CN1139009C - Squeegee for developing roller - Google Patents

Abstract

A toner leveling device is used for a developing roller of a developing device in a photoelectric recording device. The developing device includes the developing roller, the feeding roller and the flattening blade, the flattening blade is in pressure contact with the developing roller, and one end of the flattening blade is fixed at a predetermined distance from the developing roller. At the position of the distance, the leveling blade includes: an elastic rubber, which is kept in contact with the developing roller; Force due to elastic deformation.

Description

Squeegee for developing roller

technical field

The present invention generally relates to a toner leveling blade for making the thickness of toner adhered to the surface of a developing roller uniform in a developing device for an image recording device employing photoelectric recording technology, Such as copiers, laser printers or fax machines.

The toner leveling scraper makes the thickness of the toner on the surface of the developing roller uniform, thereby ensuring the stability of image quality.

Background technique

As shown in FIG. 1 , a photoelectric recording device in the prior art generally includes a photosensitive roller 10 .

The above-mentioned devices along the clockwise direction of the photosensitive roller 10 are a charger 11 , a light source 12 , a developing device 13 , a printing head 14 and a cleaning device 15 . The above-mentioned photoelectric recording device is provided with a paper storage box on one side to accommodate paper, and on the other side is provided with a fixing device 18, a paper transfer device 16 and a supporting plate 19, wherein the fixing device fixes the colorant on the paper.

Once the charger 11 is connected to the high-voltage direct current power supply, corona discharge is performed to charge the surface of the photosensitive roller 10 . Then, the upper surface of the photosensitive roller 10 is scanned while the power source 12 emits light.

As a result of this optical scanning, a potential difference is formed on the surface of the photosensitive roller 10, thereby producing an electrostatic latent image.

Along with the rotation of photosensitive roller 10, once the electrostatic latent image reaches the vicinity of developing device 13, the toner on the developing roller 13a of developing device 13 just develops the electrostatic latent image on photosensitive roller 10 under the use of electric field, The developed electrostatic latent image becomes a visible image.

The visible image formed on the surface of the photosensitive roller 10 is then transferred to the surface of a sheet of paper passing over the printhead 14 .

The printed paper is transferred from the paper transfer device 16 to the fixing device 18, and fixed on the pressing roller 18b. Both the pressing of the pressing roller 18b and the pressure on the paper generate heat. The printed paper will be transported to pallet 19. After that, the toner adhering to the surface of the photosensitive roller 10 is cleaned by the cleaning device into an external waste toner tank (not shown).

The above-mentioned image recording device is generally in the shape of a box, and the photosensitive roller, the developing device and the cleaning device are all arranged in a box.

The above-mentioned photoelectric recording device removes the residual toner by mechanical means, and during the process of removing the residual toner by the cleaning device 15, the removed toner is stored in a box, and then transferred from the box to a waste toner box .

At present, the above-mentioned traditional method for cleaning the colorant has caused environmental pollution, and more seriously, the resulting waste is also very large.

Recently, a cleaner has been introduced on the surface of a photosensitive roller that is rotated in an electric field while a doctor blade is mechanically smoothed.

In the photoelectric recording apparatus without the above-mentioned cleaner, a space is provided at a certain position below the photosensitive roller to collect the toner remaining on the photosensitive roller. As shown in FIG. 3, means for leveling the toner is provided above the surface of the developing roller. A conventional doctor blade 20 is provided at a certain position above the upper surface of the developing roller 13a. The agitator 13b in the developing device 13 agitates the toner, and the agitated toner is supplied from the supply roller 13c to the side of the developing roller 13a. The toner supplied to the developing roller 13a is triboelectrically charged to a certain extent due to the friction between the developing roller 13a and the supply roller 13c.

The electric field generated between the developing roller 13a and the supply roller 13c causes the toner to adhere to the surface of the developing roller 13a. Along with the rotation of developing roller 13a, the toner adhering to it is trimmed by metal scraper 20 along with the rotation to have a uniform thickness, so that a toner layer of constant thickness is formed on the surface of developing roller 13a, and then the photosensitive roller 10 The image on the surface is developed, and the image on the photosensitive roller 10 is an electrostatic latent image generated under the action of an electric field.

The conventional means described above cannot function when the amount of toner on the surface of the developing roller 13a is too small because there is a gap between the doctor blade 20 and the developing roller 13a.

That is, as shown in FIG. 4, the amount of toner for development provided on the surface of the developing roller was too small, the printing effect was poor, and the amount of toner obtained on the paper was extremely limited. As a result, a large amount of toner remains on the surface of the photosensitive roller after the printing operation is completed (average 20 to 30 residues).

Correspondingly, the residual coloring agent itself is a kind of waste, and the environmental pollution caused is also very serious.

In addition, the excessive amount of toner on the surface of the developing roller is not convenient for conventional development methods.

Contents of the invention

Accordingly, it is an object of the present invention to provide a toner leveling blade capable of making the thickness of the toner on the surface of the developing roller uniform, thereby improving the printing effect.

Another object of the present invention is to provide a toner leveling blade which maintains a line contact with a developing roller so as to form a toner layer having a uniform thickness.

A further object of the present invention is to provide a toner leveling blade for use with a developing roller to remove excess toner.

A further object of the present invention is to provide a colorant leveling scraper, comprising a conductive elastic rubber, the elastic rubber is fixed on a thin metal sheet, the structure is very simple, by virtue of the elastic force of the metal sheet, the elastic rubber and the imaging The rollers remain in contact, improving the quality of the printed image.

To achieve these and other objects, a developing device is provided adjacent to a photosensitive roller of an electro-optical recording device. The developing device includes a developing roller, a supply roller and a leveling blade, wherein the developing roller is used to develop the electrostatic latent image on the surface of the photosensitive roller with a toner, and the supply roller is in contact with the developing roller by rubbing The action of force provides toner to the developing roller, and the flattening scraper maintains elastic contact with the developing roller, so that the toner on the developing roller can be leveled. The above-mentioned leveling blade includes an elastic rubber, one end of which is installed at a predetermined distance therefrom, and the other end is kept in contact with the developing roller.

The above-mentioned leveling blade includes an element that makes the elastic rubber elastic, so that the close contact between the leveling blade and the developing roller can be ensured.

Description of drawings

The present invention will be described in detail below in conjunction with the accompanying drawings. Through such description, the present invention can be appreciated more completely, and its many advantages are also clearer, and the present invention can be better understood at the same time. In the accompanying drawings, the same code represents the same or a similar element, where:

Fig. 1 is a side view of the layout of a photoelectric recording device of conventional structure;

Fig. 2 is the schematic diagram of the imaging device of the photoelectric recording device of conventional structure,

Fig. 3 is a structural schematic diagram of a toner leveling device in a developing device of a conventional structure;

Fig. 4 is a partial enlarged view of the coloring agent leveling device in Fig. 3;

Figure 5 is a perspective view of a preferred embodiment of a colorant leveling blade according to the present invention;

Figure 6 is a schematic diagram of a preferred embodiment of a colorant smoothing blade according to the present invention; and

Fig. 7 is a partially enlarged view of a colorant leveling blade according to the present invention.

Detailed ways

Referring now to Figure 6, this figure shows a colorant leveling device. One side of the photosensitive roller 1 of the photoelectric image device is provided with a developing device 2, which includes a space 3, an agitator 4, a feed roller 6 and a leveling scraper 7, and the space 3 is used for storing and accommodating the toner 50, and the agitator 4 is used to agitate the toner in the space, the supply roller 6 is arranged adjacent to the agitator 4 to supply the toner to the developing roller 5, and the leveling blade 7 is used to make the toner attached to the surface of the developing roller 5 uniform distributed.

Above-mentioned leveling scraper 7 comprises elastic rubber 71, thin metal sheet 72 and support 73, elastic rubber 71 is in contact with developing roller 5, thin metal sheet 72 is connected with elastic rubber 71, and support 73 makes thin metal plate 72 One end is firmly mounted on a fixing member 75 disposed at a predetermined distance from the developing roller.

Both the elastic rubber 71 and the developing roller 5 are made of conductive rubber, and both are connected to an external power supply. The power supply voltage of the developing roller 5 is about -200--600 volts.

The above-mentioned developing roller has a volume resistance value of about 10 ⁶ to 10 ⁹ Ω/cm.

The DC power supply voltage of the elastic rubber of the smooth scraper 7 is about -200-800 volts, and its volume resistance is about 10 ³ -10 ⁹ Ω/cm.

The portion of the elastic rubber 71 in contact with the developing roller 5 is arc-shaped.

The above rounded edge has a radius between 0.05 to 0.3mm, and the pressure in contact with the developing roller 5 is about 0.5g/cm-50g/cm. Therefore, in order for the elastic rubber 71 to be pressed against the surface of the developing roller 5, the metal elastic plate 72 needs to be slightly deformed, thereby leveling the toner in the developing device.

The operation of the preferred embodiment of the present invention will now be described in detail by way of an example which is not limited thereto. Once the preferred embodiment having the above structure is in operation, the photosensitive roller 1 is charged by a charger, scanned by light from a light source, an electrostatic latent image is formed in a developing device 2 and developed by a toner. As the agitator 4 rotates, the toner stored and accommodated in the space 3 of the developing device 2 is agitated and reaches the side of the supply roller 6 . The supply roller 6 is in frictional contact with the developer roller, thereby charging the toner to some extent and carrying the charged toner to the side of the developer roller 5 .

When the toner attached to the surface of the developing roller as it rotates reaches a position adjacent to the leveling blade 7, the elastic rubber 71 of the leveling blade 7 makes the thickness of the arriving toner uniform. As a result, the toner is evenly distributed on the surface of the developing roller.

The support 73 is firmly mounted on the fixing member 75 of the developing device, and the elastic rubber 71 provided at one end of the thin metal sheet 72 acts on the surface of the developing roller 5 with constant pressure.

The deformation of the thin metal sheet 72 keeps the elastic rubber in contact with the developing roller 5, thereby making the toner more uniform.

Turning now to Figure 7, there is a partially enlarged illustration of the leveling scraper. The elastic rubber 71 is in line contact with the developing roller 5 with a contact pressure of about 0.5 g/cm to 50 g/cm. At this time, the toner unevenly adhered to the surface of the developing roller 5 is uniformly processed by the elastic rubber 71 . This is done under the action of the elastic force produced by the deformation of the thin metal sheet 72 .

The contact surface 71a of the elastic rubber 71 has a circular arc shape, so that a small wedge-shaped gap is formed between the contact blade 71a of the elastic rubber 71 and the developing roller 5 .

The powdery toner in the aforementioned wedge-shaped gap is pressed and adhered to the surface of the developing roller 5 with friction in rotation at the contact position.

As a result, the uniformity of the toner attached to the developing roller 5 depends on the pressure applied to its surface. It is desirable to form a layer of toner powder of uniform thickness on the developer roller. In addition, experiments have shown that the ratio of the amount of toner remaining on the photosensitive roller to the toner supplied to the surface of the developing roller is about 1:70.

In order to prevent the accidental situation that the area where the toner is not supplied is the area where the electrostatic latent image cannot be developed, the speed of rotation of the developing roller is much faster than that of the photosensitive roller. The rotational speed ratio of the developing roller to the photosensitive roller is between 1:1.3 and 1:3, which can be adjusted according to the adhesion ratio of the toner on the surface of the developing roller.

Since the developing roller rotates faster than the photosensitive roller, there will be enough colorant to form a colorant layer during the developing process, thus ensuring the stable quality of the printed image.

As mentioned above, the preferred embodiment of the present invention can keep the mechanical structure stable while improving the printing effect, and the printing cost is also low.

Claims (14)

1. colorant flattening device is used for the developing roll (5) of the display (2) of PERD, and described display (2) is arranged on contiguous light-sensitive roller (1) and locates, and comprising:

Described developing roll (5) is used to make the lip-deep electrostatic latent image of described light-sensitive roller (1) to be able to develop with colorant;

A feed roller (6) contacts with described developing roll (5), and its rotation direction is opposite with developing roll (5), is used to make described colorant triboelectric charging and described colorant is provided; With

A smooth scraper (7) maintains contacting of pressure with described developing roll (5), is used to make the described colorant that adheres on the described developing roll (5) to be able to smooth; One end of wherein said smooth scraper (7) is fixed on the position that a preset distance is arranged with it, and described smooth scraper (7) comprising:

An elastic caoutchouc (71), keep in touch with the surface of developing roll (5) and

A foil (72) is installed on the retaining element (75), and described elastic caoutchouc (71) is applied the power that elastic deformation produced; Wherein, the limit blade branch (71a) of described elastic caoutchouc (71) and described developing roll (5) keep in touch, so that described colorant is able to is smooth, the maintenance of this contact is to be finished by the power that elastic deformation produced that foil (72) is produced.

2. painted flattening device as claimed in claim 1, wherein said foil (72) are installed on the mount pad that is made of metal in the described display (2).

3. between 0.05～0.3mm, described elastic caoutchouc (71) comprises conductive rubber usually for colorant flattening device as claimed in claim 1, the thickness of foil wherein (72).

4. colorant flattening device as claimed in claim 3, the volume resistance value of the described elastic caoutchouc (71) that comprises conductive rubber wherein is usually 10 ³～10 ⁸Between Ω/cm.

5. colorant flattening device as claimed in claim 4, the contact pressure on the limit blade branch (71a) of described elastic caoutchouc (71) wherein and the surface of described developing roll (5) is usually between 0.5～50g/cm.

6. colorant flattening device as claimed in claim 1, the limit sword (71a) of described elastic caoutchouc (71) wherein is circular-arc, and its radius is greatly between 0.05～0.3mm.

7. colorant flattening device as claimed in claim 1, external first power supply of making by conductive rubber of described developing roll (5) wherein, the volume resistance value of described developing roll (5) is 10 ⁶～10 ⁹Between Ω/cm.

8. colorant flattening device as claimed in claim 1, the supply voltage of described developing roll (5) wherein is usually between-200～-600 volts.

9. as the wherein any described colorant flattening device of claim 1 to 6, the external second source of described smooth scraper (7) wherein is to provide voltage to it.

10. colorant flattening device as claimed in claim 9, described smooth scraper (7) wherein is provided with a metal bearing, so that this smooth scraper (7) location and fixing.

11. colorant flattening device as claimed in claim 9, wherein said elastic caoutchouc (71) and foil (72) are connected together.

12. colorant flattening device as claimed in claim 9, the deformation direction of described smooth scraper (71) wherein is opposite with the throughput direction that described developing roll (5) is gone up colorant.

13. colorant flattening device as claimed in claim 9, the described light-sensitive roller (1) wherein and the rotating ratio of described developing roll (5) are usually between 1: 1.3～1: 3.

14. colorant flattening device as claimed in claim 9, the external power supply of smooth scraper (7) wherein, the supply voltage of this power supply is usually between-200～-800 volts.

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