JP7424888B2 - image display device - Google Patents

Description

The present invention relates to an image display device, and particularly to an image display device that superimposes and forms a plurality of images in the depth direction of space.

2. Description of the Related Art Conventionally, an instrument panel that displays illuminated icons has been used as a device for displaying various information in a vehicle. Additionally, as the amount of information to be displayed increases, it has also been proposed to embed an image display device in the instrument panel or to configure the entire instrument panel with an image display device.

However, since the instrument panel is located below the windshield of the vehicle, in order for the driver to visually check the information displayed on the instrument panel, the driver must move his line of sight downward while driving, which is not preferable. Therefore, a head-up display (hereinafter referred to as HUD) that projects an image onto the windshield so that the driver can read information when visually checking the front of the vehicle has also been proposed (for example, Patent Document 1 ). Such a HUD requires an optical device to project an image onto a wide area of the windshield, and it is desired that the optical device be made smaller and lighter.

On the other hand, as an image display device that projects light using a small optical device, a head-mounted HUD shaped like glasses is known (see, for example, Patent Document 2). A head-mounted HUD projects an image onto the viewer's retina by directly irradiating the viewer's eyes with light emitted from a light source.

Japanese Patent Application Publication No. 2018-118669 Special table 2018-528446 publication

However, with conventional head-mounted HUDs, although it is possible to display images superimposed on the background, the position of the image formed in the air (aerial image) is fixed within the viewer's field of view. The degree of freedom in display position was low. As a result, the aerial image may be displayed in an inappropriate position depending on the intended use of the viewer or the individual's preferences, making it difficult to provide an appropriate image viewing experience.

The present invention has been made in view of the above-mentioned conventional problems, and provides an image display device that is capable of changing the position of an image projected in space and improving the degree of freedom of display position. The purpose is to

In order to solve the above problems, an image display device of the present invention includes a first image projection unit that irradiates a first image, and a projection optical unit that projects light of the first image in a viewpoint direction. The projection is performed around the rotation axis so that the angle θ formed between the direction in which the light of the first image projected from the projection optical section travels and the direction of the central line of sight from the viewpoint is variable. The projection optical part includes a rotation holding part that holds the optical part so as to be rotatable laterally , and the projection optical part includes a dichroic mirror that selectively reflects the wavelength of the light emitted by the first image projection part. a first beam splitter that reflects part of the light emitted by the first image projection unit in a first direction and transmits the remaining light in a second direction; The dichroic mirror includes a reflecting section that reflects the light traveling in one direction to the first beam splitter, and the dichroic mirror forms an image in space of the light reflected by the reflecting section .

In such an image display device of the present invention, since the projection optical section is held rotatably in the side by the rotation holding section, the projection position in the air of the first image irradiated from the first image projection section is fixed. can be changed, and the degree of freedom in display position can be improved.

Further, in one aspect of the present invention, the first image projection section includes a laser light source section that irradiates laser light.

Further, in one aspect of the present invention, the rotational range of the rotation holding portion is such that the angle θ is in a range of −25 degrees to +25 degrees.

Further, in one aspect of the present invention, the rotation holding section includes a plurality of rotation shafts.

According to the present invention, it is possible to provide an image display device that can change the position of an image projected in space and can improve the degree of freedom of the display position.

FIG. 1 is a schematic plan view showing the configuration of an image display device 100 according to a first embodiment. It is a photograph showing the propagation of laser light inside the waveguide G. This is a schematic diagram showing the difference in imaging direction depending on the angle when light is reflected an odd number of times inside the waveguide G, and FIG. 3(a) shows the waveguide G rotated to the side opposite to the viewer. As an example, FIG. 3(b) shows an example in which the waveguide G is rotated toward the viewer side. This is a schematic diagram showing the difference in the imaging direction depending on the angle when light is reflected an even number of times inside the waveguide G, and FIG. 4(a) shows the waveguide G rotated to the side opposite to the viewer. As an example, FIG. 4(b) shows an example in which the waveguide G is rotated toward the viewer side. 1 is a photograph showing an example of an image display device 100. It is a photograph showing how the display position of the first image changes when the rotation angle θ is changed in the example. FIG. 7 is a schematic plan view showing how an image is formed in the air by an image display device 110 according to a second embodiment. 1 is a schematic plan view showing a configuration example of an image display device 110. FIG. FIG. 3 is a schematic perspective view showing a change in the imaging position when rotating the rotation support part ARM in the image display device 110. FIG.

(First embodiment)
Embodiments of the present invention will be described in detail below with reference to the drawings. Identical or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. FIG. 1 is a schematic plan view showing the configuration of an image display device 100 according to this embodiment. As shown in FIG. 1, the image display device 100 includes a first image projection section S, a lens section L, a waveguide section G, and a case section CS. The solid line arrows in the figure schematically indicate the paths of the light emitted from the first image projection section S. Moreover, the arrow shown by the broken line in the figure shows the direction in which the viewer visually recognizes the straight front in the horizontal direction as the front center direction.

The case part CS is a housing that accommodates and holds each part. In the example shown in FIG. 1, the first image projection section S, the lens section L, and one end of the waveguide section G are housed inside the case section CS. Further, the case portion CS rotatably holds one end of the waveguide portion G about the rotation axis AX, and corresponds to the rotation holding portion in the present invention. The structure for rotatably holding the waveguide G in the case CS is not particularly limited, and for example, a structure may be used in which a support shaft provided in the waveguide G is supported by a bearing provided in the case CS. Can be done.

The waveguide section G is a member that internally guides the light emitted from the first image projection section S and projects it toward the viewer's viewpoint, and corresponds to the projection optical section in the present invention. As shown in FIG. 1, one end of the waveguide G is held rotatably in the lateral direction about a rotation axis AX. Although the specific structure of the waveguide section G is not limited, it is preferable that the background (direction H1 in the figure) be made of a visible transparent material, and glass or resin material can be used. In the example shown in FIG. 1, the partial reflection section HM is shown as an optical element for extracting the light propagating within the waveguide G toward the viewpoint, but a diffraction grating or the like may be used.

The reflection section M is an optical element provided inside the waveguide section G to reflect light. In the example shown in FIG. 1, the waveguide G is formed into a flat plate shape, and the reflection part M is provided at an angle of 45 degrees with respect to the in-plane direction of the waveguide G. The angle is not limited to 45 degrees. The partial reflection section HM is an optical element provided inside the waveguide section G to reflect part of the light and transmit the remaining part. In the example shown in FIG. 1, the partial reflection section HM is provided at an angle of 45 degrees with respect to the in-plane direction of the waveguide section G, but the angle of the partial reflection section HM is not limited to 45 degrees.

The first image projection unit S is a device that irradiates light constituting an image, and projects the image to the viewer's eyes (viewpoint). In the example shown in FIG. 1, the first image projection section S uses a laser light source section that irradiates laser light, makes the light incident on the waveguide section G via the lens section L, and causes the light to enter the waveguide section G through the reflection section M and the partial reflection section S. The light reflected by portion HM is projected in the direction of the viewpoint.

The lens section L is an optical element that adjusts the path of the light emitted by the first image projection section S. The specific configuration of the lens portion L is not limited, and known lenses such as a collimating lens for collimating laser light, a convex lens, a concave lens, an aspherical lens, etc. can be used. Further, the lens portion L may include a plurality of lenses.

As shown in FIG. 1, in the image display device 100, the light including the first image emitted by the first image projection section S enters one end side of the waveguide section G via the lens section L, and is incident at a predetermined angle. The light incident on the reflection section M is reflected, propagates inside the waveguide section G, enters the partial reflection section HM, is re-reflected by the partial reflection section HM, and is projected toward the viewing point to be viewed by the viewer.

When the waveguide G is located perpendicular to the line of sight direction H1 as shown by the solid line in FIG. Reach the viewpoint along H1. Therefore, the viewer views the background in the line-of-sight direction H1 and the first image in a superimposed manner.

When the waveguide G is rotated by the angle θ as shown by the imaginary line in FIG. The light projected onto the viewpoint is in a direction inclined at a predetermined angle with respect to the line-of-sight direction H1. Therefore, the viewer visually recognizes the first image at a position shifted laterally from the background in the viewing direction H1. Here, the range of the angle θ is preferably a range of 25 degrees left and right from the viewer's viewpoint with respect to the center front direction (−25°≦θ≦25°). When the angle θ is larger than ±25°, the projection position of the first image changes greatly, making it difficult to maintain comfort in superimposed display with the background.

FIG. 2 is a photograph showing the propagation of laser light inside the waveguide G. As shown in FIG. In the figure, a rectangle drawn with a white broken line indicates a cross section of the waveguide G, and an arrow drawn with a white broken line indicates the traveling direction of light outside the waveguide G. As shown in the figure, a laser beam was applied from the lower left of the figure to the position of the circle drawn with a solid white line. Inside the waveguide G, the laser beam propagates to the right while being totally reflected on the main surface, and the light reflected by the partial reflection section HM is irradiated downward in the figure. Since the propagation of light inside the waveguide G is as shown in FIG. 2, by rotating the case CS shown in FIG. By changing the corner, the viewing direction of the first image can be changed.

FIG. 3 is a schematic diagram showing the difference in imaging direction depending on the angle when light is reflected an odd number of times inside the waveguide G. FIG. 3(a) shows the waveguide G on the side opposite to the viewer. FIG. 3B shows an example in which the waveguide G is rotated toward the viewer side. FIG. 4 is a schematic diagram showing the difference in imaging direction depending on the angle when light is reflected an even number of times inside the waveguide G. FIG. 4(a) shows the waveguide G on the side opposite to the viewer. FIG. 4(b) shows an example in which the waveguide G is rotated toward the viewer side. There is.

The broken line arrow in the figure indicates the path of light when the waveguide G has a rotation angle θ=0 degrees, and is the same as that shown by the solid line arrow in FIG. The solid arrows in the figure indicate the paths of the light emitted from the first image projection section S when the respective waveguide sections G rotate. Similarly to FIG. 1, the light incident on the reflection section M from below in the figure propagates within the waveguide G while being totally reflected on the main surface, reaches the partial reflection section HM, and is reflected at the partial reflection section HM. light is projected toward the viewpoint. Therefore, from the viewpoint, the first image appears to be displayed in the direction of the arrow indicated by the dashed line in the figure. Also in the example shown in FIG. 4(b), the direction in which the first image is viewed changes slightly in the lateral direction compared to the case where θ=0 degrees.

As shown in FIGS. 3(a)(b) and 4(a)(b), regardless of whether the light is reflected an odd number of times or an even number of times on the main surface of the waveguide G, The traveling angle of the light projected from the partial reflection section HM can be made different from the line-of-sight direction H1 shown in FIG. Furthermore, regardless of whether the direction of rotation of the waveguide G is on the viewer's side or on the opposite side from the viewer, the light can be projected onto the viewer's side at an angle different from the line-of-sight direction H1.

(Example)
FIG. 5 is a photograph showing an example of the image display device 100. The transparent plate-like member shown in the figure is the waveguide section G, and the black casing shown on the right side of the waveguide section G is the case section CS. The white solid line shown in the figure shows the inclination of the waveguide G when the rotation angle θ is changed from 0 degrees to 20 degrees around the rotation axis AX, and in the example shown in FIG. The waveguide G is located at the position of θ=0 degrees.

FIG. 6 is a photograph showing how the display position of the first image changes when the rotation angle θ is changed in the embodiment shown in FIG. In the photograph shown in the figure, a photograph was taken in which the line-of-sight direction H1 was visually recognized from the viewpoint, and the vicinity of the partial reflection portion HM is shown in an enlarged manner. The white rectangle shown in the figure is the first image projected from the first image projection unit S, and an outline triangle is attached to the lower right corner of the first image.

As shown in FIG. 6, by rotating the waveguide part G laterally about the rotation axis AX, the projection direction of the first image projected from the partial reflection part HM changes, and the viewing direction is changed. From the person's viewpoint, the viewing direction of the first image has changed.

As described above, in the image display device 100 of this embodiment, the waveguide G, which is a projection optical part, is held rotatably in the side by the case part CS, which is a rotation holding part, so that the first image The projection position in the air of the first image irradiated from the projection unit S can be changed, and the degree of freedom of the display position can be improved.

(Second embodiment)
Next, a second embodiment of the present invention will be described using FIGS. 7 to 9. Description of contents that overlap with those of the first embodiment will be omitted. FIG. 7 is a schematic plan view showing the configuration of the image display device 110 according to this embodiment. As shown in FIG. 7, the image display device 110 includes a first image projection section S1, a first beam splitter BS1, a second beam splitter BS2, a retroreflection section RR, a reflection section M, and a dichroic mirror DM. We are prepared. In the figure, the dashed line and the dashed-two dotted line schematically indicate the path of the light emitted from the first image projection unit S1.

In the image display device 100 shown in FIG. 7, the viewer views the first before image A1 and the first after image R1 projected from the first image projection unit S1 at different distances from the viewpoint in the depth direction. In FIG. 7, the direction in which the first before image A1 and the first after image R1 are lined up is the depth direction, the vertical direction perpendicular to the depth direction is the lateral direction, and the direction perpendicular to the depth direction and the lateral direction is the vertical direction. . Here, in FIG. 7, left and right are expressed toward the depth direction, which is the line of sight direction from the viewpoint, but the lateral direction and vertical direction are used to express the positional relationship in FIG. good.

The first image projection unit S1 is a device that emits light constituting an image, and projects an image at a predetermined distance from the viewer's eyes (viewpoint). The first image projection unit S1 is arranged to the right of the second beam splitter BS2, and irradiates light laterally to one surface of the second beam splitter BS2 (the surface facing the first beam splitter BS1). .

The configuration of the first image projection unit S1 is not limited, and a liquid crystal display device with a backlight, a self-luminous organic EL display device, a projector device using a light source and a modulation element, etc. can be used. The image projected by the first image projection unit S1 may be a still image or a moving image. Further, the first image projection section S1 may include an optical member such as a lens.

The first beam splitter BS1 is a member that transmits part of the incident light and reflects part of it, and can use a partial reflection plate on the surface of which a film for adjusting reflectance is formed. The first beam splitter BS1 is arranged at an angle of 45 degrees with respect to the lateral direction and the depth direction. Further, it is arranged at an angle of 45 degrees with respect to the optical axis of the light emitted from the first image projection section S1.

The second beam splitter BS2 is a member that transmits part of the incident light and reflects part of it, and can use a partial reflection plate on the surface of which a film for adjusting reflectance is formed. The second beam splitter BS2 is arranged so as to be inclined at an angle of 45 degrees with respect to the lateral direction and the depth direction. Further, it is arranged at an angle of 45 degrees with respect to the optical axis of the light emitted from the first image projection section S1. Further, the first beam splitter BS1 and the second beam splitter BS2 have opposite inclination directions, and are arranged to face each other so as to intersect at an angle of 90 degrees.

Here, an arbitrary balance can be selected for the light transmittance and reflectance of the first beam splitter BS1 and the second beam splitter BS2, but for example, the transmittance is set to 50% and the reflectance is set to 50%. In addition, although an example is shown in which the inclination angle of the first beam splitter BS1 and the second beam splitter BS2 is 45 degrees orthogonal, it is not appropriate to angles can be used.

The retroreflector RR is an optical member that reflects incident light while maintaining its condensing properties in the direction of incidence. A retroreflector can be used. The retroreflector RR is arranged to the right of the first beam splitter BS1, with its main surface facing in the left-right direction.

The reflection section M is an optical member that specularly reflects the incident light in the direction of incidence, and may be a mirror having a structure in which the surface of a plate-like member is mirror-finished. The reflecting section M is arranged in the depth direction along with the first beam splitter BS1 and the second beam splitter BS2, and is arranged with the main surface facing the depth direction. In FIG. 7, a flat plate is shown as the reflecting part M, but a concave mirror or a convex mirror may also be used.

The dichroic mirror DM is an optical member that reflects light of a specific wavelength and transmits light of other wavelengths. The dichroic mirror DM is arranged to the left of the retroreflector RR and the first beam splitter BS1, and is arranged tilted so as to be rotatable in the depth direction. In the example shown in FIG. 7, the dichroic mirror DM is one that reflects the wavelength of the light emitted from the first image projection unit S1 and transmits other visible light. As described later, the first front image A1 and the first rear image R1 are formed in space by the light reflected by the dichroic mirror DM, so the dichroic mirror DM constitutes the projection optical section in the present invention. There is.

Although not shown in FIG. 7, an imaging lens may be disposed between the first beam splitter BS1 and the dichroic mirror DM as part of the imaging optical system. The imaging lens is an optical member for focusing the light traveling from the first beam splitter BS1 on a predetermined position in space, and a plurality of lens groups may be used.

As shown in FIG. 7, the light emitted from the first image projection unit S1 reaches the first beam splitter BS1 after being reflected by the second beam splitter BS2. A portion of the light that has reached the first beam splitter BS1 is reflected and travels in the direction of the retroreflector RR, is re-reflected by the retroreflector RR, and enters the first beam splitter BS1 again. Here, as shown in FIG. 1, the light that has traveled with its optical length expanded until it reaches the retroreflector RR is treated as light whose optical length is reduced due to the retroreflection characteristics of the retroreflector RR. incident on . The light that has re-entered the first beam splitter BS1 passes through the first beam splitter BS1, is reflected by the dichroic mirror DM, and is focused at a first distance between the dichroic mirror DM and the viewpoint as a first previous image A1. imaged.

The remaining part of the light that has reached the first beam splitter BS1 is transmitted and travels in the direction of the reflection section M, is re-reflected by the reflection section M, and enters the first beam splitter BS1 again. The light re-entering the first beam splitter BS1 is reflected by the first beam splitter BS1, further reflected by the dichroic mirror DM, and travels toward the viewpoint. At this time, the light reflected by the reflection unit M, the first beam splitter BS1, and the dichroic mirror DM travels with its optical length expanded, so that from the viewer's perspective, the light is focused at a second distance behind the dichroic mirror DM. It is visible like a light that has traveled. Therefore, it can be considered that the first rear image R1 is formed behind the dichroic mirror DM.

The light formed as the first before image A1 and the first after image R1 reaches the viewer's eyes. Therefore, the viewer visually recognizes the first before image A1 and the first after image R1 in the air in the depth direction. In addition, even when a transmitting plate that transmits light from the background is placed in the line of sight direction from the viewer's viewpoint, the background can be viewed through the transparent plate while the light imaged in front of the dichroic mirror DM is displayed. The first before image A1 and the first after image R1 formed behind the dichroic mirror DM can be visually recognized.

Specific examples of the transparent plate include the display surface of another head-mounted display (HMD), the windshield of a vehicle, the shield of a helmet, and the like. Further, images may be displayed on these transmission plates using another display device.

Although FIG. 7 shows an example in which the second beam splitter BS2, first beam splitter BS1, and reflection section M are arranged in the depth direction, it is also possible to arrange the reflection section M and retroreflection section RR interchangeably. , the first before image A1 and the first after image R1 can be formed at the same position as shown in FIG. Furthermore, although FIG. 7 shows a configuration in which the light from the first image projection section S1 is reflected by the second beam splitter BS2 and reaches the first beam splitter BS1, the first image projection section S1 is It may be arranged in the depth direction so that the light transmitted through the second beam splitter BS2 reaches the first beam splitter BS1. Alternatively, a configuration may be adopted in which light is directly incident on the first beam splitter BS1 without using the second beam splitter BS2. Further, another image projection section may be provided, and light may be incident on the first beam splitter BS1 via the second beam splitter BS2 to form a plurality of front images and a plurality of rear images.

FIG. 8 is a schematic plan view showing a configuration example of the image display device 110. As shown in FIG. 8, the image display device 110 includes a first image projection section S1, a first beam splitter BS1, a second beam splitter BS2, a retroreflection section RR, a reflection section M, a dichroic mirror DM, It includes a shutter part SH, a case part CS, and a rotation support part ARM. Further, the dichroic mirror DM is held by the case part CS with the rotation axis AX1 as the rotation center, and the rotation support part ARM is held with the rotation axis AX2 as the rotation center. Therefore, the combination of the rotation support part ARM and the case part CS includes the rotation axis AX1 and the rotation axis AX2, and corresponds to the rotation holding part in the present invention.

The shutter section SH is an optical member disposed between the first beam splitter BS1 and the retroreflection section RR and between the first beam splitter BS1 and the reflection section M, and switches between passing and blocking light. The specific configuration of the shutter section SH is not limited, and known components such as an optical isolator, a liquid crystal shutter, and an iris can be used. Further, switching between opening and closing (passing and blocking) of the shutter section SH is controlled by a control section (not shown).

The case part CS is a housing that accommodates and holds each part. In the example shown in FIG. 8, the first beam splitter BS1, the second beam splitter BS2, the retroreflection section RR, the reflection section M, and the shutter section SH are housed inside the case section CS, and the first image projection The portion S1 and the dichroic mirror DM are held outside by a case portion CS.

The rotation support part ARM is a member that maintains the relative positional relationship of the first beam splitter BS1, the retroreflection part RR, the reflection part M, and the dichroic mirror DM, and is rotatable about the rotation axis AX2. This is a member installed in the. This embodiment shows an example in which the first image projection section S1 is also held by the rotation support section ARM.

Since the rotation support part ARM can rotate while maintaining the relative positional relationship of each part, it needs to be made of a material having a certain degree of rigidity. Although the specific material and shape of the rotation support part ARM are not limited, for example, metal, resin, paper, etc. can be used.

In this embodiment, the path of the light emitted by the first image projection unit S1 is the same as in the first embodiment, and the first previous image A1 is formed on the side closer to the viewer than the dichroic mirror DM, and the first previous image A1 is formed on the side closer to the viewer than the dichroic mirror DM. The first rear image R1 is formed on the side farther away than the first rear image R1. The image formed at this time is only the path of light when the shutter section SH is open (transmitted), and by controlling the opening and closing of the shutter section SH, the first front image A1 and the first rear image R1 can be selectively formed. can be imaged.

Specifically, when the shutter section SH provided between the first beam splitter BS1 and the retroreflection section RR is set to a transmitting state, and the shutter section SH provided between the first beam splitter BS1 and the retroreflecting section M is set to a blocking state, the first Only the previous image A1 is imaged. Conversely, if the shutter section SH provided between the first beam splitter BS1 and the retroreflection section RR is set to a blocking state, and the shutter section SH provided between the first beam splitter BS1 and the retroreflection section M is set to a transmitting state, the first beam splitter Only image R1 is formed.

As described above, in the image display device 110 of the present embodiment, the first front image A1 and the first rear image R1 are selectively formed by opening and closing the shutter section SH, and the viewer can see the first front image A1 or the first rear image R1. Either one of the first subsequent images R1 is visually recognized. In addition, even when a transmitting plate that transmits light from the background is placed in the line of sight direction from the viewer's viewpoint, the background can be viewed through the transparent plate while the light imaged in front of the dichroic mirror DM is displayed. The first before image A1 and the first after image R1 formed behind the dichroic mirror DM can be visually recognized.

As shown in FIG. 8, one end of the dichroic mirror DM is held within the case part CS so as to be rotatable laterally around a rotation axis AX1 within an angle θ1. The structure for rotatably holding the dichroic mirror DM in the case part CS is not particularly limited, and for example, a structure in which a support shaft provided on the dichroic mirror DM is supported by a bearing provided in the case part CS can be used. . As the dichroic mirror DM rotates around the rotation axis AX1, the incident angle of the light incident on the surface of the dichroic mirror DM from the first beam splitter BS1 changes, so that the first before image A1 and the first after image The imaging position of R1 also changes. Thereby, the projection position in the air of the first image irradiated from the first image projection unit S1 can be changed, and the degree of freedom of the display position can be improved.

Here, the range of the angle θ1 is preferably a range of 25 degrees left and right with respect to the front center direction from the viewer's viewpoint (−25°≦θ1≦25°). When the angle θ1 is larger than ±25°, the amount of line-of-sight movement for viewing the aerial images of the first before image A1 and the first after image R1 becomes large, and comfort can be maintained in superimposed display with the background. becomes difficult.

FIG. 9 is a schematic perspective view showing a change in the imaging position when the rotation support part ARM is rotated in the image display device 110. In FIG. 9, illustration of the first image projection section S1, first beam splitter BS1, second beam splitter BS2, retroreflection section RR, reflection section M, shutter section SH, and case section CS is omitted for simplicity. There is.

As shown in FIG. 9, the rotation support part ARM holds at least the dichroic mirror DM included in the projection optical part with the rotation axis AX2 as the rotation center, and rotates in the angular range of θ2 in the left-right direction (lateral direction). It is said to be rotatable. Here, the angular range of θ2 in the left-right direction is a range that is an angle of θ2 in the left-right direction in the lateral direction, with the direction in which the viewer sees directly in front in the horizontal direction from the viewer's viewpoint e as the front center direction. . Although FIG. 9 shows an example in which the rotational support part ARM is rotated to the right from the front center direction at an angle θ2, it also includes a case in which it is rotated to the left on the opposite side from FIG.

By rotating the rotation support part ARM around the rotation axis AX2, the first beam splitter BS1, second beam splitter BS2, retroreflection part RR, reflection part M, and dichroic mirror DM shown in FIG. The angle θ is varied while maintaining the relative positional relationship. Therefore, the imaging positions in the air of the first before image A1 and the first after image R1 irradiated from the first image projection section S1 also change by the angle θ2, similar to the rotation of the rotation support section ARM. Thereby, the viewer visually recognizes the aerial images of the first front image A1 and the first rear image R1 in a direction displaced by the angle θ from the front center direction.

Here, the range of the angle θ2 is preferably a range of 25 degrees left and right from the viewer's viewpoint e to the front center direction (−25°≦θ2≦25°). When the angle θ2 is larger than ±25°, the amount of line-of-sight movement for viewing the aerial images of the first before image A1 and the first after image R1 becomes large, and comfort can be maintained in superimposed display with the background. becomes difficult.

Further, it is preferable that the length of the rotation support part ARM is approximately the same as the length from the rotation axis AX2 to the dichroic mirror DM and the distance from the viewpoint e to the dichroic mirror DM. That is, it is preferable that the rotation axis AX2 and the viewpoint e are at the same position in the depth direction. As a result, the path of the light reflected by the dichroic mirror DM and traveling in the direction of the viewpoint e is displaced by an angle θ2 that is approximately the same as the rotation of the rotation support portion ARM. Therefore, the rotation of the rotation support part ARM and the displacement of the imaging positions of the first before image A1 and the first rear image R1 are linked, and the imaging positions of the first before image A1 and the first rear image R1 are changed. This can be achieved through intuitive movements.

If the dichroic mirror DM is moved in parallel, the distance and relative angle of the dichroic mirror DM seen from the viewpoint e will change. In this case, the path of the light reflected by the dichroic mirror DM is different from that shown in FIG. 7, and the display contents of the first before image A1 and the first after image R1 change from before the change.

In contrast, in the image display device 110, the movement of the dichroic mirror DM is not parallel movement in the left-right direction but rotational movement about the rotation axis AX2. As a result, the relative positional relationship and angular relationship of the projection optical units for forming the first front image A1 and the first rear image R1 are maintained as shown in FIG. 8, and the first front image A1 and the first rear image R1 are The imaging position of the first rear image R1 is maintained at a distance from the viewpoint e, and the display content of the aerial image can be maintained regardless of the rotation of the rotation support part ARM.

As described above, in the image display device 110 of the present embodiment, the dichroic mirror DM held by the rotation support part ARM is rotated by an angle θ2 around the rotation axis AX2, and the dichroic mirror DM is rotated by an angle θ2 around the rotation axis AX1. The DM can be rotated by an angle θ1. Since the rotation holding section is provided with a plurality of rotation axes in this way, the positions of the first before image A1 and the first rear image R1 to be imaged in space can be changed, further increasing the degree of freedom in the display position. It becomes possible to improve the performance.

Furthermore, as shown in FIG. 9, by separately providing a head-mounted display (HMD) or the like in the direction of the central line of sight from the viewpoint e, the display on the HMD and the imaging of the first before image A1 and the first after image R1 can be controlled. Can be done at the same time. At this time, by rotating the dichroic mirror DM around the rotation axis AX1 and rotating the rotation support part ARM around the rotation axis AX2, the first before image A1 and the first after image R1 are The imaging position can be changed laterally from the display on the HMD. Thereby, the display on the HMD and the display areas of the first before image A1 and the first after image R1 can be separated, making it easier to identify both separately.

Further, a configuration may be adopted in which a wavelength filter is combined with the dichroic mirror DM to cut unnecessary external light. The wavelength filter is an optical member that cuts ultraviolet light and/or infrared light, and a known film structure can be used as the wavelength filter. The dichroic mirror DM and the wavelength filter may be configured separately, or they may be combined and formed integrally. Furthermore, the light reflection characteristics of the dichroic mirror DM may be designed to reflect ultraviolet light and/or infrared light, and the dichroic mirror DM may also serve as a wavelength filter.

As a result, even if ultraviolet light or infrared light travels from the outside world toward viewpoint e, the wavelength filter cuts or reflects the ultraviolet light and infrared light, so that the ultraviolet light and infrared light reach viewpoint e. do not. Thereby, ultraviolet light and infrared light from the outside world can be prevented from directly entering the viewer's viewpoint e, and the viewer's eyes can be protected.

(Third embodiment)
In the second embodiment shown in FIGS. 8 and 9, an example is shown in which the end of the rotation support part ARM is the rotation axis AX2, but as shown in FIG. 8, the rotation support part ARM holds the case part CS. The entire case portion CS may be rotated by setting the position as the rotation axis AX2'.

In this case, the viewing direction of the first image can be changed simply by rotating the case part CS around the rotation axis AX2', so when the end of the rotation support part ARM is set as the rotation axis AX2 The amount of movement of the case portion CS and the dichroic mirror DM can be made smaller.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. are also included within the technical scope of the present invention.

100, 110...Image display device S, S1...First image projection section BS1...First beam splitter BS2...Second beam splitter RR...Retroreflection section M...Reflection section HM...Partial reflection section L...Lens section G...Wave guide Part DM... Dichroic mirror A1... First front image R1... First back image H1... View direction AX1, AX2... Rotation axis CS... Case part ARM... Rotation support part HMD... Head mounted display

Claims (4)

a first image projection unit that emits a first image;
An image display device comprising a projection optical section that projects light of the first image in a viewpoint direction,
The projection optical section is moved to the side about the rotation axis so that the angle θ formed between the direction in which the light of the first image projected from the projection optical section travels and the direction of the central line of sight from the viewpoint is variable. Equipped with a rotation holding part that holds it so that it can rotate in the direction ,
The projection optical section includes a dichroic mirror that selectively reflects the wavelength of the light emitted by the first image projection section,
a first beam splitter that reflects part of the light emitted by the first image projection unit in a first direction and transmits the remaining light in a second direction;
comprising a reflecting section that reflects the light that has traveled from the first beam splitter in one of the first direction or the second direction to the first beam splitter;
The image display device is characterized in that the dichroic mirror forms an image in space of the light reflected by the reflection section . The image display device according to claim 1 ,
The image display device is characterized in that the first image projection section includes a laser light source section that irradiates laser light. The image display device according to claim 1 or 2 ,
The image display device is characterized in that a rotation range of the rotation holding section is such that the angle θ is in a range of −25 degrees to +25 degrees. The image display device according to any one of claims 1 to 3 ,
An image display device, wherein the rotation holding section includes a plurality of rotation axes.