JP2000120720A - Rotation control device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the assembling property in the assembling of a plurality of spring clutch mechanisms within a gear train drive transmission system driven by use of the same drive source by providing a camshaft on a gear to be engaged with a rotating power output-side gear, and providing a mark for phase-fitting the spring clutch mechanism with the stop position of a cam on each gear. SOLUTION: A stepping clutch 25 is inserted to a drive transmission shaft 28, and a rotating power-side gear 54 is inserted to a D-cut part 28b on the outside of a bracket 51 for supporting the drive transmission shaft 28. A gear 59 to be engaged with the gear 54 is inserted to a D-cut part 35a on the outside of the bracket 51 for supporting a DB contact/separate camshaft 35 having a DB cut-off cam fixed thereto. Marks 54m, 59m for phase-fitting the stop position every half rotation of the stepping clutch 25 to the DB contact/separate cam are provided in the tooth position corresponding to the D-cut part 28b of the drive transmission shaft 28 and the tooth position corresponding to the D-cut part 35a of the DB contact/separate cam shaft 35 of the gears 54, 59, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic method such as a copying machine, a printer, a facsimile, etc., a mechanism for contacting and separating an image carrier and an intermediate transfer body, and an image carrier. The present invention relates to a rotation control device using a spring clutch, which is used for a contact / separation mechanism between an image transfer device and a transfer device, a mechanism for contact / separation between an intermediate transfer member and a secondary transfer device, or a mechanism for contact / separation between an intermediate transfer member and an intermediate transfer member cleaner.

[0002]

2. Description of the Related Art Conventionally, a rotation control device using a spring clutch has been used in a copying machine, a printer, a facsimile, etc., for a mechanism for moving an image carrier and an intermediate transfer member, a mechanism for moving an image carrier and a transfer device, and an intermediate mechanism. One of a contact / separation mechanism between the transfer member and the secondary transfer device, a contact / separation mechanism between the intermediate transfer member and the intermediate transfer member cleaner, or a pickup roller (half-moon feeding roller) for separating and feeding recording paper one by one Often used for rotation control. Here, FIGS. 15 and 16 show an example of the multi sheet feeding mechanism.

In FIGS. 15 and 16, the driving force of a driving gear 117 is transmitted to the half-moon feeding roller 101 via a spring clutch gear 105 and a feeding shaft 111 as a rotating force of one rotation intermittent driving. ing.

A half-moon feeding roller 101 and an eccentric cam 106 are fixed to the feeding shaft 111. Before starting feeding, the half-moon feeding roller 101 is not in contact with the separation pad 104 and is eccentric. Cam 106 is feeding plate 10
3 is pushed down to the lowest position,
Is adjusted so that the armature 118a of the solenoid 118 is caught by the notch 107a of the control ring 107, and is fixed to the sheet feeding shaft 111 by a set screw 109.

At this time, a control ring 107 and a spring retaining ring 108
The clutch spring 110 provided between the spring clutch gear 105 and the spring clutch gear 105 is loose, and the spring clutch gear 105 is free to rotate with respect to the sheet feeding shaft 111.

The sheet feeding middle plate 103 is swingably provided around a rotation shaft 122 fixed to a middle plate arm 119, and a roller 120 provided on the middle plate arm 119 is attached to the eccentric cam 106 by the middle plate addition. It is pressed by a pressure spring 121.

As shown in FIG. 17, an eccentric cam 106 has an arc portion 106 having a radius r around a paper feed shaft 111.
a is provided, and when the roller 120 is present in the arc portion 106a, the feeding plate 103 is in a state of being pushed down to the lowermost position.
1, the paper feed shaft 111 is kept in balance without rotating.

This is because, due to the nature of the spring clutch mechanism, the paper feed shaft 111 to which the eccentric cam 106 is fixed is free to rotate in the forward direction (the rotation direction of the half-moon paper feed roller) and rotates in the reverse rotation direction. Since the clutch spring 110 is tightened and the idling torque of the spring clutch gear 105 increases, the force acting on the eccentric cam 106 acts in the direction of the rotation axis of the eccentric cam 106, that is, in the direction of the paper feeding shaft 111, and the half-moon feeding roller 101 This is because it is taken into consideration that the rotation does not occur on its own or that the idling torque is not increased due to the tightening of the spring clutch 110.

[0009]

Here, the solenoid 1
When the armature 118a is sucked by energizing the power supply 18, the clutch spring 110 in the control ring 107 is disengaged from the notch 107a, and the clutch spring 110 in the control ring 107 rotates slightly in the rotation direction of the paper feed shaft 111, so that the spring clutch gear 105 and the spring Tighten the retaining ring 108. Thereby, the spring clutch gear 1
05, the control ring 107, the clutch spring 110, the spring stopper ring 108, the paper feed shaft 111, the eccentric cam 106, and the semicircular paper feed roller 101 rotate integrally.

After one rotation, the armature 11 of the solenoid 118 is inserted into the notch 107a of the control ring 107.
8a is hooked, the rotation of the control ring 107 stops, and the clutch spring 110 is loosened, so that the spring clutch gear 105 is again in a rotation-free state.

However, in the above-described conventional structure of the spring clutch mechanism and the eccentric cam, as shown in FIG. Acts in the direction of rotation of 111.

At this time, the paper feed shaft 111 and the spring stopper ring 108
Is free to rotate in the rotational force drive transmission direction.

[0013] The rotation control device having the above configuration has the following problems. That is, 1. The assemblability when combining a plurality of spring clutch mechanisms in a gear train drive transmission system driven from the same drive source is not good. 2. Due to the rotational moments H and L acting on the eccentric cam 106, the eccentric cam 106 rotates faster than normal rotation, and gives a large impact to a portion operated by the cam. 3. Due to the fast running, there is a possibility that the solenoid cannot be returned in time and rotation control cannot be performed. In particular, half a turn
80 °) The possibility is large in a controlled spring clutch mechanism. 4. In a gear train drive transmission system driven from the same drive source, there are a plurality of rotation control units using a spring clutch mechanism, and it is impossible to arrange them spatially when they are located close to each other. is there. 5. A slight reversal of the cam can tighten the spring clutch and increase idling torque.

Accordingly, it is a primary object of the present invention to provide a rotation control device having good assemblability when combining a plurality of spring clutch mechanisms in a gear train drive transmission system driven from the same drive source, and the rotation control device. An object of the present invention is to provide an image forming apparatus provided with a control device.

Another object of the present invention is to provide a rotation control device and a rotation control device which prevent a rotation due to a rotation moment acting on a cam member and do not give a large impact to a portion operated by the cam member. To provide an image forming apparatus.

It is another object of the present invention to provide a rotation control device capable of preventing rotation at a low speed and performing reliable rotation control, and an image forming apparatus provided with the rotation control device.

Another object of the present invention is to provide a rotation control device having a structure in which a plurality of spring clutch mechanisms can be arranged in the vicinity of a gear train driven by the same drive source, and an image provided with the rotation control device. It is to provide a forming device.

Another object of the present invention is to provide a rotation control device capable of preventing an increase in idling torque and an image forming apparatus provided with the rotation control device.

[0019]

The above object is achieved by a rotation control device and an image forming apparatus according to the present invention. In summary, the present invention relates to a rotation control device for controlling rotation of a cam member using a spring clutch mechanism in a gear train drive transmission system, wherein a rotation power output side provided on a shaft member of the spring clutch mechanism is provided. A first gear as a gear, a second gear meshing with the first gear, and fixed to the second gear;
A cam shaft member provided with the cam member, wherein the first and second gears are provided with a mark for phase adjustment between the spring clutch mechanism and a stop position of the cam member,
The mark is provided on the outermost side of the rotation control device.

According to another aspect of the present invention, there is provided an image forming apparatus including a rotation control device for controlling rotation of a cam member using a spring clutch mechanism in a gear train drive transmission system. A first gear as a rotational power output side gear provided on a shaft member of the spring clutch mechanism, a second gear meshing with the first gear, and the cam fixed to the second gear; A camshaft member provided with a member, wherein the first and second gears are provided with a mark for phase matching between the spring clutch mechanism and a stop position of the cam member, and the mark is provided on the first and second gears. Is provided at the outermost side of the rotation control device.

In the above invention, the spring clutch mechanism has a third gear as a rotational power input gear.
It is preferable that a fourth gear provided with a mechanism for preventing the camshaft member from rotating quickly provided on the camshaft member is provided so as to mesh with the gear. It is preferable that the cam member or the cam shaft member includes a reverse rotation preventing mechanism. It is preferable that the fourth gear be an idler gear and transmit rotational driving force to the next gear. Preferably, the spring clutch mechanism performs a half rotation control.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rotation control device and an image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

Embodiment 1 A first embodiment of the present invention will be described with reference to FIGS.

[Overall Configuration of Image Forming Apparatus] FIG. 1 is an overall configuration diagram showing an embodiment of an electrophotographic color image forming apparatus (hereinafter, simply referred to as "image forming apparatus") according to the present invention.

First, an overall configuration of the image forming apparatus A will be schematically described with reference to FIG. The image forming apparatus A shown in FIG. 1 is a four-color laser beam printer.

The image forming apparatus A includes a drum type electrophotographic photosensitive member (hereinafter, referred to as “photosensitive drum”) 1. The photosensitive drum 1 is driven by a driving unit (not shown).
In the same figure, it is driven to rotate counterclockwise. Photoconductor drum 1
Around the photosensitive drum 1 in order according to the rotation direction.
A charging device 2 for uniformly charging the surface; an exposure unit 3 for irradiating a laser beam based on image information to form an electrostatic latent image on the photosensitive drum 1; and attaching toner to the electrostatic latent image to form a toner image A developing device 4 for developing, an intermediate transfer unit 5 to which a toner image on the photosensitive drum 1 is primarily transferred, a cleaning device 6 for removing post-transfer toner remaining on the surface of the photosensitive drum 1 after the primary transfer, and the like are provided. ing.

Here, the photosensitive drum 1, the charging device 2, and the cleaning device 6 are integrally formed into a cartridge to form a process cartridge B, and the image forming apparatus main body 1
4 is detachable.

In addition, a recording medium (transfer material) S is fed toward the intermediate transfer unit 5, and a feeding / conveying means 7 for conveying the transfer material S, and a toner image is formed on the transfer material S after the secondary transfer. A fixing device 8 for fixing is provided.

Hereinafter, the components constituting the image forming apparatus will be described in more detail.

The photosensitive drum 1 is provided with an organic photoconductor (OP) on an outer peripheral surface of, for example, an aluminum cylinder having a diameter of 47 mm.
C photoreceptor), and both ends thereof are rotatably supported by support members, and a driving force from a drive motor (not shown) is transmitted to one end, It is driven to rotate in the direction of the arrow.

The charging device 2 is described in, for example,
A so-called contact charging type as shown in JP-A-149669 can be used. The charging member is a conductive roller formed in the shape of a roller. The roller is brought into contact with the surface of the photosensitive drum 1, and a charging bias voltage is applied to the roller by a power supply (not shown). This is to uniformly charge the surface of the body drum 1.

The exposure means 3 has a polygon mirror 3a, and the polygon mirror 3a is irradiated with image light corresponding to an image signal by a laser diode (not shown). The polygon mirror 3a is rotated at a high speed by a scanner motor (not shown), and selectively exposes the surface of the charged photosensitive drum 1 to the reflected image light via the imaging lens 3b, the reflection mirror 3c, etc. It is configured to form an electrostatic latent image.

The developing device 4 contains a rotating member 4A rotatable around a shaft 4d and four developing devices mounted thereon, that is, toners of yellow, magenta, cyan and black, respectively. Developing units 4Y, 4M, 4
C, 4Bk.

When the electrostatic latent image on the photosensitive drum 1 is developed, a predetermined developing device of a color to be attached to the electrostatic latent image is positioned at a developing position. That is, the predetermined developing device is
After being stopped at the developing position facing the photosensitive drum 1 by the indexing rotation of A, the developing sleeve 4b of the developing device is positioned so as to face the photosensitive drum 1 with a small gap (about 300 μm). The electrostatic latent image on the photosensitive drum 1 is developed.

This development is performed as follows. That is, the feeding mechanism 4e feeds the toner in the container of the developing device corresponding to the color to be developed.
The toner is applied to the outer periphery of the rotating developing sleeve 4b by the rotating applying roller 4a and the toner regulating blade 4c, and a charge is applied to the toner (friction charging).

By applying a developing bias between the developing sleeve 4b and the photosensitive drum 1 on which the electrostatic latent image is formed, toner is adhered to the electrostatic latent image and developed as a toner image. is there. Further, each of the developing units 4Y, 4M, 4
The developing sleeve 4b of C, 4Bk is connected to a high-voltage power source for developing each color provided in the image forming apparatus main body 14 when each developing unit is arranged at the developing position, and develops each color. A voltage is selectively applied every time. Each of the developing devices 4Y, 4M, 4C, and 4Bk is configured to be individually detachable from the rotating body 4A.

The intermediate transfer unit 5 transfers a plurality of toner images which are sequentially primary-transferred from the photosensitive drum 1 and are superimposed on each other.
The secondary transfer is performed on the transfer material S in a lump.

The intermediate transfer unit 5 has an intermediate transfer belt 5a running in the direction of arrow R5. The intermediate transfer belt 5a of this embodiment is a belt having a circumference of about 440 mm,
It is stretched over three rollers: a driving roller 5b, a secondary transfer opposing roller 5c, and a driven roller 5d. Further, there is provided a primary transfer roller 5j which retreats so as to take a position where the intermediate transfer belt 5a is pressed against the photosensitive drum 1 close to the driven roller 5d and a position where the intermediate transfer belt 5a is separated from the photosensitive drum 1. .

The intermediate transfer belt 5a runs in the direction of arrow R5 by the rotation of the driving roller 5b. Further, at a predetermined position outside the intermediate transfer belt 5a, that is, downstream of the secondary transfer opposing roller 5c, there is provided a cleaning unit 5e which can be brought into contact with and separated from the surface of the intermediate transfer belt 5a. Remove residual toner.

The cleaning unit 5e brings the charging roller 5f into contact with the intermediate transfer belt 5a to give the toner a charge opposite to that at the time of transfer. The toner to which the opposite charge has been applied is electrostatically attached to the photosensitive drum 1 and thereafter collected by the cleaning device 6 for the photosensitive drum 1. The method of cleaning the intermediate transfer belt 5a is not limited to the above-described electrostatic cleaning, but may be a mechanical method such as a blade or a fur brush, or a method using both of them.

After the toner developed on the photosensitive drum 1 by the developing device 4 is primarily transferred to the intermediate transfer belt 5a, the cleaning device 6 is a so-called untransferred toner remaining on the surface of the photosensitive drum 1 without being primarily transferred. Is to be removed. In the cleaning device 6 for the photosensitive drum 1, the transfer residual toner is accumulated in the cleaning container 11a.

The feeding means 7 feeds the transfer material S to the image forming section, and stores a plurality of transfer materials S. At the time of image formation, a pickup roller (half moon feeding roller) 7e, a feed roller 7f, and a retard roller 7
g is driven and rotated in accordance with the image forming operation, and the paper feed cassette 7 is rotated.
The transfer material S in a is separated by one sheet, and is transported along the guide plate 7c by the transport roller pair 7b. The leading end of the transfer material S abuts against the pair of registration rollers 7d, temporarily stops, forms a loop, and synchronizes the rotation of the intermediate transfer belt 5a with the image writing position to form a pair of registration rollers 7d.
Is fed again to the intermediate transfer member 5.

The fixing device 8 fixes a plurality of toner images secondary-transferred onto the transfer material S. As shown in FIG. 1, a heating roller 8b, which is driven and rotated, is pressed against the transfer material S to press the transfer material S. And a pressure roller 8a for applying heat and pressure to the pressure roller 8a. That is, the transfer material S that has passed through the secondary transfer roller 11 that collectively transfers the toner on the intermediate transfer belt 5a is transported on the transport belt unit 12, and when passing through the fixing device 8, the pressure roller 8a and the heating roller 8b And heat and pressure are applied by the heating roller 8b. Thus, the toner images of a plurality of colors are fixed on the surface of the transfer material S.

[Outline of Image Forming Operation of Image Forming Apparatus] The photosensitive drum 1 is rotated in the direction of the arrow (counterclockwise) in FIG. 1 in synchronization with the rotation of the intermediate transfer belt 5a, and the surface of the photosensitive drum 1 is rotated. While being uniformly charged by the charging device 2, light exposure of a yellow image is performed by the exposure unit 3,
A yellow electrostatic latent image is formed on the photosensitive drum 1. Simultaneously with the formation of the electrostatic latent image, the developing device 4 is driven to position the yellow developing device 4Y at the developing position, and the photosensitive drum 1
A voltage having the same polarity and substantially the same potential as the charging polarity of the photosensitive drum 1 is applied so that the yellow toner is attached to the upper electrostatic latent image, and the yellow toner is attached to the electrostatic latent image for development.
Thereafter, a voltage having a polarity opposite to that of the toner is applied to the primary transfer roller 5j of the intermediate transfer member 5 to primarily transfer the yellow toner image on the photosensitive drum 1 onto the intermediate transfer belt 5a.

When the primary transfer of the yellow toner image is completed as described above, the next developing unit 4M, 4C, or 4Bk
Is rotated and positioned at the developing position facing the photosensitive drum 1, and in the same manner as in the case of yellow, formation of an electrostatic latent image, development, and primary transfer are sequentially performed for each of the colors magenta, cyan, and black. , Intermediate transfer belt 5
The four color toner images are superimposed on a.

In the meantime, the cam 18 of the secondary transfer roller 11 provided at a predetermined position outside the intermediate transfer belt 5a so as to be able to come into contact with and separate from the surface of the intermediate transfer belt 5a is 180 ° in FIG.
゜ It is in a rotated state and is in a non-contact state with the intermediate transfer belt 5a.

Further, at another predetermined position of the intermediate transfer belt 5a, the charging roller 5f of the cleaning unit 5e provided so as to be able to contact and separate from the surface of the intermediate transfer belt 5a is also in a non-contact state with the intermediate transfer belt 5a. I have.

After the formation of the four color toner images on the intermediate transfer belt 5a, the secondary transfer roller 11 is pressed against the intermediate transfer belt 5a (the state shown in FIG. 1), and further in synchronization with the rotation of the intermediate transfer belt 5a. And transfer material loading means (cassette) 1
4, the pickup roller 7e and the retard roller 7
g, the transfer material S that has been separated and fed one by one by the feed roller 7f and is waiting at a predetermined position near the registration roller pair 7d is sent out to the nip portion between the intermediate transfer belt 5a and the secondary transfer roller 11.

Here, immediately before the registration roller pair 7d, the leading edge of the transfer material S is detected, the rotational driving force of the registration roller pair 7d is shut off, and the registration sensor (19a) for causing the transfer material S to wait at a predetermined position. , 19b) 19 are provided.

Further, a voltage having a polarity opposite to that of the toner is applied to the secondary transfer roller 11, and the toner image on the intermediate transfer belt 5a is secondarily transferred onto the surface of the transfer material S which has been conveyed at once. I will do it.

After the secondary transfer to the transfer material S is performed at once, the cleaning unit 5e is moved to the charging roller 5f.
Is brought into contact with the intermediate transfer belt 5a to apply an opposite charge to the toner at the time of transfer. The oppositely charged toner is electrostatically attached to the photosensitive drum 1 and then collected by the cleaning device 6 for the photosensitive drum 1 to remove the remaining transfer residual toner.

The transfer material S subjected to the secondary transfer in this manner is
Reaches the fixing device 8 via the conveyor belt units 12a and 12b, where the fixing of a plurality of color toner images is performed.
The sheet is conveyed along the sheet ejection guide 15 by the sheet ejection roller pairs 13 and 16 and is ejected to the sheet ejection tray 10 above the image forming apparatus A by the ejection roller pair 9 to complete the image formation.

[Mechanism of Contact and Separation of Intermediate Transfer Belt to Photoconductor Drum] The mechanism of contact and separation of the photoconductor drum and the intermediate transfer belt (DB) will be described with reference to FIGS.

FIG. 2 shows the position of the intermediate transfer unit 5 in the non-image forming state, and shows a state where the intermediate transfer unit 5 is inserted and mounted to a predetermined position of the apparatus main body 14. At this time, the photosensitive drum 1, the intermediate transfer belt 5a,
The secondary transfer roller 31 and the charging roller 5f are separated from each other.

FIG. 3 shows the position of the intermediate transfer unit 5 during the primary transfer. At this time, the intermediate transfer belt 5 a is in contact with the photosensitive drum 1, and the secondary transfer roller 31 and the charging roller 5 f are separated from the intermediate transfer body 5.

In FIG. 1, the intermediate transfer belt 5a contacts the photosensitive drum 1, the secondary transfer roller 31 contacts the intermediate transfer belt 5a, the charging roller 5f separates, and the transfer material S This shows a state where a toner image is being transferred.

In FIG. 2, a photosensitive drum / intermediate transfer belt contact / separation lever (hereinafter, referred to as a “DB contact / separation lever”) 3
1 is provided so as to be swingable about a swing shaft 32, and is in contact with a photosensitive drum / intermediate transfer belt contact / separation cam (hereinafter referred to as “DB contact / separation cam”) 34 by a tension spring 33 on a cam slide surface 31 a. The swing shaft 32 is pressed against one end of a swing shaft hole 36.

The DB contact / separation cam 34 is provided on the DB contact / separation cam shaft 35, makes a half turn in the direction of the arrow, and stops in the state shown in FIG.

At this time, the cam slide surface 31 a of the DB contact / separation lever 31 is moved by the tension spring 3
3, the other end 31b of the DB contact / separation lever 31 is pivoted about the pivot shaft 32 so that the other end 31b of the DB transfer / separation lever 31 is coaxial with the secondary transfer opposing roller 5c of the intermediate transfer unit 5. 5, lift the support shaft 5n provided at both ends,
The intermediate transfer belt 5a is pressed against the photosensitive drum 1 at the position of the primary transfer roller 5j.

The swing shaft hole 36 of the DB separation lever 31 is an elongated hole, and the intermediate transfer belt 5a is pressed against the photosensitive drum 1 at the position of the primary transfer roller 5j as shown in FIG. The swing shaft 32 is located in the middle of the elongated hole 36, and the DB contact / separation lever 31 presses the intermediate transfer belt 5a against the photosensitive drum 1 with a predetermined pressure by the tension of the tension spring 33.

[Mechanism for Contacting and Separating the Cleaning Device from the Intermediate Transfer Belt] As shown in FIGS. 4 to 7, the intermediate transfer unit 5 includes a cleaning device 5e provided on the surface of the intermediate transfer belt 5a so as to be able to contact and separate. Is disposed on the insertion side of the apparatus main body 14.

The charging roller 5f is a cleaning roller (hereinafter referred to as “IC”) that is swingably provided around the rotation shaft 5g.
L), the ICL oscillating plate 5m is pulled by a tension spring 5k when the intermediate transfer unit 5 is not pushed into a predetermined position of the apparatus main body 14, as shown in FIG. As a result, the surface of the intermediate transfer belt 5a is pressed with a predetermined pressure.

From the position shown in FIG. 4 to the position shown in FIG. 5, that is,
Pulling out the intermediate transfer unit 5 from the apparatus main body 14
7 and pushed into the apparatus main body 14 together with the drawer movable body 17 to move the ICL rocking plate 5m to a position where it comes into contact with the ICL contact / separation cam 20 provided in the apparatus main body 14.
The ICL rocking plate 5m rocks clockwise in FIG. 5 around the rotating shaft 5g against the tension of the tension spring 5k, and when the intermediate transfer unit 5 is mounted at a predetermined position as shown in FIG. Then, the charging roller 5f is completely retracted from the intermediate transfer belt 5a to a predetermined position.

In FIG. 7, the ICL contact / separation cam 20 is
The center of the circular arc portion 20a abutting on the L rocking plate 5m is IC
L is provided at C below the rotation center 21 of the L contact / separation cam 20, and I
Vector N of acting force (vertical drag) from CL rocking plate 5m
Are provided so as to pass through the arc center C. As a result, a rotational moment NL1 in the direction of arrow A (reverse rotation) about the rotation shaft 21 acts on the ICL contact / separation cam 20, but
Arrow A by the action of the one-way clutch provided on the rotating shaft 21
It does not rotate in any direction. The one-way clutch will be described later.

The intermediate transfer unit 5 swings around the rotation drive shaft 5b of the intermediate transfer belt 5a, and repeats the states shown in FIGS. 2 and 3, but the ICL swing plate 5m is moved as shown in FIG. It is provided to move in a direction substantially perpendicular to the vector N. Thereby, the ICL contact / separation cam 20 and the IC
Assuming that the friction coefficient of the L rocking plate 5m is μ, the sliding motion of the ICL rocking plate 5m causes the ICL contacting / separating cam 20 to rotate the rotation moment R about the rotating shaft 21 as R = μNcos θ ·
L2 acts. Here, θ is the angle between the line connecting the cam rotation center and the contact point and the line connecting the cam arc center and the contact point, and L2 is the distance from the cam rotation center to the contact point between the cam and the rocking plate.

F = μN is minimized and R = μNcos
The normal force N from the ICL rocking plate 5m generated by the tension spring 5k is set so that θ · L2 becomes smaller than the rotational moment NL1 due to the normal force N from the ICL rocking plate 5m.
Is determined.

Further, the ICL contact / separation cam 20 is made of a resin such as POM so that the friction coefficient μ between the ICL contact / separation cam 20 and the ICL rocking plate 5m is reduced, so that the following equation (1) is satisfied. I do.

NL1> R = μNcos θ · L2 (1) Accordingly, the intermediate transfer unit 5 swings from the state shown in FIG. 2 to the state shown in FIG. Even if a rotational moment in the direction of arrow B (forward direction) of μNcos θ · L2 acts, the ICL contact / separation cam 20 can keep a predetermined position without rotating in the forward direction.

When the ICL contact / separation cam shaft 21 provided with the ICL contact / separation cam 20 is rotated by half a rotation and stopped in the state shown in FIG. 6, the ICL rocking plate 5m rocks around the rotation shaft 5g and pulls. The charging roller 5f is pressed against the intermediate transfer belt 5a at a predetermined pressure by a spring 5k.

[Second Transfer Mechanism of Secondary Transfer Apparatus to Intermediate Transfer Belt] The secondary transfer apparatus contact / separation cam (hereinafter referred to as “2TR contact / separation cam”) 18 is rotated by half a turn in the direction of the arrow from the state shown in FIG. 8, the positioning abutting portions 41 provided at both ends of the secondary transfer frame 40 provided with the secondary transfer roller 11 are fixed to the positioning abutting portions 42 of the intermediate transfer unit 5. You. Further, the secondary transfer frame 4
0, bearings 43 at both ends are provided so as to be movable substantially parallel to the transfer material transport direction, and the secondary transfer frame 40 follows the positioning of both ends of the intermediate transfer unit 5 so that the secondary transfer frame 40 The secondary transfer frame 4 is positioned with respect to the intermediate transfer unit 5 and parallelized in the axial direction.
Positioning of the secondary transfer roller 11 that can move in a substantially vertical direction on the zero is performed.

Further, the secondary transfer frame 40 is pushed up by a compression spring 45 via a pressure plate 44, and
4 moves up and down every half rotation of the 2TR contact / separation cam 18, thereby absorbing variations in the mounting position of the intermediate transfer unit 5 or the secondary transfer device, and always keeping the position of the secondary transfer roller 11 with respect to the intermediate transfer unit 5 constant. Holding.

As a result, the secondary transfer roller 11 is pressed by the compression spring 46 against the intermediate transfer belt 5a at a constant pressure.

[DB contact / separation cam, ICL contact / separation cam, 2TR
Rotational power transmission mechanism of contact / separation cam] FIG.
The rotation power transmission mechanism for each half rotation of the 4.ICL contact / separation cam 20 / 2TR contact / separation cam 18 is viewed from the top of the apparatus main body. FIG. 11 shows a view from the side of the apparatus main body.

The rotary power transmission mechanism of this embodiment is disclosed in
No. 1-54969 has a structure in which a spring clutch and an electromagnetic solenoid are integrated, and a half rotation (1
80 °) Stepping clutch 2 for controlling rotation every time
5, 26 and 27 are provided.

The stepping clutch 25 has a third gear 25a as a rotational power input gear (clutch gear) that is free to rotate rightward in the drawing, is inserted into the D-cut portion 28a of the drive transmission shaft 28, and has a projection. The rotation is stopped at 25b.

The drive transmission shaft 28 is rotatably supported by a bearing 52 provided on the left side plate 50 of the main body and a bearing 53 provided on the bracket 51. A D-cut portion 28b outside the bracket 51 serves as a rotational power output gear. First gear 5
4 is inserted.

The DB contact / separation cam shaft 35 to which the DB contact / separation cam 34 is fixed is constituted by a bearing 55 provided on the left side plate 50 of the main body, a bearing 57 provided on the right side plate 56 of the main body, and a bearing 58 provided on the bracket 51. It is rotatably supported.

A second gear 59 is inserted into the D cut portion 35 a outside the bracket 51 of the DB contact / separation cam shaft 35 so as to mesh with the first gear 54.

The third gear 2 is connected to the DB contact / separation cam shaft 35.
A fourth gear 60 is provided to mesh with 5a.

Here, the first gear 54 and the second gear 5
9, the third gear 25a and the fourth gear 60 have the same number of teeth.

The fourth gear 60 is locked to prevent the DB contact / separation cam shaft 35 from rotating with respect to the fourth gear 60 in the direction shown by the arrow in FIGS. One-way clutch 60a is provided. That is, the fourth gear 60 is configured to be rotatable in the left rotation direction with respect to the DB contact / separation cam shaft 35, and locked in the right rotation direction so as not to rotate.

Further, the main body right side plate 5 of the DB contact / separation cam shaft 35
The bearing 57 on the sixth side is provided with a one-way clutch 61 that locks the rotation of the DB contact / separation cam shaft 35 in the clockwise direction.

Here, it is necessary to match the stop position of the stepping clutch 25 every half rotation with the phase of the DB contact / separation cam 34.

Therefore, the first gear 54 and the second gear 59
The phase matching marks (marks) are provided at a predetermined tooth position of the drive transmission shaft 28 with respect to the D-cut portion 28b and a predetermined tooth position of the DB contact / separation cam shaft 35 with respect to the D-cut portion 35a.
54 m and 59 m are provided, and the stop position for each half rotation of the stepping clutch 25 and the DB contact / separation cam
4 can be adjusted.

As described above, the phase alignment marks 54m, 5m
By providing 9 m on the outermost side of the device, assemblability when combining a plurality of spring clutch mechanisms as in this embodiment can be improved.

The fourth gear 60 has an idler gear 6
2 and the idler gear 62 is meshed with a clutch gear 26a as a rotational power input side gear that is free to rotate in the clockwise direction of the stepping clutch 26.

The stepping clutch 26 is inserted into the D-cut portion 21a of the ICL contact / separation cam shaft 21 to which the ICL contact / separation cam 20 is fixed, and is prevented from rotating by the protrusion 26b. The ICL contact / separation camshaft 21 is rotatably supported by a bearing 63 provided on the left main body plate 50 and a bearing 64 provided on the right main body plate 56.

Further, a one-way clutch 65 for locking the rotation of the ICL contact / separation camshaft 21 in the clockwise direction is provided on a bearing 64 on the right side plate 56 side of the main body of the ICL contact / separation camshaft 21.
Is provided.

On the other hand, as a gear train branched from the clutch gear (third gear) 25 a of the stepping clutch 25, three idler gears 66, 67, 68 are engaged and connected, and the stepping clutch 27 is free to rotate in the clockwise direction. Clutch gear 27 as rotational power input side gear
a to transmit rotational power.

The stepping clutch 27 is inserted into a D-cut portion 47a of a 2TR contact / separation cam shaft 47 to which the 2TR contact / separation cam 18 is fixed, and is prevented from rotating by a projection 27b. The 2TR contact / separation camshaft 47 includes a bearing 66 provided on the left main body plate 50 and a bearing 6 provided on the right main body plate 56.
7 rotatably supported.

Further, a one-way clutch 69 that locks the rotation of the 2TR contact / separation cam shaft 47 in the left rotation direction is provided on a bearing 67 of the 2TR contact / separation cam shaft 47 on the right side plate 56 side of the main body.
Is provided.

[DB cam / ICL cam / 2TR]
Rotational power transmission operation of contact / separation cam] In the above configuration, the rotational power is supplied from a drive source (not shown) at a constant rotational speed to the third gear 25a as the rotational power input side gear (clutch gear) of the stepping clutch 25. Direction (clockwise rotation).

When the energization of the electromagnetic solenoid 25e of the stepping clutch 25 is OFF, the third clutch gear 25a acts as a clockwise idler gear, and applies rotational power to the fourth gear 60 (left rotation) and the idler gear 62 ( Clockwise), the clutch gear 26a of the stepping clutch 26
(To the left).

At this time, the built-in one-way clutch 60a of the fourth gear 60 is free to rotate leftward with respect to the DB contact / separation shaft 35 and locked in the rightward rotation direction.
Acting as an idler gear.

The power to the electromagnetic solenoid 26e of the clutch gear 26a of the stepping clutch 26 is turned off.
At this time, it is rotating as a counterclockwise idler gear.

The idler gear 66 (left rotation) branched from the third gear 25a as the rotational power input gear (clutch gear) of the stepping clutch 25 includes an idler gear 67 (right rotation), an idler gear 68 (left rotation), and a stepping clutch. The rotation power is transmitted to the clutch gear 27a (clockwise rotation) of the clutch gear 27.

When the power to the electromagnetic solenoid is turned off, the clutch gear 27a of the stepping clutch 27 is turned off.
It rotates as a right-handed idler gear.

Now, when the energization of the electromagnetic solenoid 25e of the stepping clutch 25 is changed from the OFF state to the ON state and the flapper section 25d is sucked, the third gear 25a as the rotational power input side gear (clutch gear) is pulled. Rotational force is transmitted to a first gear 54 (clockwise rotation) as a rotational power output gear, and leftward rotation torque is transmitted to the DB contact / separation camshaft 35 via a second gear 59 (left rotation). You.

As described in Japanese Patent Application Laid-Open No. 61-54969, the stepping clutch 25 rotates half a turn from the previous energized OFF state with the flapper section 25d being suctioned in the energized ON state. Stop and hold this state.

After half a rotation (180 °), the third clutch gear 25a rotates again as a clockwise idler gear.

Therefore, the DB contact through the DB contact / separation cam shaft 35
The contact / separation cam 34 makes a half rotation from the state of FIG. 2 to the state of FIG. 3, and holds the state where the DB contact / separation lever 31 presses the intermediate transfer belt 5a against the photosensitive drum 1 with a predetermined pressure.

Similarly, the energization of the electromagnetic solenoid 26e of the stepping clutch 26 is changed from the OFF state to the ON state.
In this state, the rotational force of the left rotation is transmitted to the ICL contact / separation camshaft 21 as the rotational power output from the clutch gear 26a (left rotation) as the rotational power input gear, and the charging roller 5
f is kept pressed against the intermediate transfer belt 5a with a predetermined pressure.

When the energization of the electromagnetic solenoid of the stepping clutch 27 is changed from the OFF state to the ON state, the clutch gear 27a (clockwise rotation) is used as the rotational power input side gear.
The rotational force of the right rotation is transmitted to the 2TR contact / separation cam shaft 47 as a rotational power output, and the 2TR contact / separation cam 18 makes a half turn from the state of FIG. 3 to the state of FIG.
1 is kept pressed against the intermediate transfer belt 5a with a predetermined pressure.

Here, the one-way clutches 61, 65, and 6 as reverse rotation preventing mechanisms provided on the DB contact / separation cam shaft 35, the ICL contact / separation cam shaft 21, and the 2TR contact / separation cam shaft 47.
8, each camshaft generates a reverse rotation force due to the drag from the cam,
The spring clutch of each stepping clutch is tightened to prevent the torque from increasing.

The DB contact / separation cam mechanism, the ICL contact / separation cam mechanism, and the 2TR contact / separation cam mechanism include the DB contact / separation cam mechanism,
When the energizing state of the electromagnetic solenoid of the stepping clutch 27 changes from OFF to ON, the TR contact / separation cam mechanism begins to act on the contact / separation cam 18 from the non-driving unit,
In the ON state, a drag acts on the contact / separation cam 18.

In the ICL contact / separation cam mechanism, the ON state of the electromagnetic solenoid 26e of the stepping clutch 26
When it is turned on from F, the drag from the non-driving unit with respect to the contact / separation cam 20 begins to decrease, and the contact / separation cam 20 loses the drag in the ON state. In other words, the operation status of the cam is opposite to that of the DB contact / separation cam mechanism.

Conversely, when the energization of the electromagnetic solenoid 25e of the stepping clutch 25 is changed from the ON state to the OFF state to open the flapper section 25d, the rotational power is again transmitted from the third gear 25a as the rotational power input side gear (clutch gear). The rotational force is transmitted to the first gear 54 (clockwise rotation) as the output gear, and the rotational force is transmitted to the DB contact / separation camshaft 35 via the second gear 59 (leftward rotation). Then, the state returns to the state shown in FIG.

At this time, as shown in FIG. 9, while the DB contact / separation cam 34 is returning to the previous state, the DB contact / separation cam 34
A large drag is generated by the tension spring 33 and the intermediate transfer unit 5 from the contact / separation lever 31, and the moment force causes
The contact / separation cam shaft 35 makes a rapid turn in the rotation direction (left rotation direction), and the rotation speed increases. The first gear 54 serving as the rotation power output side gear of the stepping clutch 25 via the second gear 59. (Clockwise), and the increase in the rotation speed is transmitted to the rotation control plate 25c of the stepping clutch 25.

Thus, the rotation control plate 25 shown in FIG.
When the rotation speed of c becomes faster than the return time of the flapper portion 25d of the electromagnetic solenoid portion 25e of the stepping clutch 25, the half rotation control cannot be performed, and the DB contact / separation cam shaft 35, that is, the DB contact / separation cam 34, rotates half a turn. The problem that rotation continues without stopping occurs. This is a problem that occurs because the spring clutch mechanism is structurally free to rotate in the rotation transmitting direction, as described above.

Therefore, the third spring clutch gear 25a as the rotational power input gear of the stepping clutch 25
The above-described one-way clutch gear 60a is provided inside the fourth gear 60 that meshes with the first gear 60. When the DB contact / separation cam shaft 35 attempts to rotate faster than a predetermined rotation speed, the normal speed rotation from the third spring clutch gear 25a is used. The structure is such that the brake acts to suppress an increase in the rotation speed of the DB contact / separation cam shaft 35.

Accordingly, it is possible to prevent a problem that the intermediate transfer belt 5a gives an impact to the photosensitive drum 1 due to the speed rotation of the DB contact / separation cam 34.

Similarly, when the energization of the electromagnetic solenoid 26e of the stepping clutch 26 is changed from the ON state to the OFF state, the ICL contact / separation camshaft is output as the rotational power output from the clutch gear 26a (left rotation) as the rotational power input gear. The rotation force of the left rotation is transmitted to 21, and the ICL contact / separation cam 20 makes a half turn from the state of FIG. 6 and returns to the state of FIG.
The state where the charging roller 5f is separated from the intermediate transfer belt 5a is maintained.

When the energization of the electromagnetic solenoid of the stepping clutch 27 is changed from the ON state to the OFF state, the clutch gear 27a (rotating clockwise) as the rotational power input side gear rotates the rotational power output to the 2TR connection / separation cam shaft 47 to the right. The rotation force of the rotation is transmitted, and the 2TR contact / separation cam 18 makes a half rotation from the state of FIG. 8 to the state of FIG. 3, and holds the state where the secondary transfer roller 11 is separated from the intermediate transfer belt 5a.

Embodiment 2 In the first embodiment, a structure in which a spring clutch and an electromagnetic solenoid are integrated as shown in Japanese Patent Application Laid-Open No. 61-54969 is used as a spring clutch mechanism for controlling rotation every half rotation. ON / OF for energizing the electromagnetic solenoid
In the state of F, a so-called stepping clutch that performs rotation control every half rotation (180 °) is used. In addition to the first embodiment, as a spring clutch mechanism that performs half rotation rotation control, as shown in FIG. By displacing the position of the control ring 200 and providing two projections 201 and 202 at an interval of 180 °, the flapper 204 of the electromagnetic solenoid 203 is sucked and opened by turning ON / OFF the power supply to the electromagnetic solenoid. Half rotation control can also be performed by hooking on the protrusion 201 or the protrusion 202.

Embodiment 3 In the above-described embodiment, the one-way clutch 60a is provided inside the fourth gear 60 as the anti-rotation mechanism, but as shown in FIG. 14, the one-way clutch 60a is engaged with the third gear 25a. An idler gear 205 provided on the DB separation cam shaft 35;
A structure in which a toothless gear 206 that starts meshing with the third gear 25a by the rotation of the B separation cam shaft 35 may be provided.

At this time, the missing tooth gear 206 meshes with the third gear 25a only when returning from the state of FIG. 3 to the state of FIG.

[0117]

As is apparent from the above description, according to the rotation control device and the image forming apparatus of the present invention, the first gear as the rotational power output side gear provided on the shaft member of the spring clutch mechanism is provided. A second gear meshing with the first gear, and a camshaft member fixed to the second gear and provided with a cam member, wherein the first and second gears include the spring A mark for phase matching between the clutch mechanism and the stop position of the cam member is provided, and the mark is provided on the outermost side of the rotation control device, so that a gear train drive transmission system driven from the same drive source Among them, the assemblability when combining a plurality of spring clutch mechanisms can be improved.

Further, the spring clutch mechanism has a third gear as a rotational power input gear, and the third gear has a mechanism for preventing the cam shaft member from rotating quickly provided on the cam shaft member. The fourth gear provided is provided so as to mesh with the gear member, thereby preventing a fast rotation caused by a rotational moment acting on the cam member, preventing a large shock from being applied to a portion operated by the cam member, and further reducing the speed. Rotation can be prevented and rotation control can be reliably performed.

Further, since the cam member or the camshaft member is provided with a reverse rotation preventing mechanism, an increase in idling torque can be prevented.

Further, since the fourth gear is configured as an idler gear to transmit a rotational driving force to the next gear, a plurality of gears can be provided in a gear train drive transmission system driven from the same drive source. The spring clutch mechanism of
The size of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a color image forming apparatus according to the present invention.

FIG. 2 is a side view illustrating a positional relationship among a DB contact / separation cam, an ICL contact / separation cam, and a 2TR contact / separation cam during non-image formation.

FIG. 3 is a side view showing a positional relationship among a DB contact / separation cam, an ICL contact / separation cam, and a 2TR contact / separation cam during image formation.

FIG. 4 is an explanatory diagram illustrating a state in which an intermediate transfer unit is pulled out of the apparatus.

FIG. 5 is an explanatory view showing a state in which an ICL contact / separation cam operates.

FIG. 6 is an explanatory diagram showing a state where an ICL contact / separation cam is not operated.

FIG. 7 is an explanatory diagram showing a working relationship of a force when the ICL contact / separation cam is not working.

FIG. 8 is an explanatory view showing a state in which a 2TR contact / separation cam operates.

FIG. 9 is an explanatory view showing a DB contact / separation cam and members related thereto.

FIG. 10 is a plan view showing a gear train drive system that controls the rotation of each contact / separation cam of DB, ICL, and 2TR by a stepping clutch.

FIG. 11 is a side view showing a gear train drive system that controls rotation of each of the contact / separation cams of DB, ICL, and 2TR by a stepping clutch.

FIG. 12 is a side view showing a mechanism for driving each of the contact / separation cams of DB, ICL, and 2TR.

FIG. 13 is an explanatory view showing a spring clutch mechanism according to a second embodiment of the present invention.

FIG. 14 is an explanatory view showing a fast-turn prevention mechanism according to a third embodiment of the present invention.

FIG. 15 is a perspective view showing a multi-sheet feeding mechanism using a conventional rotation control device.

FIG. 16 is a side view of the multi-sheet feeding mechanism of FIG.

FIG. 17 is an enlarged view of a main part when the multi-sheet feeding mechanism of FIG. 15 is not operated.

FIG. 18 is an enlarged view of a main part when the multi-sheet feeding mechanism of FIG. 15 is operated.

[Explanation of symbols]

Reference Signs List 18 Intermediate transfer member / secondary transfer roller (2TR) contact / separation cam 20 Intermediate transfer member / cleaning roller (ICL) contact / separation cam 21 ICL contact / separation cam shaft 25, 26, 27 Stepping clutch 25a Third gear 34 Photoconductor drum -Intermediate transfer member (DB) contact / separation cam 35 DB contact / separation cam shaft 54m, 59m Mark (mark) 59 Second gear 60 Fourth gear 60a, 61, 65, 68 One-way clutch

Claims (10)

[Claims] 1. A rotation control device for controlling rotation of a cam member using a spring clutch mechanism in a gear train drive transmission system, wherein a rotation power output gear provided on a shaft member of the spring clutch mechanism is provided. A first gear, a second gear meshing with the first gear, and a camshaft member fixed to the second gear and provided with the cam member, wherein the first and second gears are provided. A rotation control device, wherein the gear is provided with a mark for phase adjustment between the spring clutch mechanism and the stop position of the cam member, and the mark is provided on the outermost side of the rotation control device. 2. The spring clutch mechanism has a third gear as a rotary power input gear, and the third gear includes a cam shaft member rotation preventing mechanism provided on the cam shaft member. The rotation control device according to claim 1, wherein the fourth gear provided is provided so as to mesh with the fourth gear. 3. The rotation control device according to claim 1, wherein the cam member or the cam shaft member includes a reverse rotation prevention mechanism. 4. The rotation control device according to claim 2, wherein said fourth gear is an idler gear and transmits a rotational driving force to a next gear. 5. The rotation control device according to claim 1, wherein the spring clutch mechanism performs a half rotation control. 6. An image forming apparatus comprising a rotation control device for controlling rotation of a cam member using a spring clutch mechanism in a gear train drive transmission system, wherein the rotation control device includes a shaft of the spring clutch mechanism. A first gear as a rotational power output gear provided on the member,
A second gear meshing with the first gear; and a cam shaft member fixed to the second gear and provided with the cam member. The first and second gears each include a spring. An image forming apparatus, wherein a mark for phase matching between a clutch mechanism and a stop position of the cam member is provided, and the mark is provided on the outermost side of the rotation control device. 7. The spring clutch mechanism has a third gear as a rotational power input gear, and the third gear includes a cam shaft member rotation preventing mechanism provided on the cam shaft member. The image forming apparatus according to claim 6, wherein the fourth gear provided is provided so as to mesh with the fourth gear. 8. The image forming apparatus according to claim 6, wherein the cam member or the cam shaft member includes a reverse rotation preventing mechanism. 9. The image forming apparatus according to claim 7, wherein the fourth gear transmits a rotational driving force to a next gear as an idler gear. 10. The image forming apparatus according to claim 6, wherein the spring clutch mechanism performs a half rotation control.