Abstract: The present invention provides a seal ring structure, which comprises a seal ring member. The seal ring member includes a first ring opening on one side and a second ring opening on the other. A periphery of the first ring opening includes a plurality of leak grooves. When the seal ring member and the valve ball squeeze each other, the plurality of leak grooves can reduce the torque required to rotate the valve ball. A leak-groove length of the plurality of leak grooves is smaller than a seal-ring-member length of the seal ring member. The plurality of leak grooves do not penetrate the seal ring member for avoiding leakage of fluid.

Abstract: A panel light frame is revealed. Each of two ends of a second frame strip is inserted between a pressing end surface and a top end surface of a first frame strip. A front edge of the second frame strip is leaning against the pressing end surface of the first frame strip and an outer end surface of the second frame strip is leaning against the top end surface of the first strip. Thus connection end surfaces of the first and the second frame strip are connected to and positioned by each other. Thereby light from light emitting modules is shielded by the connection end surfaces for preventing light leakage. Moreover, the first and the second frame strips are against, supported and positioned by each other and this makes the connection of the frame strips more convenient. The panel light frame has higher practical value.

Abstract: A method for correcting birefringence in a fiber optic coupler comprising measuring the intrinsic birefringent retardation, fast axis orientation and rotation of separate paths through the coupler and adding lumped birefringent elements to the ports of the coupler in a fashion to compensate for the intrinsic birefringence.

Abstract: A flushing device controllable for discharging a desired amount of water after use of a toilet is provided with a cylinder supported within the tank, a piston slidable in the cylinder and divides the inner space thereof into an upper chamber and a lower chamber with variable volumes, on the piston there are provided with through holes for communicating these two chambers, and a flexible baffle member is attached to the bottom surface of the piston and capable of admitting the water to flow from the upper chamber into the lower chamber.