Patent ID: 8971366
Filing Date: 2015-03-03
Classification: G06K,H01S,H05B

Abstract:
1. A laser power control killswitch arrangement for regulating output power of a laser beam emitted by a laser in an electro-optical reader, comprising: a laser drive circuit for driving the laser with a drive current having an operating amplitude in an operating condition in which the output power does not exceed a laser safety level, and a fault amplitude in a fault condition in which the output power exceeds the laser safety level, and wherein the fault amplitude is greater than the operating amplitude, but is less than a burnout amplitude of a burnout drive current that causes the laser to burn out; a memory for storing a killswitch byte having a default state in the operating condition, and a kill state in the fault condition; a controller operatively connected to the memory and the laser drive circuit, and operative for energizing the laser drive circuit when the killswitch byte is in the default state in the operating condition, for detecting the fault condition and for responsively changing the killswitch byte to the kill state, and for permanently deenergizing the laser drive circuit and for maintaining the laser drive circuit permanently deenergized after the killswitch byte has been changed to the kill state, thereby insuring that the output power will not exceed the laser safety level despite the ability of the laser to withstand the greater fault amplitude of the drive current without burning out, and wherein said detecting the fault condition comprises detecting whether the fault amplitude of the drive current is greater than the operating amplitude of the drive current; and wherein the controller is operative for checking the state of the killswitch byte after manually actuating a trigger but prior to driving the laser with a normal drive current and for driving the laser with the normal drive current only if the killswitch byte is not set to the kill state.