Fixing device and fixing temperature control method of fixing device

• US 10,379,466 B2
• Filed: 01/11/2018
• Issued: 08/13/2019
• Est. Priority Date: 05/19/2014
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Tec Corporation (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Takagi, Osamu
• Primary Examiner(s): Bonnette, Rodney A
• Application Number:
  US15/867,800
• Publication Number:
  US 20180136594A1
• Time in Patent Office: 579 Days
• CPC Class Codes: G03G 15/2039 with means for controlling the fixing temperature
• CPC Class Codes: G03G 15/2042 specially for the axial heat partition
• CPC Class Codes: G03G 15/2046 specially for the influence of heat loss, e.g. due to the contact with the copy material or other roller
• CPC Class Codes: G03G 15/2053 Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating
• CPC Class Codes: G03G 2215/2022 the fixing nip having both a stationary and a rotating belt support member opposing a pressure member

Abstract

According to one embodiment, a fixing device includes determination means for determining the size of an image forming area of a medium, heating means for including an endless rotating body, plural heat-generating members which are formed in a perpendicular direction to a transporting direction, inclined by a predetermined angle, and divided by a predetermined length, and are disposed so as to come into contact with an inner side of the rotating body, and a switching unit which switches individual conduction, and heats the medium, pressing means for forming a nip by performing pressing and contact at a position of the plural heat-generating members, and nipping and carrying the medium in the transporting direction along with the heating means, and heating control means for controlling the switching unit to select and conduct heat-generating members and controlling the heating means to heat the medium.

Claims

1. A fixing device comprising:

an endless rotating body;

a plurality of heat-generating resistors that heats a medium, each heat-generating resistor being inclined from the transporting direction to a direction of a predetermined angle, and divided by a predetermined length, and being disposed so as to come into contact with an inner side of the endless rotating body;

a plurality of switches, each of the switch being connected to each heat-generating resistor, that switch individual conduction of these switches connected to heat-generating resistors, the plurality of heat-generating resistors being able to be selected to be connected corresponding to a posit ion through which the medium passes; and

a pressing roller that forms a nip with the plurality of heat-generating resistors, and configured to nip the medium therebetween and carry the medium in the transporting direction.

2. The device according to claim 1, wherein

the plurality of heat-generating resistors are formed to have the same size, and bottom portions of the plurality of heat-generating resistors are arranged on the same line.

3. The device according to claim 2, wherein

the plurality of heat-generating resistors are formed to have resistance values which are changed at a certain ratio.

4. The device according to claim 1, wherein

the plurality of heat-generating resistors are formed to have resistance values which are changed at a certain ratio.

5. A printing device comprising:

an endless belt;

a plurality of heat-generating resistors that heat a medium, each heat-generating resistor being inclined from the transporting direction to a direction of a predetermined angle, and divided by a predetermined length, and being disposed so as to come into contact with an inner side of the endless belt;

a plurality of switches, each of the switches being connected to each heat-generating resistor, that switch individual conduction of these switches connected to heat-generating resistors;

a pressing roller that forms a nip with the plurality of heat-generating resistors, and configured to nip the medium therebetween and carry the medium in the transporting direction; and

a controller that determines the size of a medium on which a toner image is formed, the controller that select the plurality of switches connected to the plurality of heat-generating resistors to be conducted.

6. The printing device according to claim 5, wherein

the controller determines the size of the medium and a thickness or basis weight of the medium, and

the controller controls the plurality of switches to select heat-generating resistors to be conducted, among the heat-generating resistors corresponding to the position through which the medium passes based on a result of the determination.

7. The printing device according to claim 5, wherein

the plurality of heat-generation resistors are formed to have the same size, and bottom portions of the plurality of heat-generating resistors are arranged on the same line.

8. The printing device according to claim 7, wherein

the plurality of heat-generation resistors are formed to have resistance values which are changed at a certain ratio.

9. The printing device according to claim 5, wherein

the controller determines the size of the medium and a surface temperature of the heat-generating resistor, and

the controller controls the plurality of switches to select heat-generating resistors to be conducted, among the heat-generating resistors corresponding to the position through which the medium passes based on a result of the determination.

10. The printing device according to claim 9, wherein

the plurality of heat-generating resistors are formed to have the same size, and bottom portions of the plurality of heat-generating resistors are arranged on the same line.

11. The printing device according to claim 10, wherein

the plurality of heat-generating resistors are formed to have resistance values which are changed at a certain ratio.

12. The printing device according to claim 5, wherein

the controller determines the size of the medium and a value of the outdoor air temperature, and

the controller controls the plurality of switches to select heat-generating resistors to be conducted, among the heat-generating resistors corresponding to the position through which the medium passes based on a result of the determination.

13. The printing device according to claim 12, wherein

the plurality of heat-generating resistors are formed to have the same size, and bottom portions of the plurality of heat-generating resistors are arranged on the same line.

14. The printing device according to claim 13, wherein

the plurality of heat-generating resistors are formed to have resistance values which are changed at a certain ratio.

15. A fixing temperature control method of a fixing device which includes a plurality of heat-generating resistors, a plurality of switches, and a pressing roller and fixes a toner image on the medium by heating a plurality of heat-generating resistors that heat a medium, each heat-generating resistor being inclined from the transporting direction to a direction of a predetermined angle, and being divided by a predetermined length, individually switching conduction of these heat-generating resistors, the plurality of switch, each of the switches being connected to each heat-generation resistor, the method comprising:

determining the size of the medium; and

controlling the plurality of switch to select and conduct these switches connected to heat-generating resistors corresponding to a position through which the medium passes, among the plurality of heat-generating resistors and controlling heating of the heat-generating resistors.

16. The fixing temperature control method according to claim 15 further comprising:

determining the size of the medium and a thickness or basis weight of the medium, and

controlling the plurality of switches to select heat-generating resistors to be conducted, among the heat-generating resistors corresponding to the position through which the medium passes based on a result of the determination.

17. The fixing temperature control method according to claim 15 further comprising:

determining the size of the medium and a surface temperature of the heat-generating resistor, and

controlling the plurality of switches to select heat-generating resistors to be conducted, among the heat-generating resistors corresponding to the position through which the medium passes based on a result of the determination.

18. The fixing temperature control method according to claim 15 further comprising:

the controller determines the size of the medium and a value of the outdoor air temperature, and

the controller controls the plurality of switches to select heat-generating resistors to be conducted, among the heat-generating resistors corresponding to the position through which medium passes based on a result of the determination.