Lowe, Price, LeBlanc, Becker & Shur
Color display tube with shadow mask and fabricating method thereof
 A shadow mask (13) in accordance with the present invention comprises: an iron plate (14) having many apertures (15) for electron beams, wherein each of the apertures comprises a relatively medium diameter portion (15c), a relatively smaller diameter portion (15b), a relatively larger diameter portion (15a) in order from one side of the plate in which said one side is to be irradiated by the electron beam; a first surface-treated layer of Fe.sub.3 O.sub.4 which covers the allover surface of the plate; and a second layer (5) for preventing thermal strain of the plate caused by heat due to energy of the electron beams, wherein said second layer is applied over said first layer only on said one side of the plate. 
Mitsubishi Denki Kabushiki Kaisha
H H H H
H01J H01J H01J H01J
additional additional inventional inventional
Tetsuya
Watanabe