JP2020095101A - Vehicular display device - Google Patents

Abstract

To provide a vehicular display device capable of preventing return light when external light such as a headlight is radiated and also improving brightness of an aerial image.SOLUTION: A vehicular display device 1 is provided as one embodiment of the present invention that comprises a second retroreflective member 5 provided so as to block incidence of external light, parallel to a horizontal direction, to a retroreflective member 3. The second retroreflective member 5 has, on the side of a light branch member 4, a retroreflective surface 5a for retroreflecting incident light.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle display device.

Display device for forming an image of a light source in the air using a retroreflective member that reflects incident light in the incident direction and a light branching member that reflects a part of the incident light and transmits a part thereof It has been known. In this display device, a part of the light from the light source is reflected by the light branching member and emitted to the retroreflection member. Part of the light retroreflected by the retroreflective member passes through the light branching member and forms an image of the light source in the air. Hereinafter, the image of the light source formed in the air is referred to as an aerial image.

JP 2012-247458 A

In the display device described above, when light from the outside (referred to as external light) is incident on the retroreflective member through the light branching member, the light is retroreflected by the retroreflective member and emitted in the incident direction. Especially in an environment exposed to headlight light, such as at night, headlight light may enter the retroreflective member through the light branching member, and the return light may cause dazzling of drivers of other vehicles and pedestrians. There is.

Patent Document 1 describes that a semi-transmissive plate is used to weaken outside light. However, even in this case, return light is still generated by the retroreflective member, and the return light causes other light. May cause dazzling of car drivers and pedestrians.

An object of the present invention is to provide a vehicular display device capable of suppressing return light when external light such as a headlight is emitted and improving the brightness of an aerial image.

In order to achieve the above object, one aspect of the present invention provides the following vehicle display devices [1] to [7].

[1] A light source, a retroreflective member that is disposed below the light source and that retroreflects incident light, and reflects at least a part of the light from the light source and emits it to the retroreflective member. A light branching member that transmits at least a part of the light that is retroreflected by the retroreflective member and is incident, and the light that is retroreflected by the retroreflective member and that has passed through the light branching member is an image of the light source. A second retroreflective member is provided, which is configured to form a certain aerial image in the air and is provided so as to block the incidence of external light parallel to the horizontal direction on the retroreflective member. Is a display device for a vehicle having a retroreflective surface on the light branching member side that retroreflects incident light.

[2] The light source has a diffuser capable of diffusing the return light retroreflected by the retroreflective surface of the second retroreflective member and returned to the light source, and emitting the light again to the light branching member. The display device for a vehicle according to [1].

[3] The vehicle display device according to [1] or [2], wherein the second retroreflective member has a light-shielding layer capable of shielding incident external light on the incident side of external light.

[4] Any of [1] to [3], further comprising a semi-transmissive cover that is provided so as to cover the surface of the light branching member on the side of the aerial image and that transmits a part of incident visible light. 2. The vehicle display device according to item 1.

[5] The light branching member is formed of a reflective polarizing plate that reflects a specific polarized light and transmits a polarized light orthogonal to the specific polarized light, and is arranged so as to cover the outside light incident side of the light branching member. , A polarizing plate capable of transmitting the specific polarized light, and disposed between the polarizing plate and the light branching member, respectively, to convert the electric field oscillation direction of incident light into a direction of passing through the light branching member. As described above, the outer wave plate that gives a phase difference is disposed between the light branching member and the retroreflective member, and the electric field oscillation direction of the retroreflected light with respect to external light is reflected by the light branching member. And an inner wave plate that gives a phase difference so that the electric field oscillation direction after retroreflection for light from the light source is changed to a direction that passes through the light branching portion. The vehicle display device according to any one of [1] to [4].

[6] A polarizing plate for a light source, which is arranged between the light source and the light branching member and which can transmit the specific polarized light, is arranged between the second retroreflective member and the light branching member, and For the light, the electric field vibration direction of the light after retroreflection is converted to the direction of passing through the light branching member, and for the light from the light source, the electric field vibration direction after the retroreflection is the light. The vehicular display device according to [5], further comprising: a second retroreflective member wave plate that gives a phase difference so as to convert the branching member into a reflecting direction.

[7] The retroreflective member and the second retroreflective member, each of which is provided with an entrance/exit angle limiting member that restricts an incoming/outgoing direction of light in the retroreflective member or the second retroreflective member, respectively. ] The display device for vehicles as described in any one of [6].

[8] The vehicle display device according to any one of [1] to [7], which is attached to a vehicle body of a vehicle and configured to form an image of the light source outside the vehicle body. ..

According to the present invention, it is possible to provide a vehicular display device capable of suppressing return light when external light such as a headlight is emitted and improving the brightness of an aerial image.

FIG. 1 is a schematic configuration diagram of a vehicle display device according to an embodiment of the present invention. FIG. 2 is an explanatory diagram illustrating suppression of return light of external light in the vehicle display device of FIG. 1. FIG. 3A is a schematic configuration diagram when the vehicle display device of FIG. 1 is attached to a vehicle, and FIG. 3B is a diagram showing an example of displaying an aerial image outside the vehicle body. FIG. 4 is a schematic configuration diagram of a vehicle display device according to an embodiment of the present invention. FIG. 5 is a schematic configuration diagram of a vehicle display device according to an embodiment of the present invention.

[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Overall structure of vehicle display device)
FIG. 1 is a schematic configuration diagram of a vehicle display device according to the present embodiment. As shown in FIG. 1, the vehicle display device 1 includes a light source 2, a retroreflective member (retroreflector) 3, a light splitting member (beam splitter) 4, a second retroreflective member 5, a cover 7, Is equipped with.

As the light source 2, for example, a plate-shaped display device in which a plurality of LEDs (light emitting diodes) are arranged can be used. Further, as the light source 2, for example, a light source having one or more LEDs and a diffuser that diffuses light from the LEDs can be used. Further, as the light source 2, a display (display device) such as a liquid crystal display can be used.

In the present embodiment, the light source 2 having a diffuser is used. The diffuser may be, for example, a sealing resin that seals a chip in each LED, or a light guide that diffuses light emitted from the LED may be provided separately from the LED. This diffuser diffuses the return light that is retroreflected by the retroreflective surface 5a of the second retroreflective member 5 to be described later and returns to the light source 2, and weakens the light emitted to the LED, thereby preventing damage to the LED. Further, by causing a part of the light to be emitted again to the light branching member 4, it plays a role of improving the light use efficiency.

The retroreflective member 3 is a member that performs retroreflection to reflect incident light in the incident direction. As the retroreflective member 3, a retroreflective sheet formed in a sheet shape can be used. The retroreflective member 3 may have a structure that is generally used, for example, one using glass beads or one using a prism. In the present embodiment, the retroreflective member 3 is arranged below the light source 2.

The light branching member 4 is formed in a plate shape and reflects a part of the incident light and transmits a part thereof. A half mirror can be used as the light branching member 4. The light branching member 4 is not limited to a half mirror, and is a plate-shaped member made of acrylic or glass, a plate having an opening row such as punching metal, a wire grid film, a reflective polarizing film, and other generally called a beam splitter. One can be used.

The light branching member 4 reflects at least a part of the light from the light source 2 and outputs the light to the retroreflective member 3, and also transmits at least a part of the light retroreflected by the retroreflective member 3 and incident. Thereby, the light retroreflected by the retroreflective member 3 and transmitted through the light branching member 4 forms an image of the light source 2 in the air. Hereinafter, the image of the light source 2 formed in the air will be referred to as an aerial image 6.

(Second retroreflective member 5)
The second retroreflective member 5 has a role of blocking external light parallel to the horizontal direction of the headlight and the like, and also retroreflects light incident from below (on the side of the light branching member 4) to return it to the light branching member 4, This is a member that also serves to make the aerial image 6 brighter by forming an image in the same place as the aerial image 6 by the reflecting member 3 to improve the utilization efficiency of light transmitted through the light branching member 4. The second retroreflective member 5 is provided so as to block the incidence of external light parallel to the horizontal direction on the retroreflective member 3.

The second retroreflective member 5 is arranged at a position that does not affect the aerial image 6. That is, the second retroreflective member 5 is arranged so as not to block the optical path of light that is retroreflected by the retroreflective member 3 and forms the aerial image 6. The second retroreflective member 5 is provided below the optical path of the light that forms the aerial image 6 (on the lower right side in the drawing, opposite to the light source 2) and is closer to the aerial image 6 than the light branching member 4. It is provided on the upper right side in the figure.

As the second retroreflective member 5, as with the above-described retroreflective member 3, a retroreflective sheet formed in a sheet shape can be used. As the second retroreflective member 5, for example, one using glass beads or one using a prism can be used.

The second retroreflective member 5 has, on the side of the light branching member 4, a retroreflective surface 5a that retroreflects incident light. The light from the light source 2 that is retroreflected by the retroreflective surface 5a returns to the light branching member 4 side, and a part of the light is reflected by the light branching member 4 to the same position as the aerial image 6 by the retroreflective member 3. Image to. Further, a part of the light passes through the light branching member 4, returns to the light source 2, is diffused by the diffuser, and is emitted to the light branching member 4 again. As described above, the provision of the second retroreflective member 5 improves the light utilization efficiency and contributes to the high brightness of the aerial image 6.

Further, the second retroreflective member 5 has a light blocking layer 5b capable of blocking the incident external light on the incident side of the external light such as headlight light (the back side of the retroreflective surface 5a). Although the details will be described later, since the vehicle display device 1 according to the present embodiment is provided on the back door 12 of the vehicle 10, the light shielding layer 5b serves as the light shielding layer 5b so as not to reflect sunlight or the like to the rear of the vehicle 10. It is desirable to use a material having a low reflectance as much as possible. The light shielding layer 5b can be formed of, for example, a black resin layer or the like.

It can be said that it is desirable that the second retroreflective member 5 covers as wide a range as possible from the viewpoint of blocking more external light and improving the light utilization efficiency. That is, the second retroreflective member 5 covers as wide a range as possible in the range where the aerial image 6 is not affected (the region below the optical path of the light that forms the aerial image 6 (the lower right side in the drawing)). Is desirable. That is, it can be said that it is most desirable to cover the entire back surface of the light source 2 and the light branching member 4 in a region below the optical path of the light that forms the aerial image 6 (on the lower right side in the drawing). ..

The light blocking layer 5b does not necessarily have to be configured to completely block the incident light, and the second retroreflective member 5 attenuates the light incident from the horizontal direction toward the retroreflective member 3 to some extent. It may be configured to do so. Then, the light reflected in the horizontal direction by the retroreflective member 3 is reflected by the retroreflective surface 5 a of the second retroreflective member 5 and is confined. As a result, the following vehicles are not dazzled.

(Cover 7)
The cover 7 is for protecting the light source 2, the retroreflective member 3, the light branching member 4, and the second retroreflective member 5, and is provided so as to cover the surface of the light branching member 4 on the aerial image 6 side. ing. In the present embodiment, as the cover 7, a semi-transmissive cover that transmits a part of the incident visible light is used. As the semi-transparent cover 7, it is possible to use, for example, one made of colored resin, or one having a resin surface coated with semi-permeable or plated.

(Suppression of return light of outside light)
As shown in FIG. 2, by providing the second retroreflective member 5, external light such as headlight light that is parallel to the horizontal direction is blocked by the second retroreflective member 5 and is prevented from entering the retroreflective member 3. To be done. Even if a part of the external light such as headlight light which is parallel to the horizontal direction is transmitted through the second retroreflective member 5 and is incident on and reflected by the retroreflective member 3, the light is reflected by the second retroreflective member 5. The light can be confined by being reflected by the retroreflective surface 5a. As a result, it is possible to suppress the generation of return light such as headlight light, and it is possible to suppress the dazzling of the driver of another vehicle or the pedestrian.

In addition, with respect to external light such as sunlight that enters the retroreflective member 3 from a direction different from the horizontal direction (external light that enters from a portion that is not covered by the second retroreflective member 5), the semitransparent cover 7 is used. Attenuate the returning light. Since the external light passes through the twice semi-transparent cover 7 at the time of incidence and at the time of emission, the returned light emitted is greatly attenuated. For example, when the semi-transmissive cover 7 has a light intensity of the transmitted light which is 1/10 of the light intensity of the incident light, the light intensity of the emitted return light is the light intensity of the incident visible light. 1/100 of On the other hand, the light from the light source 2 that forms the aerial image 6 passes through the cover 7 only once, so the amount of attenuation is small. Therefore, it is possible to significantly suppress the returning light of the external light while suppressing the decrease in the brightness of the aerial image 6.

(Apply to vehicle)
FIG. 3A is a schematic configuration diagram when the vehicular display device 1 of FIG. 1 is attached to a vehicle, and FIG. 3B is a diagram showing an example of display of the aerial image 6 outside the vehicle body. is there. As shown in FIGS. 1 and 3A and 3B, the vehicular display device 1 is attached to a vehicle body 11 of a vehicle 10 and is configured to form an aerial image 6 outside the vehicle body 11. ing. In the present embodiment, the vehicle display device 1 is provided in the back door (rear hatch) 12 of the vehicle 10 and is configured to form the aerial image 6 behind the back door 12.

In the vehicle display device 1, the light source 2 is provided on the outer surface of the metal plate 121 outside the back door 12, and its optical axis is provided behind and above the vehicle 10 (obliquely upward). There is. The light branching member 4 is provided so as to face the light source 2. The retroreflective member 3 is arranged behind and below the light source 2 so as to face the light branching member 4, and is arranged so as to have a smaller inclination angle with respect to the horizontal direction than the light branching member 4.

The second retroreflective member 5 is provided behind and above (obliquely above) the light branching member 4, and is provided at a position facing the retroreflective member 3 in the horizontal direction with the light branching member 4 interposed therebetween. .. In the present embodiment, the second retroreflective member 5 is attached and fixed to the inner peripheral surface of the cover 7. The inclination angle of the second retroreflective member 5 with respect to the horizontal direction is larger than the inclination angle of the retroreflective member 3 and the light branching member 4 with respect to the horizontal direction.

In the present embodiment, the cover 7 also serves to cover the license light 13 that illuminates the license plate (not shown). The retroreflective member 3 is provided so as to close the space between the sheet metal 121 and the cover 7 in order to block the light from the number lamp 13. The retroreflective member 3 is configured so that its surface (upper surface in the drawing) is retroreflected, and its back surface (lower surface in the drawing) is a member that can shield light from the number lamp 13. (For example, a black resin layer or the like). Note that reference numeral 122 in FIG. 3A represents an inner trim of the back door 12.

In the present embodiment, the light that forms the aerial image 6 passes through the curved cover 7, and therefore the aerial image 6 may be distorted due to the influence of the cover 7. Therefore, cover distortion correction means for correcting the distortion of the aerial image 6 due to the influence of the cover 7 may be further provided. As the cover distortion correction means, for example, a member capable of correcting distortion caused by the cover 7 (such as the same material as the cover 7 but having an inverse shape) is disposed between the light source 2 and the light branching member 4, or It is possible to change the image of the original light source 2 so that the intended aerial image 6 is obtained by being distorted by the influence of 7.

Further, the light source 2, the retroreflective member 3, and the light branching member 4 may be integrally provided by a molding member. As a result, relative displacement of each member due to vibration can be suppressed, and defects such as distortion of the aerial image 6 due to displacement of each member can be suppressed. As the mold member, one that is transparent (has a high transmittance) to the light emitted from the light source 2 may be used, and for example, an acrylic resin, an epoxy resin, a silicone resin or the like may be used. As the mold member other than resin, an inorganic transparent material can be used, and glass or the like can be used.

(Operation and Effect of Embodiment)
As described above, in the vehicle display storage device 1 according to the present embodiment, the second retroreflective member 5 provided so as to block the incidence of external light parallel to the horizontal direction on the retroreflective member 3, The second retroreflective member 5 has, on the side of the light branching member 4, a retroreflective surface 5a that retroreflects incident light.

By providing the second retroreflective member 5, it is possible to block external light such as headlight light that is parallel to the horizontal direction, and it is possible to suppress the dazzling of the driver or pedestrian due to the returning light. Further, by providing the second retroreflective member 5, it is possible to retroreflect light incident from the light branching member 4 side and improve the light utilization efficiency. That is, according to the present invention, it is possible to realize the vehicular display device 1 that can suppress the returning light when external light such as a headlight is emitted and can also improve the brightness of the aerial image.

(Other embodiments)
In the above-described embodiment, the use of the semi-transmissive cover 7 attenuates the return light of the external light incident from the portion not covered by the second retroreflective member 5, but the return light may be changed by another method. Can be suppressed. In the vehicular display device 1a shown in FIG. 4, return light is suppressed by utilizing the characteristic of polarization. In the vehicle display device 1a, as the light branching member 4, a reflection type polarizing plate (reflection type) that reflects specific polarized light (here, S polarized light) and transmits polarized light orthogonal to the specific polarized light (here, P polarized light). Polarizing film) is used.

Further, a polarizing plate 8 capable of transmitting a specific polarized light is provided so as to cover the outside light incident side of the light branching member 4. In the present embodiment, a film-shaped polarizing film is used as the polarizing plate 8, and the polarizing film is attached and fixed to the inner peripheral surface of the cover 7.

A phase difference is provided between the polarizing plate 8 and the light branching member 4 so as to convert the electric field oscillation direction of the incident light into a direction of passing through the light branching member (here, a phase difference of π is given). The wave plate 9 is arranged. Here, as the outer wave plate 9, a first outer wave plate 9a attached and fixed on the polarizing plate 8 and a second outer wave plate 9b attached and fixed on the surface of the light branching member 4 on the cover 7 side. , Were used. The first and second outer wave plates 9a and 9b give a phase difference of (π/2) in the electric field oscillation direction of the incident light, and are so-called λ/4 plates. An inner wave plate 9c is arranged between the light branching member 4 and the retroreflective member 3. The inner wave plate 9c converts the electric field oscillation direction of the light retroreflected with respect to the external light into the direction reflected by the light branching member 4, and retroreflects the light from the light source 2. A phase difference is given so that the subsequent electric field vibration direction is converted into a direction that passes through the light branching portion 4. Here, as the inner wave plate 9c, a so-called λ/4 plate that gives a phase difference of (π/2) in the slow axis direction in the electric field oscillation direction of the incident light is used. When the phase of the component in the direction forming 45 degrees with respect to the polarization direction of the incident light is delayed by π/2, the polarization direction of the light rotates 90 degrees after being transmitted twice. Here, the inner wavelength plate 9c is attached and fixed on the surface (retroreflective surface) of the retroreflective member 3 so as to rotate the polarization direction of the light after retroreflection by 90 degrees.

In the vehicle display device 1 a, of the light incident as the external light, the P polarized light is cut by the polarizing plate 8 and only the S polarized light passes through the polarizing plate 8. The light that has passed through the polarizing plate 8 passes through the first and second outer wave plates 9 a and 9 b, is converted into P-polarized light, and passes through the light branching member 4. The light transmitted through the light branching member 4 is retroreflected by the retroreflective member 3, but at this time, it passes through the inner wave plate 9c provided on the retroreflective member 2 twice and is converted into S-polarized light. .. Since the light branching member 4 does not transmit S-polarized light, the light retroreflected by the retroreflective member 3 is reflected by the light branching member 4 and is not emitted to the outside. Even if a part of the light retroreflected by the retroreflective member 3 passes through the light branching member 4, the light passes through the first and second outer wave plates 9a and 9b and is P-polarized. Therefore, it is cut by the polarizing plate 8.

Further, in the vehicle display device 1a, a light source polarizing plate 2a capable of transmitting a specific polarized light (here, S polarized light) is provided between the light source 2 and the light branching member 4. The light source polarization plate 2a cuts the P polarized light of the light from the light source 2, the P polarized light passes through the light branching member 4, and is converted into S polarized light by the first and second outer wave plates 9a and 9b. It is possible to prevent the light from being transmitted to the outside through the polarizing plate 8.

Further, a second retroreflective member wavelength plate 5 c is provided between the second retroreflective member 5 and the light branching member 4. The second retroreflective member wavelength plate 5c converts the electric field oscillation direction of the light after retroreflection into the direction of passing through the light branching portion 4 with respect to external light, and with respect to the light from the light source 2. In other words, a phase difference is given so that the electric field vibration direction after retroreflection is converted into the direction in which the light branching portion 4 is reflected. Here, a so-called λ/4 plate that gives a phase difference of (π/2) in the slow axis direction in the electric field oscillation direction of the incident light is used as the second retroreflective member wavelength plate 5c. Here, the second retroreflective member wavelength plate 5c is attached and fixed onto the retroreflective surface 5a of the second retroreflective member 5. By providing the second retroreflective member wavelength plate 5c, the P-polarized light transmitted from the light source 2 side through the light branching member 4 passes through the first outer wavelength plate 9a and the second retroreflective member wavelength plate 5c, and becomes S. The polarized light enters the second retroreflective member 5, is retroreflected by the second retroreflective member 5, and then passes through the second retroreflective member wave plate 5c and the first outer wave plate 9a again to become P-polarized light. , Passes through the light branching member 4 and returns to the light source 2 side. As described above, by providing the second retroreflective member wavelength plate 5c, the light retroreflected by the second retroreflective member 5 can be returned to the light source 2 side and reused to improve the brightness of the aerial image 6. it can.

In the vehicular display device 1a, it is possible to suppress the returning light of the external light without coloring or coating the cover 7 to reduce the transmittance of the visible light. Therefore, it is possible to increase the visible light transmittance of the cover 7 and further improve the brightness of the aerial image 6 while suppressing the return light of the external light.

The vehicle display device 1b shown in FIG. 5 is the same as the vehicle display device 1 of FIG. 1, except that the light from the retroreflective member 3 or the second retroreflective member 5 is provided to each of the retroreflective member 3 and the second retroreflective member 5. The entrance/exit angle limiting members 3a and 5d for restricting the entrance/exit directions are provided.

As the entrance/exit angle limiting members 3a and 5d, a louver film generally used as a peep prevention film or the like can be used. As the louver film, for example, a film having a large number of linear grooves (louvers) formed in parallel can be used.

By limiting the entrance and exit angles of light of the retroreflective member 3 and the second retroreflective member 5 by using the entrance and exit angle limiting members 3a and 5d, unnecessary lights are cut by the entrance and exit angle limiting members 3a and 5d. Therefore, it is possible to further suppress return light when external light is incident from a portion not covered with the second retroreflective member 5.

Although the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the spirit of the invention.

For example, although the case where the vehicle display device 1 is provided on the back door 12 of the vehicle 10 has been described in the above embodiment, the installation position of the vehicle display device 1 is not limited to this.

Further, the above-described embodiments and examples do not limit the invention according to the claims. In addition, it should be noted that not all combinations of the features described in the embodiments and examples are essential to the means for solving the problems of the invention.

1 Vehicle Display Device 2 Light Source 2a Light Source Polarizing Plate 3 Retro-Reflecting Member 3a Entry/Exiting Angle Limiting Member 4 Light Dividing Member 5 Second Retro-Reflecting Member 5a Retro-Reflecting Surface 5b Light-Shielding Layer 5c Second Retro-Reflecting Member Wave Plate 5d Entry Emitting angle limiting member 6 Aerial image 7 Cover 8 Polarizing plate 9 Outer wave plate 9a First outer wave plate 9b Second outer wave plate 9c Inner wave plate 10 Vehicle 11 Vehicle body

Claims (8)

A light source,
A retroreflective member that is disposed below the light source and that retroreflects incident light,
A light branching member that reflects at least a part of the light from the light source and emits the light to the retroreflective member, and transmits at least a part of the light that is retroreflected and incident on the retroreflective member,
Light that is retroreflected by the retroreflective member and transmitted through the light branching member is configured to form an aerial image that is an image of the light source in the air,
A second retroreflective member provided so as to block the incidence of external light parallel to the horizontal direction on the retroreflective member,
The second retroreflective member has, on the light branching member side, a retroreflective surface that retroreflects incident light.
Vehicle display device. The light source has a diffuser capable of diffusing the return light that is retroreflected by the retroreflective surface of the second retroreflective member and returned to the light source, and emits the light to the light branching member again.
The vehicle display device according to claim 1. The second retroreflective member has a light-shielding layer capable of shielding incident external light on the incident side of external light.
The vehicle display device according to claim 1. A semi-transparent cover that is provided so as to cover the surface of the light branching member on the side of the aerial image and that transmits a part of the incident visible light is provided.
The vehicle display device according to any one of claims 1 to 3. The light branching member comprises a reflective polarizing plate that reflects a specific polarized light and transmits a polarized light orthogonal to the specific polarized light,
A polarizing plate that is arranged so as to cover the incident side of external light of the light branching member and that can transmit the specific polarized light,
Outer wave plates that are respectively disposed between the polarizing plate and the light branching member, and that give a phase difference so as to convert the electric field oscillation direction of incident light into a direction that transmits the light branching member,
It is arranged between the light branching member and the retroreflective member, and converts the electric field oscillation direction of the retroreflected light with respect to external light to the direction reflected by the light branching member, and For light from the light source, an inner wave plate that gives a phase difference so that the electric field vibration direction after retroreflection is converted to a direction that transmits the light branching portion,
The vehicle display device according to any one of claims 1 to 4. A light source polarizing plate that is disposed between the light source and the light branching member and is capable of transmitting the specific polarized light,
It is arranged between the second retroreflective member and the light branching member, and converts the electric field oscillation direction of the light after retroreflection into the direction of passing through the light branching member with respect to external light, and A second retroreflective member wave plate that imparts a phase difference to the light from the light source so that the electric field oscillation direction after retroreflection is converted to the direction in which the light branching member is reflected.
The vehicle display device according to claim 5. The retroreflective member and the second retroreflective member are respectively provided with an entrance/exit angle limiting member that restricts an incoming/outgoing direction of light in the retroreflective member or the second retroreflective member.
The vehicle display device according to any one of claims 1 to 6. It is attached to a vehicle body of a vehicle and is configured to form an image of the light source outside the vehicle body,
The vehicle display device according to any one of claims 1 to 7.

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