Patent EA-002670-B1 (EA)
Title: Heating member with resistive surface
IPC: H05B3/36
Filed: 1999-08-10
Abstract: 1. Heating member with resistive surface (1) comprising at least one resistive layer (10) with contact electrodes (11, 12) and two conductive layers (20, 30) arranged above the resistive layer (10) as well as insulating layers (40, 50) arranged between each of the layers (10, 20, 30), characterized in that the first conductive layer (20) following after the resistive layer (10) is realized as a neutral conductor, connected with the resistive layer (10) via contact electrodes (12, 21) provided at the two layers (10, 20) and the next-following second conductive layer (30) is realized as a protective ground to be grounded via a contact electrode (31). 2. Heating element according to claim 1, characterized in that the resistive layer (10) has one contact electrode (11, 12) each in the border region on two sides, and the first and second conductive layer (20, 30) have one contact electrode (21, 31) each in the border region, the contact electrodes (11, 12, 21, 31) protrude in a longitudinal direction on at least one side beyond the corresponding layers (10, 20,30), and one contact electrode (12) of the resistive layer (10) in projection is superimposed with the contact electrode (21) of the first conductive layer (20) while the contact electrode (31) of the second conductive layer (30) is offset relative to the contact electrode (12) of the resistive layer (10) or to the contact electrode (21) of the first conductive layer (20). 3. Heating element according to claim 1 or 2, characterized in that in a horizontal and/or vertical direction, the contact electrodes (11, 12,21,31) are arranged essentially parallel to each other. 4. Heating element according to one of the claims 1 to 3, characterized in that on the sides of the second conductive layer (30) and of the resistive layer (10) that face away from the other layers, one more insulating layer (60, 70) each is arranged. 5. Heating element according to one of the claims 1 to 4, characterized in that the ends of the contact electrodes (11, 12, 21,31) protruding beyond the conductive layers (20, 30) or the resistive layer (10) each are covered by the insulating layers (40, 50, 60, 70) enveloping these layers. 6. Heating element according to one of the preceding claims, characterized in that the resistive layer (10) comprises carbon black or an electroconductive polymer as the resistive mass. 7. Heating element according to one of the preceding claims, characterized in that the resistive layer (10), the first and the second conductive layer (20, 30) all consist of the same material. 8. Heating element according to one of the preceding claims, characterized in that at least one insulating layer serves as a supporting layer for the corresponding adjoining conductive layer(s). 9. Heating element according to one of the preceding claims, characterized in that in the resistive layer (10) and in the first and second conductive layer (20, 30), openings (14, 24, 34) in the plane are provided, these openings (14, 24, 34) being superimposed in projection. 10. Heating element according to one of the preceding claims, characterized in that the resistive layer (10) and the two conductive layers (20, 30) each have a conductive material in subdivisions (23, 33) while the resistive layer (10) has at least two contact electrodes (11,12, 11', 12') and the first and second conductive layer (20, 30) each have at least one contact electrode (21, 21', 31, 31') each associated with a contact electrode pair of the resistive layer (10) which extend in a longitudinal direction in the corresponding layer (10,20, 30) and protrude at least on one end beyond the subdivisions (13,22, 32) provided with conductive material or with resistive mass. 11. Heating element according to claim 10, characterized in that the contact electrodes (11, 11', 12,12', 21,21', 31, 31') extend over the entire length of the heating element (1). 12. Heating element according to one of the claims 10 and 11, characterized in that the subdivisions (13,23, 33) provided with resistive mass or conductive material extend over the entire width of the heating element (1). 13. Heating element according to one of the claims 10 to 12, characterized in that the band-shaped gaps situated between the subdivisions (13,23, 33) of the corresponding layers (10,20, 30) are free of resistive mass and conductive material. 14. Heating element according to one of the claims 10 to 13, characterized in that the subdivisions (13,23, 33) of the individual layers (10, 20, 30) in projection are superimposed. 15. Heating element according to one of the preceding claims, characterized in that the layer thickness of peripheral insulating layers is 50-200 μm and that of internal insulating layers is 10-100 μm. 16. Heating element according to one of the preceding claims, characterized in that the layer thickness of the conductive layers is 10-3000 μm, the layer thickness of the first conductive layer (20) preferably being 10-50 μm and that of the second conductive layer (30) preferably being 50-100 μm.