A method for obtaining an image using a radiation projection imaging system including a radiation source and a converter, said converter having a plurality of conversion elements one-dimensionlly or two-dimensionlly arranged and switching elements connected to the respective conversion elements, the method comprising:
- a first step of applying an electric field to the conversion elements for discharging an electric charge from the conversion elements;
- a second step of discharging the electric charge by operating the switching elements after the first step;
- a third step of providing the conversion elements with a negative potential;
- a fourth step of irradiating the converter with radiation from the radiation source after the third step;
- and
- a fifth step of outputting a signal from the converter having image information converted from the radiation.