Patent ID: 12211457

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

One or more specific embodiments of the present disclosure will be described below. These described embodiments are only examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but may nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, the phrase A “based on” B is intended to mean that A is at least partially based on B. Moreover, the term “or” is intended to be inclusive (e.g., logical OR) and not exclusive (e.g., logical XOR). In other words, the phrase A “or” B is intended to mean A, B, or both A and B.

Electronic devices often use electronic displays to present visual information. Such electronic devices may include computers, mobile phones, portable media devices, tablets, televisions, virtual-reality headsets, and vehicle dashboards, among many others. To display an image, an electronic display controls the luminance (and, as a consequence, the color) of its display pixels based on corresponding image data received at a particular resolution. For example, an image data source may provide image data as a stream of pixel data, in which data for each pixel indicates a target luminance (e.g., brightness and/or color) of one or more display pixels located at corresponding pixel positions. In some embodiments, image data may indicate luminance per color component, for example, via red component image data, blue component image data, and green component image data, collectively referred to as RGB image data (e.g., RGB, sRGB). Additionally or alternatively, image data may be indicated by a luma channel and one or more chrominance channels (e.g., XYZ, YCbCr, YUV, etc.), grayscale (e.g., gray level), or other color basis. It should be appreciated that a luma channel, as disclosed herein, may encompass linear, non-linear, and/or gamma-corrected luminance values.

Additionally, the image data may be processed to account for one or more physical or digital effects associated with displaying the image data. For example, image data may be compensated for pixel aging (e.g., burn-in compensation), cross-talk between electrodes within the electronic device, transitions from previously displayed image data (e.g., pixel drive compensation), warps, contrast control, and/or other factors that may cause distortions or artifacts perceivable to a viewer.

In some embodiments, the electronic display may include one or more backlights or other illuminators that provide light to multiple pixels. For example, the electronic display may include a single backlight, multiple backlights controlled together, or multiple backlights controlled individually (e.g., according to location on the electronic display and/or according to color component). Using the light generated by the backlight, pixels may control the luminance output that is emitted from the electronic display per color component to regulate the amount and/or color of light emitted according to image data. As used herein, the term “backlight” may refer to a single illuminator or multiple illuminators working in conjunction with one another, controlled individually or in one or more groups, to provide light to pixels of an electronic display.

In some embodiments, the brightness of the backlight may be modulated to adjust the overall brightness of the display or a portion thereof. However, in some scenarios, changing the brightness of the backlight may lead to a color shift in the generated light. As such, the change in color of the backlight may cause the luminance levels for one or more color components to be different from the corresponding image data, leading to visible image artifacts (e.g., discolorations). In particular, the backlight of a quantum dot display panel may generate different color light at different brightness levels.

A quantum dot backlight may include multiple illuminators (e.g., light emitting diodes (LEDs)) that produce light at a particular color. For example, in some embodiments, the illuminators may generate blue light, such as at a particular wavelength (e.g., 450 nanometers (nm) plus or minus 1 nm, plus or minus 2 nm, plus or minus 5 nm, plus or minus 10 nm, plus or minus 25 nm and so on). Additionally, the quantum dot backlight may include one or more quantum dot layers that change a portion of light generated by the illuminators into different color light (e.g., different wavelengths of light). For example, a quantum dot layer may utilize semiconductor crystals (e.g., nanocrystals) to change a portion of the blue generated light into light of different colors, such as red (e.g., 630 nm plus or minus 1 nm, plus or minus 2 nm, plus or minus 5 nm, plus or minus 10 nm, plus or minus 25 nm and so on) and green (e.g., 530 nm plus or minus 1 nm, plus or minus 2 nm, plus or minus 5 nm, plus or minus 10 nm, plus or minus 25 nm and so on). Together, the generated light and the portions of converted light may provide a balanced (e.g., white) combined light with a known (e.g., expected) spectrum that can be regulated (e.g., via pixels programmed via image data) to display an image.

Additionally, in some embodiments, different brightness levels may be achieved by increasing or decreasing the luminance output of the illuminators by changing the power (e.g., current and/or voltage) provided thereto. However, the output color (e.g., wavelength) of the illuminators may be different (e.g., by up to 0.5 nm, up to 1 nm, up to 2 nm, up to 5 nm, up to 10 nm, etc.) at different brightness levels (e.g., associated with different currents). Furthermore, the quantum dot layers may be sensitive to changes in the generated light such that the amounts (e.g., intensities) of converted light may change with the wavelength of the generated light. As such, the spectrum (e.g., intensity vs. color component/wavelength) of the combined light output from the quantum dot backlight may be different at different brightness levels. In other words, the color of the quantum dot backlight may shift based on the brightness level. As should be appreciated, the illuminators (e.g., the color and wavelength thereof) and the relative changes in wavelength by the quantum dot layer(s) may depend on implementation, and the present techniques may be utilized with any suitable quantum dot display panel exhibiting color shifts at different brightness levels.

Embodiments of the present disclosure may include image processing circuitry such as a color shift compensation block to compensate for the different output colors of the backlight at different brightness levels. The color shift compensation block may increase and/or decrease the relative values of the red, blue, and/or green pixel values of the image data to compensate for the different color combined light of the quantum dot backlight. For example, the color shift associated with an increase in brightness may increase the converted red and green color components of the combined light relative to the generated blue light, which may give the generated light of the backlight an increased yellowish hue. As such, the color shift compensation block may determine how much color shift is exhibited at a pixel location and compensate the image data (e.g., by increasing a blue component and/or by decreasing the red and green components) such that the color shift is less or not perceivable (e.g., the emitted light from the display panel is indicative of the desired image).

With the foregoing in mind,FIG.1is an example electronic device10with an electronic display12having independently controlled color component illuminators (e.g., projectors, backlights, etc.). As described in more detail below, the electronic device10may be any suitable electronic device, such as a computer, a mobile phone, a portable media device, a tablet, a television, a virtual-reality headset, a wearable device such as a watch, a vehicle dashboard, or the like. Thus, it should be noted thatFIG.1is merely one example of a particular implementation and is intended to illustrate the types of components that may be present in an electronic device10.

The electronic device10may include one or more electronic displays12, input devices14, input/output (I/O) ports16, a processor core complex18having one or more processors or processor cores, local memory20, a main memory storage device22, a network interface24, a power source26, and image processing circuitry28. The various components described inFIG.1may include hardware elements (e.g., circuitry), software elements (e.g., a tangible, non-transitory computer-readable medium storing instructions), or a combination of both hardware and software elements. As should be appreciated, the various components may be combined into fewer components or separated into additional components. For example, the local memory20and the main memory storage device22may be included in a single component. Moreover, the image processing circuitry28(e.g., a graphics processing unit, a display image processing pipeline, etc.) may be included in the processor core complex18or be implemented separately.

The processor core complex18is operably coupled with local memory20and the main memory storage device22. Thus, the processor core complex18may execute instructions stored in local memory20or the main memory storage device22to perform operations, such as generating or transmitting image data to display on the electronic display12. As such, the processor core complex18may include one or more general purpose microprocessors, one or more application specific integrated circuits (ASICs), one or more field programmable logic arrays (FPGAs), or any combination thereof.

In addition to program instructions, the local memory20or the main memory storage device22may store data to be processed by the processor core complex18. Thus, the local memory20and/or the main memory storage device22may include one or more tangible, non-transitory, computer-readable media. For example, the local memory20may include random access memory (RAM) and the main memory storage device22may include read-only memory (ROM), rewritable non-volatile memory such as flash memory, hard drives, optical discs, or the like.

The network interface24may communicate data with another electronic device or a network. For example, the network interface24(e.g., a radio frequency system) may enable the electronic device10to communicatively couple to a personal area network (PAN), such as a Bluetooth network, a local area network (LAN), such as an 802.11x Wi-Fi network, or a wide area network (WAN), such as a 4G, Long-Term Evolution (LTE), or 5G cellular network.

The power source26may provide electrical power to operate the processor core complex18and/or other components in the electronic device10. Thus, the power source26may include any suitable source of energy, such as a rechargeable lithium polymer (Li-poly) battery and/or an alternating current (AC) power converter.

The I/O ports16may enable the electronic device10to interface with various other electronic devices. The input devices14may enable a user to interact with the electronic device10. For example, the input devices14may include buttons, keyboards, mice, trackpads, and the like. Additionally or alternatively, the electronic display12may include touch sensing components that enable user inputs to the electronic device10by detecting occurrence and/or position of an object touching its screen (e.g., surface of the electronic display12).

The electronic display12may display a graphical user interface (GUI) (e.g., of an operating system or computer program), an application interface, text, a still image, and/or video content. The electronic display12may include a display panel with one or more display pixels to facilitate displaying images. Additionally, each display pixel may represent one of the sub-pixels that control the luminance of a color component (e.g., red, green, or blue). As used herein, a display pixel may refer to a collection of sub-pixels (e.g., red, green, and blue subpixels) or may refer to a single sub-pixel.

As described above, the electronic display12may display an image by controlling the luminance output (e.g., light emission) of the sub-pixels based on corresponding image data. In some embodiments, pixel or image data may be generated by an image source, such as the processor core complex18, a graphics processing unit (GPU), or an image sensor (e.g., camera). Additionally, in some embodiments, image data may be received from another electronic device10, for example, via the network interface24and/or an I/O port16. Moreover, in some embodiments, the electronic device10may include multiple electronic displays12and/or may perform image processing (e.g., via the image processing circuitry28) for one or more external electronic displays12, such as connected via the network interface24and/or the I/O ports16.

The electronic device10may be any suitable electronic device. To help illustrate, one example of a suitable electronic device10, specifically a handheld device10A, is shown inFIG.2. In some embodiments, the handheld device10A may be a portable phone, a media player, a personal data organizer, a handheld game platform, and/or the like. For illustrative purposes, the handheld device10A may be a smartphone, such as an IPHONE® model available from Apple Inc.

The handheld device10A may include an enclosure30(e.g., housing) to, for example, protect interior components from physical damage and/or shield them from electromagnetic interference. The enclosure30may surround, at least partially, the electronic display12. In the depicted embodiment, the electronic display12is displaying a graphical user interface (GUI)32having an array of icons34. By way of example, when an icon34is selected either by an input device14or a touch-sensing component of the electronic display12, an application program may launch.

Input devices14may be accessed through openings in the enclosure30. Moreover, the input devices14may enable a user to interact with the handheld device10A. For example, the input devices14may enable the user to activate or deactivate the handheld device10A, navigate a user interface to a home screen, navigate a user interface to a user-configurable application screen, activate a voice-recognition feature, provide volume control, and/or toggle between vibrate and ring modes. Moreover, the I/O ports16may also open through the enclosure30. Additionally, the electronic device may include one or more cameras36to capture pictures or video. In some embodiments, a camera36may be used in conjunction with a virtual reality or augmented reality visualization on the electronic display12.

Another example of a suitable electronic device10, specifically a tablet device10B, is shown inFIG.3. The tablet device10B may be any IPAD® model available from Apple Inc. A further example of a suitable electronic device10, specifically a computer10C, is shown inFIG.4. For illustrative purposes, the computer10C may be any MACBOOK® or IMAC® model available from Apple Inc. Another example of a suitable electronic device10, specifically a watch10D, is shown inFIG.5. For illustrative purposes, the watch10D may be any APPLE WATCH® model available from Apple Inc. As depicted, the tablet device10B, the computer10C, and the watch10D each also includes an electronic display12, input devices14, I/O ports16, and an enclosure30. The electronic display12may display a GUI32. Here, the GUI32shows a visualization of a clock. When the visualization is selected either by the input device14or a touch-sensing component of the electronic display12, an application program may launch, such as to transition the GUI32to presenting the icons34discussed inFIGS.2and3.

Turning toFIG.6, a computer10E may represent another embodiment of the electronic device10ofFIG.1. The computer10E may be any suitable computer, such as a desktop computer, a server, or a notebook computer, but may also be a standalone media player or video gaming machine. By way of example, the computer10E may be an iMac®, a MacBook®, or other similar device by Apple Inc. of Cupertino, California. It should be noted that the computer10E may also represent a personal computer (PC) by another manufacturer. A similar enclosure30may be provided to protect and enclose internal components of the computer10E, such as the electronic display12. In certain embodiments, a user of the computer10E may interact with the computer10E using various peripheral input devices14, such as a keyboard14A or mouse14B, which may connect to the computer10E.

As described above, the electronic display12may display images based at least in part on image data. Before being used to display a corresponding image on the electronic display12, the image data may be processed, for example, via the image processing circuitry28. In general, the image processing circuitry28may process the image data for display on one or more electronic displays12. For example, the image processing circuitry28may include a display pipeline, memory-to-memory scaler and rotator (MSR) circuitry, warp compensation circuitry, or additional hardware or software means for processing image data. The image data may be processed by the image processing circuitry28to reduce or eliminate image artifacts, compensate for one or more different software or hardware related effects, and/or format the image data for display on one or more electronic displays12. As should be appreciated, the present techniques may be implemented in standalone circuitry, software, and/or firmware, and may be considered a part of, separate from, and/or parallel with a display pipeline or MSR circuitry.

To help illustrate, a portion of the electronic device10, including image processing circuitry28, is shown inFIG.7. The image processing circuitry28may be implemented in the electronic device10, in the electronic display12, or a combination thereof. For example, the image processing circuitry28may be included in the processor core complex18, a timing controller (TCON) in the electronic display12, or any combination thereof. As should be appreciated, although image processing is discussed herein as being performed via a number of image data processing blocks, embodiments may include general purpose and/or dedicated hardware or software components to carry out the techniques discussed herein.

The electronic device10may also include an image data source38, a display panel40, and/or a controller42in communication with the image processing circuitry28. In some embodiments, the display panel40of the electronic display12may be a reflective technology display, a liquid crystal display (LCD), or any other suitable type of display panel40. In some embodiments, the controller42may control operation of the image processing circuitry28, the image data source38, and/or the display panel40. To facilitate controlling operation, the controller42may include a controller processor44and/or controller memory46. In some embodiments, the controller processor44may be included in the processor core complex18, the image processing circuitry28, a timing controller in the electronic display12, a separate processing module, or any combination thereof and execute instructions stored in the controller memory46. Additionally, in some embodiments, the controller memory46may be included in the local memory20, the main memory storage device22, a separate tangible, non-transitory, computer-readable medium, or any combination thereof.

The image processing circuitry28may receive source image data48corresponding to a desired image to be displayed on the electronic display12from the image data source38. The source image data48may indicate target characteristics (e.g., pixel data) corresponding to the desired image using any suitable source format, such as an RGB format, an αRGB format, a YCbCr format, and/or the like. Moreover, the source image data may be fixed or floating point and be of any suitable bit-depth. Furthermore, the source image data48may reside in a linear color space, a gamma-corrected color space, or any other suitable color space. As used herein, pixels or pixel data may refer to a grouping of sub-pixels (e.g., individual color component pixels such as red, green, and blue) or the sub-pixels themselves.

As described above, the image processing circuitry28may operate to process source image data48received from the image data source38. The image data source38may include captured images from cameras36, images stored in memory, graphics generated by the processor core complex18, or a combination thereof. Additionally, the image processing circuitry28may include one or more sets of image data processing blocks50(e.g., circuitry, modules, or processing stages) such as a color shift compensation (CSC) block52. As should be appreciated, multiple other processing blocks54may also be incorporated into the image processing circuitry28, such as a color management block, a dither block, a pixel contrast control (PCC) block, a burn-in compensation (BIC) block, a scaling/rotation block, etc. before and/or after the CSC block52. The image data processing blocks50may receive and process source image data48and output display image data56in a format (e.g., digital format and/or resolution) interpretable by the display panel40. Further, the functions (e.g., operations) performed by the image processing circuitry28may be divided between various image data processing blocks50, and, while the term “block” is used herein, there may or may not be a logical or physical separation between the image data processing blocks50.

As discussed further herein, in some embodiments, the CSC block52may compensate image data for color shifts associated with brightness changes to the electronic display12. As should be appreciated, a brightness setting may define a global luminance output of the electronic display12. Indeed, while display pixels of an electronic display12vary the luminance and/or color outputs therefrom depending on the image data, the brightness setting (e.g., a display brightness value (DBV), global brightness setting, etc.) may regulate the overall brightness (e.g., total luminance output) of the electronic display12by increasing or decreasing an amount of light generated by a backlight of the display panel40. For example, the voltages and/or currents provided to illuminators of the backlight may be increased to increase the brightness level of electronic display12, such as based on the brightness setting. As should be appreciated, the brightness setting may be obtained/determined based on numerous factors such as but not limited to ambient lighting (e.g., received via an ambient light sensor), time of day, panel age, and/or a user setting.

In some embodiments, the electronic display12may include a quantum dot display panel58with multiple illuminators60(e.g., light emitting diodes (LEDs)) that produce light for a grid62of pixel locations64, as shown inFIG.8. As should be appreciated, the number, layout, and relative sizes of the illuminators60and pixel locations64of the grid62are shown for illustrative purposes only and are, as such, non-limiting. In general, a quantum dot display panel58may utilize multiple illuminators60distributed across the display panel40to produce generated light66at a particular color. For example, in some embodiments, the generated light66may be blue light at a particular wavelength (e.g., 450 nanometers (nm) plus or minus 1 nm, plus or minus 2 nm, plus or minus 5 nm, plus or minus 10 nm, plus or minus 25 nm and so on). Additionally, the quantum dot display panel58may include one or more quantum dot layers68that change a portion of generated light66of the illuminators60into different color light (e.g., different wavelengths of light). For example, a quantum dot layer68may utilize semiconductor crystals (e.g., nanocrystals) to change a portion of blue generated light66into different colors, such as red converted light70A (e.g., 630 nm plus or minus 1 nm, plus or minus 2 nm, plus or minus 5 nm, plus or minus 10 nm, plus or minus 25 nm and so on) and green converted light70B (e.g., 530 nm plus or minus 1 nm, plus or minus 2 nm, plus or minus 5 nm, plus or minus 10 nm, plus or minus 25 nm and so on), cumulatively converted light70. Together, the generated light66and converted light70may provide a balanced (e.g., white) combined light72with a known (e.g., expected) spectrum that can be regulated via a pixel layer74(e.g., of display pixels) based on the display image data56. The pixel layer74may include display pixels that regulate a transmissivity of different color components. Moreover, as used herein, a display pixel may refer to a single color component display pixel or a group of sub-pixels including multiple color component display pixels (e.g., a red display pixel, a blue display pixel, and a green display pixel). Furthermore, as used herein, the quantum dot display panel58includes a quantum dot backlight including the illuminators60and the quantum dot layer(s)68. As should be appreciated, the different converted lights70(e.g., red converted light70A and green converted light70B) may be produced in a single quantum dot layer68or in individual quantum dot layers68. Moreover, as should be appreciated, the illuminator60, quantum dot layer68, and pixel layer74ofFIG.8are shown as functional layers and may or may not be linearly stacked, and there may or may not be physical distinctions therebetween. For example, one or more layers, such as the pixel layer74and the quantum dot layer68, may be formed together.

Furthermore, in some embodiments, different brightness levels may be achieved by increasing or decreasing the luminance output of the illuminators60by changing the power (e.g., current and/or voltage) provided thereto. However, the color (e.g., wavelength) of the generated light66from the illuminators60may be different (e.g., by up to 0.5 nm, up to 1 nm, up to 2 nm, up to 5 nm, up to 10 nm, up to 25 nm, and so on) at different brightness levels. For example,FIG.9is a graph76of the wavelength78of the generated light66from an illuminator60relative to an applied current80to the illuminator60. As should be appreciated, the wavelength78and the applied current80of the graph76are normalized and may be indicative of any color and/or type of illuminator60. Indeed, as the applied current80is increased, such as to increase the brightness level (e.g., luminance output), the wavelength78of the generated light66may also change. As such, the change in brightness level may alter the color of the combined light72produced by the backlight.

Furthermore, the quantum dot layer(s)68may be sensitive to changes in the generated light66such that the amounts (e.g., intensities) of converted light70may change with the wavelength of the generated light66. To help illustrate,FIG.10is a graph82of the relative intensity84of the wavelengths78of the combined light72-1at a first brightness level (BL1) and the combined light72-2a second brightness level (BL2). Indeed, the spectrum (e.g., intensity84vs. color component/wavelength78) of the combined light72output from the quantum dot backlight may be different at different brightness levels. In other words, the color of the quantum dot backlight may shift based on the brightness level. As should be appreciated, the illuminators60(e.g., the color and wavelength thereof) and the relative changes in wavelength78by the quantum dot layer(s)68may depend on implementation, and the present techniques may be utilized with any suitable quantum dot display panel58exhibiting color shifts (e.g., color differences) at different brightness levels.

As discussed above, the brightness of the backlight may be modulated to adjust the overall brightness of the electronic display12or a portion thereof. However, changing the brightness of the backlight may lead to a color shift in the generated light66and/or the intensities84of the converted light70and, therefore, the combined light72. The change in color of the combined light72, if uncompensated, may cause visible image artifacts (e.g., discolorations). As such, in some embodiments, a portion of the image processing circuitry28such as the color shift compensation block52may compensate for the different output colors of the quantum dot backlight at different brightness levels. Indeed, the color shift compensation block52may increase and/or decrease the relative values of the red, blue, and/or green pixel values of the image data (e.g., display image data56) to compensate for the different color combined light72of the quantum dot backlight. For example, the color shift associated with an increase in brightness may increase the red converted light70A and the green converted light70B color components of the combined light72relative to the blue generated light66, which may increase/produce a yellowish hue in the combined light72. As such, the color shift compensation block52may determine how much color shift is exhibited at a pixel location64and compensate the image data (e.g., by increasing a blue component and/or by decreasing the red and green components) such that the color shift is less or not perceivable.

Returning briefly toFIG.8, In some embodiments, the backlight of the quantum dot display panel58may include multiple illuminators60controlled together (e.g., in one or more groups) or controlled individually (e.g., according to location on the electronic display12). For example, illuminators60along edges of the electronic display12may be maintained at a reduced brightness level relative to illuminators60closer to the center of the electronic display12, such as part of vignetting or other effect. Furthermore, a pixel location of interest86(e.g., corresponding to a display pixel of the pixel layer74) may receive light contributions from multiple illuminators60(e.g., illuminators60A-60I). In other words, the combined light72regulated by a pixel at a pixel location of interest86may be sourced (e.g., directly and/or indirectly via the quantum dot layer(s)68) from multiple illuminators60. As such, the color of the combined light72received from the multiple different illuminators60may or may not be uniform. For example, illuminators60closer to a pixel location of interest86, such as illuminator60E, may provide a higher contribution of combined light72to the pixel location of interest86than an illuminator60further from the pixel location of interest86, such as illuminator60G. In some embodiments, contributions from different illuminators60may be considered separately and/or in an aggregate when generating compensations to image data for shifts in the color of the combined light72at a pixel location of interest86.

To help illustrate,FIG.11is a schematic diagram of a portion of the color shift compensation block52that receives input pixel values88, implements a pixel modification90to compensate for color shifts of the quantum dot backlight, and outputs compensated pixel values92. In some embodiments, the color shift compensation block52may obtain the luminance contributions94of one or more illuminators60for a pixel location of interest86. For example, the luminance contributions94may be measures of how much light (e.g., combined light72) is attributable to different illuminators60, such as based on the relative locations of the illuminators60and the pixel location of interest86. Moreover, in some embodiments, the luminance contributions94may be normalized to sum to one for the pixel location of interest86. In some embodiments, the luminance contributions94may include contributions from all of the illuminators60of the quantum dot display panel58or a subset thereof. For example, such a subset may include 9 illuminators, 16 illuminators, 108 illuminators, or any suitable number of illuminators60depending on implementation. Moreover, illuminators60included in the subset may be those that contribute greater than a threshold amount of luminance to the pixel location of interest86, within a threshold distance from the pixel location of interest86, and/or be fixed relative to the portion of the grid62surrounding the pixel location of interest86.

The luminance contributions94(e.g., normalized luminance contributions) based on locations of the illuminators60may be multiplied by their corresponding brightness96to achieve the luma contribution values98(e.g., Y channel color components of a chromatic color space such as XYZ, YUV, YCbCr, etc.) of each illuminator60. Additionally, conversion profiles100A and100B (cumulatively100) of the quantum dot layer(s)68that convert portions of the generated light66to converted light70may be used to obtain the chromatic channel contributions102A and102B, respectively, to the combined light72of the illuminators60. As discussed above, the illuminators60may be controlled separately (e.g., independently or in groups) and, therefore, may have different brightnesses96. As such, each illuminator60may have separate color shifts contributing to the combined light72at the pixel location of interest86. As such, in some embodiments, the luma contribution value98of each illuminator60may be used to obtain color corrections104(e.g., compensations) to the luma contribution contribution values98and chromatic channel contributions102A and102B. For example, quantum dot compensation circuitry106may utilize an algorithm, look-up-table, or other technique to generate the color corrections104based on the luma contribution values98of the illuminators60. The color corrections104for each color component (e.g., luma contribution value98and chromatic channel contributions102A and102B) of each illuminator60may be combined (e.g., multiplied as a gain and/or added as an offset) with the respective luma contribution values98and chromatic channel contributions102A and102B of the illuminators to achieve the corrected (e.g., estimated to be the actual output) luma contribution values and chromatic channel contributions for each illuminator60, and the corrected contributions of each illuminator60may be summed to generate a corrected total luma value108and corrected total chromatic components110A and110B, the combination of which is estimated to be the actual color of the combined light72at the pixel location of interest86.

As should be appreciated, obtaining color corrections104for each illuminator60assumed to have a contribution at the pixel location of interest86may include performing such calculations for many (e.g., greater than 3, greater than 20, greater than 100, etc.) illuminators60, which may be hardware and/or software resource intensive. In some embodiments, the luma contribution values98and chromatic channel contributions102A and102B may be respectively summed, prior to computing the color corrections104, to obtain a total luma value112and total chromatic components114A and114B. The color corrections104may then be determined (e.g., via the quantum dot compensation circuitry106) based on the total luma value112. By performing the sum before computing the color corrections104, the number of color corrections104and associated computations may be reduced for increased efficiency. The color corrections104based on the total luma value112may be combined (e.g., multiplied as a gain and/or added as an offset) with the respective total luma value112and total chromatic components114A and114B to obtain the corrected total luma value108and the corrected total chromatic components110A and110B.

Based on the corrected color (e.g., defined by the corrected total luma value108and the corrected total chromatic components110A and110B) of the quantum dot backlight at the pixel location of interest86, the color shift compensation block52may determine the pixel modification90to the input pixel values88, such as via pixel compensation circuitry116. For example, in some embodiments, the corrected total luma value108and the corrected total chromatic components110A and110B may be converted to an RGB color space (e.g., via an XYZ to RBG conversion118) or other color space of the input pixel values88. Moreover, in some embodiments, the target RGB color (e.g., the estimated color of the combined light72at the corrected total luma value108if no color shift occurred) may be determined (e.g., via a target RGB conversion120). The target RGB color and corrected color of the combined light72in RGB format may be used (e.g., via a compensation calculation122) to determine pixel corrections124(e.g., pixel compensations to the image data) for each of the RGB color components of the input pixel values88. As should be appreciated, while discussed herein as in the RGB color space, any suitable color space, such as the color space of the input pixel values88may be utilized (e.g., converted to and used for calculating the pixel corrections124). Moreover, the pixel corrections124may be calculated as gains and/or offsets to be combined (e.g., multiplied and/or added, respectively) during pixel modification90to generate the compensated pixel values92.

As should be appreciated, portions of the pixel compensation circuitry116are shown as examples, and additional, fewer, and/or different conversions and calculations may be used therein to determine the pixel corrections124. Moreover, in some embodiments, one or more aspects of the color shift compensation block52may be combined and/or implemented together. For example, the quantum dot compensation circuitry106and pixel compensation circuitry116may be implemented together (e.g., in hardware, software, or a combination thereof) such that the pixel corrections124are determined based on the total luma value112or the collection of multiple luma value contributions98for the pixel location of interest86.

To help further illustrate,FIG.12is a flowchart126of an example process for compensating input pixel values88to account for a color shift associated with different quantum dot backlight brightnesses. In some embodiments, the color shift compensation block52may determine brightnesses of illuminators60of a quantum dot backlight of a quantum dot display panel58(process block128). Additionally, the color shift compensation block52may determine per color component (e.g., in an XYZ or other chromatic color space) contributions (e.g., luma contributions values98and chromatic channel contributions102) of the quantum dot illuminators60for a pixel location of interest86based on the brightnesses (process block130). For example, normalized luminance contributions94may be used along with the brightnesses of individual illuminators60to determine luma contribution values98, and the luma contribution values98may be used along with conversion profiles100to determine chromatic channel contributions102. Additionally, the per color component contributions (e.g., luma contributions values98and chromatic channel contributions102) may be summed, respectively, to obtain per color component total luminance intensities (e.g., a total luma value112and total chromatic components114) for the pixel location of interest86(process block132). Additionally, the color shift compensation block52may determine per color component color corrections104based on a total luma value112of a luma channel of the per color component total luminance intensities (process block134). The per color component color corrections104and the per color component total luminance intensities (e.g., total luma value112and total chromatic components114) may be combined (e.g., via summation or multiplication) to obtain per color component corrected luminance intensities (e.g., corrected total luma value108and the corrected total chromatic components110) for the pixel location of interest86(process block136). As should be appreciated, the per color component corrected luminance intensities may, cumulatively, be indicative of the estimated color of the combined light72at the pixel location of interest86. Based on the per color component corrected luminance intensities, per color component pixel corrections124(e.g., compensations) may be determined for the pixel location of interest86(process block140). Moreover, input pixel values88for a display pixel corresponding to the pixel location of interest86may be compensated based on the per color component pixel corrections124to generate compensated pixel values92(process block142).

As discussed herein, a color shift compensation block52of image processing circuitry28may reduce the likelihood of image artifacts (e.g., discoloration) due to color shifts in a quantum dot backlight at different brightnesses. Although the above flowchart126is shown in a given order, in certain embodiments, process/decision blocks may be reordered, altered, deleted, and/or occur simultaneously. Additionally, the flowchart126is given as an illustrative tool and further decision and process blocks may also be added depending on implementation.

The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112 (f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112 (f).