JPH04159565A - Image recorder - Google Patents

Abstract

PURPOSE:To obtain a high-quality toner image by arranging a magnetic field generating means in a hollow turning sleeve which is constituted of a non- magnetic material and which is set on a recording electrode side with respect to a recording member on the downstream side of the recording electrode. CONSTITUTION:An endless belt 3 is supported so as to be able to travel by a driving roller 7 and a belt guide 15 which is constituted of the non-magnetic material on the downstream side in a recording direction of the recording electrode 5 adjacently to the recording electrode 5. The magnetic field generating means 11 is a permanent magnet fixed to a recorder main body inside the belt 3 and supplies a magnetic flux to a recording electrode needle 5c and a hopper 6. A toner carrying magnetic field generating means 17 is arranged inside the belt 3 on an upstream side in a belt traveling direction with respect to the roller 7 and supplies magnetic field to the belt 3. Thus, the high-quality toner image which has distinct image contour, high black density and no fogging is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses magnetic toner, for example, conductive magnetic toner (hereinafter abbreviated as toner), and forms a toner image by directly injecting charge into the toner. It relates to a recording device.

[Conventional technology]

Conventionally, a cylindrical recording member and a recording electrode consisting of a plurality of recording electrode needles are arranged on the member at a minute distance, and magnetic toner is supplied to an area (recording area) formed by the recording member and the tip of the recording electrode. 2. Description of the Related Art An image recording apparatus is known that forms a visible image of toner by applying a recording voltage to the recording electrode needle according to an image signal. Such an image recording apparatus is described in, for example, Japanese Patent Laid-Open No. 1-204079.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, a recording voltage is applied to the recording electrode in accordance with the rotation of the recording member to form a developed image with toner on the recording member. Due to this rotation, not only toner (image-forming toner) that has adhered to the recording member by electrostatic force due to the application of recording voltage from the recording electrode needle, but also toner that does not form an image (non-image toner) flows out. . In the conventional technology, in order to remove this non-image toner, a non-image toner removing means consisting of a sleeve and an alternating magnetic field is arranged on the downstream side in the recording direction with a distance from the recording electrode, and the non-image toner is removed from the static magnetic field acting on the recording electrode. The effect of the alternating magnetic field of the toner removing means was avoided.

In such a case, the charge moves from the charged image toner to the non-image toner in the spaced portion, and the non-image toner is charged and adheres to the recording member. As a result, fogging occurs and the outline of the image becomes unclear. Furthermore, when a force is applied to remove the non-image toner which is charged and has strong adhesion, a portion of the image toner is also removed, resulting in a decrease in black density.

However, in the prior art, the non-image toner removed from the recording member by the non-image toner removing means is conveyed by a magnetic roll. Then, it is supplied to the recording electrode again to form a recorded image again. In such a case, the magnetic roll transports the non-image toner from the non-image toner removing means located downstream in the recording direction with respect to the eight electrodes, so that the long side of the recording electrode, which has a substantially rectangular cross section, can be removed and the non-image toner can be transported upward in the recording direction. The toner conveying means needs to have a large diameter, which increases the volume of the toner conveying means, which hinders miniaturization of the device.

A first object of the present invention is to effectively remove non-image toner flowing out from a recording area, and to record an image that can produce a high-quality toner image with clear image outlines, high black density, and no fogging. The goal is to provide equipment.

A second object of the present invention is to convey the non-image toner removed from the recording member by a toner conveying means using an endless belt, thereby making it possible to reduce the volume of the toner conveying means while obtaining a sufficient conveying distance. An object of the present invention is to provide an image recording device.

[Effect]

The magnetic field generating means uses the conveying force of the recording member to overcome the gravitational field to the non-image toner flowing out from the minute gap at the tip of the recording electrode, and instantly transfers the non-image toner to the recording member at the tip of the recording electrode both spatially and temporally. Since the charge is removed from the charged image forming toner, there is no charge transfer from the charged image forming toner to the non-image toner.
A high-quality toner image with clear image outlines, high black density, and no fog can be obtained.

Furthermore, a compact image recording device can be obtained by sucking the non-image toner flowing out from the minute gap at the tip of the recording electrode to the outer periphery of the endless belt and collecting it in a hopper as the endless belt runs.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a recording electrode in which a plurality of electrode needles are arranged so as to intersect with the moving direction of a recording member, and a recording electrode that moves with a minute gap between the recording electrode and the recording member. a hopper for depositing magnetic toner on the upstream side of the recording electrode in the movement direction and supplying the toner to the minute gap by movement of the recording member; a driver that applies a corresponding voltage to charge a portion of the toner in contact with the recording member; and an endless belt provided in a space formed by the recording electrode and the recording member on the downstream side of the recording electrode in the moving direction. , a magnetic field generating means disposed within the endless belt that attracts the non-image toner immediately after passing through the minute gap to the outer periphery of the endless belt;
and means for running the endless belt.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a cross-sectional side view of the image recording apparatus of the present invention.

Conductive magnetic toner (hereinafter abbreviated as toner) 14 is deposited and stored in a hopper 6, the configuration of which will be described below, and the toner at the bottom is in contact with the recording member 1.

The recording electrode 5 includes a thin wire pattern 5b made of a non-magnetic conductor arranged on an electrode substrate 5a made of a non-magnetic insulator,
Recording electrode needles 5c made of a plurality of non-magnetic or magnetic conductors arranged in a row in an out-of-plane direction in the figure on the tip side of the electrode substrate 5a;
A quick-acting integrated circuit 5d that applies a recording voltage to each of the recording electrode needles 5c, a protective member 5J made of an insulating non-magnetic material that protects the integrated circuit, and a protective member 5J that is fixed to the surface of the electrode substrate 5a on the side opposite to the integrated circuit. The heat sink 5f is made of a non-magnetic material with good thermal conductivity.

The terminal 5g of the integrated circuit 5d is soldered 5e to the thin line pattern 5b.
The thin wire pattern 5b is bonded to the recording electrode lead 5c by a bonding wire 5h. Furthermore, the recording electrode 5 is inclined toward the upstream side with its tip as a starting point.

The tram-shaped recording member 1 has a base made of a nonmagnetic conductor 1a made of, for example, an aluminum alloy, and a surface made of an insulator 1b made of, for example, an anodic oxide film of aluminum or a coating film of a thermosetting resin. It is installed with a gap of 20 to 300 μm between the electrode needle 5c and the electrode needle 5c.

The recording member 1 is rotated in the direction of the arrow shown in the figure, which is perpendicular to the column direction of the recording electrode needles 5c, by a quick-acting mechanism (not shown).

The endless belt 3 is located downstream of the recording electrode 5 in the recording direction.
In addition, the arrow a shown in the figure is moved by a drive roller that is adjacent to the recording electrode 5, is movably supported by an instant motion roller 7 and a belt guide 15 made of a non-magnetic material, and is rotated by an instant motion mechanism (not shown). Drive in the direction of.

The magnetic field generating means 11 is a permanent magnet fixed to the recording apparatus main body within the endless belt 3, and is, for example, a ferrite magnet YBM- manufactured by Hitachi Metals, Ltd. with a saturation magnetic flux density of approximately 0.4 T (4,000 Gauss). 2BD, recording electrode needle 5
C and hopper 6.

Here, by forming the magnetic field generating means 11 in a shape along the endless belt 3, it is also possible to omit the belt guide 15.

The toner transport magnetic field generating means 17 is disposed within the endless belt 3 and on the upstream side in the belt running direction with respect to the drive roller 7, and supplies a magnetic field onto the endless belt 3.

Here, the magnetic field generating means 11 and the toner transporting magnetic field generating means 17
It is also possible to use a single permanent magnet.

The scraper 8 has its negative side in contact with the sleeve 3, and the other side is fixed to the top of the recording electrode 5 by means not shown.

On the outer periphery of the recording member 1, there are provided a transfer roller 4 that presses the recording paper 2 onto the recording member 1, a cleaning plate 9 made of a flexible member that contacts the recording member 1 on one side, and a support that supports the cleaning plate 9. 10 are provided.

A screw 12 is installed in the discharged toner receiver 13 and is rotated by a quick-acting mechanism (not shown).

The toner hopper 6 deposits the toner 14, and the recording member 1 is on the lower surface thereof, so that the toner conveying force generated by the rotation of the recording member 1 and the magnetic attraction generated by the magnetic field generating means 11 are connected to the recording electrode 5. The toner 14 is stably flowed out from the gap with the recording member 1 to the downstream side of the hopper 6.

At this time, the driving integrated circuit 5d applies a recording voltage according to the image signal to the plurality of recording electrode needles 5c, selectively charges the toner 14 existing in the gap, and charges the toner 14 injected with charge. Electrostatic attraction is generated in the toner, which adheres to the recording member 1 and becomes image forming toner 148.

When the non-image toner to which no charge is injected passes through the gap by the two forces mentioned above, the toner transport force and the magnetic attraction force,
The magnetic attraction force that overcomes the gravitational field from the magnetic field generating means 11 causes it to fly toward the magnetic field generating means 11 as shown by arrow C.

The flying non-image toner 14b is attracted to the endless heald 3 by the magnetism of the magnetic field generating means 11, is conveyed in the direction of arrow a by the running of the endless belt 30, is moved onto the scraper 8, and is collected in the hopper 6. be done. Here, the toner conveying magnetic field generating means 17 generates a magnetic field that attracts the non-image toner 14b onto the endless belt 3 on the upstream side of the immediate-acting roller 7 in the belt running direction, and causes the non-image toner 14b to resist gravity. transportable.

The charged toner 14a forming the image is transferred onto the recording paper 2 by the pressing force of the transfer roller 4 to form an image.

Here, non-transferred toner 14 remains on the recording member 1 without being transferred. c is removed from the recording member 1 by the cleaning plate 9, falls and accumulates in the waste toner receiver 13 due to gravity, and is further collected into a non-toner container (not shown) by rotation of the screw 12.

2 and 3 show the magnetic field generating means 11 of the embodiment shown in FIG.
This figure shows the calculation results of magnetic flux distribution and magnetic force distribution, respectively. The circles in the diagram are top and bottom.

The calculation points for each IIIIl are shown on the left and right,
The direction of the line segment extending from there represents the direction of magnetic flux and magnetic force, and the length of the line segment represents its size. Each time the diameter of the circle increases by one step, the size of each represents the direction of magnetic flux and magnetic force. It has doubled.

Here, the magnetic force is, when toner particles exist in space,
The force exerted by the magnetic field on the toner particles is expressed as gravitational acceleration IG. The toner used in the calculation has a magnetization amount of 50em
When the amount of toner magnetization is larger than this value, the magnetic force increases, and when it is smaller, the magnetic force decreases.

The magnetic field distribution and magnetic force distribution shown in FIGS. 2 and 3 bring the following advantages to the image recording apparatus of the present invention.

The toner 14 is generated in the hopper 6 by the magnetic field generating means 11. They are coupled in a chain in the direction of the magnetic flux shown in FIG. The toner chained together flows out from the tip of the recording electrode 5 due to the conveying force of the recording member 1, and even if some of the chained bonds are broken, the magnetic field means 11 is generated. Since the toner is attracted toward the recording electrode 5 by the magnetic force shown in FIG. 3, chain-like recombination of the toner is quickly performed.

Although the toner 14 is stored in an irregular amount in the toner hopper 6, the toner stably flows out from the tip of the recording electrode due to the above-described action.

Most of the non-image toner flowing out from the tip of the recording electrode 5 begins to fly to the endless belt 3 from directly below the recording electrode 5 due to the magnetic force shown in FIG. 3, and becomes stronger as the recording member 1 rotates. Completely removed by magnetic force.

According to this embodiment, since non-image toner is immediately removed, there is no charge transfer from the charged toner that forms one image, and the image has clear outlines, high black density, and no fogging, resulting in high-quality toner. You can get the image.

According to this embodiment, since a magnetic attraction force that overcomes gravitational acceleration is always applied to the tip of the recording electrode 5, the toner 14 does not accumulate on the downstream side of the tip of the recording electrode 5.
You can always record from a fixed position.

In addition, since non-image toner is removed by magnetic means at the tip of the recording electrode 5, the removal force can be set to be more uniform in the recording width direction than the removal force from a vacuum source, air source, etc. The removal means can also be a simple device.

Here, the angle of the magnetic flux 11a on the tip side of the recording electrode 5 shown in FIG. There is. To obtain a clear image, it is necessary to set the magnetic flux angle between ±45° with respect to the normal line of the recording member 1, and to obtain higher image quality, it is desirable to set the magnetic flux angle between ±15°.

Furthermore, the magnetic force 11b at the tip of the recording electrode 5 shown in FIG.
is approximately 13G, but when this magnetic force becomes excessive, the amount of non-image toner increases compared to the amount of image-forming charged toner, and the charge from the charged toner to the non-image toner directly under the electrode increases. The magnetic force 11b at the tip of the recording electrode 5 is preferably 50G or less.

On the other hand, in order to sufficiently remove non-image toner from the recording member and obtain a high-quality image without fogging, it is preferable that the magnetic force be as strong as possible. In this embodiment, the shortest distance between the recording member 1 and the magnetic field generation means 11 is made shorter than the shortest distance between the tip of the recording electrode 5 and the magnetic field generation means, thereby preventing an excessive increase in the magnetic force at the tip of the recording electrode 5. Also, the magnetic force on the recording member 1 is increased, and non-image toner can be sufficiently removed to obtain a high-quality toner image.

Further, according to this embodiment, since the recording electrode 5 is inclined so that the tip of the recording electrode 5 is located on the downstream side, the downstream space created by the recording electrode 5 and the cylindrical recording member 1 is Can be set large.

The space expanded downstream allows the first magnetic field generating means 11 built in the belt 3 to be placed close to the tip of the recording electrode 5, so even with a small magnetic field generating means, the recording electrode 5 can be The necessary magnetic force described above can be obtained at the tip.

Further, according to this embodiment, since the non-image toner is transported by the endless belt 3, even if the volume of the toner transport means is reduced, the non-image toner can be transported to the recording electrode 5 having a substantially rectangular cross section.
A sufficient conveyance distance can be obtained to enable recovery beyond the long side of the paper to the hopper 6 on the upstream side in the recording direction, making it possible to downsize the apparatus.

Furthermore, according to this embodiment, since the endless belt 3 is arranged along the recording direction side surface of the recording electrode 5 and the surface of the recording member 1, the magnetic field generating means 11 can be arranged closer to the tip of the recording electrode 5. It is possible to apply sufficient magnetic force even if the magnetic field generating means 11 is made small, or even by using a magnet such as a plastic magnet, which has a weak magnetic force but is inexpensive and easy to process. This makes it possible to reduce costs.

FIG. 4 shows a third embodiment of the present invention, which is different from the first embodiment shown in FIG. A stationary second magnetic field generating means is added close to the member 1 and having a plurality of magnetic poles aligned in the recording direction.

Further, in order to configure a belt running system along the second magnetic field generating means 16, a belt guide 15 and a toner transporting magnetic field generating means 17 are additionally arranged.

Here, the magnetic field generating means 11. second magnetic field generating means 16;
It is also possible to use one magnetic field generating means having a plurality of magnetic poles as the toner transporting magnetic field generating means 17.

This embodiment is particularly effective when the amount of magnetization of the toner 14 must be set low due to the thermal fixing performance of the toner 14 and the like. That is, the magnetic force of the magnetic field generating means 11 cannot be made larger than necessary due to the limitations of the running system of the endless belt 3, and the magnetic force of the magnetic field generating means 11 cannot be increased more than necessary due to the limitations of the running system of the endless belt 3.
1 cannot generate a sufficient magnetic attraction force, the magnetic field generating means 11 and the second magnetic field generating means 16 are inserted from above the recording member 1.
By working together, a higher quality toner image with no fogging can be obtained.

Since a plurality of second magnetic field generating means 16 are magnetized along the recording direction, the rotation of the recording member 1 changes the vector component of the magnetic force acting on the non-image toner on the recording member, and It is possible to generate minute vibrations in the toner, and the non-image toner firmly attached to the recording member 1 due to intermolecular force or the like can be effectively removed by the minute vibrations.

Furthermore, since the second magnetic field generating means 16 exerts an exciting action on the above-mentioned non-image toner in a wide area along the recording member 1, the second magnetic field generating means 16 exerts an exciting action on the above-mentioned non-image toner in a wide area along the recording member 1. This makes it possible to remove non-image toner that has firmly adhered to the toner, and it is possible to obtain a higher quality toner image without fogging with a simple configuration.

〔Effect of the invention〕

According to the present invention, since the magnetic field generating means is disposed in a rotatable hollow sleeve made of a non-magnetic material, which is installed on the recording electrode side with respect to the recording member on the downstream side of the recording electrode, high-quality toner images can be generated. Obtainable.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, and FIG. FIG. 3 is a magnetic flux distribution and magnetic force distribution diagram, respectively, of the embodiment shown in FIG. 1, and FIG. 4 is an explanatory diagram showing a second embodiment of the present invention. 1. Recording member, 2. Recording paper, 3. First sleeve, 4. Transfer roller, 5. Recording electrode, 6. Hopper,
11... Magnetic field generating means, 14... Conductive magnetic toner, cow Oj・- 160q■- 6 cow OCrGF-

Claims (1)

[Scope of Claims] 1. A recording electrode in which a plurality of recording electrode needles are arranged in a row, a rotating cylindrical or cylindrical recording member having a minute gap with the recording electrode, and A means for supplying conductive magnetic toner is provided on the upstream side in the moving direction of the recording member, and by applying a recording voltage to the plurality of recording electrode needles according to an image signal, the gap is filled by the movement of the recording member. In an image recording apparatus that selectively charges the conductive magnetic toner passing through a section and obtains a microscopic image of the charged toner, each of the recording electrode and the recording member is located downstream of the recording electrode in the recording direction. An endless belt provided so as to be able to run in close proximity to and spaced apart from the endless belt, a magnetic field generating means for generating a static magnetic field provided in a space within the endless belt, and a running means for running the endless belt. Image recording device. 2. In claim 1, the magnetic field generating means is a rod-shaped permanent magnet, and the magnetic field generating means is a rod-shaped permanent magnet, and has a magnetic field that is sufficient to attract non-image toner that has passed through a minute gap between the recording electrode and the recording member to the outer periphery of the endless belt. An image recording device that generates strong magnetic force. 3. In claim 1 or 2, the magnetic field generating means comprises:
generating a magnetic force against the toner that overcomes the gravitational field, adjusting the outflow of the toner from the minute gap to form a connected state of the toner moving from the tip of the recording electrode toward the recording member; An image recording device that generates a magnetic force around the outer circumference of an endless belt that attracts non-image toner that has passed through the minute gap. 4. In claim 1, disposed within the endless belt,
An image recording apparatus further comprising an unnecessary toner removing means that is located downstream of the magnetic field generating means in the recording direction and attracts non-image toner adhering to the recording member to the outer periphery of the endless belt. 5. The image recording apparatus according to claim 4, wherein the unnecessary toner removing means comprises a magnetic field generating means in which a plurality of magnetic poles are arranged in the recording direction facing the recording member.