the toner supply roller and the side seal member.
FIG. 8 is an explanatory view schematically showing still another contact state between the toner supply roller and the side seal member.
FIG. 9 is an explanatory diagram schematically showing a main part of a conventional developing device.
FIG. 10 is a perspective view showing a main part of a conventional developing device.
FIG. 11 is an explanatory diagram illustrating a case where a gap is generated between a toner supply roller and a side seal member in a conventional developing device.
FIG. 12 is an explanatory diagram showing a case where an end portion of a toner supply roller and a side seal member are excessively pressed in a conventional developing device.
[Explanation of symbols]
1 Body case
3 Process unit
12 Photoconductor drum
20 Toner supply roller
20A roller shaft
20B Roller shaft
20C Roller material
21 Toner cartridge
21A toner supply port
25 Unit frame
34 Lower Auger Roller
35 Upper Auger Roller
37 Upper seal member
38 Side seal member
39 Support plate
40 washers
D Development room
D1 Shaft diameter of roller shaft
Outer diameter of D2 washer
D3 Roller diameter of toner supply roller
P laser printer

Claims (6)

Rotatably disposed in the developing chamber, a feed roller formed by covering a roller member on the periphery of the roller shaft having the roller shaft,
A developing roller that carries toner on the outer peripheral surface via the supply roller and develops the electrostatic latent image on the photosensitive drum with the toner;
A seal member having a shaft hole into which the roller shaft is inserted while being in contact with both ends of the roller shaft and the roller material in the supply roller,
The roller shaft is inserted and provided with two washer members disposed at locations where the seal member and the roller shaft body and both ends of the roller material are in contact with each other ,
The developing device according to claim 1, wherein the two washer members are formed by punching a film sheet, and burrs generated on a side opposite to a punching direction are arranged to contact the seal member and the roller member, respectively. An outer diameter of said washer member, a developing apparatus according to claim 1, characterized in that it is smaller than the roller diameter of larger and the supply roller than the shaft diameter of the roller shaft member. The roller member and the seal member is a developing device according to claim 1 or claim 2, characterized in that it is formed from a sponge material. In a developing device having a supply roller formed by coating a roller material around a roller shaft having a roller shaft, and a developing roller that develops an electrostatic latent image on the photosensitive drum with toner supplied from the supply roller,
Seal members disposed on both sides of the roller shaft and the roller material in the supply roller ,
It comprises two washer members which are arranged at positions where the roller shaft is inserted and the seal member and the roller shaft body and both ends of the roller material are in contact with each other,
By extending both end surfaces of the roller material outside the both end surfaces of the roller shaft body, the both end surfaces of the roller material and the sealing member are brought into contact ,
The developing device according to claim 1, wherein the two washer members are formed by punching a film sheet, and burrs generated on a side opposite to a punching direction are arranged to contact the seal member and the roller member, respectively. Rotatably disposed in the developing chamber, a feed roller formed by covering a roller member on the periphery of the roller shaft having the roller shaft, carrying the toner to the outer circumferential surface via the feed roller, the photosensitive drum An image forming apparatus including a developing device having a developing roller that develops an electrostatic latent image with the toner,
A seal member having a shaft hole into which the roller shaft is inserted while being in contact with both ends of the roller shaft and the roller material in the supply roller,
Provided with two washer member in which the roller shaft is disposed at a position where the both end portions of the sealing member and the roller shaft member and the roller member is in contact with the inserted,
The image forming apparatus according to claim 1, wherein the two washer members are formed by punching a film sheet, and burrs generated on a side opposite to a punching direction are arranged to contact the seal member and the roller member, respectively . A developing device having a supply roller formed by coating a roller material around a roller shaft having a roller shaft; and a developing roller for developing an electrostatic latent image on the photosensitive drum with toner supplied from the supply roller. In the image forming apparatus,
  Seal members disposed on both sides of the roller shaft and the roller material in the supply roller,
  It comprises two washer members which are arranged at positions where the roller shaft is inserted and the seal member and the roller shaft body and both ends of the roller material are in contact with each other,
  By extending both end surfaces of the roller material outside the both end surfaces of the roller shaft body, the both end surfaces of the roller material and the sealing member are brought into contact,
The two washer members are formed by punching a film sheet, and have a direction opposite to a punching direction. An image forming apparatus, wherein burrs generated on the side are arranged so as to abut against the seal member and the roller member, respectively.

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