Optical element

An optical device comprising:

• an optical element having a container and first and second liquids contained sealingly in said container, said first and second liquids being substantially equal in refractive index, said first and second liquids existing without mixing with each other, said first and second liquids differing from each other in transmittance, said first and second liquids making the boundary between said first and second liquids having a predetermined shape;
• an electrode formed in such a place as to avoid interference with passage of a bundle of rays incident upon said optical element;
• and
• a voltage application circuit for applying a voltage to said electrode,
• wherein the shape of the boundary between said two liquids is changed by application of a voltage through said electrode to change the quantity of transmitted light in the bundle of rays passing through said optical element.

A photo-taking device comprising:

• an imaging optical system for forming a subject image;
• an optical element for changing the quantity of transmitted light in a bundle of rays passing through said imaging optical system;
• image pick-up means for recording the subject image;
• said optical element having a container and first and second liquids contained sealingly in said container, said first and second liquids being substantially equal in refractive index, said first and second liquids existing without mixing with each other, said first and second liquids differing from each other in transmittance, said first and second liquids making the boundary between said first and second liquids having a predetermined shape;
• an electrode formed in such a place as to avoid interference with passage of a bundle of rays incident upon said optical element;
• and
• a voltage application circuit for applying a voltage to said electrode,
• wherein the shape of the boundary between said two liquids is changed by application of a voltage through said electrode to change the quantity of transmitted light in the bundle of rays passing through said optical element.

An optical device comprising:

• an optical element having a container having a side surface inclined at a predetermined angle from an optical axis, and first and second liquids contained sealingly in said container, said first and second liquids differing substantially from each other in transmittance, said first and second liquids existing without mixing with each other, said first and second liquids making the boundary between said first and second liquids having a rounded shape;
• an electrode formed in such a place as to avoid interference with passage of a bundle of rays incident upon said optical element;
• and
• an application circuit for applying a voltage to said electrode,
• wherein the shape of the boundary is changed by application of a voltage to change the refractive power with respect to light passing through said optical element.

A photo-taking device comprising:

• an imaging optical system for forming a subject image:
• a variable-power optical element incorporated in said imaging optical system, said variable-power optical element including a container having a side surface inclined at a predetermined angle from an optical axis, and first and second liquids contained sealingly in said container, said first and second liquids differing substantially from each other in refractive index, said first and second liquids existing without mixing with each other, said first and second liquids making the boundary between said first and second liquids having a rounded shape;
• an electrode formed in such a place as to avoid interference with passage of a bundle of rays incident upon said optical element;
• and
• image pick-up means for recording the subject image.