JP6580328B2 - Head-up display device for vehicle - Google Patents

Description

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

  As a background art in this technical field, there is JP 2009-150947 A (Patent Document 1). This publication discloses a vehicle head-up display device including a light source, a scanning unit that scans light from the light source two-dimensionally, a screen that forms an image of the scanning light, and a projection unit that projects an image on the screen. It is provided with a movable mechanism that makes the position of the screen variable.

JP 2009-150947 A

In the invention described in Patent Document 1, the problem is that the virtual image displayed by the head-up display device has a constant distance from the viewpoint of the vehicle occupant to the virtual image regardless of the vertical position of the virtual image. is there.
Therefore, it seems as if a virtual image was projected on a plane perpendicular to the passenger's line of sight, as if the virtual screen was floating in the air, and the scenery in front of the passenger was hidden by the virtual image There is a problem of feeling. Furthermore, since the front landscape and the virtual image are visually recognized in a separated state, there is a problem that the passenger has a burden of focusing when viewing the virtual image from the state of viewing the landscape, and the comfort is inferior.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a vehicle head-up display device that can reduce a burden on a passenger.

In order to achieve the above object, the present invention projects image light in a vehicle head-up display device for projecting image light onto a projection surface installed in a vehicle and displaying a virtual image based on the image light. comprising a device, and a reflecting mirror for reflecting projected image light on the projection surface from said projection device, wherein the reflecting mirror is gradually curvature toward the other end from the one end portion is formed to vary The reflection mirror reflects projection image light reflected from an area having a large curvature upwardly from the projection surface .

It is a schematic structure figure of the head up display device for vehicles concerning this embodiment. It is a block diagram which shows the control structure of a head-up display apparatus. (A) is explanatory drawing which shows the relationship between the image before image correction, and a virtual image, (b) is explanatory drawing which shows the relationship between the image after image correction, and a virtual image. It is a schematic block diagram which shows the modification of a projection apparatus. It is explanatory drawing which shows the example of the virtual image by this embodiment. It is explanatory drawing which shows the example of the virtual image by a conventional apparatus. It is a schematic block diagram which shows the modification of this embodiment.

As shown in FIG. 1, the vehicle head-up display device 1 is provided at a predetermined position below the front windshield 2 in the vehicle, and the head-up display device 1 includes a projection device 10. In addition, the head-up display device 1 includes a reflection mirror 11 that reflects image light projected from the projection device 10. Further, the virtual image 15 is clearly visible by attaching a seal having a half mirror function to a predetermined portion of the front windshield 2 or by performing an appropriate process so as to have a half mirror function. The projection surface 12 that can be formed is formed.
The head-up display device 1 projects the image light projected from the projection device 10 onto the projection surface 12 of the front windshield 2 via the reflection mirror 11, thereby forming a virtual image in front of the projection surface 12. 15 is displayed.

In the present embodiment, the cross-sectional shape on the side surface of the reflection mirror 11 is a free-form surface shape in which the curvature gradually changes from one end side to the other end side of the reflection mirror 11. The curved shape of the reflecting mirror 11 is, for example, formed so as to have a Euler spiral shape (also called a Cornu spiral or a clothoid). However, the curved surface shape of the reflection mirror 11 is not limited to this, and any shape can be used as long as the curvature gradually changes from one end side to the other end side of the reflection mirror 11. Also good.
Moreover, the cross-sectional shape in the plane of the reflective mirror 11 is formed in spherical shape or aspherical shape.
Further, the outer peripheral edge portion of the reflection mirror 11 is formed so as to have a small curvature in order to correct distortion of the projected image light. When projecting image light, if the image light can be corrected and projected in consideration of image distortion at the outer peripheral portion of the reflecting mirror 11, the curvature of the outer peripheral portion of the reflecting mirror 11 is not necessarily required. It is not necessary to reduce the size.

Here, when image light is projected from the projection device 10 onto the reflection mirror 11 to display the virtual image 15, the following relational expression holds.
1 / a + 1 / b = 1 / f
Here, a is the distance from the projection device 10 to the reflecting mirror 11, b is the distance from the reflecting mirror 11 to the position where the virtual image 15 is formed, and f is the focal length (1/2 of the curvature) of the reflecting mirror 11. is there.
Moreover, if the curvature of the reflective mirror 11 becomes large, the focal distance of the reflective mirror 11 will become short, and the magnitude | size of the virtual image 15 will become large, so that a focal distance is short.
For these reasons, the image light projected from the projection device 10 to the portion where the curvature of the reflection mirror 11 is large has a short focal length, and therefore when reflected on the projection surface 12, the distance from the projection surface 12 is long. The virtual image 15 is displayed. On the other hand, the image light projected from the projection device 10 onto the portion where the curvature of the reflection mirror 11 is small has a long focal length. Therefore, when the image light is reflected on the projection surface 12, the virtual image 15 is at a position where the distance from the projection surface 12 is short. Will be displayed.

Further, the projection position of the image light from the projection device 10 and the reflection position by the reflection mirror 11 correspond one-to-one. That is, the image light projected from the projection device 10 is configured to be projected over the entire range in which the curvature of the reflection mirror 11 changes.
With this configuration, the curvature of the reflection mirror 11 differs depending on the position at which the image light is projected from the projection device 10, and the virtual image 15 reflected by the reflection mirror 11 and projected onto the projection surface 12 is displayed. The display position and size of will change.
Therefore, by controlling the projection position of the image light from the projection device 10, the projection position on the reflection mirror 11 can be changed, and thereby the display position of the virtual image 15 on the projection surface 12 can be changed. It becomes. In this way, by arbitrarily changing the projection position of the image light from the projection device 10, the display position on the projection surface 12 can be changed, and the display position of the virtual image 15 formed on the projection surface 12 is increased far away. Or it becomes possible to make it display near small.

Further, the projection device 10 is preferably installed at a position closer to the focal length of the reflection mirror 11. This is because if the projection device 10 is installed at a position farther than the focal length of the reflection mirror 11, the image projected from the projection device 10 is inverted upside down.
And since the reflective mirror 11 changes a focal position, ie, a curvature with a location, it is preferable to install the projection apparatus 10 in the position nearer than the shortest focal position. However, even when the projection device 10 is installed at a position farther than the focal length of the reflection mirror 11, there is no problem because the image projected from the projection device 10 may be projected in an upside down state.

In general, the objects that the passenger 16 of the vehicle visually recognizes from the upper part of the front windshield 2 are a building, a mountain, a sky, a distant road, and the like that are located far from the eyes of the passenger 16. For this reason, the focus of the eyes of the occupant 16 when viewing the scenery outside the vehicle in the upper part of the front windshield 2 is highly likely to be adjusted to the focus when viewing a distant object.
On the other hand, the objects to be visually recognized from the lower part of the front windshield 2 are a hood of a vehicle located in the vicinity from the eyes of the passenger 16, a rear part of another vehicle traveling in front of the vehicle, a nearby road, and the like. Therefore, the focus of the eyes of the occupant 16 when viewing the scenery outside the vehicle at the lower part of the front windshield 2 is highly likely to be adjusted to the focus when viewing an object located in the vicinity.

Therefore, in the present embodiment, the reflection mirror 11 is arranged so that a portion with a large curvature is reflected above the projection surface 12 and a portion with a small curvature on the reflection mirror 11 is reflected below the projection surface 12. . By arranging in this way, the virtual image 15 displayed large and far away is displayed above the projection surface 12, and the virtual image 15 displayed small and close is displayed below the projection surface 12.
Accordingly, the vehicle occupant 16 visually recognizes the virtual image 15 displayed far in front of the projection surface 12 in a state where the object located far away is visually recognized, so that the eyes are focused. Load is reduced and comfort is improved. Further, since the virtual image 15 displayed near the front under the projection surface 12 is visually recognized in the state where the object located in the vicinity is visually recognized, similarly, the load for focusing the eyes is reduced. Comfort is improved.
The arrangement of the reflecting mirror 11 is not limited to this, and the virtual image 15 displayed large and far away is displayed below the projection surface 12, and the virtual image 15 displayed small and close is displayed on the projection surface. It may be displayed above 12.

Next, the control configuration in the present embodiment will be described with reference to FIG.
The projection device 10 of the vehicle head-up display device 1 includes a light source 20 such as a lamp or LED, an image forming unit 21 that forms an image to be displayed as a virtual image 15, and focus adjustment of image light output from the image forming unit 21. And a projection optical system 22 that performs various adjustments such as enlargement or reduction of the image and projects it as image light.
As the image forming unit 21, for example, a light transmission type liquid crystal display device, a beam light from the light source 20 is used as a MEMS (Micro Electro Mechanical Systems) mirror, a galvano mirror, a polygon mirror, or a combination of these scanning means. For example, a two-dimensional scanning display device that forms an image by scanning in a two-dimensional manner using a conventional scanning unit is used.

The control unit 23 includes a CPU, a control program executed by the CPU, a ROM that stores data related to the control program, a RAM that functions as a working area, other peripheral circuits, and peripheral devices. Central control of each part.
The function of each functional block included in the control unit 23 is realized by cooperation of hardware and software, such as a CPU reading and executing a program.

The navigation management unit 24 is connected to an in-vehicle navigation device 25 mounted on the vehicle, and appropriately acquires information related to navigation from the in-vehicle navigation device 25. And the navigation management part 24 outputs the information regarding suitable navigation to the control part 23 at an appropriate timing, while the vehicle-mounted navigation apparatus 25 is navigating.
For example, when the navigation management unit 24 detects that the vehicle has approached a predetermined distance from the intersection to be turned right or left, the navigation management unit 24 notifies the control unit 23 of such information and information on the right or left turn direction. Output. Further, for example, when the navigation management unit 24 detects that the vehicle has approached a predetermined distance from the destination, the navigation management unit 24 outputs information to that effect to the control unit 23. In addition, the timing at which the navigation management unit 24 outputs information related to navigation and the information to be output are determined in advance.

Further, the control unit 23 includes a display control unit 26 that controls an image to be sent to the projection device 10 and an image correction unit 27 that corrects image data to be sent to the projection device 10.
The display control unit 26 generates image information in the projection device 10 based on the navigation information sent from the navigation management unit 24. The display control unit 26 also generates display control information such as a projection position of image information with respect to the projection surface 12.

  Further, the image correction unit 27 corrects the image information sent to the projection device 10 based on the image information and display control information sent from the display control unit 26. The image correction unit 27 performs various corrections such as image information enlargement / reduction correction and projection image distortion correction.

Further, in the present embodiment, the curvature of the reflection mirror 11 is formed so as to continuously change, and the magnification of the displayed image differs depending on the curvature of the reflection mirror 11, so that FIG. As shown, if the image is displayed as it is based on the image information, the shape of the image becomes trapezoidal. Therefore, in this embodiment, as shown in FIG. 3B, the image correction unit 27 corrects the image to be displayed into an inverted trapezoidal image so that a normal image is obtained when the image to be displayed becomes a trapezoid. It is preferable to send it to the projection device 10.
With this configuration, it is possible to display an image appropriately even when the shape changes to a trapezoid.
Note that since the trapezoidal image changes depending on the curvature of the reflection mirror 11, it is preferable to change the correction amount according to the projection position of the image light projected on the reflection mirror 11.

  Further, the projection device 10 may project image light on an arbitrary position of the reflection mirror 11, for example. Further, the projection device 10 may be divided into a plurality of areas, and image light may be projected from each of these areas. For example, the projection device 10 is divided into a region that projects the large curvature region of the reflection mirror 11, a region that projects the medium curvature region, and a region that projects the small curvature region. Image light is projected from each region to a corresponding region of the corresponding reflecting mirror 11. As a result, it is possible to perform display for each region according to the curvature of the reflecting mirror 11, that is, the display position of the virtual image 15. Further, as shown in FIG. 4, the projection device 10 is projected onto a large curvature region of the reflection mirror 11, the projection device 10 b is projected onto a medium curvature region, and the projection device 10 is projected onto a small curvature region. You may make it comprise with the three apparatuses 10a, 10b, and 10c by 10c.

Next, the operation of the head-up display device 1 in this embodiment will be described.
In the present embodiment, the navigation management unit 24 connected to the vehicle-mounted navigation device 25 mounted on the vehicle acquires information related to navigation, and the navigation management unit 24 is appropriate while the vehicle-mounted navigation device 25 is navigating. At appropriate timing, information related to appropriate navigation is output to the control unit 23. And the control part 23 produces | generates the image information and display control information in the projection apparatus 10 by the display control part 26 based on required navigation information, and based on the image information and display control information sent from the display control part 26 The image correction unit 27 performs various corrections such as enlargement / reduction correction of image information of image information to be sent to the projection apparatus 10 and distortion correction of the projected image.

Thereafter, by operating the projection apparatus 10 based on the image information corrected by the image correction unit 27, an image is formed by the image forming unit 21, and the focal point is adjusted by the projection optical system 22 to adjust the reflection mirror. 11 is projected.
The image light projected onto the reflection mirror 11 is reflected after being enlarged or reduced by a curvature corresponding to the projection position and projected onto the projection surface 12. Thereby, the passenger 16 of the vehicle can visually recognize the image projected on the half mirror as the virtual image 15.

Next, a display example by the head-up display device 1 in the present embodiment will be described.
FIG. 5 is an explanatory view showing a display example by the head-up display device 1 in this embodiment, and FIG. 6 is an explanatory view showing a display example by the conventional head-up display device.
As shown in FIG. 5, a display area 30 that functions as the projection surface 12 is formed on the front windshield 2, and a predetermined virtual image 15 is displayed on the display area 30. FIG. 5 shows an example in which the vehicle is traveling on a road where an intersection with a traffic light exists ahead of the vehicle.
According to this example, by projecting image light from the projection device 10 onto a region with a small curvature of the reflection mirror 11, for example, a virtual image 15 a of a speed limit display of the road is displayed below the display region 30. Further, by projecting image light from the projection device 10 to a region with a medium curvature from a region with a small curvature of the reflection mirror 11, a lane display virtual image 15b is displayed from the lower side of the display region 30 to the intermediate position. By projecting image light from the projection device 10 onto a region with a large curvature of the reflecting mirror 11, a virtual image 15c of a travel instruction display that prompts a right turn at an intersection is displayed above the display region 30.

On the other hand, as shown in FIG. 6, in the display by the conventional head-up display device, the perspective of the virtual image 15 displayed in the display area 30 becomes uniform, and the vehicle occupant 16 is an object located far away. When viewing the display area 30 while viewing the image, it is necessary to focus the eyes on the display area 30. Therefore, the load on the passenger 16 may increase.
On the other hand, in this embodiment, perspective virtual images 15a, 15b, and 15c can be displayed from the lower side to the upper side of the display area 30. That is, in the state where the passenger 16 is viewing far away, the virtual images 15a, 15b, and 15c to be viewed are displayed far away above the display area 30, and the passenger 16 is viewing the vicinity. The virtual images 15a, 15b, and 15c to be visually recognized can be displayed below the display area 30 and in the vicinity thereof. Therefore, it becomes possible to reduce the load for the passenger 16 to focus the eyes.

  The display example is merely an example, and any other information may be displayed as long as the information is acquired by the in-vehicle navigation device 25. For example, display the distance to the intersection to be turned right or left, display the intersection information such as the intersection name and the left turn of the intersection, the pseudo signal display at the intersection, the distance display to the destination, etc. Can be displayed arbitrarily.

  As described above, in the vehicle head-up display device 1 according to the present embodiment, the projection device 10 that projects image light and the reflection mirror 11 that reflects the image light projected from the projection device 10 to the projection surface 12. The reflection mirror 11 is formed so that its curvature changes, and therefore, the display of the virtual image 15 projected and displayed on the projection surface 12 according to the position where the image light is projected from the projection device 10 The position and the size can be changed, and accordingly, it is possible to perform appropriate display such that the display position of the virtual image 15 formed on the projection surface 12 is displayed far larger or smaller near. As a result, the virtual image 15 displayed on the projection surface 12 can be melted into the surrounding scenery, the load for the passenger 16 to focus the eyes can be reduced, and comfort can be improved. .

Further, according to the present embodiment, the curvature of the reflecting mirror 11 gradually changes from one end to the other end.
According to this configuration, the display position and size of the virtual image 15 projected and displayed on the projection surface 12 can be gradually changed depending on the position at which the image light is projected from the projection device 10. Appropriate display can be performed such that the display position of the virtual image 15 formed on the surface 12 is displayed far larger or smaller near.

Further, according to the present embodiment, the projection device 10 projects the image light over the entire range in which the curvature of the reflection mirror 11 changes.
According to this configuration, the display position and size of the virtual image 15 projected and displayed on the projection surface 12 can be changed depending on the position at which the image light is projected from the projection device 10.

Moreover, according to this embodiment, the reflective mirror 11 reflects the projection image light reflected from the area | region with a large curvature above a projection surface.
According to this configuration, when reflected above the projection surface 12, the virtual image 15 can be displayed at a position where the distance from the projection surface 12 is long.

Further, according to the present embodiment, the reflection mirror 11 is formed by a half mirror, and the reflection mirror 11 functions as a projection surface.
According to this configuration, since the reflection mirror 11 also serves as the projection surface 12, the number of parts can be reduced.

Further, according to the present embodiment, the projection device 10 is disposed at a position shorter than the focal length of the reflection mirror 11.
According to this configuration, the image projected from the projection device 10 can be displayed upright.

Further, according to the present embodiment, the image correction unit 27 that corrects an image projected from the projection device 10 is provided.
According to this configuration, an image having a correct shape can be displayed.

Further, according to the present embodiment, the image correction unit 27 corrects the keystone of the image projected from the projection device 10.
According to this configuration, it is possible to correctly display an image that has changed to a trapezoidal shape.

In addition, in the said embodiment, although it was set as the structure which projects the image of the projection apparatus 10 on the projection surface 12 via the reflective mirror 11, it is not limited to this.
For example, as shown in FIG. 7, the reflecting mirror 11 is provided with a function as a half mirror, and the reflecting mirror 11 is installed at a position where it can be seen from the passenger 16, and the reflecting mirror 11 is used as the projection surface 12. May be.
According to such a configuration, since the image light is directly projected from the projection device 10 onto the reflection mirror 11 that is the projection surface 12, it is possible to obtain the same effect as in the above-described embodiment and to install one reflection mirror 11. Therefore, the number of parts and the installation space can be reduced.

  Moreover, the present invention is not limited to the above-described embodiment, and various modifications can be made along the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Vehicle head-up display apparatus 2 Front windshield 10 Projection apparatus 11 Reflection mirror 12 Projection surface 15 Virtual image 16 Passenger 20 Light source 21 Image formation part 22 Projection optical system 23 Control part 24 Navigation management part 25 In-vehicle navigation apparatus 26 Display control part 27 Image Correction Unit 30 Display Area

Claims (6)

In a vehicle head-up display device that projects image light onto a projection surface installed in a vehicle and displays a virtual image based on the image light,
A projection device that projects image light, and a reflection mirror that reflects the image light projected from the projection device to the projection surface,
The reflection mirror is formed such that the curvature gradually changes from one end to the other end ,
The vehicle head-up display device , wherein the reflection mirror reflects projection image light reflected from an area having a large curvature upwardly from the projection surface .   2. The vehicle head-up display device according to claim 1, wherein the projection device projects image light over an entire range in which a curvature of the reflection mirror changes. The vehicle head-up display device according to claim 1 , wherein the reflection mirror is formed of a half mirror, and the reflection mirror functions as the projection surface . The vehicle head-up display device according to claim 1, wherein the projection device is disposed at a position shorter than the shortest focal length of the reflecting mirrors . The vehicle head-up display device according to claim 1, further comprising an image correction unit that corrects an image projected from the projection device. The vehicle head-up display device according to claim 5, wherein the image correction unit corrects a keystone of an image projected from the projection device.

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