Abstract: A transmission type projection screen assembly comprises a relatively thin flexible screen, and a plurality of small force receiving blocks fixed at spaced-apart positions in a horizontal row to the flexible screen along the upper and lower edges thereof. Spring devices are inserted between adjacent small blocks so that constant horizontal tension is applied to the screen to prevent wrinkling and deflection thereof. A horizontal support beam is fixed to a screen support frame and suspendingly supports the flexible screen via the upper small blocks, and a relatively rigid screen is placed in flush contact with the flexible screen and rests on the lower small blocks. The weight of the rigid screen applies vertical tension to the flexible screen so that wrinkling and deflection of the flexible screen is further prevented.