摘要 |
<p>An optical filter device is disclosed made up of a bandpass filter (13) and a circularly polarizing filter (14) and is typically used in front of the faceplate of a cathode ray tube (10) in a high intensity ambient light environment, such as with navigation displays in some aircraft cockpits, to reduce the high intensity ambient light striking the phosphor of the cathode ray tube and thus effect a reduction in the level of the scattered light that causes a washout of the display thereon, thereby permitting observation of the display on the tube.</p> |