JP7373981B2 - 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, in conventional head-mounted HUDs, in order to irradiate multiple images and form the images by overlapping the optical axes using a beam splitter or half mirror, the image display section and wiring must be arranged according to the number of images. There is a problem in that it is necessary to perform drive control, making it difficult to save space and reduce weight.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an image display device that can form a plurality of images in the depth direction while saving space and reducing weight. With the goal.

In order to solve the above problems, the image display device of the present invention includes a first image projection section that irradiates a first image, a second image projection section that irradiates a second image, and a first image that is incident on a first surface. a first beam splitter that reflects light from the second image projection unit in a first direction and transmits light from the second image projection unit that is incident on a second surface in the first direction; and a first beam splitter that propagates in the first direction. The first image projection section and the second image projection section are connected by a flexible signal wiring, and the first image projection section and the second image projection section are connected to each other by a flexible signal wiring. The second image projection section is characterized in that it is driven by a signal input from a common image signal input section.

In such an image display device of the present invention, the number of parts and the number of wirings can be reduced by driving the first image projection section and the second image projection section with signals input from a common image signal input section. This makes it possible to form multiple images in the depth direction while saving space and reducing weight.

Further, in one aspect of the present invention, a first electromagnetic shutter disposed between the first image projection section and the first beam splitter; and a first electromagnetic shutter disposed between the second image projection section and the first beam splitter. A second electromagnetic shutter is provided .

Further, in one aspect of the present invention, the imaging position of the first image and the imaging position of the second image are different.

According to the present invention, it is possible to provide an image display device that can form a plurality of images in the depth direction and can save space and be lightweight.

FIG. 1 is a schematic diagram showing the configuration of an image display device 100 according to a first embodiment. FIG. 2 is a schematic diagram showing the configuration of an image display device 110 according to a second embodiment. FIG. 2 is a schematic diagram showing the configuration of an image display device 120 according to a third embodiment.

(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 diagram showing the configuration of an image display device 100 according to this embodiment. As shown in FIG. 1, the image display device 100 includes beam splitters BS1, BS2, BS3, retroreflectors RR1, RR2, an image projection device S, electromagnetic shutters ES1, ES2, ES3, a dichroic mirror DM, and a head. Equipped with a mounted display HMD. Further, the image projection device S functions as a first image projection section S1, a second image projection section S2, and a third image projection section S3, with different display areas displaying images, respectively.

In the image display device 100 shown in FIG. 1, the viewer can view the first image A1, the first image A1, and the Two images A2, a third image A3, and a fourth image H are viewed at different distances in the depth direction. In FIG. 1, the direction in which the first image A1, second image A2, third image A3, and fourth image H are lined up is the depth direction, the up and down direction orthogonal to the depth direction is the vertical direction, and the direction perpendicular to the depth direction is the depth direction. The orthogonal direction is defined as the horizontal direction. In FIG. 1, lines such as a dashed-dotted line, a dashed line, a dashed-double-dotted line, etc. drawn from the first image projection section S1, the second image projection section S2, the third image projection section S3, and the head mounted display HMD, respectively. indicates the path of the projection light of the image irradiated by each.

The 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 beam splitter BS1 is arranged at an angle of 45 degrees with respect to the vertical 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 image projection section S2, and the third image projection section S3.

The 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 beam splitter BS2 is arranged at an angle of 45 degrees with respect to the vertical 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 image projection section S2, and the third image projection section S3. Furthermore, the inclination directions of the beam splitter BS2 and the beam splitter BS1 are opposite to each other, and they are arranged to face each other so as to intersect at an angle of 90 degrees.

The beam splitter BS3 is a member that transmits a portion of the incident light and reflects a portion of the incident light, and can use a partial reflection plate on the surface of which a film for adjusting reflectance is formed. The beam splitter BS3 is arranged at an angle of 45 degrees with respect to the vertical direction and the depth direction. Further, it is also arranged at an angle of 45 degrees with respect to the optical axis of the light emitted from the first image projection section S1 and the second image projection section S2.

The retroreflectors RR1 and RR2 are optical members that reflect the incident light while maintaining condensation in the direction of incidence, and use a structure in which minute glass beads are spread on the surface side of the reflective film or a prism. Retroreflective portions of the structure can be used. The retroreflector RR1 is arranged below the beam splitter BS2, and its main surface is in the horizontal direction. The retroreflector RR2 is arranged in the depth direction along with the beam splitters BS1, BS2, and BS3, and its main surface is in the vertical direction.

Here, an arbitrary balance can be selected for the light transmittance and reflectance of the beam splitters BS1, BS2, and BS3, 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 angles of the beam splitters BS1, BS2, and BS3 are 45 degrees and orthogonal, the direction of light irradiation from the first image projection section S1, second image projection section S2, and third image projection section S3 is An appropriate angle can be used in relation to the imaging position of the image.

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 above the retroreflector RR1 and the beam splitter BS2, and is arranged at an angle of 45 degrees in the depth direction. In the example shown in FIG. 1, the dichroic mirror DM reflects the wavelength of the light emitted from the first image projection section S1 and the second image projection section S2, and transmits the other visible light. As described later, the first image A1, the second image A2, and the third image A3 are formed in space by the light that has passed through the beam splitter BS2, the retroreflectors RR1 and RR2, and the dichroic mirror DM. The combination of optical elements constitutes the imaging optical section in the present invention.

Although not shown in FIG. 1, an imaging lens may be disposed between the beam splitter BS2 and the dichroic mirror DM as part of the imaging optical system. The imaging lens is an optical member for focusing the light transmitted through the beam splitter BS2 on a predetermined position in space, and a plurality of lens groups may be used.

The head mounted display HMD is an image projection unit that forms the fourth image H in space. The specific configuration of the head mounted display HMD is not limited, and known configurations such as one using a light guide plate and a diffraction grating, one using a light guide plate and an optical element, etc. can be used.

The image projection device S and the head-mounted display HMD are devices that each emit light constituting an image, and each projects an image at a predetermined distance from the viewer's eyes. The first image projection unit S1 is disposed below the beam splitter BS1, and irradiates light in a direction perpendicular to the other surface of the beam splitter BS1 (the surface facing the beam splitter BS2). The second image projection section S2 is arranged laterally alongside the beam splitters BS1, BS2, BS3 and the retroreflection section RR2, and is directed toward one surface of the beam splitter BS3 (the surface opposite to the beam splitter BS1). Emits light horizontally. The third image projection unit S3 is arranged below the beam splitter BS3, and irradiates light in a direction perpendicular to the other surface of the beam splitter BS3 (the surface facing the beam splitter BS1). The head mounted display HMD is placed between the viewer's eyes and the dichroic mirror DM.

The image projection device S is a device that displays an image by being driven by a signal input from an image signal input section (not shown), and has different display areas including a first image projection section S1, a second image projection section S2, and a second image projection section S2. It functions as a third image projection section S3. As shown in FIG. 1, the image projection device S includes a first image projection section S1 and a third image projection section S3 located below beam splitters BS1 and BS3, respectively, and a second image projection section S2 located beside the beam splitter BS3. It has two planes connected by a bend so that they are arranged in the same direction. Although the specific configuration of the image projection device S is not limited, for example, a flexible organic EL element or inorganic EL element can be used. In the image display device 100 of this embodiment, since the image projection device S is configured as one device having a plurality of curved display surfaces, the first image projection device S is configured by a signal input from a common image signal input unit. The section S1, the second image projection section S2, and the third image projection section S3 are each driven.

The electromagnetic shutters ES1, ES2, and ES3 are arranged on the light exit surface side of the first image projection section S1, the second image projection section S2, and the third image projection section S3, respectively, and are optical shutters that control transmission and shielding of light. It is a member. The specific configurations of the electromagnetic shutters ES1, ES2, and ES3 are not limited, and for example, liquid crystal shutters can be used.

The images projected by the first image projection unit S1, second image projection unit S2, third image projection unit S3, and head mounted display HMD may be still images or moving images, and the images projected by each may be the same. may also be different. Further, an optical member such as a lens may be provided on the light exit surface side of the first image projection section S1, the second image projection section S2, the third image projection section S3, and the head mounted display HMD.

As shown in FIG. 1, the light emitted from the first image projection unit S1 is reflected by the beam splitter BS1 and then enters the beam splitter BS2, where part of the light is reflected and part of the light is transmitted. The reflected light is re-reflected by the retroreflector RR1, enters the beam splitter BS2 again, passes through the beam splitter BS2, is reflected by the dichroic mirror DM, and is imaged at a first distance as a first image A1. The transmitted light is reflected again by the retroreflector RR2, enters the beam splitter BS2 again, is reflected by the beam splitter BS2, is reflected by the dichroic mirror DM, and is imaged at a first distance as a first image A1. The light formed as the first image A1 passes through the head mounted display HMD and reaches the viewer's eyes. Therefore, the viewer visually recognizes the first image A1 in the air at the first distance in the depth direction.

Further, the light emitted from the second image projection unit S2 passes through the beam splitters BS3 and BS1, and then enters the beam splitter BS2, where part of the light is reflected and part of the light is transmitted. The reflected light is re-reflected by the retroreflector RR1, enters the beam splitter BS2 again, passes through the beam splitter BS2, is reflected by the dichroic mirror DM, and is imaged at a second distance as a second image A2. The transmitted light is re-reflected by the retroreflector RR2, enters the beam splitter BS2 again, is reflected by the beam splitter BS2, is reflected by the dichroic mirror DM, and is imaged at a second distance as a second image A2. The light formed as the second image A2 passes through the head-mounted display HMD and reaches the viewer's eyes. Therefore, the viewer visually recognizes the second image A2 in the air at the second distance in the depth direction.

Further, the light emitted from the third image projection unit S3 is reflected by the beam splitter BS3, and then enters the beam splitter BS2, where part of the light is reflected and part of the light is transmitted. The reflected light is re-reflected by the retroreflector RR1, enters the beam splitter BS2 again, passes through the beam splitter BS2, is reflected by the dichroic mirror DM, and is imaged at a third distance as a third image A3. The transmitted light is reflected again by the retroreflector RR2, enters the beam splitter BS2 again, is reflected by the beam splitter BS2, is reflected by the dichroic mirror DM, and is imaged at a third distance as a third image A3. The light formed as the third image A3 passes through the head mounted display HMD and reaches the viewer's eyes. Therefore, the viewer visually recognizes the third image A3 in the air at the third distance in the depth direction.

At this time, the light retroreflected by the first retroreflector RR1 and the light retroreflected by the second retroreflector RR2 are images of the same content split by the beam splitter BS2, and are superimposed on each other to create a dichroic image. It is necessary to reach the mirror DM. Therefore, when the optical characteristics of the first retroreflector RR1 and the second retroreflector RR2 are the same, the distances of the beam splitter BS2 from the first retroreflector RR1 and the second retroreflector RR2 are made equal. It is preferable.

Furthermore, the light emitted from the head-mounted display HMD reaches the viewer's eyes through an optical path where the image is formed at a fourth distance determined by the optical system included in the head-mounted display HMD. Therefore, the viewer visually recognizes the fourth image H in the air at the fourth distance in the depth direction.

As described above, the viewer is aware that the light that forms the first image A1, the second image A2, the third image A3, and the fourth image H is incident on the same viewer's visual field and at different positions in the depth direction. The first image A1, the second image A2, the third image A3, and the fourth image H can be visually recognized at the first distance, the second distance, the third distance, and the fourth distance. At the same time, the viewer can view the background that passes through the dichroic mirror DM and the head-mounted display HMD and reaches the viewer's eyes. Therefore, the viewer visually recognizes an aerial image in which the first image A1, second image A2, third image A3, and fourth image H are superimposed on the background.

As described above, in the image display device 100 of this embodiment, different display areas of one image projection device S constitute the first image projection section S1, the second image projection section S2, and the third image projection section S3, respectively. There is. Thereby, the first image projection section S1, the second image projection section S2, and the third image projection section S3 can perform display using signals input from a common image signal input section. Therefore, rather than configuring each of the first image projection section S1, second image projection section S2, and third image projection section S3 as a separate image display device and individually wiring and controlling the drive, multiple image projection sections are arranged in the depth direction. This makes it possible to save space and reduce weight while still forming an image.

(Second embodiment)
Next, a second embodiment of the present invention will be described using FIG. 2. Descriptions of contents that overlap with those of the first embodiment will be omitted. FIG. 2 is a schematic diagram showing the configuration of the image display device 110 according to this embodiment. As shown in FIG. 2, the image display device 110 includes beam splitters BS1, BS2, BS3, retroreflectors RR1, RR2, an image projection device S, electromagnetic shutters ES1, ES2, ES3, a dichroic mirror DM, and a head. Equipped with a mounted display HMD.

In the image display device 110 of this embodiment, in the image projection device S, there is a curvature between the plane where the first image projection section S1 and the third image projection section S3 are provided and the plane where the second image projection section S2 is provided. This embodiment differs from the first embodiment in that it has a large curved surface.

As described above, the different display areas of the image projection device S function as the first image projection section S1, the second image projection section S2, and the third image projection section S3, respectively, and A first image A1, a second image A2, and a third image A3 are formed. Therefore, it is preferable that the regions constituting the first image projection section S1, the second image projection section S2, and the third image projection section S3 are flat surfaces, but the flatness of the regions that do not contribute to image display is less important. low. Therefore, as shown in FIG. 2, by forming a curved surface with a large curvature between the second image projection section S2 and the third image projection section S3, the size of the image display device S can be reduced. Furthermore, compared to the first embodiment shown in FIG. 1, the space occupied by the image display device S can be reduced to further save space.

Here, although FIG. 2 shows an example in which a curved surface is formed over the entire area between the second image projection section S2 and the third image projection section S3, by combining a bent section with a small curvature and a flat surface, the second image projection section A flat surface may be provided obliquely between S2 and the third image projection section S3.

Also in the image display device 110 of this embodiment, the first image projection section S1, the second image projection section S2, and the third image projection section S3 can perform display using signals input from a common image signal input section. , it is possible to save space and reduce weight while forming multiple images in the depth direction.

(Third embodiment)
Next, a third embodiment of the present invention will be described using FIG. 3. Description of contents that overlap with those of the first embodiment will be omitted. FIG. 3 is a schematic diagram showing the configuration of the image display device 120 according to this embodiment. As shown in FIG. 2, the image display device 120 includes beam splitters BS1, BS2, BS3, retroreflective sections RR1, RR2, a first image projection section S1, a second image projection section S2, and a third image projection section. S3, flexible cables FC1, FC2, electromagnetic shutters ES1, ES2, ES3, a dichroic mirror DM, and a head mounted display HMD.

In this embodiment, the first image projection section S1 and the third image projection section S3 are connected by the flexible cable FC1, and the second image projection section S2 and the third image projection section S3 are connected by the flexible cable FC2, and the common The image projection device S is driven by a signal input from an image signal input unit (not shown).

The first image projection section S1, the second image projection section S2, and the third image projection section S3 are devices that each project an image at a predetermined distance from the viewer's eyes. The configurations of the first image projection section S1, the second image projection section S2, and the third image projection section S3 are not limited, and include a liquid crystal display device with a backlight, a self-luminous organic EL display device or an inorganic EL element, and a light source. A projector device or the like using a modulation element can be used.

The flexible cables FC1 and FC2 are flexible signal wiring for electrically connecting the first image projection section S1, the second image projection section S2, and the third image projection section S3, respectively. Signal wiring is also provided inside the first image projection section S1, the second image projection section S2, and the third image projection section S3. Therefore, by connecting the first image projection section S1 and the third image projection section S3 with the flexible cable FC1, and connecting between the second image projection section S2 and the third image projection section S3 with the flexible cable FC2, By simply inputting a signal from one image signal input section, signals are supplied to the first image projection section S1, second image projection section S2, and third image projection section S3 included in the image projection device S to display the image. It can be performed.

Furthermore, since the flexible cables FC1 and FC2 have flexibility, the degree of freedom in installing the second image projection section S2 and the third image projection section S3 is improved so that their light emission directions intersect with each other. can be placed. In addition, the areas of the first image projection section S1, second image projection section S2, and third image projection section S3 are minimized to reduce areas that do not contribute to display, and the number of parts is reduced to save space and reduce weight. can be achieved.

Figure 3 shows an example in which the flexible cable FC2 is bent into an arc with a large curvature, but the length and arrangement shape are not limited, and the wiring can be routed using the gaps provided between other members. You may also do this.

Also in the image display device 120 of this embodiment, the first image projection section S1, the second image projection section S2, and the third image projection section S3 can perform display using signals input from a common image signal input section. , it is possible to save space and reduce weight while forming multiple images in the depth direction.

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, 120...Image display device A1...First image A2...Second image A3...Third image S1...First image projection section S2...Second image projection section S3...Third image projection section RR1, RR2...Recursion Reflector ES1, ES2, ES3...Electromagnetic shutter BS1, BS2, BS3...Beam splitter FC1, FC2...Flexible cable

Claims (3)

a first image projection unit that emits a first image;
a second image projection unit that emits a second image;
A first beam splitter that reflects light from the first image projection unit that is incident on a first surface in a first direction, and transmits light from the second image projection unit that is incident on a second surface in the first direction. and,
comprising an imaging optical section that images the light traveling in the first direction in space;
The first image projection unit and the second image projection unit are connected by a flexible signal wiring,
An image display device, wherein the first image projection section and the second image projection section are driven by a signal input from a common image signal input section. The image display device according to claim 1,
a first electromagnetic shutter disposed between the first image projection unit and the first beam splitter;
An image display device comprising: a second electromagnetic shutter disposed between the second image projection unit and the first beam splitter. The image display device according to claim 1 or 2 ,
An image display device characterized in that the imaging position of the first image and the imaging position of the second image are different.