Focus mesh structure and biasing technique for flat panel display devices

Claim 1

In a flat panel display device having a display area where the sequential impingement of electrons along successive lines effects a visual display, and including a beam guide structure having electron beam propagation means for propagating at least one electron beam along paths substantially parallel to said display area, and having means for focusing electron beams traveling toward said display area, said display device also including extraction means arranged substantially perpendicular to said beam propagation means and substantially parallel to said successive lines for repelling said at least one electron beam from said beam propagation means toward said display area for scanning along said lines, an improvement wherein said means for focusing includes a plurality of apertured focus meshes arranged in a spaced and parallel relationship with respect to one another and with respect to said electron beam propagation means, each of said focus meshes including apertures arranged in at least one column along the length of said meshes and in the direction of electron beam propagation, the apertures in the respective focus meshes being off set in the direction of electron beam propagation, said extraction means including a plurality of extraction electrodes extending along one dimension of said display area and perpendicular to said at least one column.