SU503263A1 - Graphic reading device - Google Patents

Description

give short pulses from their outputs (pulse duration 0.7–1.0 me). The zone switching unit 3 generates, from its outputs, zone resolution pulses of a duration of several tens of clock frequency periods (the number of clock frequency periods depends on the device’s size and on how many zones the additional buses are divided). Such pulses cannot be directly applied for polling additional tires, since a pencil is a pencil because of its small capacity — an additional tire selects only the fronts of the pulse. Therefore, the modulation unit 4 is inserted. The zone switching unit 3 determines the time limits of the zone to be selected, and in the modulation unit 4, the clock pulses are modulated by zone resolution pulses. From the outputs of the modulation unit 4, suppressing strobe pulses are received to interrogate additional tires. At the output of the modulation unit 4, the strobe suppressive pulses are absent at those times when the zone resolution pulse is present at the corresponding control input of the modulation unit. In time, the strobe suppressive pulses coincide with the pulses of the pulse distributor, but have a different polarity with respect to them. Since the pulses of the coordinate distributors of pulses 5 and 6 and the suppressive pulses of the strobe of modulation unit 4 have different polarity, then at the time of time when they coincide, they mutually compensate each other, i.e., the impulse distributor pulses suppress. At those times when the strobe pulse suppressors are absent, the pulse distributor pulses are read with a pencil.

The clock frequency generator 13 generates a continuous sequence of frequency pulses in the order of 300 kG. The pulses from the output of the generator 13 are fed to one input of the logical element I 15. There are no pulses at its output, since this element is closed at the second input by a level coming from the single output of cycle trigger 14. The trigger pulse of cycle 14 is set to one state and allows the clock pulses to pass through the AND 15 gate. At the same time, the start pulse sets registers I and 12 to the zero state. From the output of the AND gate 15, the clock frequency pulses go to the count input of the pulse counter owl 7 and to the input of the delay unit 19. Single outputs of the trigger

the pulse counter 7 is prepared on the first input of two groups of three-input gates 9 and 10. In addition, the trigger outputs of the counter 7 are connected to the zone switching unit 3. The most significant bit of the pulse counter 7 controls the second inputs of the groups of three-input gates 9 and 10.

Clock Pulses Delayed

delay circuit 20, is fed to the input of the delay circuit 21 and to the input of the switching unit

zones 3. From the block of switching of zones 3 impulses

enter the modulation unit 4.

The clock pulses that pass through the delay block 19 also go to the first inputs of logic gates AND 16 and 17, which are controlled by the second input to levels coming from the high-level trigger outputs of the pulse counter 7.

During the first half-cycle, the coordinate pulse distributor 5 operates, and during the second half-cycle - the pulse distributor 6.

The selection according to the coordinates of the pulses allocated by the amplifier 18 is performed using the trigger of the high bit of the counter 7.

Claims (2)

1. A device for reading graphic information comprising a tablet made in the form of two systems of mutually perpendicular coordinate buses connected to coordinate coordinates of impulses, connected through the first and second logic elements "And to the valve block, a clock frequency generator connected through the third logic element" And, whose control input is connected to a cycle trigger, with a pulse counter and a delay unit, coordinate registers and a reading element connected through an amplifier to a valve unit, characterized in that, in order to simplify the device, it contains a modulation unit connected to the tablet, a delay unit and through the first and second logical elements with coordinate pulse distributors, and a zone switching unit, connected to a pulse counter, delay and modulation unit. 2. A device according to claim 1, characterized in that the tablet, on each of the coordinates, contains additional tires, each of which is located between two main coordinate tires.