| 摘要 |
PURPOSE:To obtain a sufficient sealing effect of the device by penetrating spiral lead wires of a good conductor through the inside of a link provided outside a heating chamber wall surface, allowing at least one winding of the spiral lead wires to exist in the link and setting the entire length of the lead wires sufficiently smaller than the wavelength. CONSTITUTION:At least one winding or more of spiral lead wires 7 having coil pitch intervals are allowed to exist in a link 5, and the dimension of the entire part of the lead wires 7 is set to satisfy nL<lambda (lambda represents a working wavelength; L, the length of one winding of the lead wire 7; and n, the number of turns of the lead wire). With this construction, the link part 5 and the lead wires 7 do not constitute a coaxial transmission line and have no radiation characteristics in the axial direction of a grill heater 4 from a microwave theory, that is, high-frequency energy leaking outside is not present. Further, the link 5 is provided in the outside direction of a heating chamber 1 so as to afford the same effect as in the case of increase in the apparent thickness of the plate, and further the lead wires 7 are formed by an electrically good conductor whereby the rise in the temperature within the link 5 is suppressed to a low value.
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