JP2011048129A - Developer electric field-conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer electric field conveying device which makes a conveying state of developer more appropriate. <P>SOLUTION: The developer electric field-conveying device includes a developer alternating current generating means. The developer alternating current-generating means generates alternating current of the developer between a surface layer part in the developer being conveyed on the developer conveying surface and a lower layer part adjacent to the developer conveying surface, by generating flow of the developer in a normal line direction of the developer conveying surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a developer electric field conveying apparatus configured to convey a charged powdery developer by an electric field.

  Such devices are disclosed in Japanese Patent Application Laid-Open Nos. 2001-209246, 2002-287495, 2003-295615, 2008-70587, 2009-3307, and the like. What is known. Such an apparatus includes a plurality of transport electrodes arranged along a developer transport path, and is configured to transport the developer by an electric field generated by applying a voltage to the plurality of transport electrodes.

  By the way, the developer being conveyed is separated into two layers of a lower layer part (a layer adjacent to the carrier electrode) and a surface layer part (a layer farther from the carrier electrode than the lower layer part) by the traveling wave electric field. It has been found by computer simulation by the present inventor that the developer exhibits a good behavior and the charge amount of the developer tends to be low in the surface layer portion and high in the lower layer portion.

  However, while the lower layer portion has a low charge amount, the surface layer portion also has a high charge amount. Therefore, for example, when the surface layer portion and the lower layer portion of the two layers described above are separated and the developer in the lower layer portion is subjected to development, it is suitable for development in normal (conventional) electric field transport. In addition, there is room for improvement in the efficiency of conveying the developer having an appropriate charge amount to the development position.

  As described above, in this type of conventional apparatus, there is still room for improvement with respect to the developer transport state. The present invention has been made to cope with such a problem. That is, an object of the present invention is to make the developer transport state more appropriate.

<Configuration>
The developer electric field transport device which is the subject of the present invention is configured to transport a charged powdery developer by an electric field (in the air). For example, the developer electric field transport device of the present invention can be configured to supply the developer to a predetermined developer supply target (an electrostatic latent image carrier, that is, a photoreceptor, etc.).

  Specifically, the developer electric field transport device of the present invention transports the developer along the developer transport path by an electric field generated in response to application of a multiphase AC voltage to a plurality of transport electrodes. It is configured. Here, the transport electrode has a longitudinal direction along the main scanning direction. The plurality of transport electrodes are arranged along the developer transport path that intersects the main scanning direction.

  The plurality of transport electrodes are supported by a developer transport body. That is, the developer transport body is configured to support the plurality of transport electrodes along a developer transport surface that is a surface of the developer transport body facing the developer transport path.

  The developer electric field transport device of the present invention is provided with developer AC generating means. The developer alternating current generating means generates a flow of the developer along a normal direction of the developer transport surface, so that a surface layer portion in the developer being transported on the developer transport surface, An alternating current of the developer is generated between the developer transport surface and a lower layer portion adjacent to the developer transport surface. That is, the present invention is characterized in that the developer electric field transport device includes developer AC generating means having the above-described configuration.

  The developer alternating current generating means may be configured to spray the developer and / or air toward the developer transport surface. Specifically, for example, the developer alternating current generating means is an air flow generating means configured to generate an air current that collides with the developer transport surface.

<Action>
In such a configuration, a traveling-wave electric field is generated with the application of the multiphase AC voltage to the plurality of carrier electrodes. By the action of the electric field, the developer is transported in the developer transport direction on the developer transport surface. At this time, as described above, the developer exhibits a behavior such that it is divided into two layers of the lower layer portion and the surface layer portion.

  Therefore, the developer flow is generated along the normal direction of the developer transport surface by the developer alternating current generating means. Then, an alternating current of the developer is generated between the surface layer portion and the lower layer portion. Thereby, for example, redistribution of the developer may occur between the surface layer portion and the lower layer portion. Specifically, the developer having an appropriate charge amount suitable for development existing in the surface layer part can move to the lower layer part side. Alternatively, for example, a low charge amount can be charged by collision or friction to increase the charge amount.

  As described above, according to the developer electric field transport device of the present invention, the transport state of the developer can be made more appropriate. Specifically, for example, the efficiency of transporting the developer having an appropriate charge amount suitable for development to the development position is improved.

1 is a side view showing a schematic configuration of a laser printer as an image forming apparatus to which an embodiment of the present invention is applied. FIG. 2 is an enlarged side sectional view of the toner supply device shown in FIG. 1. FIG. 3 is an enlarged side cross-sectional view of the transport substrate shown in FIG. 2. It is a graph which shows an example of the output waveform of each power supply circuit shown by FIG. FIG. 4 is a diagram showing a result of computer simulation of the behavior of toner being conveyed by a traveling wave electric field on the conveyance substrate shown in FIG. FIG. 4 is a side sectional view showing a schematic configuration of a modified example of the toner supply device shown in FIG. 2. FIG. 10 is a side sectional view showing a schematic configuration of another modification of the toner supply device shown in FIG. 2.

<Configuration of laser printer>
FIG. 1 is a side view showing a schematic configuration of a laser printer 1 to which an embodiment of the present invention is applied. Referring to FIG. 1, the laser printer 1 includes a paper transport mechanism 2, a photosensitive drum 3, a charger 4, a scanner unit 5, and a toner supply device 6.

  Paper P is stacked and stored in a paper feed tray (not shown) provided in the laser printer 1. The paper transport mechanism 2 is configured to transport the paper P along the paper transport path PP. The photosensitive drum 3 is configured to be rotationally driven around a central axis C parallel to the main scanning direction (z-axis direction in the drawing). An electrostatic latent image carrying surface LS is formed on the peripheral surface of the photosensitive drum 3. The electrostatic latent image carrying surface LS is a cylindrical surface parallel to the main scanning direction, and an electrostatic latent image is formed by a potential distribution, and at the position corresponding to the electrostatic latent image, toner T (FIG. 2). Reference).

  The scanner unit 5 emits a laser beam LB having a predetermined wavelength band modulated based on image data (light emission ON / OFF is controlled depending on the presence or absence of pixels) at the scanning position SP. An image is formed (exposed) on the surface, and the image formation position is moved (scanned) along the main scanning direction at a constant speed, whereby an electrostatic latent image is formed on the electrostatic latent image carrying surface LS. It is configured to form.

  The toner supply device 6 is disposed below the photosensitive drum 3 so as to face the photosensitive drum 3. The toner supply device 6 is configured to supply toner to the electrostatic latent image carrying surface LS in a charged state at the development position DP. Here, the development position DP is a position where the toner supply device 6 faces the electrostatic latent image carrying surface LS.

  Next, the specific configuration of each part of the laser printer 1 will be described in more detail.

  The sheet transport mechanism 2 includes a pair of registration rollers 21 and a transfer roller 22. The registration roller 21 is configured to send the paper P toward the transfer position TP between the photosensitive drum 3 and the transfer roller 22 at a predetermined timing. The transfer roller 22 is disposed so as to face the electrostatic latent image carrying surface LS, which is the outer peripheral surface of the photosensitive drum 3, with the sheet P interposed therebetween at the transfer position TP. The transfer roller 22 is connected to a bias power supply circuit (not shown).

<< Toner Supply Device >>
FIG. 2 is a partially exploded side sectional view in which the toner supply device 6 shown in FIG. 1 is enlarged. Referring to FIG. 2, the toner supply device 6 is configured to supply charged toner T to the photosensitive drum 3 (electrostatic latent image carrying surface LS).

  A main body casing 60 which is a casing of the toner supply device 6 is a box-shaped member formed in an approximately oval shape in a side sectional view, and its longitudinal direction is parallel to the vertical direction (y-axis direction in the figure). Are arranged as follows. In the main body casing 60, toner T (positive chargeability, non-magnetic one component, black) as a powdery dry developer is accommodated. The main body casing 60 includes a main body side rear panel 60a, a main body side front panel 60b, a main body side bottom plate 60c, a main body side top plate 60d, and a pair of side walls 60e.

  The main body side rear panel 60a and the main body side front panel 60b, which are flat members, are provided so as to face each other so that their upper end edges are parallel to the main scanning direction and have the same height. A toner replenishing opening 60f is formed at the lower end of the main body side rear panel 60a over almost the entire width of the main body side rear panel 60a in the main scanning direction.

  The upper end of the arcuate portion (downstream portion in the toner transport direction TTD) of the main body side bottom plate 60c in side sectional view is connected to the main body side front panel 60b. Further, a rear end (right end in the drawing) of a flat plate-like portion (upstream portion in the toner transport direction TTD) of the main body side bottom plate 60c is provided at a position corresponding to the toner replenishing opening 60f. .

  The main body side top plate 60d is a thin semi-cylindrical member having a central axis parallel to the main scanning direction, and is connected to upper end edges of the main body side rear panel 60a and the main body side front panel 60b. A pair of main body side rear panel 60a, main body side front panel 60b, main body side bottom plate 60c, and main body side top plate 60d are formed so as to close the sides of the substantially oval synthetic resin frame in a side sectional view. A side wall 60e is provided. A developing opening 60 h is provided at the top of the main body side top plate 60 d so as to face the photosensitive drum 3 so as to open upward toward the photosensitive drum 3.

  A toner containing cartridge 61 is provided on the main body side rear panel 60a side so as to be adjacent to the main body casing 60 (see the two-dot chain line in the figure: a solid line indicates a state in which the toner containing cartridge 61 is detached from the main body casing 60). ing). The toner storage cartridge 61 is a box-shaped member, and the toner T is stored (stored) therein.

  A flat toner cartridge-side front panel 61 a is provided on the toner accommodating cartridge 61 on the side facing (contacting) the main body casing 60. The toner cartridge side bottom plate 61b, which is the bottom plate of the toner containing cartridge 61, is formed in a flat plate shape. A toner delivery opening 61c is formed at the lower end of the toner cartridge side front panel 61a. The toner delivery opening 61c is formed so as to communicate with (substantially match) the toner replenishment opening 60f when the toner cartridge side front panel 61a is joined to the main body rear panel 60a in the main body casing 60. Yes.

  A developing roller 62 is accommodated inside the main casing 60. The developing roller 62 is a roller-shaped member having a toner carrying surface 62 a that is a cylindrical peripheral surface and is driven to rotate about an axis parallel to the main scanning direction. Supported as possible. The developing roller 62 is provided so as to face the photosensitive drum 3 at the developing opening 60h.

  Inside the main body casing 60, a transport substrate 63 is provided along the toner transport path TTP. The transfer board 63 is fixed to the inner wall surface of the main body casing 60. That is, the toner transport path TTP is formed in a substantially oval shape in a side sectional view along the toner transport surface TTS that is the surface of the transport substrate 63. The transport substrate 63 is configured to transport the positively charged powdery toner T in a toner transport direction TTD parallel to the toner transport path TTP (tangential direction in a side sectional view of the toner transport path TTP). . In the present embodiment, the transport substrate 63 includes a bottom transport substrate 63a, an upper transport substrate 63b, and a lower transport substrate 63c.

  The bottom transfer board 63a is supported on the inner wall surface of the main body side bottom plate 60c, and is smoothly connected to the lower end of the upper transfer board 63b. The upper transfer board 63b is supported on the inner wall surfaces of the main body side front panel 60b and the main body side top plate 60d. The lower transfer board 63c is supported on the inner wall surface of the main body side rear panel 60a. In the present embodiment, the end portion of the lower transport substrate 63c in the toner transport direction TTD is provided to a position corresponding to the toner replenishment opening 60f.

  The bottom transfer board 63a and the upper transfer board 63b are electrically connected to the transfer power supply circuit 64. The lower transfer board 63c is electrically connected to the recovery power supply circuit 65. The carrier power supply circuit 64 and the recovery power supply circuit 65 are configured to output a multiphase (four-phase in the present embodiment) AC voltage, as will be described later. The developing roller 62 is electrically connected to the developing bias power supply circuit 66.

  A shielding plate 67 is disposed in parallel to the horizontal plane at a position below the developing roller 62 and in the vicinity of the upper transport substrate 63b in the space inside the main casing 60. A predetermined gap (details will be described later) is provided between the restriction end 67a, which is the end of the shielding plate 67 on the side facing the upper transfer board 63b, and the upper transfer board 63b.

  The toner supply device 6 also includes a toner input state control unit 68. The toner charging state control means 68 is located at a position where the toner replenishing opening 60f and the toner sending opening 61c communicate with each other in order to adjust the loading and unloading of the toner T between the main body casing 60 and the toner containing cartridge 61. The main body casing 60 and the toner containing cartridge 61 are provided so as to straddle.

  The toner charging state control means 68 includes a support 68a, a first charging state control board 68b, and a second charging state control board 68c. The first charging state control board 68b and the second charging state control board 68c are supported by a support body 68a. The support 68a is formed in a cylindrical shape having a central axis parallel to the main scanning direction.

  The first input state control board 68b is provided so as to face the lower end portion of the lower transfer board 63c. The second input state control board is provided to face the bottom transfer board 63a. Specifically, the first charging state control board 68b is provided so as to cover the upper half of the support body 68a. The second charging state control board 68c is provided so as to cover the lower half of the support 68a. The first loading state control board 68b and the second loading state control board 68c have the same structure as the transfer board 63.

  The air duct 69 is provided so as to face a flat plate-shaped lowest portion (upstream portion in the toner transport direction TTD) of the bottom transport substrate 63a. The air duct 69 is formed with an air ejection opening 69a that opens toward the toner transport surface TTS. The air ejection opening 69a is provided along the main scanning direction. The air duct 69 blows air toward the toner transport surface TTS at the lowest flat portion of the bottom transport substrate 63a by ejecting air from the air ejection opening 69a (impacts the toner transport surface TTS). The air flow is generated and arranged).

<<< Transport substrate >>>
FIG. 3 is an enlarged side sectional view of the transfer board 63 shown in FIG. Referring to FIG. 3, the transport substrate 63 is a thin plate-like member having the same configuration as the flexible printed circuit board, and includes a transport electrode 631, a transport electrode support film 632, a transport electrode coating layer 633, and a transport electrode. An overcoating layer 634.

  The transport electrode 631 is a linear wiring pattern having a longitudinal direction parallel to the main scanning direction. The plurality of transport electrodes 631 are arranged along the toner transport path TTP and are arranged in parallel to each other. That is, the transport substrate 63 is configured to support a plurality of transport electrodes 631 along the toner transport surface TTS that is a surface facing the toner transport path TTP.

  Each of the plurality of transport electrodes 631 arranged along the toner transport path TTP is connected to the same power supply circuit every third. That is, the transfer electrode 631, connected to the power supply circuit VA, the transfer electrode 631, connected to the power supply circuit VB, the transfer electrode 631, connected to the power supply circuit VC, the transfer electrode 631, connected to the power supply circuit VD, and the power supply circuit VA. The transport electrodes 631, the transport electrodes 631, the transport electrodes 631,... Connected to the power circuit VC connected to the power supply circuit VB are sequentially arranged along the toner transport path TTP (note that these are connected. The power supply circuits VA to VD are components of the transport power supply circuit 64 and the recovery power supply circuit 65 in FIG.

  Here, FIG. 4 is a graph showing an example of output waveforms of the power supply circuits VA to VD shown in FIG. In the present embodiment, as shown in FIG. 4, each of the power supply circuits VA to VD is configured to output a drive voltage that is an AC voltage having substantially the same waveform. Further, the power supply circuits VA to VD are configured so that the phases of the waveforms of the voltages generated by the power supply circuits VA to VD are different by 90 °. That is, the voltage phase is delayed by 90 ° in order from the power supply circuit VA to the power supply circuit VD.

  As described above, the toner supply device 6 (see FIG. 2) is arranged on the toner transport surface TTS by an electric field generated when a multi-phase (four-phase in this embodiment) AC voltage is applied to the plurality of transport electrodes 631. The toner T is configured to be transported in the toner transport direction TTD along the toner transport path TTP.

  The plurality of transport electrodes 631 are formed on the surface of the transport electrode support film 632. The transport electrode support film 632 is a flexible film and is made of an insulating synthetic resin such as a polyimide resin. The transport electrode coating layer 633 is made of an insulating synthetic resin. The transport electrode coating layer 633 is provided to cover the transport electrode 631 and the surface of the transport electrode support film 632 where the transport electrode 631 is provided. A transport electrode overcoating layer 634 is provided on the transport electrode coating layer 633. That is, the above-described transport electrode coating layer 633 is formed between the transport electrode overcoating layer 634 and the transport electrode 631.

<Description of laser printer operation>
Hereinafter, an outline of the operation of the laser printer 1 configured as described above will be described together with actions and effects of the configuration of the embodiment with reference to the drawings as appropriate.

  First, referring to FIG. 1, the leading edge of the paper P stacked on the paper feed tray (not shown) is sent to the registration roller 21. The registration roller 21 corrects the skew of the paper P and adjusts the conveyance timing. Thereafter, the paper P is fed to the transfer position TP. As described above, while the paper P is being conveyed toward the transfer position TP, an image of the toner T is carried on the electrostatic latent image carrying surface LS that is the circumferential surface of the photosensitive drum 3 as follows. Is done.

  First, the electrostatic latent image carrying surface LS of the photosensitive drum 3 is uniformly charged to the positive polarity by the charger 4. The electrostatic latent image carrying surface LS charged by the charger 4 is moved in the direction orthogonal to the main scanning direction to the scan position SP by the rotation of the photosensitive drum 3.

  The laser beam LB modulated based on the image information is irradiated onto the electrostatic latent image carrying surface LS while being scanned along the main scanning direction at the scan position SP. Depending on the modulation state of the laser beam LB, a portion where the positive charges on the electrostatic latent image carrying surface LS disappear is generated. As a result, an electrostatic latent image having a positive charge pattern (image-like distribution) is formed on the electrostatic latent image carrying surface LS. The electrostatic latent image formed on the electrostatic latent image carrying surface LS moves toward the developing position DP facing the toner supply device 6 by the rotation of the photosensitive drum 3.

FIG. 5 is a diagram showing a result of a computer simulation of the behavior of the toner T being conveyed by a traveling wave electric field on the conveyance substrate 63 (bottom conveyance substrate 63a) shown in FIG. This computer simulation was performed using the individual element method under the following conditions (refer to FIG. 2 for the x, y, and z directions). In order to simplify the calculation, the thickness of the transport electrode 631 is assumed to be 0, and the transport electrode coating layer 633 and the transport electrode overcoating layer 634 are assumed to have a thickness of 25 μm and a relative dielectric constant of 2.5. It was.
Calculation space range: x direction 0.8mm, y direction 2.0mm, z direction 0.03mm
Calculation time: 0.04 seconds The width of the transport electrode 631 in the x direction: 0.1 mm
Gaps in the x direction between adjacent transport electrodes 631: 0.1 mm
Applied voltage: + 300V / -300V (rectangular wave)
About Toner T Number of particles: 2000 Particle size: 10 μm (spherical)
Charge per particle: average 2 fC (normal distribution with standard deviation 4 fC)
Density: 1.3 g / cm ³

  2 and 3, the positively charged toner T is transported in the toner transport direction TTD on the toner transport surface TTS of the bottom transport substrate 63a by a traveling wave electric field generated by a voltage applied to the transport electrode 631. The At this time, as shown in FIG. 5I, the toner T is divided into two layers, a lower layer portion close to the conveyance substrate 63 (bottom conveyance substrate 63a) and a surface layer portion above the lower layer portion. Shows behavior.

  As described above, the toner T that is being transported in the electric field while being divided into two layers of the lower layer portion and the upper surface layer portion thereof is an arc-shaped portion (downstream portion in the toner transport direction TTD) in a side sectional view of the bottom transport substrate 63a. To the upper transfer substrate 63b. The upper transport substrate 63b transports the toner T delivered from the bottom transport substrate 63a at the lower end thereof vertically upward.

  Here, among the toner T transferred from the bottom conveyance substrate 63a to the upper conveyance substrate 63b, the surface layer portion having a low positive charge amount (including relatively weakly charged, non-charged, and negatively charged ones) Due to the above and the shielding plate 67, the toner is separated from the toner transport path TTP and then falls downward. As a result, the lower layer portion of the toner T transferred from the bottom conveyance substrate 63a to the upper conveyance substrate 63b has a high positive charge amount (that is, contains a large amount of charge amount suitable for developing an electrostatic latent image). The sheet passes through the gap between the regulating end 67a of the shielding plate 67 and the toner transport surface TTS of the upper transport substrate 63b, and is transported toward the development position DP.

  The toner T that has passed through the gap is once carried on the developing roller 62 and then supplied to the developing position DP. The electrostatic latent image formed on the electrostatic latent image carrying surface LS is developed with the toner T in the vicinity of the development position DP. That is, the toner T adheres to a portion of the electrostatic latent image carrying surface LS where the positive charge in the electrostatic latent image has disappeared. As a result, an image of toner T (hereinafter referred to as “toner image”) is carried on the electrostatic latent image carrying surface LS.

  By the way, as shown in FIG. 5I, the charge amount of the toner T divided into two layers during electric field conveyance at the flat bottom portion (upstream portion in the toner conveyance direction TTD) of the bottom conveyance substrate 63a. Tends to be lower in the surface layer portion and higher in the lower layer portion (see FIG. 5 (II): the surface layer portion corresponds to the solid line and the lower layer portion corresponds to the broken line in the figure). However, as shown in FIG. 5 (II), the charge amount distribution is relatively wide across zero in both the surface layer portion and the lower layer portion. Therefore, some of the lower layer portions are not suitable for developing an electrostatic latent image (those having a low positive charge amount or those having a negative charge), while those on the surface layer portion are suitable for developing an electrostatic latent image (positive). High charge amount).

  Therefore, in the present embodiment, air is blown toward the toner transport surface TTS by the air duct 69 at the lowest flat portion of the bottom transport substrate 63a (see the white arrow in FIG. 2). Then, a flow of the toner T is generated in the normal direction of the toner transport surface TTS, and an alternating current of the toner T is generated between the surface layer portion and the lower layer portion. Thereby, for example, redistribution of the toner T may occur between the surface layer portion and the lower layer portion. Specifically, the toner T having an appropriate charge amount suitable for development, which was present in the surface layer portion, moves to the lower layer side, and is present in the lower layer portion and is not suitable for development. It can shift to the part side. Alternatively, for example, a low charge amount can be charged by collision or friction to increase the charge amount.

  The toner T on the toner carrying surface 62a that has passed through the development position DP (not consumed at the development position DP) moves to the lower transport substrate 63c side by the action of the recovery bias. That is, the toner T is collected from the toner carrying surface 62a by the lower transport substrate 63c. The toner T collected from the toner carrying surface 62a by the lower conveyance substrate 63c is conveyed downward by a traveling wave electric field.

  When the toner T is transported vertically downward to the lower end portion of the lower transport substrate 63c, the toner T reaches the toner input state control means 68. Here, the toner charging state control means 68 is provided between the main casing 60 and the toner containing cartridge 61 at a position where the toner replenishing opening 60f and the toner sending opening 61c communicate (see FIG. 2). Adjust the toner T in / out. Specifically, this adjustment is performed by applying a multiphase AC voltage similar to the drive voltage (see FIG. 4) applied to each transport electrode 631 (see FIG. 3) to the first input state control board 68b. And applied to the second charging state control board 68c. That is, according to the application state of the multiphase AC voltage to the first input state control board 68b and the second input state control board 68c (the same or opposite phase relationship as in FIG. 4), the main casing 60 and the toner containing cartridge 61 are changed. The toner T is taken in and out.

  Referring to FIG. 1, the toner image carried on the electrostatic latent image carrying surface LS of the photosensitive drum 3 as described above is transferred to the transfer position TP by the rotation of the electrostatic latent image carrying surface LS. It is conveyed toward. At the transfer position TP, the toner image is transferred onto the paper P from the electrostatic latent image carrying surface LS.

<List of examples of modification>
It should be noted that the above-described embodiments are merely examples of typical embodiments of the present invention that the applicant has considered to be the best at the time of filing of the present application. Therefore, the present invention is not limited to the above-described embodiment. Therefore, it goes without saying that various modifications can be made to the above-described embodiment within the scope not changing the essential part of the present invention.

  Hereinafter, some typical modifications will be exemplified. In the following description of the modified examples, the same reference numerals as those in the above embodiment can be used for members having the same configuration and function as those described in the above embodiment. And about description of this member, the description in the above-mentioned embodiment shall be used in the range which is not technically consistent.

  The application target of the present invention is not limited to a monochromatic laser printer. For example, the present invention can be suitably applied to a so-called electrophotographic image forming apparatus such as a color laser printer or a monochromatic and color copying machine. At this time, the shape of the photosensitive member may not be a drum shape as in the above-described embodiment. For example, a flat plate shape or an endless belt shape may be used. Further, as the exposure light source, other than the laser scanner (LED, EL (electroluminescence) element, phosphor, etc.) can be suitably used. Alternatively, the present invention is also suitably applied to an image forming apparatus of a system other than the above-described electrophotographic system (for example, a toner jet system that does not use a photoreceptor, an ion flow system, a multi-stylus electrode system, etc.). obtain.

  The photosensitive drum 3 and the developing roller 62 may be in contact with each other.

  The arrangement and configuration of the transport substrate 63 are not limited to those of the above-described embodiment. For example, as shown in FIG. 2, the upper conveyance board 63b may be arranged in parallel with the vertical direction so as to convey the toner T vertically upward, or intersect the vertical direction. The toner T may be transported in a direction intersecting with the vertically upper side by being arranged so as to be the same (the same applies to the lower transport substrate 63c). Also, the transport electrode overcoating layer 634 can be omitted. Alternatively, both the transport electrode coating layer 633 and the transport electrode overcoating layer 634 can be omitted by embedding the transport electrode 631 in the transport electrode support film 632. The same applies to the first input state control board 68b and the second input state control board 68c.

  The shielding plate 67 can be omitted. The toner charging state control means 68 may be a rotatable roller member.

  FIG. 6 is a side sectional view showing a schematic configuration of a modified example of the toner supply device 6 shown in FIG. In the toner supply device 6 of the modified example shown in FIG. 6, the gap between the toner replenishment opening 60f between the upper end of the shielding plate 67 and the upper end of the transport substrate 63b, which is opposed to the upper transport substrate 63b. Is formed in the shape of a slit at the same height. That is, to the position where the lower end of the plate-like portion on the downstream side in the toner conveyance direction TTD of the main body side rear panel 60a and the lower conveyance substrate 63c is close to and faces the lowest plate-like portion of the bottom conveyance substrate 63a. It has been extended. The lower transfer board 63c is provided so that the lower end of the lower transfer board 63c faces the flat plate-like part of the lowest part of the bottom transfer board 63a, so that the toner T is sprayed on the lower transfer board 63c.

  The main body casing 60 and the toner containing cartridge 61 are provided so as to be separated from each other in the front-rear direction (z-axis direction in the drawing). The main body side bottom plate 60c and the bottom conveyance board 63a are bridged between the toner replenishment opening 60f and the lower end of the toner delivery opening 61c, which are separated from each other in the front-rear direction (z-axis direction in the drawing). The flat part of the lowest part is extended. Further, a flat bottom transport substrate cover 60a1 is provided so as to extend in the front-rear direction from the lower end of the main body side rear panel 60a toward the toner containing cartridge 61 so as to cover the extended portion of the bottom transport substrate 63a from above. Yes.

  The toner input state control means 68 in this modification is a roller-like member, and is rotatably supported by the toner containing cartridge 61 at the toner delivery opening 61c. A roller cover 61a1 is provided at the lower end portion of the toner cartridge-side front panel 61a so as to cover the cylindrical peripheral surface of the roller-shaped toner input state control means 68.

  In the toner supply device 6 of the present modification having the above-described configuration, the roller-shaped toner charging state control means 68 is driven to rotate so that the positively charged toner T is transferred to the toner transport direction TTD of the bottom transport substrate 63a. Is supplied to the most upstream part (the right end in the figure). The toner T supplied to the uppermost stream portion in the toner transport direction TTD of the bottom transport substrate 63a is transported in the toner transport direction TTD (to the left in the drawing) by the lowest flat plate portion of the bottom transport substrate 63a. The

  At this time, the toner T is sprayed by the lower end portion of the lower conveyance substrate 63c at the lowest flat portion of the bottom conveyance substrate 63a (see the white arrow in FIG. 6). As a result, a flow of the toner T is generated in the normal direction of the toner transport surface TTS, and an alternating current of the toner T is generated between the surface layer portion and the lower layer portion.

  FIG. 7 is a side sectional view showing a schematic configuration of another modified example of the toner supply device 6 shown in FIG. The toner supply device 6 of the modified example shown in FIG. 7 is obtained by changing the configuration of the shielding plate 67 in FIG. That is, the shielding plate 67 shown in FIG. 7 includes a horizontal plate portion 671 and a standing plate portion 672, and is formed in an inverted L shape in a side sectional view.

  The horizontal flat plate portion 671 is a flat plate member corresponding to the shielding plate 67 shown in FIG. 6, and is arranged in parallel to the horizontal plane. A predetermined gap as described above is provided between the regulating end 671a facing the upper transport substrate 63b of the horizontal plate portion 671 and the upper transport substrate 63b.

  The upright plate portion 672 is a flat plate-like member connected to the end portion of the horizontal plate portion 671 facing the lower conveyance substrate 63c (the end portion on the side opposite to the regulating end portion 671a in the front-rear direction). It is provided so as to extend downward from the end. The upright plate portion 672 is provided so that the lower end portion 672a thereof faces the lowest flat plate portion of the bottom conveyance substrate 63a with a gap of the same level as the height of the toner replenishing opening 60f. Further, the lower end portion 672a of the upright plate portion 672 is provided so as to face the lower end portion of the lower transport substrate 63c with a gap of about the same height as the toner replenishing opening 60f.

  In the toner supply device 6 of the present modification having the above-described configuration, the regulating end portion of the horizontal plate portion 671 is disposed on the inner side (left side in the drawing) of the shielding plate 67 formed in an inverted L shape in a side sectional view. A substantially sealed space is formed having two openings: a gap between 671a and the upper transfer substrate 63b and a gap between the lower end portion 672a of the upright plate portion 672 and the bottom transfer substrate 63a. Is done.

  For this reason, the standing plate portion 672 is generated by the airflow (see the upward white arrow in FIG. 7) generated when the toner T passes through the gap between the regulating end portion 671a of the horizontal plate portion 671 and the upper conveyance substrate 63b. Air is sucked into the above-described space through the gap between the lower end portion 672a and the bottom conveyance substrate 63a. At this time, in the gap between the lower end portion 672a of the upright plate portion 672 and the lower end portion of the lower transfer substrate 63c, an air flow is generated in a direction that collides with the bottom transfer substrate 63a (downward in the drawing). As a result, the toner T and air are sprayed on the lowest flat portion of the bottom transport substrate 63a (see the downward white arrow in FIG. 7), and the toner T flows in the normal direction of the toner transport surface TTS. Then, an alternating current of the toner T occurs between the surface layer portion and the lower layer portion.

  The standing plate portion 672 may be provided in parallel with the vertical line, but may be provided so as to be inclined with respect to the vertical line as shown in FIG. That is, the standing plate portion 672 is provided so that the gap between the standing plate portion 672 and the lower conveyance substrate 63c (a flat plate portion below the developing roller 62) becomes narrower as it goes downward. Also good. As a result, the momentum of the airflow that collides with the flat bottom portion of the bottom conveyance substrate 63a can be ensured to such an extent that the alternating current of the toner T can be generated satisfactorily between the surface layer portion and the lower layer portion.

  In addition, in the elements constituting the means for solving the problems of the present invention, the elements expressed in terms of function and function are the specific structures disclosed in the above-described embodiments and modifications, It includes any structure that can realize this action / function. Furthermore, the contents (including the specification and the drawings) of each publication cited in this specification can be incorporated as part of this specification.

DESCRIPTION OF SYMBOLS 1 ... Laser printer 2 ... Paper conveyance mechanism 3 ... Photosensitive drum 4 ... Charger 5 ... Scanner unit 6 ... Toner supply apparatus 60 ... Main body casing 61 ... Toner accommodation cartridge 62 ... Developing roller 63 ... Conveyance board 63a ... Bottom conveyance board 63b ... Upper transfer board 63c ... Lower transfer board 631 ... Transfer electrode 64 ... Transfer power supply circuit 65 ... Recovery power supply circuit 66 ... Development bias power supply circuit 67 ... Shielding plate 67a ... Restriction end 671 ... Horizontal flat plate part 671a ... Restriction end 672 ... Standing plate portion 672a ... Lower end portion 68 ... Toner input state control means 69 ... Air duct 69a ... Air ejection opening T ... Toner TTD ... Toner transfer direction TTP ... Toner transfer path TTS ... Toner transfer surface

JP 2001-209246 A JP 2002-287495 A JP 2003-295615 A JP 2008-70587 A JP 2009-3307 A

Claims (3)

An electric field generated along with the application of a multiphase AC voltage to a plurality of transport electrodes arranged along a developer transport path having a longitudinal direction along the main scan direction and intersecting the main scan direction, In the developer electric field transport device configured to transport the charged powdery developer along the developer transport path,
A developer transport body configured to support the plurality of transport electrodes along a developer transport surface that is a surface facing the developer transport path;
In the developer transporting on the developer transport surface, the developer transport so that an alternating current of the developer is generated between a surface layer portion and a lower layer portion close to the developer transport surface. A developer alternating current generating means for generating a flow of the developer along a normal direction of the surface;
A developer electric field conveying apparatus comprising: The developer electric field transport device according to claim 1,
The developer AC generating means
A developer electric field conveying apparatus configured to spray the developer and / or air toward the developer conveying surface. The developer electric field transport device according to claim 2,
The developer AC generating means
A developer electric field conveying device, characterized in that the developer electric field conveying means is configured to generate an air current that collides with the developer conveying surface.

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