Printer apparatus with upstream toner recycling function

Abstract

A printer apparatus with an upstream toner recycling function includes: a drum; a development roller performing a developing operation on the drum; a print head performing an exposure operation on the drum; and a cleaner performing a cleaning operation on the drum. After a light sensing part of the drum is rotated through the print head, the light sensing part firstly passes through the cleaner, which cleans or loosens old toners on the drum, and then passes through the development roller, which attaches new toners to the drum.

Description

[Technical Field]

[0001] This invention relates to a printing device, and more particularly to a printing device with a pre-processed toner recycling function. [Previous Technology]

[0002] In traditional laser printers and photocopiers, toner from the toner cartridge is used as the developing material. Waste toner is generated during the printing process. Traditionally, a cleaner is installed after the transfer roller and before the photocopier to remove toner from the photosensitive drum. A toner collection box is used to collect the toner. When the toner collection box reaches a certain level, maintenance personnel remove the toner or replace the toner collection box. This mechanism design is complex and does not reduce the production of waste toner. [Summary of the Invention]

[0003] Therefore, one object of the present invention is to provide a printing device with a pre-processed toner recycling function, which can effectively recycle toner in the printing device for direct recycling and reduce the generation of waste toner.

[0004] To achieve the above objectives, the present invention provides a printing apparatus, comprising: a photosensitive drum; a developing roller for performing a developing action on the photosensitive drum; a print head for performing an exposure action on the photosensitive drum; and a cleaner for performing a cleaning action on the photosensitive drum. One photosensitive portion of the photosensitive drum is located after rotating through the print head. First, the old toner on the photosensitive drum is removed or loosened by the cleaner, and then new toner is attached to the photosensitive drum by the developing roller.

[0005] Through the above embodiment, a cleaner can be installed between the print head and the developing roller to clean or loosen the old toner on the photosensitive drum, so that the old toner can be recycled and reused. The recycled old toner can be directly attached to the photosensitive drum by the developing roller along with new toner, or it can be recycled into the toner cartridge. Because the quality of the old toner recycled nearby is still quite good, it can be used directly for developing and printing, which can effectively reduce the amount of waste toner and is quite in line with environmental protection requirements.

Implementation Method

[0006] Traditional designers believe that the photosensitive drum needs to be cleaned of toner before electrical application to facilitate electrical application and improve quality. However, the inventors of this case discovered that the toner on the photosensitive drum before electrical application has no effect on the quality of electrical application. Therefore, they overcame the traditional technical bias and made the following improved design.

[0007] Figures 1 and 2 show schematic diagrams of the first and second states of the printing apparatus 1 according to a preferred embodiment of the present invention. As shown in Figures 1 and 2, the printing apparatus 1 is a laser printer, comprising a photosensitive drum 10, a developing roller 20, a print head 30, and a cleaner 40.

[0008] The developing roller 20 performs a developing action on the photosensitive drum 10, that is, it allows toner to adhere to the photosensitive drum 10. The printhead 30 performs an exposure action on the photosensitive drum 10. The printhead 30 is, for example, an LED printhead (LPH) or a laser scanning unit (LSU).

[0009] The cleaner 40 includes, but is not limited to, brush heads such as bristles, foam brushes, and scrapers, for performing a cleaning action on the photosensitive drum 10. After the photosensitive part 11 of the photosensitive drum 10 rotates through the print head 30, the old toner C1 on the photosensitive drum 10 is first removed or loosened by the cleaner 40, and then new toner C2 is attached to the photosensitive drum 10 by the developing roller 20. For example, in Figure 1, the old toner C1 on the photosensitive part 11 is removed, while in Figure 2, new toner C2 is attached to the photosensitive drum 10. That is, the cleaner 40 is positioned downstream of the print head 30 and upstream of the developing roller 20, and the cleaner 40 is in direct contact with the photosensitive drum to remove old toner or loosen the adhesion between the old toner and the photosensitive drum. Loose or removed old toner C1 can adhere to the photosensitive drum 10 together with new toner C2, meaning the old toner C1 is redistributed on the photosensitive drum 10. Specifically, the removed or loose old toner C1, along with the new toner C2, is adhered to the photosensitive drum 10 by the developing roller 20. In one embodiment, the center line connecting the print head 30 and the developing roller 20 passes through or intersects with the cleaner 40.

[0010] The printing apparatus 1 may further include a transfer roller 50, a power supply roller 60, a toner cartridge 70, a supply roller 80, and a doctor blade 90. The photosensitive part 11 passes through the developing roller 20 and then through the transfer roller 50. The photosensitive drum 10 and the transfer roller 50 work together to transfer fresh toner C2 from the photosensitive drum 10 to a medium M passing between the photosensitive drum 10 and the transfer roller 50. The medium M can then be fixed and output. The power supply roller 60 performs a power supply process on the photosensitive drum 10. After passing through the transfer roller 50, the photosensitive part 11 passes through the power supply roller 60 and then through the print head 30. The developing roller 20 and the supply roller 80 are rotatably mounted in the toner cartridge 70.

[0011] In this embodiment, the toner cartridge 70 stores new toner C2 and receives old toner C1 brought back by the developing roller 20. Therefore, a portion of the old toner C1 may be directly reattached to the photosensitive drum 10, while another portion of the old toner C1 can be recycled back into the toner cartridge 70 by the faster-rotating developing roller 20. A scraper 90 is mounted on the toner cartridge 70 and contacts the developing roller 20 to scrape off a portion of the new toner C2.

[0012] Therefore, in the printing apparatus 1 of this embodiment, no other cleaner is provided between the transfer roller 50 and the cloth appliance 60, and the printing apparatus 1 does not include a waste toner collection tank, which is significantly different from conventional practices. Therefore, there is no need to periodically recycle or replace the waste toner collection tank. In order to recycle old toner C1, the toner cartridge 70 can be designed to have a stepped receiving part 71 located below the developing roller 20 for receiving old toner C1, and the end of the stepped receiving part 71 has a hook to prevent old toner C1 from falling. In this example, the connection between the cleaner 40 and the stepped receiving part 71 is through the clamping point between the photosensitive drum 10 and the developing roller 20, so that the stepped receiving part 71 can effectively receive old toner C1. It is worth noting that only a small amount of old toner C1 is received, not a large amount. Compared with conventional practices, the printing apparatus of this embodiment has a pre-processed toner recycling function.

[0013] In addition, a backstop 91 is fixed on the receiving part 71. The backstop 91 contacts and rubs against the developing roller 20, preventing toner from flowing out of the toner cartridge 70. The backstop is made of plastic. In one example, the angular velocity of the photosensitive drum 10, the developing roller 20, and the supply roller 80 is controlled by the design of the mechanism and gear reduction ratio. Different tangential velocities can be created by matching the outer diameter. For example, the tangential velocity of the supply roller 80 is greater than that of the developing roller 20, and the tangential velocity of the developing roller 20 is greater than that of the photosensitive drum 10, which is beneficial for toner recycling. On the other hand, the developing roller 20 and the supply roller 80 rotate in the same direction, which generates friction between the developing roller 20 and the supply roller 80, allowing toner to adhere to the developing roller 20. As an example regarding the materials, the outer layer of the supply roller 80 contains foam, the outer layer of the developing roller 20 contains rubber, and the photosensitive drum 10 contains an insulating material (charge transport layer, CTL, which can be a plastic material). The three have different coefficients of friction, resulting in different frictional forces (or surface energy). The frictional force of the supply roller 80 is greater than that of the developing roller 20, and the frictional force of the developing roller 20 is greater than that of the photosensitive drum 10, thereby achieving the developing effect.

[0014] In actual operation, when the printing equipment 1 receives a print signal, it activates the power supply 60 to apply a charge to the photosensitive drum 10, for example, to give it a negative charge. Then, the print head 30 illuminates the photosensitive drum 10 according to the print signal. The negative charge disappears from the illuminated portion of the photosensitive drum 10. The illuminated portion is determined by the image to be printed; the illuminated portion is where toner will be applied. Then, the cleaner 40 cleans the residual toner on the photosensitive drum 10, potentially removing some of the residual toner and loosening others. Next, the supply roller 80 attaches the toner from the toner cartridge 70 to the developing roller 20 through relative friction (it may also reattach loosened residual toner and new toner to the developing roller 20). Because the toner is negatively charged, after exposure, the developing roller 20 carries the toner onto the photosensitive drum 10. Because the illuminated parts of the photosensitive drum 10 have no electrical charge, the toner adheres to these parts due to electrostatic attraction. The unilluminated parts of the photosensitive drum 10, being negatively charged, repel the toner and thus do not adhere. Next, one side of the media M contacts the rotating photosensitive drum 10, while the other side contacts the transfer roller 50, transferring the toner previously attached to the photosensitive drum 10 onto the media M. However, the toner is only temporarily attached to the media M; therefore, heating and pressure rollers are used to permanently fix the toner onto the media M.

[0015] Through the above embodiment, a cleaner can be installed between the print head and the developing roller to clean or loosen the old toner on the photosensitive drum, so that the old toner can be recycled and reused. The recycled old toner can be directly attached to the photosensitive drum by the developing roller along with new toner, or it can be recycled into the toner cartridge. Because the quality of the old toner recycled nearby is still quite good, it can be used directly for developing and printing, which can effectively reduce the amount of waste toner and is quite in line with environmental protection requirements.

[0016] The specific embodiments described in the detailed description of the preferred embodiments are only used to facilitate the explanation of the technical content of the present invention, and are not intended to limit the present invention narrowly to the above embodiments. All variations and implementations made without departing from the spirit of the present invention and the scope of the patent application are within the scope of the present invention. [Simplified Explanation of the Diagram]

[0017] [Figure 1] shows a schematic diagram of a first state of a printing apparatus according to a preferred embodiment of the present invention. [Figure 2] shows a schematic diagram of a second state of a printing apparatus according to a preferred embodiment of the present invention.

Claims

1. A printing apparatus comprising: a photosensitive drum; a developing roller for performing a developing action on the photosensitive drum; a print head for performing an exposure action on the photosensitive drum; and a cleaner for performing a cleaning action on the photosensitive drum, wherein a photosensitive portion of the photosensitive drum, after being rotated through the print head and irradiated by the print head according to a printing signal, first has old toner on the photosensitive drum removed or loosened by the cleaner, and then new toner is attached to the photosensitive drum by the developing roller.

2. The printing apparatus of claim 1 further includes a transfer roller, wherein the photosensitive unit passes through the developing roller and then through the transfer roller, wherein the photosensitive drum and the transfer roller work together to transfer the new toner on the photosensitive drum to a medium passing between the photosensitive drum and the transfer roller.

3. The printing apparatus as claimed in claim 2 further includes an electrical cloth for applying an electrical cloth to the photosensitive drum, wherein the photosensitive part passes through the electrical cloth first and then through the print head after passing through the transfer roller.

4. The printing apparatus as claimed in claim 3 further includes a toner cartridge and a supply roller, wherein the developing roller and the supply roller are rotatably mounted in the toner cartridge.

5. The printing apparatus as claimed in claim 4, wherein the toner cartridge stores the new toner and receives the old toner brought back by the developing roller.

6. The printing apparatus as claimed in claim 4 further includes a scraper mounted on the toner cartridge and in contact with the developing roller to scrape off a portion of the new toner.

7. The printing apparatus as claimed in claim 4, wherein no other cleaner is provided between the transfer roller and the cloth appliance.

8. The printing apparatus as claimed in claim 4, wherein it does not include a waste toner collection tank.

9. The printing apparatus as claimed in claim 4, wherein the toner cartridge has a stepped receiving portion for receiving the used toner.

10. The printing apparatus as claimed in claim 1 is a laser printer, wherein the old toner that has been removed or loosened is attached to the photosensitive drum together with the new toner by the developing roller.

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