JPH06286206A - Direct recording device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a direct recording device capable of obtaining stable recording characteristics by increasing the chargeability of toner. A charging promoting layer 15 made of an electron-donating charge transport material is provided on the surfaces of the layer regulating blade 18 and the toner carrying roller 14 of the toner supply device 10, and the layer regulating blade 18 and the toner carrying roller 14 are provided. Between
A DC power supply 30 that generates a negative voltage is connected. Therefore, the carried toner 16 is thinned by the layer regulation blade 18, and electrons are sufficiently supplied to the toner 16 from the DC power source 24 through the charging promotion layer 15 so that the toner is sufficiently charged. The charge promoting layer 15 dramatically increases the charge injection efficiency with respect to the toner, thereby increasing the charge efficiency. As described above, the toner becomes a charge group having a uniform charge amount without reverse polarity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct recording device mounted on a copying machine, a printer, a plotter, a facsimile or the like.

[0002]

2. Description of the Related Art Conventionally, an image recording apparatus for controlling the passage of toner particles through an aperture to obtain an image on a support by applying an image signal to an electrode having an aperture has been proposed in US Pat. No. 3,689,935. ing.

According to this proposal, a reference electrode which is continuous on one surface with a layer of an insulator interposed therebetween and a plurality of control electrodes which are insulated from each other on the other surface are provided, and three control electrodes are provided for each insulated control electrode. Aperture electrode body having apertures formed through the layers and arranged in at least one row, a means for selectively applying a potential to the control electrode and the reference electrode, and a passage through the aperture depending on the applied potential It comprises means for projecting charged particles so as to modulate the flow of toner particles, and means for relatively moving the support and the aperture electrode body to position the support in the particle flow path.

However, according to this apparatus, in addition to the poor recording quality due to the clogging of the aperture due to toner,
The recording speed could not be increased sufficiently.

The applicant of the present invention further studied,
As already filed in the application No. 254494, an image recording apparatus has been proposed in which the recording characteristics can be greatly improved by disposing the carrier holding the toner and the recording electrode in contact with each other. According to this apparatus, the image quality is remarkably improved, and the image recording apparatus can be downsized and the cost can be reduced.

[0006]

However, although the conventional image forming apparatus has excellent resolution, it is not possible to sufficiently improve the recording speed and recording stability. That is, in the conventional image forming apparatus, the toner on the toner carrying roller is thinned by a blade-like or roller-like layer regulating member, and at the same time, the toner is charged, but the carrying roller and the layer regulating member are made of metal. It was done. Therefore, the charging efficiency is extremely low, and the toner which is not sufficiently charged has poor controllability and the recording characteristics cannot be improved.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a direct recording apparatus which can obtain stable recording characteristics by increasing the chargeability of toner.

[0008]

In order to achieve this object, a direct recording apparatus of the present invention comprises at least a carrier for supporting toner and a layer regulating member for charging the toner on the toner carrier. The recording apparatus is characterized in that a charge promoting layer is provided on either the layer regulating member or the carrier.

Further, the charge promoting layer is characterized by being composed of a charge control agent.

Further, the charge promoting layer is composed of a charge transporting agent.

[0011]

According to the direct recording apparatus of the present invention having the above structure, the toner can be sufficiently charged by the charging promoting layer provided on either the layer regulating member or the carrier.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an outline of an image forming apparatus to which the direct recording apparatus of the present invention is applied.
A cylindrical back electrode roller 22 is rotatably disposed on a chassis (not shown) with a gap of 1 mm on the upper side of, and conveys the support body 20 inserted in the gap. Is configured to get. Also, the aperture electrode body 1
On the lower side, a toner supply device 10 is arranged along the longitudinal direction of the aperture electrode body 1, and further, a fixing device 26 is arranged at the destination of the support body 20 being conveyed. Has been done.

Next, the respective components will be described in detail. In the toner supply device 10, the toner case 11 also serving as a housing of the entire device, the toner 16 housed in the toner case 11, and the supply roller 12 are provided. And a toner carrying roller 14 and a toner layer regulating blade 18.

Here, the toner carrying roller 14
Carries toner 16 and conveys it toward the aperture electrode body 1. The supply roller 12 supplies the toner 16 to the toner carrying roller 14.
Then, the supply roller 12 and the toner carrying roller 14
Are rotatably supported by the toner case 11 in the direction of the arrow shown in the figure, and the two are arranged in parallel with a slight gap. Further, the toner layer regulating blade 18 is
The amount of toner 16 carried by the toner carrying roller 14 is adjusted so as to be uniform on the roller surface, and the toner carrying roller 14 is pressed against the toner carrying roller 14.

Here, the layer regulating blade 18 and the carrying roller 1
4 will be described with reference to FIG. FIG. 3 is a detailed cross-sectional view showing the vicinity of the carrying roller and the layer regulating blade.

On the surfaces of the layer regulating blade 18 and the toner carrying roller 14, a charge promoting layer 15 made of an electron donating charge transport material is provided. For the electron-donating charge-accelerating layer 15, a heterocyclic compound such as oxadiazole, oxazole, or pyrazoline, a hydrazone-based polymer, triphenylmethane, or an arylamine-based polymer material can be used. A DC power supply 30 that generates a negative voltage is connected between the layer regulating blade 18 and the toner carrying roller 14.

In the aperture electrode body 1, as shown in FIG. 2, a plurality of apertures 6 having a diameter of 100 μm are formed in a row on an insulating sheet 2 made of polyimide having a thickness of 25 μm, and on the upper surface side of the insulating sheet 2. A control electrode 4 having a thickness of 1 μm is formed on the periphery of the opening of each aperture 6. As shown in FIG. 3, the aperture electrode body 1 is arranged so that the control electrode 4 faces the support body 20 side and the insulating sheet 2 contacts the toner 16 on the toner carrying roller 14 at the position of the aperture 6. It is set up.

A control voltage applying circuit 8 is connected between the control electrode 4 and the toner carrying roller 14.
The control voltage application circuit 8 is configured to apply a voltage of 0 V or +50 V to the control electrode 4 based on the image signal.

Further, a back electrode 22 is arranged behind the support.

Further, a DC power source 24 is connected between the back electrode roller 22 and the toner carrying roller 14, and this DC power source is + with respect to the back electrode roller 22.
A voltage of 1 kV can be applied.

Next, the operation of the image forming apparatus configured as described above will be described.

First, the toner 16 sent from the supply roller 12 is rubbed by the toner support roller 14 and the supply roller 12 in the direction of the arrow shown in FIG. The toner is charged and carried on the toner carrying roller 14. At this point of time, the toner is not sufficiently charged, so that the toner of the opposite polarity is present and the distribution of the amount of charge is very broad.

The carried toner 16 is thinned and charged by the layer regulating blade 18. That is,
The toner 16 is sufficiently supplied with electrons from the DC power supply 24 via the charging promotion layer 15 and the toner is sufficiently charged. Conventionally, the energy potentials have not been sufficiently matched, but by disposing the charge promoting layer 15 made of an electron donating charge transport material, the charge injection efficiency into the toner is dramatically increased and the charge efficiency is increased. As described above, the toner becomes a charge group having a uniform charge amount without reverse polarity.

The toner 16 is conveyed toward the aperture electrode body 1 by the rotation of the toner carrying roller 14. Then, the toner on the toner carrying roller 14 is supplied to the bottom of the aperture 6 while being rubbed by the insulating sheet 2 of the aperture electrode body 1.

Here, in accordance with the image signal, the control voltage applying circuit 8 adds + to the control electrode 4 corresponding to the image portion.
A voltage of 50V is applied. As a result, an electric force line from the control electrode 4 toward the toner carrying roller 14 is formed in the vicinity of the aperture 6 corresponding to the image portion due to the potential difference between the control electrode 4 and the toner carrying roller 14. As a result, the negatively charged toner receives an electrostatic force in the direction of higher electric potential, passes through the aperture 6 from the toner carrying roller 14, and is drawn out to the control electrode 4 side.

The extracted toner 16 is further supported by the electric field formed between the supporting body 20 and the aperture electrode body 1 by the voltage applied to the back electrode 22 to form the supporting body 2.
It flies toward 0 and deposits on the support 20 to form pixels. At this time, since the toner is sufficiently charged as described above, the electric field control is sufficiently effective and good recording characteristics can be obtained.

A voltage of 0V is applied from the control voltage application circuit 8 to the control electrode 4 corresponding to the non-image portion.
As a result, since no electric field is formed between the toner carrying roller 14 and the control electrode 4, the toner carrying roller 1
The toner 16 on 4 does not pass through the aperture 6 because it is not subjected to electrostatic force.

Further, the support 20 is fed by one pixel in the direction perpendicular to the aperture row while the toner 16 forms one row of pixels on the surface thereof. Then, the toner image is formed on the entire surface of the support 20 by repeating the above process. Then, the formed toner image is fixed on the support 20 by the fixing device 26.

FIG. 4 shows another embodiment of the present invention. The same components as those in the above-mentioned embodiment will be designated by the same reference numerals and will be described. The charge promoting layer 15 made of an electron donating charge transport material was provided on the surface of the carrying roller, but in the case of this embodiment, the layer regulating blade 18 and the toner carrying roller 1 are provided.
A charge promoting layer 19 made of a charge control agent is provided on the surface of No. 4. In the case of this embodiment, since the toner 16 is negatively charged, an electron donating charge control agent such as a nigrosine dye, a fatty acid metal salt or a quaternary ammonium salt can be used.
When the toner is positively charged, an electron-accepting charge control agent can be used for the charging promotion layer 19, and materials such as azo metal-containing dyes, chlorinated paraffin, and chlorinated polyester can be used.

Next, the operation of the image forming apparatus configured as described above will be described.

First, the toner 16 sent from the supply roller 12 is rubbed against the toner support roller 14 by the rotation of the toner support roller 14 and the supply roller 12, and is slightly charged negatively, so that the toner support roller 12 is charged. 1
4 carried on. At this point of time, the toner is not sufficiently charged, so that the toner of the opposite polarity is present and the distribution of the amount of charge is very broad.

The carried toner 16 is thinned and charged by the layer regulating blade 18. That is,
When the toner 16 comes into frictional contact with the charging promotion layer 19, electrons are sufficiently donated from the charging promotion layer 19 and the toner is sufficiently charged. As described above, the toner becomes a charge group having a uniform charge amount without reverse polarity, the electric field control by the aperture electrode body 1 becomes sufficiently effective, and good recording characteristics can be obtained.

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention.

For example, in the above embodiment, the control voltage of the aperture corresponding to the non-image portion is set to 0V, but this may be a negative voltage. In this case, an image with less fogging can be obtained. Further, in the above embodiment, the aperture electrode body is used as the toner flow control means, but it is also possible to use, for example, a stitched electrode body as described in JP-A-1-503221.

[0036]

As is apparent from the above description, according to the direct recording apparatus of the present invention, good recording can be easily obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an image forming apparatus to which a direct recording device of the present invention is applied.

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

FIG. 3 is an enlarged view of a blade portion.

FIG. 4 is an enlarged view of a blade portion according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aperture electrode body 2 Insulating sheet 4 Control electrode 6 Aperture 8 Control voltage application circuit 14 Toner carrying roller 15 Charging promotion layer 18 Blade 24 DC power supply

Claims (3)

[Claims] 1. A direct recording apparatus comprising at least a carrier carrying toner and a layer regulating member for charging the toner on the toner carrier, wherein a charge promoting layer is provided on either the layer regulating member or the carrier. A direct recording device characterized by being provided with. 2. The direct recording device according to claim 1, wherein the charge promoting layer is composed of a charge control agent. 3. The direct recording device according to claim 1, wherein the charge promoting layer is composed of a charge transport material.