A multi-frame overdrive compensation method for OLED screens

Abstract

The present invention discloses a multi-frame overdrive compensation method for an OLED screen, comprising the following steps: S1: single-frame picture information cache; S2: transformation vector estimation; S3: vector compensation picture; S4: multi-frame overdrive compensation. The present invention can apply an overdrive compensation method based on multi-frame picture data by only caching the single-frame picture data of the previous frame. On the one hand, it can ensure a better overdrive compensation effect and reduce the phenomenon of picture smear, and on the other hand, it does not need to store multi-frame picture data, reducing the SRAM / DDR storage pressure and the power consumption of reading and writing data.

Description

Technical Field

[0001] The present invention belongs to the field of display driving, and in particular relates to a multi-frame over-driving compensation method for an OLED screen. Background Art

[0002] With the widespread application of OLED screens in consumer electronic products such as mobile phones, pads, and laptops, the demand for optical compensation technologies for OLED pixel circuits is increasing. Because the driver tube used in the OLED pixel circuit has internal defects and interface defects in the gate insulation layer, the threshold voltage Vth of the pixel circuit light-emitting will drift, which will lead to the so-called "hysteresis effect" of the pixel circuit light-emitting. This effect will cause obvious "text smearing" phenomenon in the black background reading scene. In view of this, many display driver chips (DDICs) have integrated overdrive compensation (ODC) algorithms.

[0003] The existing ODC method mainly determines the compensation value of the RGB sub-pixel at the coordinate by considering the brightness change of two adjacent frames or multiple frames at the same pixel physical coordinate.

[0004] However, due to the "hysteresis effect" of OLED pixel circuits, multiple frames of images usually need to be compensated continuously to form a stable sensory effect. The currently proposed multi-frame ODC solutions all require caching more than 2 frames of image data as reference information, which puts huge pressure on the storage resources of DDIC and is generally considered unacceptable.

[0005] Therefore, a solution is needed that can solve multi-frame ODC within one frame of data storage resources, so that it is feasible to implement the solution on the limited hardware resources of DDIC. Summary of the invention

[0006] In view of this, one of the objects of the present invention is to provide a multi-frame overdrive compensation method for an OLED screen, which can apply an overdrive compensation method based on multi-frame picture data by only caching the single-frame picture data of the previous frame. On the one hand, it can ensure a better overdrive compensation effect and thus reduce phenomena such as picture ghosting. On the other hand, there is no need to store multi-frame picture data, thereby reducing SRAM / DDR storage pressure and power consumption of reading and writing data.

[0007] To achieve the above object, the present invention provides a multi-frame overdrive compensation method for an OLED screen, comprising the following steps:

[0008] S1: Single frame information cache: cache the display information of the previous frame;

[0009] S2: transformation vector estimation: obtaining transformation vector parameters according to the difference between the display picture information of the previous frame and the picture information to be displayed of the current frame;

[0010] S3: vector compensation picture: inversely inferring the estimated value of display picture information of at least one preceding frame before the previous frame according to the transformation vector parameter;

[0011] S4: multi-frame over-drive compensation: over-drive compensation is performed on the to-be-displayed picture information of the current frame according to the display picture information of the previous frame and the estimated value of the display picture information of the previous frame.

[0012] Preferably, step S2 and step S3 use at least one transformation model to obtain the transformation vector parameter and inversely infer the display picture information estimation value;

[0013] The transformation model includes at least one of a motion estimation model, a change detection model, and a touch sliding estimation model.

[0014] Preferably, in step S4, the overdrive compensation is a method of compensating the to-be-displayed picture information of the pixel according to brightness changes corresponding to multiple frames of displayed picture information of each pixel.

[0015] Preferably, step S1 further comprises: encoding the display screen information before caching;

[0016] Step S2 also includes a decoding step before obtaining the display screen information of the previous frame.

[0017] The beneficial effects of the present invention are:

[0018] The present invention can apply the overdrive compensation method based on multi-frame picture data by only caching the single-frame picture data of the previous frame. On the one hand, it can ensure a better overdrive compensation effect to reduce the phenomenon of picture ghosting, etc. On the other hand, there is no need to store multi-frame picture data, reducing the SRAM / DDR storage pressure and the power consumption of reading and writing data. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the overall process of a multi-frame over-driving compensation method for an OLED screen disclosed in the present invention;

[0021] Figure 2 and Figure 3 is a schematic diagram of Embodiment 1 of the present invention;

[0022] Figure 4 and Figure 5 is a schematic diagram of a second embodiment of the present invention;

[0023] Figure 6 and Figure 7 This is a schematic diagram of Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The multi-frame overdrive compensation (Multiframe ODC, MF-ODC) mentioned in the present invention refers to overdrive data compensation for pixel data at the same position in multiple consecutive frames in time. The purpose of the present invention is to estimate the transformation vector parameters Image_Vector[T-1] (corresponding to the T-1 frame) of the graphics in the display screen based on the data application model of Frame[T-1] of the previous frame and Image_in[T] of the current frame, and further reversely deduce Image_Vector[Ti] (corresponding to the Ti-th frame of the previous sequence, i≥2), and then only Image_in[T] (and / or Frame[T-1]) and the transformation vector parameters can be used on the time axis to calculate the screen data of the previous frame Frame[Ti], without storing multiple frames of screen data, reducing SRAM / DDR storage pressure and power consumption of reading and writing data.

[0026] A multi-frame overdrive compensation method for an OLED screen disclosed in this embodiment includes the following steps:

[0027] S1: Single frame image information cache: cache the display image information of the previous frame, that is, in the T-1 frame, cache the to-be-displayed image information Image_in[T-1] of the previous frame and use it as the display image information Frame[T-1] in the current frame;

[0028] S2: Transformation vector estimation: Obtain the transformation vector parameter Image_Vector[Ti] according to the difference between the display image information Frame[T-1] of the previous frame and the to-be-displayed image information Image_in[T] of the current frame, as shown in formula (1):

[0029] Image_Vector[Ti]=Estimate_Vector(Image_in[T],Frame[T-1]) (1);

[0030] Wherein: Estimate_Vector represents the estimation method of the transformation model used to obtain the transformation vector parameters, and common transformation models include motion estimation models, change detection models, touch sliding estimation models, etc. Those skilled in the art can arbitrarily select and combine the models well known to the public as needed.

[0031] S3: Vector compensation picture: According to the transformation vector parameter Image_Vector[Ti], the display picture information estimation value Image_Comp[Ti] of at least one preceding frame before the previous frame is inferred, as shown in formula (2):

[0032] Image_Comp[Ti]=Backward_Comp(Image_in[T],Image_Vector[Ti]) (2);

[0033] Wherein: Backward_Comp represents the compensation reconstruction method of the corresponding transformation model (i.e., the vector reconstruction process that is the inverse of the estimation method). The corresponding vector reconstruction processes for the motion estimation model, change detection model, and touch sliding estimation model are motion compensation (MC), affine transform (AT), and direction compensation (DC), respectively.

[0034] S4: Multi-frame overdrive compensation: overdrive compensation is performed on the to-be-displayed picture information of the current frame according to the display picture information of the previous frame and the estimated value of the display picture information of the previous frame, as shown in formula (3):

[0035] Image_out[T]=Image_in[T]+ODC_LUT(Image_in[T],Frame[T-1],Image_Comp[Ti]) (3);

[0036] Wherein: ODC_LUT represents a multi-frame over-drive compensation method. Those skilled in the art may select or combine any one or several multi-frame over-drive compensation methods in the prior art as needed, which will not be described in detail here.

[0037] The overall process is as follows Figure 1Preferably, before and after caching the information of Frame[T-1], encoding and decoding processes are also included (the encoding module and the decoding module correspond to the Encoder and the Decoder in the figure) to further reduce the space requirement.

[0038] The motion estimation model, the change detection model, and the touch sliding estimation model are described in detail below using three embodiments.

[0039] Embodiment 1

[0040] like Figure 2 As shown, when the display screen moves from frame T-1 to frame T, the graphic 1 in the display image is displaced. The estimation method of the transformation model is applied to compare and estimate the two frames of images. If the transformation model includes a motion estimation model, the motion vector can be obtained, that is, the moving direction d_ref and the moving speed v_ref of the graphic 1 can be obtained. In this way, the vector coordinates of the graphic 1 in the previous frame (such as the T-2 frame) can be reversed based on the above two parameters, as shown in FIG. Figure 3 As shown, the estimated value of the display screen information at the T-2 frame can be reconstructed based on the vector coordinates.

[0041] Embodiment 2

[0042] like Figure 4 As shown, when the display screen changes from frame T-1 to frame T, the size of the graphic 2 in the display image changes. The estimation method of the transformation model is applied to compare and estimate the two frames of images. If the transformation model includes a change detection model, the affine transformation parameters can be obtained. Similarly, the affine transformation parameters of the graphic 2 in the previous frame can be inverted, as shown in FIG. Figure 5 As shown, the estimated value of the display screen information at the T-2th frame can be reconstructed based on the affine transformation parameters.

[0043] Embodiment 3

[0044] like Figure 6 As shown, when the display screen is from frame T-1 to frame T, the graphic 3 in the display image is displaced and a touch signal is received. The estimation method of the transformation model is applied to compare and estimate the two frames of images. If the transformation model includes a touch sliding estimation model, it can be determined whether the displacement matches the touch signal. If they match, the coordinates of the graphic 3 in the previous frame can be inferred based on the touch signal, as shown in FIG. Figure 7 As shown, the estimated value of the display screen information at the T-2 frame can be reconstructed based on the coordinates.

[0045] The above embodiments all take the case where only a single type of transformation occurs in the graphics on the screen as an example. In actual application scenarios, the transformation of graphics on the screen may be more complex. Therefore, the transformation model can be combined with multiple existing models for comprehensive judgment and estimation.

[0046] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0047] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-frame overdrive compensation method for an OLED screen, characterized in that: The steps include: S1: Single frame information cache: cache the display information of the previous frame; S2: transformation vector estimation: obtaining transformation vector parameters according to the difference between the display picture information of the previous frame and the picture information to be displayed of the current frame; S3: vector compensation picture: inversely inferring the estimated value of display picture information of at least one preceding frame before the previous frame according to the transformation vector parameter; S4: multi-frame overdrive compensation: performing overdrive compensation on the to-be-displayed picture information of the current frame according to the display picture information of the previous frame and the estimated value of the display picture information of the previous frame; Steps S2 and S3 use at least one transformation model to obtain the transformation vector parameter and inversely infer the display picture information estimation value; The transformation model includes at least one of a motion estimation model, a change detection model, and a touch sliding estimation model.

2. The multi-frame overdrive compensation method according to claim 1, characterized in that: In step S4, the overdrive compensation is a method of compensating the to-be-displayed picture information of the pixel according to the brightness change corresponding to the display picture information of multiple frames of each pixel.

3. The multi-frame overdrive compensation method according to claim 1, characterized in that: Step S1 also includes: encoding the display screen information before caching; Step S2 also includes a decoding step before obtaining the display screen information of the previous frame.

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