JPS5940666A - Image display device - Google Patents

Abstract

PURPOSE:To improve image visibility in fast mode, by laminating a high-sensitivity photoconductor layer on a transparent conductive base layer and laminating a light-color high-resistance material layer thereupon to a layer thickness less than that of the high-sensitivity photoconductor layer, and thus forming a photoreceptor. CONSTITUTION:Light from an exposure light part A(L) is incident to the high- sensitive photoconductor layer 45 through the transparent base layer 43 at an exposure position A on the rear surface of the photoreceptor. Couples of electrons and positive holes are generated where the photoconductor layer 45 is irradiated with the light, and the electrons (e) move by a bias E to the interface between the photoconductor layer 45C and high-resistance material layer 46 in the photoconductor layer 45 toward the surface of the photoreceptor. Then, charge inductive toner sticks Ta to the surface side of the high resistance material layer 46 of the photoreceptor from the side of a developing sleeve 16 by the Coulomb force between the charge (e) and the positive charge inductive toner. The high-resistance material layer 46 is thinner than the photoconductor layer 45, so the Coulomb force is strong and the toner sticks to the high-resistance material layer 46 stably.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an image that can be visually recognized, for example, electrical image information that is calculated or read out from an electronic computer or an image reading device, or image information that is stored as a soft copy on a magnetic tape or microfilm. The present invention relates to an image display device that reproduces and displays images as an image display device or is attached as an image monitor to image forming related equipment such as a copying machine and an office automation device.

More specifically, the method of displaying an image by forming one display image as a toner image on the surface of an image carrier using the body as a light guide 'l', particularly the applicant's earlier proposal (Japanese Patent Application No. 1986-1)
97410), in which a photoreceptor consisting of a transparent conductive basic layer and a single photoconductive It layer is used as an image carrier, and the photoreceptor is exposed to a light image as a substrate. An image method in which a toner image corresponding to the exposed image is formed on the surface of the photoconductive main layer by applying a conductive developer (toner) to the surface of the photoconductor layer at the photoconductive layer at the same time as the exposure is carried out from the layer side. Related to improvement of display devices.

FIG. 1 is a longitudinal sectional side view showing a very schematic structure of an example of an image display device of the above type. Reference numeral 1 denotes a vertical apparatus exterior box, and 2 represents a display image viewing window formed with a large opening on the front surface of the exterior box, and generally has a transparent plate 6 such as a glass plate stretched over it.

Reference numeral 4 denotes an endless belt-type photoreceptor (image carrier) stretched between a driving pulley (or roller) 5 and a driven pulley (same) 6, which are provided in parallel at the upper and lower parts of the outer box.

(hereinafter simply referred to as belt). For example, as shown in the second figure, the belt is formed by depositing a thin layer of metal on the outer surface of a transparent and strong base sheet material 41, such as a synthetic resin sheet or film, with high tensile properties to form a transparent inducing layer 42. A transparent conductive base layer 46 is formed, and a photoconductor layer 44 is laminated on the surface of the conductive layer 42 by a coating method, vapor deposition method, etc.
The outer peripheral surface of the belt 4 is the light guide layer surface. The belt 4 is rotationally driven in the direction of the arrow by the rotation of the drive pulley 5, and the tension side outer surface of the belt 4 moves past the display image viewing window 2 from the bottom to the top.

Reference numeral 10 denotes a light beam scanning type optical image exposure device disposed in the space between the tight side belt portion and the loose side belt portion of the rotary belt, which includes a semiconductor laser (or gas laser), a polygon mirror, an fθ lens, etc. Consisting of Then, a time-series electric digital pixel signal S is input from an image reading device, electronic computer, etc. (not shown), and a laser beam L modulated in accordance with the signal is oscillated in the direction of the driven pulley 6. The oscillated beam is deflected by the mirror 11 midway toward the back side part A of the driven pulley 6 of the tension side belt, passes through the slit 12a)Y of the slit plate 12, and directs the belt side part A in the belt width direction. IU: Runs fg light. The laser beam L (/J) scans in the belt width direction as a main scan, and the movement of the belt 4 as an abrasive scan, sequentially exposing the back surface of the belt 4 to one quadrant of light.

Reference numeral 16 denotes a developing device disposed at a position on the front side of the belt corresponding to the back side part A of the belt that receives the laser beam scanning exposure;
Reference numeral 4 denotes a lamp for irradiating the entire surface with light, which is disposed on the back side of the tension side belt and next to the exposure area A on the downstream side in the belt movement direction.

The illustrated developing device 16 includes a developer storage box 15.

A rotary developing sleeve 16 made of non-magnetic material such as stainless steel or aluminum, which is placed horizontally inside the box 15 and whose left side half circumferential surface is exposed outside the box, and a magnet row 217 which is inserted and built into the sleeve 16. , a developer applying blade 18 to the outer surface of the sleeve, and a developer (conductive magnetic toner) 1' contained in nine boxes 15. box 15
The conductive magnetic toner T inside the rotary developing sleeve 16 is attracted by the magnetic field of the magnet row 217 inside the sleeve, is held on the outer peripheral surface of the sleeve as a magnetic adsorption layer, rotates together with the sleeve, and is rotated by the blade 18 on the way. The toner layer thickness is regulated and layered, and the toner layered surface contacts and passes through the belt surface portion corresponding to the belt back surface light image exposure portion A by rotation of the sleeve.

A DC bias is applied between the conductive layer 42 on the belt 4 side and the developing sleeve 16, and E indicates the power source.

Image display is performed when light image exposure is started on the exposure area A on the back side of the belt 4 while the belt 4 and the developing device 16 are driven. The conductive toner on the side selectively adheres to form a toner image corresponding to the exposed image. The belt ff surface on which the toner image has been formed is rotated to a position within the range of the image viewing window 2 and once stopped. As a result, an image is displayed on the second window. After a predetermined period of time has elapsed, or by a belt re-rotation operation, the belt 4 is rotated again and the next display image is moved to the window 2, and the belt is temporarily stopped and the image is displayed. By repeating this process, images are displayed in sequence.

After the image display ends, the belt rotates and the developing device 1 is turned on again.
The displayed toner image on the belt surface that has reached the 6 portions is removed from the belt surface by the developing and cleaning action of the developing device and is collected into the developing device. On the belt surface from which the toner image has been removed, toner images corresponding to the light image exposure pattern at the exposure area A are successively formed, and the toner 11! The II image moves to the second part of the display window as the belt 4 rotates.

The entire surface light irradiation lamp 14 passes through the photoimage exposure area A and irradiates the back side of the belt, on which the toner image is formed on the front side, with light uniformly in the width direction, thereby exposing the inside Q area of the photoconductor 44 of the belt 4. This arrangement was made to uniformize the state of each part.

The toner image is formed on the surface of the belt without belt 1, and is performed simultaneously with light source exposure, and the principle thereof will be explained with reference to FIGS. 6 and 4. For convenience of explanation, the photoconductor layer 44 of the belt 4 is of N type, and the conductive layer 42 (=
It is assumed that a negative bias is applied to the developing sleeve 16 and a positive bias is applied to the developing sleeve 16.

At the light image exposure area A on the back side of the belt, the exposed area (A(L)
), FIG. 6) passes through the transparent base layer 46 and enters the photoconductor layer 44. Light guide 'I! 11-body/4-body-44 partial hole pairs are generated, and electrons e of them are attracted by the positive bias of the belt conductive layer member and the developing sleeve and move toward the surface side of the photoconductor layer 44. Along with this, the toner on the developing sleeve 16 side that comes into contact with and passes through the belt surface area corresponding to the light image exposure area A(L) on the back side of the belt becomes a charge opposite to the transferred electron e in the conductive toner in the surface layer part. A positive charge is induced. Then, due to the Coulomb force between the electron e and the positive charge induced toner, Ta is attached to the surface side between the positive charge induced toner. The positive charge of the attached toner Ta is then transferred to the electron e on the surface of the photoconductor layer 44 within a short time.
neutralizes and disappears.

On the other hand, in the exposed dark area (Ao, FIG. 4), the conductive layer 4 of the belt 4
2 and the bias between the developing sleeve 16.

Due to the capacitance between the conductive layer 42 and the conductive toner layer on the side of the developing sleeve 16, positive and negative charges are induced in the toner on the surface of the conductive layer and the four conductive toner layers, respectively. The Coulomb force acting during this period is weak, so that almost no toner adheres to the optical surface of the belt 4.

Therefore, the photoconductor layer 44 of the belt 4 can be exposed to light at the same time as the photoconductor layer 44 without any manual processing. The toner is selectively attached only to the surface portion of the photo4 electric layer corresponding to the bright exposed area of light exposure (Ta).
1. A toner image is formed.

Further, the toner image that has been rotated to the developing device 16 after being displayed is easily removed from the belt e side by being rubbed by the first layer of toner held on the side of the developing sleeve 16, and taken into the first layer of toner held on the sleeve. The toner particles are collected and used repeatedly to form toner images.

The above-described system in which a display image is formed as a toner image on an image-bearing surface using a photoconductor and displayed has better resolution than, for example, a CRT display device or a display device using liquid crystal.

Since it is a still image and does not flicker, and unlike a liquid crystal display, the angle dependence is small, so the image is easy to see and reduces eye strain.9 For those that require display images, the toner image formed on the belt surface is transferred to the copy paper surface. It has the advantage that hard copies can be easily obtained by adding a mechanism to do so.

Particularly, as in the above example, an apparatus which uses a bandless, simultaneous exposure toner image forming system and also functions both for development and cleaning has an extremely simple structure and is highly practical.

In addition to the laser beam scanning method described above, the optical image exposure device 10 also includes an LED array device, liquid crystal, PL
Various shutter arrays that selectively transmit ZT, white light, etc. can also be used. It may also be an exposure device that uses X-rays. In this case, the base layer 46 of the belt 40 does not have to be transparent to visible light, as long as it is transparent to X-rays.

By the way, in the above-mentioned image display device using the beltless, light image exposure simultaneous toner image forming method, in order to obtain a device as fast as possible, it is necessary to perform the light image exposure on the belt in a high-speed scanning manner and to apply a large amount of irradiation light. Shall we do it?

The light sensitivity of the light guide layer 44 on the belt 4 side is made sufficiently high.

However, in the former case, the optical image exposure device jt10 is complicated.
It will be large and expensive. In the latter case, for example, CdS
In the case of a photoconductor layer that utilizes the The color tone of CdS is dark 1, so the color tone of the photoconductor layer 440 using it also becomes dark, and the visibility of the display image formed on that surface deteriorates. Generally, photoconductive materials with high sensitivity have a dark color originally.
Therefore, even if a highly sensitive photoconductor is constructed using these photoconductive materials, the photoconductor of the photoconductor is dark in color, and the toner image formed has a dark background. Therefore, the visibility of the displayed image becomes poor.

The present invention uses the latter high-sensitivity photoreceptor to produce this type of photoreceptor.
The object of the present invention is to solve the above problem of poor image visibility when increasing the speed of a J-image display device.

That is, in the present invention, as the photoconductor 4, a highly sensitive photoconductor 1-45 is laminated on a transparent conductive substrate 1@46 as shown in FIG.
Furthermore, a light-colored high-resistance material layer 46 is formed thereon and has a layer thickness d2 smaller than that of the highly sensitive photoconductor layer.

The transparent conductive substrate f443 is made of, for example, a thin metal vapor deposit 1-42 formed on the surface of a transparent resin sheet 41, similar to the conventional one.

The highly sensitive photoconductor layer 45 is made of an organic semiconductor sensitized with a CdS dye doped with Cu or In, for example, Se.

It is a binder fractional binding layer or vapor deposited layer of a highly sensitive light guiding material such as 5e-Te. In the present invention, it does not matter how dark the color tone μ of this highly sensitive photoconductor layer is. Also, it may be either P type, N bipolar, or 1:'-N temporary type.

The light-colored high-resistance material layer 46 is, for example, 'J' i CJ.
2 layers.

ZnO layer, etc. These? Go has a pale white color. That is, the photoreceptor 4 used in the present invention (its surface f', i
A resistive material layer 4 is formed to cover the cylindrical light guide layer 45.
It exhibits a light color of 6.

Exposure of the photoreceptor 4 (d) is carried out from the transparent conductive base layer 43 side as in the conventional case, and the developer is applied to the surface of the high-resistance material layer 46 at the photoimage-exposed area at the same time as the exposure.

The principle of image formation in this case will be explained with reference to FIGS. 5 to 7.

1^j In this example, for convenience of explanation, the highly sensitive photoconductor M45 of the photoreceptor 4 is an N-type layer such as a resin binding layer of a photoconductive material such as CdS doped with Cu or In.

It is assumed that a negative bias is applied to the S upper layer 42 of the photoreceptor 4 and a positive bias is applied to the developing sleeve 16.

Exposure bright area (A CL) at exposed area A on the back side of the photoconductor
.

The light (FIG. 5) enters the highly sensitive photoconductor layer 45 through the transparent substrate layer 46. Electron-hole pairs are generated in the portion of the photoconductor layer where light is incident, and electrons e of these are moved by the bias E toward the surface of the photoconductor layer 45 in the photoconductor's body layer.
and the high-resistance material layer 46 (FIG. 5), or further to the vicinity of the surface of the high-resistance material layer 46 (FIG. 6). In response to this moving electron e, the light image exposure area A (g)
A positive charge is induced in the conductive toner in the surface layer of the toner on the developing sleeve 16 side that comes into contact with and passes through the belt surface area corresponding to the toner. Then, the positive charge induced toner is attached to the surface side of the high resistance material layer 46 of the photoreceptor 4 from the current sleeve 16 side due to the Coulomb force between the 70 charge e and the positive charge induced toner. This toner adhesion occurs not only when the toner e moves close to the surface of the high-resistance material layer 46 as in the example shown in FIG. Even if the movement only reaches the interface, the high-resistance material layer 46 is thinner than the photoconductor layer 45, so a strong Coulomb force acts between the electrons e and the positive charge-induced toner, and the high-resistance material of the toner Stable adhesion to the layer 46 side is achieved.

On the other hand, in the exposed dark area (A (g), FIG. 7), the conductive layer 42 of the photoreceptor 4 and the phenomenon sleeve 1 are connected as in the conventional case shown in FIG.
6 and the capacitance between the conductive layer 42 and the conductive toner layer on the side of the developer strip 16, the conductive layer 42
Although positive and negative charges are induced in the conductive toner layer and the surface toner layer, the Coulomb force acting between them is weak and therefore does not cause the toner to adhere to the photoreceptor 4 side.

Therefore, the toner on the developing sleeve 16 side is in the exposed bright area A (G).
Ta is selectively attached to the surface portion of the high-resistance material layer of the photoreceptor corresponding to toner 1. l! Li1#! is formed.

When the high-sensitivity photoconductor layer 45 of the photoreceptor is of P type, the direction of the bias E may be reversed from the illustrated example. Also, if the bias is bipolar, the polarity of the bias E should be set appropriately.

The resistance value of the high-resistance material layer 46 may be such that electrons e do not move and diffuse in the plane direction within the layer. Further, the thickness of the layer is preferably made as thin as possible as long as the color of the light guiding layer 45 does not change and the visibility of the image is not impaired. Furthermore, the layer is not limited to white, but may be colored with dyes, pigments, etc., for example, in pale pink, yellow, orange, etc., for the purpose of improving single-image visibility and preventing eye fatigue.

According to the present invention.

(1) Since the light guide layer 445 of the photoreceptor is a high-sensitivity layer, high-speed I/) III image display can be performed even if the light image exposure variation is relatively small; in this case, the image is displayed on the light guide layer 445 Since it is formed on the 46th surface of the light-colored high-resistance material layer formed over the high-sensitivity photoconductor J@45, the problem of poor image visibility due to the dark color of the high-sensitivity photoconductor J@45 is solved, and a bright image display is achieved. can be done.

(2) Since the high-sensitivity photoconductor layer 45 is covered and protected by the high-resistance material layer 46, the photoreceptor 4 can be used for a long time.

(6) The resistant material layer 46 is a thinner layer than the photoconductor layer 45,
Also, since it has a suitably high resistance, a sharp toner image is formed on that surface.

(4) During repeated image formation, most of the electric charge that makes the conductive toner carried on the photoreceptor is absorbed by the circuit formed by the metal part, which contains the high-resistance material 'RiM' and the conductive toner. In repeated image formation, there is no problem in smoothly forming a new image. In addition, the above-mentioned charge annihilation and Terama can be further shortened by making the high-resistance material ;- even thinner. In addition, light 1#! Because it gives exposure to light, the toner image that was carried in the past (the light cannot be blocked by the image) Since the toner is removed by the agitation 16, no toner is consumed.

Example 1 A transparent conductive film (made on a transparent conductive film) was used as the transparent conductive base layer 46, and activated with Cu and sensitized with 1r1.
The mixture in a similar weight ratio was dispersed in MEK, applied with a doctor blade, dried at 70°C for 60 minutes, and the two surfaces were rubbed uniformly to form a high-sensitivity light guide body layer 45 (thickness 60 μm).
Then, on the surface thereof, a mixture of TiO2 powder and acrylic resin at a weight ratio of 6:1, dispersed in toluene, is applied using a doctor blade, and this is dried to form a high-resistance material layer 46. A belt-shaped burnable photoreceptor 4 was manufactured.

This photoreceptor 4 was used to construct an image display device as shown in the first figure.

Example 2 Copper phthalocyanine and acrylic resin were dispersed and coated in M E K at a weight ratio of 1:1 on the same transparent conductive film as in Example 1 to obtain a charge generation layer, and a charge transport layer was formed on top of that. as 1-phenyl-3(4-N.

N-diethylaminostyryl)-5-(4-N.

A photoconductive layer was obtained by applying a solution of N-diethylaminophenyl) pyrazoline and a phenoxy resin dissolved in THF (tetrahydrofuran), and a mixture of I''-ZnO powder and an acrylic resin was applied to this photosensitive layer. An image display device as shown in the first figure was constructed using the body.

Both of the apparatuses of Embodiments 1 and 2 described above can perform high-speed image formation (20 crn/sec) using a conventional laser beam scanning exposure apparatus 10.

The image was sharp (= formed) on the surface of the almost white high-resistance material layer of IJI i Q 2 or ZnO and had good visibility.

Examples of other photoreceptor configurations: Se, 5e-Te, S provided by vapor deposition or coating on a transparent conductive film
i; f Rirui is a mixture of Cu-doped CdS powder wood and acrylic resin in a weight ratio of 100:7 and dispersed in toluene on a light guide layer made of sensitized CdS, organic semiconductor, etc. and dried. By forming the high-resistance material layer 46, a display photoreceptor that can be used in the present invention and has a substantially yellow surface is obtained.

Alternatively, if you want a suitable color tone as the base of the displayed image, use the above-mentioned 'I'i02. It is also possible to include a layer of a light-colored high-resistance material such as ZnO (= appropriate dye or pigment).

For example, by applying a mixture of the above-mentioned TiO2 powder and acrylic resin dispersed in toluene and dissolving Rose Bengal B in alcohol on the light guide layer, the surface becomes pale pink. A photoreceptor for display is obtained.

Similarly, by dissolving Indanthrene Brilliant Orange GR in alcohol, mixing it with a mixture of ZnO powder and acrylic resin and dispersing it in toluene, and coating it on the photoconductor layer, the surface A display photoreceptor having an orange tinge is obtained.

[Brief explanation of drawings]

Figure 1 is a very schematic configuration diagram of an example of an image display device;
The figure is an enlarged cross-sectional view of the developing device part, and FIGS. 6 and 4 are model diagrams showing the principle of image formation. FIG. 6 is a diagram of an exposed bright area, and FIG. 4 is a diagram of an exposed dark area. 5 to 7 are model diagrams showing the image forming principle of the image forming apparatus of the present invention, in which FIGS. 5 and 6 are diagrams of exposed light areas, and FIG. 7 is diagrams of exposed dark areas. 4 is a photoreceptor, 46 is a transparent conductive substrate, 44 and 45 are photoconductor layers, 46 is a high-resistance material (layer, and L is an exposure). 13vj: Developing device Fig. 5 Fig. 4 Fig. 7 Fig. 4 3

Claims (1)

[Claims] (1) A photoreceptor consisting of a laminated layer of a transparent conductive base layer and a photoconductor layer is used as an image carrier, and the photoreceptor is exposed to a light image from the base layer side, and at the same time as the exposure is performed, the light image of the exposed area is exposed to light. In an image display device of a type in which a toner image corresponding to an exposed image is formed on the surface of a photoconductor layer by applying a conductive developer to the surface of the conductor layer. As a photoreceptor, a transparent conductive base layer (=high-sensitivity photoconductor layer) is laminated, and a light-colored high-resistance material layer is further laminated on top of the layer with a layer thickness smaller than that of the high-sensitivity photoconductor layer. An image 1# display device characterized in that: