Abstract: The present invention provides a semiconductor integrated circuit for driving a light emitting panel such as an organic EL panel capable of displaying a picture with the optimum picture quality by changing a gray scale voltage and a gamma curve characteristic in accordance with brightness of the environment and specifications of a display used. A semiconductor integrated circuit for display driving is provided with a storing circuit such as a register or a ROM for storing a plurality of values for changing the amplitude of a gray scale voltage, and a storing circuit such as a register or a ROM for storing a plurality of values for changing the gamma curve characteristic. By selecting a value from a plurality of values in the storing circuit in accordance with an output of a photosensor and supplying the selected value to a gray scale voltage generation circuit, the gray scale voltage and the gamma curve characteristic can be dynamically changed.