Aperture construction for a mobile camera

• US 7,585,122 B2
• Filed: 03/15/2006
• Issued: 09/08/2009
• Est. Priority Date: 03/15/2006
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Erom ki, Marko
• Primary Examiner(s): Koval; Melissa J
• Application Number:
  US11/377,905
• Publication Number:
  US 20070216803A1
• Time in Patent Office: 1,273 Days
• Field of Search: 396/262, 396/457, 396/506, 396/448, 359/273, 359/248, 359/249, 348/68
• US Class Current: 396/506
• CPC Class Codes: G02B 13/0075 having an element with variable optical properties
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 5/005 Diaphragms for cameras G03B9/02
• CPC Class Codes: G03B 7/085 for control of aperture
• CPC Class Codes: G03B 9/02 Diaphragms

Abstract

An adjustable aperture construction for a camera comprises at least two electrodes, and an electrical circuit for applying a voltage to the electrodes in order to create an electric field between the electrodes. In addition the construction comprises a center unit with a hole in the middle as an aperture, where the center unit is made of an electroactive material and placed essentially between the electrodes. The center unit is then deformed, expanded or retracted by applying the electric field between the electrodes using the electrical circuit thereby adjusting the aperture in the center unit.

Claims

1. An adjustable aperture construction for a camera, the adjustable aperture construction comprising:

at least two electrodes,

an electrical circuit for applying a voltage to the electrodes in order to create an electric field between the electrodes,

a center unit with a hole in the middle as an aperture, the center unit being made of an electroactive material and placed essentially between the electrodes, and

where the center unit is deformed, expanded or retracted by applying the electric field between said electrodes using said electrical circuit and thereby adjusting the aperture in the center unit.

2. An adjustable aperture construction according to claim 1, wherein said center unit is adapted to expand and retract the aperture in the middle of said center unit, when said electric field is applied.

3. An adjustable aperture construction according to claim 1, wherein said center unit is essentially circular comprising a hole essentially in the midpoint.

4. An adjustable aperture construction according to claim 1, wherein said center unit is made of dielectric material.

5. An adjustable aperture construction according to claim 1, wherein said center unit is made of electrostrictive polymer.

6. An adjustable aperture construction according to claim 1, wherein the aperture size is controlled with operating voltage of the electrical circuit.

7. An adjustable aperture construction according to claim 1, wherein the aperture size is measured by capacitance or resistance of the electrical circuit applying the voltage to the electrodes.

8. A mobile camera comprising an adjustable aperture construction, the adjustable aperture construction comprising:

at least two electrodes,

an electrical circuit for applying a voltage to the electrodes in order to create an electric field between the electrodes,

a center unit with a hole in the middle as an apenure, the center unit being made of an electroactive material and placed essentially between the electrodes, and

where the center unit is deformed, expanded or retracted by applying the electric field between said electrodes using said electrical circuit and thereby adjusting the aperture in the center unit.

9. Method for adjusting an aperture of a camera, the adjustable aperture construction comprising:

at least two electrodes,

an electrical circuit for applying a voltage to the electrodes in order to create an electric field between the electrodes,

a center unit with a hole in the middle as an aperture, the center unit being made of an electroactive material and placed essentially between the electrodes,

the method comprising;

deforming, expanding or retracting the center unit by applying the electric field between said electrodes using said electrical circuit, and

thereby adjusting the aperture in the center unit.

10. Use of a deformable electroactive material in adjustable aperture construction for a camera, the adjustable aperture construction comprising:

at least two electrodes,

an electrical circuit for applying a voltage to the electrodes in order to create an electric field between the electrodes,

a center unit with a hole in the middle as an aperture, the center unit being made of said deformable electroactive material and placed essentially between the electrodes,

the use comprising;

deforming, expanding or retracting the center unit by applying the electric field between said electrodes using said electrical circuit, and

thereby adjusting the aperture in the center unit.