Abstract: The invention relates to a vacuum cup (1) that is able to ensure a very silent release of an object that is being held by the vacuum cup (1). The vacuum cup (1) comprises a channel (7) that allows a fast passage of ambient air into a vacuum chamber (3) to bring the vacuum chamber (3) to atmospheric pressure. Preferably, the channel (7) comprises openings (9, 9′, 13) that have surface area's being large compared to the surface area of a top (10) of the vacuum chamber (3) in order to obtain a fast release.

Abstract: The method of successively positioning and fixing n plates forming a stack (21-26) relative to a mounting face (20), includes the positioning and alignment, if necessary, of n plates (21.varies.26), each plate (21-26) being retained, after it has been positioned relative to the mounting face (20) or relative to plates (21-25) which have already been positioned, by means of a vacuum in a vacuum pipe in the plates (21-25) already positioned. When all plates (21-26)are positioned and retained by a vacuum system connected to vacuum apertures (201-206) in the mounting face (20), successive plates (21-26) can be fixed relative to each other so as to form the stack of n plates (21-26). The vacuum pipes form ducts in the plates (21-25), at least one duct comprising i (i=1,2,3, . . . , n-1) corresponding apertures (215; 214, 224; 213, 223, 233; 212, 222, 232, 242; 211, 221, 231, 241, 251) in i plates (21-25) and being closed by a plate i+1 (21-26). Such stacks are used in thin-type display devices.