Huawei has increased the screen-to-body ratio and made a major transformation to the OLED screen

According to morning rumors, following the Mate 30 series, Huawei will launch a more innovative full-screen mobile phone on October 17, which may also be equipped with the Hongmeng system.

"All statements about Hongmeng are speculations." A Huawei insider told reporters that building the HMS ecosystem is a top priority for Huawei, and Hongmeng will not be used in mobile phone products this year. Huawei officials did not respond to this news.

Nevertheless, as the functions of mobile phones continue to diversify, mobile phones are integrated with a variety of devices for realizing different functions, such as optical devices such as cameras and fingerprint sensors. In order to increase the screen-to-body ratio of the mobile phone display (the ratio of the effective display area of ​​the display to the entire display), in the prior art, when the optical device is not in use, the optical device can be set on the back of the mobile phone housing. When the user uses the optical device, the optical device can be flipped or popped out to avoid the optical device occupying the area of ​​the display screen, thereby increasing the screen-to-body ratio.

However, a rotating mechanism for flipping and a first telescopic mechanism for popping out need to be provided between the optical device and the housing of the mobile phone, which results in a complex appearance structure of the entire mobile phone and reduces the smoothness of the appearance of the entire mobile phone.

On March 4, 2019, Huawei applied for an invention patent titled "Display terminal, mask assembly, evaporation system and control method thereof" (application number: 201910160495.7), and the applicant was Huawei Technologies Co., Ltd.

Based on the currently disclosed patent information, let us learn about this method of increasing the screen-to-body ratio.

We all know that OLED displays have excellent display effects, especially some flagship phones will use OLED screens to improve their competitiveness. Mobile phones are getting thinner and thinner, which is also a trend favored by users. In recent years, the pursuit of extremely high screen-to-body ratio has put forward great requirements on the technology of major manufacturers. OLED displays mainly have at least one thin film layer for displaying images. So can the thickness of the thin film layer be reduced to place optical devices such as front cameras and face unlock sensors in it?

The answer is yes. The main design idea of ​​the patent is as follows: the display includes an OLED display screen and an optical device. Among them, the OLED display screen has a display area, and the optical device is located in the display area of ​​the OLED display screen. In this case, by thinning the thickness of part of the thin film layer in the display area of ​​the OLED display screen, a storage space for accommodating at least a part of the optical device is formed. The purpose of setting the optical device in the display area of ​​the OLED display screen is achieved. In this way, the optical device can be set inside the display terminal, and reducing the size of the optical device has a greater impact on the thickness of the display terminal.

Let's take a look at the structural diagram of the OLED display:

       As shown in the figure above, the OLED display screen includes: a substrate, a plurality of first electrodes (121), a pixel definition layer, a plurality of organic light-emitting layers, and a second electrode (122). The plurality of first electrodes are arranged at intervals on the substrate (12), and the material of the substrate can be a glass substrate, a hard resin substrate, or other flexible materials. It can be seen that this method is not limited to the material of the substrate, so in the currently popular folding screen, this method can also be used to increase the screen-to-body ratio.

The pixel definition layer is located on the substrate and has a plurality of grooves (11), wherein a first electrode is exposed at the bottom of a groove. Each organic light-emitting layer is located in a groove and is in contact with the first electrode in the groove. The second electrode covers all the organic light-emitting layers.

       The first electrode may be an anode of the OLED device, and the second electrode may be a cathode of the OLED device. The thickness of the second electrode in the region where the optical device is located is less than the thickness of the remaining portion of the second electrode. By reducing the thickness of the second electrode in the OLED display screen, a receiving space for receiving at least a portion of the optical device is formed.

       As shown in the above figure, this is the mask part that is focused on improvement in the display device. Since the purpose of placing optical instruments is achieved after the film thickness at the second electrode position of the display screen is thinned, this structure is explained.

       The first mask (31) in the figure includes a plurality of first openings (310) surrounded by first shielding strips (311). The openings have the same size and shape as the display area of ​​the OLED display screen. In addition, the mask assembly also includes a shielding portion arranged in the first openings.

        In this case, since the shielding portion (30) can shield the evaporated film-forming material, on the substrate to be evaporated, in the display area where each OLED display screen is located, at the position corresponding to the shielding portion, the thickness of the second electrode is smaller than the thickness of the second electrode at other positions, thereby achieving the purpose of reducing the thickness of the second electrode of the OLED display screen at the position corresponding to the optical device.

       The above is the technology for modifying the structure of OLED display screens to achieve a larger screen-to-body ratio. Every time the mobile phones we use daily bring new experiences to users, there are such extremely complex patents supporting them. It seems that removing the optical sensor from the front panel is a small operation, but it requires the modification of the structure of the entire OLED screen. At present, as the screen-to-body ratio has attracted more and more attention, many other mechanical structure designs have also appeared. Please pay attention to the patent decryption section, and the subsequent content will be more exciting!