JP3416693B2 - Recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus to which an electrophotographic method is applied, and more particularly to improvement of a recording apparatus having an intermediate transfer member.

In recent years, as a recording apparatus such as a color electrophotographic apparatus, a recording apparatus has been developed in which a toner image is once transferred from a photosensitive member to an intermediate transfer member and then further transferred to a recording sheet or the like. In a recording apparatus having this kind of intermediate transfer member, the material of the intermediate transfer member directly affects the recorded image, so optimization of the configuration of the intermediate transfer member is sought.

[0003]

2. Description of the Related Art Conventionally, as an intermediate transfer member, there is known an intermediate transfer drum having a structure in which a resistor belt made of polycarbonate or the like having a predetermined transfer characteristic is provided in a surface layer portion and a flexible layer such as rubber is provided in a lower layer portion. Has been.

[0004]

The material of the lower layer portion of the above-mentioned intermediate transfer drum is required not only to have flexibility but also to have a small volume resistance value from the viewpoint of process so as to reduce bias loss. However, a material having a small volume resistance value is generally hard, and when the lower layer portion is formed from such a hard material, the contact between the intermediate transfer drum and the photosensitive member or the secondary transfer roller becomes uneven, and a good image is obtained. There was something I couldn't do.

Therefore, an object of the present invention is to provide a recording apparatus which can obtain good recorded image quality with little bias loss.

[0006]

According to the present invention, in a recording apparatus for transferring a toner image formed on a photoconductor to an intermediate transfer body, and further transferring the toner image on the intermediate transfer body to a recording medium, The intermediate transfer member is composed of a drum having a surface layer portion made of an elastic body, and a resistor belt stretched around the outer periphery of the drum. The resistor belt has a volume resistance value of 1 or less.
Provided is a recording device comprising an outer layer having a thickness of 0 ⁸ to 10 ¹² Ωcm and an inner layer having a volume resistance value of 10 ⁵ Ωcm or less inside the outer layer.

In the recording apparatus of the present invention, since the resistor belt of the intermediate transfer member is composed of the outer layer having a large volume resistance value and the inner layer having a small volume resistance value, transfer to the intermediate transfer member through the inner layer. Bias loss decreases when a bias is applied. Further, in this intermediate transfer member, since the drum having the surface layer portion made of the elastic body is provided on the inner circumference of the resistor belt, the contact between the intermediate transfer member and the photosensitive member and the secondary transfer roller is uneven. It becomes difficult to obtain a good recorded image quality. Further, according to the present invention, in a recording apparatus for transferring a toner image formed on a photoconductor to an intermediate transfer body and further transferring the toner image on the intermediate transfer body to a recording medium, the intermediate transfer body is made of elastic material. It comprises a drum having a surface layer portion composed of a body and a conductive drum positioned inside the surface layer portion, and a resistor belt stretched around the outer periphery of the drum. The resistor belt has a volume resistance value of 10 ⁸ 10 ¹² and an outer layer of [Omega] cm, the volume resistivity on the inside of the outer layer is made from the following of the inner layer 10 ⁵ [Omega] cm, a transfer bias is applied to the resistor belt through the conductive drum, the said drum A notch is formed to reach the conductive drum, a conductive member is seated on the bottom of the notch, and the resistor belt is fixed in the notch so that the inner layer of the resistor belt contacts the conductive member. Characterized by That the recording apparatus is provided. Furthermore, according to the present invention, in a recording device for transferring a toner image formed on a photoconductor to an intermediate transfer member and further transferring the toner image on the intermediate transfer member to a recording medium, the intermediate transfer member is:
A drum having an elastic surface layer portion and a conductive drum positioned inside the surface layer portion, and a resistor belt stretched around the outer periphery of the drum, the resistor belt having a volume resistance value of 10 An outer layer having a thickness of ⁸ to 10 ¹² Ωcm and an inner layer having a volume resistance value of 10 ⁵ Ωcm or less inside the outer layer,
A transfer bias is applied to the resistor belt via the conductive drum, a notch reaching the conductive drum is formed in the drum, and a pressing member is fitted into the notch via the resistor belt. A recording device is provided.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram of a color recording apparatus to which the present invention is applied, and FIG. 2 is a diagram showing a printing sequence of the apparatus of FIG. The configuration and operation of this device will be described with reference to FIGS.

When a recording command is issued from a control unit (not shown), the feeding operation of the recording paper 5 is started. Recording paper 5 taken out from paper cassette 1 by delivery roller 2
Is temporarily stopped at the nip portion of the registration roller 3 which is stopped, and the timing with the recording process is taken.

After that, the recording paper 5 is sent to the transfer roller 30 by the registration roller 3 which has restarted to rotate, and the color toner image superposed on the intermediate transfer drum 20 is transferred to the recording paper 5. The recording paper 5 is further sent to the fixing device 40, and the toner image is fixed on the recording paper 5 by heat and pressure applied from the fixing roller 41 and the pressure roller 42.

A charger 16 is provided around the photosensitive drum 10.
And an exposure system 50 and developing units 11, 12, 13 and 14
The intermediate transfer drum 20 and the cleaner blade 15 are provided in this order in the rotation direction of the photosensitive drum 10.

The developing units 11, 12, 13, and 14 form yellow (Y), magenta (M), cyan (C), and black (K) color toner images on the photosensitive drum 10, respectively. YM is set on the photosensitive drum 10 for each rotation of the photosensitive drum.
Toner images are sequentially formed in the order of CK.

The formed toner image is transferred to the intermediate transfer drum 2
By the bias applied to 0, they are sequentially transferred from the photosensitive drum 10 onto the intermediate transfer drum 20 (primary transfer).

The cleaner blade 25 and the transfer roller 30 are separated from the intermediate transfer drum 20 during the four-color superposition. When the transfer of the four colors of YMCK is completed, the transfer roller 40 is pressed against the intermediate transfer drum 20, and the color toner images are collectively transferred to the recording paper 5 (secondary transfer).

When the transfer of the toner image onto the recording paper 5 is completed, the transfer roller 30 is separated from the intermediate transfer drum 20. Further, the cleaner blade 25 is used for the intermediate transfer drum 20.
Then, the intermediate transfer drum 20 after the transfer is cleaned by pressure. Then, the cleaner blade 25 is separated from the intermediate transfer drum 20. Color recording is performed one after another by repeating the above operation.

FIG. 3 is a sectional view of the intermediate transfer drum 20 of FIG. The intermediate transfer drum 20 is configured by providing a resistor belt 65 around the drum 75. The drum 75 includes a surface layer portion (rubber portion) 72 made of an elastic body and a conductive drum (core metal portion) 71 located inside the surface layer portion 72.
The material of the surface layer portion 72 is urethane rubber having a rubber hardness of 40 degrees with an emphasis on flexibility. The conductive drum 71 is made of metal in this embodiment.

Prior to explaining the structure for fixing the resistor belt 65 to the drum 75, the resistor belt 65 will be described with reference to FIG.
The configuration of will be described. The resistor belt 65 has a volume resistance of 10
Constituted the volume resistivity 10 ³ [Omega] cm of the conductive polymer 62 on the inner surface of the ¹⁰ [Omega] cm polycarbonate of the endless belt 61 covers.

The volume resistance of the endless belt 61 is 10 ⁸
If it is -10 ¹² Ωcm, sufficient transfer characteristics can be obtained.
It has been found that when the volume resistance of the conductive polymer 62 is 10 ⁵ Ωcm or less, no bias loss occurs.

As shown in FIG. 3, the resistor belt 65 is provided so as to be in close contact with the surface of the surface layer portion 72 of the drum 75. A notch 76 reaching the conductive drum 71 is formed in the drum 75 in the drum axial direction, and the conductive member 7 made of metal or the like is provided at the bottom of the notch 76.
4 is seated.

The resistor belt 65 has an inner layer 62 (see FIG. 5).
(Refer to FIG. 7) so as to contact the conductive member 74.
It is fixed in the notch 76 by 3. Resistor belt 6
5 so as to adhere well to the surface layer portion 72 of the drum 75,
In this example, as shown in FIG.
3 is biased toward the shaft 83 by springs 80 and 81. The shaft 83 is provided so as to rotate integrally with the conductive drum 71.

The shaft 83 is electrically connected to the conductive drum 71, and the shaft 83 has a brush 84.
A transfer bias power source is connected via the switch 85 and the switch 85. As a result, the transfer bias from the transfer bias power source 86 can be selectively applied to the conductive drum 71 by the switch 85.

When a transfer bias is applied to the conductive drum 71, the bias is directly applied to the resistor belt 65. Here, since the volume resistance of the inner layer 62 of the resistor belt 65 is sufficiently small, there is no bias loss, and a transfer bias almost equal to the applied bias appears on the intermediate transfer drum, which enables good transfer.

FIG. 6 is a partial sectional view showing another structural example of the intermediate transfer drum. In the example shown in (A), in order to prevent connection failure between the inner layer 62 of the resistor belt 65 and the conductive drum 71, a conductive member 74 ′ having elasticity is seated on the bottom of the notch 76. .

Further, in the example shown in (B), the pressing member 73 is fitted into the notch 76 so that the width of the pressing member 73 substantially coincides with the width of the notch 76, so that the resistor belt is fitted. The inner layer 62 of 65 contacts the conductive drum 71 at the side of the notch 76. According to this structure, the conductive member 7 in the above-described embodiments is used.
4,74 'becomes unnecessary.

In each of the embodiments, the drum 7
The surface layer 72 of No. 5 has a relatively high volume resistance,
Since the volume resistance of the surface layer portion 72 is unrelated to the transfer potential application system, it does not affect the transfer performance.

Since the surface layer portion 72 of the drum 75 has sufficient flexibility, the intermediate transfer drum 20 and the photosensitive drum 10 are
Also, there is no risk of uneven contact with the transfer roller 30.

[0027]

As described above, according to the present invention,
There is an effect that it is possible to provide a recording apparatus that can obtain good recorded image quality with little bias loss.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a color recording apparatus to which the present invention is applied.

FIG. 2 is a diagram showing a printing sequence of the apparatus of FIG.

FIG. 3 is a sectional view of the intermediate transfer drum shown in FIG.

FIG. 4 is a front view of the intermediate transfer drum of FIG.

5 is a cross-sectional view of the resistor belt shown in FIG.

FIG. 6 is a partial cross-sectional view showing another example of the intermediate transfer drum.

[Explanation of symbols]

20 Intermediate transfer drum 75 drums 71 Conductive drum 72 Surface layer 65 resistor belt

Claims (3)

(57) [Claims] 1. A recording apparatus for transferring a toner image formed on a photoconductor to an intermediate transfer body and further transferring the toner image on the intermediate transfer body to a recording medium, wherein the intermediate transfer body is made of an elastic body. And a resistor belt stretched around the outer circumference of the drum, and the resistor belt has a volume resistance value of 10 ⁸ to 10 ^8. It is composed of an outer layer of ¹² Ωcm and an inner layer having a volume resistance value of 10 ⁵ Ωcm or less inside the outer layer. A transfer bias is applied to the resistor belt through the conductive drum, and the conductive layer is applied to the drum. A notch reaching the elastic drum, a conductive member is seated on the bottom of the notch, and the resistor belt is fixed in the notch so that its inner layer contacts the conductive member. Characterized by Recording device. 2. The conductive member has elasticity.
The recording device according to 1. 3. A recording apparatus for transferring a toner image formed on a photoconductor to an intermediate transfer member and further transferring the toner image on the intermediate transfer member to a recording medium, wherein the intermediate transfer member is made of an elastic material. And a resistor belt stretched around the outer circumference of the drum, and the resistor belt has a volume resistance value of 10 ⁸ to 10 ^8. It is composed of an outer layer of ¹² Ωcm and an inner layer having a volume resistance value of 10 ⁵ Ωcm or less inside the outer layer. A transfer bias is applied to the resistor belt through the conductive drum, and the conductive layer is applied to the drum. A recording apparatus, wherein a notch reaching the sex drum is formed, and a pressing member is fitted in the notch via the resistor belt.