Patent ID: 7227300
Filing Date: 2007-06-05
Classification: H01J

Abstract:
1. A projection tube apparatus comprising: a valve comprising a face panel having a screen face on its external face, a funnel connected to a rear portion of the face panel, and a neck portion; an electron gun that emits an electron beam and is housed in the neck portion; and a deflection device mounted at an outer circumference of the funnel on the neck portion side; wherein the deflection device at least comprises: horizontal deflection coils that generate a horizontal deflection field for deflecting the electron beam in a horizontal direction; vertical deflection coils that generate a vertical deflection field for deflecting the electron beam in a vertical direction and is disposed outside the horizontal deflection coils; and a core disposed outside the vertical deflection coils; and wherein a distance Ls between an end portion of the horizontal deflection coils on the screen face side and the screen face is set to 55 mm≦Ls≦80 mm.