Display device

Abstract

To provide a display device capable of prolonging the lifetime of a display panel.SOLUTION: A display device comprises a display panel including a plurality of light-emitting areas and a control device which controls the plurality of light-emitting areas. The control device determines degrees of risk of burning of the plurality of light-emitting areas based on an input video signal received from the outside and controls luminance of the plurality of light-emitting areas in such a manner that a level of an inclination of reduction of luminance in a peripheral area adjacent to a reference area becomes larger with respect to luminance in the reference area in the plurality of light-emitting areas as the risk of burning becomes higher.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a display device. [Background technology]

[0002] In recent years, display devices having self-luminous elements such as OLEDs (Organic Light Emitting Diodes) arranged in a matrix have been developed. In such display devices, in the luminous areas including information such as characters, there are many boundaries between white and black in the image, in other words, there are many boundaries between areas with 100% brightness and areas with 0% brightness. Therefore, there is a risk that burn-in of the 100% brightness area will be prominent at the boundaries. In other words, the more information there is in the luminous area, the more likely it is that burn-in will be prominent.

[0003] Therefore, according to the technology disclosed in Patent Document 1, the amount of information such as characters in each light-emitting area is determined. Based on the amount of information, the brightness of the light-emitting area with a large amount of information is reduced, thereby suppressing burn-in in the light-emitting area with a large amount of information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-237690 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology disclosed in the above Patent Document 1 only reduces the brightness of a specific light-emitting area with a large amount of information and the light-emitting areas outside of it. Therefore, in some areas constituting a plurality of light-emitting areas, the light-emitting elements may be turned on with unnecessary brightness. In this case, the life of the light-emitting elements included in such some light-emitting areas may be shortened unnecessarily. As a result, the life of the display panel cannot be extended.

[0006] The present disclosure has been made in view of the above-mentioned problems. It is an object of the present disclosure to provide a display device that can extend the life of a display panel. [Means for solving the problem]

[0007] The display device of the present disclosure comprises a display panel including a plurality of light-emitting areas and a control device that controls the plurality of light-emitting areas, and the control device determines the degree of risk of burn-in of the plurality of light-emitting areas based on an input video signal received from outside, and controls the luminance of the plurality of light-emitting areas so that the higher the risk of burn-in, the greater the level of the slope of the decrease in luminance of a surrounding area adjacent to a reference area among the plurality of light-emitting areas relative to the luminance of the reference area. [Brief description of the drawings]

[0008] [Figure 1] 1 is a functional block diagram of a display device according to a first embodiment. [Diagram 2] 4 is a flowchart illustrating a process executed by a control device of the display device according to the first embodiment. [Diagram 3] 13 is a diagram for explaining a case where the level of the gradient of decrease in luminance in an adjacent area relative to the luminance in a reference area in the display device of the first embodiment is small. FIG. [Figure 4] 11 is a diagram illustrating a case where the level of the gradient of decrease in luminance in an adjacent area relative to the luminance in a reference area in the display device of the first embodiment is large. FIG. [Diagram 5] FIG. 11 is a functional block diagram of a display device according to a second embodiment. [Figure 6] 10 is a flowchart illustrating a process executed by a control device of the display device according to the second embodiment. [Figure 7] FIG. 11 is a functional block diagram of a display device according to a third embodiment. [Figure 8] 13 is a flowchart illustrating a process executed by a control device of the display device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a display device according to an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will not be repeated.

[0010] (Embodiment 1) The display device of the first embodiment will be described with reference to FIGS.

[0011] FIG. 1 is a functional block diagram of a display device 100 according to the first embodiment.

[0012] As shown in FIG. 1, the display device 100 includes a display panel 3 including a plurality of light-emitting areas, and a control device 10 that controls a plurality of light-emitting areas 3A (in FIGS. 3 and 4, only one light-emitting area is indicated by a reference symbol).

[0013] The display panel 3 displays an image. The display panel 3 has a plurality of light emitting areas 3A arranged in a matrix. Each of the plurality of light emitting areas 3A has the same size and is the same rectangular shape. In each of the plurality of light emitting areas 3A, a group of self-luminous elements is arranged in a matrix. In this embodiment, the self-luminous elements are OLEDs. However, the self-luminous elements may be QDs (Quantum Dots) instead of OLEDs.

[0014] The control device 10 receives an input video signal capable of identifying an image to be displayed using the display panel 3 from outside the display device 100. The control device 10 executes control for displaying an image on the display panel 3 based on the input video signal received from outside. The control device 10 controls the brightness of the plurality of self-luminous elements to display an image in the plurality of light-emitting areas 3A. The control device 10 includes a signal processing unit 1 and a brightness control unit 2.

[0015] The signal processing unit 1 receives an input video signal from the outside. Based on the input video signal received from the outside, the signal processing unit 1 obtains information on the display time of a video to be displayed on the display panel 3 in response to the input video signal. The signal processing unit 1 transmits the information on the display time of the video to the brightness control unit 2.

[0016] The luminance control unit 2 determines the level of the gradient of the luminance decrease when displaying an image, using information on the display time of the video received from the signal processing unit 1. The luminance control unit 2 controls the luminance of the display panel 3 using the determined level of the gradient of the luminance decrease. The level of the gradient of the luminance decrease is expressed as a ratio of the decrease in the luminance of the peripheral area to the luminance of the reference area. The reference area is, for example, the light-emitting area 3A at the center of the rectangular display panel 3, and the peripheral area is the light-emitting area 3A adjacent to the central light-emitting area 3A. When comparing the luminance of the light-emitting area 3A from the center to the edge of the peripheral area in the rectangular display panel 3, for example, the luminance of the light-emitting area 3A at the edge of the peripheral area is 80% (FIG. 3) or 75% (FIG. 4) of the luminance of the light-emitting area 3A at the center. Therefore, according to the control of the luminance control unit 2, it is possible to suppress the risk of burn-in at the edge of the display panel 3 where a logo is likely to be displayed.

[0017] In the present embodiment, the level of the gradient of the decrease in luminance of each light-emitting area 3A of rectangular display panel 3 means the gradient of the decrease in luminance of light-emitting area 3A at the edge of display panel 3 relative to the luminance of light-emitting area 3A at the center of display panel 3. In other words, in the present embodiment, the luminance of each light-emitting area 3A of rectangular display panel 3 decreases at a predetermined gradient from light-emitting area 3A at the center of display panel 3 to light-emitting area 3A at the edge of display panel 3.

[0018] FIG. 2 is a flowchart illustrating the process executed by the control device 10 of the display device 100 according to the first embodiment.

[0019] 2, in step S1, the signal processing unit 1 acquires information on the display time of the image to be displayed on the display panel 3 in response to the input video signal based on the received input video signal. Next, in step S2, the luminance control unit 2 determines whether or not the time specified by the display time information received from the signal processing unit 1 is a time period in which there are many broadcast programs with a high risk of burn-in. The luminance control unit 2 determines whether or not the time period is a time period in which there are many broadcast programs with a high risk of burn-in by, for example, determining whether or not the time period is a time period in which there are many morning information programs.

[0020] In step S2, it may be determined that the time specified by the display time information received by the signal processing unit 1 is not a time period in which there are many broadcast programs with a high risk of burn-in. In this case, in step S1, the signal processing unit 1 again acquires information on the display time of the video to be displayed on the display panel 3 in response to the input video signal based on the received input video signal.

[0021] On the other hand, in step S2, it may be determined that the time specified by the display time information received by the signal processing unit 1 is a time period during which there are many broadcast programs with a high risk of burn-in. In this case, in step S3, the luminance control unit 2 executes control to increase the level of the gradient of the luminance decrease. Specifically, the luminance of the light-emitting area is decreased more toward the end of the display panel 3 (changing from the luminance distribution in FIG. 3 to the luminance distribution in FIG. 4).

[0022] 3 is a diagram illustrating a case where the level of the gradient of the decrease in luminance of an adjacent area relative to the luminance of a reference area of ​​display device 100 of embodiment 1 is small. As can be seen from Fig. 3, the luminance of light-emitting area 3A in the center of display panel 3 is 100%, which is the highest, and the luminance of light-emitting area 3A at the edge of display panel 3 is the lowest. In Fig. 3, the level of the gradient of the decrease in luminance is relatively small compared to Fig. 4.

[0023] Fig. 4 is a diagram illustrating a case where the level of the gradient of the decrease in luminance of an adjacent area relative to the luminance of a reference area of ​​display device 100 of embodiment 1 is large. As can be seen from Fig. 4, the luminance of light-emitting area 3A in the center of display panel 3 is 100%, which is the highest, and the luminance of light-emitting area 3A at the edge of display panel 3 is the lowest. In Fig. 4, the level of the gradient of the decrease in luminance is relatively large compared to Fig. 3.

[0024] For example, since there are many programs that display logos such as clocks in the morning, luminance control unit 2 sets the level of the gradient of the luminance decrease to a higher level than in other time periods. In this case, for example, luminance control unit 2 reduces the luminance of the edges of display panel 3 by, for example, 5% to 10% in the morning compared to other time periods. In this case, luminance control unit 2 switches the level of the gradient of the luminance decrease of each light-emitting area 3A from that shown in FIG. 3 to that shown in FIG. 4.

[0025] As can be seen from the above, control device 10 determines the degree of risk of burn-in for the multiple light-emitting areas based on an input video signal received from outside. Thereby, control device 10 controls the luminance of the multiple light-emitting areas such that the higher the risk of burn-in, the greater the level of the gradient of the decrease in luminance of the peripheral area adjacent to the reference area among the multiple light-emitting areas 3A relative to the luminance of the reference area.

[0026] In the present embodiment, the two types of luminance distributions shown in FIG. 3 and FIG. 4 are used to specify the level of the gradient of the luminance decrease, but three or more luminance distributions may be used.

[0027] In this embodiment, the control device 10 determines the degree of risk of burn-in based on the time for which an image specified by an input video signal is displayed on the display panel. This is because it is empirically known whether there are many boundaries between areas with 100% brightness and areas with 0% brightness depending on the time for which an image is displayed on the display panel 3. The time for which this image is displayed on the display panel may be a time specified by a clock signal measured by a timer. However, the time for which this image is displayed on the display panel may also be a time specified by information on the time zone for displaying the image, which is included in the input video signal.

[0028] In general, in a display device that uses self-luminous elements to display an image, when there is a large amount of information such as a logo or a telop, there are many boundaries between white and black in the image, in other words, there are many boundaries between areas with 100% brightness and areas with 0% brightness. Therefore, burn-in in the area with 100% brightness stands out at the boundary line. In the case of OLED, burn-in occurs due to the difference in the degree of deterioration of the OLED as a light-emitting element. In an area with 0% brightness (black), the light-emitting element does not deteriorate. Therefore, burn-in stands out at the boundary between an area with 0% brightness (black) and an area with high brightness (where the light-emitting element is easily deteriorated). When a logo is displayed, the same position continues to emit the same color, which tends to cause a difference in the degree of deterioration between the light-emitting elements around the logo and the light-emitting elements inside the logo, making it easy for burn-in to occur in the display panel. Therefore, the brightness control unit 2 of the display device 100 of this embodiment executes brightness gradient control to intentionally lower the brightness of the edge of the screen of the display panel 3 where the logo is likely to be displayed. This is because there is a risk of burn-in in the display panel 3 if the light-emitting element emits light, even if it is at a low brightness.

[0029] However, according to display device 100 of the present embodiment described above, it is possible to prevent light emitting areas 3A arranged in a matrix from emitting light with unnecessary brightness. This makes it possible to extend the life of a group of light emitting elements constituting light emitting areas 3A. As a result, it is possible to extend the life of display panel 3.

[0030] (Embodiment 2) Display device 100 according to the second embodiment will be described with reference to Fig. 5 and Fig. 6. Note that the following description will not repeat the same points as those of display device 100 according to the first embodiment. Display device 100 according to the present embodiment differs from display device 100 according to the first embodiment in the following points.

[0031] FIG. 5 is a functional block diagram of a display device 100 according to the second embodiment.

[0032] The signal processing unit 1 of this embodiment also receives an input video signal. However, the signal processing unit 1 acquires information on the broadcast genre of the video to be displayed on the display panel 3 in response to the input video signal based on the received input video signal. Therefore, the signal processing unit 1 of this embodiment transmits the information on the broadcast genre of the video to the brightness control unit 2. Furthermore, the brightness control unit 2 uses the information on the broadcast genre of the video received from the signal processing unit 1 to determine the level of the gradient of the decrease in brightness.

[0033] For example, since many of the variety show or news broadcasting genres constantly display logos or subtitles, the brightness control unit 2 sets a steeper level of the gradient of the brightness decrease compared to broadcasting genres other than variety shows or news. Since variety show or news broadcasting genres include displays of text with high brightness and displays of text backgrounds with low brightness, there is a risk of burn-in of the text with high brightness being noticeable.

[0034] Therefore, when displaying video of the variety show or news broadcast genre, the brightness control unit 2 reduces the brightness toward the ends of the display panel 3 more (for example, by 5% to 10%) compared to when displaying video of other broadcast genres. This makes it possible to suppress burn-in not only in the light emitting area 3A that contains information such as characters, but also in the light emitting area 3A that does not contain information such as characters.

[0035] On the other hand, when displaying video of a broadcast genre that does not display logos or subtitles, such as a drama, the brightness control unit 2 may reduce the level of the slope of the brightness decrease or may not execute control to change the level of the slope of the brightness decrease.

[0036] FIG. 6 is a flowchart for explaining the process executed by the control device 10 of the display device 100 according to the second embodiment.

[0037] 6, in the display device 100 of the present embodiment, in step S11, the signal processing unit 1 acquires information on the broadcast genre of the video to be displayed on the display panel 3 in response to an input video signal received from the outside, based on the input video signal. Next, in step S12, the luminance control unit 2 determines whether or not the broadcast genre specified by the broadcast genre information included in the input video signal received from the signal processing unit 1 is a broadcast genre with a high risk of burn-in. To determine whether or not the broadcast genre is a broadcast genre with a high risk of burn-in, the luminance control unit 2 determines, for example, whether or not the broadcast genre is a variety show or news.

[0038] In step S12, it may be determined that the broadcast genre specified by the broadcast genre information included in the input video signal received from the signal processing unit 1 is not a broadcast genre with a high risk of burn-in. In this case, in step S11, based on the received input video signal, information on the broadcast genre of the video displayed on the display panel 3 corresponding to the input video signal is acquired again.

[0039] On the other hand, in step S12, it may be determined that the broadcast genre identified by the broadcast genre information included in the input video signal received from the signal processing unit 1 is a broadcast genre with a high risk of burn-in. In this case, in step S13, the luminance control unit 2 executes control to increase the level of the gradient of the luminance decrease. Specifically, the luminance is decreased more toward the ends of the display panel 3.

[0040] As can be seen from the above, the control device 10 of the present embodiment determines the degree of risk of burn-in based on the broadcast genre of the video identified by the input video signal. The display device 100 of the present embodiment can also extend the life of the display panel 3, similar to the display device 100 of the first embodiment.

[0041] (Embodiment 3) Display device 100 according to the third embodiment will be described with reference to Fig. 7 and Fig. 8. Note that the following description will not repeat the same points as those of display device 100 according to the first or second embodiment. Display device 100 according to the present embodiment differs from display device 100 according to the first or second embodiment in the following points.

[0042] FIG. 7 is a functional block diagram of a display device 100 according to the third embodiment.

[0043] The signal processing unit 1 of this embodiment also receives an input video signal. However, in this embodiment, the signal processing unit 1 acquires information on the broadcast program name of the video to be displayed on the display panel 3 corresponding to the input video signal based on the received input video signal. The signal processing unit 1 transmits the information on the broadcast program name of the video included in the input video signal to the luminance control unit 2. The luminance control unit 2 determines the level of the gradient of the luminance decrease using the information on the broadcast program name of the video included in the input video signal received from the signal processing unit 1.

[0044] When displaying video of a program that constantly displays a logo or a telop, the luminance control unit 2 increases the level of the gradient of the luminance decrease compared to when displaying video of programs other than the program. For example, when displaying video of a program that constantly displays a logo or a telop, the luminance control unit 2 decreases the luminance more toward the ends of the display panel 3 compared to when displaying video of programs other than the program. When displaying video of a program that does not display a logo or a telop, the luminance control unit 2 decreases the level of the gradient of the luminance decrease or does not execute control to change the level of the gradient of the luminance decrease.

[0045] FIG. 8 is a flowchart for explaining the process executed by the control device 10 of the display device 100 according to the third embodiment.

[0046] 8, in step S21, the signal processing unit 1 acquires information on the broadcast program name of the video displayed on the display panel 3 in response to the input video signal based on the received input video signal. Next, in step S22, the luminance control unit 2 determines whether or not the broadcast program name specified by the broadcast program name information included in the input video signal received from the signal processing unit 1 is a broadcast program name with a high risk of burn-in. To determine whether or not the broadcast program name is a broadcast program name with a high risk of burn-in, the luminance control unit 2 determines, for example, whether or not the broadcast program name is a broadcast program name that constantly displays a logo.

[0047] In step S22, it may be determined that the broadcast program name specified by the input video signal broadcast program name information received from the signal processing unit 1 is not a broadcast program name with a high risk of burn-in. In this case, in step S21, based on the received input video signal, the information on the broadcast program name of the video displayed on the display panel 3 corresponding to the input video signal is acquired again.

[0048] On the other hand, in step S22, it may be determined that the broadcast program name specified by the broadcast program name information included in the input video signal received from the signal processing unit 1 is a broadcast program name with a high risk of burn-in. In this case, in step S33, the luminance control unit 2 executes control to increase the level of the gradient of the luminance decrease. Specifically, the luminance is decreased more toward the end of the display panel 3.

[0049] As can be seen from the above, the control device 10 judges the degree of risk of burn-in based on the broadcast program name of the video identified by the input video signal. The display device 100 of the present embodiment can also extend the life of the display panel 3, similar to the display device 100 of the first embodiment. [Explanation of symbols]

[0050] 3 Display Panel 10 Control device 100 display device

Claims

1. a display panel including a plurality of light emitting areas; A control device for controlling the plurality of light emitting areas, The control device includes: determining a degree of risk of burn-in of the plurality of light-emitting areas based on an input video signal received from an external device; controlling the luminance of the plurality of light-emitting areas so that the level of the gradient of the decrease in luminance of a peripheral area adjacent to a reference area among the plurality of light-emitting areas relative to the luminance of the reference area is increased as the risk of burn-in increases; Display device.

2. the control device determines the degree of risk of burn-in based on a time for which an image specified by the input video signal is displayed on the display panel; The display device according to claim 1 .

3. The control device determines the degree of risk of burn-in based on a broadcast genre of a video identified by the input video signal. The display device according to claim 1 .

4. the control device determines the degree of risk of burn-in based on a broadcast program name of the video identified by the input video signal; The display device according to claim 1 .

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