| 摘要 |
PURPOSE:To reduce the size and weight and to decrease the offset and drift by providing an optical system with a switch which turns on and off the light output of a coherent light source and providing a signal processing system with a function which detects and corrects a self-offset value. CONSTITUTION:When a command signal E6 is varied to zero in T1 at a period T2, the switch 8 turns on while the signal E6 is 1 and a command value E'p comes to Ep to apply a DC signal E8 to the coherent light source 1, so that the light output of an optical branch device 2a becomes a specific value. While the signal E6 is zero, on the other hand, the switch 8 turns off and the command value E'p becomes zero, so that the light output of the optical branch device 2a becomes zero finally. The output signal E3 of a synchronous detector 9, therefore, comes to have no variation due to an input angular velocity OMEGAin and while the signal E6 is zero, the value is only an electric offset value Ee. This offset value is detected by an arithmetic processing part 11 and stored and the offset value which is stored previously is subtracted from the value of the output E3 while the signal E6 is 1 to find the input angular velocity OMEGAin, so that an error due to the offset in a detected value OMEGAout is corrected. |
