An absorbent product comprises a seal along one or more edges. Under those conditions, it is hypothesized that environmental anomalies, such as energy spikes, which ultimately can be harnessed as an energy source, may occur along or proximate to the circumferential beam path. A sliding bearing composed of a sliding material having a sliding surface which slides on a mating member and a lubricating oil supply layer which supports the sliding material and supplies the sliding surface with the lubricating oil. The long and short sides respectively form first and second inclined angles with respect to the light emission surface and the first included angle is smaller than the second included angle and the first inclined angle gets smaller with the associated light-guiding structure located closer to the lengthwise end.