How to distinguish Infrared touch screen advertising machine

How to distinguish Infrared touch screen advertising machine true and false two points

Infrared touch screen advertising machine true and false two points in the picture, zoom in function seemingly no difference, but carefully found that there is still a big difference between the two technologies.
1, true two-point infrared touch screen advertising machine principle:
Generally, an outer frame is mounted on the front of the display screen, and a circuit board is arranged in the outer frame. There are uniformly arranged infrared emission tubes and infrared receiving tubes in the X and Y directions, and the transmitting/receiving devices in the right and oblique directions are scanned. In the one-to-many mode, horizontal and vertical oblique infrared cross arrays are formed. When the user touches the screen, the touching object (finger or other object) will block the cross infrared rays passing through the position, and the controller can obtain the true multi-point coordinate position through the calculation.
2, false two infrared touch screen principle:

Generally, an outer frame is mounted on the front of the display screen, and a circuit board is arranged in the outer frame. In the X and Y directions, there are uniformly arranged infrared emitting tubes and infrared receiving tubes, which form an infrared matrix that intersects horizontally and vertically. When the user touches the screen, touching the object (finger or other object) will block the horizontal and vertical infrared rays passing through the position, and the controller can determine the position of the touch point on the screen through calculation.

The fake two-point touch screen usually only correctly identifies one point, but when putting two touch objects, the system actually gets 4 points of data, namely XA, XB, YA, and YB. The coordinates of these four points can be combined in pairs. Out of 4 coordinate points, namely A (XA, YA), B (XB, YB), C (XA, YB), D (XB, YA). When the touch points are two points A and B, the fake two-point touch screen cannot determine whether the touch position is A, B or C, D. However, when the two touch points A and B are close to or separate from each other, the distances between the corresponding pseudo points C and D are also close to or separate from each other. By calculating the relative position, the fake two-point touch screen can detect two gestures of zoom-in and zoom-out. However, when the fake two-point touch screen performs the rotation gesture judgment, it is relatively easy to cause an erroneous operation. Generally, if two points are required to perform a rotation gesture, one of the points is fixed, and the other starts a clockwise or counterclockwise relative movement from the upper right of the fixed point, or requires the touch points to fall respectively, so that the system can touch the points separately through the time difference. Real location. However, when the two touch points of the fake two-point touch screen (such as A and B) are in the horizontal or vertical position, since the positions of the ghost points (such as C and D) will change, the rotation action is likely to cause errors. The specific performance is that the direction of the finger motion has not changed, and the operation object, such as the rotation direction of the picture, has undergone an inverse change.

The fake two-point touch screen cannot completely solve the above problem in principle, and thus may bring instability to the touch operation. According to comparison, the error rate of the products of different touch screen manufacturers in the existing market is between 20 and 80. The true two-point touch screen can completely calculate the positions of two touch points due to different principles, so there is no such problem.
Analyze the difference between a true two-point touch screen and a fake two-point touch screen

1, in the picture rotation:
True two points on the touch screen by two different touch points on the picture rotation operation, the picture rotation direction and the direction of the touch rotation, no error rate;
Fake two points on the touch screen by two different touch points on the picture rotation operation, the picture rotation direction and the direction of the touch rotation, the rotation rate of the same error rate up to 40-80.
2, in writing:
True two points can always maintain an accurate response to the touch of a finger, both hands are crossed at the same time, and the error rate of line breaks and jumpers is almost equal to zero.
There are 20-80 error rates when writing two hands at the same time. For example, if two hands simultaneously draw lines, the lines will be broken and jumped.
3, in the two points of operation:
True two-point drift and ghost phenomenon are almost absent. There are two real-touch screen manufacturers with unstable technical issues, and there are about 5 ghost spots and drift occurrence rates.

The above has said so much, I just want to separate the analysis of the differences between the two-touch screen and the fake two-touch screen. Through the above introduction, we must have a deeper understanding of their differences

Shenzhen ZSG Electronics Co., Ltd.It is a Domestic professional development design, production, sales of liquid crystal display equipment and related electronic products enterprises.Contact us: shouxian@gdzsg.com