RU2322767C2 - Pyrovidicon functioning method - Google Patents

Abstract

FIELD: heat vision, in particular, application of pyrovidicons, possible use in devices for observing space.

SUBSTANCE: in accordance to the method, by means of deflection system, scanning pattern is formed, which covers the target of pyrovidicon. Raw scanning of each frame is performed by performing two alternating operations. During first operation, raw-wise reading of heat image signal from the target is performed during direct and reverse movement of beam of identical duration across the whole scanning pattern. During second operation, across whole scanning pattern, raw-wise generation of pedestal charge is performed during direct or reverse movement of beam of identical duration, where electronic beam is defocused and its current is increased up to level, which ensures compensation of charge on current row and adjacent rows, introduced by the beam during reading.

EFFECT: increased image quality, which is achieved due to increased signal to noise ratio and resolution capacity in terms of temperature.

Description

The invention relates to a thermal imaging technique, in particular to the use of pyrovidicones, and can be used in devices for viewing space.

A device for controlling the quality of an optical system [1] is known, which contains a radiation source, a condenser, a modulator, a photometric wedge, a test object installed in the focal plane of the collimator, a controlled optical system, a micro lens, and an image analysis unit containing a pyrocamera with a scan unit, the first output of which is connected in series with the ADC, a control and data processing unit, whose first output is connected with the first input of the synchronization circuit, m the second and third outputs of the pyrocamera are connected respectively to the second inputs of the synchronization circuit and the control and data processing unit, the first and second outputs of the synchronization circuit are connected respectively to the modulator and the second input of the ADC, the third input of which is connected to the second output of the control and data processing unit. The disadvantage of this device is the limited image quality and resolution in temperature, with significant design complexity.

Known thermal imaging camera with a device for controlling the temperature of the pyrovidicon target [2], containing a lens, a shutter, a thermoregulatory element, a pyrovidicon consisting of an entrance window, a pyroelectric target, a scanning electron beam and an electronic searchlight; perhaps the presence of a built-in temperature control element or an external regulator shows the observed object. The disadvantage of the camera is the limited image quality and temperature resolution, with significant design complexity.

The closest in technical essence is the method of operation of the pyrovidicon [3], which consists in creating an electron beam, deflecting the beam and forming a raster, fitting the target into it, adjusting the beam current, reading the signal in the forward direction of the beam line by line from the target and generating a charge pedestal on the reverse beam, the current of the reverse beam is reduced three times and three times the beam is carried out along the read line. In addition, the task can be ensured by the fact that the vertical deflection of the beam is carried out according to a linear-step dependence, and the fact that the beam is driven backward along a line at a constant speed. The disadvantage of this method is the limited image quality and resolution in temperature, with significant design complexity.

The technical result consists in improving the image quality by increasing the signal-to-noise ratio and resolution in temperature, while maintaining the functionality without significantly complicating the design.

The technical result is ensured by creating an electron beam, adjusting the beam current, deflecting the beam and forming a raster covering the target, reading the signal line by line from the target in the forward beam direction and generating a pedestal charge on the backward beam, reading the signal line by line and on the backward beam , the duration of which is equal to the duration of the forward stroke of the beam, during the total duration of the direct moves of the beam of the frame when reading, and the remaining time of the frame is used to generate a row-wise charge of the pedestal flaxly and in the forward path of the beam, and when generating a pedestal charge, the beam current is increased and it is defocused.

The implementation of the functioning of pyrovidicone in accordance with the above method is carried out in the following way. An electron beam is created in a pyroelectric vidicon. Using a deflecting system, a raster is formed covering the pyrovidicone target. The line scan of each frame is carried out by performing two alternating operations. During the first operation, the thermal image signal is read out from the target line by line with the forward and reverse beam paths of the same duration throughout the raster. During the second operation, a pedestal charge is generated line-by-line throughout the raster with the forward and reverse paths of the beam of the same duration, and the electron beam is defocused and its current is increased to a level that ensures compensation of the charge on the current and near lines introduced by the beam during reading. Moreover, for a more uniform deposition of charge, the beam velocity along the line is kept constant. Thus, the separation in time of the operations of reading the signal of the thermal image and generating the charge of the pedestal allows, in comparison with the prototype, to exclude the masking effect of the beam forming the charge of the pedestal during the reverse stroke along the line on the yet unread lines, which provides an increase in image quality due to the increase signal-to-noise ratio and temperature resolution, while maintaining functionality.

The pyrovidicon functioning method can be implemented using standard structural modules and on an accessible element base. The constructive implementation of the elements is determined by their functional purpose and is known or obvious from the prior art in the applicable time and frequency ranges.

Information sources

1. Patent No. 2024000 (RU). Device for quality control of the optical system / A.A. Zaritsky // BI 30.11.1994.

2. Patent No. 2123239 (RU). A thermal imaging camera with a temperature control device for a pyrovidicon target / V.N.Bodrov et al. // BI 10.12.1998.

3. Patent No. 21411172 (RU). The method of operation of pyrovidicone / A.L. Silvestrov // BI 10.11.1999.

Claims (1)

The pyrovidicon functioning method, which consists in creating an electron beam, regulating the beam current, deflecting the beam and forming a raster covering the target, reads the signal line by line from the target line by line with the beam and generates a charge on the back of the beam, characterized in that line by line the signal is also read on the return path, the duration of which is equal to the duration of the forward path of the beam, during the total duration of the forward paths of the beam of the frame during reading, and the remaining frame time is used to generate line by line the charge of the pedestal is additionally also in the forward path of the beam, and when generating the charge of the pedestal, the beam is defocused and the beam current is increased to a level that ensures compensation of the charge on the current and near lines introduced by the beam during reading.