Measurement and analsis methods for critical flicker frequency and observer fatigue caused by television watching

Aiming at the quantitative measurement of the fatigue of the television observer, a new practical and simple method of critical flicker frequency (CFF) measurement and analysis is considered. As to the measurement, a method is considered where the CFF at the start of the measurement is used as the initial value and the relative change is measured in a short time with a high accuracy. It is verified experimentally that the measurement by the descending series of the method of limit is suitable. As to the analysis, two methods are compared. One is to normalize the average of measured values of all the observers, and the other is to normalize the measured value of each observer and then to calculate the average. It is shown as a result that the latter can represent more clearly the change of CFF. Then the effectiveness of the proposed method in the measurement of the fatigue of the television (TV) observer is examined. CFF of the actual TV image observer is measured, including the binocular three-dimensional (3-D) TV. As a result, it is verified statistically that CFF depends on the observation time and the image display method. the result corresponds well to the subjective evaluation of the fatigue. Thus, it is concluded that CFF can be a useful measure in assessing quantitatively the fatigue of the TV image observer, including the binocular 3-D TV. It is expected that the image quality and the improvement effect of the observation condition can be examined quantitatively.