JP3203793B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
The present invention relates to an image forming apparatus that can be used for a plotter, a facsimile, and the like.

[0002]

2. Description of the Related Art An image recording apparatus for obtaining an image on a support by controlling the passage of toner particles through an aperture by applying an image signal to an electrode having an aperture has been proposed in US Pat. No. 3,689,935. ing. This image recording apparatus has a continuous shield electrode formed on one surface across an insulator layer, and a plurality of control electrodes insulated from each other formed on the other surface. means for providing the aperture electrode member having a aperture for one column also reduced through the three layers for each of the plurality of control electrodes, selectively potential between the control electrode and the shield electrode, the potential applied Means for supplying charged toner particles such that the flow of toner particles through the aperture is modulated by the means, and means for positioning the support in the particle flow path by relatively moving the support and the aperture electrode body. Have been.

[0003] For example, US Patent Application No. 946937
Nos. 926129, 140266 and 9
In the image forming apparatus described in Japanese Patent No. 26158, an aperture electrode body is disposed with a control electrode facing the support and a shield electrode facing the toner supply side.

On the other hand, in Japanese Patent Application Laid-Open No. 2-226261, the efficiency of the voltage applied to the control electrode at the time of off is established by disposing the aperture electrode body with the shield electrode facing the support and the control electrode facing the toner supply side. Is about four times higher.

[0005] Here, the OFF state means a time point when a blank portion of an image on which toner is not adhered is formed on the support. On the other hand, if the ON state is ON, a toner image is formed on the support. It means the time when it is done.

[0006]

However, the conventional image recording apparatus as described above employs a method in which toner is supplied in the form of a cloud in the form of a cloud, and is supplied to the vicinity of the aperture. In exchange for the toner moving away from the vicinity of the aperture and increasing the efficiency at the time of OFF, the cloud density of the toner near the aperture becomes extremely low at the time of ON following the time of OFF. Therefore, there is a disadvantage that the responsiveness at the time of the ON state following the OFF state becomes extremely poor.

Further, the cloud-shaped toner adheres to the control electrode due to the image force or the like, and sometimes blocks the aperture.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to disclose charged particles such as toner on a carrier.
An image forming device that can fly with good responsiveness
Have a simple configuration of charged particles flying from each opening.
It is an object of the present invention to provide an image forming apparatus capable of making the amount substantially uniform .

[0009]

In order to achieve the above object, an image forming apparatus according to the first aspect of the present invention comprises a plurality of opening devices.
Insulating substrate with openings formed, and each opening in the substrate
And a control electrode formed on one side of the substrate.
A carrier for transporting charged particles to the opening,
Back electrode provided on the opposite side of the plate from the carrier
Generating an electric field between the carrier and the control electrode.
First electric field generating means, the carrier and the back electrode
Second electric field generating means for generating an electric field between
The charged particles transported by the carrier are transferred to the first
The electric field generated by the electric field generating means and the second electric field generating means
Fly from the opening by the electric field by the
Transferred onto the recording medium transported between the back electrode
To form a desired image on the recording medium.
As an object, in particular, the control electrode may
It is characterized in that it is formed on the holding body side.

[0010] The image forming apparatus according to claim 2 is
The carrier has an urging means for urging the substrate.
It is characterized by.

Further, the image forming apparatus according to claim 3.
The biasing means includes an elastic body inside the carrier.
It is characterized by having been constituted by.

[0012]

[Action] Oite to <br/> image forming apparatus according to claim 1 of the present invention having the above configuration, it is housed on one side of the substrate charged
The particles are transported to the opening by the carrier, and
The electric field generated by the field generating means and the second electric field generating means
Flying from the opening, transported between the substrate and the back electrode
Transfer the image on the recording medium and place the desired image on the recording medium.
But the control electrode is formed on the carrier side of the substrate.
Therefore, the electric field intensity generated by the first electric field generating means
Can increase the responsiveness of charged particles from the carrier
Can fly well.

Further, in the image forming apparatus according to the present invention,
And the carrier has an urging means for urging the substrate.
Therefore, the contact pressure of the carrier with respect to the substrate is
It becomes substantially uniform, and the amount of charged particles flying from each opening
It can be uniform.

Further, in the image forming apparatus according to the third aspect,
The urging means may include an elastic body inside the carrier.
With a simple structure
The contact pressure of the supporting member to be made substantially uniform
The amount of charged particles flying from each opening can be
It can be made substantially uniform by the configuration.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of the image forming apparatus. FIG.
In the back spaced 1mm above the aperture electrode 1
The back electrode roller 32 as an electrode rotates to record the recording medium.
A housing (not shown) for transporting the support 31 as a body
Is rotatably disposed. A toner supply device 20 is provided below the aperture electrode body 1. Support 3
A fixing device 35 is provided at the destination of the operation.

The toner supply device 20 is configured as follows.

A toner case 21 accommodates toner 26 as charged particles, in which a supply roller 23 and a carrier
Toner carrying roller 22 is disposed in parallel as. The toner carrying roller 22 includes an urging unit and an elastic body.
A nickel sleeve 25 having a thickness of 20 μm is adhered around all the sponge rollers 24.

The toner regulating blade 27 is arranged so as to press against the sleeve 24 on the toner carrying roller 22.

As shown in detail in FIG. 2, the aperture electrode body 1 has an aperture 120 having a diameter of 120 μm on an insulating sheet 2 as a polyimide substrate having a thickness of 30 μm.
A control electrode 3 which is formed in rows and surrounds the aperture for each aperture is provided on the upper side, and a continuous shield electrode 4 is provided on the lower side.

As shown in FIG. 1, the aperture electrode body 1 is arranged such that the shield electrode 4 is opposed to the support 31 and the control electrode 3 is in contact with the toner on the toner carrying roller at the aperture position.

Between the control electrode 3 and the sleeve 24, a first
A control voltage application circuit 8 as an electric field generating means is connected. The control voltage drive circuit 8 is configured to output 0 V or −30 V according to an image signal. A second voltage of +2.2 kV is applied between the back electrode roller 32 and the sleeve 24 .
A DC power supply 33 as an electric field generating means is connected.

The operation of the above configuration will be described in detail below.

By rotation of the toner carrying roller 22 and the supply roller 23 in the direction of the arrow, the toner 26 is rubbed from the supply roller 23 to the sleeve 25 of the toner carrying roller 22, is negatively charged, and is carried on the sleeve.
The carried toner 26 is thinned by the layer regulating blade 27 and is conveyed toward the vicinity of the aperture electrode body by the rotation of the toner carrying roller 22. Here, the toner on the sleeve is supplied under the aperture while being rubbed by the aperture electrode body 1, and the sleeve 25 and the control electrode 3 of the aperture electrode body 1 are separated by 10 μm by this toner layer.

Here, 0 V is applied from the control voltage application circuit 8 to the control electrode 3 corresponding to the image portion according to the image signal. As a result, near the aperture corresponding to the image part,
Due to the potential difference between the back electrode and the sleeve, lines of electric force are formed from the back electrode side of the aperture toward the sleeve. The negatively charged toner receives an electrostatic force in the direction of higher potential, passes through the control electrode from the sleeve, is drawn out to the shield electrode side, and is further deposited on the support to form pixels.

A voltage of -30 V is applied from the control voltage application circuit 8 to the control electrodes corresponding to the non-image portions. As a result, lines of electric force from the sleeve to the control electrode are formed by the potential difference between the control electrode and the sleeve near the aperture corresponding to the non-image portion. Since the potential between the sleeve 24 and the control electrode is lower from the sleeve toward the control electrode, the negatively charged toner does not pass through the aperture.

The support is fed by one pixel in a direction perpendicular to the aperture row during the pixel formation time of one row. By repeating the above process while the support is transported by its length, a toner image can be formed on the entire surface of the support.

In the above process, the responsiveness is fast because the toner is always supplied in contact with the aperture electrode.
In addition, since the control electric field generated by the control electrode 3 is formed between the control electrode 3 and the sleeve 25 that are close to each other, the control electric field can be controlled with a low control voltage.

Further, since the toner slides on the control electrode of the aperture electrode body 1, the toner does not accumulate on the control electrode 3 and does not block the aperture.

However, in the above embodiment, the shield electrode 4 of the aperture electrode body 1 shields the electric field to prevent the electric field formed by the back electrode 32 from acting on the toner on the toner carrier other than under the aperture. It is not necessary for the purpose of the present invention.

[0031]

As is apparent from the above description, according to the image forming apparatus of the first aspect of the present invention , the substrate
The charged particles stored on one side are opened by the carrier.
And the first electric field generating means and the second electric field generating
Fly from the opening by the electric field by means, the substrate and the back
Transfer to the recording medium transported between the electrodes and
Is formed on the recording medium, but the control electrode is
Since it is formed on the carrier side, the first electric field generating means
Therefore, the generated electric field strength can be increased,
The particles can be made to fly from the carrier with good responsiveness.

Further, in the image forming apparatus according to the second aspect,
And the carrier has an urging means for urging the substrate.
Therefore, the contact pressure of the carrier with respect to the substrate is
It becomes substantially uniform, and the amount of charged particles flying from each opening
It can be uniform.

Further, in the image forming apparatus according to the third aspect,
The urging means may include an elastic body inside the carrier.
With a simple structure
The contact pressure of the supporting member to be made substantially uniform
The amount of charged particles flying from each opening can be
It can be made substantially uniform by the configuration.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a main part of an image forming apparatus according to the present invention.

FIG. 2 is a perspective view showing details of an aperture electrode body used in the image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aperture electrode body 3 Control electrode 6 Aperture 8 Control voltage application circuit 22 Toner carrying roller 32 Back electrode roller 33 DC power supply

Claims (3)

(57) [Claims] 1. An insulating substrate having a plurality of openings formed therein.
And a control electrode formed for each opening of the substrate, and charged particles stored on one side of the substrate.
And a back provided on the opposite side of the substrate with respect to the substrate.
A surface electrode, and a third electrode for generating an electric field between the carrier and the control electrode.
An electric field generating means for generating an electric field between the carrier and the back electrode;
2 electric field generating means , wherein the charged particles carried by the carrier are
The electric field generated by the electric field generating means and the second electric field generating means
Fly from the opening by the electric field, and
Transferred onto the recording medium transported between the back electrode
An image forming method for forming a desired image on the recording medium.
In the forming apparatus, the control electrode is formed on the substrate side of the substrate.
An image forming apparatus. 2. The urging device for urging the substrate to urge the substrate.
2. The image form according to claim 1, further comprising means.
Equipment. 3. The urging means includes an elastic member inside the carrier.
Characterized by having a sexual body
The image forming apparatus according to claim 2.