JPS6285276A - Image forming device - Google Patents

Abstract

PURPOSE:To perform multicolor changeover copying operation by revolving two developing devices in a parallel state and setting one developing device at a development position by a revolving unit, and making an image formation process speed faster when the 2nd developing device is set at the development position than when the 1st developing device is set. CONSTITUTION:At least one set of the 1st developing device 27c composed of a single developing device part and at least one set of the 2nd developing device 27d consisting of at least two developing device parts in one body are revolved while held in the parallel state and one developing device is selected by the revolving unit. A contacting/separating means is provided which allows the developing device selected by the revolving unit 28 to contact or leave an image carrier 12 and the image formation process speed is made faster when the 2nd developing device 27d is set at the development position nearby the carrier 12 than when the 1st developing device 27c is set.

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to an image forming apparatus, such as a copying machine, which can perform multicolor copying. [Technical background of the invention and its problems 1 In recent years, a high-speed image forming apparatus that requires time for development has been developed (Japanese Patent Application Laid-Open No. 57-661). Since it is necessary to simultaneously perform development at the same time, there is not enough space around the photoreceptor drum to accommodate the pond-colored developing device, making it impossible to perform multicolor automatic switching and copying. [Object of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to achieve high-speed copying and multi-color switching copying in one
1. V? It is about providing. [Summary of the Invention J In order to achieve the above object, the present invention provides an image forming apparatus that develops a latent image on an image carrier. At least one first developing device consisting of a container part and a second developing device having at least two or more developing device parts integrated are each provided, and these first developing device I3 and second developing device are shown in FIG. ■The developing device 1@ is selected by rotating it while keeping it in a parallel state at a position apart from the image carrier, and the selected developing device is brought close to the image carrier to perform the development. , an image forming process speed when the second developing device is set is faster than an image forming process speed when the first developing device is set at a developing position close to the image carrier; This is considered special mold. [Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 17 and FIG. 1 show a multicolor copying machine as an image forming apparatus according to the present invention, and numeral 1 in these figures is the main body of the copying machine. An original platen 2 is fixed on the top surface of the main body 1 to place an original.
．． By reciprocating the optical system consisting of 6 along the lower surface of the document table 2, exposure scanning is performed during the forward movement. In this case, the mirrors 5 and 6 are moved at 4/2 the speed of the mirror 4 so as to keep the optical path length constant. The light reflected from the original by the scanning of the above-mentioned optical system, that is, the light reflected from the original by the light irradiation of the exposure lamp 3, is reflected by the mirrors 4 and 5.6, and then is reflected by the copying magnification setting lens. Pass through block 7 and continue with mirrors 8, 9.
10 and is guided to a photoreceptor drum 12 as an image carrier via a sleeve 1-11, so that an image of the document is formed on the surface of the photoreceptor drum 12. The photosensitive drum 12 rotates in a predetermined direction, and its surface is first charged by a charging device 13, and then an image of the original is exposed to light from the sleeve 1 to form an electrostatic latent image. The image is configured to be developed by applying toner to the image by a developing device 14, which will be described in detail later. On the other hand, the paper p is taken out one by one from the paper feed cassette 15 by the paper feed mirror 16, guided through the #A guide path 17 to a pair of registration rollers 18.18, and aligned by the registration rollers 18.1B. The image transfer section is configured such that the image is transferred to the image transfer section. The paper feed cassette 15 is freely disposed at the lower right end of the main body 1. Thus, the paper p sent to the image transfer section comes into close contact with the surface of the photoreceptor drum 12 at the transfer charger 19.
By the action of the charger 19, one henna image on the photoreceptor drum 12 is transferred. The paper p to which this toner image has been transferred is
By the action of the peeling charger 20, the mushrooms are electrostatically peeled off from the photosensitive drum 12, transported W1 by the conveyor belt 21, and sent to the fixed @ mushroom 22 provided at the end of the belt. The transferred image is fixed. Then, paper p after fixing
1-ray 2 outside the main body 1 by the paper ejection rollers 23 and 23.
It is configured to be discharged at 4. Further, the photosensitive drum 12 after the transfer is configured so that residual toner on the surface thereof is removed by a cleaner 25, and then the afterimage is erased by a static elimination lamp 26, so that the image returns to the initial state. The developing device 14 includes three first developing devices 27a to 27C for normal speed copying in which the developing device section 100 is idle, and two developing device sections 100 and 100 for high-speed copying. Each of these developing devices 27a to 27d is connected to the revolving unit 1 by 28.
By rotating the developing devices 27a to 27d while maintaining a parallel state (horizontal state), one of the developing devices 27a to 27d can be selected. Further, this developing device 14 has a contact/separation mechanism 2.
9, it is movable in the left and right directions (in the direction of approaching and separating from the photoreceptor drum 12). In other words, during copying operation,
As shown in FIG. 1, the selected developing devices 27a to 27d
is set facing the photoreceptor drum 12 g! ,
(in close proximity to the photoreceptor drum 12), and the developing device 2
When selecting one of the developing units 7a to 27d, as shown in FIG. 2, the developer is moved to a position a predetermined distance away from the photosensitive drum 12, and at this position, the selection operation of the developing units 27a to 27d is performed. When this selection operation is completed, the developing units 27a to 27d are moved to the photosensitive drum 12 side again, and the selected developing devices 27a to 27d are set opposite to the photosensitive drum 12, as shown in FIG. Become. Next, the developing device 14 will be explained in detail. As shown in FIG. 3, the main body frame 30 has a support shaft 31.
A pair of hanging members 32a and 32b are suspended through a shaft 31 so as to be able to swing.
28 is supported.・That is, as shown in FIGS. 3 and 4, a shaft 1T frame 1-33 is rotatably installed between the suspension members 32a and 32b, and the suspension portion t432a of this shaft 33
, 32b is provided with a front rotating frame 34a.
Jff and the rear rotating frame 34b are fixedly provided, and an auxiliary frame 35 is provided roughly between the front rotating frame 34a and the suspension member 32a. Furthermore, rotating shafts 36a to 36 (j) are rotatably disposed between the front rotating frame 34i and the auxiliary frame 35 via bearings (see FIG. 7), and these rotations N36a to 36
6d, the rear rotating frame 34b has a receiving part 3.
7a to 37d are arranged. The rotating shafts 368 to 36d and the receivers 378 to 37d are connected to the front side coupling part 38a and the rear side coupling part 381) 8, respectively, to the developing device 27a. ~
27d is configured as rR. Then, the three-selection motor 39 with βj fixed to the electric quantity member 32a drives the pulley 40, the timing belt 41. The above-mentioned Freon 1-side rotating frame 3 is
The developing devices 27a to 27d revolve around the shaft 33 by rotationally driving the rear rotating frame 34a and the rear rotating frame 34b. Further, a holding mechanism 43 is provided between the rotating frame 34a and the auxiliary frame 35 to hold the rotating shafts 36a to 36d so that the developing devices 27a to 27d are oriented in a fixed direction. That is, a sun pulley (fixed pulley) 44 is fitted between the front rotating frame 34a of the shaft 33 and the auxiliary frame 35, and is fixed to the suspension member 32a. Although it is rotatable relative to the shaft 33, it is fixed relative to the main body 1 side. That is, even if the front side rotating frame 34a, the rear side rotating frame 34b8, and the auxiliary frame 35 rotate, the sun pulley 44 does not rotate. In addition, the front side frame 3 of the rotation shafts 368 to 36d
4a and the auxiliary frame 35, planetary pulleys (revolving pulleys) 458 to 45 (l) are fixed respectively. Also, a timing belt 4G is connected between the sun pulley 44 and the planetary pulleys 45a and 45b, and a timing belt 4G is connected to the sun pulley 44. B and f
Timing belt 47 between f1l bushes 45c and 45d
are each recorded as an ear wave. However, solar pulley 4
4 and each 'fi star pulley 45a and -45d have the same outer diameter, and when the front side rotating frame 34a and the rear side rotating frame 34b rotate, the planetary pulleys 45a to 45d revolve without rotating. . Therefore, the developing units 27a to 27d always revolve at the same angle, that is, while maintaining a parallel state. This is a necessary operation because the developing units 27a to 27d contain hners that serve as the main body. Here, for example, the developing device 27a has a red color, the developing device 27b has a blue i-color, and the developing device 27b has a blue i-color. It is assumed that the developing device 27C stores green developing device 1, and the developing device 27d stores black developing devices 1 to 1, respectively. As shown in FIG. 5, the rear side coupling portion 38b has a structure in which four bearings that fit into shafts 48 protruding from the rear side of the developing devices 27a to 27d are biased toward the front side by a spring 50. It has become. In addition, spring 5
0 is attached to the rear rotating frame 34 [) by the holder 51.
The receivers are fixed to the parts 37a to 37d. The front side coupling portion 38a is as shown in FIGS. 6 and 7. Sunara, the above rotating wheel 3
A boulder 52 is fixed to each of 68 to 36d, and this boulder 52 has a groove portion that slidably and rotatably supports the shaft 53 protruding from the freons 1 to 1111 of the developer '1A27a to 27 (j). Further, this boulder 52 is provided with a groove 56 having a recess 55, and a lever 59 having a locking pin 584 biased by a spring 57 is rotatably attached to this vortex 56. By fitting the locking pieces 58 into the recesses 55, the angle of the lever 59 is held at three levels. is connected to a cam 61 via a shaft 60, and this cam 61 has a shape with a large diameter portion 61a that presses the shaft 53 toward the rear side. A rear stop portion 61b and a rotation stop portion 61c are provided which fit into the provided groove 538 and milling cut portion 53b to prevent the shaft 53 from closing and rotating. To do this, first, the rear shafts 48 of the developing devices 27a to 27d are blown into the bearings 4-9 of the rear coupling portion 38b, and in this state, while pressing the developing devices 27a to 27d toward the rear side, the developing devices 27a to 27d are rotated. Place the shaft 53 on the front side 1- side of 27d on the U-groove portion 54 of the front side coupling portion 38a.At this time, the lever 5 is in the state shown in FIG. From this state, the five levers are brought into the state shown in FIG. : Performs abutment and axial positioning. In this state, the developing units 27a to 27d are in a state where they can rotate about the rotating shafts 36a to 36d, and therefore, when changing the angle of the developing units 27a to 27d, it is only necessary to set five levers to this state. Next, the lever 59 is further lowered to the state shown in FIG. prevents it from slipping out and rotating. Since the holder 52 is fixed to the rotating wheels 368 to 36d, the developing devices 27a to 27 in the state shown in FIG.
This means that the installation of d has been completed. The revolving unit 28 suspended by the suspension members 32a and 32b is in contact with each other as shown in FIGS.
The photoreceptor drum 12 is brought into contact with and separated from the photoreceptor drum 12 by a machine 162. That is, the suspension members 32a, 32
b(7) Arms 63a, 63 are provided near the lower end of each
b is arranged to be approximately perpendicular to the suspension members 32a, 32b. On the opposite side of the arms 63a and 63b from the photoreceptor drum 12, an elongated hole 64 that extends toward and away from the photoreceptor drum 12 is formed, and a bushing 65 is rotatably and removably attached to this elongate hole 64. It is being Further, this bushing 65 is urged toward the photosensitive drum 12 by a spring 6G. Further, a connecting pin 67 fixed to the suspension members 32a and 32b is rotatably fitted into the hole of the bush 65. Also, the photosensitive drums 12 [1111 of the arms 63a and 63b]
A bearing 68 is fitted in the 7-rank Ui lateral portion 72, which is made up of a pin 69, a link 70, and a shaft 71, and is connected via this bearing 68. Further, the shirts 1 to 71 are rotatably held by the main body frame 30, and this shaft 71 has a pulley 73,
Motor 7 via timing bell l-74 and pulley 75
Torque from 6 is transmitted. The rotation of the motor 76 causes the revolution unit 28 to move toward and away from the photosensitive drum 12 . As shown in FIG. 11(a), when the revolving unit 28 is at the developing position close to the photosensitive drum 12, the center of gravity of the revolving unit 28 is approximately below the support shaft 31. The structure is as follows. That is, the line connecting the support shaft 31 and the shaft 33 is approximately perpendicular, in other words, the revolving unit 1-2
The vector of gravity applied to the shaft 8 is located at a position passing through the support shaft 31. Also, at this time, the bushing 65 is pressed toward the photosensitive drum 12 by the spring 66 without touching either end of the elongated hole 64, and the selected yA image vaporizers 27a to 27d are A portion of each of the developing devices 27a to 27d abuts against a positioning portion (not shown) provided on the main body frame 30, so that the distance from the photosensitive drum 12 is maintained constant. Further, in this state, the motor 76 is rotating so that the bin 69 faces most towards the photosensitive drum 12 side. Furthermore, when the motor 76 starts rotating from this state,
The left end of the elongated hole 64 is in contact with the bushing G5, and the revolution unit 2
8 begins to separate from the photoreceptor drum 12. Then, when the motor 76 rotates further. The suspension members 32a and 32b are tilted so that the revolution unit 28 is separated from the photosensitive drum 12 and is in a position where it can revolve, as shown in FIG. 11(b). The first developing devices 27a to 27c are constituted by a single developing device section 100, as shown in FIG. That is, the developer case 81 contains developer G, which is a mixture of toner T and magnetic carrier C in an appropriate ratio. This developer G is conveyed by a magnet 1-roller 82 containing a built-in magnet, and is transferred to a doctor blade 8.
3, the photosensitive drum 1 is regulated to a predetermined layer thickness S.
The electrostatic latent image previously formed on the photoreceptor drum 2 is thereby developed. Further, 84 is a stirrer, which mixes and stirs the toner T, which is replenished when the toner concentration in the developer G decreases, and the developer G, and maintains the toner concentration in the ring developer G uniformly. It is. A toner hopper part 85 storing toner T to be replenished is provided at the upper part of the developing device case 81, and this (-
The toner bopper portion 85 supplies toner T onto the agitator 84 in the developing device case 81 through the l-toner replenishing port 87 as the toner replenishing roller 8G rotates. On the Freon L- side of the first developing units 27a to 27G,
As shown in FIG. 13, a magnet roller gear 89 is attached to the shaft 88 of the magnet roller 82, and a stirrer gear 91 is attached to the shaft 90 of the stirrer 84 and meshes with the developing roller gear 89. has been done. On the other hand, a developing unit drive motor 92 and a developing unit driving gear 93 driven by the developing unit drive motor 92 are provided on the main body 1 side.
When the developer approaches the photoreceptor drum 12, the developer drive gear 9
3 meshes with eight magnet roller gears, so that the magnet roller gear 89 and the agitator gear 91 are driven. J3.94 is toner supply roller 86
This is a replenishment roller drive gear for driving the roller. As shown in FIG. 14, the second developing device 27d has two
The developing device sections 100 and 100 are integrally constructed. In other words, there are two developing units 1 in the developing unit case 101.
00 are provided in two upper and lower stages, and the upper and lower developing device sections 100 and 100 each contain developer G, which is a mixture of toner T and magnetic carrier C in an appropriate ratio. This developer G is conveyed by magnet rollers 102 and 103 containing a built-in magnet, and after being regulated to a predetermined layer thickness by a doctor blade 104 and 105, it is supplied onto the photoreceptor drum 12. An electrostatic latent image previously formed thereon is adapted to be developed. Further, 106 and 107 are agitators, which mix and stir the toner T and the developer G, which are replenished when the toner degree in the developer G decreases, to maintain a uniform toner concentration in the developer G. It is something to do. At the upper part of the lower developing unit 100 of the developing unit case 101 and adjacent to the upper developing unit 100,
A toner hopper portion 108 storing l-toner hopper is provided, and this toner hopper portion 108 is connected to the toner replenishing roller 10.
The rotation of 9 replenishes 1-toner T onto the agitator 106 in the lower developing unit ioo through the toner replenishing port 110, and the rotation of the toner replenishing conveyor 111 replenishes the 1-ner T onto the agitator 106 in the lower developing unit 100 through the toner replenishing port 110. The 1-ner king is supplied onto the stirrer 107 inside. As shown in FIG. 15, on the Freon 1 side of the second developing device 27d, there are magnet roller gears 114, 115. Stirrer gear 118,1 mounted on the shaft 116,117 of the stirrer 106,107
19, an intermediate gear 120 for interlocking and stirring the magnet roller 103 with the magnet l-[:]-ra 102, and an intermediate gear 121 for interlocking the stirrer gear 107 with the magnet 1-[cola 103 are disposed. There is. Then, the developing device 27d of 14 is selected in the current position, and the photosensitive drum 12 is selected.

[When this approaches, the developing device drive gear 93 meshes with the magnetic screw 1 to the roller gear 114, and the magnetic screw 1-○-ra V7114
．． 115 and agitator gears 118, 119. Note that 122 is a replenishment roller drive gear for driving the toner replenishment roller drive gear 108, and 123 is a conveyor drive gear for driving the toner replenishment conveyor 111. Further, the copying process speed is faster when the second developer 27d is set than when the first developers 27a to 27c are set at the developing position. As shown in FIG. 16, when a color to be developed is selected by a color selector (not shown), the JJF fl device corresponding to the selected color is transferred to the second developing device 27d.
When the process speed Vp is high, the process speed vH
On the other hand, when the first developing units 27a to 27c are used, the process speed is set to a low process speed VL. Then, when the copying operation is started, each drive unit operates at a speed corresponding to this process speed Vp. Next, a copying operation in such a configuration will be explained. First, set the original on the stacking table 2. For example, if you write a black charcoal copy as 11, then the second page containing black toner will be placed.
In order to select the developing device 27d, the developing device 14 is first moved in a direction away from the photosensitive drum 12 (to the right). In this way, when the movement of the developing device 14 is completed, the selection motor 39 is operated, and the rotating frames 34a, 34b are rotated.
By rotating each developer 2 as described above,
7a to 27d are caused to revolve while maintaining the parallel state, and when the selected developing device 27a to 27d faces the photosensitive drum 12, the revolution is stopped. When this operation is about to end, the developing device 14 is moved toward the photosensitive drum 12, and the selected developing device 27a-27cj is set close to the photosensitive drum 12 so that it is located within the photosensitive drum 12. With the above operation, the selection operation of the developing device 27d corresponding to the selected and designated color is completed, and black copying is performed again. Next, a copying operation is started, and black copying is performed at a process speed Vp corresponding to the second developing device 27d, that is, a fast process speed vH. That is, exposure is performed as a document is scanned, and the photoreceptor drum 1 formed by this exposure
The electrostatic latent image on 2 is visualized by two magnet rollers of the second developing device 27d, and this visualized toner image is transferred onto the supplied paper p. Next, the paper p, on which the transfer of the l-ner brass has been completed, is sent between the two heaters 1-0-22 and 22 by the conveyor belt 21, and is fixed at 11 mouth pressure. The fixed paper p is discharged onto the tray 24 by the paper discharge rollers 23 23 . As described above, high-speed copying is performed (1). Note that when the first developing devices 27a to 27c are selected, the process speed is slower than when the second developing device 27d is used. According to the above configuration, the first developing units 27a to 27c consisting of the developing unit 100 of !4′! system and the two developing units 10
A second developing device 27d in which 0 and 100 are integrated is provided, and these first and second developing devices 27a to 27d are
One developing unit 27a to 2 is maintained in a flat state at a position apart from the body drum 12 and rotates around the body.
7d is selected; and the selected developing devices 27a to 27d are
Copying when the first developing units 27a to 27c are set in the developing position close to the photosensitive drum 12, and the first developing units 27a to 27c are set in the developing position close to the photosensitive drum 12. The process speed Vt, , Jl is higher than the copy processing speed vH when the second developing device 27d is being sent to the cellar 1.C1 The second developing device 27d
high-speed copying and first and second developing units 27a to 2
Multi-color switching copying can be performed by switching 7d. [Effects of the Invention] As explained above, according to the present invention, in an image forming apparatus that develops a latent image on a carrier, at least one or more units comprising a developing unit of an IP body are used. A first developing device, at least one second developing device which is integrated with a developing device portion having at least two rotations, and these first developing device J5 and second developing device.
A revolution unit that selects one developer by rotating it while keeping it in a flat state, and a movement unit that moves the developer selected by this revolution unit toward and away from the image carrier. When the first developing device is placed at a developing position close to the image carrier, the speed of the image forming process is such that the second developing device is placed at a developing position near the image carrier.
Since the image forming process speed is increased when the image forming apparatus is set to -, it has improved effects such as high-speed copying and multi-color switching copying.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view schematically showing the state of the main body during copying operation, and FIG. mi!7i front view shown in Figure 3 is a side view of the revolution unit,
Figure 4 is a front view of the revolving unit, Section 5 is TL 242 of the rear coupling part, Figure 6 is a perspective view of the front coupling part, and Figures 7 (A) to (C) are the front side. Fig. 8 is a perspective view showing the current @vI device, Fig. 9 is a front view showing the developing device, Fig. 10 is a diagram showing the connection mechanism, Fig. 11 (A) ( b) is contact/separation 1
12 is a vertical cross-sectional view of the first developing device;
FIG. 13 is a perspective view showing the drive system of the first developing device;
The figure is a vertical sectional view of the second developing device, FIG. 15 is a perspective view of the drive system of the second developing device, FIG. 16 is a flowchart showing the process speed designation procedure, and FIG. It is a perspective view showing the main building with a part cut away. 12... Image carrier (photosensitive drum), 27a to 27c
...First developer, 27d...Second developer, 2B
...Revolving unit l-162...Contact M mechanism, 100.
...Developer section. Applicant's Representative Patent Attorney Takehiko Suzue Figure 3 Figure 5 Figure 6 (A)

Claims (1)

[Claims] In a device that develops a latent image on an image carrier, at least one first developing device is composed of a single developing device section, and at least one first developing device is composed of at least two or more developing device sections. By rotating the second developing device and the first and second developing devices while keeping them in parallel,
a rotating unit for selecting one of the developing devices; and a moving/separating mechanism for moving the developing device selected by the rotating unit toward and away from the image carrier; An image forming apparatus characterized in that the image forming process speed when the second developing device is set is faster than the image forming process speed when the first developing device is set.