WO2014059841A1

WO2014059841A1 - Optical touch screen

Info

Publication number: WO2014059841A1
Application number: PCT/CN2013/083365
Authority: WO
Inventors: 刘川; 吴振宇; 刘新斌
Original assignee: 北京汇冠新技术股份有限公司
Priority date: 2012-10-19
Filing date: 2013-09-12
Publication date: 2014-04-24
Also published as: CN102955620A

Abstract

An optical touch screen comprises a frame (101), at least one optical sensor (102), at least one light source and a reflective bar (103). The frame (101) has a first side, a second side, a third side and a fourth side which are sequentially connected end to end. The at least one optical sensor (102) is located on at least one end of the first side, the at least one light source is located on at least one end of the first side, and the reflective bar (103) is located at an inner side of the third side, wherein the reflective bar (103) is provided with a light regulation part for locally regulating the intensity of reflected light of the reflective bar (103). By using the optical touch screen, the optical sensor (102) can receive uniform light intensity, which helps to improve the accuracy of determination of a touch.

Description

Optical touch screen technical field

The present invention relates to optical touches. Background technique

Optical touch screens are widely used due to their high precision and support for multi-touch. Fig. 1 is a block diagram showing the structure of an optical touch panel in the prior art. As shown in FIG. 1, the optical contact has a bezel 101, and an optical sensor 102 and a light source (not shown) are mounted at both ends of the top of the bezel 101, and the light emitted from the light source is reflected by the reflection bar around the bezel 101, the top In the optical sensor 102 at both ends. The dense light emitted by the light source forms a light net in the touch area. When a point on the optical touch screen is touched, the emitted light and the received light at the point form an angle, and the optical sensor 102 at both ends and the straight line between the two light and the two optical sensors 102 form an angle. In this way, the exact coordinates of the point are recorded by the controller of the touch screen, thereby calculating the coordinates of the touched point and realizing the touch positioning.

In an optical touch screen, light from a light source at the top ends of the bezel 101 of the touch screen can be reflected by reflective strips on a total of three borders of the side frames of the touch screen and the side frames on the left and right sides. Since the light source =1 is facing the middle of the lower frame, the light reflected by the reflection bar near the middle of the lower frame is stronger, and the reflection bar located near the end of the lower frame and the side frames on the left and right sides is reflected. The light is weak, which causes a difference in the intensity of the emitted light received by the optical sensor, so that the optical sensor cannot receive uniform light.

In the prior art, the intensity of the illuminating light of the light source can be adjusted by adjusting the magnitude of the voltage or current of the light source, thereby integrally adjusting the intensity of the light reflected by the reflective strip. However, adjusting the illuminating light intensity of the light source by the above method cannot locally adjust the intensity of the light reflected by the reflective strip at different positions, and therefore, does not enable the reflective strip to reflect uniform light, and thus can not cause the optical sensor to receive To even light, this may affect the accurate judgment of the touch screen on the position of the touch object. Summary of the invention

In view of the above problems in the prior art, the present invention provides an optical touch for causing an optical sensor of an optical touch screen to obtain uniform reflected light, thereby accurately performing touch positioning.

According to an aspect of the present invention, an optical touch screen includes a bezel, at least one optical sensor, at least one light source, and a reflective strip, the bezel having a first side, a second side, and a third end that are connected end to end in sequence The side and the fourth side, the at least one optical sensor is located at at least one end of the first side, the at least one light source is located at at least one end of the first side, and the reflective strip is located at least inside the third side The light reflecting member is provided with a dimming member for locally adjusting the intensity of the reflected light of the reflective strip.

Preferably, the light strip is a retroreflective strip.

Preferably, the dimming member is a mesh or grid that is non-uniformly distributed over the strip, the mesh or mesh being used to absorb light or to illuminate the light.

Preferably, the dots or grids are made of a plastic transparent material.

Preferably, the dots or grids at both ends of the reflective strip on the third side are sparse than the dots or mesh in the middle.

Preferably, the strip is also located inside the second side and/or the fourth side.

Preferably, the dots or grids of the reflective strips on the second side and/or the fourth side that are adjacent to the optical sensor are sparse than the dots or grids that are remote from the optical sensor.

Preferably, the at least one light source is an infrared light source or a laser light source, and the at least one optical sensor is an infrared camera or a laser sensor.

Preferably, the optical sensor is fixed to the light source at least one end of the first side.

With the optical touch screen of the present invention, since the strip is provided with a dimming member for locally adjusting the intensity of the reflected light of the reflective strip, the intensity of the reflected light at different positions can be adjusted, so that the strip can be The intensity of the reflected light is locally controlled, so that the reflective strip uniformly reflects the light emitted by the light source, and the optical sensor can receive a uniform light intensity, which is advantageous for improving the accuracy of the touch determination. DRAWINGS

Figure 1 is a structural view of an optical touch in the prior art;

2 is a structural diagram of an optical touch screen according to an embodiment of the present invention;

3 is a partial schematic view of a reflective strip having a grid in accordance with an embodiment of the present invention. detailed description

The technical solutions of the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Fig. 2 shows a structural view of an optical touch according to an embodiment of the present invention. Figure 3 is a partial schematic illustration of a JJ strip with dots in accordance with an embodiment of the present invention.

Referring to Figure 2, an optical touch screen in accordance with an embodiment of the present invention is shown. The optical touch screen includes a bezel 101, at least one optical sensor 102, at least one light source (not shown), and a reflective strip 103. The bezel 101 has a first side, a second side, a third side, and a fourth side that are connected end to end in sequence. The at least one optical sensor is located at at least one end of the first side. The at least one light source is located at at least one end of the first side. The reflective strip 103 is located on the inner side of at least the third side, and a dimming member for locally adjusting the intensity of the reflected light of the reflective strip is disposed on the reflective strip.

When a touch object (for example, a user's finger) touches a point in the touch detection area surrounded by the bezel 101, a part of the light emitted by the light source is blocked. The unblocked light is reflected by the reflective strip 103 on the bezel 101 into the optical sensor, and the blocked light cannot be reflected back to the optical sensor by the reflective strip 103, thereby forming a shadow on the photosensitive chip of the optical sensor. By analyzing the position of the shadow, you can calculate the position of the touch object. In order for the optical sensor to receive the reflected light of the hook and obtain the position of the touch object more accurately, it is necessary to locally control the intensity of the light reflected by the reflective strip 103. According to an embodiment of the present invention, by providing a dimming member on the reflective strip, the dimming member can locally adjust the intensity of the reflected light of the reflective strip, so that it can be reflected as needed The light emitted by the light source is reflected to different degrees at different positions of the strip, so that the optical sensor can receive uniform reflected light.

Typically, the j t strip 103 is a retroreflective strip for retroreflective reflection of light from a source.

According to one embodiment, the dimming member is a dot or grid that is non-uniformly distributed over the reflective strip 103. The dots or grids are used to absorb light or to illuminate the light. Figure 3 is a partial schematic illustration of a strip having a grid in accordance with an embodiment of the present invention. Referring to Figure 3, a partial schematic view of a reflective strip 103 having a grid is shown. This schematic diagram exemplarily shows a grid that is non-uniformly distributed over JiJ strips 103, i.e., grids that may have different densities at different locations on J^Jt strips 103.

Specifically, the reflective strip 103 is located at least on the third side of the bezel 101. The third side is opposite to the first side. Also, dots or grids are distributed on the reflective strip 103, and the dots or grids can be used to absorb light or diffusely reflect light. At a dot or grid-dense location, more light is absorbed or diffusely reflected by the dots or mesh, and therefore, the intensity of light reflected to the optical sensor 102 is small. In the position where the dots are sparse, the light absorbed by the dots is less, and therefore, the intensity of the light reflected to the optical sensor 102 is large. In this way, in order to cause the reflective strip 103 to reflect light of uniform intensity at different positions, the distribution of the dots or grids is non-uniform, so that the strips 103 can be adjusted by distributing different density dots or grids. The intensity of the reflected light.

Preferably, the dots or grids may be made of a plastic transparent material such as PC (polycarbonate) plastic or PMMA (polymethyl methacrylate) plastic to better absorb light emitted by the light source or to conduct light. Diffuse reflection.

In the case where the light source is facing the middle of the third side, since the light reflected by the reflective strip 103 near the middle of the third side is relatively strong, the light reflected by the reflective strip 103 near the end of the third side is weak, Preferably, the dots or meshes of the two ends of the reflective strips 103 on the third side are sparse than the mesh dots or meshes in the middle, so that the light intensity reflected by the strips 103 in the middle of the third side can be reduced more. The intensity of light reflected by the reflective strips 103 at the ends of the third side is reduced to a relatively small extent. Thus, the light intensity reflected by the middle portion and the end portion of the reflective strip 103 on the third side is made as uniform as possible. Further, the reflective strip 103 may also be located inside the second side and/or the fourth side, so that light emitted by the light source in various directions may be reflected. In this case, generally, the portion of the reflective strip 103 that is closer to the optical sensor reflects light, while the portion that is far from the optical sensor reflects light. Therefore, the dots or grids of the reflective strips 103 on the second side and/or the fourth side that are close to the optical sensor are sparse than the dots or meshes away from the optical sensor, such that the second side And/or the strip 103 on the fourth side is capable of uniformly reflecting the light emitted by the light source.

The at least one light source may be an infrared light source, or may be a laser light source or the like. Accordingly, the at least one optical sensor may be an infrared camera or a laser sensor or the like.

In order to be able to accurately calculate the position of the touch object, the optical sensor and the light source may be fixed on at least one end of the first side in an overlapping manner. For example, the optical sensor can be stacked on top of the light source or the light source can be stacked on top of the optical sensor.

With the optical touch panel of the present invention, since the J^Jt strip 103 is provided with a dimming member for locally adjusting the intensity of the reflected light of the reflective strip, the intensity of the reflected light at different positions can be adjusted. In this way, the intensity of the light reflected by the reflective strip 103 can be locally controlled, so that the reflective strip 103 uniformly reflects the light emitted by the light source, so that the optical sensor can receive a uniform light intensity, which is advantageous for improving the accuracy of the touch determination.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope of the present disclosure. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

Rights request

1. An optical touch screen. The optical touch screen includes a frame (101), at least one optical sensor ( ¹⁰² ), at least one light source and a reflective strip (103). The frame (101) has a first side connected end to end, the second side, the third side and the fourth side, the at least one optical sensor (102) is located at at least one end of the first side, the at least one light source is located at at least one end of the first side, the reflective strip (103) is located inside at least the third side, wherein the reflective strip (103) is provided with a light adjustment component for locally adjusting the intensity of the reflected light of the reflective strip.

2. The optical touch screen according to claim 1, wherein the reflective strip (103) is a retroreflective strip.

3. The optical touch screen according to claim 1 or 2, wherein the light-adjusting component is a dot or grid non-uniformly distributed on the strip (103), and the dot or grid is used to absorb light. Or irradiate the light.

4. The optical contact according to claim 3, wherein the dots or grids are made of plastic transparent material.

5. The optical contact according to claim 3, wherein the dots or grids at both ends of the reflective strip (103) located on the third side are sparser than the dots or grids in the middle.

6. The optical touch screen according to claim 3, wherein the reflective strip (103) is also located inside the second side and/or the fourth side.

7. The optical touch screen according to claim 6, wherein the dots or grids of the reflective strips (103) located on the second side and/or the fourth side that are close to the optical sensor (102) are further away from each other. The dots or grids of the optical sensor (102) are sparse.

8. The optical touch screen according to claim 1, wherein the at least one light source is an infrared light source or a laser light source, and the at least one optical sensor (102) is an infrared camera or a laser. 9. The optical touch screen according to claim 1 Touch sensor, wherein the optical sensor (102) is fixed to at least one end of the first side so as to overlap the light source.