JP3673738B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus provided with a cleaning device for cleaning the surface of an image carrier in a printer, a copying machine, a facsimile, or the like.
[0002]
[Prior art]
2. Description of the Related Art A cleaning device in an image forming apparatus such as a printer, a copying machine, or a facsimile is known that has a cleaning blade as a cleaning member for cleaning an image carrier.
[0003]
For example, in an electrophotographic image forming apparatus, a toner image is formed on a photosensitive drum (image carrier) through image forming processes such as a charging process, an exposure process, and a developing process, and the toner image is exposed by a transfer process. It is transferred from the body drum onto a transfer material (for example, paper). In this transfer process, not all of the toner constituting the toner image on the photosensitive drum is transferred, and a small amount of toner remains on the surface of the photosensitive drum. The toner remaining on the surface of the photosensitive drum in this manner (hereinafter referred to as “residual toner”) is removed by the above-described cleaning blade.
[0004]
As shown in FIG. 12, the edge 61 a of the cleaning blade 61 is brought into contact with the surface of the photosensitive drum 11, thereby scraping off residual toner adhering to the surface of the photosensitive drum 11.
[0005]
[Problems to be solved by the invention]
However, the conventional example described above has the following problems.
[0006]
As shown in FIG. 12, residual toner scraped from the surface of the photosensitive drum 11 is aggregated in the vicinity of the edge 61 a of the cleaning blade 61 in contact with the photosensitive drum 11. Normally, the aggregated residual toner falls into a cleaning container (not shown) of the cleaning device with a certain size, so that there is no problem.
[0007]
However, depending on the influence of the increase in the peripheral speed (process speed) of the photosensitive drum 11 due to the recent increase in the speed of the image forming apparatus and the environmental conditions, the aggregated residual toner (hereinafter referred to as aggregated mass) does not drop and grows. It has been found that a phenomenon occurs in which the nip N of the edge 61a of the cleaning blade 61 passes through. The problem is that the residual toner slipped through in this way is transferred to the subsequent transfer material (sheet material) in the form of a streak during the next image formation, resulting in an image defect.
[0008]
As a means for improving the cleaning performance of the cleaning blade, there is a method of applying vibration by a piezoelectric element to the cleaning blade as proposed in Japanese Patent Laid-Open Nos. 6-4014 and 11-174922. However, in this method, since the piezoelectric element is attached to the cleaning blade that deteriorates due to durability, the piezoelectric element is also replaced at the same time when the deteriorated cleaning blade is replaced, resulting in an increase in cost. In addition, there is a drawback that it is difficult to give sufficient vibration to remove the aggregates that have agglomerated and grown. Further, the method of applying collision vibration to the cleaning blade as proposed in Japanese Patent Laid-Open No. 9-160455 may be able to give sufficient vibration to remove agglomerates, Depending on the behavior of the cleaning blade at the time of input, there may be adverse effects such as slipping of residual toner.
[0009]
Japanese Patent Laid-Open No. 2000-112187 discloses that when continuous image formation is greater than or equal to a predetermined number of sheets, the rotation of the photosensitive drum is temporarily stopped for each predetermined number of image formations so that the shape of the cleaning member is The shape of the nip portion between the photosensitive drum and the cleaning member changes due to a slight change during the stop from the rotation. As a result, there is also considered a method in which the rotation of the photosensitive drum is temporarily stopped to change the shape of the nip portion, whereby the toner fixed to the nip portion can be dropped from the nip portion. In this method, it is possible to remove the light agglomerates generated when the image is formed intermittently. However, it is difficult to completely remove the agglomerates that continue to grow in the continuous image formation.
[0010]
In addition, when image formation is performed continuously on both sides, the second surface image is formed on the transfer material once fixed by the fixing device. Rises. Therefore, when the image is continuously formed on both sides and left for a long time, the aggregate aggregated in the nip portion between the photosensitive drum and the cleaning blade is easily solidified due to the surface temperature of the photosensitive drum. This is because of the temperature characteristics of the toner.
[0011]
Accordingly, the present invention has been made in view of the above-described circumstances, and an image forming apparatus including a cleaning device that can satisfactorily remove residual toner on an image carrier without significant increase in cost. Is intended to provide.
[0012]
[Means for Solving the Problems]
In order to achieve the above object , a typical configuration of the present invention includes an image carrier, transfer means for transferring a toner image formed on the image carrier to a transfer material, and fixing the toner image to the transfer material. An image forming apparatus comprising: a fixing unit; a detecting unit that detects a temperature of the fixing unit; a cleaning blade that contacts the image carrier and removes transfer residual toner; and a vibration unit that vibrates the cleaning blade. In the above, when the power is turned on, it is determined whether to perform the vibration operation by the vibration unit according to the temperature detected by the fixing unit .
[0013]
In order to achieve the above object, another configuration of the present invention includes an image carrier, transfer means for transferring a toner image formed on the image carrier to a transfer material, and fixing the toner image to the transfer material. An image forming apparatus comprising: a fixing unit; a detecting unit that detects a temperature of the fixing unit; a cleaning blade that contacts the image carrier and removes transfer residual toner; and a vibration unit that vibrates the cleaning blade. In this case, when returning to a state in which image formation is possible, it is determined whether or not to perform the vibration operation by the vibration unit according to the temperature detected by the fixing unit .
[0014]
According to the above configuration, the residual toner aggregated in the vicinity of the contact portion between the image carrier and the cleaning blade can be satisfactorily removed without significant increase in cost.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, reference examples will be described first, and then embodiments according to the present invention will be described. Moreover, what attached | subjected the same code | symbol in each drawing has the same structure or effect | action, The duplication description about these was abbreviate | omitted suitably.
[0016]
[ First Reference Example ]
First, an image forming apparatus including a cleaning device according to a first reference example will be described in detail with reference to the drawings .
[0017]
[Image forming apparatus]
FIG. 1 shows an example of an image forming apparatus . The image forming apparatus shown in the figure is a laser beam printer, and the figure is a longitudinal section showing a schematic configuration thereof. Hereinafter , a case where the cleaning object to be cleaned by the cleaning device 17 (described later) is the photosensitive drum 11 will be described as an example.
[0018]
The laser beam printer (hereinafter referred to as “image forming apparatus”) shown in FIG. 1 includes a printer unit (image forming unit) 1 and a reader unit (image reading unit) 2.
[0019]
Among them, the printer unit 1 is provided with a drum-type electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 11 as an image carrier, and around the photosensitive drum 11, its rotating direction ( A primary charger (primary charging means) 12, an exposure device (exposure means) 13, a developing device (developing means) 14, a transfer charger 15, a separation charger 16, and a cleaning device (cleaning means) are sequentially arranged along the arrow direction. ) 17 is provided. Further, in the order from the upstream side along the conveying direction of the transfer material (for example, paper) P, the sheet feeding cassettes 18a and 18b, the sheet feeding rollers 19a and 19b, the registration rollers 20, the conveying belt 21, the fixing roller 22a, and the pressure roller. A fixing device (fixing means) 22 having 22b and a discharge roller 23 are disposed.
[0020]
On the other hand, the reader unit 2 is provided with a platen glass 31, a document pressing plate 32, a light source 33, reflection mirrors 34a, 34b, 34c, a lens 35, a CCD (photoelectric conversion element) 36, an image processing unit 37, and the like. .
[0021]
In the image forming apparatus having the above-described configuration, in the printer unit 1, the photosensitive drum 11 is rotationally driven in the direction of the arrow by a driving means (not shown) at a predetermined process speed (circumferential speed), here 480 mm / sec, and the surface thereof is The primary charger 12 is uniformly charged to a predetermined polarity and potential. On the other hand, in the reader unit 2, a document (not shown) placed on the platen glass 31 and pressed by the document pressing plate 32 is irradiated with the image surface (lower surface) by the light source 33, and the reflected light is reflected. The light is reflected by the mirrors 34 a, 34 b and 34 c, further passes through the lens 35, and is input to the CCD 36. The light thus input to the CCD 36 is subjected to various well-known image processing by the image processing unit 37, is converted into an electric signal 38, and is input to the exposure device 13 on the printer unit 1 side as image information.
[0022]
The laser scanner 13a of the exposure device 13 is modulated according to the image information, and exposes the surface of the photosensitive drum 11 after the above-described exposure via the reflection mirror 13b. By this exposure, an electrostatic latent image is formed on the surface of the photosensitive drum 11.
[0023]
This electrostatic latent image is developed by the developing device 14. A developer (toner) is stored in the developing device 14, and this toner is attached to the electrostatic latent image on the surface of the photosensitive drum 11 by applying a developing bias to the developing sleeve 14a, and the electrostatic latent image. The image is developed as a toner image.
[0024]
The toner image thus formed on the photosensitive drum 11 is transferred to the transfer material P. The transfer material P is fed from the paper feed cassette 18a or the paper feed cassette 18b by the paper feed roller 19a or the paper feed roller 19b. It is supplied to a transfer portion between the body drum 11 and the transfer charger 15. The toner image on the photosensitive drum 11 is transferred onto the transfer material P by applying a transfer bias to the transfer charger 15.
[0025]
The transfer material P after the toner image is transferred is separated from the surface of the photosensitive drum 11 by the separation charger 16 and is transported to the fixing device 22 by the transport belt 21, where it is heated and pressed by the fixing roller 22a and the pressure roller 22b. After the toner image is fixed on the surface, it is discharged out of the image forming apparatus main body by the discharge roller 23.
[0026]
On the other hand, after the toner image is transferred, the residual toner (adhered matter) remaining on the surface of the photosensitive drum 11 that is not transferred to the transfer material P at the time of transfer is removed by the cleaning device 17 and used for the next image formation. The cleaning device 17 will be described in detail later.
[0027]
In FIG. 1, two automatic document feeders 39 for automatically supplying a document on the platen glass 31 and automatically discharging the document from the platen glass 31 are provided above the document pressing plate 32. It is indicated by a dotted line.
[0028]
[Cleaning device]
Next, the cleaning device 17 will be described in detail with reference to FIG. FIG. 2 is a longitudinal sectional view of the cleaning device 17 in a direction perpendicular to the longitudinal direction (axial direction) of the photosensitive drum 11.
[0029]
The cleaning device 17 includes a frame (first frame) 41, a frame (second frame) 42, a cleaning blade (cleaning member) 43, a magnet roller 44, a conveying screw 45, a sheet 46, a holder 47, shafts 48 and 49, A tension spring (biasing means) 50 and a vibration means 51 are provided.
[0030]
Of these, the cleaning blade 43 is formed of a plate-like elastic body, and is held so as to be sandwiched between the frame 41 and the holder 47 by screwing the holder 47 to the frame 41. The cleaning blade 43 has one edge 43 a in contact with the surface of the photosensitive drum 11. The contact direction is the counter direction with respect to the movement direction (arrow direction) of the surface of the photosensitive drum 11. The contact surface 41a of the frame 41 with the back surface of the cleaning blade 43 and the contact surface 47a of the holder 47 with the end surface of the cleaning blade 43 are processed with high accuracy and are arranged with high positional accuracy. Therefore, the cleaning blade 43 can be realized with high positional accuracy with respect to the photosensitive drum 11 by being sandwiched by the holder 47 in a state where a part of the cleaning blade 43 is in contact with the contact surfaces 41a and 47a. Yes. The frame 41 holding the cleaning blade 43 also holds the vibration means 51.
[0031]
The frame 41 is swingably attached to the frame 42 via a shaft 48. Here, the photoconductor drum is configured to be swingable in the longitudinal direction, but may be configured not to swing in the longitudinal direction. One end of the tension spring 50 is connected to a part of the frame 42, and the other end is attached to a part of the frame 41. Therefore, the frame 41 is urged counterclockwise in the figure by the tension spring 50 around the shaft 48. Accordingly, the edge 43a of the cleaning blade 43 is in contact with the surface of the photosensitive drum 11 with an appropriate pressing force.
[0032]
The frame 42 extends downward on the side far from the photoconductive drum 11 and extends toward the photoconductive drum 11 at the bottom. The magnet roller 44 and the conveying screw 45 are rotatably supported by this portion of the frame 42. The magnet roller 44 and the conveying screw 45 are rotationally driven by driving means (not shown).
[0033]
The magnet roller 44 is disposed below the cleaning blade 43, and forms a toner layer of residual toner scraped off by the cleaning blade 43 on the surface thereof. The toner layer thickness is regulated by the sheet 46 and the shaft 49. The magnet roller 44 recoats the toner on the surface of the photosensitive drum 11 by bringing the toner layer into contact with the longitudinal direction of the photosensitive drum 11 (the direction along the generatrix). This is an adverse effect when the residual toner is scraped off by the cleaning blade 43 without recoating, that is, the frictional force between the cleaning blade 43 and the photosensitive drum 11 differs depending on whether the residual toner is present or not. This is to prevent the negative effect that unnecessary chatter (fine vibration) occurs. By recoating the residual toner in the longitudinal direction of the photosensitive drum 11 in this manner, the frictional force between the cleaning blade 43 and the photosensitive drum 11 can be stabilized in the longitudinal direction, and chattering of the cleaning blade 43 can be prevented. . The residual toner is scraped off by the cleaning blade 43 together with the recoated toner, and is collected by the magnet roller 44.
[0034]
The rotation direction of the magnet roller 44 is preferably forward with respect to the photoconductive drum 11 as shown in FIG. Is possible.
[0035]
The sheet 46 is in contact with the shaft 49. The sheet 46 is collected by the magnet roller 44 and has a function of sending excess residual toner to the conveying screw 45 to form a toner layer. The conveying screw 45 conveys residual toner to a toner collecting container (not shown).
[0036]
[Excitation means]
FIG. 4 shows the configuration of the vibration means 51 .
[0037]
The vibration means 51 includes a motor 52, a weight 53 attached to the output shaft 52a, and a case 54. The motor 52 is housed and fixed in the above-described case 54 in a state where it is connected to a control circuit 55 serving as control means. Further, the case 54 with the motor 52 fixed inside is fixed to the frame 41 as shown in FIG. Since the weight 53 is fixed with its center of gravity biased to one side with respect to the output shaft 52a, when the output shaft 52a of the motor 52 is rotationally driven by the control circuit 55, vibration is generated from the motor 52. This vibration propagates to the case 54 and the frame 41 and further to the cleaning blade 43. The case 54 has a function of preventing toner from entering the motor 52 and a function of efficiently transmitting vibration to the frame 41 by restraining the motor 52. The control circuit 55 is also connected to a drum motor 56 for driving the photosensitive drum 11 to rotate, and controls the rotation of the photosensitive drum 11.
[0038]
The vibration means 51 having the above-described configuration is not limited to the above-described configuration as long as it can apply sufficient vibration to the cleaning blade 43 to remove agglomerates.
[0039]
Further, even if one vibration means 51 is arranged at the center in the longitudinal direction of the frame 41 of the cleaning device 17, it is effective. However, in this case, the vibration is effectively propagated to the end of the cleaning blade 43. Requires a lot of vibration. For this reason, as shown in FIG. 5, by arranging a plurality of excitation means 51 at both ends in the longitudinal direction of the frame 41, vibration can be propagated to the cleaning blade 43 evenly with relatively small vibration. It becomes possible. In this case, the vibration means 51 is arranged at a position distributed to both ends with respect to the center L in the longitudinal direction of the frame 41 so that the variation in the contact pressure of the cleaning blade 43 to the photosensitive drum 11 is reduced. It is desirable to do so.
[0040]
Note that the cleaning performance of the above-described cleaning blade 43 gradually decreases due to wear associated with long-term use. Therefore, replacement is necessary at an appropriate time. Even at this time, with the configuration as described above, only the cleaning blade 43 can be easily replaced by simply removing the holder 47, and in addition to minimizing the cost of parts required for replacement and replacement man-hours. In addition, since the surface accuracy of the contact surface 41a of the frame 41 can guarantee the mounting surface accuracy of the cleaning blade 43, it is devised to increase stability. In order to increase the reproducibility of the behavior of the cleaning blade 43 when vibration is input by the vibration means 51, it is important that the mounting state is stable.
[0041]
[Blade edge]
FIGS. 3A, 3B, 3C, and 3D are enlarged views of the contact portion (nip) N between the surface of the photosensitive drum 11 and the edge 43a of the cleaning blade 43. FIG.
[0042]
As shown in FIG. 3A, residual toner scraped off from the surface of the photosensitive drum 11 is aggregated at the edge 43 a of the cleaning blade 43 that is in contact with the photosensitive drum 11. As shown in FIG. 3B, when the aggregated residual toner continues to grow, the toner passes through the nip N between the edge 43a of the cleaning blade 43 and the surface of the photosensitive drum 11, and the toner adheres to the transfer material P. As a result, the image may be defective. For this reason, it is necessary to remove the residual toner that has grown into aggregates from the edge 43 a of the cleaning blade 43.
[0043]
Therefore, when the vibration means 51 (see FIG. 2) is operated and vibration is propagated to the cleaning blade 43 through the frame 41 (FIG. 3C), an image defect occurs from the edge 43a of the cleaning blade 43. The residual toner aggregates are removed before the process (FIG. 3D). By the way, when the vibration means 51 is operated, the vibration propagates to the photosensitive drum 11 via the cleaning blade 43, and therefore it is not desirable to perform it during image formation. When the vibrating means 51 is operated while the photosensitive drum 11 is rotating, the edge 43a of the cleaning blade 43 is partially separated from the photosensitive drum 11 due to vibration, so that the transfer residual toner on the photosensitive drum 11 is removed from the cleaning blade. 43 slips out of the image and an image defect occurs. Therefore, the timing for operating the vibration means 51 needs to be when the photosensitive drum 11 is completely stopped.
[0044]
When the image forming apparatus shifts from the operation to the stop stage, the photosensitive drum 11 rotates for a while due to inertia until the photosensitive drum 11 is completely stopped. Accordingly, a predetermined time is required from the time when the signal for stopping the photosensitive drum 11 is issued to the time when the photosensitive drum 11 is completely stopped.
[0045]
Therefore, here, the operation timing of the vibration means 51 is shown below.
[0046]
[sequence]
(1) Fixing Device Here, the fixing device will be described. In FIG. 6, 22a is a fixing roller, 22a1 is a heating means, 22b is a pressure roller, and 22b1 is a metal core. Reference numeral 22c denotes temperature detecting means for detecting the surface temperature of the fixing roller. Here, the fixing device having the configuration shown in FIG. 6 is illustrated, but the present invention is not limited to this. For example, a fixing device having heating means for the fixing roller and the pressure roller, and film fixing using a film. device, a fixing device having another temperature sensing means such as an electromagnetic induction heating fixing device having the same effect.
[0047]
Further, the temperature detecting means is not limited to the surface temperature of the fixing roller, and detects the temperature related to other fixing devices such as the surface temperature of the pressure roller, the surface temperature of the film fixing device, the surface temperature near the heater, and the film surface temperature. There is no problem.
[0048]
(2) Judgment of operation of vibration means The method for judging whether or not the vibration means 51 is to be operated will be described. First, the temperature detected by the temperature detecting means 22c, here, the surface temperature of the fixing roller 22a is detected. When the detected temperature is equal to or lower than the predetermined temperature t1, normally, the fixing roller 22a is heated by the heating unit 22a1 until reaching a temperature at which image formation is possible. Further, when heating is performed, a heating method in which heating is initially performed in a stopped state and then pre-multi-rotation is performed after reaching a predetermined temperature t2 is usual. Here, the surface temperature of the fixing roller 22a is 190 ° C. during image formation, the predetermined temperature t1 is 180 ° C., and the predetermined temperature t2 is 170 ° C.
[0049]
Even if the temperature is different from the temperature exemplified above, the operation determination method of the vibration means 51 is the same.
[0050]
(3) Timing of operation of the vibration means (3-1) When the vibration means operates after the previous multi-rotation A sequence when the vibration means 51 operates after the previous multi-rotation will be described below.
[0051]
It is assumed that at least when the fixing roller 22a and the pressure roller 22b start to rotate when the temperature detection means 22c of the fixing device 22 reaches a predetermined temperature, at least the photosensitive drum 11 is rotated (hereinafter, the former many) Called rotation). In that case, the timing at which the fixing roller 22a and the like and the photosensitive drum 11 start to rotate does not necessarily have to be the same. Here, the predetermined temperature is 170 ° C.
[0052]
As shown in the flowchart of FIG. 7 and the timing chart of FIG. 8, energization to the drum motor is stopped after a drum signal for stopping the drum is generated while the drum is rotating. For this reason, the photosensitive drum 11 is stopped, but the rotation due to the inertia of the photosensitive drum 11 remains, so that the photosensitive drum 11 is stopped after a predetermined time A from the absence of energization. The value of the predetermined time A is about 0.5 second to about 2 seconds, although it cannot be generally stated because it is affected by the torque of the photosensitive drum 11 and the process speed. Of course, it is possible to adopt other values without affecting the effect or the like.
[0053]
Therefore, in consideration of the rotation due to the inertia of the photosensitive drum 11, the photosensitive drum 51 is operated by performing the operation of the vibration means 51 after B seconds (predetermined timing) from the time when the drum signal is turned from ON to OFF. 11, the vibration means 51 can be operated.
[0054]
In addition, C second in FIG. 8 is the operation time of the vibration means 51, and the value is arbitrary. Here, the operation is performed for about 0.7 seconds.
[0055]
Here, the value of B seconds, which is the predetermined timing after the photosensitive drum 11 is stopped, at which the vibration means 51 operates, can be, for example, (A seconds + 0.1 seconds to around 1 second). Here, which value from 0.1 second to 1 second is different depending on the model. Of course, it is possible to adopt a value higher than that without affecting the effect.
[0056]
D seconds is the time between operations when the vibration means 51 is operated. The value of D is arbitrary, and is set to about 1 second here , for example. In addition, if this time is D seconds> 0 seconds, there is no effect regardless of which value is adopted.
[0057]
(3-2) When the vibration means operates before the previous multi-rotation A sequence when the vibration means 51 operates before the previous multi-rotation will be described below.
[0058]
In the case of this sequence, the vibration means 51 is operated before the pre-multi-rotation, and as the operation timing, the temperature detected by the temperature detection means 22c reaches a predetermined temperature, for example, 150 ° C. When it is time. In this sequence, the operation timing is the temperature of the fixing device. However, even if the operation is performed at a predetermined timing using other signals, the effect of the operation of the vibration means 51 is not affected.
[0059]
As shown in the timing chart of FIG. 9, the photosensitive drum 11 is stopped until the temperature by the temperature detection unit 22 c of the fixing device 22 reaches 150 ° C. Thereafter, after the temperature by the temperature detection means 22c reaches 150 ° C., the vibration means 51 operates after E seconds. Although the value of E is not a problem even if the vibration means 51 is operated at the same time as the temperature reaches 150 ° C., the value of E is an arbitrary value of 0 seconds or more and there is no problem. Here, for example, about 0.5 seconds.
[0060]
In addition, C second in FIG. 9 is the operation time of the vibration means 51, and the value is arbitrary. Here, the operation is performed for about 0.7 seconds.
[0061]
D seconds is the time between operations when the vibration means 51 is operated. The value of D is arbitrary, and is set to about 1 second here , for example. In addition, if this time is D seconds> 0 seconds, there is no effect regardless of which value is adopted.
[0062]
At least when the fixing roller 22a and the pressure roller 22b start to rotate when the temperature detecting means 22c of the fixing device 22 reaches a predetermined temperature after the vibration means 51 is operated, at least the photosensitive drum 11 is used. Rotates before and after. In that case, the timing at which the fixing roller 22a and the like and the photosensitive drum 11 start to rotate does not necessarily have to be the same. Here, the predetermined temperature is 170 ° C.
[0063]
According to the above configuration , the cleaning blade 43 can be vibrated enough to remove the deposits, and the slipping of the deposits when vibration is input to the cleaning blade 43 can be prevented. The deposits on the photosensitive drum 11 can be removed satisfactorily without increasing the cost.
[0064]
[ Second Reference Example ]
Next, an image forming apparatus including the cleaning device according to the second reference example will be described in detail. Here, when the vibration means 51 operates a plurality of times, a case where each operation time is different is shown. The schematic configuration of the image forming apparatus, the cleaning apparatus, and the vibration means is the same as that of the first reference example described above.
[0065]
[Operation timing of vibration means]
In the second reference example , the case where the vibration means operates after the previous multi-rotation is shown, but even when the vibration means operates before the previous multi-rotation, the configuration of the second reference example is the same as the first reference example described above. Shall hold.
[0066]
It is assumed that at least when the fixing roller 22a and the pressure roller 22b start to rotate when the temperature detection means 22c of the fixing device 22 reaches a predetermined temperature, at least the photosensitive drum 11 is rotated (hereinafter, the former many) Called rotation). In that case, the timing at which the fixing roller 22a and the like and the photosensitive drum 11 start to rotate does not necessarily have to be the same. Here, the predetermined temperature is 170 ° C.
[0067]
As shown in the timing chart of FIG. 10, energization to the drum motor is stopped after a drum signal for stopping the drum is generated while the drum is rotating. For this reason, the photosensitive drum 11 is stopped, but the rotation due to the inertia of the photosensitive drum 11 remains, so that the photosensitive drum 11 is stopped after a predetermined time A from the absence of energization. The value of the predetermined time A is about 0.5 second to about 2 seconds, although it cannot be generally stated because it is affected by the torque of the photosensitive drum 11 and the process speed. Of course, it is possible to adopt other values without affecting the effect or the like.
[0068]
Therefore, in consideration of the rotation due to the inertia of the photosensitive drum 11, the photosensitive drum 51 is operated by performing the operation of the vibration means 51 after B seconds (predetermined timing) from the time when the drum signal is turned from ON to OFF. 11, the vibration means 51 can be operated.
[0069]
In addition, C1-C3 second in FIG. 10 is each operation time of the vibration means 51, The value is arbitrary. Here, C1 is operated for about 0.7 seconds, C2 is operated for about 0.8 seconds, and C3 is operated for about 0.9 seconds.
[0070]
Each operation time can be arbitrarily set in consideration of the operation of the image forming apparatus or the like.
[0071]
Here, the value of B seconds, which is the predetermined timing after the photosensitive drum 11 is stopped, at which the vibration means 51 operates, can be, for example, (A seconds + 0.1 seconds to around 1 second). Here, which value from 0.1 second to 1 second is different depending on the model. Of course, it is possible to adopt a value higher than that without affecting the effect.
[0072]
D seconds is the time between operations when the vibration means 51 is operated. The value of D is arbitrary, and is set to about 1 second here , for example. In addition, if this time is D seconds> 0 seconds, there is no effect regardless of which value is adopted.
[0073]
Here, only the case where the vibration means 51 operates a plurality of times at a predetermined timing before each rotation of the photosensitive drum 11 and the respective operation times are different has been described. However, the present invention is not limited to this. As in the first reference example described above, after the pre-multiple rotation of the photosensitive drum 11, as described above, the vibration means 51 operates a plurality of times at a predetermined timing, and the operation times thereof differ. Similar effects can be obtained.
[0074]
According to the above configuration , the cleaning blade 43 can be vibrated enough to remove the deposits, and the slipping of the deposits when vibration is input to the cleaning blade 43 can be prevented. The deposits on the photosensitive drum 11 can be removed satisfactorily without increasing the cost.
[0075]
[ First Embodiment ]
Next, an image forming apparatus including the cleaning device according to the first embodiment of the present invention will be described in detail. In the present embodiment, the number of times that the vibration means 51 operates is determined according to the temperature detected by the temperature detection means 22c of the fixing device 22, and the number of times determined after the previous multi-rotation or before the pre-multi-rotation is determined. The vibration means 51 operates. The schematic configurations of the image forming apparatus, the cleaning apparatus, and the vibration means are the same as those in the reference example described above.
[0076]
[Determination of the number of operations of the vibration means]
FIG. 11 shows a flowchart for determining the number of times the vibration means 51 operates.
[0077]
First, the temperature of the temperature detection means 22c of the fixing device 22 is detected at a predetermined timing. The predetermined timing is, for example, when the power is turned on, when returning from the standby state, when returning after a paper jam occurs in the transport unit or when returning after an error occurs. When the temperature of the fixing device 22 is detected at such a predetermined timing, when the temperature is 100 ° C. or lower, the number of operations of the vibration means 51 is five, and when the temperature is 100 ° C. to 150 ° C., the vibration means 51 The number of operations is 3 times, and when the temperature is 150 ° C. to 190 ° C., the number of operations of the vibration means 51 is 1 time, and when the temperature is 190 ° C. or more, 0 times. Further, the temperature at the time of image formation of the fixing device 22 is 200 ° C. in this embodiment. After the determined number of times, the vibration means 51 is operated, an image can be formed. Note that the temperature and number of times are just an example, and of course, the effect does not change even if another temperature and number of times are set.
[0078]
[Operation timing of vibration means]
In this embodiment, the sequence in which the vibration means 51 operates for the determined number of times is the vibration means before or after the previous multi-rotation, as shown in the first reference example or the second reference example described above. It is assumed that the configuration of the present embodiment is established in the same manner as when is operated.
[0079]
According to the present embodiment, it is possible to reduce the number of operations of the vibration means 51, which enables the vibration means 51 to be used for a long period of time.
[0080]
[Other Embodiments]
In the above-described embodiment, the image forming apparatus capable of forming a monochrome image has been described as an example. However, the present invention is not limited thereto, and the present invention is applicable to a cleaning device for an image forming apparatus capable of forming a color image. The same effect can be obtained even if is applied.
[0081]
In the above-described embodiment, the copying machine is exemplified as the image forming apparatus. However, the present invention is not limited to this. For example, other images such as a printer, a facsimile machine, or a multifunction machine combining these functions may be used. Forming on an image forming apparatus and an image carrier using a transfer device as a transfer material carrier and a transfer material belt as a transfer material carrier, and sequentially transferring toner images of respective colors onto a transfer material such as a sheet carried on the transfer material belt The image forming apparatus may be configured to temporarily transfer and carry the toner image to the intermediate transfer member, and transfer the toner images carried on the intermediate transfer member to the transfer material in a lump. The same effect can be obtained by applying the present invention to this cleaning apparatus.
[0082]
In the above-described embodiment, the object to be cleaned is exemplified by an image carrier (photosensitive drum) that is a rotating body in the image forming apparatus, and the present invention is applied to a cleaning apparatus that removes deposits on the photosensitive drum. However, the present invention is not limited to this. For example, the present invention is applied to a cleaning device that removes deposits of other objects to be cleaned such as the transfer material carrier and the intermediate transfer body. However, the same effect can be obtained.
[0083]
【The invention's effect】
As described above, according to the present invention, without large cost, it is possible to shake off the residual toner aggregated contact portion vicinity of the image bearing member and the cleaning blade, the residual toner cleaning It is possible to prevent poor cleaning such as slipping through the blade . Particularly, agglomerated residual toner that is difficult to remove when the image forming apparatus is left for a long period of time can be efficiently removed, and defective cleaning such as the residual toner slipping through the cleaning blade can be more effectively prevented.
[0084]
In addition, according to the present invention, it is possible to effectively prevent an image defect such that the transfer material is contaminated due to a cleaning defect.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of an image forming apparatus according to the present invention.
FIG. 2 is a longitudinal sectional view showing a schematic configuration of a cleaning device according to the present invention.
FIGS. 3A to 3D are enlarged views illustrating how toner aggregated in the vicinity of the edge of the cleaning blade is removed by vibration. FIGS.
FIG. 4 is a perspective view of a motor and a case constituting a vibration means.
FIG. 5 is a perspective view showing a state in which two vibration means are attached to a frame.
FIG. 6 is a cross-sectional view of a fixing device according to a first reference example .
FIG. 7 is a flowchart regarding pre-multi-rotation of the first reference example .
FIG. 8 is a sequence after multiple pre-rotations in the first reference example .
FIG. 9 is a sequence before the pre-multiple rotation in the first reference example .
FIG. 10 is a sequence after the previous multi-rotation in the second reference example .
FIG. 11 is a flowchart for determining the number of times of vibration means in the first embodiment .
FIG. 12 is an enlarged view showing that toner aggregates in the vicinity of the edge of a conventional cleaning blade.
[Explanation of symbols]
L ... center N ... nip P ... transfer material 1 ... printer unit 2 ... reader unit 11 ... photoconductor drum 12 ... primary charger 13 ... exposure device 13a ... laser scanner 13b ... reflection mirror 14 ... developer 14a ... developing sleeve 15 ... Transfer charger 16 ... Separation charger 17 ... Cleaning devices 18a and 18b ... Paper feed cassettes 19a and 19b ... Paper feed roller 20 ... Registration roller 21 ... Conveyor belt 22 ... Fixing device 22a ... Fixing roller 22a1 ... Heating means 22b ... Pressure Roller 22b1 ... Core metal 22c ... Temperature detection means 23 ... Discharge roller 31 ... Platen glass 32 ... Document pressing plate 33 ... Light sources 34a, 34b, 34c ... Reflection mirror 35 ... Lens 36 ... CCD
37 ... Image processing unit 39 ... Automatic document feeder 41 ... Frame 41a ... Contact surface 42 ... Frame 43 ... Cleaning blade 43a ... Edge 44 ... Magnet roller 45 ... Conveying screw 46 ... Sheet 47 ... Holder 47a ... Contact surfaces 48, 49 ... Shaft 50 ... tension spring 51 ... vibration means 52 ... motor 52a ... output shaft 53 ... weight 54 ... case 55 ... control circuit

Claims (4)

An image carrier, a transfer unit that transfers a toner image formed on the image carrier to a transfer material, a fixing unit that fixes the toner image to the transfer material, and a detection unit that detects the temperature of the fixing unit; In an image forming apparatus comprising: a cleaning blade that contacts the image carrier to remove transfer residual toner; and a vibration unit that vibrates the cleaning blade.
2. An image forming apparatus according to claim 1, wherein when the power is turned on, whether or not to perform the vibration operation by the vibration unit is determined according to a temperature detected by the fixing unit . An image carrier, a transfer unit that transfers a toner image formed on the image carrier to a transfer material, a fixing unit that fixes the toner image to the transfer material, and a detection unit that detects the temperature of the fixing unit; In an image forming apparatus comprising: a cleaning blade that contacts the image carrier to remove transfer residual toner; and a vibration unit that vibrates the cleaning blade.
An image forming apparatus, wherein when returning to an image formable state, whether or not to perform a vibration operation by the vibration unit is determined according to a temperature detected by the fixing unit . The image forming apparatus according to claim 1, wherein the vibration unit vibrates the cleaning blade in a direction away from the image carrier . The image forming apparatus according to claim 1, wherein the number of vibration operations is changed according to a temperature detected by the fixing unit .

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