A control circuit for increasing the potential difference between a developing roller and a powder feeding roller and a printer thereof

Abstract

The invention discloses a control circuit for increasing the potential difference between a developing roller and a powder feeding roller and a printer thereof, which are applied to powder feeding of the printer and include a developing bias circuit unit and a toner drum circuit unit. The developing bias circuit unit is arranged in the printer body, and the developing bias circuit unit provides a developing bias to the toner drum circuit unit. The toner drum circuit unit includes a developing roller and a powder feeding roller, and the two ends of the developing roller and the powder feeding roller are respectively connected to the circuit through wires; the developing bias circuit unit provides a single developing bias to the toner drum circuit unit independently; the developing roller and the powder feeding roller in the toner drum circuit unit are arranged in parallel and connected to the developing bias of the developing bias circuit unit, and the powder feeding roller circuit is also connected in series with a voltage stabilizing diode for reducing the developing bias so that a potential difference is formed between the developing roller and the powder feeding roller to facilitate the powder feeding roller to effectively feed powder.

Description

Technical Field

[0001] The invention relates to the technical field of printers, and in particular to a control circuit for increasing the potential difference between a developing roller and a powder feeding roller and a printer thereof. Background Art

[0002] Electrophotographic imaging devices, such as laser printers, form an electrostatic latent image on the surface of a photosensitive drum with a predetermined potential by laser scanning. The electrostatic latent image is developed with a predetermined toner, and then the developed image is transferred to paper. The transferred image is then fixed to become a visible image that can be observed by the naked eye, thereby realizing the conversion between image-signal-image.

[0003] In the field of imaging technology, a common laser printer has a charging roller, a photosensitive drum, a laser scanning mechanism, a developing device, a transfer roller, and a fixing roller in its casing; the charging method of a general laser printer, such as Figure 1 As shown, the charging roller 1' uses electric charge on the surface of the photosensitive drum 3' to charge the photosensitive body, and the laser scanning device 2' leaks light (according to the data input by the controller, the laser beam irradiates the photosensitive drum 3' to neutralize the conductive part and form a latent image. The toner particles 4' formed by neutralization or crushing are supplied to the developing roller 5' through the powder feeding roller 6', and the toner particles 4' are used to transfer the latent image on the surface of the photosensitive drum 3' to the visible image. In this process, in order to make the toner particles 4' uniformly fixed on the paper, the powder scraper 7' is used to control the charged layer of the toner particles 4'. Then, the toner particles 4' on the surface of the photosensitive drum 3' are transferred to the paper 9' through the charging roller 1' and the transfer roller 8'; the paper 9' melts the toner particles 4' and fixes them to the paper 9' through the pressure wheel 10' that can pressurize and force the toner particles 4', and finally the residual toner particles 4' on the surface of the photosensitive drum 3' are cleaned up by the cleaning roller.

[0004] Therefore, the existing laser printers use the electrostatic development principle, using the movement of charged particles in an electric field to complete the entire development process. Among them, the toner utilization rate of contact development is generally between 80-90%. Despite this, there is still 10-20% of toner that cannot be effectively utilized and becomes waste toner. The generation of waste toner will bring the following problems: 1. The volume of the toner box increases, and the capacity of the waste toner bin and the toner bin needs to be increased to meet the needs of the same page output; 2. The development cost increases, and the toner filling amount needs to be increased compared to the toner box with the same page output; 3. The pollution to the environment increases, and the environmental protection is reduced.

[0005] Therefore, it is necessary to improve the utilization rate of toner in electrostatic development in view of the above problems. Under the principle of electrostatic development, the key factors affecting the development process, especially the utilization rate of toner, include the toner charge and the electric field force. When the toner charge is constant, the magnitude of the electric field force determines the amount of toner that can be moved to the surface of the developing roller; and the magnitude of the electric field force depends on the magnitude of the developing bias V1 on the surface of the developing roller and the surface voltage V2 of the powder feeding roller. In other words, △V=|V1|-|V2| determines the magnitude of the electric field force. That is, by forming an electric field between the developing roller 5' and the powder feeding roller 6', the toner is physically transported to the surface of the developing roller 5' and physically attached to the developing roller 5'. In order to develop the electrostatic latent image on the photosensitive body, a voltage that generates the necessary potential difference is applied to the developing roller 5'. In the prior art, a plurality of power supply voltages are usually provided. When the surface potential of the photosensitive body is set to about -650V, a developing bias voltage of -350V is applied to the developing roller 5' through a power supply voltage. In addition, in order to generate the necessary polarity and electric field voltage to make the toner electrostatically move from the powder feeding roller 6 to the developing roller 5', a voltage of -400V to -700V is applied to the powder feeding roller 4 through another power supply voltage, such as applying a voltage of -650V. The power supply method using a plurality of power supply voltages makes the circuit structure between the developing roller 5' and the powder feeding roller 6' of the printer complicated, thereby increasing the production cost of the printer. Moreover, in the already narrow space of the printer, the complicated circuit structure is not only inconvenient for setting and connecting the circuits, but also greatly reduces the reliability of the product. Summary of the invention

[0006] The present invention provides a control circuit for increasing the potential difference between a developing roller and a powder feeding roller and a printer thereof with a simple structure and high reliability, which is convenient for adjusting the voltage difference between the developing roller and the powder feeding roller, improves the powder feeding quality and powder feeding efficiency of the powder feeding roller, and effectively improves the utilization rate of carbon powder.

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] A control circuit for increasing the potential difference between a developing roller and a powder feeding roller, applied to powder feeding of a printer, comprising a developing bias circuit unit and a toner drum circuit unit, wherein the developing bias circuit unit is arranged in the printer body, and the developing bias circuit unit provides a developing bias to the toner drum circuit unit, wherein the toner drum circuit unit comprises a developing roller and a powder feeding roller, and both ends of the developing roller and the powder feeding roller are respectively connected to the circuit through wires;

[0009] The developing bias circuit unit is used to independently provide a single developing bias to the drum circuit unit;

[0010] The developing roller and the powder feeding roller in the toner drum circuit unit are arranged in parallel and connected to the developing bias of the developing bias circuit unit. The powder feeding roller circuit is also connected in series with a voltage stabilizing diode for reducing the developing bias so that a potential difference is formed between the developing roller and the powder feeding roller to facilitate the powder feeding roller to effectively feed powder.

[0011] Furthermore, the developing bias circuit unit comprises:

[0012] an alternating voltage source;

[0013] An inductive element having an input coil and an output coil, connected to the alternating voltage source through the input coil and forming an output voltage after induction by the output coil;

[0014] The two ends of the output coil are connected to a first diode for capturing the positive voltage peak, the first diode is connected in series with a second diode for capturing the negative voltage peak, and the second diode directly outputs the developing bias provided by the developing bias circuit unit to the toner drum circuit unit. Through the series connection principle of the first diode and the second diode, the final output voltage is the sum of the positive voltage peak output voltage and the negative voltage peak output voltage.

[0015] Furthermore, the lower end of the first diode is connected to the lower end of the output coil, and the upper end of the first diode is also connected to one end of a first capacitor, and the other end of the first capacitor is connected to the upper end of the output coil; the front end of the second diode is also connected to the upper end of the output coil through the first capacitor, and the rear end of the second diode is also connected to one end of a second capacitor, and the other end of the second capacitor is connected to the lower end of the output coil.

[0016] Furthermore, a third capacitor is provided between the upper end and the lower end of the output coil.

[0017] Furthermore, the other end of the second capacitor is also grounded.

[0018] Furthermore, the toner drum circuit unit also includes a powder scraper connected in parallel with the powder feeding roller, and the powder scraper is connected to the lower end of the voltage regulator diode and is used to reduce the developing bias, so that a potential difference is formed between the developing roller and the powder scraper, which facilitates the powder scraper to repel carbon powder and increase the charge of carbon powder particles on the developing roller.

[0019] Furthermore, the powder discharging scraper is connected in parallel with the powder feeding roller and then grounded.

[0020] A printer comprises the above-mentioned control circuit for increasing the potential difference between a developing roller and a powder feeding roller.

[0021] The beneficial effects of the present invention are:

[0022] In the present invention, a single independent developing bias is provided to the drum circuit unit through the developing bias circuit unit, and a power supply mode of a power supply voltage is adopted. Aiming at the narrow space in the printer, the circuit connection structure between the developing roller and the powder feeding roller in the printer is simplified, the installation of the production process is convenient, the reliability of the product is effectively improved, and the production cost of the product is reduced.

[0023] Moreover, the powder feeding roller circuit in the toner drum circuit unit is also connected in series with a voltage stabilizing diode for reducing the developing bias voltage, so that a potential difference is formed between the developing roller and the powder feeding roller to facilitate the effective powder feeding of the powder feeding roller, improve the powder feeding quality and efficiency of the powder feeding roller, and effectively improve the utilization rate of carbon powder.

[0024] At the same time, a powder scraper connected in parallel with the powder feeding roller is also provided on the toner drum circuit unit, and the powder scraper is connected to the lower end of the voltage-stabilizing diode, and at the same time, a potential difference is formed between the developing roller and the powder scraper to reduce the developing bias, so that an electric potential difference is formed between the developing roller and the powder scraper, so that the powder scraper can repel toner and increase the charge of toner particles on the developing roller. Since the potential of the powder scraper is lower than that of the developing roller, the toner can be repelled, which can prevent the toner from sticking to the surface of the powder scraper during the printing process and can also prevent the toner from flying. The powder scraper can make the toner charge more sufficient by rubbing the toner, improve the utilization rate of the toner, and avoid defects such as bottom ash. In turn, the developing quality of the developing roller is improved and toner is saved, so as to achieve continuous and refined control of the developing process and effectively improve the quality of the final printing effect of the paper on the printer. Moreover, the powder scraper and the powder feed roller are connected in parallel to reduce the current passing through the powder feed roller, thereby reducing the charge it carries, reducing the amount of toner attracted per unit area, and further reducing the amount of toner transferred to the developing roller. This reduces the amount of toner used per unit printing area of ​​each sheet of paper while ensuring that the printing quality and reading effect are not reduced, thereby achieving the goals of energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram in the prior art;

[0026] Figure 2 is a schematic diagram of the circuit structure of the first embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the circuit structure of the second embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0030] Embodiment 1

[0031] A control circuit for increasing the potential difference between the developing roller and the powder feeding roller, such as Figure 2 As shown, the powder feeding device used in the printer includes a developing bias circuit unit 1 and a toner cartridge circuit unit 2. The developing bias circuit unit 1 is arranged in the body of the printer. The developing bias circuit unit 1 provides a developing bias to the toner cartridge circuit unit 2. The toner cartridge circuit unit 2 includes a developing roller 20 and a powder feeding roller 21. Both ends of the developing roller 20 and the powder feeding roller 21 are connected to the circuit via wires, respectively.

[0032] Continue as Figure 2 As shown, the developing bias circuit unit 1 is independently provided with a single developing bias to the drum circuit unit. The developing bias circuit unit 1 includes an alternating voltage source 3 and an induction element 4. The induction element 4 has an input coil 40 and an output coil 41. The input coil 40 is connected to the alternating voltage source 3, and an output voltage is formed after being induced by the output coil 41. The two ends of the output coil 41 are connected with a first diode D1 for capturing a positive voltage peak, and the first diode D1 is connected in series with a second diode D2 for capturing a negative voltage peak. The second diode D2 directly outputs the developing bias provided by the developing bias circuit unit 1 to the drum circuit unit 2. Through the series connection principle of the first diode D1 and the second diode D2, the final output voltage is the sum of the positive voltage peak output voltage and the negative voltage peak output voltage.

[0033] Continue as Figure 2As shown, the developing roller 20 and the powder feeding roller 21 in the toner drum circuit unit 2 are arranged in parallel and connected to the developing bias of the developing bias circuit unit 1. The powder feeding roller 21 circuit is also connected in series with a voltage regulator diode 22 for reducing the developing bias so that a potential difference is formed between the developing roller 20 and the powder feeding roller 21 to facilitate the effective powder feeding of the powder feeding roller, and the rear end of the powder feeding roller 21 is grounded.

[0034] Continue as Figure 2 As shown, the lower end of the first diode D1 is connected to the lower end of the output coil 41, and the upper end of the first diode D1 is also connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is connected to the upper end of the output coil 41; the front end of the second diode pair is also connected to the upper end of the output coil 41 through the first capacitor C1, and the rear end of the second diode D2 is also connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the lower end of the output coil 41 and grounded; a third capacitor C3 is also provided between the upper and lower ends of the output coil 41.

[0035] A single, independent developing bias is provided to the drum circuit unit through the developing bias circuit unit, and a power supply mode of a power supply voltage is adopted. Aiming at the narrow space in the printer, the circuit connection structure between the developing roller 20 and the powder feeding roller 21 in the printer is simplified, which is convenient for the installation of the production process, effectively improving the reliability of the product and reducing the production cost of the product. Moreover, the powder feeding roller 21 circuit in the drum circuit unit 2 is also connected in series with a voltage regulator diode 22 for reducing the developing bias, so that a potential difference is formed between the developing roller 20 and the powder feeding roller 21, which facilitates the effective powder feeding of the powder feeding roller 21, improves the powder feeding quality and powder feeding efficiency of the powder feeding roller 21, and effectively improves the utilization rate of carbon powder.

[0036] Embodiment 2

[0037] like Figure 3As shown, the difference between this embodiment and the first embodiment is that the toner cartridge circuit unit 2 also includes a powder scraper 23 connected in parallel with the powder feeding roller 21, and the powder scraper 23 is connected in parallel with the powder feeding roller 21 and then grounded, and the powder scraper 23 is connected to the lower end of the voltage-stabilizing diode 22 and is used to reduce the developing bias, so that a potential difference is formed between the developing roller 20 and the powder scraper 23, so that the powder scraper 23 can repel carbon powder and increase the charge of carbon powder particles on the developing roller 20, thereby further improving the developing quality of the developing roller 20 and saving carbon powder, realizing continuous and refined control of the developing process, and effectively improving the quality of the final printing effect of the paper on the printer. Since the potential of the powder scraper 23 is lower than that of the developing roller 20, it will repel toner, preventing the toner from sticking to the surface of the powder scraper 23 during the printing process and preventing the toner from flying around; the powder scraper 23 can make the toner more charged by rubbing the toner, thereby improving the toner utilization rate and avoiding defects such as bottom ash; thereby improving the development quality of the developing roller 20 and saving toner, achieving continuous and refined control of the development process, and effectively improving the quality of the final printing effect of the paper on the printer.

[0038] At the same time, the powder scraper 23 and the powder feeding roller 21 are connected in parallel to reduce the current passing through the powder feeding roller 21, thereby reducing the charge carried, reducing the amount of toner attracted per unit area, and further reducing the amount of toner transferred to the developing roller 20. This reduces the amount of toner used per unit printing area of ​​each sheet of paper while ensuring that the printing quality and reading effect are not reduced, thereby achieving energy saving and environmental protection.

[0039] In the description of the present invention, it should be noted that the terms "upper", "lower", "front" and "rear" etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0040] The above-described embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. All equivalent changes made based on the shape, structure and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control circuit for increasing the potential difference between a developing roller and a powder feeding roller, applied to powder feeding of a printer, comprising a developing bias circuit unit and a toner drum circuit unit, wherein the developing bias circuit unit is arranged in the printer body, and the developing bias circuit unit provides a developing bias to the toner drum circuit unit, wherein the toner drum circuit unit comprises a developing roller and a powder feeding roller, and the two ends of the developing roller and the powder feeding roller are respectively connected to the circuit through wires; characterized in that: The developing bias circuit unit is used to independently provide a single developing bias to the drum circuit unit; The developing roller and the powder feeding roller in the toner drum circuit unit are arranged in parallel and connected to the developing bias of the developing bias circuit unit. The powder feeding roller circuit is also connected in series with a voltage stabilizing diode for reducing the developing bias so that a potential difference is formed between the developing roller and the powder feeding roller to facilitate the powder feeding roller to effectively feed powder. The developing bias circuit unit comprises: an alternating voltage source; an inductive element having an input coil and an output coil, connected to the alternating voltage source through the input coil and forming an output voltage after induction by the output coil; The two ends of the output coil are connected to a first diode for capturing a positive voltage peak, the first diode is connected in series with a second diode for capturing a negative voltage peak, the second diode directly outputs the developing bias provided by the developing bias circuit unit to the drum circuit unit, through the series connection principle of the first diode and the second diode, the final output voltage is the sum of the positive voltage peak output voltage and the negative voltage peak output voltage; The toner drum circuit unit also includes a powder scraper connected in parallel with the powder feeding roller. The powder scraper is connected to the lower end of the voltage-stabilizing diode and is used to reduce the developing bias voltage, thereby forming an electric potential difference between the developing roller and the powder scraper, facilitating the powder scraper to repel carbon powder and increase the charge of carbon powder particles on the developing roller.

2. A control circuit for increasing the potential difference between the developing roller and the powder feeding roller according to claim 1, characterized in that: The lower end of the first diode is connected to the lower end of the output coil, and the upper end of the first diode is also connected to one end of a first capacitor, and the other end of the first capacitor is connected to the upper end of the output coil; the front end of the second diode is also connected to the upper end of the output coil through the first capacitor, and the rear end of the second diode is also connected to one end of a second capacitor, and the other end of the second capacitor is connected to the lower end of the output coil.

3. A control circuit for increasing the potential difference between the developing roller and the powder feeding roller according to claim 1, characterized in that: A third capacitor is also arranged between the upper end and the lower end of the output coil.

4. A control circuit for increasing the potential difference between the developing roller and the powder feeding roller according to claim 2, characterized in that: The other end of the second capacitor is also grounded.

5. A control circuit for increasing the potential difference between the developing roller and the powder feeding roller according to claim 1, characterized in that: The powder discharging scraper is connected in parallel with the powder feeding roller and then grounded.

6. A printer, characterized in that: A control circuit for increasing the potential difference between a developing roller and a powder feeding roller as described in any one of claims 1 to 5.

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