TWI657357B - Optical touch device and optical touch method - Google Patents

Abstract

An optical touch device includes an indication plane, an image sensing unit, a mirror, and a processing unit, wherein the processing unit is electrically connected to the image sensing unit. The image sensing unit is disposed on one side of the indication plane. The mirror is disposed adjacent to the image sensing unit. At least a portion of the mirror of the mirror is located within a sensing range of the image sensing unit, and at least a portion of the mirror maps a predetermined range of the indicating plane. The image sensing unit senses an image of one of the objects on the indicating plane, wherein the image includes a mirror image region from at least a portion of the mirror and a non-mirror image region. The processing unit determines whether an object exists in the mirror image area. When the processing unit determines that an object exists in the mirror image area, the processing unit determines that the object is within a predetermined range.

Description

Optical touch device and optical touch method

The present invention relates to an optical touch device and an optical touch method, and more particularly to an optical touch device and an optical touch method for determining whether an object is too close to the image sensing unit.

At present, the optical touch device has advantages of lower cost and easier achievement than other touch technologies, such as resistive, capacitive, ultrasonic or projected image, especially in the field of large-sized touch display. The conventional optical touch device utilizes an image sensing unit to sense an object (eg, a finger or a stylus) at a touched position indicated on the indication plane. When the image sensing unit senses the object on the indication plane, the processing unit of the optical touch device can calculate the touch position indicated by the object. However, when the object is too close to the image sensing unit, the object in the image sensed by the image sensing unit may become very large, which may cause trouble in the recognition of the touch position.

One of the objectives of the present invention is to provide an optical touch device and an optical touch method that can determine whether an object is too close to the image sensing unit to solve the above problem.

According to an embodiment, the optical touch device of the present invention comprises an indication plane, an image sensing unit, a mirror and a processing unit, wherein the processing unit is electrically connected to the image sensing unit. The image sensing unit is disposed on one side of the indication plane. The mirror is disposed adjacent to the image sensing unit. At least a portion of the mirror of the mirror is located within a sensing range of the image sensing unit, and at least a portion of the mirror maps a predetermined range of the indicating plane. The image sensing unit senses an image of one of the objects on the indicating plane, wherein the image includes a mirror image region from at least a portion of the mirror and a non-mirror image region. The processing unit determines whether an object exists in the mirror image area. When the processing unit determines that there is an object in the mirror image area At the time, the processing unit determines that the object is within a predetermined range.

According to another embodiment, the optical touch method of the present invention is applicable to an optical touch device. The optical touch device includes an indication plane, an image sensing unit, and a mirror. The image sensing unit is disposed on one side of the indication plane. The mirror is disposed adjacent to the image sensing unit. At least a portion of the mirror of the mirror is located within a sensing range of the image sensing unit, and at least a portion of the mirror maps a predetermined range of the indicating plane. The optical touch method includes the following steps: the image sensing unit senses an image of an object on the indication plane, wherein the image includes a mirror image region from at least part of the mirror surface and a non-mirror image region; determining whether the mirror image region exists The object; and when it is determined that the object exists in the mirror image area, it is determined that the object is within a predetermined range.

In summary, the present invention places the mirror adjacent to the image sensing unit such that at least part of the mirror surface of the mirror is located within the sensing range of the image sensing unit, and at least part of the mirror surface of the mirror is mapped out of the indicating plane. Scheduled range. When an object exists in the mirror image area of the image sensed by the image sensing unit, the object is located within a predetermined range of the indication plane, indicating that the object is too close to the image sensing unit. In this case, the present invention can reduce the weight of the image when calculating the touch position of the object, or drive the warning unit to send a warning message to prompt the user to perform the touch operation again. Thereby, it can effectively avoid the trouble that the object is located too close to the image sensing unit and the touch position is troubled.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

1‧‧‧Optical touch device

3‧‧‧ objects

10‧‧‧ indicating plane

12a-12d‧‧‧Image Sensing Unit

14‧‧‧Processing unit

16‧‧‧Warning unit

18‧‧‧Mirror

180‧‧‧Mirror

A1, A2‧‧‧ area

D‧‧‧Predetermined range

I‧‧‧ images

I1‧‧‧Mirror image area

I2‧‧‧Non-mirror image area

W1‧‧‧ first width

W2‧‧‧ second width

S10-S22‧‧‧Steps

FIG. 1 is a schematic diagram of an optical touch device according to an embodiment of the invention.

FIG. 2 is a functional block diagram of an optical touch device according to an embodiment of the invention.

3 is a partial side elevational view of an optical touch device in accordance with an embodiment of the present invention.

Figure 4 is a schematic diagram of the image sensed by the image sensing unit in Figure 3.

Figure 5 is a side elevational view of the object of Figure 3 within a predetermined range of the indication plane.

FIG. 6 is a schematic diagram of an image sensed by the image sensing unit in FIG. 5.

Fig. 7 is another side view of the object in Fig. 3 located within a predetermined range of the indication plane.

FIG. 8 is a schematic diagram of an image sensed by the image sensing unit in FIG. 7.

FIG. 9 is a flow chart of an optical touch method according to an embodiment of the invention.

Please refer to FIG. 1 to FIG. 4 , FIG. 1 is a schematic diagram of an optical touch device 1 according to an embodiment of the invention, and FIG. 2 is a functional block diagram of an optical touch device 1 according to an embodiment of the invention. 3 is a partial side view of the optical touch device 1 according to an embodiment of the invention, and FIG. 4 is a schematic view of the image I sensed by the image sensing unit 12a in FIG.

As shown in FIG. 1 , the optical touch device 1 includes an indication plane 10 and four image sensing units 12a-12d, wherein each of the image sensing units 12a-12d is respectively disposed at a corner of one side of the indication plane 10. In practical applications, the indication plane 10 can be a display panel (eg, a liquid crystal display panel), a whiteboard, a blackboard, a projection screen, or other plane for the user to perform a touch operation; the image sensing units 12a-12d can be charge coupled components. (Charge-coupled Device, CCD) sensor or Complementary Metal-Oxide Semiconductor (CMOS) sensor, but not limited to this. In practical applications, a light source (for example, a light emitting diode) may be disposed beside the image sensing units 12a-12d, or a light bar may be disposed around the indicating plane 10 to provide light required for general touch operation. . When a light source is disposed beside the image sensing units 12a-12d, a reflective border or a light absorbing border may be disposed around the indicating plane 10, depending on the actual application.

As shown in FIG. 2, the optical touch device 1 further includes a processing unit 14 and an alert unit 16, wherein the processing unit 14 is electrically connected to the image sensing units 12a-12d and the alert unit 16. In a practical application, the processing unit 14 may be a processor or controller having a data operation/processing function; the alert unit 16 may be an alarm. In general, the optical touch device 1 also has soft and hard components necessary for operation, such as Circuit boards, power supplies, applications, communication modules, etc., depending on the application.

As shown in FIG. 3, the optical touch device 1 further includes a mirror 18 disposed adjacent to the image sensing unit 12a. In this embodiment, the mirror 18 can be disposed above the image sensing unit 12a and the mirror 180 of the mirror 18 faces the indicating plane 10 at an oblique angle such that at least a portion of the mirror 180 of the mirror 18 is located in the image sensing unit 12a. Within one of the sensing ranges, and at least a portion of the mirror 180 of the mirror 18 maps out a predetermined range D of the indicator plane 10. It should be noted that, in addition to the image sensing unit 12a, the mirrors 18 are respectively disposed above the other image sensing units 12b-12d, wherein the mirror 18 is disposed as shown in FIG. 3, and is no longer Narration.

As shown in FIG. 3, the user can perform a touch operation on an indication plane 10, wherein the object 3 can be a finger, a stylus or other touch object. At this time, the image sensing units 12a-12d sense an image of the object 3 on the indication plane 10. Taking the image sensing unit 12a as an example, the image I sensed by the image sensing unit 12a is as shown in FIG. 4, wherein the image I includes a mirror image area I1 and a non-image from at least part of the mirror 180 of the mirror 18. Mirror image area I2.

Next, the processing unit 14 determines whether the object 3 exists in the mirror image area I1 of the image I. As shown in FIGS. 3 and 4, since the object 3 is located outside the predetermined range D of the indication plane 10, at least a portion of the mirror 180 of the mirror 18 does not map the object 3, and therefore, the mirror image area I1 of the image I is There is no object 3. When the processing unit 14 determines that the object image 3 is not present in the mirror image area I1 of the image I, the processing unit 14 determines that the object 3 is outside the predetermined range D of the indication plane 10, indicating that the object 3 is not too close to the image sensing unit 12a. At this time, the processing unit 14 can calculate the touch position of the object 3 according to the image sensed by the image sensing units 12a-12d by a general touch algorithm to perform a corresponding touch function.

Please refer to FIG. 5 and FIG. 6. FIG. 5 is a side view of the object 3 in the third figure in a predetermined range D of the indication plane 10, and FIG. 6 is a view of the image sensing unit 12a in FIG. A schematic diagram of the image I to. As shown in FIGS. 5 and 6, since the object 3 is located within the predetermined range D of the indication plane 10, at least a portion of the mirror 180 of the mirror 18 maps the object 3, and therefore, the mirror image area I1 of the image I exists. 3. When the processing unit 14 determines that the object 3 exists in the mirror image area I1 of the image I, the processing unit 14 determines that the object 3 is located within the predetermined range D of the indication plane 10, indicating that the object 3 is too close to the image sensing unit 12a. At this time, the processing unit 14 can reduce the weight of the image I used to calculate one of the touch positions of the object 3 to avoid the trouble that the object 3 is too close to the image sensing unit 12a to recognize the touch position.

In this embodiment, when the object 3 is present in the mirror image area I1 of the image I sensed by the image sensing unit 12a, the weights of the image sensing units 12a-12d can be set as shown in Table 1 below. As shown in Table 1, since the object 3 is not present in the mirror image area of the image sensed by the image sensing unit 12b-12d, the weights of the image sensing units 12b-12d can be set to the same ratio, and only the image sense is lowered. The weight of the unit 12a is measured. It should be noted that the reduced ratio may be determined according to the practical application, and is not limited to the embodiment shown in Table 1.

In addition, when the processing unit 14 determines that the object 3 is located within the predetermined range D of the indication plane 10, the processing unit 14 can calculate a first width W1 of the object 3 in the mirror image area I1, and calculate the object 3 in the non-mirror image area I2. One of the second widths W2, and calculates a ratio W1/W2 of the first width W1 and the second width W2. Then, the processing unit 14 can adjust the weight of the image sensing unit 12a according to the ratio W1/W2.

For example, the present invention can set a plurality of predetermined threshold ranges, and each predetermined threshold range corresponds to one of a plurality of predetermined weights. After calculating the above ratio W1/W2, processing unit 14 may further compare ratio W1/W2 with a plurality of predetermined threshold ranges. When the processing unit 14 determines that the ratio W1/W2 falls within one of the plurality of predetermined threshold ranges, the processing unit 14 sets the weight of the image to a predetermined weight corresponding to the predetermined threshold range.

Please refer to FIG. 7 and FIG. 8. FIG. 7 is another side view of the object 3 in the third figure in the predetermined range D of the indication plane 10, and FIG. 8 is the image sensing unit 12a in FIG. A schematic representation of the image I sensed. As shown in FIGS. 5 to 8, as the object 3 is closer to the image sensing unit 12a, the ratio W1/W2 is larger. Therefore, according to the ratio of the ratio W1/W2, the present invention can know the relative distance between the object 3 and the image sensing unit 12a in advance, and then set a plurality of predetermined threshold ranges according to the relative distance between the object 3 and the image sensing unit 12a. The predetermined range D of the indication plane 10 is further divided into a plurality of regions.

As shown in FIGS. 5 and 7, the present invention can further divide the predetermined range D of the indication plane 10 into the area A1 and the area A2. In addition, the present invention can set the predetermined threshold range of the corresponding area A1 to be K0-K1 and its predetermined weight to be X1, and set the predetermined threshold range of the corresponding area A2 to be K1-K2 and its predetermined weight is X2, wherein the predetermined weight X2 Less than the predetermined weight X1. When the processing unit 14 determines that the ratio W1/W2 falls within the predetermined threshold range K0-K1, the processing unit 14 sets the weight of the image to a predetermined weight X1 corresponding to the predetermined threshold range K0-K1; when the processing unit 14 determines the ratio W1/ When W2 falls within the predetermined threshold range K1-K2, the processing unit 14 sets the weight of the image to a predetermined weight X2 corresponding to the predetermined threshold range K1-K2. In other words, when the object 3 is closer to the image sensing unit 12a, the weight of the image of the image sensing unit 12a is lowered to reduce the influence of the image sensing unit 12a on the recognition of the touch position.

It should be noted that the above-mentioned predetermined threshold range and the number and value of the predetermined weight may be determined according to the actual application, and are not limited to the above embodiments.

When the processing unit 14 determines that the object 3 is located within the predetermined range D of the indication plane 10, in addition to reducing the weight of the image of the image sensing unit, the processing unit 14 may also drive the alert unit 16 to issue a warning message to prompt the user object 3 It is too close to the image sensing unit, and the touch operation needs to be performed again to avoid the trouble that the object 3 is too close to the image sensing unit to recognize the touch position. In this embodiment, the warning message may be light, sound, text, image, vibration, or a combination thereof, depending on the actual application.

Please refer to FIG. 9. FIG. 9 is a flow chart of an optical touch method according to an embodiment of the invention. The optical touch method in FIG. 9 can be implemented by using the optical touch device 1 described above. First, execute In step S10, the image sensing units 12a-12d sense the image I of the object 3 on the pointing plane 10, wherein the image I comprises a specular image area I1 and at least a non-specular image area I2 from at least a portion of the mirror 180 of the mirror 18. Next, step S12 is performed to determine whether the object 3 exists in the mirror image area I2 of the image I. When it is determined that the object image 3 is not present in the mirror image area I2 of the image I, step S14 is performed to calculate the touch position of the object 3 by a general touch algorithm. When it is determined that the object 3 exists in the mirror image area I2 of the image I, step S16 is performed to determine that the object 3 is located within the predetermined range D of the indication plane 10. When it is determined that the object 3 is located within the predetermined range D of the indication plane 10, step S18 is performed to reduce the weight of the image I for calculating the touch position of the object 3. Then, step S20 is performed to calculate the touch position of the object 3 by a general touch algorithm. In another embodiment, when it is determined that the object 3 is located within the predetermined range D of the indication plane 10, step S22 may also be performed to issue a warning message.

It should be noted that the detailed embodiments of the optical touch method of the present invention are as described above, and are not described herein again. In addition, each part or function in the control logic of the optical touch method shown in FIG. 9 can be realized by a combination of hardware and software.

In summary, the present invention places the mirror adjacent to the image sensing unit such that at least part of the mirror surface of the mirror is located within the sensing range of the image sensing unit, and at least part of the mirror surface of the mirror is mapped out of the indicating plane. Scheduled range. When an object exists in the mirror image area of the image sensed by the image sensing unit, the object is located within a predetermined range of the indication plane, indicating that the object is too close to the image sensing unit. In this case, the present invention can reduce the weight of the image when calculating the touch position of the object, or drive the warning unit to send a warning message to prompt the user to perform the touch operation again. Thereby, it can effectively avoid the trouble that the object is located too close to the image sensing unit and the touch position is troubled.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

Claims (12)

An optical touch device includes: an indicating plane; an image sensing unit disposed on one side of the indicating plane; a mirror disposed outside the indicating plane and adjacent to the image sensing unit, the mirror At least part of the mirror surface is located in a sensing range of the image sensing unit, the at least part of the mirror surface is mapped to a predetermined range of the indication plane; and a processing unit is electrically connected to the image sensing unit; wherein the image sensing The measuring unit senses an image of an object on the indication plane, the image includes a mirror image area from the at least part of the mirror surface and a non-mirror image area, and the processing unit determines whether the object exists in the mirror image area. When the processing unit determines that the object exists in the mirror image area, the processing unit determines that the object is within the predetermined range. The optical touch device of claim 1, wherein when the processing unit determines that the object is within the predetermined range, the processing unit lowers the image to calculate one of the weights of the touch position of the object. The optical touch device of claim 2, wherein when the processing unit determines that the object is within the predetermined range, the processing unit calculates a first width of the object in the specular image area, and calculates the object in the non- a second width in the mirror image area, and calculating a ratio of the first width to the second width, the processing unit adjusting the weight according to the ratio. The optical touch device of claim 3, wherein the processing unit compares the ratio with a plurality of predetermined threshold ranges, each of the predetermined threshold ranges corresponding to one of a plurality of predetermined weights, when the processing unit determines that the ratio falls within the When the plurality of predetermined threshold ranges are in one of the ranges, the processing unit sets the weight of the image to the predetermined weight corresponding to the predetermined threshold range. The optical touch device of claim 1, further comprising a warning unit electrically connected to The processing unit, when the processing unit determines that the object is located within the predetermined range, the processing unit drives the alert unit to issue a warning message. The optical touch device of claim 1, wherein the mirror is disposed above the image sensing unit and the mirror surface of the mirror faces the indicating plane at an oblique angle. An optical touch device is applicable to an optical touch device. The optical touch device includes an indication plane, an image sensing unit, and a mirror. The image sensing unit is disposed on one side of the indication plane, and the reflection is The mirror is disposed outside the indicating plane and adjacent to the image sensing unit, and at least part of the mirror surface of the mirror is located in a sensing range of the image sensing unit, the at least part of the mirror mapping a predetermined range of the indicating plane, The optical touch method includes the following steps: the image sensing unit senses an image of an object on the indication plane, wherein the image includes a mirror image region from the at least part of the mirror surface and a non-mirror image region; Whether the object exists in the mirror image area; and when it is determined that the object exists in the mirror image area, determining that the object is within the predetermined range. The optical touch method of claim 7, further comprising the step of: reducing the image to calculate a weight of one of the touch positions of the object when the object is determined to be within the predetermined range. The optical touch method of claim 8, further comprising the steps of: calculating a first width of the object in the specular image area when the object is determined to be within the predetermined range, and calculating the object in the non-specular image a second width in the region, and calculating a ratio of the first width to the second width; and adjusting the weight according to the ratio. The optical touch method of claim 9, further comprising the steps of: comparing the ratio with a plurality of predetermined threshold ranges, each of the predetermined threshold ranges corresponding to a plurality of predetermined weights One of them; and when it is determined that the ratio falls within one of the plurality of predetermined threshold ranges, the weight of the image is set to the predetermined weight corresponding to the predetermined threshold range. The optical touch method of claim 7, further comprising the step of: issuing a warning message when determining that the object is within the predetermined range. The optical touch method of claim 7, wherein the mirror is disposed above the image sensing unit and the mirror surface of the mirror faces the indicating plane at an oblique angle.