SU1552205A2 - Device for reading graphical information - Google Patents

Abstract

The invention relates to automation and computing, in particular to devices for reading graphic information and can be used in systems encoding graphic information. The aim of the invention is to improve the speed of the device. This goal is achieved by operative reorganization of the number of measurement cycles adapted to the individual features of the operator, which is provided by new connections of the resolution signal generating unit and its other constructive performance compared to the prototype. 1 il.

Description

The invention relates to automation, in particular to devices for reading graphic information, and is an improvement in the known composition of a companion. N 1035619.

The purpose of the invention is to increase the speed of the device.

The drawing shows a block diagram of the device.

The device contains a (glass) plate 1, piezoelectric plates of linear deformation — emitters 2 mounted on two mutually perpendicular sides of the plate, a piezotransmitter 3 in the form of a sound-conducting rod fitted with a piezoplate, mounted on the free end of the rod, the strobe formation unit 4 pulses, pulse generator 5 (excitation and control), resolution signal generation unit 6, AND unit 7, K-molding unit

time coordinate intervals, including triggers 9. Strobe pulse shaping unit-contains differential amplifier 10, amplitude rectifier 11, and comparator 12. The resolution shaping unit contains the first 13 and second 14 And elements, the first 15 and second 16 triggers, the third 17 and the fourth 18 elements are AND, the third 19 and fourth are 20 triggers, the first 21 and second 22 counters, the shaper 23 pulses, the OR element 24 and the fifth element AND 25 (the coincidence element). The block of elements And contains - elements And 26-28. The drawing also shows the inputs 29-33 of block 6 and the inputs 34 to 36 of block 7.

The device works as follows.

Preliminary, through input 32, a signal is given, which through the element OR 24 sets the triggers 15 and

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20 to the zero state, while blocking the output of the block 6 for generating the permission signal. The generator 5 generates rectangular pulses applied alternately to the emitter 2 corresponding to the coordinates X and Y. Therefore, the signals generated by the generator 5 are called the start pulses X and Y. At the same time, the start pulses X and Y appear in blocks b and 7. Under the influence of these pulses, emitters 2 are excited, and elastic acoustic waves begin to propagate at a constant speed along an axis perpendicular to the corresponding side of the plate. In block 6, the start-pulses overlap the triggers 16 and 19, and the trigger 16 provides alternate erasure of information in the counters 21 and 22 through the elements And 17 and 18, and the trigger 19 allows the recording of information in the pulse counters. Start pulses Y are used as strobe pulses to erase information in the counters.

Suppose that after power is turned on, trigger 16 is not in the cocked state, i.e. at its inverse output is a logical O, and the trigger 19 is in a suspended state. Then the element And 18 unlocked one input and ready to pass through it erase signal (start-pulse Y). If the start-impulse X arrives first at block 6, then the trigger 19 does not change its state, and the trigger 16 is energized and the element 17 is ready for the erase signal to pass through it. Then the start-pulse Y from the input 31 passes through the element 17 and nulls the pulse counter 21. If, after turning on the power, the triggers were in opposite states, after the arrival of the start, the number of pulses in two adjacent

pulse X would zero the counter of 22 pulses. Thus, in one period (measurement cycle) of the pulses of the generator 5, one pulse counter is nullified, and after another (subsequent) measurement cycle, another pulse counter. At the same time, although elements 13 and 14 both appear in the open state via two inputs, information is not recorded in the pulse counter due to the absence of signals at the comparator output (the piezo receiver is not yet on the tablet surface). After two cycles

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measurement cycles and block 6 generates a measurement resolution signal.

At the moment of installation of the piezo receiver on the tablet surface after the next start-up pulse X (we will consider it first after installing the piezo receiver), the trigger 19 is activated if it is in the zero state. Otherwise, the trigger 19 does not change its state, and the trigger 16 is in a state, for example, when its inverse output is a single level (zero state).

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pulse measurements are zeroed, but AND 25 fails due to the inhibitory zero level from the output of trigger 15.

After excitation of the emitters 2 at a time corresponding to the distance of the front of the traveling acoustic wave from the radiator to the point of contact of the piezotransmitter 3 with the plate surface, the piezotransmitter begins to generate an electrical signal representing sinusoidal oscillations with an exponential envelope. The amplified signal of the piezo receiver 3 is converted by the amplitude rectifier 11 into a packet of sinusoidal half-waves with an exponential envelope. Then, the comparator 12 converts the signal of the amplitude rectifier into a series of square pulses fed to blocks 6 and 7.

The operation of unit 6 is to automatically determine the number of measurement cycles necessary for prohibition, during which the signal collector reaches its nominal value and generates a measurement resolution signal. The automatic determination of the number of forbidden measurement cycles occurs by counting the number of pulses formed at the output of the comparator 12 in adjacent measurement cycles from the piezotransmitter signal corresponding to a coordinate, for example, for the X coordinate. During the installation of the piezotransmitter 3, the number of pulses formed in adjacent measurement cycles, will not be the same. The number of pulses at the output of comparator 12 increases from the previous cycle to the next one until stabilization of the amplitude of the piezo receiver signal. When this moment comes, equalize0

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measurement cycles and block 6 generates a measurement resolution signal.

At the time of installation of the piezo receiver on the tablet surface after the next start-up pulse X (we will consider it first after installing the piezo receiver), the trigger 19 is cocked if it is in the zero state. Otherwise, the trigger 19 does not change its state, and the trigger 16 is in a state, for example, when its inverse output is a single level (zero state).

As a result of such switching element And 13 is open for recording information in the counter 21 pulses. The same, the first, start-pulse X excites the emitter 2, corresponding to the coordinate X. At the moment of receiving the acoustic wave by the piezopripe pick, the latter begins to form a signal. At the first instant of time, the impedance of the acoustic contact does not reach its nominal value, and the signal of the piezo receiver, in amplitude, also does not reach its value. As a result, the signal at the output of comparator 12 is a pulse sequence with a small number of pulses. The sequence of impulses goes through the second input of the element I 13 to the first (counting) input counter 21, in the latter a code proportional to the number of pulses from the output of the comparator is recorded. Simultaneously with the operation of the counter 21, the trigger 15 is charged from

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however, the latter does not work due to the difference in codes. Then, block 6 receives the second start-pulse U, which, through element 17, clears the contents of counter 21, preparing it to receive information from the third measurement cycle. Thus, the number of pulses in adjacent measurement cycles is compared, in this case corresponding to the X coordinate. When the acoustic impedance between the piezoelectric capacitor and the tablet surface reaches its nominal value of the number of pulses in adjacent measurement cycles, the element 25 is equalized and triggered, the signal, the transfer is triggered trigger 20 As a result, the elements AND 26-28 become open to the start-pulses X and Y. The next start-pulse Y passes through the third input.

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the first pulse from the output of the comparator 75 of the element And 28 and cocks one of the trigger 12, and from its output begins the action-gerov 9, while forming the front

permits the potential at the third front of the coordinate time interval entry of the E 28 element.

Then the first start-up pulse Y through input 31 returns the trigger 19 to the initial state and simultaneously passes through the element I 18 to the second input of the counter 22 for zeroing. Next, the generator 5 forms the second one. After installing the piezo receiver, the start-pulse X, and the excited acoustic wave forms a signal in the piezo receiver. By that time, the impedance of the acoustic contact has not yet reached its nominal value, however, the piezo receiver signal already has a somewhat larger amplitude. Therefore, the pulse sequence formed by the comparator consists of |

already from a larger number of pulses.

Claims (1)

45 formula invented Simultaneously with the excitation of the acoustic wave from the second start-pulse X, trigger 19 is re-activated, and trigger 16 turns into a single state. Thereafter, the element 14 is open for recording and the pulses of the comparator 12 pass through the element 14 at the first input of the counter 22. Thereafter, Tu, the trailing edge of which is formed at the moment switching of the trigger 9 to the initial state from the first pulse of the sequence of pulses formed at the output comparator 12. The subsequent start-impulse X cocks the other trigger 9, forming the leading front of the coordinate 35 time interval TX, rear the front of which is formed at the moment of arrival of the first pulse generated by the comparator. Thus, at the outputs of these triggers 9, pulses are formed, the duration of which is proportional to the coordinates of a point on the surface of the tablet. 40 50 A device for reading graphic information on auth.St. No. 1035619, characterized in that, with a speed-raising circuit of the device, therein the first and second synchronization inputs of the resolution shaping unit are connected to the corresponding outputs of the pulse generator 55, the setup input, the unit is the installation input of the device, and the control input of the unit connected to one output of the unit of formation of temporary coordinate internals also records a code proportional to the number of pulses from the output of the comparator. The codes recorded in the counters 21 to 22 are compared at the first and second inputs of the coincidence element 25, 0 | Gala Tu, the leading front of which is formed at the moment switching of the trigger 9 to the initial state from the first pulse of a sequence of pulses formed at the output of the comparator 12. A subsequent start-pulse X triggers another trigger 9, forming the leading edge of the coordinate 5 time interval TX, rear the front of which is formed at the moment of arrival of the first pulse generated by the comparator. Thus, at the outputs of these triggers 9, pulses are formed, the duration of which is proportional to the coordinates of a point on the surface of the tablet. 0 A device for reading graphic information on auth.St. No. 1035619, characterized in that, with a speed-raising circuit of the device, therein the first and second synchronization inputs of the resolution shaping unit are connected to the corresponding outputs of the pulse generator, the setup input, the unit is the installation input of the device, and the control input of the unit is connected to one output of the temporal coordinate internals forming unit, wherein the resolution generating unit contains the first ipnr ger, whose single input is the information input of the block, zero input Connected to the output of the OR element, one input of which is the installation input of the block, and the other connected to the output of the pulse shaper, whose input is the control input of the block, the second trigger, the counting input of which is the first synchronization input of the block the third trigger, whose single input connected to the first synchronizing input of the block, and the zero input is the second synchronizing input of the block, the first And element, whose inputs are connected to the information input of the block, with the inverse output of the second trigger ra and with direct output of the third trigger, and the output 0 connected to the counting input of the second counter, the third element And, the inputs of which are connected to the second synchronizing input of the block and the direct output of the second trigger, and the output connected to the zero input of the first counter, the fourth element And, the inputs of which are connected to the second synchronizing input of the block and the inverse output of the second trigger, and the output is connected to the zero input of the second counter, the fifth And element, the inputs of which are connected to the direct output of the first trigger, the outputs of the first and second counters, and the output connected to one entry in the fourth flip-flop, the zero input of which is connected to the output of the OR gate, and a direct output of the fourth flip-flop is the output unit.