| 摘要 |
PROBLEM TO BE SOLVED: To provide an information leakage prevention device which prevents leakage of electromagnetic waves from a window.SOLUTION: An information leakage prevention device includes a special structure unit 1 where a plurality of cells, each having a special structure for absorbing the electromagnetic waves of a specific frequency formed therein, are arranged in array on a transparent sheet and provided as a line pattern, an incident angle-sensitive unit 2 for sensing the incident angle of the electromagnetic waves impinging on each cell forming a special structure, and a frequency control unit 3 having a recording section recording the electromagnetic wave absorption characteristics depending on the application voltage of the special structure, and the harmonic data, i.e., the harmonic components of dot clock frequency of a computer. Frequency components matching the harmonic components of dot clock frequency of the electromagnetic wave radiated from the computer is attenuated, by applying a predetermined voltage, depending on the frequency identified by the harmonic data and the incident angle sensed by the incident angle-sensitive unit 2 to the special structure, based on the electromagnetic wave absorption characteristics recorded in the recording section. |
