A light emitting device having excellent characteristics such as light emitting efficiency and the like and electrical equipment provided with such a light emitting device and having high reliability are provided. A number of electrical contact points with which contact may be created via electrical contact elements are provided on one side of the sensor element. The pendulum movement of the pipe cathode is preferably such that the pipe cathode is rotated by a certain first angle in a first direction and subsequently by a certain second angle in a second direction, the second angle differing from the first angle. The processing unit produces a second image data according to the first image data and produces an image parameter according to the second image data.