JP2017111244A - Toner supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a pressure relief effect over a long period of time in a toner replenishment container, and to suppress toner from scattering.SOLUTION: A toner replenishment device, which includes: a toner bottle that stores toner inside, and discharges the toner from an opening part; a toner hopper part that provisionally accumulates the toner from the toner bottle; and a pressure relief filter member that is provided in the toner hopper part, supplies the toner of the toner hopper part to an external developing device due to rotation of a toner conveyance member. The pressure relief filter member is provided in a part more upper than a supply port supplying the toner to the developing device from the toner hopper part, and includes: a filter part that serves as an air vent; and a filter protection member that has a thin plate sheet overlapped in a part of the filter part. A tip end part of the toner conveyance member is configured to abut against the filter protection member only.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a toner replenishing container used in an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a multifunction machine having a plurality of functions.

  In an electrophotographic apparatus applied to a copying machine, a facsimile, a laser beam printer, etc., an electrostatic latent image is formed by charging a photoconductor as an image carrier and exposing a manuscript image or writing light according to an image signal. Then, the electrostatic latent image formed on the photosensitive member is developed and visualized by a developing device, and then the visible image (toner image) on the photosensitive member is transferred to a transfer material such as transfer paper by a transfer unit and fixed. An image is obtained by fixing with an apparatus.

  One of the developing device methods is a two-component developing method using a developer composed of toner and a carrier, and the toner is consumed when the electrostatic latent image is visualized. When the amount of toner in the developer decreases, it is necessary to replenish the toner to the developing device, so the toner for replenishment is replenished by the toner replenishing device. This toner replenishing device is provided with a toner storage container in which toner is stored in a detachable manner, and is replaced with a new toner storage container when the toner becomes empty. There is a cylindrical toner bottle in the toner storage container. The cylindrical main body, a bottom sealed at one end of the main body, and a toner discharge narrowed at the other end of the main body And a mouth.

  An inner wall from the cylindrical main body portion to the mouth portion is provided with a toner conveying spiral groove formed continuously from the bottom body portion to the mouth portion. The movement of the spiral groove accompanying the rotation of the toner bottle feeds the toner in the main body from the mouth toward the toner hopper.

  The toner hopper is a sealed space. Since the air flows in by the rotation of the sleeve and screw in the developing device, the internal pressure may increase significantly in some cases, and toner scattering may occur from the gap around the replenishing port of the toner bottle.

  Normally, the gap around the toner bottle refill port is sealed with a packing seal, so if the internal pressure does not increase, the toner will not scatter, but if the internal pressure inside the toner hopper increases, the seal contact will be weak. A toner passage is formed, and the toner is easily scattered through the portion. If the toner scatters for a long period of time, the toner replenishing device including the toner bottle and the inside of the device are contaminated with toner, which causes the operator to stain his hands and clothes when replacing the toner.

  In order to prevent toner scattering due to such an increase in internal pressure, several methods for reducing the internal pressure by providing a pressure relief filter have been proposed. For example, in Patent Document 1, a pressure relief filter is provided in a toner conveyance portion that connects a toner hopper portion and a developing device.

  However, in this configuration, when there is a large amount of toner remaining in the toner bottle, the toner may be biased, and a toner peak may be formed on the path from the toner bottle to the toner transport unit. In this case, the path from the toner bottle to the toner conveying unit is sealed with a toner pile, and air does not flow to the depressurizing filter, so that the depressurizing effect cannot be maintained. Further, in this system, the place where the pressure relief filter is attached is located above the screw where the replenished toner is agitated.

  The toner replenished from the toner hopper to the developing device is stirred and charged by the screw, but the toner immediately after replenishment may not have sufficient charge rise, and the toner is likely to scatter.

  In the case where the filter is provided in the toner conveying portion that connects the toner hopper portion and the developing device in this way, the filter is easily clogged by the scattered toner, and particularly when the filter is once clogged, the effect of depressurization is extremely high. There is a problem that it drops.

  In order to prevent such clogging of the pressure release filter, a method of rubbing the pressure release filter with an agitator mylar (a registered trademark of DuPont, terephthalic acid polyester) as in Patent Document 2 has been proposed. The configuration of the developing device is as shown in FIG. 12, and a pressure release filter is provided on the upper portion of the toner hopper. The toner is stored in the toner hopper, and the toner in the toner is stirred by an agitator and sent to the toner supply port side. The purpose is to prevent clogging of the filter by rubbing the pressure release filter by the tip mylar of the agitator that stirs the toner.

  However, the charged toner in the toner hopper is attached to the agitator tip mylar, and the stirring member rubs the entire width of the filter. For this reason, when the toner adheres to the tip of the Mylar, the toner is rubbed against the filter, and conversely, the toner is clogged, so that the pressure releasing effect cannot be maintained and the toner is likely to be scattered. was there.

  When a pressure relief filter is provided in the toner conveyance part connecting the toner hopper part and the developing device (for example, Patent Document 1), when a toner peak is formed in the path from the toner bottle to the toner conveyance part, the pressure relief is performed. There is a disadvantage that the effect cannot be maintained and toner scattering is likely to occur.

  On the other hand, when a pressure release filter is provided on the upper part of the toner hopper (for example, Patent Document 2), there is an effect on the internal pressure release, but the filter is easily clogged, and the pressure release effect of the filter cannot be maintained over a long period of time. There was a drawback.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to maintain a pressure relief effect of a filter over a long period in a toner supply container and suppress toner scattering.

  One embodiment of the present invention that achieves the above object includes a toner bottle that contains toner therein and discharges the toner from an opening, a toner hopper that temporarily accumulates toner from the toner bottle, and the toner hopper. A depressurizing filter member, and a toner replenishing device that supplies toner from the toner hopper to an external developing device by rotation of a toner conveying member, wherein the depressurizing filter member is disposed from the toner hopper. The toner conveying member includes a filter portion that is provided above a supply port that supplies toner to the developing device and serves as an air vent, and a filter protection member in which a thin sheet is stacked on a part of the filter portion. The tip of the abutment is in contact with only the filter protection member.

  According to the present invention, in the toner replenishing container, it is possible to maintain the pressure relief effect of the filter for a long period of time and to suppress toner scattering.

It is a principal part schematic of embodiment by this invention. FIG. 6 is a perspective view showing a toner supply device 8 according to the embodiment. FIG. 4 is a cross-sectional view for explaining a configuration of a toner supply device 8 according to the embodiment. It is a figure which shows the preferable modification (the 1) of the structure of FIG. It is a figure which shows the preferable modification (the 2) of the structure of FIG. FIG. 4 is a view for explaining “the tip of the toner conveying member 22” in the embodiment. It is a figure which shows the detailed structure of the "pressure relief filter 25" in the said embodiment. It is FIG. (1) for demonstrating the effect | action of the structure of the "pressure relief filter 25" in the said embodiment. It is FIG. (2) for demonstrating the effect | action of the structure of the "pressure relief filter 25" in the said embodiment. FIG. 6 is a diagram for explaining another example of “the tip of the toner conveying member 22” in the embodiment. It is a figure for demonstrating the structure of the principal part of another embodiment by this invention. It is a figure (the 1) which shows an example of a prior art. It is FIG. (2) which shows an example of a prior art. It is FIG. (3) which shows an example of a prior art.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic diagram of a main part of the image forming apparatus of the present embodiment.
The image forming apparatus of this embodiment is an image forming apparatus using an electrostatic copying process, such as a copying machine, a facsimile machine, a printer, and the like. In the following examples, a two-component monochrome copying machine is shown. The invention can also be applied to a one-component developing copier, monochrome printer, FAX and two-component developing, or one-component developing color copier and color printer.

  In the figure, a charging device 2, an exposure device 3, a developing device 4, a transfer device 5, a cleaning device 6, a charge eliminating device 7, and a toner replenishing device 8 are provided around a drum-shaped photoconductor 1 as an image carrier. . Further, as illustrated, the toner replenishing device 8 has an opening 8a.

  The photoreceptor 1 is driven to rotate by a driving device (not shown), and the surface thereof is charged to a predetermined polarity by the charging member of the charging device 2 of the proximity charging method. The charged surface of the photosensitive member 1 is exposed by the exposure device 3 to form an electrostatic latent image corresponding to the image information.

  This electrostatic latent image is developed with toner as a developer supplied from the developing device 4 to the surface of the photoreceptor 1 to be visualized as a toner image. The toner of the developing device 4 is supplied from the toner replenishing device 8, and the mechanism thereof will be described in detail later.

  Further, the visible image on the surface of the photoconductor 1 is transferred to a recording sheet by the transfer device 5, and the surface of the photoconductor 1 after the transfer is cleaned by the cleaning device 6. Next, the toner replenishing device 8 which is toner replenishing means in the present embodiment will be described.

FIG. 2 is a perspective view showing the toner supply device 8 of the present embodiment.
The toner replenishing device 8 includes a toner bottle 20 that is removable as a toner container, and a toner hopper 21 that conveys toner discharged from the toner bottle 20 to the developing device 4. When the toner bottle 20 is attached or detached, the operation is performed by sliding the toner hopper 21 in the direction of arrow B after operating the lever 26.

The toner replenishing operation in this embodiment will be described with reference to FIGS.
The image forming apparatus consumes toner when visualizing the electrostatic latent image, and detects the toner consumption by a sensor (not shown). There are several methods for detecting the toner consumption, and there are known methods for detecting the toner density, which is the ratio of the toner and the carrier, and for optically detecting the image on the photoreceptor. When it is detected that the toner is consumed, the toner bottle 20 is rotated to replenish the toner according to the toner consumption.

  The toner discharged from the opening 8a to the toner hopper 21 by the rotation of the toner bottle 20 of the toner replenishing device 8 is moved on the inner wall of the toner hopper 21 by the rotational movement of the toner conveying member 22 in the direction of arrow C (see FIG. 1). Then, it is discharged from the supply port 23. The toner conveying member 22 is made by adhering a sheet of Mylar (trade name of DuPont: terephthalic acid polyester) with a double-sided tape or an adhesive. (Not shown)

  The toner discharged in this way passes through the toner conveying section 24 that connects the toner hopper 21 of the toner replenishing device 8 and the developing device 4, and is located above the toner replenishing side screw 13 of the developer containing section 10. 14 to the inside of the developing device 4.

  The gap is sealed with a packing seal in order to prevent the toner from splashing outside in the process (toner hopper to developing device) until the toner is charged into the developing device. The toner may be scattered due to leakage.

Hereinafter, the internal pressure increase mechanism will be described in detail.
The toner conveying section 24 and the toner hopper section 21 of the developing device are hermetically sealed spaces, but a small amount of outside air is sucked by the rotation of the developing roller 11 in the developing device, and the developing roller side screw 12, Since the toner replenishment side screw 13 flows into the toner hopper section 21 from the toner transport section 24 (air flows in), the internal pressure inside the sealed space increases.

  When a large amount of toner is supplied to the toner transport unit 24 when the internal pressure is increased in this way, the air inside the toner transport unit 24 does not escape and the gap between the toner hopper unit 21 and the toner bottle 20 and the seal contact are weak. However, a toner passage is formed, and the toner is likely to be scattered (toner ejection) through the portion. As a case where a large amount of toner is replenished, a document having a high image area may be printed or continuous printing may be performed. This is because a large amount of toner is temporarily replenished because more toner is consumed than in normal printing.

  In addition, as a case where a large amount of toner is supplied, there is a toner end recovery operation after the toner bottle 20 is replaced. Normally, when the amount of toner in the toner bottle 20 decreases, the toner cannot be replenished sufficiently, and the toner density decreases. For this reason, the toner concentration in the developer or the toner image on the photosensitive member is optically detected by the sensor, and when a certain condition is reached (it is recognized that the concentration is low), printing is forcibly stopped. .

  At this time, since the operator panel displays that toner replacement is necessary (toner end), the operator removes the empty toner bottle 20 and replaces it with a new toner bottle 20. After the toner bottle 20 has been replaced, it is necessary to restore the lowered toner density to a constant density. After supplying a certain amount of toner, the developing device is driven for several tens of seconds to several minutes in order to stabilize the charging of the toner and the carrier. Operation (toner end recovery).

  Such a toner bottle is attached / detached at the time of toner replacement. However, the toner bottle may be attached / detached even in the rare case where there is a remaining amount of toner. In this case, toner scattering may occur. For example, there is a case where the user toner remaining amount is visually confirmed or a serviceman performs maintenance inspection. When the lever 26 is operated when the toner bottle 20 is attached or detached, the inner plug of the toner bottle 20 is opened and closed (not shown). When the toner bottle 20 is taken out, the inner plug that has been opened closes at once, so that the internal pressure of the toner bottle 20 suddenly increases, so that the toner around the toner bottle 20 opening from the gap between the toner hopper portion 21 and a place where the seal contact is weak. Toner splashes.

  If the toner scatters for a long period of time, the toner replenishing device including the toner bottle and the inside of the device will be contaminated with toner. When toner adheres to the path, it causes printing stains.

  In order to prevent toner scattering due to such an increase in internal pressure, a pressure relief filter is provided on the upper portion (for example, Patent Document 1) of the toner conveying unit 24 and the upper portion of the toner tank (for example, Patent Document 2). FIG. 13 shows an embodiment thereof, in which a filter 25 is provided at a position 24b of the toner conveying portion 24.

  A base material such as a woven fabric or a non-woven fabric made of polyester, polypropylene, or polyethylene terephthalate resin is used for the pressure release filter. The depressurizing filter collects only the toner floating in the space and releases air to the outside of the developing device and the toner hopper when the internal pressure of the toner transport unit 24 and the toner hopper 21 increases.

  This reduces the internal pressure and prevents toner scattering from gaps around the replenishing port and areas where the seal contact is weak. However, the depressurization filter is unavoidably clogged with toner. Since the removal effect is reduced, the toner scattering tends to deteriorate gradually.

  For this reason, a maintenance work is usually required in which a service person replaces or cleans the filter during regular visits. On the other hand, in the disclosure described below, a pressure relief filter is provided on the upper portion of the toner bottle portion, and the pressure relief filter has a double structure of the filter portion and the filter protection member, and only the filter protection member is rubbed by the toner conveying mylar. I am doing so. Examples will be described in detail below.

<Example 1>
Next, an example (Example 1) of the pressure release filter and the toner conveying mylar according to the present embodiment and effects thereof will be described. In the above-described configuration in which the pressure release filter 25 is provided on the upper portion of the toner conveying unit 24 (for example, Patent Document 1), when the toner remaining in the toner hopper 21 is large as shown in FIG. In some cases, a crest may be formed, and the crest of toner becomes a lid, so that air does not flow to the depressurization filter, and the depressurization effect cannot be maintained. If the toner supply operation is performed in such a state, the internal pressure of the toner hopper 21 cannot be released.

  Therefore, in this embodiment, as shown in FIG. 3, the pressure release filter 25 is provided on the upper portion of the toner hopper portion 21, but is positioned above the supply port 23 in terms of position. Therefore, in this configuration, even when a toner pile is formed at the supply port 23, the pressure of the toner hopper 21 can be released.

  As described above, the scattering of toner from the toner replenishing device may be caused by an increase in internal pressure accompanying the operation of the lever 26 when the toner is attached or detached. In this embodiment, the internal pressure of the toner hopper 21 can be reduced even in such a case.

  In the first exemplary embodiment, the filter 25 is provided at the apex of the toner hopper portion 21. However, the configuration is not limited thereto. The filter 25 may be mounted at a position that does not overlap the supply port 23, but is preferably above the supply port 23. For example, in the case where a sufficient arrangement space cannot be taken upward by design, it may be arranged shifted to the side surface in the oblique direction as shown in FIG. 4, or may be arranged dispersed in several places as shown in FIG. The effect is obtained.

  The toner conveying member 22 originally has a function for conveying the toner delivered from the toner discharge port of the toner bottle 20 to the supply port 23, and the tip of the toner conveying member 22 has a wall surface 27 inside the toner hopper 21. It is configured to rub. The tip of the toner conveying member 22 means a region (a portion in the drawing) longer than the wall surface 27 of the toner hopper 24 in FIG.

  In the present embodiment, as shown in FIG. 7, the pressure release filter 25 has a double structure of a filter portion 25a and a filter protection member 25b. As shown in FIG. 8, the toner conveying member 22 slides on the filter protection member 25b at the tip. Since this position is also the supply port 23, it also serves as a function of sliding the toner delivery and the filter protection member 25b. The toner conveying member 22 is unavoidably functional because of toner adhesion.

  However, as can be understood from the fact that the arrow E in FIGS. 7 and 11 indicates the range in which the toner conveying member 22 rubs against the filter protection member 25b, the tip of the toner conveyance member 22 contacts when rubbed against the filter protection member. Only the filter protection member 25b is provided so as not to directly contact the filter portion 25a.

  Therefore, unlike the prior art of Patent Document 2, the toner is not rubbed against the filter, and the toner clogged by the filter is removed by vibration when the toner conveying member 22 comes into contact with the filter protection member 25b. (FIG. 9).

The length of the tip end portion a of the toner conveying member 22 was about ^{2 to 5} mm and 0.1 N / cm ² or less was favorable. If the contact pressure is high, the mechanical resistance is increased, and the toner conveying member 22 is likely to be peeled off or broken, so that the mechanical load is reduced as much as possible.

  Further, the tip of the toner conveying member 22 may have a bent portion 28 as shown in FIG. 10 in order to prevent the toner conveying member 22 from being caught on the filter protection member 25b. Thereby, even when there is a minute step or unevenness on the inner wall or the filter protection member, the catch can be prevented.

  In this embodiment, the toner conveying member 22 is a Mylar (DuPont product: terephthalic acid polyester) sheet. A material having the same polarity as the toner is desirable in order to prevent the toner from adhering electrostatically (thickness is 0.3 mm or less for general use). For example, when the charging polarity of the toner is negative, polypropylene, polyester, and polyethylene-based materials that are easily charged to negative polarity are preferable. However, when it is difficult to form a sheet, other materials are used. The surface layer shown may have a double structure made of a material having the same polarity as the charged polarity of the toner. The material of the toner conveying member 22 is not limited to these, and any material that can be easily charged to the same polarity as the toner in the charging series may be used.

  The filter protection member 25b is formed by bonding and integrating a mylar sheet, which is an inexpensive general-purpose material, with the filter portion 25a with a double-sided adhesive member or the like. The material of the filter protection member 25b may be a film sheet or metal thin plate of other polypropylene, polyester, or polyethylene material having elasticity. In the case of a film sheet, a material having a low friction coefficient and easily transmitting vibration is more preferable.

  As described above, the toner conveying member 22 does not directly contact the filter portion 25a, and clogging is prevented by vibration when the toner conveying member 22 contacts the filter protection member 25b. The disadvantage that the pressure release effect of the filter cannot be maintained can be improved, and toner scattering from the seal portion of the toner replenishing device can be prevented over a long period of time.

  In the above embodiment, the pressure release filter has a double structure of the filter portion 25a and the filter protection member 25b. However, the pressure release filter may be constituted by only the filter 25. In this case, in the depth direction of FIG. 11, the filter 25 is provided with a toner conveying member 22, a toner conveying member contact portion 28, and a non-contact portion 29.

  Also in this case, clogging of the non-contact portion 29 is prevented by vibration when the toner transport member 22 contacts the toner transport member contact portion 28. Toner adheres to the toner conveying member contact portion 28, but the non-contact portion 29 is not clogged, so that the internal pressure can be relieved, and the toner scatters from the seal portion of the toner replenishing device for a long period of time. Can be prevented.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 3 Exposure apparatus 4 Developing apparatus 5 Transfer apparatus 6 Cleaning apparatus 7 Electric discharge apparatus 8 Toner replenishing apparatus 8a Opening part 10 Developer accommodating part 11 Developing roller (developer carrier)
DESCRIPTION OF SYMBOLS 12 Developing roller side screw 13 Toner replenishment side screw 14 Toner replenishment port 20 Toner bottle 21 Toner hopper part 22 Toner conveyance member 23 Supply port 24 Toner conveyance part 25 Filter 25a Filter part 25b Filter protection member 26 Lever 27 Wall surface 28 Toner conveyance member contact Part 29 Toner conveying member non-contact part

JP 2006-084487 A Japanese Patent No. 4041650

Claims (7)

A toner bottle for storing toner therein and discharging the toner from the opening;
A toner hopper that temporarily accumulates toner from the toner bottle;
A depressurizing filter member provided in the toner hopper,
A toner replenishing device that supplies toner from the toner hopper to an external developing device by rotation of a toner conveying member;
The depressurizing filter member is provided above the supply port for supplying toner from the toner hopper to the developing device, and a filter portion for removing air, and a filter protection member in which a thin sheet is overlapped on a part of the filter portion A toner replenishing device, wherein a tip of the toner conveying member abuts only on the filter protection member. The toner replenishing device according to claim 1, wherein a contact pressure between the toner conveying member and the filter protection member is 0.1 N / cm ² or less.   The toner replenishing device according to claim 1, wherein a tip portion of the toner conveying member has a bent shape.   4. The toner replenishing device according to claim 1, wherein a contact portion between the toner conveying member and the filter protection member is a charging material having the same polarity as the toner. 5.   The toner replenishing device according to claim 4, wherein the toner conveying member has a surface layer made of the charging material.   6. The toner replenishing device according to claim 1, wherein the depressurizing filter member is provided at a plurality of locations in the toner hopper portion in a range above the supply port. 6. A toner bottle for storing toner therein and discharging the toner from the opening;
A toner hopper that temporarily accumulates toner from the toner bottle;
A depressurizing filter member provided in the toner hopper,
A toner replenishing device that supplies toner from the toner hopper to an external developing device by rotation of a toner conveying member;
The depressurizing filter member is provided above a supply port for supplying toner from the toner hopper to the developing device, and has a portion that does not contact the tip of the toner conveying member in the depth direction. A toner replenishing device.

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