FILTER STRUCTURE OF INFRARED TOUCH MODULE

A filter structure of infrared touch module includes a main body having an upper protrusion section and an extension section. The upper protrusion section and the extension section respectively extend from an upper end and a lower end of the main body in reverse directions. The upper protrusion section extends to upper sides of multiple infrared transmitters and multiple infrared receivers. The main body is positioned in front of the transmission faces of the infrared transmitters and the receiving faces of the infrared receivers to shield the transmission faces and the receiving faces. The extension section extends to a position between a transparent panel and a second circuit board.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an infrared filter structure, and more particularly to a filter structure applied to infrared touch module.

2. Description of the Related Art

Infrared touch technique has the advantages of high transparency, sensitivity to the touch of any material and applicability to large-size display. Therefore, infrared touch technique is widely applied to various displays. An infrared touch display screen has infrared transmitters and infrared receivers correspondingly arranged on opposite sides of the surface of the display screen. The infrared transmitters and infrared receivers form an infrared network densely distributed over the surface of the display screen. In touch, the article (such as a finger) will partially interrupt the infrared network to calculate the touch position.

The infrared touch display screen necessitates an infrared transparent frame to ensure that the infrared receiver units receive the infrared rays without interference of the environmental light. Currently, the infrared transparent frame is generally arranged in two manners. According to the first manner, the side frame of the infrared touch display screen is made of an optical material, which is infrared transparent, while visible light nontransparent. According to the second manner, the side frame is made of a nontransparent material and an infrared filter is packaged on the side frame of the infrared touch display screen. In order to lower cost, currently the second manner is most often adopted. The infrared filter is made of a plastic material to which a dye is added. The infrared filters are generally classified into two types. The first type is high-pass filter, which is transparent to the light with a wavelength larger than 850 nm or 940 nm. The second type is low-pass filter, which is transparent to the light with a wavelength within a range from 925 nm to 955 nm.

FIGS. 1A and 1Bshow the second type of infrared filter. The display screen has a frame body10. A display section11is defined in the frame body10corresponding to a display module12. A transparent panel13is overlaid on the display module12. Two sets of corresponding LED transmitters14and LED receivers15are arranged on the opposite sides of the frame body10. The LED transmitters14and LED receivers15are disposed on a first circuit board16and exposed to upper surface of the transparent panel13. The first circuit board16is electrically connected with a second circuit board17. The first circuit board16is an LED circuit board, while the second circuit board17is a motherboard. A filter18is packaged on the frame body10. The filter18has an upper protrusion section181and an extension section182. The extension section182downward extends from a rear end of the upper protrusion section181and has a free end1821. The upper protrusion section181extends into the frame body10and is positioned on upper side of the LED transmitters14and LED receivers15. The extension section182shields the transmission faces of the LED transmitters14and the receiving faces of the LED receivers15from the affection of the environmental light.

The free end1821of the extension section182is fixedly adhered to the upper surface of the transparent panel13via a first adhesive bar191. The lower surface of the transparent panel13is affixed to the second circuit board17via a second adhesive bar192.

The above arrangement has some shortcomings. For example, the second circuit17is affixed to the transparent panel13by means of adhesion. In the case that it is necessary to detach the frame body10for replacing some components of the infrared touch display screen or repairing the infrared touch display screen, the second circuit board17must be separated from the transparent panel13. Under such circumstance, the circuit or electronic components of the second circuit board17may be damaged. In this case, it will be impossible to reuse the second circuit board17.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a filter structure of infrared touch module. The filter structure has an extension section adhered to the transparent panel, whereby the filter structure is more securely attached to the transparent panel and prevented from displacing or detaching from the transparent panel.

It is a further object of the present invention to provide the above filter structure. The main body of the filter structure is positioned above and in front of the infrared transmitters and the infrared receivers to shield the same. In addition, the extension section of the filter structure extends to a position between the transparent panel and a circuit board. In this case, the circuit board is not directly adhered to the transparent panel. Accordingly, when separating the circuit board from the transparent panel, the circuit board is prevented from being damaged.

It is still a further object of the present invention to provide the above filter structure, in which the extension section has an upper surface adhered to the transparent panel and a lower surface adhered to the circuit board.

It is still a further object of the present invention to provide the above filter structure, which is applied to an infrared touch module. When separating the circuit board from the transparent panel, the circuit board is prevented from being damaged. Therefore, the infrared touch module is reworkable.

To achieve the above and other objects, the filter structure of infrared touch module of the present invention is applied to a side frame of the infrared touch module. The side frame has multiple infrared transmitters and multiple infrared receivers. The infrared transmitters and infrared receivers are disposed on a first circuit board. Each infrared transmitter has a transmission face. Each infrared receiver has a receiving face. The first circuit board is connected with a second circuit board. The side frame defines a window therein. A transparent panel is positioned under the side frame in alignment with the window. The transparent panel has a transparent section exposed to the window, a concealed section around the transparent section corresponding to the second circuit board and an outer periphery. The filter structure includes a main body having an upper protrusion section and an extension section. The upper protrusion section and the extension section respectively angularly extend from an upper end and a lower end of the main body in reverse directions. The upper protrusion section extends to upper sides of the infrared transmitters and infrared receivers. The extension section extends to a position between the transparent panel and the second circuit board.

In the above filter structure of the infrared touch module, the extension section has an upper surface corresponding to the concealed section of the transparent panel and a lower surface corresponding to the second circuit board. A first adhesive layer is disposed between the upper surface of the extension section and the concealed section of the transparent panel. A second adhesive layer is disposed between the lower surface of the extension section and the second circuit board.

In the above filter structure of the infrared touch module, the upper protrusion section has a protrusion end and the extension section has an extension end. The upper protrusion section and the extension section are positioned on different levels.

In the above filter structure of the infrared touch module, a gap is defined between the outer periphery of the transparent panel and the main body of the filter structure.

In the above filter structure of the infrared touch module, the main body of the filter structure is formed with a recess on upper side of the extension section. The outer periphery of the transparent panel is received in the recess.

According to the above arrangement, the circuit board is not directly adhered to the transparent panel. Therefore, when separating the circuit board from the transparent panel, the circuit board is prevented from being damaged. Moreover, the filter structure is more securely attached to the transparent panel and prevented from displacing or detaching from the transparent panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments of the present invention will be described hereinafter with reference to the drawings, wherein the same components are denoted with the same reference numerals.

Please refer toFIGS. 2,3A and3B.FIG. 2is a top view of the infrared touch module of the present invention.FIG. 3Ais a sectional view of the first embodiment of the filter structure of the present invention.FIG. 3Bis a sectional view showing that the first embodiment of the filter structure of the present invention is applied to an infrared touch module.

As shown inFIG. 2, a side frame20defines a window21therein. Two sets of corresponding infrared transmitters22and infrared receivers23are arranged on the opposite sides of the frame body20. The infrared transmitters22and infrared receivers23are disposed on a first circuit board24(as shown inFIG. 3B). The first circuit board24is electrically connected with a second circuit board25(as shown inFIG. 3B). The first circuit board24is an LED circuit board, while the second circuit board25is a motherboard. Each infrared transmitter22has a transmission face221facing a receiving face231of each infrared receiver23. A transparent panel26is positioned under the side frame20in alignment with the window21. The infrared transmitters22and infrared receivers23are exposed to an upper surface of the transparent panel26to form an infrared sensing matrix above the transparent panel26.

As shown inFIGS. 3A and 3B, the transparent panel26has a transparent section261exposed to the window21. A display module27is positioned under the transparent section26. The transparent panel26further has a concealed section262around the transparent section26and concealed by the side frame29corresponding to the second circuit board25. The transparent panel26further has an outer periphery263. In this embodiment, the transparent panel26is made of such as transparent silica glass, polymethylmethacrylate (PMMA), polycarbonate (PC) or polyethylene terephthalate (PET) for protecting the display module27. The transparent panel26also provides a touch plane, (that is, the upper surface of the transparent panel26), for a user to touch with a finger or a stylus. The light emitted from the display module27(such as an LCD display module) can pass through the transparent panel26to present an image to a user.

The filter structure30of the present invention has an upper protrusion section32and an extension section33. The upper protrusion section32and the extension section33respectively angularly extend from an upper end and a lower end of the main body31in reverse directions. The upper protrusion section32extends to upper sides of the infrared transmitters22and infrared receivers23. The extension section33extends to a position between the transparent panel26and the second circuit board25. The upper protrusion section32and the extension section33are positioned on different levels. The upper protrusion section32has a protrusion end321and the extension section33has an extension end331. The main body31is positioned in front of the transmission faces221of the infrared transmitters22and the receiving faces231of the infrared receivers15to shield the transmission faces221and the receiving faces231. A gap35is defined between the outer periphery263of the transparent panel26and the main body31.

The extension section33between the transparent panel26and the second circuit board25has an upper surface332and a lower surface333. The upper surface332corresponds to the concealed section262of the transparent panel26, while the lower surface333corresponds to the second circuit board25.

A first adhesive layer28is disposed between the upper surface332of the extension section33and the concealed section262of the transparent panel26. The first adhesive layer28has adhesion on both faces, whereby the extension section33is adhered under the concealed section262of the transparent panel26. A second adhesive layer29is disposed between the lower surface333of the extension section33and the second circuit board25. The second adhesive layer29has adhesion on both faces, whereby the extension section33is affixed to upper side of the second circuit board25. The first and second adhesive layers28,29are such as double-faced adhesive tape or the like.

Please now refer toFIG. 3C, which is a sectional view showing the first manner in which the first embodiment of the present invention is detached. In the case that some components of the infrared touch module are damaged and need to be repaired, the side frame20is first detached and removed. Then, a slender and flat tool is inserted into the gap35between the outer periphery263of the transparent panel26and the main body31to detach the transparent panel26from the second circuit board25. At this time, the transparent panel26may be directly separated from the upper side of the first adhesive layer28. Alternatively, in another manner as shown inFIGS. 4A and 4B, the junction between the main body31and the extension section33is formed with a split36. In the case that some components of the infrared touch module are damaged and need to be repaired, the side frame20is first detached and removed. Thereafter, a slender and flat tool is inserted into the gap35between the outer periphery263of the transparent panel26and the main body31to the bottom to forcedly break the filter structure30. The force is concentrated on the split36so that the extension section33will break at the split36to separate from the main body32. In both the above detaching manners, the second circuit25is prevented from being damaged. Therefore, the second circuit board25can keep complete. After the reparation is finished, the filter structure30is replaced with a new one to recover the infrared touch module.

Please now refer toFIGS. 5A and 5B. In another embodiment, the main body31of the filter structure30is formed with a recess34on upper side of the extension section33. In this case, the outer periphery263of the transparent panel26is received in the recess34.

In conclusion, the filter structure of the present invention is positioned above and in front of the infrared transmitters and the infrared receivers to shield the same. The filter structure has an extension section extending between the transparent panel and the circuit board, whereby the circuit board is not directly adhered to the transparent panel. Accordingly, when separating the circuit board from the transparent panel, the circuit board is prevented from being damaged. In this case, the infrared touch module is repairable and reworkable.

The present invention has been described with the above embodiments thereof and it is understood that many changes and modifications in the above embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.