JP2003202734A - Charge wire cleaning device for image forming apparatus - Google Patents

Abstract

(57) [Summary] [PROBLEMS] An image forming apparatus of good image quality by performing a charger cleaning when a machine is infrequently used, thereby eliminating a waiting time at the time of image output, and always enabling stable and uniform discharge. Provided is a wire cleaning device for a battery charge. A charge wire (2) for charging an image carrier by corona discharge, a cleaning pad (3) for cleaning the charge wire (2), and a unit for controlling cleaning of the charge wire (2). The cleaning control means counts the time after the end of printing from the time when the print command is no longer sent, and when the elapsed time indicated by the counter value reaches the preset time, or when the value of the print number counter is the preset number of sheets. , The cleaning operation of the charge wire 2 is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge wire cleaning device for an image forming apparatus such as a facsimile, a printer, a copying machine, and more particularly to a device having means for automatically cleaning a charge wire in a charger unit. .

[0002]

2. Description of the Related Art The uniformity of charging due to corona discharge on a photoconductor in an image forming apparatus has a great influence on the quality of an image, so that the discharge characteristic is stable. desirable. Contaminants such as toner, paper dust, and dust are floating inside the image forming apparatus, and as the image formation is repeated, they adhere to the charge wire that constitutes the charger (charger), which lowers the discharge efficiency. Discharge unevenness occurs and a good image cannot be obtained.

Therefore, various charging wire cleaning devices have been proposed. For example, Japanese Patent Laid-Open No. 6-186827 discloses a technique of cleaning the charge wire after the jam processing is completed. Further, Japanese Patent Laid-Open No. 5-323742 discloses a technique for cleaning the charge wire before the image condition correcting operation. As can be seen from these techniques, there are various cases of starting conditions for cleaning the charge wire, and charge cleaning control is performed according to each machine and device.

Further, Japanese Patent Application Laid-Open No. 11-143307 proposes to control the execution condition of the charge wire cleaning operation based on the toner consumption amount information or the number of sheets information. Further, as a well-known technique, control for cleaning the charger when the power is turned on or when image formation is completed (when a print job is completed) is used.

In these techniques, the emphasis is on the automation of the cleaning operation, and it is intended to stabilize the image quality by performing the cleaning operation periodically and with time. The above-mentioned char wire cleaning control is effective as a means for preventing the charge wire from being contaminated and stabilizing the quality, but charge wire cleaning generally requires the cleaning unit to reciprocate with respect to the wire. There is a problem that it generally takes time to perform one cleaning. Therefore, it is possible that the image forming apparatus cleans the charger when the machine is turned on by the user and when the machine is started up, and is in a waiting state for a long time.

Therefore, according to the present invention, by cleaning the charger when the machine is infrequently used, the waiting time at the time of image output can be eliminated, and stable and uniform discharge can be always performed for an image forming apparatus of good image quality. It is an object to provide a wire cleaning device for charging.

[0007]

In order to achieve the above object, a charge wire cleaning device for an image forming apparatus according to claim 1 of the present invention includes a charge wire for charging an image carrier by corona discharge, and In an image forming apparatus having a cleaning unit that cleans a charge wire and a unit that controls the cleaning of the charge wire, the cleaning control unit causes the cleaning unit to notify the cleaning unit after a predetermined time has elapsed from the end of the image forming operation. The feature is that the charge wire is cleaned.

In order to achieve the above object, the charge wire for charging the image bearing member by corona discharge, the cleaning means for cleaning the charge wire, and the preset predetermined time are provided. In an image forming apparatus having a preheating mode shifting unit that shifts to a preheating mode in which an image forming mode capable of performing an image forming operation by being left is released to lower the temperature of a fixing unit to save power, the preheating mode shifting unit is: It is characterized in that the cleaning means is made to clean the charge wire at the time of shifting to the preheating mode.

In order to achieve the above object, the third aspect of the present invention is, in the image forming apparatus of the first or second aspect, a sheet number counting means for counting the number of output sheets for each image, and the sheet number counting means. And a non-volatile storage unit for storing the count value of the charge wire, and the charge wire cleaning control is activated only when the number-of-sheets count value counted by the number-of-sheets count unit reaches a preset value. And

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing a configuration of an embodiment of a wire cleaning device for a charge for an image forming apparatus according to the present invention, and FIG. 2 is a side sectional view of the same.

In the figure, 1 is a charger main body, 2 is a charge wire stretched in the charger main body 1, 3 is a cleaning pad pressed against the charge wire 2, and 4 is a reciprocating movement that supports the cleaning pad 3 at the bottom. A slider, which is a body, 5 is a feed screw which is arranged inside the slider 4, and which is a transfer body for moving the slider 4 in parallel with the charge wire 2, 6 is a driven gear fixed to an end of the feed screw 5, and 7 is a driven gear. A drive gear that meshes with the driven gear 6, 8 is a motor that rotationally drives the drive gear 7, 11 is a rear end block fixed to both ends of the charger body 1, and 12 is a front end block.

The slider 4 is attached to a rotatable feed screw 5 and reciprocates along the feed screw 5 when the feed screw 5 rotates in the forward and reverse directions. When the slider 4 is fed out by the rotation of the feed screw 5, the slider 4 is guided by the bent portion 1 a of the charger body 1, and the cleaning pad 3 sandwiches the charge wire 2. The charge wire 2 is cleaned by the reciprocating movement of the cleaning pad 3 in this state.

The feed screw 5 is rotated in the forward and reverse directions by driving the end driven gear 6 of the feed screw 5 by the drive gear 7 mounted on the output shaft of the motor 8, that is, by the forward and reverse rotation of the motor 8.

FIG. 3 is a control block diagram of this embodiment. In the figure, 31 is a CPU of an image forming apparatus equipped with the charge wire cleaning apparatus of the present embodiment, 32 is an intermediary I / F and image data reception / transmission between the host computer 33 in the image forming apparatus. A controller is a ROM which is a read-only memory that stores a control program for the image forming apparatus, a 35 is a RAM which is a readable and writable memory used in the control program, and a reference numeral 36 is a power source of the image forming apparatus. EEPROM is a non-volatile memory that can hold data, 37 is a motor drive circuit for driving the motor 8, 38 is a current change in the motor drive circuit 37, and the information is motor locked state (High). It is a current detection circuit that converts an output or a lock signal of a motor drive state (Low) output.

FIG. 4 is a flow chart of the charger cleaning operation of this embodiment. This flow starts depending on the charger cleaning conditions described later, and the motor drive circuit 3
The motor 7 is output to rotate the motor 8 forward (S1). As a result, the slider 4 cleans the charge wire 2 in the rearward direction from the front home position. When the slider 4 reaches the rear end block 11, the motor 8 is locked, so that the voltage corresponding to the restricted current is output to the CPU 31 as a lock signal.

The CUP 31 starts the timer 1 from the time when the normal rotation of the motor 8 is started (S2), and monitors the time T until the lock signal is in the locked state (High output) (S3). When the restraint state is detected, it is determined that the slider 4 has reached the rear end block 11, and C
Since the PU 31 cleans the return path, the output of the motor 8 is once stopped (S4). If the lock signal is not detected in step S3 and the timer value has elapsed for the specified time or longer (for example, 30 seconds), it is determined that the operation is abnormal (S5), and the abnormal process (S7) is performed and the process ends.

The return path cleaning operation is performed in steps S1 to S1 described above.
The same steps as S7 are performed during the motor 8 reversing operation. Finally, when it is determined by the lock signal that the slider 4 has reached the front end block 11, the CPU 3
Looking at the count time of the timer 2 started from the time when the motor 1 starts reversing the motor 8, if it is not within 4 seconds, for example, it is determined that (S14) is a normal end, the cleaning operation is ended, and the controller 32 causes the printer Send that you are ready.

If the time is within 4 seconds, for example,
Since the cleaning pad 3 is caught by the dirt attached to the charge wire 2 and the slider 11 cannot move, or the lock signal is fixed to High and the control steps S3 and S10 are immediately passed, an abnormal operation is detected. The determination is made (S15), the abnormality process 1 (S7) is performed, and the operation is ended.

In the abnormality processing, the cleaning operation is stopped after the abnormality (S7, S13, S15) detected during the charger cleaning operation processing is detected, and the image forming apparatus is disabled. Further, the controller 31 is notified of the error content, the display unit message as shown in FIG. 8 is displayed, and the user is urged to call the maintenance staff.

FIG. 5 is a flowchart for counting the number of printed sheets in the present embodiment. The CPU 31 always waits for a print command from the controller 32 in a standby state where no operation is performed (S1), and when a processing command for one sheet arrives, the number counter n is incremented by one sheet (S2).
Since this number count value n + 1 is used as a condition for starting a charger cleaning operation described later, it is written and stored in the EEPROM 36 which can be stored even when the power is turned off (S
3). An image forming process is performed based on the image data and print parameters from the controller 32 (S4). In the case of printing a plurality of sheets, this cycle (S1 to S4) is continuously performed. When the print command from the controller 32 is interrupted after entering this print cycle, the standby mode is entered, and the process proceeds to the charger cleaning start flow of FIG. 6 or 7 (S5).

FIG. 6 is a flowchart for starting the first charger cleaning. In FIG. 5, when the controller 32 starts the time count after printing is finished when the print command is no longer sent, and the elapsed time indicated by the counter reaches a preset time Mp (S
1) Further, when the value of the print number counter of FIG. 5 reaches a preset number Np (S2), the print number counter is reset to 0 (S3), and the above-mentioned charger cleaning operation is performed (S4).

FIG. 7 is a flowchart for starting the charger cleaning at the time of transition to preheating. The preheat mode is a mode in which the fixing temperature is controlled by being lowered by a constant temperature (for example, 10 ° C.) to save power consumption. The shift to this mode is made automatically after a certain time has elapsed since the key input on the operation unit or the printing was stopped. This mode is released by key input on the operation unit or by restarting printing. That is, the controller 3 in FIG.
When the preheat transition time counting is started from the time when the print command is not sent from 2 and the elapsed time indicated by the counter reaches the preset time (S1), the value of the print number counter in FIG. When the preset number Np is reached (S2), the print number counter is reset to 0 (S3), and the above-described charger cleaning operation is performed (S4). After cleaning the charger, the temperature of the fixing heater is lowered as described above to shift to the preheating mode (S
5).

[0023]

As described above, the charge wire cleaning device for an image forming apparatus according to the first and second aspects of the present invention is as follows.
By cleaning the charge wire during the time when the equipment is not operating as much as possible, there is an effect that the waiting time at the time of image output at the time of rising can be eliminated and the downtime of the image forming apparatus can be reduced.

As described above, the charge wire cleaning device for an image forming apparatus according to a third aspect of the present invention performs the cleaning of the charge wire every time the number of image-formed sheets reaches a certain number, so that the common operation is achieved. In addition to the effect, there is an effect that the dirt of the charge wire is periodically removed and a stable image quality is obtained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a configuration of an embodiment of a wire cleaning device for a charge for an image forming apparatus according to the present invention.

FIG. 2 is a side sectional view of the same.

FIG. 3 is a control block diagram of an embodiment of a wire cleaning device for a charge for an image forming apparatus according to the present invention.

FIG. 4 is a flowchart of the same charger cleaning operation.

FIG. 5 is a flowchart of a number-of-sheets counting process during printing.

FIG. 6 is a flowchart for starting the first charger cleaning.

FIG. 7 is a flowchart for starting charger cleaning at the time of transition to preheating.

FIG. 8 is a diagram showing a message display example on a display unit.

[Explanation of symbols]

1 Charger body 2 charge wire 3 cleaning pad 4 slider 5 lead screw 6 Driven gear 7 drive gear 8 motor 11 Rear end block 12 Front end block 31 CPU 32 controller 33 Host computer 34 ROM 35 RAM 36 EEPROM 37 Motor drive circuit 38 Current detection circuit

Claims (3)

[Claims] 1. A charge wire cleaning device for an image forming apparatus, comprising: a charge wire for charging an image carrier by corona discharge; a cleaning means for cleaning the charge wire; and a means for controlling the cleaning of the charge wire. ,
The charge wire cleaning device for an image forming apparatus, wherein the cleaning control unit causes the cleaning unit to clean the charge wire after a predetermined time has elapsed from the end of the image forming operation. 2. A charge wire for charging an image carrier by corona discharge, a cleaning means for cleaning the charge wire, and an image forming mode in which an image forming operation can be performed by leaving the image carrier for a preset time. In a charge wire cleaning device for an image forming apparatus having a preheating mode transition means for transitioning to a preheating mode for lowering the temperature of the fixing portion to save power, the preheating mode transition means is configured to operate on the cleaning means at the time of transition to the preheating mode. A charge wire cleaning device for an image forming apparatus, characterized in that the charge wire is cleaned. 3. A charge wire cleaning device for an image forming apparatus according to claim 1 or 2, wherein a number counting means for counting the number of output sheets for each image, and a nonvolatile storage means for storing the count value of the number counting means. A cleaning means for the charge wire, wherein the cleaning control of the charge wire is started only when the number-of-sheets count value counted by the number-of-sheets counting means reaches a preset value. Device placement.