Problem

Mobile devices must enter a lock/sleep state to reduce power consumption, prevent accidental input, and sometimes to prevent unauthorized input. The device must communicate this clearly, and assist with un-locking.

Solution

When locked or sleeping a Lock Screen or "Sleep Screen" will be displayed, with key information such as events, alerts, time and date, and instructions on how to unlock the device.

Lock screens are useful to prevent input, and power consumption is a real issue, but many lock screens go overboard. Backlight should be minimized or removed, but display drivers left on so retroreflective (ambient light) display is still possible. Pixel-illuminated technologies provide other possibilities.

Variations

Lock screen - right after deliberate lock, or when waking from sleep but not yet unlocked...

Sleep screen - usually no display, but instead do minimal display...

Certain newer technologies, such as OLED, have no backlight. Clever design can illuminate just a few pixels, at low power, and display all relevant Lock Screen information at a very low power level, combining it with a Sleep Screen.

Screens displayed when the device is off but charging, and similar special types of screens, are similar enough to Lock Screens to be considered the same pattern. Display any useful information available to the device. For example, if date and time are stored at a low enough level to be accessed at this point (and they usually are) then display that information, as well as the battery status message.

IS THIS VARIATION OR INTERACTION: Button activations or combinations.

Simple gestures -- may combine (see Galaxy esp... button reveals the lock screen)

Sign On style stuff, especially gestures.

Discuss battery-dead states, or is that not a lock screen???

Interaction Details

May allow response to SMS, and similar. Generalize this.

Unlock methods. Cross with and which-see to signon. Discuss gestural and key-combo unlocks that are not codes.

Presentation Details

Show alerts, time, etc.

Show Annunicator Row generally. Even for battery-dead screens, just show it with all the icons in their off or disabled position, except for an accurate battery meter.

Notes about using screen well, or cross-reference to that display section??? Like N8 clock, etc.

If there's an external output for use with TVs or projectors, don't just send the same signal, but something more suitable to the large display and that moves about so burn in is avoided...

Antipatterns

Mobiles are 24/7, always-on devices for their users. Do not dim the screen and/or cut display by default. Consider the actual power drain, and how else the true needs can be achieved.

Examples