| 摘要 |
PURPOSE:To obtain a vertical extension device which extends a video signal nonlinearly in a vertical period by a means of digital signal processing mode. CONSTITUTION:Field memory 1 writes a double density video signal, and line memory 2, 3 input adjacent two pieces of picture element data to a mixer 4. A vertical extension setting circuit 5 sets the non-linear vertical extension of the double density video signal. A ROM or RAM 6 outputs geometric distance data between each line in the vertical period as an increment value according to such setting. A cyclic type adder 7 with finite number of bits adds an inputted increment value on the output. Readout from the field memory 1 and write on the line memory 2, 3 are controlled by the most significant bit of data outputted from the adder 7, and the interpolation coefficient of the mixer 4 is controlled by low-order bits except for the most significant bit. |
