US Patent 11465433 Security device and method of making thereof

A security device is provided, comprising: a colour shifting element that exhibits different wavelengths of light at different viewing angles, and; an at least partially transparent light control layer covering at least a part of the colour shifting element and comprising a surface relief adapted to modify the angle of light from the colour shifting element, wherein; a first region of the light control layer comprises a first optical characteristic, whereby light at a first viewing angle from the first region of the light control layer is perceived to have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the first optical characteristic, and; a second region of the light control layer either: (i) is substantially colourless such that light at the first viewing angle from the second region is perceived to have a resultant optical effect exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, or; (ii) comprises a second optical characteristic different from the first optical characteristic, whereby light at the first viewing angle from the second region of the light control layer is perceived to have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the second optical characteristic. Methods of manufacture thereof are also disclosed.