Lighting control device for vehicle

Abstract

To provide a lighting control device for a vehicle for enabling a driver to easily and visually recognize display content of a display device at an early stage in the case that the inside of a car suddenly becomes bright.SOLUTION: A display device for displaying information is provided in the inside of a vehicle. A control part shortens a time until starting to change the brightness of the display device from low brightness to high brightness more than a time until starting to shift a headlight from a turned-on state to a turned-off state (steps S6, S7) in the case that surrounding of the vehicle shifts from a dark state to a bright state (step S3). The control part sets a time until starting to change the brightness of the display device from low brightness to high brightness based on a vehicle speed in the case of shifting the surrounding of the vehicle from a dark state to a bright state. Higher the vehicle speed is, the control part shortens the time until starting to change the brightness of the display device from the low brightness to the high brightness in the case of shifting the surrounding of the vehicle from the dark state to the bright state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Patent Document 1 describes an automatic light control device that automatically turns on or off vehicle headlights. The automatic light function automatically turns on the headlights when the vehicle enters a dark place such as a tunnel, even during the day, and automatically turns off the headlights when the vehicle exits the dark place and the surroundings become bright. In addition, the brightness of the display screen of a navigation device or the like installed in the vehicle cabin and the illumination of the instrument panel are also switched in accordance with the turning on or off of the headlights. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-94125 Summary of the Invention [Problem to be solved by the invention]

[0004] The safety standards that will apply to new vehicles released after April 2020 are as follows: Headlights must be turned on within two seconds when the illuminance around the vehicle falls below 1,000 lux, and must be turned off within five to 300 seconds when the illuminance around the vehicle rises to 7,000 lux. The new standards also stipulate that there must be no manual on / off function while the vehicle is moving (though they can be turned off when the vehicle is stopped).

[0005] According to this safety standard, when the surroundings of a vehicle change from a dark state to a bright state of 7,000 lux or more, the headlights will not turn off for a minimum of five seconds. Therefore, the brightness of the display screens of navigation devices and instrument panels, which are linked to the turning on and off of the headlights, will not switch to a high brightness state for a minimum of five seconds.

[0006] During the day, when a vehicle moves from a bright place to a dark place and the headlights switch from off to on, the brightness of the display screen of a navigation system or the like switches from high to low. In this case, even if the lead time for the headlights and display screen to switch is one or two seconds, the driver can easily see the high-brightness display screen inside the vehicle just after it gets dark, so the driver does not feel stressed by the lead time until the display screen switches to low brightness.

[0007] On the other hand, during the day, when a vehicle moves from a dark place to a bright place and the headlights switch from on to off, the brightness of the display screen of the navigation system or the like switches from low to high. In this case, the lead time until the brightness of the display screen starts to switch from low to high can cause stress for the driver. This is because when the interior of the vehicle suddenly becomes bright, the pupils of the eyes cannot adjust in time, and the display screen of the navigation system or the like appears pitch black.

[0008] In the technology described in Patent Document 1, the brightness of the display screen of a navigation device or the like is switched in conjunction with the switching of headlights, and because the switching timing is the same, there is a problem in that if the interior of the vehicle suddenly becomes bright, the driver cannot easily and quickly see the content displayed on the display device.

[0009] The present invention has been made with the above-mentioned circumstances in mind, and aims to provide a vehicle lighting control device that allows the driver to quickly and easily see the contents of the display device when the interior of the vehicle suddenly becomes bright. [Means for solving the problem]

[0010] The present invention is a lighting control device for a vehicle that includes a light detection unit that detects the brightness around the vehicle, and a control unit that controls the turning on and off of the vehicle's headlights in accordance with the brightness around the vehicle detected by the light detection unit, wherein a display device that displays information is provided inside the vehicle, and the control unit is characterized in that, when the environment around the vehicle transitions from a dark state to a bright state, the control unit shortens the time it takes for the brightness of the display device to start changing from low brightness to high brightness compared to the time it takes for the headlights to start transitioning from a turned-on state to a turned-off state. [Effects of the Invention]

[0011] As described above, according to the present invention, a lighting control device for a vehicle can be provided that allows the driver to quickly and easily see the contents of the display device when the interior of the vehicle suddenly becomes bright. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram showing the configuration of a vehicle equipped with a vehicle lighting control device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart illustrating the operation of the vehicle lighting control device according to one embodiment of the present invention. [Figure 3] FIG. 3 is a brightness control map to which a vehicle lighting control device according to an embodiment of the present invention refers. [Figure 4] FIG. 4 is a diagram showing the timing of switching between headlights and display devices during operation of a vehicle lighting control device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] A vehicle lighting control device according to one embodiment of the present invention includes a light detection unit that detects the brightness of the vehicle's surroundings and a control unit that controls the turning on and off of the vehicle's headlights in accordance with the brightness of the vehicle's surroundings detected by the light detection unit, wherein a display device that displays information is provided inside the vehicle, and the control unit, when the vehicle's surroundings transition from a dark state to a bright state, shortens the time it takes for the control unit to start changing the brightness of the display device from low to high compared to the time it takes for the headlights to transition from a turned-on state to a turned-off state. This allows the driver to easily and quickly see the content displayed on the display device when the interior of the vehicle suddenly becomes bright. [Example]

[0014] Hereinafter, a vehicle equipped with a vehicle lighting control device according to an embodiment of the present invention will be described with reference to the drawings.

[0015] As shown in FIG. 1, a vehicle 1 includes an optical sensor 2, a vehicle speed sensor 3, a headlight 4, and a display device 5.

[0016] The light sensor 2 is provided, for example, near the front edge of the dashboard of the driver's seat and detects brightness. The vehicle speed sensor 3 detects the speed of the vehicle 1. The headlights 4 are provided at the front of the vehicle 1 and illuminate the area ahead.

[0017] The display device 5 is provided inside the vehicle 1 and displays information from a navigation device or an instrument panel (not shown). The display device 5 has a display screen (not shown) whose brightness can be changed.

[0018] The vehicle 1 is equipped with a control device 10. The control device 10 is configured by a computer unit having a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), flash memory, input ports, and output ports. The ROM of the computer unit stores various constants, various maps, and the like, as well as a program for causing the computer unit to function as the control device 10. That is, in the computer unit, the CPU executes the program stored in the ROM, causing the computer unit to function as the control device 10 in this embodiment.

[0019] The control device 10 includes a light detection unit 11 and a control unit 12. The light detection unit 11 detects the brightness of the surroundings of the vehicle 1 based on the detection signal of the light sensor 2.

[0020] The control unit 12 controls the turning on and off of the headlights 4 of the vehicle 1 in accordance with the brightness around the vehicle 1 detected by the light detection unit 11. In this way, the control unit 12 realizes a so-called auto light function. As a result, even during the day, the headlights 4 are automatically turned on when the vehicle 1 enters a dark place such as a tunnel, and the headlights 4 are turned off when the light returns. The control unit 12 also switches the brightness of the display devices 5, such as the navigation device and the instrument panel, in accordance with the turning on and off of the headlights 4.

[0021] Here, we will explain the safety standards regarding the automatic headlight function. The safety standards for the automatic headlight function, which apply to new vehicles released after April 2020, stipulate that the headlights must be turned on within two seconds when the illuminance around the vehicle falls below 1,000 lux, and must be turned off within five to 300 seconds when the illuminance around the vehicle rises to 7,000 lux. According to these regulations, the range between 1,000 lux and 7,000 lux functions as a hysteresis (dead band), preventing frequent headlight on / off switching and resulting in malfunctions when the light changes frequently. Furthermore, the minimum time required for turning off the headlights is set to "five seconds or more," preventing frequent on / off switching and resulting in malfunctions when the light changes frequently. Furthermore, this prevents unintentional headlight on / off switching and resulting in malfunctions when the light changes suddenly brightly around the vehicle. Therefore, a fixed interval of at least 5 seconds is absolutely necessary to avoid breakdowns and ensure safety. On the other hand, there is no reason to avoid breakdowns when switching the brightness of the display screen of a navigation system, etc., and safety standards do not stipulate a fixed interval. The brightness of the display screen is generally switched between low and high brightness in conjunction with the timing of the headlights being turned on or off.

[0022] However, if the illuminance around the vehicle suddenly increases to 7,000 lux or more, such as when exiting a tunnel, and the brightness of the display device 5 is not quickly changed to high brightness and is maintained at low brightness for five seconds or more, the driver will be looking at a dark, low-brightness display device 5 in a bright environment, making it difficult for the driver to see the display device 5 and causing stress to the driver.

[0023] Therefore, in this embodiment, the timing of switching the display device 5 from low brightness to high brightness is not linked to the timing of switching the headlights 4 from on to off, but is controlled separately from the control of the headlights 4.

[0024] When the surroundings of the vehicle 1 transition from a dark state to a bright state, the control unit 12 shortens the time it takes to start changing the brightness of the display device 5 from low to high compared to the time it takes to start changing the headlights 4 from a turned-on state to an turned-off state. In other words, when the surroundings of the vehicle 1 transition from a dark state to a bright state, the control unit 12 changes the brightness of the display device 5 from low to high earlier than the timing at which the headlights 4 transition from a turned-on state to an turned-off state, and changes the brightness to high before the minimum time (5 seconds) specified in the safety standards has elapsed.

[0025] When the surroundings of the vehicle 1 transition from a dark state to a bright state, the control unit 12 sets the time until the luminance of the display device 5 starts to change from low to high, according to the vehicle speed. In other words, when the surroundings of the vehicle 1 transition from a dark state to a bright state, the control unit 12 sets the timing for changing the luminance of the display device 5 from low to high, according to the vehicle speed.

[0026] When the surroundings of the vehicle 1 transition from a dark state to a bright state, the control unit 12 shortens the time it takes to start changing the luminance of the display device 5 from low to high as the vehicle speed increases. In other words, when the surroundings of the vehicle 1 transition from a dark state to a bright state, the control unit 12 advances the timing at which the luminance of the display device 5 is changed from low to high as the vehicle speed increases.

[0027] 2, the control operation of the control unit 12 for the headlights 4 and the display device 5 will be described. This operation is repeated at a predetermined cycle.

[0028] As shown in FIG. 2, the control unit 12 detects that the illuminance of the optical sensor 2 is less than 1000 lux (step S1).

[0029] Next, the control unit 12 determines whether the determination time is longer than t seconds. The determination time is the time that has elapsed since the illuminance became less than 1000 lux. Furthermore, t seconds is a predetermined threshold value.

[0030] If the determination time is shorter than t seconds (NO in step S2), the control unit 12 keeps the headlights 4 turned off (denoted as "AUTO LIGHT OFF" in the figure) and ends this operation. When keeping the headlights 4 turned off, the control unit 12 also keeps the brightness of the display device 5 at high brightness.

[0031] If the determination time is longer than t seconds (YES in step S2), the control unit 12 turns on the headlights 4 (denoted as "AUTO LIGHT ON" in the drawing). When turning on the headlights 4, the control unit 12 changes the brightness of the display device 5 to low brightness in conjunction with the turning on of the headlights 4.

[0032] Next, the control unit 12 detects that the illuminance of the light sensor 2 is 7000 lux or more (step S3).

[0033] Next, the control unit 12 separates the brightness control of the display device 5 from the automatic light control (step S4). Here, the link between the brightness control of the display device 5 and the control of automatically turning on or off the headlights 4 (automatic light control) is released.

[0034] Next, the control unit 12 calculates the time until the luminance of the display device 5 starts to be switched to "high brightness" (step S5). Here, the control unit 12 refers to the luminance control map shown in FIG. 3 and calculates the time (so-called lead time) from when the illuminance is detected to be 7000 lux or more until the luminance of the display device 5 starts to be switched to "high brightness" according to the vehicle speed. In the luminance control map shown in FIG. 3, the time until the luminance of the display device 5 starts to be switched to "high brightness" is set to be shorter than the time until the headlights 4 start to be turned off (the minimum time specified in the safety standards). Furthermore, the time until the change to high brightness starts becomes shorter as the vehicle speed increases. Note that in FIG. 3, the time is set to become shorter in stages as the vehicle speed increases, but the time may also be set to become continuously shorter as the vehicle speed increases.

[0035] Next, the control unit 12 changes the brightness of the display device 5 to high brightness (denoted as "strong brightness" in the drawing) (step S6).

[0036] Next, the control unit 12 switches the headlights 4 off (denoted as OFF in the drawing) (step S7). This step S7 is carried out after the minimum time (5 seconds) specified in the safety standards has elapsed.

[0037] Next, the control unit 12 restores the link between the brightness control of the display device 5 and the auto light control (step S8), and ends this operation.

[0038] The timing of switching the headlights 4 and the display device 5 by the control unit 12 will be described with reference to FIG.

[0039] 4, when the control unit 12 detects that the illuminance is less than 1000 lux, the control unit 12 switches the headlights 4 from OFF to ON using the auto light function at the timing when a predetermined lead time conforming to safety standards has elapsed (indicated as ON / OFF switching in the figure).The control unit 12 also changes the display device 5 from high brightness (indicated as bright in the figure) to low brightness (indicated as dark in the figure) at the same timing when the predetermined lead time has elapsed.

[0040] On the other hand, when the control unit 12 detects that the illuminance is 7000 lux or more, the control unit 12 switches the headlights 4 from ON to OFF using the auto light function after a predetermined lead time in accordance with safety standards has elapsed. Also, the control unit 12 changes the brightness of the display device 5 from low to high at a timing ΔT earlier than the predetermined lead time has elapsed.

[0041] As described above, in this embodiment, the display device 5 that displays information is provided inside the vehicle 1. When the surroundings of the vehicle 1 change from a dark state to a bright state, the control unit 12 shortens the time it takes to start changing the brightness of the display device 5 from low to high, compared to the time it takes to start changing the headlights 4 from a turned-on state to a turned-off state.

[0042] As a result, when the surroundings of the vehicle 1 change from a dark state to a bright state, the time taken for the brightness of the display device 5 to start changing from low to high is shorter than the time taken for the headlights 4 to start changing from a lit state to an extinguished state, so that when the inside of the vehicle suddenly becomes bright, the driver can easily and quickly see the contents displayed on the display device 5.

[0043] In addition, in this embodiment, when the surroundings of the vehicle 1 change from a dark state to a bright state, the control unit 12 sets the time until the brightness of the display device 5 starts to change from low to high depending on the vehicle speed.

[0044] As a result, when the surroundings of the vehicle 1 change from a dark state to a bright state, the time until the brightness of the display device 5 starts to change from low to high is set according to the vehicle speed, so that the control can be tailored to the driver's physical sensation.

[0045] In addition, in this embodiment, when the surroundings of the vehicle 1 change from a dark state to a bright state, the control unit 12 shortens the time it takes to start changing the brightness of the display device 5 from low to high, as the vehicle speed increases.

[0046] As a result, when the surroundings of the vehicle 1 change from a dark state to a bright state, the time until the brightness of the display device 5 starts to change from low to high becomes shorter as the vehicle speed increases, thereby reducing stress on the driver.

[0047] In other words, the higher the vehicle speed, the longer the lead time felt from when the surroundings of the vehicle 1 change from a dark state to a bright state until the brightness of the display device 5 starts to change from low to high brightness, which causes stress, but stress can be reduced by shortening the lead time as the vehicle speed increases.

[0048] In addition, when vehicle 1 travels on a road on which buildings that block sunlight are installed at regular intervals, if vehicle 1 moves from inside the building to outside the building and the vehicle speed is low, it will take a long time for the vehicle to move from outside the building back inside the building. When the surroundings of vehicle 1 change from a dark state to a bright state, the slower the vehicle speed, the longer the time until the brightness of display device 5 starts to change from low to high, so frequent changes in brightness of display device 5 can be avoided, eliminating annoyance to the driver.

[0049] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0050] 1 vehicle 4. Headlights 5 Display device 11 Light detection unit 12 Control Unit

Claims

1. a light detection unit that detects the brightness around the vehicle; a control unit that controls turning on and off headlights of the vehicle in accordance with the brightness of the surroundings of the vehicle detected by the light detection unit, A display device for displaying information is provided inside the vehicle, The vehicle lighting control device is characterized in that, when the surroundings of the vehicle transition from a dark state to a bright state, the control unit shortens the time it takes for the brightness of the display device to start changing from low brightness to high brightness compared to the time it takes for the headlights to start transitioning from a turned-on state to a turned-off state.

2. The control unit 2. The vehicle lighting control device according to claim 1, wherein when the surroundings of the vehicle change from a dark state to a bright state, the time until the brightness of the display device starts to change from low brightness to high brightness is set according to the vehicle speed.

3. The control unit 3. The vehicle lighting control device according to claim 2, wherein when the surroundings of the vehicle transition from a dark state to a bright state, the time until the brightness of the display device starts to change from low brightness to high brightness is shortened as the vehicle speed increases.

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