Camera modules can be made compact and energy efficient for use not only in digital cameras but also in other devices such as mobile telephones, personal digital assistants (PDAs), and laptop computers. In a mobile telephone, for example, the camera module performs imaging functions, and components such as a keypad, a controller, and a display are used for operation of both telephone functions and imaging functions of the camera module. In particular, the display that provides a visual user interface for telephone configuration or text messaging can show an image from the camera module, and the keypad and controller that are used for making telephone calls can also control and activate the camera module. However, the camera modules in such applications have generally been limited to imaging functions.
A common concern in portable devices, with or without camera modules, is power consumption. Components such as LCD displays or illuminated keypads, for example, consume power when the backlighting is activated. To conserve power and increase the time between required recharging of batteries, many portable systems such as mobile telephones turn off the backlighting after a short period of user inactivity. Additionally, the backlighting level may be under user control to permit use of lower intensity backlighting to conserve power when ambient lighting conditions permit. For example, backlighting for a keypad can be decreased or turned off when the ambient light level is high.
An ongoing goal for portable devices is to increase or improve the functionality of the devices while still providing an adequate operating time before batteries must be recharged.