SU739575A1 - Graphical data readout device - Google Patents

Description

The invention relates to the field of automation and computing. A device for reading graphic information 1 is known. It contains a plan, made in the form of a system of two mutually orthogonal coordinate buses, the inputs of which are connected to an analysis and control unit through corresponding switches, and the outputs are connected to a zero-potential bus and are inductively connected. which is connected through the delay element and the pulse shaper with the puller coordinates. A disadvantage of the known device is the complexity of the switching equipment of conductive coordinate buses. The closest in technical essence to the invention is a device comprising a tablet made in the form of a system of two mutually orthogonal coordinate buses, one ends of which are connected to the first switching units, a control unit connected to the coordinate remover, with an amplitude discriminator and the first and second blocks switching 2. However, such a device is difficult. The purpose of the invention is to simplify the device. The goal is achieved by the fact that the proposed device contains a block for generating read-out field sampling signals, the inputs of which are connected to a second switching unit connected to the amplitude discriminator, and the outputs to a coordinate remover and the other forming bus ends The sampling signals of the read field are made in the form of parallel-arranged conductive shells, inductively connected with an additional coordinate remover. The drawing shows a block diagram of the device. The device contains a coordinate remover 1, a tablet 2, a control unit 3, first switching units 4, 5, a reading field 6 sampling unit that contains a node parallel to the co-located busbars 7 and an additional coordinate remover 8, an amplitude discriminator .9 and a second switching unit 10.

The device works as follows.

When installing the coordinate remover at the selected point of the working floor of the tablet and pressing the Start button (not shown), the control unit generates the output of the current pulses fed into the coordinate remover and coordinate remover 8 of the block 6. At the same time, in the area of the location of pullers 1 and 8 form identical electromagnetic fields of different directions. At the same time, the Coordinate busbars are sequentially switched along one of the coordinate axes (for example, along the X axis), for which the corresponding signals from the control unit are sent to the switching unit Bxod. At that, the bus of the node 7 of the block 6, which is the farthest from the puller 8, is turned on, while the remaining buses of the node 7 are disconnected.

Under the action of an electromagnetic field generated by the flow of a current pulse through the inductance of the coordinate remover 1 in the circuit formed by the commutator coordinate bus and in series with it most distant from the additional tire remover 8, an emf of mutual inductance occurs, which is summed up with in this bus from the effect of the current impulse flowing through the inductance of the pick-up of coordinates 8 of the block 6. In this case, the total emf induced in the selected s consistently connected to the coordinate and additional tires, equal to the difference called EMF. Since in this case the indicated coordinate and additional tires function as a summing circuit, the magnitude and sign of the resulting differential EMF depends on the distances at which coordinate remover 1 from the switched coordinate, tire and puller 8 from the switched additional tire are located, respectively.

If the puller 8 is closer to the additional node node 7 furthest from it than the puller of coordinates 1 from the currently switched coordinate busbar1, then the differential emf signal coming to Bxo; t of the amplitude discriminator from the output of block 10 does not change the state of the amplitude discriminator and In the next device operation cycle, the next coordinate plane of the tablet is switched. If, at the moment, the coordinate switched is located closer to the coordinate remover 1 than the most distant additional bus node 7 from the puller 8, then the signal EMF at the output of unit 10 has a different polarity and the amplitude discriminator will generate a signal, .-

739575

to the input of the control unit. By this signal, the alternating switching of the coordinate tires is stopped, and by the number of the found coordinate tire one can roughly judge (higher bits) the location of the coordinate remover 1.

After the number of the found coordinate coordinate has been determined, the remaining buses of the node 7 are alternately switched with the previously found coordinate tire. For this, the control inputs of the switches 4 and 5 receive the corresponding signals from the control unit. This bus switching of node 7 continues until the differential emf signal at the output of block 10 again changes sign, indicating that the coordinate remover 1 is from the previously found coordinate tire at a distance equal to from the puller 8 to the currently connected bus of the node 7. When the signal at the output of the amplitude discriminator disappears, the alternate switching of the buses of the node 7 stops and the number of the found bus is proportional to the distance from the coordinate remover 1 to the previously found coordinate tire. The coordinate code defining the location of the coordinate remover 1 on the tablet is added up from the number of the found coordinate tire (most significant bits) and the number of the found additional 1CYN of node 7 of block b (third bits).

The determination of the other coordinates of the puller 1 is similar.

The introduction of a new unit and new constructive links has significantly simplified the device. Invention Formula

Claims (2)

1. A device for reading graphic information containing a tablet made in the form of a system of two mutually orthogonal coordinate buses, one ends of which are connected to the first switching unit, a control unit connected to the coordinate remover, with an amplitude discriminator and with the first and second switching units, different in order to simplify the device, it contains; and blocking the read field sampling signals, the inputs of which are connected to the second switching unit, are connected to the amplitude dis the criminator, and the outputs are connected to the puller coordinates and with the other ends of the coordinate tires of the tablet. 2. A device according to claim 1, characterized in that the signal generating unit dis. Cretization of the readout field is made in the form of parallel conductive busbars, inductively connected to an additional coordinate remover. Sources of information taken into account in the examination 1. USSR Author's Certificate No. 534771, cl. G 06 KI / 00, 1975. 2. US Patent No. 3992579, cl. 17818, published. 1975 (prototype).