JP2016042188A - Image display device and image display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device and an image display method for providing high display quality.SOLUTION: An image display device 100 according to an embodiment of the present invention includes: a projector 20 that emits image display light L1 polarized to a predetermined polarization state to project an image according to an image signal; a screen 50 on which the image display light from the projector 20 is formed into an intermediate image; and a polarizing plate 51 that is arranged on a light path between the projector 20 and screen 50 to transmit light according to the polarization state of the incident light. The polarizing plate 51 is arranged so that at least a part of the light path of the light reflected on the polarizing plate 51 does not coincide with a light path of light constituting a virtual image.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image display device and an image display method, and more particularly to an image display device and an image display method for presenting a virtual image based on an intermediate image formed on a screen to a user.

  In recent years, so-called head-up displays using LEDs or semiconductor laser light sources have been developed as vehicle display devices. For example, Patent Document 1 discloses a head-up display including a display that projects signal light, a mirror, and a combiner. In this head-up display, the light projected from the display device is reflected by a mirror and enters the combiner. And an observer can recognize a virtual image by observing a display image through a combiner.

JP-A-10-138794

  In the head-up display of Patent Document 1 described above, a polarizing plate is provided between the mirror and the combiner. However, in this configuration, there is a possibility that the contrast of the recognized virtual image is lowered by the reflected light reflected by the polarizing plate.

  In view of the above problems, an object of the present invention is to provide an image display device and an image display method that allow a user to recognize a higher quality image.

An image display device according to an aspect of the present invention includes a projector that emits image display light polarized in a predetermined polarization state and projects an image according to an image signal, and an image display light emitted from the projector. An intermediate image screen on which an image is formed, and a polarizing element that is disposed in an optical path between the projector and the intermediate image screen and transmits light according to a polarization state of incident light. Based on the emitted image display light, the polarizing element is arranged so that the virtual image reflected by the intermediate image screen and the position of the virtual image reflected by the polarizing element do not overlap.
An image display method according to an aspect of the present invention includes a step of emitting image display light polarized in a predetermined polarization state from a projector, and image display light emitted from the projector according to a polarization state of incident light. Incident light is incident on a polarizing element; incident image display light incident on the polarizing element is incident on an intermediate image screen to form an intermediate image on the intermediate image screen; and reflected by the intermediate image screen Displaying the light based on the intermediate image as a virtual image, and based on the image display light emitted from the projector, the virtual image reflected by the intermediate image screen and the position of the virtual image reflected by the polarizing element The polarizing elements are arranged so that they do not overlap with each other.

  ADVANTAGE OF THE INVENTION According to this invention, the image display apparatus and image display method which a user can recognize a higher quality virtual image can be provided.

The figure which shows typically the motor vehicle carrying the image display apparatus concerning this Embodiment. It is a schematic diagram for demonstrating the optical path of a light beam. It is a side view which shows typically the structure of the image display apparatus concerning this Embodiment. It is a figure which shows the optical system of the projector of the image display apparatus concerning this Embodiment. It is a side view for demonstrating arrangement | positioning of the polarizing plate of the image display apparatus concerning this Embodiment. It is a side view which shows the structure of the image display apparatus concerning this Embodiment. It is a perspective view which shows the structure of the image display apparatus concerning this Embodiment.

<overall structure>
Embodiments of the present invention will be described below with reference to the drawings. In the following description, the image display device according to the present embodiment is described as a head-up display mounted on a dashboard of an automobile, but the present invention is not limited to this. The image display device may be attached to a place other than the dashboard. For example, the image display device may be attached to a vehicle rearview mirror or sun visor. Furthermore, the image display device may be attached to a vehicle other than an automobile, a vehicle other than the vehicle, or may be attached to another vehicle or the like.

  FIG. 1 is a diagram schematically showing a typical use example of an image display apparatus 100 assumed by the present invention. The image display device 100 is mounted on the dashboard 10 of the automobile 1. In FIG. 1, the driver P is an observer. The image display light L1 generated and adjusted so as to display a desired image is emitted from the image display device 100.

The image display light L1 is emitted to a combiner (not shown in FIG. 1), then reflected on the combiner, enters the eyes of the driver P, and forms an image on the retina. At the same time, external light L2 from the outside is also incident on and transmitted through the windshield 11. Therefore, the external light L2 from the outside world and the image display light L1 from the image display device 100 are overlaid (superimposed), and a real scene of the outside world and an image generated by the image display device 100 are displayed in the field of view of the driver P. It will be visible at the same time.
In the following description, the description is based on the direction in a state where the image display device 100 is placed on the dashboard 10 of the automobile 1. That is, the direction of the automobile 1 is set as a reference direction. For example, the front glass 11 side will be described as the front, and the driver P side will be described as the rear. Similarly, the description will be made with the roof side of the automobile 1 as the upper side, the ground side as the lower side, and the lateral direction (left-right direction) of the automobile 1 as the side.

  Next, the optical path of the image display light L1 will be described with reference to FIG. FIG. 2 is a diagram illustrating an optical path of the image display light L1, and is a schematic view of the image display device 100 and its periphery viewed from the side. The image display apparatus 100 includes a projector 20, a screen 50, and a combiner 60. The projector 20 includes a projector body 40 and a projection lens 32. By using the projector 20, a small and high-definition image can be displayed. In FIG. 2, the screen 50 and the projector 20 are attached to the plate 33. A plate 33 is placed on the dashboard 10.

  The projector main body 40 emits image display light L1 polarized in a predetermined polarization state. In addition, an image signal corresponding to a display image is input to the projector main body 40 from an external device. As an external device, an unillustrated car navigation device, a media playback device, or the like can be considered. Then, the projection lens 32 projects an image corresponding to the image signal onto the screen 50 by emitting image display light L1 based on the image signal onto the screen 50. In FIG. 2, the projector 20 emits light to the rear side of the automobile 1. An intermediate image R based on the image signal is formed on the screen 50 by the image display light L1 from the projector 20. As an example of the intermediate image, FIG. 2 shows a state in which an intermediate image R of an arrow indicating a left turn based on an image signal input from the car navigation apparatus is formed on the screen 50.

  A real image of the intermediate image R is formed on the screen 50. The intermediate image R projected on the screen 50 may be information related to driving, for example, an arrow for car navigation, a driving speed, or the like. Alternatively, navigation map information or road congestion information received via radio may be used as the intermediate image R.

  The screen 50 is a reflective diffusion screen. Accordingly, the image display light L1 incident on the screen 50 is diffusely reflected. As the screen 50 that is a reflective diffusion screen, for example, a screen whose surface is roughened, a bead screen, or a hologram screen can be used. The projector 20 enlarges and projects the intermediate image R on the surface of the screen 50. The screen 50 reflects the image display light L1 in front of the automobile, that is, in the direction of the windshield 11.

  The image display light L <b> 1 reflected by the screen 50 is incident on the combiner 60. For example, the combiner 60 is formed from a concave half mirror. More specifically, the combiner 60 is a concave meniscus half mirror having a radius of curvature of 400 mm.

  The combiner 60 transmits part of the incident light and reflects the rest. The combiner 60 reflects a part of the image display light L1 incident from the screen 50 in the direction of the driver P. The combiner 60 displays the virtual image I related to the intermediate image R by the image display light L <b> 1 reflected by the screen 50. As a result, the driver P magnifies and observes the virtual image I in front of the windshield 11. The driver P can recognize the virtual image I through the windshield 11 and the combiner 60. The driver P can see the intermediate image R as if it were in the front space of the windshield 11. For example, the virtual image I is formed 1-2 m ahead of the driver P. Accordingly, the driving information can be confirmed without the driver P turning away from the front.

  External light from the sun 70 may be directly inserted into the screen 50 through the windshield 11. External light incident on the screen 50 is diffusely reflected by the screen 50. When outside light other than the image display light L1 is diffusely reflected by the screen 50, it becomes noise light, and the contrast of the image recognized based on the image display light L1 is lowered. That is, the external light diffusely reflected by the screen 50 is reflected by the combiner 60 and enters the driver P's pupil. In particular, since sunlight has high brightness, when sunlight directly enters the screen 50, the driver P has difficulty in seeing (recognizing) the virtual image I.

  Therefore, the image display device 100 according to the present embodiment includes a polarizing plate 51 as shown in FIG. The polarizing plate 51 is disposed in the optical path of the image display light L 1 from the screen 50 to the combiner 60. Here, the polarizing plate 51 is attached to the front surface of the screen 50.

  The polarizing plate 51 is a polarizing element that transmits light according to the polarization state of incident light. For example, the polarizing plate 51 transmits a linearly polarized light component in a direction that coincides with the transmission axis. Therefore, the polarizing plate 51 reflects or absorbs unnecessary polarized light. The image display light L1 emitted from the projector main body 40 is linearly polarized light. The arrangement direction of the polarizing plate 51 is matched with the polarization direction of the image display light L1. That is, on the plane perpendicular to the optical axis of the projection lens 32, the polarization axis of the linearly polarized image display light L 1 is parallel to the transmission axis of the polarizing plate 51. Accordingly, most of the image display light L 1 incident on the screen 50 passes through the polarizing plate 51. Most of the image display light L1 emitted from the projector main body 40 passes through the polarizing plate 51 and enters the screen 50. Then, most of the image display light L 1 diffusely reflected by the screen 50 passes through the polarizing plate 51 and enters the combiner 60.

  On the other hand, the external light L2 emitted from the sun 70 is non-polarized light. For this reason, the polarizing plate 51 absorbs or transmits almost half of the external light L2. For example, it is assumed that the polarizing plate 51 is a reflective polarizing plate 51. In this case, almost half of the external light L2 is reflected by the surface of the polarizing plate 51 and travels downward. Then, the external light L2 enters the plate 33. Accordingly, the external light L2 reflected by the polarizing plate 51 deviates from the optical path of the image display light L1. When the polarizing plate 51 is an absorption-type polarizing plate, almost half of the external light L2 is absorbed by the polarizing plate 51. Almost half of the external light L2 does not contribute to the formation of the virtual image I by the image display light L1. Thereby, the influence of the external light L2 can be reduced and the virtual image I can be displayed with high contrast.

<Optical System of Projector 20>
Next, the optical system of the projector 20 will be described with reference to FIG. As shown in FIG. 4, the projector main body 40 includes a light source 21, a collimator lens 22, a filter 23, a reflective polarizing plate 24, a fly-eye lens 25, a reflective plate 26, a field lens 27, a reflective polarizing plate 28, and a phase compensation plate. 29, a display element 30, an analyzer 31, and a projection lens 32. For example, the display element 30 is a reflective liquid crystal display element such as an LCOS (Liquid Crystal On Silicon) device. Note that a DMD (Digital Micromirror Device) or the like may be used as the display element 30. In that case, the optical system and the drive circuit are configured according to the display element that requires liquid.

  The light source 21 includes, for example, an LED (Light Emitting Diode). Specifically, the light source 21 has a blue LED element that emits light having a wavelength of 430 to 440 nm. Furthermore, the light source 21 has a phosphor such as YAG (Yttrium Aluminum Garnet). And the light inject | emitted from the blue LED element injects into fluorescent substance. The phosphor emits fluorescence corresponding to incident light. When blue light is incident on the phosphor, the phosphor emits fluorescent light having a wavelength longer than that of the blue light (for example, green to red). More specifically, fluorescence with a wavelength of 550 ± 50 nm is generated. The light source 21 may be a white LED that is used in general lighting applications. The light source 21 emits light having a divergence angle of ± 90 °, for example.

  The collimator lens 22 turns the light from the light source 21 into a substantially parallel light beam. Here, an example in which three collimator lenses 22 are provided is shown, but the number of collimator lenses 22 is not particularly limited. Here, the number of collimator lenses 22 may be one, two, or four or more. The light from the collimator lens 22 enters the filter 23.

  The filter 23 is a wavelength filter that cuts light according to the wavelength. Specifically, the filter 23 reflects infrared light and ultraviolet light and transmits visible light. Therefore, only visible light enters the subsequent projection optical system. For example, a dichroic filter can be used as the filter 23.

  Visible light that has passed through the filter 23 enters the reflective polarizing plate 24. The reflective polarizing plate 24 transmits light according to the polarization state of light. The reflective polarizing plate 24 transmits linearly polarized light components in the direction of the transmission axis and reflects other polarized light components. Therefore, the light that has passed through the reflective polarizing plate 24 becomes linearly polarized light. That is, the light transmitted through the filter 23 becomes linearly polarized light with the direction of the transmission axis as the polarization axis of the reflective polarizing plate 24.

  Here, the light that has become a parallel light bundle by the collimator lens 22 is incident on the filter 23. Accordingly, the light reflected by the filter 23 is returned to the direction of the collimator lens 22. The return light from the collimator lens 22 enters the phosphor of the light source 21. The ultraviolet light incident on the phosphor has a different wavelength in the phosphor and enters the collimator lens 22. That is, visible light fluorescence is emitted from the light source 21 by the ultraviolet light cut by the filter 23. Then, the fluorescence of visible light becomes a parallel light bundle by the collimator lens 22. By using such a configuration, the light cut by the filter 23 can be reused.

  Further, light other than a predetermined polarization component is returned to the filter 23 by the reflective polarizing plate 24. Therefore, the light reflected by the reflective polarizing plate 24 enters the phosphor of the light source 21 through the reflective polarizing plate 24 and the filter 23. When fluorescence is generated, the polarization state of the return light changes. Accordingly, the light reflected by the reflective polarizing plate 24 enters the phosphor of the light source 21. Longer wavelength fluorescence is emitted and this fluorescence includes visible light. Then, the visible light fluorescence enters the reflective polarizing plate 24 again via the collimator lens 22 and the filter 23. By using such a configuration, the light reflected by the reflective polarizing plate 24 can be reused.

  As described above, the filter 23 is disposed after the collimator lens 22, and the reflective polarizing plate 24 is disposed immediately after the filter 23. With such a configuration, it is possible to return light to the LED phosphor with high efficiency, and the luminance of the image display light L1 can be increased by reuse. Therefore, improvement in brightness and power saving can be realized. Further, the light that has become a substantially parallel light beam by the collimator lens 22 is incident on the filter 23 and the reflective polarizing plate 24. Therefore, the return light from the filter 23 and the reflective polarizing plate 24 can be efficiently incident on the phosphor. With this configuration, the luminance can be improved by about 20%.

  The light that has been linearly polarized by the reflective polarizing plate 24 enters the fly-eye lens 25. The fly-eye lens 25 is a lens body in which identical single lenses are arranged in an array. The fly-eye lens 25 collects light in order to efficiently use light on the display element 30. For example, the fly-eye lens 25 has a single lens corresponding to the pixel of the display element 30. Thereby, light can be condensed on each pixel on the display element 30. The fly-eye lens 25 is made of a resin such as polycarbonate. The light whose ultraviolet light has been cut by the filter 23 enters the fly-eye lens 25. A fly-eye lens 25 is disposed after the filter 23. With the above configuration, the fly-eye lens 25 formed of polycarbonate or the like can be prevented from being deteriorated by ultraviolet light.

  The light transmitted through the fly-eye lens 25 is reflected by the reflecting plate 26 and enters the field lens 27. It should be noted that the reflector 26 can be omitted depending on the space where the projector 20 is installed. The field lens 27 refracts the light from the reflection plate 26 and efficiently enters the display element 30. FIG. 4h shows a configuration in which two field lenses 27 are provided, but the number of field lenses 27 is not particularly limited. For example, a configuration using one field lens 27 may be used.

  Light from the field lens 27 enters the reflective polarizing plate 28. The reflective polarizing plate 28 is a polarizing element similar to the reflective polarizing plate 24 and transmits light according to the polarization state. That is, the reflective polarizing plate 28 transmits linearly polarized light components in the direction of the transmission axis and reflects other polarized light components. The reflective polarizing plate 28 is installed so that the linearly polarized light transmitted through the reflective polarizing plate 24 is transmitted through the reflective polarizing plate 28. That is, in the optical system, the transmission axes of the reflective polarizing plate 24 and the reflective polarizing plate 28 coincide. Thereby, light can be used efficiently.

  The light that has passed through the reflective polarizing plate 28 enters the display element 30 via the phase compensation plate 29. The display element 30 is, for example, an LCOS device. The display element 30 includes a silicon substrate 30b provided with a pixel electrode and a counter substrate 30a provided with a counter electrode. For example, the counter substrate 30a is formed of a glass substrate that transmits light. A liquid crystal layer is sandwiched between the counter substrate 30a and the silicon substrate 30b. In a typical example, the display element 30 is a reflective liquid crystal panel having 800 × 600 pixels and a diagonal of 0.36 inches.

  For example, the pixel electrode is formed of an aluminum electrode that reflects light. The counter electrode is formed of a transparent conductive film that transmits light. Therefore, the light that has passed through the counter substrate 30a is reflected by the pixel electrode. Furthermore, pixels having TFTs and the like are arranged in an array on the silicon substrate 30b. By supplying an image signal to the display element 30, a desired voltage is applied to each pixel electrode. Thereby, the liquid crystal layer is driven according to the image signal. Here, the polarization state of light changes according to the state of the liquid crystal layer. The display element 30 modulates light according to the input image signal and changes the polarization direction. The light reflected by the display element 30 is reflected in a polarization state corresponding to the image signal.

  The light reflected by the display element 30 enters the reflective polarizing plate 28 via the phase compensation plate 29. The phase compensation plate 29 is a phase difference plate that compensates for a phase shift of light. For example, the phase compensation plate 29 corrects the difference in the polarization state due to the difference in the incident angle with respect to the display element 30. Thereby, contrast can be improved. As described above, the reflective polarizing plate 28 transmits the linearly polarized light component in the transmission axis direction and reflects light of other components. Since the display element 30 is reflected by changing the polarization state, the light from the display element 30 is reflected by the reflective polarizing plate 28. Therefore, the reflected light reflected by the reflective polarizing plate 28 is modulated according to the image signal. That is, the display element 30 controls the ratio of the component reflected in the direction of the projection lens 32 by the reflective polarizing plate 28 and the component transmitted through the reflective polarizing plate 28. The light that has passed through the reflective polarizing plate 28 has a gradation corresponding to the image signal.

  The light reflected by the reflective polarizing plate 28 is made high contrast by the analyzer 31 and enters the projection lens 32. The analyzer 31 is inclined with respect to the optical axis of the optical system. Therefore, even if the return light from the analyzer 31 is reflected by the display element 30, it passes outside the projection lens 32. Thereby, generation | occurrence | production of a ghost can be prevented.

  The projection lens 32 has a plurality of lenses, for example, and magnifies and projects an image from the projector main body 40 onto the screen 50. Here, the driver P can observe a virtual image enlarged to about 10 inches (25.4 cm) at a position 2 m away from the driver P. As described above, the projector 20 emits image display light polarized in a predetermined polarization state, and projects an image corresponding to the image signal. As described above, the intermediate image R is formed on the screen 50 by the image display light from the projector 20.

<Polarizing plate 51>
Next, the polarizing plate 51 arrange | positioned at the front side of the screen 50 is demonstrated using FIGS. FIG. 5 is a side view for explaining the optical path of the light bundle. FIG. 6 is a side view showing the arrangement of the polarizing plates 51 on the front side of the screen 50. FIG. 7 is a perspective view showing the arrangement of the polarizing plates 51 on the front side of the screen 50.

  As shown in FIGS. 6 and 7, the projector main body 40 is attached to the plate 33. In the present embodiment, for example, the plate 33 is fixed on the dashboard 10 of FIG. A screen 50 is fixed to the plate 33. For example, the screen 50 is erected vertically upward. Further, a polarizing plate 51 is disposed on the front surface of the screen 50.

  The polarizing plate 51 is attached to the screen 50 by a holder 52. The holder 52 fixes the polarizing plate 51 to the screen 50 so that the polarizing plate 51 is inclined with respect to the screen 50. That is, as shown in FIG. 6, the surface of the polarizing plate 51 is inclined from the surface of the screen 50. As shown in FIG. 6, the holder 52 has a wedge shape in a side view. By doing so, the surface of the polarizing plate 51 and the surface of the screen 50 do not become parallel. That is, the light reflecting surface that reflects the light of the polarizing plate 51 can be tilted with respect to the imaging surface of the screen 50.

  A combiner 60 is installed above the projector 20. The combiner 60 is attached to the plate 33 via the angle adjustment mechanism 61. The angle adjustment mechanism 61 adjusts the angle of the combiner 60. That is, the tilt angle of the combiner 60 is adjusted using the angle adjusting mechanism 61 as a rotation axis. Thereby, the formation position of the virtual image I with respect to the driver P can be changed. The driver P can observe the virtual image I at an appropriate position in accordance with the driver P and surrounding conditions. For example, the angle of the combiner 60 can be adjusted according to the sitting height of the driver P.

  Image display light L <b> 1 from the projector 20 enters the screen 50 via the polarizing plate 51. Here, the polarizing plate 51 is an absorption-type polarizing plate. Accordingly, the polarizing plate 51 transmits the linearly polarized light component parallel to the predetermined transmission axis and absorbs the other polarized light component. The transmission axis of the polarizing plate 51 corresponds to the transmission axis of the reflective polarizing plate 28. That is, the transmission axis of the polarizing plate 51 and the transmission axis of the reflective polarizing plate 28 are parallel, and the polarizing plate 51 transmits the linearly polarized image display light L1 from the projector 20. Thereby, the image display light L1 incident from the projector 20 can be efficiently used.

  A real image of the intermediate image R is formed on the screen 50 by the image display light L1 transmitted through the polarizing plate 51. Here, of the image display light L1 emitted from the projector 20, the image display light reflected by the screen 50 is referred to as an image display light L3. The image display light L3 reflected by the screen 50 enters the combiner 60 via the polarizing plate 51. A part of the image display light L3 incident on the combiner 60 is reflected in the direction of the driver P. Therefore, the combiner 60 displays the virtual image of the intermediate image R formed on the screen 50 in front of the driver P.

  A part of the image display light L 1 incident on the polarizing plate 51 from the projector 20 is reflected on the surface of the polarizing plate 51. Usually, the polarizing plate is formed of a parallel flat glass substrate, and has a surface reflectance of about several percent even when an antireflection film is applied. For example, the polarizing plate 51 is configured by adhering an absorption-type polarizing plate to a glass plate, and the glass plate has a surface reflectance of about 1 percent. Therefore, a part of the image display light L1 incident on the polarizing plate 51 from the projector 20 is reflected before being imaged on the screen 50. Here, of the image display light L1 emitted from the projector 20, light reflected by the polarizing plate 51 is referred to as reflected light L4. In FIG. 5, the reflected light L4 is indicated by a dotted line.

  When the reflected light L4 reflected by the polarizing plate 51 enters the combiner 60, the contrast of the virtual image recognized by the user is reduced. Therefore, in the present embodiment, the installation angle of the polarizing plate 51 is inclined from the angle of the surface of the screen 50. That is, the polarizing plate 51 is installed inclined from the angle of the surface of the screen 50. Here, it arrange | positions so that the surface of the polarizing plate 51 may face a lower side (projector 20 side). Therefore, the reflected light L4 of the polarizing plate 51 is incident on the lower side of the combiner 60, for example, the periphery between the combiner 60 and the projector 20.

  As a result, at least part of the optical path of the light beam reflected by the polarizing plate 51 deviates from the optical path of the light beam constituting the virtual image I. In other words, the screen 50 is arranged so that at least a part of the optical path of the light reflected by the polarizing plate 51 does not coincide with the optical path of the light constituting the virtual image I. Of the image display light L1 emitted from the projector 20, the light path of the reflected light L4 and the light path of the image display light L3 are branched. At least a part of the light beam of the reflected light L4 does not enter the combiner 60 but passes through the outside of the combiner 60. In other words, at least part of the reflected light L4 propagates outside the optical path from the combiner 60 to the driver P.

  Further, even if a part of the light beam of the reflected light L4 enters the combiner 60 and is reflected in the direction of the driver P, the direction of the reflected light L4 toward the driver P's pupil is on the driver P's pupil. It will deviate greatly from the direction of the image display light L3 which goes. The position of the virtual image (for example, the aperture of the projection lens 32) by the reflected light L4 is deviated from the position of the virtual image I by the image display light L3. For this reason, the driver | operator P can visually recognize an image in the state in which the virtual image by reflected light L4 and the position of the virtual image I by image display light L3 do not overlap. Therefore, it is possible to prevent a decrease in contrast of the virtual image of the intermediate image R due to the image display light L3. Thereby, the driver | operator P can visually recognize driving information reliably.

  Furthermore, it is preferable that the optical path of the light bundle of the reflected light L4 is deviated from the combiner 60. That is, the mounting angle of the polarizing plate 51 is set so that the entire light beam of the reflected light L4 does not enter the combiner 60. The polarizing plate 51 is arranged so that the combiner 60 is not positioned on the optical path of the light reflected by the polarizing plate 51. By doing so, the reflected light L4 from the polarizing plate 51 is not incident on the pupil of the driver P via the combiner 60. Thus, by passing the light bundle of the reflected light L4 through the outside of the combiner 60, the virtual image by the reflected light L4 is not visually recognized. Thereby, the contrast of the virtual image I by the image display light L3 can be increased. In particular, since the reflected light L4 due to the surface reflection of the polarizing plate 51 is not diffused, the brightness may be higher as a unit area than the image display light L3. Even in such a case, a decrease in contrast can be prevented.

  The image display device 100 is not limited to a normal automobile, and may be mounted on other vehicles such as other special vehicles. As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

DESCRIPTION OF SYMBOLS 1 Car 10 Dashboard 11 Windshield 20 Projector 21 Light source 22 Collimator lens 23 Filter 24 Reflective polarizing plate 25 Fly eye lens 26 Reflector 27 Field lens 28 Reflective polarizer 29 Phase compensation plate 30 Display element 31 Analyzer 32 Projection lens 33 Plate 40 Projector body 50 Screen 51 Polarizing plate 52 Holder 60 Combiner 61 Angle adjustment mechanism 100 Image display device

Claims (3)

A projector that emits image display light polarized in a predetermined polarization state and projects an image according to an image signal;
An intermediate image screen on which an intermediate image is formed by image display light emitted from the projector;
A polarizing element disposed in an optical path between the projector and the intermediate image screen and transmitting light according to a polarization state of incident light,
An image display in which the polarizing element is arranged so that the virtual image reflected by the intermediate image screen and the position of the virtual image reflected by the polarizing element do not overlap based on the image display light emitted from the projector apparatus. Arranged so that the surface of the polarizing element and the surface of the intermediate image screen are not parallel,
The image display light reflected by the surface of the intermediate image screen generates a virtual image at a position visually recognized by the user, and the image display light reflected by the surface of the polarizing element is a virtual image at a position shifted from the position visually recognized by the user. Generate
The image display device according to claim 1. Emitting image display light polarized in a predetermined polarization state from a projector;
Causing image display light emitted from the projector to enter a polarizing element that transmits light according to a polarization state of the incident light;
Causing the image display light incident on the polarizing element to enter an intermediate image screen to form an intermediate image on the intermediate image screen;
Displaying the light based on the intermediate image reflected by the intermediate image screen as a virtual image,
An image display in which the polarizing element is arranged so that the virtual image reflected by the intermediate image screen and the position of the virtual image reflected by the polarizing element do not overlap based on the image display light emitted from the projector Method.

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