Patent ID: 7778565

Claim:
A heating device comprising: a magnetic field generating unit that generates a magnetic field; and a heat generating body including a heat generating layer which is disposed so as to oppose the magnetic field generating unit and which generates heat due to electromagnetic induction of the magnetic field, and a temperature-sensitive layer which has a Curie temperature from a set temperature of the heat generating layer to a heat-resistant temperature of the heat generating layer, and which is disposed at a side of the heat generating layer opposite a side at which the magnetic field generating unit is disposed, such that heat from the heat generating layer is conducted, wherein at temperatures less than or equal to the Curie temperature of the temperature-sensitive layer, the following formula (A) and formula (B) are satisfied, and, at temperatures exceeding the Curie temperature of the temperature-sensitive layer, the following formula (A) and formula (C) are satisfied: t ⁢ ⁢ 1 < 503 ⁢ ρ1 ( μ ⁢ ⁢ r ⁢ ⁢ 1 · f ) formula ⁢ ⁢ ( A ) δ ≥ 503 ⁢ ρ ⁢ ⁢ 2 ( μ ⁢ ⁢ r ⁢ ⁢ 2 · f ) formula ⁢ ⁢ ( B ) δ ≥ 503 ⁢ ρ ⁢ ⁢ 2 ( μ ⁢ ⁢ r ⁢ ⁢ 2 · f ) formula ⁢ ⁢ ( C ) wherein, in the above formulas, 1, t1, r1 are respectively a specific resistance, a thickness, and a relative magnetic permeability of the heat generating layer, and 2, r2 are respectively a specific resistance, a thickness, and a relative magnetic permeability of the temperature-sensitive layer, and f is a frequency of an alternating magnetic field of the magnetic field generating unit.