JPS62217259A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent an image from being generated with defocusing, uneven density, fogging, etc., by arranging a guiding member on a position intersecting with the optical axis of an image exposing means and constituting a part of the guiding member which intersects with the optical axis of the image exposing means of a transparent member. CONSTITUTION:Transparent or translucent conductive layer 1b and photoconductive layer 1c are successively laminated on a transparent base 1a formed like an endless belt. A toner developing means 2 is arranged on the photoconductive layer 1c side of the endless belt-like photosensitive body 1 to supply toner 2a to the surface of the photosensitive body 1. The image exposing means 3 is arranged on the transparent base 1a side of the photosensitive body 1 to emit light corresponding to an image to be formed and project the transparent base 1a. The guiding member 4 is allowed to contact with the transparent base 1a side to guide the photosensitive body 1 so as to pass through a prescribed course and at least a part intersecting with the optical axis 3a of the means 3 is constituted of a transparent member 4a.

Description

[Detailed Description of the Invention] [Summary] In an image forming apparatus in which a toner developing means and an image exposing means are arranged opposite to each other via a transparent endless belt-like photoreceptor,
A transparent member for guiding the endless belt-like photoreceptor to pass through a predetermined path is provided between the endless belt-like photoreceptor and the image exposure means to prevent image blurring, density unevenness, fogging, etc. I did it like that.

[Industrial application field]

The present invention relates to an image forming apparatus that forms a toner image simultaneously with image exposure on a photoreceptor and performs display or transfer.

Current image recording apparatuses generally use an electrophotographic recording method, and image recording is performed through steps such as charging, exposure, development, transfer, and cleaning.

Since this recording method uses corona discharge to charge the battery, there are problems such as the generation of ozone and odor that are harmful to the human body, the generation of electrical noise due to the discharge, and a decrease in reliability due to dust and the like.

Therefore, a method has been proposed in which image recording and display are performed without using corona discharge.

[Conventional technology]

FIG. 9 is a diagram showing a schematic configuration of a conventional image forming apparatus.

Reference numeral 111 denotes an endless photoreceptor belt, which is composed of a transparent substrate, a transparent conductive layer, and a photoconductive layer in this order from the inside, and the transparent conductive layer is connected to ground.

113 is a magnetic brush developing machine, and a magnet roller 113b provided inside a sleeve 113a is rotatable.

A recording conductor 115 insulated with a polyimide film 114 is attached to the surface of the magnetic brush developing device 113. A voltage 116 having a polarity opposite to the carrier polarity of the photoconductive layer of the photoreceptor 111 is applied to the recording electrode 115, and a voltage 117 having a polarity opposite to the voltage 116 of the recording electrode 115 is applied to the sleeve 113a. As the developer, a -component or two-component toner 118 is used, and jM of the toner 118 is
The feeding is performed by a magnet roller 113b.

On the transparent substrate side (inside the belt) of the photoreceptor 111, an LED is installed.
An exposure means 119 including an array 119a and a SELFOC lens 119b is provided, and is arranged so that its optical axis intersects with the recording electrode 115.

In the apparatus configured as described above, the photoreceptor 111 and the toner 118 are moved in the direction of the arrow in the figure, and the image exposure means 1
By performing image exposure using 19, the photoreceptor 11
A toner image 120 is formed on 1.

Next, the image forming process of the conventional image forming apparatus will be explained using FIG. In FIG. 10, the same parts as in FIG. 9 are given the same numbers.

In the figure, when the photoconductive layer 111c is imagewise exposed in the A section, photocarriers are generated in the photoconductive layer 111c.

Among the photocarriers, the applied voltage 116 of the recording electrode 115
Carriers with opposite polarity are photoconductive F! It moves to the vicinity of the 1llc surface and becomes a latent image charge (positive in the figure). In this manner, the capacitance of the photoconductive layer 111c apparently increases in the exposed area, so the amount of attached toner increases, resulting in a toner image with a certain degree of contrast between the exposed area and the non-exposed area.

Next, in part B, there is a pool of developer that has been formed by moving in the direction of the arrow, and when passing through this pool, a reverse voltage 117 is applied to the sleeve 113a, so the excess in the non-exposed area The toner is collected by the developing device 113 by electrostatic force. At this time, a small amount of toner in the exposed area is also collected, but most of the toner remains on the photoreceptor 111 due to the electrostatic binding force of the latent image charge and the toner charge, and a toner image 120 is formed.

Thereafter, the toner image 120 is electrostatically transferred onto a recording paper 121 using a transfer roller 122, as shown in FIG. The transferred toner image 124 is fixed on the recording paper 121 by a fixing device 125, and a semi-permanent recorded image 126 is obtained.

On the other hand, residual toner 127 that has not been transferred is neutralized by a static eliminating light source 128 and does not lose its electrostatic binding force.
is collected and reused using magnetic force.

[Problem that the invention seeks to solve]

The image forming apparatus described above requires high positional accuracy in the exposure section and the development section. The positional accuracy of the exposure section varies depending on the aperture angle of the Selfoc lens array used and the resolution of the image, but for example, if the aperture angle of the Selfoc lens is set to 20
If the resolution of a 1° image is 240 (dots/inch), a positional accuracy of about ±0.1 mm is required. Also,
The distance between the developing section and the photoreceptor belt varies depending on the characteristics of the developer, but 0.3 to 0.5 inches is appropriate; below this distance, the photoreceptor belt will come into contact with the recording electrode and the photoreceptor will be damaged. If the distance exceeds this distance, no potential difference will be generated between the photoreceptor belt and the recording electrode and sleeve during image formation, resulting in an image with toner still attached to the non-exposed areas. Therefore, the positional accuracy of the developing section is also 0.1
mm order is required.

However, in the image forming apparatus described above, the photoreceptor belt is stretched by the tension of the support roller (there is no contact area) between the exposure section and the development section, so the exposure section and the photoreceptor belt are It is difficult to set the position of the developing section, and in some cases, the position of the photoconductor bell (・) may shift by more than 0.1 s* due to contact with toner even after setting, resulting in blurred images, uneven density, and fog. There was a problem that occurred.

Furthermore, in the conventional configuration, the exposure section is open on both sides of the photoreceptor belt, so minute dust and toner scattered from the development section can easily enter the exposure section and adhere to the LED array and SELFOC lens array. However, there were problems such as missing parts in the image.

Furthermore, the LED array used in the exposure section generates a considerable amount of heat, so if a cooling fan is installed in the conventional configuration, the belt may vibrate, resulting in image deterioration or 1. There was a problem in that the cooling air diffused inside the belt, reducing cooling efficiency.

For this reason, a rotating drum-shaped photoreceptor is used,
It has also been considered to increase the rigidity of the photoreceptor. However, the transparent substrate of the photoreceptor must be made of a transparent material, and although there are two types of transparent substrates, glass and acrylic, it is difficult to manufacture glass into a cylindrical shape with high precision, which increases costs. There was a problem that acrylic could not withstand the heat during vapor deposition of the conductive layer and could not be used for manufacturing.

[Means for solving problems]

FIG. 1 is a diagram for explaining the principle of an image forming apparatus according to the present invention. In the figure, 1 is an endless belt-like photoreceptor, which is made up of a transparent or semi-transparent conductive layer 1b and a photoconductive layer IC laminated in sequence on a transparent substrate la formed in the shape of an endless belt, and 2 is a toner. A developing means is provided on the photoconductive layer IC side of the endless belt-like photoreceptor 1 and supplies the toner 2a onto the endless belt-like photoreceptor 1; 3 is an image exposure means; A guide member 4 is provided on the side of the transparent substrate 1a and emits light according to the image to be formed and irradiates the transparent substrate 1a. 1 so that it passes through a predetermined path, and at least the portion that intersects with the optical axis 3a of the image exposure means 3 is constituted by a transparent member 4a.

[For production]

In the configuration described above, the endless belt-shaped photoreceptor 1 is supported by the guide member 4 so as to pass through a predetermined path, so there is no possibility of positional deviation (images (blurred images, uneven density, etc.)). No fogging occurs.

〔Example〕

(a) Description of an Embodiment FIG. 2 is a schematic configuration diagram for explaining an embodiment of an image forming apparatus according to the present invention.

In the figure, 11 is an endless photoreceptor belt. As shown in FIG. 3, the photoreceptor belt 11 has a thickness of 100 μm.
on a transparent substrate 11a of polyethylene terephthalate,
A transparent conductive layer 11b made of ITO (indium oxide) vapor deposited film is provided, and a CGL (charge generation J'S) lid and CTL (charge transport layer) 11e are provided as a photoconductive J#11c.
A functionally separated photoconductive layer made of an organic material is provided. A phthalocyanine material is used for the charge generation layer 1cGL, and an oxazole material is used for the charge transport layer CTL, and the combined thickness of both is as thin as 10 μm. Transparent conductive layer 1
1b is connected to ground. Note that the photoreceptor belt 1
In addition to the above-mentioned structure, 1 may have a structure in which an insulating layer is further provided on the photoconductive N 11 c.

The insulating layer is provided to neutralize the charges in the photoconductive layer 11c and toner charges so that electrostatic force does not disappear, and also to improve durability.

The photoreceptor belt 11 is stretched around a support roller 12 under a constant tension, and is fed by the support roller connected to a drive system.

Reference numeral 13 denotes a magnetic brush developing machine, which includes a cylindrical sleeve 13a made of a non-magnetic material and a magnet roller 13b rotatably provided inside the sleeve 13a. A recording electrode 15 insulated with a polyimide film 14 is attached to the surface of the sleeve 13a of the magnetic brush developing device 13.

Since the photoconductive layer 11c of this embodiment is of a hole movement type, a negative voltage 16 of opposite polarity is applied to the recording electrode 15.

This voltage is about -100 to -500v, preferably -
150 to -300v is suitable. Also, the sleeve 13a
, a positive voltage 1 of opposite polarity to the voltage 16 of the recording electrode 15 is applied.
Apply 7. This voltage 17 is approximately 0 to +50V, preferably +10 to +30V. A conductive magnetic toner 18 is used as the developer, and the toner 18 is transported by a magnet roller 13b. In addition to the conductive magnetic toner, the developer may be a mixed two-component toner in which a conductive magnetic toner is used as a carrier and an insulating magnetic toner is used as a toner.

At a position facing the recording electrode 15 across the photoreceptor belt 11, an LED array optical system 19 consisting of an LED array 19a and a SELFOC lens array 19b is installed as an image exposure means.

As shown in FIG. 4, inside the photoreceptor bell l-11,
A transparent plate 30 is provided as a conveyance guide.

The position of the LED array optical system 19 is set so that an image is formed on the surface of the transparent plate 30 on the side that is in contact with the photoreceptor belt 11.

20 is a toner image on the photoreceptor belt 11;

21 is a recording paper, and 22 is a conductive rubber roller for transfer, which is pressed against the photoreceptor belt with a constant pressure.

23 is a power source that applies voltage to the transfer roller 22;
4 is a toner image electrostatically transferred onto the recording paper 21;
is a heat fixing machine, and 26 is a semi-permanent recording image (elephant).

Reference numeral 27 indicates residual toner remaining on the photoreceptor belt after the transfer. Reference numeral 28 denotes a static eliminating light source that removes the charge of the residual toner 27 and the latent image charge in the photoconductive layer.

29 is a toner image which has been neutralized and has lost its electrostatic binding force.

Next, the image recording procedure will be described.

The photoreceptor belt 11 is rotated in the direction of the arrow, the magnet roller 13b of the developing device 13 is rotated, and an image is exposed by the LED array optical system 19 while applying a voltage. C.G.L.
Photocarriers are generated in llcl, and holes among the photocarriers move to the vicinity of the surface of the photoreceptor in c'rt and tie and become latent image charges.

In this way, in the exposed area, the capacitance of the photoconductive layer 11c increases apparently, so the amount of adhered toner increases, resulting in a toner image with a certain degree of contrast between the exposed area and the non-exposed area. Next, this toner image passes through an area with a toner pool in the developing area, and at this time, since a reverse voltage 17 is applied to the sleeve 13a, excess toner in the non-exposed area is collected by the developing machine 13 by electrostatic force. be done. At this time, a small amount of toner in the exposed area is also collected, but most of the toner remains on the photoreceptor belt 11 due to the electrostatic binding force of the latent image charge and the toner charge, and a toner image 20 is formed.

In the image exposure section, since the photoreceptor belt 11 is conveyed while contacting the transparent plate 30, the positional deviation of the photoreceptor belt is less than ±0.1 fold even if it comes into contact with the l. Ta.

The toner image 20 is transferred to a recording paper 21 using a transfer roller 22.
electrostatically transferred to The transferred toner image 24 is fixed on the recording paper by a heat fixing device 25, and a semi-permanent recorded image 26 is obtained.

On the other hand, the residual toner 27 that has not been transferred is removed by the static eliminating light source 2.
At step 8, the static electricity is removed and the electrostatic binding force is lost, and it is collected by the magnetic force of the developing device 13 and reused.

The next image formation is performed at the same time as toner collection. In this way, there is no problem in performing residual toner collection and image formation at the same time because the image (t2 exposure means 19 is located on the opposite side of the developing device 13).

('b) Description of other embodiments Fig. 5 is an explanatory diagram of another example of the LED optical system, and the same parts as in Figs. 2 and 4 are given the same numbers and their explanations are omitted. , 31 is a cylindrical member having a guide surface 31a for guiding the photoreceptor belt 11 to pass through a predetermined path, and a part of the guide surface 31a is a transparent member 31b through which light from the LED array 19a can pass. Furthermore, an LED array 19a is fixed to the inner peripheral surface.

Further, although not shown, a fan is provided on at least one side of the openings at both ends of the cylindrical member 31, and is configured to blow air toward the inner circumferential side of the cylindrical member 31.

With the configuration as described above, the cooling air is not diffused inside the photoreceptor belt 11, and the LED array 19a
can be efficiently cooled, the photoreceptor belt 11 does not vibrate, and the image does not deteriorate.

Furthermore, if a filter is provided at the opening of the cylindrical member 31, scattered toner and dust will not enter.

(C) Description of another embodiment FIG. 6 is a schematic configuration diagram for explaining another embodiment of the image forming apparatus according to the present invention.

In the figure, the same parts as in FIG. 2 are given the same numbers, and their explanations are omitted. 32 is a transparent hollow roller,
It is a cylindrical member made of transparent synthetic resin such as acrylic or glass, and is further provided to rotate in the direction of conveyance of the photoreceptor belt 11 and the second direction.
The support roller 12 on the recording section side shown in the figure is omitted.

Inside the transparent hollow roller 32, L is provided as an image exposure means.
An LED array optical system 19 consisting of an ED array 19a and a SELFOC lens array 19b is installed. As shown in FIG. 7, the LED array optical system 19' is fixed to the main body of the apparatus via a support member 35. Supported by the receiver 36 of the LED array optical system 19, the support member 35
It is designed to be able to rotate without contact. Support member 3
A cooling fan 33 and a filter 34 are attached to one side (the left side in the figure) of 5. The support member 35 is the eighth
It has a cylindrical structure as shown in the figure, and the central part 35a
The hollow portion 35b supports the LED array optical system 19 and allows cooling air from the cooling fan 33 to pass through the interior.
It is equipped with Although the cooling fan 33 is attached in this embodiment, it is also possible to close both ends of the transparent hollow roller 3 with filters 34 without attaching it. Furthermore, it is preferable to insert a sealing member between the transparent hollow roller 3e and the support member 35.

With the configuration described above, in addition to the effects obtained by the embodiments described above, the number of support rollers 12 can be reduced, and the structure can be simplified and made smaller.

〔Effect of the invention〕

As explained above, according to the present invention, since a transparent plate is installed between the exposure section and the development section to serve as a conveyance guide for the photoreceptor belt, it is easy to set the positions of the exposure section and the development section, and even after setting, the Clear images can be obtained because the body position does not shift.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 3 is a configuration diagram of a photoreceptor belt.
FIG. 4 is a perspective view of the image exposure section, FIG. 5 is an explanatory diagram of another example of the LED array optical system, and FIG. 6 is an explanatory diagram of another embodiment.
Fig. 7 is an explanatory diagram of another example of the LED optical system, and Fig. 8 is an explanatory diagram of another example of the LED optical system.
FIG. 9 is a schematic diagram of a conventional example, and FIG. 10 is a diagram illustrating a conventional image forming process. In the figure, 1 is an endless belt-shaped photoreceptor, 2 is a toner developing means,
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Claims (1)

[Claims] A photoconductive layer (1c) of a photoreceptor (1) comprising a transparent or translucent conductive layer (1b) and a photoconductive layer (1c) successively laminated on at least a transparent substrate (1a). ) side, a toner developing means (2) facing the toner developing means (2),
An image forming apparatus comprising an image exposing means (3) provided on the transparent substrate (1a) side of the photoreceptor (1), and forming a toner image by imagewise exposing the photoreceptor (1), The photoreceptor (1) is formed in the shape of an endless belt, and is in contact with the transparent substrate (1a) side of the endless belt-like photoreceptor (1), so that the endless belt-like photoreceptor (1) is guided along a predetermined path. A guide member (4) is provided at a position intersecting the optical axis (3a) of the image exposure means (3), and the guide member (4) guides the image exposure means (3) through the image exposure means (3). ) whose part intersects with the optical axis (3a) of the member (4) is transparent.
An image forming apparatus comprising: a). (2) A patent characterized in that the guide member includes a cylindrical member and filter members provided at both ends of the cylindrical member, and the image exposure means is enclosed in the cylindrical member. An image forming apparatus according to claim (1).