Patent ID: 8421934

Claim:
A method for aligning an optical element ( 2 ) on a display screen ( 1 ) with pixels x(i,j) in a grid of rows (i) and columns (j) for creating a display screen for three-dimensional display, comprising the following steps: presenting a test pattern consisting of different views A(k) with k=1, . . . , n and n>1, wherein n<6 or n>7, on the pixels x(i,j) with rows (i) and columns (j), the test pattern comprising at least two first straight lines ( 6 a , 6 b ) and at least two of these lines ( 6 a , 6 b ) being arranged in different horizontal positions in the n views A(k) each, and with the test pattern comprising at least two second straight lines ( 7 a , 7 b ) each of which is aligned in parallel with one of the first straight lines ( 6 a , 6 b ) and each of which is arranged in at least the same horizontal positions in the n views A(k); observing the presented test pattern through the optical element ( 2 ) from a defined distance by means of a two-dimensional camera ( 3 ); aligning the optical element ( 2 ) in front of the display screen ( 1 ) in such a way that, in an image which is recorded by the camera ( 3 ) of the presented test pattern each first straight line ( 6 a , 6 b ) seamlessly merges into at least one appropriately arranged second straight line ( 7 a , 7 b ), and that all first and second straight lines ( 6 a , 6 b , 7 a , 7 b ) are displayed in said image straight and without breaks; wherein the alignment of the optical element ( 2 ) relative to the display screen ( 1 ) with pixels x(i,j) is, with regard to the rotatory position of the optical element ( 2 ) relative to the display screen ( 1 ), exactly defined with a tolerance of maximally 3 minutes of arc; and wherein the alignment of the optical element ( 2 ) relative to the display screen ( 1 ) with pixels x(i,j) is, with regard to the horizontal position of the optical element ( 2 ) relative to the display screen ( 1 ), exactly defined with a tolerance of maximally the width of a pixel x(i,j).