JPH05505251A - A developing device having means for moving a developing unit in parallel when generating a multicolor image - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Field of the Invention: Development Apparatus Having Means for Translating a Development Unit When Creating a Multicolor Image TECHNICAL FIELD This invention relates to the development of electrostatic images. The present invention particularly provides a method for using different toners, e.g. Uses toner of different colors to develop → electrostatic images.

freight shipping technique Yamada U.S. Patent No. 4,928,146, issued May 22, 1990. In this method, toners of different colors are carried on a photoconductive drum at one development stage. A number of reference examples have been described showing the development of a series of electrostatic images. Also, in 1974, Japanese and Other U.S. Patent No. 3,797,930, issued on May 17, 19 Knechtel U.S. Patent issued June 23, 1981 4.275.134, Japanese Patent Publication No. 1-244477 (1989 ) and Zwaldo's U.S. dated March 1, 1988. See patent no. 4,728.983. A series of four developing stations They are successively moved to the development position l. Develop the image at each station, then move to the → station. When determining the color toner and applying a different color toner to the next image, the be replaced. A series of stations are arranged in parallel to the station is moved linearly through the position to align the station with the development position. After alignment or During alignment, a cam is rotated to push the entire station toward the development position, roughly Move across a series of station operations.

This general approach uses only one development position 1 to produce an electrostatic image of four different colors. It has the effect of applying toner. This allows for size and number It would have been impossible to space multiple photoconductive drums around a relatively small photoconductive drum. It became possible to use several development stations. Also, when forming multicolor images, small It also became possible to use molded drums. The use of small drums reduces costs and equipment It has many advantages such as miniaturization and convenience in cartridge replacement. There is.

In the structures shown in the prior art, comparison of relatively long and narrow stations and image members Precise parallel translation of four stations to maintain alignment with long and narrow sections of the target movement is required, The four developing units are positioned on a carriage mounted on a rail. is typical. The carriage is driven on rails by a chain or belt drive. It will be done. The rails maintain the alignment of the carriage as it moves, and the rails keep each developer unit aligned. place the parts in sequence. However, if the chain or held drive is used, the device will not work properly. It is complicated and costly, and it is difficult to assemble and maintain. becomes.

Casamura U.S. Patent No. 4,941,01 issued July 10, 1990 No. 8 is connected to the rack on the developer carriage and the mechanism board of the printer in Figure 27. Shows indexing of toning station using mated pinion . The rack and pinion solution provides sufficient power and smooth drive for such structures. possible. The development carriage is moved using a long guide structure separate from the rail and drive device. controlled by

Disclosure of invention An object of the present invention is to apply toners of different colors to a single layer carried on an image member at a development position. An object of the present invention is to provide an apparatus for applying a series of electrostatic images, the apparatus comprising a movable carriage. F includes multiple developer units positioned in parallel relationship, but is accurate and reliable. A means for moving the carriage in parallel is provided, which is easy to assemble and has a simple structure.

The above and other objects are generally positioned in parallel relationship on a movable carriage. This is achieved by a developing device having a plurality of developing units. The carriage is parallel It includes a moving plate and a pinion fixed to the plate. The parallel movement plate is at the development position It is mounted to move along a rack that is fixed to a rack. The pinion is Engage the rack. When the pinion rotates, the translation plate moves to move the carriage in parallel. Moving.

According to a preferred embodiment, the device of the invention includes a floor to which the rack is fixed. plural A roller is attached to the bottom of the translation plate to support the translation plate and move it along the rack. engages the floor to be moved.

According to another preferred embodiment, the rack is part of an elongated member having a T-shaped cross section. . A rack is formed on the top surface of the T, and the stem-like part has a rail facing in the opposite direction. 9, supported by a translation plate - the pair of rollers engages one rail and the third roller engages the opposite rail 5, and the third roller engages the long member. The rollers align the translation plate with the rack to ensure alignment between the pinion and the rack. 2, which are positioned to maintain the carriage and ensure accurate translation of the carriage. According to yet another embodiment of the invention, the rack is arranged on the side of the elongated member and The roller will be coaxial with one of the rollers of the previous embodiment. In this example, the rack It saves some parts compared to having it on the top and has only one strong spring (the third one). (on the roller) to maintain engagement between the rack and pinion.

This structure allows for high precision with low friction and is reliable at relatively low cost. . Compared to traditional pulleys, cables or other rack and pinion equipment , the drive guide has the same components and both functions are provided, and two sets of different Eliminates the need to align components. In this construction, the pinion is located at the end of the rack. Alternatively, since it can be driven against the end, less space is required in the lateral direction. Furthermore, the department Requires very little equipment (and no belts or cables) Ru. Assembly, shipping and maintenance become easier.

Brief description of the drawing For a detailed description of the preferred embodiments of the invention set forth below, reference is made to the accompanying drawings. illuminated.

FIG. 1 is a schematic front view of an image forming apparatus of the type in which the present invention is useful.

Figure 2 shows a rack/binion translation plate with a portion cut out for clarity. FIG. 2 is a perspective view of a developer device similar to the device shown in FIG. 1 illustrating.

3 is a perspective view of a pinion engaging a portion of the rack shown in FIG. 2; FIG.

FIG. 4 is a bottom view of the translation plate and rack shown in FIGS. 2 and 3.

FIG. 5 is a left side view of the translation plate and rack shown in FIGS. 2 and 4. FIG.

6 is an enlarged left side view of a portion of the structure shown in FIG. 5. FIG.

7 and 8 are a side view and a bottom view of the representative example of the structure shown in FIGS. 4, 5, and 6. Figure 5 is shown.

9 and 10 are a sectional view and a side view of the sliding fit structure of the wheel shown in FIGS. 7 and 8. It is.

11, 12 and 13 are respectively 10 lines A-A, B-B and C- It is a figure along C.

BEST MODE FOR CARRYING OUT THE INVENTION According to FIG. 1, an electrophotographic color printer 1 rotates through a series of stations. The technique is applied onto the transfer roller 3 or the image receiving sheet supported by the transfer roller 3. The photoconductive drum 2 includes a photoconductive drum 2 for producing a multicolor toner image in a manner known in the art. Than Specifically, the drum 2 is uniformly charged at the charging station 6, for example, A series of static lights are fogged in the direction of the image by an exposure station such as laser light transport station 5. Generate an electric image. Electrostatic imaging applies a different color of toner to each image in a series. A developing device 4 forms a series of toner images of different colors. series of The toner image is then transferred in registration to the surface associated with transfer roller 3.

The surface associated with the transfer roller 3 is the surface of the transfer roller 3 or the surface of the transfer roller 3. It may be any surface of the image receiving sheet fixed to the surface of the image receiving sheet. multicolor image directly When it is formed on the surface of the transfer roller 3, it is formed on the drum 2 by means not shown. The multicolor image is transferred to the image receiving sheet at a remote location, making optimal use of the multicolor image. -0 When a multicolor image is formed on the surface of the image receiving sheet carried by the transfer roller 3 In this case, the sheet is transferred to a transfer roller at a location remote from the drum 2 by means not shown. - separated from 3.

The photoconductive drum 2 is made very compact, its circumference approximately smaller than a single image.

The miniaturization of the photoconductive drum means that, for example, replacing the photoconductive drum can be done on the charging station. 6 and a cleaning station. can be done. Miniaturization also contributes to reducing the size and cost of the printer 1 . Unfortunately, the miniaturization of photoconductive drums leads to continuous electrostatic images of different colored toners. makes the imparting geometrically difficult to achieve. Similar to the conventional techniques referenced above, the The printer 1 has a series of four developer stages 10, 20, 30 and 40 in development position. by moving past the development positions 9 to produce different developments at the only development position 9 associated with the drum 2. The above problem can be solved by applying color tone changes to each electrostatic image using an image unit. Ru.

According to FIG. 1, the developer units 10, 20, 30 and 40 all move laterally. It is fixed in a carriage 50. The carriage 50 is installed on the floor of the printer 1. A set of four support rollers 51 resting on 52 and allowing movement on the floor. has. A drive mechanism for moving the carriage 50 is not shown in FIG. 1, but is shown in FIGS. This is illustrated in more detail in FIG.

In FIG. 1, developer unit 10 is shown aligned with developer position 9. In FIG.

The carriage 50 has a starting position to the left of position l shown in FIG. 1 and moves to the position shown in FIG. Preferably, the first electrostatic image in the series is developed using the same method. Tonal change in first image When the development is completed, the carriage 50 moves again to align the developing unit 20 and move it to the second position. The color tone of the electrostatic image is changed. Units 30 and 40 are also located at developing position 9. When aligned, the third and fourth electrostatic images are changed in tone. The carriage 50 then Return to starting position.

The developing unit 10 is connected to an application device 11, a mixing device such as a paddle 12, and an oven. 13. The mixing device contains a mixture of hard magnetic carrier particles and insulating toner particles. The developing chamber 14 is located within the developing chamber 14. A toner supply section is located within the toner chamber 15. Tona - is supplied from the toner chamber 15 to the developing chamber 14 by a toner supply roller 16 .

The structure and operation of each unit are described in the patent disclosures incorporated herein by reference. U.S. Patent No. 4 to Hill et al., issued January 10, 1989. It is essentially the same as the unit described in No. 797,704. When it works, The paddle 12 and auger 13 rotate to mix the developer in the chamber 14 and raise the developer level. are both performed to allow developer material to enter the magnetic field of the applicator. The above features As explained in more detail in 7 and a fixing sleeve 18. The hard magnetic carrier particles respond to the rotation of the magnetic core. moving around the fixed sleeve 18; The toner chamber 45 of the developing unit 40 is Note that it is larger than the nursery room. The developing unit 40 includes a developing unit 1O1. Contains black toner, which is used more frequently than color toners in 20 and 30. . Units 10, 20 and 30 include cyan, magenta and or high-color toner, such as red, blue, and yellow. It is also possible to store light color toner.

The developing device used in the developing units 10, 20, 30 and 40 is the applying device 11. and tram 2 is required. According to Figure 1, this interval The definition consists of four pieces arranged at both ends of the unit 10, one on each side of the applicator 11. This is accomplished by rollers 60. The roller 60 is shown in FIG. As shown, when the roller and the applying device 1 are pressed against the drum 2, 1 are precisely positioned and sized so that they are precisely spaced.

In the prior art cited above, each developing device is aligned to a developing position. developing unit The cut is oriented toward the development position relative to other units after or during alignment. and is moved to engage the photoconductive drum. To perform the latter operation, the developing unit Each needs to be movable relative to the other. This includes each separate A separate drive means, such as a rotating cam, is required to move the knit, which means The timing must be adjusted according to the stage and the matching operation must be performed.

The developing device shown in Figure 1! 4, the developing units 10, 20, 30 and 40 are placed in the carriage 50. A substantially improved version of the conventional developing device as described above by fixing the developing device to each It is. When each development unit is aligned with the development position 9, the applicator 11 With respect to the rest of the cut, the roller 60 is moved in the direction of the drum 2 to fix the roller 60 on the drum 2. Determined.

In order to achieve the above purpose, the applicator 11 is mounted on the applicator block 71. together with the applicator g111 and the roller 60 to form an applicator assembly.

The applicator block 71 has an opening 72 into which the applicator 11 is attached.

The opening 72 is thicker than the applicator 11 (to prevent developer from the chamber 14 during image development). movement around the sleeve 18. The imparting device block 71 is , an attachment is provided to the means 77 allowing limited movement of said block 71 in the vertical direction. It is fitted more loosely into the side walls 75 and 76. The side wall of the applicator block 71 is the side wall 7 5 and 76 to enable lateral movement and tilting of the applicator block 71. Ru. A pair of glue lids 80 are pivotally attached to both ends of the applicator block 71, and It is loosely attached to the end of the image unit 10. Similar glue lid is for development unit 2. 0.30 and 40.

Immediately below each lifter 80 of the carriage 50 is an engagement bin 83. The engagement bin 83 is A sleeve 84, a pin core 85 installed in the sleeve 84, and the sleeve A spring 86 is provided within the pin core 84 and biases the pin core 85 downward. bottle and pin The pin core 85 and the slot in the sleeve 84 are respectively connected to the sleeve 84 of the pin core 85. This prevents them from being pulled out. A pair of models 90 are connected to one printer by a pivot 91. It is movably fixed and aligned with a series of front and rear engagement pins, respectively.

As shown in FIG. 1, when the carriage 50 is moved from left to right, the developing unit 10 is Each of the engagement pins 83 engages one side 90 to align with the development position. pin 8 3 is a! 90, the pin core 85 moves upward against the force of the spring 86. energized. Next, the spring 86 urges the top of the sleeve 84 into contact with the lifter 80. When the lifter 80 is pressed upward, the lifter 80 is forced upward and comes into contact with the applicator block 71. . The block 71 is configured so that the roller 60 comes into contact with the drum 2 and remains stationary so that the roller 60 is accurately removed from the drum 2. The application device 11 is moved upward until it is positioned at a developing position spaced apart from the developer position.

Once the first electrostatic image is developed, carriage 50 is moved further to the right. gravity and law Two of the rollers 60 move the block 71 and lifter 80 to the lower initial position. energize with. This action is a cantilever motion that urges the block 71 downward against the spring 86. It is supported by a beam spring (not shown). The carriage 50 is the developing unit 20 When the application device 21 is aligned with the exposure position 9 and the engagement bottle 94 is engaged with the pattern 90, application is performed. Move the device 21 to the right until it is in the proper position where the tonal change of the second electrostatic image is made. move. This process is repeated for the developing units 30 and 40, and the &! 90 applicator devices 31 and 4 in response to being engaged with engagement pins 95 and 96, respectively. 1 is moved to a predetermined position.

If a slight amount of misalignment occurs in the developing unit 10, the block 71 Since it is loosely attached between the side walls 75 and 76, the block 71 is also Since it is pivotally attached to the lid 80, the block 71 can be tilted somewhat. and move laterally in a manner controlled by rollers 60 on the surface of drum 2. It remains to be noted that it is possible to precisely space the application devices 11.21.31 and 41. I want to be understood.

The motor 120 is rotated in the opposite direction when the tone change of all four images is completed, and the carriage is rotated. 50 is returned to its initial position on the left. To further clarify FIG. Although the driving waves are not shown in the figure, they are shown in FIGS. 2 to 6.

According to FIGS. 2 to 6, the carriage 50 is spaced apart from the bottom of the developing units 10 to 4o. It includes a fixed translation plate 101. Binion 110 and motor 120 for it is fixed to the top of the translation plate 101 and is attached to the floor 52 by a plate spring 115 (FIG. 3). Spring biased into fixed rack 130. Four rollers 51 (Fig. 1, Fig. 4 and FIG. 5) support the translation plate 101 on the floor 52 and move it flat along the rack 130. Move the line. This movement is done smoothly and with low friction, making it easy for relatively small motors to move. This can be easily achieved with the motor 120.

However, the binion 110 remains engaged with the rack 130 and also reciprocates. It is important that platform 50 maintains accurate alignment with development station 9 and drum 2.

In order to achieve this, the rack 130 must have a T-shaped cross section and a It is formed at the top of elongate member 134 where it is most obvious. The long member 134 is 7 characters long. In addition to having a rack 130 on top of the 138 with side faces of a figure 7 stem forming rails 132 and 133 for the two All of the rollers are mounted on a translation plate 101. roller 136 and 138 is fixed at a predetermined position relative to the translation plate 101 and moved along its movement path. It will be harmonized. These rollers are shown most clearly in Figures 4 and 5. Positioned along left rail 132 to engage elongate member 134 .

A roller 137 is also mounted on the translation plate 101, but the elongated member 134 rollers 136 and 138 are located on opposite sides and between the two rollers. be positioned. The roller 137 is not fixed at the predetermined position 1, but is moved to the right by the spring 141. The side rail 133 is biased and engaged. Spring 141 is essentially roller 137 is pressed against the long member 134, and both rollers 136 and 138 are pressed against the long member 13. 4, 5 and 6 until it firmly engages the left rail 132 of 4. Pull the translation plate 101 to the right so that it becomes clear. This structure allows the roller 136 and 138 are accurately positioned. 0 is effectively aligned.

Motor 120 is pivotally attached to section 122 (FIG. 3). This results in , retaining spring 115 (assisted by the weight of motor 120) latches binion 110. 130 to make the size accurate and install the roller 5]. It is possible to maintain proper engagement between the binion 110 and the rack 130 without the need for Becomes Noh.

Binion 110 is part of a binion element 112 best shown in FIG.

Binion element 112 is positioned on and driven by shaft 116. Binio The bearing element is slidable in the axial direction on the shaft 116 (when assembling, ) and such axial movement is limited at the top of the elongate member 134. Ru. Binion element 112 integrates binion 110 and pitch cylinder 113 into one element. Included as The pitch cylinder 113 is connected to the pitch control surface 117 near the rack 130. Controls the depth of engagement when the rack and pinion engage with each other. Rat The pitch stopper 131 and the rack 130 control the axial movement of the pitch cylinder 113. axial movement of the pinion element 112 is controlled in a limited manner.

To assemble the device, move the carriage 5o into the rack until the binion 110 engages with the rack 130. This is achieved by simply sliding on 130. The binion then drives the carriage to perform the task. position at the desired starting position. Removal is performed in reverse order. Essentially, Binion 110 drives carriage 50 to a usable position or the printer completely (for example, through the side panel of the printer). hand).

This structure is not affected when the device is shipped. equivalent to a printer Even if it moves or shakes, the motor, pinion and latch are supported by spring 115. The mechanical resistance of the components maintains them in the correct position. Weight of motor 120 The spring 115 assists in maintaining the engagement between the rack and the bunion.

With this structure, the translation plate 110 is allowed to follow the rack 130 extremely accurately. If so, align development unit 1-10, 20, 30 and 40 accurately to development position 9. This allows the binion 110 and the rack 130 to be continuously engaged. It becomes possible to leave it there. Low-cost components and construction for minimal friction losses and gains This can be achieved by: Guides and rails (excluding long member 134) ) is removed, it is remarkable that the carriage accurately follows.

Drive carriage 50 has several advantages over the embodiments shown in FIGS. 2-6. Another rank binion structure is shown in FIGS. 7 and 8. the bottom of the developing unit 40 According to FIG. 7, a carriage 50 supports a developer station as in FIG.

. The installation of the carriage 50 will be explained in more detail with reference to FIGS. 9 to 13. It is supported on the floor by wheels 151. The carriage includes the long member 134 of the first embodiment. It is driven along a structurally similar elongated member 234. The elongated member 234 is Member 134 is elongated in that the It is quite different in shape. Rails 232 and 233 are the lower part of long member 234. formed along vertical walls along the

Gear unit 212 is part of carriage 50 and is driven by 90° drive motor 220. It is driven by The gear unit 212 has a roller section 238 and a binion section 210. include.

FIG. 8 is a bottom view taken along line D-D in FIG. 138. Roller 236 is essentially the same as that of FIG. It is the same as roller 136. The position l of the elongated member 234 is shown in phantom in FIG. Ru. The third roller 237 shown in FIGS. 7 and 8 is essentially the third roller of FIG. -137. The roller 237 is attached to the rail 233 by a strong spring 241. spring biased.

The gear unit 212 is engaged with the rack 230 and, as in the first embodiment, is a long member. 234 including a pinion portion 210 that drives carriage 50 along line 234. During this drive, the The roller portion 238 rides on the rail 230 (just as the roller 236 rides). rail 230 is a distance that allows the desired engagement between the binion member 210 and the rack 230 spaced to the left (as viewed in FIG. 7) from rack 230.

When activated, spring 241 ensures that carriage 50 follows along elongated member 234. The rack 230 and the pinion part 210 are controlled by the roller part 238. maintain engagement between. Thus, in the above structure, only one gear unit 212 Separate binion and roller structures that are separately spring biased to their respective operating positions will be replaced by One spring, namely spring 241, is the same as the two springs of the first embodiment. fulfill.

FIG. 7 and FIG. 8 show a wheel 151 that is considerably different in construction from that used for wheel 51 in FIG. Show the structure. This structure is shown in detail in FIGS. 9 to 13, and how it will be explained. I do.

The carriage 50 has wheels 151 molded thereon, which are attached by injection molding together with the structure. includes only one translation plate 201. In this structure, a single piece is the translation plate 210 The mounting for the whole and four wheels 151 includes both the frame. The frame itself for wheel installation is shown in Figure 9. This can be seen most clearly in Figure 10. According to Figures 9 and 1O, each installation The mounting frame includes a yoke 301, a snap 303, and an axle retaining wall 305. these In this member, the wheel 151 is mounted on the axle 307 and the mounting is inserted into the frame. The inserted state is shown in cross section in FIG. Figure 10 shows wheels and axles installed. The mounting not shown is a side view of the frame. Line A- of the yoke 301 (in FIG. 10) A front view along line A is shown in FIG. ) A front view is shown in Figure 12. of the wheel retaining wall 305 (along line C-c in FIG. 10) A front view is shown in FIG.

When injection molding the parallel displacement plate 201, the yaw is applied to the underside of the mold for each stroke. 301, the outside of the snap 303 and the axle retaining wall 305, and the top of the mold. The sides form the inside of the snap 303. Molding can be done in one direction. When standing, the carriage is inverted on a 90" drive motor 220, preferably on a fixture. is set to The only axle 307 goes into the plastic wheel 151 through the clearance hole. inserted. Next, this wheel axle assembly is constructed such that the wheel 151 has two yokes 301 and the axle 307 is held between the car and the retaining wall 305 within the snap 303. The wheel mount is inserted into the frame so that the The yoke 301 controls the axle and wheel position. Define. The feature of Snap 303 is that when the carriage is turned normal side up, it simply snaps. The goal is to keep the wheels from falling. Retaining walls prevent the axle from slipping off the wheel That's what I do. of the yoke 301, the snap-lock feature 303, and the retaining wall 3°5. The sufficiently chamfered surface and the angle of engagement prevent the wheel 151 with the axle 307 from sinking. drop-in installation is facilitated.

With this structure, one part is required for mounting wheels such as the moving plate 201 on both sides of the frame. This enables injection molding in a fixed direction. For wheel mounting, use the frame as an axle retaining wall 305. and snap 303 are combined into a single structure that can also be molded in one direction. It is possible to make slight modifications such as

While the invention has been described in detail with particular reference to the preferred embodiments, the invention has been described above in detail. and without departing from the spirit and scope of the invention as set forth in the appended claims. , changes and modifications may be made.

place seasonal FIG.9 FIG. 12 FIG. 13 FIG, IQ FIG,ll Summary of a developing device having means for moving the developing unit in parallel during multicolor image generation I A developing device that applies different colored toners to an electrostatic image at a single developing position moves in parallel. Each of the series of development units is aligned to a development position. Developing unit (10, 20 , 30, 40) are supported within a movable carriage (50) containing a parallel displacement plate (101). held. A binion (110) supported by a translation plate is attached to a fixed rack (130) the parallel displacement plate is moved while the parallel displacement plate is stationary on the floor of the developing device. It is supported by a roller (60). Align translation plate and binion to rack A pair of rollers (136, 138) are integrated with the rack to keep the The third roller (137) engages one of the opposing rails while the third roller (137) engages one of the opposing rails. The spring is biased toward (133), biasing the translation plate and the binion to the rack. be consistent.

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Claims (10)

[Claims] 1. A plurality of developing units ( 10, 20, 30, 40), in which each unit has a means for applying toner to the electrostatic image. It includes stages (11, 21, 31, 41) and each unit is in contact with the toner of other units. A plurality of developing units containing toners of different colors are used, and the developing units are sequentially developed. means for moving the carriage in a direction of movement to align the carriage, the carriage comprising: A series of electrostatic charges carried in the development position by an image member having a translation plate (101) In a developing device that applies toner of a different color to each image, The transportation means is a guide fixed to the developing position and running in the direction of movement with the rack (130); an elongated member (134) extending in said direction of movement defining means (132, 133); )and, lateral position of said translation plate engaging said guide means and relative to said elongate member; means (136, 137, 13) supported by said translation plate for maintaining 8) and a pinion (110) supported by the translation plate and engaged with the rack; , Rotating the pinion and moving the translation plate to move the translational plate along the guide means. A developing device comprising means (120) for moving a carriage. 2. The translation plate is spaced apart from the support surface, and the support surface is static relative to the development position. and the translation plate is attached to the translation plate and the support a plurality of surfaces that engage a surface and support the carriage for movement along the rack; The developing device according to claim 1, further comprising a roller. 3. Means for engaging the guide means include three alignment rollers supported by the translation plate. two of which are on one side of said elongated member, and one of which is on one side of said elongated member; on the other side of said member, said guiding means comprising rails on opposite sides of said elongated member; The alignment roller is rotatable on the rail, and the rack and the parallel displacement 2. The developing device according to claim 1, wherein alignment between moving plates is maintained. 4. said rack is defined in a vertical plane of said elongate member, and said guide means is also defined in said elongated member. 4. The developing device according to claim 3, wherein the developing device is defined by a vertical surface of the developing member. 5. the rack is defined in a horizontal plane of the elongate member, the member having a T-shaped cross section; according to claim 3, characterized in that said guiding means are defined in a vertical plane of said T. developing device. 6. The one alignment roller is between the other two rollers, and the long spring biased into a member to maintain said other two rollers against said member; Claim 1, wherein the other two rollers are aligned with the rack. The developing device described in . 7. The pinion and one of the three alignment rollers are formed from a single integral member. 5. The developing device according to claim 4, wherein: 8. the rack is defined in a vertical plane of the elongate member and is connected to the pinion and the alignment rod; 6. wherein one of the rollers is formed from a single unitary member. developing device. 9. the one alignment roller is between the other two rollers, and the long spring biased into a member to maintain said other two rollers against said member; Claim 5, wherein the other two rollers are aligned with the rack. The developing device described in . 10. an image member; means for forming a series of electrostatic images on said image member; and means for forming a series of electrostatic images on said image member; means for applying toner of a color different from that applied to the image; and means for transferring the image onto a single surface by aligning registration marks to form a multicolor image. , The means for applying the toner includes a plurality of tone setting units and a means for applying the toner to the image. means for reciprocating in alignment with the member, the means for reciprocating the color tone; A parallel displacement plate that is movable together with the setting unit, and a pin attached to the parallel displacement plate. the unit including a translation plate guide means fixed to the translation plate; a means for reciprocating the image member, and a means for reciprocating the image member, and a means for reciprocating a rack for reciprocating the color tone setting unit; fixed, and the translation plate is engageable so that the space between the rack and pinion is fixed. the translation while maintaining engagement and the translation plate moves along the rack; An image forming apparatus comprising: a guide means for guiding a plate.