Patent Application
20110199339
A “touchscreen” is a display that can detect and locate an object, such as a finger, touching a display screen. Touchscreen capabilities can be enabled by a range of technologies including resistive, surface acoustic wave, capacitive, infrared, strain gage, diffused laser imaging, optical imaging, dispersive signal technology, and acoustic pulse recognition. A touchscreen allows user input without requiring a separate device such as a mouse or trackpad. Unlike those devices, a touchscreen enables a user to interact with what is displayed directly on the screen, where it is displayed, rather than indirectly.
To leverage the economies of scale associated with the manufacture of non-touchscreen LCD displays, some touchscreen displays are manufactured by adding a touchscreen add-on to a conventional LCD display. For example, a conventional LCD screen can be overlaid with an assembly including a glass plate having cameras mounted on its corners. Camera alignment is critical and care must be taken to prevent condensation from forming between the display screen and the glass overlay both during manufacture and during use. Strict tolerances and a cleanroom assembly line are required and account for much of the cost of a touchscreen display. Even with careful camera alignment during manufacture, movement of cameras when the glass is deformed under the pressure of a touch can impair functionality.
The features and advantages of the invention as well as additional features and advantages thereof will be more clearly understood hereinafter as a result of a detailed description of a preferred embodiment of the invention when taken in conjunction with the following drawings in which:
The embodiments described herein provide for a metal frame with camera-emitter assemblies pre-attached. There is no glass panel overlaying the display screen; rather, the display screen itself can serve as a touch surface. The resulting touchscreen add-on is lighter and requires less material than a glass-based touchscreen add-on. More importantly, the area over the display screen is not covered, so there is no problem with condensation forming between the display screen and an overlying glass plate during or after manufacture. Furthermore, since the camera assemblies are attached to the metal frame, they are not displaced when touching deforms the display surface.
A display system API in accordance with an embodiment of the invention is shown in
Touchscreen add-on 13, shown separately in
As shown in
As indicated in
The camera-emitter assemblies 33, 201, 301, and 401 of
In use, each emitter 45 directs IR light 47 from its housing 25 toward opposing sides of bezel 27, as shown
The technology described herein provides for a method ME1, flow charted in
At step S2, camera-emitter assemblies are attached to the frame. Screws can extend through unthreaded holes in either the camera-emitter assemblies or in the frame and extend into threaded holes in the other component. Alternatively, camera-emitter assemblies can be attached to he housings and thus the frame using glue or double-sided tape. In addition, retroreflective material can be applied to the bezel rendering it retroreflective. The result of step S21 is a touchscreen add-on assembly.
At step S3, the touchscreen add-on assembly is attached to a display, e.g., using glue 37 (
At step S4, a video or still presentation image is presented on a display screen of a display. The presentation image can be provided by a computer, for example. The computer can be a separate entity. Alternatively, a display system can be an all-in-one computer in which data and image processing is performed using computer components built into the back of a display housing.
At step S5, a user controls the presentation image by imposing one or more objects, e.g., a finger in contact with or sufficiently proximate to a display screen that h blocks emitted and/or reflected light from being detected by a camera. The resulting images (from plural cameras) can b analyzed to determine object position and gestures. This interpretation can be used, e.g., by an operating system or an application program, to control the presentation image.
Herein, an “imaging system” is a system that generates, captures, and/or displays images. An “object locating system” is a system, such as touchscreen add-on 13, that locates an object within a given area or volume, such as the volume near a display screen and within a frame. A “frame” is used for visually demarking a viewing area defined by an aperture defined and surrounded by the frame. A typical frame is generally planar and rectangular and has a rectangular viewing aperture. However, frames and their apertures can have a wide variety of two-dimensional shapes, including circles, ovals, ellipses, that do not have corners, and any polygonal shape.
A “bezel” is typically a low-aspect-ratio wall bounding an aperture or recess. In the present case, a bezel extends generally orthogonal to the bulk of the frame, although bezels can extend at other angles as well. “Retroreflective” is a property of a material or surface that reflects light back along the direction from which it came. A mirror only has this property for light that arrives orthogonal to the mirror. A retroreflective material or surface has this property for a range of non-orthogonal angles of incidence.
A “perimeter” is a closed outer boundary. In the present case, the perimeter of the aperture defined by the frame is of interest as the location of the retroreflective bezel. A “camera” is a device that captures images of one, two, or more spatial dimensions; the cameras discussed herein are “video cameras” in that they can produce a series of images that represent motion over a temporal dimension. A typical camera includes an array sensor, with a linear or two-dimensional array of detectors, e.g., a CCD or CMOS sensor. A camera will also typically include a lens or lens assembly for focusing incoming light on the sensor.
An “image” is a pattern of luminance and in some cases color. In the present case, the light source is essentially monochromatic, so an image is a one or two-dimensional spatial distribution of luminance. Still images can be used to detect the location of an object, while moving images can be used to detect: gestures. “Light” herein encompasses visible, ultraviolet, and infrared light.
An “emitter” is a device that emits light. For example, an infrared LED can serve as an emitter. In the illustrated embodiments, the emitters emit infrared light toward the retroreflective bezel. A camera-emitter assembly includes both a camera and an emitter. In the illustrated embodiments, the emitter directs light toward a retroreflective bezel, which reflects the incident light back toward the nearly co-located camera. Objects located in the frame aperture can block emitted light from reaching the bezel and reflected light from returning to the camera. This results in an image in the form of a spatial (still image) or spatial and temporal (video image) light distribution that can be analyzed to locate the object or to identify a gesture.
“Attached” herein means fixed to directly. Object A is attached to object B if A is fixed to B and 1) A is in contact with B, or 2) A and B are both in contact with adhesive material (glue or double-0side tape) used. to fix A to B. A is “rigidly coupled” to B is A's position with respect to B is fixed. A can be rigidly coupled to B without being attached to B, e.g., where they are both attached to an intervening structural member. For example, once the frame of the invention is attached to a display, the camera assemblies are rigidly coupled to the display because both are attached and fixed to the frame. However, the camera-emitter assemblies are not attached to the display.
A “display screen” is a portion of a display on which an image is presented. A display is a device including a display screen. A display may have additional functions, such as sound output from integrated speakers or switches to turn power on and off. “Coextensive” means that their orthogonal projections throughout space are substantially coincident. To put a value on “substantially” in this context, At least 90% of each projection should intersect the other projection. The display and aperture are “aligned” if their orthogonal projections overlap.
“Touchscreen” refers to displays and add-ons therefor that detect and locate an object that is touching a display screen or a window overlaying a display screen. A touchscreen need not rely on touch to trigger detections and may not require actual touching; for this reason, the invention can be considered as directed toward an “object locating system”. A touchscreen or object locating system in accordance with the present invention provides for detecting an object adjacent to but not touching a display screen can be detected.
The foregoing description, for purposes of explanation, has been described with reference to specific embodiments. However, the illustrative discussions are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the disclosed teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2008/081673 | 10/30/2008 | WO | 00 | 4/11/2011 |
