JP6683149B2 - Head-up display device - Google Patents

Description

  The present invention relates to a head-up display device (hereinafter abbreviated as HUD device) mounted on a moving body.

  Conventionally, a HUD device mounted on a moving body is known. The HUD device disclosed in Patent Document 1 has a plurality of display devices that emit display light in a polarized state in respective predetermined directions. These display devices project display light toward a windshield as a projection member to display virtual images.

Japanese Patent No. 5714125

  However, Patent Document 1 does not disclose or suggest the relationship in which the polarization direction of the display light from each display should be set at the time of passing through the optical aperture. In this regard, the present inventors have made earnest studies and found that the following problems occur when the polarization directions of the display lights are different from each other.

  The display light that has passed through the optical aperture is obliquely incident on the projection member and is reflected to form a virtual image. According to the Fresnel equation, the reflectance of the p-polarized component and that of the s-polarized component differ during this reflection. Therefore, the polarization direction of the incident display light affects the amount of reflected light after reflection and also the polarization direction after reflection in relation to the incident surface with respect to the projection member.

  If the occupant does not wear polarized sunglasses and is, for example, the naked eye, the polarization direction after reflection does not affect the brightness of the visible virtual image, and the virtual image is visible with the brightness depending on the amount of reflected light described above. Can be done. In a configuration in which a plurality of virtual images are displayed on a plurality of display devices, the plurality of virtual images are displayed with a predetermined brightness balance.

  On the other hand, when the occupant wears polarized sunglasses, due to the polarization effect of the polarized sunglasses, only the light in a specific polarization direction of the display light reflected by the projection member is transmitted and can be visually recognized. Become. Therefore, the brightness of the visually recognized virtual image depends not only on the amount of reflected light but also on the polarization direction after reflection. Here, if the polarization directions of the respective display lights from the respective display devices passing through the optical apertures are different from each other, the polarization directions after the reflection by the projection member are also necessarily different from each other. Therefore, with respect to each display light from each display, a difference occurs in the transmittance of the polarized sunglasses, and a plurality of virtual images are displayed with a brightness balance different from that of the naked eye.

  As an example, with the intention of displaying multiple virtual images with the same brightness, even if the multiple virtual images are viewed with the same brightness in the case of the naked eye, the occupant happens to wear polarized sunglasses. Then, a plurality of virtual images have different brightness, and it is visually recognized that only a specific virtual image is emphasized, which is not what was intended.

  As another example, with the intent of displaying a plurality of virtual images with different brightness at a predetermined ratio, even if the naked eye is visually recognized at different brightness at a predetermined ratio, If the occupant happens to wear polarized sunglasses, the predetermined ratio will be impaired, and it will not be as intended.

  The present invention has been made in view of the problems described above, and an object thereof is to provide a relative balance of brightness among a plurality of virtual image displays even when viewed by a passenger wearing polarized sunglasses. It is to provide a HUD device that is not easily damaged.

One of the disclosed invention is mounted on a mobile body (1), by using the reflection of the projection member (3), viewable virtual image by the occupant of the mobile (VIa, VIb) head-up display for displaying a plurality of A device,
A plurality of display devices (10, 20, 210, 220, 310, 320) that emit display light for displaying a virtual image in a state where they are polarized in respective predetermined directions, and form optical paths (OPa, OPb) by the display light. , 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common for a plurality of display devices, is optically opened, and allows each display light from each display device to pass toward a projection member,
A reflecting mirror (30, 40, 240, 340, 440, 530, 540, 630, 640, 730, 740) arranged on at least one of the optical paths and reflecting the display light from the display device corresponding to the optical path. ) And ,
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture ,
As the reflecting mirror in each optical path, only the common reflecting mirror shared between the respective optical paths corresponding to each display is provided,
The polarization directions of the respective display lights are aligned with each other immediately before entering the common reflecting mirror .
In addition, another one of the disclosed inventions is mounted on a moving body (1) and displays a plurality of virtual images (VIa, VIb) visible to an occupant of the moving body by using reflection on a projection member (3). A head-up display device for
A plurality of display devices (10, 20, 210, 220, 310, 320) that emit display light for displaying a virtual image in a state where they are polarized in respective predetermined directions, and form optical paths (OPa, OPb) by the display light. , 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common for a plurality of display devices, is optically opened, and allows each display light from each display device to pass toward a projection member,
A reflecting mirror (30, 40, 240, 340, 440, 530, 540, 630, 640, 730, 740) arranged on at least one of the optical paths and reflecting the display light from the display device corresponding to the optical path. ) And,
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture,
A plurality of reflecting mirrors are provided,
Each of the reflection mirrors has one tilted polarization arrangement reflection mirror arranged so that the display light of the corresponding optical path is incident on the reflection mirror in a polarization direction inclined at a predetermined angle with respect to the incident surface of the reflection mirror. Including the above,
Each optical path includes both an even number reflection optical path in which the number of reflections by the inclined polarization arrangement reflecting mirror is an even number, and an odd number of times reflection optical path in which the number of reflections by the inclined polarization arrangement reflection mirror is an odd number,
The polarization direction of the display light immediately before entering the first inclined polarization arrangement reflecting mirror in the even-numbered reflection optical path and the polarization direction of the display light immediately before entering the first inclination polarization arrangement reflecting mirror in the odd-numbered reflection optical path are respectively In the first tilted polarized light arrangement reflecting mirror, and the orthogonal axis (OA) orthogonal to the plane of incidence is an object line, and they are line-symmetrical to each other.
In addition, another one of the disclosed inventions is mounted on a moving body (1) and displays a plurality of virtual images (VIa, VIb) visible to an occupant of the moving body by using reflection on a projection member (3). A head-up display device for
A plurality of display devices (10, 20, 210, 220, 310, 320) that emit display light for displaying a virtual image in a state where they are polarized in respective predetermined directions, and form optical paths (OPa, OPb) by the display light. , 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common for a plurality of display devices, is optically opened, and allows each display light from each display device to pass toward a projection member;
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture,
A display corresponding to a specific optical path is arranged on at least one specific optical path of the respective optical paths corresponding to the respective display devices so that the polarization directions of the respective display lights are matched immediately before entering the optical aperture. A retardation plate (350) for rotating the polarization direction of the display light from the container is further provided.
Further, another one of the disclosed inventions is mounted on a moving body (1) and uses a reflection on a projection member (3) to display a plurality of virtual images (VIa, VIb) visible to an occupant of the moving body. A head-up display device for
A plurality of display devices (10, 20, 210, 220, 310, 320) that emit display light for displaying a virtual image in a state of being polarized in respective predetermined directions and configure optical paths (OPa, OPb) by the display light. , 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common for a plurality of display devices, is optically opened, and allows each display light from each display device to pass toward a projection member;
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture,
The display from the corresponding display is arranged on at least one specific optical path of the respective optical paths corresponding to the respective display devices so that the polarization directions of the respective display lights match immediately before entering the optical aperture. A polarizer (452) that changes the polarization direction of light is further included.

  According to such an invention, the polarization directions of the display lights from the respective displays are aligned with each other immediately before entering the optical aperture. By adjusting the polarization directions in this way, the ratios of the p-polarized component and the s-polarized component can be made close to each other when each display light is incident on the projection member. Therefore, in reflection on the projection member, a difference in reflectance between the display lights is unlikely to occur, and the polarization directions after reflection can be close to each other. Therefore, the transmittance of the polarized sunglasses that can be worn by the occupant is unlikely to differ from each display light, so that it is possible to prevent the polarized sunglasses from breaking the relative balance of the brightness between the plurality of virtual image displays. it can.

  Therefore, even if the occupant visually recognizes a plurality of virtual images while wearing polarized sunglasses, the brightness balance between the virtual images is close to the brightness balance that can be visually recognized by the naked eye and the like. It is possible to realize a HUD device in which the relative balance of brightness between displays is not easily impaired.

  It should be noted that the reference numerals in parentheses are only intended to exemplify the corresponding configurations in the embodiments to be described later in order to facilitate understanding of the description, and are not intended to limit the content of the invention.

It is a figure which shows the mounting state in the vehicle of the HUD apparatus in 1st Embodiment. It is a figure which shows schematic structure of the HUD apparatus in 1st Embodiment. It is a figure which shows the laser display in 1st Embodiment. It is a figure which shows the liquid crystal display in 1st Embodiment. It is a figure which shows the display screen of the liquid crystal display in 1st Embodiment. It is a figure which expands the VI section of FIG. It is the VII-VII sectional view taken on the line of FIG. It is a figure which shows the polarization direction of the display light by a laser display and the display light by a liquid crystal display in 1st Embodiment. It is a figure corresponding to FIG. 2 in 2nd Embodiment. It is a figure which shows the polarization direction of the display light by a laser display, and the display light by a liquid crystal display in 2nd Embodiment. It is a figure corresponding to FIG. 2 in 3rd Embodiment. It is a figure which shows the polarization direction of the display light by a laser display and the display light by a liquid crystal display in 3rd Embodiment. It is a figure corresponding to FIG. 2 in 4th Embodiment. It is a figure which shows the polarization direction of the display light by a laser display, and the display light by a liquid crystal display in 4th Embodiment. It is a figure corresponding to FIG. 2 in 5th Embodiment. It is a figure which shows the polarization direction of the display light by a laser display, and the display light by a liquid crystal display in 5th Embodiment. It is a figure corresponding to FIG. 2 in 6th Embodiment. It is a figure which shows the polarization direction of the display light by a laser display, and the display light by a liquid crystal display in 6th Embodiment. It is a figure corresponding to FIG. 2 in 7th Embodiment. It is a figure which shows the polarization direction of the display light by a laser display and the display light by a liquid crystal display in 7th Embodiment.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. It should be noted that, in each of the embodiments, the corresponding components may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each embodiment, the configurations of the other embodiments described above can be applied to the other part of the configuration. In addition, not only the combination of the configurations explicitly described in the description of each embodiment, but if there is no particular problem in the combination, the configurations of the plurality of embodiments can be partially combined even if not explicitly stated. .

(First embodiment)
As shown in FIG. 1, the HUD device 100 according to the first embodiment of the present invention is mounted on a vehicle 1 which is a kind of a mobile body, and is housed in an instrument panel 2. The HUD device 100 projects an image on the windshield 3 as a projection member of the vehicle 1. As a result, the HUD device 100 displays the virtual images VIa and VIb that can be visually recognized by the occupant of the vehicle 1. That is, when the display light of the image projected on the windshield 3 reaches the visual recognition area EB set inside the vehicle 1, the occupant whose eyepoint EP is located in the visual recognition area EB is a virtual image of the display light. Perceived as VIa and VIb. Then, the occupant can recognize various information displayed as the virtual images VIa and VIb. Examples of various information displayed as the virtual images VIa and VIb include vehicle state values such as vehicle speed and remaining fuel amount, and vehicle information such as road information and visibility assistance information.

  Hereinafter, the vehicle upper side, the vehicle lower side, the vehicle vertical direction, the vehicle front side, the vehicle rear side, the vehicle front-rear direction, the vehicle left-right direction, and the like are defined with reference to the vehicle 1 on the horizontal plane HP.

  The windshield 3 of the vehicle 1 is formed of, for example, glass or synthetic resin in a translucent plate shape, and is arranged above the instrument panel 2 in the vehicle. The windshield 3 forms a projection surface 3a on which display light is projected in a smooth concave shape or a flat shape. The projection surface 3a faces the lower side of the vehicle and the rear side of the vehicle.

  The HUD device 100 that uses the reflection of the display light on the windshield 3 can display a plurality of virtual images VIa and VIb at the same time, particularly in this embodiment. The combination of information displayed by the plurality of virtual images VIa and VIb is set appropriately. An occupant seated in the seat of the vehicle 1 and facing the front of the vehicle, particularly a driver, visually recognizes the foreground including roads and road signs through the windshield 3, and superimposes a plurality of virtual images VIa and VIb on the foreground. It can be seen in the state.

  The visual recognition area EB is a space area in which the virtual images VIa and VIb displayed by the HUD device 100 are visually recognizable so as to meet the standard, and is also called an eye box. Typically, the visual recognition area EB is set so as to overlap the eye lip set in the vehicle 1. The eye lip is set based on the eye range that statistically represents the distribution of the occupant's eye points EP.

  A specific configuration of the HUD device 100 will be described below with reference to FIGS. As shown in FIG. 2, the HUD device 100 includes a plurality of display devices 10 and 20, a plurality of reflecting mirrors 30 and 40, and the like. The indicators 10 and 20 and the reflecting mirrors 30 and 40 are housed in the housing 6 of the HUD device 100.

  The housing 6 is formed of, for example, a synthetic resin in a hollow box shape having a light shielding property. An optical opening 7 that optically opens is provided in the housing 6 at a position corresponding to an opening window formed in the upper surface 2 a of the instrument panel 2.

  The optical opening 7 is covered with a dustproof cover 7a, for example, so as to cover the entire surface thereof. The dustproof cover 7a of the present embodiment is a light-transmitting thin plate-like light-transmitting plate made of, for example, synthetic resin.

  In the HUD device 100 of the present embodiment, a total of two indicators, that is, the laser indicator 10 and the liquid crystal indicator 20, are provided as a plurality of indicators.

  As shown in FIG. 3, the laser display 10 includes a plurality of laser oscillators 11a to 11c, a plurality of collimator lenses 12a to 12c, a folding mirror 13a, a plurality of dichroic mirrors 13b and 13c, a scanning mirror 16, and a display screen 17. Have In this embodiment, three laser oscillators 11a to 11c, three collimator lenses 12a to 12c, and two dichroic mirrors 13b and 13c are provided.

  A semiconductor laser, for example, is used for the three laser oscillators 11a to 11c, and substantially linearly polarized laser light fluxes having different wavelengths are oscillated. Specifically, the laser oscillator 11a oscillates a green laser beam having a peak wavelength in the range of 490 to 530 nm, preferably 515 nm. The laser oscillator 11b oscillates a blue laser beam having a peak wavelength in the range of 430 to 470 nm, preferably 450 nm. The laser oscillator 11c oscillates a red laser beam having a peak wavelength in the range of 600 to 650 nm, preferably 640 nm. The laser light fluxes oscillated from the laser oscillators 11a to 11c enter the corresponding collimator lenses 12a to 12c, respectively.

  The three collimator lenses 12a to 12c are arranged at a predetermined interval in the traveling direction of each laser beam with respect to the corresponding laser oscillators 11a to 11c. Each of the collimator lenses 12a to 12c refracts the laser light flux of the corresponding color to substantially collimate the laser light flux.

  The folding mirror 13a is arranged at a predetermined distance from the collimator lens 12a in the traveling direction of the laser beam, and reflects the laser beam transmitted through the collimator lens 12a.

  The two dichroic mirrors 13b and 13c are arranged with respect to the corresponding collimator lenses 12b and 12c with a predetermined space in the traveling direction of each laser beam. Each of the dichroic mirrors 13b and 13c reflects a laser light flux having a specific wavelength among the laser light fluxes transmitted through the corresponding collimator lenses 12b and 12c, and transmits other laser light fluxes. Specifically, the dichroic mirror 13b corresponding to the collimator lens 12b reflects the blue laser beam and transmits the green laser beam. The dichroic mirror 13c corresponding to the collimator lens 12c reflects the red laser beam and transmits the green and blue laser beams.

  Here, the dichroic mirror 13b is arranged at a predetermined interval in the traveling direction of the green laser beam after being reflected by the folding mirror 13a. A dichroic mirror 13c is arranged at a predetermined interval in the traveling direction of the blue laser beam after being reflected by the dichroic mirror 13b. With these arrangements, the green laser light flux after being reflected by the folding mirror 13a passes through the dichroic mirror 13b and is superimposed on the blue laser light flux after being reflected by the dichroic mirror 13b. Further, the green laser beam and the blue laser beam pass through the dichroic mirror 13c, and the red color after being reflected by the dichroic mirror 13c is also superimposed on the laser beam.

  The laser oscillators 11a to 11c are electrically connected to the controller 15. Each of the laser oscillators 11a to 11c oscillates a laser beam according to an electric signal from the controller 15. Then, it is possible to reproduce various colors by additively mixing the laser beams of three colors oscillated from the laser oscillators 11a to 11c. In this way, the laser beams having different wavelengths are emitted toward the scanning mirror 16 in a superposed state.

  The scanning mirror 16 is a MEMS mirror configured to be capable of temporally scanning a laser beam using a micro electro mechanical system (MEMS). On the surface of the scanning mirror 16 which faces the dichroic mirrors 13b to 13c at a predetermined interval, a reflecting surface 16a is formed by vapor deposition of a metal film such as aluminum. The reflecting surface 16a is rotatable about two rotation axes AX and AY arranged substantially orthogonally along the reflecting surface 16a.

  Such a scanning mirror 16 is electrically connected to the controller, and can rotate the scanning signal to change the direction of the reflecting surface 16a. As the scanning mirror 16 is controlled by the controller 15 in this manner, the scanning mirror 16 and the laser oscillators 11a to 11c are interlocked with each other, and the deflection point LT, which is the incident point of the laser light flux on the reflecting surface 16a, is used as a starting point and temporally. It is possible to deflect the projection direction of the laser beam. The laser light flux scanned by the scanning mirror 16 by the deflection at the deflection point LT is incident on the display screen 17.

  The display screen 17 is a reflection type screen formed in a mirror array by depositing a metal film such as aluminum on the surface of a base material made of synthetic resin or glass. It can also be adopted. The display screen 17 has a plurality of optical curved surfaces arranged in a lattice on the side facing the scanning mirror 16.

  An image is drawn in the scanning area SA of the display screen 17 by the laser light flux scanned by the scanning mirror 16. Specifically, the laser light flux is sequentially scanned along the plurality of scanning lines SL under the control of the controller 15. As a result, an image is drawn by intermittently irradiating the laser beam with pulses while moving the position where the laser beam is incident in the scanning area SA. An image drawn by laser projection on the scanning area SA is, for example, 60 frames per second as an image having 480 pixels in the xs direction along the scanning line SL and 240 pixels in the ys direction substantially perpendicular to the scanning line SL. . Note that the optical curved surface is not shown in FIG.

  Here, the laser light flux forming each pixel is emitted from the display screen 17 as display light while expanding the divergence angle of the light flux by reflection on the optical curved surface formed in a concave shape or a convex shape. In this way, the laser display 10 emits the display light for displaying the virtual image VIa out of the plurality of virtual images VIa and VIb from the scanning area SA of the display screen 17. The display light is emitted from the display screen 17 in a state of being polarized in a predetermined direction, specifically, as linearly polarized light based on the properties of the laser oscillators 11a to 11c.

  The display light emitted from the display screen 17 of the laser display 10 causes the virtual image VIa to be displayed as described above. In the present embodiment, the xs direction corresponds to the left-right direction of the vehicle 1 on the horizontal plane HP when the virtual image VIa is displayed. Therefore, in this embodiment, the direction corresponding to the xs direction is defined as the display horizontal direction. Similarly, the ys direction corresponds to the vertical direction of the vehicle 1 on the horizontal plane HP when the virtual image VIa is displayed. Therefore, in this embodiment, the direction corresponding to the ys direction is defined as the display vertical direction.

  In the present embodiment, as shown in FIG. 2, the display screen 17 is oriented approximately above the vehicle in a posture in which the horizontal display direction is aligned with the horizontal direction of the vehicle. The laser display 10 emits display light in a state where the display light is polarized in the horizontal direction of the display as a predetermined direction.

  The liquid crystal display 20 is arranged in the housing 6 above the laser display 10 in the vehicle. As shown in FIG. 4, the liquid crystal display 20 has a backlight portion 21 and a liquid crystal panel 25, and is configured to be housed in a box-shaped casing 20a (see FIG. 5), for example. The backlight unit 21 has a light source 22, a condenser lens 23, and a field lens 24.

  The light source 22 is composed of, for example, an array of a plurality of light emitting elements 22a. The light emitting element 22a in the present embodiment is a light emitting diode element arranged on the light source circuit board 22b and connected to a power source. Each light emitting element 22a emits light with a light emission amount according to the amount of current when energized. More specifically, in each of the light emitting elements 22a, for example, a blue light emitting diode is covered with a fluorescent material to realize pseudo white light emission.

  The condenser lens 23 and the field lens 24 are arranged between the light source 22 and the liquid crystal panel 25. The condenser lens 23 is made of, for example, a constituent resin, glass, or the like and has a light-transmitting property. Particularly, the condenser lens 23 of the present embodiment is a lens array in which a plurality of convex lens elements are arranged according to the number and arrangement of light emitting elements. The condenser lens 23 collects the light incident from the light source side and emits it to the field lens side.

  The field lens 24 is disposed between the condenser lens 23 and the liquid crystal panel 25, and is made of, for example, synthetic resin or glass and has a light-transmitting property. In particular, the field lens 24 of the present embodiment further condenses and collimates the light incident from the condenser lens 23 side, and emits the light toward the liquid crystal panel 25 side.

  In addition to the above-described configuration, various configurations can be adopted as the configuration of the backlight unit 21.

  The liquid crystal panel 25 of the present embodiment is a liquid crystal panel using thin film transistors (TFTs), and is, for example, an active matrix liquid crystal panel formed of a plurality of liquid crystal pixels 27 arranged in two directions. .

  Specifically, as shown in FIG. 5, the liquid crystal panel 25 has a rectangular shape having a longitudinal direction and a lateral direction. As shown in an enlarged view in FIG. 6, the liquid crystal pixels 27 are arranged in the longitudinal direction and the lateral direction, so that the display screen 26 that is exposed to the outside and emits an image as display light also has a rectangular shape. . Each liquid crystal pixel 27 is provided with a transmissive portion 25d provided so as to penetrate in the normal direction of the display screen 26, and a wiring portion 25e formed so as to surround the transmissive portion 25d.

  As shown in FIG. 7, the liquid crystal panel 25 has a flat plate shape by being formed by laminating a pair of polarizing plates 25a and 25b and a liquid crystal layer 25c sandwiched between the pair of polarizing plates 25a and 25b. ing. Each of the polarizing plates 25a and 25b has a transmission axis and a light blocking axis orthogonal to the transmission axis. Each of the polarizing plates 25a and 25b has a property of transmitting light polarized in the direction of the transmission axis and absorbing light polarized in the direction of the light-shielding axis. Are arranged with their directions orthogonal to each other. By applying a voltage to each liquid crystal pixel 27, the liquid crystal layer 25c can rotate the polarization direction of light passing through the liquid crystal layer according to the applied voltage. By rotating the polarization direction, the ratio of light transmitted through the polarizing plate 25b on the display screen 26 side, that is, the transmittance can be changed at any time.

  Therefore, the liquid crystal panel 25 controls the transmittance of each liquid crystal pixel 27 with respect to the incidence of light from the backlight unit 21. That is, the liquid crystal panel 25 of the liquid crystal display 20 forms an image using illumination from the backlight unit 21 side, and can be emitted as display light for displaying the virtual image VIb of the plurality of virtual images VIa and VIb. ing. The display light is emitted from the display screen 26 in the state of being polarized in a predetermined direction according to the arrangement of the transmission axis of the polarizing plate 25b on the display screen 26 side, specifically, as linearly polarized light.

  The virtual light VIb is displayed as described above by the display light emitted from the display screen 26 of each liquid crystal display 20. In the present embodiment, the longitudinal direction of the display screen 26 of each liquid crystal display 20 corresponds to the lateral direction of the vehicle 1 on the horizontal plane HP when the virtual image VIb is displayed. Therefore, in this embodiment, the direction corresponding to the longitudinal direction of the display screen 26 is defined as the display horizontal direction. Similarly, the lateral direction of the display screen 26 of each liquid crystal display 20 corresponds to the vertical direction of the vehicle 1 on the horizontal plane HP when the virtual image VIb is displayed. Therefore, in this embodiment, the direction corresponding to the lateral direction of the display screen 26 is defined as the display vertical direction.

  In the present embodiment, as shown in FIG. 2, the display screen 26 of the liquid crystal display 20 faces the front of the vehicle in a posture in which the horizontal display direction is aligned with the horizontal direction of the vehicle. The liquid crystal display 20 emits the display light in a state in which the display light is polarized in the display horizontal direction as a predetermined direction.

  Optical paths OPa and OPb for display light from each liquid crystal display 20 to the windshield 3 via the optical opening 7 are individually configured for each display 10, 20. The reflecting mirror 30 and the reflecting mirror 40 are arranged on the optical path OPa for the laser display 10. A reflecting mirror 40 is arranged on the optical path OPb for the liquid crystal display 20. That is, the reflecting mirror 40 is used between the optical paths OPa and OPb.

  The reflecting mirror 30 is formed by depositing a metal film such as aluminum as the reflecting surface 31 on the surface of a base material made of, for example, synthetic resin or glass. The reflecting surface 31 is formed into a smooth flat surface. The reflecting surface 31 does not incline in the vehicle left-right direction, faces the vehicle downward and the vehicle front, and faces the display screen 17 of the laser display 10 and the reflecting mirror 40, respectively.

  Display light from the laser display 10 is incident on the reflecting mirror 30 in a polarization direction PDa along a direction perpendicular to the incident surface Pa1 (see also FIG. 8) of the reflecting mirror 30. More specifically, the display light from the laser display 10 travels upward along the vehicle in the vehicle up-down direction and is incident on the reflecting mirror 30. Therefore, the reflecting surface 31 of the reflecting mirror 30 and the incident surface Pa1 that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). .

  On the other hand, since the display light from the laser display 10 is incident on the reflecting mirror 30 in the polarization direction PDa along the vehicle left-right direction, the polarization direction PDa is along the direction perpendicular to the incident surface Pa1. (More specifically, it is s-polarized light).

  Thus, in the optical path OPa, the reflecting mirror 30 specularly reflects the display light incident from the laser display device 10 toward the reflecting mirror 40.

  The reflecting mirror 40 is formed, for example, by vapor-depositing a metal film such as aluminum on the surface of a base material made of synthetic resin or glass as the reflecting surface 41. The reflecting mirror 40 is a concave mirror, and the reflecting surface 41 is formed in a smooth concave shape by bending the center of the reflecting mirror 40 into a concave shape. In particular, the reflecting surface 41 of this embodiment is formed into a free-form surface corresponding to the shape of the windshield 3. The reflecting surface 41 faces the upper side of the vehicle and the rear side of the vehicle, and faces the reflecting mirror 30 and each of the windshields 3 through the optical openings 7.

  The display light reflected by the reflecting mirror 30 in the optical path OPa enters the reflecting mirror 40 in the polarization direction PDa along the direction perpendicular to the incident surface Pa2 (see also FIG. 8) of the reflecting mirror 40. More specifically, the display light from the reflecting mirror 30 travels forward along the vehicle front-rear direction and enters the reflecting mirror 40. Therefore, the reflecting surface 41 of the reflecting mirror 40 and the incident surface Pa2 that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). . Supplementally, since the reflecting surface 41 of the reflecting mirror 40 is concave, the direction of reflection is slightly different depending on the incident position of the display light, but here, the emission intensity is highest from the center of the scanning area SA in the laser display 10. The display light emitted in the direction may be defined as a reference ray, and the incident surface Pa2 may be defined from the incident point of the reference ray and the reflection mirror 40. In this embodiment, the path of the reference light ray is defined as the optical axis of the optical path OPa.

  On the other hand, since the display light from the reflecting mirror 30 is incident on the reflecting mirror 40 in the polarization direction PDa along the vehicle left-right direction, the polarization direction PDa is along the direction perpendicular to the incident surface Pa2 ( More specifically, it is s-polarized light).

  Thus, in the optical path OPa, the reflecting mirror 40 specularly reflects the display light incident from the reflecting mirror 30 toward the optical opening 7 while enlarging the virtual image VIa.

  At the same time, the reflective surface 41 faces each of the liquid crystal display 20 and the windshield 3 through the optical opening 7. In the optical path OPb, the display light from the liquid crystal display 20 is incident on the reflecting mirror 40 in the polarization direction PDb along the direction perpendicular to the incident surface Pb (see also FIG. 8) of the reflecting mirror 40. More specifically, the display light from the liquid crystal display 20 travels along the vehicle front-rear direction to the front of the vehicle and is incident on the reflecting mirror 40. Therefore, the reflecting surface 41 of the reflecting mirror 40 and the incident surface Pb that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). . Supplementally, similar to the case of the optical path OPa, the display light emitted from the center of the display screen 26 in the liquid crystal display 20 in the direction having the highest emission intensity is defined as a reference light beam, and the reference light beam and its reflection mirror 40 are defined. The incident surface Pb may be defined from the incident position on. In the present embodiment, the path of the reference light ray is defined as the optical axis of the optical path OPb.

  On the other hand, since the display light from the liquid crystal display 20 is incident on the reflecting mirror 30 in the polarization direction PDb along the vehicle left-right direction, the polarization direction PDb is along the direction perpendicular to the incident surface Pb. (More specifically, it is s-polarized light).

  In this way, in the optical path OPb, the reflecting mirror 40 specularly reflects the display light incident from the liquid crystal display 20 toward the optical opening 7 while enlarging the virtual image VIb.

  Therefore, the reflecting mirror 40 is a common reflecting mirror shared between the optical paths OPa and OPb. Although the display light on the optical path OPa and the display light on the optical path OPb are different in the angle of incidence on the reflecting mirror 40, they are incident on the reflecting mirror 40 so that the incident surfaces Pa2 and Pb are defined in a common direction. It has become.

  The above-mentioned optical opening 7 is commonly provided for the plurality of displays 10 and 20. The optical aperture 7 allows most of the display lights from the respective displays 10, 20 to pass through to the windshield 3, that is, most of the display light on the optical path OPa and the display light on the optical path OPb. Each display light travels to the upper side of the vehicle along the vertical direction of the vehicle.

  Immediately before the optical aperture 7 enters the dust-proof cover 7a, the polarization direction PDa of the display light from the laser display 10 forming the optical path OPa and the liquid crystal display 20 forming the optical path OPb. The polarization direction PDb of the display light from is aligned with each other. In particular, in the present embodiment, immediately before the optical opening 7 enters the dust-proof cover 7a, the polarization direction PDa of the display light on the optical path OPa and the polarization direction PDb of the display light on the optical path OPb are along the same direction. There is.

  In order to explain the polarization directions PDa and PDb in more detail, on the virtual plane perpendicular to the traveling direction of the reference ray in each of the optical paths OPa and OPb, the direction corresponding to the display horizontal direction is set as the reference azimuth, and the observer (occupant) side Defines the azimuth angle when a positive direction is taken in the clockwise direction when viewed. Under these definitions, as shown in FIG. 8 specifically, immediately after the laser display 10 is emitted, the polarization direction PDa of the display light from the laser display 10 on the optical path OPa is the direction corresponding to the horizontal display direction, That is, the azimuth angle was 0 degree. Even immediately before the optical opening 7 enters the dust-proof cover 7a, the polarization direction PDa of the display light on the optical path OPa is the direction corresponding to the horizontal display direction and the azimuth angle is 0 degree. Similarly, immediately after the liquid crystal display 20 is emitted, the polarization direction PDb of the display light from the liquid crystal display 20 on the optical path OPb is the direction corresponding to the horizontal display direction, and the azimuth angle is 0 degree. Immediately before the optical opening 7 is incident on the dustproof cover 7a, the polarization direction PDb of the display light on the optical path OPb is the direction corresponding to the horizontal display direction and the azimuth angle is 0 degree. Note that the polarization directions PDa and PDb in FIG. 8 are all shown as viewed from the observer side.

  That is, in the present embodiment, the polarization directions PDa and PDb of the respective display lights are aligned with each other immediately after the display devices 10 and 20 are emitted and immediately before the optical aperture 7 is incident on the dustproof cover 7a. .

  Each display light that has passed through the optical aperture 7 is reflected by the projection surface 3a of the windshield 3 as described above, and contributes to the display of the respective virtual images VIa and VIb. The dustproof cover 7a may be one that causes a slight phase difference in the display light, like a retardation plate. In this case, each display light can be converted into elliptically polarized light when passing through the retardation plate. In this embodiment, no element such as a polarizing plate that changes the polarization directions PDa and PDb is arranged between the dust shield 7a and the windshield 3.

Here, in the present embodiment, since the incident angle of the optical path OPa to the reflecting mirror 40 is larger than the incident angle of the optical path OPb to the reflecting mirror 40, the display light of the optical path OPa is larger than the display light of the optical path OPb. Will also be projected above the vehicle from the windshield. The virtual image VIa formed by the display light of the laser display 10 is visible above the vehicle than the virtual image VIb formed by the display light of the liquid crystal display 20. Further, since the optical path OPa is configured to be longer than the optical path OPb, the virtual image VIa is visually recognized farther than the virtual image VIb. When the occupant visually recognizes it with the naked eye, the brightness of the virtual image VIa is, for example, about 6,000 cd / m ² , the brightness of the virtual image VIb is, for example, about 13,000 cd / m ² , and the virtual image VIb is more than the virtual image VIa. Is also bright. However, the characteristic of the laser display 10 is that the virtual image VIa has a higher contrast than the virtual image VIb.

  Further, as shown in FIG. 2, the HUD device 100 is provided with a drive mechanism 43 that swings the reflecting mirror 40. The drive mechanism 43 drives the stepping motor to swing the reflecting mirror 40 around the rotation shaft 43a in response to an occupant operating an operation switch, for example. The rotating shaft 43a is arranged so as to extend in a direction along the vehicle left-right direction. By the swinging of the reflecting mirror 40, the image forming positions of the virtual images VIa and VIb are simultaneously moved up and down, and the positions can be adjusted to a position that is easily seen by the occupant. During such swinging, in the reflecting mirror 40, along the direction perpendicular to both the incident surface Pa2 defined by the display light on the optical path OPa and the incident surface Pb defined by the optical path OPb, and along the polarization directions PDa and PDb of the respective display lights. Since the rotation shaft 43a is extended, the relationship between the incident surfaces Pa2 and Pb and the polarization directions PDa and PDb is unlikely to change even when the optical axis swings.

(Action effect)
The operational effects of the first embodiment described above will be described below.

  According to the first embodiment, the polarization directions PDa and PDb of the display light from the respective display devices 10 and 20 are aligned with each other immediately before entering the optical aperture 7. By thus matching the polarization directions PDa and PDb, it is possible to bring the ratios of the p-polarized component and the s-polarized component close to each other when each display light enters the windshield 3 as the projection member. Therefore, in the reflection on the windshield 3, a difference in reflectance between the display lights is unlikely to occur, and the polarization directions PDa and PDb after reflection can be close to each other. Therefore, the transmittance of the polarized sunglasses that can be worn by the occupant is unlikely to differ from each display light, and thus the polarized sunglasses destroy the relative balance of brightness between the displays of the plurality of virtual images VIa and VIb. Can be suppressed.

  Therefore, even if the occupant visually recognizes the plurality of virtual images VIa and VIb while wearing polarized sunglasses, the brightness balance between the virtual images VIa and VIb is close to the brightness balance that can be visually recognized by the naked eye or the like. Therefore, it is possible to realize the HUD device 100 in which the relative balance of brightness is unlikely to be impaired between the displays of the plurality of virtual images VIa and VIb.

  Moreover, according to the first embodiment, the polarization directions PDa and PDb of the display light from the respective display devices 10 and 20 are along the same direction immediately before entering the optical aperture 7. Since the polarization directions PDa and PDb are along the same direction, it is possible to more reliably prevent the relative balance of brightness between the plurality of virtual images VIa and VIb from being impaired.

  Further, according to the first embodiment, the reflecting mirrors 30 and 40 that reflect the display light from the displays 10 and 20 are provided on at least one of the optical paths OPa and OPb. Since the optical paths OPa and OPb can be bent by providing the reflecting mirrors 30 and 40, the distance or the size at which the virtual images VIa and VIb are visually recognized is adjusted while the mountability of the HUD device 100 on the vehicle is improved. It becomes possible to do.

  Further, according to the first embodiment, the display light on the optical path OPa has the polarization direction PDa along the parallel direction or the vertical direction (all vertical directions in the present embodiment) with respect to the incident surfaces Pa1 and Pa2 of the reflecting mirrors 30 and 40. , Is incident on all the reflecting mirrors 30 and 40. At the same time, the display light on the optical path OPb enters the reflecting mirror 40 in the polarization direction PDb along the direction perpendicular to the incident surface Pb of the reflecting mirror 40. Since the polarization directions PDa and PDb of the respective display lights are not inclined with respect to the incident surfaces Pa1, Pa2 and Pb, it is possible to prevent the polarization directions from being reversed due to the reflection. Therefore, the polarization directions PDa and PDb can be easily adjusted, and the polarization directions PDa and PDb of the respective display lights can be accurately aligned immediately before entering the optical aperture 7. Therefore, it is possible to more reliably prevent the relative balance of brightness between the displays of the plurality of virtual images VIa and VIb from being impaired.

  Further, according to the first embodiment, as the reflecting mirror, the common reflecting mirror 40 that is shared between the respective optical paths OPa and OPb corresponding to the respective display devices 10 and 20 is provided. According to such a common reflecting mirror 40, it is possible to realize the optical paths OPa and OPb corresponding to the respective display devices 10 and 20 while improving the mountability of the HUD device 100 on the vehicle.

  Further, according to the first embodiment, the polarization directions PDa and PDb of the respective display lights are aligned with each other immediately after the emission of the respective display devices 10 and 20. By doing so, the polarization directions PDa and PDb of the respective display lights immediately before the light enters the optical aperture 7 without adding an element for converting the polarization directions PDa and PDb on the optical paths OPa and OPb, for example. Can be easily adjusted.

  Further, according to the first embodiment, the optical opening 7 is closed by the dust-proof cover 7a as a translucent plate that transmits each display light. According to such a configuration, after the polarization directions PDa and PDb of the display lights are aligned with each other, the display lights can be transmitted to the dustproof cover 7a and projected on the windshield 3, so that the brightness of the virtual images VIa and VIb can be reduced. It is possible to realize the HUD device 100 in which the relative balance of the brightness is not easily impaired between the displays of the plurality of virtual images VIa and VIb while maintaining the same.

(Second embodiment)
As shown in FIGS. 9 and 10, the second embodiment of the present invention is a modification of the first embodiment. The second embodiment will be described focusing on the points different from the first embodiment.

  In the HUD device 200 of the second embodiment, as in the first embodiment, a total of two indicators, a laser indicator 210 and a liquid crystal indicator 220, are provided as a plurality of indicators.

  However, the display screen of the laser display 210 faces the front of the vehicle in a posture in which the horizontal display direction is aligned with the horizontal direction of the vehicle. The laser display 10 emits the display light in a polarized state as a predetermined direction in a direction inclined with respect to the display horizontal direction (specifically, a direction with an azimuth angle of 45 degrees).

  On the other hand, the display screen 26 of the liquid crystal display 220 faces the front of the vehicle in a posture in which the horizontal display direction is aligned with the lateral direction of the vehicle. The liquid crystal display 220 is a state in which the display light is polarized in a direction that is tilted with respect to the horizontal display direction as a predetermined direction and is aligned with the laser display 210 (specifically, a direction with an azimuth angle of 45 degrees). It is supposed to be emitted in.

  In the second embodiment, the reflecting mirror 240 is arranged on the optical path OPa for the laser display 210. A reflecting mirror 240 is arranged on the optical path OPb for the liquid crystal display 220. That is, only one reflecting mirror 240 is provided, and the reflecting mirror 240 is used between both optical paths OPa and OPb.

  The reflecting mirror 240 has the same configuration as the reflecting mirror 40 of the first embodiment. However, the relationship between the reflecting mirror 240 and the display light on each of the optical paths OPa and OPb is different from that in the first embodiment.

  Regarding the optical path OPa, the reflection surface 41 faces each of the laser display 210 and the windshield 3 through the optical opening 7. In the optical path OPa, the display light from the laser display 210 enters the reflecting mirror 240 in the polarization direction PDa inclined with respect to the incident surface Pa of the reflecting mirror 240. More specifically, the display light from the laser display 210 travels forward along the vehicle front-rear direction and enters the reflecting mirror 240. Therefore, the reflecting surface 41 of the reflecting mirror 240 and the incident surface Pa that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). .

  On the other hand, since the display light from the laser display 210 is incident on the reflecting mirror 240 in the polarization direction PDa along the direction of azimuth angle 45 degrees, the polarization direction PDa is 45 with respect to the incident surface Pa. Is inclined.

  Thus, in the optical path OPa, the reflecting mirror 240 specularly reflects the display light incident from the laser display 210 toward the optical aperture 7 while enlarging the virtual image VIa. Due to the reflection, the azimuth angle indicating the polarization direction PDa is inverted to 135 degrees.

  Regarding the optical path OPb, the reflecting surface 41 faces each of the liquid crystal display 220 and the windshield 3 via the optical opening 7. In the optical path OPb, the display light from the liquid crystal display 220 enters the reflecting mirror 240 in the polarization direction PDb that is inclined with respect to the incident surface Pb of the reflecting mirror 240. More specifically, the display light from the liquid crystal display 220 travels along the vehicle front-rear direction to the front of the vehicle and is incident on the reflecting mirror 240. Therefore, the reflecting surface 41 of the reflecting mirror 240 and the incident surface Pb that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). .

  On the other hand, since the display light from the liquid crystal display 220 is incident on the reflecting mirror 240 in the polarization direction PDb along the direction of azimuth angle 45 degrees, the polarization direction PDb is 45 with respect to the incident surface Pb. Is inclined.

  In this way, in the optical path OPb, the reflecting mirror 240 specularly reflects the display light incident from the liquid crystal display 220 toward the optical opening 7 while enlarging the virtual image VIb. Due to the reflection, the azimuth angle indicating the polarization direction PDb is inverted to 135 degrees.

  As a result, the polarization direction PDa of the display light from the laser display 210 is a direction inclined with respect to the horizontal display direction immediately before the optical aperture 7 is incident on the dust cover 7a, and its azimuth angle is 135 degrees. Has become. Similarly, the polarization direction PDb of the display light from the liquid crystal display 220 is a direction inclined with respect to the horizontal display direction immediately before the optical opening 7 enters the dustproof cover 7a, and the azimuth angle is 135 degrees. Has become.

  That is, in the second embodiment, the polarization directions PDa and PDb of the respective display lights are aligned with each other immediately after the respective displays 210 and 220 are emitted and immediately before the optical apertures 7 are incident on the dustproof cover 7a. There is.

  According to the second embodiment described above, as the reflecting mirror in each of the optical paths OPa and OPb, only the common reflecting mirror 240 shared between the respective optical paths OPa and OPb corresponding to the respective display units 210 and 220 is provided. The polarization directions PDa and PDb of the respective display lights are aligned with each other immediately before entering the common reflecting mirror 240. By doing so, the polarization directions PDa and PDb of the respective display lights immediately before the light enters the optical aperture 7 without adding an element for converting the polarization directions PDa and PDb on the optical paths OPa and OPb, for example. Can be easily adjusted, and the display light on each of the optical paths OPa and OPb goes from the common reflecting mirror 240 to the windshield 3, so that the polarization direction PDa of each display light is reflected by the windshield 3. It is also possible to prevent the PDb from being displaced from each other.

(Third Embodiment)
As shown in FIGS. 11 and 12, the third embodiment of the present invention is a modification of the second embodiment. The third embodiment will be described focusing on the points different from the second embodiment.

  In the HUD device 300 of the third embodiment, as in the second embodiment, a total of two display devices, a laser display device 310 and a liquid crystal display device 320, and a common reflector 340 are provided as a plurality of display devices. There is. The arrangement of the respective display devices 310 and 320 is the same as that of the second embodiment, but the laser display device 310 is arranged such that the display light has a predetermined direction and is inclined with respect to the horizontal display direction. It emits light polarized in a different direction (specifically, a direction with an azimuth angle of 135 degrees).

  In the third embodiment, the phase difference plate 350 is provided between the laser display 310 and the reflecting mirror 340 on the optical path OPa. The retardation plate 350 is a ½ wavelength plate formed in a thin plate shape from, for example, sapphire glass or polycarbonate resin. When the display light from the laser display 310 passes through the phase difference plate 350, the phase difference plate 350 causes a phase difference with respect to the display light. As a result, the loss of the intensity of the display light is small, and the polarization direction PDa of the display light is rotated from the azimuth angle of 135 degrees before transmission to the azimuth angle of 45 degrees. That is, the polarization direction PDa of the display light on the optical path OPa has the same azimuth angle of 45 degrees as the optical path OPb when the light is incident on the reflecting mirror 340.

  Therefore, in the third embodiment, the polarization directions PDa and PDb of the respective display lights are different from each other immediately after the emission of the respective displays 310 and 320, but immediately before the optical aperture 7 is incident on the dustproof cover 7a. Aligned with each other.

  According to the third embodiment described above, the phase difference plate 350 arranged in the optical path OPa, which is a specific optical path, causes the polarization directions PDa and PDb of the respective display lights to match immediately before entering the optical aperture 7. First, the polarization direction PDa of the display light from the laser display 310 corresponding to the optical path OPa is rotated. This makes it possible to easily match the polarization directions PDa and PDb of the respective display lights immediately before entering the optical aperture 7. As a result, it is possible to prevent the relative balance of brightness between the display of the plurality of virtual images VIa and VIb from being impaired.

  Further, according to the third embodiment, the polarization directions PDa and PDb of the respective display lights are different from each other immediately after the display devices 310 and 320 are emitted. By doing so, the degree of freedom in arranging the respective display units 310, 320 is increased, so that the mountability of the HUD device 300 on the vehicle is improved and the polarization of each display light is reduced immediately before entering the optical opening 7. By making the directions PDa and PDb coincide with each other, it is possible to prevent the relative balance of brightness between the plurality of virtual images VIa and VIb from being impaired.

(Fourth Embodiment)
As shown in FIGS. 13 and 14, the fourth embodiment of the present invention is a modification of the second embodiment. The fourth embodiment will be described focusing on the points different from the second embodiment.

  In the HUD device 400 of the fourth embodiment, as in the second embodiment, a total of two display devices, a laser display device 410 and a liquid crystal display device 420, and a common reflecting mirror 440 are provided as a plurality of display devices. There is. The arrangement of the indicators 410 and 420 is the same as that of the second embodiment, but the laser indicator 410 emits the display light in a state in which the display light is polarized in the direction of the azimuth angle of 30 degrees as the predetermined direction. There is.

  In the fourth embodiment, a polarizing plate 452 is provided between the laser display 410 and the reflecting mirror 440 on the optical path OPa. The polarizing plate 452 is, for example, a thin plate-shaped polarizer mainly including a film obtained by adding iodine to polyvinyl alcohol, and has a transmission axis PTA and a light-shielding axis PSA that are substantially orthogonal to each other according to the orientation direction of iodine molecules. Have When light is transmitted through the polarizing plate 452, the light is converted into light having a polarization direction PDa in the direction along the transmission axis PTA. That is, the light component along the light blocking axis PSA is blocked by absorption. The transmission axis PTA of the polarizing plate 452 is in a direction that forms an acute angle with the azimuth angle immediately after the laser display 410 is emitted, and is aligned with the azimuth angle of the display light of the liquid crystal display 420 immediately after the laser display 410 is emitted. Set to the direction. That is, by setting the transmission axis PTA in the direction corresponding to the azimuth angle of 45 degrees, the polarization direction PDa of the display light is converted from the azimuth angle of 30 degrees before transmission to the azimuth angle of 45 degrees. That is, the polarization direction PDa of the display light on the optical path OPa has the same azimuth angle of 45 degrees as the optical path OPb when the light is incident on the reflecting mirror 440.

  Therefore, in the fourth embodiment, the polarization directions PDa and PDb of the respective display lights are different from each other immediately after the emission of the respective displays 410 and 420, but immediately before the incidence of the optical aperture 7 on the dustproof cover 7a. Aligned with each other.

  According to the fourth embodiment described above, the polarizing plate 452 arranged on the optical path OPa, which is a specific optical path, is arranged so that the polarization directions PDa and PDb of the respective display lights match immediately before entering the optical aperture 7. , The polarization direction PDa of the display light from the laser display 410 corresponding to the optical path OPa is changed. This makes it possible to easily match the polarization directions PDa and PDb of the respective display lights immediately before entering the optical aperture 7. As a result, it is possible to prevent the relative balance of brightness between the display of the plurality of virtual images VIa and VIb from being impaired.

(Fifth Embodiment)
As shown in FIGS. 15 and 16, the fifth embodiment of the present invention is a modification of the first embodiment. The fifth embodiment will be described focusing on the differences from the first embodiment.

  In the HUD device 500 according to the fifth embodiment, as in the first embodiment, a total of two indicators including a laser indicator 510 and a liquid crystal indicator 520 are provided as a plurality of indicators.

  The display screen 17 of the laser display 510 is oriented approximately above the vehicle in a posture in which the horizontal display direction is aligned with the lateral direction of the vehicle. The laser display 510 emits display light in a state in which it is polarized as a predetermined direction in a direction inclined with respect to the display horizontal direction (specifically, a direction with an azimuth angle of 135 degrees).

  On the other hand, the display screen 26 of the liquid crystal display 520 faces the front of the vehicle in a posture in which the horizontal display direction is along the left-right direction of the vehicle. The liquid crystal display 520 is a state in which the display light is polarized in a predetermined direction, that is, a direction inclined with respect to the horizontal display direction and different from the laser display 510 (specifically, a direction with an azimuth angle of 45 degrees). It is supposed to be emitted in.

  That is, immediately after the emission of each of the display devices 510 and 520, the polarization direction PDa of the display light from the laser display device 510 that forms the optical path OPa and the display light from the liquid crystal display device 520 that forms the optical path OPb. The polarization direction PDb is set to a direction in which the horizontal display direction is inverted with respect to the symmetry line.

  In the fifth embodiment, similarly to the first embodiment, the reflecting mirror 530 and the reflecting mirror 540 are arranged on the optical path OPa for the laser display 510. A reflecting mirror 540 is arranged on the optical path OPb for the liquid crystal display 520. That is, the reflecting mirror 540 is used between the optical paths OPa and OPb. However, the relationship between the reflecting mirrors 530 and 540 and the display light on the optical paths OPa and OPb is different from that in the first embodiment.

  Regarding the optical path OPa, the reflecting surface 31 of the reflecting mirror 530 faces each of the laser display 510 and the reflecting mirror 540. In the optical path OPa, the display light from the laser display 510 enters the reflecting mirror 530 in the polarization direction PDa inclined with respect to the incident surface Pa1 of the reflecting mirror 530. More specifically, the display light from the laser display device 510 travels upward along the vehicle in the vehicle up-down direction and enters the reflecting mirror 530. Therefore, the reflecting surface 31 of the reflecting mirror 530 and the incident surface Pa1 that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). .

  On the other hand, the display light from the laser display 510 is incident on the reflecting mirror 530 in the polarization direction PDa along the direction of the azimuth angle of 135 degrees, so that the polarization direction is 45 degrees with respect to the incident surface Pa1. It is inclined.

  Thus, in the optical path OPa, the reflecting mirror 530 specularly reflects the display light incident from the laser display device 510 toward the reflecting mirror 530. Due to the reflection, the azimuth angle indicating the polarization direction PDa is inverted to 45 degrees.

  Subsequently, the reflecting surface 41 faces each of the laser display 510 and the windshield 3 through the optical opening 7. The display light from the reflecting mirror 530 enters the reflecting mirror 540 in a polarization direction PDa inclined with respect to the incident surface Pa2 of the reflecting mirror 540. More specifically, the display light from the reflecting mirror 530 travels along the vehicle front-rear direction to the front of the vehicle and enters the reflecting mirror 540. Therefore, the reflecting surface 41 of the reflecting mirror 540 and the incident surface Pa2 that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). .

  On the other hand, since the display light from the reflecting mirror 530 is incident on the reflecting mirror 540 in the polarization direction PDa along the direction of azimuth angle 45 degrees, the polarization direction PDa is 45 degrees with respect to the incident surface Pa2. It is inclined.

  In this way, in the optical path OPa, the reflecting mirror 540 specularly reflects the display light incident from the reflecting mirror 530 toward the optical opening 7 while enlarging the virtual image VIa. Due to the reflection, the azimuth angle indicating the polarization direction PDa is inverted to 135 degrees.

  Regarding the optical path OPb, the reflecting surface 41 faces each of the liquid crystal display 520 and the windshield 3 via the optical opening 7. In the optical path OPb, the display light from the liquid crystal display 520 enters the reflecting mirror 540 in a polarization direction PDb that is inclined with respect to the incident surface Pa2 of the reflecting mirror 540. More specifically, the display light from the liquid crystal display 520 travels forward along the vehicle front-rear direction and enters the reflecting mirror 540. Therefore, the reflecting surface 41 of the reflecting mirror 540 and the incident surface Pb that can be defined by the incident direction of the display light are planes substantially perpendicular to the vehicle left-right direction (in other words, planes along the vehicle up-down direction and the vehicle front-rear direction). .

  On the other hand, the display light from the liquid crystal display 520 is incident on the reflecting mirror 540 in the polarization direction PDb along the direction of the azimuth angle of 45 degrees, so that the polarization direction PDb is 45 with respect to the incident surface Pb. Is inclined.

  Thus, in the optical path OPb, the reflecting mirror 540 specularly reflects the display light incident from the liquid crystal display device 520 toward the optical aperture 7 while causing the expansion effect of the virtual images VIa and VIb. Due to the reflection, the azimuth angle indicating the polarization direction PDb is inverted to 135 degrees.

  As a result, the polarization direction PDa of the display light from the laser display 510 is a direction inclined with respect to the horizontal display direction immediately before the optical aperture 7 enters the dustproof cover 7a, and its azimuth angle is 135 degrees. Has become. Similarly, the polarization direction PDb of the display light from the liquid crystal display 520 is a direction inclined with respect to the horizontal display direction immediately before the optical opening 7 is incident on the dust cover 7a, and the azimuth angle is 135 degrees. Has become.

  Therefore, in the fifth embodiment, the polarization directions PDa and PDb of the respective display lights are different from each other immediately after the emission of the respective displays 510 and 520, but immediately before the incidence of the optical opening 7 to the dustproof cover 7a. Aligned with each other.

  In order to add a detailed description of the changes in the polarization directions PDa and PDb, in the present embodiment, the display light of the corresponding optical paths OPa and OPb of the reflecting mirrors 530 and 540 is incident on the incident surfaces Pa1, Pa2, or Pb. On the other hand, a reflection mirror arranged so as to be incident in the polarization directions PDa and PDb inclined at a predetermined common angle is defined as a tilted polarization arrangement reflection mirror. In the fifth embodiment, the predetermined common angle is set to 45 degrees. For the optical path OPa, the reflecting mirrors 530 and 540 correspond to the inclined polarization arrangement reflecting mirrors, and for the optical path OPb, the reflecting mirror 540 corresponds to the inclined polarization arrangement reflecting mirrors. That is, in the present embodiment, all the reflection mirrors 530 and 540 correspond to the inclined polarization arrangement reflection mirrors.

  Further, of the optical paths OPa and OPb, an optical path in which the number of reflections by the inclined polarization arrangement reflecting mirror is even is defined as an even number of times of reflection optical path, and an optical path in which the number of reflections by the inclined polarization arrangement reflecting mirror is odd. Is defined as an odd-numbered reflection optical path. In the fifth embodiment, the optical path OPa corresponds to an even number of reflection optical paths because the number of reflections by the inclined polarization arrangement reflection mirror is two, that is, an even number, and the optical path OPb is reflected by the inclined polarization arrangement reflection mirror. Since the number of times is one, that is, an odd number, it corresponds to an odd number of times of the reflection optical path.

  In the optical paths OPa and OPb, the first tilted polarization arrangement reflecting mirror is the reflecting mirror 530 which is arranged closest to the laser display 510 side in the optical path OPa. In the optical path OPb, the first inclined polarization arrangement reflecting mirror is the reflecting mirror 540.

  Under these conditions, the polarization direction PDa of the display light immediately before entering the reflecting mirror 530, which is the first inclined polarization arrangement reflecting mirror in the optical path OPa that is the even-numbered reflecting light path, is the direction (azimuth angle 135 °) along the azimuth angle 135 degrees. It can be said that it is -45 degrees). On the other hand, in the optical path OPb that is the odd-numbered reflection optical path, the polarization direction PDb of the display light immediately before entering the first reflecting mirror 540 that is the inclined polarization arrangement reflecting mirror has an azimuth angle of 45 degrees (also referred to as an azimuth angle of -135 degrees). Along the direction.

  Here, the incident surface Pa1 of the reflecting mirror 530, which is the first tilted polarization arrangement reflecting mirror in the optical path OPa that is the even-numbered reflecting optical path, is extended in the direction along the azimuth angle of 90 degrees, so that the incident surface. The orthogonal axis OA orthogonal to Pa1 is along the direction of azimuth angle 0 degrees, that is, the display horizontal direction. Similarly, since the incident surface Pb of the reflecting mirror 530 which is the first inclined polarization arrangement reflecting mirror in the optical path OPb which is the odd-numbered reflection optical path is extended in the direction along the azimuth angle of 90 degrees, the incident surface concerned. The orthogonal axis OA orthogonal to Pb is along the direction of azimuth angle 0 degrees, that is, the horizontal display direction.

  Polarization direction PDa of display light immediately before incidence on the reflecting mirror 530, which is the first inclined polarization arrangement, in the optical path OPa that is the even-numbered reflection optical path, and first inclined polarization arrangement, in the optical path OPb that is the odd-numbered reflection optical path. The polarization direction PDb of the display light immediately before entering the reflecting mirror 540, which is a reflecting mirror, is line-symmetrical to each other with the orthogonal axis OA along the horizontal display direction as the object line. By satisfying such a condition, in the fifth embodiment, the polarization directions PDa and PDb of the respective display lights can be matched with each other just before the optical opening 7 enters the dustproof cover 7a. As a result, it is possible to prevent the relative balance of brightness between the display of the plurality of virtual images VIa and VIb from being impaired.

(Sixth Embodiment)
As shown in FIGS. 17 and 18, the sixth embodiment of the present invention is a modification of the fifth embodiment. The sixth embodiment will be described focusing on the points different from the fifth embodiment.

  In the HUD device 600 of the sixth embodiment, as in the fifth embodiment, as a plurality of indicators, a total of two indicators including a laser indicator 610 and a liquid crystal indicator 620, and reflecting mirrors 630 and 640 are provided. There is. The arrangement of the respective display devices 610 and 620 is the same as that of the fifth embodiment, but the laser display device 610 is a laser display device 610 in which the display light is a predetermined direction and is inclined with respect to the display horizontal direction. The light is emitted in a state in which the light is polarized in a direction (specifically, a direction with an azimuth angle of 45 degrees) combined with.

  In the sixth embodiment, a retardation plate 650 is provided between the laser display 610 and the reflecting mirror 630 on the optical path OPa. The basic structure of the retardation plate 650 is similar to that of the third embodiment. By the transmission of the phase difference plate 650, the polarization direction PDa of the display light changes from the azimuth angle of 45 degrees before transmission to the display horizontal direction with respect to the azimuth angle of the display light of the liquid crystal display 620 immediately after the liquid crystal display 620 exits. It is rotated to an azimuth angle of 135 degrees, which is the inverted direction with the direction as the symmetry line.

  The display light transmitted from the laser display 610 through the retardation plate 650 is incident on the reflecting mirror 630 in the polarization direction PDa along the direction of the azimuth angle of 135 degrees, as in the fifth embodiment. Is inclined by 45 degrees with respect to the incident surface.

  Thus, in the optical path OPa, the reflecting mirror 630 specularly reflects the display light incident from the laser display device 610 toward the reflecting mirror 640, similarly to the reflecting mirror 530 of the fifth embodiment. Due to the reflection, the azimuth angle indicating the polarization direction PDa is inverted to 45 degrees. That is, the polarization direction PDa of the display light on the optical path OPa has the same azimuth angle of 45 degrees as the optical path OPb when the light enters the reflecting mirror 640.

  Therefore, in the sixth embodiment, the polarization directions PDa and PDb of the respective display lights are aligned with each other immediately after the emission of the respective display devices 610 and 620, but immediately before the incidence of the optical opening 7 on the dustproof cover 7a. Are also aligned with each other.

  Then, similarly to the fifth embodiment, in the optical path OPa which is the even-numbered reflection optical path, the polarization direction PDa of the display light immediately before the incidence on the reflection mirror 530 which is the first inclined polarization arrangement reflection mirror and the odd-numbered reflection optical path. The polarization direction PDb of the display light immediately before entering the first reflection mirror 540 which is the inclined polarization arrangement reflection mirror in the optical path OPb is line-symmetric with respect to the orthogonal axis OA along the display horizontal direction as a target line. It has a relationship of.

  According to the sixth embodiment described above, the phase difference plate 650 disposed on either the even-numbered reflection optical path or the odd-numbered reflection optical path OPa determines the polarization direction PDa of the display light from the laser display 610. Rotate. Since such rotation is realized so as to establish the above-mentioned line-symmetrical relationship, it becomes possible to easily match the polarization directions PDa and PDb of the respective display lights immediately before entering the optical aperture 7. As a result, it is possible to prevent the relative balance of brightness between the display of the plurality of virtual images VIa and VIb from being impaired.

(Seventh embodiment)
As shown in FIGS. 19 and 20, the seventh embodiment of the present invention is a modification of the fifth embodiment. The seventh embodiment will be described focusing on the points different from the fifth embodiment.

  In the HUD device 700 of the seventh embodiment, as in the fifth embodiment, as a plurality of indicators, a total of two indicators including a laser indicator 710 and a liquid crystal indicator 720, and reflecting mirrors 730 and 740 are provided. There is. The arrangement of the respective display devices 710 and 720 is the same as that of the second embodiment, but the laser display device 710 emits the display light in a state in which the display light is polarized in the direction of the azimuth angle of 150 degrees as the predetermined direction. There is.

  In the seventh embodiment, a polarizing plate 752 is provided between the laser display 710 and the reflecting mirror 730 on the optical path OPa. The basic structure of the polarizing plate 752 is similar to that of the polarizing plate 452 of the fourth embodiment. However, the transmission axis PTA of the polarizing plate 752 of the seventh embodiment is in a direction that makes an acute angle with the azimuth angle immediately after the laser display 710 is emitted, and immediately after the liquid crystal display 720 is emitted in the display light of the liquid crystal display 720. With respect to the azimuth angle of, the orthogonal axis OA along the horizontal display direction is set as a symmetry line and inverted. That is, by setting the transmission axis PTA in the direction corresponding to the azimuth angle of 135 degrees, the polarization direction PDa of the display light is converted from the azimuth angle of 150 degrees before transmission to the azimuth angle of 135 degrees.

  The display light transmitted from the laser display 710 through the polarizing plate 752 is incident on the reflecting mirror 730 in the polarization direction PDa along the azimuth angle of 135 degrees, as in the fifth embodiment. , 45 ° with respect to the incident surface.

  Thus, in the optical path OPa, the reflecting mirror 730 specularly reflects the display light incident from the laser display 710 toward the reflecting mirror 740. Due to the reflection, the azimuth angle indicating the polarization direction PDa is inverted to 45 degrees. That is, the polarization direction PDa of the display light on the optical path OPa has the same azimuth angle of 45 degrees as that of the optical path OPb when entering the reflecting mirror 740.

  Therefore, in the seventh embodiment, the polarization directions PDa and PDb of the respective display lights are different from each other immediately after the emission of the respective displays 710 and 720, but immediately before the optical aperture 7 is incident on the dustproof cover 7a. Aligned with each other.

  Then, similarly to the fifth embodiment, in the optical path OPa which is the even-numbered reflection optical path, the polarization direction PDa of the display light immediately before entering the reflection mirror 730 which is the first tilted polarization arrangement reflection mirror, and the odd-numbered reflection optical path. The polarization direction PDb of the display light immediately before entering the first reflection mirror 740 which is the inclined polarization arrangement reflection mirror in the optical path OPb is line-symmetric with respect to the orthogonal axis OA along the display horizontal direction as the object line. It has a relationship of.

  According to the seventh embodiment described above, the polarizing plate 752 arranged on one of the even-numbered reflection optical path and the odd-numbered reflection optical path OPa changes the polarization direction PDa of the display light from the laser display 710. To do. Since such a change is realized so that the above-mentioned line-symmetrical relationship is established, it is possible to easily match the polarization directions PDa and PDb of the respective display lights immediately before entering the optical aperture 7. As a result, it is possible to prevent the relative balance of brightness between the display of the plurality of virtual images VIa and VIb from being impaired.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to those embodiments, and various embodiments and combinations are possible within the scope not departing from the gist of the present invention. Can be applied.

  Specifically, in the modified example 1, various configurations can be adopted as the plurality of display devices 10 and 20. For example, a configuration including two liquid crystal displays may be adopted. A configuration including two laser indicators may be adopted. Alternatively, a display using an OLED, for example, other than the liquid crystal display and the laser display may be adopted. More than two indicators may be employed.

  As a second modification, the display light in the polarized state emitted from the displays 10, 20 may be the display light in the state of being polarized into elliptically polarized light. In this case, the major axis direction of the elliptically polarized light is treated as the polarization directions PDa and PDb.

  As a third modification, the polarization directions PDa and PDb of the respective display lights may not be in the same direction but may be slightly deviated from each other as long as they are aligned with each other immediately before entering the optical aperture 7. Even if the polarization directions PDa and PDb of the respective display lights are deviated by about 5 to 10 degrees, a corresponding effect can be obtained.

  As a modified example 4, instead of the reflecting mirror 40 which is a common reflecting mirror, separate reflecting mirrors (concave mirrors) may be provided for the optical path OPa and the optical path OPb. Further, the reflecting mirror may not be provided in at least one of the optical paths OPa and OPb.

  As a fifth modified example, various configurations can be adopted for the optical opening 7. For example, the dustproof cover 7a may be a polarizing plate arranged with its transmission axes aligned with the polarization directions PDa and PDb of each display light immediately before entering the optical aperture. Even in this case, since the polarization directions PDa and PDb of the respective display lights are incident on the dustproof cover 7a, the loss of the respective display lights in the dustproof cover 7a can be suppressed, and a plurality of virtual images VIa and VIb can be displayed. , The effect of maintaining the relative balance of brightness is also obtained.

  As a sixth modification, a combiner provided as a projection member separately from the vehicle and installed inside the vehicle 1 may be used.

  As a modified example 7, a part of the optical paths OPa and OPb may be configured such that the display light travels in the left-right direction of the vehicle.

  As a modified example 8 of the first embodiment, the display light is incident on one of the reflecting mirrors 30 and 40 provided on the optical paths OPa and OPb in polarization directions PDa and PDb along a direction parallel to the incident surface. A reflector may be included.

  As a modified example 9 of the third, fourth, sixth and seventh embodiments, the phase difference plates 350 and 650 or the polarizing plates 452 and 752 may be arranged on the optical path OPb instead of the optical path OPa.

  As a modified example 10 of the fourth and seventh embodiments, a polarizing beam splitter may be used as the polarizer instead of the polarizing plates 452 and 752.

  As a modified example 11 of the sixth embodiment, the polarization directions PDa and PDb of the respective display lights may be different from each other immediately after the emission of the respective display devices 610.

  As a twelfth modified example, the present invention may be applied to various moving bodies (transportation devices) such as ships or airplanes other than the vehicle 1.

  1 vehicle (moving body), 3 windshield (projection member), 7 optical apertures, 10, 210, 310, 410, 510, 610, 710 laser indicator, 20, 220, 320, 420, 520, 620, 720 laser display, PDa, PDb polarization direction, OPa, OPb optical path, VIa, VIb virtual image

Claims (14)

A head-up display device mounted on a moving body (1), which displays a plurality of virtual images (VIa, VIb) visible to an occupant of the moving body by using reflection at a projection member (3),
A plurality of display devices (10, 20, 210, 220, 310) that emit the display light for displaying the virtual image in a state of being polarized in respective predetermined directions and configure the optical paths (OPa, OPb) by the display light. , 320, 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common for the plurality of display devices, is optically opened, and allows each of the display lights from each of the display devices to pass toward the projection member;
A reflecting mirror (30, 40, 240, 340, 440, 530, 540, 630, 640) arranged on at least one of the optical paths and reflecting the display light from the display corresponding to the optical path. , 730, 740),
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture,
As the reflecting mirror in each of the optical paths, only a common reflecting mirror shared between the optical paths corresponding to each of the display devices is provided,
The head-up display device in which the polarization directions of the respective display lights are aligned with each other immediately before entering the common reflecting mirror.   The head-up according to claim 1, wherein each of the display lights is incident on the reflecting mirror in the polarization direction along a direction parallel or perpendicular to an incident surface (Pa, Pa1, Pa2, Pb) of the reflecting mirror. Display device.   The head-up display device according to claim 1, wherein the polarization directions of the respective display lights are aligned with each other immediately after the respective display devices are emitted. A head-up display device mounted on a moving body (1), which displays a plurality of virtual images (VIa, VIb) visible to an occupant of the moving body by using reflection at a projection member (3),
A plurality of display devices (10, 20, 210, 220, 310) that emit the display light for displaying the virtual image in a state of being polarized in respective predetermined directions and configure the optical paths (OPa, OPb) by the display light. , 320, 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common for the plurality of display devices, is optically opened, and allows each of the display lights from each of the display devices to pass toward the projection member;
A reflecting mirror (30, 40, 240, 340, 440, 530, 540, 630, 640) arranged on at least one of the optical paths and reflecting the display light from the display corresponding to the optical path. , 730, 740),
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture,
A plurality of the reflecting mirrors are provided,
An inclined polarization arrangement in which each of the reflecting mirrors is arranged so that the display light of the corresponding optical path is incident on the reflecting mirror in a polarization direction inclined at a predetermined angle with respect to the incident surface of the reflecting mirror. Including one or more reflectors,
Each of the optical paths includes both an even-numbered reflection optical path in which the number of reflections by the inclined polarization arrangement reflecting mirror is an even number and an odd-numbered reflection optical path in which the number of reflections by the inclined polarization arrangement reflection mirror is an odd number. ,
The polarization direction of the display light immediately before entering the first oblique polarization arrangement reflecting mirror in the even-numbered reflection optical path, and the display light immediately before entering the first oblique polarization arrangement reflecting mirror in the odd-numbered reflection optical path. The polarization directions are head-up display devices that are in line symmetry with respect to the orthogonal axis (OA) orthogonal to the plane of incidence of the first inclined polarization arrangement reflecting mirror corresponding to each of the polarization directions.   The polarization direction of the display light from the display corresponding to the one optical path is rotated so as to be arranged in one of the even-numbered reflected optical path and the odd-numbered reflected optical path and to establish the line-symmetrical relationship. The head-up display device according to claim 4, further comprising a retardation plate (650) for controlling.   The polarization direction of the display light from the display corresponding to the one optical path is changed so that it is arranged in one of the even-numbered reflected optical path and the odd-numbered reflected optical path and the line-symmetrical relationship is established. The head-up display device according to claim 4, further comprising a polarizer (752) for controlling. A head-up display device mounted on a moving body (1), which displays a plurality of virtual images (VIa, VIb) visible to an occupant of the moving body by using reflection at a projection member (3),
A plurality of display devices (10, 20, 210, 220, 310) that emit the display light for displaying the virtual image in a state of being polarized in respective predetermined directions and configure the optical paths (OPa, OPb) by the display light. , 320, 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common to the plurality of display devices, optically opens, and allows each of the display lights from each of the display devices to pass toward the projection member,
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture,
Of the optical paths corresponding to the respective indicators, the optical path is arranged on at least one specific optical path, and the specific directions are adjusted so that the polarization directions of the respective display lights match immediately before entering the optical aperture. Head-up display device, further comprising a retardation plate (350) that rotates the polarization direction of the display light from the display corresponding to the optical path of. A head-up display device mounted on a moving body (1), which displays a plurality of virtual images (VIa, VIb) visible to an occupant of the moving body by using reflection at a projection member (3),
A plurality of display devices (10, 20, 210, 220, 310) that emit the display light for displaying the virtual image in a state of being polarized in respective predetermined directions and configure the optical paths (OPa, OPb) by the display light. , 320, 410, 420, 510, 520, 610, 620, 710, 720),
An optical opening (7) which is provided in common to the plurality of display devices, optically opens, and allows each of the display lights from each of the display devices to pass toward the projection member,
The polarization directions (PDa, PDb) of the respective display lights are aligned with each other immediately before entering the optical aperture,
It is arranged on at least one specific optical path of the respective optical paths corresponding to the respective display devices, and corresponds so that the polarization directions of the respective display lights match immediately before entering the optical aperture. The head-up display device further comprising a polarizer (452) that changes the polarization direction of the display light from the display.   A reflecting mirror (30, 40, 240, 340, 440, 530, 540, 630, 640) arranged on at least one of the optical paths and reflecting the display light from the display corresponding to the optical path. , 730, 740), the head-up display device according to claim 7 or 8.   The head-up according to claim 9, wherein each of the display lights is incident on the reflecting mirror in the polarization direction along a direction parallel or perpendicular to an incident surface (Pa, Pa1, Pa2, Pb) of the reflecting mirror. Display device.   The head-up display device according to claim 9 or 10, wherein a common reflecting mirror shared by the respective optical paths corresponding to the respective display devices is provided as the reflecting mirror. As the reflecting mirror in each of the optical paths, only a common reflecting mirror shared between the optical paths corresponding to each of the display devices is provided,
The head-up display device according to claim 9 or 10, wherein the polarization directions of the respective display lights are aligned with each other immediately before entering the common reflecting mirror.   The head-up display device according to claim 4, wherein the polarization directions of the respective display lights are different from each other immediately after the respective display devices are emitted. Said optical aperture, a head-up display device according to any one of claims 1 to 1 3 is closed by a transparent plate (7a) that transmits the said display light.

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