| 摘要 |
PURPOSE:To realize an optional selection for the display of system between an orthogonal coordinates and a polar coordinates, by providing a mechanism that converts the measured prism value of either one of the above-mentioned two coordinates systems into the display of the other coordinates system. CONSTITUTION:The refractive power values PX and PY of X and Y directions are squared through squaring circuits 5 and 6 to be turned into (PX<2>+PY<2>)<1/2> through an adder circuit 7 and a square root circuit 8. This output is equivalent to (r) of the polar coordinates displays (r) and theta. A divider 9 performs an operation of PX/PY and delivers the value of operation to a tan<-1> circuit 10. Figures 13, 14, 17 and 18 indicate the setting circuits to which 0 deg., 180 deg., 360 deg. and 180 deg. are set, respectively. Selecting circuits 12 and 16 perform the selection when the set value is supplied to an adder circuit 11 or a subtractor circuit 15. A selecting circuit 19 selects the output between the circuits 15 and 11. The output of the circuit 19 is equivalent to theta of the polar coordinates display. |
