||An infrared ceiling sensor network system is reported in this study to realize fall detection of a single person in the home environment. The sensors output multiple binary sequences from which we know the existence/nonexistence of persons under the sensors. The short duration averages of the binary responses are shown to be able to be regarded as pixel values of a top-view camera, but more advantageous in the sense of preserving privacy. Such "pixel values" usage enables us to measure the moving speed of users, and thus detect falls of a single person. The detected rate of fall forward obtained the best performance of 85.71%. Except for the falling vertically, we obtained the average detected rate of 73.68%.