JPH01193886A - Image forming device with means for removing foreign matter in developer - Google Patents

Abstract

PURPOSE:To remove foreign matters mixed in a developer by setting the diameter of perforations of a foreign matter removing member, which is provided crosswise in the carrying direction of the developer so that it is brought into contact with a developer carrier, to a value longer than the outside diameter of developer particles and shorter than the length between a recording electrode and a recording medium. CONSTITUTION:A foreign matter removing member 14 having transmission apertures is provided crosswise in the carrying direction of a developer 1 so that its one end is brought into contact with a developer carrier 3 while the developer 1 is carried on the surface of the developer carrier 3, and the diameter of perforations of the foreign matter removing member 14 having transmission apertures is made longer than the outside diameter of developer particles 1 and shorter than the length between a recording electrode 4 of the developer carrier 3 and a recording medium 5. Thus, iron powder and dust 15 of plastics or the like which are mixed in the developer 1 are removed and are prevented from disturbing an image, and the damage of a recording element due to the existence of iron powder on the electrode 4 is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention applies a voltage between the recording electrode of a developer carrier and a recording medium to attach magnetic developer to the recording medium, which is used for image processing in printers, display devices, etc. The present invention relates to a forming device.

[Conventional technology]

As such an image forming method, Japanese Patent Publication No. 51-4670
There is a method known from Publication No. 7, etc.

In this method, as illustrated in FIG. 8, a one-component conductive magnetic developer 1 is held and conveyed on a non-magnetic sleeve 3 by a magnetic roller 2, and passed over a recording electrode 4 made of a magnetic material. . The developer 1 is connected in a chain shape by the magnetic field of the magnet roller 2, and its tip is in contact with the recording medium 5. By applying a voltage between the conductive layer 7 of the recording medium 5 having the insulating layer 6 on its surface and the recording electrode 4, an electrostatic field is generated between the conductive layer 7 and the developer 1 in contact with the recording medium. Developer 1 is electrostatically deposited onto 5. By converting this voltage into a signal, developer 1 is applied onto the recording medium.
It forms an image based on

[Problems to be solved by the invention]

However, in the above conventional example, 20
It is assumed that foreign matter such as metal powder or plastic powder of ~30 μm or more or dust in the air mixed in during use is mixed into the developer and becomes trapped between the recording electrode 4 and the recording medium 5. If this foreign material is a non-conductive foreign material such as plastic powder, it will prevent the injection of charge into the chained developer 1, and no electrostatic field will be generated on the recording medium 5. The image does not adhere to the surface of the recording medium, and a white streak-like image disappears in the direction of movement of the recording medium.

Further, if conductive foreign matter such as iron powder is interposed between adjacent recording electrodes 4, leakage will occur and the recording element will be damaged. Furthermore, if foreign matter, including dust, gets caught between the recording electrode 4 and the recording medium 5, the supply of the developer 1 will be obstructed, resulting in a white streak-like image plate as described above.

[Means to solve the problem]

A developer carrier having a magnetic field generating means therein, a developer container containing a developer, a recording electrode disposed in a longitudinal direction on a surface of the developer carrier, and the recording electrode. In an image forming apparatus having a recording medium in close proximity to the developer carrier, one end of a foreign matter removing member having a transmission opening contacts the developer carrier while the developer is conveyed on the developer carrier surface. The diameter of the hole of the foreign matter removing member which is provided in the transverse direction with respect to the conveyance direction of the developer and has the transmission opening is larger than the outer diameter of the developer, and the recording electrode of the developer carrier; It shall be smaller than the distance between recording media. This makes it possible to remove dust such as iron powder and plastics mixed into the developer, preventing it from disturbing the image or damaging the recording element due to iron powder intervening on the electrode. be.

〔Example〕

1, 2 and 3 show embodiments of the present invention.
The figure shows a sectional view of the present invention, and FIG. 2 shows a configuration diagram of a display device using the present invention.

As an example of a magnetic body, there is a magnet roll 2 having 16 N and S poles alternately inside. A plurality of non-magnetic sleeves 3, which are arranged in the vicinity of the recording medium 5 and on the same plane in the longitudinal direction, are positioned and fixed, and the magnet roller 2 rotates clockwise in the figure. It is driven as follows. However, if necessary, the non-magnetic sleeve 3 may be driven to rotate, but the magnetic roller 2
and the rotation speed or direction must be different. The recording medium 5 is an endless sheet having a charge retention layer on the surface and is supported by recording medium support members 11a and 11b,
rotated clockwise. At this time, the magnetic developer 1 held around the non-magnetic sleeve 3 by the magnetic field of the magnetic roller 2 is transported in the opposite direction of rotation of the rotating magnet rotor 2, so that the recording sheet 5 and developer 1 are transported in the same direction. The recording electrodes 4 are individually controlled by the recording control unit 1.
3 is sent, and a voltage is applied between the recording electrode 4 and the recording medium 5.

As a result, the developer 1 is electrostatically attached to the recording medium 5, and a visible image is formed. After passing through the display section of the main body frame 12, this visible image is transferred to the cleaning member 8, the magnet 9, and the non-magnetic plate 9'.
The developing agent 1 and the recording medium 5 are transported to a cleaner section consisting of a conductive carbon brush 8' at the tip of the cleaning member 8 to eliminate static electricity from the developer 1 and the recording medium 5. At this time, the developer 1 rubbed by the conductive carbon brush 8 falls onto the non-magnetic sleeve 3, is conveyed over the non-magnetic sleeve 3 again, and is used repeatedly. The non-magnetic sleeve 3 and the developer 1 held on the surface of the non-magnetic sleeve 3 are housed in a developer container 10, and are free from metal powder, plastic powder, and the conductive carbon brush mixed in the developer 1. It has a transmission opening for removing foreign matter 15 such as hair 8'. As an example of a foreign matter removing member, a non-magnetic mesh 14 is placed downstream from the recording electrode 4 in the developer transport direction, with one end thereof being in contact with the non-magnetic sleeve 3 in the longitudinal direction, and the other end being in contact with the longitudinal direction of the developer container 10 side. It is brought into contact at a position lower than the contact position of the non-magnetic sleeve 3.

3A and 3B are diagrams showing the settings of the mesh 14, where 16 is an IC driver, 17 is a flexible sheet, and 18 is a developer carrier.

As shown in the figure, the developer 1 is transported in the direction of the arrow and the mesh 1
4 extends to both ends of the non-magnetic sleeve 3. The hole diameter of the mesh 14 is larger than the outer diameter of the developer 1 and is smaller than the distance between the recording electrode 4 and the recording medium 5.
Foreign matter 15 larger than the hole diameter of the mesh 14 that passes through the mesh 14 and mixes into the developer 1 is divided by the mesh 14 and removed. Among the foreign substances 15 removed, non-magnetic foreign substances 15 such as plastic powder and hair from the conductive carbon brush 8' are removed.
For example, since there is no influence of the magnetic force of the magnet roller 2 and the mesh 14 is installed low on the developer container 10 side, the developer 1 is moved from the conveyance path of the developer 1 to the developer container lo by the action of gravity.
The foreign matter 15 is separated from the developer 1 by moving to the side.

By installing the mesh 14 shown above in the developer conveyance path on the non-magnetic sleeve 3, foreign matter 15 mixed in the developer 1 can be removed, and the drive IC driver can be This is to prevent damage.

In addition to the sleeve, the developer carrier may be a belt-like rotating body, a winding belt with ends, or a sheet. Although the above-mentioned magnetic field generating means is referred to as a magnet roller, it also includes bonded magnets, integrated mag rolls, and separate magnet aggregates. In addition to the mesh, the foreign matter removing member having a transmission opening may be a non-magnetic sheet or thin plate having a large number of holes or slits. Further, as a modified example of the developer, a two-component developer may be used.

[Second Embodiment] FIG. 4 shows a mesh of a second embodiment of the present invention. In this case, since the mesh 14 is in direct contact with the non-magnetic sleeve 3, the setting is easy.

[Third Embodiment] FIGS. 5, 6, and 7 show other embodiments of the mounting position of the mesh 14. In FIG. 5, the mesh 14 is placed upstream of the recording electrode 4 in the developer transport direction. installed. The foreign matter 15 thus removed is sent out along the mesh 14 to the outside of the developer 1 conveyance path, and is separated by falling due to the action of gravity.

Figure 6 shows a case where the mesh 14 is installed in accordance with the diameter of the foreign object to be removed from two or more locations, and by gradually decreasing the hole diameter in the developer conveying direction, the foreign object 15t is removed in stages from the largest one. This is effective in preventing clogging of the mesh 14 itself. In FIG. 7, both ends of the mesh 17 are attached to the developer container 10 side, and a part of the mesh 17 is attached to the surface of the non-magnetic sleeve 3. The narrow side with respect to the developer conveyance direction provides an escape route for the foreign matter 15. Since there is no foreign matter 15, the diameter of the hole on the upstream side of the recording electrode 4 in the figure is narrowed so that the foreign matter 15 can also pass through. According to this configuration, the nonmagnetic sleeve 3
Since the mesh 14 can be attached after the developer container 10 is installed, the setting is easy.

〔Effect of the invention〕

As explained above, by providing a foreign matter removal member having a transmission opening in the developer transport path on the developer carrier, 1. Foreign matter such as metal powder, plastic powder, fibers, etc. mixed into the developer can be removed. Second, since the recording medium will not be damaged, the durability of the device will be improved.

3. Leakage between electrodes can be prevented, and damage to the electrical components of the drive circuit can be prevented.

4. Since the recording medium is not rubbed by the above-mentioned foreign matter, recorded images are not disturbed.

There are other effects.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a device using the present invention, Fig. 2 is an overall view of a display device using the present invention, Fig. 3A is a mesh setting diagram of the device using the present invention, and Fig. 3B is a diagram showing the mesh setting of the device using the present invention. FIG. 4A is a cross-sectional view of the mesh setting of the apparatus using the second embodiment of the present invention. FIG. 4B is a cross-sectional view of the mesh setting of the apparatus using the second embodiment of the present invention. , Fig. 5 is a mesh setting diagram as a third embodiment of the present invention, Fig. 6 is a mesh setting diagram as a third embodiment of the present invention, and Fig. 7 is a mesh setting diagram as a third embodiment of the present invention. Figure 8 is a configuration diagram of a conventional example. 1...Magnetic developer 2...Magnetic roller 3...Non-magnetic sleeve 4...Recording electrode 5...Recording medium 14...Mesh 19...Mesh support member / Diagram ('''' --- 4/4

Claims (1)

[Scope of Claims] A developer carrier having a magnetic field generating means therein, a developer container containing a magnetic developer, and a developer container disposed on the surface of the developer carrier in a longitudinal direction. In an image forming apparatus having a recording electrode and a recording medium adjacent to the recording electrode, while the developer is conveyed on the developer carrier surface,
One end of a foreign matter removing member having a transmission opening is provided in a direction transverse to the developer conveying direction so as to be in contact with the developer carrier, and the diameter of the hole of the foreign matter removing member having this transmission opening is equal to the diameter of the hole of the foreign matter removing member having the transmission opening. An image forming apparatus having a developer foreign matter removing means, which is larger than the outer diameter of the developer and smaller than the distance between the recording electrode of the developer carrier and the recording medium.