Head-up display device

Abstract

To provide a head-up display device with which it is possible to instantaneously switch between a real image and a virtual image for selective use by a simple device structure.SOLUTION: A head-up display device comprises: a display unit 12 including a liquid crystal display unit 124, a polarization switching element 125 capable of switching the polarization of emitted light between first polarized light and second polarized light before being output, and a beam splitter 126 that separates incident light into display light L1 constituting the first polarized light and display light L2 constituting the second polarized light before emission, the display unit 12 transmitting the light emitted by a light source 11 and displaying a display image; a reflection unit 13 for reflecting the display light L1 and L2 toward a windshield WS; and a control unit 15 for controlling the polarization switching element 125. The reflection unit 13 includes a first mirror 131 for reflecting the display light L1 and a second mirror 132 for reflecting the display light L2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a head-up display device that displays a desired image to a viewer by switching between a virtual image and a real image. [Background technology]

[0002] A head-up display device described in Patent Document 1 is known in the related art. In this head-up display device, in a configuration in which a display image displayed on a screen by light from a display is reflected onto a light-transmitting member, the front-to-rear positional relationship between the optical focus of an imaging optical system and the screen is changed to switch between a state in which a virtual image is visually recognized outside the light-transmitting member and a state in which a real image is visually recognized inside the light-transmitting member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-70074 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology described in Patent Document 1, when an observer switches between a virtual image and a real image, the relative positions of the object to be observed, the dihedral corner reflector array, and the reflecting member must be mechanically changed, which results in an increase in the size of the device, making it difficult to mount, and making it difficult to smoothly switch between the virtual image and the real image.

[0005] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a head-up display device that has a simple device configuration and can instantly switch between a real image and a virtual image for use. [Means for solving the problem]

[0006] The present invention relates to a head-up display device 1 having an outlet 17, and emitting display light L from the outlet 17 toward a light-transmitting member WS to allow a virtual image VI and a real image RI of a display image represented by the display light L to be visually recognized. The head-up display device 1 includes a display element 124, a switching output unit 125 that is provided on the outlet 17 side along an optical path from the display element 124 and is capable of switching the polarization of emitted light between a first polarized light and a second polarized light that are different from each other and outputting the switched light, and a switching output unit 125 that is provided on the outlet 17 side along the optical path from the switching output unit 125 and is capable of switching the polarization of incident light between a first polarized light L1 and a second polarized light L2. the first light ray L1 incident from the beam splitter 126 and reflecting the second light ray L2; a display unit 12 that transmits the light emitted by the light source 11 and displays the display image; a reflecting unit 13 that reflects the light representing the display image displayed on the display unit 12 toward the translucent member WS; and a control unit 15 that controls the switching output unit 125, wherein the reflecting unit 13 includes a first mirror 131 that reflects the first light ray L1 incident from the beam splitter 126, and a second mirror 132 that reflects the second light ray L2 incident from the beam splitter 126. Effect of the Invention

[0007] According to the present invention, it is possible to smoothly switch between virtual and real images and to visually recognize them without increasing the size of the device, using a simple configuration that only switches the light ray angle using a beam splitter depending on the polarization of the light. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing a configuration for generating a virtual image in a head-up display device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a configuration for generating a real image in a head-up display device according to an embodiment of the present invention. [Diagram 3] 5 is a schematic diagram showing the structures and optical paths of a light source and a display unit when a virtual image is displayed in the head-up display device according to the embodiment of the present invention. FIG. [Figure 4]5 is a schematic diagram showing the structures and optical paths of a light source and a display unit when a real image is displayed in the head-up display device according to the embodiment of the present invention. FIG. [Diagram 5] FIG. 1 is a diagram showing the structures of a Wollaston prism and a Rochon prism. [Figure 6] FIG. 2 is a functional block diagram showing the configuration of an image generating unit that controls the display content and the switching of polarization in the head-up display device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing a configuration in which a virtual image is generated in a head-up display device (hereinafter, referred to as a HUD device) according to this embodiment, and Fig. 2 is a diagram showing a configuration in which a real image is generated in the HUD device according to this embodiment.

[0010] 1 and 2, the HUD device 1 includes a light source 11 that is composed of, for example, a light emitting diode that emits light in the visible wavelength range mounted on a wiring board and emits white light, a display unit 12 that generates an image using light incident from the light source 11 and switches the polarization of the emitted light between first and second polarized light that are different from each other, a reflecting unit 13 that reflects display light L (display light L1 that represents a display image of a virtual image VI in the case of FIG. 1, and display light L2 that represents a display image of a real image RI in the case of FIG. 2) that represents a display image displayed on the display unit 12 toward a windshield WS (translucent member), and a control unit 15 that controls the display content on the display unit 12 and controls switching between the first and second polarized light, and these are housed in a housing 16. The housing 16 is provided with an opening 17 (exit) through which the display light L is emitted, and a cover glass 18 for protecting the inside is disposed in the opening 17. The windshield WS is an example of a light projecting member, and the opening 17 is an example of an exit.

[0011] The HUD device 1 is disposed below a windshield WS of a vehicle C (for example, inside an instrument panel), and emits display light L (L1, L2) and projects it onto the windshield WS. The display light L is generated by a light source 11 and a display unit 12 inside the HUD device 1. The display light L emitted from the display unit 12 travels along a reflecting unit 13 and is emitted through a cover glass 18 from an opening 17 of a housing 16. By viewing the display light L reflected by the windshield WS, an occupant DR of the vehicle C can view a virtual image VI on the far side of the windshield WS as shown in FIG. 1 and a real image RI on the near side as shown in FIG. 2.

[0012] In the virtual image VI shown in FIG. 1, information that is highly necessary to draw the attention of the occupant DR, such as vehicle information such as the speed and engine speed of the vehicle C, remaining energy, route guidance display such as turn-by-turn and maps, blind spot indicator, warning display such as speed limit exceeding warning, etc., is displayed on the other side of the windshield WS as seen from the occupant DR. In addition, in the real image RI shown in FIG. 2, for example, entertainment content, assistants and agents supporting the occupant DR, characters representing them, etc. are displayed in front of the windshield WS as seen from the occupant DR. These displays provide a driving environment in which the need for viewpoint movement and eye focal length adjustment is reduced. The virtual image VI and real image RI include characters and icons indicating these information as well as background parts, and in a planar view from the occupant DR, this is, for example, approximately rectangular.

[0013] Here, the configurations of the light source 11 and the display unit 12 shown in Fig. 1 and Fig. 2 will be described. Fig. 3 is a schematic diagram showing the structure and optical path of the light source 11 and the display unit 12 when a virtual image is displayed in the HUD device 1 according to this embodiment, and Fig. 4 is a schematic diagram showing the structure and optical path of the light source 11 and the display unit 12 when a real image is displayed in the HUD device 1 according to this embodiment. As shown in Figs. 3 and 4, the display unit 12 is provided on the emission port side along the optical path from the light source 11. The display unit 12 includes a condenser lens 121, a lenticular lens 122, a diffusion plate 123, a liquid crystal display unit 124 (display element), a polarization switching element 125 (switching output unit), and a beam splitter 126 in this order from the light source 11 side. The liquid crystal display unit 124 is an example of a display element, and the polarization switching element 125 is an example of a switching output unit. In FIGS. 3 and 4, light emitted from a light source 11 is condensed by a condenser lens 121, and then adjusted by a lenticular lens 122 and a diffusion plate 123 to have a uniform brightness.

[0014] The liquid crystal display unit 124 is, for example, a TFT (Thin Film Transistor) type display element, and displays a predetermined image using light emitted from the light source 11. The liquid crystal display unit 124 is connected to a display control unit 21, which will be described later in FIG. 6, and forms a predetermined image based on image data generated by drawing calculations in accordance with signals sent from the display control unit 21.

[0015] The polarization switching element 125 is provided at the rear stage of the liquid crystal display unit 124, and switches the polarization of the incident light to a first polarization or a second polarization that are different from each other. The polarization switching element 125 may switch the polarization by electrical processing, or a polarizing plate or a wavelength plate may be provided at the rear stage of the liquid crystal display unit 124 instead of the polarization switching element 125, and the polarization may be switched by physically rotating the optical axis direction at a predetermined angle with respect to the central axis. For example, the polarization switching may be performed such that a light beam having a specific polarization output from the liquid crystal display unit 124 is divided into a light beam having P polarization (an example of a first polarization) and a light beam having S polarization (an example of a second polarization) and then output toward the reflecting unit 13 described later. In addition, the polarization switching element 125 may be made of a polarizing plate, so that only a light beam having a specific polarization, such as S polarization or P polarization, is transmitted from among randomly polarized light beams.

[0016] The beam splitter 126 splits a light beam into multiple light beams with specific polarization. Examples include a Wollaston prism and a Rochon prism. A Wollaston prism can split a light beam with random polarization into two light beams with orthogonal polarizations. At this time, the two light beams are refracted at different exit angles and emitted. A Rochon prism, like a Wollaston prism, splits a light beam with random polarization into two light beams with orthogonal polarizations, while one of the polarized light beams is emitted from the prism without being refracted.

[0017] FIG. 5 is a diagram showing the structure of a Wollaston prism and a Rochon prism. FIG. 5(A) shows the structure of a Wollaston prism, and FIG. 5(B) shows the structure of a Rochon prism. Both of these prisms are made by cutting a material having birefringence (a property that shows a different refractive index depending on the polarization direction) such as calcite or quartz into a triangular prism shape and bonding two of them so that their optical axes are perpendicular to each other. In FIG. 5, the optical axis of the first prism 126a is set in the direction of P-polarized light toward the reflecting part 13, and the optical axis of the second prism 126b is set in the direction of S-polarized light toward the reflecting part 13. Note that the arrow A relating to the light ray in FIG. 5 represents the direction of polarization of the light ray, and the arrow B relating to the prism represents the optical axis of the prism. When a ray of light enters the boundary between first prism 126a and second prism 126b, the refractive index differs for each prism depending on the polarization direction, so even if first prism 126a and second prism 126b are made of the same material, light with different polarizations is bent at different refractive indices.

[0018] By using such a property, in the case of the Wollaston prism of Fig. 5(A), for example, a light ray having P-polarized light as the first polarization is refracted at the boundary surface and propagates toward the upper right direction of the paper, and a light ray having S-polarized light as the second polarization is refracted at the boundary surface and propagates toward the lower right direction of the paper. In the case of the Rochon prism of Fig. 5(B), for example, a light ray having P-polarized light as the first polarization is refracted at the boundary surface and propagates toward the lower right direction of the paper, and a light ray having S-polarized light as the second polarization is not refracted at the boundary surface and propagates in a straight line. In this way, by using the beam splitter 126, which is a crystal polarizer, the light ray can be easily split according to the polarization.

[0019] It should be noted that the P-polarized and S-polarized light shown in FIG. 5 is merely an example, and the P-polarized and S-polarized light may be reversed, and it is not limited to P-polarized and S-polarized light as long as the polarization angles are different; for example, it is desirable for the polarization angles to differ by at least 22.5 degrees.

[0020] 1 and 2 includes a first mirror 131, a second mirror 132, and a third mirror 133, each of which is flat or has a curved surface. Display light L emitted from the display unit 12 is reflected by the first mirror 131 and the third mirror 133, or by the second mirror 132 and the third mirror 133 and guided to the windshield WS, allowing the occupant DR to view a display image (a virtual image VI or a real image RI).

[0021] In reality, countless light rays are emitted from the display unit 12, but for simplicity's sake, in Figures 1 and 2, the light ray that is emitted from the center of the display unit 12 and passes through the center of the eye box of the occupant DR is referred to as display light L, the first light ray that is reflected by the first mirror 131 is referred to as display light L1, and the second light ray that is reflected by the second mirror 132 is referred to as display light L2.

[0022] The first mirror 131 and the second mirror 132 each have the property of reflecting or transmitting a light beam having a specific polarization, and here, for example, the first mirror 131 reflects a light beam having P polarization as the first polarization and transmits a light beam having S polarization as the second polarization. On the other hand, the second mirror 132 transmits a light beam having P polarization and reflects a light beam having S polarization. In the case of such a configuration, as shown in FIG. 1, when the display light L1 is switched to P polarization by the polarization switching element 125, the display light L1 which is P polarization is emitted by the beam splitter 126 in the direction of the first mirror 131, reflected by the first mirror 131, and guided to the third mirror 133. Also, as shown in FIG. 2, when the display light L2 is switched to S-polarized light by the polarization switching element 125, the S-polarized display light L2 is emitted by the beam splitter 126 in the direction of the second mirror 132, reflected by the second mirror 132, and guided to the third mirror 133.

[0023] In this way, the beam splitter 126 splits the display light L into display light L1 and display light L2 in response to the polarization switching control by the polarization switching element 125, and makes the emission angles of the display lights L1 and L2 different from each other, and leads the display lights L1 and L2 to the third mirror 133 via either the first mirror 131 or the second mirror 132 corresponding to each of them, thereby making it possible for the display lights L1 and L2 to generate different display images. In addition, by arranging the first mirror 131 and the second mirror 132 having such different characteristics, it is possible to prevent stray light of the display light L1 and the display light L2.

[0024] In addition, in FIG. 1, when the first mirror 131, the third mirror 133, and the windshield WS are regarded as one optical system, the first mirror 131 is disposed in a state (first state) in which the display unit 12 is located closer than the front focal point (focal point F1) of the optical system. In addition, in FIG. 2, when the second mirror 132, the third mirror 133, and the windshield WS are regarded as one optical system, the second mirror 132 is disposed in a state (second state) in which the display unit 12 is located farther than the front focal point (focal point F2) of the optical system. By disposing the first mirror 131 and the second mirror 132 in such a state, the display image displayed by the display light L1 is displayed as a virtual image VI that is far from the occupant DR, and the display image displayed by the display light L2 is displayed as a real image RI that is close to the occupant DR. That is, an optical system capable of displaying a virtual image VI and a real image RI can be constructed.

[0025] The control unit 15 shown in Fig. 1 and Fig. 2 controls the display content on the display unit 12 and controls switching between the first polarized light and the second polarized light. Fig. 6 is a functional block diagram showing the configuration of an image generating unit that controls the display content and the switching between the polarized light in the HUD device 1 according to this embodiment. Note that Fig. 6 shows only the minimum necessary configuration directly related to the above processing, and other known configurations are omitted. In Fig. 6, the image generating unit 10 includes a control unit 15, a light source 11, and a display unit 12. The control unit 15 includes a display control unit 21 that issues a command to the display unit 12 to generate light that displays an arbitrary image based on information sent from various devices 30, such as devices that acquire information, such as a vehicle speed sensor, an IMU (Inertial Measurement Unit) sensor, a fuel sender, devices that process the acquired information, a navigation device, a RADAR (Radio Detecting and Ranging), a LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), and a display unit drive unit 22 that controls the switching of the polarization direction based on a signal sent from a switch 20 in response to, for example, a switch in driving mode (manual driving, automatic driving) or a switch in driving location.

[0026] As described above, the display unit 12 also includes a TFT-type liquid crystal display unit 124 that forms light representing an arbitrary image in accordance with a signal sent from the display control unit 21, and a polarization switching element 125 that switches the emitted display light L to either the first polarized display light L1 or the second polarized display light L2 in accordance with a signal sent from the display unit drive unit 22.

[0027] In the configuration of FIG. 6, for example, during manual driving, the display unit drive unit 22 controls the polarization switching element 125 to emit display light L1, which is the first polarization, based on a signal transmitted from the switch 20. At this time, the display control unit 21 controls the liquid crystal display unit 124 to generate display light L1 representing vehicle information, route guidance information, warning display, and the like as described above. Also, for example, during automatic driving, the display unit drive unit 22 controls the polarization switching element 125 to emit display light L2, which is the second polarization, based on a signal transmitted from the switch 20. At this time, the display control unit 21 controls the liquid crystal display unit 124 to generate display light L2 representing an assistant or agent supporting the occupant DR as described above, or a character representing them. Then, the light beam emitted from the light source 11 passes through the display unit 12 controlled as described above to generate display light L, which is then emitted to the reflector 13.

[0028] 1 and 2, in order to generate a virtual image VI represented by the display light L1, the light beam emitted from the light source 11 needs to be emitted as the display light L1 from the display unit 12 in an oblique direction as shown in Fig. 1. On the other hand, in order to generate a real image RI represented by the display light L2, the light beam emitted from the light source 11 needs to be emitted as the display light L2 from the display unit 12 in an approximately vertical direction as shown in Fig. 2.

[0029] As shown in FIG. 3, the light beam emitted from the liquid crystal display unit 124 is set by the polarization switching element 125 so that only light beams having P-polarized light as the first polarization are emitted. For example, when a Rochon prism is used for the beam splitter 126, the light beam incident on the Rochon prism is refracted and travels toward the first mirror 131 as shown in FIG. 1. That is, the display light L1 emitted to the liquid crystal display unit 124 is angled from the vertical state according to the refractive index. When the display light L1 forms a display image, as shown in FIG. 1, the occupant DR can see the virtual image VI, which is the display image of the display light L1, as if it were inclined with respect to the road surface. Note that the inclination angle of the virtual image VI at this time is preferably less than 45 degrees (first angle) with respect to the road surface.

[0030] Also, as shown in FIG. 4, the light beam emitted from the liquid crystal display unit 124 is set by the polarization switching element 125 so that only the light beam having S-polarized light as the second polarization is emitted. For example, when a Rochon prism is used for the beam splitter 126, the light beam incident on the Rochon prism is not refracted and goes to the second mirror 132 as shown in FIG. 2. That is, the display light L2 emitted is in a state of traveling vertically straight to the liquid crystal display unit 124. When the display light L2 forms a display image, as shown in FIG. 2, the occupant DR can see the real image RI, which is the display image of the display light L2, as if it is standing vertically to the road surface. Note that the inclination angle of the real image RI at this time is desirably 45 degrees or more (second angle) with respect to the road surface.

[0031] Furthermore, since the liquid crystal display unit 124 generally has directivity, if the beam splitter 126 is not used, for example, when the direction of the light source 11 is adjusted to brighten the display of the virtual image VI, the display of the real image RI becomes dark, and conversely, when the direction of the light source 11 is adjusted to brighten the real image RI, the virtual image VI becomes dark. Also, if the light source 11 is disposed at an intermediate position, unevenness in luminance occurs between the virtual image VI and the real image RI, making it difficult to maintain the uniformity of luminance. However, as in the HUD device 1 according to this embodiment, it is possible to maintain the uniformity of luminance by using the beam splitter 126. That is, if the polarization of the light beam emitted from the light source 11 is random, the amount of light of the display light L finally transmitted through the beam splitter 126 and emitted is almost equal regardless of whether the polarization switching element 125 is set to the state shown in FIG. 3 or FIG. 4. In other words, if the virtual image VI and real image RI can be generated with the same brightness, and the brightness is uniform for the light rays passing through the display unit 12, the brightness distribution of the virtual image VI and real image RI will be uniform, making it possible to maintain uniformity.

[0032] In this case, if the light beam emitted from the light source 11 or the display unit 12 has a large amount of a specific polarization, for example, if only P-polarized light is emitted, an appropriate wave plate may be inserted after the display unit 12 to change the direction of polarization in order to emit light beams with S-polarized light. The direction of polarization may be controlled by controlling the insertion / removal of such a wave plate. In other words, even if the polarization of the light beam emitted from the light source 11 is random or if a large amount of light beams with a specific polarization are emitted, it is possible to emit a desired polarized light beam by controlling the polarization switching element 125 or the insertion / removal of the wave plate as described above.

[0033] 1 and 2, a virtual image VI standing perpendicular to the road surface and a real image RI tilted with respect to the road surface can be generated. Specifically, when the first mirror 131, the third mirror 133, and the window shield WS are regarded as one optical system, the first mirror 131 is positioned so that the display unit 12 is farther away than the focal length (focus F1) of the optical system, and when the second mirror 132, the third mirror 133, and the window shield WS are regarded as one optical system, the display unit 12 is positioned so that the display unit 12 is closer than the focal length (focus F2) of the optical system.

[0034] Furthermore, in the above, a case has been described in which, for example, a Rochon prism is used as the beam splitter 126, but a Wollaston prism or other beam splitters 126 can also be used, and the positions and angles of the first mirror 131 and the second mirror 132 can be adjusted taking into consideration the respective directions (angles) in which the display light L1, which is the first polarized light, and the display light L2, which is the second polarized light, are emitted based on the characteristics of each beam splitter 126.

[0035] Furthermore, as shown in Figures 1 and 2, it is desirable to arrange the first mirror 131 and the second mirror 132 so that the incident optical path of the display light L1 from the beam splitter 126 to the first mirror 131 does not overlap with the incident optical path of the display light L2 from the beam splitter 126 to the second mirror 132, and so that the exit optical path of the display light L1 after reflection by the first mirror 131 does not overlap with the exit optical path of the display light L2 after reflection by the second mirror 132.

[0036] In this manner, the HUD device 1 according to this embodiment includes a liquid crystal display unit 124, a polarization switching element 125 that is provided closer to the exit along the optical path than the liquid crystal display unit 124 and that is capable of switching the polarization of emitted light into first polarization and second polarization that are different from each other and outputting the switched polarization, and a beam splitter 126 that is provided closer to the exit along the optical path than the polarization switching element 125 and that separates the incident light into display light L1 having the first polarization and display light L2 having the second polarization and outputs the separated light. The display unit 12 transmits the light emitted by the light source 11 and displays a display image. The optical system has a reflecting unit 13 that reflects light representing the display image displayed on the window 122 toward the window shield WS, and a control unit 15 that controls the polarization switching element 125. The reflecting unit 13 includes a first mirror 131 that receives display light L1 from the beam splitter 126 and reflects it, and a second mirror 132 that receives display light L2 from the beam splitter 126 and reflects it. This makes it possible to smoothly switch between a virtual image VI and a real image RI and to visually recognize them, with a simple configuration that simply switches the light ray angle using the beam splitter 126 according to the polarization of the light, without increasing the size of the device.

[0037] Furthermore, by using the beam splitter 126 as described above, if the polarization of the light rays emitted from the light source 11 is random, the amount of light of the display light L that ultimately passes through the beam splitter 126 and is emitted will be almost equal, and the virtual image VI and real image RI can be generated with the same brightness.If the brightness of the light rays in the range passing through the display unit 12 is uniform, the brightness distribution of the virtual image VI and real image RI will be uniform, making it possible to maintain uniformity.

[0038] Furthermore, the first mirror 131 and the second mirror 132 are arranged such that, when the beam splitter 126 emits display light L1, the positional relationship between the optical focus of the imaging optical system including the first mirror 131, the third mirror 133, and the window shield WS and the display unit 12 is in a first state (state in Figure 1) in which the display unit 12 is closer to the exit than the focus F1, and when the beam splitter 126 emits display light L2, the positional relationship is in a second state (state in Figure 2) in which the display unit 12 is closer to the light source 11 than the focus F2. This allows the occupant DR to view a virtual image VI that is inclined with respect to the road surface and a real image RI that is perpendicular to the road surface, and the desired information can be displayed in an appropriate manner depending on the driving environment.

[0039] Furthermore, the control unit 15 controls the polarization switching element 125 so that the virtual image VI to be viewed in the first state (state of Figure 1) is viewed at a first angle of less than 45 degrees with respect to the road surface, and the real image RI to be viewed in the second state (state of Figure 2) is viewed at a second angle of 45 degrees or more with respect to the road surface, thereby allowing the occupant DR to view the virtual image VI which is inclined with respect to the road surface, and also to view the real image RI which stands perpendicular to the road surface, thereby further improving visibility.

[0040] Furthermore, the polarization switching element 125 is controlled so that when the vehicle C is in manual driving mode, the first polarization is output so that a virtual image VI is viewed in the first state (state of Figure 1), and when the vehicle C is in automatic driving mode, the second polarization is output so that a real image RI is viewed in the second state (state of Figure 2), so that desired information can be displayed in an appropriate manner depending on the driving environment.

[0041] Furthermore, the first mirror 131 and the second mirror 132 are positioned so that the incident optical path from the beam splitter 126 to the first mirror 131 does not overlap with the incident optical path from the beam splitter 126 to the second mirror 132, and so that the exiting optical path after reflection from the first mirror 131 does not overlap with the exiting optical path after reflection from the second mirror 132. This reliably prevents interference between the virtual image VI and the real image RI, and maintains the brightness and uniformity of the virtual image VI and the real image RI. [Explanation of symbols]

[0042] C Vehicle DR Crew Member F(F1,F2) Focus L(L1,L2) Display light VI Virtual Image RI real image WS Window Shield 1 HUD device 10 Image Generation Unit 11 Light source 12 Display section 13 Reflector 15 Control section 16 Case 17 Opening 18 Coverslip 20 Switch 21 Display control unit 22 Display drive unit 30 Various Devices 121 Condenser Lens 122 Lenticular Lens 123 Diffuser 124 LCD display section 125 Polarization switching element 126 Beam Splitter 126a First Prism 126b Second Prism 131 Mirror No. 1 132 2nd Mirror 133 3rd Mirror

Claims

1. A head-up display device having an emission port, and emitting display light from the emission port toward a light-transmitting member to allow a virtual image and a real image of a display image represented by the display light to be visually recognized, a display element; a switching output section that is provided along the optical path closer to the exit than the display element and that is capable of switching the polarization of emitted light between a first polarized light and a second polarized light that are different from each other and outputting the light; and a beam splitter that is provided along the optical path closer to the exit than the switching output section and that separates incident light into a first light ray having the first polarized light and a second light ray having the second polarized light and outputs the separated light, the display section transmitting light emitted by a light source and displaying the display image; a reflecting section that reflects light representing the display image displayed on the display section toward the light-transmitting member; A control unit that controls the switching output unit; having The reflecting portion is a first mirror that reflects the first light beam incident from the beam splitter; a second mirror that reflects the second light beam incident from the beam splitter; Includes A head-up display device.

2. The first mirror and the second mirror are When the beam splitter emits the first light beam, a positional relationship between an optical focal point of an imaging optical system including the light-transmitting member and the reflecting portion and the display portion is in a first state in which the display portion is closer to the exit port than the optical focal point, When the beam splitter emits the second light beam, the display unit is in a second state in which the display unit is closer to the light source than the optical focus.

2. The head-up display device according to claim 1, wherein the head-up display device is arranged as follows.

3. The control unit is The switching output unit is controlled so that the virtual image to be viewed in the first state is viewed at a first angle of less than 45 degrees with respect to a road surface, and the real image to be viewed in the second state is viewed at a second angle of 45 degrees or more with respect to the road surface.

3. The head-up display device according to claim 2.

4. The control unit is The switching output unit is controlled so that the first polarized light is output when the vehicle is in a manual driving mode, and the virtual image is viewed in the first state, and the second polarized light is output when the vehicle is in an automatic driving mode, and the real image is viewed in the second state.

4. The head-up display device according to claim 3.

5. The first mirror and the second mirror are An incident optical path from the beam splitter to the first mirror does not overlap with an incident optical path from the beam splitter to the second mirror; and The first mirror is disposed so that the exiting optical path after reflection from the first mirror does not overlap with the exiting optical path after reflection from the second mirror.

5. The head-up display device according to claim 1,

6. The beam splitter comprises a crystal polarizer.

5. The head-up display device according to claim 1,

Images