Line-scanning three-dimensional sensing system

A line-scanning three-dimensional (3D) sensing system for measuring a surface profile of an object, the system comprising:

• a light source module for generating a polychromatic light beam;
• a first slit optically coupled to the light source module for spatially filtering the polychromatic light beam to form a polychromatic linear light beam (PLLB);
• a first dispersion optical module (DOM) configured to perform a forward optical process of chromatically dispersing the PLLB received from the first slit into constituent narrowband linear light beams (CNLLBs) and focusing the CNLLBs on different focal planes to form a rainbow light pattern, the rainbow light pattern being used for illuminating a scanned surface of the object during surface profile measurement so as to cause the illuminated object to display an IBCI on the object, the IBCI containing height information of the scanned surface;
• a second DOM configured to capture the IBCI and to perform a backward optical process of optically condensing the captured IBCI to an elongated light pattern, wherein the backward optical process is an inverse of the forward optical process, and the first and second DOMs are positioned side by side;
• a bi-passed lens module configured to reposition the rainbow light pattern generated by the first DOM to an offset position at which the object is arranged to position, and to direct the IBCI from the offset position to the second DOM for enabling the second DOM to capture the IBCI;
• and
• a second slit for spatially filtering the elongated light pattern to form an output light line, whereby a height profile of the scanned surface is obtainable by analyzing a spectral content at each point of the output light line such that the surface profile is determinable according to respective height profiles obtained for a plurality of scanned surfaces of the object.

A line-scanning three-dimensional (3D) sensing system for measuring a surface profile of an object, the system comprising:

• a light source module for generating a polychromatic light beam;
• a first slit for spatially filtering the polychromatic light beam to form a polychromatic linear light beam (PLLB);
• a dispersion optical module (DOM) configured to:
• perform a forward optical process of chromatically dispersing the PLLB received from the first slit into constituent narrowband linear light beams (CNLLBs) and focusing the CNLLBs respectively on different focal planes to form a rainbow light pattern for illuminating a scanned surface of the object during surface profile measurement, whereby the illuminated object is caused to display an information-bearing color image (IBCI) on the object, the IBCI containing height information of the scanned surface;
• capture the IBCI;
• and
• perform a backward optical process of optically condensing the captured IBCI to form an elongated light pattern, wherein the backward optical process is an inverse of the forward optical process;
• a second slit for spatially filtering the elongated light pattern to form an output light line, whereby a height profile of the scanned surface is obtainable by analyzing a spectral content at each point of the output light line such that the surface profile is determinable according to respective height profiles obtained for a plurality of scanned surfaces of the object;
• a grating for diffracting the output light line to thereby form a spectral image of the output light line;
• an imaging sensor for imaging the spectral image, the spectral content at each point of the output light line being determinable from the spectral image;
• a collimating lens module positioned between the second slit and the grating for collimating the output light line before the output light line is diffracted by the grating;
• a condenser lens module positioned between the grating and the imaging sensor for focusing the spectral image onto the imaging sensor;
• and
• a prism for reflecting the spectral image emitted from the grating to the condenser lens module, the prism being configured to redirect the spectral image such that the collimating lens module and the condenser lens module are oriented mutually perpendicularly to each other to thereby enable convenient alignment and assembling of the collimating lens module and the condenser lens module.