JP2002207334A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of forming an image by setting a semi-gloss surface as the character area of the image and optionally selecting a glossy, semi-gloss or gloss surface as a photographic area. SOLUTION: A processing unit 100T equipped with a developing device 13A having semi-gloss transparent toner and a developing device 13B having glossy transparent toner is disposed at the most upstream position in the carrying of a transfer belt 14a, a glossy transparent toner layer corresponding to the photographic area and a semi-gloss transparent toner layer all over the image area are superposed and formed on a photoreceptor drum 10, and respective color toner images are superposed on a transparent toner layer on the belt 14a so as to form a color toner image, and then the transparent toner layer and a color toner layer are collectively transferred to recording paper P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine, and more particularly to an image forming apparatus in which a color image portion or a designated area is covered with a transparent toner.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, it is generally required that a document image be faithfully reproduced. For example, since a photo document has a gloss, a copy image is also a gloss image. It is required that there be. Japanese Patent No. 3030576 proposes to use a transparent toner for a range where gloss is required and to make the range glossy. The transparent toner used here is a toner in which a colorant is removed from the toner for developing a color image, and the fixing temperature of the fixing unit is set high, the pressure during fixing is increased, and the fixing time is increased. There is disclosed means for obtaining a glossy image in a range where the transparent toner adheres.

In general, a glossy or non-glossy image is obtained from a toner image depending on the relationship between characteristics such as the glass transition temperature of the toner and fixing conditions.

[0004]

Generally, a photographic image is required to be a glossy image, but a character image is required to be a non-glossy image because characters are easy to read. .

A first object of the present invention is to provide an image forming apparatus capable of forming a character region of an image as a semi-glossy surface and arbitrarily selecting and forming a photographic region on a glossy, semi-glossy or glossy surface. .

A second object is to form a clear color image with good coloring by forming a transparent toner layer between a white toner layer and a color toner image on a transfer material. A third object is to provide a color image with higher sharpness by reducing the amount of charge for forming the white and transparent toner layers to increase the adhesion of the color toner image.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which a color toner image transferred onto a transfer material is fixed to a transparent toner layer, wherein the transparent toner forming the transparent toner layer is different. 2. An image forming apparatus comprising two kinds of transparent toners having glossiness.
And an image forming apparatus that forms a white toner layer and a color toner image on a transfer material, wherein a transparent toner layer is provided between the white toner and the color toner. 5 according the invention), and the white toner layer on a transfer material, the transparent toner layer in an image forming apparatus for forming a color toner image, white toners and the transparent toner charge layer Q _1, the color toner and the charge amount Q ₂ The image forming apparatus has a relationship of Q ₁ <Q _2.
Invention according to the present invention).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and function of an image forming apparatus according to the present invention will be described with reference to FIGS.

The image forming apparatus shown in FIGS. 1 and 3 forms a color toner image by superimposing color toner images on an intermediate transfer member, and retransfers the color toner image onto a transfer material. On the other hand, the image forming apparatus shown in FIGS. 2 and 4 is an image forming apparatus of a type in which color toner images are formed by superimposing color toner images directly on a transfer material.

Each of the above image forming apparatuses comprises an image reading section A, an image processing section, an image forming section E and the like.

At the top of the image forming apparatus, a document table made of a transparent glass plate or the like, and a document D further placed on the document table
There is a document placing portion 111 composed of a document cover or the like that covers
The first mirror unit 112, the second mirror unit 113, the main lens 12
0, an image reading unit A including a color CCD 123 and the like is provided. The first mirror unit 112 includes an exposure lamp 114 and a first mirror 115. The first mirror unit 112 is mounted in parallel with the document table and linearly movable in the horizontal direction of the drawing, and optically scans the entire surface of the document D. The second mirror unit 113 integrally includes a second mirror 116 and a third mirror 117, and linearly moves in the same direction on the left and right at half the speed of the first mirror unit 112 so as to always maintain a predetermined optical path length. Of course, the movement of the second mirror unit 113 is parallel to the platen similarly to the first mirror unit 112. The image of the document D on the document table illuminated by the exposure lamp 114 is formed on the color CCD 123 by the main lens 120 via the first mirror 115, the second mirror 116, and the third mirror 117. I have.
When the scanning is completed, the first mirror unit 112 and the second mirror unit 113 return to their original positions, and wait for the next copy.

Image data of each color obtained by the color CCD 123 is subjected to image processing in an image processing section.
Laser writing is performed on an image forming unit E described below as an image signal.

The image forming apparatus (I) shown in FIGS.
A) and (IB) show a tandem-type color image forming apparatus using an intermediate transfer member as an image forming portion E. The transfer belt 14a, which is an intermediate transfer member, has a yellow (Y), magenta (M) ), Cyan (C), black (K), and transparent (T) are provided, and each process unit 100 includes Y, M,
C, K, and T toner images are formed, the toner images are transferred in a superimposed manner on the transfer belt 14a, and the transferred color toner images are collectively transferred onto recording paper as a transfer material.
The toner is fixed and discharged outside the machine. The image forming apparatuses (IA) and (IB) have five process units 1
Since only the arrangement order of 00 (therefore, the image formation order) is different, the image forming apparatus (IA) shown in FIG. 1 will be described.

Of the five process units 100, each of the four process units 100 except for the transparent (T) has a common structure, and only one of them will be described. The photoconductor drum 10, which is an image forming body, has a photoconductor layer of a conductive layer and an organic photoconductor layer (OPC) formed on the outer periphery of a cylindrical substrate.

The photosensitive drum 10 is rotated in a counterclockwise direction indicated by an arrow with the conductive layer grounded by power from a driving source (not shown) or by the transfer belt 14a.

Reference numeral 11 denotes a scorotron charger as charging means, which is attached to the photosensitive drum 10 in a direction orthogonal to the moving direction of the photosensitive drum 10 so as to face and be close to the photosensitive drum 10;
The photosensitive drum 1 is driven by corona discharge having the same polarity as the toner.
A uniform potential is given to 0.

Reference numeral 12 denotes Y, M, C,
An exposure optical system that performs image exposure of K and T in accordance with an instruction from the control unit, and is a scanning optical system that performs scanning in parallel with the rotation axis of the photosensitive drum 10 using, for example, a polygon mirror. Exposure optical system 1 on photoreceptor drum 10 uniformly charged
The latent image is formed by performing the image exposure by the method 2.

A developing unit 13 containing a two-component developer composed of a negatively charged conductive toner and a magnetic carrier is provided at the periphery of the photosensitive drum 10, and a magnet is built in to hold the developer. The reversal development is performed by the rotating developing sleeve 13a.

The developer is a carrier having a ferrite core as a core and an insulating resin coated around the core, and a colorant having a weight average particle diameter of 3 to 10 μm to which a colorant such as a pigment or carbon black is added or which does not contain a colorant. A charge control agent, silica, titanium oxide, or the like is added to the toner and mixed so that the toner concentration becomes 5 to 10% by mass. The toner is regulated on the developing sleeve 13a to a layer thickness of 0.1 to 0.6 mm and developed. Transported to the area.

The gap between the developing sleeve 13a and the photosensitive drum 10 in the developing zone is larger than the layer thickness of the developer.
As 2～1.0Mm, applies an AC bias voltage obtained by superposing an AC voltage V _AC to a DC voltage V _DC between the developing sleeve 13a and the photosensitive drum 10. Since charging of the toner is a DC voltage V _DC of the same polarity (negative), the toner given the opportunity to leave from the carrier by the AC voltage V _AC, the part of the high V _H absolute value of the potential from the DC voltage V _DC And the toner amount corresponding to the potential difference adheres to the portion of _VL where the absolute value of the potential is low, and the image is visualized (reversal development).
Further, only the DC voltage _VDC may be applied between the developing sleeve 13a and the photosensitive drum 10. The development may be contact development. This toner image is transferred onto a transfer belt 14a described later at a transfer position. The transfer residual toner remaining on the drum after the transfer is cleaned by a cleaning device 19 that electrostatically collects the toner.

A transfer belt 14 in which four, Y, M, C, and K color and transparent (T) process units 100 face in parallel.
a is a volume resistivity of 10 ¹⁰ to 10 ¹⁵ Ω · cm, and a surface resistivity of 1
It is an endless belt having a thickness of 0 ¹⁰ to 10 ¹⁵ Ω / □, which is obtained by dispersing a conductive material in an engineering plastic such as a modified polyimide, a thermosetting polyimide, an ethylene tetrafluoroethylene copolymer, a polyvinylidene fluoride, and a nylon alloy. A fluorine coating having a thickness of 5 to 50 μm was formed on the outside of a semiconductive film substrate having a thickness of 1 to 1.0 mm, preferably as a toner filming preventing layer.
It is a seamless belt having a layer configuration. In addition, as the base of the transfer belt 14a, a semiconductive rubber belt having a thickness of 0.5 to 2.0 mm in which a conductive material is dispersed in silicon rubber or urethane rubber can be used. The transfer belt 14a is stretched around a drive roller 14d, a driven roller 14e, a tension roller 14k, and a backup roller 14j. During image formation, the drive roller 14d is rotated by a drive motor (not shown). At the transfer position for each color, the transfer belt 14a is pressed against the photosensitive drum 10 by the primary transfer device 14c, and the transfer belt 14
a is rotated in the direction indicated by the arrow in the figure.

A primary transfer device 14c, which is a transfer roller as a transfer means for each color including transparent, is provided to face the photosensitive drum 10 for each color with the transfer belt 14a interposed therebetween.
A transfer area (no symbol) for each color is formed between the transfer belt 14a and the photosensitive drum 10 for each color. A DC voltage having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied to the primary transfer device 14c for each color, and a transfer electric field is formed in the transfer area. The toner image is transferred onto the transfer belt 14a.

Separation electrode 14n, which is a static eliminator for each color
Is preferably constituted by a corona discharger, and removes electricity from the transfer belt 14a charged by the primary transfer device 14c.

When the image recording starts, the photosensitive drum 10 of the transparent (T) process unit 100 is rotated in the direction shown by the arrow in FIG. The application of a potential to the T photoconductor drum 10 is started by the charging action.

After the potential is applied to the photosensitive drum 10 of T, image writing is started by an electrical signal output from a control unit described later by the exposure optical system 12 of T, and the surface of the photosensitive drum 10 of T is started. Then, an electrostatic latent image corresponding to the output image from the control unit is formed.

The latent image of T is described later in detail.
The reversal development is performed by the transparent toner developing device 13 in a non-contact state, and a toner image is formed by the T transparent toner according to the rotation of the T photoconductor drum 10.

The T toner image composed of the transparent toner formed on the T photosensitive drum 10 serving as an image forming body by the above-described image forming process is subjected to the primary transfer of T in the T transfer area (no sign). The transfer belt 14
a.

Slightly behind the operation of the transparent (T) process unit 100, the black (K) process unit 100
Is rotated in the direction indicated by the arrow in FIG.
At the same time, application of a potential to the K photoconductor drum 10 is started by the charging action of the K scorotron charger 11A.

After a potential is applied to the K photosensitive drum 10, the K exposure optical system 12 starts image writing with an electric signal corresponding to the K image data in synchronization with the T toner image. An electrostatic latent image corresponding to the K image of the original image is formed on the surface of the photosensitive drum 10.

The K latent image is subjected to reversal development by the K developing unit 13 in a non-contact state, and a toner image is formed by K toner in accordance with the rotation of the K photosensitive drum 10.

The K toner image formed on the K photoreceptor drum 10 as an image forming body by the above-described image forming process is transferred by the K primary transfer unit 14c in the K transfer area (no sign). The image is transferred onto the T toner image on the transfer belt 14a.

Next, the transfer belt 14a is synchronized with the toner image of C, and the process unit 10 of cyan (C) is
0, the C toner image corresponding to the C image data formed on the C photoreceptor drum 10 is transferred by the C primary transfer unit 14c in the C transfer area (no symbol) in the T primary transfer unit 14c. A toner image of C is superposed on the toner image of.

By the same process, the image is synchronized with the superposed toner image of T, K, and C, and is converted into the M image data formed on the M photoconductor drum 10 by the magenta (M) process unit 100. The corresponding M toner image is
In the M transfer area (unsigned), the M primary transfer device 14
c, the toner images of M are superimposed on the toner images of T, K, and C, and the toner images of T, K, C, and M are further formed.
Is synchronized with the superimposed toner image of yellow (Y)
Y photosensitive drum 10 by the process unit 100
The Y toner image corresponding to the Y image data formed above is transferred to the T, K, C, and M toner images by the Y primary transfer unit 14c in the Y transfer area (no sign). Are formed on top of each other, and a superposed color toner image of T, K, C, M and Y is formed on the transfer belt 14a.

The transfer residual toner remaining on the peripheral surface of the photosensitive drum 10 for each color after the transfer is cleaned by a cleaning device 19 which is a means for cleaning the image forming body for each color.

In synchronization with the formation of the superimposed color toner image on the transfer belt 14a, the recording paper P is transferred from the paper supply cassette 15 as the transfer material storage means via the timing roller 16 as the transfer material supply means to the second transfer. The superimposed color toner image on the transfer belt 14a is recorded by the secondary transfer device 14g, which is conveyed to a transfer area (no symbol) of the secondary transfer device 14g, which is a unit, and to which a DC voltage having the opposite polarity to the toner is applied. It is transferred onto the paper P at once. Y on the recording paper P
The transparent layer of T exists on the M, C, and K color toner images.

The recording paper P on which the color toner image has been transferred is
The charge is removed by a charge removing electrode 16b, which is a separating means formed of a sawtooth electrode plate, conveyed to the fixing device 17, and heat and pressure are applied between the fixing roller 17a and the pressure roller 17b, so that the recording paper P After the toner image is fixed,
It is discharged to a tray outside the device.

The untransferred toner remaining on the peripheral surface of the transfer belt 14a after the transfer is cleaned by a cleaning device 19a which is a transfer belt cleaning means provided opposite to the driven roller 14e with the transfer belt 14a interposed therebetween. .

The image forming apparatuses (IA) and (IB) having the image forming section E for forming the transparent toner (T) layer on the Y, M, C and K color toner images will be described with reference to FIGS. 1 and 3. explained. 2 and 4 show image forming apparatuses (IIA) and (II) showing other embodiments having the same effect.
FIG. 4B is a sectional configuration diagram of FIG. In the image forming unit E, Y,
Although the process units 100 for forming M, C, K, and T toner images are arranged in parallel in FIGS. 1 and 3, in the present embodiment, transfer is performed without an intermediate transfer member. The toner image is superimposed on the material. The image forming apparatuses (IIA) and (IIB) shown in FIGS. 2 and 4 correspond to the image forming apparatuses (IA) and (IB) shown in FIGS. Only the differences will be described. In image formation, the process unit 1
In synchronization with the toner image formation on
The recording paper P discharged from the printer is transported to the transport belt 14 via the timing roller 16.

The transported recording paper P is charged to the same polarity as the toner by the paper charger 14m, and the rotating transport belt 1 is rotated.
The Y toner image formed on the process unit 100 </ b> Y is transferred onto the recording paper P in close contact with the primary transfer device 1.
4c, on which the process unit 10
The M, C, K, and T toner images formed on 0M, 100C, 100K, and 100T are transferred in an overlapping manner, and a color toner image having the T toner layer as the uppermost layer is formed on the recording paper P. .

The recording paper P carrying the color toner image is neutralized by the separation electrode 14n, separated from the transport belt 14 and transported to the fixing device 17, where the color toner image on the recording paper P is fixed, and Discharge to an external tray.

Each of the image forming units E shown in FIGS. 1 and 2 has a configuration in which a transparent toner image is provided on a transfer material by superimposing a multi-layered color toner image by a tandem method. However, the present invention is not limited to this, and any image forming apparatus may be used as long as the color toner image and the transparent toner image transferred onto the transfer material are fixed.

Next, the developer used in the image forming apparatus of the present invention will be described. Both the color toner and the transparent toner are spherical toners having a weight average particle diameter of 3 to 10 μm, and polymerized toners by an emulsion polymerization association method are used. In the method for producing a polymerized toner by the emulsion polymerization association method, first, a colorant is dispersed in water using a surfactant. (A colorant is not used for a transparent toner.) On the other hand, a surfactant, an emulsion polymerization initiator, a styrene monomer and an acrylic monomer are added to water, and a resin emulsion is formed by emulsion polymerization. Next, the colorant dispersion and the resin emulsion are mixed and slowly aggregated while balancing the repulsive force of the particle surface generated by pH adjustment and the cohesive force due to the addition of the electrolyte. At the same time, by heating and stirring, fusion and shape control between the fine particles are performed.
The obtained particles are filtered, washed and dried to obtain a spherical toner having a weight average particle diameter of 3 to 10 μm.

The toner obtained by the emulsion polymerization association method thus obtained has a sharp particle size distribution and a small amount of fine powder, reduces toner contamination of the carrier, so-called toner spent, improves the durability of the developer, and improves the charge amount distribution. Is uniform, and a high quality image can be obtained as compared with a conventional pulverized toner.

The carrier is formed by forming a spherical ferrite particle having an average particle diameter of 40 μm and providing a coating layer of styrene resin having a thickness of 0.5 μm, and the toner is mixed with the carrier in an amount of 5 to 10% by mass. At the same time, 0.5% by mass of hydrophobic silica is added to form a developer.

In the image processing section of the present invention, r, g, b obtained by the color CCD 123 as shown in FIG.
A / D conversion (S2) of the amplified analog signal (S1)
To a digital signal of 8 to 10 bits for each pixel. Then, the light distribution characteristics are equalized by shading correction (S3), and the output luminance signal is subjected to complementary color conversion by density conversion (S4) to be converted into 256-level density information, followed by masking, UCR, and color. Color processing such as correction (S5) is performed. Generally, linear masking is used as masking, or non-linear masking or masking using a look-up table is used when performing advanced color correction. In the UCR, an operation of removing the gray component from the three color components and replacing it with black (K) is performed, and a process of improving the reproducibility of the shadow portion and the character portion is performed. Subsequently, the obtained image data is subjected to gamma correction (S6) for each toner, and after performing multi-value processing (S8),
Output to the exposure optical system 12 (S9), the photosensitive drum 1
A latent image is formed on 0.

In the image processing section of the present invention, in addition to the image processing corresponding to each color for forming the color toner image, a T exposure range for forming a transparent (T) toner image on the transfer material is set (S7). ) Circuit is provided,
The T exposure is performed by any one of the two methods (A) and (B) of (A) by specifying the formation area of the transparent toner layer and (B) by forming the transparent toner image on the color toner image. Will be

(A) By specifying the formation area of the T toner layer,
A process for providing a T toner layer in a designated area will be described.

Prior to image formation, pressing the T toner layer area setting button on the operation panel (not shown) sets the transparent toner area designation mode. (The transparent toner area may be a glossy area or a non-glossy area.) To specify an area, the area is placed at a specified position on the editor F shown in FIG. A T toner layer formation range is determined, and for example, a range (X1Y1, X2Y2, X
3Y3, X4Y4) using the light pen LP, the designated T toner layer formation range indicated by the oblique line is temporarily stored in the RAM in the T exposure range setting (S7) circuit.

By pressing the copy button, the image formation is started in the manner already described, and the exposure optical system 12T of the process unit 100T is used for the (X1Y1, X2Y2, X3Y3, X4Y4) toner layer forming range called from the RAM. Exposure is performed. The exposed latent image portion is subjected to reversal development by the developing device 13T,
After the transfer is performed, (X1Y1, X2Y2, X
3Y3, X4Y4), a toner layer is formed.

An image reading unit A is used instead of the editor F.
It is also possible to provide a discriminating means for discriminating the photograph area by detecting the gloss of the original, to discriminate the photograph area, and to set the transparent (T) exposure range based on the discrimination result. FIG. 7 shows this discriminating means, which comprises a light-emitting element and a light-receiving element, performs scanning simultaneously with or before reading a document, and sets a range in which the amount of light received by the light-receiving element exceeds a preset threshold value. Is the T exposure range.

(Embodiment 1) FIGS. 1 and 2 show an image forming apparatus (I) according to an embodiment of the present invention.
A), (IIA) and the process unit 10 shown in FIG.
This will be described using 0T.

The above transparent (T) process unit 10
0T denotes image units 50A and 5A composed of a charger 11, an exposure optical system 12, and a developing unit 13 on the peripheral surface of the photosensitive drum 10.
0B, and in the image forming apparatus (IA), the transfer belt 1 on the upstream side of each color process unit 100.
On the other hand, in the image forming apparatus (IIA), the image forming apparatus (IIA) is arranged so as to face the peripheral surface of the transport belt 14 on the downstream side of each color process unit 100.

The developing unit 13A included in the image unit 50A has a semi-gloss first transparent toner having a gloss of 5 ° to 20 ° which is almost the same as the color toner image after fixing. The developing unit 13B included in one of the image units 50B has the glossy second transparent toner having a higher glossiness of 20 ° to 50 °, and its rotation upstream side with respect to the peripheral surface of the photosensitive drum 10. The image units 50A and 50B or the image units 50B and 50A are arranged in this order.

Prior to the start of image formation, the area of the photographic image is specified by the above-described operation of the editor or the photographic area discriminating means, and then the gloss and semi-gloss of the area specified by the selection button on the operation panel of the apparatus main body. Alternatively, one of the gross modes is set.

At the start of image formation, in the image forming apparatus (IA), the formation of the transparent toner layer by the process unit 100T shown in FIG. 8A is first started.

That is, first, a semi-gloss transparent toner layer corresponding to the entire image area is formed in the image unit 50A.
Next, in the image unit 50B, a glossy transparent toner layer corresponding to only the designated or determined photographic image area excluding the character portion is formed to overlap. When the area of the photographic image is designated as a glossy surface, one or more transparent toner layers are formed, and when the area of the photographic image is designated as a semi-glossy surface, the exposure optical system 12 of the image unit 50B uses low exposure. And a transparent toner layer of less than one layer is formed in the photographic image area. When a gloss surface having a low gloss level is designated, the transparent toner layer is not formed by the image unit 50B.

Next, each color toner image is transferred to the transfer belt 1.
A color toner image is formed by superimposing sequentially on the transparent toner layer on 4a as a color toner image, and is recorded as a color image covered by a semi-gloss transparent toner layer as an uppermost glossy intermediate layer as shown in FIG. 8C. It is transferred onto paper P.

On the other hand, in the image forming apparatus (IIA), after a color toner image is formed by superimposing each color toner image on the recording paper P, the transparent toner formed by the process unit 100T shown in FIG. A layer is coated thereon and recorded as a color image, also shown in FIG. 8 (c).

As a result, by using a glossy transparent toner and a translucent toner having the same gloss as the color toner, the color image recorded on the recording paper P has a glossy image area with a good photographic area. By providing a semi-gloss transparent toner layer in the image area and also in the character area, the image can be freely formed into a semi-gloss gloss surface image without glare, and the quality as a color image is significantly improved. .

(Embodiment 2) Embodiments of each of the inventions according to claims 5 to 7 and claims 8 and 9 are shown in image forming apparatuses (IB), (IIB) and FIG. 9 shown in FIGS. This will be described with reference to the process unit 100T.

The above-mentioned transparent (T) process unit 10
0T is an image unit 50T including a charger 11, an exposure optical system 12, and a developing device 13T having a transparent toner on the peripheral surface of the photosensitive drum 10, and a charging device 11, an exposure optical system 12, and a developing device 13W having a white toner. Image unit 5 comprising
0 W, and in the image forming apparatus (IB), the transfer belt 1 on the downstream side of each color process unit 100.
On the other hand, in the image forming apparatus (IIB), the image forming apparatus (IIB) is disposed along the peripheral surface of the transport belt 14 on the upstream side of each color process unit 100.

The developing unit 13T of the image unit 50T
Indicates that the image after fixing has a transparent toner having the specified gloss level, and the developing unit 13W of the image unit 50W has a gloss level of 50 ° to 8 ° where the fixed image has a higher reflectance than the recording paper P.
It has a white toner that forms a white background of 0 °, and is arranged in order of the image unit 50W, then the image unit 50T or the image unit 50T and then the image unit 50W from the rotation upstream side of the peripheral surface of the photosensitive drum 10. .

After the start of image formation, the image forming apparatus (IB) forms a color toner image by superimposing the respective color toner images on the transfer belt 14a, and then transmits the image by the process unit 100T shown in FIG. 9A. The formation of the white toner layer is started following the toner layer.

That is, first, a transparent toner layer corresponding to the image area is formed in the image unit 50T, then a white toner layer corresponding to the image area is formed in the image unit 50W, and the white toner layer is superimposed on the transparent toner layer. It is formed together.

The white toner layer is provided for the purpose of supplementing the color tone and surface properties of the recording paper P. The thickness of the white toner layer is sufficient if it is 1.0 or more, and it is 2.0 or less. Is desirable. The transparent toner layer has a thickness of 1 to prevent the color toner from bleeding into the white toner layer at the time of fixing and to reduce the density of the color image.
With 0 to 2.0 layers, the color toner is mixed and fixed with the white toner to prevent the color tone from lowering.

On the other hand, in the image forming apparatus (IIB), a white toner layer is formed on the lowermost layer on the recording paper P and a transparent toner layer is formed thereon by the process unit 100T shown in FIG. Each color toner image is superimposed thereon and recorded as a color image.

As a result, light hitting the color image recorded on the recording paper P is reflected by the mat-like white toner layer, and light transmitted through the transparent toner layer and the color toner image thereon is directly reflected by the color toner image. The image is observed in addition to light, and a high-quality image with excellent coloring properties can be obtained.

The white toner layer and the transparent toner layer are used for forming a white toner image and a transparent toner image because even a slight fog or color mixture does not significantly affect the image quality of a color image. it can be set to the chargers 11 white toner and the transparent toner charge amount the chargers 11 by lower charging conditions than the charge amount Q ₂ of the color toners of Q ₁ is employed in the toner image formation of color due to that.

Generally, the charge amount Q ₂ of each color toner used for forming a color toner image is about ₂₀ to 35 μC / g. White used for forming the toner layer,
Charge to Q ₁ transparent toner it has been confirmed that the relationship of the charge amount Q ₂ to _{Q 2 -15 ≦ Q 1 ≦ Q} 2 -5 ( units [mu] C / g) is suitable to.

As a result, each of the white and transparent toners is inferior to the color toner in developing property and transferability. In particular, the color toner image is preferentially transferred even in the presence of the white toner and the transparent toner at the time of transfer. A clear color image can be obtained.

[0071]

According to the present invention, by using transparent toners having different gloss levels, a specified area of a document image, for example, a photographic image and a character image can be automatically or arbitrarily divided and the gloss level can be freely set. An image forming apparatus capable of recording and obtaining a desired high-quality image is provided (Claims 1 to 4). Further, an original image is formed by using a white toner and a transparent toner together with a color toner. An image which can be recorded as a color image with good color tone without color bleeding (claims 5 to 7), and which can be recorded as a color image with high adhesion of color toner and excellent sharpness (claims 8 and 9) A forming apparatus has been provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus (IA) according to a first embodiment.

FIG. 2 is a cross-sectional configuration diagram of the image forming apparatus (IIA) according to the first embodiment.

FIG. 3 is a cross-sectional configuration diagram of an image forming apparatus (IB) according to a second embodiment.

FIG. 4 is a cross-sectional configuration diagram of an image forming apparatus (IIB) according to a second embodiment.

FIG. 5 is a block diagram of an image processing system.

FIG. 6 is an explanatory diagram of area designation using an editor.

FIG. 7 is an explanatory diagram of a detection unit of a photograph area determination unit.

FIG. 8 is a configuration diagram of a process unit according to the first embodiment and an explanatory diagram showing a state of toner adhesion.

FIG. 9 is a configuration diagram of a process unit according to a second embodiment and an explanatory diagram illustrating a state of toner adhesion.

[Explanation of symbols]

 Reference Signs List 10 photoconductor drum 11 scorotron charger 12 exposure optical system 13 developing device 13A developing device (semi-gloss transparent toner) 13B developing device (glossy transparent toner) 13W developing device (white toner) 13T developing device (transparent toner) 14 transport belt 14a Transfer belt 14c Primary transfer device 14g Secondary transfer device 15 Paper cassette 16 Timing roller 17 Fixing device 19 Cleaning device 50 Image unit 100 Process unit D Original P Recording paper

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yotaro Sato 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA21 EA01 EA10 2H027 DB01 DB02 DE07 EA02 EB04 EC02 EC06 EC10 ED06 ED08 EE07 2H030 AA00 AB02 AD01 AD04 AD17 BB02 BB13 BB14 BB34 BB42 BB46

Claims (9)

[Claims] 1. An image forming apparatus in which a color toner image transferred onto a transfer material and a transparent toner layer are fixed to each other, wherein the transparent toner forming the transparent toner layer has two types of transparent toners having different gloss levels. An image forming apparatus comprising a toner. 2. The color toner has a glossiness of 5 ° to 20 ° after fixing.
°, wherein the first transparent toner has a gloss similar to that of the color toner after fixing, and the second transparent toner has a gloss of 20 ° to 50 ° after fixing. The image forming apparatus according to claim 1. 3. The method according to claim 1, further comprising a photographic image area determining unit, wherein the second transparent toner is formed on the color toner and the first transparent toner based on the determination result automatically obtained. Item 3. The image forming apparatus according to item 1 or 2. 4. The apparatus according to claim 1, further comprising a glossy image area designating unit, wherein the second transparent toner is formed in the designated area on the upper layer of the color toner and the first transparent toner. Image forming apparatus. 5. An image forming apparatus for forming a white toner layer and a color toner image on a transfer material, wherein a transparent toner layer is provided between the white toner and the color toner. 6. The image forming apparatus according to claim 5, wherein the white toner layer has a thickness of 1.0 or more. 7. The image forming apparatus according to claim 5, wherein the transparent toner layer has a thickness of 1.0 to 2.0 layers. 8. An image forming apparatus for forming a white toner layer, a transparent toner layer, and a color toner image on a transfer material,
In between the charge amount Q ₂ of the white toner and the charge amount Q _1, the color toner of the transparent toner, the image forming apparatus characterized by a relationship of Q ₁ <Q _2. 9. charge amount Q ₂ is a 20~35μC / g, in between the charge amount Q ₁ and a quantity of charge _{Q 2 Q 2 -15 ≦ Q 1} ≦ Q 2 -5 (unit [mu] C / g) The image forming apparatus according to claim 8, wherein the image forming apparatus has a relationship.