CN201210228Y - Developing device for laser printer - Google Patents

Abstract

The utility model relates to a developing device that is used for a laser printer, which comprises a powder cabin, a powder transmission roll and a developing roll. The developing roll is arranged in the powder discharging port of the powder cabin. The parts, which are close to the shaft end, of the developing roll are respectively contacted with a sealing pad. The gap between the powder discharging port and the developing roll is sealed by a sealing film. The sealing film is connected with the exterior of a developing framework along with the powder discharging direction and corresponding to the body of the developing roll. Both end parts of the sealing film along the axial direction of the developing roll are respectively connected with the sealing pad. Along with the axial direction of the developing roll, a separation seam is arranged between the sealing film and the sealing part, and between the sealing film and the body of the developing roll. The separation seam extends from the sticky position of the sealing film to the position that the sealing film is contacted with the developing roll. The splicing of the sealing film of the developing device is firm, and the contact is homogenous, thereby can prevent the carbon powder from being leaked at both ends parts of the developing device.

Description

Developing device for laser printer

technical field

The utility model relates to a developing device for an electrophotographic imaging device such as a laser printer, in particular to a developing device equipped with a powder feeding roller for transferring carbon powder and a developing roller for transferring the carbon powder to a photosensitive drum to convert an electrostatic latent image into a visible image device.

Background technique

Electrophotographic imaging devices, such as laser printers, irradiate a photosensitive drum with a predetermined potential by laser scanning to form an electrostatic latent image on its surface. The electrostatic latent image is developed with a predetermined toner, and then the developed image is transferred to the paper, and then the transferred image is fixed to become a visible image that can be observed by the naked eye, thereby realizing the image-signal - Transformation between images.

A common laser printer is provided with a charging roller, a photosensitive drum, a laser scanning mechanism, a developing device, a transfer roller, a fixing roller, etc. in its casing.

The photosensitive drum is charged to a predetermined potential by a charging roller, and forms an electrostatic latent image corresponding to an image to be printed in response to a laser beam emitted by a laser scanning mechanism.

The developing device stores toner in its built-in container, and transfers the toner to a photosensitive drum with an electrostatic latent image by using a toner feed roller and a developing roller.

The visible image formed on the photosensitive drum is transferred to the paper between the photosensitive drum and the transfer roller through the transfer roller, and finally the toner image on the paper is fixed by the fixing roller.

The above-mentioned developing device, on the one hand, uses the powder bin to undertake the storage task of toner, and on the other hand, the powder feeding roller and the developing roller are arranged inside the developing device at the same time, and the toner is transferred between the powder feeding roller and the developing roller through the powder feeding roller and the developing roller. The transfer between the rollers and the transfer of toner between the developing roller and the photosensitive drum complete the conversion between the electrostatic latent image of the photosensitive drum and the visible image. The developing device as a whole includes a powder bin, a powder feeding roller and a developing roller. It can be fixedly connected with the image processing unit where the photosensitive drum is located through a pin shaft and a pin hole. In this way, an integrated laser printer process box is obtained; Fit assembly when installing, what this way obtains is split-type laser printer processing box.

Regardless of whether it is an integral type or a split type laser printer processing box, the developing roller is located in the powder outlet of the powder bin. Therefore, sealing measures must be taken between the corresponding gap between the developing roller and the powder outlet, so as to prevent the toner in the powder bin from leaking from the aforementioned gap. Usually, the gap above the powder outlet corresponding to the developing roller is closed by a powder outlet knife, and the gap corresponding to the powder outlet below the developing roller is closed by a sealing film. Along the powder discharge direction in the powder outlet, the sealing film is bonded to the outside of the developing frame corresponding to the developing roller body; in the same direction, the end of the sealing film opposite to the bonding part is in contact with the developing roller body to complete the seal . The two ends of the sealing film corresponding to the axial direction of the developing roller often cause loose seal and powder leakage due to degumming of the bonding parts.

Utility model content

The purpose of the utility model is to provide a developing device for an electrophotographic imaging device such as a laser printer. The developing device can effectively improve the stress distribution state of the sealing film and avoid the two ends of the sealing film corresponding to the axial direction of the developing roller due to insufficient force. Degumming and resulting powder leakage occur.

According to the above-mentioned purpose, the development device for laser printer proposed by the utility model includes a powder chamber surrounded by a development frame for storing carbon powder, a powder feeding roller that can transmit carbon powder, and can absorb carbon powder and transfer it to the photosensitive drum. The developing roller of the photosensitive unit. The two shaft ends of the developing roller are respectively supported on the developing frame. The developing roller body is located in the powder outlet of the powder bin. The parts near the two shaft ends of the developing roller are respectively in contact with elastic sealing gaskets. The powder outlet is closed by a powder knife corresponding to the gap above the developing roller. The powder outlet is closed by a sealing film corresponding to the gap below the developing roller. The sealing film is bonded to the outer part of the developing frame corresponding to the developing roller body along the powder outlet direction. The length of the sealing film along the axial direction of the developing roller is close to the length along the same direction of the developing roller. Both ends of the sealing film along the axial direction of the developing roller are respectively lapped on the sealing gasket. Along the axial direction of the developing roller, a separation gap is provided between the part of the sealing film corresponding to the sealing gasket and the part corresponding to the body of the developing roller. The separation seam extends from the bonding position of the sealing film to the position where the sealing film contacts the developing roller along the powder discharge direction.

Aiming at the phenomenon that the two ends of the sealing film corresponding to the axial direction of the developing roller are often not tightly sealed due to the degumming of the bonding part, the applicant analyzed that the cause of this phenomenon is mostly caused by the uneven force on the sealing film, so in this paper In the development device for the utility model laser printer, the two ends of the sealing film along the axial direction of the developing roller are lapped on the sealing gasket respectively, and along the axial direction of the developing roller, the parts of the sealing film corresponding to the sealing gasket and the corresponding A separation gap is set between the parts of the developing roller body; the length of the separation gap along the powder outlet direction is kept between the bonding position of the sealing film and the position where the sealing film contacts the developing roller. In this way, when the developing roller body presses the end of the sealing film relative to the bonding position, the resulting acting moment will be respectively applied to the part of the sealing film corresponding to the sealing gasket and the part corresponding to the developing roller body, thus, The original interrelated force situation between these two parts will be changed to the situation of independent force, so the required bonding strength can be adjusted according to the actual force, so that the part of the sealing film corresponding to the sealing gasket And the part corresponding to the roller body of the developing roller can obtain a good sealing effect.

Illustration

Figure 1 is a perspective view of a developing device for a laser printer of the present invention.

Fig. 2 is a perspective view of the sealing film of the developing device for the laser printer of the present invention.

FIG. 3 is a partially enlarged schematic diagram of FIG. 2 .

Detailed ways

Referring to Figures 1-3, there are shown relevant views of the developing device for a laser printer of the present invention and its corresponding structural components.

1, the developing device A structurally includes a sealed toner storage bin 102 for storing toner, a powder feeding roller (not shown in the figure) and a developing roller 106 surrounded by several outer walls of the developing frame 101. The toner storage bin 102 has a cavity inside which can store toner. The powder feeding roller is integrally arranged inside the toner storage bin 102, and its two shaft ends are respectively supported on two opposite bin walls 104, 105 of the developing frame 101, and it can rotate under the driving force provided by the printer, and then the The toner in the toner storage bin 102 is transported to the vicinity of the developing roller 106 from a position farther away from the developing roller 106 . The roller body of the developing roller 106 straddles the toner outlet 107 of the toner storage bin 102 , that is to say, a part of the roller body is located in the toner storage bin 102 , and a part is exposed outside the toner storage bin 102 . The developing roller 106 is in contact with elastic sealing gaskets 109 at positions close to its two axial ends respectively. The sealing gasket 109 is lined on the developing frame 101 . The central axis of the developing roller 106 is parallel to the powder feeding roller, and its two axial ends are respectively supported on two opposite chamber walls 104 , 105 of the developing frame 101 . A predetermined distance is maintained between the chamber walls 104 and 105 in the direction of the central axis of the developing roller 106, and the length of the distance is adapted to the length of the central axis of the developing roller 106 to provide a predetermined space for accommodating the developing roller 106, and their surfaces are all vertical On the central axis of the developing roller 106.

In the assembled state, the developing device A is placed in the corresponding frame or frame (not shown in the figure) of the laser printer as a whole, and the exposed part of the developing roller 106 facing the powder outlet 107 is kept adjacent to the photosensitive unit belonging to the photosensitive unit. drum head. The developing roller 106 can rotate under the action of the driving force provided by the laser printer, and the toner from the powder feeding roller is adsorbed on the surface of its own cylindrical roller in the form of electrostatic adsorption. After the thickness and distribution uniformity of the toner layer meet the predetermined requirements, the toner is transferred to the drum surface of the photosensitive drum based on the potential difference as the basis of its toner adsorption, and then the toner covers the electrostatic potential on the drum surface of the photosensitive drum. image, and finally convert the electrostatic latent image into a visually visible toner image.

The gap between the top of the roller surface of the developing roller 106 and the powder outlet 107 is closed by a powder outlet knife 108 . Simultaneously, between the powder outlet knife 108 and the radially upper roller surface of the developing roller 106 within the axial length range of the developing roller 106, under the state that the developing roller 106 rotates, there is a relationship of sliding friction between them. The gap between the lower part of the roller surface of the developing roller 106 and the powder outlet 107 is closed by a sealing film 110 . The sealing film 110 is bonded to the outside of the developing frame 101 corresponding to the roller body of the developing roller 106 along the powder discharge direction. The length of the sealing film 110 along the axial direction of the developing roller 106 is close to the length of the same direction of the developing roller 106 . Both ends of the sealing film 110 along the axial direction of the developing roller 106 overlap the sealing gasket 109 respectively.

Referring to Figures 2 and 3, combined with Figure 1, the sealing film 110 is a strip-shaped sheet made of plastic. Along the central axis of the developing roller 106 , between the portion of the sealing film 110 corresponding to the gasket 109 and the portion corresponding to the body of the developing roller 106 , a separation slit 103 is provided. In the state where the sealing film 110 is assembled into the developing device A, the length of the separation slit 103 along the powder discharge direction α in the powder discharge knife 108 is between the bonding position of the sealing film 110 and the position where the sealing film 110 contacts the developing roller 106. between positions.

Claims (1)

1. A developing device for laser printers, including a toner chamber surrounded by a developing frame for storing toner, a toner feeding roller that can transport toner, and a developing roller that can absorb toner and transfer it to the photosensitive unit where the photosensitive drum is located, The two shaft ends of the developing roller are respectively supported on the developing frame, the body of the developing roller is located in the powder outlet of the powder chamber, and the parts close to the two shaft ends of the developing roller are respectively connected with elastic sealing gaskets. contact, the powder outlet is closed by a powder knife corresponding to the gap above the developing roller, and the powder outlet is closed by a sealing film corresponding to the gap below the developing roller, and the sealing film is bonded to the The developing frame corresponds to the outside of the developing roller body along the powder outlet direction, and is characterized in that the length of the sealing film along the axial direction of the developing roller is close to the length in the same direction of the developing roller, and the sealing film is along the The two axial ends of the developing roller are respectively overlapped on the sealing gasket, and along the axial direction of the developing roller, the part of the sealing film corresponding to the sealing gasket and the roller body of the developing roller are respectively overlapped. There is a separation gap between the parts, and the separation gap extends from the bonding position of the sealing film to the position where the sealing film contacts the developing roller along the powder discharge direction.

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