WO2010110681A2

WO2010110681A2 - Frames for optical touch detection systems

Info

Publication number: WO2010110681A2
Application number: PCT/NZ2010/000049
Authority: WO
Inventors: Simon James Bridger; Matthew Allard
Original assignee: Next Holdings Ltd
Priority date: 2009-03-25
Filing date: 2010-03-24
Publication date: 2010-09-30
Also published as: WO2010110681A3

Abstract

A touch detection system can use an assembly comprising a frame adapted for use with a touch surface defining a touch plane, the frame having a top portion, a bottom portion, and two side portions, with a first end of each side portion adjacent the bottom portion and a second end of each side portion adjacent the top portion. Each side portion extends outward from the plane by a respective width that varies along its length, with the width greater at its second end than at its first end. In some embodiments, the frame can comprise a portion that extends outward from the plane, with an outward-facing surface thereof defining a front of the frame. Regardless of whether the width of other portions varies, the portion can comprise a recess having at least one side defined by a step, the step corresponding to the front of the frame.

Description

FRAMES FOR OPTICAL TOUCH DETECTION SYSTEMS

Priority Claim

This application claims priority to Australian provisional patent application number 2009901282, filed March 25, 2009 and entitled "A Frame Incorporating a Reflective Member," which is incorporated by reference herein in its entirety.

This application also claims priority to Australian provisional patent application number 2009901288, filed March 25, 2009 and entitled "A Touch Sensitive Display," which is incorporated by reference herein in its entirety.

Background

[0001] Optical touch systems can be used with a display or another surface defining a touch plane in order to determine the location of a touch or other interaction within a touch-enabled area. An optical touch system functions by having at least one optical sensor that detects light traveling across a surface, such as light emitted over the surface from an infrared or other source. When an object (e.g., a pointer, a finger, etc.) is placed on or near the surface, the object interferes with the light. For example, the sensor can detect when light is partially or fully blocked by the object and a processor can use triangulation or other techniques to determine coordinates of the object.

[0002] An optical touch system may use a frame or bezel that defines an area. For instance, the bezel may extend outward from the display or other touch surface and can be used to position the optical sensor or other components. Some systems use reflective material, such a retroreflective tape or other material, to reflect energy back over the surface in order to improve accuracy of the system. Summary

[0003] The present subject matter can address one problem with certain touch systems, namely that the optical sensors are relatively large in size, which leads to a bezel that extends outward from the touch surface in an unappealing manner. Additionally, the bezel may occlude ambient light and may be difficult to manufacture.

[0004] Presently-disclosed embodiments of a touch detection system can use an assembly comprising a frame adapted for use with a touch surface defining a touch plane, the frame having a top portion, a bottom portion, and two side portions, with a first end of each side portion adjacent the bottom portion and a second end of each side portion adjacent the top portion. Each side portion extends outward from the plane by a respective width that varies along its length, with the width greater at its second end than at its first end. The sides of the frame may thereby define a wedge in some embodiments, though other shapes/profiles may be used to achieve the same effect. By varying the width, the optical component(s) can be accommodated (e.g., at the top of the frame), while using a wedge or tapered shape reduces or avoids problems with prior bezel approaches. Additionally, if a bottom portion of narrower width is used, less dust and other "fluff may accumulate along the bottom edge of the frame.

[0005] Additional embodiments address an issue that has been discovered with respect to reflective material. In some existing designs, the retroreflective material is applied separately, e.g., using tape positioned on supports. The supports may be bonded to the screen, but can tend to separate and otherwise introduce complexity in manufacture.

[0006] In some presently-disclosed embodiments, the frame can comprise a portion that extends outward from the plane, with an outward-facing surface thereof defining a front of the frame. Regardless of whether the wedge/tapered design is used for the other portions, the portion that defines a front of the frame can comprise a recess having at least one side defined by a step, the step corresponding to the front of the frame. Reflective material can be positioned in and/or formed as part of the recess. By applying or including the reflective material in/on the frame itself, manufacture can be simplified. Additionally, use of the step allows for the edge of the reflective material to be partially or completely hidden from view when the frame is viewed from the front, which results in a more attractive end product.

[0007] These illustrative embodiments are mentioned not to limit or define the limits of the present subject matter, but to provide examples to aid understanding thereof. Illustrative embodiments are discussed in the Detailed Description, and further description is provided there, including illustrative embodiments of systems, methods, and computer-readable media providing one or more aspects of the present subject matter. Advantages offered by various embodiments may be further understood by examining this specification and/or by practicing one or more embodiments of the claimed subject matter.

Brief Description of the Drawings

[0008] A full and enabling disclosure is set forth more particularly in the remainder of the specification. The specification makes reference to the following appended figures. [0009] Figure IA is a perspective view of a touch assembly. [0010] Figure IB is a side view of the assembly of Figure IA. [0011] Figure 1C is a side view of the assembly of Figures 1A-1B and illustrating an example of positioning a touch surface relative to the assembly.

[0012] Figure ID shows a plurality of example profiles that can be used in addition to or instead of a wedge-shaped profile. [0013] Figure 2 is a perspective view of a touch assembly along with sensors of a touch detection system.

[0014] Figure 3 is a perspective view of a portion of a touch assembly with an outward- facing portion and a recess. [0015] Figure 4 is a side view of the portion shown in Figure 3.

Detailed Description

[0016] Reference will now be made in detail to various and alternative exemplary embodiments and to the accompanying drawings. Each example is provided by way of explanation, and not as a limitation. It will be apparent to those skilled in the art that modifications and variations can be made. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that this disclosure includes modifications and variations as come within the scope of the appended claims and their equivalents.

[0017] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter may be practiced without these specific details. In other instances, methods, apparatuses or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure the claimed subject matter. [0018] Figure IA is a perspective view of a touch assembly 10. In this example, assembly 10 comprises a frame adapted for use with a touch surface defining a touch plane, wherein the frame defines an area and comprises a top portion (12), a bottom portion (14), and two side portions (16, 18). In the examples herein, the terms "top" and "bottom" refer to those portions corresponding to the top and bottom of the area defined by the frame when viewed from the front side. In the Figures, the "top" is the y-maximum and the bottom is the y-minimum. The touch surface is generally in the x-y plane.

[0019] Each side portion 16, 18 extends between the top portion 12 and the bottom portion 14 so that a first end (20) of each side portion is adjacent the bottom portion and a second end (22) of each side portion is adjacent the top portion. Each side portion also extends outward from the plane (i.e. in the z+ direction) towards the front of the frame by a respective width that varies along a length of each side portion (i.e., the width varies at different y- coordinates along the side portions). Particularly, the width of each side portion is greater at its second end (22) than at its first end (20)., As shown in Figure IA, distance B is greater than distance A. [0020] The widths of each side portion 16, 18 can be substantially the same at corresponding points along their respective lengths. That is, in some embodiments, for the same y-coordinate, side portion 18 can have a width that is the same as or within a tolerance value as the width of side portion 20. However, in some embodiments, the side portions 16 and 18 could have different widths from one another at the same points along their lengths, for instance to accommodate a design feature or the like.

[0021] Figure IB is a side view of the assembly of Figure IA depicting a profile view of side portion 16. hi this view, it can be seen how the width of side portion 16 is greater at the top (i.e., in area 22 near portion 12) than at the bottom (i.e. area 20, near portion 14). Additionally, the front F of the frame is illustrated for purposes of reference. In this example, side portion 16 forms a "wedge" shape when viewed in profile because the width decreases linearly along the length of the side portion. However, numerous other profiles could be used with the result that the side portion is wider at one end than it is at an opposite end. [0022] Figure 1C is a side view of the assembly of Figures 1 A-IB and illustrating an example of positioning a touch surface relative to the assembly. For example, in Figure 1C, a portion of a display 11 defining the touch surface is shown along with side portion 16 to illustrate how the frame can be fitted to a display. The outer surface of display 11 or a surface overlaid thereon can define the touch surface.

[0023] A wedge-shaped profile is used in some embodiments. However, numerous other profiles could be used with the result that the side portion is wider at one end than it is at an opposite end can be used. For instance, the side portion could taper very gradually from a minimum width near bottom portion 14 and then rapidly increase to reach the width of top . portion 12 or vice-versa — maintaining a greater width and then decreasing to reach the width at the bottom portion 14. For example, the width could remain constant, or vary at a first rate, along 50%, 60%, 70%, 80%, or even 90% of the side portion's length and then transition to another width or rate of variance. The transitions could be continuous (e.g., a curved profile) and/or could be discontinuous (e.g., zig-zag, sawtooth, or stepped profile). [0024] Figure ID shows an example of some profiles that could be used for portion 16 and/or for portion 18 and are briefly described below:

[0025] Figure 2 shows the assembly in perspective along with two optical units 30 and 32. Also visible in the profile view of Figure 1C is one of the optical units 32 as positioned between the top portion of the frame and the touch surface. The optical unit is positioned so that a field of view of the optical unit includes a view of at least a part of bottom portion 14. As noted above, in some embodiments an optical touch detection system can utilize optical units to image light traveling across a touch surface. If no object is in contact with or proximity to the touch surface, then optical unit 32 will view the part of bottom portion 14 facing inward towards the touch area. However, an object interfering with light will be silhouetted on the part facing inward towards the touch area and/or may cast one or more shadows on that part. Additionally or alternatively, the object may emit light or reflect additional light to the sensor than would otherwise be detected.

[0026] In this example, the optical units are positioned to image at least the bottom part of the frame. However, other portions of the frame may be imaged. For instance, each optical unit 30 and 32 may be positioned to image some or all of the side portions in addition to or instead of the bottom portion.

[0027] The portion(s) that are imaged by the optical unit(s) may feature reflective material. For instance, as shown in Figure 3, a reflective material can be positioned on a part of the bottom portion 14. Figure 3 is a detail view of a bottom corner of the frame of Figures 1-2. As can be seen, the bottom portion 14 includes a part that extends outward from the plane and defines a bottom edge of the area, the reflective material positioned on the part that extends outward from the plane. Generally speaking, the reflective material can be positioned to face inward towards the touch area so as to reflect energy traveling across the touch surface. For example, a retroreflective material can be used in some embodiments to return light towards its origin with a minimum amount of diffraction.

[0028] As can be seen in Figure 4, the part of the bottom portion 14 that extends outward from the plane can comprise a recess configured to receive the reflective material 15 along with a step S. The step S can define a side of the recess and can correspond to a front surface (F) of the frame. This feature may reduce or avoid the likelihood that a user will see the edge of the retroreflective material, substantially hiding it from view and leading to a more attractive product. For example, if reflective tape is used, the size of the step S can be substantially the same as the tape thickness (i.e., the same or within a tolerance value). Of course, the size of the step S may be greater than the thickness of the tape and can achieve the same effect, and the advantages may remain even if the tape or other material is slightly thicker than step S. A single recess may be defined for the entire edge or multiple recesses may be used.

[0029] The thickness T of the step can vary as needed to provide a durable product and to accommodate the size of the tape or reflective material. Although tape is discussed in this example, other reflective structures can be used Additionally or alternatively, reflective material may be formed directly in the recess, with a minimal-sized step S used in such cases.

The features noted above with respect to Figures 3 and 4 can be used in a frame in which the side portions vary in width. However, the features may be used in embodiments in which the width of the side portions remains constant.

[0030] For example, in one embodiment a touch assembly comprises a frame adapted for use with a touch surface defining a touch plane, with the frame comprising at least one portion that extends outward from the plane, the portion including an outward-facing surface defining a front of the frame. As noted above, the portion that extends outward from the plane can comprise a recess, the recess having at least one side defined by a step, the step corresponding to the front of the frame. Use of the Touch Assembly

[0031] One or more aspects of the frames discussed herein can be used in conjunction with a computing system. For example, a position detection system can comprise a computing device that monitors a touch area using one or processing devices configured by program components in memory. The processing device may comprise a microprocessor, a digital signal processor, or the like. The processor can monitor the touch area via one or more busses, interfaces, etc. to connect to one or more sensors.

[0032] An embodiment featuring a recess and/or side portions with varying widths as noted above can be fitted to a display or another surface defining the touch surface. Reflective material can be positioned on one or more inward-facing edges, such as in a recess of the bottom portion (and/or another portion) in view of one or more optical units comprising sensors, with the optical units positioned in between the frame and the touch surface. A processing device can be configured to use the optical unit(s) to detect light reflected by the reflective material and to determine a coordinate of an object in the touch area based at least in part on detecting interference with light reflected from the reflective material.

[0033] For example, the processing device may be comprised in a desktop, laptop, tablet, or "netbook" computer, a kiosk, or an interactive whiteboard. However, other examples may comprise a mobile device (e.g., a media player, personal digital assistant, cellular telephone, etc.), or another computing system that includes one or more processors configured to function by program components. The touch area may correspond to a display of the device and may be a separate unit or may be integrated into the same body as computing device. The processing unit that performs the touch detection may be one of several processing units in the computing device. For example, the processor, memory, and 170 interface may be included in a digital signal processor (DSP) that is interfaced as part of an input device used for a computer, mobile device, etc. that utilize a frame configured in accordance with the present subject matter. The CPU of the computer, mobile device, etc. can then use data from the DSP to interpret the touch inputs as clicks, so-called "gestures," and the like.

[0034] Although a touch screen was discussed in examples above, it will be understood that the principles disclosed herein can be applied when a surface separate from the display (e.g., a trackpad) is used for input, or could be applied even in the absence of a display screen when an input gesture is to be detected. For example, the touch area may feature a static image or no image at all.

[0035] The sensor(s) can provide data indicating one or more touch locations relative to a touch surface, and may operate using any number or type of principles. For example, the sensor(s) may, as explained below, comprise one or more optical sensors that can detect the locations of touches, hovers, or other user interactions based on interference with an expected pattern of light and/or by analyzing image content. The sensor(s) may be included in optical units that also include light sources, or separate sources and sensors can be used. [0036] In practice, the processor can identify the one or more touch locations from the sensor data using program components embodied in memory. Particularly, a touch detection module can comprise one or more components that read and interpret data from sensor(s), such as by sampling the sensors and using triangulation techniques to identify one or more touch locations and/or potential touch locations. As another example, if a grid is used, touch locations can be identified from the location(s) at which the grid of light is interrupted. The touch detection module may also perform signal processing routines, such as filtering data from sensors, driving light or other energy sources, and the like.

[0037] Any suitable radiation source can be used. For instance, light emitting diodes (LEDs) may be used to generate infrared (IR) radiation that is directed over one or more optical paths in the detection plane. However, other portions of the EM spectrum or even other types of energy may be used as applicable with appropriate sources and detection systems. The reflective material can comprise any suitable material that reflects energy in a range detectable by the sensor(s).

[0038] The various systems discussed herein are not limited to any particular hardware architecture or configuration. As was noted above, a computing device can include any suitable arrangement of components that provide a result conditioned on one or more inputs. Suitable computing devices include multipurpose and specialized microprocessor-based computer systems accessing stored software, but also application-specific integrated circuits and other programmable logic, and combinations thereof. Any suitable programming, scripting, or other type of language or combinations of languages may be used to construct program components and code for implementing the teachings contained herein.

[0039] The use of "adapted to" or "configured to" herein is meant as open and inclusive language that does not foreclose devices adapted to or configured to perform additional tasks or steps. Additionally, the use of "based on" is meant to be open and inclusive, in that a process, step, calculation, or other action "based on" one or more recited conditions or values may, in practice, be based on additional conditions or values beyond those recited. Headings, lists, and numbering included herein are for ease of explanation only and are not meant to be limiting. [0040] The examples herein depicted optical units positioned at thee top of a frame and a reflective member positioned at least near the bottom of the frame. The same principles could be applied if the situation were reversed, i.e., with cameras at the bottom and reflective member(s) at the top, with the wider portion at the bottom. As another example, the whole arrangement could be rotated 90 or 270 degrees to yield a frame with a top and bottom whose thickness varies moving left to right (or right to left).

[0041] While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.

Claims

What is Claimed:

1. A touch detection assembly comprising: a frame adapted for use with a touch surface defining a touch plane, wherein the frame defines an area and comprises: a top portion, a bottom portion, and two side portions, each side portion extending between the top portion and the bottom portion so that a first end of each side portion is adjacent the bottom portion and a second end of each side portion is adjacent the top portion, wherein each side portion extends outward from the plane by a respective width that varies along a length of each side portion, and. . wherein the width of each side portion is greater at its second end than at its first end.

2. The touch detection assembly set forth in claim 1, wherein the widths of each side portion are substantially the same at corresponding points along their respective lengths.

3. The touch detection assembly set forth in claim 2, further comprising a display, the display defining the touch surface, wherein the frame is fitted to the display.

4. The touch detection assembly set forth in claim 3, further comprising: an optical unit positioned between the top portion of the frame and the display, wherein the optical unit is positioned so that a field of view of the optical unit includes a view of at least a part of the bottom portion.

5. The touch detection assembly set forth in claim 4, further comprising: a reflective material positioned on the bottom portion, wherein the bottom portion includes a part that extends outward from the plane and defines a bottom edge of the area, the reflective material positioned on the part that extends outward from the plane.

6. The touch detection assembly set forth in claim 5, wherein the part of the bottom portion that extends outward from the plane comprises: a recess configured to receive the reflective material, and a step, wherein the step defines a side of the recess and corresponds to a front surface of the frame.

7. The touch detection system set forth in claim 6, wherein the reflective material comprises tape having an edge defining a thickness of the tape, and wherein the size of the step is substantially the same as the thickness of the tape.

8. A touch detection assembly comprising: a frame adapted for use with a touch surface defining a touch plane; and wherein the frame comprises at least one portion that extends outward from the plane, the portion including an outward-facing surface defining a front of the frame, and wherein the portion that extends outward from the plane comprises a recess, the recess having at least one side defined by a step, the step corresponding to the front of the frame.

9. The touch detection assembly set forth in claim 8, further comprising: a reflective material formed integrally with or directly attached to the frame, the reflective material positioned in the recess.

10. The touch detection assembly set forth in claim 9, wherein the reflective material comprises tape having an edge, wherein the step is configured so that the front of the frame substantially hides the edge from view.

11. The touch detection assembly set forth in claim 8, wherein the frame comprises a top portion, a bottom portion, and two side portions, each side portion extending between the top portion and the bottom portion, wherein the assembly comprises an optical unit is positioned between a first one of the portions and the frame and the recess is comprised in a portion of the frame opposite the first one of the portions.

12. The touch detection assembly set forth in claim 8, wherein the frame comprises a top portion, a bottom portion, and two side portions, each side portion extending between the top portion and the bottom portion, and wherein the recess is comprised in at least the bottom portion.

13. The touch detection assembly set forth in claim 8, wherein the frame comprises a top portion, a bottom portion, and two side portions, each side portion extending between the top portion and the bottom portion, and wherein the recess is comprised in a plurality of the portions.

14. The touch detection assembly set forth in claim 8, wherein the frame comprises a top portion, a bottom portion, and two side portions, each side portion extending between the top portion and the bottom portion, wherein each side portion extends outward from the plane by a respective width that varies along its length.

15. The touch detection assembly set forth in claim 14, wherein each side portion extends between the top portion and the bottom portion so that a first end of each side portion is adjacent the bottom portion and a second end of each side portion is adjacent the top portion, and wherein the width of each side portion is greater at its second end than at its first end.

16. A touch detection assembly comprising: a frame adapted for use with a touch surface defining a touch plane, wherein the frame defines an area and comprises: a top portion, a bottom portion, and two side portions, each side portion extending between the top portion and the bottom portion so that a first end of each side portion is adjacent the bottom portion and a second end of each side portion is adjacent the top portion, wherein each side portion extends outward from the plane by a respective width that varies along a length of each side portion, wherein the width of each side portion is greater at its second end than at its first end, wherein at least one of the portions that extends outward from the plane defines an edge of the area, the portion including an outward-facing surface defining a front of the frame, and wherein the portion that extends outward from the plane comprises a recess, the recess having at least one side defined by a step, the step corresponding to the front of the frame.

17. The touch detection assembly set forth in claim 16, further comprising a reflective material formed integrally with or directly attached to the frame and positioned in the recess.

18. The touch detection assembly set forth in claim 17, wherein the reflective material comprises tape having an edge, wherein the step is configured so that the front of the frame substantially hides the edge from view.

19. The touch detection assembly set forth in claim 18, further comprising a display defining the touch surface.

20. The touch detection assembly set forth in claim 19, further comprising a processing device configured to use an optical unit positioned between the frame and the display to detect light reflected by the reflective material and to determine a coordinate of an object in the touch area based at least in part on detecting interference with light reflected from the reflective material.