| 摘要 |
PURPOSE:To easily and correctly enable purity measurement of a cathode-ray tube by generating a magnetic field at the front space of the objective lens of a multiplying mirror, and deviating an electron beam with the magnetic field. CONSTITUTION:Inside a lens mirror cylinder 10, an objective lens 11 is arranged on the large diameter side end thereof, and a magnetic field coil 13 and a magnetic field core 14 both of which composing a magnetic portion of a magnetic field generator are arranged so as to sandwich the lens 11. By operating the magnetic field generator during observation of purity of a cathode-ray tube, a specific magnetic field is applied to an electron beam inside visual area of a magnifying mirror, and thereby a boundary portion of electron beam concealed by black stripe can be seen on each phosphor, and then the whole form and position of electron beam irradiated to each phosphor can be confirmed. It is thus possible to measure the purity state of the cathode-ray tube easily and correctly. |
