Apple Invents a Small Form Factor High Resolution Camera, Technology to Speed up Battery Recharging & More
On September 11, 2014, the US Patent & Trademark Office published patent applications from Apple covering technologies related to a new small form factor high-resolution camera, new advancements to speed up battery recharging and more.
Apple Invents a Small Form Factor Spherically Curved High-Resolution Camera
In a nutshell, Apple's invention relates to camera systems, and more specifically to high-resolution, small form factor camera systems.
Generally speaking, Apple notes that with the advent of small mobile multipurpose devices there's a need for a high-resolution small form factor camera. Yet due to limitations of conventional camera technology, conventional small cameras used in today's modern mobile devices usually capture images at lower resolutions and/or with lower image quality than can be achieved with larger, higher quality cameras.
Note that conventional small cameras use planar photosensors, and the image plane formed by the lens system at the photosensor of such cameras follows conventional f*tan(.theta.) image height law. Achieving higher resolution with small package size cameras requires use of a photosensor with very small pixel size (e.g., <1.2 microns) and a very good imaging lens system. However, achievable resolution using conventional lens systems for small cameras has not been sufficient for such small pixels due to factors such as the z-height constraint, limitations on achievable F/number, and manufacturing constraints.
Apple's solution to this problem is their invention that is out to provide a high-resolution camera in a small package size. Specifically, Apple has invented a camera that includes a spherically curved photosensor along with a new lens system.
In at least some embodiments, the effective focal length (f) of the lens system is within about 20% of the radius of curvature (RoC) of the photosensor. The lens system may include in-line lens elements that refract light from an object field to form an image on the concave surface of the photosensor.
In some embodiments, a first lens element refracts light from the object field through a stop to a second lens element, and the second lens element refracts light received from the first lens element to form the image of the object field at the surface of the photosensor.
The image is formed by the lens system at a spherically curved image plane that substantially matches the concave surface of the photosensor. In at least some embodiments, paraxial image height of the image formed on the concave surface of the photosensor by the lens system is substantially equal to f*.theta., where .theta. (theta) is the deflection angle of the lens system. In this way, the lens system is an f*.theta. lens system, and the spherically curved image plane formed by the lens system at the photosensor follows f*.theta. image height law.
Apple's patent FIG. 6 shows us a three-dimensional oblique view of an example spherically curved photosensor #120. Note that the photosensor in this example is shaped like a slice off a hollow sphere. An array of light-capturing pixel elements is located on the inner surface. The outer surface may include connectors, pins, and/or other components for coupling the photosensor to other components within a device such as busses or other ICs.
Apple patent is broken down in distinct chapters covering Example Lens System and Photosensor Parameters, Alternative Embodiments and Distortion Correction.
While the new camera will work with future iDevices, it may also be incorporated into Macs, a future television, Apple TV and no doubt future wearables like a second generation Apple Watch.
One additional twist to this camera lens is that it could be a part of future "projection applications." Whether that's referencing a future pico-like system is unknown at this time.
For camera buffs who want to explore Apple's patent application 20140253677 further, click here.
Apple Invents a Method to Speed up Your Battery Recharging Time
Apple notes that a rechargeable battery in a portable electronic device is often charged using a two-phase process in which the battery is first charged at a constant current and then at a constant voltage. During the constant-current charging phase, the charger may output a charging current to the battery at, for example, a 1 C-rate, where the C-rate is the capacity of the battery divided by one hour. When the output voltage of the charger reaches the maximum charging voltage for the battery, the charger then switches to the constant-voltage charging phase. The charger then charges the battery at the maximum charging voltage until the charging current falls to 10% of the 1 C-rate for the battery, at which point the charging process ends. Theoretically, it will take an hour to finish charging a completely discharged battery at 1 C-rate charging. However, the actual charging process may take from 10% to 30% longer than an hour, with the last few percent of battery capacity during the constant-voltage phase taking disproportionately longer than the same increase in battery capacity during the beginning of the constant-current charging phase. Hence, it is desirable to somehow reduce the time required to charge the last few percent of the battery capacity.
Apple's invention provides the solution to this problem that could one day lead to speedier recharging of your iDevices and MacBooks. More all of the geeky details, see patent application 20140253051 here.
Another Complicated Liquid Metal Invention Surfaces
Most of Apple's liquid metal related patents are complicated and rarely ever provide us with a clear indication of the exact product that the new material will be aimed at or the true benefits that it could one day provide.
For all we know Apple is already using this mystery material and just refuses to publicize that information for competitive reasons.
For those of you that want to check out Apple's latest work on this material, review patent application 20140251568 titled "Methods of Melting and Introducing Amorphous Alloy Feedstock for Casting for Processing."
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