How electronic price tag works?

The left hand side of the board in the 2nd to last picture contains two PIFAs (Planar inverted F antenna). Looks like one is 2.4 GHz and one is 5 GHz.

It appears that the ZBS242 chip is a Samsung SOC with a built in IEEE 802.15.4 ZigBee radio. I can't find much information about it, and the pages I have found are in Korean. Figures.

http://eplus.co.kr/02_pro/sub03_04.php

http://www.kashi.or.kr/upload_files/com/%EC%A7%80%EA%B7%B8%EB%B9%84-%ED%94%84%EB%A1%9C%EC%8B%9C%EB%94%A9-%EC%B5%9C%EC%A2%85.pdf

Edit: now that the PDF I linked finally decided to load, it looks like the ZBS242 is intended for use in RF remote controls. There isn't much information, but it says that it will support an 11x11 keyboard, deep sleep, and a few peripherals. The image in the PDF had a part number ZBS240, which led me to some documentation for a development board with this chip. However, it seems that there is very little information available on the chip as it is likely a Samsung internal part.

http://www.docstoc.com/docs/68363045/ZigBee-Reference-Board-Manual-v01

Edit again: I should have googled this earlier. The SSD1623 is a generic display driver chip with an SPI interface for a 96 segment, three level display. It also has a built-in charge pump to generate high bias drive voltages for the display.

http://www.solomon-systech.com/en/product/display-ic/bistable-display-driver-controller/ssd1623/

It also looks like there are provisions for a real time clock chip on the bottom left side, but it is not installed.

I am not an expert in the exact operation of the technology, but I was a shop assistent in tesco, as a student in Hungary, where this ESL technolgy was installed first.

We have a device, which is a manual data collector using radio frequency to connect to the integrated computer system, where can be followed how the level of the stocks change, what are the typicalities of the different type of goods (like price, weight, name...) even through the whole supply chain. This device is able to read the different barcodes, so it is like a manual reader - with the same technology, which is used at the cashiers (red laser technology)

First - with this manual device - we get the barcode identifier of the exact product, and then with the right options on the device, we program this tag to have the datas of this special product (basically we connect them with this electronic technology). Every tag has its own kind of barcode, which we use to create this connection.

Then we have to activate this tag - we need another device for this, which called "clicker". Unfortunately I am not sure of the technological basics of this device, but I guess it could some infrared or bluetooth technology. Basically this is a device, which creates the active connection between the tag, and the integrated computer system.

I don't know if I could say something new, but I hope I could help a little :)