Technical differences between in-cell, on-cell and ogs full screen fitting

3, which was just released yesterday, uses the ogs full screen fitting technology, including meizu mx3. However, iPhone 5 is an in-cell screen technology. What is full screen fitting? What is the difference between them? Which one is better? Today, I will popularize the fully-fit screen technology, including in-cell, on-cell, and ogs.

What is full fit?

The competition for smart mobile phones is becoming increasingly fierce. Many manufacturers want to differentiate their hardware to highlight their new terms such as IPS, SLCD, retina, and clearblack, many times, when we do not understand new technologies, new technical terms are born again. Recently, many mobile phone manufacturers have begun to use the "full fit" technology to add selling points for their mobile phones? Let's take a look at what this is.

1. Screen Structure

From the screen structure, we can roughly divide the screen into three parts: glass protection, touch screen, and display screen. The three parts need to be fitted. Generally, the glass and the touch screen need to be fitted twice, while the screen and the screen need to be fitted once. According to the method of fitting, there are two types: Full Pasting and frame pasting.

2. Frame

The so-called frame sticker is also called the mouth-to-mouth adhesive tape, that is, the touch screen and the display side are fixed with a double-sided tape, which is also the current most of the screen bonding method, the advantage is that the process is simple and cost-effective. However, because there is an air layer between the display screen and the touch screen, the effect of the display is greatly reduced after the light is reflected.

3. Full fit

The full fit means that the Panel and the touch screen are completely pasted together by water glue or optical glue in a seamless manner. Compared with box stickers, it can provide better display effects. Currently, the most common full-fit screens on the market are ogs solutions dominated by the original Touch Screen manufacturer and on cell and in cell technology solutions led by panel manufacturers.

Full fit advantages: the full fit technology removes the air from the screen, which helps reduce the reflection between the display panel and the glass, so that the screen looks more transparent and enhances the Display Effect of the screen.

IMac reflection with full fit technology reduces by 75%

Another advantage of fully-fit technology is that the screen will no longer go gray. The Touch module is also closely integrated with the panel to improve the intensity. In addition, the full fit can effectively reduce the interference caused by the display panel noise on the touch signal. Although the advantages of full fit are huge, the yield rate is relatively low. The consumption and decommission of the surface glass and even the Panel during the fitting process due to poor performance will inevitably lead to an increase in costs, therefore, the control of bubble stripping and bonding yield will become more important than material costs.

Fully fit in-cell, on-cell, and ogs screen technology

During the production process, the screen of the mobile machine must be fitted with the glass protection, touch screen, and display. If the screen is pasted with a frame, the display effect will be greatly reduced, however, it would be a problem to adopt a fully qualified yield rate. The yield rate will be greatly reduced because each fitting process between the glass, touch screen, and display screen is passed. If the number of fitting times can be reduced, the overall yield rate will be increased, there are several development directions: ogs/TOL solutions led by the original Touch Screen manufacturer, and on cell and in cell technical solutions led by the Panel manufacturer.

Strong display panel manufacturers tend to promote on-cell or in-cell solutions, mainly because they have the display production capability, that is, they tend to make the touch layer on the display; manufacturers of touch modules or upstream materials tend to be ogs, that is, the main reason for making touch layers on protected glass is that they have strong manufacturing capabilities and technologies. Both of them can reduce the number of fit times, thus saving costs and improving the fit rate. In addition, because of the absence of a touch layer, it can also reduce material costs and reduce the size, and Apple iphone5 adopts in-cell technology.

1. In-Cell

In-cell refers to the method of embedding the touch panel function into the LCD pixel, that is, embedding the touch sensor function inside the display, which can make the screen thinner. At the same time, the in-cell screen also needs to be embedded with a matching touch IC, otherwise it will easily lead to incorrect touch sensing signals or excessive noise. Therefore, for any display panel manufacturer, the entry into the in-cell/on-cell touch screen technology is indeed quite high, and the low yield rate is still required. Currently, in-cell technology is used in addition to Apple's iPhone 5 and Nokia's lumia920. The iPhone 5 screen thickness is estimated to be 2.54mm, and the contribution of in-cell thinning is 0.44mm, accounting for about 1.7 of the decrease in thickness.

Although Apple is promoting in-cell technology, it will still be limited to high-end smartphones in the next few years. The main problem is the yield rate, because in-cell damage not only results in touch screen damage, but will also result in decommissioned display. Therefore, manufacturers have higher requirements on in-cell yield.

2. On-Cell

On Cell refers to the method of embedding the touch screen into the color filter substrate of the display screen and between the eccentric film. That is, the touch sensor is configured on the LCD panel, which is much more difficult than in cell technology. Samsung, Hitachi, and LG have made rapid progress on the on-cell structure touch screen. Currently, on cell is mostly used in Samsung AMOLED panel products, technically, it is still unable to overcome the problem of uneven color produced by thin and touch.

3. ogs/TOL

The ogs technology integrates the touch screen with the protective glass. The ITO conductive layer is plated on the inside of the protective glass and is directly coated and photoprinted on the protective glass. As a result, it saves one piece of glass and one-time fitting, the touch screen can be thinner and cheaper. Currently, Chinese mobile phone manufacturers such as Tianyu Bumblebee 1 generation, Jin lifeng Hua, and 2 have all adopted ogs technology. However, the ogs still faces the problems of strength and processing costs. Since the ogs protection glass and touch screen are integrated, it is usually necessary to first strengthen, then coating, etching, and finally cutting. In this way, cutting on the reinforced glass is very troublesome, with high cost and low yield, and some capillary cracks are formed along the glass edge, which reduces the strength of the glass, at present, insufficient strength has become an important factor restricting the development of ogs.

In some touch manufacturers' internal documents, Tol (touch on lens) is used to express ogs. (The tol/single glass of mx2 is essentially the same as the ogs of ) the technology of forming ITO conductive film and sensor directly on the protective glass, A piece of glass protects both glass and touch sensors.

 

4. In-cell, on-cell, ogs, And GG screen comparison