JPS59172313A - Breadth position control device for endless belt - Google Patents

Abstract

PURPOSE:To improve assembling performance by providing a belt breadth position adjustment roller, swayed vertically with one end as a fulcrum, on the captioned device which controls a position in the breadth direction of a wide belt according to the output from an oblique motion detector, and realizing control of said motion by means of a single oblique motion detector. CONSTITUTION:During traveling of an endless belt 11 with swivel of a driving roller 12, in case said belt 11 is displaced in the direction of breadth and sways a lever 26 of an oblique motion detector 24 round a support shaft 28, light from a luminous part is irradiated at a light detection part 27, and output voltage of said detector 24 exceeds the standard voltage, while the output from a comparison circuit COM turns H. Then, Q output from D flip-flop FF grows into H level due to rise of sampling clock CP sent out from a clock generating circuit CLK. This puts a transistor Tr in ON state, and a solenoid 19 is set conductive, and an arm 18 is pulled. As a result, this side 15b of a breadth position adjustment roller 15 is pushed up, and the belt 11 is moved to the interior side for correction of position.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a width position control device for an endless belt, and particularly to an oP
The present invention relates to a width position control device for an endless belt suitable for preventing skewing of wide belts such as C belts and dielectric belts.

[Prior Art] In the case of a belt of normal width, skew can be easily prevented by providing flanges at both ends of each roller on which the belt is stretched. However, 0PC (Organic Ph
When it comes to wide belts such as ot;o' Conductor (photoconductor for PPC) or dielectric bells, the above flange cannot prevent the belt from being damaged; if the flange is low, it can be overcome, and if it is high, the belt end is pushed by the flange. be crushed. In order to avoid such problems, conventionally, as shown in FIG. The width direction position was controlled.

However, according to the above-mentioned conventional method, two skew detectors 2 must be disposed at the ends of the belt, which makes it difficult to apply to devices such as facsimiles that strongly require compactness. , it is also disadvantageous in terms of cost. In order to realize more stable belt width position control, it is necessary to keep the control dead band width (b+c) almost constant. For this reason, in the conventional method described above, the installation width of the skew detector 2-2 is adjusted to the belt width. There is a problem that adjustment must be made according to a, which makes the work complicated.

[Objective] The present invention reduces the number of skew detectors to one.
77. It is an object of the present invention to provide a width position control device for an endless belt that is compact, low cost, and can provide stable belt width position control.

[composition] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a configuration diagram of an endless belt width position control device according to an embodiment of the present invention, in which 11 is a roller 12 to 1
It is an endless belt suspended from 5.

Twelve of the rollers are rollers for driving an endless belt, and a pulley 16 is provided at the end of the shaft, and the drive belt 1
It is connected to a motor (not shown) via 7. Reference numeral 15 denotes a width position adjustment roller for the endless belt 11, and a bearing (not shown) provided at one end 15a of the roller shaft allows the other end 15b of the roller shaft to move up and down by several millimeters using the bearing as a fulcrum. It is swingably held on a side plate (not shown). The shaft of the other end 15b of the width position adjusting roller 15 is fitted into a four part 18b provided at one end of the arm 18 having a pivot 18a in the center. Needless to say, a bearing is provided at the end of the shaft. That arm 18
A solenoid 19 and a spring 20 are connected to the other end, and when the solenoid 19 is OFF, the spring 2
The other end is locked to the stopper 21 by the spring force of o. Further, a lever 23 is pressed against the axial end of the width position adjusting roller 15 by a spring 22, and tension is applied to the roller 11 by this pressing force. A belt skew detector 24 is provided at one end in the width direction of the endless belt 11 driven by the driving roller 12.

FIG. 3 shows the configuration of the skew detector 24. In this embodiment, the skew detector 24 is a transmission type sensor consisting of a lever 26 having a shutter mask 25 and a light detection section 27. It is configured.

The shutter mask 25 consists of an opaque part 25a and a transparent part 25b. The lever 26 is rotatably supported by a support shaft 28, and is locked to a stopper 30 by the force of a spring 29 when the lever 11 is not in contact with the endless bell 1.

Figure 4 shows the output of the skew detector 24 turning the solenoid 19 to 0N.
This is a control circuit diagram that adjusts the widthwise position of the endless belt 11 by -OFF control, where R1 is a current limiting resistor, R2 is a photocurrent detection resistor, and R3 and R4 are voltage dividing resistors for generating reference voltage. , COM is a comparison circuit, CLK is a clock generation circuit for sampling the sensor output, FF is a D flip-flop, and T and r are solenoid driving transistors.

With the above +q configuration, the endless belt 11 is connected to the driving row 12.
When driven by, it is displaced in the width direction. The lever 2G of the skew detector 24 swings in accordance with the displacement of the endless belt 11.

It is now assumed that the endless belt 11 is not in contact with the lever 26. Then, the opaque part 2 of the shutter mask 25
5a covers the photodetector section 27, the output v1 of the skew detector 24 becomes lower than the reference voltage Vs, as shown by tie 11char 1- in FIG.

Therefore, the output of the comparison circuit CoM is "L", the Q output of the flip-flop FF is at the rLJ level, the transistor Tr is OFF, the solenoid 19 is also OFF, and the arm 18 in FIG. The concave portion 1.8b side is lowered, and the width position adjustment roller 15 is rotated with one end 15a of the shaft as a fulcrum and the other end 15b as described above.
The side is pushed down in the direction of the arrow. As a result, the endless belt 11 shown in FIG. 2 moves toward the front and comes into contact with the lever 26.

Rotate the lever 26 as shown in FIG. As a result, the light detection section 27 is located in the transparent section 25b, the output voltage Vi of the skew detector 24 exceeds the reference voltage VS, and the comparison circuit C
The 0M output becomes "+]".

When the comparison circuit C0M output becomes r)-IJ, the Q output of the [) flip-flop FF becomes the clock generation circuit CL.
At the rising edge of the sampling clock CP output from K, the level becomes rHJ. Due to this 1t, the transistor T
r is turned on, so the solenoid 19 is turned on. Then,
The arm 18 in FIG. 2 is pulled by the solenoid 19 into the recess 1.
8b side is up, and the front side 15b of the width position adjustment roller I5
is pushed up in the direction of the arrow. As a result, endless belt 1
1 begins to move towards the back. When the endless belt 11 moves to the back side as seen in FIG. 2 and to the right side as seen in FIG. The voltage will drop below the reference voltage Vs, but at this time as well, the solenoid 19 will
It does not operate immediately, but turns OFF only after the output of the comparator circuit 00M becomes "L", waits for the input of the sampling clock CP, and the D flip-flop FF is inverted.

In this way, by detecting the movement of the endless bell 1-11 with one skew detector 24 and turning on/off the solenoid 19, the shaft 15b in front of the width position adjusting roller 15 shown in FIG. By vertically moving the endless belt 11 and periodically moving the endless belt 11 in the width direction, the amount of movement of the endless belt 1-11 can be kept within a predetermined range and skew movement can be prevented. In this case, the dead band width of the control can be easily adjusted by the generation cycle of the sampling clock CP, and the ON-OFF interval can be set to the optimum state regardless of the width of the endless belt j1.

In addition, the bell 1-width position control is performed by the width position adjusting roller 1.
The installation of the width position adjustment roller 15 is performed by moving one end 15b of the width position adjustment roller 15 up and down to constantly swing the endless belt 11 from side to side in the width direction, and there is no need to keep the width position adjustment roller 15 horizontal. Also, the adjustment work becomes extremely easy.

Note that the skew detector 24 is not limited to a transmission type optical sensor, and any known sensor such as a reflective type optical sensor or a limit switch can be used.

Furthermore, in the above embodiment, the clock generation circuits C1, , K are provided, and the sampling clock CP obtained from them is input to the D flip-flop, but instead of this, a periodic signal generated from the device may be used. You can also do this. For example, when applied to a copying machine or printer, the above implementation may be performed by sampling the comparator circuit 00M output using a signal generated during a processing sequence cycle that is repeatedly executed, such as a copy start signal. Effects similar to those in the example can be obtained.

[Effects] As described above, according to the present invention, only one belt skew detector is required, which is advantageous in terms of space. It is possible to extremely simplify η1 and reliably prevent the width bell 1- from moving diagonally.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the installation state of a conventional peeling detector, Fig. 2 is a configuration diagram of a pel 1 to width position control device according to an embodiment of the present invention, and Fig. 3 is a skew detection of Fig. 2. FIG. 4 is a diagram showing the control circuit 1 shown in FIG. 2, and FIG. 5 is a time chart of signals of each part shown in FIG. ]1...Endless belt, 12-15...Roller, 16...Pulley, 17...Drive belt, 1
8... Arm, 19... Solenoid, 20, 22
．． 29...Spring, 21.30...Stopper, 23.26...Lever, 2.1...Pel 1~
Skew detector, 25... Shutter mask, 27 ・
・Light detection unit, 28...Spindle. Figure 7 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a width position control device for an endless belt 1-, which controls the width direction position of a wide belt wound around a plurality of rollers according to the output from a skew detector, one end is used as a fulcrum and the other is set as a fulcrum. A belt width position adjustment roller whose end can move up and down, a solenoid that moves this roller up and down, and a skew detector provided at the end of the belt. A width position control device for an endless belt, comprising a control circuit that samples the detection signal from the skew detector using periodically generated pulses and turns on and off the solenoid according to the result.