JP2011028161A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of removing toner deposited on an image carrier side end part of a shielding plate disposed on the lower edge part of an opening formed on a casing of a cleaning means. <P>SOLUTION: The image forming apparatus includes: a cleaning means including a brush roller pivotally supported rotatably in a casing so as to come into contact with the surface of the image carrier by exposing a portion of the brush roller from an opening of the casing, and the shielding plate made of an elastic member which is disposed on the lower edge part of the opening and shields an aperture formed between the casing and the image carrier; and a brush roller rotation-driving means which rotates and drives the brush roller. The image forming apparatus further includes: an attaching and detaching means which attaches and detaches the image carrier lateral end part of the shielding plate for the brush roller; and a controlling means which causes the image carrier lateral end part of the shielding plate to contact with the brush roller by means of the attaching and detaching means, rotates and drives the brush roller by means of the brush roller rotation-driving means and performs such a control as to clean the shielding plate by means of the brush roller. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.

  In this type of image forming apparatus, a latent image is formed on a uniformly charged photoreceptor, and the latent image is developed with toner by a developing device to be visualized. The toner image on the photosensitive member is transferred onto the transfer paper by the transfer device, and the toner image transferred onto the transfer paper is fixed on the transfer paper by being heated and pressurized by the fixing device. Further, untransferred toner remaining on the photosensitive member without being transferred from the photosensitive member to the transfer paper is cleaned by a cleaning device that cleans the surface of the photosensitive member.

  In the cleaning device provided in the image forming apparatus described in Patent Document 1, an opening is formed in the casing toward the surface of the photosensitive member, and a part of the opening is exposed to contact the surface of the photosensitive member and enter the casing. A brush roller rotatably supported is provided. In addition, a cleaning blade having one end fixed to the upper edge of the opening and the other end in contact with the surface of the photoreceptor is provided. An elastic member that shields a gap formed between the lower end edge of the casing and the photoconductor, with one end fixed to the lower end edge and the other end in contact with the photoconductor surface at the lower end edge of the opening The shielding board which consists of is provided. Then, as shown in FIG. 9, the transfer residual toner 5a on the photosensitive member 4 rotating in the arrow A1 direction in the drawing is scraped off from the photosensitive member 4 when the brush roller 2 first rotates in the arrow B1 direction in the drawing. . Next, the surface of the photoconductor 4 is scraped off by the cleaning blade 3 disposed downstream of the brush roller 2 in the photoconductor rotation direction. The shielding plate 6 prevents the toner scraped off from the photosensitive member 4 by the brush roller 2 and the cleaning blade 3 from leaking out of the cleaning case 15 from between the lower end edge of the cleaning case 15 and the photosensitive member 4. ing.

  The toner scraped off from the surface of the photosensitive member by the brush roller 2 or the cleaning blade 3 is sandwiched between the end of the shielding plate 6 on the photosensitive member side and the brush roller 2 and is deposited on the end of the shielding plate 6 on the photosensitive member side. There is. Therefore, when the cleaning device 1 is removed from the image forming apparatus main body during maintenance or the like, the toner accumulated on the end portion of the shielding plate 6 falls out of the cleaning case 15 of the cleaning device, and the inside of the image forming apparatus, There arises a problem that the operator's hands and clothes, or the floor around the image forming apparatus main body is soiled.

  The present invention has been made in view of the above problems, and an object of the present invention is to remove toner deposited on the image carrier side end of the shielding plate provided at the lower end edge of the opening formed in the casing of the cleaning means. An object of the present invention is to provide an image forming apparatus that can be removed.

In order to achieve the above object, an invention according to claim 1 is directed to an image carrier that is rotatably supported, a latent image forming unit that forms a latent image on the image carrier, and an image carrier on the image carrier. Developing means for developing the formed latent image with toner, transfer means for transferring the toner image on the image carrier onto a recording medium, a casing having an opening toward the surface of the image carrier, and the opening A brush roller rotatably supported in the casing so as to be partly exposed and contact the surface of the image carrier, and between the casing and the image carrier provided at the lower edge of the opening. In an image forming apparatus comprising: a cleaning unit having a shielding plate made of an elastic member that shields a gap formed on the brush member; and a brush roller rotation driving unit that rotationally drives the brush roller. The image carrier side end of the shielding plate The image carrier side end of the shielding plate is brought into contact with the brush roller by the contact / separation means to be separated, the brush roller is rotationally driven by the brush roller rotation driving means, and the brush roller rotates the brush roller. And control means for performing control for cleaning the shielding plate.
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the contact / separation means displaces the cleaning means relative to the image carrier and presses the shielding plate against the image carrier. The shielding plate is curved, and the image carrier side end of the shielding plate is brought into contact with a brush roller.
According to a third aspect of the present invention, in the image forming apparatus of the second aspect, the rotation direction of the image carrier is a normal rotation direction that is a rotation direction during an image forming operation, and a reverse rotation direction to the normal rotation direction. An image carrier rotation driving means capable of rotationally driving the image carrier, and the image carrier in the casing of the cleaning means is located downstream of the brush roller in the normal rotation direction of the image carrier. A cleaning blade that comes into contact with the image carrier at a pressure capable of scraping off deposits such as toner remaining on the surface of the image carrier, and the control means is configured to increase the contact pressure of the cleaning blade with respect to the image carrier. At the end of the image forming operation, the cleaning unit is displaced with respect to the image carrier so that the thickness is reduced from the steady pressure that is the contact pressure during the image forming operation. The rotary drive means is characterized in performing control to rotate the image carrier in the reverse rotational direction.
According to a fourth aspect of the present invention, in the image forming apparatus according to the first, second, or third aspect, the toner attached to the brush roller is disposed in the casing of the cleaning unit in contact with the brush roller. The brush roller rotation driving means has a scraping member that scrapes off the brush roller, and the brush roller rotation driving means has a rotation direction of the brush roller that is a rotation direction during an image forming operation and a rotation direction opposite to the normal rotation direction. The brush roller can be driven to rotate in the reverse direction, and the control means drives the brush roller in the reverse rotation direction by the brush roller rotation driving means when performing control for cleaning the shielding plate. It is characterized by performing control.
According to a fifth aspect of the present invention, in the image forming apparatus according to the first, second, third, or fourth aspect, the image forming apparatus further includes a cumulative rotation number counting unit that counts a cumulative rotation number of the brush roller. In accordance with the cumulative number of rotations of the brush roller, the control means controls the rotation driving time of the brush roller when performing control for cleaning the shielding plate.
According to a sixth aspect of the present invention, in the image forming apparatus according to the first, second, third, fourth, or fifth aspect, the image forming apparatus further comprises a temperature / humidity detecting unit that detects a temperature and humidity in the main body of the image forming apparatus. The period for performing the control for cleaning the shielding plate is varied in accordance with the temperature and humidity in the image forming apparatus main body detected by the above.
According to a seventh aspect of the present invention, in the image forming apparatus of the first, second, third, fourth, fifth or sixth aspect, the image area ratio detecting means for detecting the image area ratio of the latent image formed on the image carrier. And the period for performing the control for cleaning the shielding plate is varied in accordance with the image area ratio detected by the image area ratio detection means.
The invention according to claim 8 is the image forming apparatus according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the image carrier is a drum-shaped photoconductor using amorphous silicon. It is characterized by.
According to a ninth aspect of the present invention, there is provided the image forming apparatus according to the first, second, third, fourth, fifth, sixth or seventh aspect, wherein the image carrier has a drum shape containing inorganic particles at least in the outermost surface layer. It is a photosensitive member of the above.

  In the present invention, the image carrier side end of the shielding plate is brought into contact with the brush roller by the contact / separation means, and the toner deposited on the end of the shielding plate is removed from the shielding plate by the rotationally driven brush roller. As a result, when the cleaning unit is removed from the image forming apparatus main body, the toner accumulated on the end portion of the shielding plate falls outside the casing of the cleaning unit, and the inside of the image forming apparatus main body, the operator's Contamination of hands, clothes, or the floor around the image forming apparatus main body can be suppressed.

  As described above, according to the present invention, there is an excellent effect that the toner accumulated on the image carrier side end portion of the shielding plate provided at the lower end edge portion of the opening formed in the casing of the cleaning unit can be removed. .

1 is a schematic configuration diagram of a cleaning device according to an embodiment. 1 is a schematic diagram of an image forming apparatus according to an embodiment. The perspective view of a cleaning unit. The top view of a cleaning unit. The schematic diagram of a cleaning apparatus. FIG. 6 is an explanatory diagram when the cleaning device is rotated from a position at the time of image forming operation to a position at the time of reversal operation of the photosensitive member and the brush roller. FIG. 4 is an explanatory diagram when the cleaning device is rotated from a position during the reversal operation of the photosensitive member and the brush roller to a position during the image forming operation. The flowchart which shows an example of a series of control concerning this embodiment. Schematic of the conventional cleaning apparatus.

Hereinafter, embodiments of the present invention will be described based on the illustrated examples.
FIG. 2 is a schematic diagram showing an image forming apparatus for explaining an embodiment of the present invention. In the image forming apparatus shown in FIG. 2, a cleaning blade 3 is brought into contact with a latent image carrier to form toner or paper. A cleaning device 1 capable of scraping off foreign matters such as powder is provided.

  The image forming apparatus shown in FIG. 1 is a laser beam printer capable of optical writing corresponding to image information. However, the image forming apparatus can be applied not only to the above-described printer but also to a copying machine or a facsimile apparatus.

  As shown in FIG. 2, the image forming apparatus of the present embodiment includes a drum-shaped photoconductor 4 that is a latent image carrier, and image formation performed by rotating the photoconductor 4 around the photoconductor 4. A charging device 7, a writing device 8, a developing device 9, a transfer device 10, and a charge eliminating device 11 are arranged for executing image forming processing during operation.

  The writing device 8 emits laser light to the photosensitive member 4 to expose the surface of the photosensitive member to form an electrostatic latent image on the surface of the photosensitive member. Therefore, it is possible to detect the printing density by detecting the light emission of the laser. The photoreceptor 4 has a structure in which amorphous silicon has a high surface hardness and little wear, or an outermost surface layer contains inorganic particles, and an organic photosensitive layer composed of a charge generation layer and a charge transport layer is formed on a conductive group such as aluminum. It is formed by coating.

  The surface of the photoreceptor 4 that is rotationally driven during the image forming operation is uniformly charged by the charging device 7, and an electrostatic latent image is formed on the surface of the photoreceptor charged by optical writing according to the image information by the writing device 8. Then, the electrostatic latent image is subjected to visible image processing with toner supplied from the developing device 9 to form a toner image on the surface of the photoreceptor. The toner image on the photoreceptor 4 is electrostatically transferred to the transfer paper 12 fed from a paper supply device (not shown) via the transfer device 10, and then the transfer paper 12 on which the toner image is transferred is fixed (not shown). Then, the toner image is fixed on the transfer paper 12 by the fixing device and discharged onto a paper discharge tray (not shown).

  The surface of the photoconductor 4 after transfer faces the cleaning device 1, so that residues such as toner, paper dust and various additives remaining on the photoconductor surface after transfer are removed from the surface of the photoconductor by the cleaning device 1. Removed. After the surface of the photoconductor is cleaned by the cleaning device 1, the residual charge on the surface of the photoconductor is removed by the static eliminator 11, and uniform charging is performed by the charging device 7 to prepare for another image forming process.

  FIG. 1 is a schematic cross-sectional configuration diagram of a cleaning unit 40 according to the present embodiment, FIG. 3 is a perspective view of the cleaning unit 40, and FIG. 4 is a top view of the cleaning unit 40. The cleaning case 15 of the cleaning device 1 is detachably incorporated in the bracket 31 of the cam mechanism portion 30, and the cleaning device 1 and the cam mechanism portion 30 can be collectively attached to and detached from the image forming apparatus as a cleaning unit 40. It is configured as follows. The cleaning unit 40 is provided at the lower part of a support frame 41 that supports the cleaning device 1, the cam mechanism 30, and the like. It is supported in a rotatable state with respect to the main body. In a state where the cleaning unit 40 is mounted on the image forming apparatus main body, the cleaning unit 40 is rotated about 45 °, for example, in a direction away from the photosensitive member 4 (front side of the sheet) with the cylindrical protrusion 43 as a rotation axis. Thus, the cam mechanism 30, in other words, the cleaning device 1 can be attached to and detached from the cleaning unit 40. As described above, the cleaning unit 40 is supported by the main body of the image forming apparatus around the cylindrical protrusion 43. Similarly, a bearing portion (not shown) of the photosensitive member 4 is also rotatably supported by the main body of the image forming apparatus. Is done. For this reason, the photoreceptor 4 and the brush roller 2 in the cleaning unit 40 maintain the fixed positional relationship shown in FIG.

  The cleaning device 1 includes a brush roller 2, a cleaning blade 3, a shielding plate 6, a cleaning case 15, a toner discharge member 16, a flicker 25, and the like.

  The cleaning blade 3 is made of an elastic material such as rubber, and the base end portion of the cleaning blade 3 is fixedly supported by the cleaning case 15, and the front end edge portion on the free end side opposite to the base end portion side. Is in pressure contact with the surface of the photoreceptor 4.

  The brush roller 2 is provided upstream of the cleaning blade 3 on the upstream side in the normal photoconductor rotation direction during an image forming operation indicated by an arrow A1 in the drawing, and is configured by a rigid core shaft 17 and a brush 18 made of a hair. In the cleaning case 15. Further, the core shaft 17 is rotatably supported on the side wall of the cleaning case 15, and the entire brush roller 2 is rotationally driven around its central axis. The normal rotation direction of the brush roller 2 may be the clockwise direction in the figure or the counterclockwise direction in the figure, but in the example shown in FIG. 1, as indicated by the arrow B1 direction in the figure. The brush roller 2 is driven to rotate in the clockwise direction in the figure.

  Both ends of the core shaft 17 extend outside the side wall of the cleaning case 15, and the end of the extended core shaft 17 and the sliding shaft 13 are coaxial, for example, as shown in FIG. A core shaft 17 is press-fitted into the hollow inside of the cylindrical sliding shaft 13 and is fixed so as not to rotate independently.

  The cam mechanism 30 is fixed to the support frame 41 of the cleaning unit 40 via a cylindrical fitting member 42 that fits into an opening 34 formed on the side wall of the bracket 31. The cylindrical fitting member 42 is assembled to the support frame 41 with a washer 44 and a screw 45.

  Further, as shown in FIG. 4, a bearing 46 is provided in the cylindrical fitting member 42, and when the sliding shaft 13 is fitted into the hollow inside of the cylindrical fitting member 42, the cylindrical fitting member 42 and the cylindrical fitting member 42 slide together. Since the moving shaft 13 can slide with respect to each other, the cleaning device 1 can thereby rotate with respect to the support frame 41 of the cleaning unit 40.

  Further, the upstream entrance, which is a gap formed between the cleaning case 15 upstream of the brush roller 2 in the normal direction of the photoconductor and the photoconductor 4, is sealed, so that the toner is discharged from the cleaning case 15 to the outside. A shielding plate 6 made of an elastic material such as rubber is provided as a leakage preventing member for preventing leakage. The base end portion of the shielding plate 6 is fixedly supported by the cleaning case 15, and the front end edge portion on the free end side opposite to the base end portion side is lightly pressed or brought close to the surface of the photoconductor 4.

  In the present embodiment, after the image forming operation is completed, the cleaning device 1 is moved away from the photosensitive member 4 by the operation of the cam mechanism 30 as shown in FIG. The plate 6 is pressed against the photosensitive member 4 and is rotated about the sliding shaft 13 so that the tip end portion is in contact with the brush roller 2. Then, after rotating the cleaning device 1 in this way, the brush roller 2 and the photoconductor 4 are rotated in the direction opposite to the normal rotation direction (hereinafter referred to as forward rotation) (hereinafter referred to as forward rotation). This is hereinafter referred to as inversion) and is rotated for a certain time.

  The rotation control of the cam 26 of the cam mechanism unit 30, the photosensitive member 4, and the brush roller 2 is performed by the control unit 20 shown in FIG. An image formation number counter 22 is connected, and a brush roller drive motor 19, a photoconductor drive motor 23, and a cam drive motor 24 are connected to the output side.

  In the control unit 20, the cam 26, the photoreceptor 4, and the brush roller are determined by determining the determination after the end of image formation with respect to the number of image formations set in the operation unit 21 based on the output content from the image formation number counter 22. 2 rotation control is executed.

  Here, since the image forming apparatus of the present embodiment has the above-described configuration, in the image forming process, after the toner image is transferred from the photoreceptor 4 onto the transfer paper 12, the transfer remaining on the surface of the photoreceptor 4 is transferred. When the residual toner 5a is conveyed to the cleaning device 1, the transfer residual toner 5a is scraped off from the surface of the photosensitive member by the brush 18 of the brush roller 2, or is damped by the leading edge portion of the cleaning blade 3 and is transferred to the photosensitive member 4. It is scraped off from the surface. Thereby, the surface of the photoconductor 4 is cleaned, and it is possible to suppress the transfer residual toner 5a from remaining on the photoconductor surface downstream of the cleaning device 1 in the normal photoconductor rotation direction.

  The transfer residual toner 5 a scraped off by the cleaning blade 3 falls downward and is received by the brush 18 of the brush roller 2, and is conveyed away from the surface of the photoreceptor by the rotation of the brush roller 2. At this time, since the brush 18 is in contact with the tip of the scraping member made of the flicker 25 provided on the inner surface of the cleaning case 15, the transfer residual toner 5 a received by the brush 18 is knocked off from the brush 18 by the flicker 25. Then, the toner is transported out of the cleaning case 15 by the toner discharge member 16, and is sent to and stored in a toner collection tank (not shown) provided in the image forming apparatus main body.

  Here, when the above-described cleaning process is repeated, a phenomenon in which foreign matters such as toner are sandwiched and accumulated between the cleaning blade 3 and the photoconductor 4 occurs, and the cleaning blade 3 is pressed against the surface of the photoconductor 4. Changes so that a sufficient cleaning effect cannot be obtained. When the toner sandwiched between the cleaning blade 3 and the photoreceptor 4 increases, a thin layer called filming occurs. This filming is a phenomenon in which the untransferred toner 5a that could not be removed from the surface of the photoreceptor by the cleaning blade 3 is thinly adhered to the wide area of the photoreceptor surface. Then, charging, development, transfer, and cleaning processes performed on the surface of the photoreceptor cannot be performed normally due to the deterioration of the characteristics of the surface of the photoreceptor due to filming, resulting in black spots on the formed image. Or white spots occur.

Therefore, in the present embodiment, after the image formation is completed, the cam 26 is rotated in the direction of the arrow C1 in FIG. 6 around the rotation shaft 26a pivotally supported on the image forming apparatus main body by a signal from the control unit 20 as shown in FIG. . As a result, the bracket 31 is pressed downward by the cam 26 against the elastic force of the spring 32 having one end fixed to the image forming apparatus and the other end fixed to the bracket 31. Thus, when the bracket 31 is pressed downward by the cam 26, the bracket 31 and the cleaning device 1 assembled to the bracket 31 rotate around the slide shaft 13 in the direction of arrow D1 in the figure. Here, the core shaft 17 and the sliding shaft 13 of the brush roller 2 of the cleaning device 1 of the present embodiment are configured to have the same shaft center. This makes it possible to vary the pressing force of the cleaning blade 3 and the shielding plate 6 against the photosensitive member 4 while keeping the positional relationship between the brush roller 2 and the photosensitive member 4 constant. In other words, the cleaning blade 3 moves in the direction away from the photosensitive member 4 (the pressing force is reduced) only by the rotational movement about the sliding shaft 13 of the cleaning case 15, and at the same time, the shielding plate 6 is moved to the photosensitive member 4. Moves in the direction of contact with (increases pressing force). During this time, there is no change in the positional relationship between the brush roller 2 and the photoconductor 4, so that the brush roller 2 is in contact with the photoconductor 4 more than the normal contact position, and for example, the surface of the photoconductor is damaged. This makes it possible to eliminate such a problem.
At this time, the bracket 31 rotates in the direction of the arrow D1 in the drawing, so that the shaft 33 that is in contact with the upper surface 31a of the bracket 31 moves from the upper surface 31a to the inclined surface 31b. Then, the shaft 33 and the inclined surface 31b are in contact with each other, so that the bracket 31 and the cleaning device 1 are prevented from rotating more than necessary due to the weight of the bracket 31 and the cleaning device 1 in the direction of the arrow D1 in the figure. As the cleaning device 1 rotates and moves in this manner, the contact pressure of the cleaning blade 3 with respect to the photosensitive member 4 becomes lower than the normal pressure during the image forming operation as shown in FIG. The toner 5c and foreign matter sandwiched between the body 4 are released from the state of being sandwiched.

  Further, when the cleaning device 1 is rotated about the sliding shaft 13 in the direction of arrow D1 in FIG. 6, the shielding plate 6 is pressed against the photoconductor 4 to bend more than in the image forming operation as shown in FIG. The leading edge portion of the shielding plate 6 is in contact with the brush 18 of the brush roller 2.

  Thus, the pressing force urged to the bracket 31 by the cam 26 with the shaft 33 as a fulcrum effectively acts as a force for pressing the shielding plate 6 provided in the cleaning case 15 of the cleaning device 1 against the photosensitive member 4.

  As described above, after the cleaning device 1 is rotated about the sliding shaft 13 in the direction of arrow D1 in FIG. 6, the photosensitive member 4 is moved by the photosensitive member driving motor 23 in accordance with the signal from the control unit 20 in FIG. In the direction A2, the brush roller 2 rotates in a direction indicated by an arrow B2 for a predetermined time, for example, about 30 seconds, and the toner 5c and foreign matter sandwiched between the cleaning blade 3 and the photoreceptor 4 are peeled off or removed. The

  Further, the toner 5b deposited on the leading edge portion of the shielding plate 6 (between the brush roller 2 and the shielding plate 6) is located at a position where the leading edge portion of the shielding plate 6 contacts the brush 18 of the brush roller 2. Therefore, the brush roller 2 can be removed from the front edge portion of the shielding plate 6 by the rotation operation.

  Further, since the brush roller 2 contacts the flicker 25 while rotating in the direction opposite to the normal rotation direction during the image forming operation, the brush 18 is prevented from falling down and the cleaning efficiency of the cleaning device 1 can be improved.

  After the reversal operation of the photosensitive member 4 and the brush roller 2 is completed, the cam 26 is driven by the cam drive motor 24 around the rotating shaft 26a that is pivotally supported by the image forming apparatus main body in response to a signal from the control unit 20, as shown in FIG. Is rotated in the direction of arrow C2 in the figure. As a result, the bracket 31 of the cam mechanism 30 is pulled upward by the spring 32. Thus, the bracket 31 is pulled upward by the spring 32, whereby the bracket 31 and the cleaning device 1 assembled to the bracket 31 rotate and move in the direction of the arrow D2 in the figure around the sliding shaft 13. At this time, when the bracket 31 rotates in the direction of the arrow D2 in the figure, the shaft 33 that is in contact with the inclined surface 31b of the bracket 31 in FIG. Although the bracket 31 and the cleaning device 1 rotate in the D2 direction rather than the position, the cam 26 is at the original specified position (see FIG. 5) because the slide shaft 13 is fixed to the support frame 41 via the cylindrical fitting member 42. 1), the cleaning device 1 takes a substantially horizontal posture with respect to the photoreceptor 4. By rotating the cleaning device 1 in this manner, the cleaning device 1 returns to the position at the time of the image forming operation again.

  FIG. 8 shows an example of a flowchart of the series of controls described above. After the image forming operation is completed (S1), the cleaning device 1 is rotated from the image forming operation position to the position during the reversing operation (S2). Then, the photosensitive member 4 and the brush roller 2 are rotationally driven in a normal reversal operation time (about 30 seconds) (S3). After the reversal operation of the photoconductor 4 and the brush roller 2 is completed (S4), the cleaning device 1 is rotated from the position during the reversal operation to the position during the image forming operation (S5).

  As described above, in the image forming apparatus of the present embodiment, when the image formation is completed, the contact pressure of the cleaning blade 3 with respect to the photoconductor 4 is reduced from the steady pressure, and the shielding plate 6 is pressed against the photoconductor 4 so that the tip is brush brushed. The toner and foreign matter sandwiched between the cleaning blade 3 and the photosensitive member 4 can be released and peeled off or slid by performing the reversing operation of the photosensitive member 4 and the brush roller 2 in the state of being in contact with the photosensitive member 2. . Further, by performing the reversing operation while bringing the brush roller 2 into contact with the flicker 25, it is possible to improve the falling of the hair of the brush roller 2 and to remove the toner accumulated between the shielding plate 6. From the above, it is possible to remove toner and foreign matter accumulated on the cleaning blade 3 and the shielding plate 6 of the cleaning device 1 by the behavior of the cleaning device 1 without using a special cleaning device. As a result, the maintenance of the cleaning device 1 is stable and excellent in handling so that the image forming apparatus main body, the hands and clothes of workers, the floor around the image forming apparatus main body, etc. can be cleaned cleanly. An image forming apparatus with high image quality can be provided.

  Although the cleaning operation of the cleaning blade 3 and the shielding plate 6 as described above has been performed after the image formation is completed so far, the brush roller 2 connected to the input side of the control unit 20 as shown in FIG. The cumulative number of revolutions of the brush roller 2 counted by the cumulative number of revolutions counter 27, the temperature and humidity in the image forming apparatus detected by the temperature / humidity sensor 28, or the electrostatic latent image formed on the photoconductor 4 detected by the writing unit 8. The laser emission density (image area ratio) of the image can also be used as a control condition for the cleaning operation of the cleaning blade 3 and the shielding plate 6 described above.

  For example, when the cumulative number of rotations of the brush roller 2 counted by the cumulative number of rotations counter 27 of the brush roller 2 after the end of the image forming operation is small, the brush 18 is not tumbled and the cleaning efficiency is high. The part 20 should just set the inversion operation time of the brush roller 2 shorter than usual. Conversely, when the cumulative rotational speed of the brush roller 2 counted by the cumulative rotational speed counter 27 is large, it is necessary to improve the hair fall of the brush 18, and therefore the reversing operation time of the brush roller 2 is set longer than usual.

  Further, when the inside of the image forming apparatus is at high temperature and high humidity, the toner charge amount is low and the amount of toner adhering to the photoreceptor 4 increases. Therefore, based on the information detected by the temperature / humidity sensor 28, the control unit 20 performs the cleaning operation of the cleaning blade 3 and the shielding plate 6 at a cycle shorter than usual. Conversely, when the inside of the image forming apparatus is at low temperature and low humidity, the toner charge amount is high and the amount of toner adhering to the photoreceptor 4 is reduced. Therefore, based on the information detected by the temperature / humidity sensor 28, the control unit 20 performs the cleaning operation of the cleaning blade 3 and the shielding plate 6 at a cycle longer than usual.

  Further, when the laser light emission density (image area ratio) of the electrostatic latent image formed on the photoconductor 4 detected by the writing device 8 is high density printing, the amount of toner attached to the photoconductor 4 increases. Therefore, the control unit 20 performs the cleaning operation of the cleaning blade 3 and the shielding plate 6 at a cycle shorter than usual. Conversely, in the case of low density printing, the amount of toner attached to the photoreceptor 4 is reduced. Therefore, the control unit 20 performs the cleaning operation of the cleaning blade 3 and the shielding plate 6 with a longer cycle than usual.

  Therefore, even in a situation where toner and foreign matter are likely to accumulate on the cleaning device 1 depending on the installation environment of the image forming apparatus, the printing density, etc., the period of the cleaning operation of the cleaning blade 3 and the shielding plate 6 as described above. By controlling the toner, it becomes possible to remove toner and foreign matters appropriately.

As described above, according to the present embodiment, the photosensitive member 4 that is an image carrier rotatably supported, the writing device 8 that is a latent image forming unit that forms a latent image on the photosensitive member 4, and the photosensitive member 4. A developing device 9 that is a developing unit that develops the latent image formed thereon with toner, a transfer device 10 that is a transfer unit that transfers a toner image on the photoreceptor 4 onto a transfer paper 12 that is a recording medium, and a photosensitive device. A cleaning case 15 in which an opening toward the body surface is formed; a brush roller 2 rotatably supported in the cleaning case 15 so as to be partly exposed from the opening and in contact with the surface of the photoreceptor; Rotating the brush roller 2 and the cleaning device 1 which is a cleaning means having a shielding plate 6 made of an elastic member which is provided at the lower edge of the opening and shields the gap formed between the cleaning case 15 and the photosensitive member 4 Driving A brush roller driving motor 19 that is a brush roller rotation driving unit that causes the brush roller 2 to come in contact with and separate from the leading edge portion that is the photosensitive member side end of the shielding plate 6; Control means for controlling the tip edge portion of the shielding plate 6 to be in contact with the brush roller 2 by the contact / separation means, rotating the brush roller 2 by the brush roller drive motor 19, and cleaning the shielding plate 6 by the brush roller 2. A certain control unit 20 is included. In the present embodiment, the tip edge portion of the shielding plate 6 is brought into contact with the brush roller 2, and the toner deposited on the tip edge portion of the shielding plate 6 is removed from the shielding plate 6 by the brush roller 2 that is driven to rotate. As a result, the toner accumulated on the leading edge portion of the shielding plate 6 during maintenance or the like falls out of the cleaning case 15 of the cleaning device 1, and the inside of the image forming apparatus main body, the operator's hand or clothes, or It is possible to prevent the floor around the image forming apparatus main body from becoming dirty.
In particular, in the present embodiment, the cam mechanism 30 as the contact / separation means displaces the cleaning device 1 with respect to the photosensitive member 4 and presses the shielding plate 6 against the photosensitive member 4 to bend the shielding plate 6. The tip edge portion of the shielding plate 6 is brought into contact with the brush roller 2. In the present embodiment, the tip edge portion of the shielding plate 6 is brought into contact with the brush roller 2, and the toner deposited on the tip edge portion of the shielding plate 6 is removed from the shielding plate 6 by the brush roller 2 that is driven to rotate. As a result, the toner accumulated on the leading edge portion of the shielding plate 6 during maintenance or the like falls out of the cleaning case 15 of the cleaning device 1, and the inside of the image forming apparatus main body, the operator's hand or clothes, or It is possible to prevent the floor around the image forming apparatus main body from becoming dirty.
Further, according to the present embodiment, the photosensitive member 4 can be rotationally driven by switching the rotational direction of the photosensitive member 4 between the normal rotational direction that is the rotational direction during the image forming operation and the reverse rotational direction of the normal rotational direction. A photosensitive member drive motor 23 which is an image carrier rotation driving means, and remains on the surface of the photosensitive member 4 in the cleaning case 15 of the cleaning device 1 downstream of the brush roller 2 in the normal rotation direction of the photosensitive member. A cleaning blade 3 that comes into contact with the photoconductor 4 at a pressure capable of scraping off the adhering matter such as toner is provided, and the control unit 20 determines the magnitude of the contact pressure of the cleaning blade 3 with respect to the photoconductor 4 in the image forming operation. At the end of the image forming operation, the cleaning device 1 is displaced with respect to the photosensitive member 4 so that the pressure is reduced from the steady pressure that is the contact pressure at that time, and the photosensitive member driving mode is reduced. Performs control to rotate the photosensitive body 4 in the reverse rotational direction by 23. As a result, the toner 5c and the foreign matter sandwiched between the cleaning blade 3 and the photoreceptor 4 can be removed or removed by sliding off.
Further, according to the present embodiment, the flicker 25 is a scraping member that is disposed in contact with the brush roller 2 in the cleaning case 15 of the cleaning device 1 and scrapes off the toner adhering to the brush roller 2 from the brush roller 2. The brush roller drive motor 19 rotates the brush roller 2 by switching the rotation direction of the brush roller 2 between a normal rotation direction that is a rotation direction during the image forming operation and a reverse rotation direction to the normal rotation direction. The control unit 20 performs control to rotate the brush roller 2 in the reverse rotation direction by the brush roller driving motor 19 when performing control to clean the shielding plate 6. Thereby, the fall of the brush roller 2 can be improved.
In addition, according to the present embodiment, the reversing operation time of the brush roller 2 is changed according to the cumulative number of rotations of the brush roller 2 to perform cleaning control according to the amount of hair fall of the brush 18, and for a long time. It is possible to maintain good cleaning properties. Moreover, since the fall of the brush 18 is improved at the same time, the reliability of the cleaning device 1 is improved.
Further, according to the present embodiment, the image forming apparatus main body is provided with the temperature / humidity sensor 28 in the apparatus, and the period of the cleaning operation is varied according to the detection result of the temperature / humidity sensor 28, thereby depending on the change in environment. Therefore, good cleaning properties can be maintained for a long period of time, and black streak images due to poor cleaning can be prevented.
In addition, according to the present embodiment, the writing device 8 that detects the laser issue density (image area ratio) of the electrostatic latent image formed on the photoconductor 4 is provided, and the cleaning operation is performed according to the detection result of the writing device 8. By changing the cycle, it is possible to maintain good cleaning performance over a long period of time regardless of the change in printing density, and it is possible to prevent black streak images due to poor cleaning.
Further, according to the present embodiment, the surface layer of the photoconductor 4 is made of a material that is difficult to be scraped off by the cleaning member, and in particular, the photoconductor 4 is made of a material containing amorphous silicon or inorganic particles capable of obtaining high hardness. Thus, it is possible to prevent the damage of the surface by suppressing the characteristic change due to the change in the film thickness and the surface damage, and it is possible to prevent the deposition due to the rubbing of the residual deposits generated when the surface property is deteriorated. In addition, even when such a high-hardness material that is hard to be scraped off by the cleaning member is used for the photosensitive member 4, it is possible to collect the residual deposits from the photosensitive member 4 only by using a cleaning blade or a brush roller as the cleaning member. Become.

DESCRIPTION OF SYMBOLS 1 Cleaning device 2 Brush roller 3 Cleaning blade 4 Photoconductor 5a Transfer residual toner 5b Toner 5c Toner 6 Shielding plate 7 Charging device 8 Writing device 9 Developing device 10 Transfer device 11 Static eliminating device 12 Transfer paper 13 Sliding shaft 15 Cleaning case 16 Toner Discharge member 17 Core shaft 18 Brush 19 Brush roller drive motor 20 Control unit 21 Operation unit 22 Image formation number counter 23 Photoconductor drive motor 24 Cam drive motor 25 Flicker 26 Cam 26a Rotating shaft 27 Cumulative rotation number counter 28 Temperature / humidity sensor 30 Cam Mechanism part 31 Bracket 31a Upper surface 31b Slope 32 Spring 33 Shaft 34 Opening 40 Cleaning unit 41 Support frame 42 Cylindrical fitting member 43 Cylindrical protrusion 44 Washer 45 Screw 46 Bearing

Japanese Patent No. 2759813

Claims (9)

An image carrier that is rotatably supported;
Latent image forming means for forming a latent image on the image carrier;
Developing means for developing the latent image formed on the image carrier with toner; transfer means for transferring the toner image on the image carrier onto a recording medium;
A casing in which an opening toward the surface of the image carrier is formed; a brush roller rotatably supported in the casing so that a part of the opening is exposed and contacts the surface of the image carrier; and the opening Cleaning means having a shielding plate made of an elastic member that is provided at the lower edge of the casing and shields a gap formed between the casing and the image carrier;
In an image forming apparatus comprising: a brush roller rotation driving unit that rotationally drives the brush roller;
Contact / separation means for contacting and separating the image carrier side end of the shielding plate with respect to the brush roller;
The image carrier side end of the shielding plate is brought into contact with the brush roller by the contact / separation means, the brush roller is rotationally driven by the brush roller rotation driving means, and the shielding plate is cleaned by the brush roller. An image forming apparatus comprising: a control unit that performs the control. The image forming apparatus according to claim 1.
The contact / separation means displaces the cleaning means with respect to the image carrier and presses the shielding plate against the image carrier to bend the shielding plate so that the image carrier side end of the shielding plate is brushed. An image forming apparatus which is brought into contact with a roller. The image forming apparatus according to claim 2.
An image carrier rotation driving means capable of rotating the image carrier by switching the rotation direction of the image carrier between a normal rotation direction which is a rotation direction at the time of image forming operation and a rotation direction opposite to the normal rotation direction. Have
In the casing of the cleaning means, the image carrier is at a pressure downstream of the brush roller in the normal rotation direction of the image carrier and at a pressure capable of scraping off deposits such as toner remaining on the surface of the image carrier. There is a cleaning blade in contact with
The control means controls the cleaning means by the contacting / separating means at the end of the image forming operation so as to reduce the magnitude of the contact pressure of the cleaning blade with respect to the image carrier from a steady pressure that is a contact pressure during the image forming operation. An image forming apparatus characterized in that the image carrier is controlled to be displaced with respect to the image carrier and to rotate the image carrier in the reverse rotation direction by an image carrier rotation driving means. The image forming apparatus according to claim 1, 2 or 3.
A scraping member disposed in contact with the brush roller in the casing of the cleaning means and scraping off the toner adhering to the brush roller from the brush roller;
The brush roller rotation driving means can rotate the brush roller by switching the rotation direction of the brush roller between a normal rotation direction which is a rotation direction at the time of image forming operation and a reverse rotation direction to the normal rotation direction. Yes,
The image forming apparatus according to claim 1, wherein the control unit performs control to rotate the brush roller in the reverse rotation direction by the brush roller rotation driving unit when performing control to clean the shielding plate. The image forming apparatus according to claim 1, 2, 3, or 4.
A cumulative rotational speed counting means for counting the cumulative rotational speed of the brush roller;
The control means controls the rotation driving time of the brush roller when performing the control for cleaning the shielding plate according to the cumulative rotation speed of the brush roller counted by the cumulative rotation speed counting means. Image forming apparatus. The image forming apparatus according to claim 1, 2, 3, 4, or 5.
A temperature / humidity detection means for detecting the temperature and humidity in the image forming apparatus main body is provided.
An image forming apparatus, wherein a period for performing control for cleaning the shielding plate is varied in accordance with the temperature and humidity in the image forming apparatus main body detected by the temperature and humidity detecting means. The image forming apparatus according to claim 1, 2, 3, 4, 5 or 6.
An image area ratio detecting means for detecting an image area ratio of a latent image formed on the image carrier,
An image forming apparatus, wherein a period for performing control for cleaning the shielding plate is varied in accordance with the image area ratio detected by the image area ratio detecting means. The image forming apparatus according to claim 1, 2, 3, 4, 5, 6 or 7.
The image forming apparatus, wherein the image carrier is a drum-shaped photosensitive body using amorphous silicon. The image forming apparatus according to claim 1, 2, 3, 4, 5, 6 or 7.
The image forming apparatus, wherein the image bearing member is a drum-shaped photosensitive member containing inorganic particles in at least an outermost layer.

Images