CN101295465B - LED caducity emendation method and device - Google Patents

Abstract

The invention discloses an LED aging correcting method, comprising the following steps: a correction parameter is adopted, and LED display signals are corrected according to the correction parameter. The invention also discloses an LED aging correcting device, comprising an input module which receives display signals and transmits display signals to a processing module, an output module which transmits corrected display signals to an LED illuminating unit, a storing module in which correction parameter and LED working time are stored and the processing module which processes the correction parameter and LED input signals. The invention can automatically correct while-balance deviation, color aberrance and image distortion, etc. problems caused by different aging of various color LEDs, and can automatically correct the display capability distortion caused by different aging of LED without stopping the work of LED display screens. The LED aging correcting method which can lead LED display screens to still keep white-balance accuracy, vivid color and accurately restored images after a long-time working and can be widely applied to big outdoor LED display screens and constant-working LED display screens.

Description

LED aging correction method and device

Technical field

The present invention relates to the LED display device, relate in particular to a kind of LED aging correction method and device.

Background technology

Along with the development of modern LED Large Screen Display Technology, technology such as pointwise correction and white balance calibration have made LED display have low aberration, high chroma homogeneity, gray scale to meet characteristics such as human eye law of perception and white balance be accurate, can accurately go back original image.But because various primary-color LED chip material differences, cause the old and feeble curve of each primary-color LED inconsistent, after working for a long time, the inconsistent smooth output attenuatoin meeting of each primary colours makes original calibrated white balance depart from correct status, the color distortion can appear in display screen, situations such as image fault have a strong impact on the display effect of LED display.

The fraction manufacturer can be after the serious change of the display performance of LED display be bad, reclaim and regulate current-limiting resistance recalibration white balance, this be applicable to small-sized or movably, LED display that need not continuous working, but still be the engineering arduousness, process is loaded down with trivial details, to large-scale outdoor LED display screen and need the display screen of continuous working all inapplicable.

Summary of the invention

The object of the present invention is to provide a kind of LED aging correction method, be intended to solve in the prior art since LED display after work for a long time, the inconsistent smooth output attenuatoin of each primary colours makes white balance depart from correct status, and the problem of color distortion, image fault appears in display screen.

A kind of LED aging correction method that the present invention proposes comprises step: call old and feeble correction matrix;

LED shows signal and old and feeble correction matrix multiplied each other proofread and correct the LED shows signal; Described old and feeble correction matrix is

$\left[\begin{array}{ccc}\frac{1}{M}\exp \left(a_{R}t\right)& \frac{1}{M}\exp \left(a_{G}t\right)& \frac{1}{M}\exp \left(a_{B}t\right)\end{array}\right],$

Wherein t is the LED working time, y _R, y _G, y _BBe defined as redness, green, the old and feeble curve of the index of blue led, y _R=exp (a _RT), y _G=exp (a _GT), y _B=exp (a _BT), M=Max[y _Ry _Gy _B], M is y _R, y _G, y _BMaximal value, a _RBe red old and feeble coefficient, a _GBe green old and feeble coefficient, a _BIt is blue old and feeble coefficient;

Continued case according to LED proofreaies and correct judges whether to refresh the new LED working time that is used for computing;

Said method also comprises the time point that whether arrives aging correction for the first time according to the LED working time, judges whether that LED is carried out aging to be proofreaied and correct.

Said method also comprises the renewal to old and feeble correction matrix.

The present invention proposes a kind of LED aging correction device of realizing above-mentioned LED aging correction method simultaneously, and described device comprises: the processing module that the LED shows signal is proofreaied and correct; Receive shows signal and send the load module of processing module to; Shows signal after proofreading and correct is issued the output module of LED luminescence unit; The memory module of storage correction parameter; Refresh the refresh module of LED working time, the LED working time after refreshing is stored in the memory module; Wherein, described correction parameter comprises old and feeble correction matrix, and the described LED shows signal is proofreaied and correct is that LED shows signal and old and feeble correction matrix are multiplied each other, and described old and feeble correction matrix is

$\left[\begin{array}{ccc}\frac{1}{M}\exp \left(a_{R}t\right)& \frac{1}{M}\exp \left(a_{G}t\right)& \frac{1}{M}\exp \left(a_{B}t\right)\end{array}\right],$

Wherein t is the LED working time, y _R, y _G, y _BBe defined as redness, green, the old and feeble curve of the index of blue led, y _R=exp (a _RT), y _G=exp (a _GT), y _B=exp (a _BT), M=Max[y _Ry _Gy _B] M is y _R, y _G, y _BMaximal value, a _RBe red old and feeble coefficient, a _GBe green old and feeble coefficient, a _BIt is blue old and feeble coefficient.

Above-mentioned LED aging correction device also comprises with external unit and being connected, and receives the interface module of the correction parameter that is used to upgrade.

The invention has the beneficial effects as follows, it can depart from from the white balance that the inconsistent aging of each primary-color LED of normal moveout correction causes, the color distortion, situations such as image fault, need not heavy dismounting and carrying, even the work that need not to stop LED display just can become bad from the display performance that the inconsistent aging of normal moveout correction LED causes, can be widely used on the LED display of large LED outdoor display screen and continuous working, make LED display still keep white balance accurate after the work for a long time, color is true to nature, accurately goes back original image.

Description of drawings

Fig. 1 is the schematic flow sheet of a kind of LED aging correction method provided by the invention;

Fig. 2 is the schematic flow sheet of a kind of LED aging correction method of providing of another embodiment of the present invention;

Fig. 3 is the structural representation of a kind of LED aging correction device provided by the invention;

Fig. 4 is the structural representation of a kind of LED aging correction device of providing of another embodiment of the present invention;

Fig. 5 is the structural representation of a kind of LED aging correction device of providing of further embodiment of this invention.

Embodiment

The present invention proposes a kind of LED aging correction method, and as shown in Figure 1, described method comprises:

Step S11 calls correction parameter;

Step S21 proofreaies and correct the LED shows signal according to correction parameter.

Known under nominal working conditions, the light output of LED in mission life meets the old and feeble curve of following index

y＝exp(-at)

Wherein a is old and feeble coefficient, and numerical value is generally 7 * 10 ^-6～7 * 10 ^-5Between, t is the working time, unit is hour.

Like this, redness, green, the old and feeble curve of the index of blue led is respectively:

y _R＝exp(-a _Rt)，

y _G＝exp(-a _Gt)，

y _B＝exp(-a _Bt)，

Above-mentioned old and feeble correction matrix is

$\left[\begin{array}{ccc}\frac{1}{M}\exp \left(a_{R}t\right)& \frac{1}{M}\exp \left(a_{G}t\right)& \frac{1}{M}\exp \left(a_{B}t\right)\end{array}\right],$ M＝Max[y _R?y _G?y _B]，

M is y _R, y _G, y _BMaximal value, wherein a is old and feeble coefficient, a _RBe red old and feeble coefficient, a _GBe green old and feeble coefficient, a _BIt is blue old and feeble coefficient.

To LED shows signal and old and feeble correction matrix

Carry out computing, the matrix operation logical expressions:

$\left[\begin{array}{c}R\\ G\\ B\end{array}\right]\left[\begin{array}{ccc}\frac{1}{M}\exp \left(a_{R}t\right)& \frac{1}{M}\exp \left(a_{G}t\right)& \frac{1}{M}\exp \left(a_{B}t\right)\end{array}\right]\left[\begin{array}{ccc}\exp (-a_{R}t)& \exp (-a_{G}t)& \exp (-a_{B}t)\end{array}\right]=\frac{1}{M}\left[\begin{array}{c}R\\ G\\ B\end{array}\right],$

Wherein R, G, B are respectively the red, green, blue shows signal of LED, move old and feeble correction matrix and handle three primary colours R, and G, the B shows signal promptly is that the R shows signal multiply by

The G shows signal multiply by

The B shows signal multiply by The LED light output shows signal of R shows signal is

The LED light output shows signal of G shows signal is

The LED light output shows signal of B shows signal is

After carrying out multiplying, compare the just brightness of same ratio before the R of LED, G, B three primary colours shows signal and the input and reduce, brightness is reduced to original

The situation that white balance departs from do not occur, the display screen of LED still can be gone back original image accurately.

The another kind of embodiment of the present invention as shown in Figure 2, so step S11, S21 and last embodiment are similar, do not give unnecessary details, also comprise step S01, whether arrive the time point of old and feeble correction for the first time according to the LED working time, judge whether LED is carried out the aging correction.Do not carry out aging after the LED work at once and proofread and correct, reach predetermined old and feeble correction time of first time point for example 500 hours the time, just begin to carry out the aging correction when the LED working time.Behind the step S21, also comprise step S31, the duration value according to LED proofreaies and correct judges whether to refresh the new LED working time that is used for computing, and the step of proofreading and correct the LED shows signal according to correction parameter is to carry out according to the LED working time after refreshing.After LED arrival is put for the first time and begin to proofread and correct correction time, LED carries out computing with the LED working time of putting this correction time and proofreaies and correct, after the time of proofreading and correct of putting with last correction time reaches 100 hours, again read the LED working time, carry out computing according to the new LED working time, the aging of proofreading and correct LED again changes.Guaranteed that LED still can accurately go back original image under situation about working long hours.

Be illustrated in figure 3 as a kind of LED aging correction device structural representation provided by the invention, comprise the load module 5 that receives shows signal and send processing module to, the output module 6 that the back shows signal is issued the LED luminescence unit will be proofreaied and correct, the memory module 2 of storage correction parameter is carried out old and feeble processing module 1 of proofreading and correct to the LED shows signal.

During work, at first power up the initialization LED display, the red, green, blue shows signal enters processing module 1 by load module 5, and processing module 1 judges whether the LED working time arrives the some correction time first time.When arrival is put for the first time correction time, processing module 1 reads the old and feeble correction matrix and the LED working time of memory module 2 storages, old and feeble correction matrix and LED input shows signal are carried out multiplying, and the LED shows signal after will handling at last is by output module 6 outputs.Show on display screen through treatment for correcting LED shows signal.

As Fig. 4 the structural representation of the another kind of embodiment of the present invention is shown, the load module 5 of present embodiment, output module 6, memory module 2 and processing module 1 are similar with last embodiment, also comprise the refresh module 3 that refreshes the LED working time.

After the duration of proofreading and correct reaches 100 hours, refresh module 3 reads the clock signal of the LED clock module of prior art again, the LED working time of refreshing also transfers to memory module 2 and stores the LED working time again, the LED working time that processing module 1 reads in the memory module 2 is once more carried out treatment for correcting, has guaranteed that LED display still can go back original image accurately under situation about working long hours.

The structural representation of another embodiment of the present invention is shown as Fig. 5, the LED aging also comprises interface module 4 than equipment, interface module 4 external computer (not shown), update stored in old and feeble correction matrix and LED working time in the memory module 2 by computer, when the increase of LED along with the working time, during the aging curvilinear motion,, make correction parameter can adapt to new old and feeble curve by upgrading correction matrix.The old and feeble curve of dissimilar LED can upgrade by interface module 4, has realized that the aging of dissimilar LED is proofreaied and correct.

When LED display meets accident outage, the working time of the LED that memory module 2 is put down in writing is because outage produces mistake, what store is the preceding working time of outage, can re-enter correct correction parameter by interface module 4, and image is accurately reduced again.

Preferably, described memory module 2 adopts nonvolatile memory, and outage back data can not lost.

Preferably, processing module 1, load module 5, output module 6 and memory module 2 adopt FPGA (Field Programmable Gate Array) integrated circuit.

Claims (5)

1. LED aging correction method comprises step:

Call old and feeble correction matrix;

LED shows signal and old and feeble correction matrix multiplied each other proofread and correct the LED shows signal; Described old and feeble correction matrix is

$\left[\begin{array}{ccc}\frac{1}{M}\exp \left(a_{R}t\right)& \frac{1}{M}\exp \left(a_{G}t\right)& \frac{1}{M}\exp \left(a_{B}t\right)\end{array}\right],$

Wherein t is the LED working time, y _R, y _G, y _BBe defined as redness, green, the old and feeble curve of the index of blue led, y _R=exp (a _RT), y _G=exp (a _GT), y _B=exp (a _BT), M=Max[y _Ry _Gy _B], M is y _R, y _G, y _BMaximal value, a _RBe red old and feeble coefficient, a _GBe green old and feeble coefficient, a _BIt is blue old and feeble coefficient;

Continued case according to LED proofreaies and correct judges whether to refresh the new LED working time that is used for computing.

2. LED aging correction method as claimed in claim 1 is characterized in that, also comprises the time point that whether arrives aging correction for the first time according to the LED working time, judges whether that LED is carried out aging to be proofreaied and correct.

3. LED aging correction method as claimed in claim 1 is characterized in that, also comprises the renewal to old and feeble correction matrix.

4. a LED aging correction device is proofreaied and correct the LED luminescence unit, it is characterized in that, comprising:

The processing module that the LED shows signal is proofreaied and correct;

Receive shows signal and send the load module of processing module to;

Shows signal after proofreading and correct is issued the output module of LED luminescence unit;

The memory module of storage correction parameter;

Refresh the refresh module of LED working time, the LED working time after refreshing is stored in the memory module;

Wherein, described correction parameter comprises old and feeble correction matrix, and the described LED shows signal is proofreaied and correct is that LED shows signal and old and feeble correction matrix are multiplied each other, and described old and feeble correction matrix is

$\left[\begin{array}{ccc}\frac{1}{M}\exp \left(a_{R}t\right)& \frac{1}{M}\exp \left(a_{G}t\right)& \frac{1}{M}\exp \left(a_{B}t\right)\end{array}\right],$

Wherein t is the LED working time, y _R, y _G, y _BBe defined as redness, green, the old and feeble curve of the index of blue led, y _R=exp (a _RT), y _G=exp (a _GT), y _B=exp (a _BT), M=Max[y _Ry _Gy _B], M is y _R, y _G, y _BMaximal value, a _RBe red old and feeble coefficient, a _GBe green old and feeble coefficient, a _BIt is blue old and feeble coefficient.

5. a kind of LED aging correction device as claimed in claim 4 is characterized in that, also comprises:

Be connected with external unit, receive the interface module of the correction parameter that is used to upgrade.

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