JP2014191321A - Head-up display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head-up display (HUD) device having good visibility of a virtual image.SOLUTION: A head-up display device 1 is installed in a vehicle 2 and includes an illumination optical system 10 for projecting an image using linearly polarized light from a light source, and an imaging optical system 20 for projecting the light source light projected by the illumination optical system 10 onto a projection plane 5 of the vehicle 2 to form the image as a virtual image 7; and the head-up display device 1 displays the virtual image 7 to be visible from the indoor space the vehicle 2. The imaging optical system 20 includes a polarizer 22 which is disposed with the axial direction thereof aligned to the light source light so as to guide the light source light toward the projection plane 5.

Description

  The present invention relates to a head-up display device that is installed on a moving body and displays a virtual image so as to be visible from the room of the moving body.

  Conventionally, illumination optical systems applicable to head-up display devices (hereinafter referred to as HUD devices) are known. For example, an illumination optical system applicable to the HUD device disclosed in Patent Document 1 can project an image formed by a plurality of liquid crystal pixels, and includes a light source and a polarizer as a polarization beam splitter. The polarizer transmits light from the light source (hereinafter referred to as light source light) in the on-state pixels of the liquid crystal pixels. Further, the polarizer reflects the light source light in the off-state pixel of the liquid crystal pixels.

Special table 2009-521721 gazette

  By the way, in the HUD device installed in the moving body, there is a problem that disturbance light such as sunlight enters the HUD device directly from outside the moving body or through the windshield of the moving body. When disturbing light enters the HUD device, disturbing light scattered in an unintended direction within the device overlaps with the light source light, which may cause ghosts and flares that should not be displayed in the virtual image or the back of the virtual image. A decrease in contrast occurs as the ground luminance increases.

  Therefore, the present inventor has to block a part of the disturbance light incident on the HUD device including the imaging optical system that projects the light source light projected by the illumination optical system on the projection surface of the moving body by the polarizer. Inspired. And in the HUD apparatus to which the illumination optical system disclosed by patent document 1 was applied, the grade of the effect of the said idea structure was examined. However, in this case, the polarizer is provided in the illumination optical system against disturbance light that reaches the imaging optical system earlier than the illumination optical system. Therefore, most of the disturbance light is scattered in an unintended direction by the imaging optical system before reaching the polarizer, and it has been understood that the disturbance light blocking effect by the polarizer is hardly obtained.

  This invention is made | formed in view of the subject demonstrated above, Comprising: The objective is to provide the HUD apparatus with favorable visibility of a virtual image.

  The present invention is an illumination optical system that is installed on a moving body and projects an image as linearly polarized light source light, and the light source light projected by the illumination optical system is projected onto a projection surface of the moving body, whereby the image is converted into a virtual image. An image forming optical system for forming an image, and a head-up display device that displays a virtual image so as to be visible from the inside of a moving body, wherein the image forming optical system guides light source light to a projection surface It has the polarizer arrange | positioned by aligning an axial direction with respect to light source light, It is characterized by the above-mentioned.

  According to the present invention, since the polarizer is provided in the imaging optical system that the disturbance light reaches before the illumination optical system, most of the disturbance light incident on the HUD device reaches the polarizer, The polarizer blocks a part of the reaching ambient light. Then, disturbance light that is unintentionally scattered in the HUD device is reduced. According to this, it is possible to suppress the occurrence of ghosts and flares in the virtual image and the occurrence of a decrease in contrast due to an increase in the background luminance of the virtual image. In addition, since the polarizers are arranged with their axial directions aligned so as to guide the light source light to the projection surface, it is possible to suppress a decrease in luminance of the light source light due to the polarizer. From the above, it is possible to provide a HUD device with good virtual image visibility.

  In a further feature of the present invention, the polarizer is of a reflective type, and the reflection axis of the polarizer is set in the same direction as the polarization axis of the light source light.

  According to such a feature, the light source light is reflected with high reflectance by the reflective polarizer whose reflection axis is set in the same direction as the polarization axis of the light source light. Therefore, it is possible to enhance the effect of suppressing the luminance reduction of the light source light by the polarizer.

  Further, according to a further feature of the present invention, disturbance light reaching from the outside of the moving body is divided into transmitted light and reflected light.

  According to such a feature, disturbance light that reaches the polarizer from the outside of the moving body is divided into transmitted light that is transmitted without being absorbed by the polarizer and reflected light that is reflected by the polarizer. Therefore, since heat generation of the polarizer body due to absorption of disturbance light is suppressed, it is possible to suppress a decrease in product life of the HUD device.

It is a schematic diagram which shows the installation state to the vehicle of the HUD apparatus in 1st Embodiment. It is a disassembled perspective view which shows the structure of the illumination optical system in 1st Embodiment. It is a schematic diagram which shows the structure of the HUD apparatus in 1st Embodiment. It is a perspective view which shows partially the polarizer in 1st Embodiment. It is a schematic diagram which shows the example of control of the disturbance light which injects into the HUD apparatus in 1st Embodiment. It is a schematic diagram which shows the structure of the HUD apparatus in 2nd Embodiment.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description may be abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other part of the configuration. In addition, not only combinations of configurations explicitly described in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if they are not explicitly specified unless there is a problem with the combination. .

(First embodiment)
As shown in FIG. 1, the HUD device 1 according to the first embodiment of the present invention is installed in a vehicle 2 as a moving body and is accommodated in an instrument panel 3. The HUD device 1 displays the virtual image 7 through the windshield 4 of the vehicle 2 so as to be visible from inside the vehicle 2. Specifically, the light source light emitted from the HUD device 1 and reflected by the windshield 4 reaches the eye point 6 of the vehicle occupant (hereinafter, vehicle occupant). The vehicle occupant can visually recognize the virtual image formed in front of the windshield 4 by perceiving the light source light reaching the eye point 6.

  The windshield 4 of the vehicle 2 is formed in a plate shape made of a translucent glass substrate or the like, and is held integrally with the vehicle 2. The room-side surface of the windshield 4 forms a projection surface 5 on which light source light is projected in a curved concave shape or a flat planar shape. Further, instead of the windshield 4, a combiner separate from the vehicle 2 may be installed in the vehicle 2 and the light source light may be projected onto the combiner.

  The HUD device 1 includes an illumination optical system 10, an imaging optical system 20, and a package 40. The illumination optical system 10 is an optical system that projects an image toward the imaging optical system 20 as linearly polarized light source light. As shown in FIG. 2, the illumination optical system 10 includes a backlight 12, a projection lens 14, and a liquid crystal panel 16. Have. The backlight 12 includes a light source 120, a condenser lens 122, a diffusion plate 124, and the like, and is accommodated in the support member 18.

  The light source 120 is a light emitting element made of a light emitting diode, for example, and is disposed on the light source circuit board 126. The light source 120 is electrically connected to a power source (not shown) through a wiring pattern (not shown) on the light source circuit board 126. The light source 120 emits light when energized, thereby projecting light beam-shaped light source light toward the condenser lens 122.

  The condenser lens 122 is a translucent convex lens made of synthetic resin or glass, and is disposed between the light source 120 and the diffusion plate 124. For example, the condensing lens 122 is formed such that the surface on the light source 120 side is a flat surface and the surface on the diffusion plate 124 side is a convex surface, thereby condensing the light source light from the light source 120 toward the diffusion plate 124. Project.

  The diffusing plate 124 is a translucent or milky white plate formed of a synthetic resin such as polycarbonate in which a light diffusing material is kneaded, and is disposed between the condenser lens 122 and the projection lens 14. The diffusion plate 124 emits the light source light adjusted in luminance uniformity toward the projection lens 14 by diffusing the light source light from the condenser lens 122.

  The projection lens 14 is a translucent convex lens made of synthetic resin or glass, and is disposed between the backlight 12 and the liquid crystal panel 16. For example, the projection lens 14 is formed with a surface on the backlight 12 side as a flat surface and a surface on the liquid crystal panel 16 side as a convex surface, thereby condensing the light source light diffused by the diffusion plate 124. Project toward 16.

  The liquid crystal panel 16 is formed by laminating functional layers such as a liquid crystal layer in the projection direction of the light source light, and is disposed between the projection lens 14 and the imaging optical system 20. The liquid crystal panel 16 is, for example, a dot matrix TFT liquid crystal panel, and can project an image formed by a plurality of liquid crystal pixels arranged in a two-dimensional direction. Although not shown, in the liquid crystal panel, a polarizing plate is disposed across all the liquid crystal pixels. The light source light from the projection lens 14 is converted into linearly polarized light by passing through the polarizing plate in the liquid crystal panel 16 in the on-state pixels of the liquid crystal pixels, and is directed from the liquid crystal panel 16 to the imaging optical system 20. Projected. On the other hand, the light source light from the projection lens 14 is absorbed by the polarizing plate in the liquid crystal panel 16 and hardly passes through the liquid crystal panel 16 in the off-state pixels of the liquid crystal pixels.

  Thus, the light source light transmitted through the liquid crystal panel 16 becomes linearly polarized light having a polarization axis in the coaxial direction in all the liquid crystal pixels by the polarizing plate straddling all the liquid crystal pixels. Here, the polarization axis in the present embodiment is an axis indicating the vibration direction of the electric field in linearly polarized light, and is generally called a polarization direction. The polarization axis of the light source light is projected toward the imaging optical system 20 in a direction that forms an angle of 45 degrees with respect to the horizontal direction of the image in the present embodiment, but may be in another direction.

  The illumination optical system 10 only needs to project an image toward the imaging optical system 20 as linearly polarized light source light. For example, a mercury lamp or the like may be used for the backlight 12 instead of using a light emitting diode. Further, the illumination optical system 10 does not have to project the non-polarized light source light as linearly polarized light by the liquid crystal panel 16 or the like, and obtains linearly polarized light by using a laser oscillator or the like for the light source 120, for example. Also good.

  As shown in FIG. 3, the imaging optical system 20 is an optical system that forms an image as a virtual image 7 by projecting light source light projected by the illumination optical system 10 onto the projection surface 5. The imaging optical system 20 has a polarizer 22.

  As shown in FIG. 4, the polarizer 22 in the present embodiment is formed by attaching a polarizing film 26 to one surface of a translucent plate-like substrate 24 made of synthetic resin or glass. And the polarizer 22 forms the entrance plane 28 exposed to the polarizing film 26 side. The polarizing film 26 is formed into a film shape with a translucent synthetic resin, and metal wires 30 such as aluminum are arranged in parallel at a predetermined pitch PT in a direction along the film surface. Here, the predetermined pitch PT is set to be smaller than the wavelength of the light source light that is incident light, and is set to about 100 μm to 200 μm, for example.

  The characteristics of the polarizing film 26 will be described in detail. When incident light having an electric field oscillation direction parallel to the metal wire 30 is incident on the incident surface 28, the free electrons in the metal wire 30 vibrate along the metal wire 30, thereby canceling the electric field of the incident light. Thus, most of the incident light is reflected without being transmitted. In other words, when the polarization axis of incident light is parallel to the metal wire 30, most of the incident light is reflected. In the present embodiment, a direction parallel to the metal wire 30 is referred to as a reflection axis as a direction in which the reflectance is maximum. On the other hand, when incident light having an electric field vibration direction perpendicular to the metal wire 30 is incident on the incident surface 28, the free electrons in the metal wire 30 cannot respond to the electric field vibration direction. Most of the light is transmitted without being influenced by the metal wire 30. In other words, when the polarization axis of the incident light is perpendicular to the metal wire 30, most of the incident light is transmitted. In the present embodiment, the direction perpendicular to the metal wire 30 is referred to as a transmission axis as the direction in which the transmittance is maximum. When the polarization axis of the incident light is oblique with respect to the reflection axis and the transmission axis of the polarizing film 26, free electrons in the metal wire 30 are in the direction parallel to the metal wire 30 in the electric field of the incident light. Offset only the components. Therefore, the amplitude reflectance of incident light changes according to the cosine function with respect to the angle formed by the reflection axis and the polarization axis, and the amplitude transmittance of incident light varies with the cosine function with respect to the angle formed by the transmission axis and the polarization axis. Can be thought of as changing. More precisely, when the incident light is not perpendicular to the incident surface 28, the angle formed between the direction of the reflection axis or the transmission axis and the direction in which the polarization axis is orthogonally projected on the incident surface is defined as the reflection axis or the transmission axis. It can be considered as an angle formed with the polarization axis.

  As shown in FIG. 3, the polarizer 22 having the polarizing film 26 having such characteristics is disposed, for example, with the incident surface 28 on the polarizing film 26 side facing the liquid crystal panel 16 of the illumination optical system 10. Further, the polarizer 22 is arranged so that the reflection axis formed by the polarizing film 26 matches the polarization axis of the light source light projected as linearly polarized light from the illumination optical system 10. More preferably, the reflection axis of the polarizer 22 is set in a direction coaxial with the polarization axis of the light source light, and in particular, in this embodiment, is set to form an angle of 45 degrees with respect to the horizontal direction of the image. And the polarizer 22 reflects the light source light which injects into the entrance plane 28 with a high reflectance by the setting of a reflection axis. For example, the polarizer 22 can reflect the light source light with an energy reflectivity of 90% or more, which is equivalent to that of a reflector with a general aluminum mirror coating.

  As shown in FIG. 4, the polarizer 22 has a curved incident surface 28. Specifically, the incident surface 28 is formed as a smooth curved surface as a concave surface in which the central portion of the polarizer 22 is recessed. The polarizer 22 having such a shape reflects the light source light from the illumination optical system 10 toward the projection surface 5 of the vehicle 2 while adjusting the reflection direction in accordance with the incident position on the incident surface 28, thereby forming the virtual image 7. Adjust the imaging state. Examples of adjustment of the imaging state of the virtual image 7 include enlarging the virtual image 7 and correcting distortion of the virtual image 7.

  Further, as shown in FIG. 3, the polarizer 22 can be driven to swing on a first swing shaft 32 perpendicular to the incident surface 28, for example. Specifically, although not shown, the first rocking shaft 32 has a first rocking portion that can be rocked and driven. The first oscillating unit oscillates and drives the polarizer 22 in accordance with a drive signal from an electrically connected controller. Further, the first oscillating portion may be one that oscillates the polarizer 22 by manually operating a mechanically connected cylindrical knob or the like. According to such a configuration, when the positional relationship between the polarizer 22 and the liquid crystal panel 16 is shifted due to a manufacturing error, vehicle vibration, or the like, the reflection axis of the polarizer 22 is rotated by the first oscillating unit, and the light source Adjustment to align the axial direction with the polarization axis of light can be performed.

  In addition, the polarizer 22 can be driven to swing on the second swing shaft 34 in the horizontal direction of the vehicle 2. Specifically, although not shown, the second rocking shaft 34 has a second rocking portion that can be rocked. The second swing unit swings and drives the polarizer 22 in accordance with a drive signal from an electrically connected controller. By driving the polarizer 22 to swing, the projection position on the projection plane 5 is raised and lowered, and the imaging position of the virtual image 7 is adjusted up and down.

  The package 40 is formed in a hollow shape that accommodates the illumination optical system 10 and the imaging optical system 20, and is accommodated in the instrument panel 3 of the vehicle 2. The package 40 has an opening window 42 that opens upward between the polarizer 22 of the imaging optical system 20 in the package 40 and the projection surface 5 of the windshield 4 outside the package 40. The light source light reflected by the polarizer 22 passes through the aperture window 42 from the polarizer 22 and is projected toward the upper projection plane 5.

  The package 40 has a heat radiating member 44. The heat radiating member 44 is disposed on the opposite side of the incident surface 28 of the polarizer 22 in a part of the package 40 that is spaced from the illumination optical system 10 and the imaging optical system 20. The heat radiating member 44 is formed, for example, by having a serrated irregularity 440 on the inner wall of the package 40 and applying a black light-absorbing paint 442 that absorbs light to the surface of the irregularity 440.

  Below, control of the disturbance light which injects into the HUD apparatus 1 in this embodiment is demonstrated using FIG. The disturbance light is, for example, sunlight, and enters the opening window 42 of the HUD device 1 directly from outside the vehicle 2 or through the windshield 4. The disturbance light is incident on the aperture window 42 at any angle from any direction. FIG. 5 shows an example of the incident angle.

  The disturbance light shown as an example in FIG. 5 is incident on the interior of the vehicle 2 by passing through the windshield 4 from the outside of the vehicle 2. The disturbance light enters the HUD device 1 through the opening window 42. As described above, since the aperture window 42 is disposed between the polarizer 22 of the imaging optical system 20 and the projection surface 5 of the windshield 4, disturbance light continues to travel straight in a non-polarized state and is polarized. It reaches the incident surface 28 of the child 22.

  Since the unpolarized disturbance light incident on the incident surface 28 of the polarizer 22 is considered to be a mixture of various polarized lights, it is divided into transmitted light and reflected light depending on the characteristics of the polarizing film 26 described above. Specifically, a part (for example, 50%) is transmitted through the polarizing film 26 and the other part is reflected by the polarizing film 26.

  The disturbance light transmitted through the polarizing film 26 further passes through the base material 24 and enters the heat radiating member 44 disposed on the opposite side of the incident surface 28 of the polarizer 22.

  The disturbance light incident on the heat radiating member 44 is efficiently absorbed by the light absorbing paint 442 of the heat radiating member 44 having a large surface area and converted into heat. The converted heat is radiated to the outside of the HUD device 1 through the outer wall of the package 40.

  Thus, the polarizer 22 blocks part of the disturbance light from the optical path of the light source light, thereby reducing disturbance light that is unintentionally scattered in the HUD device 1.

  Moreover, the disturbance light reflected by the polarizing film 26 may be scattered in an unintended direction and overlap with the light source light, as in the conventional HUD device 1. Specifically, as shown in FIG. 5, disturbance light is scattered on the surface of the liquid crystal panel 16, and a part of the light coincides with the light source light. Such disturbance light is reflected by the polarizer 22 again, passes through the opening window 42, is further reflected by the projection surface 5, and reaches the eye point 6 of the vehicle occupant.

  The disturbance light reflected by the projection surface 5 and reaching the eye point 6 is visually recognized by interfering with the light source light beam forming the virtual image 7. For example, disturbance light is visually recognized as a ghost or flare in the virtual image 7. For example, disturbance light is visually recognized as background light in the virtual image 7.

  Here, the influence of background light on the virtual image 7 will be described. The background light affects the contrast of the virtual image 7. The contrast is a ratio of the luminance of the on-state pixel and the luminance of the off-state pixel in the virtual image 7.

For example, assume that the luminance of the pixel in the on state by the light source light is 10,000 cd / m ² and the luminance of the pixel in the off state by the light source light is 1 cd / m ² . If background light due to disturbance light is added and its luminance (hereinafter referred to as background luminance) is 10 cd / m ² , the background luminance is added to the entire virtual image 7 regardless of the on state and the off state. The luminance of the visually recognized pixel in the on state is 10,010 cd / m ² , and the visually recognized luminance of the off state pixel is 11 cd / m ² . At this time, the contrast of the virtual image 7 is 10,010: 11 = 910: 1.

On the other hand, when the polarizer 22 blocks part of the disturbance light from the optical path of the light source light, for example, when the background luminance is reduced to 5 cd / m ² , the luminance of the visually recognized pixel in the on state is 10,005 cd / ^{m 2,} the luminance of the pixels in the oFF state to be visually recognized becomes 6 cd / ^{m 2.} At this time, the contrast of the virtual image 7 is improved to 10,005: 6≈1668: 1.

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

  According to the first embodiment, since the polarizer 22 is provided in the imaging optical system 20 in which the disturbance light reaches before the illumination optical system 10, most of the disturbance light incident on the HUD device 1 is incident on the polarizer 22. Upon arrival, the polarizer 22 blocks a part of the reaching disturbance light. And the disturbance light which is scattered in the HUD apparatus 1 unintentionally decreases. According to this, it is possible to suppress occurrence of a ghost or flare in the virtual image 7 or a decrease in contrast due to an increase in background luminance of the virtual image 7. In addition, since the polarizer 22 is arranged with the axial direction aligned so as to guide the light source light to the projection surface 5, the luminance reduction of the light source light by the polarizer 22 can be suppressed. From the above, the HUD device 1 with good visibility of the virtual image 7 can be provided.

  Further, according to the first embodiment, the light source light is reflected with a high reflectivity by the reflective polarizer 22 whose reflection axis is set in the coaxial direction with the polarization axis of the light source light. Therefore, the effect of suppressing the luminance reduction of the light source light by the polarizer 22 can be enhanced.

  Further, according to the first embodiment, disturbance light that reaches the polarizer 22 from outside the vehicle 2 is transmitted light that is not absorbed by the polarizer 22 and reflected light that is reflected by the polarizer 22. And divided. Therefore, since heat generation of the polarizer 22 main body due to absorption of disturbance light is suppressed, a reduction in the product life of the HUD device 1 can be suppressed.

  Further, according to the first embodiment, the disturbance light transmitted through the polarizer 22 is converted into heat by the heat radiating member 44 and is radiated, so that the heat is prevented from staying in the illumination optical system 10 and the imaging optical system 20. Thus, it is possible to enhance the effect of suppressing the decrease in the product life of the HUD device 1.

  Further, according to the first embodiment, the polarizer 22 guides the light source light to the projection surface 5 by the curved incident surface 28 whose axial direction is aligned with the light source light. Accordingly, the imaging state of the virtual image 7 by the light source light can be adjusted. From the above, the HUD device 1 with good visibility of the virtual image 7 can be provided.

  Further, according to the first embodiment, even if a deviation occurs in the positional relationship between the illumination optical system 10 and the polarizer 22 due to a manufacturing error or the like, the light source light is projected onto the projection surface by the polarizer 22 that can be driven to swing. The axial direction of the light source light can be adjusted so that the light is guided to 5.

  Further, according to the first embodiment, the polarizer 22 blocks a part of the disturbance light that reaches the polarizer 22, and also functions as a reflecting mirror that guides the light source light to the projection surface 5. Therefore, an increase in the number of parts of the imaging optical system 20 can be suppressed.

(Second Embodiment)
As shown in FIG. 6, the second embodiment of the present invention is a modification of the first embodiment. The second embodiment will be described with a focus on differences from the first embodiment.

  The imaging optical system 2020 of this embodiment includes a concave mirror 2036 in addition to the polarizer 2022. The light source light projected by the illumination optical system 10 is incident on the incident surface 2028 of the polarizer 2022.

  The polarizer 2022 of this embodiment has a planar incident surface 2028. The arrangement direction of the metal wires 30 formed by the polarizing film 26 is formed in the same direction at an arbitrary position on the incident surface 2028. That is, the reflection axis is coaxial with an arbitrary portion of the incident surface 2028. In the case where the polarizing film 26 is attached to the planar base material 2024 as in the present embodiment, the polarizing film 26 is unlikely to be bent, and thus the arrangement direction of the metal wires 30 is formed in the same direction at an arbitrary position. Is easy.

  According to this, when the light source light is incident on the polarizer 2022 as a light beam, even if the light source light is incident on the peripheral portion of the polarizer 2022, the reflection axis is in the same direction at any position on the incident surface 2028. The deviation between the polarization axis and the reflection axis is unlikely to occur. That is, the light source light incident on the central portion of the polarizer 2022 and the light source light incident on the peripheral portion of the polarizer 2022 are reflected by the polarizer 2022 with a difference in reflectance being suppressed.

  Further, the polarizer 2022 has a first swinging portion that can be driven to swing around the first swinging shaft 32 perpendicular to the incident surface, for example, as in the first embodiment.

  Such a polarizer 2022 is arranged in consideration of the space in the package 40 and reflects the light source light from the illumination optical system 10 toward the concave mirror 2036. That is, the polarizer 2022 projects the light source light onto the concave mirror 2036 while bending the optical path of the imaging optical system 20 so that the HUD device 1 can be miniaturized.

  The concave mirror 2036 is formed by applying an aluminum mirror coat for depositing aluminum as the reflective surface 2038 on the surface of a base material made of synthetic resin or glass. The reflecting surface 2038 is formed in a smooth curved surface as a concave surface in which the central portion of the concave mirror 2036 is recessed. With this shape, the concave mirror 2036 adjusts the imaging state of the virtual image 7 by reflecting the light source light from the polarizer 2022 toward the projection surface 5 of the vehicle 2.

  The concave mirror 2036 can be driven to swing on the second swing shaft 2034 in the horizontal direction of the vehicle 2. Specifically, although not shown, it has a second oscillating portion that can be oscillated on a second oscillating shaft 2034 in the horizontal direction of the vehicle. The second swing unit swings and drives the concave mirror 2036 in accordance with a drive signal from an electrically connected controller. By swinging and driving the concave mirror 2036, the projection position on the projection plane 5 is raised and lowered, and the imaging position of the virtual image 7 is adjusted up and down.

(Function and effect)
In the second embodiment described above, the polarizer 2022 of the imaging optical system 2020 is the same as that in the first embodiment with respect to the control of incident disturbance light. Therefore, also in the second embodiment, the effects common to the first embodiment can be exhibited in the configuration common to the first embodiment.

  In addition, according to the second embodiment, the polarizer 2022 having the planar incident surface 2028 can easily form the reflection axis in the coaxial direction at an arbitrary position on the incident surface. Even if it is the light source light which injects into, a shift | offset | difference of a polarization axis and a reflection axis does not arise easily. Therefore, by suppressing luminance unevenness between the center and the outer periphery of the virtual image 7, the HUD device 1 with good visibility of the virtual image 7 can be provided.

(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 these embodiments, and various embodiments and combinations can be made without departing from the scope of the present invention. Can be applied.

  Specifically, in the first modification, the polarizers 22 and 2022 do not have to be reflective. For example, the polarizers 22 and 2022 may be of an absorption type having a transmission axis that is the direction in which the transmittance is maximum and an absorption axis that is the direction in which the absorption rate is maximum. In this example, the absorptive polarizers 22 and 2022 are arranged with the transmission axis aligned with the polarization axis of the light source light so as to guide the light source light to the projection plane 5.

  In the second modification, the reflection axes of the polarizers 22 and 2022 may be shifted as long as the axial directions match so as to guide the light source light to the projection plane 5. For example, even if the reflection axis and the polarization axis are deviated by 5 degrees, as described above, the reflectance of the light source light by the polarizers 22 and 2022 hardly decreases, and the same effect can be obtained.

  In the third modification, the polarizers 22 and 2022 may not divide the disturbance light reaching from the outside of the vehicle 2 into transmitted light and reflected light. For example, the polarizers 22 and 2022 are formed by attaching a polarizing film 26 as the incident surfaces 28 and 2028 to one surface of a base material 24 formed in a light-absorbing plate shape that absorbs light. It may be. In this example, part of the disturbance light reaching the incident surfaces 28 and 2028 of the polarizers 22 and 2022 is transmitted through the polarizing film 26 and absorbed by the base material.

  In the fourth modification, the HUD device 1 does not need to include the heat radiating member 44 that converts the disturbance light transmitted through the polarizers 22 and 2022 into heat and radiates heat.

  In the fifth modification, the polarizers 22 and 2022 may not be swingable.

  In Modification 6, the present invention may be applied to various mobile bodies (transport equipment) such as ships or airplanes other than the vehicle 2.

  DESCRIPTION OF SYMBOLS 1 Head-up display apparatus (HUD apparatus), 2 vehicles, 4 Windshield, 5 Projection surface, 7 Virtual image, 10 Illumination optical system, 16 Liquid crystal panel, 20, 2020 Imaging optical system, 22, 2022 Polarizer, 28, 2028 Incident surface, 32 first swing shaft, 44 heat dissipation member

Claims (7)

Installed in the moving body (2),
An illumination optical system (10) for projecting an image as linearly polarized light source light;
An imaging optical system (20, 2020) that forms the image as a virtual image (7) by projecting the light source light projected by the illumination optical system onto a projection surface (5) of the moving body, Prepared,
A head-up display device that displays the virtual image so as to be visible from a room of the moving body,
The imaging optical system includes a polarizer (22, 2022) disposed in alignment with the light source light so as to guide the light source light to the projection surface. Head-up display device. The polarizer is a reflective type,
The head-up display device according to claim 1, wherein a reflection axis of the polarizer is set in a direction coaxial with a polarization axis of the light source light.   The head-up display device according to claim 1, wherein the polarizer divides disturbance light reaching from the outside of the moving body into transmitted light and reflected light.   The head-up display device according to claim 3, further comprising a heat radiating member (44) that converts the disturbance light transmitted through the polarizer into heat to radiate heat.   The said polarizer is arrange | positioned according to the axial direction with respect to the said light source light so that the said light source light may be guided to the said projection surface, and has a planar incident surface (2028), It is characterized by the above-mentioned. 5. The head-up display device according to any one of 1 to 4.   The said polarizer is arrange | positioned according to the axial direction with respect to the said light source light so that the said light source light may be guided to the said projection surface, and has a curved-surface incident surface (28), It is characterized by the above-mentioned. 5. The head-up display device according to any one of 1 to 4.   7. The polarizer according to claim 1, wherein the polarizer can be driven to swing so as to align the axial direction of the light source light so as to guide the light source light to the projection surface. 2. A head-up display device according to item 1.

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