Patent Description:
A concern in the design of tiled LED display systems having LED modules, sometimes termed LED module boards, is the appearance of "dark line" defects in the seam between adjacent LED modules, especially between LED modules across adjacent LED tiles. Dark line defects refer to the visible dark lines that are sometimes visible to a viewer where the spacing between adjacent LED modules is too great for the adjacent LED modules to create the impression of a continuous image from one LED module to the next. The maximum module spacing error beyond which such dark line defects are perceived is typically approximately of <NUM>% of the nominal pixel pitch of the LED modules. For example, a <NUM> nominal pixel pitch gives rise to a spacing error of <NUM> x <NUM> = <NUM> (<NUM>) such that a pixel pitch of <NUM> or less across module boundaries is required to avoid the perception of dark line defects by a viewer.

LED modules arranged in a tiled LED display system are therefore often spaced closely together, with minimal allowable spacing error, to avoid the appearance of dark line defects. This requirement to tightly space LED modules together results in challenging design, manufacturing, and installation requirements. Even where such requirements are followed, the occurrence of dark line defects can persist. Document <CIT>, according to its abstract, discloses a seamless video display spliced wall, which is formed by splicing a plurality of displays. A plurality of light-emitting diodes, LED, are arranged in splicing gaps between the displays, and the brightness and colors of the LEDs can be matched according to the image display conditions of adjacent displays. The LEDs are connected with a master control computer through control lines, and the master control computer transmits corresponding data to each LED according to an actual image displayed by the video display spliced wall, and independently regulates the LEDs to make the brightness and colors of the LEDs matched with images displayed by the adjacent displays to fulfill the aim of eliminating and reducing the splicing gaps between the displays. Or, each LED can be connected with an independent optical detector, the optical detectors detect the image information of the adjacent displays and transmit the image information to the LEDs connected with the optical detectors, and the brightness and colors of the LEDs are matched with the images displayed by the adjacent displays. By the seamless video display spliced wall, the remarkable splicing gaps of the conventional video display spliced wall are greatly faded, and the overall effect of seamless splicing is achieved.

Document <CIT>, according to its abstract, states a seamless video display spliced wall, which is formed by splicing a plurality of displays. A plurality of light-emitting diodes (LED) are arranged in splicing gaps between the displays, and the brightness and colors of the LEDs can be matched according to the image display conditions of adjacent displays. The LEDs are connected with a master control computer through control lines, and the master control computer transmits corresponding data to each LED according to an actual image displayed by the video display spliced wall, and independently regulates the LEDs to make the brightness and colors of the LEDs matched with images displayed by the adjacent displays to fulfill the aim of eliminating and reducing the splicing gaps between the displays. Or, each LED can be connected with an independent optical detector, the optical detectors detect the image information of the adjacent displays and transmit the image information to the LEDs connected with the optical detectors, and the brightness and colors of the LEDs are matched with the images displayed by the adjacent displays.

Document <CIT>, according to its abstract, states an area-emissive light-emitting diode (LED) device comprises a substrate having an internal substrate surface, an external substrate surface opposite the internal substrate surface, and a substrate edge; an array of area-emissive LED pixels formed on the internal substrate surface with an edge gap between the substrate edge and the LED pixel on the internal substrate surface nearest the substrate edge; and a light-extraction structure formed in the edge gap and at least partially exterior to the LED pixels.

The present disclosure relates to the reduction of dark line defects arising from seams between adjacent LED modules in a tiled direct view LED display system. The present disclosure sets forth an LED display system comprising a set of illuminating pixels for illuminating the seams between the adjacent LED modules, thereby reducing dark line defects.

There is provided an LED module for use in an LED display system, the LED module comprising: a set of imaging pixels disposed on an imaging side of the LED module, and configured to generate imaging illumination; a set of illuminating pixels disposed on a rearward side of the LED module and adjacent to an edge of the rearward side, the rearward side opposite to the imaging side, and configured to generate illumination around the edge; and a reflector extending from the second side to direct the illumination around the edge through a seam between the LED module and an adjacent LED module.

Further, there is provided an LED system comprising an LED module according to the above.

Other features and advantages of the LED display system are described more fully below.

Non-limiting embodiments will now be described, by way of example only, with reference to the attached Figures, wherein:.

The present disclosure relates to the reduction of dark line defects arising from seams between adjacent LED modules, sometimes termed LED module boards, in an LED display system. Where a seam, or gap, between adjacent LED modules in an LED display system is too large for the LED display system to create the impression of a continuous image from one LED module to the next, a dark line defect can result. The occurrence of dark line defects is especially apparent between adjacent LED modules of adjacent LED tiles in a tiled LED display system.

According to the present disclosure, an LED display system has a coupling assembly for securing adjacent LED modules, including a first LED module, and at least one second LED module adjacent to the first LED module. The coupling assembly secures the first and second LED modules in adjacent arrangement within LED tiles and between LED tiles.

The LED modules have sets of imaging pixels, situated on the imaging sides thereof, for generating an image viewable from an imaging direction. At least the first LED module also has a set of illuminating pixels, situated on the rearward side opposite the imaging side, for illuminating the seams between adjacent LED modules. In some embodiments, the illuminating pixels illuminate the seam between adjacent LED modules across adjacent LED tiles. In some embodiments, the illuminating pixels provide illumination which is reflected off a reflector and directed toward the seam, thereby illuminating the seam and reducing dark line defects. Reducing dark line defects may generally improve the appearance of the image generated by the LED display system, and allow for greater flexibility in seam tolerances in LED display system manufacture and assembly.

In some embodiments, the LED display system may have a control unit for controlling the imaging pixels, and for controlling the illuminating pixels in response to the image being generated such that the seam illumination blends in colour or intensity with the image being generated by the imaging pixels.

In some embodiments, the imaging pixels and the illuminating pixels may use the same or similar LED chips, and the illuminating pixels may be aligned in pitch with the imaging pixels.

In some embodiments, physical components of the LED display system or the LED modules may be designed to improve optical coupling from the illuminating pixels toward the seam. For example, the rearward side of the LED modules may be beveled toward the seam to improve optical coupling. As another example, the reflector may incorporate a series of concave portions aligned with each illuminating pixel for more precisely directing illumination toward the seam. As another example, portions of the LED display system or LED module may be treated with optical coatings, such as diffuse coatings or reflective coatings, to achieve desirable optical properties.

Non-limiting embodiments of an LED display system having LED modules which may exhibit a dark line defect is presented in the following <FIG>. For convenience, reference numerals may be repeated (with or without an offset) to indicate analogous components or features.

<FIG> is a schematic diagram of an LED display system <NUM>, according to a non-limiting embodiment. The LED display system <NUM> comprises a media source <NUM> which provides an input, such as an image feed or a video feed to be displayed by the LED display system <NUM>. The media source <NUM> may comprise a computing device, a DVD, CD-ROM, or other media player, a camera, camcorder, or any other media device capable of providing an image or video feed to the LED display system <NUM>.

The LED display system <NUM> further comprises a video matrix switch and splicing video processor <NUM>, hereinafter referred to as a switch & processor <NUM>. The switch & processor <NUM> receives an image feed or video feed from at least one media source <NUM>. In embodiments in which multiple media source <NUM> are connected to the LED display system <NUM>, the switch & processor <NUM> is configurable to select a single media source <NUM>, or to blend & process multiple media sources <NUM>, for display by the LED display system <NUM>.

The LED display system <NUM> further comprises a control unit <NUM>, a control computer <NUM>, and an LED display <NUM>. The control unit <NUM> receives the image or video feed from switch & processor <NUM>, and contains software, hardware, or firmware instructions for controlling the LED display <NUM> to display the image feed or video feed (hereinafter referred to simply as the image). The control computer <NUM> comprises a computing device in communication with control unit <NUM> configured to provide additional computation or control capacity to the control unit <NUM> for altering display to the LED display <NUM>.

The LED display <NUM> comprises several LED tiles <NUM> in adjacent arrangement. With reference to <FIG>, and with continued reference to <FIG>, it can be seen that each LED tile <NUM> contains several LED modules <NUM> in adjacent arrangement. The LED modules <NUM> comprise several pixels, controlled by control unit <NUM>, for generating the image to be displayed by the LED display <NUM>. The LED display system <NUM> further comprises a power supply <NUM> for powering the LED tiles <NUM>.

<FIG> is an assembly drawing of an LED tile <NUM>, according to a non-limiting embodiment. The LED tile <NUM> comprises a carrier assembly <NUM> for coupling with several LED modules <NUM> in adjacent arrangement. The carrier assembly <NUM> is secured into a chassis <NUM>. The tile chassis <NUM> has attachment points for mounting blocks <NUM>, which may be used to mount and arrange several LED tiles <NUM> adjacently into the LED display <NUM>. The carrier assembly <NUM> has side edges <NUM> against which LED modules <NUM> may be adjacently situated.

The carrier assembly <NUM>, chassis <NUM>, and mounting blocks <NUM> may be referred to collectively as coupling assembly <NUM>. However, the term coupling assembly <NUM> is not thereby limited, and may be used to refer to several carrier assemblies <NUM>, chassis <NUM>, and mounting blocks <NUM>, employed to arrange several LED tiles <NUM> in adjacent arrangement. Furthermore, the term coupling assembly <NUM> may refer to an individual carrier assembly <NUM>, where adjacent LED modules <NUM> are of concern. In sum, the term coupling assembly <NUM> may be used generally to refer to any structure in an LED display system for arranging LED modules <NUM> in adjacent arrangement within an LED tile <NUM> or across adjacent LED tiles <NUM>.

<FIG> is an enlarged schematic drawing of two adjacent LED modules <NUM>, indicated as LED modules <NUM>-<NUM> and <NUM>-<NUM>. Each LED module <NUM>-<NUM>, <NUM>-<NUM> is shown from its imaging (front) side <NUM>-<NUM>, <NUM>-<NUM>, which features sets of imaging pixels <NUM>-<NUM>, <NUM>-<NUM>, disposed thereon. Each LED module <NUM>-<NUM>, <NUM>-<NUM> has a rearward side <NUM>-<NUM>, <NUM>-<NUM> (see <FIG> and <FIG>), opposite the imaging sides <NUM>-<NUM>, <NUM>-<NUM>. On the imaging side <NUM>-<NUM>, <NUM>-<NUM>, the imaging pixels <NUM>-<NUM>, <NUM>-<NUM> are spaced apart according to a common pitch distance <NUM>.

In the present embodiment, an imaging pixel <NUM>-<NUM>, <NUM>-<NUM> comprises a group of one red, one green, and one blue LED. Each red, green, and blue LED may be referred to as a subpixel. In the present embodiment, each subpixel comprises an LED chip, and each LED module <NUM>-<NUM>, <NUM>-<NUM> comprises a printed circuit board (PCB) having an array of LED chips on imaging sides <NUM>-<NUM>, <NUM>-<NUM>.

The two LED modules <NUM>-<NUM>, <NUM>-<NUM>, are arranged adjacently on the carrier assembles <NUM>-<NUM>, <NUM>-<NUM> (not shown), and are separated by a space, gap, or seam, indicated as seam <NUM>. In the present embodiment, LED module <NUM>-<NUM> is situated on an LED tile <NUM>-<NUM>, and LED module <NUM>-<NUM> is situated on an adjacent LED tile <NUM>-<NUM>. Thus, the seam <NUM> is between adjacent LED tiles <NUM>-<NUM>, <NUM>-<NUM>. However, in other embodiments, LED modules <NUM>-<NUM> and <NUM>-<NUM> may be situated on an individual LED tile <NUM>, with the seam <NUM> being between LED modules <NUM>-<NUM>, <NUM>-<NUM>, within LED tile <NUM>.

The seam <NUM> defines a plane <NUM> spanning the space between LED modules <NUM>-<NUM>, <NUM>-<NUM> (best shown in <FIG>). The seam <NUM> causes an effective pitch distance across LED modules <NUM>-<NUM>, <NUM>-<NUM>, indicated as seam pitch distance <NUM>. Typically, the installation of LED tiles <NUM>-<NUM> and <NUM>-<NUM> is confined such that the size of the seam <NUM> is minimal, and such that seam pitch distance <NUM> is about equal to pitch distance <NUM>. Thus, the impression of a continuous image from LED module <NUM>-<NUM> on LED tile <NUM>-<NUM> to LED module <NUM>-<NUM> on LED tile <NUM>-<NUM> is created with no dark line defects. As discussed above, the maximum module spacing error beyond which such dark line defects are perceived is typically approximately <NUM>% of the nominal pixel pitch, i.e. pitch distance <NUM>, of the LED modules <NUM>-<NUM>, <NUM>-<NUM>. Strict practices in design, manufacturing, and installation, are often imposed to achieve such tight tolerances. However, even where such practices are employed, seam pitch distance <NUM> may vary significantly from pitch distance <NUM>, and the occurrence of dark line defects may persist, as shown in <FIG> and discussed below.

<FIG> is an intensity plot <NUM> indicating pixel intensity of two adjacent LED modules <NUM>-<NUM>, <NUM>-<NUM>, according to a non-limiting embodiment. As an example, plot <NUM> shows the intensity of each imaging pixel <NUM>-<NUM>, <NUM>-<NUM>, of LED modules <NUM>-<NUM>, <NUM>-<NUM>, situated on LED tiles <NUM>-<NUM>, <NUM>-<NUM>, respectively, indicated as grayscale peaks <NUM>-<NUM> and <NUM>-<NUM>, respectively. It can be seen that peaks <NUM>-<NUM> and <NUM>-<NUM> have a common pitch distance <NUM>, which in the present example is about <NUM>. On the lefthand side of the plot, it can be seen that the imaging pixels <NUM>-<NUM> on LED module <NUM>-<NUM>, on LED tile <NUM>-<NUM>, peak at about <NUM> grayscale, whereas on the right-hand side of the plot, it can be seen that the imaging pixels <NUM>-<NUM> on LED module <NUM>-<NUM>, on LED tile <NUM>-<NUM>, peak at about <NUM> grayscale. Furthermore, the average intensity <NUM>-<NUM> is at about <NUM> grayscale, and the average intensity <NUM>-<NUM> is at about <NUM> grayscale. The difference in intensity may represent different images or sections of an image displayed by each respective LED tile <NUM>-<NUM>, <NUM>-<NUM>.

The peaks <NUM>-<NUM> of LED module <NUM>-<NUM> are separated from the peaks <NUM>-<NUM> of LED module <NUM>-<NUM> by seam pitch distance <NUM>, which in the present example is about <NUM>. Seam pitch distance <NUM> is exaggerated to represent a large gap, or seam <NUM>, between LED tiles <NUM>-<NUM>, <NUM>-<NUM>, that may produce a dark line defect. The average intensity across seam <NUM>, indicated as seam intensity <NUM>, is about <NUM> grayscale, representing a noticeable dark line defect given the large seam pitch distance <NUM>.

Increasing seam intensity <NUM> by filling the seam <NUM> with additional illumination may reduce dark line defects. Thus, plot <NUM> further indicates non-limiting examples of intensity levels to which it may be desirable to increase seam intensity <NUM> in order to reduce the visibility of a dark line defect. For example, in some embodiments, it may be desirable for seam intensity <NUM> to reach about one quarter, about one half, or about three quarters, of the average intensity of the LED modules <NUM>-<NUM>, <NUM>-<NUM>, or the combination thereof, indicated as intensity values 330A, 330B, and 330C, respectively. In such embodiments, either LED module <NUM>-<NUM> or <NUM>-<NUM>, or the combination thereof, may be used as a reference point for average intensity (average intensities <NUM>-<NUM> or <NUM>-<NUM>).

In other embodiments, it may be desirable for seam intensity <NUM> to match the average intensity of an LED module <NUM>-<NUM>, <NUM>-<NUM>. In such embodiments, as above, either LED module <NUM>-<NUM> or <NUM>-<NUM>, or the combination thereof, may be used as a reference point for average intensity (average intensities <NUM>-<NUM> or <NUM>-<NUM>). A seam intensity <NUM> matching the combination of LED modules <NUM>-<NUM>, <NUM>-<NUM>, is indicated as intensity value 330D.

Controlling seam intensity <NUM> in response to pixel intensities of nearby LED modules <NUM>-<NUM>, <NUM>-<NUM> as discussed above may be referred to as an illumination scheme. In the illumination schemes described above, the desirable intensity values presented here are exemplary only, as any increase in the intensity of illumination across seam <NUM> may reduce dark line defects.

Non-limiting embodiments of LED modules <NUM>, which may reduce the occurrence or severity of dark line defects, are presented in <FIG> below. For convenience, reference numerals, including those originating from <FIG>, may be repeated to indicate analogous components or features.

<FIG> is a schematic diagram of an LED module <NUM>, according to a non-limiting embodiment. LED module <NUM> comprises an imaging (front) side <NUM>, having set of imaging pixels <NUM> thereon. By way of example only, the LED module <NUM> is shown as having a resolution of <NUM> x <NUM> pixels and configured in a regular array, but any resolution or configuration of imaging pixels <NUM> is contemplated.

<FIG> is a schematic diagram of LED module <NUM>, viewed from a rearward direction. LED module <NUM> includes rearward side <NUM>, opposite the imaging side <NUM>, having a set of illuminating pixels <NUM> disposed thereon.

The rearward side <NUM> comprises edges <NUM>. The rearward side <NUM> has a perimeter, and in the present embodiment, illuminating pixels <NUM> are situated around the perimeter <NUM>. The perimeter <NUM> need not be situated precisely at the edges <NUM> of rearward side <NUM>, but may be offset inward of the edges <NUM>, as shown, to provide sufficient clearance for illuminating pixels <NUM> from the edges <NUM>.

In the present embodiment, the illuminating pixels <NUM> are situated around perimeter <NUM> in a single layer such that each illuminating pixel <NUM> is close in proximity to a seam <NUM> between the LED module <NUM> and an adjacent LED module. Such embodiments may be desirable to facilitate inclusion of a reflector extending from the rearward side <NUM> of the LED modules <NUM>, as discussed below. Such embodiments may also be desirably where only a single layer of pixels is necessary to illuminate a seam <NUM>. In other embodiments, however, multiple layers of illuminating pixels <NUM> may be employed to provide additional seam illumination.

In the present embodiment, the edges <NUM> are beveled, indicated as bevel <NUM>, around perimeter <NUM>, for improving optical coupling around the edges <NUM>, a feature discussed in greater detail below.

In the present embodiment, the rearward side <NUM> further provides interior space <NUM> as space for coupling with a carrier assembly <NUM>, providing electrical connections to control unit <NUM>, or for providing attachment with a reflector, as discussed below.

In the present embodiment, each illuminating pixels <NUM> comprises a group of one red, one green, and one blue LED. In the present embodiment, each subpixel comprises an LED chip that is the same or similar to the LED chips used in imaging pixels <NUM>. However, in other embodiments, imaging pixels <NUM> and illuminating pixels <NUM> may comprise dissimilar LED chips. For example, in some embodiments it may be desirable for illuminating pixels <NUM> may vary in form factor, power supply voltage, color depth, LED type, or other characteristics from imaging pixels <NUM>.

<FIG> is a partial perspective view of the LED module <NUM>, according to a non-limiting embodiment. LED module <NUM> includes set of imaging pixels <NUM> on imaging side <NUM> and set of illuminating pixels <NUM> on rearward side <NUM>. LED module <NUM> includes module body <NUM> between sides <NUM>, <NUM>. Module body <NUM> comprises a printed circuit board having electrical connections for imaging pixels <NUM>, illumination pixels <NUM>, and communication with control unit <NUM>.

Direction <NUM> indicates the general direction in which illuminating pixels <NUM> generate imaging illumination. Plane <NUM> indicates a plane which would be defined by a seam <NUM> between the LED module <NUM> and an adjacent LED module. In the present embodiment, LED module <NUM> is situated on an LED tile <NUM>, and the seam <NUM> is between LED tiles <NUM>, and an adjacent LED tile <NUM> (not shown).

<FIG> further shows a reflector <NUM>, integral with a coupled carrier assembly <NUM> of LED tile <NUM>, and extending rearwardly from rearward side <NUM>, and curving toward the plane <NUM>, as described in greater detail in <FIG> below.

In the present embodiment, the rearward side <NUM> is shown having an edge <NUM>, beveled at about <NUM> degrees to form bevel <NUM>, to improve optical coupling of illumination directed toward the seam <NUM>. However, it is contemplated that in other embodiments, edge <NUM> may not be beveled, or that the bevel <NUM> may be made at other angles, or curved, in order to improve optical coupling toward the seam <NUM>.

<FIG> is a partial sectional view of two adjacent LED modules <NUM>-<NUM>, and <NUM>-<NUM>, according to a non-limiting embodiment. The LED modules <NUM>-<NUM>, <NUM>-<NUM> are situated on LED tiles <NUM>-<NUM>, <NUM>-<NUM>, respectively, and have a seam <NUM> therebetween, which defines a plane <NUM>, and which results in a seam pitch distance of <NUM>. Imaging pixels <NUM>-<NUM>, <NUM>-<NUM> are situated on imaging sides <NUM>-<NUM>, <NUM>-<NUM> to generate imaging illumination in the imaging (forward) direction <NUM>. The LED modules <NUM>-<NUM>, <NUM>-<NUM>, have illuminating pixels <NUM>-<NUM>, <NUM>-<NUM> on the rear sides <NUM>-<NUM>, <NUM>-<NUM> thereof for generating seam illumination <NUM>-<NUM>, <NUM>-<NUM>.

The carrier assemblies <NUM>-<NUM>, <NUM>-<NUM> include integral reflectors <NUM>-<NUM>, <NUM>-<NUM>, extending from rearward sides <NUM>-<NUM>, <NUM>-<NUM> of LED modules <NUM>-<NUM>, <NUM>-<NUM>, and curving toward the plane <NUM>. In the present embodiment, each reflector <NUM>-<NUM>, <NUM>-<NUM> is integral with its corresponding carrier assembly <NUM>-<NUM>, <NUM>-<NUM>, and each reflector <NUM>-<NUM>, <NUM>-<NUM> comprises an elongated portion <NUM>-<NUM>, <NUM>-<NUM> and a curved portion <NUM>-<NUM>, <NUM>-<NUM>. The elongated portions <NUM>-<NUM>, <NUM>-<NUM> generally extend in the rearward direction, opposite the imaging direction <NUM>, from the rearward sides <NUM>-<NUM>, <NUM>-<NUM>. The elongated portions <NUM>-<NUM>, <NUM>-<NUM> terminate at curved portions <NUM>-<NUM>, <NUM>-<NUM>, which extends generally toward the plane <NUM>. Curved portions <NUM>-<NUM>, <NUM>-<NUM> are curved to reflect and direct seam illumination <NUM>-<NUM>, <NUM>-<NUM> generally toward and through seam <NUM>.

In the present embodiment, it can be seen that the curved portions <NUM>-<NUM>, <NUM>-<NUM> terminate before reaching the plane <NUM>, leaving an opening <NUM> that is at least as wide as seam <NUM>. The opening <NUM> is sufficiently wide so as to not interfere with the adjacent arrangement of LED tiles <NUM>-<NUM>, <NUM>-<NUM>.

In operation, rearward illumination from illuminating pixels <NUM>, indicated generally as seam illumination <NUM>-<NUM>, <NUM>-<NUM>, is generated by illumination pixels <NUM>-<NUM>, <NUM>-<NUM>, and reflected off the reflectors <NUM>-<NUM>, <NUM>-<NUM>, and particularly curved portions <NUM>-<NUM>, <NUM>-<NUM>, toward seam <NUM>. The seam illumination <NUM>-<NUM>, <NUM>-<NUM> is directed through seam <NUM> and generally in the imaging direction <NUM>. Thus, where the seam pitch distance <NUM> is sufficiently great to develop a dark line defect between LED modules <NUM>-<NUM>, <NUM>-<NUM>, the severity of the dark line defect may be reduced.

Module bodies <NUM>-<NUM>, <NUM>-<NUM> each comprises a printed circuit board having electrical connections for imaging pixels <NUM>-<NUM>, <NUM>-<NUM>, illumination pixels <NUM>-<NUM>, <NUM>-<NUM>, and communication with control unit <NUM>. In some embodiments, the illumination pixels <NUM>-<NUM>, <NUM>-<NUM> are controlled according to an illumination scheme. As discussed above, illumination pixels <NUM>-<NUM>, <NUM>-<NUM> may be configured to develop a seam intensity <NUM> approaching about one quarter, one half, or about three quarters, of the average intensity of any combination of the LED modules <NUM>-<NUM>, <NUM>-<NUM> on which the illumination pixels <NUM>-<NUM>, <NUM>-<NUM> are disposed or adjacent LED modules <NUM>-<NUM>, <NUM>-<NUM>. In some embodiments, seam intensity <NUM> may approach or approximately equal the average pixel intensity of the LED modules <NUM>-<NUM>, <NUM>-<NUM> on which the illumination pixels <NUM>-<NUM>, <NUM>-<NUM> are disposed or an adjacent LED module <NUM>-<NUM>, <NUM>-<NUM>. Further, in some embodiments, the colour of illumination pixels <NUM>-<NUM>, <NUM>-<NUM> may match that of imaging pixels <NUM>-<NUM>, <NUM>-<NUM>.

The illumination schemes discussed above may be referred to as involving control of an illuminating property (a colour or intensity of an illumination pixel <NUM>-<NUM>, <NUM>-<NUM>) in response to an imaging property (a colour or intensity of an imaging pixel <NUM>-<NUM>, <NUM>-<NUM>). In general, the term imaging property can be used to refer to an intensity or colour of at least one pixel in the set of imaging pixels <NUM>-<NUM>, <NUM>-<NUM>. In other words, an imaging property may refer to the colour or intensity of any pixel contributing to an image being generated. Similarly, the term illuminating property can be used to refer to an intensity or colour of at least one pixel in the set of illuminating pixels <NUM>-<NUM>, <NUM>-<NUM>. In other words, an illuminating property may refer to the colour or intensity of any pixel contributing to seam illumination <NUM>-<NUM>, <NUM>-<NUM>. Thus, according to an illumination scheme, an illuminating property may be controlled in response to, to conform with, or to track, an imaging property, so that the seam <NUM> is filled with light from illuminating pixels <NUM> that blends or matches the image being generated by imaging pixels <NUM>-<NUM>, <NUM>-<NUM>.

In some embodiments in which the image generated by imaging pixels <NUM>-<NUM>, <NUM>-<NUM> is dynamic, such as where the image generated is part of a video, the illuminating pixels <NUM>-<NUM>, <NUM>-<NUM> may be controlled dynamically by control unit <NUM> in response to changing imaging properties.

Referring again to <FIG>, and <FIG>, it can be seen that in some embodiments, the illuminating pixels <NUM> may be aligned in pitch with imaging pixels <NUM>. In such embodiments, each illuminating pixel <NUM> may correspond with an imaging pixel <NUM>. In such embodiments, the illumination scheme may comprise controlling an illuminating property of each illuminating pixel <NUM> in response to an imaging property of its corresponding imaging pixel <NUM>. Thus, seam illumination <NUM> may be controlled to accurately blend with imaging illumination from the illuminating pixels <NUM> and may track the colours and intensities on a pixel-by-pixel basis of the image generated by the imaging pixels <NUM>. In other embodiments, illuminating pixels <NUM> may not be aligned in pitch with imaging pixels <NUM>, provided the illuminating pixels <NUM> provide seam illumination <NUM> through seam <NUM>.

In some embodiments, portions of the reflectors <NUM>, module body <NUM>, bevel <NUM>, or other structures may be treated with optical coatings, such as diffuse coatings or reflective coatings, to achieve desirable optical properties.

<FIG> further depict non-limiting embodiments of LED modules 200A, 200B, 200C, and 200D, in which several configurations of LED modules <NUM> and reflectors <NUM> are contemplated.

In <FIG>, the LED module 200A has a reflector 260A comprising a continuously curved portion 262A extending from the from the rearward side 202A, integral with a carrier assembly 132A. Thus, it can be seen that the shape of the reflector 260A may vary, provided that its shape directs seam illumination 270A through seam 220A. Furthermore, edge 207A is not beveled, but rather straight-edged toward seam 220A. Thus, it can be seen that beveling an edge <NUM> may be desirable but is optional.

In <FIG>, the LED module 200B has a reflector 260B comprising an extending portion 262B, and further comprising a straight-angled portion 264B in place of a curved portion <NUM>, integral with a carrier assembly 132B. In other embodiments, LED module 200B may comprise several straight-angled portions 262B positioned at varying angles. Thus, it can be seen that the shape of a reflector <NUM> may vary provided it reflects seam illumination 270B toward a seam 220B.

In <FIG>, the LED module 200C comprises a reflector 260C that is integral with the LED module 200C rather than integral with carrier assembly 132C. Thus, it can be seen that the location of a reflector <NUM> may vary provided it reflects seam illumination 270C toward a seam 220C.

In other embodiments not shown, a reflector <NUM> may be reversibly attachable to the LED module <NUM>, or the carrier assembly <NUM>, chassis <NUM>, or other structure of the LED display <NUM>.

In <FIG>, the LED module 200D comprises an extending portion 262D on which illuminating pixels 250D are disposed. The illuminating pixels 250D are angled to direct seam illumination 270D generally toward the seam 220D without reflection off a reflector.

<FIG> is a partial perspective view of an LED module 200E according to another non-limiting embodiment. LED module 200E has a reflector 260E comprising a series of curved portions 264E. In some embodiments, as shown, the curved portions 264E may align in pitch with an illuminating pixels 250E situated above the curved portion 264E in the imaging direction 201E. Thus, seam illumination 270E is more precisely directed toward a seam 220E. Furthermore, in some embodiments in which each illuminating pixel 250E corresponds with an imaging pixel 210E, seam illumination 270E from an illuminating pixel 250E is more precisely directed toward a seam 220E near its corresponding imaging pixel 210E, and when controlled in intensity and colour by a control unit <NUM>, thereby more precisely tracks the image being generated by imaging pixels 210E.

Although in the present figures, only a single seam <NUM> is shown between two adjacent LED modules <NUM>, it will be understood that in an arrangement of several LED modules <NUM> there may be several seams <NUM>. For example, as shown in <FIG>, LED modules <NUM> on LED tile <NUM> will have seams <NUM> between two, three, or four adjacent LED modules <NUM>, with each seam <NUM> being illuminated. Furthermore, it will be understood that other embodiments may exist in which LED modules <NUM> take on other shapes, provided the shapes may be arrange adjacently with a seam <NUM> therebetween.

Furthermore, in embodiments in which the seam <NUM> of concern is between adjacent LED tiles <NUM>, seam illumination <NUM> is to be directed around side edges <NUM> (see <FIG>) of LED tiles <NUM>, as shown in <FIG>. In such embodiments, LED modules 200F without illuminating pixels <NUM> may be used in the interior of the LED tile <NUM>, whereas LED modules <NUM> having illuminating pixels <NUM> may be situated around the perimeter of the LED tiles <NUM>. Such arrangements may save energy where the seam <NUM> of concern is around LED tile <NUM> rather than between adjacent LED modules <NUM> within LED tile <NUM>.

Further still, in embodiments in which the seam <NUM> of concern is between adjacent LED tiles <NUM>, and in which seam illumination <NUM> is to be directed around side edges <NUM> of LED tiles <NUM>, modified LED modules <NUM> having illuminating pixels <NUM> along the edges <NUM> which abut against side edges <NUM> of LED tiles <NUM> may be employed, as shown in <FIG>. In such embodiments, corner LED modules <NUM>, long-side LED modules <NUM>, and short-side LED modules 200J, each having illuminating pixels <NUM> only around the edges <NUM> which abut side edges <NUM> of LED tiles <NUM>, may be employed. Such arrangements may save energy where the seam <NUM> of concern is around LED tile <NUM> rather than between adjacent LED modules <NUM> within LED tile <NUM>. Similar to <FIG>, LED modules 200F without illuminating pixels <NUM> may be used in the interior of the LED tile <NUM>.

Thus, it can be seen that an LED display system can be provided having LED modules providing seam illumination to reduce dark line defects. Seam illumination can be generated by illuminating pixels on the rearward side of LED modules, directed through the seam by a reflector, and may be controlled in colour or intensity to blend with the image being produced by the LED module. Thus, greater flexibility in seam tolerances in design, manufacturing, and installation requirements is enabled, and the incidence or severity of dark line defects may be reduced, improving the appearance of the image generated by the LED display system.

Claim 1:
An LED module (<NUM>) for use in an LED display system (<NUM>), the LED module (<NUM>) comprising:
a set of imaging pixels (<NUM>) disposed on an imaging side (<NUM>) of the LED module (<NUM>), and configured to generate imaging illumination;
a set of illuminating pixels (<NUM>) disposed on a rearward side (<NUM>) of the LED module and adjacent to an edge (<NUM>) of the rearward side (<NUM>), the rearward side (<NUM>) opposite to the imaging side (<NUM>), and configured to generate illumination around the edge (<NUM>); and
a reflector (<NUM>) extending from the rearward side (<NUM>) to direct the illumination around the edge (<NUM>) through a seam (<NUM>) between the LED module (<NUM>) and an adjacent LED module (<NUM>).