Thin dual-aperture zoom digital camera
A dual-aperture zoom camera comprising a Wide camera with a respective Wide lens and a Tele camera with a respective Tele lens, the Wide and Tele cameras mounted directly on a single printed circuit board, wherein the Wide and Tele lenses have respective effective focal lengths EFL W and EFL T and respective total track lengths TTL W and TTL T and wherein TTL W /EFL W >1.1 and TTL T /EFL T <1.0. Optionally, the dual-aperture zoom camera may further comprise an optical OIS controller configured to provide a compensation lens movement according to a user-defined zoom factor (ZF) and a camera tilt (CT) through LMV=CT*EFL ZF , where EFL ZF is a zoom-factor dependent effective focal length.
1 . A camera system, comprising:
a Wide camera that includes a Wide lens with an effective focal length EFL W and a total track length TTL W , wherein the Wide lens satisfies a ratio TTL W /EFL W larger than 1.1;
a Tele camera that includes a Tele lens with an effective focal length EFL T , a total track length TTL T and a F number smaller than 2.9, wherein the Tele lens includes a first lens element facing an object side with a positive refractive power and a second lens element, wherein the Tele lens satisfies a ratio TTL T /EFL T smaller than 1.0, and wherein a center thickness of each lens element in the Tele lens is equal to or larger than 0.2 mm;
a stop positioned at an object side of the second lens element; and
a window positioned between the plurality of refractive lens elements and an image plane.
2 . The camera system of claim 1 , wherein EFL T /EFL W =e, and wherein e is in the range 1.3-2.0.
3 . The camera system of claim 1 , wherein a height difference between the Tele and Wide cameras is equal to or smaller than 1.65 mm.
4 . The camera system of claim 1 , wherein a ratio TTL T /EFL T is smaller than 0.9.
5 . The camera system of claim 1 , wherein the Tele lens includes, in order from the object side to the image plane a first lens group and a second lens group, and wherein an air gap between the first lens group and the second lens group is larger than any other air gap between lens elements.
6 . The camera system of claim 5 , wherein the air gap between the first lens group and the second lens group is larger than 2 times any other air gap between lens elements.
7 . The camera system of claim 5 , wherein the first lens group includes three lens elements and wherein the second lens group includes two lens elements.
8 . The camera system of claim 1 , wherein the Tele camera and the Wide camera are operational to perform optical image stabilization (OIS), and wherein the Wide lens is moved for OIS of the Wide camera, and wherein the Tele lens is moved for OIS of the Tele camera.
9 . The camera system of claim 8 , wherein the movement for OIS of the Wide camera is determined by EFL W , and wherein the movement for OIS of the Tele camera is determined by EFL T .
10 . The camera system of claim 1 , wherein a ratio TTL T /TTL W is in the range 1.0-1.25.
11 . The camera system of claim 1 , wherein a ratio TTL T /TTL W is smaller than 0.8×(EFL T /EFL W ).
12 . The camera system of claim 1 , wherein EFL W is in the range of 2.5 mm-6 mm.
13 . The camera system of claim 1 , wherein EFL T is in the range of 5 mm-12 mm.
14 . The camera system of claim 1 , wherein the camera system has a camera height of equal to or less than 7 mm.
15 . The camera system of claim 1 , wherein the first lens element has a convex object-side surface, and wherein the Tele lens comprises a second lens element with negative refractive power having a thickness d 2 on the optical axis and separated from the first lens element by a first air gap, a third lens element with negative refractive power and separated from the second lens element by a second air gap, a fourth lens element having a positive refractive power and separated from the third lens element by a third air gap, and a fifth lens element having a negative refractive power, separated from the fourth lens element by a fourth air gap, the fifth lens element having a thickness d 5 on the optical axis.
16 . The camera system of claim 15 , wherein the focal length of the first lens element f1 is smaller than TTL T /2, wherein the first, third and fifth lens elements have each an Abbe number greater than 50, wherein the second and fourth lens elements have each an Abbe number smaller than 30, wherein the first air gap is smaller than d 2 /2, and wherein the third air gap is greater than TTL T /5, and wherein the fourth air gap is smaller than 1.5d 5 .
17 . The camera system of claim 1 , wherein the camera system is included in a mobile device.
18 . The camera system of claim 17 , wherein the mobile device is a smartphone.
19 . The camera system of claim 17 , wherein the mobile device is a tablet.