Patent ID: 8830253

Claim:
A viewing angle controllable display device comprising: an image mixing unit generating a mixed image data signal by mixing an original image data signal, or a gray-adjusted original image data signal, with a protection image data signal that disturbs recognition of the original image; an output image selecting unit receiving both the original image data signal and the mixed image data signal and optionally selecting one of the original image data signal and the mixed image data signal for output to a display panel; and a display panel responding to gate signals sequentially transmitted from a gate driver, and receiving a data voltage corresponding to the original image data signal or the mixed image data signal selected from the output image selecting unit through a data driver, and displaying an original image or a mixed image, the protection image data signal having a gray value modulated within a gray range adjusted based on panel gray data that resides within a memory and used by the display device to indicate an acceptable range of gray values to process.