Patent ID: 7723641

Claim:
An automated breaking line system for a brittle material substrate, the automated breaking line system comprising: a device for breaking the brittle material substrate; and a scribing device for scribing a brittle material substrate, said scribing device continuously heating a region along a line to be scribed on a surface of the brittle material substrate at a temperature lower than a softening point of the brittle material substrate and continuously cooling a region in the vicinity of the heated region such that a blind crack along said line to be scribed is formed, said scribing device including: a light source for emitting light; a polarizing beam splitter splitting light from said light source based on a polarization state, said polarizing beam splitter transmitting light in a polarization direction; an optical fiber receiving light split via said polarizing beam splitter, said optical fiber guiding said light split via said polarizing beam splitter such that light enters the region of the blind crack formation in an area of the cooled region on the surface of the brittle material substrate, said optical fiber receiving the light reflected by the blind crack such that said optical fiber transmits said light to said polarizing beam splitter; a light reception element receiving reflected light from said blind crack via said polarizing beam splitter; and a determination unit including a window comparator means for determining whether an amount of light received via said light reception element is within a predetermined upper light receiving threshold Vref 1 and a predetermined lower light receiving threshold Vref 2 to provide a comparator means output, said predetermined upper light receiving threshold Vref 1 being greater than said predetermined lower light receiving threshold Vref 2 , said determination unit determining a formation state of the blind crack based on said output from said window comparator means, said formation state of the blind crack being a defective formation state when said amount of light received via said light reception element is greater than said predetermined upper light receiving threshold Vref 1 or less than said predetermined lower light receiving threshold Vref 2 , said formation state of the blind crack being a normal formation state when said level of light received via said light reception element is greater than or equal to said predetermined lower light receiving threshold Vref 2 and less than or equal to said predetermined upper light receiving threshold Vref 1 .