Wide field of view (FOV) optical lens assembly with tunable optical lens
An optical lens assembly with an electrically controlled, tunable optical lens with an attached aperture stop provides autofocus or similar functionalities in a camera with a wide field of view (FOV) (that is larger than 100 degrees in diagonal direction). The tunable optical lens is positioned between a first optical lens and a second optical lens in the optical lens assembly with the assembly including any number of negative or positive optical power lenses and/or other optical elements such as polarizers, quarter wave plates, optical filters, and similar ones. An optical profile of the tunable optical lens is modified through a voltage-controlled thin film piezo actuator based on a determined focus distance.
1 . An optical lens assembly, comprising:
a plurality of optical lenses aligned along an orthogonal axis respective of a plane of each of the optical lenses; and
a tunable optical lens positioned between a first optical lens and a second optical lens of the plurality of optical lenses, the tunable optical lens comprising:
a flexible membrane;
a hard substrate positioned parallel to the flexible membrane;
a deformable material between the flexible membrane and the hard substrate; and
at least two thin film piezo actuators to adjust a profile of the flexible membrane, wherein an adjustment of the profile of the flexible membrane adjusts a focus distance of the optical lens assembly, wherein the optical lens assembly has a field of view (FOV) of more than 100 degrees in a diagonal direction, an F number of more than 2 in a visible spectrum, an effective focal length of more than 2 mm, a total track length of 5 mm, and a back focal length of less than 1 mm.
2 . The optical lens assembly of claim 1 , wherein the deformable material comprises at least one of a polymer, a silicon compound, or a liquid lens.
3 . The optical lens assembly of claim 1 , further comprising:
an aperture stop on a surface of the tunable optical lens facing the first optical lens or the second optical lens.
4 . The optical lens assembly of claim 1 , further comprising:
an infrared (IR) blocking coating applied to an external surface of the hard substrate of the tunable optical lens.
5 . The optical lens assembly of claim 1 , wherein the first optical lens, a third optical lens, a fifth optical lens, and a sixth optical lens within the optical lens assembly have a negative optical power.
6 . The optical lens assembly of claim 1 , wherein the second optical lens and a fourth optical lens within the optical lens assembly have a positive optical power.
7 . An image capture device, comprising:
a controller;
a camera sensor; and
an optical lens assembly comprising:
a plurality of optical lenses aligned along an orthogonal axis respective of a plane of each of the optical lenses; and
a tunable optical lens positioned between a first optical lens and a second optical lens of the plurality of optical lenses, the tunable optical lens comprising:
a flexible membrane;
a hard substrate positioned parallel to the flexible membrane;
a deformable material between the flexible membrane and the hard substrate; and
at least two thin film piezo actuators to adjust a profile of the flexible membrane, wherein an adjustment of the profile of the flexible membrane adjusts a focus distance of the optical lens assembly, wherein the optical lens assembly has a field of view (FOV) of more than 100 degrees in a diagonal direction, an F number of more than 2 in a visible spectrum, an effective focal length of more than 2 mm, a total track length of 5 mm, and a back focal length of less than 1 mm.
8 . The image capture device of claim 7 , wherein the controller is configured to:
determine a focus distance for the image capture device;
determine a new profile of the flexible membrane based on the determined focus distance;
determine a control voltage for the at least two thin film piezo actuators to adjust the profile of the flexible membrane to the new profile; and
apply the determined control voltage to the at least two thin film piezo actuators.
9 . The image capture device of claim 7 , wherein the optical lens assembly further comprises:
an aperture stop on a surface of the tunable optical lens facing the first optical lens or the second optical lens.
10 . The image capture device of claim 7 , wherein the optical lens assembly further comprises:
an infrared (IR) blocking coating applied to a surface of the tunable optical lens.
11 . The image capture device of claim 7 , wherein the first optical lens, a third optical lens, a fifth optical lens, and a sixth optical lens within the optical lens assembly have a negative optical power, and the second optical lens and a fourth optical lens within the optical lens assembly have a positive optical power.
12 . A method comprising:
determining, at a controller of an image capture device, a focus distance for the image capture device, wherein the image device comprises:
an optical lens assembly comprising:
a plurality of optical lenses aligned along an orthogonal axis respective of a plane of each of the optical lenses; and
a tunable optical lens positioned between a first optical lens and a second optical lens of the plurality of optical lenses, the tunable optical lens having an adjustable profile, wherein the optical lens assembly has a field of view (FOV) of more than 100 degrees in a diagonal direction, an F number of more than 2 in a visible spectrum, an effective focal length of more than 2 mm, a total track length of 5 mm, and a back focal length of less than 1 mm;
determining a new profile for the tunable optical lens based on the determined focus distance;
determining a control voltage for at least two thin film piezo actuators of the tunable optical lens to adjust the profile of the tunable optical lens to the new profile;
applying the determined control voltage to the at least two thin film piezo actuators; and
capturing an image or a video with the new profile of the tunable optical lens.
13 . The method of claim 12 , further comprising:
reducing flares caused by the tunable optical lens through an aperture stop positioned on a surface of the tunable optical lens facing the first optical lens in the optical lens assembly.
14 . The method of claim 12 , wherein applying the determined control voltage to the at least two thin film piezo actuators comprises:
applying the determined control voltage to adjust a profile of a flexible membrane of the tunable optical lens thereby adjusting a profile of deformable material sandwiched between the flexible membrane and a hard substrate of the tunable optical lens.
15 . The method of claim 12 , further comprising:
filtering infrared (IR) light through an IR blocking coating applied to a surface of a hard substrate of the tunable optical lens.