20 in order to read the image on the original surface 111 therefore it is also unnecessary to provide an optical system such as a lens if a distance between the original surface 111 and the photodetective portion 109 is made larger the reflected light 112 spreads so as to degrade the resolution if the distance between the original surface 111 and the photodetective portion 109 is too small the reflected light 112 will not be incident on the photodetective portion 109 so as to degrade the s n ratio in this example the divergent angle of the incident light 110 is about 90 u00b0 and in order to obtain the resolution of 8 dots mm the thickness of the transparent protective layer 131 is set to be about 100 u03bcm as the result of the experiment the image input output apparatus with the resolution of 8 dots mm could read an image on the screen of 10 inches 1627 u00d7 1219 pixels for 20 seconds i e a rate of 10 u03bcs per pixel in the above example the photodetective portion 109 of the image input section 10 has a lattice like pattern continued over the entire face of the transparent substrate 106 however the pattern of the photodetective portion 109 is not limited to this specific one if the response speed of the liquid crystal is not so high the photodetective portion 109 may be divided into a plurality of blocks so as to take out the outputs of the respective blocks for example as is shown in fig5 the photodetective portion 109 may be divided into two blocks 109 39 and 109 34 so as to take out the outputs v out1 and v.