JPS61212866A - Image forming device - Google Patents

Abstract

PURPOSE:To lighten the weight of a developing device and to shorten the replacement time of a developing unit by holding a developing unit receiver by a planetary gear train so that the directions of plural developing units supported by the developing unit receiver can be equal. CONSTITUTION:Four sets of planetary gear pairs 49-52 are disposed in the vicinity of a fixed bear 48 at the central position of a pair of cross rotating frames 46, which are fixed at both ends of a spindle 45, and four pairs of developing unit receivers 42 are fixed on respective rotating spindles 53. Four developing units 24 are provided between the developing unit receivers, and therefore each developing unit 24 revolutes while it holds its horizontal state, when the spindle 45 rotates. Then any one of the developing units is selected and approached to a photosensitive body. Since a developer unit holding mechanism 47 holds both sides of the developing unit, each developing unit need not be connected, which results in lightening of the weight and shortening the replacement time of the developing unit, and the occurrence of the twist vibration can be prevented by supporting both ends of the developing unit.

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 that can perform multicolor copying, for example.

[Problems with Technical Background of the Invention J For example, in the case of copying machines, in recent years it has been considered that copying images with different colors can be obtained by replacing the developing device or the unit including the developing device. However, in such a copying machine, it is extremely troublesome to replace the current WA machine or unit 1-, and it is very inconvenient.

Therefore, recently, devices configured as shown in FIGS. 12 to 15 have been known.

That is, numeral 1 in FIG. 12 is a photosensitive drum, and a developing device 2 is disposed near it. As shown in FIG. 13, this developing device 2 includes four developing device receivers 38 to 3.
d, and a developing device 4 is provided for each of these receptors 3a to 3d.
8-4 [1 is set] What is the configuration? Here, each of the developing units 4a to 4d contains toner of a different color. In addition, each of the current ridge receivers 38 to 3d has a cross-shaped rotating frame 5, as shown in FIGS. 14 and 15.
are provided in each. That is, the rotating frame 5
is rotatable around the center of the fixed gear 6, and is surrounded by four sets of planets around the fixed gear 6.
ft7a, 7b, 8a, 8b, 9a.

9b, 10a, 10b are arranged respectively, and each of these planets-ft7a, 7b, 8a, 8b, 9a, 9b,
10a.

10b is provided on the rotating frame 5 for each set. and the outer planetary gear 7b.

Each of the rotating shafts 11a to 11dk of 8b, 9b, and 10b: the current ridge receiver 38-3d is fixed, respectively. However, each of the above planets - f ya 7 a, 7 b, 8 a, 8
b, 9 a.

9b, 10a, and 10b have the same number of teeth, and since the fixed gear 6 is fixed, even if the rotating frame 5 is rotated, the outer planetary gears 7b, 8b.

9b and 10b do not rotate. For this reason, the current bulge receiver 38
~3d (developers 4a to 4d) always revolve while maintaining a parallel state M (horizontal state), so that one developer (for example, 7'lb) is selected. . Note that the rotating frame 5 has a gear r"12.
．． It is designed to be rotationally driven by a motor 14 via a deceleration means such as 13 or the like.

Further, the developer device 2 is movable in the direction toward and away from the photoreceptor drum 1, and selection of the developing devices 48 to 4d is performed at a position away from the photoreceptor drum 1.

However, in the above configuration, the fixed gear 6 and the planetary gears 7a, 7b, 8a, 8b, 9a, 91+, 10a.

The developing device receivers 38 to 3d (developing devices 7Ia to 4d) are held in a parallel state by holding the developing device receivers 38 to 3d (developing devices 7Ia to 4d) in parallel. , the developing device receivers 38 to 3d must be sturdy, which increases their importance.For this reason, it is not possible to shorten the replacement time of the developing devices 48 to 4 (1), and the torsional vibrations There was a problem that it was easy to occur.

[Object of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to reduce the eaves of the developing device receiver, thereby shortening the time for replacing the developing device. Moreover, it is an object of the present invention to provide an image forming apparatus that can prevent torsional vibrations that tend to occur when the image forming apparatus is supported on one side.

[Summary of the Invention] In order to achieve the above object, the present invention selects one developing device by rotating a plurality of developing devices while keeping them in a parallel state, and uses the selected developing device to develop an image carrier. In an image forming apparatus configured to develop a latent image on the
The present invention is characterized in that holding means are provided on both sides of the developing device for holding developing device receivers that support the developing device so that the plurality of developing devices are oriented in a fixed direction.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 8.

FIG. 2 shows a copying machine capable of multiple copying as an example of an image forming apparatus according to the present invention. That is, 11 is a main body of a copying machine, and a document table 12 for holding a document is fixed to the upper surface of the main body 11.

The original set on the original platen 12 is processed by an optical system consisting of an exposure lamp 13 and mirrors 14, 15, and 16 reciprocating along the lower surface of the original platen 12.
Exposure scanning is performed during the forward movement. In this case, the mirrors 15 and 16 move at half the speed of the mirror 14 so as to keep the optical path length constant. The light reflected from the original by the scanning of the optical system, that is, the light reflected from the original by the light irradiation of the exposure lamp 13, is reflected from the original by the mirror 14°1.
5.16, passes through the copying magnification setting lens block 17, is further reflected by the mirrors 18.19.20, is guided through the slit 21 to the photosensitive drum 22 as an image carrier, and is the original image. The image is formed on the surface of the photoreceptor drum 22. The photosensitive drum 22 rotates in a predetermined direction, and first the charger 2 for charging
3, the surface of the original is charged, and then the image of the original is exposed to slit light to form an electrostatic latent image. The structure is such that it can be developed by being attached with it.

On the other hand, the paper P is taken out one by one from the paper cassette 25 by the paper feed roller 26, guided through the paper guide path 27 to a pair of registration rollers 28, aligned by the registration rollers 28, and transferred to the image transfer section. configured to be sent. The paper feed cassette 25 is detachably provided at the lower right end of the main body 11. Thus, the paper P sent to the image transfer section is brought into close contact with the surface of the photosensitive drum 22 at the transfer charger 29, so that the charger 29
The toner image on the photosensitive drum 22 is transferred by two actions. The paper P to which this toner image has been transferred is transferred to a peeling charger 3
The transfer image is electrostatically peeled off from the photoreceptor drum 22 by the action of the transfer belt 31 and conveyed to the fixing device 32 provided at the end of the conveyor belt 31, where the transferred image is fixed. After fixing, the MP is sent to a pair of paper ejection rollers 34 by a pair of transport rollers 33, and is ejected to a tray 35 outside the main body 11 by the paper ejection rollers 34. Further, the photosensitive drum 22 after the transfer is configured such that after the residual 1 henna on the surface is removed by the cleaner 36, the residual image is erased by the discharge lamp 37 and the image is returned to the initial state.

Further, a guide selector 3 is provided between the conveying roller 33 and the paper ejecting roller 34 to switch the traveling direction of the sheet P to be conveyed.
8 is offset by jQ, and by the operation of this selector 38, the paper P sent by the transport roller 33 during normal copying is guided to the paper ejection roller 34, and during multiple copying, the paper P is guided to the transport roller 33.
The paper P fed is guided to a paper guide path 39 that guides the paper P downwardly of the main body 11. Then, the paper P guided to the paper guide path 39 is guided to a conveyance path 40 provided on the bottom side of the main body 11, and is conveyed by this conveyance path 40 to a position near the paper feed cassette 25. Road 4
1 to the registration roller 28. That is, during multiple copying, the paper P is circulated as shown by the arrow in the figure.

The developing device 24 includes, for example, four developing devices 24a to 2.
4d, and by making these developing devices 24a to 24d revolve while maintaining a parallel state (horizontal state), one of the developing devices 24a to 24d can be selected.

Further, this trigonometric image device 24 is movable in the left-right direction (a direction toward and away from the photoreceptor drum 22) by a moving means (not shown). That is, during the copying operation, as shown in FIG. Yes, developing units 24a to 24
．． When selecting d, the photosensitive drum 2 is moved as shown in FIG.
The developing units 24a to 24d are moved to a position a predetermined distance away from the developing units 24a to 24d.

When this selection operation is completed, the photosensitive drum 22 is moved again, and as shown in FIG. 2, the selected developer 24a, for example, is set opposite to the photosensitive drum 22.

The developing device 24 will be described in detail below. For example, as shown in FIG. 1, FIG. 4, and FIG.
42dl, 42+42 are placed, these 4
Pair of current ridge receivers 42a1.4282-42dl, 42
Developing units 24a to 24d are installed between each of d2. That is, each developing device 24a to 27
Engagement protrusions 43 are protruded on both sides of 1d,
This engagement convex portion 43... is the current protrusion receiver 42a1. l1
12a2~42dl, 42d2+7) Engagement recess 44・
It is designed to engage with... Here, for example, black toner is placed in the developing device 24a, red toner 1 to 1 is placed in the developing device 24b, green toner is placed in the developing device 21, and green toner is placed in the developing device 24d.
Assume that each contains blue toner.

In addition, as shown in FIGS. 1 and 6, each of the above-mentioned current ridge receivers 42al, 42a2 to 42dl, 42d2c,
provided on a pair of cross-shaped rotating frames 46a and 46b fixed near both ends of the shirts 1 to 45, respectively;
Developing device receivers 42a1, 42a2 to 42dl are provided on both sides of the rotating frames 46a and 46b so that the developing devices 24a to 24d are oriented in a fixed direction.

Holding mechanisms 47a and 47b are provided to hold 42d2. That is, the shaft 45 to which the rotating frames 4'6a and 46b are fixed is rotatable around the center of the fixed gears 48a and 48b, and four sets of shafts are arranged around the fixed gears 48a and 48b. Planetary gear 49a
1. '49bl~52al,'52b1゜49a2
．． 49b2 to 52a2, 52b2 are arranged, and these gears 49a1, 49bl to 52al,
52b1. 49a2. 49b2-52a2. 5
2b2 is provided for each set on the rotating frames 46a and 46b. And the outer gear 4911
Each rotating shaft 53 of 1 to 52b1, 49b2 to 52b2...
・Existing bulge receiver 42a1.42a2-42dl, 42
d2 are each fixed. Therefore, each of the gears 48a, 49al, 49b1 to 52a1.52b
l.

48b, 49a2.49b2 to 52a2.52b2
Both have the same number of teeth, and the fixed gears 48a and 48b
are fixed, even if the rotating frames 46a and 46b are rotated, the gears 49b1 to 52b1 and 49b2 to 52
b2 does not rotate. For this reason, the current ridge receiver 42a1.4
2a2~zl 2dl, 42d2 (Developer 24a~
24d) will always revolve at the same angle, that is, while maintaining a parallel state (parallel state).

This is a necessary operation because the developing units 24a to 24d contain powder carrier (toner). Therefore, the shafts 45 of the rotating frames 46a, 46b are
It is configured to be rotationally driven by a pulse motor (selection motor) 55 via a deceleration means 54 such as a gear.

On the other hand, as shown in FIG. 7, each of the developing devices 24a to 24d is provided with developing device gears 57a to 57d and idle gears 58a to 58d, respectively, for driving developing rollers 56a to 56d.

On the other hand, developing rollers 56'a to 56 are provided on the main body 11 side.
Five drive gears are provided for driving d, and when a selected developer 24a to 24d of the developing device 24 approaches the photoreceptor drum 22, the gear 5 is activated as shown in FIG.
9 meshes with gears 58a to 58d, gears 59→58a to
The driving is performed in the order of 58d→57a to 57d.

In addition, the current bulge receivers 42a1.42a2 to 42dl.

Guide members 60a to 60d are each fixed to 42d2, while a guide bin 61 is fixed to the main body 11 side, and these are in a spigot relationship with each other. Thereby, when the developing device 24 approaches the photosensitive drum 22, it is guided smoothly and accurately, and the positional relationship between the photosensitive drum 22 and the selected developing devices 24a to 24d can be accurately obtained.

Next, the operation in such a configuration will be explained.

In the case of multiple copy mode, first place the first document on the document table 12.
For example, if a red copy is to be made first, the developing device 24 is moved away from the photoreceptor drum 22 (to the right) in order to select the developing device 24b containing red colors 1 to 1. and set it to the state shown in Figure 3. In this way, when the movement of the developing device 24 is completed, the selection motor 55 is operated, and the rotating frames 46a, 46b are
By rotating , each of the developing units 24 a to 24 d is caused to revolve while maintaining the parallel state as described above, and when the developing unit 24 b to be selected faces the photosensitive drum 22 , its revolution is started. Stop.

When this operation is completed, the developing device 24 is connected to the photosensitive drum 2.
2 side, and the selected developing device 24b is set in a state where it approaches and faces the photosensitive drum 22, as shown in FIG. M2. With the above operation, the selection operation of the developing device 24b corresponding to the selected and designated color is completed, and red copying becomes possible. Next, a copying operation is started, and red copying is performed using the developing device 24b. That is, exposure is performed as the original is scanned, and the electrostatic latent image formed on the photoreceptor drum 22 by this exposure is visualized by the developer 24b, and this visualized toner image is supplied. The image is transferred onto the MP for use. Next, the paper P on which the toner image has been transferred is transferred to both heat rollers 3 by the conveyor belt 31.
28 and 32b, is pressed and fixed, and is sent to the conveyance roller 33. The paper P that has been fixed is transferred to the transport roller 3.
3, the selector 38 is set at the solid line position in FIG. The conveyance path 40 transports the paper P through the registration row 5.
28, and is temporarily stopped at that position to prepare for the next color copying operation.

Next, the second original is set, and in order to stop multiple copying, the multiple copying mode is canceled and the developing unit 24a containing black toner is removed by the same selection operation as described above.
is selected, and black copying becomes possible. Note that if you want to continue multiple copying again here, you can leave the multiple copying mode as it is.

In this way, when the multiple copy mode is canceled, the same copying operation as described above is started, and black copying is performed using the developing device 24a. In this case, a black copy is made superimposed on the previously made red copy. However, when overlapping copying was completed, M
When the paper P is sent by the conveyance roller 33, the selector 38 is set at the position indicated by the broken line in FIG. Multiple copies are performed in the manner described above. Note that by continuing to use the multiple copying mode without canceling it, it is also possible to duplicate blue and green colors.

According to the above configuration, the IM 1mm container body 42a1°42
82~42dl, 42d2 holding 711 holding mechanism 47
A and 47b are provided on both sides of the developing devices 24a to 241), so that the developing device receivers 42al are opposed to each other.

42a2 to 42d1.42d2 are no longer required to connect, and the weight is lighter (and the diameter of the rotating shaft 53 that holds them can be reduced as well, and torsional vibrations during revolution can be reduced). can be prevented.

Note that FIGS. 9 to 11 show other embodiments of the holding mechanisms 47a to 47b. That is, a booth 62 is fixed to one end of the shaft 45. Further, a timing belt 64 is stretched between this pulley 62 and a pulley 63 fixed to the rotating shaft 55a of the motor 55. The driving force from the motor 55 is transmitted to the shaft 45 at a reduced speed, thereby rotating the frame 46a.

46b is rotatably driven. Furthermore, fixed pulleys 65a are provided at both ends of the shaft 45.

65b is fitted onto the outside, which is rotatable relative to the shaft 45 but fixed relative to the body 11. That is, the rotating frame 16a.

Fixed pulleys 65a and 65b do not rotate even if 46b rotates. In addition, the above-mentioned current bulge receiver 42
a1.42a2 to 42d1.42d2 are rotatably attached to the tip sides of the rotating frames 46a and 46b, and each of the current ridge receivers 42a1.42a2 to 42d1.42d
2 rotation shaft 53... has a planetary pulley (revolving pulley)
66a1, 66a2 to 66dl, and 66d2 are each fixed. In addition, the identification pulley 65a (65b
) and planetary pulley 66a1゜66b1 (6682,
66b2) between the timing belt 67al (67a2)
), a timing belt (t-67b1<67b2) is hung between the fixed pulley 65a (65b) and the planetary pulley 66c1.66dl (66c2°66d2). Thus, the fixed pulleys 65a, 65b and each planetary pulley 55al.

66a2~6.6dl, 66d2 have the same outer diameter, and when the rotating frames 46a, 46b rotate, the planetary pulleys 66a1.66a2~66dl, 6
6d2 revolves without rotating. For this reason, the current ridge receivers 42al, 42a2 to 42dl, 42d2 (
The developing units 24a to 24d) always revolve while maintaining a parallel state.

Further, in the above embodiments, the case where the application is applied to a copying machine capable of multi-color multi-copying has been described, but the present invention is not limited to this. The invention can be similarly applied to copying machines that can make copies.

Further, in the above embodiments, the case where the present invention is applied to a copying machine has been described, but the present invention is not limited thereto, and can be applied to other image forming apparatuses such as, for example, an electronic printer, a facsimile machine, or a printing machine.

[Effects of the Invention] As explained above, according to the present invention, one developing device is selected by rotating a plurality of developing devices while keeping them in a parallel state, and the selected developing device is used to develop images on an image carrier. In an image forming apparatus configured to develop a latent image of -
A developing device receiver for supporting the V-marked imager, and a holding means for holding the developing device receiver so that the plurality of developing devices are oriented in a fixed direction, and the holding means is configured to support the developing device. Since they are provided on both sides of the container, it is possible to reduce the weight of the developing device receiver, thereby shortening the time for replacing the developing device, and also prevents torsional vibration that tends to occur when supporting one side. It has excellent effects such as:

[Brief explanation of drawings]

Figures 1 to 8 show one embodiment of the present invention.
The figure is a vertical side view of the developing device, Figures 2 and 3 are schematic vertical front views of the copying machine, Figure 4 is a vertical front view of the developing device, and Figure 5 is a receiver of the developing device. 6 is a diagram showing the rotating arm portion, FIGS. 7 and 8 are configuration diagrams for explaining the positioning mechanism of the developing device with respect to the photosensitive drum and the driving mechanism of the developing device, and FIGS. Fig. 11 shows another embodiment of the holding mechanism, Fig. 9 is a view showing the rotating arm portion, Fig. 10 is a vertical side view of the developing device, and Fig. 11 is a view showing the 1F passing state of the timing belt. , FIG. 12 to FIG. 15 show a conventional example, in which FIG. 12 is a longitudinal sectional front view showing the developing device, FIG. 13 is a sectional view showing the receiver of the developing device, and FIG. 14 is a rotating arm portion. Figure shown, 1st
FIG. 5 is a vertical side view of the developing device. 22... Image carrier (photosensitive drum), 24a to 24d
・JJ! Imager, 42a1.42a2-42dl. 42d2... Current ridge receiver, 47a, 47b... Holding mechanism, 48a, 48b=-- Fixed gear, 49a1.49
b1~52al, 52bl, 49a2.49b2~
52a2.52b2... Planetary gear, 65a, 65b.
・・Fixed pulley, 66a1゜66a2~66dl,
66 d2...Revolving pulley (planetary pulley). Applicant's representative Patent attorney Takehiko Suzue Figure 4 Figure 5 Figure 6 Figure 7 Figure 12 Figure 13 Figure 14 Figure 15 b 3a 7a b 1c

Claims (3)

[Claims] (1) In a device in which a plurality of developing devices are rotated while being maintained in a parallel state, one developing device is selected, and the latent image on the image carrier is developed by the selected developing device. A developing device receiver for supporting the developing device, and a holding means for holding the developing device receiver so that the plurality of developing devices are oriented in a fixed direction, and the holding means is provided on both sides of the developing device. An image forming apparatus characterized in that each of these is provided. (2) The image forming apparatus according to claim 1, wherein the holding means is a planetary gear train having a fixed gear disposed at the center of revolution of the developing device. (3) The holding means includes a fixed pulley disposed at the center of revolution of the developing device, and a revolving pulley fixed with respect to the developing device;
2. The image forming apparatus according to claim 1, further comprising a timing belt stretched between the revolving pulley and the fixed pulley.