A memory array includes first and second sets of conductors and a plurality of memory-diodes, each connecting in a forward direction a conductor of the first set with a conductor of the second set. The concentration of the impurity ions contained in that part of the liquid crystal layer which is located inside the display area is lower than the concentration of the impurity ions contained in that part of the liquid crystal layer which is located outside the display area. The frame has a first frame wall and a second frame wall arranged with a first gap in between that extends along the first frame wall.