JP2003165243A - Imaging method, transfer method and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which can form images to solid bodies to be imaged such as PET bottles. <P>SOLUTION: A positive polarity fly voltage is impressed to a doughnut-shaped fly control electrode 106Bk set at a fly control plate 103Bk, thereby flying a group of negative polarity toner Tk held by a toner holding roller 102Bk in the form of dots. The toner is brought into a hole 105Bk set in the fly control plate 103Bk. Meanwhile, minute liquid drops 12 jetted from a liquid drop jet unit 10 are passed through a plate-shaped grounded electrode 9 and a needle- shaped electrode 8 with a positive polarity voltage impressed, and then allowed to adhere to the PET bottle Bp. The adhesion of minute liquid drops charged to be positive in the polarity by corona discharge between both electrodes forms an electric field between a surface of the bottle and the fly control electrode 103Bk, so that the toner of the hole 105Bk is continued to fly and allowed to adhere to the bottle surface. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and a transfer method for forming an image with toner on an image forming body, and a facsimile using the image forming method.
The present invention relates to an image forming apparatus such as a printer or a copying machine.

[0002]

2. Description of the Related Art Conventionally, an image forming method is known in which an image is formed on an image forming body such as transfer paper by a so-called electrophotographic method. In this electrophotographic system, an image is formed by the following process. That is, an electrostatic latent image is formed on a latent image carrier such as a photosensitive drum, and toner is electrostatically attached to the electrostatic latent image by the developing means to obtain a toner image. Then, the toner image is formed by directly transferring the toner image to the image forming body or indirectly transferring the image through the intermediate transfer. In these direct transfer and indirect transfer, a transfer electric field is formed between a transfer source member (for example, a latent image carrier) and a transfer bias member such as a transfer roller, and an image formation target is allowed to enter between them. As a result, an electrostatic force toward the image forming body is generally applied to the toner image on the transfer source member. In such transfer, the thicker the image-formed body, the more
It is necessary to secure a large distance between the transfer source member and the transfer bias member so that it can be interposed. However, if it is set too long, it is necessary to apply a high voltage to the transfer bias member that does not match the actual situation in order to form an effective transfer electric field between the transfer source member and the transfer bias member. Is limited. Therefore, usable image forming bodies are limited to thin materials such as paper materials and resin films. An image forming apparatus for forming an image on an optical disk such as a CD-ROM is also known (for example, Japanese Patent Laid-Open No. 5-212857), but even in the case of this apparatus, the thickness of the optical disk as the image formed object is at most 1 to 2 [. mm], and it is extremely difficult to form an image on a three-dimensional image forming body such as a PET bottle or a glass bottle.

On the other hand, conventionally, there is also known an image forming method for forming an image by a direct recording method called direct toning or toner projection.
In this direct recording method, an image is directly recorded on an image forming body, instead of performing a process of transferring a toner image obtained by development to the image forming body. Specifically, an image is directly formed on an image forming body by using a toner carrier such as a toner carrier roller, a counter electrode facing the toner carrier, and a toner flight control plate arranged between the two. The toner flight control plate is provided with a plurality of combinations of holes that are through openings and doughnut-shaped flight control electrodes that surround the holes. When a flight voltage is applied to an arbitrary flight control electrode, a toner aggregate flies in a dot shape from a toner carrier area facing the flight control electrode and enters a hole inside the flight control electrode. Then, due to the effect of the counter voltage applied to the counter electrode, the flying continues from the inside of the hole toward the counter electrode and adheres to the recording paper or the like on the counter electrode to form a dot image. In such a direct recording method, if the toner particles charged to the same polarity are caused to fly laterally by electrostatic repulsion between the hole and the counter electrode, the dot image is blurred. Make the concentration low. Therefore, regarding the electric field for continuing the flight of the toner that has entered the holes toward the counter electrode,
It is necessary to form the toner with a strength capable of suppressing the lateral diffusion of the toner. If the distance between the hole and the counter electrode is too large, it becomes extremely difficult to obtain such strength. On the other hand, it is necessary to interpose an image formed body such as recording paper between the hole 2 and the counter electrode. Therefore, even in the direct recording method, as in the electrophotographic method, it is necessary to use a thin material such as a sheet material or a plate-shaped material as the image forming object, and it is not possible to use a three-dimensional object such as a PET bottle or a glass bottle. It was extremely difficult.

[0004]

The present invention has been made in view of the above background, and an object of the present invention is to provide an image forming method capable of forming an image on a three-dimensional image forming body. A transfer method and an image forming apparatus are provided.

[0005]

The present inventor has assumed the use of a three-dimensional image forming body in an electrophotographic system or a direct recording system. Then, we focused on the matters explained below. That is, for example, when a PET bottle is used as the image forming body in the direct recording method, it is necessary to secure the distance between the hole and the counter electrode to be equal to or larger than the width of the PET bottle. Although it depends on the size of the PET bottle, at least a few [cm] is required even for the 500 [ml] size. However, the distance between the surface of the PET bottle placed on the counter electrode and the hole (toner flying distance from the hole to the bottle surface) is on the order of several hundreds μm at most. In order for the toner in the holes to reach the surface of the bottle, it suffices to form an electric field in such a small space of several hundred μm. Nevertheless, while forming an electric field in a very large space such as several [cm] from the bottle surface to the counter electrode via the inside of the bottle, a desired electric field strength can be obtained between the hole and the bottle surface. I will try to get it. Therefore, as an image forming method for general users, it becomes necessary to apply a high voltage to the counter electrode, which is not suitable for the actual situation. This also applies to the electrophotographic system.
It is sufficient to form the transfer electric field only between the transfer source member such as the latent image carrier and the bottle surface. Nevertheless, since an electric field is formed in a very long space of several [cm] from the bottle surface to the transfer bias member via the inside of the bottle, it is necessary to apply a transfer bias of extremely high voltage. is there. If an electric field is formed only in a small space required for toner flight or transfer, such an excessive voltage is not necessary.

Therefore, in order to achieve the above object, the invention of claim 1 is directed to a toner carrier for carrying charged toner, and a plurality of flight controls for controlling the flight of the toner from the toner carrier. An electrode and a plate member having a plurality of through openings facing the toner carrier are prepared in advance,
A step of applying a flight voltage to the flight control electrode; a step of allowing the toner flying from the toner carrier by the flight voltage to pass through the through opening; In the image forming method for forming an image by carrying out the steps, the surface of the image forming body before the toner is attached is charged with a polarity opposite to the charging polarity of the toner. According to a second aspect of the present invention, in the image forming method according to the first aspect, the liquid having the opposite polarity charge is attached to the surface of the image forming body before the toner is attached to charge the surface. It is characterized by that. According to a third aspect of the invention, in the image forming method according to the first aspect, the solid fine particles having the opposite polarity charge are attached to the surface of the image forming body before the toner is attached, and the surface is charged. It is characterized by that. According to a fourth aspect of the invention, in the image forming apparatus according to the first aspect, the surface of the image forming body before the toner is attached is electrically charged. According to a fifth aspect of the invention, in the image forming method according to the second aspect, the one in which a soluble resin is dissolved in a solvent is used. Further, the invention of claim 6 is characterized in that, in the image forming method of claim 2, a liquid which becomes a solid at room temperature is liquefied and used as the liquid. According to a seventh aspect of the invention, in the image forming method according to the second, third or sixth aspect, a curable resin or a plastic resin is used as the solid fine particles, or a curable resin or a plastic resin is contained as the liquid. It is characterized by using. The invention according to claim 8 is characterized in that, in the image forming method according to claim 7, a toner containing a curing agent for the curable resin or a plasticizer for the plastic resin is used as the toner. is there. The invention according to claim 9 is the image forming method according to claim 7 or 8, characterized in that the curable resin or the plastic resin is made of the same material as that of the image forming body. is there. According to a tenth aspect of the invention, in the image forming method according to the second, third, fifth, sixth, seventh, eighth or ninth aspect, the opposite polarity charge is applied to the solid fine particles or liquid by corona discharge. It is characterized by. Further, the invention of claim 11 relates to claims 2, 3, 5,
In the image forming method of 6, 7, 8 or 9, the charge of the opposite polarity is applied to the solid fine particles or liquid by charge injection. The invention of claim 12 is the invention of claim 2, 3, 5, 6, 7, 8 or 9.
In the above image forming method, the solid fine particles or the liquid is charged to the opposite polarity by friction. In addition, the invention of claim 13 is based on claims 2, 3,
The image forming method of 5, 6, 7, 8 or 9 is characterized in that the solid fine particles or liquid is charged to the opposite polarity by electrostatic induction. In addition, claim 14
The invention of Claims 2 to 3, 5, 6, 6, 7, 8, 9, 10,
In the image forming method of 11, 12 or 13, opaque and colored ones are used as the solid fine particles or liquid. The invention according to claim 15 is the image forming method according to claim 2, 5 or 6, characterized in that the liquid is adhered to the image forming body with a thickness of 1 [μm] or more. is there. Further, the invention of claim 16 relates to claims 2, 3, 4, 5, 6, 7, 8,
In the image forming method of 9, 10, 11, 12, 13, 14 or 15, 2 is provided between the flight control electrode to which the flight voltage is applied and the surface of the image forming body charged to the opposite polarity. It is characterized by forming an electric field having an intensity of ⁶ [V / m] or more. In addition, the invention of claim 17 relates to claims 2, 3, 5, 6, 7, 8, 9, 10, 11,
In the image forming method of 12, 13, 14, 15 or 16, the solid fine particles or the liquid is attached only to a predetermined area capable of containing an image to be formed among all the areas on the surface of the image forming body. It is what The invention according to claim 18 is the image forming method according to claim 7, 8 or 9, wherein a thermoplastic resin is used as the plastic resin, and the toner is provided on the solid fine particles or liquid adhered to the image forming object. The method is characterized in that the image formation target is heated before the application of the. In addition, claim 1
The invention of claim 9 relates to claims 1, 2, 3, 4, 5, 6, 7, 8,
9, 10, 11, 12, 13, 14, 15, 16, 17
Alternatively, in the image forming method of 18, the charge is removed from the image forming body after image formation. In these image forming methods, a flight voltage is applied to the flight control electrode to cause the toner to fly from the toner carrier to enter the through-opening of the plate-shaped member, while the surface of the image-formed body is charged with the charged polarity of the toner. It is charged in the opposite polarity to cause a potential difference between the flight control electrode and the surface of the image forming body. Due to this potential difference, it is possible to form an electric field capable of continuing the flight of the toner in the through opening toward the surface of the image forming body. With such a configuration, it is not necessary to dispose a counter electrode on the back surface side of the image forming body and apply a counter voltage to the counter electrode as in the conventional direct recording method. And
This eliminates the situation that a high voltage that does not match the actual situation has to be applied to the counter electrode due to the three-dimensional thickness of the image forming body, and forms an image on the image forming body. be able to. According to a twentieth aspect of the present invention, a toner carrier carrying charged toner, a plurality of flight control electrodes for controlling the flight of the toner from the toner carrier, and a plurality of penetrating holes facing the toner carrier. A step of applying a flight voltage to the flight control electrode by preparing a plate-shaped member having an opening and a facing member facing the toner carrier through the plate-shaped member, and applying the flight voltage A step of allowing the toner flying from the toner carrier to pass through the through opening; a step of attaching the passed toner to the facing member; and a toner image formed on the facing member by this attachment to form an image. In the image forming method of forming an image by performing the step of transferring to the body, charging the surface of the image forming body before transferring the toner image to a polarity opposite to the charging polarity of the toner. It is an butterfly. In this direct recording type image forming method, a flying voltage is applied to the flying control electrode to fly the toner from the toner carrier to pass through the through opening of the plate-shaped member, and then the toner image is attached to the facing member to form a toner image. Form.
On the other hand, the surface of the image forming body is charged with a polarity opposite to the charging polarity of the toner to cause a potential difference between the surface and the opposing member. Due to this potential difference, an electric field capable of transferring the toner image on the facing member toward the surface of the image forming body can be formed. With such a configuration, it is not necessary to dispose a transfer bias member on the back surface side of the image forming body and apply a voltage to the transfer bias member, unlike the conventional direct recording method. Then, this eliminates the situation that a high voltage that does not match the actual situation has to be applied to the transfer bias member due to the three-dimensional thickness of the image forming body, and the image is formed on the image forming body. Can be formed. According to a twenty-first aspect of the invention, a step of forming a latent image on the latent image carrier, a step of adhering charged toner to the latent image on the latent image carrier to obtain a toner image, and the toner image being an image-receiving object In the image forming method of forming an image on the image forming body by performing a step of transferring to the forming body, a toner having a polarity opposite to that of the toner is formed on the surface of the image forming body before the toner image is transferred. It is characterized in that solid fine particles or liquid having a charge are attached to charge the surface to the opposite polarity. In this image forming method, a toner image is formed on a latent image bearing member by an electrophotographic method, while the surface of the image forming member is adhered with solid fine particles or liquid having a charge opposite in polarity to that of the toner. Charge to polarity. By charging in this way, when the toner image on the latent image carrier is directly transferred to the image forming body, or when the toner image is transferred to the intermediate transfer body and then indirectly transferred, An electric field capable of transferring the toner image of the transfer source toward the surface of the image forming body can be formed between the (latent image carrier or the intermediate transfer body) and the image forming body. With such a configuration, it is not necessary to dispose a transfer bias member on the back surface side of the image forming body and apply a voltage to the transfer bias member as in the conventional case. Then, this eliminates the situation that a high voltage that does not match the actual situation has to be applied to the transfer bias member due to the three-dimensional thickness of the image forming body, and the image is formed on the image forming body. Can be formed. According to a twenty-second aspect of the present invention, the toner image bearing member that carries the toner image and the image forming member face each other, and the toner image bearing member forms the image forming target on the toner image on the toner image bearing member. In the transfer method of transferring the toner image to the image forming body by applying a transfer electric field that gives an electrostatic force toward the body, the toner is not formed on the surface of the image forming body before the toner image is transferred. By attaching solid fine particles or liquid having a reverse polarity charge,
It is characterized in that the surface is charged to the opposite polarity. In this transfer method, the surface of the image forming object is charged to the opposite polarity by the attachment of solid fine particles or liquid having an opposite charge to the toner prior to the transfer. Even in such a configuration, it is possible to eliminate the situation that a high voltage that does not match the actual situation has to be applied to the transfer bias member due to the three-dimensional thickness of the image forming object, and the image forming object is imaged. Can be formed. According to a twenty-third aspect of the present invention, a toner carrier carrying charged toner, a plurality of flight control electrodes for controlling the flight of the toner from the toner carrier, and a plurality of penetrating holes facing the toner carrier. A plate-shaped member having an opening, the toner flying from the toner carrier by application of a flight voltage to the flight control electrode is caused to pass through the through opening, and the toner after passing is adhered to the image forming body. In the image forming apparatus for forming an image by using the charging means, a charging means for charging the surface of the image forming body before the toner is attached to a polarity opposite to the charging polarity of the toner is provided. In this direct recording type image forming apparatus, for the same reason as in the image forming method of claim 1, the situation in which a high voltage unsuitable for the actual situation has to be applied to the counter electrode or the like is eliminated, and An image can be formed on the image forming body. According to a twenty-fourth aspect of the present invention, a toner carrier carrying charged toner, a plurality of flight control electrodes for controlling the flight of the toner from the toner carrier, and a plurality of penetrating holes facing the toner carrier. A plate-shaped member having an opening, a facing member facing the toner carrier via the plate-shaped member, and a transfer unit for transferring a toner image formed on the facing member to an image forming body,
In an image forming apparatus for forming a toner image by passing the toner flying from the toner carrier through the through opening by applying a flying voltage to the flying control electrode and adhering the toner after passing on the facing member. A charging means for charging the surface of the image forming body before transferring the toner image to a polarity opposite to the charging polarity of the toner is provided. In this image forming method, for the same reason as in the image forming method according to claim 20, the situation in which a high voltage unsuitable for the actual situation has to be applied to the transfer bias member is eliminated, and An image can be formed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an example of a conventional image forming apparatus will be described before describing an image forming apparatus to which the present invention is applied. [First Conventional Example] FIG. 7 is a schematic configuration diagram of a printer according to the first conventional example. This printer forms an image by a direct recording method. In the figure, a plurality of recording papers P, which are image forming bodies, are accommodated in a paper feed cassette 1 in a stacked manner. The recording paper P located at the top is sent to the paper transport path in the printer by the rotation of the paper feed roller 2 which is in contact with the recording paper P. Then, after passing through the transport nip formed by the pair of transport rollers 3, the paper is transferred to the paper transport unit 4.

The paper transport unit 4 is endlessly moved clockwise in the drawing by the rotation of the drive roller 4b while the endless paper transport belt 4a is stretched between the drive roller 4b and the driven roller 4c. Paper transport belt 4a
Passes the recording paper P delivered from the pair of transport rollers 3 toward the fixing unit 5 while passing through the image recording unit 100. The image recording unit 100 includes a yellow recording unit 100Y, a magenta recording unit 100M, a cyan recording unit 100C, and a black recording unit 100Bk. These recording units respectively include a main body portion arranged on the upper side of the paper transport belt 4a in the figure, and a counter roller (104Y, M,
C, Bk) and the color of the toner used is different from yellow, magenta, cyan and black.
The configuration is almost the same. Yellow recording unit 1
In the case of 00Y, for example, the main body provided with the toner containing portion 101Y, the toner carrying roller 102Y as a toner carrying body, the flight control plate 103Y as a plate-like member, and the like is attached to the front surface of the paper transport belt 4a with a predetermined gap. Are facing each other. Further, the opposing roller 104 is provided so that the paper transport belt 4a that can be moved endlessly is interposed between the main body portion and the paper transport belt 4a.
Y is brought into contact with the back surface of the paper transport belt 4a. A counter voltage is applied to the counter roller 104Y as a counter electrode by a voltage applying unit (not shown).

FIG. 8 is an explanatory diagram for explaining the principle of image recording by the yellow recording unit 100Y. In the figure, a flight control plate 103Y, which is a plate-shaped member, has an insulating plate material made of polyimide or the like, a plurality of holes 105Y formed therein, and a donut-shaped flight control electrode 106Y that individually surrounds these holes. There is. In the figure,
For convenience, only one combination of the hole 105Y and the flight control electrode 106Y is shown, but the flight control plate 103Y for 600 [dpi] has 4960 such combinations, for example. On the upper side in the drawing of the flight control plate 103Y having such a configuration, for example, in a state of being grounded, a toner carrying roller 102Y carrying yellow toner (Ty) charged with a negative polarity on its surface has a predetermined gap (50 μm in this example). It is arranged through. When a flight voltage of positive polarity is applied to the flight control electrode 106Y, the toner carrying roller 10
An electric field of a predetermined intensity acts on the yellow toner located at a position facing the flight control electrode 106Y on the 2Y and the yellow toner located in the vicinity thereof. Due to the action of this electric field, the electrostatic force applied to the yellow toner exceeds the adhesive force between the yellow toner and the toner carrying roller 102Y, and the aggregate of the yellow toner has a dot shape, and the toner carrying roller 102Y has a dot shape.
It selectively flies from Y and enters the hole 105Y. Then, the flight control electrode 106Y is attracted by an electric field formed between the flight control electrode 106Y and the facing roller 104Y having a higher potential than the flight control electrode 106Y to continue flight, and passes through the hole 105Y. On the upper side of the opposing roller 104Y in the drawing, there is the endlessly moved paper transport belt 4a and the recording paper P transported to this. The aggregate of yellow toner that has passed through the holes 105Y is attached to the surface of the recording paper P that is transported by the paper transport belt 4a to form a yellow dot image.

FIG. 9 is a plan view of a part of the flight control plate 103Y viewed from the facing roller side. In the figure, the arrow W is
The conveyance direction of the recording paper (not shown) is shown. Each flight control electrode 106Y is formed so as to include a hole 105Y of 80 [μm] inside the inner diameter φ of 100 [μm], and is installed at a pitch (main scanning direction) orthogonal to the W direction. Ph is set according to the resolution of the formed image. The through-hole 105Y and the flight control electrode 10
In combination with 6Y, a line image without missing dots can be formed on the recording paper P in the main scanning direction (horizontal direction in the drawing).
Eight rows are formed in a region of about 2 [mm] in the W direction. An electrically independent lead 107Y for individually guiding a flying voltage is connected to each flight control electrode 106Y, and an HVIC (not shown) is connected to each lead 107Y. With such a configuration, each flight control electrode 1
The flight voltage for 06Y is turned ON / OFF independently of each other, and a yellow toner image including a plurality of yellow dot images is formed on the recording paper P.

In FIG. 7 shown above, the paper transport belt 4
The recording paper P delivered to a first enters the yellow recording unit 100Y, where a yellow toner image is formed. Then, the magenta recording unit 100
The magenta toner image, the cyan toner image, and the black toner image are sequentially recorded on the yellow toner image by sequentially passing through M, the cyan recording unit 100C, and the black recording unit 100Bk. The recording paper P on which a full-color image is formed by such overlapping recording is sent to the fixing unit 5 from the paper transport belt 4a. Then, the full color image is fixed by being sandwiched by the fixing nip formed by the heating roller 5a and the pressure roller 5b.

In the printer of the first conventional example having such a structure, when a three-dimensional object such as a PET bottle is used as the image forming body, the paper conveying belt 4a and each recording unit (100Y, M, C, Bk). And the gap between them is several tens [μm]
However, it is necessary to extend the order to several to several tens [cm]. Then, in order to form an effective electric field between the flight control plate and the facing roller, it is necessary to apply a high voltage that does not match the actual situation to the facing roller. Formation was virtually impossible.

[Second Conventional Example] FIG. 10 is a schematic configuration diagram showing a printer according to the second conventional example. This printer also forms an image by the direct recording method, but the direct recording is not performed on the recording paper P but the intermediate recording belt 6
Apply to a. The surface of the intermediate recording belt 6a on which the full-color image is formed by the direct recording method is sent to the transfer nip where the driving roller 6b and the transfer roller 7 come into contact with each other as the endless movement thereof. In this transfer nip, a transfer electric field is formed between the drive roller 6b and the transfer roller 7 which is a transfer bias member to which a transfer bias is applied by a power source (not shown). On the other hand, the recording paper P accommodated in the paper feed cassette 1 is sent toward the conveying roller pair 3 at a predetermined timing and then toward the transfer nip so as to be superposed on the full-color image on the intermediate recording belt 6a. Sent. At the transfer nip, the full-color image superposed on the recording paper P is transferred from the intermediate recording belt 6a onto the recording paper P under the influence of the electrostatic force applied from the transfer electric field and the nip pressure.

In the printer of the second conventional example having such a configuration, when a three-dimensional object such as a PET bottle is used as the image forming body, it is necessary to devise a conveying mechanism for conveying it to the transfer nip. . For example, the transfer roller 7
In addition to the above, it is an idea to provide a transport unit including a driven roller and a transport belt stretched by both rollers. However, even if such an idea is elaborated,
The gap between the belt drive unit 6 for driving the intermediate recording belt 6a and the transport unit is, for example, several to several tens [c] in order to pass a three-dimensional plastic bottle or the like.
[m]]. Then,
In order to form an effective transfer electric field between the drive roller 6b that drives the intermediate recording belt 6a and the transfer roller (7) of the transport unit, a high voltage that does not match the actual situation is applied to the transfer roller (7). Since it was necessary to apply the voltage, it was practically impossible to form an image on a three-dimensional image forming body.

[Third Conventional Example] FIG. 11 is a schematic structural view showing a printer according to the third conventional example. This printer forms an image by an electrophotographic method.
In the figure, the printer has four sets of toner image forming units for forming images of yellow (Y), magenta (M), cyan (C), and black (Bk) in parallel from the right side in the figure. They are arranged side by side. These toner image forming units have substantially the same configuration except the color of the toner used. Taking a yellow toner image forming unit using yellow toner as an example, the photosensitive drum 200Y, the charging roller 201Y, the developing device 202Y, and the intermediate transfer bias roller 2
03Y, a drum cleaning unit 204Y, a discharge lamp 205Y, and the like. An optical writing unit (not shown) including a light source, a polygon mirror, an f-θ lens, a reflection mirror, and the like irradiates the photosensitive drum of each toner image forming unit with laser light while scanning the same based on image data.
This scanning is performed on the basis of single-color image information obtained by decomposing a full-color image into yellow, magenta, cyan, and black color information.
An electrostatic latent image for a single color of magenta, cyan or black is formed. The yellow electrostatic latent image formed on the photosensitive drum 200Y is developed into a yellow toner image by the developing device 202Y. An intermediate transfer unit 206 is provided on the downstream side of the developing position where the development is performed in the rotation of the photosensitive drum 201Y. This is an intermediate transfer bias roller (203Y, M, C, Bk) for each color, a drive roller 206b, and a secondary transfer backup roller 206.
c, the intermediate transfer belt 206a stretched by the driven roller 206d and the like is moved endlessly in the clockwise direction in the drawing by the rotational driving of the driving roller 206b.

The yellow toner image developed on the photosensitive drum 200Y moves to a contact position with the intermediate transfer belt 206a backed up by the intermediate transfer bias roller 203Y as the drum rotates. Then, while being affected by the intermediate transfer bias applied to the intermediate transfer bias roller 203Y, the intermediate transfer is performed on the intermediate transfer belt 206a. The surface of the photosensitive drum 200Y after the intermediate transfer is discharged by the charge removing lamp 205Y after the transfer residual yellow toner is cleaned by the drum cleaning unit 204Y. Then, the charging roller 20
It is uniformly charged by 1Y and is ready for the next image formation.

Similarly, the photosensitive drums 200M, C,
On Bk, a magenta toner image, a cyan toner image, and a black toner image are formed, respectively, and the intermediate transfer belt 20
6a is sequentially superposed and intermediately transferred. By this superposed transfer, a four-color superposed toner image is formed on the intermediate transfer belt 206a.

On the lower side of the intermediate transfer unit 206 in the drawing,
A paper transport unit 207 is provided, and a fixing unit 208 is provided on the left side of the paper transport unit 207. The paper transport unit 207 moves the paper transport belt 207a stretched around the drive roller 207b, the driven roller 207c, the secondary transfer bias roller 207d, etc., endlessly in the counterclockwise direction in the figure by the rotational drive of the drive roller 207b. The four-color superimposed toner image formed on the intermediate transfer belt 206a moves to a secondary transfer position which is a contact position of the paper transport unit 207 with the paper transport belt 207a. On the other hand, a registration roller pair 209 is arranged on the right side of the paper transport unit 207 in the figure, and by this,
The recording paper P, which is an image forming body, is sent to the secondary transfer position at a timing at which it can be superimposed on the four-color superimposed toner image on the intermediate transfer belt 206a.

A secondary transfer bias roller 207d of the paper carrying unit 207 is applied with a secondary transfer bias by a power source (not shown). At the secondary transfer position, the secondary transfer electric field is formed by the potential difference between the secondary transfer bias roller 207d to which the secondary transfer bias is applied in this way and the secondary transfer backup roller 206c of the intermediate transfer unit 206. . The four-color superimposed toner image on the intermediate transfer belt 206a is secondarily transferred onto the recording paper P under the influence of the secondary transfer electric field and the nip pressure, and then sent to the fixing unit 208 to be transferred onto the recording paper P. Fixed in.

In the printer of the third conventional example having such a structure, when a three-dimensional object such as a PET bottle is used as the image forming body, the intermediate transfer unit 206 and the paper conveying unit 207 are not brought into contact with each other. It is necessary to dispose at intervals of, for example, several to several tens [cm] so that a plastic bottle or the like can pass through. Then, in order to form a secondary transfer electric field of effective strength between the secondary transfer backup roller 206c and the secondary transfer bias roller 207d serving as a transfer bias member, a high voltage that does not match the actual situation is applied to the secondary transfer bias roller 207d. Since it has to be applied to 207d, it is practically impossible to form an image on a three-dimensional image forming body.

In the third conventional example, a tandem type printer having four photosensitive drums for each color as the latent image carrier has been described, but four photosensitive drums for each color are provided around one photosensitive drum. There is also known an image forming apparatus having a developing device, in which an electrostatic latent image for each color is individually formed on a photosensitive drum and is developed by any one of the developing devices. Even in such an image forming apparatus, it is practically impossible to form an image on a three-dimensional image forming object for the same reason as in the printer of the third conventional example.

Next, a printer of each embodiment will be described as an image forming apparatus to which the present invention is applied. [First Embodiment] FIG. 1 is a block diagram showing a main part of a printer according to the first embodiment. This printer forms an image by a direct recording method, and has a configuration similar to that of the printer according to the first conventional example and has a black recording unit 10.
It has 0Bk. However, this black recording unit 100
Bk is not provided with a counter electrode such as a counter roller. Toner carrying roller 10 for black recording portion 100Bk
2Bk is a common type used in electrophotography and direct recording, and has a rubber layer of medium resistance of 5 m on a metal core.
m] with a total thickness of 30 [mm]
It has become a degree. The black toner (Tk) is also a general one, for example, particles having a diameter of about 7 [μm] in which a black dye or pigment is dispersed in a matrix of an acrylic resin or a polyester resin. The layer of black toner Bk carried on the toner carrying roller 102Bk is
It is triboelectrically charged by a doctor blade (not shown), and is regulated to have a layer thickness of 2 to 3 layers, and then conveyed to a position facing the flight control plate 103Bk.

On the lower side of the flight control plate 103Bk in the figure, a plastic bottle Bp as an image forming body is supported by a bottle holder (not shown) in a state of being laid down so that its longitudinal direction is located in the depth direction in the figure. Has been done. This bottle holder can rotate the PET bottle Bp having a diameter of 100 [mm] which it supports in a counterclockwise direction in the figure by a rotation mechanism (not shown). Around the PET bottle Bp, in addition to the flight control plate 103Bk, a needle electrode 8, a plate electrode 9, a droplet ejecting unit 10, a heating device 11, etc. are arranged.

The needle-shaped electrode 8 is 10 in the depth direction in the figure.
A plurality of them are arranged at a pitch of [mm], and a +4 [kV] power source is connected to these via a switch (not shown). The plate-shaped electrode 9 is set to have a length in the depth direction in the drawing so as to be able to face all of the plurality of needle-shaped electrodes 8 and is grounded via an electric wire (not shown). When power is supplied to each needle-shaped electrode 8, corona discharge is generated from the vicinity of their tips, and the positive corona ions generated therein are formed between the tip of each needle-shaped electrode 8 and the plate-shaped electrode 9. Electric field E
And moves toward the plate-shaped electrode 9 along the direction. The liquid droplet jetting unit 10 is a solution prepared by dispersing a film-forming resin such as polyvinyl alcohol, cellulose diacetate, cellulose triacetate, vinyl acetate, poval, polyethylene glycol, polyurethane, or nylon into a solvent. It is possible to spray in a shape having a width in the depth direction in the figure. This spray produces a radius of 1 [μ
A group of microdroplets 12 of about [m] pass through between the plurality of needle-shaped electrodes 8 and the plate-shaped electrode 9 and adhere to the PET bottle Bp. In the middle of the process, the positive corona ions moving from each needle-shaped electrode 8 toward the plate-shaped electrode 9 are made to adhere and are charged with a positive charge. That is, the microdroplets 12 are charged with positive polarity prior to being attached to the PET bottle Bp.
Even if charged in this way, the ejection pressure from the droplet ejection unit 10 is sufficiently strong, and therefore reaches the PET bottle Bp before being attracted to and attached to the plate electrode 9 side. Then, a solution layer having a thickness of 2 [μm] is formed on the PET bottle Bp, and the bottle surface is positively charged.

On the other hand, when a positive flight voltage is applied to the flight control electrode 106Bk of the flight control plate 103Bk, the grounded toner carrier roller 102Bk and the flight control electrode 1 are grounded.
An electric field is formed between this and 06Bk. The black (Tk) aggregate at the position facing the flight control electrode 106Bk on the toner carrying roller 102Bk is negatively charged, and is affected by this electric field to fly in a dot shape, and a part of the fly. It enters into the hole 105Bk of the flight control plate 103Bk. Hole 105Bk and positively charged PET bottle B
An electric field is formed between the surface of p and the surface of p. The direction of this electric field causes the negative black toner (Bk) to pass through the holes 105.
When the direction is such that an electrostatic force that moves from inside Bk to the PET bottle Bp side is applied, the aggregate of black toner (Tk) within the hole 105Bk continues to fly toward the PET bottle Bp. Then, after flying in a space of about 1 to 10 [mm] between the flight control electrode 106Bk and the plastic bottle Bp, it adheres to the surface of the plastic bottle Bp to form a black dot image.

The black toner image composed of a plurality of black dot images formed on the surface of the PET bottle Bp in this way is heated by the heating device 11 as the PET bottle Bp rotates.
It is heated when passing through the opposite position. Then, by this heating, it is fixed on the surface of the plastic bottle Bp.

By the way, the amount of charge generated on particles by corona discharge is shown in FIG. 2 (new edition electrostatic handbook).
It can be calculated based on the graph shown in p1047, edited by Japan Society of Static Electricity. In the printer of the first embodiment, as described above, the droplet ejecting unit 10 ejects the minute droplets 12 having a radius of 1 [μm]. Therefore, when the charge amount Q of the particles having a radius of 1 [μm] is specified from the collision charge graph of FIG. 2, the following equation is obtained.

## EQU1 ## Q = ^5-17 [C]

The mass of particles can be determined by the following equation.

## EQU2 ## m = (4/3) × π × r3 × ρ [kg] However, r and ρ indicate radius and specific gravity, respectively.

Here, the specific gravity of the solution was 1.0. Therefore, the amount of charge per unit mass is given by the following equation.

## EQU3 ## Q / m = (1.194) ^-2 [C / kg]

Thickness 2 formed on the PET bottle Bp
The unit area S (1 m ^Two) Mass M
Is as follows:

## EQU4 ## M = S × t × ρ = 2 ⁻³ [kg] where t represents the thickness of the solution layer.

Therefore, the amount of charge q per unit area S of the solution layer is given by the following equation.

Q = Q / m × M = (1.194) ⁻² / 2 ⁻³ = (2.388) ⁻⁵ [C / m ² ]

The above-mentioned solution layer having such an electric charge amount q has a hole 105B as the PET bottle Bp rotates in FIG.
When located below k, an electric field is formed between the flight control electrode 106Bk and the solution layer. At this time, the ring width of the flight control electrode 106Bk is 20 [μm], but the width of the solution layer is much larger than this, so that the lines of electric force in this electric field are not parallel to the vertical direction. However, let us assume that the capacitor model has a sufficiently wide ring width. Then, the following three formulas hold there.

[Equation 6] E = V / d [V / m] However, V and d represent a potential and a distance, respectively.

(7) V = qS / C [V]

C = ε _r ε ₀ / d [C ² / N · m] where ε _r and ε ₀ represent the relative permittivity of air and the permittivity of vacuum, respectively.

Using the equations obtained by substituting the equations (7) and (8) into the equation (6), the following equation is obtained when ε _{r is set} to 1.0000.

E = q / ε _r ε ₀ = q / (1.0000 × ε ₀ ) = q / ε ₀ = (2.7) ⁶ [V / m]

In the conventional direct recording system, the electric field strength E between the flight control electrode and the image formed body is set to ^{26 to} 3.
^It was set to ⁶ [V / m]. Therefore, even if a counter electrode such as a counter roller is not provided, the microdroplets 12 are charged to Q / m = (1.194) ⁻² [C / kg] by collision with positive corona ions, and the minute liquid droplets 12 of the image forming body are charged. If it is adhered to the surface with a thickness of 2 [μm], an electric field having the same strength as in the conventional direct recording system can be formed between the flight control electrode and the image forming body.

The present inventor actually made a prototype of the apparatus shown in FIG. 1 and conducted a recording test. Specifically, about −10 [μ
C / g] is used to charge the black toner (Tk),
A flight voltage of +300 [V] was applied to the flight control electrode 106Bk. Then, a black toner image could be formed on the PET bottle Bp. The flight control electrode 106B corresponding to the area where the black dot image is not formed
A flight suppression voltage of −50 [V] was applied to k.

When the flying state of the black toner was photographed by a high speed camera, it was found that it reached the plastic bottle Bp at a speed of 1 to 3 [m / sec].
Therefore, if an electric field having the same strength as that of the conventional direct recording method is formed between the flight control electrode 106Bk and the surface of the image forming body, the direct recording method can be realized without providing a counter electrode such as a counter roller. It was proved. In this embodiment although the electric field intensity and ^{(2.7) 6 [V / m} ], if the least conventional were lower ² 6 [V / m], holes 105
It is believed that the toner that has entered into Y can be reliably continued to fly toward the image forming body.

As described above, in this example, the black toner reaches the plastic bottle Bp at a speed of 1 to 3 [m / sec]. In the conventional direct recording method, when the toner reaches the image forming body such as a recording paper at such a speed, the toner having high elasticity spreads in the surface direction while bouncing many times on the image forming body. , A very blurred dot image lacking sharpness was formed. However, in this example, it was found that the solution layer on the PET bottle Bp functions as a cushion and the black toner stops on the bottle without rebounding. Therefore, a dot image with a small diameter and excellent sharpness was formed, and an image with excellent resolution was formed. The cushioning function of the solution layer varies depending on its viscosity and thickness, but it is expected that the rebound of the toner can be expected to be reduced if it is at least 1 [μm] or more.

The black toner image directly recorded on the surface of the PET bottle Bp is heated by the heating device 1 as the bottle rotates.
It passes the position opposite to 1. At this time, it was confirmed that the solution layer on the bottle surface was irradiated with infrared rays from the heating device 11 to evaporate the solvent, and at the same time, the resin film layer was formed by the resin component which was deposited so as to cover the black toner image. When the PET bottle Bp was removed from the bottle holder and a black toner image was confirmed, it was confirmed that this film layer exhibited high-definition gloss and was firmly fixed to the bottle surface. Therefore, as the resin of the solution used for the droplet jetting unit 10, a curable resin or a plastic resin capable of forming such a resin film layer is desirable. Regarding the heating device 11, a heating system other than infrared rays, an ultraviolet irradiation means without heating, a gas injection means, a curing agent application means, a plasticizer is used according to the principle of the curing reaction or plastic reaction of the resin in the solution. It may be replaced with a coating means or the like. For example, when a solution containing an ultraviolet curable resin is used, the heating device 11 may be replaced with an ultraviolet irradiation device.

When a curable resin or a plastic resin which initiates curing or plasticization when mixed with a curing agent or a plasticizer is used, if a toner containing the curing agent or the plasticizer is used,
The resin film layer can be formed without providing the heating device 11 or its alternative means. As the plasticizer and the curing agent, a polymerization initiator, a cross-linking initiator and the like can be considered.

Although the printer shown in FIG. 1 can only form an image of a single color of yellow, the color recording units (100Y, M, 100Y, M, A full-color image can be formed by sequentially moving the same as C and Bk) to the portion facing the bottle. Further, the surface of the plastic bottle Bp may be directly charged by frictional charging or the like, instead of charging the surface of the PET bottle Bp by attaching a charged substance such as the above solution.

Next, the printer of each example in which a more characteristic configuration is added to the printer of the first embodiment will be described. [Example 1] A powder ejection unit was attached instead of the droplet ejection unit 10. Then, powder consisting of solid fine particles of high molecular weight polyethylene glycol having an average particle diameter of 10 [μm] was set in the powder injection unit.
This polyethylene glycol powder is solid at room temperature, but melts at high temperature to form a resin film layer.

When an image was formed using the printer of Example 1 having the above-mentioned structure, a black toner image exhibiting high-definition gloss could be formed by the polyethylene glycol resin film layer. Moreover, this black toner image was fixed to the bottle surface more firmly than the black toner image of the first embodiment. This is probably because polyethylene glycol, which is easily compatible with polyethylene terephthalate, which is the material for PET bottles Bp, was more firmly adhered to the bottle surface. Therefore, if the same curable resin powder, plastic resin powder, or solution containing any of these as the material of the image-formed body is used, the resin film layer is extremely strongly adhered to the surface of the image-formed body (or By fixing the toner image, the toner image can be fixed extremely firmly. Further, the image-formed body can be recycled and used as a high-purity material without the trouble of peeling the label on which the image is printed from the image-formed body such as a PET bottle.

In the printer of the first embodiment, the first charged material to be attached to the PET bottle Bp which is the image forming body is the first.
Instead of using a solution like the printer of the embodiment,
Since the solid powder is used, environmental pollution due to evaporation of the solvent in the solution can be eliminated. Further, it is not necessary to additionally install a solvent recovery mechanism for suppressing such environmental pollution. Further, even a substance that is difficult to dissolve can be easily used. For example, when a glass-made material is used as the image forming body, it is desirable to adhere glass powder, which is difficult to dissolve as a charged substance, to the image forming body in order to strengthen the fixation of the toner image. In such a case, it is very effective. However, when solid powder is used, it may be scattered, so it is necessary to consider the setting of the air flow in the device. Further, the powder layer formed on the surface of the bottle due to the adhesion of the solid powder reduces the bounce of the yellow toner flying from the toner carrying roller 102Y, but like the solution layer formed by the printer of the first embodiment. It cannot be completely eliminated.

On the other hand, in the printer of the first embodiment in which the solution is used as the charging substance to be attached to the PET bottle Bp, the toner layer on the bottle surface is formed by forming the solution layer on the bottle surface instead of the powder layer of solid fine particles. It is possible to eliminate the bounce and form a dot image with excellent sharpness. In addition, it is possible to eliminate the need for measures to reduce the scattering of solid powder.

In the first embodiment and the first embodiment described above, an example in which a solution that is a liquid or a powder that is solid fine particles is charged by corona discharge has been described. It can be charged to a higher level, and the amount of charge can be stabilized more than triboelectric charging regardless of solid-liquid.

[Example 2] In the printer of the first embodiment, as the liquid to be sprayed on the PET bottle, a solution in which a soluble resin is dissolved in a solvent, such as an alcohol solution in which polyethylene glycol is dissolved, is used. In addition, as shown in FIG.
0) in place of the continuous ink jet ink head 14, and the needle-shaped electrode (8),
A ring-shaped electrode 15 was arranged instead of the plate-shaped electrode (9). Then, the minute liquid droplets 12 were ejected from the ink head 14 while applying a voltage of −1 [kV] to the ring-shaped electrode 15. As a result, the microdroplets 12 were positively charged and then attached to the PET bottle Bp, whereby a high-concentration and high-definition black toner image could be formed on the charged bottle surface. On the surface of the bed bottle Bp heated by the heating device 11, a resin that spread thinly and dried adhered to cover the black toner image, assisted in fixing the image, and exhibited gloss.

The minute liquid 12 ejected from the ink head 14 is positively charged because a positive charge as shown in the figure is induced at the tip of the liquid column protruding from the ink head 14, and the tip of the liquid column is interrupted. This is because the positive charges of the minute liquid droplets 12 are trapped in the liquid droplets. Such a phenomenon is well known as induction charging and is actually used in an image forming method using a continuous inkjet.

In the printer having the above structure, the surface of the PET bottle Bp can be charged with a stable amount of electric charge having a polarity opposite to that of the toner without generating ozone due to corona discharge. In addition, the soluble resin can be fixed to the surface of the PET bottle Bp to assist in fixing the toner image and improve the gloss thereof.

When a similar image was formed using only a solvent (water or alcohol) without dissolving the soluble resin, the surface of the PET bottle Bp was charged in the same manner to obtain a high density and high definition black toner image. Could be formed. However, since fixing of the toner image is not assisted by fixing the soluble resin, the fixing degree and gloss of the toner image are lowered.

When a similar image was formed using a solvent in which a white dye or pigment was dissolved, the background of the black toner image was changed to white and the visibility of the image could be improved.

[Embodiment 3] In the printer of the first embodiment, the jet unit heating means for heating the droplet jet unit 10 to 100 [° C.] is provided, while the heating device 11 for heating the PET bottle Bp is provided. I removed it. Then, a low molecular weight polyethylene glycol resin was used instead of the solution in which the resin was dispersed. Low molecular weight polyethylene glycol is solid at room temperature,
At [° C], it becomes a liquid with low viscosity. When ejected from the droplet ejecting unit 10, the minute droplets 12 of the liquid were charged to the positive polarity by the corona ions and then adhered to the PET bottle Bp in the same manner as the minute droplets of the solution. And
The bottle surface was positively charged, and a high-concentration and high-definition black toner image was formed. This black toner image was fixed by polyethylene glycol fixed on the bottle surface.

In this structure, the PET bottle Bp
Since the toner image can be fixed without heating the toner adhered on it by the heating means for fixing, the deformation of the PET bottle Bp due to the heating for fixing can be suppressed.

[Embodiment 4] The needle electrode 8, the plate electrode 9, and the liquid droplet ejecting unit 10 of the printer of the first embodiment.
Respectively, and instead, as shown in FIG. 4, corona discharge electrode 14, first proximity electrode 15, second proximity electrode 16
Was arranged. The first proximity electrode 15 and the second proximity electrode 16 are
The corona discharge electrodes 14 are arranged so as to be positioned in the vicinity of the surface of the PET bottle Bp while maintaining a predetermined gap therebetween, and the corona discharge electrode 14 is arranged on an extension line passing from the surface of the bottle to both electrodes. The corona discharge electrode 14 is oriented so that its sharp tip is oriented perpendicularly to the surface of the PET bottle Bp. In addition, the first proximity electrode 15 and the second proximity electrode 16
Are each grounded. In such an electrode configuration, most of the corona ions generated near the tip of the corona discharge electrode 14 move toward the grounded first proximity electrode 15 and second proximity electrode 16 and flow from these electrodes to the ground. . However, some corona ions move along the lines of electric force formed so as to swell between the first proximity electrode 15 and the second proximity electrode as shown in FIG. 4, and reach the bottle surface. Then, the bottle surface is positively charged.
The aggregate of yellow toners, which has flown from the toner carrying roller 102Y and has entered the hole 102Y, continues to fly toward the surface of the bottle thus charged to form a dot image.

In the printer having the above structure, the liquid drop ejecting unit (10), the powder ejecting unit, etc. are not required, and the solution and solid powder are not required. In addition, it is possible to save space. However, since the solution layer or the powder layer is not formed on the bottle surface, it is impossible to suppress the bound of the toner on the bottle surface by these.

It is known that the toner bounce becomes remarkable when the speed at which the toner reaches the image forming body is 1.0 [m / sec] or more. Therefore, if it is possible to reduce the image forming speed to a certain extent (leading to a decrease in productivity) if high image quality is obtained, slow the toner flying speed to a certain extent, and adjust the bottle speed accordingly. By lowering the rotation speed of, the image quality deterioration due to the bound of the toner can be suppressed.

[Embodiment 5] In the printer of the first embodiment described above, a black toner having a positive charging property was set instead of the black toner having a negative charging property. In addition, the needle-shaped electrode 8 and the plate-shaped electrode 9 are placed in the liquid droplet ejecting unit 10 as a unit.
It was arranged with a gap of [mm], and the solution was positioned between them. Then, the needle electrode 8 has -1000.
When a voltage of [V] was applied, the droplet ejection unit 10
The solution located between the inner electrodes was negatively charged.
This phenomenon is known as charge injection into liquids. The charge injection does not work well if the electric resistance of the liquid is too high or too low, but is well realized if it is approximately 10 ¹⁰ [Ωcm]. Further, even with an insulating liquid, if a higher voltage such as −10 [kV] is applied to the needle-shaped electrode 8, corona discharge in the minute voids (fine bubbles) existing in the liquid or needle-shaped It is also possible to cause corona discharge by minute voids (air bubbles) existing in a solution that emits electrons from the electrode 8 or to directly emit electrons from the needle electrode. Regarding the electrical resistance of liquids, ionized substances in water (ionic substances) such as sodium chloride
You may adjust by the addition amount of.

+300 to the flight control electrode 106Bk
An image was formed on a PET bottle Bp whose surface was negatively charged by the adhesion of the microdroplets 12 while applying a flight voltage of [V] or a flight suppression voltage of +50 [V]. Then, it was possible to form a black toner image with high density and high definition and gloss.

In such a structure, the surface of the PET bottle Bp can be charged with a stable electric charge having a polarity opposite to that of the toner, without causing a situation in which a large amount of ozone is generated by excessive corona discharge.

[Embodiment 6] In the printer of the first embodiment, the minute droplets 12 are sprayed over almost the entire surface of the PET bottle Bp, but the ejection tip width of the droplet ejection unit 10 is used as image information. It was made possible to adjust the spray width by making it variable based on the above. Then, based on the image information, for example, a label is sprayed only on a predetermined region in which an image of 10 [cm] × 5 [cm] is included. As described above, even if the microdroplets 12 are attached only to the predetermined area in which the image is included, the same high image quality as that of the first embodiment can be reproduced.

In this structure, the plastic bottle Bp
On the other hand, it is possible to suppress the wasteful consumption of the solution due to the adhesion of the microdroplets 12 to the region where no image is formed. The image formed on the plastic bottle Bp is not a circular or polygonal solid image but a complicated shape such as characters and symbols. Therefore, 10 [cm] x 5
Even if the microdroplets 12 are attached only to a standard area including an image such as [cm], the area in which a toner image is actually formed becomes smaller. In other areas, measures such as electric field formation and reduction of toner bounce are not so important, and it may be sufficient to achieve other purposes such as improving glossiness and adding background color. is there. In such cases,
If the minute liquid droplets 12 are sprayed on the rotating PET bottle Bp based on the image information while continuously changing the ejection width, wasteful consumption of the solution can be further suppressed. Furthermore, if the voltage application to the needle-shaped electrode 8 which does not correspond to the toner image forming region is turned off,
Useless energy consumption can also be suppressed.

[Embodiment 7] The above-described first embodiment and embodiment 1
In this printer, a thermoplastic resin was used as the resin to be dispersed in the solution or as the solid fine particles. Further, the position of the heating device 11 is moved so as to heat the solution layer composed of the minute droplets 12 and the powder layer composed of the solid fine particles adhered to the surface of the PET bottle Bp prior to the toner adhesion from the holes 105Bk. did. Then, when a black toner image was formed, each dot image was formed with a smaller diameter, and the sharpness of the edge of the image could be further improved. This is because the resin that has become highly viscous due to softening due to heating and the solution that has become highly viscous as the resin becomes highly viscous have enhanced cushioning properties when the toner lands.

[Embodiment 8] A solution or solid fine particles (powder) is contained in the PET bottle Bp after the black toner image is formed.
There is a case where electric charge remains due to the influence of. This residual charge may attract dust or the like floating in the air to generate dirt. Therefore, in the printer of the first embodiment, a corona charger, which is a static eliminator, is arranged on the downstream side of the heating device 11 in the bottle rotation direction, and when the static neutralizer is tried to discharge by AC corona discharge, the plastic bottle Bp
It was possible to eliminate the residual charge of.

In this structure, the plastic bottle Bp
Contamination due to the residual electric charge of can be suppressed.

[Second Embodiment] FIG. 5 is a schematic structural view showing a printer according to the second embodiment. This printer also forms an image by the direct recording method. The steps until the full-color toner image is recorded on the intermediate recording belt 6a are the same as those in the printer of the second conventional example.
However, since this printer uses the PET bottle Bp as the image forming body instead of the recording paper, it does not include a paper feed cassette or a fixing unit. Instead, a bottle holder that presses the bet bottle Bp toward the intermediate recording belt 6a while rotatably supporting it, a needle-shaped electrode 8, a plate-shaped electrode 9, and a liquid droplet ejecting unit 10 similar to those in the printer of the first embodiment,
A heating device 11 is provided.

The full-color toner image recorded on the intermediate recording belt 6a is transferred onto the bottle surface by the action of the transfer electric field formed at the contact position between the belt and the PET bottle Bp. However, this transfer electric field is not formed by the transfer bias member such as the transfer roller (7) of the second conventional example, but is formed by the charge of the solution layer formed on the bottle surface. Due to the influence of the transfer electric field, the full-color toner image is transferred to the surface of the bed bottle Bp. The above bottle holder is a plastic bottle B
When the image forming target area of p passes through the contact position with the intermediate recording belt 6a, the plastic bottle B
Move p to a position where it is separated from the belt. On the other hand, the solution and residual toner adhering to the surface of the intermediate recording belt 6a after passing the contact position is cleaned by the belt cleaning unit 13.

In the printer of the above construction, the transfer roller (7) which is a transfer bias member is arranged on the back side of the recording paper P which is the image forming body, and a voltage is applied to the transfer roller (7). Even if such a configuration is not adopted, a transfer electric field having a desired strength can be formed between the flight control plate that is the facing member and the surface of the PET bottle Bp that is the image forming body. By this, three-dimensional plastic bottle Bp
It is possible to form a full-color image on the PET bottle Bp by eliminating the situation in which a high voltage unsuitable for the actual situation has to be applied to the transfer bias member due to the thickness of the.

[Third Embodiment] FIG. 6 is a schematic structural view showing a printer according to the third embodiment. This printer forms an image by an electrophotographic method. The steps until the four-color superimposed toner image is formed on the intermediate transfer belt 206a are the same as those in the printer of the third conventional example.
However, since the printer uses the PET bottle Bp as the image forming body instead of the recording paper, the paper transport unit (2
07) and the fixing unit (208). Instead, a bottle holder that presses the bet bottle Bp toward the intermediate transfer belt 207a while supporting the bed bottle Bp,
The printer has the same needle-shaped electrode 8, plate-shaped electrode 9, droplet ejecting unit 10, and heating device 11 as those of the printer of the first embodiment.

The full-color toner image formed on the intermediate transfer belt 206a by the superimposed transfer from the photoconductor drums 200Y, M, C and Bk is the secondary transfer formed at the contact position between the belt and the PET bottle Bp. Secondary transfer is performed on the bottle surface by the action of the electric field. However, this secondary transfer electric field is not formed by the transfer bias member such as the secondary transfer bias roller (207d) of the third conventional example, but is formed by the charge of the solution layer formed on the bottle surface. It Due to the influence of the secondary transfer electric field, the full-color toner image is secondarily transferred onto the surface of the bed bottle Bp. In the bottle holder, the image forming target area of the PET bottle Bp is the intermediate point transfer belt 206.
In consideration of the timing of passing the contact position with a, the plastic bottle Bp is moved to a position where it is separated from the belt. On the other hand, the solution and residual toner adhering to the surface of the intermediate transfer belt 206a after passing the contact position are cleaned by the belt cleaning unit 13.

In the present printer having the above-described structure, like the printer of the third conventional example, a transfer bias member such as a secondary transfer bias roller is provided on the back side of the image forming body such as the recording paper P. However, a secondary transfer electric field having a desired intensity can be formed between the intermediate transfer belt 206a and the surface of the image forming body without applying a voltage thereto. Then, this eliminates the situation that a high voltage that does not match the actual situation has to be applied to the transfer bias member due to the three-dimensional thickness of the PET bottle Bp, and the PET bottle that is the image forming body is eliminated. A full color image can be formed on Bp.

Although the tandem type printer has been described in the third embodiment, four photoconductors for each color are provided around one photoconductor drum, and a static image printer for each color is provided on the photoconductor drum. The present invention can also be applied to an image forming apparatus of a type in which an electrostatic latent image is individually formed and developed by any of the developing devices. Further, an electrophotographic image forming apparatus in which a belt-shaped member such as a photosensitive belt is used as a latent image carrier, and a toner image formed on the latent image carrier is transferred to the bottle surface without intermediate transfer is also provided. Applicable.

In the printers of the above-described respective embodiments and examples, the following advantageous effects can be obtained. That is, the plastic bottle Bp which is the image forming body
In the printers of the first embodiment and the respective examples in which the toner image is directly recorded on the image forming body, the counter electrode is arranged on the back surface side of the image forming body, and the counter voltage is applied thereto. It is possible to form an electric field having a desired intensity between the hole 105Bk, which is a through opening, and the surface of the image forming body without performing the process. As a result, it is possible to eliminate a situation in which a high voltage that does not match the actual situation has to be applied to the counter electrode due to the thickness of the three-dimensional plastic bottle Bp, and an image can be formed on the bottle surface. .
Further, in the printer of the first embodiment, Example 2, 3, 5 or 6, in which the surface of the PET bottle Bp is charged by the adhesion of the minute droplets 12 having the opposite polarity to the toner,
The liquid layer on the surface of the bottle can suppress the rebound of the toner and can form a dot image having a small diameter and excellent sharpness. Moreover, since the solid fine particles used in the printer of the first embodiment are not used, it is possible to eliminate the need for measures for reducing the scattering. Further, in the printer of Example 1 in which the surface of the PET bottle Bp is charged by the adhesion of solid fine particles having a polarity opposite to that of the toner, since the solution as in the first embodiment is not used, the solvent in the solution evaporates. Environmental pollution can be eliminated. Moreover, although it is inferior to the case of using the solution, the powder layer on the bottle surface can suppress the rebound of the toner and form a dot image having a small diameter and excellent sharpness. Further, in the printer of Example 4 in which the surface of the PET bottle Bp before the toner is attached is charged by corona discharge, the above-mentioned droplet jetting unit (10), powder jetting unit, etc. are not required and neither solution nor solid powder is required. Therefore, it is possible to eliminate the cost increase due to the use thereof and to save the space. Further, in the printer of the second embodiment which uses a solution in which a soluble resin is dissolved in a solvent, the soluble resin is fixed to the surface of the PET bottle Bp to assist the fixing of the toner image and improve its gloss. You can Further, in the printer of Example 3 in which a liquid that becomes a solid at room temperature is liquefied as the liquid to be sprayed on the bottle surface, the toner adhered to the bottle surface may be heated by the heating means for fixing the toner. Since the image can be fixed, the deformation of the PET bottle Bp due to the heating for fixing can be suppressed. Further, in the printer of the first embodiment or each of the examples, when a curable resin or a plastic resin is used as the resin in the liquid to be attached to the PET bottle Bp or the solid fine particles, a resin film layer is formed on the bottle surface. It is possible to exhibit high-definition gloss and firmly fix the toner image on the bottle surface. If a toner containing a curing agent of the above-mentioned curable resin or a plasticizer of the above-mentioned plastic resin is used as the toner, the resin film layer can be formed without providing the heating device 11 or a means for replacing it. Further, when the curable resin or the plastic resin made of polyethylene terephthalate, which is the same material as the PET bottle Bp, is used, the toner image is more firmly adhered to the bottle surface by the stronger adhesion of the resin film layer to the bottle surface. Can be fixed. Moreover, the PET bottle Bp can be recycled and used as a high-purity polyethylene material without the trouble of peeling the label on which the image is printed from the PET bottle Bp. Further, in the printer of the first embodiment in which electric charge is applied to a solution (liquid) by corona discharge, the solution can be easily charged, and the amount of charge can be stabilized more than that by frictional charging. . In addition, in the printer of the fifth embodiment in which the charge is applied to the solution by the charge injection,
It is possible to charge the surface of the PET bottle Bp with a stable electric charge having a polarity opposite to that of the toner without causing a situation in which a large amount of ozone is generated due to excessive corona discharge. Further, in the printer of the first embodiment and each of the examples (excluding the fourth example), if solid fine particles or liquid is charged by friction, electric energy for corona discharge and charge injection is not consumed. The bottle surface can be charged. Further, in the printer of Example 2 in which the solution is charged by electrostatic induction, the bottle surface can be charged with a stable charge amount without generating ozone due to corona discharge. Further, in the printer of Example 2 in which an opaque white solution is used as the solution, the background of the toner image can be colored to improve the visibility of the image. Further, in the printer using the solution, such as the first embodiment, if the solution is made to adhere to the bottle surface with a thickness of 1 [μm] or more, it is expected to reduce the rebound of the toner when the bottle surface lands. You can In addition, in the printers of the first embodiment and the respective examples, 2 ⁶ [V / m is provided between the flight control electrode 106Bk to which the flight voltage is applied and the surface of the bottle charged by the adhesion of the solid fine particles or the minute droplets 12. ]
By forming the electric field having the above strength, it is possible to reliably continue the flight of the toner after entering the hole 105Bk toward the bottle surface. Therefore, direct recording can be surely realized. Further, in the printer of the sixth embodiment in which the microdroplets 12 are sprayed onto the bottle surface only in a predetermined area capable of containing an image to be formed, it is wasteful to attach the microdroplets to the area where no image is formed. The consumption of various solutions can be suppressed. In addition, the resin in the solution or the curable resin or the plastic resin as the solid fine particles is used, and the bottle surface is heated before the toner is attached onto the solution layer or the powder layer attached to the bottle surface. In the printer, the cushioning property at the time of landing of the toner is further enhanced by the resin whose viscosity is increased by softening due to heating and the solution whose viscosity is increased by increasing the viscosity of the resin. Then, by this, each dot image can be formed to have a smaller diameter, and the sharpness of the edge of the image can be further improved. Further, in the printer of the eighth embodiment, which removes the electric charge from the PET bottle Bp after the image formation, it is possible to suppress the stain due to the residual charge of the PET bottle Bp. Further, in the printer of the second embodiment which transfers the toner image formed on the intermediate recording belt 6a, which is a facing member, to the PET bottle Bp by the direct recording method, the transfer bias member is provided on the back surface side of the image forming body. However, it is possible to form a transfer electric field having a desired intensity between the belt and the surface of the image forming body without performing a voltage application thereto. As a result, even if the image-formed body is a three-dimensional plastic bottle Bp, it is possible to eliminate a situation in which a high voltage unsuitable for the actual situation has to be applied to the transfer bias member due to its thickness. , An image can be formed on the bottle surface. Further, the intermediate transfer belt 206, which is a transfer source, transfers the toner image formed by the electrophotographic method.
In the printer of the third embodiment for transferring from a to the plastic bottle Bp, the transfer source is provided even if the transfer bias member is provided on the back side of the image forming body and a voltage is not applied to the transfer bias member. A transfer electric field having a desired strength can be formed between the surface of the image forming body and the surface of the image forming body. And
As a result, even if the image-formed body is a three-dimensional plastic bottle Bp, it is possible to apply a high voltage unsuitable to the actual situation to the transfer bias member due to its thickness. , An image can be formed on the bottle surface.

[0072]

The effects of the present invention are set forth in claims 1, 2, 3, 4, 5, 6, 7.
8, 9, 10, 11, 12, 13, 14, 15, 16,
According to the invention of 17, 18, 19, 20, 21, 22, 23, or 24, it is possible to eliminate the situation in which a high voltage that does not match the actual situation has to be applied to the counter electrode, the transfer bias member, or the like. There is an excellent effect that an image can be formed on the image forming body.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a main part of a printer according to a first embodiment.

FIG. 2 is a graph showing the relationship between the radius of particles charged by corona discharge and the amount of charge.

FIG. 3 is a configuration diagram showing an ink head of a printer according to a second embodiment.

FIG. 4 is a configuration diagram showing a corona discharge electrode and the like of a printer according to a fourth embodiment together with a plastic bottle.

FIG. 5 is a schematic configuration diagram showing a printer according to a second embodiment.

FIG. 6 is a schematic configuration diagram showing a printer according to a third embodiment.

FIG. 7 is a schematic configuration diagram of a printer according to a first conventional example.

FIG. 8 is an explanatory diagram for explaining the principle of image recording by the yellow recording unit.

FIG. 9 is a plan view of a part of the flight control plate viewed from the facing roller side.

FIG. 10 is a schematic configuration diagram showing a printer according to a second conventional example.

FIG. 11 is a schematic configuration diagram showing a printer according to a third conventional example.

[Explanation of symbols]

1 Paper Feed Cassette 2 Paper Feed Roller 3 Conveying Roller Pair 4 Paper Conveying Unit 5 Fixing Unit 6 Intermediate Recording Unit 6a Intermediate Recording Belt (Counter Member) 7 Transfer Roller (Transfer Bias Member) 100 Image Recording Units 100Y, M, C, Bk Recording units 101Y, M, C, Bk Toner storage portions 102Y, M, C, Bk Toner carrying rollers (toner carrying bodies) 103Y, M, C, Bk Flying control plates (plate members) 104Y, M, C, Bk Facing Roller (counter electrode) 105Y, Bk hole (through opening) 106Y, Bk Flight control electrode 107Y Leads 200Y, M, C, Bk Photoreceptor drum (latent image carrier) 201Y, M, C, Bk Charging roller 202Y, M, C, Bk Developing device P Recording paper (image forming body) Bp PET bottle (image forming body)

Continued front page    (72) Inventor Kazuo Sakai             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F-term (reference) 2C062 RA01                 2C162 AE01 AE12 AE25 AE31 AE47                       AE52 AE69 AE74 AE84 AF07                       AH03 AH13 AJ16 AJ24 CA02                       CA12 CA24                 2H005 AA06 CA30                 2H029 DB13

Claims (24)

[Claims] 1. A toner carrier for carrying charged toner, a plurality of flight control electrodes for controlling the flight of the toner from the toner carrier, and a plurality of through openings facing the toner carrier. Prepare a plate-shaped member to have,
A step of applying a flight voltage to the flight control electrode, a step of passing the toner flying from the toner carrier by the application of the flight voltage through the through opening, and attaching the passed toner to an image forming body The image forming method for forming an image by carrying out the steps of (1) and (2) is characterized in that the surface of the image forming body before the toner is attached is charged to a polarity opposite to the charging polarity of the toner. 2. The image forming method according to claim 1, wherein the liquid having the opposite polarity charge is attached to the surface of the image forming body before the toner is attached, and the surface is charged. Image forming method. 3. The image forming method according to claim 1, wherein the solid fine particles having the opposite polarity charge are attached to the surface of the image forming body before the toner is attached, and the surface is electrically charged. Image forming method. 4. The image forming method according to claim 1, wherein the surface of the image forming body before the toner is attached is charged by electric discharge. 5. The image forming method according to claim 2, wherein the liquid is a soluble resin dissolved in a solvent. 6. The image forming method according to claim 2, wherein a liquid which becomes a solid at room temperature is liquefied and used as the liquid. 7. The image forming method according to claim 2, 3 or 6, wherein a curable resin or a plastic resin is used as the solid fine particles, or a liquid containing a curable resin or a plastic resin is used as the liquid. A characteristic image forming method. 8. The image forming method according to claim 7, wherein a toner containing a curing agent for the curable resin or a plasticizer for the plastic resin is used as the toner. 9. The image forming method according to claim 7,
An image forming method, wherein the curable resin or the plastic resin is made of the same material as the image forming body. 10. The image forming method according to claim 2, 3, 5, 6, 7, 8 or 9, wherein the charges of the opposite polarity are applied to the solid fine particles or liquid by corona discharge. Image forming method. 11. The image forming method according to claim 2, 3, 5, 6, 7, 8 or 9, wherein the charge of the opposite polarity is applied to the solid fine particles or liquid by charge injection. Image forming method. 12. The image forming method according to claim 2, 3, 5, 6, 7, 8 or 9, wherein the solid fine particles or the liquid is charged to the opposite polarity by friction. 13. The image forming method according to claim 2, 3, 5, 6, 7, 8 or 9, wherein the solid fine particles or liquid is charged to the opposite polarity by electrostatic induction. . 14. Claims 2, 3, 5, 6, 7, 8, 9, 1
In the image forming method of 0, 11, 12 or 13, an opaque and colored one is used as the solid fine particles or liquid. 15. The image forming method according to claim 2, 5 or 6, wherein the liquid is 1 [μm] to the image forming body.
An image forming method, characterized in that the image is attached with the above thickness. 16. Claims 2, 3, 4, 5, 6, 7, 8,
In the image forming method of 9, 10, 11, 12, 13, 14 or 15, 2 is provided between the flight control electrode to which the flight voltage is applied and the surface of the image forming body charged to the opposite polarity. An image forming method characterized by forming an electric field having an intensity of ⁶ [V / m] or more. 17. A method according to claim 2, 3, 5, 6, 7, 8, 9, 1.
In the image forming method of 0, 11, 12, 13, 14, 15 or 16, the solid fine particles or the liquid is attached only to a predetermined area capable of containing an image to be formed among all areas on the surface of the image forming body. An image forming method comprising: 18. The image forming method according to claim 7, 8 or 9, wherein a thermoplastic resin is used as the plastic resin, and toner is attached onto the solid fine particles or liquid attached to the image forming body. An image forming method, characterized in that the image forming body is heated. 19. Claims 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15, 16,
19. The image forming method according to 17 or 18, wherein the image forming object after image formation is destaticized. 20. A toner carrier for carrying charged toner, a plurality of flight control electrodes for controlling the flight of the toner from the toner carrier, and a plurality of through openings facing the toner carrier. Preparing a plate-shaped member having and a facing member facing the toner carrier via the plate-shaped member, and applying a flight voltage to the flight control electrode;
The step of passing the toner, which has flown from the toner carrier by the flight voltage, through the through opening, the step of attaching the passed toner to the facing member, and the formation of the toner on the facing member by the attachment In the image forming method of forming an image by performing a step of transferring a toner image to an image forming body, the surface of the image forming body before transferring the toner image is charged to a polarity opposite to the charging polarity of the toner. An image forming method comprising: 21. A step of forming a latent image on a latent image carrier, a step of adhering charged toner to the latent image on the latent image carrier to obtain a toner image, and the toner image being an image forming body. In the image forming method for forming an image on the image forming body by performing the transfer to the surface of the image forming body before the transfer of the toner image. An image forming method characterized in that the solid fine particles or liquid having the same are attached to charge the surface to the opposite polarity. 22. A toner image carrier for carrying a toner image,
While facing the image forming body, a transfer electric field is applied to the toner image on the toner image carrying body to apply an electrostatic force from the toner image carrying body toward the image forming body to form the toner image. In the transfer method for transferring to the image forming body,
Transfer characterized in that solid fine particles or liquid having a charge opposite in polarity to the toner is attached to the surface of the image forming body before the toner image is transferred, and the surface is charged to the opposite polarity. Method. 23. A toner carrier for carrying charged toner, a plurality of flight control electrodes for controlling the flight of the toner from the toner carrier, and a plurality of through openings facing the toner carrier. And a plate-shaped member having a sheet-like member having the flying control electrode, and the toner flying from the toner carrier is caused to pass through the through-opening by applying a flying voltage to the flying control electrode, and the toner after passing is adhered to an image forming body to form an image. In the image forming apparatus for forming the image forming apparatus, there is provided a charging unit for charging the surface of the image forming body before the toner is attached to a polarity opposite to the charging polarity of the toner. 24. A toner carrier for carrying charged toner, a plurality of flight control electrodes for controlling the flight of the toner from the toner carrier, and a plurality of through openings facing the toner carrier. The flying member is provided with: a plate-shaped member having; a facing member that faces the toner carrier via the plate-shaped member; and a transfer unit that transfers a toner image formed on the facing member to an image forming body. In an image forming apparatus for forming a toner image by causing the toner flying from the toner carrier to pass through the through-opening by applying a flying voltage to the control electrode and depositing the toner after passing on the facing member. An image forming apparatus comprising a charging means for charging the surface of the image forming body before transferring the toner image to a polarity opposite to the charging polarity of the toner.