Off-axis double-focal-plane HUD optical system

Abstract

The utility model discloses an off-axis bifocal plane HUD optical system, which comprises an image source, an eye box, a lens, a first reflecting mirror, a second reflecting mirror and an automobile windshield, the image source comprises a first output part and a second output part, light of the first output part passes through the first reflecting mirror, the second reflecting mirror and the automobile windshield to enable the eye box to obtain a near focal plane, and light of the second output part passes through the first reflecting mirror, the second reflecting mirror and the automobile windshield. The light of the second output part passes through the lens, the first reflecting mirror, the second reflecting mirror and the automobile windshield to enable the eye box to obtain a far focal plane. The image source is divided into two parts, the lens is arranged on the light path of the second output part of the image source, and a near-focus virtual image and a far-focus virtual image are formed in front of the windshield, so that a driver can see the virtual image surface and timely obtain the driving information of the vehicle under the condition of poor visual field such as vehicle following or traffic jam, and the driving safety of the vehicle is improved. Therefore, the thickness of the crystalline lens can be adjusted when human eyes watch far and near focuses, and fatigue caused by long-time observation of a certain focal plane is avoided.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the head-up display technical field, concretely relates to a kind of off-axis bifocal HUD optical system. BACKGROUND

[0002] With the development of science and technology, head-up display systems are increasingly used on vehicles. The head-up display system on the vehicle can display important driving information, such as speed, engine revolutions, fuel consumption, tire pressure, navigation, and information from external smart devices, in the driver's field of view on the front windshield. This allows the driver to see the driving information without lowering his head, thereby avoiding distraction from the road ahead. At the same time, the driver does not need to adjust his eyes between observing the road in the distance and the instruments nearby, which can prevent eye fatigue and greatly enhance driving safety and improve the driving experience.

[0003] The existing traditional head-up display has the characteristics of large FOV and high imaging quality, and basically only has one far focal plane for displaying information. Due to the relatively long virtual image distance, when stuck in traffic or following a car, the front vehicle blocks the virtual image, which is mapped to the inside of the front car, making it difficult for the driver to see the virtual image information and understand the current state of the car. SUMMARY

[0004] (1) Technical problem to be solved

[0005] To overcome the shortcomings of the prior art, the present utility model aims to provide an off-axis bifocal HUD optical system to solve the problem that the existing head-up display is blocked by the front vehicle when stuck in traffic or following a car, the virtual image is mapped to the inside of the front car, making it difficult for the driver to see the virtual image information and understand the current state of the car.

[0006] (2) Technical solution

[0007] To solve the above technical problems, the present utility model provides an off-axis bifocal HUD optical system, which comprises an image source, an eyebox, a lens, a first mirror, a second mirror and a vehicle windshield. The image source is used to output the displayed image, and the eyebox is used to receive the image output by the image source. The image source comprises a first output part and a second output part. The light rays of the first output part pass through the first mirror, the second mirror and the vehicle windshield to make the eyebox obtain a near focal plane. The light rays of the second output part pass through the lens, the first mirror, the second mirror and the vehicle windshield to make the eyebox obtain a far focal plane.

[0008] Preferably, the lens is arranged on the optical path between the second output part and the first mirror, and the first mirror and the second mirror are both arranged on the optical path of the first output part and the second output part.

[0009] Further, the lens comprises a first optical surface and a second optical surface.

[0010] Still further, the lens is a single free-form surface mirror or a double free-form surface mirror.

[0011] Still further, the first mirror is used for reflecting the light emitted by the first output part and the lens for the first time, the second mirror is used for reflecting the light reflected by the first mirror for the second time, and the automobile windshield is used for reflecting the light reflected by the second mirror to the eyebox.

[0012] Still further, the first mirror and the second mirror are a combination of a free-form surface mirror and a free-form surface mirror.

[0013] Still further, the first mirror and the second mirror are a combination of a plane mirror and a free-form surface mirror.

[0014] Advantages

[0015] Compared with the prior art, the present application has the following advantages:

[0016] The present application divides the image source into two parts, and sets a lens on the light path of the second output part of the image source, so that the light of the image source enters the eyes of the person after being reflected by the automobile windshield, and forms virtual images of near focus and far focus at positions in front of the windshield, and the near and far focus surfaces are displayed simultaneously. The driver can switch between the near focus and the far focus to ensure that the driver can see the virtual image surface even in poor visibility conditions such as following a car or being stuck in traffic, and timely obtain the driving information of the vehicle. When the person watches the near and far focus, the thickness of the lens is adjusted, and the fatigue caused by long-time observation of a certain focus surface is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a light path schematic diagram of the present application.

[0018] Figure 2 is a reflected light path schematic diagram of the lens of the present application.

[0019] Figure 3 is a lens schematic diagram of the present application.

[0020] Figure 4 is an image source schematic diagram of the present application.

[0021] The marks in the drawings are: 1, image source; 2, eyebox; 3, lens; 4, first mirror; 5, second mirror; 6, automobile windshield; 7, near focus surface; 8, far focus surface; 101, first output part; 102, second output part; 301, first optical surface; 302, second optical surface. DETAILED DESCRIPTION

[0022] This specific embodiment is an off-axis dual-focal-surface HUD optical system, such as Figures 1-4 As shown, it includes an image source 1 and an eye box 2. The image source 1 is used to output the displayed image, and the eye box 2 is used to receive the image output by the image source 1.

[0023] The image source 1 includes a lens 3, a first reflector 4, a second reflector 5, and a car windshield 6. The image source 1 includes a first output unit 101 and a second output unit 102. The first output unit 101 and the second output unit 102 can respectively emit some basic information such as battery level and fuel level and display some information images such as navigation. The light from the first output unit 101 passes through the first reflector 4, the second reflector 5, and the car windshield 6 to make the eye box 2 obtain a near focal surface 7. The light from the second output unit 102 passes through the lens 3, the first reflector 4, the second reflector 5, and the car windshield 6 to make the eye box 2 obtain a far focal surface 8.

[0024] Image source 1 is divided into two parts. The eye box 2 is where the driver's eyes are located and information can be seen. The first output unit 101 and the second output unit 102 are used to image at the near focal plane 7 and the far focal plane 8, respectively.

[0025] like Figure 1 As shown: In this embodiment, the lens 3 is disposed in the optical path between the second output section 102 and the first reflector 4. The first reflector 4 and the second reflector 5 are both disposed in the optical paths of the first output section 101 and the second output section 102. In this way, the light emitted from the first output section 101 of the image source 1 will not pass through the lens 3. By disposing of the lens 3 in the optical path of the second output section 102, the optical path distance of the far focal point is adjusted so that the near and far focal points are focused on the image plane at the same time. At this time, the near focal plane 7 and the far focal plane 8 are not on the same axis.

[0026] Similarly, the freeform lens 3 can also be placed in the optical path between the first output section 101 and the first reflecting mirror 4, and the optical path distance of the near focus can be adjusted so that the near and far focus are focused on the image plane at the same time.

[0027] like Figure 2 and Figure 3 As shown: In this embodiment, the lens 3 includes a first optical surface 301 and a second optical surface 302. The lens 3 is a single freeform surface mirror or a double freeform surface mirror. Specifically, the lens 3 can be a single freeform surface lens, that is, one surface is a freeform surface, or it can be a double freeform surface lens, that is, two surfaces are freeform surfaces, depending on the design requirements.

[0028] like Figure 1As shown: in this embodiment, the first mirror 4 is used for the first reflection of the light emitted by the first output part 101 and the lens 3, the second mirror 5 is used for the second reflection of the light reflected by the first mirror 4, and the automobile windshield 6 is used for reflecting the light reflected by the second mirror 5 to the eyebox 2.

[0029] In this way, the light emitted by the image source 1 passes through the first mirror 4 and the second mirror 5 in turn, enters the human eye after being reflected by the automobile windshield 6, and forms a virtual image, displaying some information such as navigation.

[0030] In this embodiment, the first mirror 4 and the second mirror 5 are a combination of free-form mirrors, and the free-form mirror is a kind of aspheric mirror, the shape of which can be freely designed and manufactured, and various optical curves can be customized according to specific needs, which can realize more complex light refraction and reflection effects, and the combination design of the free-form mirror can realize more flexible optical performance to meet the application requirements.

[0031] As shown: in this embodiment, the first mirror 4 and the second mirror 5 are a combination of plane mirrors and free-form mirrors. Figure 1

[0032] Working principle: when working, the light emitted by the second output part 102 of the image source 1 passes through the free-form lens 3, the first mirror 4 and the second mirror 5 in turn, enters the human eye after being reflected by the automobile windshield 6, and forms a far focal plane 8, and the light emitted by the first output part 101 of the image source 1 passes through the first mirror 4 and the second mirror 5 in turn, enters the human eye after being reflected by the automobile windshield 6, and forms a near focal plane 7.

[0033] The off-axis bifocal AR-HUD has two image planes, namely the far focal plane 8 and the near focal plane 7, and the far and near refer to the distance of the focal plane from the driver, and the off-axis means that the down-view angles of the far focal plane 8 and the near focal plane 7 are not consistent, wherein the down-view angle of the near focal plane 7 is larger, and it displays some basic information such as electric quantity and oil quantity; the down-view angle of the far focal plane 8 is smaller, and it displays some information such as navigation, and the far and near focal planes can be displayed at the same time, and the thickness of the lens will be adjusted when the human eye watches the far and near focal planes, avoiding the fatigue caused by long-time observation of a certain focal plane.

[0034] All the technical features in this embodiment can be freely combined according to actual needs.

[0035] The above embodiment is a preferred implementation scheme of the present application, and in addition, the present application can be implemented in other ways, and any obvious replacement without departing from the technical scheme concept is within the protection scope of the present application.​

Claims

1. An off-axis bifocal HUD optical system characterized in that, The application relates to a head-up display device for a vehicle, comprising: an image source (1) for outputting a displayed image and an eyebox (2) for receiving the image output by the image source (1); a lens (3), a first mirror (4), a second mirror (5) and a vehicle windshield (6), wherein the image source (1) comprises a first output part (101) and a second output part (102), light rays of the first output part (101) pass through the first mirror (4), the second mirror (5) and the vehicle windshield (6) to make the eyebox (2) obtain a near focus surface (7), and light rays of the second output part (102) pass through the lens (3), the first mirror (4), the second mirror (5) and the vehicle windshield (6) to make the eyebox (2) obtain a far focus surface (8).

2. The off-axis bifocal HUD optical system of claim 1, wherein, The lens (3) is arranged on an optical path between the second output part (102) and the first mirror (4), and the first mirror (4) and the second mirror (5) are arranged on optical paths of the first output part (101) and the second output part (102).

3. The off-axis bifocal HUD optical system of claim 2, wherein, The lens (3) comprises a first optical surface (301) and a second optical surface (302).

4. The off-axis bifocal HUD optical system of claim 3, wherein, The lens (3) is a single free-form surface mirror or a double free-form surface mirror.

5. The off-axis bifocal HUD optical system of claim 4, wherein, The first mirror (4) is used for reflecting light rays emitted by the first output part (101) and the lens (3) for the first time, the second mirror (5) is used for reflecting the light rays reflected by the first mirror (4) for the second time, and the vehicle windshield (6) is used for reflecting the light rays reflected by the second mirror (5) to the eyebox (2).

6. The off-axis bifocal HUD optical system of claim 5, wherein, The first mirror (4) and the second mirror (5) are a combination of a free-form surface mirror and a free-form surface mirror.

7. The off-axis bifocal HUD optical system of claim 5, wherein, The first mirror (4) and the second mirror (5) are a combination of a plane mirror and a free-form surface mirror.

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