JPS6071407A - Endless belt driving device - Google Patents

Abstract

PURPOSE:To make a zigzag motion width reducible, by setting the initial deflecting position of a zigzag correction roller in response to a peripheral length differential in an endless belt, in case of a device which sets one of plural rolles being rolled with the endless belt down to the zigzag correction roller in design. CONSTITUTION:A belt sensitizer body 6 in a copying machine is stretched in span among a driving roller 11, a zigzag correction roller 12 and each of driven rollers 13 and 14, while the zigzag motion of the belt sensitizer body 6 is detected in accordance with output of a pair of photosensor (unillustrated herein) in a sensor part 24 detecting a conductive zone installed at both sides of the belt sensitizer body 6. At this juncture, in time of zigzag detection, a lead screw is rotated by a step motor 36 via miter gears, and a deflecting body 37 is rocked in shafting via a slider being screwed in this lead screw whereby the zigzag correction roller 12 is rocked up and down with other end side as a fulcrum, thus zigzag motion is eliminated. Then, in a manner conformable to a peripheral length differential at both sides of the belt, the initial deflecting position of the roller 12 is made so as to be set down.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a device for endlessly driving an endless belt while correcting its meandering.

[Prior Art] In general, when it is necessary to hold the conveyed object on a flat surface, such as when conveying a sheet-like object (two sheets of paper, etc.), an endless belt (hereinafter referred to as an endless belt) is used as a conveyance means. In many cases, a conveyance device using a

In such a conveyance device, an object is not placed (supported).

Since the endless belt itself forms a flat surface, it is relatively easy to hold an object on a flat surface.

FIG. 1 shows a drive unit for a belt photoreceptor used in an electrostatographic copying machine or the like that uses a so-called belt photoreceptor as a sensor.

In this drive unit, the belt photoreceptor OB is stretched between the drive roller R1 and the driven rows 582 to 84, and the belt photoreceptor OB is driven in the direction of the arrow.

This device brings a transfer paper into close contact with a belt photoreceptor OB, transfers the toner image formed on the belt photoreceptor onto the transfer paper, and then conveys the transfer paper to a fixing section.

By the way, as is well known, in such an endless belt drive device, so-called meandering development occurs in which the endless belt shifts in its width direction.

The main reasons for this are that, for example, in the apparatus shown in FIG. It is mentioned that they are not parallel.

Therefore, conventionally, for example, the roller R2 has a function of a meandering correction roller to correct the meandering of the belt photoreceptor OB.

That is, a meandering detection means is provided to detect that the belt photoreceptor OB has meandered, and when meandering occurs, the roller R2
The axis of the belt photoreceptor O is deflected in the opposite direction to the meandering direction.
B is moved, thereby correcting the meandering of the belt photoreceptor OB.

By the way, as mentioned above, there are two main causes of meandering,
Meandering development due to these causes may combine to increase the amount of meandering, and therefore, the roller R2 may be deflected suddenly and greatly in order to correct the meandering of the belt photoreceptor OB.

Since each copying process station is provided close to the belt photoreceptor OB, if the roller R2 is suddenly deflected greatly as described above, the belt photoreceptor OB
The moving speed of the belt increases, and the surface and side edges of the belt come into contact with the casing, side plate, etc. of the device forming the station, and as a result, the belt photoreceptor may be damaged.

In recent years, high-speed copying machines using belt photoreceptors and having a copying speed of about 150 sheets/min have been realized. In such a high-speed copying machine, since the process speed is high, it is necessary to drive the belt photoreceptor at high speed, and therefore the above-mentioned disadvantages become noticeable.

In addition, such inconveniences are not limited to the above-mentioned copying machine.
Similar problems occur in other devices that utilize endless belt drive devices.

[Objective] The present invention was made in order to eliminate the above-mentioned disadvantages, and an object of the present invention is to provide an endless belt drive device that can reduce the amount of deflection of the @ line correction roller.

[Configuration] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 shows a copying machine port according to an embodiment of the present invention.

In the figure, 1 is a contact glass on which the original is placed;
2 is a light source that moves in the direction of the arrow to scan the document surface on the contact glass 1; 3 is a through lens that moves in the direction of the arrow in synchronization with the light source 2 and focuses the reflected light from the contact glass 1; 4 and 5; are first and second guides that guide the light that has passed through the through lens 3 to the exposure station of the belt photoreceptor 6.
It's a mirror.

7. 8, 9 and 10 are flatness maintenance plates for maintaining the flatness of the belt photoreceptor 6 in each process station of cleaning, charging, exposure and development; 11 is a drive roller; 12 is a flatness maintenance plate for maintaining the flatness of the belt photoreceptor 6; Meandering correction rollers 13 and 14 for correcting meandering are driven rollers, and the belt photoreceptor 6 has flatness maintaining plates 7, 8, 9, 10,
Drive roller 11, meandering correction roller 12, driven roller 13
, 14.

15 is a charger that uniformly charges the surface of the belt photoreceptor 6; 16 is a transfer charger that charges the transfer paper and brings it into close contact with the belt photoreceptor 6, thereby transferring the toner images 1 to 1; and 17 is a transfer charger that charges the transfer paper. This is a separate charger that is separated from the belt photoreceptor 6.

21 is a developing section that develops the electrostatic latent image formed on the belt photoconductor 6 with toner; 22 is a fixing section that fixes the toner image on the separated transfer paper to the transfer paper; 23 is a section that remains on the belt photoconductor 6; This is a cleaning section that removes toner and residual charges.

24 is a sensor unit that detects meandering of the belt photoreceptor 6 and the timing to start the copying process.

25 and 26 are guide plates that guide the transfer paper to the transfer charger, 27 are registration rollers that convey the transfer paper, 28 are paper feed rollers that feed the transfer paper from the paper feed table 29, and 3o are transfer rollers sent out by the paper feed roller 28. It is a separation row that separates paper into individual sheets.

Reference numerals 31 and 32 refer to a slide portion for pulling out the belt unit consisting of the belt photoreceptor 6 and various elements such as rollers that stretch it out of the housing of the copying machine CM; 33 is attached to the back surface of the belt photoreceptor 6; This is a belt back cleaner that removes toner.

FIG. 3 shows the approximate position of each element in the belt unit. Note that details of each element will be described later.

35 is a reference sensor for setting the reference position of the meandering correction roller 12, and 36 is a step motor for controlling the deflection position of the meandering correction roller 12.

37 is a deflection plate for deflecting the meandering correction roller 12 in the directions of arrows C and D, 38 is a roller support plate that supports the meandering correction roller 12, and 39 is a spring for making the meandering correction roller 12 function as a tension roller. .

A release lever 40 is connected to the roller support plate 38 via a link 40a. Therefore, when the release lever 40 is rotated in the direction of the arrow, the roller support plate 38
moves in the direction of the arrow, and the tension applied to the belt photoreceptor 6 by the @ line correction roller 12 is released.

Thereby, the belt photoreceptor 6 can be removed from the belt unit.

FIG. 4, FIG. 5, and FIG. 6 show the configuration of the vicinity of the sensor section 24.

As shown in the figure, the sensor section 24 is a reflective photosensor 3.
1 to S4 are arranged, a support plate 24b that supports this substrate 24a, and a sensor guide 24c that guides this support plate 24b.

Further, a terminal for output signals of the photosensors 51 to S4 is attached to one end of the substrate 24a, and this terminal is connected to the side plate SB.
It is inserted into the connector CN attached to 2.

Furthermore, a presser spring 24d is attached to the sensor guide 24c, thereby fixing the support plate 24b within the sensor guide 24c.

A black conductive band BE is attached to both sides of the belt photoreceptor 6 for grounding, and a reflective mark word (for generating a process start timing) is provided at an appropriate location on this conductive band BH. Further, since a metal roller is usually used as the driven roller 14, its surface reflects light well.

Therefore, the belt photoreceptor 6 rotates and the reflective mark 6 is moved to the photosensor S3. When detected in S4, this detection signal is applied to a main body control section (not shown) to start the copying process.

Furthermore, when the belt photoreceptor 6 is running normally without meandering, both the photosensors Sl and 32 detect the driven roller 14, and therefore an ON signal is output to the control section, which will be described later. When the belt photoreceptor 6 meanders in any direction, one of the photosensors SL and S2 detects the black conductive band BE and its output is reversed, thereby letting the control section know that the belt photoreceptor 6 meanders and its direction. be able to.

In Fig. 4, SBI is the front plate of the belt unit, S
B2 is the rear side plate of the belt unit, and MS is the front side plate of the copying machine main body.

FIG. 7 shows the drive section of the meandering correction roller 12.

In the figure, 41 and 42 are stepped screws, 43.44 are stepped studs, 37 is a deflection plate, 38.45 is a roller support plate, and 38a and 45a are steps fixed to the roller support plate 38.45. 46 is a shaft fixed to the roller support plate 40, 47 is a bearing for the shaft 46, 49 and 5o
51 is a boss fixed to the roller support plate 38 and the deflection plate 37 to receive the shaft 48 of the meandering correction roller 12; 51 is a front plate S;
This is a shaft that connects the DI and the rear side plate SB2.

Further, the pin 52 disposed on the deflection plate 37 forms part of a power transmission system that transmits the power of the step motor 36 to the deflection plate 37, as will be described later.

As shown in FIG. 9, the shaft 48 is supported by self-aligning bearings 55, 56.
A slide member 57 is inserted into the bearing 55, and the shaft 48 is connected to the boss 49.50 through the bearing 55.
It is slidably supported in the longitudinal direction within.

Further, a spring 39 is stretched between the stepped studs 38a and 43, and a spring 58 is stretched between the stepped studs 44 and 45a. Therefore, the action of the spring 39 causes the roller support plate to
8 slides toward the stepped stud 43,
Under the action of the spring 58, the roller support plate 45 and the deflection plate 37 slide together toward the stepped stud 44, and as a result, tension is applied to the photoreceptor 6 to the bell 1 by the meander correction roller 12.

Note that FIG. 8 shows a state in which the release lever 4o is operated to the release position. Also, 59 is the release lever 4
0 front plate side link 40a and rear side plate side link 40b
It is the axis that connects the

FIG. 9 shows the meandering correction roller 12 from the step motor 36.
It shows the power transmission system to.

A step motor 3 is attached to the pedestal BS arranged on the rear side plate SB2.
6 is fixed, and a microphone gear 60 is attached to the shaft of the step motor 36. A lead screw 62 is coaxially connected to the microphone gear 61 that is paired with the microphone gear 60, and a slider 6 with fingers is connected to the lead screw 62.
3 are screwed together.

The slider 63 supports the pin 52 attached to the deflection plate 37 with its fingers, and one side of the slider 63 is in contact with the surface of the deflection plate 37.

Note that the lead screw 62 is supported between a support portion B and 882 formed by cutting and raising a part of the rear side plate SB2.

Now, assuming that the lead screw 62 is formed with a right-hand thread, when the step motor 36 operates in the Cw (clockwise) direction, the slider 63 moves downward in the figure, and as a result, the meandering correction roller 12 Deflect in the direction of arrow C in Figure 3. As a result, the belt photoreceptor 6 moves obliquely in the direction of the front side plate SB1.

Further, when the step motor 36 operates in the CCV (counterclockwise) direction, the slider 63 moves upward in FIG. 9, thereby deflecting the meandering correction roller 12 in the direction of the arrow in FIG. 3. As a result, the belt photoreceptor 6 is attached to the rear plate SB.
Diagonal in two directions.

By the way, when the deflecting plate 37 is rotated, the shaft 48 is moved to the post 49.
attempts to rotate using the self-aligning bearing 55 as a fulcrum. However, since the movement direction of the boss 50 that receives the shaft 48 is restricted by the front and rear side plates, the shaft 48 cannot move circularly. As a result, when the shaft 48 moves in the directions of arrows C and D as shown in FIG. are doing.

In this figure, arrows C and D indicate the same direction as in FIG. 3. Further, the distance L1 indicates the axial length of the meandering correction roller 12 when it is not deflected, and the distance L2 indicates the axial length of the meandering correction roller 12 when it is deflected to the limit point, respectively.
The distance indicates the distance to the limit point at which the shaft 48 is deflected in the directions of arrows C and D. Naturally, the distance L2 is greater than Ll, and the shaft 48 slides within the self-aligning bearing 55 by the difference.

Further, as shown in FIG. 11, when the release lever 40 is operated to the release position, the link 40a and the link 4
The roller support plates 38 and 45 are pulled in the direction of arrow B by the action of 0b, which in turn pulls the deflection plate 37 in the direction of arrow B'. Therefore, as the meandering correction roller 12 separates from the belt photoreceptor 6, the pin 52 moves away from the slider 6.
3, the meandering correction roller 12 can be easily moved and does not get in the way when the belt photoreceptor 6 is replaced. FIG. 12 illustrates a control system for controlling the meandering correction roller 12.

In the figure, 70 is a mode setting device (for example, dip switch, rotary switch, etc.) for setting an operation mode to be described later, and this mode setting value 70. The output data of the reference sensor 25 and photosensors Sl and S2 is sent to the control unit 71.
added to.

The control unit 71 executes a predetermined meandering correction process (described later) based on the applied data, outputs a control signal to the driver 72 of the step motor 36, and controls the deflection position of the meandering correction roller 12.

As described above, one of the causes of meandering of the belt photoreceptor 6 is the difference in the circumferential length of the belt photoreceptor 6. Since this can be measured in advance, the degree of meandering caused by this circumferential length difference can be known.

Therefore, if the meandering correction roller 12 is deflected in advance so as to cancel the meandering caused by this circumferential length difference, the amount of meandering of the belt photoreceptor 6 will be reduced, and the meandering correction roller 12 will be deflected in advance.
It is possible to suppress the change in the deflection position to a small value.

Now, the circumferential length difference E is determined as shown in the following equation.

E=SL2-SLI where SLI is the circumferential length of the front plate side edge of the belt photoreceptor 6, and SL2 is the circumferential length of the rear plate side edge.

Then, preset deflection positions (indicated by the drive direction and pulse number of the step motor) with respect to the station difference E are determined in stages as shown in FIG. 13, and mode numbers are assigned to each. That is, in a range where the station difference E is smaller than -0.2 (nwn), the step motor 36 is operated for 400 pulses in the CCv direction at positions P1 (mode 1), -0, 2 to -0.
, 1 (nu), position P2 (mode 2) where 200 pulses were activated in the CCl11 direction, -0,1 to +0.
1 (+nm) range, standard position P3 (mode 3),
In the range of +0.1 to +0.2 (mm) (20 mm in the J direction)
0 pulse activated position P4 (mode 4), +6.2 (
In a range larger than 400 pulses in the Cv force direction, the motors are driven to the position Ps (mode 5), which is activated by 400 pulses in the Cv force direction.

The above-mentioned position P3 is a position where the meandering correction roller 12 is in a non-deflected state.

The preset deflection position described above was determined for the following reason.

That is, when the direct-to-direction difference E is positive, as is clear from the above equation, the circumferential length of the end on the rear side plate is long, so the bell 1 and the photoreceptor 6 meander toward the rear side plate. Therefore, in order to suppress this, the meandering correction roller 12 is
The belt photoreceptor 6 may be deflected in the direction of arrow C in the figure to move the belt photoreceptor 6 toward the front plate, and for this purpose the step motor 36 is operated in the direction 6w. If the station difference E is negative, the situation is the opposite, so the actuator is operated in the CCv direction.

Also, since the absolute value of the circumference difference E and the degree of meandering are proportional,
When the circumferential length difference E is large, the amount of deflection from the standard position P3 is increased.

FIG. 14 shows an example of meandering correction control executed by the control section 71.

First, when the copying machine CM is powered on, the control unit 71
The mode setting device 70 inputs remote data (process 101), and deflects the meandering correction roller 12 to a position corresponding to the input data based on the relationship shown in FIG.
Process 102). That is, the motor is moved from the final step motor drive position (direction and number of pulses) when it was previously used to the step motor drive position (any of positions P1 to P5 in Figure 13) corresponding to the set mode. The operating direction and pulse number are determined and output to the driver 72.

After the meandering correction roller 12 is deflected to the initial deflection position in this way, the photo sensor S1
is detected (the result of judgment 103 is VB2), the step motor 36 is driven by a predetermined amount in the Cv force direction (process 104)
, when the photosensor S2 detects the belt photoreceptor 6 (
If the result of judgment 105 is YES), the step motor 36 is driven by a predetermined amount in the cctt direction (process 106), and these processes are repeated until the power is turned off (loop of judgment 107).

The number of drive pulses in processes 102 and 104 is the number for driving the step motor 36 to the limit of the drive range in each mode (the tip of the arrow in FIG. 13). For example, if the operation is started from position P1 of 400 pulses in the ccv direction in mode 1, and the belt photoreceptor 6 is detected by the photosensor S1, the step motor is driven with 200 pulses in the CW force direction, and in this state, the belt photoreceptor 6 is 6 is detected by the photosensor s2, the CC1N direction Δ-400 pulse step motor 36 is driven. The same applies to other modes in other cases.

By the way, in the embodiment described above, in order to execute the process 102, it is necessary to store the previous state of the drive position of the step motor, and a storage means for this purpose is required.

Next, another embodiment that eliminates such inconvenience will be described.

In this embodiment, as shown in FIG. 15, the reference position is a position driven by 800 pars in the 6w direction from the standard position P3 in FIG. 13, and as shown in FIG. 16.

A reference sensor 25 is provided corresponding to this position.

As shown in FIG. 17, the control unit 71 executes a process 101 for inputting mode data, and then moves the step motor 3 in the C111 direction until the reference sensor 25 is turned on.
6 (process 1111 judgment 112).

Then, processing 102 is executed, and if mode 1 is set, for example, the movement is performed by 1200 pulses in the CC1N direction.

In this way, the step motor 36 is driven in the 6w direction until the reference sensor 25 is once turned on, and then driven in the CCv direction to match the mode, so the immediately previous driving state of the step motor 36 is memorized. There is no need to keep it. Furthermore, since the actuator is moved to a reference position once and then driven to a predetermined position, the positioning accuracy is also good.

Note that in FIG. 17, the contents after process 102 are the same as those in FIG. 14, so the explanation will be omitted.

In the above embodiments, a step motor is used to deflect the deflection plate, but other motors may be used. Furthermore, the mode setting ranges shown in FIGS. 13 and 14 are determined by the characteristics of the device, and are not limited thereto.

Moreover, it is of course applicable not only to the belt unit of a copying machine but also to other similar endless belt drive devices.

[Effect] As explained above, according to the present invention, since the initial deflection amount of the meandering correction roller is set according to the circumferential length difference of the endless belt, meandering due to the circumferential length difference can be suppressed, and as a result, the endless belt The advantage is that the meandering width can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional example of an endless belt drive device;
FIG. 2 is a schematic diagram showing a copying machine according to an embodiment of the present invention, FIG. 3 is a partial diagram showing a belt unit in detail, and FIG.
Figures 5 and 6 are a partial cross-sectional view, a perspective view, and a partial perspective view showing the installation outline of the sensor unit, respectively, and Figures 7 and 8 are the drive unit of the palm-side meandering correction roller. A perspective view and a partial sectional view, FIG. 9 is a perspective view illustrating the power transmission system, FIG. 10 is a schematic diagram showing the deflection mode of the meandering correction roller, and FIG. 11 is a perspective view for explaining the action of the release lever. Fig. 12 is a block diagram illustrating the control system, Fig. 13 is a graph illustrating the relationship between circumferential length difference, mode, and initial deflection amount, Fig. 14 is a flowchart illustrating an example of control, and Fig. 15 is FIG. 17 is a flowchart showing another example of control. 6... Belt photoreceptor, 12... Meandering correction roller, 3
5... Reference sensor, 36... Step motor, 37
... Deflection plate, 38, 45 ... Roller support plate, 46.
...Shaft, 47...Bearing, 49.50...Boss, 52
... Pin, 55.56 ... Self-aligning bearing, 60.
61... Microphone gear, 62... Lead screw, 63
...Slider, 70...Mode setter, 71...
Control unit, 72... Driver. Fig. 7 Fig. 2 Fig. 71 Fig. 76 Fig. 73 Fig. 15 Circumference 1 gap (E)

Claims (1)

[Claims] In an endless belt drive device, one of the plurality of rollers that supports and drives the endless belt in a stretched manner rotatably supports one end of the shaft of the meandering correction roller, which acts as a meandering correction roller that corrects the meandering of the endless belt. It is equipped with a bearing, a deflecting means for deflecting the other end of the shaft of the meandering correction roller, and a control means for controlling the direction and amount of deflection of this deflecting means, and the initial deflection position of the meandering correction roller is adjusted according to the station difference of the endless belt. An endless belt drive device characterized by the following settings.