CN111552085B

CN111552085B - Head-up display device and manufacturing process thereof

Info

Publication number: CN111552085B
Application number: CN202010586247.1A
Authority: CN
Inventors: 林柏青
Original assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; General Interface Solution Ltd
Current assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; General Interface Solution Ltd
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2023-03-28
Anticipated expiration: 2040-06-24
Also published as: TWI746032B; TW202201072A; CN111552085A

Abstract

The invention provides a head-up display device, which comprises a first lens group and an image generation unit. The image generating unit is attached to the first lens group by a co-forming process, and the image generating unit is used for generating a two-dimensional image and projecting the two-dimensional image onto a target projection surface to form a virtual image. The first lens group has a curvature to adjust the distortion of the virtual image, so as to solve the distortion problem of the virtual image. In addition, the head-up display device does not need an aspheric projection mirror and a reflecting mirror, so the volume can be greatly reduced.

Description

Head-up display device and manufacturing process thereof

Technical Field

The present invention relates to a Head Up Display (HUD) device, and more particularly, to a head up display device that can solve the problem of virtual image distortion and has a small size.

Background

The head-up display device can enable the information provided by the information system in the vehicle to be displayed at the sight line position of the driver when the driver drives, so that the driver can obtain the information without lowering the head, and the danger caused by short time that the driver cannot pay attention to the external road condition due to the fact that the driver lowers the head to watch the displayed information system is avoided. For example, the information may be the speed of the vehicle, so that the driver can know the speed of the vehicle without looking down at the dashboard, thereby improving the safety. The head-up display device may be classified into a combination head-up display (C-HUD), a windshield head-up display (W-HUD), and an augmented reality head-up display (AR-HUD), in which the augmented reality head-up display is a combination of an Augmented Reality (AR) technology and a head-up display technology. Compared with combined head-up display and windshield type head-up display, the augmented reality head-up display has a larger field angle and a longer imaging distance, can directly superimpose the display effect on a real road surface, and brings better experience to a driver. The size of the field of view determines the field of view of the optical device, with a larger field of view being the larger the field of view. The field of view of a conventional windshield head-up display is typically at 5 °, while the field of view of an augmented reality head-up display is 10 ° or greater.

Fig. 1 shows a schematic view of a conventional augmented reality head-up display device applied to an automobile, and an augmented reality head-up display device 10 includes an image generation unit (PGU) 12, a reflector 14 and an aspheric projection mirror 16. The mirror 14 is used for reflecting the two-dimensional image L1 emitted by the image generating unit 12. Since the front windshield 22 of the automobile is generally curved glass with a radian, and the degrees of deformation of the curved surfaces at different positions are different, if the two-dimensional image L1 reflected by the reflector 14 is directly projected onto the front windshield 22, human eyes 20 will see a distorted virtual image 26, as shown in fig. 2. To solve the distortion problem, the light is first modified by the aspheric projection lens 16 before being projected onto the front windshield 22, so that the human eye 20 sees a normal virtual image 26, as shown in fig. 3. In addition to using the aspherical projection mirror 16, the distortion problem can also be solved through software algorithms. In addition, the eye tracking sensor 24 shown in fig. 1 can emit an Infrared (IR) light to the human eye 20 to sense the pupil position, so as to achieve image determination and tracking.

However, a larger field of view means that a sufficiently large mirror 14 and optical path design are required, which results in an excessively large volume of the augmented reality head-up display device 10, and the lower augmented reality head-up display device 10, especially the front-loading type augmented reality head-up display, requires enough space for the automobile to be placed. At present, for a head-up display device with double projection positions, the field angle of near projection is 5 degrees × 1 degree, the imaging distance is 2.4 meters, and state information selected by a driver, such as speed, speed limit and some Advanced Driver Assistance Systems (ADAS) functions, is mainly displayed. The far projection field angle is 10 degrees by 4.8 degrees, the imaging distance can reach 7.5 meters, the augmented reality mark can be directly displayed on the road surface, and the augmented reality head-up display device needs more than 13 liters of volume.

Disclosure of Invention

One objective of the present invention is to provide a head-up display device and a manufacturing process thereof that can solve the problem of virtual image distortion.

One objective of the present invention is to provide a small-sized head-up display device and a manufacturing process thereof.

One objective of the present invention is to provide a vehicle head-up display device and a manufacturing process thereof.

According to the present invention, a head-up display device includes a first lens group and an image generating unit. The image generating unit is formed on the first lens group by a co-forming process, and the image generating unit is used for emitting a two-dimensional image to be projected on a target projection surface to generate a virtual image. The first lens group has a curvature to improve the distortion of the virtual image to generate a normal virtual image. The head-up display device of the invention solves the distortion problem of the virtual image without an aspheric projection lens. The head-up display device of the invention does not need an aspheric projection mirror and a reflecting mirror, so the volume can be greatly reduced.

According to the present invention, a process for manufacturing the above-mentioned head-up display device comprises: providing the first lens group; an image generating unit is formed on the first lens group, the image generating unit includes a substrate and a plurality of light emitting elements, and the plurality of light emitting elements are disposed on the substrate. The first lens group has a curvature to improve the distortion of the virtual image to generate a normal virtual image. The head-up display device produced by the manufacturing process of the invention has no aspheric projection mirror and reflector, so the volume can be greatly reduced.

The head-up display device of the invention can be arranged in a vehicle, the front window of the vehicle is a half mirror, the reflecting surface of the half mirror is used as the target projection surface, and when a two-dimensional image is projected on the target projection surface, the virtual image is formed in front of the half mirror and outside the vehicle.

Drawings

Fig. 1 is a schematic diagram illustrating a conventional augmented reality head-up display device applied to a vehicle.

Figure 2 shows a distorted virtual image.

Fig. 3 shows a normal virtual image.

Fig. 4 shows a first embodiment of a head-up display device according to the invention.

Fig. 5 shows an exploded view of a first embodiment of a heads-up display device according to the invention.

FIG. 6 shows a process of fabricating the head-up display device of FIG. 4.

Fig. 7 shows an embodiment in which the head-up display apparatus of fig. 4 is applied to a vehicle.

Fig. 8 shows a second embodiment of a head-up display device according to the invention.

Fig. 9 shows an exploded view of a second embodiment of a heads-up display device according to the invention.

Fig. 10 shows a third embodiment of a heads-up display device according to the invention.

Reference numerals:

an augmented reality heads-up display device

An image generation unit

A reflector

An aspheric projection mirror

A human eye

Front windshield

An eye tracking sensor

Virtual image

Head-up display device

A first lens group

An image generation unit

36

A light emitting element

Light emitting element

A light emitting device

Light emitting element

A light emitting face

48

Bottom plate

Routing of

56.

58.

A control substrate

Head-up display device

A second lens group

A film layer

66.

68.

Detailed Description

Fig. 4 shows a first embodiment of a head-up display device according to the invention. Fig. 5 shows an exploded view of a first embodiment of a heads-up display device according to the invention. The head-up display device 30 of fig. 4 and 5 may be disposed in a vehicle. The head-up display device 30 includes a first lens group 32 and an image generating unit 34, wherein the first lens group 32 and the image generating unit 34 form a projection optical system. First lens elements 32 may be, but not limited to, aspherical lens elements formed by precision grinding and plastic injection molding, first lens elements 32 may be, but not limited to, polycarbonate (PC) or polymethyl methacrylate (PMMA), the curvature of first lens elements 32 may be derived by using an optical simulation path, and first lens elements 32 may be, but not limited to, aspherical lens elements formed by precision grinding and plastic injection molding, and may have a free-form surface. The image generating unit 34 is a flexible display member and can be attached to the first lens set 32 by co-molding process, so that the image generating unit 34 is completely attached to the first lens set 32. In one embodiment, the image generating unit 34 may be attached by Optical Clear Adhesive (OCA). The image generation unit 34 projects a two-dimensional image L1 onto a target projection surface 23 (shown in fig. 7) to form a virtual image 26 (shown in fig. 7). The distortion of virtual image 26 is adjusted by the curvature of first lens group 32. The image generating unit 34 has a substrate 36 and a plurality of

light emitting elements

38, 40, 42, 44, wherein the plurality of

light emitting elements

38, 40, 42, 44 are disposed on the substrate 36. Substrate 36 is a flexible substrate that is completely attached to the surface of first lens assembly 32 by a co-forming process. The substrate 36 has a plurality of traces 54 and bonding pads 56 (as shown in fig. 6), the plurality of traces 54 are electrically connected to the plurality of light emitting

devices

38, 40, 42, 44, so that the plurality of light emitting

devices

38, 40, 42, 44 can be driven by the plurality of traces 54. The light-emitting

elements

38, 40, 42, 44 can be, but are not limited to, micro light-emitting diodes (LEDs) with a size of 10 to 100 micrometers, and the light-emitting surfaces 46 of the light-emitting

elements

38, 40, 42, 44 face away from the first lens group 32, so that the light emitted by the light-emitting

elements

38, 40, 42, 44 does not emit toward the first lens group 32. The plurality of

light emitting elements

38, 40, 42, 44 include first

light emitting elements

38, 40, 42 and second light emitting elements 44. The first

light emitting elements

38, 40, and 42 are light emitting diodes for providing red, green, and blue light, respectively, and the light emitted from the first

light emitting elements

38, 40, and 42 forms a two-dimensional image L1. The second light emitting element 44 provides light required by the eye tracking sensor 24 (as shown in fig. 7), for example, the second light emitting element 44 may be a light emitting diode for emitting infrared light to the pupil of the user, so that the eye tracking sensor 24 can determine the pupil position to know the viewing position of the user. In other embodiments, the image generating unit 34 may also be a Liquid Crystal Display (LCD), a Digital Light Processing (DLP), or a Laser Beam Scanning (LBS). In the embodiment of fig. 4, the first lens group 32 is a lens group with lens function, and in other embodiments, the first lens group 32 can be replaced by an aspheric substrate without lens function.

FIG. 6 shows a process of fabricating the head-up display device 30 of FIG. 4. In step S10, a flexible substrate 36 is formed on a bottom plate 50. In steps S12 and S14, traces 54 and bonding pads 56 are sequentially formed on the substrate 36. In step S16, a plurality of light emitting

devices

38, 40, 42, 44 are disposed on the substrate 36 through a Mass Transfer (Mass Transfer) process and electrically connected to the traces 54 and the bonding pads 56. The plurality of

light emitting elements

38, 40, 42, 44 and the substrate 36 constitute an image generating unit 34.

Step S18 is an encapsulation process, in which the

light emitting elements

38, 40, 42, 44 are encapsulated by using an organic material or an inorganic material, such as but not limited to, epoxy (Epoxy) or Acrylic (Acrylic), to generate an encapsulating shell 58 covering the

light emitting elements

38, 40, 42, 44, wherein the inorganic material may be but not limited to silicon dioxide (SiO 2), aluminum oxide (Al 2O 3), silicon nitride (SiNx), or silicon oxynitride (SiON). In step S20, the image generating unit 34 is removed from the base plate 50. In step 22, a co-molding (conformal) process is performed to attach the image generating unit 34 to the first lens assembly 32, since the substrate 36 of the image generating unit 34 is flexible, the substrate 36 can be completely attached to the surface of the first lens assembly 32, such that the

light emitting devices

38, 40, 42, and 44 can be arranged along the curvature of the surface of the first lens assembly 32. Finally, a bonding process is performed with a control substrate 59 to obtain the head-up display device 30, as shown in step S24.

Fig. 7 shows an embodiment in which the head-up display apparatus 30 of fig. 4 is applied in a vehicle. The head-up display device 30 is placed on the side of the front windshield 22. The image generating unit 34 of the head-up display device 30 projects the two-dimensional image L1 onto a target projection surface 23, so as to generate a virtual image 26 in the human eye 20, wherein the target projection surface 23 is a reflective surface of the front windshield 22, and the front windshield 22 is a half mirror located outside the projection optical system formed by the first lens group 32 and the image generating unit 34 and is a front window of the vehicle. The virtual image 26 is formed in front of the half mirror and outside the vehicle, that is, in front of the other side of the target projection surface 23 when the two-dimensional image L1 is projected to one side of the target projection surface 23. The light emitting device 44 of the image generating unit 34 provides infrared light to the pupil of the user, so that the eyeball tracking sensor 24 can perform image determination and tracking, and further know the viewing position of the user. Since the curvature of the first lens group 32 in the head-up display device 30 is designed according to the curvature of the front windshield 22, and the

light emitting elements

38, 40, and 42 of the image generating unit 34 are arranged along the curvature of the surface of the first lens group 32, the curvature of the first lens group 32 can make the two-dimensional image L1 emitted by the

light emitting elements

38, 40, and 42 conform to the curvature change of the front windshield 22, so that the head-up display device 30 of the present invention can solve the problem of virtual image distortion without the aspheric projection lens 16 or software algorithm, and generate the normal virtual image 26. Compared to the augmented reality head-up display device 10 of fig. 1, the head-up display device 30 of the present invention does not need the reflector 14 and the aspheric projection mirror 16, so that the volume can be greatly reduced. As shown in fig. 7, the head-up display device 30 may be disposed on a rotatable bracket 48, and the user may adjust the rotatable bracket 48 to change the projection position of the two-dimensional image L1. The embodiment of fig. 7 is for illustration only and is not intended to represent the head-up display of the present invention as applicable to only a vehicle.

Fig. 8 shows a second embodiment of a head-up display device according to the invention. Fig. 9 shows an exploded view of a second embodiment of a heads-up display device according to the invention. The head-up device 60 shown in fig. 8 and 9 includes the first lens group 32 and the image generating unit 34, as with the head-up display device 30 shown in fig. 4 and 5, but the head-up display device 60 further includes a second lens group 62 formed on a side of the image generating unit 34 opposite to the first lens group 32, i.e. the image generating unit 34 is sandwiched between the first lens group 32 and the second lens group 62. In the head-up display device 60 of fig. 8, the first lens group 32, the image generating unit 34 and the second lens group 62 form a projection optical system. The distance between the second lens group 62 and the first lens group 32 is 55-535 microns. The second lens group 62 is disposed on the light emitting surface 46 of the

light emitting devices

38, 40, 42, 44 for correcting the imaging distance, size, position and viewing angle of the virtual image 26, and the second lens group 62 has a film 64 and at least one optical device 66. The at least one optical element 66 is used to correct the imaging distance and the viewing angle of the virtual image 26. In one embodiment, at least one optical element 66 can be attached to the image generating unit 34 through an optical adhesive. In another embodiment, at least one optical element 66 can be formed by in-mold molding, so that the first lens group 32, the image generating unit 34 and the second lens group 62 are integrally formed, and the light-emitting

elements

38, 40, 42, 44 and the wires 54 are embedded in the second lens group 62. The at least one optical element 66 is not limited to being formed using in-mold injection molding. The at least one optical element 66 may be, but is not limited to, a waveguide (waveguide) lens assembly or a lens assembly formed by stacking a plurality of concave-convex lenses (hereinafter referred to as a concave-convex lens assembly). The waveguide lens group has many microstructures (waveguide structures) to guide light to increase the imaging distance and enlarge the viewing angle. The concave-convex lens group can fold the light path to adjust the size and the position of the image. The at least one optical element 66 may also be a combination of a waveguide mirror group and an concave-convex mirror group, such as a concave-convex mirror group with a waveguide structure or a waveguide mirror group with a lens function. The two-dimensional image L1 generated by the image generating unit 34 is magnified by the second lens group 62 and projected on the target projection surface 23 to generate the virtual image 26. The process steps of the head-up display device 60 are almost the same as those shown in fig. 6, except that after the head-up display device 60 completes step S24, a step is performed to form the second lens group 62 on the side of the image generating unit 34 opposite to the first lens group 32.

Fig. 10 shows a third embodiment of a heads-up display device according to the invention. The head-up display device 68 in fig. 10 includes the first lens group 32, the image generating unit 34, and the second lens group 62 as the head-up display device 60 in fig. 8, and the difference is that the

light emitting elements

38, 40, 42, and 44 of the head-up display device 68 are disposed between the first lens group 32 and the substrate 36, and the light emitting surfaces 46 of the

light emitting elements

38, 40, 42, and 44 face the first lens group 32, so that the two-dimensional image L1 emitted by the image generating unit 34 is reflected by the first lens group 32 and then amplified by the second lens group 62, and the amplified two-dimensional image L1 is projected on the target projection surface 23 to form the virtual image 26. The head-up display device 68 is manufactured in a process similar to the head-up display device 60, except that the light-emitting surfaces 46 of the light-emitting

elements

38, 40, 42, 44 are oriented in different directions when the image generating unit 34 is attached to the first lens group 32 (step 22 in fig. 6).

The foregoing description of the preferred embodiments of the present invention has been presented for purposes of illustration and description and is not intended to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the embodiments of the invention, which are presented for purposes of illustration and description of the principles of the invention and of enabling those skilled in the art to practice the invention in various embodiments and are intended to be determined by the following claims and their equivalents.

Claims

1. A head-up display device for projecting a two-dimensional image onto a target projection surface to form a virtual image, the head-up display device comprising:

a projection optical system, comprising:

a first lens group; and

an image generating unit formed on the first lens group for emitting the two-dimensional image, the image generating unit including a substrate and a plurality of light emitting elements disposed on the substrate;

a second lens group formed on a side of the image generating unit opposite to the first lens group for correcting an imaging distance, size, position and viewing angle of the virtual image, wherein the image generating unit is interposed between the first lens group and the second lens group;

wherein the virtual image is formed in front of one side of the target projection surface when the two-dimensional image is projected on the other side of the target projection surface;

wherein, the plurality of light-emitting elements are arranged along the curvature of the surface of the first lens group;

the two-dimensional image sent by the image generating unit is not required to be reflected to the target projection surface through an aspheric projection mirror and a reflector;

wherein the substrate is completely attached to the surface of the first lens group by a co-forming process.

2. The heads-up display device of claim 1 wherein the spacing between the second set of mirrors and the first set of mirrors is in the range of 55 microns to 535 microns.

3. The head-up display device of claim 1, wherein the second lens group is disposed on a light-emitting surface of the plurality of light-emitting elements.

4. The heads-up display device of claim 1 wherein the two-dimensional image is magnified by the second lens group and projected onto the target projection surface after being reflected by the first lens group.

5. The head-up display device according to claim 1, wherein the second lens group comprises a waveguide lens group, an concave-convex lens group or a combination of the waveguide lens group and the concave-convex lens group.

6. The head-up display device according to claim 1, further comprising a plurality of traces on the substrate, the plurality of traces electrically connecting the plurality of light emitting elements.

7. The head-up display device according to claim 6, wherein the second lens group has a film layer and at least one optical element for modifying the image distance, size, position and viewing angle of the virtual image, the at least one optical element is formed by in-mold injection so that the first lens group, the image generating unit and the second lens group are integrally formed, and the light emitting elements and the traces are embedded in the second lens group.

8. The head-up display device of claim 1 wherein the substrate is a flexible substrate.

9. The head-up display device of claim 1 wherein said first lens group is adapted to adjust distortion of said virtual images.

10. The heads-up display device of claim 1 wherein the plurality of light emitting elements comprise light emitting diodes that emit red, green, and blue light, respectively, to form the two-dimensional image.

11. The head-up display device of claim 1, wherein the plurality of light-emitting elements comprise a light-emitting diode that emits infrared light, and the viewing position of the user is known by reflecting the emitted infrared light to the pupil of the user.

12. A process for a heads-up display device for projecting a two-dimensional image onto a target projection surface to form a virtual image, the process comprising the steps of:

providing a first lens group; and

forming an image generating unit on the first lens group, wherein the image generating unit is used for emitting the two-dimensional image and comprises a substrate and a plurality of light-emitting elements, and the plurality of light-emitting elements are arranged on the substrate;

forming a second lens group on one side of the image generation unit relative to the first lens group for correcting the imaging distance, size, position and viewing angle of the virtual image;

the step of forming an image generating unit on the first lens group comprises completely bonding the substrate and the surface of the first lens group by a co-forming process.

13. The process of claim 12, further comprising a step of setting a distance between said second lens group and said first lens group to be 55-535 μm.

14. The process of claim 12, further comprising forming said second lens group on a light emitting surface of said plurality of light emitting devices.

15. The process of claim 12, wherein said step of forming said second lens group comprises forming said second lens group using a waveguide lens group, an meniscus lens group, or a combination of said waveguide lens group and said meniscus lens group.

16. The process of claim 12, further comprising forming a plurality of traces on the substrate to electrically connect the plurality of light emitting devices.

17. The process of claim 16, wherein said step of forming said second lens group comprises using an in-mold molding technique to integrate said first lens group, said image generating unit and said second lens group, and embedding said light emitting devices and said traces in said second lens group.

18. The process of claim 12, wherein the substrate is a flexible substrate.

19. The process of claim 12, wherein said first lens groups are used to adjust distortion of said virtual images.

20. The process of claim 12, wherein forming an image generating unit over said first lens group comprises:

forming the substrate on a bottom plate;

forming a plurality of routing lines on the substrate;

arranging the plurality of light-emitting elements on the substrate and electrically connecting the plurality of light-emitting elements with the plurality of wires, wherein the plurality of light-emitting elements and the substrate form the image generation unit;

packaging the plurality of light emitting elements;

removing the image generation unit from the base plate;

attaching the image generating unit to the first lens group by a co-molding process; and

and carrying out a bonding process on the image generation unit.