JPH0719090B2 - Abnormality detection device for image forming apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to a charging system technology in an electrophotographic copying machine, a printer using an electrostatic printing method, a facsimile, and the like.

[Prior Art] If toner or foreign matter adheres to the charge wire of a charger of a photoconductor incorporated in an electrophotographic copying machine or the like, discharge becomes unstable and white stripes or white bands may occur in a copy image. Therefore, maintenance and management for cleaning the charge wire on a regular basis have been performed conventionally. At that time, a motor or the like is used to automatically move the cleaning member of the wire, and the moving member that holds the cleaning member by the mechanism starts moving from its home position, reverses after a certain time elapses, and then returns to the home position again. A movement pattern called "returning to" was adopted, and counting was started from the time when this movement started, and it was considered abnormal if the moving member did not return to the home position within a certain time. However, with this method, there is an abnormality in the case where the cleaning member returns to the home position without moving the entire stroke commensurate with the effective length of the wire, or when it takes longer than the normal reciprocating elapsed time due to overload. Is impossible to detect.In the former case, the wire cleaning is insufficient and the copy image is adversely affected. In the latter case, the motor, drive mechanism and parts are damaged due to overload. Produce results.

[Object] In view of the inconvenience inherent in the automatic cleaning unit of the charging device as described above, the present invention detects an abnormality of the automatic cleaning device of the charge wire, analyzes and displays the content of the abnormality.
Further, another object of the present invention is to provide an abnormality detecting device for an image forming apparatus which disables copying due to an abnormality, guarantees an image and prevents damage to parts, but does not disable copying in the case of a preliminary abnormal condition.

[Structure] In order to achieve the above-mentioned object, the device of the present invention has the constitutional requirements as described in the section of the claims. Therefore, one embodiment of the device of the present invention will be described with reference to the accompanying drawings. Before that, the configuration and operation of a concrete example of the cleaning means for the charge wire in which the device of the present invention is installed will be clarified and placed.

FIG. 1 is a perspective view of a charging charger to which the device of the present invention is applied, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a plan view of a part thereof, in which 1 is a sectional view. A casing 2 in the shape of a letter is an end block (rear) fixed to one end of the longitudinal axis of the casing, and is located between the end block (front) 9 fixed to the other end of the casing 1 along the longitudinal axis of the casing 1. Further, the charge wire 4 is stretched around the casing 1 in an electrically insulating manner. Reference numeral 3 denotes a guide for a cleaning moving member provided on the inner bottom surface of the casing 1 along the longitudinal axis. A plastic moving portion 8 having a member 6 for holding a cleaning member (cleaning pad) 7 attached thereto and a moving portion rotation center axis 17 is loosely fitted. Reference numeral 5 is a drive wire for moving the moving portion 8 along the guide 3, both ends of which are biased and connected to both sides of the moving portion 8 to form an endless belt, and one end of which is pivotally supported by the end block 9. The worm wheel drive pulley 12 and the other side of the worm wheel drive pulley 12 are respectively suspended and driven by a driven pulley axially supported in the end block 2. 6 is a holding portion of the cleaning member 7, which is made of plastic and is screwed to the moving portion 8 so that it can be attached to and removed from each other, and is designed for convenient replacement of the dirty cleaning member. 10 is a motor for driving the moving unit 8, which is installed in the end block 9,
The output shaft is linked to a worm wheel 12 with a drive pulley via a worm gear 11.

Reference numeral 13 denotes a home position detection sensor of the moving unit 8, which works in conjunction with the detection filler of the moving unit 8 to open the electric circuit of the drive motor 10.

The cleaning device having the above-described mechanism operates as follows.

In FIG. 3, <State 1> in the drawing is the position of the cleaning member within the effective charging width of the charge wire, and the moving portion 8 is counterclockwise about the rotary shaft 17 due to the step difference in the mounting position of the drive wire 5. The charge pad 4 is held by the cleaning pad 7 while being inclined in the direction (arrow direction). In this state, the moving part 8 is reciprocated along the wire 4 to clean the wire 4. At that time, the drive motor 10 is controlled so as to rotate in the forward direction when the moving section 8 moves forward, and reversely rotate in the backward direction.

In <state 2>, the moving portion 8 is outside the effective charging width and is in a non-cleaning state. When the moving part 8 advances to the home position 16 (the driving motor 10 is rotating in the reverse direction), it comes into contact with the end block (front) restricting part 9 ', and when it further returns, it rotates clockwise about the rotary shaft 17 ( It rotates in the direction of the arrow) and at this time the cleaning member 7
Is released from the charge wire 4 and released. At the same time, the moving unit 8 presses the detection filler 14 against the spring 15 to turn on the sensor 13 and stop the motor 10.

An embodiment of the abnormality detecting means of the present invention applied to the above cleaning device will now be described with reference to the flowchart.

[Embodiment] FIGS. 4 to 6 show control flowcharts of the motor 10 for driving the cleaning member of the present invention. The motor is controlled by the CPU and driver circuit not shown in this flowchart.

FIG. 4 is a flowchart of the initial check when the main switch of the machine is turned on. In the figure, H
P.Sw is the home position switch of the cleaning member, and A is the set count value (timer value). At that time, normally, the cleaning member occupies the home position and only resets the counter.However, when the main switch is turned off while the motor 10 is rotating, the cleaning member stops in the charger case. When the main switch is turned on again, the motor 10 is rotated in the reverse direction according to the flowchart, and the cleaning member is moved to the home position. The count value (A) set at this time is the time required for the maximum movement distance of the cleaning member +
It is set as a margin time, and even if it exceeds that time, H
If P.Sw does not turn ON, lock the cleaning member or
Judge that it is 10 mag and set up abnormal club 1.

5 and 6 go through the initial routine,
FIG. 5 is a flowchart for operating in the routine after the copy standby state, and FIG. 6 is a flowchart for normal rotation and FIG. 6 is for reverse rotation. When the motor ON signal (start 2) in FIG. 5 is received from the outside, if the reverse rotation flag is checked, if it is forward rotation (outward path), proceed as it is, and if it is reverse rotation, start 3 (6th).
Figure).

First, since the normal rotation is normally started, the normal rotation is started according to the flowchart (shown in FIG. 5). Then HP.Sw O
Check N / OFF and HP.Sw is ON for a certain time (C)
If left as it is, it is determined that the cleaning member cannot start from the home position due to motor lock or the like, and the abnormality flag 2 is set.

When the cleaning member starts normally, the motor 10 is stopped after the set count value (B), that is, the time required for the maximum movement distance + the allowance time, the reverse rotation flag is set, and the counter is reset. Exit from the flowchart. When the routine is entered again, the reverse rotation flag is set, so the routine proceeds to START 3.

FIG. 6 is a reverse flow chart. Looking at the reverse rotation flag, it comes in here and starts reverse rotation of the motor 10. When entering here, the home position HP.Sw is checked every time, and the count value (F) that is set, that is, the time required for the maximum moving distance + the margin time, is set and the abnormality flag 5 is set.

When HP.Sw turns on after a certain time, the content of the count is checked. At this time, if D <counter <E, it is determined that there is no abnormality, and if D or less, abnormality flag 3 is set, and if E or more, abnormality flag 4 is set.

As described above, by setting the abnormality flag corresponding to each abnormality, the contents can be displayed on the operation unit or the like to notify the serviceman of the abnormality.

The contents are as follows: (a) Abnormal flag 1; The cleaning member is stopped midway, locked, or cannot be pulled at the time of initializing.

(B) Abnormal flag 2; even if the motor 10 is turned on, the motor does not rotate, or HP.Sw is out of order.

(C) Abnormality flag 3; The cleaning member returns abnormally quickly, that is, the cleaning member is caught in the middle of movement and returned without reaching the maximum movement distance. The copy image is adversely affected.

(D) Abnormal flag 4; Return of the cleaning member is abnormally slow. That is, the movement of the cleaning member is overloaded and damages the motor 10 and the like.

(E) Abnormal flag 5; the cleaning member is stuck and does not reverse.

Therefore, the check items of the service person can be limited in advance, which leads to a reduction in service time.

Among the abnormalities (a) to (e), (a),
Regarding (b) and (e), it is expected that the motor 10 will be locked, and if left as it is, it may lead to a motor burnout accident, so it is necessary to immediately stop the machine and call a service person when an abnormality is detected. However, in the cases of (c) and (d), since the reciprocating motion is performed although it is not a normal motion, the accident as described above does not occur. Therefore, it is more beneficial for the user to make a copy and check it at the time of maintenance performed by a service person on a regular basis, and to improve it rather than being unable to make a copy immediately.

[Effect] According to the device of the present invention, (1) Since the check is performed at each step of the motor control for driving the cleaning member, even if a failure such as a motor lock occurs, the detection time is short. Little damage to corner parts.

(2) It is possible to determine whether each abnormality mode is abnormal or not, and it is possible to limit the check items for the failure of the service person, which leads to a reduction in service time.

(3) It is possible to check whether or not all the dirt on the charge wire has been cleared, which leads to the guarantee of the copy image.

(4) Copying is prohibited only in the case of an abnormality that may cause a specific accident, and copying is possible in other abnormalities, thereby protecting the user's benefit.

That is, the special action and effect can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of a charging charger to which the device of the present invention is applied, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a plan view of the charger for explaining an operating state of a cleaning member, and FIGS. FIG. 6 is a control flow chart of the cleaning member driving motor of the present invention. FIG. 4 is a flow chart of an initial check when the main switch of the machine is turned on, FIG. 5 is a flow chart of forward rotation, and FIG. 6 is a flow chart of reverse rotation. It is a flowchart. 1 ... Casing, 2 ... End block (rear), 3 ...
... moving member guide, 4 ... charge wire, 5 ... moving member driving wire, 6 ... cleaning member holding portion, 7 ... cleaning member, 8 ... moving member, 9 ... end block (front), 10
...... Drive motor, 11 …… worm gear, 12 …… worm wheel with drive pulley, 13 …… home position detection sensor, 14 …… detection filler, 15 …… filler return spring, 16 …… home position, 17… … Rotating shaft for moving part.

Claims (2)

[Claims] 1. A charging device comprising a cleaning mechanism in which a charge wire is sandwiched between cleaning members, and the member is automatically moved along the wire, and a charging means, wherein the cleaning member is a home. The home position detecting means for detecting the presence of the position, the counting means for starting the counting by starting the operation of the cleaning member moving means, and the copying operation are prohibited based on the count number by the counting means and the signal of the home position detecting means. And an abnormality detection device for an image forming apparatus, which includes two types of abnormality display devices which are abnormal but which do not prohibit copying operation. 2. If the cleaning member is not in the home position when the cleaning member moving means starts to operate, the cleaning member is started to move back to the pom position, and the count number is
If the home position is not returned before the set value of the time required to move the cleaning member's maximum moving distance + the margin time is reached, a copy operation prohibition error display is displayed, and the cleaning member returns to the home position at the start of operation. In the case where the cleaning member remains in the same position even after a certain time or more, the copying operation prohibition abnormality display is displayed, and after the cleaning member starts moving from the home position, the moving means reverses to move the cleaning member to the maximum position. Abnormality that does not prohibit the copying operation when returning to the home position at a time that is abnormally smaller than the set count, which is the time required to move the moving distance + the margin time, or when returning to the home position, which is abnormally larger than the set count. A message is displayed and the size of the cleaning member is longer than the maximum moving distance + the margin time. Abnormality detection device of an image forming apparatus according paragraph 1 claims made be configured to carry out the copying operation prohibited abnormal display if not return in cement.