US 5,499,304 A · Light mask

Abstract

Apparatus for producing a light mask for balancing light across a display area of a vehicle instrument cluster comprises a camera, a digitiser and a computer. An image of the display area is obtained and digitized 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 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 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 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.

Claims25

Dependent claims

A method of producing a light mask for balancing light transmitted to a display area of an instrument comprising the steps of:

obtaining an image of at least part of the display area of the instrument;
defining an array of image areas, each of which image areas comprises part of the obtained image;
obtaining at least one illumination value representative of light intensity for each of the image areas;
selecting a reference illumination value;
determining an attenuation value for each of the image areas in dependence upon the obtained illumination values and the selected reference illumination value;
selecting a type of masking to be used for fabricating a light mask, the type of masking having defined light attenuating properties;
determining an amount of masking required for each of the image areas on the basis of the determined attenuation value and the light attenuating properties of the type of masking to be used;
generating masking data for the production of the light mask on the basis of the amount of masking required for each image area;
and
fabricating the light mask for balancing light transmitted to the display area of the instrument based upon the masking data.

7 more elements

Apparatus for producing a light mask for balancing light transmitted to a display area of an instrument comprising:

a camera for obtaining an image of the display area of the instrument;
image processing means coupled to the camera for forming a plurality of image areas, each of which image areas comprises part of the image of the display area of the instrument;
evaluating means coupled to the image processing means for obtaining at least one illumination value representative of light intensity for each of the image areas;
selection means for selecting a reference illumination value and a type of masking to be used for fabricating a light mask, the type of masking having defined light attenuation properties;
a processor coupled to the evaluating means and the selection means for determining an attenuation value for each of the image areas in dependence upon the obtained illumination values and the reference illumination value, and being adapted to determine the amount of masking required for each of the areas on the basis of the attenuation value and the light attenuation properties of the type of masking to be used;
and
generating means coupled to the processor for generating masking data for the fabrication of a light mask for balancing light transmitted to the display area of the intrument based upon the masking data.

4 more elements

Dependencies are inferred from the claim text.

Light mask

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Light mask

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Abstract

Claims25