Drop centering device
AssigneeVarioptic S.A.
InventorBruno Berge
Life of this patent
Estimating the term…
Abstract
A method for centering a drop of liquid (2) on a given point on a surface (4). The inventive method consists in forming a bell-mouthed recess (6), whereby said recess has a curvature at any point at the limit of contact between the drop and the recess that is lower than or opposite to the curvature of a circle (TC) that is tangent to the surface of the recess to said point and at a symmetrical point (CP2) of said surface.
Claims33
A method for centering a liquid drop (2) at a given location of a surface (4), comprising the step of forming at this location a flared hollow (6) such that, at any point (CP1) of the contact limit between the drop and the hollow, said hollow has a curvature smaller than or opposite to that of a circle (TC) tangent to the hollow surface at said point and at a symmetrical point (CP2) of this surface.
A method for centering a liquid drop (14) on the external surface of a convex surface (16), comprising the step of giving this surface at any point (CP1) of the contact limit with the drop a shape such that this surface has a curvature greater than that of a circle (TC) tangent to this surface at this point and at a symmetrical point (CP2) of this surface.
A variable-focus lens, comprising:
- a wall made of an insulating material (4),
- a drop of an insulating liquid (2) arranged on an area of a first surface of the wall,
- a conductive liquid (8) covering the first surface and the drop, the insulating and conductive liquids being non-miscible, having different optical indexes and substantially the same density, and
- means (12) for applying an electric voltage (V) between the conductive liquid and an electrode (10) arranged on a second surface of said wall,
- wherein the drop is centered in a flared hollow (6) that has been formed in the wall so that, at any point (CP 1) of the contact limit between the drop and the hollow, said hollow has a curvature smaller than or opposite to that of a circle tangent to the hollow surface at said point and at a symmetrical point of this surface.
A variable-focus liquid lens comprising:
- a transparent dielectric enclosure layer (4) having a first and second surfaces;
- an axis (O) associated with the dielectric enclosure layer, oriented orthogonal to the first surface;
- a hollow (6) defined on the first surface of the dielectric enclosure layer, the hollow being centered on the axis (O);
- a first electrode (10) provided on the second surface of the dielectric enclosure layer and having a hole (11) centered on the axis (O);
- a drop of an insulating liquid (2) placed in the hollow and centered on the axis (O);
- a conductive liquid (8) covering the drop of the insulating liquid and the first surface of the dielectric enclosure layer, the two liquids being non-miscible, having different optical indices and substantially the same density, wherein a dioptre formed between the insulating liquid and the conductive liquid forming a surface of the liquid lens, the optical axis of which is the axis (O);
- a second electrode (12) in contact with the conductive liquid for applying an electric voltage (V) between the conductive liquid and the electrode (10);
- and
- the hollow having a curvature, wherein at any point (CP1) of contact limit between the drop and the hollow, the hollow's curvature is smaller than or opposite to that of a circle tangent to the hollow's surface at the point of contact limit.
A method for centering a liquid drop at a given location of a surface comprising:
- providing the drop on the surface, the surface having at least one sidewall, such that, at any point of the contact limit between the drop and the surface, said surface has a curvature smaller than or opposite to that of a circle tangent to the surface at said point and at a symmetrical point of the surface.
A variable-focus lens comprising:
- a wall made of an insulating material and defining a cavity having at least one sidewall;
- a drop of an insulating liquid arranged on a first surface of the wall;
- a conductive liquid covering the drop, the insulating and conductive liquids being non-miscible, having different optical indexes and substantially the same density;
- and
- a voltage source configured to apply an electric voltage between the conductive liquid and an electrode arranged on a second surface of said wall,
- wherein the wall has a shape such that, at any point of the contact limit between the drop and the first surface, said first surface has a curvature smaller than or opposite to that of a circle tangent to the first surface at said point and at a symmetrical point of the first surface, for centering the drop.
A variable-focus liquid lens comprising:
- a transparent dielectric enclosure layer having first and second surfaces, the first surface defining at least one sidewall;
- an axis associated with the dielectric enclosure layer, oriented orthogonal to the first surface at a point;
- a first electrode provided on the second surface of the dielectric enclosure layer and having a hole encompassing the axis;
- a drop of an insulating liquid disposed on the first surface and centered on the axis;
- a conductive liquid covering the drop of the insulating liquid, the two liquids being non-miscible, having different optical indices and substantially the same density, wherein a dioptre formed between the insulating liquid and the conductive liquid forming a surface of the liquid lens, the optical axis of which corresponds with the axis;
- a second electrode in contact with the conductive liquid for applying an electric voltage between the conductive liquid and the electrode;
- and
- the first surface having a curvature, wherein at any point of contact limit between the drop and the first surface, the first surface's curvature is smaller than or opposite to that of a circle tangent to the first surface at the point of contact limit.
A method of varying the focal length of a lens, comprising:
- providing a lens structure comprising an insulating drop on a surface, the surface having at least one sidewall, the shape of the surface being such that, at any point of the contact limit between the drop and the surface, said surface has a curvature smaller than or opposite to that of a circle tangent to the surface at said point and at a symmetrical point of the surface, for centering the drop, a conducting liquid covering the insulating drop, and an electrode;
- and
- changing a voltage applied between the electrode and the conducting liquid to thereby change the area of the surface which the insulating liquid contacts.
Dependencies are inferred from the claim text.