(57) A video display device comprises
- a plurality of light emitting elements (1-1, 1-2, ..., 1-n) arranged in a matrix
having rows and columns;
- a plurality of first current modulators (2-1, 2-2, ..., 2-n), each of which is associated
to one of said light emitting elements(1-1, 1-2, ..., 1-n), for drawing a feed current
of programmable intensity (ID1, ID2, ..., IDn) for the associated light emitting element (1-1, 1-2, ..., 1-n) from a circuit node
(3) associated to each of said columns;
- a current generator (11) controlled by video data representative of desired luminosities
(D1, D2, ..., Dn) of said light emitting elements for supplying a first current (IDATA) to said circuit node (3), the intensity of which is representative of a desired
luminosity (D1, D2, ..., Dn) of at least one of said light emitting elements (1-1,
1-2, ..., 1-n);
the circuit node (3) having a specific voltage level when the intensity supplied by
said current generator (11) is drawn from the current node (3) by the first current
modulator (2-1, 2-2, ..., 2-n) associated to said at least one light emitting element(1-1,
1-2, ..., 1-n);
- a second current modulator (10) for supplying a second current (I10) to said circuit node (3);
- a comparator (7) having inputs connected to said circuit node (3) and to a reference
terminal which is constantly held at said specific voltage level and an output connected
to a control input of said second current modulator (10), whereby the second current
(I10) from said second current modulator (10) is controlled so as to yield said specific
voltage level at the circuit node (3).
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