Abstract: A backlight unit includes alight guide plate, an inner frame that surrounds an outer periphery of the light guide plate, and an outer frame that surrounds an outer periphery of the inner frame. An inner periphery of the inner frame is formed with an inner protrusion that projects toward the outer periphery of the light guide plate. The outer periphery of the inner frame is formed with an outer protrusion that projects toward an inner periphery of the outer frame. The inner protrusion and the outer protrusion are located on opposite sides of a wall part that is one side part of the inner frame, and arranged at a distance from each other in a longitudinal direction of the wall part of the inner frame. According to the backlight unit, relative positional displacement of members can be suppressed while ensuring the ease of assembling.

Abstract: A cathode ray tube has an anode and a focus electrode. The large-diameter cylinder portion of the focus electrode is disposed concentrically within a large-diameter cylinder portion of the anode. The anode and a first electrode facing a cathode side end of the focus electrode are electrically connected together within the cathode ray tube. The following relationship is satisfied: −LP+184.9≧LG4≧0.0004 LP3−0.1571 LP2+21.006 LP−922.41, where LG4 (mm) is an axial length of the focus electrode, and LP (mm) is a distance from a phosphor screen side end of the focus electrode to a center of a phosphor screen.

Abstract: A lens structure of a pre-focus part of an Hi-UPF electron gun to be used for a cathode ray tube has a cathode, a control electrode, an acceleration electrode, a first anode, a focus electrode and a second anode arranged in this order. The first anode and the second anode are to be commonly supplied with an anode voltage, and the focus electrode is to be supplied with a focus electrode. In a cathode ray tube of this construction, in the pre-focus part, the control electrode has an electrode beam passage hole of 0.57 mm or smaller and the distance in the vicinity of the electron beam passage hole between the acceleration electrode and the first anode is 1.9 mm or smaller.

Abstract: A cathode ray tube has an anode and a focus electrode. The large-diameter cylinder portion of the focus electrode is disposed concentrically within a large-diameter cylinder portion of the anode. The anode and a first electrode facing a cathode side end of the focus electrode are electrically connected together within the cathode ray tube. The following relationship is satisfied: −LP+184.9≧LG4≧0.0004 LP3−0.1571 LP2+21.006 LP−922.41, where LG4 (mm) is an axial length of the focus electrode, and LP (mm) is a distance from a phosphor screen side end of the focus electrode to a center of a phosphor screen.

Abstract: A cathode ray tube has an anode of a large-diameter cylinder portion on its phosphor screen side and a small-diameter cylinder portion on its cathode side connected together, and a focus electrode formed of a large-diameter cylinder portion of a diameter larger than that of the small-diameter cylinder portion of the anode and a small-diameter cylinder portion having a diameter smaller than that of the small-diameter cylinder portion of the anode, the large-diameter and small-diameter cylinder portions being connected together. The large-diameter cylinder portion of the focus electrode is disposed concentrically within the large-diameter cylinder portion of the anode. The anode and a first electrode facing a cathode side end of the focus electrode are electrically connected together within the cathode ray tube. The following relationship is satisfied: −LP+184.9≧LG4≧0.0004 LP3−0.1571 LP2+21.006 LP−922.41, LP≧131.

Abstract: A cathode ray tube has an anode of a large-diameter cylinder portion on its phosphor screen side and a small-diameter cylinder portion on its cathode side connected together, and a focus electrode formed of a large-diameter cylinder portion of a diameter larger than that of the small-diameter cylinder portion of the anode and a small-diameter cylinder portion having a diameter smaller than that of the small-diameter cylinder portion of the anode, the large-diameter and small-diameter cylinder portions being connected together. The large-diameter cylinder portion of the focus electrode is disposed concentrically within the large-diameter cylinder portion of the anode. The anode and a first electrode facing a cathode side end of the focus electrode are electrically connected together within the cathode ray tube. The following relationship is satisfied: −LP+184.9≧LG4≧0.0004 LP3−0.1571 LP2+21.006 LP−922.41, LP≧131.

Abstract: A cathode ray tube has a gun electrode construction which elongates horizontally a cross section of an electron beam and whose elongating strength weakens as a focusing voltage increases.

Abstract: A novel internal magnetic shield support apparatus for a color picture tube is disclosed, in which a mask frame is fixed on the interior of the periphery of a panel of the color picture tube, an internal magnetic shield is arranged along the inner wall surface of a funnel of the color picture tube, and the internal magnetic shield is secured to the mask frame with a buffer member interposed therebetween.