CN102760009B - Two-sided touch screen based on printed circuit board and two-sided touch-control implementation method - Google Patents

Abstract

The invention relates to the field of electronics, and discloses a printed circuit board-based double-sided touch screen and a method for realizing double-sided touch control. In the present invention, the effective touch surface of the printed circuit board includes front and back sides, and at least one intermediate layer connected to a fixed potential is provided between the front and back touch surfaces. Since the intermediate layer is connected with a fixed potential, the interference between the double-sided touch panels can be eliminated, that is, the touch on one side will not affect the touch on the other side, and the single-sided touch can be extended to double-sided touch. The two sides of the printed circuit board have touch detection function at the same time, thereby saving system space and reducing system design cost. Alternatively, by increasing the thickness of the printing plate and reducing the mutual interference between the front and back touch surfaces, double-sided touch can also be realized, saving system space and reducing system design costs.

Description

Double-sided touch screen based on printed circuit board and method for realizing double-sided touch

technical field

The invention relates to the field of electronics, in particular to capacitive touch technology.

Background technique

The rise of capacitive touch technology has brought great convenience to people's production and life. This technology first divides the touch detection area into a number of grid points that intersect horizontally and vertically, and then obtains the The location information of the touch point. In terms of capacitance grid structure, capacitive touch screens are divided into self-capacitance touch screens and mutual-capacitance touch screens.

For the mutual capacitance touch screen, for the general structure, its principle is shown in Figure 1. The capacitance grid is composed of a vertical sensing line (sensing line) and a horizontal sensing line (drive line). The intersection of the two lines is the mutual capacitance. If a person's finger is close, the human body can be equivalent to a potential, which will attract a part of the electric field lines between the mutual capacitances, which is equivalent to the reduction of the mutual capacitance. If the capacitance of each grid point is continuously scanned, it can be obtained Out of the position of human touch. Mutual capacitance can also be fabricated on a plane, as shown in Figure 2,

For the self-capacitance touch screen, as shown in Figure 3, since the human body can be equivalent to a fixed potential, when it is close to a sensing line. The capacitance of the induction line to the ground (the human body can also be regarded as the ground) will increase, that is, its self-capacitance will increase. By continuously scanning the capacitance of each line to the ground (or to a certain fixed potential), the touch coordinates can be obtained, and the position of the human body touch can be obtained. As shown in FIG. 3 , when the X1 and Y2 positions are touched, the capacitance value corresponding to the position will become larger, so that it can be determined that the position is touched.

Because when the capacitive touch technology is implemented on the printed circuit board, it is necessary to prevent the possible interference caused by the back, because the false touch on the back of the printed circuit board may also cause the change of the capacitance. Therefore, traditionally, when a printed circuit board is used to implement touch detection, it can only be designed as single-sided detection to ensure the accuracy of touch detection.

Contents of the invention

The object of the present invention is to provide a printed circuit board-based double-sided touch screen and a method for realizing double-sided touch control, so that both sides of the printed circuit board have touch detection functions at the same time, thereby saving system space and reducing system design costs.

In order to solve the above technical problems, an embodiment of the present invention provides a double-sided touch screen based on a printed circuit board, comprising: two touch surfaces and at least one intermediate layer;

The two touch surfaces are respectively located on the front and back sides of the printed circuit board;

The intermediate layer is arranged between the two touch surfaces;

Wherein, at least one layer of the intermediate layer is connected to a fixed potential.

Embodiments of the present invention also provide a double-sided touch screen based on a printed circuit board, comprising: two touch surfaces;

The two touch surfaces are respectively located on the front and back sides of the printed circuit board;

The thickness of the printed circuit board is greater than a preset threshold.

Embodiments of the present invention also provide a printed circuit board-based method for implementing double-sided touch control, including the following steps:

providing a touch surface on the front side of the printed circuit board;

At least one intermediate layer is arranged in the printed circuit board, wherein at least one layer of the intermediate layer is connected to a fixed potential;

A touch surface is provided on the reverse side of the printed circuit board.

Compared with the prior art, the embodiments of the present invention have an effective touch surface of the printed circuit board, including front and back sides, and at least one intermediate layer connected to a fixed potential is provided between the front and back touch surfaces. Since the intermediate layer is connected with a fixed potential, the interference between the double-sided touch panels can be eliminated, that is, the touch on one side will not affect the touch on the other side, and the single-sided touch can be extended to double-sided touch. The two sides of the printed circuit board have touch detection function at the same time, thereby saving system space and reducing system design cost. Alternatively, by increasing the thickness of the printing plate and reducing the mutual interference between the front and back touch surfaces, double-sided touch can also be realized, saving system space and reducing system design costs.

In addition, the fixed potential is ground or a fixed power supply. In other words, it is simple and easy to eliminate the interference between the double-sided touch screens by grounding the middle layer or connecting it to a fixed power supply.

In addition, multiple layers of intermediate layers may be arranged between the two touch surfaces, which further ensures the elimination of interference between the double-sided touch screens.

In addition, both touch surfaces are self-capacitance mode touch surfaces; or,

The two touch surfaces are mutual capacitance mode touch surfaces; or,

One of the two touch surfaces is a touch surface in a self-capacitance mode, and the other touch surface is a touch surface in a mutual-capacitance mode.

Since the touch surface can be in self-capacitance mode, mutual-capacitance mode, or a mixture of the two, the embodiments of the present invention are not only applicable to self-capacitance touch screens, but also to mutual-inductance capacitive screens, and have a wide range of application scenarios.

Description of drawings

Fig. 1 is a schematic diagram according to the principle of a mutual capacitance touch screen in the prior art;

Fig. 2 is a schematic diagram of the principle of a mutual capacitance touch screen made on a plane according to the prior art;

FIG. 3 is a schematic diagram of the principle of a self-capacitance touch screen according to the prior art;

4 is a schematic structural diagram of a double-sided touch screen based on a printed circuit board according to a first embodiment of the present invention;

5 is a schematic structural diagram of a double-sided touch screen based on a printed circuit board according to a second embodiment of the present invention;

FIG. 6 is a flow chart of a method for implementing double-sided touch control based on a printed circuit board according to a fourth embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, various embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that, in each implementation manner of the present invention, many technical details are provided for readers to better understand the present application. However, even without these technical details and various changes and modifications based on the following implementation modes, the technical solution claimed in each claim of the present application can be realized.

The first embodiment of the present invention relates to a double-sided touch screen based on a printed circuit board. In this embodiment, two touch surfaces and an intermediate layer are included. The two touch surfaces are respectively located on the front and back sides of the printed circuit board, and the middle layer is arranged between the two touch surfaces. Wherein, at least one intermediate layer is connected to a fixed potential.

Specifically, as shown in Figure 4, a touch surface 1 is provided on the upper surface of the printed circuit board, a touch surface 2 is provided on the lower surface of the printed circuit board, and between the touch surface 1 and the touch surface 2 , that is, inside the printed circuit board, there is an intermediate layer. The middle layer is connected to a fixed potential, and the fixed potential can be ground or a fixed power supply, that is, the middle layer is grounded or connected to a fixed power supply, which is simple to implement.

In this embodiment, touch surface 1 and touch surface 2 can both be mutual capacitance mode touch surfaces, or both can be self-capacitance mode touch surfaces; or, one touch surface in touch surface 1 and touch surface 2 is a self-capacitance mode The touch surface, and the other touch surface is a mutual capacitance mode touch surface.

Those skilled in the art can understand that although in this embodiment, a touch surface is also provided on the back of the printed circuit board, since an intermediate layer connected to a fixed potential is provided between the front and back touch surfaces, therefore, Touching the front touch surface does not interfere with the back touch surface. Similarly, touching the touch surface on the back does not interfere with the touch surface on the front. That is to say, the touch on one side will not affect the touch on the other side, extending single-side touch to double-side touch. The two sides of the printed circuit board have touch detection function at the same time, thereby saving system space and reducing system design cost.

Moreover, the touch surface in this embodiment can be in self-capacitance mode, mutual capacitance mode, or a mixture of the two, so this embodiment is not only suitable for self-capacitance touch screens, but also for mutual capacitance touch screens. application scenarios.

In addition, it is worth mentioning that, in order to highlight the innovative part of the present invention, this embodiment does not introduce technologies that are not closely related to solving the technical problems proposed by the present invention, but this does not mean that there is no Other devices exist.

The second embodiment of the present invention relates to a double-sided touch screen based on a printed circuit board. The second embodiment is substantially the same as the first embodiment, the main difference being that: in the first embodiment, an intermediate layer is provided between the two touch surfaces. In the second embodiment of the present invention, multiple layers of intermediate layers (for example, two layers of intermediate layers) are provided between the two touch surfaces, as shown in FIG. 5 . The multi-layer intermediate layers in this embodiment are all connected to a fixed potential, for example, the multi-layer intermediate layers are all grounded, or connected to a fixed power supply.

By arranging multiple intermediate layers between the two touch surfaces, the effect of eliminating interference between the double-sided touch screens can be further ensured.

In addition, those skilled in the art can understand that in the case of multiple layers of intermediate layers between the two touch surfaces, only one intermediate layer needs to be connected to a fixed potential to eliminate interference between double-sided touch screens. Therefore, in practical applications, among the multi-layer intermediate layers (such as 3 intermediate layers) between two touch surfaces, only one or two intermediate layers may be connected to a fixed potential, instead of all intermediate layers being connected to a fixed potential. potential. Therefore, the implementation manner of the present invention can be realized flexibly and changeably.

The third embodiment of the present invention relates to a double-sided touch screen based on a printed circuit board. The double-sided touch screen in this embodiment includes two touch surfaces, and the two touch surfaces are respectively located on the front and back sides of the printed circuit board. Wherein, the thickness of the printed circuit board is greater than a preset threshold, for example, the thickness of the printed circuit board is greater than 1.6 mm.

Since the mutual interference between the front and back touch surfaces can also be reduced by increasing the thickness of the printing plate, the double-sided touch screen of this embodiment can also realize double-sided touch, saving system space and reducing system design costs.

In addition, the two touch surfaces in this embodiment can both be self-capacitance mode touch surfaces, or both can be mutual-capacitance mode touch surfaces; or, one of the two touch surfaces is a self-capacitance mode touch surface, and the other One touch surface is a mutual capacitance mode touch surface. This makes this embodiment not only applicable to self-capacitance touch screens, but also applicable to mutual-inductance capacitive touch screens, and has a wide range of application scenarios.

The fourth embodiment of the present invention relates to a method for implementing double-sided touch control based on a printed circuit board, and the specific process is shown in FIG. 6 .

In step 610, a touch surface is provided on the front side of the printed circuit board.

In step 620, at least one intermediate layer is provided in the printed circuit board, wherein at least one intermediate layer is connected to a fixed potential, and the fixed potential is ground or a fixed power supply. For example, one or more intermediate layers are arranged in the printed circuit board, and at least one intermediate layer is grounded or fixed to a power supply. Of course, it is also possible to provide multiple layers of intermediate layers that are all grounded or have fixed power supplies.

In step 630, another touch surface is provided on the reverse side of the printed circuit board.

Both touch surfaces of this embodiment are self-capacitance mode touch surfaces; or, both touch surfaces are mutual-capacitance mode touch surfaces; or, one touch surface in the two touch surfaces is a self-capacitance mode touch surface, and the other The touch surface is a mutual capacitance mode touch surface.

It is not difficult to find that this embodiment is a method example corresponding to the first or second embodiment, and this embodiment can be implemented in cooperation with the first or second embodiment. The relevant technical details mentioned in the first or second implementation manner are still valid in this implementation manner, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment mode can also be applied in the first or second embodiment mode.

Those of ordinary skill in the art can understand that the above-mentioned embodiments are specific examples for realizing the present invention, and in practical applications, various changes can be made to it in form and details without departing from the spirit and spirit of the present invention. scope.

Claims (12)

1. A double-sided touch screen based on a printed circuit board, characterized in that, comprising: two touch surfaces and at least one intermediate layer; The two touch surfaces are respectively located on the front and back sides of the printed circuit board; The intermediate layer is arranged between the two touch surfaces; Wherein, at least one layer of the intermediate layer is connected to a fixed potential. 2. The double-sided touch screen based on printed circuit board according to claim 1, characterized in that, The fixed potential is ground or a fixed power supply. 3. The double-sided touch screen based on printed circuit board according to claim 1, characterized in that, At least two intermediate layers are arranged between the two touch surfaces. 4. The double-sided touch screen based on printed circuit board according to claim 3, characterized in that, The intermediate layers are all connected to a fixed potential. 5. The double-sided touch screen based on a printed circuit board according to any one of claims 1 to 4, wherein the two touch surfaces are both self-capacitance mode touch surfaces; or, The two touch surfaces are mutual capacitance mode touch surfaces; or, One of the two touch surfaces is a touch surface in a self-capacitance mode, and the other touch surface is a touch surface in a mutual-capacitance mode. 6. A double-sided touch screen based on a printed circuit board, characterized in that it comprises: two touch surfaces; The two touch surfaces are respectively located on the front and back sides of the printed circuit board; The thickness of the printed circuit board is greater than a preset threshold. 7. The double-sided touch screen based on printed circuit board according to claim 6, characterized in that, The preset threshold is 1.6mm. 8. The double-sided touch screen based on a printed circuit board according to claim 6, wherein the two touch surfaces are both self-capacitance mode touch surfaces; or, The two touch surfaces are mutual capacitance mode touch surfaces; or, One of the two touch surfaces is a touch surface in a self-capacitance mode, and the other touch surface is a touch surface in a mutual-capacitance mode. 9. A method for implementing double-sided touch control based on a printed circuit board, comprising the following steps: providing a touch surface on the front side of the printed circuit board; At least one intermediate layer is arranged in the printed circuit board, wherein at least one layer of the intermediate layer is connected to a fixed potential; A touch surface is provided on the reverse side of the printed circuit board. 10. The method for implementing double-sided touch control based on a printed circuit board according to claim 9, characterized in that, The fixed potential is ground or a fixed power supply. 11. The method for implementing double-sided touch control based on a printed circuit board according to claim 9, characterized in that, At least two intermediate layers are arranged between the two touch surfaces. 12. The method for implementing double-sided touch control based on a printed circuit board according to any one of claims 9 to 11, wherein the two touch surfaces are both self-capacitance mode touch surfaces; or, The two touch surfaces are mutual capacitance mode touch surfaces; or, One of the two touch surfaces is a touch surface in a self-capacitance mode, and the other touch surface is a touch surface in a mutual-capacitance mode.