Optical sense-control system having light filters

An optical sense-control system, for receiving a first light and second light, includes a first optical filter, a second optical filter, and an optical detection module. The transmission of the first light having a majority intensity in a first wave-length band is greater than the transmission of the second light having a majority intensity in a second wave-length band in the first optical filter, the first wave-length band is less than the second wave-length band, and the transmission of the second light is greater than the transmission of the first light in the second optical filter. The optical detection module is used for creating a first control signal while the first light emitting through the first optical filter at a first zone is detected and a second control signal is created while the second light emitting through the second optical filter at a second zone is detected.

TECHNICAL FIELD

The disclosure relates to an optical sense-control system, and more particularly to an optical sense-control system having a higher identification ratio to lights with different wavebands.

BACKGROUND

A widescreen optical sense-control system, such as an optical touch-panel system, has a wide application such as an electronic whiteboard (E-Board).FIG. 1is a schematic diagram illustrating a user using a conventional optical sense-control system. As depicted inFIG. 1, the conventional optical sense-control system10mainly includes a touch-control panel12. While the user14inputs information on the touch-control panel12via a light pen16, the inputted information is displayed on the touch-control panel12.

To make the user14can use the optical sense-control system10more conveniently, the light pen16is designed to be capable of emitting lights with different colors and the optical sense-control system10can perform a specific response action based on the color of the light received by the optical sense-control system10. For example, information of a specific color or of that a specific command has been executed may be displayed on the touch-control panel12while a corresponding color of light is detected on the touch-control panel12.

Different wavelengths have different transmission ratios (or, intensities) to a same optical filter; this can be used for distinguishing the colors of light.FIG. 2is a schematic chart illustrating the filtering characteristics of the wavelength, transmission ratio and intensity of a blue-light filter, a green-light filter, and a red-light filter which are adopted in the conventional optical sense-control system10. As depicted inFIG. 2, the blue light B, the green light G, and the red light R are defined with different wavelengths λ and frequencies f, based on the transmission ratios T or intensity I thereof relative to the blue-light filter, the green-light filter, and the red-light filter of the optical sense-control system10; where the wavelength λ and the frequency f are reciprocal to each other. As depicted inFIG. 2, in the conventional optical sense-control system10, the blue light B is defined to include the lights with wavelengths within a waveband Bλ; the green light G is defined to include the lights with wavelengths within a waveband Gλ, the red light R is defined to include the lights with wavelengths within a waveband Rλ. Because the blue light B, the green light G, and the red light R are defined in three different specific wavebands in the optical sense-control system10, a specific response action is accordingly performed while a corresponding light with a specific wavelength, which is emitted from the light pen16, is detected by the touch-control panel12. For example, please refer to bothFIG. 1andFIG. 2, a control signal corresponding to the blue light B is created by the optical sense-control system10while a light L1with a wavelength located within the waveband Bλ, is detected on the touch-control panel12.

However, as depicted inFIG. 2, there are overlaps between the definitions of the blue light B, the green light G, and the red light R in the conventional optical sense-control system10. If a specific light with a wavelength which are located in the overlap waveband of any two of the wavebands Bλ, Gλ, Rλ, the conventional optical sense-control system10may result in an error detection of the specific light and accordingly perform an error response action. For example, please refer toFIG. 1andFIG. 2again, if a light L2, having a wavelength located in both the waveband Bλand the waveband Gλ, is emitted to the touch-control panel12from the light pen16, the optical sense-control system10may create a control signal corresponding to both the blue light B and the green light G due to both the blue-light filter (not shown) and the green-light filter detect the light L2, even though the light L2had a much higher transmission ratio to the blue-light filter than that to the green-light filter.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 3schematically illustrates one of the optical sense-control units adopted in an optical sense-control system of the present embodiment; wherein the optical sense-control system of the present embodiment includes n*m optical sense-control units. As depicted inFIG. 3, the optical sense-control unit20, arranged in the optical sense-control system of the present embodiment, includes a blue-light filter22, a green-light filter24, a red-light filter26, and an optical sense device array28. In the optical sense-control unit20, the lights corresponding to a specific waveband Bλand capable of passing through the blue-light filter22, is defined as blue light B; the lights corresponding to a specific waveband Gλand capable of passing through the green-light filter24, is defined as green light G; and the light corresponding to a specific waveband Rλand capable of passing through the red-light filter26, is defined as red light R; wherein the blue light B, the green light G, and the red light R are emitted from a light pen (not shown), Bλ<Gλ<Rλ, and there is no overlap between the wavebands Bλ, Gλ, and Rλ. In other words, the blue-light filter22has a filtering characteristic of having a higher transmission ratio to the blue light B rather than that to the green G light and the red R light; the green-light filter24has a filtering characteristic of having a higher transmission ratio to the green light G rather than that to the blue light B and the red light R; the red-light filter26has a filtering characteristic of having a higher transmission ratio to the red light R rather than that to the blue light B and the green light G; wherein the intensity of the blue light B is concentrated in the range of waveband Bλ, the intensity of the green light G is concentrated in the range of waveband Gλ, and the intensity of the red light R is concentrated in the range of waveband Rλ, as mentioned above.

Moreover, as depicted inFIG. 3, the optical sense device array28includes a blue-light sensor32, a green-light sensor34, and a red-light sensor36, respectively used for detecting the intensity of the lights30capable of passing through the blue-light filter22, the green-light filter24, and the red-light filter26. Alternatively, the blue-light sensor32, the green-light sensor34, and the red-light sensor36can be also three corresponding optical sensing zones. Moreover, a specific control signal S(B, G, R) is created and outputted from the optical sense device array28according to the intensity of the lights30detected by the blue-light sensor32, the green-light sensor34, and the red-light sensor36.

For example, a first control signal (i.e., S(B, G, R)=S(1, 0, 0)), corresponding to the blue light B, is created and outputted from the optical sense device array28if only the blue-light sensor32detects the intensity of the lights30which is capable of passing through the blue-light filter22; a second control signal (i.e., S(B, G, R)=S(0, 1, 0)), corresponding to the green light G, is created and outputted from the optical sense device array28if only the green-light sensor34detects the intensity of the light30which is capable of passing through the green-light filter24; and a third control signal (i.e., S(B, G, R)=S(0, 0, 1)), corresponding to the red light R, is created and outputted from the optical sense device array28if only the red-light sensor36detects the intensity of the light30which is capable of passing through the red-light filter26.

Instead of being composed by a single color light which is emitted from a single light source, it is to be understood that the lights30can be composed by multiple color lights which are emitted from multiple light sources. Therefore, a fourth control signal (i.e., S(B, G, R)=S(1, 1, 0)), corresponding to the blue light B and the green light G, is created and outputted from the optical sense device array28if both the blue-light sensor32and the green-light sensor34detect the intensity of the lights30capable of passing through the blue-light filter22and the green-light filter24; a fifth control signal (i.e., S(B, G, R)=S(0, 1, 1)), corresponding to the green light G and the red light R, is created and outputted from the optical sense device array28if both the green-light sensor34and the red-light sensor36detect the intensity of the lights30capable of passing through the green-light filter24and the red-light filter26; a sixth control signal (i.e., S(B, G, R)=S(1, 0, 1)), corresponding to the blue light B and the red light R, is created and outputted from the optical sense device array28if both the blue-light sensor32and the red-light sensor36detect the intensity of the lights30capable of passing through the blue-light filter22and the red-light filter26; and a seventh control signal (i.e., S(B, G, R)=S(1, 1, 1)), corresponding to the blue light B, the green light G, and the red light R, is created and outputted from the optical sense device array28if all the blue-light sensor32, the green-light sensor34, and the red-light sensor36detect the intensity of the lights30capable of passing through the blue-light filter22, the green-light filter24, and the red-light filter26. Moreover, it is to be understood that the lights30can be emitted from a single light pen which is capable of emitting a single color light or emitting multiple color lights; or, the lights30composed by multiple color lights can be emitted from multiple light pens each emitting a single color light.

FIG. 4Ais a schematic chart illustrating the filtering characteristics of the blue-light filter22, the green-light filter24, and the red-light filter26to the wavelength, transmission ratio and intensity of the lights, according to the first embodiment of the present invention. As depicted inFIG. 4A, the waveband Bλof the blue light B is defined in the first embodiment as a range of wavelengths BL˜BHwhich correspond to the highest intensity of the lights capable of passing through the blue-light filter22; the waveband Gλof the green light G is defined as a range of GL˜GHwhich correspond to the highest intensity of the lights capable of passing through the green-light filter24; the waveband Rλof the red light R is defined as a range of RL˜RHwhich correspond to the highest intensity of the lights capable of passing through the red-light filter26. In the first embodiment, a specific control signal S(B, G, R) is outputted from the optical sense device array28while wavelengths within a corresponding waveband is detected. For example, please refer to both theFIG. 3andFIG. 4B, if the lights30are composed by a single light L1whose waveband is within the range of BL˜BH, the lights30can only pass through the blue-light filter22so that only the blue-light sensor32can detect the intensity of the lights30, thereby a first control signal (i.e., S(B, G, R)=S(1, 0, 0)) corresponding to the blue light B is created and outputted from the optical sense device array28. Please refer to both theFIG. 3andFIG. 4C, if the lights30are composed by two lights L1and L2, wherein the waveband of the light L1is within the range of BL˜BHand the waveband of the light L2is within the range of GL˜GH, the lights30can pass through both the blue-light filter22and the green-light filter24so that the blue-light sensor32can detect the intensity of light L1and the green-light sensor34can detect the intensity of light L2, thereby a fourth control signal (i.e., S(B, G, R)=S(1, 1, 0)) corresponding to the blue light B and the green light G is created and outputted from the optical sense device array28.

FIG. 5Ais a schematic chart illustrating the filtering characteristics of the blue-light filter22, the green-light filter24, and the red-light filter26to the wavelength, transmission ratio and intensity of the lights, according to the second embodiment of the present invention. As depicted inFIG. 5A, the waveband Gλof the green light G is defined in the second embodiment between wavelengths X1˜X2, wherein the wavelength X1corresponds to the 50% of the maximum intensity of the lights capable of passing through the blue-light filter22, and the wavelength X2corresponds to the 50% of the maximum intensity of the lights capable of passing through the red-light filter26. Therefore, as depicted inFIG. 5A, the wavelength X1corresponds to 50% of the maximum transmission ratio (or full-width-at-half-maximum) of the blue-light filter22, that is, the wavelength X1corresponds to the transmission ratio of 35% due to the maximum transmission ratio of the blue-light filter22is about 70%; and the wavelength X2corresponds to 50% of the maximum transmission ratio of the blue-light filter22, that is, the wavelength X2corresponds to the transmission ratio of 45% due to the maximum transmission ratio of the red-light filter26is about 90%. Accordingly, the blue light B defined in the second embodiment has a waveband Bλwith wavelengths thereof less than X1, and the red light R defined in the second embodiment has a waveband Rλwith wavelengths thereof greater than X2. In the second embodiment, a specific control signal S(B, G, R) is outputted from the optical sense device array28while wavelengths within a corresponding waveband is detected. For example, please refer to both theFIG. 3andFIG. 5B, if the lights30are composed by a single light L1whose wavelength is less than X1, the lights30can only pass through the blue-light filter22so that only the blue-light sensor32can detect the intensity of the lights30, thereby a first control signal (i.e., S(B, G, R)=S(1, 0, 0)) corresponding to the blue light B is created and outputted from the optical sense device array28. Please refer to both theFIG. 3andFIG. 5C, if the lights30are composed by two lights L1and L2, wherein the wavelength of the light L1is less than X1and the wavelength of the light L2is within the range of X1˜X2, the lights30can pass through both the blue-light filter22and the green-light filter24so that the blue-light sensor32can detect the intensity of light L1and the green-light sensor34can detect the intensity of light L2, thereby a fourth control signal (i.e., S(B, G, R)=S(1, 1, 0)) corresponding to the blue light B and the green light G is created and outputted from the optical sense device array28.

It is to be understood that the second embodiment needs not be limited to set the wavelength X1to correspond to 50% of the maximum transmission ratio of the lights capable of passing through the blue-light filter22, and not be limited to set the wavelength X2to correspond to 50% of the maximum transmission ratio of the lights capable of passing through the red-light filter26. The wavelength X1can be set to correspond to other ratio of the maximum transmission ratio of the blue-light filter22, such as 30%, and the wavelength X2can also be set to correspond to other ratio of the maximum transmission ratio of the red-light filter26, such as 30%. However, the ratio 50% has a better practice than the ratio 30% has.

FIG. 6Ais a schematic chart illustrating the filtering characteristics of the blue-light filter22, the green-light filter24, and the red-light filter26to the wavelength, transmission ratio and intensity of the lights, according to the third embodiment of the present invention. As depicted inFIG. 6A, the waveband Gλof the green light G defined in the third embodiment is between wavelengths X1˜X2; wherein the wavelength X1corresponds to a junction where the blue-light filter22and the green-light filter24have a same transmission ratio to a same light, and the wavelength X2corresponds to a junction where the green-light filter24and the red-light filter26have a same transmission ratio to a same light. Accordingly, the blue light B defined in the third embodiment has a waveband Bλwith wavelengths thereof less than X1, and the red light R defined in the third embodiment has a waveband Rλwith wavelengths thereof greater than X2. In the third embodiment, a specific control signal S(B, G, R) is outputted from the optical sense device array28while wavelengths within a corresponding waveband is detected. For example, please refer to both theFIG. 3andFIG. 6B, if the lights30are composed by a single light L1whose wavelength is less than X1, the lights30can only pass through the blue-light filter22so that only the blue-light sensor32can detect the intensity of the lights30, thereby a first control signal (i.e., S(B, G, R)=S(1, 0, 0)) corresponding to the blue light B is created and outputted from the optical sense device array28. Please refer to both theFIG. 3andFIG. 6C, if the lights30are composed by two lights L1and L2, wherein the wavelength of the light L1is less than X1and the wavelength of the light L2is within the range of X1˜X2, the lights30can pass through both the blue-light filter22and the green-light filter24so that the blue-light sensor32can detect the intensity of light L1and the green-light sensor34can detect the intensity of light L2, thereby a fourth control signal (i.e., S(B, G, R)=S(1, 1, 0)) corresponding to the blue light B and the green light G is created and outputted from the optical sense device array28.

Based on the characteristics of the present invention, a first control signal is created by the optical sense device array28if a first light is detected in a first optical sensing zone of the optical sense device array28; a second control signal is created by the optical sense device array28if a second light is detected in a second optical sensing zone of the optical sense device array28; accordingly, a nthcontrol signal is created by the optical sense device array28if a nthlight is detected in a nthoptical sensing zone of the optical sense device array28.

Summarily, the identification rate to distinguish the blue, green, and red lights with different wavebands is accordingly increasing, by the blue-light filter22, the green-light filter24, and the red-light filter26in the optical sense-control system of the present invention.

Moreover, the definition approach to distinguish the blue light (waveband Bλ), the green light (waveband Gλ), and the red light (waveband Rλ) using the blue-light filter22, the green-light filter24, and the red-light filter26in the embodiments can be mutually combined. For example, the green light G can be defined as the lights having a waveband Gλwith a range of X1˜X2, wherein the wavelength X1corresponds to a junction where the blue-light filter22and the green-light filter24have a same transmission ratio of a same light, and the wavelength X2corresponds to 50% of the maximum intensity of the lights capable of passing through the red-light filter26. Accordingly, the blue light G is defined as the lights having wavelengths less than X1and the red light R is defined as the lights having wavelength greater than X2.

Moreover, the embodiments of the present invention can be also applied to color-mixed lights which have wavelengths crossing more than one wavebands. For example, please refer to both theFIG. 3andFIG. 4D, if the lights30are composed by color-mixed lights L3whose wavelengths are crossing BH˜GL, the lights30can pass through both the blue-light filter22and the green-light filter24so that both the blue-light sensor32and the green-light sensor34detect the intensity of the lights30, thereby a fourth control signal (i.e., S(B, G, R)=S(1, 1, 0)) corresponding to the blue light B and the green light G is created and outputted from the optical sense device array28.

Moreover, it is to be understood that the embodiments need not be limited to adopt the three blue-light sensor32, the green-light sensor34, and the red-light sensor36for detecting the intensity of lights capable of passing through the blue-light filter22, the green-light filter24, and the red-light filter26, respectively. The embodiments can also adopt a single optical sensing device for detecting the intensity of the blue light, the green light, and the red light.

Moreover, it is to be understood that the embodiments need not be limited to adopt the blue-light filter22, the green-light filter24, and the red-light filter26for detecting the intensity of the blue light, the green light, and the red light, respectively. The concept of the embodiments can also be applied to other primary-color filters, such as the RGBC, RGBCY, RGBW filters.

Moreover, it is to be understood that the concept of the embodiments can also be applied to Color Filter on Array (COA) technology, or the RGBC, the RGBCY, and the RGBW touch-control panels. Moreover, the n-color touch panel in the embodiments can have n optical sensing zones, or multiple colors can be detected in a single optical sensing zone.