| 摘要 |
A spectrum analyzer determines the light emission characteristics of an authentication mark that is invisible when illuminated with visible light but is visible when illuminated with IR light. The spectrum analyzer includes an IR light source, a mirror positioned to deflect light from the IR light source in a direction that is substantially perpendicular to a surface of the authentication mark, a first lens for collimating light that is emitted by the authentication mark in response to an illumination by the light from the IR light source, an optical element comprising a prism or a hologram for generating a spectrum from the collimated light, a second lens for imaging the spectrum, an IR light blocking filter, a detector positioned to receive light components of the spectrum after the spectrum has been imaged by the second lens and filtered by the IR light blocking filter, and a control unit connected to the detector and programmed to read the authentication mark based on intensities of the light components received by the detector. |
