Optical touch system and electronic apparatus including the same

An optical touch system includes a touch surface having a first touch region and a second touch region, a reflective member for generating a reflection of an object on the touch surface, an image sensor for providing an image of the object and an image of the reflection, and a processing unit. The image sensor is represented by either first reference coordinate data or second reference coordinate data. The processing unit is configured to compute the coordinate data of the object using the first reference coordinate data, the image of the object, and the image of the reflection when the object is in the first touch region, and configured to compute the coordinate data of the object using the second reference coordinate data, the image of the object, and the image of the reflection when the object is in the second touch region.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on, and claims priority from, Taiwan Patent Application Ser. No. 100127927, filed on Aug. 5, 2011, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to an optical touch system and an electronic apparatus comprising the same.

2. Related Art

FIG. 1shows a current optical touch screen system1disclosed in U.S. Pat. No. 4,782,328. As shown inFIG. 1, the optical touch screen system1comprises two image sensors11configured to capture the image of an object13on a touch screen12. The processor14is coupled with the two image sensors11for processing the images from the two image sensors11to decide sensing paths15respectively connecting the object13and the two image sensors11, and calculates the coordinates of the object13using the sensing paths15.

The coordinates of the object13are those of the intersection of the two sensing paths15. The sensing path15is determined by sensing paths16that respectively pass through the corresponding edges of the object13, and the sensing paths16are determined by the edges of the dark image of the object13captured by the image sensor11. The detailed calculation method is disclosed in U.S. Pat. No. 4,782,328, which is incorporated herein by reference.

FIG. 2shows another current optical touch screen system2. U.S. Pat. No. 7,689,381 B2 (or counterpart Taiwan Publication Patent No. 201003477) discloses an optical touch screen system 2. The optical touch screen system2comprises a mirror21, two light sources22, an image sensor23, and a processor24. The mirror21and the two light sources22are disposed at the periphery of a touch area. The mirror21is configured to generate a reflection26of an object25. The image sensor23is configured to generate an image of the object25and an image of the reflection26. The processor24determines the coordinates of the object25according to the image of the object25and the image of the reflection26.

The processor24determines a sensing path27passing through the image of the object25and another sensing path27passing through the image of the reflection26. The sensing paths27can be determined by the calculation method disclosed in U.S. Pat. No. 4,782,328. Next, the coordinates (x, y) of the object25can be calculated by equations (1) and (2) as follows:

where L is the distance between the mirror21and the edge of a touch area opposite to the mirror21; θ1and θ2are the included angles between a sensing path and an edge of the touch area.

SUMMARY

One embodiment of the present invention provides an optical touch system comprising a touch surface, a reflective member, an image sensor, and a processing unit. The touch surface comprises a first touch region and a second touch region. The reflective member is configured to generate a reflection of an object on the touch surface. The image sensor is configured to provide an image of the object and an image of the reflection, wherein the image sensor is represented by either first reference coordinate data or second reference coordinate data. The processing unit is configured to compute coordinate data of the object using the first reference coordinate data, the image of the object and the image of the reflection when the object is in the first touch region. The processing unit is also configured to compute the coordinate data of the object using the second reference coordinate data, the image of the object, and the image of the reflection when the object is in the second touch region.

Another embodiment of the present invention discloses an optical touch system comprising a touch surface, an image sensor, and a processing unit. The touch surface comprises a first touch region and a second touch region. The image sensor is configured to generate at least one image of an is object. The image sensor can be represented by either first reference coordinate data or second reference coordinate data. The processing unit is configured to select either the first reference coordinate data or the second reference coordinate data as predetermined coordinate data according to the object being in either the first touch region or the second touch region.

One embodiment of the present invention discloses an electronic apparatus comprising an optical touch system and a display device. The optical touch system comprises a touch surface, an image sensor, and a processing unit. The touch surface comprises a first touch region and a second touch region. The image sensor is configured to generate at least one image of an object. The processing unit is configured to compute coordinate data according to the at least one image of the object. The display device is disposed adjacent to the optical touch system. The display device is configured to provide first display content in the first touch region and second display content in the second touch region. The electronic apparatus is configured to control the first display content in the first touch region or the second display content in the second touch region according to the coordinate data of the object.

Another embodiment of the present invention discloses an optical touch system that comprises a touch surface, an image sensor, and a processing unit. The touch surface comprises a first touch region and a second touch region. The image sensor is configured to generate at least one image of an object. The processing unit is coupled with the image sensor and configured to output coordinate data of the object when the object is in the first touch region and to output a gesture event when the object is in the second touch region.

Another embodiment of the present invention discloses an optical touch system that comprises at least one image sensor and a processing unit. The at least one image sensor is configured to generate a picture comprising at least one image of an object. The at least one image sensor can be represented by either first reference coordinate data or second reference coordinate data. The processing unit is configured to determine a distance between the image of the object and a predetermined boundary of the picture, and to use the first reference coordinate data as predetermined coordinate data when the distance is greater than a threshold value.

To provide a better understanding of the above-described objectives, characteristics and advantages of the present invention, a detailed explanation is provided in the following embodiments with references to the drawings.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

The following description is presented to enable any person skilled in the art to make and use the disclosed embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the disclosed embodiments. Thus, the disclosed embodiments are not limited to the embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein.

FIG. 3is an illustration schematically depicting an optical touch system3according to one embodiment of the present invention.FIG. 4is an illustration schematically depicting a picture generated by an image sensor according to one embodiment of the present invention. Referring toFIGS. 3 and 4, the optical touch system3comprises a touch surface31, a reflective member36, an image sensor39, and a processing unit40. The touch surface31can be defined by a first edge32, a second edge33, a third edge34, and a fourth edge35. The reflective member36is disposed adjacent to the third edge34and configured to create a reflection38of an object37on the touch surface31. The image sensor39is configured to generate a picture4, as shown inFIG. 4, which may comprise an image41of the object37and an image42of the reflection38. In the present embodiment, the image sensor39is disposed near the corner of the touch surface31opposite to the reflective member36.

In one embodiment, the reflective member36comprises a mirror.

In one embodiment, the optical touch system3further comprises two light providing members45and46that may be respectively disposed adjacent to the first edge32and the second edge33. The light providing members45and46are configured to provide light for creating the image41of the object37and the image42of the reflection38. The light providing member45or46can be a retro-reflector or mirror, or a linear light source. The linear light source may comprise a plurality of light-emitting elements that can be arranged along the first edge32or the second edge33, or comprise a light guide and a light emitting element that provides light propagating in the light guide so as to allow the light guide to emit light over the touch surface31.

In one embodiment, if the light providing members45and46are retro-reflectors, at least one light emitting element is preferably disposed adjacent to the periphery of the touch surface31such that the light providing members45and46can retro-reflect the light from the at least one light emitting element toward the entire touch surface31.

In one embodiment, at least one light emitting element is disposed adjacent to the image sensor39.

Referring toFIGS. 3 and 4, an included angle α between the sensing path61and the first edge32and an included angle β between the sensing path62and the first edge32can be determined according to the image41of the object37and the image42of the reflection38included in the picture4. The sensing path61is a line extending from reference coordinate data toward the object37, and the sensing path62extends from reference coordinate data toward the reflection38. In one embodiment, the sensing path61can extend from the reference coordinate data toward the center of gravity, the central point or an edge of the object37. The sensing path62can extend from the reference coordinate data toward the center of gravity, the central point, or an edge of the reflection38.

After the calculation of the included angles α and β according to the picture4, if the reference coordinate data is (0, 0) and the coordinate data of the object is (xo, yo), the coordinate data (xo, yo) can be computed using the following equations (3) and (4).

If another reference coordinate data (a, b) is used to compute the coordinate data (x, y) of the object37, the following equation (5) is adopted.

It can be seen by comparing the equation (3) and the equation (5) that using different reference coordinate data (0, 0) and (a, b), will result in obtaining different coordinate data of the object37.

Referring toFIG. 3, on the touch surface31, the application of different reference coordinate data to different touch regions as predetermined reference coordinate data can significantly minimize the deviation between computed object coordinate data indicating the location of the object and the position where the object is really located. In the present embodiment, the touch surface31may comprise a first touch region311and a second touch region312, and correspondingly, the optical touch system3comprises first reference coordinate data and second reference coordinate data that can be applied to represent the image sensor39. When the object37is in the first touch region311, the processing unit40can calculate more accurate coordinate data by using the first reference coordinate data, and when the object37is in the second touch region312, the processing unit40can calculate more accurate coordinate data by using the second reference coordinate data.

In one embodiment, the first touch region311can be a primary operating region, and the first reference coordinate data can be a predetermined reference coordinate data. The primary operating region occupies most of the touch surface31. Most touch operations are performed in the primary operating region. In one embodiment, the first reference coordinate data is the origin (0, 0).

In one embodiment, the second touch region312comprises a region extending adjacent to two edges34and35of the touch surface31.

The number of partitioned touch regions is not limited and the number may be determined according to the accuracy requirements for the calculation of the coordinate data of an object. The shapes or areas of partitioned touch regions are not limited.

In one embodiment, the second touch region312has a section3121is that extends by the reflective member36. Because the section3121is close to the reflective member36, the image41of the object37and the image42of the reflection38may be very close to each other, even obscured with each other in a captured image of the image sensor39when the object37is in the section3121. In one embodiment, the image sensor39generates a picture, which is then analyzed by the processing unit40. If the image41of the object37and the image42of the reflection38are merged in a captured image of the image sensor39, the processing unit40uses the second reference coordinate data relating to the second touch region312to calculate the coordinate data of the object37.

The image sensor39generates a picture4. When the object37is close to the fourth edge35, the image41of the object37is close to the origin O of the picture4. In one embodiment, the processing unit40analyzes the picture4to calculate a positional value representing the left boundary411of the image41and a positional value representing the right boundary412of the image41, and to calculate a positional value representing the left boundary421of the image42and a positional value representing the right boundary422of the image42. The processing unit40compares the positional value representing the right boundary412of the image41and the positional value representing the left boundary421of the image42with the threshold value (Th). When a distance between the positional value representing the right boundary412of the image41and the positional value representing the left boundary421of the image42is greater than a threshold value (Th), the processing unit40uses the first reference coordinate data to calculate the coordinate data of the object37. When the processing unit40determines that the distance between the positional value representing the right boundary412of the image41and the positional value representing the left boundary421of the image42is not greater than the threshold value (Th), the processing unit40uses the second reference coordinate data to calculate the coordinate data of the object37.

In one embodiment, the second touch region312has a section3122that extends the fourth edge35extending between the reflective member36and the image sensor39.

In some embodiments of the present invention, the measurements of the positions of an object and the computations of the coordinate data of the object can be comprehensively performed at different locations of the touch surface31such that the deviation is between the computed object coordinate data and the real object coordinate data at each location. Different touch regions can be sectioned out according to the amounts of the deviations, and then, each touch region is assigned suitable reference coordinate data representing the image sensor. With suitable reference coordinate data, the coordinate data of the object in each touch region can be accurately computed. The first and second reference coordinate data can be obtained using the above-described procedures.

Referring toFIGS. 5 and 6, in one embodiment, the optical touch system3may comprise a memory device50coupled with the processing unit40that is connected to the image sensor39, wherein the first reference coordinate data and the second reference coordinate data is stored in the memory device50as shown inFIG. 5. In another embodiment, the image sensor39comprises a controller392, an imaging pixel array391coupled with the controller392, and a register device393connected with the controller392, wherein the first reference coordinate data and the second reference coordinate data is stored in the register device393.

In addition to assigning different reference coordinate data to different touch regions, the deviations between the real position of an object and the computing position of the object can be reduced by adjusting the display content presented by a display device when a fixed reference coordinate data is used to represent the image sensor.

FIG. 7is an illustration schematically depicting an electronic apparatus7according to one embodiment of the present invention. Referring toFIGS. 3 and 7, the electronic apparatus7comprises an optical touch system3as shown inFIG. 3and a display device71disposed adjacent to the optical touch system3. The optical touch system3may comprise a touch surface31, a reflective member36, an image sensor39, and a processing unit40. The display device71shows information and control widgets/icons provided by the electronic apparatus7.

The touch surface31comprises a first touch region311and a second touch region312, and the optical touch system3comprises a first reference coordinate data and a second reference coordinate data corresponding to the first touch region311and the second touch region312. The display device71shows a first display content72in the first touch region311and a second display content73in the second touch region312. The image sensor39captures at least one image of an object. The processing unit40is configured to compute the coordinate data of the object according to the image of the object. The electronic apparatus7controls the first display content72in the first touch region311or the second display content73in the second touch region312according to the computed coordinate data of the object.

In order to accurately calculate coordinate data of the object, the optical touch system3uses the first reference coordinate data when the object is in the first touch region311, and uses the second reference coordinate data when the object is in the second touch region312. As shown inFIG. 7, under some circumstances, the optical touch system3only uses the first reference coordinate data. Since only the first reference coordinate data is used, significant deviations between the actual position of the object and the computed position of the object may occur when the object moves in the second touch region312, causing incorrect operations. In order to avoid incorrect operations, the electronic apparatus7will provide, in the second touch region312, display content that can be correctly manipulated by a user without the requirement of computing accurate positions of the object. For example, scroll bars731are suitable for being used in the second touch region312, or other icons or widgets that can be correctly manipulated by a user without the requirement of accurately computed positions of the object.

Moreover, the electronic apparatus7can provide icons that are larger than those displayed in the first touch region311for the second touch region312as shown inFIG. 7. The larger icons allow using inaccurately computed coordinate data of an object and can reduce incorrect operations.

FIG. 8is an illustration schematically depicting display content72′ shown in the first touch region311and display content73′ shown in the second touch region312according to another embodiment of the present invention. As shown inFIG. 8, in one embodiment, the optical touch system3may only use the second reference coordinate data to calculate the coordinate data of an object. Since only the second reference coordinate data is used, significant deviations between the actual position of the object and the computed position of the object may occur when the object moves in the first touch region311, causing incorrect operations. In order to avoid incorrect operations, the electronic apparatus7will provide, in the first touch region311, display content that can be correctly manipulated by a user without the requirement of computing accurate positions of the object. For example, icons or widgets that can be correctly manipulated by a user without the requirement of computing accurate positions of the object are provided in the first touch region311; or icons that are larger than those displayed in the second touch region312are provided in the first touch region311as shown inFIG. 8.

FIG. 9is an illustration schematically depicting display content91shown in the first touch region311and display content92shown in the second touch region312according to another embodiment of the present invention.FIG. 10is an illustration schematically depicting display content91′ shown in the first touch region311and display content92′ shown in the second touch region312according to another embodiment of the present invention. As shown inFIG. 9, in addition to icons or widgets, the display device71of the electronic apparatus7may show information such as email content or list items. When the optical touch system3uses the first reference coordinate data to calculate the coordinate data of an object, the formation can be more compact because the coordinate data of the object moving in the first touch region311can be accurately calculated. As shown inFIG. 10, when the optical touch system3uses the second reference coordinate data to calculate the coordinate data of an object, less dense information is presented in the first touch region311because accurately computed coordinate data of the object in the first touch region311cannot be easily obtained. As such, inaccurately computed coordinate data of the object become acceptable and incorrect operations can accordingly be reduced. As shown inFIGS. 9 and 10, when the optical touch system3changes the use of the first reference coordinate data to the use of the second reference coordinate data, the list items in the first touch region311are widened.

FIG. 11is a block diagram illustrating an electronic apparatus7according to one embodiment of the present invention. As shown inFIG. 11, the electronic apparatus7may comprise a processor111, a memory device112, an optical touch system3, and a display device71. The processor111is configured to process programs for operating the electronic apparatus7. For example, the processor111may control the first display content72presented in the first touch region311or the second display content73presented in the second touch region312according to the calculated coordinate data of an object. The memory device112stores programs and data used for the operation of the electronic apparatus7.

FIG. 12is a flow chart demonstrating the steps of a method of calculating coordinate data of an object in an optical touch system according to one embodiment of the present invention. As shown inFIG. 12, in Step S1201, a touch surface is configured as including a first touch region and a second touch region, wherein the second touch region comprises a region extending adjacent to two edges of the touch surface opposite to the image sensor.

In Step S1202, first reference coordinate data is assigned for use in the calculation of the coordinate data of an object in the first touch region, and second reference coordinate data is assigned for use in the calculation of the coordinate data of an object in the second touch region.

In Step S1203, an image sensor generates a picture that may comprise an image of an object and an image of a reflection of the object.

In Step S1204, the number of individual images in the picture is calculated, and the positional value representing the right boundary of the image of the object and the positional value representing the left boundary of the image of the reflection are calculated.

In Step S1205, while determining whether the number of individual images is equal to two, if the number of individual images is not equal to two, then the object is considered as being in the second touch region, and the second reference coordinate data is selected as the predetermined reference coordinate data (Step S1206).

In Step S1207, the distance between the positional value representing the right boundary of the image of the object and the positional value representing the left boundary of the image of the reflection of the object is compared with the threshold value. If the distance between the positional value representing the right boundary of the image of the object and the positional value representing the left boundary of the image of the reflection is not greater than the threshold value, the second reference coordinate data is selected as the predetermined reference coordinate data (Step S1206). If the distance between the positional value representing the right boundary of the image of the object and the positional value representing the left boundary of the image of the reflection is greater than the threshold value, the first reference coordinate data is selected as the predetermined reference coordinate data (Step S1208).

In Step S1209, the predetermined reference coordinate data is used to calculate the coordinate data of the object.

As shown inFIG. 13, the optical touch system8can be disposed on a display device9. The optical touch system8may comprise a touch surface31, an image sensor39, and a processing unit40. The touch surface31may comprise a first touch region311and a second touch region312. The image sensor39is configured to capture at least one image of an object13a,23bor13c. The processing unit40is coupled with the image sensor39and configured to calculate the coordinate data of an object using the at least one image. The processing unit40is further configured to output coordinates of the object13cwhen an analysis shows that the object13cappears in the first touch region311or the primary operating region. The processing unit40is further configured to output a gesture performed by an object when an analysis shows that an object13aor13bappears in the second touch region312.

In one embodiment, the processing unit40is configured to provide a command according to the above-mentioned gesture, and the command may be used to control the content shown on the display device9.

Specifically, in one embodiment, when the processing unit40identifies that the object13ais in the second touch region312, the processing unit40may calculate the coordinate data of the object13aover a predetermined time period during which the object13amoves, and determines which gesture a user performs according to the coordinate data. For example, if the coordinate data calculated by the processing unit40indicates that the object13agradually moves to the left, the processing unit40then determines that the object13aperforms a gesture of moving left as indicated by an arrow133. If the coordinate data calculated by the processing unit40indicates that the object13agradually moves to the right, the processing unit40then determines that the object13aperforms a gesture of moving right as indicated by an arrow134. If the coordinate data calculated by the processing unit40indicates that the object13agradually moves upward, the processing unit40then determines that the object13aperforms a gesture of moving upward as indicated by an arrow131. If the coordinate data calculated by the processing unit40indicates that the object13agradually moves downward, the processing unit40then determines that the object13aperforms a gesture of moving downward as indicated by an arrow132. The definition of the directions in the above embodiments is as an example. The present invention is not limited to such definition.

The coordinate data of the object13amay not only change linearly, but also change curvedly. For example, if the coordinate data of the object13bcalculated by the processing unit40sequentially forms a curve oriented counterclockwise, the object13bperforms a gesture of rotating counterclockwise as indicated by an arrow135. If the coordinate data of the object13bcalculated by the processing unit40sequentially forms a curve oriented clockwise, the object13bperforms a gesture of rotating counterclockwise as indicated by an arrow136.

With different gestures, the processing unit40may output different events. For example, a linearly moving gesture may initiate a Move event. A curved gesture may initiate a Rotate event. The optical touch system8can be customized according to operational requirements, configured as having different events corresponding to different gestures to meet the operational requirements.

Gestures can be determined by analyzing the trend of the change of continuously obtained coordinate data of an object. For example, if continuously obtained coordinate data shows a trend of moving along a direction, it can be determined that the object moves along that direction. If continuously obtained coordinate data shows a trend of moving curvedly, it can be determined that the object performs a rotating gesture.

In addition, a gesture can be determined by a change of successive vectors. For example, a first vector representing an object moving from a first time to a second time, a second vector representing the object moving from a second time to a third time, and a third vector representing the object moving from a third time to a fourth time can all be determined according to the received object images. Next, the successive changes of the first, second, and third vectors can be determined. Finally, the successive changes are used to determine which gesture is performed. The method of calculating vectors of a moving object used in current optical touch systems can be applied. The details are not described to avoid a redundant description.

Referring toFIGS. 14 and 15, the optical touch system5comprises at least one image sensor39and a processing unit40. The at least one image sensor39may generate a picture10comprising at least one object image103. The at least one image sensor39can be represented by a first reference coordinate data or a second reference coordinate data, wherein the first reference coordinate data corresponds to the primary operating region, and the second reference coordinate data corresponds to the region other than the primary operating region. The processing unit40is coupled with the image sensor39. The processing unit40is configured to determine a distance L1or L2between a predetermined boundary101or102of the picture10and the object image103. When the distance L1or L2is greater than a threshold T1or T2, the processing unit40uses the first reference coordinate data as predetermined reference coordinate data.

In one embodiment, the predetermined boundary101or102is the left boundary or right boundary of the picture10.

It will be apparent to those skilled in the art that various modifications can be made to the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with the true scope of the disclosure being indicated by the following claims and their equivalents.