TELE CAMERA OPTICS

Thin Zoom Dual Cameras

high quality standards

Mobile phone lenses are designed to meet high-quality standards across a fairly wide viewing angle (e.g., 25mm focal length equivalent). These lenses (typically a stack of five to seven lens elements housed in a lens barrel) have stringent manufacturing constraints that assure high yield and repeatability in mass production. Such design constraints result in lens designs having a total track length (TTL) that is larger than the effective focal length (EFL) of the lens assembly.
The TTL is the key parameter that determines the height of the camera and the thickness of the phone; thus, minimizing it is of great importance. Let’s consider an example of a wide-angle lens for a commonly found 1/3” image sensor. Such a lens assembly having an EFL of 4.2mm and a wide aperture (e.g., F/1.8) results in a TTL of about 5mm and module height of 5.8mm

COMPACT ZOOM WIDE +
TELE DUAL CAMERA

Considering two adjacent camera modules having similar sensor size and pixel count, the tele camera, having a narrow angle of view (e.g., 50mm for 2x zoom), requires a lens assembly with a much larger EFL satisfying:

EFLτ =2×EFLω×(Pixel Size τ)/(Pixel Size ω)

For EFLw=4.4mm, Pixel_Sizew=1.4um and Pixel_SizeT=1.0um, the tele camera EFL required is 6.3mm. Typical lens designs having such EFL will result in a module height exceeding 8mm. In order to enable zoom dual cameras in a slim form factor, Corephotonics developed and patented a compact narrow-angle telephoto lens in which the TTL would uncommonly be smaller than the EFL. While doing so, we keep the large aperture (up to F/2.2) and minimize the EFL to TTL ratio (down to 0.87) without any compromise in optical quality or manufacturability. The result enables 2x-3x optical zoom cameras with superior low light performance and high resolving power, which complies without breaching module height constraints dictated by smartphone industrial design

Image quality

Image quality testing
UI/UX testing
Testing benchmark design and integration

Camera hardware

Compact Lens design
Micro electro-mechanical systems for zoom, auto-focus, optical image stabilization
Diverse actuator technologies and control systems
Environmental and reliability testing in preparation for ultra high volume Manufacturing

Computer Vision

Deep Computer Vision models for: scene understanding, object detection and recognition and tracking; classification; depth analysis
Stereo vision and depth mapping
Image fusion
Dynamic multi aperture calibration
Heterogeneous computing (MT CPU, GPU, DSP, unified-memory architecture)
Mobile camera software architecture
UI/UX design for camera applications