JPH0297987A - Image forming body cleaning method for image display device - Google Patents

Abstract

PURPOSE:To maintain an image forming body surface to be always satisfactory by making a condition in which an image is not displayed at the time of the rise of an image forming body to compose a display surface, etc., and removing the contamination of the image forming body surface. CONSTITUTION:The cleaning time of a sheet 1 with a low resistance which is the image forming body is provided to one of the time of non-display and the times of the rise and fall of a device. The cleaning is executed in a process to execute a uniform development over several times on the surface of the sheet 1 by a developer 3 beforehand and to execute the cleaning by a cleaning member 5. In order to prevent the surface of the sheet 1 from being displayed in the middle of cleaning, an opaque sheet 4b is positioned on a front surface. After the cleaning is completed, a transparent sheet 4a is positioned on the front surface again, and an ordinary display is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for cleaning an image forming body in an image display device that forms and erases images on the image forming body.

[Prior Art] Conventionally, there are various methods for image display devices, but among them, there is a method using a magnetic stylus development method in which a developer is attached to the surface of a carrier, which is an image forming member, to form an actual image. The system is characterized by the fact that it does not require power consumption to hold the displayed image, and because it has a simple configuration, it is expected to be used in a wide range of applications.

[Problems to be Solved by the Invention] As mentioned above, in the method of forming an actual image and displaying an image by attaching a developer to the surface of a carrier, dew condensation and long-term use may cause the carrier to deteriorate. When the surface of the body becomes dirty, the charging characteristics of the surface of the carrier are affected,
There is a problem in that phenomena such as ghosting or fogging tend to occur, and the quality of the displayed image is impaired.

The present invention attempts to solve these problems. That is, the present invention provides a method for cleaning an image forming body of an image display device, which makes it possible to uniformly charge the surface of the image forming body such as a carrier by removing contamination from the image forming body such as a carrier at an appropriate time. The purpose is to provide

[Means for Solving the Problem] In order to achieve the above object, the present invention forms and erases an image on the display surface of an image forming body constituting the display surface, and In an image display device that can be used repeatedly, when not displaying and when starting up the device,
A cleaning period is provided during at least one of the times when the apparatus is shut down, and the image forming body is moved to remove contamination on the surface of the image forming body.

Further, during the cleaning period, the cleaning is performed in a state where the image is not displayed to a third party.

[Function] According to the present invention, a cleaning period is set at at least one of the times of non-display, startup of the device, and shutdown of the device to prevent contamination of the surface of the image forming body. Since the toner is removed, the surface of the image forming body can be uniformly charged, and phenomena such as ghosts and fog do not appear. Further, by not displaying the surface of the image forming body during cleaning, there is no possibility that a third party will be misled into thinking that the image forming body is malfunctioning.

[Embodiment] FIG. 1 is a perspective view showing an image display device implementing a first embodiment of the present invention, and FIG. 2 is a sectional side view showing the device in FIG. 1 in a normal usage state. FIG. 3 is a cross-sectional side view showing a state in which the carrier of the apparatus shown in FIG. 1 is being cleaned.

1 to 3, 1 is a low-resistance sheet that is an image forming body, la and Ib are rollers for conveying the sheet, 2 is a developing electrode, 3 is a low-resistance developer, 4a is a transparent sheet, 4
b is an opaque sheet, and 5 is a cleaning member.

That is, due to the action of the developing electrode 2 on the sheet 1,
The developer 3 is applied by electrical action to form a real image and display the image.

This is to apply a bias voltage between the developing electrode 2 and the sheet 1 via the developer 3, thereby retaining the injected charge onto the sheet 1, and retaining the developer 3 by electrical attraction. This method is an application of a developing method called a magnetic stylus.

After the sheet 1 is conveyed by the sheet conveyance rollers la and lb for one rotation, the developer 3 adhering to the sheet 1 is detached by the action of the cleaning member 5 and conveyed to the developing electrode 2 again. and used for development.

As the cleaning member 5, a static eliminating brush, a magnet, a blade, etc. are used.

The timing for cleaning the image forming body according to the present invention is at least one of the times when the image forming body is not displayed, when the device is started up, and when the device is shut down. A cleaning method in which the surface of the sheet 1, which is a forming body, is cleaned by setting a period of time for cleaning, is to
This is done by performing a developing or cleaning process on the surface of the sheet 1 several times. This cleaning will
Contamination on the surface of the sheet 1 is removed, and the charging property of the surface becomes uniform.

Here, displaying the surface of the sheet 1 in the cleaning state may cause a third party to misunderstand that it is malfunctioning.
Since this is not preferable, as shown in FIG.
is placed in front so that it acts as a shutter so that the surface of the sheet l is not displayed to third parties.

That is, in the state shown in FIG. 2, the display surface of the sheet 1 is displayed to a third party through the transparent sheet 4a on the front side, but when the device is started up,
As described above, cleaning is performed because dew condensation may occur on the sheet 1 due to changes in environmental temperature and humidity, affecting the adhesion of the developer 3 and causing image defects. .

Specifically, for example, using the operation settings as shown in FIG. 4, when the power switch is turned on, the display surface is covered with an opaque sheet 4.
Using b as a shutter, after the image being cleaned is no longer displayed, full-surface development or halftone-like development is performed over several to ten revolutions of the sheet 1. Note that the surface of the sheet 1 may be rubbed with the developer 3 on the developing device 4f12 so that the entire surface is not developed. After this operation is completed, normal display is performed again using the front surface as the transparent sheet 4a.

--like images are produced because dew condensation, dust, etc. on the surface of the sheet 1 are removed by rubbing with the developer 3, and because the charging characteristics of the surface are made uniform to prevent charging unevenness. It is. In this sense, if this operation is performed not only when the device is started up but also when it is shut down, the startup operation time can be shortened. It may also be performed when not displayed.

Note that when the power is turned off, the shutter may be opened to display the previous image, or may be closed to prevent deterioration of the sheet 1 and developer 3 due to sunlight or the like.

The motors may be driven individually for the two sheets 1, 4a, and 4b, or the drive may be switched by one motor using a clutch, etc., or other types of mechanical shutters or optical shutters may be used. May be used.

Transparent sheet 4a and opaque sheet 4 for shutter use
The conveyance direction of b may be either forward or reverse to that of the display sheet 1, or it may be at right angles. Also, the sheet 4
It is preferable that the color b be the same as or close to the color of the sheet 1 so as not to give a sense of discomfort, and it may be possible to display to a third party on an opaque surface that the sheet is being raised.

Note that the present invention can be implemented not only in the above-mentioned magnetic stylus development but also in an apparatus using other development methods.

FIG. 5 is a cross-sectional side view showing an image display device implementing a second embodiment of the present invention.

In other words, Fig. 5 is not the mechanical shutter mentioned above, but
This is based on an optical shutter 6 using liquid crystal.

As is well known, liquid crystal is sealed between transparent electrodes,
Depending on whether or not a voltage is applied, it can be used as a light shutter. By performing the opening and closing operations of the shutter in the sequence shown in FIG. 4, exactly the same effect as in the first embodiment described above can be obtained.

Of course, other optical shutters are also possible.

FIG. 6 is a cross-sectional side view of an image display device implementing a third embodiment of the present invention.

That is, FIG. 6 shows an image forming apparatus using an electric latent image. In this device, a corona produced by controlling the state of corona emission by converting an externally input image signal into on/off of the grid 8° voltage of the corona generator 8 is applied to the rollers 7a and 7b. An electrical latent image is formed by applying an electric charge to the surface of the dielectric layer 7 of the seat belt, which is composed of a dielectric layer 7 and a conductive layer 7°.

The formed latent image (indicated by 10 in the figure) is triboelectrically charged in advance in the gap between the metal cutting blade 9 (this may be brought into contact with an elastic blade, urethane rubber, etc.) and the developing sleeve 10 in the developing area. The image is developed by a magnetic brush contact method using a magnetic developer 11 (indicated by - in the figure). Thereafter, the charge on the displayed image is removed by a conductive brush 13, and then the developer is removed by a cleaning blade 14 to erase the image. The removed developer is again collected into the developing device 12 and reused. Note that the developer can be either one-component or two-component.

Here, during long-term use, residual charges may accumulate on the dielectric layer 7 on the surface due to contamination, etc., causing fogging, or the charges of the previous image may not be sufficiently removed, causing ghosts. .

To prevent this, it is possible to ground the conductive layer 7° or apply a bias, but such preventive measures are not sufficient.

Therefore, it is necessary to carry out the cleaning process at regular intervals, especially on a regular basis. The method is similar to that described above, in which a pattern latent image for cleaning is created using the corona generator 8, and then solid development is performed on the entire surface or halftone development is performed every few lines. This development and cleaning process is then repeated several times. At this time, it is undesirable for the solid image or halftone image to be seen by third parties, so the shutter 6, such as a liquid crystal, is kept closed so that the image surface is not displayed.

In this way, fogging and ghosting on the sheet surface are prevented.

[Effects of the Invention] As described above, according to the present invention, a cleaning period is set at at least one of the non-display time, the start-up time of the device, and the time of shutdown of the device, and the image Since contamination on the surface of the image forming body is removed, the surface condition of the image forming body can always be kept in good condition, preventing dew condensation, ghosting, fogging, etc., and enabling high-quality image display. . Furthermore, since the image is not displayed during the cleaning period, there is no leakage of secrets to third parties, and there is no risk of misunderstandings such as malfunctions.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG.
A perspective view of an image display device implementing an embodiment, FIG.
Figure 3 is a cross-sectional side view showing the apparatus shown in Figure 1 in a normal usage state; Figure 3 is a cross-sectional side view showing the image forming body of the apparatus shown in Figure 1 being cleaned; Figure 4 is an example of a time sequence. FIG. 5 is a sectional side view of an image display device implementing the second embodiment, and FIG. 6 is a sectional side view of an image display device implementing the third embodiment. 1... Sheet 2... Developing electrode 4a...
Transparent sheet 5... Cleaning member 7... 8 Electrical layer 9... Developing cut blade 11... Developer 3... Developer 4b... Opaque sheet 6... Shutter 8...・Corona generator 10...Developing sleeve 13...Conductive brush 14...Cleaning blade

Claims (1)

[Claims] 1. In an image display device in which an image is formed and erased on the display surface of an image forming body constituting the display surface, and in which the image forming body can be used repeatedly, when the image forming body is not displayed and when the device is started up. , an image forming body cleaning method which removes contamination on the surface of the image forming body while moving the image forming body by providing a cleaning period at least one time when the apparatus is shut down, the method comprising: A method for cleaning an image forming body of an image display device, characterized in that cleaning is performed in a state in which an image is not displayed to a third party during the cleaning period.