JP2007233281A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that detects the position of a cleaning member when powered on without being equipped with a position detection sensor etc., and retracts the cleaning member to a position where image forming operation is not affected at need. <P>SOLUTION: The image forming apparatus is equipped with an image carrier, a corona charger installed in a circumference of the image carrier, a cleaning mechanism equipped with the cleaning member capable of moving along discharge wire extended in the corona charger, and a cleaning control means 32 of driving and controlling the cleaning member between a retraction region and a cleaning region in an expected period. The image forming apparatus is further equipped with a state storage means 33 of storing the operation state of the cleaning mechanism, and the cleaning control means 32 once detecting the cleaning mechanism being in operation through the state storage means 33 when the power source is turned on drives and controls the cleaning member to the retraction region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a charger cleaning device for an image forming apparatus that includes a cleaning member that cleans at least a discharge wire of a charger having a discharge wire, and a control unit that controls the operation of the cleaning member.

  Conventionally, in an electrophotographic image forming apparatus including a corona charger with a discharge wire stretched, by using the image forming apparatus, a discharge product or scattering is applied to the discharge wire stretched over the corona charger. There is a possibility that uneven discharge occurs due to toner, paper dust, etc., and the corona charger is equipped with a cleaning member for cleaning the discharge wire, and the discharge unevenness can be suppressed by cleaning dirt. It had been.

  The corona charger includes a charging unit for an increase carrier, a transfer unit for transferring a toner image carried on the image carrier to a recording medium, and a toner image carried on the image carrier before a transfer process by the transfer unit. Used for pre-transfer charging means for adjusting the charge amount of the recording medium, separation means for separating the recording medium that has undergone the transfer step from the image carrier, and the like. For example, the corona charger discharge wire used for the transfer means and the separation means is more likely to have scattered toner, paper powder, and the like than the corona charger discharge wire used for the image carrier charging means, It was easy to get dirty.

  Therefore, in Patent Document 1, the timing for cleaning the corona charger is set for each charger to prevent the occurrence of uneven charging, and the charging means for the image carrier. There has been proposed an image forming apparatus that increases the time until the cleaning member of the corona charger reaches the end of its life.

JP 2002-268339 A

  However, when the power supply of the image forming apparatus is turned off during the cleaning of the discharge wire of the corona charger and the cleaning member stays at the cleaning portion of the discharge wire, the image forming operation is performed during the operation of the image forming apparatus. Although there is a possibility of adverse effects, it has not been considered in the above-described prior art, and there is room for further improvement. Further, if the image forming apparatus is provided with a position detection sensor or the like to detect the position of the cleaning member, the number of members increases and the cost increases, and the control means for the cleaning member becomes complicated, which is not preferable.

  In view of the above-described conventional drawbacks, the present invention detects the position of the cleaning member when the power is turned on without providing a position detection sensor or the like, and moves the cleaning member to a position that does not affect the image forming operation as necessary. The object is to provide an image forming apparatus to be retracted.

  In order to achieve the above-mentioned object, a first characteristic configuration of an image forming apparatus according to the present invention includes an image carrier and a periphery of the image carrier as described in claim 1 of the claims. And a cleaning mechanism having a cleaning member movable along the discharge wire stretched around the corona charger, and driving the cleaning member between the retreat area and the cleaning area at a predetermined time. An image forming apparatus comprising a cleaning control means for controlling, comprising: a state storage means for storing an operation state of the cleaning mechanism, wherein the cleaning control means is operated by the state storage means when the power is turned on. If it is detected, the cleaning member is driven and controlled to the retreat area.

  According to the above-described configuration, the cleaning control unit detects that the cleaning mechanism is in the operating state by the state storage unit when the power is turned on, in other words, detects that the cleaning member is in the cleaning region, Since drive control is performed in the retreat area, uneven charging due to the cleaning member can be prevented, and image disturbance during image formation can be avoided.

  According to the second feature configuration, in addition to the first feature configuration described above, the state storage unit is configured by a counter that counts a required cleaning time by the cleaning mechanism, and the cleaning control is performed. When the means detects that the cleaning mechanism is in an operating state based on the value of the counter at the time of power-on, the cleaning mechanism is driven and controlled for the maximum required movement time of the cleaning member to the retreat area. is there.

  According to the above-described configuration, the cleaning control unit can reliably retract the cleaning member to the retreat area regardless of the position of the cleaning member in the cleaning area.

  In the third feature configuration, as described in claim 3, in addition to the first feature configuration described above, the state storage unit is configured by a counter that counts a required cleaning time by the cleaning mechanism, and the cleaning control is performed. When the means detects that the cleaning mechanism is in an operating state based on the value of the counter when the power is turned on, the minimum required moving time of the cleaning member to the retreat area calculated based on the value of the counter Only the drive of the cleaning mechanism is controlled.

  According to the above-described configuration, the cleaning control unit can retract the cleaning member to the retreat area in the shortest time regardless of the position of the cleaning member in the cleaning area.

  In the fourth feature configuration, as described in claim 4, in addition to the first feature configuration described above, the state storage unit is configured by a counter that counts a required cleaning time by the cleaning mechanism, and the cleaning control is performed. When the means detects that the cleaning mechanism is in an operating state based on the value of the counter when the power is turned on, an uncleaned area is calculated based on the cleaning history of the cleaning member calculated based on the value of the counter. The cleaning mechanism is driven and controlled for a time required to move to the retreat area after cleaning.

  According to the above-described configuration, the cleaning control unit reliably cleans the uncleaned region of the discharge wire to prevent the occurrence of charging unevenness even when the cleaning member is in any position of the cleaning region. The cleaning member can be retreated to the retreat area.

In addition to any one of the first to fourth feature configurations described above, the fifth feature configuration includes switch means for forcibly returning the cleaning member to the retreat area, as described in claim 5. The cleaning control means is configured to drive and control the cleaning member to the retreat area when the switch means is operated.

  According to the above configuration, when the cleaning member is in the cleaning area for some reason, for example, when the cleaning member is in the cleaning area for maintenance by a serviceman, the cleaning member is surely moved to the retreat area. Can be evacuated.

  As described above, according to the present invention, the position of the cleaning member when the power is turned on without a position detection sensor or the like is detected, and the cleaning member is moved to a position that does not affect the image forming operation as necessary. An image forming apparatus that can be retracted can be provided.

  The image forming apparatus according to the present invention will be described below. As shown in FIG. 2, a copying machine A that is an example of an image forming apparatus according to the present invention has an image reading unit 1 that reads a document image as document image data, and a predetermined amount of document image data that is read by the image reading unit 1. An output image data generation unit 2 that performs the above processing to generate output image data, and an image that is output after forming an image on recording paper D that is an output sheet based on the output image data from the output image data generation unit 2 A forming unit 3, a hard key group such as a print key for starting a copying operation of the copying machine A and a numerical key for setting the number of copies, an operation panel unit 4 including a touch panel type color liquid crystal display unit, The system control unit 5 is configured to control and control the control unit.

  The image forming unit 3 includes a toner image forming unit 301 that forms a toner image on a photoconductor 302 serving as an image carrier based on the output image data, and the toner image formed on the photoconductor 302 in a transfer unit 306. Is transferred to the recording paper D onto which the toner is transferred, a heater (not shown) in which the toner image transferred onto the recording paper D is inserted and installed, and a temperature sensor (not shown). The image forming apparatus includes a fixing unit 314 that is heated and melted by a fixing roller heated to a temperature, and an image forming control unit 30 that controls each part of the image forming unit 3.

  The transport unit includes a paper feed cassette 309 in which recording sheets D of different sizes are accommodated, a paper feed transport unit 310 that transports the recording paper D one by one, and the transfer of the fed recording paper D. A fixing conveyance unit 311 that conveys the recording sheet D onto which the toner image has been transferred to the fixing unit 314; and discharges the recording sheet D that has passed through the fixing unit 314 to a discharge tray 312. A paper discharge conveyance unit 313 for paper is provided.

  The toner image forming unit 301 includes the photosensitive member 302, a charging charger 303 including a corona charger that is disposed around the photosensitive member 302 in order and uniformly corona-charges the surface, and the charged photosensitive member 302. A print head 304 that forms an electrostatic latent image by exposure, a developing unit 305 that visualizes the toner image by electrostatically attaching toner to the formed electrostatic latent image, and the toner image on the recording paper D A transfer unit 306 for transferring the toner, a cleaning unit 307 for removing toner remaining on the photoconductor 302 after the transfer, and a static elimination lamp 308 for reducing the residual potential on the surface of the photoconductor 302 to make it uniform. Yes. In the developing unit 305, development blocks of four colors of cyan, magenta, yellow, and black are arranged so that a color image can be generated.

  As shown in FIG. 3, the charging charger 303 includes a discharge wire 303b stretched within a shield case 303a of the discharge charger 303, a cleaning mechanism 303e movable along the discharge wire 303b, and forward / reverse drive. This is a corotron type charger having a rotary drive mechanism 303d composed of a possible DC motor and gears, and a helical shaft 303c that is driven to rotate forward and backward by the rotary drive mechanism 303d.

  As shown in FIGS. 4A and 4B, the cleaning mechanism 303e is screwed into the cleaning members 303f and 303g, the cleaning member holding mechanism 303h that holds the cleaning members 303f and 303g, and the helical shaft 303c. And a female screw member 303i that moves the cleaning member holding mechanism 303h along the discharge wire 303b by the rotational movement of the helical shaft 303c, and has no spirals formed at both ends of the helical shaft 303c. In the spiral portion, the female screw member 303i is loosely fitted, and is further pressed and compressed by the female screw member 303i, and is installed so as to urge the female screw member 303i in a direction opposite to the screwing direction. (Not shown) so that the female screw member 303i is pressed against the end of the spiral portion of the spiral shaft 303c. Because, when the helical axis 303c is reversely rotated, the female screw member 303i is screwed securely with the helical shaft 303c, the cleaning mechanism 303e is reliably driven in the reverse direction.

  In the traveling direction of the cleaning mechanism 303e, as shown in FIG. 4A, the cleaning members 303f and 303g contact the discharge wire 303b and clean the discharge wire 303b, and the cleaning member holding There is a non-cleaning direction in which the cleaning member 303f, 303g is separated from the discharge wire 303b and the discharge wire 303b is not cleaned, while the mechanism 303h is inclined opposite to the traveling direction.

  As shown in FIG. 1, the image forming control unit 30 includes an image forming unit 31 that controls the above-described image forming operation, a cleaning control unit 32 that drives and controls a cleaning mechanism 303e including the cleaning members 303f and 303g, The storage unit 33 includes a state storage unit 33 that stores an operation state of the cleaning mechanism 303e. Each unit is executed by a microcomputer, a RAM, or the like included in the image formation control unit 30.

  The cleaning control means 32 corresponds to both ends of the spiral shaft 303c, and one end of each end is a home position (HP) of the cleaning mechanism 303e in which the cleaning mechanism 303e is normally stored except when cleaning is performed, and the other end is The cleaning is performed by controlling the rotation drive mechanism 303d at a predetermined time between a retreat area which is a temporary home position (temporary HP) and a cleaning area where the cleaning members 303f and 303g perform cleaning of the discharge wire 303b. The mechanism 303e is driven and controlled. Accordingly, the cleaning members 303f and 303g provided in the cleaning mechanism 303e also have the retreat area and the cleaning area formed by the home position and the temporary home position, and the cleaning members 303f and 303g have the cleaning control. The drive control is performed between the retreat area and the cleaning area by the means 32 at the predetermined time.

  Here, a direction in which the cleaning mechanism 303e and the cleaning members 303f and 303g are driven from the home position to the temporary home position is defined as the cleaning direction, and a direction in which the cleaning mechanism 303e and the cleaning members 303f and 303g are driven from the temporary home position to the home position is the non-cleaning direction. And In other words, the cleaning control means 32 drives and controls the cleaning mechanism 303e at the predetermined time, first in the cleaning direction from the home position to the temporary home position, and then in the non-cleaning direction from the temporary home position to the home position. Thus, the cleaning members 303f and 303g clean the discharge wire 303b of the charging charger 303.

  The state storage unit 33 includes a counter 34 that counts the number of internal clocks (not shown) provided in the image formation control unit 30 and a count value that the counter 34 counts. The cleaning control means 32 includes the cleaning mechanism 303e until the count value stored in the count storage means 35 reaches a first predetermined value. Drive control is performed in the cleaning direction, and drive control is performed in the non-cleaning direction until the second predetermined value is reached from the first predetermined value. The state storage means 33 resets the count value stored in the count storage means 35 to “0” when the cleaning mechanism 303e is at the home position. That is, as shown in FIG. 5, the state storage unit 33 counts up the count value until the cleaning mechanism 303 e returns from the home position to the home position again, and stores the count value in the count storage unit 35. Therefore, by referring to the count value of the count storage means 35, the position and operating state of the cleaning mechanism 303e can be known.

  In this embodiment, the predetermined time is not the time when the power is turned on in order to shorten the warm-up time when the power is turned on such as when the power switch is turned on or when the door of the copier A is opened and then closed again. The time when the number of image forming operations is performed is set.

  If the power switch of the copying machine A is turned off during the drive control of the cleaning mechanism 303e by the cleaning control means 32 at the predetermined time, the cleaning mechanism 303e cannot return to the home position, and the position To stop. When the power of the copying machine A is turned on, the cleaning control unit 32 refers to the count value stored in the count storage unit 35. When the count value is not “0”, the cleaning mechanism 303e is in an operating state. The cleaning mechanism 303e is driven for a minimum required movement time to the retreat area consisting of the home position or the temporary home position, and the cleaning members 303f and 303g are retreated. When the temporary home position is retracted, when the predetermined time is reached again, the cleaning mechanism 303e is returned to the home position, and then the cleaning member 303f, 303g is executed by performing a cleaning operation. Is configured to reliably clean the discharge wire 303b.

  More specifically, when the count value is less than half of the first predetermined value, the counter 34 counts down the count value, and the cleaning control means until the count value becomes “0”. 32 drives and controls the cleaning mechanism 303e in the non-cleaning direction, and retracts the cleaning members 303f and 303g to the home position.

  When the count value is not less than half of the first predetermined value and less than the first predetermined value, the counter 34 counts up the count value, and the count value is set to “first predetermined value”. In the meantime, the cleaning control means 32 drives and controls the cleaning mechanism 303e in the cleaning direction, and retracts the cleaning members 303f and 303g to the temporary home position.

  When the count value is equal to or greater than the first predetermined value and less than half of the intermediate value between the second predetermined value and the first predetermined value, the counter 34 counts down the count value, and the count value Until the first predetermined value is reached, the cleaning control means 32 drives and controls the cleaning mechanism 303e in the non-cleaning direction, and retracts the cleaning members 303f and 303g to the temporary home position.

  When the count value is not less than half of the intermediate value between the second predetermined value and the first predetermined value, the counter 34 counts up the count value, and the count value becomes “second predetermined value”. In the meantime, the cleaning control means 32 drives and controls the cleaning mechanism 303e in the cleaning direction, and retracts the cleaning members 303f and 303g to the home position.

  When maintenance of the copier A is performed by a serviceman and the cleaning members 303f and 303g are assumed not to be in the evacuation area, the operator of the multi-function machine A is placed on the operation panel unit 4. By pressing a cleaning reset switch (not shown) for forcibly returning the cleaning member to the retracted area, the cleaning members 303f and 303g are driven to the retracted area including the home position or the temporary home position.

  More specifically, when the cleaning reset switch is pressed, the cleaning control unit 32 counts the count value counted by the counter 34 regardless of the count value stored in the count storage unit 35 included in the state storage unit 33. Until the first predetermined value is reached, the cleaning mechanism 303e is driven and controlled in the non-cleaning direction, the cleaning members 303f and 303g are driven to the retreat area as the home position, and the count storage means The count value is reset to “0”.

  Hereinafter, another embodiment will be described. In the above configuration, a corotron-type charging charger is used. However, a scorotron-type charging charger including a discharge wire and a grid may be used. In this case, a cleaning member that further cleans the grid is used. May be provided in the cleaning mechanism.

  In the above-described configuration, the image forming apparatus is configured to perform cleaning of the charging charger including the corona charger that uniformly charges the surface of the photosensitive member at a predetermined time. However, all or any of the above described image forming apparatus includes Each charger may be configured to perform cleaning at the predetermined time or at different predetermined times.

  In the above-described configuration, the cleaning of the discharge wire by the cleaning member is performed in one direction (cleaning direction), not performed in the other direction (non-cleaning direction), and the cleaning operation is completed by reciprocating. However, the configuration may be implemented in both directions. In this case, a temporary home position is not necessary, and both ends of the spiral shaft can be used as home positions of the cleaning mechanism.

  In the above-described configuration, the retraction area is provided at both ends of the spiral shaft. However, only one of the spiral axes may be the retraction area.

  In the above configuration, the count value counted by the counter at a predetermined time is configured to be counted up from the home position through the temporary home position until returning to the home position again as shown in FIG. As shown, it may be configured to count down, or may be configured to count up on the forward path and count down on the return path, or may be configured to count down on the forward path and count up on the return path. What is necessary is just to set it as the structure which can detect the operation state of the said control mechanism from the said count value memorize | stored in the memory | storage means.

  In the above-described configuration, the state storage means is constituted by a counter that counts the necessary cleaning time by the cleaning mechanism, and the cleaning control means detects that the cleaning mechanism is in an operating state based on the value of the counter when the power is turned on. Then, the cleaning mechanism is driven and controlled only for the minimum required movement time of the cleaning member to the retreat area calculated based on the value of the counter. However, the state storage means counts the necessary cleaning time by the cleaning mechanism. When the cleaning control means detects that the cleaning mechanism is operating based on the value of the counter when the power is turned on, the cleaning control means is based on the cleaning history of the cleaning member calculated based on the value of the counter. Thus, the cleaning mechanism may be driven and controlled for a time required to move to the retreat area after cleaning the uncleaned area.

  In the above-described configuration, the state storage means is constituted by a counter that counts the necessary cleaning time by the cleaning mechanism, and the cleaning control means detects that the cleaning mechanism is in an operating state based on the value of the counter when the power is turned on. Then, the cleaning mechanism is driven and controlled only for the minimum required movement time of the cleaning member to the retreat area calculated based on the value of the counter. However, the state storage means counts the necessary cleaning time by the cleaning mechanism. When the cleaning control means detects that the cleaning mechanism is in an operating state based on the value of the counter when the power is turned on, the cleaning mechanism is driven for the maximum required movement time of the cleaning member to the retreat area. It is good also as a structure to control.

  In the above-described configuration, the state storage means is constituted by a counter that counts the necessary cleaning time by the cleaning mechanism, and the cleaning control means detects that the cleaning mechanism is in an operating state based on the value of the counter when the power is turned on. However, the state storage means is configured to store a flag indicating whether or not the cleaning mechanism is in operation, and the cleaning control means is based on the flag stored in the state storage means when the power is turned on. The cleaning mechanism may be configured to detect that it is in an operating state.

  In the above-described configuration, by pressing the cleaning reset switch that forcibly returns the cleaning member arranged in the operation panel unit to the retreat area, the cleaning member is driven to the retreat area without performing cleaning by the cleaning member. Although it was set as the structure, it is good also as a structure which implements the cleaning by the said cleaning member and drives the said cleaning member to the said evacuation area | region.

  In the above-described configuration, when the cleaning member is driven in the cleaning direction, the cleaning is performed. However, the cleaning mechanism is provided with a mechanism that does not perform cleaning by the cleaning member, and is necessary even when driven in the cleaning direction. Accordingly, the cleaning member may not be used for cleaning.

  The above-described embodiments are merely examples of the present invention, and the scope of the present invention is not limited by the description, and the specific configuration of each part is appropriately changed within the scope of the effects of the present invention. It goes without saying that it can be done.

Functional block diagram of image forming control unit of copying machine Illustration of copier Illustration of the charger Illustration of the cleaning mechanism Explanatory drawing of the count value which the counter of a state memory means counts Explanatory drawing of the count value which the counter of the state memory | storage means in another embodiment counts

Explanation of symbols

30: Image formation control unit 31: Image formation unit 32: Cleaning control unit 33: Status storage unit 34: Counter 35: Count storage unit

Claims (5)

An image carrier, a corona charger installed around the image carrier, a cleaning mechanism including a cleaning member movable along a discharge wire stretched around the corona charger, and the cleaning mechanism at a predetermined time An image forming apparatus comprising a cleaning control unit that drives and controls a cleaning member between a retreat area and a cleaning area,
State storage means for storing the operating state of the cleaning mechanism is provided, and the cleaning control means detects that the cleaning mechanism is in an operating state by the state storage means when the power is turned on, and puts the cleaning member into the retreat area. An image forming apparatus for driving control.   The state storage means comprises a counter that counts the required cleaning time by the cleaning mechanism, and the cleaning control means detects that the cleaning mechanism is in an operating state based on the value of the counter when power is turned on. The image forming apparatus according to claim 1, wherein the cleaning mechanism is driven and controlled for a maximum required moving time of the cleaning member to the retreat area.   The state storage means comprises a counter that counts the required cleaning time by the cleaning mechanism, and the cleaning control means detects that the cleaning mechanism is in an operating state based on the value of the counter when power is turned on. The image forming apparatus according to claim 1, wherein the cleaning mechanism is driven and controlled for a minimum required movement time of the cleaning member to the retreat area calculated based on a value of the counter.   The state storage means comprises a counter that counts the required cleaning time by the cleaning mechanism, and the cleaning control means detects that the cleaning mechanism is in an operating state based on the value of the counter when power is turned on. 2. The drive mechanism of the cleaning mechanism is controlled based on a cleaning history of the cleaning member calculated based on a value of the counter, and the cleaning mechanism is driven and controlled for a time required to move to the retracted area after cleaning the uncleaned area. Image forming apparatus.   5. The switch device according to claim 1, further comprising a switch unit that forcibly returns the cleaning member to the retracted region, wherein the cleaning control unit drives and controls the cleaning member to the retracted region when the switch unit is operated. The image forming apparatus described in 1.

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