That sounds a lot like the Cromemco Cyclops. Released in 1975, it used a modified1 MOS 1kbit DRAM2 to capture a 32×32 black and white or greyscale image. The memory cells were initially set to all
1s. As they were exposed to light they would progressively switch to
0s; the more light hitting a cell, the faster the transition4. By making multiple read passes, a greyscale image could be read. The camera was sold with a case, lens, etc. along with controller cards for use in an S-100 bus computer. Given that the system was comprised entirely of off-the-shelf parts (with only one minor modification) and included complete source code it would have been trivial to clone both in the Eastern Bloc and elsewhere.
1 Modified meaning replacing the opaque die cover with a transparent one.
2 The same technique would probably also work fine with higher density non-buffered3 DRAMs.
3 Thanks to Raffzahn for pointing that out.
4 This results in a negative image when it is read out:
0s in the bright areas,
1s in the dark portions.
The image sensor chip:
Source: Wikimedia Commons (Public domain)
Reading through the camera manual it seems the camera itself comprised of a case, lens, and 3 circuit boards. The front board had the image sensor, a sequential address generator for reading out the values, and two bias LEDs used to improve sensitivity in low-light situations. The second board contained support circuitry, and the third board contained the power supply and IO transceiver. Communication with the camera was over a pair of differential lines (one input pair and one output pair).
There is no mention of frame rate in the camera manual, however in the interface manual (see below) there is a mention of a clock signal (1µs per pixel) and initialization time (5µs for regular capture, 17µs for capture with the bias LEDs active); it took as long to reset the memory cells as it did to read a single monochrome frame. Ignoring the setup time, the capture time for a single monochrome frame is 1024µs or ~976 frames per second. For full bit-depth greyscale images the sensor would be read 15 times in 15.36ms resulting in a maximum frame rate of ~65 frames per second (16.39ms or ~61 frames per second including initialization). The interface supported four exposure settings which modified the capture rate5; these resulted in greyscale frame rates of ~61, ~22.5, ~14, and ~10 frames per second. 15 reads per greyscale frame means the final, processed images were probably 4 bits per pixel (24 = 16). I'd have to read the camera and controller schematics and driver code more closely to be sure about any of the above.
The computer interface used a pair of cards that plugged into an i8080-based S-100 bus system. These cards consisted almost entirely of 74-series ICs. Each card set could control up to 16 cameras. DMA was used to transfer images to the controlling system's RAM and an interrupt could be generated for each captured frame. Use of this card set was optional; the camera manual (mentioned above) describes the interface in detail and gives an example of displaying the image directly on an oscilloscope. The sample code provided is for an i8080-based system but I see no reason why the card set couldn't be adapted to S-100 systems using different CPUs.
Both of the above-linked documents include complete schematics, parts lists, and IO protocol descriptions.
5 By adding a delay of 0, 2, 4, or 6 ms between each complete read of the memory (i.e. every 1024 bit reads).