Method of and apparatus for producing micro lens and micro lens

1. A method of producing a micro lens comprising the steps of

forming a transparent resin layer on a transparent substrate in a desired pattern,

causing the resin layer to absorb from its surroundings solvent which dissolves the resin so that the resin layer has fluidity and the surface of the resin layer becomes convex under the surface tension,

the dissolution of the resin progresses at room temperature,

then drying the solvent to use the convex portion of the resin as a lens, and

in which the surface of the substrate is coated with coating exhibiting liquid repellency to the resin which has absorbed the solvent and has been dissolved, from the resin layer side after forming the resin layer in a desired pattern and before causing the resin layer to absorb the solvent.

2. A method as defined in claim 1 in which a lens where the curvature in a cross-section parallel to the optical axis differs depending on the orientation is produced by patterning the resin layer into an ellipsoid or a polygon approximated thereto.

3. A method as defined in claim 1 in which the resin is held in the atmosphere of the solvent until the coating adhering to the surface of the resin is taken in the inside of the resin when causing the resin layer to absorb the solvent.

4. A method of producing a micro lens comprising the steps of

forming a resin layer on a transparent substrate in a desired pattern,

causing the resin layer to absorb from its surroundings solvent which dissolves the resin so that the resin layer has fluidity and the surface of the resin layer becomes convex under the surface tension,

the dissolution of the resin progresses at room temperature,

then drying the solvent,

dry-etching the substrate from the side on which the resin remains, thereby transferring the convex shape of the resin layer to the substrate,

forming a lens on the substrate, and

in which the surface of the substrate is coated with coating exhibiting liquid repellency to the resin which has absorbed the solvent and has been dissolved, from the resin layer side after forming the resin layer in a desired pattern and before causing the resin layer to absorb the solvent.

5. A method as defined in claim 4 in which an aspheric lens is produced by changing the etching rates of the resin and the substrate by continuously or stepwise changing etching conditions with time during the dry etching.

6. A method as defined in claim 4 in which a lens where the curvature in a cross-section parallel to the optical axis differs depending on the orientation is produced by patterning the resin layer into an ellipsoid or a polygon approximated thereto.

7. A method as defined in claim 4 in which the resin is held in the atmosphere of the solvent until the coating adhering to the surface of the resin is taken in the inside of the resin when causing the resin layer to absorb the solvent.

8. A method of producing a micro lens comprising the steps of

forming a resin layer on a substrate in a desired pattern,

causing the resin layer to absorb from its surroundings solvent which dissolves the resin so that the resin layer has fluidity and the surface of the resin layer becomes convex under the surface tension,

the dissolution of the resin progresses at room temperature,

then drying the solvent,

subsequently transferring the convex shape of the resin layer to another member to form a lens forming mold,

forming a lens by molding a transparent member on the basis of the lens forming mold, and in which the surface of the substrate is coated with coating exhibiting liquid repellency to the resin which has absorbed the solvent and has been dissolved, from the resin layer side after forming the resin layer in a desired pattern and before causing the resin layer to absorb the solvent.

9. A method as defined in claim 8 in which a lens where the curvature in a cross-section parallel to the optical axis differs depending on the orientation is produced by patterning the resin layer into an ellipsoid or a polygon approximated thereto.

10. A method as defined in claim 9 in which the resin is held in the atmosphere of the solvent until the coating adhering to the surface of the resin is taken in the inside of the resin when causing the resin layer to absorb the solvent.

11. A method of producing a micro lens forming mold comprising the steps of

forming a resin layer on a substrate in a desired pattern,

causing the resin layer to absorb from its surroundings solvent which dissolves the resin so that the resin layer has fluidity and the surface of the resin layer becomes convex under the surface tension,

the dissolution of the resin progresses at room temperature,

then drying the solvent, and

subsequently transferring the convex shape of the resin layer to another member to form a lens forming mold, and in which the surface of the substrate is coated with coating exhibiting liquid repellency to the resin which has absorbed the solvent and has been dissolved, from the resin layer side after forming the resin layer in a desired pattern and before causing the resin layer to absorb the solvent.

12. A method as defined in claim 11 in which the resin is held in the atmosphere of the solvent until the coating adhering to the surface of the resin is taken in the inside of the resin when causing the resin layer to absorb the solvent.

13. A method as defined in claim 1 , further comprising projecting ultraviolet rays onto an entirety of a surface to expose the entirety of the transparent substrate separate from forming the desired pattern of the resin layer.

14. A method as defined in claim 1 , wherein the drying the solvent comprises blowing inert gas onto the transparent substrate.

15. A method as defined in claim 1 , further comprising projecting ultraviolet rays onto a pattern mask of a closed curve corresponding to a desired cross-section of a lens curve.

16. A method as defined in claim 4 , further comprising projecting ultraviolet rays onto an entirety of a surface of the transparent substrate separate from forming the desired pattern of the resin layer.

17. A method as defined in claim 4 , wherein the drying the solvent comprises blowing inert gas onto the transparent substrate.

18. A method as defined in claim 4 , further comprising projecting ultraviolet rays onto a pattern mask of a closed curve corresponding to a desired cross-section of a lens curve.

19. A method as defined in claim 1 , wherein dissolution of the resin progresses at room temperature within a range from 20° C. to 25° C.

20. A method as defined in claim 4 , wherein dissolution of the resin progresses at room temperature within a range from 20° C. to 25° C.