Patent ID: 8605140

Claim:
Shutter glasses for allowing a user to perceive 3D video comprising: a shutter for a right eye and a shutter for a left eye performing open and close operations of shutters in accordance with a timing signal synchronized with 2D video displayed on a display; a detection unit configured to detect light intensity of linear polarized light from a difference of light intensities of a first light intensity detector and a second light intensity detector; a shutter control unit configured to control the shutter for the right eye and the shutter for the left eye to perform open and close operations of the shutters in accordance with the timing signal based on the difference of light intensities compared to a given threshold; a first polarizing filter having a transmission axis parallel to a polarized direction of linear polarized light emitted from the display; the first light intensity detector being configured for detecting light intensity of light transmitted through the first polarizing filter; a second polarizing filter having a transmission axis vertical to the polarized direction of the linear polarized light emitted from the display; and the second light intensity detector being configured for detecting light intensity of light transmitted through the second polarizing filter, wherein upper portions as well as right and left portions in front of the first polarizing filter and the second polarizing filter are wall surfaces vertical to surfaces of the polarizing filters, and lower portions in front of the first polarizing filter and the second polarizing filter are inclined surfaces inclined downward at a given angle.