A gas cooking hob and a method of operating the hob including at least two physical cooking points and at least one electronic control component. The postprocessing apparatus further includes a recording unit for writing related information corresponding to image formed on the image forming member, onto the hologram recording medium. Then, when the distance between the display panel and the viewer is set to D, definition X of at least one of a vertical direction and a horizontal direction on a display plane of the display panel is set as in the following expression. The RF detectors are thermally coupled. This is done by adjusting the duty cycle of the grid-connected inverter. The second pivoting segment is pivotable relative to the first pivoting segment for selectively supporting the associated viewing device in a first, operational position before the eyes of a user donning the helmet and a second, stowed position above a line of sight of a viewer donning the helmet.