Printing device

Abstract

A printing apparatus includes a photosensitive drum, a developing roller that performs a developing operation on the photosensitive drum, a print head that performs an exposure operation on the photosensitive drum, and a cleaner that performs a cleaning operation on the photosensitive drum. After the photosensitive portion of the photosensitive drum is rotated through the print head, old toner on the photosensitive drum is first removed or loosened by the cleaner, and then new toner is attached to the photosensitive drum by the developing roller.

Description

Technical Field

[0001] This utility model relates to the field of printing equipment, and in particular to a printing device with a pre-processed toner recycling function. Background Technology

[0002] In traditional laser printers and copiers, toner cartridges are used as the developing material. Waste toner is generated during the printing process. The traditional method involves a cleaner installed after the transfer rollers and before the print head 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 collection box. This design is complex and does not reduce the amount of waste toner produced. Utility Model Content

[0003] Therefore, one objective of this 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, this utility model provides a printing device, 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. After the photosensitive part of the photosensitive drum rotates past the print head, the old toner on the photosensitive drum is first removed or loosened by the cleaner, and then new toner is attached to the photosensitive drum by the developing roller.

[0005] Through the above embodiments, a cleaner can be installed between the printhead and the developing roller to clean or loosen the old toner on the photosensitive drum, allowing the old toner to be recycled. 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 locally is still quite good, it can be directly used for developing and printing, thus effectively reducing the amount of waste toner and meeting environmental protection requirements. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the first state of the printing device according to a preferred embodiment of the present invention.

[0007] Figure 2 This is a schematic diagram of the second state of the printing device according to a preferred embodiment of the present invention.

[0008] Explanation of reference numerals in the attached figures:

[0009] M: Media;

[0010] C1: Used toner;

[0011] C2: New toner;

[0012] 1: Printing equipment;

[0013] 10: Photosensitive drum;

[0014] 11: Photosensitive area;

[0015] 20: Developing roller;

[0016] 30: Print head;

[0017] 40: Cleaner;

[0018] 50: Transfer roller;

[0019] 60: Cloth electrical appliances;

[0020] 70: Toner cartridge;

[0021] 71: Receiving Department;

[0022] 80: Supply rollers;

[0023] 90: Scraper;

[0024] 91: Backstop tablet. Detailed Implementation

[0025] Traditional designers believed that the photosensitive drum needed to be cleaned of toner before electrical application to facilitate the application and improve its quality. However, the inventor of this utility model application discovered that the toner on the photosensitive drum before electrical application has no effect on the quality of electrical application. Therefore, in order to overcome the traditional technical bias, the following improved design was made.

[0026] Figure 1 and Figure 2 These are schematic diagrams showing the first and second states of the printing device 1 according to a preferred embodiment of the present invention. Figure 1 and Figure 2 As shown, the printing device 1 is a laser printer, which includes a photosensitive drum 10, a developing roller 20, a print head 30, and a cleaner 40.

[0027] 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).

[0028] The cleaner 40 includes, but is not limited to, brush heads such as bristles, foam brushes, and scrapers, for cleaning the photosensitive drum 10. After the photosensitive part 11 of the photosensitive drum 10 rotates through the printhead 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 In the process, the old toner C1 on the photosensitive area 11 is removed, while... Figure 2 In this process, new toner C2 adheres to the photosensitive drum 10. That is, the cleaner 40 is positioned downstream of the printhead 30 and upstream of the developing roller 20, directly contacting the photosensitive drum 10 to remove old toner C1 or loosen the adhesion between the old toner C1 and the photosensitive drum 10. The loosened or removed old toner C1 can adhere to the photosensitive drum 10 together with the new toner C2, meaning the old toner C1 is redistributed on the photosensitive drum 10. In other words, the removed or loosened 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 connection between the printhead 30 and the developing roller 20 passes through or intersects with the cleaner 40.

[0029] Printing apparatus 1 may also include a transfer roller 50, a fabrication unit 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 the medium M passing between the photosensitive drum 10 and the transfer roller 50. The medium M can then be fixed and output. The fabrication unit 60 applies electrical flux to the photosensitive drum 10. After passing through the transfer roller 50, the photosensitive part 11 first passes through the fabrication unit 60 and then through the printhead 30. The developing roller 20 and the supply roller 80 are rotatably mounted in the toner cartridge 70.

[0030] In this embodiment, the toner cartridge 70 stores new toner C2 and receives old toner C1 brought back by the developing roller 20. Therefore, some 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.

[0031] Therefore, in the printing device 1 of this embodiment, no additional cleaner is provided between the transfer roller 50 and the power supply 60, and the printing device 1 does not include a waste toner collection tank, which is significantly different from conventional methods in the art. Therefore, there is no need to periodically recycle or replace the waste toner collection tank. To recycle old toner C1, the toner cartridge 70 can be designed with a stepped receiving portion 71 located below the developing roller 20 to receive old toner C1, and the end of the stepped receiving portion 71 has a hook to prevent old toner C1 from falling. In this embodiment, the cleaner 40 and the stepped receiving portion 71 are connected through the clamping joint between the photosensitive drum 10 and the developing roller 20, so that the stepped receiving portion 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 to conventional methods, the printing device 1 of this embodiment has a pre-processed toner recycling function.

[0032] Additionally, a backstop 91 is fixed to 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 91 is made of plastic. In one embodiment, the angular velocities of the photosensitive drum 10, the developing roller 20, and the supply roller 80 are controlled by the design of the mechanism and gear reduction ratio, which, combined with the outer diameter, can create different tangential velocities. 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, causing friction between them to allow toner to adhere to the developing roller 20. In one embodiment regarding the materials, the outer layer of the supply roller 80 comprises foam, the outer layer of the developing roller 20 comprises rubber, and the material of the photosensitive drum 10 comprises an insulating material (charge transport layer (CTL), which can be a plastic material). The three materials 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.

[0033] In actual operation, when the printing device 1 receives a print signal, it activates the power distributor 60 to apply a charge to the photosensitive drum 10, for example, to 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. Next, the cleaner 40 cleans the residual toner on the photosensitive drum 10, potentially removing some residual toner and loosening others. Then, the supply roller 80 attaches toner from the toner cartridge 70 to the developing roller 20 through relative friction (it may also reattach loosened residual toner and new toner C2 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 is attracted to these illuminated parts due to electrostatic attraction. The unilluminated parts of the photosensitive drum 10, being negatively charged, repel the toner and therefore do not adhere to them. 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. At this point, 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.

[0034] Through the above embodiments, a cleaner can be installed between the printhead and the developing roller to clean or loosen the old toner on the photosensitive drum, allowing the old toner to be recycled. 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 locally is still quite good, it can be directly used for developing and printing, thus effectively reducing the amount of waste toner and meeting environmental protection requirements.

[0035] The specific embodiments described in the detailed description of the preferred embodiments are only used to facilitate the explanation of the technical content of this utility model, and are not intended to narrowly limit this utility model to the above embodiments. All changes and implementations made without departing from the spirit of this utility model and the scope of the patent application are within the scope of this utility model.

Claims

1. A printing device, characterized in that, Include: Photosensitive drum; The developing roller performs the developing action on the photosensitive drum; The printhead performs an exposure operation on the photosensitive drum; and The cleaner performs a cleaning action on the photosensitive drum, wherein after the photosensitive part of the photosensitive drum rotates through the printhead, the old toner on the photosensitive drum is first removed or loosened by the cleaner, and then new toner is attached to the photosensitive drum by the developing roller.

2. The printing device as described in claim 1, characterized in that, It also includes a transfer roller, wherein the photosensitive portion 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 through the photosensitive drum and the transfer roller.

3. The printing device as described in claim 2, characterized in that, It also includes an electrical cloth generator to apply electrical treatment to the photosensitive drum, wherein the photosensitive part, after passing through the transfer roller, first passes through the electrical cloth generator and then through the print head.

4. The printing device as described in claim 3, characterized in that, It also 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 device as described in claim 4, characterized in that, The toner cartridge stores the new toner and receives the old toner brought back by the developing roller.

6. The printing device as described in claim 4, characterized in that, It also 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 device as described in claim 4, characterized in that, There is no other cleaner between the transfer roller and the cloth appliance.

8. The printing device as described in claim 4, characterized in that, This does not include waste carbon powder collection tanks.

9. The printing device as described in claim 4, characterized in that, The toner cartridge has a stepped receiving section for receiving the old toner.

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

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