JP2003122144A - Image forming device - Google Patents

Abstract

(57) Abstract: Provided is an image forming apparatus capable of producing a printing plate using a conductive or semiconductive transfer material. SOLUTION: A conductive or semiconductive transfer material (13) is supplied so as to be in contact with an image carrier (1) on which a toner image has been formed, and the back surface of the transfer material is connected to two electrode members (4). , 7), and by applying a predetermined transfer bias to at least one of the two electrode members (4, 7), the toner image is transferred onto the transfer material to prepare a printing plate. It is characterized by doing.

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 for forming a toner image on a conductive or semi-conductive transfer material by using an electrophotographic method, and a conductive or semi-conductive transfer material. The present invention relates to an image forming apparatus that can be used as a material, particularly as a printing plate used as a printing plate.

[0002]

2. Description of the Related Art Conventionally, various devices utilizing an electrophotographic method are known, but among them, a so-called copying machine for copying or printing an image on a normal transfer material such as plain paper or film is typical. Image forming apparatuses such as printers are well known. In such an image forming apparatus, a photoconductor in which a photoconductive layer such as an organic photo semiconductor (OPC) is provided on the surface of a drum-shaped or belt-shaped conductive substrate made of aluminum or the like by coating or vapor deposition is used. An electrostatic latent image is formed on the surface by using a well-known electrophotographic method, and a visible toner image is formed by adhering toner to the electrostatic latent image. It is transferred onto a normal transfer material such as a film or a second original drawing.

In such transfer, usually, a transfer material is sent so as to be in close contact with the surface of a photoreceptor on which a toner image is formed, and at the contacted portion, a corona charger, a charging roller or the like is known from the back side of the transfer material. The transfer bias is applied by the means to electrostatically attract the toner on the photoconductor to the transfer material side.

On the other hand, in the recent printing industry, a print manuscript is created as digital data, and this data is directly read by an electronic plywood machine (DTP) and reproduced on a desktop to perform necessary processing and editing. . The data edited on the desktop is transferred to the plate-making machine through the network line, printed on a predetermined number of films as halftone dot data, and output. This film is printed on a printing plate, for example, a PS plate (a plate provided with a photosensitive layer),
It is used by being set on a printing machine as a printing plate such as an offset rotary press.

[0005]

By the way, the production of the above-mentioned printing plate has hitherto been carried out by printing data on a film as a first step, and then exposing, developing, washing, erasing and burning in a printing plate process. Many complicated steps are required, and an operator who is familiar with the work is required to perform these steps.

The present inventors have paid attention to the fact that the printing plate using the PS plate is performed by the above-mentioned image forming apparatus utilizing the electrophotographic system.

However, when an attempt is made to produce a printing plate by an image forming apparatus using the electrophotographic system having the above-mentioned structure, transfer using a normal transfer material having high electric resistance such as paper in the electrophotographic system is performed. It was difficult to obtain a clear image obtained with a transfer material such as paper when transferring to a PS plate which is a conductive or semi-conductive member under the condition of charging.

Therefore, the present inventors replaced the conventional transfer material having high electric resistance, such as paper and film, which has been used conventionally, with an apparatus for forming an image on a conductive or semiconductive transfer material. It is an object of the present invention to provide an image forming apparatus having a simple structure, which can be used for printing plates such as PS plates, and which can obtain a clear image with sufficient image accuracy. To do.

[0009]

In order to solve the above problems, a conductive or semi-conductive transfer material is supplied so as to be in contact with the image carrier on which a toner image is formed, and the conductive or semi-conductive transfer material is supplied. A back surface of a conductive transfer material is supported by two electrode members, and a predetermined transfer bias is applied to at least one of the two electrode members to transfer the toner image onto the transfer material. To do.

Further, the transfer material is plate-shaped.

Further, the electrode member is provided at an upstream position and a downstream position of the contact portion so as to straddle the contact portion between the transfer material and the image carrier when viewed in the supply direction of the transfer material. It is characterized by being

Alternatively, at least one of the two electrode members is located at a rear surface position of the transfer material at a contact portion between the image carrier and the transfer material.

Further, the transfer material is electrically insulated from at least the members other than the two electrode members and the image carrier at the time of transferring the toner image.

Further, the conductive or semiconductive transfer material is used as a printing plate for printing.

Particularly, a powder image made of lipophilic toner is formed on the surface of the electrophotographic photosensitive member, and the electroconductive or semiconductive transfer material is applied to the electrophotographic photosensitive member. The lipophilic toner powder is supplied by contacting the surface of the body and applying a predetermined transfer bias from the back side of the transfer material in a state where the transfer material is electrically floated from other members. It is characterized in that a body image can be transferred to the transfer material to produce a printing plate for printing.

Further, in particular, it is characterized in that a hydrophilic layer is provided on the surface of the transfer material or a treatment for making the surface hydrophilic is performed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. In the following examples, a conductive or semi-conductive transfer material (hereinafter referred to as a special transfer material) will be described as a printing plate for printing, but the special transfer material may be a PS plate or another type. The present invention can be applied to the conductive or semi-conductive member of.

FIG. 1 is a diagram showing the vicinity of a transfer portion for transferring a toner image on a transfer material of an image forming apparatus according to the present invention, and FIG. 1 shows a case of transfer to a special transfer material. As described above, in the example shown in FIG. 1, as the special transfer material,
The case where a transfer material in which a hydrophilic layer is provided on a substrate made of aluminum is used is shown.

The respective constituent parts constituting the transfer path and the transfer portion will be described in accordance with the transfer material supply direction (flow). In the figure, reference numeral 1 denotes a photosensitive layer made of an organic photoconductor such as copper phthalocyanine or an inorganic photoconductor such as selenium which is applied or vapor-deposited on the surface of a substrate made of metal such as aluminum which can be used as an image carrier. The electrophotographic photosensitive member rotates in the direction of arrow A. In this example, the image carrier 1 has a drum shape, but may have an endless belt shape.

Although not shown, a static eliminator such as an eraser lamp for electrically neutralizing the image carrier 1 around the image carrier 1 in accordance with the rotation direction A thereof, and a surface of the image carrier 1 having a specific polarity. A charging device such as a corona or a charging roller for uniformly charging with a laser, an exposure device for exposing optical information by a laser or an LED to form a desired electrostatic latent image on the surface of the charged image carrier 1. A developing device for supplying a toner powder, which is a charged powder, to the surface of the image carrier 1 to develop the electrostatic latent image formed on the image carrier 1 to form a toner powder image. They are provided, and these act on the image carrier 1 in order as the image carrier 1 rotates. As the image carrier 1 and the above-mentioned devices around the image carrier 1, the configuration of each part of an image forming apparatus using a well-known electrophotographic method can be applied. In this example, lipophilic toner is used as the toner powder.

Reference numeral 2 in the drawing is a guide for guiding the transfer material conveyed from a transfer material supply source (not shown) to the transfer portion 6 along the upper surface thereof, and further downstream of the guide 2, the transfer material is transferred. Preliminary guide 3 to prevent the material from falling down
Is provided. Reference numeral 4 in the figure denotes an electrode member which is a first electrode used for transfer to a special transfer material, and is composed of a conductive member and is located upstream when viewed from the transfer material conveyance direction of the transfer portion 6. There is.

As another transfer means and separation means, a charging roller in which a necessary bias is applied to each conductive roller may be used. Reference numeral 7 in the drawing denotes one conveying roller that supports a conveying belt 8 that is a means for conveying the transfer material on which the electrostatic latent image separated from the image carrier 1 is transferred to a fixing device (not shown). Also has a role of a second electrode for transfer to a special transfer material, and is composed of a conductive member.

As described above, according to the present invention, the conductive material is provided upstream and downstream, respectively, as viewed from the transfer material conveying direction (B direction) so as to straddle the contact portion 5 between the transfer material and the image carrier. The first and second electrode members 4 and 7 made of members are provided, and the special transfer material is supplied so as to be supported by these two electrode members 4 and 7 and to contact the surface of the image carrier at an appropriate pressure. To be done. Further, as for the electrode members 4 and 7, one or both of the two members may be arranged substantially at the back surface position of the transfer material in the contact portion 5 between the transfer material and the image carrier described above.

The arrangement position of the first electrode member 4 is particularly important, and it is preferable that the transferred transfer material surely comes into contact with the surface of the image carrier 1. For this reason,
The first and second electrode members 4 and 7 are provided near the upstream side and the downstream side of the transfer material 13 and the contact portion 5 of the image carrier 1. Although the second electrode is also used as the support roller 7 of the conveyor belt 8, the second electrode may be separated from the conveyor roller 7 and may be formed separately. In that case, the second electrode is a roller. It need not be limited in shape.

In the present invention, the transfer material used as one of the typical ones of the conductive or semiconductive special transfer materials is a conductive material of aluminum or the like having a conductivity of 0.1 to 0.5 mm.
A hydrophilic layer is provided on a substrate having a thickness of, or is subjected to a treatment for making it hydrophilic, which satisfies the printability in a commonly used offset printing machine. Alternatively, a conductive or semi-conductive member having a low electric resistance may be used.

Next, the operation of the electrode plate 4 which is the first electrode and the transfer roller 7 which is the second electrode of the transfer means of the present invention depending on the transfer material will be described. First, the electrode plate 4, which is the first electrode member constituting one electrode of the transfer means, is electrically connected to the DC power source 11 having the polarity opposite to the polarity of the toner image via the switch 9. Further, also in the transport roller 7 which is the second electrode member constituting the other electrode of the transfer means, it is connected through the switch 10 to the DC power source 12 having a polarity opposite to that of the toner image. These switches 9 and 10 are preferably used during image formation.
That is, it is controlled so that it is turned on only during the operation of transferring to the transfer material. Further, with respect to the application of the bias to the electrode members 4 and 7, it is not always necessary to apply the bias to both of the electrode members, and it is also possible to apply the bias to only one of the electrode members, if necessary. When a bias is applied to both electrodes, both bias potentials are substantially the same.

Also, the electrode plate 4 and the second electrode, which are the first electrodes, of the components that come into contact with the transfer material in order to convey the transfer material around the transfer portion 6, for example, the guide 2 and the preliminary guide 3. The parts other than the transport roller 7 and the image carrier 1 are
It is either completely electrically insulated or is electrically floated with respect to the ground through a varistor or the like.

Next, the operation of the apparatus according to the present invention will be described with reference to FIG. 1 when a special transfer material is used as the transfer material of this embodiment. First, the special transfer material 13 is inserted into the image forming apparatus by manual feeding or automatic feeding by a paper feed guide (not shown). The inserted special transfer material 13 is transported toward the transfer portion 6 of the image carrier 1 by the transport guide 2 and the preliminary guide 3, and the electrode plate 4 as the first electrode and the support roller 7 as the second electrode member. Is sent to the conveyor belt 8 via a fixing device (not shown) and is discharged to the outside of the device. When the special transfer material 13 passes through the transfer portion 6, the special transfer material 13 is formed by the two electrodes of the first electrode member 4 and the second electrode member 7 so that the surface of the special transfer material 13 comes into contact with the surface of the image carrier 1 with an appropriate pressure. The back surface is supported, and at this time, the first electrode member 4
The switches 9 of the second electrode member 7 and the second electrode member 7 are turned on, and a transfer bias having a value suitable for transfer to the special transfer material 13 is applied from each power source. Further, as described above, the electrical relationship with each of the parts constituting the transport path for transporting the special transfer material 13 including the transfer portion 6 and the like is all insulated, that is, electrically floating, and the electrode plate (first By rubbing the rear surface of the special transfer material 13 against the electrode member 4) and the conveying roller 7, it is possible to apply a bias to the special transfer material 13 and transfer the toner image to the special transfer material 13.

In the structure of this embodiment, the switches 9 and 10 of the first electrode member 4 and the second electrode member 7 are turned on, and the value of the bias applied between the image carrier 1 and the special transfer material 13 is changed. When the transfer to the transfer material was changed and the experiment was carried out, the surface potential of the non-image portion of the image carrier 1 was −750 to −850 V, and the surface potential of the image portion was 0 to −50.
V, if the toner polarity is negative, special transfer material 1
When the transfer was performed by setting the bias voltage to DC3 to 166V DC, a precise and clear preferable image could be obtained. The bias applied between the image carrier 1 and the special transfer material 13 is preferably opposite to the polarity of the toner, and when a bias of 250 VDC or more is applied, discharge is generated between the surface of the image carrier 1 and the special transfer material 13. However, the image becomes unclear, and the transfer efficiency deteriorates when a bias of 50 V or less is applied.
It is good to set it to 250V.

[0030]

In the image forming apparatus of the present invention, the back surface of the conductive or semi-conductive special transfer material is supported by the two electrode members in the transfer process to the conductive transfer material. Good transfer to the material can be obtained, and the simple structure can reduce the cost.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing an image forming apparatus according to the present invention.

[Explanation of symbols]

1 Image carrier 2 guides 3 preliminary guide 4 Electrode plate (first electrode member) 5 contact area 6 Transfer part 7 Transport roller (second electrode member) 8 conveyor belt 9 switch 10 switches 11 DC power supply 12 DC power supply 13 Special transfer material

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[Procedure amendment]

[Submission date] July 16, 2002 (2002.7.1)
6)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

Particularly, a powder image made of lipophilic toner is formed on the surface of the electrophotographic photosensitive member, and the electroconductive or semiconductive transfer material is applied to the electrophotographic photosensitive member. supplied so as to contact the surface of the body, the toner powder image of the lipophilic by applying a predetermined transfer bias from the back side of the transfer material in a state of floating the transfer material in electrical It is characterized in that it can be transferred to a transfer material to produce a printing plate for printing.

Continued front page    F-term (reference) 2H070 EE06 FF31 FF41                 2H084 AA19 AE05 BB02 BB13 CC05                 2H170 EE06 FF31 FF41                 2H200 FA17 FA18 GA01 GA09 GA23                       GA33 GA34 GA44 GA49 GB02                       HA02 HA12 HA28 HB12 HB14                       HB22 JA03 JA28 JB06 JB10                       MB01 MB02 MC20 NA02

Claims (8)

[Claims] 1. A conductive or semiconductive transfer material is supplied so as to contact an image carrier on which a toner image is formed, and the back surface of the conductive or semiconductive transfer material is provided with two electrodes. An image forming apparatus, wherein the toner image is transferred onto the transfer material by being supported by a member and applying a predetermined transfer bias to at least one of the two electrode members. 2. The image forming apparatus according to claim 1, wherein the transfer material is plate-shaped. 3. The electrode member is provided at an upstream position and a downstream position of the contact portion so as to straddle the contact portion between the transfer material and the image carrier when viewed in the transfer material supply direction. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 4. The at least one of the two electrode members is located at a back surface position of the transfer material at a contact portion between the image carrier and the transfer material.
Or the image forming apparatus described in 3. 5. The transfer material is in a state of being electrically insulated or electrically floated from at least the members other than the two electrode members and the image carrier at the time of transferring the toner image. The image forming apparatus according to claim 1. 6. The image forming apparatus according to claim 1, wherein the conductive or semiconductive transfer material is used as a printing plate for printing. 7. An electrophotographic photosensitive member is provided with a powder image formed of a lipophilic toner on the surface thereof, and the electroconductive or semiconductive transfer material is applied to the electrophotographic photosensitive member. The lipophilic toner powder is supplied by contacting the surface of the transfer material and applying a predetermined transfer bias from the back side of the transfer material while electrically floating the transfer material from other members. An image forming apparatus capable of transferring an image to the transfer material to produce a printing plate for printing. 8. The image forming apparatus according to claim 6, wherein a hydrophilic layer is provided on the surface of the transfer material or a treatment for making the surface hydrophilic is performed.