Patent Application
20100073328
This relates generally to touch panels used as input devices for computing systems, and more particularly, to improving touch panel detection for touch sensor panels embedded in display modules.
Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, joysticks, touch sensor panels, touch screens and the like. Touch screens, in particular, are becoming increasingly popular because of their ease and versatility of operation as well as their declining price. Touch screens can include a touch sensor panel, which can be a clear panel with a touch-sensitive surface, and a display device such as a liquid crystal display (LCD) that can be positioned partially or fully behind the panel so that the touch-sensitive surface can cover at least a portion of the viewable area of the display device. Touch screens can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus or other object at a location dictated by a user interface (UI) being displayed by the display device. In general, touch screens can recognize a touch event and the position of the touch event on the touch sensor panel, and the computing system can then interpret the touch event in accordance with the display appearing at the time of the touch event, and thereafter can perform one or more actions based on the touch event.
However, the positioning of a display device behind a touch sensor panel in a touch screen can present certain issues. For example, although touch sensor panels are constructed of clear materials, the clarity of a displayed image can be negatively impacted when transmitted through such materials. In addition, the touch sensor panel can contribute increased thickness to the display area of the computing system.
A touch panel display configured to improve touch panel detection for sensor panels embedded in display modules is disclosed. Touch panel detection according to embodiments of the invention can be improved by arranging an optically anisotropic cover over a display module within which an optical sensor panel is embedded.
Since the optically anisotropic cover comprises light-guiding channels through which light is guided by total internal reflection, the cover can effectively shift the sensor plane from an outer surface of the cover, near the location of an object to be detected, to an inner surface of the cover, near the location of the sensor panel. In additional, the optically anisotropic cover can effectively shift the image plane from the inner surface of the cover, near the display module, to the outer surface of the cover, near the viewing surface.
This enables the cover to be provided with varying shapes and sizes with minimal loss of sensor resolution (due to varying cover thicknesses separating an object from a sensor for example) and image quality (due to lensing effects associated with curved surfaces, for example).
In one embodiment, the cover can be formed of a fiber optic bundle. In another embodiment, the cover can be formed of an anisotropic material, such as Ulexite for example. In a further embodiment, the cover can be formed by creating microholes in a substrate having a particular refractive index, and filling the microholes with a material having a higher refractive index.
In the following description of preferred embodiments, reference is made to the accompanying drawings where it is shown by way of illustration specific embodiments in which the invention can be practiced. It is to be understood that other embodiments can be used and structural changes can be made without departing from the scope of the embodiments of this invention.
Embodiments of the invention relate to improving touch panel detection for sensor panels embedded in display modules. Touch panel detection can be improved by arranging an optically anisotropic cover over a display module within which an optical sensor panel is embedded. Since the optically anisotropic cover comprises light-guiding channels through which light is guided by total internal reflection, the cover can effectively shift the sensor plane from an outer surface of the cover, near the location of an object to be detected, to an inner surface of the cover, near the location of the sensor panel. In additional, the optically anisotropic cover can effectively shift the image plane from the inner surface of the cover, near the display module, to the outer surface of the cover, near the viewing surface.
Although some embodiments of this invention may be described and illustrated herein in terms of a display device associated with a portable electronic device, it should be understood that embodiments of this invention are not so limited, but are generally applicable to a touch sensitive display device associated with any structure, such as automated teller machines (ATMs), kiosks/information booths, signature pads, automated check-in terminals at airports, automated check-out machines at retail stores, etc.
Multi-touch touch-sensitive panels according to one embodiment of this invention can detect multiple touches (touch events or contact points) that occur at about the same time (and at different times), and identify and track their locations. Touch sensor panels are disclosed in U.S. application Ser. No. 11/649,998, filed Jan. 3, 2007 and entitled “PROXIMITY AND MULTI-TOUCH SENSOR DETECTION AND DEMODULATION,” the contents of which are incorporated herein by reference in its entirety for all purposes.
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It is noted that the illustrations in
The upward-facing arrows on the right side of display module 200 and anisotropic cover 210 illustrate the shifting of image 207, generated by display module 200, from inner surface 225 of cover 210 to outer surface 215 of cover 210 via light-guiding channels 220. Similarly, the downward-facing arrows on the left side of display module 200 and anisotropic cover 210, under object 205, illustrate the shifting of a sensor plane from outer surface 215 of cover 210 to inner surface 225 of cover 210 via light-guiding channels 220.
It is noted that the illustration in
An optically anisotropic cover in accordance with the teachings of the present invention can coupled to a sensing display module in any suitable manner, such as by lamination or bonding for example. In one embodiment, the cover can constitute a protective layer for the sensing display module and form the external surface of the device or structure into which the sensing display module is incorporated. In another embodiment, a protective layer can be placed over and conform to the optically anisotropic cover.
Touch sensor panel 524 can be embedded within a display module of the display device 530 and include an optical sensing medium having a plurality of drive lines and a plurality of sense lines, although other sensing configurations can also be used. Each intersection of drive and sense lines can represent an optical sensing node and can be viewed as picture element (pixel) 526, which can be particularly useful when touch sensor panel 524 is viewed as capturing an “image” of touch. (In other words, after panel subsystem 506 has determined whether a touch event has been detected at each touch sensor in the touch sensor panel, the pattern of touch sensors in the multi-touch panel at which a touch event occurred can be viewed as an “image” of touch (e.g. a pattern of fingers touching the panel). Each sense line of touch sensor panel 524 can drive sense channel 508 in panel subsystem 506. The display module of display device 530 can be covered with an anisotropic cover to shift the sensor image plane closer to the embedded sensor panel according to embodiments of the invention.
Computing system 500 can also include host processor 528 for receiving outputs from panel processor 502 and performing actions based on the outputs that can include, but are not limited to, moving an object such as a cursor or pointer, scrolling or panning, adjusting control settings, opening a file or document, viewing a menu, making a selection, executing instructions, operating a peripheral device coupled to the host device, answering a telephone call, placing a telephone call, terminating a telephone call, changing the volume or audio settings, storing information related to telephone communications such as addresses, frequently dialed numbers, received calls, missed calls, logging onto a computer or a computer network, permitting authorized individuals access to restricted areas of the computer or computer network, loading a user profile associated with a user's preferred arrangement of the computer desktop, permitting access to web content, launching a particular program, encrypting or decoding a message, and/or the like. Host processor 528 can also perform additional functions that may not be related to panel processing, and can be coupled to program storage 532 and display device 530 for providing a UI to a user of the device. Touch sensing display device 530 together with an anisotropic cover layer can form a touch screen.
Note that one or more of the functions described above can be performed by firmware stored in memory (e.g. one of the peripherals 504 in
The firmware can also be propagated within any transport medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “transport medium” can be any medium that can communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The transport readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic or infrared wired or wireless propagation medium.
The mobile telephone, media player and personal computer of
Although embodiments of this invention have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of embodiments of this invention as defined by the appended claims.
