JP2023020243A - Display device for vehicles - Google Patents

Abstract

To realize a display device for vehicles with which, while responding to a display body and the solar radiation state of occupants in display control by a self-luminous display body, it is possible to both improve visibility and suppress an increase in power consumption.SOLUTION: This display device for vehicles comprises a solar radiation estimation unit 12, an illuminance acquisition unit 13, an occupant information acquisition unit 14, and a display control unit 15. The display control unit 15 changes the display size and/or the display luminance of the content displayed on a display body, on the basis of the solar radiation region of a display body 4 that is estimated by the solar radiation estimation unit 12, the environment illuminance of the display body 4 that is acquired by the illuminance acquisition unit 13 and the solar radiation state of occupants that is acquired by the occupant information acquisition unit 14.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicular display device that executes luminance control in a self-luminous display mounted in a vehicle such as an automobile.

2. Description of the Related Art Conventionally, as this type of vehicle display device, for example, the one described in Patent Document 1 has been proposed. The vehicular display device described in Patent Document 1 calculates the luminance distribution of light in front of the driver based on the image captured by the vehicle-mounted camera, and calculates the illuminance distribution on the self-luminous display from the illuminance signal from the illuminance sensor. Then, based on these calculated data, the luminance control of the display is executed. As a result, when the display is exposed to sunlight, the vehicle display device controls the brightness of the portion of the display image that is exposed to sunlight so that the passenger can visually recognize it, thereby improving visibility. while suppressing an increase in power consumption.

JP 2020-47433 A

The vehicular display device captures an image in front of the occupant with an in-vehicle camera arranged at a position different from the viewpoint of the occupant, and calculates the brightness distribution of light in front of the occupant based on the obtained image data. Therefore, the calculated luminance distribution may not match the actual luminance distribution at the passenger's viewpoint, and the visibility of the displayed image may not be improved. In addition, this vehicular display device cannot perform brightness control in consideration of the solar radiation condition of the occupant, such as when the occupant's eyes are exposed to sunlight.

In view of the above points, the present invention executes display control in consideration of the solar radiation conditions of the occupant when sunlight or reflection occurs on the display surface of a self-luminous display body, thereby improving the visibility of the display screen. It is an object of the present invention to provide a display device for a vehicle that simultaneously suppresses an increase in power consumption.

In order to achieve the above object, a vehicle display device according to claim 1 is a vehicle display device that is mounted on a vehicle and executes luminance control of a self-luminous display body (4), A solar radiation estimating unit (12) for estimating a solar radiation area on a display surface (4a) on which an image is displayed, and an illuminance acquisition unit for acquiring illuminance information of an environment in which a display object is placed from an in-vehicle device (20) mounted on a vehicle. an occupant information acquiring unit (14) for acquiring information of a predetermined area including the eyes of the occupant from an occupant imaging unit (22) for imaging the occupant of the vehicle; a display control unit (15) that changes at least one of the display size and display brightness of content to be displayed on a display surface based on the illuminance information acquired by the acquisition unit and the occupant's eye information acquired by the occupant information acquisition unit; , has

In this vehicular display device, the solar radiation estimating section estimates the solar radiation area on the display surface of the display, the illuminance acquiring section acquires the environmental illumination, and the passenger information acquiring section acquires the solar radiation condition for the eyes of the passenger. In this vehicular display device, the display control unit performs control to change at least one of the display brightness and the display size of the content to be displayed on the display based on information on the solar radiation area and illuminance on the display surface and the eyes of the occupant. conduct. As a result, even when sunlight or reflection occurs on the display surface of the display, display control is executed in consideration of the solar radiation conditions of the occupant, ensuring visibility of the display surface and suppressing an increase in power consumption. becomes possible.

It should be noted that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence relationship between the component etc. and specific components etc. described in the embodiments described later.

1 is a block diagram showing a display system according to an embodiment; FIG. It is a block diagram which shows the structural example of a solar radiation estimation part. FIG. 4 is a diagram showing an example of a shadow area and a reflection area that appear on a display; It is a figure which shows an example of an isopower line based on display size and display brightness. It is a figure which shows an example of the isopower line for every solar radiation condition to a display body and a passenger|crew. It is a figure which shows an example of the visible map. 4 is a flow chart showing an example of processing in display control by the display system; It is a flowchart which shows an example of the discrimination|determination process of the solar radiation state with respect to a passenger|crew.

An embodiment of the present invention will be described below with reference to the drawings. In addition, in each of the following embodiments, portions that are the same or equivalent to each other will be described with the same reference numerals.

(embodiment)
A display system to which the vehicle display device according to the embodiment is applied will be described. This display system is preferably installed in a vehicle such as an automobile, for example, and configured as an in-vehicle display system that executes luminance control of the display 4, which will be described later.

In this specification, a case where the self-luminous display 4 is an OLED (organic light emitting diode) display will be described as a typical example. In this case, the display system of this embodiment may be called an "OLED display system," an "organic EL (electroluminescence) display system," an "EL display system," or the like.

The display system, for example, as shown in FIG. ing. Hereinafter, for convenience of explanation, the vehicle equipped with this display system will be referred to as "own vehicle".

The control unit 1 corresponds to a display device that controls image display by the display unit 4, and based on various signals such as detection signals from various sensors included in the vehicle-mounted device 2 and video signals from various devices. It controls image display on the display 4 . The control unit 1 is, for example, an electronic control unit in which a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), I/O (Input/Output), etc. are mounted on a circuit board (not shown). is. For example, the controller 1 and the display 4 are directly connected via a connection wiring, and the controller 1 and the in-vehicle device 2 are connected via the in-vehicle LAN 3 . As a result, various signals from the in-vehicle device 2 are input to the control unit 1 directly or through the in-vehicle LAN 3 . A detailed configuration of the control unit 1 will be described later.

The in-vehicle device 2 includes a device for inputting a video signal to the control unit 1, a device for inputting vehicle information to the control unit 1, and the like. Here, as the in-vehicle equipment 2, for example, an in-vehicle camera 21, an occupant imaging unit 22, an illuminance sensor 23, an attitude sensor 24, a navigation device 25, and a communication device 26 are mounted.

The configuration of the vehicle-mounted device 2 described above is merely an example, and the configuration may include devices other than the devices shown here. The in-vehicle device 2 may be configured to include, for example, multimedia, an air conditioner, a vehicle ECU (Electronic Control Unit), and other various in-vehicle devices.

The in-vehicle camera 21 is an arbitrary image pickup device that takes an image of a predetermined area including at least the display surface of the display body 4 of the own vehicle, and is mounted at an arbitrary position of the own vehicle. The in-vehicle camera 21 captures an image of the display surface of the display 4 and outputs the obtained image data to the control unit 1, for example. The image data obtained by the vehicle-mounted camera 21 is used for estimating the area on the display surface of the display 4 where sunlight or reflection occurs. Details of this will be described later.

In addition, the on-vehicle camera 21 may be mounted on the vehicle alone, or may be mounted in plurality. In the latter case, at least one of them is used for imaging the display surface of the display 4. The in-vehicle camera 21 may be used for other imaging such as the exterior of the own vehicle.

The occupant imaging unit 22 is an occupant of the vehicle and is an imaging device that captures an image of a predetermined area including the eyes of a person who sees the display 4. For example, the driver status monitor (registered trademark) manufactured by DENSO CORPORATION. be done. The object imaged by the occupant imaging unit 22 may be an occupant sitting in one of the seats of the own vehicle, may be the driver, or may be another occupant. Therefore, the mounting position of the occupant imaging section 22 can be appropriately changed according to the mounting position of the display body 4 . The occupant image capturing unit 22 captures, for example, a predetermined area including the eyes of the occupant to be imaged (for example, the entire face), and outputs the obtained image data to the control unit 1 . The image data obtained by the occupant imaging unit 22 is used to determine whether or not the occupant's eyes are exposed to sunlight. Details of this will be described later.

The illuminance sensor 23 is a sensor that detects the amount of solar radiation on the display 4 , and detects, for example, the amount of solar radiation for each partitioned area of the display 4 . For example, a plurality of illuminance sensors 23 are arranged around the display 4 in the vehicle interior of the vehicle. When a plurality of illuminance sensors 23 are mounted, the display area is partitioned into a plurality of areas, with the area for displaying images in the display body 4 as the display area, and the display area is associated with each partitioned area. . The illuminance sensor 23 detects the illuminance of the area to which the illuminance sensor 23 is assigned, which is a partitioned display area, and outputs a detection signal indicating the detection result to the control unit 1 directly or via the in-vehicle LAN 3. It is configured to

In addition, when a plurality of illuminance sensors 23 are arranged around the display body 4, the arrangement of the illuminance sensors 23 and the corresponding area in the display area are arbitrary. It may be changed as appropriate according to the size and the like.

The attitude sensor 24 is, for example, a gyro sensor, acquires the attitude of the own vehicle in which it is mounted, that is, the inclination (yaw, roll, pitch) of the own vehicle, and inputs the information to the control unit 1 . For example, the posture sensor 24 inputs to the control unit 1 information indicating the vehicle state, such as the inclination (that is, the inclination angle) of the vehicle due to a slope.

The navigation device 25 inputs to the control unit 1 a video signal indicating the current position of the vehicle and a map image based on the map information stored in the map database. In addition, the navigation device 25 inputs to the control unit 1, based on the user's operation, a video signal indicating, for example, a video for setting a destination, a video relating to information on facilities and shops in the vicinity of the vehicle or in the vicinity of the destination, and the like. . Furthermore, the navigation device 25 acquires information on the latitude, longitude, current time, and direction of the vehicle by using a known GPS (Global Positioning System), for example, and inputs this information to the control unit 1 .

The communication device 26 is, for example, a wireless LAN, acquires information on the altitude and direction of the sun through an external network such as the Internet, and inputs the information on the position of the sun to the control unit 1 . In addition to the position information of the sun, the communication device 26 may acquire various types of information such as weather and various types of data such as images, sounds, and videos, and input them to the control unit 1 .

In addition, various information such as the own vehicle, illuminance, occupants, and solar position are controlled via the in-vehicle LAN 3 from the in-vehicle camera 21, the occupant imaging unit 22, the illuminance sensor 23, the attitude sensor 24, the navigation device 25, the communication device 26, and the like. It is input to Part 1, but is not limited to this example. For example, a vehicle ECU may be included as the in-vehicle device 2, and part or all of the various information may be input to the control unit 1 via the vehicle ECU.

The in-vehicle LAN 3 is an in-vehicle network installed in the own vehicle on which the display system of the present embodiment is mounted, and enables transmission of various signals from the in-vehicle device 2 to the control unit 1 .

The display 4 is composed of a display having a plurality of pixels composed of self-luminous elements such as OLEDs, for example, and displays an image corresponding to the video output signal from the control section 1 . The display body 4 is configured such that the brightness level can be adjusted by applying a variable drive voltage to each self-luminous element constituting the display area for displaying an image, that is, to each pixel. The display body 4 may be one or more, and in the case of more than one, for example, in front of the driver's seat, in front of the passenger's seat, or in front of the driver's seat and the front passenger's seat. installed in any location different from

In this specification, since self-luminous displays such as OLED displays are well known, detailed description of the display itself is omitted. As the self-luminous element, an OLED will be described as a typical example, but the present invention is not limited to this, and other self-luminous elements such as an inorganic EL and a micro LED may be used.

The above is the basic configuration of the display system.

[Control part]
Next, details of the control unit 1 will be described with reference to FIGS. 1 to 3. FIG.

Hereinafter, for the sake of simplification of explanation, the area of the display surface of the display 4 that is exposed to sunlight is referred to as a "solar area", and the area that is not exposed to sunlight is referred to as a "non-solar area". Although FIG. 3 does not show a cross section, hatching is applied to facilitate understanding of a shadow region R1 and a reflection region R2, which will be described later.

For example, as shown in FIG. 1, the control unit 1 includes a database unit 11, a solar radiation estimation unit 12, an illuminance acquisition unit 13, an occupant information acquisition unit 14, a display control unit 15, and a video output unit 16. Various signals are input from the in-vehicle device 2 .

The database unit 11 stores, for example, execution programs for various processes performed by the solar radiation estimation unit 12, the illuminance acquisition unit 13, the display control unit 15, and data tables used in the programs. Various programs, data, and the like stored in the database unit 11 are read or executed during various processes in the solar radiation estimation unit 12, the illuminance acquisition unit 13, and the display control unit 15, for example. The database unit 11 stores at least a visible map used for control by the display control unit 15 . The visible map will be described later.

In addition to the database unit 11, the display system or the control unit 1 includes, for example, other memories (not shown) such as ROM and RAM for storing various programs executed by the control unit 1 and various data transmitted from the vehicle-mounted device 2. A configuration having a medium may also be used. In this case, for example, the display system is configured such that the control unit 1 has a storage medium different from the database unit 11, or has an external storage medium different from the control unit 1, and the control unit 1 has the storage medium Executes reading of various programs and writing of data from

The solar radiation estimator 12 acquires, for example, date and time information and vehicle information of the own vehicle from the vehicle-mounted device 2, estimates the solar radiation direction and the solar radiation area with respect to the display 4 based on these information, and controls the display of the estimation result. Output to unit 15 . For example, as shown in FIG. 2, the solar radiation estimation unit 12 includes a position acquisition unit 121 that acquires position information of the own vehicle based on the input vehicle information, and a display surface of the display unit 4 based on the input solar information. and a solar irradiation area calculation unit 122 for calculating the solar irradiation area in the .

For example, the position acquisition unit 121 receives attitude information about the inclination of the vehicle from the attitude sensor 24, and receives date and time information and position information about the latitude and longitude of the point where the vehicle is located from the navigation device 25. Acquire the location information of the own vehicle. "Vehicle information" in FIG. 2 refers to attitude information and position information of the own vehicle. The position acquisition unit 121 outputs the acquired position information of the host vehicle to the solar irradiation area calculation unit 122, for example.

For example, the solar radiation area calculation unit 122 calculates the amount of solar radiation from the sun to the vehicle based on the position information of the vehicle from the position acquisition unit 121 and the information on the altitude and direction of the sun (that is, solar information) from the communication device 26 . Calculate direction.

For example, the solar radiation area calculation unit 122 calculates, as the direction of solar radiation with respect to the vehicle, an altitude angle corresponding to the altitude direction of the sun with respect to the ground plane on which the vehicle is located, and when viewed from the normal direction to the ground plane. and the azimuth angle corresponding to the azimuth direction of the sun from the own vehicle at . Hereinafter, for the sake of simplification of explanation, the solar radiation direction of the vehicle will be referred to as "vehicle solar radiation direction". The altitude angle is, for example, the angle between a virtual straight line connecting the vehicle and the sun and the ground plane. The azimuth angle is, for example, an angle formed between a virtual straight line connecting the vehicle and the sun and the direction of travel when the vehicle is viewed from the top. The traveling direction of the own vehicle is a direction along the entire length of the own vehicle, and means a direction from the passenger compartment side to the windshield side. The altitude angle and azimuth angle can be obtained by a known method, for example, by designating the latitude of the location of the host vehicle and using the solar declination and the hour angle to calculate them using a spherical trigonometry formula.

The solar radiation area calculation unit 122 calculates the solar radiation direction of the sun with respect to the display surface, for example, based on the calculated vehicle solar radiation direction and display body information such as the mounting position of the display body 4 in the own vehicle and the orientation of the display surface. . Hereinafter, for the sake of simplification of explanation, the solar radiation direction with respect to the display surface will be referred to as "display surface solar radiation direction". The display surface solar radiation direction is, for example, the angle between the display surface of the display body 4 and the solar radiation direction, and the altitude and azimuth angles are calculated by the solar radiation area calculator 122 . The display information is stored in the database unit 11 in advance, for example, and is used to calculate the solar radiation area on the display 4 .

The insolation area calculator 122 calculates the insolation area on the display surface of the display 4 based on the calculated display surface insolation direction, for example. Specifically, for example, based on the 3D model of the own vehicle, the shape, size, mounting position, and orientation of the display surface 4, the display surface solar radiation direction is set using optical simulation software, and the display of the display unit 4 is performed. Calculate the distribution of the solar radiation area/non-solar radiation area on the surface. Hereinafter, for convenience of explanation, the distribution of the solar radiation area/non-solar radiation area on the display surface of the display 4 is simply referred to as "area distribution". Then, for example, a set value of the display surface solar radiation direction is changed, a database of area distribution for each display surface solar radiation direction is created in advance, and the database is stored in the database unit 11 . The insolation area calculation unit 122 selects, for example, one area distribution corresponding to the calculated display surface insolation direction from the database. The insolation area calculation unit 122 can estimate the insolation area on the display 4 by, for example, the method described above, and outputs the estimation result to the area information output unit 124 .

For example, as shown in FIG. 3, the shadow calculation unit 123 calculates the shadow area R1 and the reflection on the display surface 4a by a known image authentication technique based on the camera image obtained by capturing the display surface 4a of the display body 4 from the in-vehicle camera 21. Then, the embedded region R2 is calculated. The shadow area R1 is an area corresponding to the non-solar area. The reflection area R2 is an area in which the constituent members of the own vehicle (for example, the steering wheel, the ceiling of the vehicle interior, etc.) and the external scenery (for example, the sky, clouds, buildings, etc.) are reflected in the display surface 4a. is. The reflection area R2 can occur in both the area of the display surface 4a that is actually exposed to sunlight and the area that is not exposed to sunlight. It can also be said. The shadow calculation unit 123 outputs information of the calculated shadow region R1 and reflection region R2 to the region information output unit 124, for example.

The calculation result of the reflection region R2 by the shadow calculator 123 is used for display control using a visible map, which will be described later. Details of this will be described later.

For example, the area information output unit 124 adds the shadow area R1 and the shadow area R1 on the display surface 4a of the display 4 calculated by the shadow calculation unit 123 to the distribution of the solar area/non-solar area on the display 4 calculated by the solar area calculation unit 122. Correction processing is performed by adding the reflection region R2. For example, the area information output unit 124 corrects the non-solar area calculated by the solar area calculation unit 122 with the shadow area R1 calculated by the shadow calculation unit 123, and outputs the solar area calculated by the solar area calculation unit 122 to the shadow calculation unit. Correction is performed using the reflection area R2 calculated in 123 . Then, the area information output unit 124 outputs the corrected distribution of the solar radiation area/non-solar radiation area to the display control unit 15 as the solar radiation area information.

The illuminance acquisition unit 13 receives an output signal from the illuminance sensor 23 and acquires information of "environmental illuminance" which is the illuminance of the environment in which the display member 4 is installed. The illuminance acquisition unit 13, for example, acquires the environmental illuminance for each partitioned area of the display 4 from the plurality of illuminance sensors 23, calculates the illuminance distribution in the display area of the display 4, and uses the obtained illuminance distribution as illuminance information. Output to the display control unit 15 . The illuminance distribution can be calculated, for example, by arranging a plurality of illuminance sensors 23 along the upper and lower sides of the display surface 4a of the display body 4 and performing linear estimation from the illuminance data at each arrangement location.

The occupant information acquiring unit 14 acquires information on the solar radiation condition of the occupant's eyes based on the image data of the predetermined region including the occupant's eyes captured by the occupant imaging unit 22 . The occupant information acquisition unit 14 estimates the illuminance around the eyes of the occupant to be imaged by, for example, a known image authentication technique, and determines whether or not the subject is in a sunny state. For example, the occupant information acquisition unit 14 outputs the above determination result to the display control unit 15 as occupant information.

The non-sunlight condition, that is, the shade condition, also includes a condition in which sun visors, sunglasses, or the like shield the eyes of the occupant from sunlight.

The display control unit 15 controls, for example, at least one of the luminance and the display size of a pixel group positioned in a solar radiation area or a reflection area (hereinafter referred to as a “specific pixel group” for convenience) among the pixel groups constituting the display body 4. (hereinafter referred to as “display control” for convenience) is executed. The display control unit 15 executes display control of the specific pixel group based on, for example, the insolation area information from the insolation estimation unit 12, the illuminance distribution information from the illuminance acquisition unit 13, and the occupant information from the occupant information acquisition unit 14. do. This display control is performed using a visible map stored in the database unit 11, for example. Details of the visibility map are described in the next section. For example, the display control unit 15 outputs image data after performing display control on image data input to the control unit 1 from the in-vehicle device 2 to the video output unit 16 .

The video output unit 16 outputs a video output signal so that the display unit 4 displays the image data transmitted from the display control unit 15 after adjusting the luminance and/or the display size.

The above is the basic configuration of the control unit 1 .

The control unit 1 may be configured to receive a video signal from the vehicle-mounted device 2 and correct the video signal, or may generate a video signal based on the input signal from the vehicle-mounted device 2 and correct it. It may be configured to

[Isopower line]
Next, the iso-power line for ensuring visibility and suppressing the increase in power consumption will be described. Briefly describe the relationship.

Hereinafter, for the sake of simplification of explanation, a portion of the content displayed on the display 4 that displays predetermined information such as letters, numbers, symbols, figures, and images outside the vehicle will be referred to as an "information portion". The remaining portion different from is sometimes referred to as a “background portion”, respectively. Hereinafter, "display size" in this specification means the size of part or all of the information portion.

The visibility of the information portion of the display content improves as the display size increases. However, in the display content, the display brightness of the information portion is generally higher than that of the background portion. Therefore, although the visibility is improved by increasing the display size of the information portion, power consumption is also increased because the portion with high luminance is increased.

Further, when the display size of the information portion is the same, the visibility is improved when the display brightness is increased to the extent that the display is not dazzling. However, increasing the display luminance also increases the amount of current, resulting in an increase in power consumption.

Therefore, in order to ensure visibility and suppress an increase in power consumption, for example, when the display size of the information portion is increased, the display brightness is not increased, and when the display brightness is increased, the display size is increased. It is necessary to perform display control such as suppressing In other words, by controlling the display size and display brightness to keep the power consumption constant or within a predetermined range within the range where visibility can be secured, both ensuring visibility and suppressing an increase in power consumption are achieved. It can be said that it is possible.

The present inventors defined the relationship between the display brightness and the display size that keeps the power consumption constant as an equal power line, and devised a method of the present disclosure that performs display control based on the equal power line that takes visibility into consideration. Specifically, for example, as shown in FIG. 4, xy ² =a (a>0) where x is the display brightness of the information portion (eg, cd/m ² ) and y is the display size (eg, logMAR×10). Set up isopower lines that satisfy The power consumption is kept constant as long as the display size and display brightness are set on the isopower line.

Note that logMAR is logarithmic visual acuity, and is an index that does not depend on the distance between the occupant and the display. MAR is an abbreviation for Minimum Angle of Resolution. The display size unit is arbitrary and does not necessarily have to be logMAR. However, when setting the display size using a method other than logMAR, it is necessary to set a different numerical value for each position of the occupant using the display 4 or when placing multiple displays 4. Therefore, the display size is set using logMAR. preferably.

In addition, the display luminances x1 to x6 in FIG. 4 have a magnitude relationship of x1<x2<x3<x4<x5<x6, but each numerical value is arbitrary, and the visibility function described below is used. Appropriately set in the evaluation. This is the same for the display sizes "small", "medium" and "high" in FIG. In addition, in the example shown in FIG. 4, the display size is divided into three stages of "small", "medium", and "high", but the display size is not limited to this example, and may be two stages or less, or four stages or more. can be classified by Display brightness x1 to x6 and display size "small", "medium" and "high" in FIG. 6, which will be described later, correspond to those described above.

The value of a in the equipower line equation is, for example, an arbitrary numerical value greater than 0, and is appropriately set according to the visibility of the display size and display brightness. The visibility of the display size and display brightness is determined, for example, by human visual sensory evaluation. For example, a content having a display size and display brightness on the display 4 is displayed, and a plurality of people are allowed to visually recognize the content for a predetermined time (eg, 1.5 seconds) from a predetermined distance (eg, 1 m). Gradually evaluate the degree of Then, in order to reduce the influence of individual differences, the number of people who perform the sensory evaluation is increased as much as possible, and a database is created of display sizes evaluated as being visually recognizable by a large number of people and numerical values of display brightness at that time. The value of a in the equi-power line equation is set based on the result of judging that a large number of people (for example, 80% or more) can visually recognize the above-described visibility evaluation.

The relationship between display size and display brightness that can be visually recognized by a large number of people differs depending on the solar radiation condition on the display surface 4a, that is, whether it is a solar radiation area or a non-solar radiation area. Therefore, isopower lines are set corresponding to the case of a solar radiation area and the case of a non-solar radiation area, as shown in FIG. 4, for example. In the example shown in FIG. 4, corresponding to the non-solar area, the iso-power line represented by the formula xy ² =a (a>0) is called "iso-power line L1", and corresponding to the insolation area, xy ² =b ( The iso-power lines represented by the equations b>0, b>a) are denoted as "iso-power lines L2".

In the non-solar area, it means that the display size and the display brightness that satisfy xy ² ≧a, that is, the coordinates of the display size and the display brightness located on or above the isoelectric power line L1 are values that can ensure visibility. . In the insolation region, it means that the display size and the display brightness that satisfy xy ² ≧b, that is, the coordinates of the display size and the display brightness located on or above the isoelectric power line L2 are values that can ensure visibility. Conversely, the display size and the display brightness positioned below the iso-power lines L1 and L2 are numerical values in which power consumption is small but visibility cannot be ensured. From the viewpoint of suppressing power consumption, the coordinates of the display size and the display brightness are preferably closer to the iso-power line L1 in the non-solar area and to the iso-power line L2 in the insolation area.

The display size that can ensure visibility and the coordinates of the display brightness at that time are defined as "map values", and as shown in FIG. exist.

For example, in the non-solar area, when the display luminance is x3, all of the small, medium, and high display sizes are visible, and these map values are m11, m12, and m13, respectively. In the non-solar region, for example, when the display luminance is x2, medium and high display sizes are visible, and these map values are m14 and m15, respectively.

On the other hand, in the sunlight area, for example, when the display luminance is x6, all of the small, medium, and high display sizes are visible, and these map values are m21, m22, and m23, respectively. In the solar radiation area, for example, when the display brightness is x5, medium and high display sizes are visible, and these map values are m24 and m25, respectively.

In the example shown in FIG. 4, the map value m14 of the map values m11 to m15 is the closest to the constant power line L1, and the map value m24 of the map values m21 to m25 is the closest to the constant power line L2. Therefore, if you want to maximize the effect of suppressing the increase in power consumption while ensuring visibility, the display size/display brightness of the map value m14 is used for the non-solar area, and the display size/display brightness is the map value m24 for the solar area. Each display brightness may be controlled.

Note that the numerical values of the display size/display brightness and the number of map values in each state are arbitrary, and are not limited to the example shown in FIG. can be changed as appropriate.

The visibility of the displayed content is also affected by the presence or absence of reflections on the display surface 4 a of the display 4 and the solar radiation condition on the eyes of the passenger using the display 4 . Therefore, for each of these situations, it is necessary to set an equal power line that can ensure both visibility and reduction of power consumption.

Specifically, for example, as shown in FIG. 5, in states S1 to S4 depending on the presence or absence and degree of reflection on the display surface 4a and the presence or absence of solar radiation on the occupant's eyes, etc. Set power lines AD.

For example, "a situation in which there is no reflection on the display surface 4a and no solar radiation to the eyes of the occupant" is defined as "state S1", and "there is uniform reflection on the display surface 4a and the eyes of the occupant are not exposed to sunlight". A situation in which there is no solar radiation to "is assumed to be "state S2". In addition, "a situation in which there is a uniform reflection on the display surface 4a and there is sunlight on the eyes of the occupant" is defined as "state S3", and "a situation in which there is a complicated reflection on the display surface 4a and the occupant's eyes are A situation in which there is solar radiation on the eyes" is defined as "state S4". In the order of states S1, S2, S3, and S4, it becomes difficult for the occupant to see the displayed content, and the power consumption required to ensure visibility increases in this order. In order to ensure visibility and reduce power consumption in accordance with each state, states S1 to S4, the distribution of the solar radiation area/non-solar radiation area on the display surface 4a, and the environmental illuminance and so on, and refer to map values on or near the corresponding isopower lines. A "visible map" is used to control the display size and display brightness to ensure visibility and reduce power consumption, depending on the solar radiation conditions of the display 4, environmental illuminance, reflections, and solar radiation conditions on the occupants. be done.

Although not shown in FIG. 5 for the sake of clarity, each of the iso-power lines A to D also has a plurality of map values as described in FIG. In addition, "uniform reflection" means reflection of uniform scenery such as the sky, and "complex reflection" means reflection of complex scenery such as buildings and trees. means. Furthermore, the iso-power lines A to D are based on the visibility by human visual observation, for example, projection (reflection) of scenery on the display surface 4a and illuminating the eyes of a person who evaluates visibility with a light source such as a light ( Sunlight on the occupants), etc., can be created and created in the same manner as above.

[Visible map]
Next, the visible map will be described.

Hereinafter, for convenience of explanation, the state in which the eyes of the occupant using the display 4 are exposed to sunlight will be referred to as "sunlight state", and the state in which the eyes of the occupant are not exposed to sunlight will be referred to as "shade state".

Assuming each state such as the solar radiation condition of the display 4, the solar radiation condition of the occupant, the illuminance, and the mounting position of the display 4 in the own vehicle, the combination of the display size and the display luminance can ensure visibility in each of these conditions. A curve that keeps power consumption substantially constant is an isopower line. A data group consisting of a plurality of map values equal to or greater than the equipower line in each state is stored in, for example, the database unit 11 as a visible map.

For example, the visible map has an arbitrary data format such as a data table as shown in FIG. The visually recognizable map corresponds to each state such as the occupant's solar radiation condition (sunny/shade condition), the solar radiation condition of the display 4 (solar area/non-solar area), and the mounting position of the display 4, for example. It consists of a plurality of map values of display size/display brightness visible in the state. The visible map is used for display control for changing at least one of the display size and display brightness on the display 4 by the display control unit 15 based on the map values corresponding to each state.

Note that the mounting positions P1, P2, and P3 in FIG. It is not limited to only, and may correspond to other positions. The mounting position on the visible map may be set according to the distance from the occupant using the display 4 . In either case, the occupants to be used are those who sit in the driver's seat, the front passenger's seat, the rear seat, etc. of the own vehicle. , is set in advance by a user or the like.

In addition, although omitted in FIG. 6 for the sake of clarity, map values forming the visible map may include values corresponding to a plurality of states corresponding to reflection situations. As described above, the situation of reflection includes the presence or absence of reflection and its degree (for example, if there is reflection, is it uniform or complex?). A plurality of map values corresponding to the situation of reflection are set, for example, by creating isopower lines in the same manner as described above and using the isopower as a reference.

The display control unit 15 acquires information about the states of the display 4, the illuminance, and the occupant based on output signals from various sensors of the own vehicle, and based on these information, displays a map that constitutes a visible map. Select one of the values and execute the display control of the display 4 . For example, the display control unit 15 may select the map value closest to the equi-power line corresponding to the state in each state. In this case, the display control unit 15 selects a map value that minimizes power consumption and changes at least one of the display size and display brightness in display control.

Further, for example, the display control unit 15 may select a map value whose display brightness is closest to the isopower line while fixing the display size to the state before the display control, and execute control to change only the display brightness. and vice versa. In this case, the display control unit 15 performs control to change only one of the display size and the display brightness in the display control.

In this way, the display control unit 15 refers to the map values that make up the visible map, selects one of the corresponding map values in each state, and changes at least one of the display size/display brightness, Both ensuring visibility and suppressing increase in power consumption are achieved. Regarding the display control by the display control unit 15, for example, the power consumption is always minimized, the display size is fixed and only the display brightness is changed, the display brightness is fixed and only the display size is changed, etc. It may be determined by a user or the like setting in advance.

Note that the display control unit 15, for example, controls the display while maintaining the ratio of the luminance of the information portion to the luminance of the background portion, that is, the contrast ratio, at a certain level or more (for example, 3 or more) in order to ensure the visibility of the information part. may be executed.

[Processing operation]
Next, an example of display control by this display system will be described with reference to FIGS. 7 and 8. FIG.

This display system starts the control flow shown in FIG. 7, for example, when the ignition of the host vehicle is turned on or the display 4 is turned on or a predetermined start condition is satisfied.

In step S110, for example, the solar radiation estimation unit 12 uses the solar radiation area calculation unit 122 or the shadow calculation unit 123 to calculate the area distribution of the solar radiation area/non-solar radiation area on the display surface 4a, and the solar radiation on the display surface 4a of the display body 4. Estimate the area. For example, after step S110, the control unit 1 advances the process to step S120.

In step S<b>120 , for example, the shadow calculation unit 123 of the solar radiation estimation unit 12 calculates the reflection region R<b>2 on the display surface 4 a from the image data of the display 4 captured by the vehicle-mounted camera 21 . After steps S<b>110 and S<b>120 , the solar radiation estimating unit 12 outputs information on the estimated area distribution of the solar radiation area/non-solar radiation area and the reflection area to the display control unit 15 .

In step S<b>130 , for example, the illuminance acquisition unit 13 estimates the illuminance distribution on the display surface 4 a of the display 4 based on output signals from the plurality of illuminance sensors 23 . The illuminance acquisition unit 13 outputs information on the estimated illuminance distribution to the display control unit 15 .

In step S<b>140 , for example, the occupant information acquiring unit 14 acquires information about the solar radiation condition of the occupant based on the captured data of the predetermined region including the eyes of the occupant of the own vehicle captured by the occupant imaging unit 22 . The occupant information acquisition unit 14 outputs the acquired information about the solar radiation situation to the occupant to the display control unit 15 .

In step 140, for example, it may also be determined whether the occupant is in the sun or in the shade, according to the control flow shown in FIG.

In this case, for example, in step S141, the occupant information acquisition unit 14 first determines whether or not there is a predetermined difference or more in illuminance between the eye of the occupant to be imaged by the occupant imaging unit 22 and its surroundings. For example, if the determination in step S141 is affirmative, the occupant information acquiring unit 14 advances the process to step S145, and if the determination is negative, the process advances to step S142. A situation in which there is a predetermined difference in illuminance between the occupant's eyes and their surroundings is, for example, a sun visor installed on the vehicle that blocks the sun's rays on the occupant's eyes, causing the illuminance of the eyes to change to the illuminance of the surroundings. and the eyes are in the shade. The threshold for determining whether the difference is greater than or equal to a predetermined value is arbitrary and can be set as appropriate.

In step S142, for example, the occupant information acquiring unit 14 determines whether or not the eyes of the occupant to be imaged have been detected. advances the process to step S145. A situation in which the eyes of the occupant are not detected includes, for example, a situation in which the occupant to be imaged wears sunglasses to block solar radiation to the eyes of the occupant.

In step S143, for example, the occupant information acquiring unit 14 determines whether or not the illuminance of the occupant's eyes is equal to or greater than a predetermined threshold value. advances the process to step S145. The predetermined threshold in step S143 is appropriately set assuming the brightness of the sunlight (for example, about 20000 lx) that makes it difficult for the passenger to see the image on the display 4 .

Then, for example, the occupant information acquisition unit 14 determines that the occupant is in the sun in step S144, and determines that the occupant is in the shade in step S145. After that, the occupant information acquisition unit 14 outputs the determination result to the display control unit 15 as solar radiation information for the occupant.

In step S150, for example, the display control unit 15 acquires or estimates in steps S110 to S140, based on each information of the area distribution and reflection situation on the display surface 4a of the display body 4, and the solar radiation situation for the occupant. , to control the display of the display 4 . The display control unit 15, for example, refers to the visible map stored in the database unit 11, and selects one map value from a plurality of map values associated with the state corresponding to each acquired information. Specifically, the display control unit 15 selects one map value from the visible map for each of the solar radiation area, the non-solar radiation area, and the reflection area on the display surface 4a, and for each area, at least display size/display brightness Execute control to change one. The display control unit 15 outputs the image data after such display control to the video output unit 16 , and the video signal corresponding to the image data is output to the display 4 from the video output unit 16 . As a result, in each area of the display surface 4a of the display 4 having different states, a display that ensures visibility and suppresses an increase in power consumption is achieved while considering the solar radiation conditions of the display 4 and the occupant.

After step S150, the control unit 1 repeats the above processing until, for example, the display 4 is turned off.

Display control by the display system is executed by the operation processing as described above. Note that steps S110 to S140 do not necessarily have to be performed in this order, and may be performed in parallel, and the order may be changed as appropriate.

According to the display system according to the embodiment, the distribution of the solar radiation area/non-solar radiation area on the display surface 4a of the display body 4 is estimated by the solar radiation estimation unit 12, the environmental illumination is acquired by the illumination acquisition unit 13, and the solar radiation to the occupant is obtained. It is configured such that the situation is acquired by the occupant information acquisition unit 14 . In this display system, the display control unit 15 changes at least one of the display size/display brightness of the display content by referring to the visible map based on the solar radiation area, the illuminance, and the solar radiation conditions of the occupant on the display surface 4a. control. As a result, when sunlight or reflection occurs on the display surface 4a of the display body 4, visibility is ensured and power consumption is increased while performing display control for each area in consideration of the sunlight conditions of the occupant. It is possible to achieve both suppression.

(Other embodiments)
Although the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to such examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations including only one, more, or less elements thereof, are within the scope and spirit of this disclosure.

(1) The solar irradiation estimation unit 12 calculates the distribution of the solar irradiation area/non-solar irradiation area by the irradiation area calculation unit 122, calculates the shadow area R1 and the reflection area R2 by the shadow calculation unit 123, and combines them to obtain the final It is not limited to the configuration for estimating the solar radiation area. For example, the solar radiation estimation unit 12 may have the shadow calculation unit 123 calculate only the reflection region R2, or the shadow region R1 and the reflection region R2 calculated by the shadow calculation unit 123 may be calculated without using the solar irradiation region calculation unit 122. You may calculate distribution of a solar radiation area/non-solar radiation area based on.

(2) In the above description, the display control unit 15 can perform control to increase the brightness of the information portion based on the visible map when the occupant is in the sun. control may be exercised. This is because, when the occupant is in the sun, if the brightness of the background is low, the eyes may not be able to adapt and the visibility may deteriorate. Therefore, in order to hasten the adaptation of the eyes of the occupant, the display control unit 15 may increase the luminance of the background portion in addition to the information portion to be higher than that in the shaded state, and perform display control to ensure visibility. .

(3) The control unit 1 and its techniques described in the present disclosure are provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. It may be implemented by a computer. Alternatively, the controller 1 and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control unit 1 and techniques thereof described in this disclosure are a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. may be implemented by one or more dedicated computers configured by The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible recording medium.

4... display body 4a... display surface 11... database unit 12... solar radiation estimation unit 121... position acquisition unit 122... solar radiation area calculation unit 123... shadow calculator,
13... illumination acquisition unit, 14... occupant information acquisition unit, 15... display control unit,
20... In-vehicle device, 21... In-vehicle camera, 22... Passenger imaging unit,
R1: shadow area, R2: reflection area

Claims (9)

A vehicular display device that is mounted on a vehicle and executes luminance control of a self-luminous display body (4),
a solar radiation estimator (12) for estimating a solar radiation area on a display surface (4a) of the display on which an image is displayed;
an illuminance acquisition unit (13) that acquires illuminance information of an environment in which the display object is placed from an in-vehicle device (20) mounted in the vehicle;
an occupant information acquiring unit (14) for acquiring information of a predetermined region including the eyes of the occupant from an occupant imaging unit (22) for imaging the occupant of the vehicle;
Display of content to be displayed on the display surface based on the solar radiation area estimated by the solar radiation estimation unit, the illuminance information acquired by the illuminance acquisition unit, and the occupant's eye information acquired by the occupant information acquisition unit. and a display controller (15) that changes at least one of size and display brightness. The solar radiation estimation unit includes a position acquisition unit (121) that acquires vehicle information, which is information on the position and direction of the vehicle, from the on-vehicle device; 2. The vehicle display device according to claim 1, further comprising a solar irradiation area calculation unit (122) for calculating the direction of solar irradiation and the solar irradiation area. The solar radiation estimating unit calculates a shadow area ( 3. The vehicle display device according to claim 1, further comprising a shadow calculator (123) for calculating R1). 4. The vehicular display device according to claim 3, wherein said shadow calculator calculates a reflection region (R2) in which reflection occurs on said display surface based on said image. The vehicular display device according to any one of claims 1 to 4, wherein the occupant information acquiring unit determines whether or not the occupant's eyes are in a sunny state where the sun is shining. 6. The occupant information obtaining unit determines that the occupant's eyes are in a shaded state where sunlight is not shining when the occupant's eyes are not detected in the captured image of the occupant. 1. The vehicle display device according to claim 1. 7. The display control unit controls the display brightness to be higher in a sunny state where the occupant's eyes are exposed to sunlight than in a shaded state where the occupant's eyes are not exposed to sunlight. The vehicle display device according to any one of the above. When the occupant's eyes are exposed to sunlight, the display control unit sets a portion of the content displayed on the display surface, which is different from the information portion, as a background portion, in addition to the information portion, 8. The vehicular display device according to claim 7, wherein control is performed to make the brightness of the background portion higher than that of the shaded state. A plurality of map values of the display brightness and the display size of the display body that can be visually recognized by the occupant for each of the illuminance of the display surface, the presence or absence of solar radiation on the display surface, and the presence or absence of solar radiation to the eyes of the occupant. further comprising a database unit (11) storing a visible map consisting of
9. The vehicle according to any one of claims 1 to 8, wherein said display control unit performs control to change at least one of said display brightness and said display size based on said map value of said visible map. display device.

Images