CN101568955A - Method of determining luminance values for a backlight of an LCD panel displaying an image - Google Patents
Method of determining luminance values for a backlight of an LCD panel displaying an image Download PDFInfo
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- 238000005286 illumination Methods 0.000 claims abstract description 25
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
- G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
- G09G3/3426—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines the different display panel areas being distributed in two dimensions, e.g. matrix
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/06—Adjustment of display parameters
- G09G2320/0626—Adjustment of display parameters for control of overall brightness
- G09G2320/0633—Adjustment of display parameters for control of overall brightness by amplitude modulation of the brightness of the illumination source
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2360/00—Aspects of the architecture of display systems
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Abstract
A controller for a backlight for a LCD panel has at least two methods for determining an illumination value for the backlight. The controller selects between the two methods based on properties of the image being displayed. The properties of the image include its color and its intensity.
Description
Technical field
The present invention relates to a kind of method of backlight brightness values of LCD panel of definite display image.The present invention also relates to a back light apparatus, be used to provide the LCD panel of giving a display video image backlight, determine backlight brightness values according to video image according to this method.
Background of invention
LCD (LCD) panel is not a light emitting device.Be applied to the transmittance that voltage on the LCD panel can change liquid crystal cell in the panel (pixel).The LCD panel can be reflective, thereby the image that produces on panel can be watched by reflection of ambient light.But, also inapplicable to the LCD panel of large scale or high-contrast.
In the time of in being used for such as TV, graphoscope and hand-hold electronic equipments application, the LCD panel is from behind backlight and illuminated.In great majority were used, backlight was an even and constant light output, and the variation in the brightness of display image is to control by the transmittance that changes liquid crystal cell in the display pannel.In order to produce good visuality in higher ambient light, backlight must have a higher brightness or intensity rank.Many shortcomings are arranged in this respect, comprise that high energy consumption and generation are overheated.Another shortcoming of constant backlight is its limited dynamic contrast that causes LCD display, light leak (1ightleakage) occurs because pass the meeting backlight of LCD panel when pixel is in dark or closed condition.Light leak causes than dark areas a grey performance being arranged, rather than the performance of a complete black.
A kind of technology that is intended to improve the dynamic range of LCD display is to adjust entire backlight brightness according to the luminance dynamic ground of video image.If image is relative higher brightness, backlight control is moved light source on higher brightness so.If dark images dims output backlight so to reduce light leak, make the image deepening.An advantage of this backlight technology is to reduce energy consumption backlight.Although this technology can be improved the LCD contrast range, and save energy consumption backlight a little, it may cause image fault, and causes the brightness of image fluctuation.
Summary of the invention
So, the purpose of this invention is to provide a back light apparatus and be used to provide backlightly to panel of LCD and a kind of method of controlling panel of LCD brightness, it can overcome or alleviate the problems referred to above.
Disclosed a control method that the LCD panel is backlight at this, it has at least two methods to determine the back lighting value.Controller based on shown in the feature of image between these two methods, select.Preferably, characteristics of image comprises its color and brightness.If color is lower than first threshold or brightness is higher than second threshold value, then selects first method, otherwise select second method.If select first method, then illumination value is based on a brightness peak of image.If select second method, then illumination value is based on an average brightness value of image.
Preferably, the present invention is embodied in one and has in a plurality of independent controllable lightings district backlight.Nominally image is divided into a plurality of image blocks, the corresponding back lighting district of each image block.A kind of method of illumination value of definite each back lighting district comprises: whether the number of pixels n that determines the correspondence image piece satisfies specific criteria, if n is individual or more pixels satisfy standard, then use first method to determine the back lighting value, otherwise use second method to determine the back lighting value.Preferably, standard is color and brightness.To the pixel of n at least in the image block, determine a color saturation value and a brightness value, if and wherein n color of pixel saturation value is lower than first threshold, perhaps the brightness value of n pixel is higher than second threshold value, then use first method to determine illumination value, otherwise use second method to determine brightness value.
In a preferred embodiment of the present invention, determine that the first method of illumination value is based on the luma value of image block interior pixel, and determine that the second method of illumination value is based on redness, green and the blue color value of image block interior pixel.
From the description below in conjunction with example, others of the present invention will be obvious all the more.
Description of drawings
Now, exemplary embodiments of the present invention will be described in conjunction with example and with reference to accompanying drawing, wherein:
Fig. 1 is a total synoptic diagram of implementing the LCD TV of the inventive method and device;
Fig. 2 describes the image that will watch on LCD TV;
Fig. 3 and 4 is two subgraphs or the image block A in Fig. 2 image, B;
Fig. 5-the 10th, the exemplary image of the backlight color of the definite LCD TV of description and the first method of brightness;
Figure 11-the 16th, the exemplary image of the backlight color of the definite LCD TV of description and the second method of brightness; With
Figure 17 is a process flow diagram of determining the adaptive approach of backlight color and brightness according to the present invention.
Exemplary embodiments is described
Now in detail with reference to an exemplary embodiments of the present invention, its example will be described in accompanying drawing, and wherein identical reference number is represented components identical.
Described exemplary embodiments is described the present invention and is embodied in the backlight LCD display, and as LCDTV, it is used to show and comprises a plurality of video images of successive frames that each successive frame is made up of a plurality of pixels.This is not to be intended to limit usable range of the present invention or function.The enhancing still image that the present invention is equally applicable to show on lcd screen.For example, many companies, advertiser or artist use lcd screen to show static but periodically variable information, advertisement and/or art picture and image.The present invention can be used to strengthen the performance on screen of this information, advertisement and/or image equally.
Equally, to be embodied in the backlight LCD display be not to be intended to limit usable range of the present invention or function in the present invention.The present invention can be embodied in any display equipment equally, and it uses a light source that image projection to a projection surface or one are used on the flat pannel display face of the direct viewing that comes display image backlight.This display comprises digital micromirror device display (DMDs), liquid crystal on silicon (LCoS) display and LCD display.
11/707,517 li of U.S. Patent application in early days, its content is incorporated into this paper by reference, and the applicant has described one and has had LCD display equipment backlight, a plurality of independent controllable lightings district that is divided into backlight.The brightness of each surround is to control according to the vision signal feature of LCD display corresponding region.If shown in image-region become clear, or a higher brightness is arranged, then there is higher brightness in Dui Ying back lighting district, if image-region is dark, then Dui Ying back lighting district is not or have lower brightness.By according to shown in the feature of a counterpart of image dynamically control the brightness in each back lighting district, the contrast and the dynamic range of image shown in can improving.In addition, each independent controlled back lighting district can comprise variable-colour light source, as a group controlled redness, green and blueness (RGB) LED separately, thereby the color that can control the surround from the black of chromatogram to white.Backlight illumination and color can according to shown in the feature of a counterpart of image dynamically control, thereby improve contrast and color dynamic range.
In U.S. Patent application 11/707,517, LED backlight is control separately, so backlight illumination is not unified, can change along with image.Another advantage of this system is that entire backlight brightness is darker than existing constant backlight system usually.This is that it may have identical brightness with existing constant backlight system usually because the light color of display image or the backlight of zone of higher brightness will be in its maximal value, but most of image has lower brightness, and therefore meeting backlight is darker.As a result, compare with existing constant backlight, or with entire backlight based on shown in the brightness of image feature compared by unified dimming dynamically, what have a plurality of independent controllable lightings district backlightly has on average a more low energy consumption.
With reference to Fig. 1, show total synoptic diagram of a backlight LCD display, as the LCD TV type of in U.S. Patent application 11/707,517, discussing.Display comprises a LCD panel 1 that is positioned at 2 front ends backlight.Backlight 2 are divided into the controlled field of illumination of a plurality of independences.In described embodiment,, have only for ease of describing
Individual zone.In the preferred embodiments of the present invention, each zone comprises one group of redness 3, green 4 and blue 5LED, thereby the output of the light in zone can be that black from chromatogram is to white.But optional for the purpose of the present invention, in other embodiment, district backlight can include only White LED or other light source.Nominally LCD panel rather than physically be divided into a plurality of viewing areas 6.TV converter 7 receives picture signal by the analog or digital interface from various video source such as PC, DVD player, wired TV etc.After handling input signal, the TV converter produces the vision signal 8 of rgb format, and transmits 8 to brightness controllers 9 of vision signal.Brightness controller 9 is analyzed incoming video signal 8, and the led driver of drive signal 10 to 2 each surround backlight is provided.LED drive signal 10 comprises that color and monochrome information give each surround of backlight 2.In order to optimize backlight dimming, and then save energy consumption, keep simultaneously or maximization picture contrast and quality, use a kind of methods analyst LCD picture signal 8, determine the drive signal 10 of LED.The method that selection is used for analyzing LCD picture signal 8 is to determine adaptively according to the pixel characteristic in each image block that takies the viewing area.
Fig. 2 shows an image that shows on LCD panel 1.For the ease of the purpose of duplicating, all images is all by gray level display, but is actually the color image of rgb format.Can see that the image major part is uniform color, have only the central left half of image to have the feature of regions of different colours, compare with the main color of image and have a higher contrast ratio.Show grid above the image of Fig. 2, each image block in grid is represented a nominal piece of corresponding LCD panel 1, and a surround that independence is controlled of corresponding backlight 2.Based on the characteristics of image of image block, be independent controlled aspect color and the light intensity (brightness) in the district backlight of each image block back.Fig. 3 and 4 is respectively the enlarged drawing of image block A and B.Can find that color of image is uniformly substantially in piece B in whole, yet color of image is uniformly substantially in piece A, except two whites or light point in the upper left corner, top.Piece A can cause different problems with B when selecting a suitable backlight color with brightness.In the present invention, can use various criterion to analyze this different masses, so that obtain best final picture quality.Reason and the method for determining appropriate criteria are described hereinafter.
Known as those skilled in the art, the RGB picture signal has three passages, promptly red, green and blue, it can be counted as three overlapping gray level images, separately the brightness value of corresponding red, the green and blue color part of each pixel in the memory image.Brightness value is represented by a n-bit integer.To a common 8-bit image, integer range be from 0 in 255.The corresponding color of pixel of this value of 0 value representation partly is " pass ".The corresponding color of pixel of this value of 255 value representations partly is high-high brightness ground " opening ".The first method of determining led color backlight and brightness is to find out the average brightness value of each Color Channel interior pixel.Image block is divided into redness, green and blue Color Channel, and the brightness value of all pixels adds up in each passage, then divided by the number of pixels in this channel image piece to find out average brightness value.Red, the green and blue mean flow rate of each color part in this display image piece.Each surround backlight is the cohort illumination by redness, green and blue led, thereby district backlight can provide the correspondence image piece of image shown in coloured backlight the arriving.Three average brightness values are used to determine the drive signal value of each redness, green and blue led in the corresponding surround of back light apparatus.The backlight color and the brightness of expectation are three mean values.Because the drive signal scope of each LED may not corresponding drive signal scope, average can be in addition by standardization.
Fig. 5 and 8 is gray scale displaying blocks, backlight color and the brightness of expression when determining according to above method.Each Color Channel average brightness value of Fig. 3 piece A and Fig. 4 piece B is R=155, G=217, B=158 and R=151, G=216, B=123.Account for the number percent of high-high brightness 255 by the mean value of finding out three channel value, can estimate the shared number percent of backlight power.To Fig. 5, be ((155+217+158)/3)/255 or approximate 70%.To Fig. 8, approximate is 64%.The higher-wattage of Fig. 5 module is to be caused by two on image apex left corner light color points.Fig. 6, the 7 and 9, the 10th, gray scale is represented, describes the effect of determining backlight color and brightness by the RGB Mean Method.Fig. 6 and 9 shows the scene that the initial pictures piece will be seen when respectively by Fig. 5 and 8 colors that show and brightness back lighting on LCD display.Fig. 7 and 10 is initial pictures, is used for comparison.Can find easily that in Fig. 6 the brightness and contrast of two light color points on the left corner of top reduces because of effect backlight.Because reduce backlight illumination to 70%,, but need pay the cost of picture quality and contrast so can realize energy-conservationly.Compare with Fig. 9, can find that image is not changed,, thereby can realize energy-conservationly, and can not reduce picture quality even may make moderate progress because backlightly dim even strengthen to some extent.So, determine that the RGB Mean Method of backlight color and brightness is suitable for the parts of images of similar B, but be not suitable for having the parts of images of the piece category-A type of high-contrast.
The second method of determining LED brightness backlight is a Y-peak method.In the YUV color model, the colouring information of an image and luma unpack.Luma is meant brightness of image, i.e. the black of image or whiteness.The data of each pixel have three integer representations.First or the Y integer be luma or brightness part, and second and the 3rd or U and V integer be colourity or color part.In the Y-peak method, the RGB image block is converted into the YUV color space, and the LED drive signal is based on the peak value Y of all pixels in the image block.Same drive signal is used to all redness, green and blue led, thereby corresponding back lighting district does not have color, only its brightness of control in white light.Figure 11 and 14 is gray scale displaying blocks, shows the backlight illumination of image block A and B when determining according to the Y-peak method respectively.To Figure 11, the light color point has maximum brightness, thus the high-high brightness that approximate 100% power is arranged backlight.To Figure 14, the chances are 84% for power.Figure 12, the 13 and 15, the 16th, gray scale is represented, describes the effect of determining backlight illumination by the Y-peak method.Figure 12 and 15 describes the scene that how the initial pictures piece is seen when the backlight illumination back lighting that is shown by Figure 11 and 14 respectively on LCD display.Figure 13 and 16 is initial pictures pieces, with making comparisons.Can see easily that at Figure 12,13 and 15,16 image does not change, because backlight illumination that the method is calculated even enhancing to some extent.But backlight illumination and power ratio are higher by the RGB Mean Method, so, though keep picture contrast and quality, energy consumption increased.
Therefore, in the present invention, adopt a self-adaptation to dim scheme,, select RGB Mean Method or Y peak method to determine the backlight color and/or the brightness of each surround backlight according to the feature of the nominal image block of surround illumination.In adaptation scheme, if the light color in the image block or the number of high luminance pixel exceed a predetermined threshold T3, then use the Y-peak method to determine backlight illumination, otherwise use the RGB Mean Method that image block.
A light pixel is pixel white or that have less color and approaching white.If color saturation or colorfulness are lower than threshold value T1, pixel is classified into light color.Each pixel is to be represented the brightness of its redness, green and blue portion by three n-bit integer.In the present invention, by with the difference between the minimum and maximum brightness value divided by three brightness values and, determine a color of pixel saturation degree, specifically shown in following equation:
Minimum color saturation is at a white pixel, and wherein all three redness, green and blue brightness value equate, thereby the molecule in the above equation is 0.Therefore, be 0 to a white pixel s.The maximum color saturation degree is that it only comprises a main color, is 255: 0: 0 as rgb value at such pixel, thereby s is 1.In the preferred embodiments of the present invention, threshold value T1 is 0.1, if therefore s is lower than 0.1, then pixel is counted as light.Determine whether pixel is that light color saturation method is not to be intended to limit usable range of the present invention or function.The technician can understand, this be a definite pixel color and pixel whether be the method for light color, other same effective method also is suitable for.For example, pixel transitions can be become the YUV color space, and partly determine color from U and V.
If definite brightness value of a pixel is higher than the second threshold value T2, this pixel is classified has high brightness.In the preferred embodiments of the present invention, the brightness value of a pixel is the average of two highest brightness value of pixel.So, have RGB brightness value such as R=150 at one, G=250, in the pixel of B=180, brightness value is 215 (i.e. (250+180)/2).In context of the present invention, height is a relative terms, and whether pixel has the brightness that high brightness depends on other pixel in image or the image block.In order to consider this situation, in the preferred embodiments of the present invention, the second threshold value T2 is a dynamic value, equals the image of evaluated pixel or the mean flow rate of all pixels in the image block.If the average of interior two the RGB brightness values the highest of pixel is higher than the average brightness of all pixels in the image block, then this pixel is counted as having a high brightness.The method whether this definite pixel has high brightness is not to be intended to limit usable range of the present invention or function.The technician can understand, and this is whether a definite pixel has the method for high brightness, and other method also is feasible.For example, a simple method is the mean flow rate of three RGB brightness values of comparison and the predetermined value of a 0-255 brightness range, such as 200.
Figure 17 is the process flow diagram that self-adaptation dims scheme, is used for determining which scheme should be used to determine a feature suitable backlight that the surround is backlight from the image block feature of correspondence.At first, when 20 li of preparation module were called decision-making module, two variable i and n were set to 0.Variable i is represented current evaluated image pixel, and variable n is a counter, is used to the number of interior light color of document image piece and high luminance pixel.Advance to processing module 21, pixel counter i is increased progressively by 1, and present analysis is to carry out on the number of pixels 1 in current image block.Advance to processing module 22, this of this method step is to calculate the color saturation of current pixel i, is represented by s.At decision-making module 23, color saturation s and first threshold T1 compare.If color saturation is lower than threshold value T1, be categorized as light pixel, this method advances to next step processing module 24, otherwise this method turns back to processing module 21, pursues 1 and increases progressively pixel counter, and to the next pixel repetitive process 22 in the image block.
In processing module 24, calculate the RGB average of current pixel i, represent by a.By picture element signal is divided into single redness, green and blue channel, determines the color value of each passage, each value of suing for peace and with summation divided by 3 (Color Channel numbers), can determine the RGB average.At decision-making module 24, the RGB average a and the second threshold value T2 compare.If value a is higher than threshold value T2, be categorized as high luminance pixel, this method advances to processing module 26 then, otherwise it turns back to processing module 21, by 1 value that increases progressively pixel counter i, and repeating step.
In processing module 26, this method count-up counter n, the number of light color and high luminance pixel promptly has one and is lower than the color saturation s of T1 and the pixel of a RGB average that is higher than T2 in its recording picture module.This method advances to decision-making module 27, the maximum number i-max of its compared pixels counter i and image block interior pixel.If pixel counter i does not also reach maximal value, mean that not every pixel is all analyzed in the module, this method turns back to processing module 21, and it increases progressively pixel counter i, and continues always.
If pixel counter i has reached max pixel value, then do not have pixel to be used for analyzing, thereby process proceed to decision-making module 28, it is counter n and the 3rd threshold value T3 relatively.If n is greater than threshold value T3, the number of pixels of light color and high brightness has exceeded threshold value in the display image piece, and the present invention advances to processing module 29, and it calls the Y-peak method and determines backlight color and brightness.If counter n is lower than threshold value T3, this method advances to processing module 30, and it calls the RGB Mean Method and determines backlight color and brightness.
Therefore, according to the present invention, use a self-adaptation solution method to determine the method for backlight color and brightness, thereby can select optimal colors and brightness for each district backlight backlight from the single pixel characteristic in the image block.Can produce the best solution of picture quality and saving energy consumption like this.
Claims (16)
1. method backlight of controlling the LCD panel of display video image, video image comprises a plurality of picture frames, controller has at least two methods and be used for determining the back lighting value that wherein this method comprises: the feature based on picture frame is selected between at least two method.
2. method according to claim 1 wherein selects to be based on the feature of picture frame between at least two methods, and is recycled and reused for each picture frame in the video image.
3. method according to claim 1, wherein characteristics of image comprises color and brightness.
4. method according to claim 3 if wherein color is lower than first threshold or brightness is higher than second threshold value, is then selected first method, otherwise selects second method.
5. method according to claim 1 if wherein select first method, determines that then illumination value is based on a brightness peak of image, and if the selection second method determines that then illumination value is based on an average brightness value of image.
6. the method for the back lighting value of the LCD panel of a definite display image, the surround that comprises that a plurality of independences are controlled backlight, nominally and image is divided into a plurality of image blocks, the corresponding back lighting district of each image block, image block comprises that a plurality of image slices have pixel color and brightness, this method comprises whether n the pixel of determining in the image block satisfies a standard, if n is individual or more pixels satisfy this standard, then use first method to determine the back lighting value of correspondence image piece, otherwise use second method to determine the back lighting value of correspondence image piece.
7. method according to claim 6, wherein this method comprises and determines in the image block at least n color of pixel value and/or brightness value, if and wherein n color of pixel value brightness value of being lower than first threshold or n pixel is higher than second threshold value, then use first method to determine illumination value, otherwise use second method to determine illumination value.
8. method according to claim 7 wherein selects first threshold to determine whether pixel is light.
9. method according to claim 7 wherein selects second threshold value to determine whether pixel has a high brightness.
10. method according to claim 7, wherein each pixel has redness, green and blue brightness value, selects second threshold value to determine whether the mean value of any two values in described redness, green and the blue brightness value surpasses second threshold value.
11. method according to claim 9, wherein second threshold value is a mean flow rate of all pixels in the image block.
12. method according to claim 7, wherein first threshold is 10% of a maximum color value.
13. method according to claim 7, wherein first threshold be set at a maximum color value 5% to 30% between.
14., be used for wherein determining that the first method of illumination value is based on the luma value of image block interior pixel according to claim 1 or 6 described methods.
15., be used for wherein determining that the second method of illumination value is based on redness, green and the blue color value of image block interior pixel according to claim 1 or 6 described methods.
16. a back light apparatus is used to provide the LCD panel to a display video image backlight, it determines the back lighting value according to claim 1 or 6 described methods.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| PCT/CN2008/070096 WO2009089686A1 (en) | 2008-01-14 | 2008-01-14 | Method of determining luminance values for a backlight of an lcd panel displaying an image |
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| CN101568955A true CN101568955A (en) | 2009-10-28 |
| CN101568955B CN101568955B (en) | 2012-12-12 |
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| CN101808209A (en) * | 2010-03-09 | 2010-08-18 | 四川维优科技有限责任公司 | Method and circuit for dynamically modulating digital brightness of time sequence LCOS minisize projector |
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| GB201114771D0 (en) * | 2011-08-26 | 2011-10-12 | Bae Systems Plc | A display |
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| CN100410994C (en) * | 2001-11-02 | 2008-08-13 | 夏普株式会社 | Image display apparatus |
| KR100570966B1 (en) * | 2003-11-17 | 2006-04-14 | 엘지.필립스 엘시디 주식회사 | Driving Method and Driving Device of Liquid Crystal Display |
| US20070171325A1 (en) * | 2006-01-20 | 2007-07-26 | Byung-Soo Ko | Light Management Film Package For Display Systems and Systems Using Same |
| CN100542236C (en) * | 2006-07-03 | 2009-09-16 | 深圳Tcl工业研究院有限公司 | Brightness adjusting method of LCD TV backlight |
| JP2008021420A (en) * | 2006-07-10 | 2008-01-31 | Minebea Co Ltd | Planar illumination device |
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| CN101808209A (en) * | 2010-03-09 | 2010-08-18 | 四川维优科技有限责任公司 | Method and circuit for dynamically modulating digital brightness of time sequence LCOS minisize projector |
| CN101808209B (en) * | 2010-03-09 | 2012-08-15 | 四川维优科技有限责任公司 | Method and circuit for dynamically modulating digital brightness of time sequence LCOS minisize projector |
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| CN101568955B (en) | 2012-12-12 |
| WO2009089686A1 (en) | 2009-07-23 |
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