JPS5619271A - Original reading device - Google Patents

Abstract

PURPOSE:To select and read only the surface region which is necessary for the real time, by displaying the surface region to be selected on the original with the display line in the different color from the picture on the original and in the directions of both the main and secondary scans and then storing and processing the position signal of the display line. CONSTITUTION:The selected surface region of the original is displayed at the upper and left sides of the screen in the specific color such as the red and in L-shaped display lines M and N. The red signal is discriminated after scanning the original surface and then supplied to binary coding circuit 1 to obtain binary signal An of the n-th scanning line. And FF2 is set by signal An to turn output signal Bn into 1 which is then supplied to line memory 3. In this case, memory 3 reads out binary signal Bn-1 of 1-preceding scanning line stored in memory 3 and then supplies it to NAND circuit 4. Signal An is supplied to circuit 4, and FF2 is reset when both signals An and Bn-1 are O. And signal Bn is stored in memory 3. As a result, the position of the tail part is detected for display line M in the main scanning direction to be stored until display line N in the secondary scanning direction ends. Signal An is inverted 6 to be turned into gate signal Vn showing the selected surface of the original along with signal Bn via AND circuit 5.