CN110554497A

CN110554497A - Display device and vehicle head-up display system thereof

Info

Publication number: CN110554497A
Application number: CN201810547722.7A
Authority: CN
Inventors: 秦宗; 林世明; 骆光祚
Original assignee: Dongguan Chuangyi Electronic Technology Co Ltd
Current assignee: Dongguan Chuangyi Electronic Technology Co Ltd
Priority date: 2018-05-31
Filing date: 2018-05-31
Publication date: 2019-12-10

Abstract

The invention provides a display device and a vehicle head-up display system thereof. The image source module is arranged in the vehicle body and used 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 used for reflecting first image light to the surface of the windshield through a first light path and reflecting 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, wherein the distance of the first light path is smaller than that of the second light path. The display device and the vehicle head-up display system thereof generate a plurality of virtual images with different distances by using a single image source so as to provide a plurality of driving information for a driver and reduce the assembly and production cost of the vehicle head-up display system.

Description

Display device and vehicle head-up display system thereof

Technical Field

The present invention relates to a display device and a head-up display system for a vehicle, and more particularly, to a display device and a head-up display system for a vehicle, which use a single image source module to generate a plurality of virtual images at different distances.

Background

In the driving process of an automobile, a driver lowers head to watch an instrument board or other consumer electronics products, so that the observation of the instrument board or other consumer electronics products on the road surface condition is influenced, and potential safety hazards are caused. Therefore, transferring the driving information on the dashboard to a head-up display (HUD) becomes an important means for improving driving safety.

With the development of HUDs, the functions added thereto are more and more abundant, and new application requirements such as augmented reality HUDs (AR-HUDs) are generated, and these new HUDs need more than one virtual image plane, i.e. multiple virtual image planes. Thus, information such as navigation and maps can be displayed on the far virtual image plane, and information such as vehicle speed and oil amount can be displayed on the near virtual image plane. As shown in fig. 1, fig. 1 shows a schematic diagram of a HUD having a plurality of virtual image planes, with a virtual image VI _1 at a distance VI _ P1 from driver 1, and a virtual image VI _2 at a distance VI _ P2 from driver 1. However, in the prior art, in order to implement the HUD having a plurality of virtual image planes, the following two methods are adopted: (1) the two image source modules and the two projection optical systems are arranged, for example, one image source module and the projection optical system are arranged below an instrument board, the other image source and the projection optical system are arranged at the top of a cockpit, and the two systems respectively generate two virtual images with different distances. Or (2) two image source modules and one set of projection optical system, for example, as shown in fig. 1, two image sources, i.e., an image source 2, an image source 3, and one set of projection optical system 4, are installed under the dashboard, and the two image sources 2 and 3 generate virtual images at different distances by using object distances O1 and O2 different from the projection optical system 4. However, in the prior art, in order to generate a plurality of virtual images at different distances, a plurality of image sources must be used, which not only increases the system cost, but also increases the difficulty of driving, installing and debugging.

Therefore, how to improve the above-mentioned problems is the technical focus of the present invention.

Disclosure of Invention

The invention provides a vehicle head-up display system which utilizes a single image source to generate at least two virtual images with different distances so as to provide a plurality of driving information for a driver and reduce the assembly and production cost of the vehicle head-up display system.

The vehicle head-up display system of an embodiment of the invention comprises a windshield and a display device. The windshield is connected with a body of a vehicle and has a surface for reflecting light. The display device comprises 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 arranged on a light outlet side of the image source module and comprises at least one plane mirror and at least one first curved mirror, the plane mirror is used for reflecting first image light to the surface of a windshield through a first light path and reflecting second image light to the surface of the windshield through a second light path, a first virtual image and a second virtual image are generated respectively, and the distance between the first light path and the second light path is smaller than that between the first light path and the second light path.

The display device of another embodiment of the invention comprises an image source module and an optical imaging module. The image source module is arranged in a vehicle body of a vehicle and used for generating a first image light and a second image light. The optical imaging module is arranged on a light outlet side of the image source module and comprises at least one plane mirror and at least one first curved mirror, the plane mirror is used for reflecting first image light to the surface of a windshield through a first light path and reflecting second image light to the surface of the windshield through a second light path, a first virtual image and a second virtual image are generated respectively, and the distance between the first light path and the second light path is smaller than that between the first light path and the second light path.

The purpose, technical content, features and effects of the present invention will be more readily understood by the following detailed description of the embodiments taken in conjunction with the accompanying drawings.

Drawings

Fig. 1 is a schematic view illustrating a conventional head-up display system for a vehicle.

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

Fig. 3 is a schematic view illustrating an image source module according to an embodiment of the invention.

Fig. 4 is a schematic view illustrating a display device and a vehicle head-up display system according to another embodiment of the invention.

Fig. 5 is a schematic view illustrating a display device and a vehicle head-up display system according to another embodiment of the invention.

Fig. 6 is a schematic view illustrating a display device and a vehicle head-up display system according to still another embodiment of the invention.

Fig. 7 is a diagram illustrating FOV definition according to an embodiment of the present invention.

fig. 8a and 8b are schematic diagrams respectively illustrating an optical path schematic diagram of a first display area and an optical path schematic diagram of a second display area of a display device and an automotive head-up display system according to an embodiment of the invention.

Fig. 9a and 9b are schematic views 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 invention.

fig. 10a and 10b are schematic diagrams illustrating a point cut-off frequency graph of each field of view of the first display area and a point cut-off frequency graph of each field of view of the second display area according to an embodiment of the invention.

Reference numerals:

1 driver

2,3 image source

4 projection optical system

Virtual image of VI _1 and VI _2

VI _ P1, VI _ P2 virtual image distance

O1, O2 object distance

Head-up display system for 10 vehicles

11 wind shield

111 surface

12 display device

121 image source module

1211 first display area

1212 second display area

1213 unused area

122 optical imaging module

1222,1222a,1222b,1222c plane mirror

1224,1225 curved mirror

1226 lens

13 vehicle

131 vehicle body

F focus

P1 first light path

p2 second light path

RVI1 first relay virtual image

RVI2 second relay virtual image

RVI3, RVI 3' third Relay virtual image

VI1 first virtual image

VI2 second virtual image

Detailed Description

The following detailed description of the embodiments of the invention is provided in connection with the accompanying drawings. Aside from the details given herein, this invention is capable of broad application to other embodiments and that various other substitutions, modifications, and equivalents may be made in the embodiments without departing from the scope of the invention as defined by the appended claims. In the description of the specification, numerous specific details are set forth in order to provide a more thorough understanding of the invention; however, the present invention may be practiced without some or all of these specific details. In other instances, well-known steps or elements have not been described in detail so as not to unnecessarily obscure the present invention. The same or similar elements in the drawings will be denoted by the same or similar symbols. It is noted that the drawings are for illustrative purposes only and do not represent actual sizes or quantities of elements, and some details may not be drawn completely to simplify the drawings.

Referring to fig. 2, fig. 2 is a schematic diagram of a display device and an automotive head-up display system thereof according to an embodiment of the invention. As shown, the vehicular head-up display system 10 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) and a second image light (not shown). 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 to the surface 111 of the windshield 11 through a first light path P1 and reflecting the second image light to the surface 111 of the windshield 11 through a second light path P2, so as to generate a first virtual image VI1 and a second virtual image VI2, respectively, wherein a distance of the first light path P1 is smaller than a distance of the second light path P2. In one embodiment, the first image light is reflected to the surface 111 of the windshield 11 via at least one first curved mirror 1224, and the second image light is reflected to the surface 111 of the windshield 11 via at least one flat mirror 1222 and at least one first curved mirror 1224.

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 an embodiment, referring to fig. 3, the image source module 121 includes an image panel including a first display area 1211 and a second display area 1212, and the first display area 1211 and the second display area 1212 generate the first image light and the second image light, respectively. In one embodiment, the image source module 121 is a single image panel. In one embodiment, to avoid optical path interference, a small portion of the image panel, labeled as 1213, does not participate in the final imaging but the unused area 1213 can be designed differently according to different mechanisms. In another embodiment, the image panel may further include a third display area (not shown) for generating a third image light, and so on, and the image panel may include two or more display areas for generating two or more image lights. The present invention utilizes a single image source module to divide and utilize the display area of the image source to form a plurality of logically independent display areas which are physically integrated as shown in fig. 3. Fig. 3 illustrates the principle of the division utilization in two display areas. The first display region 1211 and the second display region 1212 in fig. 3 correspond to two virtual images having different final distances. And the segmentation method is not limited to rectangular segmentation, and can be segmentation of any geometric shape, and the image panel can have a part of an unused area for adjusting the system structural space, but is not necessarily configured.

In order to configure a plurality of display areas to different positions in space to form different object distances, the invention utilizes optical imaging modules such as plane mirrors, curved mirrors, lenses and the like to image at least one display area to other positions different from the original image source space; the other display areas are maintained at original positions in space, or are imaged by another optical image transfer system (optical imaging module) to other positions in space (the other positions refer to positions different from the positions where the first image transfer system images the corresponding display areas). To further explain the embodiments of fig. 3 and fig. 4, fig. 4 is a schematic diagram of a display device according to another embodiment of the invention based on the embodiment of fig. 2. As shown in fig. 3 and 4, the image source module 121 is divided into two display regions (a first display region 1211 and a second display region 1212, and an unused region 1213 therebetween), and light emitted from the first display region 1211 is directly emitted to the first curved mirror 1224 and then reflected to the windshield 11 to form a first virtual image (e.g., the first virtual image VI1 in fig. 2). The light emitted from the second display region 1212 is directed to the plane mirror 1222a, and a first virtual relay image RVI1 is generated by the principle of plane mirror imaging; the first relay virtual image RVI1 is reflected and imaged by a plane mirror 1222b to generate a second relay virtual image RVI 2; the second virtual relay image RVI2 is then reflected by the mirror 1222c to form a third virtual relay image RVI 3. Thus, the second display area 1212 is transferred by the optical relay system consisting of the mirrors 1222a,1222b,1222c to a third virtual relay image RVI3, which is different from the original image source position. The third relayed virtual image RVI3 is then projected optically by curved mirror 1224 and windshield 11 to form a second virtual image (e.g., second virtual image VI2 of fig. 2). Since the first display area 1211 and the third relay virtual image RVI3 (the third relay virtual image RVI3 is the transferred image of the second display area 1212) which are not affected by the relay system are at different distances from the curved mirror 1224 and are both located within the focal point F of the curved mirror after reasonable design, the first virtual image VI1 (as shown in fig. 2) and the second virtual image VI2 (as shown in fig. 2) have different virtual image distances from the driver 1, and in one embodiment, a virtual image distance from the imaging position of the second virtual image VI2 (as shown in fig. 2) to the driver 1 is greater than 2 meters. The present invention may transfer at least one display area to other locations in space using an optical imaging system such that multiple display areas have different object distances to the main projection optics (i.e., first curved mirror 1224 in this embodiment).

The embodiment of FIG. 4 is illustrated by an optical imaging module consisting of three flat mirrors. In another embodiment, please refer to fig. 5, wherein fig. 5 is a schematic diagram of a display device according to another embodiment of the present invention based on the embodiment of fig. 2. The only difference from fig. 4 is that the optical imaging module 122 further includes a second curved mirror 1225 disposed on the second optical path P2 between the image source module 121 and at least one first curved mirror 1224, that is, compared to the embodiment of fig. 4, the plane mirror 1222c in the optical imaging module 122 is replaced by the curved mirror 1225, and due to the non-zero optical power introduced by the curved mirror 1225, as shown in fig. 5, the size of the third relay virtual image RVI 3' is larger than the size of the corresponding second display region 1212 (the size of the third relay virtual image RVI3 in fig. 4 is equal to that of the second display region 1212). Alternatively, in an embodiment, as shown in fig. 6, the optical imaging module 122 includes two flat mirrors 1222a,1222b, a curved mirror 1225, and a lens 1226, that is, a lens 1226 is added to the embodiment of fig. 5 to correct the aberration of the magnified image of the curved mirror 1225, wherein the lens 1226 is disposed on the second optical path P2 from the image source module to the curved mirror 1225. This is a general knowledge in the field of optical design and will not be described in detail. It will therefore be appreciated that the design of the optical imaging system can be adapted as required by the person skilled in the art.

According to the above description of the present invention, after the optical relay system is applied, a single image source is converted into a plurality of objects having different object distances from the main projection optical system, and virtual images having different distances are generated according to the principle of gaussian optics. In addition, in order to ensure that the generated virtual image has practical image quality, the main projection system needs to be designed by optimized optics to ensure that each specification meets the HUD imaging requirements. In general, the imaging quality specifications include Modulation Transfer Function (MTF) values, distortion rates, astigmatism, binocular parallax, and the like at cut-off frequencies (cut-off frequencies) determined by image source pixel sizes at each field point within a field of view (FOV). The optimized optical design and evaluation described herein is a general knowledge in the art and will not be described in detail.

To illustrate the automotive heads-up display using a single image source module and having multiple virtual image planes according to the present invention, an embodiment is provided herein. The image source module 121 is a single Liquid Crystal Display (LCD) panel with a size of 57mm × 34mm (2.6 inches diagonal), which is divided into two parts, as shown in fig. 3, the first display area 1211 is 57mm × 14mm, the second display area 1212 is 57mm × 16mm, and an unused area 1213 with an area of 57mm × 4mm is 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 relay system, and the relay system of the second display area 1212 includes three plane mirrors (plane mirrors 1222a,1222b,1222 c).

The windshield 11 used in this embodiment has a curvature of 7500mm in the direction perpendicular to the ground and a curvature of 3000mm in the direction parallel to the ground. If a coordinate system is established with the line of sight of the driver 1 (5 ° downward viewing angle with respect to the ground), as shown in fig. 7, the FOV of the first virtual image VI1 generated by the first display area 1211 is-2.5 ° to 2.5 ° (x direction) and-3.5 ° to-1.5 ° (y direction), and is 2.5m away from the virtual image of the driver 1. The FOV of the second virtual image VI2 generated in the second display region 1212 is-5 ° to 5 ° (x direction) and-0.5 ° to 2.5 ° (y direction), and is a distance of 9m from the virtual image of the driver 1; the range in which both eyes can simultaneously view the first virtual image VI1 and the second virtual image VI2 is 120mm (x direction) and 60mm (y direction), that is, the eyebox (eyebox) range. The surface shape parameters of the curved mirror 1224 of the optical imaging module 122 are described by equation (1), which is a hyperbolic equation with 6 th order aspheric coefficients, as described in the table for the surface shape parameters of the curved mirror of the optical imaging module 122. As shown in fig. 8a and 8b, the light path diagrams of the central field of view points of the two display areas including the eyes of the driver are respectively shown, and it can be seen that the two display areas can respectively use virtual images with different distances from those without using a relay imaging system. Equation (1) defining the curved shape of the curved mirror 1224 of the optical imaging module 122 is as follows:

Watch I (Unit: mm)

In terms of imaging quality, the two key specifications of the two display region grid graph imaging simulation and MTF within the cut-off frequency are illustrated in this embodiment, as shown in fig. 9a and 9b, it can be seen that the distortion rates of virtual images corresponding to the first display region 1211 and the second display region 1212 are very slight and less than 5%; as shown in fig. 10a and 10b, the MTF values of the first display 1211 and the second display 1212 are both greater than 0.5 at the cut-off frequency (8 cycles/mm) determined by the LCD pixel size, which is a diffraction limited system that can be imaged clearly according to the general knowledge of visual imaging optics.

According to the display device and the vehicle head-up display system thereof, the image source module of the display device can provide at least two image sources to form a plurality of logically independent display areas which are physically integrated; the optical imaging module of the display device at least comprises at least one plane mirror and at least one curved mirror, and can flexibly perform different image rotation configurations according to different image source modules so as to clearly image into at least two virtual images.

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

The above-mentioned embodiments are merely illustrative of the technical spirit and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the content of the present invention and to implement the same, so that the scope of the present invention should not be limited by the above-mentioned embodiments, and all equivalent changes and modifications made in the spirit of the present invention should be covered by the scope of the present invention.

Claims

1. A head-up display system for a vehicle, comprising:

A windshield connected to a body of a vehicle and having a surface reflecting light; and

A display device, comprising:

The image source module is arranged in the vehicle body and used for generating a first image light and a second image light; and

An optical imaging module set on the light-emitting side of the image source module set, the optical imaging module set includes at least one plane mirror and at least one first curved mirror to reflect the first image light to the surface of the windshield via a first light path and reflect the second image light to the surface of the windshield via a second light path to generate a first virtual image and a second virtual image respectively, wherein the distance of the first light path is less than that of the second light path.

2. The vehicle head-up display system of claim 1, wherein the image source module comprises a liquid crystal display module, a digital light processing module, a liquid crystal on silicon display module, and a laser display module.

3. The vehicular head-up display system according to claim 1, wherein the image source module comprises 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 first image light and the second image light.

4. The vehicular head-up display system according to claim 1, wherein the first image light is reflected to the windshield via the at least one first curved mirror, and the second image light is reflected to the windshield via the at least one flat mirror and the at least one first curved mirror.

5. The vehicular head-up display system of claim 1, wherein the optical imaging module further comprises a second curved mirror or the optical imaging module further comprises a second curved mirror and a lens disposed on the second optical path from the image source module to the at least one first curved mirror.

6. A display device, comprising:

The image source module is arranged in a vehicle body of a vehicle and used for generating a first image light and a second image light; and

An optical imaging module set on the light-emitting side of the image source module set, the optical imaging module set includes at least one plane mirror and at least one first curved mirror to reflect the first image light to the surface of the windshield via a first light path and reflect the second image light to the surface of the windshield via a second light path to generate a first virtual image and a second virtual image respectively, wherein the distance of the first light path is less than the distance of the second light path.

7. The display device of claim 6, wherein the image source module comprises a liquid crystal display module, a digital light processing module, a liquid crystal on silicon display module, and a laser display module.

8. The display device as claimed in claim 6, wherein the image source module comprises an image panel including a first display region and a second display region, and the first display region and the second display region respectively generate the first image light and the second image light.

9. the display apparatus of claim 6, wherein the first image light is reflected to the windshield via the at least one first curved mirror, and the second image light is reflected to the windshield via the at least one flat mirror and the at least one first curved mirror.

10. The display apparatus of claim 6, wherein the optical imaging module further comprises a second curved mirror or the optical imaging module further comprises a second curved mirror and a lens disposed on the second optical path from the image source module to the at least one first curved mirror.