Patent 6898890 was granted and assigned to american technologies network, corp. on May, 2005 by the United States Patent and Trademark Office.
A night-vision optical device of the invention with controlled life expectancy contains a time measuring device built into the housing of the aforementioned device for measuring the accumulated time of active work of the device. In application to a night scope for a firearm, the device also contains a sensor, which is interlocked with activation of the scope and reacts on the shots produced from the firearm in general and separately on those shots produced during active work of the night-vision optics at nighttime. The aforementioned shots of both types are counted and stored in separate memory units. The night-time shots affects the life expectancy of the night-vision optics because of muzzle flashes which cause such devices as an image intensifier to work with an increased light load. The information obtained from the time measuring device and the shot counter makes it possible to timely receive a warning signal about the fact that the night optics or the entire firearm must be replaced.