Stirring device, and image forming apparatus

Abstract

To provide a stirring device that can disperse lumps of developer stored in a container, and an image forming apparatus.SOLUTION: A stirring device 3 comprises a stirring body 31, a driving source 32, and a transmission mechanism 4. The stirring body 31 stirs developer T stored in a container 2. The driving source 32 drives to rotate the stirring body 31. The transmission mechanism 4 transmits a rotary force of the driving source 32 to the stirring body 31. When the magnitude of a resistance force against the rotation of the stirring body 31 becomes equal to or more than a certain value, the transmission mechanism 4 strikes a blow to the stirring body 31 toward a direction in which the stirring body 31 rotates.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an agitating device and an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art There are image forming apparatuses that form images on documents using toner. In such image forming apparatuses, the toner is stored in a toner container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-175984 A [Patent Document 2] JP 2012-198360 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the toner contained in the toner container has a tendency to gather in one biased position in the toner container and form clumps. The clumped toner may make it impossible to form an image on the document. In order to stably form an image on the document, the image forming apparatus of Patent Document 1 and the toner conveying device of Patent Document 2 agitate the toner in the toner container. However, even with the image forming apparatus of Patent Document 1 and the toner conveying device of Patent Document 2, there are cases where the toner clumps in the toner container cannot be dispersed.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide an agitator capable of dispersing lumps of developer contained in a container, and an image forming apparatus. [Means for solving the problem]

[0006] According to one aspect of the present invention, an agitator includes an agitator, a drive source, and a transmission mechanism. The agitator agitates developer contained in a container. The drive source drives the agitator to rotate. The transmission mechanism transmits the rotational force of the drive source to the agitator. When the magnitude of the resistance force against the rotation of the agitator reaches or exceeds a certain level, the transmission mechanism applies an impact to the agitator in the direction in which the agitator rotates.

[0007] According to another aspect of the present invention, an image forming apparatus includes an image forming unit, a container, and the stirring device. The image forming apparatus forms an image on a recording medium with a developer. The container contains the developer. The stirring device stirs the developer contained in the container. Effect of the Invention

[0008] According to the stirring device and image forming apparatus of the present invention, it is possible to disperse lumps of developer contained in a container. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to an embodiment. [Diagram 2] FIG. 2 is a side view of the stirring device according to the embodiment. [Diagram 3] 3 is a perspective view of the transmission mechanism shown in FIG. 2, showing a state in which a transmission body is detached from a rotating shaft. FIG. [Figure 4] FIG. 3 is an enlarged view of part A in FIG. 2. [Diagram 5] FIG. 5 is a diagram showing the state before the hammer strikes the transmission body in FIG. 4. [Figure 6] FIG. 5 is a diagram showing a state in which the hammer strikes the transmission body in FIG. 4. [Figure 7] FIG. 7 is a perspective view showing a cross section BB of FIG. [Figure 8] FIG. 5 is a diagram showing a state after the hammer strikes the transmission body in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0011] An overview of an image forming apparatus 100 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram of the image forming apparatus 100 according to an embodiment.

[0012] The image forming apparatus 100 is an apparatus having a function of forming an image on a recording medium S by an electrophotographic method or an inkjet method. The image forming apparatus 100 may be, for example, a printer, a copier, or an MFP (Multi Function Printer). The image forming apparatus 100 shown in FIG. 1 is an example of an electrophotographic printer.

[0013] As shown in FIG. 1, the image forming apparatus 100 includes an image forming section 1, a container 2, and an agitator 3.

[0014] The image forming unit 1 forms an image on a recording medium S with a developer T. The developer T is a colorant such as toner or ink. The recording medium S is plain paper, recycled paper, thin paper, thick paper, coated paper, or an OHP (Overhead Projector) sheet. The image forming unit 1 illustrated in FIG. 1 forms an image on the recording medium S using a toner.

[0015] The container 2 contains developer T. The image forming unit 1 shown in FIG. 1 has a plurality of containers 2. Each container 2 contains toner of a plurality of colors (e.g., Y (yellow), M (magenta), C (cyan), and K (black)). Each container 2 supplies the contained toner to the image forming unit 1.

[0016] The agitator 3 agitates the developer T contained in the container 2. Therefore, the developer T that has become lumpy in the container 2 is dispersed by the agitator 3.

[0017] The structure of the agitator 3 according to the embodiment will be described with reference to Fig. 2 to Fig. 4. Fig. 2 is a side view of the agitator 3 according to the embodiment. Fig. 3 is a perspective view of the transmission mechanism 4 shown in Fig. 2, showing a state in which the transmission body 41 is removed from the rotating shaft 322. Fig. 4 is an enlarged view of part A in Fig. 2.

[0018] As shown in FIG. 2, the stirring device 3 includes a stirring body 31, a driving source 32, and a transmission mechanism 4.

[0019] The agitator 31 agitates the developer T contained in the container 2. Therefore, the developer T that has become lumpy in the container 2 is dispersed by the agitator 31.

[0020] 2 is a screw inserted into the container 2. The stirrer 31 has a main body 31A and a rotated end portion 31B.

[0021] The main body 31A is accommodated in the container 2. The main body 31A is a portion of the screw where the blades are provided. The developer T accommodated in the container 2 is stirred by the rotation of the main body 31A. This disperses any clumps of the developer T accommodated in the container 2. Note that the main body 31A is not limited to the screw exemplified in FIG. 2 as long as it can stir the developer T accommodated in the container 2.

[0022] The rotated end 31B is exposed to the outside of the container 2. The rotated end 31B is a portion to which a rotational force is applied to the main body 31A. The rotated end 31B has a transmission element 311. The transmission element 311 transmits the rotational force to the screw. The transmission element 311 shown in FIG. 2 is a gear train composed of two gears. Note that the rotated end 31B does not necessarily require the transmission element 311 as long as a rotational force can be applied to it.

[0023] The driving source 32 drives and rotates the agitator 31. The driving source 32 has a motor (not shown), a driven gear 321, and a rotating shaft 322.

[0024] The motor generates a rotational force. Note that the driving source 32 may have a device other than a motor as a device that generates a rotational force.

[0025] The driven gear 321 is a gear that rotates by the torque of the motor. The driven gear 321 transmits the torque of the motor to a rotating shaft 322, which will be described later. Therefore, the driving source 32 may have elements other than the driven gear 321 as long as the torque of the motor can be transmitted to the rotating shaft 322.

[0026] The rotating shaft 322 rotates together with the driven gear 321. The rotating shaft 322 protrudes from the driven gear 321 along the rotation center of the driven gear 321. The rotational force generated by the motor is transmitted through the rotating shaft 322.

[0027] 3, the rotating shaft 322 has a groove 323. The groove 323 is provided in the rotating shaft 322 along the axial direction of the rotating shaft 322.

[0028] 4 transmits the rotational force of the drive source 32 to the agitator 31. The agitator 31 rotates as the rotational force of the drive source 32 is transmitted by the transmission mechanism 4. As a result, the developer T contained in the container 2 is agitated by the agitator 31.

[0029] If lumps of developer T are formed inside the container 2, the agitator 31 receives resistance to rotation from the lumps of developer T in the process of dispersing the lumps of developer T. The magnitude of the resistance force against the rotation of the agitator 31 increases as the developer T becomes more firmly condensed. Therefore, the agitator 31 is rotated so that the resistance force caused by the rotation of the agitator 31 does not exceed the strength of the agitator 31. Hereinafter, the resistance force against the rotation of the agitator 31 may be referred to as the resistance force.

[0030] When the resistance force reaches a certain level or more, the transmission mechanism 4 applies an impact to the agitator 31 in the direction in which the agitator 31 rotates. A resistance force of a certain level is a resistance force that does not exceed the strength of the agitator 31. Therefore, an impact load of a level that does not damage the agitator 31 is applied. The impact load applied to the agitator 31 is transmitted to the developer T. As a result, the agitator 31 can disperse clumps of the developer T that could not be dispersed by a steady rotational force of a certain level or less.

[0031] The transmission mechanism 4 has a transmission body 41 , a hammer 42 , and a pressing body 43 .

[0032] The transmission body 41 can transmit a rotational force to the agitator 31. The transmission body 41 has a base 411 that transmits the rotational force. The base 411 has a gear shape. The transmission element 311 of the agitator 31 meshes with the base 411. When the base 411 rotates, the screw rotates via the transmission element 311 of the agitator 31.

[0033] The hammer 42 transmits a rotational force of less than a certain magnitude by the rotating shaft 322 to the transmission body 41. The hammer 42 also applies an impact to the transmission body 41 by the rotational force of the rotating shaft 322. As shown in Fig. 3, the hammer 42 has a cylindrical shape. The hammer 42 has a protrusion 421 that protrudes toward the hollow portion of the hammer 42.

[0034] The rotating shaft 322 is inserted into the hollow portion of the hammer 42 so that the protruding portion 421 fits into the groove 323. With the protruding portion 421 fitting into the groove 323, the hammer 42 is constrained to the rotating shaft 322 with respect to the rotation direction of the rotating shaft 322. Therefore, the hammer 42 rotates together with the rotating shaft 322. The hammer 42, which rotates together with the rotating shaft 322, comes into contact with the transmission body 41 for a certain period of time, whereby a rotational force is transmitted from the hammer 42 to the transmission body 41. On the other hand, the hammer 42, which rotates together with the rotating shaft 322, comes into instantaneous contact with the transmission body 41, whereby the transmission body 41 is struck by the hammer 42.

[0035] Hammer 42 slides between a transmission position and an impact position. At the transmission position, a rotational force of less than a certain magnitude is transmitted by rotating shaft 322 to transmission body 41. At the impact position, an impact is applied to transmission body 41 by the rotational force of rotating shaft 322. Therefore, hammer 42 in the transmission position can both transmit a rotational force of less than a certain magnitude to transmission body 41 and transmit an impact load to transmission body 41. As a result, the mixing device 3 can be made smaller since it is not necessary to transmit the two types of loads using separate parts.

[0036] Preferably, the hammer 42 shown in FIG. 4 slides along the rotation shaft 322. Specifically, the hammer 42 is disposed between the transmission body 41 and the driven gear 321. The hammer 42 can slide along the rotation shaft 322 by guiding the protruding portion 421 (see FIG. 3) in the groove 323 (see FIG. 3). In this way, the transmission body 41 and the hammer 42 can be disposed along the rotation shaft 322. Therefore, since there is no need to adopt a complicated transmission structure, the structure of the stirring device 3 becomes simple. Supplementally, the transmission position and the striking position are disposed between the transmission body 41 and the driven gear 321 and are disposed at positions along the axis of the rotation shaft 322. In FIG. 4, the hammer 42 disposed at the transmission position is shown by a solid line. Also, in FIG. 4, the hammer 42 disposed at the striking position is shown by a virtual line.

[0037] The pressing body 43 presses the hammer 42 from the striking position toward the transmission position. Therefore, even if the user does not operate the position of the hammer 42, the hammer 42 automatically returns from the striking position to the transmission position.

[0038] Preferably, the pressing body 43 is a coil spring into which the rotating shaft 322 fits. In this way, there is no need to consume power such as electricity.

[0039] The detailed structures of the transmission body 41 and the hammer 42, and the operation of the hammer 42 will be described with reference to Figs. 5 to 8. Fig. 5 is a diagram showing a state before the hammer 42 strikes the transmission body 41 in Fig. 4. Fig. 6 is a diagram showing a state in which the hammer 42 strikes the transmission body 41 in Fig. 4. Fig. 7 is a perspective view showing a BB cross section in Fig. 6. Fig. 8 is a diagram showing a state after the hammer 42 strikes the transmission body 41 in Fig. 4. In the following description, the structures of the transmission body 41 and the hammer 42 for the hammer 42 to transmit a rotational force to the transmission body 41 at the transmission position will be described in particular. The structures of the transmission body 41 and the hammer 42 for the hammer 42 to strike the transmission body 41 will also be described.

[0040] 5, the rotation center of the transmission body 41 overlaps with the rotation center of the hammer 42. By overlapping the rotation center of the transmission body 41 and the rotation center of the hammer 42, both the transmission body 41 and the hammer 42 can rotate simultaneously without causing swing that would make it impossible to transmit a rotational force. Note that the rotation center of the transmission body 41 and the rotation center of the hammer 42 do not need to strictly overlap, and it is sufficient that large swing is not caused when the transmission body 41 and the hammer 42 rotate simultaneously.

[0041] The transmitting body 41 further has a hammer facing surface 412, a force receiving surface 413, and a struck portion 414. The hammer facing surface 412 is a surface that faces the hammer 42. The force receiving surface 413 is a surface to which a rotational force of less than a certain magnitude is transmitted from the hammer 42. In detail, the force receiving surface 413 is a surface that rises in a spiral shape from the hammer facing surface 412 toward the rotational direction of the transmitting body 41.

[0042] The struck portion 414 protrudes toward the center of rotation of the transmission body 41. The struck portion 414 is provided at the tip of a pillar extending from the transmission body 41 toward the driving source 32.

[0043] The hammer 42 further has a transmitting body facing surface 422, a transmitting surface 423, and a striking portion 424. The transmitting body facing surface 422 is a surface that faces the transmitting body 41. The transmitting surface 423 is a surface that transmits the rotational force of the rotating shaft 322 to the transmitted surface 413. In detail, the transmitting surface 423 is a surface that rises in a spiral shape from the transmitting body facing surface 422 in the opposite direction to the rotation direction of the hammer 42 so as to come into contact with the transmitted surface 413 when the hammer 42 is in the transmitting position.

[0044] 5, when the hammer 42 is in the transmitting position, it rotates together with the rotating shaft 322. Since the pressing body 43 presses the hammer 42 toward the spring, the transmitting surface 423 is in contact with the forced surface 413. As a result, the rotational force of the rotating shaft 322 is transmitted to the stirrer 31 via the forced surface 413.

[0045] As shown in FIG. 6, when the resistance force against the rotation of the stirrer 31 reaches a certain level or more, the rotational force transmitted from the transmitting surface 423 to the force-receiving surface 413 becomes larger than the frictional force generated between the transmitting surface 423 and the force-receiving surface 413. Therefore, the transmitting surface 423 slides relative to the force-receiving surface 413 in a direction along the rotational direction of the rotating shaft 322. As a result, the hammer 42 moves against the pressing force of the pressing body 43. Then, the transmitting surface 423 and the force-receiving surface 413 are separated from each other, so that the rotational force of the rotating shaft 322 is no longer transmitted to the stirrer 31. In other words, a simple structure of a spiral inclined surface can prevent a rotational force of a certain level or more from being applied to the stirrer 31.

[0046] When the hammer 42 is in the striking position, the striking portion 424 protrudes in the opposite direction to the transmitting body 41 so as to strike the struck portion 414. The striking portion 424 shown in Fig. 6 protrudes in the rotation direction of the hammer 42 so as to strike the struck portion 414 in a state in which the transmitting surface 423 is separated from the forced surface 413.

[0047] 6 and 7, when the hammer 42 is placed in the striking position, the striking portion 424 strikes the struck portion 414. As a result, the strike caused by the rotational force of the rotating shaft 322 is transmitted to the stirrer 31 via the struck portion 414.

[0048] As shown in Fig. 8, after the striking portion 424 strikes the struck portion 414, the hammer 42 slides to the transmitting position due to the pressing force of the pressing body 43. Here, since no rotational force is transmitted from the driving source 32 to the transmitting body 41, the rotational speed of the hammer 42 is faster than the rotational speed of the transmitting body 41. Therefore, the transmitting surface 423 of the hammer 42 that has slid to the transmitting position comes into contact with the transmitted surface 413 of the transmitting body 41 over time, as shown in Fig. 5. As a result, the rotational force of the driving source 32 is transmitted to the transmitting body 41 again.

[0049] Preferably, the transmission body 41 has two struck parts 414. The two struck parts 414 are disposed at positions on either side of the rotation center of the transmission body 41.

[0050] The hammer 42 has two striking parts 424. The two striking parts 424 are disposed at positions sandwiching the center of rotation of the hammer 42. In this manner, the load caused by the strike is distributed to the two striking parts 424 and the two struck parts 414. As a result, the durability of the hammer 42 and the transmission body 41 is improved.

[0051] 3, the transmitting body 41 preferably has two force-receiving surfaces 413. The two force-receiving surfaces 413 are disposed at positions on either side of the rotation center of the transmitting body 41.

[0052] The hammer 42 has two transmission surfaces 423. The two transmission surfaces 423 are disposed at positions sandwiching the rotation center of the hammer 42. In this way, the load transmitted from the transmission surface 423 to the force-receiving surface 413 is distributed to the two transmission surfaces 423 and the two force-receiving surfaces 413. As a result, the durability of the hammer 42 and the transmission body 41 is improved.

[0053] As shown in FIG. 1, an image forming apparatus 100 including an agitator 3 can agitate developer T by a rotational force accompanied by an impact load, and therefore can stably form an image on a document.

[0054] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the spirit of the present invention. The drawings are mainly schematic illustrations of each component for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings are different from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are merely examples and are not particularly limited, and various modifications are possible within a range that does not substantially deviate from the configuration of the present invention. [Industrial Applicability]

[0055] The present invention provides an agitating device and an image forming apparatus, and has industrial applicability. [Explanation of symbols]

[0056] 1: Image forming section 2: Container 3: Stirring device 4: Transmission mechanism 31: Stirring body 32: Driving source 41: Transmission body 42: Hammer 43: Pressing body 412: Hammer facing surface 413: Receiving surface 414: Hit part 422: Transmission body facing surface 423: Transmission surface 424: Striking section

Claims

1. an agitator for agitating the developer contained in the container; A drive source that rotates the stirring body; a transmission mechanism that transmits a rotational force of the drive source to the stirring body, The transmission mechanism applies an impact to the agitator in the direction in which the agitator rotates when the resistance force against the rotation of the agitator reaches a certain level or greater.

2. The drive source has a rotating shaft, The transmission mechanism includes: A transmission body capable of transmitting a rotational force to the stirring body; a hammer that transmits a rotational force of less than a certain magnitude from the rotating shaft to the transmission body, or applies a strike to the transmission body by the rotational force of the rotating shaft, The stirring device according to claim 1, wherein the hammer slides between a transmission position where the rotational force of the rotating shaft, which is less than a certain magnitude, is transmitted to the transmission body, and an impact position where an impact caused by the rotational force of the rotating shaft is applied to the transmission body.

3. The stirring device according to claim 2 , wherein the hammer slides along the axis of rotation.

4. The transmission mechanism includes: The stirring device according to claim 3 , further comprising a pressing body that presses the hammer from the striking position toward the transmitting position.

5. The rotation center of the transmission body overlaps with the rotation center of the hammer, The transmitter is a hammer facing surface facing the hammer; A rotational force smaller than a certain value is transmitted from the hammer to a transmission surface, the driven surface is a surface that rises in a spiral shape from the hammer facing surface toward the rotation direction of the transmission body, The hammer is a transmission body facing surface facing the transmission body; a transmission surface that transmits a rotational force of the rotation shaft to the transmitted surface, 5. The stirring device according to claim 4, wherein the transmission surface is a surface that rises in a spiral shape from the transmission body opposing surface in a direction opposite to the rotation direction of the hammer so as to contact the transmitted surface when the hammer is in the transmitting position.

6. The transmission body further includes a striking portion protruding toward a rotation center of the transmission body, The stirring device according to claim 5 , wherein the hammer further comprises a striking portion that projects in a direction opposite to the transmitting body so as to strike the struck portion when the hammer is in the striking position.

7. The transmission body has two of the struck portions, The two struck parts are disposed at positions on either side of the rotation center of the transmission body, The hammer has two striking parts, The stirring device according to claim 6 , wherein the two striking parts are disposed at positions sandwiching a rotation center of the hammer.

8. an image forming section for forming an image on a recording medium with the developer; a container for containing the developer; An image forming apparatus comprising: the stirring device according to claim 1 , which stirs the developer contained in the container.

Images