Description:SYSTEM AND METHOD FOR CONTROLLING A BACKLIGHT SYSTEM OF A DISPLAY

BACKGROUND

TECHNICAL FIELD
[0001] The present invention relates to backlight architectures for display systems. More particularly, the present invention relates to a system and method for controlling a backlight system of a display using a plurality of light-emitting diodes (LEDs).

DESCRIPTION OF THE RELATED ART
[0002] Display systems used in avionics, defense, and other mission-critical applications are required to operate across a wide range of illumination conditions, including high-brightness daytime environments and low-luminance conditions compatible with night vision goggles (NVG). Such systems are required to meet stringent requirements relating to luminance uniformity, spectral characteristics, and controlled light output while ensuring reliable performance across different operating conditions.
[0003] Conventional backlight implementations typically employ separate sets of light-emitting diodes (LEDs) for day mode and NVG-compatible night mode. These LEDs are often arranged on different printed circuit boards (PCBs) or implemented as separate backlight assemblies. Such implementations result in increased component count, duplication of circuitry, and inefficient utilization of available PCB space.
[0004] Further, the use of separate LED arrangements for different modes introduces challenges in maintaining consistent illumination across the display. Differences in the spatial distribution of LEDs and variations in light propagation between day and NVG configurations may result in non-uniform brightness, visible artifacts, and inconsistencies in display performance, particularly during transitions between operating conditions or modes.
[0005] In addition, existing backlight systems provide limited capability for coordinated control of illumination levels corresponding to different operating modes. In many implementations, luminance control is applied independently for each mode without ensuring perceptual consistency between modes, which may result in noticeable variations in brightness when switching between day and night conditions.
[0006] Moreover, ensuring proper control between day LEDs and NVG-compatible LEDs remains a challenge in existing systems. Improper activation or lack of coordinated control may lead to spectral interference, reduced NVG compatibility, and degraded operational reliability.
[0007] Accordingly, there exists a need for an improved backlight system that enables dual-mode operation using a unified arrangement of LEDs on a single PCB, maintains consistent illumination characteristics across operating modes, and provides coordinated control of luminance while ensuring reliable operation between different lighting conditions.

BRIEF SUMMARY
[0008] One or more embodiments relate to a system and method for controlling a backlight system for display devices that are required to operate effectively in both high ambient illumination conditions and low ambient illumination conditions, including conditions involving the use of night vision goggles (NVG). The system utilizes a single circuit board that accommodates different types of light sources for multiple operating conditions or modes. These light sources are arranged in an alternating manner to enable efficient use of space and uniform illumination across the display. A control mechanism determines an operational mode based on operational factors such as ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day. Based on the determined operational mode, activation of the light sources is controlled such that one type of light source is activated at a given time. Additionally, the brightness of the activated light sources is regulated to maintain consistent and suitable illumination levels.
[0009] Overall, the present disclosure provides a compact and efficient backlight solution capable of delivering consistent display performance across different operating conditions while ensuring controlled and reliable illumination.
[0010] An embodiment of the present disclosure relates to a system for controlling a backlight system of a display. In an embodiment, the backlight system is configured for at least one of a direct lighting configuration, in which the LEDs are arranged behind a display panel, and an edge lighting configuration, in which the LEDs are arranged along the edges of a light guide to couple light into the light guide, thereby enabling compatibility with multiple display architectures.
[0011] In an embodiment, the system comprises a printed circuit board (PCB) having a plurality of day light-emitting diodes (LEDs) and a plurality of night vision goggle (NVG)-compatible LEDs disposed thereon. The plurality of day LEDs and the plurality of NVG-compatible LEDs are arranged on the PCB in an alternating pattern such that each of the plurality of day LEDs is spatially interleaved with at least one of the plurality of NVG-compatible LEDs, thereby enabling uniform spatial distribution of illumination sources. In an embodiment, the alternating pattern comprises a row-wise interleaved arrangement.
[0012] In an embodiment, the system comprises a determination module configured to determine an operational mode based on operation factors, such as ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day, wherein the operational mode comprises one of a day mode and a night mode.
[0013] In an embodiment, activation of the plurality of day LEDs and the plurality of NVG-compatible LEDs is controlled in accordance with the operational mode such that only one of the plurality of day LEDs and the plurality of NVG-compatible LEDs is activated at a given time.
[0014] In an embodiment, the system includes a luminance control module configured to control luminance of the activated LEDs based on the operational mode using a drive current and a pulse-width modulation signal. The luminance control module may coordinate the drive current and pulse-width modulation to maintain perceptual consistency between operating modes, and may vary the drive current to achieve a desired luminance level.
[0015] An embodiment of the present disclosure relates to a method for controlling a backlight system of a display. The method comprises providing a printed circuit board (PCB) having a plurality of day light-emitting diodes (LEDs) and a plurality of night vision goggle (NVG)-compatible LEDs arranged in an alternating pattern such that each of the plurality of day LEDs is spatially interleaved with at least one of the plurality of NVG-compatible LEDs.
[0016] In an embodiment, the method comprises determining an operational mode based on at least one of ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day, wherein the operational mode comprises one of a day mode and a night mode.
[0017] In an embodiment, the method comprises controlling activation of the plurality of day LEDs and the plurality of NVG-compatible LEDs in accordance with the operational mode such that only one of the plurality of day LEDs and the plurality of NVG-compatible LEDs is activated at a given time.
[0018] In an embodiment, the method further comprises controlling luminance of the activated LEDs based on the operational mode using at least one of a drive current and a pulse-width modulation signal, thereby enabling controlled brightness and consistent illumination across different operating conditions.
[0019] The features and advantages of the subject matter here will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying FIGUREs. As will be realized, the subject matter disclosed is capable of modifications in various respects, all without departing from the scope of the subject matter. Accordingly, the drawings and the description are to be regarded as illustrative in nature.

BRIEF DESCRIPTION OF THE DRAWING
[0020] In the FIGURES, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description applies to any one of the similar components having the same first reference label, irrespective of the second reference label.
[0021] FIGURE 1 illustrates an exemplary printed circuit board (PCB) configured to support a backlight arrangement for a display, in accordance with an embodiment of the present disclosure.
[0022] FIGURE 2 illustrates a system for controlling a backlight system of a display, in accordance with an embodiment of the present disclosure.
[0023] FIGURE 3 illustrates a flowchart of a method for controlling a backlight system of a display in accordance with an embodiment of the present disclosure.
[0024] Other features of embodiments of the present disclosure will be apparent from accompanying drawings and detailed description that follows. 
DETAILED DESCRIPTION
[0025] Terminology
[0026] Brief definitions of terms used throughout this application are given below.
[0027] The terms “connected” or “coupled” and related terms are used in an operational sense and are not necessarily limited to a direct connection or coupling. Thus, for example, two devices may be coupled directly, or via one or more intermediary media or devices. As another example, devices may be coupled in such a way that information can be passed there between them, while not sharing any physical connection with one another. Based on the disclosure provided herein, one of ordinary skill in the art will appreciate a variety of ways in which connection or coupling exists in accordance with the aforementioned definition.
[0028] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0029] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context dictates otherwise.
[0030] The phrases “in an embodiment,” “according to one embodiment,” and the like generally mean the particular feature, structure, or characteristic following the phrase is included in at least one embodiment of the present disclosure and may be included in more than one embodiment of the present disclosure. Importantly, such phrases do not necessarily refer to the same embodiment.
[0031] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).
[0032] Certain exemplary embodiments of the present invention are described below and illustrated in the accompanying FIGURES. The embodiments described are only for purposes of illustrating the present invention and should not be interpreted as limiting the scope of the invention, which, of course, is limited only by the claims below. Other embodiments of the invention and certain modifications and improvements of the embodiments described will occur to those skilled in the art, and all such alternate embodiments, modifications, and improvements are within the scope of the present invention.
[0033] According to common practice, the various features of the drawings discussed below are not necessarily drawn to scale. Dimensions of various features and elements in the drawings may be expanded or reduced to more clearly illustrate the embodiments of the invention.
[0034] FIGURE 1 illustrates an exemplary printed circuit board (PCB) 100 configured to support a backlight arrangement for a display, in accordance with an embodiment of the present disclosure.
[0035] In an embodiment, the PCB 100 comprises a plurality of day light-emitting diodes (LEDs) 102 and a plurality of night vision goggle (NVG)-compatible LEDs 104 disposed thereon. The PCB 100 serves as a common substrate for accommodating both the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 within a single layout, thereby enabling efficient utilization of available space for multiple illumination conditions.
[0036] In an embodiment, the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 are arranged on the PCB 100 in an alternating pattern such that each of the plurality of day LEDs 102 is spatially interleaved with at least one of the plurality of NVG-compatible LEDs 104. As illustrated in FIGURE 1, the alternating pattern may comprise a linear arrangement along a longitudinal axis of the PCB 100, wherein the LEDs are disposed in a sequential interleaved manner, thereby enabling substantially uniform spatial distribution of illumination sources across the PCB 100.
[0037] In an embodiment, the alternating arrangement may further comprise a row-wise interleaved configuration, wherein the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 are disposed in alternating positions along a row. In another embodiment, the arrangement may be extended to multiple rows, columns, or a matrix configuration while preserving the alternating interleaved relationship between the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104, thereby supporting uniform illumination across different regions of the display.
[0038] In an embodiment, spacing between adjacent LEDs on the PCB 100 is maintained substantially uniform to ensure consistent optical distribution. The interleaved placement of the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 enables similar geometric distribution characteristics for both types of LEDs, thereby facilitating uniform illumination when either of the plurality of day LEDs 102 or the plurality of NVG-compatible LEDs 104 is activated.
[0039] In an embodiment, the PCB 100 may further comprise conductive traces, pads, and routing paths configured to electrically couple the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 to corresponding driver circuitry. The routing may be configured to support controlled activation of the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 in accordance with an operational mode while maintaining electrical isolation between the two sets of LEDs.
[0040] In an embodiment, the PCB 100 may be configured in a form factor suitable for at least one of a direct lighting configuration and an edge lighting configuration. In a direct lighting configuration, the PCB 100 is arranged behind a display panel, whereas in an edge lighting configuration, the PCB 100 is arranged along an edge of a light guide. The linear arrangement illustrated in FIGURE 1 is particularly suited for edge lighting applications, although the alternating pattern is equally applicable to other configurations.
[0041] In an embodiment, the dimensions of the PCB 100, including length and width as illustrated in FIGURE 1, may be selected based on application-specific requirements. The spacing and placement of the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 may be optimized to achieve desired illumination characteristics while maintaining the alternating interleaved arrangement.
[0042] FIGURE 2 illustrates a system 200 for controlling a backlight system of a display, in accordance with an embodiment of the present disclosure. In an embodiment, the system 200 comprises a printed circuit board (PCB) 100 having a plurality of day light-emitting diodes (LEDs) 102 and a plurality of night vision goggle (NVG)-compatible LEDs 104 disposed thereon, along with processing and control components including a processor, a memory, a data storage unit, a determination module 202, and a luminance control module 204. The system 200 is configured to determine an operational mode and accordingly control activation and luminance of LEDs disposed on the PCB 100.
[0043] In an embodiment, the processor may comprise one or more processing units including a microcontroller, microprocessor, digital signal processor, or equivalent control circuitry. The processor may execute instructions stored in the memory and/or the data storage unit to perform the determination of operational mode and to generate control signals for activation and luminance control of LEDs. In an embodiment, the processor may operate in conjunction with dedicated driver circuitry to regulate current supplied to the LEDs.
[0044] In an embodiment, the memory may include volatile and non-volatile memory elements for storing executable instructions, configuration parameters, predefined thresholds, calibration data, and luminance control profiles corresponding to different operating conditions. The data storage unit may store historical data, mapping relationships between drive current and PWM duty cycle, and perceptual calibration parameters used for maintaining consistent illumination output across operational modes.
[0045] In an embodiment, the system 200 may further comprise one or more input interfaces configured to receive signals corresponding to ambient light conditions, user-defined inputs, system-defined configuration parameters, and timing information. In an embodiment, ambient light conditions may be detected using one or more light sensors operatively coupled with the system 200, and corresponding sensor signals may be provided to the determination module 202. In another embodiment, user-defined inputs may be received through a user interface such as a switch, control panel, or software interface.
[0046] In an embodiment, the determination module 202 may be configured to determine an operational mode of the backlight system based on one or more operational parameters (or factors) 206. The operational mode comprises one of a day mode and a night mode. The determination module 202 may process the one or more operational parameters 206 corresponding to ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day to determine the operational mode. In an embodiment, the determination module 202 may continuously monitor the operational parameters 206 or may perform a determination at predefined intervals, thereby enabling dynamic adaptation of the operational mode in response to changing environmental or operational conditions.
[0047] In an embodiment, ambient light conditions may be represented by an illumination level measured by one or more light sensors. The determination module 202 may receive sensor signals corresponding to ambient illumination and may perform signal conditioning, filtering, or averaging to obtain a stable illumination value. The determination module 202 may compare the measured illumination level with one or more predefined threshold values to classify the operating condition corresponding to the day mode or the night mode. In another embodiment, hysteresis may be applied to the threshold values to prevent frequent switching between modes under fluctuating lighting conditions.
[0048] In an embodiment, an example corresponding to the day mode may be considered. For instance, when the system 200 is deployed in a cockpit display or an outdoor display panel during bright daytime conditions, the one or more light sensors may detect a high ambient illumination level exceeding a predefined threshold. Based on such detection, the determination module 202 may classify the operating condition as corresponding to the day mode. In such a situation, the control signal generated by the determination module 202 may indicate selection of the day mode, and consequently, the luminance control module 204 may activate the plurality of day LEDs 102 while maintaining the plurality of NVG-compatible LEDs 104 in a deactivated state. Further, the luminance control module 204 may increase at least one of the drive current and the PWM duty cycle to achieve a higher luminance output suitable for visibility under bright ambient conditions.
[0049] In an embodiment, an example corresponding to the night mode may be considered. For instance, when the system 200 is operated during low-light conditions, such as nighttime operation in an aircraft cockpit or a vehicle dashboard, or when a user activates a night mode through the input interface, the determination module 202 may determine the operational mode as the night mode based on at least one of reduced ambient illumination, predefined temporal ranges, or user-defined input. In such a situation, the control signal generated by the determination module 202 may indicate selection of the night mode, and the luminance control module 204 may activate the plurality of NVG-compatible LEDs 104 while maintaining the plurality of day LEDs 102 in a deactivated state. Further, the luminance control module 204 may regulate the drive current and the PWM duty cycle to produce a reduced luminance level compatible with night vision requirements, thereby avoiding glare and preserving visibility when night vision goggles are used.
[0050] In another embodiment, the time period within a day may be obtained from an internal clock, a real-time clock (RTC), or an external timing source. The determination module 202 may compare the obtained time with predefined temporal ranges corresponding to different operational modes. In an embodiment, time-based determination may be used independently or in combination with ambient light measurements to improve the robustness of mode selection. In an embodiment, system-defined configuration parameters may include predefined thresholds, operating profiles, calibration data, or rule sets stored in the memory or the data storage unit, which define conditions for selecting the operational mode. Such configuration parameters may be application-specific and may be updated during operation to refine system behavior. In another embodiment, user-defined input may override or supplement automated determination, enabling manual selection of the operational mode through an input interface.
[0051] In an embodiment, the determination module 202 may utilize rule-based logic for determining the operational mode, wherein one or more input parameters are evaluated against predefined rules. In another embodiment, the determination module 202 may utilize a weighted evaluation mechanism in which multiple input parameters are assigned relative importance and collectively evaluated to determine the operational mode.
[0052] In an embodiment, the determination module 202 may further store historical data corresponding to previously determined operational modes and associated input parameters within the data storage unit. Such historical data may be utilized to refine threshold values or improve the stability of mode determination over time.
[0053] In an embodiment, the determination module 202 may include validation and error-handling mechanisms to ensure reliability of the determined operational mode. For example, the determination module 202 may detect invalid or inconsistent sensor inputs, apply fallback logic, or default to a predefined operational mode in the absence of reliable input data.
[0054] In an embodiment, the determination module 202 may generate a control signal indicative of the determined operational mode and provide the control signal to the luminance control module 204 for controlling activation and luminance of LEDs. The control signal may be in the form of a digital signal, logic state, or encoded instruction transmitted through an internal communication interface of the system 200.
[0055] In an embodiment, the luminance control module 204 may be configured to control activation of the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 based on the operational mode. In particular, activation is performed such that only one of the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104 is activated at a given time. In an embodiment, the luminance control module 204 may generate control signals to selectively enable one set of LEDs while disabling the other set, thereby preventing simultaneous activation.
[0056] In an embodiment, the luminance control module 204 may be further configured to control luminance of the activated LEDs using a drive current and a pulse-width modulation (PWM) signal. The drive current supplied to the LEDs may be regulated using constant-current drivers to control the intensity of emitted light. The PWM signal may be applied to modulate a duty cycle associated with activation of the LEDs, thereby enabling fine control over perceived brightness.
[0057] In an embodiment, the luminance control module 204 may vary the drive current supplied to the activated LEDs to achieve a desired luminance level corresponding to the operational mode. In another embodiment, the PWM duty cycle may be adjusted to regulate brightness without altering peak current levels.
[0058] In an embodiment, the luminance control module 204 may coordinate the drive current and the PWM duty cycle such that perceived illumination output remains substantially consistent between the day mode and the night mode. In such an embodiment, the relationship between drive current and PWM duty cycle may be determined based on perceptual characteristics of human vision or system-specific calibration data.
[0059] In an embodiment, the luminance control module 204 may apply a predefined mapping between drive current and PWM duty cycle corresponding to the operational mode. Such mapping may be stored in the data storage unit as lookup tables or calibration curves and may be accessed during operation to determine appropriate control parameters.
[0060] In an embodiment, luminance control may be performed based on perceptual calibration parameters, wherein calibration data is used to compensate for differences in optical characteristics between the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104, thereby ensuring consistent perceived brightness across different modes.
[0061] In an embodiment, the system 200 may further comprise a temperature sensor configured to detect temperature conditions associated with the LEDs or the operating environment. The luminance control module 204 may adjust at least one of the drive current and the PWM duty cycle based on temperature variation to compensate for temperature-dependent variations in LED performance.
[0062] In an embodiment, the system 200 may further comprise at least one constant-current driver configured to supply regulated drive current to the plurality of day LEDs 102 and the plurality of NVG-compatible LEDs 104. The constant-current driver may ensure a stable current supply irrespective of voltage variations, thereby improving reliability and consistency of luminance output.
[0063] In an embodiment, the luminance control module 204 may be implemented using dedicated hardware circuitry, firmware instructions executed by the processor, or a combination thereof. The control signals generated by the luminance control module 204 may be transmitted to driver circuitry associated with the LEDs through suitable electrical interfaces.
[0064] Accordingly, the system 200 enables the determination of an operational mode and further facilitates controlled activation and luminance regulation of LEDs in accordance with the operational mode, thereby providing consistent illumination and reliable performance across different operating conditions.
[0065] FIGURE 3 illustrates a flowchart 300 of a method for controlling a backlight system of a display in accordance with an embodiment of the present disclosure. The method begins at step 302.
[0066] At step 304, the method includes providing a printed circuit board (PCB) comprising a plurality of day light-emitting diodes (LEDs) and a plurality of night vision goggle (NVG)-compatible LEDs arranged in an alternating pattern. In an embodiment, each of the plurality of day LEDs is spatially interleaved with at least one of the plurality of NVG-compatible LEDs, thereby enabling substantially uniform spatial distribution of illumination sources across the PCB. In an embodiment, the alternating pattern may comprise a row-wise interleaved arrangement, a linear arrangement, or a matrix-based arrangement, depending on application requirements and display configuration.
[0067] At step 306, the method includes determining an operational mode based on at least one of ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day. In an embodiment, ambient light conditions may be determined using one or more light sensors, and corresponding signals may be processed to obtain an illumination level. In another embodiment, system-defined configuration parameters may include predefined thresholds or operational profiles, while user-defined input may be received through an input interface. The operational mode comprises one of a day mode and a night mode.
[0068] At step 308, the method includes controlling activation of the plurality of day LEDs and the plurality of NVG-compatible LEDs based on the operational mode. In an embodiment, activation is controlled such that only one of the plurality of day LEDs and the plurality of NVG-compatible LEDs is activated at a given time. In an embodiment, control signals may be generated to selectively enable one set of LEDs while disabling the other set, thereby ensuring mutually exclusive activation in accordance with the operational mode.
[0069] At step 310, the method includes controlling luminance of the activated LEDs based on the operational mode using a drive current and a pulse-width modulation (PWM) signal. In an embodiment, the drive current supplied to the activated LEDs may be varied to achieve a desired luminance level corresponding to the operational mode. In another embodiment, the PWM signal may be used to modulate a duty cycle associated with activation of the LEDs to regulate perceived brightness.
[0070] In an embodiment, controlling luminance further comprises coordinating the drive current and the PWM duty cycle such that perceived illumination output remains substantially consistent between the day mode and the night mode. In an embodiment, a predefined mapping between the drive current and the PWM duty cycle corresponding to the operational mode may be applied to determine luminance control parameters.
[0071] In an embodiment, luminance control may be performed based on perceptual calibration parameters to compensate for differences in optical characteristics between the plurality of day LEDs and the plurality of NVG-compatible LEDs. In another embodiment, at least one of the drive current and the PWM signal may be adjusted based on temperature variation to maintain consistent illumination output.
[0072] In an embodiment, the method may be implemented for at least one of a direct lighting configuration, in which the LEDs are arranged behind a display panel, and an edge lighting configuration, in which the LEDs are arranged along edges of a light guide to couple light into the light guide, thereby enabling compatibility with different display architectures. The method ends at step 312.
[0073] Embodiments of the present disclosure provide significant advantages in relation to backlight systems for displays requiring operation across different illumination conditions. Integration of a plurality of day light-emitting diodes (LEDs) and a plurality of night vision goggle (NVG)-compatible LEDs on a single printed circuit board (PCB) enables efficient utilization of available space while avoiding the need for separate hardware arrangements for different operating modes. The alternating arrangement of the plurality of day LEDs and the plurality of NVG-compatible LEDs further enables substantially uniform spatial distribution of illumination sources, thereby supporting consistent illumination characteristics across the display and reducing non-uniformity and visual artifacts.
[0074] Determination of an operational mode based on multiple input parameters, including ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day, enables adaptive and context-aware operation of the backlight system. Such determination allows automatic selection of an appropriate operating condition while supporting user-defined control, thereby improving flexibility and usability across different applications.
[0075] Controlled activation of the plurality of day LEDs and the plurality of NVG-compatible LEDs in accordance with the operational mode ensures that only one type of LED is activated at a given time. This prevents simultaneous activation of incompatible light sources and supports reliable operation under conditions requiring compatibility with night vision systems. The coordinated activation further contributes to stable and predictable illumination behavior across different operating conditions.
[0076] Regulation of the luminance of activated LEDs using a combination of drive current and pulse-width modulation (PWM) enables precise and flexible control of brightness levels. Coordination between drive current and PWM duty cycle allows perceived illumination output to remain substantially consistent between different operational modes, thereby minimizing abrupt visual changes during mode transitions and improving overall viewing experience.
[0077] The use of predefined mappings and perceptual calibration for luminance control further enables compensation for differences in optical characteristics between different types of LEDs, as well as variations arising from manufacturing tolerances or aging effects. Additionally, adjustment of luminance parameters based on temperature variation contributes to maintaining consistent performance under varying environmental conditions.
[0078] The disclosed approach is adaptable to different display configurations, including direct lighting and edge lighting implementations, thereby enabling integration across a wide range of display systems without requiring modification of the PCB arrangement.
[0079] Overall, the present disclosure provides a compact, efficient, and reliable backlight control solution capable of delivering consistent illumination, adaptive operation, and compatibility with diverse operating conditions and display configurations.
[0080] While embodiments of the present disclosure have been illustrated and described, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.
[0081] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C…, and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
[0082] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
, Claims:CLAIMS
We Claim:
1. A system (200) for controlling a backlight system of a display, the system (200) comprising:
a printed circuit board (PCB) (100) comprising a plurality of day light-emitting diodes (LEDs) (102) and a plurality of night vision goggle (NVG)-compatible LEDs (104);
wherein the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104) are arranged on the PCB (100) in an alternating pattern such that each of the plurality of day LEDs (102) is spatially interleaved with at least one of the plurality of NVG-compatible LEDs (104);
a determination module (202) configured to determine an operational mode based on at least one of: ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day, wherein the operational mode comprises one of: a day mode and a night mode; and
a luminance control module (204) configured to:
control activation of the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104) based on the operational mode, wherein only one of the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104) is activated at a given time; and
control luminance of activated LEDs based on the operational mode using a drive current and a Pulse-Width Modulation (PWM) signal.
2. The system (200) as claimed in claim 1, wherein the alternating pattern comprises a row-wise interleaved arrangement of the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104).
3. The system (200) as claimed in claim 1, wherein the luminance control module (204) is configured to vary a drive current supplied to LEDs activated based on the operational mode to achieve a desired luminance level.
4. The system (200) as claimed in claim 1, wherein the luminance control module (204) is configured to control luminance using the PWM having a variable duty cycle.
5. The system (200) as claimed in claim 1, wherein the backlight system is configured for at least one of:
a direct lighting configuration in which the LEDs are arranged behind a display panel; and
an edge lighting configuration in which the LEDs are arranged along the edges of a light guide to couple light into the light guide.
6. The system (200) as claimed in claim 1, wherein the luminance control module (204) is configured to:
coordinate the drive current and the PWM duty cycle such that perceived illumination output remains substantially consistent between the day mode and the night mode;
apply a predefined mapping between the drive current and the PWM duty cycle corresponding to the operational mode;
determine luminance control based on perceptual calibration parameters.
7. The system (200) as claimed in claim 1, further comprising a temperature sensor, wherein the luminance control module (204) is configured to adjust at least one of the drive current and the PWM duty cycle based on temperature variation.
8. The system (200) as claimed in claim 1, further comprising at least one constant-current driver configured to supply drive current to the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104).
9. A method for controlling a backlight system of a display, the method comprising:
providing a printed circuit board (PCB) (100) comprising a plurality of day light-emitting diodes (LEDs) (102) and a plurality of night vision goggle (NVG)-compatible LEDs (104) arranged in an alternating pattern;
wherein each of the plurality of day LEDs (102) is spatially interleaved with at least one of the plurality of NVG-compatible LEDs (104);
determining an operational mode based on at least one of: ambient light conditions, user-defined input, system-defined configuration parameters, and a time period within a day, wherein the operational mode comprises one of a day mode and a night mode;
controlling activation of the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104) based on the operational mode, wherein only one of the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104) is activated at a given time; and
controlling luminance of activated LEDs based on the operational mode using at least one of: a drive current and a Pulse-Width Modulation (PWM) signal.
10. The method as claimed in claim 9, wherein the alternating pattern comprises a row-wise interleaved arrangement of the plurality of day LEDs (102) and the plurality of NVG-compatible LEDs (104).
11. The method as claimed in claim 9, further comprises varying a drive current supplied to LEDs activated based on the operational mode to achieve a desired luminance level.
12. The method as claimed in claim 9,
wherein controlling luminance comprises using the PWM having a variable duty cycle;
wherein controlling luminance comprises coordinating the drive current and the PWM duty cycle such that perceived illumination output remains substantially consistent between the day mode and the night mode;
wherein controlling luminance comprises applying a predefined mapping between the drive current and the PWM duty cycle corresponding to the operational mode;
wherein controlling luminance is performed based on perceptual calibration parameters.
13. The method as claimed in claim 9, further comprises adjusting at least one of the drive current and the PWM signal based on temperature variation.
14. The method as claimed in claim 9, wherein the method is implemented for at least one of:
a direct lighting configuration in which the LEDs are arranged behind a display panel; and
an edge lighting configuration in which the LEDs are arranged along edges of a light guide to couple light into the light guide.