| 摘要 |
A flashing beacon includes a xenon tubular lamp 1 that extends transversely to the axis 3 of symmetry of a cylindrical collimating lens 2 that surrounds the lamp 1. Two pairs of right-angled prisms 4 are located centrally one either side of the lamp 1 with the prisms 4 of each pair redirecting light emitted by the lamp 1 in opposite directions 6 lengthwise of the lamp 1 to ensure a substantially uniform distribution about the axis 3 of light transmitted via the lens 2. In one embodiment (Figures 3-5), pairs of prisms (17) are provided in a one-piece moulding (13) with the lens (15), all within a moulded cover (14), whereas in another example (Figures 6-7), the prisms (24) are as one-piece with a domed cover-moulding (21) that has internal Fresnel-lens stepping (22). The beacon may be used for alarm or warning purposes such as burglar or fire alarm systems, or on police, ambulance or fire service vehicles. |
