ARTIFICIAL HALF-TONE IMAGE DISPLAY DEVICE FOR DISPLAY PANEL

摘要

PURPOSE: To make an artificial half-tone display as to all input signal levels and make a display having no lack of linearity even when the gradation differences of the display panel are not constant. CONSTITUTION: The device which displays an artificial half-tone image on a display panel is provided with a threshold point setting circuit 22 which sets intersections S0-S3 of the straight line connecting the maximum point and minimum point of an input level and respective m-bit (m<=n-1) display levels as threshold points by using the characteristic diagram of the display panel showing the relation of the display levels to an (n)-bit input video signal, and also provided with a comparing circuit 24 which outputs a lower display level (k) between the display levels corresponding to the set threshold points on both the sides of the input video signal; and an artificial half-tone processing circuit 32 adds the display level 1 to the display level (k) at the ratio D1/D2 of the arithmetic values D1 and D2 of an arithmetic circuit 28 to perform artificial half-tone processing. The artificial half-tone processing can be performed as to all the display levels and even if the gradation differences are not constant, the artificial half-tone display can be made without spoiling the linearity.