Patent Application
20170082267
This disclosure relates generally to display panels, and in particular but not exclusively, relates to seamless tiling of display panels.
Large wall displays can be prohibitively expensive as the cost to manufacture display panels rises exponentially with monolithic display area. This exponential rise in cost arises from the increased complexity of large monolithic displays, the decrease in yields associated with large displays (a greater number of components must be defect free for large displays), and increased shipping, delivery, and setup costs. Tiling smaller display panels to form larger multi-panel displays can help reduce many of the costs associated with large monolithic displays.
Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles being described.
Embodiments of an apparatus and system for a tileable display panel having a frameless screen are described herein. In the following description numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
In the illustrated embodiment, each illumination source 220 is aligned under a corresponding pixel array 230 to illuminate a backside of the corresponding pixel array with lamp light. Illumination sources 220 may be implemented as independent light sources (e.g., color or monochromatic LEDs, quantum dots, etc.) that emit light with a defined angular spread or cone to fully illuminate their corresponding transmissive pixel array 230 residing above on display layer 210. The display sources 220 and transmissive pixel arrays 230 are separated from each other by a fixed distance 245 (e.g., 8 mm). This separation may be achieved using a transparent intermediary (e.g., glass, plastic, air gap, etc.) and may further include one or more lensing layers 221 (including lenses, apertures, beam confiners, etc.) to control or manipulate the angular extent and cross-sectional shape of the lamp light emitted from illumination sources 220. In one embodiment, an illumination controller may be coupled to illumination sources 220 to control their illumination intensity. Illumination layer 205 may include a substrate upon which illumination sources 220 are disposed.
Transmissive pixel arrays 230 are disposed on the display layer 210 and each includes an array of transmissive pixels (e.g., 120 pixels by 120 pixels). In one embodiment, the transmissive pixels may be implemented as backlit liquid crystal pixels. Each transmissive pixel array 230 is an independent display array that is separated from adjacent transmissive pixel arrays 230 by spacing regions 235 on display layer 210. The internal spacing regions 235B that separate adjacent pixel arrays 230 from each other may be twice the width as the perimeter spacing regions 235A that separate a given pixel array 230 from an outer edge of display layer 210. In one embodiment, the internal spacing regions 235B have a width of 10 mm while the perimeter spacing regions 235A have a width of 5 mm. Of course, other dimensions may be implemented.
As illustrated, transmissive pixel arrays 230 are spaced across display layer 210 in a matrix with spacing regions 235 separating each transmissive pixel array 230. In one embodiment, transmissive pixel arrays 230 each represent a separate and independent array of display pixels (e.g., backlit LCD pixels). Spacing region 235 are significantly larger than the inter-pixel separation between pixels of a given transmissive pixel array 230. Spacing regions 235 provide improved flexibility for routing signal lines or the inclusion of additional circuitry, such as a display controller, for controlling operation of transmissive pixel arrays 230. Spacing regions 235A that reside along the exterior perimeter of display layer 210 also provide space for the concealed bezel trim 206 of display 200. Bezel trim 206 operates as the sides of the housing for display 200 but is overlapped by portions of screen layer 215. The spacing regions 235A that reside along the exterior perimeter also provide space for power and/or communication ports. The divergence angle of the display light output from transmissive pixel arrays 230 along with the separation between pixel arrays 230 and the imaging plane of screen layer 215 is selected such that image portions 250 are magnified or expanded to overlap and conceal perimeter bezel trim 206 and spacing regions 235.
Although
Transmissive pixel arrays 230 are switched under control of a display controller to modulate the lamp light and project image portions 250 onto a backside of screen layer 215. In various embodiments, screen layer 215 includes matte material (or other diffusing material suitable for rear projection) that is disposed over a transparent substrate providing mechanical support. As illustrated in
During operation, illumination sources 420 emit divergent lamp light up through lenses 421. Lenses 421 help control the divergence of the lamp light to carefully align with and illuminate the backsides of transmissive pixel arrays 426 on display layer 410. Since tileable display panel 400 is a rear projection display panel that seamlessly stitches image portions together, the separation distance between illumination sources 420 and their corresponding transmissive pixel arrays 426, as well as, the separation distance between transmissive pixel arrays 426 and transparent substrate 450 upon which the diffusing layer 460 is disposed, should be uniformly maintained across the two dimensional surface of tileable display panel 400. Without tightly controlled uniformity in these fixed offset distances, the image portions will not lineup to provide a seamless image either intra-panel or inter-panel.
Accordingly, the illustrated embodiment of tileable display panel 400 includes an array of upper spacer supports 440 and an array of lower spacer supports 422 evenly disposed across the two dimensional area of tileable display panel 400 to evenly support and closely maintain these fixed offset distances. The uniform distribution of upper and lower spacer supports 440 and 422 hold display layer 410 flat without asserting undue stresses on this layer that can cause warping and negatively affect the optical quality of transmissive pixel arrays 426 disposed therein. For example, in the illustrated embodiment, upper spacer supports 440 are disposed on the top side of spacing regions 435 between transmissive pixel arrays 426 while lower spacer supports 422 are aligned directly below upper spacer supports 440 to carry the load supported by upper spacer supports 440 down to electro-mechanical layer 417. This direct load bearing alignment reduces stresses on display layer 410 while providing interior support for display layer 410 and transparent substrate 450 to reduce or eliminate sagging and stresses that would be present if display layer 410 and transparent substrate 450 were only supported around the perimeter by perimeter bezel 419.
In one embodiment, upper spacer supports 440 and lower spacer supports 422 are fabricated of metal (e.g., aluminum) to provide a light weight, rigid, and thermally stable support. In one embodiment, transparent substrate 450 is a glass substrate (e.g., 4 mm thick sheet of glass) to also provide a rigid, transparent, and thermally stable mechanical support to diffusing layer 460 upon which the image is projected. Of course other materials that provide rigid and thermally stable support may also be implemented.
In the illustrated embodiment, upper spacer supports 440 and lower spacer supports 422 have a truncated cone profile shape that is wider towards the bottom or backside of tileable display 400 and narrower towards the top or viewing side of tileable display 400. This truncated cone profile allows optical pathways 424 to expand as the image portions are magnified to cover and overlap the spacing regions 435 and perimeter bezel 419. The thickness of transparent substrate 450 can further be selected in connection with the divergence angle of the display light to achieve the requisite expansion and overlap to conceal the intervening spacing regions 435, interior upper spacer supports 440, perimeter upper spacer supports 440, and perimeter bezel 419. Furthermore, in the illustrated embodiment, transparent substrate 405 along with Fresnel lens 455 and diffusing layer 460 extend all the way to the perimeter edge of tileable display panel 400 and overlap perimeter bezel 419. This provides a frameless screen that is entirely occupied by the aligned image portions.
In the illustrated embodiment, optical pathways 424 are air cavities or air spaces defined by light baffles 423 and 445 having baffled or stepped sides. Light baffles 445 are disposed above display layer 410 while light baffles 423 are disposed below display layer 410. In one embodiment, light baffles 423 and 445 are inserts (e.g., plastic inserts) having a dark or matte black color to reduce stray light reflections. In another embodiment, the light baffles 423 and 445 may be formed into the side surfaces of lower spacer supports 422 and upper spacer supports 440, respectively. For example, lower spacer supports 422 may form an egg carton like array into which black plastic light baffles 423 are inserted. Similarly, in this example, upper spacer supports 440 may form an egg carton like array into which black plastic light baffles 445 are inserted.
In the illustrated embodiment, perimeter bezel 419 does not wrap around the edges or front side of transparent substrate 450. Accordingly, other techniques of bonding transparent substrate 450 to the lower layers of tileable display panel 400 are used. In one embodiment, recesses are formed in the top side of upper spacer supports 440 to provide a dimple for liquid adhesive to bond transparent substrate 450 to upper spacer supports 440. In other embodiments, transfer tape or other adhesive materials may be used. Correspondingly, in some embodiments, the bottom side of upper spacer supports 440 may also include recesses or cavities to provide room for surface mount electronics 430 and optionally to apply adhesives for bonding to display layer 410.
Although not illustrated in
The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.
