causes the surface of each liquid portion 13b to become rounded and prevents the portions from running the spaces between base material portions 13b prevent neighboring portions 13b from fusing together as they melt when portions 13b are allowed to harden the array of square microlenses or the master for its production is completed when this master is used to produce a stamping mold or the stamping mold is used to mass produce an array of square microlenses the processes are the same as those shown in fig5 an alternative process by which base material portions 13b can be produced is to begin by forming supports for portions 13b and then hardening these supports by irradiating them with deep uv rays base material portions 13b can then be formed on these supports in various embodiments of the present invention the apertures can have different shapes for example as shown in fig1 and 11 in these embodiments all of the six or more sides are straight lines or the sides are curved it is desirable that apertures be chosen which can as far as possible provide uniform openings and which will be easy to arrange i e apertures which are highly efficient in their use of light the apertures can be arranged in a number of ways such as strips so that the phases of the rows and columns coincide i e both rows and columns have a regular formation as a delta arrangement so that the phase of every row and or column is shifted by half a period half a pitch or randomly.