JP4179931B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus equipped with a toner cartridge for supplying toner to a developing device such as a printer or a copying machine.
[0002]
[Prior art]
In this type of image forming apparatus, an electrostatic latent image is formed on a photosensitive member by laser light irradiation, toner is adsorbed to the electrostatic latent image to form a visible image, and this is printed on recording paper. Yes. The toner supply to the image forming apparatus is performed by a toner cartridge that can be attached to and detached from the main body of the image forming apparatus.
[0003]
By the way, in an image forming apparatus capable of high-speed printing and copying, a large capacity toner cartridge is required, but a long box type is generally used due to installation space limitations. In such a toner cartridge, a toner supply port for supplying toner to the developing device is formed along the longitudinal direction. However, in order to prevent toner leakage before being attached to the image forming apparatus, a seal member is attached to the toner cartridge. The supply port is sealed.
[0004]
However, if the user accidentally peels off the seal member before mounting to the image forming apparatus, the toner leaks from the toner supply port and soils the floor, so the seal member is automatically attached after mounting to the image forming apparatus. A toner cartridge to be removed has been proposed (see Patent Document 1).
[0005]
In this toner cartridge, the toner supply port is sealed in the width direction at one end of a wide sealing member, and the other end of the sealing member is fixed to the drive shaft of the stirring member. However, in this method, since the sealing member is wound in the width direction and peeled off at a stroke, not only the starting torque of the stirring member becomes very large, but also the sealing member after winding remains in the toner cartridge. It can also cause sound.
[0006]
Therefore, a toner cartridge is proposed in which a seal member is pasted from one end of the toner supply port along the longitudinal direction of the toner cartridge, folded back at the other end of the toner supply port and returned to one end, and the tip of the folded portion is pulled to peel off. Has been.
For example, in the toner cartridge disclosed in Patent Document 2, a seal member winding chamber is formed in the toner cartridge, and a driving shaft of the stirring member is passed through the winding chamber, and the sealing member is wound and peeled off by the driving shaft. Yes.
In the toner cartridges of Patent Documents 3 and 4, a seal member winding roller is installed on the end surface, and the seal member is wound and peeled off by this roller.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 3-221981 [Patent Document 2]
JP-A-9-244371 [Patent Document 3]
JP 2002-55517 A [Patent Document 4]
JP-A-9-288425 [0008]
[Problems to be solved by the invention]
However, the former toner cartridge has a problem that the amount of toner that can be filled by the volume of the seal member take-up chamber is reduced, so that the cartridge needs to be replaced more frequently and the cost is increased.
On the other hand, the latter toner cartridge has a problem in that the mechanism is complicated and the cost is high because the seal member winding roller needs to be connected and driven by the drive shaft of the stirring member.
[0009]
SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can simplify a winding mechanism of a seal member without reducing the volume of a toner cartridge .
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention seals a toner supply port formed along the longitudinal direction of a long box-shaped toner cartridge main body containing toner therein with a seal member. In an image forming apparatus in which a toner cartridge that is wound around a drive shaft of a stirring member and separated from the toner cartridge body is attached to a developing device ,
In the toner cartridge, a toner supply port is formed in a side surface portion of the toner cartridge body, and the toner supply port faces the toner receiving port of the developing device.
The toner cartridge body includes a toner supply roller for supplying toner in the toner cartridge body toward the developing device and a drive shaft thereof, a toner stirring member for stirring the stored toner, and a drive shaft thereof, and the toner supply. A seal member that sticks from the surface side of the toner cartridge main body and closes before supplying the toner to the developing device;
The supply roller and the shaft end portion of the drive shaft of the stirring member are provided so as to protrude from the end surface of the toner cartridge body, and one end of the seal member is fixed to the protruding portion of the shaft end portion of the drive shaft of the stirring member ,
A slack imparting portion for imparting a predetermined slack to the middle portion of the seal member, and a guide for twisting the seal member so that the seal member is wound around the shaft end portion of the drive shaft with the sticking surface of the seal member facing inward provided the parts on the end face of the toner cartridge main body,
The drive shaft of the stirring member and the drive shaft of the toner supply roller are configured to be driven separately,
After the toner cartridge is mounted on the developing device, driving of the drive shaft of the stirring member is started to stir the toner contained in the toner cartridge body by the stirring member, and the drive shaft of the stirring member is sealed The member is wound while absorbing the slack from the slack imparted portion by the slack imparting portion, and when the slack disappears, the seal member begins to peel from the cartridge body, and the seal member is wound by the drive shaft. The driving of the toner supply roller is started after the peeling of the toner is finished, and only the stirring member is driven after the toner cartridge is mounted until the sealing member is completely peeled off. An image forming apparatus.
[0011]
According to such a configuration, the seal member peeled from the toner cartridge main body is twisted by the guide portion, and is wound around the drive shaft of the stirring member with its sticking surface inside. That is, since the seal member is wound up by using a conventional drive shaft of the stirring member, it is not necessary to provide a new winding mechanism, and the manufacturing cost can be reduced. Further, since the seal member is wound up by the drive shaft of the stirring member protruding from the end surface of the toner cartridge main body, the volume of the toner cartridge main body is not reduced, and there is no possibility of generating abnormal noise.
[0012]
One end of the seal member is preferably fixed to a connecting member for power transmission provided at the tip of the drive shaft, and the seal member is wound around the connecting member .
In this case, since the seal member is wound around the connecting member, the protruding amount of the drive shaft from the end surface of the toner cartridge main body is reduced, which is advantageous for securing the volume of the toner cartridge main body.
[0013]
In the present invention, fixed to the drive shaft of the sealing member is provided on the end surface of the toner cartridge main body slack applying unit that applies a predetermined slack to the sealing member.
[0014]
In the present invention, the stirring member can be driven separately from the toner replenishing member, and only the stirring member is driven after the toner cartridge is mounted until the seal member is completely peeled off. . In this case, only the stirring member can be driven until the peeling of the seal member is completed, and the toner replenishing member need not be driven wastefully.
When the toner cartridge is mounted on the image forming apparatus, the toner is hard, so that the driving torque required for the stirring is large. This torque decreases as the toner fluidizes when the stirring member rotates several times. In other words, if the seal member is not loosened and the seal member is peeled off at the same time as the stirring of the toner, an initial torque for stirring the toner on the drive shaft of the stirring member and a torque for peeling the seal member from the toner cartridge are used. Both are needed at once.
Therefore, by giving the seal member predetermined slack by the slack imparting portion , most of the driving torque is used for stirring the toner while the slack is wound up. Since the driving torque is reduced after the stirring is sufficiently performed, the maximum torque necessary for the driving source is set low by starting the peeling of the seal member from here.
[0015]
The slack imparting portion is preferably a passage that folds and stores the seal member in the middle.
In this case, until the seal member is pulled out from the passage, only the toner is stirred, and thereafter the peeling of the seal member is started. That is, the length of the seal member stored in the passage is slack.
[0016]
It is preferable that a peripheral wall portion is provided on the end surface of the toner cartridge body so as to surround the drive shaft, and an opening is formed in the peripheral wall portion to insert the seal member.
In this case, since the seal member wound around the drive shaft of the stirring member is accommodated in the peripheral wall portion, the periphery of the drive shaft is not soiled by the toner attached to the seal member.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows the overall configuration of an image forming apparatus (copier) according to the present embodiment.
This copying machine forms an image by a well-known electrophotographic method. The photosensitive drum 1 is charged by a charging device 2 and then an electrostatic latent image is formed by irradiation of a laser beam from a laser exposure device 3. To do. The developing device 4 agitates a two-component developer composed of a carrier and toner, and attaches toner to the electrostatic latent image on the photosensitive drum 1 to form a toner image. The toner image on the photosensitive drum 1 is transferred onto the sheet conveyed from the sheet feeding unit 6 to the transfer device 5. The sheet on which the toner image has been transferred is conveyed to the fixing device 7 where the toner image is fixed and discharged from the copying machine.
[0019]
FIG. 2 shows the developing device 4 and the toner cartridge 8 in an enlarged manner. The toner cartridge 8 rotates the toner supply roller 47 to drop the toner from the toner supply port 72 into the developing device 4. The toner cartridge 8 has a large capacity corresponding to high-speed copying, and has a cross section twice or more that of the developing device 4. For this reason, the toner cartridge 8 includes first and second toner storage portions 12 and 13, and stirring members 10 and 11 are installed in the toner storage portions 12 and 13.
[0020]
FIG. 3 is a schematic diagram showing a system configuration of the developing device 4. The developing device 4 is based on a dry two-component magnetic brush developing method using a developer in which toner and a carrier are mixed. That is, the developing device 4 develops the electrostatic latent image formed on the photosensitive drum 1 to form a visible image, and includes a developing device 40 filled with a developer composed of toner and carrier. .
[0021]
The developing device 4 includes a toner concentration control system 60 for controlling the toner concentration, and supplies the toner in the toner cartridge 8 to the developer in the developing device 40 to keep the toner concentration constant. In the developing device 40, a toner density sensor 41, a developing roller 44, a stirring roller 45, and a toner supply roller 43 are provided. The toner supply roller 43 supplies the toner sent from the toner cartridge 8 to the stirring roller 45.
[0022]
The agitating roller 45 agitates the developer (carrier and toner) in the developing device 40 and frictionally charges the toner and the carrier. The developing roller 44 supplies the mixed and stirred developer to the photosensitive drum 1. In the developing roller 44, a magnet roller in which a plurality of magnet bodies for generating a magnetic field are fixed is inserted in a developing sleeve formed into a hollow cylinder from a nonmagnetic metal such as aluminum alloy, brass, SUS304 stainless steel or the like. . The developing roller 44 magnetically attracts the developer onto the surface while rotating only the developing sleeve, and conveys and supplies the developer to the developing unit in contact with the photosensitive drum 1. The stirring roller 45 and the developing roller 44 are rotationally driven by a driving device (not shown) upon receiving an instruction from the control CPU 61.
[0023]
The toner concentration control system 60 includes a toner concentration sensor (magnetic permeability sensor) 41, a reference voltage generation unit 62, a comparator 63, a toner supply roller driving unit 64, a toner supply motor 65, a control CPU 61, and the like. The toner concentration sensor 41 is installed below the developing device (mixing and stirring chamber) 40 of the developing device 26, detects the toner concentration of the developer in the developing device 46, and outputs it as a voltage (concentration detection voltage). The reference voltage generator 62 generates a reference voltage to be compared with the concentration detection voltage. This reference voltage represents the reference concentration of the developer in the developing device 40.
[0024]
The comparator 63 compares the density detection voltage with the reference voltage, and outputs a drive signal to the toner supply roller drive unit 64 if the toner density in the developing device 40 is low. The toner supply roller driving unit 64 drives a toner supply motor 65 that is a rotational drive source of the toner supply roller (toner supply member) 47 while receiving a drive signal. The RAM temporarily stores the read output voltage of the toner density sensor 41 and the like. The ROM stores programs such as toner density control.
[0025]
Incidentally, in this type of developing device 4, a magnetic permeability sensor 41 is generally used as a toner concentration sensor, but a differential transformer type toner concentration sensor 41 as described below can also be used.
FIG. 4 shows a configuration of a control circuit in the case where the differential transformer type toner density sensor 41 is used.
The toner concentration sensor 41 includes a primary coil 51, a reference coil 52, a detection coil 53, an AC power supply 54, a screw core 55, a phase comparison circuit 57, and a smoothing circuit 58. An AC power supply 54 is connected to the primary coil 51. The reference coil 52 and the detection coil 53 on the secondary side are wound in reverse polarity with substantially the same number of turns and are connected in series.
[0026]
A high permeability screw core 55 is inserted between the primary coil 51 and the reference coil 52 so as to act as a magnetic core. By adjusting the position of the screw core 55, the mutual inductance of the primary coil 51 and the reference coil 52 is reduced. Can be adjusted. When the developer 56 flows between the primary coil 51 and the detection coil 53, the developer 56 acts as a magnetic core to change the mutual inductance between the primary coil 51 and the detection coil 53. Since the size is determined by the amount of magnetic particles of the developer 56 or magnetic toner acting as a magnetic core, the carrier concentration, which is the amount of magnetic particles, can be measured by the output voltage of the detection coil 53.
[0027]
Since the reference coil 52 and the detection coil 53 are connected in series with approximately the same number of turns and opposite polarity, the difference between the coils 52 and 53 can be extracted as an output. The AC voltage supplied to the primary coil 51 and the outputs of the reference coil 52 and the detection coil 53, which are secondary coils, are exclusive ORed by the phase comparison circuit 57, and the output signal is smoothed by the smoothing circuit 58. And is taken out as a DC voltage and input to the toner replenishing roller driving unit 64.
[0028]
As shown in FIG. 5, the toner cartridge 8 is composed of a long box-shaped toner cartridge main body 8a, and a step portion 8b is formed along the longitudinal direction on the side surface thereof, and a toner supply port is formed in the step portion 8b. 72 (shown in FIG. 2) is formed. As shown in FIG. 7, the drive shafts 10a, 11a, 47a of the toner supply roller 47 are projected from the end surface 8c of the toner cartridge body 8a, and a connecting member 75 for power transmission is provided at the tip. -77 are provided.
[0029]
A rib 80 is erected on the end surface 8c of the toner cartridge main body 8a. The rib 80 has a peripheral wall 81 that surrounds the connecting member 75 of the stirring member 11 and a dead end that gives a predetermined slack to the seal member 70. A passage portion 82 and a mountain-shaped conveyance guide portion 83 that detours the connecting member 76 and conveys the seal member 70 are formed. An opening 84 for passing the seal member 70 is formed in the peripheral wall portion 81. The toner supply port 72 is closed by adhering a seal member 70 to the surface of the toner cartridge main body 8a. The seal member 70 is attached from one end of the toner supply port 72 toward the other end, folded back at the other end side, and wound around the connecting member 75 of the stirring member 11.
[0030]
On the end surface 8c of the toner cartridge main body 8a, a guide portion (a dotted line frame in FIG. 7) imparts a twist of 90 degrees to the seal member 70 so that the seal member 70 is wound around the connecting member 70 with the sticking surface inside. Although it is provided at position A, it is well known and is not shown). The seal member 70 that has passed through the guide portion is guided by the conveyance guide portion 83 to enter the passage portion 82, is turned back halfway, is pulled out from the passage portion 83, and is fixed to the connecting member 75 of the stirring member 11.
[0031]
A polymer sheet such as PET is preferably used for the sealing member 70 in terms of strength and cost. The thickness is preferably about 10 to 200 μm. If it is thinner than this, the sealing strength is low, the sealing performance cannot be guaranteed, and there is a risk of damage during winding. On the other hand, when it is thicker than 200 μm, the waist of the seal member 70 becomes strong and it is difficult to wind up. For this reason, for example, a PET base material having a thickness of 0.05 mm and a double-sided adhesive tape attached thereto is used. In addition, what laminated | coated the heat seal material, such as polyethylene, may be used for the single side | surface of the laminate material which has air permeability. When a material having air permeability is used, the gas in the toner cartridge 8 expanded due to a reduced pressure and high temperature environment can be discharged, and the seal member 70 can be prevented from being turned over.
[0032]
When the toner cartridge 8 is attached to the image forming apparatus, the connecting member 75 of the stirring member 11 is engaged with the connecting member 86 of the drive shaft 85 on the image forming apparatus side as shown in FIG. Similarly, the connecting members 76 and 77 of the stirring member 10 and the toner supply roller 47 are also connected to a drive shaft (not shown) on the image forming apparatus side. When the mounting of the toner cartridge 8 is completed, the stirring members 10 and 11 start to be driven, and the seal member 70 is wound around the connecting member 75. As the seal member 70 is wound up, the seal member 70 is pulled out from the passage portion 82 and the slack is absorbed. When the slack disappears, the seal member 70 begins to peel from the toner cartridge body 8a and is peeled off. The sealing member 70 is wound around the connecting member 75 (see FIG. 6). When the peeling of the seal member 70 is completed, the driving of the toner supply roller 47 is started.
[0033]
Since the toner cartridge 8 winds up the seal member 70 using the drive shaft 11a of the stirring member 11, it is not necessary to provide a new winding mechanism, and the manufacturing cost can be reduced, and the toner cartridge main body 8a. Since the seal member 70 is wound up by the drive shaft 11a of the stirring member 11 protruding from the end face 8c, the volume of the toner cartridge main body 8a is not reduced, and there is no possibility of noise.
[0034]
Further, the seal member 70 is wound around the connecting member 75 with the adhesive surface facing inward, and the connecting member 75 is surrounded by the peripheral wall portion 73, so that the drive shaft 11a is driven by the toner adhering to the seal member 70. The neighborhood of is not soiled. Further, since the seal member 70 is wound up by the connecting member 75, the protruding amount of the drive shaft 11a from the end surface of the toner cartridge body 8a is reduced, which is advantageous for securing the volume of the toner cartridge body 8a.
[0035]
By the way, since the seal member 70 is folded back and stored in the passage portion 82, a predetermined slack is imparted to the seal member 70. Therefore, until the slack is eliminated, the drive torque of the drive shaft 11a is equal to that of the toner. Expended in stirring. When the toner cartridge 8 is mounted on the image forming apparatus, the toner is hardened, but the toner is fluidized with the stirring, and the driving torque required for the stirring is reduced.
[0036]
That is, if the seal member 70 is peeled off at the same time as the stirring of the toner in a state where the seal member 70 is not slack, the initial torque for stirring the toner is applied to the drive shaft 11a of the stirring member 11, and the seal member from the toner cartridge 8 Both the torque and the torque for peeling off are required at once. Therefore, by giving the seal member 70 a predetermined slack, most of the driving torque is used for stirring the toner until the slack is wound, and after the stirring is sufficiently performed, the driving torque is reduced. Since it is reduced, the maximum torque required for the drive source is set low by starting the peeling of the seal member 70 from here.
[0037]
Further, the stirring member 11 can be driven separately from the toner supply roller 47, and only the stirring member 11 is driven after the toner cartridge 8 is mounted until the seal member 70 is completely peeled off. Therefore, it is not necessary to drive the toner supply roller 47 wastefully.
[0038]
As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, A various deformation | transformation is possible.
For example, the winding of the seal member 70 may be performed by the drive shaft 10a of the other stirring member 10, and in this case, the arrangement, shape, and the like of the conveyance guide 83 and the passage portion 82 may be changed as appropriate.
[0039]
【The invention's effect】
As described above, according to the present invention, since the seal member is wound using the drive shaft of the stirring member, it is not necessary to provide a new winding mechanism, and the manufacturing cost can be reduced.
Further, since the seal member is wound up by the drive shaft of the stirring member protruding from the end surface of the toner cartridge main body, the volume of the toner cartridge main body is not reduced, and there is an effect that no noise is generated.
[Brief description of the drawings]
FIG. 1 is an overall view showing an image forming apparatus according to the present invention.
FIG. 2 is a diagram illustrating a developing device and a toner cartridge of the image forming apparatus.
FIG. 3 is a diagram illustrating a toner density control system of the image forming apparatus.
FIG. 4 is a diagram showing a differential transformer type toner density control device;
FIG. 5 is a plan view illustrating a method for peeling a seal member from a toner cartridge.
6 is a view showing a state in the middle of peeling of the seal member shown in FIG.
7 is a side view of FIG. 5. FIG.
8 is a side view of FIG. 6. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Photosensitive drum 3 Laser exposure apparatus 4 Developing apparatus 8 Toner cartridge 8a Toner cartridge main body 8b Step part 8c End surface 11 Stirring member 11a Drive shaft 47 Toner supply roller 70 Seal member 75 Connecting member 80 Rib 81 Peripheral wall part 82 Passage part 83 Conveyance guide Portion 85 Drive shaft 86 Connecting member

Claims (4)

A toner supply port formed along a longitudinal direction of a long box-shaped toner cartridge main body containing toner therein is sealed with a seal member, and the seal member is wound around a drive shaft of the agitating member. In an image forming apparatus in which a toner cartridge to be peeled off is attached to a developing device ,
In the toner cartridge, a toner supply port is formed in a side surface portion of the toner cartridge body, and the toner supply port faces the toner receiving port of the developing device.
The toner cartridge body includes a toner supply roller for supplying toner in the toner cartridge body toward the developing device and a drive shaft thereof, a toner stirring member for stirring the stored toner, and a drive shaft thereof, and the toner supply. A seal member that is attached from the surface side of the toner cartridge body before the toner is supplied to the developing device and is closed;
The supply roller and the shaft end portion of the drive shaft of the stirring member are provided so as to protrude from the end surface of the toner cartridge body, and one end of the seal member is fixed to the protruding portion of the shaft end portion of the drive shaft of the stirring member ,
A slack imparting portion that imparts a predetermined slack to the middle portion of the seal member, and a guide that imparts a twist to the seal member so that the sticking surface of the seal member is inside and wound around the shaft end portion of the drive shaft of the stirring member provided the parts on the end face of the toner cartridge main body,
The drive shaft of the stirring member and the drive shaft of the toner supply roller are configured to be driven separately,
After the toner cartridge is mounted on the developing device, driving of the drive shaft of the stirring member is started to stir the toner contained in the toner cartridge body by the stirring member, and the drive shaft of the stirring member is sealed The member is wound up while absorbing the slack from the slack imparted portion at the slack imparting portion, and when the slack disappears, the seal member starts to peel off from the cartridge body, and the seal member is wound up by the drive shaft. The driving of the toner supply roller is started after the peeling of the toner is finished, and only the stirring member is driven after the toner cartridge is mounted until the sealing member is completely peeled off. An image forming apparatus . 2. The seal member according to claim 1, wherein one end of the seal member is fixed to a power transmission connecting member provided at a tip of the drive shaft, and the seal member is wound around the connecting member . Image forming apparatus . The image forming apparatus according to claim 1, wherein the upper Kiyurumi imparting portion is passage for accommodating folded seal member on the way. Provided with a peripheral wall so as to surround the drive shaft to the end surface of the toner cartridge main body, of the claims 1 to 3, characterized that you inserted through the seal member to form an opening in the peripheral wall portion The image forming apparatus according to 1 above.

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