DESC:FIELD OF THE INVENTION
Embodiment of the present invention relates to magnetic fluid based display device used in head mounted devices, and more particularly to ferrofluid based displays that are capable of providing higher contrast and true black color in such head mounted devices.
BACKGROUND OF THE INVENTION
With widespread adoption of virtual/augmented reality (VR/AR) head mounted devices, high attention is being drawn towards reshaping optical components, particularly display technology in such devices to make them truly integral in everyday lives. While virtual reality devices can offer completely immersive environment blocking the ambient light, see-through displays are desired in augmented reality devices for viewing enriched virtual content overlaid on the real world.
Currently existing devices have made use of self-emitting light emitting diodes (e.g. organic light emitting diodes [OLEDs]) for augmented/virtual reality applications. However, they are accompanied with inherent disadvantage of high luminance requirement to obtain sharper image quality. Although this can be achieved by increasing the luminescent intensity, this brute force approach leads to a decrease in the lifetime of the materials and also higher energy consumption, which increasingly heats up the ar/vr devices.
Displaying deep or truly black color in optical see through head mounted displays is a major challenge due to the inability to maintain high contrast, particularly in bright outdoor environments. In natural sunlight or bright indoor lighting, the display often loses its color contrast, leading to virtual images appearing washed out or difficult to distinguish from the real-world surroundings. Thus, there is a need for refinement in the design of existing optical see-through head mounted displays to achieve better contrast ratios in common lighting conditions. Contrast ratio is typically determined from person’s ability to distinguish a visual stimulus based on the differences in luminance between it and its environment. Visual stimulus that falls outside a person’s contrast sensitivity function can be dealt with in two different manners, either by increasing the spatial frequency (e.g., its size), or by increasing the contrast.
However, in contemporary optical see-through devices, screen space is valuable due to the limited field of view on most devices. Because of this, increasing spatial frequency in reduced contrast situations only works so long as the image fits within the field of view of the device. With this upper bound on spatial frequency, any additional change to make imagery distinguishable to the user must come from adjusting either the contrast between the foreground and background color of the virtual imagery or the contrast between the foreground color of the virtual imagery with the user’s physical environment.
There are several factors that can cause a reduction in contrast with OST-HMDs, e.g., environmental factors like dynamic or saturated lighting conditions and see-through backgrounds. Tinted visors attached to see-through displays are often used as a practical solution to increase the contrast between virtual imagery by reducing the illuminance levels of the environment lighting. However, the tinting inevitably reduces the visibility of the real scenes in low lighting environments and prevents accurate color perception.
Further, traditional optical see through- head mounted devices (OST-HMDs) rely on light modulation techniques like liquid crystal or OLED panels, but they struggle to achieve true black. OLED displays can provide deep blacks, but in a transparent configuration, these displays still cannot fully block light in certain conditions, making it difficult to generate a consistent, true black background for virtual imagery. Furthermore, existing technologies may rely on multiple display layers, which can lead to bulky and less efficient designs. The need for a separate light source and complex components like diffusers and reflectors can increase the size, power consumption, and cost of the display system.
Many current systems suffer from reduced transparency when displaying virtual imagery. This limits the user’s ability to interact with their physical environment while also viewing virtual content. There is often a trade-off between display performance (brightness, color, contrast) and transparency, which is not ideal for an immersive, non-intrusive user experience. In addition, these systems do not dynamically adjust to various levels of ambient light. For instance, in some cases, the display’s light intensity is either too high or too low, and the system does not adapt well to fluctuating lighting conditions or varying user environments.
Even more, some systems use energy-intensive methods to achieve acceptable image quality, including high-powered backlights or complex image-processing systems. This can result in short battery life in head-mounted devices, a significant constraint for long-term use. To address such limitations of limited contrast, color accuracy, inability oto achieve true black, bulky design panel, limited optical transparency, static or non-adaptive light control, low efficiency and power consumption, researchers have faced immense challenge in presenting virtual content, specifically text information over OST-HMDs. They found that the legibility on display is highly affected by the text drawing style, the see-though background, and interaction of various elements on the display scene. This indicates the need for further refinement in the design of optical see-through displays to achieve better contrast ratios in common lighting conditions.
Thus, none of the above discussed configurations and combinations of various display devices is capable of presenting an energy-efficient OST HMD that can achieve true black, wide viewing angle, better response time, lower power consumption, higher contrast ratio, wider color gamut, better image quality with acute sharpness, clarity and brightness, reduced chromatic aberration; still having light weight and a small form factor with enhanced flexibility.
In order to the above issues, a thin and flexible see through display device designed with a unique combination of constituting elements has been attempted in present disclosure, and that may address one or more of the challenges or needs mentioned herein, as well as provide other benefits and advantages. In the background of foregoing limitations, there exists a need for light weight and high-performance display device that is not posed with aforementioned challenges and offers ease of wearability, scalability and affordability in order to contribute to immersive experiences of virtual world.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form prior art.
OBJECT OF THE INVENTION
An object of the present invention is to provide a low-cost, high-performance, portable and light weight optical see through display device that provides higher contrast and better illumination while displaying both real and virtual worlds.
Another object of the present invention is to provide a true, uniform display of high resolution and contrast using ferrofluid based display in head mounted device.
Yet another object of the present invention is to provide an effective display technology providing high brightness, low power consumption, high color gamut, high contrast and high dynamic contrast.
Yet another object of the present invention is to provide a ferro fluid based display that makes up for a light and better contrast providing device capable of displaying true black color.
Yet another object of the present invention is to provide light weight magnetic fluid based display that provide enhanced contrast sensitivity in any kind of lightning environment ranging from dynamic or saturated lighting conditions and see-through backgrounds.
In yet another embodiment, easy to wear and comfortable magnetic fluid based display that is capable of presenting virtual content in outdoor environments due to dynamic lightning conditions and uncontrollable backgrounds.
SUMMARY
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.
In accordance with first aspect of the disclosure, a head mounted display characterized in utilizing ferrofluid layer is disclosed. The system comprising of an image source; a first display panel comprising a waveguide that is optically coupled to the image source configured to emit a display image. The system further comprising a second display panel comprising a ferrofluid layer sandwiched between a front and rear transparent substrate; and a controller configured to receive the display image and generate a context-aware pixel-wise magnetic field across the second display panel, thereby aligning or dispersing the ferrofluid layer to modulate transmission or blocking of ambient light through corresponding pixel regions. Significantly, here the second display panel is operative to render a true black appearance at pixel locations determined to be below a brightness threshold in the display image.

In accordance with second aspect of the disclosure, a method for rendering black in a head mounted display is disclosed, wherein the method comprising steps of: receiving a display image from an image source; analysing and pre-processing, by a controller, the display image to normalize and extract features therefrom; segmenting the display image into one or more regions for modulation-identifying high-contrast edges, uniform edges, and soft gradients for differentiated treatment; dynamically adjusting brightness threshold, by the controller based on a plurality of parameters; comparing brightness value, by the controller, of the segmented display image against the brightness threshold; generating a context-aware pixel-wise magnetic field to modulate the segmented display image based on the compared brightness value; and rendering a true black appearance, on a head mounted display, at pixel locations determined to be below the brightness threshold in the display image.

BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular to the description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, the invention may admit to other equally effective embodiments.
These and other features, benefits and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:
Fig. 1 illustrates OST-HMD, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims. As used throughout this description, the word "may" be used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense, (i.e., meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles, and the like are included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.
Reference will now be made to embodiments, examples of which are illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide an understanding of the various described embodiments. However, it will be apparent to one of ordinary skill in the art that the various described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition, element or group of elements with transitional phrases “consisting of”, “consisting”, “selected from the group of consisting of, “including”, or “is” preceding the recitation of the composition, element or group of elements and vice versa.
The present invention is described hereinafter by various embodiments with reference to the accompanying drawings, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description.
This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.
The present disclosure presents a see-through, mixed reality display device that enables a user to observe digital information overlaid on the physical scenery. Referring to Fig. 1, in case of optical see-through head mounted device (OST-HMD) where the user is required to see through the real world, rendering truly dark/deep black color virtual information is a major challenge. Current optical see-through displays have limited ability in display of color with low lightness such as black that have low lightness in the hue, saturation, lightness (HSL) color space. These colours cannot be rendered by adding light into the scene. These colours appear transparent on an OST-HMD, effectively not being rendered at all.
A known problem with this type of display method is that when the user is in particularly bright environments, such as outdoors during the day, then the virtual imagery on the display tends to lose contrast in relation to the environment. Thus, with known configurations there are errors in display of virtual image as suboptimal black color is obtained in common lightning conditions.
To overcome above limitation, the present disclosure proposes a novel design and methodology for achieving true black and enhanced image contrast in optical see-through head-mounted displays (OST-HMDs). The design of present disclosure incorporates an advanced multi-panel optical configuration with an integrated ferrofluid-based light-blocking system. A self-luminous micro-display paired with a waveguide-based optical system and a ferrofluid layer controlled via magnetic fields enables unprecedented contrast performance, particularly under high ambient lighting conditions. Thus, the system of present disclosure, resolves existing limitations by using ferrofluid technology integrated with a transparent panel system and precision-controlled magnetic fields, as explained in greater detail below.
Referring now to Fig. 1, an OST-HMD display 1000 of present disclosure is illustrated that typically comprises of an image source 100 and at least a first display panel and a second display panel that are at least partly transparent, to provide a substantially unobstructed field of view in which the user can directly observe his real physical surroundings. The image source 100 is configured to direct the illuminated light to form a colored display image. In one example embodiment, the image source 100 may be a micro-OLED display that forms a colored display image or may be a reflective liquid-crystal-on-silicon (LCOS) or digital micromirror display (DMD) device. The OST-HMD 1000 further comprises of a controller 500 to provide suitable control signals that, when received by the image source 100 causes the desired display image to be formed. The controller 500 further manages image rendering and magnetic field generation for ferrofluid pixel control, as will be explained later.
In one ideal configuration, for purposes of forming compact OST-HMD 1000 and to avoid obstructing user’s view of external imagery, the image source 100 is shown offset from user’s field of view. Since the micro OLED panel 100 is self-luminous, a separate light source is not required, and the transmissive OST-HMD 1000 can be configured more simply and compactly.
Next, re-referring to Fig. 1, the OST-HMD 1000 comprises of at least two panels that may be curved or planar (or portions thereof may be planar). While these layers may be depicted rectangular, however they may acquire other shapes based on shape of head mounted device or visor. Broadly, in one significant embodiment the OST-HMD 1000 comprises of a first layer 200 including a transparent waveguide 210 which is positioned closer to user eye and configured to receive the display image and to shift the display image into the user’s field of view.
The waveguide 210 may be substantially transparent to external imagery received normal to its front surface receiving the display image. Thus, the waveguide 210 may be positioned in front of the eye of the HMD-device user without obstructing the user’s view of the external imagery. Apropos, the light from the display image propagates through the waveguide by reflection from the front and back surfaces of the waveguide 210. In the illustrated embodiment, the direction of propagation is from the temple side—i.e., the end portion of the waveguide closest to the user’s ear—to the opposite end portion, which is oriented toward the bridge of the user’s nose. The transparent waveguide 210 is responsible for image redirection via Total Internal Reflection (TIR).
In one exemplary embodiment, a collimator lens 150 may be provided to collimate and reflect the light from the image source 100 into the first of the series of transparent sections of the waveguide 210. Ideally, each ray of display light directed from the collimator 150 will encounter front surface of the waveguide 210 above the Snell's Law critical angle and propagate through the transparent section by total internal reflection (TIR). Additionally, the waveguide 210 may be encompassing a beam splitter or an out-coupling structure 250 to split the received ray into a plurality of parallel light rays distributed along the direction of propagation in the waveguide 210 and leave the back surface of the waveguide 210 with an expanded exit pupil and evenly distributed image light.
Thence, use of a micro-OLED image source 100 combined with transparent waveguides 210 allows for a compact design without sacrificing transparency. The absence of a separate backlight source further reduces the bulk and energy requirements. The above waveguide configuration 210 is complemented with an additional panel that forms a second layer 300 comprising of a transparent front 310 and rear substrate 320 holding therebetween a layer of suspended particles 350, precisely of ferrofluid that are capable of responding to applied magnetic field. The two transparent glass substrates 310, 320 defines a space therebetween to hold the opaque ferrofluid 350 that responds to magnetic field that may be applied using magnetic field generator having large field gradient. With the requisite of magnitude of applied magnetic field, as controlled by the controller 500, the ferrofluid droplets 350 may be directed to move to regions of display that requires to be displayed in absolute black.
Notably, ferrofluid 350 is essentially a colloidal suspension wherein magnetic particles (typically magnetite) of submicron size remains suspended in a non-magnetic, transparent and immiscible carrier fluid such as water, hydrocarbons, fluorocarbons, esters, diesters and the like to exhibit strong magnetic characteristics. A totally non-transparent black liquid, the ferrofluid 350 typically comprising of magnetite particles coated with dispersing agent like oleic acid forms a spherical droplet that can be moved or translated in response to applied magnetic field.
In continuation to present disclosure, the two transparent glass substrates 310, 320 sandwiching the ferrofluid 350 in a stable state, are formed of conductive layer that generates a magnetic field in response to image data of each pixel in order to orient the ferrofluid 350. In the above technical arrangement, the magnetic particles in the ferrofluid 350 may be selected from ferrite, ferric oxide, nickel, molybdenum disulfide, and others. The magnetic particles are as small as possible to be dispersed uniformly and suspended constantly, preferably 0.001 to 10 micrometers in the diameter. In general, the particles remain randomly suspended, creating an opaque black layer due to strong light absorption and scattering and when the magnetic field is applied, the particles align along the magnetic field lines, forming transparent channels that allow light to pass through between aligned particle chains.
The distance in the space between the two transparent panels 310, 320 may be equal to a row of at least some of the magnetic particles and more preferably, is tens to hundreds times greater than the diameter of the magnetic particle (generally, several to hundreds micrometers) to ensure the opaqueness of the ferrofluid 350 in the suspended state. In one working embodiment, the controller 500 of OST-HMD 1000 is configured to selectively generate the magnetic field in response to an image control signal of each pixel of the ferrofluid 350. For example, the magnetic field is produced by energizing a pattern electrode or solenoid coil for the pixel with a given magnetizing current or directly by applicable magnetizing means.
In the given arrangement, the ferrofluid 350 remains opaque with the magnetic particles being uniformly suspended in the stable dispersed state, when the magnetic field relative to a corresponding pixel is not generated by the controller 500 due to the attribute of an image control signal. As the result, the transmission of light is interrupted at the pixel by the uniformly dispersed state of the magnetic particles in ferrofluid. When the solenoid coil of the pixel is energized with a magnetizing current of the controller 500 in response to an image control signal, it produces the magnetic field. As the action of the magnetic field causes the magnetic particles in the ferrofluid 350 to align in straight rows, the light is not completely blocked by but passed between the rows of the magnetic particle in the pixel. Thence, based on image to be displayed before the user eye, the controller 500 signals transmission or blocking of light by the magnetic particles suspended in the glass substrates forming the second panel 300.
Thus, without a magnetic field, ferrofluid particles are randomly oriented and dispersed, causing the layer to absorb or scatter incoming light, thus appearing black or opaque to the user. While, when the magnetic field is applied, particles form linear chains or rods along the applied field direction. This structural transition reduces scattering and absorption, making the layer more transparent and allowing light from the image source 100 to reach the user’s eye. As explained later, the degree of alignment is tuned by the controller 500 using pulse width modulation to achieve optimal contrast and clarity to changing image content/outside lightning conditions.
In one exemplary embodiment, a method of achieving true black color in an OST-HMD 1000 is explained. Accordingly, at first the state of each pixel of the display panel is obtained based on received image/video data. Such a state may be a colored or a dark state that is obtained by capturing brightness value of each pixel in the display panel according to the input image data, which is an RGB image data. This brightness state is measured against the brightness threshold value and determining that the pixel is in a bright state when the brightness value of the pixel is greater than or equal to the threshold brightness; and under the condition that the brightness value of the pixel is smaller than the threshold brightness, determining that the pixel is in a dark state.
In one working embodiment, the solenoid coils or patterned electrodes behind ferrofluid pixels are energized, and the generated magnetic field causes ferrofluid particles to align and block light. It should be noted that the display regions and the image signal are in one-to-one correspondence, specifically, along a direction perpendicular to the display panel. This enables generating a controlled signal to fill the region on display panel with adequate colours. In an event dark color is desired, the ferrofluid 350 is activated to block the passage of light there through to generate complete and true dark color.
Briefly, the incoming image data (RGB values) from image source 100 is analysed in real-time by a controller 500. Now, if the pixel’s brightness is below threshold, it is categorized as a black pixel, and if the pixel’s brightness is above threshold, it is categorized as a color pixel by the controller 500. Each pixel’s brightness level is evaluated against a threshold value to determine if it should appear as bright or dark (black). For the black pixels, the controller 500 disables the magnetic field at corresponding pixels, leaving ferrofluid particles in a suspended, randomized state—thus blocking light. While, for bright pixels, the controller 500 activates the magnetic field, aligning the particles 350 and allowing light from the image source 100 to pass through clearly.
In next working embodiment, the controller 500 utilizes artificial intelligence for controlling ferrofluids and dynamic context-aware light modulation in the display system by enabling real-time, adaptive, and intelligent management of the magnetic field applied to the ferrofluid. At first, the controller 500 analyses the incoming image data and provide precise control over each pixel’s brightness level. In one working embodiment, the controller 500 utilizes convolutional neural networks (CNNs) to process the image in real time to assess the pixel’s brightness and decide whether it needs to be bright or dark (black). The incoming image data is analysed and segmented into regions (e.g. edges, gradients, textures, backgrounds) relevant for modulation-identifying high-contrast edges, uniform edges, and soft gradients for differentiated treatment. This ensures that the ferrofluid layer 350 is modulated accurately for high contrast and image clarity, reducing latency and improving the quality of dynamic light modulation. In accordance with one working embodiment, the image features may be extracted such as edges (using any learned filters), texture, and local contrast.
Next, in order to ensure optimal thresholding for determining which pixels should be black or bright, the controller 500 employs like reinforcement learning or adaptive thresholding algorithms to dynamically adjust the brightness threshold based on various factors (ambient lighting, display conditions, user preferences, etc.). This will make the system highly adaptable to changing environmental conditions, improving the performance of the display under diverse lighting situations. The reinforcement learning (RL) based framework allows to iteratively experiments with different threshold values, instead of using fixed threshold in response to changes in image content, environmental lightning or may be user feedback.
For example, if the chosen threshold results in high-contrast, visually clear images, the controller 500 receives a positive reward and is more likely to select similar thresholds in future. If the output is suboptimal, the controller 500 updates itself to explore alternative thresholds. Now, for each pixel, the controller 500 instructs to generate a specific magnetic field strength and pattern. If a pixel should be black, the magnetic field is disabled or set so that ferrofluid nanoparticles remain in randomized, dispersed state, scattering or absorbing light and blocking transmission. If a pixel should be bright, the magnetic field is activated, the ferrofluid nanoparticles are activated and aligned into chains or structures along the field lines, which become optically transparent and allow light to pass through.
The controller 500 thus adjusts light modulation based on context, such as the content being displayed (e.g., high contrast images vs. gradients) as the controller 500 can detect patterns and optimize the magnetic field to match the type of content being shown. For example, it can apply stronger modulation or sharp edges and gentler modulation for gradients, ensuring the display adapts in real time to the visual requirement of each scene. This enables more natural and visually appealing images, as the ferrofluid’s response is tailored to the visual content being displayed.
In one working embodiment, the controller 500 apply as sharper, binary magnetic filed control to ferrofluid particles 350, ensuring crisp black/bright transitions and maximizing contrasts. While for gradients or soft transitions, the controller 500 utilizes pulse-width modulation (PWM) to create intermediate states in the ferrofluid, allowing partial light transmission and smooth visual gradients. Thus, the degree of alignment and hence the opacity or transparency is finely tuned using PWM to vary the magnetic field strength. This enables not just binary (on/off) control, but also intermediate levels for smooth gradients or partial transparency. The controller 500, significantly, continuously monitors the display output and environmental factors, for adjusting the magnetic field at each pixel in real time. This ensures optimal contrast, clarity, and responsiveness to changing image content or ambient lightning.
Thus, the image generated by the micro-OLED 100 is projected into the waveguide 210. A beam-splitting or out-coupling structure 250 (e.g., diffractive gratings) redirects light toward the user's eye. Simultaneously, the ferrofluid layer 350 modulates which parts of this image are allowed to pass through with high contrast and which parts are blocked to render black. The controller 500 thus pre-processes the received image and normalize the brightness, denoise it and enhance the features for extraction. The image is segmented into regions of interest, which are then classified as either edges, gradient or background.
This is followed by assigning adaptive thresholds per region, wherein each pixel is mapped to a magnetic field strength. For each pixel, the controller 500 set the magnetic filed to be applied accordingly, while for gradients, the field strength is interpolated for smooth transitions. Thus, by utilizing a ferrofluid-based panel that responds to an applied magnetic field, the proposed system can selectively block light in specific regions to generate true black. The transparent substrates of the panel are conductive and insulated, and the ferrofluid 350 is sealed hermetically for stable performance over time. This feature allows for a more accurate and effective representation of dark colors, especially in high-contrast scenes. The system's ability to manipulate the ferrofluid 350 to block light at specific pixels helps to maintain high contrast and clarity even in bright settings. The resulting imagery will retain its vibrancy, offering users a more engaging and visible experience in a range of lighting conditions.
The magnetic field-based control of the ferrofluid allows for dynamic image adjustment. The system can adapt in real time to the image data, improving both visual output and user experience, regardless of environmental factors like ambient light. By utilizing the magnetic manipulation of the ferrofluid and the self-luminous micro-OLED panel, the technology reduces power consumption. The ability to dynamically adjust the display image also means that unnecessary energy usage can be minimized. Eventually, the improved contrast and true black color reproduction, combined with the transparent design of the system, ensure that the user remains fully immersed in the virtual environment without losing sight of the real world.
In accordance with an embodiment, the head mounted device comprises a memory unit configured to store machine-readable instructions. The machine-readable instructions may be loaded into the memory unit from a non-transitory machine-readable medium, such as, but not limited to, CD-ROMs, DVD-ROMs and Flash Drives. Alternately, the machine-readable instructions may be loaded in a form of a computer software program into the memory unit. The memory unit in that manner may be selected from a group comprising EPROM, EEPROM and Flash memory. Further, a processor is operably connected with the memory unit. In various embodiments, the processor is one of, but not limited to, a general-purpose processor, an application specific integrated circuit (ASIC) and a field-programmable gate array (FPGA).
In general, the word “module,” as used herein, refers to logic embodied in hardware or firmware, or to a collection of software instructions, written in a programming language, such as, for example, Java, C, or assembly. One or more software instructions in the modules may be embedded in firmware, such as an EPROM. It will be appreciated that modules may comprised connected logic units, such as gates and flip-flops, and may comprise programmable units, such as programmable gate arrays or processors. The modules described herein may be implemented as either software and/or hardware modules and may be stored in any type of computer-readable medium or other computer storage device.
Further, while one or more operations have been described as being performed by or otherwise related to certain modules, devices or entities, the operations may be performed by or otherwise related to any module, device or entity. As such, any function or operation that has been described as being performed by a module could alternatively be performed by a different server, by the cloud computing platform, or a combination thereof. It should be understood that the techniques of the present disclosure might be implemented using a variety of technologies. For example, the methods described herein may be implemented by a series of computer executable instructions residing on a suitable computer readable medium. Suitable computer readable media may include volatile (e.g., RAM) and/or non-volatile (e.g., ROM, disk) memory, carrier waves and transmission media. Exemplary carrier waves may take the form of electrical, electromagnetic or optical signals conveying digital data steams along a local network or a publicly accessible network such as the Internet. It should also be understood that, unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as "controlling" or "obtaining" or "computing" or "storing" or "receiving" or "determining" or the like, refer to the action and processes of a computer system, or similar electronic computing device, that processes and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope of consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention.
,CLAIMS:We Claim:
1) A head mounted display (1000), characterized in utilizing ferrofluid layer (350), comprising:
an image source (100);
a first display panel (200) comprising a waveguide (210) optically coupled to the image source (100) configured to emit a display image;
a second display panel (300) comprising a ferrofluid layer (350) sandwiched between a front (310) and rear transparent substrate (320); and
a controller (500) configured to receive the display image and generate a context-aware pixel-wise magnetic field across the second display panel (300), thereby aligning or dispersing the ferrofluid layer (350) to modulate transmission or blocking of ambient light through corresponding pixel regions;
wherein the second display panel (300) is operative to render a true black appearance at pixel locations determined to be below a brightness threshold in the display image.

2) The head mounted display (1000), as claimed in claim 1, wherein the image source (100) is a micro-OLED display, a reflective liquid-crystal-on-silicon (LCOS) or a digital micromirror display device.

3) The head mounted display (1000), as claimed in claim 2, wherein the image source (100) is positioned offset from user’s field of view.

4) The head mounted display (1000), as claimed in claim 1, further comprising a collimator (150) positioned between the image source (100) and the waveguide (210) to direct collimated light into the waveguide (210) at an angle above a Snell’s Law critical angle for total internal reflection.
5) The head mounted display (1000), as claimed in claim 4, further comprising an out-coupling structure (250) disposed within the waveguide (210) to split the collimated light into multiple parallel rays along a direction of propagation toward a user's eye, thereby expanding the exit pupil of the display image.

6) The head mounted display (1000), as claimed in claim 1, wherein the ferrofluid layer (350) comprises magnetite (Fe3O4) particles coated with a dispersing agent selected from oleic acid, surfactants, or similar stabilizers, and suspended in a carrier fluid selected from hydrocarbons, esters, fluorocarbons, or water.

7) The head mounted display (1000), as claimed in claim 1, further comprising patterned electrodes or solenoid coils embedded within or adjacent to the front (310) and rear transparent substrate (320) for generating the magnetic field.

8) The head mounted display (1000), as claimed in claim 1, wherein the controller (500) is further configured to compute a brightness value for each pixel of the input image, compare the brightness to the brightness threshold, and activate the ferrofluid layer (350) to block light in regions below the brightness threshold to create a dark appearance.

9) The head mounted display (1000), as claimed in claim 1, wherein the controller (500) is further configured to tune degree of alignment of the ferrofluid layer (350) using pulse width modulation to achieve optimal contrast and clarity.

10) The head mounted display (1000), as claimed in claim 1, wherein the controller (500) is configured to determine that the pixel is in a bright state in an event brightness value of the pixel is greater than or equal to the brightness threshold, and the pixel is in a dark state in an event the brightness value of the pixel if lower than the brightness threshold.

11) The head mounted display (1000), as claimed in claim 10, wherein the controller (500) is configured to generate the context-aware pixel-wise magnetic field across the second display panel (300) in steps of:
analysing and pre-processing the display image to normalize and extract features;
segmenting the display image into one or more regions for modulation-identifying high-contrast edges, uniform edges, and soft gradients for differentiated treatment;
dynamically adjusting the brightness threshold based on a plurality of parameters; and
generating the context-aware pixel-wise magnetic field to modulate the segmented display image using the dynamically adjusted brightness threshold.

12) The head mounted display (1000), as claimed in 11, wherein the brightness threshold is adjusted based on the plurality of parameters consisting image content, environmental lightning or user feedback or a combination thereof.

13) The head mounted display (1000), as claimed in claim 11, wherein the controller (500) is configured to utilize convolutional neural networks (CNNs) to process the display image in real time to assess the pixel’s brightness values.

14) The head mounted display (1000), as claimed in claim 11, wherein the brightness threshold is dynamically adjusted using reinforcement learning or adaptive thresholding algorithms.

15) A method for rendering black in a head mounted display (1000), comprising steps of:
receiving a display image from an image source (100);
analysing and pre-processing, by a controller (500), the display image to normalize and extract features therefrom;
segmenting the display image into one or more regions, by the controller (500) for modulation-identifying high-contrast edges, uniform edges, and soft gradients for differentiated treatment;
dynamically adjusting brightness threshold, by the controller (500) based on a plurality of parameters;
comparing brightness value, by the controller (500), of the segmented display image against the brightness threshold;
generating a context-aware pixel-wise magnetic field to modulate the segmented display image based on the compared brightness value; and
rendering a true black appearance, on a head mounted display (1000), at pixel locations determined to be below the brightness threshold in the display image.

16) The method, as claimed in claim 15, wherein the brightness threshold is adjusted based on the plurality of parameters consisting image content, environmental lightning or user feedback or a combination thereof.

17) The method, as claimed in claim 15, further comprising utilizing convolutional neural networks (CNNs) to process the display image in real time to assess the pixel’s brightness values.
18) The method, as claimed in claim 15, wherein the brightness threshold is dynamically adjusted using reinforcement learning or adaptive thresholding algorithms.

19) The method, as claimed in claim 15, wherein the context-aware magnetic field to modulate the segmented display image by way of tuning degree of alignment of a ferrofluid layer (350) of the head mounted display (1000) using pulse width modulation.

20) The method, as claimed in claim 15, wherein a pixel of the display image is in a bright state in an event brightness value of the pixel is greater than or equal to the brightness threshold, and the pixel is in a dark state in an event the brightness value of the pixel if lower than the brightness threshold.