Image forming apparatus, roller, belt, and fixing unit of image forming apparatus
View Patent ↗A tubular roller to support a belt having an inner surface provided with a protruding circumferential edge having a width includes a first portion, a second portion, and a third portion. The first portion has a first outer radius and contacts the inner surface of the belt. The second portion has a second outer radius smaller than the first outer radius of the first portion. The third portion is connected to the first portion with a first vertically extending wall and to the second portion with a second vertically extending wall and has a third outer radius smaller than the second outer radius.
1. A tubular roller configured to support a belt, the belt comprising an inner surface in contact with a surface of the roller, the inner surface including a protruding circumferential edge, the roller comprising:
an engagement portion configured to engage with the protruding circumferential edge of the belt,
wherein the roller has a first thickness and a second thickness, the second thickness being greater than the first thickness, and
wherein a portion of the roller having the second thickness includes the engagement portion.
2. A tubular roller configured to support a belt having an inner surface provided with a protruding circumferential edge having a width in an axial direction of the roller, the tubular roller comprising:
a first portion having a first outer radius, the first portion being configured to contact the inner surface of the belt; and
a second portion having a second outer radius smaller than the first outer radius of the first portion; and
a third portion connected to the first portion with a first vertically extending wall and to the second portion with a second vertically extending wall, the third portion having a third outer radius smaller than the second outer radius.
3. The tubular roller according to claim 2 , wherein the first vertically extending wall has a vertical height equal to a difference between the first outer radius and the third outer radius and the second vertically extending wall has a vertical height equal to a difference between the second outer radius and the third outer radius.
4. The tubular roller according to claim 2 , wherein the third portion has a width that is greater than the width of the circumferential edge.
5. A fixing unit configured to fix a toner image on a recording medium in an image forming apparatus, comprising:
a fixing belt comprising an inner surface including a protruding circumferential edge;
a first roller configured to support and heat the fixing belt, the first roller comprising:
an engagement portion configured to engage with the protruding circumferential edge of the fixing belt; and
a heater provided in an inner space of the first roller,
wherein the roller has a first thickness and a second thickness, the second thickness being greater than the first thickness, and
wherein a portion of the roller having the second thickness includes the engagement portion;
a second roller configured to support the fixing belt with the first roller and to fix the toner image on the recording medium; and
a third roller configured to press the fixing belt toward the second roller.
6. A fixing unit configured to fix a toner image on a recording medium in an image forming apparatus, comprising:
a fixing belt including an inner surface provided with a protruding circumferential edge having a width;
a first roller configured to support and heat the fixing belt, the first roller comprising:
a first portion having a first outer radius, the first portion being configured to contact the inner surface of the fixing belt; and
a second portion having a second outer radius smaller than the first outer radius of the first portion;
a third portion connected to the first portion with a first vertically extending wall and to the second portion with a second vertically extending wall, the third portion having a third outer radius smaller than the second outer radius; and
a heater provided in an inner space of the first roller;
a second roller configured to support the fixing belt with the first roller and to fix the toner image on the recording medium; and
a third roller configured to press the fixing belt toward the second roller.
7. The fixing unit according to claim 6 , wherein the first vertically extending wall has a vertical height equal to a difference between the first outer radius and the third outer radius and the second vertically extending wall has a vertical height equal to a difference between the second outer radius and the third outer radius.
8. The fixing unit according to claim 6 , wherein the third portion has a width that is greater than the width of the circumferential edge.
9. The fixing unit according to claim 6 , wherein the second roller and the third roller define a nip, through which the recording medium is passed to fix the toner image on the recording medium.
10. The fixing unit according to claim 6 , further comprising a fourth roller configured to exert a tension to the fixing belt supported by the first roller and the second roller.
11. The fixing unit according to claim 6 , wherein the first roller is formed of a tubular metal having a thickness of 0.8 mm or less.
12. The fixing unit according to claim 11 , wherein the metal comprises aluminum.
13. An image forming apparatus, comprising:
an image carrier configured to carry a toner image thereon;
a recording medium configured to receive the toner image directly or indirectly from the image carrier; and
a fixing unit configured to fix the toner image on the recording medium, comprising:
a fixing belt comprising an inner surface including a protruding circumferential edge;
a first roller configured to support and heat the fixing belt, the first roller comprising:
an engagement portion configured to engage with the protruding circumferential edge of the fixing belt; and
a heater provided in an inner space of the first roller,
wherein the roller has a first thickness and a second thickness, the second thickness being greater than the first thickness, and
wherein a portion of the roller having the second thickness includes the engagement portion;
a second roller configured to support the fixing belt with the first roller and to fix the toner image on the recording medium; and
a third roller configured to press the fixing belt toward the second roller.
14. An image forming apparatus, comprising:
an image carrier configured to carry a toner image thereon;
a recording medium configured to receive the toner image from the image directly or indirectly carrier;
a fixing unit configured to fix the toner image on the recording medium, comprising:
a fixing belt including an inner surface provided with a protruding circumferential edge having a width;
a first roller configured to support and heat the fixing belt, the first roller comprising:
a first portion having a first outer radius, the first portion being configured to contact the inner surface of the fixing belt; and
a second portion having a second outer radius smaller than the first outer radius of the first portion;
a third portion connected to the first portion with a first vertically extending wall and to the second portion with a second vertically extending wall, the third portion having a third outer radius smaller than the second outer radius; and
a heater provided in an inner space of the first roller;
a second roller configured to support the fixing belt with the first roller and to fix the toner image on the recording medium; and
a third roller configured to press the fixing belt toward the second roller.
15. The image forming apparatus according to claim 14 , wherein the first vertically extending wall has a vertical height equal to a difference between the first outer radius and the third outer radius and the second vertically extending wall has a vertical height equal to a difference between the second outer radius and the third outer radius.
16. The image forming apparatus according to claim 14 , wherein the third portion has a width that is greater than the width of the circumferential edge.
17. The image forming apparatus according to claim 14 , wherein the second roller and the third roller define a nip, through which the recording medium is passed to fix the toner image on the recording medium.
18. The image forming apparatus according to claim 14 , further comprising a fourth roller configured to exert a tension to the fixing belt supported by the first roller and the second roller.
19. The image forming apparatus according to claim 18 , wherein the metal comprises aluminum.
20. The image forming apparatus according to claim 14 , wherein the first roller is formed of a tubular metal having a thickness of 0.8 mm or less.
21. Am image forming apparatus, comprising:
an image carrier configured to carry a toner image thereon;
an intermediate transfer belt configured to receive the toner image from the image carrier, the intermediate transfer belt comprising an inner surface including a protruding circumferential edge having a width and being supported by a tubular roller comprising:
an engagement portion configured to engage with the protruding circumferential edge of the intermediate transfer belt,
wherein the roller has a first thickness and a second thickness, the second thickness being greater than the first thickness, and
wherein a portion of the roller having the second thickness includes the engagement portion;
a recording medium configured to receive the toner image directly or indirectly form the image carrier; and
a fixing unit configured to fix the toner image on the recording medium.
22. An image forming apparatus, comprising:
an image carrier configured to carry a toner image thereon;
a recording medium configured to receive the toner image directly or indirectly from the image carrier;
a transport belt for transporting the recording medium, the transport belt comprising an inner surface including a protruding circumferential edge having a width and being supported by a tubular roller comprising:
an engagement portion configured to engage with the protruding circumferential edge of the transport belt; and
wherein the roller has a first thickness and a second thickness, the second thickness being greater than the first thickness, and
wherein a portion of the roller having the second thickness includes the engagement portion;
a fixing unit configured to fix the toner image on the recording medium.