This　paper　describes　the　fabrication　of　backlight　units　(BLUs)　for　a　liquid　crystal　display　(LCD)　based　on　a　novel　planar-gate　electron　source　with　patterned　carbon　nanotubes　(CNTs)　formed　by　electrophoretic　deposition.　The　electric　field　distributions　and　electron　trajectories　of　this　triode　structure　are　simulated　according　to　Ansys　software.　The　device　structure　is　optimized　by　supporting　numerical　simulation.　The　field　emission　results　show　that　the　emission　current　depends　strongly　on　the　cathode-gate　gap　and　the　gate　voltage.　Direct　observation　of　the　luminous　images　on　a　phosphor　screen　reveals　that　the　electron　beams　undergo　a　noticeable　expansion　along　the　lateral　direction　with　increasing　gate　voltage,　which　is　in　good　agreement　with　the　simulation　results.　The　luminous　efficiency　and　luminance　of　the　fabricated　device　reaches　49.1　lm/W　and　5500　cd/m2,　respectively.　All　results　indicate　that　the　novel　planar-gate　electron　source　with　patterned　CNTs　may　lead　to　practical　applications　for　an　electron　source　based　on　a　flat　lamp　for　BLUs　in　LCD.　©　2013　Chinese　Institute　of　Electronics.