Monitor power management

Abstract

A method of performing power down of a computer monitor when a video signal is no longer present and apparatus which performs the method schedules an automatic power conservation mode after a given period of time unless an inhibiting power sustain command embedded in the video signal is received. The power sustain command is placed in the regular video signal at a regular interval. The frequency of the command may be made shorter than the power-off timeout in order to maintain the power-on state of the monitor. Multiple time lapse thresholds may be set to permit multiple power conservation modes. This method may be implemented without making hardware changes in retrofitting a monitor.

1 . A power management system for managing power usage by a display system, comprising:
 means for receiving a power-sustain command;   a power manager means, connected to a timer such that said power manager means reduces power consumption in said display system unless a power-sustain command is received within a predetermined time period.   
   
   
       2 . The power management system of  claim 1 , wherein the power management system is disposed within a monitor. 
   
   
       3 . The power management system of  claim 1 , wherein the power management system is disposed external to a monitor that is acted upon by the power management system. 
   
   
       4 . The power management system of  claim 1 , wherein the power management system is disposed in a peripheral device external to a monitor which is acted upon by the power management system. 
   
   
       5 - 20 . (canceled) 
   
   
       21 . An apparatus for conserving power in a monitor, comprising:
 means for receiving a video signal which contains a power sustain command;   means for measuring a time the signal does not contain a power sustain command; and means for entering a power management state when the timer exceeds a preset threshold.   
   
   
       22 . The apparatus of  claim 21 , wherein the means for measuring is integrated into the means for receiving. 
   
   
       23 . The apparatus of  claim 21 , wherein the means for measuring is separate from the means for receiving. 
   
   
       24 . The apparatus of  claim 21 , wherein the power management state results in a user-recognizable indication. 
   
   
       25 . The apparatus of  claim 24 , wherein the user-recognizable indication is audible. 
   
   
       26 . The apparatus of  claim 24 , wherein the user-recognizable indication is visual. 
   
   
       27 . The apparatus of  claim 26 , wherein the visual user-recognizable indication includes at least one light emitting diode. 
   
   
       28 . The apparatus of  claim 21 , wherein the apparatus enters an nth power conservation mode if a time lapse measured by the means for measuring reaches or passes an nth threshold, where n is greater than zero. 
   
   
       29 . The apparatus of  claim 21 , wherein the means for receiving complies with a display data channel (DDC) standard. 
   
   
       30 . The apparatus of  claim 21 , wherein the means for measuring includes a watchdog timer. 
   
   
       31 . An apparatus for conserving power in a monitor, comprising:
 an interface for receiving a signal which contains a power sustain command;   a timer for measuring a period of time signal does not contain the power sustain command; and   a display screen for displaying coupled to the interface,   wherein the apparatus enters a power conservation mode if the period of time measured by the timer equals or exceeds a predetermined duration.   
   
   
       32 . The apparatus of  claim 31 , wherein the timer for measuring is integrated into the interface. 
   
   
       33 . The apparatus of  claim 31 , wherein the timer for measuring is separate from the interface. 
   
   
       34 . The apparatus of  claim 33 , wherein the apparatus enters an nth successive power conservation mode if the time measured by the timer reaches or passes an nth time duration threshold, where n is greater than zero. 
   
   
       35 . The apparatus of  claim 31 , wherein the interface and timer are disposed within the monitor.  36 . The apparatus of  claim 31 , wherein the interface and timer are disposed external to the monitor. 
   
   
       36 . The apparatus of  claim 31 , wherein the interface and timer are disposed external to the monitor. 
   
   
       37 . The apparatus of  claim 31 , wherein the apparatus is a computer system. 
   
   
       38 . A computer system, comprising:
 a monitor, the monitor including an interface for receiving a signal which contains a power sustain command, a timer for measuring a period of time signal does not contain the power sustain command, and a display screen for displaying coupled to the interface, the monitor entering a power conservation mode if the period of time measured by the timer equals or exceeds a predetermined duration;
 a processor coupled to the monitor, the processor sending the signal to the monitor; and 
 an input device coupled to the processor for inputting commands and data to the processor. 
   
   
   
       39 . The computer system of  claim 38 , wherein said power conservation mode includes reducing power consumption by shutting off the display screen of said monitor. 
   
   
       40 . The computer system of  claim 39 , wherein said power conservation mode includes reducing power consumption by shutting off a cathode ray tube filament within the monitor. 
   
   
       41 . The computer system of  claim 38 , wherein said power mode includes changing a state of an indicator. 
   
   
       42 . The computer system of  claim 38 , wherein the processor is disposed internal to the monitor. 
   
   
       43 . The computer system of  claim 38 , wherein the monitor has an internal battery backup.