SU853636A1

SU853636A1 - Device for reading graphic data

Info

Publication number: SU853636A1
Application number: SU792853630A
Authority: SU
Inventors: Алексей Васильевич Запалатовский
Original assignee: Ленинградский Ордена Ленина Электро-Технический Институт Им. B.И.Ульянова(Ленина)
Priority date: 1979-12-17
Filing date: 1979-12-17
Publication date: 1981-08-07

Description

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Изобретение относитс к области автоматики, в частности к устройствам дл считывани графической информации , и может быть использовано при пофрагментной автоматической передаче и обработке графических изображений.The invention relates to the field of automation, in particular to devices for reading graphic information, and can be used in fragmentary automatic transfer and processing of graphic images.

Известно устройство дл считывани графической информации 1, содержащее генератор разверток, отклон ющую систему, электроннолучевую трубку , объектив, носитель изображени и последовательно соединенные фотоприемник , видеоусилитель, буферный усилитель, первую линию задержки и анализирующую схему, выход которой подключен к первому входу компаратора . Отводы первой линии задержки подключены к сумматору. Выход сумматора подключен к транзисторному смесителю, второй вход которого подключен к среднему отводу первой линии задержки, а выход через вторую линию задержки - к второму входу компаратора .A device for reading graphic information 1 is known, comprising a sweep generator, a deflecting system, a cathode ray tube, a lens, an image carrier and a series-connected photoreceiver, a video amplifier, a buffer amplifier, a first delay line, and an analysis circuit whose output is connected to the first comparator input. The taps of the first delay line are connected to the adder. The output of the adder is connected to the transistor mixer, the second input of which is connected to the middle tap of the first delay line, and the output through the second delay line to the second input of the comparator.

Наиболее близким к изобретению вл етс устройство, содержащее ЭЛТ, соединенную с блоком разверток и оптически св занную с фокусирующим элементом, фотоприемник, подключенный к блоку усилени , выход которо- . го соединен с компаратором 12.Closest to the invention is a device comprising a CRT connected to a scanner unit and optically coupled to a focusing element, a photodetector connected to a gain unit, the output of which is. go connected to comparator 12.

Его недостаток заключаетс в невысокой надежности устройства.Its disadvantage lies in the low reliability of the device.

Цель изобретени состоит в повышении надежности устройства.The purpose of the invention is to improve the reliability of the device.

Поставленна цель достигаетс тем, что в устройство, содержащее ЭЛТ, соединенную с генератором разверток и оптически св занную с фокусирующим элементом,блок усилени подключенный к фотоприемнику и к компаратору,введены последовательно соединенные пико-i вый детектор, вход которого подк.шочен к блоку усилени , первый повторитель, ключ, подключенный к емкостному элементу , второй повторитель и регу-, лирующий элемент, выход которого к компаратору, соединенному с выходом устройства.The goal is achieved by the fact that a gain unit connected to a photodetector and a comparator is connected in series to a device containing a CRT, connected optically to a focusing element and connected to a comparator, a pico-i detector connected in series, the input of which is connected to the gain unit , the first repeater, the key connected to the capacitive element, the second repeater and regulating element, the output of which is to the comparator connected to the output of the device.

На чертеже представлена структ рна схема устройства. The drawing shows the structural scheme of the device.

Claims

The device includes a scan generator 1, a CRT 2, a focusing element 3, a photodetector 4, a gain unit 5 / containing a video amplifier 6 and a buffer amplifier 7, a peak detector 8, with a reset element 9, a first repeater 10, a capacitor 30. the second repeater 12, the regulating element 13, made in the form of a potentiometer, a comparator 14 and a key 15. The drawing also shows the information carrier .16. The device works as follows. The sweep generator 1 provides the deflection of the electron beam in tpy6Ke 2. The light spot from the screen of the tube 2 is projected by lens 3 into the image plane. The reflected light is collected by the photodetector 4, converted into a video signal, amplified by amplifiers 6 and 7, and compared in the comparator 14 with a threshold level. Image reading is carried out in fragments, i.e. the image field is divided into sections-fragments of a rectangular forsh and the reading of each next fragment begins at the end of the reading of the previous neighboring fragment. By the end of the reading of the next fragment of the image or at the output of the peak detector, a voltage is formed equal to the maximum value of the video signal on this fragment, corresponding to the white level in the readable part of the image (the white level is the voltage of the video signal when reading the bright background of the graphic image). At this moment, the switch 15 closes, the voltage on the capacitor 11 is set equal to the output voltage of the peak detector, after which the switch 15 opens. Element 9 and the discharge capacitor of the peak detector are then closed, preparing it for reading the next fragment. The voltage on the capacitor 11 is stored during the reading of the next adjacent fragment and ensures that the threshold voltage for the comparator is formed. Potentiometer 13 sets the relative position of the threshold level in the video signal. The amount of white in the video signal is not the same in different parts of the image due to the angular non-uniformity of the transparency of the lens and the unequal conditions of removal of reflected light by the photoreceiver. The threshold level when reading a fragment of the image is proportional to the white level of the neighboring fragment, which compensates for the unevenness of the television sensor when quantizing the video signal. The introduction of new assemblies and units, as well as new constructive connections, has significantly improved the reliability of the device. Claims A device for reading graphic information comprising a cathode tube connected to a sweep generator and optically coupled to a focusing element, an amplification block connected to a photodetector and to a comparator, in order to increase the reliability of the device contains a series-connected peak detector, the input of which is connected to the gain unit, the first repeater, the key connected to the capacitive element, the second repeater and the regulating element, the output to orogo connected to a comparator connected to the output of the apparatus. Sources of information taken into account in the examination 1. UK Patent 1032902, cl. G 4 R, publ. .

2. Japanese Patent 49-19619, cl. 97 (7) B 62, published 1974. (prototype).