Hitachi, Ltd.

Akito Takemoto

Michitaka Ohsawa

Yuichiro Kimura

Kazuhiro Kaizaki

Yasuji Noguchi

Kuninori Matsumi

Sadao Kubota

Mitsuo Okimoto

Chiharu Ishino

Kenicji Matsumoto

A plurality of photo detectors are arranged outside the display screen of a projection display apparatus having a built-in digital convergence correction system and a function for adjusting data in the frame memory so as to coincide the photoelectric devices of the photo detectors with the adjustment patterns is provided. The adjusted data when the convergence on the entire screen of the display is adjusted and the adjusted data when the convergence is adjusted by the adjustment function before misconvergence is generated are memorized beforehand. When misconvergence is generated, the convergence is adjusted by the adjustment function again, and a corresponding correction value is obtained on the photo detector by calculating the adjusted data at this time and the prememorized adjusted data, and a correction value on the entire screen is obtained by executing an interpolation calculation from this correction value, and the misconvergence on the entire screen is corrected.

Convergence correction system with recovery function and display

Growing community of inventors

Chigasaki, Japan

Akito Takemoto