Safety apparatus for controlling operation of functional equipment having movable parts

A safety apparatus for controlling operation of functional equipment having movable parts, said apparatus having a camera configured to view and cause detection of safety related event in a field of view of the camera, characterized in

• that a background area is in the field of view, said background area in a part thereof exhibiting a set of stationary markings,
• that a fraction of sensor matrix pixels in the camera is dedicated to providing an image of said markings, said fraction of pixels readable by a hardware configured operating unit,
• said operating unit has a set of stored reference pixel signal values which are respectively related to pixels in said fraction of sensor matrix pixels, and which are related to said background area and said array of distinguished markings thereon,
• said operating unit is hardware configured to compare a read pixel signal value from a respective pixel in said fraction of pixels with corresponding reference signal value assigned to such respective pixel, and to output respective comparison signal, and
• that said operating unit has an output capable of changing its signal state of delivered signal when said comparison signal or a set of such comparison signals departs from a predefined condition, said delivered signal when in the form of a disabling or deactivating signal is effective to cause disablement or halted operation of said functional equipment.