When will the cicret bracelet go on sale?

Cicret is just the imagination of a designer who lacks engineering knowledge background, and it can't be done.

Unreasonable reasons:

Exquisite one: standby time is a tragedy.

For today's wearable devices, standby time is always painful. The smaller the built-in battery, the worse the standby time. This is also the reason why most manufacturers like big-screen mobile phones. There is a self-evident hidden advantage: the larger the mobile phone, the greater the battery capacity, while most of the remaining devices do not need to increase in size, so the power/power ratio of the big mobile phone will be much larger than that of the small mobile phone.

Then the conversation turned back, and Cicret did the opposite. For a small bracelet, it is difficult for ordinary electronic equipment to shrink (unless the performance index is given up), and the only thing that can freely expand and contract is the battery. Let's take a look at the structure diagram of the bracelet imagined by the inventor of Cicret:

Exquisite 2: Wonderful wrist projection

Cicret's mini-projector is actually a miniature projection. At present, all ready-made mini-projector on the market have the same normal physical world outlook as ordinary projectors, that is, the projection plane is almost perpendicular to the projection direction of light, while the wrist projection of Cicret requires that the projection plane is almost parallel to the projection direction.

Do a simple calculation, take the effect diagram of the fruit cutting game as an example, assuming that the projection point is away from the skin 10mm (the margin has been seriously relaxed, according to the inventor's idea, so the finger will block the light, and the projection point must be very low); The screen is the size of fruit 4s: 3.7 inches, 640x960；; The horizontal distance between the visual screen and the bracelet is about10 mm. In this way, we can calculate:

1. On the side of the screen closest to the bracelet, the projection angle of the projector is 123 degrees wide. All I know is that camera lenses with a viewing angle exceeding 120 degrees are rare.

2. On the farthest side from the bracelet, the incident angle of light is 6.5 degrees, and the opening angle between two vertically adjacent pixels is about 0.006 degrees; On the nearest side, the opening angle between two vertically adjacent pixels is about 0.233 degrees. That is, when the brightness of the light projected to the farthest side reaches (0.233/0.006)=38.8 times that of the light projected to the nearest side, the display brightness on both sides can be guaranteed to be the same.

3. If the height of the projection point is reduced to 2mm according to the requirements of the inventor, the above estimation parameters will become: the proximal opening angle is 137 degrees; The far incident angle is 1.3 degrees; The brightness difference between the far side and the near side is 66.4 times.

"I'm not an optical expert. I dare not say that this thing must not be done, but it feels super challenging. Assuming there is, it can be said that if the miniaturization, power consumption and heat dissipation of this projection technology are not considered, I just need to make a box as big as a DVD player and put it under the wall. A 100 inch projection TV can be made in minutes, and all TV sets and display products on the market will be destroyed immediately. Unfortunately, there is no such projection TV on the market. I don't know if it is too difficult or everyone didn't expect it, hehe. "

Exquisite 3: Irregular arm

The above analysis is based on the projection on the plane, and there is a more embarrassing problem that the arm is an irregular surface, which will bring the following troubles:

1. Projection has to compensate the surface, which is a challenge to the processor, memory and battery life.

2. Some positions on the long side of the screen are likely to exceed the range of projection points, especially for people with small bodies and thin arms. Personally, I think that finding this problem only requires a little space imagination and common sense of life, and does not require a professional foundation of science and engineering. )

3. Considering that the incident angle of the far edge of the screen is only about 1~6 degrees, this projection effect will be extremely sensitive to any position change of the bracelet, and it will change dramatically or even disappear when the screen is slightly shaken. You want to tighten the bracelet, don't you? Meat is elastic, and when the projector is clamped, it will sink into the meat.

4. Because the incident angle is too small, any tiny obstacle on the skin surface will drag out a long shadow. Because of the surface problem, this product rejected a large number of petite orientals; And how to solve the problem of skin surface obstacles.

Based on the above points, Cicret faces many challenges. Unless you can accept the slag screen effect, you may not be able to support the battery life of long-term calls. Even so, they still need to widen and thicken the bracelet to insert enough batteries and necessary electronic equipment; And the screen size is greatly reduced, thus reducing the difficulty of optical and curved surface compensation.

But don't forget that there is a paradox here. If the bracelet is widened and thickened to the size of a watch and the screen is reduced to only one or two inches, why not make a smart watch from the beginning?

In addition, the current technology cannot make these "virtual touch screens" achieve the same response speed and accuracy as glass screens. More importantly, the extremely low resolution and mosaic-like image quality are even more maddening. For example, the typing efficiency of laser keyboard is always so unpopular.