The IP.com Prior Art Database
English (United States)
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Numeric keypad NumLock status management
1. Implementation of Invention Numeric keypads have NumLock On and Off modes in the firmware to be toggled by the NumLock key depression. The NumLock modes of the keypad do not affect NumLock status of the primary keyboard as the keypad is designed not to send the NumLock scan code to the system when the NumLock key is depressed. The keypad has an extra hardware change-over switch to set the initial NumLock mode, which can be synchronized with or reversed against the NumLock status of the primary keyboard. In case of laptop keyboards or space saver keyboards used as a primary keyboard, the initial NumLock mode should be set to the reverse so that the embedded numeric keypad of the primary keyboard is disabled and the external keypad is in the NumLock mode.
2. Key Depression Handling The keypad is to send the NumLock code before and after a keypad key code when the keypad is in the NumLock On mode so that the NumLock status of the primary keyboard is changed only for a sufficiently short period of the keypad key code transmission, and recovered to the original NumLock status. The keypad is to send only a key code when the keypad is in the NumLock Off mode. The initial NumLock mode can be set with an extra hardware change-over switch. The NumLock mode can be changed with a NumLock key depression of the keypad. The NumLock key depression does not send NumLock codes to the system side.
3. Scan Code Output A procedure to send ke...