Optical switching device and image display device

A method of controlling an optical switching device, said optical switching device comprising:

• a light guide including a total reflection plane capable of totally reflecting input light thereby transmitting the light;
• at least one switching part being in contact at a first position with the total reflection plane of said light guide, said switching part serving to extract evanescent light leaking through the total reflection plane, said switching part being capable of moving to a second position apart from said first position;
• a supporting member for elastically supporting said switching part;
• and electrostatic driving means including at least one pair of electrodes for driving said switching part,
• wherein at least one of said electrodes is divided into a first part and a second part which are symmetric in shape to each other about the center of gravitation of said switching part,
• said method comprising the step of supplying electric power to said first and second parts in such a manner that the timing of supplying the electric power is different between said first and second parts or voltages supplied to said first and second parts are different from each other.