TWI729294B - Display device and automobile head-up display system using the same - Google Patents

Abstract

An automobile head-up display system includes a windshield and a display device, wherein the display device comprises a single picture generation unit and an optical imaging module. The picture generation unit is set in the car to generate light of a first image and a second image. The optical imaging module is arranged at a side of the picture generation unit where the light exits to reflect the first image light onto a surface of the windshield via a first light path and reflect the second image light onto a surface of the windshield via a second light path. In this manner, a first virtual image and a second virtual image are generated, wherein the distance of the first light path is smaller than the distance of the second light path. In the automobile head-up display system of the invention, the single picture generation unit can be utilized to generate a plurality of virtual images with different distances to provide the driver abundant driving information.

Description

Display device and head-up display system for vehicle

The invention relates to a display device and a head-up display system for a vehicle, in particular to a display device and a head-up display system for a vehicle that use a single image source module to generate multiple virtual images at different distances.

When driving a car, the driver looking down at the dashboard or other consumer electronic products will affect his observation of road conditions and cause safety hazards. Therefore, transferring the driving information on the dashboard to the head-up display (HUD) has become an important means to improve driving safety.

With the development of HUD, the functions attached to it become more and more abundant. At present, new application requirements such as augmented reality HUD (AR-HUD) have emerged. These new types of HUD require more than one virtual image surface. That is, multiple virtual image planes are required. In this way, information such as navigation and maps can be displayed on the virtual image surface in the distance, and information such as vehicle speed and fuel level can be displayed on the virtual image surface in the vicinity. As shown in Figure 1, Figure 1 shows a schematic diagram of a HUD with a plurality of virtual image planes, which has a virtual image VI_1 at a distance of VI_P1 from the driver 1 and a virtual image VI_2 at a distance of VI_P2 from the driver 1. In the prior art, in order to realize the above-mentioned HUD with multiple virtual image planes, the following two methods are often used: (1) Two image source modules and two sets of projection optical systems, for example, a set of images is installed under the dashboard Source module plus projection optical system, install another set of image source plus projection optics on the top of the cockpit System, so that two sets of systems respectively produce two virtual images with different distances. Or (2) Two image source modules and a set of projection optical systems, for example, as shown in Figure 1, two image sources are installed under the dashboard, namely image source 2, image source 3 and a set of projection optical system 4. The two image sources 2 and 3 use different object distances O1 and O2 relative to the projection optical system 4 to generate virtual images at different distances. However, in the prior art, in order to generate multiple virtual images at different distances, multiple image sources must be used, which not only increases the system cost, but also increases the difficulty of driving, installation, and debugging.

In view of this, how to improve the above problems is the focus of the technology disclosed in the present invention.

The present invention provides a head-up display system for a vehicle that uses a single image source to generate at least two virtual images at different distances to provide a driver with multiple driving information and reduce the assembly and production costs of the head-up display system for the vehicle.

A head-up display system for a vehicle according to an embodiment of the present invention includes a windshield and a display device. The windshield is connected to a body of a vehicle and has a surface that reflects light. The display device includes an image source module and an optical imaging module. The image source module is arranged in the vehicle body, and the image source generates a first image light and a second image light. The optical imaging module is disposed on a light exit side of the image source module, and the optical imaging module includes at least one flat mirror and at least one first curved mirror for reflecting the first image light to the surface of the windshield through a first optical path and reflecting The second image light passes through a second light path to the surface of the windshield to generate a first virtual image and a second virtual image respectively, wherein the distance of the first light path is smaller than the distance of the second light path.

A display device according to another embodiment of the present invention includes an image source module and an optical imaging module. The image source module is arranged in a vehicle body of a vehicle for generating a first image light and a second image light. The optical imaging module is arranged on a light-emitting side of the image source module, and the optical imaging module includes at least A flat mirror and at least one first curved mirror are used to reflect the first image light to the surface of the windshield through a first light path and to reflect the second image light to the surface of the windshield through a second light path to respectively generate a first virtual image and A second virtual image, in which the distance of the first optical path is smaller than the distance of the second optical path.

The following detailed descriptions are provided with specific embodiments in conjunction with the accompanying drawings to make it easier to understand the purpose, technical content, characteristics and effects of the present invention.

1: Driver

2,3: Image source

4: Projection optical system

VI_1, VI_2: virtual image

VI_P1, VI_P2: virtual image distance

O1, O2: Object distance

10: Head-up display system for vehicles

11: Windshield

111: Surface

12: display device

121: Image source module

1211: The first display area

1212: second display area

1213: unused area

122: Optical imaging module

1222, 1222a, 1222b, 1222c: flat mirror

1224, 1225: curved mirror

1226: lens

13: Vehicle

131: Car body

F: Focus

P1: First light path

P2: Second light path

RVI1: The first relay virtual image

RVI2: Second relay virtual image

RVI3,RVI3’: The third relay virtual image

VI1: The first virtual image

VI2: Second virtual image

Figure 1 is a schematic diagram showing a conventional head-up display system for a car.

Fig. 2 is a schematic diagram showing a display device and a head-up display system for a vehicle according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a schematic diagram of an image source module according to an embodiment of the present invention.

4 is a schematic diagram showing a display device and a head-up display system for a vehicle according to another embodiment of the present invention.

FIG. 5 is a schematic diagram showing a display device and a head-up display system for a vehicle according to another embodiment of the present invention.

Fig. 6 is a schematic diagram showing a display device and a head-up display system for a vehicle according to another embodiment of the present invention.

FIG. 7 is a schematic diagram showing a schematic diagram of FOV definition according to an embodiment of the present invention.

8a and 8b are schematic diagrams respectively showing the light path schematic diagram of the first display area and the light path schematic diagram of the second display area of the display device and the head-up display system for a vehicle according to an embodiment of the present invention.

Figures 9a and 9b are schematic diagrams showing a grid image imaging simulation diagram of the first display area and a grid image imaging simulation diagram of the second display area according to an embodiment of the present invention.

10a and 10b are schematic diagrams showing the point cut-off frequency diagram of each field of view in the first display area and the point cut-off frequency diagram of each field of view in the second display area according to an embodiment of the present invention.

Hereinafter, each embodiment of the present invention will be described in detail, and the drawings will be used as an example. In addition to these detailed descriptions, the present invention can also be widely implemented in other embodiments, and easy substitutions, modifications, and equivalent changes of any of the embodiments are included in the scope of the present invention, and the scope of the patent application is quasi. In the description of the specification, in order to enable the reader to have a more complete understanding of the present invention, many specific details are provided; however, the present invention may still be implemented under the premise of omitting some or all of the specific details. In addition, well-known steps or elements are not described in details to avoid unnecessary limitation of the present invention. The same or similar elements in the drawings will be represented by the same or similar symbols. It should be noted that the drawings are for illustrative purposes only, and do not represent the actual size or quantity of the components. Some details may not be completely drawn in order to keep the drawings concise.

Please refer to FIG. 2 first, which is a schematic diagram of a display device and a head-up display system for a vehicle according to an embodiment of the present invention. As shown in the figure, the head-up display system 10 for a vehicle of the present invention includes a windshield 11 and a display device 12. The windshield 11 is connected to a body 131 of a vehicle 13 and has a surface 111. The display device 12 includes an image source module 121 and an optical imaging module 122. The image source module 121 is disposed in the vehicle body 131, and the image source module 121 generates a first image light (not shown in the figure) and a second image light (not shown in the figure). The optical imaging module 122 is disposed on a light emitting side of the image source module 121, and the optical imaging module 122 includes at least one flat mirror 1222 and at least one first curved mirror 1224 for reflecting the first image light through a first optical path P1 To the surface 111 of the windshield 11 and reflect the second image light through a second optical path P2 to the surface 111 of the windshield 11, a first virtual image VI1 and a second virtual image VI2 are respectively generated, wherein the distance of the first optical path P1 is smaller than that of the second The distance of the optical path P2. In one embodiment, the first image light passes through at least one first The curved mirror 1224 is reflected to the surface 111 of the windshield 11, and the second image light is reflected to the surface 111 of the windshield 11 through at least one flat mirror 1222 and at least one first curved mirror 1224.

In addition, in one embodiment, the image source module 121 includes, but is not limited to, a liquid crystal display module, a digital light processing module, a liquid crystal on silicon display module, and a laser display module. In one embodiment, referring to FIG. 3, the image source module 121 includes an image panel, which includes a first display area 1211 and a second display area 1212, and the first display area 1211 and the second display area 1212 are respectively The first image light and the second image light are generated. In one embodiment, the image source module 121 is a single image panel. In one embodiment, in order to avoid light path interference, a small area of the image panel, such as 1213, does not participate in the final imaging, but this unused area can be set differently according to different mechanism designs. In still another embodiment, the image panel may further include a third display area (not shown in the figure) for generating a third image light, and so on, the image panel may include two or more display areas. Produce two or more image lights. The present invention uses a single image source module to divide and utilize the display area of the image source to form a plurality of display areas that are logically independently used but are physically integrated, as shown in FIG. 3. Figure 3 illustrates the principle of segmentation and utilization with two display areas. The first display area 1211 and the second display area 1212 in FIG. 3 correspond to two virtual images with different final distances. And the division method is not limited to rectangular division, it can be division of any geometric shape, and to adjust the system structure space, the image panel may have some unused areas, but it is not a necessary configuration.

In the present invention, in order to arrange a plurality of display areas to different positions in space to form different object distances, the present invention uses optical imaging modules such as plane mirrors, curved mirrors, lenses, etc., to image at least one display area into a space different from the original image source space. Other locations; other display areas are maintained at their original positions in space, or are imaged to other locations in space by another optical relay system (optical imaging module) (here, other positions refer to the corresponding display area different from the aforementioned first relay system) The imaged position). For further explanation, the embodiments of FIGS. 3 and 4 are used. FIG. 4 is a schematic diagram of a display device according to another embodiment of the present invention based on the embodiment of FIG. 2. As shown in the embodiment shown in FIGS. 3 and 4, the image source module 121 is divided into two display areas (a first display area 1211 and a second display area 1212, with an unused area 1213 between them). A display area 1211 issued The light ray directly hits the first curved mirror 1224, and then is reflected toward the windshield 11 to form a first virtual image (the first virtual image VI1 in FIG. 2). The light emitted from the second display area 1212 is directed to the plane mirror 1222a, and through the plane mirror imaging principle, a first relay virtual image RVI1 is generated; the first relay virtual image RVI1 is reflected and imaged by the plane mirror 1222b to generate a second relay virtual image RVI2; The second relay virtual image RVI2 is reflected and imaged by the plane mirror 1222c, and a third relay virtual image RVI3 is generated. In this way, the second display area 1212 is transferred to a position different from the original image source, that is, the third relay virtual image RVI3, by the optical relay system composed of plane mirrors 1222a, 1222b, and 1222c. The third relay virtual image RVI3 is then projected optically by the curved mirror 1224 and the windshield 11 to generate a second virtual image (the second virtual image VI2 in FIG. 2). Since the first display area 1211 and the third relay virtual image RVI3 (the third relay virtual image RVI3 that is the transfer image of the second display area 1212) that are not affected by the conversion system are different from the curved mirror 1224, they are in a reasonable design Afterwards, they are both located within the focal point F of the curved mirror. The first virtual image VI1 (as shown in Figure 2) and the second virtual image VI2 (as shown in Figure 2) have different virtual image distances relative to the driver 1. In one embodiment , The distance from the imaging position of the second virtual image VI2 (as shown in FIG. 2) to a virtual image of a driver 1 is greater than 2 meters. The present invention utilizes an optical imaging system to transfer at least one display area to other positions in space, so that a plurality of display areas have different object distances to the main projection optical system (ie, the first curved mirror 1224 in this embodiment).

The embodiment of FIG. 4 is illustrated by taking an optical imaging module composed of three flat mirrors as an example. In yet another embodiment, please refer to FIG. 5, which is a schematic diagram of a display device according to another embodiment of the present invention based on the embodiment in FIG. 2. The only difference from FIG. 4 is that the optical imaging module 122 further includes a second curved mirror 1225, which is disposed on the second optical path P2 between the image source module 121 and the at least one first curved mirror 1224, that is, That is, compared with the embodiment in FIG. 4, the flat mirror 1222c in the optical imaging module 122 is replaced with a curved mirror 1225. Because of the non-zero refractive power introduced by the curved mirror 1225, as shown in FIG. 5, the third The size of the subsequent virtual image RVI3' is larger than the corresponding second display area 1212 (the size of the third relay virtual image RVI3 in FIG. 4 is equal to the second display area 1212). Or, in an embodiment, as shown in FIG. 6, the optical imaging module 122 includes flat mirrors 1222a, 1222b, curved mirrors 1225, and lenses 1226. That is, in the embodiment of FIG. On the basis of this, a lens 1226 is added to correct the aberration of the curved mirror 1225 magnified and imaged. The lens 1226 is arranged on the second optical path P2 between the image source module and the curved mirror 1225. This is general knowledge in the field of optical design and will not be repeated here. Therefore, it is understandable that the design of the optical imaging system can be adjusted by those skilled in the art as required.

According to the above description of the present invention, a single image source is converted into a plurality of objects with different object distances to the main projection optical system after the action of the optical transfer system. According to the principle of Gaussian optics, virtual images with different distances will be generated. In addition, in order to ensure that the generated virtual image has practical image quality, the main projection system also needs to go through an optimized optical design to ensure that various specifications meet the imaging requirements of the HUD. Generally speaking, imaging quality specifications include the modulation transfer function (MTF) value at the cut-off frequency (cut-off frequency) determined by the pixel size of the image source at each field of view (field of view, FOV). , Distortion rate, astigmatism, binocular parallax, etc. The optimized optical design and evaluation described here are general knowledge in the field and will not be repeated here.

To illustrate the automotive head-up display using a single image source module and having multiple virtual image planes proposed by the present invention, a specific embodiment is provided here. The image source module 121 is a single liquid-crystal display (LCD) with a size of 57mm×34mm (2.6 inches diagonal), which is divided into two parts. The dividing method is shown in FIG. 3. The size of a display area 1211 is 57 mm×14 mm, the size of the second display area 1212 is 57 mm×16 mm, and there is an unused area 1213 with an area of 57 mm×4 mm between the two display areas. The schematic diagram of the display device 12 is the same as that shown in FIG. 4, the first display area 1211 does not correspond to the revolving system, and the revolving system of the second display area 1212 includes three plane mirrors (plane mirrors 1222a, 1222b, 1222c).

The windshield 11 used in this embodiment has a curvature of 7500 mm in a direction perpendicular to the ground and a curvature of 3000 mm in a direction parallel to the ground. If the coordinate system is established based on the line of sight of the driver 1 (with a viewing angle of 5° relative to the ground), as shown in Figure 7, the FOV of the first virtual image VI1 generated by the first display area 1211 is -2.5°~2.5° (x direction) And -3.5°~-1.5°(y direction), the distance to the virtual image of the driver 1 is 2.5m. The FOV of the second virtual image VI2 generated by the second display area 1212 is -5°~5° (x direction) and -0.5°~2.5° (y direction), and the distance from the virtual image of the driver 1 is 9m; both eyes can watch at the same time The range to the first virtual image VI1 and the second virtual image VI2 is 120 mm (x direction) and 60 mm (y direction), that is, the eyebox range. The surface parameter of the curved mirror 1224 of the optical imaging module 122 is described by equation (1), which is a hyperbolic equation including 6th-order aspheric coefficients, specifically as described in Table 1 for the curved mirror surface parameters of the optical imaging module 122. The optical path diagrams of the central field of view points of the two display areas including the eyes of the driver are shown in Figure 8a and Figure 8b. Among them, the equation (1) that defines the curved shape of the curved mirror 1224 of the optical imaging module 122 is as follows:

In terms of imaging quality, this embodiment illustrates the two key specifications of grid image imaging simulation of the two display areas and MTF within the cut-off frequency. As shown in FIG. 9a and FIG. 9b, it can be seen that the first display area 1211 and the second display area The distortion rate of the virtual image corresponding to 1212 is very slight, less than 5%; as shown in Figure 10a and Figure 10b, the cutoff frequency of the first display area 1211 and the second display area 1212 is determined by the LCD pixel size (8 cycles/mm) The MTF values inside are all greater than 0.5, which is a diffraction limited system. According to the general knowledge of visual imaging optics, this system has clear imaging.

According to the above, the display device and the head-up display system for a vehicle of the present invention, wherein the image source module of the display device can provide at least two image sources to form a plurality of display areas that are logically independent and physically integrated; display; The optical imaging module of the device at least includes at least one flat mirror and at least one curved mirror, which can flexibly perform different rotation configurations according to different image source modules to clearly image at least two virtual images.

In summary, the display device and the head-up display system for a vehicle of the present invention use a single image source to generate at least two virtual images at different distances to provide the driver with multiple driving information and reduce the assembly and production cost of the head-up display system for the vehicle.

The above-mentioned embodiments are only to illustrate the technical ideas and features of the present invention, and their purpose is to enable those who are familiar with the art to understand the content of the present invention and implement them accordingly. When the scope of the patent of the present invention cannot be limited by this, That is, all equal changes or modifications made in accordance with the spirit of the present invention should still be covered by the patent scope of the present invention.

1: Driver

10: Head-up display system for vehicles

11: Windshield

111: Surface

12: display device

121: Image source module

1211: The first display area

1212: second display area

1213: unused area

122: Optical imaging module

1222: flat mirror

1224: curved mirror

13: Vehicle

131: Car body

P1: First light path

P2: Second light path

VI1: The first virtual image

VI2: Second virtual image

Claims (10)

A head-up display system for a vehicle, comprising: a windshield connected to a body of a vehicle and having a surface that reflects light; and a display device comprising: an image source module, which is arranged in the vehicle In the body, as a single image source, it is used to generate a first image light and a second image light; and an optical imaging module is arranged on a light emitting side of the image source module, and the optical imaging module includes at least one plane mirror and At least one first curved mirror for reflecting the first image light to the surface of the windshield through a first light path and reflecting the second image light to the surface of the windshield through a second light path to respectively generate a first A virtual image and a second virtual image, wherein the distance of the first optical path is smaller than the distance of the second optical path; wherein the image source module is located in a focal point of the at least one first curved mirror. The head-up display system for a vehicle according to claim 1, wherein the image source module includes a liquid crystal display module, a digital light processing module, a liquid crystal on silicon display module, and a laser display module. The head-up display system for a vehicle according to claim 1, wherein the image source module includes an image panel including a first display area and a second display area, and the first display area and the second display area The first image light and the second image light are respectively generated. The head-up display system for a vehicle according to claim 1, wherein the first image light is reflected to the windshield through the at least one first curved mirror, and the second image light is passed through the at least one flat mirror and the at least one first curved surface The mirror reflects to the windshield. The head-up display system for a vehicle according to claim 1, wherein the optical imaging module further includes a second curved mirror or the optical imaging module further includes a second curved mirror and a lens, which are disposed on the image source mold Group to the second optical path between the at least one first curved mirror. A display device includes: an image source module, which is arranged in a vehicle body of a vehicle, as a single image source for generating a first image light and a second image light; and an optical imaging module, which is arranged in One light-emitting side of the image source module, the optical imaging module includes at least one flat mirror and at least one first curved mirror, for reflecting the first image light to the surface of the windshield via a first light path and reflecting the first Two image lights pass through a second light path to the surface of the windshield to generate a first virtual image and a second virtual image respectively, wherein the distance of the first light path is smaller than the distance of the second light path; wherein, the image source module Is located in a focal point of the at least one first curved mirror. The display device according to claim 6, wherein the image source module includes a liquid crystal display module, a digital light processing module, a liquid crystal on silicon display module, and a laser display module. The display device according to claim 6, wherein the image source module includes an image panel including a first display area and a second display area, and the first display area and the second display area respectively generate the The first image light and the second image light. The display device according to claim 6, wherein the first image light is reflected to the windshield through the at least one first curved mirror, and the second image light is reflected to the windshield through the at least one flat mirror and the at least one first curved mirror The windshield. The display device according to claim 6, wherein the optical imaging module further includes a second curved mirror or the optical imaging module further includes a second curved mirror and a lens, which are arranged between the image source module and the The second optical path between at least one first curved mirror.

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