SU742854A1 - Device for converting light signals into time-related train of electric signals - Google Patents

Description

The screen surface is covered with electrically insulating material 6.

The mode of operation of the voltage generator 1 is shown in FIG. 3, where UQ is the operating voltage to determine the shifts of the main signal;

Tox is the amplitude of the voltage pulse i that removes holes from the photodetector

T is the period of operation of the device, shaded boxes are voltage pulses.

; The device works as follows.

i The light flux from the object, passing through the optical system and transformed by the interrupter 2 into a sequence of light pulses, is directed perpendicular to the plane of the device, falls on the free (left uncovered) over: something photosensitive semiconductor layer 3. in diseased places, non-equilibrium carriers (electron-hole pairs) are generated, the density of which, in the case of pulsed exposure, is proportional to the intensity of the OS: the matter at this point, i.e. carrier density replicates the intensity of illumination from an object. Readout of the output signal occurs by pulling the generated carriers of the same sign (for example, electrons) with a constant electric field directed along the axis of the photodetector 3. This field direction is provided by a direct current 1 flowing through the conductive U-shaped screen 5. The electrical circuit of the device is shown in fig. 4. Current Zo flows in a circuit: voltage generator 1 - point b - screen 5 - point 7. The intensity of the electric field must be high enough so that the field is not distorted by the charge of the generated carriers. The movement of the electrodes in the photodetector 3 is shown by dotted arrows in FIG. 1. The extruded carriers pass through the circuit: generator1 is voltage, nor - 1 point 6 - semiconductor layer 3 - differentiating chain 4 point 8 and generates alternating current D (t) in this chain. The time derivative is 6J (t) / d t (i.e., the signal taken from the differentiating chain repeats in time the intensity distribution of the illumination along the length of the photo-receiver.

FIG. 5 shows the time base of the output electrical signal generated by the image of the light letter P.

Claims (1)

Invention Formula A device for converting light signals into a time sequence of electrical signals according to the author. St. No. So that, in order to ensure the transformation of two-dimensional light images, a screen of electrically conductive material is inserted into it, connected to a source of pulsed voltage and covering the vessel and the side surface of a semi-semiconductor photodetector bent in as a raster, with the inner surface of the screen covered with electrically insulating material. ABOUT Fig.Z  tli Icmp2emfJcmp emp Bemp femp ftsg. $