TWI433007B - Optical touch device and locating method thereof - Google Patents

Description

Optical touch device and positioning method thereof

The present invention relates to a touch device, and more particularly to an optical touch device and a positioning method thereof.

Touch function has become one of the essential functions of many electronic devices today, and the touch device is a common electronic component required for implementing touch functions. At present, the types of touch devices mainly include resistive, capacitive, optical, etc., and electronic devices can be matched with different types of touch devices according to different touch requirements.

FIG. 1 is a schematic structural view of a conventional optical touch device. Referring to FIG. 1 , the optical touch device 100 includes a light guiding module 110 , a light source module 120 , and an image detecting module 130 . The light guiding module 110 includes reflective strips 112a, 112b, 112c, and 112d arranged in sequence along four sides of a rectangular track, and the area in the rectangular track is a sensing area 114. In addition, the light source module 120 includes light-emitting elements 122a, 122b, and 122c, wherein the light-emitting elements 122a are disposed between adjacent ends of the reflective strips 112a and the reflective strips 112b, and the light-emitting elements 122b are disposed between the reflective strips 112b and the reflective strips 112c. Between the adjacent ends, the light-emitting element 122c is disposed between the adjacent ends of the reflective strip 112a and the reflective strip 112d. The light source module 120 is configured to provide light to the reflective strips 112a, 112b, 112c, and 112d, and the reflective strips 112a, 112b, 112c, and 112d are used to reflect the light provided by the light source module 120. In addition, the image detecting component 132 includes image detecting elements 132a, 132b, and 132c. The image detecting component 132a is disposed between adjacent ends of the reflective strip 112a and the reflective strip 112b, and the image detecting component 132b is disposed on the reflective The strip 112b is disposed between the adjacent ends of the reflective strip 112c, and the image detecting element 132c is disposed between the adjacent ends of the reflective strip 112a and the reflective strip 112d.

In the above, the image detecting module 130 is configured to detect whether there is a touch point (ie, a shade) in the sensing area 114, and calculate the position of the touch point. The optical touch device 100 has a multi-touch function. For example, when there are two touch points in the sensing area 114, each of the image detecting elements 132a, 132b, and 132c should detect two dark spots respectively. In theory, the position (or coordinate) of the two touch points can be calculated by the dark spots detected by any two of the image detecting elements 132a, 132b, and 132c. However, in some cases, one of the image detecting elements 132a, 132b, 132c may only detect one dark spot.

For example, as shown in FIG. 2, when there are two touch points A and B in the sensing area 114, the image detecting component 132a detects the dark spots A1 and B1, and the image detecting component 132b detects To the dark spots A2, B2, the image detecting component 132c will detect the dark spots A3, B3, wherein the dark spots A1, A2, A3 are caused by the touch point A, and the dark spots B1, B2, B3 are touch Caused by point B. However, since the dark spot A1 overlaps the dark spot B1, the image detecting element 132a detects only one dark spot. Thus, when the center of gravity A1 and the dark point B1 are calculated by the algorithm of the center of gravity, an error occurs, that is, a so-called center of gravity shift occurs.

According to the above, when the positions of the touch points A and B are calculated by using the dark spots A1, B1, A2, and B2 detected by the image detecting elements 132a and 132b, one of the straight lines L1 and L2 can be used to calculate one of the points. The position of the touch point, and the position of the other touch point is calculated by the straight line L1 and the straight line L3. However, the above-mentioned problem of center of gravity shift may cause a large error between the calculated positions of the two points A', B' and the positions of the actual touch points A, B. Similarly, when the positions of the touch points A and B are calculated using the dark spots A1, B1, A3, and B3 detected by the image detecting elements 132a and 132c, the same problem occurs.

In addition, when the positions of the touch points A and B are calculated by using the dark spots A2, B2, A3, and B3 detected by the image detecting elements 132b and 132c, the line L2 and the line L5 can be used to calculate one of the touches. Control the position of the point and use the line L3 and the line L4 to calculate the position of the other touch point. However, the slope of the straight line L2 and the straight line L5 is too close, and the slopes of the straight line L3 and the straight line L4 are too close, which may result in the calculated positions of the two points A", B" and the positions of the actual touch points A, B. Larger error.

In addition, the conventional optical touch device 100 has a certain blind zone. The blind spot here means that the image detecting elements 132b and 132c of the image detecting module 130 cannot detect the dark spots caused by the touch points, and thus the area where the touch points are located cannot be calculated. For example, as shown in FIG. 3, the field of view (FOV) of the image detecting component 132b covers the reflective strips 112a and 112d, but a gap exists between the reflective strip 112a and the reflective strip 112d to set the image detecting component. 132c. Since the image detecting element 132c cannot reflect the light, and the image detecting element 132b cannot detect the touch point C in the area 150, the area 150 is a so-called dead zone. In addition, when the touch point D is located in the area 150, the image detector 130b cannot accurately detect the dark point caused by the touch point D, so that the touch point D cannot be accurately calculated. s position. In addition, the image detecting component 132c has a similar blind spot problem when detecting.

The invention provides an optical touch device for accurately calculating the position of a touch point and effectively solving the problem of the blind spot.

The invention further provides a positioning method of an optical touch device to accurately calculate the position of the touch point and effectively solve the problem of the blind spot.

To achieve the above advantages, the present invention provides an optical touch device including a frame, a light source module, a first image detecting component, a second image detecting component, a third image detecting component, and a mirror surface. element. The frame body includes a first wall, a second wall, a third wall and a fourth wall. The first wall is opposite to the third wall, the second wall is opposite to the fourth wall, and the area enclosed by the frame is a sensing area. The light source module is used to provide light to the sensing area. The first image detecting element is disposed between adjacent ends of the first wall and the second wall, and the field of view covers the third wall and the fourth wall. The second image detecting component is disposed between the adjacent ends of the second wall and the third wall, and the field of view covers the first wall and the fourth wall. The third image detecting component is disposed between adjacent ends of the first wall and the fourth wall, and the field of view covers the second wall and the third wall. The mirror element is disposed on the fourth wall. The mirror component is adapted to form a virtual image at one of the touch points in the sensing area, and the first image detecting component and the second image detecting component are adapted to detect optical information of the touch point and the virtual image.

In an embodiment of the invention, the light source module includes a first light emitting element, a second light emitting element, and a third light emitting element. The first illuminating element is disposed between adjacent ends of the first wall and the second wall. The second light emitting element is disposed between the adjacent ends of the second wall and the third wall. The third light emitting element is disposed between adjacent ends of the first wall and the fourth wall.

In an embodiment of the invention, the optical touch device further includes a first light guiding element, a second light guiding element and a third light guiding element. The first light guiding element is disposed on the first wall, the second light guiding element is disposed on the second wall, and the third light guiding element is disposed on the third wall.

In an embodiment of the invention, the first light guiding element, the second light guiding element and the third light guiding element are respectively a reflective strip, and the first light emitting element, the second light emitting element and the third light emitting element are oriented The measurement area emits light, and the first light guiding element, the second light guiding element and the third light guiding element are for reflecting light transmitted to the first light guiding element, the second light guiding element and the third light guiding element to the sensing region.

In an embodiment of the invention, the first light guiding element, the second light guiding element and the third light guiding element are respectively a light guiding strip, and each has a light emitting surface facing the sensing area and the light emitting surface An adjacent one of the light incident surfaces, the first light emitting element, the second light emitting element, and the third light emitting element respectively emit light toward the light incident surface of the first light guiding element, the second light guiding element, and the third light guiding element, and the light system is The first light guiding element, the second light guiding element, and the light emitting surface of the third light guiding element are emitted to be transmitted to the sensing region.

In an embodiment of the invention, the first light emitting element, the second light emitting element and the third light emitting element are respectively light emitting diodes.

In an embodiment of the invention, the first image detecting component, the second image detecting component and the third image detecting component respectively comprise a detecting unit and a digital signal processing electrically connected to the detecting unit unit.

In an embodiment of the present invention, the optical touch device further includes a substrate, wherein the pivot, the light source module, the first image detecting component, the second image detecting component, and the third image detecting component are disposed on Substrate.

In order to achieve the above advantages, the present invention further provides a positioning method of an optical touch device, which is suitable for the above optical touch device. The method for positioning the optical touch device includes: forming a virtual image by a mirror element in a touch point of the sensing area; using the first image detecting component, the second image detecting component, and the third image detecting component to detect Measuring a position of a dark point caused by the touch point to obtain a first optical information, and using the first image detecting component and the second image detecting component to detect a position of a dark point caused by the virtual image to obtain a second optical information And determining a location of the touch point located in the sensing area according to the first optical information and the second optical information.

In the optical touch device and the positioning method thereof, since the mirror component of the light guiding module can generate virtual image information, the first image detecting component and the second image detecting component can detect more effective and available. Optical information, so that the location of the touch point can be accurately calculated and the problem of blind spots can be effectively avoided.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

FIG. 4 is a schematic structural diagram of an optical touch device according to an embodiment of the invention. Referring to FIG. 4, the optical touch device 200 of the present embodiment includes a frame 210, a light source module 220, a first image detecting component 232, a second image detecting component 234, and a third image detecting device. Element 236 and a mirror element 218. In this embodiment, the frame 210 is, for example, a rectangular frame, and includes a first wall 201, a second wall 202, a third wall 203, and a fourth wall 204. The first wall 201 is opposite to the third wall 203, the second wall 202 is opposite to the fourth wall 204, and the area surrounded by the first wall 201, the second wall 202, the third wall 203, and the fourth wall 204 of the frame 210 is A sensing area 219. The light source module 220 is configured to provide light to the sensing area 219. The mirror element 218 is disposed on the fourth wall 204 of the frame 210, and the mirror element 218 is configured to form a virtual image at a touch point in the sensing area, and the first image detecting component 232 and the second image detecting The component 234 and the third image detecting component 236 are configured to detect optical information of the touch point located in the sensing area 219 and the corresponding virtual image.

In this embodiment, the optical touch device 200 further includes a substrate (not shown), and the frame 210, the light source module 220, the first image detecting component, the second image detecting component, and the third image detecting device. The measuring component can be disposed on the substrate.

In addition, in the embodiment, the optical touch device 200 further includes a first light guiding component 212, a second light guiding component 214, and a third light guiding component 216. The first light guiding element 212 , the second light guiding element 214 and the third light guiding element 216 are respectively disposed on the first wall 201 , the second wall 202 , and the third wall 203 of the frame 210 . The first light guiding element 212, the second light guiding element 214 and the third light guiding element 216 are respectively, for example, a reflective strip for transmitting to the first light guiding element 212, the second light guiding element 214 and the third guiding Light from the light element 216 is reflected to the sensing region 219.

The light source module 220 includes a first light emitting element 222, a second light emitting element 224, and a third light emitting element 226. The first light-emitting element 222, the second light-emitting element 224, and the third light-emitting element 226 are respectively a light-emitting diode, but are not limited thereto. In this embodiment, the first light-emitting element 222 is disposed between the first end 201 of the frame 210 and the adjacent ends of the second wall 202 (ie, the first light guiding element 212 and the second light guiding element 214). Between adjacent ends). The second light-emitting element 224 is disposed between the two ends of the second wall 202 and the third wall 203 of the frame 210 (ie, the adjacent ends of the second light guiding element 214 and the third light guiding element 216). between). The third light-emitting element 226 is disposed, for example, between the adjacent ends of the first wall 201 and the fourth wall 204 of the frame 210 (ie, between the first ends of the first light guiding element 212 and the mirror element 218) . In the present embodiment, the first light-emitting element 212, the second light-emitting element 214, and the third light-emitting element 216 emit light toward the sensing region 219.

The first image detecting component 232 is disposed between the adjacent ends of the first wall 201 and the second wall 202 of the frame 210 (ie, the adjacent ends of the first light guiding component 212 and the second light guiding component 214 Between the third image 203 and the fourth wall 204 of the frame 210 (ie, the third light guiding element 216 and the mirror element 218). The second image detecting component 234 is disposed between the adjacent ends of the second wall 202 and the third wall 203 of the frame 210 (ie, the adjacent ends of the second light guiding component 214 and the third light guiding component 216 The first image 201 and the fourth wall 204 of the frame 210 (ie, the first light guiding element 212 and the mirror element 218) are included in the field of view of the second image detecting element 234. The third image detecting component 236 is disposed between the adjacent ends of the first wall 201 and the fourth wall 204 of the frame 210 (ie, between the first ends of the first light guiding element 212 and the mirror element 218) The field of view of the third image detecting component 236 covers the second wall 202 and the third wall 203 of the frame 210 (ie, the second light guiding element 214 and the third light guiding element 216).

In more detail, an opening is provided between the adjacent ends of the first wall 201 and the second wall 202 for providing the first light-emitting element 222 and the first image detecting element 232. An opening is provided between the second wall 202 and the adjacent ends of the third wall 203 for providing the second light-emitting element 224 and the second image detecting element 234. An opening is provided between the adjacent ends of the first wall 201 and the fourth wall 204 for providing the third light-emitting element 226 and the third image detecting element 236.

The first image detecting component 232 , the second image detecting component 234 , and the third image detecting component 236 respectively include a detecting unit 237 and a digital signal processing unit 238 electrically connected to the detecting unit 237 . The fields of view of the first image detecting component 232, the second image detecting component 234, and the third image detecting component 236 are the fields of view of the detecting unit 237. In addition, the digital signal processing unit 238 is configured to process the detection signal of the corresponding detection unit 237, and transmit the detection signal to a central processing unit (not shown) to calculate the touch point by the central processing unit. s position. The above detection signal is, for example, the position of the dark spot detected by the detecting unit 237.

The positioning method of the optical touch device applicable to the optical touch device 200 described above will be specifically described below, and the optical touch device 200 and its positioning method are specifically described in conjunction with the drawings to avoid darkness caused by multiple touch points. Point overlap, resulting in inaccurate positioning problems.

The method for positioning the optical touch device of the optical touch device 200 includes the following steps: forming a virtual image at a touch point of the sensing region 219 by the mirror element 218; using the first image detecting component 232, The second image detecting component 234 and the third image detecting component 236 detect the position of the dark spot caused by the touch point to obtain a first optical information, and use the first image detecting component 232 and the second image detecting The component 234 detects the position of the dark point caused by the virtual image to obtain a second optical information; and determines the position of the touch point located in the sensing area 219 according to the first optical information and the second optical information.

Referring to FIG. 5 , the optical touch device 200 and the positioning method thereof of the embodiment are used to locate the positions of the two touch points E and F located in the sensing region 219 . Due to the arrangement of the mirror elements 218, the touch points E, F located in the sensing area 219 will form virtual images E1, F1. In this manner, the first image detecting component 232, the second image detecting component 234, and the third image detecting component 236 can detect dark spots caused by the touch points E and F, thereby obtaining a first optical information. The first image detecting component 232 and the second image detecting component 234 can detect dark spots caused by the virtual images E1 and F1, thereby obtaining a second optical information. That is to say, the first optical information relates to the optical information of the touch points E, F, and the second optical information relates to the optical information of the virtual images E1, F1.

In the above, when the image detecting component (such as the first image detecting component 232) detects the dark spots E2 and F2 caused by the touch points E and F, the first image detecting component 232 The dark spots E3 and F3 caused by the virtual images E1 and F1 are not overlapped. That is to say, the first image detecting component 232 can detect the first available optical information, but can detect the second optical information that is effectively available. Therefore, the position of the dark spots E3 and F3 (ie, the second optical information) detected by the first image detecting component 232 can be detected by the second image detecting component 234 or the third image detecting component 236. The position of the dark point (ie, the first optical information) caused by the touch points E and F is measured to accurately calculate the positions of the touch points E and F.

In addition, the optical touch device 200 and the positioning method thereof of the present embodiment can also solve the problem of the blind zone mentioned in the prior art. Referring to FIG. 6 , taking the second image detecting component 234 as an example, since the touch point G is located in the area 250 (ie, the blind area of the prior art), the second image detecting component 234 cannot detect the touch point. The position of the dark spot caused by G. In addition, since a part of the touch point H is located in the area 250, the second image detecting element 234 cannot accurately detect the position of the dark point caused by the touch point G. That is, the second image detecting component 234 cannot detect the first available optical information. However, since the touch points G and H form the virtual images G1 and H1, the second image detecting component 234 can detect the dark spots G2 and H2 caused by the virtual images G1 and H1, and the first image detecting component 232 can The dark spots G3 and H3 caused by the virtual images G1 and H1 are detected. That is, the first image detecting component 232 and the second image detecting component 234 can detect the second optical information that is effectively available. In this way, the positions of the dark spots G3 and H3 detected by the first image detecting component 232 can be accurately calculated according to the positions of the dark points G2 and H2 detected by the second image detecting component 234. The position of the touch points G, H. At the same time, the position of the dark spot caused by the touch points G, H detected by the first image detecting component 232 or the third image detecting component 236 (ie, the first optical information) can be accurately calculated. Control the position of G and H. Therefore, the optical touch device 200 and the positioning method thereof of the present embodiment can effectively solve the problem of the blind zone mentioned in the prior art.

Based on the above, the optical touch device 200 of the present embodiment and the positioning method thereof are provided with the mirror element 218 to enable the touch point located in the sensing region 219 to form a virtual image. Therefore, the first image detecting component 232 and the second image detecting component 234 can detect dark spots caused by the virtual image. In other words, the first image detecting component 232 and the second image detecting component 234 can obtain more optical information to accurately calculate the position of the touch point.

FIG. 7 is a schematic structural diagram of an optical touch device according to another embodiment of the present invention. Referring to FIG. 7 , the optical touch device 200 a of the present embodiment is different from the optical touch device 200 described above in that the first light guiding element 212 a , the second light guiding element 213 a and the third light guiding device of the optical touch device 200 a are Element 214a is a light guide strip, respectively. Specifically, the first light guiding element 212a, the second light guiding element 214a and the third light guiding element 216a respectively have a light emitting surface 32 facing the sensing region 219 and a light incident surface 34 adjacent to the light emitting surface 32. In this embodiment, the first light-emitting element 222, the second light-emitting element 224, and the third light-emitting element 226 are respectively directed toward the light-input surfaces of the first light guide element 212a, the second light guide element 214a, and the third light guide element 216a. 34 lights. The light emitted by the light source module 220 is incident on the first light guiding element 212a and the second light guiding element 214a by the first light guiding element 212a, the second light guiding element 214a and the light incident surface 34 of the third light guiding element 216a. The three light guiding elements 216a, the first light guiding element 212a, the second light guiding element 214a and the third light guiding element 216a convert light into a line light source, and the line light source is emitted from the light emitting surface 32 and transmitted to the sensing area. 219. The touch point positioning method and advantages of the optical touch device 200a are the same as those of the optical touch device 200, and will not be repeated herein.

In summary, in the optical touch device and the positioning method thereof, the first image detecting component and the second image detecting component can detect the virtual image of the touch point generated by the mirror component to obtain more The optical information is so useful for accurately calculating the position of the touch point and solving the problem of the blind spot.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100. . . Conventional optical touch device

110. . . Light guide module

112a, 112b, 112c, 112d. . . Reflective strip

114. . . Sensing area

120. . . Light source module

122a, 122b, 122c. . . Light-emitting element

130. . . Image detection module

132a, 132b, 132c. . . Image detection component

150, 250. . . region

200, 200a. . . Optical touch device

210. . . framework

201. . . First wall

202. . . Second wall

203. . . Third wall

204. . . Fourth wall

212, 212a. . . First light guiding element

214, 214a. . . Second light guiding element

216, 216a. . . Third light guiding element

218. . . Mirror element

219. . . Sensing area

220. . . Light source module

222. . . First illuminating element

224. . . Second illuminating element

226. . . Third illuminating element

232. . . First image detecting element

234. . . Second image detecting element

236. . . Third image detecting element

237. . . Detection unit

238. . . Digital signal processing unit

32. . . Glossy surface

34. . . Glossy surface

A, B, C, D, E, F, G, H. . . Touch point

A’, A”, B’, B”. . . point

A1, A2, A3, B1, B2, B3, E2, E3, F2, F3, G2, G3, H2, H3. . . dark spot

E1, F1, G1, H1. . . Virtual image

L1, L2, L3, L4, L5. . . straight line

FIG. 1 is a schematic structural view of a conventional optical touch device.

FIG. 2 is a schematic diagram showing the overlap of dark spots caused by two touch points in the sensing area of the optical touch device shown in FIG. 1. FIG.

3 is a schematic view of a blind spot of the optical touch device shown in FIG. 1.

4 is a schematic structural view of an optical touch device according to an embodiment of the invention.

FIG. 5 is a schematic diagram showing the overlap of dark spots caused by two touch points in the sensing area of the optical touch device shown in FIG. 4.

FIG. 6 is a schematic diagram of how the optical touch device shown in FIG. 4 solves the blind spot problem of the prior art.

FIG. 7 is a schematic structural diagram of an optical touch device according to another embodiment of the present invention.

200. . . Optical touch device

210. . . framework

201. . . First wall

202. . . Second wall

203. . . Third wall

204. . . Fourth wall

212. . . First light guiding element

214. . . Second light guiding element

216. . . Third light guiding element

218. . . Mirror element

219. . . Sensing area

220. . . Light source module

222. . . First illuminating element

224. . . Second illuminating element

226. . . Third illuminating element

232. . . First image detecting element

234. . . Second image detecting element

236. . . Third image detecting component

237. . . Detection unit

238. . . Digital signal processing unit

Claims (9)

An optical touch device includes: a frame body including a first wall, a second wall, a third wall, and a fourth wall, the first wall being opposite to the third wall, the second wall and the The first wall is opposite to the first wall, and the first image is disposed on the first wall and the first image detecting component. Between adjacent ends of the second wall, and the field of view of the first image detecting component covers the third wall and the fourth wall; a second image detecting component disposed on the second wall and the third Between the adjacent ends of the wall, and the field of view of the third image detecting component covers the first wall and the fourth wall; a third image detecting component disposed on the first wall and the fourth wall Between adjacent ends, and the field of view of the third image detecting element covers the second wall and the third wall; and a mirror element disposed on the fourth wall, wherein the mirror element is adapted to be located One of the touch points in the measurement area forms a virtual image, and the first image detecting component and the second image detecting component are adapted to detect Touch point and the virtual image of the optical information. The optical touch device of claim 1, wherein the light source module comprises: a first light emitting element disposed between the first wall and the adjacent ends of the second wall; a light emitting element disposed between the second wall and the adjacent ends of the third wall; and a third light emitting element disposed between the first wall and the adjacent ends of the fourth wall. The optical touch device of claim 2, wherein the optical touch device further comprises: a first light guiding element disposed on the first wall; and a second light guiding element disposed on the second a wall; and a third light guiding element disposed on the third wall. The optical touch device of claim 3, wherein the first light guiding element, the second light guiding element and the third light guiding element are respectively a reflective strip, the first light emitting element, the first The second light emitting element and the third light emitting element emit light toward the sensing area, and the first light guiding element, the second light guiding element and the third light guiding element are configured to be transmitted to the first light guiding element, the first Light from the two light guiding elements and the third light guiding element is reflected to the sensing area. The optical touch device of claim 3, wherein the first light guiding element, the second light guiding element and the third light guiding element are respectively a light guiding strip, and respectively have a surface facing the sensing a light emitting surface of the region and a light incident surface adjacent to the light emitting surface, the first light emitting element, the second light emitting element and the third light emitting element respectively facing the first light guiding element and the second light guiding element And emitting light to the light incident surfaces of the third light guiding element, and transmitting the light to the light emitting surfaces of the first light guiding element, the second light guiding element and the third light guiding element, and transmitting the light to the light emitting surface Measuring area. The optical touch device of claim 2, wherein the first light-emitting element, the second light-emitting element, and the third light-emitting element are respectively light-emitting diodes. The optical touch device of claim 1, wherein the first image detecting component, the second image detecting component and the third image detecting component respectively comprise a detecting unit and is electrically connected to The detecting unit is a digital signal processing unit. The optical touch device of claim 1, wherein the optical touch device further comprises a substrate, the frame, the light source module, the first image detecting component, and the second image detecting component And the third image detecting component is disposed on the substrate. The method for positioning an optical touch device is applicable to the optical touch device of claim 1, wherein the method for positioning the optical touch device comprises: a touch device located in the sensing region by the mirror component Forming a virtual image by using the first image detecting component, the second image detecting component, and the third image detecting component to detect a position of a dark spot caused by the touch point to obtain a first optical information. And detecting, by the first image detecting component and the second image detecting component, a position of a dark point caused by the virtual image to obtain a second optical information; and determining, according to the first optical information and the second optical information, The location of the touch point in the sensing area.