Display device for vehicle

Abstract

To provide a display device for a vehicle capable of appropriately notifying a driver that luminance of a display image is adjusted.SOLUTION: A vehicle display device 1 includes a display 10 that displays a display image on a windshield of a vehicle such that the display image is superimposed on a real landscape in front of the vehicle, a navigation system 20 that displays a luminance setting screen for setting a luminance of the display image according to an operation input, a temperature sensor 11 that detects a temperature of the display 10, and a display controller 13 that adjusts the luminance of the display image based on a temperature detected by the temperature sensor 11. The display controller 13 performs control to lower the luminance of the display image when the detection temperature of the temperature sensor 11 exceeds the temperature threshold, and adds a warning image for warning the driver to the display image and displays the warning image when the value of the setting change of the luminance by the luminance setting function of the navigation system 20 exceeds the luminance threshold in a state where the luminance of the display image is lowered.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a display device for a vehicle. [Background technology]

[0002] A head-up display (HUD) mounted on a vehicle displays an image using, for example, a TFT device. When the TFT device becomes hot, the brightness of the backlight (B / L) may be automatically reduced to protect the TFT device. When the brightness of the display image is reduced, the driver viewing the display image feels uncomfortable, so when the brightness of the display image is reduced, an alarm or warning is issued (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-198540 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, some HUDs display a brightness setting screen on the meter, navigation system, etc., when the driver adjusts the brightness of the display image. In this case, the driver often adjusts the brightness while looking at the display image displayed in front of the driver, without looking at the brightness setting screen. Therefore, even if the brightness setting screen indicates that the brightness of the display image has been reduced to protect the TFT device, there is a possibility that the driver may miss this, leaving room for improvement.

[0005] An object of the present invention is to provide a vehicle display device that can appropriately notify a driver that the brightness of a displayed image has been adjusted. [Means for solving the problem]

[0006] In order to achieve the above object, the vehicle display device of the present invention comprises a display device that displays a display image on a projection target member of the vehicle by superimposing it on an actual scene in front of the vehicle; a brightness setter that displays a brightness setting screen that sets the brightness of the display image in response to an operational input from the driver; a temperature sensor that detects the temperature of the display device; and a display controller that adjusts the brightness of the display image based on the temperature detected by the temperature sensor, wherein the display controller controls to lower the brightness of the display image when the temperature detected by the temperature sensor exceeds a temperature threshold, and when the brightness of the display image is lowered and the value of the change in brightness by the brightness setter exceeds the brightness threshold, the display controller adds a warning image to the display image to warn the driver. [Effects of the Invention]

[0007] Advantageous Effects of Invention The vehicle display device according to the present invention has the advantage of being able to appropriately notify the driver that the brightness of the display image has been adjusted. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a general configuration of a vehicle equipped with a vehicle display device according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a schematic configuration around the front window of the vehicle shown in FIG. [Figure 3] FIG. 3 is a block diagram showing a schematic configuration of the vehicle display device according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram showing an example of a display image displayed by the vehicle display device according to the embodiment. [Figure 5] FIG. 5 is a flowchart illustrating an example of the operation of the vehicle display device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments. That is, the components in the following embodiments include those that can be easily imagined by a person skilled in the art or those that are substantially the same, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

[0010] [Embodiment] The vehicular display device 1 according to this embodiment shown in FIGS. 1 to 3 is, for example, a head-up display (HUD) mounted on a vehicle 100 such as an automobile. The vehicular display device 1 displays a display image S on a windshield 104 of the vehicle 100 by superimposing it on an actual scene ahead of the vehicle 100. Specifically, the vehicular display device 1 reflects the display image S using an optical system and projects it onto the windshield 104 of the vehicle 100, and a virtual image corresponding to the display image S projected onto the windshield 104 is viewed from the viewpoint (eye point EP) of a driver D of the vehicle 100. The windshield 104 is semi-transparent and reflects display light L incident from the vehicular display device 1 toward the eye point EP of the driver D.

[0011] The vehicle display device 1 is disposed, for example, inside an instrument panel 102 of the vehicle 100. The vehicle display device 1 is connected, for example, to a navigation system (hereinafter also referred to as a "navigation system") 20 mounted on the vehicle 100.

[0012] The navigation system 20 calculates the current position of the vehicle 100 based on satellite radio waves such as a GPS (Global Positioning System), and displays the current position and destination of the vehicle 100 together with map information and road information. The navigation system 20 has a display 20a that displays images. The display 20a is a touch panel type that allows operation input to the screen, and is provided, for example, on a dash panel, instrument panel, console, or the like inside the vehicle 100. The navigation system 20 is provided separately from the vehicle display device 1.

[0013] The navigation system 20 of this embodiment functions as a brightness setter. That is, in addition to a so-called navigation function, the navigation system 20 has a brightness setting function for setting the brightness of the display image S displayed by the vehicle display device 1 in accordance with an operation input by the driver D. The brightness setting function, for example, displays a brightness setting screen for the display image S on the display 20a, and the driver D changes the brightness of the display image S in accordance with an operation input to the brightness setting screen. The navigation system 20 outputs the changed brightness setting value to the vehicle display device 1 as data.

[0014] The vehicle display device 1 includes a display unit 10, a temperature sensor 11, and a display controller 13. The display controller 13 is connected to the display unit 10 and the temperature sensor 11.

[0015] The display device 10 displays a display image S on a windshield 104 of the vehicle 100, superimposing it on the actual scenery ahead of the vehicle 100. The display device 10 has a display device 10a, a backlight (B / L) 10b, and an optical system 10c.

[0016] The display device 10a is, for example, a liquid crystal panel made of a light-transmitting or light-semitransmitting TFT liquid crystal (Thin Film Transistor Liquid Crystal Display) etc. The display device 10a is illuminated from the rear side, causing the display surface on the front side to emit light.

[0017] The backlight 10b illuminates the display device 10a from the rear side. The backlight 10b is driven by power obtained from a battery (not shown) in the vehicle 100, for example, and is driven and controlled by the display controller 13.

[0018] The optical system 10c is configured with, for example, one or more reflecting mirrors. The optical system 10c is disposed on the optical path of the display light L from the display device 10a to the windshield 104, and reflects the display light L toward the windshield 104.

[0019] Next, the temperature sensor 11 will be described. The temperature sensor 11 detects the temperature of the display device 10, and is composed of, for example, a thermistor, a thermocouple, a resistance temperature detector (RTD), an IC temperature sensor, etc. The temperature sensor 11 is disposed in the internal space of the display device 10, and is disposed near the display device 10a or the backlight 10b. The temperature sensor 11 is electrically connected to the display controller 13, and outputs the temperature detected by the temperature sensor 11 to the display controller 13.

[0020] Next, the display controller 13 will be described. When the temperature detected by the temperature sensor 11 exceeds the temperature threshold, the display controller 13 controls to reduce the brightness of the display image S. Specifically, when the detected temperature is input from the temperature sensor 11, the display controller 13 compares it with a pre-stored temperature threshold. The temperature threshold is a reference temperature at which the display device 10 can emit display light L at an appropriate brightness. For example, the temperature threshold is the lower limit temperature of the operating temperature range at which the backlight 10b in the display device 10 can emit display light L at an appropriate brightness. This temperature threshold is different from the temperature at which the display device 10a may be damaged (here, referred to as the limit temperature), and the temperature threshold is less than the limit temperature. The display controller 13 determines whether to reduce the brightness of the display image S based on the comparison result between the temperature detected by the temperature sensor 11 and the temperature threshold. When the temperature detected by the temperature sensor 11 is equal to or lower than the temperature threshold, the display controller 13 reduces the brightness of the display image S. Here, when the brightness of the display image S is to be reduced, the display controller 13, for example, dims the display 10 or changes the reflection angle of the reflection mirror included in the optical system 10c. The display controller 13 is formed, for example, by an IC chip or the like, and is driven by power obtained from a battery in the vehicle 100.

[0021] In this embodiment, when the brightness of the display image S is reduced and the brightness setting change value (change value) made by the navigation system 20 exceeds the brightness threshold, the display controller 13 adds a warning image S2 to the display image S to warn the driver D. The display controller 13 receives the changed brightness setting value as data from the navigation system 20 and compares the changed brightness setting value with the brightness threshold. If the result of comparing the changed brightness setting value with the brightness threshold shows that the changed brightness setting value exceeds the brightness threshold, the display controller 13 adds the warning image S2 to the display image S and displays it. On the other hand, if the changed brightness setting value made in response to an operation input does not exceed the brightness threshold, the display controller 13 does not add the warning image S2 to the display image S. As shown in FIG. 4 , the display image S includes an information image S1 about the vehicle 100 to notify the driver D and a warning image S2. For example, when route guidance is being provided by the navigation system 20, the information image S1 includes an arrow image indicating the direction of travel, an image showing a vehicle ahead, and the like. The information image S1 includes the real-time vehicle speed and vehicle status of the vehicle 100. On the other hand, the warning image S2 includes a text image such as "Brightness is being limited due to high temperature of the HUD." If the warning image S2 is a text image, it is not limited to "Brightness is being limited due to high temperature of the HUD," and may be a text image using other wording. The warning image S2 may be not only a text image, but also a symbol, icon, or the like, as long as it can make the driver D understand that the brightness of the display image S has been adjusted.

[0022] The display controller 13 may display the warning image S2 in the same manner as the information image S1, or may display the warning image S2 in a manner different from that of the information image S1. Specifically, the warning image S2 may be displayed in the same color as that of the information image S1, or in a color different from that of the information image S1. When the warning image S2 is displayed in a color different from that of the information image S1, it is preferable that the warning image S2 be in a color that makes it easy for the driver D to notice (for example, orange, etc.). Furthermore, the display controller 13 may display the warning image S2 so that it flashes to an extent that does not bother the driver D.

[0023] Furthermore, the display controller 13 may increase the brightness of the display image S while the warning image S2 is being displayed. Since the brightness of the display image S is reduced while the warning image S2 is being displayed, the brightness of the display image S is increased to an extent that does not bother the driver D, thereby alerting the driver D. Furthermore, the display controller 13 and the display 10 may be configured to increase only the brightness of the warning image S2 or the surroundings including the warning image S2, rather than increasing the brightness of the entire display image S while the warning image S2 is being displayed.

[0024] Next, the operation of the display controller 13 in the vehicle display device 1 will be described with reference to the flowchart in Fig. 5. First, in step S1, the display controller 13 acquires a detected temperature from the temperature sensor 11. In step S2, the display controller 13 determines whether the acquired detected temperature is equal to or lower than the temperature threshold value. If the detected temperature is equal to or lower than the temperature threshold value, the process returns to step S1. On the other hand, if the detected temperature exceeds the temperature threshold value, the process proceeds to step S3.

[0025] In step S3, the display controller 13 dims the backlight (B / L) 10b to reduce the brightness of the display image S. Next, in step S4, the display controller 13 determines whether the brightness setting value has been changed to a brightness threshold or higher while the brightness setting screen for the display image S is displayed. If the changed brightness setting value is not equal to or higher than the brightness threshold, step S4 is repeated. On the other hand, if the changed brightness setting value is equal to or higher than the brightness threshold, the process proceeds to step S5.

[0026] In step S5, the display controller 13 displays a warning image S2 in addition to the display image S. After displaying the warning image S2, the display controller 13 starts a timer.

[0027] In step S6, the display controller 13 determines whether the display time of the warning image S2 has elapsed for a certain period of time. Specifically, the display controller 13 measures the time elapsed on the timer started in step S5, and determines whether the measured display time has elapsed for a certain period of time. If the display time of the warning image S2 has not elapsed for a certain period of time, step S6 is repeated. On the other hand, if the display time of the warning image S2 has elapsed for a certain period of time, the process proceeds to step S7.

[0028] In step S7, the display controller 13 hides the warning image S2 that was being displayed, and ends this process.

[0029] As described above, the vehicle display device 1 includes a display device 10, a navigation system 20 that displays a brightness setting screen for setting the brightness of the display image S in response to operational input from the driver D, a temperature sensor 11 that detects the temperature of the display device 10, and a display controller 13 that adjusts the brightness of the display image S based on the temperature detected by the temperature sensor 11.

[0030] When the temperature detected by the temperature sensor 11 exceeds the temperature threshold, the display controller 13 performs control to reduce the brightness of the display image S. This prevents the display unit 10 from being driven at a temperature exceeding the allowable temperature, and the vehicle display device 1 can protect the display unit 10 including the display device 10a from an increase in the environmental temperature.

[0031] Then, when the brightness setting change value on the brightness setting screen of the navigation system 20 exceeds the brightness threshold value while the brightness of the display image S is reduced, the display controller 13 adds a warning image S2 to the display image S. This allows the vehicular display device 1 to appropriately notify the driver D, who is adjusting the brightness while looking at the display image S, that the brightness of the display image S has been reduced without causing discomfort.

[0032] The display controller 13 displays the warning image S2 in a manner different from that of the information image S1. This allows the vehicular display device 1 to notify the driver D, who is adjusting the brightness while watching the display image S, that the brightness of the display image S has been lowered so that the driver D does not miss the warning image S2.

[0033] In the above embodiment, the vehicle display device 1 is connected to a navigation system 20 having a brightness setting function, a brightness setting screen is displayed on the display 20a of the navigation system 20, and the brightness of the display image S is changed in response to an operation input, but the present invention is not limited to this. For example, as shown in Figures 2 and 3, the vehicle display device 1 may be connected to a meter 21 having a brightness setting function, a brightness setting screen is displayed on the display 21a of the meter 21, and the brightness of the display image S may be changed in response to an operation input.

[0034] In addition, in the above embodiment, the navigation system 20 and the meter 21, which are configured separately from the vehicle display device 1, each have a brightness setting function that displays a brightness setting screen, but this is not limited to this.

[0035] Furthermore, in the above embodiment, the display controller 13 turns off the warning image S2 after a certain display time has elapsed since the warning image S2 was displayed, but this is not limited thereto. For example, the display controller 13A may be configured to vary the display time of the warning image S2 depending on the display position of the warning image S2, or may be configured to change the display position of the warning image S2 depending on the display content of the display image S. For example, if the display position of the warning image S2 is a position that the driver D looks at relatively frequently, the display time of the warning image S2 is relatively shortened. A position that the driver D looks at relatively frequently is, for example, a position that displays a text image such as a speed display or a position where the driver D's viewpoint (EP) movement is relatively small. In this case, even if the display time of the warning image S2 is relatively shortened, the driver D can easily recognize the warning image S2. On the other hand, if the display position of the warning image S2 is a position that the driver D looks at relatively infrequently, the display time of the warning image S2 is relatively lengthened. A position that the driver D looks at relatively infrequently is, for example, a position where the movement of the viewpoint (EP) of the driver D is relatively large. In this case, the display time of the warning image S2 is relatively long, thereby making it easier for the driver D to recognize the warning image S2.

[0036] 3, the vehicle display device 1 of the above embodiment may include an audio output device 14 connected to the display controller 13, and the display controller 13 may display the warning image S including the warning image S2, and may sound an alarm using the audio output device 14. The audio output device 14 is, for example, a speaker. This allows the vehicle display device 1 to effectively alert the driver D that the brightness of the display image S has been reduced. Note that the audio output device 14 may also be a speaker of the navigation system 20 or a speaker of the meter 21 mounted on the vehicle 100. [Explanation of symbols]

[0037] 1. Vehicle display device 10 Display 10a Display Device 11 Temperature Sensor 13 Display Controller 20 Navigation System 100 vehicles 104 Windshield S Display Image S2 Warning Image D. Driver

Claims

1. a display device that displays a display image on a projection target of the vehicle by superimposing the display image on an actual scene ahead of the vehicle; a brightness setting device that displays a brightness setting screen for setting the brightness of the display image in response to an operation input by a driver; a temperature sensor for detecting the temperature of the display; a display controller that adjusts the brightness of the display image based on the temperature detected by the temperature sensor; The display controller When the temperature detected by the temperature sensor exceeds a temperature threshold, a control is performed to reduce the brightness of the display image; When the value of the change in luminance by the luminance setter exceeds a luminance threshold value in a state where the luminance of the display image is reduced, a warning image for warning the driver is additionally displayed on the display image. A vehicle display device comprising:

2. The display controller The warning image is included in the display image and displayed, and a warning sound is sounded. The vehicle display device according to claim 1 .

3. The display image is an information image about the vehicle to be notified to the driver and the warning image, The display controller The warning image is displayed in a manner different from that of the information image. The vehicle display device according to claim 1 or 2.

4. The display controller The warning image is displayed and then turned off after a display time has elapsed, The display time is varied depending on the display position of the warning image in the display image. The vehicle display device according to claim 1 or 2.

5. The display and the brightness setting device are configured separately. The vehicle display device according to claim 1 or 2.

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