US Patent 9649753 Wrench with multiple display windows and optical warning method thereof

A wrench with multiple display windows includes a body, two side display window lighting modules and a main display window lighting module. The two side display window lighting modules are illuminated synchronously with each other. The two side display window lighting modules are corresponding to each other. The two side display window lighting modules, are illuminated toward a first optical axis and a second optical axis. The side display window lighting module includes side display window lighting elements configured to generate side display window colors which are turned on or turned off according to the torque. The main display window lighting module is connected to the body and illuminated toward the first optical axis. The main display window lighting module includes main display window lighting elements configured to generate main display window colors which are turned on or turned off according to the torque.