Benefits of FreeForm
Rectangular Image
on Rectangular Sensor
Image quality improving inside sensor area, especially at the edges
Using FreeForm optics to increase image quality, across the board, by optimizing an image to better fit a rectangular shape sensor.
Image optimization in line with the rectangular sensor, concentrating image quality where it matters most.
better image quality
reduced image quality
Red denotes image quality (MTF)
Higher intensity depicts to increased image quality
People’s heads at the edges look stretched
People’s heads at the edges look natural
SMIA-TV Distortion
and Waviness Correction
SMIA-TV distortion and waviness correction is needed in many applications to ensure objects appear without wavy artefacts
With FreeForm optics, straight lines stay straight, and the lack of waviness/SMIA-TV distortion allows the entire image to lie within the sensor area
Wavy artefacts due to the full image does not fit in the sensor
Full image fits in the sensor with no wavy artefacts
Wavy artefacts due to the full image does not fit in the sensor
Sensor area
Sensor area
Increased Resolution for Super Wide-Angle Cameras
With FreeForm optics, the image can be “stretched out” to cover a larger sensor area, occupying more pixels on the sensor
The familiar fisheye camera used in surveillance cameras suffers from significant distortion, compressing the image into a circle. This degrades the ability of computer vision to parse highly distorted, lower fidelity information.
As a result, it provides higher resolution of the dewarped image. 33% to 138% more pixels can be used, and this is especially useful where more information in the image us critical.
Alvarez Zoom Lens
Using Alvarez FreeForm lenses to accomplish optical zoom, lenses move perpendicular to the optical axis on a micrometer scale
Continuous Zoom
Discrete Zoom
This is in contrast to lenses in traditional zoom systems that move parallel to the optical axis on a millimeter scale, resulting in a big protruding lens, or using multiple cameras to achieve discrete zoom.
Today’s phones require multiple cameras to achieve “zoom”. This results in a more complex imaging architecture takes up more phone real estate and accomplishes only discrete zoom (currently at 0.5x, 1x, and 2x)
A single Alvarez camera module could replace these multiple cameras, and additionally introduce continuous zoom a superior customer experience. Additionally, Alvarez zoom could be used to achieve much higher zoom factors, e.g. 5x and 10X, and could be paired with a second camera at 1X magnification to deliver a superior zoom experience
Conventional optics
FreeForm optics
The tilted edge lenses need complex mechanical alignment, images from left and right tilted cameras require computer correction
Wide Panoramic Cameras Using Off-axis Systems
Three cameras usage to enable extremely wide fields of view
By introducing FreeForm elements for enhanced specifications in the main camera, and edge lenses with an off-axis design it is possible to obtain a panoramic camera with a wide FOV in a very small form factor with all types of distortion being corrected (keystone, optical, SMIA and others)
No need for computer correction; No loss of resolution due to image correction; Image looks natural
stitched image
stitched image
Targeted Depth of Field
Any regions of the scene or image can be addressed separately during design stage to ensure enhanced image quality or other characteristics
Optimized for long distance
Optimized for short distance
In this automotive example, the regions of interest are far-off traffic lights, cars right in front of and darting pedestrians or cyclists from the edges
FreeForm optics are able to accomplish this targeted performance within a desired area of the image
The vehicle looks as though it is almost aligned with the front wheel of the semi-truck
With a FreeForm lens, the semi-truck look “more natural”, the car on the right, is depicted as its actual distance
Keystone Distortion Correction
Keystone distortion appears when the object is projected on a planar surface under specific angle
It can be efficiently corrected by FreeForm off-axis cameras and provide natural appearance of objects, correct distance estimation, smaller size of industrial machines
A FreeForm, off-axis lens stack has an optical axis that is “bent”, coming in closer to the edge of the phone, directed by the FreeForm lenses eventually onto the middle of the sensor.
This allows the display to be closer to edge of the phone maximizing its size.
Off-axis Design for a Smaller Bezel
Front-facing cameras create a “bezel” – an edge that the display will not “cover” to accommodate light entering the lens stack
To maximum the size of the display, an off-axis camera
(whose optical axis is “shifted” can be used so that the light enters closer to the edge of the phone)
A regular lens stack has an optical axis going through the center of each lens.
This means the display has to be further away from the edge of the phone to accommodate the path of light hitting the sensor.