Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 10 Inventions on Keyboard Key Switch Mechanism   The key switches of the keyboard of a computer system are generally comprised
of a key cap having a plunger, conductive rubber disposed above a membrane
circuit and compressed by the plunger to trigger the membrane circuit causing
it to produce an electric signal to the computer.
  Some key switches use springs. Some other keyboards use rubber domes or a
dome sheet, which do the function of springs. When the user depresses the key
button the spring or domes collapse. The key switch depresses the key stem,
which actuates the button on the membrane circuit. When the user releases the
button the springs or rubber domes push the button up to the rest position.
  This article illustrates 10 inventions on different key switch mechanism. The
inventions are selected from US patent database. The inventions try to simplify
the mechanism, reduce manufacturing cost, increase accuracy and reliability,
and increase strength and robustness of the keys.

19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an