JP2009204993A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device which prevents stay of toner on the supply roller surface and image unevenness without enlargement. <P>SOLUTION: An air pump 33a is expanded and contracted by a cam 33b rotated interlocking with rotation of a developing roller 21, a toner supply roller 22 or a toner agitating conveying member 28 and forcibly feeds air to a blow pipe 32b. The air is fed through the blow pipe 32b to an air blow nozzle 31, blown off from each air blow hole 31a of the air blow nozzle 31, and blown to the toner in the vicinity of the toner supply roller 22, the developing roller 21, and the curved tip part 23a of a toner layer thickness regulating member 23. Thereby, the toner is efficiently loosened and favorably circulated by increase of the flowability, and stay of the toner in the vicinity of the toner layer thickness regulating member 23a of the toner layer thickness regulating member 23 is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a developing device used in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile machine.

  In this type of electrophotographic image forming apparatus, an electrostatic latent image is formed on the surface of the photosensitive drum, the electrostatic latent image on the surface of the photosensitive drum is developed with a developer, and a toner image is formed on the surface of the photosensitive drum. The toner image is transferred from the photosensitive drum to the recording paper, and the recording paper is heated and pressurized to fix the toner image on the recording paper. Further, since residual toner and residual charge remain on the surface of the photosensitive drum, the residual toner is removed by a cleaning device, and the residual charge is removed by a static eliminator.

  By the way, as a general developer for developing an electrostatic latent image on a photosensitive member, there are a one-component developer composed only of toner and a two-component developer composed of a mixture of toner and carrier. Since the one-component developer does not use a carrier, there is an advantage that a stirring mechanism for uniformly mixing the toner and the carrier becomes unnecessary, and the configuration of the developing device is simplified. For this reason, it is often used in small image forming apparatuses.

  In the developing method using a one-component developer, a thin layer of one-component developer (toner) is formed on the surface of the developing roller, and this thin layer is conveyed to a developing position facing the photosensitive drum as the developing roller rotates. Then, the electrostatic latent image on the surface of the photosensitive drum is developed. How to stably form a thin layer of developer (toner) having a uniform charge and layer thickness on the surface of the developing roller is important for obtaining good image quality.

  However, a one-component developer, that is, a toner, tends to lose fluidity as compared with a two-component developer obtained by mixing a toner and a carrier, and therefore, it is difficult to form a uniform toner thin layer on the surface of the developing roller. In many cases, this causes image unevenness.

As a method of ensuring the fluidity of the toner, a method of stirring the toner with a stirring blade is generally known. Further, in Patent Document 1, an air blowing nozzle and a pump for sending air to the nozzle are provided at the lower entrance of the toner bottle for replenishing toner, and the toner and air are mixed by blowing air into the toner in the bottle at the time of toner replenishment. However, a method for improving fluidity is disclosed.
Japanese Patent Laid-Open No. 4-143781

  However, in the case where the toner is stirred with a stirring blade in order to ensure the fluidity of the toner, there is a problem that the fluidity of the toner is adversely affected if the stirring time becomes long.

  In the developing device, when the toner is stirred for a long period of time, friction occurs between the toner, such as a stirring blade, a toner layer thickness regulating member, and a developing roller, and the toner temperature rises due to the frictional heat. The added external additive is buried in the toner particle surface, or the wax added as a fixing aid bleeds on the toner surface, the fluidity of the toner is significantly impaired, and the toner stays on the supply roller surface. As a result, a thin toner layer having a uniform layer thickness cannot be formed, and image unevenness occurs.

  Further, as in Patent Document 1, when air is supplied to the lower side of the toner bottle to give fluidity to the toner, it is necessary to supply a large amount of air from the lower side of the toner bottle. The equipment of was enlarged.

  Accordingly, the present invention has been made in view of the above-described conventional problems, and it is an object of the present invention to provide a developing device that prevents toner from staying on the surface of a supply roller and is free from image unevenness without increasing the size.

  In order to solve the above-described problems, a developing device of the present invention includes a developing roller that carries a layer of a one-component developer on the peripheral surface, a supply roller that supplies the one-component developer to the peripheral surface of the developing roller, and a developing roller. A layer thickness regulating member that regulates the layer thickness of the one-component developer on the circumferential surface, a developing roller, a supply roller, a layer thickness regulating member, and a developing tank that contains the one-component developer, In the developing device for visualizing the electrostatic latent image on the surface of the photosensitive drum with a one-component developer, an air supply unit is provided for supplying air to the toner supplied and conveyed by the supply roller.

  The air supply means includes a columnar nozzle arranged in parallel with the supply roller, and a pump for sending air to the nozzle, and the columnar nozzle has a plurality of air outlets facing the supply roller. Provided.

  Further, the pump sends air to the nozzle in conjunction with the rotation of the supply roller.

  Further, the layer thickness regulating member is interposed between the nozzle and the developing roller.

  Furthermore, the nozzle has an air outlet that faces both ends of the supply roller.

  The nozzle is made of a porous member having pores of 2 microns or less, and air is blown from the porous member.

  On the other hand, another developing device of the present invention comprises a developing roller carrying a layer of one-component developer on the peripheral surface, a supply roller for supplying the one-component developer to the peripheral surface of the developing roller, and a developing roller peripheral surface. Houses a layer thickness regulating member for regulating the layer thickness of the component developer, an agitating and conveying member for agitating the one component developer, a developing roller, a supply roller, a layer thickness regulating member, an agitating and conveying member, and the one component developer. An air supply means for supplying air to the toner stirred by the stirring and conveying member in a developing device having a developing tank and visualizing an electrostatic latent image on the surface of the photosensitive drum by a one-component developer on the peripheral surface of the developing roller It has.

  The agitation transport member is disposed in the vicinity of the supply roller and the layer thickness regulating member.

  Further, the air supply means includes a columnar nozzle arranged in parallel with the supply roller, and a pump for sending air to the nozzle, and a plurality of air outlets facing the stirring and conveying member in the columnar nozzle Is provided.

  Further, the pump sends air to the nozzle in conjunction with the rotation of the stirring and conveying member.

  Further, the layer thickness regulating member is interposed between the nozzle and the developing roller.

  The nozzle has an air outlet that faces both ends of the agitating and conveying member.

  Further, the nozzle is made of a porous member having pores of 2 microns or less, and air is blown from the porous member.

  In such a developing device of the present invention, by supplying air to the toner conveyed by the supply roller, it is possible to effectively loosen the one-component developer (toner) and improve its fluidity. For this reason, it is possible to prevent toner from staying on the surface of the supply roller, and as a result, a thin toner layer having a uniform layer thickness can be formed on the surface of the developing roller, thereby preventing image unevenness.

  In addition, the air supply means includes a cylindrical nozzle parallel to the supply roller and a pump that sends air to the nozzle, and air is blown from the plurality of nozzles of the nozzle toward the supply roller. The amount of toner can be effectively prevented from staying on the surface of the supply roller.

  Further, since the pump sends air to the nozzle in conjunction with the rotation of the supply roller, the air supply is stopped when the supply roller is not rotating, so that the air supply is not unnecessarily performed.

  In addition, the structure in which the layer thickness regulating member is interposed between the nozzle and the developing roller prevents air from entering between the developing roller and the layer thickness regulating member, so that air blowing out forms a thin toner layer on the developing roller surface. Will not be disturbed.

  Further, the arrangement in which the air blowing ports are arranged toward both ends of the supply roller facilitates toner replacement at both ends of the developing tank where toner is not consumed.

  Further, the configuration in which the nozzle is provided with an air blowing port made of a porous member having pores of 2 microns or less makes it difficult for the toner to enter the nozzle and prevents the nozzle from clogging for a long period of time.

  On the other hand, in another developing device of the present invention, since air is supplied to the toner stirred by the toner stirring and conveying member, the toner can be stirred efficiently with less stirring energy, and the toner friction during stirring Is reduced.

  Further, since the agitating / conveying member is disposed in the vicinity of the supply roller and the layer thickness regulating member, the agitated toner is immediately supplied to the developing roller.

  The air supply means includes a cylindrical nozzle parallel to the supply roller, and a pump that sends air to the nozzle, and air is blown out from the plurality of air blowout ports of the nozzle toward the agitating and conveying member. The fluidity of the toner agitated by the toner agitating and conveying member can be effectively improved by the supply amount.

  In addition, since the pump sends air to the nozzle in conjunction with the rotation of the toner agitating and conveying member, the air supply is stopped when the toner agitating and conveying member is not rotating. Absent.

  In addition, the structure in which the layer thickness regulating member is interposed between the nozzle and the developing roller prevents air from entering between the developing roller and the layer thickness regulating member, so that air blowing out forms a thin toner layer on the developing roller surface. Will not be disturbed.

  Further, the arrangement in which the air blowing ports are arranged toward the both end portions of the toner agitating / conveying member facilitates toner replacement at both end portions of the developing tank where toner is not consumed.

  Further, the configuration in which the nozzle is provided with an air blowing port made of a porous member having pores of 2 microns or less makes it difficult for the toner to enter the nozzle and prevents the nozzle from clogging for a long period of time.

  Hereinafter, embodiments of the developing device of the present invention will be described in detail.

-Outline description of development device-
FIG. 1 is a sectional view showing Embodiment 1 of the developing device of the present invention. The developing device 10 develops an electrostatic latent image on the surface of the photosensitive drum 30 using a one-component developer (hereinafter referred to as toner), and is detachably attached to the developing tank 20 and the upper side of the developing tank 20. And a toner cartridge 19 attached to the printer. The toner cartridge 19 stores toner, and the toner is naturally dropped into the developing tank 20 from the toner replenishing port 19a and replenished.

  Inside the developing tank 20, a developing roller 21 is disposed horizontally (disposed perpendicularly to the paper surface) so as to face the photosensitive drum 30 in the opening 20 a of the developing tank 20. The toner supply roller 22 is horizontally disposed so as to come into contact. A toner layer thickness regulating member 23 for regulating the layer thickness of the toner attached to the roller is disposed along the developing roller 21. A toner agitation transport member 28 for agitating and transporting the toner is horizontally disposed in the vicinity of the upper portion of the toner supply roller 22 and the toner layer thickness regulating member 23 thus disposed. The toner agitating / conveying member 28 supports a stainless steel shaft 28b, which is a weight member, at a position deviated from the center of the rotary shaft 28a. The coil spring 27 can be rotated on the stainless steel shaft 28b and the rotational angle thereof is set to a predetermined angle. It is configured to be inserted in a regulated state. When the rotating shaft 28a of the toner stirring / conveying member 28 is rotationally driven, the stainless shaft 28b and the coil spring 27 circulate around the rotating shaft 28a, and the toner is stirred and conveyed by the stainless shaft 28b and the coil spring 27.

  The toner layer thickness regulating member 23 is fixed to the frame portion of the developing tank 20 on the base end side with screws 29, and the front end side of the toner layer thickness regulating member 23 extends toward the downstream side in the rotation direction R of the developing roller 21. It is arranged in a cantilever shape. The leading end portion of the toner layer thickness regulating member 23 has a bent tip portion 23 a bent in a substantially “<” shape in a direction away from the surface of the developing roller 21, and the bent tip portion 23 a is formed on the surface of the developing roller 21. It is in pressure contact with the contact part F1.

  A toner supply roller 22 is pressed against the developing roller 21. The rotation direction of the toner supply roller 22 is the same direction R as that of the developing roller 21, and the moving directions of the surfaces of both rollers in the portion facing the developing roller 21 rotate in opposite directions.

  A voltage is applied to the toner supply roller 22 from a bias power source (not shown), and the voltage is larger in the direction in which the toner is electrically pushed toward the developing roller 21, for example, in the case of negative polarity toner, on the negative side. Bias voltage. The toner supply roller 22 frictionally charges the toner to a negative polarity and supplies the frictionally charged toner to the developing roller 21 by a bias voltage on the negative side of the toner supply roller 22. The developing roller 21 is applied with a bias voltage and carries the toner supplied from the toner supply roller 22 on its surface. Thereby, a thin layer of toner is formed on the surface of the developing roller 21. The toner thin layer on the surface of the developing roller 21 is conveyed to a position where the toner layer thickness regulating member 23 abuts by the rotation operation of the developing roller 21, and is regulated to a predetermined charge amount and thickness by the toner layer thickness regulating member 23. After that, the image is conveyed to a developing area (a portion facing the photosensitive drum 30 on which the electrostatic latent image is formed) and attached to the electrostatic latent image on the photosensitive drum 30 to develop the electrostatic latent image. Visualize.

  Residual toner on the surface of the developing roller 21 that has not been used in the development of the electrostatic latent image returns to the developing layer 20 as the developing roller 21 rotates. Then, the charged charge of the residual toner on the surface of the developing roller 21 is removed by the charge neutralizing device 26 installed in front of the toner supply roller 22, and the residual toner on the surface of the developing roller 21 is pressed by the toner supply roller 22 and the developing roller 21. Is removed and reused.

  The photoconductive drum 30 is a drum-shaped conductive base material provided with a surface layer of a photoconductive material on the outer periphery thereof. The conductive base material is grounded, and its surface potential is charged to, for example, -600 V. It is rotated at a peripheral speed Va (for example, 117 mm / s) in the direction of the arrow.

  The developing roller 21 is a conductive elastic roller made of conductive urethane rubber to which a conductive agent such as carbon black is added on the surface of a cylindrical member, and has a peripheral speed Vb (for example, 225 mm) in the direction of the arrow in FIG. / S). A voltage of E1 (for example, −400 V) is applied to the developing roller 21 by a developing bias power source through a shaft of a conductive support (stainless steel, conductive resin, etc.) (not shown).

  The toner supply roller 22 is made of conductive urethane foam that serves as both toner agitation and toner removal after development, and rotates at a peripheral speed Vc (for example, 133 mm / s) in the direction of the arrow. A voltage of E2 (for example, −450 V) is applied to the toner supply roller 22 by a supply bias power source through a shaft of a conductive support (not shown) such as stainless steel or conductive resin.

  The non-magnetic toner negatively charged by the supply roller 22 and transferred to the surface of the developing roller 21 is transported to a position where the toner layer thickness regulating member 23 contacts with the rotation of the developing roller 21.

  The toner layer thickness regulating member 23 is a conductive (such as stainless steel, phosphor bronze, conductive resin, etc.) plate member having a thickness of 0.1 mm, and has a cantilever plate spring structure as described above. 21 is contacted at a linear pressure of about 15 to 30 gf / cm. A voltage of E3 (for example, −450 V) is applied to the toner layer thickness regulating member 23 by a bias power source (not shown).

  The toner thin layer on the surface of the developing roller 21 is developed so that the toner adhesion amount and the toner charging amount are regulated to a predetermined amount by the toner layer thickness regulating member 23 and then the developing roller 21 rotates and contacts the photosensitive drum 30. Then, the electrostatic latent image on the surface of the photosensitive drum 30 is contact-reversed and developed.

  By the way, in the developing device 10 using such a toner, if the fluidity of the toner is lost, it becomes difficult to form a thin layer of toner on the surface of the developing roller 21, so it is necessary to ensure the fluidity of the toner. For this reason, the toner is agitated by the toner agitating / conveying member 28 and the toner supply roller 22, but it is difficult to ensure the fluidity of the toner even if only the agitation is used.

  Therefore, in the developing device 10 of the present embodiment, an air blowing nozzle 31 is provided above the toner supply roller 22 as shown in FIGS. 1 and 2, and air is blown from the air blowing nozzle 31 to loosen the toner. Improves fluidity.

  Next, a configuration for blowing out such air will be described in detail. As shown in FIG. 1, the toner cartridge 19 is provided with an air suction port 32a, and the air suction port 32a is connected to the air blowing nozzle 31 through a blower pipe 32b. Two check valves 32c are inserted in the middle of the blow pipe 32b, and an air pump 33a is connected to the blow pipe 32b between the check valves 32c. Further, the air blowing nozzle 31 is installed in parallel with the toner supply roller 22 and the toner agitating / conveying member 28 in the vicinity of the bent front end portion 23 a of the toner layer thickness regulating member 23 in the developing tank 20. The bent tip portion 23 a of the toner layer thickness regulating member 23 is interposed between the developing roller 21 and the air blowing nozzle 31.

  Here, as shown in FIG. 3, the air blowing nozzle 31 has a plurality of air blowing holes 31a arranged on the surface of a pipe made of stainless steel or resin. As shown in FIG. 2, each air blowing hole 31a of the air blowing nozzle 31 blows air downward.

  The air pump 33a is expanded and contracted by a cam 33b that rotates in conjunction with the rotation of the developing roller 21, the toner supply roller 22, or the toner stirring and conveying member 28, and pumps air to the blower pipe 32b. The air is pumped to the air blowing nozzle 31 through the blower pipe 32 b and blown from the air blowing holes 31 a of the air blowing nozzle 31, and the toner supply roller 22, the developing roller 21, and the toner layer thickness regulating member 23 are bent. The toner is sprayed on the toner near the tip 23a. Accordingly, the toner is efficiently loosened and the fluidity is improved, so that the toner is circulated well, and the toner staying in the vicinity of the bent tip portion 23a of the toner layer thickness regulating member 23 can be prevented. As a result, a thin toner layer having a uniform layer thickness can be formed on the surface of the developing roller 21, and image unevenness can be prevented.

  More specifically, as shown in FIG. 2, the toner is conveyed in the direction B along with the rotation of the supply roller 22, but the air blowing nozzle 31 is stationary in the vicinity of the bent tip portion 23 a of the toner layer thickness regulating member 23. Since air is blown in the direction A, the toner does not stay and is loosened before the toner is aggregated, thereby improving the fluidity of the toner. For this reason, the toner replenished from the toner cartridge 19 and the toner conveyed by the rotation of the supply roller 22 can be efficiently exchanged, and toner deterioration and stress are reduced. As a result, embedding and releasing of the toner external additive due to stress can be prevented, and a toner thin layer having a uniform layer thickness is formed on the surface of the developing roller 21, and filming on the roughness and toner layer thickness regulating member 23 is achieved. The occurrence of image deterioration such as (fusion) and filming on the photosensitive drum 30 can be suppressed.

  Further, since air is directly blown from the air blowing holes 31a of the air blowing nozzle 31 to the toner in the vicinity of the toner supply roller 22, it is possible to effectively prevent toner from staying on the surface of the toner supply roller 22 with a small air supply amount. It is possible to use a small air pump 33a.

  Further, since the toner layer thickness regulating member 23 is interposed between the developing roller 21 and the air blowing nozzle 31, air does not enter between the developing roller 21 and the toner layer thickness regulating member 23, and air blowing out the developing roller. 21 does not hinder the formation of a toner thin layer on the surface.

  Further, the cam 33b interlocked with the rotation of the toner agitating / conveying member 28 extends the air pump 33a at the timing when the stainless steel shaft 28b and the coil spring 27 of the toner agitating / conveying member 28 are separated from the supply roller 22, and enters the air pump 33a. Air is sucked in, and the air pump 33a is reduced at the timing when the stainless steel shaft 28b and the coil spring 27 approach the supply roller 22, and the air in the air pump 33a is discharged and pressure-fed. As a result, air is blown in a timely manner on the toner stirred by the toner stirring and transporting member 28 and transported to the toner supply roller 22 and the developing roller 21, the stirring of the toner is promoted, and the toner is efficiently loosened. By increasing the fluidity, the toner is circulated well, and toner retention in the vicinity of the bent tip portion 23a of the toner layer thickness regulating member 23 can be prevented.

  Further, since the cam 33b is interlocked with the developing roller 21, the toner supply roller 22, and the toner agitating / conveying member 28, when these are not rotating, the air supply is stopped and the air supply is not performed unnecessarily. .

  Instead of the air pump 33a, an air pump 33d as shown in FIG. 4 may be provided. The air pump 33 d is operated by applying a signal for controlling driving of a motor that is a driving source of the toner agitating / conveying member 28 to the driving source of the pump 33 d, and pumps air into the developing tank 20.

  Further, instead of the air blowing nozzle 31, an air blowing nozzle 31A shown in FIG. The air blowing nozzle 31A is provided with air blowing holes 31a at portions facing both ends of the toner supply roller 22, and is not easily consumed. The toner can be loosened and replaced efficiently. As a result, embedding and releasing of the toner external additive due to the stress can be prevented, and a toner thin layer having a uniform layer thickness can be formed, and filming (fusion) on the toner layer thickness regulating member 23 can be performed. Further, the occurrence of image deterioration causes such as filming on the photosensitive drum 30 can be suppressed.

  Furthermore, instead of the air blowing nozzle 31, an air blowing nozzle 31B shown in FIG. This air blowing nozzle 31B is obtained by replacing a part of the pipe surface with a porous member 31b having a pore of 2 microns or less such as a sponge such as urethane having continuous pores, ceramic or the like. The air can be blown out uniformly in the axial direction of the toner, and the toner can be more efficiently loosened before being agglomerated without retaining the toner.

  FIG. 7 is a sectional view showing Embodiment 2 of the developing device of the present invention. In FIG. 7, the same reference numerals are given to portions that perform the same operations as those in FIGS. 1 and 2.

  In the developing device of the present embodiment, the direction of each air blowing hole 31a of the air blowing nozzle 31 is different from that of the device of FIGS.

  Each air blowing hole 31a of the air blowing nozzle 31 is directed to the stainless steel shaft 28b of the toner agitating / conveying member 28 and the lower part of the circular orbit of the coil spring 27, and the toner agitated by the toner agitating / conveying member 28 is supplied with air. To promote toner agitation.

  More specifically, as shown in FIG. 7, the toner is conveyed in the direction C along the rotation of the toner agitating / conveying member 28, but in the vicinity of the bent tip portion 23 a of the toner layer thickness regulating member 23, the air blowing nozzle 31. Since air is constantly blown in the direction D, the toner can be loosened before agglomeration, and the fluidity of the toner is improved. For this reason, the toner replenished from the toner cartridge 19 and conveyed in the direction C along the rotation of the toner agitating / conveying member 28 and the toner conveyed in the direction B by the rotation of the supply roller 22 are efficiently exchanged. Reduces toner degradation and stress. As a result, embedding and releasing of the toner external additive due to the stress can be prevented, and a thin toner layer having a uniform layer thickness is formed on the surface of the developing roller 21. ) And image degradation causes such as filming on the photosensitive drum 30 can be suppressed.

  Further, since air is directly blown out from the air blowing holes 31a of the air blowing nozzle 31 to the toner in the vicinity of the toner stirring and conveying member 28, the stirring of the toner is effectively promoted with a small air supply amount, and the fluidity of the toner is improved. Can be improved.

  Further, since the toner layer thickness regulating member 23 is interposed between the developing roller 21 and the air blowing nozzle 31, air does not enter between the developing roller 21 and the toner layer thickness regulating member 23, and air blowing out the developing roller. 21 does not hinder the formation of a toner thin layer on the surface.

  The air blowing nozzle 31 may be replaced with the air blowing nozzle 31A in FIG. 5 or the air blowing nozzle 31B in FIG. When the air blowing nozzle 31A shown in FIG. 5 is used, it is difficult to consume the toner, and the toner that is easily subjected to stress at both ends of the developing tank 20 can be loosened and replaced efficiently.

  Further, when the air blowing nozzle 31B in FIG. 6 is replaced, air can be blown uniformly in the axial direction of the supply roller 22, and the toner can be loosened more efficiently before the toner is aggregated without causing the toner to stay. it can.

  The developing device of the above embodiment has a separate structure from the photosensitive drum. However, if the present invention is applied to a process cartridge in which the photosensitive drum is integrated, the developing device stays in the developing device due to aggregation. Thus, it is possible to provide a process cartridge that can be completely used without leaving toner that does not contribute to development, and that can be easily handled while suppressing variations in the life of the photoreceptor.

  Furthermore, by using such a process cartridge, it is possible to form a thin toner layer with a uniform layer thickness, which causes image deterioration such as roughness, filming on a toner regulating member (filming), filming on a photoreceptor, etc. Therefore, it is possible to easily provide an image forming apparatus that is excellent in image quality.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. It is understood.

It is sectional drawing which shows Embodiment 1 of the developing device of this invention. FIG. 2 is an enlarged cross-sectional view showing the periphery of a developing roller and a toner supply roller in the apparatus of FIG. It is a top view which shows the air blowing nozzle in the apparatus of FIG. It is sectional drawing which shows the modification of the apparatus of FIG. It is a top view which shows the modification of an air blowing nozzle. It is a top view which shows the other modification of an air blowing nozzle. It is sectional drawing which shows Embodiment 2 of the image development apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Developing device 19 Toner cartridge 19a Toner replenishing port 20 Developing tank 21 Developing roller 20a Opening portion 22 Toner supply roller 23 Toner layer thickness regulating member 23a Bent tip portion 27 Coil spring 28 Toner stirring and conveying member 28b Stainless steel shaft 30 Photosensitive drum 31 Air Blowout nozzle 31a Air blowout hole 31b Porous member 32a Air suction port 32b Air blow pipe 32c Check valve 33a Air pump 33b Cam

Claims (13)

A developing roller that carries a layer of one-component developer on the peripheral surface, a supply roller that supplies the one-component developer to the peripheral surface of the developing roller, and a layer thickness that regulates the layer thickness of the one-component developer on the peripheral surface of the developing roller A regulating member, a developing roller, a supply roller, a layer thickness regulating member, and a developing tank for storing a one-component developer, and an electrostatic latent image on the surface of the photosensitive drum is formed by the one-component developer on the circumferential surface of the developing roller. In the developing device to be visualized,
A developing device comprising air supply means for supplying air to the toner supplied and conveyed by the supply roller.   The air supply means includes a columnar nozzle arranged in parallel with the supply roller and a pump for sending air to the nozzle, and the columnar nozzle is provided with a plurality of air outlets facing the supply roller. The developing device according to claim 1.   The developing device according to claim 2, wherein the pump sends air to the nozzle in conjunction with rotation of the supply roller.   The developing device according to claim 2, wherein the layer thickness regulating member is interposed between the nozzle and the developing roller.   The developing device according to claim 2, wherein the nozzle has an air outlet that faces both ends of the supply roller.   The developing device according to claim 2, wherein the nozzle is made of a porous member having pores of 2 microns or less, and blows air from the porous member. A developing roller that carries a layer of one-component developer on the peripheral surface, a supply roller that supplies the one-component developer to the peripheral surface of the developing roller, and a layer thickness that regulates the layer thickness of the one-component developer on the peripheral surface of the developing roller A developing roller peripheral surface having a regulating member, a stirring and conveying member that stirs the one-component developer, a developing roller, a supply roller, a layer thickness regulating member, a stirring and conveying member, and a developing tank that stores the one-component developer. In the developing device for visualizing the electrostatic latent image on the surface of the photosensitive drum with one component developer,
A developing device comprising air supply means for supplying air to the toner stirred by the stirring and conveying member.   The developing device according to claim 7, wherein the stirring and conveying member is disposed in the vicinity of the supply roller and the layer thickness regulating member.   The air supply means includes a columnar nozzle arranged in parallel with the supply roller and a pump for sending air to the nozzle, and the columnar nozzle is provided with a plurality of air outlets facing the agitating and conveying member. The developing device according to claim 7, wherein:   The developing device according to claim 9, wherein the pump sends air to the nozzle in conjunction with rotation of the stirring and conveying member.   The developing device according to claim 9, wherein the layer thickness regulating member is interposed between the nozzle and the developing roller.   The developing device according to claim 9, wherein the nozzle has an air blowing port facing both ends of the stirring and conveying member.   The developing device according to claim 9, wherein the nozzle is made of a porous member having pores of 2 microns or less, and blows air from the porous member.

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