A graphical user interface system may position and orient a user interface element to be displayed on an optically-sensitive display surface. A male terminal of a male connector, and a female terminal of a female connector are slidable relative to each other when in contact with each other. A plurality of light source groups are coupled with the frame and are each configured to produce one or more wavelengths of light. Therefore, if the confocal optical system is designed so that the focal point differs depending on wavelength, the image at each focal point corresponding to each wavelength can be formed clearly.