A lock screen is a computer user interface element used by various operating systems. They regulate immediate access to a device by requiring that the user perform a certain action in order to receive access, such as entering a password, using a certain button combination, or performing a certain gesture using a device's touchscreen. While most lock functions on PC operating systems only utilize a login screen, lock screens on mobile devices often provide more functionality beyond unlocking the phone: such as notifications for emails and text messages, a date and time display, or shortcuts to certain applications.
Lock screens by platform
Mobile operating systems
Mobile operating system that run on smartphones and tablets typically use a gesture based lock-screen. Phones manufactured by Neonode were unlocked by swiping to the right on its touchscreen. Apple's iOS, used by the iPhone and iPad lines, utilized a similar unlock mechanism until iOS 10, with an on-screen slider slid to the right. Beginning on iOS 5, sliding in the other direction sends the user directly to the camera app. On iOS 7, the slider widget was removed as part of a larger overhaul of the iOS interface, and users could now swipe from any point of the screen. The lock screen also displays a clock, notifications, and provides audio playback controls. iOS 10 made major changes to the lock screen by removing the swiping gesture for accessing the home screen (requiring a touch of the home button). Swiping is still used to access the camera, as well as an additional page to the left with widgets. The iPhone X uses a swipe up gesture to access the home screen once authenticated, as it does not have a physical home button.
At first, Android did not use a gesture-based lock screen, electing to require the user to press the phone's Menu button. On Android 2.0, a new gesture-based lock screen was introduced, displaying two icons: one for unlocking the phone, and one for setting the volume mode, activated by dragging the relevant icon to the center of the screen on a curve (similarly to a rotary dial). On Android 2.1, the rotary dial was replaced by two tabs on either end of the screen. Android 3.0 introduced a new design: a ball with a padlock icon is dragged to the outside of a circular area. On 4.0, the option to unlock straight to the camera is provided, while 4.1 adds the ability to unlock into a Google Search screen by dragging up. Android 4.2 makes additional changes to the lock screen, allowing users to add widgets to pages accessible on the lock screen by swiping from the left edge of the screen. The camera is accessed in a similar manner by swiping from the right edge of the screen. Android also allows devices to be locked using a password, passcode, a pattern on a grid of 9 circles, fingerprint sensing, or with facial recognition.
Android distributions by other manufacturers typically use different lock screen designs than what stock Android utilizes; newer versions of HTC's Sense used a metallic ring dragged from the bottom of the screen to unlock the phone, and also allows users to launch apps by dragging their respective shortcut icon into the ring instead. On recent Samsung devices, the lock screen involves dragging in any direction from any location on the screen (with TouchWiz Nature devices, such as the Galaxy S III and S4, it is also accompanied by a visual effect such as a pond ripple or lens flare); similarly to HTC's lock screen, app shortcuts can be dragged up from the bottom of the screen to unlock directly into them.
Some apps may contain adware which hijacks the default lock screen to replace it with one that displays advertising. In November 2017, Google Play Store officially banned non-lock screen apps from monetizing the lock screen.
PC operating systems
Windows NT has offered the ability for users to "lock" their computers by displaying a login window, which requires that the active user's password be entered to re-gain access to the system. Since Windows XP, the lock function has also been bound to the keyboard shortcut ⊞ Win+L. On Windows 8, the lock screen was re-designed to closer resemble those used by mobile operating systems; users can choose a distinct wallpaper for use on the lock screen, which now also displays a clock, calendar events, and notifications from other apps. The screen can be dragged upwards with a mouse or touchscreen to unlock the device. Windows 10 maintains this design, whilst adding the ability to use the Cortana voice assistant from the lock screen, and support for slide shows and the "Windows Spotlight" service to retrieve daily wallpapers and optionally receive promotional suggestions related to the wallpaper.
Apple holds several patents related to the sliding lock screen used by its iOS devices: it was granted U.S. Patent 7,657,849 in 2010, and U.S. Patent 8,046,721 in 2011, describing a system that involves continuously dragging an image to a certain point to unlock the device. As part of ongoing patent wars between numerous companies surrounding patents related to mobile devices, Apple asserted these patents in several patent infringement lawsuits outside the United States with competing vendors.
Apple's lawsuits with Samsung in the Netherlands and HTC in the United Kingdom both led to failure: both courts ruled the patents to be invalid, citing the similar lock screen on the N1, a mobile phone manufactured by the Swedish company Neonode, as prior art for Apple's design. The British court specifically ruled that Apple's lock screen was an "obvious improvement" over that of the Neonode N1 due to its additional visual feedback through an on-screen slider graphic (unlike the N1, which only displayed a written instruction explaining the gesture). Early work on touchscreen technology from the University of Maryland Human – Computer Interaction Lab was also cited as prior art, in particular a 1991 touchscreen slider developed by Catherine Plaisant
In January 2012, Apple won a permanent injunction from a German court after it ruled that Motorola Mobility violated the patents on some of its recent devices (although the Motorola Xoom tablet was ruled not to have infringed on the patent). However, Apple was warned that they would have been required to put up a bond as insurance if they were to allow the injunction to take effect, and any potential sales ban as a result would be limited to Germany.
- "The 5 best features in Apple's iOS 5". PC World. Retrieved 13 February 2013.
- "Get to know iOS 7: Design changes". MacWorld. Retrieved 4 December 2013.
- "How to use the Lock screen in iOS 10". TechRadar. Retrieved 2017-11-13.
- "How to use the iPhone's new, confusing lock screen". CNET. Retrieved 2017-11-13.
- Pierce, David. "iPhone X Review: All Up In Your Face ID". Wired. Retrieved 2017-11-13.
- "Android: A visual history". The Verge. Retrieved 14 February 2013.
- "Ars reviews the Motorola Xoom". Ars Technica. Retrieved 14 February 2013.
- "Android 4.0 ICS demo: Active voice dictation, Unlock to camera, and more". SlashGear. Retrieved 14 February 2013.
- "Android 4.1 and Android 4.2 combine to make the ultimate Jelly Bean". TechRadar. Retrieved 14 February 2013.
- "HTC Desire X review: Needs and wants". GSM Arena. Retrieved 14 February 2013.
- "Samsung Galaxy S III Android 4.2.2 firmware leaked, reveals some Galaxy S4 software features". NDTV. Retrieved 18 June 2013.
- "Samsung I8190 Galaxy S III mini review: The Halfling". GSM Arena. Retrieved 14 February 2013.
- "Google bans Android developers from adding lock screen ads". Ars Technica. Retrieved 2017-12-01.
- "How to Quickly Lock Your Computer and Use Other Windows Logo Shortcut Keys". Microsoft. Retrieved 13 February 2013.
- "Windows 8 Feature Focus: Lock Screen". SuperSite for Windows. Retrieved 14 February 2013.
- "How to Use and Tweak Your Windows 10 Lock Screen". PCMAG. Retrieved 2018-11-13.
- "Microsoft wants to put ads on the Windows 10 lock screen". The Verge. Retrieved 2018-11-13.
- Zawinski, Jamie. "XScreenSaver FAQ". Retrieved 13 February 2013.
- "GNOME screen lock ineffective in openSUSE Linux - Update". The H. Retrieved 13 February 2013.
- "Apple Awarded Second Slide-to-Unlock Patent, Targeting HTC?". PC Magazine. Retrieved 14 February 2013.
- "How Patent Battles Threaten the Simple Act of Unlocking a Phone". Wired. Retrieved 14 February 2013.
- "HTC defeats Apple in swipe-to-unlock patent dispute". BBC News. Retrieved 14 February 2013.
- "Apple touch-screen patent war comes to the UK". Retrieved 3 December 2015.
- "1991 video of the HCIL touchscreen toggle switches (University of Maryland)". Retrieved 3 December 2015.
- "Apple slides and blocks Motorola devices over slide-to-unlock". CNET. Retrieved 14 February 2013.
|Wikimedia Commons has media related to lock screens.|