Flat display is to provide a variety of information for pilots, pilots must be able to see it clearly, when the J-7M test flight, Qin Feng has experienced the whole process, most of the time, in solving situations such as the blurred image of the flat display, until later when the Pakistani brothers came to test flight, it was considered to be stable, clearly visible.

Only when the pilot can clearly see this information can it be of practical significance, and there is a gap in this aspect of refraction.

The refractive head-up display was the first to be put into use, the computer receives the data sent by the interface unit, generates a signal after processing, controls the electron beam in the CRT to produce an image, and then projects the image on the display unit through a set of parallel lenses and a translucent mirror. The mirror surface of this display allows light to pass through the outside world, while the light from the CRT is reflected into the pilot's eye.

Depending on the angle, there may be two pieces of glass, which have undergone a refraction in the middle.

Compared with the original way, this has been improved a lot, but the green circle in front will also make people a little uncomfortable, so many veterans of flying J-7 like to turn it off, feeling that it blocks the light, and at the same time, its field of view is not wide enough.

As for the diffraction flat display, it is mainly the mechanism on this glass, which is no longer pure flat, but has a certain arc, and at the same time, the area of this glass has also become larger.

If Qin Feng had been more careful just now, he would definitely have been able to see it, but his eyes were mainly attracted by the three display screens below, and he didn't pay much attention to the glass above.

As for diffraction, it is a special phenomenon, the most common is sound, and this is what the wall has ears to say, sound bypasses obstacles!

Sound can go around because the wavelength of sound is very long, and this phenomenon can only occur when the wavelength is close to the size of the obstruction or slit, and it is difficult for light to see the diffraction phenomenon because the wavelength of light is very short.

In fact, if you look at the blade in the sun, you can see that the edge of the blade is blurred, which means that the light no longer travels in a straight line, bypasses the edge of the blade, and goes to the back of the blade, which is the diffraction of light.

It's easy to say, but it's not easy to apply it, and Israeli research in this area is quite advanced, and they have successfully developed diffraction flat displays.

This is made of curved glass with small etching lines, and the light is not reflected, but diffracted into the pilot's eye.

The aperture of the lens of the ordinary refraction flat display can not be too large, just like the previous telescope, there is serious distortion, the larger the image, the more obvious the distortion, therefore, the ordinary refraction flat display, are a small piece of glass, the general field of view will not exceed the level of 20 cm horizontally, and the degree of pitch 15 cm.

But what about diffraction heads-up? It's called Wide Angle because its field of view is 30 centimeters horizontally and 20 centimeters in pitch, which is four times the size of the original!

A larger area means more content can be displayed on the glass!

The hologram is also based on diffraction, and the way of diffraction can superimpose the original figure more perfectly, with almost no distortion.

Another reason is that the holographic lens also filters out non-visible light, which makes the image clearer and brighter.

Clearer, brighter, and more content displayed, diffraction heads-up is certainly a representative of the advanced, and now, Israeli companies have overcome this technical hurdle.

Other advantages are many, for example, it has almost no bezels, and the obscuration of the front field of view, which is most important to the pilot, is minimal.

In this field of technology, Israel is definitely at the forefront of technology, and their Lion fighter jets will use this latest type of heads-up display.

The gap in China is much larger, and now the country can only be imported from the Marconi company, and has not yet realized its own manufacturing, and it will take more than ten years to transition to diffraction flat display.

However, compared with the country, the progress of the Soviets is even more backward, in later generations, when the introduction of the Su-27SK, the Air Force believes that the technical level of the ILS-31 equipped on the Su-27 is equivalent to the JHK-13E head-up display system on the J-8B fighter, and so on more than ten years later, when the Su-30MKK is introduced, the Su-30MKK is still ILS-31, and they have completely stagnated in this regard.

Later, when India introduced the Su-30MKI, it chose Israel's EL-OP SU967 head-up display.

A small piece of glass, there is such a big knowledge, people are full of emotion, the country is backward, we must take a step, keep running forward, absolutely can not continue to lag behind, otherwise, there is no way to catch up.

Facing the small glass, everyone was silent for a long time, the cockpit of the other party, it is worth learning a lot, this time to investigate, absolutely not in vain, what the future fighter will look like, how to build, they are more confident.

In addition to the display device, of course, there is also the operating lever inside.

The Israeli Air Force already has the F-15 and F-16, of which the F-16 is the most rebellious, it uses a side stick operation, the steering stick is no longer between the legs, but on the right, when the big overload maneuveres, the seat automatically turns back, if it is a center stick, the hand is out of reach.

At the same time, this kind of sidestick operation is another place against the sky, that is, it does not have the movement of position, it feels the strength of the pilot, the pilot has a large force, and the rudder surface of its operation responds quickly.

The current cockpit uses the ordinary center lever method, but the buttons arranged in different positions on the lever represent that the hand can be operated without leaving the lever.

Everyone stayed in front of this model for nearly two hours, and finally, someone proposed: "Can we take a group photo in front of this model of the fighter?" ”

If this fighter was extremely secretive, it would definitely not work, but now, when I heard that I was going to take a group photo, Saraf who was present had no objection, and he even pulled Ramour and others to stand over, and everyone stood in front of the plane in two full rows.

"Click, click." The photographer took a photo for everyone, frozen in this moment, one day in 1986, the Chinese delegation inspected the Israeli LAVI Lion fighter, and in front of the fighter, cordially took a group photo, since it is a souvenir, then everyone wants a photo.

This photo needs to be kept secret for the time being, but for a long time afterward, everyone will continue to take it out and look at it, and use this photo to inspire everyone to keep moving forward!

The delegation left after the inspection, and as for Qin Feng and the other two test pilots, they began a new experience.