Display system with modulating front plane

Abstract

The present invention discloses a display system with a frontplane which is capable of modulating lights to create images and back light for generating lights and colors, a display with a full-color back light array and frontplane monochrome light modulating array having a low power mode and also front plane light modulation element enabled to improve the resolution by modulating brightness of areas in each pixel associated with a lower resolution image.

Description

DISPLAY SYSTEM WITH MODULATING FRONT PLANEField of the Invention

[0001] The present disclosure relates to a display system with a front plane which is capable of modulating lights to create images and back light for generating lights and colors.Summary

[0002] The present invention relates to a display system comprising, a front plane with no color filter, a back light configured to give color definition, a front plane light modulation element enabled to improve the resolution by modulating brightness in each pixel associated with a lower resolution image and wherein the back light and front plane are synched and a frame rate is adjusted without any risks associated with color sequential effect at low frame rates.Brief Description of the Drawings

[0003] The foregoing and other advantages of the disclosure will become apparent upon reading the following detailed description and upon reference to the drawings.

[0004] FIG. 1 shows a back light with array of light sources, with at least one zone with more than one type of light source.

[0005] FIG. 2A and 2B show an example of the timing and function of the front plane and back light during the subframes. FIG. 2A shows sequential color programming. FIG. 2B shows interleave color programming.

[0006] FIG. 3A shows the light sources creating a light cone. The front plane is adjusted to have uniform light output from each pixel.

[0007] FIG. 3B shows posts that can be random or follow a pattern on the back light substrate.

[0008] FIG. 3C shows transparent material between the back light and the front plane.

[0009] FIG. 4A shows a lightguide with an angled structure around the devices and the base at the backlight, smaller than the front coupling to the front plane.

[0010] FIG. 4B shows the structure with the reverse angle on the substrate.

[0011] FIG. 4C shows a cross-sectional view of the structure with the reverse angle on the substrate as shown in FIG. 4B.

[0012] FIG. 5 shows an embodiment that permits a higher frame rate.

[0013] FIG. 6 shows a high-performance display.

[0014] FIG. 7A shows a process cycle for image creation using a full-color display as back light and a higher-resolution monochrome front display using separate subframe for each primary color.

[0015] FIG. 7B shows a process cycle for image creation using a full-color display as back light and a higher-resolution monochrome front display in a low power mode using single subframe.

[0016] FIG. 7C shows a process cycle for image creation using a full-color display as back light and a higher-resolution monochrome front display using subframes with more than one color created during each subframe.

[0017] FIG. 8 shows a processing step to create images for full-color low-resolution and high- resolution emissive displays.

[0018] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments or implementations have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of an invention as defined by the appended claims.Detailed Description

[0019] The present invention relates to a display system with a front plane capable of modulating lights to create images, a back light for generating lights and colors Where back lights have an array of multiple zones, and each zone has at least two different types of devices generating different light wavelengths, and each zone can generate different brightness and different colors based on the front plane image. The front plane is aligned with the back light.

[0020] In FIG. 1 demonstrate A display system has a back light unit 112 and a light modulation front plane. The back light has an array of light sources, with at least one zone with more than one type of light source.

[0021] The light source can have different color points 102, 104, and 106, such as primary colors (red, green, blue) or other color points, such as white, yellow, etc. The light sources can be microLED. They can be grouped 108 so that each group includes a set of different color devices. Each light source group 108 corresponds to multiple pixels 110 in the display.

[0022] The following process can be used to determine the brightness and color associated with each light source group:1. Using the color point and brightness of each pixel associated with the light source group, calculate the brightness of each light source.2. Pick the highest value for each light source in the group from the set of calculated brightness values.3. Translate the selected max brightness values to the driving conditions that offer that brightness to all the pixels associated with the light source group. In one case, the brightness value can be multiplied by the number of pixels associated with the light source group. In another related embodiment, the effect of the adjacent light source group is considered in calculating the driving condition of the current light source group.

[0023] In another related embodiment, a function is defined based on the impact of each light source on the pixels. Then, the image is processed, and the value of each light source is calculated so that the sum of the lights and colors from each light source can meet the requirements for each pixel.

[0024] In another related embodiment, the image may need to be modified to optimize the power consumption of the back light. For example, suppose the number of pixels in a zone with max brightness is less than a threshold. In that case, that value is not considered in the calculator, or a weighted number of the value is considered in the calculation.

[0025] In one embodiment, the light source group associated with the pixels being programmed with new images is turned off. The pixel is programmed with the latest data, and the light source group is turned on with the new values.

[0026] In another related embodiment, one pixel has multiple sub-pixels associated with different color points that might differ from the back light color points. The color of sub-pixels may be defined by a color filter allowing specific colors to pass through the sub-pixels

[0027] In another related embodiment, at least one sub-pixel in the pixel is associated with two color points for the pixel. Here, the front plane is programmed at least twice (the same number associated with the color point of one sub-pixel), and the back light is programmed to the same number each time with a different color point.

[0028] In one related case, the pixel produces three primary colors such as red, green, and blue. Each frame is divided into the primary colors associated with the front plane. The back light has different devices with color points similar to red, green, and blue. Here, during the first sub-frame, a section of the front plane is programmed with the first primary color while the back light group associated with that section of the display is programmed to be off. After theprogramming, the device in the back light with the primary color point associated with the programmed front plane color turns ON based on the calculated values. After a predefined emission time, the second sub-frame starts. The back light group turns off, the front plane section is programmed with a different primary color value, and the back light turns on with calculated values with the second primary color. This process continues until all the primary colors associated with the image and application of the display are demonstrated. The process can continue with different frame cycles.

[0029] Here, the pixel does not have a color filter so that each primary color can pass through. This results in the possibility of using smaller pixels in the front plane as there is only one subpixel, allowing higher resolution displays. Furthermore, the lack of a color filter makes the pixel more efficient. Here, the color and brightness generated by the back light pass through the pixels without losing a portion due to the color filter.

[0030] In a related embodiment, the back light can generate a pseudo color point, a combination of two or more colors available in the back light device. This mode can create an extra subframe for combined colors such as white. This mode can also be used in another related case when the display can go to a static image or low frame rate. In another related case, monochrome images can be used for specific applications.

[0031] The front plane pixel can be smaller, the same size or larger than the light sources.

[0032] FIG.’s 2 A and 2B show an example of the timing and function of the front plane and back light during the subframes. Here, when a section of display (zone) goes to programming mode, the associated back light zone (group) also goes to black or programming. During the programming, the pixel's content in the front plane is updated with the new frame information. The brightness of the back light devices is also updated to represent the new frame date for the front plane pixels. To avoid cross talk or unwanted emission, the back light is in black mode during the programming cycle of the zone. The black mode for a back light can be longer than the programming time of the front plane zone.

[0033] In one related case, in FIG. 2A the back light zone is updated with the same color in every subframe. FIG. 2A shows sequential color programming.

[0034] FIG. 2B shows interleave color programming. Each zone can be updated with a different color in another related embodiment during the same subframe.

[0035] In one related embodiment, the space between the back light and backplane is adjusted to make the output light from the front plane uniform. In another related embodiment, alignment marks exist in the front plane and backplane so that they can get aligned. In another related embodiment, different light patterns are shown in the front plane, and the position ofthe front plane and / or backplane is adjusted so that each pattern has the correct brightness and correct color. The back light may also be programmed with different patterns to highlight the misalignment. In one related embodiment, the back light and front plane are secured by adhesive or other methods after the adjustment. There can be posts between the backplane and front plane to prevent the collapse of two substrates to each other.

[0036] An optically transparent film can fill the space between the front plane and the back light substrate. A fine film is formed on the backplane with controlled thickness in another related embodiment. The front plane is attached to the film. The film can be adhesive, or another adhesive layer can be formed between the front plane or transparent film to facilitate the lamination of the front plane to the back light. The film can be patterned to an isolated area for each zone in one related embodiment. A reflective layer covers the area between each zone to prevent light leakage between the zones.

[0037] The zone associated with each light source group is isolated in another related embodiment. Here, a bank structure can be used to separate each group. The bank layer can have a reflective layer to help with the light isolation and guiding into the zones.

[0038] A light guide structure can guide each zone's light to associated pixels in another related embodiment.

[0039] FIG. 3 shows an example of back light and front plane alignment. Here, the back light has different devices for each zone (306, 308, 310) on a backplane 302.

[0040] In FIG. 3 A, the light sources create a light cone 312, 314, 316. The front plane 304 is adjusted to have uniform light output from each pixel. Here, a pattern can be used in the back light and the front plane to adjust the distance between the front plane 304 and back light 302 substrates. Also, a light pattern in the back light and an image pattern in the front plane can be used to align each zone in the front plane with the associated zone in the back light. There can also be alignment marks 330 and 332 in the back light substrate and front plane to perform the alignment process.

[0041] Posts can be developed on the back light to assist in uniform spacing between the front plane and back light.

[0042] FIG. 3B shows posts 318 that can be random or follow a pattern on the back light substrate 302.

[0043] FIG. 3C shows transparent material 320 between the back light and the front plane. The transparent material can be patterned to isolate each zone. They can also be a lightguide for better isolation and light coupling between the front plane and the back light.

[0044] FIG. 4 A shows a lightguide with an angled structure around devices 406, 408, 410, andthe base 402 at the back light, smaller than the front 404 coupling to the front plane. There can be reflective layers on the sidewall of the structure to enhance coupling further. One method of fabricating such a structure is to develop it on a separate substrate.

[0045] FIG. 4B shows structure 422 with the reverse angle on substrate 420. This structure can be developed using polymer and photolithography, wet etching, or dry etching. After the base is developed, other layers, such as the reflector and opening for device coupling, are formed.

[0046] The cross-section from the cut line 424 is shown in FIG. 4C. Here, base 422 is formed on substrate 420. A reflector layer 426 is formed (by PECVD, e-beam, sputtering or other means) on the top of the base. The reflective layer is opened at 428 where the microdevice 406, 408, 410 will be coupled. The base can be etched to create a housing structure for the devices. The structure is aligned with the back light and then bonded to the back light. The structure can be released from the original substrate 420. The release can be mechanical, laser, chemical or other processes.

[0047] In another related embodiment, the banks are formed on a separate substrate. Here, transparent polymer or other dielectric layers are formed on the substrate and etched or stamped to form sloped structures. Reflective layers are deposited on top of the sloped structure. The reflective layer can be removed from an area on top of the sloped structure. Part of the same area can be etched further to create a housing for light devices.

[0048] The sloped structure is aligned with light devices. The structure is bonded to the surface of the back light (or display) substrate. A reflective layer can be under the light-generating devices in the back light (or display) substrate. The substrate from the sloped substrate can be removed. In another related embodiment, the sloped substrate is formed on the back of the front plane substrate.

[0049] In all the embodiments presented here, the light modulation arrays should operate at a higher frame rate to allow different color sub-frames.

[0050] FIG. 5 shows an embodiment that permits a higher frame rate. Here, several rows are programmed at the same time using separate data lines. In one related embodiment, the select lines that enable the pixels to capture the data from the data lines (DATA) are activated simultaneously for the several rows being programmed simultaneously. Here, the select lines (SEL) are connected to one source or have different simultaneously programmed sources. The select lines (SEL) can also be shared between the rows that are being programmed simultaneously. In one example, each column has three data lines (DATA [j, 1 :3]). Each data line is connected to a pixel in a different row. The select lines (SEL) associated with a pixel set connected to these data lines are activated simultaneously, allowing pixels in different rowsto be programmed simultaneously. The rows programmed simultaneously can be adjacent or spread in different parts of the arrays. The rows in the array are divided into multiple sets, and each set is programmed simultaneously.

[0051] In one related embodiment, the low-resolution image created by back light has full color information and brightness. The front plane light modulation element improves the resolutions by modulating the brightness of the areas in each pixel associated with the lower resolution image. Here, the front plane has no color filter and as such color definition only comes from the back light. Furthermore, there is no need to run the front plane at a higher frame rate. Also, since back light and front plane are synched, the frame rate can be adjusted without any challenge associated with color sequential effect at low frame rates.

[0052] In another embodiment, the display can have two modes, high image quality mode where the color sequential is used with each subframe creating a low resolution of single color in back light and associated high resolution image in the front plane. In low power mode, the display has one frame, and the back light has full color information and low pixel resolution. The high-resolution image created in the front plane only modulates the brightness.

[0053] In another related embodiment, there are more than subframes. During each subframe a full color image is created in the back light and the front plane light modulation element (LME) is programmed to enhance the image resolution. In one case, a first image is created using back light full color and front monochrome LME. The error between the created image and actual image is calculated and a second image is created using back light and front LME. The first and second images are shown during two different sub-frames. There can be a 3rd image too and a 3rd subframe to reduce the error between the created images and the actual images.

[0054] In another related embodiment, the first image is created to limit the sub-pixel brightness error for each pixel within a threshold boundary. The threshold boundaries can have an upper limit and a lower limit. The second image is also created based on the difference between the created image and the actual image to reduce the error furthermore. This process can extend to more than the first and second images.

[0055] In one related embodiment, the subframes and images created for each subframe can be transitional between two actual images. Here, the 2nd or 3rd subframe can have information from the first actual image and 2nd actual image. The information can be interpolated data between the two actual images.

[0056] A display system comprises a low-resolution full-color emissive display, a monochrome high-resolution light modulation display, and a controller. The controller isresponsible for creating images for each frame and synchronizing the two displays. The emissive display can use microLEDs to produce the image.

[0057] FIG. 6 shows the system structure with controller 510, emissive low-resolution display 512, and high-resolution light modulation display 514. The controller 510 takes an image 502 and creates two images 504 and 506 for each display 512 and 514. Each pixel in a low- resolution display is mapped to multiple pixels in the high-resolution display (e.g., zone).

[0058] The display system as shown in FIG. 6 can operate in different modes.

[0059] During the high-efficiency mode, as demonstrated in FIG. 7A, the controller produces different sets of images representing the primary color of the displays. For example, if the display has red, green, and blue as primary colors, the missive display can also produce these primary colors. In this case, the controller produces three image sets (red, green, and blue) for the two displays. The frame is divided into three subframes, and each subframe shows information on each color on both displays. The original image 600 is divided into subframes and low-resolution and high-resolution photos. Then, during the subsequent cycles 602 and 604, a corresponding low-resolution image is used to program the emissive display, and its counterpart, a high-resolution image, is used to program the monochrome display. This cycle continues, as in cycle 606, till all the subframes are finished and a new image is set for display.

[0060] Dividing images into low and high resolutions for each subframe can be done using different processes. In one related embodiment, the maximum value of each primary color is extracted for each zone. The value is multiplied by the number of high-resolution pixels in each zone. The value is used to set the low-resolution corresponding pixel. The pixels for high- resolution displays are programmed with values that convert the lights they received from the low-resolution displays to the value representing the actual image. In one related case, the low- resolution image is programmed by a value higher than the multiplication of pixels in the zone with higher expected brightness. This provides headroom for correcting the high-resolution image as needed. The low-resolution display can be on for a smaller time than the subframe. The duration can be used to adjust the color point of the display. As the display is lower resolution, changing the duty cycle is more manageable than changing it for the high-resolution monochrome display.

[0061] In another related mode, demonstrated in FIG. 7B, The low-resolution display shows a full-color image at once, and the high-resolution display shows a monochrome image related to the full-color image during each frame. During the first cycle 610, the controller generated two images, one for the full-color low-resolution display and one for the monochrome high- resolution display. During the next cycle 612, the controller programs the two displays withthe related images. During the first cycle, full-color low-resolution and monochrome high- resolution images can be created using different methods. In one method, the more dominant color point of the input image in each zone is picked, and the brightness of the pixels in the low-resolution display associated with each zone is calculated to achieve the color point and allows the pixels in the high-resolution display zone associated with each pixel achieve the brightness associated with the input image. In another related method, the dominant color point is calculated by weighing the color point of each pixel in the zone based on the brightness value. For example, weight is a function of how sensitive the eye is to a color in different brightness. In one related example, the weight of high-brightness or very low-brightness pixels can be lower, and the weight of brightness in certain mid-range can be higher.

[0062] In another related mode, the controllers create more than one color image for low- resolution displays and related monochrome images for high-resolution displays.

[0063] The process is demonstrated in FIG. 7C. During the first cycle 622, the controller divides the input image 600 into a set of sub-images. During the second cycle 624, each subimage generates two images: colored low-resolution and monochrome high-resolution. During the third cycle 626, each subframe shows a color image on the low-resolution color display and a corresponding image on the high-resolution monochrome display. One method of dividing the image into sub-images during cycle 622 is to calculate the first, second and more (if needed) dominant color for each zone. The first dominant color for each zone is used to create the first sub-image, and the second is used to make the second sub-image. The previous techniques can convert the sub-images into high and low-resolution images. In another related method, if a display has three primary colors, a combination of the three colors is used to divide the image into sub-images.

[0064] The following steps describe the details of FIG. 8 using Red, green, and blue (RGB) primary colors as an example.1. Input High-resolution R, G, B image.2. Split the image into patches of size (mxn)3. Calculate the max value for each patch and get the low-resolution R, G, B image to create the low-resolution R, G, B image.4. Based on the color uniformity and structures in the patches, the following cases are used to calculate grayscale values:A. Case 1 : Almost the same uniformity in the patch (more than 95% same pixel value) a. Calculate the ratio between the low-resolution R, G, and B images andcorresponding values; this constant value is updated for the greyscale.5. Case 2: 75 % uniform color in the small region (more than 75 % of the 10x10 region with the same color)A. Optimization is done only for the color with mean square error loss function to calculate the grayscale image values to calculate the grayscale values.6. Case 3: Less than 30% uniform color in the window regionA. Optimization is done only for the color with mean square error and Structural similarity index measure to calculate the grayscale image values to calculate the grayscale values.

[0065] Additional step: Convert the image to HSV color space for better human perception of the calculation.

[0066] Another example of FIG. 8 is as follows, using 10 x 10 reduction in resolution for low- resolution color display.

[0067] Split RGB high-resolution image into multiple windows of smaller sizes (10x10)• Add padding to the border of images to fit the 10x10 regions.• Padding avoids information loss in the image.• Find the maximum pixel value of (RGB) value in the split image region.• Help to reduce the resolution of RGB image.• Also, the maxima region helps to dim the values in the grayscale image to achieve local dimming.• Grayscale image values are based on the following: o Color uniformity in the small window region o Structural uniformity in the small window region o Based on these two parameters, cases are defined to find the grayscale image.

[0068] Case 1:• Almost uniform color in the small window region (more than 95% of the 10x10 region with the same color)• In this case, the ratio between the max pixel value and the window value will be constant (1) in almost all windows.• It can also use mean, median, and mode and compare them with the original pixel value to get the best grayscale value.

[0069] Case 2:o So, the value in the RGB image will be that constant ratio value. o 75 % uniform color in the small window region (more than 75 % of the 10x10 region with same color) o Here, most of the values in the grayscale image will be constant, as 75% of the values in the image are the same. o The remaining values in the grayscale image must be optimized to reduce the error. o As the error is due to color more as the uniformity is more than 75% o Optimization happens to make the color more accurate by preserving the structural similarity. o So, there are three matrices. o Original image window from RGB image of size mxnx3(here 10x10x3) o Corresponding R, G, B value down sampled image of size 1x1x3 o Randomly initialized values in the grayscale image of size 10x10x1 (use other initializations) o The objective function here is the mean square error. o Objective function that calculates the reconstruction error between the original matrix and the product of the 10x10x1 matrix and the 1x1x3 matrix.• Original image window from RGB image of size mxnx3(here 10x10x3)• The reconstructed image is the max values of R, G, and B element-wise multiplied with the initialized grayscale image.• error = np.sum((original_matrix - reconstructed) **2)• error that computes the sum of squared differences (SSE) between the original matrix and the reconstructed matrix.• Error minimization is done to get the optimum gray scale values.• Use L-BFGS-B to solve the method because it allows us to handle bounded optimization.• bounds for optimization are set between 0 and 1 for each element of the 10x10x1 matrix.• The optimization approach will give the best values in the 10x10x1 matrix to minimize the error when multiplying each value with the 1x1x3 matrix, effectively approximating the original 10x10x3 matrix as closely as possible under these constraints.

[0070] Case 3: o Less than 30% uniform color in the small window region (random color and structure 10x10 region with the same color) o Here, we have to consider both the color and structural similarity in the image, o It will define the objective function based on both of them. o Optimize the values in the grayscale image based on these values. o The parameter ionization is the same as like o Original image window from RGB image of size mxnx3(here 10x10x3) o Corresponding R, G, B value down sampled image of size 1x1x3 o o Randomly initialized values in the grayscale image of size 10x10x1 (use other initializations) o The objective function is the combination of two. o Mean square error (MSE) o Structural similarity index measure (SSIM) o MSE will take care of color info, and SSIM will take care of the structural similarity. o mse = np.mean((original_image - new_image) ** 2) o ssim value = ssim(original_image, new image, multichannel=True) o Need to maximize SSIM and minimize MSE o Combination of the loss is mse + (1 - ssim value) o You can also adjust the weighting between these components. o Error minimization is done to get the optimum grey scale values. o Use the L-BFGS-B method to solve the method because it allows us to handle bounded optimization. o bounds for optimization are set between 0 and 1 for each element of the 10x10x1 matrix. o optimization approach will give the best values in the 10x10x1 matrix to minimize the error when multiplying each value with the 1x1x3 matrix, effectively approximating the original 10x10x3 matrix as closely as possible under these constraints.

[0071] In one related embodiment, the full color low-resolution display is larger than the monochrome display. The low-resolution part is around the edge of the image. This pattern follows the human eye characteristics, a high-resolution image formed at the center by thecombination of monochrome and full color emissive display, and low-resolution image is on the edge formed by the full color display only.System and Method Embodiments

[0072] One embodiment of the invention discloses a display system (or a method) to comprising of a front plane enabled of modulating lights to create images, a back light unit for generating lights and colors, wherein the back light unit has an array of multiple zones wherein each zone has at least two different types of devices generating different light wavelengths and each zone can generate different brightness and different colors based on a front plane image, the front plane aligned with the back light unit, and the front plane and the back light unit bonded together with a fixed distance.

[0073] The system further comprises the front plane being updated in a frame, where each frame comprises a pixel information created by a pixel, wherein further, the array of multiple zones are also updated with data based on a maximum value of each sub-pixel brightness associated with each back light zone, wherein further, the array of multiple zones turn off where the pixels associated with each zone are being updated in the front plane.

[0074] The system further comprises, wherein the front plane has one sub-pixel per pixel with no color filter, wherein each frame is divided into more than one subframe, and each subframe is associated with a specific color, wherein further, the front plane pixels are updated with a color data of an image related to each subframe, wherein further, the array of multiple zones are programmed to generate a similar color as associated with each subframe and each zone, wherein further, each back light zone is programmed to control a brightness based on a pixel data in that subframe, wherein further, the back light zone in the t array of multiple zones, turns off while a pixel associated with that zone is being updated. Here, there is a low power mode such that at least one subframe creates a complex color comprising a color from two devices in the back light.

[0075] The system further shows in FIG. 5 an embodiment that permits a higher frame rate. Here, several rows are programmed at the same time using separate data lines. In one related embodiment, the select lines that enable the pixels to capture the data from the data lines (DATA) are activated simultaneously for the several rows being programmed simultaneously. Here, the select lines (SEL) are connected to one source or have different simultaneously programmed sources. The select lines (SEL) can also be shared between the rows that are being programmed simultaneously. In one example, each column has three data lines (DATA[j, 1 :3]). Each data line is connected to a pixel in a different row. The select lines (SEL) associatedwith a pixel set connected to these data lines are activated simultaneously, allowing pixels in different rows to be programmed simultaneously. The rows programmed simultaneously can be adjacent or spread in different parts of the arrays. The rows in the array are divided into multiple sets, and each set is programmed simultaneously.

[0076] In one related embodiment, the low-resolution image created by the back light has fullcolor information and brightness. The front plane light modulation element improves the resolutions by modulating the brightness of the areas in each pixel associated with the lower- resolution image. Here, the front plane has no color filter, so color definition only comes from the back light. Furthermore, running the front plane at a higher frame rate is unnecessary.

[0077] Also, since the back light and front plane are synched, the frame rate can be adjusted without any challenges associated with the color sequential effect at low frame rates.

[0078] In another related embodiment, the display can have high image quality and low power modes. In high-quality mode, where the color sequential is used, each subframe creates a low resolution of a single color in the back light and an associated high-resolution image in the front plane. The display has one frame during the low power mode, and the back light has fullcolor information and low pixel resolution. The high-resolution image created in the front plane only modulates the brightness.

[0079] In another related embodiment, there is more than one subframe. A full-color image is created in the back light during each subframe, and the front plane light modulation element (LME) is programmed to enhance the image resolution. The first image is created using back light full color and front monochrome LME. The error between the created and actual images is calculated, and a second image is created using back light and front plane LME to reduce the error to a preset value. The first and second images are shown during two different sub-frames. There can be a 3rd image and a 3rd subframe to reduce the error between the created and actual images.

[0080] In another related embodiment, the first image is created to limit the sub-pixel brightness error for each pixel within a threshold boundary. The threshold boundaries can have an upper limit and a lower limit. The second image is also created based on the difference between the created and actual images to reduce the error further. This process can extend to more than the first and second images.

[0081] In one related embodiment, the subframes and images created for each subframe can be transitional between two actual images. Here, the second or third subframe can have information from the first and second images, which can be interpolation data between the two actual images.

[0082] While particular embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise construction and compositions disclosed herein and that various modifications, changes, and variations can be apparent from the foregoing descriptions without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A display system comprising: a frontplane enabled to modulate lights to create images; a back light unit for generating lights and colors, wherein the back light unit has an array of multiple zones, wherein each zone has at least two different types of microdevices generating different light wavelengths, and each zone can generate different brightness and different colors based on a frontplane image; the front plane aligned with the back light unit; and the frontplane and the back light unit bonded together with a fixed distance.

2. The system of claim 1, wherein the frontplane is updated in a frame, where each frame comprises a pixel information created by a pixel, wherein further, the array of multiple zones is also updated with data based on a maximum value of each sub-pixel brightness associated with each back light zone, wherein further, the array of multiple zones turns off where the pixels associated with each zone are being updated in the frontplane.

3. The system of claim 1, wherein the frontplane has one sub-pixel per pixel with no color filter, wherein each frame is divided into more than one subframe, and each subframe is associated with a specific color, wherein further, the frontplane pixels are updated with a color data of an image related to each subframe, wherein further, the array of multiple zones are programmed to generate a similar color as associated with each subframe and each zone, wherein further, each back light zone is programmed to control a brightness based on a pixel data in that subframe, wherein further, the back light zone in the t array of multiple zones, turns off while a pixel associated with that zone is being updated.

4. The system of claim 3, wherein there is a low power mode such that at least one subframe creates a complex color comprising a color from two devices in the backlight.

5. The system of claim 1, wherein more than one row is programmed simultaneously to allow a higher frame rate.

6. The system of claim 5, wherein there are separate data lines for each row programmed simultaneously.

7. The system of claim 5, wherein select lines for the rows being simultaneously are activated together.

8. The system of claim 5, wherein the select lines are connected to a similar source.

9. The system of claim 5, wherein the select lines are shared simultaneously between the rows being programmed.

10. A display with a full-color back light array and frontplane monochrome light modulating array having a low power mode, wherein the back light array creates a full color and the monochrome frontplane light modulating array improves image resolution.

11. The display of claim 10, wherein there is an image quality mode that runs multiple subframes and each subframe has a full-color back light image and a monochrome frontplane image and a sum of the images in each subframe creates a first image close to an actual image.

12. The display of claim 11, where a second image is generated to reduce an error between the first image and the actual image.

13. The display of claim 11, wherein there is a threshold boundary, limiting the error between the first image and the actual image with upper and lower threshold values for subpixels.

14. A display system comprising: a frontplane with no color filter; a backlight configured to give color definition; and a front plane light modulation element enabled to improve the resolution by modulating brightness of areas in each pixel associated with a lower resolution image, wherein the backlight and frontplane are synched and a frame rate is adjusted without any risks associated with color sequential effect at low frame rates.

Images