DE102016002452A1 - Technique for moving a pixel graphic - Google Patents

Abstract

A technique for moving a pixel graphic on a display unit is disclosed. A method aspect includes receiving information that assigns a first position to a pixel, receiving a value associated with the first position, representing the pixel at the first position, measuring a presentation duration of the pixel at the first position, decreasing the first one Position associated value depending on the measured display duration, representing the pixel at a second position when the reduced value reaches a predetermined threshold, and outputting the reduced value for storing.

Description

Technical area

The present disclosure generally relates to a method of displaying a pixel graphic on a display unit and to an apparatus for performing this method. Specifically, the present disclosure relates to moving a pixel graphic between multiple locations on the display unit.

background

Display units are used in a variety of everyday electrical appliances. In this case, for example, liquid crystal displays, LED displays or plasma displays are installed, for example, in televisions, in computer screens, in mobile phones or in motor vehicles.

In general, such display units are subject to aging phenomena. For example, when a consistent image is displayed at rest at the same location of a display unit for an extended period of time, a phenomenon called "burn in" may occur. This is because static images are more likely to occupy those areas of the display unit where they are displayed than other areas.

Aging phenomena are expressed after a certain period of operation, for example, in a reduced color quality of individual pixels (pixels) of the display unit. As a result, contours and transitions may emerge compared to a new display unit. Often, where the static image has been displayed for a long time, artifacts become visible as soon as the display unit displays another image. The extent of aging, for example, in OLED displays depends on the duration of operation and the displayed color with which a pixel is operated. The operating temperature of the display unit also plays a role.

The concrete physical effects that cause aging phenomena are different and depend mainly on the design of the display unit. 1 shows such aging phenomena using the example of a region to be displayed in the color white 100 an OLED-based display unit. The area to be displayed in white 100 is illuminated by a red, a green and a blue pixel (eg corresponding sub-pixels). The relative luminance, ie the relative luminance of the individual pixels, is in 1 applied over time.

At time 0, ie at the first startup of the corresponding display unit, all pixels have the same relative luminance. The area to be displayed in white 100 is thus displayed in white for a viewer accordingly. With continued operation of the display, however, the luminance of the pixels decreases and the display unit loses overall luminance, thus appearing darker for the viewer.

As in 1 However, there is a different degree of decrease in luminance over time for the differently colored pixels. Assuming a critical value that marks the end of a lifetime of a pixel at a relative luminance of 0.7, the blue pixel reaches this value in the example shown after nearly 4000 operating hours, while the red and green pixels reach this value only after more than 6000 operating hours.

This uneven decrease in luminance results in the area to be displayed white 100 Over time, it turns into a darker, yellowish-looking area 110 changed (cf. 1 ). This color change is mainly due to the fact that the blue pixel has the greatest loss of luminance. From these observations it follows that the lifetime of a pixel of an OLED display depends on the total operating time and on the color of the respective pixel. Another dependency of the lifetime of a pixel of an OLED display results from the operating temperature. If an (average) operating temperature of an OLED display increases, the in 1 shown curves of the relative luminance for the respective pixels down. The critical values of the respective luminance curves are therefore reached earlier with increasing operating temperature.

2 shows possible effects of aging on a display unit. It is in 2 an evenly aged area 200 (eg composed of several areas 110 ) and an unevenly aged area 210 (also eg composed of several areas 110 ). For comparison, the aged display areas 200 . 210 one non-aged area each 220 (eg composed of several areas 100 ) of the display unit.

In the unevenly aged area 210 Clearly horizontal gradations of brightness can be recognized, with the individual steps becoming brighter and brighter starting from the center towards the edge. That means the middle of the unevenly aged area 210 most heavily used, that is the biggest loss Having luminance, because the middle of the range 210 for example, was part of a static image over a longer period of time, while the adjacent area were not so often illuminated.

In contrast, arise for the evenly aged area 200 Although there are differences in brightness from the center to the edge, there are clearly smoother transitions between the differently stressed areas. Step-shaped transitions as in the area 210 are not recognizable here.

Should now in the unevenly aged area 210 the display unit a monochrome, for example, a solid white image are displayed against a black background, the age-related gradations are recognizable to a viewer as artifacts. On the other hand, on the evenly aged area 200 Although a solid white image is displayed against a black background, this image may vary depending on the severity of the aging compared to the non-aged area 220 look darker; however, it is for the viewer - if any - to recognize much gentler horizontal gradations.

Different techniques exist for different types of display units to prevent the above-exemplified and other signs of aging. An example of this are screen savers for computers. However, these have the disadvantage that a screen saver replaces the currently displayed image, as a result of which the image is no longer visible to a user.

The publication US 2005/0204313 A1 For preventing deterioration of a display unit, there is provided a method in which the position of an image in a certain operating mode of a display unit is shifted stepwise thereon. The displacement follows a predetermined pattern between several positions.

A pixel or an entire image is slid obliquely on the display unit until the pixel or image reaches an initial position again, ie a shift cycle has ended. The positions between which the shifts occur are stored in a memory. If the display unit is switched off and on again or is in the meantime changed to another operating mode, the shift cycle starts again.

Short outline

The object of the present disclosure is to operate a display unit such that age-related artifacts are at least reduced.

According to a first aspect, there is provided a method of moving a pixel graphic on a display unit, wherein each of a plurality of pixels of the pixel graphic is shifted between a plurality of predetermined positions, and wherein each of the positions is assigned an initial value based on a predetermined distribution. The method includes receiving information that associates a first position with a pixel, receiving a value associated with the first position that is derived from the corresponding initial value, and representing the pixel at the first position. The method further comprises measuring a display duration of the pixel at the first position and decreasing the value associated with the first position in dependence on the measured display duration of the pixel at the first position. In addition, the method includes displaying the pixel at a second position when the reduced value of the first position reaches a predetermined first threshold, and outputting the reduced value associated with the first position for storage.

The method is not limited to performing these steps in the order listed. For example, the information that associates a pixel with a first position and the value associated with the first position may be received in a common step, such as a request, or in a different order.

The display unit can be designed as an LED (Light Emitting Diode) display, for example as an OLED display. Alternatively, the display unit may be designed as LC (liquid crystal) display or as a plasma display. However, the display unit is not limited to any of these embodiments.

The plurality of predetermined positions between which the plurality of pixels are shifted may be physical pixels arranged within the display unit. Alternatively, the positions may be subpixel positions. Such sub-pixel position may include, for example, but not limited to, one-half or one-half times a physical pixel of the display unit.

In addition to the measured display duration of the pixel at the first position, reducing the value associated with the first position may depend on further factors. For example, the average operating temperature of the display unit during the measured display duration may affect the decrease in the value associated with the first position. Although the method is not so limited, an increase in the operating temperature of the display unit may result in an accelerated decrease in the value associated with the first position.

The reduction of the value associated with the first position can take place in several steps by a value which corresponds to a part of the display duration measured at the first position. Alternatively, reducing the value associated with the first position in one step may be done by a value corresponding to the display duration measured at the first position.

The pixel graphic that is moved on the display unit may include a content of a partial area of the display unit. Alternatively, the pixel graphic may include the entire area of the display unit. If the pixel graphic is smaller or larger than the total area of the display unit, it can be scaled (for example, stretched or compressed) as a whole or in its peripheral areas in order to fill in the entire area.

The method may additionally include receiving information associating the pixel with the second position and receiving a value associated with the second position derived from the corresponding initial value. Furthermore, the method may comprise measuring a display duration of the pixel at the second position and reducing the value associated with the second position as a function of the measured display duration of the pixel at the second position. The method may further comprise displaying the pixel at a third position when the reduced value of the second position reaches a predetermined second threshold and outputting the reduced value associated with the second position for storage.

Again, the method is not limited to performing the above steps in the order listed. For example, the information associating the pixel with a second position and the value associated with the second position may be received in a common step, for example, upon a request, or in reverse order. Furthermore, the same steps can be performed for other (third, fourth, fifth, etc.) positions.

In addition to the measured display duration of the pixel at the second position, reducing the value associated with the second position may depend on further factors. For example, during the measured display duration, the average operating temperature of the display unit may affect the decrease in the value associated with the second position. Although the method is not so limited, an increase in the operating temperature of the display unit may result in an accelerated decrease in the value associated with the first position.

The reduction of the value associated with the second position can take place in several steps by a respective value which corresponds to a part of the display duration measured at the second position. Alternatively, decreasing the value associated with the second position in a step may be by a value corresponding to the display duration measured at the second position. The received value associated with the first position and / or the received value associated with the second position may be the corresponding initial value. Alternatively, this value may be a stored, previously reduced value.

The plurality of positions may define a (pixel-wise, for example) contiguous area. The region may, for example, be polygonal (eg square or rectangular) or round (eg a circle).

The predetermined distribution may assign the highest initial value to a position located in a central area of the plurality of locations. In this case, the position to which the highest initial value is assigned can be in the middle of the plurality of positions. Alternatively, the predetermined distribution may also assign the highest initial value to a plurality of positions located in a central region of the plurality of positions. The predetermined distribution may be a rotationally symmetric curve, but is not limited thereto. The predetermined distribution may assign positions located in peripheral areas of the plurality of positions to the lowest initial values. The positions may be assigned the lowest initial values located in the outermost regions of the plurality of positions.

As for the predetermined distribution of the initial values, the initial values from the central area to the peripheral areas may be continuously reduced (eg, stepwise). The distribution may be based on a continuous function whose slope is zero at any point. Furthermore, the distribution can be based on a function, having different slopes. It is conceivable that the distribution is based on a function which has the lowest slope in the region of the position which assigns the highest initial value to a position of the plurality of positions. Additionally or alternatively, the distribution may be based on a function that continuously has a negative slope from the location that assigns the highest initial value to a location of the plurality of locations to the location that assigns the lowest initial value to a location of the plurality of locations , For example, the distribution may be based on a paraboloid of revolution whose peak represents the highest initial value of the distribution.

The first and / or the second threshold value can be 0. Alternatively, the first and / or second thresholds may take on any value between one and the highest initial value reduced by one. Instead of one, another predetermined decrementing increment can be selected. The pixel can be assigned as the first position the position of the plurality of positions which is assigned the highest value by the predetermined distribution and / or by the already reduced, stored values.

If, at the same time, the highest value is assigned to a plurality of positions by the predetermined distribution and / or by the already reduced, stored values, the pixel may be assigned as the first position a random position among the positions to which the highest value is assigned. Alternatively, the pixel may be assigned as a first position a certain position among the positions to which the highest value is assigned. This particular position may, for example, be the most central position among the positions to which the highest value is assigned. Alternatively, this particular position among the positions to which the highest value is assigned may be the position farthest from the center.

From the sum of all initial values of the predetermined distribution (or a period of time derived from this sum) and a (eg measured or estimated) operating time of the display unit, from which the first aging phenomena of the display unit occur, a display interval for the first pixel at the first position and for the second pixel at the second position. The specified operating time of the display unit can be at least 30 hours or at least 60 hours or at least 100 hours. The display interval can be at least one second, or at least 5 seconds, or at least 15 seconds.

According to a second aspect, there is provided a method of moving a pixel graphic on a display unit, wherein each of a plurality of pixels of the pixel graphic is shifted between a plurality of predetermined positions on the display unit and wherein each position is part of a predetermined self-intersecting trajectory. The method includes receiving information that associates the pixel with a first position, displaying the pixel at the first position, and measuring a presentation duration of the pixel at the first position. Further, the method includes receiving information that assigns the pixel a second position, displaying the pixel at the second position when the measured display duration at the first position reaches a predetermined threshold, and outputting the second position of the pixel for storage. The steps of the method are performed iteratively for the pixel according to the given trajectory.

The measured display duration of the pixel at the first position may correspond to a predetermined display interval. The given display interval can be at least one second or at least 5 seconds or at least 15 seconds.

The predefined trajectory curve can be traversed once during a predetermined (eg measured or estimated) operating time of the display unit, starting from the first aging phenomena of the display unit. The specified operating time may be at least 30 hours or at least 50 hours or at least 100 hours.

The first position may be an initial position of the trajectory. Alternatively, the first position may be an already stored position. The previously stored position may be any position on the trajectory.

The predetermined trajectory may intersect itself at different positions of the display unit at a different frequency. At this time, the predetermined trajectory at a central portion of the plurality of positions on the display unit may more frequently intersect itself than at peripheral portions of the plurality of positions on the display unit. The predetermined trajectory can be chosen so that a minimum of intersections of the trajectory results with itself.

The plurality of pixels of the pixel graphic may be shifted in parallel on the display unit. However, the method is not limited to parallel shifting of the plurality of pixels on the display unit.

The plurality of positions on the display unit for a given pixel may extend over a range of up to ± 50 pixels in the vertical direction and up to ± 50 pixels in the horizontal direction. Alternatively, the plurality of positions may be on the display unit for a particular pixel over a range of up to ± 30 pixels in the vertical direction and up to ± 30 pixels in the horizontal direction or over a range of up to 10 ± pixels in the vertical direction and extend up to ± 10 pixels in the horizontal direction.

The second position may deviate from the first position by a maximum allowable pitch of ± 5 pixels in the vertical direction or by a maximum allowable pitch of ± 5 pixels in the horizontal direction. Alternatively, the second position may be a maximum allowable increment of ± 3 pixels in the vertical direction or a maximum allowable increment of ± 3 pixels in the horizontal direction or a maximum allowable increment of ± 1 pixel in the vertical direction or by a maximum allowable increment deviate from the first position by ± 1 pixel in the horizontal direction. Within this maximum permissible step size, the second position assigned to the pixel is the position which, due to the predetermined distribution and / or the already reduced stored values, is assigned the highest value within the maximum permissible step size.

Another aspect of the disclosure relates to a computer program product. The computer program product includes program code parts that, when executed by a processor, are configured to perform the method of the first aspect of the disclosure and to perform the method of the second aspect of the disclosure.

Another aspect of the disclosure relates to a control device for a display unit. The control device includes a memory and a processor configured to perform the method according to the first aspect of the disclosure or the method according to the second aspect of the disclosure. The memory may at least partially comprise a nonvolatile memory, for example a flash memory or a ROM memory.

The control device may be included in a system which additionally includes a display unit. The display unit may include, but is not limited to, an OLED display. Alternatively, the display unit may comprise an IC display or any other display suitable for displaying content.

The system may be included in a motor vehicle. In this case, the system can be permanently installed in the motor vehicle, for example on the dashboard of the motor vehicle or at any other suitable location. Alternatively, the system may be adapted to be removably mounted in a motor vehicle. For example, the system may be provided as a portable system to be removably attached to the windshield of the motor vehicle.

Brief description of the drawings

Further aspects, advantages and details of the present disclosure will become apparent from the following description of the embodiments in conjunction with the figures, wherein:

1 shows by way of example the change in the relative luminance of individual pixels of an OLED display as a function of the operating time;

2 exemplifies the effects of such luminance changes on the display unit;

3 schematically shows a motor vehicle and a system contained therein according to an embodiment;

4 a flow chart according to an embodiment of a method for moving a pixel graphic on a display unit shows;

5A shows a predetermined distribution for different positions on a display unit;

5B shows exemplary functions on which a given distribution can be based;

6 a predetermined distribution according to the method according to 4 and shows an example assignment of a pixel to certain positions;

7 shows a distribution in which the values are compared with the predetermined distribution according to the method 4 were reduced after a pixel has been assigned to certain positions;

8th a flowchart according to another embodiment of a method for moving a pixel graphic on a display unit shows; and

9 a part of a predetermined trajectory according to the embodiment according to 9 shows.

Detailed description

The present disclosure is explained, inter alia, with reference to schematic flow charts. The technical teaching underlying these diagrams can be implemented in hardware as well as software or a combination of hardware and software. These include digital signal processors, application-specific integrated circuits, field programmable gate arrays and other suitable switching and computational components. The disclosure in some implementations is intended to be based on the 1 and 2 counteract the aging phenomena described.

The present disclosure relates, according to an embodiment, schematically in 3 is shown, a in a motor vehicle 300 arranged system 310 that is both a control device 320 as well as a display unit 330 includes. The control device 320 itself includes a memory 340 and a processor 350 , The processor 350 is adapted to the methods presented here for moving a pixel graphic on the display unit 330 or certain steps of these methods under control of one in memory 340 stored program. By a certain distribution of the displacement positions or by a certain predetermined displacement curve, thereby a uniform aging of the display unit 330 similar to the one in 2 illustrated evenly aged area 200 be achieved.

The system 310 can be in any motor vehicle 300 be arranged for example in a car or in a truck. This can be done by the system 310 be firmly installed in the vehicle and connected to the electrical system. The system 310 can be powered by the electrical system. The system 310 However, it may also be embodied as a portable system that is operated by a user at a suitable location in the motor vehicle 300 or outside of it. A suitable place to attach the system 310 For example, would be a bracket on the back of a seat (eg, a driver or passenger seat). Alternatively, an attachment in a bracket in the area of the dashboard on the driver or passenger side or in between conceivable. Suitable portable systems are, for example, tablet computers or mobile navigation systems. If the system 310 is designed as a portable system, it may additionally comprise an accumulator (not shown in the picture), which may be rechargeable via the electrical system.

The memory 340 may include nonvolatile and volatile memory. The memory 340 or portions thereof may be implemented as flash memory, ROM, (E) EPROM, RAM, or any other digital memory. The processor 350 can be implemented as a digital signal processor or as a microcontroller. Alternatively, the processor may be implemented as any other suitable computing unit.

The present disclosure, in one embodiment, provides a method for moving a pixel graphic on a display unit 330 to a uniform load and thus a uniform aging of the display unit 330 to reach. A corresponding method is shown schematically in the flowchart in FIG 4 shown. This method can be achieved, for example, by the control device 320 ( 3 ) are performed programmatically to the pixel graphic on the display unit 330 to move.

According to the method according to 4 For example, each of a plurality of pixels of the pixel graphic is interposed between a plurality of predetermined positions on the display unit 330 shifted, wherein each of the positions is assigned an initial value based on a predetermined distribution. The plurality of pixels refers in particular to adjacent pixels in a contiguous area, which together on the display unit 330 be moved.

Both according to the method 4 , as well as according to the method 8th (will be described later), the plurality of predetermined positions between which the plurality of pixels are shifted may be physical pixels arranged within the display unit on a certain area. Alternatively, the positions may be sub-pixel positions that comprise a multiple or even a portion of a physical pixel of the display unit.

Such sub-pixel positions may be determined by means of suitable interpolation methods and subsequently used as the plurality of predetermined positions between which the plurality of pixels are shifted. An example of a suitable interpolation method using a fractional delay filter is disclosed in the document Deng, Tian-Bo, "High-Resolution Image Interpolation Using Two-Dimensional Lagrange-Type Variable Fractional-Delay Filter," International Symposium on Nonlinear Theory and Applications (NOLTA2005), Bruges, Belgium, October 2005 ,

For each of the adjacent pixels being moved, the same steps are performed. The majority of the pixels of the Pixel graphics can be parallel to each other on the display unit 330 be moved. The following description therefore only refers to one of these pixels in each case.

The method according to 4 starts with one step 410 receiving information that assigns a first position to a pixel. This position can be any position within the given distribution. In this case, the pixel can be assigned as the first position the position, which in turn is assigned the highest initial value. In the context of the method, it is possible that the positions are no longer assigned the initial values of the distribution, but already reduced values compared to the initial values. Then, for example, the pixel may be assigned to the pixel as the first position the position of the distribution to which the highest value among the already reduced values is assigned.

In a further step 420 a value assigned to the first position is received. This value is derived from the corresponding initial value of the given distribution. The value can therefore be the exact initial value of the predefined distribution or else a value that has already been reduced compared with this initial value, for example because the pixel was already displayed at the first position in the course of an earlier execution of the method.

The initial values of the positions where the pixel can be displayed depend on the given distribution. The predefined distribution is chosen such that as smooth as possible transitions between adjacent initial values result. In concrete terms, this may mean that the differences between adjacent initial values, for example, do not differ by more than 25%. However, the method is not limited to this; In particular, larger deviations between adjacent initial values may result in the marginal areas of the given distribution.

The predetermined distribution may assign the highest initial value of the distribution to a central position, in particular the position which is in the middle of the positions between which the pixel is moved. The initial values may decrease continuously towards the outer positions, so that positions located in the peripheral areas of the positions between which the pixel is shifted are assigned the lowest initial values. The highest initial value of the distribution can occur exactly once or several times. In addition, the lowest initial value may occur exactly once or alternatively several times in the distribution.

An example of a given distribution, the different positions on the display unit 330 assigning certain initial values is in 5A shown. The default distribution 510 can except as an initial value distribution for the embodiment according to 4 also serve as a frequency distribution that a predetermined trajectory according to the embodiment according to 8th underlying (see the description of the 8th and 9 ).

The area of the display unit 330 in which the given distribution 510 Assigning certain initial values to the various positions is here limited in each case from position 0 to ± 10 pixels in the horizontal direction and ± 10 pixels in the vertical direction. Overall, the area includes 441 positions. In this example, the positions correspond to physical pixels on the display unit. As already indicated, the positions according to the methods according to the 4 and 8th however, also refer to sub-pixel position which deviate from the physical pixels. For example, if the positions were related to sub-pixel locations, each representing one-half of a physical pixel, 882 locations would appear within the area, instead of the 441 locations, between which the plurality of pixels could be moved. Alternatively, the sub-pixel positions may also be more than one physical pixel. For example, if the positions were related to sub-pixel locations, each representing twice the physical pixel, would be within the area rather than the 441 locations 220 Give positions between which the plurality of pixels can be shifted.

The distribution assigns to each of these 441 positions an initial value which, as mentioned, according to the embodiment in FIG 8th can also mark a certain frequency. The initial values vary in the illustrated example from 0 in the outermost edge regions to a value of 64 in the center of the distribution. The distribution 510 , which is based here for example on a paraboloid of revolution, has a small pitch in the region of the center. In comparison, the slope becomes larger towards the edge areas. The parabola, which underlies the distribution, results in a radial symmetry of the distribution.

5B shows next to a parabola 520 (middle illustration), on which the in 5A shown distribution, two more exemplary functions for given distributions. Around the axis, on which the frequency (according to the initial values) is plotted, is in 5B each indicated a rotation of the functions by 90 °. A rotation of 360 ° results in a distribution, which is the given distribution for the Move the pixels on the display unit 330 can serve. This distribution can be a predetermined trajectory according to the embodiment in 8th underlie.

On the left side shows 5B a function 530 that between two short, each near the axis sections that have a low slope, a longer, almost linear sloping section with compared to the two short sections have much greater slope. For the distribution that is based on this function, as for the distribution that results on the parabola 520 based, a radial symmetry about the frequency axis. The different effect of the distributions based on the functions 520 . 530 when moving the pixels on the display unit 330 is created from the views 550 and 560 clearly, each showing a top view of distributions based on the functions 520 . 530 demonstrate. Darker areas indicate a higher frequency, ie a correspondingly higher initial value. This results, for example, in the function 530 a smooth transition between the initial values of adjacent pixels both in the center of the distribution and in their peripheral areas, while smooth transitions between adjacent initial values for the function 520 rather confined to the center.

A third variant for a function based on the given distribution 540 shows the right side of 5B , Here the initial values from the center decrease only very slowly. In contrast to the edge regions, the result is a comparably large slope of the function 540 , This is also in the view 570 to recognize, based on a quadrant-related symmetry of distribution, on the function 540 based, points out. This results in smooth transitions between the initial values of the adjacent pixels from the center over long distances of the distribution. Only in the peripheral areas, similar to the view 560 , a coarser transition recognizable.

If the default distribution, as on the right side of 5B quadrant symmetric, this offers the advantage over rotationally symmetric distributions that none of the positions which assign the initial distribution to the given distribution is assigned the value 0. In the above example, a quadrant symmetric distribution would assign each of the 441 positions a value greater than zero. The result is that the positions within which the pixel can be moved on the display unit extend over a larger area. A maximum shift range would therefore be even better exploitable.

In a further step 430 the pixel is displayed at the first position. The representation can take place temporally according to a predetermined display interval. This display interval can be in the range of several seconds. The reason for this is that too fast a shift of the pixel graphics would become perceptible to the observer of the display unit. The display interval may be dependent on an operating time of the display unit, from the first signs of aging of the display unit occur. Furthermore, the display interval may depend on the sum of all initial values.

6 shows a plan view of the predetermined distribution 510 according to 5A , The initial values are represented in the form of numerical values in a matrix whose columns are a horizontal displacement position in pixels and their rows a vertical displacement position in pixels on the display unit 330 mark. The rotational symmetry of the distribution is indicated by a dashed circle. In the in 6 As shown, the area in which the pixel is shifted extends over ± 10 pixels in both the vertical and horizontal directions. A smaller or a larger displacement range are also conceivable, as are displacement ranges that extend in the vertical or in the horizontal direction over a different number of pixels. The initial values define a possible display duration of a pixel at a specific position. So the pixel can according to the in 6 shown distribution at the position 0/0 having an initial value of 64, twice as long as, for example, at the position 7/1 having an initial value of 32, are shown.

In a further step 440 an actual display duration of the pixel at the first position is measured. This can be done, for example, by a timer which measures the time while the pixel is being displayed at the first position. Such a presentation duration may correspond to a single presentation interval or a multiple of the presentation interval. A maximum display duration for the pixel at the first position results from the value associated with the first position and the display interval. In principle, since the first pixel can be assigned any position where the value is not 0, the first pixel in the distribution can be in 6 For example, be assigned to the position 5 / -6. The value at this position is 24. If the display interval is set to 5 seconds, the maximum display time of the pixel at the first position is thus 24 × 5 sec. = 120 seconds. In the border areas, for example at position 4/9, the presentation time would therefore be limited to 5 seconds.

In a further step 450 For example, the value associated with the first position is reduced depending on the measured display duration of the pixel at the first position. The value can be continuously reduced while measuring the actual display duration. In the above example, this would mean that the value at position 5 / -6, starting from 24, is decreased by one every 5 seconds. On the other hand, the value can also be reduced by the value corresponding to the entire display duration after the actual display duration has expired. Again, referring to the above example, this would mean that the value at position 5 / -6, starting from 24, is reduced by 24 after 120 seconds have elapsed. Will the display unit 330 off, the measured display time can be stored in memory 340 get saved. Thereby, measuring the display duration of the pixel at the first position after turning on the display unit again 330 to be continued. If in the above example the display unit 330 For example, after a display duration of 100 seconds is turned off, after re-switching the display unit 330 another 20 seconds during which the pixel is displayed at the first position. Then the value is reduced by 24.

In a further step 460 For example, the pixel is displayed at a second position when the reduced value of the first position reaches a predetermined first threshold. The default threshold can be 0. This would be the case for example in the above example. Alternatively, the threshold could also have any other value between one and the initial value reduced by one. If the threshold value selected in the above example was 10, the pixel would be displayed at the first position 14 × 5 sec = 70 seconds. After this time, the pixel is displayed at the second position.

The fact that the pixel is displayed at the second position after the expiration of the display duration, the pixel is moved from the first to the second position. As already mentioned, several pixels arranged next to each other can be displayed in parallel on the display unit 330 be moved. Alternatively, also the entire content of the display unit 330 be moved.

For example, a single shift step may occur within a maximum increment in either the horizontal or vertical direction. This maximum step size can be the same in the horizontal and in the vertical direction. Alternatively, the maximum step size in vertical and horizontal directions may take different values. For the in 6 As shown, the maximum step size is limited to ± 1 pixel in horizontal or vertical direction. Thus, starting from the first position 5 / -6, only one of the positions 5 / -7, 6 / -6, 5 / -5 and 4 / -6 comes into question as the second position for the pixel. However, shifting steps within which a pixel is shifted in both the horizontal and vertical directions are also possible. In this case, the pixel could also be skewed on the display unit 330 be moved. For the example in 6 Thus, positions 4 / -7, 6 / -7, 4 / -5 and 6 / -5 would also be the second position for the pixel.

7 shows another example of a distribution according to the method according to 4 , Here, various shift operations take place between time T ₀ and time T ₁₀ . The display interval is in 7 15 seconds shown. The threshold, which marks the time of the pixel shift, should be 0 here. When starting the procedure, the pixel is assigned the position 0/0. The initial value at this position is 20. As a result, the pixel is displayed at this position for 20 × 15 sec., Ie for a total of 5 min.

Within a maximum allowable increment of ± 1 pixel, moving to position 0 / -2 would not be possible immediately after reaching the threshold at the first position. Will the display unit 330 however, intermittently turned off or a fast-moving image on the display unit due, for example, to a scrolling operation performed by the user 330 can be displayed after switching the display unit back on 330 or to jump to the position 0 / -2 after the completion of the scrolling operation at time T ₁ . This jump or shift can alternatively also take place at the beginning or during a scrolling operation performed by the user.

Also conceivable are several shift steps during a scrolling operation. In this case, it can have the advantageous effect that, in general, during the representation of a rapidly moving image, even a shift that exceeds the maximum permissible step size is not visible to the user. The maximum permissible step size must therefore not be taken into account in such a case.

In a further step 470 the reduced value assigned to the first position is output for storage. For the in 7 The example shown for position 0/0 is the value 0 for storing in memory 340 output. The stored value may then, when the process is executed again, be an already reduced value of Initial value assigned to a particular position. For example, in step 420 such a stored value will be received. This can be particularly useful if the value for a specific position has not been reduced to 0. Otherwise, the pixel at this position can not be displayed at first.

The method according to 4 Optionally, additional steps (in 4 not shown). An optional step may be, for example, receiving information that associates the pixel with the second position. For the in 7 In the example shown, the pixel is assigned the position 0 / -2 as the second position. In this case, the second position can in particular depend on the step size to be observed, but also on the position which can be assigned within this step distance with the highest (initial) value (in this case not the case). Another optional step may include receiving a value associated with the second position. Here the position 0 / -2 is assigned the value 6, thus the pixel is displayed at the second position for 6 × 15 sec., Ie for 90 seconds.

Other optional steps may include measuring a display duration of the pixel at the second position and decreasing the value associated with the second position in dependence on the measured display duration of the pixel at the second position. The steps may be similar or equal to the steps 440 respectively. 450 be performed. For the example in 7 this means that the value at position 0 / -2 is reduced to 0 after a measured display duration of 90 seconds.

A further optional step may be displaying the pixel at a third position when the reduced value of the second position reaches a predetermined second threshold. The second threshold may be similar to the first threshold, but may alternatively assume an arbitrary value between one and the reduced by one initial value of the second position. After the value at the position 0 / -2 the threshold, in the example in 7 If 0 is reached, the pixel is moved to the third position 0 / -1, taking into account the maximum permissible step size.

Another optional step may be to output the reduced value associated with the second position for storage. The stored value can then be similar to step 470 , as an already reduced value associated with a particular position. For the example in 7 So the value 0 will be stored in memory 340 output.

The steps described by way of example can be carried out according to the method until all the values of the distribution have been reduced to the respective predefined threshold values. If all thresholds are 0, a maximum possible presentation time results at each position, which in turn results in a minimization of shift steps since the pixel at each of the positions is displayed exactly once.

If for all positions of distribution in memory 340 the predetermined threshold is reached and this threshold is not 0, by the control device 320 new thresholds are set for the respective positions and the steps described by way of example according to the method according to 4 can be performed again until all values of the distribution have been reduced to the new predetermined thresholds.

If for all positions of distribution in memory 340 If the value 0 is stored, no further steps are possible. Accordingly, then an entire shift cycle is completed and the control device 320 can restore all initial values of the given distribution. Alternatively, the control device 320 the predetermined distribution by another suitable, predetermined distribution in the memory 340 can be deposited, replace.

For the example in 7 In accordance with the method, the pixel is displayed on the display unit between times T ₁ and T ₈ 330 moved along the positions 0 / -2, 0 / -1, 1 / -1, 1/0, 1/1, 0/1, -1/1 and finally -1/0. The presentation duration at the respective positions always follows the value assigned to the positions. Thereafter, the process is interrupted, for example by switching off the display unit. After powering up, the pixel is displayed at position -1/2 for 45 seconds and after a shift step for 75 seconds at position 0/2. Since the value for all positions at which the pixel was displayed has been reduced to the threshold value 0, the value 0 is output for the respective positions for saving. At these positions, the pixel can then no longer be displayed in the context of the current shift cycle.

The present disclosure, according to another embodiment, provides a method for moving a pixel graphic on a display unit 330 to a uniform load and thus a uniform aging of the display unit 330 to reach. A corresponding method is shown schematically in the flowchart in FIG 8th shown. This procedure can for example by the control device 320 ( 3 ) are performed programmatically to the pixel graphic on the display unit 330 to move.

According to the method according to 8th For example, each of a plurality of pixels of the pixel graphic is interposed between a plurality of predetermined positions on the display unit 330 shifted, each position is part of a predetermined, self-intersecting trajectory.

Similar to the method according to 4 In this case, the plurality of pixels refers in particular to adjacent pixels, which together on the display unit 330 be moved.

The same steps are performed for each of the adjacent pixels that are being moved. The plurality of pixels of the pixel graphics can be parallel to each other on the display unit 330 be moved. The following description therefore only refers to one of these pixels in each case.

The method according to 8th starts with one step 810 receiving information that assigns a first position to a pixel. This position may be, for example, an initial position of the predetermined trajectory. Alternatively, the first position may be an already stored position. For example, this position in the course of a previous execution of the method in memory 340 deposited.

In a further step 820 the pixel is displayed at the first position. The representation can take place temporally according to a predetermined presentation interval. This display interval can be in the range of several seconds. The reason for this is that too fast a shift of the pixel graphics for the viewer of the display unit 330 would become noticeable.

The given trajectory can in turn be based on a frequency distribution. 9 shows by way of example a part of a predetermined trajectory, the frequency distribution after 5A underlying. Alternatively, the predetermined trajectory can also be one of the functions rotated by 360 ° around the frequency axis 530 . 540 or any other function that gives rise to a smooth transition of frequencies (see also 5A and 5B ).

In 9 In a matrix, frequency values of the distribution underlying the trajectory are shown. The rows and columns of the matrix indicate horizontal and vertical positions on the display unit 330 in pixels. The rotational symmetry of the distribution is indicated by a dashed circle. In the in 9 As shown, the area in which the pixel is shifted extends over ± 10 pixels in both the vertical and horizontal directions. Alternatively, the range may be limited to a maximum of ± 5 pixels or a maximum of ± 20 pixels in each direction. In addition, a shift range is conceivable, which extends in the vertical or in the horizontal direction over a different number of pixels.

The predetermined trajectory is during a predetermined period of operation of the display unit 330 , from which the first signs of aging occur, within the shift range as part of the steps 810 to 870 once complete. The numerical values in 9 are the number of times a given position appears along a given trajectory. The numbers thus say how often the pixel is displayed at the respective position during a complete traversal of the trajectory.

In 9 For example, position -4 / -7, which marks the start of the part of a given trajectory, is divided by the distribution 510 the frequency value 22 assigned. This means that the pixel is at position -4 / -7 according to the distribution 510 can be displayed exactly 22 times for the given display interval. In the given trajectory the position -4 / -7 is therefore contained 22 times. From the sum of all frequency values, there is accordingly a total number of display intervals along the given trajectory, which for the example in FIG 9 is about 10,000. In each case there is a shift step between the display intervals.

Alternatively, it is possible for the pixel to be displayed at a position along the given trajectory for a longer time than the predetermined display interval. Im in 9 For example, the pixel could be displayed at position -4 / -7 for a period of 20 display intervals, for example. It should be noted, however, that not all available display intervals can be used up at one position if the position is still needed at a later point in time as the intersection of the trajectory with itself. In general, however, it is possible to minimize shift steps when the pixel is displayed at a position for a longer period of time than just the predetermined display interval.

All positions of the given trajectory are in the memory 340 saved. In addition, one of the trajectory underlying distribution in the memory 340 saved. Alternatively, several of the trajectory may be used lying distributions in the memory 340 be saved. If the method according to 8th is performed for the first time, creates the control device 320 from a stored distribution the predetermined trajectory, which then during the predetermined operating time of the display unit 330 , from the first signs of aging occur, is once completed completely. Alternatively, it is possible that the complete trajectory before the first implementation of the method according to 8th is calculated. Then only the calculated trajectory can be stored 340 be deposited.

The predetermined display interval may depend on the operating time of the display unit 330 be dependent on the first signs of aging occur. Furthermore, the predetermined display interval may be dependent on the sum of all display intervals along the trajectory. If, for example, a duration of 30 hours for the operating time from which the first signs of aging occur is assumed, and the sum of all display intervals along the trajectory is as for the example in FIG 9 about 10,000, so there is between the shift steps in each case a predetermined display interval of about 11 seconds.

In a further step 830 a display duration of the pixel at the first position is measured. This can be done, for example, by a timer which measures the time while the pixel is being displayed at the first position. The measured presentation time is correct, except when the display unit 330 is turned off during the predetermined display interval, with the predetermined display interval match. The measurement of the presentation duration thus serves, for example, for information about the time at which a shift step is to be carried out.

In a further step 840 receive information that assigns the pixel a second position. This second position may be within a maximum increment in either horizontal or vertical direction. The maximum step size can be the same in horizontal and vertical direction. Alternatively, the maximum step size in vertical and horizontal directions may take different values. For the in 9 As shown, the maximum step size is limited to ± 1 pixel in horizontal or vertical direction. Thus, starting from the first position -4 / -7, only one of the positions -3 / -7, -4 / -6, -5 / -7 and -4 / -8 comes into question as the second position for the pixel.

Alternatively, shift steps are also possible within which a pixel is shifted in both the horizontal and vertical directions. In this case, the pixel could also be skewed on the display unit 330 be moved. For the example in 9 Thus, the positions -3 / -8, -3 / -6, -5 / -6 and -5 / -8 would also be considered as the second position for the pixel.

In a further step 850 the pixel is displayed at the second position when the measured display duration at the first position reaches a predetermined threshold. The predetermined threshold value may correspond, for example, to the predetermined display interval. For the example in 9 this means that the pixel is displayed at the first position -4 / -7 at the second position -3 / -7 after measuring a display duration of 11 seconds.

The fact that the pixel is displayed at the second position after reaching the threshold, the pixel is moved from the first to the second position. As already mentioned, several pixels arranged next to each other can be displayed in parallel on the display unit 330 be moved. Alternatively, also the entire content of the display unit 330 be moved.

In a further step 860 the second position associated with the pixel is output for storage. For the in 9 As shown in the example, the position -3 / -7 is output for saving. This position can then be made available as an already stored position of the trajectory when the method is executed again. For example, in step 810 such stored position will be received.

Another Step 870 includes iterative steps in several steps 810 to 860 , For the in 9 As shown, this means that information that associates the pixel with the position -3 / -7 will be received and that the pixel will be displayed at that position. The presentation time at this position is measured. As soon as the display duration reaches the specified display interval, ie the predefined threshold value, the pixel is displayed at position -2 / -7. This position was previously received as information. The position -2 / -7 will then be saved in memory 340 output.

As part of the iterative implementation of the steps 810 to 860 the pixel will go along in 9 shown in succession at the positions -1 / -7, 0 / -7, 1 / -7, 2 / -7, 3 / -7, 4 / -7, 4 / -6, 4 / -5, 3 / -5, 2 / -5, 2 / -6, 2 / -7, 2 / -8 and 2 / -9. The specified display interval is 11 seconds in each case. At the point 2 / -7 the given trajectory intersects itself.

If the given trajectory is completely traversed once, several such intersections of the trajectory arise with itself. The control device 320 can create the trajectory from the given distribution so that there is a minimum of intersections of the trajectory with itself.

The frequency with which the given trajectory cuts itself at a particular position varies between positions. Thus, the given trajectory intersects in 9 Example shown in the central area of the positions more often even than in peripheral areas of the positions. At the positions where the pixel is displayed only once during the complete trajectory of the trajectory (for example at the position -4 / -9), there are no intersections of the trajectory with itself. Most intersections of the trajectory with itself arise at position 0/0.

If the process is interrupted, for example because the display unit 330 is turned off or because a fast moving picture on the display unit 330 is shown in one step 860 the position of the pixel on which it is being displayed is output for storage. When the display unit is switched on again 330 can then in one step 810 receive this stored position and assigned to the pixel as the first position. This way is in memory 340 In addition to the given trajectory always an entry point deposited, which marks the position within the predetermined trajectory on which the pixel was last displayed.

Once the trajectory has been completely traversed, so in the example in 9 Once each of the approximately 10,000 required displacement steps has been performed and the pixel has been represented at the same position at the appropriate frequency, the entry point can be reset to the initial position of the trajectory. Alternatively, the trajectory may be replaced by another suitable trajectory, and the entry point may be set to the initial position of that trajectory.

The present disclosure provides several aspects of a method of operating a display unit to avoid artifacts as it ages. In carrying out the method, certain areas on the display unit or the entire content of the display unit are shifted so that the displacements are imperceptible to a viewer.

In one aspect, the displacements are based on a predetermined trajectory that is completed once in the course of a shift cycle. The trajectory is chosen so that over a period of operation, occur from the first signs of aging of the display unit, as uniform as possible exposure of individual areas of the display unit.

In another aspect, the shifts are based on a predetermined distribution that assigns certain initial values to different shifts. These initial values each determine a maximum display duration at the respective shift positions. By optimally utilizing these maximum display durations between individual shift steps, the number of shift steps can be minimized.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2005/0204313 A1 [0014]

Cited non-patent literature

• Deng, Tian-Bo, "High-Resolution Image Interpolation Using Two-Dimensional Lagrange-Type Variable Fractional-Delay Filter," International Symposium on Nonlinear Theory and Applications (NOLTA2005), Bruges, Belgium, October 2005 [0064]

Claims (24)

A method for moving a pixel graphic on a display unit, wherein each of a plurality of pixels of the pixel graphic is shifted between a plurality of predetermined positions on the display unit, wherein each of the positions is assigned an initial value based on a predetermined distribution, and wherein the method comprises: Receiving information that assigns a first position to a pixel; Receiving a value associated with the first position derived from the corresponding initial value; Representing the pixel at the first position; Measuring a display duration of the pixel at the first position; Reducing the value associated with the first position as a function of the measured display duration of the pixel at the first position; Representing the pixel at a second position when the reduced value of the first position reaches a predetermined first threshold; and Outputting the reduced value associated with the first position for storage. The method of claim 1, wherein the method additionally comprises: Receiving information that associates the second position with the pixel; Receiving a value associated with the second position derived from the corresponding initial value; Measuring a display duration of the pixel at the second position; Reducing the value associated with the second position in dependence on the measured display duration of the pixel at the second position; Representing the pixel at a third position when the reduced value of the second position reaches a predetermined second threshold value; and Outputting the reduced value associated with the second position for storage. The method of claim 1 or 2, wherein the received, the first position associated value and / or the received, the second position associated value is the corresponding initial value or a stored, already previously reduced value. Method according to one of the preceding claims, wherein the predetermined distribution of a position which is located in a central region of the plurality of positions, the highest initial value assigns. A method according to any one of the preceding claims, wherein the predetermined distribution assigns positions located in peripheral areas of the plurality of locations to the lowest initial values. A method according to claims 4 and 5, wherein the initial values continuously decrease from the central area to the peripheral areas. Method according to one of the preceding claims, wherein the first and / or the second threshold value are 0. Method according to one of the preceding claims, wherein the pixel is assigned as the first position that position of the plurality of positions, which is assigned by the predetermined distribution and / or by the already reduced stored values of the highest value. Method according to one of claims 3 to 8, wherein from the sum of all initial values of the predetermined distribution and an operating time of the display unit, from the first aging phenomena of the display unit occur, a display interval for the first pixel at the first position and for the second pixel at the second position. A method for moving a pixel graphic on a display unit, wherein each of a plurality of pixels of the pixel graphic is translated between a plurality of predetermined positions on the display unit, each position being part of a predetermined self-intersecting trajectory, and wherein the method comprises: Receiving information that associates the pixel with a first position; Representing the pixel at the first position; Measuring a display duration of the pixel at the first position; Receiving information that assigns the pixel a second position; Representing the pixel at the second position when the measured display duration at the first position reaches a predetermined threshold; Outputting the second position of the pixel for storage; and iteratively performing the steps described above for the pixel according to the given trajectory. The method of claim 10, wherein the predetermined trajectory during a predetermined period of operation of the display unit, occur from the first aging phenomena of the display unit, once passed completely. The method of claim 10 or 11, wherein the first position is an initial position of the trajectory. The method of claim 10 or 11, wherein the first position is an already stored previously position. Method according to one of claims 10 to 13, wherein the predetermined trajectory intersects at different positions of the display unit with a different frequency itself. The method of claim 14, wherein the predetermined trajectory intersects more frequently in a central region of the plurality of positions on the display unit than in peripheral regions of the plurality of positions on the display unit. Method according to one of the preceding claims, wherein the plurality of pixels of the pixel graphics are shifted in parallel on the display unit. A method according to any one of the preceding claims, wherein the plurality of positions on the display unit for a given pixel extend over a range of up to ± 50 pixels in the vertical direction and up to ± 50 pixels in the horizontal direction. Method according to one of the preceding claims, wherein the second position deviates from the first position by a maximum permissible pitch of ± 5 pixels in the vertical direction or by a maximum permissible pitch of ± 5 pixels in the horizontal direction. The method of claim 18 in combination with one of claims 1 to 9, wherein the pixel is assigned as the second position, the position, which is assigned by the predetermined distribution and / or by the already reduced, stored values, the highest value within the maximum allowable increment , A computer program product comprising program code portions which, when executed by a processor, are adapted to perform the method of any one of claims 1 to 9 and 16 to 19 and to perform the method of any of claims 10 to 118. Control device for a display unit, comprising: a memory; and a processor adapted to perform the method of any one of claims 1 to 9 and 16 to 19 or the method of any one of claims 10 to 18. System comprising: the control device for a display unit according to claim 21; and a display unit. The system of claim 22, wherein the display unit comprises an OLED display. Motor vehicle comprising the system according to claim 22 or 23.

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