JP7489027B2 - Powder container, developing device, and image forming apparatus - Google Patents

Description

The present invention relates to a powder container, a developing device, and an image forming device.

2. Description of the Related Art Conventionally, powder containers for containing powder for image formation used in image forming apparatuses are known.
For example, Patent Document 1 describes a powder storage container for storing toner as such a powder, which has a layer on the inner wall containing fluorine-containing particles formed by bonding a fluorine compound to the surface of silica particles, and the fluorine-containing particles have a secondary average particle diameter of 20 nm to 48 nm. By providing such a layer, fine irregularities on the inner wall are reduced, thereby reducing toner adhesion, which solves the problem of toner agglomerating and adhering to the inner wall, making it impossible to use up the toner.

However, it is necessary to provide fluorine-containing silica particles, which are silica particles with a secondary average particle size of 50 nm or less and have a fluorine compound bonded to the surface, on the inner wall to a thickness of, for example, 0.3 to 3 μm, which increases costs.

In order to solve the above-mentioned problems, the present invention provides a powder storage container for use in an image forming device that can be fitted with a powder storage container containing powder for image formation, and that is equipped with a conveying tube having a powder receiving inlet for receiving powder from the powder storage container, and that rotates the fitted powder storage container, the powder storage container having a rotatable powder storage section that contains powder for image formation, a conveying tube receiving member that has a tube insertion inlet into which the conveying tube can be inserted and is provided within a container opening of the powder storage section, and a pumping surface that pumps up powder on the container opening side and supplies it to the powder receiving inlet as the powder storage section rotates, the powder storage section being provided with a DLC coating on an inner wall surface, and the pumping surface having a portion where the DLC coating is absent or where the DLC coating is thinner than other portions .

The present invention has the excellent effect of suppressing toner adhesion to the inner wall while suppressing increases in costs compared to conventional methods.

FIG. 2 is a vertical cross-sectional view of a specific example of the toner supply device according to the embodiment. FIG. 1 is a schematic diagram of a copying machine according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a schematic configuration of an image forming unit of the copying machine. FIG. FIG. 4 is an explanatory diagram of the front end of the toner container with the front end cover of the container removed; FIG. FIG. FIG. 4 is a perspective view of a specific example of a pumping portion of the toner container. 3A to 3C are schematic diagrams illustrating the manufacturing process of the toner container. 1 is a graph showing the relationship between DLC film thickness and moisture resistance.

Hereinafter, an embodiment of the present invention will be described in which the present invention is applied to a copying machine (hereinafter, referred to as a copying machine 500) as an image forming apparatus.
2 is a schematic diagram of a copying machine 500 according to this embodiment. The copying machine 500 is made up of a copying machine main body (hereinafter referred to as a printer unit 100), a paper feed table (hereinafter referred to as a paper feed unit 200), and a scanner (hereinafter referred to as a scanner unit 400) attached to the printer unit 100.

A toner container housing section 70 is provided at the top of the printer section 100. Four toner containers 32 (Y, M, C, K) corresponding to each color (yellow, magenta, cyan, black) are installed in this toner container housing section 70 as powder containers that contain toner, which is powder for image formation, and are removable (replaceable). An intermediate transfer unit 85 is disposed below the toner container housing section 70.

The intermediate transfer unit 85 is composed of an intermediate transfer belt 48, four primary transfer bias rollers 49 (Y, M, C, K), a secondary transfer backup roller 82, multiple tension rollers, an intermediate transfer cleaning device, etc. The intermediate transfer belt 48 is stretched and supported by multiple roller members, and moves endlessly in the direction of the arrow in FIG. 2 by the rotational drive of the secondary transfer backup roller 82, which is one of the multiple roller members.

In the printer unit 100, four image forming units 46 (Y, M, C, K) corresponding to each color are arranged side by side so as to face the intermediate transfer belt 48. In addition, four toner supply devices 60 (Y, M, C, K) corresponding to each of the four toner containers 32 (Y, M, C, K) are arranged below the four toner containers 32 (Y, M, C, K). The toner contained in the toner containers 32 (Y, M, C, K) is supplied (replenished) by the corresponding toner supply devices 60 (Y, M, C, K) into the developing devices (powder-using units) of the image forming units 46 (Y, M, C, K) corresponding to each color.

As shown in FIG. 2, the printer unit 100 also includes an exposure device 47, which is a latent image forming means, below the four image creating units 46. The exposure device 47 exposes the surface of the photoconductor 41, which will be described later, based on image information of the original image read by the scanner unit 400 or image information input from an external device such as a personal computer, and forms an electrostatic latent image on the surface of the photoconductor 41. The exposure device 47 included in the printer unit 100 uses a laser beam scanner method using a laser diode, but other configurations such as an LED array may also be used as the exposure means.

Figure 3 is a schematic diagram showing the general configuration of the imaging unit 46Y corresponding to yellow. The imaging unit 46Y is equipped with a drum-shaped photoconductor 41Y, which is a latent image carrier. Furthermore, the imaging unit 46Y is configured such that a charging roller 44Y, which is a charging means, a developing device 50Y, which is a developing means, a photoconductor cleaning device 42Y, a static eliminator, etc. are arranged around the photoconductor 41Y. Then, an image creation process (charging process, exposure process, development process, transfer process, cleaning process) is performed on the photoconductor 41Y, and a yellow image is formed on the photoconductor 41Y.

The other three imaging units 46 (M, C, K) are configured in a similar manner to the imaging unit 46Y corresponding to yellow, except that they use different colors of toner, and images of the colors corresponding to the respective toners are formed on the respective photoconductors 41 (M, C, K). The following explanation will be given using the imaging unit 46Y corresponding to yellow as an example.

The photoconductor 41Y is driven to rotate in the clockwise direction in FIG. 3 by a drive motor. Then, at a position facing the charging roller 44Y, the surface of the photoconductor 41Y is uniformly charged (charging process). The surface of the photoconductor 41Y then reaches a position irradiated with the laser light L emitted from the exposure device 47, and an electrostatic latent image corresponding to yellow is formed by exposure scanning at this position (exposure process). The surface of the photoconductor 41Y then reaches a position facing the development device 50Y, and the electrostatic latent image is developed at this position to form a yellow toner image (developing process).

The four primary transfer bias rollers 49 (Y, M, C, K) of the intermediate transfer unit 85 sandwich the intermediate transfer belt 48 between the photoconductors 41 (Y, M, C, K) to form a primary transfer nip. A transfer bias opposite to the polarity of the toner is applied to the primary transfer bias rollers 49 (Y, M, C, K).

The surface of the photoconductor 41Y on which the toner image is formed in the development process reaches the primary transfer nip that faces the primary transfer bias roller 49Y across the intermediate transfer belt 48, and the toner image on the photoconductor 41Y is transferred to the intermediate transfer belt 48 at this primary transfer nip (primary transfer process). At this time, a small amount of untransferred toner remains on the photoconductor 41Y. The surface of the photoconductor 41Y, which has transferred the toner image to the intermediate transfer belt 48 at the primary transfer nip, reaches a position facing the photoconductor cleaning device 42Y. At this facing position, the untransferred toner remaining on the photoconductor 41Y is mechanically collected by the cleaning blade 42a (cleaning process). Finally, the surface of the photoconductor 41Y reaches a position facing the charge removal device, and the residual potential on the photoconductor 41Y is removed at this position. In this way, a series of image formation processes performed on the photoconductor 41Y are completed.

This image creation process is performed in the other image creation units 46 (M, C, K) in the same way as in the yellow image creation unit 46Y. As a result, the toner images of each color on each photoconductor 41 (Y, M, C, K) are primarily transferred onto the intermediate transfer belt 48 in a superimposed manner, forming a color toner image on the intermediate transfer belt 48.

The intermediate transfer belt 48, on which the toner images of each color are transferred and superimposed, reaches a position facing the secondary transfer roller 89. At this position, the secondary transfer backup roller 82 sandwiches the intermediate transfer belt 48 between itself and the secondary transfer roller 89 to form a secondary transfer nip. The color toner image formed on the intermediate transfer belt 48 is then transferred onto a recording medium P, such as transfer paper, that has been transported to the position of the secondary transfer nip. The recording medium P transported to the secondary transfer nip is transported from the paper feed tray 26 of the paper feed unit 200, which is disposed below the printer unit 100, via the paper feed roller 27, the pair of registration rollers 28, etc.

After passing through the secondary transfer nip, untransferred toner that has not been transferred to the recording medium P remains on the intermediate transfer belt 48. When the surface of the intermediate transfer belt 48 reaches a position facing the intermediate transfer cleaning device, the untransferred toner on the surface is collected by the intermediate transfer cleaning device, and the series of transfer processes performed on the intermediate transfer belt 48 is completed.

The recording medium P onto which the color toner image has been transferred at the secondary transfer nip is transported to the position of the fixing device 86. In the fixing device 86, the color toner image transferred to the surface is fixed onto the recording medium P. After passing through the fixing device 86, the recording medium P passes between the rollers of the pair of discharge rollers 29 and is discharged outside the device. The recording medium P discharged outside the device is stacked in sequence on the stack section 30. In this way, a series of image formation processes in the copier 500 is completed.

Next, the developing device 50 in the image forming unit 46 will be explained using the image forming unit 46Y corresponding to yellow as an example. As shown in FIG. 3, the developing device 50Y is composed of a developing roller 51Y, a doctor blade 52Y, two developer transport screws 55Y, and a toner concentration detection sensor 56Y. The two developer transport screws 55Y are arranged in the two developer storage units (53Y, 54Y).

The first developer storage section 53Y and the second developer storage section 54Y store two-component developer G consisting of carrier and toner. The second developer storage section 54Y is connected to the toner drop transport path 64Y through an opening formed above it. The toner concentration detection sensor 56Y detects the toner concentration in the developer G in the second developer storage section 54Y.

Next, we will explain the toner supply device 60 (Y, M, C, K) (toner transport device) (powder transport device). Figure 4 is a schematic diagram showing the state in which the toner container 32Y is installed in the toner supply device 60Y.

The toner in each toner container 32 (Y, M, C, K) installed in the toner container storage unit 70 (see FIG. 2) of the printer unit 100 is appropriately replenished into each developing device 50 (Y, M, C, K) according to the toner consumption in each color developing device 50 (Y, M, C, K). At this time, the toner in each toner container 32 (Y, M, C, K) is replenished by a toner replenishing device 60 (Y, M, C, K) provided for each toner color.

The toner supply device 60 (Y, M, C, K) is equipped with a toner container storage section in which the toner container 32 can be attached, and a transport nozzle 611 (Y, M, C, K) as a transport pipe having a nozzle opening 610 as an inlet for receiving toner from the toner container 32. A transport screw 614 (Y, M, C, K) is provided inside the transport nozzle 611. The transport nozzle 611 is connected to a toner drop transport path 64 (Y, M, C, K). The toner supply device 60 (Y, M, C, K) also includes a container rotation drive unit 91 (Y, M, C, K), etc.

When the toner container 32Y, which is a powder container, moves in the direction of the arrow Q in FIG. 4 and is attached to the toner container storage section of the printer unit 100, the conveying nozzle 611Y of the toner replenishing device 60Y is inserted from the tip side of the toner container 32Y in conjunction with the attachment operation. This allows communication between the inside of the toner container 32Y and the inside of the conveying nozzle 611Y.

The toner container 32Y is a substantially cylindrical toner bottle. It is composed of a container tip cover 34Y that is held non-rotatably in the toner container storage section of the toner replenishing device 60, and a container body 33Y that is integrally formed with a container gear 301Y. The container body 33Y is held rotatably relative to the container tip cover 34Y.

When the main body cover installed on the front side of the copier 500 (the front side in the direction perpendicular to the paper surface of FIG. 2) is opened, the insertion port of the toner container storage unit is exposed. Then, with the longitudinal direction of each toner container 32 (Y, M, C, K) in the horizontal direction, the toner containers 32 (Y, M, C, K) are attached and detached from the front side of the copier 500 (the attachment and detachment operation is performed with the longitudinal direction of the toner container 32 as the attachment and detachment direction). Note that the set cover 608Y in FIG. 4 is part of the toner container storage unit.

With the container tip cover 34Y attached to the toner container storage section, a rotational drive is input from the container rotation drive section 91Y, which is composed of a drive motor, drive gears, etc., to the container gear 301Y provided on the container body 33Y. This causes the container body 33Y to rotate in the direction of arrow A in FIG. 4. As the container body 33Y itself rotates, the toner contained inside the container body 33Y is transported from the right side to the left side in FIG. 4 along the longitudinal direction of the container body by the helical protrusion 302Y formed in a helical shape on the inner peripheral surface of the container body 33Y.

The container body 33 has a pumping section on the container tip cover side (right side in the figure) that pumps up the toner transported to the container tip cover side by rotating the container body 33. This pumping section pumps up the toner above the transport nozzle 611 inserted into the toner container, and the toner falls into the nozzle opening 610Y provided at the toner container side end of the transport nozzle 611Y, supplying the toner into the transport nozzle 611.

A transport screw 614Y is disposed inside the transport nozzle 611Y, and when rotational drive is input from the container rotation drive unit 91Y to the transport screw gear 605Y, the transport screw 614Y rotates and transports the toner supplied into the transport nozzle 611Y. The downstream end of the transport nozzle 611Y in the transport direction is connected to the toner drop transport path 64Y, and the toner transported by the transport screw 614Y falls under its own weight through the toner drop transport path 64Y and is replenished into the developing device 50Y (second developer storage unit 54Y).

Each toner container 32 (Y, M, C, K) is replaced with a new one when it reaches the end of its life (when the toner contained therein has been almost completely consumed and is empty). A handle portion 303 is provided on the end of the toner container 32 opposite the container tip cover 34 in the longitudinal direction, and when replacing the toner container 32, the worker can remove the installed toner container 32 by grasping the handle portion 303 and pulling it out.

The control unit 90 may calculate the amount of toner consumed based on the image information used by the exposure device 47 described above, and may determine that toner needs to be supplied to the developing device 50Y. The control unit 90 may also detect that the toner concentration in the developing device 50Y has decreased based on the detection result of the toner concentration detection sensor 56Y. In these cases, the control unit 90 controls the container rotation drive unit 91Y to rotate and rotate the container body 33Y and the transport screw 614Y of the toner container 32Y for a predetermined time, thereby replenishing toner to the developing device 50Y.

A specific example of the toner container 32 will be described. This example has basically the same structure as the example disclosed in Patent Document 4. FIG. 5 is a perspective view of the toner container 32. FIG. 6 is an explanatory diagram of the tip of the toner container 32 with the container tip cover 34 removed. FIG. 6(a) is a vertical cross section, and FIG. 6(b) is a vertical cross section with the nozzle receiver 330 removed. As shown in FIG. 5, the container tip cover 34 covers the periphery of one end of the container body 33, and is formed with an opening that exposes the container opening 33a at one end of the container body 33, and a gear exposure opening 34a that exposes the container gear 301.

As shown in FIG. 6(b), the toner container 32 with the container tip cover 34 removed is composed of the container body 33 and the nozzle receiver 330 that forms the nozzle receiving port 331. The container body 33 is substantially cylindrical and is configured to rotate around the central axis of the cylinder as the axis of rotation. The direction parallel to this axis of rotation is called the "rotational axis direction", and in the rotational axis direction, the side of the toner container 32 where the nozzle receiving port 331 is formed (the side where the container tip cover 34 is located) is called the "container tip side". In addition, the side of the toner container 32 where the handle portion 303 is located (the side opposite the container tip side) is called the "container rear end side".

The longitudinal direction of the toner container 32 is the direction of the rotation axis, and when the toner container 32 is attached to the toner supply device 60, the direction of the rotation axis is horizontal. The outer diameter of the rear end side of the container body 33 from the container gear 301 is larger than that of the front end side of the container, and a spiral protrusion 302 is formed on the inner peripheral surface.

On the inner wall of the container body 33 at the container tip side, a pumping section 304 is formed, which pumps up the toner conveyed to the container tip side by the spiral protrusion 302 as the container body 33 rotates in the direction of the arrow A in the figure, by the rotation of the container body 33. The pumping section 304 pumps up the toner that has entered the internal space opposite the pumping section 304 by the conveying force of the spiral protrusion 302, by the pumping surface 3040 in response to the rotation of the container body 33. This makes it possible to pump up the toner above the inserted conveying nozzle 611 (see FIG. 1). In addition, a pumping section spiral protrusion 304a formed in a spiral shape is formed on the inner peripheral surface of the pumping section 304 so as to convey the toner inside in the same way as the spiral protrusion 302. A specific example of the detailed configuration of the pumping section 304 will be described later.

A container gear 301 is formed on the container body 33, further toward the container tip side than the pumping portion 304. A part of this container gear 301 (the rear side in FIG. 5) is exposed from the gear exposure opening 34a and is configured to mesh with a container drive gear 601 on the toner supply device 60 side.

A cylindrical container opening 33a is formed on the container body 33, further toward the container tip side than the container gear 301. The nozzle receiver 330 can be fixed to the container body 33 by pressing the receiver fixing portion 337 of the nozzle receiver 330 into this container opening 33a. The toner container 32 is configured such that after toner is filled into the container body 33 through the opening of the container opening 33a, the nozzle receiver 330 is fixed to the container opening 33a of the container body 33.

A cover claw hook 306 is formed on the end of the container opening 33a of the container body 33 on the container gear 301 side. By attaching the container tip cover 34 from the container tip side (left side in FIG. 5), the container body 33 penetrates the container tip cover 34 in the rotation axis direction, and the cover claw 341 provided on the upper part of the container tip cover 34 hooks on the cover claw hook 306. By hooking the cover claw 341, the container body 33 and the container tip cover 34 are attached so that they can rotate relatively. The cover claw hook 306 may be formed separately from the container body 33 and configured to be detachable from the container body 33.

The nozzle receiving member 330 is composed of a container shutter support member 340, a container shutter 332, a container seal 333, and a container shutter spring 336. The container shutter support member 340 is composed of a shutter rear end support portion 335, a shutter side support portion 335a, and a receiving member fixing portion 337, and the container shutter spring 336 is composed of a coil spring.

The container shutter 332 is composed of a tip cylindrical portion 332c, a sliding portion 332d, a guide rod 332e, and a shutter removal prevention claw 332a. The tip cylindrical portion 332c is a portion on the tip side of the container that is in close contact with the cylindrical opening (nozzle receiving port 331) of the container seal 333. The sliding portion 332d is a cylindrical portion formed on the rear end side of the container from the tip cylindrical portion 332c, has a slightly larger outer diameter than the tip cylindrical portion 332c, and slides on the inner circumferential surface of a pair of shutter side support portions 335a. The guide rod 332e is a rod portion that is inserted inside the coil of the container shutter spring 336 to guide the container shutter spring 336 so that it does not buckle. The shutter removal prevention claw 332a is provided at the end opposite to the upright root of the guide rod 332e, and prevents the container shutter 332 from falling off the container shutter support member 340.

Since the container shutter spring 336 is inserted in a compressed state between the tip cylindrical portion 332c and the shutter rear end support portion 335, the container shutter 332 receives a biasing force in a direction away from the shutter rear end support portion 335 (toward the container tip). The shutter removal prevention claw 332a formed on the end of the container shutter 332 on the container rear end side catches on the outer wall surface of the shutter rear end support portion 335. This prevents the container shutter 332 from moving in a direction away from the shutter rear end support portion 335.

The positioning is achieved by the hooking of the shutter removal prevention claw 332a onto the shutter rear end support portion 335 and the biasing force of the container shutter spring 336. More specifically, the tip cylindrical portion 332c, which exerts the toner leakage prevention function of the container shutter 332, and the container seal 333 are positioned in the axial direction relative to the container shutter support member 340. The two are positioned in a tight contact relationship, preventing toner leakage.

Figure 7 is an explanatory diagram of the tip side of the toner container. Figure 7(a) is an oblique view, Figure 7(b) is a view observed from the container opening side, and Figure 7(c) is a view observed from the side. The container is equipped with a cylindrical container opening 33a formed at one axial end of the container body 33 and having an inner diameter smaller than the container body 33, a spiral protrusion 304a, and a pumping section 304 arranged on the inner side of the container body 33 (the other axial end side, the container rear end side) of the container opening 33a. The pumping section 304 has a pumping surface 3040 that pumps up the toner transported by the spiral projection 304a as the container body 33 rotates in the direction of the arrow A in the figure above the nozzle opening 610 (powder receiving port) of the transport nozzle 611 (transport pipe) inserted from the container opening 33a, and then drops it into the nozzle opening 610, and an inner diameter side wall surface 308 that is connected to the inner diameter side edge of the pumping section 304 and extends in a direction intersecting with the pumping surface 3040.

The pumping surface 3040 is a surface that extends in a direction intersecting the rotation direction of the container body 33. The pumping surface 3040 includes an inner diameter side edge 3041 that extends from the container opening 33a along the axial direction toward the rear end of the container, an outer diameter side edge 3042 that is located on the outermost peripheral surface side of the container body 33 and extends from the container top surface 307 (or its vicinity) along the axial direction toward the rear end of the container, and a front end side edge 3043 and a rear end side edge 3044 that respectively connect the front ends and rear ends of the inner diameter side edge 3041 and the outer diameter side edge 3042. The axial front end surface of the container body 33 is referred to as the container top surface 307.

In the illustrated example, the container top surface 307 is substantially perpendicular to the axial direction, but the container top surface may be an inclined surface extending toward the rear end of the container. The inner diameter side wall surface 308 is a surface having a portion that extends a predetermined length from the inner edge of the container opening 33a toward the other end in the axial direction. In the example of FIG. 7, the container gear 301 and the cover claw hook portion 306 are formed as separate members from the container body 33, and FIG. 7 shows the state in which this separate member has been removed. This separate member is integrated with the container body 33 by a female screw 33b formed on the outer periphery of the container opening 33a (see FIG. 7(c)).

Figures 7(d) and 7(e) are explanatory diagrams of the function of the pumping unit 304. They are cross-sectional views of the tip end side of the toner container 32, showing the B-B cross section of Figure 7(c). The pumping surface 3040 is indicated by a reference line drawn from the inner wall surface side. The pumping surface 3040 temporarily holds the toner T and lifts it above the nozzle opening 610 as the container body 33 rotates in the direction of arrow A (Figure 7(d)). In addition, the pumping unit 304 drops the pumped toner from the inner diameter side edge 3041 toward the nozzle opening 610 as the container body 33 rotates (Figure 7(e)).

The inclination angle of the pumping surface 3040 relative to the nozzle opening 610 is set so that when the angle of the pumping surface 3040 reaches the angle of repose of the toner, the extension surface (extension line) extending from the upper surface of the pumping surface 3040 toward the rotation axis R (or the nozzle opening 610) is located between the rear edge of the nozzle opening 610 in the width direction (the edge of the nozzle opening 610 in the width direction located on the side away from the pumping surface 3040) and the center of the nozzle opening 610 in the width direction (the position corresponding to directly above the rotation axis R of the toner container 32).

Figure 8 is a perspective view of a specific example of the pumping section. This specific example has basically the same structure as the example disclosed in Patent Document 5. It is a perspective view cut along the C-C cross section of Figure 6(a) and viewed from the rear end side of the container. The rotation angle and viewing angle are different between Figure 8(a) and Figure 8(b). The same reference numerals are given to the inner diameter side edge 3041, the outer diameter side edge 3042, the tip side edge 3043, and the rear side edge 3044, which correspond to the four sides of the rectangular pumping surface 3040 shown in Figure 7(a). The same reference numerals are also given to the inner diameter side wall surface 308, the container opening 33a, and the container top surface 307. Note that the example shown in Figure 8 differs from the example in Figure 7 in the position of the pumping section spiral protrusion 304a relative to the pumping surface 3040, etc. Reference numeral 301 denotes a container gear 301. Figure 8(b) also shows a partially enlarged view of the surface of the pumping surface 3040, which will be described later.

1 is a vertical cross-sectional view showing a specific example of a toner supply device 60 corresponding to the specific example described in Figures 5 to 7. 612 indicates a nozzle shutter flange, 608 indicates a set cover, 602 indicates a frame, 603 indicates a drive motor, 91 indicates a container rotation drive unit, 604 indicates a drive transmission gear, 605 indicates a conveying screw gear, 607 indicates a nozzle holder, 64 indicates a toner drop conveying path, 614 indicates a conveying screw, 613 indicates a nozzle shutter spring, 612 indicates a nozzle shutter, and 611 indicates a conveying nozzle. The nozzle shutter 612 closes the nozzle opening 610 formed in the conveying nozzle 611 when the toner container 32 is not installed before it is installed, and opens the nozzle opening 610 when the toner container 32 is installed. When the toner container is attached to the toner container storage unit 70, the tip of the conveying nozzle 611Y of the toner replenishing device 60Y is inserted from the tip side of the toner container 32Y while pushing the container shutter 332 into the inside of the toner container 32. This allows communication between the inside of the toner container 32Y and the inside of the conveying nozzle 611Y.

Next, the inner wall of the toner container, which is a characteristic feature of this embodiment, will be described. Toner used in electrophotographic image forming devices is a consumable item, and is replaced when it is detected that the toner inside the toner container is empty. In recent years, toner has been fixed at lower temperatures, which has led to the problem that toner adheres to the inner wall of the toner container and cannot be used up to the end. In particular, toner containers that rotate a spiral-shaped container body and supply toner to a conveying screw installed in an image forming device cannot scrape off toner that has adhered to the inside of the container, so as the toner container rotates, the toner gets caught on the uneven shape of the container and adheres to it.

Therefore, in the toner container of this embodiment, a DLC (diamond-like carbon) coating is provided on the inner wall. In other words, a DLC coating layer is formed on the inner wall surface. As described in Patent Document 2, DLC has the effect of reducing toner adhesion when coated on the developing roller. Similarly, the high releasability of DLC is applied to the toner container. By coating the toner container (PET resin), the adhesion force of the toner to the container can be reduced. As a result, toner adhesion to the inner wall of the toner container is reduced, and the amount of toner remaining when replacing the toner can be reduced.

The method of applying DLC to a toner container can be a method using a plasma CVD device as described in Patent Document 3. Figure 9 is a schematic diagram of the manufacturing process. In Figure 9(a), a nozzle 551 is inserted into the container 550 after blow molding the toner container to supply a hydrocarbon gas as a raw material gas. A cathode electrode and the like are arranged inside and outside the container 550. The raw material gas is supplied to the inside by the nozzle 551, and high-frequency power is supplied to the cathode electrode to generate plasma 552 by plasma discharge (Figure 9(b)), and a film is formed. The reference numeral 553 in Figure 9(c) indicates the formed film. Other gases can be added to the film, and for example, adding fluorine can improve the releasability compared to a film made of DLC alone. The longer the film formation time, the thicker the film can be.

The toner container 32 has spiral grooves (302, 304a), so it is difficult to form a film in the grooves. If there are any areas that are not coated, toner will adhere to them, so it is preferable to coat all areas that come into contact with the toner. If the film-forming time is increased, there will be no uncoated areas, but the toner container will deform due to heat. Therefore, the film-forming time is set so that the grooves are reliably coated and the bottle does not deform. Because plasma discharge is used, there is almost no need for material costs, and coating can be done at low cost.

DLC coating also has the property of being difficult for oxygen to pass through. Figure 10 is a graph showing the relationship between DLC film thickness and moisture resistance. The horizontal axis is the time left standing, and the vertical axis is the relative humidity. Toner containers with different film thicknesses were moved from an environment with a temperature of 23 degrees and a relative humidity of 50% to an environment with a temperature of 40 degrees and a relative humidity of 70% and left standing for 20 days, and the increase in humidity inside the container was compared. With a DLC film thickness of 50 nm, the humidity was equivalent to the environmental humidity after 20 days, while with a DLC film thickness of 100 nm, the humidity remained low, and moisture resistance was improved by ensuring a DLC coat thickness of 100 nm or more. The thicker the film, the higher the moisture resistance, but if the film formation time is extended to increase the film thickness, the container will deform due to heat, so a thickness of 100 nm or more and 200 nm or less is preferable.

The toner container 32 has a tube insertion opening into which a transport tube can be inserted, a transport tube receiving member provided within the container opening of the powder storage section, and a powder pumping surface 3040 that pumps up the powder on the container opening side and supplies it to the powder receiving port as the powder storage section rotates. In this type of toner container 32, the toner is divided into two functions: a part that transports toner along a spiral groove, and a pumping part that pumps up the transported toner and supplies it to the transport tube. By giving each part an optimal surface condition, it is possible to achieve better stabilization of the supply amount and reduction of the remaining amount. Specifically, it is as follows.

If DLC coating is not performed, toner will adhere to the entire inner wall of the toner container 32. If toner adheres to the spiral groove, not only will it remain as residual toner, but the groove will become shallower, reducing the amount of toner transported and the amount of toner replenished. DLC coating has the effect of making toner less likely to adhere, reducing the amount of toner remaining. On the other hand, applying DLC coating to the pumping section can cause inconvenience, so to avoid this, it is preferable not to apply DLC coating to the pumping section.

The inconvenience, the reason for its occurrence, and the countermeasures are as follows. When replenishing toner from a toner container, the toner container rotates, and toner is pumped up to the pumping surface 3040 as shown in FIG. 7(d). When the rotation of the toner container 32 brings the pumping surface 3040 above the horizontal as shown in FIG. 7(e), toner is supplied from the pumping surface 3040 to the nozzle opening 610. In such a toner container 32, it is important that the toner pumped up onto the pumping surface 3040 does not fall as the pumping surface 3040 moves from bottom to top. If the friction between the pumping surface 3040 and the toner is extremely low, most of the toner will spill out before the pumping surface moves from bottom to top, and the toner cannot be replenished.

A measure to prevent this is to perform DLC coating on all areas except the pumping surface 3040. This not only reduces toner adhesion, but also ensures a stable supply amount. In order to prevent the pumping surface 3040 from being DLC coated, the pumping surface 3040 can be masked with a masking material prior to the DLC coating formation process, and this masking material can be removed after the DLC coating is formed.

In order to avoid the corresponding decrease in the number of toner containers produced due to the increased effort of attaching and detaching the mask to the toner container, the following can be done. The pumping surface 3040 (the inner wall surface of the container) is given an uneven shape and then a thin DLC coating is applied. As an example of this uneven shape, a partial enlarged view of the surface of the pumping surface 3040 is also shown in FIG. 8(b). This uneven shape is made by forming countless hemispherical convex or concave portions. The uneven shape can be a few microns. Because of the fine unevenness, the film is less likely to become thicker than in other places. In addition, because the thickness of the DLC coating is 200 nm or less, the unevenness will not cause the toner to slip off even when coated. Therefore, it is possible to achieve the effects of reducing the remaining amount and stabilizing the amount of replenishment without the effort of masking the pumping portion.

As described above, the toner container 32 in the embodiment is one that contains powder toner as a powder for image formation, but it can also be used to contain powder carrier for a two-component developer, or a premix developer in which the powder carrier and powder toner are mixed so that the toner ratio is higher than in the developing device.

The above description is merely an example, and the present invention provides unique effects for each of the following aspects.
(Aspect 1)
The toner container 32 as a powder storage container according to this embodiment has a DLC coating on the inner wall surface, so that the toner can be prevented from adhering to the inner wall while suppressing an increase in cost compared to the conventional case.

(Aspect 2)
The toner container 32 has a container body 33 which is a rotatable powder storage section that stores powder for image formation, a nozzle receiver 330 which is provided in the container opening of the powder storage section and serves as a transport tube receiver having a tube insertion port into which a transport tube can be inserted, and a powder pumping surface 3040 which pumps up the powder on the container opening side and supplies it to the powder receiving port as the container body 33 rotates, and a DLC coating is provided on the inner wall surface of the powder storage section. This makes it possible to prevent toner from adhering to the rotating powder storage section.

(Aspect 3)
In addition, the toner container 32 has portions on the inner wall surface that have different functions and have different thicknesses of the DLC coating. Since the required toner transportability differs depending on the location, by setting the required film thickness for each portion, the supply amount becomes stable and the remaining amount becomes small.

(Aspect 4)
Further, the toner container 32 has a DLC coating that is not present on the pumping surface 3040 or that is thinner than other portions, thereby preventing the toner from slipping off the pumping surface and ensuring a stable supply amount.

(Aspect 5)
Further, the toner container 32 has an uneven shape on the pumping surface 3040. Therefore, in order to prevent the pumping surface from being coated with DLC, it is necessary to mask the surface beforehand during film formation. However, if the pumping surface is provided with unevenness, it becomes difficult to coat the surface, and therefore there is no need to mask the surface during film formation.

(Aspect 6)
The toner container 32 has a DLC film thickness of 100 to 200 nm. By making the coating film thicker, not only is adhesion prevention achieved, but the moisture-proofing effect is also enhanced, so that the quality of the toner can be maintained even after long-term storage.

26: Paper feed tray 27: Paper feed roller 28: Pair of registration rollers 29: Pair of paper discharge rollers 30: Stack section 32: Toner container 32Y: Toner container 33: Container body 33Y: Container body 33a: Container opening 33b: Screw 34: Container front end cover 34Y: Container front end cover 34a: Gear exposure opening 41: Photoconductor 41Y: Photoconductor 42Y: Photoconductor cleaning device 42a: Cleaning blade 44Y: Charging roller 46: Imaging section 47: Exposure device 48: Intermediate transfer belt 49: Primary transfer bias roller 49Y: Primary transfer bias roller 50: Development device 50Y: Development device 51Y: Development roller 0052: Paragraph 52Y: Doctor blade 53Y: First developer container 54Y: Second developer container 55Y: Developer transport screw 56Y : toner concentration detection sensor 60 : toner supply device 60Y : toner supply device 64 : toner drop transport path 64Y : toner drop transport path 70 : toner container storage section 82 : secondary transfer backup roller 85 : intermediate transfer unit 86 : fixing device 89 : secondary transfer roller 90 : control section 91 : container rotation drive section 91Y : container rotation drive section 100 : printer section 200 : paper feed section 301 : container gear 301Y : container gear 302 : spiral projection 302Y : spiral projection 303 : handle section 304 : pumping section 304a : pumping section spiral projection 306 : cover claw hook section 307 : container top surface 308 : inner diameter side wall surface 330 : nozzle receiving member 331 : nozzle receiving port 332 : container shutter 332a : shutter removal prevention claw 332c : Tip cylindrical portion 332d : Sliding portion 332e : Guide rod 333 : Container seal 335 : Shutter rear end support portion 335a : Shutter side support portion 336 : Container shutter spring 337 : Receiving member fixing portion 340 : Container shutter support member 341 : Cover claw portion 400 : Scanner portion 500 : Copy machine 550 : Container 551 : Nozzle 552 : Plasma 601 : Container drive gear 605Y : Conveying screw gear 608Y : Set cover 610 : Nozzle opening 610Y : Nozzle opening 611 : Conveying nozzle 611Y : Conveying nozzle 612 : Nozzle shutter 614 : Conveying screw 614Y : Conveying screw 3040 : Pumping surface 3041 : Inner diameter side edge 3042 : Outer diameter side edge 3043 : Leading edge 3044 : Trailing edge A : Arrow G : Developer L : Laser light P : Recording medium R : Rotation axis T : Toner

Patent No. 4331196 JP 2013-148813 A Patent No. 6517994 JP 2018-45149 A Patent No. 6464627

Claims (6)

A powder container that contains powder for image formation can be attached to the image forming apparatus.
A powder container for use in an image forming apparatus that includes a conveying pipe having a powder receiving port for receiving powder from the powder container, and that rotates the attached powder container,
a rotatable powder container that contains the powder for image formation;
a conveying tube receiving member provided within a container opening of the powder storage unit, the conveying tube receiving member having a tube insertion opening into which the conveying tube can be inserted;
a pumping surface that pumps up the powder on the container opening side and supplies it to the powder receiving port by rotating the powder storage portion,
A DLC coating is provided on an inner wall surface of the powder container,
A powder storage container, characterized in that the DLC coating is not present on the pumping surface or has a portion where the DLC coating is thinner than other portions. The powder storage container according to claim 1 ,
A powder storage container, characterized in that the pumping surface is provided with an uneven shape. The powder storage container according to claim 1 or 2 ,
A powder storage container, characterized in that the DLC film has a thickness of 100 to 200 nm. 4. The powder container according to claim 1, which contains powder for image formation. A developing device comprising the powder container according to claim 4 . An image forming apparatus comprising the developing device according to claim 5 .

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