JP2020148950A - Head-up display device - Google Patents

Abstract

To provide a head-up display device that is small in size and can project a virtual image at a plurality of distances.SOLUTION: A head-up display device 100 includes a drawing device 11 for displaying an image to be projected, an intermediate screen 16m having a diffusive function and disposed on a light emission side of the drawing device 11, and an enlarging optical system 17 for enlarging and projecting an intermediate image TI formed on the intermediate screen 16m, and further includes a turn-back mirror 112 between the drawing device 11 and the intermediate screen 16m, for reflecting the light projected from the drawing device 11 to direct to the intermediate screen 16m. The intermediate screen 16m has such deflection characteristics that an incident angle of the light projected from the drawing device 11 to the intermediate screen 16m is different from an emission angle of light outgoing from the intermediate screen 16m.SELECTED DRAWING: Figure 2

Description

The present invention relates to a head-up display device that displays a virtual image ahead of the line of sight.

Since there are restrictions on the installation location of a head-up display (HUD) device mounted on a vehicle or the like, it is required to reduce the size of the device. As an example of a head-up display device, in order to improve the visibility of a virtual image, by combining a diffusion screen and a concave lens as an intermediate image forming portion, the direction and light distribution of the main ray of the image display light transmitted through the intermediate image forming portion. Some have controlled angles (see Patent Document 1). In the head-up display device of Patent Document 1, even if the distance between the intermediate forming portion and the projection mirror is shortened by controlling the direction of the main light ray passing through the intermediate forming portion by a concave lens provided in the intermediate forming portion. A large virtual image is visible. However, since the device of Patent Document 1 is intended for angle control to the extent that the movement of the viewpoint position of the user is taken into consideration, the arrangement of the optical system is limited and the device is insufficiently miniaturized.

Japanese Unexamined Patent Publication No. 2015-59969

The present invention has been made in view of the above background technology, and an object of the present invention is to provide a head-up display device which is small in size and capable of projecting a virtual image at a plurality of distances.

In order to solve the above problems, the head-up display device according to the present invention is formed on an intermediate screen, a drawing device for displaying a projected image, an intermediate screen having a diffusion function and arranged on the light emitting side of the drawing device. It is equipped with a magnifying optical system that magnifies and projects the intermediate image, and has a folding mirror between the drawing device and the intermediate screen that reflects the light projected from the drawing device toward the intermediate screen, and the intermediate screen draws. The angle of incidence of the light projected from the device on the intermediate screen and the angle of emission of the light emitted from the intermediate screen have different deflection characteristics.

According to the above-mentioned head-up display device, in the intermediate screen, the incident angle and the exit angle of the light projected from the drawing device are different, so that the folded mirror side of the intermediate screen (or the anti-intermediate screen) is intentionally used. (Magnifying optical system side), specifically, a space can be created below. That is, since the intermediate screen has a deflection characteristic, the positions of the folding mirror, the drawing device, and the like can be prevented from protruding toward the driver side (or the eye box side), and the device can be miniaturized.

In a specific aspect of the present invention, in the head-up display device, the angle at which light is deflected on the intermediate screen is 0 ° or more and 30 ° or less. Here, the angle at which the light is deflected means the difference between the angle of incidence on the intermediate screen and the angle of emission of the light emitted from the intermediate screen with respect to the main ray of light projected from the drawing device. By setting the deflection angle within the above range, it is possible to prevent the folded mirror from interfering with other members.

In another aspect of the present invention, in the intermediate screen, the light emitted from the intermediate screen is inclined toward the drawing device side (or the side away from the eyebox) with respect to the light projected from the drawing device. In this case, a space can be created directly below the intermediate screen.

In yet another aspect of the present invention, in the intermediate screen, the light emitted from the intermediate screen is inclined to the opposite side (or eyebox side) of the drawing device with respect to the light projected from the drawing device. In this case, a space can be created on the folded mirror side of the intermediate screen (or the anti-magnifying optical system side of the intermediate screen), specifically below, while further reducing the interference between the drawing device and other members. Further, the intermediate screen can be shifted by the drawing device side.

In yet another aspect of the invention, the drawing device comprises a digital mirror device. In this case, it becomes easy to switch images at high speed while maintaining brightness.

In yet another aspect of the invention, the intermediate screen is provided on a disk that rotates about a rotation axis. In this case, the movement of the intermediate screen in the optical axis direction can be stabilized.

In yet another aspect of the invention, the magnifying optics comprises a first mirror and a second mirror.

(A) is a side sectional view showing a state in which the head-up display device of the first embodiment is mounted on a vehicle body, and (B) is a front view from the inside of a vehicle for explaining the head-up display device. It is a conceptual diagram explaining the specific configuration example of a head-up display device. It is a conceptual diagram explaining the structure of a drawing device and the like. (A) and (B) are a plan view and a side view explaining an intermediate screen among head-up display devices, and (C) is a conceptual diagram explaining the movement of a functional area with rotation of an intermediate screen. .. It is a figure explaining a specific example of a light ray in a head-up display device. (A) is a diagram for explaining a virtual image display optical system or the like in the head-up display device of the first embodiment, and (B) is a diagram for explaining a virtual image display optical system or the like of a comparative example. It is a conceptual block diagram explaining the display system for a mobile body including the head-up display device shown in FIG. It is a perspective view explaining the specific display state by the display system for a moving body. It is a figure explaining the specific example of the light ray in the head-up display device of 2nd Embodiment. It is a figure explaining the virtual image display optical system and the like among the head-up display apparatus of FIG.

[First Embodiment]
Hereinafter, the first embodiment of the head-up display device according to the present invention will be described with reference to the drawings.

With reference to FIGS. 1A and 1B, the head-up display device 100 of the present embodiment is a display device mounted in the vehicle body 2, and includes a drawing unit 10 and a display screen 20. The head-up display (HUD) device 100 displays the image information displayed on the drawing device 11 (see FIG. 3) described later in the drawing unit 10 through the display screen 20 by the driver (observer). ) A virtual image is displayed toward the UN.

The drawing unit 10 of the head-up display device 100 is installed so as to be embedded in the dashboard 4 of the vehicle body 2, and directs the display light HK corresponding to the image including driving-related information and danger signals toward the display screen 20. And emit. The display screen 20 is a half mirror, also called a combiner, and is a semitransparent concave mirror or a plane mirror. The display screen 20 is erected on the dashboard 4 by the support of the lower end, and reflects the display light HK from the drawing unit 10 toward the rear of the vehicle body 2. In the case of the illustration, the display screen 20 is a stand-alone type installed separately from the windshield (windshield) 8, but the display screen 20 may be the windshield itself.

As shown in FIGS. 1A and 2, the display light HK reflected by the display screen 20 which is a half mirror is an eyebox corresponding to the pupil HT of the driver UN sitting in the driver's seat 6 and its peripheral position. Guided by EB. The driver UN can observe the display light HK reflected by the display screen 20, that is, the display image IM as a virtual image in front of the vehicle body 2. On the other hand, the driver UN can observe the outside light transmitted through the display screen 20 which is a half mirror, that is, the front view, the real image of the automobile and the like. As a result, the driver UN superimposes the external world image behind the display screen 20 and displays the display image (virtual image) IM including the driving-related information and the danger signal formed by the reflection of the display light HK on the display screen 20. Can be observed.

As shown in FIG. 2, the drawing unit 10 includes a main body optical system 13, a display control unit 18 for operating the main body optical system 13, and a housing 14 for accommodating the main body optical system 13 and the like. Of these, the combination of the main body optical system 13 and the display screen (combiner) 20 constitutes the virtual image display optical system 30. In FIG. 2 and the like, the coordinate axis XYZ has the origin at the center of the eyebox EB corresponding to the position between the pupil HTs of a general driver UN, but is displayed in a state where the origin is shifted for convenience.

The main body optical system 13 includes an intermediate image forming unit 12 that forms an intermediate image TI, a folded mirror 112, a diffusion unit 16 that is arranged in the latter stage of the optical path close to the imaging position of the intermediate image TI, and a diffusion unit 16. It is provided with a magnifying optical system 17 on which the display light HK from the intermediate image TI formed in is incident. Although the details will be described later, the virtual image projection distance of the display image IM is variable depending on the main body optical system 13. Of the main body optical systems 13, the combination of the magnifying optical system 17 and the display screen 20 arranged above the main body optical system 13 is an injection-side synthetic optical system that converts the intermediate image TI on the diffuser 16 into a virtual image. It constitutes 30b.

As shown in FIG. 3, the intermediate image forming unit 12 is, for example, a projector unit including a drawing device 11 and a projection optical system 15 that forms an image formed on the drawing device 11 as an enlarged intermediate image TI. The drawing device 11 is a display unit having a two-dimensional display surface 11a. The image formed on the display surface 11a of the drawing device 11 is magnified by the projection optical system 15 of the intermediate image forming unit 12 and formed on the diffusing unit 16 as an intermediate image TI, and is guided to the magnifying optical system 17 and the like. At this time, by using the drawing device 11 capable of two-dimensional display, switching between the intermediate image TI or the display image (virtual image) IM can be performed at a relatively high speed. Although details will be described later, for example, a digital mirror device (DMD) can be used as the drawing device 11, and in this case, the intermediate image forming unit 12 is referred to as DLP (Digital Light Processing) (registered trademark). Become. When the DMD is used as the drawing device 11, it becomes easy to switch images at high speed (including high-speed intermittent display) while maintaining brightness, which is advantageous for a display in which the virtual image distance or the projection distance is changed. As an application example, when the virtual image is simultaneously projected over a plurality of distances, the drawing device 11 displays the virtual image at a frame rate of, for example, 30 fps or more, preferably 60 fps or more per distance of the virtual image. Thereby, the flicker of the virtual image can be improved when a plurality of display image (virtual image) IMs are displayed to the driver UN at the same time at different projection distances.

FIG. 3 is a diagram illustrating a specific configuration of the drawing device 11. In this embodiment, as the drawing device 11, a device having a digital mirror device (DMD) is illustrated. The drawing device 11 includes an illumination optical system 5 that emits illumination light, and a display device 7 that generates an image by two-dimensional spatial modulation of the illumination light. The illumination optical system 5 includes three light sources 4a, 4b, 4c that emit illumination light, a first dichroic mirror 5a, a second dichroic mirror 5b, collimators 5d, 5e, 5f, a relay lens 5h, and a fly. It includes an eye optical system 5j, condenser lenses 5m and 5n, a bending mirror 5p, a TIR prism 5q, and a flat plate 5r. The three light sources 4a, 4b, and 4c are LEDs (light emitting diodes) and other light emitting elements, and emit three colors of illumination lights La, Lb, and Lc of R, G, and B, respectively. The light source 4a is an R light source, the light source 4b is a G light source, and the light source 4c is a B light source. The first dichroic mirror 5a synthesizes the illumination light Lb of G from the second light source (G light source) 4b and the illumination light Lc of B from the third light source (B light source) 4c, and the second dichroic mirror 5b synthesizes the illumination light La of R from the first light source (R light source) 4a and the illumination lights Lb and Lc of G and B synthesized by the first dichroic mirror 5a. The collimators 5d, 5e, and 5f bring the illumination lights La, Lb, and Lc from the light sources 4a, 4b, and 4c into a state close to a parallel luminous flux. The relay lens 5h has a role of compensating for the optical path difference on the illumination light Lb and Lc sides. The fly-eye optical system 5j is also called an optical integrator and homogenizes the illumination lights La, Lb, and Lc from the light sources 4a, 4b, and 4c. The condenser lenses 5m and 5n make the illumination lights La, Lb, and Lc passing through the fly-eye optical system 5j incident on the display device 7 in an appropriate angle of incidence range. The TIR prism 5q separates the optical path of the illumination light La, Lb, Lc from the optical path of the display light HK by utilizing the presence or absence of total reflection. Specifically, it is possible to totally reflect the illumination light on the slope 5w of one of the prisms constituting the TIR prism 5q and guide the illumination light to the display device 7 from a direction inclined with respect to the optical axis AX of the projection optical system 15. The light from the display device 7 can be transmitted in the front direction along the optical axis AX of the projection optical system 15 and incident on the projection optical system 15 as the display light HK. The flat plate 5r is a cover glass of the display device 7, but can also have a filter function.

The display device 7 is a digital mirror device (DMD), and can perform on / off operation such that the illumination light incident from the TIR prism 5q is directed to the projection optical system 15 or deflected from the projection optical system 15 through the TIR prism 5q. is there. The operation of the display device 7 is synchronized with the light sources 4a, 4b, and 4c that emit light sequentially, and forms the display light HK of three colors R, G, and B sequentially or simultaneously.

The projection optical system 15 is a fixed focus lens system and has a plurality of lens elements. The projection optical system 15 uses an image formed on the display surface 11a of the drawing device 11 as an intermediate image TI or a forced intermediate image TI'on the diffuser 16 (specifically, an intermediate screen 16 m provided on the surface of the diffuser 16). Enlarge and project at an appropriate magnification (at a position close to). The forced intermediate image TI'includes not only the intermediate image TI itself but also an image that is slightly out of focus due to a displacement from the intermediate image TI, and is sometimes referred to as an intermediate image TI in a broad sense.

As shown in FIG. 2 and the like, the folded mirror 112 is a planar mirror and has no optical power. The folded mirror 112 is provided between the intermediate image forming portion 12 and the diffusing portion 16, and reflects the light emitted from the intermediate image forming portion 12 toward the diffusing portion 16. Specifically, the folded mirror 112 reflects light from the front of the vehicle body 2 upward, for example. By providing the folded mirror 112, the size of the device can be reduced. However, the miniaturization of the device is not sufficient simply by providing the folding mirror 112, and as will be described later, the intermediate screen 16m of the diffuser 16 is provided with a deflection characteristic so that the folding mirror 112 can be mounted on the driver UN (or It can be arranged on the front side of the vehicle body 2 on the side opposite to the eye box EB side). Further, in the present embodiment, the intermediate image forming portion 12 is a DLP, and the folded mirror 112 is indispensable from the viewpoint of space saving.

The diffusion unit 16 is a transmission type diffusion member provided with an intermediate screen 16m on the surface. The intermediate screen 16m has a diffusion property. The intermediate screen 16m forms an intermediate image TI or a forced intermediate image TI'at the imaging position (that is, the planned imaging position of the intermediate image TI or its vicinity) by diffusing the incident display light HK. The intermediate screen 16m can control the diffusion angle to a desired angle. By moving the diffusion unit 16 or the intermediate screen 16m in the optical axis AX direction as described later, the position of the forced intermediate image TI'can also be moved in the optical axis AX direction. The optical axis AX passes through the center of the drawing device 11, the center of the eyebox EB, and the image point (virtual image) corresponding to the center of the drawing device 11 created by the head-up display device 100. Since the forced intermediate image TI'is formed on the intermediate screen 16 m, this becomes a new secondary light source and the light is diffused, so that the eyebox EB can be widely secured even if the magnified optical system 17 magnifies and projects the light. it can. The intermediate screen 16m can be a sheet attached to the rotating body 16a, but may be a fine uneven pattern formed on the surface of the rotating body 16a. As the diffuser 16 or the intermediate screen 16 m, for example, a diffuser, a diffuser, a microlens array, or the like can be used. Further, the intermediate screen 16m may be formed so as to be embedded inside the rotating body 16a. In the diffusion unit 16, a cover may be provided around the rotating body 16a.

The diffusion unit 16 has a spiral rotating body (rotating disk) 16a having a contour similar to that of a disk as a whole. The diffusion unit 16 is arranged at the projection position or the imaging position (that is, the planned imaging position of the intermediate image TI or its vicinity) by the intermediate image forming unit 12 shown in FIG. 1, and is driven by the driving device 162, for example, at a constant speed. It rotates around the rotation axis SX parallel to the optical axis AX.

As shown in FIGS. 4A and 4B, the rotating body 16a has a central portion 16c and an outer peripheral optical portion 16p. In FIGS. 4 (A) to 4 (C), for convenience of explanation, the diffusion unit 16 is shown with reference to local xyz Cartesian coordinates. One surface 16f formed on the outer peripheral optical portion 16p of the rotating body 16a is formed on a smooth surface or an optical surface, and an intermediate screen 16m serving as a diffusion surface is provided on the surface 16f over the entire area. There is. The other surface 16s formed on the outer peripheral optical portion 16p of the rotating body 16a is formed on a smooth surface or an optical surface. The rotating body 16a is a spiral member having light transmission, and the pair of surfaces 16f and 16s are spiral surfaces having the rotating axis SX as the spiral axis. As a result, the intermediate screen 16m formed on one surface 16f is also formed along the spiral surface. The rotating body 16a has substantially the same thickness t with respect to the rotation axis SX or the optical axis AX direction. The intermediate screen 16 m is formed in a range corresponding to one cycle of the spiral. That is, the intermediate screen 16m is formed in the range of one pitch of the spiral. As a result, a step portion 16j is formed at one location along the circumference of the diffusion portion 16. By forming the rotating body 16a in such a shape, it is possible to continuously change the position of the intermediate screen 16m provided on the rotating body 16a in the optical axis AX direction, and it is possible to perform projection that changes the virtual image projection distance. Become.

In the rotating body 16a, one location along the circumferential direction is a functional region FA through which the optical axis AX of the main body optical system 13 passes, and an intermediate image TI (more accurately) is formed by a portion of the intermediate screen 16 m in the functional region FA. A forced intermediate image TI') is formed. This functional area FA moves at a constant speed on the rotating body 16a as the rotating body 16a rotates. That is, by rotating the rotating body 16a and incident the display light (image light) HK on the functional region FA which is a part of the rotating body 16a, the position of the functional region FA or the intermediate image TI reciprocates along the optical axis AX. (If the display of the drawing device 11 is not operating, an intermediate image as a display is not necessarily formed, but the position where the intermediate image is likely to be formed is also called the position of the intermediate image). In the illustrated example, since the intermediate screen 16m is formed in a range corresponding to one cycle of the spiral, the functional region FA or the intermediate image TI of the intermediate screen 16m is stepped in the optical axis AX direction in one rotation of the rotating body 16a. It will make one round trip only for the distance corresponding to.

The projection optical system 15 has a predetermined depth of focus equal to or larger than the moving range of the functional region FA so that the focus does not occur depending on the position of the rotating body 16a of the diffuser 16 or the intermediate screen 16m.

By rotating the diffuser 16 around the rotation axis SX at a constant speed by the drive device 162, as described above, the position where the intermediate screen 16m of the rotating body 16a intersects the optical axis AX (that is, the functional area FA) is also obtained. It moves in the direction of the optical axis AX. That is, for example, as shown in FIG. 4C, as the rotating body 16a rotates, the functional area FA on the intermediate screen 16m becomes, for example, an adjacent functional area FA'set at a position deviated at an equal angle. It shifts sequentially and moves in the optical axis AX direction. By moving the functional area FA in the optical axis AX direction, the position of the intermediate image TI can also be moved in the optical axis AX direction. The diffuser 16 rotates around the rotation axis SX, and the position of the intermediate image TI corresponding to the functional region FA repeatedly and periodically moves in the optical axis AX direction, and is formed behind the display screen 20 by the magnifying optical system 17. The distance between the display image IM as a virtual image and the driver UN who is the observer can be lengthened or shortened. In this way, by changing the position of the projected display image IM back and forth and making the display content according to the position, the display image IM is changed while changing the virtual image distance or the projection distance to the display image IM. Is changed, and the display image IM as a series of projected images can be made three-dimensional.

As shown in FIGS. 5 and 6 (A), in the intermediate screen 16m, the angle of incidence of the light projected from the drawing device 11 on the intermediate screen 16m and the angle of emission of the light emitted from the intermediate screen 16m are different. It has characteristics. Specifically, the incident angle θ1 of the light ray IL corresponding to the light on the optical axis AX of the intermediate image forming unit 12 on the intermediate screen 16 m is enlarged with respect to the short side direction or the lateral direction of the intermediate screen 16 m or the functional region FA. It is different from the emission angle θ2 from the intermediate screen 16m of the light ray OL corresponding to the light on the optical axis AX of the optical system 17. In FIG. 5, reference numeral HK1 indicates a display light corresponding to the lower end of the display image (virtual image) IM, reference numeral HK2 indicates a display light corresponding to the center of the display image (virtual image) IM, and reference numeral HK3 indicates a display light (reference numeral HK3). Virtual image) Indicates the display light corresponding to the upper end of the IM. Further, in the intermediate screen 16 m, the angle at which light is deflected is 0 ° or more and 30 ° or less. Here, the angle at which the light is deflected means the difference between the angle of incidence on the intermediate screen 16m and the emission angle of the light emitted from the intermediate screen 16m with respect to the main ray of light projected from the drawing device 11. .. By setting the deflection angle within the above range, it is possible to prevent the folded mirror 112 from interfering with other members.

In the present embodiment, the light emitted from the intermediate screen 16m is inclined toward the drawing device 11 side (or the side away from the eyebox EB) with respect to the light projected from the drawing device 11. As a result, the space SP can be directly formed on the folded mirror 112 side of the intermediate screen 16 m (or the anti-magnifying optical system 17 side of the intermediate screen 16 m), specifically, downward.

On the other hand, as shown in FIG. 6B as a comparative example, when the intermediate screen 16m does not have a deflection characteristic, the folding mirror 112 is arranged closer to the driver UN side (or the eyebox EB side). Insufficient miniaturization of the device.

As shown in FIG. 2 and the like, the magnifying optical system 17 is a magnifying optical system that magnifies the forced intermediate image TI'formed on the intermediate screen 16 m of the diffuser 16 in cooperation with the display screen 20, and is a driver UN. A display image IM as a virtual image is formed in front of the screen. The magnifying optical system 17 is composed of a first mirror 17a and a second mirror 17b. The first and second mirrors 17a and 17b are free-curved mirrors having a concave shape as a whole and have optical power. Here, the free-form surface shape also includes an aspherical surface.

The housing 14 has an opening 14a through which the display light HK is passed, and a film or a thin plate-shaped light transmitting member 14b can be arranged in the opening 14a.

FIG. 7 is a block diagram illustrating a mobile display system 200, and the mobile display system 200 includes a head-up display device 100 as a part thereof. The head-up display device 100 has the structure shown in FIG. 2, and description thereof will be omitted here. The moving body display system 200 shown in FIG. 7 is incorporated in a moving body such as an automobile.

The mobile display system 200 includes an environment monitoring unit 72 and a main control device 90 in addition to the head-up display device 100.

The environment monitoring unit 72 is a part that identifies an automobile, a bicycle, a pedestrian, etc. that are close to the front, and includes an external camera 72a, an external image processing unit 72b, and an external image determination unit 72c. The external camera 72a is installed at an appropriate position inside and outside the vehicle body 2 and captures external images of the driver UN or the windshield 8 in front of and to the side. The external image processing unit 72b performs various image processing such as brightness correction on the image captured by the external camera 72a to facilitate the processing by the external image determination unit 72c. The external image determination unit 72c determines the existence or nonexistence of an object such as an automobile, a bicycle, or a pedestrian (see, for example, the object OB shown in FIG. 8) by extracting or cutting out an object from an external image that has passed through the external image processing unit 72b. At the same time as detecting, the spatial position of the object in front of the vehicle body 2 is calculated from the depth information attached to the external image.

Although not shown, the external camera 72a is, for example, a compound eye type three-dimensional camera. That is, the external camera 72a is a matrix of camera elements in which a lens for imaging and a CMOS or other imaging element are arranged in a matrix, and each has a drive circuit for the imaging element. The plurality of camera elements constituting the external camera 72a are designed to focus on different positions in the depth direction, for example, or can detect relative parallax, and images obtained from each camera element. By analyzing the state of (focus state, object position, etc.), the distance to each area or object in the image can be determined.

Further, even if a combination of a two-dimensional camera and an infrared distance sensor is used instead of the compound-eye type external camera 72a as described above, each part (area or object) in the captured screen is in the depth direction. Distance information can be obtained. Further, instead of the compound-eye type external camera 72a, a stereo camera in which two two-dimensional cameras are separately arranged can obtain distance information in the depth direction with respect to each part (area or object) in the captured screen. In addition, with a single two-dimensional camera, distance information in the depth direction can be obtained for each part (area or object) in the captured screen by performing imaging while changing the focal length at high speed.

The display control unit 18 operates the virtual image display optical system 30 under the control of the main control device 90 to display a three-dimensional display image IM in which the virtual image distance or the projection distance changes behind the display screen 20. The display control unit 18 generates a display image IM to be displayed on the virtual image display optical system 30 from the display information including the display shape and the display distance received from the environment monitoring unit 72 via the main control device 90. The display image IM is, for example, a display frame (for example, see the display frame HW shown in FIG. 8) located in the vicinity of an automobile, a bicycle, a pedestrian, or another object existing behind the display screen 20 in the depth position direction thereof. It can be a sign like this.

The main control device 90 has a role of harmonizing the operations of the head-up display device 100, the environment monitoring unit 72, and the like, and virtual image display optics so as to correspond to the spatial position of the object detected by the environment monitoring unit 72. The spatial arrangement of the display frame projected by the system 30 is adjusted.

FIG. 8 is a perspective view illustrating a specific display state. The front of the driver UN, which is the observer, is a detection area VF corresponding to the observation field of view. It is considered that the objects OB1 and OB3 of a person such as a pedestrian and the object OB2 of a moving object such as an automobile exist in the detection area VF, that is, in the road and its surroundings. In this case, the main control device 90 projects a three-dimensional display image (virtual image) IM by the head-up display device 100, and displays frames HW1, HW2 as related information images for each object OB1, OB2, OB3. HW3 is added. At this time, since the distances from the driver UN to each object OB1, OB2, OB3 are different, the projected distance from the driver UN to each object is the projected distance to the display images IM1, IM2, IM3 for displaying the display frames HW1, HW2, HW3. It corresponds to the distance to OB1, OB2, and OB3. The projected distances of the displayed images IM1, IM2, and IM3 are discrete and cannot be accurately matched with the actual distances to the objects OB1, OB2, and OB3. However, if the difference between the projected distance of the displayed images IM1, IM2, IM3 and the actual distance to the objects OB1, OB2, OB3 is not large, parallax is unlikely to occur even if the viewpoint of the driver UN moves, and the object OB1, The arrangement relationship between the OB2 and OB3 and the display frames HW1, HW2 and HW3 can be substantially maintained.

According to the head-up display device 100 described above, in the intermediate screen 16m, the incident angle and the exit angle of the light projected from the drawing device 11 are different from each other, so that the folded mirror of the intermediate screen 16m is intentionally folded. A space can be created on the 112 side (or the anti-magnifying optical system 17 side of the intermediate screen 16 m), specifically below. That is, since the intermediate screen 16m has a deflection characteristic, the positions of the folding mirror 112, the drawing device 11, etc. can be prevented from protruding to the driver UN side (or the eyebox EB side), and the device can be miniaturized. ..

[Second Embodiment]
Hereinafter, the head-up display device according to the second embodiment will be described. The head-up display device of the second embodiment is a modification of the head-up display device of the first embodiment, and items not particularly described are the same as those of the first embodiment.

As shown in FIGS. 9 and 10, in the intermediate screen 16m, the light emitted from the intermediate screen 16m is on the opposite side (or eyebox EB side) of the drawing device 11 with respect to the light projected from the drawing device 11. It has a tilting characteristic. As a result, the interference between the drawing device 11 and other members (specifically, the device attached to the intermediate screen 16m) is further reduced, and the folding mirror 112 side of the intermediate screen 16m (or the anti-magnifying optics of the intermediate screen 16m). System 17 side), specifically, a space SP can be created below. Further, the intermediate screen 16m can be shifted by the drawing device 11 side.

Although the head-up display device as a specific embodiment has been described above, the head-up display device according to the present invention is not limited to the above. For example, in the above embodiment, the arrangement of the head-up display device 100 can be inverted so that the display screen 20 can be arranged on the upper part of the windshield 8 or at the sun visor position. In this case, the display screen 20 is arranged diagonally downward and forward of the drawing unit 10. Further, in the head-up display device 100, a wide space in front of the head of the driver UN can be secured. In the above embodiment, the display screen 20 is a flat surface or a concave surface, but it may be a free curved surface having no symmetry.

Further, in the above embodiment, the outline of the display screen 20 is not limited to a rectangle, and may have various shapes.

Further, in the above embodiment, the main body optical system 13 shown in FIG. 2 and the like is merely an example, and the optical configuration of these main body optical systems 13 can be appropriately changed. For example, one or more mirrors having no optical power may be arranged in the optical path of the magnifying optical system 17 or the projection optical system 15.

Further, in the above embodiment, the magnifying optical system 17 is provided with two mirrors, but one or three or more mirrors may be provided. Further, the mirror may be omitted. Further, the optical surface of the mirror is a free curved surface having symmetry, but the present invention is not limited to this, and a free curved surface having no symmetry may be used. Further, the mirror may be a convex surface or a flat surface, and in the case of a curved surface, it may be a spherical surface, an aspherical surface, or the like.

Further, in the above embodiment, the DMD is used as the drawing device 11, but a reflective liquid crystal device (LCOS: Liquid crystal on silicon), a liquid crystal display (LCD: liquid crystal display), and other types of display devices such as organic EL may be used. Further, the drawing device 11 may use a scanning type video device using MEMS instead of the reflective element.

Further, in the above embodiment, the display screen 20 may be provided on the windshield (windshield) 8 shown in FIG. 1 (A) without providing the combiner (see FIG. 2). Specifically, for example, the display screen 20 may be attached to the inside of a rectangular reflection region provided in front of the driver's seat of the windshield (windshield) 8 forming the front window. The display screen 20 can also be embedded in the windshield 8.

Further, in the above embodiment, the projection optical system 15 is a fixed focus optical system, but it may be a focus variable optical system.

Further, in the above embodiment, the configuration of the intermediate screen 16m can be appropriately changed according to the specifications of the head-up display device 100. For example, the intermediate screen 16 m may have a deflection characteristic in the long side direction as well. Further, the intermediate screen 16m may have a structure having diffusion characteristics in the short side direction and the long side direction.

Further, in the above embodiment, the intermediate screen 16m is moved along the optical axis AX by using the rotating body 16a, but the intermediate screen 16m is composed of a plurality of members having different positions in the optical axis direction, and these plurality of members. The arrangement of the intermediate screen 16m can be changed by sequentially replacing the screens with a rotating mechanism or other mechanism.

The head-up display device 100 described above is not limited to a projection device mounted on an automobile or other moving body, and can be incorporated into, for example, digital signage, but can also be applied to applications other than these.

2 ... Body, 7 ... Display device, 8 ... Front glass, 10 ... Drawing unit, 11 ... Drawing device, 12 ... Intermediate image forming part, 13 ... Main body optical system, 15 ... Projection optical system, 16 ... Diffusing part, 16a ... Rotating body, 16m intermediate screen, 17 ... magnifying optical system, 17a ... first mirror, 17b ... second mirror, 18 ... display control unit, 20 ... display screen, 30 ... virtual image display optical system, 72 ... environmental monitoring unit, 90 … Main control device, 100… Head-up display device, 112… Folded mirror, 162… Drive device, 200… Display system for moving objects, AX… Optical axis, EB… Eyebox, FA… Functional area, HK, HK1, HK2 , HK3 ... Display light, HT ... Eye, IMI, M1, IM2, IM3 ... Display image, SX ... Rotation axis, TI ... Intermediate image, UN ... Driver

Claims (7)

A drawing device for displaying an image to be projected, an intermediate screen having a diffusion function and arranged on the light emitting side of the drawing device, and a magnifying optical system for magnifying and projecting an intermediate image formed on the intermediate screen are provided.
A folded mirror is provided between the drawing device and the intermediate screen to reflect the light projected from the drawing device toward the intermediate screen.
The intermediate screen is a head-up display device characterized in that the angle of incidence of light projected from the drawing device on the intermediate screen and the angle of emission of light emitted from the intermediate screen have different deflection characteristics. The head-up display device according to claim 1, wherein the angle at which the light is deflected in the intermediate screen is 0 ° or more and 30 ° or less. The method according to any one of claims 1 and 2, wherein in the intermediate screen, the light emitted from the intermediate screen is inclined toward the drawing device with respect to the light projected from the drawing device. Head-up display device. One of claims 1 and 2, wherein in the intermediate screen, the light emitted from the intermediate screen is inclined to the side opposite to the drawing device with respect to the light projected from the drawing device. The head-up display device described in. The head-up display device according to any one of claims 1 to 4, wherein the drawing device includes a digital mirror device. The head-up display device according to any one of claims 1 to 5, wherein the intermediate screen is provided on a disk that rotates about a rotation axis. The head-up display device according to any one of claims 1 to 6, wherein the magnifying optical system includes a first mirror and a second mirror.

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