CN1105337C - Development apparatus for liquid electrophotographic printer - Google Patents

Abstract

A development apparatus for a liquid electrophotographic printer includes a development roller for supplying a developer liquid to a development region of a photoreceptor belt on which a latent electrostatic image is formed by being exposed to light, a squeegee roller for forming a developer liquid film on the photoreceptor belt by removing the excess developer liquid of the developer liquid sticking to the development region, and a wrap-around developer liquid removal means having a cleaning blade being in contact with both edges of the photoreceptor belt beyond the development region for removing the developer liquid on both edges of the photoreceptor belt.

Description

Developing equipment for wet electrographic printers

Technical field

The present invention relates to an improved developing apparatus of a wet electrographic printer for effectively removing developer remaining at the edge of a photosensitive belt with a simplified peripheral developer removal device.

technical background

Electrophotographic printers, such as laser printers, employ a photosensitive medium, such as a photosensitive drum or a photosensitive belt, on which an electrostatic latent image is formed.

Laser printers are mainly classified into wet printers and dry printers according to the type of toner used for development. The developer used in wet laser printers is a mixture of toner of a predetermined color and a volatile carrier.

Referring to FIG. 1, a conventional developing apparatus includes an endless photosensitive belt 110 and first, second, and third rollers 121, 122, 123 that circulate the photosensitive belt 110 around a prescribed path. The third roller 123 is a driving roller driven by a motor (not shown) to rotate the photosensitive belt 110 , and the second roller 122 is a guide roller to prevent bending by adjusting the torsion of the photosensitive belt 110 . A charging station 135 for charging the photosensitive belt 110 is located near a moving section of the photosensitive belt 110 between the first roller 121 and the second roller 122 . In a moving section of the photosensitive belt 110 between the first roller 121 and the second roller 122, a plurality of laser scanning units (LSU) 130 and a plurality of developing devices 140 are alternately disposed. Here, the plurality of laser scanning units LSU 130 forms electrostatic latent images on photosensitive areas of the photosensitive belt 110 by emitting laser beams to the photosensitive belt 110 according to image signals of various colors, and the plurality of developing devices 140 forms electrostatic latent images on the areas where the electrostatic latent images are formed. The electrostatic latent image is developed into a toner image using a developing solution of toner having a predetermined color mixed with a liquid carrier.

When the toner image passes between the first roller 121 and the transfer roller 124 , it is transferred onto the paper 126 by the transfer roller 124 . The paper 126 is fed between the transfer roller 124 and the press roller 125, and the press roller 125 is in contact with the transfer roller 124 at a constant pressure.

Referring to FIG. 2, a developing roller 141, a cleaning roller 142, first and second squeezing rollers 144 and 146 are disposed on the upstream side of the developing device 140, and a colored developer solution 148 is contained on the downstream side of the developing device. The developing roller 141 applies a developer solution 148 to the electrostatic latent image formed on the photosensitive belt 110 to develop the electrostatic latent image into a toner image. The developer 148 is supplied between the developing roller 141 and the photoreceptor belt 110 from the developer supplier 143 . The cleaning roller 142 removes the developer remaining on the surface of the developing roller 141 . The first and second squeeze rollers 144 and 146 remove excess developer solution 148 after developing the electrostatic latent image. The developer solution 148 sticking to the first and second squeeze rollers 144 and 146 is separated by scrapers 145 and 147 in contact with the surfaces of the first and second squeeze rollers 144 and 146 .

The developed toner image of the photosensitive belt 110 passes through first and second nip rolls 144 and 146, and then forms a film-like toner image containing some liquid carrier. While passing through the third roller 123 , the liquid carrier contained in the toner image is removed by the drying roller 171 heated by the heating roller 172 . The drying roller 171 absorbs the liquid carrier remaining on the surface of the photosensitive belt 110, and the liquid carrier absorbed by the drying roller 171 is evaporated by the heating roller 172, and then recovered by a recovery unit built into the apparatus.

Referring to FIGS. 3 and 4 , the developing roller 141 is kept at a predetermined distance from the photosensitive belt 110 and coats the supplied developer 148 on the photosensitive belt 110 while rotating in the same direction as the photosensitive belt 110 runs. At this time, the developer solution 148 is applied to the developing area having the same width as the developing roller 141 . The first squeeze roller 144 squeezes the developer applied on the developing area 115 to form a developer film 149 corresponding to the electrostatic latent image. Here, part of the developer is pressed toward both side edges of the photosensitive belt 110 due to the pressing motion of the first pressing roller 144 . The developer solution 151 at the edge of the photosensitive belt 110 is removed by the second squeeze roller 146 rotating in a direction opposite to the running direction of the photosensitive belt 110 . During this process, the peripheral developer 151 stuck to the second squeeze roller 146 is separated by the second scraper 147 in contact with the second squeeze roller 146 .

The first and second squeeze rollers 144 and 146 are rotated by separately provided driving means, and brought into or out of contact with the photosensitive belt by a lifter (not shown). In addition, scrapers 145 and 147 are provided corresponding to the first and second squeeze rollers 144 and 146 . Therefore, the structure of the whole system is very complicated. Then, when the squeeze rollers 144 and 146 are worn or damaged, the system must be separated through complicated steps to replace with new squeeze rollers.

As described above, since the conventional developing device has a complicated structure, disassembly and assembly of repair and replacement parts are not easy. In addition, replacement parts such as squeeze rollers are also expensive.

Contents of Invention

In order to solve the above-mentioned problems, an object of the present invention is to provide a developing device of a wet electrophotographic printer, which has a simplified structure and can effectively remove the developer adhering to the photosensitive belt.

Therefore, in order to achieve the above object, there is provided a developing device of a wet electrophotographic printer, which has: a developing roller for supplying a developing solution to a developing area of a photosensitive belt on which an electrostatic latent image is formed by exposure; The excess developing solution of the developing roller forms a developing solution film on the photosensitive belt, and it is characterized in that the developing device includes a peripheral developing solution removing device, which has cleaning blades contacting both side edges of the photosensitive belt outside the developing area, with The developer is used to remove the developer at the edge of the photosensitive belt; and the bracket, on which the cleaning blade is detachably installed; and the lifting device, which lifts the bracket up and down to make the cleaning blade come into or out of contact with the photosensitive belt.

Description of drawings

The above objects and advantages of the present invention will be more clear by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings, wherein:

Fig. 1 is the schematic diagram of the traditional developing equipment of the wet type electron imaging printing machine that adopts photosensitive belt as photosensitive medium;

FIG. 2 is a schematic diagram showing the internal structure of the conventional developing device in FIG. 1;

Figure 3 is a partially exploded side view of the developing device in Figure 2;

Figure 4 is a partially exploded front view of the developing device in Figure 2;

5 is a schematic side view of the developing device of the wet electrophotographic printer of the present invention;

Fig. 6 is a partial side view showing the relationship between elements of the developing device in Fig. 5 and the photosensitive belt;

Figure 7 is a schematic perspective view of the developing device in Figure 5;

Fig. 8 is a partially exploded schematic view of a peripheral developer solution removal device used in the developing device of the present invention.

Detailed ways

Referring to FIGS. 5 and 6 , a developing roller 541 that applies a developing solution 548 to the photosensitive belt 110 that forms an electrostatic latent image by exposure is disposed at an upper portion of a developing device 540 containing the developing solution 548 . Along the running direction of the photosensitive belt 110, a squeeze roller 544 for removing excess developing solution 548 adhering to the photosensitive belt 110 and a peripheral developing solution removing device 560 having a photosensitive belt cleaning blade 561 are set, and the removing device is used to remove The developer remaining on the edges of both sides of the photosensitive belt 110 outside the developing area.

The cleaning blade 561 of the peripheral developer removing device 560 is supported by a bracket 571 . The stand 571 is raised and lowered by a lifting device described below. Accordingly, the cleaning blade 561 can contact the photosensitive belt 110 or be separated from the photosensitive belt 110 . In order to prevent the photosensitive belt 110 from being damaged due to friction, the photosensitive belt cleaning blade is preferably made of a soft rubber material.

A developer solution supplier 543 that supplies a developer solution between the development roller 541 and the photosensitive belt 110 is provided on one side of the development roller 541 . A cleaning roller 542 that removes the developer solution 548 adhering to the surface of the developing roller 541 is provided on the lower side of the developing roller 541 . A squeeze roller cleaning blade 545 that removes developer 548 adhering to the surface of the squeeze roller 544 is provided on the downstream side of the squeeze roller 544 . On one side of the developing device 540, ie, the right side of the drawing, there is provided a laser scanning unit (LSU) 130 that emits a laser beam to a developing area of the photosensitive belt 110 running in a loop to form an electrostatic latent image.

The developing roller 541 applies a developing solution 548 supplied from a developing solution supplier 543 to a developing area where an electrostatic latent image is formed. When the developing roller 541 rotates, the developing roller 541 is cleaned by the developing roller cleaning roller 542 disposed at the lower portion of the developing roller 541 . Excess developer sticking to the developing area of the photosensitive belt 110 is removed by the squeeze roller 544 , and the developer stuck on the squeeze roller 544 is removed by a squeeze roller cleaning blade 545 disposed on the downstream side of the squeeze roller 544 . When cleaning is required, the photosensitive belt cleaning blade 561 is in contact with the photosensitive belt 110 through the lifting device, and is out of contact with the photosensitive belt 110 when cleaning is not required. The photoreceptor belt cleaning blades 561 of the peripheral developer removal device 560 contact both side edges of the photoreceptor belt 110 to remove developer appearing on both side edges outside the developing area after passing through the squeeze roller 544 .

During this process, only the toner image of the thin film pattern corresponding to the electrostatic latent image of the developed area remains on the photosensitive belt 110 . The toner image includes carriers, which are sucked by the third roller 123 into the drying rollers 151 , and the carrier absorbed by these drying rollers 151 is heated and evaporated by the heating roller 152 in contact with the drying roller 151 .

Referring to FIG. 7, as described above, the developing solution 548 adhered to the developing area 115 of the photosensitive belt 110 by the developing roller 541 is removed, excluding the necessary amount of developing solution required for development by the squeeze roller 544. At this time, the peripheral developing solution carried by both sides 550 of the photosensitive belt 110 and squeezed out by the squeeze roller 544 is removed by the photosensitive belt cleaning blade 561 .

The elevating device of lifting support 571 up and down comprises driving motor 591 , the camshaft 581 that is rotated by driving motor 591 , and the cam 582 that is installed on the camshaft 581 . The camshaft 581 is disposed under the bracket 571 . The cam 582 is mounted on the camshaft 581 for actually contacting the support rod 572 of the bracket 571 to move the bracket 571 up and down when rotating. A cam gear 583 is mounted on one end of the cam shaft 581 to rotate in cooperation with a motor gear 592 mounted on a shaft of a driving motor 591 .

To remove the peripheral developer 551 stuck on the photosensitive belt 110, the driving motor 591 is driven to rotate the cam shaft 581. As the cam shaft 581 rotates, the bracket 571 matched with the cam 582 rises, and the developer cleaning blade 561 rises correspondingly, thereby contacting the photosensitive belt 110 .

Referring to FIG. 8 , the developer cleaning blade 561 is detachably mounted on a bracket 571 . For this, an insertion groove 573 is formed on the bracket so that the developer cleaning blade 561 can be inserted. In addition, the developer cleaning blade 561 is fixed at a position where it is inserted into the insertion groove 573 of the bracket 571 by bolts 575 . Accordingly, bolt locking holes 562 and 574 are formed on the developer cleaning blade 561 and the holder 572, respectively.

As described above, since the developing device of the wet electrophotographic printer of the present invention employs the developer solution removing means having the blade for removing the peripheral developer solution, the peripheral developer solution can be efficiently removed. In addition, since the developer solution removing device has a simplified structure, the worn blade can be easily replaced. Furthermore, the replacement cost of the developer removal unit is reduced due to the use of scrapers which are less expensive than conventional squeeze rolls.

Claims (3)

1. the developing apparatus of a liquid electrophotographic printer has: developer roll (541), the development district supply developer solution of the sensitization band (110) that forms electrostatic latent image to passing through to expose; Compression roller (544) is bonded at the unnecessary developer solution in the district of developing and goes up formation developer solution film at sensitization band (110) by removal, it is characterized in that described developing apparatus comprises:

Periphery developer solution removal device (560), it has: the cleaning balde (561) that contacts with the both sides of the edge of sensitization band (110) outside the district of developing is used to remove the developer solution of sensitization belt edge; Support (571), described cleaning balde (561) are removably mounted on the support (571); And jacking gear, the described support of oscilaltion (571) makes cleaning balde (561) and sensitization band (110) enter or disengage.

2. developing apparatus as claimed in claim 1 is characterized in that, scraper plate (561) is made by soft rubber material.

3. developing apparatus as claimed in claim 1 is characterized in that, described support (571) comprises a cramp bar (572), and jacking gear comprises:

Drive unit (591);

Camshaft (581) by drive unit (591) rotation;

Be installed in the cam (582) on the camshaft (581),

Described cramp bar (572) can contact with cam (582) when cam (582) rotates and move up and down described support (571).

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