JP2701768B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus using an electrophotographic system, such as a laser printer and an LED printer.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using this type of electrophotographic system generally employs a so-called Carlson method.
The photoreceptor, which is an electrostatic latent image forming member, is charged, exposed, and developed to transfer a developed image on the surface of the photoreceptor to a recording medium, and then fix the developer on the recording medium to form an image. Japanese Patent Application Laid-Open No. 5-72917 discloses a method in which a developed image formed on a photoreceptor surface is transferred to a belt-shaped intermediate transfer carrier, and an image on the intermediate transfer carrier is transferred and simultaneously fixed to a recording medium to form an image. It is introduced in the official gazette. further,
The construction of a color electrophotographic apparatus using a similar method is disclosed in
No. 3,372,972. In both devices, a fixing unit is shown using a linear solid heating element. Further, Japanese Patent Application Laid-Open No. 3-54585 proposes a device in which a heating element is provided in a belt-shaped photoconductor, and a developed image formed on the photoconductor is transferred to a recording medium and fixed at the same time. Furthermore, Japanese Patent Application Laid-Open No. 4-181
No. 961 discloses a method of transferring an electrostatic latent image formed on an electrostatic latent image forming body onto a film, forming a developed image on the film, and transferring the developed image on the film to a recording medium by two rollers. Transfer and fix by passing through the fixing unit,
An image forming apparatus has been proposed.

[0003]

However, the prior art has the following problems. First, according to the generally used Carlson method, for example, many processes are arranged around a photoreceptor which is an electrostatic latent image forming body, and the entirety for disposing a fixing unit is horizontally long. There is a problem that it is difficult to reduce the size due to the configuration. Therefore, there is a configuration in which a fixing unit is disposed above the layout of the electrostatic latent image forming member by transferring the image to the recording medium on the lateral side of the electrostatic latent image forming unit. There are issues such as lacking. In JP-A-5-72917,
In addition to the photoreceptor drive, there are problems such as high cost due to the drive system of the intermediate transfer carrier, image deterioration due to double transfer of the developed image, and difficulty in miniaturization. Japanese Patent Application Laid-Open No. 4-372972 has the same problem. JP-A-3-54
No. 585 has problems such as a change in the characteristics of the photoconductor due to overheating of the photoconductor, a problem of reliability, and a complicated mechanical system due to the arrangement of the belt driving roller group. There is also a question of miniaturization. Japanese Patent Application Laid-Open No. Hei 4-181961 has an advantage that the surface of the electrostatic latent image forming body is protected and can be used for a long life.
There is a problem with the device size. Even if an endless film is used, the film is overheated by the heat roller, affecting the electrostatic latent image forming body, and there is a problem in characteristics change and reliability.

[0004]

According to the present invention, there is provided an image forming apparatus comprising: an electrostatic latent image forming member; a belt-shaped developed image carrier which closely contacts the electrostatic latent image forming member; Means for forming a latent image on a body, a developing device for supplying a developer onto the belt-shaped developed image carrier, and the developer on the belt-shaped developed image carrier closely attached to the inner surface of the belt-shaped developed image carrier A first line-shaped solid heating element for preheating the developer, and a second step for transferring and fixing the developer preliminarily heated by the first line-shaped solid heating element in close contact with the inner surface of the belt-shaped developed image carrier on a recording medium. 2 line-shaped solid heating elements.

Further, the image forming apparatus of the present invention is characterized in that the latent image forming means is disposed inside the belt-shaped developed image carrier.

Further, in the image forming apparatus according to the present invention, the latent image forming means may form a latent image at a position where the belt-shaped developed image carrier and the electrostatic latent image forming body come into close contact with each other. It is provided around the belt-shaped developed image carrier.

Further, the image forming apparatus according to the present invention is characterized in that the developing device is disposed to face the belt-shaped developed image carrier at a position where the belt and the electrostatic latent image forming body are in close contact with each other. I do.

Further, in the image forming apparatus according to the present invention, the developing unit may face the outer surface of the belt-shaped developed image carrier at a position other than a position where the belt-shaped developed image carrier and the electrostatic latent image forming body are in close contact with each other. It is characterized by being provided.

Further, the image forming apparatus of the present invention is characterized in that the electrostatic latent image forming body is in a drum shape.

Further, the image forming apparatus according to the present invention is characterized in that the electrostatic latent image forming body has a belt shape.

[0011]

In the image forming apparatus of the present invention, an electrostatic latent image is formed on the electrostatic latent image forming body, and the electrostatic latent image forming body is brought into close contact with the inner surface of the belt-shaped developed image carrier to form the electrostatic latent image. The electrostatic latent image on the belt-shaped developed image carrier is developed with a developer supplied from a developing device to form a developed image, and the developed image on the belt-shaped developed image carrier is converted into a first linear solid heating element. , And then the developed image is transferred and fixed on the recording medium at the position of the second linear solid heating element.

According to the image forming apparatus of the present invention, an electrostatic latent image is formed on an electrostatic latent image forming member which is partially adhered to the inner surface of the belt-shaped developing image carrier, and the electrostatic latent image is formed on the belt-shaped developing image carrier. Forming a latent image, then forming a developed image on a belt-shaped developed image carrier with a developing device, and preheating the developed image on the belt-shaped developed image carrier with a first linear solid heating element; Next, the developed image is transferred and fixed on the recording medium at the position of the second linear solid heating element.

As described above, the developer, which forms a developed image with the first linear solid heating element, is preliminarily heated and temporarily melted, and is then transferred to the recording medium by the second linear solid heating element. Since the transfer and fixing are performed simultaneously, the heat stress on the heating element and the developed image carrier is reduced, the reliability of each is improved, and the temporary melting By transferring the developed image to the recording medium and fixing it at the same time, the transfer efficiency and image quality without dust are excellent, and the temperature rise of the belt-shaped developed image carrier with almost no heat capacity can be prevented. This does not have a thermal effect on the next contact with the electrostatic latent image forming body, so that a stable electrostatic latent image is formed.

[0014]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention. Referring to FIG. 1, the image forming apparatus according to this embodiment includes:
A drum-shaped photoreceptor 1 which is an electrostatic latent image forming body, and a belt-shaped developed image carrier 2 in close contact with the surface of the drum-shaped photoreceptor 1
A charging roller 8 as a means for forming a latent image on the drum-shaped photoreceptor 1, an LED optical system 3, a developing device 4 for supplying a developer onto the belt-shaped developed image carrier 2, and a belt-shaped developed image carrier 2
A first line-shaped solid heating element 5 that is in close contact with the inner surface and preheats the developer on the belt-shaped developed image carrier 2, and a first line-shaped solid heating element 5 that is in close contact with the inner surface of the belt-shaped developed image carrier 2 And a cleaner that removes residual developer from the surface of the belt-shaped developed image carrier 2 and removes the residual charge uniformly from the surface of the belt-shaped developed image carrier 2. 10 and a static eliminator 11.

Drum-shaped photosensitive member 1 as an electrostatic latent image forming member
Has an organic photosensitive agent (OPC) or an inorganic photosensitive agent formed on the surface. The belt-shaped developed image carrier 2 closely adheres to the inner surface of the drum-shaped photoconductor 1 along the surface curvature, and rotates at the same speed as the drum-shaped photoconductor 1 rotates. The belt-shaped developed image carrier 2 is further provided with first and second linear solid-state heating elements 5 and 6 on its inner surface in close contact with each other, and further provided with an idler tension roller 7 for supporting rotational movement. Have been. In the inside of the belt-shaped developed image carrier 2, an image is exposed according to image data according to a charging roller 8 for charging the drum-shaped photoconductor 1 as an electrostatic latent image forming body, and an electrostatic latent image is formed on the drum-shaped photoconductor 1. An LED optical system 3, which is a latent image forming unit having a linear LED for forming,
Drum-shaped photoconductor 1 along the rotation direction of drum-shaped photoconductor 1
It is arranged close to or close to the surface. At a portion where the second linear solid heating element 6 is located, a pressure roller 9 is rotatably pressed against the second linear solid heating element 6 via the belt-shaped developed image carrier 2. . Also,
On the outer surface of the belt-shaped developed image carrier 2 between the drum-shaped photoreceptor 1 of the belt-shaped developed image carrier 2 and the idler tension roller 7, a developer for forming a developed image is applied. A developing device 4 to be supplied to the carrier 2 is arranged close to or in contact with the developing device 4. Further, a portion of the belt-shaped developed image carrier 2 between the second linear solid-state heating element 6 and the drum-shaped photoconductor 1 is provided with a cleaner 1 on its outer surface.
0 and a static eliminator 11 are provided. The cleaner 10 is for transferring and fixing the developed image on the belt-shaped developed image carrier 2 to the recording medium 12 with a blade cleaner, and then removing the developer remaining on the surface thereof. An AC corona discharger is shown here for uniforming the charge distribution of the developed image carrier 2, and is a process device for preparing an image on the next belt-shaped developed image carrier 2. is there. An opposed support member is provided on the inner surface of the belt-shaped developed image carrier 2 so as to face the cleaner 10 and the static eliminator 11. In this embodiment, the belt-shaped developed image carrier 2 is made of heat-resistant polyimide, polyetherimide, polyester, or the like.
Those having a thickness of about 100 μm or less are used. Further, the outer surface thereof is subjected to a silicon or fluorine-based surface treatment for giving a releasability of the developed image. As the first and second linear solid-state heating elements 5 and 6, a ceramic heating element, a sheath heater, a surface heating element having a thin-film high-resistance element formed on the surface, or the like is used.

Next, the operation of this embodiment will be described. The drum-shaped photoreceptor 1 is driven to rotate by a driving motor (not shown). After the surface is uniformly charged by a charging roller 8, an electrostatic latent image is formed by an LED optical system 3 which selectively emits light in accordance with image information. It is formed. The drum-shaped photoreceptor 1 and the belt-shaped developed image carrier 2 come into contact with each other with rotation, and are closely overlapped. Accordingly, a charge pattern according to the charge distribution of the electrostatic latent image formed on the surface of the drum-shaped photoconductor 1 is formed on the outer surface of the belt-shaped developed image carrier 2. Corresponding to the charge distribution on the surface of the drum-shaped photoreceptor 1, a charge distribution due to the opposite polarity charge is formed on the inner surface of the belt-shaped developed image carrier 2, which is in close contact with the surface. A charge distribution is also formed on the outer surface. Drum-shaped photoreceptor 1
Belt-like developed image carrier 2 moving at the same speed as the peripheral speed of rotation
Next, the developer is supplied to the outer surface of the developing device 4 so as to face the developing device 4, and a developed image is formed in accordance with the charge distribution. on the other hand,
The drum-shaped photoconductor 1 is separated from the belt-shaped developed image carrier 2,
The process proceeds again to the formation of the next electrostatic latent image. The belt-shaped developed image carrier 2 having a developed image formed on its surface moves onto the first linear solid heating element 5 as it moves, and is heated by the first linear solid heating element 5. Since the belt-shaped developed image carrier 2 has almost no heat capacity, the amount of heat supplied and supplied is applied to the developer forming the developed image to melt the developer. However, it does not reach the point where it is completely melted, and the second linear solid heating element 6 is applied to the recording medium 12 that is conveyed synchronously by the paper feed roller 13 at the next second linear solid heating element 6. The developed image is transferred and completely fused and fixed by heating from the body 6, applying pressure from the back surface of the recording medium 12 by the pressure roller 9 and applying a transfer bias (not shown). Thus, a fixed image is formed on the surface of the recording medium 12. After transferring the developed image to the recording medium 12, the belt-shaped developed image carrier 2 removes the residual developer on the surface by the cleaner 10, and the residual charge distribution is made uniform by the static eliminator 11. Used to The belt-shaped developed image carrier 2 that has passed through the second line-shaped solid heating element 6 has a smaller heating heat amount than a heat roller having a large heat capacity or a single solid heating element. Since the heat capacity of the developed image carrier 2 itself is almost nil, and there is also a heat radiation effect due to the connection of the cleaner 10 and the static eliminator 11 to the opposing member disposed on the opposing back surface, there is almost no temperature rise. It can be used without problem for forming images.

FIG. 2 is a diagram showing the configuration of a second embodiment of the present invention. Referring to FIG. 2, in the image forming apparatus of this embodiment, the belt-shaped developed image carrier 2 is provided with a belt-shaped photoreceptor 14 which is an electrostatic latent image-forming body that is brought into close contact with a part of its inner surface and moves at the same time. doing. The belt-shaped photoconductor 14 and the belt-shaped developed image carrier 2 are simultaneously moved and driven by the rotation driving roller 15 without slip. Belt-shaped developed image carrier 2
An LD optical system 17 comprising a semiconductor laser optical system, which is an electrostatic latent image forming means for forming an electrostatic latent image on the belt-shaped photoreceptor 14 from the outer surface side, is disposed so as to expose toward the rotation driving roller 15. Have been. After the exposure position, a developing unit 4 for supplying a developer for forming a developed image is provided on the side of the belt-shaped developed image carrier 2 where the belt-shaped photoconductor 14 and the belt-shaped developed image carrier 2 are in close contact with each other. Are arranged close to or in contact with each other. On the inner surface of the belt-shaped developed image carrier 2, first and second linear solid-state heating elements 5 and 6 are arranged in close contact. In particular, at the portion where the second linear solid heating element 6 is located, the pressing roller 9 is rotatably pressed against the second linear solid heating element 6 via the belt-shaped developed image carrier 2. ing. A grounded conductive material is provided between a portion where the belt-shaped developed image carrier 2 and the second line-shaped solid heating element 6 are in contact and a portion where the belt-shaped developed image carrier 2 and the belt-shaped photoconductor 14 are in contact. Cleaner 1 with blade
0 is provided. The support members of the first and second line-shaped solid heating elements 5 and 6 insulate and support a charging blade 16 for charging the belt-shaped photoreceptor 14, and also serve as a cleaner facing member. The belt-shaped photoreceptor 14 is formed by forming a conductive layer and a photosensitive material layer on a base material made of polyethylene terephthalate, polyethylene, polyimide, polyester, or the like. The photosensitive material is an organic photosensitive material (OPC) or an inorganic photosensitive material. Materials are used.
As the belt-shaped developed image carrier 2, the same one as in the first embodiment is used, but it has a light-transmitting property with respect to the light wavelength used in the LD optical system 17. The first and second linear solid heating elements 5 and 6 are the same as those in the first embodiment.

Next, the operation of this embodiment will be described. The rotation of the rotation driving roller 15 causes the belt-shaped photoconductor 14 and the belt-shaped developed image carrier 2 to rotate.
The belt-shaped photoreceptor 14 is uniformly charged by a charging blade 16 connected to a power supply output (not shown), and is closely contacted with the belt-shaped developed image carrier 2 and is driven by a rotation driving roller 15.
Near the LD optical system 17 through the belt-shaped developed image carrier 2
Is selectively exposed according to image information. The belt-shaped photoconductor 14 forms an electrostatic latent image by exposure, and at the same time, the belt-shaped developed image carrier 2 corresponding to the charge distribution of the electrostatic latent image.
A charge distribution is also formed. The process is the same as in the operation of the first embodiment. After the formation of the electrostatic latent image, the belt-shaped photoreceptor 14 and the belt-shaped developed image carrier 2 move and face the developing device 4, where they are developed by the developer in accordance with the charge distribution, and the belt-shaped developed image carrier is developed. 2, a developed image is formed. The belt-shaped developed image carrier 2 having the developed image formed on the surface is heated by the first linear solid heating element 5, and the surface developer is heated and melted. However, it is not completely melted, but is transported to the next second linear solid heating element 6. In the portion of the second linear solid heating element 6, the paper is fed by heating from the second linear solid heating element 6, pressing by the pressing roller 9 from the back surface of the recording medium 12, and applying a transfer bias (not shown). At the same time that the developed image is transferred to the recording medium 12 conveyed in synchronization by the rollers 13, the fused image is completely fused and fixed. Thus, a fixed image is formed on the surface of the recording medium 12. On the other hand, after the developing process, the belt-shaped photoconductor 14 separates from the belt-shaped developed image carrier 2, advances to the charging blade 16, and advances to the formation of an electrostatic latent image for the next image formation. After the transfer of the developed image to the recording medium 12, the belt-shaped developed image carrier 2 is subjected to removal of the residual developer on the surface and elimination of electricity by the cleaner 10 having the grounded conductive blade, and proceeds to the next image formation. . Here, as in the case of the first embodiment, the temperature of the belt-shaped developed image carrier 2 hardly increases after passing through the second line-shaped solid heating element 6, and then the belt-shaped photoconductor 14 Belt-shaped photoreceptor 14
Has no thermal effect.

Although two embodiments have been described above, the present invention is not limited to these embodiments. Any combination of the type and position of the optical system described as the electrostatic latent image forming means, the relationship with the shape of the electrostatic latent image forming body, and the arrangement position of the developing device may be used. Further, the electrostatic latent image forming body is not limited to the photoreceptor, but may be a dielectric member. In that case, an electrostatic head, an ion flow head or the like is used as the electrostatic latent image forming means. As the developer, not only a powder developer but also a liquid developer or a high-viscosity developer may be used. Although the traveling shape of the belt-shaped developed image carrier also shows only a substantially triangular shape, it is not particularly limited to this. Other configurations, shapes, and device arrangements made within the scope of the present invention are, of course, not particularly limited.

[0020]

As described above, according to the present invention,
An electrostatic latent image forming body, a belt-shaped developed image carrier that closely contacts the electrostatic latent image forming body, a latent image forming unit for the electrostatic latent image forming body, and developing on the belt-shaped developed image carrying body A first line-shaped solid heating element that is in close contact with the inner surface of the belt-shaped developed image carrier and preheats the developer on the belt-shaped developed image carrier; The following effects can be obtained by providing a second linear solid heating element that closely adheres and transfers and fixes the developer preheated by the first linear solid heating element to a recording medium. 1. Since the electrostatic latent image forming body does not directly adhere the developed image, there is no contamination by the developer, and no generation of abrasion or scratches by the cleaner or the recording medium, and it can be used stably for a long period of time. 2. Since simultaneous transfer and fixing to a recording medium are performed, high quality image formation with little image deterioration can be performed. 3. Since the developer is temporarily melted in advance and then re-heated and fixed at the time of transfer, the scattering of the developer is less than that of heating and fixing at once like conventional simultaneous transfer fixing, Further, the transfer efficiency is improved, and the fixing property is also excellent. 4. Thermal stress on the belt-shaped developed image carrier can be reduced,
Since the line-shaped solid heating element is dispersed in the heat supply, a low-cost heating element having a small calorific value can be used, and the reliability can be further improved. 5. Compared to conventional heat roller fixing or fixing with only one solid heating element, heat dispersion by the combination of a belt-shaped developed image carrier with a small heat capacity and two solid heating elements is used.
Thermal stress and temperature rise on the belt-shaped developed image carrier can be significantly reduced, and the characteristics of the belt-shaped developed image carrier during operation can be stabilized, and a low-cost material can be used. 6. Since there is no rise in the temperature of the belt-shaped developed image carrier, the thermal effect on the electrostatic latent image forming body is greatly reduced, so that a compact image forming apparatus configuration can be realized. 7. The degree of freedom in each process arrangement in the apparatus is increased, and various apparatus designs are possible.

As described above, a compact, highly reliable, and low cost image forming apparatus can be realized by the image forming apparatus of the present invention, and the effect is remarkable.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drum-shaped photoreceptor (electrostatic latent image forming body) 2 Belt-shaped developed image carrier 3 LED optical system 4 Developing device 5 First linear solid heating element 6 Second linear solid heating element 7 Idle tension roller 8 Charging roller 9 Pressure roller 10 Cleaner 11 Static eliminator 12 Recording medium 13 Feed roller 14 Belt-shaped photoreceptor (electrostatic latent image forming body) 15 Roller driving roller 16 Charging blade 17 LD optical system

Claims (7)

(57) [Claims] An electrostatic latent image forming member, a belt-shaped developed image carrier that closely contacts the electrostatic latent image forming member, a latent image forming means for forming the electrostatic latent image forming member, and the belt-shaped developing image carrier. A developing device that supplies a developer onto the developed image carrier, and a first line-shaped solid heating element that is in close contact with the inner surface of the belt-shaped developed image carrier and preheats the developer on the belt-shaped developed image carrier And a second line-shaped solid heating element that closely adheres to the inner surface of the belt-shaped developed image carrier and transfers and fixes the developer preheated by the first line-shaped solid heating element to a recording medium. Characteristic image forming apparatus. 2. An image forming apparatus according to claim 1, wherein said latent image forming means is disposed inside said belt-shaped developed image carrier. 3. The apparatus according to claim 1, wherein said latent image forming means forms a latent image around said belt-shaped developed image carrier at a position where said belt-shaped developed image carrier and said electrostatic latent image carrier are in close contact with each other. The image forming apparatus according to claim 1, wherein the image forming apparatus is provided. 4. The image forming apparatus according to claim 1, wherein the developing device is disposed so as to face the belt-shaped developed image carrier and the electrostatic latent image forming body in close contact with each other. The image forming apparatus as described in the above. 5. The image forming apparatus according to claim 1, wherein the developing device is disposed so as to face the outer surface of the belt-shaped developed image carrier at a position other than a position where the belt-shaped developed image carrier and the electrostatic latent image forming body are in close contact with each other. The image forming apparatus according to claim 1, wherein: 6. The image forming apparatus according to claim 1, wherein said electrostatic latent image forming body is in a drum shape. 7. The image forming apparatus according to claim 1, wherein said electrostatic latent image forming body is in a belt shape.