DE20321035U1 - Operating display affected by wear involves integrating each image point wear value over image point operating time, computing correction values taking into account wear values, driving display using corrected values - Google Patents

Abstract

The method involves integrating over the operating time and intensity to determine separate image point wear values for the different primary colors and evaluating these with a logic element (2) to produce image point correction values to make the image point wear comparable. It involves integrating each image point wear over the image point operating time, computing correction values taking into account the wear values and driving the display (1) using the corrected values. The stages of the process are decoupled in time. An independent claim is also included for a display affected by wear.

Description

The The invention relates to a weary display and a Method for operating a wear-prone display, in particular a plasma display panel or an organic display, with defined pixels, each pixel a memory address in a memory element for recording the operating time of a assigned to each pixel and also over the operating time and intensity of operation to determine a Pixel wear value is integrated and for each pixel a pixel wear value, respectively and / or a parameter proportional to the respective pixel wear values is stored and subsequently due to the evaluation of the respective pixel wear values by means of of a logic element, a correction signal for equalizing the Pixel wear is produced.

Such a method for protecting against the burning of pixels in the plasma display is the abstract of the Japanese patent application JP 2002091373 A previously known.

at the prior art method is the display time of each pixel a display detected and in response to predetermined difference values or thresholds is then generated a video signal and on the Display to display the display time of each phosphor element of the display approximately uniform.

The aforementioned plasma display panels, called PDPs for short essentially made of two panes of glass that fit together perfectly are. Between the two glass substrates cells are arranged, which are filled with inert gas, preferably neon or xenon. In the lower substrate, these cells are phosphorus in the primary colors red, Green and Blue coated. thin Electrodes are on the bottom and top, transparent glass substrates applied. A voltage is generated with a plasma pulse generator, the at the mentioned Electrodes used to control a discharge process, the ultraviolet Radiation generated, applied. This ultraviolet radiation brings the phosphor coating of the display lights up. Any color can then by a combination of the primary colors red, green and blue be generated. Depending on the image content, each individual separate color cell will be used addressed.

The particular advantages of plasma technology are in the high achievable Image brightness, the only is limited by the consumption of phosphorus and a viewing angle of at least 160 degrees. About that In addition, any plasma displays have excellent contrast values, whereby by appropriate tint the front glass substrate or by using a suitable upstream filter element a good black level of the image representation and / or a desired color correction can be achieved for example to avoid an orange sting.

Indeed Such plasma displays have system-inherent disadvantages. Analogous to the tube monitor Phosphorus limits the life expectancy of the display Consumables are. Steady images over a longer period on the display shown, the phosphor consumes and the displayed image burns thus enter the picture.

The Luminosity of phosphorus inevitably fades with each hour of operation and thus the brightness and contrast of the plasma display.

to Time recommend the manufacturers of plasma display panels the use screensavers to mitigate the described burn-in effect or to avoid. However, it should be remembered that the effect even with running and moving pictures, such as feature films, occur can be in which about the logo of a television station or the known Black bars are permanently displayed at the edge of the picture and thus in this display section the problem of a partially elevated or reduced wear consists.

Furthermore must with regard to the wear characteristics Of the phosphorus, be aware that the wear characteristics the basic colors red, green and blue of the phosphor individually, so that the Color temperature range of a display during its lifetime quite change can. With regard to this problem brings the use of screensavers no benefit.

alternative are other methods, such as image shifting a method of conscious image shifting to equalize the wear or an automatic brightness reduction in still images known.

From the JP 2002006796 A Another method is known to improve the long-term performance of plasma displays. In accordance with this method, the individual operating time of the red, green and blue phosphor elements for the display as a whole is analyzed by means of the detection of a time integral for each pixel and correction signals for each of the three primary colors red, green and blue are generated on the basis of this determined wear value to determine the brightness, If possible, keep the color temperature and the operating time of the display constant over a longer period of time. The display of an image file via averaged red, green, blue image data are then corrected in the further operation of the display with the mentioned correction signals. A pixel-specific wear analysis and a corresponding image point individual correction of wear is not provided. In the context of the previously known method can thus not be discussed the different pixel load.

From the DE 43 34 640 A1 It is known in connection with the above-described problem, to bring so-called inverse images by a corresponding inverse circuit when reaching defined thresholds automatically display instead of the aforementioned screensaver. In this case, the display or the inverse switching of the respectively displayed image can be effected as a function of time specifications or other specifiable parameters. An analysis or detection of pixel wear is not provided here.

spending From this prior art, the invention is based on the object a weary one Display or a method for operating such a display to deal with that over a longer one Period a consistent image quality can be achieved or the life of the display can be extended.

The solution This object is achieved by a method according to claim 1 or 2 or with a display according to claim 28. Advantageous embodiments of the invention will become apparent according to the dependent claims 3 to 27 and 29.

As already mentioned, exists with weary ones Displays, especially plasma displays, the problem that certain Subareas more often or be used more intensively and thus the monitor by a so-called Burning damaged can be. About that In addition, it should be noted that the wear of the phosphor with respect to Basic colors red, green and blue represents different, so the wear of the primary colors is different. Due to the use of the method according to the invention the effects described above are eliminated or mitigated and even a possibility created to compensate for the partial wear or repair. For this purpose, within the scope of the invention by means of each pixel uniquely assigned memory element, the operating time and operating intensity separately after the basic colors red, green and blue and a pixel wear value for each pixel a pixel wear value proportional parameter stored.

through This data can then be a pixel - individual correction of to be displayed image data with the aim of the wear of the plasma display to reduce, balance or avoid. It should be noted, in a typical plasma color display, the refresh rate is usually at 60 Hz, with resolutions from 1280 × 780 Pixels or higher be used so that at a color depth of 8 bits per color one permanent Data flow of at least 177 MB per second is incurred. This data stream must then processed and stored for example by integration become. The value to be stored is then significantly more than 8 bits per color. Already the simple adding up of an 8 bit color value over one Period of 4 minutes needed a memory area of 22 bits per color point. If the memory value not only read but also must be written in This example requires a data stream of 1.5 GB per second.

The Invention solves the problem of the significant data stream to be processed an intelligent data management.

For this is according to claim Figure 1 shows the permanent integration of pixel wear for each single pixel of the determination of the resulting Pixel correction values complete decoupled, allowing a quick cycle to determine the current Pixel wear is ready and a much slower cycle with accordingly Reduced processor performance to determine the pixel-individual Correction values can be used. The decoupling of the cycles and in particular the waiver of a permanent or synchronous Calculation of the correction values makes an effective contribution Reduction of the processor load and the amount of data to be processed represents.

It has also proved to be advantageous when for inventive method a two-stage memory element is used, which is a volatile and a non-volatile one Memory includes. The use of the volatile memory is due the speed of this memory element in technical terms offered. About that Beyond are volatile Memory elements cheaper than nonvolatile Memory elements. Of course So the two solutions become Storage management and data management Ideally in combination operated together.

In the context of the invention, the volatile memory element is not only used to increase the available memory space, but rather used as an overflow for processing the described considerable amount of data. Thus, in the context of the invention, in a first storage step, the resulting pixel wear values are first written into the volatile memory and only transferred to the nonvolatile memory in a second memory step wear. With proper understanding of disk space management, it can be assumed that the storage cycles discussed above are decoupled from one another and run asynchronously.

there It has proven to be advantageous to the data at shutdown the display does not ensure so that the components of the Invention no current-retaining measure such as e.g. a buffer battery need. The resulting inaccuracy can be neglected. Otherwise, a continuous data transfer from the volatile Memory in the non-volatile Memory performed during operation of the display.

At the Turning on the display will then in a first step the in the nonvolatile memory stored data in the volatile memory written back, to access these data in the access for the wear-reduced Operation of the display required memory to write.

In Advantageous configuration, the display is undamaged when switching of the not yet completed process of writing back the data in the volatile Memory immediately, but first without corresponding correction of the image data, put into operation.

In In practice, it proved to be advantageous if as volatile Memory element one or more SDRAM devices are used and as non-volatile Memory element one or more flash devices are used.

Next the use of a volatile and a non-volatile one Memory element, it has proved to be advantageous if the amount of data to be processed by appropriately processed data is reduced. This can be done for example by that reduced the accuracy of each recorded pixel wear values is, for example, the least significant bit, the so-called "Lowest Significant bit "-" LSB "not saved or instead of an absolute value that represents the current pixel wear value, a difference value between the respective pixel wear value and is stored at a predetermined maximum pixel wear value. hereby results in a reduction of the stored data volume insofar, because the difference value is usually will be less than the absolute value to be stored otherwise.

Around on the different wear characteristics of the phosphor elements in the basic colors red, green and to enter into blue, it proved useful when the intensity of the operation the individual pixels individually for each pixel or in sections separately for each of the primary colors red, green and blue is recorded.

In a further process step then takes place in dependence a record of the data described above the image data to be displayed as a function of reaching predeterminable thresholds, wherein the increase and or decrease the intensity the display of the individual pixels automatically, interactively and / or manually can be done.

In again advantageous embodiment can be used as a repair measure for a weary Display a correction image are generated, the display of which leads, that the individually different pixel wear values a general level of wear be raised. The plasma display is displayed accordingly the correction image evened out, and preferably the original Color temperature of the display restored.

Also the display of the correction image can be dependent on predetermined Thresholds automatically, be made interactive and / or manually.

Around the above explained Repair of the plasma display or the homogenization of the pixel wear values speed it may be useful, at least some selected pixels with a maximum or at least increased image brightness.

Around the above explained To be able to make corrections it makes sense if the memory element required for recording the pixel wear values a logic element is assigned to that provided for display Red, green and Blue image data with correction data generated by this logic element added and the display in the further corrected with the accordingly Image data is controlled.

The Correction data are due to the evaluation of the in the Display assigned memory element deposited pixel wear values and / or determined from characteristic fields. The generation of the correction values does not have to be permanent but can be done at intervals or timed done. It is sufficient, if the correction values are generated approximately several times per hour and with these correction values until the next determination of the correction values is working. This measure represents an effective method, the required processing speed to reach. The cycles for storing the pixel wear values and their integral summation is thus decoupled from the determination the correction data.

The Determining the correction data can, of course, depending on of other predetermined parameters, such as the individual phosphor characteristic of the individually used display, the permissible total brightness of the Displays or the overall brightness of the display individually separated according to the basic colors red, green and blue. The operating temperature of the individual display as well as the color temperature are further Parameters related to the determination of the correction data from the mentioned Logic considered can be.

The inventive method can be used to advantage, already existing Retrofit displays, in particular plasma displays, by these displays retrospectively Inventive memory element and a corresponding logic element is assigned, wherein in one first step, an evaluation of the individual state of wear of the retrofitted Displays takes place and further made a first correction step becomes. Thereafter, according to what has been described above in a wear-resistant Continuous operation passed become.

It has also proved to be advantageous that the display about in terms of image resolution scalable and thus the individual quite in the operating time changing conditions is customizable.

When additional or alternative correction option a plasma pulse generator assigned to the display can be used, by transmitting the correction data specified by the logic directly to the plasma pulse generator and in the plasma pulse generator in response to this correction data a special, in particular pixel-individual, brightness control the pixels of the display takes place and incidentally at the RGB input of Displays the otherwise unchanged Image data is present.

The inventive method can thereby be advantageous with the known methods for wear-preserving Operation of such displays are operated, wherein it is proved to be advantageous when the inventive method downstream or operated as a subordinate control loop.

The inventive method is advantageous in conjunction with a wear-prone display according to the characteristics of claim 28 used. This wear-prone display draws characterized in that each pixel a storage element for detecting associated with the individual pixel wear values and by means of a Logic elements from these pixel wear values corrected RGB image data generated and placed at the input of the display.

alternative or additionally For example, the plasma pulse generator of the weary display may be as above already described pixel-individual brightness control of the display.

The Invention will be explained in more detail below with reference to several embodiments. In schematic Show presentation:

1 : a plasma display panel (PDP) with memory and logic element in a block diagram,

2 : a functional diagram for the data transfer between the logic element and the memory element,

3 : a process diagram for determining the corrected image data in the logic element,

4 : a further method diagram for determining the corrected image data in the logic element,

5 : An alternative modulation of the plasma pulse generator of a display in a block diagram.

1 shows in a block diagram a weary display 1 , which in the present embodiment is a so-called plasma display panel, to be called PDP for short. the display 1 stands with a logic element 2 , such as an ASIC or other integrated circuit IC, and a memory element 3 in data connection. The logic element 2 is additionally a parameter memory 4 assigned, which can either also consist of a non-volatile data memory or alternatively also from an input panel with a connected memory, with the then from the logic element 2 to be evaluated parameter values in the, the logic element 2 assigned, parameter memory 4 can be maintained. In the parameter memory 4 can be about the individual phosphor characteristics of the PDP display 1 be filed.

That the display 1 associated memory element 3 consists of a volatile memory 5 and a nonvolatile memory 6 , This is the volatile memory 5 SDRAM devices and nonvolatile memory 6 around one or more flash memories.

In the memory element 3 is every pixel of the display 1 a fixed storage space or assigned a defined memory address. In the memory element 3 For each pixel, individual pixel wear values R *, G *, B * are written separately for each pixel according to the primary colors red, green and blue. The pixel-individual pixel wear values R *, G *, B * are in a first storage step in the volatile memory 5 written and continuously during operation in the non-volatile memory 6 overwritten. The buffering of the non-volatile memory 6 with a volatile memory 5 is required due to the considerable amount of data required in technical and economic terms.

the display 1 is used to display image data, ie, for example, in a plasma TV, the display of a TV station supplied pixel data R, G, B. The pixel data R, G, B are also transmitted separately to the three primary colors red, green, blue, so that also with respect to the pixel data R, G, B between the three primary colors. In contrast to conventional displays, the display according to the invention 1 not with the pixel data transmitted by the television station but rather with corrected pixel data R ', G', B '. The corrected pixel data R ', G', B 'are from the digital logic element 2 taking into account the in the parameter memory 4 applied parameters, such as the individual phosphor characteristic of the display 1 , and in the memory element 3 applied pixel wear values R *, G *, B *.

The storage of the individual pixel wear values R *, G *, B * and the interplay of memory element 3 and logic element 2 is in 2 shown in more detail.

As already mentioned, the memory element comprises 3 a volatile memory 5 and a nonvolatile memory 6 , In this case, the pixel-specific pixel wear values R *, G *, B *, which are proportional to the operating time and intensity of the operation of the respective pixel, are initially in the volatile memory as volatile pixel wear values R ^f , G ^f and B ^f 5 written. In the sense of an overflow, the more significant bits of the pixel wear values R ⁿ , G ⁿ and B ^{n are} stored in the non-volatile memory 6 written. R ^kor , G ^kor or B ^kor .

These are the in the memory elements 5 and 6 written pixel wear values are continuously integrated over the operating time of the respective pixel by means of a corresponding adder and generated from these integral values, such as R ^int then real Bildpunkverschleißwerte R ^v , G ^v and Bv, which then depending on valence in the volatile memory 5 as R ^vf , G ^vf and B ^vf or in the nonvolatile memory 6 as R ^vn , G ^vn and B ^vn stored and the previous value R ^int G ^int and B ^int reset. From the stored values, a pixel-specific correction signal R ^kor , G ^kor or B ^{kor is determined} by means of the logic element.

By means of these correction signals are then, as already in connection with 1 mentioned, the corrected pixel data R ', B' and G 'determined.

Furthermore, the logic element represents 2 sure that when you turn on the display 1 in the non-volatile memory 6 applied data first in the volatile memory 5 be written back. Of course, as long as initially be driven with an uncorrected display display.

The logic element 2 thus determines, taking into account the in the parameter memory 4 stored parameter values pixel-individual correction values R ^kor , G ^kor or g ^kor , wherein the determination of these correction values is not continuous but clocked, that is approximately at defined intervals or when exceeding predetermined thresholds.

It is therefore possible to distinguish carefully between the cycles for determining the corrected pixel data R ', B' and G 'and the integration cycle for determining the pixel wear values R ^int , G ^int and B ^int .

According to 3 be processed by means of this correction data R ^kor G ^cor or B ^kor, the predetermined pixel data R, G, B and finally the display 1 with the corrected pixel data R ', G', B 'acted upon.

An example of the determination of the corrected pixel data is shown in the flowchart in FIG 3 shown in detail.

3 shows the processing of a pixel value for the red channel of a cell.

First, the actual image point value R is detected and, in addition to this value, a variable representing the current image brightness via a brightness controller 10 so that the brightness-adjusted actual value R ^h is available. This brightness-adjusted actual value R ^h was determined by means of an integrator 11 integrated in a loop to an integrated pixel wear value R ^int 'From this integrated pixel wear value R ^int is then determined by means of the logic element 2 a correction value R ^kor determined, which can have a positive or a negative sign depending on the individual pixel wear, which is to be understood that an increase or a reduction of the pixel wear can be specified for the correction value. This correction value R ^kor is then applied to another adder 12 given. At this further adder 12 In addition, the predetermined to be displayed pixel signal R is applied.

By adding the value R to the individual pixel correction value R ^kor , a corrected pixel value R 'is finally generated and applied to the display 1 switched.

In 4 the determination of the corrected pixel value R ', which is ultimately to be displayed on the display, is shown in more detail again as a process diagram. As shown in 4 is, as already mentioned, first offset the actual value with a current brightness value, so that a brightness-corrected pixel value R ^{h is} considered as the actual value. The value R ^h is integrated with the already hastily stored pixel wear values R ^vf and stored in the volatile memory element as a volatile pixel wear value R ^vf . According to another parallel loop is constantly checked whether a recalculation of the correction data R ^{kor is} required, or whether it can be continued with the previous correction data. In addition, in another parallel loop, it is ensured that the fugitive pixel wear values R ^{v f are} continuously written to the nonvolatile memory as non-volatile pixel wear values R ^{v n} .

Incidentally, from the correction values R ^kor determined in accordance with the above explanations, the image point value R 'to be finally applied to the display is generated in the simplest way by addition with the optionally brightness-corrected actual value R ^h .

According to 5 may alternatively or additionally the digital logic element 2 the plasma display 1 associated plasma pulse generator 13 the pixel correction values R ^kor , G ^kor , B ^kor generated in accordance with the above statements are transferred directly. In this version, the digital logic element drags 2 the pixel data R, G, B given by the original image signal without any change directly to an RGB input 14 of the display 1 by. This allows finer gradations in the pixel-individual brightness control of the plasma display 1 be made.

The above is thus a method and a device for wear-preserving operation of a weary display 1 , in particular a plasma display described, which is characterized in that a pixel-individual equalization of the wear level of the display 1 taking into account the individual parameters of the plasma display, this method being supported by intelligent memory and data management.

1

display

2

logic element

3

storage element

4

parameter memory

5

volatile Storage

6

nonvolatile Storage

10

brightness control

11

adder

12

Another adder

13

Plasma pulse generator

14

RGB input

R G, B

Pixel data

R ^h , G ^h , B ^h

brightness corrected Pixel values

R ^kor , G ^kor , B ^kor

 Pixel correction values

R ', G', B '

corrected Pixel values

R * G *, B *

Saved Pixel wear values

R ^vf , G ^vf , B ^vf

Volatile stored Pixel wear values

R ^{vn, vn} G, B ^{v n}

Non-volatile stored Bildpunktver

schleißwerte

R ^int , G ^int , B ^int

integrated Pixel wear values

Claims (8)

Worn display ( 1 ), in particular a plasma display, an LCD display, an LED wall or organic display to which a logic element ( 2 ) and a memory element ( 3 ), wherein the memory element ( 3 ) a volatile and a nonvolatile memory ( 5 and 6 ) and in the memory element ( 3 ), preferably to each pixel, an image point individual pixel wear value (R ^int , G ^int , B ^int ) and / or a characteristic proportional to these pixel wear values, preferably separately for each of the three primary colors red, green or blue, which is shown on the display ( 1 ) to be displayed pixel data (R, G, B) is stored and after a corresponding evaluation of the Bildpunktverschleißwerte (R ^{in t} , G ^int , B ^int ) or the corresponding parameters in relation to predeterminable parameters by the logic element ( 2 ) each, preferably for each pixel individually, changed or corrected RGB image data (R ', G', B ') to an RGB input ( 14 ) of the display ( 1 ) are created. Display ( 1 ) according to claim 1, characterized in that the display is a plasma pulse generator ( 13 ) for brightness control of the display ( 1 ), wherein the plasma pulse generator ( 13 ) which are transmitted by means of the pixel wear values (R ^int , G ^int , B ^int ) or the proportional characteristics determined in the memory element (R ^kor , G ^kor , B ^kor ), wherein simultaneously at the RGB input ( 14 ) of the display ( 1 ) which otherwise remain unchanged RGB image data (R, G, B). Worn display ( 1 ), in particular a plasma display, an LCD display, an LED wall or an organic display, wherein the display ( 1 ) Has pixels, with a logic element ( 2 ) and with a memory element ( 3 ), wherein the memory element ( 3 ) a volatile memory ( 5 ) and a non-volatile memory ( 6 ), characterized in that for each base color red, green, blue a pixel-individual pixel wear value (R ^int , G ^int , B ^int ) in the volatile memory ( 5 ), wherein the pixel wear value (R ^int , G ^int , B ^int ) an operating time and / or an operating intensity of the respective pixel (R, G, B) of the display ( 1 ), and that per basic color red, green, blue a pixel-individual pixel correction value (R ^kor, G ^kor , B ^kor ) for correcting the respective pixel signal (R, G, B) in the volatile memory ( 5 ), wherein the pixel wear value (R ^int , G ^int , B ^int ) and the pixel correction value (R ^kor G ^kor , B ^kor ) in the same memory cell (R ^vf , G ^{v f} , B ^{v f} ) of the volatile memory ( 5 ) are stored. Worn display ( 1 ), in particular a plasma display, an LCD display, an LED wall or an organic display, wherein the display ( 1 ) Has pixels, with a logic element ( 2 ) and with a memory element ( 3 ), wherein the memory element ( 3 ) a volatile memory ( 5 ) and a non-volatile memory ( 6 ), characterized in that for each pixel per basic color red, green, blue a non-volatile stored pixel wear value (R ^{v n} , G ^{v n} , B ^{v n} ) in the nonvolatile memory ( 6 ), wherein the non-volatile stored pixel wear value (R ^vn , G ^vn , B ^vn ) corresponds to a sum of the higher order bits of a volatile stored pixel wear value (R ^vn , G ^vn , B ^vn ) integrated over the operating time of the pixel. Display ( 1 ) according to one of claims 1 to 4, characterized in that the non-volatile memory ( 6 ) as an overflow past the volatile memory ( 5 ) is switched. Display ( 1 ) according to one of the preceding claims, characterized in that the volatile memory ( 5 ) has one or more SDRAM devices. Display ( 1 ) according to one of the preceding claims, characterized in that the non-volatile memory ( 6 ) has one or more flash devices. Display ( 1 ) according to one of the preceding claims, characterized in that the logic element ( 2 ) is suitable for the direct processing of multiplexed data, for example in connection with the LVDS or DVI formats.