Developing device, laser printer and toner anti-sticking method

Abstract

The invention discloses a developing device, a laser printer and a toner anti-sticking method. The developing device comprises a developing roller and a regulation scraper, the regulation scraper is used for limiting the thickness of the charged toner attached to the developing roller; the developing device further includes a driving unit that vibrates the regulation blade to perform a toner adhesion prevention operation. The toner anti-sticking action is executed in the non-imaging period, so that the regulation scraper vibrates, the toner gathered near the regulation scraper is loosened due to vibration, the toner circulation efficiency near the regulation scraper is improved, and part of toner is prevented from being detained on the surface of the regulation scraper for a long time to be heated and melted; the toner can be prevented from being adhered to the regulation scraper to a certain extent, so that the image printing quality is improved, and the service life of the developing device is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser printing, in particular to a developing device, a laser printer and a toner anti-sticking method. BACKGROUND

[0002] In the prior art, a laser printer comprises an exposure device, a photosensitive drum, a developing device, a transfer device, a paper bin, a paper feeding path, a fixing device and a paper outlet. The developing device generally comprises a housing and a developing roller, a regulating blade and a supply roller located in the housing. The housing is provided with a toner bin for storing toner. The supply roller is used to rub the toner with the developing roller to make the toner carry positive or negative electricity. The regulating blade is used to limit the thickness of the toner layer adsorbed on the surface of the developing roller. The developing roller is used to lay the toner on the photosensitive drum according to a latent image to form an image. During the use of the laser printer, the toner staying near the regulating blade for a long time is heated and adheres to the regulating blade. When the adhering substance on the regulating blade adheres into a block and contacts the toner layer on the surface of the developing roller, the toner layer thickness at this position is difficult to reach the target thickness, which further causes the image formed on the printing paper to have a striped defect, reduces the image printing quality, and in severe cases, the developing device needs to be repaired or even scrapped. SUMMARY

[0003] The present application aims to overcome the above-mentioned defects or problems in the background art, and provide a developing device, a laser printer and a toner anti-sticking method, which can avoid toner adhering to the regulating blade to some extent, so as to improve the image printing quality and the service life of the developing device.

[0004] To achieve the above-mentioned purpose, the following technical solutions are adopted:

[0005] The first technical solution relates to a developing device, comprising a developing roller and a regulating blade. The regulating blade is used to limit the thickness of the toner carrying electricity attached to the developing roller. The developing device further comprises a driving unit, which makes the regulating blade vibrate to perform a toner anti-sticking action.

[0006] The second technical solution is based on the first technical solution, wherein the developing device further comprises a housing and a supply roller. The developing roller, the regulating blade and the supply roller are located in the housing. The housing is provided with a toner bin for storing toner. The supply roller is used to supply the toner in the toner bin to the developing roller.

[0007] The third technical solution is based on the first technical solution, wherein the driving unit comprises a vibration generator connected with the regulating blade.

[0008] The fourth technical solution is based on the third technical solution, wherein the driving unit comprises a voltage control module configured to control rotation of the developing roller during non-image forming time and form an alternating electric field between the developing roller and the doctor blade, the electric field force of the alternating electric field being directed towards 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 on the developing roller and / or the doctor blade to form the alternating electric field during non-image forming time.

[0010] The sixth technical solution is based on the fifth technical solution, wherein the voltage control module comprises a first circuit electrically connected to the developing roller, a second circuit connected to the doctor blade, and a switch circuit for controlling on-off of the first circuit and the second circuit.

[0011] The seventh technical solution is based on the sixth technical solution, wherein the switch circuit comprises a first switch circuit for controlling on-off of the circuit and a second switch circuit for controlling on-off of the second circuit.

[0012] The eighth technical solution is based on the fourth technical solution, wherein the driving unit further comprises a voltage carrier, the doctor blade is located between the voltage carrier and the developing roller, and the voltage control module is configured to apply an alternating voltage on the developing roller and / or the voltage carrier to form the alternating electric field during non-image forming time.

[0013] The ninth technical solution is based on any one of the above technical solutions, wherein the developing device further comprises a stirring roller located close to the doctor blade.

[0014] The tenth technical solution relates to a laser printer comprising the developing device according to any one of the first to ninth technical solutions.

[0015] The eleventh technical solution relates to a toner anti-sticking method, wherein the toner anti-sticking action is performed by vibrating the doctor blade during non-image forming time.

[0016] The twelfth technical solution is based on the eleventh technical solution, wherein the toner anti-sticking action is performed by vibrating the doctor blade by a vibration generator during non-image forming time.

[0017] The thirteenth technical solution is based on the eleventh technical solution, wherein the toner anti-sticking action is performed by controlling rotation of the developing roller and forming an alternating electric field between the developing roller and the doctor blade during non-image forming time, the electric field force of the alternating electric field being directed towards the developing roller.

[0018] The fourteenth technical solution is based on the thirteenth technical solution, wherein during the non-image forming period, the alternating electric field is formed by applying an alternating voltage on the developing roller and / or the regulating blade.

[0019] The fifteenth technical solution is based on the fourteenth technical solution, wherein during the toner anti-sticking action, the frequency of the alternating voltage applied on the developing roller and / or the regulating blade by the driving unit is 50-500Hz, and the application duration is 10-100ms.

[0020] The sixteenth technical solution is based on any one of the eleventh to fifteenth technical solutions, wherein when the developing action is to be performed after the toner anti-sticking action, the end time of the toner anti-sticking action and the start time of the developing action are at least 5ms apart.

[0021] Compared with the prior art, the above technical solutions have the following beneficial effects:

[0022] By setting the driving unit, the toner anti-sticking action is performed during the non-imaging period, so that the regulating blade vibrates, thereby loosening the toner gathered near the regulating blade due to vibration, improving the toner flow efficiency near the regulating blade, preventing part of the toner from being heated and melted due to long-term residence on the surface of the regulating blade, and avoiding toner sticking to the regulating blade to a certain extent, thereby improving the image printing quality and the service life of the developing device. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments, the following briefly introduces the drawings needed to be used:

[0024] Figure 1 The structure schematic diagram of the laser printer provided for the present embodiment;

[0025] Figure 2 The structure schematic diagram of the developing device provided for the first embodiment of the present application Figure 1 ;

[0026] Figure 3 The structure schematic diagram of the developing device provided for the first embodiment of the present application Figure 2 ;

[0027] Figure 4 The structure schematic diagram of the developing device provided for the second embodiment of the present application;

[0028] Figure 5 The structure schematic diagram of the developing device provided for the fourth embodiment of the present application.

[0029] Explanation of main reference signs:

[0030] 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; 138. Agitator roller Detailed Implementation

[0031] Unless otherwise specified, the term "image" in the claims and description includes, but is not limited to, text, patterns, tables, symbols, etc.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings.

[0037] First implementation method:

[0038] like Figure 1 As shown, 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 irradiates 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.

[0039] The developing device 13 is located below the exposure device 11 and includes a plurality of components that are detachably mounted relative to the laser printer 1. As shown in Figure 2 The developing device 13 includes a housing and a developing roller 132, a regulating doctor blade 133 and a supply roller 134 located in the housing. The housing has a toner cartridge 131 for storing toner, and the supply roller 134 is used to supply toner to the developing roller 132, which rubs the toner to make the toner carry positive or negative electricity. The charged toner is attracted to the surface of the developing roller 132 under the electric field force between the supply roller 134 and the developing roller 132. In this embodiment, the toner used is non-magnetic toner. The regulating doctor blade 133 is in contact with or at a certain distance from the surface of the developing roller 132. During the rotation of the developing roller 132, the developing roller 132 carries the adsorbed toner to the regulating doctor blade 133. Part of the toner is separated from the developing roller 132 due to the obstruction of the regulating doctor blade 133, thereby limiting the thickness of the toner layer adsorbed on the surface of the developing roller 132. In this embodiment, the regulating doctor blade 133 is made of an elastic conductive material, preferably a metal sheet. The developing roller 132 is used to lay the toner on the photosensitive drum 12 according to the latent image to form an image, i.e., to perform a developing action.

[0040] As shown in Figure 2 During the developing action, the developing roller 132 and the supply roller 134 rotate counterclockwise. A direct current voltage is applied to the developing roller 132, the supply roller 134 and the regulating doctor blade 133 to make the developing roller 132 have a voltage difference relative to the supply roller 134 and the regulating doctor 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 doctor blade 133, so that the electric field force between the supply roller 134 and the developing roller 132 and between the regulating doctor blade 133 and the developing roller 132 makes the positively charged toner close to the developing roller 132, thereby realizing the transfer of the charged toner to the developing roller 132. It should be noted that when the type of toner used is different, the direct current voltage applied to the developing roller 132, the supply roller 134 and the regulating doctor blade 133 will be adjusted accordingly. Since the developing of the laser printer 1 is a mature existing technology, the relevant parameter configurations and execution steps are known to those skilled in the art, and will not be described here.

[0041] The transfer device 14 is located directly below the developing device 13, and includes a transfer roller configured to sandwich the print paper with respect to the photosensitive drum, and a transfer current control mechanism. The transfer roller transfers the toner on the photosensitive drum 12 to the print paper by applying a transfer current to the transfer roller, thereby forming an image on the print paper. The paper cassette 15 is located at the lower portion of the laser printer 1, and includes a paper supply cassette that stores the print paper, and a paper feed roller that feeds the print paper from the paper supply cassette. The paper feed path is a conveying path that conveys the print paper fed from the paper cassette 15, and is configured with a plurality of conveying rollers to convey the print paper from the paper cassette 15 to the paper outlet 17. The fixing device 16 includes a fixing roller heated by a heating source, and a pressure roller that can apply pressure to the fixing roller, and the like, to heat and melt the toner transferred to the print paper, thereby fixing the toner to the print paper. The paper outlet 17 is provided at the most downstream portion of the paper feed path of the laser printer 1, and is configured with a paper discharge roller that discharges the print paper to the outside.

[0042] As shown in Figure 2 The developing device 13 of the present embodiment further includes a driving unit, which includes a vibration generator 135 connected to the regulating blade 133. The vibration generator 135 can be a vibration motor, an ultrasonic generator, or the like, which can vibrate an object. It should be noted that the connection between the vibration generator 135 and the regulating blade 133 can be direct or indirect, as long as the vibration generator 135 can act on the regulating blade 133 to vibrate the regulating blade 133. The vibration generator 135 is configured to vibrate the regulating blade 133 during a non-image forming period to perform a toner anti-sticking action of the regulating blade 133. The non-image forming period includes a preparation time before printing, a finishing time after printing, a time for printing a blank area, and an interval time between pages during multi-page printing. It should be noted that the toner anti-sticking action can be performed selectively during part of the non-image forming period, and does not need to be performed during every non-image forming period. For example, the toner anti-sticking action can be performed once every 10 pages. Preferably, the duration of each toner anti-sticking action is 10 ms to 100 ms. During the non-image forming period, the vibration generator 135 vibrates the regulating blade 133, which loosens the toner accumulated near the regulating blade 133 due to the vibration, thereby improving the flow efficiency of the toner near the regulating blade 133, preventing part of the toner from staying on the surface of the regulating blade 133 for a long time and being heated and melted, and thus avoiding toner sticking to the regulating blade 133 to some extent, thereby improving the image printing quality and the service life of the developing device 13.

[0043] As shown in Figure 3As shown, a stirring roller 138 is also arranged near the regulating blade 133, and the stirring roller 138 rotates in the opposite direction of the developing roller 131. The rotation of the stirring roller 138 can further improve the flow efficiency of the toner near the regulating blade 133, and prevent the toner from staying on the surface of the regulating blade 133 for a long time and being heated and melted. Preferably, the supply roller 134 is adapted to be applied with the same voltage as the regulating blade 133, so that when the alternating electric field is formed between the developing roller 131 and the regulating blade 133, the alternating electric field is also formed between the developing roller 131 and the supply roller 134, so as to change the alternating electric field force of the toner between the developing roller 131 and the supply roller 134, and further promote the flow of the toner.

[0044] Preferably, when the toner anti-sticking action is performed before the developing action, the end time of the toner anti-sticking action and the start time of the developing action are at least 5 ms apart. Sufficient transition time is provided between the toner anti-sticking action and the developing action, which is beneficial to the regulating blade 133 to recover from the vibration state to the stable state, so as to avoid the uneven thickness of the toner layer on the developing roller 132 due to the vibration of the regulating blade 133.

[0045] Second embodiment:

[0046] In the embodiment, the developing device 13 has a similar structure as the developing device 13 in the first embodiment, and the difference between the two is that, in the embodiment, the toner anti-sticking action of the regulating blade 133 is performed by applying an alternating electric field between the developing roller 132 and the regulating blade 133 while controlling the rotation of the developing roller 132. As shown in FIG. 6, the toner anti-sticking action of the regulating blade 133 is performed by applying an alternating electric field between the developing roller 132 and the regulating blade 133 while controlling the rotation of the developing roller 132. Figure 3As shown, the developing device 13 of the embodiment further comprises a driving unit, which comprises a voltage control module 136 configured to control the rotation of the developing roller 132 during the non-image forming period, and to apply an alternating voltage on the developing roller 132 and / or the regulating doctor blade 133 to form an alternating electric field between the developing roller 132 and the regulating doctor blade 133, the electric field force of the alternating electric field being directed towards the developing roller. Specifically, the alternating voltage can be applied on both the developing roller 132 and the regulating doctor blade 133, the voltage amplitudes of which are controlled to have a difference, or the phases of which are controlled to have a phase difference, so as to form an alternating voltage difference between the developing roller 132 and the regulating doctor blade 133, and further form the alternating electric field between the developing roller 132 and the regulating doctor blade 133; or the alternating voltage is applied on the developing roller 132 while the voltage on the regulating doctor blade 133 is kept constant, so as to form an alternating voltage difference between the developing roller 132 and the regulating doctor blade 133, and further form the alternating electric field between the developing roller 132 and the regulating doctor blade 133; or the alternating voltage is applied on the regulating doctor blade 133 while the voltage on the developing roller 132 is kept constant, so as to form an alternating voltage difference between the developing roller 132 and the regulating doctor blade 133, and further form the alternating electric field between the developing roller 132 and the regulating doctor blade 133. The alternating voltage can be formed by devices capable of forming alternating voltage such as PWM controller, AC power supply, pulse generator, switching circuit, etc., and the alternating voltage is preferably a sine wave, a square wave or a sawtooth wave. The voltage control module 136 can be integrated on the control mainboard of the laser printer 1, or can be separately arranged on an additional control circuit board. Preferably, during the anti-sticking action of the toner, the alternating transformation 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.

[0047] 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.

[0048] 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.

[0049] Preferably, when the toner anti-sticking action is followed by the developing action, the end time of the toner anti-sticking action and the start time of the developing action are at least 5 ms apart. The sufficient transition time is provided between the toner anti-sticking action and the developing action, which is conducive to regulating the doctor blade 133 to recover from the vibrating state to the stable state, so as to avoid the uneven thickness of the toner layer on the developing roller 132 due to the vibration of the doctor blade 133.

[0050] Third embodiment:

[0051] On the basis of the second embodiment, the voltage control module 136 in the present embodiment adopts the switching circuit mode to apply alternating voltage on the developing roller 132 and / or the doctor blade 133 to form alternating electric field between the developing roller 132 and the doctor 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 the first voltage to the developing roller 132 when the first circuit is turned on; the second circuit is connected to the doctor blade 133, and outputs the second voltage to the doctor blade 133 when the second circuit is turned on. The switching circuit is provided to control the turn-on or turn-off of the first circuit and the second circuit. The switching circuit can be only one, which controls the turn-on or turn-off of the first circuit and the second circuit at the same time; or the switching circuit can be the first switching circuit and the second switching circuit which are independently controlled, wherein the first switching circuit is used to control the turn-on or turn-off of the first circuit, and the second switching circuit is used to control the turn-on or turn-off of the second circuit.

[0052] When the toner anti-sticking action is needed, the first circuit and / or the second circuit are controlled to turn on or turn off by the switching circuit at a certain frequency, so that the voltage output by the first circuit and / or the second circuit is alternating voltage in the form of square wave, that is, alternating voltage is applied on the developing roller 132 and / or the doctor blade 133, and then alternating electric field can be formed between the developing roller 132 and the doctor blade 133. Preferably, the frequency of the switching circuit is set to 50 Hz-500 Hz, and the duration is set to 10 ms-100 ms during the toner anti-sticking action. Preferably, the voltage difference between the first voltage and the second voltage is 100 V-400 V. In the present embodiment, the first voltage is the same as the voltage required by the developing roller 132 when the developing action is performed, and the second voltage is the same as the voltage required by the doctor blade 133 when the developing action is performed, for example, the first voltage is 300 V positive voltage, and the second voltage is 500 V positive voltage, so that the voltage control module 136 can provide the required voltage for the developing roller 132 and the doctor blade 133 when the developing action is performed, and can also provide the required voltage for the developing roller 132 and the doctor blade 133 when the toner anti-sticking action is performed.

[0053] Fourth embodiment:

[0054] In the present embodiment, the developing device 13 has a similar structure to the developing device 13 in the second embodiment, except that the driving unit in the present embodiment further comprises a voltage carrier 137, as shown in Figure 4 The voltage control module 136 is configured to apply an alternating voltage on the developing roller 132 and / or the voltage carrier 137 during the non-image forming period to perform the toner anti-sticking action of the regulating blade 133. Specifically, the voltage carrier 137 is supported by an electrically conductive material, preferably a metal sheet, a metal wire or a metal rod. By simultaneously applying an alternating voltage on the developing roller 132 and the voltage carrier 137, the voltage amplitude of the two is controlled to have a difference, or the two are controlled to have a phase difference, so as to form an alternating voltage difference between the developing roller 132 and the voltage carrier 137, and further form an alternating electric field between the developing roller 132 and the voltage carrier 137; or an alternating voltage is applied on the developing roller 132 while keeping the voltage on the voltage carrier 137 constant, so as to form an alternating voltage difference between the developing roller 132 and the voltage carrier 137, and further form an alternating electric field between the developing roller 132 and the voltage carrier 137; or an alternating voltage is applied on the voltage carrier 137 while keeping the voltage on the developing roller 132 constant, so as to form an alternating voltage difference between the developing roller 132 and the voltage carrier 137, and further form an alternating electric field between the developing roller 132 and the voltage carrier 137. The alternating voltage can be formed by devices capable of forming an alternating voltage, such as a PWM controller, an alternating power supply, a pulse generator, a switching circuit, etc., and the alternating voltage is preferably a sine wave, a square wave or a sawtooth wave. Preferably, during the toner anti-sticking action, the alternating transformation frequency of the voltage difference between the developing roller 132 and the regulating blade 133 is set to 50 Hz-500 Hz, the amplitude of the voltage difference is set to 100 V-400 V, and the duration is set to 10 ms-100 ms.

[0055] When the alternating electric field is formed between the developing roller 132 and the voltage carrier 137, i.e. the alternating electric field is formed between the developing roller 132 and the regulating doctor blade 133, the force of the toner between the developing roller 132 and the regulating doctor blade 133 relative to the developing roller 132 is periodically increased and decreased. When the force of the toner between the developing roller 132 and the regulating doctor blade 133 relative to the developing roller 132 is increased, the toner adsorbed on the developing roller 132 is less likely to be separated from the developing roller 132 due to the obstruction of the regulating doctor blade 133. At this time, more toner will pass through the gap between the developing roller 132 and the regulating doctor blade 133 along with the rotation of the developing roller 132, and more toner passing through the gap between the developing roller 132 and the regulating doctor blade 133 per unit time will press the regulating doctor blade 133, causing the regulating doctor blade 133 to be offset away from the developing roller 132. When the force of the toner between the developing roller 132 and the regulating doctor blade 133 relative to the developing roller 132 is decreased, the toner adsorbed on the developing roller 132 is more likely to be separated from the developing roller 132 due to the obstruction of the regulating doctor blade 133. At this time, less toner will pass through the gap between the developing roller 132 and the regulating doctor blade 133 along with the rotation of the developing roller 132, and the toner pressing the regulating doctor blade 133 is reduced, causing the regulating doctor blade 133 to be offset towards the developing roller 132 under the action of its own elasticity. Thus, when the alternating electric field is formed between the developing roller 132 and the regulating doctor blade 133, the amount of toner passing through the gap between the developing roller 132 and the regulating doctor blade 133 along with the rotation of the developing roller 132 will be periodically increased and decreased, and the toner pressing the regulating doctor blade 133 will also be periodically changed, thereby causing the regulating doctor blade 133 to be periodically offset in position, i.e. causing the regulating doctor blade 133 to vibrate.

[0056] In the embodiment, the driving unit is configured to form an alternating electric field between the developing roller 132 and the doctor blade 133 during a non-image forming period, so as to vibrate the doctor blade 133 to perform the anti-sticking action of toner on the doctor blade 133. The non-image forming period includes a preparation time before printing, a finishing time after printing, a time for printing a blank area, and an interval time between pages during multi-page printing. It should be noted that the anti-sticking action of toner can be performed in some non-image forming periods, and the anti-sticking action of toner does not need to be performed in every non-image forming period. For example, the anti-sticking action of toner can be performed once every 10 pages. Preferably, the duration of the anti-sticking action of toner is 10 ms to 100 ms. During the non-image forming period, the alternating electric field formed between the developing roller 132 and the doctor blade 133 vibrates the doctor blade 133, so that the toner gathered near the doctor blade 133 is loosened due to the vibration, thereby improving the flow efficiency of the toner near the doctor blade 133, preventing part of the toner from being heated and melted for a long time on the surface of the doctor blade 133, and thus avoiding the toner from being stuck on the doctor blade 133 to a certain extent, so as to improve the image printing quality and the service life of the developing device 13.

[0057] Preferably, when the developing action is performed after the anti-sticking action of toner, the end time of the anti-sticking action of toner and the start time of the developing action are at least 5 ms apart. Sufficient transition time is provided between the anti-sticking action of toner and the developing action, so as to facilitate the doctor blade 133 to recover from the vibration state to the stable state, thereby avoiding the uneven thickness of the toner layer on the developing roller 132 due to the vibration of the doctor blade 133.

[0058] Fifth embodiment:

[0059] The embodiment provides a laser printer, which includes an exposure device 11, a photosensitive drum 12, a developing device 13, a transfer device 14, a paper bin 15, a paper conveying path, a fixing device 16, and a paper outlet 17. The developing device 13 is any one of the developing devices described in the first embodiment to the fourth embodiment.

[0060] Sixth embodiment:

[0061] The embodiment provides an anti-sticking method of toner. Specifically, during a non-image forming period, the doctor blade is vibrated by a vibration generator to perform the anti-sticking action of toner. As shown in FIG. 6, the anti-sticking action of toner is performed during the non-image forming period. Figure 2As shown, the vibration generator 135 is connected to the regulation blade 133 in the developing device 132. The vibration generator 135 can be a vibration motor, an ultrasonic generator or other devices capable of vibrating the object. It should be noted that the connection between the vibration generator 135 and the regulation blade 133 can be direct or indirect, as long as the vibration generator 135 can act on the regulation blade 133 to make the regulation blade 133 vibrate. The non-image forming period includes the preparation time before printing, the arrangement time after printing, the time for printing blank area and the interval time between each printed page when printing multiple pages. It should be noted that the toner anti-sticking action can be performed in part of the non-image forming period, and the toner anti-sticking action does not need to be performed in each non-image forming period. For example, the toner anti-sticking action can be performed once every 10 printed pages. Preferably, the duration of each toner anti-sticking action is 10-100 ms. During the non-image forming period, the vibration generator 135 vibrates the regulation blade 133, so that the toner gathered near the regulation blade 133 is loosened due to the vibration, thereby improving the toner flow efficiency near the regulation blade 133, preventing part of the toner from staying on the surface of the regulation blade 133 for a long time and being heated and melted, and thus avoiding the toner from sticking to the regulation blade 133 to a certain extent, so as to improve the image printing quality and the service life of the developing device 132.

[0062] Preferably, when the developing action is performed after the toner anti-sticking action, the end time of the toner anti-sticking action and the start time of the developing action are at least 5 ms apart. A sufficient transition time is provided between the toner anti-sticking action and the developing action, which is beneficial for the regulation blade 133 to recover from the vibration state to the stable state, so as to avoid the uneven thickness of the toner layer on the developing roller 132 due to the vibration of the regulation blade 133.

[0063] Seventh embodiment:

[0064] The embodiment provides a toner anti-sticking method. The toner anti-sticking action is performed by controlling the rotation of the developing roller 132 during the non-image forming period, and vibrating the regulation blade by forming an alternating electric field on the developing roller 132 and / or the regulation blade 133. The electric field force direction of the alternating electric field is towards the developing roller. Specifically, the alternating electric field is formed between the developing roller 132 and the regulation blade 133 by applying an alternating voltage on the developing roller 132 and / or the regulation blade 133, or a voltage carrier 137 is arranged on the side of the regulation blade 133 away from the developing roller 132, and the alternating electric field is formed between the developing roller 132 and the regulation blade 133 by applying an alternating voltage on the developing roller 132 and / or the voltage carrier 137. The voltage carrier 137 is supported by a conductive material, which is preferably a metal sheet, a metal wire or a metal rod.

[0065] For applying the alternating voltage on the developing roller 132 and / or the regulating doctor blade 133 to form the alternating electric field between the developing roller 132 and the regulating doctor blade 133, the alternating voltage can be applied on the developing roller 132 and the regulating doctor blade 133 simultaneously, the voltage amplitude of the two is controlled to have a difference, or the phase difference of the two is controlled, that is, the voltage difference between the developing roller 132 and the regulating doctor blade 133 is formed to change alternately, and then the alternating electric field is formed between the developing roller 132 and the regulating doctor blade 133; or the alternating voltage is applied on the developing roller 132, and the voltage on the regulating doctor blade 133 is kept constant, that is, the voltage difference between the developing roller 132 and the regulating doctor blade 133 is formed to change alternately, and then the alternating electric field is formed between the developing roller 132 and the regulating doctor blade 133; or the alternating voltage is applied on the regulating doctor blade 133, and the voltage on the developing roller 132 is kept constant, that is, the voltage difference between the developing roller 132 and the regulating doctor blade 133 is formed to change alternately, and then the alternating electric field is formed between the developing roller 132 and the regulating doctor blade 133. The alternating voltage can be formed by devices capable of forming alternating voltage such as PWM controller, alternating power supply, pulse generator, switching circuit, etc., and the alternating voltage is preferably sine wave, square wave or sawtooth wave. The voltage control module 136 can be integrated on the control mainboard of the laser printer 1, or can be separately arranged on an additional control circuit board. Preferably, during the anti-sticking action of the toner, the alternating transformation 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.

[0066] For applying alternating voltage on the developing roller 132 and / or the voltage carrier 137 to form alternating electric field between the developing roller 132 and the regulating doctor blade 133, the alternating voltage can be applied on the developing roller 132 and the voltage carrier 137 simultaneously, the voltage amplitude of the two can be controlled to have a difference, or the two can be controlled to have a phase difference, i.e. the voltage difference between the developing roller 132 and the voltage carrier 137 is alternating, and then the alternating electric field is formed between the developing roller 132 and the voltage carrier 137; or the alternating voltage is applied on the developing roller 132 while the voltage on the voltage carrier 137 is kept constant, i.e. the voltage difference between the developing roller 132 and the voltage carrier 137 is alternating, and then the alternating electric field is formed between the developing roller 132 and the voltage carrier 137; or the alternating voltage is applied on the voltage carrier 137 while the voltage on the developing roller 132 is kept constant, i.e. the voltage difference between the developing roller 132 and the voltage carrier 137 is alternating, and then the alternating electric field is formed between the developing roller 132 and the voltage carrier 137. The alternating voltage can be formed by devices that can form alternating voltage, such as PWM controller, AC power supply, pulse generator, switching circuit, etc., and the alternating voltage is preferably sine wave, square wave or sawtooth wave. Preferably, during the powder removing action, the alternating transformation 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.

[0067] When the alternating electric field is formed between the developing roller 132 and the regulation blade 133, the force of the electric field of the alternating electric field is directed towards the developing roller, so the force of the toner between the developing roller 132 and the regulation blade 133 is periodically increased and decreased. When the force of the toner relative to the developing roller 132 is increased, the toner adsorbed on the developing roller 132 is less likely to be separated from the developing roller 132 due to the obstruction of the regulation blade 133. At this time, more toner passes through the gap between the developing roller 132 and the regulation blade 133 along with the rotation of the developing roller 132, and more toner passing through the gap between the developing roller 132 and the regulation blade 133 per unit time presses the regulation blade 133, so that the regulation blade 133 is deviated away from the developing roller 132. When the force of the toner relative to the developing roller 132 is decreased, the toner adsorbed on the developing roller 132 is more likely to be separated from the developing roller 132 due to the obstruction of the regulation blade 133. At this time, less toner passes through the gap between the developing roller 132 and the regulation blade 133 along with the rotation of the developing roller 132, and the toner presses the regulation blade 133 less, so that the regulation blade 133 is deviated towards the developing roller 132 under the action of its own elasticity. Thus, when the alternating electric field is formed between the developing roller 132 and the regulation blade 133, the amount of toner passing through the gap between the developing roller 132 and the regulation blade 133 along with the rotation of the developing roller 132 is periodically increased and decreased, and the toner presses the regulation blade 133 periodically, so that the regulation blade 133 is periodically deviated, i.e., vibrates.

[0068] In the embodiment, the alternating electric field is formed between the developing roller 132 and the regulation blade 133 during the non-image forming period, so that the regulation blade 133 vibrates to perform the toner anti-sticking action. The non-image forming period includes the preparation time before printing, the arrangement time after printing, the time for printing a blank area, and the interval time between pages during multi-page printing. It should be noted that the toner anti-sticking action can be performed during part of the non-image forming period, and the toner anti-sticking action does not need to be performed during each non-image forming period. For example, the toner anti-sticking action can be performed once every 10 pages. Preferably, the duration of each toner anti-sticking action is 10 ms to 100 ms. During the non-image forming period, the regulation blade 133 is vibrated by forming the alternating electric field between the developing roller 132 and the regulation blade 133, so that the toner gathered near the regulation blade 133 is loosened due to the vibration, thereby improving the flow efficiency of the toner near the regulation blade 133 and preventing part of the toner from being heated and melted due to long-term residence on the surface of the regulation blade 133. Thus, the toner can be prevented from adhering to the regulation blade 133 to some extent, so as to improve the image printing quality and the service life of the developing device 13.

[0069] Preferably, when the toner anti-sticking action is followed by the developing action, the end time of the toner anti-sticking action and the start time of the developing action are separated by at least 5 ms. The sufficient transition time is provided between the toner anti-sticking action and the developing action, which is conducive to regulating the squeegee 133 to return to the stable state from the vibrating state, so as to avoid the uneven thickness of the toner layer on the developing roller 132 due to the vibration of the squeegee 133.

[0070] The above description and the embodiment description are used to explain the protection scope of the present application, but do not constitute the limitation of the protection scope of the present 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. The developing apparatus according to any one of claims 1-8, characterized in that: The developing apparatus also includes a stirring roller located near the regulating scraper.

10. A laser printer, characterized in that, The laser printer includes a developing apparatus as described in any one of claims 1-9.

11. 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.

12. The toner anti-sticking method according to claim 11, characterized in that: During non-image formation, the toner anti-sticking action is performed by vibrating the regulated squeegee during vibration generation.

13. The toner anti-sticking method according to claim 11, 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.

14. The toner anti-sticking method according to claim 13, 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.

15. The toner anti-sticking method according to claim 13, 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.

16. The toner anti-sticking method according to any one of claims 11-15, 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.

Images