Oki Data Corporation

Michiaki Ito

Takayuki Takazawa

Takashi Wakana

An image forming apparatus includes: a plurality of rollers including a first roller rotated by receiving rotation from a drive unit and a second roller rotated with the rotation of the first roller; a belt stretched around the plurality of rollers, the belt having an inner surface; and a tension applying unit that applies tension to the belt. The inner surface of the belt has an uneven shape. Each of at least one roller of the plurality of rollers satisfies conditions expressed by &#x3bc;kmax&#x2266;0.73 and &#x394;&#x3bc;k=(&#x3bc;kmax&#x2212;&#x3bc;kmin)&#x2266;0.51, where &#x3bc;kmax is a maximum dynamic friction coefficient between the inner surface of the belt and the roller, and &#x3bc;kmin is a minimum dynamic friction coefficient between the inner surface of the belt and the roller.

Image forming apparatus having rollers, belt and a tension applying unit

A belt unit includes rolls being rotatably supported and a belt to be conveyed by the rolls. In a dynamic viscoelasticity test with conditions of tensile load set in a frequency range of 0.01 to 100 [Hz], the belt unit satisfies 1&#x2266;G/G&#x2266;3.1, and L&#x2267;10 [MPa]. A storage elastic modulus of the belt at a temperature of 10[&#xb0; C.] is indicated by G. A storage elastic modulus of the belt at a temperature of 70[&#xb0; C.] is indicated by G. A loss elastic modulus of the belt at a temperature of 70[&#xb0; C.] is indicated by L.

Belt unit, transfer unit and image formation apparatus

An image forming device having a cleaning device that removes an adhered object on an endless belt body by contacting the endless belt body, which rotates while under tension. The endless belt body is formed with the following includes: an indentation Young's modulus is equal to or more than 5.5 GPa and is equal to or less than 10.0 GPa, and a specularity of a contacting surface that contacts the cleaning device is equal to or more than 50 and is equal to or less than 100.

Image forming device

A belt drive apparatus includes: a rotatable first roller; a rotatable second roller; a belt member stretched by the first and the second rollers so as to be capable of being conveyed by the first roller and the second roller; and a restraint member provided on at least one of the two ends of the second roller and including a belt receiving surface to be brought into contact with an edge portion of the belt member. The belt receiving surface and an axis of the second roller make an angle that is not smaller than 93&#xb0; but not larger than 115&#xb0;.

Belt drive apparatus and image forming apparatus

A belt unit includes an endless belt that transports a recording medium thereon. The endless belt has a Young's modulus in the range of 3.5&#x2266;Y&#x2266;7.0. The endless belt is disposed about a plurality of rollers, and runs about the rollers. The endless belt has a thickness such that 0.0025&#x2266;Y&#xd7;T&#x2266;0.007 where Y is the Young's modulus and T is the thickness. A cleaning member removes deposits from the surface of the endless belt. The belt unit may also operate as a transfer unit and include a cleaning member disposed about a plurality of rollers. The cleaning member removes deposits from the surface of the endless belt. An image forming apparatus may include the belt unit or transfer unit.

Belt unit, transfer unit and image forming apparatus

A belt is entrained about the rollers. A belt guide is secured to an inner surface of the belt and is guided by pulleys. The belt guide is formed of a material that has a dissipation factor of tan &#x3b4;&#x2267;0.05 at a resonance frequency of 1 Hz&#xb1;10% and at a temperature of 50&#xb1;0.5&#xb0; C., and a storage modulus of E'&#x2267;8.0&#xd7;10(Pa) at a resonance frequency of 1 Hz&#xb1;10% and at a temperature of 50&#xb1;0.5&#xb0; C. Another material has tan &#x3b4;&#x2267;0.05 at 1 Hz&#xb1;10% and at 50&#xb1;0.5&#xb0; C., and E&#x2032;&#x2267;8.0&#xd7;10(Pa) at 1 Hz&#xb1;10% and at 50&#xb1;0.5&#xb0; C. The belt guide may be formed of a plurality of layers.

Belt driving apparatus and image forming apparatus that uses the belt driving apparatus

An image forming apparatus includes a first roller; a second roller; a belt tensely provided between the first roller and the second roller; and a guiding member for guiding an edge of the belt. Further, the belt has an edge surface having a step portion of equal to or smaller than 0.05 mm and a ten-point mean roughness (Rz) of equal to or smaller than 5.0 &#x3bc;m.

Image forming apparatus

An endless belt includes base resin, polyaniline, and alkyl imide acid. Alternatively, the endless belt includes base resin, polyaniline, and alkylsulfonic acid. With such an arrangement, it becomes possible to keep constant the electric resistance of the endless belt despite the change in circumstances or the change with the passage of time, and to thereby enhance the printing quality.

Endless belt, belt device and image forming apparatus

A belt is entrained on a plurality of rollers and runs when the rollers are driven to rotate. A bead is attached to the belt and prevents the belt-like member from running crooked. The bead includes a first layer formed of a first material having a first hardness and a second layer formed of a second material having a second hardness. The second layer is laminated on the first layer. The bead is attached to the belt with the first layer being closer to the belt than the second layer. The first material and the second material expand simultaneously with temperature and humidity, and the first material and the second material contract simultaneously with temperature and humidity. The first hardness is higher than the second hardness.

Endless belt having deformation prevention qualities, and image forming apparatus that uses the endless belt

A belt unit includes an endless belt and a cleaning member. The endless belt has a value of ten-point height of roughness Rz not larger than 0.2 &#x3bc;m, a value of shininess not less than 100, a creep not larger than 0.03%. The cleaning member is in contact with said endless belt and removes foreign matter adhering to said endless belt. The belt unit may be applied to an image forming apparatus either of direct transfer type and intermediate transfer type.

Belt unit and image forming apparatus that incorporates the belt unit

An endless belt transports a recording medium through image forming sections and transfers toner images from corresponding ones of the image forming sections onto the recording medium. The endless belt has a surface resistivity and a volume resistivity. The surface resistivity and the volume resistivity are related such that 0.3&#x2266;(log &#x3c1; s&#x2212;log &#x3c1; v)&#x2266;1.3 where &#x3c1; s is the surface resistivity in &#x3a9;/&#x25a1; measured after a voltage of substantially 500 V is applied to the endless belt for ten seconds and &#x3c1; v is the volume resistivity in &#x3a9;&#xb7;cm ten after a voltage of substantially 250 V is applied to the endless belt for ten seconds.

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Tokyo, Japan

Michiaki Ito