Palm, Incorporated

Ken Kelly

Van Winston Oler

David Mai

A circuit and method for automatically compensating display contrast for temperature changes allowing user preference setting. The invention can be applied to any device having a display, but in one embodiment, portable electronic devices such as palmtops, other portable computers, personal digital assistants, cellular telephones, portable web browsers, remote controls, pagers, etc. are described herein. The invention allows a user to set a desired contrast preference and provides display feedback to the user as the preference setting is being made. Once the preference is set, the invention automatically compensates the contrast adjustment based on variable temperature conditions to maintain the display according to the user preference. For instance, as the temperature falls, the invention automatically detects this and adjusts the contrast in a first direction to maintain the user preference. Alternatively, as the temperature rises, the invention automatically adjusts contrast in a second direction to maintain the user preference.

Circuit and method for temperature compensated contrast

A system for controlling battery charging. The system comprises a battery charging device, a temperature sensor, and a controller. The battery may be a Lithium polymer battery, or the like. The temperature sensor senses the battery temperature and outputs a temperature data signal. The controller inputs the temperature data signal and determines if the temperature data is outside of a range with an upper limit and lower limit. If so, the controller disables the battery charging circuit, wherein the battery is prevented from being charged. In this fashion, the battery's lifetime (e.g., number of charge/discharge cycles) is extended. In another embodiment, the system further comprises a display. The controller outputs a signal to the display, directing it to display a message indicating that the battery is not being charged because the temperature is out of the pre-determined range.

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Carnation, WA, United States of America

Ken Kelly