JPS61246781A - Picture displaying device - Google Patents

Abstract

PURPOSE:To remove toner completely from the surface of an image carrier by expanding a cleaning area of an image carrier as compared with its developing area. CONSTITUTION:When a photosensitive body A towhich toner adheres is passed through a developing device 14, the toner on the surface of the photosensitive body A is scraped by a magnet brush 22 and adsorbed and recovered to the surface of a sleeve 15 by a magnet roller 16. At the time of cleaning, a gap between the photosensitive body A and the sleeve 15 is set up wider than that of development. At the time of cleaning, the bristles of a brush 22 are extented as compared with that of the development, sweeping the toner on the surface of the photosensitive body A precisely. With respect to the relation between the developing area and cleaning are of the photosensitive body A, the cleaning area S is set larger than the developing area P in the moving direction of the photosensitive body A. Consequently, the toner on the surface of the photosensitive body A can be completely removed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image display device that forms and displays an erasable toner image on an image carrier such as a photoreceptor belt or an insulated drum.

[Prior art]

As an image display device that displays toner images formed by electrophotography on the surface of a sheet-like photoreceptor belt, the photoreceptor belt is formed into an endless shape or an end shape, and the photoreceptor belt is placed around a plurality of rollers. It has been known for a long time that the device is suspended and moved.

An image display device using this type of photoreceptor belt can form a high-resolution image, and since the screen is completely stopped during display, the eyes will not get tired even if the image is read carefully for a long time. In this device, the toner developing device having a sleeve performs the developing process and the cleaning process, and when both image carriers move forward, the photoreceptor belt is developed, and when they move back, cleaning is performed. Sometimes, it is difficult to completely remove the toner on the photoreceptor belt, and there is a problem in that the toner remaining on the photoreceptor belt scatters and contaminates the apparatus. If the scattered toner adheres to optical components, it will cause image deterioration, and if it adheres to electrical components, it will cause malfunction. moreover,
Some of the scattered toner also scatters outside the image display device, contaminating the room.

[Purpose of the invention]

The present invention was developed in view of the above points, and its object is to completely remove toner on an image carrier.
An object of the present invention is to provide an image display device.

[Rounding method to solve the problem]

In order to solve these problems, the present invention provides an image display device that forms a toner image on an image carrier and displays this toner image on a display section. JAjl! is developed when the image carrier moves forward by a developing means that moves back and forth and has a sleeve. , perform a cleaning process during the return movement, and
It is characterized in that the J-ning area is configured to be larger than the developing area.

〔Example〕

The present invention will be described below based on embodiments shown in the drawings. Drawings M1 and 2 show the entire image display device,
FIG. 1 is a longitudinal sectional view, and FIG. 2 is an external perspective view.

In FIGS. 1 and 2, 1 is a vertical device exterior casing;
2 is a display window formed with a large opening in the front panel of the exterior casing 1;
numeral 4 is an operation panel located at the bottom of the front panel, and numeral 4 is a display window glass attached to the display window. 5, 6, and 7 are rollers for supporting sheet-like photoreceptors, which are disposed at the upper and lower parts of the exterior housing 1 so that their axes are parallel to the left-right direction of the exterior housing, and are individually rotatably supported by bearings. . The photoreceptor is a sheet-like photoreceptor supported by the rollers 5, 6 and 7. The photoreceptor is stretched between a rewind roller 5 and a drive roller 6, and reciprocates in the direction of the arrow. The rows 25 and 6 are connected to a motor (not shown).

This sheet-like photoreceptor A (hereinafter simply referred to as photoreceptor) has a base layer made of a transparent sheet such as polyethylene terephthalate, and a very thin layer of metal is deposited on the outer surface of the sheet to substantially maintain transparency. It is made of a flexible material that gives conductivity as it remains, and forms a photosensitive material layer (photoconductive layer) such as CdS or oPe (organic photoconductor) on the metal-deposited side. It is supported by the above-mentioned three support rollers 5 to 7 with the photosensitive material layer facing outside.

Reference numeral 8 denotes a laser beam scanning type image exposure device which is fixedly arranged in a space on the inner surface side of the photoconductor A, and includes a semiconductor laser oscillator 9, a polygon mirror scanner 10, an fθ lens (reflection lens) 11, It has a projecting mirror 12 and a transparent plate 13. The transparent plate 13 is a horizontally long transparent outer flat plate made of glass or plastic, etc., which is placed in pressure contact with the inner surface of the stretched photoreceptor portion between the rows 25 and 7 with an appropriate force.

In this image exposure device 8, a laser beam L is intermittently modulated in accordance with a time-series electrical pixel signal supplied from an output of an image reading device in an electronic computer, etc., from a semiconductor laser oscillator 9 in the front of the drawing to a back of the drawing It is fired toward the rotating polygon mirror scanner 10. The laser beam L incident on the scanner 10 is swung in the width direction of the photoreceptor, passes through the fθ lens 11, the reflecting mirror 12, and the transparent plate 13, and enters the inner surface of the photoreceptor A between the rollers 5 and 7. is scanned by a laser beam in its width direction.

As a result, an image is exposed by a laser beam from inside the photoreceptor, with this laser beam scanning as a main scan and the movement of the photoreceptor A as a sub-scan.

A toner developer 14 is disposed on the outer surface of the photoreceptor between the rollers 5 and 7, and serves as both a developing means and a cleaning means, and is arranged to extend in the width direction of the photoreceptor. The transparent plate 13 is disposed with its lower surface slightly protruding downward from the common tangent line below the rollers 5 and 7, so that it is pressed into contact with the inner surface of the photoreceptor A. The toner developing device 14 is provided with a hollow sleeve 15 that has a magnetic roller 16 inside and is immersed in the toner (developer) D in the developing device box.The magnetic roller 16 is used during image formation. That is, when the photoreceptor moves forward, it is rotated counterclockwise by a developing motor (not shown), so that the toner D moves clockwise on the surface of the sleeve 150 and is conveyed to the photoreceptor A for development.

Further, the magnetic roller 16 is rotated clockwise by the developing motor at a low speed during cleaning, that is, when the photosensitive material moves back, so that the toner D is rotated counterclockwise on the surface of the sleeve 15. Move and clean/g.

Toner D is a one-component developer made of a mixture of magnetite, resin, carbon, etc. ◎ Note that a two-component developer may be used as the developer 0 17 is a doctor blade, which is conveyed along the sleeve 150 surface. Adjust the layer thickness of toner D to be constant. A plunger 1B rotates the developing device 14 about a support shaft 19 to control the gap (mutual distance) between the photoreceptor and the sleeve 15.

A stopper 20 comes into contact with the bottom surface of the developer box and defines the lowering position of the sleeve 15.

FIG. 5 shows the state of the developing device during image formation (development). When developing, the plunger 18 is turned on, the sleeve 15 is lifted upward, and the sleeve 15 is in the developing position. placed. At this time, the gap between the photoreceptor A and the sleeve 15 is t, and the photoreceptor A moves at a constant speed in the direction of arrow F. Gap t between photoreceptor A and sleeve 15
is held constant by abutting against the transparent plate 13 known spacer rollers (not shown) provided at both ends of the sleeve 150. Since the gap t is narrower than the gap d between the doctor blade 17 and the sleeve 15, an appropriately large toner pool 21 is formed between the photosensitive material and the doctor blade 17 during development.

FIG. 4 shows the state of the developing device during cleaning to erase the toner image on the photoconductor A. When cleaning, the plunger 18 is turned off and the bottom of the developing device box contacts the stopper 20. stop, and the sleeve 15
It is placed in the position shown in the figure. At this time, the gap between the photoreceptor A and the sleeve 15 is T, and this gap T is larger than the gap t during development (T>1), but the magnetic brush 2 formed by the magnet 16 and the toner D
The tip of No. 2 must be in contact with the surface of photoreceptor A. That is, the gap is set to be larger than t and within a distance range where the magnetic force of the magnet roller 16 affects the surface of the photoreceptor A. Therefore, when the photoreceptor A with toner attached to its surface passes through the developing device, the toner on the photoreceptor A is scraped off by the magnetic brush, attracted to the surface of the magnetic roller 16 and the sleeve 15, and collected. During this cleaning, the gap T between the photoconductor and the sleeve 15 is larger than [1] during development, so the magnetic brush has a longer tip than during development. The toner can be wiped off easily, no toner reservoir is formed, and the toner is better prevented from scattering, solidifying, etc.

This image forming process is described in Japanese Unexamined Patent Publication No. 1986-
The present applicant disclosed it in No. 98746, so a detailed explanation will be omitted here.

Next, the image display operation performed by this device will be explained.

First, call up the image information by pressing the button on the operation panel 3,
After setting the necessary conditions such as designating the image display position and pressing the display start command manually, the drive CI -, F 6
The reciprocating motor rotates, and the drive roller 6 winds up the photoreceptor at a predetermined speed. Due to the rotational drive of the drive roller 6, the photoreceptor A moves in the direction of an arrow? direction and is supplied to the image forming section. After a predetermined period of time after the photoreceptor A starts moving, the plunger 18 is turned on and the sleeve 15 is lifted.
The sleeve 15 is placed in the developing position shown in FIG. 3, and preparations for forming one image are completed.

Next, while the photoreceptor is moving, laser beam scanning exposure of designated image information is started on the inner surface of the photoreceptor A between the rollers 5 and 7, and exposure scanning is performed.

At the same time as this exposure scanning, the magnetic roller 16 of the developing device 14, which is disposed outside the photoconductor A at a position facing the exposure scan, rotates in the direction of arrow G, and the toner moving on the surface of the sleeve 16 in the direction of arrow J is transferred to the photoconductor. As a result, toner images corresponding to the exposed images are successively formed on the outer surface of the photoreceptor A. Simultaneously with the completion of image formation, the plunger 18 is expanded and the sleeve 15 is separated from the surface of the photoreceptor A and returned to the cleaning position shown in FIG. 4. At this time, the power to the developing motor is turned off, but the magnet row 216 continues to rotate for a while due to inertia, so the toner on the surface of the sleeve 150 is transported and the toner reservoir 21 is cleared. Further, as the photoreceptor moves, the toner image formed on the photoreceptor moves from bottom to top toward the display window, and when it moves to a designated display position, the photoreceptor's movement line is stopped.

At a position corresponding to the display window 2, the toner image formed on the photoreceptor can be visually recognized through the display window glass.

Next, in response to the display end command, the reciprocating motor connected to the υ rewind roller 5 rotates, and the rewind roller 5 winds up the photoreceptor. The photoreceptor moves in the direction of the arrow R by the rotation of the rewind roller 5, moves from top to bottom with respect to the display window, and is rewound to the rewind roller 5 at the desired position for backward movement. The motor stops rotating. When rewinding the photoreceptor, as shown in FIG. 4, the ears of the magnetic brush 22 between the photoreceptor and the sleeve are longer than when they are currently in use, and their tips contact the surface of the photoreceptor A evenly. To reliably clean toner on a photoreceptor. In this case, the development motor rotates in the opposite direction to that used during enlargement and development, and at a low speed, and this causes the magnet roller 16 to rotate in the direction of arrow R, moving the surface of the sleeve 16 in the direction of arrow R. The photoreceptor is cleaned by the toner moving in the direction, thereby preventing cleaning failures and also preventing scratches on the photoreceptor.

When the photoreceptor A is moving in the direction of arrow R in FIG.
After the leading edge of the toner image passes between the transparent plate 13 and the sleeve 160, the rotation is stopped. That is, the toner developer 1) 14 performs a cleaning process on an area on the photoreceptor that is larger in color than the area where the toner is not present when the photoreceptor moves back.

FIG. 5 shows the developing area and cleaning area of the photoreceptor. The cleaning area B is larger than the developing area (image forming area) P in the direction of movement of the photoreceptor. The above-mentioned toner can be completely removed. In the above embodiment, a sheet-like photoreceptor moves back and forth between the rewind roller 5 and the drive roller 6, but a flat photoreceptor or Using an endless photoreceptor,
The present invention can also be applied to a device that reciprocates between an image forming section and a display section.

Further, in the above embodiment, the magnetic roller 16 rotates, but the present invention can also be applied to a mechanism in which the sleeve 15 rotates or both the sleeve 15 and the magnetic roller 16 rotate. . In this case, the rotation directions of the sleeve and the magnet roller are reversed when the image carrier moves forward and backward.

In addition, the position of the current device is fixed, the transparent plate 13 is movable,
The gap between one image carrier and the sleeve may be changed by moving the image carrier toward and away from the display device.

Further, in the above embodiments, a photoreceptor is used as an example of the image carrier, but it may also be a belt or a drum having an insulating layer for forming a latent image using an ion modulation method or a needle electrode.

〔Effect of the invention〕

As described above, the present invention uses a developing means having a sleeve that serves as both a developing means and a cleaning means, and when the developing process is performed during the forward movement of the image bearing member and the cleaning process is performed during the backward movement, the image bearing member can be cleaned. Since the cleaning area is larger than the developing area, the toner on the image carrier can be completely removed, and as a result, toner can be prevented from scattering from the surface of the image carrier.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an image display device showing an embodiment of the present invention, Fig. 2 is a perspective view of the same external appearance, Fig. 3 is a cross-sectional view of the present device when the image is formed, and Fig. 4 is a clear view. - A sectional view of the developing device in Jung's condition, and FIG. 5 is a diagram illustrating the developing area and the cleaning area. 2...Display window 14...Developer 15...Sleeve 1-6...Magnetic roller A...Photoconductor D...Toner

Claims (1)

[Claims] In an image display device that forms a toner image on an image bearing member and displays this toner image on a display unit, the image bearing member is moved back and forth between the image forming unit and the display unit, and the image bearing member is moved by a developing means having a sleeve. An image display device characterized in that a developing process is performed during forward movement of the image carrier, a cleaning process is performed during backward movement, and the cleaning area on the image carrier is made larger than the developing area.