Abstract: This invention concerns a table top game capable of being played on a reversible table surface having a football playing field on one side and a rugby playing field on the opposite side. Each game is suitably marked with the necessary markings and preferably contains a green base to simulate the real game. Opposite ends of the game include goal posts that may either be fixed or removable, depending on the wishes of the user. A flexible reversible table surface is also described together with a fixed reversible table surface capable of being played on any supporting surface including the floor. Each of the games is played with a miniature ball that is kicked off by a flip of a player's finger.

Abstract: In a pattern recognition system the video output signal is a signal representative of either black or white. The shading effect of the video camera is minimized by using a high pass filter to accentuate the high frequency components of the signal by partially differentiating the substantially square wave input video signal and feeding forward a sample of the undifferentiated signal thereby retaining some low frequency components of the video signal and thereby minimizing the shading effect of the video camera without increasing detected noise components. Positive and negative-going zero crossings with respect to ground are detected through a capacitive coupled comparator circuit. In the absence of zero crossings the discharge circuit and charge circuit of the capacitor is interrupted thereby maintaining the value of the voltage on the capacitor with respect to ground. Changing the charge and discharge rate of the capacitor reduces the probability that noise on the signal will cause a false zero crossing.