JPS61210382A - Image display device - Google Patents

Abstract

PURPOSE:To improve the maintainability by incorporating a belt-shaped image carrier a roll supporting this carrier, and an image forming means in a casing having a transparent part for an image display part and making the casing attachable to and detachable from a device body. CONSTITUTION:A belt-shaped photosensitive body 4 is moved back and forth by forward and reverse rotation, and rolls 5-7, the belt-shaped photosensitive body 4, and a developing device 13 are built in a casing 17 as one body to constitute a unit 20. The part, which corresponds to a display aperture 2 of a device body 1, of the casing 17 consists of a transparent material 18, and the part corresponding to the main scan position of a laser beam L consists of a transparent material 19. The unit 20 is guided freely slidably by guide rails 21-23 provided in the device body 1 and is attached to and detached from the device body 1.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention forms a toner image on a belt-like image bearing member by developing an electrostatic latent image corresponding to an information signal, and forms a toner image on the image bearing member. The present invention relates to improvements in image display devices used for display.

[Prior art]

An electrostatic image corresponding to an image signal is formed on a belt-like image carrier stretched between rollers, and this is developed with toner, and this toner image is displayed on a display section while being carried on the belt-like image carrier. An image display device for display has already been proposed (
For example, Japanese Patent Publication No. 58-98746). However, such a display device has a problem in maintainability of the device. For example, when re-stretching a long belt-like image carrier across multiple rollers for repair or replacement, the work must be done carefully to avoid scratching the surface of the belt-like image carrier. Maintenance and replacement work for the toner developing device is also troublesome in terms of alignment and prevention of toner scattering.

Therefore, it is necessary to rely on experienced service personnel, and the transparent plate of the window of the display section may become contaminated with toner or the like during work, and must be cleaned periodically.

[Purpose of the invention]

The present invention has been made in view of the above, and its purpose is to provide this type of image display device that is easy to maintain.

[Summary of the invention]

The present invention provides an image display device of the type described above, in which at least a belt-shaped image carrier, a pair of rollers on which it is stretched, and a toner developer are disposed in a casing having a transparent portion corresponding to at least a display portion, The device is characterized in that it is constructed as an integral unit that can be attached to and detached from the main body of the device together with the casing.

[Embodiments of the invention]

FIG. 1 is a longitudinal cross-sectional view of an image display device according to an embodiment of the present invention, and FIG. 2 is a perspective view of its appearance.

In FIGS. 1 and 2, 1 is a main body of the apparatus, and an opening 2 for display is provided on the front side of the main body. Further, an operating section 3 is arranged below it.

The belt-shaped photoreceptor 4 has one end fixed to a roller 5 and wound around it, and the other end fixed to a roller 7 via an idler roller 6. Therefore, the belt-shaped photoreceptor 4 is suspended and supported so that it can be reciprocated by rotating the rollers 5 and 7 in forward and reverse directions.

The belt-shaped photoreceptor 4 is formed by forming a photosensitive layer such as CdS on the surface of a transparent sheet such as a polyethylene terephthalate film, which is made conductive by providing a thin indium tin oxide film on the surface. The belt-shaped photoreceptor 4 is supported by each of the rollers with the photosensitive layer side facing outside.

A laser beam scanning system 8 is fixedly disposed inside the apparatus main body 1 and includes a semiconductor laser 9, a rotating polygon mirror schema 10, an f/θ lens 11, and a reflecting mirror 12. In this laser beam scanning system 8, an intermittent modulated laser beam L is emitted from a semiconductor laser 9 located on the front side of the drawing in response to time-series electric pixel signals supplied from an electronic computer output, an image reading device output, etc. It is fired toward the rotating polygon mirror schema 10 at the rear of the drawing. The laser beam L incident on the scanner 10 is swung in the width direction of the belt-like photoreceptor and forms an incident image on the inside of the belt-like photoreceptor 4 via the f/θ lens 11 and the reflecting mirror 12. is scanned by a laser beam in its width direction. Thereby, this laser beam scanning is used as a main scan, and the movement of the belt-like photoreceptor 4 is used as a sub-scan, so that an image is exposed by the laser beam from inside the belt-like photoreceptor. The belt-shaped photoreceptor is moved in synchronization with the scanning of the laser beam.

Opposed to the main scanning position of the laser beam, the photoreceptor 4
A developing device 13 is disposed outside the.

The developing unit 13 is provided with a slot 17 and a slot 15 having a magnet 14 therein, and the magnet 14 is rotated in the direction of the arrow by a drive motor (not shown) during image formation. A sleeve 15 is a developer 1 having conductivity and magnetism in the developer box.
I'm immersed in 6. Due to the rotation of the magnet 14, the developer 16 is carried over the three f15 and comes into contact with the surface of the photoreceptor 40,
It adheres to the surface of the photoreceptor 4 in response to image exposure by the laser beam and forms a visible image there.

Regarding this image forming process, Japanese Patent Application Laid-Open No. 58-9874
The method disclosed in No. 6 can be similarly applied, and the principle will be briefly explained here. Figures 5 and 6
The figure shows a conceptual diagram for explaining the principle, and FIG. 5 shows the state of charge in the bright part of the information light. When the voltage-applied toner comes into contact with the photoreceptor, an electric field is applied to the photoconductive layer 41 . At this time, when image light is irradiated, photocarriers e are generated in the photoconductive layer 41, and these photocarriers are guided near the surface of the photoconductive layer by the action of an electric field. As a result, a strong electrostatic attraction is exerted between the toner 44 and the photoconductive layer 410, and the toner is adhered to the photoconductive layer 41, that is, the surface of the photoreceptor. FIG. 6 shows the state of charge in the dark area. When an electric field is applied between the toner 44 and the conductive layer 42 of the photoreceptor 40, an electrostatic attraction is exerted between the two, but since there is a photoconductive layer 41 between them, the distance is Because they are far apart, the force is small. Therefore, sleeve 4
The toner is drawn to the surface of the photoconductive layer, that is, the photoreceptor, by the magnetic force of the magnet 46 provided inside the toner 5, the adhesion force between the toner particles, and the like.

As described above, toner adheres to the bright areas of the photoreceptor and toner does not adhere to the dark areas, forming an image.

When changing the displayed content, the photoreceptor 40 is moved again and the photoreceptor having the toner image on its surface is used again.

In this case, since the toner image on the surface of the photoreceptor does not have any adverse effect on the next formation of grains, there is no need to provide a separate cleaning means, and unnecessary cleaning means is not required during the next image formation for the reason explained with reference to FIG. The toner image is erased.

The rollers 5, 6, and 7, the belt-like photoreceptor 4, and the developing device 13 are integrally assembled in the casing 17, and constitute one unit 20 as a whole. This casing 17 has a disconnected circuit shape as a whole, and a portion thereof corresponding to the display opening 2 of the device main body 1 is made of a transparent material 18, and a portion corresponding to the main scanning position of the laser beam is also made of a transparent material 18. It is made of transparent material 19. Casing 17
A developing device 13 is fitted into the lower part of the protrusion.

FIG. 3 is a perspective view showing the unit 20 described above. The unit 20 is configured to be detachable from the apparatus main body 1. In other words, the Units) 20 is attached to and removed from the υ body 1 by being slidably guided by the guide rails 21°22.23iC provided on the body 1 and moved to the sides of the body 1, as shown in FIG. It is possible. When loading the device main body 1, the unit 20 is slid in the direction of arrow A in FIG. Then, the positioning pins 24 and 25 protruding from the unit 20 are fitted into positioning holes (not shown) provided in the main body 1 of the apparatus, thereby fixing the unit 20 at a predetermined position. Also, the positioning pin 24 of this unit 20.
The hole 17m of the casing 17 is located on the side where 25 is located.
, 17b to one end of rollers 5 and 7, respectively, 5 m
+7 a is exposed to the outside of the casing 17. A coupling pin 5b is attached to one end 5a of the roller 5.
A coupling pin 7b is provided at one end 7a of the roller rough. Note that 32 is an electrical connector.

Next, the driving means for moving the belt-shaped photoreceptor 4 will be explained with reference to FIG. On the apparatus main body 1 side, a coupling disk 26 and a pulley 27, each having a hole in which a coupling pin 5b is fitted at a position corresponding to the roller 5, and a pulley 27 are coaxially and rotatably supported by a bearing. Further, a coupling disk 28 having a hole in which a coupling pin 7b is fitted at a position corresponding to the roller 7 and a pulley 29 are coaxially fixed to the output shaft of a reduction gear GEX 31 of a motor 30. This motor 30 is supported by the main body 1 and is capable of forward and reverse rotation. Further, a drive transmission member such as a wire or a belt is disposed between the two rollers 27 and 29. In this state that the coupling portions of the rollers 5 and 7 are connected, the rollers 5 and 7 correspond to the forward and reverse rotation of the motor 30.
rotates forward and reverse synchronously. Therefore, the photoreceptor 4 reciprocates as shown by the arrow in FIG.

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

It is assumed that the unit 20 is loaded into the main body 1. First, after specifying the call-up of image information by operating the operation unit 3, when a key is pressed to command the start of display, the motor 30 rotates in the normal direction, and the belt-shaped photoreceptor 4 is fed out from the roller 5 at a predetermined speed. , is wound up by roller 7. Next, the image forming position on the inner surface of the belt-shaped photoreceptor 4 is irradiated with laser beam scanning exposure according to the specified information. Simultaneously with this exposure scanning, the toner 16 of the developing device 13 disposed outside the belt-shaped photoreceptor 4 facing the exposure scanning position of the beam acts on the photoreceptor 4, and the toner 16 is applied to the outer surface of the belt-shaped photoreceptor 4. Toner images corresponding to the exposure signal information are sequentially formed. As the photoreceptor 4 moves, the toner image formed on the photoreceptor 4 moves from bottom to top toward the display opening 2, and when it reaches a predetermined display position, the belt-shaped photoreceptor 4 stops moving. be done. In this way, the toner image formed on the photoreceptor 4 can be visually viewed through the transparent plate 18 at a position corresponding to the display opening 2.

Next, by manually inputting a display end command, the monitor 30 is reversed, the sheet-like photoreceptor 4 is rewound onto the roller 5, and moved from top to bottom with respect to the display opening 2, returning to the initial state. then stop. When displaying another image subsequently, the above operation is repeated.

As a means for controlling forward/reverse movement and stopping of the photoreceptor as described above, for example, a sensor such as a 7-oto encoder is disposed on the shaft of the roller 7, and each time the roller 7 rotates by a certain angle, By generating a pulse every time the photoreceptor 4 moves a certain length and counting these 9 pulses,
Knowing the amount of movement of the photoreceptor, it is possible to control the forward/reverse movement and stopping of the photoreceptor based on this information.

In the above embodiments, a photosensitive belt-shaped image carrier (
We have described the case where this is applied to an image display device using an image forming method in which a scanning light beam is irradiated onto a belt-shaped photoreceptor to form a toner image on the image carrier. An image display device that uses a method (for example, the so-called magnetic stylus method) in which a voltage is applied to a multi-needle electrode close to a shaped image carrier in accordance with an image signal to give an electrostatic charge distribution corresponding to the image and toner is adhered accordingly. It is clear that the present invention is also applicable to

〔Effect of the invention〕

According to the present invention, the belt-like image carrier, the roller that supports it, and the image forming means are built into a casing having a transparent part for an image display section, and can be attached to and detached from the main body of the apparatus integrally with the casing. With this configuration, maintenance or replacement of the belt-like image carrier and the toner developing device becomes easy, and an image display device with excellent maintainability can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an image display device according to an embodiment of the present invention, FIG. 2 is an external perspective view thereof, and FIG. 3 is a perspective view of a detachable unit in the embodiment. FIG. 4 is a perspective view showing the main part of the driving means, FIG. 5 is a diagram illustrating the state of charges in bright areas in the image forming process, and FIG. 6 is a diagram illustrating the state of charges in dark areas.

Claims (1)

[Claims] a belt-like image carrier; a latent image forming means for forming an electrostatic image on the belt-like image carrier according to an image signal; a developing means for developing the electrostatic image as a toner image; An image comprising a display section for visually observing the toner image brought there by movement, and a pair of rollers for stretching a belt-shaped image carrier therebetween through the latent image forming means, the developing means and the display section. In the display device, at least the roller pair, the belt-like image carrier, and the developing means are housed in a casing having a transparent portion corresponding to at least the display portion,
An image display device characterized in that the casing forms an integral unit that can be attached to and detached from the device body.