JPH01161390A - Image display device - Google Patents

Abstract

PURPOSE:To automatically clean an image carrier simply by turning on a power source switch by controlling such that an image display part for the image carrier positioned in a display part passes by a cleaning means when the power source switch is turned on. CONSTITUTION:The title device is provided with image forming means 6, 8 and 9 forming erasable toner images on the image carrier 2, the display part 16 visually displaying the toner images formed on the image carrier 2 through the image forming means 6, 8 and 9, the cleaning means 4 erasing the displayed toner images formed on the image carrier 2, and a control means 29. In this device, when the power source switch 27 is turned on, an image carrier driving means is driven and controlled so that the image display part for the image carrier 2 positioned in the display part 16 passes by at least the cleaning means 4. Simultaneously the driving of the image forming means 6, 8 and 9 is stopped in the middle of passing. Thus, even if toner images remain displayed before the power source switch is turned on, they can be erased automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image display device that forms and displays a toner image in an erasable manner on an image carrier such as an endlessly rotating image carrier belt.

[Prior Art] As a conventional image display device of this type, there is one shown in FIG. 4, for example. The conductive magnetic toner 7 is conveyed by a rotating magnet roller 20 onto a developing sleeve 19 formed in a fixed non-magnetic cylindrical shape that covers the outer periphery of the magnetic roller 20, and is made of a magnetic material in an axial direction. It passes over a large number of Ti scrapers 21 arranged along the same direction. On the other hand, inside the main body frame l, a conductive recording medium 17 formed in the shape of an endless belt having an insulating layer on its surface is supported at a constant tension by a recording medium holding roller 3, and the conductive layer of this conductive recording medium 17 and the recording A voltage is applied between the f' pole 21 and the toner 7 is transferred onto the recording medium 17 by an electric field to form an image. When the image display of the first page is completed, the recording medium 17 is rotated in the direction of the arrow, and an image is formed and displayed in the same manner to display the image of the second page. Accordingly, the toner image of the first page is scraped off into the developing device 6 by the cleaning blade 18 and erased. In addition, a transparent fi 16 for handwriting made of transparent plastic, glass, etc., which also serves as a protection plate, is attached to the display opening 1a formed on the front side of the main body frame l, so that images such as letters can be written by hand with a felt-tip pen or the like. It can be written and displayed.

[Problems to be Solved by the Invention] By the way, in such an image display device, when the use of the device is finished, the last displayed toner image is transferred to the recording medium 17 with the image forming signal etc. turned off. It is preferable to erase the toner image by rotating it once for the next person to use it, but turn off the power without erasing the last displayed toner image.
In some cases, the toner image remained displayed and was used by the next person.

Therefore, even if an attempt is made to display handwritten images such as characters using the transparent board 16 for handwriting, the old toner image that remains displayed without being erased becomes an obstacle, causing the problem that the handwritten display image is not clearly displayed. It was difficult to invite.

In addition, when the next ministry uses a display device that has been left displaying a toner image and is powered off to form a toner image, if the new toner image does not fill the entire display area,
As shown in FIG. 5, the old toner image 22 and the new toner image 23 may be displayed in a mixed manner, resulting in a problem that the displayed image becomes difficult to see.

It is an object of the present invention to automatically erase the old toner image on the display section when the device is started to be used, to immediately display a handwritten image without performing a separate operation to erase the old toner image, and to display the new toner image. It is an object of the present invention to provide an image display device that can prevent a mixture of old toner images and old toner images from being displayed.

Means for Solving Problem L] The gist for achieving the object of the present invention is to provide an image forming means for forming an erasable toner image on an image carrier conveyed by an image carrier driving means; , a display section for visually displaying the toner image formed on the image carrier through the image forming means, a cleaning means for erasing the toner image on the display section formed on the image carrier, and the image carrier. In the image display device, the image display device includes a body driving means and a control means for controlling the driving of the image forming means, and when the power switch is turned on, the display control means displays an image of the image carrier located on the display section. The image display device is characterized in that the image carrier driving means is controlled so that the image forming means passes through at least the cleaning means, and the driving of the image forming means is stopped during that time.

[Function] According to the present invention configured as described above, the image carrier is conveyed and driven when the power switch is turned on, and the image display portion of the image carrier at the display portion position passes through the cleaning means. Even if the toner image is still displayed on
This toner image can be automatically erased.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

FIG. 1 is a schematic diagram showing an embodiment of an image display device according to the present invention.

The image display device according to this embodiment includes a rotating polygon mirror 13 rotated by a scanner motor 12, which is a laser beam from a semiconductor laser 11 that is turned on and off according to an image signal.
The photoreceptor tram 8 uniformly charged by the corona charger 9 is exposed to the reflected light through the reflection mirror 10 to form a latent image, and the toner developer 6 applies toner to the latent image. The toner image on the photosensitive drum 8 is transferred to the recording medium 2 by applying a positive voltage opposite to that of the toner image to the transfer drum 15, which also serves as a support roller for the recording medium 2. to display the image. When the image display switch 26 is pressed to display the next image, the recording medium 2 is rotated and the previously displayed toner image is transferred to the rear side of the display area by the cleaner roller 4 and the cleaner blade 5 into the developing unit 6. It is scraped off and erased.

The recording medium 2 may be opaque, such as glass cloth coated with Teflon, or transparent, such as polyethylene film. If a transparent material is used, a sheet with a colored background may be used. It is desirable that the toner image be clearly displayed by attaching the toner image.

27 is a power switch, 28 is an automatic erase mode switch,
29 is based on input signals from each of the above switches, etc.
A recording medium drive motor (not shown) for driving the recording medium 2, a corona charger 9 for performing primary charging, an image forming racer unit including a semiconductor laser II, a scanner motor 12, etc., a developing bias for the developing device 6, This is a control circuit that controls the bias voltage of the transfer drum I5.

As shown in the timing chart of FIG. 2, when the power switch 27 is turned on with the automatic erase mode switch 28 turned on, this control circuit 29 turns on the recording medium drive motor for one second to drive the recording medium 2. At the same time as the toner image is rotated once, an automatic toner image erasing operation is performed in which each output of the image signal, developing bias, primary charging, and transfer voltage of the image forming laser unit is stopped.

That is, when the image display device is newly used, when the automatic erase mode switch 28 is turned on and the power switch 27 is turned on, the recording medium 2 rotates once without image formation, so that the usage of 1γj is reduced. Even if the person forgets to erase the toner image, the old toner image is erased by the cleaner roller 4 and the cleaner blade 5, and the image display device can be used with no toner image recorded on the recording medium 2. I yelled what I could do.

Therefore, the user only needs to check whether the automatic erasing mode switch 28 is turned on and turn on the power switch 27, without performing any special operation to erase the old toner image. Images such as handwritten characters can be written on the screen, and even if a toner image is displayed, it will not be mixed with the old toner image.

On the other hand, when the power switch 27 is turned on while the automatic erase mode switch 28 is turned off, the automatic toner image erase operation for L5 seconds is omitted and the operation starts from the wait operation for the 2 second wait period, which is the same as before. The old toner image remains displayed, and the image display switch 26
When the is turned on and an image writing signal for displaying a toner image is input, the recording medium drive motor is driven to rotate the recording medium 2 to form a toner image, and the recording medium 2 is rotated to form a toner image. Instructs to output the image signal and drive the scanner motor 12, and also instructs the output of the developing bias and secondary charging, and then forms a toner image for one image display area in 5 seconds to form a single image. The aperture Ia stops the operation and displays the formed toner image.
Display it in a static state inside.

In the above embodiment, a laser beam method is used as a unit for forming a toner image, but a multi-stylus method as shown in FIG. 4 may be used.

Further, although the automatic erase mode switch 28 is selectively turned on and off, no automatic erase mode switch is provided, and when the power switch 27 is turned on, the toner image automatic erase operation is always performed and the wait operation is started. , after that, the toner image forming operation may be performed.

FIG. 4 is a schematic perspective view showing another embodiment of the present invention.

In this embodiment, at the same time as forming a toner image for display,
In response to instructions from the control circuit 29, a belt-shaped cleaning test image 25 is formed outside the display area of the recording medium 2 along the conveyance direction, and the cleaning roller 4 and transfer drum 1 are
A cleaning degree detection sensor 24 made of, for example, a reflective photosensor is provided between the cleaning test image 25 and the cleaning test image 25 .

The control circuit 29 has a cleaning degree inspection section that presets the cleaning degree, and the cleaning roller detected by the cleaning degree detection sensor 24 while the power switch 27 is turned on and the above-described automatic toner image erasing operation is executed. Cleaning test image 2 cleaned by 4
The cleaning operation is continued by rotating the recording medium 2 until the cleaning degree of No. 5 exceeds the threshold value set in the cleaning degree inspection section, but the cleaning operation does not exceed the threshold value within the cleaning operation of the specified number of rotations set in advance. If this is not possible, it is determined that the cleaning is defective, the cleaning operation is stopped, and the above-described wait operation is performed to wait for an instruction to display the toner image. At that time, the cleaning test image 25 is
The fact that the cleaning state of the recording medium 2, the cleaning roller 4, and the cleaning blade is poor means that the cleaning of the toner image formed in the display area of the recording medium 2 is very likely to be defective. It is desirable to display a warning display or the like to notify the user of the deterioration in the performance of the product 5 and to encourage replacement.

Note that this kind of control for leaning may be activated not only when the above-mentioned power switch 27 is turned on, but also during normal toner image recording operation, and in this case, a regular leaning operation is performed. Display images can be improved.

[Effects of the Invention] As described above, according to the present invention, cleaning of the image carrier is automatically performed by simply turning on the power switch, so that the image carrier can be used directly as a handwriting display board. Also, it is possible to prevent an old toner image and a newly formed toner image from being displayed together.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a schematic cross-sectional view of one embodiment of an image display device according to the present invention, FIG. 2 is a diagram showing a timing chart of its control circuit, and FIG. 3 is a diagram showing another embodiment. FIG. 4 is a schematic sectional view of a conventional image display device, and FIG. 5 is a perspective view showing a state in which an old toner image and a new toner image are displayed together. l: Body frame 2: Recording medium 4: Cleaning roller 7: Toner 8: Photosensitive drum 11 and two semiconductor lasers 13: Polygon mirror 15: Transfer roller
! 6: Transparent board for handwriting 27: Power switch 28: Automatic erasing mode switch 29: Control circuit.

Claims (1)

[Claims] An image forming means for forming an erasable toner image on an image carrier conveyed by an image carrier driving means, and a display section for visually displaying the toner image formed on the image carrier through the image forming means. an image display device comprising: a cleaning means for erasing a displayed toner image formed on an image carrier; and a control means for controlling driving of the image carrier driving means and the image forming means; When the power switch is turned on, the control means drives and controls the image carrier driving means so that the image display section of the image carrier located in the display section passes through at least the cleaning means, and during that time, the image carrier drive means An image display device characterized in that driving of a forming means is stopped.