KR102668226B1 - Luminance Control Device And Method Of Display Device - Google Patents

Abstract

A luminance control device for a display device according to an embodiment of the present specification includes a display panel 30 having a screen composed of a plurality of pixel lines, and each pixel line including a plurality of pixels; a panel driver 20 that drives the screen; a data analysis unit (11) that analyzes the image data (DATA) to be written on the screen in units of pixel lines and accumulates line current values; and determining an ACL start pixel line (Lx) and a corresponding ACL start timing (Tx) for luminance control based on the cumulative result (CNT) of the line current value, and determining the first frame and the subsequent frame including the ACL start timing. It includes an ACL control unit 12 that controls the luminance on a per-pixel line basis in 2 frames and controls the operation of the panel driver so that the 2-frame average luminance for each line is the same for all pixel lines.

Description

Luminance control device and method of display device {Luminance Control Device And Method Of Display Device}

This specification relates to an apparatus and method for controlling brightness of a display device.

An active matrix type electroluminescence display displays images using light emitting elements included in each pixel. The light emitting device is a current driven device whose amount of light is controlled according to the driving current.

To reduce power consumption in electroluminescent displays, ACL (Automatic Current Limit) technology, which automatically limits screen current according to image data, may be employed. Since this ACL technology controls screen current based on the average luminance value of one screen's worth of image data, it requires a frame memory to store the image data. Such frame memories increase manufacturing costs and limit the thickness of display devices.

Therefore, this specification provides a luminance control device and method for a display device that implements ACL technology without frame memory and solves image quality issues due to ACL application.

A luminance control device for a display device according to an embodiment of the present specification includes a display panel 30 having a screen composed of a plurality of pixel lines, and each pixel line including a plurality of pixels; a panel driver 20 that drives the screen; a data analysis unit (11) that analyzes the image data (DATA) to be written on the screen in units of pixel lines and accumulates line current values; and determining an ACL start pixel line (Lx) and a corresponding ACL start timing (Tx) for luminance control based on the cumulative result (CNT) of the line current value, and determining the first frame and the subsequent frame including the ACL start timing. It includes an ACL control unit 12 that controls the luminance on a per-pixel line basis in 2 frames and controls the operation of the panel driver so that the 2-frame average luminance for each line is the same for all pixel lines.

The apparatus and method for controlling the brightness of a display device according to an embodiment of the present specification implements ACL technology without a frame memory, but can solve image quality issues due to application of ACL.

The effects according to the present invention are not limited to the contents exemplified above, and further various effects are included in the present specification.

1 is a diagram showing a display device according to an embodiment of the present specification.
FIG. 2 is a diagram showing the detailed configuration of the controller shown in FIG. 1.
3 and 4 are diagrams showing a method of controlling luminance of a display device according to a comparative example.
5 and 6 are diagrams showing a method of controlling luminance of a display device according to the first embodiment of the present specification.
7 and 8 are diagrams showing a method of controlling luminance of a display device according to a second embodiment of the present specification.
9 and 10 are diagrams showing a method of controlling luminance of a display device according to a third embodiment of the present specification.
11 and 12 are diagrams showing a method of controlling luminance of a display device according to a fourth embodiment of the present specification.
13, 15, and 17 are diagrams showing the operation of a panel driver for implementing the luminance control method of a display device according to the third embodiment of the present specification.
14, 16, and 18 are diagrams showing the operation of a panel driver for implementing the luminance control method of a display device according to the fourth embodiment of the present specification.

The advantages and features of the present specification and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below and will be implemented in various different forms, but the present embodiments only serve to ensure that the disclosure of the present specification is complete, and that common knowledge in the technical field to which this specification pertains is provided. It is provided to fully inform those who have the scope of the invention, and this specification is only defined by the scope of the claims.

The shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining the embodiments of the present specification are illustrative, and the present specification is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless '~ only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship between two parts is described as 'on top', 'on top', 'at the bottom', 'next to ~', 'right next to' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

First, second, etc. may be used to describe various components, but these components are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical idea of the present specification.

Hereinafter, embodiments of the present specification will be described in detail with reference to the attached drawings. In the following description, if it is determined that a detailed description of a known function or configuration related to the present specification may unnecessarily obscure the gist of the present specification, the detailed description will be omitted.

1 is a diagram showing a display device according to an embodiment of the present specification. And, FIG. 2 is a diagram showing the detailed configuration of the controller shown in FIG. 1.

Referring to FIGS. 1 and 2 , a display device according to an embodiment of the present invention may be an electroluminescence display device.

The electroluminescence display device includes a controller 10, a panel driver 20, and a display panel 30. The controller 10, panel driver 20, and display panel 30 may constitute a luminance control device of the display device.

The display panel 30 is provided with a screen composed of a plurality of pixel lines, and each pixel line includes a plurality of pixels (P). Here, “pixel line” refers not to a physical signal line, but to a collection of pixels (P) and signal lines that are adjacent to each other along one direction. The signal lines are data lines (DL) for supplying the data voltage (Vdata) to the pixels (P), reference voltage lines (RL) for supplying the reference voltage (Vref) to the pixels (P), and pixels It may include gate lines (GL) for supplying a scan signal to (P), and high potential power lines for supplying a high potential pixel voltage (EVDD) to the pixels (P). For ACL application, which will be described later, the reference voltage lines RL may be separated on a pixel line basis.

The pixels P of the display panel 30 are arranged in a matrix form to form a pixel array, providing a screen on which an image is displayed. Each pixel (P) is connected to one of the data lines (DL), one of the reference voltage lines (RL), one of the high potential power lines, and one of the gate lines (GL). can be connected Each pixel (P) may further receive a low-potential pixel voltage (EVSS) from the panel driver 20.

Each pixel P may include, but is not limited to, a light emitting element (EL), a driving TFT (DT), switch TFTs (ST1, ST2), and a storage capacitor (Cst). The driving TFT (DT) and the switch TFTs (ST1, ST2) may be implemented as NMOS, but are not limited to this.

The light emitting element (EL) is a light emitting element that emits light with an intensity corresponding to the pixel current drawn from the driving TFT (DT). The light emitting device (EL) may be implemented as an organic light emitting diode including an organic light emitting layer, or may be implemented as an inorganic light emitting diode including an inorganic light emitting layer. The anode electrode of the light emitting element EL is connected to the second node N2, and the cathode electrode is connected to the input terminal of the low potential pixel voltage EVSS.

The driving TFT (DT) is a driving element that generates pixel current in response to the gate-source voltage. The gate electrode of the driving TFT (DT) is connected to the first node (N1), the first electrode is connected to the input terminal of the high-potential pixel voltage (EVDD) through a high-potential power line, and the second electrode is connected to the second node ( It is connected to N2).

The switch TFTs (ST1 and ST2) are switch elements that set the gate-source voltage of the driving TFT (DT) and connect the second electrode of the driving TFT (DT) to the reference voltage line (RL).

The first switch TFT (ST1) is connected between the data line (DL) and the first node (N1) and is turned on according to the scan signal (SCAN) from the gate line (GL). The first switch TFT (ST1) is turned on during programming for image driving. When the first switch TFT (ST1) is turned on, the data voltage (Vdata) is applied to the first node (N1). The gate electrode of the first switch TFT (ST1) is connected to the gate line (GL), the first electrode is connected to the data line (DL), and the second electrode is connected to the first node (N1).

The second switch TFT (ST2) is connected between the reference voltage line (RL) and the second node (N2) and is turned on according to the scan signal (SCAN) from the gate line (GL). The second switch TFT (ST2) is turned on during programming for image driving and applies the reference voltage (Vref) to the second node (N2). The gate electrode of the second switch TFT (ST2) is connected to the gate line (GL), the first electrode is connected to the reference voltage line (RL), and the second electrode is connected to the second node (N2).

The storage capacitor Cst is connected between the first node N1 and the second node N2 to maintain the gate-source voltage of the driving TFT DT for a certain period of time.

The panel driver 20 drives pixels P included in the screen of the display panel 30. The panel driver 20 includes a data driver driving data lines DL connected to pixels P, a gate driver driving gate lines GL connected to pixels P, and a gate driver driving gate lines GL connected to pixels P. ) and a power driver that drives reference voltage lines (RL) connected to the pixels (P) and high-potential power lines connected to the pixels (P).

The gate driver generates a scan signal (SCAN) under the control of the controller 10, and provides the scan signal (SCAN) to the screen in accordance with the writing timing of the image data (DATA). The scan signal (SCAN) is supplied to the screen through the gate line (GL) and selects the pixel line on which image data (DATA) will be written. The gate driver receives an ACL control signal (ACL-CON) for controlling luminance on a pixel line basis from the controller 10, and the pulse width or pulse position of the scan signal (SCAN) according to the ACL control signal (ACL-CON). can be adjusted on a per-pixel-line basis. The gate driver may be formed directly in a non-display area outside the screen of the display panel 30.

The data driver converts image data (DATA) into data voltage (Vdata) under the control of the controller 10 and provides this data voltage (Vdata) to the screen. Data voltage (Vdata) is supplied to the screen through the data line (DL). The data driver receives an ACL control signal (ACL-CON) for controlling luminance in pixel line units from the controller 10, and can adjust the size of the data voltage in pixel line units according to the ACL control signal (ACL-CON). there is.

The power driver generates a reference voltage (Vref) and a high-potential pixel voltage (EVDD) under the control of the controller 10 and provides them to the screen. The reference voltage (Vref) is supplied to the screen through the reference voltage line (RL), and the high-potential pixel voltage (EVDD) is supplied to the screen through the high-potential power line. The power driver receives an ACL control signal (ACL-CON) for controlling luminance on a pixel line basis from the controller 10, and adjusts the size of the reference voltage (Vref) on a pixel line basis according to the ACL control signal (ACL-CON). It can be adjusted with .

The controller 10 may include a timing control unit and a brightness control unit.

The timing control unit uses the panel driver 20 with reference to timing signals input from the host system, such as the vertical synchronization signal (Vsync), horizontal synchronization signal (Hsync), dot clock signal (DCLK), and data enable signal (DE). Controls the timing of operation.

The brightness control unit can reduce power consumption by limiting the pixel current flowing on the screen without frame memory and protect the pixel circuit from sudden current changes. The luminance control unit analyzes image data (DATA) in pixel line units to implement ACL (Automatic Current Limit) technology, so it does not require one screen's worth of frame memory. The luminance control unit can analyze images using only line memory. The luminance control unit controls the luminance on a pixel line basis in the first frame where ACL starts and the subsequent second frame, but ensures that the 2-frame average luminance for each line is the same for all pixel lines, thereby preventing image quality issues due to ACL application ( In other words, the problem of a difference in brightness being perceived on the screen based on the pixel line where current limitation (brightness control) starts can be solved.

For this purpose, the luminance control unit includes a data analysis unit 11 and an ACL control unit 12 as shown in FIG. 2.

The data analysis unit 11 analyzes image data (DATA) to be written on the screen in units of pixel lines and accumulates line current values. The data analysis unit 11 may derive a 1-line current value from 1 line of image data (DATA) by referring to a look-up table regarding gray level versus current value. The data analysis unit 11 may derive a 1-line current value from image data of a certain gradation value or more among 1 line of image data (DATA). The data analysis unit 11 outputs the cumulative result (CNT) of the line current value while updating it on a pixel line basis.

The ACL control unit 12 determines the ACL start pixel line (Lx) for luminance control and the corresponding ACL start timing (Tx) based on the cumulative result (CNT) of the line current value. If the cumulative result (CNT) of the line current value up to a specific pixel line exceeds a preset threshold, the ACL control unit 12 applies ACL technology starting from the specific pixel line to limit the current (i.e., control luminance). . The ACL control unit 12 determines the ACL start pixel line to which the ACL technology will be applied (see Lx in FIG. 6, etc.) and the corresponding ACL start timing (see Tx in FIG. 6, etc.), and generates a first frame including the ACL start timing. And in the subsequent second frame, the luminance is controlled on a pixel line basis, and an ACL control signal (ACL-CON) is generated to ensure that the 2-frame average luminance for each line is the same for all pixel lines, thereby controlling the operation of the panel driver 20. You can control it.

3 and 4 are diagrams showing a method of controlling luminance of a display device according to a comparative example.

Referring to FIGS. 3 and 4, the luminance control method of a display device according to a comparative example is such that when the cumulative result (CNT) of the line current value in a specific pixel line (Lx) of the Nth frame exceeds a preset threshold, this A specific pixel line (Lx) is determined as the ACL application start line. This luminance control method reduces luminance from the ACL application start line to the last pixel line. For example, if the luminance up to the pixel line immediately before a specific pixel line (Lx) is the current level (CL, 100%), this luminance control method sets the luminance after the specific pixel line (Lx) to the target level (TL, 80%). Immediately reduce to , and apply the target level (TL, 80%) to the N+1 frame and subsequent frames. Accordingly, the luminance of the entire screen changes to the target level (TL, 80%) for current limitation starting from the N+1th frame.

According to this brightness control method, a brightness deviation may be visible on the screen due to sudden brightness limitation based on a specific pixel line (Lx) where current limitation begins.

To alleviate image quality issues when applying such ACL, this specification provides the following various embodiments.

5 and 6 are diagrams showing a method of controlling luminance of a display device according to the first embodiment of the present specification.

Referring to FIGS. 5 and 6, when the cumulative result (CNT) of the line current value in a specific pixel line (Lx) of the Nth frame exceeds a preset threshold, the ACL control unit applies ACL to this specific pixel line (Lx). The start line is determined, and the timing at which a specific pixel line (Lx) will be driven in the Nth frame is determined as the ACL start timing (Tx).

In order to reduce ACL image quality issues, the ACL control unit adjusts the luminance on a per-pixel line basis so that the 2-frame average luminance for each line is the same in all pixel lines in the Nth frame where ACL starts and the N+1 frame that is the subsequent frame. Control.

Specifically, the ACL control unit maintains the luminance of the first line from the Nth frame to the pixel line immediately preceding the ACL start pixel line (Lx) at the current level (CL), and maintains the luminance of the first line from the ACL start pixel line (Lx) to the current level (CL). The luminances are gradually lowered from the current level (CL) to a lower target level (TL). And, the ACL control unit maintains the first line luminance at the target level (TL) in the N+1th frame, and gradually increases the second line luminance from the target level (TL) to the current level (CL). If the 2-frame average luminance for each line is controlled equally for all pixel lines, image quality issues when applying ACL will not be recognized due to the visual integration effect. In addition, the ACL control unit lowers and maintains the entire screen luminance, including the first line luminance and the second line luminance, to the target level (TL) in the N+2 frame and subsequent frames, thereby reducing power consumption through ACL. It can provide reduction and circuit element effects.

Meanwhile, in the luminance control method of the display device according to the first embodiment, the luminance of the current level (CL) is 100% and the luminance of the target level (TL) is 80%, but the technical idea of the present specification is It should be noted that it is not limited to the illustrated values and may cover various numerical modifications.

7 and 8 are diagrams showing a method of controlling luminance of a display device according to a second embodiment of the present specification. The second embodiment has the advantage of reducing the size of the logic algorithm by simplifying the brightness control scheme compared to the first embodiment.

Referring to FIGS. 7 and 8, when the cumulative result (CNT) of the line current value in a specific pixel line (Lx) of the Nth frame exceeds a preset threshold, the ACL control unit applies ACL to this specific pixel line (Lx). The start line is determined, and the timing at which a specific pixel line (Lx) will be driven in the Nth frame is determined as the ACL start timing (Tx).

In order to reduce ACL image quality issues, the ACL control unit adjusts the luminance on a per-pixel line basis so that the 2-frame average luminance for each line is the same in all pixel lines in the Nth frame where ACL starts and the N+1 frame that is the subsequent frame. Control.

Specifically, the ACL control unit maintains the luminance of the first line from the Nth frame to the pixel line immediately preceding the ACL start pixel line (Lx) at the current level (CL), and maintains the luminance of the first line from the ACL start pixel line (Lx) to the current level (CL). The luminances are maintained by lowering them to a target level (TL) lower than the current level (CL). In addition, the ACL control unit maintains the first line luminance at the target level (TL) in the N+1th frame, and maintains the second line luminance at a current level (CL) higher than the target level (TL). If the 2-frame average luminance for each line is controlled equally for all pixel lines, image quality issues when applying ACL will not be recognized due to the visual integration effect. In addition, the ACL control unit lowers and maintains the entire screen luminance, including the first line luminance and the second line luminance, to the target level (TL) in the N+2 frame and subsequent frames, thereby reducing power consumption through ACL. It can provide reduction and circuit element effects.

Meanwhile, in the luminance control method of the display device according to the second embodiment, the luminance of the current level (CL) is 100% and the luminance of the target level (TL) is 80%, but the technical idea of the present specification is It should be noted that it is not limited to the illustrated values and may cover various numerical modifications.

9 and 10 are diagrams showing a method of controlling luminance of a display device according to a third embodiment of the present specification. Compared to the first embodiment, the third embodiment allows the entire screen luminance to gradually converge from the average level (AL) to the target level (TL) during ACL application, thereby preventing flickering from being recognized due to luminance deviation between neighboring frames. There is an advantage to preventing it.

Referring to FIGS. 9 and 10, when the cumulative result (CNT) of the line current value in a specific pixel line (Lx) of the Nth frame exceeds a preset threshold, the ACL control unit applies ACL to this specific pixel line (Lx). The start line is determined, and the timing at which a specific pixel line (Lx) will be driven in the Nth frame is determined as the ACL start timing (Tx).

In order to reduce ACL image quality issues, the ACL control unit adjusts the luminance on a per-pixel line basis so that the 2-frame average luminance for each line is the same in all pixel lines in the Nth frame where ACL starts and the N+1 frame that is the subsequent frame. Control.

Specifically, the ACL control unit maintains the luminance of the first line from the Nth frame to the pixel line immediately preceding the ACL start pixel line (Lx) at the current level (CL), and maintains the luminance of the first line from the ACL start pixel line (Lx) to the current level (CL). The luminances are gradually lowered from the current level (CL) to a lower intermediate level (ML). And, the ACL control unit maintains the first line luminance at the middle level (ML) in the N+1th frame, and gradually increases the second line luminance from the middle level (ML) to the current level (CL). If the 2-frame average luminance for each line is controlled equally for all pixel lines, image quality issues when applying ACL will not be recognized due to the visual integration effect.

In addition, the ACL control unit maintains the entire screen luminance, including the first line luminance and the second line luminance, at an average level (AL) between the current level (CL) and the intermediate level (ML) in the N+2th frame. And, by changing the overall screen luminance from the average level (AL) to the target level (TL) through at least one N+3 frame, it is possible to reduce power consumption and provide circuit element effects through ACL, as well as, Screen flickering can be suppressed by reducing the luminance difference between the N+1th frame and the N+3th frame.

Meanwhile, in the luminance control method of the display device according to the third embodiment, the luminance of the current level (CL) is 100%, the luminance of the intermediate level (ML) is 80%, and the luminance of the average level (AL) is 90%. , and the luminance of the target level (TL) is illustrated as 70%. However, it should be noted that the technical idea of the present specification is not limited to the illustrated values and can cover all examples of various numerical modifications.

11 and 12 are diagrams showing a method of controlling luminance of a display device according to a fourth embodiment of the present specification. Compared to the second embodiment, the fourth embodiment allows the entire screen luminance to gradually converge from the average level (AL) to the target level (TL) during ACL application, thereby preventing flickering from being recognized due to luminance deviation between neighboring frames. There is an advantage to preventing it.

Referring to FIGS. 11 and 12, when the cumulative result (CNT) of the line current value in a specific pixel line (Lx) of the Nth frame exceeds a preset threshold, the ACL control unit applies ACL to this specific pixel line (Lx). The start line is determined, and the timing at which a specific pixel line (Lx) will be driven in the Nth frame is determined as the ACL start timing (Tx).

In order to reduce ACL image quality issues, the ACL control unit adjusts the luminance on a per-pixel line basis so that the 2-frame average luminance for each line is the same in all pixel lines in the Nth frame where ACL starts and the N+1 frame that is the subsequent frame. Control.

Specifically, the ACL control unit maintains the luminance of the first line from the Nth frame to the pixel line immediately preceding the ACL start pixel line (Lx) at the current level (CL), and maintains the luminance of the first line from the ACL start pixel line (Lx) to the current level (CL). The luminances are maintained by lowering them to an intermediate level (ML) lower than the current level (CL). In addition, the ACL control unit maintains the first line luminance at the middle level (ML) in the N+1th frame, and maintains the second line luminance by increasing it from the middle level (ML) to the current level (CL). If the 2-frame average luminance for each line is controlled equally for all pixel lines, image quality issues when applying ACL will not be recognized due to the visual integration effect.

In addition, the ACL control unit maintains the entire screen luminance, including the first line luminance and the second line luminance, at an average level (AL) between the current level (CL) and the intermediate level (ML) in the N+2th frame. And, by changing the overall screen luminance from the average level (AL) to the target level (TL) through at least one N+3 frame, it is possible to reduce power consumption and provide circuit element effects through ACL, as well as, Screen flickering can be suppressed by reducing the luminance difference between the N+1th frame and the N+3th frame.

Meanwhile, in the luminance control method of the display device according to the fourth embodiment, the luminance of the current level (CL) is 100%, the luminance of the intermediate level (ML) is 80%, and the luminance of the average level (AL) is 90%. , and the luminance of the target level (TL) is illustrated as 70%. However, it should be noted that the technical idea of the present specification is not limited to the illustrated values and can cover all examples of various numerical modifications.

13, 15, and 17 are diagrams showing the operation of a panel driver for implementing the luminance control method of a display device according to the third embodiment of the present specification. And, Figures 14, 16, and 18 are diagrams showing the operation of a panel driver for implementing the luminance control method of a display device according to the fourth embodiment of the present specification.

The operation of the panel driver illustrated in FIGS. 13, 15, and 17 can be similarly applied when implementing the luminance control method of the display device according to the first embodiment of the present specification. And, the operation of the panel driver illustrated in FIGS. 14, 16, and 18 can be similarly applied when implementing the luminance control method of the display device according to the second embodiment of the present specification. The specific values shown in FIGS. 13 to 18 are only examples, and the technical idea of the present specification is not limited to the values shown.

Referring to Figures 13 and 14, the panel driver supplies a scan signal (SCAN) to the screen in accordance with the writing timing of image data, and the pulse width or pulse position of the scan signal (SCAN) determines the luminance on a pixel line basis. It can be adjusted on a per-pixel line basis according to the ACL control signal (ACL-CON) for control. Through this adjustment, the luminance of the current level (CL) is set to 100% (corresponding to the first pulse width or first pulse position), and the luminance of the intermediate level (ML) is set to 80% (corresponding to the second pulse width or second pulse position). ), the luminance of the average level (AL) is 90% (corresponding to the third pulse width or the third pulse position), and the luminance of the target level (TL) is 70% (corresponding to the fourth pulse width or the fourth pulse position). (corresponding to location) can be controlled.

Referring to Figures 15 and 16, the panel driver supplies a data voltage (Vdata) corresponding to image data to the screen, and the size of the data voltage (Vdata) is an ACL control signal for controlling luminance on a pixel line basis. It can be adjusted per pixel line according to (ACL-CON). Through this adjustment, the luminance of the current level (CL) is set to 100% (corresponding to 10V), the luminance of the middle level (ML) is set to 80% (corresponding to 8V), and the luminance of the average level (AL) is set to 90% (corresponding to 8V). (corresponding to 9V), and the luminance of the target level (TL) can be controlled to 70% (corresponding to 7V).

Referring to Figures 17 and 18, the panel driver supplies a reference voltage (Vref) required for pixel driving to the screen, and the size of the reference voltage (Vref) is an ACL control signal (ACL control signal) for controlling luminance on a pixel line basis. ACL-CON) can be adjusted on a per-pixel line basis. Through this adjustment, the luminance of the current level (CL) is set to 100% (corresponding to 2V), the luminance of the middle level (ML) is set to 80% (corresponding to 3V), and the luminance of the average level (AL) is set to 90% (corresponding to 2V). (corresponding to 2.5V), and the luminance of the target level (TL) can be controlled to 70% (corresponding to 3.5V).

Through the above-described content, those skilled in the art will be able to see that various changes and modifications can be made without departing from the technical idea of the present invention. Therefore, the technical scope of the present invention should not be limited to what is described in the detailed description of the specification, but should be defined by the scope of the patent claims.

10: Controller 11: Data analysis unit
12: ACL control unit 20: Panel driver
30: display panel

Claims (13)

A display panel 30 having a screen composed of a plurality of pixel lines, and each pixel line including a plurality of pixels;
a panel driver 20 that drives the screen;
a data analysis unit (11) that analyzes the image data (DATA) to be written on the screen in units of pixel lines and accumulates line current values; and
An ACL start pixel line (Lx) for luminance control and a corresponding ACL start timing (Tx) are determined based on the cumulative result (CNT) of the line current value, and the first frame including the ACL start timing and the second subsequent frame are determined. A luminance control device for a display device including an ACL control unit (12) that controls luminance on a per-pixel line basis in a frame and controls the operation of the panel driver so that the average luminance of 2 frames per line is the same for all pixel lines. According to claim 1,
The ACL control unit,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). Gradually lower from the current level (CL) to a lower target level (TL),
In the second frame, maintaining the first line luminances at the target level and gradually increasing the second line luminances from the target level to the current level,
A luminance control device for a display device that maintains the entire screen luminance, including the first line luminance and the second line luminance, at the target level in a third frame following the second frame. According to claim 1,
The ACL control unit,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). Maintain the target level (TL) lower than the current level (CL),
In the second frame, maintain the first line luminances at the target level and maintain the second line luminances at the current level,
A luminance control device for a display device that maintains the entire screen luminance, including the first line luminance and the second line luminance, at the target level in a third frame following the second frame. According to claim 1,
The ACL control unit,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). Gradually lower from the current level (CL) to a lower intermediate level (ML),
In the second frame, maintaining the first line luminances at the intermediate level and gradually increasing the second line luminances from the intermediate level to the current level,
Maintaining the entire screen luminance, including the first line luminance and the second line luminance, at an average level between the current level and the intermediate level in a third frame following the second frame,
A luminance control device of a display device that changes the overall luminance of the screen from the average level to a target level (TL) through at least one fourth frame following the 3 frames. According to claim 1,
The ACL control unit,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). Maintain it at an intermediate level (ML) lower than the current level (CL),
In the second frame, maintaining the first line luminances at the intermediate level and maintaining the second line luminances at the current level,
Maintaining the entire screen luminance, including the first line luminance and the second line luminance, at an average level between the current level and the intermediate level in a third frame following the second frame,
A luminance control device of a display device that changes the overall luminance of the screen from the average level to a target level (TL) through at least one fourth frame following the 3 frames. According to claim 1,
The panel driver supplies a scan signal to the screen in accordance with the writing timing of the image data,
The pulse width or pulse position of the scan signal is adjusted on a per-pixel line basis according to an ACL control signal (ACL-CON) for controlling luminance on a per-pixel line basis. According to claim 1,
The panel driver supplies a data voltage corresponding to the image data to the screen,
The size of the data voltage is adjusted on a per-pixel line basis according to an ACL control signal (ACL-CON) for controlling the luminance on a per-pixel line basis. According to claim 1,
The panel driver supplies the screen with a reference voltage required to drive pixels,
The magnitude of the reference voltage is adjusted on a per-pixel line basis according to an ACL control signal (ACL-CON) for controlling the luminance on a per-pixel line basis. A method of controlling luminance of a display device having a screen composed of a plurality of pixel lines, a display panel including a plurality of pixels in each pixel line, and a panel driver that drives the screen, comprising:
A data analysis step of analyzing image data (DATA) to be written on the screen in units of pixel lines and accumulating line current values; and
An ACL start pixel line (Lx) for luminance control and a corresponding ACL start timing (Tx) are determined based on the cumulative result (CNT) of the line current value, and the first frame including the ACL start timing and the second subsequent frame are determined. A luminance control method for a display device including an ACL control step of controlling luminance on a per-pixel line basis in a frame, and controlling the operation of the panel driver so that the 2-frame average luminance for each line is the same for all pixel lines. According to clause 9,
The ACL control step is,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). Gradually lowering from the current level (CL) to a lower target level (TL);
In the second frame, maintaining the first line luminances at the target level and gradually increasing the second line luminances from the target level to the current level; and
A luminance control method of a display device including maintaining the first line luminance and the second line luminance at the target level in a third frame following the second frame. According to clause 9,
The ACL control step is,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). maintaining the target level (TL) lower than the current level (CL);
in the second frame, maintaining the first line luminances at the target level and maintaining the second line luminances at the current level; and
A luminance control method of a display device including maintaining the first line luminance and the second line luminance at the target level in a third frame following the second frame. According to clause 9,
The ACL control step is,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). Gradually lowering from the current level (CL) to a lower intermediate level (ML);
In the second frame, maintaining the first line luminances at the intermediate level and gradually increasing the second line luminances from the intermediate level to the current level;
maintaining the first line luminances and the second line luminances at an average level between the current level and the intermediate level in a third frame following the second frame; and
A luminance control method of a display device including changing the first line luminance and the second line luminance from the average level to a target level (TL) through at least one fourth frame following the 3 frames. According to clause 9,
The ACL control step is,
In the first frame, the first line luminances up to the pixel line immediately preceding the ACL start pixel line (Lx) are maintained at the current level (CL), and the second line luminances from the ACL start pixel line (Lx) are maintained at the current level (CL). maintaining an intermediate level (ML) lower than the current level (CL);
in the second frame, maintaining the first line luminances at the intermediate level and maintaining the second line luminances at the current level;
maintaining the first line luminances and the second line luminances at an average level between the current level and the intermediate level in a third frame following the second frame; and
A luminance control method of a display device including changing the first line luminance and the second line luminance from the average level to a target level (TL) through at least one fourth frame following the 3 frames.