Developing apparatus, laser printer and toner Anti-sticking method
By vibrating the squeegee or creating an alternating electric field in the laser printer, the problem of toner sticking to the squeegee is solved, improving image quality and the lifespan of the developing unit.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- XIAMEN HANIN CO LTD
- Filing Date
- 2025-05-28
- Publication Date
- 2026-06-18
AI Technical Summary
In existing laser printers, toner remains and adheres to the doctor blade for extended periods, leading to image formation defects and a shortened lifespan for the developing unit.
Toner adhesion is prevented by vibrating the regulated squeegee during non-image formation periods or by creating an alternating electric field between the developing roller and the regulated squeegee.
It improves image printing quality and extends the lifespan of the developing unit, preventing toner from remaining on the doctor blade and melting due to heat.
Smart Images
Figure CN2025097797_18062026_PF_FP_ABST
Abstract
Description
A developing apparatus, a laser printer, and a method for preventing toner sticking. Technical Field
[0001] This application relates to the field of laser printing, specifically to a developing apparatus, a laser printer, and a method for preventing toner sticking. Background Technology
[0002] In existing technology, laser printers include an exposure unit, a photosensitive drum, a developing unit, a transfer unit, a paper tray, a paper feed path, a fixing unit, and a paper exit. The developing unit generally includes a housing and within it a developing roller, a doctor blade, and a supply roller. The housing contains a toner container for storing toner. The supply roller rubs the toner together with the developing roller to impart a positive or negative charge to the toner. The doctor blade limits the thickness of the toner layer adsorbed on the surface of the developing roller. The developing roller lays the toner onto the photosensitive drum according to the latent image to form an image. During laser printer use, toner that remains near the doctor blade for an extended period is heated and adheres to the doctor blade. When this residue on the doctor blade clumps together and comes into contact with the toner layer on the developing roller surface, the toner layer thickness at that location may not reach the target thickness. This results in striped defects in the image formed on the printing paper, reducing print quality and, in severe cases, requiring repair or even scrapping of the developing unit. Summary of the Invention
[0003] The purpose of this application is to overcome the aforementioned defects or problems in the prior art and to provide a developing apparatus, a laser printer, and a toner anti-sticking method, which can, to a certain extent, prevent toner from sticking to the doctor blade, thereby improving image printing quality and the service life of the developing apparatus.
[0004] To achieve the above objectives, the following technical solution is adopted:
[0005] The first technical solution relates to a developing apparatus, comprising: a developing roller and a regulating doctor blade; the regulating doctor blade is used to limit the thickness of charged toner adhering to the developing roller; the developing apparatus further comprises a driving unit, the driving unit causing the regulating doctor blade to vibrate to perform an anti-sticking action for toner.
[0006] The second technical solution is based on the first technical solution, wherein the developing device further includes a housing and a supply roller, the developing roller, the regulating doctor blade and the supply roller are located inside the housing, the housing is provided with a toner hopper for storing toner, and the supply roller is used to supply the toner in the toner hopper to the developing roller.
[0007] The third technical solution is based on the first technical solution, wherein the driving unit includes a vibration generator, and the vibration generator is connected to the regulating scraper.
[0008] The fourth technical solution is based on the third technical solution, wherein the driving unit includes a voltage control module, which is configured to control the rotation of the developing roller during non-image formation periods and to form an alternating electric field between the developing roller and the regulating blade, wherein the electric field force of the alternating electric field is directed toward the developing roller.
[0009] The fifth technical solution is based on the fourth technical solution, wherein the voltage control module is configured to apply an alternating voltage to the developing roller and / or the regulating blade to form the alternating electric field during non-image formation periods.
[0010] The sixth technical solution is based on the fifth technical solution, wherein the voltage control module includes a first circuit electrically connected to the developing roller, a second circuit connected to the regulating doctor blade, and a switching circuit for controlling the on / off state of the first circuit and the second circuit.
[0011] The seventh technical solution is based on the sixth technical solution, wherein the switching circuit includes a first switching circuit and a second switching circuit, the first switching circuit is used to control the circuit to be turned on or off, and the second switching circuit is used to control the circuit to be turned on or off.
[0012] The eighth technical solution is based on the fourth technical solution, wherein the driving unit further includes a voltage carrier, the regular scraper is located between the voltage carrier and the developing roller, and the voltage control module is configured to apply an alternating voltage to the developing roller and / or the voltage carrier to form the alternating electric field during non-image formation periods.
[0013] The ninth technical solution relates to a laser printer, which includes a developing device as described in any one of the first to seventh technical solutions.
[0014] The tenth technical solution relates to a toner anti-sticking method, which performs toner anti-sticking action by vibrating a squeegee during non-image forming periods.
[0015] The eleventh technical solution is based on the tenth technical solution, wherein, during non-image formation, the toner anti-sticking action is performed by vibrating the regulating squeegee during vibration generation.
[0016] The twelfth technical solution is based on the tenth technical solution, wherein, during non-image formation, the toner anti-sticking action is performed by controlling the rotation of the developing roller and forming an alternating electric field between the developing roller and the regulating blade, and the direction of the electric field force of the alternating electric field is towards the developing roller.
[0017] The thirteenth technical solution is based on the twelfth technical solution, wherein, during non-image formation, the alternating electric field is formed by applying an alternating voltage to the developing roller and / or the regulating blade.
[0018] The fourteenth technical solution is based on the thirteenth technical solution, wherein during the toner anti-sticking action, the frequency of the alternating voltage applied by the driving unit to the developing roller and / or the regulating blade is 50Hz-500Hz, and the application duration is 10ms-100ms.
[0019] The fifteenth technical solution is based on any one of the tenth to fourteenth technical solutions, wherein when the toner anti-sticking action is performed and the developing action is to be performed, the end time of the toner anti-sticking action and the start time of the developing action are at least 5ms apart.
[0020] Compared with existing technologies, the above solution has the following beneficial effects:
[0021] By setting up a drive unit to perform toner anti-sticking action during non-imaging periods, the squeegee vibrates, causing the toner gathered near the squeegee to loosen due to vibration. This improves the toner flow efficiency near the squeegee and prevents some toner from remaining on the squeegee surface for a long time and melting due to heating. This can, to a certain extent, prevent toner from sticking to the squeegee, thereby improving image printing quality and the lifespan of the developing unit. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments, the accompanying drawings used are briefly described below:
[0023] Figure 1 is a schematic diagram of the structure of the laser printer provided in this embodiment;
[0024] Figure 2 is a schematic diagram of the developing apparatus provided in the first embodiment of this application;
[0025] Figure 3 is a schematic diagram of the developing apparatus provided in the second embodiment of this application;
[0026] Figure 4 is a schematic diagram of the developing apparatus provided in the fourth embodiment of this application.
[0027] Key reference numerals in the attached drawings: 1. Laser printer; 11. Exposure unit; 12. Photosensitive drum; 13. Developing unit; 14. Transfer unit; 15. Paper tray; 16. Fixing unit; 17. Paper exit; 131. Toner tray; 132. Developing roller; 133. Doctor blade; 134. Feed roller; 135. Vibration generator; 136. Voltage control module; 137. Voltage carrier. Detailed Implementation
[0028] Unless otherwise specified, the term "image" in the claims and description includes, but is not limited to, text, patterns, tables, symbols, etc.
[0029] Unless otherwise specified in the claims and description, the term "toner" refers to a collection of fine powder particles used to form an image, and its color is not limited to black, but may also be other colors.
[0030] Unless otherwise specified in the claims and description, the term "alternating voltage" refers to a voltage whose magnitude changes periodically, and the term "alternating electric field" refers to an electric field whose electric field strength changes periodically.
[0031] In the claims and description, unless otherwise specified, the terms "comprising," "having," and variations thereof mean "including but not limited to," and the term "having" means that a subsequent technical feature is part of a preceding technical feature.
[0032] Unless otherwise specified, the terms “first,” “second,” or “third,” etc., in the claims and description are used to distinguish different objects and not to describe a particular order.
[0033] The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings.
[0034] First implementation method:
[0035] As shown in Figure 1, the laser printer 1 is composed of an exposure device 11 (which serves as the exposure mechanism), a photosensitive drum 12, a developing device 13, a transfer device 14, a paper tray 15, a paper feed path, a fixing device 16, and a paper output port 17. The exposure device 11 is located at the top of the laser printer 1 and is composed of a laser light source or various optical systems that emit laser light. It generates laser light corresponding to each pixel of the image based on the image data. The surface of the photosensitive drum 12 is uniformly charged after being charged by a charger. The exposure mechanism selectively illuminates the surface of the photosensitive drum 12, changing the charge state of the exposed positions on the surface of the photosensitive drum 12, thereby allowing the photosensitive drum 12 to obtain a latent image corresponding to the image.
[0036] The developing unit 13 is located below the exposure unit 11 and includes a plurality of components that are detachably mounted relative to the laser printer 1. As shown in FIG2, the developing unit 13 includes a housing and a developing roller 132, a doctor blade 133, and a supply roller 134 located within the housing. The housing has a toner container 131 for storing toner; the supply roller 134 supplies toner to the developing roller 132 and rubs the toner together with the developing roller 132 to make the toner carry a positive or negative charge. The charged toner approaches the developing roller 132 under the electric field force between the supply roller 134 and the developing roller 132 and is adsorbed onto the surface of the developing roller 132 under electrostatic action; in this embodiment, the toner used is non-magnetic toner; the doctor blade 133 contacts the surface of the developing roller 132 or the developing roller 132... The surfaces of the developing roller 132 maintain a certain distance. During the rotation of the developing roller 132, the developing roller 132 carries the adsorbed toner to the regulating blade 133. Some of the toner is removed from the developing roller 132 due to the obstruction of the regulating blade 133, thereby limiting the thickness of the toner layer adsorbed on the surface of the developing roller 132. In this embodiment, the regulating blade 133 is made of an elastic conductive material, preferably a thin metal sheet. The developing roller 132 is used to lay the toner onto the photosensitive drum 12 according to the latent image to form an image, that is, to perform the developing action.
[0037] As shown in Figure 2, during the developing process, both the developing roller 132 and the supply roller 134 rotate counterclockwise. A DC voltage is applied to the developing roller 132, the supply roller 134, and the regulating blade 133 to create a voltage difference between the developing roller 132 and the supply roller 134 and the regulating blade 133. For example, a positive voltage of 300V is applied to the developing roller 132, and a positive voltage of 500V is applied to the supply roller 134 and the regulating blade 133. This creates an electric field between the supply roller 134 and the developing roller 132, and between the regulating blade 133 and the developing roller 132, which brings the positively charged toner closer to the developing roller 132, thereby transferring the charged toner to the developing roller 132. It should be noted that when different types of toner are used, the DC voltage applied to the developing roller 132, the supply roller 134 and the regulating blade 133 will be adjusted accordingly. Since the developing process of the laser printer 1 is a mature existing technology, the relevant parameter configuration and execution steps are known to those skilled in the art and will not be described in detail here.
[0038] The transfer unit 14 is located directly below the developing unit 13. The transfer unit 14 includes a transfer roller and a transfer current control mechanism. The transfer roller is configured to hold the printing paper relative to the photosensitive drum. By applying a transfer current to the transfer roller, the toner on the photosensitive drum 12 is transferred to the printing paper, thereby forming an image on the printing paper. The paper tray 15 is located at the lower part of the laser printer 1 and includes a paper feed cassette that holds the printing paper and a paper feed roller that feeds the printing paper from the paper feed cassette. The paper feed path is a transport path that transports the printing paper fed from the paper tray 15. Several transfer rollers are appropriately configured to transport the printing paper from the paper tray 15 to the paper output port 17. The fixing unit 16 includes a fixing roller that is heated by a heat source and a pressure roller that can pressurize the fixing roller to heat the toner transferred to the printing paper, melting it and fixing it onto the printing paper. The paper output port 17 is located at the downstream end of the paper feeding path of the laser printer 1, and a paper discharge roller for discharging the printed paper to the outside is provided in the paper output port.
[0039] As shown in Figure 2, the developing apparatus 13 of this embodiment also includes a driving unit, which includes a vibration generator 135. The vibration generator 135 is connected to the squeegee 133. The vibration generator 135 can be a vibrating motor, an ultrasonic generator, or other device capable of causing an object to vibrate. It should be noted that the connection between the vibration generator 135 and the squeegee 133 can be direct or indirect, as long as the vibration generator 135 can act on the squeegee 133 to cause the squeegee 133 to vibrate. The vibration generator 135 is configured to vibrate the squeegee 133 during non-image forming periods to perform toner anti-sticking action on the squeegee 133. The non-image forming periods include the preparation time before printing, the finishing time after printing, the time for printing blank areas, and the interval time between printing pages when printing multiple pages. It should be noted that the toner anti-sticking action can be selectively performed during some non-image forming periods, rather than performing the toner anti-sticking action during every non-image forming period. For example, the toner anti-sticking action can be performed once every 10 pages printed. Preferably, the duration of each toner anti-sticking action is 10ms-100ms. During non-image forming periods, the squeegee 133 is vibrated by the vibration generator 135, causing the toner gathered near the squeegee 133 to loosen due to vibration, thereby improving the toner flow efficiency near the squeegee 133 and preventing some toner from remaining on the surface of the squeegee 133 for a long time and being heated and melted. This can, to a certain extent, prevent toner from sticking to the squeegee 133, thereby improving image printing quality and the service life of the developing device 13.
[0040] Preferably, when the toner anti-sticking action is followed by the developing action, the time interval between the end of the toner anti-sticking action and the start of the developing action is at least 5ms. Providing sufficient transition time between the toner anti-sticking action and the developing action allows the doctor blade 133 to recover from its vibrating state to a stable state, thus preventing uneven toner layer thickness on the developing roller 132 due to vibration of the doctor blade 133.
[0041] Second implementation method:
[0042] In this embodiment, the developing apparatus 13 has a structure similar to that of the developing apparatus 13 in the first embodiment. However, unlike the first embodiment, this embodiment achieves toner anti-sticking action of the doctor blade 133 by applying an alternating electric field between the developing roller 132 and the doctor blade 133 while controlling the rotation of the developing roller 132. As shown in FIG3, the developing apparatus 13 of this embodiment further includes a driving unit, which includes a voltage control module 136. The voltage control module 136 is configured to control the rotation of the developing roller 132 during non-image forming periods and apply an alternating voltage to the developing roller 132 and / or the doctor blade 133 to form an alternating electric field between the developing roller 132 and the doctor blade 133. The direction of the electric field force of the alternating electric field is towards the developing roller. Specifically, alternating voltages can be applied simultaneously to the developing roller 132 and the regulating blade 133, controlling the voltage amplitude difference or the phase difference between them to create an alternating voltage difference between the developing roller 132 and the regulating blade 133, thereby forming an alternating electric field between them; or, alternating voltages can be applied to the developing roller 132 while keeping the voltage on the regulating blade 133 constant, thus creating an alternating voltage difference between them; or, alternating voltages can be applied to the regulating blade 133 while keeping the voltage on the developing roller 132 constant, resulting in an alternating voltage difference between them, thus forming an alternating electric field. The alternating voltage can be generated by devices capable of producing alternating voltages, such as PWM controllers, AC power supplies, pulse generators, and switching circuits. The alternating voltage is preferably a sine wave, square wave, or sawtooth wave. The voltage control module 136 can be integrated into the control mainboard of the laser printer 1, or it can be set on a separate control circuit board. Preferably, during the toner anti-sticking operation, the alternating frequency of the voltage difference between the developing roller 132 and the doctor blade 133 is set to 50Hz-500Hz, the amplitude of the voltage difference is set to 100V-400V, and the duration is set to 10ms-100ms.
[0043] When an alternating electric field is formed between the developing roller 132 and the doctor blade 133, the electric field force is directed towards the developing roller. Consequently, the force exerted by the toner between the developing roller 132 and the doctor blade 133 on the developing roller 132 periodically increases and decreases. When the force increases, the toner adsorbed on the developing roller 132 is less likely to detach due to the obstruction of the doctor blade 133. At this time, more toner passes through the gap between the developing roller 132 and the doctor blade 133 as the developing roller 132 rotates, and more toner passes through the developing roller 132 per unit time. The gap between the developing roller 132 and the doctor blade 133 will compress the doctor blade 133, causing it to shift away from the developing roller 132. When the force of the toner relative to the developing roller 132 decreases, the toner adsorbed on the developing roller 132 is more easily removed from the developing roller 132 due to the obstruction of the doctor blade 133. At this time, less toner will pass through the gap between the developing roller 132 and the doctor blade 133 as the developing roller 132 rotates. The compression of the doctor blade 133 by the toner decreases, causing the doctor blade 133 to shift towards the developing roller 132 under the action of its own elasticity. Therefore, when an alternating electric field is formed between the developing roller 132 and the doctor blade 133, the amount of toner passing through the gap between the developing roller 132 and the doctor blade 133 will periodically increase and decrease as the developing roller 132 rotates. The pressure of the toner on the doctor blade 133 will also change periodically, which will cause the doctor blade 133 to periodically shift its position, thus causing the doctor blade 133 to vibrate.
[0044] In this embodiment, the driving unit is configured to form an alternating electric field between the developing roller 132 and the squeegee 133 during non-image forming periods, thereby causing the squeegee 133 to vibrate to perform a toner anti-sticking action. The non-image forming periods include pre-printing preparation time, post-printing finishing time, time for printing blank areas, and the interval between printed pages when printing multiple pages. It should be noted that the toner anti-sticking action can be selectively performed during some non-image forming periods, rather than every single non-image forming period. For example, a toner anti-sticking action can be performed every 10 pages printed. Preferably, the duration of each toner anti-sticking action is 10ms-100ms. During non-image forming periods, an alternating electric field is formed between the developing roller 132 and the squeegee 133 to cause the squeegee 133 to vibrate. This causes the toner gathered near the squeegee 133 to be loosened by the vibration, thereby improving the toner flow efficiency near the squeegee 133 and preventing some toner from remaining on the surface of the squeegee 133 for a long time and being heated and melted. This can, to a certain extent, prevent toner from sticking to the squeegee 133, thereby improving image printing quality and the service life of the developing device 13.
[0045] Preferably, when the toner anti-sticking action is followed by the developing action, the time interval between the end of the toner anti-sticking action and the start of the developing action is at least 5ms. Providing sufficient transition time between the toner anti-sticking action and the developing action allows the doctor blade 133 to recover from its vibrating state to a stable state, thus preventing uneven toner layer thickness on the developing roller 132 due to vibration of the doctor blade 133.
[0046] Third implementation method:
[0047] Based on the second embodiment, the voltage control module 136 in this embodiment uses a switching circuit to apply an alternating voltage to the developing roller 132 and / or the regulating blade 133 to create an alternating electric field between the developing roller 132 and the regulating blade 133. Specifically, the voltage control module 136 includes a first circuit, a second circuit, and a switching circuit; the first circuit is connected to the developing roller 132, and outputs a first voltage to the developing roller 132 when the first circuit is on; the second circuit is connected to the regulating blade 133, and outputs a second voltage to the regulating blade 133 when the second circuit is on. A switching circuit is provided to control the on / off state of the first and second circuits. The switching circuit can be a single circuit that simultaneously controls the on / off state of both the first and second circuits; alternatively, it can be configured as a first and second switching circuit with independent control, where the first switching circuit controls the on / off state of the first circuit, and the second switching circuit controls the on / off state of the second circuit.
[0048] When toner anti-sticking is required, a switching circuit controls the first and / or second circuits to be turned on or off at a certain frequency, so that the voltage output by the first and / or second circuits is an alternating voltage in the form of a square wave. That is, an alternating voltage is applied to the developing roller 132 and / or the doctor blade 133, thereby forming an alternating electric field between the developing roller 132 and the doctor blade 133. Preferably, during the toner anti-sticking operation, the switching frequency of the switching circuit is set to 50Hz-500Hz, and the duration is set to 10ms-100ms. Preferably, the voltage difference between the first voltage and the second voltage is 100V-400V. In this embodiment, the first voltage is the same as the voltage required by the developing roller 132 during the developing operation, and the second voltage is the same as the voltage required by the regulating blade 133 during the developing operation. For example, the first voltage is a positive voltage of 300V and the second voltage is a positive voltage of 500V, so that the voltage control module 136 can provide the required voltage to the developing roller 132 and the regulating blade 133 during the developing operation, and can also provide the required voltage to the developing roller 132 and the regulating blade 133 during the toner anti-sticking operation.
[0049] Fourth implementation method:
[0050] In this embodiment, the developing apparatus 13 has a similar structure to that in the second embodiment. The difference is that the driving unit in this embodiment further includes a voltage carrier 137, as shown in FIG. 4. The regulating blade 133 is located between the voltage carrier 137 and the developing roller 132. The voltage control module 136 is configured to apply an alternating voltage to the developing roller 132 and / or the voltage carrier 137 during non-image forming periods to perform toner anti-sticking action on the regulating blade 133. Specifically, the voltage carrier 137 is supported by a conductive material, preferably a metal sheet, metal wire, or metal rod. By simultaneously applying alternating voltages to the developing roller 132 and the voltage carrier 137, and controlling the voltage amplitude difference or the phase difference between them, an alternating voltage difference can be formed between the developing roller 132 and the voltage carrier 137, thereby forming an alternating electric field between them; or, by applying alternating voltages to the developing roller 132 while keeping the voltage on the voltage carrier 137 constant, an alternating voltage difference can be formed between the developing roller 132 and the voltage carrier 137, thereby forming an alternating electric field between them; or, by applying alternating voltages to the voltage carrier 137 while keeping the voltage on the developing roller 132 constant, an alternating voltage difference can be formed between the developing roller 132 and the voltage carrier 137, thereby forming an alternating electric field between them. The alternating voltage can be generated by devices that can form alternating voltages, such as PWM controllers, AC power supplies, pulse generators, and switching circuits. The alternating voltage is preferably a sine wave, square wave, or sawtooth wave. Preferably, during the toner anti-sticking operation, the alternating frequency of the voltage difference between the developing roller 132 and the doctor blade 133 is set to 50Hz-500Hz, the amplitude of the voltage difference is set to 100V-400V, and the duration is set to 10ms-100ms.
[0051] Since the doctor blade 133 is positioned between the developing roller 132 and the voltage carrier 137, when an alternating electric field is formed between the developing roller 132 and the voltage carrier 137, it is equivalent to an alternating electric field being formed between the developing roller 132 and the doctor blade 133. Consequently, the force exerted by the toner between the developing roller 132 and the doctor blade 133 on the developing roller 132 periodically increases and decreases. When the force of the toner on the developing roller 132 increases, the toner adsorbed on the developing roller 132 is less likely to detach from the developing roller 132 due to the obstruction of the doctor blade 133. At this time, more toner will pass between the developing roller 132 and the doctor blade 133 as the developing roller 132 rotates. The gap between the developing roller 132 and the doctor blade 133 is 33. When more toner passes through the gap between the developing roller 132 and the doctor blade 133 per unit time, it will squeeze the doctor blade 133, causing the doctor blade 133 to deviate away from the developing roller 132. When the force of the toner relative to the developing roller 132 decreases, the toner adsorbed on the developing roller 132 is more likely to be removed from the developing roller 132 due to the obstruction of the doctor blade 133. At this time, less toner will pass through the gap between the developing roller 132 and the doctor blade 133 as the developing roller 132 rotates. The compression of the doctor blade 133 by the toner decreases, causing the doctor blade 133 to deviate towards the developing roller 132 under the action of its own elasticity. Therefore, when an alternating electric field is formed between the developing roller 132 and the doctor blade 133, the amount of toner passing through the gap between the developing roller 132 and the doctor blade 133 will periodically increase and decrease as the developing roller 132 rotates. The pressure of the toner on the doctor blade 133 will also change periodically, which will cause the doctor blade 133 to periodically shift its position, thus causing the doctor blade 133 to vibrate.
[0052] In this embodiment, the driving unit is configured to form an alternating electric field between the developing roller 132 and the squeegee 133 during non-image forming periods, thereby causing the squeegee 133 to vibrate to perform a toner anti-sticking action. The non-image forming periods include pre-printing preparation time, post-printing finishing time, time for printing blank areas, and the interval between printed pages when printing multiple pages. It should be noted that the toner anti-sticking action can be selectively performed during some non-image forming periods, rather than every single non-image forming period. For example, a toner anti-sticking action can be performed every 10 pages printed. Preferably, the duration of each toner anti-sticking action is 10ms-100ms. During non-image forming periods, an alternating electric field is formed between the developing roller 132 and the squeegee 133 to cause the squeegee 133 to vibrate. This causes the toner gathered near the squeegee 133 to be loosened by the vibration, thereby improving the toner flow efficiency near the squeegee 133 and preventing some toner from remaining on the surface of the squeegee 133 for a long time and being heated and melted. This can, to a certain extent, prevent toner from sticking to the squeegee 133, thereby improving image printing quality and the service life of the developing device 13.
[0053] Preferably, when the toner anti-sticking action is followed by the developing action, the time interval between the end of the toner anti-sticking action and the start of the developing action is at least 5ms. Providing sufficient transition time between the toner anti-sticking action and the developing action allows the doctor blade 133 to recover from its vibrating state to a stable state, thus preventing uneven toner layer thickness on the developing roller 132 due to vibration of the doctor blade 133.
[0054] Fifth implementation method:
[0055] This embodiment provides a laser printer. The laser printer 1 includes an exposure device 11, a photosensitive drum 12, a developing device 13, a transfer device 14, a paper tray 15, a paper feed path, a fixing device 16, and a paper output port 17. The developing device 13 is any of the developing devices described in the first to fourth embodiments.
[0056] Sixth implementation method:
[0057] This embodiment provides a toner anti-sticking method. Specifically, during non-image forming periods, a vibration generator vibrates the squeegee to perform toner anti-sticking action. As shown in Figure 2, a vibration generator 135 connected to the squeegee 133 is provided in the developing apparatus 132. The vibration generator 135 can be a vibration motor, ultrasonic generator, or other device capable of causing vibration. It should be noted that the connection between the vibration generator 135 and the squeegee 133 can be direct or indirect, as long as the vibration generator 135 acts on the squeegee 133 to cause the squeegee 133 to vibrate. The non-image forming periods include the preparation time before printing, the finishing time after printing, the time for printing blank areas, and the interval between printed pages when printing multiple pages. It should be noted that the toner anti-sticking action can be selectively performed during some non-image forming periods, rather than performing the toner anti-sticking action during every non-image forming period. For example, the toner anti-sticking action can be performed once every 10 pages printed. Preferably, the duration of each toner anti-sticking action is 10ms-100ms. During non-image forming periods, the squeegee 133 is vibrated by the vibration generator 135, causing the toner gathered near the squeegee 133 to loosen due to vibration, thereby improving the toner flow efficiency near the squeegee 133 and preventing some toner from remaining on the surface of the squeegee 133 for a long time and being heated and melted. This can, to a certain extent, prevent toner from sticking to the squeegee 133, thereby improving image printing quality and the service life of the developing device 13.
[0058] Preferably, when the toner anti-sticking action is followed by the developing action, the time interval between the end of the toner anti-sticking action and the start of the developing action is at least 5ms. Providing sufficient transition time between the toner anti-sticking action and the developing action allows the doctor blade 133 to recover from its vibrating state to a stable state, thus preventing uneven toner layer thickness on the developing roller 132 due to vibration of the doctor blade 133.
[0059] Seventh implementation method:
[0060] This embodiment provides a toner anti-sticking method. During non-image forming periods, the developing roller 132 is controlled to rotate, and an alternating electric field is formed on the developing roller 132 and / or the squeegee 133 to cause the squeegee to vibrate, thereby performing a toner anti-sticking action. The electric field force of the alternating electric field is directed towards the developing roller. Specifically, an alternating electric field is formed between the developing roller 132 and the squeegee 133 by applying an alternating voltage to the developing roller 132 and / or the squeegee 133, or a voltage carrier 137 is provided on the side of the squeegee 133 facing away from the developing roller 132, and an alternating electric field is formed between the developing roller 132 and the squeegee 133 by applying an alternating voltage to the developing roller 132 and / or the voltage carrier 137. The voltage carrier 137 is supported by a conductive material, preferably a metal sheet, metal wire, or metal rod.
[0061] To create an alternating electric field between the developing roller 132 and the regulating blade 133 by applying an alternating voltage to the developing roller 132 and / or the regulating blade 133, an alternating voltage can be applied simultaneously to both the developing roller 132 and the regulating blade 133. By controlling the difference in voltage amplitude or the phase difference between the two, an alternating voltage difference can be created between the developing roller 132 and the regulating blade 133, thereby forming an alternating electric field between them. Alternatively, an alternating voltage can be applied to the developing roller 132... By applying an alternating voltage while keeping the voltage on the doctor blade 133 constant, an alternating voltage difference can be formed between the developing roller 132 and the doctor blade 133, thereby creating an alternating electric field between them. Alternatively, by applying an alternating voltage to the doctor blade 133 while keeping the voltage on the developing roller 132 constant, an alternating voltage difference can be created between them, thus forming an alternating electric field. The alternating voltage can be generated by devices capable of generating alternating voltages, such as a PWM controller, AC power supply, pulse generator, or switching circuit. The alternating voltage is preferably a sine wave, square wave, or sawtooth wave. The voltage control module 136 can be integrated into the control mainboard of the laser printer 1 or can be set on a separate control circuit board. Preferably, during the toner anti-sticking operation, the alternating frequency of the voltage difference between the developing roller 132 and the regulating doctor blade 133 is set to 50Hz-500Hz, the amplitude of the voltage difference is set to 100V-400V, and the duration is set to 10ms-100ms.
[0062] To create an alternating electric field between the developing roller 132 and the regulating doctor blade 133 by applying an alternating voltage to the developing roller 132 and / or the voltage carrier 137, an alternating voltage difference can be formed between the developing roller 132 and the voltage carrier 137 by simultaneously applying alternating voltages to both, controlling the voltage amplitude difference or the phase difference between them; or, by applying an alternating voltage to the developing roller 132 and / or the voltage carrier 137, an alternating electric field can be formed between them. By applying an alternating voltage to the developing roller 132 while keeping the voltage on the voltage carrier 137 constant, an alternating voltage difference can be formed between the developing roller 132 and the voltage carrier 137, thereby creating an alternating electric field between them. Alternatively, by applying an alternating voltage to the voltage carrier 137 while keeping the voltage on the developing roller 132 constant, an alternating voltage difference can be formed between the developing roller 132 and the voltage carrier 137, thereby creating an alternating electric field between them. The alternating voltage can be generated by devices capable of generating alternating voltages, such as a PWM controller, AC power supply, pulse generator, or switching circuit. The alternating voltage is preferably a sine wave, square wave, or sawtooth wave. Preferably, during the toner removal operation, the alternating frequency of the voltage difference between the developing roller 132 and the doctor blade 133 is set to 50Hz-500Hz, the amplitude of the voltage difference is set to 100V-400V, and the duration is set to 10ms-100ms.
[0063] When an alternating electric field is formed between the developing roller 132 and the doctor blade 133, the electric field force is directed towards the developing roller. Consequently, the force exerted by the toner between the developing roller 132 and the doctor blade 133 on the developing roller 132 periodically increases and decreases. When the force increases, the toner adsorbed on the developing roller 132 is less likely to detach due to the obstruction of the doctor blade 133. At this time, more toner passes through the gap between the developing roller 132 and the doctor blade 133 as the developing roller 132 rotates, and more toner passes through the developing roller 132 per unit time. The gap between the developing roller 132 and the doctor blade 133 will compress the doctor blade 133, causing it to shift away from the developing roller 132. When the force of the toner relative to the developing roller 132 decreases, the toner adsorbed on the developing roller 132 is more easily removed from the developing roller 132 due to the obstruction of the doctor blade 133. At this time, less toner will pass through the gap between the developing roller 132 and the doctor blade 133 as the developing roller 132 rotates. The compression of the doctor blade 133 by the toner decreases, causing the doctor blade 133 to shift towards the developing roller 132 under the action of its own elasticity. Therefore, when an alternating electric field is formed between the developing roller 132 and the doctor blade 133, the amount of toner passing through the gap between the developing roller 132 and the doctor blade 133 will periodically increase and decrease as the developing roller 132 rotates. The pressure of the toner on the doctor blade 133 will also change periodically, which will cause the doctor blade 133 to periodically shift its position, thus causing the doctor blade 133 to vibrate.
[0064] In this embodiment, an alternating electric field is formed between the developing roller 132 and the squeegee 133 during non-image forming periods, thereby causing the squeegee 133 to vibrate and perform toner anti-sticking action. These non-image forming periods include pre-printing preparation time, post-printing finishing time, time for printing blank areas, and the interval between printed pages in multi-page printing. It should be noted that the toner anti-sticking action can be selectively performed during some non-image forming periods, rather than every single non-image forming period. For example, it can be performed once every 10 pages printed. Preferably, the duration of each toner anti-sticking action is 10ms-100ms. During non-image forming periods, an alternating electric field is formed between the developing roller 132 and the squeegee 133 to cause the squeegee 133 to vibrate. This causes the toner gathered near the squeegee 133 to be loosened by the vibration, thereby improving the toner flow efficiency near the squeegee 133 and preventing some toner from remaining on the surface of the squeegee 133 for a long time and being heated and melted. This can, to a certain extent, prevent toner from sticking to the squeegee 133, thereby improving image printing quality and the service life of the developing device 13.
[0065] Preferably, when the toner anti-sticking action is followed by the developing action, the time interval between the end of the toner anti-sticking action and the start of the developing action is at least 5ms. Providing sufficient transition time between the toner anti-sticking action and the developing action allows the doctor blade 133 to recover from its vibrating state to a stable state, thus preventing uneven toner layer thickness on the developing roller 132 due to vibration of the doctor blade 133.
[0066] The description of the above specification and embodiments is used to explain the scope of protection of this application, but does not constitute a limitation on the scope of protection of this application.
Claims
1. A developing apparatus, comprising: A developing roller and a regulating doctor blade; the regulating doctor blade is used to limit the thickness of charged toner adhering to the developing roller; characterized in that: the developing apparatus further includes a driving unit, the driving unit causing the regulating doctor blade to vibrate to perform a toner anti-sticking action.
2. The developing apparatus according to claim 1, characterized in that: The developing apparatus further includes a housing and a supply roller. The developing roller, the regulating doctor blade, and the supply roller are located inside the housing. The housing is provided with a toner hopper for storing toner, and the supply roller is used to supply the toner in the toner hopper to the developing roller.
3. The developing apparatus according to claim 1, characterized in that: The drive unit includes a vibration generator, which is connected to the regulating scraper.
4. The developing apparatus according to claim 1, characterized in that: The drive unit includes a voltage control module configured to control the rotation of the developing roller during non-image formation periods and to form an alternating electric field between the developing roller and the caliper blade, the electric field force of the alternating electric field being directed toward the developing roller.
5. The developing apparatus according to claim 4, characterized in that: The voltage control module is configured to apply an alternating voltage to the developing roller and / or the regulating blade during non-image formation periods to form the alternating electric field.
6. The developing apparatus according to claim 5, characterized in that: The voltage control module includes a first circuit electrically connected to the developing roller, a second circuit connected to the regulating doctor blade, and a switching circuit for controlling the on / off state of the first circuit and the second circuit.
7. The developing apparatus according to claim 6, characterized in that: The switching circuit includes a first switching circuit and a second switching circuit. The first switching circuit is used to control the circuit to be turned on or off, and the second switching circuit is used to control the circuit to be turned on or off.
8. The developing apparatus according to claim 4, characterized in that: The drive unit further includes a voltage carrier, the regular scraper is located between the voltage carrier and the developing roller, and the voltage control module is configured to apply an alternating voltage to the developing roller and / or the voltage carrier to form the alternating electric field during non-image formation periods.
9. A laser printer, characterized in that, The laser printer includes the developing apparatus as described in any one of claims 1-8.
10. A method for preventing toner sticking, characterized in that: Toner anti-sticking action is achieved by vibrating the regulated squeegee during non-image formation periods.
11. The toner anti-sticking method according to claim 10, characterized in that: During non-image formation, the toner anti-sticking action is performed by vibrating the regulated squeegee during vibration generation.
12. The toner anti-sticking method according to claim 10, characterized in that: During non-image formation, the toner anti-sticking action is performed by controlling the rotation of the developing roller and forming an alternating electric field between the developing roller and the regulating blade, with the electric field force of the alternating electric field directed toward the developing roller.
13. The toner anti-sticking method according to claim 12, characterized in that: During non-image formation periods, the alternating electric field is formed by applying an alternating voltage to the developing roller and / or the regulating blade.
14. The toner anti-sticking method according to claim 12, characterized in that: During the toner anti-sticking action, the frequency of the alternating voltage applied by the drive unit to the developing roller and / or the regulating blade is 50Hz-500Hz, and the duration of application is 10ms-100ms.
15. The toner anti-sticking method according to any one of claims 10-14, characterized in that: When the toner anti-sticking action is performed and the developing action is to be performed, the time interval between the end time of the toner anti-sticking action and the start time of the developing action shall be at least 5ms.