Automatic darkening filter with automatic power management

Abstract

A protective automatic darkening filter (ADF) includes automatic power management capabilities. The ADF includes a power management control unit that controls power to the ADF based on whether or not the ADF is currently in use. In one embodiment, to determine whether the ADF is in use, the power management control unit includes a motion sensor that senses movement of the ADF and controls power to the ADF based on the sensed movement.

1 . An automatic darkening filter (ADF), comprising: 
 an ADF helmet;    a switchable filter mounted in the ADF helmet that changes from a light state to a dark state in response to a control signal;    a switchable filter control unit that generates and sends the control signal to the switchable filter in response to information indicative of presence of incident light; and    a power management control unit that senses movement of the ADF and that controls power to the ADF based on the sensed movement.    
   
   
       2 . The ADF of  claim 1 , wherein the power management control unit further includes a motion sensor that senses the movement of the ADF.  
   
   
       3 . The ADF of  claim 2 , wherein the motion sensor detects at least one of motion, acceleration, tilt, shock and vibration.  
   
   
       4 . The ADF of  claim 2 , wherein the motion sensor is positioned within the ADF helmet.  
   
   
       5 . The ADF of  claim 2 , wherein the power management control unit activates the ADF when the sensed movement satisfies a threshold condition.  
   
   
       6 . The ADF of  claim 5 , wherein the threshold condition corresponds to a minimum level of sensed movement that may result from a user activity.  
   
   
       7 . The ADF of  claim 1 , further including a power source coupled to the power management control unit.  
   
   
       8 . The ADF of  claim 7 , wherein the power source comprises a battery.  
   
   
       9 . The ADF of  claim 1 , wherein the power management control unit deactivates the ADF when an OFF condition is satisfied.  
   
   
       10 . The ADF of  claim 9 , wherein the OFF condition includes at least one of absence of a detected welding light for a defined period of time, absence of sensed movement for a defined period of time, and absence of other user activity for a defined period of time.  
   
   
       11 . A method, comprising: 
 sensing movement of an automatic darkening filter; and    controlling power to the automatic darkening filter based on the sensed movement.    
   
   
       12 . The method of  claim 11 , further comprising activating the automatic darkening filter when the sensed movement satisfies a threshold condition.  
   
   
       13 . The method of  claim 11 , further comprising deactivating the automatic darkening filter when an OFF condition is satisfied.  
   
   
       14 . The method of  claim 13 , wherein deactivating the automatic darkening filter when an OFF condition is satisfied further comprises deactivating the automatic darkening filter when the sensed movement indicates absence of movement for a predefined period of time.  
   
   
       15 . The method of  claim 14 , wherein the predefined period of time is within a range of  1  minute to  10  minutes.  
   
   
       16 . The method of  claim 11 , further comprising: 
 sensing a first vibration event when the automatic darkening filter is deactivated;    waiting during a first time frame;    sensing a second vibration event during a second time frame; and    activating the automatic darkening filter in response to the second vibration event.    
   
   
       17 . The method of  claim 16 , wherein the first time frame is within a range of 0.5 seconds to 3 seconds.  
   
   
       18 . The method of  claim 16 , wherein the second time frame is within a range of 0.5 seconds to 3 seconds.  
   
   
       19 . The method of  claim 11 , further comprising: 
 sensing, at time t 0 , a first vibration event when the automatic darkening filter is in a first deactivated state S 0 ;    entering, at time t 1 , a second state S 1 ; and    re-entering, at time t 2 , state S 0  if no vibration event is detected during a time frame t 2 -t 1 .    
   
   
       20 . The method of  claim 17 , wherein the time frame t 2 -t 1  is within a range of 0.5 seconds to 3 seconds.  
   
   
       21 . The method of  claim 17 , wherein a time frame t 1 -t 0  is within a range of 0.5 seconds to 3 seconds.