JP4811122B2 - Image forming apparatus, cleaning apparatus, and cleaning method - Google Patents

Description

  The present invention relates to an image forming apparatus, a cleaning apparatus, and a cleaning method capable of cleaning a residual developer remaining on an image carrier after transfer.

Charge the surface of the photoconductor, expose the charged photoconductor surface to form an electrostatic latent image, and supply toner as developer to the electrostatic latent image formed on the surface of the photoconductor to visualize the electrostatic latent image In an image forming apparatus that forms an image by transferring the visualized image to a transfer target, the residual toner remaining on the surface of the photosensitive member after transfer is generally cleaned by a cleaning member such as a rotary brush or a rotary roll. (For example, refer to Patent Document 1). More specifically, for example, when cleaning residual toner having a negative polarity, cleaning is performed by applying a positive voltage for cleaning to the cleaning member, and the cleaning roller that is in contact with the cleaning member is applied to the cleaning member. By applying a positive polarity voltage higher than the applied voltage, the toner is adsorbed on the collecting roll and finally scraped off and collected by a scraper.
Japanese Patent Laid-Open No. 4-093974

  However, if the applied voltage for cleaning is increased in order to generate a potential difference sufficient for cleaning between the cleaning member and the surface of the photoreceptor, charge is injected into the photoreceptor, and the potential of the photoreceptor itself is reduced. On the contrary, a sufficient potential difference may not be obtained and a cleaning failure may occur. In particular, in a high-temperature and high-humidity environment, charge injection is likely to occur, and there is a high probability that cleaning failure will occur. Hereinafter, this cleaning failure will be described with reference to graphs.

  FIG. 7 is a graph showing an example of the relationship between the voltage applied to the rotating brush, which is a cleaning member, and the amount of residual toner that has passed through the rotating brush without being cleaned, in each of the low-temperature and low-humidity environment and the high-temperature and high-humidity environment. .

  FIG. 8 is a graph showing an example of the relationship between the voltage applied to the rotating brush and the potential of the surface of the photoreceptor in each of the low temperature and low humidity environment and the high temperature and high humidity environment. Here, the potential of the surface of the photoreceptor before contact with the rotating brush to which the cleaning voltage was applied was set to 0 V, and the amount of change in the potential of the surface of the photoreceptor when the surface of the photoreceptor passed through the rotating brush was graphed.

  In the low temperature and low humidity environment, as apparent from FIG. 7, when the voltage applied to the rotating brush is 300V to 400V, the amount of residual toner that has passed through the rotating brush is small, and a good cleaning result is obtained. At this time, as shown in FIG. 8, the potential of the photosensitive member remains 0 V with almost no charge injection. That is, the voltage applied to the rotating brush is directly the potential difference between the photoconductor and the rotating brush. Therefore, in order to sufficiently clean the photoconductor, the potential difference between the photoconductor and the rotating brush needs to be 300V to 400V.

  On the other hand, in a high-temperature and high-humidity environment, charge injection to the photoconductor occurs when the applied voltage of the rotating brush is about 200 V. Therefore, no matter how much the applied voltage is increased, the potential of the photoconductor will rise. A sufficient potential difference cannot be generated between the photosensitive member and the rotating brush. Therefore, in a high temperature and high humidity environment, a potential difference of 200 V or more cannot be established between the rotating brush and the photosensitive member. For this reason, sufficient cleaning performance cannot be obtained in a high temperature and high humidity environment.

  In addition, since the discharge phenomenon occurs when the applied voltage exceeds 400 V, the potential of the photoconductor increases in both the low temperature and low humidity environment and the high temperature and high humidity environment. Therefore, when a voltage exceeding 400 V is applied, the residual toner amount slightly increases even in a low temperature and low humidity environment.

  The present invention has been made in order to solve the above-described problems, and ensures the residual developer not only in a low-temperature and low-humidity environment but also in a high-temperature and high-humidity environment where charge injection into the image carrier is likely to occur. It is an object of the present invention to provide an image forming apparatus, a cleaning apparatus, and a cleaning method that can clean the surface.

In order to achieve the above object, an image forming apparatus of the present invention includes an image carrier, a charging unit that charges the image carrier, and an electrostatic latent image that forms an electrostatic latent image on the charged image carrier. An image forming unit, a developing unit that visualizes the electrostatic latent image by supplying a developer to the electrostatic latent image formed on the image carrier, and a transfer unit that transfers the visualized image to a transfer target; A first cleaning member that cleans residual developer remaining on the image carrier after transfer by the transfer means in a state where a first voltage for cleaning is applied and in contact with the image carrier; A second cleaning for cleaning a residual developer remaining on the image carrier after transfer by the transfer means in a state where a second voltage having a polarity opposite to the voltage of 1 is applied and in contact with the image carrier. Cleaning and a member Including means, and a light discharging means for optically neutralizes the respective contact portion near said second cleaning member contact portion and near said image bearing member and said first cleaning member of the image bearing member It is configured.

According to such a configuration, even if electric charges are injected into the image carrier from the cleaning unit to which a cleaning voltage is applied, it is possible to neutralize light, so that the potential difference between the cleaning unit and the image carrier is sufficiently reduced. It is possible to reduce the residual developer that can be generated and pass through the cleaning means. Moreover, even if a discharge phenomenon occurs, the potential difference can be maintained by photostatic discharge and cleaning can be performed without any problem. Furthermore, even when both a negatively charged developer and a positively charged developer remain on the image carrier after the transfer, the remaining developer can be reliably cleaned, and defective cleaning can be prevented. Can do .

Together with the optical charge removing means optical charge removing through said first cleaning member and at least one wedge-shaped space portion of the image bearing member and said image bearing member rotational direction upstream side and downstream side formed by said cleaning means The static electricity can be eliminated through at least one wedge-shaped space portion on the upstream side and the downstream side in the rotation direction of the image carrier formed by the second cleaning member of the cleaning unit and the image carrier .

  As a result, the vicinity of the contact portion with the image carrier cleaning means can be reliably subjected to light neutralization.

The first cleaning member and the second cleaning member of the cleaning unit may be a rotatable brush or a rotatable roll member.

The cleaning device of the present invention includes an image carrier, a charging unit for charging the image carrier, an electrostatic latent image forming unit for forming an electrostatic latent image on the charged image carrier, and the image carrier. A cleaning device used in an image forming apparatus including a developing unit that supplies a developer to a formed electrostatic latent image to visualize the electrostatic latent image, and a transfer unit that transfers the visualized image to a transfer target. A first cleaning member that cleans residual developer remaining on the image carrier after transfer by the transfer means in a state where the first voltage for cleaning is applied and in contact with the image carrier; A second voltage having a polarity opposite to that of the first voltage is applied, and a residual developer remaining on the image carrier after the transfer by the transfer unit is cleaned while being in contact with the image carrier. 2 chestnuts A cleaning means having a training member, the first light neutralization of optical charge removing each contact portion near said second cleaning member contact portion and near said image bearing member and the cleaning member of the image bearing member And means.

Also in the cleaning device of the present invention, the photostatic discharge is performed in the same manner as the image forming device of the present invention, so that a potential difference between the cleaning means and the image carrier can be sufficiently generated, and defective cleaning can be prevented. Furthermore, even when both a negatively charged developer and a positively charged developer remain on the image carrier after the transfer, the remaining developer can be reliably cleaned, and defective cleaning can be prevented. Can do .

Further, the cleaning method of the present invention comprises an image carrier, a charging means for charging the image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the charged image carrier, and the image carrier. A cleaning method used in an image forming apparatus including a developing unit that supplies a developer to a formed electrostatic latent image to visualize the electrostatic latent image, and a transfer unit that transfers the visualized image to a transfer target. When the residual developer remaining on the image carrier after the transfer by the transfer means is cleaned by the first cleaning member and the second cleaning member, the first cleaning member contacts the image carrier. In this state, a first voltage is applied, and a second voltage having a polarity opposite to that of the first voltage is applied while the second cleaning member is in contact with the image carrier, and the image carrier is provided. The first of The contact portion near said second cleaning member contact portion and near said image bearing member and a cleaning member for optical neutralization.

Since the cleaning device of the present invention also performs photostatic discharge in the same manner as the image forming device of the present invention, it is possible to sufficiently generate a potential difference between the cleaning means and the image carrier and to prevent defective cleaning. Furthermore, even when both a negatively charged developer and a positively charged developer remain on the image carrier after the transfer, the remaining developer can be reliably cleaned, and defective cleaning can be prevented. Can do .

  As described above, according to the present invention, the residual developer can be reliably cleaned not only in a low-temperature and low-humidity environment but also in a high-temperature and high-humidity environment where charge injection into the image carrier is likely to occur. There is an excellent effect.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the present embodiment.

  The image forming apparatus 10 includes a cylindrical photosensitive member 12 as an image carrier, and rotates in the direction of arrow A by a driving force of a motor (not shown). Further, a charging roll 14, a developing roll 18, and an intermediate transfer body belt 20 are in contact with the photosensitive surface of the photoreceptor 12 in order along the rotation direction A. Further, a light beam is scanned on the photosensitive surface between the charging roller 14 and the developing roller 18 along the axial direction of the photosensitive member 12 from the exposure device 16.

  A predetermined bias voltage is applied to the charging roll 14 from a power source (not shown) to uniformly charge the surface of the photoreceptor 12.

  The exposure device 16 causes the charged photoconductor 12 to uniformly scan a light beam based on image data. As a result, the potential of the region scanned by the light beam on the photoconductor 12 is lowered to form an electrostatic latent image.

  The developing roller 18 is supplied with a predetermined developing bias voltage from a power source (not shown) to charge the toner to a negative polarity, and rotates in the same direction as the rotation direction of the photoconductor 12 to supply the charged toner to the photoconductor 12. is doing. Thereby, the electrostatic latent image formed on the photoconductor 12 is developed and visualized.

  The intermediate transfer belt 20 that rotates in the direction of arrow B is in contact with the photoconductor 12 downstream of the developing roll 18 in the rotation direction, and the primary transfer roll is sandwiched between the photoconductor 12 and the intermediate transfer belt 20. 22 is disposed. A positive transfer voltage having a polarity opposite to that of the toner is applied to the primary transfer roll 22 from a power source (not shown). The toner image on the photoreceptor 12 visualized by the developing roll 18 is primarily transferred to the intermediate transfer belt 20 by the transfer voltage applied to the primary transfer roll 22 and the pressure contact force of the primary transfer roll 22.

  Then, the toner image is transferred from the intermediate transfer belt 20 to the recording paper by the electrostatic attraction force of the secondary transfer roll (not shown) to which the transfer bias is applied to the recording paper conveyed to the secondary transfer position at a predetermined timing. Transcribed. The recording paper is further conveyed to a fixing device (not shown), and the toner image is fixed on the recording paper by heat and pressure. As a result, an image is formed on the recording paper.

  The specifications of main members and main electric specifications constituting the image forming apparatus 10 according to the present embodiment are as follows.

Photoconductor 12: Organic photoconductor having a diameter of about 30.0 mm
Charging potential = -500V (background potential)
Post-exposure potential = -200 V (image portion potential)
Charging roll 14: semiconductive roll
DC + AC contact charging system
VDC = -520v (DC component voltage value)
IAC = 0.65mA (AC component current value)
Frequency = 614Hz (AC component voltage waveform)
Exposure apparatus 16: Laser wavelength = 780 nm
Developing roll 18: Diameter = 16.0 mm
Rotation speed = 208mm / sec
Development bias: VDC = −400 V (DC component voltage value)
Vpp = 1500V (AC component voltage (Peak to Peak))
Frequency = 6 kHz (AC component voltage waveform)
Development system: Two-component development system Development gap (interval between the photosensitive member 12 and the developing roll 18): about 0.3 mm
Intermediate transfer belt 20: made of polyimide, process speed: 104 mm / sec, primary transfer roll 22: transfer bias + 500V to + 1000V
Secondary transfer roll (not shown): transfer bias + 1600V.

  Next, the cleaning device 40 provided in the image forming apparatus 10 of the present embodiment will be described.

  The cleaning device 40 includes a rotating brush 24, a collection roll 26, a scraper 28, and a light static eliminator 30.

  The rotating brush 24 is disposed downstream of the primary transfer roll 22 in the rotation direction A of the photoconductor 12 and is in contact with the photoconductor 12. After the toner image is transferred to the intermediate transfer belt 20 by the primary transfer roll 22, the rotary brush 24 cleans the transfer residual toner on the surface of the photoconductor 12 by applying a positive voltage for cleaning.

  The rotating brush 24 has a large number of brush fibers radially planted around a conductive rotating member, and is rotated by a motor (not shown). A cleaning voltage application unit 34 that applies a cleaning voltage is connected to the rotating member, and, for example, a bias of +300 V is applied. As a result, a potential difference is generated between the photosensitive member 12 and the rotating brush 24, and toner having a negative charge is attracted from the photosensitive member 12 to the rotating brush 24. As a material for the brush fiber, for example, nylon can be used.

  Further, a collection roll 26 having conductivity is in contact with a position on the opposite side of the rotary brush 24 from the photoconductor 12, and a scraper 28 is in contact with the collection roll 26. A voltage (for example, +600 V) having a voltage opposite to that of the toner and higher than the voltage applied to the rotating brush 24 is applied to the collection roll 26 by the collection roll voltage application unit 36. As a result, the toner of the rotating brush 24 is attracted to the rotating sleeve of the collection roll 26. The toner adsorbed on the collection roll 26 is scraped off and collected by a scraper 28 that contacts the peripheral surface of the collection roll 26.

  Further, in the image forming apparatus 10, an optical static eliminator 30 is disposed between the primary transfer roll 22 and the rotating brush 24. The light neutralizer 30 is driven by a light neutralization drive unit 28 and irradiates light through a wedge-shaped space formed by the photoconductor 12 and the rotary brush 24 to thereby contact the rotary brush 24 of the photoconductor 12. Static electricity is removed from the vicinity.

  A control device 32 is connected to the cleaning voltage application unit 34, the recovery roll voltage application unit 36, and the light neutralization drive unit 38. During the image forming operation of the image forming apparatus 10 (during the rotation of the photosensitive member 12), the control device 32 applies a cleaning voltage so that each unit operates and a cleaning voltage is applied to the rotating brush 24 and the collecting roll 26. In addition to controlling the unit 34 and the recovery roll voltage application unit 36, the light static elimination drive unit 38 is controlled such that the vicinity of the contact portion of the rotating brush 24 of the photoconductor 12 is photo-statically eliminated by the photo-electric neutralizer 30.

  Hereinafter, a flow from forming a toner image in the image forming apparatus 10 to transferring the toner image onto the intermediate transfer belt 20 and collecting the toner remaining on the surface of the photoreceptor 12 after the transfer will be briefly described.

  As shown in FIG. 1, when the photoconductor 12 rotates in the direction of arrow A in the drawing, first, the photoconductor 12 is uniformly charged to a predetermined polarity potential by the charging roll 14. In the present embodiment, a bias voltage obtained by superimposing a DC voltage of −520 V and an AC voltage that generates an AC current of 0.65 mA is applied to the charging roll 14, and the surface of the photoreceptor 12 is charged to, for example, −500 V. The

  When the photoconductor 12 further rotates, the charged surface of the photoconductor 12 is scanned and exposed by the exposure device 16 based on the image data, and the potential of the exposed portion of the charged surface is lowered (for example, −200 V). An electrostatic latent image is formed. Thereafter, the toner charged negatively by the developing roll 18 to which a developing bias voltage in which a DC voltage of −400 V and an AC voltage having a peak-to-peak potential difference of 1500 V are superimposed is applied is exposed on the charged surface. By electrically adhering to the portion, the electrostatic latent image is developed (visualized) to form a toner image.

  Then, when the formed toner image passes through the primary transfer position as the photoconductor 12 rotates, the toner image is electrically applied to the primary transfer roll 22 to which a primary transfer voltage of +500 V opposite to the polarity of the toner is applied. It is attracted and transferred from the photoconductor 12 to the intermediate transfer belt 20.

  However, in the image forming apparatus 10, transfer residual toner that remains on the photoreceptor 12 without being transferred to the intermediate transfer belt 20 is generated.

  Therefore, in the cleaning device 40 described above, a positive voltage for cleaning is applied to the rotating brush 24, and the transfer residual toner charged to the negative polarity is attracted to the rotating brush 24 and collected (cleaned). The transfer residual toner collected on the rotary brush 24 moves to a collection roll 26 to which a positive polarity voltage higher than that of the rotary brush 24 is applied, and is scraped off and collected by a scraper 28.

  On the other hand, during the image forming operation (during rotation of the photoconductor 12), light is irradiated from the upstream side in the rotation direction A of the photoconductor 12 through a wedge-shaped space formed by the photoconductor 12 and the rotary brush 24. As a result, the vicinity of the contact portion between the photosensitive member 12 and the rotating brush 24 is always subjected to light neutralization. As a result, the vicinity of the contact portion of the photosensitive member 12 with the rotating brush 24 can be neutralized with light even when electric charge is injected from the rotating brush 24 to be in a 0V state. Therefore, the potential difference between the rotating brush 24 and the photosensitive member 12 is reduced. Thus, the amount of residual toner that passes through the rotary brush 24 can be reduced.

  In the image forming apparatus 10 of the present embodiment, the photosensitive member 12 is rotated in a state where a certain amount of transfer residual toner is adhered to the photosensitive member 12, and the portion where the transfer residual toner is adhered is passed through the rotating brush 24. The amount of toner passing through the rotating brush 24 with respect to the applied voltage of the rotating brush 24 at this time was examined in each of the high temperature and high humidity environment and the low temperature and low humidity environment. The obtained results are shown in FIG.

  As shown in the figure, in the cleaning device 40 provided in the image forming apparatus 10 according to the present embodiment, light is irradiated through the wedge-shaped space formed by the photosensitive member 12 and the rotating brush 24 as described above. Then, in order to neutralize the vicinity of the contact portion of the photosensitive member 12 with the rotating brush 24, when a voltage of +300 V to +400 V is applied to the rotating brush 24 not only in a low temperature and low humidity environment but also in a high temperature and high humidity environment, It can be seen that a sufficient potential difference can be generated between the rotating brush 24 and the photosensitive member 12, the amount of toner passing through the rotating brush 24 is small, and sufficient cleaning performance can be exhibited.

  If light neutralization is not performed, the rotation of the photosensitive member increases to about 200 V due to charge injection even when +300 to +400 V is applied to the rotating brush 24 as shown in FIG. 7 in a high temperature and high humidity environment. The potential difference between the brush 24 and the photosensitive member 12 can be only 100 to 200 V. However, in the cleaning device 40 of the image forming apparatus 10, the photosensitive member potential is reduced by light neutralization, so that a rotating brush is used as shown in FIG. A potential difference close to 300 to 400 V can be generated between the photosensitive member 24 and the photosensitive member 12, and defective cleaning can be prevented.

  Although a discharge occurs when a voltage exceeding +400 V is applied to the rotating brush 24, a potential difference between the rotating brush 24 and the photosensitive member 12 can be sufficiently generated by light neutralization even in this discharge region, so that defective cleaning can be prevented. .

  In this embodiment, the image forming apparatus that transfers the toner image to the recording paper via the intermediate transfer belt 20 has been described as an example. However, the image forming apparatus is configured to transfer directly from the photosensitive member 12 to the recording paper. It may be an image forming apparatus.

[Second Embodiment]
In the second embodiment, a mode in which the arrangement of the light static eliminator and the light irradiation direction are different from those in the first embodiment will be described.

  FIG. 3 is a schematic configuration diagram of the image forming apparatus 10a according to the present embodiment. The image forming apparatus 10a according to the present embodiment is the same as the image forming apparatus 10 according to the first embodiment except that the light static eliminator 30 in the cleaning device 40a is arranged downstream of the rotating brush 24 in the rotation direction A of the photosensitive member 12. It is the same composition as. In FIG. 3, the controller 32, the cleaning voltage application unit 34, the recovery roll voltage application unit 36, and the light static elimination drive unit 38 (so-called control system configuration) are not shown.

  The light static eliminator 30 of this embodiment irradiates light from the downstream side in the rotation direction A of the photoconductor 12 through a wedge-shaped space formed by the photoconductor 12 and the rotary brush 24, and The vicinity of the contact portion with the rotating brush 24 is neutralized.

  Also in the image forming apparatus 10a of the present embodiment, when the amount of toner passing through the rotating brush 24 with respect to the voltage applied to the rotating brush 24 was examined, the same effect as in the first embodiment was obtained.

[Third Embodiment]
In the third embodiment, a mode will be described in which neutralization is performed by irradiating light in the vicinity of the contact portion of the photoconductor 12 with the rotating brush 24 from both the upstream side and the downstream side in the rotation direction A of the photoconductor 12.

  FIG. 4 is a schematic configuration diagram of the image forming apparatus 10b according to the present embodiment. As shown in the drawing, in the cleaning device 40 a, the two light static eliminators 30 a and 30 b are arranged on both the upstream side and the downstream side in the rotation direction A of the photoreceptor 12 with respect to the rotating brush 24. Other than this, the configuration is the same as that of the image forming apparatus 10 of the first embodiment. In FIG. 4, illustration of the configuration of the control system is omitted.

The light static eliminator 30a of the present embodiment irradiates light from the upstream side in the rotation direction A of the photoconductor 12 through a wedge-shaped space formed by the photoconductor 12 and the rotary brush 24, and the light static eliminator 30b Light is irradiated from the downstream side in the rotation direction A of the photoconductor 12 through a wedge-shaped space formed by the photoconductor 12 and the rotary brush 24. As a result, even in the image forming apparatus 10b according to the present embodiment, where the vicinity of the contact portion between the photosensitive member 12 and the rotating brush 24 is removed, the amount of toner passing through the rotating brush 24 with respect to the applied voltage of the rotating brush 24 is examined. The same effect as in the first embodiment was obtained.

  In addition, as the density of the brush fibers of the rotating brush 24 increases, the light from the photostatic discharger hardly reaches the portion where charge injection occurs from the rotating brush 24 of the photoconductor 12. Therefore, when using a rotating brush having a high density of brush fibers, the method of removing light from both the upstream side and the downstream side is particularly effective.

[Fourth Embodiment]
In the fourth embodiment, an example in which a conductive roll is used instead of the rotating brush 24 will be described.

  FIG. 5 is a schematic configuration diagram of an image forming apparatus 10c according to the present embodiment. The image forming apparatus 10c of the present embodiment has the same configuration as that of the first embodiment except that a conductive roll 25 is provided instead of the rotating brush 24 as a cleaning member of the cleaning apparatus 40c. In FIG. 5, illustration of the configuration of the control system is omitted.

  Also in the image forming apparatus 10c of the present embodiment, when the amount of toner passing through the rotating brush 24 with respect to the voltage applied to the rotating brush 24 was examined, the same effect as in the first embodiment was obtained.

[Fifth Embodiment]
In the fifth embodiment, a mode in which two rotating brushes are provided as cleaning members of the cleaning device and an optical static eliminator is provided for each rotating brush will be described.

  For example, an image forming unit including a photoreceptor, a charging roll, a developing roll, a transfer roll, and a cleaning device is arranged in series for each color of Y (yellow), M (magenta), C (cyan), and K (black). In the case of an image forming apparatus that forms a color image by sequentially superimposing and transferring (multiple transfer) the toner images formed by each unit on the intermediate transfer belt, image formation on the upstream side in the process direction When the toner image transferred from the photosensitive member to the intermediate transfer member by the unit passes through the transfer portion of the downstream image forming unit, it adheres to the photosensitive member of the downstream image forming unit and is peeled off from the intermediate transfer member. The phenomenon taken, so-called retransfer, may occur. The toner adhering to the photoconductor by retransfer is charged to the positive polarity by the positive polarity voltage applied to the primary transfer roll 22, so that the transfer residual toner is collected by the rotating brush to which the positive polarity voltage is applied. It is not possible.

  Therefore, as shown in FIG. 6, in the image forming apparatus 10d of this embodiment, two cleaning members of the cleaning device 40d are used as cleaning members in order to clean both negative transfer residual toner and positive transfer residual toner. Rotating brushes 24a and 24b were provided.

  Further, the cleaning device 40d includes a collection roll 26a, 26b that contacts the rotary brushes 24a, 24b and collects toner adhering to the rotary brushes 24a, 24b, and a scraper that scrapes the toner from the collection rolls 26a, 26b. 28a and 28b were provided. In the vicinity of the rotary brushes 24a and 24b, the light neutralizers 30a and 30b corresponding to the rotary brushes are arranged.

  The cleaning operation by the cleaning device 40d will be briefly described. First, a positive polarity voltage for cleaning is applied to the rotating brush 24a to collect the negative transfer residual toner. A voltage having a positive polarity larger than the voltage applied to the rotating brush 24a is applied to the collecting roll 26a that is in contact with the rotating brush 24a to adsorb the toner adhering to the rotating brush 24a, and further, the collecting roll The toner adhering to 26a is scraped off and collected by the scraper 28a. As a result, the negative polarity residual toner is cleaned.

  On the other hand, a negative polarity voltage is applied to the rotating brush 24b to collect the positive polarity transfer residual toner. A voltage having a negative polarity larger than the voltage applied to the rotating brush 24b is applied to the collecting roll 26b that is in contact with the rotating brush 24b to adsorb the toner adhering to the rotating brush 24b. The toner adhering to 26a and 26b is scraped off and collected by a scraper 28b. Thus, the positive polarity residual toner is cleaned.

  At this time, the light static eliminator 30a irradiates light from the upstream side in the rotation direction A of the photoconductor 12 through a wedge-shaped space formed by the photoconductor 12 and the rotary brush 24a, so that the rotary brush of the photoconductor 12 is irradiated. The static eliminator 30b irradiates light from the downstream side in the rotation direction A of the photoconductor 12 through a wedge-shaped space formed by the photoconductor 12 and the rotary brush 24b. Thus, the vicinity of the contact portion of the photosensitive member 12 with the rotating brush 24b is neutralized.

  As a result, the potential difference between the photosensitive member 12 and the rotating brush 24a can be sufficiently generated, so that negative polarity toner can be collected, and the potential difference between the photosensitive member 12 and the rotating brush 24b can be sufficiently generated. The positive polarity toner can be collected. As a result, sufficient cleaning performance is exhibited.

  Here, an example in which a positive polarity voltage is applied to the rotating brush 24a and the collecting roll 26a and a negative polarity voltage is applied to the rotating brush 24b and the collecting roll 26b has been described. However, the polarity of the applied voltage is reversed. It may be.

1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment. In the image forming apparatus according to the first embodiment, an example of the relationship between the voltage applied to the rotating brush and the amount of residual toner that has passed through the rotating brush without being cleaned is in each of the low-temperature and low-humidity environment and the high-temperature and high-humidity environment. It is the graph shown about. It is a schematic block diagram of the image forming apparatus which concerns on 2nd Embodiment. It is a schematic block diagram of the image forming apparatus which concerns on 3rd Embodiment. It is a schematic block diagram of the image forming apparatus which concerns on 4th Embodiment. It is a schematic block diagram of the image forming apparatus which concerns on 5th Embodiment. In a conventional image forming apparatus without an optical static eliminator, an example of the relationship between the voltage applied to a rotating brush as a cleaning member and the amount of residual toner that has passed through the rotating brush without being cleaned is shown in each of a low temperature and low humidity environment and a high temperature and high humidity environment. It is the graph shown about the case of. 6 is a graph showing an example of a relationship between a voltage applied to a rotating brush and a potential on the surface of a photoreceptor in each of a low temperature and low humidity environment and a high temperature and high humidity environment in a conventional image forming apparatus that does not have a light neutralizer.

Explanation of symbols

10, 10a, 10b, 10c, 10d Image forming apparatus 12 Photoconductor 14 Charging roll 16 Exposure apparatus 18 Developing roll 20 Photoconductor 20 Intermediate transfer belt 22 Primary transfer rolls 24, 24a, 24b Rotating brush 25 Conductive rolls 26, 26a 26b Recovery rolls 28, 28a, 28b Scrapers 30, 30a, 30b Optical static eliminators 40, 40a, 40b, 40c, 40d Cleaning devices

Claims (5)

An image carrier;
Charging means for charging the image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the charged image carrier;
Developing means for visualizing the electrostatic latent image by supplying a developer to the electrostatic latent image formed on the image carrier;
Transfer means for transferring the visualized image to a transfer target;
A first cleaning member that cleans residual developer remaining on the image carrier after transfer by the transfer means in a state where a first voltage for cleaning is applied and in contact with the image carrier; A second cleaning for cleaning a residual developer remaining on the image carrier after transfer by the transfer means in a state where a second voltage having a polarity opposite to the voltage of 1 is applied and in contact with the image carrier. Cleaning means having a member ;
A light neutralizing means for performing light neutralization on each of the vicinity of the contact portion of the image carrier with the first cleaning member and the vicinity of the contact portion of the image carrier with the second cleaning member ;
An image forming apparatus including: Together with the optical charge removing means optical charge removing through said first cleaning member and at least one wedge-shaped space portion of the image bearing member and said image bearing member rotational direction upstream side and downstream side formed by said cleaning means 2. The image according to claim 1, wherein the static electricity is neutralized through at least one wedge-shaped space portion upstream and downstream in the rotation direction of the image carrier formed by the second cleaning member of the cleaning unit and the image carrier. Forming equipment. The image forming apparatus according to claim 1, wherein the first cleaning member and the second cleaning member of the cleaning unit are a rotatable brush or a rotatable roll-shaped member. Image carrier, charging means for charging the image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the charged image carrier, development to an electrostatic latent image formed on the image carrier A cleaning device used in an image forming apparatus including a developing unit that supplies an agent to visualize an electrostatic latent image, and a transfer unit that transfers the visualized image to a transfer target,
A first cleaning member that cleans residual developer remaining on the image carrier after transfer by the transfer means in a state where a first voltage for cleaning is applied and in contact with the image carrier; A second cleaning for cleaning a residual developer remaining on the image carrier after transfer by the transfer means in a state where a second voltage having a polarity opposite to the voltage of 1 is applied and in contact with the image carrier. Cleaning means having a member ;
A light neutralizing means for performing light neutralization on each of the vicinity of the contact portion of the image carrier with the first cleaning member and the vicinity of the contact portion of the image carrier with the second cleaning member ;
Including cleaning device. Image carrier, charging means for charging the image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the charged image carrier, development to an electrostatic latent image formed on the image carrier A cleaning method used in an image forming apparatus including a developing unit that supplies an agent to visualize an electrostatic latent image, and a transfer unit that transfers the visualized image to a transfer target,
When the residual developer remaining on the image carrier after the transfer by the transfer means is cleaned by the first cleaning member and the second cleaning member, the first cleaning member is in contact with the image carrier. A first voltage is applied, and a second voltage having a polarity opposite to the first voltage is applied in a state where the second cleaning member is in contact with the image carrier, and the first voltage of the image carrier is changed. A cleaning method in which the vicinity of the contact portion with the first cleaning member and the vicinity of the contact portion of the image carrier with the second cleaning member are subjected to light neutralization .

Images