JPH01158453A - Image forming member and method and apparatus for forming image by using same - Google Patents

Abstract

PURPOSE:To enable a simple process color image to be formed by forming an organic photosensitive layer composed of a first electric charge generating layer and a second charge generating layer and a charge transfer layer formed between both layers. CONSTITUTION:The image forming member is obtained 1 by successively laminating on a support 2 a conductive layer 3, the organic photosensitive layer 4 consisting of the first charge generating layer (CGL) 4a, the charge transfer layer (CTL) 4b, the second charge generating layer (CGL') 4c formed in this order, and a dielectric layer 5. A first interlayer (BL) 6a is inserted between the conductive layer 3 and CGL 4a, and a second interlayer (BL') 6b is inserted between CTL 4b and CGL' 4c, thus permitting the obtained image forming member to be superior in abrasion resistance and weather resistance, low in cost, and the margin of the process conditions to be enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming member and an image forming method and apparatus using the image forming member. More specifically, the present invention relates to an organic photoreceptor used in electrophotography, and a color image forming method and apparatus using the organic photoreceptor.

[Conventional technology]

Conventionally, as an image forming member comprising an inorganic photoreceptor layer on a support and a dielectric layer laminated thereon, and a monochromatic image forming method using the image forming member, for example, IEEE TR
ANSACTIONS ON ELECTRON DE
VICES.

VOL, ED-19, No, 4. P396-P2O3,
APRIL, 1972 and IEEE TRANSACTI
O-NS ON ELECTRON DEVICES,
VOL, ED-19°No, 4. P2O3-P41
2. APRIL.

There is 1972.

In addition, as a color image forming method using an electrophotographic method, there is a method that has a large number of developing devices and one transfer drum, and transfers a toner image to a recording member on the transfer drum each time development is performed (hereinafter referred to as "transfer drum"). There is also a method (hereinafter referred to as - ) is called the bulk transcription method.

[Problem to be solved by the invention]

However, in an image forming member in which an inorganic photoreceptor layer is laminated on the support and a dielectric layer is laminated thereon, materials such as CdS and α-Se, which have low resistance, are used for the inorganic photoreceptor layer due to the image forming method. However, CdS, α-3e, has the disadvantage of being toxic, as is known.

Furthermore, in the transfer drum method, in order to obtain one color image, it is necessary to perform toner development on the image forming member multiple times, and therefore, compared to an image forming member used in a normal monochrome process, the image forming member is The disadvantage is that it has a short lifespan. Furthermore, since extremely high precision is required for positioning the toner and the recording member, there is a drawback that the mechanism becomes complicated. In addition, the above-mentioned batch transfer method requires multiple sets of exposure devices and development devices, making the device complicated and large.
Moreover, it has the disadvantage of being expensive.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks, and to
An object of the present invention is to provide a non-toxic image forming member that can form a color image in a simple process, and in addition, an image forming method and apparatus using the image forming member that is simple in structure, small in size, and capable of realizing a color image at low cost. Our goal is to provide the following.

[Means to solve the problem]

The image forming member of the present invention is an image forming member in which an organic photoreceptor layer is laminated on a conductive support and a dielectric layer is laminated thereon, in which at least the organic photoreceptor layer sandwiches a charge transport layer, It is characterized by consisting of a first charge generation layer and a second charge generation layer. Also, a first intermediate layer formed between the organic photoreceptor layer and the conductive layer, and a second intermediate layer formed between the charge transport layer of the organic photoreceptor layer and the second charge generation layer. It is characterized by having an intermediate layer of at least one of the following layers.

Further, the image forming method using the image forming member of the present invention includes a) a process of first charging the image forming member, and b) a first exposure at the same time as or immediately after the first charging. C) A process of performing a second charge with a polarity opposite to that of the first charge and the absolute value of the charge amount being smaller than the first charge amount, d) A process of performing a second exposure, e) A process of performing the first charge A process including developing toner charged to the same polarity as the charge is performed on toner of a different color, and then the toner is transferred and fixed onto the recording member, By the first exposure at the same time as or immediately after the first charging, charges are generated from the first charge generation layer of the organic photoreceptor layer of the image forming member, and by the second exposure, the organic photoreceptor layer of the image forming member is exposed to light. The second charge generation layer of the image forming member is characterized in that a charge is generated from the second charge generation layer of the body layer, or the second charge generation layer of the organic photoreceptor layer of the image forming member is Charges are generated from the charge generation layer of the image forming member, and charges are generated from the first charge generation layer of the organic photoreceptor layer of the image forming member by the second exposure.

Further, the image forming apparatus using the image forming member according to the present invention includes at least a first charging means that performs first charging around the image forming member, and a charger built in the first charging means. , a first electrifying means for performing a first exposure, which is placed immediately after the first charging means with respect to the process progress direction, or is placed on the opposite side of the first charging means with the image forming member in between. an exposure means, a second charging means that performs a second charge of opposite polarity to the first charge, which is installed rearward of the first exposure means in the direction of progress of the process; and a second exposure means for performing a second exposure, which is installed at the rear with respect to the progressing direction of the process and on the same side of the image forming member as the first charging means, or on the opposite side of the first charging means; It is characterized by comprising a plurality of toner developing means installed behind the second exposing means with respect to the process proceeding direction.

[Function] According to the configuration of the image forming member of the present invention, the charge generation layer is provided at three locations, that is, the first charge generation layer and the second charge generation layer are sandwiched between the charge transport layer. When selecting a material that allows the transport layer to transport positive polarity carriers, it is possible to transport positive polarity carriers in both directions of the organic photoreceptor layer by selecting which charge generation layer is used to generate carriers. It becomes possible. Similarly, in the case of a charge transport layer that transports negative carriers, it is possible to transport negative carriers in both directions of the organic photoreceptor layer.

Further, when the image forming member contains an intermediate layer, the intermediate layer exhibits a charge blocking or charge trapping function. In other words, when the first intermediate layer is provided between the organic photoreceptor layer and the conductive layer, it is possible to block the injection of charges having the same polarity as the first charge from the conductive layer, and the second charge generation layer When a second intermediate layer is included between the charge transport layer and the second charge generation layer, the charge trapped at the interface between the second charge generation layer and the dielectric layer is reversed to the charge transport layer. Injection can be blocked.

According to the structure of the image forming method and apparatus of the present invention, the first charging and the first exposure cause an equal amount to be applied to the surface of the dielectric layer of the image forming member and the interface between the organic photoreceptor layer and the dielectric layer. They hold charges of opposite polarity to each other, and then a second charging erases part of the charge on the surface of the dielectric layer, and a second exposure removes the charges on the surface of the dielectric layer, the organic photoreceptor layer, and the dielectric layer. It becomes possible to hold charges of equal amount and opposite polarity at the interface of the layers. This makes it possible to change the surface potential of the image forming member between areas where the second exposure was performed and areas where the second exposure was not performed, and this potential difference allows the toner to be developed. Furthermore, since the absolute value of the second charged charge amount is smaller than the absolute value of the first charged charge amount, as the process progresses, the surface of the image forming member always has the same polarity as the first charged charge. charge is present and, therefore, if the developed toner is charged to the same polarity as the first charge, it will have adhesion to the imaging member and will not come off the imaging member during the process. There is no scattering, so it is possible to transfer the developed toner all at once.

Further, according to the structure of the image forming method and apparatus of the present invention, when the charge transport layer of the organic photoreceptor layer of the image forming member is a hole transport type, and when the first charge is positive charge, the first charge transport layer is a hole transport type. The second charge generation layer is exposed to light by the exposure, and the first charge generation layer is exposed to light by the second exposure. In this case, the first exposure can be performed on the image forming member from the same side as the first charging means if the dielectric layer is transparent to the first exposure. However, if the conductive support and the first charge generation layer are transparent to the first exposure (no light absorption), the image forming member is charged from the side opposite to the first charging means. You can also do that. Similarly, when the conductive support is transparent to the second exposure, the second exposure can be performed on the image forming member from the side opposite to the first charging means. However, the dielectric layer and the second charge generation layer are
If the image forming member is transparent to the second exposure (no light absorption), the image forming member may be exposed from the side opposite to the first charging means. The same applies when the first charge is negatively charged and the charge transport layer is of the electron transport type.

〔Example] Hereinafter, the present invention will be explained in detail based on examples.

FIG. 1 is a schematic explanatory diagram of an image forming member according to the present invention, in which FIG. 1(a) is an image forming member that does not include an intermediate layer, and FIG. FIG. 1(c) is a schematic diagram of an imaging member containing a second intermediate layer, and FIG. 1(d) is a schematic diagram of an imaging member containing a first and second intermediate layer. It is an explanatory diagram.

The image forming member 1 includes a conductive layer 3, an organic photoreceptor layer 4, and a dielectric layer 5, which are laminated in this order on a support 2, and the organic photoreceptor layer 4 is a first charge generation layer (hereinafter referred to as CGL). )
4a, a charge transport layer (hereinafter referred to as CTL) 4b, and a second charge generation layer (hereinafter referred to as CGL') 4c are laminated in this order. Further, a first intermediate layer (hereinafter referred to as BL) 6a is inserted between the conductive layer 3 and the CGL 4a, and a second intermediate layer (hereinafter referred to as BL') 6b is inserted between the CGL 4a and the CGL 4a.
4b and CGL' 4c.

The support 2 may be a belt or drum made of an organic material such as polyester, polysulfone, polyimide, polycarbonate, etc.A1. A metal drum such as Cu (in this case, it can also serve as the conductive layer 3), a drum made of oxide, nitride, etc. can be used. As the conductive layer 3, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylamine, gum arabic, polyglutamic acid, polyvinyl chloride, polycarbonate, polyvinyl butyral, polystyrene, polyacrylate,
Thermoplastic resins such as polyester and cellulose resins,
Is it made by dispersing metal powder such as conductive carbon black or AI in a binder resin containing at least one type of resin selected from thermosetting resins such as EVO, xyresin, silicone resin, urethane resin, melamine resin, and alkyd resin? , a salt such as a quaternary ammonium salt, or A1. It is made by vapor-depositing and sputtering metal such as Cu. CGL4a and CGL'4c include phthalocyanine pigments, quinacridone pigments, polycyclic quinone pigments, benzidine pigments, azo pigments, perylene pigments, indigo pigments, squarylium pigments, ZnO pigments, TiO□ pigments, etc. It is made by vapor-depositing or dispersing in the binder resin a small amount of selected pigment (including at least one kind of pigment), or it is made by vapor-depositing or dispersing these in the binder resin, or it contains at least one kind of dye selected from azo dyes, perylene dyes, etc.
Alternatively, it is formed by being compatible with the binder resin. CG
Polyethylene glycol, hydroxypropyl cellulose, metal soap, etc. may be added to L4a and CGL' 4c for the purpose of improving pigment dispersibility. In addition, CGL4a%CGL'4c is each sensitivity wavelength,
In some cases, combinations with intentionally different absorption wavelengths are used, and in other cases, they are made of the same pigment. As CTL4b,
A polymeric charge transfer agent such as polyvinylcarbazole, methylphenylsilylene polymer, propylphenylsilylene polymer, or a hydrazone compound, triphenylmethane compound, carbazole compound, oxazole compound, oxadiazole compound,
It is formed by dissolving a compound containing at least one compound selected from low-molecular charge transfer agents such as benzidine compounds, stilbene compounds, bilazoline compounds, and triarylamine compounds. Halogenated paraffin, polyalkyl phthalate, silicone oil, etc. may be added to CTL4b for the purpose of improving plasticity. The dielectric layer 5 may be made of the binder resin, oxide, nitride, etc., or a composite thereof.

Preferably, a material with excellent weather resistance, abrasion resistance, and insulation properties, such as polycarbonate resin, is preferred;
, BL' 6b is made of the binder resin. However, if CTL4b is a hole transport type, BL
4a is particularly polyvinyl alcohol, polybenzyl alcohol, polyvinyl and lysine, polyallylamine, polyvinyl acrylic acid, hydroxypropyl cellulose,
A water-soluble resin such as gum arabic is preferable, and BL'4b
In particular, resins with insulating properties such as polystyrene with a high ratio of hole mobility to electron mobility, p-type semiconductors such as sulfide trimadal, or ionization smaller than CGL' 4c are used. It is preferable to use a material selected from charge transport materials having potential.

FIG. 2 is a schematic explanatory diagram of an image forming method and apparatus using the image forming member of the present invention.

The image forming member 1 rotating in the direction of the arrow lO force receives a first charge by a first charging means 11 and a first exposure from a first exposure means 12 simultaneously with the first charging, and is exposed to organic light. The resistance of the body 4 is reduced, and a charge having a polarity opposite to that of the first charge is induced at the interface between the dielectric layer 5 and the organic photoreceptor layer 4, and has a surface potential of vl.

(At this time, the amount of charge that falls onto the organic photoreceptor layer from the first charging means is defined as q.) Furthermore, the polarity is opposite to that of the first charge, and the absolute value of the charge amount is greater than the first charge amount. It receives a second charge by the second charging means 13 that performs a small second charge, and changes to a surface potential of v2. (At this time, the amount of charge falling onto the organic photoreceptor layer from the second charging means is assumed to be q'.) A second exposure means 14 that performs exposure corresponding to the image.
In the image forming member at the part exposed to the second light corresponding to the first color image, the resistance of the organic photoreceptor layer 4 becomes low again and the surface potential changes to v3. The surface of the imaging member in areas not exposed to light remains at v2.

In this way, a first color electrostatic latent image is formed.

FIG. 3 shows the state of charge stored in the image forming member 1 shown in FIG. 1(a) when the first charge is a negative charge, and FIG. 4 shows the state of charge accumulated in the image forming member 1 shown in FIG. FIG. 1(a) shows the change in surface potential of the image forming member 1 when
The same components are given the same symbols, + indicates a positive charge, - indicates a negative charge, and FIG. 3(a) shows the first charge,
The state of the image forming member l after the first exposure at the same time as the first charging, FIG. 3(b) shows the state after the second charging, and FIG. 3(c) shows the state of the image forming member l after the second exposure. The horizontal axis in FIG. 4 indicates the direction of process progress, and the vertical axis indicates the surface potential.

Of the developing devices arranged along the image forming member 1, a bias voltage (not shown) is applied only to the first color developing device 16a containing the first color toner 15a to perform toner development. . At this time, the bias voltage, toner charge amount, etc. are determined so that the toner is charged to the same polarity as the first charge and is developed on the image forming member l in the area where the second exposure was not performed. It will be done.

In this way, the development of the first color toner is completed, and the process of forming a second color latent image begins. First, the surface potential is raised to V again by first charging and first exposure at the same time as the first charging.
The surface potential is further set to v2 in the second zero-order charging, which is set to l. During the second exposure corresponding to the second color image, the image forming member 1 is located at a portion where the first color toner was not developed.
The surface potential of is V3, but in the area where the first color toner is developed, the effective thickness of the dielectric layer has increased by the amount of toner attached, and the surface potential is V3', which is slightly lower than V3. Becomes electric potential. At this time, the surface of the image forming member 1 that is not exposed to the second light remains at V2, and is charged to the same polarity as the first charge due to this potential difference V3-V2 or V3'-'V2. second color toner 15b
Development is performed by applying a bias voltage (not shown) only to the second color developer 16b. During the second color process, the dielectric layer 5 of the image forming member 1 is always charged with charges of the same polarity as the first charge (i.e.,
A charge of the same polarity as that of the first color toner) exists at the interface between the dielectric layer 5 and the organic photoreceptor layer 4 of the image forming member 1, and a charge of the opposite polarity to the first color charge (that is, There is a charge of opposite polarity to that of the first color toner. Therefore, during the second color process, the first color toner continues to adhere to the dielectric layer 5 of the imaging member 1 by electrostatic force. Further, if the potential difference V3' - V2 is sufficiently large (according to the authors' experiments, 200 V or more), it becomes possible to develop the second color toner in an overlapping manner.

In the case of the nth color, an electrostatic latent image is also formed in the above process, and toner development is performed by the nth color developer 16c containing the nth color toner 15c. During this series of processes, for the same reason as the process of forming a latent image of the second color, toners of up to the (n-1)th color continue to adhere to the dielectric layer 5 by electrostatic force. Further, the surface potential of the image forming member 10 at a portion where all the toners up to the n-1th color have been developed and which has received the second exposure corresponding to the image of the nth color is V 3 (n-11' If the potential difference V31''-11'-V2 is sufficiently large, it becomes possible to develop the n-th color toner in an overlapping manner.

In order to make the potential difference V3 ``-''' -V2 sufficiently large, various methods can be considered, but in particular, the authors have investigated the vacuum equivalent film thickness of each of the organic photoreceptor layer, dielectric layer, and developed toner layer. For example, potential difference V3''-th'-v2
If you try to make it more than 400v, the following formula
It is desirable to set process parameters to satisfy the following.

Vl-V2≦113*t ■Vl-V2≧4
00*t/lp ■t, ≧3.54
(2) t=t, +tl+tt where t9.1+ and t11 are the vacuum equivalent film thicknesses of the organic photoreceptor layer, dielectric layer, and developed toner layer, respectively.

In introducing the above equation, it is assumed that the charge q' accumulated at the interface between the dielectric layer 5 and the organic photoreceptor layer 4 due to the second charging is completely erased by the second exposure. In other words, q' was assumed to be smaller than the total amount of carriers generated in the organic photoreceptor layer. (In this simulation, it is assumed that the quantum efficiency of the organic photoreceptor layer is 15% and the light is irradiated at 10 erg/cm.) Here, only tt changes during the process. Also, if the toner potential difference (V3-V2 and V3''-'1'-V2) between the toner-adhered area and the toner-unadhered area is too far apart, the amount of development of the n-th color toner will be different between the three. It will be different. Therefore, it is desirable to make 11 as small as possible. To do this, the bias voltage should be set so that the amount of developed toner is one or two layers, or the specific inductivity of the toner should be increased, or the toner should be made as small as possible. It is desirable to take measures such as reducing the particle size.

After developing the n-th color toner, the transfer means 18 charges the recording member 2 with a polarity opposite to that of the first charging means 11 (that is, the toner is charged with a polarity opposite to that of the toner), and the recording member 2 moves in the direction of the arrow 19.
The toner is transferred to the recording member 20 by the fixing means 21, and a color image is created by fixing the toner to the recording member 20. After the toner transfer has been completed, the image forming member 1 is moved to a cleaning unit 22 to remove the toner remaining after transfer, and then enters the next color image forming process.

Here, as the toner, for example, cyan, magenta,
A pigment exhibiting yellow, black color, etc. is dissolved or dispersed in the binder resin, and if necessary, magnetic powder such as Fe5Oa or FeaOs, a charge control agent, a fluidity improver, and a cleaning agent are added. agents and fillers are added.

Regarding the developing device and the developing method, for the first color development, a method that contacts the image forming member l or a non-contact method may be used, but for the development of the second and subsequent colors, it is necessary to prevent contamination between toners. Therefore, non-contact methods are adopted. The methods of contact include -ingredients, or
There are two-component magnetic brush development method, pressure development method, fur brush development method, feed development method, etc. Non-contact methods include AC jumping development method, DC jumping development method,
A known developing method for electrophotography, such as powder cloud developability, is used.

As the charging means and transfer means, scorotrons, corotrons, etc., which are known in electrophotography, can be used, but scorotrons are preferable for the first charging means and the second charging means in order to keep the surface potential constant. Examples of means include halogen lamps, LEDs, xenon lamps, etc. known in electrophotography, laser writing systems, LCS arrays, LEDs, etc.
Arrays etc. can be used. Further, in this embodiment, corona transfer and heat roll fixing were used, but pressure transfer, adhesive transfer, pressure fixing, flash fixing, etc. may also be used.

Note that even when the image forming member of the present invention is used in an image forming method and apparatus using the so-called Carlson process, it is possible to obtain image quality comparable to that when using a normal laminated type or single layer type photoreceptor. can.

The present invention will be explained in more detail below.

[Example 1] Support 2, AI drum as conductive layer 3, 'CG L4a
As CTL4b, χ-type metal-free phthalicyanine, which has sensitivity in the near-infrared region, was dispersed in polyvinyl butyral resin at a weight ratio of 1:1, and laminated to a thickness of 0.4 μm.
As, tetraphenyldiaminodiphenyl was dissolved in polycarbonate resin at a weight ratio of 1:1, and 20 μm
As CGL' 4c, γ-type quinacridone having sensitivity in the visible range is dispersed in a polyester resin at a weight ratio of 1=1, and laminated to a thickness of 0.4 μm, and further, as a dielectric layer 5, 20μ polycarbonate resin
An image forming member (1) is obtained by laminating polyvinyl pyrrolidone to a thickness of 0.5 μm with BL6a between the conductive layer and CGL in the image forming member (1). 11) 6 image forming members (
In step 1), the image forming member (21) was made by laminating polystyrene to a thickness of 0.1 μm as BL'6b between the CTL and CGL'.
An image forming member (31) was prepared by laminating polyvinylpyrrolidone to a thickness of 0.5 μm as BL6a between the GL and laminating polystyrene to a thickness of 0.1 μm as BL'6b between the CTL and CGL'. .

These image forming members are incorporated into the apparatus shown in FIG.
The process up to the formation of a latent image was carried out to examine changes in the surface potential of the image forming member. However, at this time, although not shown in the figure, a surface electrometer was installed immediately before the second charging, immediately before the second exposure, and immediately before the first color developer. (below,
(each surface potential is x, y, z) Also, the C used
Since the TL is of the hole transport type, halogen lamp light cut to a wavelength of 500 na+ to 600 na+ is used as the first exposure means 12, and CGL' is used during exposure.
4c was exposed to light, and the surface potential (1) of the image forming member 1 after the first exposure was 800V. Also,
The surface potential V2 after the second charging was set to -200V. As the second exposure means 14, a laser writing system was used to expose the CGL 4a. The results are shown in Table 1.

Table 1 Image forming member (1) was incorporated into the apparatus shown in FIG. 2 to actually form a color image. However, the above-mentioned latent image forming conditions were adopted because if the amount of developed toner is for each color or two layers, then formulas (1) to (2) are satisfied.

The first color toner is a magenta color toner made by dispersing 10 wt percent of carmine 6B in a styrene-acrylic copolymer, and the second color toner is a magenta-colored toner made by dispersing 10 wt percent of carmine 6B in a styrene-acrylic copolymer.
A cyan color toner obtained by dispersing disazo yellow in a styrene acrylic copolymer was used as the third color toner, and a yellow color toner obtained by dispersing 15% disazo yellow in a styrene acrylic copolymer was used as a fourth color toner. A toner exhibiting a black color in which 8 wt % of furnace black was dispersed was used, and a DC jumping developer was used as the first to fourth color developers. In addition, the average charge amount q/m of each toner is 5
to 13 μC/g, and the average particle size of the toner is 10 μC/g.
μm, and the amount of toner to be developed was set to be two layers for each color.

After the fourth color toner is developed, a bias voltage (not shown) is applied to the corona transfer device of the transfer means 18, and the recording member 20 is irradiated with a corona having a polarity opposite to that of the first charging means 11.
The developed toner is transferred all at once onto the image forming member.

After that, by the heat roll fixing device of the fixing means 21,
The toner transferred onto the recording member 2° is fixed on the recording member. In addition, the image forming member that has completed toner transfer is
The cleaning unit 22 removes the toner remaining after transfer, and the first color image forming process begins.

Both the first and 1000th color images on the recording member produced in this manner were images with good color reproducibility and no background covering or background smearing.

[Example 2] Polycarbonate transparent drum as support 2, conductive layer 3
As CGL4a, a β-type copper phthalocyanine vapor deposited film was laminated to a thickness of 0.2 μm, and as CTL4b, a diphenylhydrazone compound was dissolved in a polycarbonate resin at a weight ratio of 1:0.8, and laminated to a thickness of 18 μm. , as CGL'4c, β-type copper phthalocyanine was dispersed in polybutyl methacrylate resin at a weight ratio of 1=1 and laminated to a thickness of 0.4 μm to form the dielectric layer 5.
The image forming member (2) is a 20 μm layered silicone resin layer, and the conductive layer and CGL are used as the image forming member (2).
0.5 sodium caseinate as BL6a between
The image forming member (12) is a layered material with a thickness of μm.In the image forming member (2), there is a B between the CTL and CGL'.
L'6b is an image forming member (21) made by dispersing sulfide tricylindrical in polyacrylonitrile at a weight ratio of 1:4 and laminating it to a thickness of 0.3 μm.0 Image forming member (2) is a conductive layer. Sodium caseinate is laminated to a thickness of 0.5 μm as BL6a between CTL and CGL.
An image forming member (32) is made by dispersing sulfide tricylindrical in polyacrylonitrile at a weight ratio of 1:4 and laminating it to a thickness of 0.3 μm as BL' 6b between the GL' and the BL' 6b.
And so.

This image forming member 1 is incorporated into the apparatus shown in FIG.
The process up to latent image formation was carried out, and changes in the surface potential of the image forming member were examined in the same manner as in Example 1. Note that the same components in the figure as in FIG. 2 are given the same symbols. Then, a fluorescent lamp is used as the first exposure means 12, and a first charging means 11 is used.
Except that the CGL'4c was exposed to light by the image forming member 1, and an LED array was installed inside the image forming member 1 as the second exposure means 14 to expose the CGL4a.
The same procedure as in Example 1 was carried out. The results are shown in Table 2.

The image forming member (22) was incorporated into the apparatus shown in FIG. 5 to actually form a color image. However, the above-mentioned latent image forming conditions were adopted because if the amount of developed toner is for each color or two layers, then formulas (1) to (2) are satisfied. Also,
The conditions for forming the latent image were the same as in Example 1.

The color image formed in this way is
Both the 0th image was an image with good color reproducibility and no background cover or background smudge.

Table 2 [Example 3] Polymethyl methacrylate transparent drum as support 2,
An ITO sputtered film was used as the conductive layer 3, and Rhodamine B was added as the CGL 4a in a polycarbonate resin at a weight ratio of 1:
1 and laminated to a thickness of 0.3 μm, and as CTL4b, polyvinylcarbazole was laminated to a thickness of 18 μm.
As CGL'4c, β-type steel phthalocyanine was dispersed in polycarbonate resin and polyvinyl butyral resin at a weight ratio of 2:1:1 and laminated to a thickness of 0.3 μm, and silicone resin was further layered to a thickness of 20 μm as a dielectric layer. The laminated product was used as an image forming member (3). In the image forming member (3), BL6a was used between the conductive layer and CGL, and nylon was used as BL6a. CTL was performed using the image forming member (3) with the image forming member (13) laminated to a thickness of 1 μm.
and CGL', as BL' 6b, tetraphenyldiaminostilbene is added to polycarbonate at a weight ratio of 1:
The image forming member (23) was made by dispersing the particles so that the nylon particles were dispersed and laminated to a thickness of 2 μm.In the image forming member (3), 0.1 nylon was dispersed as BL6a between the conductive layer and the CGL.
Laminated to a thickness of μm, BL' is placed between CTL and CGL'.
As 6b, tetraphenyldiaminostilbene was dispersed in polycarbonate at a weight ratio of 1=1.
An image forming member (33) was obtained by laminating the layers to a thickness of μm.

These image forming members are incorporated into the apparatus shown in FIG.
The process up to latent image formation was carried out, and changes in the surface potential of the image forming member were examined in the same manner as in Example 2, except that vl was 600 V and v2 was -170 V. The results are shown in Table 3.

Table 3 The image forming member (33) was incorporated into the apparatus shown in FIG. 5 to actually form a color image. However, the above-mentioned latent image forming conditions were adopted because if the amount of developed toner was one to two layers for each color, the formulas (1) to (2) would be satisfied. Also,
The conditions for forming the latent image were the same as in Example 1.

The color image formed in this way is
Both the 0th image was an image with good color reproducibility and no background cover or background smudge.

[Example 4] Image forming member (2) used in Example 2 and an image forming member in which polyvinyl butyral resin was laminated as BL6a between the conductive layer and CGL to a thickness of 0.5 μm. (14), and CTL and C with the image forming member (2).
An image forming member in which polyvinyl butyral resin is laminated to a thickness of 0.5 μm as BL' 6b between the GL' and the BL' 6b.
24) and 0.5% polyvinyl butyral resin as BL6a between the conductive layer and CGL in the image forming member (2).
Laminated to a thickness of μm, BL' is placed between CTL and CGL'.
6b is polyvinyl butyral resin with a thickness of 0.5 μm.
The thickly laminated image forming member (34) was assembled into the apparatus shown in FIG. 6, and the process up to forming a latent image was performed to examine changes in the surface potential of the image forming member. In addition, the second
Components that are the same as those in the figures are given the same reference numerals. however,
With Vl set at -800V and V2 set at 200V, light is irradiated from the support side of the image forming member by the first exposure means 12.
GL4a was exposed to light, and CGL'4c was also exposed by second exposure means 14. The results are shown in Table 4.

Table 4 The image forming member (34) was incorporated into the apparatus shown in FIG. 6 to actually form a color image. However, the above-mentioned latent image forming conditions were adopted while satisfying formulas (1) to (2) if the amount of developed toner was one to two layers for each color. Also,
As the first color toner, 15 wt% of Banza Yellow 5G was dispersed in styrene-butadiene copolymer.
Furthermore, a toner exhibiting a yellow color with 0.5 wt percent of hydrophobic silica externally added was used as a second color toner, and 12 w of quinacridone was added to a styrene-butadiene copolymer.
t percent dispersed, and additionally 0.5% hydrophobic silica
A toner exhibiting a magenta color with wt% added externally,
As the third color toner, a cyan toner obtained by dispersing 1 owt percent of indanthrembule in a styrene-butadiene copolymer and externally adding 0.5 wt percent of hydrophobic silica was used as the fourth color toner. As a toner, a toner having a black color was used in which 10 wt % of furnace black was dispersed in a styrene-butadiene copolymer and 0.5 wt % of hydrophobic silica was externally added. The average charge amount q/m of each of the above toners is -
The average grain size was 7 to 9 μm.

After the fourth color toner is developed, a bias voltage (not shown) is applied to the corona transfer device of the transfer means 18, and the recording member 20 is irradiated with a corona having a polarity opposite to that of the first charging means 11.
The toner imaged on the image forming member is transferred all at once. Thereafter, the toner transferred onto the recording member 20 is fixed onto the recording member by the heat roll fixing device of the fixing means 21. Further, after the toner transfer has been completed, the image forming member has the remaining toner removed by the cleaning unit 22, and then enters the next color image forming process.

The color image formed in this way is
Both the 0th image was an image with good color reproducibility and no background cover or background smudge.

[Example 51 The same procedure as in Example 4 was performed except that the average particle size of the toner was controlled to 12.1 O 19.8 μm for each of the first, second, third, and fourth colors. Color images with better efficiency and better color reproducibility were formed.

[Example 6] The average particle size of the toner was 10 μm, the average charge amount q/m of the first color toner was -5 μC/g, and the average charge amount q/m of the other toners was -8 to -1 OuC/g. When the same procedure as in Example 4 was carried out except for the above, a color image with even better color reproducibility was formed.

[Example 7] Image forming member (1), image forming member (11), image forming member (21), and image forming member (31) were incorporated into an image forming apparatus using a so-called Carlson process.
The surface potential was set to -900 V by initial charging, and main exposure was performed using a laser writing system to expose the CGL. The surface potential of the exposed area was -450V. Toner development was performed by this potential difference, and the developed toner was transferred and fixed onto the recording member. After fixing, the surface potential of the image forming member is set to zero by AC corona charge removal, and the CGL' is exposed to light through the entire surface to cancel out the electric charge at the interface between the CGL' and the dielectric layer, and the image forming member is returned to its initial state.

The images created in this way were of good quality.

〔Effect of the invention〕

As described above, the image forming member according to the present invention is
In an image forming member in which an organic photoreceptor layer is laminated on a conductive support and a dielectric layer is laminated thereon, at least the organic photoreceptor layer has a charge transport layer in between, and a first charge generation layer and a second charge generation layer. This feature makes it possible to transport positive (or negative) carriers generated in the charge generation layer not only in one direction but also in both directions of the organic photoreceptor layer. , the positive polarity generated by the second exposure (
Alternatively, negative polarity (or positive polarity) existing at the interface between the organic photoreceptor layer and the dielectric layer due to carriers of negative polarity
It became possible to cancel out part of the electric charge. This has made it possible to provide an inexpensive image forming member with excellent abrasion resistance and weather resistance.

The image forming member according to the present invention also includes a first intermediate layer formed between the organic photoreceptor layer and the conductive layer, and a first intermediate layer formed between the charge transport layer and the second charge generation layer of the organic photoreceptor layer. The second intermediate layer formed in .

The image forming method using the image forming member according to the present invention includes:
a) a first charging process on the imaging member; b
) A process in which the first exposure is performed simultaneously or immediately after the first charging; C) A process in which the second charging is performed with the opposite polarity to the first charging and the absolute value of the charge amount is smaller than the first charge amount. , d) a process of performing a second exposure, and e) a process of developing the toner charged to the same polarity as the first charging, and then applying the process to the toner of a different color, and then applying the process to the recording member. Since the toner is transferred and fixed, a charge having a polarity opposite to the first charge is always present at the interface between the organic photoreceptor layer and the dielectric layer of the image forming member during the progress of the process; Since there is no charge of opposite polarity to the first charge on the surface of the dielectric layer of the image forming member, it is possible to retain the developed toner on the image forming member. Therefore, it becomes possible to transfer the developed toner all at once. This simplifies configuration and
It is possible to create a color image with good image quality without image unevenness or color shift.

An image forming apparatus using the image forming member according to the present invention includes:
At least a first charging means for performing first charging around the image forming member;
A first exposure device that performs a first exposure that is placed immediately after the first charging device in the process progress direction, or is placed on the opposite side of the first charging device with the image forming member in between. means, a second charging means that performs second charging of opposite polarity to the first charging, which is installed rearward in the process progress direction than the first exposure means, and the process advances further than the second charging means. a second exposure means for performing a second exposure, which is installed at the rear with respect to the direction and on the same side as the first charging means or on the opposite side of the image forming member; the second exposure means; It is characterized by a plurality of toner developing means installed at the rear with respect to the direction of process progress, so the structure is simple, small, portable, inexpensive, and provides good color image quality with no image unevenness or shift. Images can now be created.

It goes without saying that these image forming members, image forming methods using the image forming members, and image forming apparatuses using the image forming members can be widely applied to image forming apparatuses such as printers and copying machines. In addition, it is not limited to color images.
It can also be used for monochrome image formation.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an image forming member in the present invention. FIG. 2 is a schematic explanatory diagram of an image forming method and apparatus using the image forming member according to the present invention. FIG. 3 is a diagram showing the state of charge stored in the image forming member 1 when the first charge is a negative charge in the image forming method and apparatus using the image forming member according to the present invention. FIG. 4 is a diagram showing changes in the surface potential of the image forming member 1 when the first charge is set to be a negative charge in the image forming method and apparatus using the image forming member according to the present invention. FIG. 5 is a schematic explanatory diagram of an image forming method and apparatus using the image forming member according to the present invention. FIG. 6 is a schematic explanatory diagram of an image forming method and apparatus using the image forming member of the present invention. 1... Image forming member 4... Organic photoreceptor layer 5... Dielectric layer 11... First charging means 12... First exposure means 13... Second charging means 14 ...Second exposure means and above Fig. 1 71 I^ α νI tog gauze Fig. 2 111 ---=-=;==--2::=N2
~2 ~2 (a) (b) (c) Third
Figure 4

Claims (6)

[Claims] (1) In an image forming member in which an organic photoreceptor layer is laminated on a conductive support and a dielectric layer is laminated thereon, at least the organic photoreceptor layer has a charge transport layer sandwiched therebetween, and a first charge generation layer. and a second charge generation layer. (2) A first intermediate layer formed between the organic photoreceptor layer and the conductive layer, and a second intermediate layer formed between the charge transport layer and the second charge generation layer of the organic photoreceptor layer. The image forming member according to claim 1, further comprising at least one intermediate layer. (3) A process of performing a) first charging on the image forming member according to claim 1, b) a process of performing first exposure at the same time or immediately after the first charging, and c) a process opposite to the first charging. d) A process of performing a second exposure; e) A process of performing a second charge of polarity and an absolute value of the charge amount smaller than the first charge amount; e) A process of performing a second charge of the toner charged to the same polarity as the first charge An image forming method comprising performing a process including a developing process on toners of different colors, and then transferring and fixing the toners onto a recording member. (4) By the first exposure at the same time as or immediately after the first charging, charges are generated from the first charge generation layer of the organic photoreceptor layer of the image forming member, and by the second exposure, the image 4. The image forming method according to claim 3, wherein charges are generated from a second charge generation layer of the organic photoreceptor layer of the forming member. (5) By the first exposure at the same time as or immediately after the first charging, charges are generated from the second charge generation layer of the organic photoreceptor layer of the image forming member, and by the second exposure, the image 4. The image forming method according to claim 3, wherein the charge is generated from the first charge generation layer of the organic photoreceptor layer of the forming member. (6) At least a first charging means for performing first charging around the image forming member according to claim 1, which is built in the first charging means, or is a part of the process of the first charging means. a first exposure means for performing a first exposure, which is placed immediately behind the first charging means with respect to the traveling direction, or placed on the opposite side of the first charging means with the image forming member in between; a second charging means for performing a second charge of the opposite polarity to the first charging, which is installed rearward in the direction of progress of the process than the second charging means; and on the same side of the cylinder image forming member as the first charging means;
Alternatively, it is characterized by comprising a second exposure means installed on the opposite side for performing the second exposure, and a plurality of toner developing means installed behind the second exposure means with respect to the process progress direction. image forming device.