Image forming apparatus, control method, and program

Abstract

To prevent vibration sound generated when vibration is applied to a toner bottle to reduce discomfort caused to nearby people.SOLUTION: An image forming apparatus 1 to which a toner bottle 40 is removably attached comprises: a driving source 50 that rotates the toner bottle 40; a vibration application unit 55 that applies vibration to the toner bottle 40 along with the rotation of the toner bottle 40; a remaining amount detection unit 64 that detects the amount of toner remaining inside the toner bottle 40; and a control unit 7 that, based on a result of detection performed by the remaining amount detection unit 64, changes the impact of vibration applied by the vibration application unit 55 to the toner bottle 40 during the rotation of the toner bottle 40.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, a control method, and a program, and particularly relates to a control technology for supplying toner from a toner bottle. [Background Art]

[0002] In an electrophotographic image forming apparatus such as a printer or an MFP (Multifunction Peripheral), a toner bottle containing toner is detachably attachable, and the toner filled inside the bottle is supplied to a developing device by rotating the toner bottle attached to the apparatus main body. In this type of image forming apparatus, toner may aggregate and adhere to the inner wall of the toner bottle. In such a case, simply rotating the toner bottle cannot separate the toner from the inner wall, resulting in that a toner empty condition is detected while toner still remains inside the bottle.

[0003] Conventionally, in order to allow toner to be discharged without leaving any residue inside the toner bottle, an image forming apparatus has been proposed in which a protrusion is provided on the outer peripheral surface of the toner bottle, and an abutment portion is provided at a position through which the protrusion passes while the toner bottle rotates (for example, Patent Document 1). In this prior art, as the toner bottle rotates, the protrusion falls after climbing over the abutment portion, thereby applying vibration to the toner bottle, and is configured to separate the toner adhering to the inner wall of the toner bottle from the inner wall. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Laid-Open No. 2003-241492 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] Incidentally, the conventional image forming apparatus described above generates a vibration noise when the toner bottle is vibrated and dropped. This vibration noise is not very loud when there is a lot of toner remaining in the bottle, so it is not enough to cause discomfort to people nearby. However, as the amount of toner remaining in the bottle decreases, the vibration noise gradually gets louder and is transmitted as noise around the apparatus, which is a problem as it can cause discomfort to people nearby.

[0006] The present invention was made to solve the above-mentioned conventional problems, and aims to provide an image forming apparatus, control method, and program that can suppress the vibration noise generated when vibration is applied to the toner bottle, thereby reducing the discomfort caused to those nearby. [Means for solving the problem]

[0007] To achieve the above objective, the invention according to claim 1 is an image forming apparatus capable of mounting a toner bottle, comprising: a drive source for rotating the toner bottle; a vibration applying unit for applying vibration to the toner bottle as the toner bottle rotates; a remaining amount detection unit for detecting the remaining amount of toner inside the toner bottle; and a control unit that, based on the detection result of the remaining amount detection unit, changes the impact of the vibration applied to the toner bottle by the vibration applying unit while the toner bottle is rotating. When the remaining toner amount is detected by the remaining amount detection unit to be less than a predetermined amount, the control unit reduces the impact of vibrations applied to the toner bottle by the vibration application unit while the toner bottle is rotating. This configuration is characterized by the following features.

[0009] Claim 2 The invention relating to this invention is an image forming apparatus according to claim 1, characterized in that the control unit changes the torque when the drive source rotates the toner bottle based on the detection result of the remaining amount detection unit.

[0010] Claim 3 The invention relating to this invention is an image forming apparatus according to claim 3, characterized in that the control unit changes the torque when the drive source rotates the toner bottle by changing the current supplied to the drive source.

[0011] Claim 4 The invention relating to this claim is 1 In an image forming apparatus, the control unit determines the remaining toner amount based on the remaining amount detection unit. The aforementioned The configuration is characterized in that, when it is detected that the amount of toner is greater than a predetermined amount, the drive source is driven with a first current, and when the remaining amount detection unit detects that the remaining amount of toner is less than the predetermined amount, the drive source is driven with a second current smaller than the first current.

[0012] Claim 5 The invention relating to this claim is 4 In the image forming apparatus, the control unit detects the rotational position of the toner bottle by the drive source, and when the remaining amount detection unit detects that the remaining amount of toner is less than a predetermined amount, it changes the current supplied to the drive source from the first current to the second current before the rotational position of the toner bottle passes the position where vibration is applied to the toner bottle by the vibration application unit.

[0013] Claim 6 The invention relating to this claim is 4 The image forming apparatus further includes an environmental sensor for detecting temperature and humidity, and the control unit is characterized in that, when the remaining amount detection unit detects that the remaining amount of toner is less than a predetermined amount, and the temperature detected by the environmental sensor is lower than a predetermined temperature and the humidity is lower than a predetermined humidity, it drives the drive source with a third current that is smaller than the first current and larger than the second current.

[0014] Claim 7 The invention relating to this claim is 4The image forming apparatus further includes a toner adhesion detection unit for detecting toner adhering to the inner wall of the toner bottle, and the control unit is characterized in that, when the remaining amount detection unit detects that the remaining amount of toner is less than a predetermined amount, and the toner adhesion detection unit detects that toner is adhering to the inner wall of the toner bottle, it drives the drive source with a third current that is smaller than the first current and larger than the second current.

[0015] Claim 8 The invention relating to this claim is 7 In the image forming apparatus, the toner adhesion detection unit is composed of line sensors arranged along the longitudinal direction of the toner bottle, and is characterized by detecting toner adhering to the inner wall in the longitudinal direction of the toner bottle by detecting the reflected light of light irradiated onto the outer surface of the toner bottle.

[0016] Claim 9 The invention relating to claim 1 is an image forming apparatus characterized in that the remaining amount detection unit has a sound detection unit that detects the sound produced when vibration is applied to the toner bottle by the vibration application unit, and detects the remaining amount of toner based on the sound level detected by the sound detection unit.

[0017] Claim 10 The invention relating to this invention is an image forming apparatus according to claim 1, wherein the remaining amount detection unit has a vibration detection unit that detects vibration when vibration is applied to the toner bottle by the vibration application unit, and the remaining amount of toner is detected based on the level of vibration detected by the vibration detection unit.

[0018] Claim 11 The invention relating to this invention is an image forming apparatus according to claim 1, characterized in that the remaining amount detection unit detects the remaining amount of toner based on the current flowing to the drive source when the drive source is started to operate.

[0019] Claim 12The invention according to [claim] is the image forming apparatus according to claim 1, characterized in that the control section changes a rotation speed at which the drive source rotates the toner bottle based on a detection result of the remaining amount detection section.

[0020] Claim 13 The invention according to [claim] is the image forming apparatus according to claim 12 , characterized in that the control section changes the rotation speed at which the drive source rotates the toner bottle by changing a period of a current waveform supplied to the drive source.

[0021] Claim 14 The invention according to [claim] is the image forming apparatus according to claim 13 , wherein the control section determines that the remaining amount of toner detected by the remaining amount detection section is The aforementioned detected as being greater than a predetermined amount, drives the drive source at a first rotation speed; and when the remaining amount detection section detects that the remaining amount of toner is less than the predetermined amount, drives the drive source at a second rotation speed that is slower than the first rotation speed, which is a characteristic configuration.

[0022] Claim 15 The invention according to [claim] is the image forming apparatus according to claim 14 , wherein the control section detects a rotation position of the toner bottle by the drive source, and when the remaining amount detection section detects that the remaining amount of toner is less than the predetermined amount, changes the rotation speed from the first rotation speed to the second rotation speed before the rotation position of the toner bottle passes through a position where vibration is applied to the toner bottle by the vibration applying section, which is a characteristic configuration.

[0023] Claim 16 The invention according to [claim] is the image forming apparatus according to claim 1, further comprising a person detection section that detects a person around the apparatus, wherein when no person is detected by the person detection section, regardless of the detection result of the remaining amount detection section, the control section does not change the impact of vibration applied to the toner bottle by the vibration applying section during rotation of the toner bottle; and when a person is detected by the person detection section, When the remaining toner level is detected by the remaining toner level detection unit to be less than a predetermined amount, the vibration applied to the toner bottle by the vibration application unit during the rotation of the toner bottle is reduced. This configuration is characterized by the following features.

[0024] Claim 17 The invention relating to this invention is an image forming apparatus according to claim 1, wherein the vibration-applying unit has a convex portion provided on the outer circumferential surface of the toner bottle and a recess provided on a support portion that supports the outer circumferential surface of the toner bottle, and is characterized in that vibration is applied to the toner bottle when the convex portion fits into the recess due to the rotation of the toner bottle.

[0025] Claim 18 The invention relating to this invention is an image forming apparatus according to claim 1, wherein the vibration-applying unit has a recess provided on the outer circumferential surface of the toner bottle and a protrusion provided on a support unit that supports the outer circumferential surface of the toner bottle, and the vibration is applied to the toner bottle when the protrusion fits into the recess due to the rotation of the toner bottle.

[0026] The invention according to claim 20 is a control method for an image forming apparatus, comprising: a drive source capable of mounting a toner bottle, for rotating the toner bottle, and a vibration applying unit that applies vibration to the toner bottle as the toner bottle rotates, the method comprising: a remaining amount detection step for detecting the remaining amount of toner inside the toner bottle; and a control step for changing the impact of vibration applied to the toner bottle by the vibration applying unit during rotation of the toner bottle based on the detection result of the remaining amount detection step. Furthermore, if the control step detects that the remaining toner amount is less than a predetermined amount by the remaining amount detection step, the vibration impact applied to the toner bottle by the vibration applying unit during the rotation of the toner bottle is reduced. This configuration is characterized by the following features.

[0027] The invention according to claim 21 is a program to be executed in an image forming apparatus that can accommodate a toner bottle and comprises a drive source for rotating the toner bottle and a vibration applying unit for applying vibration to the toner bottle as the toner bottle rotates, wherein the program causes the image forming apparatus to perform a remaining amount detection step for detecting the remaining amount of toner inside the toner bottle and a control step for changing the impact of the vibration applied to the toner bottle by the vibration applying unit while the toner bottle is rotating, based on the detection result of the remaining amount detection step. The control step, when the remaining amount detection step detects that the remaining amount of toner is less than a predetermined amount, reduces the impact of vibrations applied to the toner bottle by the vibration applying unit while the toner bottle is rotating. This configuration is characterized by the following features. [Effects of the Invention]

[0028] According to the present invention, vibration noise generated when vibration is applied to the toner bottle can be suppressed, thereby reducing discomfort to people around the image forming apparatus. [Brief explanation of the drawing]

[0029] [Figure 1] This figure shows an example of the external configuration of an image forming apparatus. [Figure 2] This is a diagram showing the internal structure of the printer unit. [Figure 3] This is a perspective view showing multiple toner bottles that are fitted into the bottle mounting section. [Figure 4] This figure shows the cross-sectional structure of the toner bottle and its support. [Figure 5] This diagram shows the state before and after the convex part of the vibration-applying component falls into the concave part. [Figure 6] This figure shows an example configuration in which a convex portion is formed on the support portion and a concave portion is formed on the bottle body. [Figure 7] This is a block diagram showing the configuration of the control unit that rotates the toner bottle. [Figure 8] This diagram shows the current supplied to the motor. [Figure 9] This is a flowchart showing the first processing procedure performed by the control unit. [Figure 10] This flowchart shows the second processing procedure performed by the control unit. [Figure 11] This flowchart shows the third processing step performed by the control unit. [Figure 12] This flowchart shows the fourth processing step performed by the control unit. [Figure 13] This is a block diagram showing an example of the configuration of the control unit in the second embodiment. [Figure 14] This flowchart shows the processing procedure performed by the control unit of the second embodiment. [Figure 15] This is a block diagram showing an example of the configuration of the control unit in the third embodiment. [Figure 16] This flowchart shows the processing procedure performed by the control unit of the third embodiment. [Figure 17] This diagram shows the current supplied to the motor. [Figure 18] This flowchart shows the processing procedure performed by the control unit of the fourth embodiment. [Figure 19] This flowchart shows the processing procedure performed by the control unit of the fifth embodiment. [Figure 20] This is a perspective view showing the bottle mounting section in the sixth embodiment. [Modes for carrying out the invention]

[0030] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the embodiments described below, elements common to all are denoted by the same reference numerals, and redundant explanations of these elements will be omitted.

[0031] (First Embodiment) Figure 1 shows an example of the external configuration of an image forming apparatus 1 in a first embodiment of the present invention. The XYZ three-dimensional coordinate system shown in Figure 1 is a coordinate system in which the XY plane is the horizontal plane and the Z direction is the vertical direction, and is a coordinate system common to the coordinate systems shown in other figures. As shown in Figure 1, the image forming apparatus is configured as an MFP equipped with multiple functions such as a copying function, a scanning function and a printing function.

[0032] The image forming apparatus 1 has a printer unit 2 in the center of the main body of the apparatus. The printer unit 2 has a paper feed cassette 3 at its bottom. The paper feed cassette 3 has a paper feed tray 10 (see Figure 2) inside, and a stack of sheets 8 such as printing paper can be stored in the paper feed tray 10 by pulling it out towards the front of the main body of the apparatus. The printer unit 2 performs electrophotographic image formation on the sheets 8 fed from the paper feed tray 10, transferring a toner image based on the image data to be printed onto the sheet 8, fixing the toner image onto the sheet 8, and then ejecting it to the output tray 4. A door member 2c is provided on the front side of the printer unit 2 that can be opened and closed when replacing the toner bottle 40 (see Figure 2) installed inside the apparatus.

[0033] The image forming apparatus 1 includes a scanner unit 5 and an operation panel 6 located above the printer unit 2. The scanner unit 5 optically reads the image of the original document set by the user and generates image data. For example, if the job specified by the user is a copy job, the scanner unit 5 reads the original document and generates image data, and the printer unit 2 performs image formation on the sheet 8 based on that image data. The operation panel 6 serves as the user interface for when the user operates the image forming apparatus 1. This operation panel 6 displays various screens to the user and accepts user operations.

[0034] Figure 2 shows the internal structure of the printer unit 2. The printer unit 2 contains a sheet transport mechanism 2a for transporting the sheet 8 and an image forming mechanism 2b. The printer unit 2 also contains a control unit 7 that comprehensively controls the operation of the sheet transport mechanism 2a and the image forming mechanism 2b.

[0035] The sheet transport mechanism 2a is a mechanism that takes one sheet 8 from the top of the stack of sheets 8 stored in the paper tray 10 and transports that sheet 8 along the transport path 11 shown by the dashed line in the figure in the direction of arrow F1. The sheet transport mechanism 2a sends one sheet 8 stored in the paper tray 10 to the transport path 11 using a pickup roller 12 and a paper feed roller 13. This transport path 11 is equipped with a timing roller 14, a secondary transfer roller 23, a fixing unit 28, and a paper discharge roller 15. The sheet 8 sent from the paper tray 10 to the transport path 11 stops briefly at the position of the timing roller 14, and is supplied from the timing roller 14 to the secondary transfer roller 23 in time with the timing of the toner image that has been primary transferred to the intermediate transfer belt 22 by the image forming mechanism 2b reaching the position of the secondary transfer roller 23. As a result, when the sheet 8 passes the position of the secondary transfer roller 23, the toner image that has been primary transferred to the intermediate transfer belt 22 is secondary transferred to the surface of the sheet 8. The sheet 8 on which the toner image has been transferred is then subjected to heat and pressure treatment as it passes through the fuser unit 28, fixing the toner image to its surface. The sheet 8 with the fixed toner image is then discharged from the paper output roller 15 onto the paper output tray 4 at the top of the printer unit 2.

[0036] The image forming mechanism 2b includes a drive roller 20, a driven roller 21, an intermediate transfer belt 22, a secondary transfer roller 23, and image forming units 30Y, 30M, 30C, 30K, each provided separately for the colors Y (yellow), M (magenta), C (cyan), and K (black), and primary transfer rollers 24Y, 24M, which are positioned opposite each image forming unit 30Y, 30M, 30C, 30K with the intermediate transfer belt 22 in between. The printer unit comprises 24C, 24K, toner bottles 40Y, 40M, 40C, 40K of each color (Y, M, C, K) that are detachable from the printer unit 2, a sub-hopper unit 36 ​​located below the toner bottles 40Y, 40M, 40C, 40K, and joints 38Y, 38M, 38C, 38K connected to the sub-hopper unit 36 ​​to supply toner to each of the image forming units 30Y, 30M, 30C, 30K.

[0037] The drive roller 20 is positioned opposite the secondary transfer roller 23 across the sheet 8 transport path 11 and is rotated in a predetermined direction (counterclockwise) by a motor (not shown). The driven roller 21 is positioned at approximately the same height as the drive roller 20 but at a distance from it. The intermediate transfer belt 22 is an endless belt stretched between the drive roller 20 and the driven roller 21. The driven roller 21 is biased away from the drive roller 20 (to the left in Figure 2) by a spring (not shown), applying tension to the intermediate transfer belt 22. As the drive roller 20 rotates in the predetermined direction, the intermediate transfer belt 22 moves in a circular motion in the direction of arrow F2 in the figure, and the driven roller also rotates in a driven motion.

[0038] Below the intermediate transfer belt 22, image forming units 30Y, 30M, 30C, and 30K for each color (Y, M, C, and K) are arranged at predetermined intervals. The image forming units 30Y, 30M, 30C, and 30K differ only in the color of toner they handle; their specific configurations and operations are common to each other. Therefore, in the following, when the individual image forming units 30Y, 30M, 30C, and 30K are not distinguished, they may be collectively referred to simply as "image forming unit 30".

[0039] The image forming unit 30 includes a photoreceptor drum 31 positioned opposite the primary transfer rollers 24Y, 24M, 24C, and 24K, with the intermediate transfer belt 22 in between. The photoreceptor drum 31 is an image carrier with a photosensitive layer formed on the surface of a cylindrical drum. A cleaner 35, a charger 32, an exposure unit 33, and a developer unit 34 are arranged around the photoreceptor drum 31. The cleaner 35 is for removing toner that remains on the surface of the photoreceptor drum 31 without being primary transferred to the intermediate transfer belt 22. The charger 32 charges the photosensitive layer on the surface of the photoreceptor drum 31 to a predetermined charge. The exposure unit 33 has a light source such as a semiconductor laser or a light-emitting diode, and forms an electrostatic latent image on the surface of the photoreceptor drum 31 by exposing the photosensitive layer, which has been charged to a predetermined charge, based on the image data to be drawn. The developing unit 34 is filled with a developer containing toner, and by applying the developer to the surface of the photoreceptor drum 31, it makes the electrostatic latent image formed by the exposure unit 33 visible with toner. As a result, a toner image is formed on the surface of the photoreceptor drum 31.

[0040] The toner image formed on the surface of the photoreceptor drum 31 is first transferred to the intermediate transfer belt 22 as the intermediate transfer belt 22 passes between the photoreceptor drum 31 and the primary transfer rollers 24Y, 24M, 24C, and 24K. This operation is performed sequentially in each color image forming unit 30Y, 30M, 30C, and 30K, so that the toner images of Y, M, C, and K are sequentially superimposed and transferred onto the intermediate transfer belt 22, forming a color image. This color image is secondarily transferred to the sheet 8 as the sheet 8 passes through the nip between the intermediate transfer belt 22 and the secondary transfer roller 23. Any toner remaining on the intermediate transfer belt 22 that is not secondarily transferred to the sheet 8 is recovered by a cleaning means (not shown).

[0041] Above the intermediate transfer belt 22, toner bottles 40Y, 40M, 40C, and 40K of each color and a sub-hopper unit 36 ​​are provided. The sub-hopper unit 36 ​​is equipped with sub-hoppers 37Y, 37M, 37C, and 37K corresponding to the colors Y, M, C, and K. The toner bottles 40Y, 40M, 40C, and 40K of each color supply toner to the corresponding sub-hoppers 37Y, 37M, 37C, and 37K. In addition, joints 38Y, 38M, 38C, and 38K capable of supplying toner are connected to the sub-hoppers 37Y, 37M, 37C, and 37K of each color, and toner is supplied from the sub-hoppers 37Y, 37M, 37C, and 37K of each color to the developer units 34 of the image forming units 30Y, 30M, 30C, and 30K of each color via the joints 38Y, 38M, 38C, and 38K.

[0042] Sub-hoppers 37Y, 37M, 37C, and 37K are capable of storing a predetermined amount of toner inside them. The developer unit 34 of the image forming unit 30Y, 30M, 30C, and 30K is equipped with a toner concentration sensor that detects the toner concentration inside the developer unit 34. When the toner concentration inside the developer unit 34 decreases, toner is supplied from sub-hoppers 37Y, 37M, 37C, and 37K to the developer unit 34 via joints 38Y, 38M, 38C, and 38K. Also, when the amount of toner remaining inside sub-hoppers 37Y, 37M, 37C, and 37K becomes low, toner is replenished to sub-hoppers 37Y, 37M, 37C, and 37K from toner bottles 40Y, 40M, 40C, and 40K.

[0043] The toner bottles 40Y, 40M, 40C, and 40K are containers that hold toner of each color and are detachable from the bottle mounting section 2d provided on the main body of the device. The operation of replenishing toner from the toner bottles 40Y, 40M, 40C, and 40K to the sub-hoppers 37Y, 37M, 37C, and 37K is performed by rotating the toner bottles 40Y, 40M, 40C, and 40K. If the toner level inside the sub-hoppers 37Y, 37M, 37C, and 37K does not increase even after the toner replenishment operation, it is determined that the toner inside the toner bottles 40Y, 40M, 40C, and 40K has run out, and a guidance screen prompting the user to replace the toner bottles 40Y, 40M, 40C, and 40K is displayed on the operation panel 6. This allows the user to recognize when toner bottles 40Y, 40M, 40C, and 40K need replacing, and to open the door component 2c to replace the toner bottles 40Y, 40M, 40C, and 40K. In the following, when the individual toner bottles 40Y, 40M, 40C, and 40K are not distinguished, they will be collectively referred to as "toner bottle 40".

[0044] Figure 3 is a perspective view showing multiple toner bottles 40 mounted in the bottle mounting section 2d. The toner bottles 40 are mounted in the image forming apparatus 1 by being inserted into the bottle mounting section 2d in the direction of arrow F3. Conversely, when removing the toner bottles 40 from the image forming apparatus 1, the toner bottles 40 are pulled out in the opposite direction of arrow F3.

[0045] As shown in Figure 3, for example, the toner bottle 40 has a generally cylindrical shape and includes a bottle body 43 that contains toner and a cap portion 44 provided at the front end of the bottle body 43. The bottle body 43 and the cap portion 44 are assembled to be rotatable relative to each other. The toner bottle 40 is mounted so that the cap portion 44 is supported on the upper side of the sub-hopper unit 36. The cap portion 44 has a supply port for supplying toner to the sub-hoppers 37Y, 37M, 37C, and 37K, and the supply port is opened when the toner bottle 40 is mounted on the bottle mounting portion 2d.

[0046] A spiral groove 45 is formed on the outer surface of the bottle body 43. This groove 45 forms a spiral wall that protrudes inward from the bottle body 43, and as the toner bottle 40 rotates in a predetermined direction (direction R shown in Figure 3), it has the function of conveying the toner inside the bottle towards the cap portion 44 while stirring it. Furthermore, a protrusion 46 is provided on a part of the outer surface of the bottle body 43 in the circumferential direction.

[0047] A holding portion 51 is provided on the back side (bottom side) of the toner bottle 40 to rotatably hold the toner bottle 40. The toner bottle 40 is mounted so that its back side engages with the holding portion 51. The holding portion 51 includes a rotating member 52 that engages with the back of each toner bottle 40 to rotate the toner bottle 40 in a predetermined direction (direction R shown in Figure 3), and a drive source 50 that rotates the toner bottle 40. In this embodiment, the holding portion 51 is provided as two separate holding portions: a holding portion 51a that holds the back sides of two toner bottles 40Y and 40M, and a holding portion 51b that holds the back sides of two other toner bottles 40C and 40K. Therefore, the holding portion 51a has two rotating members 52 that engage with the backs of the respective toner bottles 40Y and 40M, and a motor 50a provided as the drive source 50. Furthermore, the holding unit 51b has two rotating members 52 that engage with the backs of the toner bottles 40C and 40K, respectively, and a motor 50b provided as a drive source 50. The motors 50a and 50b are, for example, stepping motors and are rotationally driven by the control unit 7. Inside the holding units 51a and 51b, there is a link mechanism that transmits the rotation of the motors 50a and 50b to the rotating members 52, causing the rotating members 52 to rotate in a predetermined direction. This link mechanism is equipped with a clutch function, allowing the motors 50a and 50b to selectively select one of the two toner bottles 40 and rotate it in a predetermined direction. For example, when motor 50a rotates in the forward direction, the rotating member 52 engaged with the back of toner bottle 40Y rotates, and when it rotates in the reverse direction, the rotating member 52 engaged with the back of toner bottle 40M rotates. The same applies to motor 50b; for example, when motor 50b rotates in the forward direction, the rotating member 52 engaged with the back of toner bottle 40C rotates, and when it rotates in the reverse direction, the rotating member 52 engaged with the back of toner bottle 40K rotates.

[0048] Furthermore, the bottle mounting section 2d has a support section 53 that supports the outer circumferential surface of the toner bottle 40 mounted in the image forming apparatus 1. This support section 53 rotatably supports the outer circumferential surface of the toner bottle 40, on which the protrusion 46 is provided in the longitudinal direction.

[0049] Furthermore, the bottle mounting section 2d is equipped with a remaining amount detection sensor 41 for detecting the remaining amount of toner inside the bottle body 43 and a toner adhesion detection sensor 42 for detecting whether or not toner is adhering to the inner wall of the bottle body 43, located close to the outer surface of the bottle body 43 of each toner bottle 40. The remaining amount detection sensor 41 detects the remaining amount of toner 9 by irradiating light onto the outer surface of the bottle body 43 and detecting the reflected light from inside the bottle body 43, as shown in Figure 4, for example. The toner adhesion detection sensor 42 is composed of line sensors arranged along the longitudinal direction of the bottle body 43, and detects whether or not toner is adhering to the inner wall over the entire longitudinal direction of the bottle body 43 by irradiating light onto the outer surface of the bottle body 43 and detecting the reflected light from inside the bottle body 43.

[0050] Figure 4 shows the cross-sectional structure of the toner bottle 40 and the support part 53. As shown in Figure 4, the toner adhesion detection sensor 42 detects the toner 9a that adheres to the inner wall of the bottle body 43 and rotates together with the bottle body 43. In addition, since a spiral wall 45a formed by grooves 45 protrudes from the inside of the bottle body 43, as the bottle body 43 rotates in a predetermined direction (R direction), the toner 9 inside the bottle body 43 is agitated by the rotating spiral wall 45a and moves toward the cap part 44, and is supplied from the supply port provided in the cap part 44 to the sub-hoppers 37Y, 37M, 37C, and 37K.

[0051] The support portion 53 is joined to the outer circumferential surface of the bottle body 43, which is provided with the protrusion 46, and has a support surface that rotatably supports the bottle body 43. The support portion 53 has a recess 54 on its support surface. The recess 54 is for dropping the protrusion 46 formed on the outer circumferential surface of the bottle body 43 into it, and for applying vibration to the toner bottle 40. In other words, the protrusion 46 formed on the outer circumferential surface of the bottle body 43 and the recess 54 formed in the support portion 53 function as a vibration-applying portion 55 that applies vibration to the toner bottle 40. Here, it is preferable that the protrusion 46 formed on the bottle body 43 has tapered stepped portions 46a and 46b on the upstream and downstream sides in the rotation direction (R direction), and that it tapers towards the tip of the protrusion 46. Also, it is preferable that the recess 54 formed on the support portion 53 has a steeply sloping stepped portion 54a on the upstream side in the rotation direction (R direction), and no step on the downstream side, forming a slope 54b.

[0052] Figure 5 shows the state before and after the protrusion 46 falls into the recess 54. As shown in Figure 5(a), when the bottle body 43 rotates and the protrusion 46 comes into contact with the support surface of the support part 53, the bottle body 43 is lifted by the protrusion 46 and rotates in the rotational direction (R direction). When the protrusion 46 rotates to the position of the recess 54 in this state, the protrusion 46 falls into the recess 54, as shown in Figure 5(b). At this time, vibration is applied to the bottle body 43, and an impact due to the vibration acts on the inside of the bottle body 43. The toner 9a adhering to the inner wall is detached from the inner wall by this impact. In addition, the impact due to the vibration can also loosen the toner 9 that has aggregated and hardened inside the bottle body 43. After that, when the bottle body 43 rotates further, the protrusion 46 moves along the slope 54b and detaches from the recess 54. In this way, the vibration applying unit 55 is configured to apply one vibration to the toner bottle 40 during one rotation of the toner bottle 40. Furthermore, by providing multiple protrusions 46 along the outer surface of the toner bottle 40, it is possible to apply multiple vibrations to the toner bottle 40 during one rotation.

[0053] In the above, an example was described in which the convex portion 46 is formed on the bottle body 43 and the concave portion 54 is formed on the support portion 53. However, a different configuration may be adopted. Figure 6 shows an example of a configuration in which the convex portion 46 is formed on the support portion 53 and the concave portion 54 is formed on the bottle body 43. The bottle body 43 shown in Figure 6 has a concave portion 54 on its outer circumferential surface. This concave portion 54 has a steeply sloping step portion 54a on the downstream side in the rotational direction of the bottle body 43 and a slope 54b on the upstream side. The support portion 53 also has a convex portion 46 on the support surface that supports the bottle body 43. This convex portion 46 is formed, for example, by tapering the step portions 46a and 46b on the upstream and downstream sides in the rotational direction of the bottle body 43, and tapering towards the tip of the convex portion 46. In the above configuration, when the bottle body 43 rotates in the rotational direction and the concave portion 54 reaches the position of the convex portion 46, the convex portion 46 fits into the concave portion 54 and the bottle body 43 falls. At this time, vibration is applied to the bottle body 43, and the impact caused by the vibration acts on the inside of the bottle body 43. Therefore, the vibration applying unit 55 may have a configuration as shown in Figure 6.

[0054] Next, Figure 7 is a block diagram showing the configuration of the control unit 7 that rotates the toner bottle 40. The control unit 7 comprehensively controls the execution of jobs in the image forming apparatus 1. Furthermore, when the amount of toner remaining inside the sub-hoppers 37Y, 37M, 37C, and 37K falls below a predetermined amount, the control unit 7 rotates the motors 50a and 50b to rotate the toner bottles 40Y, 40M, 40C, and 40K and supply toner to the sub-hoppers 37Y, 37M, 37C, and 37K. Figure 7 shows the control mechanism for rotating the motors 50a and 50b.

[0055] As shown in Figure 7, the control unit 7 comprises a CPU 60, a storage unit 61, and motor drive circuits 62a and 62b. The CPU 60 is a hardware processor that reads and executes the program 63 stored in the storage unit 61. The storage unit 61 is a storage device composed of, for example, non-volatile memory, and stores the computer-readable program 63. In addition to the program 63, the storage unit 61 can also store various other data. The motor drive circuit 62a is a circuit that drives the motor 50a based on a signal output from the CPU 60. The motor drive circuit 62b is a circuit that drives the motor 50b based on a signal output from the CPU 60.

[0056] Furthermore, the control unit 7 is connected to the aforementioned toner level detection sensor 41 and toner adhesion detection sensor 42. In addition, the control unit 7 is connected to an environmental sensor 71 and a human body detection sensor 74. The environmental sensor 71 includes a temperature sensor 72 and a humidity sensor 73, and is a sensor that detects the temperature and humidity of the environment in which the image forming apparatus 1 is installed. The human body detection sensor 74 is a sensor that detects people in the vicinity of the image forming apparatus 1, and is composed of, for example, an infrared sensor.

[0057] The control unit 7, having the above configuration, detects when the toner level in any of the sub-hoppers 37Y, 37M, 37C, or 37K falls below a predetermined amount, identifies the toner bottle 40 to be replenished, and identifies the motors 50a and 50b that will rotate the identified toner bottle 40. The control unit 7 then drives the identified motor 50a to rotate. For example, the control unit 7 rotates the toner bottle 40 N times (where N is a number greater than or equal to 1) to supply a certain amount of toner from the toner bottle 40 to the sub-hoppers 37Y, 37M, 37C, or 37K. In other words, the toner replenishment operation, which supplies toner from the toner bottle 40 to the sub-hoppers 37Y, 37M, 37C, or 37K, is the operation of rotating the toner bottle 40 N times.

[0058] When the toner bottle 40 rotates, vibration is applied to the toner bottle 40 by the vibration-applying unit 55 described above. The control unit 7 drives motors 50a and 50b to reduce the vibration noise generated when vibration is applied to the toner bottle 40 by the vibration-applying unit 55. The vibration noise generated when vibration is applied to the toner bottle 40 becomes louder when the amount of toner remaining in the toner bottle 40 is less than a predetermined amount, causing discomfort to those nearby. Therefore, the control unit 7 drives motors 50a and 50b to reduce the vibration noise, especially when the amount of toner remaining in the toner bottle 40 is less than a predetermined amount. Specifically, the control unit 7 is configured to reduce vibration noise by changing the impact of the vibration applied to the toner bottle 40 by the vibration-applying unit 55. The control unit 7 described below will be explained in detail.

[0059] The CPU 60 of the control unit 7 functions as a toner level detection unit 64, a toner adhesion detection unit 65, a temperature and humidity detection unit 66, a human detection unit 67, and a motor control unit 68 by executing the program 63.

[0060] The remaining toner detection unit 64 detects the remaining amount of toner in the toner bottle 40 that has been identified as the target for toner replenishment. For example, the remaining toner detection unit 64 detects the remaining amount of toner in the toner bottle 40 based on the detection results of the remaining toner detection sensor 41 located near the toner bottle 40 that has been identified as the target for toner replenishment among a plurality of toner bottles 40Y, 40M, 40C, 40K, and determines whether the remaining amount of toner in the identified toner bottle 40 is greater than a predetermined amount. The remaining toner detection unit 64 then outputs the toner remaining amount determination result to the motor control unit 68.

[0061] The toner adhesion detection unit 65 detects whether or not aggregated toner is adhering to the inner wall of the toner bottle 40 identified as the target for toner replenishment. Based on the detection results of the toner adhesion detection sensors 42 located in close proximity to the toner bottle 40 identified as the target for toner replenishment among the multiple toner bottles 40Y, 40M, 40C, and 40K, the toner adhesion detection unit 65 determines whether or not toner is adhering to the inner wall of the toner bottle 40 and outputs the determination result to the motor control unit 68.

[0062] The temperature and humidity detection unit 66 detects the temperature and humidity of the environment in which the image forming apparatus 1 is installed. Based on the detection results from the environmental sensor 71, the temperature and humidity detection unit 66 detects the temperature and humidity in the environment in which the image forming apparatus 1 is installed.

[0063] The human detection unit 67 detects whether or not there are people around the image forming apparatus 1. The human detection unit 67 detects whether or not there are people around the image forming apparatus 1 based, for example, on the detection results of the human body detection sensor 74.

[0064] The motor control unit 68 operates the motor drive circuits 62a and 62b to drive the motors 50a and 50b, thereby controlling the rotation of the toner bottle 40. Depending on the toner bottle 40 identified as the target for toner replenishment, the motor control unit 68 identifies one of the two motor drive circuits 62a and 62b as the target to drive and operates the identified motor drive circuits 62a and 62b.

[0065] For example, the motor control unit 68 operates the motor drive circuits 62a and 62b by outputting three control signals SG1, SG2, and SG3 to the motor drive circuits 62a and 62b that it has identified as targets for driving.

[0066] The control signal SG1 is a signal that specifies whether the rotation direction of motors 50a and 50b is forward or reverse. The motor control unit 68 determines the rotation direction of motors 50a and 50b according to the toner bottle 40 identified as the target for toner replenishment, and outputs the control signal SG1 based on the result of that determination. For example, the control signal SG1 is a binary signal that is turned on when the rotation direction of motors 50a and 50b is forward, and turned off when it is reverse.

[0067] The control signal SG2 is a signal that sets the strength of the current I used by the motor drive circuits 62a and 62b to rotate the motors 50a and 50b. When the current I used to rotate the motors 50a and 50b increases, the torque of the motors 50a and 50b increases, and the toner bottle 40 rotates more vigorously due to the increased torque. Conversely, when the current I decreases, the torque of the motors 50a and 50b decreases, and the momentum with which the toner bottle 40 rotates decreases. Therefore, the motor control unit 68 can change the momentum with which the toner bottle 40 rotates by changing the strength of the current I. For example, the control signal SG2 is generated as a pulse signal with a predetermined period, and the strength of the current I is specified by changing the proportion of the period during which it is ON (duty cycle) within one period.

[0068] The control signal SG3 is a signal that sets the rotational speed of motors 50a and 50b. For example, the control signal SG3 is generated as a pulse signal that repeatedly switches on and off, and the rotational speed of motors 50a and 50b is set by changing the period of repeated on and off cycles.

[0069] The motor drive circuits 62a and 62b are connected to a DC24V power supply. When the motor control unit 68 inputs control signals SG1, SG2, and SG3, they output a current I based on these control signals SG1, SG2, and SG3 to the motors 50a and 50b, thereby rotating the motors 50a and 50b.

[0070] In the above configuration, the motor control unit 68 controls the vibration impact applied to the toner bottle 40 by the vibration application unit 55 while the toner bottle 40 is rotating, according to the detection result of the remaining amount detection unit 64. The vibration impact applied to the toner bottle 40 by the vibration application unit 55 can be changed, for example, by changing the momentum at which the toner bottle 40 rotates. Therefore, the motor control unit 68 in this embodiment is configured to change the vibration impact by changing the torque of the motors 50a and 50b. That is, the motor control unit 68 changes the torque of the motors 50a and 50b by changing the strength of the current I supplied to the motors 50a and 50b according to the detection result of the remaining amount detection unit 64, and thereby changes the vibration impact applied by the vibration application unit 55.

[0071] For example, if the remaining toner level detection unit 64 detects that the remaining toner level in the toner bottle 40 is higher than a predetermined amount, the motor control unit 68 sets the current I to a normal current value using the control signal SG2. Conversely, if the remaining toner level detection unit 64 detects that the remaining toner level in the toner bottle 40 is lower than a predetermined amount, the motor control unit 68 sets the current I to a current value lower than the normal current value using the control signal SG2. As a result, when the remaining toner level in the toner bottle 40 falls below a predetermined amount, the impact when vibration is applied by the vibration application unit 55 can be reduced, and therefore the vibration noise caused by the vibration can also be reduced.

[0072] For example, if toner is not adhering to the inner wall of the bottle body 43, or if the toner has not aggregated and solidified inside the bottle body 43, the motor control unit 68 can reduce the impact caused by vibration as much as possible by driving the motors 50a and 50b with the lower limit of the current I that can rotate them, thereby minimizing vibration noise. As a result, even if there are people around the image forming apparatus 1, it is possible to suppress causing them discomfort.

[0073] On the other hand, if toner is adhering to the inner wall of the bottle body 43, reducing the vibration shock too much will prevent the toner from being detached from the inner wall. Similarly, if toner has aggregated and hardened inside the bottle body 43, reducing the vibration shock too much will prevent the hardened toner from being loosened. Therefore, when toner is adhering to the inner wall of the bottle body 43, or when toner has aggregated and hardened inside the bottle body 43, the motor control unit 68 sets the current I used to drive the motors 50a and 50b to a value smaller than the normal current value and larger than the lower limit of current I, so that a certain amount of shock can be applied to the toner bottle 40 by vibration. This suppresses the generation of vibration noise while enabling the toner adhering to the inner wall of the bottle body 43 to be detached from the inner wall, and also loosening the aggregated and hardened toner.

[0074] For example, if the amount of toner remaining in the toner bottle 40 is less than a predetermined amount, the motor control unit 68 determines whether or not toner is adhering to the inner wall of the bottle body 43 based on the detection result from the toner adhesion detection unit 65. If, as a result, toner is not adhering to the inner wall of the bottle body 43, the motor control unit 68 drives the motors 50a and 50b at the lower limit of the current I that can rotate them. On the other hand, if toner is adhering to the inner wall of the bottle body 43, the motor control unit 68 sets the current I to a value that is smaller than the normal current value and larger than the lower limit of the current I, and drives the motors 50a and 50b.

[0075] Furthermore, if the amount of toner remaining in the toner bottle 40 is less than a predetermined amount, the motor control unit 68 determines, based on the detection result of the temperature and humidity detection unit 66, whether or not the environment is such that the toner is likely to aggregate and solidify. For example, if the temperature is below a predetermined temperature and the humidity is below a predetermined humidity, it can be said that the environment is such that the toner is likely to aggregate and solidify. Therefore, if the environment is such that the toner is likely to aggregate and solidify, the motor control unit 68 sets the current I to a value that is smaller than the normal current value and larger than the lower limit of the current I, and drives the motors 50a and 50b. On the other hand, if the environment is not such that the toner is likely to aggregate and solidify, the motor control unit 68 drives the motors 50a and 50b with the lower limit of the current I that is capable of rotating the motors 50a and 50b.

[0076] Figure 8 shows the current supplied to motors 50a and 50b when driving them. When driving motor 50a, a current with a waveform (sine wave) as shown in Figure 8 is supplied to motors 50a and 50b. Figure 8 shows three types of currents I1, I2, and I3 with different intensities. All three types of currents I1, I2, and I3 have the same period T. The period T defines the rotational speed of motors 50a and 50b. Therefore, the three types of currents I1, I2, and I3 can rotate motors 50a and 50b at the same rotational speed.

[0077] For example, if the toner level in the toner bottle 40 is higher than a predetermined amount, the motor control unit 68 drives the motors 50a and 50b with a first current I1, which is the one with the largest peak in the current waveform among the three types of currents. In other words, the first current I1 is the normal current value set when the toner level is higher than a predetermined amount.

[0078] Furthermore, if the toner level in the toner bottle 40 is less than a predetermined amount, the motor control unit 68 drives the motors 50a and 50b with either the second current I2 or the third current I3, which are among the three types of currents and whose peak current waveform is smaller than that of the first current I1. Here, the second current I2 is the current with the smallest peak current waveform, and is the lower limit of the current that can rotate the motors 50a and 50b. The third current I3 is a current whose peak current waveform is smaller than that of the first current I1 and larger than that of the second current I2.

[0079] For example, the motor control unit 68 drives the motors 50a and 50b with a second current I2 when the amount of toner remaining in the toner bottle 40 is less than a predetermined amount and there is no toner adhering to the inner wall of the bottle body 43. The motor control unit 68 also drives the motors 50a and 50b with a second current I2 when the amount of toner remaining in the toner bottle 40 is less than a predetermined amount and the environment is not conducive to toner agglomeration and solidification. This reduces the momentum with which the toner bottle 40 rotates, thereby suppressing vibration noise when the toner bottle 40 is subjected to vibration.

[0080] Furthermore, the motor control unit 68 drives the motors 50a and 50b with a third current I3 when the amount of toner remaining in the toner bottle 40 is less than a predetermined amount and toner is adhering to the inner wall of the bottle body 43. The motor control unit 68 also drives the motors 50a and 50b with a third current I3 when the amount of toner remaining in the toner bottle 40 is less than a predetermined amount and the environment is such that the toner is likely to aggregate and harden. This suppresses the generation of vibration noise, while also allowing the toner adhering to the inner wall of the bottle body 43 to be detached from the inner wall and loosening the toner that has aggregated and hardened.

[0081] Next, we will illustrate some processing procedures performed in the control unit 7 of the image forming apparatus 1. First, Figure 9 is a flowchart of the first processing procedure performed by the control unit 7. This first processing procedure is a basic processing procedure performed in the control unit 7. When the control unit 7 starts the first processing procedure, it determines whether or not there is a request to replenish toner for any of the sub-hoppers 37Y, 37M, 37C, or 37K (step S1). If there is a request to replenish toner (YES in step S1), the control unit 7 identifies the toner bottle 40 to be replenished (step S2). By identifying the toner bottle 40, it is possible to identify the motor to be driven from among the two motors 50a and 50b, and also to identify the rotation direction of the motor to be driven.

[0082] The control unit 7 detects the remaining toner amount in the identified toner bottle 40 (step S3). For example, the control unit 7 detects the remaining toner amount based on the detection result of the remaining toner detection sensor 41. The control unit 7 then determines whether the remaining toner amount in the toner bottle 40 is greater than a predetermined amount (step S4). If the remaining toner amount is greater than a predetermined amount (YES in step S4), the control unit 7 sets the drive current of the motor identified as the target to be driven to a first current I1, which is the normal current value (step S5). Conversely, if the remaining toner amount is less than or equal to the predetermined amount (NO in step S4), the control unit 7 sets the drive current of the motor to a second current I2, which is a current value smaller than the normal current value (step S6).

[0083] Subsequently, the control unit 7 starts driving the motor (step S7). That is, the control unit 7 outputs control signals SG1, SG2, and SG3 to one of the two motor drive circuits 62a and 62b, operating either motor drive circuit 62a or 62b. At this time, control signal SG1 is a signal to rotate the identified toner bottle 40 in a predetermined direction. Control signal SG2 is a signal to specify the current value set in step S5 or S6. Furthermore, control signal SG3 is a signal to rotate the toner bottle 40 at a predetermined rotational speed. As a result, current I flows from motor drive circuit 62a or 62b to motor 50a or 50b, and the rotation of motor 50a or 50b rotates the toner bottle 40, supplying toner from the toner bottle 40 to sub-hoppers 37Y, 37M, 37C, and 37K.

[0084] When the motor starts to drive, the control unit 7 counts the number of rotations of the toner bottle 40 and determines whether the toner replenishment operation is complete (step S8). That is, the control unit 7 determines that the toner replenishment operation is complete when the toner bottle 40 has rotated N times. When it determines that the toner replenishment operation is complete (YES in step S8), the control unit 7 stops the motor (step S9). This completes the first processing procedure.

[0085] In this first processing procedure, when the remaining toner is less than a predetermined amount, the drive current of the motors 50a and 50b becomes a second current I2 which is smaller than the first current I1. As a result, the momentum with which the toner bottle 40 rotates decreases compared to when the remaining toner is more than a predetermined amount. Therefore, the impact when the vibration-applying unit 55 applies vibration to the toner bottle 40 can be suppressed, and the vibration noise can be kept low. Consequently, it is possible to reduce the discomfort caused to people around the image forming apparatus 1.

[0086] Next, Figure 10 is a flowchart of the second processing procedure performed by the control unit 7. When the control unit 7 starts the second processing procedure, it determines whether or not there is a toner replenishment request for any of the sub-hoppers 37Y, 37M, 37C, or 37K (step S10). If there is a toner replenishment request (YES in step S10), the control unit 7 identifies the toner bottle 40 to be replenished (step S11). The control unit 7 then detects the remaining toner amount of the identified toner bottle 40 (step S12) and determines whether or not the remaining toner amount is greater than a predetermined amount (step S13). If the remaining toner amount is greater than a predetermined amount (YES in step S13), the control unit 7 sets the motor drive current to the first current I1, which is the normal current value (step S14).

[0087] On the other hand, if the remaining toner amount is less than a predetermined amount (NO in step S13), the control unit 7 detects toner adhesion to the inner wall of the identified toner bottle 40 (step S15). For example, the control unit 7 detects toner adhering to the inner wall of the toner bottle 40 based on the detection result of the toner adhesion detection sensor 42. The control unit 7 then determines whether or not toner is adhering to the inner wall of the toner bottle 40 (step S16). As a result, if no toner is adhering to the inner wall of the toner bottle 40 (NO in step S16), the control unit 7 sets the motor drive current to a second current I2, which is a current value smaller than the first current I1 (step S17). Conversely, if toner is adhering to the inner wall of the toner bottle 40 (YES in step S16), the control unit 7 sets the motor drive current to a third current I3, which is a current value smaller than the first current I1 and larger than the second current I2 (step S18).

[0088] Subsequently, the control unit 7 starts driving the motor (step S19) and determines whether the toner replenishment operation is complete (step S20). If it determines that the toner replenishment operation is complete (YES in step S20), the control unit 7 stops the motor (step S21). This completes the second processing procedure.

[0089] In this second processing step, when the remaining toner amount is less than a predetermined amount, it is determined whether or not toner is adhering to the inner wall of the toner bottle 40. If no toner is adhering to the inner wall, the drive current of motors 50a and 50b is set to the second current I2. If toner is adhering to the inner wall, the drive current of motors 50a and 50b is set to the third current I3. Therefore, if no toner is adhering to the inner wall of the toner bottle 40, the vibration noise when vibration is applied by the vibration applying unit 55 can be suppressed to the greatest extent possible. Furthermore, if toner is adhering to the inner wall of the toner bottle 40, it is possible to apply the necessary impact to peel the toner off the inner wall while suppressing the vibration noise.

[0090] Next, Figure 11 is a flowchart of the third processing procedure performed by the control unit 7. When the control unit 7 starts the third processing procedure, it determines whether or not there is a toner replenishment request for any of the sub-hoppers 37Y, 37M, 37C, or 37K (step S30). If there is a toner replenishment request (YES in step S30), the control unit 7 identifies the toner bottle 40 to be replenished (step S31). The control unit 7 then detects the remaining toner amount of the identified toner bottle 40 (step S32) and determines whether or not the remaining toner amount is greater than a predetermined amount (step S33). If the remaining toner amount is greater than a predetermined amount (YES in step S33), the control unit 7 sets the motor drive current to the first current I1, which is the normal current value (step S34).

[0091] On the other hand, if the remaining toner is less than a predetermined amount (NO in step S33), the control unit 7 detects the temperature and humidity of the environment in which the image forming apparatus 1 is installed (step S35). For example, the control unit 7 detects the temperature and humidity based on the detection results of the environmental sensor 71. The control unit 7 then determines whether the temperature is lower than a predetermined temperature and the humidity is lower than a predetermined humidity (step S36). As a result, if the temperature is higher than a predetermined temperature or the humidity is higher than a predetermined humidity (NO in step S36), the control unit 7 sets the motor drive current to a second current I2, which is a current value smaller than the first current I1 (step S37). Conversely, if the temperature is lower than a predetermined temperature and the humidity is lower than a predetermined humidity (YES in step S36), the control unit 7 sets the motor drive current to a third current I3, which is a current value smaller than the first current I1 and larger than the second current I2 (step S38).

[0092] Subsequently, the control unit 7 starts driving the motor (step S39) and determines whether the toner replenishment operation is complete (step S40). If it determines that the toner replenishment operation is complete (YES in step S40), the control unit 7 stops the motor (step S41). This completes the third processing procedure.

[0093] In this third processing step, when the remaining toner amount is less than a predetermined amount, it is determined whether or not the environment is conducive to toner agglomeration and hardening. If the environment is not conducive to toner agglomeration, the drive current of motors 50a and 50b is set to the second current I2. If the environment is conducive to toner agglomeration, the drive current of motors 50a and 50b is set to the third current I3. Therefore, if the environment is not conducive to toner agglomeration, the vibration noise when vibration is applied by the vibration applying unit 55 can be suppressed to the greatest extent possible. Furthermore, if the environment is conducive to toner agglomeration, it is possible to apply the necessary impact to loosen the agglomerated and hardened toner while suppressing the vibration noise.

[0094] Furthermore, a processing procedure combining the second and third processing procedures described above may be adopted. That is, when the remaining toner amount is less than a predetermined amount, the control unit 7 determines whether or not toner is adhering to the inner wall of the toner bottle 40, and also determines whether or not the environment is such that toner is likely to aggregate and solidify. As a result, if toner is adhering to the inner wall of the toner bottle 40, or if the environment is such that toner is likely to aggregate and solidify, the control unit 7 sets the drive current of the motors 50a and 50b to the third current I3. On the other hand, if there is no toner adhering to the inner wall of the toner bottle 40, and the environment is not such that toner is likely to aggregate and solidify, the control unit 7 sets the drive current of the motors 50a and 50b to the second current I2, which can minimize the generation of vibration noise.

[0095] Next, Figure 12 is a flowchart of the fourth processing procedure performed by the control unit 7. If there are no people around the image forming apparatus 1, even if relatively loud vibration noise is generated, it does not cause problems. Therefore, in this fourth processing procedure, the control unit 7 determines whether or not there are people around the image forming apparatus 1 and sets the drive current of the motors 50a and 50b. When the control unit 7 starts the fourth processing procedure, it determines whether or not there is a request to replenish toner for any of the sub-hoppers 37Y, 37M, 37C, and 37K (step S50). If there is a request to replenish toner (YES in step S50), the control unit 7 identifies the toner bottle 40 to which the toner replenishment is to be made (step S51). The control unit 7 then detects the remaining amount of toner in the identified toner bottle 40 (step S52) and determines whether or not the remaining amount of toner is greater than a predetermined amount (step S53). If the remaining amount of toner is greater than a predetermined amount (YES in step S53), the control unit 7 sets the drive current of the motors 50a and 50b to the first current I1, which is the normal current value (step S54).

[0096] Furthermore, if the toner level is lower than a predetermined amount (NO in step S53), the control unit 7 performs a human detection process (step S55) to determine whether or not there are people around the image forming apparatus 1 (step S56). For example, the control unit 7 has the human body detection sensor 74 perform human detection and determines whether or not there are people around the image forming apparatus 1 based on the detection result of the human body detection sensor 74. If, as a result, there are no people around the image forming apparatus 1 (NO in step S56), the control unit 7 sets the drive current of the motors 50a and 50b to the first current I1, which is the normal current value (step S54). In other words, even if the image forming apparatus 1 generates a relatively loud vibration noise, the control unit 7 sets the drive current of the motors 50a and 50b to the first current I1, which is the normal current value, so as not to cause discomfort to people in the vicinity.

[0097] In contrast, if there are people around the image forming apparatus 1 (YES in step S56), the control unit 7 sets the drive current of the motors 50a and 50b to a second current I2, which is smaller than the normal current value (step S57). That is, in order to avoid causing discomfort to people around the image forming apparatus 1, the control unit 7 suppresses the impact applied to the toner bottle 40 during its rotation and suppresses the generation of vibration noise. At this time, the control unit 7 may determine whether or not toner is adhering to the inner wall of the toner bottle 40, or whether or not the environment is such that toner is likely to aggregate and solidify, as described in the second or third processing procedure, and set the drive current of the motors 50a and 50b to either the second current I2 or the third current I3 based on the result of that determination.

[0098] Subsequently, the control unit 7 starts driving the motors 50a and 50b (step S58) and determines whether the toner replenishment operation is complete (step S59). If it determines that the toner replenishment operation is complete (YES in step S59), the control unit 7 stops the motors (step S60). This completes the fourth processing procedure.

[0099] As described above, the image forming apparatus 1 of this embodiment has a configuration that applies vibration to the toner bottle 40 as it rotates, thereby detaching toner adhering to the inner wall of the toner bottle 40 from the inner wall and loosening toner that has aggregated and hardened. The image forming apparatus 1 is configured to detect the remaining amount of toner inside the toner bottle 40 and to change the impact of the vibration applied to the toner bottle 40 during its rotation based on the detection result. The image forming apparatus 1 having such a configuration can adjust the vibration noise when vibration is applied to the toner bottle 40. Therefore, the image forming apparatus 1 can suppress causing discomfort to people in the vicinity due to vibration noise.

[0100] (Second Embodiment) Next, a second embodiment of the present invention will be described. In the first embodiment described above, a toner level detection sensor 41 was provided to measure the remaining amount of toner in the toner bottle 40. In this embodiment, an example of a configuration that can detect the remaining amount of toner without providing a toner level detection sensor 41 will be described.

[0101] Figure 13 is a block diagram showing an example configuration of the control unit 7 in the second embodiment. The difference between the control unit 7 shown in Figure 13 and the first embodiment is that current detection units 75a and 75b are connected to the motor drive circuits 62a and 62b. The current detection units 75a and 75b are circuits that detect the current I supplied to the motors 50a and 50b by the motor drive circuits 62a and 62b when the motor drive circuits 62a and 62b operate and drive the motors 50a and 50b. The current I flowing through the motors 50a and 50b fluctuates according to the load on the motors 50a and 50b. For example, if the load on the motors 50a and 50b is large, the current I flowing through the motors 50a and 50b will also be large. Conversely, if the load on the motors 50a and 50b decreases, the current I flowing through the motors 50a and 50b will also decrease. Therefore, the current detection units 75a and 75b detect the current I when the motor drive circuits 62a and 62b rotate the motors 50a and 50b, and output a current detection signal SG4 corresponding to the current I to the CPU 60 of the control unit 7.

[0102] The toner level detection unit 64 of the CPU 60 detects the remaining toner in the toner bottle 40 based on the current detection signal SG4 output from the current detection units 75a and 75b. As described above, the current I fluctuates according to the load of the motors 50a and 50b, so when the remaining toner in the toner bottle 40 is greater than a predetermined amount, the current I becomes greater than a predetermined current value, and when the remaining toner is less than a predetermined amount, the current I becomes less than a predetermined current value. Therefore, the toner level detection unit 64 determines whether the remaining toner in the toner bottle 40 is greater than a predetermined amount based on the current detection signal SG4. Accordingly, the image forming apparatus 1 of this embodiment can detect the remaining toner in each toner bottle 40 without providing a toner level detection sensor 41 in a position close to the outer surface of the bottle body 43 of each toner bottle 40.

[0103] Figure 14 is a flowchart showing the processing procedure performed by the control unit 7 of the second embodiment. When the control unit 7 starts this processing procedure, it determines whether or not there is a toner replenishment request for any of the sub-hoppers 37Y, 37M, 37C, or 37K (step S70). If there is a toner replenishment request (YES in step S70), the control unit 7 identifies the toner bottle 40 to be replenished (step S71). The control unit 7 then starts driving the motor 50a or 50b that rotates the identified toner bottle 40 (step S72). At this time, the control unit 7 drives the motors 50a and 50b to rotate by supplying a current I corresponding to the load torque of the motors 50a and 50b.

[0104] When the control unit 7 starts driving the motor 50a or 50b, it detects the current I flowing through the motor 50a or 50b (step S73) and detects the remaining toner in the toner bottle 40 based on that current I (step S74). The control unit 7 then determines whether the remaining toner in the toner bottle 40 is greater than a predetermined amount (step S75). If the remaining toner is greater than a predetermined amount (YES in step S75), the control unit 7 changes the motor drive current to a first current I1, which is the normal current value (step S76). In this case, the first current I1 may be greater than the current I at the start of driving the motors 50a and 50b. On the other hand, if the remaining toner is less than or equal to a predetermined amount (NO in step S75), the control unit 7 changes the motor drive current to a second current I2, which is a current value smaller than the normal current value (step S77).

[0105] Furthermore, if the remaining toner amount is below a predetermined amount, the same processing as the second or third processing procedure described in the first embodiment may be performed, and the motor drive current may be changed to either the second current I2 or the third current I3. Alternatively, the fourth processing procedure described in the first embodiment may be applied, and the motor drive current may be changed depending on whether or not there are people around the image forming apparatus 1.

[0106] Subsequently, the control unit 7 determines whether the toner replenishment operation has finished (step S78). If it determines that the toner replenishment operation has finished (YES in step S78), it stops the motor (step S79). This concludes the processing procedure in the second embodiment.

[0107] In this embodiment, the configuration and operation other than those described above are the same as those described in the first embodiment.

[0108] (Third embodiment) Next, a third embodiment of the present invention will be described. In this embodiment, when the amount of toner remaining in the toner bottle 40 is less than or equal to a predetermined amount, the control unit 7 detects the rotational position of the motors 50a and 50b, and switches the current supplied to the motors 50a and 50b from a first current I1 to a second current I2 or a third current I3 at the timing when the motors 50a and 50b have rotated to a predetermined position just before vibration is applied to the toner bottle 40 by the vibration application unit 55.

[0109] Figure 15 is a block diagram showing an example configuration of the control unit 7 in the third embodiment. The difference between the control unit 7 shown in Figure 15 and the first embodiment is that the motor drive circuits 62a and 62b are equipped with detection units 76a and 76b that detect the rotational position of the motors 50a and 50b. The detection units 76a and 76b detect the rotational position of the motors 50a and 50b, which are driven by the respective motor drive circuits 62a and 62b, and output a position signal SG5 indicating the rotational position of the motors 50a and 50b to the motor control unit 68.

[0110] When the motor drive circuits 62a and 62b are operating, the motor control unit 68 can detect the rotational position of motors 50a and 50b in real time based on the position signal SG5 output from the detection units 76a and 76b. Therefore, when the toner level in the toner bottle 40 is below a predetermined amount, the motor control unit 68 switches the current supplied to motors 50a and 50b from the first current I1 to the second current I2 or the third current I3 at the timing when motors 50a and 50b have rotated to a predetermined position just before vibration is applied to the toner bottle 40 by the vibration application unit 55.

[0111] Figure 16 is a flowchart showing the processing procedure performed by the control unit 7 of the third embodiment. When the control unit 7 starts this processing procedure, it determines whether or not there is a toner replenishment request for any of the sub-hoppers 37Y, 37M, 37C, or 37K (step S100). If there is a toner replenishment request (YES in step S100), the control unit 7 identifies the toner bottle 40 to which the toner replenishment is to be performed (step S101). The control unit 7 then detects the remaining toner amount of the identified toner bottle 40 (step S102) and determines whether or not the remaining toner amount of the toner bottle 40 is greater than a predetermined amount (step S103).

[0112] If the remaining toner amount is greater than a predetermined amount (YES in step S103), the control unit 7 sets the drive current of the motor identified as the target to be driven to the first current I1, which is the normal current value (step S104), and starts driving the motor (step S105). After that, the control unit 7 determines whether the toner replenishment operation is complete or not (step S106), and if it determines that the toner replenishment operation is complete (YES in step S106), it stops the motor (step S107).

[0113] Furthermore, if the remaining toner is below a predetermined amount (NO in step S103), the control unit 7 sets the drive current of the motor identified as the target to be driven to a first current I1, which is the normal current value (step S108), and starts driving the motor (step S109). Subsequently, the control unit 7 detects the rotation position of the motor 50a or 50b (step S110) and determines whether the vibration applying unit 55 has reached a predetermined position just before applying vibration to the toner bottle 40 (step S111). If the rotation position of the motor 50a or 50b has not reached the predetermined position (NO in step S111), the control unit 7 continues to drive the motor 50a or 50b with the first current I1. On the other hand, when the rotation position of motor 50a or 50b reaches a predetermined position (YES in step S111), the control unit 7 changes the current I supplied to motor 50a or 50b from the first current I1 to a second current I2 which has a smaller current value than the first current I1 (step S112). As a result, when vibration is applied to the toner bottle 40 by the vibration applying unit 55, the current I supplied to motors 50a and 50b changes to the second current I2.

[0114] Furthermore, when changing the setting of the current I supplied to the motor 50a or 50b in step S112, it is also possible to use a processing procedure similar to the second or third processing procedure described in the first embodiment, which changes the motor drive current to either the second current I2 or the third current I3. Alternatively, the fourth processing procedure described in the first embodiment may be applied to change the motor drive current depending on whether or not there are people around the image forming apparatus 1.

[0115] Subsequently, the control unit 7 determines whether the rotational position of the motor 50a or 50b has passed a predetermined position after vibration has been applied to the toner bottle 40 by the vibration application unit 55 (step S113). If it determines that the predetermined position has passed (step S113), it changes the current I supplied to the motor 50a or 50b back to the first current I1 (step S114).

[0116] The control unit 7 then determines whether the toner replenishment operation is complete (step S115). If it determines that the toner replenishment operation is complete (YES in step S115), it stops the motor (step S116). This completes the processing procedure in the third embodiment.

[0117] As described above, the image forming apparatus 1 of this embodiment is configured to reduce the impact of vibrations applied to the toner bottle 40 and suppress the generation of vibration noise by reducing the current I supplied to the motors 50a and 50b immediately before vibrations are applied to the toner bottle 40 by the vibration application unit 55. Therefore, in this embodiment as well, it is possible to reduce the discomfort caused to people around the image forming apparatus 1.

[0118] In this embodiment, the configuration and operation other than those described above are the same as those described in the first or second embodiment.

[0119] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described. In the first to third embodiments described above, an example was described in which the shock when vibration is applied to the toner bottle 40 by the vibration applying unit 55 is reduced by reducing the current value of the current I supplied to the motor 50a or 50b from the normal current value while the toner bottle 40 is rotated at a predetermined rotational speed. In contrast, in this embodiment, an example will be described in which the shock when vibration is applied to the toner bottle 40 by the vibration applying unit 55 is reduced by reducing the rotational speed of the toner bottle 40 from a predetermined rotational speed.

[0120] The rotation speed of the toner bottle 40 changes in conjunction with the rotation speed of the motors 50a and 50b. Therefore, the motor control unit 68 in this embodiment is configured to change the rotation speed of the motors 50a and 50b by changing the control signal SG3 output to the motor drive circuits 62a and 62b according to the remaining amount of toner in the toner bottle 40, thereby changing the impact of vibration applied to the toner bottle 40 by the vibration application unit 55. For example, when the remaining amount of toner in the toner bottle 40 is greater than a predetermined amount, the motor control unit 68 sets the rotation speed of the motors 50a and 50b to the normal rotation speed. Conversely, when the remaining amount of toner in the toner bottle 40 is less than or equal to a predetermined amount, the motor control unit 68 sets the rotation speed of the motors 50a and 50b to a speed slower than the normal rotation speed. As the rotation speed of the motors 50a and 50b decreases, the rotation speed of the toner bottle 40 also decreases accordingly, so the impact when vibration is applied to the toner bottle 40 by the vibration application unit 55 becomes smaller, and the generation of vibration noise can be suppressed.

[0121] Figure 17 shows the current supplied to motors 50a and 50b when they are driven. When the control unit 7 of this embodiment drives motor 50a, a current with a waveform (sine wave) as shown in Figure 17 is supplied to motors 50a and 50b. Figure 17 shows three types of currents I4, I5, and I6 of the same intensity. These three types of currents I4, I5, and I6 each have different periods. That is, the period T1 of current I4 is shorter than the periods T2 and T3 of the other currents I5 and I6, and the period T2 of current I5 is longer than the periods T1 and T3 of the other currents I4 and I6. Therefore, when motors 50a and 50b are driven with current I4, the rotational speed of motors 50a and 50b is the fastest. Also, when motors 50a and 50b are driven with current I5, the rotational speed of motors 50a and 50b is the slowest. Furthermore, when motors 50a and 50b are driven with current I6, their rotational speeds become an intermediate speed between those when driven with currents I4 and I5.

[0122] For example, if the amount of toner remaining in the toner bottle 40 is greater than a predetermined amount, the motor control unit 68 drives the motors 50a and 50b with the current I4, which has the shortest period among the three types of currents I4, I5, and I6, causing the motors 50a and 50b to rotate at the normal rotational speed V1.

[0123] Furthermore, if the toner level in the toner bottle 40 is below a predetermined amount, the motor control unit 68 drives the motors 50a and 50b with either current I5 or I6, which has a longer period than current I4, among the three types of currents I4, I5, and I6, and sets the rotational speed of the motors 50a and 50b to a speed slower than the normal rotational speed V1. For example, when the current is I5, the rotational speed of the motors 50a and 50b becomes V2, and when the current is I6, the rotational speed of the motors 50a and 50b becomes V3.

[0124] Figure 18 is a flowchart showing the processing procedure performed by the control unit 7 of the fourth embodiment. When the control unit 7 starts this processing procedure, it determines whether or not there is a toner replenishment request for any of the sub-hoppers 37Y, 37M, 37C, or 37K (step S120). If there is a toner replenishment request (YES in step S120), the control unit 7 identifies the toner bottle 40 to which the toner replenishment is to be made (step S121). The control unit 7 then detects the remaining toner amount of the identified toner bottle 40 (step S122) and determines whether or not the remaining toner amount is greater than a predetermined amount (step S123).

[0125] If the remaining toner is greater than a predetermined amount (YES in step S123), the control unit 7 sets the drive current of motor 50a or 50b to current I4 and sets the rotation speed of motor 50a or 50b to the normal rotation speed V1 (step S124). Conversely, if the remaining toner is less than or equal to a predetermined amount (NO in step S123), the control unit 7 sets the drive current of motor 50a or 50b to current I5 or I6 and sets the rotation speed of motor 50a or 50b to a rotation speed V2 or V3 that is slower than the normal rotation speed V1 (step S124). In this case, the same processing as the second or third processing procedure described in the first embodiment is performed, and either current I5 or I6 is set as the drive current of motor 50a or 50b. For example, if the amount of toner remaining in the toner bottle 40 is less than a predetermined amount and there is no toner adhering to the inner wall of the bottle body 43, the control unit 7 sets the drive current of the motors 50a and 50b to current I5 and the rotation speed of the motors 50a and 50b to V2. Conversely, if there is toner adhering to the inner wall of the bottle body 43, the control unit 7 sets the drive current of the motors 50a and 50b to current I6 and the rotation speed of the motors 50a and 50b to V3. In this case, if there is no toner adhering to the inner wall of the bottle body 43, the impact of the vibration applied by the vibration applying unit 55 is suppressed to the greatest extent possible, thus minimizing the generation of vibration noise. Also, if there is toner adhering to the inner wall of the bottle body 43, a certain amount of vibration impact can be ensured by the vibration applying unit 55, so that the toner can be detached from the inner wall of the bottle body 43 while suppressing the generation of vibration noise. Alternatively, a processing procedure may be adopted in which the fourth processing procedure described in the first embodiment is applied to determine whether or not to set the motor rotation speed to a speed slower than the normal rotation speed V1 depending on whether or not there are people around the image forming apparatus 1.

[0126] Subsequently, the control unit 7 starts driving the motor with the current set in step S124 or S125 (step S126). After starting to drive the motor, the control unit 7 determines whether the toner replenishment operation is complete (step S127), and if it determines that the toner replenishment operation is complete (YES in step S127), it stops the motor (step S128). This completes the processing procedure in the fourth embodiment.

[0127] As described above, the image forming apparatus 1 of this embodiment is configured to reduce the impact of vibrations applied to the toner bottle 40 and suppress the generation of vibration noise by setting the rotation speed of the motors 50a and 50b to rotation speeds V2 and V3, which are lower than the normal rotation speed V1, when the remaining amount of toner in the toner bottle 40 is below a predetermined amount, thereby rotating the toner bottle 40. Therefore, in this embodiment as well, it is possible to reduce the discomfort caused to people around the image forming apparatus 1.

[0128] In this embodiment, the configuration and operation other than those described above are the same as those described in any of the first or second embodiments.

[0129] (Fifth embodiment) Next, a fifth embodiment of the present invention will be described. In this embodiment, when the amount of toner remaining in the toner bottle 40 is below a predetermined amount, the control unit 7 detects the rotational position of the motors 50a and 50b, and at the timing when the motors 50a and 50b have rotated to a predetermined position just before vibration is applied to the toner bottle 40 by the vibration application unit 55, the rotational speed of the toner bottle 40 is reduced to a speed slower than the normal rotational speed V1. The configuration of the control unit 7 in this embodiment is the same as that shown in Figure 15.

[0130] Figure 19 is a flowchart showing the processing procedure performed by the control unit 7 of the fifth embodiment. When the control unit 7 starts this processing procedure, it determines whether or not there is a toner replenishment request for any of the sub-hoppers 37Y, 37M, 37C, or 37K (step S130). If there is a toner replenishment request (YES in step S130), the control unit 7 identifies the toner bottle 40 to which the toner replenishment is to be made (step S131). The control unit 7 then detects the remaining toner amount of the identified toner bottle 40 (step S132) and determines whether or not the remaining toner amount of the toner bottle 40 is greater than a predetermined amount (step S133).

[0131] If the remaining toner amount is greater than a predetermined amount (YES in step S133), the control unit 7 sets the rotation speed of the motor identified as the target to be driven to the normal rotation speed V1 (step S134) and starts driving the motor (step S135). After that, the control unit 7 determines whether the toner replenishment operation is complete or not (step S136), and if it determines that the toner replenishment operation is complete (YES in step S136), it stops the motor (step S137).

[0132] Furthermore, if the remaining toner is below a predetermined amount (NO in step S133), the control unit 7 sets the rotation speed of the motor identified as the target to be driven to the normal rotation speed V1 (step S138) and starts driving the motor (step S139). Subsequently, the control unit 7 detects the rotation position of motor 50a or 50b (step S140) and determines whether or not the vibration applying unit 55 has reached the predetermined position just before applying vibration to the toner bottle 40 (step S141). If the rotation position of motor 50a or 50b has not reached the predetermined position (NO in step S141), the control unit 7 continues to drive motor 50a or 50b at the normal rotation speed V1. On the other hand, if the rotation position of motor 50a or 50b has reached the predetermined position (YES in step S141), the control unit 7 changes the rotation speed of motor 50a or 50b to a speed slower than the normal rotation speed V1 (step S142). As a result, when vibration is applied to the toner bottle 40 by the vibration-applying unit 55, the rotational speed of the motors 50a and 50b decreases.

[0133] Furthermore, when changing the rotation speed setting of motor 50a or 50b in step S142, a processing procedure similar to the second or third processing procedure described in the first embodiment may be adopted to change the motor's rotation speed to either V2 or V3. Alternatively, a processing procedure may be adopted in which the fourth processing procedure described in the first embodiment is applied to determine whether or not to change the motor's rotation speed to a rotation speed V2 or V3, which is lower than the normal rotation speed V1, depending on whether or not there are people around the image forming apparatus 1.

[0134] Subsequently, the control unit 7 determines whether the rotational position of the motor 50a or 50b has passed a predetermined position after vibration has been applied to the toner bottle 40 by the vibration application unit 55 (step S143). If it determines that the predetermined position has passed (step S143), it resets the rotational speed of the motor 50a or 50b to the normal rotational speed V1 (step S144).

[0135] The control unit 7 then determines whether the toner replenishment operation is complete (step S145). If it determines that the toner replenishment operation is complete (YES in step S145), it stops the motor (step S146). This concludes the processing procedure in the fifth embodiment.

[0136] As described above, the image forming apparatus 1 of this embodiment is configured to reduce the impact of vibrations applied to the toner bottle 40 and suppress the generation of vibration noise by reducing the rotational speed of the motors 50a and 50b just before vibrations are applied to the toner bottle 40 by the vibration application unit 55. Therefore, in this embodiment as well, it is possible to reduce the discomfort caused to people around the image forming apparatus 1.

[0137] In this embodiment, the configuration and operation other than those described above are the same as those described in any of the first to fourth embodiments.

[0138] (Sixth Embodiment) Next, a sixth embodiment of the present invention will be described. In this embodiment, an example will be described in which the image forming apparatus 1 is equipped with a sound detection sensor or a vibration detection sensor to detect the remaining amount of toner in the toner bottle 40.

[0139] Figure 20 is a perspective view showing the bottle mounting section 2d in the sixth embodiment. This bottle mounting section 2d has a support section 53 that supports the outer surface of the toner bottle 40, and a sound detection sensor 81 and a vibration detection sensor 82 are attached to it. Although Figure 20 shows an example in which both the sound detection sensor 81 and the vibration detection sensor 82 are attached, a configuration in which only one of them is attached is also acceptable.

[0140] The sound detection sensor 81 is a sensor that detects sound (sound pressure) generated around the support part 53. Therefore, the sound detection sensor 81 can detect the vibration sound when vibration is applied to the toner bottle 40 by the vibration application part 55. When the sound detection sensor 81 detects the vibration sound, it outputs a signal indicating the sound pressure level of that vibration sound to the control unit 7.

[0141] When the amount of toner remaining in the toner bottle 40 is greater than a predetermined amount, the sound pressure level detected by the sound detection sensor 81 becomes lower than a predetermined level. Conversely, when the amount of toner remaining in the toner bottle 40 is less than or equal to a predetermined amount, the sound pressure level detected by the sound detection sensor 81 becomes higher than a predetermined level. Therefore, the control unit 7 can detect the amount of toner remaining in the toner bottle 40 based on the signal output from the sound detection sensor 81.

[0142] The vibration detection sensor 82 is a sensor that detects the magnitude (intensity) of vibrations transmitted to the support part 53. Therefore, the sound detection sensor 81 can detect vibrations (impacts) when vibrations are applied to the toner bottle 40 by the vibration application unit 55. When the vibration detection sensor 82 detects vibrations in the support part 53, it outputs a signal indicating the magnitude of those vibrations to the control unit 7.

[0143] When the amount of toner remaining in the toner bottle 40 is greater than a predetermined amount, the vibration detected by the vibration detection sensor 82 becomes greater than a predetermined value. Conversely, when the amount of toner remaining in the toner bottle 40 is less than or equal to a predetermined amount, the vibration detected by the vibration detection sensor 82 becomes less than a predetermined value. Therefore, the control unit 7 can detect the amount of toner remaining in the toner bottle 40 based on the signal output from the vibration detection sensor 82.

[0144] Thus, the remaining toner detection unit 64 of the control unit 7 may be configured to detect the remaining toner in the toner bottle 40 based on a signal output from the sound detection sensor 81 or the vibration detection sensor 82. The other configurations and operations in this embodiment are the same as those described in any of the first to fifth embodiments.

[0145] (modified version) Preferred embodiments of the present invention have been described above. However, the present invention is not limited to those described in the above embodiments, and various modifications are applicable.

[0146] For example, in the above embodiment, a configuration example was described in which two motors 50a and 50b are provided as a drive source 50 for selectively rotating multiple toner bottles 40. However, the system is not limited to this, and for example, a configuration in which one motor is provided for each of the multiple toner bottles 40 may also be adopted. [Explanation of Symbols]

[0147] 1. Image forming apparatus 40 (40Y, 40M, 40C, 40K) Toner Bottles 50 Power source 50a, 50b motor 55 Vibration-applying section

Claims

1. An image forming apparatus capable of attaching a toner bottle, A drive source for rotating the toner bottle, A vibration-applying unit that applies vibration to the toner bottle as the toner bottle rotates, A remaining amount detection unit that detects the remaining amount of toner inside the toner bottle, A control unit that changes the vibration impact applied to the toner bottle by the vibration application unit while the toner bottle is rotating, based on the detection result of the remaining amount detection unit, Equipped with, The image forming apparatus is characterized in that, when the remaining amount detection unit detects that the remaining amount of toner is less than a predetermined amount, the control unit reduces the impact of vibrations applied to the toner bottle by the vibration application unit while the toner bottle is rotating.

2. The image forming apparatus according to claim 1, characterized in that the control unit changes the torque when the drive source rotates the toner bottle based on the detection result of the remaining amount detection unit.

3. The image forming apparatus according to claim 2, characterized in that the control unit changes the torque when the drive source rotates the toner bottle by changing the current supplied to the drive source.

4. The image forming apparatus according to claim 1, characterized in that the control unit drives the drive source with a first current when the remaining toner amount is detected by the remaining amount detection unit to be greater than a predetermined amount, and drives the drive source with a second current smaller than the first current when the remaining amount is detected by the remaining amount detection unit to be less than a predetermined amount.

5. The image forming apparatus according to claim 4, characterized in that the control unit detects the rotational position of the toner bottle by the drive source, and when the remaining amount detection unit detects that the remaining amount of toner is less than a predetermined amount, it changes the current supplied to the drive source from the first current to the second current before the rotational position of the toner bottle passes the position where vibration is applied to the toner bottle by the vibration application unit.

6. Environmental sensors that detect temperature and humidity, Furthermore, The image forming apparatus according to claim 4, characterized in that the control unit drives the drive source with a third current that is smaller than the first current and larger than the second current when the remaining amount of toner is detected by the remaining amount detection unit to be less than the predetermined amount, the temperature detected by the environmental sensor is lower than a predetermined temperature, and the humidity is lower than a predetermined humidity.

7. A toner adhesion detection unit that detects toner adhering to the inner wall of the toner bottle, Furthermore, The image forming apparatus according to claim 4, characterized in that the control unit drives the drive source with a third current that is smaller than the first current and larger than the second current when the remaining amount detection unit detects that the remaining amount of toner is less than a predetermined amount and the toner adhesion detection unit detects that toner is adhering to the inner wall of the toner bottle.

8. The image forming apparatus according to claim 7, wherein the toner adhesion detection unit is composed of a line sensor arranged along the longitudinal direction of the toner bottle, and detects toner adhering to the inner wall in the longitudinal direction of the toner bottle by detecting the reflected light of light irradiated onto the outer surface of the toner bottle.

9. The image forming apparatus according to claim 1, wherein the remaining amount detection unit has a sound detection unit that detects the sound produced when vibration is applied to the toner bottle by the vibration application unit, and the remaining amount of toner is detected based on the sound level detected by the sound detection unit.

10. The image forming apparatus according to claim 1, wherein the remaining amount detection unit has a vibration detection unit that detects vibration when vibration is applied to the toner bottle by the vibration application unit, and detects the remaining amount of toner based on the level of vibration detected by the vibration detection unit.

11. The image forming apparatus according to claim 1, characterized in that the remaining amount detection unit detects the remaining amount of toner based on the current flowing to the drive source when the drive source is started to operate.

12. The image forming apparatus according to claim 1, characterized in that the control unit changes the rotational speed at which the drive source rotates the toner bottle based on the detection result of the remaining amount detection unit.

13. The image forming apparatus according to claim 12, characterized in that the control unit changes the rotational speed at which the drive source rotates the toner bottle by changing the period of the current waveform supplied to the drive source.

14. The image forming apparatus according to claim 13, wherein the control unit drives the drive source at a first rotation speed when the remaining toner amount is detected by the remaining amount detection unit to be greater than a predetermined amount, and drives the drive source at a second rotation speed slower than the first rotation speed when the remaining amount is detected by the remaining amount detection unit to be less than a predetermined amount.

15. The image forming apparatus according to claim 14, characterized in that the control unit detects the rotational position of the toner bottle by the drive source, and when the remaining amount detection unit detects that the remaining amount of toner is less than a predetermined amount, it changes the rotational position of the toner bottle from the first rotational speed to the second rotational speed before the rotational position of the toner bottle passes the position where vibration is applied to the toner bottle by the vibration application unit.

16. A human detection unit that detects people around the device. Furthermore, The image forming apparatus according to claim 1, characterized in that when the person detection unit does not detect a person, the control unit does not change the impact of vibration applied to the toner bottle by the vibration application unit during the rotation of the toner bottle, regardless of the detection result of the remaining amount detection unit, and when the person detection unit detects a person, the control unit reduces the impact of vibration applied to the toner bottle by the vibration application unit during the rotation of the toner bottle when the remaining amount of toner is detected to be less than a predetermined amount.

17. The image forming apparatus according to claim 1, wherein the vibration-applying unit has a protrusion provided on the outer circumferential surface of the toner bottle and a recess provided on a support unit that supports the outer circumferential surface of the toner bottle, and vibration is applied to the toner bottle when the protrusion fits into the recess due to the rotation of the toner bottle.

18. The image forming apparatus according to claim 1, wherein the vibration-applying unit has a recess provided on the outer circumferential surface of the toner bottle and a protrusion provided on a support unit that supports the outer circumferential surface of the toner bottle, and vibration is applied to the toner bottle when the protrusion fits into the recess due to the rotation of the toner bottle.

19. It is possible to attach a toner bottle, A drive source for rotating the toner bottle, A vibration-applying unit that applies vibration to the toner bottle as the toner bottle rotates, A control method for an image forming apparatus, comprising: A remaining amount detection step for detecting the remaining amount of toner inside the toner bottle, A control step that changes the vibration impact applied to the toner bottle by the vibration applying unit while the toner bottle is rotating, based on the detection result of the remaining amount detection step, It has, The control step is characterized in that, when the remaining amount of toner is detected to be less than a predetermined amount by the remaining amount detection step, the vibration impact applied to the toner bottle by the vibration applying unit while the toner bottle is rotating is reduced.

20. It is possible to attach a toner bottle, A drive source for rotating the toner bottle, A vibration-applying unit that applies vibration to the toner bottle as the toner bottle rotates, A program that is executed in an image forming apparatus equipped with, The image forming apparatus, A remaining amount detection step for detecting the remaining amount of toner inside the toner bottle, A control step that changes the vibration impact applied to the toner bottle by the vibration applying unit while the toner bottle is rotating, based on the detection result of the remaining amount detection step, Make it run, The control step is a program characterized in that, when the remaining amount of toner is detected to be less than a predetermined amount by the remaining amount detection step, the vibration impact applied to the toner bottle by the vibration applying unit while the toner bottle is rotating is reduced.

Images