SU461429A1 - Device for displaying information on the screen of a cathode ray tube - Google Patents

Description

The invention relates to automation and computing and can be used in equipment for visual indication of data from, for example, an electronic computer.

The known devices for displaying information on the screen of a cathode ray tube, containing a memory block connected to a digital-to-analog converter, and an address register, are characterized by low quality of displayed symbols when generated by their functional methods.

The proposed device differs from the known ones in that a code converter and a correction unit are inserted in it, which are connected to the address register and a digital-to-analog converter, and the code converter is connected to the memory unit.

This makes it possible to eliminate oblique distortions of the symbols on the edges of the screen of the cathode ray tube, to improve the quality of the displayed information.

The drawing shows a block diagram of the proposed device.

The device contains a memory block 1, a digital-to-analog converter 2, a code converter 3, a correction block 4, and an address register 5.

2

The device works as follows.

In memory block 1, for example, from electronic

computing machines (computers) are coming

character codes to be displayed on

screen cathode ray tube (CRT). Character codes are accompanied by address codes for screen points at which characters are to be displayed. The address codes come from the computer to the address register 5. Next, the address codes are fed to correction block 4, which produces a signal that changes as a parabolic signal. The function of addresses from the center to the edge of a CRT screen. The digital-to-analog converter 2 from the memory block 1 receives control signals defining single displacements of the beam on the CRT screen in the XY coordinate system. The same signals are sent to code converter 3, where codes of addresses of characters from address register 5 are also supplied. In converter 3, the control signals are converted + d :,

-X, i-j-t /, -y according to the following algorithm:

+

for addresses located

in I and III quadrants + y - - l

-Y + x

for addresses in the II and IV quadrants

1 and

Control signals from the memory unit

from the converter 3, the signals are transferred to various digital-to-analog conversion circuits in converter 2. Moreover, a constant voltage is applied to the digital-to-analog converter of control signals from the memory unit, and a digital-to-analog converter circuit of signals coming from converter 3. as an equivalent

the voltage is the correction signal from the correction unit 4. Then the output signals of these two circuits are summed with their simultaneous integration and arrive at the CRT.

Subject invention

A device for displaying information on the screen of a cathode ray tube, containing a memory block connected to a digital-to-analog converter, and an address register, differing in that, in order to increase the quality of the displayed information, a code converter and a correction block are inserted into it -analogue converter, and the code converter is connected to the memory unit.

$ 8

38ft

NAZL1