WO2011124139A1

WO2011124139A1 - Cartridge

Info

Publication number: WO2011124139A1
Application number: PCT/CN2011/072506
Authority: WO
Inventors: 高瑞祺; 杨晓锋; 周宏辉
Original assignee: 珠海天威飞马打印耗材有限公司
Priority date: 2010-04-07
Filing date: 2011-04-07
Publication date: 2011-10-13
Also published as: CN101893837A

Abstract

A cartridge includes shell. A carbon powder chamber is arranged in the shell. Furthermore, a photosensitive drum ( 68 ), a charging roller (71 ) supplying power to the photosensitive drum ( 68 ), a development roller ( 56 ) supplying carbon powder to the photosensitive drum ( 68 ), and a powder discharge cutter ( 61 ) adjusting the thickness of the carbon powder layer on the development roller ( 56) are disposed in the shell. A conducting strip ( 65 ) is arranged at an end of the powder discharge cutter ( 61 ). A rectification device is connected between the conducting strip ( 65 ) and the powder discharge cutter ( 61 ).

Description

Processing box

Technical field

The present invention relates to a printing consumable, and more particularly to a process cartridge for a laser printer. The present invention is based on a Chinese patent application filed on Apr. 7, 2010, the application number of which is incorporated herein by reference.

Background technique

Laser printers are common printing devices that provide great convenience for modern office use. Most of the existing laser printers use a process cartridge that is detachably mounted in a laser printer to provide toner for printing. During the printing process, the toner loaded in the process cartridge is transferred onto the paper as a printing medium to form a desired paper. Patterns and text.

An existing type of process cartridge is an integrated box having a toner chamber for containing toner and a waste toner chamber for accommodating waste toner. The structure of the process cartridge is as shown in FIG.

Referring to Figure 1, the process cartridge has a housing 1 with a handle 15 for easy grasp by the user. Referring to Fig. 2, the casing 1 of the process cartridge is composed of a drum frame 11, a toner cavity frame 12, and two

end caps

13, 14, wherein the handle 15 is located on the drum frame 11. The toner chamber frame 12 has a toner chamber for accommodating the toner, and a powder feed roller 21, a developing roller 25, and a powder discharging knife 31 are disposed outside the toner chamber.

The drum frame 11 has a waste toner chamber for accommodating waste toner, and a photosensitive drum 36, a charging roller 41, and a cleaning blade 48 are disposed outside the waste toner chamber. When the process cartridge is assembled, the drum frame 11 and the toner cavity frame 12 are fixedly connected by the

end caps

13, 14 on both sides, and the drum frame 11, the toner cavity frame 12, and the

end caps

13, 14 enclose a cavity for powder feeding. Parts such as the roller 21, the developing roller 25, the powder discharging blade 31, the photosensitive drum 36, the charging roller 41, and the cleaning blade 48 are located in the cavity.

Referring to Fig. 3, the powder feeding roller 21 has a mandrel 22 made of metal, and the mandrel 22 is covered with an elastic layer 23 for adsorbing carbon powder. A conductive piece 24 is attached to one end of the mandrel 22, and the conductive piece 24 extends outside the end cover 14. After the process cartridge is mounted to the laser printer, the conductive sheet 24 is in contact with the electrical contacts of the laser printer, and the laser printer supplies voltage to the conductive sheet 24 through the electrical contacts.

Similarly, the developing roller 25 also has a mandrel 26 made of metal. The mandrel 26 is covered with an elastic layer 27, and the elastic layer 27 is made of a material such as sponge or rubber. The mandrel 26 is also connected with a conductive piece at one end thereof. 28, the outer end of the conductive sheet 28 extends outside the end cover 14. The conductive sheet 28 is connected to another electrical contact of the laser printer to receive a supply voltage from the laser printer. When the process cartridge is in operation, the outer surface of the developing roller 25 and the powder discharging blade 31 are pressed against each other to frictionally charge the carbon powder, and are adsorbed on the outer surface of the developing roller 25 by electrostatic adsorption.

The powder discharging blade 31 is disposed in parallel with the axis of the developing roller 25, and has a blade holder 32 and a blade 33 mounted on the blade holder 32 for scraping off excess toner adsorbed on the outer surface of the developing roller 25, The thickness of the carbon powder layer on the outer surface of the developing roller 25 is uniform. One end of the holder 32 is connected to the conductive sheet 34, and one end of the conductive sheet 34 extends outside the end cover 14. After the process cartridge is mounted to the laser printer, the conductive sheet 34 receives the voltage supplied by the laser printer.

The photosensitive drum 36 is disposed in parallel with the axis of the developing roller 25, the outer surface of the photosensitive drum 36 is a photosensitive layer, and the toner on the outer surface of the developing roller 25 can be transferred to the outer surface of the photosensitive drum 36.

As seen from the operation of the photosensitive drum 36, a charging roller 41 is provided upstream thereof, and the charging roller 41 has a metal core 42 which is provided with a conductive layer 43 outside, and the conductive layer 43 is in contact with the outer surface of the photosensitive drum 36. And power is supplied to the photosensitive drum 36. One end of the mandrel 42 is provided with a bracket 44 on which a spring 45 is attached, and the spring 45 is connected to the conductive piece 46. After the process cartridge is mounted to the laser printer, the conductive sheet 46 receives the voltage supplied from the laser printer and forms a high-voltage direct current on the charging roller 41, thereby charging the photosensitive drum 36 to negatively charge the outer surface of the photosensitive drum 36.

A cleaning blade 48 is provided downstream of the photosensitive drum 36 for scraping off the toner remaining on the outer surface of the photosensitive drum 36 after the transfer is completed.

Referring to Fig. 4, the toner on the outer surface of the developing roller 25 is transferred to the outer surface of the photosensitive drum 36. When the laser printer is operated, the toner accommodated in the toner chamber is supplied to the developing roller 25 by the powder feeding roller 21, and the powder feeding roller 21 is continuously rotated during operation, and its rotation direction is as indicated by an arrow A1 in Fig. 4.

The powder feeding roller 21 is adjacent to the outer surface of the developing roller 25, so that the toner adsorbed on the outer surface is transferred to the outer surface of the developing roller 25 during the rotation of the powder feeding roller 21, and the developing roller 25 is also continuously rotated during operation, and its rotation direction As shown by the arrow A2 in FIG.

During the rotation of the developing roller 25, the excess carbon powder on the outer surface thereof is scraped off by the powder discharging blade 31, and the blade 33 scrapes off the excessively thick carbon powder adsorbed on the outer surface of the developing roller 25, thereby ensuring the toner on the outer surface of the developing roller 25. The thickness of the layer is such that the thickness of the carbon powder layer on the outer surface of the developing roller 25 is uniform.

Since some toners may not be properly charged, or some of the toners have insufficient negative charge, the powder knife 31 also needs to have a certain amount of electricity. When scraping excess toner, it is necessary to have a positively charged carbon. The powder is neutralized to make it negatively charged, ensuring that the toner on the outer surface of the developing roller 25 has a uniform negative charge.

On the other hand, the charging roller 41 charges the photosensitive drum 36 to uniformly charge the outer surface of the photosensitive drum 36. When the laser printer is in operation, the laser irradiates the surface of the photosensitive drum 36 with laser light with image information. This process is an exposure process, and a latent image is formed in a region where the surface of the photosensitive drum 36 is irradiated, that is, the charge in the exposed region disappears and is electrically neutral.

Since the unexposed area on the photosensitive drum 36 is negatively charged, and the exposed area is electrically neutral, and the toner on the outer surface of the developing roller 25 is also negatively charged, the toner on the outer surface of the developing roller 25 is sensitized according to the principle of charge isotropic repulsion. The unexposed areas on the drum 36 are repelled. Also, since the voltage of the exposed region is higher than the voltage of the toner, the toner of the outer surface of the developing roller 25 is sent to the exposed portion of the outer surface of the photosensitive drum 36, which is a developing process.

Finally, the paper as the printing medium passes under the photosensitive drum 36, the toner is transferred onto the paper, and the toner is heated and fixed on the paper, and the printing work is completed.

After the photosensitive drum 36 completes the transfer process, the cleaning blade 48 scrapes off the toner remaining on the outer surface of the photosensitive drum 36, and the waste toner is collected into the waste toner chamber to avoid affecting the next printing duty cycle of the photosensitive drum.

technical problem

Since the laser printer applies alternating current to the conductive sheet 34 of the powder discharging blade 31, and the carbon powder is negatively charged by friction, the powder discharging blade 31 generates an adsorption force to the carbon powder during the positive half cycle of the alternating current, so that, during development, The electric field force of the toner will be weakened, and some large particles or toner particles with low charge amount will not be effectively transferred to the surface of the photosensitive drum 36, and at the same time, the positive electric charge of the polar carbon powder cannot be effectively neutralized. .

If the negative charge of the toner is insufficient or the electric field force is insufficient, the toner cannot be transferred to the surface of the photosensitive drum 36, but falls off from the developing roller 25, causing excessive gray spots on the paper, and causing printing. The text or pattern is not black enough, which also causes waste of toner. If the positively charged polar toner is not eliminated or neutralized, the positive polarity carbon powder is adsorbed on the unexposed area of the photosensitive drum 36, causing the areas where the characters or patterns are not formed to form a gray dot, which affects the print quality.

Technical solution

The main object of the present invention is to provide a process cartridge capable of effectively avoiding print quality problems;

Another object of the present invention is to provide a process cartridge that reduces waste of toner during printing.

In order to achieve the above main object, the present invention provides a process cartridge having a casing having a toner chamber for containing toner, and a photosensitive drum, a charging roller for supplying power to the photosensitive drum, and transferring toner to the photosensitive film. The developing roller of the drum and the powder discharging knife for adjusting the thickness of the carbon powder layer on the developing roller are provided with a conductive sheet at one end of the powder discharging knife, wherein a rectifying device is connected between the conductive sheet and the powder discharging knife.

A preferred solution is that the rectifying device has a half-wave rectifying circuit.

A further solution is that the half-wave rectifier circuit is a diode, the anode of the diode is connected to the powder discharge knife, and the cathode of the diode is connected to the conductive sheet.

DRAWINGS

Figure 1 is a structural view of a conventional process cartridge;

Figure 2 is a structural exploded view of a conventional process cartridge;

Figure 3 is a partially exploded enlarged view of a conventional process cartridge;

4 is a schematic enlarged view showing the structure of a powder feeding roller, a developing roller, a powder discharging knife, a charging roller, a photosensitive drum, and a cleaning blade of the conventional process cartridge;

Figure 5 is a partial structural view of the embodiment of the present invention after removing the casing and the cleaning blade;

Fig. 6 is a partially enlarged view showing the powder discharging knife and the diode in the embodiment of the present invention.

The invention will now be further described in conjunction with the various embodiments and the accompanying drawings.

Embodiments of the invention

The process cartridge according to the present invention has a casing composed of a drum frame, a toner cavity frame, and two end caps, and the toner cavity frame has a toner cavity for accommodating the toner, which is the same as the existing process cartridge. In the casing, the process cartridge is provided with components such as a powder feeding roller, a developing roller, a powder discharging knife, a charging roller, a photosensitive drum, and a cleaning blade.

Referring to Fig. 5, the powder feeding roller 51 has a mandrel 52 made of metal, and the mandrel 52 is covered with an elastic layer 53, and one end of the mandrel 52 is connected to the conductive piece 54, receiving the voltage supplied from the laser printer. Similarly, the developing roller 56 also has a mandrel 57 which is covered with an elastic layer 58 and one end of the mandrel 57 is connected to the conductive sheet 59 to receive the voltage supplied from the laser printer. The powder feeding roller 51 supplies toner to the outer surface of the developing roller 56, and the outer surface of the developing roller 56 and the powder discharging blade 61 rub against each other to cause the toner to be negatively charged.

The powder discharging knife 61 is located above the developing roller 56 for controlling the thickness of the toner layer adsorbed on the developing roller 56. One side of the developing roller 56 is provided with a photosensitive drum 68 whose axis is disposed in parallel with the axis of the developing roller 56.

A charging roller 71 is provided above the photosensitive drum 68, and an axis of the charging roller 71 is disposed in parallel with the axis of the photosensitive drum 68. The outer surface of the charging roller 71 is in contact with the outer surface of the photosensitive drum 68 and is loaded with high voltage power to the outer surface of the photosensitive drum 68.

The charging roller 71 has a mandrel 72 made of metal, and the mandrel 72 is covered with an elastic layer 73, and the outer surface of the elastic layer 73 is coated with a conductive material. One end of the mandrel 72 is sleeved with a bracket 74. The bracket 74 is mounted with a spring 75. The spring 75 is connected to the conductive piece 76, and the conductive piece 76 extends outside the end cover of the process box, receives the alternating current supplied by the laser printer, and makes the elastic layer A negative charge is formed on 73.

A cleaning blade (not shown in Fig. 5) is positioned above the photosensitive drum 68 for scraping off the toner remaining on the outer surface of the photosensitive drum 68 after the transfer.

Referring to Fig. 6, the powder discharging blade 61 has a blade holder 62 and a blade 63 mounted on the blade holder 62 for restricting excess toner on the developing roller 56 and making the thickness of the toner layer uniform. Further, the holder 62 is provided with an extending portion 64 at one end in the axial direction of the developing roller.

The tool holder 62 of the powder discharging knife 61 is provided with a conductive sheet 65 which extends outside the end cover of the process cartridge for receiving the alternating current supplied from the laser printer. A diode 81 as a rectifying means is provided between the tool holder 62 and the conductive sheet 65. The positive electrode of the diode 81 is soldered to the holder 62, and the negative electrode is soldered to the conductive sheet 65.

Thus, the positive half cycle current of the alternating current supplied from the laser printer to the conductive sheet 65 cannot flow through the diode 81, and the current on the powder discharging blade 61 does not flow through the positive half cycle. When the negative half of the alternating current flows through the conductive sheet 65, the diode 81 is turned on, and a negative half cycle current flows through the powder discharging knife 61. It can be seen that only the negative half cycle current can flow through the powder discharging knife 61, and the positive half cycle current cannot flow through the powder discharging knife 61, and the negative half cycle power on the powder discharging knife 61 is not offset by the positive half cycle power, and the powder discharging knife 61 is disposed. The negative power is larger and the negative charge is formed.

Of course, in the present embodiment, the diode 81 is used as a half-wave rectifying circuit. In practical applications, a bridge circuit can be used as a full-wave rectifying circuit to convert the positive half-cycle current of the alternating current into a negative direct current, which can greatly provide an effective alternating current. power.

When the laser printer is in operation, since the blade 63 of the powder discharging blade 61 has a sufficient negative charge to neutralize the positive charge of the polar toner, and the toner adsorbed on the developing roller 56 is evenly charged with a suitable amount of negative electricity, all carbon is ensured. The powder is transferred to the photosensitive drum 68 to avoid waste of toner. Also, be sure to print the blackness of the text and graphics, and also avoid toner defects on the paper.

Of course, the above solution is only a preferred embodiment of the present invention, and in practice, there may be more variations, such as using a dedicated rectifier circuit instead of a diode as a rectifying device; or, depending on the toner and the developing roller. The rectifying circuit may be a rectifying circuit that allows current to flow in a positive half cycle; or alternatively, the positive pole of the diode is connected to the extension of the tool holder rather than the body of the tool holder, and such changes do not affect the implementation of the present invention.

Finally, it should be emphasized that the present invention is not limited to the above embodiments, and minor changes such as changes in the rectifying device and changes in the connection position of the rectifying device should also be included in the scope of protection of the claims of the present invention.

Industrial applicability

Compared with the prior art, the powder discharging knife of the processing box provided by the present invention is not directly connected with the conductive sheet, but a rectifying device is disposed between the powder discharging knife and the conductive sheet, and the rectifying device can convert the alternating current into direct current, that is, The powder knife receives the DC power that only performs negative work. In this way, the voltage of the positive half cycle of the laser printer loaded into the conductive sheet is filtered by the rectifying device, and the negative power of the negative half cycle is received by the powder discharging knife, and the negative power of the powder discharging knife is greatly improved, and the polarity of the carbon powder can be effectively neutralized. Positive charge, and the carbon powder adsorbed on the developing roller is charged with sufficient electric field force to prevent the toner from falling off the developing roller, thereby ensuring the blackness of the printed pattern and the text, ensuring the print quality, and effectively reducing the toner. Waste.

Claims

Processing box, including

a housing having a toner chamber for containing toner, and a photosensitive drum, a charging roller for supplying power to the photosensitive drum, a developing roller for transferring toner to the photosensitive drum, and for adjusting a powder discharging knife having a thickness of a carbon powder layer on the developing roller, wherein one end of the powder discharging knife is provided with a conductive sheet;

It is characterized by:

A rectifying device is connected between the conductive sheet and the powder discharging knife.
The process cartridge according to claim 1, wherein:

The rectifying device has a half-wave rectifying circuit.
The process cartridge according to claim 2, wherein:

The half-wave rectifying circuit is a diode, and a positive pole of the diode is connected to the powder discharging knife, and a cathode of the diode is connected to the conductive sheet.
The process cartridge according to claim 1, wherein:

The rectifying device has a full wave rectifying circuit.
A process cartridge according to any one of claims 1 to 4, characterized in that:

The powder discharging knife comprises a tool holder and a blade mounted on the tool holder, and one end of the rectifying device is coupled to the tool holder.
A process cartridge according to claim 5, wherein:

One end of the tool holder is provided with an extension, and one end of the rectifying device is connected to the extension.