METHOD AND SYSTEM FOR OPERATING AN ACTIVE DISPLAY

Abstract

Please replace the originally filed abstract with the abstract provided below: A method for operating a display comprising providing a first feed of a first sequence of image data and providing a second feed of a second sequence of image data, the second feed comprising a second sequence of image data and a second complementary sequence of image data. The display is operated at a high display frame rate (HDFR) comprising HDFR image slots/slices during a standard frame rate (SFR) time interval. The method includes displaying the first feed and the second feed in a time-sliced multiplexed manner in the HDFR image slots of each SFR time interval. The first feed and the second feed comprise gray images obtained from the combination of image data presented at equal luminance and being evenly distributed within the HDFR image slots so the luminance changes of the display occur at frequencies greater than or equal to twice the SFR.

Claims

1-16. (canceled)

17. A method for operating an active display comprising an array of active light-emitting elements, said method comprising the steps of: providing a first feed of a first sequence of image data (F0.sub.k) intended to be seen by direct viewers; providing at least one second feed of a second sequence of image data (F1.sub.k,C1.sub.k; F2.sub.k,C2.sub.k; F3.sub.k,C3.sub.k) not intended to be seen by said direct viewers, said at least second feed comprising a second sequence of image data (F1.sub.k; F2.sub.k; F3.sub.k) and a second complementary sequence of image data (C1.sub.k; C2.sub.k; C3.sub.k) consisting of inverse/complementary image data to said second sequence of image data such that the combination of each image (F1.sub.k and C1.sub.k; F2.sub.k and C2.sub.k;F3.sub.k and C3.sub.k) results in homogenous gray images; selecting a standard frame rate (SFR) at which said first and said at least second sequences of image data are presented on said active display; operating the active display at a high display frame rate (HDFR) comprising nd HDFR image slots/slices during a standard frame rate time interval ?T=1/SFR of said standard frame rate (SFR), each HDFR image slot having a duration ?.sub.i with $\underset{i=1}{\overset{\mathrm{nd}}{.Math.}}{?}_i=?T=\frac{1}{\mathrm{SFR}};$ presenting said image data of said first feed and said at least second feed in a time-sliced multiplexed manner on said active display in said nd HDFR image slots of each standard frame rate time interval, wherein the time-integrated luminance of said first sequence of image data presented during a standard frame rate time interval is higher than the sum of the time-integrated luminances of said second sequences of image data; wherein at least two feeds of said first feed and said at least one second feed comprise said gray images obtained from said combination of image data and complementary image data (F1.sub.k and C1.sub.k; F2.sub.k and C2.sub.k; F3.sub.k and C3.sub.k), said gray images being presented at equal luminance on said active display and being evenly distributed within said nd HDFR image slots in such a manner that luminance changes of said active display occur at frequencies greater than or equal to twice said standard frame rate (SFR); wherein: said first feed of said first sequence of image data (F0.sub.k) further comprises a first complementary sequence of image data (C0.sub.k) consisting of inverse/complementary image data to said first sequence of image data such that the combination of each image (F0.sub.k and C0.sub.k) results in homogenous gray images, and said gray images of said at least two feeds comprise gray images from said first feed (F0.sub.k and C0.sub.k) and gray images from said second feed (F1.sub.k and C1.sub.k), wherein at least one of the nd HDFR image slots shows a regular representation of the first sequence of image data at a first luminance, one of the ad HDFR image slots shows a representation of the second sequence of image data, one of the nd HDFR image slots shows a representation of the second complementary sequence of image data, one of the nd HDFR image slots shows a representation of the first sequence of image data at a luminance lower than the first luminance and one of the nd HDFR image slots shows a representation of the first complementary sequence of image data at a luminance lower than the first luminance.

18. The method of claim 17, wherein said luminance changes of said active display occur at frequencies greater than 100 Hz.

19. The method of claim 17, wherein each pair (F0.sub.k,C0.sub.k; F1.sub.k,C1.sub.k; F2.sub.k,C2.sub.k; F3.sub.k,C3.sub.k) of images of said at second sequence of image data (F1.sub.k; F2.sub.k; F3.sub.k) and inverse/complementary images of said second complementary sequence of image data (C1.sub.k; C2.sub.k; C3.sub.k) are presented within a time interval of 3.3 ms or less.

20. The method of claim 17, wherein said nd HDFR slots of a standard frame rate time interval ?T have the same length ?.

21. The method of claim 17, wherein said nd HDFR slots of a standard frame rate time interval ?T have variable lengths ?.sub.i.

22. The method of claim 17, wherein lengths ?.sub.i, ? of each of said nd HDFR slots are generated via a pulse counter fed by a G-clock (GCLK).

23. The method of claim 22, wherein different durations r, of said HDFR image slots are be obtained by changing the frequency of the G-clock (GCLK) while counting the same predetermined number of pulses via said pulse counter.

24. The method of claim 17, wherein at least one of said nd HDFR image slots comprises a black phase having a duration which is shorter than a duration Ti of the respective HDFR image slot.

25. The method of claim 24, wherein the duration of the black phase is shorter than 20% of the duration of said nd HDFR image slot.

26. The method of claim 17, wherein at least six HDFR image slots are provided during a standard frame rate time interval ?T=1/SFR.

27. The method of claim 17, wherein HDFR image slots presenting images of said at least second complementary sequence of image data (C1.sub.k; C2.sub.k; C3.sub.k) also comprise image data of said first sequence of image data (F0.sub.k).

28. The method of claim 27, comprising operating said active light-emitting elements of said active display an increased electrical current while reducing the luminance of the complementary image component proportionally.

29. The method of claim 27, wherein said HDFR image slots presenting images of said at least second complementary sequence of image data (C1.sub.k; C2.sub.k; C3.sub.k) comprise image components of the immediately preceding and immediately the following HDFR image slot.

30. The method of claim 17, wherein said active display is an LED or OLED display.

31. A system for operating an active display comprising an array of active light-emitting elements, said system comprising a control unit configured to perform the method of one of claim 17.

32. A method for operating an active display, the method comprising the steps of: providing a first feed of a first sequence of image data (F0.sub.k) intended to be seen by direct viewers; providing a second feed of a second sequence of image data (F1.sub.k,C1.sub.k; F2.sub.k,C2.sub.k; F3.sub.k,C3.sub.k) not intended to be seen by the direct viewers, the second feed comprising a second sequence of image data (F1.sub.k; F2.sub.k; F3.sub.k) and a second complementary sequence of image data (C1.sub.k; C2.sub.k; C3.sub.k), the combination of each image (F1.sub.k and C1.sub.k; F2.sub.k and C2.sub.k;F3.sub.k and C3.sub.k) resulting in homogenous gray images; selecting a standard frame rate (SFR) at which the first and the at least second sequences of image data are presented on the active display; operating the active display at a high display frame rate (HDFR) comprising HDFR image slices during a standard frame rate time interval of the standard frame rate (SFR), each HDFR image slot having a duration, the sum of HDFR image slots equal to the standard frame rate time interval; presenting the image data of the first feed and the at least second feed in a time-sliced multiplexed manner on the active display in the HDFR image slots of each standard frame rate time interval, wherein the time-integrated luminance of the first sequence of image data presented during a standard frame rate time interval is higher than the sum of the time-integrated luminances of the second sequences of image data; wherein at least two feeds of the first feed and the at least one second feed comprise the gray images obtained from the combination of image data and complementary image data (F1.sub.k and C1.sub.k; F2.sub.k and C2.sub.k; F3.sub.k and C3.sub.k), the gray images being presented at equal luminance on the active display and being evenly distributed within the HDFR image slots in such a manner that luminance changes of the active display occur at frequencies greater than or equal to twice the standard frame rate (SFR); wherein: the first feed of the first sequence of image data (F0.sub.k) further comprises a first complementary sequence of image data (C0.sub.k) consisting of inverse/complementary image data to the first sequence of image data such that the combination of each image (F0.sub.k and C0.sub.k) results in homogenous gray images, and the gray images of the at least two feeds comprise gray images from the first feed (F0.sub.k and CO.sub.k) and gray images from the second feed (F1.sub.k and C1.sub.k), wherein at least one of the HDFR image slots shows a regular representation of the first sequence of image data at a first luminance, one of the HDFR image slots shows a representation of the second sequence of image data, one of the HDFR image slots shows a representation of the second complementary sequence of image data, one of the HDFR image slots shows a representation of the first sequence of image data at a luminance lower than the first luminance and one of the HDFR image slots shows a representation of the first complementary sequence of image data at a luminance lower than the first luminance.

33. A method for operating a display comprising the steps of: providing a first feed of a first sequence of image data (F0.sub.k) and providing a second feed of a second sequence of image data (F1.sub.k,C1.sub.k; F2.sub.k,C2.sub.k; F3.sub.k,C3.sub.k), the second feed comprising a second sequence of image data (F1.sub.k; F2.sub.k; F3.sub.k) and a second complementary sequence of image data (C1.sub.k; C2.sub.k; C3.sub.k), the combination of each image (F1.sub.k and C Lk; F2.sub.k and C2.sub.k; F3.sub.k and C3.sub.k) resulting in homogenous gray images; selecting a standard frame rate (SFR) at which the first and the at least second sequences of image data are presented on the display; operating the display at a high display frame rate (HDFR) comprising a plurality of HDFR image slots/slices during a standard frame rate (SFR) time interval; displaying the first feed and the second feed in a time-sliced multiplexed manner in the plurality of HDFR image slots of each SFR time interval, the time-integrated luminance of the first sequence of image data presented during a standard frame rate time interval being higher than a sum of the time-integrated luminances of the second sequences of image data; wherein: the first feed and the second feed comprise gray images obtained from the combination of image data and complimentary image data (F1.sub.k and C1.sub.k; F2.sub.k and C2.sub.k; F3.sub.k and C3.sub.k) presented at equal luminance and being evenly distributed within the plurality of HDFR image slots so luminance changes of the display occur at frequencies greater than or equal to twice the SFR; the first feed of the first sequence of image data (F0.sub.k) further comprises a first complementary sequence of image data (C0.sub.k) consisting of inverse/complementary image data to the first sequence of image data such that the combination of each image (F0.sub.k and C0.sub.k) results in homogenous gray images; the gray images of the at least two feeds comprise gray images from the first feed (F0.sub.k and C0.sub.k) and gray images from the second feed (F1.sub.k and C1.sub.k), wherein at least one of the plurality of HDFR image slots shows a regular representation of the first sequence of image data at a first luminance, one of the plurality of HDFR image slots shows a representation of the second sequence of image data, one of the plurality of HDFR image slots shows a representation of the second complementary sequence of image data, one of the plurality of HDFR image slots shows a representation of the first sequence of image data at a luminance lower than the first luminance and one of the plurality of HDFR image slots shows a representation of the first complementary sequence of image data at a luminance lower than the first luminance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The present disclosure will now be described in more detail in connection with the attached drawings.

[0059] FIG. 1 is a schematic representation of a studio environment, where the method of the present disclosure can be practiced;

[0060] FIG. 2 is a schematic representation of a sports stadium, where the method of the present disclosure can be practiced;

[0061] FIG. 3 is the schematic representation of the method of the present disclosure employing two feeds;

[0062] FIG. 4 is the schematic representation of the method of the present disclosure employing three feeds;

[0063] FIG. 5 is a schematic representation of a frame sequence where individual slots have a variable length;

[0064] FIG. 6 is a frame sequence similar to the sequence of FIG. 5 with black phase insertion;

[0065] FIG. 7 is a frame sequence showing with increased proportion of a first sequence of image data; and

[0066] FIG. 8 is an alternative embodiment of the scheme of FIG. 7.

DETAILED DESCRIPTION

[0067] FIG. 1 shows a schematic representation of a digital video studio 10, which comprises an LED background wall 11, made from numerous individual LED panels 12. The LED wall 11 is an essentially seamless wall, when viewed from the front side 13, but, as can be seen from the partially visible backside 14 of wall 11, consists of individuals panels 12 fixed on suitable mounting structures 15. The studio 10 further includes an LED floor 16, also made from individual LED panels, as well as an LED ceiling 17, which is also made from individual LED panels. The studio 10 further includes conventional lighting equipment such as top lights 18 and floor lights 19, and one or more digital cameras schematically represented by a camera 20 in FIG. 1. FIG. 1 also denotes the field of view of camera 20 indicated by frustum 21. An actor 22 is shown in front of a camera 20 within the frustum of the camera's field of view. Attached to camera 22 is an auxiliary camera 23 directed in the example of FIG. 1 towards the LED sealing, where tracking patterns can be presented, which will be captured by auxiliary camera 23 attached to main camera 20, from which position and orientation of camera 20 can be derived.

[0068] FIG. 2 shows a sports stadiumin the case of FIG. 2 a soccer stadium 30having a soccer field 31 and a stand structure 32 surrounding the soccer field 31. At the circumference 33 of soccer field 31, an LED row 34 consisting of individual LED panels 35 is provided to show advertisement. In a method of the present disclosure, advertisement to be seen by the viewers present in the stadium can be presented as a first sequence of image data, while chromakey images can be presented as a second sequence of image data. In order to reduce disturbance of the live viewers present in the stadium, the present disclosure provides a third sequence of image data, which consists of image frames representing complementary/inversed images of the chromakey images of the second sequence of image data. In one embodiment, the first sequence of image data can also include tracking patterns, while the third sequence of image data can include complimentary images of said tracking patterns.

[0069] In the following, the method of the present disclosure is explained in more detail with reference to a typical sequence of HDFR image slots. In the examples presented, it is assumed that the standard frame rate corresponds to 50 Hz and consequently, the standard frame rate time interval ?T=1/SFR corresponds to 20 ms. Only one standard frame rate time interval k is shown in FIG. 3 to 8 but it is understood that corresponding time intervals k?1, k?2, . . . extend to the left of the depicted time interval and corresponding time intervals k+1, k+2, . . . extend to the right of the depicted time intervals. Moreover, in many applications, the number of HDFR image slots will be larger than the number of image slots depicted in the present examples for the sake of simplicity.

[0070] FIG. 3 shows a schematic representation of an embodiment of the method of the present disclosure where two different feeds are shown on the active display in a time-sliced multiplexed manner. In the embodiment of FIG. 3, a standard frame rate time interval of 20 ms (50 Hz) is sub-divided into 12 slots/slices, each having a duration of 1.67 ms. In the first column, e denotes the slot number, L the relative luminance at which the respective slot is presented. F0 denotes the first feed intended for direct viewers and F1 denotes the feed not intended for direct viewers. In the embodiment of FIG. 3, only two feeds are provided during each standard frame rate time interval predominantly (in slots 1, 2, 3, 6, 7, 8, 9, 10 and 12), image data content instances intended to be viewed by the direct viewer are displayed on the active display. Image data of the second feed F1 are only shown in slots 4 and 5 as a combination of image F1 and complementary/inverse image C1 so that the combined effect of slots 4 and 5 results in a (albeit not consciously) perceived gray image. To hide the insertion of image content F1 even more, the luminance of slots 4 and 5 is only 30 percent of the luminance of the slots where image data F0 are presented. According to the present disclosure, in order to ensure that in both feeds gray images are presented, slots 10 and 11 are not filled with regular representations of image data F0 of the first feed but slots 10 and 11 are used to present an image and an inverse image of the image data of the first feed. Moreover, in order to ensure that luminance changes occur at a defined frequency which is greater than the standard frame rate, the relative luminance of slots 10 and 11 has also been reduced to 30 percent of the luminance of slots 1, 2, 3, 6, 7, 8, 9 and 12. The fact to hide one slot of the image data intended to be viewed by direct viewers, namely slot 10, by presenting a corresponding complementary/inverse image in slot 11 is counter-intuitive but effectively reduces flickering resulting from the insertion of a second feed of image data.

[0071] FIG. 4 shows a similar example as FIG. 3 but in addition to the first feed intended to be viewed by direct viewers, two additional second feeds, namely a second feed F1 and a third feed F2 are presented as combinations of images F1, F2 and respective complementary/inverse images C1, C2, respectively. Similar to the embodiment of FIG. 3, the combination of images and inverse images is presented at a lower relative luminance than the images intended to be viewed by the direct viewers and the resulting gray images are again evenly distributed within the twelve HDFR image slots so that a defined frequency of luminance changes occurs which is greater than the standard frame rate 50 Hz.

[0072] The concept of having HDFR image slots of variable length will now be described in more detail. The minimum duration of an image slot equals the minimum transmission time plus Vsync signal. The GCLK Frequency should be varied to show full images within the give time.

[0073] Assuming to have a maximum of 12 image slots:

F1 is shown with gain G.sub.F1=0.5 for t.sub.F1=2 ms. C1 is then shown for the minimal time of t.sub.C1=1.67 ms and a gain of

[00004]$G_{C1}=\frac{t_{F1}}{t_{C1}}*G_{F1}=\frac{2\mathrm{ms}}{1,67\mathrm{ms}}*0.5=0.6$

[0074] FIG. 5 shows a schematic representation of a frame sequence where individual slots have a variable duration. FIG. 5a) shows an actual sequence of 9 HDFR image slots where a major proportion of the frame time interval is attributed to the first sequence of image data F0 intended to be seen by the direct viewers. Three further sequences of image data F1, F2, F3 are provided, each with its complementary/inverse sequence of image data C1, C2, C3. FIG. 5b) shows the data clock (DCLK) sequence which governs at the transmission of image data. As can be taken therefrom, during presentation of a slot, for instance F1, image data of the following slot C1 are transmitted to the active display, and so on. The image data comprise the luminance values for each LED of the active display. As an example, a LED display having a resolution of 10 bit (1024 luminance levels) comprises an LED which, according to the data clock information shall be operated at 50% of its maximum intensity. Thus, the brightness information (range 0-1023) transferred corresponds to a value of 511. FIG. 5c) shows how this value transferred into are suitable pulse width modulation PWM. A (G-clock (CLK) is generated, for instance at a normal frequency of 10 MHz. In a simple embodiment, a pulse counter counts the number of pulses until the desired value for this image slot (in this example 511) is reached. During the remainder of the pulses of the G-clock, the PWM signal is turned off. Accordingly, PWM signal is operated at a duty cycle of 50%. In a preferred embodiment, however, the active pulses are distributed evenly throughout the time interval of a slot.

[0075] FIG. 6 shows a frame sequence similar to the sequence of FIG. 5 with black phase insertion. As can be taken from FIG. 6 a) black phases having a duration of 0.1 ms are inserted in the initial portion of each of the first sequences of image data F1, F2, F3. As can be taken from FIG. 6b), the black phases are generated by switching the G-clock off during the desired black phases.

[0076] The concept of increasing the brightness of the venue feed i.e. the first sequence of image data F0 intended to be seen by the direct viewers will now be described in more detail: The inverse image is displayed at a higher current, but therefore with reduced luminance level. That way, there is headroom in the color/luminance space left and the content for the human eye of the direct viewers can be added to the image. FIG. 7 shows an example of this concept, assuming a PWM controlled brightness range of 10 bit, i.e. from 0 (black) to 1023 (maximum) intensity. The image gain factor is the proportion of the PWM controlled image brightness within that range, i.e. gain=0 corresponds to a 10-bit value of 0 and gain=1 corresponds to a 10-bit value of 1023. The actual luminance of an active light-emitting element (e.g. a LED) of the active display is given by the gain factor time the electrical current at which the element is operated times the gain factor. In a basic embodiment of the method of the present disclosure shown in FIG. 7a) F1 is displayed with gain 0.5 (i.e. at 511 bit PWM level) and current 0.2 and the complementary/inverse image C1 is displayed with the same gain and current so that the sum of F1 and C1 results in a featureless gray image. In the embodiment shown in FIG. 7b) F1 is displayed with gain 0.5 (i.e. at 511 bit PWM level) and current 0.2 and the complementary/inverse image C1 is displayed with the same gain and current so that the sum of F1 and C1 results in a featureless gray image. In the embodiment shown in FIG. 7b) F1 is also displayed with gain 0.5 and current 0.2 but C1 is displayed with gain 0.25 and current 0.4 so that the sum of F1 and C1 still results in a featureless gray image but the venue feed F0 for the direct viewers can still be added with gain 0.75 so that the overall proportion of the venue feed is increased. It has, however to be born in mind that the current-intensity relation of R, G and B LEDs varies. Thus, a color correction needs to be performed. It needs to be ensured the luminance level, at which the image content is complemented remains constant. No matter which current setting is chosen for the inverse image slot. Here it is helpful to keep in mind the amount of light (essentially the number of photons) is proportional to the luminance/brightness level B and gain G, with the current c (c ? [0.2], as the factor is given by the driver chip current setting) and the time t the image is displayed:

[00005]$n_{\mathrm{ph}}?G*B*c*t$

[0077] FIG. 8 shows an extension to the scheme of FIG. 7 where two inverse images immediately preceding and flowing a given further sequence of image data F0 (venue feed), F1 (first parallel feed), F2 (second parallel feed) plus additional image content of the venue feed are combined in one HDFR image slot to provide a frame sequence having an increased proportion of first sequence of image data F0. This allows for more flexibility and capability, especially in a low slot system like the LED floor system Black Marble commercialized by ROE Visual.

[0078] Further, this approach of HDFR image slots with variable duration can be combined with the concept of increasing the luminance of the first sequence of image data (venue feed): Accordingly, the gain of the inverse image can be calculated by:

[00006]$G_{C1}=\frac{t_{F1}*c_{F1}}{t_{C1}*c_{C1}}*G_{F1}=\frac{2\mathrm{ms}*0.2}{1,67\mathrm{ms}*0.4}*0.5=0.3$

[0079] With the currents taken from the example before. Hence, 0.7*F0 can be added to the color corrected inverse image. Under certain circumstances some driver chips can be modified by pretending to have more scanlines, but that technique has several disadvantages. However, the minimum display time would be decoupled from the transmission time.

[0080] While the present disclosure has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the disclosure lends itself to many different variations not specifically illustrated herein.

[0081] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present disclosure, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the disclosure that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, while of possible benefit in some embodiments of the disclosure, may not be desirable, and may therefore be absent, in other embodiments.