Some of the main applications of machine vision include automatic inspection and gauging (measurement). There are many examples where inspection by the human eye can be replaced and, in most cases, enhanced with the use of machine vision. For many applications, machine vision is the only way to accomplish the task due to advantages of high precision, high speed, and capability of operating in harsh environments. In industry, machine vision is often synchronized with other systems such as motion systems and data acquisition. By using vision algorithms, the movement of a specific object can be measured with respect to time. Also, the motion of the objects can be analyzed. The defects of a product can be inspected and dimensions of an object can be measured rapidly in real time. Information obtained from machine vision can be used for real-time automated motion control, quality assurance, measurement feedback, and process control. Machine vision applications are now essential to many different industries such as manufacturing, semiconductor, surveillance, automobile, and medical applications.
In this chapter, a few examples of machine vision applications will be discussed.
18.1 Semiconductor Manufacturing
In the field of semiconductor industry, machine vision has been used for inspection, positioning, and alignment of substrates. For example, photolithography of VLSI circuits requires critical alignment of an optical mask to prepatterned ...