JP2000267451A - Image recorder and intermediate transfer body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To steadily form a nip at a low cost by a simple processing by providing at least one of one or more intermediate transfer bodies with a cylindrical support body and an elastic layer formed on the cylindrical face of the support body, and forming slits which turn round the support body, in both ends of the elastic layer. SOLUTION: In an intermediate transfer drum 110, a rubber elastic layer 203 with slits 203a for the formation of stable transfer area is formed on a cylindrical support member 204, further, an intermediate layer 202 for the prevention of a leak is formed on the rubber elastic layer 203, and, further, a surface layer 201 with high toner releasability is formed on the intermediate layer 202. The slits 203a, which turn around the support member 204, are made in both ends of the rubber elastic layer 203, thereby substantially thinning both the ends of the rubber elastic layer 203 and, therefore, decreasing the maximum outside diameter of a raised part which is made in the rubber elastic layer 203.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus used for an electrophotographic recording apparatus, an electrostatic recording apparatus, ionography and the like.

[0002]

2. Description of the Related Art An image recording apparatus employing an electrophotographic system is of a type using an intermediate transfer member, that is, an electrostatic latent image carrier uniformly charged by a charging unit is statically charged by an image writing unit. An electrostatic latent image is formed, a toner image is obtained by attaching toner particles to the electrostatic latent image, the toner image is primarily transferred to an intermediate transfer member by a first transfer unit, and further formed on the intermediate transfer member. There is a type in which a recorded image is secondarily transferred to a recording sheet or the like by a second transfer unit, and then the toner image on the recording sheet or the like is fixed to obtain a recorded image.

[0003] The intermediate transfer member used in this type of image recording apparatus is, for example, of a cylindrical shape. A pipe serving as a support for an elastic layer is previously set in a cylindrical mold, and the outer surface of the pipe is connected to the mold. It is made by injecting and molding a rubber material between the inner surfaces. This intermediate transfer body is further intermediately used for transferring the toner image from the electrostatic latent image carrier and for holding the toner image intermediately. Various characteristics are required to transfer the toner image on the transfer body to the next recording medium.

For example, an electrostatic latent image carrier having a cylindrical shape and an intermediate transfer member having a cylindrical shape are pressed against each other, and the toner image formed on the electrostatic latent image carrier is The image is transferred onto the intermediate transfer body via a contact area (hereinafter, referred to as a nip area) formed between the latent image carrier and the intermediate transfer body.

Since the quality of these transferred images is affected by the width (nip width) of the nip area in the process direction and the pressing force, the nip width and the pressing force are made uniform to form a high-quality transferred image. There is a need. FIG. 8 is a cross-sectional view of a conventional intermediate transfer body in a rotation axis direction.

Here, a drum type intermediate transfer body 10 having a rubber elastic layer 12 coated on a metal shaft 11 and a coat layer 13 thereon is shown.

However, the outer diameter of the intermediate transfer body 10 having the rubber elastic layer 12 has an outer diameter at both ends due to heat shrinkage in a molding step or a secondary vulcanization step or processing distortion in a polishing step. The raised portion 14 is larger than the outer diameter of the central portion and has a convex shape shown in FIG.

When the intermediate transfer member 10 having the rising portion 14 as described above is pressed against the electrostatic latent image carrier, the nip width at the center is smaller than the nip width at the end due to the difference in outer diameter. Failure occurs.

Further, since the stress generated in the rising portion 14 is higher than that in the central portion, a portion of the member such as an electrostatic latent image carrier which comes into contact with the intermediate transfer member is more likely to be worn than the central portion. Member life is shortened.

Furthermore, when a bias voltage is applied to the intermediate transfer member and used, a defect is generated on the surface layer of the rising portion where the pressing force is large due to abrasion and cracking, and a current leak occurs at the defective portion. In an image recording apparatus using an intermediate transfer member having a rising portion at an end, image loss such as poor transfer or uneven transfer may occur.

Normally, an intermediate transfer member having such a rising portion is used after being polished so as to have substantially the same outer diameter at the center. However, the disadvantage that the cost is increased due to the additional polishing step. is there.

The hardness of the rubber elastic layer of the intermediate transfer member is
To form the nip width with low pressing force, it is required to have low hardness, but as the rubber hardness decreases, the rubber elastic layer becomes softer, and as a result, the roughness of the polished surface increases, and it is transferred to the surface The resulting toner image is disturbed.

As a method for improving the problem caused by the rising of the end portion of the rubber elastic body, Japanese Patent Laid-Open No. 04-33 is disclosed.
6561, JP-A-04-336562, JP-A-09-258584, and JP-A-02-2822.
There is a case proposed in JP-A-83.

JP-A-04-336561 and JP-A-04-336562 disclose, in order to obtain a uniform nip width, an elastic layer at the center of a roll or a central portion of a shaft inserted into an elastic body. A rubber roll used as a so-called crown-shaped development carrier has been proposed. A roll having such a crown shape is obtained by installing a cylindrical shaft in a mold in which the inner surface of the mold is processed into a crown shape, putting a rubber material therebetween, and forming a roll having the shape shown in FIG. Molded. Alternatively, it is made by inserting a cylindrical rubber material 12 into a crown-shaped shaft 11 shown in FIG. However, these rolls have a disadvantage that the cost is high because the shaft and the mold are formed into a non-rectangular cylindrical shape which is difficult to machine.

Further, Japanese Patent Application Laid-Open No. 09-258584 discloses that, as shown in FIG. 11, the shaft diameter d at the rising portion is reduced, and the rubber elastic layer thickness at that portion is reduced. A rubber roll for electrophotography has been proposed in which a thicker rubber elastic layer absorbs excess stress at the end portion caused by pressing by making it thicker to form a uniform nip width. In this roll, since a small diameter portion is provided on the shaft 11, the rubber thickness of this portion becomes thicker than other portions of the roll, and a difference in sink due to molding shrinkage at the time of molding processing occurs, making it difficult to control the outer diameter. Further, since the roll has a non-adhesive area in part, there is a concern that the non-adhesive area is partially deteriorated during use due to repeated compression movement. Furthermore, problems such as an increase in the amount of rubber material used and an increase in cost are caused.

Japanese Patent Application Laid-Open No. 02-282283 proposes a fixing device roll in which a surface layer is formed around a cored bar through a sponge layer. In this roll, a large number of through holes or spiral through holes are provided in the sponge layer around the core bar in parallel with the axial direction of the core bar. The through-hole has been proposed as having the purpose of promoting the diffusion of gas inside the bubbles forming the sponge layer and reducing the difference in outer diameter in the roll axis direction due to heat. Not.

As described above, various proposals have been made relating to the improvement of the outer diameter accuracy of the rubber roll. However, in practice, an inexpensive and practical intermediate transfer member having a uniform outer diameter has not been obtained. is there.

[0018]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an intermediate transfer member having a uniform outer diameter, which is inexpensive, easy to process and can form a stable nip, and an intermediate transfer member thereof. To provide an image recording apparatus.

[0019]

According to the image recording apparatus of the present invention which achieves the above object, an electrostatic latent image is formed on a surface and the electrostatic latent image is developed with toner to carry a toner image on the surface. An image carrier, and one or more intermediate transfer members that receive the transfer of the toner image onto the surface at a predetermined primary transfer position while rotating and then transfer the transferred toner image at a predetermined secondary transfer position. Finally, in an image recording apparatus for forming an image on a recording medium by transferring a toner image onto a predetermined recording medium and fixing the toner image on the recording medium, At least one of the intermediate transfer members has a cylindrical support and an elastic layer formed on a cylindrical surface of the support, and slits are formed on both end surfaces of the elastic layer so as to orbit the support. It is characterized by becoming.

Here, in the image recording apparatus of the present invention, the slit may be formed at a portion of both ends of the elastic layer in contact with the support, or the slit may be formed at both ends of the elastic layer. It may be formed on the surface at a position away from the support.

In the image recording apparatus of the present invention, the elastic layer is preferably an elastic layer having a thickness of 3 mm or more and 8 mm or less and a hardness of JIS-A of 15 degrees or more and 35 degrees or less. Is preferably a slit having a depth of 5 mm or more and 30 mm or less in the direction from each end face to the other end face.

Further, the intermediate transfer member of the present invention, which achieves the above object, receives the transfer of the toner image at a predetermined primary transfer position while rotating, and transfers the transferred toner image at a predetermined secondary transfer position. The intermediate transfer member to be transferred has a cylindrical support and an elastic layer formed on the cylindrical surface of the support, and slits orbiting the support are formed on both end surfaces of the elastic layer. It is characterized by.

[0023]

Embodiments of the present invention will be described below.

FIG. 1 is a block diagram of an embodiment of the image recording apparatus of the present invention.

The surface of the electrophotographic photosensitive member 101 formed by applying a photosensitive material on an aluminum pipe is charged to the charger 1
02 and then the writing device 104a
Scanning exposure light 104b emitted from the device according to the image information
Thereby, an electrostatic latent image is formed on the surface of the photoconductor. This electrostatic latent image is developed and visualized by the developing unit 105a of the developing unit 105 corresponding to the color information of the electrostatic latent image formed this time.

The visualized toner image is transferred from the electrophotographic photosensitive member 101 to the surface of the intermediate transfer drum 110 in a transfer area P ₁ where the electrophotographic photosensitive member 101 and the intermediate transfer drum 110 are in contact with each other. The image is transferred by applying a voltage between the transfer drum and the photoconductor. The surface of the photoreceptor after the transfer is irradiated with light from a discharge lamp 108 to be discharged, and the toner remaining on the surface of the photoreceptor is removed by the cleaning device 103.

The above process is repeated a plurality of times, and each time a developing device 105b having a developer of a different color according to the image information,
Developed and visualized by 105c and 105d, and sequentially transferred and laminated from the photoreceptor surface to the intermediate transfer drum 110,
A plurality of toner images are laminated on the surface of the intermediate transfer drum.

The color toner image laminated and formed on the surface of the intermediate transfer drum is transported by a paper transport roll 109, and is transferred to the intermediate transfer drum 110 and to a metal shaft by 10 ^8.
The recording material 11 located between the transfer roll 106 and the transfer roll 106 formed by coating an elastic body having a resistance value of about Ω
In the contact area with the transfer roller 1, transfer is performed from the surface of the intermediate transfer drum to the surface of the recording material at once by the voltage applied between the intermediate transfer drum 110 and the transfer roll 106. A peeling charger may be used instead of the transfer roll. further,
A transfer roll may be used and a peeling charger may be provided near the transfer area.

The toner image collectively transferred to the surface of the recording material is conveyed to a fixing device 107, where the fixing device 10
7 is fixed.

Next, the intermediate transfer drum of the present invention will be described with reference to the configuration diagrams shown in FIGS.

FIG. 2 is a schematic view of the intermediate transfer drum employed in the image recording apparatus shown in FIG. 1, and FIG. 3 is a side view of the intermediate transfer drum.

In the intermediate transfer drum 110 of the present embodiment, a rubber elastic layer 203 having a slit 203 a for the purpose of forming a stable transfer area on a support member 204 is formed. An intermediate layer 202 for preventing leakage is formed on the
2, a surface layer 201 having a high toner release property is formed.

Next, each layer will be described.

The support member 204 of the intermediate transfer member is formed by a drum formed by machining a cylindrical aluminum tube by machining or a seamless roll formed by bending a stainless steel plate into a cylindrical shape and welding these joints by laser processing. What was done can be mentioned as an example.

The function required for the support member 204 is that a rubber elastic layer 203 having a slit 203a and an intermediate layer 202 are provided.
And to maintain a predetermined shape by supporting the surface layer 201, and by a machining process such as lathing and polishing and a shaping process such as a drawing process and a drawing process, as long as the conductive material can be easily processed, There is no restriction on the material or processing method.

The main function required for the rubber elastic layer 203 is that the electric charge supplied through the support member 204 is transferred to the intermediate layer 20.
2 and the conductivity required for transmission to the intermediate transfer body 110
The hardness required to form a stable transfer area, ie, a nip area, between the member and the contacting member, and the outer diameter uniformity required to form a uniform nip width in the entire axial direction.

In an image recording apparatus using the intermediate transfer body 110 having the rubber elastic layer 203, the thickness and hardness of the rubber elastic layer required to form a desired nip width are 3 mm or more. 8mm or less and JIS
-A hardness is 15 degrees or more and 35 degrees or less. If the thickness of the rubber elastic layer exceeds 8 mm, unevenness occurs in the circumferential speed, and the image quality of the toner transferred on the intermediate transfer member is disturbed. If the thickness of the rubber elastic layer is less than 3 mm, a desired nip width cannot be formed. Also,
When a rubber elastic layer is formed using a rubber material having a JIS-A hardness of less than 15 degrees, a desired nip width can be obtained, but photoconductor contamination due to the influence of low molecular weight components added to the rubber composition to lower the rubber hardness. In the case of an intermediate transfer body having a surface layer formed on an elastic layer, the surface layer is peeled off, or the outer layer is peeled off due to long-term storage.

If the JIS-A hardness exceeds 35 degrees, a desired nip cannot be formed.

The resistance value of the rubber elastic layer 203 is preferably low in order to form an effective transfer electric field with a low applied voltage, and the resistance value of the rubber material is 10 ⁸ Ωcm or less, preferably 10 ⁵ Ωcm.
cm or less.

As a rubber material having these characteristics, a non-foamed liquid silicone rubber is desirable because of its low hardness, good compression set characteristics and quick deformation recovery force.

The rubber elastic layer 203 is formed by casting and transfer molding using these rubber materials. However, the rubber elastic layer 203 is not limited to these as long as the above characteristics are satisfied.

When slits orbiting around the support member 204 as shown in FIGS. 2 and 3 are formed at both ends of the rubber elastic layer 203 having the above characteristics, both ends of the rubber elastic layer become substantially thin. The maximum outer diameter of the rising portion generated in the rubber elastic layer can be reduced. Further, even if a rising portion of the rubber elastic layer occurs at the end, the rubber elastic layer on the outer periphery of the slit is easily deformed toward the center of the support member, so that the intermediate transfer body 110 is pressed against the cylindrical photosensitive member. However, a uniform nip width can be formed without generating a high pressure portion at the end of the elastic layer.

Next, the slit dimensions will be described.

If the length of the slit in the longitudinal direction, that is, the direction from each end face to the other end face is 5 mm or less, the effect of the end rising portion remains, and a uniform nip cannot be formed. In the range of the hardness and thickness of the rubber elastic layer described above, the length of the rising portion of the rubber elastic layer in the longitudinal direction is 30 mm or less, and the size of the slit for forming a uniform nip is set at the end. The length of the rising portion may be sufficient. If the length of the slit is 30 mm or more, it is necessary to increase the length of the rubber elastic layer in the longitudinal direction in order to secure the paper passage area, which increases the cost.

The size of the slit, that is, the slit width in the radial direction, is a value obtained by subtracting the outer diameter of the center portion of the rubber elastic layer from the maximum outer diameter at the rising portion of the rubber elastic layer having no slit. (Maximum rising amount) is set. With a slit smaller than the maximum rising amount, the rubber elastic layer on the outer layer of the slit does not have sufficient mechanical deformation, so that uniformity of the nip width cannot be obtained.

The essential point of the intermediate transfer member is that the stress generated at the rising portion is absorbed not by the compression deformation of the rubber elastic layer but by the mechanical deformation by having a structure having slits. .

Therefore, the shape of the slit may be any shape other than that described above, as long as the rubber elastic layer at the rising portion of the roll end when the pressure is applied absorbs the generated stress by being mechanically deformed. There may be.

Next, the intermediate layer 202 will be described.

The intermediate layer 202 has good adhesion to both the rubber elastic layer 203 and the surface layer 201 in order to prevent the separation of the surface layer 201 and the rubber elastic layer 203. Good film forming workability is required to form a uniform layer having no coating film defects for conductivity and for preventing leakage for transmitting the applied voltage to the surface layer 201. Furthermore, it is essential to have rubber elasticity,
Desirably, the hardness of one of the rubber elastic layer 203 and the surface layer 201 is lower than that of the higher hardness layer, and higher than the hardness of the other lower hardness layer, that is, the rubber has an intermediate hardness between the rubber elastic layer and the surface layer. As a specific material used for the intermediate layer 202, an organic solution in which a fluororubber is dissolved is desirable in order to obtain an affinity with the surface layer 201 formed of a fluorine-based material.

These materials may be used alone, but conductive particles such as carbon black and metal oxide, surfactants capable of dispersing molecules which are less likely to self-aggregate, and ionic conductive materials such as quaternary ammonium salts. May be added to adjust the resistance value. As a forming method, dipping or spray coating is preferable in terms of productivity.

Further, characteristics of the surface layer 201 will be described.

It is an essential condition that the surface material has good toner releasability in order to obtain a high transfer rate, in particular, to easily release and transfer the lower layer toner of the toner image formed on the intermediate transfer member 110. .

As a material for this purpose, a urethane paint in which a fluororesin is dispersed, a fluorine-based aqueous paint in which a fluororesin is dispersed, or a fluororesin film is desirable.
Specifically, the surface layer may be formed with GLS213 manufactured by Daikin Industries, Ltd., or FC1100 in which fluorinated carbon black is added to fluororubber latex containing fluororesin particles.

Next, a method for manufacturing a slit will be described.

As shown in FIG. 4, the casting mold used for forming the slit is composed of two base plates 3.
01, 302, two intermediate plates 303, 304, and a cylindrical main body 305. The intermediate plates 303, 304 are installed on the base plates 301, 302, and then the cylindrical main body 303 is mounted on the lower intermediate plate 303. 3
05 and fix them with bolts (not shown).
Next, a pipe 205 serving as a support member for the rubber elastic layer is added thereto.
Is inserted, the base plate 302 to which the intermediate plate 304 is fixed is placed on the cylindrical main body 305 in the same manner as the lower intermediate plate 303, and these are fixed by the fixing bar 306.

In order to form slits in these intermediate plates 303 and 304, the distal ends 303 a and 30 are located between the outer peripheral surface of the pipe and the inner surface of the cylindrical main body.
Cylindrical projection 303 having a semicircular cross section 4a
b, 304b are provided.

The rubber material forming the rubber elastic layer is injected from a rubber injection port (not shown). Thereafter, the mold is placed in an oven, heated and cured, and then cooled, and the base plate 301, 302 and the intermediate plates 303, 30 are removed from the main mold.
4 is removed, and the pipe 205 on which the rubber elastic layer is formed is taken out.

According to this manufacturing method, by providing the predetermined projections on the intermediate plate, the rubber elastic layer having the slits can be easily formed by an ordinary molding method.

FIGS. 5 and 6 show another example of the intermediate transfer drum, corresponding to FIGS. 2 and 3, respectively. The differences from the intermediate transfer drum shown in FIGS. 2 and 3 will be described.

In the intermediate transfer drum 110 shown in FIGS. 5 and 6, slits 2 formed on both end surfaces of the rubber elastic layer 203 are formed.
03a is formed at a position adjacent to the support member 204.

As shown in FIGS. 2 and 3, the slit 203a may be formed at an intermediate position of the rubber elastic layer 203. As shown in FIGS. May be formed at the boundary position with the boundary.

FIG. 7 is a block diagram showing another embodiment of the image recording apparatus of the present invention.

This image recording apparatus is a drum-shaped photosensitive member 10 having a photosensitive layer on its surface corresponding to four colors of black (K), yellow (Y), magenta (M), and cyan (C).
1K, 101Y, 101M, and 101C, and chargers 102K and 102 for uniformly charging these photosensitive members, respectively.
Y, 102M, and 102C; and image writing devices 104K, 104Y, 104M, and 104C that irradiate image light onto uniformly charged photoconductors to form electrostatic latent images, respectively.
Four developing devices 10 containing developers of respective colors of Y, M, and C
5K, 105Y, 105M, and 105C, a first intermediate transfer drum 110A that contacts two of the four photoconductors 101K, 101Y, 101M, and 101C, and another two photoconductors 101M. , 1
01C, another first intermediate transfer drum 11
0B and these two first intermediate transfer drums 110A, 110A,
110B, the second intermediate transfer drum 110 in contact with both
C, a transfer roller 106 for transferring the toner image superimposed and transferred on the second intermediate transfer drum 110C onto the recording material 111 conveyed by the conveying roller 109, and a toner image on the recording material 111. And a fixing device 107 for fixing the image.

Each photoconductor 101K, 101Y, 101M,
An electrostatic latent image corresponding to each color is formed on 101C,
Each of the developing devices 105K, 105Y, 105M, and 105C is developed with each color toner to form a toner image of each color. Each photoconductor 101K, 101Y, 101M, 101C
Each of the photoconductors 101K and 101Y among the upper color toner images
The upper toner image is superimposedly transferred onto one of the first intermediate transfer drums 110A, and the respective photoconductors 101M and 101C are transferred.
The upper toner image is transferred to the other first intermediate transfer drum 110.
B is over-transferred. The respective color toner images transferred to the two first intermediate transfer drums 110A and 110B are overlaid and transferred to the second intermediate transfer drum 110C, and the second
The toner image on the intermediate transfer drum 110C is further collectively transferred onto the recording material 111 as described above, and the fixing device 1
07, the recording material 111 is fixed on the recording material 111.

Two first intermediate transfer drums 1 shown in FIG.
10A, 110B, and second intermediate transfer drum 110
For C, an intermediate transfer drum having a structure in which a slit 203a shown in FIG. 2, FIG. 3, or FIG. 5, FIG. 6 is formed is employed.

[0066]

(Example 1) Length 248 mm, outer diameter 32 mm
The vicinity of both ends of the aluminum pipe blank is subjected to lathe processing, and a flange having a rotating shaft is press-fitted into this processed portion. In addition, the outer diameter tolerance is ± 0.01m by turning and polishing the surface of the aluminum tube, with reference to the rotation axis of the flange.
A support member, that is, a pipe finished with an outer diameter deflection accuracy of 0.01 mm or less was used.

The surface of the pipe was blasted and plied.
After applying the pattern, it has projections to form slits.
Volume resistivity of low temperature curing type
10 ^FiveInject and cure Ωcm conductive liquid silicone rubber
And molded. Take this out of the mold and at 200 ° C
Secondary curing was performed for 30 minutes. The thickness of this rubber elastic layer is 3m
m, hardness is 15 degrees in JIS-A hardness. The slit is
0.8mm wide, 10mm deep circle at the center of rubber elastic layer
It was formed in a cylindrical shape.

Next, after the primer was applied, a solution in which fluorinated rubber, a conductive material, a silane coupling agent and a curing agent were blended in a butyl acetate solvent was applied onto the silicone rubber by a spray gun, and this was applied for 10 minutes. Air dry,
Next, it was dried at a temperature of 60 ° C. for 10 minutes to form an intermediate layer having a thickness of 5 μm. The hardness of the used fluoro rubber is JIS-
A 65 °, volume resistivity 10 ¹⁰ Ωcm.

Next, the intermediate layer was spray-coated with latex obtained by adding carbon particles obtained by fluorinating a fluororubber, fluororesin-based fine particles, and a curing agent to the intermediate layer.
After pre-drying in an atmosphere of 50 ° C. for 30 minutes, the film was cured at 250 ° C. for 30 minutes to obtain an intermediate transfer drum having a surface layer having a thickness of 20 μm.

The hardness of the surface of the intermediate transfer drum is JIS-
A28 degrees. Further, the intermediate transfer drum was pressed against the metal plate with a load of 1 kg, a voltage of 100 V was applied to the metal plate and the metal support of the intermediate transfer drum, and the resistance was measured.
Its value was 10 ¹⁰ Ω. The maximum outer diameter of the roll end was larger than the minimum outer diameter of the center by 0.06 mm.

Example 2 The thickness of the rubber elastic layer was 8 mm,
An intermediate transfer drum was prepared in the same manner as in Example 1 except that the hardness was 15 degrees in JIS-A hardness, and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 2 mm and a depth of 20 mm.

The hardness of the intermediate transfer drum is JIS-A
17 degrees, and the resistance value was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.25 from the minimum outer diameter of the center.
mm.

Example 3 The thickness of the rubber elastic layer was 3 mm,
An intermediate transfer drum was manufactured in the same manner as in Example 1 except that the hardness was 35 degrees in JIS-A hardness and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 0.8 mm and a depth of 10 mm.

The hardness of the intermediate transfer drum is JIS-A
It was 37 degrees and its resistance was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.04 than the minimum outer diameter of the center.
mm.

Example 4 The thickness of the rubber elastic layer was 8 mm.
An intermediate transfer drum was prepared in the same manner as in Example 1 except that the hardness was 35 degrees in JIS-A hardness and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 2 mm and a depth of 20 mm.

The hardness of the intermediate transfer drum is JIS-A
It was 25 degrees and its resistance was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.18 from the minimum outer diameter of the center.
mm.

(Example 5) The thickness of the rubber elastic layer was 5 mm,
An intermediate transfer drum was prepared in the same manner as in Example 1 except that the hardness was 23 degrees in JIS-A hardness and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 2 mm and a depth of 20 mm.

The hardness of the intermediate transfer drum is JIS-A
It was 25 degrees and its resistance was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.12 from the minimum outer diameter of the center.
mm.

(Comparative Example 1) The same rubber elastic layer, intermediate layer, and
An intermediate transfer drum having a surface layer was prepared. This intermediate transfer drum has a JIS-A hardness of 25 degrees and a resistance value of 10 ¹⁰
Ω. At the end of the roll, the maximum outer diameter was 0.15 mm larger than the minimum outer diameter.

(Comparative Example 2) The thickness of the elastic layer was 2 mm, the hardness was 10 degrees in JIS-A hardness, and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 0.8 mm and a depth of 10 mm. An intermediate transfer drum having the same configuration as that of Example 1 except for the above was manufactured.

The hardness of the intermediate transfer drum is JIS-A
It was 25 degrees and its resistance was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.04 than the minimum outer diameter of the center.
mm.

(Comparative Example 3) The thickness of the rubber elastic layer was 9 mm,
An intermediate transfer drum was prepared in the same manner as in Example 1 except that the hardness was 10 degrees in JIS-A hardness and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 2 mm and a depth of 20 mm.

The hardness of the intermediate transfer drum is JIS-A
11 degrees, and the resistance value was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.28 from the minimum outer diameter of the center.
mm.

(Comparative Example 4) The thickness of the rubber elastic layer was 2 mm,
An intermediate transfer drum was prepared in the same manner as in Example 1 except that the hardness was 40 degrees in JIS-A hardness and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 0.8 mm and a depth of 10 mm.

The hardness of the intermediate transfer drum is JIS-A
45 degrees, and the resistance value was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.02 than the minimum outer diameter of the center.
mm.

(Comparative Example 5) The thickness of the elastic layer was 9 mm, the hardness was 40 degrees in JIS-A hardness, and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 2 mm and a depth of 20 mm. The same intermediate transfer drum as in Example 1 was manufactured.

The hardness of the intermediate transfer drum is JIS-A1
1 degree, and the resistance value was 10 ¹⁰ Ω. In addition, the maximum outer diameter of the roll end is 0.28 m from the minimum outer diameter of the center.
m was big.

(Comparative Example 6) Except that the thickness of the rubber elastic layer was 8 mm, the hardness was 15 degrees in JIS-A hardness, and the slit was formed in the center of the rubber elastic layer in a cylindrical shape having a width of 2 mm and a depth of 4 mm. Produced the same intermediate transfer drum as in Example 2.

The hardness of the intermediate transfer drum is JIS-A
17 degrees, and the resistance value was 10 ¹⁰ Ω. Also,
The maximum outer diameter of the roll end is 0.25 from the minimum outer diameter of the center.
mm.

The adhesion between the intermediate layer and the rubber elastic layer of the intermediate transfer drum shown in Examples and Comparative Examples was examined by the following procedure.

A seal tape having an area of 1 cm ² was attached to the center of the rubber elastic layer, and a primer was applied to the entire roll.
Then, peel off the sealing tape. Other procedures are described in Example 1.
Same as. A cut is made in the seal tape portion of the produced intermediate transfer drum with a cutter in parallel with the roll longitudinal direction. Since this portion has not been subjected to the primer treatment, the coating film in which the intermediate layer portion and the surface layer portion are integrated can be easily peeled from the rubber elastic layer. This portion is sandwiched by a tensile tester, and a tensile test is performed while the roll is rotatably fixed. The stress generated at this time was defined as the adhesion.

Further, in order to evaluate the set of the rubber elastic layer, the intermediate transfer drum and the photoreceptor are brought into close contact with each other with a pressure of 1 kgf, and they are allowed to stand at 50 ° C. and 85% environment for one week. The same method as in the evaluation of the transfer characteristics was performed, and it was observed whether or not the image was disturbed at the contact portion.

Further, the transfer characteristics (remaining toner amount, transfer unevenness, and image dropout) of the intermediate transfer drums shown in Examples and Comparative Examples were evaluated using spherical toner having an average particle diameter of 6 μm.

The photosensitive member and the intermediate transfer drum are brought into close contact with each other by pressing at 50 g / cm, and the toner image is primarily transferred from the photosensitive member to the intermediate transfer member at a transfer voltage of 400 V, and the transferred image on the intermediate transfer drum is secondarily transferred to paper. Transcribed. In the secondary transfer,
The transfer voltage between the intermediate transfer drum and the conductive backup roll placed behind the paper is 1000 V, and the drum peripheral speed is 10
0 mm / sec. The contact pressure between the conductive backup roll and the intermediate transfer body roll was set to 150 g / linear pressure using a spring mechanism at both ends of the conductive backup roll.
cm and the transfer characteristics were evaluated.

In the embodiment using the intermediate transfer drum according to the above-described embodiment, poor adhesion and settling did not occur, and the transfer characteristics were good.

However, in the intermediate transfer drum of Comparative Example 1, a uniform nip was not formed, and transfer unevenness occurred in the longitudinal direction of the roll. The intermediate transfer drums shown in Comparative Examples 2 and 3 had poor adhesion and settling, and were not practically usable.
Further, the transferability of the intermediate transfer drums of Comparative Examples 4 and 5 was good, but image omission occurred. Furthermore, in Comparative Example 6, transfer unevenness occurred in the longitudinal direction of the roll.

Table 1 shows the results of these evaluations. The residual toner amount and transfer unevenness were evaluated with a halftone image and a solid patch, and the holographic character was evaluated with a line image.

[0098]

[Table 1]

[0099]

As described above, in the image recording apparatus using the intermediate transfer member according to the present invention, a high quality image free from image quality defects can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of an image recording apparatus according to the present invention.

FIG. 2 is a schematic diagram of an intermediate transfer drum employed in the image recording apparatus shown in FIG.

FIG. 3 is a side view of an intermediate transfer drum employed in the image recording apparatus shown in FIG.

FIG. 4 is a view showing a structure of a mold for manufacturing an intermediate transfer drum.

FIG. 5 is a view corresponding to FIG. 2, showing another example of the intermediate transfer drum.

FIG. 6 is a diagram corresponding to FIG. 3, illustrating another example of the intermediate transfer drum.

FIG. 7 is a configuration diagram showing another embodiment of the image recording apparatus of the present invention.

FIG. 8 is a schematic diagram of a conventional intermediate transfer drum.

FIG. 9 is a schematic view of a roll having a crown shape.

FIG. 10 is a schematic view of a roll having a crown shaft.

FIG. 11 is a schematic view of a roll having a small diameter portion.

[Explanation of symbols]

101K, 101Y, 101M, 101C Photoconductor 102K, 102Y, 102M, 102C Charger 103 Cleaning Device 104a, 104K, 104Y, 104M, 104C
Writing device 105K, 105Y, 105M, 105C Developing device 106 Transfer roll 108 Static elimination lamp 109 Transport roll 110 Intermediate transfer drum 111 Recording material 201 Surface layer 202 Intermediate layer 203 Rubber elastic layer 204 Support member

Claims (6)

[Claims] An image carrier that carries a toner image on the surface by forming an electrostatic latent image on the surface and the electrostatic latent image is developed with toner; And at least one intermediate transfer member for receiving the transferred toner image and transferring the transferred toner image at a predetermined secondary transfer position, and finally transferring the toner image onto a predetermined recording medium. An image recording apparatus that forms an image on the recording medium by fixing the toner image onto the recording medium, wherein at least one of the one or more intermediate transfer bodies has a cylindrical shape. An image recording apparatus, comprising: a support; and an elastic layer formed on a cylindrical surface of the support, wherein slits orbiting the support are formed on both end surfaces of the elastic layer. . 2. The method according to claim 1, wherein the slits are formed at both end faces of the elastic layer.
2. The image recording apparatus according to claim 1, wherein the image recording apparatus is formed at a portion in contact with the support. 3. The method according to claim 2, wherein the slits are formed at both end faces of the elastic layer.
2. The image recording apparatus according to claim 1, wherein the image recording apparatus is formed at a position distant from the support. 4. The elastic layer has a thickness of 3 mm or more and 8 mm or more.
The image recording apparatus according to any one of claims 1 to 3, wherein the elastic layer is an elastic layer having a hardness of 15 to 35 degrees in JIS-A. 5. The image recording apparatus according to claim 1, wherein the slit has a length in a direction from each end face toward another end face of 5 mm or more and 30 mm or less. apparatus. 6. An intermediate transfer member for receiving a toner image at a predetermined primary transfer position while rotating and transferring the transferred toner image at a predetermined secondary transfer position next, comprising: a cylindrical support; And an elastic layer formed on a cylindrical surface of the support, wherein slits orbiting the support are formed on both end surfaces of the elastic layer.