The basic structure of touch screen technology consists of decryption and contrast

- May 23, 2019-

To fully understand in-cell/on-cell/OGS and so On, you need to know the basic structure of the screen.

The hype about the concept of the screen, from the previous IPS, AMOLED, SLCD panel debate, to now all the colors to advertise themselves as OGS fully fit screen, how thin, light, image "emerge" On the screen, apple seems to be more "high-end", out of the in-cell/on-cell concept.Small make up this period about OGS/in-cell/on-cell screen science, strive to understand, hope to let you know the truth In a simple way.

From top to bottom, the basic structure of the screen is divided into three layers: protective glass, touch layer and display panel.

There's nothing to protect glass, corning gorilla glass is.The touch layer is composed of ITO touch film and ITO glass substrate.The display panel has a high degree of subdivision and is only roughly arranged from top to bottom: upper glass substrate (pink area marked with Colorfiliter), liquid crystal layer (blue bar), and lower glass substrate (pink area marked with Array, namely thin film transistor substrate)., also need to point out is, protecting the glass/touch between layers and display panels, generally laminating technology will form a layer of air (that is, the annotations in the golden area of the Bonding), if the whole joint technology to remove the air layer, reflective screen will be reduced greatly, light up when the screen is all the more transparent, screen out more dark, not grey.

Traditional G/G and GFF screens are all standard protective glass + touch layer + display panel layer. The difference lies in the touch layer.The touch layer of G/G screen is composed of 1 layer of ITO glass substrate +1 layer of ITO touch film, while the touch layer of GFF screen has 2 layers of ITO glass substrate +2 layers of ITO touch film (ITO: X and ITO: Y).Clearly, the G/G screen is thinner.

Today, manufacturers flaunted OGS screen, InCell/OnCell screen, why it is worth boasting, because they are protective glass layer + display panel layer structure, less a touch layer, more thin.Where is the middle touch layer?This is what separates the InCell/OnCell screen from the OGS screen.The InCell/OnCell screen integrates the touch layer with the display panel, and the OGS screen integrates the protective glass layer with the touch layer.In order to fight for the right to speak In the industry, touch module manufacturers push the OGS, while display panel manufacturers such as LG, samsung and sharp push in-cell/on-cell.

One might also wonder, since both the InCell screen and the OnCell screen combine the touch layer with the display panel, how do you distinguish InCell from OnCell?This depends on where the ITO film is embedded in the display panel.OnCell is the ITO touch film that sits on top of a glass substrate on a display panel, as samsung has done with previous generations of its Galaxy flagship.In the case of the in-cell, the ITO touch film is placed under the glass substrate of the display panel, typically fused with the liquid crystal layer, representing the iPhone5.

In-Cell, On-Cell, OGS because of the different structure, the screen light and thin degree, display effect, manufacturing cost, yield are different.

1.In terms of screen transparency and visual effects, OGS is good, followed by in-cell and on-cell.So, brag about in-cell/on-cell how transparent, how good the visual effects, can rest.Whether it's the iPhone5 or the samsung GalaxyS4, the pure screen transparency isn't as good as some domestic phones with OGS screens, such as the meizu MX3.

2.In general, the in-cell is thin and light, which is one of the reasons the iPhone is still thin and light with its metal body.OGS is second, and on-cell is slightly worse.

3.Screen strength (impact resistance, fall resistance), On-Cell good, OGS second, In-Cell poor.It should be noted that OGS directly integrates corning protective glass with the touch layer, which weakens the glass and makes the screen fragile.As for the poor strength of in-cell screen, the author is not quite clear about the reason, which may be related to the current apple's own in-cell pursuit of thinness, Lumia920 is also in-cell screen, but there are good auxiliary design/measures to enhance the screen impact resistance, anti-fall ability.In addition, it should be pointed out that because in-cell integrates the touch layer with the liquid crystal layer, once the touch screen goes wrong, it needs to be replaced together with the display panel.

4.On the touch side, OGS has better touch sensitivity than on-cell/in-cell screens, but that's not always a good thing.OGS technology is not pass, ultra-high sensitivity is very easy to occur "screen" phenomenon, subtle dust, sweat, water vapor can cause the touch screen "misoperation", such as MX3 early a batch of machines this problem is more serious.In fact, OGS is better than in-cell/on-cell In the support of multi-touch, finger and Stylus Stylus.In addition, because the in-cell screen directly integrates the touch layer and the liquid crystal layer, the sensor noise is large, and special touch chip is needed for filtering and correction.OGS screens rely less heavily on touch chips.

5.Technical requirements, in-cell/on-cell than OGS are more complex, production control, the difficulty is higher.

6.In terms of the yield rate, the previous in-cell screen yield rate is low, which largely affects the supply of iPhone5 and other products, but as manufacturers continue to invest and technology maturation, in-cell/on-cell screen yield and OGS have been at the same level, large-scale shipment is not a problem.