JPH0474707B2 - - Google Patents

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 a photoreceptor, an image carrier having a photosensitive layer, and a rotating body such as a fixing roller, etc. The present invention relates to a cleaning device for removing and cleaning deposits such as toner and paper dust.

Conventionally, in image forming apparatuses such as electrophotographic copying machines, cleaning members such as cleaning rollers have been used to clean and remove residual toner and other deposits on objects to be cleaned. In particular, web cleaning involves cleaning with a cleaning web made of nonwoven fabric or the like. The device is widely used. FIG. 1 is a side view schematically showing a case where such a conventional web cleaning device is used to clean a fixing device.

Fixing roller 1 supported so as to be rotationally driven
A pressing roller 3 made of an elastic material is rotatably supported to press a belt-shaped cleaning web 2 such as a non-woven fabric onto the cleaning web 2.
is wound around a feed-out shaft 5, and is wound onto a rotationally driven wind-up shaft 4 from the other end of the unwound end. Further, an arrow 6 indicates the rotation direction of the fixing roller 1, and an arrow 7 indicates the direction in which the cleaning web 2 is fed. The copy paper with the unfixed image formed on its upper surface passes over the entry guide 8, and passes through the fixing roller 1, which has a heat source inside, and the pressure roller 9, which is in pressure contact with the fixing roller 1 and rotatably supported.
The unfixed image is fixed to the copy paper by heating and pressure, and is ejected to the outside through a pair of ejection rollers 10 which are driven to rotate in opposite directions. At this time, some of the toner 11 forming the image on the fixing roller 1 and the copy paper adheres to the fixing roller 1 (offset phenomenon). Toner 11 attached to fixing roller 1
is wiped off by a cleaning web 2 which rotates in the direction of arrow 6 in the figure and moves at a much slower speed than the fixing roller 1.

In the above-mentioned web cleaning device, the web feed amount per unit time is usually
The setting is such 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 each image forming operation (copying operation). but,
In conventional web cleaners, the timing of feeding is synchronized with the rotation of the main motor, fixing roller, etc. Therefore, the 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. It must also operate during periods other than actual copying operations.

Therefore, during these periods, the web is fed wastefully, which shortens the interval between web replacements of the web cleaning device, thereby shortening its lifespan. Such problems also occur in movable cleaning 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 conventional cleaning devices as described above, eliminate wasteful feeding of cleaning members, and extend the replacement period. To achieve the above object, the present invention is a cleaning device that removes toner and paper dust from an object to be cleaned using a movable cleaning member, and is characterized in that the amount of feed of the cleaning member is controlled according to the size of the recording material. That is.

Embodiments of the present invention will be described below 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, reference numeral 2 indicates a cleaning web made of nonwoven fabric or the like, 3 a pressure roller, 4 a web winding shaft, and 5 a delivery shaft. A gear 13 is fixed to the shaft end of a motor 12 which is a drive source, and meshes with a gear 14 fixed to a winding shaft 4 of the web 2. In this way, the winding shaft 4 of the web 2 is made independent of the rotation of the photosensitive drum, fixing roller 1, etc. (not shown). B is a paper (recording material) size detection means, and A is a control device that receives a signal from the detection means B and controls the amount of movement of the cleaning member.

Fig. 3 shows the motor 1 in the control device A of Fig. 2.
An example of the control circuit of No. 2 is shown below. In Figure 3, Q ₁ ,
Q ₂ , Q ₃ are timer ICs, R ₁ to R ₁₅ are resistors, C ₁ to
_C3 is a capacitor, and _Q4 is a driver transistor. When copying A3 size transfer paper, the Q ₁ trigger signal is input to the timer ICQ ₁ .
Time predetermined by Q ₁ , R ₄ , R ₅ , C ₁
A drive motor 12 is driven via R ₃ and Q ₄ to feed the web 2. for timer
ICQ ₂ and Q ₃ operate in the same way when copying different recording materials, such as transfer paper (sizes A4 and B4), and the motor 12 operates as shown in the timing chart shown in FIG. 4, where the horizontal axis represents time. This determines the driving time.

In Fig. 4, when the copying machine is set to copy an A3 size document at time _t1 , the _Q1 trigger signal is generated at the same time as the copying operation starts, and the timer circuits _Q1 , _R4 , _R5 , _C1 described above ( _t2 − _t1 )
The motor 12 is driven for a period of time. Next, at time _t3 , when the copying machine is set to copy a B4 size original, a _Q2 trigger signal is generated at the start of the copying operation, and _Q2 , _R9 , _R10 , and _C2 cause ( _t4 -
The motor 12 is driven for a time t ₃ ). Similarly, when the copying machine is set to copy an A4 size document at time _t5 , the trigger signal _Q3 drives the motor 12 for a time ( _t6 - _t5 ). In this embodiment, the longer the paper size in the feeding direction, the longer the operating time.

The Q ₁ , Q ₂ , Q ₃ trigger signals are, for example, A3, B4,
Switches that operate when each A4 size paper cassette is set in the copying machine and signals during copying operation,
Alternatively, it is detected and generated by a switch provided in the paper feed path of the copying machine.

In the above embodiment, the control circuit is configured to receive a signal corresponding to each size of the recording material and determine the drive time of the cleaning web motor 12 according to the contact time between each size of recording material and the photosensitive drum or fixing roller. It is set up. In 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 drawings]

Fig. 1 is a schematic side view of a fixing device equipped with a web cleaning device, Fig. 2 is a perspective view of a web drive device, Fig. 3 is a control circuit diagram of a web drive motor, and Fig. 4 is a time chart of Fig. 3. It is. 1... Fixing roller, 2... Cleaning web, 3... Pressure roller, 4... Winding shaft, 5...
...Feeding shaft, 6, 7...Arrow, 8...Entry guide, 9...Pressure roller, 10...Discharge roller, 1
1...Toner, 12...Motor, 13, 14...
Gear, A...control device, B...paper size detection means, _Q1 , _Q2 , _Q3 ...IC for timer, _Q4 ...transistor for driver, _R1 to _R15 ...resistance, _C1 ,
C ₂ , C ₃ ... Capacitors.

Claims (1)

[Scope of Claims] 1. A cleaning device that removes toner and paper dust from an object to be cleaned using a movable cleaning member, characterized in that the amount of feed of the cleaning member is controlled according to the size of the recording material. cleaning equipment.