GB1012445A - - Google Patents

Abstract

1,012,445. Automatic character reading. INTERNATIONAL BUSINESS MACHINES CORPORATION. July 25, 1962 [Aug. 25, 1961], No. 28543/62. Heading G4R. A pen for sensing a character as it is being written comprises a writing tip 24, Figs. 1 and 2, and four light guides 26, 28, 30, 32 surrounding the tip, leading to photo-cells in the body of the pen. The character may be illuminated by small lamps 24a, 24b in the end of the pen or by an external light source. The four photo-cells are shown in Fig. 3 surrounding the ink reservoir 46. When drawing a downward stroke the top photo-cell T responds to the written line emerging from the writing tip; during a right-hand stroke the left photo-cell responds and so on. In diagonal strokes two photo-cells may respond. The four photo-cells are connected via a cable 56 to amplifiers 66-72, Fig. 4. The effect of sensing a character line is to cause the corresponding lead l, r, t, b to increase in voltage. Between lead t are connected a pair of parallel photo-resistors 74, 76 and a neon tube 78. The increase in voltage during a downward stroke causes the tube 78 to fire. The light shines on photo-resistor 76 which decreases in resistance and allows the tube to latch in the fired condition to store the information that a downward stroke has been made. If no further signals arrive the character " 1 " is illuminated by this tube. Light from tube 78 also falls on a photo-resistor 82 to ready the next tube 86 for operation. If the next stroke is to the right, the rignal on lead l fires tube 86. This again latches by light falling on photo-resistor 84. The tube 78 is extinguished by illumination of a shunting photo-resistor 88 and the next stage is readied by light falling on photo-resistor 92. If the next stroke is another downward stroke the signal on lead t now fires tube 90, indicating that a " 4 " may have been written. However, this sequence of strokes is also comprised in a " 5 " and the occurrence of a following left-going stroke fires tube 99 to cancel the " 4 " indication by extinguishing tube 90. The next tube 106 is readied by tube 99 and a final stroke to the right gives a " 5 " indication. In the form of Fig. 5 the pen carries a photo-cell 126 activated by light from a strip source 136 on support 132. During writing the pen moves towards and away from the light source and the signal of the photo-cell fluctuates accordingly. Circuitry (not described) is provided to identify the character from these fluctuations. In the form of Fig. 8 both the light source and the photo-cell are mounted on a support 151, light being reflected from one to the other by a reflective portion of the pen.