EXPOSURE DEVICE FOR FORMING PHOSPHOR SCREEN

• Main Author: MAEDA SHIYOUICHI
• Format: Patent
• Language: English
• Published: 18.04.1984
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

PURPOSE:To cancel the positional shifting of a shadow mask without losing the advantages of an exposure device by making the lengthwise direction of a slit parallel to the vertical axis of a face panel and the lengthwise direction of a lamp discharge luminescent section parallel to an axis that is inclined by an acute rotary angle (theta) from the horizontal axis of the face panel. CONSTITUTION:A slit plate 6 covering a ultrahigh pressure mercury lamp 5 is provided so that the lengthwise direction of the slit plate 7 can be parallel to the vertical axis Y-Y' of a face panel 9 and the ultrahigh pressure mercury lamp 5 is arranged so that the lengthwise direction of the narrow and long discharged luminescent section 10 can be parallel to an axis A-A' that is inclined counterclockwise by a rotary angle theta (acute angle) from a horizontal axis X-X'. Thus, the optical exit point i.e. the exposure point of a lamp 5, especially viewed from the periphery on the lower side of a correction lens system 8 is moved counterclockwise as compared with the case where the inclination of the rotary angle (acute angle) is not applied. As a result, the collision point namely the exposed point by an exposing light beam that is particularly incident on the periphery of a photosensitive coat provided on the inner surface of the face panel 9 through a shadow mask is moved and positional shifting can be canceled.