Patent ID: 7880375

Claim:
A triode cathode apparatus of a field effect display screen, said display screen including a plurality of pixels arranged in a matrix of rows and columns, said triode cathode apparatus comprising, per pixel: a first lower metallization level forming a cathode, said cathode being in a direction parallel to a longest length of one of the columns; an electrical insulating layer; a second higher metallization level including extraction grids in a form of bands parallel to a longest length of one of the rows of the field effect display screen, said extraction grids connected to each other through plural central grid conductors; plural grooves having a major dimension parallel to the longest length of one of the rows of the field effect display screen and formed in the second metallization level and in the electrical insulating layer; and an electron emission device disposed on lines of pads arranged in each groove parallel to the longest length of one of the rows of the field effect display screen, the electron emission device including electron emitters based on nanotubes or nanofibers made of carbon or silicon, wherein at least one pixel of the field effect display screen does not contain a lateral grid conductor connecting the bands to each other.