LIGHT MASK

摘要

Apparatus for producing a light mask 34 for balancing light across a display area 14 of a vehicle instrument cluster 10 comprises a camera 52, a digitiser 54 and a computer 56. An image of the display area 14 is obtained and digitised to produce data relating to the illumination levels of the image at a plurality of pixels. The illumination levels are used to calculate an appropriate light mask for the display area 14 on the basis of the transmissive density of the masking ink used and of a reference illumination value relating to the least lit part of the display area which it is desired to illuminate. The light mask 34 comprises an array of dots having a diameter related to the amount of attenuation required in the area in which the dot is located. Up to three masking layers 34 may be provided if a single layer is insufficient to produce the required attenuation with the chosen masking ink. Balanced coverlays can readily be produced, and the number of masking layers required can also be reduced.