Head-up display system

Abstract

The utility model discloses a head-up display system, and relates to the technical field of optical imaging, the head-up display system comprises an image source, an optical waveguide and display glass, image light emitted by the image source is transmitted by the optical waveguide and then is emitted to the display glass, and the image light is reflected on the display glass and then is emitted to a target observation position; and the rotation driving device is connected with the optical waveguide and is used for driving the optical waveguide to rotate, so that stray light cannot enter the target observation position, and the light intensity of the stray light is greater than a preset light intensity threshold. Therefore, by arranging the rotary driving device connected with the optical waveguide, the rotary driving device drives the optical waveguide to rotate so as to move the external stray light to the outside of the target observation position, so that the stray light with relatively high light intensity is prevented from entering the target observation position to influence the virtual image effect of the image light; the negative influence of stray light on the head-up display system is effectively eliminated, and the display effect of the head-up display system is improved.

Description

Technical Field

[0001] The present application relates to the field of optical imaging technology, and more specifically, to a head-up display system. Background Art

[0002] With the development of intelligent driving technology, traditional instruments can no longer meet the safety, intelligence and immersive experience needs of vehicle users. Head-up displays (HUD) have come into being. By projecting information such as driving status, navigation and assisted driving directly in front of vehicle users, the driving experience is improved. As a new generation of head-up display products, augmented reality head-up displays (AR-HUD) have a longer imaging distance and a larger field of view, which can effectively improve driving safety.

[0003] In the known design schemes of HUD, an optical waveguide is generally used to realize the spatial optical propagation of the projection pattern. The optical waveguide includes a glass plate, and a diffraction grating or a hologram is arranged inside the glass plate. This scheme makes external incident light, such as sunlight, also reflected or diffracted by the optical waveguide, so that these stray lights will also enter the user's eyes, interfere with the HUD image display effect, and produce glare in severe cases. Utility Model Content

[0004] The present application proposes a head-up display system to improve the above-mentioned defects.

[0005] In a first aspect, an embodiment of the present application provides a head-up display system, comprising: an image source, an optical waveguide and a display glass, wherein the image light emitted by the image source is transmitted through the optical waveguide and then emitted toward the display glass, and then reflected on the display glass and emitted to a target observation position; a rotational drive device, wherein the rotational drive device is connected to the optical waveguide and is used to drive the optical waveguide to rotate so that stray light cannot enter the target observation position, wherein the light intensity of the stray light is greater than a preset light intensity threshold.

[0006] Optionally, the head-up display system also includes a first sensor and a second sensor, the first sensor is arranged on the propagation path of the image light from the optical waveguide to the display glass, and is used to detect the distribution of stray light sources and obtain the position information of stray light sources, and the second sensor is arranged on the propagation path of the image light from the display glass to the target observation position, and is used to detect the intensity of stray light and obtain the intensity information of stray light.

[0007] Optionally, the head-up display system also includes a light intensity processor, which is connected to the first sensor, the second sensor and the rotation drive device, and is used to receive stray light source position information and stray light intensity information transmitted by the first sensor and the second sensor, obtain the stray light intensity entering the target observation position based on the stray light source position information and the stray light intensity information, and send a first control signal to the rotation drive device, so that the rotation drive device drives the optical waveguide to rotate based on the first control signal.

[0008] Optionally, the head-up display system further includes an image source posture adjustment device, which is connected to the image source and is used to drive the image source to rotate and move so as to reduce the distortion of the image light at the target observation position.

[0009] Optionally, the head-up display system also includes a virtual image processor, which is arranged at the target observation position and is connected to the image source posture adjustment device, and is used to obtain the relative position change between the virtual image formed by the image light at the target observation position and the display glass, and send a second control signal to the image source posture adjustment device, so that the image source posture adjustment device drives the image source to rotate and move based on the second control signal.

[0010] Optionally, a spatial rectangular coordinate system is defined by the plane where the optical waveguide is located and the normal line where the rotation driving device is located, and the optical waveguide can rotate around the x-axis, y-axis or z-axis of the spatial rectangular coordinate system.

[0011] Optionally, the image source may emit image light at a variable light emission angle.

[0012] Optionally, the optical waveguide includes at least one waveguide layer, each of the waveguide layers includes an incoupling region and an outcoupling region, and the image light is coupled into the waveguide layer through the incoupling region, propagates to the outcoupling region, and is coupled out of the waveguide layer.

[0013] Optionally, the rotation driving device is connected to each waveguide layer for individually controlling the rotation of each waveguide layer.

[0014] Optionally, the waveguide layer is a volume holographic waveguide, a surface relief grating waveguide or an array waveguide.

[0015] Therefore, the present application provides a head-up display system, comprising: an image source, an optical waveguide and a display glass, wherein the image light emitted by the image source is transmitted through the optical waveguide and then emitted to the display glass, and then reflected on the display glass and emitted to the target observation position; a rotation drive device, wherein the rotation drive device is connected to the optical waveguide and used to drive the optical waveguide to rotate so that stray light cannot enter the target observation position, wherein the light intensity of the stray light is greater than a preset light intensity threshold. By setting a rotation drive device connected to the optical waveguide, the rotation drive device drives the optical waveguide to rotate, so that the optical waveguide is tilted at a certain angle to move the external stray light to the outside of the target observation position, and at this time, the light intensity of the stray light incident on the target observation position is greater than the preset light intensity threshold, thereby avoiding the stray light with a larger light intensity from entering the target observation position and affecting the virtual image effect of the image light, which can effectively eliminate the negative impact of stray light on the head-up display system and improve the image display effect of the head-up display system.

[0016] Other features and advantages of the embodiments of the present application will be described in the subsequent description, and partly become apparent from the description, or can be understood by practicing the embodiments of the present application. The purposes and other advantages of the embodiments of the present application can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram showing stray light emitted by an external light source interfering with a head-up display system is shown.

[0019] Figure 2 A schematic structural diagram of a head-up display system according to an embodiment of the present application is shown.

[0020] Figure 3 A schematic structural diagram of another head-up display system in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] In order to make those skilled in the art better understand the present application scheme, the technical scheme in the present application embodiment will be clearly and completely described below in conjunction with the drawings in the present application embodiment. Obviously, the described embodiment is only a part of the present application embodiment, rather than all the embodiments. The components of the present application embodiment usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application for protection, but merely represents the selected embodiment of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0022] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0023] See also Figure 1 , Figure 1 The schematic diagram of a head-up display system in which stray light emitted by an external light source interferes with the head-up display system is shown, wherein the head-up display system is composed of an image source 101, an optical waveguide 102 and a display glass 103. After the image light L1 emitted by the image source 101 enters the optical waveguide 102, it is coupled into the optical waveguide for pupil expansion propagation, and then coupled out from the optical waveguide and emitted to the display glass 103, thereby reflecting on the display glass 103. Figure 1 It can be seen that the sunlight L2 emitted by the external light source (such as the sun) will also enter the optical waveguide 102, and part of the light will be reflected on the optical waveguide 102, and part of the light will be diffracted on the optical waveguide 102 and coupled out after propagating in the optical waveguide, that is, a considerable part of the sunlight will be emitted from the optical waveguide 102 and reflected on the display glass 103 together with the image light L1, and then enter the human eye. It should be understood that the image observed by the user is actually the virtual image 104 formed by the image light L1 passing through the display glass 103. If the sunlight L2 entering the human eye reaches a certain light intensity, the contrast of the virtual image 104 that the user can perceive will be reduced, which will affect the display effect of the head-up display system. In more serious cases, glare will be generated, making it impossible to see the image clearly.

[0024] Therefore, please refer to Figure 2 , Figure 2The schematic diagram of the structure of a head-up display system of an embodiment of the present application is shown, and the head-up display system includes: an image source 201, an optical waveguide 202, a display glass 203, and a rotation drive device 204, wherein the image light L1 emitted by the image source 201 is transmitted through the optical waveguide 202 and then emitted to the display glass 203, and is reflected on the display glass 203 to the target observation position 205, and the rotation drive device 204 is connected to the optical waveguide 202, and is used to drive the optical waveguide 202 to rotate, so that the stray light L2 emitted by the external light source cannot enter the target observation position 205. Exemplarily, the target observation position 205 may refer to the driver's eye box, that is, the area of ​​the human eye where the driver can observe the virtual image formed by the image light.

[0025] In this embodiment, the light intensity of the stray light L2 emitted by the external light source is greater than the preset light intensity threshold. The preset light intensity threshold may be a light intensity value pre-set based on actual conditions, and when the light intensity of the stray light is greater than the value, the contrast of the virtual image of the image light observed by the driver is significantly reduced. In other words, the rotation drive device 204 drives the optical waveguide to rotate to move the stray light out of the target observation position only when the stray light intensity is high, that is, the stray light has a greater impact on the virtual image of the image light, and does not rotate the optical waveguide when the stray light has a smaller impact on the display effect, thereby avoiding the virtual image distortion problem that may be caused by the relative posture change between the optical waveguide and the display glass when the optical waveguide is rotated to change its posture, thereby ensuring a good display effect of the head-up display system.

[0026] Exemplarily, a spatial rectangular coordinate system can be defined according to the plane where the optical waveguide 202 is located and the normal where the rotating drive device 204 is located. In particular, a spatial rectangular coordinate system can be defined when the rotating drive device does not drive the optical waveguide to rotate, that is, when the optical waveguide 202 is in a horizontal state. At this time, the plane where the optical waveguide is located is the XY plane, and the normal where the rotating drive device is located is the Z axis. In addition, the rotating drive device 204 can drive the optical waveguide 202 to rotate around any one of the X axis, Y axis or Z axis of the spatial rectangular coordinate system, that is, the optical waveguide 202 can rotate around one axis, two axes or three axes in space. As an embodiment, the optical waveguide can adopt a variety of waveguide structures such as a volume holographic waveguide, a surface relief grating waveguide or an arrayed waveguide.

[0027] Therefore, the present application provides a head-up display system, which is provided with a rotating drive device connected to the optical waveguide, and when and only when the light intensity of the stray light incident on the target observation position is greater than a preset light intensity threshold, the rotating drive device drives the optical waveguide to rotate, so that the optical waveguide is tilted at a certain angle to move the external stray light to the outside of the target observation position, thereby avoiding the effect of avoiding the stray light with higher light intensity from entering the target observation position and affecting the virtual image effect of the image light, which can effectively eliminate the negative impact of the stray light on the head-up display system and improve the image display effect of the head-up display system.

[0028] As an implementation, see Figure 3 , Figure 3 A structural schematic diagram of another head-up display system in an embodiment of the present application is shown, wherein the head-up display system includes the image source 201, the optical waveguide 202, the display glass 203 and the rotation drive device 204 in the above embodiment, and the specific implementation method can refer to the above embodiment, and the head-up display system also includes a first sensor 206 and a second sensor 207, the first sensor 206 is arranged on the propagation path of the image light L1 emitted from the optical waveguide 202 to the display glass 203, and the second sensor 207 is arranged on the propagation path of the image light L1 emitted from the display glass 203 to the target observation position 205, and the first sensor 206 is used to detect the distribution of stray light sources and obtain the position information of the stray light sources, and the second sensor 207 is used to detect the intensity of the stray light and obtain the intensity information of the stray light. Furthermore, after detecting the distribution position of the stray light source, the first sensor can obtain the position coordinates of the stray light source in the coordinate system based on the spatial rectangular coordinate system determined according to the optical waveguide and the rotational drive device. At the same time, the second sensor is arranged on the propagation path of the light incident on the target observation position, and the obtained stray light intensity information can represent the stray light intensity of the incident target observation position.

[0029] Furthermore, the head-up display system also includes a light intensity processor, and the light intensity processor is connected to the first sensor, the second sensor and the rotation drive device. The light intensity processor is used to receive the stray light source position information transmitted by the first sensor, and the stray light intensity information transmitted by the second sensor, and according to the above-mentioned stray light source position information and stray light intensity information, combined with the current optical waveguide posture, target observation position and other information, calculate the stray light intensity of the incident target observation position, judge whether the stray light intensity of the incident target observation position exceeds a preset light intensity threshold, and send a first control signal to the rotation drive device when the stray light intensity of the incident target observation position exceeds the preset light intensity threshold. Further, the rotation drive device drives the optical waveguide to rotate based on the first control signal. Exemplarily, the light intensity processor can also be used to calculate the optical waveguide posture change data information required to move the stray light out of the target observation position based on the intensity of the stray light incident on the target observation position, the position information of the stray light source, and the current optical waveguide posture, and send the required optical waveguide posture change data information as the first control signal to the rotation drive device. Furthermore, the light intensity processor should also calculate the corresponding optical waveguide posture change data information when the original stray light is moved out of the target observation position and no new stray light enters the target observation position, so as to avoid new stray light entering the target observation position due to the change in the posture of the optical waveguide.

[0030] Exemplarily, the head-up display system further includes an image source posture adjustment device 208, wherein the image source posture adjustment device 208 is connected to the image source 201 and is used to drive the image source 201 to rotate or translate, so as to reduce the distortion of the image light L1 at the target observation position 205. It should be understood that since the rotation driving device changes the posture of the optical waveguide, the relative posture between the area of ​​the optical waveguide that couples out the light and the display glass is changed, thereby causing the relative position between the virtual image formed by the image light observed by the driver at the target observation position and the display glass to change, and for the head-up display system with augmented reality function, some patterns in the virtual image formed by the image light have the ability to interact with the external environment, that is, the change in the relative position between the virtual image of the image light and the display glass will affect the interaction between the virtual image pattern and the external environment. Therefore, when the posture of the optical waveguide is changed under the control of the rotational drive device, the image source posture adjustment device can be synchronously controlled to control the rotation or movement of the image source, and the relative position of the image light emitted by the image source and the optical waveguide can be changed to compensate for the change in the relative position between the virtual image of the image light and the display glass when the image light is emitted from the optical waveguide to the display glass and formed, so as to reduce the distortion of the virtual image of the image light observed at the target observation position, and further improve the display effect of the head-up display system.

[0031] Furthermore, the head-up display system also includes a virtual image processor, which is arranged at the target observation position and connected to the image source posture adjustment device. The virtual image processor is used to obtain the relative position change between the virtual image formed by the image light at the target observation position and the display glass, and in combination with the current optical waveguide posture and the target observation position and other position information, calculate the virtual image relative position change information, determine whether the virtual image relative position change information exceeds the preset distortion threshold, and send a second control signal to the image source posture adjustment device when the virtual image relative position change information exceeds the preset distortion threshold. Further, the image source posture adjustment device drives the image source to rotate and move based on the second control signal. Exemplarily, the virtual image processor can also calculate the image source posture change data information required to compensate for the virtual image distortion of the image light based on the virtual image relative position change information combined with the image source position, the optical waveguide posture and the display glass position, and send the required image source posture change data information as the second control signal to the image source posture adjustment device. Furthermore, as an implementation method, the light emitting angle of the image light emitted by the image source is variable, and the virtual image processor can calculate the image source light emitting angle information required to compensate for the virtual image distortion of the image light based on the virtual image relative position change information combined with the image source position, the optical waveguide posture and the display glass position, and send the required image source light emitting angle information to the image source as a third control signal, so that the image source changes the light emitting angle to compensate for the virtual image distortion of the image light, thereby reducing the distortion of the virtual image of the image light observed at the target observation position, and further improving the display effect of the head-up display system.

[0032] As an implementation mode, the optical waveguide includes at least one waveguide layer, and each waveguide layer includes an in-coupling region and an out-coupling region. The propagation process of the image light in the optical waveguide is specifically as follows: after the image light is coupled into the waveguide layer through the in-coupling region, it is totally reflected in the waveguide layer and propagates to the out-coupling region and is coupled out of the waveguide layer, thereby entering the next waveguide layer, and repeating the same propagation process until the light finally exits the optical waveguide. Exemplarily, the in-coupling region is used to make the light meet the total reflection condition of the waveguide, so that the light can propagate in the waveguide in the form of total reflection, and the out-coupling region is used to break the total reflection condition of the light so that the light can exit from the waveguide. Furthermore, the in-coupling region and the out-coupling region can both adopt prisms, wedge angles, arrayed optical waveguides, surface relief gratings, holographic gratings and other solutions, and the grating can adopt different solutions of transmission diffraction gratings or reflection diffraction gratings, and no limitation is imposed on the specific settings of the in-coupling region and the out-coupling region.

[0033] Furthermore, the rotation drive device is connected to each waveguide layer, and the rotation drive device can control the rotation of each waveguide layer individually. It can be understood that when stray light enters the optical waveguide from the outside, some light rays, such as image light rays, are diffracted and propagated in the waveguide layer. Therefore, the posture change of any waveguide layer in the optical waveguide can affect the propagation of the stray light incident on the target observation position. That is to say, the rotation drive device can be set to control the posture change of a single waveguide layer individually, or the rotation drive device can be set to control the posture change of multiple waveguide layers at the same time, both of which can achieve the purpose of moving the stray light out of the target observation position. For example, since most stray light sources are located outside the display glass, a large amount of light is diffracted and propagated directly in a waveguide layer close to the display glass and emitted to the display glass. At the same time, there is also some stray light that is directly reflected on the waveguide layer to the display glass. Therefore, the rotational drive device can preferentially drive the waveguide layer closer to the display glass to rotate, so as to achieve the best control effect. Without the need for complex posture solution and control operations, most of the stray light can be moved out of the target observation position through the waveguide layer close to the display glass.

[0034] Therefore, the present application provides a head-up display system, including an image source, an optical waveguide and a display glass, wherein the image light emitted by the image source is transmitted through the optical waveguide and then emitted to the display glass, and then reflected on the display glass and emitted to the target observation position; a rotation drive device, the rotation drive device is connected to the optical waveguide, and is used to drive the optical waveguide to rotate so that stray light cannot enter the target observation position, wherein the light intensity of the stray light is greater than a preset light intensity threshold. By setting a rotation drive device connected to the optical waveguide, the rotation drive device drives the optical waveguide to rotate, so that the optical waveguide is tilted at a certain angle to move the external stray light to the outside of the target observation position, and at this time, the light intensity of the stray light incident on the target observation position is greater than the preset light intensity threshold, thereby avoiding the stray light with a larger light intensity from entering the target observation position and affecting the virtual image effect of the image light, which can effectively eliminate the negative impact of stray light on the head-up display system and improve the image display effect of the head-up display system.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A head-up display system, characterized in that: include: An image source, an optical waveguide and a display glass, wherein the image light emitted by the image source is transmitted through the optical waveguide and then emitted to the display glass, and then reflected on the display glass and emitted to a target observation position; A rotation driving device is connected to the optical waveguide and is used to drive the optical waveguide to rotate so that stray light cannot enter the target observation position, wherein the light intensity of the stray light is greater than a preset light intensity threshold.

2. The head-up display system according to claim 1, characterized in that: The head-up display system also includes a first sensor and a second sensor. The first sensor is arranged on a propagation path of the image light from the optical waveguide to the display glass, and is used to detect the distribution of stray light sources and obtain the position information of the stray light sources. The second sensor is arranged on a propagation path of the image light from the display glass to the target observation position, and is used to detect the intensity of the stray light and obtain the intensity information of the stray light.

3. The head-up display system according to claim 2, characterized in that: The head-up display system also includes a light intensity processor, which is connected to the first sensor, the second sensor and the rotation drive device, and is used to receive the stray light source position information and the stray light intensity information transmitted by the first sensor and the second sensor, obtain the stray light intensity entering the target observation position based on the stray light source position information and the stray light intensity information, and send a first control signal to the rotation drive device, so that the rotation drive device drives the optical waveguide to rotate based on the first control signal.

4. The head-up display system according to claim 1, characterized in that: The head-up display system also includes an image source posture adjustment device, which is connected to the image source and is used to drive the image source to rotate or translate so as to reduce the distortion of the image light at the target observation position.

5. The head-up display system according to claim 4, characterized in that: The head-up display system also includes a virtual image processor, which is arranged at the target observation position and connected to the image source posture adjustment device, and is used to obtain the relative position change between the virtual image formed by the image light at the target observation position and the display glass, and send a second control signal to the image source posture adjustment device, so that the image source posture adjustment device drives the image source to rotate and move based on the second control signal.

6. The head-up display system according to claim 1, characterized in that: A spatial rectangular coordinate system is defined by the plane where the optical waveguide is located and the normal line where the rotation driving device is located. The optical waveguide can rotate around the x-axis, y-axis or z-axis of the spatial rectangular coordinate system.

7. The head-up display system according to claim 1, characterized in that: The image source can emit image light at a variable light emission angle.

8. The head-up display system according to claim 1, characterized in that: The optical waveguide includes at least one waveguide layer, each of which includes an incoupling region and an outcoupling region. After the image light is coupled into the waveguide layer through the incoupling region, it propagates to the outcoupling region and is coupled out of the waveguide layer.

9. The head-up display system according to claim 8, characterized in that: The rotation driving device is connected to each waveguide layer and is used to individually control the rotation of each waveguide layer.

10. The head-up display system according to claim 8, characterized in that: The waveguide layer is a volume holographic waveguide, a surface relief grating waveguide or an array waveguide.

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