Abstract: An optically variable pigment being formed from optically variable flakes. The optically variable multilayer is vacuum deposited onto a flexible polyester substrate having being provided with a release layer. An optically variable stack is formed from an opaque metallic reflective layer and two sub-unit film stacks D'MD symmetrically stacked on the opposite surfaces of the metallic reflective layer. D is adjacent to the reflective layer and is a color-presenting layer and D' is an outer layer of the stack which is used to protect the multilayer film to obtain better color-presenting. M is a semitransparent metallic layer, e.g. chromium.

Abstract: A traffic signal device having a single, continuously-illuminating lamp and several plain reflectors constructed by optical thin film technique to receive the light beam projected from the lamp and respectively reflecting light components of pre-determined wavelengths to display differently-colored traffic signals. Also, is a lamp detection system which monitors and detects the operation of the lamp and generates a signal to actuate the lamp interchanging mechanism to automatically replace the lamp with a spare lamp once the lamp malfunctions.