Capacitive touch screen will become the main trend in the future
Author:sunday Time:2021-06-10 11:22 Browse(966)
Smart phones, tablets, ATMs, subway ticketing machines Around us, there are widely distributed touch screens that can perform various operations only with finger touch.
one of them is worth our in-depth understanding.

Capacitive touch screen will become the main trend in the future

capacitive touch screen is growing with the popularity of smart phones.
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@ 8 '; nThe main material of touch screen is conductive transparent film, also known as "transparent conductive film", which is most widely used by ITO (indium tin oxide), The ITO film is made of indium tin oxide (ITO) crystal.
a thin insulating layer made of glass, plastic, etc. is covered on the ITO film.
the ITO film is divided into square ITO films with side length of about 4 mm.
the ITO films are arranged in the same row (or column).
the ITO films are connected by wires, The column (x-axis) connection (pink in the illustration) and the column (Y-axis) connection (blue in the illustration) are formed.
the columns connected in a string are called "electrodes"
the wires from each electrode pass through the outer edge of the screen and gather together in one place.
the touch screen that can "store" a large amount of electric charges can be operated by touching with fingers, Nowadays, it is inseparable from our life.
touch screen can identify the position of finger touch in several different ways.
70% of touch screens on the market are "capacitive"
in short.
the so-called capacitance is the ability of objects to store electric charges.
touch screens such as smart phones and flat panels usually have very weak current passing through.
we touch them with our fingers The capacitance of the electrode in the touch position will change, and the flow of electricity will also change.
when the screen is in the touch position, the capacitance of the electrode will changeBy measuring this change,
the position of finger touch can be determined.
to detect the intersection point of each electrode on the touch screen, multiple fingers (multi touch, such as page zooming, etc.) are sometimes used when operating with smart phones, flat panels, etc.
at this time,
it is impossible to correctly locate multiple fingers only by detecting the capacitance of the electrode, This requires further detailed analysis of the possible intersection points of electrodes.
some people may think that, no matter whether the touching place is one or more, just analyze the intersection points of electrodes one by one and determine the touching position directly? However, compared with the total number of electrodes on the screen, the total number of intersections of the electrodes on the screen is much more, and it will take several to several hundred times more time to analyze all the intersections one by one than only detecting the electrodes.
capacitive touch screen adopts two detection methods: if it is judged as a single touch, the capacitance of each electrode is determined first; if it is judged as a multi touch, the capacitance of each electrode is determined first, The point of intersection of electrodes will be further analyzed in detail.
in addition to capacitive touch screen, resistive touch screen is widely used.
resistive touch screen is made by overlapping two layers of transparent conductive film with a very small interval.
the resistive touch screen is composed of two layers of transparent conductive film The position of the finger can be determined by the depression produced when the finger (or stylus, etc.) presses the screen.
because the upper film of the depression is in contact with the lower film, the position of the finger can be detected.
the two films are the same as the capacitive film.
there is also voltage and current passing through.
when the two films are in contact.
the current will pass between the films, The voltage value on the membrane will also change.
the voltage value on the membrane will changeBecause the voltage value has changed.
it is clear where the two films contact (i.e. where the finger presses).
the current direction of the upper and lower films is different.
for example.
the upper film is applied with voltage in the x-axis direction, and the lower film is applied with voltage in the y-axis direction perpendicular to the x-axis of the upper film.
when the finger presses the touch screen.
when the two films contact each other, The position can be determined by measuring the voltage in the x-axis and Y-axis directions in turn.
the representative products of this resistive touch screen are Car Navigator, portable game console, etc.
the touch of resistive touch screen and capacitive touch screen are different.
the former does have a concave feeling.
in addition.
if you carefully observe the resistive touch screen, Maybe you can see that there are many tiny points on the screen.
these points are called "isolation points."
they are made of resin, which can maintain the gap between the upper and lower films.
now capacitive touch screen will gradually replace resistive touch screen.
they are widely used, Shenzhen Yunli Electronics Co., Ltd. specializes in manufacturing capacitive touch screen in vehicle, medical, smart home, industrial control and other fields.
it can achieve touch with water, touch with gloves, Ag ar AF effect, and perfectly fit LCM and CTP through optical binding.
main business: 1.4-inch capacitive touch screen, 3.5-inch capacitive touch screen, 4.3-inch capacitive touch screen, 5-inch capacitive touch screen 7 inch capacitive touch screen 8 inch capacitive touch screen 10.1 inch capacitive touch screen! ]"| 7 A6 E1 w9 W4 K.
thank you for sharing.
thank you for sharing
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