CN102760014A - Infrared touch screen - Google Patents

Abstract

The invention discloses an infrared touch screen, which belongs to the technical field of touch screens, and includes a light guide screen, a circuit board, an outer frame, an infrared emission tube, an infrared receiver, etc., and each of the four sides around the light guide screen includes several paraboloids of the same size. Both the infrared emitting tube and the infrared receiver installed on the circuit board are located at the focal point of the paraboloid of the light guide screen. The infrared touch screen can transmit the light perpendicular to and inclined to the duct screen to the infrared receiver after total reflection by two parabolas, so the infrared touch screen can be made very thin without affecting its signal strength.

Description

An infrared touch screen

technical field

The invention relates to a touch screen, in particular to an infrared touch screen.

Background technique

The infrared touch screen uses the dense infrared matrix in the X and Y directions to detect and locate the user's touch, including the light guide screen, circuit board, outer frame, infrared emitting tube and infrared receiver, etc., and the infrared emitting tube and infrared receiver are installed crosswise. Two opposite directions on the highly integrated circuit board form an invisible infrared grating, and the light guide screen is fixed above the infrared emitting tube and the infrared receiver through the outer frame. The control circuit on the circuit board continuously sends pulses to the diode to form an infrared polarization beam grid. When the user touches the light guide screen, the finger will block the two horizontal and vertical infrared rays passing through the position, blocking the beam, so it can be judged The position of the touch point on the screen.

Infrared touch screens are not affected by current, voltage and static electricity, and are suitable for harsh environmental conditions. Therefore, it is generally believed that infrared technology is the ultimate development trend of touch screen products. However, the infrared light reflecting surface of the infrared touch screen on the market is generally flat, such as According to the patent "ON A SUBSTRATE FORMED OR RESTING DISPLAYARRANGEMENT" patent number US8,068,101 B2, the infrared light reflection surface of the light guide screen is a plane at an angle of 45° to the horizontal plane. Such a reflection surface has the following disadvantages:

1. In order to enhance the reflected light of infrared light as much as possible, it is necessary to increase the thickness of the light guide screen, which not only increases the material cost of the light guide screen, but also increases the weight of supporting products (such as mobile phones, computers, etc.);

2. If the thickness of the light guide screen is reduced for aesthetics and economy, the optical path of the infrared touch screen light transmission will be narrowed, resulting in weak light, susceptible to external interference, and affecting the signal at the receiving end.

In view of this, the inventor conducted research on this and developed an infrared touch screen, from which this case arose.

Contents of the invention

The object of the present invention is to provide an infrared touch screen with thin thickness and strong light transmission signal.

In order to achieve the above object, the solution of the present invention is as follows:

An infrared touch screen, including a light guide screen, a circuit board, an outer frame, an infrared emitting tube and an infrared receiver, etc., wherein the infrared emitting tube is installed on two adjacent sides of the circuit board, and the infrared receiver is installed on the circuit board On the other two adjacent sides, the light guide screen is fixed above the infrared emitting tube and the infrared receiver through an outer frame, and each of the four sides around the light guide screen includes several paraboloids of the same size. The included angle of the surface is 45°, and the horizontal cross section of the parabola is parabolic.

Both the infrared emitting tube and the infrared receiver installed on the circuit board are located at the focal point of the paraboloid of the light guide screen.

The number of paraboloids on the four sides of the light guide screen is equal to the number of infrared emitting tubes or infrared receivers on the corresponding sides.

Because the above-mentioned infrared touch screen is located at the focal point of the parabola of the light guide screen, and the parabola is inclined inward by 45°, all the light emitted by the infrared emitter tube and reaching the parabola can be directed to the infrared guide screen horizontally. The parabola on the opposite side, and the parabola on the opposite side gathers all the light received into the focal point, that is, the infrared receiver. Compared with the prior art, which can only transmit the light perpendicular to the light guide screen to the infrared receiver, the present invention can not only transmit the light perpendicular to the light guide screen, but also the light inclined to the guide screen through two parabolic total reflections. It is transmitted to the infrared receiver, so the infrared touch screen can be made very thin without affecting its signal strength.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Instructions attached

FIG. 1 is a schematic structural diagram of an infrared touch screen in this embodiment;

Fig. 2 is a cross-sectional view of the infrared touch screen of the present embodiment;

Fig. 3 is a top view of part of the optical path of the infrared touch screen in this embodiment.

Label description:

light guide screen 1; parabolic surface 11; lower surface 12;

Circuit board 2; infrared emitting tube 3; infrared receiver 4; outer frame 5.

Specific implementation methods :

As shown in Figure 1, an infrared touch screen includes a light guide screen 1, a circuit board 2, an outer frame 5, an infrared emitting tube 3 and an infrared receiver 4, etc., wherein the infrared emitting tube 3 is installed on two of the circuit boards 2 On the adjacent side, the infrared receiver 4 is installed on the other two adjacent sides of the circuit board 2, and the light guide screen 1 is fixed above the infrared emitting tube 3 and the infrared receiver 4 through the outer frame 5, and the light guide screen 1 Each of the surrounding four sides includes several paraboloids 11 of the same size, the angle between the paraboloids 11 and the lower surface 12 of the light guide screen is 45°, and the horizontal cross section of the paraboloids 11 is parabolic.

Both the infrared emitting tube 3 and the infrared receiver 4 mounted on the circuit board 2 are located at the focal point of the paraboloid 11 of the light guide screen 1 .

In this embodiment, the number of paraboloids 11 on the four sides of the light guide screen 1 is equal to the number of infrared emitting tubes 3 or infrared receivers 4 on the corresponding sides.

When the above-mentioned infrared touch screen is working, because the infrared emission tube 3 and the infrared receiver 4 are located at the focus of the paraboloid 11 of the light guide screen 1, all the light emitted by the infrared emission tube 3 and reaching the parabola 11 can be horizontally directed to the infrared touch screen 1 pair The paraboloid 11 on one side, and the paraboloid 11 on the opposite side gathers all the received light into the infrared receiver 4 . Compared with the prior art, which can only transmit the light perpendicular to the light guide screen 1 to the infrared receiver 4, the present invention can not only transmit the light perpendicular to the light guide screen 1, but also the light inclined to the guide screen 1 through two The parabola 11 transmits to the infrared receiver 4 after total reflection, so the infrared touch screen 1 can be made very thin without affecting its signal strength.

The above-mentioned embodiments do not limit the form and style of the product of the present invention, and any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims (3)

1. An infrared touch screen, characterized in that: comprise a light guide screen, a circuit board, an outer frame, an infrared emitting tube and an infrared receiver, wherein the infrared emitting tube is installed on two adjacent edges of the circuit board, and the infrared receiving The device is installed on the other two adjacent sides of the circuit board. The light guide screen is fixed above the infrared emitting tube and the infrared receiver through the outer frame. The four sides around the light guide screen each include several paraboloids of the same size. The paraboloids The included angle with the lower surface of the light guide screen is 45°, and the horizontal cross section of the parabola is parabolic. 2. The infrared touch screen according to claim 1, characterized in that: the infrared emitting tube and the infrared receiver installed on the circuit board are located at the focal point of the paraboloid of the light guide screen. 3. The infrared touch screen according to claim 1, wherein the number of paraboloids on the four sides of the light guide screen is equal to the number of infrared emitting tubes or infrared receivers on the corresponding sides.

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