JPS6337389B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drum support device used in electrophotographic copying machines and the like.

Conventionally, a support device for a photoreceptor drum or a transfer drum, etc., which is provided with a charger or the like inside the drum, is provided with a support shaft passing through the drum.
A system is adopted in which the drum is pivotally supported on this support shaft. The drum support shaft is passed between two opposing side plates that are integrally constructed with an electrophotographic copying machine or the like, and is fixed to the side plates at both ends.

By the way, the following drawbacks have been pointed out in the drum support method as described above.

(1) It is difficult to attach and detach the drum (for example, the drum cannot be removed without disassembling the side plate).

(2) The positioning of the drum in the longitudinal direction of the shaft (so-called thrust direction) is not reliable.

(3) It is difficult to install chargers that must be installed inside the drum due to space issues (for example, the support shaft mentioned above gets in the way).

(4) When using a photosensitive drum and a transfer drum, one drum is brought into pressure contact with the other drum, but in this case, it is difficult to adopt a structure that ensures a follow-up contact operation with respect to the pressed drum.
This is because, for example, the configuration shown in FIG. 1 has to be adopted, and both ends of the transfer drum 101 in the longitudinal direction are pivotally supported by an integral support frame. As shown, the tension force of the spring 104 causes the support frame 102 to
oscillates, and the transfer drum 101 is transferred to the photoreceptor drum 1.
It is pressed against 00. In order to achieve uniform pressure contact with such a configuration, the cylindricity of the photoreceptor drum 100 and the transfer drum 101 must be precisely processed, and the shafts 100a, 101 must be precisely machined.
01a and 103 must be precisely assembled with respect to mutual parallelism.

However, the precision processing and assembly described above is limited in terms of man-hours and costs. Therefore, the pressure contact between the photoreceptor drum and the transfer drum is
Non-uniformity in the longitudinal direction of the axis causes so-called uneven transfer or transfer misalignment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a drum support device that can overcome the above-mentioned drawbacks.

This invention relates to a drum frame formed in a cylindrical shape, a rotating ring that is fitted into a cylinder at one end in the longitudinal direction of the drum frame and rotates integrally with the drum frame, and a rotating ring that rotates integrally with the drum frame. a permanent plate that rotatably supports the drum frame; a guide roller that rotatably supports the drum frame at at least three points on the circumferential surface of the other end in the longitudinal direction of the drum frame; A removable plate that is pivotally supported, and a stay that has one end fixed to either the permanent plate or the removable plate and is removably attached to the other plate that passes through the drum frame and leaves the other end. , characterized in that it has a pressing means that elastically presses the removable plate from the outside toward the permanent plate.

Hereinafter, one embodiment of the present invention will be described in detail.

In FIG. 2, reference numeral 105 indicates a photosensitive drum, and its shaft 105a is pivotally supported by a stationary member (not shown). This photosensitive drum 105
A gear 105g is formed integrally with the photosensitive drum 105 at the right end. This gear 105g
is meshed with a drive gear (not shown), and rotates in the direction of arrow P by power transmission from the drive gear. A photoreceptor is wound around the circumferential surface of the photoreceptor drum 105 . In this embodiment, the photoreceptor drum 105 is used as the drum to be pressed, and the transfer drum 106 is oscillated to press and separate the photoreceptor drum 105, which is set to be fixed (the position of the drum itself does not change). This will be explained based on an example where it can be used freely.

Referring to FIGS. 2 and 3, the transfer drum 10
6 is mainly composed of a drum frame body 106a having a shape in which a central part of a cylindrical body is cut out leaving a band shape in the axial direction, and a band-shaped remaining flesh part connecting the annular remaining flesh parts at both ends in the axial direction, A sheet gripper 107 for gripping the transfer paper is provided. This sheet gripper 107 is connected to the drum frame 1 through a shaft 107a.
It is pivoted to 06a. And this shaft 107a
One end is bent into an L shape, and the transfer drum 1
As the seat gripper 106 rotates, the L-shaped bent portion engages with a control cam (not shown) to open and close the seat gripper 107. Further, a dielectric film 108 is wrapped around the drum frame 106a so as to sufficiently cover the notch.

Referring to FIG. 3, a female socket 106a ₁ is formed inside the right end cylindrical portion of the drum frame 106a, and is fitted into the male socket of the rotating ring 110. Also, in this state, the drum frame 106
The convex portion 106a ₂ of a is the concave portion 110a of the rotating ring 110.
It is embedded in Thereby, the motion of the rotating ring 110 is reliably transmitted to the drum frame 106a.

On the outer periphery of the right end of the rotating ring 110, there is a gear 110g.
is formed and can mesh with the gear 105g. The pitch diameters of both gears and the outer diameters of the photosensitive drum 105 and the transfer drum 106 are all the same. In the rotating ring 110, a protrusion 110b having a trapezoidal cross section is formed on the inner side corresponding to the gear 110g.
It fits into the V-shaped groove of No. 11. The V-shaped groove is formed by two oppositely tapered thrust rollers 146 and 147 sandwiching a radial roller 145, and is further held by a spring plate ring 148, a spring receiver washer 149, a retaining ring 150, and the like.
The guide rollers 111 are pivotally supported by a shaft 111a embedded in the permanent plate 112, and at least two guide rollers (total of three or more) in addition to the one shown in FIG. 3 are similarly provided. In other words, the rotating ring 110 is rotatably supported on the permanent plate 112 by at least three or more guide rollers. Each guide roller above has 1 protrusion
It is assumed that they are arranged at equal intervals on the circumference inscribed in 10b. A cylindrical bearing holder 113 is inserted and fixed below the permanent plate 112. A fixed shaft 114 passes through the bearing holder 113 via a bearing. Further, the right end of the fixed shaft 114 is fixed to a side plate 125 of the main body of the electrophotographic apparatus, which is an immovable member. The left end of this fixed shaft is connected to the side plate 12.
It is fixed to a side plate 122 integral with 5 via an arm 123.

On the other hand, when paying attention to the left end of the drum frame 106a, a taper ring 115 is fixed there. The slope of the tapered portion 115a formed on the inside of the tapered ring 115 tapers so that the inner diameter increases toward the outside (to the left).
The tapered portions of at least three guide rollers 116 arranged at equal intervals on the circumference are in pressure contact with the tapered portion 115a, and the tapered ring 115 (transfer drum 106) is rotatably supported. There is. The guide roller 116 is pivotally supported by a shaft 116a implanted in the detachable plate 117, so that the guide roller 116 can be attached to the detachable plate 1 as described above.
17, the transfer drum 106 is rotatable. By the way, other 2 other than guide roller 116
The shafts on which the two guide rollers are supported are indicated by reference numerals 116b and 116c, respectively, in FIG.

Below the removable plate 117 is a spherical roller bearing 1.
24 is installed. The left end of the fixed shaft 114 is fitted into this spherical roller bearing 124, which allows a certain degree of redundancy in the mounting position of the detachable plate 117 in a plane perpendicular to the axis of the fixed shaft 114. Fixed shaft 1 passing through detachable plate 117
The shaft end of 14 is threaded and is prevented from coming off by a knob 126 screwed into this thread. This knob 126 is in the attached state.
It is located at a position slightly apart from the plate surface of the removable plate 117 to prevent interference when the removable plate 117 swings in a plane perpendicular to the axis of the fixed shaft 114.

Now, both of the plates 112 and 117 are pivotally supported at their lower parts by a fixed shaft 114, and at their upper parts, they have a stay 118 disposed so as to penetrate the inside of the transfer drum 106 in the longitudinal direction. It is also stopped even if it is done through. For example, the right end of the stay 118 is attached to the permanent plate 112 with two screws 119.
a, 119b, and the stay 11
The left end of 8 is fixed to the detachable plate 117 by a reference pin 119 embedded in the stay 118. Specifically, the tip of the reference pin 119 protrudes through the detachable plate 117 at the center of gravity of the triangle connecting the shafts 116a, 116b, and 116c, and is fitted with an extensible spring 120. This spring 120 is then pressed by a locking knob 121 that is fitted and locked onto the reference pin 119.
It is in a compressed state. For example, during assembly, the removable plate 117 is pushed to the right by the elasticity of the spring 120 while being supported by the load on the fixed shaft 114 that passes through the spherical roller bearing 124, and the female pilot part 106a ₁ is pushed to the right of the rotating ring 110. After being abutted against the flange, the tapered surfaces of the three guide rollers including the guide roller 116 are held in a state in which they are evenly pressed against the tapered surface of the tapered ring 115.

A mechanism for locking the locking knob 121 in a predetermined position on the reference pin 119 is shown in FIG. That is, the reference pin 119 has a groove 127 formed in the direction perpendicular to its circumferential axis, and the stop knob 1
A groove 128 is also formed in 21, and this groove 12
When the half-moon-shaped plate 129 sliding inside the groove 8 is present in both grooves 127 and 128, the stop knob 121 is locked at that position. Reference numeral 130 indicates a ring-shaped spring;
By being wrapped around the outer periphery of the stopper knob 121, the plate 129 is held in the groove 128 and a force is applied to force the plate 129 to fall into the groove 127. Reference pin 11 in the above
9, a spring 120, a stopper knob 121, etc., is referred to as a pressing means. This pressing means functions to elastically press the removable plate 117 from the outside toward the receiving plate.

Next, the shape of the hole in the detachable plate 117 through which the reference pin 119 passes is formed into a chevron shape so that the area of the inner peripheral surface of the hole is minimized, as shown in the cross section of FIG. And with this shape,
The reference pin 119 is supported by the detachable plate 117 in a state similar to a line contact.

This configuration and the configuration in which the removable plate 117 is pressed by the spring 120 are such that the removable plate 11
7 is pivotally supported by the fixed shaft 114 via the spherical roller bearing 124, and the removable plate 1
Even in the attached state of 17, the removable plate 1
Allow 17 to do the next exercise. This movement is a movement of swinging the detachable plate 117 in a plane perpendicular to the axis of the fixed shaft 114. Of course, this amount of momentum (amount of displacement) is not that large. The amount of displacement necessary for the transfer drum 106 to evenly press against the photosensitive drum 105 in the axial longitudinal direction is as follows:
This is because it is usually not that large. That is,
The plates 112 and 117 are each independently rotatable around the fixed shaft 114 within the above range of momentum. Note that here, there is a concern about changes in the pressure contact status of the guide roller 111 section, the guide roller 116 section, etc., but the structure of these sections is similar to a spherical roller bearing, and the transfer drum 106 can rotate smoothly. I can do it.

Next, a description will be given of a pressing means for elastically pressing the transfer drum 106 supported by the plates 112 and 117 against the photosensitive drum 105 as a drum to be pressed. One set of pressure contact means having the same configuration is provided for each of the permanent plate 112 section and the removable plate 117 section. In addition,
A set of press-contact means in the detachable plate 117 part, whose entire structure is shown in relation to the illustrations, will be explained with reference to FIG. 2.

A pin 1 is provided near the lower end of the removable plate 117.
31 is planted facing inward, and this pin 131
is fitted into a notch 133 made in the slide fitting 132. The slide fitting 132 is attached to the fixed shaft 114
in a direction perpendicular to the axis of the photosensitive drum 105
The end portion is bent into a U-shape, and the back surface of the U-shaped portion is set to slide into contact with the inside of the side plate 122. There is a side plate 122 on the back side of this U-shaped part.
A screw 135 is screwed in from the outside through the long notch 134, and the slide fitting 132 is inserted into the long notch 134.
can be moved in the direction of arrow Q within the range of . A compressible spring 135 is placed between the end bent piece 132a of the slide fitting 132 and a stationary member (not shown), and acts to constantly attract the slide fitting 132. Therefore, the pin 131 is also pulled through the hole 133, and the removable plate 117 is rotated counterclockwise about the fixed shaft 114, and the transfer drum 106 is brought into pressure contact with the photoreceptor drum 105. . And it stopped in that state. Now, the other end of the slide fitting 132 is formed into a ring shape, and this ring 1
A cylinder 139 passes through 36. An eccentric shaft 137 extending in the axial direction from a position offset from the cylinder axis of the cylinder 139 is pivotally supported by a stationary member (not shown). Note that this cylinder 139 passes through a component corresponding to the ring 136 provided on the side of the permanent plate 112. A lever 138 is fixed to the shaft end of the eccentric shaft 137, and if this lever 138 is manually rotated,
The cylinder 139 rotates eccentrically and is inscribed in the ring 136, and finally the slide fitting 132 is moved by the spring 135.
can be moved in the direction of arrow Q against the tightening force of. In this manner, by rotating the lever 138, the transfer drum 106 is moved to the photosensitive drum 1.
When separating from 05, plate 117,
112 can be rotated at the same time, and eventually the transfer drum 10
6 can be simultaneously spaced apart from the photoreceptor drum 105 by the same amount in the longitudinal direction. Further, when bringing the transfer drum 106 into pressure contact with the photoreceptor 105, the lever 138 is rotated in the opposite direction to that described above. Then, due to the eccentric movement of the cylinder 139,
Since the engagement between the ring 136 and the cylinder 139 is released and there is nothing to restrict the movement of the slide fitting 132, the tension force of the spring 135 will directly act on each plate, and the transfer drum 106 will be centered around the fixed shaft 114. Both end portions in the longitudinal direction of the shaft are swung independently, and are closely pressed against the photosensitive drum 105 in the longitudinal direction. In this state, gear 10
5g and the gear 110g are in mesh with each other, and the transfer drum 106 moves toward the photosensitive drum 10 in the direction of the arrow P'.
It will be rotated at the same circumferential speed as 5.

In this way, the transfer drum 106 is brought into uniform pressure contact with the photosensitive drum 105, so that a good copy without uneven transfer can be obtained. Further, by operating the lever 138, the photosensitive drum 105 and the transfer drum 106 can be easily separated from each other, which is convenient for various maintenance such as replacing the dielectric film 108.

As described above, the spring 135 and the slide fitting 1
32, pin 131, cylinder 139, lever 138, etc. are the main members of the pressure contact means according to the present invention.

Now, when maintenance is required such that the amount of separation between the photoreceptor drum 105 and the transfer drum 106 due to the rotation of the lever 138 is not sufficient, for example, when replacing the transfer drum, the transfer drum 106
6 needs to be disassembled. Even in that case,
The arrangement according to the invention is convenient. In the disassembly procedure, first turn the stop knob 121 by half a turn. Then, the plate 129 is pushed by the outer periphery of the reference pin 119 and comes out of the groove 127, so that the plate 129 can then be pulled out from the reference pin 119 together with the spring 120. Next, by removing the knob 126, the detachable plate 117 can be removed outward. Thereafter, the transfer drum 106 can also be removed outwardly. Note that the assembly may be performed in the reverse order of the above steps. However, it should be noted that when the convex portion 106a ₂ is fitted into the concave portion 110a and the spigot portion of the rotating ring 110 is
This is the point at which the female socket part _106a1 of the drum frame body 106a is inserted.

Next, in this embodiment, the rotating transfer drum 1
Various chargers can be attached to the stay 118, which is immovable relative to the 06. This is because the charger satisfies the condition that it must remain stationary relative to the rotating transfer drum. For example, in FIG. 2, reference numeral 140 indicates a transfer charger, which is located inside the transfer drum 106 and is connected to the photoreceptor drum 1.
It is fixedly arranged opposite to the pressure contact part with 05.
This transfer charger 140 is fitted from the outside of the detachable plate 117 along a guide portion 141 formed on a side piece of the stay 118.
The transfer drum 106 is pushed in a certain direction by leaf springs 142 and 143, and the distance between the dielectric film 108 and the transfer drum 106 is
are positioned equally over the longitudinal direction of the axis (see FIGS. 3 and 6). Incidentally, reference numeral 143 indicates a plug for conducting electricity, and it is constructed integrally with the transfer charger 140. The plug 143 is in contact with a jack 144 provided on the rocking plate 112, and is configured to receive electric power. The transfer charger 140 can be easily taken out from inside the transfer drum 106 as needed.

The stay 118 has the transfer charger 14
In addition to 0, a necessary charger can be provided as appropriate. The separation charger 145 shown in FIG. 2 and the pre-charger 146 shown in FIG. ing. For example, the 6th
In the figure, a separation charger 145 is provided at a branch portion 118a from the stay 118;
A precharger 146 is attached to b.

As described above, in the present invention, since the detachable plate 117 is simply stopped by the locking knob 121 that can be attached and detached with one touch and the knob 126 that can be easily removed without using any tools, it is easy to remove the detachable plate 117. can be easily removed. Needless to say, assembly can be easily performed by reversing the procedure. Further, in the present invention, the drum (transfer drum 106 in the embodiment) is pressed by the pressing means.
Since the drum is configured to be elastically pressed in the longitudinal direction of the shaft, the positioning of the drum in the longitudinal direction of the shaft is also reliably performed.

Further, in the present invention, a charger or the like can be attached to the stay 118 using the stay 118.

Moreover, the permanent plate 112 and the removable plate 11
Since the drums 7 can be rotated independently, follow-up contact operation can be performed reliably even when the drum is brought into pressure contact with another drum.

Finally, as an example of an electrophotographic copying machine suitable for carrying out the present invention, a color copying machine that the present inventors intend to newly provide will be described.

In FIG. 7, the reference numeral 1 at the top indicates a document placement glass. Reference numeral 2 at the lower right end of the document placement glass 1 indicates an illumination lamp, and reference numeral 3 near it indicates a mirror. Reference numerals 4 and 6 at the lower left side of the document placement glass 1 also indicate mirrors, and reference numeral 5 at the lower center of the document placement glass 1 indicates an in-mirror lens. Reference numbers 7 and 8 on the lower and right sides of this in-mirror lens 5 both indicate mirrors, and reference number 9 between mirrors 6 and 7.
indicates a filter member.

Reference numeral 10 in the center of the drawing indicates a photoreceptor, and reference numeral 11 above the mirror 8 indicates a light shielding plate. Reference numeral 12 above the photoreceptor 10 indicates a charger, and hereinafter, reference numerals 13, 14, 15, 16, 17, 1 arranged counterclockwise around the photoreceptor 10 are used.
Reference numerals 8 and 19 respectively indicate an erase lamp, a developing device, a developing device, a developing device, a transfer drum, a cleaning device, and a static elimination charger.

Reference numeral 20 at the bottom right of the figure is a cassette, reference numeral S to the right is a transfer paper, and reference numeral 21 above it is a delivery roller. Reference numeral 22 on the left side of the cassette 20 indicates a guide, reference numeral 23 on the left thereof indicates a registration roller, and reference numeral 24 on the left thereof indicates an ironing roller.

Reference numbers 25, 26, 27 inside the transfer drum 17
show a precharger, a transfer charger, and a separation charger, respectively, and the precharger 25 and separation charger 27 that are located inside the transfer drum 17 form a pair. The reference numeral 28 between the separation charger 27 and the precharger 25 indicates a separation claw, and the reference numeral 29 above the guide 22 indicates a cleaning device. or,
Reference numeral 30 on the right side of the separation claw 28 is a guide, and reference numeral 31 is a guide.
3 indicates a fixing device, and 32 indicates a discharge roller.

The illumination lamp 2, mirrors 3 and 4, in-mirror lens 5, and mirrors 6, 7, and 8 constitute an exposure optical system.

The in-mirror lens 5 and mirrors 6, 7, and 8 are fixed, but the illumination lamp 2 and mirrors 3 and 4 are movable. That is, when copying, the illumination lamp 2,
The mirrors 3 move together in the direction of the arrow to slit-scan the original O on the original placing glass 1.
At this time, the mirror 4 moves in the direction of the arrow at half the moving speed of the mirror 2, keeping the optical path length from the scanned part of the document O to the in-mirror lens 5 unchanged.

The light shielding plate 11 swings around the axis 11A as necessary to adjust the amount of light exposed to the photoreceptor.

The filter member 9 has three types of filters, namely, blue filters F/B, green filters F/G, and red filters F/R, isotropically and integrally arranged around a rotational axis 9A perpendicular to the drawing as an axis of rotational symmetry. It can be rotated in the direction of the arrow, and by rotating it, any one filter can be placed in the exposure optical path.

The photoreceptor 10 is formed into a drum shape, its peripheral surface serving as a photoreceptor surface, and is rotatable in the direction of the arrow.

The developing devices 14, 15, 16 are identical to each other with respect to their function; they differ essentially only with respect to the color of the toner in the developer used in each. Now, the structure and functions of the developing device 14 using yellow toner will be explained by taking as an example.

The developing device 14 includes an outer surrounding member 14A, a developing roller 14B, scooping rollers 14C and 14D, a separator 14E, a doctor 14F, and a stirring tool 14G.
The main part is made up of. Photoreceptor 1
The developing roller 14B disposed close to the
Magnets 14B1, 14 held on support body 14B3
B2 and a sleeve 14B4. The magnets 14B1 and 14B2 have a prismatic shape that is elongated in a direction perpendicular to the drawing, are magnetized in a direction perpendicular to the longitudinal direction, and have a pair of side surfaces serving as magnetic pole faces. The magnet 14B1 is held by the support 14B3 with one of its magnetic pole faces facing the circumferential surface of the photoreceptor 10 in the length direction.
B2 is held with one of its magnetic pole faces facing downward. The magnets 14B1 and 14B2 are held fixedly in the copying device space. Note that the support body 14B3 is a nonmagnetic material. The sleeve 14B4 is made of a non-magnetic material, is provided to surround the magnets 14B1 and 14B2, and is rotatable in a counterclockwise direction.

Lifting rollers 14C and 14D disposed below the developing roller 14B are structurally the same as the developing roller 14B. Both sleeves are rotatable counterclockwise.

The stirring tool 14G disposed near the bottom of the surrounding member 14A has a twisted blade shape and rotates counterclockwise to stir the developers G and Y at the bottom of the surrounding member. The developers G and Y are a mixture of a magnetic powder carrier and a powder yellow toner, and are charged to opposite polarities by stirring by the stirring tool 14G. This causes the carrier and toner to electrically adhere to each other.

The developers G and Y are first held on the circumferential surface of the scooping roller 14D by the magnetic force of the magnet inside the roller, and are conveyed by rotation of the sleeve and sent to the scooping roller 14C. Similarly, the pumping roller 14C transfers the developer G and Y received from the pumping roller 14D to the developing roller 14B.
The developing roller 14B conveys the developers G and Y to the developing section by rotation of the sleeve 14B4, and the conveyed developers are subjected to development. Note that the amount of developer conveyed to the developing section is regulated by the doctor 14F. Further, the developers G and Y become brush-like in the developing section due to the action of the magnetic field of the magnet 14B1.

The developer that has contributed to the development moves with the rotation of the sleeve 14B4, escapes the area of influence of the magnet 14B1, is separated from the circumferential surface of the sleeve 14B4 by the separator 14E, and is transferred to the surrounding member 14A again.
is collected at the bottom of the

The above is the configuration and function of the developing device. In addition,
In the developing device 15, a mixed system of carrier and magenta toner is used as developer G.M,
In the developing device 16, a mixed system of carrier and cyan toner is used as developer G/C.

The transfer drum 17 is a hollow drum-shaped frame whose peripheral surface is covered with a highly insulating film, and is rotatable in the direction of the arrow, that is, in the clockwise direction. A clamper is arranged on a part of the circumferential surface in a direction parallel to the axis.

Now, below, the operation of each part of the above apparatus will be explained in accordance with an actual color copying process.

When a color original O to be copied is placed on the original placing glass 1 and the apparatus is operated, the photoreceptor 10 rotates counterclockwise and the charger 12 discharges.
The circumferential surface of the photoreceptor is uniformly charged. The erase lamp 13 emits light as necessary to eliminate static electricity in the non-image forming area.

During this time, the illumination lamp 2 emits light, and the uniformly charged peripheral surface of the photoreceptor reaches the exposure section, and at the same time moves to the left together with the mirror 3 to scan the document O through the slit. At this time, mirror 4 is 1/2 of mirror 3.
move at a speed of The moving speed of the mirror 3 is equal to the peripheral speed of the photoreceptor 10 if the copying magnification is the same. Thus, the photoreceptor 10 is exposed to light. At this time, since the blue filters F and B of the slit member 9 are installed in the exposure optical path, the original image is color-separated. Since the blue filter F/B has an optical property of transmitting blue light, yellow light, which is a complementary color to blue, is absorbed. That is, photoreceptor 1
0 is exposed to light from which the yellow component has been removed during the exposure, and in this way an electrostatic latent image corresponding to the yellow component image on the original O is formed.

This electrostatic latent image is made visible by the developing device 14, and a yellow visible image is formed on the photoreceptor 10.
This visible image moves as the photoreceptor 10 rotates. Note that while the developing device 14 is operating, the developing devices 15 and 16 are not operating.

Now, the transfer paper S is sent out from the cassette 20 by the delivery roller 21 at an appropriate time, and sent to the registration roller 23 through the guide 22. When the registration roller 23 grips the leading edge of the transfer paper 5, it waits in preparation for the clamp timing.

Meanwhile, the transfer drum 17 has started rotating clockwise together with the photoreceptor 10. At the same time, the separation charger 27 discharges electricity inside and outside the transfer drum to eliminate static electricity from the transfer drum. Next, the peripheral surface of the transfer drum, which has been neutralized in this way, is precharged by a pair of prechargers 25 inside and outside the drum. Its polarity is determined so that the outer peripheral surface of the transfer drum 17 has the opposite polarity to the toner image (yellow visible image) on the photoreceptor 10, that is, the same polarity as the electrostatic latent image. .

The transfer drum 17 precharged in this way
The transfer paper S is moved around the circumferential surface of the registration roller 23 in synchronization with the movement of the yellow visible image on the photoreceptor 10.
The paper is fed by Then, the leading end of the transfer paper S is clamped by a clamper (not shown), and then moves while being stuck to the circumferential surface of the transfer drum 17.

The squeezing roller 24 acts so that the transfer paper S comes into close contact with the circumferential surface of the transfer drum 17 without wrinkles or the like. Note that the reference numeral 24A is a corresponding roller for supporting the contact pressure of the squeezing roller 24 against the transfer drum 17.

Transfer paper S held on the peripheral surface of the transfer drum 17
is superimposed on the yellow visible image on the photoreceptor 10 at the contact portion between the photoreceptor 10 and the transfer drum 17 . At the same time, the transfer charger 26 sets the transfer drum 17 at a higher potential by discharging with the same polarity as the electrostatic latent image, so that the visible image is transferred to the transfer paper S.
electrostatically transferred onto the surface. After visible image transfer, transfer paper S
continues to rotate together with the transfer drum, but at this time, the separation charger 27 and the precharger 25 have stopped discharging, and the cleaner 29 has also stopped its function. On the other hand, the photoreceptor 10 after the yellow visible image transfer is rotated and reaches the cleaning section of the cleaning device 18, and the brush 18A and blade 18B rotate counterclockwise.
As a result, residual toner is removed, and then the static electricity is removed by the static eliminating charger 19, and then immediately charged by the charger 12 in preparation for new use.

Now, after performing the slit scanning, the exposure optical system has returned to the starting position, and at the end of the slit scanning, the filter member 9 also moves counterclockwise.
Rotates 120 degrees.

At the same time as the newly charged part reaches the exposure section, a new slit scan of the original O is started, but this time, green filters F and G are installed in the exposure optical path, so the color is complementary to green. An electrostatic latent image is formed corresponding to a certain magenta component image. This electrostatic latent image is visualized by the developing device 15 to form a magenta visible image. At this time, the developing devices 14 and 16 are stopped in operation.

The magenta visible image thus obtained is electrostatically transferred onto the transfer paper S held by the transfer drum 17 by the transfer charger 26 so as to be superimposed on the yellow visible image. At this time, in order to increase transfer efficiency,
The discharge voltage of the transfer charger 26 is slightly increased.

The same process as before is repeated with the red filter F/R installed in the exposure optical path, and when an electrostatic latent image corresponding to the cyan component image is formed on the photoreceptor 10, this electrostatic The latent image is made visible by the developing device 16. At this time, the developing device 14,
15 does not operate. When the obtained cyan visible image is transferred onto the transfer paper, the yellow visible image, magenta visible image, and cyan visible image overlap each other on the transfer paper S, and the color visible image for the original O is here. It is formed. During the transfer of the cyan visible image, the discharge voltage of the transfer charger 26 is also slightly increased.

The transfer paper having the color visible image is then subjected to charge removal by the separation charger 27, and when it passes the charger, the clamp at the leading end is released. In this state, the separation claw 28 acts to separate the transfer paper S from the peripheral surface of the transfer drum 17. As the transfer drum 17 rotates, the separated transfer paper S is guided by a guide 30 and advances to the fixing section, where the color visible image is fixed by the fixing device 31, and then sent out of the device by the ejection roller 32. It is discharged.

The fixing device 31 heats and presses the color visible image on the transfer paper using a heat roller 31A and a pressure roller 31B to fix it on the transfer paper. A mold release liquid is supplied by an oil supply mechanism 31C, and the peripheral surface is cleaned by a cleaning roller 31D.

A cleaning device 29 cleans the peripheral surface of the transfer drum 17 after the transfer paper has been separated.
Note that the reference numeral 29B indicates a counter-pressure roller for the cleaning blade.

On the other hand, the photoreceptor 10 after the cyan visible image has been transferred is further rotated to undergo cleaning and charge removal.

The exposure optical system returns to the starting position, and the filter member 9 further rotates 120 degrees, reproducing the state shown in FIG. 7.

The color copying process is thus completed.

The above is an overview of the color copying process.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main part of a drum pressure welding device according to the prior art, Fig. 2 is a perspective view showing an embodiment of the present invention, Fig. 3 is a sectional view of the same figure, and Fig. 4 is a sectional view of the stopper knob. Figure 5 is a sectional view of the reference pin penetration point in the rocking plate, and Figure 6 is the Y--
The Y cross-sectional view and FIG. 7 are front views of essential parts showing an example of a color copying machine. 106a...Drum frame body, 110...Rotating ring,
112... Permanent plate, 116... Guide roller, 117... Detachable plate, 118... Stay, 119... Reference pin as pressing means, 12
0... Spring as pressing means, 121... Stop knob as pressing means, 131... Pin as pressing means, 132... Slide fitting as pressing means, 135... Spring as pressing means, 138
... Lever as pressure contact means, 139 ... Cylinder as pressure contact means, 140 ... Transfer charger,
145...separation charger, 146...precharger.

Claims (1)

[Scope of Claims] 1. In a support device for a photosensitive drum or a transfer drum, etc., which is provided with a charger or the like inside the drum, there is provided the following: a drum frame formed in a cylindrical shape; A rotating ring that is fitted into the cylinder at one end and rotates integrally with the drum frame, a permanent plate that rotatably supports this rotating ring, and a periphery at the other end in the longitudinal direction of the drum frame. A guide roller that rotatably supports the drum frame at at least three points on the surface, a removable plate that pivotally supports the guide roller, and one end fixed to either the permanent plate or the removable plate. It has a stay that penetrates through the drum frame body and is detachably attached to another plate with the other end remaining, and a pressing means that elastically presses the detachable plate from the outside toward the permanent plate. A drum support device featuring: 2. A fixed shaft that is provided integrally with the immovable member and pivotally supports the removable plate and the permanent plate; 2. The drum support device according to claim 1, further comprising pressure contact means for elastically pressing the drum that is in contact with the drum to be pressed against the drum. 3. The drum support device according to claim 1, wherein a charger or the like is attached to the stay.