| 摘要 |
Functionality relating to the user interface of a handportable device is controlled in dependence on a comparison of a present circumstance of the device with a threshold level. In a radio telephone, backlighting of a display and of a keypad may be controlled in response to a light detector and/or a battery level detector. The backlights may be disabled if the ambient light level is above a first threshold and may be fully on if the surrounding light level is below a lower second threshold. The backlight level may be inversely proportional to ambient level when the ambient level is between the first and second threshold. Instead of directly measuring ambient light level, it may be estimated according to date, time of day, and location. If dialling is a priority, a display backlight may be disabled when battery level; falls below a first threshold, and a keypad backlight may also be disabled when battery level falls below a lower second threshold. If dialling is not a priority, the display and keypad backlights may be disabled when the battery level falls below the first threshold, and the display may also be turned off when the battery level falls below the second threshold. In an alternative embodiment, the user can set the backlighting to function in a desired manner for different operating environments, such as outdoor, meeting, silent and office, (Fig. 10). |
