Patent ID: 8615037

Claim:
A display apparatus comprising: an image display element configured to be driven based on a digital video signal to display a video; a quantizing part configured to convert an input analog image signal into the digital video signal based on a quantization phase and a quantization frequency; a converting part configured to convert an input value into an output value, the input value being a difference value of signal values of pixels adjacent to each other in the digital video signal; an accumulating part configured to accumulate the output values from the converting part that converts the difference values obtained over entire pixels in one frame of the digital video signal to produce an accumulation evaluation value; and a controller configured to adjust the quantization phase in the quantizing part such that the accumulation evaluation value becomes maximum, wherein, when n represents a number of bits of the digital video signal, a(m) represents the output value from the converting part for the input value m thereto, and m i (i=1, 2, . . . , I−1) represents a boundary value between two sections adjacent to each other among I sections obtained by dividing an entire range 0-2 n −1 of the input value in the converting part, the output values from the converting part for arbitrary ones k1, k2 and k3 of the input values satisfy the following conditions where k1, k2 and k3 have a relationship of k1<m i-1 ≦k2<k3<m i : a ( k 1+1) −a ( k 1) <a ( k 2+1) −a ( k 2) a ( k 2+1) −a ( k 2) =a ( k 3+1) −a ( k 3).