JPS59111182A - Picture display device - Google Patents

Abstract

PURPOSE:To prevent deterioration in picture quality due to zigzagging by providing projecting elastic members on both sides of an endless belt type photosensitive body and widening the belt width. CONSTITUTION:Each projecting streak 19 is nearly trapezoid, the upper surface 19a and lower surface 19b are almost parallel, and the external surface 19c is perpendicular to the upper surface 19a; and the internal surface 19d is oblique and the lower surface 19b is narrower than the upper surface 19a. When the beltlike photosensitive body 9 bends around a supporting roller, slits 21, are provided at equal pitch to the lower surface 19b of the projecting streak 19 so that the projection streak 19 bends smoothly without any influence on the bending; and in regard to those slits 21, a gap is brought in contact with each other at the flat part between rollers, but separated at a supporting roll part to form V-shaped grooves, bending the belt smoothly.

Description

[Detailed Description of the Invention] The present invention is applicable to image information converted into an electrical signal that is output from a computer, image reading device, etc., or stored as a soft copy on a magnetic tape or the like. Related to image display devices (image display devices) used as terminal devices or league devices that reproduce and display image information as visible images, or image monitor devices in office automation devices such as copying machines, and other image-related equipment. .

More specifically, the present invention relates to a novel configuration of a belt-like photoreceptor of an image display device that uses a belt-like photoreceptor as an image display section.

2. Description of the Related Art Conventionally, CRT display devices and liquid crystal display devices have been put to practical use as devices for visually displaying image information converted into electrical signals.

Among these, CRT display devices are the most used and reliable devices, but due to their resolution, they cannot handle fine characters used in newspapers and magazines, especially characters with a large number of strokes such as kanji. The magnitude of his talent cannot be expressed.

Although the text is enlarged to make it easier to decipher, the number of characters that can be displayed on the screen decreases in inverse proportion to the enlargement rate, and the amount of information per screen is small. Furthermore, if the same image is displayed continuously for a long time, the screen will be burned in and the display performance will deteriorate. Furthermore, if the screen flickers, your eyes will get tired.

Next, liquid crystal display devices are display devices that have recently been put into practical use, but like CRT display devices, not only do they have insufficient resolution, but large screens are also expensive to manufacture.

Therefore, an image display device using electrophotography was proposed as a third image display device that does not have the drawbacks mentioned in 1-. This image display device consists of a transparent endless belt whose outer surface is coated with a photosensitive agent, stretched around a plurality of colas.
While rotating this belt, a latent image is formed using an exposure means such as a laser or an LED array provided inside the belt, and at the same time as the exposure, development is performed from the outside of the photoreceptor corresponding to the exposed area, and converted into an electrical signal. The generated image information is visualized and displayed. In other words, image information is reproduced and displayed as a toner image.
It has excellent resolution, images are easy to see, large screens can be manufactured at relatively low cost, and it is a highly reliable device.
In a device such as this, in which an endless belt is stretched around multiple rollers, uniform tension is applied to the center of the belt, but the tension is released at both ends of the belt, so it is difficult to actually The applied tension becomes weaker, and it is difficult to maintain flatness equivalent to that of the central portion. Therefore, in order to ensure the effective image area width, the width of the belt was made wider than necessary, taking into consideration the deflection of both ends. On the other hand, this had the side effect of making it more difficult to control the meandering of the belt. ?・When the belt is rotated for a long time, both sides are partially stretched and a phenomenon occurs in which the belt becomes wavy. When this occurs, it becomes difficult to maintain the flatness of the belt between the rollers, causing inconveniences such as latent image formation and developing characteristics to deteriorate, I/toner scattering, and the quality of displayed images to deteriorate. The life of the photoreceptor will also be significantly reduced.

The present invention provides an apparatus for displaying images using an electrophotographic method using an endless belt, in which the belt width indicated by E is made extra wide.
The accompanying meandering, deterioration of development characteristics and image quality,
The purpose is to eliminate shortcomings such as a shortened lifespan of the photoreceptor.In addition to preventing the release of tension by reinforcing both sides of the belt by adding elastic members, it also prevents belt waving by increasing the rigidity of both sides. An object of the present invention is to provide an endless belt with a novel configuration that can maintain the flatness of the belt between rollers that guide the belt by preventing the belt from being flat.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a perspective view of the external appearance of the image display device, and Fig. 2 is a partially sectional perspective view of the external appearance, in which 1 is an outer box, 2 is a display image viewing port with a wide opening in the front, and 3 is an IE. The r part of the surface protrudes forward and the operation panel is provided on the top surface. 4 is a display window glass pasted in the window hole 2. 5, 6, 7.8 are axes parallel to each other in the left and right direction of the outer box and individually Four endless belt type photoreceptor suspension support rollers are disposed so as to freely rotate on the rollers. Reference numeral 9 denotes an endless belt type photoreceptor suspended and supported by the rollers (hereinafter simply referred to as a belt).

Near both ends of the support rollers 5, 6, 7.8, there are sprocket wheels 10, 11, j2, 13 (coaxially with the rollers).
(Omitted on the rear end side), sprocket wheel 1
A chain 14 is suspended at 0, 11, 12, and 13. As shown in FIG. 3, a predetermined part of the link plate 14a that connects the pin 22 of the chain 14 is provided with a protrusion 15, and one of the connections between the protrusion 15 and the stay 16 is a pin 17. However, the access hole in the stay 16 is large, and the chain 14 has some degree of freedom in the lateral direction. On the other hand, an elastic member 18 such as a flat plate of rubber is fixed to the center of the stay 16 so as to wrap around the stay. Therefore, the center portion of the elastic member 18 is thickened by the thickness of the stay, and the left and right portions 18a and 18b are thin so as to exhibit sufficient elasticity. An endless belt type photoreceptor 9 of the present invention having reinforcing protrusions 19 at the ends is adhered to the upper surfaces of the elastic members 18a and 18b. The protrusions 19 are made of an elastic material and are provided evenly so as to reinforce both sides of the belt 9, as shown in FIG. The protrusions 19 can be provided on the belt 9 by forming them in one piece, by adhesively fixing them, or by wrapping them around the inside and outside of the side surface of the belt as shown in Fig. 5. be. Here, the cross-sectional shape of the protrusion 19 shown in FIGS. 3 and 4 is approximately trapezoidal, the upper surface 19a and the lower surface 19b are approximately parallel, the outer surface 19c is perpendicular to the -1-plane 19a, and the inner surface 19d is oblique. , the lower surface 19b is narrower than the upper surface 19a. Belt photoreceptor 9
bends around the support rollers 5, 6, 7.8, the protrusion 1
9 cannot be influenced by this bending and bends smoothly. Therefore, as shown in FIG.
are provided at equal pitches. The slit 21 is a flat part between the rollers, and the cut is in contact with the beam, but the supporting rollers 5 and 6
, When it comes to the 7th and 8th part, the cuts separate and become a V-shaped groove,
Smooth the bend in the belt. Link play) X 4
A rectangular link plate 14b with rounded corners is connected to the link plate 14b by a pin 22 next to the link plate 14b in the moving direction a, and a normal link plate 14c is connected to the link plate 14c next to the rectangular link plate 14b with rounded corners. One end 23 of the square link plate 14b is the link plate 14.
a and 14c, and there is a pin 2 at the lower end 24.
5, two rollers 26 are rotatably provided. Coro 2
The outer periphery of the link plate 6 protrudes from the lower end 24 of the link plate 14b.

Further, the lower portion of the outer periphery of the roller 26 protrudes beyond the bent lower surface of the protrusion 15 and the lower surface convex portion 18c of the elastic member 18. The belt 9 has, for example, a base layer of a transparent sheet such as a polyester sheet, a very thin layer of metal deposited on its outer surface to provide conductivity while substantially retaining transparency, and a layer of metal deposited on the metal-deposited surface. It is entirely flexible and is formed by forming a photosensitive material layer (photoconductive layer) such as CdS, and the four rollers 5, 6, 7.8 shown in -1- are placed with the photosensitive material layer side outside. is strongly supported.

1-4 Among the rollers 5, 6, and 7.8, roller 5 is used as a driving roller to which the rotational force of a motor M (FIG. 7) is transmitted. At least 1 of the other 3 wooden rollers
Wooden rollers act as tension rollers (not shown)
The belt 9 is suspended twice, and the drive roller 5 is rotated by the motor M in the counterclockwise direction in FIG. 2 while the belt 9 is under tension.
Rotates counterclockwise without sagging or slipping. With this rotation, the outer surface of the belt between the rollers 5 and 8 (the outer surface on the tension side of the belt) moves from below to pass through the display image viewing window 2 part of the front panel of the outer box.

27 is a laser beam scanning type image exposure device which is fixedly arranged in the inner space of the route 9.

Semiconductor laser oscillator 28. polygon mirror scanner 29
．． fO lens 309 reflecting mirror 31. 2 at the bottom of the device outer box
It consists of a horizontally long transparent plate 32 made of glass, plastic, etc., which is placed in pressure contact with the inner surface of the stretched belt part between the support rollers 7 and 8 with an appropriate force.

This image exposure device 27 receives time-series electrical pixel signals output from an electronic computer, image reading device, etc. 751. The intermittent laser beam L is oscillated from the semiconductor laser oscillator 28 toward the polygon mirror scanner 29. The laser beam incident on the scanner is swung in the belt width direction and passes through the rollers 7 and 8 along the path of fθ lens 30 → reflector 31 → transparent plate 32.
The laser beam is incident on the inner surface of the belt i section between the two, and the inner surface of the belt section is scanned in the belt width direction. Then, this laser beam scanning is used as a main scanning, and the rotational movement of the belt 9 is used as a sub-scanning, so that the image of the belt 9 is exposed by the laser beam from the inner surface of the belt.

33 is a toner developing device disposed on the outer surface of the belt portion between the rollers 7 and 8.

(-) A transparent plate 32 (Figs. 8 and 9) disposed on the inner side of the belt portion between the laser beam scanning exposure section and the roller 7 and 8 prevents waving of the belt 9, which is a photoreceptor, due to rotational movement. It prevents the lower E vibration of the belt 9 caused by the L downward movement and contact with the developing brush (brush-like spikes of developing material formed by a magnet) of the developing unit 33, and shifts the exposure position to -.
・Improve the resolution by keeping the image constant.

When the display start command is input by setting the necessary conditions such as calling up the image information and specifying the display position by operating the operation panel 3, the rotation of the motor M causes the belt 9, which is the photoreceptor, to rotate at a predetermined speed. movement begins. Further, the exposure device 27 starts scanning and exposing the belt 9 with the specified image information using a laser beam on the inner side surface of the belt between the roller roughs 8. A toner developing device 33 is disposed on the outer surface of the belt in the exposure section, and toner acts on the outer surface of the belt at the same time as exposure, so that toner images corresponding to the exposed images are sequentially formed on the outer surface of the belt 9.

Bell!・As the belt rotates, the toner images sequentially formed on the outer surface are rotated from bottom to top to the display image viewing window hole 2 part of the face plate of the outer box 011, and are moved to the specified window hole range position. When it moves, the rotation of -υ bevel 9 is stopped. As a result, an image is displayed in the window hole 2, and the image is visually recognized through the display window glass 4. Next, when the belt is rotated again by the belt m rotation operation, the next display image moves to the window hole range position and the next screen is displayed. The toner image on the outer surface of the belt after being displayed is transferred to the toner developer 3 as the belt rotates.
When the third copy is reached, it is removed by cleaning with a developing brush, and immediately after this cleaning, it is subjected to simultaneous exposure and development again to form a new toner image.

Here, the belt 9 and the developing roller 34 in the image forming section
As shown in FIG. 8, the relationship between the effective area N of the belt 9 (the inner distance N between the protrusions 19 at both ends) or the roller length Q of the developing roller 34 (Q < N ), the protrusion J9 extends from the end of the roller 34 to the side of the developing device 33. The length of the magnet housed in the developing roller 34 is m, which is approximately equal to the length of the magnetic toner 35 adsorbed on the roller surface. Side plate 3 of developing device 33
6 comes into contact with the transparent plate 32 to maintain a constant gap between the belt 9 and the roller 34. The developing device 33 and the transparent plate 32 are connected to the stay 1
When 6 passes, N1 is passed.

In FIG. 9, the gap between the transparent plate 32 and the developing roller 37 is maintained by a large-diameter spacer roller 38 provided at the end of the roller. The protrusion 19 on the side of the belt is the roller 37
The magnetic toner 35 enters the groove 39 between the spacer roller 38 and prevents the magnetic toner 35 from going around from the side surface of the belt 9 to the inside of the belt 9, and helps normal exposure.

Since the belt 9 extends from the ends of the rollers 34, 37, etc. to the sides of the developing device 33, the belt 9 connects to the rollers 3 through the protrusions 19.
4, 37, etc., meandering can be prevented and good image quality can be obtained.

As described above, the present invention uses a belt-shaped photoreceptor with reinforcing protrusions on both sides, so that the tension is uniform on the front surface of the photoreceptor, and the center side between the rollers that rotates the photoreceptor is Prevents waving of the photoreceptor both on the side and on the 1st floor.
did it. In addition, it was possible to prevent the toner from going around to the inside of the photoreceptor in the image forming section, thereby achieving good image formation.

Furthermore, since the developing rollers 34, 37, etc. serve as guides for the belt 9, meandering of the belt can be prevented and good image quality can be obtained.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of an embodiment of the present invention, FIG. 2 is a perspective sectional view of FIG. 1, FIG. 3 is a perspective view showing an endless belt type photoreceptor of an embodiment of the present invention, Figures 5 and 6 are respectively the - section of Figure 3, which is a perspective view of an embodiment of the endless belt type photoreceptor, Figure 7 is a side view showing the optical system, and Figures 8 and 9 are 3A and 3B are cross-sectional views each showing an example of a developing section. 14b...Link plate 15...Protrusion 16.
... Stay 26 ... Roller 34 ... Transparent plate 38
...Spacecoro. Patent applicant Canon Co., Ltd.

Claims (1)

[Claims] 1. In an image display device that forms an image on the belt surface by stretching and rotating a plurality of rollers provided inside an endless belt type photoreceptor, the endless belt type photoreceptor An image display device characterized in that elastic members of protrusions are provided on both sides of the image display device, and an image forming means is disposed between the elastic members.