JP2003107914A - Printing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miniaturized printing machine which can obtain a high quality printed matter at a lower cost. SOLUTION: The printing machine 1 is provided with a photoreceptor drum 2, an electrifying device 3, an exposing device 4, a developing means 19 to develop the electrostatic latent image on the surface of the photoreceptor drum 2, a transfer roll, and a backup roll. The developing means 19 is provided with the main body 5 of a developing machine in which a plurality of development units 5B to 5E are juxtaposed, a developing machine moving mechanism to horizontally move the main body 5, and storage tanks 75B to 75E to store liquid toner. Each development unit 5B to 5E comprises toner storage chambers 61B to 61E, developing rollers 62B to 62E, and pumps 69B to 69E to feed the liquid toner in the storage tanks 75B to 75E to the toner storage chambers 61B to 61E. The storage tanks 75B to 75E are provided at least over the whole region within the moving range of the intake of the pumps 69B to 69E.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing machine for transferring an image formed on a photoconductor using an electronic technique to an intermediate transfer medium and further transferring the image from the intermediate transfer medium to an output medium such as printing paper. Regarding

[0002]

BACKGROUND ART Conventionally, as shown in FIG. 7, liquid toner is supplied to the surface of a photosensitive drum 102 which rotates at a constant speed to form an image, and the transfer roller 1 is transferred to the photosensitive drum 102.
After the image is transferred to the transfer roller 106 by rotating the transfer roller 106 while contacting it, the print paper W is sandwiched between the transfer roller 106 and the backup roller 107, and the transfer roller 106 and the backup roller 107 are rotated to transfer the image. A printing machine 100 that transfers an image on a roller 106 onto a printing paper W is known.

Such a printing machine 100 includes a charger 103 for charging the surface of a photosensitive drum 102 having photosensitivity,
Photosensitive drum 102 charged by the charger 103
And an exposing device 104 that creates an electrostatic latent image by performing an exposure scan on the basis of drawing data, and develops the electrostatic latent image on the surface of the photosensitive drum 102 created by the exposing device 104 by supplying liquid toner. And a developing machine 105.

The developing machine 105 includes a base 105A and four developing units 105B, 105 arranged in parallel on the base 105A and containing four process colors.
C, 105D, 105E. Each of the developing units 105B to 105E includes a toner storage chamber 161B, 161C, 161D, 161E in which liquid toner is stored,
The developing rollers 162B, 162C, 162D, 162E provided in the toner storage chambers 161B to 161E, and storage tanks 175B, 175C for storing liquid toner,
175D and 175E and the storage tanks 175B to 17
5E to liquid toner from toner storage chambers 161B to 161E
Pumps 169B, 169C, 169D for pumping to the lower part,
169E and. The liquid toner has electrical characteristics such that it is charged positively or negatively after a resin and a pigment are mixed in a solvent.

The developing rollers 162B to 162E supply the liquid toner in the toner storage chambers 161B to 161E to the photosensitive drum 102, and the lower surface thereof is immersed in the liquid toner.

Further, the developing device 105 includes the photosensitive drum 10
When any one of the developing units 105B to 105E is selected corresponding to each color electrostatic latent image formed on the second developing unit 105, the developing machine 105 is horizontally moved to move the developing unit 105B to 105E of the selected developing unit 105B to 105E. Developing rollers 162B-16
2E is a position immediately below the photosensitive drum 102, that is, a position separated from the lowermost surface of the photosensitive drum 2 by a predetermined distance (hereinafter,
It is located at the developing position). Note that, in FIG. 7, the developing roller 62B is drawn so as to be largely separated from the photoconductor drum 102, but in reality, the developing roller 162 is actually used.
A slight gap is formed between B and the photosensitive drum 102.

In this state, the developing roller 1 at the developing position
62B is rotationally driven. Then, the developing roller 162B
Of the liquid toner in the toner storage chamber 161B,
The liquid toner near the upper liquid surface adheres to the developing roller 162B and is carried, and approaches the photosensitive drum 102. Since this liquid toner has electrical characteristics, it is attracted and moved by the electrostatic latent image on the photoconductor drum 102, which also has electrical characteristics (this is called electrophoresis), and electrostatic An image is formed by electrostatically adhering to the latent image. Also, the developing roller 1
By supplying the liquid toner to the photosensitive drum 102 at 62B, the amount of liquid toner in the toner storage chamber 161B decreases, but the reduced amount is appropriately replenished from the storage tank 175B to the toner storage chamber 161B by the pump 169B. .

[0008]

By the way, the developing machine 10
5 is moved horizontally, the developing units 105B to 105
Since the storage tanks 175B to 175E forming E also move horizontally, the weight of the movable portion becomes large, a large drive device is required, and the printing machine becomes large. Further, when performing high-speed printing, the inertial force increases due to the large weight of the movable portion, and it becomes difficult to position the developing units 105B to 105E at the developing position, which may deteriorate the quality of the printed matter.

Therefore, in order to solve this problem, the storage tanks 175B to 175E are fixed to the printing machine 100, and both ends of the flexible hose are stored in the storage tanks 175B to 175.
E and the toner storage chambers 161B to 161E,
A liquid toner storage tank 175B-1
A method of supplying from 75E to the toner storage chambers 161B to 161E can be considered. However, in this method, since the toner storage chambers 161B to 161E move horizontally, it is necessary to set the length of the hose to a length corresponding to the moving range of the toner storage chambers 161B to 161E. Therefore, the hose is liable to be entangled, and it becomes a resistance when the developing device 105 moves, which may change the moving speed of the developing device 105 and deteriorate the quality of the printed matter. Further, it takes time and effort to clean the hose during cleaning, which may increase the printing cost.

An object of the present invention is to provide a printing machine which can be miniaturized and can obtain high-quality printed matter at low cost.

[0011]

In order to achieve the above object, the printing machine of the present invention adopts the following constitution. Claim 1
The printing machine described in 1 above, a photoconductor, a charging unit that charges the surface of the photoconductor, an exposure unit that forms an electrostatic latent image by exposing the surface of the photoconductor charged by the charging unit, Developing means for developing the electrostatic latent image by electrophoretically supplying liquid toner to the surface of the photoreceptor exposed by the exposing means, and transfer for transferring the image on the photoreceptor developed by the developing means. In a printing machine including a body and a backup body that transfers the image transferred to the transfer body onto an output medium, the developing means includes a plurality of developing units in which liquid toners of respective colors are accommodated. The main body, a developing machine moving mechanism for horizontally moving the developing machine main body in the direction of juxtaposition of the developing units to position each developing unit at the developing position of the photoconductor, and liquid toner of each color is stored. And a holding tank to be, the developing unit includes a toner accommodating chamber liquid toner is accommodated,
The toner storage chamber is provided with a developing roller that supplies the liquid toner to the photoconductor, and a supply unit that supplies the liquid toner in the storage tank to the toner storage chamber. It is characterized in that it is provided over at least the entire moving range of the inlet of the supply means.

According to the present invention, by horizontally moving the developing machine main body, the developing units of respective colors are appropriately positioned at the developing positions of the photoconductors, and the liquid toner contained in the toner accommodating chamber of each developing unit is developed. To develop the electrostatic latent image. At this time, since the storage tank is provided at least over the entire moving range of the intake port of the supply unit, while the supply unit is moved together with the developing device main body, the liquid toner in the storage tank is reliably taken in by the intake port, It can be supplied to the toner storage chamber. Therefore, since the storage tank does not move together with the main body of the developing machine, a large driving device is unnecessary, and the printing machine can be downsized. Also,
Since the movable part can be made small, the developing unit can be easily positioned, and a high-quality printed matter can be obtained. Further, since the supply means can be downsized, the moving speed of the developing machine can be made constant, a high-quality printed matter can be obtained, and since the labor of the supply means is not required, the printing cost can be reduced.

According to a second aspect of the present invention, in the printing machine according to the first aspect, the developing unit includes a collected toner storage chamber in which liquid toner is stored, and the photosensitive toner provided in the collected toner storage chamber. A fogging roller that collects the excess liquid toner that is attached to the surface of the body by attaching it to the surface,
Ejecting means for ejecting the liquid toner in the collected toner accommodating chamber to the accommodating tank, wherein the accommodating tank is provided at least over the entire movement range of the outlet of the ejecting means.

According to the present invention, excess liquid toner on the surface of the photoconductor is collected by the fogging roller and stored in the collected toner storage chamber, and then discharged to the storage tank by the discharge means. At this time, since the storage tank is provided at least over the entire movement range of the discharge port of the discharging unit, the liquid toner in the recovery toner storage chamber is surely stored from the discharge port while moving the discharging unit together with the developing device main body. Can be discharged to. Therefore, since the liquid toner can be reused, the usage amount of the liquid toner can be saved.

According to a third aspect of the present invention, in the printing machine according to the second aspect, the supplying means is a pump and the discharging means is a pipe provided in the collected toner storage chamber. At least one of the inlet of the pump and the outlet of the pipe extends to the vicinity of the bottom surface of the storage tank. According to the present invention, when the developing device main body is horizontally moved, at least one of the intake port of the pump and the discharge port of the pipe moves in the liquid toner of the storage tank, so that the liquid toner in the storage tank is As a result of stirring, the concentration of the liquid toner is made uniform. Therefore, since the liquid toner having a constant concentration can be supplied to the photoconductor, the print quality can be made constant. Further, since the supply means is a pump and the discharge means is a pipe, the liquid toner in the storage tank can be supplied to the toner storage chamber and the liquid toner in the recovery toner storage chamber can be discharged to the storage tank with a simple structure. The manufacturing cost of the printing machine can be reduced.

According to a fourth aspect of the present invention, in the printing machine according to the second or third aspect, the storage tank is provided only in the moving range of the inlet of the supply means and the outlet of the discharge means. It is characterized by According to the present invention, since the storage tank can be made to have a necessary minimum size, the printing machine can be further downsized.

A printing machine according to a fifth aspect is the printing machine according to any one of the second to fourth aspects, wherein the storage tank is located below the developing machine and the developing machine is provided on the upper surface thereof. It is characterized in that it has an opening through which the supply means and the discharge means pass, and is provided with a retractable accommodating tank cover that covers the portion of this opening that is not covered by the developing machine. According to the present invention, since the opening of the storage tank is surely covered with the developing device or the storage tank cover, it is possible to prevent dust from entering the storage tank, and to supply high-purity liquid toner to the photoconductor to enhance the toner. Quality printed matter can be obtained.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall view of a printing machine 1 according to an embodiment of the present invention. The printing machine 1 prints by image-on-image in which drawing data created based on print image data is sequentially overlapped with colors such as yellow, magenta, cyan, and black to form an image.

The printing machine 1 serves as a transfer member to which the image is transferred by rotating the photosensitive drum 2 as a photosensitive member on which an image is formed, while contacting the photosensitive drum 2 with an elastic surface. A transfer roller 6 and a backup roller 7 as a backup member for transferring an image transferred to the transfer roller 6 to the print paper W by rotating by sandwiching a print paper W as an output medium between the transfer roller 6 and the transfer roller 6; Is equipped with.

The transfer roller 6 is provided above the photosensitive drum 2, and is formed by winding an elastic rubber blanket 6B around the outer circumference of the iron core 6A. The rubber blanket 6B is tensioned by being pulled with a predetermined tension, and the image on the surface of the photosensitive drum 2 is pressure-transferred. The backup roller 7 is provided above the transfer roller 6 and applies a strong printing pressure to the transfer roller 6 with the printing paper W interposed therebetween.

The photosensitive drum 2, the transfer roller 6 and the backup roller 7 have independent and independent driving sources. That is, the photosensitive drum 2 is provided with a first servo motor 8, the transfer roller 6 is provided with a second servo motor 9, and the backup roller 7 is provided with a third servo motor 10, and these servo motors 8, 9, 10 are provided. The driving is controlled by the control means 20 provided inside the printing press 1.

Further, in the vicinity of the periphery of the photosensitive drum 2, a charger 3 as a charging means for applying an electric charge to the photosensitive drum 2, and the photosensitive drum 2 charged by the charger 3.
Is exposed to light for a certain period of time to form an electrostatic latent image on the photoconductor drum 2, and an electrostatic latent image on the photoconductor drum 2 formed by being exposed by the exposure device 4 is exposed. A developing means 19 for developing by supplying liquid toner is provided in order.

The developing means 19 includes a developing device main body 5 for accommodating toner of each color, a developing roller driving motor 17, a developing device moving mechanism 12, accommodating tanks 75B, 75C, 75D.
And 75E. The developing device main body 5 includes a base 5A,
Four developing units 5 arranged side by side on this base 5A
B, 5C, 5D, and 5E.

2 is a plan view of the developing units 5B to 5E, and FIG. 3 is a sectional view taken along line III-III of FIG. The developing unit 5B stores the first color liquid toner of the four process colors, for example, yellow liquid toner, and the developing unit 5C stores the second color liquid color of the four process colors, for example, red liquid toner. The developing unit 5D stores a liquid toner of the third color of the four process colors, for example, indigo, and the developing unit 5E stores the fourth color of the four process colors of, for example, black. Liquid toner is stored.
The liquid toner is provided with electrical characteristics such that it is positively or negatively charged after a resin and a pigment are mixed in a solvent.

Each of the developing units 5B-5E includes a toner storage chamber 61B, 61C, 61D, 61E, a recovery toner storage chamber 66B, 66C, 66D, 66E, a flow passage 74B, and a flow path 74B.
74C, 74D, 74E and developing rollers 62B, 62
C, 62D, 62E, and fogging removal rollers 67B, 67
C, 67D, 67E and diaphragm blades 68B, 68C,
68D, 68E and pumps 69B, 6 as a supply means
9C, 69D, 69E, and a pipe 63B as a discharging means,
It has 63C, 63D, and 63E.

FIG. 4 shows an enlarged perspective view of the developing units 5B-5E. The toner storage chambers 61B to 61E and the collected toner storage chambers 66B to 66E each store liquid toner, and have a bottom surface 7 having a quadrangular plane shape.
1 and four wall surfaces 72A, 72B, 72C, 72D having a height H1 that are erected around the bottom surface 71 and partition the container 70 with a height H2 lower than the height H1 of the wall surface 72A. It is formed by partitioning with a plate 73.

The flow paths 74B to 74E are provided in the toner storage chamber 61.
Liquid toner in B to 61E is collected in the toner storage chamber 66B to
It supplies to the contact points of the diaphragm blades 68B to 68E of 66E and the fog removing rollers 67B to 67E. The flow paths 74B to 74E are formed by an inclined surface 77 that descends from the upper end of the partition plate 73 of the container 70 toward the surface of the fog removing rollers 67B to 67E, and the liquid toner is stored in the toner storage chambers 61B to 61B.
From 61E to the collected toner storage chambers 66B to 66E. That is, the inflow ports of the flow paths 74B to 74E are located above the toner storage chambers 61B to 61E, and the flow paths 74B to 7E.
The outlet of 4E is close to the surface of the fog removing rollers 67B to 67E. Further, the liquid level of the liquid toner in the toner storage chambers 61B to 61E is in a state of reaching the inflow ports of the flow paths 74B to 74E.

Referring back to FIGS. 2 and 3, the developing roller 62
B to 62E are for supplying the liquid toner in the toner storage chambers 61B to 61E to the photosensitive drum 2, and are provided above the toner storage chambers 61B to 61E so that their lower surfaces are immersed in the liquid toner. Fogging rollers 67B-6
7E collects the liquid toner excessively attached to the surface of the photoconductor drum 2 by attaching it to the surface, and is provided above the collected toner storage chambers 66B to 66E.

The diaphragm blades 68B to 68E come into contact with the surfaces of the fog removing rollers 67B to 67E,
The liquid toner attached to the fogging rollers 67B to 67E is scraped and collected in the collected toner storage chambers 66B to 66E, and is provided in the collected toner storage chambers 66B to 66E. That is, the diaphragm blades 68B to 68E
Is in contact with the fog removing rollers 67B to 67E below the fog removing rollers 67B to 67E and within a range where the liquid toner flowing from the flow paths 74B to 74E reaches. Here, it is provided on the lower side of the fog removing rollers 67B to 67E near the rotational direction.

The pumps 69B to 69E are the storage tank 75.
The liquid toner in B to 75E is transferred to the toner storage chambers 61B to 61B.
It supplies to E. The pumps 69B to 69E are provided below the toner storage chambers 61B to 61E, and their intake ports extend to the vicinity of the bottom surfaces of the storage tanks 75B to 75E. The tubes 63B to 63E are provided in the collected toner storage chamber 66.
Tanks 75B to 75E for accommodating liquid toner in B to 66E
To be discharged to. The tubes 63B to 63E are provided below the collected toner storage chambers 66B to 66E, and the discharge ports thereof extend to the vicinity of the bottom surfaces of the storage tanks 75B to 75E.

The storage tanks 75B to 75E store liquid toner. The storage tanks 75B to 75E are
Under the base 5A of the developing machine main body 5, the developing units 5B-5
E is installed in a direction orthogonal to the direction in which E is installed, and the intake ports and the pipe 63B of the corresponding pumps 69B to 69E are arranged.
It is provided over the entire moving range of the discharge port of 63E. The storage tanks 75B to 75E have openings 76B, 76C, 76D, and 76E for moving the pumps 69B to 69E and the tubes 63B to 63E of the developing machine on the upper surface thereof.
A retractable storage tank cover 78 that covers the portions of the openings 76B to 76E that are not covered by the base 5A of the developing machine 5.
B, 78C, 78D, 78E are provided.

Returning to FIG. 1, the developing roller drive motor 17
Is connected to the developing rollers 62B to 62E and the fog removing rollers 67B to 67E.
62E and the fog removing rollers 67B to 67E are rotationally driven. Specifically, the developing roller drive motor 17 rotates the developing rollers 62B to 62E so that the rotation direction of the surface thereof is the same as the rotation direction of the surface of the photosensitive drum 2. That is, in FIG. 1, the photosensitive drum 2 rotates clockwise and the developing roller 62B rotates counterclockwise. Further, the developing roller drive motor 17
Rotates the fog removing rollers 67B to 67E so that the rotation direction of the surface thereof is opposite to the rotation direction of the surface of the photosensitive drum 2. That is, in FIG. 1, the fog removing rollers 67B to 67E are rotating clockwise.

The developing machine moving mechanism 12 is connected to the developing machine moving motor 11, and drives the developing machine moving motor 11 to horizontally move the developing machine body 5 in the direction in which the developing units 5B to 5E are arranged in parallel. That is, when any one of the developing units 5B to 5E is selected corresponding to each color electrostatic latent image formed on the photoconductor drum 2, the developing machine moving motor 11 is selected.
By this, the developing rollers 62B to 62E of the selected developing units 5B to 5E are positioned substantially below the photosensitive drum 2, that is, at the developing position separated from the lowermost surface of the photosensitive drum 2 by a predetermined distance. At this time, each developing roller 6
2B to 62E corresponding fog removing rollers 67B to 6
7E is also located at the developing position of the photoconductor drum 2 like the developing rollers 62B to 62E.

Here, the developing unit 5B is selected, and the developing roller 62B and the fog removing roller 67B are selected.
Is located at the developing position of the photosensitive drum 2. In addition,
In FIG. 1, the developing roller 62B and the fog removing roller 6 are
7B is drawn so as to be largely separated from the photosensitive drum 2, but in reality, a slight gap is formed between the developing roller 62B and the fogging roller 67B and the photosensitive drum 2. Above pumps 69B-69
E, the developing roller drive motor 17 and the developing machine moving motor 11 are controlled by the control means 20.

The printing paper W is supplied between a backup roller 7 and the transfer roller 6 by a paper conveying actuator (not shown), and the image on the transfer roller 6 is transferred by pressure.

FIG. 5 shows a block diagram of the control means 20 of the printing press 1 as described above. The control means 20 is
The drawing data creation unit 25, the exposure control unit 36 that controls the exposure unit 4, the process control unit 35 as a control unit, and the phase synchronization control unit 40 that controls each servo motor 8, 9, 10.
It has and.

The drawing data creating section 25 creates drawing data based on the print image data created separately. Here, the print image data used by the drawing data creation unit 25 is, for example, a DTP (desktop publ) that is edited by incorporating characters, figures, photographs, etc., using a small computer system such as a personal computer or a workstation.
ishing) system, PS file,
PDF (Portable Document Format) file, TIF
F (Tagged Image File Format) is output in a format such as a file. Therefore, the drawing data creation unit 25 has a function corresponding to each file format, and creates the drawing data using this function. 4 color separation processing, R
The IP (Raster Image Processor) processing and the like are also performed by the drawing data creation unit 25 corresponding to the file format.

The exposure control section 36 includes a drawing data creating section 25.
The drawing data created in step 1 is converted into a signal (exposure signal) for driving the exposure device 4 and output to the exposure device 4. The process control unit 35 controls the charger 3, the developing device driving motor 17, and the developing device moving motor 11 to execute the printing process, and intermittently drives the pumps 69B to 69E at predetermined intervals. The phase synchronization control unit 40 uses the software synchronization to synchronize the photosensitive drum 2, the transfer roller 6,
The servo motors 8, 9 and 10 are controlled so as to maintain the synchronization of the backup roller 7.

FIG. 6 shows flowcharts ST1 to ST17 of the processing of the printing press 1 according to this embodiment.
First, in step (hereinafter referred to as ST) 1, the distance between the developing rollers 62B to 62E and the photoconductor drum 2 is set to a predetermined dimension, and in step ST2, the photoconductor drum 2 is rotated and the charger 3 is turned on. As a result, the photosensitive drum 2 is charged. Next, in ST3, the exposure device 4 draws a first color. That is, the drawing data creation unit 25 creates drawing data based on the image information, and the exposure control unit 36 controls the exposure unit 4 based on the drawing data, whereby the electrostatic latent image is formed on the photosensitive drum 2. To form.

At ST4, the liquid toner of the first color is moved from the developing unit 5B for the first color onto the electrostatic latent image to develop the electrostatic latent image on the photosensitive drum 2. Specifically, the developing roller 62B is driven to rotate, and among the liquid toners in the toner containing chamber 61B, the liquid toner near the liquid surface above the toner containing chamber 61B is attached to the developing roller 62B and carried to the photoconductor. Approach drum 2. Then, since this liquid toner has electrical characteristics, it is pulled and moved by the electrostatic latent image on the photoconductor drum 2 having the same electrical characteristics (this is called electrophoresis), An electrostatic latent image is electrostatically attracted to form an image.

At the same time, the fog removing roller 67B is rotationally driven, and the liquid toner excessively attached to the surface of the photosensitive drum 2 adheres to the surface of the fog removing roller 67B.
Thereafter, this liquid toner is scraped off by the diaphragm blade 68B and falls, and is collected in the collected toner storage chamber 66B. The collected liquid toner is stored in the storage tank 75B through the pipe 63B.

In the developing units 5C to 5E for the second to fourth colors, the developing rollers 62C to 62E and the fog removing rollers 67C to 67E are not rotationally driven. At this time, the liquid level of the liquid toner in the toner storage chambers 61C to 61E is in a state of reaching the inflow port of the flow paths 74C to 74E, that is, a full state. In this state, the pumps 69C to 69E are intermittently driven to move the toner storage chambers 61C to 61E from the storage tanks 75C to 75E.
Liquid toner is sent to the bottom. Then, the sent liquid toner causes the liquid toner already in the toner storage chambers 61C to 61E to flow and be pushed upward, and as a result, the liquid toner in the vicinity of the inlets of the flow channels 74C to 74E is flow channel 74C. ~ 74E overflow, this flow path 74C ~ 74E
To reach the surface of the fog removing rollers 67C to 67E. Then, the liquid toner is transferred to the fog removing roller 67.
C-67E Along the surface, diaphragm blades 68C-68E
It passes through the contact points with the surfaces of the fog removing rollers 67C to 67E, falls into the collected toner containing chambers 66C to 66E, and flows down into the containing tanks 75C to 75E. By repeating the above operation, the liquid toner is collected in the collected toner storage chamber 6
6C to 66E, the storage tanks 75C to 75E, and the toner storage chambers 61C to 61E are circulated intermittently,
As a result, the liquid toner intermittently flows to the contact points between the diaphragm blades 68C to 68E and the surfaces of the fog removing rollers 67C to 67E.

After the development of the first color is completed, in ST5, 2
To develop the color, move the developing machine main body 5 horizontally and
The color developing unit 5C is positioned at the developing position. Subsequently, in ST6, the exposure device 4 starts drawing the second color.
Thereafter, similarly, the second color is developed in ST7, the developing machine main body 5 is moved in ST8, the third color is drawn in ST9, the third color is developed in ST10, and the developing machine main body 5 is moved in ST11.
The fourth color is drawn at T12, and the fourth color is developed at ST13.

Until ST13 described above, the transfer roller 6 is not in contact with the photosensitive drum 2, and after the development of the fourth color is completed, the transfer roller 6 is mounted on the photosensitive drum 2 in ST14. Then, the backup roller 7 is attached to the transfer roller 6. Subsequently, in ST16, the image on the photoconductor drum 2 is transferred to the transfer roller 6 by rotating the transfer roller 6 while contacting the photoconductor drum 2.

Further, in ST17, the backup roller 7 is rotated while being in contact with the transfer roller 6, so that the image transferred to the transfer roller 6 is transferred to the printing paper W. As described above, a full-color printed image is formed on the photosensitive drum 2 by the image-on-image.

Therefore, according to this embodiment, the following effects are obtained. (1) Pump the storage tanks 75B-75E to pumps 69B-69
Since the intake port of E is provided over the entire moving range, the liquid toner in the storage tanks 75B to 75E is reliably taken in by the intake port while moving the pumps 69B to 69E together with the developing device main body 5 to store the toner. Room 61B ~
Can be supplied to the 61E. Therefore, the storage tanks 75B to 75
Since E does not move together with the developing device main body 5, a large driving device is unnecessary and the printing machine 1 can be downsized. Moreover, since the movable portion can be made small, the developing units 5B to 5E can be easily positioned, and a high-quality printed matter can be obtained. Further, since the pumps 69B to 69E can be miniaturized, the moving speed of the developing device 5 can be made constant, high quality printed matter can be obtained, and the pumps 69B to 69E can be obtained.
Since the cleaning work of E is not required, the printing cost can be reduced.

(2) Since the storage tanks 75B to 75E are provided at least over the entire moving range of the discharge ports of the pipes 63B to 63E, the pipes 63B to 63E are moved together with the developing device main body 5 and recovered from the discharge ports. Toner storage chamber 66
Reservoir 75B for securely storing liquid toner in B to 66E
Can be discharged to 75E. Therefore, since the liquid toner can be reused, the usage amount of the liquid toner can be saved.

(3) The inlets of the pumps 69B to 69E and the outlets of the pipes 63B to 63E are connected to the storage tank 75B.
Since the developing device main body 5 is horizontally moved, the intake ports of the pumps 69B to 69E and the discharge ports of the pipes 63B to 63E are accommodated in the storage tank 75B.
Since it moves in the liquid toner of ~ 75E, the storage tank 7
The liquid toner in 5B to 75E is agitated,
The concentration of the liquid toner is made uniform. Therefore, since the liquid toner having a constant concentration can be supplied to the photosensitive drum 2, the print quality can be made constant.

(4) Pumps 69B to 69E and pipe 63
Since B to 63E are provided, the storage tank 7 has a simple structure.
The liquid toner in 5B to 75E is stored in the toner storage chambers 61B to 6B.
1E, and the collected toner storage chambers 66B to 66B
Since the liquid toner in 6E can be discharged to the storage tanks 75B to 75E, the manufacturing cost of the printing machine 1 can be reduced.

(5) The storage tanks 75B to 75E are connected to the intake ports of the pumps 69B to 69E and the pipes 63B to 63E.
Since it is provided only in the moving range of the discharge port of
Since B to 75E can be set to the minimum required size, the printing machine 1 can be further downsized.

(6) The storage tanks 75B to 75E are positioned below the base 5A of the developing machine 5, and a pump 69B is provided on the upper surface thereof.
~ 69E and tubes 63B-63E are provided with openings 76B-76E for moving, and since expandable storage tank covers 78B-78E are provided for covering the portions of the openings 76B-76E that are not covered by the base 5A, Storage tank 75B
Since the openings 76B to 76E of ~ 75E are surely covered by the base 5A or the storage tank covers 78B to 78E, it is possible to prevent dust from entering the storage tanks 75B to 75E, and the high-purity liquid toner is applied to the photoconductor. It can be supplied to obtain high quality printed matter.

The present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.

[0053]

According to the printing machine of the present invention, the following effects can be obtained. While moving the supply means together with the developing device main body, the liquid toner in the storage tank can be reliably taken in by the intake port and supplied to the toner storage chamber. Therefore, since the storage tank does not move together with the developing machine main body,
A large driving device is unnecessary, and the printing machine can be downsized.
Further, since the movable portion can be made small, the developing unit can be easily positioned, and a high quality printed matter can be obtained. Further, since the supply means can be downsized, the moving speed of the developing machine can be made constant, a high-quality printed matter can be obtained, and since the labor of the supply means is not required, the printing cost can be reduced.

[Brief description of drawings]

FIG. 1 is an overall view showing a printing machine according to an embodiment of the present invention.

FIG. 2 is a plan view of a developing unit of the printing machine according to the embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged perspective view of a developing unit of the printing machine according to the embodiment.

FIG. 5 is a block diagram showing a control system of the printing machine according to the embodiment.

FIG. 6 is a flowchart of a process of the printing machine according to the embodiment.

FIG. 7 is a schematic view showing a printing machine according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Printer 2 Photoconductor drum 3 as a photoconductor 3 Charger 4 as a charging means 4 Exposure device 5 as an exposure means Developing machine main body 5B, 5C, 5D, 5E Developing unit 6 Transfer roller 7 as a transfer body 7 As a backup body Backup roller 12 Developing device moving mechanism 19 Developing means 61B, 61C, 61D, 61E Toner storage chambers 62B, 62C, 62D, 62E Developing rollers 63B, 63C, 63D, 63E Pipes 66B, 66C, 66D, 66E as discharging means Collected toner Storage chambers 67B, 67C, 67D, 67E Fogging rollers 69B, 69C, 69D, 69E Pumps 75B, 75C, 75D, 75E as supply means Storage tanks 76B, 76C, 76D, 76E Storage tank openings 78B, 78C, 78D, 78E accommodation tank cover W as an output medium Printing paper

Continued front page    F term (reference) 2H030 AA05 AD01 BB24 BB27 BB33                       BB38 BB43 BB46 BB71                 2H074 AA03 BB02 BB06 BB08 BB32                       BB43 BB54 BB60 BB72 EE07

Claims (5)

[Claims] 1. A photoconductor, a charging means for charging the surface of the photoconductor, and an exposing means for forming an electrostatic latent image by exposing the surface of the photoconductor charged by the charging means.
Developing means for developing the electrostatic latent image by electrophoretically supplying liquid toner to the surface of the photoreceptor exposed by the exposing means, and an image on the photoreceptor developed by the developing means are transferred. In a printing machine provided with a transfer body and a backup body for transferring an image transferred to the transfer body onto an output medium, the developing means includes a developing unit in which a plurality of developing units accommodating liquid toners of respective colors are arranged in parallel. A main body of the machine, a developing machine moving mechanism for horizontally moving the main body of the developing machine in the direction of juxtaposition of the developing units to position each of the developing units at a developing position of the photoconductor, and a liquid toner of each color are accommodated. Each developing unit includes a toner storage chamber that stores liquid toner, and a developing roller that is provided in the toner storage chamber and supplies the liquid toner to the photoconductor. And a supply means for supplying the liquid toner in the storage tank to the toner storage chamber. The storage tank is provided at least over the entire moving range of the intake port of the supply means. A printing machine characterized by that. 2. The printing machine according to claim 1, wherein the developing unit has a recovery toner storage chamber in which liquid toner is stored, and the development unit is excessively attached to the surface of the photoconductor provided in the recovery toner storage chamber. A fogging roller that collects the liquid toner by adhering it to the surface and a discharging unit that discharges the liquid toner in the collected toner storage chamber to the storage tank are provided, and the storage tank moves at least the discharge port of the discharge unit. A printing machine characterized by being provided over the entire range. 3. The printing machine according to claim 2, wherein the supply unit is a pump, and the discharge unit is a pipe provided in the collected toner storage chamber, and an intake port of these pumps and At least one of the outlets of the pipe extends to near the bottom surface of the storage tank. 4. The printing machine according to claim 2, wherein the storage tank is provided only in a moving range of the intake port of the supply unit and the discharge port of the discharge unit. Machine. 5. The printing machine according to claim 2, wherein the storage tank is located below the developing machine, and the supply means and the discharge means of the developing machine pass through the upper surface thereof. And a retractable storage tank cover for covering a portion of the opening not covered by the developing machine.