Heating device, fixing device, and image forming apparatus

1. A heating device comprising:

a surface heater unit including a heater portion that generates heat in a region extending in a longitudinal direction, the surface heater unit heating a heating object;

a support unit that supports the surface heater unit; and

a heat conducting unit disposed in contact with a surface of the surface heater unit at a side opposite to a side adjacent to the heating object in a region between a center of the heater portion in a direction crossing the longitudinal direction and the support unit.

2. The heating device according to claim 1 , wherein the heat conducting unit is disposed near the support unit in a region between the center of the heater portion in the direction crossing the longitudinal direction and an end portion of the support unit that is adjacent to the heater portion.

3. The heating device according to claim 2 , wherein the heat conducting unit is disposed in contact with the support unit.

4. The heating device according to claim 1 , wherein the heat conducting unit is disposed on each side of the heater portion in the direction crossing the longitudinal direction.

5. The heating device according to claim 4 , wherein the heat conducting unit includes a heat pipe having a circular shape with an outer diameter of less than or equal to 3 mm in cross section.

6. The heating device according to claim 1 , wherein the heater portion of the surface heater unit is one of a plurality of heater portions arranged in the direction crossing the longitudinal direction.

7. The heating device according to claim 6 , wherein the heat conducting unit comprises a plurality of heat conducting units that correspond to the heater portions disposed at both ends in the direction crossing the longitudinal direction.

8. A fixing device comprising:

a first rotating body that rotates and in which a heating unit is disposed to oppose a region through which a recording medium holding a toner image passes; and

a second rotating body that rotates while pressing the recording medium toward the heating unit of the first rotating body,

wherein the heating device according to claim 1 is used as the heating unit.

9. An image forming apparatus comprising:

an image forming unit that forms a toner image on a recording medium; and

a fixing unit that fixes the toner image formed on the recording medium,

wherein the fixing device according to claim 8 is used as the fixing unit.