Image input apparatus for displaying a positionable cursor mark on a reproduced image

An image input apparatus which images an object to display means for reproducing an image of the object on a screen, the image input apparatus comprising:

• shifting means for shifting a mark on said screen in a two-dimensional direction to designate a display position of said mark on said screen;
• determining means for determining a pair of coordinate values Px and Py of corresponding X-Y coordinates of said mark on the screen in accordance with output signals of said shifting means;
• first generator means for generating a first saw tooth wave signal in synchronism with a horizontal synchronizing signal of the video signal;
• second generator means for generating a second saw tooth wave signal in synchronism with a vertical synchronizing signal of the video signal;
• first comparator means for outputting a first coincidence signal when said first saw tooth wave signal coincides with a first voltage level which corresponds to said coordinate value Px;
• second comparator means for outputting a second coincidence signal when said second saw tooth wave signal coincides with a second voltage level which corresponds to said coordinate value Py;
• X-counter means for counting clock pulses of a predetermined frequency after said first coincidence signal is outputted to generate an X-address signal;
• Y-counter means for counting said horizontal synchronizing signal after said second coincidence signal is outputted to generate a Y-address signal;
• memory means having a plurality of memory cells, each for storing dot data of a respective dot of a dot pattern which represents said mark;
• reading means for reading said dot data from said memory cells by sequentially designating a respective one of said memory cells to be read in accordance with said X-address signal and said Y-address signal to generate a secondary video signal;
• and
• mixing means for mixing said secondary video signal with said video signal to display said mark at said designated display position together with the image on said screen.