JP2022035397A - Head-up display device - Google Patents

Abstract

To provide a head-up display device that can display virtual images with different virtual image distances, which are inclined at a desired and constant angle.SOLUTION: A middle screen 5 is arranged on a surface perpendicular to an optical path A0 to a foot Q1 of the perpendicular from eyes O of an observer in a display surface P1 of a virtual image Iv1. The middle screen 5 is moved parallel so that a virtual image Iv2 is displayed, which has the same inclination angle θ as that of the virtual image Iv1 and has a different virtual image distance from that of the virtual image Iv1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a head-up display device.

A head-up display (HUD) device is known that projects an image onto the rear surface of a screen (combiner) made of a half mirror and displays it as a virtual image at a predetermined distance in front of the screen. Head-up display devices installed in automobiles display information such as speed and mileage, which was previously displayed on the instrument panel (instrument panel), also in front of the front window (windshield), and in recent years, A virtual image is displayed over a wide area using the windshield as a screen. Such a head-up display device reduces the movement of the driver's line of sight and supports safer driving. For example, an augmented reality (AR) head-up display device has been developed that displays an arrow indicating a course on a road or a distance to a destination in cooperation with a car navigation system.

In general, a head-up display device displays an image on a screen from an image projector equipped with a light source such as an LED (Light Emitting Diode) or LD (Laser Diode) via an optical element such as a reflector or a lens. Project at the angle of incidence. For example, as shown in FIG. 8, the head-up display device 100 forms an image on a diffuse screen (intermediate screen) 105 by an image display device 102 equipped with an LED light source and a DMD (Digital Micromirror Device) to form an intermediate image. Then, an intermediate image is projected onto the front window (screen) S via the magnifying reflector 108, which is a magnifying optical system, and the virtual image Iv1 is displayed. Generally, the optical paths C ₀ , C ₀ ′, and C ₁ to the center point M ₁ of the virtual image Iv 1 are set as the optical axis. Further, depending on the optical path length and focal length from the intermediate screen 105 to the principal point of the optical system composed of the magnifying reflector 108 and the screen S, the position in the depth direction of the virtual image, that is, the eye (eye) of the observer (driver). The distance from the point O) (virtual image distance: VID) is determined. Therefore, a head-up display device capable of changing the virtual image distance by moving an intermediate screen 105 or a reflecting mirror or the like arranged between the intermediate screen 105 and the screen S has been developed (for example, Patent Document 1). ..

Further, in the AR head-up display device for automobiles, it is preferable that the arrow indicating the course as described above is displayed with a long virtual image distance according to the road surface of the actual scene in the driver's line of sight. It is preferable that the speed and the like are displayed in the foreground, that is, at a short virtual image distance, so that they are apparently displayed in the front window S. Therefore, an intermediate screen is provided on a disk that rotates at high speed along the axis along the optical path direction, and the height of the intermediate screen is set across a step along the diameter of the disk so that the position of the intermediate screen in the axial direction changes on the circumference. A device in which an intermediate screen is formed on a plurality of surfaces having a difference (position in the axial direction) or a spiral surface inclined along the circumference of a disk is disclosed (Patent Document 2). By repeatedly changing the height of the area where one frame (one frame) of the intermediate image is projected on the intermediate screen at high speed within a predetermined range, it is possible to simultaneously display multiple virtual images with different virtual image distances. can.

Further, for example, a virtual image such as an arrow displayed on a road is tilted forward with respect to a vertical surface (a plane perpendicular to the ground, a plane including the Y axis) so that the upper side in the virtual image display area is displayed forward (far). May be required to display. In this case, as shown in FIG. 8, the surface (virtual image display surface) P1 on which the virtual image Iv1 is displayed is the eye point O and the virtual image Iv1 (center), although it depends on the viewing angle (depression angle) φ due to the sitting height of the driver. The angle θ ₁ (0 ° <θ ₁ <90 °) is tilted with respect to the vertical plane of the line of sight (optical axis) C ₁ connecting the points M ₁ ). Such a virtual image Iv1 can be displayed by arranging the intermediate screen 105 at an angle with respect to the vertical plane of the optical axis _C0 in the intermediate screen 105 (for example, Patent Document 3).

Japanese Patent No. 6252883 International Publication No. 2019/070080 Japanese Unexamined Patent Publication No. 2020-64235

When the intermediate screen 105 is tilted with respect to the vertical plane of the optical axis C ₀ as shown in FIG. 8 in order to display the virtual image Iv1 in an inclined manner, the inclination angle θ ₀ of the intermediate screen 105 is a virtual image. It does not always match the inclination angle θ ₁ of the virtual image display surface P1 of Iv1. Then, when the intermediate screen 105 is translated in the optical axis C ₀ direction in order to display the virtual images Iv2 having different virtual image distances, the virtual image Iv2 is tilted at an angle θ ₂ (≠ θ ₁ ) different from the virtual image display surface P1. It may be displayed on the virtual image display surface P2. Further, the virtual images Iv1 and Iv2 may be magnified at different magnifications in the vertical direction and the shape may be distorted. It is difficult to arrange or move the intermediate screen 105 at different angles so that the virtual image display surfaces of the virtual images Iv1 and Iv2 having different virtual image distances have a constant and desired tilt angle with respect to the ground. Yes, the structure becomes complicated. Further, it is difficult to draw an intermediate image according to the virtual image distance so that the shapes of the virtual images Iv1 and Iv2 are displayed without distortion.

The present invention has been made in view of the above problems, and is a head-up that can display a virtual image that is tilted at a desired angle and has no shape distortion, and can be displayed at different virtual image distances with a constant tilt angle. An object is to provide a display device.

The above problem of the present invention is solved by the following configuration.

(1) The optical system includes an optical system composed of one or more optical elements including an intermediate screen, and an image projection means for projecting light for forming an intermediate image on the intermediate screen. A head-up display device that projects an intermediate image onto one surface of a screen and displays a virtual image on the other surface of the screen.
Light rays that are vertically emitted from the intermediate screen or a surface including the intermediate screen and reflected on the one surface of the screen and are incident on the observer's eyes are lowered from the observer's eyes to the display surface of the virtual image. It is on the vertical line
A head-up display device characterized in that the display surface of the virtual image is inclined with respect to a surface perpendicular to the ground.

(2) The optical system includes an optical system composed of one or more optical elements including an intermediate screen, and an image projection means for projecting light for forming an intermediate image on the intermediate screen. A head-up display device that projects an intermediate image onto one surface of a screen and displays a virtual image on the other surface of the screen.
The virtual image distance of the virtual image changes due to the parallel movement of at least one of the optical elements, and the light beam emitted vertically from the intermediate screen or the surface including the intermediate screen and reflected by the screen is the eyes of the observer. The light rays incident on the image are always on the vertical line drawn from the observer's eyes to the display surface of the virtual image.
A head-up display device characterized by displaying virtual images of different virtual image distances on a surface inclined at the same angle with respect to a surface perpendicular to the ground.

(3) A ray emitted from an intermediate image when displaying a virtual image at an arbitrary virtual image distance, reflected on the one side of the screen and incident on the observer's eyes, or an extension of the ray, is different from the virtual image distance. The head-up display device according to (2), wherein at least a part of the intersections on the intermediate screen when displaying a virtual image at a virtual image distance is included in the intermediate image formed on the intermediate screen.

According to the head-up display device according to the present invention, a virtual image that is tilted at a desired angle and has no shape distortion can be displayed, and further, the tilt angle can be kept constant and displayed at different virtual image distances.

It is a schematic block diagram explaining the position of the head-up display device which concerns on this invention, and the virtual image displayed by this. It is a schematic diagram of an inverted real image by an imaging optical system of an object inclined with respect to an optical axis. It is a schematic diagram of the inverted real image by the imaging optical system for demonstrating the concept of the head-up display apparatus which concerns on this invention. It is a schematic diagram of the inverted real image by the imaging optical system for demonstrating the concept of the head-up display apparatus which concerns on this invention. It is a schematic diagram of the virtual image optical system for demonstrating the concept of the head-up display apparatus which concerns on this invention. It is a schematic diagram explaining the structure of the head-up display device which concerns on embodiment of this invention. It is a schematic block diagram of the head-up display apparatus which concerns on the modification of embodiment of this invention. It is a schematic block diagram of the head-up display apparatus which concerns on another embodiment of this invention. It is a schematic diagram explaining the position of the conventional head-up display device and the virtual image displayed by this.

Hereinafter, the head-up display device according to the embodiment (embodiment) for carrying out the present invention will be described with reference to the drawings. The members shown in the drawings may be exaggerated in size, positional relationship, etc., and may have a simplified shape or structure in order to clarify the explanation. Further, in the following description, the same or the same quality members are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[Head-up display device]
FIG. 1 is a schematic view of a head-up display device according to the present invention, and is a configuration diagram seen from the side of a state mounted on an automobile. The head-up display device 10 according to the embodiment of the present invention is an AR head-up display device for automobiles having a front window of the automobile as a screen S, and is for a driver (observer; only eyes are shown in the figure). The virtual images Iv1 and Iv2 are displayed in front of the front window S. Therefore, the head-up display device 10 is housed in the instrument panel of the automobile, and projects an image from the window formed on the top plate T of the instrument panel onto the inner surface of the front window S. The front window S functions as a half mirror that transmits and reflects light, and the reflecting surface (the surface inside the vehicle) is generally concave.

The head-up display device 10 includes an optical system including a projection optical system 3, an intermediate screen 5, and a magnifying reflector 8, and an image display device (image projection means) 2, and further displays an image displayed by the image display device 2. It includes an image forming module 1 formed based on an external signal, and a casing (not shown) that accommodates and forms an integrated unit. The light projected from the image display device 2 forms an intermediate image on the intermediate screen 5 via the projection optical system 3, is reflected by the magnifying reflector 8, and is projected onto the inner surface of the vehicle of the front window S. .. Hereinafter, each element of the head-up display device 10 will be described in detail.

(Image formation module)
The image forming module 1 includes a printed circuit board and an integrated circuit (IC) mounted on the printed circuit board, and generates image data based on a signal input from the outside and outputs the image data to the image display device 2. The image forming module 1 may be provided integrally with the image display device 2, or may be connected to the image display device 2 by a flexible flat cable (FFC) or the like.

(Image display device)
The image display device 2 is composed of a light source, a spatial light modulator, and the like, and projects light for forming a two-dimensional intermediate image on the intermediate screen 5. The image display device 2 is preferably a DLP (registered trademark) method, and is composed of an LED light source or a laser light source, and a DMD (Digital Micromirror Device) in which micromirrors driven by MEMS (Micro Electro Mechanical Systems) are two-dimensionally arranged. To. Further, the image display device 2 can also apply a laser scanning method, and is composed of a laser light source and a MEMS-driven mirror. Alternatively, the image display device 2 can be applied with a reflective liquid crystal panel by LCOS (Liquid Crystal On Silicon), and has an LED light source, a total of three liquid crystal panels displaying image patterns of R, G, and B colors, and a total of three liquid crystal panels. It is composed of a color synthesis optical system such as a dichroic prism.

(Intermediate screen)
The intermediate screen 5 is an optical element for forming an image of light emitted from the image display device 2 and passing through the projection optical system 3 as an intermediate image, and the intermediate screen 5 further diffuses the intermediate image. Therefore, in the head-up display device 10, the intermediate screen 5 is preferably arranged within the depth of focus of the projection optical system 3. In the present embodiment, the intermediate screen 5 is a transmissive diffuser plate, for example, a microlens array, and diffuses light incident from one surface side to a desired orientation angle and emits light to the other surface side. Such an intermediate screen 5 is made of a transparent material such as glass or resin. Further, as will be described later, in the head-up display device 10, the intermediate screen 5 is arranged on a plane perpendicular to the virtual optical axis A ₀ .

(Projection optical system)
The projection optical system 3 is an optical element provided as necessary so that the light emitted by the image display device 2 is suitably projected onto the intermediate screen 5 so as to form an intermediate image. For example, the intermediate screen. It is a lens that adjusts the luminous flux diameter, light intensity, spread, and the like of the incident light to the projection region (the region where the image can be formed of the intermediate image) of 5. Although the projection optical system 3 is represented by one convex lens in FIG. 1, it may be composed of two or more lenses, or a reflecting mirror (plane mirror, curved mirror) depending on the arrangement of the image display device 2 and the intermediate screen 5. (See the modified example below). The projection optical system 3 may further include a variable focus optical system or a telecentric optical system.

(Magnifying reflector)
The magnifying reflector 8 projects the light (intermediate image) diffused from the intermediate screen 5 onto the inner surface of the vehicle of the front window S at a predetermined angle of incidence. The magnifying reflector 8 has the shape of the incident surface (generally the inner surface of the vehicle) of the front window S so that the virtual images Iv1 and Iv2 can be displayed in the driver's field of view and at their respective predetermined virtual image distances. It is formed into a surface shape based on it (for example, a concave free curved surface), and its orientation and arrangement are further set. If necessary, the head-up display device 10 may further include an optical element such as a reflector or a lens between the intermediate screen 5 and the magnifying reflector 8.

[Operation of head-up display device]
The concept of the head-up display device according to the present invention will be described.
As shown in FIG. 1, the head-up display device 10 displays the virtual image Iv1 on the virtual image display surface P1 and the virtual image Iv2 on the virtual image display surface P2. Here, the virtual image display surfaces P1 and P2 represent a displayable area of a virtual image by the head-up display device ₁₀ , and the centers of the virtual image display surfaces P1 and P2 are referred to as midpoints M1 and _M2 . Further, the center line C (C ₀ , C ₀ ) is the optical path from the point (points m ₁ , m ₂ in FIG. 5) at which the points displayed at the midpoints M ₁ and M ₂ are projected on the intermediate screen 5 to the eye point O. It is called ´, C ₁ ) and is represented by a one-dot chain line. Specifically, the center line C ₀ is used for the light emitted from the intermediate screen 5 and traveling straight, and the center line C ₀ ′ is used for the light reflected by the magnifying reflector 8 and projected onto the screen S. Then, in the light reflected by the screen S and incident on the eye point O, the center line C ₁ is set. The center line C ₁ is also the line of sight from the eye point O to the midpoints M ₁ and M ₂ .

As shown in FIG. 8, the conventional head-up display device 100 is configured to display virtual images Iv1 and Iv2 with the center line C as the optical axis. Therefore, the image display device 102 projects light with the center line C ₀ as the optical axis onto the intermediate screen 105, and the projection optical system 103 is arranged with the main axis aligned with the center line C ₀ . Further, in order to display the virtual image Iv1 on the virtual image display surface P1 inclined with respect to the plane perpendicular to the center line C1 from the eye point O to the virtual image _Iv1 , the intermediate screen 105 is incident on the intermediate screen 105. It is tilted with respect to the plane perpendicular to the optical axis (center line) C ₀ of light. Since the virtual image display surface P1 has an inclination angle θ ₁ , the intermediate screen 105 has an inclination angle θ ₀ . Further, in order to display the virtual image Iv2 at a virtual image distance longer than that of the virtual image Iv1, the intermediate screen 105 is moved in parallel in the optical axis (center line C ₀ ) direction as shown by the double arrow, and the magnifying reflector 108 is used. The optical path length to the principal point of the optical system composed of the screen S is lengthened.

Here, in order to briefly explain the positions and tilt angles of the object and the virtual image, instead of the virtual image, an image of an inverted real image by a general imaging optical system composed of one convex lens D1 will be described as an example. .. In FIG. 2 and FIGS. 3A and 3B described later, the real image is represented by an arrow pointing downward from the center of the display area.

As shown in FIG. 2, the object OBJ is tilted by an angle θ ₀ (θ ₀ ≠ θ) in order to form a real image Ir1 tilted by an angle θ ₁ with respect to a plane perpendicular to the optical axis A (the main axis of the lens D1). ₁ ). When this object OBJ is moved in the optical axis A direction so as to be closer to the lens D1, an enlarged real image Ir2 having a longer image formation distance than the real image Ir1 is formed. This real image Ir2 is tilted at an angle θ ₂ different from that of the virtual image Iv1. Further, since the lower side (upper side in the object OBJ) of the real images Ir1 and Ir2 is displayed far from the central portion on the optical axis A, the upper side magnification of the object OBJ is high and the lower side magnification is low. The image is distorted.

Therefore, as shown in FIG. 3A, the straight line C connecting the centers (the roots of the arrows in the figure) of the object OBJ and the real image Ir1 perpendicular to the optical axis A is the center (main point) o of the lens D1. It is arranged so as to pass through and be inclined by an angle θ with respect to the optical axis A. In such an arrangement, when the object OBJ is moved along the line C so as to be closer to the lens D1, the imaging distance is longer and larger than that of the real image Ir1, while the real image is perpendicular to the optical axis A like the real image Ir1. Ir2 forms an image with the center on the line C. Since the real images Ir1 and Ir2 are perpendicular to the optical axis A, they have a constant magnification in each image according to the imaging distance, and the image is not distorted. When the object OBJ and the lens D1 arranged in this way are rotated by an angle θ and the line (center line) C is made horizontal as shown in FIG. 3B, the object OBJ and the lens D1 are tilted at the same angle θ as the object OBJ, and the imaging distance is increased. Different real images Ir1 and Ir2 are obtained with the center of the display area aligned.

Similarly, in the virtual image optical system, it is possible to form a virtual image that is tilted to a desired angle and has a uniform magnification within the display area, and further, such a virtual image can be tilted at a constant tilt angle to obtain a virtual image distance. Can be changed. FIG. 4 shows an imaging optical system composed of a concave mirror as an optical model of the head-up display device according to the present invention. As shown in FIG. 4, the object OBJ perpendicular to the optical axis A of the concave mirror D2 is inside the focal point F of the concave mirror D2, and is the center of the object OBJ (the base of the arrow in the figure) and the sphere of the concave mirror D2. The straight line C connecting the center O is arranged so as to be inclined by an angle θ with respect to the optical axis A. Then, on the other side of the concave mirror D2, a virtual image Iv1 perpendicular to the optical axis A is formed with the center as an extension of the line C. When the object OBJ is moved along the line C in the direction away from the concave mirror D2 so as to be closer to the focal point F of the concave mirror D2, the virtual image distance is longer and larger than the virtual image Iv1, while it is perpendicular to the optical axis A like the virtual image Iv1. A virtual image Iv2 whose center is on the line C is formed. Therefore, the line inclined by a desired angle θ with respect to the straight line C connecting the center of the display region of the virtual image Iv1 and the center of the imaging optical system, that is, the observer's eyes is defined as the optical axis A of the imaging optical system, and the object OBJ is defined as the object OBJ. By arranging it on a plane perpendicular to the optical axis A, a virtual image Iv1 that is inclined at the same angle θ with respect to the line C and is uniformly enlarged over the entire region is formed. Further, by moving the object OBJ in parallel so that the distance from the imaging optical system (concave mirror D2) changes, the virtual image distance and the magnifying power are changed, and the virtual image is uniformly magnified over the entire region and the angle is the same as that of the virtual image Iv1. A virtual image Iv2 tilted at θ is formed. Further, at this time, by moving the object OBJ in the line C direction, the center of the display area of the virtual image Iv2 is displayed without shifting from the line C.

Therefore, the head-up display device according to the embodiment of the present invention is configured as described below with reference to FIGS. 1 and 5. FIG. 5 is a schematic view of the head-up display device according to the embodiment of the present invention, and corresponds to a partially enlarged view of FIG. Further, in FIG. 5 and FIGS. 6 and 7 described later, the top plate T of the instrument panel is omitted.

In the head-up display device 10, the optical path perpendicular to the virtual image display surface P1 of the virtual image Iv1 is set as a virtual optical axis (virtual optical axis), and the intermediate screen 5 is perpendicular to the virtual optical axis instead of the object OBJ in FIG. Place on the surface. In general, the AR head-up display device preferably has a viewing angle (FOV) of about 4 ° or more in the vertical direction (V direction). When the tilt angle θ exceeds 1/2 of the viewing angle, the perpendicular line from the eye point O to the virtual image display surface P1 does not pass through the virtual image display surface P1 (virtual image display area). In this case, it is shown in FIG. As described above, the design is based on the optical path (virtual optical axis) A ₁ passing through the intersection (perpendicular foot) Q ₁ on the extension of the virtual image display surface P1. Then, the intermediate screen 5 is arranged on a plane perpendicular to the virtual optical axis A ₀ from the image display device 2 that reaches the point Q ₁ via the magnifying reflector 8 and the screen S. Further, the image display device 2 projects the light of the optical axis a1 parallel to the virtual optical axis A0 onto the intermediate screen ₅ . With such a configuration, the head-up display device 10 magnifies the virtual image Iv1 of the intermediate image formed on the intermediate screen 5 at a uniform magnification over the entire display area, and displays the virtual image _Iv1 of the center line C1 which is the line of sight from the eye point O. Display at an angle with respect to a vertical surface. The window of the top plate T of the instrument panel, the magnifying reflector 8 and the intermediate screen 5 may be arranged in the optical path of the actual luminous flux, and the virtual optical axis A (A ₀ , A ₀ ', A ₁ ). ) Does not have to be placed.

Further, the virtual image distance can be changed by moving the intermediate screen 5 in parallel so that the optical path length to the main point of the optical system composed of the magnifying reflector 8 and the screen S changes. Specifically, when the intermediate screen 5 moves to the incident side (image display device 2 side), the virtual image distance becomes longer. The position of the intermediate screen 5 may change in the direction of the virtual optical axis A ₀ , and the moving direction is not limited as long as it is in the in-plane direction of the intermediate screen 5. However, since the intermediate screen 5 needs to include a projection region (luminous flux) from the image display device 2, it is preferable to move the intermediate screen 5 in the virtual optical axis A ₀ direction or a direction close thereto. In FIGS. 1 and 5, the intermediate screen 5 is configured to move in the center line C ₀ direction. Such movement of the intermediate screen 5 can correspond to, for example, the traveling speed of the automobile.

In order to translate the intermediate screen 5, the head-up display device 10 is provided with a linear motion mechanism (not shown) such as a rack and pinion, to which the intermediate screen 5 is attached. Alternatively, the magnifying reflector 8 or, if an optical element is provided between the intermediate screen 5 and the magnifying reflector 8, may be moved. Further, in order not to shift the center position (points m ₁ , m ₂ ) of the intermediate image formed on the intermediate screen 5 from the center line C ₀ , the image display device 2 is linked to the translation of the intermediate screen 5. And it is preferable to move the projection optical system 3. For example, as shown in FIG. 5, by moving the image display device 2 and the projection optical system 3 in the same center line C ₀ direction and the same distance as the intermediate screen ₅ , the optical axis a2 parallel to the virtual optical axis A0 However, the optical axis a2 can reach the point m ₂ on the center line C ₀ on the intermediate screen 5. In such a configuration, the head-up display device 10 can configure the intermediate screen 5, the image display device 2, and the projection optical system 3 in an integrated unit and attach them to the linear motion mechanism.

Alternatively, the image display device 2 and the projection optical system 3 may be moved in a direction other than the center line C ₀ direction, for example, in a direction perpendicular to the optical axis. When the intermediate screen 5 moves and the distance from the projection optical system 3 changes in this way, the projection optical system 3 is configured so that the depth of focus is equal to or greater than the moving range of the intermediate screen 5. Alternatively, a part or all of the projection optical system 3 may be moved to change the depth of focus of the intermediate image in conjunction with the movement of the intermediate screen 5. With such a configuration, the head-up display device 10 displays the virtual image Iv2 in which the intermediate image is magnified at a uniform magnification over the entire display area at a virtual image distance different from that of the virtual image _Iv1 and is perpendicular to the center line C1. Display at an angle with respect to the surface. Further, the virtual image display surface P1 of the virtual image Iv1 and the virtual image display surface P2 of the virtual image Iv2 have the same angle (φ + θ) with respect to the vertical plane, in other words, the same angle with respect to the head-up display device 10, that is, the virtual image display surface has the same angle. It moves in parallel and the virtual image distance changes.

[Modification example of head-up display device]
As shown in FIG. 6, the head-up display device 10A according to a modification of the embodiment of the present invention further includes a reflector 4 between the projection optical system 3 and the intermediate screen 5, and is provided with an image display device 2 and projection. The optical system 3 may be fixed, and the reflecting mirror 4 may be moved in parallel with the intermediate screen 5. In FIG. 6, the optical axis a0 of the image display device 2 is parallel to the center line C ₀ , and the reflector 4 is moved in the direction of the center line C ₀ together with the intermediate screen 5. Two or more reflectors 4 may be provided, and only a part or all of them are translated. According to this modification, the parts to be moved can be small. The reflector 4 may be arranged between the image display device 2 and the projection optical system 3. In this case, the projection optical system 3 is moved together with the reflector 4. Further, in the image display device 2, the light source may be fixed, and the image display panel such as a DMD may be configured to be translated like a reflector 4.

Only the intermediate screen 5 may be translated, and the area projected by the image display device 2 may be shifted in response to the translation. That is, the image display device 2 moves the luminous flux of the projected light in the direction perpendicular to the optical axis. Therefore, in the image display device 2, many pixels are arranged so as to widen the display area by a shift. Then, the image forming module 1 controls the area displayed by the image display device 2 corresponding to the position of the intermediate screen 5.

Further, the image formation position of the intermediate image on the intermediate screen 5 may be shifted according to the virtual image distance. For example, by moving only the intermediate screen 5 to the incident side, the intermediate image formed on the intermediate screen 5 moves parallel to the virtual optical axis A ₀ , and the center position (point m ₂ ) is from the center line C ₀ . Also shifts down. As a result, the virtual image Iv2 shifts upward on the virtual image display surface P2. In other words, the midpoint M ₂ of the virtual image display surface P2 deviates upward from the center line C ₁ , and the viewing angle φ (see FIG. 1) becomes smaller. Further, the image display device 2, the projection optical system 3, or the reflector 4 is translated in parallel according to the angle formed by the center line C ₀ and the virtual optical axis A ₀ (optical axis a1), and the intermediate image on the intermediate screen 5 is moved. It is also possible to shift the image formation position of. In the head-up display devices 10 and 10A according to the embodiment of the present invention, since the virtual image display surface moves in parallel as described above, the angles (φ + θ) of the virtual images Iv1 and Iv2 with respect to the vertical plane regardless of the viewing angle φ. ) Is constant. When looking at a distance, the driver's line of sight tends to be closer to the horizontal (Z-axis) than diagonally below, and the viewing angle φ tends to be smaller. There are cases. On the contrary, the display area of the virtual image can be shifted downward, and when the center position is shifted to the top of the virtual optical axis A ₁ , the center line C (C ₀ , C ₀ ', C ₁ ) is the virtual optical axis A. It corresponds to (A ₀ , A ₀ ', A ₁ ), and θ = 0 °.

In this way, even when the vertical position of the virtual image (viewing angle φ) is changed along with the virtual image distance, there is an overlap region within the viewing angle before and after the change, that is, the display of the virtual image at an arbitrary virtual image distance. It is preferable to shift the virtual image to the extent that the possible region and the displayable region of the virtual image after the change of the virtual image distance overlap at least partially. Therefore, in the intermediate screen 5 moved to display a virtual image from a certain arbitrary virtual image distance to a different virtual image distance, the intermediate image (projected area) to be imaged is transferred from the projected area of the intermediate screen 5 before the movement to the screen S. It should include at least a part of the intersection of the light beam reflected and incident on the eye point O or its extension line. With such a configuration, even if the virtual image moves vertically (in the V direction) as the virtual image distance changes, there is a part where the display areas of the virtual image overlap from the driver's point of view. It does not cause an unnatural change within the range, and is particularly suitable as an AR head-up display device. The wider the overlapping portion, the more natural the change, and the displayable area of the virtual image with the longer virtual image distance (for example, the virtual image display surface P2) is the entire displayable area of the shorter virtual image (for example, the virtual image display surface P1). It is more preferable to include. As shown in FIG. 4, the virtual image is displayed at an increased magnification so that the viewing angle increases as the virtual image distance increases. Therefore, even if the display area of the virtual image is shifted inward in the display plane by moving the intermediate image in the optical path length direction and inward in the image plane (intermediate screen 5), the movement range is within a certain range. If so, the display area is included in the display area when the virtual image distance is longer.

The head-up display device according to the present invention can also simultaneously display two or more virtual images that are tilted at a uniform angle and have different virtual image distances. As shown in FIG. 7, the head-up display device 10B according to another embodiment of the present invention has a configuration in which an intermediate screen is formed on a transparent disk 50 rotated at high speed by a motor 6 (see Patent Document 2). , The disk 50 has its axis of rotation arranged parallel to the virtual optical axis A ₀ . The disk 50 has a height (rotational axis) having a step along the diameter so that the circular or annular surface on which the intermediate screen is formed is divided into two or more in the circumferential direction and the positions in the rotation axis direction are different from each other. (Position in direction) It has a plurality of different surfaces and spiral surfaces inclined along the circumference. Then, intermediate images forming virtual images having different virtual image distances are alternately projected from the image display device 2 for each partitioned area of the disk 50. With such a configuration, the region on which the intermediate image of the disk 50 is projected becomes a plane perpendicular to the optical axis A ₀ , and moves in the direction of the optical axis A ₀ as the disk 50 rotates. It should be noted that, for example, the image forming module 1 causes the image display device 2 to correspond to each virtual image distance so that the center of each intermediate image forming the virtual image according to the virtual image distance is projected on the center line C ₀ on the disk 50. It is preferably configured to project an image. Further, the entire disk 50 may be configured to be translated like the intermediate screen 5 of the head-up display devices 10 and 10A according to the embodiment.

The head-up display device according to the present invention can easily cope with a change in the height of the eye point O due to the sitting height of the driver or the like. Further, the head-up display device according to the present invention is not limited to a forward-tilted virtual image, and may display a virtual image on a vertical surface regardless of the viewing angle φ, depending on the orientation of the intermediate screen, or in the vehicle width direction (X direction). It is also possible to display a virtual image tilted to.

The present invention is not limited to the above embodiment, and can be applied to, for example, a ship, an aircraft, a medical device, or the like, and can be modified without departing from the spirit of the present invention.

10,10A, 10B Head-up display device 1 Image formation module 2 Image display device (image projection means)
3 Projection optics 4 Reflector 50 Disc 5 Intermediate screen 8 Magnifying reflector S Front window (screen)
Iv1, Iv2 Virtual image

Claims (3)

The optical system comprises an optical system composed of one or more optical elements including an intermediate screen, and an image projection means for projecting light for forming an intermediate image on the intermediate screen, and the optical system displays the intermediate image. A head-up display device that projects on one side of a screen and displays a virtual image on the other side of the screen.
Light rays that are vertically emitted from the intermediate screen or a surface including the intermediate screen and reflected on the one surface of the screen and are incident on the observer's eyes are lowered from the observer's eyes to the display surface of the virtual image. It is on the vertical line
A head-up display device characterized in that the display surface of the virtual image is inclined with respect to a surface perpendicular to the ground. The optical system comprises an optical system composed of one or more optical elements including an intermediate screen, and an image projection means for projecting light for forming an intermediate image on the intermediate screen, and the optical system displays the intermediate image. A head-up display device that projects on one side of a screen and displays a virtual image on the other side of the screen.
The virtual image distance of the virtual image changes due to the parallel movement of at least one of the optical elements, and the light beam emitted vertically from the intermediate screen or the surface including the intermediate screen and reflected by the screen is the eyes of the observer. The light rays incident on the image are always on the vertical line drawn from the observer's eyes to the display surface of the virtual image.
A head-up display device characterized by displaying virtual images of different virtual image distances on a surface inclined at the same angle with respect to a surface perpendicular to the ground. A virtual image distance different from the virtual image distance of a light ray emitted from an intermediate image when displaying a virtual image at an arbitrary virtual image distance, reflected on the one side of the screen and incident on the observer's eyes, or an extension of the light beam. The head-up display device according to claim 2, wherein at least a part of the intersections on the intermediate screen when displaying a virtual image is included in the intermediate image formed on the intermediate screen.

Images