Fixing unit and image forming apparatus
View Patent ↗A fixing unit for an image forming apparatus includes a heating element 102 , a temperature sensor 119 to detect the temperature of the hating element, and an arm to hold the temperature sensor 119 , and positioning means 108 and 110 to adjust the position of the arm 105 with respect to the heating element.
1. A fixing unit for an image forming apparatus, comprising:
a heating element;
a temperature sensor to detect a temperature of said heating element;
an arm to hold said temperature sensor;
a frame to support the heating element;
an elastic member to support the arm; and
a positioning member for adjusting a position of said arm with respect to said heating element such that the temperature sensor is away from the heating element with a space therebetween, said positioning member including a connecting member for connecting the arm and the elastic member to adjust the position of the arm with respect to the heating element in a state that the arm and the elastic member are attached to the frame, said connecting member being arranged to be adjustable for a position thereof with respect to the frame so that a deformation amount of the elastic member changes according to the position of the connecting member, said arm being arranged to be movable with respect to the heating element according to the deformation amount of the elastic member.
2. The fixing unit according to claim 1 , wherein said position of said arm is adjusted by said positioning member such that said temperature sensor does not contact said heating element.
3. The fixing unit according to claim 1 , wherein said frame supports both edge portions of said elastic member.
4. The fixing unit according to claim 1 , wherein said elastic member has an opening between a portion thereof supported on said frame and a portion thereof supporting said arm.
5. The fixing unit according to claim 1 , wherein said connecting member has a screw penetrating through a center portion of said elastic member, a base portion of said arm, and said frame, and a nut fitted to said screw.
6. The fixing unit according to claim 1 , further comprising a spacer having a specified thickness, wherein said connecting member connects a center portion of said elastic member and a base portion of said arm with said frame via said spacer against an elastic force of said elastic member when the position of said arm is adjusted.
7. The fixing unit according to claim 6 , wherein said spacer is arranged to be movable between a first position and a second position, and is disposed at said first position when said position of said arm is adjusted, and said positioning member is moved toward said heating element for a specified distance corresponding to the specified thickness of said spacer.
8. The fixing unit according to claim 7 , wherein said spacer is disposed at said second position, and said positioning member moves said arm by a specified distance away from said heating element.
9. An image forming apparatus having the fixing unit according to claim 1 to fix a developing agent onto a medium by heating said developing agent.
10. The fixing unit according to claim 1 , wherein said elastic member is formed of an elongated plate extending in a first direction parallel to a longitudinal direction of the heating element, said arm extending in a second direction perpendicular to the first direction.
11. The fixing unit according to claim 1 , wherein said frame is arranged away from the arm with the elastic member therebetween so that the frame is stationary with respect to the heating element when the positioning member adjusts the position of the arm with respect to the heating element.
12. The fixing unit according to claim 1 , wherein said frame is formed of an elongated plate extending in a first direction parallel to a longitudinal direction of the heating element, said arm extending in a second direction perpendicular to the first direction.
13. A fixing unit for an image forming apparatus, comprising:
a heating element;
a temperature sensor to detect a temperature of said heating element;
an arm to hold said temperature sensor;
a frame to support the heating element;
an elastic member to support the arm;
a spacer having a specified thickness; and
a positioning member for adjusting a position of said arm with respect to said heating element such that the temperature sensor is away from the heating element with a space therebetween, said positioning member including a connecting member for connecting the arm and the elastic member to adjust the position of the arm with respect to the heating element in a state that the arm and the elastic member are attached to the frame,
wherein said elastic member has a flat shape, said elastic member is supported by said frame at two positions which are equally distant from a portion of said elastic member to support said arm, and said connecting member connects a center portion of said elastic member and a base portion of said arm with said frame via said spacer against an elastic force of said elastic member when the position of said arm is adjusted.
14. A fixing unit for an image forming apparatus, comprising:
a heating element;
a temperature sensor to detect a temperature of said heating element;
an arm to hold said temperature sensor;
a frame to support the heating element;
an elastic member to support the arm;
a spacer having a specified thickness; and
a positioning member for adjusting a position of said arm with respect to said heating element such that the temperature sensor is away from the heating element with a space therebetween, said positioning member including a connecting member for connecting the arm and the elastic member to adjust the position of the arm with respect to the heating element in a state that the arm and the elastic member are attached to the frame,
wherein said connecting member has a screw penetrating through a center portion of said elastic member, a base portion of said arm, and said frame, and a nut fitted to said screw, and said elastic member has a restricting member to restrict movement of said arm in a direction perpendicular to longitudinal directions of said screw and said arm.
15. The fixing unit according to claim 14 , wherein said arm has at its end a protrusion extending in the longitudinal direction of said arm, and said frame has a restricting member to restrict movement of said arm in the longitudinal direction of said screw.
16. The fixing unit according to claim 15 , wherein said arm has a protrusion having a surface that extends in the longitudinal direction of said screw near said temperature sensor, an upper edge of said surface is specified distance away from said temperature sensor, and said upper edge is arranged so as to be accessible for measurement through a hole of said restricting member.