Patent ID: 8106858
Filing Date: 2012-01-31
Classification: G09G

Abstract:
1. A display board comprising an array of addressable light emitting elements and driving means for driving the light emitting elements with image data, the display board furthermore comprising aging determination means comprising: at least one reference light emitting element, the driving means being adapted for driving the at least one reference light emitting element with calibration data, light measurement means for measuring light emitted by the reference light emitting element, and for measuring light representative of the light emitted by the light emitting elements, and comparison means for comparing measured light emitted by the reference light emitting element with measured light representative of the light emitted by the light emitting elements and for, based on the comparison result, deciding on aging of the light emitting elements in the array; wherein the at least one reference light emitting element comprises at least a first and second reference light emitting element, the driving means being adapted for driving the first reference light emitting element at first moments in time with reference data equal to a value derived from the image data for driving the light emitting element of the array and with first calibration data at second moments in time so as to emit light representative of the light emitted by the light emitting elements, and for driving the second reference light emitting element at the second moments in time with second calibration data, wherein the light measurement means is adapted for measuring light emitted by the first and second reference light emitting element, and wherein the comparison means is adapted for comparing measured light emitted by the first reference light emitting element with measured light emitted by the second reference light emitting element and for, based on the comparison result, deciding on aging of the light emitting elements in the array.