JP2013193801A - Powder conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To handle a charged powder which is an object to be conveyed well.
A powder transfer device according to the present invention includes a plurality of transfer electrodes arranged along a predetermined transfer path, an electrode support member provided to support the plurality of transfer electrodes on the surface, and an electrode. And an electrode coating layer provided to cover the surface of the support member and the plurality of transport electrodes. A feature of the present invention is that the above-mentioned electrode coating layer is a uniform ferroelectric polymer layer having a relative dielectric constant of 8 or more. Specifically, for example, a ferroelectric amorphous polymer layer can be used as the electrode coating layer.
[Selection] Figure 2

Description

  The present invention relates to a powder conveying apparatus configured to convey charged powder by a traveling wave electric field.

  As this type of apparatus, a number of apparatuses that transport a developer (toner) in an image forming apparatus are conventionally known (for example, JP-A-2002-82524 and JP-A-2002-287495). . In such an apparatus, a large number of linear electrodes are arranged in a row on an insulating substrate.

  According to the above-described configuration, a traveling wave electric field is formed by sequentially applying a multiphase AC voltage to the multiple linear electrodes. The charged toner is conveyed in a predetermined direction by the action of the traveling wave electric field.

  In the conventional apparatus configuration as described above, when charge-up occurs on the substrate during transportation, it becomes difficult to handle the charged powder that is the object to be transported satisfactorily. The present invention has been made to cope with such a problem.

The powder conveying apparatus which is the object of the present invention is configured to convey charged powder by a traveling wave electric field. This powder conveying device
A plurality of transport electrodes arranged along a predetermined transport path;
An electrode support member provided to support a plurality of the transport electrodes on the surface;
An electrode coating layer provided on the surface so as to cover the surface of the electrode support member and the plurality of transport electrodes;
It has.

  Specifically, for example, the powder conveyance device may be disposed so as to face a supply target having a conductive (or semiconductive) powder carrying surface while being closest to each other at a predetermined supply position. Good. In this case, the supply target is configured to be able to carry the powder on the powder carrying surface at the supply position. And this powder conveying apparatus is comprised so that the said powder may be supplied to the said supply object by conveying the said powder toward the said supply position.

  A feature of the present invention is that the electrode coating layer is a uniform ferroelectric polymer layer having a relative dielectric constant of 8 or more. Specifically, for example, a ferroelectric amorphous polymer layer can be used as the electrode coating layer.

1 is a side view showing a schematic configuration of a laser printer which is 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 of the present embodiment shown in FIG. 1. It is the sectional side view to which the electric field conveyance board | substrate shown by FIG. 2 was expanded. It is a graph which shows an example of the output waveform of each power supply circuit shown by FIG.

  Embodiments of the present invention will be described below with reference to the drawings. It should be noted that various modifications (modifications) that can be made to the present embodiment, if inserted during the description of the embodiment, hinders understanding of the description of the consistent embodiment, and are summarized at the end. It is described.

<Configuration of laser printer>
FIG. 1 is a side view showing a schematic configuration of a laser printer 1 which is an image forming apparatus 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. Sheet-like paper P is stored in a stacked state 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 a predetermined paper transport path PP.

  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 (z-axis direction in the drawing: also referred to as “paper width direction”), and an electrostatic latent image is formed by a potential distribution. In addition, the toner T (see FIG. 2) is carried at a position corresponding to the electrostatic latent image. The photosensitive drum 3 is driven to rotate in a direction (clockwise) indicated by an arrow in the drawing with an axis parallel to the main scanning direction as a center, so that a sub-scanning direction (typically perpendicular to the main scanning direction) Specifically, the electrostatic latent image carrying surface LS is configured to move along the x-axis direction in the drawing.

  The charger 4 is disposed so as to face the electrostatic latent image carrying surface LS. The charger 4 is a corotron type or scorotron type charger, and is configured to uniformly positively charge the electrostatic latent image carrying surface LS.

  The scanner unit 5 generates a laser beam LB of a predetermined wavelength band that is modulated based on image data (the ON / OFF of light emission is controlled depending on the presence or absence of pixels), and scan position on the electrostatic latent image carrying surface LS. An image is formed by the SP, and the image forming position is moved (scanned) at a constant speed along the main scanning direction. Here, the scan position SP is provided at a position downstream of the charger 4 and upstream of the toner supply device 6 in the moving direction of the electrostatic latent image carrying surface LS due to the rotation of the photosensitive drum 3. .

  The toner supply device 6 is disposed below the photosensitive drum 3 so as to face the electrostatic latent image carrying surface LS. The toner supply device 6 supplies the positively charged toner T (see FIG. 2) to the photosensitive drum 3 at the development position DP (the position where the toner supply device 6 is closest to and faces the electrostatic latent image carrying surface LS). It is configured to be supplied to (electrostatic latent image carrying surface LS). Here, in this embodiment, the toner T is a positively chargeable, nonmagnetic one-component, black powdery dry developer. The detailed configuration of the toner supply device 6 will be described later.

  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 a 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 across the paper transport path PP at the transfer position TP, and rotates in the direction indicated by the arrow (counterclockwise) in the drawing. It is designed to be driven. The transfer roller 22 is applied with a predetermined transfer bias for transferring the toner T (see FIG. 2) attached to the electrostatic latent image carrying surface LS to the paper P between the transfer drum 22 and the photosensitive drum 3. These are electrically connected to a transfer bias power supply circuit (not shown).

<< Toner Supply Device >>
FIG. 2 is an enlarged side sectional view of the toner supply device 6 shown in FIG. 1 (a sectional view taken along a plane with the main scanning direction as a normal line). Referring to FIG. 2, the toner supply device 6 includes an electric field transport substrate 61, a developing roller 62, a transport bias power supply circuit 63, and a development bias power supply circuit 65.

  The electric field transport substrate 61 is disposed so as to face the toner carrying surface TCS, which is a cylindrical peripheral surface of the developing roller 62, at the toner carrying position TCP with a gap of a predetermined interval and closest. The electric field transport substrate 61 is configured to be capable of transporting the toner T along the toner transport path TTP by a traveling wave electric field by applying a transport bias including a DC voltage component and a multiphase AC voltage component ( Details of the internal configuration of the electric field transport substrate 61 will be described later.)

  Here, the above-mentioned “toner transport path TTP” is a transport path of the toner T formed along the toner transport surface TTS which is the surface of the electric field transport substrate 61. It should be noted that the tangential direction at an arbitrary position in the toner transport path TTP and the direction in which the toner T is actually transported by the transport bias described above (the toner reservoir TR that is a region in which the toner T before electric field transport is stored) The direction from the toner to the toner carrying position TCP is hereinafter referred to as “toner transport direction TTD”.

  The developing roller 62 is a roller-like member having a toner carrying surface TCS that is a cylindrical circumferential surface, and is provided to face the photosensitive drum 3 at the developing position DP. That is, the developing roller 62 is arranged so that the toner carrying surface TCS faces the electrostatic latent image carrying surface LS on the photosensitive drum 3 at a development position DP with a gap of a predetermined interval. The developing roller 62 is configured to carry the toner T conveyed to the toner carrying position TCP by the electric field carrying substrate 61 on the toner carrying surface TCS at the toner carrying position TCP.

  The developing roller 62 is formed such that at least the surface layer portion constituting the toner carrying surface TCS has conductivity or semiconductivity. Specifically, for example, the developing roller 62 can be formed of a cylindrical metal. Alternatively, the developing roller 62 may be formed by providing a semiconductive rubber or synthetic resin surface layer on the outer periphery of a cylindrical metal.

  Further, in the present embodiment, the developing roller 62 is rotationally driven in a rotational direction such that the moving direction of the toner carrying surface TCS that is the peripheral surface thereof is the same as the toner transport direction TTD in the vicinity of the toner carrying position TCP. It has become so.

  FIG. 3 is an enlarged side sectional view of the electric field transport substrate 61 shown in FIG. Referring to FIG. 3, the electric field transport board 61 is a thin plate-like member, and has the same configuration as the flexible printed wiring board. Specifically, the electric field transport substrate 61 includes a transport electrode 611, a support film layer 612, and an electrode coating layer 613.

  The transport electrode 611 is a linear wiring pattern having a longitudinal direction parallel to the main scanning direction, and is formed of a copper foil. The plurality of transport electrodes 611 are arranged along the toner transport path TTP and are arranged in parallel to each other.

  In the present embodiment, the transport electrodes 611 arranged in large numbers along the toner transport path TTP are connected to the same power supply circuit every third. That is, the transfer electrode 611 connected to the power supply circuit VA, the transfer electrode 611 connected to the power supply circuit VB, the transfer electrode 611 connected to the power supply circuit VC, the transfer electrode 611 connected to the power supply circuit VD, and the power supply circuit VA The transport electrodes 611 connected, the transport electrodes 611 connected to the power supply circuit VB, the transport electrodes 611... Connected to the power supply circuit VC are sequentially arranged along the toner transport path TTP (note that these The power supply circuits VA to VD are components of the carrier bias power supply circuit 63 shown in FIG.

  The plurality of transport electrodes 611 are formed on the surface of the support film layer 612. The support film layer 612 corresponding to the electrode support member of the present invention is a flexible film and is made of an insulating synthetic resin such as a polyimide resin.

  The electrode coating layer 613 is uniformly formed of a uniform ferroelectric polymer having a relative dielectric constant of 8 or more, specifically, a ferroelectric amorphous polymer (that is, uneven distribution of components or dispersion of fine particles is formed). And a surface of the support film layer 612 where the transport electrode 611 is provided, and the transport electrode 611. As the ferroelectric polymer constituting the electrode coating layer 613, for example, polyvinylidene difluoride can be used.

  The electrode coating layer 613 is provided on the outermost layer of the electric field transport substrate 61. That is, the toner transport surface TTS, which is the surface of the electrode coating layer 613, is formed as a smooth surface with very few irregularities so that the toner T can be transported smoothly.

  Referring to FIG. 2 again, the electric field transport substrate 61 is electrically connected to the transport bias power supply circuit 63. The transport bias power supply circuit 63 outputs a four-phase AC transport bias (see FIG. 4) for transporting the toner T in the toner transport direction TTD along the toner transport path TTP.

  The developing roller 62 is electrically connected to the developing bias power supply circuit 65. The developing bias power supply circuit 65 applies a developing bias between the developing roller 62 and the photosensitive drum 3 (more precisely, between the exposed portion of the potential VL on the electrostatic latent image carrying surface LS and the toner carrying surface TCS). In order to apply the voltage, a necessary voltage is output.

<Action and effect>
Next, an outline of the operation according to the configuration of the above-described embodiment will be described together with the operations and effects.

  In the configuration of the present embodiment, the positively charged toner T is transported by the electric field transport substrate 61 from the toner reservoir TR to the toner carrying position TCP in the toner transport direction TTD along the toner transport path TTP. The In the vicinity of the toner carrying position TCP, the toner T is carried on the toner carrying surface TCS by the action of an electric field formed between the developing roller 62 and the electric field carrying substrate 61 (carrying electrode 611). .

  In this regard, in the configuration of the present embodiment, the electrode coating layer 613 provided as the outermost layer in the electric field transport substrate 61 is a uniform ferroelectric amorphous polymer layer having a relative dielectric constant of 8 or more. As a result, a virtual capacitance formed between the transport electrode 611 and the toner carrying surface TCS increases. For this reason, “occurrence of fluctuation of the toner flying electric field between the transport electrode 611 and the toner carrying surface TCS due to the charge-up of the toner transport surface TTS during the transport of the toner T” is suppressed as much as possible. Therefore, according to this configuration, the toner T is favorably carried on the toner carrying surface TCS.

  Here, the evaluation results when the characteristics of the electrode coating layer 613 are changed will be described with reference to Table 1. In Table 1, “Composition” indicates the material of the electrode coating layer 613, “Thickness on electrode” indicates the thickness of the electrode coating layer 613 on the transport electrode 611, and “εr” is the ratio of the electrode coating layer 613. The dielectric constant is shown. “Supported amount stability” is a result of evaluating the supported amount stability from the degree of variation in the supported amount of toner T per unit area on the toner supporting surface TCS during continuous operation.

  As is clear from the results shown in Table 1, in Examples 1 and 2, good loading amount stability was obtained.

  By the way, the thing of Example 1 and 2 was formed in the amorphous state which does not have a crystal layer. Therefore, as a reference example, the same material as in Examples 1 and 2 was crystallized by heat treatment (annealing). As a result, even in the case of this reference example, good loading amount stability was obtained.

  However, regarding the uniformity of the amount of toner T on the toner carrying surface TCS in the main scanning direction, Examples 1 and 2 in an amorphous state having no crystal layer are more than those of the reference example crystallized by heat treatment. Was better. That is, according to the configurations of Examples 1 and 2 using a uniform ferroelectric amorphous polymer layer having a relative dielectric constant of 8 or more, good carrying amount stability and uniformity of carrying amount in the main scanning direction are obtained. Both are achieved.

<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.

  Needless to say, the modifications are not limited to those listed below. In addition, a plurality of modified examples can be applied in a composite manner as appropriate within a technically consistent range.

  The present invention (especially those expressed in terms of action and function in each component constituting the means for solving the problems of the present invention) is based on the description of the above embodiment and the following modifications. It should not be interpreted in a limited way. Such a limited interpretation (especially rushing applications under the principle of prior application) unfairly harms the applicant's interests, but improperly imitators, and is intended to protect and use the invention. Contrary to the purpose of patent law, it is not allowed.

  The application target of the present invention is not limited to developer conveyance in the image forming apparatus. Further, when the present invention is applied to an image forming apparatus, the object 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.

  As the exposure light source, other than the laser scanner (LED, EL (electroluminescence) element, phosphor, etc.) can be suitably used. In this case, the “main scanning direction” is a direction parallel to the arrangement direction of the light emitting elements (LEDs and the like). 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.

  As the waveform of the voltage generated by each of the power supply circuits VA to VD, an arbitrary waveform such as a sine wave shape or a triangular wave shape can be used other than the rectangular wave shape. Also, a three-phase alternating current can be used instead of the four-phase alternating current.

  The developing roller 62 is rotationally driven in such a rotational direction that the moving direction of the toner carrying surface TCS which is the peripheral surface thereof is opposite to the toner transport direction TTD in the vicinity of the toner carrying position TCP. Good.

  Other modifications not specifically mentioned are naturally included in the technical scope of the present invention without departing from the essential part of the present invention.

  In addition, in each element constituting the means for solving the problems of the present invention, elements expressed functionally and functionally include 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 drawings) of each publication cited in the present specification may be incorporated as part of the specification.

DESCRIPTION OF SYMBOLS 1 ... Laser printer 2 ... Paper conveyance mechanism 3 ... Photosensitive drum 4 ... Charger 5 ... Scanner unit 6 ... Toner supply apparatus 61 ... Electric field conveyance board | substrate 611 ... Conveyance electrode 612 ... Support film layer 613 ... Electrode coating layer 62 ... Developing roller 63 ... transport bias power supply circuit DP ... development position LS ... electrostatic latent image carrying surface T ... toner TCP ... toner carrying position TCS ... toner carrying surface TTD ... toner transport direction TTP ... toner transport path TTS ... toner transport surface

JP 2002-82524 A JP 2002-287495 A

Claims (2)

A powder conveying device configured to convey charged powder by a traveling wave electric field,
A plurality of transport electrodes arranged along a predetermined transport path;
An electrode support member provided to support a plurality of the transport electrodes on the surface;
An electrode coating layer provided on the surface so as to cover the surface of the electrode support member and the plurality of transport electrodes;
With
The powder coating apparatus, wherein the electrode coating layer is a uniform ferroelectric polymer layer having a relative dielectric constant of 8 or more. The powder conveying apparatus according to claim 1,
The powder coating apparatus, wherein the electrode coating layer is amorphous.

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