Patent Application
20100321339
The exemplary and non-limiting embodiments of this invention relate generally to user interface systems, methods, devices and computer programs and, more specifically, relate to touch-sensitive user input devices, such as touch sensitive displays.
This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:
Some currently available flat panel displays have external touch structures to enable a user interface based on a touch input feature. However, the touch structure may be thicker than the display itself. Further, the presence of the touch structure may obstruct a portion of the light emanating from the display, thereby reducing the effectiveness of the display function.
The foregoing and other problems are overcome, and other advantages are realized, by the use of the exemplary embodiments of this invention.
In a first aspect thereof the exemplary embodiments of this invention provide a method that comprises out-coupling infrared (IR) light via a plurality of gratings from a light guide structure towards a surface of a display; in-coupling IR light that returns from at least one object above the surface to the light guide structure via at least the plurality of gratings; detecting the in-coupled IR light along at least one edge of the light guide structure; and determining at least one of a presence and spatial position of the at least one object relative to the surface of the display in accordance with the detected in-coupled IR light.
In a further aspect thereof the exemplary embodiments of this invention provide a display apparatus that comprises a display having a pixelated display surface and an opposed surface and a substantially planar light guide structure having a light emitting surface that is optically coupled to the opposed surface of the display. The light emitting surface of the light guide structure is comprised of an array of gratings arranged as a plurality of sub-arrays of gratings. At least some of the gratings of a given sub-array are configured to emit display light towards the opposed surface of said display, and at least one of the gratings of the given sub-array is configured to emit non-display light towards the opposed surface of the display and to receive non-display light that is at least one of reflected from and scattered by at least one object that is proximate to the pixelated display surface. The display apparatus also comprises a plurality of light sensors that are disposed along at least one edge of the light guide structure and that are configured to detect the received non-display light.
In a still further aspect thereof the exemplary embodiments of this invention provide an apparatus that comprises a display unit comprising a pixelated display surface and an opposed surface, and a substantially planar light guide structure having a light emitting surface that is optically coupled to the opposed surface of the display unit. The light emitting surface of the light guide structure is comprised of an array of gratings arranged as a plurality of sub-arrays of gratings. At least some of the gratings of a given sub-array are configured to emit display light towards the opposed surface of the display unit, and at least one of the gratings of the given sub-array is configured to emit non-display light towards the opposed surface of the display and to receive non-display light that is at least one of reflected from and scattered by at least one object that is proximate to the pixelated display surface. The display unit further comprises a plurality of light sensors that are disposed along at least one edge of the light guide structure and that are configured to detect the received non-display light. The apparatus further comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform at least one of determining a presence and location of the at least one object relative to the pixelated display surface based on output signals of the plurality of light sensors.
In the attached Drawing Figures:
The exemplary embodiments of this invention relate at least in part to diffractive optics that are integrated into a display, such as an LCD, to provide a touch detection functionality.
The use of the exemplary embodiments of this invention removes a need to provide additional, possibly light-obstructing, touch detection-related structures in a display.
The exemplary embodiments of this invention use slanted gratings for in-coupling and tailored grating profiles for out-coupling. The gratings are geometrically arranged in an array of pixels. Gratings may be used to provide backlight illumination in a flat panel display by arranging the in-coupling and out-coupling structures to couple in single red (R), green (G) and blue (B) light sources (generally visible display light), and to couple out the RGB light in a pattern defined by a pattern of pixels of an overlaid LCD display. In accordance with the exemplary embodiments of this invention there is added a matrix of gratings for non-display light (e.g., IR light) to provide the touch detection function.
For the input (both RGB and IR), light is coupled into a backlight structure using any technique suitable for use with LED light sources, such as butt coupling or lens-assisted collimated coupling. The light is fanned out (distributed) to the area of the display using a fan-out grating, or by any suitable technique. For the output, the light is coupled out of the backlight structure by the wavelength-specific structures at the output pixels, arranged in registration with the pixel matrix of the display panel. The wavelength-specific structures may comprise diffraction gratings. One specific grating is used for out-coupling the IR light. The touch detection function is implemented such that as a user touches an area on the top surface of the display structure IR light is reflected or scattered back toward the display structure. Part of the reflected/scattered light is coupled back into a light guide plate of the backlight structure, and directed toward the edges of the light guide plate.
As is shown in
Note that the sensors 26 may be any type of sensor that is suitable for detecting the non-display light used for the touch detection function, e.g., the IR light, such as, but not limited to, photovoltaic or photoconductive sensor devices. The sensors 26 may be arranged along one edge of the light guide plate 10A, or along two perpendicular edges, or arranged at any desired locations enabling the detection of the object 30. Note also that the detection of the presence (and locations) of multiple objects 30 maybe accomplished, such as when a user touches the display surface with two or more fingers. Detection of the movement of the object or objects 30 can also be accomplished by the use of successive detections over a period of time, thereby enabling gesture-based user inputs to be detected, resolved and interpreted by the software 24A.
In
The device 40 may be any type of electronic device that includes a display function, such as a cellular phone or other type of wired or wireless communication apparatus, or a PDA, or a digital camera, or a gaming unit, as several non-limiting examples.
In general, the dimensions of the individual gratings 11 are such that the grating area is about equal to or less than the area of the display pixels or subpixels (e.g., typically in the range of about 50 to about 100 microns in either dimension). The gratings 11 may be fabricated by any suitable process, such as by UV-embossing/replication from a fused silica master.
Note that the LCD subpixel that is specific to the IR grating subpixel may not necessarily have any function regarding displaying visible information, although it may have such functionality. The LCD subpixel that is specific to the IR grating subpixel is configured to be in the transmissive state when the IR light is sent out and potentially scattered/reflected back. The IR subpixel array may be meshed together with the main LCD subpixel array intended for information display.
Note also that in
The IR light may be coupled back into the backlight 10 in two perpendicular directions due to the specificity of the grating for IR light in one direction, and due to the coupling of IR light from the perpendicular gratings. This is the case as the IR light is out of the design wavelength of the grating diffraction rejection (that is, IR will be coupled from the R and B gratings since the wavelength design of these gratings is intended to discriminate between R and B, not between R/IR and B/IR).
One technical effect that is realized by the use of these exemplary embodiments of the invention is that the touch-sensitive display device 20 can be fabricated as an integrated package, in a manner similar to a conventional display, except for having a grating array for the IR light included, and the IR sensors 26 at the edges. This makes the touch-sensitive display device thinner, lighter, and more robust than conventional touch interface displays.
Based on the foregoing it should be apparent that the exemplary embodiments of this invention provide a method, apparatus and computer program(s) to provide a compact touch-sensitive user display apparatus.
The various blocks shown in
In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the exemplary embodiments of this invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
It should thus be appreciated that at least some aspects of the exemplary embodiments of the inventions may be practiced in various components such as integrated circuit chips and modules, and that the exemplary embodiments of this invention may be realized in an apparatus that is embodied as an integrated circuit. The integrated circuit, or circuits, may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or data processors, a digital signal processor or processors, and in a communications device embodiment baseband circuitry and radio frequency circuitry.
Various modifications and adaptations to the foregoing exemplary embodiments of this invention may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this invention.
For example, while the exemplary embodiments have been described above in the context of certain grating parameters and dimensions, wavelengths of display (visible) light and non-display (generally not visible) light, numbers of gratings per sub-array and the like, these various parameters may be changed without departing from the scope of the exemplary embodiments of this invention.
In addition, the exemplary embodiments of this invention are not restricted for use with only LCD-type displays, as other display types (e.g., electrowetting) may be employed.
It should be noted that the terms “connected,” “coupled,” or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are “connected” or “coupled” together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be “connected” or “coupled” together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.
Furthermore, some of the features of the various non-limiting and exemplary embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof.
