Methods for producing lens arrays
A lens array for imaging image elements in an object plane, and a method of making a lens array. The lens array includes lenslets formed in or on one side of a transparent or translucent material with the image elements disposed on the opposite side, and has a gauge thickness corresponding to the distance from the apex of each lenslet to the object plane. Each lenslet has a set of lens parameters. The gauge thickness and/or at least one lens parameter is or are optimized such that each lenslet has a focal point size in the object plane which is either substantially equal to the size of the image elements in the object plane, or varies from the size of the image elements by a predetermined amount.
1. A method of manufacturing a display device, comprising the steps of:
providing m images of an object, wherein m is at least equal to 2,
dividing each image into sets of adjacent arrays of picture elements, spaced at a mutual distance,
applying the adjacent arrays of picture elements from each image in an interlaced manner on an image layer in sets of interlaced arrays below a lens structure comprising line-shaped lens elements over the image layer with one line shaped lens element overlying a corresponding set of adjacent arrays,
wherein upon applying the arrays onto the image layer, and/or upon providing the lens elements, each array of picture elements is provided onto the image layer in an out-of-focus manner to form a blurred array, or each array is imaged by the lens elements to form a blurred array, wherein a mutual distance of edges of adjacent blurred arrays is smaller than the mutual distance by which the adjacent arrays of picture elements are spaced.
2. A method according to claim 1 , wherein the array of picture elements is provided onto the image layer in an out-of-focus manner by means of printing.
3. A method according to claim 1 , wherein the array of picture elements is provided onto the image layer by laser marking.
4. A method according to claim 1 , wherein the edges of adjacent blurred arrays are substantially touching.
5. A method according to claim 1 , wherein each picture element has a width, and each lens element has an effective focal width in the image layer, and wherein the width of each picture element is increased relative to the effective focal width of each lens element, or the effective focal width of each lens element is increased relative to the width of each picture element such that the increase in width of the picture elements caused by applying the arrays in an out-of-focus manner is between 0% and 20%.
6. A display device comprising an array of lens elements overlying an image layer with sets of interlaced arrays of picture elements produced by the method according to claim 1 .
7. A display device comprising
a substrate, an image layer, and a number of line-shaped lens elements,
wherein the image layer comprises interlaced arrays of picture elements, the lens elements being situated a distance t above the image layer,
wherein a focal plane of the lens elements is situated at distance f from the lens elements,
wherein f is either larger or smaller than t, and each picture element has a width, each of the lens elements has an effective focal width at the image layer which varies from the width of the picture elements by a predetermined amount, and wherein the predetermined amount by which the effective focal width varies from the width of the picture elements is not more than 20% of the size of the picture elements.