Anti Light Series(3)
Source:Shenzhen TMD Technology Co., Ltd. | Author:Hebe | Publish time: 2017-08-14 | 652 Views | Share:
In recent years, with the maturity and extensive application of infrared technology, the insiders pay even more attention to “light resistance of infrared touch control product” than previously.

 

In recent years, with the maturity and extensive application of infrared technology, the insiders pay even more attention to “light resistance of infrared touch control product” than previously.

Today, I will talk about such topic with you.

Before talking about it, let us understand the development course of infrared screen.

1.Development course

G1

The infrared touch screen appeared early in 1992. Owing to the technological restriction, low resolution and easy to suffer from environment interference at that time, especially, it was required to be used in the shading environment, so it faded out the market at one time.

G2

It was pushed out in 1994. The resolution reached 64*64, and optical interference resistance was improved, so it was applicable to most indoor environment.

G3

It was pushed out in 1997. The resolution reached 320*240. It can be used outdoor except the direct sunlight.

G4

It was pushed out in 1998. The resolution reached 800*600.

G5

The resolution of infrared touch technology has been enhanced to 1000*72 and the strong light interference resistance has been enhanced to a level that it can be used under direct sunlight.

……

From the development course, it is seen, the main problem of infrared touch screen is about resolution and light resistance.

Since G2, optical interference resistance has been solved partly. G3 and G4 has made improvement, but failed to make breakthrough in major indicator or comprehensive performance.

Until G5, the function of various digital products is powerful increasingly, electronic technology is more advanced, PCB is smaller, integration is higher and resolution will not be a problem any longer. Moreover, people has made essential breakthrough in the service life and maintenance-free performance of product

 

 

2.Technical difficulty

The only difficulty is light resistance.

At present, G6 infrared touch screen is combined with Windows7 perfectly. It realizes multi-point touch and multi-posture identification. People can zoom, rotate and comment on it naturally.

Perfect touch control experience receives recognition of more consumers. With the popularity of touch control product outdoor, light resistance becomes an urgent problem to be solved.

Previously, a friend engaging on wechat cosmetics read the article and left message: why does it suffer from light interference?

It is because when the infrared receiving tube adopted by infrared touch screen, as the sensor, is exposed under the burning sun, it is easily interfered by the infrared ray in the sunlight and results in misoepration.

Additional comment:

The component of infrared receiver usually includes infrared receiver head, photosensitive diode or audion. There is a PD chip in these components, which receives infrared ray.

The function of infrared receiving is receiving infrared ray, so if the chip goes wrong, the infrared receiver will be out of order.

However, the PD can receive a section of infrared ray with wide range of wave length, so PD can receive infrared way whichever emitted from sunlight or infrared transmitting tube.

Therefore, when it was sunny outdoor, the sunlight is normally bright, infrared receiver will receive infrared ray in the sunlight and PD sensitization reaches a saturated sate, so it cannot receive infrared ray emitted from infrared transmitting tube.

It is just like a full man cannot eat any more.

 

 

3.Corresponding measures

Against such difficultly changed optical problem, vendors have racked their brains to take a series of physical measures to prevent the interference of visible light.

For example, they adopt opaque material for the outer frame, and the common material in the market is aluminum alloy; the inside frame is adhered with filtering strip on four sides to filter the stray light. In this case, only infrared light emitted by transmitting tube is allowed to pass.

However, aluminum frame is difficult to realize good waterproof effect. If it is used outdoor, waterproofing and dust resistance is a precondition.


Such method only cures the symptom, not the disease, so it is the temporary solution, but we all know it is not a permanent solution. To solve such difficulty, we should comply with optical theory, develop such optical technology and keeps improving.

 

Finally,

Shenzhen TMD Technology Co., Ltd. has developed a black technology-naked screen light resistance

(Note: it means it can be used normally under strong light outdoor even if there is no outer frame and naked screen.)

Let us see a video.

 

 

 

 

The breakthrough of naked screen light resistance makes the party who has ever declared the infrared touch screen is weak in light resistance shut up. Fact speaks louder than speaking.

 

Conclusion:

Such long anti-“sun” war is declared to be finished.

In the future, infrared touch screen will irrefutably become a necessary choice in the large-size outdoor product. It will overwhelm other touch control technologies with absolute advantage.