Optical system comprising a curved image sensor
The invention relates to an optical system ( 1 ) comprising: a first focus tunable lens ( 10 ), a curved image sensor ( 30 ) configured to receive light (L) focused by the first focus tunable lens ( 10 ); an optical path (P) extending through the first focus tunable lens and to the curved image sensor; wherein the optical system ( 1 ) is configured to tune the focal length of the first focus tunable lens ( 10 ) by applying an electrical signal to the first focus tunable lens ( 10 ) such that light (L) traversing said optical path (P) is focused onto the image sensor ( 30 ).
1. An optical system ( 1 ) comprising: a first focus tunable lens ( 10 ), a curved image sensor ( 30 ) configured to receive light (L) focused by the first focus tunable lens ( 10 ); an optical path (P) extending through the first focus tunable lens and to the curved image sensor; wherein the optical system ( 1 ) is configured to tune the focal length of the first focus tunable lens ( 10 ) by applying an electrical signal to the first focus tunable lens ( 10 ) such that light (L) traversing said optical path (P) is focused onto the image sensor ( 30 ); the first focus tunable lens ( 10 ) comprises a membrane ( 12 ) having a deformable portion ( 12 a ), a filler material (M) adjacent said membrane ( 12 ), and a corrective lens ( 60 ) comprising a fixed position with respect to the image sensor ( 30 ): wherein the corrective lens ( 60 ) contacts the filler material (M) of the first focus tunable lens ( 10 ), and is configured to correct monochromatic or polychromatic aberrations.
2. The optical system of claim 1 , characterized in that the optical system ( 1 ) further comprises a second focus tunable lens ( 40 ), wherein the second focus tunable lens ( 40 ) is arranged in said optical path (P), and wherein the second focus tunable lens ( 40 ) is configured to operate with the first focus tunable lens ( 10 ) to focus light (L) traversing the optical path (P) onto the image sensor ( 30 ).
3. The optical system of claim 2 , characterized in that the first focus tunable lens ( 10 ) and/or the second focus tunable lens ( 40 ) each comprise one of the following components configured for tuning the respective focal length: an actuator means ( 3 ), an electrostatic actuator means, an electromagnetic actuator means, a magnetostrictive actuator means, a piezo actuator means, a piezo motor, a stepper motor, an electroactive polymer actuator means.
4. The optical system of claim 1 , characterized in that the first focus tunable lens ( 10 ) comprises a lens body ( 11 ) arranged in the optical path (P) for refracting light (L) passing through the lens body ( 11 ), wherein said lens body ( 11 ) comprises at least one surface ( 11 a ) arranged in said optical path (P), which at least one surface ( 11 a ) is configured to change its shape, particularly from a concave shape to a convex shape or vice versa.
5. The optical system of claim 2 , characterized in that the second focus tunable lens ( 40 ) comprises a lens body ( 41 ) arranged in the optical path (P) for refracting light (L) passing through the lens body ( 41 ), wherein said lens body ( 41 ) comprises at least one surface ( 41 a ) arranged in said optical path (P), which at least one surface ( 41 a ) is configured to change its shape, particularly from a convex shape to a concave shape or vice versa.
6. The optical system of claim 1 , characterized in that the corrective lens ( 60 ) is made out of a rigid material.
7. The optical system of claim 1 , characterized in that the first focus tunable lens ( 10 ) comprises a liquid crystal ( 9 ) for adjusting the focal length of the first focus tunable lens ( 10 ), and/or wherein a second focus tunable lens ( 10 , 40 ) comprises a liquid crystal ( 9 ) for adjusting the focal length of the second focus tunable lens ( 40 ).
8. The optical system of claim 1 , characterized in that the first focus tunable lens ( 10 ) is configured to use electrowetting for adjusting the focal length of the first focus tunable lens ( 10 ), and/or wherein a second focus tunable lens ( 40 ) is configured to use electrowetting for adjusting the focal length of the second focus tunable lens ( 40 ).
9. The optical system of claim 1 , characterized in that the first focus tunable lens ( 10 ) comprises a piezo actuator means ( 3 ) for tuning the focal length of the first focus tunable lens ( 10 ), a glass membrane ( 12 ) and a deformable polymer layer ( 5 ); and/or wherein a second focus tunable lens ( 40 ) comprises a piezo actuator means ( 3 ) for tuning the focal length of the second focus tunable lens ( 40 ), a glass membrane ( 12 ) and a deformable polymer layer ( 5 ).
10. The optical system of claim 1 , characterized in that the first focus tunable lens ( 10 ) comprises a thermal compensation means ( 100 , 300 , 500 , 13 , 210 ) being configured to minimize thermal drift of the focal length of the first focus tunable lens ( 10 ); and/or wherein a second focus tunable lens ( 40 ) comprises a thermal compensation means ( 100 , 300 , 500 , 13 , 210 ) being configured to minimize thermal drift of the focal length of the second focus tunable lens ( 40 ).
11. The optical system of claim 1 , characterized in that optical system ( 1 ) is configured to adjust the focal length of the first and/or a second focus tunable lens ( 10 , 40 ) using an algorithm which uses calibration data, temperature or another feedback signal to set a value of a control signal (S) to achieve the desired focal length.
12. An optical system ( 1 ) comprising:
a first focus tunable lens ( 10 ),
a curved image sensor ( 30 ) configured to receive light (L) focused by the first focus tunable lens ( 10 ); an optical path (P) extending through the first focus tunable lens and to the curved image sensor;
wherein the optical system ( 1 ) is configured to tune the focal length of the first focus tunable lens ( 10 ) by applying an electrical signal to the first focus tunable lens ( 10 ) such that light (L) traversing said optical path (P) is focused onto the image sensor ( 30 );
wherein the optical system ( 1 ) further comprises at least one first corrective lens ( 20 ) arranged in the optical path (P), which at least one first corrective lens ( 20 ) is non-tunable and comprises a fixed position with respect to the image sensor ( 30 ) and is made out of a rigid material, preferably a material having a fixed refractive index, and wherein the at least one first corrective lens ( 20 ) is configured to correct for one of monochromatic aberrations, spherical aberrations, or polychromatic aberrations.
13. An optical system ( 1 ) comprising:
a first focus tunable lens ( 10 ),
a curved image sensor ( 30 ) configured to receive light (L) focused by the first focus tunable lens ( 10 ); an optical path (P) extending through the first focus tunable lens and to the curved image sensor;
wherein the optical system ( 1 ) is configured to tune the focal length of the first focus tunable lens ( 10 ) by applying an electrical signal to the first focus tunable lens ( 10 ) such that light (L) traversing said optical path (P) is focused onto the image sensor ( 30 );
wherein the optical system ( 1 ) further comprises a second corrective lens ( 50 ) arranged in the optical path (P), which second corrective lens ( 50 ) is non-tunable and comprises a fixed position with respect to the image sensor ( 30 ) and is made out of a rigid material, preferably a material having a fixed refractive index, and wherein the second corrective lens ( 50 ) is arranged between the image sensor ( 30 ) and the first focus tunable lens ( 10 ), wherein preferably the first focus tunable lens ( 10 ) is arranged closer to the image sensor ( 30 ) than the second focus tunable lens ( 40 ).