PURPOSE: To prevent the deterioration of the image display performance when a screen is extended/contracted by arranging engaging rod bodies along at least the two arms of the screen and imparting tensile force to the screen engaged with the engaging rod bodies.
CONSTITUTION: Sleeve like engaging members 4a - 4d are attached to the four arms of the screen 2 along the longitudinal directions of the arms and sewed up thereto. Rod bodies 6a - 6d are inserted through the engaging members 4a - 4d, extended along the arms of the screen 2 and connected with each other to be fixed at right angles, whereby a lectangular frame body is formed. Moreover, the rod bodies 6a - 6d are provided with pressurized coil springs 8a - 8d in their center parts so as to be extensive/contractive in their longitudinal directions with these spring parts. Thus, the flatness of the screen can be maintained and its image display performance can be prevented from deteriorating when the screen is extended/contracted in responce to change in an environmental condition.
NISHIZAWA TAMOTSU
YADA YUKIO
Next Patent: METAL NONWOVEN FABRIC AND METHOD FOR PRODUCING THE SAME