Patent Application
20250078704
This application claims priority under Section 119 of U.S.C. to Japanese Patent Application No. 2023-139697 filed on Aug. 30, 2023, the entire content of which is incorporated herein by reference.
The disclosure relates to an image display device and an abnormality monitoring system for the image display device.
An image display device includes a circuit configuration for determining whether there is an abnormality.
According to one aspect of the disclosure, an image display device includes multiple display panels, a power supply unit, an image data input unit, a predicted current amount calculator, an actual current amount measurement unit, a current comparison unit, and an abnormality determiner. The multiple display panels each include multiple light-emitting elements. The power supply unit supplies power to each of the multiple display panels for displaying an image. The image data input unit inputs image data to each of the multiple display panels for displaying an image. The predicted current amount calculator calculates a predicted current amount in each of the multiple display panels based on image data input to each of the multiple display panels. The actual current amount measurement unit measures an actual current amount for each of the multiple display panels. The current comparison unit compares the predicted current amount with the actual current amount in each of the multiple display panels. The abnormality determiner determines whether there is an abnormality in each of the multiple display panels based on a result of comparison.
Embodiments of the disclosure will be described below with reference to the drawings. In the drawings, the same or equivalent components are denoted by the same reference numerals and signs, and description thereof will not be repeated. Further, in the following description, even when terms such as “vertical” or “horizontal” may be used to indicate a specific position and direction, these terms are used for convenience in order to facilitate understanding of the contents of the embodiments, and have no relation to the direction in which the embodiments are actually implemented.
An image display device 100 according to a first embodiment will be described below with reference to
First, an outline of the image display device 100 will be described with reference to
As illustrated in
The image display device 100 will be described in detail below with reference to
As illustrated in
Each of the multiple display panels 1 includes multiple light-emitting elements L. The power supply unit 20 supplies power to each of the multiple display panels 1 for displaying an image. The image data input unit 30 inputs image data to each of the multiple display panels 1 for displaying an image.
As illustrated in
The predicted current amount calculator 33 calculates a predicted current amount in each of the multiple display panels 1 based on image data input to each of the multiple display panels 1. The actual current amount measurement unit 24 measures an actual current amount for each of the multiple display panels 1.
The current comparison unit 34 compares the predicted current amount with the actual current amount in each of the multiple display panels 1. The abnormality determiner 35 determines whether there is an abnormality in each of the multiple display panels 1 based on a result of comparison.
Thus, while each of the multiple display panels 1 displays an image, the predicted current amount is compared with the actual current amount to determine whether there is an abnormality in each of the multiple display panels 1. As a result, the image display device 100 can quickly detect an abnormality that is difficult to find visually.
Each module 10 will be described in detail below with reference to
As illustrated in
Each module 10 further includes a HUB 11, a field programmable gate array (FPGA) 13, and a power supply board 12.
The HUB 11 receives image data (video signals) to be displayed on all the modules 10 from the image data input unit 30 directly or via an adjacent module 10. The HUB 11 branches image data (video signals) to be displayed on each module 10 from the image data (video signals) to be displayed on all the modules 10. The HUB 11 transmits the image data to be displayed on each module 10 to the FPGA 13 using low voltage differential signaling (LVDS). On the other hand, the HUB 11 transmits the image data (video signals) to be displayed on all the modules 10 to another module 10.
The FPGA 13 is a device in which logic circuits (gates) are integrated. The FPGA 13 also includes memory elements. The memory elements are logic circuits, such as flip-flops, that temporarily store required data.
The FPGA 13 includes an image data segmenter 31, and the predicted current amount calculator 33, the current comparison unit 34, and the abnormality determiner 35 described above. The FPGA 13, including the predicted current amount calculator 33, the current comparison unit 34, and the abnormality determiner 35, has the following two advantages. A first advantage is that it is not necessary to provide separate devices for the predicted current amount calculator 33, the current comparison unit 34, and the abnormality determiner 35. A second advantage is that determination of whether there is an abnormality is even faster.
The image data segmenter 31 receives image data to be displayed on each module 10 from the HUB 11. The image data segmenter 31 segments image data to be displayed on each display panel 1 from the image data to be displayed on each module 10. The image data segmenter 31 transmits image data to be displayed on each display panel 1 to each display panel 1 via a serial peripheral interface (SPI) bus.
The power supply board 12 receives power from the power supply unit 20 directly or via an adjacent module 10. The power supply board 12 includes power supply relays (not illustrated). The power supply board 12 distributes the supplied power to the respective display panels 1 via the power supply relays. On the other hand, the power supply board 12 also supplies the received power to another module 10.
With reference to
First, image data input to one display panel 1 will be described.
The image data input to one display panel 1 includes information for each of light-emitting elements L constituting one display panel 1. Each light-emitting element L is a pixel and therefore displays one color. One color displayed by each light-emitting element L is a combination of multiple primary colors. A grayscale value for each of the multiple primary colors to be combined is set according to a color to be displayed by the light-emitting element L. Therefore, the information for each light-emitting element L in the image data is the set grayscale value and the maximum possible grayscale value for each of the multiple primary colors.
Here, a specific example focusing on one light-emitting element L will be described. The primary colors to be combined are red (R), green (G), and blue (B). For each of the multiple (three) primary colors, the maximum possible grayscale value is 256. Therefore, for each of the multiple primary colors, the set grayscale value is one grayscale value of 0 to 256. For example, as shown in Table 1, the set grayscale value is a grayscale value of 64 for red (R), a grayscale value of 128 for green (G), and a grayscale value of 32 for blue (B).
In the predicted current amount calculator 33, the maximum current amount value for each primary color is input in advance. The predicted current amount calculator 33 calculates a predicted current amount in each light-emitting element L (hereinafter, individual predicted current amount) for each primary color. To be specific, the predicted current amount calculator 33 multiplies, for each primary color, a value of the maximum current amount by a value obtained by dividing the set grayscale value by the maximum possible grayscale value. Thus, the predicted current amount calculator 33 calculates the individual predicted current amount for each primary color. Then, the predicted current amount calculator 33 calculates an individual predicted current amount in one target light-emitting element L from the sum of the individual predicted current amounts for the respective primary colors.
In the example shown in Table 1, for red (R), the predicted current amount calculator 33 multiplies 20 mA, which is the value of the maximum current amount, by a value obtained by dividing 64, which is the set grayscale value, by 256, which is the possible maximum grayscale value. Accordingly, for red (R), the individual predicted current amount is 20 mA×64/256 (i.e., 5 mA). Similarly, for green (G), the predicted current amount calculator 33 multiplies 20 mA, which is the value of the maximum current amount, by a value obtained by dividing 128, which is the set grayscale value, by 256, which is the maximum possible grayscale value. Accordingly, for green (G), the individual predicted current amount is 20 mA×128/256 (i.e., 10 mA). Similarly, for blue (B), the predicted current amount calculator 33 multiplies 20 mA, which is the value of the maximum current amount, by a value obtained by dividing 32, which is the set grayscale value, by 256, which is the maximum possible grayscale value. Accordingly, for blue (B), the individual predicted current amount is 20 mA×32/256 (i.e., 2.5 mA). Then, the predicted current amount calculator 33 calculates 5 mA+10 mA+2.5 mA (i.e., 17.5 mA) as the sum of the individual predicted current amounts for the respective primary colors. The individual predicted current amount in one target light-emitting element L in Table 1 is 17.5 mA.
The predicted current amount calculator 33 calculates, for each light-emitting element L, the individual predicted current amounts of all the light-emitting elements L included in one target display panel 1. Then, the predicted current amount calculator 33 calculates the predicted current amount in one target display panel 1 from the sum of the individual predicted current amounts for the respective light-emitting elements L.
The actual current amount measurement unit 24 is an ammeter. Although details of the actual current amount measurement unit 24 are omitted in
The actual current amount measurement unit 24 includes a shunt resistor and a voltage measurement unit, both of which are not illustrated. The shunt resistors are provided in series on paths through which power is supplied from the power supply board 12 to the respective display panels 1. The voltage measurement unit measures a voltage difference between both ends of the shunt resistor. The actual current amount is measured from a resistance value of the shunt resistor and the voltage difference measured by the voltage measurement unit. The actual current amount is converted into digital data by an analog-to-digital converter (ADC) (not illustrated), and is input to the current comparison unit 34.
As a comparison between the predicted current amount and the actual current amount, the current comparison unit 34 divides the actual current amount by the predicted current amount. The current comparison unit 34 transmits a value obtained by dividing the actual current amount by the predicted current amount, that is, a ratio of the actual current amount to the predicted current amount, to the abnormality determiner 35.
The abnormality determiner 35 determines that there is an abnormality in the display panel 1 when the ratio of the actual current amount to the predicted current amount exceeds a first threshold value.
Therefore, when the actual current amount is large enough to correspond to a malfunction, that is, when the display panel 1 is bright enough to correspond to a malfunction, it is determined that there is an abnormality. The image display device 100 can quickly detect an abnormality in which the display panel 1 is bright enough to correspond to a malfunction.
The abnormality determiner 35 determines that there is an abnormality in the display panel 1 when the ratio of the actual current amount to the predicted current amount is smaller than a second threshold value.
Therefore, when the actual current amount is small enough to correspond to a malfunction, that is, when the display panel 1 is dark enough to correspond to a malfunction, it is determined that there is an abnormality. The image display device 100 can quickly detect an abnormality in which the display panel 1 is dark enough to correspond to a malfunction.
The first threshold value is, for example, preferably in a range of 120% to 140%, and more preferably 130%. The second threshold value is preferably, for example, in a range of 60% to 80%, and more preferably 70%.
The abnormality determiner 35 may be configured to set both the first threshold value and the second threshold value, or may be configured to set one of the first threshold value and the second threshold value.
Operations of the image display device 100 will be described below with reference to
As illustrated in
In step S4, the predicted current amount calculator 33 selects one light-emitting element L for which an individual predicted current amount has not been calculated. In step S5, the predicted current amount calculator 33 calculates the individual predicted current amount of the selected light-emitting element L. In step S6, the predicted current amount calculator 33 calculates the sum of the individual predicted current amounts calculated so far for one target display panel 1.
In step S7, the predicted current amount calculator 33 determines whether there is any light-emitting element L for which an individual predicted current amount has not been calculated. If there is a light-emitting element L for which the individual predicted current amount has not been calculated (Yes in step S7), the process returns to step S4. If there is no light-emitting element L for which the individual predicted current amount has not been calculated (No in step S7), the process proceeds to step S8. In step S8, the predicted current amount calculator 33 makes the sum of the individual predicted current amounts as the predicted current amount.
In step S9, the actual current amount measurement unit 24 measures an actual current amount of power supplied to the one target display panel 1.
In step S10, the current comparison unit 34 compares the predicted current amount with the actual current amount by dividing the actual current amount by the predicted current amount.
In step S11, the abnormality determiner 35 determines whether the ratio of the actual current amount to the predicted current amount exceeds the first threshold value. If the ratio of the actual current amount to the predicted current amount exceeds the first threshold value (Yes in step S11), the process proceeds to step S12. If the ratio of the actual current amount to the predicted current amount does not exceed the first threshold value (No in step S11), the process proceeds to step S13.
In step S12, the abnormality determiner 35 determines that there is an abnormality in the target display panel 1 because it is bright enough to correspond to a malfunction. After step S12, the process proceeds to step S15.
In step S13, the abnormality determiner 35 determines whether the ratio of the actual current amount to the predicted current amount is less than the second threshold value. If the ratio of the actual current amount to the predicted current amount is less than the second threshold value (Yes in step S13), the process proceeds to step S14. If the ratio of the actual current amount to the predicted current amount is not less than the second threshold value (No in step S13), the process proceeds to step S15.
In step S14, the abnormality determiner 35 determines that there is an abnormality in the target display panel 1 because it is dark enough to correspond to a malfunction. After step S14, the process proceeds to step S15.
In step S15, if the power remains ON (Yes in step S15), the process returns to step S1, and if the power is OFF (No in step S15), the process ends.
Next, an image display device 100 according to a second embodiment will be described with reference to
As illustrated in
Therefore, when it is determined that there is an abnormality, a notification is sent to the external device, so that the image display device 100 can extremely quickly detect the abnormality that is difficult to find visually.
The notification by the notification unit 50 is, for example, an alert or e-mail transmission. For example, the notification unit 50 issues a notification by transmitting an abnormality signal to the external device or the like.
Next, the abnormality monitoring system 200 for the image display device 100 will be described with reference to
As illustrated in
Therefore, when it is determined that there is an abnormality, a notification is sent to the monitoring center 150, so that the abnormality monitoring system 200 for the image display device 100 can exceedingly quickly detect the abnormality that is difficult to find visually.
The embodiments of the disclosure have been described above with reference to the drawings. However, the disclosure is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist of the disclosure. In addition, various disclosures can be formed by appropriately combining the multiple constituent elements disclosed in the above-described embodiments. For example, some of the constituent elements illustrated in the embodiments may be omitted. In order to facilitate understanding, the drawings are illustrated schematically, focusing on the respective constituent elements, and thicknesses, lengths, numbers, distances, and the like of the illustrated constituent elements are different from actual ones for convenience of creating drawings. In addition, the shapes and other features of the respective constituent elements illustrated in the above-described embodiments are merely examples and are not limited, and various changes can be made without substantially departing from the configuration of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-139697 | Aug 2023 | JP | national |
