Display device, signal processing device, and method for controlling display device

A signal processing device comprising:

• a first IC which performs first processing on an input signal;
• a second IC which performs second processing on the signal processed by the first IC;
• and
• a setting unit which measures a frequency of the input signal and sets a reference frequency inputted to the first IC, based on the measured frequency,
• wherein the first IC is configured to be able to receive the input signal within a frequency range decided by the reference frequency, and
• the setting unit sets the reference frequency such that the frequency range decided by the reference frequency includes the frequency of the input signal, if the frequency of the input signal is out of the frequency range decided by the reference frequency.

A method for controlling a display device, the display device having a first IC which performs first processing on an input image signal and a second IC which performs second processing on the signal processed by the first IC and displaying an image based on the input image signal, the method comprising:

• configuring the first IC to receive the input image signal within a frequency range decided by a reference frequency and perform the first processing;
• measuring a frequency of the input image signal;
• setting the reference frequency inputted to the first IC such that the frequency range decided by the reference frequency includes the frequency of the input image signal, if the frequency of the input image signal is out of the frequency range decided by the reference frequency;
• and
• displaying the image based on the input image signal.