There are many, many clues about future products in Apple's patent portfolio. Here, we explore them to see what we can uncover about unreleased products like the iWatchiPhone 6 and iOS 8. What is Apple working on behind the scenes?

Apple is famously secretive, but like all companies it has to issue a list of patents to the USPTO (United States Patent & Trademark Office) and these provide hints at future and upcoming projects. 

Apple is also famous for its patents, they are detailed but often try to disguise product plans in detailed technicality. There are also a lot of patents created to protect Apple’s design, including ones for rounded corners, rectangular products, square icons and double-tapping the screen. These are mostly part of Apple’s ongoing battle with Samsung to stop it from copying its products.

However many Apple patents outline fascinating technologies that the company is working on or is interested in, and show the direction its products could take in the future. 

Here are some key Apple patents that give an insight into the kinds of technology Apple is hoping to use in its future products. You also can follow the links below to go to the patents that relate to the particular product you're looking for.

What Apple patents say about iPhone 6

What Apple patents say about iPad 6

What Apple patents say about iOS 8

What Apple patents say about iWatch

What Apple patents say about new Macs

What Apple patents say about Apple television

What Apple patents say about Apple accessories

What Apple patents say about future tech

What Apple patents say about iPhone 6

Many of Apple's patents could be applied to future versions of its iPhone. Here are just a few of them.

Curved display

After lots of speculation about the display of the iPhone 6, including the suggestion that the next iPhone will have a bigger, curved screen, an Apple patent has been awarded to Apple for the method of manufacturing curved touchscreens.

Apple's "Curved touch sensor" patent describes a method of forming a curved touch surface, that could be used in future iOS devices.

Your face is your password

In December, USPTO awarded Apple a patent relating to a "personal computing device control using face detection and recognition."

With the iPhone 5s, you can unlock the device using just your fingerprint thanks to the Touch ID sensor, but with this patent, future iPhones could be unlocked using facial recognition. So effectively, your face could soon become your password.

Advanced Touch ID fingerprint sensor

A mammoth 612-page patent application filed by Apple in May and published by the World Intellectual Property Organisation in November reveals that Apple is investigating further uses for its fingerprint sensing technology.

The Touch ID, introduced with the iPhone 5s, is just the beginning of what Apple could use the technology for. Keeping the sensor beneath the Home button but adding further functionality is one of the features Apple mentions in the patent. For example, Apple could introduce gestures to the Touch ID Home button. 

Touch ID display

Apple’s iPhone 5S finger scanner is big news at the moment. But back in Jan 2013 Apple issued Patent 20130181949 that outlined a method for including the finger scanner into a display.

Scan display

This technology means that you could place your finger on the display to scan it, instead of the Home Button. We’re not sure if this technology was an original variation to the Home Button scanner found on the iPhone 5S, or if it’ll be combined with the Haptics & Tactile technology to remove the Home Button on a future iPhone and replace it with a virtual on-screen button.

The patent describes a touchscreen display with a fingerprint sensing layer that could be used to introduce advanced multi-user support.

For example, Apple could use the fingerprint sensing display to only allow particular users to open certain apps. This could be useful for those with children who like to explore the iPad, for example.

Additionally, Apple could take the display even further. It could be used in conjunction with a piano app, for example, to teach users the correct finger placement for the instrument.

Attack detection mode

In March, USPTO published an Apple patent filing that could be used to protect iPhone owners when they're in distress.

The patent, titled "Mobile emergency attack and failsafe detection", describes a feature that combines software and hardware to create an emergency services request system that's build in to a smartphone such as the iPhone.

Using the iPhone's sensors, the software could detect when the user is in an emergency situation such as a physical attack or car crash and automatically call for help. Users can set a predefined set of contact numbers, or use the iPhone's automatic service to call local 999 numbers. It can also make use of the GPS to detect the location of the user and call the contact that's closest.

To avoid an abundance of 999 calls being placed unnecessarily, the service has a number of modes and measures in place, such as audible timers to alert the user that a call is about to be made.

Greater touch accuracy

Apple has been awarded a patent that could help prevent accidental touch input from iPhone users on the move.

The patent describes a "variable device graphical user interface" that adapts to movement using sensors that detect patterns of motion. This could make it possible to use an iPhone while running or jogging, for example.

NFC

In 2013, USPTO published an Apple patent covering Near Field Communication (NFC) technology. The patent covers a range of features including a new focus on methods and systems for establishing an NFC session with an electronic device. NFC is a set of short-range wireless standards that let mobile phones communicate with each other – or with other electronic devices.

Apple has filed for multiple NFC-related patents in the past, including a patent application that details an iWallet transaction app, which would allow fast mobile payments.

See also: Apple granted NFC shopping list patent for future iPhones

Sapphire

Apple has several patents that relate to the use of sapphire in iPhones, iPads and other products.

In January 2014, USPTO published a patent titled 'Attachment techniques,' which details methods of fastening sapphire to a device. Sapphire is already used for Apple's camera lens cover, but reports, and additional Apple patents, suggest the company could use the material for future displays, too. 

iPhone camera patents

Lots of Apple's iPhone patents relate to the smartphone's camera. 

3D photographs

iPhones could soon be able to capture images that appear to be 3D. An Apple patent published in December describes a method of capturing stereoscopic image data, which can be used make a photograph appear to have depth. Future iPhones could be capable of selecting two suitable photos and combining them to create a stereoscopic image, which replicates the way humans perceive depth to create a 3D illusion.

Interchangeable camera lenses

Apple is also investigating the possibility of making interchangeable iPhone camera lenses.

In January 2014, the company was issued two patents that describe methods of attaching lenses and camera modules to devices such as the iPhone and iPad.

The first patent, titled "Back panel for a portable electronic device with different camera lens options" does pretty much what it says on the tin. It describes a portable electronic device, namely an iPhone, that has a removable case that would allow camera attachments such as wide-angle or fisheye.

The second patent, titled "Magnetic add-on lenses with alignment ridge," offers an alternative method of attaching new camera lenses to the iPhone using magnets.

Refocusable photographs

A patent published by the USPTO in November reveals that Apple is interested in technology that will allow users to refocus a photograph after it's been taken. Such technology is already used in the Lytro camera, with which you can take a photograph and later choose how you want that photo to be focused.

However, Apple's patent describes a way to make the Lytro (which is a rather large device) fit within an iPhone. This is likely to be a tricky feat, so it's likely that such technology won't be included in Apple's next iPhone, but perhaps in a few years time we'll all have refocusable images in our Camera Roll.

Thinner camera means thinner iPhone

A patent application titled "Electronic device with two image sensors" describes a camera that uses two sensors, one to capture brightness data and the other to capture colour information, which would then be combined to create the photograph.

Why would Apple want to make a camera that has two sensors? The answer is that splitting the two sensors up can enable Apple to make an iPhone that's significantly thinner, in addition to improving image quality.

Plus, while this doesn’t seem as quirky as some of the other patents, the news that Apple is working on a GRIN camera for the iPhone means that it’ll be able to create much thinner devices with better cameras. The camera is one of the key items that determines the width of the iPhone, and is the reason why the camera on the iPhone is typically better than the one on the thinner iPod touch.

Thinner cameras mean thinner devices, and one of Apple's patents outlines a camera system using the Super Advanced Gradient Refractive Index Optics (GRIN). The cutely named GRIN camera bends light before it hits the camera lens, so the lens can be much thinner.

Continue onto page 2 to find out what Apple's patents say about future iPads and iOS 8.

You can also follow these links to find out about other Apple patents:

What Apple patents say about iPad 6

What Apple patents say about iOS 8

What Apple patents say about iWatch

What Apple patents say about new Macs

What Apple patents say about Apple television

What Apple patents say about Apple accessories

What Apple patents say about future tech

The Complete Guide to the iPhone 5s & 5c is on-sale now. Click here for buying information.