A BLACK-FIELD ILLUMINATED SHIPBOARD CLOCK
Research and development rept.
NAVY MARINE ENGINEERING LAB ANNAPOLIS MD
Pagination or Media Count:
An illuminated, bulkhead-mounting, clock was developed that has outstanding conspicuity in the low-level luminous environments of combat information centers and darkened radar and sonar spaces. This development applies the Black-Field photoluminescent illumination technique to effect a unique presentation of hour, minute, and sweep-second hands as well as graduations and numerals in high contrast against a virtually black background. Although the lamp that feeds the optical system is in line-of- sight, it cannot be seen. The dial is of the see thru type and consists of numerals and graduations processed on the inner surface of the black-light absorbing dial-window. The design features of the initial lot of preprototype clocks are described. The applicability of this technique to the illumination of other military displays is noted and it is recommended that a program be undertaken to develop near ultraviolet transmitting almost visually opaque plastic filters to replace glass where structural or manufacturing considerations make its use undesirable. Author
- Test Facilities, Equipment and Methods