Conventional types of keyboard include
mechanical button and capacitive button. There is also a kind of keyboard with
light-touch membrane button among industrial personal computer keyboards.
Mechanical keyboard is a structure which has been applied at the earliest, with
the principal similar to touch switches where contactors are connected or
disconnected, which features in simple process, repair convenience, ordinary
hand feeling, large noise and easily wearing. Most cheap mechanical keyboards
use copper springs as elastic materials, and copper will be easily folded and
easily lose elasticity. Therefore, the fault rate will increase after a long
term of use. Capacitive keyboard is designed based on capacitive switch, which
changes inter-electrode distance to change capacitance and obtains temporary
conditions for vibration pulse to pass. Theoretically, such switch is of
noncontact type, and wear rate is extremely small and can even be neglected. It
has no risk of poor contact, and features in small noise and being easy to
control hand feeling, which can be used to produce high-quality keyboard, but
has more complicated process than mechanical structures. There is also a kind
of keyboard used in industrial personal computer, which applies light-touch
membrane buttons for full sealing, and is only suitable for special occasions.
Keyboard enclosure dimension, positioning of
keyboard circuit board, hole site and appearance of keyboard insulating film
Keyboard is the most common and uppermost input
device, which has a huge market demand. Among the electronic consumer goods,
generally, keyboard is a large-sized auxiliary device, and its frame and
membrane materials are electronic parts of larger size due to their overall
assembly. Large-stroke instrument is needed during testing for matching.
Meanwhile, large-stroke measurement instrument always has lower measurement
efficiency, especially for measurement of multiple dimensions of complicated
structures such as keyboard.
VMQ mobile-platform image measuring instrument
is an original high-efficiency and non-contact measuring instrument in this
field, which integrates high coverage, extended depth of field and long stroke,
and has improved measurement efficiency by more than 10 times. It is designed
with the function of coordinate registration, which can automatically match
work pieces and achieve automatic positioning. Within its large coverage range,
number of measured elements is not limited, all can be measured and several
keyboard jigsaws can be completed within 1 second at a super high efficiency.