Problem

Displays are the most critical output on modern smartphones, as well as a highly touted feature. Even minor degradations in performance can render the display uncomfortable to use, unreadable, or reduce the perception of the quality of the display.

Automatic light sensors and user controlled display settings are difficult to find, difficult to use, and often cannot be made to yield an appropriate light level without significant user input.

Solution

This pattern focuses on higher quality color displays, with light sensors suitable for use setting automatic brightness. Other display types may use many of the components of the patterns, but may not be able to meet all of them. This also presumes backlit screens; lit-pixel screens such as OLED (and AMOLED) screens may have to modify the technical information to achieve the intended result.

Users must be able to get to display settings easily, preferably without much on-screen interaction, in case the screen is hard to read and they need to adjust it. The primary display setting is brightness (white point). Contrast (black point) and other controls may also be provided, but will not be well understood by the typical user; good median values must be selected by default for all other display adjustments.

Automatic sensors must be calibrated correctly, to take into account they are viewing the user's face, at typical mobile use distances. Do not calibrate on neutral gray at infinity.

The user must be able to make manual adjustments even if an automatic setting is provided, and should be able to provide user input to the automatic settings, and provide user calibrations to the light sensor.

Variations

Manual

Automatic

Automatic with manual over-rides

A learning mode would be a useful fourth variation, using the principles of learning user predictive text, voice or gestural input. The device will monitor user overrides to automatic input and/or accept multiple user calibrations in order to adjust how automatic behaviors work, with the intent of an entirely satisfactory automatic behavior, eventually.

Interaction Details

Ideally, a direct input method should be available, so the user can change brightness without looking at the screen or selecting functions that may be difficult to see if the screen is far too bright, or far too dim. A well-used option is to have an existing function (such as volume or power) make a general settings panel appear, with brightness, volume, synch and power-off/restart functions. Once it appears, volume keys may change the volume, and (for example) the Left and Right keys may change brightness. Other solutions may be more suitable to the specific interface or operating system.

The primary brightness adjustment control is a slider, or similar control with implied analog input. In fact, this will control input in steps based on the software controlling the display backlight. Allow direct numeric input of these values. Interactive methods from the Spinner pattern may be useful here.

The brightness control must allow setting true minimum and maximum output. Mobile devices can be used in complete darkness, where users eyes may be fully adjusted, or bright screens may distract others. Do not select an arbitrary minimum brightness above the adjustment range value of 1.

A simple setting on the brightness control panel must allow enabling and disabling of the automatic brightness control. This may be set from other places as well.

- Function to add user-adjustment to auto-bright; doesn't disable, just changes it for now... ideally, remember this and factor it in over time based on bright sensors - Sensors will continue to be on front; among other things, probably best for checking light where the user us; Calibrate sensors not to neutral gray, but to people's faces at typical distances. Allow users to recalibrate to themselves, and possibly in several environments to learn brightness...

Presentation Details

Whenever room is available in the Annunicator Row, in a Notification Strip or in similar areas where current settings are displayed, the current brightness settings should be displayed. This should indicate automatic or manual, and the level in the conventional scale of measure used on the adjustment panel itself.

Within the brightness panel, it must be very clear when automatic brightness is enabled. When enabled, display the actual brightness selected by the automatic controls in a manner similar to the manual setting.

When adjusting brightness, the screen must reflect the adjustments in real time, so the user can tell how bright they want it. Do not set then commit to change brightness.

It is highly suggested that adjustments be simulated when the brightness panel is displayed. This is so the adjustment panel itself can be seen in all conditions. Set the screen backlight to 100% brightness, with the adjustment panel as a modal Pop-Upwhere the sliders and instructions simulated (via the pixel color) to 50% brightness, with very high contrast, such as white letters and outlines on a black background. The parent window behind the Pop-Up will simulate (with color changes to the pixels themselves or opacity to a black overlay...) the adjusted-to value.

Within the display adjustment panel, present the brightness numerically as well as via any sliders, dials or other graphical presentation. Some users will understand numerical values better, and most users will be able to recall numerical values that work in certain environments, so may be able to adjust to those by memory if automatic systems do not work.

Antipatterns