JPS6083063A - Picture forming device - Google Patents

Abstract

PURPOSE:To enable to resetting of a picture forming device at high accuracy without giving damage on the surface of a picture carrier by pulling out the picture forming device at a right angle to the direction of movement of a beltlike picture carrier. CONSTITUTION:A picture forming section that forms a visible picture on a belt 14 is positioned between rollers 12, 13, and a picture display section is positioned between rollers 13, 10, and a visible image formed on the belt 14 is displayed through a window hole 7. A laser beam scan type picture exposing device 15 provided inside of the belt 14 and a toner developing device 22 that makes an electrostatic latent image formed on the belt visible are provided in the picture forming section. Exposing and developing position is projecting outside of the position of common tangent connecting supporting rollers 12, 13. The developing unit 22 is pulled out in the direction of rotation of the belt 14 or mounted guiding space rollers 50 fitted rotatably on both ends of a developing roller 30 on the lower face of a supporting stands 24 provided on both ends of exposing rollers 20, 21 keeping a space (d). Thus, breakage of the belt 14 or falling down of toner from the surface of the developing roller can not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus having an endless belt-like image carrier stretched around an initial number of parallel support rollers in a tensioned state. A terminal device or 1 that reproduces and displays image information converted into an electrical signal, which is a calculation output or read output from an image reading device, etc., or image information stored as a soft copy on a magnetic tape, etc., as a visible image. The present invention relates to an image display device that is utilized as an image monitor device in a node device, an office automation device such as a copying machine, or other image-related equipment.

A conventional image forming apparatus of this type uses an endless belt-shaped photoreceptor as an image carrier, and is configured to form a toner image on the photoreceptor by electrostatic photography. In such an image forming apparatus, there is a means for forming an image on an image carrier, that is, in an image display apparatus using the silk/power method, a developing device is used to develop a latent image formed on a photoreceptor. It is often necessary to extract the imager from the imaging device for repair or maintenance.
In an electrostatographic image forming apparatus, the developing device is generally withdrawn temporarily from the surface of the image carrier and then pulled out in a direction perpendicular to the moving direction of the image carrier. However, in this method, the retracting mechanism for the developing device is complicated and takes up a large amount of space.In addition, in the case of a developing process in which exposure and development are performed at the same position with the image carrier in between, and at the same time. The setting position of the developing device has a great influence on the image quality, but with the pull-out method of the developing device described above, it is extremely difficult to reset the setting accurately.Especially when the above-mentioned image carrier is an endless long belt. In devices that use rollers, a number of rollers are required for tensioning the belt, but if the developing device is pulled out in the axial direction of the roller, a large hole will be created in the side plate that supports the roller so that it can rotate freely, which causes problems in the name. It was not possible to hold the rollers parallel to each other with high precision.As a result, the belt meandered and was likely to be damaged, so it was necessary to newly install meandering control means.On the other hand, there was a developing device drawer on the side plate. If the structure of the side plate is so strong that the parallelism between the rollers does not occur even if holes are provided, the apparatus will not only become larger and heavier, but also the belt replacement operation will become difficult.

The present invention has been made in view of the above points, and its purpose is to not only enable accurate resetting of all image carriers in the image forming means in an image forming apparatus using an endless belt-shaped image carrier; It is an object of the present invention to provide an image forming apparatus which can be easily operated without damaging the surface of a belt-shaped image carrier even when it is pulled out. ? Furthermore, another object of the present invention is to provide an image forming apparatus in which an image forming means can be pulled out without impairing the strength and precision of a side plate that pivotally supports a support roller that stretches a belt-like image carrier. Our goal is to provide the following.

An image forming apparatus according to the present invention includes an endless belt-shaped image carrier stretched around a plurality of parallel support rollers in a tensioned state, and an image forming section that forms a visible image on the image carrier. In the image display device equipped with the above-mentioned image display device, a part is provided for holding the image carrier in the image forming section outside a common external tangent line connecting a pair of support rollers located before and after the part, and an image is formed on the image carrier. An image forming means is disposed outside the image carrier in the image forming section, and the image forming means f is capable of being pulled out in a direction substantially parallel to the common external tangent line. It is.

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

First, the principle of image formation by electrostatic photography to which the present invention is applied will be explained with reference to FIGS. 1 and 2.

FIG. 1 shows the state of charge in the bright area. When the toner to which a voltage is applied comes into contact with the photoreceptor A, the photoconductive layer 2
An electric field is applied to the At this time, when the image light is irradiated, photocarriers e are generated in the photoconductive layer 2, and these photocarriers are guided near the surface of the photoconductive layer 2 by the action of an electric field. As a result, a strong electrostatic attraction force acts between the toner 5 and the photoconductive layer 2, and the toner 5 and the photoconductive layer 2 are immediately attracted to each other.
It is attached to the surface of the light body.

In the illustrated example, the photoconductive layer 2 is an N-type semiconductor, and a positive voltage is applied to the toner 5, so that electrons generated in the vicinity of the substrate in the photoconductive layer 2 due to irradiation with 18iiiI image light are It is well guided in the direction of the surface of the conductive layer 2.

As a result, a strong electrostatic attraction force acts between the toner 5 and the photoreceptor, and the toner 5 adheres to the photoreceptor. FIG. 2 shows the entire state of charge in the dark area. When an electric field is applied between the toner 5 and the conductive layer 1b of the substrate 1, electrostatic attraction acts between the two, but there is a photoconductive layer 2 between them, and they are separated by a distance. Therefore, its power is small. Therefore, the toner 5 is pulled away from the photoconductive layer 2, that is, the surface of the photoreceptor A, due to the magnetic force of the magnet 3 provided inside the fixed sleeve 4, the adhesion force between the toner 5 particles, and the like.

As described above, the toner 5 adheres to the bright areas of the photoreceptor A, and the toner 5 does not adhere to the dark areas, forming an image.

When changing the display content, the photoreceptor A having the toner image on its surface is used again as it is. In this case, since the toner image on the surface of the photoreceptor does not affect the next image formation in any way, there is no need to provide a separate cleaning means, and unnecessary toner images are removed during the next image formation due to the reason explained with reference to FIG. is erased.

Next, an embodiment in which the present invention is applied to an image display device that displays an image based on the principle of image formation by electrostatic photography described above will be described with reference to FIGS. 3 and 4.

FIG. 3 is an external view showing an embodiment of an image display device according to the present invention, and FIG. 4 is a sectional view thereof. In the figure, 6 is a vertical device exterior sieve, and 7 is a display image 111i with a large opening formed on the front plate surface of the exterior part! 8, the lower part of the front plate protrudes forward and the operation panel is placed on the upper surface; 9 is the display window glass pasted in the window hole 7; 10° 11, 12, 13 is a Four endless belt-type photoreceptor suspension support rollers, two each at the upper and lower parts, are arranged parallel to each other with their axes extending in the left and right directions of the exterior, and individually rotatably supported by bearings; This is an endless belt type photoreceptor (hereinafter abbreviated as belt) formed of the aforementioned photoreceptor that is suspended and supported by four rollers.

The belt 14 has, for example, a base layer of a transparent sheet such as a polyester sheet, a very thin layer of metal vapor-deposited on its outer surface to provide conductivity while substantially maintaining transparency, and CdS on the metal-deposited surface. It is entirely flexible and is formed with a photosensitive material layer (photoconductive layer) such as, for example, and is suspended and supported by the four support rollers mentioned above with the photosensitive material layer side completely outside.

Of the four supporting rollers, roller 10 is used as a driving roller to transmit the rotational force of motor M (FIG. 4), and at least one of the other three driven rollers, for example roller 11, is A belt tension roller is provided to apply tension to the suspended belt, and the above-mentioned suspended belt 14 is rotated by driving the drive roller 10 in the counterclockwise direction in FIG. 4 by the motor M. It is designed to rotate counterclockwise without waving, sagging, or slipping. With this rotation, the outer surface of the belt between rollers], 0, and 13 (the outer surface of the belt on the tension side) moves from the bottom to the top of the display image viewing window hole 7 on the front panel of the exterior part.

−d -, -=-L ~ -4 drops u　,　,　!　−’　.

As mentioned above, the bell) 14 has rollers 0,11°12.
An image forming section that is moved around belt 13 and forms a visible image on said belt 14 is located between rollers 2 and 13;
An image display section for displaying this image is located between the rollers 3 and 10, and the visible image formed on the belt 14 in the image forming section is displayed through the window hole 7 in the image display section.

In the illustrated embodiment, the image forming section includes a laser beam scanning image exposure device 1 provided inside the belt 14.
5 and a toner developing device 22 for developing an electrostatic latent image formed on the belt by this image exposure device.

The laser beam scanning type image destination device 15 is fixedly arranged inside the bell) 14, and includes a semiconductor laser oscillator 16, a polygon mirror scanner 7, an fθ lens 18, a mirror 8119, and two exposure rollers provided on the front side of the drawing. 20.2
1'li- has. These two exposure rollers 20.2
1 and 2 are arranged parallel to each other between support rollers 2 and 130 degrees to form a slit through which the laser beam passes.

This image exposure device 15 oscillates an intermittent laser beam L from a semiconductor laser oscillator 16 toward a polygon mirror scanner 17, which corresponds to time-series electric pixel signals output from an electronic computer, image reading device, etc., and enters the scanner. The laser beam L is swung in the belt width direction and is passed through the fθ lens 1.
The laser beam enters the inner surface of the belt portion between the rollers 12 and 13 through the path of the slit between the rollers 12 and 13, and the inner surface of the belt portion is scanned by the laser beam in the belt width direction. Then, this laser beam scanning is used as a main scanning, and the rotational movement of the belt 14 is used as a sub-scanning, so that image exposure of the belt 14 from the belt inner surface 1 is performed by the laser beam.

The toner developing device 22 is disposed close to the outer surface of the track of the exposed portion of the belt between the i-rollers 12 and 13, and the electrostatic latent image formed on the belt 14 by this toner developing device 22 is exposed at the same time as the above-mentioned exposure. The image is visualized through the development process. Thereafter, the bell 14 is moved by the driving roller 10 to a position facing the display window glass 9 and used for display.

According to one feature of the invention, the above-mentioned exposure roller 20,
Reference numeral 21 denotes a bell) 142, which is arranged so as to be held outside of a common external tangent line connecting the pair of support rollers 12 and 13 before and after the bell. In other words, the exposure rollers 20 and 21 are disposed with their lower surfaces protruding downward slightly from the common tangent υ of the lower sides of the openings 12 and 13, so that they are in suppressed contact with the inner surface of the belt, and are always in constant contact with the belt. The tension is applied to maintain the flatness of the photoreceptor belt in the photosensitive section, and as the belt moves, it rotates smoothly. Other functions of the exposure rollers 20 and 21 include waving, vertical movement, and size of the belt 14, which is a rotating body, caused by rotational movement, and the development brush of the developing device 22 (brush-like spikes of developer formed by a magnet). ) is prevented from vertical vibration of the belt 14 caused by contact with the belt 14, and the development position and the exposure position are maintained constant to improve the development power.

According to another feature of the present invention, the toner developer 22 is disposed outside the bell 14 in the image forming section and can be pulled out in a direction substantially parallel to the common external tangent line. It has become.

Next, the specific configuration of the exposure rollers 20, 21 and the developing device 22 will be described.

First, the specific mounting configuration of the exposure rollers 20 and 21 is explained in the fifth section.
This is shown in FIG. In the figure, both ends of each exposure roller are tapered and rotatably supported on a support base 24 via bearings 23 such as beer bearings. Support stand 2
4 extends leftward, and the lower surface has a flat portion 25 and a slanted portion 26ft that rises leftward. These supports 24
is fixed to the lower surface of the mounting member 27 made of sheet metal.

At the center of the mounting part 27 in the longitudinal direction is an exposure roller 20°2.
A long hole 28 is bored at a position corresponding to the slit formed by 1. The front and rear ends of the mounting member 27 are bent downward to increase the strength, while the left and right ends are bent upward and fixed to the main body side plate (not shown) using screw holes 29.

Here, the slits formed by the exposure rollers 20, 2ll,
Since an optical signal such as a laser beam is incident between the rollers, it is desirable that the surface of each roller be subjected to a surface treatment such as black painting or black plating.

To describe the configuration of the developing device 22, the developing device 22
are the developing roller 305 shown in FIG. 7 and FIG. A timing belt 37 that transmits the information via a drive pulley 35 to a pulley 36 that is pivotally connected to a magnet 33, a left side plate 38 and a right side plate 39 that integrally support each of the above members, etc. are housed in the developing tray 40 as one unit. This unit is rotatably supported by a fixed shaft 42 installed between support plates 4, 1, and 41 fixed at both ends of the developing tray 40, and side plates 3
A spring 43 provided between the rear end of 8 and 39 and the developing plate 40 normally causes the developing roller 30 to be attached to the belt 1 in the image forming section.
4, so as to stand still aligned with each other with a predetermined small gap between them.

The above is a general description of the developing device 22, but to further explain the configuration of the developing roller 30 in detail, the developing roller 30 consists of a cylindrical magnet 33 and a rotating shaft 4 passing through the center thereof.
4 and a sleeve 45 provided outside the magnet 33 in a non-contact manner, of which the magnet 33
The trap is provided in such a way that it is in a fixed and integral relationship with the rotating shaft 44, and in a rotatable relationship with the sleeve 45 via a beer bearing 46.

Furthermore, at one end of the rotating shaft 44 (the left end in FIG. 6),
The driven pulley 36 described above is fixedly installed.

Support shaft portions 47 and 48 are formed in the sleeve 45 from both ends toward the outside in the axial direction, and these support shaft portions 47 and 48 are fixed to the left side plate 38 and the right side plate 39. A spacer roller 50 is fitted to the outer end of the support shaft portion 47.48 via a bearing 49, and a plate grip 511C is fitted.
A stopper is applied to prevent twisting. Note that it is practically desirable that the entire unit of the developing device 22 be provided in a weight-balanced relationship such that a rotational force is generated in the counter-time IT direction in FIG. 4 with the fixed shaft 42 as the center.

With the above configuration, the developing device 22 is normally biased counterclockwise in FIG. The spacer rollers 50 provided at both ends come into contact with the flat part 25 of the support plate 24, thereby forming a gap d between the circumferential surface of the sleeve 45 and the belt 14, and the spacer rollers 5' having a diameter of 0.50. The belt 14 rotates between the openings 20 and 20 without contacting the exposure apertures 20 and 21. The basic configuration of the developing unit 220 is as described above, but this entire unit is connected to the common circumference of the support rollers 12 and 13. It can be taken out by sliding on a rail 52 provided on the main machine frame in a direction substantially parallel to the line, that is, in the direction of the arrow in FIG. A pin 53 fixed at the tip of the rail 52 is a positioning pin for the developing unit 22.

FIG. 8 shows another embodiment of an exposure unit composed of an exposure roller 20, 21, a mounting member 54, and the like.

At one time, a compression spring 55 is in contact with the lower surface of the mounting member, and always applies an upward force to the mounting member.

On the other hand, an eccentric cam 57 fixed to the rotating shaft 56 is in contact with the upper surface of the mounting member, and a lever 58 is provided at one end of the rotating shaft 56. Therefore, by rotating the lever 58, the position of the exposure roller 20.21 can be raised or lowered. Specifically, when an image is being formed on the belt 14, the exposure roller 20, 21 is at the lowest point, and when the developing device is pulled out, it is at the highest point.

FIG. 9 shows a needle-shaped stylus 59 placed two times in the axial direction on the surface of the developing sleeve 45 in the embodiments shown in FIGS. 6 and 7.
000 to 3000 pieces - arranged in a row, this stylus 5
An example is shown in which the toner 31 is completely deposited on the surface of the image supporting belt (having an insulating layer provided on the outside of the conductive layer) 60 by applying the image electric signal to each of the toners 90 to form an image. Although the latent image forming and developing methods are different from those of the previous embodiments, a developing device (in this example, a stylus 59 is also used for the 'mJ image bearing belt 60)
In this example, the gap between the tip of the stylus 59 and the belt 600 is usually about 30 μm to 500 μm.

The neck is the exposure roller 2 above the developing sleeve 45 in this example.
0 and 21 are shown in two parts.

The effects of the present invention can also be achieved by replacing these with a single roller and placing them directly above the stylus 59.

As is clear from the above description, in the developing Bi pull-out method by gluing the exposure roller section and the developing device unit shown in the illustrated embodiment of the present invention, the exposure and The developing position is located outside, and the spacer rollers 50, which are rotatably loosely fitted to both ends of the developing roller 30, are fully guided by the lower surface of the support base 24 provided at both ends of the exposure roller 20, 21. Since the developer unit 22 is pulled out or installed in the rotating direction of the belt 14 while maintaining the gap d, the belt 14 will not be damaged or toner will fall from the surface of the developer roller even if a special evacuation mechanism is not provided. There's nothing to do. moreover,
In order to improve the effects of the present invention, by pressing the exposure roller unit portion to retreat inside the belt, the developing unit 22 can be attached and detached while the gap between the belt 14 and the developing roller 30 is widened. At this time, a stopper is provided between the rear end of the side plates near the spring 43 and the developing plate to prevent the side plates 38 and 39 from rotating beyond a predetermined angle. It should be noted that the present invention is not limited to the above-mentioned embodiments, and it is also possible to attach and detach the developing unit from the display (jail) of the apparatus by removing the apparatus exterior casing 6.
Guide means for the spacer roller 50 may be provided on the camphor frame of the main body, or protrusions may be provided on the side plates 38 and 39, and the developing device may be attached and removed while being guided by the guide means provided on the support stand 24 or the main body. is also possible.

As explained above, the image forming apparatus according to the present invention includes an image forming section that forms a visible image on an endless belt-shaped image carrier, and an endless belt-shaped image carrier that supports the supporting rollers before and after the image-bearing member. The image forming means (developing unit), which is located outward from the common external tangent line connecting the belt and forms a visible image on the endless belt-like image carrier, can be pulled out in a direction parallel to the common external tangent line. Therefore, there is no risk of damaging the surface of the image carrier by pulling out the image forming means in a direction perpendicular to the moving direction of the belt-shaped image carrier, and it is also possible to reset the image forming means. This can be done with high precision, and by providing a large opening in the side plate that pivotally supports the support roller that supports the endless belt-like image carrier, it is possible to avoid adversely affecting the strength and accuracy of the image forming means.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing the principle of image formation by electrostatic photography to which the present invention can be applied, FIG. 3 is an external view showing an embodiment of the image forming apparatus according to the present invention, and FIG. The figure is a cross-sectional view, and FIG. 5 is a perspective view showing the mounting configuration of the exposure roller.
6 is a sectional view showing the developing device, FIG. 7 is a partially cutaway view of the developing device, and FIG. It is a sectional view showing a modified example of the device. 6... Apparatus exterior part 7... Window hole 8... Operation panel 9... Display window glass 10, 11, 1
2.13...Support roller 14...Endless belt-shaped photoreceptor 15...Laser beam scanning type image exposure device 20.2
1... Exposure roller 22... Toner developer

Claims (1)

[Claims] 1. An endless belt-shaped image carrier stretched around a plurality of parallel support rollers in a tensioned state, and an image forming section that forms a visible image on the image forming body. In an image forming apparatus, an image forming section is provided with a section for holding an image carrier in the image forming section outside a common external tangent line connecting a pair of support rollers located before and after the image forming section, and an image is entirely formed on the image carrier. An image forming device characterized in that a forming means is disposed outside the image carrier in the image forming section, and the image forming means can be pulled out in a direction substantially parallel to the common external tangent line. Apparatus N0 2: The image forming apparatus according to claim 1, wherein the above-mentioned Ij; holding part comprises a pair of JW optical rollers.