CN114063292A

CN114063292A - Head-up display device, head-up display system and traffic equipment

Info

Publication number: CN114063292A
Application number: CN202010790850.1A
Authority: CN
Inventors: 方涛; 徐俊峰; 吴慧军
Original assignee: Futurus Technology Co Ltd
Current assignee: Futurus Technology Co Ltd
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2022-02-18

Abstract

The embodiment of the invention relates to the technical field of display, and discloses a head-up display device, which comprises a shell, an image source and a reflecting element, wherein the image source and the reflecting element are arranged in the shell and are sequentially arranged along a first light path; the image source comprises a backlight module, an imaging module, a waveguide element and an illumination sensor, wherein the waveguide element and the illumination sensor are sequentially arranged along a second light path; the illumination sensor is located outside the first optical path and generates a first trigger signal when the illumination intensity reaches a first preset threshold value. The invention also provides a head-up display system and traffic equipment. The head-up display equipment, the head-up display system and the traffic equipment can give out early warning in time when the image source is excessively irradiated by external light, so that corresponding protective measures can be taken subsequently to avoid the image source from being damaged.

Description

Head-up display device, head-up display system and traffic equipment

Technical Field

The embodiment of the invention relates to the technical field of display, in particular to a head-up display device, a head-up display system and a traffic device which are suitable for vehicle-mounted head-up display.

Background

The new line shows (HUD, head up display) technique indicates the optical design through the reflective, the light that sends the image source is finally projected on formation of image window (formation of image board, windshield etc.), thereby the driver is when observing the outside real environment of windshield, need not the low head just can directly see information such as speed of time, navigation, avoid the driver to look at the branch heart that panel board or control screen lead to in driving process low head, and then improve driving safety factor, also can bring better driving experience simultaneously.

The inside image source that contains the formation of image module that is equipped with of current HUD equipment, when using, the light of image source outgoing generally through the reflection system who contains reflection element such as plane mirror, curved surface speculum, final outgoing forms the virtual image to windshield reflection. Because the light path is reversible, the sunlight shines into HUD's reflection system after windshield, the sunlight after the final reflection can incide on the formation of image module in the image source, because of the intensity of sunlight is very high, consequently even only few sun ray gets into HUD's reflection system, the heat that finally reachs the image source is also many, this part heat can lead to the temperature rise of formation of image module, after the temperature rises to certain degree, the formation of image module will overheat impaired, there is the risk of burning out even, thereby lead to the image source impaired. Therefore, how to discover in time that the imaging module receives the excessive irradiation of external light to do benefit to the follow-up corresponding safeguard measure of taking and avoid the image source impaired, become the not negligible problem in the HUD equipment design process.

Disclosure of Invention

The embodiment of the invention aims to provide a head-up display device, a head-up display system and a traffic device, which can timely give out early warning when an imaging module is excessively irradiated by external light so as to be beneficial to subsequently adopting corresponding protective measures to avoid image source damage.

In order to solve the above technical problem, an embodiment of the present invention provides a head-up display device, including a housing, an image source and a reflective element, which are disposed in the housing and sequentially disposed along a first optical path, wherein the housing is provided with a light outlet on the first optical path; the image source comprises a backlight module and an imaging module which are sequentially arranged along the first light path, the backlight module is used for generating backlight and projecting the backlight to the imaging module along the first light path, the imaging module is used for receiving the backlight and generating imaging light, and the reflecting element is used for receiving the imaging light and reflecting the imaging light to the light outlet; the head-up display equipment further comprises a waveguide element and an illumination sensor which are sequentially arranged along a second light path, wherein the waveguide element is positioned on the first light path and is used for transmitting light rays from the backlight module or the imaging light rays, collecting external light rays on the first light path and sending the external light rays to the illumination sensor; the illumination sensor is located outside the first optical path and used for collecting illumination intensity of external light from the waveguide element and generating a first trigger signal when the illumination intensity reaches a first preset threshold value.

Embodiments of the present invention also provide a head-up display system including a transflective device having a reflective region, and a head-up display apparatus as described above, the head-up display apparatus being configured to project the imaging light to the reflective region along an imaging optical path to form a virtual image on one side of the transflective device.

Embodiments of the present invention also provide a transportation device, including the head-up display system as described above.

Compared with the prior art, the embodiment of the invention is characterized in that a waveguide element capable of transmitting light rays from a backlight module or imaging light rays is arranged on a first light path for transmitting the imaging light rays, the waveguide element is coupled into external light rays on the first light path, and then the coupled external light rays are sent to an illumination sensor; and the illumination sensor is arranged at a position outside the first light path, so that imaging light rays cannot be shielded, and the head-up display function can be normally realized.

In addition, in the head-up display device, the waveguide element includes an optical coupling-in portion, a light transmission portion and an optical coupling-out portion, the optical coupling-in portion is disposed in the first light path so as to couple in external light in the first light path, the light transmission portion is used for transmitting the external light coupled in by the optical coupling-in portion to the optical coupling-out portion, the optical coupling-out portion is used for coupling out from the external light of the light transmission portion and transmitting to the illumination sensor.

In addition, in the head-up display apparatus, the light incoupling part is disposed on the first light path between the backlight module and the imaging module.

In addition, in the head-up display apparatus, the light incoupling portion and the backlight module are respectively located at opposite sides of the imaging module.

In addition, in the head-up display apparatus, a diffusing element disposed on the second light path and between the waveguide element and the illumination sensor is further included.

In addition, in the head-up display apparatus, the illumination sensor may be one or more.

In addition, in the head-up display apparatus, the waveguide member may be coupled in ultraviolet light or infrared light, and the illumination sensor is an ultraviolet light sensor or an infrared light sensor.

In addition, in the head-up display apparatus, the waveguide member may couple in visible light having a wavelength band different from that of the imaging light, and the illumination sensor is a visible light sensor.

In addition, in the head-up display apparatus, the waveguide element may couple in ultraviolet light, infrared light, and visible light having a wavelength band different from that of the imaging light, and the illumination sensor may be at least one of a visible light sensor, or an ultraviolet light sensor, and an infrared light sensor.

In addition, in the head-up display apparatus, the waveguide member includes a light incoupling part for incoupling the external light, the light incoupling part including at least one of a surface grating and a volume grating.

In addition, among the new line display device, backlight unit is including the light source that is used for producing light and set gradually leaded light component, spotlight element and the diffusion element of light source light-emitting side, leaded light component is used for collecting the light that the light source produced and will collect light conduction extremely spotlight element, spotlight element is used for gathering the light that comes from leaded light component and will gather light conduction extremely the diffusion element, the diffusion element is used for the diffusion to come from spotlight element's light, and with the light conduction after the diffusion extremely imaging module.

In addition, in the head-up display device, the light guide element is a housing having a light exit opening, the light source is accommodated in the housing, the light condensing element is disposed at the light exit opening, and an inner wall surface of the housing is a light reflecting surface to reflect light generated by the light source and transmit the light to the light condensing element through the light exit opening.

In addition, the head-up display device further comprises an image source protection device which is connected with the illumination sensor and has a standby state and a protection state, wherein the image source protection device is used for working in the standby state when the illumination sensor does not generate the first trigger signal and working in the protection state when the illumination sensor generates the first trigger signal,

the image source protection device does not shield external light rays emitted to the image source in a standby state and does not change a propagation path of the external light rays emitted to the image source;

the image source protection device shields the external light incident to the image source in a protection state and/or changes the propagation path of the external light incident to the image source.

In addition, the head-up display device further comprises an illumination monitor connected with the image source protection device, the illumination monitor is used for detecting the illumination intensity of the external light rays incident to the image source and generating a second trigger signal when detecting that the illumination intensity of the external light rays incident to the image source is lower than a second preset threshold value, and the image source protection device is used for restoring to the standby state to work after the illumination monitor generates the second trigger signal.

In addition, in the head-up display device, the image source protection device includes a driver and a light shielding plate in transmission connection with the driver, the light shielding plate is disposed adjacent to at least one of the light outlet, the reflective element and the image source, and the driver is configured to drive the light shielding plate to move into the propagation path of the imaging light in the protection state to shield at least one of the light outlet, the reflective element and the image source from entering the external light towards the image source, and drive the light shielding plate to move out of the propagation path of the imaging light in the standby state without shielding the light outlet, the reflective element and the image source.

In addition, in the head-up display device, the head-up display device further comprises an illumination monitor connected with the driver, the illumination monitor is arranged outside the shell or inside the shell and is located on an imaging light propagation path between the light shielding plate and the light outlet, the illumination monitor is used for detecting the illumination intensity of the outside light and generating a second trigger signal when detecting that the illumination intensity of the outside light is lower than a second preset threshold value, and the image source protection device responds to the second trigger signal to restore the standby state.

In addition, in the head-up display apparatus, the image source protection device is a turning mechanism connected to the reflective element, the reflective element is at an initial position in a standby state, the turning mechanism is configured to drive the reflective element to turn over relative to the initial position in the protection state to change a propagation path of external light incident to the image source, and the turning mechanism is further configured to drive the reflective element to turn over back to the initial position in the standby state.

In addition, the head-up display device further comprises an illumination monitor which is arranged on the reflecting element and connected with the turnover mechanism, the illumination monitor is used for detecting the illumination intensity of the outside light in a protection state and generating a second trigger signal when detecting that the illumination intensity of the outside light is lower than a second preset threshold value, and the image source protection device responds to the second trigger signal and restores to a standby state.

In addition, the head-up display device further comprises a controller, wherein the controller is connected with the image source protection device, and the controller is used for starting timing after the image source protection device works in a protection state and controlling the image source protection device to be switched to a standby state when the timing duration reaches a preset threshold value.

In addition, the head-up display device also comprises a controller connected with the image source protection device, and a positioning device and an angular motion detection device which are respectively connected with the controller,

the positioning device is used for sensing longitude and latitude parameters of the current geographic position of the head-up display equipment,

the angular motion detection device is used for collecting the current angular motion parameters of the head-up display equipment,

the controller is used for determining the current position of the sun according to the current time and the longitude and latitude parameters, and determining the current orientation of the light outlet according to the angular motion parameters and the longitude and latitude parameters, and the controller is also used for:

and when the current position of the sun and the current orientation of the light outlet meet a first condition, controlling the image source protection device to work in a protection state, and when the current position of the sun and the current orientation of the light outlet do not meet the first condition, controlling the image source protection device to be switched to a standby state.

In addition, among the new line display device, still including setting up filter element on the first light path, filter element with backlight unit is located respectively imaging module's light-emitting side and income light side, filter element is used for transmitting imaging light, and reduce and incide to imaging module's external light.

In addition, in the head-up display device, the filter element is a semi-transmissive semi-reflective device for transmitting light and reflecting light; or

The filter element is a reflective optical device and is used for reflecting visible light rays and transmitting or absorbing infrared rays and/or ultraviolet rays; or

The light filtering element is a reflective optical device and is used for reflecting light rays with a first polarization state and transmitting or absorbing light rays with a second polarization state; or

The filter element is a reflective optical device and is used for reflecting visible light rays with a predetermined waveband of a first polarization state and transmitting or absorbing other rays except the visible light ray waveband of the predetermined waveband in the external light rays.

In addition, in the head-up display apparatus, the filter element is a transmissive optical device for transmitting visible light rays and for reflecting or absorbing infrared rays and/or ultraviolet rays; or

The filter element is a transmission type optical device and is used for transmitting light rays with a first polarization state and reflecting or absorbing light rays with a second polarization state; or

The filter element is a transmission type optical device and is used for transmitting visible light rays with a predetermined waveband of a first polarization state and reflecting or absorbing other light rays except the visible light ray waveband of the predetermined waveband in the external light rays.

In addition, in the head-up display system, a phase delay element is further included, which is disposed on the imaging optical path, and the imaging light includes S-polarized light.

In addition, in the head-up display system, a P-polarized reflective film is disposed on the reflective region, and the imaging light includes P-polarized light.

In addition, in the head-up display system, a virtual image of the image source via the reflective element is located at a focal plane of the transflective device.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Fig. 1 is a schematic structural view of a head-up display device according to a first embodiment of the present invention;

fig. 2 is a schematic configuration diagram of a head-up display apparatus having a plane mirror according to a first embodiment of the present invention;

fig. 3 is a schematic view of a waveguide element structure of a head-up display device according to a first embodiment of the present invention;

fig. 4 is a schematic configuration diagram of another head-up display apparatus according to the first embodiment of the present invention;

fig. 5 is a schematic structural diagram of still another head-up display device according to a first embodiment of the present invention;

FIG. 6 is a schematic diagram of a backlight module of an image source of a head-up display device according to a first embodiment of the invention;

FIG. 7 is a schematic view of a light guide element of the backlight module shown in FIG. 6;

FIG. 8 is a schematic view of a frustum-shaped light-guiding element according to a first embodiment of the present invention;

FIG. 9 is a schematic view of another light guide element according to the first embodiment of the present invention;

FIG. 10 is a schematic view of a light guide element according to the first embodiment of the present invention;

fig. 11 is a schematic structural view of still another head-up display device according to the first embodiment of the present invention;

fig. 12 is a schematic configuration diagram of a head-up display apparatus according to a second embodiment of the present invention;

fig. 13 is a schematic configuration diagram of a head-up display apparatus according to a third embodiment of the present invention;

fig. 14 is a schematic configuration diagram of a head-up display apparatus according to a fourth embodiment of the present invention;

fig. 15 is a schematic configuration diagram of another head-up display apparatus according to a fourth embodiment of the present invention;

fig. 16 is a schematic view of a head-up display system according to a fifth embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.

The invention relates to a head-up display device, which comprises a shell, an image source and a reflecting element, wherein the image source and the reflecting element are arranged in the shell and are sequentially arranged along a first light path; the image source comprises a backlight module and an imaging module which are sequentially arranged along the first light path, the backlight module is used for generating backlight and projecting the backlight to the imaging module along the first light path, the imaging module is used for receiving the backlight and generating imaging light, and the reflecting element is used for receiving the imaging light and reflecting the imaging light to the light outlet; the head-up display equipment further comprises a waveguide element and an illumination sensor which are sequentially arranged along a second light path, wherein the waveguide element is positioned on the first light path and is used for transmitting light rays from the backlight module or the imaging light rays, collecting external light rays on the first light path and sending the external light rays to the illumination sensor; the illumination sensor is located outside the first optical path and used for collecting illumination intensity of external light from the waveguide element and generating a first trigger signal when the illumination intensity reaches a first preset threshold value. The core of the embodiment is that a waveguide element capable of transmitting light rays from a backlight module or imaging light rays is arranged on a first light path for transmitting the imaging light rays, the waveguide element is coupled into external light rays on the first light path, and then the coupled external light rays are sent to an illumination sensor; and the illumination sensor is arranged at a position outside the first light path, so that imaging light rays cannot be shielded, and the head-up display function can be normally realized. The following describes the implementation details of the image source of the present embodiment in detail, and the following is provided only for the convenience of understanding and is not necessary for implementing the present embodiment.

Referring to fig. 1, a head-up display apparatus 10 according to a first embodiment of the present invention includes a housing 11, a backlight 12, an imaging module 13, a reflective element 14, a waveguide 15, and an illumination sensor 16.

The housing 11 is a housing of the whole head-up display device 10, and is used for accommodating the backlight module 12, the imaging module 13, the reflecting element 14, the waveguide element 15, and the illumination sensor 16 for protection, and the housing 11 is provided with a light outlet 110 for emitting imaging light.

The backlight module 12 is used for generating backlight and has a light emitting side facing the imaging module 13, so that the backlight module 12 provides backlight for the imaging module 13, and the backlight module 12 and the imaging module 13 together form an image source of the head-up display device. The backlight module 12 includes at least one electroluminescent element, and is excited by an electric Field to generate Light, such as a Light Emitting Diode (LED), an Organic Light Emitting Diode (OLED), a Mini LED (Mini LED), a Micro LED (Micro LED), a Cold Cathode Fluorescent Lamp (CCFL), a Cold Light source (CLL), an Electro Luminescence (EL), an electron Emission (FED), or a Quantum Dot Light source (QD).

The imaging module 13 is disposed on the light emitting side of the backlight module 12, and receives the backlight and generates imaging light. The imaging module 13 includes, but is not limited to, a liquid crystal display module, which may include a liquid crystal layer and a polarization element disposed on the upper and lower surfaces of the liquid crystal layer and having mutually orthogonal polarization directions, and the light emitted from the backlight module 12 is converted into an imaging light for forming vehicle-related information images such as speed per hour, navigation, etc. through the imaging module 13, and is projected to the reflection element 14.

The reflecting element 14 receives the imaging light from the imaging module 13 and reflects the imaging light toward the light outlet 110 to project on an external device (such as a windshield of an automobile) to form an image for human eyes to observe, and the imaging light propagates in the whole display process as shown by a solid line with an arrow in fig. 1. In this embodiment, the reflective element 14 is a curved mirror, which can magnify the image and provide a longer imaging distance. Therefore, a first light path from the backlight module 12 to the imaging module 13, then to the reflective element 14, and then to the light outlet 110 is formed in the housing 11, and the backlight generated by the backlight module 12 passes through the imaging module 13 along the first light path and forms an image, then reaches the reflective element 14 along the first light path, is reflected by the reflective element 14, then is transmitted to the light outlet 110 of the housing 11 along the first light path, and is projected onto an external imaging device (such as a windshield of an automobile) to be reflected, so as to form a virtual image for viewing.

It should be noted that the number of the reflective elements 14 in the head-up display device 10 is not limited to one, and may be two or more. Referring to fig. 2, a plane mirror 14 'may be further disposed on the optical path between the reflective element 14 and the imaging module 13, so that the volume of the head-up display device 10 may be reduced by disposing the plane mirror 14', and the space utilization may be improved. Therefore, the backlight module 12, the imaging module 13, the reflective element 14, the plane mirror 14 'and the light outlet 110 of the housing 11 together form a first light path for transmitting light required for head-up display, and the light from the backlight module 12 sequentially passes through the imaging module 13, the reflective element 14, the plane mirror 14' and the light outlet 110 of the housing 11 along the first light path, and is finally reflected on an external imaging device (such as a windshield of an automobile) to form a virtual image for viewing.

The waveguide element 15 may be a surface grating waveguide or a volume holographic waveguide, and is located on the first light path, and is configured to transmit light from the backlight module 12, collect external light on the first light path, and transmit the external light to the illumination sensor 16. Specifically, as shown in fig. 3, in the present embodiment, the waveguide element includes a light incoupling portion 150, a light-transmitting portion 151, and a light outcoupling portion 152.

The light incoupling part 150 is disposed in the first optical path to couple in external light in the first optical path, and the light incoupling part 150 specifically includes at least one of a surface grating and a bulk grating, and may be a transmissive or reflective type. The light transmitting part 151 is used for transmitting the external light coupled in by the light coupling-in part 150 to the light coupling-out part 152 in a total reflection manner, and the light transmitting part 151 is made of a transparent material with a refractive index greater than 1. The light out-coupling portion 152 is configured to couple out the external light from the light transmission portion 151 and transmit the external light to the illumination sensor 16, and the light out-coupling portion 152 includes at least one of a surface grating, a volume grating, and a reflector, and may be a transmissive type or a reflective type. The arrangement is such that the light with the wavelength and/or light angle corresponding to the light in-coupling portion 150 and the light out-coupling portion 151 is transmitted and coupled out from the incoupling waveguide 15.

In the present embodiment, the waveguide element 15 is disposed on the first optical path between the backlight module 12 and the imaging module 13. Furthermore, in order to ensure that the external light is coupled in as much as possible to improve the prediction accuracy, in an implementation preference, the light incoupling portion 150 of the waveguide element 15 may be disposed on the first light path between the backlight module 12 and the imaging module 13, and the light conducting portion 151 and the light outcoupling portion 152 of the waveguide element 15 may be located outside the first light path, as shown in fig. 4.

The illumination sensor 16 is located outside the first optical path, and is configured to collect illumination intensity of external light from the waveguide element 15, and generate a first trigger signal when the illumination intensity reaches a first preset threshold. With such an arrangement, after the external light is coupled out from the light out-coupling portion 152 of the waveguide element 15, the external light propagates to the illumination sensor 16 along the second light path from the light out-coupling portion 152 to the illumination sensor 16, so as to utilize the illumination sensor 16 to sense the illumination intensity of the external light, and determine whether the intensity can cause the imaging module 13 to be excessively heated and cause damage to the image source.

Since the external light that may cause high intensity irradiation to damage the light source is sunlight, and the radiation band of the sunlight mainly includes ultraviolet light, visible light, and infrared light, and the imaging light is generally visible light, in order to sense the illumination intensity of the sunlight, in this embodiment, the waveguide element 15 may be a waveguide device that can couple in the infrared light, the ultraviolet light, and the visible light emitted by the non-backlight module 12, so as to couple in at least one of the infrared light, the ultraviolet light, and the visible light emitted by the non-backlight module 12, and transmit the coupled light to the illumination sensor 16 to sense the illumination intensity of the sunlight. Because the waveguide element 15 will not couple into the visible light emitted from the backlight module 12, for the light emitted from the backlight module 12 or the imaging light formed by the imaging module 13, the waveguide element 15 is transparent and will not affect the normal propagation of the light required for the head-up display, and will not block the light path and affect the imaging.

The illumination sensor 16 includes, but is not limited to, at least one of a visible light sensor, an ultraviolet light sensor, and an infrared light sensor. In particular, the type of the light sensor 16 may be selected according to the wavelength band to which the light coupled into the waveguide element 15 belongs, for example:

1. if the waveguide element 15 can be coupled in ultraviolet light and/or, correspondingly, the illumination sensor 16 can be an ultraviolet light sensor and/or an infrared sensor;

the backlight module 12 emits a normal white light (white light generated by exciting the phosphor with blue light) or a RGB mixed white light without infrared light and ultraviolet light. After entering the head-up display device 10, the sunlight is transmitted to the imaging module 13 through the reflection element 14, and then reaches the waveguide element 15 through the imaging module 13; infrared light and/or ultraviolet light in sunlight enters the waveguide element 15 through the light incoupling part 150, is transmitted to the light outcoupling part 152 in the light conduction part 151 in a total reflection manner, is then transmitted out of the waveguide element 15, and reaches the illumination sensor 16 (an infrared light sensing device and/or an ultraviolet light sensing device) on the second light path, and after the light intensity reaches a first preset threshold value, the illumination sensor 16 sends out a first trigger signal. Meanwhile, for the backlight module 12, the emitted common white light (white light generated by the blue light excited phosphor) or the RGB mixed white light is not coupled into the waveguide device 15, and can smoothly pass through the waveguide device 15 without affecting the image formation.

2. If the waveguide element 15 can couple in visible light of a different wavelength band than the imaging light, the illumination sensor 16 can accordingly be a visible light sensor;

the backlight module 12 emits RGB mixed white light without infrared light and ultraviolet light. After entering the head-up display device 10, the sunlight is transmitted to the imaging module 13 through the reflection element 14, and then reaches the waveguide element 15 through the imaging module 13; visible light in sunlight except for the RGB specific wavelength band enters the waveguide element 15 through the light incoupling part 150, is transmitted to the light outcoupling part 152 in the light conduction part 151 in a total reflection manner, is then transmitted out of the waveguide element 15, reaches the illumination sensor 16 on the second light path, and the illumination sensor 16 sends out a first trigger signal after the light intensity reaches a first preset threshold value. Specifically, the RGB mixed white light comprises three RGB wave bands, wherein the central point of the first wave band is located between 410nm and 480nm, the central point of the second wave band is located between 500nm and 565nm, the central point of the third wave band is located between 590nm and 690nm, and the peak widths of the three wave bands are less than or equal to 50 nm. Meanwhile, for the backlight module 12, the emitted RGB mixed white light is not coupled into the waveguide device 15, and can smoothly pass through the waveguide device 15 without affecting the image formation.

3. If the waveguide member 15 can couple in ultraviolet light, infrared light, and visible light different from the imaging light band, the illumination sensor 16 is at least one of a visible light sensor (for sensing the illumination intensity of visible light different from the imaging light band), an ultraviolet light sensor, and an infrared light sensor, accordingly.

In the operation of the head-up display device 10, since the optical path is reversible, in a situation where "the imaging light emitted by the imaging module 13 can be emitted to the outside of the housing 11 under the action of the reflective element 14", the light from the sun (i.e. the external light) outside the housing 111 will also be emitted into the housing 11 of the head-up display device 10 through the light outlet 110 and reversely emitted onto the imaging module 13 along the propagation path (i.e. the first optical path) of the imaging light, thereby causing the temperature of the image source to increase. When the external light is emitted to the imaging module 13 along the first light path in a reverse direction (indicated by a dotted line with an arrow in fig. 1), the external light transmits through the imaging module 13 and reaches the waveguide element 15, then is coupled into the waveguide element 15 and is guided to the illumination sensor 16, the illumination sensor 16 senses the received illumination intensity, and generates a trigger signal as an early warning when the illumination intensity exceeds a first preset threshold, so that corresponding protective measures can be taken subsequently to prevent the imaging module 13 from being damaged due to over-illumination. The corresponding protection measures may be to correspondingly display warning characters, images and the like by using the head-up display device 10 to prompt the driver: a. the backlight module 12 and the imaging module 13 are closed to reduce the heat generated by the work of the image source, so as to reduce the temperature of the image source to a certain extent; shielding external light incident on the imaging module 13 with a tool, or turning on a device (such as an on-board air conditioner) for providing cooling effect to the image source, etc., which are not listed herein. In addition, because the illumination sensor 16 is located outside the first light path, the light emitted by the backlight module 12 is not shielded, and the display function of the HUD device is prevented from being affected.

It can be understood that the number of the illumination sensors 16 may be one or more, and the plurality of illumination sensors 16 may ensure accurate detection of sunlight as much as possible, thereby improving the early warning accuracy. In addition, although the waveguide element 15 is shown in fig. 1 to be located on a side of the imaging module 13 adjacent to the backlight module 12, in other embodiments, the waveguide element 15 may also be located on a side of the imaging module 13 away from the backlight module 12. For example, the waveguide member 15 is provided on the first optical path between the imaging block 13 and the reflecting member 14 (shown in fig. 5), or the waveguide member 15 is provided on the first optical path between the reflecting member 14 and the light outlet 110, or the like. In order to ensure that the external light is coupled in as much as possible to improve the prediction accuracy, in a preferred embodiment of the modified embodiment, only the light coupling-in portion 150 may be disposed on the first light path between the imaging module 13 and the reflective element 14 or between the reflective element 14 and the light outlet 110, so that the light coupling-in portion 150 and the backlight module 12 are respectively disposed on two opposite sides of the imaging module 13. When the external light is emitted to the imaging module 13 along the first light path in a reverse direction (indicated by a dotted line with an arrow in fig. 1), the external light first reaches the waveguide element 15, then is coupled into the waveguide element 15 and is transmitted to the illumination sensor 16, the illumination sensor 16 senses the received illumination intensity, and generates a trigger signal as an early warning when the illumination intensity exceeds a first preset threshold value, so that corresponding protection measures are taken subsequently to prevent the imaging module 13 from being damaged due to over-irradiation.

It should be noted that the backlight module 12 may include a light source 120, a light guide element 122, a light condensing element 124 and a dispersing element 126, as shown in fig. 6.

The Light source 120 is used for generating Light, and may include at least one electroluminescent element, which generates Light by electric Field excitation, such as a Light Emitting Diode (LED), an Organic Light Emitting Diode (OLED), a Mini LED (Mini LED), a Micro LED (Micro LED), a Cold Cathode Fluorescent Lamp (CCFL), a Cold Light source (Cold LED Light, CLL), an Electroluminescence (EL), an electron Emission (FED), or a Quantum Dot Light source (QD).

The light guide element 122 is disposed on the light emitting side of the light source 120, and is used for collecting the light generated by the light source 120 and transmitting the collected light to the light condensing element 124. Referring to fig. 7, in the present embodiment, the light guide element 122 is a casing having a light exit opening 1220, the light source 120 is accommodated in a bottom 1221 of the casing, and the bottom 1221 may be an opening; the inner wall 1222 of the housing is a light reflecting surface to reflect the light generated by the light source 120, and the light emitted by the light source 120 propagates in the light guide element 122 and then exits to the light condensing element 124 through the light exit opening 1220.

It is understood that the light beam generated by the light source 120 has a divergence angle (the maximum included angle between the normal line at the center of the light source 120 and the emergent light ray), and therefore, the light rays emitted from the light source 120 are emitted toward various directions within the divergence angle at a plurality of angles (the angle between the normal line at the center of the light source 120 and the emergent light ray), wherein the small-angle light rays (the included angle with the normal line at the center of the light source 120 is small, such as 10 degrees, 15 degrees, 20 degrees, etc., hereinafter referred to as small-angle light rays) are directly transmitted from the light source 120 to the light outlet opening 1220 to be emitted, and the large-angle light rays (the included angle with the normal line at the center of the light source 120 is large, such as 30 degrees, 45 degrees, 60 degrees, etc., hereinafter referred to as large-angle light rays) are emitted from the light source 120 to the inner wall surface 1222. Because inner wall 1222 is a light reflecting surface, the wide angle light emitted by light source 120 will be gathered after being reflected by inner wall 1222, thereby improving the utilization rate of the light source. The light guide element 122 may have a triangular pyramid frustum shape, a rectangular pyramid frustum shape, or a frustum shape (similar to a bowl shape) with a paraboloid as a side surface. In this embodiment, the light guide element 122 has a shape of a truncated pyramid, and the light outlet 1220 and the bottom 1221 may have the same shape or different shapes, and include at least one of a rectangle, a square, a trapezoid, or a parallelogram, as shown in fig. 8.

The light condensing element 124 is disposed on the light emitting side of the light guiding element 122 at the light emitting opening 1220, and is used for condensing the light from the light guiding element 122 and conducting the condensed light to the dispersing element 126. Specifically, the light condensing element 124 controls the direction of the light emitted from the light guiding element 122, so as to condense the light to a predetermined range, thereby further condensing the light and improving the utilization rate of the light. The light-gathering element 124 may be a lens or a lens combination, such as a convex lens, a fresnel lens or a lens combination, and in the present embodiment, the light-gathering element 124 is a convex lens. It is understood that the predetermined range may be a point, such as a focal point of a convex lens, or a smaller area, and the condensing element 124 is disposed to condense the high-angle light emitted from the light source 120, so as to improve the light utilization rate.

The dispersing element 126 is disposed on the light-emitting side of the light guide element 124, and is used for dispersing the light from the light-gathering element 124 and conducting the dispersed light to the imaging module 13. In particular, diffusion element 126 diffuses light into a beam having a distribution angle, the smaller the diffusion angle, the higher the brightness of the beam, and vice versa. The diffusion element 126 diffuses the gathered light at a certain angle, so that the diffusion degree of the light is increased, and the light can be uniformly distributed in a certain area. The dispersing element 126 may be a diffractive optical element, such as a beam shaper (beam shaper), and after passing through the dispersing element 126, the light is dispersed and forms a beam with a specific cross-sectional shape, including but not limited to a line, a circle, an ellipse, a square, or a rectangle. By controlling the microstructure of the dispersion element 126, the dispersion angle, the cross-sectional shape, and the like of the light can be precisely controlled, and the dispersion effect can be precisely controlled.

It should be noted that the light guide element 122 is not limited to the aforementioned housing structure, and may be of other structures. For example, as shown in fig. 9, the light guide element 122 is a solid light-transmitting member, has a refractive index greater than 1, and includes a light-emitting surface 1220, a light-reflecting surface 1222, and a light source accommodating groove 1224. The light-emitting surface 1220 is adjacent to the light-condensing element 124, the light-reflecting surface 1222 extends from the periphery of the light-emitting surface 1220 towards a direction away from the light-condensing element 124 (not shown) (i.e., towards the right direction in the drawing of fig. 9), and the light-source accommodating groove 1224 is located on a side of the light-reflecting surface 1222 away from the light-emitting surface 1220 and is recessed from the edge of the light-reflecting surface 1222 on the side towards a side close to the light-emitting surface 1220. The light source accommodating groove 1224 includes a bottom wall 1224a disposed opposite to the light emitting surface 1220, and a sidewall 1224b connecting the periphery of the bottom wall 1224a to the light reflecting surface 1222, wherein the bottom wall 1224a and the sidewall 1224b are both light incident surfaces of the light guiding element 122. Thus, the light source 120 is disposed in the light source accommodating groove 1224 and faces the bottom wall 1224a of the light source accommodating groove 1224. The bottom wall 1224a is a convex surface protruding away from the light exit surface 1220, and the convex surface is used for receiving the light emitted from the light source 120 and converting the light into collimated light when the light is incident through the convex surface. The collimated light refers to light with a small or almost 0 divergence angle, which is parallel or almost parallel, and when the collimated light is incident to the liquid crystal module, the uniformity of the light is better, which is more beneficial to light conversion and imaging. In this embodiment, it is preferable that the bottom wall 1224a converts the incident light into collimated light, and the collimated light is perpendicular to the light exit surface 1220. Of course, it is understood that the light incident through the bottom wall 1224a is not necessarily perpendicular to the light emitting surface 1220 after being converted into the collimated light, and may also have a specific angle (between 0 degree and 90 degrees) with the light emitting surface 1220 based on specific considerations. It should be noted that the light reflecting surface 1222 is an inner surface of the light guiding element 122, since the refractive index of the light guiding element 122 is greater than 1, after the high-angle light emitted from the light source 120 is incident on the light reflecting surface 1222 via the sidewall 1224b, the light satisfying the total reflection condition is totally reflected on the light reflecting surface 1222 of the light guiding element 122 and exits via the light exiting surface 1220, and the low-angle light emitted from the light source 120 is incident into the light guiding element 122 via the bottom wall 1224a but not incident on the light reflecting surface 1222, but directly enters the light exiting surface 1220 and exits via the light exiting surface 1220.

It should be noted that, in the present embodiment, the bottom wall 1224a is set to be a convex surface, so that a plano-convex lens structure is formed by the convex bottom wall 1224a (the plane is a dotted line on the left side of the bottom wall 1224a shown in fig. 9, and the convex surface is the bottom wall 1224a), which has a function of adjusting a small-angle light ray strip into a collimated light ray, in fig. 9, a plano-convex lens formed by a convex surface is merely illustrated as an example, but in other modified embodiments, such a convex surface may also be used to form a collimating lens having a light ray collimating function, such as a convex lens, a fresnel lens, a lens combination, or the like, and the convex surface may be separately set and mounted on the solid light-transmitting member, or may be integrally formed with the solid light-transmitting member.

The light-reflecting surface 1222 has a curved surface shape, such as a parabolic shape, a free-form surface shape, or a conic surface shape, so as to effectively increase the incident angle of the high-angle light to the light-reflecting surface 1222, thereby more easily satisfying the critical condition of total reflection for light propagation, and ensuring that as much light as possible is reflected by the light-reflecting surface 1222 to the light-emitting surface 1220 for exiting, thereby improving the light utilization efficiency. The bottom wall of the light source housing groove 1224 is not limited to the convex structure described above, and may have other structures as long as "converting the incident light into collimated light and emitting the collimated light out of the light guide element 122" is ensured. For example, as shown in fig. 10, the light emitting surface 1220 is provided with a blind hole 1226 recessed toward the bottom wall 1224a, a bottom surface 1226a of the blind hole 1226 is a convex surface protruding toward one side of the light emitting surface 1220, the convex surface is used for emitting light incident through the bottom wall 1224a and converting the light into collimated light when the light exits through the convex surface, and the specific implementation of the convex surface is similar to the convex surface of the bottom wall 1224a in the above embodiments, and will not be described herein again. With this arrangement, the bottom wall 1224a is a plane parallel to the light exit surface 1220, but there are many other possibilities for designing the shape of the bottom wall 1224a, and the details thereof are not repeated herein.

Preferably, the head-up display device 10 may be additionally provided with a diffusing element 17. As shown in fig. 11, the head-up display apparatus 10 includes a housing 11, and a backlight 12, an imaging module 13, a reflection element 14, a waveguide element 15, a light sensor 16, and a diffusion element 17 provided in the housing 11.

The diffusing element 17 is arranged on the second optical path and between the waveguide element 15 and the illumination sensor 16. Since the diffusing member 17 can diffuse the light coupled out by the waveguide member 15, the number of the light sensors 16 can be reduced by providing the diffusing member 17, and a smaller number of the light sensors 16 can achieve a better warning effect. In the present embodiment, the diffusing element 17 may include at least one of a scattering optical element or a diffractive optical element so as to diffuse the light coupled out of the waveguide element 15 by a scattering/diffraction action.

A second embodiment of the present invention relates to another head up display device 20, and the structure of the head up display device 20 is substantially the same as the head up display device 10 provided in the first embodiment, except that the head up display device 20 provided in the second embodiment additionally includes an image source protection device, compared to the head up display device 10 of the first embodiment.

Specifically, referring to fig. 12, the head-up display device 20 includes a housing 11, a backlight module 12, an imaging module 13, a reflective element 14, a waveguide element 15, a light sensor 16, and an image source protection device 23. The backlight module 12, the imaging module 13, the reflecting element 14, the waveguide element 15 and the illumination sensor 16 are all disposed in the housing 11, and the image source protection device 23 is disposed adjacent to the light outlet 110 of the housing 11. Specifically, the image source protecting device 23 includes a driver 232 disposed on the housing 11 (which may be located inside the housing 11 or outside the housing 11), and a light shielding plate 231 in transmission connection with the driver 232, wherein the light shielding plate 231 is adjacent to the light outlet 110, and the driver 232 is in communication connection or electrical connection with the light sensor 16. The image source protection device 23 operates in a standby state when the illumination sensor 16 does not generate the first trigger signal, and operates in a protection state when the illumination sensor 16 generates the first trigger signal, wherein:

1. when the image source protection device 23 works in a standby state, the driver 232 is not started, and the light shielding plate 231 is adjacent to but does not shield the light outlet 110, so that the imaging light generated by the imaging module 13 can be smoothly emitted from the light outlet 110 after being reflected by the reflecting element 14, and a head-up display function is achieved;

2. when the image source protection device 23 works in a protection state, the driver 232 starts in response to the first trigger signal to drive the light shielding plate 231 to move to the light outlet 110 and shield the light outlet 110, so as to prevent the image source (the backlight module 12 and the imaging module 13) from being damaged due to the continuous high-intensity irradiation of the imaging module 13 by the external light;

3. the image source protection device 23 can also be switched (for example, manually) to operate in the standby state, and at this time, the image source protection device 23 returns to the standby state to operate, and the driver 232 starts again and drives the light shielding plate 231 to move away from the light exit 110, so as to ensure that the imaging light can exit through the light exit 110 to achieve the head-up display function.

It should be noted that, in specific implementation details, the driver 232 may be a power device such as a motor with a power output shaft, and the light shielding plate 231 may be in transmission connection with the power output shaft of the driver 232 through a transmission gear (not shown) so as to reciprocate under the driving of the driver 232; the light shielding plate 231 may include a light shielding arm and a transmission arm (not shown), and a transmission rack (not shown) may be disposed at an outer end of the transmission arm to be in transmission connection with the transmission gear, and the transmission gear may drive the rack to translate when rotating, so as to achieve the reciprocating movement of the light shielding plate 231.

It should be noted that, in the foregoing solution, the image source protection device 23 is disposed at a position adjacent to the light outlet 110, so as to shield the light outlet 110 in the protection state and open (i.e., not shield) the light outlet 110 in the standby state, thereby implementing switching between the off state and the normal operation of the head-up display to avoid the image source from being damaged. In other embodiments, the image source protection device 23 may be disposed adjacent to the light exit 110, such as at the reflective element 14, for shielding the reflective element 14 in the protection state and opening the reflective element 14 in the standby state; or the light shielding plate is disposed at the light emitting surface of the imaging module 13, and shields the imaging module 13 in a protection state, and opens the imaging module 13 in a standby state, so that the light shielding plate 231 is adjacent to but does not block the propagation path of the imaging light in the standby state, thereby:

1. when the image source protection device 23 enters a protection state to work, the driver 232 drives the light shielding plate 231 to move into the propagation path of the imaging light and block the propagation path so as to shield the external light reversely propagated along the propagation path;

2. when the image source protection device 23 is switched back to the standby state, the driver 232 drives the light shielding plate 231 to move out of the transmission path of the imaging light, so as to avoid blocking the imaging light and achieve the head-up display function.

Preferably, the head-up display apparatus 20 may further be additionally provided with an illumination monitor 24 connected to the image source protection device 23, and configured to detect an illumination intensity of the external light incident on the imaging module 13, and generate a second trigger signal when detecting that the illumination intensity of the external light incident on the imaging module 13 is lower than a second preset threshold, and the image source protection device 23 returns to the standby state after the illumination monitor 24 generates the second trigger signal. Thereby realizing the automatic switching of the working state of the image source protection device 23. It will be appreciated that the connection between the image source protection device 23 and the illumination monitor 24 may be a wireless connection or a wired connection. It is to be noted that, when the light shielding plate of the image source protecting device 23 is provided at the light exit 110 to shield or open the light exit, the illumination monitor 24 may be provided outside the housing 11; when the image source protection device 23 is disposed at another position on the first optical path, the illumination monitor 24 may be disposed outside the housing 11, specifically outside the light outlet 110; it may be disposed inside the housing 11 on the imaging light propagation path between the image source protection device 23 (such as a light shielding plate) and the light outlet 110, and in this embodiment, it may be disposed on the surface of the light shielding plate 231 facing the external light.

It should be noted that the illumination monitor 24 may also be replaced by a controller with a timing function, which is connected (wired or wirelessly) to the image source protection device 23, and the controller may start timing after the image source protection device 23 operates in the protection state and control the image source protection device 23 to switch to the standby state when the timing duration reaches a preset threshold. In this way, the illumination monitor 24 is not required to monitor the illumination intensity of the ambient light in real time, and instead, the display function of the image source is attempted to be enabled again after a predetermined period of time has elapsed. If the external illumination intensity is still too strong after the device is started again, the illumination sensor 16 will generate the first trigger signal again, so that the image source protection device 23 enters the protection state again for image source protection; if the ambient light intensity is no longer too strong after re-enabling, the image source may continue to operate normally.

It is understood that the illumination monitor 24 may be replaced by a controller connected (wired or wirelessly) to the image source protection device 23, and a positioning device and an angular motion detection device (not shown) respectively connected to the controller, the positioning device being configured to sense a longitude and latitude parameter of a current geographic position of the head-up display device, the angular motion detection device being configured to acquire a current angular motion parameter of the head-up display device, and the controller being configured to determine a current position of the sun according to a current time and the longitude and latitude parameter, and determine a current orientation of the light outlet 110 according to the angular motion parameter and the longitude and latitude parameter. So that:

when the current position of the sun and the current orientation of the light outlet satisfy a first condition (that is, under the current orientation of the light outlet 110, sunlight can enter the light outlet 110 and enter the image source), controlling the image source protection device 23 to maintain the protection state to work;

when the current position of the sun and the current orientation of the light outlet do not satisfy the first condition (that is, under the current orientation of the light outlet 110, the sunlight cannot enter the light outlet 110 and enters the image source), the image source protection device is controlled to switch to the standby state.

It is obvious from the above solution that the image source protection device 23 can be disposed at the light exit 110, near at least one of the reflective element 14 or the image source to implement the image source protection function, or disposed at other positions on the first optical path to implement the image source protection function, and both ways are to protect the image source by "shielding external light".

A third embodiment of the present invention relates to a head-up display device using "changing a propagation path of external light" as a measure, which has a structure substantially the same as the head-up display device 10 provided in the first embodiment, except that the head-up display device provided in the third embodiment additionally includes an image source protection device, compared to the head-up display device 10 provided in the first embodiment.

Specifically, referring to fig. 13, the head-up display device 30 includes a housing 11, a backlight module 12, an imaging module 13, a reflective element 14, a waveguide element 15, a light sensor 16, and an image source protection device 33. The backlight module 12, the imaging module 13, the reflecting element 14, the waveguide element 15, the illumination sensor 16 and the image source protection device 33 are all disposed in the housing 11. The image source protection device 33 operates in a standby state before the illumination sensor 16 generates the first trigger signal, and operates in a protection state when the illumination sensor 16 generates the first trigger signal, wherein:

the image source protection device 33 is a tilting mechanism connected to the reflective element 14 (which can be disposed at the side or back of the reflective element 14), the reflective element 14 is at an initial position in a standby state, the tilting mechanism is further configured to drive the reflective element to tilt back to the initial position in the standby state,

1. when the device works in the protection state, the image source protection device 33 responds to the first trigger signal to drive the reflection element 14 to turn over relative to the initial position so as to change the propagation path of the external light incident to the imaging module 13, so that the external light is turned to the direction which cannot irradiate the imaging module 13, the external light is prevented from reaching the imaging module 13 along the original propagation path, and the image source is prevented from being damaged;

when the imaging module 13 is switched to the standby mode, the image source protection device 33 drives the reflection element 14 to turn back to the initial position, so that the imaging light generated by the imaging module 13 can exit smoothly along the original propagation path, thereby achieving the head-up display function.

It should be noted that, in specific implementation details, the flip structure specifically includes: the reflecting element comprises a bottom plate provided with a rotating shaft, a transmission gear and a power device (not shown), wherein the bottom plate is fixed on the back or the side surface of the reflecting element, an output shaft of the power device is fixedly connected with the center of the transmission gear, one end of the rotating shaft is provided with a gear and is in transmission connection with the transmission gear, and the transmission gear can drive the rotating shaft to rotate when rotating. When the shading signal is received, the bottom plate rotates along the rotating shaft to drive the reflecting element to rotate. It is understood that the image source protection device 33 as an inverting structure may also be configured to be connected to the image source formed by the "imaging module 13 and the backlight module 12", so as to invert the image source when the intensity of the external light is too high, so that the image source is kept away from the high-intensity illumination of the external light.

Preferably, the head-up display device 30 may further include an illumination monitor 24 disposed on the reflective element 14 and connected (wired or wirelessly) to the image source protection device 33, the illumination monitor 24 is configured to detect the illumination intensity of the external light in the protection state and generate a second trigger signal when detecting that the illumination intensity of the external light is lower than a second preset threshold, and the image source protection device 33 returns to the standby state in response to the second trigger signal. It should be noted that the illumination monitor 24 may be disposed on the back surface of the reflective element 14 (another surface opposite to the reflective surface of the reflective element 14), or on other surfaces of the reflective element 14 except the reflective surface, as long as it is ensured that the illumination monitor 24 can receive the external light entering the housing 11 through the light outlet of the housing 11 after the "image source protection device 33 drives the reflective element 14 to turn over" (i.e. in the protection state).

It should be added that the foregoing embodiments can achieve timely warning, but at the same time of warning, external light (sunlight) is also gathered near the imaging module 13 and the backlight module 12 (hereinafter referred to as an image source), so that before corresponding image source protection measures are taken, the image source is already irradiated by the too strong external light, and risks of damage are caused.

To this end, a fourth embodiment of the present invention relates to yet another head up display apparatus 40, and the structure of the head up display apparatus 40 is substantially the same as the head up display apparatus 10 provided in the first embodiment, except that the head up display apparatus 40 provided in the fourth embodiment additionally includes a filter element, as compared with the head up display apparatus 10 of the first embodiment.

Specifically, referring to fig. 14, the head-up display apparatus 40 includes a housing 11, a backlight 12, an imaging module 13, a reflective element 14, a waveguide element 15, a light sensor 16, and a filter element 41. The backlight module 12, the imaging module 13, the reflecting element 14, the waveguide element 15, the illumination sensor 16 and the filter element 41 are all arranged in the housing 11, and the housing 11 has a light outlet 110. The filter element 41 is disposed on a first light path between the light exit 110 and the backlight module 12, the filter element 41 and the backlight module 12 are respectively disposed on a light exit side and a light entrance side of the imaging module 13, and the filter element 41 is configured to transmit imaging light and reduce external light incident on the imaging module of the image source. The design can reduce the external light entering the image source as much as possible, and the reliability of the head-up display device is further improved while timely early warning is guaranteed.

In the present embodiment, the filter element 41 may be a reflective optical device, such as a transflective device or a reflective device, disposed on the propagation path of the imaging light.

a. In one case, the filter element 41 may be a common semi-transmissive semi-reflective device without wavelength selectivity, which is capable of transmitting or absorbing part of light (including visible light rays, infrared rays, and ultraviolet rays) and reflecting part of light (including visible light rays, infrared rays, and ultraviolet rays), and it can be considered that there is little difference in spectral distribution and composition between the transmitted and reflected light rays; therefore, when the external light reversely propagates along the first light path, the external light partially penetrates through the filter element 41 and is partially reflected by the filter element 41, so that the filter element 41 only reflects part of the external light back to the image source along the first light path, thereby reducing the external light incident to the image source and reducing the risk of damage caused by excessive irradiation of the image source. Of course, since the filter elements 41 with different transmittances can reduce the ambient light reaching the image source to different degrees, the intensity of the ambient light reaching the illumination sensor 16 can be weakened to different degrees, for example, the filter element 41 can absorb/transmit 50% of the ambient light and transmit 50% of the ambient light to the image source 10, or the filter element 41 can absorb/transmit 60% of the ambient light and transmit 40% of the ambient light to the image source 10, or the filter element 41 can absorb/transmit 70% of the ambient light and transmit 30% of the ambient light to the image source 10. Under the condition of different transmittances, the normal early warning mechanism can be met only by correspondingly adjusting the size of the first preset threshold.

b. In another case, the filter element 41 may be a transflective device with infrared selectivity (or ultraviolet selectivity) capable of transmitting or absorbing light in the infrared band (or ultraviolet band) and reflecting light in the visible band and the ultraviolet band (or infrared band), so that the visible light emitted from the image source can be almost completely reflected by the filter element 41 without loss; the filter element 41 only reflects visible light and ultraviolet light (or infrared light) in the external light back to the image source along the first optical path, so that the infrared light (or ultraviolet light) in the external light incident to the image source is reduced, and the risk of damage to the image source due to over-irradiation is reduced. It should be noted that, since the filter element 41 cannot ensure 100% transmission or absorption of the infrared light (or ultraviolet light) in practical situations, the light finally reflected back to the image source by the filter element 41 may include ultraviolet light (or infrared light) and a small portion of infrared light (or ultraviolet light), and therefore, the illumination sensor 16 may be an ultraviolet sensor and/or an infrared sensor.

Alternatively, the filter 41 can transmit or absorb light in the infrared and ultraviolet bands and reflect light in the visible band, so that the visible light emitted from the image source can be almost completely reflected by the filter 41 without loss; the filter element 41 only reflects visible light in the external light back to the image source along the first optical path, so that infrared light and ultraviolet light in the external light incident to the image source are reduced, and the risk of damage to the image source due to over-irradiation is reduced. It should be noted that, in practical situations, the filter element 41 cannot ensure 100% transmission or absorption of the infrared light and the ultraviolet light, so that there will be a small portion of infrared light and a small portion of ultraviolet light in the light finally reflected by the filter element 41 back to the image source, and therefore, the illumination sensor 16 can be selected as the ultraviolet sensor and/or the infrared sensor accordingly.

It will be appreciated that the filter element 41 may also absorb infrared and/or ultraviolet light, such that the ambient light reaching the image source 10 may be of lower intensity.

c. In yet another case, the filter element 41 is capable of reflecting light of a first polarization state and transmitting or absorbing light of a second polarization state; specifically, the first polarization state is perpendicular to the second polarization state, and may be linearly polarized light or circularly polarized light or elliptically polarized light; the external light is generally unpolarized light, and may be considered to include a first polarization state and a second polarization state that are perpendicular to each other; meanwhile, the image source emits light in the first polarization state, for example, the image source may be a liquid crystal display emitting polarized light, so that the light in the first polarization state emitted by the light emitted from the image source can be almost completely reflected by the filter element 41 without loss; the filter element 41 only reflects the light propagation path of the second polarization portion of the external light back to the image source, so as to reduce the intensity of the external light incident on the image source by about 50%, thereby reducing the risk of damage to the image source due to over-irradiation.

It is understood that the filter element 41 may also absorb light of the second polarization state, so that the intensity of the external light reaching the image source is lower.

d. In another case, the light emitted by the image source is visible light with a predetermined wavelength band having a first polarization state, and may specifically be imaging light with the first polarization state formed by mixing three RGB lights, for example, the image source is a liquid crystal display using an LED light source emitting RGB mixed white light, and specifically, a central point of a first wavelength band in the RGB wavelength bands is located between 411nm and 480nm, a central point of a second wavelength band is located between 500nm and 565nm, and a central point of a third wavelength band is located between 590nm and 690 nm. In this case, the filter 41 can reflect the light in the RGB band and having the first polarization state, and the transflective device can transmit or absorb the light in the RGB band and outside the first polarization state and the light outside the RGB band in the external light, the first polarization state can be linear polarization, circular polarization or elliptical polarization, for example, the RGB light with a peak width of 50nm passing through the horizontal line polarization state, and the visible light emitted from the image source can be reflected by the filter 41 without loss; at this time, the filter element 41 reflects only the light with the first polarization state in the RGB band back to the image source, thereby greatly reducing the radiant energy of the external light. In practical applications, the light filter 41 cannot ensure 100% transmission or absorption of light in the RGB band and light outside the first polarization state of the external light, and the light sensor 16 may correspondingly select a sensor, an infrared sensor or an ultraviolet sensor of light in the visible light band and light outside the RGB band.

It will be appreciated that the filter element 41 may also absorb ambient light other than the visible light band of the specific wavelength band, so that the ambient light reaching the image source may have a lower intensity. Furthermore, the filter element 41 may also be designed as a "reflective optical device for reflecting light of each wavelength band having a first polarization state and transmitting or absorbing light of each wavelength band having a second polarization state", etc., and it is understood that the above is only a distance description of possible embodiments and not a list of all possible embodiments.

Also, the filter element 41 is not limited to the reflection type optical device, and it may be a transmission type optical device provided on the propagation path of the imaging light, as shown in fig. 15, in which case the filter element 41 may be a transflective device for transmitting a part of the light and reflecting another part of the light (of the visible light, the infrared and the ultraviolet reaching the filter element 51, a part of the visible light, a part of the infrared and a part of the ultraviolet will be transmitted through the filter element 51, and the remaining part of the visible light, the remaining part of the infrared and the remaining part of the ultraviolet will be reflected by the filter element 51); the filter element 41 may also be a transmissive optical device for transmitting visible light rays and for reflecting or absorbing infrared and/or ultraviolet rays; the filter element 41 may in turn be a reflective optical device for transmitting light having a first polarization state and for reflecting or absorbing light having a second polarization state; the filter element 41 may also be a reflective optical device for transmitting visible light rays having the first polarization state. The specific working principle and process are substantially similar to those of the foregoing solutions, except that the filter element 41 is used as a transmissive optical device rather than a reflective device here, and is used to block or absorb a part of external light, so as to reduce the transient irradiation to the image source and avoid the image source from being damaged, which is not described herein.

In addition, as for the structure of the filter element 41, it may include a selective transflective film stacked by an inorganic oxide thin film or a polymer thin film, the transflective film being stacked by at least two film layers having different refractive indexes. The term "different refractive index" used herein means that the refractive index of the film layer is different in at least one of the x, y and z directions; the film layers with different refractive indexes are selected in advance, the film layers are stacked according to a preset sequence, a transflective film with selective reflection and selective transmission characteristics can be formed, and the transflective film can selectively reflect light with one characteristic and transmit light with the other characteristic. Specifically, for the film layer of the inorganic oxide material, the composition of the film layer is selected from one or more of tantalum pentoxide, titanium dioxide, magnesium oxide, zinc oxide, zirconium oxide, silicon dioxide, magnesium fluoride, silicon nitride, silicon oxynitride and aluminum fluoride. For the film layer of the organic high molecular material, the film layer of the organic high molecular material comprises at least two thermoplastic organic polymer film layers; the two thermoplastic polymer film layers are alternately arranged to form the optical film, and the refractive indexes of the two thermoplastic polymer film layers are different. The molecules of the organic polymer material are in a chain structure, and the molecules are arranged in a certain direction after being stretched, so that the refractive indexes in different directions are different, namely, the required film can be formed through a specific stretching process. The thermoplastic polymer can be PET (polyethylene terephthalate) and derivatives thereof with different polymerization degrees, PEN (polyethylene naphthalate) and derivatives thereof with different polymerization degrees, PBT (polybutylene terephthalate) and derivatives thereof with different polymerization degrees, and the like.

A fifth embodiment of the present invention provides a head-up display system 50, as shown in fig. 16, comprising a transflector 51 having a reflective region 510, and the head-up display apparatus 10 as provided in the first embodiment, the head-up display apparatus 10 being arranged to project imaging light rays along an imaging light path to the reflective region 510 to form a virtual image on one side of the transflector 52; and in particular the side of the transflector 52 remote from the heads-up display device 10. The head-up display device 50 includes a housing 11, and a backlight module 12, an imaging module 13, a reflective element 14, a planar reflector 14 ', a waveguide element 15, and an illumination sensor 16 disposed in the housing 11, wherein the reflective element 14 is a curved reflector, and the imaging light path refers to a light propagation path from the backlight module 12 to the imaging module 13, then to the reflective element 14, and then to a reflective area 510 via a light outlet (not shown) of the housing 11, and when the head-up display device 10 further includes one or more planar reflectors 14', the imaging light path refers to a light propagation path from the backlight module 12 to the imaging module 13, then to the reflective element 14, and then to the reflective area 510 via the light outlet (not shown) of the housing 11. After being projected to the reflection area 510 along the imaging optical path, the imaging light is reflected to the areas where the eyes of the driver are located (i.e., the eye boxes), so that the driver can see the HUD image. It should be noted that, the eye box area has a certain size, and both eyes of the driver deviate from the center of the eye box by a certain distance, such as up and down, left and right, and as long as the driver is still in the eye box area, the image of the HUD can be seen. The imaging light emitted from the imaging module 13 in this embodiment can be converged and fall into the center of the eye box by the reflection of the plane mirror 14', the reflection element 14, and the transflective device 51.

Since the backlight module 12 includes the dispersion element 126 as shown in fig. 6, the light emitted from the light source 120 passes through the light guide element 122 and the light condensing element 124, and then passes through the dispersion element 126. Therefore, in the present embodiment, the light can be accurately dispersed by the dispersing element 126, so that the dispersed light beam can cover the eye box region after being reflected by the plane mirror 14', the reflecting element 14 and the transflective device 51, which is just covered by the eye box region in the present embodiment, so as to achieve high light efficiency and not affect normal observation. It will be appreciated that the dispersed beam may be larger than the eye box area, as long as complete coverage of the eye box is ensured; preferably, after the dispersion element 116 is arranged, the dispersed light beam just covers the eye box area, where the system is most efficient.

The head-up display system 50 may be used in the field of automobiles, and the transflective device 51 may be a windshield of an automobile, and because the windshield has a high reflectivity for S polarized light, the light emitted from the image source including the backlight module 12 and the imaging module 13 is generally S polarized light, for example, the image source is an lcd (liquid crystal display) module emitting S polarized light. However, when the driver wears the sunglasses, the sunglasses filter the S-polarized light, and therefore, the HUD image cannot be seen when the sunglasses are worn. Therefore, it is preferable that a phase retardation element (not shown), such as an 1/4 wave plate, be disposed between the light outlet 110 and the windshield (i.e., the transflective device 51) to convert the imaging light in the S-polarization state into circularly polarized light to generate a P-polarized light component, so that the driver can see the HUD image when wearing sunglasses. Of course, the phase delaying element is not limited to be disposed between the windshield and the light exit 110, and may be disposed at other positions on the imaging optical path between the reflecting element 22 and the windshield, such as: a. is arranged between the reflecting element 14 (curved surface reflector) and the light outlet and is mutually spaced with the curved surface reflector and the light outlet; b. the dustproof cover is arranged at the light outlet of the shell and seals the light outlet from the inner side of the light outlet of the shell to play a dustproof role; c. on the reflecting surface of the reflecting element 14 so that a separate carrying structure for the phase delay element is not required, and the like.

It can be understood that if the image source is adjusted to emit imaging light in P polarization state, the driver can see the image without the phase retardation element when wearing sunglasses, but because the reflectivity of the windshield to P-polarized light is low, a P-polarized reflective film can be configured on the reflective area 510 of the windshield (i.e., the transflective device 51).

Furthermore, it is understood that the head-up display system 50 according to the fifth embodiment of the present invention may also include the head-up display device 20 replaced with the head-up display device according to any one of the first, second, third, and fourth embodiments.

When the transflective device 51 is a windshield, since the windshield is generally a curved surface, the position of the virtual image 10' formed by reflecting the image source by the curved surface mirror is located at the focal plane of the transflective device 51, or is smaller than one focal length of the transflective device 61 and close to the focal plane of the transflective device 51 (that is, the image source 10 is located at or close to the focal plane of the transflective device 61). In this case, according to the curved-surface imaging rule, the virtual image (indicated by the dashed rectangle in the figure) formed by the image source after passing through the reflective element 14 and the transflective device 51 can be formed at a longer distance or an infinite distance, such as 30 meters, 50 meters, 70 meters, or even an infinite distance, and is suitable for the AR-HUD, and has a better effect of enhancing the display fit with the outdoor scene.

Preferably, when the transflective device 51 is a windshield, a wedge-shaped film may be additionally arranged in the interlayer of the transflective device 51, and the wedge-shaped film can eliminate double images; in addition, a selective reflection film may be additionally disposed on the inner surface of the transflective device 51 (the surface of the transflective device 51 facing the reflective element 14), and the selective reflection film only reflects the imaging light emitted from the image source, and if the imaging light includes light of three RGB wave bands, the selective reflection film only reflects the RGB light and transmits other light, so that the imaging light is not reflected twice on the inner surface of the outer side of the transflective device 51 (the side of the transflective device 51 facing away from the reflective element 14), and further ghost images are eliminated. In addition, an 1/4 wave plate or a 1/2 wave plate can be additionally arranged on the inner surface of the transflective device 51 to be matched with an image source capable of emitting S polarized light, the S polarized imaging light is reflected by the reflecting film, the transmitted light is converted into circularly polarized light or P polarized light through the wave plate, the reflectivity of the inner surface on the outer side of the transflective device 51 is low, and therefore double images are eliminated. In addition, a P-polarized light reflecting film can be additionally arranged on the inner surface of the transflective device 51 to match with an image source capable of emitting P-polarized light, and after the P-polarized imaging light is reflected by the reflecting film, the transmitted P-polarized light can also be transmitted out of the transflective device 51 because the glass has higher transmittance to the P-polarized light, and the reflectivity of the inner surface on the outer side of the transflective device 51 is very low, so that double images are eliminated.

A sixth embodiment of the present invention provides a transportation apparatus including the head-up display system provided by the above-described embodiment of the present invention. In some examples, a front window (e.g., a front windshield) of the traffic device is multiplexed as a transflective device of the head-up display system, and the head-up display system is disposed near the front window multiplexed as the transflective device (e.g., below the front windshield, above the front windshield, etc.) to generate imaging light for forming a corresponding image according to vehicle-related information such as speed per hour, navigation, etc., and project the imaging light toward the front window of the traffic device, and the imaging light is reflected by the front window toward an area where both eyes of a driver are located (i.e., an eyebox), so that the driver can view the HUD image without lowering his head.

For example, the vehicle device may be various suitable vehicles, and may include, for example, various types of land vehicle devices such as automobiles, or may be a water vehicle device such as a boat, or the like, as long as a front window is provided at its driving position and an image is transmitted to the front window through an in-vehicle display system.

It will be understood by those skilled in the art that the foregoing embodiments are specific examples of the invention, and that various changes in form and detail may be made therein without departing from the spirit and scope of the invention, which should be limited only by the scope of the appended claims.

Claims

1. A head-up display device is characterized by comprising a shell, an image source and a reflecting element, wherein the image source and the reflecting element are arranged in the shell and are sequentially arranged along a first light path; the image source comprises a backlight module and an imaging module which are sequentially arranged along the first light path, the backlight module is used for generating backlight and projecting the backlight to the imaging module along the first light path, the imaging module is used for receiving the backlight and generating imaging light, and the reflecting element is used for receiving the imaging light and reflecting the imaging light to the light outlet;

the head-up display apparatus further includes a waveguide element and an illumination sensor arranged in this order along a second optical path,

the waveguide element is positioned on the first light path and is used for transmitting light rays from the backlight module or the imaging light rays, collecting external light rays on the first light path and sending the external light rays to the illumination sensor;

the illumination sensor is located outside the first optical path and used for collecting illumination intensity of external light from the waveguide element and generating a first trigger signal when the illumination intensity reaches a first preset threshold value.

2. The head-up display device according to claim 1, wherein the waveguide member includes a light incoupling portion, a light conduction portion, and a light outcoupling portion, the light incoupling portion being disposed in the first light path to couple in the external light in the first light path, the light conduction portion being configured to conduct the external light incoupled by the light incoupling portion to the light outcoupling portion, the light outcoupling portion being configured to couple out the external light from the light conduction portion and transmit the external light to the illumination sensor.

3. The head-up display apparatus according to claim 2, wherein the light incoupling part is disposed on the first light path between the backlight module and the imaging module.

4. The head-up display apparatus according to claim 2, wherein the light incoupling part and the backlight module are respectively located at two opposite sides of the imaging module.

5. The heads-up display device of claim 1 further comprising a diffusing element disposed on the second optical path between the waveguide element and the illumination sensor.

6. The heads-up display device of claim 5 wherein the illumination sensor is one or more.

7. The head-up display device of claim 1, wherein the waveguide element is couplable to ultraviolet light or infrared light, and the illumination sensor is an ultraviolet light sensor or an infrared light sensor.

8. The head-up display device of claim 1, wherein the waveguide element is couplable to visible light in a different wavelength band than the imaging light, and the illumination sensor is a visible light sensor.

9. The head-up display device of claim 1, wherein the waveguide element is capable of coupling in ultraviolet light, infrared light, and visible light of a different wavelength band from the imaging light, and the illumination sensor is at least one of a visible light sensor, or an ultraviolet light sensor, and an infrared light sensor.

10. The head-up display device according to claim 1, wherein the waveguide member includes a light incoupling part for incoupling the external light, the light incoupling part including at least one of a surface grating and a bulk grating.

11. The head-up display device according to claim 1, wherein the backlight module comprises a light source for generating light, and a light guide element, a light condensing element and a dispersing element which are sequentially arranged on the light emitting side of the light source, the light guide element is used for collecting the light generated by the light source and transmitting the collected light to the light condensing element, the light condensing element is used for condensing the light from the light guide element and transmitting the condensed light to the dispersing element, and the dispersing element is used for dispersing the light from the light condensing element and transmitting the dispersed light to the imaging module.

12. The head-up display device of claim 11, wherein the light guide element is a housing having a light exit opening, the light source is received in the housing, the light focusing element is disposed at the light exit opening, and an inner wall of the housing is a light reflecting surface for reflecting light generated by the light source and transmitting the light to the light focusing element through the light exit opening.

13. The head-up display device according to claim 1, further comprising an image source protection device connected to the illumination sensor and having a standby state and a protection state, the image source protection device being configured to operate in the standby state when the illumination sensor does not generate the first trigger signal and to operate in the protection state when the illumination sensor generates the first trigger signal,

14. The heads-up display apparatus according to claim 13, further comprising an illumination monitor connected to the image source protection device, the illumination monitor being configured to detect an illumination intensity of the ambient light incident on the image source and generate a second trigger signal when the illumination intensity of the ambient light incident on the image source is detected to be lower than a second predetermined threshold, the image source protection device being configured to return to the standby mode after the illumination monitor generates the second trigger signal.

15. The head-up display apparatus according to claim 13, wherein the image source protection device comprises a driver and a light shielding plate in transmission connection with the driver, the light shielding plate is disposed adjacent to at least one of the light outlet, the reflective element and the image source, and the driver is configured to drive the light shielding plate to move into the propagation path of the imaging light in the protection state to shield at least one of the light outlet, the reflective element and the image source from the external light toward the image source, and drive the light shielding plate to move out of the propagation path of the imaging light in the standby state without shielding the light outlet, the reflective element and the image source.

16. The head-up display apparatus according to claim 15, further comprising an illumination monitor connected to the driver, the illumination monitor being disposed outside the housing or inside the housing and located on a propagation path of the imaging light between the light shielding plate and the light outlet, the illumination monitor being configured to detect an illumination intensity of the external light and generate a second trigger signal when detecting that the illumination intensity of the external light is lower than a second preset threshold, the image source protection device being configured to resume the standby state in response to the second trigger signal.

17. The head-up display device of claim 13, wherein the image source protection device is a turning mechanism coupled to the reflective element, the reflective element is in an initial position in a standby state, the turning mechanism is configured to turn the reflective element relative to the initial position in the protection state to change a propagation path of ambient light incident on the image source, and the turning mechanism is further configured to turn the reflective element back to the initial position in the standby state.

18. The head-up display apparatus according to claim 17, further comprising a light monitor disposed on the reflective element and connected to the tilting mechanism, wherein the light monitor is configured to detect the illumination intensity of the external light in the protection state and generate a second trigger signal when detecting that the illumination intensity of the external light is lower than a second preset threshold, and the image source protection device is configured to resume the standby state in response to the second trigger signal.

19. The head-up display device according to claim 13, further comprising a controller, the controller being connected to the image source protection device, the controller being configured to start timing after the image source protection device operates in the protection state and to control the image source protection device to switch to the standby state when a timing duration reaches a preset threshold.

20. The head-up display device according to claim 13, further comprising a controller connected to the image source protection device, and a positioning device and an angular motion detection device respectively connected to the controller,

21. The head-up display apparatus according to claim 1, further comprising a filter element disposed on the first light path, wherein the filter element and the backlight module are respectively disposed on a light-emitting side and a light-entering side of the imaging module, and the filter element is configured to transmit the imaging light and reduce ambient light incident on the imaging module.

22. The heads-up display device of claim 21,

the light filtering element is a semi-transmission semi-reflection device and is used for transmitting light and reflecting the light; or

23. The heads-up display device of claim 21,

the filter element is a transmission type optical device and is used for transmitting visible light rays and reflecting or absorbing infrared rays and/or ultraviolet rays; or

24. A heads-up display system comprising a transflector having a reflective region and a heads-up display apparatus as claimed in any of claims 1 to 23 for projecting imaging light along an imaging optical path to the reflective region to form a virtual image on one side of the transflector.

25. The heads-up display system of claim 24 further comprising a phase retarding element disposed in the imaging optical path, the imaging light comprising S-polarized light.

26. The heads-up display system of claim 24 wherein the reflective region has a P-polarized reflective film disposed thereon, and the imaging light comprises P-polarized light.

27. The heads-up display system of claim 24 wherein a virtual image of the image source via the reflective element is located at a focal plane of the transflective device.

28. A transportation device comprising the heads-up display system of any of claims 24-27.