JPH08104025A - Image recording apparatus - Google Patents

Abstract

PURPOSE: To provide an inexpensive image recording apparatus imparting high contrast and capable of enhancing recording quality to a large extent. CONSTITUTION: A first supply roller 12 forms one toner carrying layer on a toner carrying roller 11 and a second supply roller 13 forms a separate toner carrying layer on the toner carrying layer already formed on the toner carrying roller 11. The toner 14 formed on the toner carrying roller 11 in a multilayered state is supplied to an aperture electrode 1 to be controlled on the basis of an image signal by the aperture electrode 1 and the toner 14 passed through the electrode 1 is guided to a support P by a rear electrode 6 to form a toner image on the support P. In this case, since the image is formed by a large amt. of toner 14, recording density is enhanced and a recording state high in contrast is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording device applied to a copying machine, a printer, a facsimile and the like.

[0002]

2. Description of the Related Art Conventionally, as an example of an image recording apparatus of this kind, an aperture electrode having an opening and modulating and controlling a flow of toner passing through the opening, and a control for applying a control voltage to the aperture electrode. A voltage applying means and a toner carrier disposed on the back surface of the aperture electrode to charge the toner, and then supplies the charged toner to the opening portion of the aperture electrode, and the toner carrier to supply the toner to the aperture. An image recording apparatus has been proposed that includes a back electrode that guides the toner that has passed through the opening of the electrode to an image forming support disposed on the surface of the aperture.

The lower the voltage applied to the aperture electrode by the control voltage applying means, the lower the cost of the driving means. Therefore, it is desirable to drive the aperture electrode with a low voltage. One means for driving the aperture electrode with a low voltage is to supply more and more uniformly charged toner to the aperture of the aperture electrode per unit time. As a specific means therefor, there is a method in which a large number of toner layers are formed on the toner carrier to increase the toner transport amount per unit time.

[0004]

However, in the above-mentioned image recording apparatus, when a large number of toner layers are formed on the toner carrier, a large amount of toner that does not come into contact with or rub against the toner carrier occurs. It will not be charged. If the uncharged toner is directly supplied to the aperture electrode, it becomes impossible to control the toner flow, the recording contrast is deteriorated, and the recording quality is remarkably deteriorated.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an image recording apparatus which has a high contrast, can significantly improve the recording quality, and is inexpensive. There is.

[0006]

To achieve this object, according to the image recording apparatus of the present invention, a toner carrier carrying charged toner and a passage of the toner supplied by the toner carrier are provided. In an image recording apparatus including a toner flow control unit that controls based on an image signal, and a back electrode that guides the toner that has passed through the toner flow control unit to a support for image formation, with respect to the toner carrier, It is provided with a plurality of toner layer forming means for separately forming toner carrying layers.

[0007]

According to the image recording apparatus of the present invention having the above-mentioned structure, one of the plurality of toner layer forming means forms one toner carrying layer on the toner carrying member, and similarly, another toner carrying layer is formed. Another toner carrying layer is formed on the toner carrying layer already formed on the toner carrying body, and in this way, as many toner carrying layers as the toner layer forming means are formed on the toner carrying body. To form multiple layers. And
Toners formed in multiple layers on the toner carrier are supplied to the toner flow control means, and the toner flow control means controls the toner flow based on the image signal. The toner image is formed on the support. In this case, since an image is formed with a large amount of toner, it is possible to increase the recording density and achieve a recording state with high contrast.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view embodying the structure of the recording apparatus of this embodiment. An insertion opening 21 for inserting a support P on which an image is to be recorded is provided on the right side of the exterior 26 of the apparatus. A support P provided with an image recorded on the left side
A take-out port 22 is provided for discharging the. Also,
The paper sensor 3 for detecting passage of the support P is provided near the insertion port 21 and the ejection port 22 in the device exterior 26.
0 and 31 are arranged. Further, inside the apparatus, an aperture electrode 1 as a toner flow control means of the present invention, a back electrode 6, and a toner charging / supplying device 10 are provided.

As shown in detail in FIG. 2, the aperture electrode 1 is composed of a plate-shaped insulating layer 2 made of an insulating material, which will be described later, and has a large number of openings 4 at equal intervals in the longitudinal direction. They are arranged in a line. Further, a large number of control electrodes 3 are provided on the upper surface of the insulating layer 2 so as to individually surround each opening 4. The insulating layer 2 is
The control electrode 3 is made of a polymer resin film having a thickness of 12.5 μm, preferably polyimide.
It is made of a metal film having a thickness of 1 μm, preferably copper. Each control electrode 3 is connected to a control voltage application circuit 5. The opening 4 is a through hole having a hole diameter of about 80 μm.

The aperture electrode 1 is supported by a base 8 provided on a chassis (not shown) in the apparatus.

Then, in the lower part of the aperture electrode 1,
A toner charging device 10 is provided. The toner charging / supplying device 10 is covered with a toner case 15 and constitutes a toner carrying member of the present invention. The toner carrying roller 11, the first supply roller 12, and the second supply roller 1
3, a first blade 16 and a second blade 17. The toner 14 is stored inside the toner case 15. The first supply roller 12 constitutes one of the toner layer forming means of the present invention, and supplies the toner 14 to the surface of the toner carrying roller 11 while frictionally charging the toner. In addition, it is configured to rotate in the direction of the arrow in the figure.
Further, the first blade 16 is pressed against the toner bearing roller 11 so as to scrape off the toner carried on the toner carrying roller 11 by the first supply roller 12 to form a thin layer of toner. .

The second supply roller 13 constitutes another one of the toner forming means of the present invention, and further rubs the toner 14 on the toner carrying roller 11 on which a thin toner layer is already formed. It is configured to rotate in the direction of the arrow in the figure so as to be supplied while being charged.
Further, the second blade 17 scrapes off the toner carried on the toner carrying roller 11 by the second supply roller 13, and further thins the toner on the toner layer formed by the first blade 16. It is pressed against the toner bearing roller 11 so as to form a layer.

A back electrode 6 is arranged above the aperture electrode 1. Further, a space of, for example, 1 millimeter is provided between the back electrode 6 and the aperture electrode 1 so that the support P can pass therethrough. A voltage of plus 1 kilovolt is applied to the back electrode 6 by the power supply 7.

The support P is conveyed by the pair of guide rollers 23 from the insertion port 21 toward the lower side of the back electrode 6, and after passing through the back electrode 6, the heat roller 24 and the press roller 25 having a heat source inside. Was transported between
The toner on the support is heat-fixed.

Next, the operation of the image recording apparatus configured as described above will be described with reference to FIG.

In the toner charging / supplying device 10, the toner 14 stored in the toner case 15 is supplied to the toner carrying roller 11 by the rotation of the first supply roller 12. At this time, the toner 14 is in contact with the toner carrying roller 11 and the first supply roller 12 and rubs against it to be negatively charged. The charge amount of the toner 14 carried on the toner carrying roller 11 is higher as it is closer to the surface of the toner carrying roller 11, and the farther one is hardly charged. Then, as the toner carrying roller 11 rotates, the toner 14 is stripped of almost uncharged toner via the first blade 16, and the well charged toner 14 becomes thin on the surface of the toner carrying roller 11. It is supported in layers.

Further, as the toner carrying roller 11 rotates and the second supply roller 13 rotates, toner is supplied to the toner carrying roller 11 carried in a thin layer. At this time, the toner 14 is collected by the second supply roller 13
While contacting, etc., they rub and become negatively charged. The charge amount of the toner 14 carried on the toner carrying roller 11 is higher as it is closer to the surface of the toner carrying roller 11, and the farther one is hardly charged. And toner 14
When the toner carrying roller 11 rotates, the toner that is almost uncharged is stripped off via the second blade 17, and the well charged toner 14 is already formed on the surface of the toner carrying roller 11 as a thin layer. The toner is carried in a thinner layer on the carried toner. As a result, a well-charged multilayer toner layer is formed. The layered toner is conveyed to the opening 4 of the aperture electrode 1.

The negatively charged toner 14 supplied to the opening 4 of the aperture electrode 1 is provided with the voltage applied to the control electrode 3 from the control voltage applying circuit 5 to the opening 4 provided corresponding to the control electrode 3. Is controlled. More specifically, the control voltage application circuit 5 based on the image data
When a voltage of plus 30 V is applied to the control electrode 3 as the toner passing voltage from the above, between the grounded toner carrying roller 11 and the control electrode 3, that is, inside the opening 4 corresponding to the control electrode, An electric field is generated so that the negatively charged toner 14 can pass through the opening 4, and the toner 14 passes through the opening 4.

When a voltage of -10 V is applied to the control electrode 3 as the toner shielding voltage from the control voltage application circuit 5, the toner is held between the grounded toner carrying roller 11 and the control electrode 3, that is, the control electrode 3. Inside the opening 4,
An electric field is generated that prevents the negatively charged toner 14 from passing through the opening 4, and the toner 14 does not pass through the opening 4.

Here, since the toner 14 is well charged in the toner charging / supplying device 10 as described above, it is reliably controlled by the aperture electrode 1 which is the toner flow control means. When toner that is not well charged is supplied to the aperture electrode 1, the force received by the electric field of the charged toner becomes small, so that the toner flow cannot be controlled well. As a result, the amount of toner that should pass through the opening decreases, and the density of the recording becomes low, or the toner that should be blocked from passing through the opening passes through the opening, causing fogging. It becomes a big thing.

Further, as described above, the toner 14 is supplied to the toner carrying roller 11 in the toner charging and supplying device 10.
Since the toner is carried in multiple layers, that is, a large amount of toner is supplied to the opening 4 of the aperture electrode 1 per unit time, a large amount of toner can pass through the opening, and therefore the recording density is high. There is an effect.

Next, the toner that has passed through the opening 4 of the aperture electrode 1 will be described.

A voltage of plus 1 kilovolt is applied to the back electrode 6 by the power source 7. By applying this voltage, an electric field is formed between the back electrode 6 and the aperture electrode 1, and the toner 14 that has passed through the opening 4 of the aperture electrode 1 along this electric field is attracted to the back electrode 6. Then, the toner 14 is applied to the conveyed support P. Then, the toner images are formed on the support P by sequentially conveying the support.

After that, the support P is conveyed in the direction of the take-out port 22, and is sandwiched by the heat roller 24 and the press roller 25, the toner 14 on the support P is heated, and the toner image is thermally fixed.

As described above, according to this embodiment,
Since a large amount of well-charged toner is supplied to the aperture of the aperture electrode, it is possible to provide a recording apparatus that can achieve high-contrast recording with a low control voltage and without fog.

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.

Further, in this embodiment, the aperture electrode is used as the toner flow control means.
It is easily understood that the mesh-shaped toner flow control means described in Japanese Patent No. 3221 may be used.

[0029]

As is apparent from the above description, according to the image recording apparatus of the present invention, a large amount of well-charged toner is supplied to the opening of the aperture electrode. It is possible to achieve high contrast recording without fog.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a configuration of an image recording apparatus.

FIG. 2 is a perspective view showing a configuration of an aperture electrode mounted on the image recording apparatus.

[Explanation of symbols]

 1 Aperture Electrode 4 Opening 5 Control Voltage Applying Circuit 6 Back Electrode 10 Toner Charging Supply Device 11 Toner Carrier Roller 12 First Supply Roller 13 Second Supply Roller 14 Toner

Claims (1)

[Claims] 1. A toner carrier for carrying charged toner, toner flow control means for controlling passage of the toner supplied by the toner carrier based on an image signal, and toner passed through the toner flow control means. An image recording apparatus having a back electrode for guiding a toner to an image forming support, characterized in that a plurality of toner layer forming means for respectively forming a toner carrying layer on the toner carrying body are provided. Image recording device.