What is Capacitive Touch Screen?

Capacitive touch screen mainly uses the current sensing of the human body to work.

Capacitive touch screen principle:
Capacitive screens work through any object that holds an electric charge, including human skin. Capacitive touch screens are made of materials such as alloys or ITO, and the charge is stored in tiny static wires thinner than a human hair. When the finger clicks the screen, it will absorb a small amount of current from the contact point, causing the corner electrode to drop, and the use of sensing the weak current of the human body to achieve the purpose of touch. That's why touch doesn't respond when we touch the screen with gloves on.

Surface capacitive touch screen structure type：
The basic structure of the screen is divided into three layers from top to bottom, protective glass, touch layer, and display panel. In the production process of the mobile phone screen, the protective glass, the touch screen and the display screen need to be fitted twice.
Due to the protection glass, touch screen, display screen after each lamination process, the yield will be greatly reduced, if you can reduce the number of lamination, will undoubtedly improve the yield of full lamination. At present, the more powerful display panel manufacturers tend to promote 0n-Cell or In-Cell solutions, that is, tend to make the touch layer on the display screen, and touch module manufacturers or upstream material manufacturers tend to OGS, that is, the touch layer is made on the protective glass.
In-Cell: refers to the method of embedding touch panel functions into LCD pixels, that is, embedding touch sensor functions inside the display, which can make the screen thinner and thinner. At the same time, the In-Cell screen should also be embedded with a matching touch IC, otherwise it is easy to lead to wrong touch sensing signal or excessive noise. Therefore, In-Cell screens are purely self-contained.
On-cell: refers to the method of embedding the touch screen between the color filter substrate and the polarizer of the display screen, that is, the touch sensor is equipped On the LCD panel, which is much less difficult than the In-Cell technology. Therefore, the most frequently used touch screen On the market is the on-cell screen.
OGS(One Glass Solution):OGS technology is to integrate the touch screen with the protective glass, plating ITO conductive layer on the inside of the protective glass, and directly coating and lithography on the protective glass. Since the OGS protective glass and touch screen are integrated together, they usually need to be strengthened first, then coated, etched, and finally cut. This cutting on the reinforced glass is very troublesome, high cost, low yield, and causes the formation of some capillary cracks along the edge of the glass, which reduce the strength of the glass.

3m surface capacitive touch screen advantages and disadvantages:
1. In terms of screen permeability and visual effects, OGS is the best, followed by In-cell and On-Cell
2, The degree of thinness, generally speaking, In-Cell is the lightest and thinnest, OGS is second, and On-Cell is slightly worse than the first two
3, Screen strength (impact resistance, fall resistance), 0n-Cell is the best, OGS is second, In-Cell is the worst. It should be noted that OGS directly integrates Corning protective glass with the touch layer, which weakens the strength of the glass and makes the screen fragile.
4, OGS touch sensitivity is better than On-Cell/ In-cell screen, multi-touch, finger, Stylus stylus pen support, In fact, OGS is also better than In-cell /On-Cell. In addition, because the In-cell screen directly integrates the touch layer and the LCD layer, the sensing noise is large, and a special touch chip is required for filtering and correction. OGS screens are less dependent on touch chips.
5, Technical requirements, In-Cell/On-Cell are more complex than OGS, production control, the difficulty is higher.