This technique, called quatrix (for quasi-matrix), has potential application in numerous communication and datahandling areas, since it provides high-density matrix-photocell capability at much lower cost. The method uses a few photographically-produced precision coding masks fitted over an equal number (

) of photocells. Thus, ten (

) typical high-detectivity photocells and ten coding masks will produce 2
10(2
N) binary combinations, behaving like a 32 by 32 matrix photodetector and using only 10 preamps. Twenty larger cells and preamps promise a million element matrix. Limitations are discussed.