VEHICULAR DISPLAY CONTROL DEVICE

The vehicular display control device is mounted on an autonomous driving vehicle provided with a windshield display. The windshield display is configured to change a transmittance of external light. The vehicular display control device includes a transmittance control unit configured to reduce the transmittance in order to promote a sleep of at least one passenger.

TECHNICAL FIELD

The present disclosure relates to a display control device mounted on a vehicle.

BACKGROUND

In recent years, with the development of automatic driving technology of vehicles, a technology for improving the comfort in the vehicle compartment has been proposed. In a conceivable technique, various information presentation devices such as a digital mirror and a head-up display are proposed. In addition, a windshield display that displays information on the entire surface of the windshield overlapped on the background has also been proposed.

SUMMARY

According to an example embodiment, a vehicular display control device is mounted on an autonomous driving vehicle provided with a windshield display. The windshield display is configured to change a transmittance of external light. The vehicular display control device includes a transmittance control unit configured to reduce the transmittance in order to promote a sleep of at least one passenger.

DETAILED DESCRIPTION

It is thought that fully autonomous driving will be possible in the future. In a vehicle in which fully autonomous driving is performed, it may be desirable to develop a vehicle compartment environment so that passengers including the driver can effectively use the vehicle compartment. As a result of detailed examination by the present inventors, it has been found that the above-mentioned technology is insufficient to establish a vehicle compartment environment.

In view of the above points, it may be desirable that a vehicle compartment environment suitable for passengers can be established by using a windshield display. The vehicular display control device of one aspect of the present embodiments is mounted on an autonomous vehicle provided with a windshield display. The windshield display is configured so that the transmittance of external light can be changeable. The vehicular display control device includes a transmittance control unit configured to reduce the transmittance in order to promote the sleep of at least one passenger.

According to the vehicle display control device of one aspect of the present embodiments, the transmittance of the windshield display is reduced in order to promote the sleep of the passenger. By reducing the transmittance of the windshield display, the incident of outside light into the vehicle compartment is suppressed. Therefore, the passenger can quickly fall asleep and take a sufficient nap in the passenger compartment. That is, by controlling the windshield display as an environment establishment device in the vehicle compartment, it is possible to establish a vehicle compartment environment suitable for the passengers.

Hereinafter, exemplary embodiments for implementing the present disclosure will be described with reference to the drawings.

First Embodiment

<1. Configuration of Vehicle Compartment Environment Establishment System>

First, the configuration of the vehicle compartment environment establishment system100according to the present embodiment will be described with reference toFIGS. 1 and 2. The vehicle compartment environment establishment system100is mounted on the autonomous driving vehicle200. In the present embodiment, the autonomous driving vehicle200is capable of autonomous driving at level4or higher according to the Society of Automotive Engineers standard.

The vehicle compartment environment establishment system100includes an electronic control unit (hereinafter, ECU)10, a peripheral monitoring sensor11, a biological sensor20, an illuminance sensor15, an electronic shutter16, a windshield display (hereinafter, WSD)17, and an illuminator18.

The peripheral monitoring sensor11is a sound wave sensor (that is, sonar), a laser radar, a millimeter wave radar, an image sensor, or the like. The peripheral monitoring sensor11is mounted, for example, in the center of the front bumper of the autonomous driving vehicle200, or on the left side or the right side of the front bumper. The peripheral monitoring sensor11detects obstacles such as other vehicles existing around the autonomous driving vehicle200, and transmits the detection information to the ECU10.

The biosensor20is a sensor that detects the biometric information of the passenger, and includes an IR sensor12, a heartbeat sensor13, and a driver status monitor (hereinafter, DSM)14. In the present embodiment, the biometric information includes the body temperature, facial expression, and heartbeat of the passenger.

The IR sensor12corresponds to a radiation thermometer that absorbs infrared rays emitted by an passenger and measures the body temperature of the passenger. The IR sensor12is mounted in the center and above the vehicle width direction, for example, inside the front windshield25. When a plurality of passengers get on the autonomous driving vehicle200, the IR sensor12measures the body temperature of each passenger. Then, the IR sensor12measures the body temperature of the passenger at a predetermined cycle, and transmits the measured temperature information to the ECU10.

The DSM14corresponds to a camera that captures a facial image of an passenger including a driver. The DSM14is mounted in the center and above the vehicle width direction, for example, inside the front windshield25. When a plurality of passengers are on the autonomous driving vehicle200, the DSM14captures a face image including the faces of the plurality of passengers. Alternatively, the DSM14may be equipped with a camera provided for each seat. The DSM14captures a face image of the passengers at a predetermined cycle, and transmits the captured face image of the passengers to the ECU10.

The heart rate sensor13is a sensor that detects the pulse of the passenger. The heart rate sensor13is mounted at a position where the passenger comes into contact with each seat of the autonomous driving vehicle200. Specifically, the heart rate sensor13is mounted on the armrest that the passenger's arm contacts and the seat surface that the passenger's femoral portion contacts, and detects the pulse of the passenger's arm and thigh. The heart rate sensor13detects the passenger's pulse information (that is, heart rate information) at a predetermined cycle, and transmits the detected pulse information to the ECU10.

The biosensor20may not include the heart rate sensor13. In this case, the movement of the blood vessels of the face may be detected from the facial image of the passenger taken by the DSM14, and the pulse may be calculated.

The illuminance sensor15is a sensor that detects the illuminance of light. The illuminance sensor15is mounted in a place that receives a large amount of external light, such as the inside of the front windshield25or the back side of the rear view mirror, and detects the illuminance of the external light. The illuminance sensor15detects the illuminance at a predetermined cycle and transmits the detected irradiation amount information to the ECU10. In this embodiment, the illuminance information corresponds to the external environmental information.

The electronic shutter16is made of a plurality of film members, and is attached to the entire windshields25on the front side, the left side, the right side, and the rear side in a grid pattern. Each film member has, for example, a square shape. The transmittance of the electronic shutter16can be changed stepwise by applying a voltage. The electronic shutter16may be built in the windshield25. That is, the windshield25may be configured so that the transmittance can be changed stepwise by applying a voltage.

The WSD17projects display light indicating various information onto the windshields25on the front side, the left side, the right side, and the rear side of the autonomous driving vehicle200. As a result, the display light reflected by the electronic shutter16and the external light (that is, sunlight) transmitted through the electronic shutter16are directed to the eyes of the passenger. As a result, the passenger recognizes the display light as a virtual image displayed and overlaid on the external landscape. The windshield25and the electronic shutter16function as projection target members on which display light is projected. Various types of information include road information, safety information, navigation information, vehicle information, entertainment information such as movies, and the like.

The WSD17is configured so that the transmittance of external light can be changed by providing the windshield25with an electronic shutter16. The visibility of the external landscape and the visibility of the display light by the passenger vary depending on the transmittance of the external light.

When the transmittance of the electronic shutter16is increased, the amount of external light transmitted through the windshield25increases, and the amount of display light reflected by the windshield25decreases. Therefore, the visibility of the external landscape is high, and the visibility of the display light is low. When the transmittance of the electronic shutter16is set to 100%, the passenger cannot see the display light.

When the transmittance of the electronic shutter16is decreased, the amount of external light transmitted through the windshield25decreases, and the amount of display light reflected by the windshield25increases. Therefore, the visibility of the external landscape is low, and the visibility of the display light is high. When the transmittance of the electronic shutter16is set to the lowest value (specifically, a value close to 0%), the external light transmitted through the windshield25is almost eliminated. As a result, the inside of the vehicle compartment becomes dark, and the passenger visually recognizes the display light projected on the windshield25. That is, by making the transmittance of the electronic shutter16close to 0, the inside of the vehicle compartment can be darkened and the windshield25can be used as a screen.

Further, the electronic shutter16can adjust the transmittance for each film member. Therefore, it is not necessary to adjust the entire windshield25to the same transmittance, and the windshield25can be divided into a plurality of regions and the transmittance can be adjusted for each of the plurality of regions. Therefore, it is possible to reduce the transmittance in the region where the external light reaches the eyes of some of the passengers among the plurality of passengers, and not to change the transmittance in the other regions.

The illuminator18is mounted in the center and above the vehicle width direction, for example, inside the front windshield25. The illuminator18includes a plurality of light emitting members such as LEDs, and when the selected light emitting member among the plurality of light emitting members is turned on, the face of the selected passenger among the plurality of passengers is irradiated with light.

The ECU10includes a CPU10a, a ROM10b, a RAM10c, an I/O, and the like, and the CPU10aexecutes various programs stored in the ROM10bto provide the functions of a transmittance control unit, a biometric information acquisition unit, a drowsiness determination unit, and an awakening determination unit, an external information acquisition unit, a lighting control unit, and an image display unit.

The ECU10determines the state of each passenger using the acquired biometric information. Then, the ECU10controls the transmittance of the WSD17(that is, the transmittance of the electronic shutter16) according to the determined state of each passenger to establish a vehicle compartment environment suitable for the state of each passenger. Here, three modes are defined as the passenger's state: a sleep onset mode in which the passenger falls asleep, a sleep mode in which the passenger is in a sleep state, and an awakening mode in which the passenger is awakened. Further, the awakening mode includes a normal awakening mode and an emergency awakening mode for awakening in an emergency. Further, the ECU10has a function of Artificial Intelligence, learns the usage pattern of the passenger compartment for each passenger, and constructs a more suitable passenger compartment environment for each passenger. In this embodiment, the ECU10corresponds to a vehicle display control device.

<2. Vehicle Compartment Environment Control Processing>

Next, the vehicle compartment environment control process executed by the ECU10will be described with reference to the flowcharts ofFIGS. 3 to 9.

First, in S10, the facial expression, body temperature, and heartbeat of each passenger are acquired, and it is determined whether or not the drowsiness of each passenger is detected based on the acquired facial expression, body temperature, and heartbeat of each passenger. When it is determined in S10that the drowsiness of each passenger has not been detected, the process proceeds to the process of S20, and when it is determined that the drowsiness of each passenger has been detected, the process proceeds to the process of S50.

In S20, it is determined whether or not any of the passengers has instructed the ECU10to fall asleep mode to put the passenger to sleep. The sleep onset mode may be instructed by any means such as switch input, touch panel input, and voice input. When it is determined in S20that the sleep onset mode has been instructed, the process proceeds to S50, and when it is determined that the sleep onset mode has not been instructed, the process proceeds to S30.

In S30, it is determined whether or not to recommend a nap to each passenger based on the schedule after each passenger gets off the vehicle. The schedule after each passenger gets off the vehicle may be input by each passenger, or the ECU10may be linked with the smartphone of each passenger so that the ECU10may automatically acquire the schedule from the smartphone. Further, the schedule after getting off of each passenger may be acquired from the result that the AI function of the ECU10has learned from the past behavior of each passenger.

The ECU10recommends a nap when each passenger performs a high-load work such as a long time business meeting after getting off the vehicle, and does not recommend a nap when resting at home. When it is determined in S30that nap is recommended, the process proceeds to S50, and when it is determined that nap is not recommended, the process proceeds to S40.

In S40, the normal mode is turned on. Specifically, the transmittance of the WSD is set to the standard transmittance so that the passenger can recognize the display light displayed and superimposed on the external landscape.

On the other hand, in S50, it is determined whether or not it is possible to safely take a nap to the set destination. Specifically, road information, weather information, and the like are acquired by wireless communication with the information center, and it is determined whether or not the vehicle can travel to the destination by level4automatic driving. In S50, when it is determined that the nap cannot be safely performed, the process proceeds to S40, and when it is determined that the nap can be safely performed, the process proceeds to S60.

In S60, the sleep onset mode is turned on and the flowchart shown inFIG. 4is executed. First, in S200, it is determined whether or not the passenger who is to fall asleep is a part of the passengers. In S200, when it is determined that all the passengers are to fall asleep, the process proceeds to S210, and when it is determined that some passengers are to fall asleep, the process proceeds to S220.

In S210, the sleep onset process shown in the flowchart ofFIG. 5is executed in the entire area of the WSD17, that is, the entire windshield25. Specifically, in S500, the transmittance is lowered in the entire region of WSD17. As a result, less outside light enters the vehicle compartment and the vehicle compartment becomes dark. In the sleep onset mode, the transmittance of the WSD17is lowered to reduce the external light that reaches the passenger's eyes and encourage the passenger to fall asleep.

On the other hand, in S220, the sleep onset process shown in the flowchart ofFIG. 5is executed in a part of the WSD17. Specifically, in S500, the transmittance of a part of the WSD17is lowered. A part of the WSD17is a part of the WSD17corresponding to a sleeping passenger, and is a part where the outside light reaches the passenger's eyes. This reduces the external light that reaches the eyes of the passengers who is to fall asleep, but does not reduce the external light that reaches the eyes of other passengers.

Returning to the flowchart ofFIG. 3, in S70, the facial expression, body temperature, and heartbeat of each passenger are acquired, and it is determined whether it can be confirmed that the passenger who has entered the sleep onset mode has slept based on the acquired facial expression, body temperature, and heartbeat of each passenger. When it is determined in S70that the sleep of the passenger has not been confirmed, the process proceeds to S80, and when it is determined that the sleep of the passenger has been confirmed, the process proceeds to S100.

In S80, the transmittance of WSD17is adjusted in order to encourage the passenger who has entered the sleep onset mode but has not slept. Specifically, a plurality of regions are set in the WSD17(that is, the windshield25), and the transmittance is changed with time for each of the set plurality of regions. For example, as shown inFIG. 10, a plurality of regions divided in the vehicle width direction are set in the WSD17, and the transmittances of the adjacent regions are set to different transmittances. As shown inFIG. 10, at one point in time, the transmittances of the six regions are set to low, medium, high, low, medium, and high, and at the next time point, the transmittances of the six regions are set to medium, high, low, medium, high, and low. In this way, the transmittance of each region is adjusted so that regions having different transmittances appear to move in the vehicle width direction. Alternatively, in order to encourage the passenger who has entered the sleep onset mode to sleep, an image that induces drowsiness is displayed on the WSD17that has become a screen with the transmittance of the WSD17set to the minimum value.

Subsequently, in S90, as in S70, it is determined whether or not it is determined whether it is conformed that the passenger has slept. When it is determined in S90that the sleep of the passenger has not been confirmed, it gives up to make the passenger to sleep, and the process proceeds to S40, and it turns on the normal mode. On the other hand, when it is determined in S90that the sleep of the passenger has been confirmed, the process proceeds to S100.

In S100, the sleep mode is turned on and the flowchart shown inFIG. 4is executed. First, in S200, it is determined whether or not the sleeping passengers are a part of the passengers. In S200, when it is determined that all the passengers are sleeping, the process proceeds to S210, and when it is determined that some passengers are sleeping, the process proceeds to S220.

In S210, the sleep process shown in the flowchart ofFIG. 6is executed in the entire area of the WSD17(that is, the windshield25). Specifically, in S600, the transmittance is lowered in the entire region of WSD17as compared with the sleep onset mode. That is, in the sleep mode, the passenger compartment is darker than in the sleep onset mode so that the passenger can get a comfortable sleep.

On the other hand, in S220, the sleep process shown in the flowchart ofFIG. 6is executed in a part of the WSD17(that is, the windshield25). Specifically, in S600, the transmittance of the region of the WSD17corresponding to the sleeping passenger is lowered as compared with the sleep onset mode. As a result, the external light that reaches the eyes of the sleeping passenger is further reduced as compared with the sleep mode, but the external light that reaches the eyes of other passengers is not reduced.

Subsequently, the processes of S110to S140and the process of S150are executed in parallel. In S110, the facial expression, body temperature, and heartbeat of each passenger are acquired, and the sleep state of the passenger who has entered the sleep mode is confirmed based on the acquired facial expression, body temperature, and heartbeat of each passenger.

Subsequently, in S120, it is determined whether or not the sleeping passenger has taken a sufficient nap. For example, when a deep sleep is taken for a period of about 15 minutes, it is determined that a sufficient nap has been taken. When it is determined in S120that a sufficient nap has not been taken, the process proceeds to S130, and when it is determined that a sufficient nap has been taken, the process proceeds to S140.

In S130, it is determined whether or not a nap can be safely taken to the destination. When it is determined in S130that a nap can be taken, the process returns to S110, and when it is determined in S130that the nap cannot be taken, the process proceeds to S140.

In S140, the normal awakening mode is turned on and the flowchart shown inFIG. 4is executed. When a passenger sleeps for too long, the passenger may not be able to return to driving immediately after waking up. Therefore, when the passenger can take a sufficient nap, the passenger is awakened. First, in S200, it is determined whether or not the passengers to be awakened are a part of the passengers. In S200, when it is determined to awaken all the passengers, the process proceeds to S210, and when it is determined to awaken some passengers, the process proceeds to S220.

In S210, the awakening process shown in the flowchart ofFIG. 7is executed in the entire area of the WSD17(that is, the windshield25). Specifically, in S300, the entire illuminator18is turned on to irradiate the faces of all the passengers with light.

Subsequently, in S310, the transmittance is increased to the standard transmittance in the entire region of the WSD17. That is, the sleep mode is shifted to the normal mode. In this case, the transmittance may be gradually increased, or the transmittance may be increased to the standard transmittance at once. This increases the amount of outside light that reaches each passenger's eyes.

On the other hand, in S220, the awakening process shown in the flowchart ofFIG. 7is executed in a part of the WSD17(that is, the windshield25). Specifically, in S300, the region of the irradiator18corresponding to the awakening passenger, that is, the light emitting member corresponding to the awakening passenger is turned on, and the light is irradiated toward the face of the awakening passenger. No light is applied to the faces of passengers who are not awakened.

Subsequently, in S310, the transmittance of the region of the WSD17corresponding to the awakening passenger is increased to the standard transmittance. The transmittance of the region of WSD17corresponding to the unawakened passenger is not changed.

When the passenger other than the driver is awake and the driver is sleeping, a system may notify the passenger other than the driver that the driver needs to be awakened to wake up the driver by the passenger other than the driver. In this case, instead of irradiating the light with the illuminator18, a passenger other than the driver is asked to wake up the driver, and the transmittance of the WSD17is increased. The notification to the passengers other than the driver may be notified by voice, or may be displayed and notified by the WSD17.

Here, in S210and S220, the flowchart shown inFIG. 8may be executed instead of the flowchart shown inFIG. 7.

First, in S700, the illuminance information is acquired and it is determined whether it is daytime or nighttime, that is, whether or not there is sunlight, according to whether or not the illuminance is larger than the first threshold value. In S700, when it is determined that the illuminance is equal to or higher than the first threshold value, the process proceeds to S710, and when it is determined that the illuminance is less than the first threshold value, the process proceeds to S730.

In S710, all or part of the illuminator18is turned on to irradiate all or part of the passenger's face with light.

Subsequently, in S720, the transmittance of all or part of the WSD17is increased to increase the light that reaches the eyes of all or part of the passengers. When the illuminance is equal to or higher than the first threshold value, the light of the illuminator18is weaker than the outside light, so the passenger can be comfortably awakened by controlling the light of the illuminator18to reach the passenger's eyes first.

On the other hand, in S730, the transmittance of all or part of the WSD17is increased to increase the light that reaches the eyes of all or part of the passengers.

Subsequently, in S740, all or part of the illuminator18is turned on to irradiate all or part of the passenger's face with light. When the illuminance is less than the first threshold value, the light of the illuminator18is stronger than the outside light, so the passenger can be comfortably awakened by controlling the outside light to reach the passenger's eyes first.

Returning to the flowchart ofFIG. 3, in S150, it is determined whether or not there is a need for an emergency stop. Specifically, using the detection information from the peripheral monitoring sensor11, it is determined whether or not the distance to the obstacle in front of the vehicle approaches the threshold value at which the emergency brake is activated. Alternatively, it is determined whether or not an emergency brake signal has been output. When it is determined in S150that there is no need for an emergency stop, the process of S150is repeatedly executed. When it is determined in S150that an emergency stop is necessary, the process proceeds to S160.

In S160, the emergency awakening mode is turned on, and the emergency awakening process shown in the flowchart ofFIG. 9is executed. Specifically, in S400, the entire illuminator18(that is, all light emitting members) is turned on to irradiate light, and at the same time, the transmittance of the entire region of WSD17is increased to 100% at once. As a result, the inside of the vehicle compartment becomes bright at once. That is, in the event of an emergency of the autonomous driving vehicle200, priority is given to promptly awakening the passenger rather than comfortably awakening the passenger. This is the end of this process.

According to the first embodiment described above, the following effects can be exhibited.

(1) The transmittance of WSD17is reduced in order to promote the sleep of the passengers. By reducing the transmittance of the WSD17, the incident of sunlight into the vehicle compartment is suppressed. Therefore, the passenger can fall asleep quickly and take a nap in the passenger compartment.

(2) The transmittance of WSD is increased in order to promote the awakening of the passengers. Increasing the transmittance of WSD increases the incidence of sunlight into the vehicle compartment. As a result, the passenger can be awakened.

(3) The passenger's biometric information is detected, and the detected biometric information is used to determine whether or not the passenger is in a state of drowsiness. Then, when it is determined that the passenger is in a state of drowsiness, the transmittance of WSD17is lowered. Therefore, when the passenger is drowsy, it is possible to automatically construct a vehicle compartment environment in which it is easy for the passenger to fall asleep.

(4) Using biometric information, it is determined whether or not the passenger is in a state of awakening. When it is determined that the passenger is awakened, the transmittance of WSD17is increased. Therefore, when the passenger is in a state where he/she should be awakened, it is possible to automatically construct a vehicle compartment environment in which the passenger is likely to be awakened. In addition, it is possible to suppress the occurrence of a situation in which the driver sleeps too much and cannot return to driving.

(5) When it is determined that the passenger is to be awakened, the transmittance of the WSD17is increased after the light of the illuminator18is irradiated. As a result, the burden on the passenger can be suppressed and the passenger can be awakened comfortably.

(6) When there is sunlight irradiation, the transmittance of WSD17is increased after irradiating the light of the illuminator18which is weaker than the outside light. On the other hand, when there is no irradiation of sunlight, the light of the illuminator18stronger than the outside light is irradiated after the transmittance of the WSD17is increased. As a result, the burden on the passenger can be suppressed according to the external environment, and the passenger can be comfortably awakened.

(7) In an emergency, the transmittance of WSD17can be increased to 100% at once at the same time as the light of the illuminator18irradiates. As a result, the interior of the vehicle compartment becomes bright at once, so that the passengers can be awakened quickly.

(8) By controlling the transmittance of the region of WSD17corresponding to each passenger, it is possible to promote sleep or awakening for each passenger.

As a result, it does not cause discomfort to passengers who do not need to promote sleep or awakening.

(9) By irradiating the light of the illuminator18for each passenger, there is no discomfort to the occupant who does not need to be awakened.

(10) By changing the transmittance with time for each of the plurality of regions set in WSD17, it is possible to encourage the passenger to sleep. In particular, when a heavy load is scheduled after the passenger gets off the vehicle, the passenger can be encouraged to sleep and the passenger can effectively take a nap.

(11) By lowering the transmittance of WSD17to the minimum value, switching the WSD17to be a screen, and displaying an image that induces drowsiness, it is possible to encourage the passenger to sleep.

Second Embodiment

1. Difference from First Embodiment

Since basic configuration of a second embodiment is the same as that of the first embodiment, the description of the common configuration will not be made, and the description will be made on the differences. The same reference numerals as in the first embodiment denote the same components, and reference is made to the preceding description.

In the first embodiment described above, in the awakening process, the transmittance of the region of the WSD17corresponding to the passenger to be awakened is increased to the standard transmittance. On the other hand, the second embodiment differs from the first embodiment in that, as shown inFIG. 11, in the awakening process, the transmittance of the eye-corresponding region40of the WSD17is fixed at a value at which the illuminance required for awakening can be obtained, and the regions of the WSD17other than the eye-corresponding region40of the WSD17is increased to the standard transmittance. The eye-corresponding region40corresponds to the awakening passenger's eye region30in the WSD17(i.e., the windshield25).

In this embodiment, the biometric information includes the passenger's eye area30. The ECU10acquires the eye region30from the face image taken by the DSM14. In the present embodiment, the DSM14corresponds to the observation device, and the face image corresponds to the observation information.

2. Awakening Process

Next, in the present embodiment, the awakening process executed by the ECU10will be described. In the present embodiment, the ECU10executes the same processing as in the first embodiment except for the processing of S140in the vehicle compartment environment control process.

In this embodiment, the ECU10executes the flowchart shown inFIG. 4when the normal awakening mode is turned on in S140. Then, in S210and S220, the awakening process shown inFIG. 12is executed.

First, in S800, the transmittance of WSD17is gradually increased.

Subsequently, in S810, the illuminance information is acquired, and it is determined whether or not the illuminance at the position of the passengers face to be awakened, that is, the illuminance in the vehicle compartment is equal to or higher than the second threshold value. The second threshold is larger than the first threshold and smaller than the reference value. The second threshold is the illuminance required for the awakening of the passenger, for example, 2500 lx. When it is determined in S810that the illuminance in the vehicle compartment is equal to or higher than the second threshold value, the process proceeds to S820, and when it is determined that the illuminance in the vehicle compartment is less than the second threshold value, the process returns to S800.

In S820, the eye region30is acquired from the facial image of the passenger to be awakened, the transmittance of the eye-corresponding region40of the WSD17(that is, the windshield25) corresponding to the eye region30is fixed, and the transmittance is not increased from that value. That is, when the transmittance of the eye-corresponding region40of the WSD17reaches the second threshold value, the transmittance is fixed. The eye-corresponding region40is the incident range of the external light in the WSD17, and corresponds to the incident range of the external light reaching the passenger's eye region30. Further, in S820, as shown inFIG. 11, the transmittance of the region other than the eye-corresponding region40in WSD17is increased to the reference value.

In this way, by suppressing the illuminance of the external light that reaches the passenger's eye region30to the minimum level at which the illuminance required for awakening can be obtained, it is possible to prevent the passenger's eye region30from suddenly brightening. As a result, it is possible to prevent the passenger from being dazzled by the sudden change in brightness. When it is necessary to switch the driving to the passenger after the passenger is awakened, the transmittance of the eye-corresponding region40of the WSD17may be gradually increased from a fixed value to a reference value. Further, when it is not necessary to switch the driving to the passenger after the passenger is awakened, the transmittance of the eye-corresponding region40of the WSD17may be maintained at a fixed value.

Here, in S210and S220, the flowchart shown inFIG. 13may be executed instead of the flowchart shown inFIG. 12.

First, in S900to S920, the same processing as in S700to S720of the flowchart shown inFIG. 8is executed.

Subsequently, in S930, the illuminance information is acquired, and it is determined whether or not the illuminance at the position of the passengers face to be awakened, that is, the illuminance in the vehicle compartment is equal to or higher than the second threshold value. The illuminance in the vehicle compartment here corresponds to the combined illuminance of both the external light incident from the WSD17and the irradiation light emitted from the illuminator18.

When it is determined in S930that the illuminance in the vehicle compartment is equal to or higher than the second threshold value, the process proceeds to S940, and when it is determined that the illuminance in the vehicle compartment is less than the second threshold value, the process returns to S920.

In S940, the same processing as in S820of the flowchart shown inFIG. 12is executed. As a result, the total illuminance of the outside light incident on the vehicle compartment from the WSD17and the irradiation light of the illuminator18is suppressed to the minimum necessary for awakening the passenger.

Further, in S950and S960, the same processing as in S730and S740in the flowchart shown inFIG. 8is executed. That is, in the flowchart shown inFIG. 13, a combination of the flowchart shown inFIG. 8and the flowchart shown inFIG. 12is executed.

According to the second embodiment described above, the following effects are provided in addition to the effects (1) to (4) and (6) to (11) of the first embodiment described above.

(12) When the passenger is awake, the illuminance of the light reaching the passenger's eye area30is suppressed to the minimum necessary for the passenger's awakening, so that it is suppressed for the passenger to feel a sudden change in brightness and to be dazzled.

Other Embodiments

Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments but various modifications can be made.

(A) In the above embodiment, the illuminance amount information detected by the illuminance sensor15is used to determine whether it is daytime or nighttime, alternatively, the present disclosure may not be limited to this. For example, the ECU10may determine from the date and the current time whether it is daytime or nighttime, that is, whether or not there is sunlight. Alternatively, the ECU10may acquire the illuminance amount information by wireless communication with the information center or the roadside unit.

(B) The vehicle display control device and the technique according to the present disclosure may be achieved by a dedicated computer provided by constituting a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the vehicle display control device and the technique according to the present disclosure may be achieved by a dedicated computer provided by constituting a processor with one or more dedicated hardware logic circuits. Alternatively, the vehicle display control device and the technique according to the present disclosure may be achieved using one or more dedicated computers constituted by a combination of the processor and the memory programmed to execute one or more functions and the processor with one or more hardware logic circuits. The computer program may also be stored on a computer readable non-transitory tangible recording medium as computer executable instructions. The technique for realizing the functions of the respective units included in the vehicle display control device does not necessarily need to include software, and all of the functions may be realized with the use of one or multiple hardware.

(C) The multiple functions of one component in the above embodiments may be realized by multiple components, or a function of one component may be realized by multiple components. Further, multiple functions of multiple elements may be implemented by one element, or one function implemented by multiple elements may be implemented by one element. In addition, a part of the configuration of the above embodiment may be omitted. Further, at least part of the configuration of the above-described embodiment may be added to or replaced with the configuration of another embodiment described above.

(D) In addition to the vehicle display control device described above, the present disclosure may be realized by various features such as a system having the vehicle display control device as a component, a program for operating a computer as the vehicle display control device, a non-transitory tangible storage medium such as a semiconductor memory storing this program, a display control method for a vehicle and the like.

The controllers and methods described in the present disclosure may be implemented by a special purpose computer created by configuring a memory and a processor programmed to execute one or more particular functions embodied in computer programs. Alternatively, the controllers and methods described in the present disclosure may be implemented by a special purpose computer created by configuring a processor provided by one or more special purpose hardware logic circuits. Alternatively, the controllers and methods described in the present disclosure may be implemented by one or more special purpose computers created by configuring a combination of a memory and a processor programmed to execute one or more particular functions and a processor provided by one or more hardware logic circuits. The computer programs may be stored, as instructions being executed by a computer, in a tangible non-transitory computer-readable medium.