Novel Laser Scanning Technology for Computed Radiography

DESCRIPTION (provided by applicant): The goal of this project is to improve the size, robustness, patient throughput and image quality of Computed Radiography systems. Operational efficiencies are increasingly driving the industry toward digital imaging. C omputed radiography equipment is generally less expensive than digital radiography systems, but is perceived as offering somewhat lower image quality, and a lower patient throughput. Our technology would enable computed radiography to compete more effectiv ely on an image quality and throughput basis, while maintaining its cost advantage in terms of capital expense. We propose to apply a technology that has recently become available, i.e. Vertical Cavity Surface Emitting Laser (VCSEL) arrays in the l aser scanning source. VCSEL arrays can be fabricated monolithically on a single chip with a very precise spacing and good performance uniformity. The array can replace the flying spot scanners which use a single laser and a rotating mirror. This will resul t in a more compact and more robust scanner. In addition, the technology enables a linescan mode of operation. This ability shifts the normal trade-offs between scan speed and image quality to a more favorable point. Such linescan units have been demonstra ted with discrete lasers, but the manufacturing of such systems is challenging. Our project will test the feasibility of this approach by evaluating the performance of available laser arrays, and then incorporating these laser arrays into a demonst ration board that includes the VCSEL array, a lens array, and driver circuitry. The performance characteristics of the demo board relevant to computed radiography performance will be evaluated. The demonstration board will then be incorporated into a syste m, and the modulated transfer function (MTF) of the system will be measured and compared to a standard system. In a Phase II program, a full size prototype would be built, and the performance of scanners operated in both point scan and linescan mode would be fully characterized.