JP2018090219A - Vehicle display control device and vehicle display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle display control device which suppresses both of flicker of a display image and contrast defect of the display image to the outside landscape.SOLUTION: A vehicle display control device controls virtual image display luminance of a display image to average corresponding luminance La corresponding to average illumination Ea until the time change rate ΔE of the present illumination Ep deviates to the illumination increase side from an allowable range ΔErh, controls the virtual image display luminance of the display image to present corresponding luminance Lp corresponding to the higher present illumination Ep in a case where the present illumination Ep is higher in comparison to the average illumination Ea when the time change rate ΔE deviates to the illumination increase side from the allowable range ΔErh, and controls the virtual image display luminance of the display image to the average corresponding luminance La corresponding to the higher average illumination Ea in a case where the average illumination Ea is higher in comparison to the present illumination Ep even when the time change rate ΔE deviates to the illumination increase side from the allowable range ΔErh.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle display control device and a vehicle display system including the same.

  Conventionally, in a vehicle equipped with a head-up display (hereinafter referred to as HUD) that projects a display image onto a projection member that transmits the scenery of the outside world, a technique for controlling the virtual image display of the display image by the projection is as follows: Widely known.

  As a technique for controlling the virtual image display in such a vehicle, the technique disclosed in Patent Document 1 uses a display image so as to correspond to the current illuminance acquired by the optical sensor as the ambient illuminance of the vehicle according to the brightness of the outside world. Controls the virtual image display brightness.

JP-A-9-54276

  Now, in the external environment of the vehicle during traveling, the ambient illuminance changes from moment to moment due to the direction of sunlight, the position of a shield that blocks sunlight, and the like. Therefore, the virtual image display brightness corresponds to the current illuminance acquired as ambient illuminance as it is, and if it changes from moment to moment, the display image may flicker, which may cause discomfort to the vehicle occupant.

  In order to solve such a problem, the present inventor suppresses flickering of the display image by calculating the average illuminance by averaging the current illuminance for each set time and calculating the average illuminance. We focused on what we can do. However, if the virtual image display brightness is made to correspond to the average illuminance, then if the ambient illuminance changes suddenly, it becomes difficult to follow the virtual image display brightness to the sudden change. There was a risk of a drop in visibility.

  Therefore, the present inventor, for example, when the ambient illuminance changes suddenly with the escape of the vehicle from the tunnel or the like, that is, when the temporal change rate of the current illuminance acquired every set time as the ambient illuminance becomes excessive. Research has been conducted on the technology for switching the virtual image display luminance from the luminance corresponding to the average illuminance to the luminance corresponding to the current illuminance. As a result, the contrast of the display image is ensured in a sudden change scene in which the ambient illuminance changes greatly from a small change state due to, for example, the vehicle leaving from a long tunnel, but it is difficult to secure in another scene. The problem became clear. The new problem will be described below.

  For example, when the ambient illuminance that has once shifted from the ascending side to the descending side as shown in FIG. 14 suddenly changes to the ascending side as shown in FIG. In V), with the return (timing W in FIG. 14), the luminance corresponding to the average illuminance Ea is switched to the luminance corresponding to the current illuminance Ep. At this time, when the current illuminance Ep is lower than the average illuminance Ea, the brightness corresponding to the average illuminance Ea is rapidly reduced to the brightness corresponding to the current illuminance Ep, thereby causing a contrast defect of the display image with respect to the outside scene. There is a risk of inviting the passenger to feel a drop in visibility.

  As described above, an object of the present invention is to provide a vehicle display control device that suppresses both flickering of the display image and contrast failure of the display image with respect to the outside scene, and a vehicle that includes such a vehicle display control device. To provide a display system.

  The technical means of the invention for achieving the object will be described below. The reference numerals in parentheses described in the claims and in this section disclosing the technical means of the invention indicate the correspondence with the specific means described in the embodiment described in detail later. It is not intended to limit the technical scope of the invention.

The first invention disclosed in order to solve the above-mentioned problem is
In the vehicle (2) equipped with the HUD (50) for projecting the display image (56) onto the projection member (21) that transmits the outside landscape (8), the vehicle display for controlling the virtual image display of the display image by the projection. A control device (54) comprising:
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the outside world as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S109) that calculates a time average value of the current illuminance acquired by the illuminance acquisition block as an average illuminance (Ea);
Until the temporal change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErh) to the illuminance increase side, the average corresponding luminance (La) corresponding to the average illuminance calculated by the average calculation block is obtained. A first control block (S106) for controlling the virtual image display brightness of the display image;
When the time change rate deviates from the allowable range to the illuminance increase side, if the current illuminance acquired by the illuminance acquisition block is higher than the average illuminance calculated by the average calculation block, it corresponds to the high current illuminance. A second control block (S108) for controlling the virtual image display brightness of the display image to the current corresponding brightness (Lp);
Even if the rate of time change falls outside the allowable range, if the average illuminance calculated by the average calculation block is higher than the current illuminance acquired by the illuminance acquisition block, it corresponds to the high average illuminance. And a third control block (S110) for controlling the virtual image display brightness of the display image.

In addition, the second invention disclosed in order to solve the above-described problem is
A HUD (50) that projects a display image (56) onto a projection member (21) that passes through an external landscape (8) in the vehicle (2);
A vehicle display system (1) including a vehicle display control device (54) for controlling a virtual image display of a display image by projection from a HUD onto a projection member,
The vehicle display control device
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the outside world as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S109) that calculates a time average value of the current illuminance acquired by the illuminance acquisition block as an average illuminance (Ea);
Until the temporal change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErh) to the illuminance increase side, the average corresponding luminance (La) corresponding to the average illuminance calculated by the average calculation block is obtained. A first control block (S106) for controlling the virtual image display brightness of the display image;
When the time change rate deviates from the allowable range to the illuminance increase side, if the current illuminance acquired by the illuminance acquisition block is higher than the average illuminance calculated by the average calculation block, it corresponds to the high current illuminance. A second control block (S108) for controlling the virtual image display brightness of the display image to the current corresponding brightness (Lp);
Even if the rate of time change falls outside the allowable range, if the average illuminance calculated by the average calculation block is higher than the current illuminance acquired by the illuminance acquisition block, it corresponds to the high average illuminance. And a third control block (S110) for controlling the virtual image display brightness of the display image.

  According to these first and second inventions, the virtual image display luminance of the display image is controlled to the average corresponding luminance corresponding to the average illuminance until the temporal change rate of the current illuminance deviates from the allowable range to the illuminance increasing side. As a result, while the current illuminance does not suddenly change to the rising side, the virtual image display luminance is made to correspond to the average illuminance, so that the display image is difficult to flicker.

  On the other hand, in the first and second inventions, when the current illuminance temporal change rate deviates from the allowable range to the illuminance increase side, if the current illuminance is higher than the average illuminance, the current correspondence corresponding to the higher current illuminance The virtual image display brightness of the display image is controlled by the brightness. As a result, when the average illuminance exceeds the average illuminance due to the sudden change of the current illuminance to the rising side, the virtual image display luminance is made to correspond to the current illuminance with a high average illuminance excess. It's hard to run out.

  Moreover, in the first and second inventions, if the average illuminance is higher than the current illuminance, even if the current illuminance temporal change rate is outside the allowable range, the average correspondence corresponding to the high average illuminance The virtual image display brightness of the display image is controlled by the brightness. As a result, when the current illuminance suddenly changes to the rising side and becomes less than the average illuminance, the virtual image display luminance is made to correspond to the high average illuminance instead of the low current illuminance below the average illuminance. The contrast of the display image with the landscape is unlikely to be insufficient.

  Therefore, according to the first and second inventions described above, it is possible to suppress both the flicker suppression of the display image and the contrast defect of the display image with respect to the outside scene.

The third invention disclosed in order to solve the above-described problem is
In the vehicle (2) equipped with the HUD (50) for projecting the display image (56) onto the projection member (21) that transmits the outside landscape (8), the vehicle display for controlling the virtual image display of the display image by the projection. A control device (54) comprising:
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the outside world as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S2109) for calculating a time average value of current illuminance acquired by the illuminance acquisition block as average illuminance (Ea);
Until the temporal change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErl) to the illuminance lowering side, the average corresponding luminance (La) corresponding to the average illuminance calculated by the average calculation block is obtained. A first control block (S2106) for controlling the virtual image display brightness of the display image;
When the time change rate deviates from the allowable range to the illuminance lowering side, when the current illuminance acquired by the illuminance acquisition block is lower than the average illuminance calculated by the average calculation block, it corresponds to the low current illuminance. A second control block (S2108) for controlling the virtual image display brightness of the display image to the current corresponding brightness (Lp);
Even if the time change rate falls outside the allowable range on the illuminance lowering side, if the average illuminance calculated by the average calculation block is lower than the current illuminance acquired by the illuminance acquisition block, it corresponds to the low average illuminance And a third control block (S2110) for controlling the virtual image display brightness of the display image.

The fourth invention disclosed in order to solve the above-described problem is
A HUD (50) that projects a display image (56) onto a projection member (21) that passes through an external landscape (8) in the vehicle (2);
A vehicle display system (1) including a vehicle display control device (54) for controlling a virtual image display of a display image by projection from a HUD onto a projection member,
The vehicle display control device
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the outside world as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S2109) for calculating a time average value of current illuminance acquired by the illuminance acquisition block as average illuminance (Ea);
Until the temporal change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErl) to the illuminance lowering side, the average corresponding luminance (La) corresponding to the average illuminance calculated by the average calculation block is obtained. A first control block (S2106) for controlling the virtual image display brightness of the display image;
When the time change rate deviates from the allowable range to the illuminance lowering side, when the current illuminance acquired by the illuminance acquisition block is lower than the average illuminance calculated by the average calculation block, it corresponds to the low current illuminance. A second control block (S2108) for controlling the virtual image display brightness of the display image to the current corresponding brightness (Lp);
Even if the time change rate falls outside the allowable range on the illuminance lowering side, if the average illuminance calculated by the average calculation block is lower than the current illuminance acquired by the illuminance acquisition block, it corresponds to the low average illuminance And a third control block (S2110) for controlling the virtual image display brightness of the display image.

  According to the third and fourth inventions, the virtual image display luminance of the display image is controlled to the average corresponding luminance corresponding to the average illuminance until the time change rate of the current illuminance deviates from the allowable range to the illuminance lowering side. As a result, while the current illuminance does not suddenly change to the decreasing side, the virtual image display luminance is made to correspond to the average illuminance, so that the display image hardly flickers.

  On the other hand, in the third and fourth inventions, if the current illuminance temporal change rate deviates from the allowable range to the illuminance lowering side, if the current illuminance is lower than the average illuminance, the current correspondence corresponding to the lower current illuminance The virtual image display brightness of the display image is controlled by the brightness. As a result, when the current illuminance suddenly changes to the lower side and becomes less than the average illuminance, the virtual image display luminance is made to correspond to the current illuminance lower than the average illuminance, so the contrast of the display image with respect to the outside scene It is hard to become excessive.

  Moreover, in the third and fourth inventions, if the average illuminance is lower than the current illuminance, even if the temporal change rate of the current illuminance is outside the allowable range, the average correspondence corresponding to the low average illuminance The virtual image display brightness of the display image is controlled by the brightness. As a result, if the average illuminance exceeds the current illuminance even if the current illuminance suddenly changes, the virtual image display luminance will correspond to the low average illuminance instead of the current illuminance that is higher than the average illuminance. The contrast of the display image with respect to is not likely to be excessive.

  Therefore, according to the third and fourth inventions described above, it is possible to suppress the flicker suppression of the display image and the contrast defect of the display image with respect to the outside scene at the same time.

It is an interior view which shows the vehicle interior of the own vehicle carrying the display system for vehicles by a first embodiment. It is a block diagram which shows the display system for vehicles by 1st embodiment. It is a block diagram which shows the structure of HUD by 1st embodiment. It is a flowchart which shows the display control flow by 1st embodiment. It is a time chart for demonstrating the effect by 1st embodiment. It is a time chart for demonstrating the effect by 1st embodiment. It is a flowchart which shows the display control flow by 2nd embodiment. It is a time chart for demonstrating the effect by 2nd embodiment. It is a time chart for demonstrating the effect by 2nd embodiment. It is a flowchart which shows the modification of FIG. It is a flowchart which shows the modification of FIG. It is a flowchart which shows the modification of FIG. It is a flowchart which shows the modification of FIG. It is a time chart for demonstrating the subject solved by this invention.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description may be abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other part of the configuration. Moreover, not only the combination of the configurations explicitly described in the description of each embodiment, but also the configuration of a plurality of embodiments can be partially combined even if they are not explicitly described, as long as there is no problem in the combination.

(First embodiment)
The vehicle display system 1 according to the first embodiment of the present invention is mounted on a vehicle 2 as shown in FIG. 1, and controls a virtual image display of a display image 56 that is visually recognized by an occupant from inside a passenger compartment 2 a of the vehicle 2.

  As shown in FIG. 2, the vehicle display system 1 includes a periphery monitoring system 3, a vehicle control system 4, and a display system 5. These systems 3, 4, and 5 are connected to each other via an in-vehicle network 6 such as a LAN (Local Area Network).

  The periphery monitoring system 3 includes an external sensor 30 and a periphery monitoring ECU (Electronic Control Unit) 31. The outside sensor 30 is a vehicle, an artificial structure, an obstacle such as a human being and an animal, and a traffic sign such as a speed sign and various warning signs present in the outside of the vehicle 2. Detect. The external sensor 30 is, for example, one type or plural types of sonar, radar, LIDAR (Light Detection and Ranging / Laser Imaging Detection and Ranging), and a camera.

  The periphery monitoring ECU 31 is mainly configured by a microcomputer having a processor and a memory, and is connected to the external sensor 30 and the in-vehicle network 6. The periphery monitoring ECU 31 acquires, for example, obstacle information, traffic sign information, and the like based on the output signal of the external sensor 30.

  The vehicle control system 4 includes a vehicle-related sensor 40, an occupant-related sensor 41, and a vehicle control ECU 42. The vehicle-related sensor 40 is connected to the in-vehicle network 6. The vehicle-related sensor 40 acquires, for example, driving state information, navigation information, traffic sign information, traveling environment information, and the like of the vehicle 2. The vehicle-related sensors 40 are a plurality of types including at least the illuminance sensor 40a among, for example, an illuminance sensor 40a, a vehicle speed sensor, a rotation speed sensor, a rudder angle sensor, a fuel sensor, a water temperature sensor, and a communication device.

  Here, the illuminance sensor 40a is composed of, for example, a phototransistor or a photodiode, and is installed on the room mirror 23 (see, for example, FIGS. 1 and 3) or the instrument panel 22 (not shown). The illuminance sensor 40a detects ambient illuminance corresponding to the brightness of the outside world by setting a predetermined area located in front of the passenger compartment 2a in the outside world of the vehicle 2 as a detection area.

  The occupant related sensor 41 shown in FIG. 2 is connected to the in-vehicle network 6. The occupant-related sensor 41 detects the state or operation of an occupant who has boarded in the passenger compartment 2a of the vehicle 2. The occupant-related sensor 41 is one or a plurality of types including at least the power switch 41a among, for example, a power switch 41a, a display setting switch, an occupant state monitor, a turn switch, and an automatic control switch. Here, the power switch 41a detects the operation by being operated by an occupant inside and outside the vehicle compartment 2a in order to start the internal combustion engine or the motor generator of the vehicle 2. For example, as the power switch 41a, one type or a plurality of types are adopted among a rotation operation type and a push operation type by an occupant, a remote operation type by an electronic key, and the like.

  The vehicle control ECU 42 is configured mainly by a microcomputer having a processor and a memory, and is connected to the in-vehicle network 6. The vehicle control ECU 42 is one type or a plurality of types among an engine control ECU, a motor control ECU, a brake control ECU, a steering control ECU, an integrated control ECU, and the like.

  As shown in FIGS. 1 to 3, the display system 5 is mounted on the vehicle 2 for visually presenting information. The display system 5 includes a HUD 50 and a HCU (HMI (Human Machine Interface) Control Unit) 54.

  As shown in FIGS. 1 and 3, the HUD 50 is installed on the instrument panel 22 in the passenger compartment 2a. The HUD 50 forms a display image 56 representing predetermined information by, for example, a liquid crystal type or scanning type projector 50a. The display image 56 is, for example, driving state information such as vehicle speed information and engine speed information, navigation information such as route guidance information and traffic jam information, traffic sign information such as speed sign information, and traveling environment information such as weather information and road surface information. Of these, one type or a plurality of types are represented. In addition to these pieces of information, the display image 56 may represent, for example, music information, video information, mobile communication information, and the like provided in the passenger compartment 2a.

  The HUD 50 projects the display image 56 formed in this way onto the front windshield 21 as a “projection member” through an optical system 50 b such as a concave mirror. Here, the front windshield 21 is formed of translucent glass, and thus transmits the outside scenery 8 as a scenery existing in front of the passenger compartment 2a in the outside of the vehicle 2 as shown in FIG. At this time, the luminous flux of the display image 56 reflected by the front windshield 21 and the luminous flux from the external scene 8 transmitted through the shield 21 are perceived by the passenger on the driver's seat 20 in the passenger compartment 2a as shown in FIG. Is done. As a result, the virtual image of the display image 56 formed in front of the front windshield 21 is displayed so as to be superimposed on a part of the external scene 8 as shown in FIG. It becomes possible. A virtual image display can also be realized by projecting the display image 56 onto the combiner using a translucent combiner that is disposed on the instrument panel 22 and transmits the outside scenery 8 in cooperation with the front windshield 21. It becomes.

  As described above, the virtual image display brightness of the display image 56 can be adjusted in whole or in part by setting, for example, the gradation value of each color in the projector 50a or the light emission brightness of the light source in the projector 50a. . Further, the virtual image display color and the virtual image display size of the display image 56 can be adjusted in whole or in part by setting the gradation value of each color in the projector 50a, for example.

  As shown in FIGS. 2 and 3, the HUD 50 has a built-in illuminance sensor 50c. The illuminance sensor 50c is composed of, for example, a phototransistor or a photodiode. The illuminance sensor 50c detects ambient illuminance corresponding to the brightness of the outside world by setting a predetermined area located in front of the passenger compartment 2a in the outside world of the vehicle 2 as a detection area.

  As shown in FIG. 2, the HCU 54 is mainly composed of a microcomputer having a processor 54 a and a memory 54 b, and is connected to the HUD 50 and the in-vehicle network 6. The HCU 54 controls the virtual image display of the display image 56 by the HUD 50. At this time, the HCU 54 executes display control based on information acquired or detected by the ECUs 31 and 42 and the sensors 40 and 41, information stored in the memory 54b, and the like. Note that the memory 54b of the HCU 54 and the memories of other various ECUs are respectively configured by using one or a plurality of storage media such as a semiconductor memory, a magnetic medium, or an optical medium.

  Here, the HCU 54 of the first embodiment functions as a “vehicle display control device” so as to read the display image 56 stored in the memory 54 b in advance and display the virtual image on the HUD 50. Specifically, the HCU 54 functionally realizes each step of the display control flow shown in FIG. 4 by executing the display control program stored in the memory 54b in advance by the processor 54a. This display control flow starts in response to an ON operation of the power switch 41a and ends in response to an OFF operation of the switch 41a. Here, in the first embodiment, when the power switch 41a is turned off, all values stored in the memory 54b of the current illuminance Ep, which will be described later, are reset (that is, initialization is performed so that the number of stored current illuminance Ep is zero). As described above, the reset process is executed.

  Note that “S” in the display control flow means each step. Further, the luminance control in the predetermined step of the display control flow will be described on the assumption that the virtual image display luminance of the display image 56 in which the virtual image display color and the virtual image display size are appropriately set is adjusted as a whole. Further, the display image 56 controlled by the virtual image display in the display control flow may be realized by the memory built in the HUD 50 or another display element of the display system 5, or by the cooperation of the built-in memory and the memory 54b. Good.

  As shown in FIG. 4, S101 of the display control flow is executed every set time ΔT such as 0.1 seconds. In S101, the ambient illuminance of the vehicle 2 detected by the illuminance sensors 40a and 50c is acquired as the current illuminance Ep for each set time ΔT based on the output signals of the sensors 40a and 50c. At this time, for example, an average value of the detected values is acquired as the current illuminance Ep in consideration of the balance of the detected values by the illuminance sensors 40a and 50c. The current illuminance Ep acquired in this way is temporarily stored in the memory 54b until it is reset.

  Here, in S101 of the first embodiment, the memory 54b stores the current illuminance Ep acquired every time S101 is executed from the last reset process by the power switch 41a off operation or S109 described later. At this time, as long as the current number of stored illuminance Ep stored from the previous reset process does not exceed the upper limit number (for example, 200), every time S101 is executed until the next reset process in S109 is executed. All acquired current illuminance Ep is stored. However, if the number of current illuminance Ep stored exceeds the upper limit, the oldest current illuminance Ep to be reset is replaced every time S101 is executed until the next reset process is executed by executing S109. , The latest acquired current illuminance Ep is stored.

  In subsequent S102, it is determined whether or not the number of executions of S101 has reached a plurality of times from the ON operation of the power switch 41a (that is, the start of the display control flow). As a result, if a negative determination is made, the process returns to S101 after securing a delay time for securing the set time ΔT. On the other hand, if a positive determination is made, the process proceeds to S103.

  In S103, every time execution of S101, the plurality of current illuminance Ep stored in the memory 54b is time-averaged, and the value of the time average is calculated as the average illuminance Ea. At this time, a plurality of stored values equal to or less than the upper limit number acquired by the latest S101 and the previous S101 and stored in the memory 54b are adopted as the current illuminance Ep to be time-averaged.

  In the subsequent S104, a time change rate ΔE (see, for example, FIGS. 5 and 6) is calculated with respect to the current illuminance Ep acquired in the latest S101 and stored in the memory 54b. At this time, by dividing (ie, dividing) the difference value (here, absolute value) between the pair of current illuminances Ep acquired in S101 immediately before and immediately before by the set time ΔT, the time change rate ΔE is obtained. Calculated.

  Further, in S105, it is determined whether or not the time change rate ΔE calculated in S104 is out of the allowable range ΔErh on the illuminance increase side (see, for example, FIGS. 5 and 6). Here, the threshold value ΔEth that determines the allowable range ΔErh on the illuminance increasing side is the minimum value (for example, 2600 Lx) of the time change rate ΔE on the illuminance increasing side that is assumed to cause a significant decrease in the visibility of the display image 56. Defined in Therefore, under such a definition, the allowable range ΔErh is set to a range of the time change rate ΔE that is greater than or equal to zero and less than the threshold value ΔEth on the illuminance increasing side.

  If the negative change determination is made in S105 because the time change rate ΔE toward the illuminance increase side is less than the threshold ΔEth and within the allowable range ΔErh, the process proceeds to S106. Further, since the time change rate ΔE is a value on the illuminance lowering side, the process proceeds to S106 even when a negative determination is made in S105. Therefore, in the first embodiment, the process proceeds to S106 until the time change rate ΔE deviates from the allowable range ΔErh to the illuminance increase side.

  In S106, the virtual image display luminance of the display image 56 is controlled to the average corresponding luminance La corresponding to the average illuminance Ea calculated in the latest S103. Here, the correspondence relationship between the average illuminance Ea and the average corresponding luminance La is stored in advance in the memory 54b as one type or a combination of a plurality of types of tables, maps, relational expressions, and the like. Therefore, by converting the average illuminance Ea into the average corresponding luminance La based on the correspondence relationship stored in the memory 54b, the virtual image display luminance to be controlled is adjusted to the average corresponding luminance La after the conversion. At this time, in S106, the control is continued for the control continuation time for securing the set time ΔT, and then the process returns to S101. From the above, while the time change rate ΔE falls within the allowable range ΔErh on the illuminance increase side or is a value on the illuminance decrease side, that is, until the time change rate ΔE deviates from the allowable range ΔErh to the illuminance increase side. The 56 virtual image display luminances are continuously controlled to the average corresponding luminance La.

  On the other hand, if the time change rate ΔE toward the illuminance increasing side is equal to or greater than the threshold value ΔEth and the time change rate ΔE is out of the allowable range ΔErh, if the determination in S105 is affirmative, the process proceeds to S107. In S107, it is determined whether or not the current illuminance Ep calculated in the latest S101 is higher than the average illuminance Ea calculated in the latest S103.

  Since the current illuminance Ep is higher than the average illuminance Ea, if an affirmative determination is made in S107, the process proceeds to S108. In S108, the virtual image display luminance of the display image 56 is controlled to the current corresponding luminance Lp corresponding to the current illuminance Ep calculated in the latest S101. Here, the correspondence relationship between the current illuminance Ep and the current corresponding luminance Lp is stored in the memory 54b in advance, for example, in one or a plurality of combinations among tables, maps, relational expressions, and the like. Therefore, by converting the current illuminance Ep into the current corresponding luminance Lp based on the correspondence relationship stored in the memory 54b, the virtual image display luminance to be controlled is adjusted to the current corresponding luminance Lp after the conversion. At this time, in S108, the control is continued for a control continuation time for securing the set time ΔT together with S109 described later, and then the process proceeds to S109 before returning to S101. As described above, when the temporal change rate ΔE deviates from the allowable range ΔErh to the illuminance increase side, when the current illuminance Ep is higher than the average illuminance Ea, the virtual image display luminance is changed from the average corresponding luminance La to the current corresponding luminance. Switching to Lp is controlled.

  In S109, the reset processing of the memory 54b is executed except for the latest current illuminance Ep calculated in the latest S101. That is, as a result of the execution of S109, only the latest current illuminance Ep calculated in the latest S101 is left as the stored value of the memory 54a that can be used after the execution. At this time, in S109, the reset process is executed for the process continuation time for securing the set time ΔT in combination with S108 described above, and then the process returns to S101. Therefore, in S101 returned from S109, the current illuminance Ep calculated in the previous S101 is reset, and the calculation of the average illuminance Ea is started from the current illuminance Ep calculated in the previous S101. That is, after the control at S108, the current illuminance Ep before the control at S108 is omitted, and the calculation of the average illuminance Ea is started from the current illuminance Ep at the control at S108.

  On the other hand, if the average illuminance Ea is higher than the current illuminance Ep, or the current illuminance Ep and the average illuminance Ea are substantially equal, a negative determination is made in S107, S110 Migrate to In S110, the virtual image display luminance of the display image 56 is controlled to the average corresponding luminance La corresponding to the average illuminance Ea calculated in the latest S103. At this time, in S110, the control is continued for the control continuation time for securing the set time ΔT, and then the process returns to S101. From the above, even if the time change rate ΔE deviates from the allowable range ΔErh to the illuminance increasing side, if the average illuminance Ea is higher than or substantially coincides with the current illuminance Ep, the virtual image display luminance corresponds to the average. The maintenance control or the return control from the current corresponding brightness Lp to the average corresponding brightness La is performed with the brightness La maintained.

  In the first embodiment described above, the functional part that executes S101 in the HCU 54 corresponds to an “illuminance acquisition block”, and the functional part that executes S103 and S109 in the HCU 54 corresponds to an “average calculation block”. To do. In the first embodiment, the functional part that executes S106 in the HCU 54 corresponds to a “first control block”, and the functional part that executes S108 in the HCU 54 corresponds to a “second control block”. Among these, the functional part that executes S110 corresponds to a “third control block”.

  According to the first embodiment described so far, until the time change rate ΔE of the current illuminance Ep deviates from the allowable range ΔErh to the illuminance increase side (period Xh in FIGS. 5 and 6), the average correspondence corresponding to the average illuminance Ea. The virtual image display brightness of the display image 56 is controlled to the brightness La. As a result, while the current illuminance Ep does not suddenly change to the rising side (period Xh in FIGS. 5 and 6), the virtual image display luminance is made to correspond to the average illuminance Ea, so that the display image 56 is difficult to flicker.

  On the other hand, in the first embodiment, if the time change rate ΔE of the current illuminance Ep deviates from the allowable range ΔErh to the illuminance increase side, the current illuminance Ep is higher than the average illuminance Ea (timing Yh in FIG. 5). The virtual image display luminance of the display image 56 is controlled to the current corresponding luminance Lp corresponding to the high current illuminance Ep. Accordingly, when the average illuminance Ep exceeds the average illuminance Ea due to the sudden change of the current illuminance Ep to the increasing side (timing Yh in FIG. 5), the virtual image display luminance is made to correspond to the current illuminance Ep having a high excess of the average illuminance Ea. Therefore, the contrast of the display image 56 with respect to the external scenery 8 is unlikely to be insufficient. This can be exhibited as an operational effect, for example, when the vehicle escapes from the inside of the tunnel to the outside of the bright tunnel.

  Moreover, in the first embodiment, when the average illuminance Ea is higher than the current illuminance Ep (timing Zh in FIG. 6) even if the temporal change rate ΔE of the current illuminance Ep deviates from the allowable range ΔErh to the illuminance increase side. The virtual image display luminance of the display image 56 is controlled to the average corresponding luminance La corresponding to the high average illuminance Ea. As a result, when the current illuminance Ep suddenly changes to the rising side and becomes less than the average illuminance Ea (timing Zh in FIG. 6), the current illuminance Ep is not the low current illuminance Ep less than the average illuminance Ea but the high average illuminance Ea. Since the virtual image display brightness is made to correspond, the contrast of the display image 56 with respect to the external scenery 8 is unlikely to be insufficient. This can be exhibited as an operational effect, for example, when the vehicle passes through a dark part that is shaded under an elevated road and returns to the sun.

  Therefore, according to the first embodiment described above, it is possible to suppress both the flicker suppression of the display image 56 and the contrast defect (for example, difficulty in visual recognition) of the display image 56 with respect to the external scenery 8.

  In addition, according to the first embodiment, after the control to the current corresponding luminance Lp, the current illuminance Ep before the control is omitted, and the calculation of the average illuminance Ea is started from the current illuminance Ep at the time of the control. According to this, the low current illuminance Ep before the time change rate ΔE outside the allowable range ΔErh that triggers the control to the current corresponding luminance Lp is not used for calculating the average illuminance Ea. Therefore, it can be suppressed that the average illuminance Ea is calculated to be low and the average corresponding luminance La remains low even though the current illuminance Ep is increased by the time change rate ΔE outside the allowable range ΔErh. Accordingly, it is possible to surely suppress the lack of contrast as a contrast defect of the display image 56 with respect to the outside scene 8.

(Second embodiment)
The second embodiment of the present invention is a modification of the first embodiment.

  In the display control flow of the second embodiment shown in FIG. 7, S101 to S104 are executed as in the first embodiment. Furthermore, in the display control flow of the second embodiment, S2105 to S2110 different from S105 to S110 of the first embodiment are executed.

  Specifically, in S2105 following S104, it is determined whether or not the time change rate ΔE calculated in S104 is out of the allowable range ΔErl (see, for example, FIGS. 8 and 9) on the illuminance reduction side. Here, the threshold value ΔEtl for determining the allowable range ΔErl on the illuminance lowering side is the minimum value (for example, 2600Lx) of the time change rate ΔE to the illuminance lowering side that is assumed to cause a significant decrease in the visibility of the display image 56. Defined in Therefore, under this definition, the allowable range ΔErl is set to a range of the time change rate ΔE that is greater than or equal to zero and less than the threshold value ΔEtl on the illuminance lowering side.

  If the negative change determination is made in S2105 because the time change rate ΔE toward the illuminance decrease side is less than the threshold ΔEtl and within the allowable range ΔErl, the process proceeds to S2106. Further, since the time change rate ΔE is a value on the illuminance increasing side, the process proceeds to S2106 even when a negative determination is made in S2105. Therefore, in the second embodiment, the process proceeds to S2106 until the time change rate ΔE deviates from the allowable range ΔErl to the illuminance lowering side.

  In S2106, the virtual image display luminance of the display image 56 is controlled to the average corresponding luminance La corresponding to the average illuminance Ea calculated in the latest S103. At this time, in S2106, the control is continued for the control continuation time for securing the set time ΔT, and then the process returns to S101. From the above, while the time change rate ΔE falls within the allowable range ΔErl on the illuminance decrease side or is a value on the illuminance increase side, that is, until the time change rate ΔE deviates from the allowable range ΔErl to the illuminance decrease side. The 56 virtual image display luminances are continuously controlled to the average corresponding luminance La.

  On the other hand, if the time change rate ΔE toward the illuminance decrease side is equal to or greater than the threshold value ΔEtl and the time change rate ΔE is out of the allowable range ΔErl, the process proceeds to S2107 if an affirmative determination is made in S2105. In S2107, it is determined whether or not the current illuminance Ep calculated in the latest S101 is lower than the average illuminance Ea calculated in the latest S103.

  Since the current illuminance Ep is lower than the average illuminance Ea, if an affirmative determination is made in S2107, the flow proceeds to S2108. In S2108, the virtual image display luminance of the display image 56 is controlled to the current corresponding luminance Lp corresponding to the current illuminance Ep calculated in the latest S101. At this time, in S2108, the control is continued for the control continuation time for securing the set time ΔT together with S2109 described later, and then the process proceeds to S2109 before returning to S101. As described above, when the time change rate ΔE deviates from the allowable range ΔErl to the illuminance lowering side, when the current illuminance Ep is lower than the average illuminance Ea, the virtual image display luminance is changed from the average corresponding luminance La to the current corresponding luminance. Switching to Lp is controlled.

  In S2109, the reset processing of the memory 54b is executed except for the latest current illuminance Ep calculated in the latest S101. That is, by the execution of S2109, only the latest current illuminance Ep calculated in the latest S101 is left as the stored value of the memory 54a that can be used after the execution. At this time, in S2109, the reset process is executed only for the process continuation time for securing the set time ΔT in combination with S2108 described above, and then the process returns to S101. Therefore, in S101 returned from S2109, the current illuminance Ep calculated in the previous S101 is reset, and the calculation of the average illuminance Ea is started from the current illuminance Ep calculated in the previous S101. That is, after the control in S2108, the current illuminance Ep before the control in S2108 is omitted, and the calculation of the average illuminance Ea is started from the current illuminance Ep in the control in S2108.

  On the other hand, if the average illuminance Ea is lower than the current illuminance Ep, or the current illuminance Ep and the average illuminance Ea are substantially equal, a negative determination is made in S2107, S2110 Migrate to In S2110, the virtual image display luminance of the display image 56 is controlled to the average corresponding luminance La corresponding to the average illuminance Ea calculated in the latest S103. At this time, in S2110, the control is continued for the control continuation time for securing the set time ΔT, and then the process returns to S101. From the above, even if the time change rate ΔE deviates from the allowable range ΔErl to the illuminance lowering side, if the average illuminance Ea is lower than or substantially coincides with the current illuminance Ep, the virtual image display luminance corresponds to the average. The maintenance control or the return control from the current corresponding brightness Lp to the average corresponding brightness La is performed with the brightness La maintained.

  In the second embodiment described above, the functional part that executes S101 in the HCU 54 corresponds to an “illuminance acquisition block”, and the functional part that executes S103 and S2109 in the HCU 54 corresponds to an “average calculation block”. To do. In the second embodiment, the functional part that executes S2106 in the HCU 54 corresponds to the “first control block”, and the functional part that executes S2108 in the HCU 54 corresponds to the “second control block”. Among these, the functional part that executes S2110 corresponds to a “third control block”.

  According to the second embodiment described so far, the average corresponding luminance corresponding to the average illuminance Ea until the time change rate ΔE of the current illuminance Ep deviates from the allowable range ΔErl to the illuminance lowering side (period Xl in FIGS. 8 and 9). In La, the virtual image display brightness of the display image 56 is controlled. As a result, while the current illuminance Ep does not suddenly change to the decreasing side (period Xl in FIGS. 8 and 9), the virtual image display luminance is made to correspond to the average illuminance Ea, and thus the display image 56 is difficult to flicker.

  On the other hand, in the second embodiment, when the temporal change rate ΔE of the current illuminance Ep deviates from the allowable range ΔErl to the illuminance lowering side, the current illuminance Ep is lower than the average illuminance Ea (timing Yl in FIG. 8). The virtual image display luminance of the display image 56 is controlled to the current corresponding luminance Lp corresponding to the low current illuminance Ep. Thereby, when the current illuminance Ep suddenly changes to the lower side and becomes less than the average illuminance Ea (timing Yl in FIG. 8), the virtual image display luminance is made to correspond to the low current illuminance Ep less than the average illuminance Ea. Therefore, the contrast of the display image 56 with respect to the external scenery 8 is unlikely to be excessive. This can be exhibited as an operational effect when, for example, the vehicle enters the dark tunnel from outside the tunnel.

  In addition, in the second embodiment, even when the temporal change rate ΔE of the current illuminance Ep deviates from the allowable range ΔErl to the illuminance lowering side, when the average illuminance Ea is lower than the current illuminance Ep (timing Zl in FIG. 9). The virtual image display luminance of the display image 56 is controlled to the average corresponding luminance La corresponding to the low average illuminance Ea. Thus, if the average illuminance Ea is exceeded even when the current illuminance Ep suddenly changes to the lower side (timing Zl in FIG. 9), the virtual image is not the current illuminance Ep that is higher than the average illuminance Ea but the low average illuminance Ea. Since the display brightness is made to correspond, the contrast of the display image 56 with respect to the external scenery 8 is unlikely to be excessive. This can be exhibited as an operational effect when, for example, the vehicle passes through a bright part that is exposed to sunlight during a short period of time, between tunnels or between buildings, and returns to the shade.

  Therefore, also by the second embodiment described above, it is possible to suppress the flicker suppression of the display image 56 and the contrast defect (for example, illusion etc.) of the display image 56 with respect to the outside scene 8 in a compatible manner.

  In addition, according to the second embodiment, after the control to the current corresponding luminance Lp, the current illuminance Ep before the control is omitted, and the calculation of the average illuminance Ea is started from the current illuminance Ep at the time of the control. According to this, the high current illuminance Ep before the time change rate ΔE outside the allowable range ΔErl that triggers the control to the current corresponding luminance Lp is not used for calculating the average illuminance Ea. Therefore, although the current illuminance Ep is decreased by the time change rate ΔE outside the allowable range ΔErl, it is possible to suppress the average illuminance Ea being calculated to be high and the average corresponding luminance La from being kept high. Therefore, it is possible to reliably suppress an excessive contrast as a contrast defect of the display image 56 with respect to the outside scene 8.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to these embodiments, and various embodiments and combinations can be made without departing from the scope of the present invention. Can be applied.

  In the first modification regarding the first embodiment, the threshold value ΔEth may be set to the maximum value among the time change rates ΔE toward the illuminance increase side on which the visibility of the display image 56 is assumed to be ensured. In the first modification, as shown in FIG. 10, the allowable range ΔErh of the time change rate ΔE is set to a range that is greater than or equal to zero and less than or equal to the threshold ΔEth on the illuminance increase side. As a result, in Modification 1 shown in FIG. 10, when the time change rate ΔE toward the illuminance increase side is equal to or smaller than the threshold value ΔEth and falls within the allowable range ΔErh, or when the time change rate ΔE becomes a value on the illuminance decrease side, The process proceeds to S106. On the other hand, in the first modification shown in FIG. 10, when the rate of time change ΔE toward the illuminance increase side exceeds the threshold ΔEth and deviates from the allowable range ΔErh, the process proceeds from S105 to S107.

  In the second modification related to the second embodiment, the threshold value ΔEtl may be set to the maximum value of the time change rate ΔE toward the illuminance reduction side where the visibility of the display image 56 is assumed to be ensured. In the second modification, as shown in FIG. 11, the allowable range ΔErl of the time change rate ΔE is set to a range that is not less than the zero value and not more than the threshold value ΔEtl on the illuminance lowering side. As a result, in the modified example 2 shown in FIG. 11, when the time change rate ΔE toward the illuminance decrease side is equal to or less than the threshold value ΔEtl and falls within the allowable range ΔErl, or when the time change rate ΔE becomes a value on the illuminance increase side, The process moves to S2106. On the other hand, in the second modification shown in FIG. 11, when the time change rate ΔE to the illuminance lowering side exceeds the threshold ΔEtl and deviates from the allowable range ΔErl, the process proceeds from S2105 to S2107.

  In S107 of Modification 3 related to the first embodiment, as shown in FIG. 12, the current illuminance Ep calculated in the latest S101 is higher or substantially equal to the average illuminance Ea calculated in the latest S103. It is determined whether or not. That is, in S107 of Modification 3, it is determined whether or not the current illuminance Ep is equal to or greater than the average illuminance Ea. As a result, in the third modification shown in FIG. 12, when the current illuminance Ep is higher than the average illuminance Ea, or when the average illuminance Ea and the current illuminance Ep are substantially equal, the process proceeds from S107 to S108. Transition. On the other hand, in Modification 3 shown in FIG. 12, the process proceeds from S107 to S110 only when the average illuminance Ea is higher than the current illuminance Ep.

  In S2107 of Modification 4 related to the second embodiment, as shown in FIG. 13, the current illuminance Ep calculated in the latest S101 is lower or substantially equal to the average illuminance Ea calculated in the latest S103. It is determined whether or not. That is, in S2107 of Modification 4, it is determined whether or not the current illuminance Ep is equal to or less than the average illuminance Ea. As a result, in the modified example 4 shown in FIG. 13, when the current illuminance Ep is lower than the average illuminance Ea, or when the average illuminance Ea and the current illuminance Ep are substantially equal, the process proceeds from S2107 to S2108. Transition. On the other hand, in the modified example 4 shown in FIG. 13, the process proceeds from S2107 to S2110 only when the average illuminance Ea is lower than the current illuminance Ep.

  In the modification 5 regarding the first and second embodiments, one of the illuminance sensors 40a and 50c may not be provided. In this case, in S101 of the display control flow, the detected value of the one provided between the illuminance sensors 40a and 50c is acquired as the ambient illuminance.

  In the sixth modification related to the first and second embodiments, at least a part of the display control flow may be realized by hardware using one or a plurality of ICs instead of functionally realized by the HCU 54. Good. In the modified example 7 regarding the first and second embodiments, in addition to or instead of the HCU 54, one or more of the ECUs 31 and 42 that control other display elements of the display system 5 and the ECUs 31 and 42 are designated as “vehicle May be made to function as a “display control apparatus”.

DESCRIPTION OF SYMBOLS 1 Vehicle display system, 2 Vehicles, 5 Display systems, 8 Outside world scenery, 21 Front windshield, 40a Illuminance sensor, 50 HUD, 50c Illuminance sensor, 54 HCU, 56 Display image, E Ambient illumination a Average illumination, Ep Current illumination , La Average brightness, Lp Current brightness, ΔE time rate of change, ΔErh, ΔErl tolerance, ΔT set time

Claims (6)

In a vehicle (2) equipped with a head-up display (50) that projects a display image (56) onto a projection member (21) that passes through an external landscape (8), a virtual image display of the display image by the projection is controlled. A vehicle display control device (54) comprising:
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the external environment as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S109) for calculating a time average value of the current illuminance acquired by the illuminance acquisition block as average illuminance (Ea);
The average corresponding luminance corresponding to the average illuminance calculated by the average calculation block until the time change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErh) to the illuminance increase side. (La), a first control block (S106) for controlling the virtual image display brightness of the display image;
When the time change rate deviates from the allowable range to the illuminance increase side, when the current illuminance acquired by the illuminance acquisition block is higher than the average illuminance calculated by the average calculation block, A second control block (S108) for controlling the virtual image display luminance of the display image to the current corresponding luminance (Lp) corresponding to the high current illuminance;
When the average illuminance calculated by the average calculation block is higher than the current illuminance acquired by the illuminance acquisition block, even if the time change rate deviates from the allowable range to the illuminance increase side, A vehicle display control device comprising: a third control block (S110) that controls a virtual image display luminance of the display image to the average corresponding luminance corresponding to the high average illuminance. In a vehicle (2) equipped with a head-up display (50) that projects a display image (56) onto a projection member (21) that passes through an external landscape (8), a virtual image display of the display image by the projection is controlled. A vehicle display control device (54) comprising:
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the external environment as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S2109) for calculating the time average value of the current illuminance acquired by the illuminance acquisition block as average illuminance (Ea);
The average corresponding luminance corresponding to the average illuminance calculated by the average calculation block until the time change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErl) to the illuminance lowering side. (La), a first control block (S2106) for controlling the virtual image display luminance of the display image;
When the current change rate acquired by the illuminance acquisition block is lower than the average illuminance calculated by the average calculation block when the time change rate deviates from the allowable range to the illuminance reduction side, A second control block (S2108) for controlling the virtual image display brightness of the display image to the current corresponding brightness (Lp) corresponding to the low current illuminance;
Even if the time change rate falls outside the allowable range on the illuminance lowering side, when the average illuminance calculated by the average calculation block is lower than the current illuminance acquired by the illuminance acquisition block, A vehicle display control apparatus comprising: a third control block (S2110) for controlling a virtual image display brightness of the display image to the average corresponding brightness corresponding to the low average illuminance.   After the control by the second control block, the average calculation block (S103, S109, S2109) omits the current illuminance before the control by the second control block, and the current illuminance at the time of control by the second control block The vehicle display control apparatus according to claim 1, wherein the calculation of the average illuminance is started. A head-up display (50) that projects a display image (56) onto a projection member (21) that transmits the scenery (8) in the outside world in the vehicle (2);
A vehicle display control system (1) including a vehicle display control device (54) for controlling a virtual image display of the display image by projection from the head-up display onto the projection member,
The vehicle display control device comprises:
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the external environment as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S109) for calculating a time average value of the current illuminance acquired by the illuminance acquisition block as average illuminance (Ea);
A first control block (S106) for controlling the virtual image display brightness of the display image until the temporal change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErh) to the illuminance increase side. When,
When the time change rate deviates from the allowable range to the illuminance increase side, when the current illuminance acquired by the illuminance acquisition block is higher than the average illuminance calculated by the average calculation block, A second control block (S108) for controlling the virtual image display luminance of the display image to the current corresponding luminance (Lp) corresponding to the high current illuminance;
When the average illuminance calculated by the average calculation block is higher than the current illuminance acquired by the illuminance acquisition block, even if the time change rate deviates from the allowable range to the illuminance increase side, A vehicle display system comprising: a third control block (S110) that controls the virtual image display luminance of the display image to the average corresponding luminance corresponding to the high average illuminance. A head-up display (50) that projects a display image (56) onto a projection member (21) that transmits the scenery (8) in the outside world in the vehicle (2);
A vehicle display control system (1) including a vehicle display control device (54) for controlling a virtual image display of the display image by projection from the head-up display onto the projection member,
The vehicle display control device comprises:
An illuminance acquisition block (S101) for acquiring the ambient illuminance of the vehicle according to the brightness of the external environment as the current illuminance (Ep) for each set time (ΔT);
An average calculation block (S103, S2109) for calculating the time average value of the current illuminance acquired by the illuminance acquisition block as average illuminance (Ea);
The average corresponding luminance corresponding to the average illuminance calculated by the average calculation block until the time change rate (ΔE) of the current illuminance acquired by the illuminance acquisition block deviates from the allowable range (ΔErl) to the illuminance lowering side. (La), a first control block (S2106) for controlling the virtual image display luminance of the display image;
When the current change rate acquired by the illuminance acquisition block is lower than the average illuminance calculated by the average calculation block when the time change rate deviates from the allowable range to the illuminance reduction side, A second control block (S2108) for controlling the virtual image display brightness of the display image to the current corresponding brightness (Lp) corresponding to the low current illuminance;
Even if the time change rate falls outside the allowable range on the illuminance lowering side, when the average illuminance calculated by the average calculation block is lower than the current illuminance acquired by the illuminance acquisition block, A vehicle display system comprising: a third control block (S2110) for controlling a virtual image display luminance of the display image to the average corresponding luminance corresponding to the low average illuminance.   After the control by the second control block, the average calculation block (S103, S109, S2109) omits the current illuminance before the control by the second control block, and the current illuminance at the time of control by the second control block The vehicle display system according to claim 1, wherein the calculation of the average illuminance is started.

Images