JP7095018B2 - Head-up display device - Google Patents

Description

The present invention relates to an information display device that projects an image onto the windshield of an automobile, train, aircraft, etc. (hereinafter, also generally referred to as a "vehicle"), and observes the image as a virtual image through the windshield. The present invention relates to a virtual image optical system and an information display device using the virtual image optical system.

A so-called head-up display (HUD: Head-Up) that projects image light onto the windshield of an automobile to form a virtual image and displays traffic information such as route information and traffic jam information, as well as automobile information such as remaining fuel and cooling water temperature. -Display) device is already known by the following Patent Document 1.

In this type of information display device, for the purpose of facilitating the driver's recognition of information, a virtual image is formed at a plurality of positions according to the driver's visual position, that is, the distance formed by the virtual image is determined by the driver. It is required to match the visual position of. Therefore, for example, as disclosed in Patent Document 2 below, there are some that form images at a distance (long distance) and a vicinity (short distance) from the driver.

Japanese Unexamined Patent Publication No. 2009-229552 JP-A-2015-34919

In the example of the head-up display device disclosed in Patent Document 1, the image light displayed on the liquid crystal display panel is mapped as a real image (Ir in FIG. 2 of Patent Document 1) by the relay optical system, and the eyepiece optical system (in the same figure). It is configured to observe a virtual image (Iv in the figure) via L1). When arranged in terms of mapping, the image light (plane) on the liquid crystal display panel is mapped to the real image Ir (plane), and the real image Ir (plane) is mapped to the virtual image Iv (plane).

However, the driver's foreground is not a two-dimensional plane, but a three-dimensional space. Therefore, with reference to FIG. 22, the line-of-sight direction from the driver in the automobile (own vehicle) and the distance to the line-of-sight direction will be described.

The foreground view range seen by the driver of the own vehicle 101 includes the front vehicle 102 running ahead, the road surface 105 in front of it (for example, whether there are any falling objects on the road surface, etc.), and near the edge of the road. There are bicycles running on the road and pedestrians on the sidewalk.

The line-of-sight direction 103 looking at the preceding vehicle 102 running ahead is a direction in which the line-of-sight is slightly lowered from the direction directly in front, while the line-of-sight direction 104 looking at the road surface 105 in front of the road surface 105 is a direction in which the line-of-sight is further lowered. become. In this way, it can be seen that the distance to the object that the driver should pay attention to while driving differs depending on the line-of-sight direction.

Therefore, in order to further improve the driving safety of a car, the distance to the object being watched while driving and the distance to the virtual image displayed at that time are brought closer to focus the eyes. It is important to reduce the time.

Further, in the head-mounted display device example disclosed in Patent Document 2 above, a virtual image is formed at a different distance from the driver. Specifically, a screen is selected according to the display content. It is essential to focus at high speed with a varifocal lens according to the selected screen. For this reason, as a varifocal lens, a "liquid lens that changes the liquid interface of the liquid enclosed in the container" or "a concave mirror configured so that the curvature can be changed" is used, and the head-mounted display device is used. The size will increase and the cost will increase.

Further, when there are a plurality of viewpoint positions of the driver, the reflective surface of the front glass, which is the projected member (6), is the center position of the vertical curvature radius of the vehicle body and the horizontal curvature radius of the vehicle body of the front glass and the driver. Due to the different eye positions, the displayed image is distorted, but this point was not taken into consideration at all.

As described above, in the above-mentioned conventional information display device, it is difficult to suppress the enlargement and complexity of the device configuration and to form a virtual image at different viewpoint positions (distances) of the driver. Furthermore, neither the displayed image nor the point that distortion occurs depending on the viewpoint position of the driver is taken into consideration at all.

Therefore, the present invention has been achieved in view of the above-mentioned problems in the prior art, and more specifically, different viewpoint positions (distances) from the driver while suppressing the increase in size and complexity of the device. ) Also, it is an object of the present invention to provide an information display device capable of forming a highly visible virtual image.

The present invention made to achieve the above object is, for example, an information display device for displaying virtual image video information on the front glass of a vehicle, a liquid crystal display panel for displaying the video information, and the liquid crystal display. The virtual image optical system comprises a virtual image optical system that displays a virtual image in front of the vehicle by reflecting the light emitted from the panel by the front glass, and the virtual image optical system includes a concave mirror and a plurality of optical elements. The concave mirror has a reflective surface made of a metal film having a high spectral reflectance to visible light and is uniform on the surface of the base material, and the plurality of optical elements are directed from the upper part to the lower part of the front glass. The image light beam that establishes each virtual image is separated between the liquid crystal display panel and the concave mirror so that the plurality of virtual images are established at a plurality of positions corresponding to the viewpoint position of the driver. It is an information display device.

According to the present invention described above, an information display device capable of forming a highly visible virtual image even at different viewpoint positions (distances) from the driver while suppressing the enlargement and complexity of the device is provided. It will be possible to provide.

It is a schematic block diagram which shows the schematic structure of the information display device which is one Embodiment of this invention, and the peripheral device arranged in the information display device. It is a top view of the automobile equipped with the information display device of one Embodiment of this invention. It is a block diagram explaining the difference of the radius of curvature of the windshield of one Embodiment of this invention. It is a schematic block diagram which shows the region which the driver looks at while driving in one Embodiment of this invention. It is a schematic block diagram which shows the virtual image optical system of the information display apparatus in one Embodiment of this invention. It is a schematic block diagram which shows one Example of the virtual image optical system of the information display apparatus in one Embodiment of this invention. It is a schematic block diagram which shows one Example of the virtual image optical system of the information display apparatus in one Embodiment of this invention. It is a schematic block diagram which shows one Example of the virtual image optical system of the information display apparatus in one Embodiment of this invention. It is a block diagram which shows the arrangement of the image projection apparatus in the information display apparatus in one Embodiment of this invention. It is sectional drawing which shows the outline of the whole structure of the information display device in one Embodiment of this invention. It is sectional drawing explaining the reflection on the mirror surface of one Embodiment of this invention. It is a characteristic diagram which shows the spectral reflectance of the metal reflective film of one Embodiment of this invention. It is a characteristic diagram which shows the spectral reflectance when one layer of a reflective film is formed on the aluminum film of one Embodiment of this invention. It is a characteristic diagram which shows the spectral reflectance when the 5 layers of a reflective film are formed on the aluminum film of one Embodiment of this invention. It is the whole ray diagram of the virtual image optical system which is the 1st Embodiment of this invention, and FIG. ) Represents a state in which the image information of the virtual image plane is viewed by the observer's eyes in the XZ plane. It is a perspective enlargement view of the main part of the virtual image optical system of the first embodiment of the present invention. It is a perspective enlarged view of the lens part of the eyepiece optical system which constitutes the virtual image optical system of the 1st Embodiment of this invention. It is a figure explaining the mapping relation on the inclined slope in the 1st Embodiment of this invention. It is a figure which shows the strain performance for each separation optical path in the 1st Embodiment of this invention. It is a figure which shows the distortion performance of the whole eyepiece optical system in 1st Embodiment of this invention. It is a spot figure of the eyepiece optical system in the 1st Embodiment of this invention. It is a figure explaining the difference between the visual field direction and the distance of a driver in the prior art. It is a figure explaining the mapping relation by an object distance and an image distance. It is a figure explaining the mapping relation in the real image optical system, and the operation of a step filter. It is a figure explaining the mapping relation in the virtual image optical system, and the operation of a step filter.

Hereinafter, an embodiment and various examples of the present invention will be described with reference to the drawings and the like. It should be noted that the following description shows specific examples of the contents of the present invention, and the present invention is not limited to these explanations, and is by those skilled in the art within the scope of the technical idea disclosed in the present specification. Various changes and modifications are possible. Further, in all the drawings for explaining the present invention, those having the same function may be designated by the same reference numerals, and the repeated description thereof may be omitted.

<Embodiment of Information Display Device>
FIG. 1 is a block and a schematic configuration diagram showing a peripheral device configuration of an information display device 1 according to an embodiment of the present invention. Here, as an example thereof, an information display for projecting an image onto a windshield of an automobile is particularly shown. The device will be described.

Since the information display device 1 forms virtual images V1 to V3 at each of a plurality of positions in front of the own vehicle in the driver's line of sight 8, various types of information reflected by the projected member 6 (front glass in the present embodiment) are formed. It is a device (so-called HUD (Headup Display)) that displays information as a virtual image (VI). The projected member 6 may be a member to which information is projected, and is not limited to the above-mentioned front glass. That is, in the information device 1 of the present embodiment, a virtual image is formed at each of a plurality of positions in front of the own vehicle in the driver's line of sight 8 to be visually recognized by the driver. The information to be displayed includes, for example, vehicle information and foreground information taken by a camera (not shown) such as a surveillance camera or an around viewer.

Further, the information display device 1 includes an image projection device 11 that projects an image light for displaying information, an intermediate image forming unit 4 that forms an image of light from the image projection device 11, and the intermediate image forming unit 4. It is provided with an optical component 5 for converging or diverging the imaged image information (image light) formed in the above, and a control device 40 for controlling the image projection device 11. The above-mentioned optical component 5 is a virtual image optical system described below, and includes a concave mirror that reflects light. Further, the light reflected by the optical component 5 is reflected by the projected member 6 and heads toward the driver's line of sight 8 (EyeBox: described in detail later).

The intermediate image imaging (or intermediate image display) unit 4 has a function of forming an image of light from the image projection device 11, for example, by using a microlens array in which microlenses are arranged two-dimensionally. It is composed. In the present embodiment, the optical element 21 and the optical element 22 are arranged between the intermediate image imaging unit 4 and the optical component 5 composed of the concave reflection mirror forming the eyepiece optical system. The primary purpose of arranging the optical elements 21 and the optical elements 22 is to set the virtual image formation positions at a plurality of locations (three locations in the present embodiment) in front of the own vehicle. Further, as a second purpose, aberration correction is performed at a position where the image light from the intermediate image forming unit 4 is separated between the intermediate image forming unit 4 and the optical component 5 forming the eyepiece optical system. To do it. According to the aberration correction by these optical elements, even if the virtual images are formed at different positions, it is possible to display a plurality of virtual images at different magnifications by using the same virtual image optical system.

More specifically, the aberration of the light beam forming the virtual image V1 located in the nearest vicinity is improved by the optical element 21, and at the same time, the aberration of the virtual image V2 located in the middle is corrected by the optical element 22. Further, the virtual image V3 formed at the farthest distance is not provided with an optical element because the aberration is optimally designed in the original virtual image optical system, but it is optimally designed to further improve the aberration correction ability. It goes without saying that the provision of the optical element does not deviate from the technical idea or scope of the present invention.

Further, in this embodiment, for convenience of explanation, an example in which the virtual image generation position is divided into a distant virtual image V3, an intermediate virtual image V2, and a close virtual image V1 and the optical elements 21 and 22 are individually provided has been described. It is not limited to this. For example, in order to continuously change the display position of the virtual image from a distant position to a close position, the spatial optical distance is changed, and the aberration is sufficiently reduced so that the position where the virtual image is continuously generated changes. Therefore, it goes without saying that the provision of a common optical element does not deviate from the technical idea or scope of the present invention.

On the other hand, the control device 30 includes a storage device 31 and a microcomputer (hereinafter referred to as “microcomputer”) 32. The storage device 31 is a non-volatile storage device in which the stored contents can be rewritten. The microcomputer 32 has a ROM 34 that stores a processing program and data that need to retain the stored contents even when the power is turned off, a RAM 33 that temporarily stores the processing program and data, and a process stored in the ROM 34 and the RAM 33. It is mainly composed of a computer having a CPU 35 that executes various processes according to a program.

Among these, the ROM 34 stores a processing program for the microcomputer 44 to execute an information display process for controlling the image projection device 11 so that various information such as vehicle information and foreground information is projected on the projected member 6. ing. Then, at least the navigation system 41 and the driving support electronic control device (hereinafter, referred to as "driving support ECU (Electronic Control Unit)) 42 are connected to the control device 30 as the acquisition source of the vehicle information and the foreground information. There is.

The navigation system 61 is a device that guides the route to the set destination according to the result of collating the current position detected by the position detection device with the map data stored in the map data storage unit. Map data includes various information such as road speed limits, number of lanes, and information on intersections.

From such a navigation system 61, the control device 30 obtains information such as the speed limit and the number of lanes of the road corresponding to the current position where the own vehicle is traveling, the planned movement route of the own vehicle set in the navigation system 51, and the like. It is acquired as foreground information (that is, information displayed in front of the own vehicle by the above-mentioned virtual image).

The driving support ECU 62 is a control device that realizes driving support control by controlling the drive system and the control system according to an obstacle detected as a result of monitoring by the peripheral monitoring device 63, and the driving support control is cruise control. , Includes well-known technologies such as adaptive cruise control, pre-crash safety and lane keeping assist.

The peripheral monitoring device 63 is a device that monitors the situation around the own vehicle, and as an example, a camera that detects an object existing around the own vehicle based on an image taken around the own vehicle, or an exploration wave. It is an exploration device that detects objects existing around the own vehicle based on the result of transmitting and receiving.

The control device 30 acquires information from such a driving support ECU 62 (for example, the distance to the preceding vehicle, the direction of the preceding vehicle, the position where an obstacle or a sign exists, etc.) as foreground information. Further, an ignition (IG) signal and own vehicle state information are input to the control device 30. Among these information, the own vehicle state information is information acquired as vehicle information, and indicates that, for example, a predetermined abnormal state such as the remaining amount of fuel of the internal combustion engine or the temperature of the cooling water has occurred. Contains warning information. It also includes information such as the operation result of the turn signal, the traveling speed of the own vehicle, and the shift position. The control device 30 described above is activated when an ignition signal is input. The above is a description of the entire system of the information display device according to the embodiment of the present invention.

<First embodiment>
Next, further details of the virtual image optical system 5 and the image projection device 11 according to the embodiment of the present invention will be described below.

FIG. 2 is a top view of an automobile equipped with the information display device 1 according to the embodiment of the present invention, and a windshield as a projected member 6 is present in the front portion of the driver's seat of the automobile main body 101. The angle of inclination of this windshield with respect to the vehicle body differs depending on the type of automobile. Furthermore, the inventors also investigated this radius of curvature in order to realize an optimum virtual image optical system. As a result, as shown in FIG. 3, the windshield has a radius of curvature Rh in the horizontal direction parallel to the ground plane of the automobile and a radius of curvature Rv in the vertical direction orthogonal to the horizontal axis. It was found that Rv generally has the following relationship.
Rh> Rv

It was also found that this difference in radius of curvature, that is, Rh with respect to Rv, is often in the range of 1.5 to 2.5 times.

Next, the inventors investigated commercially available products regarding the inclination angle of the windshield. As a result, although it varies depending on the vehicle body type, it was 20 to 30 degrees for the light vehicle and the 1Box type, 30 to 40 degrees for the sedan type, and 40 degrees or more for the sports type. Therefore, in the present embodiment, the difference between the horizontal radius of curvature Rh parallel to the ground plane of the automobile of the front glass and the vertical radius of curvature Rv orthogonal to the horizontal axis and the inclination angle of the front glass are considered. , I designed the imaginary optical system.

More specifically, since the horizontal radius of curvature Rh and the vertical radius of curvature Rv of the front glass, which is the projected member, are significantly different from each other, they are perpendicular to the horizontal axis of the front glass and this axis with respect to the optical axis (Z axis). Good aberration correction was realized by providing an optical element that is asymmetrical to the horizontal axis in the virtual image optical system. The lens data of the obtained virtual image optical system will be described in detail later.

Further, as shown in FIG. 1, a rotation-asymmetrical shape capable of realizing an optical system in which the object plane positions are on the same plane for a plurality of virtual image planes having different viewing ranges and virtual image distances. The first embodiment of the virtual image optical system using the free curved lens and the free curved mirror (described in this specification by exemplifying a free curved mirror based on a concave shape) will be described below. ..

The configuration of the virtual image optical system according to the first embodiment of the present invention will be described with reference to FIG. FIG. 15 is an overall ray diagram of the virtual image optical system 5 according to the embodiment of the present invention shown in FIG. 1, and in particular, FIG. 15A is an observer's image information of the virtual image plane 7 in the YZ plane. FIG. 15B shows the state of viewing with the eyes, and FIG. 15B shows the state of viewing the image information of the virtual image plane 7 in the XZ plane with the eyes of the observer. In the YZ plane, the right eye and the left eye overlap (see reference numeral 8), and in the XZ plane, the right eye and the left eye are seen separately.

FIG. 16 is an enlarged perspective view of a main part of the virtual image optical system 5 of the first embodiment. Further, FIG. 17 is an enlarged perspective view of the lens portion of the eyepiece optical system 5a constituting the virtual image optical system 5 according to the first embodiment. As shown in FIGS. 16 and 17, each of the free-form surface lens 54 and the free-form surface mirror 56 is configured to have a rotationally asymmetrical shape. The optical element 51, the convex lens 52, and the concave lens 53 have a large amount of eccentricity (no eccentricity on the front and rear surfaces). Further, FIG. 18 is a diagram illustrating a mapping relationship on an inclined slope.

As shown in FIG. 16, the virtual image optical system 5 includes a step filter (optical element) 51 and a convex lens 52 having a positive refractive power in this order from the intermediate image display unit (or image display unit such as a flat display) 4 side. , A concave lens 53 having a negative refractive power, a rotation-asymmetric free-curved lens 54, a cylinder mirror 55, a rotation-asymmetric free-curved mirror 56, and a front glass 6 are arranged side by side. The difference in the radius of curvature in the horizontal direction and the vertical direction of the windshield 6 is canceled by adding the cylinder mirror 55. Further, the rotation-asymmetric free-form surface lens 56 of the reflecting surface corrects the distortion of the virtual image.

Here, the lens data obtained in the virtual image optical system 5 of the first embodiment is shown in Tables 1 and 2 below.

Table 1 is a table showing the lens data of the image projection device 11 according to the first embodiment of the present invention. In the lens data shown in Table 1, the radius of curvature is represented by a positive sign when the center position of the radius of curvature is in the traveling direction, and the interplane distance is from the apex position of each surface to the apex position of the next surface. It represents the distance on the optical axis. For example, at a virtual image distance of 18 m, the thickness of the step filter corresponding to the optical element 23 shown in FIG. 6 is 27.439 mm, and at a virtual image distance of 30 m, the thickness of the step filter corresponding to the optical element 24 shown in FIG. 6 is At 14.556 mm and a virtual image distance of 100 m, the thickness of the step filter is 0 mm.

Further, the eccentricity is a value in the Y-axis direction, the tilt is the rotation around the X-axis in the YZ plane, and the eccentricity / tilt acts in the order of eccentricity and tilt in the corresponding plane, and in "normal eccentricity", eccentricity. -The next plane is placed at the position of the face-to-face distance on the new coordinate system where the collapse has acted. Decenter and return eccentricities and collapses act only on that aspect and do not affect the next aspect.

The glass material name PMMA is plastic acrylic, and the glass material name 58.3 represents a material having a refractive index of 1.58 and an Abbe number of 30.

Table 2 is a diagram of free-form surface coefficients of the lens data of the image projection device 11 according to the first embodiment of the present invention. The free-form surface coefficient in Table 2 is obtained by the following equation (Equation 1).

The free-form surface coefficient C _j is a shape that is rotationally asymmetric with respect to each optical axis (Z-axis), and is a shape defined by a component of a conical term and a component of a polynomial term of XY. For example, when X is quadratic (m = 2) and Y is cubic (n = 3), the coefficient of C ₁₉ such that j = {(2 + 3) ² + 2 + 3 × 3} / 2 + 1 = 19 corresponds. Further, the position of each optical axis of the free curved surface is determined by the amount of eccentricity / tilt in the lens data in Table 1.

Further, the anamorphic aspherical coefficient of the image projection device 11 according to the first embodiment of the present invention is obtained by the following equation (Equation 2). The cute (= 1 / rdy) and cup (= 1 / rdx) of (Equation 2) were rdy = 9686 mm and rdx = 5531 mm in Table 1, and all other coefficients were set to 0.

Further, the values such as the eye box size and the viewing angle of the eyepiece optical system constituting the virtual image optical system 5 of the first embodiment of the present invention are shown below in the order of the horizontal direction and the vertical direction.
Eye box size 100 x 50 mm
Effective size of image light on screen board 40.70 x 18.80 mm
Viewing angle (total angle of view) 5.4 x 1.8 degrees Separation optical path (vertical viewing direction, virtual image size, virtual image distance)
1.8-2.2 degrees, 1698 x 126 mm, 18 m
1.1-1.5 degrees, 2830 x 210 mm, 30 m
0.4-0.8 degrees, 9432 x 698 mm, 100 m

Next, the optical performance of the virtual image optical system 5 in the above-mentioned first embodiment, particularly the distortion performance, will be described with reference to FIGS. 19 to 21.

19 and 20 are diagrams showing the distortion performance of the virtual image optical system 5 in the image projection device 11 of the first embodiment of the present invention. FIG. 21 is a spot view of the eyepiece optical system in the image projection device 11 of the first embodiment of the present invention.

FIG. 19 is a diagram showing the distortion performance of each separated optical path in the first embodiment of the virtual image planes 71, 72, and 73 shown in FIG. 15, and from this figure, a rectangular virtual image on each virtual image plane. It can be seen that is realized. When the viewing angle is calculated from the virtual image sizes on the virtual image planes 71, 72, and 73, the horizontal viewing angle (total angle of view) of the viewing range F1 is 2 × tan (1698/2/18000) = 5.4 degrees, and the field of view. The horizontal viewing angle (total angle of view) of the range F2 is 2 × tan (2830/2/30000) = 5.4 degrees, and the horizontal viewing angle (total angle of view) of the viewing range F3 is 2 × tan (9432/2). / 100,000) = 5.4 degrees. Since the horizontal viewing angles on the virtual image planes 71, 72, and 73 have the same value, in FIG. 20, the visual field ranges on the virtual image planes 71, 72, and 73 are collectively represented. It can be seen that F3 is displayed at a position shifted in the vertical direction.

FIG. 21 shows a spot diagram in which object points are arranged on the virtual image planes 71, 72, and 73, and a spot diagram on the screen plate 4 is calculated, and good optical performance is realized. In this spot diagram, the size of the eye box 9 is a spot diagram with a total luminous flux of 100 mm horizontal × 50 mm vertical, and in the case of a virtual image seen by an actual driver, the size of the iris of the human eye (maximum). The spot diagram at (which is said to be φ7 mm) is significantly better than that of FIG. 21.

Therefore, according to the present embodiment, it is possible to provide an information display device capable of simultaneously displaying as a virtual image in different viewing directions at different virtual image distances by using a virtual image optical system using a free curved lens and a free curved mirror.

As shown in FIGS. 24 (a) to 24 (c), the driver generally checks the vehicle in front (lights the brake lamp and right / left turn lamp) and checks the road surface in front of the vehicle while driving. We also check (presence or absence of falling objects, etc.) and bicycles and pedestrians at the end of the road in front of us. According to the present embodiment, the warning information about the preceding vehicle is displayed in the virtual image range corresponding to the position of the preceding vehicle, and the falling object is displayed in the corresponding virtual image range at the position of the road surface of the road in front of the virtual image range. It is possible to display such as displaying the existence. Further, according to the present embodiment, it is possible to simultaneously display an image on a plurality of virtual image planes located at different virtual image distances and in different viewing directions.

In addition, since the driver also checks information such as speedometers and fuel gauges, by equipping the information display device, information on various instruments can be displayed in front of the driver as a virtual image, so that the driver's line of sight can be seen. Driving safety can be improved because the movement is reduced and the time required for focusing the eyes can be shortened.

By the way, the distance from the driver is different between the vehicle in front in the foreground, the road surface in front of it, and the bicycle / pedestrian at the end of the road in front of it. By changing it, the time required for focusing the eyes can be further shortened, and the driving safety can be improved.

Next, with reference to FIGS. 23 to 25, the mapping relationship due to the difference in the virtual image distance of the information display device is organized, and the problem to be solved is quantitatively shown.

FIG. 23 is a diagram illustrating a mapping relationship (in a real image optical system) between an object distance and an image distance. As the distance L from the image plane lens 201 to the object surface 202 decreases, the distance a to the image plane 203 increases. FIG. 24 is a diagram for explaining the mapping relationship in the real image optical system and the operation of the step filter, and shows the movement amount δ of the focal position at the focal length = 440 mm and the object distance L = 100 to 10 m. In the real image optical system, the focal position on the short-distance side is farther than the focal position on the long-distance side. Here, when the filter 251 having a thickness d and a refractive index N is arranged between the imaging lens 201 and the real image plane 203, it is the difference between the physical length d and the optical length d / N of the filter 251 d (1-1). The position of the real image plane 203 can be separated by the amount of 1 / N). In the real image optical system, the position of the real image plane on the short distance side is farther than the position of the real image plane on the long distance side. Therefore, on the optical path on the long distance side, between the image lens 201 and the real image plane 203. By arranging the filter 251, it is possible to arrange the physical real image plane position on the short-distance side and the physical real image plane position on the long-distance side on the same plane.

Similarly, FIG. 25 is a diagram for explaining the mapping relationship in the virtual image optical system and the operation of the step filter, and shows the movement amount δ of the object position at the focal length = 440 mm and the virtual image distance L = 100 to 10 m. There is. In the virtual image optical system, the object position on the long-distance side is farther than the object position on the short-distance side. Similarly, when a filter 351 having a thickness d and a refractive index N is arranged between the eyepiece 301 and the object surface 302, it is the difference between the physical length d and the optical length d / N of the step filter 351 d (1). The position of the object surface 203 can be separated by the amount of -1 / N). In the phantom image optical system, the object surface position on the long-distance side is farther away than the object surface position on the short-distance side, so that between the eyepiece lens 301 and the object surface 302 on the optical path on the short-distance side. By arranging the filter 351, it is possible to arrange the physical object surface position on the short-distance side and the physical object surface position on the long-distance side on the same plane. For example, when the virtual image distance L = 20 to 10 m, the position of the object surface 302 deviates by δ = 9.1 mm, so that a filter 351 with d = δ / (1-1 / N) = 26.6 mm is required. Similarly, when the virtual image distance L = 100 to 18 m, the position of the object surface 302 deviates by δ = 8.6 mm, so that a filter 351 with d = 25.2 mm is required.

<Second embodiment>
Next, with reference to FIG. 5, the basic structure of the optical system of the information display device according to the second embodiment of the present invention will be described. The optical system shown in FIG. 5 includes a forming unit 10 and an eyepiece optical system 5a constituting the virtual image optical system 5. That is, it has a configuration in which the image light emitted from the projection optical system 20 is reflected on the windshield 6 of an automobile (not shown) and thus incident on the driver's eye 8.

More specifically, the luminous flux emitted from the backlight 100 to the liquid crystal display panel 2 is incident on the relay optical system as an image luminous flux including the image information displayed on the liquid crystal display panel 4a. The image information on the liquid crystal display panel 2 is magnified by the image forming action of the relay optical system 3, and then magnified and projected onto the intermediate image forming unit 4. The points P1, P2, and P3 on the liquid crystal display panel 2 correspond to the points Q1, Q2, and Q3 of the intermediate image forming unit 4, respectively. By using the relay optical system 3, a liquid crystal display panel having a small display size can be used. Since the backlight 100, the liquid crystal display panel 2, the relay optical system 3, and the intermediate image imaging unit 4 form image information (video information) on the intermediate image imaging unit 4, they are collectively images. It is called a forming unit 10.

Next, the image information on the intermediate image forming unit 4 is projected onto the windshield 6 by the eyepiece optical system 5a, and the light flux reflected by the windshield 6 reaches the position of the observer's eye 8. From the observer's point of view, the relationship is established as if the image information of the virtual image surface 7 is being viewed. The points Q1, Q2, and Q3 on the intermediate image forming unit 4 correspond to the points V1, V2, and V3 on the virtual image plane 7, respectively. The range in which the points V1, V2, and V3 on the virtual image plane 7 can be seen even if the position of the eye 8 is moved is the so-called eye box 9. As described above, the virtual image optical system of the present invention can display an object (spatial image) and an image (virtual image) in front of the observer's eyes, similar to the eyepiece of a camera finder or an eyepiece of a microscope. It is a possible optical system.

Further, the intermediate image forming unit 4 is composed of a microlens array in which microlenses are arranged two-dimensionally. That is, due to the diffusing action, the spreading angle of the light flux emitted from the intermediate image forming unit 4 is increased, whereby the size of the Ivoc 9 is set to a predetermined size. The diffusing action of the intermediate image forming unit 4 can also be realized by incorporating the diffusing particles.

Further, in the second embodiment of the present invention, as shown in FIG. 5, the position where the virtual image is generated corresponds to the position between the eyepiece optical system 5a constituting the virtual image optical system 5 from the intermediate image imaging unit 4 side. , An optical element for aberration correction is arranged. Specifically, the optical element 21 for correction is arranged at the position where the light beam corresponding to the closest position V1 passes, and the virtual image generation position of the virtual image optical system 5 is brought closer to reduce the magnification at the same time. Reduces distortion and aberrations that occur in virtual images. Next, a correction optical element 22 is arranged at a position where the light beam corresponding to the virtual image V2 established at the intermediate position passes, and the virtual image generation position of the virtual image optical system 5 is established at the intermediate position to achieve medium magnification. At the same time, the distortion and aberration generated in the virtual image are reduced. Then, the correction optical element described above does not have to be arranged at the position where the light flux corresponding to the virtual image V3 established farthest from the observer passes, that is, the eyepiece constituting the virtual image optical system 5 is formed. Optimal design of the optical system 5a.

In this way, the eyepiece optical system 5a is optimally designed for the virtual image V3 that is established at the farthest point as a reference, while the optical for correction is applied to V2 that is established at an intermediate distance and V1 that is established in the vicinity. By arranging the elements respectively, not only the optical distance between the intermediate image imaging unit 4 and the eyepiece optical system 5a is shortened, but also the distortion and aberration of the virtual image established at each image position are corrected. It has the optimum structure.

Further, in order to reduce the distortion and aberration of the virtual image, a plurality of intermediate image imaging units are used (the same effect can be obtained by dividing them), and each of them is adjusted to the virtual image position to be optimal for the eyepiece optical system 5a. In that case, by directing the direction of the intermediate image forming portion toward the entrance pupil direction of the eyepiece optical system 5a, the image light is more efficiently incident on the eyepiece optical system 5a. Is possible.

In the present embodiment, the light beam corresponding to the virtual image V1 formed in the vicinity, the light beam corresponding to the virtual image V2 formed in the middle, and the light beam corresponding to the virtual image V3 formed in the distance are separated and incident on the virtual image optical system 5. By arranging an optical system for correction corresponding to each virtual image at the position (shown as between the eyepiece optical system and the flat display in FIGS. 5 and 6), the distortion and aberration of the virtual image are corrected. I explained that there is. However, the present invention is not limited to this, and for example, even if the position where the virtual image is formed is continuous from a distance to a vicinity, the optical distance between the virtual image optical system 5 and the intermediate image imaging unit 4 is set. It goes without saying that the adaptive optics element may be arranged so as to correspond to the position where the virtual image is formed, and this does not deviate from the technical idea or scope of the present invention.

<Third embodiment>
Next, the optical system of the information display device according to the third embodiment of the present invention will be described with reference to FIG.

In the example of this figure, a flat display (for example, a liquid crystal display panel) 4a is used as an image source. The luminous flux emitted from the backlight 100 is incident on the eyepiece optical system 5a constituting the virtual image optical system 5 as an image luminous flux including the image information displayed on the liquid crystal display panel 4a. Similar to the second embodiment described above, an optical element for aberration correction is arranged between the liquid crystal display panel 4a and the eyepiece optical system 5a constituting the virtual image optical system 5 according to the position where the virtual image is generated. Specifically, the optical element 23 for correction is arranged at the position where the light beam corresponding to V1 located closest to the passage passes, and the virtual image generation position of the virtual image optical system 5 is brought close to the vicinity, and at the same time, the virtual image is generated. Reduce distortion and aberrations. Next, a correction optical element 24 is arranged at a position where the light beam corresponding to the virtual image V2 established at the intermediate position passes, and the virtual image generation position of the virtual image optical system 5 is established at the intermediate position to achieve medium magnification. At the same time, it reduces the distortion and aberrations that occur in virtual images. On the other hand, the eyepiece optical system 5a constituting the virtual image optical system 5 is provided so that the correction optical element does not have to be arranged at the position where the light flux corresponding to the virtual image V3 established farthest from the observer passes. Optimal design.

Also in this third embodiment, similarly to the second embodiment, the virtual image optical system 5 is optimally designed for the virtual image V3 established at the farthest distance from the observer so as to be a design standard for the virtual image optical system 5. However, it is assumed that the correction optical elements are arranged for V2 established at an intermediate distance and V1 established in the vicinity. According to this, since the optical distance between the planar display 4a and the eyepiece optical system 5a can be adjusted to each, the structure is optimal for correcting the distortion and aberration of the virtual image established at each position. ..

FIG. 7 shows an example in which a plurality of flat displays (for example, a liquid crystal display panel) 4b, 4c, 4d are used as an image source. The luminous flux emitted from the backlights 100b, 100c, and 100d is incident on the virtual image optical system 5a as an image luminous flux including the image information displayed on the liquid crystal display panels 4b, 4c, and 4d. The functions of the virtual image optical system 5a and the correction optical elements corresponding to the respective virtual images V3, V2, and V1 are the same as those of the second embodiment shown in FIG. 6, and the description thereof will be omitted here.

FIG. 8 shows another example in which a plurality of flat displays (for example, liquid crystal display panels) 4b, 4c, and 4d are used as an image source. Here, too, the luminous flux emitted from the backlights 100b, 100c, and 100d is incident on the eyepiece optical system 5a as an image luminous flux including the image information displayed on the liquid crystal display panels 4b, 4c, and 4d. In this example, as is clear from the figure, by tilting each flat display in the direction of the entrance pupil of the eyepiece optical system 5a, it is possible to capture the image light more efficiently. The function of the correction optical element corresponding to each of the virtual images V3, V2, and V1 is the same as that of the second embodiment shown in FIG. 6, and the description thereof will be omitted here.

The unique effects obtained by using the plurality of flat displays (liquid crystal display panels) described above are summarized below.

(1) By using a plurality of liquid crystal display panels as an image source, the resolution of composition can be increased. As a result, the amount of information of the entire virtual image can be increased, and as shown in FIG. 3, it is possible to establish the virtual image over almost the entire area of the windshield 6. Normally, the image display area 1 (a) or the image display area 1 (c), or the image display areas 1 (a) and 1 ( A virtual image is established in both of c). As a result, as shown in FIG. 4, the image information and attention alert from the peripheral monitoring device also shown in FIG. 1 are superimposed on the front view that the driver of the traveling automobile 101 is gazing at while driving. Information, as well as information from the navigation system, can be displayed, and so-called virtual reality can be realized. Furthermore, even if you try to make a right turn, it is safe to display the information of the pedestrian, which is a safety issue for driving, by the peripheral monitoring device, and then display the information of the alert on the captured video information. It is an effective aid for driving.

Further, for the automobile 102 traveling from the left in the traveling direction, if there is a safety problem, the driver's safety awareness is strengthened by intermittently displaying a warning image in the image display area 2 of FIG. Can be useful for.

(2) By arranging a plurality of flat displays (liquid crystal display panels) at desired positions within the object surface range of the virtual image optical system, the obtained virtual image formation position and magnification can be appropriately controlled.

(3) Further, by tilting the direction of each liquid crystal display panel toward the entrance pupil direction of the eyepiece optical system 5a, the utilization efficiency of the image light can be improved and a bright virtual image can be obtained. Similarly, at the position where the liquid crystal display panel is arranged, the degree of freedom in design can be improved by tilting the liquid crystal display panel so as to be advantageous for correcting the aberration and distortion of each virtual image that is established.

As a result, the degree of freedom in design is increased as compared with the virtual image optical system shown in FIG. 6, the resolution performance and the degree of freedom in aberration correction and distortion correction are improved, and a virtual image seen from the driver's point of view is desired. It is possible to establish at the position of. In FIG. 7 above, as an example, an example in which three liquid crystal display panels 4b, 4c, and 4d are arranged in parallel is described, but the present invention is not limited to this, and for example, as shown in FIG. 8, the eyepiece optical system 5a is shown. Each of them may be tilted and arranged in correspondence with the optical axis direction of the above, or a flat display may be arranged in a matrix as shown in FIG. 9, and further, the above-mentioned adaptive optics element may be inserted. Needless to say. At this time, it is also effective to improve the degree of freedom of distortion correction and aberration correction by tilting each panel with respect to the optical axis of the virtual image optical system.

<Other embodiments>
FIG. 10 is a cross-sectional view showing an outline of the entire structure including a liquid crystal display panel 4a and a backlight 100 as an image light source in an information display device according to another embodiment of the present invention. The light funnel 44 reduces the divergence angle of the emitted light from the white LED 46, which is a solid light source, and makes the intensity distribution of the emitted light uniform. After that, the light is made substantially parallel by the optical element 43, and is aligned with a single polarization in the PBS 45 for polarization conversion. After that, it is reflected by the reflecting surface 41 and incident on the liquid crystal display panel 4a. At this time, an optical element 17 for controlling the angle of incident light flux on the liquid crystal display panel 4 is provided so that the image light flux obtained by the liquid crystal display panel 4a has excellent contrast performance.

According to this, polarizing plates are provided on the light incident surface and the light emitting surface of the liquid crystal display element 4a, and it is possible to obtain an image luminous flux having excellent contrast performance. Further, it is also possible to provide a λ / 4 plate 46 on the exit surface of the liquid crystal display panel 4a so that the emitted light is circularly polarized. As a result, the driver can monitor a good virtual image even when wearing polarized sunglasses.

As described above, when a bright virtual image image is to be obtained by using the liquid crystal display panel 4a using polarization as the image light source, for example, the eyepiece optical system 5a constituting the virtual image optical system 5 according to the first embodiment described above ( The base material of the free curved mirror 56 and the cylinder mirror 55 constituting (the enlarged perspective view of the lens portion is shown in FIG. 17) secures the shape accuracy of the reflective surface by heating and compressing a plastic molded mirror or a glass plate on the surface. Form a reflective film. At this time, in order to obtain a bright virtual image, it is necessary to increase the reflectance of the reflective film.

At this time, in order to ensure the uniformity of the brightness and chromaticity of the obtained virtual image, (1) the spectral reflectance in the visible light region (380 nm to 780 nm) is high, and (2) the uniform reflectance characteristics. Is important. FIG. 12 shows the spectral reflection characteristics of a general metal. As a metal, silver is the most excellent as it satisfies the above two requirements.

However, since there were problems in durability (compounding and a large decrease in reflectance) and price, improvements were made and a silver alloy reflective film with excellent durability is now in practical use.

Another excellent property of the reflective film of silver or silver alloy is that, as shown in FIGS. 11 and 12, the reflectance of the reflective film obtained by forming a film of this silver or silver alloy on a substrate is The angle of incidence dependence is small, and the wavelength dependence of P and S waves is also small. Therefore, when a liquid crystal display panel is used as the image light source of the present embodiment and a specific polarization is used, S polarization is used. As a result, a bright and good virtual image can be obtained because the reflectance of S polarization is high.

On the other hand, in order to reduce the cost of the reflective film, aluminum is used as the reflective film in recent years, and an augmented reflective film that improves the reflectance by the interference effect of light is actively provided on the surface thereof. FIG. 13 shows the spectral reflectance when a single-layer reflective film is formed on the surface of the aluminum reflective film. In the case of vertical incidence (incident angle is 0 degrees) compared to the reflectance of aluminum shown in FIG. 12, the reflectance in the visible region can be improved by about 5% by providing a single-layer antireflection film, but at the same time, the reflectance is reflected. It has incident angle dependence, wavelength dependence, and polarization dependence (reflectance differs between S polarization and P polarization, and the reflectance of S polarization is high).

FIG. 14 shows the characteristics when the number of reflective films is 5 in order to further increase the reflectance. The reflectance is further improved by about 3% in vertical incident with respect to the characteristics of the single-layer antireflection film shown in FIG. 13, but the wavelength region that maintains this reflectance becomes a narrow band and the angle of incidence dependence. Since it becomes even larger, it is necessary to design while controlling the angle of light incident on the mirror in order to obtain desired reflection characteristics and obtain uniform brightness and one-color reproducibility in the entire display screen area.

As described above, the reflective film formed on the mirror is preferably a silver or silver alloy reflective film having less wavelength dependence, angle dependence, and polarization dependence.

On the other hand, in order to reduce the cost, it is necessary to provide a reflective film on the aluminum reflective film to increase the reflectance. At this time, as shown in FIGS. 13 and 14, since the reflectance has an incident angle dependence and a wavelength dependence, there is no practical problem if the incident angle of the image ray on the mirror is 60 degrees or less, and 40 If it is less than or equal to the degree, uniform brightness and chromaticity can be realized in the entire screen area of the obtained virtual image.

On the other hand, as shown in FIG. 10, a λ / 4 plate 46 is provided on the emission surface of the liquid crystal display panel 4a, and the emitted light is circularly polarized, so that the reflectance is different between S polarization and P polarization. , The reflectance of S polarization is high) may be reduced.

Further, by providing the optical member 47, which is a combination of an ultraviolet reflecting film or an ultraviolet reflecting film and an infrared reflecting film, at a position closest to the virtual image optical system 5, even if external light (sunlight) is incident, the liquid crystal is displayed. Since the display panel and the polarizing plate can be reduced from the temperature rise and damage thereof, the effect that the reliability of the information display device is not impaired can be obtained.

<Others>
The main configurations of the information display device according to each embodiment of the present invention have been described in detail above, but further, they will be summarized and the details of other configurations will be described below.

Among them, first, the image projection device is a flat display such as a single plate LCOS (Liquid Crystal On Silicon) provided with a TFT type color liquid crystal panel and a color filter, and an OLED (Organic Light Emitting Diode). On the other hand, the image source (intermediate image display unit) is a small liquid crystal panel or an image display element such as a DMD (Digital Mirror Device) that modulates the light intensity according to the image signal, and the modulated light is projected as a projection means. There is a method of magnifying and projecting on the intermediate image display unit, and in addition, the same image information as the above-mentioned image projection device can be obtained by scanning the light source light with a fine mirror of MEMS (Micro Electro Electro Mechanical Systems). Therefore, the best image plane of the projection means and the image plane obtained by scanning are substantially matched with the surface shape of the intermediate image display unit, and the virtual image optical system is designed as a non-planar surface, for example, a spherical surface, an aspherical surface, or a free curved surface. You can also increase the degree of freedom. Further, a plurality of intermediate image display units may be installed to display the video separately (however, in FIGS. 1 and 5, the intermediate image display unit is displayed as one).

In addition, the imaginary optical system is optimally designed including the difference between the windshield's radius of curvature in the vehicle horizontal direction and the radius of curvature in the vertical direction of the windshield, which was the member to be projected in the prior art, and the windshield and the image projection device or the middle. A concave mirror with a concave surface facing the windshield is placed between the image display units, thereby enlarging the image projected on the image projection device or the intermediate image display unit and reflecting it on the windshield. .. At this time, a plurality of optical elements are arranged between the concave mirror and the image projection device or the intermediate image display unit, and on the other hand, an enlarged image of the image formed corresponding to the viewpoint position of the driver. The image luminous flux forming the (virtual image) passes through the plurality of optical elements arranged between the image projection device or the intermediate image display unit, and at that time, the optical elements arranged at positions separated from each other are used. pass. Therefore, by dividing the optical element according to each luminous flux and performing optimum aberration correction, it is possible to obtain a highly visible virtual image corresponding to a plurality of viewpoint positions of the driver.

Further, as shown in FIG. 7, high resolution can be realized at low cost by arranging a plurality of small image display elements to form an image projection device. Further, by changing the arrangement location of the plurality of image display elements with respect to the above-mentioned virtual image optical system, it is possible to control the position where the virtual image is generated and its magnification when viewed from the driver.

More specifically, in the present invention, the virtual image obtained by being reflected by the upper part of the windshield (the upper part in the vertical direction of the vehicle body) needs to be imaged farther. Therefore, in order to satisfactorily image the image light beam emitted from the upper part of the image projection device and the intermediate image display unit on which the corresponding image is displayed, the above-mentioned concave mirror and the image projection device or the intermediate image display unit are used. The focal length f1 of the composition is shortened by a plurality of optical elements arranged between the two, or an optical member having a refractive index of more than 1.0 is inserted to lengthen the optical distance L1. The virtual image obtained by being reflected by the lower part in the vertical direction of the vehicle body needs to have a long composite focal length f2 or a short optical distance L2 in order to form an image closer to the image. In other words, the relationship between the two should be set so that f1 <f2. In order to realize the object of the present invention, as described above, the image projection device and the intermediate image display unit may be divided into several parts to display necessary information, or continuous information display may be performed. It is also possible.

Further, in one embodiment of the present invention shown in FIG. 1, the virtual image V3 obtained by being reflected by the upper part of the windshield (the upper part in the vertical direction of the vehicle body) needs to be imaged farther. Therefore, in order to satisfactorily image the image light beam emitted from the upper part of the image projection device or the intermediate image display unit on which the corresponding image is displayed, the above-mentioned concave mirror and the image projection device or the intermediate image display unit are used. The combined focal length f1 of the plurality of optical elements arranged between the two is short, and conversely, the virtual image V1 obtained by being reflected by the lower part of the front glass (lower part in the vertical direction of the vehicle body) needs to be imaged closer. Therefore, in order to satisfactorily image the image luminous flux emitted from the lower part of the image projection device or the intermediate image display unit on which the corresponding image is displayed, the concave mirror and the image projection device or the intermediate image display unit described above are used. The combined focal length f2 of the plurality of optical elements arranged between them may be set relatively long.

Further, in one embodiment of the present invention, the radius of curvature in the horizontal direction (parallel to the ground) of the front glass and the radius of curvature in the vertical direction (direction perpendicular to the horizontal direction of the front glass) are different, so that the driver observes the imaginary image. By arranging optical elements having different axial symmetries with respect to the optical axis in the imaginary image optical system in order to correct the screen distortion, the above-mentioned distortion correction is realized.

Next, in one embodiment of the present invention, the image plane is configured as a flat panel display. Specifically, it is a flat display such as a single plate LCOS (Liquid Crystal On Silicon) provided with a TFT type color liquid crystal panel and a color filter, and an OLED (Organic Light Emitting Diode). The display screen size is preferably about 1 inch to 5 inches, and preferably about 3 inches in consideration of effective use of video light. Further, as shown in FIG. 7, it is possible to obtain a desired resolution by combining a plurality of small flat displays.

In this case, since the image projection device itself is the image source of the virtual image optical system, the display surface is flat. Therefore, as the degree of freedom in design, the inclination of the front glass to be inclined with respect to the optical axis of the virtual image optical system is considered. There is a degree of freedom such as correcting the trapezoidal distortion. Further, in the information display device using a plurality of planar displays, the above-mentioned virtual image generation position and magnification can be similarly controlled by changing the location where the small planar display is arranged with respect to the virtual image optical system.

Further, an optical element having a condensing action is arranged between the image plane and the virtual image optical system so that the image light beam reaches the driver's viewpoint position, and the light emitted from the image plane is operated through the virtual image optical system. Efficiently reach the human eye. Further, in an image projection device that uses only specific polarization such as a single plate LCOS (Liquid Crystal On Silicon) equipped with a TFT type color liquid crystal panel and a color filter, and an OLED (Organic Light Emitting Diode), the light source light is polarized and converted. By providing an optical element that extracts only the desired polarization component between the light source and the image projection device, the light source light can be effectively used. Further, by controlling the divergence angle of the light source light and using only the angle component having high contrast performance in the output light from the above-mentioned image projection device, it is possible to improve the contrast performance of the image.

In addition, when there are multiple viewpoint positions of the driver due to changes in the driver, the reflective surface of the front glass is the center position of the radius of curvature in the vertical direction of the vehicle body and the radius of curvature in the horizontal direction of the vehicle body and the driver. The position of the eye is different, and therefore the distortion of the image obtained by the virtual image is different. Therefore, for example, in order to measure the viewpoint position of the driver in a car, the position of the pupil is measured by a camera or the like, and the image displayed on the image projection device is distorted so as to correct the distortion generated in the virtual image in advance. It is good to leave it.

Further, the distortion of the displayed characters and figures caused by the shape of the front glass reflective surface and the position of the driver's viewpoint can be obtained by changing the aspect ratio of the characters and figures according to the position of the displayed image. The shape of the virtual image to be viewed can be expressed more naturally (the aspect ratio is more correct).

As a result of the above, according to the information display device according to the embodiment of the present invention, it is possible to form a highly visible virtual image at a plurality of viewpoint positions (different distances) of the driver. Further, according to the information display device according to the embodiment of the present invention, it can be realized with a simpler configuration as compared with the techniques shown in Patent Document 1 and Patent Document 2 described above, that is, the device structure is enlarged. And complexity can be suppressed as much as possible.

Further, in the information display device according to the embodiment of the present invention, as compared with the technique described in Patent Document 2, it is not necessary to adjust the focal length of the projection means at high speed according to each imaging means, and the cost is low. With a simple configuration, a virtual image can be formed at a position suitable for the driver's line of sight, such as a short distance (corresponding to the lower part of the windshield) or a long distance (corresponding to the upper part of the windshield). As a result, it is possible to provide an information display device that is easy for the user to use.

1 ... Information display device, 100 ... Backlight, 2 ... Liquid crystal display panel, 3 ... Relay optical system, 4 ... Intermediate image imaging unit (diffusing plate), 5a ... Eyepiece optical system (optical component), 5 ... Virtual image optical system , 6 ... Projected member (front glass), 7 ... Virtual image surface, 8 ... Eye box, 9 ... Observer's eye, 10 ... Image forming unit, 11 ... Image projection device, 17 ... Optical element, 20 ... Projection optical system , 21 ... Optical element, 22 ... Optical element, 23 ... Optical element, 41 ... Reflective surface, 42 ... λ / 2 plate, 43 ... Optical element, 44 ... Light funnel, 45 ... PBS, 46 ... Solid light source, 47 ... Ultraviolet rays And infrared reflective sheet, 48 ... λ / 4 plate, 51 ... optical element (step filter), 52 ... convex lens (first optical element), 53 ... concave lens (second optical element), 54 ... free curved lens, 55 ... cylinder Mirror (reflection mirror), 56 ... Free curved mirror (reflection mirror, concave mirror), V1, V2, V3 ... Virtual image.

Claims (10)

It ’s a head-up display device.
Display elements that generate video information and
An optical system that establishes a virtual image in front of the observer based on the image light emitted from the display element is provided.
The optical system includes an optical element arranged on the optical path of the image light.
The optical element continuously changes the display position of the virtual image from a predetermined near position to a predetermined distant position at different viewing directions and virtual image distances in front of the observer from the viewpoint position of the observer. Is configured in
Between the near position and the distant position, as a plurality of positions, a first position in front of the observer, a second position having a virtual image distance farther than the first position, and the second position. Including the third position where the virtual image distance is farther than the position,
The optical element has one common optical element, and the common optical element is used when an image light beam passes in the direction of the optical axis of the image light in a direction perpendicular to the optical axis of the image light. It is configured to continuously change the optical distance by associating the optical distance with the different virtual image distance .
The common optical element has a portion for performing a first optical distance conversion through which a first image light beam for establishing a first virtual image formed at the first position passes, and a second position formed at the second position. The portion where the second optical distance conversion through which the second image light beam for establishing the 2 virtual image passes and the third image light beam passing through the third image light beam for forming the third virtual image formed at the third position are passed. Including the part that performs optical distance conversion,
Head-up display device. In the head-up display device according to claim 1,
The optical system is an optical system in which the image light emitted from the display element is reflected by the front glass so that the virtual image is displayed forward when viewed from the viewpoint of the observer, and the light of the image light. A concave mirror arranged between the display element and the front glass on the road, an optical element arranged between the display element and the concave mirror on the optical path, and the optical element arranged between the display element and the concave mirror on the optical path, and the optical element on the optical path. It includes a cylinder mirror disposed between the display element and the concave mirror after the optical element.
The curved surface of the windshield has a relationship in which the radius of curvature in the horizontal direction is larger than the radius of curvature in the vertical direction.
The cylinder mirror has a shape asymmetrical with respect to the optical axis for correcting distortion caused by the shape of the curved surface of the windshield.
Head-up display device. In the head-up display device according to claim 1,
The optical system is an optical system in which the image light emitted from the display element is reflected by a front glass so that the virtual image is displayed forward when viewed from the viewpoint of the observer, and the light of the image light. It includes a concave mirror arranged between the display element and the front glass on the road and an optical element arranged between the display element and the concave mirror on the optical path.
The concave mirror has a free curved mirror having a shape that is rotationally asymmetric with respect to the optical axis of the image light for correcting the distortion of the virtual image.
Head-up display device. In the head-up display device according to claim 1,
The optical system is an optical system in which the image light emitted from the display element is reflected by a front glass so that the virtual image is displayed forward when viewed from the viewpoint of the observer, and the light of the image light. It includes a concave mirror arranged between the display element and the front glass on the road and an optical element arranged between the display element and the concave mirror on the optical path.
The optical system has a shape that is rotationally asymmetric with respect to the optical axis of the image light for correcting the distortion of the virtual image after the optical element between the display element and the concave mirror on the optical path. Have a free curved lens
Head-up display device. In the head-up display device according to claim 1,
The shape of the common optical element that continuously changes the optical distance is designed by the physical length and the refractive index in the direction of the optical axis of the image light.
Head-up display device. In the head-up display device according to claim 1,
The display element is a head-up display device having a liquid crystal display panel. In the head-up display device according to claim 1,
The display element is a head-up display device having an image projection device and an intermediate image forming unit that forms an image of light from the image projection device. In the head-up display device according to claim 1,
The display element is a head-up display device having a plurality of planar display elements arranged in a direction perpendicular to the optical axis of the image light. In the head-up display device according to claim 8,
A head-up display device in which each of the plurality of planar display elements is arranged at different positions in the direction of the optical axis in order to control the plurality of positions and the magnification of each virtual image. In the head-up display device according to claim 8,
A head-up display device in which each of the plurality of planar display elements is arranged so as to face a predetermined position on the optical axis of the optical system.

Images