According to ODO :
Technology: is both countable and uncountable.
( mass noun) The application of scientific knowledge for practical purposes, especially in industry:
advances in computer technology,;
[count noun]: recycling technologies. ( specific technologies).
These new technologies can be useful, if we apply them to practical problems.
The lead times for developing new technologies in the nuclear industry are very long.
New technologies in medicine are crucial and will have an enormous impact.
Machinery and devices developed from scientific knowledge:
it will reduce the industry’s ability to spend money on new technology
As for your examples, if you want yo stress the different technologies available in the display sector, the plural form is more appropriate.
Ngram: display technology vs display technologies.
Source: www.oxforddictionaries.com