| 摘要 |
<p>An improved transparent touch panel membrane switch (10) for use and shielding in front of a visual display terminal is disclosed. The switch is made up of a plurality of plastic sheets (11, 12) arrayed substantially parallel to one another in a sandwich configuration. The outermost of the sheets (11) has an antireflective hardcoat (19). Two adjacent but spaced apart inner sheets (17, 31) provide the electrical contacts through transparent low reflectance conductive metal coatings (20, 32). The switch additionally contains a further inner antireflective transparent electrically conductive coating (33) which provides shielding against the passage of electromagnetic and radio frequency interference through the membrane switch. The layers in this switch all contribute to a relatively low transmittance of back lighting from the visual display terminal but also significantly reduce reflectance such that the overall signal to noise ratio is substantially enhanced.</p> |
