Display device temperature control device and display device temperature control method

Abstract

To properly control the internal temperature of a display device so as not to exceed an allowable upper limit temperature.SOLUTION: The display device is equipped with a temp. sensor 2 which measures the internal temp. of the LCD module 101 varying in the amt. of heat generation by the brightness and a CPU3 which lowers the brightness of the LCD module 101 when the internal temp. of the LCD module 101 measured by the temp. sensor 2 exceeds a prescribed first temp.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a display temperature control device and a display temperature control method for controlling the temperature of a display. [Background technology]

[0002] For example, when an LCD (Liquid Crystal Display) installed on the bridge of a ship is used in a high-temperature environment, the internal temperature of the LCD may rise and exceed the upper limit of the LCD's allowable temperature. It is known that the main cause of such an increase in the internal temperature of an LCD is heat generated by the LCD's backlight.

[0003] Meanwhile, there is known a video display device that performs power-saving operation when the available power supply is tight relative to the power demand (see, for example, Patent Document 1). This device comprises a display control means for controlling the LCD, a temperature sensor for measuring the ambient temperature, and a power-saving setting means for instructing the display control means to operate the LCD in power-saving mode (reducing the brightness of the backlight) when the temperature measured by the temperature sensor exceeds a first threshold value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-15774 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the device described in Patent Document 1 determines whether it is summer (whether the temperature is 24°C or higher) based on the ambient temperature, i.e., the air temperature, and if it is summer, reduces the brightness of the backlight. By reducing the brightness, it is possible to prevent the LCD from overheating and rising in temperature. However, LCDs installed on the bridge of a ship, for example, do not exceed the allowable upper limit temperature at normal summer temperatures (e.g., 24°C), and the internal temperature of the LCD is often higher than the air temperature. Therefore, if the technology described in Patent Document 1 is applied to prevent the internal temperature of the LCD from exceeding the allowable upper limit temperature, the backlight brightness may be reduced unnecessarily and frequently, or the internal temperature of the LCD may not be properly controlled.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a display temperature control device and a display temperature control method that can appropriately control the internal temperature of a display so that it does not exceed an allowable upper limit temperature. [Means for solving the problem]

[0007] In order to solve the above problem, the invention described in claim 1 is a display temperature control device characterized by comprising a temperature measurement means for measuring the internal temperature of a display, the amount of heat generated of which changes depending on the brightness, and a brightness adjustment means for reducing the brightness of the display when the internal temperature measured by the temperature measurement means exceeds a predetermined first temperature.

[0008] The invention described in claim 2 is characterized in that, in the display temperature control device described in claim 1, the brightness adjustment means increases the brightness after lowering the brightness when the internal temperature reaches a second temperature lower than the first temperature.

[0009] The invention of claim 3 is the display temperature control device of claim 1 or 2, wherein the luminance of the display can be adjusted in a plurality of gradations, the luminance table being a table indicating that the luminance increases as the gradation increases, and the device comprises a first luminance table in which the luminance increases more with each gradation, and a second luminance table in which the luminance increases less with each gradation than the first luminance table, and the luminance adjustment means adjusts the luminance of the display based on the first luminance table under normal conditions, and when the internal temperature exceeds the first temperature, adjusts the luminance of the display based on the second luminance table, thereby lowering the luminance of the display.

[0010] The invention described in claim 4 is a display temperature control method characterized by measuring the internal temperature of a display, the amount of heat generated of which changes depending on the brightness, and reducing the brightness of the display when the measured internal temperature exceeds a predetermined first temperature.

[0011] The invention described in claim 5 is characterized in that, in the display temperature control method described in claim 4, after the brightness is lowered, the brightness is increased when the internal temperature reaches a second temperature lower than the first temperature.

[0012] The invention of claim 6 is characterized in that, in the display temperature control method of claim 4 or 5, the luminance of the display can be adjusted in a plurality of gradations, and the luminance table is a table indicating that the luminance increases as the gradation increases, and the invention includes a first luminance table in which the luminance increases more with each gradation, and a second luminance table in which the luminance increases less with each gradation than the first luminance table, and the luminance of the display is adjusted based on the first luminance table under normal conditions, and when the internal temperature exceeds the first temperature, the luminance of the display is reduced by adjusting the luminance of the display based on the second luminance table. [Effects of the Invention]

[0013] According to the inventions of claims 1 and 4, when the internal temperature of the display exceeds a first temperature, the brightness of the display is reduced. In other words, when the temperature of the display itself becomes high, the brightness of the display is reduced, thereby reducing the internal temperature of the display. This makes it possible to properly control the internal temperature of the display so that it does not exceed the allowable upper limit temperature, without reducing the brightness unnecessarily or frequently.

[0014] According to the inventions of claims 2 and 5, after the brightness of the display is lowered, when the internal temperature of the display reaches a second temperature lower than the first temperature, the brightness is increased, so the internal temperature of the display does not frequently rise and fall above the first temperature, and the brightness does not frequently rise and fall. As a result, it is possible to maintain the display function (ease of viewing) of the display in a good condition.

[0015] According to the inventions of claims 3 and 6, the luminance of the display is normally adjusted based on a first luminance table, and when the internal temperature of the display exceeds a first temperature, the luminance of the display is adjusted based on a second luminance table in which the rate of increase in luminance relative to gradation is small. Therefore, even if the internal temperature of the display becomes high, the internal temperature of the display does not exceed the allowable upper limit temperature, and the user can adjust the luminance of the display by changing the gradation according to the environment, preference, etc. In other words, user convenience can be maintained even at high temperatures. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic block diagram showing a display temperature control device according to an embodiment of the present invention; [Figure 2] 3 is a diagram showing a first luminance table and a second luminance table stored in a CPU of the display temperature control device of FIG. 1. FIG. [Figure 3] FIG. 3 is a diagram showing the application range of the first luminance table and the second luminance table in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described below based on the illustrated embodiments.

[0018] 1 is a schematic block diagram showing a display temperature control device 1 according to an embodiment of the present invention. This display temperature control device 1 is a device that controls and manages the temperature of a display, the amount of heat generated of which changes depending on the brightness. In this embodiment, the display is described as an LCD module (LCD) 101 installed on the bridge of a ship, but other display devices may also be used. Here, the LCD module 101 has an LCD panel assembled with an LCD driver, power supply circuit, backlight, etc., and the amount of heat generated changes depending on the brightness of the backlight.

[0019] The display temperature control device 1 mainly includes a temperature sensor (temperature measuring means) 2 and a CPU (Central Processing Unit, brightness adjusting means) 3.

[0020] The temperature sensor 2 is a temperature measuring device that measures the internal temperature of the LCD module 101. That is, it is disposed inside the LCD module 101 to measure the temperature of the LCD module 101 itself, and may be of a contact type or a non-contact type as long as it can measure the internal temperature. Furthermore, multiple temperature sensors 2 may be disposed depending on the size of the LCD module 101 and variations in internal temperature depending on the part or location.

[0021] CPU 3 is a central processing unit that constantly monitors the internal temperature measured by temperature sensor 2 and adjusts the brightness according to the internal temperature of LCD module 101. That is, when the internal temperature of LCD module 101 exceeds a predetermined first temperature, it reduces the brightness of the backlight of LCD module 101. Thereafter, when the internal temperature of LCD module 101 reaches (drops to) a second temperature that is lower than the first temperature, it increases the brightness of the backlight of LCD module 101.

[0022] Here, the first temperature is a temperature that is lower than the upper limit temperature tolerance of LCD module 101, and when the internal temperature of LCD module 101 reaches the first temperature, the brightness of LCD module 101 is reduced so that the internal temperature of LCD module 101 does not exceed the upper limit temperature tolerance. The second temperature is a temperature that is lower than the first temperature, and when the internal temperature of LCD module 101 drops to the second temperature, the brightness of LCD module 101 is increased so that the internal temperature of LCD module 101 does not frequently fluctuate around the first temperature, and the brightness does not frequently fluctuate.

[0023] Specifically, in this embodiment, the ambient temperature range for use of the LCD module 101 is from -15°C to 55°C, and the upper limit temperature tolerance for the LCD module 101 is set to 70°C. With respect to this upper limit temperature tolerance, the first temperature is set to 65°C, and the second temperature is set to 55°C.

[0024] In this embodiment, the brightness of the backlight of the LCD module 101 can be adjusted in a plurality of gradation levels, and the brightness of the LCD module 101 is adjusted according to a brightness table. That is, the brightness table indicates the relationship between each gradation and brightness, indicating that the higher the gradation, the higher the brightness. As shown in Fig. 2, a first brightness table TB1 in which the degree of increase (rising tendency) of brightness relative to the gradation is greater, and a second brightness table TB2 in which the degree of increase of brightness relative to the gradation is smaller than that of the first brightness table TB1 are stored in the CPU 3.

[0025] In this embodiment, for the low gradations "0" to "11," the relationship between gradation and luminance is set to be the same in both the first luminance table TB1 and the second luminance table TB2. This is because, for gradations up to "11," the amount of heat generated from the LCD module 101 is small, and the internal temperature of the LCD module 101 does not exceed the upper allowable temperature limit. This makes it possible to suppress (reduce) luminance only at high luminance levels that require suppression of heat generation, thereby preventing unnecessary luminance suppression.

[0026] On the other hand, for the higher gradations "12" to "15," the luminance in the second luminance table TB2 is set lower than the luminance in the first luminance table TB1, even for the same gradation. That is, the luminance of each gradation in the second luminance table TB2 is set so that even if the internal temperature of the LCD module 101 exceeds the first temperature, the internal temperature of the LCD module 101 will not exceed the allowable upper limit temperature if the luminance is reduced to the luminance in the second luminance table TB2. Note that the second luminance table TB2 is also set so that the luminance increases as the gradation increases, allowing for brightness adjustment.

[0027] 3, the display temperature control device 1 configured as above adjusts the brightness of the LCD module 101 based on the first brightness table TB1 when the internal temperature of the LCD module 101 is normally below 65°C (first temperature). In other words, when the user changes the grayscale, the brightness is adjusted according to the first brightness table TB1.

[0028] On the other hand, when the internal temperature of the LCD module 101 exceeds 65°C, the brightness of the LCD module 101 is adjusted or suppressed (brightness is reduced) based on the second brightness table TB2. In other words, the brightness is changed to the brightness on the second brightness table TB2 that corresponds to the grayscale set at that time. For example, if the grayscale is "14" when the internal temperature exceeds 65°C, the brightness is reduced from the brightness of the grayscale "14" on the first brightness table TB1 to the brightness of the grayscale "14" on the second brightness table TB2. Note that when the grayscale is between "0" and "11," as described above, the brightness does not change even when the second brightness table TB2 is applied.

[0029] In this way, when the user changes the gradation while the second luminance table TB2 is being applied, the luminance is adjusted according to the second luminance table TB2. Thereafter, when the internal temperature of the LCD module 101 drops to 55°C (second temperature), the luminance of the LCD module 101 is again adjusted based on the first luminance table TB1 (increased). In other words, the luminance is changed to the luminance on the first luminance table TB1 that corresponds to the gradation set at that time. For example, if the gradation is "14" when the internal temperature drops to 55°C, the luminance of the gradation on the second luminance table TB2 is increased from "14" to "14" on the first luminance table TB1.

[0030] This display temperature control method is repeated depending on the internal temperature of the LCD module 101.

[0031] Thus, according to this display temperature control device 1 and display temperature control method, when the internal temperature of the LCD module 101 exceeds the first temperature (65°C), the brightness of the LCD module 101 is reduced. In other words, when the temperature of the LCD module 101 itself becomes high, the brightness of the LCD module 101 is reduced, thereby lowering the internal temperature of the LCD module 101. This makes it possible to properly control the internal temperature of the LCD module 101 so that it does not exceed the upper allowable temperature limit (70°C), without reducing the brightness unnecessarily or frequently or preventing the brightness from being reduced because the air temperature is low even though the internal temperature is high.

[0032] Furthermore, after the brightness of LCD module 101 is lowered, when the internal temperature of LCD module 101 reaches a second temperature (55°C) that is lower than the first temperature, the brightness is increased. This prevents the internal temperature of LCD module 101 from frequently fluctuating around the first temperature, which in turn prevents the brightness from frequently fluctuating. As a result, the display function (ease of viewing) of LCD module 101 can be maintained in a good condition.

[0033] Furthermore, under normal circumstances, the brightness of the LCD module 101 is adjusted based on the first brightness table TB1, and when the internal temperature of the LCD module 101 exceeds the first temperature, the brightness of the LCD module 101 is adjusted based on the second brightness table TB2, which has a smaller increase in brightness relative to the gradation. Therefore, even when the internal temperature of the LCD module 101 becomes high, the user can adjust the brightness of the LCD module 101 by changing the gradation according to the environment, preference, etc., while preventing the internal temperature of the LCD module 101 from exceeding the upper allowable temperature limit. In other words, user convenience can be maintained even at high temperatures.

[0034] Although the embodiments of the present invention have been described above, the specific configuration is not limited to the above embodiments, and design changes that do not depart from the gist of the present invention are also included in the present invention. For example, in the above embodiments, the luminance of the first luminance table TB1 and the luminance of the second luminance table TB2 are set to be the same for gradations from "0" to "11," but they may be set to be different. Furthermore, the first luminance table TB1 and the second luminance table TB2 may be stored in the LCD module 101, and the luminance tables TB1 and TB2 and gradations may be specified by the CPU 3 to the LCD module 101. [Explanation of symbols]

[0035] 101 LCD module (display) 1 Display temperature control device 2 Temperature sensor (temperature measurement means) 3 CPU TB1 First brightness table TB2 Second Luminance Table

Claims

1. a temperature measuring means for measuring the internal temperature of the display, the amount of heat generated of which changes depending on the brightness; a brightness adjusting means for reducing the brightness of the display when the internal temperature measured by the temperature measuring means exceeds a predetermined first temperature; A display temperature control device comprising:

2. the brightness adjusting means increases the brightness when the internal temperature reaches a second temperature lower than the first temperature after decreasing the brightness; 2. The display temperature control device according to claim 1.

3. a brightness table indicating that the brightness of the display device can be adjusted in a plurality of gradations, and that the higher the gradation, the higher the brightness; a first luminance table in which the degree of increase in luminance relative to the gradation is large, and a second luminance table in which the degree of increase in luminance relative to the gradation is smaller than that of the first luminance table; the luminance adjusting means adjusts the luminance of the display based on the first luminance table under normal conditions, and when the internal temperature exceeds the first temperature, adjusts the luminance of the display based on the second luminance table, thereby reducing the luminance of the display; 3. The display temperature control device according to claim 1, wherein the temperature of the display device is controlled by the temperature sensor.

4. Measure the internal temperature of the display, which changes in heat output depending on the brightness. When the measured internal temperature exceeds a predetermined first temperature, the brightness of the indicator is reduced. A display temperature control method comprising:

5. after decreasing the brightness, increasing the brightness when the internal temperature reaches a second temperature lower than the first temperature; 5. The display temperature control method according to claim 4.

6. a brightness table indicating that the brightness of the display device can be adjusted in a plurality of gradations, and that the higher the gradation, the higher the brightness; a first luminance table in which the degree of increase in luminance relative to the gradation is large, and a second luminance table in which the degree of increase in luminance relative to the gradation is smaller than that of the first luminance table; adjusting the luminance of the display based on the first luminance table under normal conditions, and adjusting the luminance of the display based on the second luminance table when the internal temperature exceeds the first temperature, thereby reducing the luminance of the display; 6. The display temperature control method according to claim 4, wherein the temperature of the display is controlled by the temperature sensor.

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