This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2011-005119 filed in Japan on Jan. 13, 2011, the entire contents of which are hereby incorporated by reference.
The present invention relates to a developer container that contains developer, in particular, relates to (i) a developer container that discharges contained developer by being driven to rotate and (ii) an image forming apparatus including the developer container.
In an electrophotographic image forming apparatus, an electrostatic latent image formed on a surface of a photoreceptor is made visible by use of toner (developer) by a developing device. The toner used for making the electrostatic latent image visible is contained in a toner container, and sequentially supplied to the developing device from the toner container.
An image forming apparatus that operates at high speed consumes plenty of toner. Therefore, a toner container having a large volume is used in the image forming apparatus. Among these, a toner cartridge that supplies toner to a developing device by rotation of a toner container has been recently known. Most of such rotation-type toner containers are formed into a hollow cylindrical shape, and have a closed edge part and a discharge opening in the vicinity of the other edge part. The toner container is hereinafter referred to as a toner bottle.
A toner cartridge including a toner bottle is provided in an image forming apparatus such that a rotary shaft of the toner bottle becomes horizontal. Some toner bottles have spiral projections on their inner surfaces. The projections provided on each of the inner surfaces transfer toner toward a discharge opening by rotation of the toner bottle around the rotary shaft, so that the toner is discharged from the discharge opening.
The toner cartridge including the toner bottle further includes, near the discharge opening of the toner bottle, a toner supply section that (i) regulates an upper limit of toner quantity to be discharged from the toner bottle and (ii) discharges a certain amount of toner outside of the toner cartridge. In the toner cartridge including the toner supply section, a toner bottle discharge opening 30 is formed in an edge surface of a toner bottle 20, which edge surface is located in the vicinity of a periphery of the toner bottle 20, as shown in
The toner discharge position regulatory partition 6 allows toner itself contained in the toner bottle 20 to close the toner bottle discharge opening 30 from inside in a case where the toner bottle 20 contains plenty of toner. This prevents outside air from flowing into the toner bottle 20, thereby keeping an inner pressure of the toner bottle 20 so as not to be decreased. Therefore, toner is prevented from being discharged from the toner bottle 20. Consequently, a small amount of toner is discharged.
Patent Literature 1
Japanese Patent Application Publication, Tokukai No. 2007-102135 A (Publication Date: Apr. 19, 2007)
However, according to the conventional technique, it is impossible to stably discharge a certain large amount of toner from a toner cartridge. In particular, it is impossible to stably discharge plenty of toner when a toner bottle starts rotating (during rising edges) or stops rotating (during falling edges).
This brings about a problem that (i) toner to be supplied to a developing device becomes in short supply, (ii) an image defection occurs or (iii) a waiting time for toner supply is prolonged, in a case where an image forming apparatus that operates at high speed is used.
In a case where a rate at which the toner bottle rotates is increased so as to supply plenty of toner, for example, the following problems occur. Cost for obtaining a driving force is risen, or heat is generated due to abrasion or friction of a friction section of the toner bottle.
The present invention was made in view of the problems, and an object of the present invention is to provide (i) a developer container capable of stably supplying a certain large amount of developer and (ii) an image forming apparatus including the developer container.
In order to attain the object, a developer container of the present invention is a developer container, including: a developer vessel, having a cylindrical shape, that carries and discharges developer contained therein through its first discharge opening while the developer vessel is being driven to rotate around a shaft line; and a developer supply section including (i) a temporary storing section which surrounds a periphery of the first discharge opening and temporarily stores the developer discharged from the first discharge opening, (ii) a second discharge opening from which the developer is discharged outside of the developer supply section, and (iii) a carrying section that carries the developer from the temporary storing section toward the second discharge opening, said developer supply section supporting the developer vessel such that the developer vessel can rotate around the shaft line, the developer contained in the developer vessel being discharged outside of the developer container through the first discharge opening and the second discharge opening, and the first discharge opening being formed in an inclined surface of an edge part of the developer vessel, the inclined surface inclining, upstream of a direction in which the developer is carried along the shaft line, so as to be at angles with a surface perpendicular to the shaft line.
According to the configuration, the first discharge opening is formed in the inclined surface of the edge part of the developer vessel. The inclined surface inclines, upstream of the direction in which the developer is carried along the shaft line of the developer vessel, so as to be at angles with the surface perpendicular to the shaft line. Therefore, in a case where the developer vessel contains plenty of developer, the inclined surface makes it easy to stir and flow developer located in the vicinity of the first discharge opening upon the rotation of the developer vessel around the shaft line. The inclined surface also makes it possible to discharge plenty of developer from the developer vessel through the first discharge opening formed in the inclined surface. According to the configuration, it is possible to stably discharge a certain large amount of developer, as compared with a case where the first discharge opening is formed in the surface of the edge part of the developer vessel which surface is perpendicular to the shaft line.
A decrease in amount of developer contained in the developer vessel (i) makes it easy to stir the developer contained in the developer vessel in response to the rotation of the developer vessel and (ii) causes a decrease in time period during which the first discharge opening is closed by the developer contained in the developer vessel. This allows the outside air to easily flow into the developer vessel. Hence, plenty of toner can be continuously discharged.
It is thus possible to stably discharge a certain large amount of developer from the developer container, regardless of quantity of the developer contained in the developer vessel. Further, according to the configuration, the developer container includes the developer supply section which is configured to surround the periphery of the first discharge opening.
This makes it possible to prevent an image forming apparatus from upsizing and cost rise.
The following description will discuss in detail an embodiment of the present invention with reference to drawings.
As shown in
The document reading section 43 is provided in an upper part of the image forming apparatus 100, reads a document, and creates image data of a read document. The image forming section 40 is provided under the document reading section 43, and includes a photoreceptor 44, a charging device 45 and an exposure section 46.
The photoreceptor 44 is a substantially cylindrical electrostatic latent image bearing member that is rotatably provided. The photoreceptor 44 has a surface, on which an electrostatic latent image is formed in accordance with (i) image data created by the document reading section 43 or (ii) image data externally supplied through, for example, a communication network. The charging device 45 is a device that uniformly charges the surface of the photoreceptor 44 so that the surface has a predetermined electric potential. Examples of the charging device 45 encompass a contact roller-type charging device, a contact brush-type charging device, and a non-contact charger-type charging device. The exposure section 46 includes a laser beam scanner, and exposes the photoreceptor 44 charged by the charging device 45 in accordance with image data so as to form, on the surface of the photoreceptor 44, an electrostatic latent image in accordance with the image data.
A cleaning section 49 that removes toner left on the surface of the photoreceptor 44 is provided on the periphery of the photoreceptor 44.
The electrophotographic processing section 60 includes a developing device 47, a transfer section 48 and a fixing section 51. The developing device 47 is a device that supplies toner (developer) onto the surface of the photoreceptor 44 on which surface the electrostatic latent image has been formed, so as to develop a toner image in accordance with the electrostatic latent image. There is provided, over the developing device 47, a toner supply device 10 including (i) a toner hopper 13 and (ii) a toner cartridge 1 that contains toner. The toner hopper 13 is configured to receive toner from the toner cartridge 1. The toner cartridge 1 is later described in detail. The transfer section 48 transfers, to a sheet (recording paper or recording material) fed by the sheet feeding section 50, the toner image on the photoreceptor 44 developed by the developing device 47. The fixing section 51 fixes, onto the sheet, the toner image formed on the sheet. The sheet onto which the toner image has been fixed is discharged onto a paper output tray.
The following description will discuss the toner cartridge (developer container) 1 of the present embodiment. As shown in
The toner bottle 2 includes (i) a cylindrical toner containing section 21, which has a bottom, for containing toner (developer) to be supplied and (ii) a toner bottle discharge opening (first discharge opening) from which the toner contained in the toner containing section 21 is discharged. The toner bottle 2 is driven and rotated around a shaft line L1 so as to carry and discharge the developer contained in the toner containing section 21 from the toner bottle discharge opening 31.
The toner supply section 3 includes (i) a temporary storing section which (a) surrounds a periphery of the toner bottle discharge opening 31, (b) temporarily stores the developer discharged from the toner bottle discharge opening 31, and (c) corresponds to an inner side of a toner supply section outer wall 3a, (ii) a supply section discharge opening 5 from which the toner is discharged, and (iii) a carrying member 9 that carries the toner from the temporary storing section to the supply section discharge opening 5. The toner supply section 3 surrounds an entire peripheral surface of a part of the toner bottle 2, including the toner bottle discharge opening 31, and supports the toner bottle 2 such that the toner bottle 2 can rotate around the shaft line (center shaft) L1.
The rotation of the toner bottle 2 causes the toner contained in the toner containing section 21 to be discharged from the toner bottle discharge opening 31 to the toner supply section 3. Thereafter, the toner is discharged from the toner supply section 3 to outside of the toner cartridge 1, through the supply section discharge opening 5.
As shown in
A stirring pedestal 2b, cylindrically projecting, which includes a driving connection depression 2a is provided in an edge part (front edge part) of the toner bottle 2 which edge part is located downstream of a direction in which toner is carried along the shaft line L1. As shown in
As shown in
Note that, according to a conventional toner cartridge 101, a toner bottle discharge opening 30 is formed in a surface of an edge part of a toner bottle 20, which surface is parallel to a surface perpendicular to a rotary shaft (shaft line L1) of the toner bottle 20 (see
In contrast, according to the toner cartridge 1 of the preset embodiment, the toner bottle discharge opening 31 is formed as described above. The inclined surface 31a makes it easy to stir and flow toner located in the vicinity of the first discharge opening upon rotation of the toner bottle 2 around the shaft line L1, in a case where the toner bottle 2 contains plenty of toner. The inclined surface 31a also makes it possible to discharge plenty of toner from the toner bottle 2 through the toner bottle discharge opening 31 formed in the inclined surface 31a. According to the configuration of the present embodiment, it is possible to stably discharge a certain large amount of toner, as compared with the conventional toner cartridge 101 in which the toner bottle discharge opening 30 is formed in the surface parallel to the surface perpendicular to the shaft line L1 of the toner bottle 20.
A decrease in amount of toner contained in the tone bottle 2 (i) makes it easy to stir the toner contained in the toner bottle 2 in response to the rotation of the toner bottle 2 and (ii) causes a decrease in time period during which the toner discharge opening 31 is closed by the toner contained in the toner bottle 2. This allows the outside air to easily flow into the toner bottle 2. Hence, plenty of toner can be continuously discharged.
It is thus possible that the toner cartridge 1 of the present embodiment stably discharges a certain large amount of toner from the toner cartridge 1, regardless of quantity of the toner contained in the toner containing section 21. Further, the toner cartridge 1 includes the toner supply section 3 which is configured to surround the periphery of the toner discharge opening 31. This makes it possible to prevent an image forming apparatus from upsizing and cost rise.
It is preferable to configure the toner cartridge 1 of the present embodiment such that the angle θ of the inclined surface 31a fall within a range from 20° to 60°. The angle θ, which falls within the range from 20° to 60°, makes it possible to properly and stably discharge a certain large amount of toner from the toner bottle discharge opening 30.
It is preferable that the angle θ of the inclined surface 31a increase as the image forming apparatus 100 operates at higher speed.
As shown in
As shown in
The following effect is brought about by the toner discharge position regulatory partition 6 having the cutout 6b. Toner is easily discharged in the gravitational direction from the toner discharge opening 31 formed in the inclined surface 31a, when the toner discharge opening 31, formed in the inclined surface 31a, (i) reaches, in response to the rotation of the toner bottle 2, around a lower side in the direction in which the toner bottle 2 is placed and then (ii) passes through the cutout 6b. The toner is discharged from the toner discharge opening 31 through the cutout 6b toward the toner supply section 3. Meanwhile, when the toner discharge opening 31 reaches, in response to the rotation of the toner bottle 2, around an upper side in the direction in which the toner bottle 2 is placed, outside air easily flows into the toner bottle 2 through an interspace between (a) the toner discharge opening 31 formed in the inclined surface 31a and (b) the surface 6b of the toner discharge position regulatory partition 6, which surface 6b is parallel to the surface perpendicular to the shaft line L1. Therefore, plenty of toner can be discharged from the toner bottle 2.
Note that the present embodiment describes an example in which the toner cartridge 1 of the present invention is applied to the image forming apparatus 100 shown in
An experiment was carried out. In the experiment, a relationship between quantity of toner left in a toner bottle and quantity of toner discharged from a toner cartridge was analyzed by use of (i) the toner cartridge 1 of the present embodiment in which the angle θ of the inclined surface 31a of the toner bottle 2 was 40° (Example) and (ii) the conventional toner cartridge 101 (Comparative Example) shown in
Note that the discharge openings of the toner bottles of Example and Comparative Example had an identical surface area. Further, toner contained in the toner bottle of Example was identical in quantity to that of Comparative Example.
Table 1 and
A developer container of the present invention is a developer container, including: a developer vessel, having a cylindrical shape, that carries and discharges developer contained therein through its first discharge opening while the developer vessel is being driven to rotate around a shaft line; and developer supply section including (i) a temporary storing section which surrounds a periphery of the first discharge opening and temporarily stores the developer discharged from the first discharge opening, (ii) a second discharge opening from which the developer is discharged outside of the developer supply section, and (iii) a carrying section that carries the developer from the temporary storing section toward the second discharge opening, said developer supply section supporting the developer vessel such that the developer vessel can rotate around the shaft line, the developer contained in the developer vessel being discharged outside of the developer container through the first discharge opening and the second discharge opening, and the first discharge opening being formed in an inclined surface of an edge part of the developer vessel, the inclined surface inclining, upstream of a direction in which the developer is carried along the shaft line, so as to be at angles with a surface perpendicular to the shaft line.
According to the configuration, it is possible to stably discharge a certain large amount of developer from the developer container regardless of quantity of the developer contained in the developer vessel.
It is preferable to further configure the developer container of the resent invention such that the developer supply section include a discharge quantity regulatory section which (i) covers the first discharge opening and (ii) has a surface parallel to the surface perpendicular to the shaft line, in which surface an opening is formed, through which opening the developer is put through to the temporary storing section from the developer vessel when the first discharge opening reaches, in response to the rotation of the developing vessel, around a lower side in a direction in which the developing vessel is placed.
According to the configuration, the discharge quantity regulatory section makes it easy to discharge the developer in the gravitational direction from the first discharge opening formed in the inclined surface, when the first discharge opening, formed in the inclined surface, (i) reaches, in response to the rotation of the developer vessel, around the lower side in the direction in which the developer vessel is placed, and then (ii) passes through the opening. The developer is discharged from the first discharge opening through the opening toward the developer supply section. Meanwhile, when the first discharge opening reaches, in response to the rotation of the developer vessel, around an upper side in the direction in which the developer vessel is placed, outside air easily flows into the developer vessel through an interspace between the first discharge opening formed in the inclined surface and the surface of the discharge quantity regulatory section, which surface is parallel to the surface perpendicular to the shaft line. Therefore, plenty of developer can be discharged from the developer vessel.
It is preferable to further configure the developer container of the present invention such that the inclined surface incline, upstream of the direction in which the developer is carried along the shaft line, so as to be at angle of 20° to 60° with the surface perpendicular to the shaft line.
According to the configuration, the inclined surface that inclines from 20° to 60° makes it possible to properly and stably discharge a certain large amount of developer from the first discharge opening.
It is preferable to configure the developer container of the present invention such that the developer vessel have an inner surface on which a plurality of convexities that project inward the developer vessel are in an intermittently spiral manner.
According to the configuration, the developer vessel has the inner surface on which the plurality of convexities that project inward the developer vessel are in the intermittently spiral manner. This causes the developer vessel to rotate around the shaft line. As such, the developer contained in the developer vessel is carried to the first discharge opening while being properly stirred by the plurality of convexities.
In order to attain the object, an image forming apparatus of the present invention is an image forming apparatus, from which the above-described developer container is detachable.
According to the configuration, the above-described developer container is detachable from the image forming apparatus of the present invention. Therefore, it is possible to always supply a moderate amount of developer to the developer container so as to develop an image. Appropriate supply of the developer allows image forming with an appropriate image quality. It is also possible to prevent an image forming apparatus from upsizing and cost rise.
Note that the developer container includes the developer supply section. Therefore, the developer container can be applied to an image forming apparatus that includes no developer supply device between a developer container and a developing device.
The present invention is not limited to the description of the embodiments above, and can therefore be modified by a skilled person in the art within the scope of the claims. Namely, an embodiment derived from a proper combination of technical means disclosed in different embodiments is encompassed in the technical scope of the present invention.
The present invention is applicable to a toner cartridge for use in an electrophotographic image forming apparatus such as a printer, a copying machine, a facsimile, or a multifunction peripheral (MFP: Multi Function Printer).
Number | Date | Country | Kind |
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2011-005119 | Jan 2011 | JP | national |