Feasibility study for reconstruction of information from near field observations of the magnetic field of laser printer

We measured leaked electromagnetic radiation that came from a laser printer. Using the measured data, we were able to easily reconstruct the printed image. To avoid unwanted monitoring, we have to prevent the printed image data from being reconstructed. In this paper, we first measured the magnetic field at a near field point and then reconstructed the image. Then, using the Sommerfeld integration model, we calculated the magnetic field shielding required to reduce the emitted radiation to a level where the image could not be constructed. From the calculation results, we found that we can easily attenuate the electromagnetic wave by using a thin shielding sheet and we can not remake the image if the distance from the noise source to observation point is more than 30 mm.