Image generating block for use in digital signage

Abstract

Disclosed is image generating block (100, 200) for use in digital signage. Image generating block comprises array of liquid crystal display (LCD) cells (102) covered by glass (104) on first side (102A); backlight module (106, 306) having array of LED PCBs (310) illuminating second side (102B) of array of LCD cells; and optical layer (108) arranged between second side of array of LCD cells and backlight module, configured to adjust incident angle and wavelength of illumination. Optical layer comprises reflector foil (110) configured to provide passage for illumination to pass through optical layer towards array of LCD cells; diffuser layer (112) configured to disperse illumination within optical layer; polarization layer (118, 218) configured to manipulate illumination into predefined orientation; and amplification foil (120) configured to reflect first part of illumination back to reflector foil, and guide second part of illumination towards second side of array of LCD cells.

Description

[0001] IMAGE GENERATING BLOCK FOR USE IN DIGITAL SIGNAGE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to image generating blocks for use in digital signages.

[0004] BACKGROUND

[0005] Electronic displays are widely being opted for various purposes such as showcasing information, advertisements, broadcasting live or recorded media (such as sport events, public events, motion pictures), and so on. Thus, there is a growing need for increased brightness and size in electronic displays, especially in outdoor environment, in order to compensate for ambient light in the outdoor environment. However, increased size and brightness in electronic displays are associated with an exponential increase in power consumption. Moreover, with the increase in power consumption in high-brightness electronic displays of larger size, overall heat within the electronic displays also increases, thus making cooling thereof difficult. Inefficient cooling further leads to degraded operational efficiency and a shorter lifetime of such electronic displays. Additionally, this results in a shorter lifetime of the electronic displays and of separate components inside the electronic displays.

[0006] Conventional electronic displays utilise image generating components and backlighting components with light emitting diodes (LEDs) to display contents thereon. However, conventional electronic displays lack optimal colour rendering ability, which leads to uneven light distribution and optical anomalies like light spots visible light spots on the electronic displays. Therefore, conventional electronic displays experience inconsistent and degraded performance. Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks.

[0007] SUMMARY

[0008] The aim of the present disclosure is to provide an image generating block for use in a digital signage which effectively reproduces the colour profile of an input while adjusting brightness optimally to improve the quality of visuals thereon. The aim of the present disclosure is achieved by an image generating block for use in a digital signage as defined in the appended independent claims to which reference is made to. Advantageous features are set out in the appended dependent claims.

[0009] Throughout the description and claims of this specification, the words "comprise" , "include", "have", and "contain" and variations of these words, for example "comprising" and "comprises" , mean "including but not limited to", and do not exclude other components, items, integers or steps not explicitly disclosed also to be present. Moreover, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0010] BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is an illustration of an image generating block, in accordance with an embodiment of the present disclosure;

[0012] FIG. 2 is an illustration of a magnified view of a part of an image generating block, in accordance with an embodiment of the present disclosure; and

[0013] FIG. 3 is an illustration of an arrangement of light emitting diodes in an implementation of a backlight module, in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION OF EMBODIMENTS

[0014] The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.

[0015] In an aspect, the present disclosure provides an image generating block for use in a digital signage, the image generating block comprising: an array of liquid crystal display (LCD) cells covered by a glass covering on a first side of the array of LCD cells; a backlight module having at least one array of light emitting diode (LED) printed circuit boards (PCBs), wherein the backlight module is configured to illuminate a second side of the array of LCD cells, using the at least one array of LED PCBs; and an optical layer arranged between the second side of the array of LCD cells and the backlight module, wherein the optical layer is configured to adjust an incident angle and a wavelength of the illumination from the backlight module, the optical layer comprising: a reflector foil arranged adjacent to the backlight module, wherein the reflector foil is configured to provide a passage for the illumination from the backlight module to pass through the optical layer towards the array of LCD cells, a diffuser layer configured to disperse the illumination from the backlight module within the optical layer, wherein the diffuser layer is separated from the reflector foil by means of at least one optical foil standoff forming a first air gap between the diffuser layer and the reflector foil, a polarization layer arranged adjacent to the diffuser layer, wherein the polarization layer is configured to manipulate the illumination dispersed by the diffuser layer into a predefined orientation, and an amplification foil arranged in proximity to the polarization layer, wherein the amplification foil is configured to reflect a first part of the illumination straying away after polarization, back to the reflector foil, and guide a second part of the illumination towards the second side of the array of LCD cells.

[0016] The disclosed image generating block, with the optimally designed optical layer and enhanced illumination from the backlight module, is configured to improve the colour rendering ability of the array of LCD cells. Moreover, the image generating block improves the quality of display by adjusting a thermal environment therewithin, by placing the backlight module and the array of LCD cells away from each other as well as from the optical layer to introduce the first air gap and the second air gap therebetween. Furthermore, the image generating block is adapted to adjust the brightness of the digital signage effectively without additional power consumption requirements. Furthermore, the image generating block is configured to eliminate the appearance of light spots and other optical anomalies due to the efficient design of the optical layer. Furthermore, by customizing an arrangement of one or more LEDs on the at least one LED PCB, and by utilizing the optical layer, the image generating block achieves a combined requirement of high colour temperature, energy efficiency, and superior display quality (uniform light distribution) in digital signages of any size.

[0017] Throughout the description, the term "digital signage" refers to an arrangement of mechanical, electronic, software and firmware components configured for displaying information (such as, advertisements, alerts, news, etc.) received from an input source, on either side to allow user(s) to view from multiple angles and / or locations. The digital signage is designed to cater for indoor, as well as outdoor environmental conditions such as, weather, temperature, water, humidity, wind loading, etc., and is configured to withstand harsh environmental conditions such as, high humidity, extreme temperatures, vandalism and / or accidents. The digital signage can be clearly viewed by a mass audience from varying distances and thus may be adapted with varied fixing mechanisms to suit the varied implementational requirements such as, but not limited to, ground fixation (with suitable foundations), wall mounting, integration with external structures e.g., bus-stops, train stations, etc. For example, the digital signage may refer to any of an electronic sign board, a notification panel, a display board, a theatre screen. Herein, the term "input source" may refer to a cloudbased data repository, live broadcast station, a local data repository.

[0018] Throughout the description, the term "image generating block" refers to a collective assembly of optical, mechanical, electrical, and electronic components that collectively operate to enable display of an input media, for example, still images, graphics interchange format (GIF) images, videos, scrolling texts, ticker texts, marquee texts, live feeds. Optionally, the image generating block may receive the input from the input source via an interface. The image generating block is configured to generate input in any colour or monochrome.

[0019] The term "interface" used herein refers to an ethernet port, a digital visual interface (DVI), a video graphics array (VGA), a serial port, a peripheral component interconnect express (PCIe), a thunderbolt, a universal system bus port, a high-definition multimedia interface (HDMI) port or any such arrangement that enables a connection to the input source. The term "connection" used herein refers to any of a wired connection, and wireless connection. The term "wired connection" used herein may refer to a connection to the local repository like a personal computer, a laptop, a tablet, a server, a pen drive, an external hard drive, any such external storage device. The term "wireless connection" used herein may refer to a connection over an ethernet, an internet, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), an access network (AN), a radio access network (RAN) or any such connection to receive the input.

[0020] The term "array of liquid crystal display (LCD) cells" refers to an arrangement of LCD cells in a manner to display the input from the input source. The LCD cells are electronically modulated optical device that utilizes light-modulating properties of liquid crystals to produce images or videos in colour or monochrome. Notably, the liquid crystal used in the array of LCD cells may change orientation when electrically triggered to modulate an illumination passing through the liquid crystals. The term "illumination" used herein refers to light produced by part of the image generating block, namely, the backlight module, corresponding to the input received from the input source. The illumination may be, for example, a white light, a monochromatic light, or a polychromatic light.

[0021] Moreover, the array of LCD cells comprises the first side and the second side. The first side is covered by a glass covering. The first side refers to the side of the array of LCD cells which is configured to display the input received and is visible to the user(s) from outside in an environment where the digital signage is placed. It may be appreciated that the input received from the input source is reproduced on the first side of the array of LCD cells, as an output. The first side of the array of LCD cells may comprise a plurality of colour filters for enhancement of colour accuracy, resolution and efficient regulation of brightness of the array of LCD cells. The second side, opposite to the first side, is made up of a plurality of liquid crystals to modulate the illumination.

[0022] The colour filters are typically made up of organic dyes, pigments or quantum dots (semiconductor nanocrystals). The colour filters are configured to selectively absorb and transmit specific wavelengths of light, corresponding to the primary colours i.e., red, green, and blue (RGB). Moreover, the glass covering on the first side protects the array of LCD cells from external factors such as dust. The glass may be a sapphire glass, a chemically strengthened glass, an anti-reflective glass, a laminated glass, a tempered glass, a gorilla glass or any such suitable glass that can withstand external factors and provide desirable characteristics such as enhanced clarity and readability, lightweight, good resistance to impact, penetration and scratches.

[0023] Moreover, the image generating block comprises the backlight module having at least one array of light emitting diode (LED) printed circuit boards (PCBs). The backlight module is configured to produce the illumination corresponding to the input utilizing the at least one array of light emitting diode (LED) printed circuit boards (PCBs). The illumination from the backlight module illuminates the second side of the array of LCD cells comprising the plurality of liquid crystals which are electrically triggered to modulate the illumination in a specific manner in order to reproduce the input received from the input source on the first side of the array of LCD cells. The term "array of LEDs", as used throughout the description, refers to an arrangement of one or more LEDs on PCBs. The term "printed circuit boards (PCBs)" may refer to copper sheets laminated onto a non-conductive substrate such as flame-retardant glass-reinforced epoxy laminate, fiber glass. Optionally, the at least one array of LED PCBs may be configured to produce the illumination which may be white light, monochromatic light or polychromatic light based on the input received. In this regard, the illumination from the backlight module may be modified by changing or modifying types of LEDs used in the at least one array of LED PCBs.

[0024] Optionally, each LED PCB amongst the at least one array of LED PCBs is spatially positioned at a calculated spatial distance from an array of LCD cells and intermediate optical layers (including the reflector foil, the diffuser layer, the polarization layer and the amplification foil). Moreover, each LED PCB comprises one or more LEDs, each arranged thereon in a predefined pattern (spatially) and spacing. It may be appreciated that the predefined pattern is empirically optimized through simulation and testing to ensure uniform light distribution across a panel comprising the array of LCD cells, when combined with the optical layer structure and the defined spacing between layers. The spacing between each of one or more LEDs, is optimized to allow sufficient diffusion and blending of light from adjacent LEDs before it reaches the display surface. The result is a continuous illumination field with no perceptible hotspots, cold spots, or glare zones. In this regard, both, a number of individual LED PCBs amongst the at least one array of LED PCBs as well as a number of the one or more LEDs, may vary depending on the size of the digital signage, specifically, depending on the size of the array of LCD cells. It may be appreciated that the spatial distance between the at least one array of LED PCB and the panel comprising the array of LCD cells, as well as the spacing between each of one or more LEDs are critical design parameters, which affect the performance of the image generating block.

[0025] In an example, the backlight module may consist of 32 individual LED PCBs for a digital signage of dimension of 75 inches. In another example, the backlight module may consist of 24 individual LED PCBs for a digital signage of dimension of 65 inches. In yet another example, the backlight module may consist of 18 individual LED PCBs for a digital signage of dimension of 55 inches. In yet another example, the at least one LED PCB (of the backlight module) comprises a fixed and repeatable array of 224 LEDs arranged in a predefined spatial pattern.

[0026] Optionally, both, the number of individual LED PCBs amongst the at least one array of LED PCBs as well as the number of the one or more LEDs, is varied depending on a desired colour rendering index (CRI) to obtain optimal brightness of the output of the image generating block.

[0027] Furthermore, the arrangement of the one or more LEDs is optimized to achieve a colour rendering index (CRI) of at least 90 ensuring natural colour reproduction, optimal brightness uniformity across the LCD surface, and suppression of light artifacts, including hotspots and glare. The arrangement of the individual LED is optimized such that energy consumption is reduced by minimizing over-illumination and reducing the total power load required for acceptable image quality.

[0028] The term "CRI" refers to a metric that evaluates an ability of the image generating block to reproduce colours in the input received. Particularly, the CRI refers to how well the backlight module renders colours of the input on the array of LCD cells, compared to a reference light source of a same colour temperature. The term "colour temperature" used herein refers to a hue of illumination of the backlight module expressed as a temperature with reference to illumination of a reference illuminant. The reference illuminant may be an incandescent light source, an ideal light source or a natural light source. Notably, the CRI value ranges from 0 to 100, where 100 represents the maximum possible accuracy in colour rendering, equivalent to the natural light source or the ideal light source. Notably, a higher CRI values indicate better colour rendering. For example, a backlight module with a CRI of 90 will render colours of the input received more accurately than one with a CRI of 70.

[0029] Optionally, the one or more LEDs may be of same type or different types, in order to replicate a colour profile of the input received at the output. The term "colour profile" refers to colours represented as tuples of numbers with defined ranges for each component of primary colours (RGB). The one or more LEDs on each LED PCB amongst the at least one array of LED PCBs, are arranged in the predefined pattern to accurately reproduce colour profile of the input. The arrangement of the one or more LEDs achieves the technical effect of maintaining optimal brightness of the image generating block without any light spots or other optical anomalies to improve quality of input reproduction in the digital signage. Optionally, the predefined pattern comprises each of the one or more LEDs to be spaced apart from remaining of the one or more LEDs by a range from 10 to 50 mm. In this regard, each of the one or more LEDs are spaced apart from the remaining of the one or more LEDs by 10, 20, 30, 40 or 45 mm up to 15, 25, 35, 45 or 50 mm. A technical effect of homogenous illumination is achieved by arranging the one or more LEDs in the predefined pattern.

[0030] Regarding the predefined pattern and spacing arrangement of the one or more LEDs, such arrangement yields a high colour rendering index (such as CRI > 90), ensuring that output of the image generating block (i.e., images and video content displayed via the display / the panel comprising the array of LCD cells) appear natural and colour-accurate, particularly in outdoor environments or under mixed lighting conditions. Notably, such high CRI performance of the image generating block is achieved without requiring high current operation of LEDs or excessive backlight intensity, leading to reduced overall energy consumption and extended LED lifespan. Optionally, the aforementioned spacing between adjacent LEDs is selected based on the target display size and desired brightness gradient to ensure even light distribution without local intensity peaks. In certain implementations, this spacing is selected based on the diagonal size of the LCD and the desired luminance profile. This dimensioning balances diffusion needs with LED efficiency, allowing for fewer LEDs without compromising on image quality.

[0031] Optionally, alternatively, the backlight module may also comprise one or more fluorescent lights.

[0032] Furthermore, the image generating block comprises the optical layer which is configured to adjust the incident angle and the wavelength of illumination from the backlight module in such a way that enables accurate reproduction of the input on the digital signage, while optimally managing the brightness of the digital signage. The term "incident angle" refers to an angle at which the illumination from the backlight module is directed towards the array of LCD cells. The wavelength of the illumination is dependent on the type of illumination. For example, if the illumination is white light or a polychromatic light, then the wavelength of the illumination can be varied so that a red light or blue light may be dispersed as per requirement. The optical layer is positioned between the array of LCD cells and the backlight module.

[0033] In this regard, the optical layer is a composite layer comprising a plurality of layers manipulating and directing the illumination from the backlight module towards the array of LCD cells. Optionally, a layer of the optical layer which is closest to the second side of the array of LCD cells may be termed as the uppermost layer of the optical layer.

[0034] Optionally, the optical layer is configured to adjust various properties of the illumination such as brightness, incident angle, direction, and wavelength. The optical layer serves to improve the CR.I of the image generating block to reproduce the input accurately on the first side of the array of LCD cells as output. Moreover, the plurality of layers of the optical layer operating together with the backlight module to provide a high-performance digital signage with enhanced brightness, uniform light distribution, and optimal colour rendering index (CRI).

[0035] Moreover, the optical layer comprises the reflector foil. The reflector foil is arranged adjacent to the backlight module. The term adjacent may refer to a distance of 0 to 0.1 mm. For example, the reflector foil may be positioned at a distance of 0 mm (i.e., attached to the backlight module) or may be positioned at a distance from 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08 or 0.09 mm up to 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.1 mm, from the backlight module. Optionally, the reflector foil may be a non-metallic, and colour-neutral reflector designed to optimize the illumination in the image generating block. Optionally, the reflector foil is configured to exhibit over 98% reflectance for various wavelength of the illumination, for example, a white light, or a red light or any other light in visible spectrum, thereby enhancing brightness and efficiency of the image generating block.

[0036] Optionally, the reflector foil is of a thickness ranging between 30 to 170 micrometers (pm). In this regard, the thickness of the reflector foil may range from 30, 50, 70, 90, 110, 130, 150 or 160 pm up to 40, 60, 80, 100, 120, 140, 160 or 170 pm.

[0037] Optionally, the reflector foil is a multilayer polyester-based film. In this regard, the reflector foil may have thermal stability, chemical stability, high tensile strength, reflectivity associated with polyester. For example, the reflector foil may be a biaxially oriented polyethylene terephthalate film, a thermoplastic resin film or any such suitable films. Optionally, the thickness of the multilayer polyester film may be up to 100 micrometer (pm). The thickness is adjusted as per a thermal environment within the image generating block. The "thermal environment" refers to a temperature profile (rise and fall of temperature) within the image generating block due to the produced illumination.

[0038] Optionally, the reflector foil has a third side facing away from the backlight module, wherein the third side of the reflector foil is coated with a reflective material. Optionally, the reflector foil has a fourth side attached to the backlight module by means of at least one of: an adhesive, an additional fixing layer, at least one attachment. Herein, the terms "third side" and "fourth side" as used herein refer to 2 opposite sides of the reflector foil, which is implemented as a film, as discussed above. In this regard, the third side of the reflector foil is configured to reflect illumination within the image generating block. For example, the third side of the reflector foil is configured to reflect illumination straying away, namely the first part of the illumination, from any other layer amongst the plurality of layers of the optical layer. The reflective third side is arranged to face in the direction of the second side of the array of LCD cells. Optionally, the third side may be textured or prismed to reflect the first part of the illumination at an optimum reflection angle.

[0039] Moreover, the fourth side faces the backlight module. In this regard, the adhesive or the additional fixing layer may be selected based on the thermal environment of the image generating block, and other requirements such as optical clarity and durability. The fourth side of the reflector foil may be attached by means of any of: optically clear adhesives (OCA), double-sided adhesive tapes, acrylic foam tapes, epoxy-based ultraviolet-curable adhesives, silicone adhesives, thermally conductive adhesives. The additional fixing layer may be utilized based on the thermal environment of the image generating block to dissipate a heat generated by the backlight module to provide additional thermal protection to the reflector foil. The adhesive or the additional fixing layer protects the reflector foil in the thermal environment of the image generating block to avoid warping in sever thermal condition. Herein, the term "at least one attachment" refers to mechanical elements adapted to hold the fourth side of the reflector foil to face or be in contact with the backlight module. For example, the at least one attachment may be implemented as clamps, screws, bolts, magnets, and so on.

[0040] Optionally, a protective film is applied to both the third side and the fourth side of the reflector foil. The protective film is configured to protect the texture, reflectivity and other physical properties of the reflector foil so as to improve an operational life of the reflector foil.

[0041] Optionally, the reflector foil comprises at least one hole corresponding to a position of one or more LEDs arranged on the at least one array of LED PCB, to provide the passage for the illumination from the backlight module to pass therethrough. Notably, the one or more LEDs are arranged in a specific pattern and in a specific spatial position on the at least one array of LED PCB (of the blacklight module). To allow passage of illumination through the optical layer (i.e., the reflector foil) to reach the array of LCD cells, the reflector foil is punched to include at least one hole which corresponds to the said specific spatial position of the one or more LEDs. In simple terms, the reflector foil is engineered with a patterned array of precision-aligned perforations or holes, where each hole corresponds exactly to the spatial position of a LED mounted on the at least one array of LED PCBs. It may be appreciated that the at least one hole is strategically positioned and dimensioned to allow the emitted illumination to pass directly through the reflector foil while minimizing lateral scattering and light leakage. The dimensions of the at least one hole are tailored in diameter and shape (such as circular, rectangular, square, trapezoidal, triangular and so on) to match footprint of each LED, ensuring controlled beam entry into the optical layer and supporting beam collimation in early optical path (during transmission through the optical layer). This improves the directional integrity of the illumination, enhances light throughput, and contributes to uniform brightness distribution across the array of LCD cells, especially when implemented in large-format or outdoor signage applications.

[0042] For example, each LED PCB amongst the at least one array of LED PCB, has a defined arrangement of 224 LEDs arranged in a predefined pattern, and the reflector foil needs to have an opening i.e., hole for every / each / individual LED chips so that every / each / individual LED is visible and so that illumination from each LED can pass through the reflector foil. Notably, introducing passage (namely the at least one hole) also allows the illumination to follow a specific direction instead of scattering when produced. Thus, the reflector foil allows easy manipulation of the illumination from the backlight module as per requirements in the further steps.

[0043] Furthermore, a design of perforating the reflector foil (by adding the at least one hole) enables the use of high-efficiency backlighting by reducing light waste and decreasing the need for excessive LED power, thus enhancing energy efficiency. Additionally, by shaping the illumination pathway immediately near the light emission source (namely the backlight module), the aforementioned design facilitates precise optical manipulation within the subsequent layers of the optical layer (namely, the diffuser layer, the polarization layer, and the amplification foil).

[0044] Advantageously, the aforementioned design (i.e., adding the at least one hole in coordination with the LED PCB layout) supports automated diecutting, laser-punching techniques or any such suitable techniques to produce consistently aligned reflector foils in mass production. This improves optical consistency across units and simplifies assembly processes. The aforementioned design also provides ease of maintenance by allowing access to individual LEDs if required.

[0045] Moreover, the optical layer comprises the diffuser layer positioned in parallel to the reflector foil and the backlight module. The diffuser layer is configured to disperse the illumination from the backlight module within the image generating block into lights of different wavelengths, to improve the optical distribution of the illumination. The diffuser layer is made up of semi-transparent or transparent material; for example, the diffuser layer may be made from material of about 78% transparency. Optionally, the diffuser layer is made of an opalescent material. In this regard, the diffuser layer may be made up of material such as tiffany glass, milk glass, opal acrylic, ceramics, opal glass, opal plastics, which exhibits a milky or pearly translucence.

[0046] The diffuser layer is separated from the reflector foil by means of at least one optical foil standoff. The term "optical foil standoff' refers to a spikelike structure which is designed to withstand thermal environment within the image generating block and to hold the diffuser layer in a suitable position, for example, in a middle section, to prevent sagging. The optical foil standoff may be made up of thermoplastic materials, ceramics, metals, metal alloys or any such suitable materials. The technical effect achieved by utilizing the optical foil standoff is to provide effective support within the image generating block without adding significant bulk or material cost. Optionally, the diffuser layer is separated from the reflector foil attached to the backlight module by forming the first air gap. The first air gap formed therebetween is optimally constructed to allow adequate dispersion of the illumination generated by the backlight module and to maintain stability of the thermal environment within the image generating block.

[0047] Optionally, the diffuser layer is positioned at a distance in range of 10 to 50 mm, from the backlight module. In this regard, the distance between the diffuser layer and the backlight module may range from 10, 20, 30, 40 or 45 mm up to 15, 25, 35, 45 or 50 mm. The technical effect is even distribution of the illumination across the diffuser layer.

[0048] Optionally, the diffuser layer is of a thickness in range of 1 to 5 mm. In this regard, the thickness of the diffuser layer may range from 1, 1.5, 2, 2.5, 3, 3.5, 4 or 4.5 mm up to 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5 mm. The thickness of the diffuser layer is specified to ensure optimal diffusion of the illumination while maintaining the structural integrity of the image generating block.

[0049] Furthermore, the optical layer comprises the polarization layer which is adjacently arranged to the diffuser layer. The polarization layer is configured to manipulate the illumination dispersed by the diffuser layer into a predefined orientation. The term "predefined orientation" refers to a specific angular alignment of the light dispersed by the diffuser layer, relative to a transmission axis of the polarization layer. Notably, the transmission axis refers to an axis arranged perpendicular to a plane of the diffuser layer, along which the light (produced by the backlight module and dispersed by the diffuser layer afterwards) passes to reach the array of LCD cells. The predefined orientation is set depending on properties of the liquid crystal used in the array of LCD cells. A suitable value of the predefined orientation leads to optimized light / illumination transmission efficiency and reduced angular colour shift. The suitable value of the predefined orientation also ensures compatibility with polarization-sensitive elements such as liquid crystal cells. The polarization layer aligns dispersed lights of different wavelength (of the illumination) in a single transmission direction towards the array of LCD cells. For example, the illumination being a white light or polychromatic light includes lights of multiple wavelengths, and after passing through the diffuser layer, they are dispersed throughout the image generating block. The polarization layer is configured to align the defused / dispersed lights of different wavelengths in a single transmission direction (i.e., towards the array of LCD cells). Optionally, the polarization layer may refract the diffused light (originally emitted from the backlight module and diffused by the diffuser layer), internally within the optical layer, to reduce the visibility of individual LEDs from the array of LED PCBs, enhancing overall image uniformity and thereby reducing appearance of light spots in the digital signage. In other words, the polarization layer reduces the visibility of individual LEDs, thereby suppressing localized luminance artifacts in the digital signage and enhancing overall image uniformity.

[0050] Optionally, the polarization layer comprises a first polarizer and a second polarizer, wherein the first polarizer is oriented at a first polarizing angle relative to a plane of the diffuser layer and the second polarizer is oriented at a second polarizing angle relative to the plane of the diffuser layer, respectively. Notably, a combined orientation of the first polarizer and the second polarizer is configured to enhance polarization uniformity and suppress angular colour shift of the illumination entering the array of LCD cells. The term "first polarizing angle" used herein refers to an angle at which a transmission axis of the first polarizer is arranged / oriented relative to the plane of the diffuser layer. Similarly, the term "second polarizing angle" used herein refers to an angle at which a transmission axis of the second polarizer is arranged / oriented relative to the plane of the diffuser layer. In this context, the first and second polarizing angles are measured in degrees from a horizontal optical reference. The horizontal optical reference may refer to a baseline reference axis parallel to the plane of the diffuser layer along a horizontal axis of the image generating block. It may be appreciated that the first and second polarizing angles may be of the same value or of different values depending on the degree of polarization required to suppress the angular colour shift of the illumination (produced by the backlight module).

[0051] Notably, the combined orientation of the first polarizer and the second polarizer dependent on the first and second polarizing angles. The angled orientation (of the first and second polarizer) relative to the transmission axis is selected to achieve enhanced polarization uniformity by manipulating an orientation of the illumination (i.e., light produced by the backlight module) dispersed by the diffuser layer before they reach the amplification foil and the second side of the array of LCD cells. It may be appreciated that the angular separation between the two polarizers is optimized to reduce angular colour shift and to improve contrast consistency across a range of viewing angles.

[0052] In this regard, the first polarizer set at the first polarizing angle and the second polarizer set at the second polarizer angle, in combination (or collectively), are configured to manipulate direction of the dispersed illumination to achieve a desired angle of transmission through the polarization layer to ensure colour replication / reproduction of the illumination is achieved at the output. For example, the first polarizer is oriented at the first polarizing angle may be 135 degrees with respect to the plane of the diffuser layer, and the second polarizer is oriented at the second polarizing angle may be 45 degrees with respect to the plane of the diffuser layer to reduce angular colour shift and to improve contrastconsistency across a range of viewing angles. It may be appreciated that the first and second polarizing angles may be fixed (e.g., at 45° for the first polarizer and at 135° for the second polarizer respectively) or selected based on an empirical optimization wherein the first polarizing angle is set at a value in a range from 40° up to 50° and the first polarizing angle is set at a value in a range from 130° up to 140°. In this regard, the empirical optimization is suitably selected based on a given display geometry and backlight configuration.

[0053] Moreover, a dual-polarizer arrangement (i.e., arranging the first and second polarizer at the first and second polarizing angles respectively) ensures that only light (namely the illumination) with a desired orientation / polarization is transmitted to the array of LCD cells, while lights with unwanted polarization states are either redirected to follow the desired polarization or absorbed, thereby enhancing the overall optical efficiency of the image generating block. Furthermore, unlike standard single-polarizer systems, the dual-polarizer arrangement i.e., the use of two angularly offset polarizers (namely, the first and second polarizers) allows more precise control over polarization directionality, enabling correction of light artifacts and improving colour fidelity in high- brightness or wide-format digital signage.

[0054] It may be appreciated that the first polarizer is positioned adjacent to the diffuser layer facing the backlight module and the second polarizer is positioned in between the first polarizer and the amplification foil of the optical layer.

[0055] Optionally, the polarization layer is of thickness in a range between 0.1 to 1 mm. In this regard, the thickness of the polarization layer may be 0.1, 0.3, 0.5, 0.7 or 0.9 mm up to 0.2, 0.4, 0.6, 0.8 or 1 mm. The thickness of the polarization layer is determined based on manipulation required on the illumination.

[0056] The optical layer comprises the amplification foil which is arranged in proximity to polarization layer. The term proximity used herein refers to a separation distance which may range from 0 to 0.1 mm. The amplification foil reflects the first part of the illumination which may be straying away after polarization, back to the reflector foil. The first part of the illumination refers to a part of the illumination which is not directed in the desired angle even after passing through the polarization layer. Such part of the illumination may cause light spots in the output and may degrade quality of the output. By reflecting the first part of the illumination back to the reflection foil, the direction of the first part of the illumination may be adjusted as required. The first part of the illumination is afterwards reflected back by the reflection layer towards the diffuser layer and thereby effectively recycling the straying first part of the illumination and increasing the overall brightness of the image generating block without additional power requirement. For example, the reflector foil and the amplification foil in combination may enhance the luminance gain up to 111% making the display signage brighter. Thus, reducing the requirement of increasing number of LED PCBs or operation power input to the exiting LED PCBs in the backlight module making the image generating block energy efficient.

[0057] Moreover, the amplification foil is also configured to guide the second part of the illumination in the single transmission direction towards the second side of the array of LCD cells. The second part of the illumination refers to a part of illumination which is manipulated at the desired angle. The amplification foil thus improves polarization efficiency, and in combination with the reflector foil the amplification foil is configured to enhance reflectivity of the illumination within the image generating block, significantly boosting output and reducing power consumption.

[0058] Optionally, the amplification foil has a fifth side and a sixth side, and wherein each of the fifth side and the sixth side is laminated with a diffused polycarbonate. In this regard, the amplification foil is a multilayer polyester-based film. Herein, the terms "fifth side" and "sixth side" as used herein refer to 2 opposite sides of the amplification foil which may be implemented as a film. The fifth side of the amplification foil is placed facing the diffuser layer (positioned adjacently) and the sixth side is placed facing the array of the LCD cells forming an uppermost layer of the optical layer. By coating the fifth and the sixth sides of the amplification foil with the diffused polycarbonate, the technical effects of even light distribution, reduction of light spots glare, and unwanted shadows, increased impact resistance, durability, safety and longevity are achieved.

[0059] Notably, the diffused polycarbonate layered on the fifth and sixth sides improves the uniform distribution of illumination passing through or reflected by the amplification foil. This layering advantageously suppresses light hotspots, reduces glare, and mitigates visual artifacts such as shadowing or edge pooling, especially at high luminance levels or when viewed from wide angles. By maintaining consistent light redirection, the laminated sides (namely, the fifth and the sixth sides) of the amplification foil contribute significantly to visual clarity and uniformity of a display (i.e., the image generating block of the present disclosure).

[0060] Moreover, the diffused polycarbonate exhibits high impact resistance and thermal durability. Thus, the diffused polycarbonate offers added protection to the amplification foil and other internal optical structures. In other words, the diffused polycarbonate lamination shields the amplification foil from deformation due to pressure, heat cycling, or mechanical shock and any such conditions common in outdoor, high- traffic, or transportable digital signage installations.

[0061] Furthermore, unlike conventional diffusion films that serve either optical or mechanical roles, the polycarbonate lamination in this configuration enables dual-function integration (i.e., improvement of optical quality and enhancement of mechanical properties). This simplifies the overall fabrication process (including stacking and layering optical components). Additionally, laminating the amplification foil using diffused polycarbonate enhances the dimensional stability and lifespan of the optical layer while preserving high optical gain efficiency from the underlying amplification foil.

[0062] Furthermore, this design of laminating both fifth and sixth sides of the amplification foil is particularly advantageous in ruggedized applications (such as outdoor environment where the image generating block may be subjected to mechanical stress, temperature extremes, moisture, humidity, water exposure, dust, dirt, or corrosive environment and high electromagnetic interference), where display systems must balance high brightness, uniform image fidelity, and environmental resilience without compromising on energy efficiency or serviceability. This dual-sided lamination (i.e., lamination of the fifth and sixth sides) is engineered to serve multiple synergistic functions that extend beyond basic diffusion in such scenarios.

[0063] Optionally, the array of LCD cells is positioned at a distance from the optical layer forming a second air gap therebetween, wherein said distance is in a range of 1 to 6 millimeters (mm). Specifically, the second air gap (defined by the said distance in the range of 1 to 6 mm) separates the array of LCD cells from the uppermost layer of the optical layer, i.e., the amplification foil of the optical layer. In this regard, the amplification foil and the array of LCD cells may be separated by the second gap established through structural separation components such as optical foil standoffs, aluminum extrusions, precision gaskets or any such suitable separation means.

[0064] Notably, the second air gap is engineered as a multi-functional separation interface that plays a critical role in optimizing the performance and longevity of the display by managing internal heating. In this regard, the second air gap operates as a passive thermal regulation chamber, allowing heat dissipation and preventing direct thermal conduction between the heat-emitting optical layer and the array of LCD cells which is sensitive to heat. This thermal decoupling functionality achieved by the second air gap aids in stabilizing internal temperature profiles, reducing the risk of thermal degradation or pixel malfunction over extended usage.

[0065] Optionally, the distance between the array of LCD cells and the optical layer may range from 1, 2, 3, 4, or 5 mm up to 2, 3, 4, 5, or 6 mm, to ensure a proper separation is achieved between the amplification foil and the second side of the array of LCD cells, establishing the second air gap. A technical effect achieved from maintaining such distance is that the second air gap becomes suitably wide for maintaining required internal temperature profiles to ensure excellent output quality and uniform light distribution.

[0066] Additionally, the second air gap acts as an optical refractive buffer, regulating an angle at which the illumination enters the array of the LCD cell, thereby enhancing brightness uniformity and minimizing colour bleeding or halo artifacts. In high-luminance applications, such as outdoor digital signage, this optical function (i.e., regulating the angle at which the illumination enters the array of the LCD cell) significantly improves clarity and image fidelity.

[0067] Furthermore, the second air gap provides a mechanical shock isolation function by physically decoupling the array of LCD cells from the optical layer, thereby protecting delicate optical components from vibration, impact, and stress especially in outdoor environment or mobile installations subjected to environmental forces or vandalism.

[0068] Additionally, experimental evaluation demonstrates that this structured air gap (namely the second air gap) improves overall light uniformity at the array of LCD cells by 15-20%, compared to traditional configurations lacking such a controlled spatial layer. Furthermore, the engineered dimensioning and the use of modular structural components (such as optical foil standoffs, aluminum extrusions, precision gaskets and so on) also enable manufacturability and ease of service access in field deployments.

[0069] Optionally, the operational workflow between the plurality of layers of the optical layer, backlight module and the array of LCD cells ensures that the input received from the input source is reproduced with colour rendering efficiency with optimum quality.

[0070] For example, the backlight module emits white light. The backlight module may include fluorescent light or one or more LEDs as a source of illumination. The optical layer disperses the white light utilizing the diffuser layer, polarizes and aligns the white light in a single transmission direction utilizing the polarization layer and the reflector foil. The aligned white light is then directed towards the second side of the array of LCD cells comprising the plurality of liquid crystals and the first side of the array of LCD cells comprising colour filter to pixelate the aligned white light into corresponding subpixel of primary colours red, green, or blue as per the input received. The array of LCD cells further controls an amount of white light that can pass through the colour filter based on a determined the intensity of each colour as estimated from the input to produce the output as combination of light intensities from the red, green, and blue subpixels.

[0071] Optionally, the image generating block may comprise a plurality of support structures, heat sinks, heat exchangers, air channel, and the like to maintain structural and operational integrity of the image generating block. Herein, the above-mentioned support structures are collectively operable for exchanging heat within the image generating block. The heat exchanger may be a dedicated device. Alternatively, heat exchange functionality may be provided by an arrangement of components as mentioned above.

[0072] Optionally, the image generating block may comprise an inbuilt electrical components such as an electrical circuit for deriving required power from an external source. Optionally, image generating block may derive power from an alternating current source, a battery, a solar panel, onsite renewable energy source, remote renewable energy sources or any such suitable arrangement.

[0073] Optionally, the image generating block may be operable via a control unit which regulates and monitors an operational status of various components of the image generating block. The control unit may be a microprocessor, a microcontroller, a on chip control unit, a central processing unit, or any such suitable arrangement. The control unit may also comprise integrated sensor (for example, but not limited to, heat sensor, temperature sensor, optical sensor, confocal chromatic sensor) arrangements to monitor, adjust and operate various components of the image generating block.

[0074] The image generating block may also comprise any number of auxiliary components, parts, connecting elements as required apart from afore disclosed components.

[0075] Optionally, image generating block is air-tight. Beneficially, air-tight nature of the image generating block enhances efficiency and operations of the image generating block. For example, air-tight image generating block eliminates chances of dust, dirt, other particulates, moisture and humidity from entering the image generating block, as well as maintains a consistent internal temperature of the lOimage generating block.

[0076] Optionally, the image generating block is fabricated using a glass covering, an aluminum housing for the backlight module, aluminum extrusion layers implemented as various components of the optical layer. In this regard, a first aluminum extrusion layer is implemented as the reflector foil, a second aluminum extrusion layer is implemented as the diffuser layer, a third aluminum extrusion layer is implemented as the polarization layer, and so on. The disclosed image generating block is adapted with a custom LED backlight module comprising customized LED PCBs and LED chips that are optimized for specific performance needs, including geometry, colour temperature (10000-12000 kelvin), durability, and power output. Additionally, the image generating block comprises multiple advanced optical layers implemented as extended super reflector (ESR) and enhanced brightness improvement component (EBIC) foils to enhance light amplification and efficiency. The image generating block is adapted for homogeneous light distribution resulting from minimal and consistent spacing between LEDs and the LCD cell, facilitated by additional optical layers to diffuse light evenly. Moreover, the image generating block is adapted for enhanced colour rendering index (CRI) by achieving natural colour reproduction through a carefully balanced high colour temperature. The image generating block is further adapted for passing the blue light through a Dual Brightness Enhancement Films (DBEF) layer, while other wavelengths are reflected until they change wavelength and can pass through. Notably, reflective layers like ESR. 100 improve overall brightness by reflecting light back into the display.

[0077] EXPERIMENTAL PART

[0078] An image generating block for use in a display signage was implemented in an outdoor bright display screen (hereafter, referred to as "outdoor screen") adapted to be operated in a hot environment. In this regard, the outdoor screen was capable of operating globally in all environments, from extremely hot areas with direct sunlight to extremely cold areas with long winter nights.

[0079] In an experiment, the image generating block (for outdoor use) was equipped with 224 LEDs in each LED PCBs of its backlight module. The image generating block comprised a display / a panel comprising an array of LCD cells. By maintaining a fixed LED count of 224 per PCB and optimizing both the horizontal spacing between individual LEDs on the PCB and the vertical distance between the LED PCB and the LCD array, high-quality image output characterized by enhanced brightness uniformity, improved colour stability, and reduced optical noise across a wide viewing angle, was achieved. This precision configuration exhibited satisfactory thermal performance and optimized power requirement for the backlight system.

[0080] DETAILED DESCRIPTION OF THE DRAWINGS

[0081] Referring to FIG. 1, illustrated is an image generating block 100, in accordance with an embodiment of the present disclosure. The image generating block 100 comprises an array of liquid crystal display (LCD) cells 102 having a first side 102A covered by a glass 104 and a second side 102B; a backlight module 106 having at least one array of light emitting diode (LED) printed circuit boards (PCBs), wherein the backlight module is configured to illuminate a second side 102B of the array of LCD cells 102; and an optical layer 108 arranged between the second side 102B of the array of LCD cells 102 and the backlight module 106. The optical layer 108 is separated from the array of LCD cells 102 by a distance DI forming a second air gap 122. The optical layer 108 comprises a reflector foil 110 arranged adjacent to the backlight module 106 to provide a passage for the illumination from the backlight module 106 to pass through the optical layer 108 towards the array of LCD cells 102; a diffuser layer 112 separated from the reflector foil 110 by a distance D2 by means of at least one optical foil standoff 114 forming a first air gap 116 between the diffuser layer 112 and the reflector foil 110; a polarization layer 118 arranged adjacent to the diffuser layer 112, and an amplification foil 120 arranged in proximity to the polarization layer 118. As shown, the reflector foil 110 comprises a third side 110A facing away from the backlight module 106 and a fourth side HOB adjacent to the backlight module 106. As shown, the amplification foil 120 comprises a fifth side 120A adjacent to the polarization layer 118 and a sixth side 120B facing the array of LCD cells 102. As shown in FIG. 1, the polarization layer 118 comprises a first polarizer 118A facing the backlight module 106 and a second polarizer 118B in between the first polarizer 118A and the fifth side 120A of the amplification foil 120.

[0082] Referring to FIG. 2, illustrated is a magnified view of a part of an image generating block 200, in accordance with an embodiment of the present disclosure. The image generating block 200 comprises a polarization layer 218 having a first polarizer 218A and a second polarizer 218B to manipulate illumination within the image generating block 200.

[0083] Referring to FIG. 3, illustrated is an illustration of an arrangement of light emitting diode in an implementation of a backlight module 306, in accordance with an embodiment of the present disclosure. The backlight module comprises of one or more LED 308 arranged on a PCB 310 in a predefined pattern with each LED 308 spaced apart from remaining LEDs.

[0084] Aforementioned FIGs. 1-3 are merely exemplary in nature, which should not unduly limit the scope of the claims herein. A person skilled in the art will recognize many variations, alternatives, and modifications of embodiments of the present disclosure.

Claims

CLAIMS1. An image generating block (100, 200) for use in a digital signage, the image generating block comprising: an array of liquid crystal display (LCD) cells (102) covered by a glass (104) on a first side (102A) of the array of LCD cells; a backlight module (106, 306) having at least one array of light emitting diode (LED) printed circuit boards (PCBs) (310), wherein the backlight module is configured to illuminate a second side (102B) of the array of LCD cells, using the at least one array of LED PCBs; and an optical layer (108) arranged between the second side of the array of LCD cells and the backlight module, wherein the optical layer is configured to adjust an incident angle and a wavelength of the illumination from the backlight module, the optical layer comprising: a reflector foil (110) arranged adjacent to the backlight module, wherein the reflector foil is configured to provide a passage for the illumination from the backlight module to pass through the optical layer towards the array of LCD cells, a diffuser layer (112) configured to disperse the illumination from the backlight module within the optical layer, wherein the diffuser layer is separated from the reflector foil by means of at least one optical foil standoff (114) forming a first air gap (116) between the diffuser layer and the reflector foil, a polarization layer (118, 218) arranged adjacent to the diffuser layer, wherein the polarization layer is configured to manipulate the illumination dispersed by the diffuser layer into a predefined orientation, and an amplification foil (120) arranged in proximity to the polarization layer, wherein the amplification foil is configured to reflect a first part of the illumination straying away afterpolarization, back to the reflector foil, and guide a second part of the illumination towards the second side of the array of LCD cells.

2. An image generating block (100, 200) according to claim 1, wherein the array of LCD cells (102) is positioned at a distance (DI) from the optical layer (108) forming a second air gap (122) therebetween, wherein said distance is in a range from 1 to 6 millimeters (mm).

3. An image generating block (100, 200) according to claim 1 or 2, wherein each LED PCB amongst the at least one array of LED PCBs (310) comprises one or more LEDs (308) arranged thereon in a predefined pattern.

4. An image generating block (100, 200) according to claim 3, wherein the predefined pattern comprises each of the one or more LEDs (308) to be spaced apart from remaining of the one or more LEDs by a range of 10 to 50 mm.

5. An image generating block (100, 200) according to any of the preceding claims, wherein the reflector foil (110) comprises at least one hole corresponding to a position of one or more LEDs (308) arranged on the at least one array of LED PCB (310), to provide the passage for the illumination from the backlight module to pass therethrough.

6. An image generating block (100, 200) according to any of the preceding claims, wherein the reflector foil (110) is of a thickness ranging between 30 to 170 micrometers (pm).

7. An image generating block (100, 200) according to any of the preceding claims, wherein the reflector foil (110) is a multilayer polyester-based film.

8. An image generating block (100, 200) any of the preceding claims, wherein the reflector foil (110) has a third side (110A) facing away from the backlight module (106), wherein the third side of reflector foil is coated with a reflective material.

9. An image generating block (100, 200) according to any of the preceding claims, wherein the reflector foil (110) has a fourth side (HOB) attached to the backlight module (106) by means of at least one of: an adhesive, an additional fixing layer, at least one attachment.

10. An image generating block (100, 200) according to any of the preceding claims, wherein a protective film is applied to both of the third side (110A) and the fourth side (HOB) of the reflector foil (110).

11. An image generating block (100, 200) according to any of the preceding claims, wherein the diffuser layer (112) is positioned at a distance (D2) in a range from 10 to 50 mm, from the backlight module (106).

12. An image generating block (100, 200) according to any of the preceding claims, wherein the diffuser layer (112) is of a thickness in a range from 1 to 5 mm.

13. An image generating block (100, 200) according to any of the preceding claims, wherein the diffuser layer (112) is made of an opalescent material.

14. An image generating block (100, 200) according to any of the preceding claims, wherein the polarization layer (118, 218) comprises a first polarizer (118A, 218B) and a second polarizer (118B, 218B), wherein the first polarizer is oriented at a first polarizing angle relative to a plane of the diffuser layer and the second polarizer is oriented at a second polarizing angle relative to the plane of the diffuser layer, respectively.

15. An image generating block (100) according to any of the preceding claims, wherein the polarization layer (118, 218) is of a thickness in a range between 0.1 to 1 mm.

16. An image generating block (100) according to any of the preceding claims, wherein the amplification foil (120) has a fifth side (120A) and asixth side (120B), and wherein each of the fifth side and the sixth side is laminated with a diffused polycarbonate.

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