|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||52/171 ; 381/731 ; 381/191|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 12 인용 특허 : 9|
An anti-eavesdropping window structure in which the inner and outer panes, separated by a spacer frame have thickness d and D such that D/d is at least equal to 1.5. The space between the panes is filled with a gas mixture having a density in excess of that of air and a body-sound generator applied directly to the outer pane generates thermal noise over a frequency range of 200 to 3000 Hz to superimpose a level of such noise of at least 20 dB on transmitted sound.
An anti-eavesdropping window structure comprising: an outer transparent pane having a thickness d; an inner transparent pane having a thickness D such that D/d is at least equal to 1.5, said inner transparent pane being a composite pane having two glass sheets sandwiching a vibration damping glass-sheet-bonding layer between them; a spacer frame engaging the peripheries of said panes and defining with said panes and between said panes a chamber; a filling of a sound-damping gas having a density greater than that of air in said chamber; and at least one b...