KR102468139B1 - Video wall device - Google Patents

Abstract

According to an embodiment of the present invention, in a video wall device including a plurality of display panels, a video signal generator for generating a plurality of divided video signals corresponding to the plurality of display panels based on an external video signal, the plurality of displays A plurality of panel driving units corresponding to a panel and calculating an average picture level (APL) corresponding to the divided image signal of each display panel, based on the average value of the plurality of APLs by the plurality of panel driving units A power supply control unit that calculates a common peak luminance and calculates a plurality of power supply values corresponding to the plurality of display panels based on the plurality of APLs and the common peak luminance; A plurality of power supplies supplying first power of a first voltage to display panels, and supplying second power of a second voltage higher than the first voltage to the plurality of display panels based on the plurality of power supply values A video wall device including a power sharing unit is provided.

Description

Video wall device and its driving method {VIDEO WALL DEVICE}

The present invention relates to a video wall device including a plurality of display modules each display area of which is arranged in a matrix, and a method for driving the same.

Display devices are applied to various electronic devices such as TVs, mobile phones, laptops, and tablets. Accordingly, research is being conducted to develop thinning, lightening, and low power consumption of display devices.

Representative examples of the display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electro luminescence display device. Display device: ELD), Electro-Wetting Display device (EWD), Organic Light Emitting Display device (OLED), and the like.

The flat panel display device has a trend of widening its application range through thinning, light weight, and large size.

In particular, the flat panel display device may be implemented as a large display device having a size of 100 inches or more, such as a window, a billboard, or a game information board.

However, it is virtually impossible to prepare a 100-inch or larger flat panel display panel due to process difficulties and increased manufacturing costs.

Accordingly, a video wall device having a structure in which a plurality of display modules each including a display panel and a panel driver driving the display panel has been proposed.

Meanwhile, in the case of a display device implemented with a self-light emitting element, such as an organic light emitting display device, power consumption increases according to the brightness of light and the area of an effective area for emitting light in the display area. That is, the wider the area of the effective region and the higher the brightness of light, the higher the power consumption. Accordingly, when light of high brightness is emitted in a wide effective area, power supplied to a display panel displaying an image may be insufficient, and thus image display of the display panel may become unstable.

To prevent this, in the case of a display device implemented as a self-light emitting element, an image may be displayed using a peak luminance corresponding to an average picture level (APL). Here, APL corresponds to the area of the effective region, and peak luminance represents luminance corresponding to the highest gray level.

However, in a video wall device including a plurality of display modules, the plurality of display modules display a plurality of divided image signals corresponding to one image signal. Therefore, the plurality of display modules display each of the divided video signals using the peak luminance corresponding to the APL according to the different divided video signals. Accordingly, a plurality of divided image signals corresponding to one image are displayed with different brightness by a plurality of display modules, resulting in a luminance deviation between the plurality of display modules.

In order to improve this, the existing video wall device detects the maximum value expected to generate the lowest power consumption among the APLs corresponding to the plurality of divided image signals displayed on the plurality of display modules, and the plurality of display modules detects the maximum value. Each divided video signal is displayed using the peak luminance corresponding to the value of APL. Accordingly, it is possible to prevent display defects from occurring due to power shortage in at least some of the plurality of display modules. However, since the plurality of display modules display each divided image signal using the peak luminance corresponding to the maximum APL, there is a limitation in improving the overall luminance of the video wall device.

An object of the present invention is to provide a video wall device and a driving method thereof capable of preventing display defects due to power shortage in at least some of a plurality of display modules and improving overall luminance.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned above can be understood by the following description and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by means of the instrumentalities and combinations indicated in the claims.

An example of the present invention is a video wall device including a plurality of display panels, comprising: a video signal generator for generating the plurality of divided image signals corresponding to the plurality of display panels based on an external video signal; and the plurality of display panels. A plurality of panel driving units corresponding to and calculating APL (Average Picture Level, screen average brightness) corresponding to the divided video signals of each display panel, common based on the average value of the plurality of APLs by the plurality of panel driving units A power supply control unit that calculates peak luminance and calculates a plurality of power supply values corresponding to the plurality of display panels based on the plurality of APLs and the common peak luminance, corresponding to the plurality of display panels, and for each display A plurality of power supplies supplying first power of a first voltage to panels, and a power supply of second power of a second voltage higher than the first voltage to the plurality of display panels based on the plurality of power supply values A video wall device including a sharing unit is provided.

The plurality of power supply units supply second power of the second voltage to the power sharing unit, and a current of the second power supplied by each power supply unit corresponds to a predetermined power reference value and the second voltage, A current of the second power supplied by the power sharing unit to each of the display panels corresponds to a power supply value corresponding to each of the display panels and the second voltage.

The plurality of display panels display respective divided image signals based on the first power supply by the respective power supply units and the second power supply by the power sharing unit.

When the power supply controller detects a power supply value greater than a predetermined threshold value among the plurality of power supply values, the power supply control unit reduces the common peak luminance based on a difference between the detected power supply value and the threshold value, and The plurality of power supply values are corrected based on the APL of , and the reduced common peak luminance.

The power supply controller calculates an individual peak luminance corresponding to each APL based on a predetermined APL-peak luminance characteristic curve, and calculates the common peak luminance based on an average value of a plurality of individual peak luminances corresponding to the plurality of APLs. Luminance can be calculated.

Alternatively, the power supply control unit calculates an average value of the plurality of APLs, calculates a peak luminance corresponding to the average value of the APLs based on a predetermined APL-peak luminance characteristic curve, and converts the calculated peak luminance to the common peak It can be selected by luminance.

Another example of the present invention is a method for driving a video wall device including a plurality of display panels, wherein a plurality of image signal generators receiving image signals from the outside correspond to the plurality of display panels based on external image signals. Generating split image signals of the plurality of display panels, calculating an average picture level (APL) corresponding to the split image signals of each display panel by a plurality of panel driving units corresponding to the plurality of display panels, A power supply controller controlling power supply to the display panel calculates a common peak luminance based on an average value of a plurality of APLs corresponding to the plurality of divided video signals, and calculates the common peak luminance based on the plurality of APLs and common peak luminance. A method of driving a video wall device comprising calculating a plurality of power supply values corresponding to a plurality of display panels, and displaying divided image signals based on the respective power supply values by the plurality of display modules. provides

In the step of displaying each of the divided image signals by the plurality of display modules, a plurality of power supplies corresponding to the plurality of display panels supply first power of a first voltage to each display panel, and the first voltage supplying a second power of a higher second voltage to a power sharing unit corresponding to the plurality of display panels, wherein the power sharing unit supplies the second voltage to the plurality of display panels based on the plurality of power supply values; supplying a second power, and displaying, by the plurality of display modules, divided video signals based on the first power supplied by the plurality of power supply units and the second power supplied by the power sharing unit. . Here, the current of the second power supplied by each power supply unit corresponds to a predetermined power reference value and the second voltage, and the current of the second power supplied to each display panel by the power sharing unit corresponds to each display panel. Corresponds to a corresponding power supply value and the second voltage.

After the step of calculating the plurality of power supply values, when the power supply control unit derives a power supply value greater than a predetermined threshold value among the plurality of power supply values, the difference between the detected power supply value and the threshold value and correcting the plurality of power supply values based on the plurality of APLs and the reduced common peak luminance.

A video wall device according to each embodiment of the present invention includes a power supply controller for calculating a common peak luminance based on an average value of a plurality of APLs corresponding to a plurality of divided video signals to be displayed by a plurality of display panels, and a common peak and a power sharing unit supplying second power to the display panel based on luminance.

In this way, as a plurality of display panels display each divided video signal using the common peak luminance calculated based on the average value of the plurality of APLs, the overall luminance of the video wall device is improved compared to that of a general video wall device. can

In addition, the output of each power supply unit may be shared by a power sharing unit connected to a plurality of power supply units corresponding to a plurality of display panels, and as a result, higher power than the output of the power supply unit may be supplied to some display panels. Therefore, power shortage and resulting display defects can be prevented.

Accordingly, picture quality and reliability of the video wall device may be improved.

1 is a diagram illustrating a video wall device according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of an arrangement form of a plurality of display panels shown in FIG. 1 .
FIG. 3 is a diagram showing one of a plurality of display modules of FIG. 1 .
FIG. 4 is a diagram showing an example of an equivalent circuit corresponding to the pixel area of FIG. 4 .
5 is a diagram showing the power sharing unit of FIG. 1 .
6 is a diagram showing an example of an APL-peak luminance characteristic curve.
7 is a diagram illustrating an example of an APL corresponding to a plurality of divided video signals displayed on a plurality of display panels.
FIG. 8 is a diagram showing individual peak luminance according to the example of FIG. 7 .
9 is a diagram illustrating common peak luminance corresponding to the examples of FIGS. 7 and 8 in a general video wall device.
FIG. 10 is a diagram illustrating an example in which a plurality of divided video signals are displayed on a plurality of display panels based on the common peak luminance of FIG. 9 in a general video wall device.
FIG. 11 is a view showing common peak luminance corresponding to the examples of FIGS. 7 and 8 in the video wall device according to the first embodiment of the present invention.
FIG. 12 is a diagram illustrating an example in which a plurality of divided video signals are displayed on a plurality of display panels based on the common peak luminance of FIG. 11 in the video wall device according to the first embodiment of the present invention.
FIG. 13 is a diagram showing common peak luminance corresponding to the examples of FIGS. 7 and 8 in the video wall device according to the second embodiment of the present invention.
14 is a diagram illustrating a video wall device according to a third embodiment of the present invention.
15 is a view showing the current blocking unit of FIG. 14;

The above objects, features and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention belongs will be able to easily implement the technical spirit of the present invention. In describing the present invention, if it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

Hereinafter, a video wall device and a driving method thereof according to each embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, with reference to FIGS. 1 to 12 , a video wall device and a driving method thereof according to a first embodiment of the present invention will be described.

1 is a diagram illustrating a video wall device according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an example of an arrangement form of a plurality of display panels shown in FIG. 1 .

FIG. 3 is a diagram showing one of a plurality of display modules of FIG. 1 . FIG. 4 is a diagram showing an example of an equivalent circuit corresponding to the pixel area of FIG. 4 .

5 is a diagram showing the power sharing unit of FIG. 1 .

6 is a diagram showing an example of an APL-peak luminance characteristic curve.

7 is a diagram illustrating an example of an APL corresponding to a plurality of divided video signals displayed on a plurality of display panels. FIG. 8 is a diagram showing individual peak luminance according to the example of FIG. 7 .

9 is a diagram illustrating common peak luminance corresponding to the examples of FIGS. 7 and 8 in a general video wall device. FIG. 10 is a diagram illustrating an example in which a plurality of divided video signals are displayed on a plurality of display panels based on the common peak luminance of FIG. 9 in a general video wall device.

FIG. 11 is a view showing common peak luminance corresponding to the examples of FIGS. 7 and 8 in the video wall device according to the first embodiment of the present invention. FIG. 12 is a diagram illustrating an example in which a plurality of divided video signals are displayed on a plurality of display panels based on the common peak luminance of FIG. 11 in the video wall device according to the first embodiment of the present invention.

As shown in FIG. 1, the video wall device 100 according to the first embodiment of the present invention includes a plurality of display modules 101, 102, 103, and 104, and a plurality of display modules 101, 102, 103, and 104. ), and a power sharing unit 120 for sharing power of the plurality of display modules 101, 102, 103, 104.

Each display module (101, 102, 103, 104) is a display panel (10, 20, 30, 40) that substantially displays an image, a panel driver (11, 11, 21, 31, 41), and power supply units 12, 22, 32, 42 supplying power to the display panels 10, 20, 30, 40.

That is, as the video wall device 100 includes a plurality of display modules 101, 102, 103, and 104, a plurality of display panels 10, 20, 30, and 40 and a plurality of panel driving units corresponding thereto ( 11, 21, 31, 41) and power supply units 12, 22, 32, 42.

The display panels 10, 20, 30, and 40 include a plurality of pixel areas corresponding to display areas in which images are displayed, and display images by individually driving the plurality of pixel areas.

The panel driving units 11, 21, 31, and 41 supply driving signals to the display panels 10, 20, 30, and 40. And, the panel driver 11, 21, 31, 41 calculates the APL corresponding to the image signal to be displayed on the display panel 10, 20, 30, 40.

The power supply units 12, 22, 32, and 42 supply various types of power for driving the panel driving units 11, 21, 31, and 41 and the display panels 10, 20, 30, and 40.

The display modules 101, 102, 103, and 104 will be described in more detail below with reference to FIGS. 4 and 5.

The main driver 110 includes an image signal generator 111 that receives an external image signal and generates a plurality of divided image signals corresponding to the plurality of display panels 10, 20, 30, and 40 based on the external image signal. The plurality of display panels 10, 20, 30, and 40 include a power supply controller 112 that calculates a plurality of power supply values corresponding to power for displaying a plurality of divided image signals.

The image signal generator 111 may generate a plurality of divided image signals by dividing the external image signal according to the arrangement of the respective display regions of the plurality of display panels 10 , 20 , 30 , and 40 .

As mentioned above, the panel driver 11, 21, 31, 41 of each display module 101, 102, 103, 104 corresponds to the divided image signal of each display panel 10, 20, 30, 40. APL (Average Picture Level) is calculated.

The power supply control unit 112 receives APL corresponding to each divided video signal from each of the plurality of panel driving units 11, 21, 31, and 41 provided in the plurality of display modules 101, 102, 103, and 104. In other words, the power supply control unit 112 receives a plurality of APLs from the plurality of panel driving units 11, 21, 31, and 41, that is, a plurality of APLs corresponding to a plurality of divided video signals.

The power supply controller 112 calculates a common peak luminance based on an average value of a plurality of APLs. Further, the power supply control unit 112 calculates a plurality of power supply values corresponding to the plurality of display panels 10, 20, 30, and 40 based on the plurality of APLs and the common peak luminance.

The common peak luminance and the plurality of power supply values will be described in detail with reference to FIGS. 6 to 11 below.

As mentioned above, the plurality of power supply units 12, 22, 32, and 42 provided in the plurality of display modules 101, 102, 103, and 104 supply various types of power. Illustratively, the power supply units 12, 22, 32, and 42 may supply a first power source V1 having a first voltage and a second power source V2 having a second voltage higher than the first voltage. Here, the first voltage may be for driving the thin film transistor, and the second voltage may be for driving the organic light emitting device.

The plurality of power supply units 12, 22, 32, and 42 supply first power V1 to each display panel 10, 20, 30, and 40, and supply second power to the power sharing unit 120. (V2) is supplied. Here, the current of the second power supply (V2) supplied to the power sharing unit 120 by each of the power supply units 12, 22, 32, and 42 corresponds to a predetermined power reference value and the second voltage. That is, the current of the second power supply (V2) supplied to the power sharing unit 120 by each of the power supply units 12, 22, 32, and 42 may be a value obtained by dividing the power reference value by the second voltage.

The power sharing unit 120 supplies second power V2' to the plurality of display panels 10, 20, 30, and 40 based on a plurality of power supply values by the power supply control unit 112. Here, the current of the second power source V2′ supplied by the power sharing unit 120 to each display panel 10, 20, 30, and 40 is the power corresponding to each display panel 10, 20, 30, and 40. Corresponds to the supply value and the second voltage. That is, the current of the second power source V2′ supplied by the power sharing unit 120 to each display panel 10, 20, 30, and 40 is the power corresponding to each display panel 10, 20, 30, and 40. It may be a value obtained by dividing the supply value by the second voltage. Accordingly, as the power supply value corresponding to each display panel 10, 20, 30, and 40 increases, the second power V2 supplied by the power sharing unit 120 to each display panel 10, 20, 30, and 40 ') increases.

As a result, the plurality of display panels 10, 20, 30, and 40 are provided with driving signals supplied from respective panel driving units 11, 21, 31, and 41 and supplied from respective power supply units 12, 22, 32, and 42. Each divided image signal is displayed based on the first power source V1 and the second power source V2' supplied from the power sharing unit 120.

As shown in FIG. 2, the display areas AA1, AA2, AA3, and AA4 of the plurality of display panels 10, 20, 30, and 40 are arranged in a matrix.

Although FIG. 2 shows four display panels 10, 20, 30, and 40 arranged in a 2x2 matrix, this is only an example, and the video wall device 100 according to each embodiment of the present invention has respective display areas. (AA1, AA2, AA3, AA4) may include two or more display panels 10, 20, 30, and 40 arranged in an n x m matrix. (where n and m are each a natural number greater than or equal to 1)

As shown in FIG. 3 , one of the plurality of display modules 101 , 102 , 103 , and 104 101 includes a display panel 10 and a panel driver 11 .

The display panel 10 includes a display area AA where an image is displayed and a non-display area outside the display area AA.

The display panel 10 includes a plurality of pixel areas PXL defined in the display area AA.

Further, the display panel 10 includes a scan line SL corresponding to each horizontal line composed of pixel areas arranged in parallel in a horizontal direction among a plurality of pixel areas PXL, and a vertical scan line SL among the plurality of pixel areas PXL. A data line DL corresponding to each vertical line made up of pixel areas arranged in parallel in a direction is further included. In this case, the plurality of pixel areas PXL may be defined by the intersection of the scan line 15 and the data line 14 .

In addition, the display panel 10 includes a first driving power line supplying the first driving power supply VDD and a second driving power supply supplying the second driving power supply VSS having a lower potential than the first driving power supply VDD. A line and a reference power line supplying the reference power VREF may be further included.

Illustratively, the first driving power source VDD may correspond to the second power source (V2′ in FIG. 1 ) by the power sharing unit ( 120 in FIG. 1 ).

The panel driver 11 includes a data driver 201 that drives the data line DL of the display panel 10, a gate driver 202 that drives the scan line SL of the display panel 10, and a data driver. 201 and a timing controller 203 for controlling driving timing of each of the gate driver 202.

The timing controller 203 rearranges the digital video data RGB input from the outside according to the resolution of the display panel 10 and supplies the rearranged digital video data RGB′ to the data driver 201 .

Also, the timing controller 203 operates the data driver 201 based on timing signals such as the vertical sync signal (Vsync), the horizontal sync signal (Hsync), the dot clock signal (DCLK), and the data enable signal (DE). A data control signal DDC for controlling the operation timing and a gate control signal GDC for controlling the operation timing of the gate driver 202 are supplied.

The data driver 201 converts the rearranged digital video data RGB' into an analog data voltage based on the data control signal DDC. Also, the data driver 201 supplies the data signal VDATA to the pixel area through the data line DL for each horizontal period based on the rearranged digital video data RGB'.

Illustratively, the data signal VDATA may correspond to the first power supply (V1 in FIG. 1) by the power supply unit (12 in FIG. 1).

The gate driver 202 supplies a scan signal SCAN and a sense signal SENSE corresponding to each horizontal line based on the gate control signal GDC.

The scan signal SCAN is for selecting a horizontal line to supply the data signal VDATA during the addressing period.

The sense signal SENSE is for selecting a horizontal line to supply the reference power VREF during the initial period.

As shown in FIG. 4 , each of the pixel regions PXL1 and PXL2 includes an organic light emitting diode (OLED), first, second and third thin film transistors T1, T2 and T3, and a storage capacitor Cst. .

The organic light emitting diode (OLED) includes an anode electrode, a cathode electrode, and an organic light emitting layer (not shown) disposed between them. Illustratively, the organic light emitting layer includes a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer. Alternatively, the organic light emitting layer may further include an electron injection layer.

The first thin film transistor T1 has a first driving power line VDDL supplying the first driving power supply VDD and a second driving power supply VSS having a lower potential than the first driving power supply VDD. It is disposed in series with the organic light emitting diode (OLED) between the driving power lines.

The second thin film transistor T2 is disposed between the data line DL and the first thin film transistor T1. When the second thin film transistor T2 is turned on based on the scan signal SCAN of the scan line SL1, the first node (between the gate electrode of the first thin film transistor T1 and the second thin film transistor T2) ND1) is supplied with a data signal (VDATA).

The storage capacitor Cst is disposed between the first node ND1 and the second node ND2. The second node ND2 is a contact point between the first thin film transistor T1 and the organic light emitting diode OLED.

The storage capacitor Cst is charged based on the data signal VDATA supplied to the first node ND1 through the turned-on second thin film transistor T2.

When the first thin film transistor T1 is turned on based on the charging voltage of the storage capacitor Cst, a driving current corresponding to the data voltage VDATA is supplied to the organic light emitting diode OLED.

The third thin film transistor T3 is disposed between the reference power supply line VREFL supplying the reference power VREF and the second node ND2. When the third thin film transistor T3 is turned on based on the sense signal SENSE of the sense line SL2 corresponding to each horizontal line, it supplies the reference power VREF to the second node ND2, or 2 Transmits the potential of node ND2 to the reference power line VREFL.

As mentioned above, the video wall device 100 according to the first embodiment of the present invention includes a power sharing unit 120 connected to a plurality of power supply units 12, 22, 32, and 42.

As shown in FIG. 5, the power sharing unit 120 connects the outputs of the plurality of power supply units 12, 22, 32, and 42 provided in the plurality of display modules 101, 102, 103, and 104. It may include two or more power sharing switches 121 and a sharing switch driver 122 that drives the two or more power sharing switches 121 .

Here, the sharing switch driver 122 may generate driving signals for the plurality of power sharing switches 121 based on a plurality of power supply values.

Exemplarily, when the first power supply value corresponding to the first display panel 10 is smaller than the second power supply value corresponding to the second display panel 20, the first power supply value corresponding to the first display panel 10 Through a power sharing switch between the first power supply unit 12 and the second power supply unit 22 corresponding to the second display panel 20, some of the output power of the first power supply unit 12 is transferred to the second power supply unit ( 22) can be supplied to the second display panel 20 together with the output power.

Similarly, when the third power supply value corresponding to the third display panel 30 is greater than the fourth power supply value corresponding to the fourth display panel 40, the third power supply corresponding to the third display panel 30 Through a power sharing switch between the supply unit 32 and the fourth power supply unit 42 corresponding to the fourth display panel 40, some of the output power of the fourth power supply unit 42 is transferred to the third power supply unit 32. It can be supplied to the third display panel 30 together with the output power of .

Also, the sharing switch driving unit 122 may generate a driving signal for the power sharing switch 121 based on the power on/off sequence of the video wall device 100 .

As described above, in the video wall device 100 according to the first embodiment of the present invention, outputs of the plurality of power supply units 12, 22, 32, and 42 corresponding to the plurality of display panels 10, 20, 30, and 40 By including the power sharing unit 120 for sharing, power higher than the output of each power supply unit 12, 22, 32, 42 is supplied to some of the plurality of display panels 10, 20, 30, 40. It can be. Accordingly, it is possible to prevent display defects from occurring due to power shortage in some of the plurality of display panels 10 , 20 , 30 , and 40 .

As mentioned above, the video wall apparatus 100 according to the first embodiment of the present invention calculates a common peak luminance based on an average value of a plurality of APLs corresponding to a plurality of divided video signals, and calculates a plurality of display panels 10 . , 20, 30, 40) and a power supply controller 112 that calculates a plurality of power supply values.

Meanwhile, in case of driving a single display module displaying a single image signal, APL and peak luminance may be in inverse proportion to each other in order to prevent power shortage during driving of the display panel. That is, since power consumption increases as one of the APL and peak luminance increases, it is common to set a lower peak luminance as the APL increases in order to prevent power consumption from exceeding a threshold value.

Illustratively, as shown in FIG. 6, when the APL is 25% or less, the peak luminance is set to the maximum value (400 nit), and when the APL is about 95% or more, the peak luminance is set to the minimum value (100 nit), and the APL is set to 25 In the range between % and 95%, the peak luminance may be set to a value inversely proportional to each APL at a predetermined rate.

As mentioned above, the panel driver (11, 21, 31, 41 in FIG. 1) of each display module (101, 102, 103, 104) divides the video signal of each display panel (10, 20, 30, 40). Calculate APL (Average Picture Level) corresponding to

For example, as shown in FIG. 7 , the first, second, third and fourth panel driving units corresponding to the first, second, third and fourth display panels 10, 20, 30 and 40 ( 11, 21, 31, 41) are the division image signals to be displayed in the display areas AA1, AA2, AA3, and AA4 of the first, second, third, and fourth display panels 10, 20, 30, and 40. A corresponding APL is calculated.

That is, the first, second, third and fourth APLs (APL1, APL2, APL3, APL4) is calculated. As indicated by light and shade in Fig. 7, in the following description, it is assumed that APL1, APL3, APL2 and APL4 are large values in the order. (APL1 < APL3 < APL2 < APL4)

If the first, second, third, and fourth display panels 10, 20, 30, and 40 are individually driven, each single image is displayed using a peak luminance according to an APL corresponding to each single image. display

That is, as shown in FIG. 8, the first display panel 10 displays an image using the first peak luminance corresponding to the first APL (APL1), and the second display panel 20 displays the second APL. The image is displayed using the second peak luminance corresponding to (APL2), and the third display panel 30 displays the image using the third peak luminance corresponding to the third APL (APL3). The panel 40 displays an image using the fourth peak luminance corresponding to the fourth APL (APL4).

However, the video wall device displays a single image using a plurality of display panels 10, 20, 30, and 40. To this end, a plurality of divided image signals corresponding to a single image are generated according to the arrangement of the plurality of display panels 10, 20, 30 and 40, and the plurality of display panels display the plurality of divided image signals.

At this time, it is necessary to prevent a single image corresponding to the video wall device from being displayed with different brightness for each region corresponding to the plurality of display panels 10, 20, 30, and 40. That is, it is necessary to prevent a luminance deviation between a plurality of display panels.

That is, as shown in FIG. 9, the first, second, third and fourth display panels 10, 20, 30 and 40 correspond to the divided image signals of the first, second, third and fourth display panels. APLs (APL1, APL2, APL3, and APL4) may be derived as different values. Accordingly, individual peak luminances corresponding to the first, second, third, and fourth APLs (APL1, APL2, APL3, and APL4) are also derived as different values.

Accordingly, in the case of a general video wall device, the maximum value among the first, second, third, and fourth APLs (APL1, APL2, APL3, and APL4) is detected, and the peak luminance corresponding to the maximum APL (APL_max) ( Lumi_min) is selected as the common peak luminance, and the plurality of display panels 10, 20, 30, and 40 display each divided image signal using the common peak luminance.

At this time, in order to prevent a luminance deviation between the first, second, third, and fourth display panels 10, 20, 30, and 40, a general video wall device calculates a predetermined common peak luminance corresponding to a plurality of APLs. The first, second, third, and fourth display panels 10, 20, 30, and 40 display each divided image signal with the same brightness using a common peak luminance.

Since power consumption of each display panel 10 , 20 , 30 , and 40 is proportional to APL and peak luminance, it is necessary to prevent display defects due to insufficient power of some display panels 10 , 20 , 30 , and 40 .

Accordingly, a general video wall device has the maximum APL corresponding to the lowest individual peak luminance (Lumi_min) among the first, second, third, and fourth APLs (APL1, APL2, APL3, and APL4) (FIGS. 8 and 9). Common peak luminance is calculated through APL4, APL_max) of

And, as shown in FIG. 10, in a general video wall device, the first, second, third and fourth display panels 10, 20, 30 and 40 are the first, second, third and fourth display panels. Each divided video signal is displayed according to the common peak luminance corresponding to the maximum value of APL (APL_max) among 4 APLs (APL1, APL2, APL3, and APL4).

At this time, the maximum APL (APL_max) among the first, second, third, and fourth APLs (APL1, APL2, APL3, and APL4) corresponds to the lowest individual peak luminance (Lumi_min). Therefore, when the individual peak luminance (Lumi_min) corresponding to the maximum value of APL (APL_max) is selected as the common peak luminance, like a general video wall device, the display of the video wall device becomes generally dark.

To improve this, the video wall apparatus 100 according to the first embodiment of the present invention calculates a common peak luminance based on an average value (APL_avg) of a plurality of APLs (APL1, APL2, APL3, and APL4).

That is, the plurality of panel driving units 11, 21, 31, and 41 generate APLs (APL1, APL2, APL3, and APL4) of divided image signals corresponding to the respective display panels 10, 20, 30, and 40.

Exemplarily, as shown in FIG. 11, the APLs (APL1, APL2, APL3, APL4) can be calculated.

Also, the power supply control unit 112 calculates a common peak luminance corresponding to an average value (APL_avg) of a plurality of APLs (APL1, APL2, APL3, and APL4) by the plurality of panel driving units 11, 21, 31, and 41. do.

For example, the power supply controller 112 calculates individual peak luminance corresponding to each APL (APL1, APL2, APL3, APL4) based on a predetermined APL-peak luminance characteristic curve (eg, the curve of FIG. 6). Then, an average value of a plurality of individual peak luminances corresponding to a plurality of APLs (APL1, APL2, APL3, and APL4) may be calculated, and an individual peak luminance (Lumi_avg) of the average value may be selected as a common peak luminance.

As another example, the power supply controller 112 calculates an average APL (APL_avg) for a plurality of APLs (APL1, APL2, APL3, and APL4), and calculates a predetermined APL-peak luminance characteristic curve (eg, FIG. 6 ). A peak luminance (Lumi_avg) corresponding to the average APL (APL_avg) is calculated based on the curve of ), and the calculated peak luminance (Lumi_avg) can be selected as the common peak luminance.

And, as shown in FIG. 12, the plurality of display panels 10, 20, 30, 40 display each divided video signal based on the common peak luminance Lumi_avg corresponding to the average value of APL (APL_avg). .

In this way, since the peak luminance (Lumi_avg) corresponding to the average APL (APL_avg) is higher than the peak luminance (Lumi_min) corresponding to the maximum APL (APL_max), the overall luminance of the video wall device 100 is a general video It can be improved compared to wall devices.

However, as in the first embodiment of the present invention, when the common peak luminance is calculated based on the average value (APL_avg) of the plurality of APLs (APL1, APL2, APL3, and APL4), the plurality of display panels 10, 20, 30 and 40), power by the power supply unit 12 may be insufficient in some parts where the APL is higher than the average APL (APL_avg).

That is, as illustrated in FIG. 11 , among the plurality of display panels AA1 , AA2 , AA3 , and AA4 , some (AA2 and AA4) whose APL is higher than the average APL (APL_avg) supply power corresponding to the APL and common peak luminance. The value is higher than the supplyable power of the power supply unit 12. Some of the display panels AA2 and AA4 cannot display each divided video signal at a common peak luminance only with the power supplied from the power supply unit 12 .

Accordingly, the video wall apparatus 100 according to the first embodiment of the present invention includes a power sharing unit 120 that shares the outputs of the plurality of power supply units 12, 22, 32, and 42, so that some display panels can solve the power shortage.

As mentioned above, the power supply controller 112 calculates a plurality of power supply values corresponding to each of the plurality of APLs and the common peak luminance. For reference, in the bar graph on the right side of FIG. 11, the area of the bar figure corresponding to the plurality of display panels AA1, AA2, AA3, and AA4 corresponds to the plurality of display panels AA1, AA2, AA3, and AA4. Corresponds to the power supply value.

Further, the power sharing unit 120 connected to the plurality of power supply units 12, 22, 32, and 42 supplies second power to the plurality of display panels 10, 20, 30, and 40 based on the plurality of power supply values. (V2') is supplied.

Specifically, the plurality of power supply units 12 , 22 , 32 , and 42 supply second power V2 having a second voltage to the power sharing unit 120 based on a predetermined power reference value. At this time, the current of the second power supply (V2) by each power supply unit (12, 22, 32, 42) corresponds to the power reference value and the second voltage.

The power sharing unit 120 supplies the second power source V2' of the second voltage to the plurality of display panels 10, 20, 30, and 40 based on the plurality of power supply values. At this time, the current of the second power supply (V2') supplied from the power sharing unit 120 to each of the display panels 10, 20, 30, and 40 is the power corresponding to each display panel 10, 20, 30, and 40. Corresponds to the supply value and the second voltage. Here, the power supply value corresponding to each display panel 10 , 20 , 30 , and 40 corresponds to the APL and common peak luminance corresponding to each display panel 10 , 20 , 30 , and 40 . Since the common peak luminance is set to the same value for a plurality of display panels 10, 20, 30, and 40, the higher the APL corresponding to each display panel 10, 20, 30, and 40, the higher each display panel 10, The power supply value corresponding to 20, 30, 40) increases. Accordingly, the current of the second power source V2' supplied to each display panel 10, 20, 30, and 40 is proportional to the APL corresponding to each display panel 10, 20, 30, and 40.

Among the plurality of display panels AA1, AA2, AA3, and AA4, some of the display panels AA2 and AA4 whose APL is higher than the average APL (APL_avg) are supplied with second power by the respective power supply units 22 and 42. It is not possible to properly display a divided video signal of common peak luminance only with the power of (V2).

On the other hand, among the plurality of display panels AA1 , AA2 , AA3 , and AA4 , the rest of the other display panels AA1 and AA3 whose APL is lower than the average APL (APL_avg) are supplied to the corresponding power supply units 12 and 32 . Even with less power than the power of the second power source V2, it is possible to appropriately display divided video signals of common peak luminance. Accordingly, margin is generated in the outputs of the power supply units 12 and 32 corresponding to the remaining display panels AA1 and AA3 whose APL is lower than the average APL (APL_avg).

Accordingly, the power share unit 120 is a power supply unit corresponding to the remaining display panels AA1 and AA3 whose APL is lower than the average APL (APL_avg) among the plurality of display panels AA1, AA2, AA3, and AA4 ( 12 and 32) are supplied to some of the display panels AA1 and AA3 whose APL is higher than the average APL (APL_avg).

Accordingly, the video wall apparatus 100 according to the first embodiment of the present invention has the advantage of improving overall luminance and prevents power shortage in some of the plurality of display panels 10, 20, 30, and 40. There are advantages to avoiding this.

Meanwhile, according to the first embodiment of the present invention, the power sharing unit 120 transmits the second power source V2' of the second voltage to the plurality of display panels 10, 20, 30, 40) is supplied.

However, the current of the second power source V2 ′ according to the power supply value corresponding to the relatively large APL may be greater than or equal to a threshold acceptable for each display panel 10 , 20 , 30 , or 40 . At this time, there is a problem that malfunction or damage of the display panels 10, 20, 30, and 40 may be caused by the current of the second power source V2' having a threshold or higher level.

To improve this, the video wall apparatus according to the second embodiment of the present invention reduces the common peak luminance when a power supply value greater than a predetermined threshold value is detected among a plurality of power supply values.

FIG. 13 is a diagram showing common peak luminance corresponding to the examples of FIGS. 7 and 8 in the video wall device according to the second embodiment of the present invention.

As shown in FIG. 13, the power supply control unit (112 in FIG. 1) of the video wall device according to the second embodiment of the present invention provides an average value of APL (APL_avg) for a plurality of APLs (AP1, APL2, APL3, and APL4). ), a common peak luminance is derived, and a plurality of power supply values are calculated based on a plurality of APLs (AP1, APL2, APL3, APL4) and a common peak luminance (Lumi_avg). For reference, in the upper right bar graph of FIG. 13, the area of the bar figure corresponding to the plurality of display panels AA1, AA2, AA3, and AA4 corresponds to the plurality of display panels AA1, AA2, AA3, and AA4. Corresponds to the power supply value of

When the power supply control unit 112 detects a power supply value greater than a predetermined threshold value among a plurality of power supply values, the common peak luminance Lumi_avg is reduced based on the difference (P) between the detected power supply value and the threshold value. let it Here, the threshold value may be selected from a current value range causing malfunction or damage of the display panels AA1 , AA2 , AA3 , and AA4 and a power value range corresponding to the second voltage.

And, as shown in the lower right graph of FIG. 13, the power supply controller 112 corrects a plurality of power supply values based on the plurality of APLs (AP1, APL2, APL3, and APL4) and the reduced common peak luminance (Lumi_rev). .

In addition, the power supply control unit 112 transfers the corrected plurality of power supply values to the power share unit (120 in FIG. 1).

The power sharing unit 120 supplies the second power source V2' based on the corrected plurality of power supply values.

In this way, according to the second embodiment, the power supply control unit 112 reduces the common peak luminance Lumi_avg based on a predetermined threshold value for the power supply value, and based on the reduced common peak luminance Lumi_rev Except for correcting a plurality of power supply values, it is the same as the first embodiment, so redundant description is omitted.

As described above, according to the second embodiment of the present invention, when a power supply value exceeding the threshold value is detected, the common peak luminance Lumi_avg is reduced based on the excess amount P, so that the second power supply (which is above the threshold value) Malfunction or damage of the display panels 10, 20, 30, and 40 due to the current of V2' can be prevented. Accordingly, the reliability and lifespan of the video wall device 100 may be improved.

Meanwhile, according to the first and second embodiments of the present invention, the plurality of display panels 10, 20, 30, and 40 are each divided based on the common peak luminance Lumi_avg corresponding to the average APL (APL_avg). In order to secure the reliability of displaying the video signal, the plurality of power supply units 12, 22, 32, 42 need to supply the second power V2 equal to or higher than the power reference value. As a result, abnormal outputs of the power supply units 12, 22, 32, and 42 may occur.

Accordingly, the video wall device according to the third embodiment of the present invention further includes an abnormality detection unit for detecting an abnormal output of each power supply unit 12, 22, 32, 42.

14 is a diagram illustrating a video wall device according to a third embodiment of the present invention. 15 is a view showing the current blocking unit of FIG. 14;

As shown in FIG. 14, the video wall device 100' according to the third embodiment of the present invention has an abnormality detection unit disposed between each power supply unit 12, 22, 32, 42 and the power sharing unit 120. Except for further including (13, 23, 33, 43), it is the same as the first and second embodiments, so redundant description will be omitted below.

As shown in FIG. 15, one of the plurality of abnormality detection units 13, 23, 33, 43 corresponding to the plurality of power supply units 12, 22, 32, 42 has one end of the power supply unit 13. A cut-off switch 13sw connected to the output of the supply unit 12, a current detector 13cs connected to the other end of the cut-off switch 13sw, and a cut-off switch based on the current corresponding to the potential of both ends of the current detector 13cs ( 13sw) and a comparator 13co supplying a driving signal.

The comparator 13co supplies a cutoff drive signal to the cutoff switch 13sw when the current corresponding to the potential across the current detector 13cs is equal to or greater than a predetermined threshold current. Then, the cut-off switch 13sw blocks the output of the power supply unit 12 based on the cut-off drive signal.

As described above, the video wall device 100 according to the third embodiment includes the abnormality detection unit 13, so that abnormal current of the power supply units 12, 22, 32, and 42 can be blocked without separate driving control. Accordingly, malfunction or damage to the power sharing unit 120 and each of the display panels 10, 20, 30, and 40 can be prevented. As a result, reliability of the video wall device 100 may be further improved.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present invention. Conventionally in the art to which the present invention belongs It will be clear to those who have knowledge of

100, 100': video wall device
101, 102, 103, 104: display module
10, 20, 30, 40: display panel
11, 21, 31, 41: panel driving unit
12, 22, 32, 42: power supply unit
110: main driving unit
111: video signal generator
112: power supply control unit
120: power sharing unit
V1: 1st power supply
V2: 2nd power according to power reference value
V2': 2nd power according to each power supply value
AA1, AA2, AA3, AA4: display area
PXL: pixels
APL_max: APL of maximum value
Lumi_min: Peak luminance corresponding to the maximum value of APL
APL_avg: average value for multiple APLs
Lumi_avg: Peak luminance corresponding to the average value for a plurality of APLs
13, 23, 33, 43: abnormality detection unit

Claims (13)

In a video wall device including a plurality of display panels,
an image signal generator for generating a plurality of divided image signals corresponding to the plurality of display panels based on an external image signal;
a plurality of panel driving units corresponding to the plurality of display panels and calculating an average picture level (APL) corresponding to the divided image signal of each display panel;
A common peak luminance is calculated based on an average value of a plurality of APLs by the plurality of panel drivers, and a plurality of power supply values corresponding to the plurality of display panels are calculated based on the plurality of APLs and the common peak luminance. a power supply control unit;
a plurality of power supply units corresponding to the plurality of display panels and supplying first power of a first voltage to each of the display panels; and
a power sharing unit supplying second power having a second voltage higher than the first voltage to the plurality of display panels based on the plurality of power supply values;
The first power of the first voltage is a data signal, and the second power of the second voltage is a first driving power.
According to claim 1,
The plurality of power supply units supply second power of the second voltage to the power share unit,
The current of the second power supplied by each power supply unit corresponds to a predetermined power reference value and the second voltage,
The current of the second power supplied to each display panel by the power sharing unit corresponds to a power supply value corresponding to each display panel and the second voltage.
According to claim 2,
The plurality of display panels
A video wall device displaying each divided video signal based on the first power supply by each power supply unit and the second power supply by the power sharing unit.
According to claim 2,
The power supply control unit
When detecting a power supply value greater than a predetermined threshold value among the plurality of power supply values,
reduce the common peak luminance based on the difference between the detected power supply value and the threshold;
A video wall device for correcting the plurality of power supply values based on the plurality of APLs and the reduced common peak luminance.
According to claim 1,
The power supply control unit
Calculate individual peak luminance corresponding to each APL based on a predetermined APL-peak luminance characteristic curve;
The video wall device for calculating the common peak luminance based on an average value of a plurality of individual peak luminances corresponding to the plurality of APLs.
According to claim 1,
The power supply control unit
Calculate an average value for the plurality of APLs,
A video wall device that calculates a peak luminance corresponding to an average value of the APL based on a predetermined APL-peak luminance characteristic curve and selects the calculated peak luminance as the common peak luminance.
A method for driving a video wall device including a plurality of display panels,
generating a plurality of divided image signals corresponding to the plurality of display panels based on the external image signal by an image signal generating unit receiving an image signal from the outside;
calculating an average picture level (APL) corresponding to the divided image signal of each display panel by a plurality of panel drivers corresponding to the plurality of display panels;
A power supply controller controlling power supply to the plurality of display panels calculates a common peak luminance based on an average value of a plurality of APLs corresponding to the plurality of divided video signals, and determines the plurality of APLs and common peak luminance. calculating a plurality of power supply values corresponding to the plurality of display panels on the basis of;
supplying first power of a first voltage to each of the display panels by a plurality of power supply units corresponding to the plurality of display panels;
supplying, by a power sharing unit, second power having a second voltage higher than the first voltage to the plurality of display panels based on the plurality of power supply values; and
Displaying, by the plurality of display modules, respective divided image signals based on respective power supply values;
The first power of the first voltage is a data signal, and the second power of the second voltage is a first driving power.
According to claim 7,
The step of displaying each divided image signal by the plurality of display modules,
A plurality of power supply units corresponding to the plurality of display panels supplies first power of a first voltage to each display panel, and second power of a second voltage higher than the first voltage corresponds to the plurality of display panels. supplying power to one power sharing unit;
supplying second power of the second voltage to the plurality of display panels based on the plurality of power supply values by the power sharing unit; and
Displaying, by the plurality of display modules, divided video signals based on first power from the plurality of power supply units and second power from the power sharing unit;
The current of the second power supplied by each power supply unit corresponds to a predetermined power reference value and the second voltage,
The current of the second power supplied to each display panel by the power sharing unit corresponds to a power supply value corresponding to each display panel and the second voltage.
According to claim 7,
After calculating the plurality of power supply values,
When the power supply controller detects a power supply value greater than a predetermined threshold value among the plurality of power supply values, the common peak luminance is reduced based on a difference between the detected power supply value and the threshold value, and The method of driving a video wall device further comprising correcting the plurality of power supply values based on an APL of , and the reduced common peak luminance.
According to claim 7,
The step of calculating the plurality of power supply values
calculating an individual peak luminance corresponding to each APL based on a predetermined APL-peak luminance characteristic curve;
calculating the common peak luminance based on an average value of a plurality of individual peak luminances corresponding to the plurality of APLs; and
and calculating a plurality of power supply values based on the plurality of APLs and the common peak luminance.
According to claim 7,
The step of calculating the plurality of power supply values
Calculating an average value of the plurality of APLs;
calculating a peak luminance corresponding to an average value of the APL based on a predetermined APL-peak luminance characteristic curve and selecting the calculated peak luminance as the common peak luminance; and
and calculating a plurality of power supply values based on the plurality of APLs and the common peak luminance. According to claim 1,
The video wall device of claim 1 , wherein the power sharing unit includes two or more power sharing switches that connect outputs of the plurality of power supply units, and a sharing switch driving unit that drives the two or more power sharing switches.
According to claim 7,
The power sharing unit includes two or more power sharing switches that connect outputs of the plurality of power supply units, and a sharing switch driving unit that drives the two or more power sharing switches.

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