A collector assembly with a radiation collector, a cover plate and a support member connecting the radiation collector to the cover plate are provided. It is determined whether a difference between a scheduled-travel distance scheduled in the predetermined travel pattern and an actual traveled distance exceeds a permissible value when the vehicle is traveled straight and a center value of the outputs of the angular velocity sensor is corrected when the difference is determined to exceed the permissible value. The frame includes an openable portion positioned to allow the LED module to be inserted or removed through an opening created when the openable portion is in an open position. In one embodiment, the imaging subsystem further includes an image generator located in the object field. Furthermore, the full color EPDs of the present invention are capable of displaying high contrast images of high color saturation. The lid cover is further formed having a hole and separate slot made through the dome-like surface and the lid insert provided with a convex surface made to be directed toward the dome-like surface with a tubular member further extending from the insert to engage the hole in the surface of the cover.