JPH10798A - Image forming device - Google Patents

Abstract

(57) [Problem] To provide an image recording apparatus which does not require a charging step without using a photoreceptor, has a simple configuration, does not cause a problem of ozone, and has excellent image stability. SOLUTION: An image carrier 1 is formed in a belt shape, is held under tension between a driving roller (not shown) and a holding roller 4, and is moved in the direction of an arrow at the time of image formation. The image carrier 1 includes a tackiness generating layer 1a and its base 1b. During recording, the thermal head 2 is heated to generate tackiness in the layer 1a. The pressure plate 3 is for improving the contact state between the thermal head 2 and the image carrier 1, and the pressure plate 3 is in contact with the image carrier 1 during heating. With the movement of the image carrier 1, adhesion on the image carrier 1,
The non-adhesive pattern moves and is visualized by the colored powder in the coloring device 7. Further, the colored powder image is transferred by the transfer roller 5 with the movement of the image carrier 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly, to a copying machine and a printer for obtaining an image using colored powder.

[0002]

2. Description of the Related Art In electrophotographic image formation, generally,
Using a photoreceptor, the photoreceptor is charged, exposed, light-written, and developed, and the developed image is transferred and fixed on recording paper to obtain an image. Although this method is widely used, ・ The number of processes is large and the recording device is complicated. ・ Especially, when a corona charger widely used in the charging / transfer process is used, a large amount of ozone is generated by corona discharge. Had to be equipped with a filter for removing ozone. ・ Moreover, using a photoreceptor to form an electrostatic latent image to obtain an image, the image was highly environmentally dependent, And so on.

[0003] In order to solve such a problem, the inventions described in Japanese Patent Application Laid-Open Nos. Hei 2-167761 and Hei 5-16519 have been proposed. These inventions use a liquid material without using an electrostatic latent image, the former on an intermediate recording medium,
The latter is to directly adhere to the transfer material. The above-mentioned problems have been solved because a photoconductor is not used and an electrostatic latent image is not interposed. However, when a liquid material is directly attached to form a pattern, it is necessary to form fine droplets. However, there is a problem that it is difficult to secure clogging, stable position accuracy, and easy handling.

[0004]

As described above, the image forming apparatus of the electrophotographic type has the following disadvantages. The number of steps is large and the recording apparatus is complicated. In particular, the corona charging widely used in the charging / transferring step. When using a container, a large amount of ozone was generated due to corona discharge, and a filter for removing ozone had to be provided. ・ Also, using a photoreceptor to form an electrostatic latent image However, there is a problem that the image is greatly dependent on the environment in order to obtain the image. Also, in a recording apparatus in which a liquid material is directly adhered to an intermediate recording body or a transfer machine without using an electrostatic latent image, and a photoconductor or an electrostatic latent image is not interposed, the liquid material is directly adhered. Go to form a pattern,
It is necessary to form fine droplets, and there is a problem that it is difficult to secure clogging, stable position accuracy, and easy handling.

[0005]

According to the first aspect of the present invention, there is provided an image carrier having on its surface a material which generates tackiness by heating, heating means for selectively heating the image carrier,
It is characterized by having a coloring means for adhering a colored powder to the adhesive portion, so that a charging step is not required without using a photoreceptor, the configuration is simple and no ozone problem occurs, To provide an image recording apparatus which is also excellent in the stability of the image recording apparatus.

According to a second aspect of the present invention, in the first aspect of the present invention, the material generating tackiness by heating is a polymer in which a unit constituting the polymer has a long-chain alkyl group having 12 to 22 carbon atoms. Shows crystallinity when heated,
It is characterized by having a temperature region in which the elastic modulus sharply decreases, thereby obtaining a good image by having a temperature region in which the elastic modulus sharply decreases.

According to a third aspect of the present invention, in the first aspect of the present invention, the heating means is a thermal head, and the heating means contacts and heats the adhesive generating material on the surface of the image carrier. Thus, the amount of heat required for the generation of tackiness is reduced by directly heating the portion to be changed in state.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the image bearing member is formed in a belt shape, and a portion of the image bearing member that contacts the thermal head that narrows the image bearing member contacts the substrate of the image bearing member. And a pressure member for improving the contact state between the thermal head and the adhesive generating material during thermal writing, thereby increasing the heating efficiency.

According to a fifth aspect of the present invention, in the first aspect, the image carrier is formed in a belt shape, the heating means is a thermal head, and the thermal head contacts and heats the image carrier on the substrate side. In this case, the image pattern is written without contacting the adhesive surface on which the image is to be formed, whereby deterioration such as abrasion due to rubbing is prevented.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, a pressure member is provided at a portion facing the thermal head for narrowing the image carrier, the pressure member being in contact with the adhesive generating material. By writing an image pattern without touching the surface of the sticky material on which the image is to be formed, it is possible to prevent deterioration such as abrasion due to rubbing and to improve the contact state between the thermal head and the sticky material, It is designed to improve efficiency.

The invention according to claim 7 is characterized in that, in the invention according to claim 6, the pressure member is a coloring means.
By applying colored powder from a coloring means, the tackiness generated by heating reduces the possibility of the material generating the tackiness being cooled and being lost, so that a clear image can be obtained. It is.

According to an eighth aspect of the present invention, in the first aspect of the present invention, selective heating is performed by irradiating light, and thus, the presence or absence of adhesion to the image carrier in a non-contact state. Thus, it is possible to form an image pattern according to the above-mentioned method, and to reduce the abrasion due to rubbing and the application of mechanical pressure.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, a substance having an absorption at a wavelength of light used for heating is contained in the tackiness generating layer of the image bearing member. In the tackiness-generating layer that generates the property, the irradiated light is absorbed to generate heat, so that blurring of the image due to diffusion is reduced.

According to a tenth aspect of the present invention, in the eighth aspect of the present invention, the base of the image carrier contains a substance having an absorption at a wavelength of light used for heating, thereby simplifying the structure of the adhesive substance. This facilitates the production of a sticky substance.

According to an eleventh aspect of the present invention, in the invention of the eighth aspect, the adhesive generating material is selectively heated at a contact portion with the coloring means. At the same time, the coloring powder adheres from the coloring means, thereby reducing the possibility that the adhesive generated by heating reduces the possibility of the material being cooled and lost. This makes it possible to form an image pattern depending on the presence or absence, and to reduce wear and mechanical additional pressure due to rubbing.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In electrophotographic image formation, an electrostatic charge pattern is formed on a photoreceptor by using an image carrier called a photoreceptor whose conductivity changes by light irradiation. In order to form this electrostatic charge pattern, a corona charger for initial charging is usually used. As described above, there are many problems caused by the use of electrostatic charges for image formation.

According to the present invention, instead of forming an electrostatic charge pattern, an adhesive or non-adhesive pattern is formed on an image carrier. The image carrier is composed of a substance that generates tackiness and a substrate that holds the substance. The sticking substance is
It is a polymer gel formed by bridging an acrylic acid polymer having long-chain ester groups on the side chains.The transition between crystalline and amorphous states occurs at the long-chain ester groups due to temperature history. As a result, the entire gel hardens and softens.

FIG. 7 is a graph showing a typical temperature dependency of the elastic modulus. In FIG. 7, the elastic modulus rapidly changes in a region indicated by a. Explaining the structure, by adding acrylic and divinyl monomers having a long-chain alkyl group to the polymer, a sufficient cross-linking structure and crystallinity were obtained, and the phenomenon that the elastic modulus suddenly decreased at a certain temperature was observed. . The cause of this crystallinity is that by including a long-chain alkyl group in the polymer at a certain value or more, the long-chain alkyl group expresses hydrophobic interaction with each other, which makes it possible to have apparent crystallinity. I think it has become.

The monomers used in the polymer of the present invention include lauryl acrylate, stearyl acrylate, behenyl acrylate, lauryl methacrylate,
Examples of stearyl methacrylate and behenyl methacrylate include, but are not limited to, those having a long chain. As the divinyl monomer, one monomer unit may contain two vinyl groups,
Divinylstyrene, propylene glycol dimethacrylate, ethylene glycol dimethacrylate, 5-ethyl-2-hydroxy-1,1-dimethylethyl-5-hydroxymethyl-1,3-dioxane acrylate, N, N'-methylenebisacrylamide Etc. are raised.

The monomers forming the binder resin used in the present invention include styrene, o-methylstyrene,
m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, pn-
Styrenes such as nonylsterene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene; ethylene, propylene, butylene, Ethylenically unsaturated monoolefins such as isobutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl acetate; methyl acrylate; Ethyl acrylate, acrylic acid-n-
Butyl, methyl methacrylate, ethyl methacrylate, trifluoroethane acrylate, hexafluoroisopropyl acrylate, tetrafluoropropyl acrylate,
Α-methylene aliphatic monocarboxylic acid esters such as octafluoropentyl acrylate and heptadecafluorodecyl acrylate; vinyl ethers such as vinyl methyl ether; vinyl ketones such as vinyl methyl ketone;
And N-vinyl compounds such as -vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone and the like. These monomers are
They can be used alone or in combination of two or more.

The monomers for forming the polycondensation type resin include ethylene glycol, triethylene glycol, 1,2-propylene glycol, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxyethylenated bisphenol A. Polyhydric alcohols such as oxypropylene-modified bisphenol A, polyhydric amines such as etalenediamine, tetramethylenediamonpiperazine, and maleic acid, fumaric acid, mesaconic acid, citraconic acid, adipic acid, malonic acid, or these Examples thereof include acid anhydrides and esters with lower alcohols. Further, the present invention is not limited to the resin monomers shown here.

In using this tackiness generating substance for image formation, a temperature portion above the region a and a temperature portion below the region a are formed by selective heating to form a pattern. The temperature is equal to or higher than the region a, and the powder adheres to the softened portion by pressing the colored powder. This is considered to indicate the adhesiveness with the powder due to the increase in the surface area due to the softening of the gel.

A material containing a fluorine-based monomer as a material for the stickiness-generating substance is a colored powder, exhibits good releasability, and is effective for image formation. As the selective heating means,
There are a laser, use of an LED in a heat mode, and a thermal head. When a thermal head is used, there is an advantage that the structure is the simplest and inexpensive, and in the case of light heating, there is an advantage that an image can be formed on the image carrier without contact. Furthermore, LEDs are advantageous in terms of system miniaturization and configuration flexibility.

By selectively heating the material, a pattern of tackiness is formed. In the next step, the colored powder is adhered to the tackiness generating portion to form a visible image, so that the tackiness must be generated at least on the surface of the image carrier. When writing is performed in a heat mode of light such as a laser or an LED, it is important that light is efficiently absorbed and energy is converted to heat. Generally, the adhesive material is colorless and transparent, and has poor light absorption.Therefore, the image carrier has a layer of a substance that absorbs light, or a substance that absorbs the wavelength of light mixed in the adhesive material. Form the adhesive material above.

As the light-absorbing substance, various pigments can be used according to the wavelength of light, such as metal chelate dyes such as carbon black, oil black, nigrosine dye, metal-containing dye, aniline dye, and calco oil blue. , Chrome yellow, ultramarine blue, methylene blue chloride, phthalocyanine blue, rose bengal, and other dyes or pigments. Since the coloring with the powder must be performed while the image portion of the image carrier has tackiness, the temperature of the surface of the image carrier at the colored portion becomes important. Before the temperature of the image portion becomes lower than the transition temperature, the image portion is colored. Therefore, it is necessary that the distance between the image writing portion and the coloring portion is sufficiently short by heating. A system in which writing and coloring are performed simultaneously is also preferable.

The coloring means is, for example, a rubber roller carrying powder on the surface. Since the image carrier and the powder carrier of the coloring means come into contact with each other and transfer the powder, it is desirable that the image carrier and the powder carrier be in contact with each other with a certain nip portion from the viewpoint of system stability. Specifically, it is preferable that the image carrier has elasticity or the powder carrier has elasticity. When the image carrier is made of a rigid body such as aluminum and an adhesive generating material, the coloring means uses an elastic body such as a rubber roller or a sponge, and the image carrier is in a belt shape. The coloring means may be made of an elastic material, but may be made of a rigid material. As an example of the coloring means, sandblasting or knurling the surface is also effective for the purpose of assisting the transfer of the powder with a SUS aluminum roller.

The colored powder may be any colored powder. However, since the resolution of an image depends on the particle diameter of the powder in principle, a finer powder is desirable. The toner in electrophotography is required to be charged to a predetermined amount of charge because the electrophotography forms an image by electrostatic force, but in this method, electric power is not directly used for image formation. There is no need for charging. However, when it is preferable to be charged in terms of transporting the powder and other handling, it may be charged. The colored powder on the image carrier is transferred to a transfer material by a transfer unit and fixed to form an image.

Embodiment 1 FIG. 1 is a structural view of a main part for explaining an embodiment of the present invention. In FIG. 1, 1 is an image carrier, 2 is a thermal head, 3 is a thermal head 2 and an image carrier. 1, a pressing member for holding the image carrier; 5, a transfer roller for transferring a colored powder image formed on the image carrier; 6, a transfer material; Is a coloring device for coloring and visualizing the adhesive image. In this configuration example, the image carrier 1 is formed in a belt shape, is held in a state where tension is applied between a driving roller (not shown) and the holding roller 4, and is moved in the direction of an arrow at the time of image formation. The image carrier 1 has an adhesive generating layer 1a.
And the substrate 1b. The substrate 1b is a 75 μm polyimide film, and the adhesion generating layer 1a is a styrene acrylic gel. This styrene acrylic gel is
It is synthesized so that the temperature at which the adhesiveness changes is about 60 ° C. The thermal head 2 is 300 dpi. The temperature of the thermal head during recording depends on the recording speed, but may be around 150 ° C. at a speed of about 30 mm / s. The pressing plate 3 is for improving the contact state between the thermal head 2 and the image carrier 1. Since the pressing plate 3 is in contact with the image carrier 1 during heating, it has poor heat conductivity. Is desired, and is made of Teflon resin having heat resistance. Writing is possible even without the pressure plate 3. With the movement of the image carrier 1, the adhesive or non-adhesive pattern on the image carrier 1 moves and is visualized by the coloring device 7 with colored powder. Further, the colored powder image is transferred by the transfer roller 5 with the movement of the image carrier 1.

Embodiment 2 FIG. 2 is a structural view of a main portion for explaining another embodiment of the present invention. In this embodiment, a thermal head 2 is brought into contact with an image carrier 1 from the side of a substrate 1b. This is an example of performing image writing by selective heating. The thickness of the tackiness generating material 1a is about 50 microns, and the substrate 1b is polyimide and has a thickness of about 50 microns. Since the thermal head 2 indirectly applies heat to the adhesive generating material 1a, it is necessary to heat the thermal head 2 at a higher temperature than in the case of direct heating as in the first embodiment. Heat to about. In addition, the thickness of the substrate 1b greatly affects the resolution of an image because of indirect heating. Therefore, it is preferable to be as thin as possible. The roller 7a of the coloring device 7 is a silicone roller that is in contact with the tackiness generating material, and holds the colored powder on the surface of the roller 7a by adhesion. The colored powder is not charged. At the same time as the heating generates tackiness, the colored powder adheres to the portion and is visualized. The adhesive force between the silicone roller 7a and the colored powder is extremely weak and easily adheres to the adhesive portion generated by heating.

FIG. 3 shows an example in which heating is performed from the side of the base 1b, similarly to the embodiment shown in FIG. 2, but this embodiment shows an example in which coloring is not performed simultaneously with heating. roller 8 is roller structure covering the surface of the urethane roller ₈₁ Teflon tube ₈₂ has a good releasing property with the portion having the adhesive. In addition, since the image carrier 1 rotates with the movement of the image carrier 1 and has a small outer diameter of 10 mm, the mold release is facilitated.

Example 3 FIG. 4 is a view showing an example of optical writing. Reference numeral 11 denotes a light source such as an LED array, 12 denotes an image carrier, 12a denotes an adhesive generating material, 12b denotes a base, and a light source such as an LED array. Reference numeral 11 is assembled so as to form an image on the image carrier 12. At the same time as the LED exposure, the coloring device 7 causes the coloring powder to adhere.

FIG. 5 is a view for explaining the structure of the image carrier 12, and the structure shown in FIG. 5A absorbs the LED in the adhesive generating material 12a used in this embodiment. in which it is dispersed the material 12a _1. In this embodiment, Rose Bengal is used. The configuration shown in FIG.
As a substrate 12b of the tackiness generating material 12a, a layer (for example, carbon black) 1 of a substance that absorbs the wavelength of the LED
2b ₁ in which a resin 12b ₂ attached to. Of course, the resin itself may absorb light or a substance dispersed in the resin may absorb light in the sense that the base 12b has a light absorbing function. Although an example in which an LED is used as a light source has been described, this applies to all cases in which heating and writing is performed using light, and the same applies to laser light.

Embodiment 4 FIG. 6 is a diagram showing the main parts of another embodiment of the present invention. In this embodiment, optical writing is performed, and coloring is performed by a coloring device 7 after writing. In order to increase the contact width at the time of coloring, the roller 7a of the coloring device 7 is set so as to bite into the image carrier belt 12. Thereby, more stable coloring can be performed.

[0034]

According to the first aspect of the present invention, an image carrier having on its surface a material which generates tackiness by heating, heating means for selectively heating the image carrier, and Since it has coloring means for adhering colored powder, it does not use a photoreceptor and does not require a charging step. Therefore, an image recording apparatus which has a simple configuration, does not cause ozone problems, and has excellent image stability. Can be provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the material generating tackiness by heating is a polymer in which a unit constituting the polymer has a long-chain alkyl group having 12 to 22 carbon atoms, Since it has crystallinity when not heated and has a temperature region where its elastic modulus sharply decreases, a good image can be obtained by having a temperature region where its elastic modulus sharply decreases.

According to a third aspect of the present invention, in the first aspect of the present invention, the heating means is a thermal head, and the thermal head contacts and heats the sticky material on the surface of the image carrier, so that the state is changed by heat. By directly heating the portion to be made, the amount of heat required for the generation of tackiness can be reduced.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the image bearing member is formed in a belt shape, and the pressing member in contact with the base is provided at a portion opposed to the thermal head that narrows the image bearing member. With this arrangement, the contact state between the thermal head and the adhesive generating material can be improved at the time of thermal writing, and the heating efficiency can be increased.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the image carrier is formed in a belt shape.
The heating means is a thermal head, and the thermal head contacts and heats the substrate side of the image carrier, so that the image pattern is written without contacting the tackiness generating surface on which the image is formed, so that the rubbing is performed. Degradation due to wear and the like can be prevented.

According to the sixth aspect of the present invention, in the fifth aspect of the present invention, since a pressure member for contacting the adhesive material is provided at a portion facing the thermal head, which narrows the image carrier, so that image formation is performed. By writing an image pattern without touching the sticky surface, it is possible to prevent deterioration such as abrasion due to rubbing, improve the contact state between the thermal head and the sticky material, and improve heating efficiency. I can give it.

According to the seventh aspect of the present invention, in the sixth aspect of the present invention, since the pressing member is a coloring means, the tackiness is generated by heating and writing, and the coloring powder adheres from the coloring means. The adhesive generated by heating is less likely to lose the material due to cooling, and a clear image can be obtained.

According to the eighth aspect of the present invention, in the first aspect of the present invention, since the selective heating is performed by irradiating light, an image pattern is formed on the image carrier in a non-contact state by the presence or absence of adhesiveness. It is possible to reduce wear and mechanical additional pressure due to rubbing.

According to the ninth aspect of the present invention, in the invention of the eighth aspect, since the substance having absorption at the wavelength of light used for heating is contained in the tackiness generating layer of the image carrier, the tackiness is reduced by heating. By absorbing the irradiated light and generating heat in the generated tackiness generating layer, blurring of the image due to diffusion can be reduced.

According to a tenth aspect of the present invention, in the invention of the eighth aspect, since the substrate of the image bearing member contains a substance having an absorption at a wavelength of light used for heating, the substrate holding the sticky generating substance is provided. By having a substance that absorbs light for heating, the configuration of the sticky substance can be simplified and the preparation can be facilitated.

According to the eleventh aspect of the present invention, in the invention of the eighth aspect, the adhesive generating material is selectively heated at a contact portion with the coloring means, so that the adhesive is generated by heating and writing, and When the colored powder adheres, the adhesiveness generated by heating is less likely to be lost due to the cooling of the material, and an image pattern is formed on the image carrier depending on the presence or absence of the adhesiveness in a non-contact state. Therefore, wear and mechanical addition due to rubbing can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a main part for describing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a main part for describing another embodiment of the present invention.

FIG. 3 is a diagram illustrating an example in which coloring is not performed simultaneously with heating.

FIG. 4 is a main part configuration diagram for explaining an embodiment of optical writing.

FIG. 5 is a diagram for describing a configuration example of an image carrier.

FIG. 6 is a diagram showing a configuration example of a main part for describing another embodiment of the present invention.

FIG. 7 is a graph showing the temperature dependence of the elastic modulus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image carrier, 1a ... Tackiness generating material, 1b ... Substrate, 2
... thermal head, 3 ... pressing member, 4 ... roller, 5 ... transfer roller, 6 ... transfer material, 7 ... coloring device, 8 ... roller, 1
DESCRIPTION OF SYMBOLS 1 ... Light source, 12 ... Image carrier, 12a ... Tackiness generating material,
12b: substrate, 12a ₁ : light-absorbing substance, 12b ₂ ...
A layer of material that absorbs at the wavelength of the LED.

Claims (11)

[Claims] 1. An image bearing member having on its surface a material that generates tackiness by heating, heating means for selectively heating the image bearing member, and coloring means for attaching colored powder to the sticky portion. An image forming apparatus comprising: 2. The material which generates tackiness by heating is a polymer in which a unit constituting the polymer has a long-chain alkyl group having 12 to 22 carbon atoms, exhibits crystallinity when not heated, and has an elastic modulus. The image forming apparatus according to claim 1, wherein the image forming apparatus has a temperature region that rapidly decreases. 3. The heating means is a thermal head,
2. The image forming apparatus according to claim 1, wherein the surface of the image carrier is heated in contact with the tackiness generating material. 4. The image carrier is formed in a belt shape, and a pressure member is provided at a portion where the image carrier is narrowed and opposed to the thermal head, in contact with a base of the image carrier. The image forming apparatus according to claim 3. 5. The image carrier according to claim 1, wherein the image carrier is formed in a belt shape, and the heating means is a thermal head, and the thermal head contacts and heats the image carrier on a substrate side. The image forming apparatus as described in the above. 6. The image forming apparatus according to claim 5, wherein a pressure member is provided at a portion facing the thermal head by narrowing the image carrier, in contact with the adhesive material. 7. The image forming apparatus according to claim 6, wherein the pressing member is a coloring unit. 8. The image forming apparatus according to claim 1, wherein the heating means for selectively heating is a heating means for heating by applying light. 9. The image forming apparatus according to claim 8, wherein a substance having absorption at a wavelength of light used for heating is contained in the tackiness generating layer of the image carrier. 10. The image forming apparatus according to claim 8, wherein the base of the image carrier contains a substance having absorption at a wavelength of light used for heating. 11. The image forming apparatus according to claim 8, wherein the adhesive generating material is selectively heated at a contact portion with the coloring unit.