Optical touch screen and display device

An optical touch screen and a display device are disclosed. The optical touch screen (200) comprises an optical touch panel (210) and a first sensor (220) and a second sensor (230). The optical touch panel (210) comprises a first optical transmission channel (211) and a second optical transmission channel (212) which are intersected with each other. The first sensor (220) is disposed on at least one end of the first optical transmission channel (211) and configured to receive light emitted by the first optical transmission channel (211). The second sensor (230) is disposed on at least one end of the second optical transmission channel (212) and configured to receive light emitted by the second optical transmission channel (212). The optical touch screen and the display device can improve the positioning accuracy of the touch position.

TECHNICAL FIELD

At least one embodiment of the present invention provides an optical touch screen and a display device.

BACKGROUND

With the widespread application of the touch technology and the display technology, more and more people have access to touch screens. Touch screens have many advantages such as easy communication. Users can operate a computer only by using a finger to gently touch icons or text displayed on display screens of computers, and hence human-computer interaction can become more straightforward. Thus, the touch technology greatly facilitates the interactive dialogue between the user and the display screen.

In general, a touch screen is an input device for replacing a keyboard and a mouse. The input device mainly comprises a touch panel attached to a monitor, a controller, a device driver and applications. The touch panel is formed by an indium tin oxide (ITO) glass sheet or an ITO film which is specially processed and configured to sense signals inputted by users. When the surface of the touch panel is touched by a hand or a touch pen, a position identification sensor senses the touch position on the touch panel. As the hand or the touch pen directly contacts the touch panel, fingerprints are left on the surface of the touch panel or scratches are produced, and hence the service life of the display screen can be disadvantageously affected. Moreover, in some special applications, e.g., the public places such as stations, airports and shopping malls, where large-size displays are used, the display cannot be directly contacted in a short distance, and hence the application of the touch screen can be limitative.

A technology as learned by the inventors provides an optical touch screen capable of avoiding the direct contact of a display and controlling the display in a long distance. As illustrated inFIG. 1, the optical touch screen100comprises an optical touch panel110and two sensors120and130, the optical touch panel110comprises an infrared phosphor material capable of emitting light when exposed to the infrared light; and the two sensors120and130are respectively disposed at different corners of the optical touch panel110. When light is emitted from areas irradiated by the infrared light on the optical touch panel110, the two sensors120and130receive the emitted light respectively, and the luminous position is detected and positioned by triangulation.

SUMMARY

Embodiments of the present invention provide an optical touch screen and a display device which can improve the positioning accuracy of the touch position.

At least one embodiment of the present invention provides an optical touch screen, which comprises an optical touch panel, a first sensor and a second sensor. The optical touch panel comprises a first optical transmission channel and a second optical transmission channel which are intersected with each other. The first sensor is disposed on at least one end of the first optical transmission channel and configured to receive light emitted by the first optical transmission channel. The second sensor is disposed on at least one end of the second optical transmission channel and configured to receive light emitted by the second optical transmission channel.

At least another embodiment of the present invention further provides a display device, which comprises the optical touch screen.

Reference numerals of the accompanying drawings:

DETAILED DESCRIPTION

For more clear understanding of the objectives, technical proposals and advantages of the embodiments of the present invention, clear and complete description will be given below to the technical proposals of the embodiments of the present invention with reference to the accompanying drawings of the embodiments of the present invention. It will be obvious to those skilled in the art that the preferred embodiments are only partial embodiments of the present invention but not all the embodiments. All the other embodiments obtained by those skilled in the art without creative efforts on the basis of the embodiments of the present invention illustrated shall fall within the scope of protection of the present invention.

Unless otherwise specified, the technical terms or scientific terms used in the present invention have normal meanings understood by those skilled in the art. The words “first”, “second” and the like used in the present invention do not indicate the sequence, the number or the importance but are only used for distinguishing different components. Similarly, the words “a”, “an”, “the” and the like also do not indicate the number but only indicate at least one. The word “comprise”, “include” or the like only indicates that an element or a component before the word contains elements or components listed after the word and equivalents thereof, not excluding other elements or components. The words “connection”, “connected” and the like are not limited to physical or mechanical connection but may include electrical connection, either directly or indirectly. The words “on”, “beneath”, “left”, “right” and the like only indicate the relative position relationship which is correspondingly changed when the absolute position of a described object is changed.

The inventors note that the optical touch screen as shown inFIG. 1determining the position of a luminous point by triangulation, the positions on the display plane and the measured angles are not in a linear relationship, and hence the positioning accuracy of the touch position can be disadvantageously affected.

FIG. 2is a schematic structural view of an optical touch screen200provided by an embodiment of the present invention. The optical touch screen200provided by the embodiment of the present invention comprises an optical touch panel210which is provided with first optical transmission channels211and second optical transmission channels212. The optical touch screen200further comprises first sensors220and second sensors230. The first sensors220are disposed on at least one end of the first optical transmission channels211and configured to receive light emitted by the first optical transmission channels211. The second sensors230are disposed on at least one end of the second optical transmission channels212and configured to receive light emitted by the second optical transmission channels212. The first sensors220and the second sensors230may be disposed on the outside of the optical touch panel210or may be disposed on the optical touch panel210. In addition, the first sensors220and the second sensors230may be disposed at one end or two ends of corresponding optical transmission channels thereof. In addition, in the embodiment shown inFIG. 8, one first sensor is disposed on each end of each first optical transmission channel and one second sensor is disposed on each end of each second optical transmission channel. As illustrated inFIG. 2, the first optical transmission channels211and the second optical transmission channels212are intersected with each other, and for instance, may be orthogonal to each other. The first optical transmission channels211and the second optical transmission channels212may also be not orthogonal to each other as required. Moreover, as illustrated inFIG. 2, the optical touch panel210comprises a plurality of first optical transmission channels211, a plurality of second optical transmission channels212, a plurality of first sensors220and a plurality of second sensors230. The plurality of first sensors220are in one-to-one correspondence with the plurality of first optical transmission channels211and the plurality of second sensors230are in one-to-one correspondence with the plurality of second optical transmission channels212. The first sensors220and the second sensors230may be optical sensors configured to convert optical signals into electrical signals, and for instance, may be photodiodes or infrared sensors.

Each of the intersection points between the first optical transmission channels211and the second optical transmission channels212may be taken as a luminous position, which is equivalent to form a rectangular coordinate system on the touch panel. After a position on the optical touch screen200is irradiated by light, light emitted from the position can be emitted along the first optical transmission channel(s)211and the second optical transmission channel(s)212at the same time, and optical signals are respectively detected by the first sensor(s)220and the second sensor(s)230, and hence the coordinate of the luminous position can be determined. Thus, the positions on the touch panel and the measured coordinate are in a linear relationship, and hence the positioning accuracy of the touch position can be improved.

When the optical touch screen200provided by at least one embodiment of the present invention is applied in an actual product, the first optical transmission channels211and the second optical transmission channels212are closely arranged on the optical touch panel (correspondingly, the first sensors220and the second sensors230are closely arranged and may also be disposed on the circumference of the optical touch panel), and orthogonal points of the first optical transmission channels211and the second optical transmission channels212are very small in size.FIG. 3is a partial enlarged view of an optical touch panel inFIG. 2. The figure is only intended to facilitate the understanding of readers but not intended to limit the embodiments of the present invention. When a light source irradiates the optical touch panel210, the center of an illuminated area of the optical touch panel210just falls on a certain orthogonal point or a plurality of orthogonal points or is deviated from the orthogonal point. But in either case, the illuminated area on the optical touch panel will cover the specific orthogonal point. The first optical transmission channels211and the second optical transmission channels212have the function of concentrating and guiding light. Thus, the light emitted from the orthogonal point is propagated along the first optical transmission channel(s)211and the second optical transmission channel(s)212at the same time. Finally, optical signals are respectively detected by the first sensor220and the second sensor230corresponding to the channels, and hence the coordinate of the luminous position can be determined.

Of course, the propagation path of light in the optical touch panel is not limited to the two paths. For the convenience of description, as illustrated inFIG. 6, the first optical transmission channels211are disposed in the X direction, and the horizontally rightward direction in the figure is the main X direction; the second optical transmission channels212are disposed in the Y direction, and the vertically upward direction in the figure is the main Y direction; and any orthogonal point between a first optical transmission channel211and a second optical transmission channel212can be set as O point. The propagation path of light is mainly divided into four optical paths which are respectively indicated with □, □, □ and □ inFIG. 6, wherein □ refers to the optical transmission channel in the main Y direction; □ refers to the optical transmission channel in the main X direction; □ refers to the optical transmission channel in the secondary X direction; and □ refers to the optical transmission channel in the non-detection direction.

When any luminous point O is excited, light emitted after excitation will be propagated along all directions on the circumference, most of the light is propagated along the main directions of the optical transmission channels, e.g., the optical propagation paths □ and □, so that light in the X and Y directions is received by the sensors; and in the secondary direction of the optical transmission channel, e.g., the optical path □, light is reflected (including total reflection) and propagated in the transmission channel and finally received by the sensor. In other directions, e.g., the optical path □, light is mainly refracted and propagated; the propagation path is relatively long and the optical loss is relatively large; and finally, the light may not be detected by any sensor. However, the light in the optical path □ may finally enter a specific sensor and be detected. But in this case, the light intensity of the optical transmission channel in the non-detection direction is much smaller than the light intensity of the main optical transmission channel of the luminous point (the light intensity of the main optical transmission channel is the sum of the light intensity of the optical transmission channel in the primary direction and the secondary direction).

In order to prevent the light in the non-detection direction (e.g., the optical path □) from affecting the determination of the luminous position, for instance, a light intensity threshold may be set for the sensor, and hence the interference of the non-detection direction can be eliminated. That is to say, a first light intensity threshold is set for the first sensor220and used for comparison with the light intensity of the first sensor220, and a second light intensity threshold is set for the second sensor230and used for comparison with the light intensity of the second sensor230.

It should be understood that, after the first sensor220and the second sensor230detect the optical signal, the light intensity of the optical signal may be determined and processed by, for instance, a central processing unit (CPU) (one example of a controller), and the position of the luminous point is determined by calculation. For instance, when the CPU determines that the light intensity of the first sensor220is greater than or equal to the first light intensity threshold, the position of the luminous point in the Y direction is determined by calculation; when the light intensity of the first sensor220is less than the first light intensity threshold, further calculation is not conducted; when the CPU determines that the light intensity of the second sensor230is greater than or equal to the second light intensity threshold, the position of the luminous point in the X direction is determined by calculation; and when the light intensity of the second sensor230is less than the second light intensity threshold, further calculation is not conducted.

In summary, when the CPU determines that the light intensity (e.g., the light intensity of the transmission channels in the X and Y directions) reaches the specified light intensity threshold, the coordinate of the luminous position is determined by calculation; and when the CPU determines that the light intensity (e.g., the light intensity in the non-detection direction) does not reach the specified light intensity threshold, further calculation is not conducted, so that the interference of ambient light (e.g., the light in the non-detection direction) can be effectively eliminated, and hence the luminous position can be accurately calculated.

The light source has various types, and different types of light sources require different light intensity thresholds. In addition, different products have different applications. Thus, the specific value range of the first light intensity threshold and the second light intensity threshold should be elected according to actual applications. No specific limitation will be given here.

The optical touch panel110inFIG. 1adopts an infrared phosphor material to achieve the long-distance control of the display. The material is excited by an invisible infrared laser. But in the external environment, a large quantity of objects, particularly high-temperature objects, can emit infrared light. Moreover, the infrared light has no visibility. Thus, the error touch of the optical touch panel110tends to occur, which is not friendly to actual application. At least one embodiment of the present invention adopts up-conversion luminescent materials to achieve the long-distance control of the display. The up-conversion luminescent material can be excited by visible light. Moreover, the visible light not only can be easily acquired (for instance, by a commonly used laser pointer) in an actual application but also has visibility. Thus, the error touch of the optical touch panel210can be avoided.

The first optical transmission channel211and the second optical transmission channel212may be formed by the up-conversion luminescent material via, for instance, an etching process or other patterning processes, and a transparent substrate is adopted as a basic substrate for the up-conversion luminescent material.

The light-emitting principle of the up-conversion luminescent material is Anti-Stokes rule, namely light with long wavelength excites light with short wavelength. For instance, infrared light excites visible light; red light excites yellow light; or visible light excites ultraviolet light. The up-conversion luminescence process of the material generally may occur in compounds doped with rare earth ions, which mainly include fluorides, oxides, sulfur-containing compounds, fluorine oxide, halide or the like or combinations thereof. Currently, the up-conversion luminescent material has the function of absorbing light with the wavelength of 600 to 1,100 nm and producing visible light such as red light, green light or blue light by up-conversion excitation.

According to the light-emitting principle of the up-conversion luminescent material, the touch light source in at least one embodiment of the present invention adopts visible light. The up-conversion luminescent material stated above will emit visible light or invisible light when exposed to visible light. The wavelength of visible light capable of being absorbed by the up-conversion luminescent material is determined by the type of the material. Herein, the optional proposal of the embodiment of the present invention is that: the up-conversion luminescent material absorbs orange light with the wavelength of 618 nm. After the up-conversion luminescent material absorbs the orange light with the wavelength of 618 nm, blue light with the wavelength of 487 nm can be excited by up-conversion.

As for the optical touch panel210, as illustrated inFIG. 4, in another embodiment of the present invention, the optical touch panel210may include a first substrate, for instance, a first transparent substrate213. The first transparent substrate213is provided with an up-conversion luminescent material thereon, and a first optical transmission channel211and a second optical transmission channel (not shown in the figure) are formed on the first transparent substrate213by, for instance, an etching process or other patterning processes.

As illustrated inFIG. 5, in still another embodiment of the present invention, the optical touch panel210may also have a structure similar to a sandwich. The upper layer and the lower layer are respectively a second substrate and a first substrate, for instance, a second transparent substrate214and a first transparent substrate213. The intermediate layer is provided with the up-conversion luminescent material. First optical transmission channels (not shown inFIG. 5) and second optical transmission channels212are formed on the first transparent substrate213by the up-conversion luminescent material in the intermediate layer via, for instance, an etching process or other patterning processes. The sandwich structure can have the function of protecting the up-conversion luminescent material and prevent the up-conversion luminescent material from contacting the external environment.

In at least one embodiment of the present invention, both the first transparent substrate213and the second transparent substrate214may comprise glass or may comprise resin, or one comprises glass and the other comprises resin. The space, beside the first optical transmission channels211and the second optical transmission channels212, between the first transparent substrate213and the second transparent substrate214, for instance, may also be filled with a protective layer which is configured to protect the up-conversion luminescent material and prevent the up-conversion luminescent materials from being damaged.

In at least one embodiment of the present invention, the protective layer, for instance, may be of vacuum and may also be of inactive gas, e.g., inert gas (helium, neon, argon, krypton, xenon and radon) and nitrogen which do not react with the up-conversion luminescent materials.

The first transparent substrate213and the second transparent substrate214do not react with visible light. Thus, the visible light can directly run through the transparent substrates and be incident into the up-conversion luminescent materials, which will not affect the touch of the optical touch panel210.

At least one embodiment of the present invention further provides a display device, which, as illustrated inFIG. 7, comprises a display body340and an optical touch screen300disposed on a display side of the display body340. The optical touch screen300comprises an optical touch panel310, at least one first sensor320and at least one second sensor330. The optical touch panel310is mounted in the display body340. The at least one first sensor320and the at least one second sensor330are, for instance, interposed between the display body340and the optical touch panel310. The optical touch panel310is provided with a plurality of first optical transmission channels311and a plurality of second optical transmission channels312which are, for instance, orthogonal to each other. The at least one first sensor320is disposed at one end of the first optical transmission channel311and configured to receive light emitted by the first optical transmission channel311. The at least one second sensor330is disposed at one end of the second optical transmission channel312and configured to receive light emitted by the second optical transmission channel312.

In the case as shown inFIG. 7, the first optical transmission channels311and the second optical transmission channels312are orthogonal to each other. Each of the intersection points of the first optical transmission channels311and the second optical transmission channels312may be taken as a luminous position, which is equivalent to a rectangular coordinate system on the touch panel. After a specific position on the optical touch panel210is irradiated by light, light emitted from the position may be emitted along the first optical transmission channel(s)311and the second optical transmission channel(s)312at the same time, and optical signals are respectively detected by the first sensor320and the second sensor330, and hence the coordinate of the luminous position can be determined. Thus, the positions on the touch panel and the measured coordinate are in a linear relationship, and hence the positioning accuracy of the touch position can be improved.

The display body340may be a display device of any type, for instance, a liquid crystal display (LCD) device, an organic light-emitting diode (OLED) display device, an inorganic diode display device, a plasma display device and a cathode ray tube (CRT) device.

As the preferred embodiments of the optical touch screen300have been described above in detail, no further description will be given here.

In at least one embodiment of the present invention, the first optical transmission channels311and the second optical transmission channels312comprise an up-conversion luminescent material. When visible laser is emitted to the optical touch panel310by a user through a laser pointer at a position away from the display device, light is incident into the up-conversion material and is converted into visible light or invisible light by excitation; the light is propagated along the transmission channels in the X and Y directions; optical signals are detected by the first sensor320and the second sensor330and hence calculated and processed by, for instance, a CPU; and hence the luminous position of the optical touch panel310can be obtained.

In at least one embodiment of the present invention, the means of one first sensor and one second sensor may be adopted. For instance, the first sensor and the second sensor adopt a sensor with a position identification function.

The foregoing is only the preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any change or replacement easily made by those skilled in the art within the technical scope disclosed by the present invention shall fall within the scope of protection of the present invention. Thus, the scope of protection of the present invention shall be defined by the appended claims.

The application claims priority to the Chinese patent application No. 201310463669.X submitted on Sep. 30, 2013. The disclosure content of the Chinese patent application is incorporated by reference herein as part of the application.