JPS58205177A - Cleaning device - Google Patents

Abstract

PURPOSE:To improve the efficiency of a cleaning member and to obtain stable cleaning effect, by varying the extent of movement of the cleaning member according to the size of a recording material. CONSTITUTION:When transfer paper of size A3 is used for copying, a trigger signal Q1 is inputted to an ICQ1 for a timer and a driving motor 12 for a cleaning web is driven by Q1, R4, R5, and C1 through R3 and Q4 for a specific time. Timer ICs Q2 and Q3 operate for different recording materials, e.g. transfer paper of sizes B4 and A4. The driving time of the driving motor 12 is t2-t1, t4-t3, and t6-t5 for the sizes A3, B4, and A4 respectively and the movement extent of the cleaning member is varied according to the recording size. Thus, the efficiency of the cleaning member is improved and the stable cleaning effect is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an image forming apparatus such as an electrophotographic copying machine or a facsimile machine, in which toner or toner attached to an object to be cleaned, such as a photoconductor, an image carrier having a photosensitive layer, or a rotating body such as a fixing roller, can be removed. This is a book about a cleaning device for removing and cleaning deposits such as paper dust.

Conventionally, in image forming apparatuses such as electrophotographic copying machines, cleaning members such as cleaners/growlers have been used to remove residual toner and other deposits on objects to be cleaned. Web cleaning devices are widely used. FIG. 1 is a side view schematically showing a case where such a conventional web cleaning device is used for cleaning a fixing device.

A pressure roller J made of an elastic material is rotatably supported to press a belt-shaped cleaning cube such as a non-woven fabric against a fixing roller / which is supported so as to be rotationally driven. The other end of the sheet is wound around the unwinding shaft 5 and is wound onto a rotationally driven winding shaft. Further, arrow 6 indicates the rotation direction of the fixing roller l, and arrow 6 indicates the feeding direction of the cleaning cube.

Copy paper with an unfixed image formed on the top surface should be placed in the entry guide g.
The unfixed image is fixed to the copy paper by heating and pressure welding. The paper is discharged to the outside through a pair of paper discharge rollers IO that are driven to rotate in opposite directions. At this time, some of the fixing roller / and the toner // forming the image on the copy paper adhere to the fixing roller l (offset phenomenon).

The toner adhering to the fixing roller is wiped off by a cleaning web which rotates in the direction of arrow 6 in the figure and moves at a much slower speed than the fixing roller.

As mentioned above, in the nib cleaning device, normally,
The amount of web feeding per unit time is set so that complete cleaning can be performed even when image forming operations (copying operations) are performed continuously. Therefore, it is sufficient to send the required amount for seven image forming operations (copying operations). However, in the conventional Kuep cleaner, the feeding timing is synchronized with the rotation of the main motor and the fixing roller. The rounding main motor rotates forward and backward to keep the surface potential of the drum constant, and the fixing roller rotates forward until the set temperature is reached to equalize the heat distribution between the upper and lower rollers. Therefore, it must operate even during periods other than actual copying operations.

Therefore, during these periods, the web is sent in vain.
If the web replacement interval of a web cleaning device is shortened, the service life of the web will be shortened. Such problems also occur in movable leaning members that are consumed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning device that can improve the drawbacks of the conventional cleaning device as described above, eliminate wasteful feeding of the cleaning member, and extend the replacement period. For this purpose, the present invention determines the cleaning member's feeding period depending on the size of the recording material on which an image is formed, determines the feeding amount for each size, and provides the optimum leaning member feeding amount. .

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 2 is a perspective view showing a web driving device according to an embodiment of the present invention. In Fig. 2, 2 is a clean web made of nonwoven fabric, etc., 3 is a pressure roller, and DA is a web winding shaft.
jf′i indicates the feed axis. A gear/J is fixed to the shaft end of the motor that is the driving source, and meshes with a gear/J fixed to the winding shaft of the webco. In this way, the take-up axis of the webco is made independent of the rotation of the photosensitive drum, fixing roller, etc. (not shown). B is a paper size detection means, and A receives a signal from detection means B17.
This is a control device that controls the amount of movement of the clamping member.

Figure 3 shows the motor/λ in the control bag FJIIA in Figure 1.
An example of a control circuit is shown below. In FIG. 3, Ql, Q2.
Q3 is the timer IC, H, 1~RI5 are the resistors C]~
C3 is a capacitor, and Q4 is a driver transistor. 11CQl when copying AJ size transfer paper
) The trigger signal is input to the timer ICQ and Q;+
``' + ''5 r The drive motor is driven during predetermined times R3 and Q4 by CI, and the QUEBCO is sent. ICQ2 for timer
．． Q3 uses different recording materials, such as transfer paper (size AII.

It operates in the same manner when copying Bp), and determines the driving time of the motor saw as shown in the timing chart in FIG. 4, in which time is represented on the horizontal axis.

In FIG. 1, when the copying machine is set to copy an A3 size original at time t1, the Ql+to'J signal is emitted as soon as the copying operation starts, and the aforementioned shifter (-
q - By circuit Ql, R4, Rs, C+ (t2
The motor is driven for a period of time t+).

Next, at time t3, when the copying machine is set to copy a BII size original, the copying operation starts and KQ2)
A rigger signal is issued and Q2. R.

According to R+o and C2tic, the motor is driven for a time (t<-ta). Similarly, at time t5, when the copying machine is set to copy an A-size original, the trigger signal Q3 drives the motor for a time (1 (, -ts)).This embodiment Among them, the longer the paper size in the feeding direction, the longer the operating time.

In addition, Q1, Q2, Q3) The rigger signal is AJ, for example.

B4 (, Al) This is generated by a switch activated when a paper feed cassette of each size is set in a copying machine and a signal during copying operation, or by a switch provided in the paper feed path of a copying machine. In the above embodiment, a good signal is received according to each size of the recording material, and the drive time of the cleaning motor is determined according to the time during which each size of recording material is in contact with the photosensitive drum or the fixing roller. According to the present invention, since the amount of movement of the cleaning member is changed according to the size of the recording material, the efficiency of the cleaning member can be increased and a stable cleaning effect can be obtained. .

[Brief explanation of the drawing]

Figure 1 is a schematic side view of the fixing device equipped with a web cleaning device, Figure 2 is a perspective view of the web drive device, Figure 3 is a control circuit diagram of the web drive motor, and Figure φ is the time chart of Figure 3. It is. /... Fixing roller Co... Cleaning web 3.
...Pressure roller Hiroshi...take-up) shaft! ...Feeding shaft Curling...Arrow t...Entry guide De...
Pressure roller lQ...Discharge roller //...Toner Lco...Motor /3. /'I...Gear A...
・Control device B...Paper size detection means Ql, Q2
, Qa...ICQ4 for timer...Transistor for driver R1'=R1B...Resistor C1, C
2, C3... Capacitor. Patent Applicant Canon Co., Ltd. Agent Arai Part 1 Figure 1

Claims (1)

[Claims] (l) A cleaning device (f) for removing and cleaning adherents such as toner and paper dust from the surface of the object to be cleaned by bringing a movable leaning member into pressure contact with the surface of the cleaning object; A cleaning loading device characterized in that the device receives a signal emitted from the determining device and includes a control device that increases or decreases the feed amount of the cleaning member in accordance with the size of the recording material.