Patent ID: 8875652

Claim:
A system for controlling a boundary of spreading liquid adhesive on a surface, comprising: one or more ultra-violet (UV) sources configurable to emit UV light onto the liquid adhesive; a detection circuit, comprising: an infrared transmitter that emits infrared light onto the liquid adhesive; and an infrared receiver that receives infrared light that is reflected off the liquid adhesive and that detects locations at which the boundary of the liquid adhesive has spread beyond a predetermined region on the surface; a control circuit coupled to the one or more UV sources, wherein upon detecting that the boundary of the liquid adhesive has spread beyond the predetermined region, the detection circuit is configured to send a signal to the control circuit to control the one or more UV sources to selectively apply the UV light only at the detected locations on the liquid adhesive to cure the adhesive and prevent the boundary of the adhesive from further spreading beyond the predetermined region.