SU898472A1 - Device for control of graphic information output - Google Patents

Description

I

The invention relates to automation and computing, in particular, to devices for controlling the output of graphic information and computer systems.

A device containing a scanner is known, the inputs of which are connected to a servo unit connected to a switching unit, and the outputs are connected to an analog-digital converter through a photoelectric converters unit, a linear interpolation unit whose inputs are connected to a register and a computer, and the outputs are connected to the unit the synchronization unit, the comparison unit and the motion direction unit, the inputs of which are connected to the synchronization unit, and the outputs are connected to the switching unit, the laser modulation unit and the photometric unit tl.,

A disadvantage of the known device lies in its low speed.

Closest to the present invention is a device comprising a scanning unit connected to photoelectric converters connected to a signal conditioner, a digital-to-analog converter.

connected to a reversible counter and with a drive, a scanning unit, commutators, AND elements, a logic unit and an execution unit 2.

The drawback of the device lies in the low speed limited by the frequency constraints of the elements of the digitization channel of the movement.

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

The goal is achieved by the fact that, in a device containing a scanning unit, the drive of which is connected to a digital-to-analog converter connected to a reversible counter, pulse drivers, whose inputs are connected to corresponding photoelectric converters connected to the scanning unit, and the outputs are connected to differentiating elements and discriminator, the first switch connected to the differentiating elements to the discriminator and to the second switch whose output is connected to the reverse An explicit counter connected to the first element I, introduced a frequency detector connected to a pulse shaper and a second switch, a second element AND connected to a reversible counter, and a third switch, whose inputs are connected to a discriminator, with pulse formers and with a frequency detector , and the outputs are connected. to the first and second, elements. And.

The drawing shows the block diagram of the device.

The device contains a scanning unit 1, the drive 2 of which is connected to a digital-to-analog converter (DAC) 3, a reversible counter 4, first 5 and second 6 switches, discriminator 7 for determining the direction of motion, differentiating elements 8, impulse drivers 9, photoelectric converters 10, frequency detector 11, the third switch 12, the first 13 and the second 14 elements I. The drawing also shows the computer 15.

The device works as follows.

Let the computer 15 receive a command to rotate the mirror of block 1. The code of the magnitude of rotation is entered into the reversible counter 4, the output of the digital-to-analog converter 3 generates a voltage that, through the drive 2, acts on the control windings of block 1 and the mirror starts to rotate. The phase of the sinusoidal signals at the outputs of the photoelectric converters 10 is proportional to the angle of rotation of the mirror. Shaper 9 pulses of sinusoidal signals are converted to meanders, on each front of which differentiating elements 8 form pulses. The total number of pulses that were formed during the period of the sinusoidal signal is four. The direction of movement is determined by the discriminator 7 according to the phase shift between the meanders, which takes two values: +90 and -90 °. When moving in the positive direction, the pulses from the output of the differentiating elements 8 through the first 5 and second b switches arrive at the subtracting input of the reversible counter.4, reducing its contents, while moving in the negative direction, the pulses arrive at the summing input of the reversible counter. Thus, the reversible counter 4 performs the role of a comparison element between the given and the current position of the mirror. When moving, the speed of the mirror can reach a value at which, due to the frequency properties of the element base, malfunctions in the formation and counting of pulses are possible. The achievement of this speed is recorded by the frequency detector 11, which prohibits the passage of pulses from the first switch 5 through the second switch 6 and allows one of the meanders to pass from the output; and the drivers 9 through the third switch 12. Each pulse of the meander corresponds to four counting pulses, therefore through the first 13 or second 14 elements AND (depending on direction of movement) meander pulses applied to the inputs of summing or subtracting the third discharge reversing schetchika.Eto allows, while maintaining the element base, four times to increase the maximum allowable rotation velocity of the mirror scanners. When the speed decreases, frequency detector 11 permits the passage of pulses from the output of differentiating elements 8 through the first 5 and second switches and prevents the square wave from passing through the third switch 12. The operation of the frequency detector 11 is synchronized with one of the edges of the square wave arriving at its input.

Thus, the introduction of new blocks and constructive links allows to increase the maximum speed of rotation of the mirror of the scanning unit by 4 times.

Claims (2)

1..Patent UK No. 1324241, cl. In 6 W, publish.1970. 2. Japan patent 53-33326, cl. 97 (7) In 31, published 1978 (prototype).