There is disclosed a large-sized transmission-type screen used for a multi-image system. If the screen expands or contracts due to variations of the ambient temperature or humidity, generation of creases or relieves is prevented. The transmission-type screen includes image sources for projecting and magnifying optical images, screen members for transmitting the projected optical images, first light-blocking members mounted to edges of the screen members, and a support member having tensioning mechanisms. Each tensioning mechanism applies a tension to the first light-blocking members to hold the components of the screen members in intimate contact with the support member. Each screen member includes a lenticular lens sheet, a composite Fresnel sheet consisting of sheet members bonded vertically, and plural transparent reinforcing sheets. Each reinforcing sheet is substantially identical in size with each sheet member of the composite Fresnel sheet. A second light-blocking member is bonded between the two adjacent transparent reinforcing sheets to prevent the optical images from the adjacent image sources from overlapping.