JPH0321962A - color image forming device - 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 [Industrial Application Field] The present invention includes a plurality of developing devices containing colored toners of different colors, and by selectively causing these developing devices to act on an image forming body. The present invention relates to a color image forming apparatus that outputs monochrome prints of desired colors, multicolor prints of two or three colors, or full color prints.

[Prior Art] Image forming apparatuses such as those described above have been put into practical use as electrophotographic color copying machines, and in recent years in particular, they can be used not only as analog copying machines but also as output printers for electronic filing systems and CAD systems. Digital copying machines have come into practical use. Conventionally, as a developing device of such an image forming apparatus, (1) colored toners of different colors (for example, yellow, magenta, cyan, black) are applied along a tram-shaped or helt-shaped image forming body carrying a latent image; This is a parallel type in which developing devices containing a desired color are arranged in parallel, and only the developing device of the desired color is located at a working position close to the image forming body, while the other developing devices are retracted to a non-working position retreating from the image forming body. The configuration is known, or (2) developing units containing colored toners of the four different colors are provided on all four sides of a rotating body in the circumferential direction, and this rotating body is intermittently rotated in one direction during exposure. A turret type structure is known in which a developing device corresponding to an exposure color is faced to an image forming body.

[Problem to be solved by the invention] In such a conventional device, in the former configuration,
The problem is that while the selected one developing device is in use, it is necessary to pull the other developing devices away from the image forming body, so a large amount of space must be provided for arranging the developing device. It has points. Furthermore,
II, for example, a suction duct, etc. must be separately provided to prevent toner particles scattered by the rotation of the magnetic brush from entering an adjacent pond-colored developing device.

On the other hand, in the latter configuration, there is a problem in replenishing toner to each imager. That is, in the past, the toner replenishing device was arranged at a position independent of the rotary body, and the toner for each color was supplied from the toner tank of the replenishing device to a predetermined position close to the shaft end of the rotary body via a tube or the like. The supply port is extended. On the other hand, the shaft of the rotating body is hollow, and a replenishment socket for each color is provided at the end of the shaft, which communicates with each developing device through this hollow part. The toner can be replenished only when the toner is positioned in line with the replenishment port. In this way, in the conventional configuration, it is not possible to replenish toner at an arbitrary position, and before replenishing toner, the rotary body must be moved so that the replenishment socket of the color developer is located at the replenishment port of the same color. It has to be rotated, which is not very efficient.

Furthermore, although the space for arranging the developing device can be reduced, the rotating body can be used to change the color from yellow to black even in cases where not all the developing devices need to be used, such as in the case of two- or three-color printing. The developing device rotates intermittently in one direction and stops for each developing device in the order in which it is arranged, which is not efficient in terms of time.

The present invention has been made in view of the above problems, and is currently available at @i!
The space required for the placement of the equipment can be reduced,
To provide a color image forming device in a simple form that allows toner replenishment in *i and is time efficient for switching developing devices.

[Means for Solving the Problems] In order to solve the above problems, a color image forming apparatus according to the present invention has an IJi imager unit by arranging a plurality of developing devices containing colored toners of different colors adjacently in a fan shape. grooved,
The present invention is characterized in that the developing device unit is configured to be able to be reciprocated in the angular direction at the base so that a selected one of the plurality of developing devices can be stopped at a position where it applies development to the image forming body.

[Function] By means of such means, when an image input signal specifying a color to be printed is input as an output of an electronic filing system, a CAD system, etc., an appropriate control drive section rotates the developer unit at a predetermined angle. Then, the rI imagers of colors l to 4 to be printed are sequentially transferred to the image forming body.
It is brought to an image forming position and stopped, and is applied to the surface of the image forming body to form a desired monochrome, multicolor or full color print.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a tram-shaped image forming body equipped with a photoconductor such as Se on its outer peripheral surface capable of forming an electrostatic latent image.
When activated, it rotates in the direction shown by arrow A. A charging device 2, an image exposure device 3, a developing device 1, a transfer device 6, a cleaning device 7, and an erase lamp 8 are sequentially arranged around the image forming body 1. The image forming body 1 is uniformly charged with a specific polarity by a charging device 2, for example, positive polarity when a photoconductor such as Se is used, and then is charged with a first polarity by an exposure device 3.
A latent image is formed by receiving image exposure based on an image signal corresponding to the color. This latent image is developed by a developing device containing colored toner corresponding to the image signal to form a toner image of a first color. The toner image is transferred onto a suitable transfer material P by a transfer device 6, and the surface of the image forming body after the transfer is cleaned by a cleaning device 7 and prepared for the next image formation under the action of an erase lamp 8. Next, a colored toner image of a different color is formed by the same repeated process based on an image signal of a second color different from the first color, and this toner image carries the toner image of the first color. A two-color image is formed by superimposing the two-color image on the transfer material P. 3
This step is the third step in color or full color printing.
and repeat once for the fourth color. Although not shown, in order to accurately register the toner on the transfer material P, for example,
- As with the transfer 1 ram described in Publication No. 37505, a means is provided for firmly clamping the transfer material on its circumferential surface and circulating the transfer material at a timing that precisely coincides with the movement of the image forming body. . Instead of superimposing the toner images of each color on the transfer material as described above, the toner images of each color are sequentially superimposed on the image forming body (i.e., each IMm of each color is not transferred to the transfer material), and this superposition is performed. The transfer material carrying the superimposed final color image may be configured to finally transfer the final color image onto the transfer material using a heat fixing device (not shown)! (depending on the printer, the image is transported to a pressure fixing device),
There, the toner image is fused to form a color print.

The exposure device 3 is preferably a laser beam scanner that exposes and scans a color image in the form of digital dots for each color based on digital image signals manually input from an electronic filing system or a CAD system, but it is not suitable for use with a laser beam scanner such as in a normal analog color copying machine. A configuration may also be used in which the slit exposure is performed by passing the light through a filter for each color. still,
In the former case, instead of using a digital output device such as a CAD system, the digital image signal is generated by reading the color image information of the analog original for each color using a known color separation means and a photoelectric conversion element such as a CCD, and converting the digital image signal into a nitrogen-like signal. It can also be obtained by converting to

The developing device 4 includes a plurality of developing units containing colored toners of different colors, and in this example, developing units 10 containing colored toners of yellow magenta, cyan, and black.
, 2o, :3o and 40 are arranged adjacent to each other in a fan shape to form a developing device unit}100. Developer unit}1
00 has a pair of parallel outer frames 51 (only one is shown), and the developing device io is disposed along the outer periphery between the outer frames.
, 20, 30 and 40 are provided at approximately equal intervals in the angular direction. The developing device unit 100 is provided so as to be freely reciprocally driven in an angular direction around its base 52, and a selected one of the plurality of developing devices can be stopped at a position where it applies development to the image forming body I. It is configured as follows. The developing unit 100 is reciprocated by a suitable motor via a gear set or a crank mechanism. Preferably, the motor is an instantaneous braking motor capable of forward and reverse rotation, but is not limited to this. For example, a constant speed motor that rotates in one direction is used, and an appropriate clutch is placed in the drive transmission section to turn on and off the clutch. Accordingly, a configuration may be adopted in which the drive to the developing device unit is connected and disconnected. In the example of FIG. 1, although shown schematically, the (t! By being pivotally attached to the outer frame 51 of the developing device unit 100, a motor drive is applied to the developing device unit 100. Therefore, the movement of the selected developing device to the developing operation position is controlled by the activation time of the motor. I can do it.

The operation of this fJtn unit will be described later.

The rotation range of the developing device unit is sufficient as long as it is within a range in which a standby portion 80 and the outermost developing device 40, which will be described later, can be placed at a position where the developing device is applied to the image forming body.

Developing units 0, 20, 30 and 40 have the same structure except for the color of the colored toner contained therein, one example of which is shown in FIG. 5 for developing unit IO. Developer】
0 has a casing 12 that is open at the front, and a magnetic sleeve 11 is rotatably provided in the open portion in the direction of arrow B. Is the magnetic sleeve 1 flat with the image forming body 1? It extends to the front, and a magnet assembly [3] is arranged inside it. A developer made of a mixture of yellow colored toner and a magnetic carrier is contained in the casing 12, and is adhered to and conveyed onto the sleeve 11 by the magnetic force of the magnet assembly 13. The reference numeral 14 is a scraper for removing the developer on the third 1II, the reference numeral 15 and IG are screws for transporting the developer in a direction perpendicular to the plane of the paper (respectively in the opposite direction ζ), and a screw that transports the developer between the colored toner and the magnetic carrier. Mixing is performed.The gauze of the opening of the casing j2 is relatively close to the surface of the magnetic sleeve 11, and the developer is prevented from spilling from the gap therebetween.Casing 1
A cylindrical connecting portion 17 having a replenishment port 17a for replenishing colored toner inside the casing is formed at the rear of the color toner 2, and one end of a flexible tube l8 is connected to this connecting portion 17. . As shown in FIG. 1, the other end of the tube 18 is connected to a toner tank 61 for storing yellow toner in a toner supply station 60, which is arranged independently of the developing unit 1-100. Inside the tube l8, a flexible progressive coil 19 connects the toner tank 61 to the supply port l.
It is provided continuously up to 7a. The conveying coil 19 replenishes toner into the casing 12 by operating an appropriate drive device when a toner concentration detector disposed in the developing device 10 detects that the toner concentration of the developer has fallen below a predetermined appropriate range. .

The above configuration is the same for the developing devices 20, 30, and 40, and v. As shown schematically in Figure 1, the Tl imager 2
0 is connected to a toner tank 62 that stores magenta toner, the developer 30 is connected to a toner tank 63 that stores cyan toner, and the developer 40 is connected to a toner tank 64 that stores black toner by tubes 28, 38, and 48, respectively. There is.

The sleeves IL21, 31, and 4l of each developing device are set so that when they are located at the position X for developing the image forming member 1, the gap with the image forming member 1 is the same in all developing devices. ing.

Each TlI imager is driven by a common drive motor 70 in this example.
This is done by As schematically shown in FIG. 1, the drive motor 70 is driven by a chain 71 and a subrocket 72.
, chain 73 to drive gears of electromagnetic clutches 73, 74, 75 and 76 for each developer. The driven gears of the electromagnetic clutches 73, 74, 75 and 76 are respectively connected to, for example, magnetic sleeves, screws, etc. The electromagnetic clutches 73, 74, 75, and 76 are energized to operate the corresponding developing device when it is located at the developing action position X, and are deenergized to operate the corresponding developing device when the developing device is in any other position. Keep inactive.

A standby portion 80 is provided at a position below the developing device IO of the imager unit 100, and is configured such that the standby portion 80 is located at the developing position during non-printing operation, that is, during standby. There is. The standby portion 80 is not limited to the illustrated position, and may be positioned downwardly away from the outer frame 51, for example.

In order to make it possible to stop each developing device at an accurate developing position X, a click device +190 is provided on the outer frame 5l. The click mechanism 90 has a receiving plate 9l fixed to the outer frame 51. The receiving plate 91 is the developer unit}10
It extends continuously in the circumferential direction of 0, and has recesses 9 at approximately equal intervals.
2 to 96 are formed. On the other hand, a roller 97 for positioning that is rotatable around the axis is provided so as to be movable in the direction toward and away from the surface of the receiving plate 91, and is provided with an appropriate spring in the direction of pressing the surface of the receiving plate 91. energized by means 98; When the recessed portion of the receiving plate 9l is placed in the position, a part of the circular surface of the roller 97 is sunk into the recessed portion of the receiving plate 9l.

This retraction has only a negligible braking effect when the developer unit 100 is being driven, but it is necessary to prevent overrun due to its inertia when the developer unit 100 is deenergized. It works well. As mentioned above, each of the recesses 92, 93, 94, 95, and 96 is formed in the standby portion 80 when the roller 97 is inserted therein.
, the developing devices 10, 20, 30, and 40 are accurately positioned at the developing action position x.

In order to detect that each of the developing units 10 to 40 and the standby portion 80 of the developing unit 100 are located at the developing action position X, an optical or mechanical position detection means is provided. Sends a predetermined signal to the drive control i3II section when the device or standby section is located at the JJI image effect position;
In accordance with this, the control section controls the driving of the developer unit 100 at the corresponding position if the corresponding developer is related to the color designated for printing.

Next, with reference to FIGS. 2 to 4, the above developer unit}
The operation of 100 will be explained.

When an image input signal specifying image information to be printed and color information output from an electronic filing system, CAD system, image scanner, etc. is sent to the page memory controller 200 in the image forming apparatus, the controller 200 receives this color information. Based on this, a corresponding one of a plurality of pre-stored memory sets is called, and the memory set signal is sent to the control unit 300. Control unit 300
follows this memory set signal, developing units 10, 20, 3
0 and 40 are moved to the developing action position on the image forming body in the order according to the information. In Figure 4, the developing device is in the waiting area 8.
The correspondence between the memory set k' stored in the page memory controller 2oo and the order of use of the developing units (developing order) is shown in the case where they are arranged in the order of 0, yellow, magenta, cyan, and black. For example, if the color information specifies all colors (full color), memory set}1 is called and fJl! The jt device unit 100 selects the number in the development drive order by the control section 300. According to the pattern No. 1, the developing devices are moved to the side closer to the standby portion 80, that is, the yellow magenta, cyan, and black developing devices are moved to act on the image forming body in this order. The developing unit L-100, whose standby portion 80 faced the developing position X, is moved clockwise as seen in FIG. When the developing device 10 is located at the developing position X, the motor is deenergized and the positioning roller 97 enters the recess 93 of the receiving plate 90 and stops at an accurate position.

Around this time, the N magnetic clutch 73 is energized and the sleeve l
1 rotates to apply yellow toner to the image forming body. On the other hand, a latent image is formed on the image forming body according to image information (page memory) corresponding to yellow, and the latent image is developed by the developing device 10 to form a yellow toner image. Unit 100 is magenta Tyt imager 2
0 is located at the developing action position X. At this time, the electromagnetic clutch 73 of the yellow developing device 10 is deenergized and the sleeve l1 is stopped. The sleeve 2l of the developing device 20 stopped at the developing position X is rotated by the urging of the electromagnetic clutch, and the latent image formed on the image forming body corresponding to magenta is developed to form a magenta image. Similar movements and operations are performed for the cyan and black developers to form toner images of the respective colors. As described above, this toner image is superimposed on a transfer material or on an image forming body to form a full-color image. TJt
A motor 70 for driving the fl unit is energized at appropriate timing with the print signal, and is deenergized after printing is completed. When multiple copies of the same image are printed, the developer unit 100 is replaced by the yellow developer unit 10 again.
is moved to the developing position. When all necessary development has been completed, the developer unit 100 returns to its standby portion 80 in the development position X and waits for the next image to be produced. Similarly, when the color information of the image input signal indicates only magenta and black, memory set 8 is called;
The specified developer is pattern no. It moves and stops in the order of 8 and acts on the image forming body. In this case, the movement and stopping of the unspecified yellow and cyan TJi imagers to the developing action position the color is carried to the developing position, and the color is developed;
Then, after operation, the black developer is brought to the developing position, ignoring the cyan. Similarly, when the giant information specifies magenta and cyan, memory set 7 is called up, and when it specifies cyan and black, memory set 9 is called out.

An example of a flowchart of such a memory set call is shown in FIG.

The images thus formed in the designated colors are superimposed to form a monochrome, multicolor, or full color print.

[Effects of the Invention] As described above, according to the present invention, since the developing units are arranged adjacently in a fan shape, the space for the developing unit H can be reduced, and the developing unit can be reciprocated within a narrow angle range. Because of this structure, the time efficiency for switching the developing device is good. Furthermore, by making it fan-shaped so that it can reciprocate within a predetermined angle range, the rear side of the developer can be directly connected to the toner supply device through a flexible tube. Even if there is a problem, toner can be replenished at any time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the main parts of a color image forming apparatus according to the present invention, FIG. 2 is a block diagram of a print control section, FIG. 3 is a flowchart of a page memory controller, and FIG. 4 is an example of a memory set signal. FIG. 5 is a sectional view showing an example of a developing device. 1... Image forming body, 3... Image exposure device, lO
, 20, 30, 40...Developer, 1 8, 28,
38, 48... Flexible tube, 60... Toner supply device, 61, 62, 63, 64... Toner tank, 80...
- Standby portion, 90...Click mechanism, 100...Developer unit 1, 200...Page memory controller, 300...
control section.

Claims (1)

[Claims] A developing device unit is constructed by arranging a plurality of developing devices containing colored toners of different colors adjacent to each other in a fan shape, and this developing device unit is reciprocally driven in an angular direction at a base, and a selected one of the plurality of developing devices is arranged adjacently in a fan shape. A color image forming apparatus characterized in that one of the parts is configured such that it can be stopped at a position where development is applied to an image forming member.