Vehicle display device

Abstract

To reduce luminance unevenness.SOLUTION: A display device for a vehicle comprises a display 10, a reflection member 40 which reflects display light emitted from the display in a casing 61 to project it on a projection object part Rwf, and a control part 50 which controls the display light corresponding to an eye point EP or an eye box EB, and the display comprises a backlight unit 20 which diffuses and distributes the light of a light source 21 from an irradiation surface 20a, and a light transmission type plate-like display unit 30 which transmits the irradiation light from the irradiation surface, impinging on an irradiated surface 30a and emits it as the display light from an emission surface 30b. The display unit is tilted to the irradiation surface between the irradiation surface and the reflection member so that an interval between second end parts, creating an upper end of a virtual image, on the irradiation surface and the irradiated surface is wider than an interval between first end parts creating a lower end of the virtual image, and the control part makes the illuminance of the irradiation light from the irradiation surface impinging on the irradiated surface higher at the second end parts than at the first end parts so as to reduce illuminance unevenness of the display light emitted from the emission surface of the display unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, a vehicle is equipped with a vehicle display device that displays information to be provided to a passenger in the vehicle cabin as a virtual image. This vehicle display device is a so-called head-up display device, and includes a display device that emits display information to be projected on a projection target portion as display light, and a reflecting member that reflects the display light emitted from the display device and projects the display light on the projection target portion. This vehicle display device allows a passenger to visually recognize display information corresponding to the display light projected on the projection target portion as a virtual image. For example, this type of vehicle display device is disclosed in the following Patent Document 1. In the vehicle display device of Patent Document 1, since external light is reflected by a reflecting member and directed toward an exit surface of a light-transmitting display unit, the exit surface is tilted so that the external light does not return from the exit surface of the display unit to the reflecting member, thereby avoiding reflection of the external light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-101056 A Summary of the Invention [Problem to be solved by the invention]

[0004] A light-transmitting display unit transmits light from a backlight irradiated from the backside and emits it from the emission surface toward a reflecting member as display light. Conventional vehicle display devices tilt the display unit with respect to the optical axis of the backlight toward the reflecting member, and the brightness of the display unit decreases at places far from the backlight, resulting in uneven brightness.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a vehicle display device in which luminance unevenness is reduced. [Means for solving the problem]

[0006] The present invention provides a vehicle illumination device that includes a housing, a display device that emits display information as display light within the housing to be viewed as a virtual image by an occupant in a vehicle cabin, at least one reflecting member that reflects the display light emitted from the display device within the housing and projects the display light from an opening of the housing to a projection target portion within the vehicle cabin, and a control unit that controls the display light according to the eye point of the occupant or an eye box that is a range of the eye points at which the virtual image can be viewed, the display device including a backlight unit that diffuses and distributes light from a light source from an illumination surface, and a light-transmitting plate-shaped display unit that transmits the illumination light from the illumination surface that is incident on the illumination target surface and emits it from an emission surface as the display light. the display unit is tilted with respect to the illumination surface such that a distance between first ends that create a vertical lower end of the virtual image on the illumination surface and the irradiated surface is greater than a distance between second ends that create a vertical upper end of the virtual image on the illumination surface and the irradiated surface, between the illumination surface and the reflective member that is arranged in the optical axis direction of the backlight unit relative to the illumination surface; and the control unit controls the backlight unit to make the illuminance of the illumination light from the illumination surface that is incident on the irradiated surface higher at the first end than at the second end, thereby reducing brightness unevenness of the display light that is emitted from the emission surface of the display unit. Effect of the Invention

[0007] The vehicle display device of the present invention has a higher brightness at the first end of the exit surface of the display unit than at the second end, thereby reducing brightness unevenness of the display light emitted from the exit surface over the entire exit surface, thereby improving the visibility of the virtual image display. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a display device for a vehicle according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a display device according to the embodiment. [Diagram 3] FIG. 3 is an explanatory diagram showing an example of the arrangement of light sources. [Figure 4] FIG. 4 is an explanatory diagram illustrating the relationship between the emission angle and the light transmittance in the display unit. [Diagram 5] FIG. 5 is an explanatory diagram illustrating uneven luminance of a display unit. [Figure 6] FIG. 6 is an explanatory diagram showing an example of map data of luminance correction values ​​with respect to the illuminance of external light. [Figure 7] FIG. 7 is a schematic diagram showing a modified example of a display device for a vehicle. [Figure 8] FIG. 8 is a schematic diagram showing a display device of a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a display device for a vehicle according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these preferred embodiments.

[0010] [Embodiment] One embodiment of a display device for a vehicle according to the present invention will be described with reference to FIGS.

[0011] 1, reference numeral 1 denotes a vehicle display device according to an embodiment. The vehicle display device 1 is a so-called head-up display device that displays information to be provided to passengers in the cabin of a vehicle (such as an automobile) as a virtual image.

[0012] The vehicle display device 1 includes a display device 10 that emits display information to be viewed as a virtual image by passengers in the vehicle cabin as display light in a housing 61 described below (FIG. 1). The display device 10 includes a backlight unit 20 and a light-transmitting, plate-like display unit 30, and transmits light irradiated from the backlight unit 20 to the display unit 30, causing it to be emitted from the display unit 30 as display light for display information (FIG. 1).

[0013] Furthermore, the vehicle display device 1 includes at least one reflecting member that reflects the display light emitted from the display device 10 in the housing 61 and projects the display light from the opening 61a of the housing 61 to the projection target Rwf in the vehicle cabin. In this embodiment, one reflecting member 40 is included (FIG. 1). The reflecting member 40 is, for example, a magnifying mirror that magnifies and reflects the display light emitted from the display device 10. For example, an aspheric (free-form surface) mirror is used as the reflecting member 40. The display light projected to the projection target Rwf is reflected from the projection target Rwf to the eye point EP or eye box EB, and is visually recognized as a virtual image by the occupant (FIG. 1). The eye point EP indicates the position of the eyes of the occupant in the vehicle cabin. The eye box EB indicates the range of the eye point EP where the virtual image can be visually recognized.

[0014] The vehicle display device 1 includes a control unit 50 that controls display light according to the eye point EP or eye box EB of an occupant (FIG. 1).

[0015] The vehicle display device 1 further includes a housing 61 that houses at least the display device 10 and the reflecting member 40 therein, and a transparent cover 62 that closes an opening 61a of the housing 61 (FIG. 1). In the vehicle display device 1, the display light reflected by the reflecting member 40 is emitted from the cover 62 to the outside of the housing 61, and projected onto a projection target portion Rwf that exists beyond the housing 61. The vehicle display device 1 shown here is housed in an instrument panel Pi in a vehicle cabin with the cover 62 exposed, and projects the display light reflected by the reflecting member 40 onto the projection target portion Rwf (FIG. 1). The vehicle display device 1 reflects the display light from the projection target portion Rwf toward the eye point EP or the eye box EB.

[0016] Here, the projection target portion Rwf refers to the windshield (here, the front windshield Wf) itself or a part thereof. The projection target portion Rwf may be formed as a half mirror that receives display light from the reflecting member 40 on a reflecting surface, reflects it to the eye point EP or the eye box EB, and emits light from outside the vehicle toward the occupant. For example, the projection target portion Rwf as a half mirror is formed in a semi-transparent film shape that conforms to the curved shape of the windshield (front windshield Wf) and is attached to the wall surface of the windshield on the inside of the vehicle compartment with an adhesive. The projection target portion Rwf as a half mirror may be formed in a semi-transparent film shape that conforms to the curved shape of the windshield (front windshield Wf) and is sealed together with an intermediate film in the windshield of laminated glass. The projection target portion Rwf as a half mirror may be a semi-transparent coating that is coated by painting or the like on the wall surface of the windshield (front windshield Wf) on the inside of the vehicle compartment. The projection target portion Rwf may be a combiner that covers the front windshield Wf from the inside of the vehicle compartment.

[0017] The backlight unit 20 includes a light source 21, a control board 22 for the light source 21, and a heat sink 23 for dissipating heat generated by the light source 21 (FIG. 2). The light source 21 is a light-emitting element. Here, a light-emitting diode element is used as the light-emitting element. A plurality of light sources 21 are arranged between a first light source position related to light irradiated from a first end (vertical upper end) of the irradiation surface 20a described later and a second light source position related to light irradiated from a second end (vertical lower end) of the irradiation surface 20a. The backlight unit 20 shown here includes a plurality of light sources 21 arranged in the vertical direction. The control board 22 electrically connects the light source 21 to a power source via a wiring pattern. A plurality of light sources 21 are arranged at equal intervals in the vertical direction and in a direction perpendicular to the vertical direction on the board surface 22a of the control board 22 shown here (FIGS. 2 and 3).

[0018] Furthermore, the backlight unit 20 is provided with a focusing lens 24 that is disposed opposite the board surface 22a of the control board 22 and focuses light from the light source 21 (hereinafter referred to as "light source light") located between the control board 22 and the board surface 22a, and a field lens 25 that diffuses and distributes the light source light focused by the focusing lens 24 (Figure 2).

[0019] The condenser lens 24 is a lens member made of glass or transparent resin that condenses the light source light from the light source 21. The condenser lens 24 shown here is, for example, a condenser lens in which lens elements 24a for each light source 21 are arranged facing the light source 21. The lens element 24a has an entrance surface for the light source light from the light source 21 and an exit surface for exiting the light source light that has entered from the entrance surface, and is formed as a plano-convex lens in which the entrance surface is a flat surface and the exit surface is a convex curved surface.

[0020] Field lens 25 is a lens member made of glass or transparent resin that aligns the traveling direction of the light source light emitted from condenser lens 24, and is interposed between condenser lens 24 and display unit 30. Field lens 25 has an entrance surface onto which the light source light of each light source 21 is incident via condenser lens 24, and an exit surface from which the light source light incident from the entrance surface is emitted. For example, a Fresnel lens is used as field lens 25 shown here.

[0021] In the backlight unit 20, the emission surface of the field lens 25 becomes the irradiation surface 20a (FIG. 2), and the traveling directions of the light source light from each light source 21 via the condenser lens 24 are aligned by the field lens 25, and the light source light is diffused and distributed from the irradiation surface 20a. In the backlight unit 20, for example, the direction perpendicular to the board surface 22a of the control board 22 or the direction perpendicular to the incident surface of the lens element 24a of the condenser lens 24 becomes the optical axis direction. In the backlight unit 20, the light source light emitted from the irradiation surface 20a is irradiated onto the display unit 30 as irradiation light.

[0022] The display unit 30 causes the light irradiated from the irradiated surface 20a of the backlight unit 20 to enter the irradiated surface 30a on the back side, and emits the display light of the display information from the emission surface 30b on the front side toward the reflecting member 40 (FIG. 2). The display unit 30 transmits the light irradiated from the irradiated surface 20a that has entered the irradiated surface 30a, and emits it from the emission surface 30b as display light. The display unit 30 shown here uses a light-transmitting TFT liquid crystal (Thin Film Transistor Liquid Crystal Display). The display unit 30 is controlled by a control unit 50 to display the display information. For example, image information such as letters, numbers, and figures is displayed as the display information.

[0023] The display unit 30 is inclined with respect to the irradiated surface 20a so that the distance between the first ends that create the lower ends of the virtual image in the vertical direction on the irradiated surface 20a and the irradiated surface 30a is wider than the distance between the second ends that create the upper ends of the virtual image in the vertical direction on the irradiated surface 20a and the irradiated surface 30a between the irradiated surface 20a and the reflective member 40 arranged in the optical axis direction of the backlight unit 20 with respect to the irradiated surface 20a. The irradiated surface 20a and the irradiated surface 30a in this embodiment are each installed in an arrangement in which the vertical upper side is the first end and the vertical lower side is the second end. Therefore, the display unit 30 is inclined with respect to the irradiated surface 20a so that the distance between the upper ends of the irradiated surface 20a and the irradiated surface 30a in the vertical upper direction is wider than the distance between the lower ends of the irradiated surface 20a and the irradiated surface 30a in the vertical lower direction between the irradiated surface 20a and the reflective member 40 (FIG. 2). The illumination surfaces 20a of the display unit 30 and backlight unit 20 shown here are each tilted with their vertically downward lower ends as the center of rotation and their vertically upward upper ends tilted toward the front of the vehicle. In this vehicle display device 1, the inclination angle of the display unit 30 is made larger than the inclination angle of the illumination surface 20a of the backlight unit 20, so that the optical axis of the backlight unit 20 intersects the illumination surface 30a and the emission surface 30b of the display unit 30 without being perpendicular thereto.

[0024] Specifically, in order to prevent reflection of external light, the display unit 30 shown here is tilted with respect to the irradiation surface 20a of the backlight unit 20 so that when external light entering through the opening 61a of the housing 61 is reflected by the reflecting member 40 and reaches the exit surface 30b, the external light reflected by the exit surface 30b is not directed toward the reflecting member 40. For example, here, the external light reflected by the exit surface 30b is directed toward the bottom wall of the housing 61 (FIG. 1).

[0025] In this manner, in the vehicle display device 1, the optical axis direction of the backlight unit 20 intersects with the direction perpendicular to the irradiated surface 30a and the emission surface 30b of the display unit 30. Therefore, in the display unit 30, the absolute value of the emission angle θ (FIG. 2) of the display light emitted from the emission surface 30b with respect to the reference emission direction (here, the direction perpendicular to the emission surface 30b) is larger at the upper end than at the lower end (θ2>θ1). For example, in the display unit 30 shown here, the display light is emitted from the lower end of the emission surface 30b at a negative emission angle θ with respect to the reference emission direction, and the absolute value of the negative emission angle θ of the display light with respect to the reference emission direction becomes smaller toward the upper end from the lower end, and the display light is emitted toward the reference emission direction at a certain position (θ=0). In the display unit 30 shown here, the positive emission angle θ of the display light with respect to the reference emission direction increases as one moves from the positive / negative switching position (θ=0) toward the upper end, and at a certain position the absolute value of this positive emission angle θ becomes the same as the absolute value of the negative emission angle θ at the lower end, and the positive emission angle θ of the display light with respect to the reference emission direction becomes even larger as one moves toward the upper end from this position.

[0026] Here, the display unit 30 has the highest light transmittance T(θ) when the emission angle θ of the display light with respect to the reference emission direction is 0 degrees, and the light transmittance T(θ) decreases as the emission angle θ of the display light with respect to the reference emission direction increases regardless of whether it is positive or negative (FIG. 4). That is, the display unit 30 has the highest luminance L(θ) when the emission angle θ of the display light with respect to the reference emission direction is 0 degrees, and the luminance L(θ) decreases as the emission angle θ of the display light with respect to the reference emission direction increases regardless of whether it is positive or negative. For this reason, in the display unit 30, if the illuminance of the light emitted from the illumination surface 20a of the backlight unit 20 that is incident on the illuminated surface 30a is uniform over the entire surface of the illuminated surface 30a, the luminance L(θ) at the upper end where the distance between the illuminated surface 30a and the illumination surface 20a is wider than at the lower end will be lower than that at the lower end, resulting in uneven luminance (FIG. 5). For example, in this display unit 30, when a first region in which the absolute value of the emission angle θ of the display light with respect to the reference emission direction is suppressed to a certain value or less and a second region in which the absolute value of the emission angle θ exceeds a certain value and becomes larger are mixed on the emission surface 30b, luminance unevenness occurs between the first region and the second region, which gives an uncomfortable feeling to the virtual image display. In this case, the first region is from the lower end to just before the upper end of the emission surface 30b, and the luminance L(θ) is significantly lower at the upper end of the emission surface 30b, which is the second region, than in the first region.

[0027] Therefore, the control unit 50 reduces the luminance unevenness of the display unit 30 by controlling the backlight unit 20. The control unit 50 controls the backlight unit 20 to make the illuminance of the light emitted from the irradiated surface 20a of the backlight unit 20, which is incident on the irradiated surface 30a of the display unit 30, higher at the first end than at the second end (i.e., higher at the upper end in the vertical direction than at the lower end in the vertical direction), thereby reducing the luminance unevenness of the display light emitted from the emission surface 30b of the display unit 30. In other words, this control unit 50 makes the illuminance of the light emitted from the illumination surface 20a of the backlight unit 20 onto the illuminated surface 30a of the display unit 30 higher at the first end of the illuminated surface 30a than at the second end (i.e., higher at the vertical upper end than the vertical lower end), and makes the luminance L(θ) higher at the first end of the emission surface 30b of the display unit 30 than at the second end (i.e., higher at the vertical upper end than the vertical lower end), thereby reducing luminance unevenness of the display light emitted from the emission surface 30b over the entire emission surface 30b.

[0028] Specifically, the control unit 50 makes the luminance of the light source 21 arranged at the first light source position (i.e., the upper end vertically above) in the arrangement direction of the light sources 21 in the backlight unit 20 higher than the luminance of the light source 21 arranged at the second light source position side (i.e., vertically below) to make the illuminance of the light emitted from the irradiated surface 20a of the backlight unit 20 incident on the irradiated surface 30a of the display unit 30 higher at the first end than at the second end (i.e., at the upper end in the vertical direction than at the lower end in the vertical direction). For example, the control unit 50 calculates the luminance L(θ) of the location to be controlled (here, the upper end of the emission surface 30b) from the following formula 1 based on the luminance L(θmin) and light transmittance T(θmin) at the location where the absolute value of the emission angle θ of the display light with respect to the reference emission direction is minimum. Then, the control unit 50 controls the luminance of the light source 21 corresponding to the location to be controlled (here, the upper end of the emission surface 30b) so as to approach this luminance L(θ) based on the calculated value of the luminance L(θ).

[0029] L(θ)={T(θmin) / T(θ)}*L(θmin) ···(1)

[0030] In this manner, the vehicle display device 1 of this embodiment has a higher luminance L(θ) at the first end of the exit surface 30b of the display unit 30 than at the second end (i.e., at the upper vertical end than the lower vertical end), thereby reducing luminance unevenness of the display light emitted from the exit surface 30b over the entire exit surface 30b, thereby improving the visibility of the virtual image display.

[0031] However, strictly speaking, in the display unit 30, the absolute value of the emission angle θ of the display light with respect to the reference emission direction differs at each position on the emission surface 30b, and therefore, a deviation occurs in the luminance L(θ) at each position. Therefore, strictly speaking, in this display unit 30, luminance unevenness occurs even in places where the effect on the visibility of the virtual image display is small.

[0032] Therefore, first, the emission surface 30b of the display unit 30 is divided into a plurality of divided areas. For example, the emission surface 30b is divided into a plurality of divided areas arranged at equal intervals in the vertical direction and in a direction perpendicular to the vertical direction. The control unit 50 calculates the luminance L(θ) of each divided area except for the divided area in which the absolute value of the emission angle θ of the display light with respect to the reference emission direction is the smallest based on the above formula 1. The control unit 50 controls the luminance of the light source 21 corresponding to the divided area to be controlled based on the calculated value of the luminance L(θ) of each divided area so as to approach this luminance L(θ). As a result, the vehicle display device 1 can further reduce the luminance unevenness of the display light emitted from the emission surface 30b of the display unit 30 over the entire emission surface 30b, thereby further improving the visibility of the virtual image display.

[0033] In addition, the control unit 50 may adjust the illuminance of the light irradiated from the irradiating surface 20a of the backlight unit 20 to be incident on the irradiated surface 30a of the display unit 30 for each divided area according to the illuminance of the external light for each divided area, thereby reducing the luminance unevenness of the display light emitted from the emitting surface 30b of the display unit 30. In this case, the vehicle display device 1 is provided with an illuminometer for each divided area that measures the illuminance of the external light reflected from the reflecting member 40. Alternatively, the vehicle display device 1 measures the illuminance of the external light incident from the opening 61a of the housing 61 with an illuminometer, and causes the control unit 50 to estimate the illuminance of the external light for each divided area based on the measurement result. For example, the control unit 50 is provided with map data of the luminance correction value L(S) according to the illuminance of the external light (FIG. 6), and calculates the luminance correction value L(S) according to the illuminance of the external light for each divided area from the map data. For example, the luminance correction value L(S) is used as a correction coefficient, and the luminance L(θ) of the divided area to be controlled is calculated from the following formula 2.

[0034] L(θ)={T(θmin) / T(θ)}*L(θmin)*L(S)...(2)

[0035] Based on the calculated value of the luminance L(θ), the control unit 50 controls the luminance of the light source 21 corresponding to the partitioned area to be controlled so as to approach the luminance L(θ). As a result, the vehicle display device 1 can eliminate the influence of external light and further reduce the luminance unevenness of the display light emitted from the emission surface 30b of the display unit 30 over the entire emission surface 30b, thereby further improving the visibility of the virtual image display.

[0036] [Variations] The vehicle display device 2 of this modified example is different from the vehicle display device 1 of the above-described embodiment in that the mounting angle of the display device 10 is changed and another reflective member is added (FIG. 7).

[0037] The vehicle display device 2 includes a first reflecting member 141 that reflects the display light emitted from the display 10, and a second reflecting member 142 that reflects the display light reflected by the first reflecting member 141 and projects it onto the projection area Rwf through the opening 61a of the housing 61 (FIG. 7). The first reflecting member 141 is a folding mirror. The second reflecting member 142 is a magnifying mirror similar to the reflecting member 40 of the embodiment.

[0038] The display unit 30 of the display device 10 of this modification is inclined with respect to the irradiation surface 20a in the same manner as the display device 10 of the embodiment, so that the distance between the first ends that create the lower end of the virtual image in the vertical direction on the irradiation surface 20a and the irradiated surface 30a between the irradiation surface 20a and the reflective member 40 is wider than the distance between the second ends that create the upper end of the virtual image in the vertical direction on the irradiation surface 20a and the irradiated surface 30a. However, the display device 10 of the embodiment is arranged so that the display light is emitted from the emission surface 30b of the display unit 30 toward the front of the vehicle. On the other hand, the display device 10 of this modification is arranged so that the display light is emitted from the emission surface 30b of the display unit 30 toward the vertical upward side (i.e., toward the upper side of the vehicle) or the vertical downward side (i.e., toward the lower side of the vehicle). Therefore, the display device 10 of this modification adopts the following configuration.

[0039] The illumination surface 20a and the illumination target surface 30a of this modification are disposed such that one end side in a direction perpendicular to the vertical direction is a first end and the other end side in a direction perpendicular to the vertical direction is a second end. The light sources 21 of this modification are arranged between a first light source position related to the light irradiated from the first end of the illumination surface 20a of this modification and a second light source position related to the light irradiated from the second end of the illumination surface 20a. The display unit 30 is inclined with respect to the illumination surface 20a so that the distance between the other ends of the illumination surface 20a and the illumination target surface 30a is wider than the distance between the one ends of the illumination surface 20a and the illumination target surface 30a between the illumination surface 20a and the first reflecting member 141.

[0040] In this example, display light is emitted from the emission surface 30b of the display unit 30 toward the vertically upward side (i.e., toward the upper side of the vehicle) to create a virtual image in front of the vehicle (FIG. 7). Therefore, the irradiated surface 20a and the irradiated surface 30a shown here are disposed so that the first end is on the vehicle front side and the second end is on the vehicle rear side (FIG. 8). The backlight unit 20 shown here includes a plurality of light sources 21 arranged in the vehicle front-rear direction (FIG. 8). The display unit 30 shown here is inclined with respect to the irradiated surface 20a so that the distance between the ends of the irradiated surface 20a and the irradiated surface 30a on the vehicle front side is wider than the distance between the ends of the irradiated surface 20a and the irradiated surface 30a on the vehicle rear side between the irradiated surface 20a and the first reflecting member 141 (FIG. 7).

[0041] The control unit 50 of this modification controls the backlight unit 20, and makes the illuminance of the light emitted from the illumination surface 20a of the backlight unit 20 incident on the illuminated surface 30a of the display unit 30 higher at one end than at the other end (i.e., higher at the end on the vehicle front side than the end on the vehicle rear side), thereby reducing the luminance unevenness of the display light emitted from the emission surface 30b of the display unit 30. That is, the control unit 50 makes the illuminance of the light emitted from the illumination surface 20a of the backlight unit 20 incident on the illuminated surface 30a of the display unit 30 higher at one end than at the other end of the illuminated surface 30a (i.e., higher at the end on the vehicle front side than the end on the vehicle rear side), and makes the luminance L(θ) higher at one end than at the other end of the emission surface 30b of the display unit 30 (i.e., higher at the end on the vehicle front side than the end on the vehicle rear side), thereby reducing the luminance unevenness of the display light emitted from the emission surface 30b over the entire emission surface 30b.

[0042] Specifically, the control unit 50 of this modified example increases the luminance of the light source 21 arranged on the first light source position side (i.e., the front of the vehicle) in the arrangement direction of the light sources 21 in the backlight unit 20 compared to the luminance of the light source 21 arranged on the second light source position (i.e., the end toward the rear of the vehicle), and makes the illuminance of the light emitted from the illumination surface 20a of the backlight unit 20 that is incident on the illuminated surface 30a of the display unit 30 higher at one end than at the other end (i.e., at the end toward the front of the vehicle than the end toward the rear of the vehicle).

[0043] Even if the first reflecting member (folding mirror) 141 is interposed between the display 10 and the second reflecting member (magnifying mirror) 142 in this manner, the vehicle display device 2 of this modified example can achieve the same effects as the vehicle display device 1 of the embodiment. [Explanation of symbols]

[0044] 1,2 Vehicle display device 10 Display 20 Backlight unit 20a Irradiation surface 21 Light source 30 Display Unit 30a Irradiated surface 30b Output surface 40 Reflective material 50 Control section 61 Case 61a aperture 141 First reflecting member 142 Second reflecting member EB Eye Box EP Eyepoint Rwf Projection area

Claims

1. A housing and a display unit that emits display information as display light within the housing so that the display information is visually recognized as a virtual image by an occupant in the vehicle cabin; at least one reflecting member that reflects the display light emitted from the display unit inside the housing and projects the display light through an opening of the housing onto a projection target within a vehicle interior; a control unit that controls the display light according to an eye point of the occupant or an eye box that is a range of the eye points at which the virtual image can be viewed; Equipped with The display device includes a backlight unit that diffuses and distributes light from a light source from an irradiation surface, and a light-transmitting plate-like display unit that transmits the light irradiated from the irradiation surface and incident on an irradiated surface and emits the light from an emission surface as the display light, the display unit is tilted with respect to the illumination surface such that a distance between first ends that generate a lower end of the virtual image in the vertical direction on the illumination surface and the illuminated surface is larger than a distance between second ends that generate an upper end of the virtual image in the vertical direction on the illumination surface and the illuminated surface, between the illumination surface and the reflecting member that is disposed in a direction of an optical axis of the backlight unit with respect to the illumination surface; The control unit controls the backlight unit to make the illuminance of the irradiation light from the irradiation surface incident on the irradiated surface higher at the first end than at the second end, thereby reducing brightness unevenness of the display light emitted from the exit surface of the display unit.

2. The light source is arranged in a plurality of positions between a first light source position associated with the light irradiated from the first end of the irradiation surface and a second light source position associated with the light irradiated from the second end of the irradiation surface, 2. The vehicle display device according to claim 1, wherein the control unit increases the luminance of the light source arranged on the first light source position side in the arrangement direction of the light sources compared to the luminance of the light source arranged on the second light source position, thereby making the illuminance of the light emitted from the irradiation surface incident on the irradiated surface higher at the first end than at the second end.

3. 3. The vehicle display device according to claim 1 or 2, wherein the display unit is tilted with respect to the irradiation surface so that when external light entering through the opening of the housing is reflected by the reflective member and reaches the exit surface, the external light reflected by the exit surface is not directed toward the reflective member.

4. 4. The vehicle display device according to claim 3, wherein the control unit adjusts the illuminance of the irradiation light from the irradiation surface that is incident on the irradiated surface for each of the divided areas obtained by dividing the exit surface of the display unit into a plurality of areas in accordance with the illuminance of the external light for each of the divided areas, thereby reducing brightness unevenness of the display light that is emitted from the exit surface of the display unit.

5. a reflecting member provided between the display and the opening of the housing; the irradiating surface and the irradiated surface are each disposed such that a vertically upper side is the first end and a vertically lower side is the second end, the display unit is tilted with respect to the illumination surface such that a distance between upper ends of the illumination surface and the illumination target surface in a vertically upward direction is greater than a distance between lower ends of the illumination surface and the illumination target surface in a vertically downward direction, between the illumination surface and the reflection member; The vehicle display device according to claim 1 or 2, characterized in that the control unit controls the backlight unit to make the illuminance of the light from the irradiation surface incident on the irradiated surface higher at the upper end than at the lower end.

6. a first reflecting member that reflects the display light emitted from the display device, and a second reflecting member that reflects the display light reflected by the first reflecting member and projects the display light from the opening of the housing onto the projection target portion, The irradiating surface and the irradiated surface are each disposed such that one end side in a direction perpendicular to a vertical direction is the first end and the other end side in the perpendicular direction is the second end, the display unit is tilted with respect to the irradiation surface such that a distance between the one ends of the irradiation surface and the irradiated surface is larger than a distance between the other ends of the irradiation surface and the irradiated surface between the irradiation surface and the first reflecting member, The vehicle display device according to claim 1 or 2, characterized in that the control unit controls the backlight unit to make the illuminance of the light from the irradiation surface incident on the irradiated surface higher at the one end than at the other end.

Images