Shoichi Aoyama

Evaluation of viewing distance vs. TV size on visual fatigue in a home viewing environment

We evaluated viewing distance vs. TV size on visual fatigue using two kinds of visual content: a 42-inch PDP display (Experiments 1 and 2), and the effect of TV size on visual fatigue with a 65-inch PDP display (Experiment 3). The results indicate that optimum viewing distance for less visual fatigue lies between 165 and 220 cm, indicating as a semi-absolute distance, rather than the strict relative distance like three times of the screen height (3H).

Relationship between Viewing Distance and Visual Fatigue in Relation to Feeling of Involvement

In this study, we carried out experiments to measure the effect of viewing distance on visual fatigue using two kinds of visual content. Both experiments showed that visual fatigue reached a minimum at a distance of 3 to 4 times the height of the display (3---4H) and that sympathetic nerve activity peaked at around 3H. These results indicate that the viewing distance for less visual fatigue and a closer feeling of involvement might be in between the two distances. These indices, which we adopt in this study, have the potential to be effective evaluation indices for measuring visual fatigue taking feeling of involvement into consideration.

Measurement of visual fat igue for large-sized TVs in a home viewing environment

The authors report here the result of the evaluation experiments that measured visual fatigue for large-sized TVs in a home viewing environment using 42-inch and 65-inch PDP displays by physiological and psychological measurements. Our results indicate that the optimum viewing distance for minimizing visual fatigue lies between 165 and 220 cm, a semi-absolute distance, rather than a strict relative distance such as three times the screen height (3H). Moreover these results indicate that the viewing distance for less visual fatigue and a closer feeling of involvement might be in between the two distances.

Relationship between Emotional State and Pupil Diameter Variability under Various Types of Workload Stress

We carried out two experiments to explore the relationship between the frequency characteristic of pupil diameter variability and emotional state under various types of workload. The workload required the subjects to listen to spoken words and categorize them. The difficulty of the task was adjusted by changing the time interval of the stimulus presentation in Experiment 1 (time-based task) and the number of categories in Experiment 2 (cognitive-based task). Pupil diameter was monitored and recorded using an infrared video camera while observers were performing the tasks. In both experiments, a significant correlation was observed between the frequency characteristic of pupil diameter variability and emotional state. Our results indicated the frequency characteristic of pupil diameter variability to be a potentially useful index for evaluating mental stress.

P-29: Physiological and Psychological Measurements of Visual Fatigue for TVs in a Home Viewing Environment

In this study, we experimentally evaluated visual fatigue for large-Sized TVs in a home viewing environment by physiological and psychological measurements using 42- and 65-inch PDP displays with two kinds of content. for less visual fatigue, the results indicate that the optimum viewing distance lies between 165 and 220 cm, indicating a semi-absolute distance, rather than such a strict relative distance as three times the screen height (3H). Moreover these results indicate that the viewing distance for less visual fatigue and a closer feeling of involvement might be found in between the two distances.