Uniform laser scanning in a hematology analyzer

The author´s objective for this work was to find the least expensive motor with the best linearity and repeatability for a rotating and scanning mirror used in a hematology analyzer instrument. The design criterion was a minimal acceptable error of 3% for the worst segment length. The galvanometer and the floppy disk motor were selected as the best candidates for further testing. All testing was repeated with ten additional floppy disk motors, and similar results occurred. In addition, life testing and temperature testing were conducted again with no significant changes. A stable oscillator circuit controls the speed of the floppy disk motor. Even if the absolute motor speed changed slightly over temperature or time, as long as it stayed uniform during the scans, the calculated segment length values did not change. The floppy disk drive motor with a mirror mounted on the shaft of the motor was the best candidate. The motor´s speed came close to the desired scanning speed