Compact image capture assembly using multiple lenses and image sensors to provide an extended zoom range
View Patent ↗An optical image capture assembly for use in an electronic camera includes a first image sensor for generating a first sensor output; a first lens for forming a first image of the scene on the first image sensor; a second image sensor for generating a second sensor output; and a zoom lens for forming a second image of the scene on the second image sensor. The camera is contained within an enclosure and, in one variation of the assembly, either the first lens or the zoom lens (or both) forms its image through a folded optical system in which an optical path between the lens and its respective image sensor is folded at an angle in order to conserve space within the enclosure.
1. An optical image capture assembly for use in an electronic camera, wherein the camera is contained by an enclosure that includes the optical image capture assembly and provides a front surface through which respective lenses of the optical image capture assembly protrude, said assembly comprising:
a first optical subassembly comprising a first image sensor for generating a first sensor output and a first lens for forming a first image of a scene on the first image sensor;
a second optical subassembly comprising a second image sensor for generating a second sensor output and a zoom lens pointing in the same direction as the first lens and forming a second image of the scene on the second image sensor, wherein the zoom lens is adjustable between a minimum focal length and a maximum focal length to provide the second image, and wherein at least one of the first lens and the zoom lens comprises a folded optical system including an outer objective and relay optics for forming an image through a folded optical path between the outer objective and its respective image sensor in order to conserve space within the enclosure; and
means for supporting the first and second optical subassemblies within the enclosure whereby the first lens and the zoom lens, including the outer objective of the folded optical system, protrude through the front surface of the enclosure and are substantially coplanar with said front surface.
2. The assembly as claimed in claim 1 further including a control section for driving the sensors and for selecting either the first sensor output from the first image sensor or the second sensor output from the second image sensor.
3. The assembly as claimed in claim 1 wherein the first lens has a fixed focal length.
4. The assembly as claimed in claim 1 wherein the first lens is an additional zoom lens.
5. The assembly as claimed in claim 1 further comprising:
at least one additional image sensor for generating a corresponding sensor output; and
at least one additional lens for forming a corresponding image of the scene on the additional image sensor.
6. The assembly as claimed in claim 5 wherein at least one of the additional lenses is a zoom lens.
7. The assembly as claimed in claim 1 wherein the sensors are packaged in a common integrated circuit package.
8. The assembly as claimed in claim 7 wherein the lenses are provided in a common assembly that mounts onto the integrated circuit package.
9. The assembly as claimed in claim 1 wherein both the first lens and the zoom lens form their images through a folded optical system in which an optical path between the lens and its respective image sensor is folded at an angle in order to conserve space within the enclosure.
10. The assembly as claimed in claim 1 wherein at least one of the first lens and the zoom lens is a prism lens.