TW201317864A - Optical touch panel system and positioning method thereof - Google Patents

Abstract

The present invention discloses an optical touch panel system and a positioning method using for the same system. The system positions an object existing in a touch control area, and comprises: at least one reflective element disposed on a side of the touch control area; at least one light guide modulus disposed on a side of the touch control area adjacent to or opposite the reflective element and emitting light; an image sensor capturing an image of the object; a plurality of first photo-detector arranged on a side of the touch control area adjacent to the image sensor and detecting the object to obtain a first shading information; and a processor calculating the coordinate of the object according to the object image and the first shading information.

Description

Optical touch system and positioning method thereof

The invention relates to an optical touch system and a positioning method thereof, in particular to an optical touch system and a positioning method thereof, which use a plurality of photo-detectors to solve a blind zone problem.

The touch screen device is a device that allows the user to interact directly with the application on the screen. There are many types of touch screen devices, of which optical touch screens are common.

1 shows a conventional optical touch screen system 1 disclosed in U.S. Patent No. 4,782,328. As shown in FIG. 1 , the optical touch screen system 1 includes two sensors 11 , and the two sensors 11 are used to capture an image of the object 13 on the touch area 12 . The processor 14 is coupled to the two sensors 11 to analyze the images generated by the two sensors 11 to determine the sensing path 15 connecting the objects 13 and the two sensors 11 respectively. The processor 14 then calculates the position coordinates of the object 13 based on the sensing route 15. When the object 13 is located in the middle portion 16 of the touch panel 12 and the same side of the two sensors 11, since the object 13 falls outside the viewing angle of the two sensors 11, the object 13 is imaged on the two sensors 11 The quality of the image is poor or unrecognizable, that is, the intermediate zone 16 is called a blind zone.

Figure 2 shows another conventional optical touch screen system 2. The Republic of China Invention Patent Publication No. 201003477 (corresponding to: US Pat. No. 7,689,381 B2) discloses an optical touch screen system 2 including a mirror 21, two light sources 22, an image sensor 23 and a process 24. The mirror 21 and the two light sources 22 are disposed at the periphery of the touch area 28, and the mirror 21 is used to generate a mirror image 26 of the object 25. The image sensor 23 is used to generate an image of the image of the object 25 and an image of the image 26 . The processor 24 analyzes the sensing route 27 through the image of the object 25 and the sensing route 27 through the image of the mirror 26, and calculates the coordinates of the object 25 from the two sensing routes 27.

In the optical touch screen system 2, when the two sensing routes 27 are too close, the image of the object 25 and the image of the mirror image 26 overlap, so that the position of the object 25 cannot be calculated. As shown in FIG. 2, in the touch area 28, close to the image sensor 23 and not provided with a partial area on the side of the light source 22, the image of the object overlaps with the mirror image, thereby preventing the position of the object from being detected. Therefore, the local area is called a blind spot.

In order to solve the problem of the aforementioned blind spot, an optical touch device as disclosed in FIG. 3 is disclosed in the Republic of China Invention Patent Application No. 098131423 (also disclosed in FIG. 10 of the US Patent Publication No. 20100309169). The optical touch device 100a includes a light emitting element 120, an image detecting module 130, two light guiding strips (112a, 112b), and two strip mirrors (114a, 114b). The light guiding strips 112a, 112b are disposed adjacent to each other, and the strip mirrors 114a, 114b are also disposed adjacent to each other, and the light guiding strips 112a, 112b and the strip mirrors 114a, 114b are arranged along four sides of a rectangle, and the area inside the rectangle It is a sensing area 116. The light guide module 110a includes two strip mirrors (114a, 114b), so that each touch point located in the sensing area 116 generates three mirror images correspondingly, and the image detecting module 130 captures the image of the object B and three The images of B1 to B3 are mirrored, and the position of the object B is calculated based on these images. Although the area of the blind spot 150a of the optical touch device 100a is greatly reduced, the problem of the blind spot still exists, that is, the dark spot images of B and B1 and the dark spot images of B2 and B3 partially overlap.

In view of the above, the present invention provides an optical touch system using a plurality of photodetectors and a positioning method thereof, which can effectively solve the problem of the blind zone and improve the accuracy of object positioning.

One of the objects of the present invention is to provide an optical touch system that can solve the blind spot problem.

Another object of the present invention is to provide a positioning method for an optical touch system.

For one of the above purposes, the present invention provides an optical touch system for positioning an object present in a touch area, comprising: at least one reflective element disposed on one side of the touch area The at least one light guide module is disposed on a side of the touch area adjacent to or facing the reflective element, and generates light; an image sensor captures an image of the object; a photodetector, arranged on a side of the touch area adjacent to the image sensor, and detecting the object to obtain a first shading information; and a processor according to the image of the object and the The first shading information is used to calculate a coordinate of the object.

In one embodiment, the image sensor is disposed at one end of a side of the touch area that faces the reflective element.

In one embodiment, the optical touch system further includes a plurality of light emitting units disposed in the touch area and corresponding segments of the plurality of first photodetectors facing one side.

In one embodiment, the light guide module includes a light guide strip and at least one light emitting element disposed on one end surface of the light guide strip.

In one embodiment, the number of the light guide modules is two, and is respectively disposed on one side of the touch area adjacent to and facing the reflective element.

In one embodiment, the optical touch system further includes a plurality of second photodetectors disposed on the same side of the reflective component as the reflective component, wherein the plurality of second photodetectors and The plurality of first photodetectors are adjacent to each other, and the plurality of second photodetectors detect the object to obtain a second shading information for providing the processor to calculate a coordinate of the object.

In one embodiment, the optical touch system further includes a plurality of second photodetectors disposed in the touch area facing the side of the reflective element, wherein the plurality of second photodetectors Adjacent to the image sensor, the plurality of second photodetectors detect the object to obtain a second shading information for providing the processor to calculate a coordinate of the object.

In one embodiment, the first photodetector is a photodiode or a phototransistor.

In one embodiment, the reflective element is a retroreflective sheeting.

In one embodiment, the image sensor and the plurality of first photodetectors sequentially receive light at different times.

In another aspect, the present invention provides an optical touch system for positioning an object in a touch area, comprising: two image sensors disposed at one end of one side of the touch area; Obtaining an image of the object; a plurality of photodetectors arranged in an intermediate portion of the touch area in the same side of the two image sensors, and detecting the object to obtain a shading information; and processing And calculating a coordinate of the object according to the image of the object and the shading information.

In one embodiment, the optical touch system further includes at least one reflective component disposed on a side of the touch area different from the two image sensors.

In one embodiment, the optical touch system further includes at least one light guide module disposed on a side of the touch area different from the two image sensors.

In another aspect, the present invention provides a method for positioning an optical touch system, comprising: capturing, by at least one image sensor, an image of an object existing in a touch area; a photodetector detects the object to obtain a first shading information; and calculates a position coordinate of the object based on the image and the first shading information.

The purpose, technical content, features and effects achieved by the present invention will be more readily understood by the detailed description of the embodiments.

4 is a schematic view showing an optical touch system according to an embodiment of the present invention. When an object 45 (eg, a finger or stylus pen) contacts the touch area 48 of the optical touch system 4, the system calculates the coordinates at which the object 45 is located. The optical touch system 4 includes a reflective component 411 , a first light guide module 421 , a second light guide module 422 , an image sensor 43 , a plurality of light detectors 49 , and a processor 44 . The reflective element 411 is disposed on the first side 481 of the touch area 48, and the first light guide module 421 and the second light guide module 422 are respectively disposed on the adjacent second side 482 and the second of the touch area 48. Three sides 483. The first light guide module 421 can be a combination of a light guide strip 423 and at least one light emitting element 424, and the second light guide module 422 can also be a combination of a light guide strip 425 and at least one light emitting element 426, but not in this example. For the limit. The light-emitting element 424 is located at two opposite end faces of the light-guiding strip 423. The light-guiding strip 423 guides the light emitted by the light-emitting element 424 to the surface facing the touch-control area 48. The light passes through the light-guiding strip 423 and is projected to the touch area. Within 48. The light-emitting elements 424 and 426 may be linear light sources that emit invisible light, and the image sensor 43 has an image-sensing window and a filter.

As shown, when the object 45 is in the blind spot in the touch area 48, the plurality of photodetectors 49 on the fourth side 484 will receive light from the opposite first light guide module 421, but the object 45 will obscure. Part of the light. Therefore, at least one photodetector 49 will not receive enough light, and other photodetectors 49 will receive the light. Therefore, the position of the object 45 located in the blind spot can be clearly defined by the shading information obtained by the photodetectors 49. The photodetector 49 is a photodiode or phototransistor, or other optoelectronic semiconductor component that accepts light as a switch.

The first light guide module 421 and the second light guide module 422 can be replaced by other light-emitting elements, as long as the light can illuminate the object 45 in the touch area 48, and the image sensor 43 and the light detector 49 also receive the light. Moreover, in order to make the quality of the masking information obtained by the photodetector 49 better, the first light guide module 421 and the second light guide module 422 can be illuminated in two stages. That is, when the image sensor 43 captures the image in the first stage, the first light guide module 421 and the second light guide module 422 collectively emit light; and in the second stage, the light detection When the device 49 starts detecting the object 45, only the first light guide module 421 emits light, and the second light guide module 422 is closed to prevent the light generated by the light guide from entering the light detector 49 laterally. If the first light guide module 421 and the second light guide module 422 are simultaneously illuminated, the light detector 49 can still clearly detect the masking information of the object 45, and thus does not need to be divided into multi-stage illumination. In the second stage, only the photodetector 49 receives light. To avoid more than the light source interfering with the sensing of the photodetector 49, only the light source facing the photodetector 49 may be turned on, for example, only the first A light-emitting element 424' of a light guide module 421. In this way, it can be avoided by other interference, and it can also achieve the function of saving electricity.

The processor 44 analyzes the position information of the object in the occlusion information obtained by the photodetector 49, and analyzes the position information of the object in the global image captured by the image sensor 43, and then combines the two position information to obtain the position coordinate of the object.

FIG. 5 is a schematic view showing an optical touch system according to another embodiment of the present invention. The second side 482 of the optical touch system 4' is provided with a plurality of light emitting units 427, such as light emitting diodes. Moreover, each of the light-emitting units 427 and the photodetectors 49 located at the fourth side 484 form a light emitting and receiving pair, so that better shielding information can be obtained. The first light guide module 421' is adjacent to the plurality of light emitting units 427, and the light emitting elements 424 are located at opposite end faces of the light guiding strips 423'.

FIG. 6 is a schematic view showing an optical touch system according to another embodiment of the present invention. Compared with FIG. 4, the optical touch system 6 of the present embodiment includes two image sensors 43. Since the middle zone of the same side (the third side 483) of the two image sensors 43 is a blind zone, a plurality of photodetectors 49 are disposed in the middle section of the third side 483. In addition, the two first light guiding modules 421 are disposed on the opposite second side 482 and the fourth side 484, and the first reflective element 411 is disposed on the first side 481. The first side 481, the second side 482, and the fourth side 484 may be selected to be any one of the light guide module and the reflective element, and are not limited by this embodiment. The processor 44 calculates the position coordinates of the object 45 based on the images captured by the two image sensors 43 (including the real image and the virtual image of the image) and the masking information obtained by the photodetector 49.

FIG. 7 is a schematic view showing an optical touch system according to another embodiment of the present invention. Compared with FIG. 4, the optical touch system 7 of the present embodiment further includes a plurality of photodetectors 49' disposed on the first side 481. Further, the first reflective element 411' is adjacent to the plurality of photodetectors 49'. Moreover, in order to make the quality of the masking information obtained by the photodetector 49 better, the first light guide module 421 and the second light guide module 422 can be illuminated in three stages. That is, when the image sensor 43 captures the image in the first stage, the first light guide module 421 and the second light guide module 422 jointly emit light; when in the second stage, the light detectors 49, starting to detect the object 45, only the first light guide module 421 emits light, and the second light guide module 422 is closed to prevent the light generated by the light entering the light detector 49 from the lateral direction; In the three stages, the photodetectors 49' start detecting the object 45, and only the second light guide module 422 emits light, and the first light guide module 421 is closed to prevent the light generated by the side from entering. Within the photodetector 49'.

FIG. 8 is a schematic view showing an optical touch system according to another embodiment of the present invention. In this embodiment, a plurality of photodetectors 49' are disposed on the third side 483. The light guiding strip 425' of the second light guiding module 422' is adjacent to the photodetectors 49'. Similarly, the first light guide module 421 and the second light guide module 422' can be illuminated in three stages.

The present invention has been described with reference to the preferred embodiments thereof, and the present invention is not intended to limit the scope of the present invention. In the same spirit of the invention, various equivalent changes can be conceived by those skilled in the art. For example, the position and number of the photodetectors can be different from the examples of the foregoing embodiments. The reflective element may be a retro-reflector, and may be disposed in the three sides (481, 482, 484) facing the two image sensors 43 in the embodiment of FIG. The scope of invention protection. The above and other equivalent variations are intended to be covered by the scope of the invention.

1. . . Optical touch screen system

11. . . Sensor

12. . . Touch area

13. . . object

14. . . processor

15. . . Sensing route

16. . . Middle zone

116. . . Sensing area

1111. . . First reflective element

1112. . . Second reflective element

120. . . Light-emitting element

130. . . Image detection module

100a. . . Optical touch device

110a. . . Light guide module

112a, 112b. . . Light guide strip

114a, 114b. . . Strip mirror

150a. . . Blind zone

2. . . Optical touch screen system

twenty one. . . Reflector

twenty two. . . light source

twenty three. . . Image sensor

twenty four. . . processor

25. . . object

26. . . Mirror

27. . . Sensing route

28. . . Touch area

4~8. . . Optical touch system

43. . . Image sensor

44. . . processor

45. . . object

48. . . Touch area

49, 49’. . . Light detector

411, 411’. . . Reflective element

421, 421’. . . First light guide module

422, 422’. . . Second light guide module

423, 423', 425, 425'. . . Light guide strip

424, 424', 426. . . Light-emitting element

427. . . Light unit

481. . . First side

482. . . Second side

483. . . Third side

484. . . Fourth side

B1~B3. . . Mirror

Figure 1 shows a conventional optical touch screen system.

Figure 2 shows another conventional optical touch screen system.

Figure 3 shows another conventional optical touch screen system.

4 is a schematic view showing an optical touch system according to an embodiment of the present invention.

FIG. 5 is a schematic view showing an optical touch system according to another embodiment of the present invention.

FIG. 6 is a schematic view showing an optical touch system according to another embodiment of the present invention.

FIG. 7 is a schematic view showing an optical touch system according to another embodiment of the present invention.

FIG. 8 is a schematic view showing an optical touch system according to another embodiment of the present invention.

4. . . Optical touch system

43. . . Image sensor

44. . . processor

45. . . object

48. . . Touch area

49. . . Light detector

411. . . Reflective element

421. . . First light guide module

422. . . Second light guide module

423. . . Light guide strip

424. . . Light-emitting element

481. . . First side

482. . . Second side

483. . . Third side

484. . . Fourth side

Claims (21)

An optical touch system is disposed in an object of a touch area, and includes: at least one reflective component disposed on one side of the touch area; at least one light guide module disposed in the touch area An image sensor that captures an image of the object; a plurality of first photodetectors arranged in the touch area and the image sense An adjacent side of the detector, and detecting the object to obtain a first shading information; and a processor calculating a coordinate of the object according to the image of the object and the first shading information. The optical touch system of claim 1, wherein the image sensor is disposed at one end of one side of the touch area facing the reflective element. The optical touch system of claim 1, further comprising a plurality of light-emitting units disposed in the touch area and corresponding to one side of the plurality of first photodetectors. The optical touch system of claim 1, wherein the light guide module comprises a light guide strip and at least one light emitting element disposed on an end surface of the light guide strip. The optical touch system of claim 1, wherein the number of the light guide modules is two, and is respectively disposed on a side of the touch area adjacent to and facing the reflective element. The optical touch system of claim 1, further comprising a plurality of second photodetectors disposed on the same side of the reflective element as the reflective element, wherein the plurality of second optical detectors The detector is adjacent to the plurality of first photodetectors, and the plurality of second photodetectors detect the object to obtain a second shading information for providing the processor to calculate a coordinate of the object. The optical touch system of claim 1, further comprising a plurality of second photodetectors disposed in the touch area facing the side of the reflective element, wherein the plurality of second lights The detector is adjacent to the image sensor, and the plurality of second photodetectors detect the object to obtain a second shading information for providing the processor to calculate a coordinate of the object. The optical touch system of claim 1, wherein the first photodetector is a photodiode or a phototransistor. The optical touch system of claim 1, wherein the reflective element is a retroreflective sheeting. The optical touch system of claim 1, wherein the image sensor and the plurality of first photodetectors sequentially receive light at different times. An optical touch system for positioning an object in a touch area, comprising: two image sensors disposed at two ends of one side of the touch area to capture an image of the object; a plurality of lights The detector is arranged in an intermediate section of the same side of the two image sensors in the touch area, and detects the object to obtain a shading information; and a processor, according to the image of the object and the shading Information to calculate the coordinates of the object. The optical touch system of claim 11, further comprising at least one reflective component disposed on a side of the touch area different from the two image sensors. The optical touch system of claim 12, wherein the reflective element is a retroreflective sheeting. The optical touch system of claim 11, further comprising at least one light guide module disposed on a side of the touch area different from the two image sensors. The optical touch system of claim 14, wherein the light guide module comprises a light guide strip and at least one light emitting element disposed on an end surface of the light guide strip. The optical touch system of claim 11, wherein the photodetector is a photodiode or a phototransistor. A method for positioning an optical touch system includes: capturing, by at least one image sensor, an image of an object existing in a touch area; detecting the object by using a plurality of first photodetectors Obtaining a first shading information; and calculating a position coordinate of the object according to the image and the first shading information. The method for positioning an optical touch system according to claim 17, wherein the image sensor and the plurality of first photodetectors sequentially receive light at different times. The method for positioning an optical touch system according to claim 17, wherein the image includes a real image and a virtual image of the object. The method for positioning an optical touch system according to claim 17, further comprising detecting the object by a plurality of second photodetectors to obtain a second shading information, wherein the plurality of shading information The two photodetectors receive the direction of the light and the direction in which the plurality of first photodetectors receive the light are perpendicular to each other. The method for positioning an optical touch system according to claim 20, wherein the position coordinate of the object is calculated based on the second shading information.