JP3417306B2 - Photoreceptor belt drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoreceptor belt driving apparatus capable of quickly controlling the meandering of a photoreceptor belt and preventing a speed fluctuation occurring at the time of the control to obtain a high-quality image. About.

[0002]

2. Description of the Related Art A photoreceptor belt used in an electrophotographic apparatus often uses a material having a small elongation, such as plastic or thin metal, as a base material. This type of belt has a problem that bias is easily generated due to slight unbalance of tension and dimensional accuracy at both ends of the belt.

[0003] As an apparatus for solving these problems, there has been proposed a construction in which a deviation is forcibly stopped by a guide provided on a photoreceptor belt as disclosed in Japanese Patent Application Laid-Open No. Sho 56-127501 or Japanese Patent Application Laid-Open No. 47-13955. When the photoreceptor belt meanders as described above, it hits the detection ring, and the roller is moved by a link connected to the detection ring to correct the meandering. As described in Japanese Patent Application Laid-Open No. 4-121337, the belt meanders by deviation. There is disclosed a configuration in which a detection member is rotated, a mechanism for converting the rotational motion to a linear motion, and swinging the roller itself to correct the deviation is provided.

[0004]

However, in the configuration disclosed in Japanese Patent Application Laid-Open No. 56-127501, excessive stress is concentrated on the base material of the guide portion, and the belt is easily damaged, so that it is necessary to increase the strength of the base material. On the other hand, there has been a problem that deviation tends to occur. Also, Japanese Patent Application Laid-Open No.
In the configuration of Japanese Patent Publication No. 37, since the deviation is corrected by a wire, the time lag from the detection of the deviation of the belt to the correction is large, and the deviation is further increased before the correction is started. was there.

Further, also in the example of Japanese Patent Application Laid-Open No. 47-13955, the belt which is offset to the detection ring detects the offset by moving against the detection ring, so that a large force is applied to the belt and the belt is easily damaged. Further, since the deviation is forcibly corrected, there is a problem that a speed fluctuation in the rotation direction of the belt occurs at the time of the correction.

A first object of the present invention is to provide a photoreceptor belt driving device capable of shortening the time lag from detection to correction without applying excessive stress to the belt.

It is a second object of the present invention to provide a photoreceptor belt driving device which can reliably perform belt positioning at the same time without causing a speed fluctuation of the belt at the time of correcting belt misalignment.

[0008]

To achieve the above Symbol purpose SUMMARY OF THE INVENTION The photoreceptor belt driving device of the present invention, a photosensitive belt
A driving roller for driving the photoreceptor belt;
A driven roller for bridging an optical belt, and the photosensitive belt
Tension roller for applying tension to the drive roller, and the drive roller
And a frame supporting the driven roller, and the photoconductor
Photoreceptor composed of a meandering correction device that corrects belt deviation
In the belt driving device, the meandering correction device may be configured as described above.
A projection provided on the inner peripheral surface side of the photoconductor belt;
The drive so that the protrusion comes into contact when the
The shaft end of one of the roller and the driven roller
In addition, it can rotate independently of this first roller and has a rotation angle
A ring provided with a restricted degree and one end
Rotatably supported on one end of the tensioning side, and the other end is
Roller to freely rotate the ring,
This tension roller is transmitted to the tension roller.
The side supporting the other end of the
So that the tension of the photoreceptor belt is reduced.
A link to urchin moving, absorption rotation of said ring
Flexibility to be transferred to the tension roller after being absorbed or attenuated
A link made of a material with different properties, a link divided into two,
Consists of either a link via a spring or a spring
Transmission means.

When the bias of the photosensitive belt advances, a protrusion
The contact force between the part and the ring increases, and the ring rotates. Re
Rotation is transmitted to the tension roller via the link.
And move the tension roller to offset the photoreceptor belt.
Correction. At this time, make sure that the link is a flexible member.
Link, split link, spring
Absorbs ring rotation as link or spring
Or, by attenuating and transmitting to the tension roller
Photoreceptor belt by reducing the offset correction sensitivity
You can run. Furthermore, in the present invention,
To correct the deviation of the body belt , a tension roller
Is moved so that the tension of the photoreceptor belt is reduced.
The smaller the tension of the photoreceptor belt, the greater the speed fluctuation
Made, but by regulating the rotation angle of the ring, Teng
Since the roller does not move beyond a certain amount , the photoconductor
A stable speed of the belt can be maintained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 1 shows an embodiment of a photoreceptor belt driving device 1 in which an excessive stress is not applied to a belt and a time lag from detection to correction can be shortened. The photoreceptor belt 2 is wound around three rollers: a driving roller 3, a driven roller 4, and a tension roller 6. Drive roller 3,
The driven roller 4 is configured such that rotating shafts 32 and 41 are supported by a frame 100 (see FIG. 2) and rotate. The tension roller 6 has a rotating shaft 61 provided on the frame 100 and a rotating shaft 7.
The photoreceptor belt 2 is supported by an arm 7 that rotates about 1 and receives tension from a spring 8 to apply tension to the photoreceptor belt 2. The surface of the drive roller 3 is coated with rubber having a high coefficient of friction, and a rotational force is applied from a drive source (not shown) so that the rotational force is efficiently transmitted to the photosensitive belt 2.

FIG. 2 is a sectional view of the drive roller 3 and the tension roller 6. A drive roller rotation shaft 32 is provided with a taper ring 31 that rotates independently of the drive roller 3. The taper ring 31 and the rotation shaft of the tension roller 6 are rotated.
61 are linked by link 9.

The photoreceptor belt drive 1 is mounted on an electrophotographic apparatus (not shown), and the photoreceptor belt 2 is moved in the direction of arrow A (FIG. 1).
), The photoreceptor belt 2 is shifted in one direction due to a slight parallelism error between the rollers extending over the belt. As shown in FIG. 3, when the photoreceptor belt 2 is shifted in the direction of arrow B, a guide made of silicon rubber adhered to the entire periphery of the inner peripheral end of the photoreceptor belt 2 or the entire periphery except a part thereof.
21 comes into contact with the tapered portion of the tapered ring 31. Here, the taper ring 31 is provided with a taper whose angle with the photosensitive belt 2 is θ1.

When the deviation advances, the contact pressure between the guide 21 and the taper ring 31 increases, and a rotational force acts on the taper ring 31 to rotate in the direction of arrow A '. The rotation of the taper ring 31 is converted into a linear motion via the link 9 and moves the tension roller 6 in the direction of arrow C against the acting force of the spring 8. When the tension roller 6 is displaced from the broken line position to the solid line position as shown in FIG. 3, the photosensitive belt 2 is conveyed in a direction perpendicular to the axis of the tension roller 6, so that the photosensitive belt 2 is shifted in the direction of arrow D. . Therefore, the photoreceptor belt 2 moves in the direction opposite to the one-sided direction, and the one-sided shift is corrected.

With this configuration, the time lag from the detection of the deviation to the correction can be shortened, and the deviation during the period can be reduced.

When the deviation is corrected, the guide 21 and the taper ring 31 move away from each other, so that the contact force between the guide 21 and the taper ring 31 is weakened, and the tension roller 6 returns to the original position by the action of the spring 8 to complete the correction. Since a slight parallelism error between the rollers remains in the photoconductor belt driving device 1, the photoconductor belt 2 starts to shift again in the direction of arrow C almost immediately after the correction is completed.

Accordingly, the photoreceptor belt 2 shifts and moves stably at a certain position while repeating the correction operation.

FIG. 4 further shows that the deviation of the conveyance speed of the photosensitive belt 2 due to the generation of an excessive driving force on the taper ring 31 during the deviation is prevented, and the deviation is reliably detected. Guide 21 is tapered.
An embodiment for stably running the photosensitive belt 2 by preventing the photosensitive belt 2 from being damaged by contact with the photosensitive belt 2 due to excessive stress being applied thereto.

The maximum outer diameter d2 of the taper ring 31 is made smaller than the outer diameter d1 of the drive roller 3 so that the back surface of the photoreceptor belt 2 and the taper ring 31 do not come into contact with each other.
The guide 21 and the tapered ring 31 are in contact with each other only when they are offset, so that a rotational force is applied to the tapered ring 31. Preferably, the maximum outer diameter d2 of the tapered ring 31 is smaller than the outer diameter d1 of the driving roller 3 and larger than a value obtained by subtracting twice the height h of the guide 21 from the outer diameter of the driving roller 3, that is, d1-2h. By setting d2 <d1, the guide 21 is tapered only when the photoreceptor belt 2 is offset.
If the photoconductor belt 2 is configured such that excessive stress does not act on the photoconductor belt 2 even if the photoconductor belt 31 comes into contact with the photoconductor 31, the deviation can be reliably detected and corrected.

Further, as shown in FIG. 5, taper rings 31, 31 ', links 9, 9', guides 2
When the distance between the tapered rings 31 and 31 'is reduced with respect to the distance between the guides 21 and 21' and the distance between the guides 21 and 21 ', the photosensitive belt 2 is deviated irrespective of the direction of the deviation of the photoreceptor belt 2. Only in this case, the deviation can be detected and corrected reliably. The symbol “′” indicates the same member provided on the opposite side.

If the rotational force acting on the tapering 31 is excessively transmitted to the link 9, the tension roller 6 moves rapidly against the spring 8, so that the tension of the photosensitive belt 2 decreases from a predetermined value.

As shown in FIG. 11, the speed fluctuation of the photosensitive belt 2 increases as the tension of the photosensitive belt 2 decreases. That is, when the tension roller 6 moves due to the deviation correction, the running speed of the photosensitive belt 2 becomes unstable, and unevenness occurs in the image during development and transfer, or in a color electrophotographic apparatus in which a plurality of color toners are superimposed. Causes misregistration of each color and disturbs the image.

Therefore, in order to run the photoreceptor belt 2 stably, it is necessary to efficiently correct the deviation, that is, the rotational force of the taper ring 31 for moving the tension roller is required, and at the same time, the rotational force is reduced. It is very important not to be transmitted to the tension roller 6 excessively.

For this reason, it is necessary to reduce the amount of movement of the link 9, that is, the amount of movement of the tension roller with respect to the rotation angle of the taper ring 31, and to reduce the sensitivity for correcting the deviation.

FIG. 6 shows a photoreceptor belt driving device 1 which can reliably perform belt positioning without causing speed fluctuation of the belt when correcting belt deviation. Drive roller 3
The position of the link 9 support point 10 on the end of the tapered ring 31 provided outside (not actually shown on the surface but shown for convenience) is larger than the center line connecting the rotation center of the driving roller 3 and the rotation center of the tension roller 6. The link 9 with respect to the rotation angle of the taper ring 31 is closer to the downstream side in the rotation direction of the driving roller 3.
, That is, the moving speed becomes large, and becomes maximum when it is located on a line passing through the rotation center of the driving roller 3 and orthogonal to the center line.

Therefore, when the support point 10 is within the above range, the rotational force of the taper ring 31 is efficiently transmitted to the link 9 to perform the offset correction, and the speed of the photosensitive belt 2 at the time of the offset correction. Fluctuations can be prevented.

FIG. 15 shows that when the link 9 starts moving, the angle θ2 between the center line connecting the rotation center of the driving roller 3 and the rotation center of the tension roller 6, the support point 10 and the rotation center of the driving roller is shifted toward the belt, and This is the result of experimentally determining the effect on speed fluctuation. The belt deviation is indicated by "O" when the deviation is corrected, "X" when the deviation is not corrected, "O" within 0.01%, "Δ" within 0.01% to 0.02%, and "0.
X was defined as 02% or more. As a result, when the angle is 0 <θ2 <90 °, it is favorable for the deviation of the belt.
At θ2 <70 °, the belt shift is particularly favorable against the speed fluctuation, and the link 9 does not move more efficiently and excessively. In other words, the deviation is corrected by gradually displacing the link 9 with the rotation of the taper ring 31, and at the same time, the photosensitive belt 2 runs stably without a sudden change in tension.

Further, in order to reduce the deviation correction sensitivity, the link 9 is made of a flexible material such as plastic, and the displacement of the link 9 due to the rotation of the tapered ring 31 is absorbed or attenuated by the elasticity of the link. When transmitted to the tension roller 6 in this way, more effect can be obtained.

As shown in FIG. 7, the link 90 is divided into two links A91 and B92, one of which is a tapering 3
1, the other is supported on the rotating shaft 61 of the tension roller 6, and the two are rotatably connected at a fulcrum 94 to form a link 90.
Is reduced or attenuated at the fulcrum 94, and a similar effect is obtained.

As shown in FIGS. 8 and 9, the link A91,
It is more effective to reduce the sensitivity by connecting or linking the link B92 with the spring 94 or the damper 95 to reduce or attenuate the displacement of the link 90 by the spring 94 or the damper 95.

Further, as means for stabilizing the speed of the photosensitive belt 2 at the time of deviation correction, as shown in FIG. 10, a groove is formed in the circumferential direction of the end face of the tapered ring 31 so as not to rotate the tapered ring 31 beyond a predetermined angle. When the projections 101 are provided so as to interfere with the grooves 33 and regulate the rotation of the taper ring 31, the link 90 and the tension roller 6 do not move more than a certain amount, so that the photosensitive belt 2 is surely driven at a stable speed. Can be maintained, and the deviation can be corrected.

Here, as shown in FIG. 12, the projections 101 are arranged from the position facing the tapered ring 31 of the frame 100 holding each roller toward the groove 33 provided in the tapered ring 31. At this time, the rotation angle of the taper ring 31 is the groove 33,
It can be set arbitrarily according to the size of the projection 101.

As shown in FIG. 13, a protrusion 36 is provided at the side end of the tapered ring 31 toward the frame 100, and the protrusion 36 is provided at a position facing the tapered ring 31 of one of the frames 100.
The same effect can be obtained by providing the groove 102 in which the groove 102 enters.

Further, as shown in FIG. 14, a protrusion 38 is provided at the end of the taper ring 31 on the drive roller 3 side, and a groove 37 which interferes with the protrusion 38 is provided at the end of the drive roller 3 facing the protrusion 38. Similar effects can be obtained even if the rotation of the ring 31 is restricted.

When the taper ring 31 is rotated by friction with the guide 21 on the inner peripheral surface of the photosensitive belt, the guide
Also, the taper portion angle of the taper ring 31 that comes into contact with 21, and the friction coefficient of the taper ring 31 and the guide 21 also avoid the unstable phenomenon caused by the excessive driving force generated in the taper ring 31 when the taper is biased, and surely This is an important factor for detecting and correcting the deviation. Also, guide 21 is tapered ring 31
It is also important to prevent the photosensitive belt 2 from being damaged by contact with the photosensitive belt 2 due to excessive stress. In particular, stabilizing the frictional force between the two over a long period of time is essential for improving the reliability of the color electrophotographic apparatus.

If the taper angle of the contact portion of the end surface of the taper ring 31 with the guide 21 is too small, the taper ring 31 and the guide
Since the contact force of 21 becomes large, the taper ring 31 rotates even if it is slightly offset, causing the tension roller to move greatly, and the speed of the photosensitive belt 2 tends to become unstable. Conversely, if the taper is too large, the photoreceptor belt 2 shifts, and when contact starts, a large contact force acts almost at the same time, so that the speed of the photoreceptor belt 2 similarly becomes unstable.

The angle θ1 of the taper was determined experimentally to determine the offset and the stability of the speed, and to minimize the stress-induced damage of the photosensitive belt 2 due to the contact of the guide 21. It has been found that a range of 5 ° or more and 25 ° or less is particularly desirable.

In order to efficiently generate a driving force for rotating the taper ring 31, the taper ring 31 is formed of polyacetal resin, and the coefficient of friction with the guide 21 is set to 0.5.
It was found that setting the value to 0.9 or more was effective.

FIG. 16 shows the photoreceptor belt 2 of the tapered ring 31 having a surface coated with Teflon or molybdenum, a tapered ring formed of a resin containing Teflon or molybdenum, or a tapered ring formed of a polyacetal resin. Five
Repeated contact with guide 21 by driving for 0 hours,
This is the result of experimentally determining the speed fluctuation of the photosensitive belt 2 after that. Here, を indicates that the speed fluctuation is within 0.01%,
01 to 0.02% is indicated by Δ, and 0.02% or more is indicated by ×.

As a result, if the surface of the tapering 31 is coated with Teflon or molybdenum, or if the tapering 31 is formed of a resin containing Teflon or molybdenum, the speed becomes more stable for a long time.

On the other hand, FIG. 17 shows the case where the guide 21 is made of silicone rubber having various hardnesses, and
This is the result of experimentally determining the fluctuation in the speed of the photosensitive belt 2 after repeated contact with the guide 21 after running for 0 hours. Here, 速度, 0.01-0.0
2% is indicated by Δ, and 0.02% or more is indicated by ×.

As a result, the speed of the guide having a silicone rubber hardness Hs of 30 ° or more was stabilized for a long period of time.

When an additive such as silica is added to the silicone rubber, the material is tapered 31 and guide 21.
Since it acts as a kind of lubricant between the taper ring and the guide, wear of the guide can be reduced.
Can maintain a stable speed, and the deviation can be corrected.

[0044]

According to the present invention, rapidly increases the tension roller accuracy, also by moving slowly, at the same time can be corrected deviation of the photoreceptor belt, stable rotational force-ring for a long time since can be transmitted to the tension roller, it is possible to run the photoreceptor belt with high accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing a photoreceptor belt device of the present invention.

FIG. 2 is a diagram showing a driving roller unit of the present invention.

FIG. 3 is an operation explanatory diagram.

FIG. 4 is a view showing a driving roller unit of the present invention.

FIG. 5 is a view showing a driving roller unit of the present invention.

FIG. 6 is a view showing a photoreceptor belt device of the present invention.

FIG. 7 is a view showing a photoreceptor belt device of the present invention.

FIG. 8 is a view showing a photoreceptor belt device of the present invention.

FIG. 9 is a view showing a photoreceptor belt device of the present invention.

FIG. 10 is a diagram illustrating a photoreceptor belt device of the present invention.

FIG. 11 is a diagram illustrating speed fluctuations of the photosensitive belt.

FIG. 12 is a diagram illustrating a drive roller unit of the present invention.

FIG. 13 is a diagram illustrating a drive roller unit of the present invention.

FIG. 14 is a diagram illustrating a drive roller unit of the present invention.

FIG. 15 is an experimental result of belt deviation and speed fluctuation.

FIG. 16 shows an experimental result of a material of a tapering and a speed variation.

FIG. 17 shows experimental results of tapering hardness and speed fluctuation.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 photoreceptor belt drive device 2 photoreceptor belt 3 drive roller 4 driven roller 6 tension roller 8
... tension spring, 7, 7 '... arm, 9, 9' ... link, 10 ... link support point, 21, 21 '... guide, 31, 31' ...
Taper ring, 32, 32 ': drive roller rotation shaft, 33: taper ring groove, 36: taper ring protrusion, 37: drive roller groove, 38: taper ring protrusion, 41, 41': driven roller rotation shaft, 61, 61 '... tension roller rotating shaft, 71, 71' ... arm rotating shaft, 90 ... link, 91 ... link A, 92 ... link B, 93 ... fulcrum of link A and link B, 94 ... link spring,
95: Link damper, 100, 100 ': Photoconductor belt drive frame, 101: Photoconductor belt drive frame protrusion, 102: Photoconductor belt drive frame groove.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Kikuchi 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Within the Electric Appliances Division, Hitachi, Ltd. No. 1 Hitachi, Ltd.Electrical Equipment Division (72) Inventor Masafumi Suzaki 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Electrical Equipment Division (72) Inventor Katsumasa Mikami 1-1-1 Higashitaga-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Electrical Equipment Division (56) References JP-A-4-133926 (JP, A) JP-A-5-303314 (JP, A) JP-A-6-32480 (JP, A) JP-A-6-11001 (JP, A) JP-A-5-338842 (JP, A) JP-A-5-27622 (JP, A) JP-A-4-317936 JP, A) (58) investigated the field (Int.Cl. ^7, DB name) G03G 21/00 350 B65H 5/02 G03G 15/00 550

Claims (2)

(57) [Claims] A photoconductor belt; a driving roller for driving the photoconductor belt; a driven roller for bridging the photoconductor belt; a tension roller for applying tension to the photoconductor belt; In a photoreceptor belt driving device including a frame supporting a driven roller and a meandering correction device for correcting a deviation of the photoreceptor belt, the meandering correction device includes a protrusion provided on an inner peripheral surface side of the photoreceptor belt. When the photoreceptor belt is offset, the protrusions come into contact with each other.
In addition, at the shaft end of any one of the driving roller and the driven roller , the first roller can rotate independently of the first roller ,
And a ring provided is restricted to the rotation angle, rotates freely supported end of the hand to the ring end, the other <br/> end and rotatably supported to the tension roller, said ring to transmit a rotational force to the tension roller, this
The side which supports the other end of the tension roller Li
To the side of the photoreceptor belt and
A link that takes such force is reduced, the
Absorbs or attenuates the rotation of the ring to reduce the tension
A link made of a flexible member, a link divided into two, a link via a spring, or a transmission means consisting of any one of a spring. 2. A maximum outer diameter of the ring is smaller than an outer diameter of a roller provided with the ring, and a height of a protrusion formed on an inner circumference near both ends of the photoreceptor belt from the outer diameter of the roller. 2. The photoreceptor belt driving device according to claim 1, wherein the outer diameter is larger than an outer diameter obtained by subtracting twice of the outer diameter.